bluuebunny/crossref_metadata_2025 huggingface dataset:
Allocating fishing rights in South Africa: a participatory approach
Authors: JOUBERT A. R. , JANSSEN R. , STEWART T. J.
Published: September 2010

Abstract  A new fishing rights allocation system was introduced in South Africa in 2001. The system, its application and the complaints by fishers were assessed. In response to the weaknesses in the 2001 system, a participatory multicriteria decision analysis (MCDA)‐based approach was proposed as a new system for evaluating applicants. To test the approach, workshops were held with fishers and the authority responsible for allocating rights. The MCDA system allowed the concerns (criteria) of different stakeholders to be integrated into a coherent framework and for their priorities to be reflected in scores and weights. Simple MCDA approaches, accessible to fishers and the authority, were used to elicit scores and weights, thus providing a record of the process and a theoretically justifiable basis for the use of a weighted sum of scores. Although the perception was that the authority and fishers’ priorities were very different, they proved to be similar and could be accommodated in an integrated system.
Effects of an extreme flash flood on the native fish assemblages across a Mediterranean catchment
Authors: PIRES A. M. , MAGALHÃES M. F. , MOREIRA DA COSTA L. , ALVES M. J. , COELHO M. M.
Published: September 2010

Abstract  The effects of an extreme flash flood on the native fish assemblages across a Mediterranean catchment in Southwest Portugal were investigated. The fish community structure and habitat were surveyed at 10 sites pre‐ and post‐flood. Overall species richness and rank abundances changed little after the flood, despite there being a consistent decline in the abundance of small cyprinids. Pre‐ and post‐flood habitat correlates of abundance changed for at least some species, and variability in assemblage structure was associated with flood, depth and pH. These results indicate that extreme floods occurring early in the wet season may have little disruptive effects on the overall structure of native fish assemblages in Mediterranean streams, although may at least partially influence population dynamics for some species. Habitat quality and complexity are likely to play a role in mediating species responses to flooding.
The impact of a pesticide on the physiology and behaviour of hatchery‐reared Atlantic salmon, Salmo salar, smolts during the transition from fresh water to the marine environment
Authors: MOORE A. , COTTER D. , QUAYLE V. , ROGAN G. , POOLE R. , LOWER N. , PRIVITERA L.
Published: September 2010

Abstract  Atlantic salmon, Salmo salar L., smolts were exposed to environmental levels of the pesticide atrazine in a hatchery, tagged with acoustic transmitters and released into fresh water at the peak of the smolt run. The subsequent movements of the smolts were monitored within the freshwater and immediate coastal zones using an array of acoustic receivers. In laboratory‐based studies, exposure to a 0.1 μg L−1 concentration of atrazine over a 72‐h period significantly reduced gill Na+K+ATPase activity but not plasma thyroxine (T4) and triiodothyronine (T3) levels compared with the control group, and on transfer to 33‰ saltwater resulted in 100% mortality. However, exposure to atrazine did not have a significant effect on the subsequent movements of the smolts in the freshwater, estuarine and marine environments. The results are discussed in relation to the impact of diffuse pollution on salmon populations.
Behaviour and survival of pike, Esox lucius, with a retained lure in the lower jaw
Authors: ARLINGHAUS R. , KLEFOTH T. , GINGERICH A. J. , DONALDSON M. R. , HANSON K. C. , COOKE S. J.
Published: September 2010

Abstract  The behaviour and survival of pike, Esox lucius L., released with a retained lure in the mouth was studied relative to control fish, which simulated line breakage prior to landing. Behaviour was monitored during the first hour post‐release with the aid of visual floats attached to the fish, and longer‐term for 3 weeks, by means of externally attached radio transmitters. Lure‐treated pike were less mobile during the first hour post‐release, but exhibited greater mobility and travelled further distances from the release area in the first 24 h after release than controls. From the second day after release, the behaviour of lure‐treated pike was similar to control fish. No mortality occurred in a 3‐week monitoring period. These results are indicative of only short‐term behavioural impairments resulting from a retained lure and rapid resubmission of normal behaviour after simulated break‐offs.
Turbidity increases behavioural diversity in northern pike, Esox lucius L., during early summer
Authors: ANDERSEN M. , JACOBSEN L. , GRøNKJÆR P. , SKOV C.
Published: September 2010

Abstract  Optimal behavioural strategies of aquatic organisms may change with environmental conditions such as turbidity. It was hypothesised that pike, Esox lucius L., adapts to low visibility and potential‐reduced foraging opportunities by an increase in activity and pelagic residence in turbid conditions. Diel activity and habitat use of pike (57–85 cm) were studied in a turbid lake and a clear‐water lake by tracking 31 radio‐tagged pike during two diurnal tracking sessions in June 2006. A significant interaction between lake and total length of pike was found, suggesting a higher activity level in large pike in the turbid lake. In addition, pike exhibited a higher among‐individual variance in movement and habitat use in the turbid lake. These results suggest a higher degree of behavioural diversity in pike in the turbid lake as a response to low visibility and a resulting change in foraging conditions.
Borehole‐guided AVO analysis of P‐P and P‐S reflections: Quantifying uncertainty on density estimates
Authors: Djikpesse Hugues A. , Meghirbi Wael , Nizkous Irina , Cao Di
Published: September 2010

Seismic properties of isotropic elastic formations are characterized by the three parameters: acoustic impedance, Poisson's ratio and density. Whilst the first two are usually well estimated by analysing the amplitude variation with angle (AVA) of reflected P‐P waves, density is known to be poorly resolved. However, density estimates would be useful in many situations encountered in oil and gas exploration, in particular, for minimizing risks in looking ahead while drilling. We design a borehole seismic experiment to investigate the reliability of AVA extracted density. Receivers are located downhole near the targeted reflectors and record reflected P‐P and converted P‐S waves. A non‐linear, wide‐angle‐based Bayesian inversion is then used to access the a posteriori probability distributions associated with the estimation of the three isotropic elastic parameters. The analysis of these distributions suggests that the angular variation of reflected P‐S amplitudes provides additional substantial information for estimating density, thus reducing the estimate uncertainty variance by more than one order of magnitude, compared to using only reflected P‐waves.
Path‐integral seismic imaging
Authors: Landa E. , Fomel S. , Moser T.J.
Published: September 2010

A new type of seismic imaging, based on Feynman path integrals for waveform modelling, is capable of producing accurate subsurface images without any need for a reference velocity model. Instead of the usual optimization for traveltime curves with maximal signal semblance, a weighted summation over all representative curves avoids the need for velocity analysis, with its common difficulties of subjective and time‐consuming manual picking. The summation over all curves includes the stationary one that plays a preferential role in classical imaging schemes, but also multiple stationary curves when they exist. Moreover, the weighted summation over all curves also accounts for non‐uniqueness and uncertainty in the stacking/migration velocities. The path‐integral imaging can be applied to stacking to zero‐offset and to time and depth migration. In all these cases, a properly defined weighting function plays a vital role: to emphasize contributions from traveltime curves close to the optimal one and to suppress contributions from unrealistic curves. The path‐integral method is an authentic macromodel‐independent technique in the sense that there is strictly no parameter optimization or estimation involved. Development is still in its initial stage, and several conceptual and implementation issues are yet to be solved. However, application to synthetic and real data examples shows that it has the potential for becoming a fully automatic imaging technique.
Non‐monotone spectral projected gradient method applied to full waveform inversion
Authors: Zeev Noam , Savasta Olga , Cores Debora
Published: September 2010

The seismic inversion problem is a highly non‐linear problem that can be reduced to the minimization of the least‐squares criterion between the observed and the modelled data. It has been solved using different classical optimization strategies that require a monotone descent of the objective function. We propose solving the full‐waveform inversion problem using the non‐monotone spectral projected gradient method: a low‐cost and low‐storage optimization technique that maintains the velocity values in a feasible convex region by frequently projecting them on this convex set. The new methodology uses the gradient direction with a particular spectral step length that allows the objective function to increase at some iterations, guarantees convergence to a stationary point starting from any initial iterate, and greatly speeds up the convergence of gradient methods. We combine the new optimization scheme as a solver of the full‐waveform inversion with a multiscale approach and apply it to a modified version of the Marmousi data set. The results of this application show that the proposed method performs better than the classical gradient method by reducing the number of function evaluations and the residual values.
Non‐hyperbolic moveout inversion of wide‐azimuth P‐wave data for orthorhombic media
Authors: Vasconcelos Ivan , Tsvankin Ilya
Published: September 2010

The azimuthally varying non‐hyperbolic moveout of P‐waves in orthorhombic media can provide valuable information for characterization of fractured reservoirs and seismic processing. Here, we present a technique to invert long‐spread, wide‐azimuth P‐wave data for the orientation of the vertical symmetry planes and five key moveout parameters: the symmetry‐plane NMO velocities, V(1)nmo and V(2)nmo, and the anellipticity parameters, η(1), η(2) and η(3). The inversion algorithm is based on a coherence operator that computes the semblance for the full range of offsets and azimuths using a generalized version of the Alkhalifah–Tsvankin non‐hyperbolic moveout equation.

The moveout equation provides a close approximation to the reflection traveltimes in layered anisotropic media with a uniform orientation of the vertical symmetry planes. Numerical tests on noise‐contaminated data for a single orthorhombic layer show that the best‐constrained parameters are the azimuth ϕ of one of the symmetry planes and the velocities V(1)nmo and V(2)nmo, while the resolution in η(1) and η(2) is somewhat compromised by the trade‐off between the quadratic and quartic moveout terms. The largest uncertainty is observed in the parameter η(3), which influences only long‐spread moveout in off‐symmetry directions. For stratified orthorhombic models with depth‐dependent symmetry‐plane azimuths, the moveout equation has to be modified by allowing the orientation of the effective NMO ellipse to differ from the principal azimuthal direction of the effective quartic moveout term.

The algorithm was successfully tested on wide‐azimuth P‐wave reflections recorded at the Weyburn Field in Canada. Taking azimuthal anisotropy into account increased the semblance values for most long‐offset reflection events in the overburden, which indicates that fracturing is not limited to the reservoir level. The inverted symmetry‐plane directions are close to the azimuths of the off‐trend fracture sets determined from borehole data and shear‐wave splitting analysis. The effective moveout parameters estimated by our algorithm provide input for P‐wave time imaging and geometrical‐spreading correction in layered orthorhombic media.
Observation of azimuthal anisotropy from the seismic reflectivity of a Tertiary turbidite sand
Authors: MacBeth Colin , Shams Asghar
Published: September 2010

P‐wave data from a time‐lapse 3D OBC survey have been analysed to estimate and interpret azimuthal seismic anisotropy. This is achieved by careful processing to preserve the azimuthal signature. The survey images a major reservoir body in a channelized turbidite field in the Gulf of Mexico. Three distinct and significant anisotropy anomalies are discovered on or around this particular ‘4500‐ft sand’, all of which change intensity but not orientation with hydrocarbon production. These anomalies are distributed along the highest concentration of cumulative sand thickness, with their symmetry axes aligned with the main channel axis. We suspect that this time‐lapse anisotropy could be caused by the alignment of the depositional grain fabric. Theoretical calculation predicts that this mechanism, when combined with fluid‐saturation changes, can generate the observed pattern of behaviour. If further supported by other researchers, this result would indicate that appropriately designed seismic surveys could be a useful tool for palaeo‐direction studies in clastic reservoirs and also a useful constraint for directional permeability in the reservoir flow simulation model.
Refraction traveltime and amplitude corrections for very near‐ surface inhomogeneities
Authors: Palmer Derecke
Published: September 2010

The performance of refraction inversion methods that employ the principle of refraction migration, whereby traveltimes are laterally migrated by the offset distance (which is the horizontal separation between the point of refraction and the point of detection on the surface), can be adversely affected by very near‐surface inhomogeneities. Even inhomogeneities at single receivers can limit the lateral resolution of detailed seismic velocities in the refractor.

The generalized reciprocal method ‘statics’ smoothing method (GRM SSM) is a smoothing rather than a deterministic method for correcting very near‐surface inhomogeneities of limited lateral extent. It is based on the observation that there are only relatively minor differences in the time‐depths to the target refractor computed for a range of XY distances, which is the separation between the reverse and forward traveltimes used to compute the time‐depth. However, any traveltime anomalies, which originate in the near‐surface, migrate laterally with increasing XY distance. Therefore, an average of the time‐depths over a range of XY values preserves the architecture of the refractor, but significantly minimizes the traveltime anomalies originating in the near‐surface. The GRM statics smoothing corrections are obtained by subtracting the average time‐depth values from those computed with a zero XY value. In turn, the corrections are subtracted from the traveltimes, and the GRM algorithms are then re‐applied to the corrected data. Although a single application is generally adequate for most sets of field data, model studies have indicated that several applications of the GRM SSM can be required with severe topographic features, such as escarpments.

In addition, very near‐surface inhomogeneities produce anomalous head‐wave amplitudes. An analogous process, using geometric means, can largely correct amplitude anomalies. Furthermore, the coincidence of traveltime and amplitude anomalies indicates that variations in the near‐surface geology, rather than variations in the coupling of the receivers, are a more likely source of the anomalies.

The application of the GRM SSM, together with the averaging of the refractor velocity analysis function over a range of XY values, significantly minimizes the generation of artefacts, and facilitates the computation of detailed seismic velocities in the refractor at each receiver. These detailed seismic velocities, together with the GRM SSM‐corrected amplitude products, can facilitate the computation of the ratio of the density in the bedrock to that in the weathered layer. The accuracy of the computed density ratio improves where lateral variations in the seismic velocities in the weathered layer are known.
A time‐domain induced‐polarization method for estimating permeability in a shaly sand reservoir
Authors: Tong Maosong , Li Li , Wang Weinan , Jiang Yizhong
Published: September 2010

It is known that the time‐domain induced‐polarization decay curve for a shaly sand reservoir depends on the pore structure of the reservoir, and this curve can be used to estimate permeability, which is a determining factor in making production decisions in the petroleum industry. Compared with NMR logging tools, induced polarization has several advantages, such as a deep depth of investigation and a high signal‐to‐noise ratio. The purpose of this paper is to establish an appropriate model using induced polarization to estimate the permeability. The curve can be modelled as a weighted superposition of exponential relaxations. The plot of weight versus the relaxation time constant is defined as the relaxation time spectrum.

Induced‐polarization decay‐curve measurements were performed on 123 samples from the Daqing oilfield using a four‐electrode technique. A singular‐value decomposition method was used to transform the induced‐polarization decay data into a spectrum. Different models to estimate the permeability were discussed. The results of the research indicate that the induced‐polarization measurements greatly improve the statistical significance of permeability correlations. Compared with the traditional forms, AφC and AFC, the forms, ATBφC and ATBFC, have lower error factors, where T, Φ and F are the geometric mean time constant of the induced‐polarization relaxation time spectrum, the porosity and the resistivity formation factor, respectively, and A, B and C are constants. The mean time constant is the decisive parameter in the permeability estimation and it is not completely independent of the resistivity formation factor. The additional use of the porosity and the resistivity formation factor leads to an appreciable improvement. It is concluded that this new model will make it possible to estimate the permeability of a shaly sand reservoir downhole.
3D Fourier finite‐difference migration by alternating‐direction‐implicit plus interpolation
Authors: Zhang Jin‐Hai , Wang Wei‐Min , Fu Li‐Yun , Yao Zhen‐Xing
Published: September 2010

Conventional two‐way splitting Fourier finite‐difference migration for 3D complex media yields azimuthal anisotropy where an additional phase correction is needed with much increase of computational cost. We incorporate the alternating‐direction‐implicit plus interpolation scheme into the conventional Fourier finite‐difference method to reduce azimuthal anisotropy. This scheme retains the high‐order remnants ignored by the two‐way splitting in the form of a wavefield interpolation in the wavenumber domain. The wavefield interpolation for each step of downward extrapolation is implemented between the wavefields before and after the conventional Fourier finite‐difference extrapolation. As the Fourier finite‐difference migration is implemented in the space and wavenumber dual space, the Fourier transforms between space and wavenumber domain that were needed for the alternating‐direction‐implicit plus interpolation in frequency domain (FD) migration are saved in Fourier finite‐difference migration. Since the azimuth anisotropy in Fourier finite‐difference is much less than that in FD, the application of the alternating‐direction‐implicit plus interpolation scheme in Fourier finite‐difference migration is superior to that in FD migration in handling complex media with large velocity contrasts and steep dips. Impulse responses show that the presented method reduces the azimuthal anisotropy at almost no extra cost.
A global perspective of ground level, ‘ambient’ carbon dioxide for assessing the response of plants to atmospheric CO2
Authors: Ziska L. H. , Ghannoum O. , Baker J. T. , Conroy J. , Bunce J. A. , Kobayashi K. , Okada M.
Published: September 2010

For most studies involving the response of plants to future concentrations of atmospheric carbon dioxide (CO2), a current concentration of 360–370 μatm is assumed, based on recent data obtained from the Mauna Loa observatory. In the present study, average seasonal diurnal values of ambient CO2 obtained at ground level from three global locations (Australia, Japan and the USA) indicated that the average CO2 (at canopy height) can vary from over 500 μatm at night to 350 μatm during the day with average 24‐h values ranging from 390 to 465 μatm. At all sites sampled, ambient CO2 rose to a maximum value during the pre‐dawn period (03.00–06.00 hours); at sunrise, CO2 remained elevated for several hours before declining to a steady‐state concentration between 350 and 400 μatm by mid‐morning (08.00–10.00 hours). Responses of plant growth to simulations of the observed variation of in situ CO2 were compared to growth at a constant CO2 concentration in controlled environment chambers. Three diurnal patterns were used (constant 370 μatm CO2, constant 370 during the day (07.00–19.00 hours), high CO2 (500 μatm) at night; or, high CO2 (500 μatm) at night and during the early morning (07.00–09.00 hours) decreasing to 370 μatm by 10.00 hours). Three plant species − soybean (Glycine max, L (Merr.), velvetleaf (Abutilon theophrasti L.) and tomato (Lycopersicon esculentum L.) − were grown in each of these environments. For soybean, high night‐time CO2 resulted in a significant increase in net assimilation rate (NAR), plant growth, leaf area and biomass relative to a constant ambient value of CO2 by 29 days after sowing. Significant increases in NAR for all three species, and significant increases in leaf area, growth and total biomass for two of the three C3 species tested (velvetleaf and soybean) were also observed after 29 days post sowing for the high night/early morning diurnal pattern of CO2. Data from these experiments suggest that the ambient CO2 concentration experienced by some plants is higher than the Mauna Loa average, and that growth of some agricultural species at in situ CO2 levels can differ significantly from the constant CO2 value used as a control in many CO2 experiments. This suggests that a reassessment of control conditions used to quantify the response of plants to future, elevated CO2 may be required.
Distribution of aboveground live biomass in the Amazon basin
Authors: SAATCHI S. S. , HOUGHTON R. A. , DOS SANTOS ALVALÁ R. C. , SOARES J. V. , YU Y.
Published: September 2010

The amount and spatial distribution of forest biomass in the Amazon basin is a major source of uncertainty in estimating the flux of carbon released from land‐cover and land‐use change. Direct measurements of aboveground live biomass (AGLB) are limited to small areas of forest inventory plots and site‐specific allometric equations that cannot be readily generalized for the entire basin. Furthermore, there is no spaceborne remote sensing instrument that can measure tropical forest biomass directly. To determine the spatial distribution of forest biomass of the Amazon basin, we report a method based on remote sensing metrics representing various forest structural parameters and environmental variables, and more than 500 plot measurements of forest biomass distributed over the basin. A decision tree approach was used to develop the spatial distribution of AGLB for seven distinct biomass classes of lowland old‐growth forests with more than 80% accuracy. AGLB for other vegetation types, such as the woody and herbaceous savanna and secondary forests, was directly estimated with a regression based on satellite data. Results show that AGLB is highest in Central Amazonia and in regions to the east and north, including the Guyanas. Biomass is generally above 300 Mg ha−1 here except in areas of intense logging or open floodplains. In Western Amazonia, from the lowlands of Peru, Ecuador, and Colombia to the Andean mountains, biomass ranges from 150 to 300 Mg ha−1. Most transitional and seasonal forests at the southern and northwestern edges of the basin have biomass ranging from 100 to 200 Mg ha−1. The AGLB distribution has a significant correlation with the length of the dry season. We estimate that the total carbon in forest biomass of the Amazon basin, including the dead and belowground biomass, is 86 Pg C with ±20% uncertainty.
Laboratory incubations reveal potential responses of soil nitrogen cycling to changes in soil C and N availability in Mojave Desert soils exposed to elevated atmospheric CO2
Authors: SCHAEFFER SEAN M. , BILLINGS SHARON A. , DAVE EVANS R.
Published: September 2010

Elevated atmospheric carbon dioxide (CO2) has the potential to alter soil carbon (C) and nitrogen (N) cycling in arid ecosystems through changes in net primary productivity. However, an associated feedback exists because any sustained increases in plant productivity will depend upon the continued availability of soil N. We took soils from under the canopies of major shrubs, grasses, and plant interspaces in a Mojave Desert ecosystem exposed to elevated atmospheric CO2 and incubated them in the laboratory with amendments of labile C and N to determine if elevated CO2 altered the mechanistic controls of soil C and N on microbial N cycling. Net ammonification increased under shrubs exposed to elevated CO2, while net nitrification decreased. Elevated CO2 treatments exhibited greater fluxes of N2O–N under Lycium spp., but not other microsites. The proportion of microbial/extractable organic N increased under shrubs exposed to elevated CO2. Heterotrophic N2‐fixation and C mineralization increased with C addition, while denitrification enzyme activity and N2O–N fluxes increased when C and N were added in combination. Laboratory results demonstrated the potential for elevated CO2 to affect soil N cycling under shrubs and supports the hypothesis that energy limited microbes may increase net inorganic N cycling rates as the amount of soil‐available C increases under elevated CO2. The effect of CO2 enrichment on N‐cycling processes is mediated by its effect on the plants, particularly shrubs. The potential for elevated atmospheric CO2 to lead to accumulation of NH4+ under shrubs and the subsequent volatilization of NH3 may result in greater losses of N from this system, leading to changes in the form and amount of plant‐available inorganic N. This introduces the potential for a negative feedback mechanism that could act to constrain the degree to which plants can increase productivity in the face of elevated atmospheric CO2.
Spatial and temporal variability of net ecosystem production in a tropical forest: testing the hypothesis of a significant carbon sink
Authors: SIERRA CARLOS A. , HARMON MARK E. , MORENO FLAVIO H. , ORREGO SERGIO A. , Del VALLE JORGE I.
Published: September 2010

Tropical forest ecosystems play an important role in the global carbon balance. Depending on age and land use, they can act as carbon sources, sinks, or be in approximate balance, but it is uncertain if global environmental changes are forcing these ecosystems outside their natural range of variation. We asked the question of whether or not the net carbon flux of a tropical primary forest, which should be in balance over the long term, is within the expected range of natural variation. A simple Bayesian hypothesis testing method was used to address this question for primary forests in the Porce region of Colombia. Net ecosystem production (NEP) was measured in this forest in a set of 33 permanent plots from 2000 to 2002 in 2, 1‐year intervals. Our estimate of NEP ranged between −4.03 and 2.22 Mg C ha−1 yr−1for the two intervals. This range was compared witha prioridefined range of natural variation estimated from the ecosystem model STANDCARB, which estimated spatial and temporal variation due to gap dynamics. The prior range of variation was estimated between −1.5 and 1.5 Mg C ha−1 yr−1. The observed data on NEP did not provide sufficient evidence to reject the null hypothesis that these forests are in C balance. We concluded that the ecosystem is likely behaving within its range of natural variation, but measurement uncertainties were a major limitation to finding evidence to reject the null hypothesis. A literature review of C flux studies in the tropics revealed that about half of the observations could be explained by gap dynamics alone, while significant C sinks have only been observed during La Niña years, with contrasting results in other tropical forests. In conclusion, observational data of carbon fluxes do not appear to provide direct evidence for a significant carbon sink in some sites in the tropics.
Developing theory‐based risk‐reduction interventions for HIV‐positive young people with haemophilia
Authors: Schultz J. R. , Butler R. B. , Mckernan L. , Boelsen R. ,   FOR THE HAEMOPHILIA BEHAVIORAL INTERVENTION EVALUATION PROJECT
Published: September 2010

Eleven haemophilia treatment centres in the United States collaborated in the Hemophilia Behavioural Intervention Evaluation Projects (HBIEP) to develop theory‐based interventions to reduce the risk of HIV transmission from seropositive adolescents and young adults with haemophilia. While the Transtheoretical Model of Behaviour Change and the Theory of Reasoned Action provided the theoretical underpinnings, the exact form in which these theories would be applied depended on developmental research. This paper presents the various phases of the process to develop the theory based interventions: literature review, qualitative interviews, quantitative surveys, a provider survey, a materials review, and the actual planning. All or portions of this process could be applied to the development of interventions for many behaviour‐change projects. A description of the HBIEP interventions is also provided.
An emerging role for interferon in haemophiliacs with chronic hepatitis C?
Authors: Aguilar C. , Lucia J. F. , SimÓn M. A.
Published: September 2010

The combination of interferon (IFN) and ribavirin is the current gold standard for treatment of chronic hepatitis C virus (HCV) infection with sustained remission rates of 35–40% being achieved in haemophilic patients. A similar beneficial effect of this combined therapy has been suggested even for patients with compensated liver cirrhosis and some authors have reported a possible role for IFN and ribavirin in the prevention or delay in the development of hepatocellular carcinoma (HCC), a well known complication of HCV infection in haemophiliacs. The absence, due to design difficulties, of definite randomized controlled clinical trials remains a handicap for the routine use of specific therapy of HCV infected patients with the aim of preventing HCC. A discussion of these important issues has been performed in this paper.
What factors should influence the dosage and interval of prophylactic treatment in patients with severe haemophilia A and B?
Authors: Petrini P.
Published: September 2010

In order to prevent arthropathy, prophylaxis has to start at a young age before recurrent joint bleedings have taken place. The use of central venous lines has facilitated an early beginning to treatment, but due to side‐effects, most European paediatricians prefer peripheral injections whenever possible. By starting primary prophylaxis at the age of 1–2 years with one injection weekly, the need for surgical implants may be reduced. In this study, only four of 34 boys born 1988–98 with severe haemophilia A or B needed a Port‐a‐Cath®for primary prophylaxis. Trough levels were measured in these patients and 79% showed a trough level < 1%, while 21% reached a level > 1%. Despite this, joint bleedings during 1998 were rare in both groups [0–4] and 59% of the boys with trough levels < 1% did not report any haemartroses during that year. Mean annual joint bleedings were the same in both groups [0.70, 0.71]. The lowest effective level of factors VIII and IX must be determined individually for each patient on primary or secondary prophylaxis.
A comparison of FVII:C and FVIIa assays for the monitoring of recombinant factor VIIa treatment
Authors: Cid A. R. , Lorenzo J. I. , Haya S. , Montoro J. M. , CasaÑa P. , Aznar J. A.
Published: September 2010

The use of recombinant factor VIIa (rFVIIa) is on the increase, not only to treat haemophilic patients with inhibitors, but also patients with other clotting disorders. However, the most appropriate method of monitoring this treatment remains a question that has yet to be resolved. We studied 24 plasma samples from patients receiving rFVIIa treatment (three had haemophilia A with inhibitors, and three a congenital FVII deficiency) and compared the results obtained from the FVII:C and FVIIa assays. Although a good correlation between the two methods was obtained (r=0.91), the values of the FVII:C method were 1.63 higher than those of the FVIIa method, with a relatively wide margin in the interval of the FVII:C/FVIIa ratios obtained [95% confidence interval (CI) 1.38–1.88, range 0.68–3.68]. This interval became wider when we compared values of over 6 IU mL–1, which led us to conclude that the two methods cannot be considered equivalent. As the FVIIa method specifically measures FVIIa, and FVII:C assay is known to have a wide interlaboratory variability, we believe that the FVIIa assay would be more suitable for the monitoring of rFVIIa treatment.
Methods to treat chronic haemophilic synovitis
Authors: Rodriguez‐Merchan E. C.
Published: September 2010

The aim of both synoviorthesis and surgical synovectomy is to remove the inflamed and hypervascular synovium as soon as possible in order to prevent the onset of haemophilic arthropathy. Ideally, however, these methods should be performed before the articular cartilage has eroded. Radioactive synoviorthesis is a relatively simple, virtually painless and inexpensive technique for the treatment of chronic haemophilic synovitis, even in patients with inhibitors. Thus, radioactive synoviorthesis is the best choice for patients with persistent synovitis. Personal experience and the general recommendation among orthopaedic surgeons and haematologists is that when three early consecutive synoviorthesis (repeated every 3 months) fail to halt synovitis, a surgical synovectomy (open or by arthroscopy) should be immediately considered.
Mild haemophilia A discovered in a previously multi‐operated 73‐year‐old man: characterization of a new mutation
Authors: Bauduer F. , Ducout L. , Bendriss P. , Falaises B. , Lavergne J. M.
Published: September 2010

A mild haemophilia A (factor VIII [FVIII] 10%) was discovered in a 73‐year‐old man during the preoperative haemostasis tests before a total knee arthroplasty for treatment of degenerative senile arthropathy. No history of previous abnormal bleeding was noted in spite of several previous challenging surgical procedures. Acquired haemophilia was ruled out and no other cases of haemophilia were found in the family. The surgery was successfully performed under recombinant FVIII aimed at achieving an FVIII level above 60%. This therapy induced the transient appearance of low‐titre FVIII antibodies. A still unpublished mutation within the exon 3 (Gly73Ala) was found with molecular studies. This case report underlines the importance of haemostasis tests before high‐risk bleeding surgical procedures even in elderly patients without a past history of haemorrhagic tendency.
A new strategy for prenatal diagnosis in a sporadic haemophilia B family
Authors: Acquila M. , Bottini F. , Valetto A. , Caprino D. , Mori P. G. , Bicocchi M. P.
Published: September 2010

Although the quality of life for haemophiliacs has clearly improved in the last few years, haemophilia still remains a serious disorder justifying prenatal diagnosis (PD) and, if necessary, termination. Because chorionic villus sampling (CVS) is performed in the first trimester of pregnancy, an increasing number of carriers are interested in this test. It has been shown that waiting for the results is particularly distressing for pregnant women, therefore decreasing the diagnostic procedure time can be psychologically helpful. Here we report on PD in a sporadic haemophilia B family based on the direct identification of the pathogenic mutation in a CVS taken at the 12th gestational week. In order to hasten the results, we recovered DNA from a single villus fragment boiled in water and used it directly for PCR reaction. Conformation‐sensitive gel electrophoresis (CSGE) was used to detect the mutation in the haemophilia carrier and in the foetus. This approach allowed us to obtain a diagnosis within 24 h of CVS, thus avoiding the long‐term psychological effects on the pregnant woman.
A case of chronic myelomonocytic leukaemia and factor XI deficiency with a circulating anticoagulant
Authors: Billon S. , Blouch M‐T. , Escoffre‐Barbe M. , Le Niger C. , Le Roux A‐M. , Abgrall J‐F.
Published: September 2010

Inhibitors against factor XI (FXI) have been frequently described in patients who acquired inhibitors (due to auto‐inmune disorders, malignancies or infections), but less often in those with a congenital deficiency of this factor, who had received plasma infusions. The present report concerns one such inhibitor found in the plasma of a patient with chronic myelomonocytic leukaemia and infected by B19 parvovirus, who was neither a heterozygote nor a homozygote for FXI deficiency, and who had no bleeding tendency despite a very low FXI level. Taking this case into account, we discuss and present the clinical and biological features of acquired FXI deficiency caused by an inhibitor.
Influence of von Willebrand factor on the reactivity of human factor VIII inhibitors with factor VIII
Authors: Gensana M. , Altisent C. , Aznar J. A. , Casaña P. , Hernández F. , Jorquera J. I. , Magallón M. , Massot M. , Puig L.
Published: September 2010

In order to determine the difference in reactivity of factor (F) VIII inhibitors against the FVIII/von Willebrand factor (vWF) complex and against vWF‐deficient FVIII, we investigated a panel of 10 antibodies to FVIII from multitransfused individuals with severe haemophilia A and other pathologies. Immunoblotting of purified FVIII and purified thrombin‐cleaved FVIII revealed that in all cases inhibitor epitopes could be localized in the heavy chain (A2 subunit) while in four cases they were also present in the light chain. One of the FVIII inhibitors remained unclassified. The effect on FVIII:C of purified IgG from inhibitor plasmas was tested against a high purity FVIII/vWF concentrate and a monoclonally purified FVIII concentrate with only trace contents of vWF, by two different functional assays. Our results suggest that for those inhibitors showing A2 plus light chain (LC) reactivity, the IgG concentration required to inhibit 50% of FVIII activityin vitrois higher for the FVIII/vWF complex than for the vWF‐deficient FVIII. We conclude that there might be a protective role of vWF (at leastin vitro) against FVIII inhibitors with A2 and LC subunit specificity.
Postpartum inhibitor to factor VIII: treatment with high‐dose immunoglobulin and dexamethasone
Authors: Mazzucconi M. G. , Bizzoni L. , Giorgi A. , Morano S. G. , Peraino M. , Russo M. , Alimena G.
Published: September 2010

Spontaneous occurrence of an acquired inhibitor to factor VIII (FVIII) is a rare event. About 50% of cases are idiopathic. Among younger people, inhibitors are often found in the postpartum period. Treatment must be administered either to overcome haemorrhagic symptoms or to eradicate the inhibitor. Several approaches have been proposed for inhibitor eradication, based on immunosuppressive drugs such as corticosteroids, cyclophosphamide and azathioprine, with varying results. High‐dose immunoglobulin (HDIg) has been recently proposed as first‐line therapy. We report on four cases with acquired inhibitor to FVIII occurring 4–8 months after delivery. At diagnosis, inhibitor titre was < 5 Bethesda units mL–1 (BU mL–1) in three cases and > 5 BU mL–1 in one. Factor VIII coagulant activity (FVIII:C) was < 1 U dL–1> in three cases and 12 U dL–1 in one. We treated the patients with HDIg (400 mg kg–1 day–1 for 5 consecutive days) and dexamethasone (24 mg day–1 for 5–7 consecutive days), administered at the same time. In three women, the inhibitor was suppressed in 2–50 weeks. After an off‐therapy period ranging from 20 to 104 weeks, the FVIII:C was persistently normal and the inhibitor undetectable. The fourth woman remained unresponsive. In two cases, recombinant activated factor VII administration stopped the bleeding. Thus, intermediate‐ to high‐dose dexamethasone and HDIg given at the same time could be a successful and safe therapeutic approach for a rapid and complete remission from the development of FVIII inhibitors.
von Willebrand factor in factor VIII concentrates protects against neutralization by factor VIII antibodies of haemophilia A patients
Authors: Kallas A. , Talpsep T.
Published: September 2010

We investigated the neutralization activity of factor VIII (FVIII) antibodies of 12 haemophilia A patients, acquired during treatment with plasma‐derived FVIII concentrates. All plasma samples, drawn in a clinically stable situation before any immunotolerance treatment, contained anti‐A2 domain and anti‐light‐chain FVIII antibodies. In nine patients’ plasmas, containing relatively high amounts of FVIII light‐chain antibodies (53–96%), a higher neutralization activity was found against recombinant FVIII concentrate (Recombinate) than against plasma‐derived von Willebrand factor (vWF)‐containing concentrate (Haemoctin SDH). No difference in neutralization of the two concentrates was found in two patients’ plasmas with almost equal content of FVIII light‐ and heavy‐chain antibodies, or one plasma with predominantly heavy‐chain antibodies. These results suggest that haemophilia A patients with relatively high amounts of FVIII light‐chain antibodies in plasma might benefit by infusion of FVIII concentrates containing vWF because vWF appears to have some protective effect on FVIII. This hypothesis should be tested by a clinical study.
Fanhdi®, efficacy and safety in von Willebrand’s disease: prospective international study results
Authors: BELLO I. F. , YUSTE V. J. , MOLINA M. Q. , NAVARRO F.H.
Published: September 2010

Summary.  Recently, three multicentre prospective international studies have been carried out to evaluate the clinical efficacy and safety of Fanhdi® [high‐purity, double‐inactivated plasma‐derived factor VIII/von Willebrand factor (VWF) concentrate] in patients with von Willebrand’s disease (VWD). Pharmacokinetic parameters, clinical efficacy and safety of Fanhdi® in acute bleedings episodes or invasive procedures were determined in this population.

Results. Pharmacokinetic parameters observed were similar to previous reported for other highly purified plasma‐derived FVIII/VWF concentrate. The mean in vivo recovery (IU dL−1 per IU kg−1) was 1.9 ± 0.6 for VWF:RCof; 2.1 ± 0.6 for VWF:Ag and 2.6 ± 0.6 for FVIII:C. The mean half‐life (h) was 14.4 ± 10.5 for VWF:RCof; 27.5 ± 11.0 for VWF:Ag and 33.4 ± 16.4 for FVIII:C. Therapeutic benefit of Fanhdi® in VWD patients treated during bleeding episodes was clearly demonstrated. The achievement of haemostasis was excellent or good in 100% of the cases (major or minor bleeding episodes). Also, the clinical efficacy of Fanhdi® in preventing excessive bleeding during surgery showed a very good profile. Efficacy was rated as excellent in six cases (three major/three minor surgical procedures) and good in three cases (two major/one minor surgical procedures). In addition, the product was well tolerated and no adverse events potentially related to the study drug were reported.

Conclusions. Fanhdi® is an effective and safe plasma‐derived FVIII/VWF concentrate that can be used as an alternative to the current replacement therapy in patients with VWD to provide an adequate haemostasis during surgical procedures and treatment of bleeding episodes.
Highly purified VWF/FVIII concentrates in the treatment and prophylaxis of von Willebrand disease: the PRO.WILL Study
Authors: FEDERICI A. B.
Published: September 2010

Abstract  Two therapeutic approaches are available to manage patients with von Willebrand disease (VWD): (i) the release of endogenous von Willebrand factor (VWF) from endothelial compartments induced by desmopressin (DDAVP); (ii) the transfusion of exogenous VWF contained in VWF/FVIII plasma‐derived concentrates. Only a few high‐purity VWF/FVIII concentrates have been extensively evaluated in pharmacokinetic (PK) trials as well as in retrospective or prospective efficacy studies in VWD. The Alphanate Study Group published results of PK and clinical efficacy studies in 2002. Efficacy results showed that 75% of bleeding episodes were controlled with one or two infusions, and 71% of patients who received prophylactic treatment for surgeries or invasive procedures had good clinical responses. In another retrospective study, 22 VWD patients in Italy received Fanhdi, a VWF concentrate similar to Alphanate. Excellent–good clinical responses were seen in 92% of bleeding episodes and in 93% of surgical procedures. More recently, the efficacy and safety of Fanhdi have been evaluated retrospectively in a larger cohort of Italian patients (n = 103) with 97% (bleedings) and 99% (surgeries) of excellent/good clinical responses. The largest experience on secondary prophylaxis in VWD has been collected in Sweden in 35 patients with severe forms of VWD. Secondary prophylaxis was also implemented in a cohort of Italian patients with VWD. Prophylaxis was started because of GI bleeds in seven patients with types 3 (n = 1), 2A (n = 4), 2M (n = 1) and type 1 (n = 1) and for joint bleeds in four patients with type 3 VWD (n = 4). Prophylaxis prevented bleeding completely in eight patients and largely reduced hospitalization for blood transfusions in the remaining three. The cost‐effectiveness of these prophylaxis regimens versus on demand therapy will be now investigated in one large prospective study (PRO.WILL) organized in Italy.
History of haemophilia
Authors: ALEDORT L. M.
Published: September 2010

Summary.  Haemophilia, an ancient disease, now has sophisticated methods for diagnosis and treatment. The genetically missing factors can now be supplied by fractionation of human‐derived (HD) plasma or with recombinant technology (r). Making therapeutic choices is complicated by past transfusion‐transmitted diseases. HD and r products now have similar safety profiles. Several diseases have only HD products for treatment. These products remain important in our treatment armamentarium.
Combined FV and FVIII deficiency
Authors: SPREAFICO M. , PEYVANDI F.
Published: September 2010

Summary.  Inherited deficiencies of plasma proteins involved in blood coagulation generally lead to lifelong bleeding disorders. The severity of these disorders is generally inversely proportional to the degree of factor deficiency. Among all the autosomal recessive rare bleeding disorders, which include afibrinogenaemia, factor (F) II, FV, FV + VIII, FVII, FX, FXI, FXIII, the combined deficiency of coagulation FV and FVIII (F5F8D or FV + FVIII) is exceptional because it is due to mutations in genes encoding proteins involved in the FV and FVIII intracellular transport (LMAN1 and MCFD2) rather than DNA defects in the genes that encode the corresponding coagulation factors. F5F8D is estimated to be extremely rare (1:1.000.000) in the general population, but an increased frequency is observed in regions where consanguineous marriages is practiced. F5F8D is characterized by concomitantly low levels (usually between 5% and 20%) of both FV and FVIII, and is associated with a mild to moderate bleeding tendency. Treatment of bleeding episodes requires a source of both FV and FVIII; replacement of FV is achieved through the use of fresh frozen plasma, and that of FVIII by desmopressin or specific FVIII concentrates, plasma‐derived or recombinant FVIII products. We focus here on the clinical, molecular, treatment‐related and diagnostic features of F5F8D.