bluuebunny/crossref_metadata_2025_split huggingface dataset:
Partial fishing mortality per fishing trip: a useful indicator of effective fishing effort in mixed demersal fisheries
Authors: Rijnsdorp Adriaan D. , Daan Niels , Dekker Willem 
Published: January 2006

Abstract
Effort management has been proposed as an alternative for quota management in mixed demersal fisheries. It requires a metric to estimate the fishing mortality imposed by a given quantity of nominal fishing effort. Here, we estimate the partial fishing mortality rate imposed by one unit of fishing effort (Fpue) during individual fishing trips and explore the usefulness of this indicator for managing North Sea beam trawlers >300 hp targeting sole (Solea solea) and plaice (Pleuronectes platessa). Fpue is positively related to vessel engine power, and increased annually by 2.8% (sole) and 1.6% (plaice). The positive trend was due to an increase in skipper skills and investment in auxiliary equipment, the replacement of old vessels by new ones and, to a lesser extent, to upgrade engines. The average Fpue imposed per day at sea by a 2000 hp beam trawler was estimated to be 1.0 × 10−5 (sole) and 0.6 × 10−5 (plaice), and it showed substantial seasonal and spatial variations. The Fpue of sole and plaice were negatively related in summer and showed no relationship in winter. The existence of predictive seasonal and spatial patterns in Fpue opens up the possibility of fine-tuning management by directed effort restrictions and uncoupling management of plaice and sole.
Benthic responses to organic enrichment and climatic events in the western North Sea
Authors: Rees H.L. , Pendle M.A. , Limpenny D.S. , Mason C.E. , Boyd S.E. , Birchenough S. , Vivian C.M.G. 
Published: January 2006

Macrofaunal assemblages inhabiting stable offshore muddy sand substrata responded predictably to the effects of mild organic enrichment arising from sewage-sludge disposal off the north-east coast of England (western North Sea). At the disposal site, densities were elevated up to two-fold, but classical ‘indicator’ species were only marginally enhanced and there was no evidence of a significant waste-induced change in assemblage structure. The response following cessation of disposal was equally predictable, with a decline in densities to ‘reference’ levels some three years later. However, physical manifestations of disposal, including tomato pips and non-biodegradable artefacts, were still evident after this time.Changes in diversity at selected monitoring stations tended to track each other over time and the employment of treatment/reference ratios and limit values for acceptable change provided a useful model for the simplified expression of trends. Predictions concerning the limited scale and intensity of the effects of sewage-sludge disposal appear to have been met, indicating that the management option of sea disposal was, at the time, an environmentally acceptable one.Temporal trends in the benthic fauna were also correlated with winter values of the North Atlantic Oscillation Index for the preceding year. The densities and variety of species tended to be lower in response to warmer winters characterized by westerly airflows which were commonly encountered in the 1990s. Finally, the increasing importance of extended time-series data for the investigation of man-made impacts on the marine environment is highlighted, along with the accompanying requirement for continuity and quality assurance of sampling programmes.
Temporal variation of a syllid (Syllidae: Polychaeta) taxocoenosis associated with Stypocaulon scoparium (Stypocaulaceae: Phaeophyceae) in the western Mediterranean
Authors: López Eduardo , Gallego Ramón 
Published: January 2006

Between May of 2000 and July of 2001 a study aiming to determine the seasonal variation of syllid local population abundances was carried out. Samples were taken every second month and consisted of two replicates, each one being a quadrat 20 cm wide. After fixing, the samples were washed and the draining water was passed through a 1 mm sieve; then the syllids were identified and counted. For each replicate a number of ecological indexes were calculated, namely population density, number of species and Shannon's and Simpson's diversity indexes, computing mean values for each sample. In order to identify the most representative species of the taxocoenosis the Ci (constancy index, frequency of the species ranging from 0 to 1) and Di (dominance index, relative abundance ranging from 0 to 100 considering all the collected individuals) were computed for each one.Analysis of the eight samples yielded 6548 individuals and 48 species belonging to the four subfamilies of Syllidae, of which Exogoninae and Syllinae were the most abundant and diverse. During the study period, the syllid taxocoenosis suffered dramatic changes. The abundance, that in May of 2000 was 33,375±775 individuals/m2, diminished to 2162.5±37.5 in September. After this date, the population density slowly increased. The number of present species evolved in a very similar way. Twelve species occurred in all the samples, although just six were abundant enough to yield Ci×Di products exceeding 5, thus being considered as good descriptors of the taxocoenosis. The variation of population density for most of these species more or less paralleled that of the total population of syllids. With regards to relative abundance, the taxocoenosis was always clearly dominated by Exogoninae species, especially by Salvatoria vieitezi, whose dominance scores always fluctuated around 45%. Syllis prolifera was the only important non-Exogoninae species in terms of dominance, although this parameter showed strong variation in this species.
Scavenging behaviour by Ergalatax contractus (Gastropoda: Muricidae) and interactions with Nassarius nodifer (Gastropoda: Nassariidae) in the Cape d'Aguilar Marine Reserve, Hong Kong
Authors: Morton Brian 
Published: January 2006

Aspects of the feeding behaviour of Ergalatax contractus (Muricidae) were studied. Field experiments demonstrated that large numbers of individuals of this species, comprising ∼90% of a suite of gastropod scavengers, were attracted to baited traps in the subtidal sands of Lobster Bay, Cape d'Aguilar Marine Reserve, Hong Kong. Laboratory experiments identified the effective chemo-detection distances of E. contractus as 60 cm in still and >80 cm in flowing water, respectively. The average times to arrival at bait in still and flowing water were 92.3 and 69.0 min, respectively, but were significantly less for individuals experiencing a longer period of starvation. The mean time taken for E. contractus to consume a meal was 70.6 min.Comparisons were made between Ergalatax contractus and Nassarius nodifer, representative of a suite of sympatric scavenging nassariids in Lobster Bay. The nassariid arrived significantly faster at bait in both still (30.2 min) and flowing water (20.8 min) than E. contractus and fed faster (25.7 min), as is typical of representatives of the Nassariidae. Although the two species partition carrion resources temporally, manipulation experiments provided evidence for inter-specific competition between them. That is, although E. contractus possesses the morphological and behavioural characteristics of a predator, its opportunistic scavenging abilities have led to its success and numerical superiority on the shallow subtidal sands of Lobster Bay. The dominance of E. contractus in Lobster Bay, and elsewhere in Hong Kong, is unusual. Here, the normally predatory E. contractus, far outnumbers all other scavengers, possibly because of an enhanced, largely allochthonous, supply of food which it is able to exploit by virtue of its previously identified opportunistic habit of scavenging the leftovers of other predators. The presence of inter-specific competition between E. contractus and a sympatric suite of nassariids enhances, not impedes, carrion exploitation.
Vaccines for cervical cancer
Authors: LOWNDES C. M. 
Published: January 2006

SUMMARYThis review focuses on current and future prevention of invasive cervical cancer (ICC), the second most common cancer among women worldwide. Implementation of population-based cytological screening programmes, using the ‘Pap’ smear to detect pre-cancerous lesions in the cervix, has resulted in substantial declines in mortality and morbidity from ICC in North America and some European countries. However, cases of, and deaths from, ICC continue to occur. Primary prevention of infection with high-risk human papillomavirus (HPV) types, the central causal factor of ICC, could further reduce incidence of and mortality from ICC. This is particularly the case in developing countries, which bear 80% of the burden of ICC, and where effective Pap screening programmes are extremely difficult to implement. Very promising results from several trials of synthetic HPV type-specific monovalent (HPV 16) and bivalent (HPV 16 and 18) vaccines have recently been published, showing high efficacy against type-specific persistent HPV infection and development of type-specific pre-cancerous lesions. Large-scale phase III trials of a number of such vaccine candidates are currently underway, and there is real hope that an effective vaccine capable of protecting against infection with HPV types 16 and 18 (which together account for ∼70% of cervical cancer cases worldwide), and thereby of preventing development of a very significant proportion of cases of ICC, could be available within the next 2 years.
Interpretation of the Magnetic Properties of the Rare Earth Chromites and the Rare Earth Manganites
Authors: Aleonard R. , Pauthenet R. , Rebouillat J. P. , Veyret C. 
Published: January 2006

The magnetostatic properties of the rare earth chromites, RCrO3, and those of the rare earth manganites, RMnO3, have been studied between 1.6° and 1500°K, in fields up to 28 000 Oe. These compounds are antiferromagnetic; they present two Néel points.
For the rare earth chromites, the first Néel point varies between 112°K for LuCrO3 and 282°K for LaCrO3; it corresponds to the ordering of the spins of the Cr3+ ions; below this transition temperature, a ferromagnetism is superimposed upon the antiferromagnetism. The second Néel point is situated in the neighborhood of the temperature of liquid helium; it corresponds to the ordering of the moments of the rare earth ions.
These properties are interpreted in terms of a molecular-field model. The lattice of the Cr3+ ions and that of the R3+ ions are decomposed into two identical sublattices. The Cr-Cr exchange interaction is negative; it is dominant; it defines principally the first Néel point. The R-R interaction is negative and weaker; it defines the second Néel point. The R-Cr interaction can be positive or negative, and its magnitude is small. The configuration of the moments of the chromium ions can be weakly ferromagnetic; this would induce a ferromagnetic polarization of the rare earth ion, and can give rise to a compensation temperature.
With the perovskite rare earth manganites, the first Néel point is between 45°K for EuMnO3 and approximatively 131°K for LaMnO3; a ferromagnetism is superimposed upon the antiferromagnetism. These substances behave like the rare earth chromites.
With the hexagonal rare earth manganites, the first Néel point is characterized only by a change in the slope of the susceptibility curve; there is no superimposed ferromagnetism. Near 10°K, it appears a ferromagnetic term which can be induced by the ordering of the spins of the rare earth ions. The rare earth-manganese interaction is determined in the molecular-field approximation.
The interpretation of the magnetic properties of the rare earth chromites has been published in the “Compt. Rend, 262, 799, 866 (1966); a full report on the interpretation of the magnetic properties of the rare earth maganites will be published in “J. Phys.”.
Spin Waves in 3d Metals
Authors: Shirane G. , Minkiewicz V. J. , Nathans R. 
Published: January 2006

A review is given of recent measurements of spin-wave dispersion relations of the 3d metals by the Brookhaven neutron diffraction group using the diffraction technique and triple-axis spectrometry. The parameters D and β in the relation ħω = Dq2(1 − βq2) have been determined at 295°K for Fe, Co, Ni, and some of their alloys. These values are compared with those obtained by thin-film resonance and small-angle scattering.
The most extensive measurements were carried out on Fe using a triple-axis spectrometer. The dispersion relation was measured along the three principal symmetry directions for wavevectors up to q/qmax = 0.4. The stiffness constant D as well as the linewidth of selected spin waves were studied for the temperature range between 77°K and the Curie temperature, 1042°K. Well-defined magnons were observed up to a reduced temperature T/TC = 0.995, but not above TC.
Electric Multipole Interactions between Rare Earth Ions
Authors: Wolf W. P. , Birgeneau R. J. 
Published: January 2006

Electrostatic coupling between rare earth ions is important for nonradiative optical-energy transfer processes and for effective spin-spin interactions in ionic salts. In calculating such effects is it generally assumed that the electric quadrupole-quadrupole term is much larger than the corresponding interaction between higher degree multipole moments because successive terms of a given parity are each a factor r2/R2∼100 smaller than the preceding one. (r is the radius of 4f-electron orbit and R is the ionic separation). In this paper we point out that the relative importance of the higher-degree terms may be enhanced by electrostatic shielding and induced-moment effects similar to those affecting single ion crystal field terms, and we derive the Hamiltonian operators for the l-l′ multipole interactions up to sixth degree. Comparison with the observed single ion crystal fields also suggests that electric multipole interactions might be relatively important throughout the rare earth series and not only for the larger light ions, as is often assumed.
For pairs of Kramers ions at low temperatures (S′ = 12) the various multipole interactions will contribute in second order to different terms of an effective spin Hamiltonian of the form Si′ · K · Sj′, and the resulting interaction tensor K will generally be quite anisotropic, subject only to symmetry. There is also a corresponding anisotropic contribution to the magnetic g tensor, whose principal values and axes may thus be different from those of the single ions. Detailed multipole calculations are prohibitively complicated in the general case, and unless it can be shown that the higher degree terms are in fact negligible the observable interaction parameters in any particular case must therefore be treated as strictly empirical quantities, restricted only by symmetry.
A more detailed discussion of these effects is being published elsewhere.
Some Properties of Ferromagnetoelectric Nickel Iodine Boracite
Authors: Kaczér J. , Shalnikova T. , Hauptman Z. 
Published: January 2006

Synthetic and very pure single crystals of nickel iodine boracite (Ni3B7O13I, NIB), up to 10 mm in their largest dimension grown by a chemical transport process were investigated, using a self-compensating recording balance under quasistatic conditions. Below 64°K ferromagnetic behavior in agreement with the results of Ascher, Rieder, Schmid, and Stössel was observed. Rotation diagrams showed a slight hexagonal component in the (111) plane of the crystal. In the (100) plane, however, large tetragonal torsion moments were recorded having frequent discontinuities and very large rotational hysteresis in fields of about 5 kOe. In a temporally and spatially constant magnetic field, a discontinuous but on the average linear decrease of the torsion moment was observed, taking about 30 min for it to vanish completely.
The above behavior can be only partly explained on the basis of ferromagnetic-domain wall motion. The influence of ferroelectric-domain processes coupled through ferromagnetoelectric interaction seems to be of considerable importance for the relaxation of magnetization and is therefore assessed and discussed.
Domain-Wall Dynamics in Fe from Pulsed NMR Experiments
Authors: Stearns M. B. , Overhauser A. W. 
Published: January 2006

The dependence of free induction decay and echo amplitude of NMR signals in Fe on rf field strength B1 pulse length τ, and frequency ω has been determined by an extensive series of measurements The observed variation of free-induction decay amplitude with B1τ and ω cannot be explained by a rigid oscillation of domain walls, as usually supposed. Such a model fails, even though proper account is taken of enhancement-factor distribution caused by B1 orientation, and by spatial arrangement of spins perpendicular to the central plane of each wall.
We propose a different model where each domain wall is considered immobile along its periphery. Wall oscillation then resembles that of a drumhead. This modification alters significantly the enhancement-factor distribution. Furthermore, the average enhancement factor of each wall is proportional to its area. Accordingly, a distribution in wall areas is also postulated. The predictions of this model are in excellent agreement with free-induction decay spectra.
Enhancement factors of impure samples are smaller than those of pure ones by as much as a factor of three, indicating that the average wall area in such specimens is smaller by a similar factor. This supports the view that impurities augment domain nucleation.
A Magnetically Pulsed Neutron Beam for Time-of-Flight Measurements of Inelastic Scattering
Authors: Mook H. A. , Wilkinson M. K. 
Published: January 2006

In many types of experiments, time-of-flight neutron spectrometers have the advantage of higher counting rates than crystal spectrometers, especially in view of the fact that multiple counters may be used. A method of magnetically pulsing a neutron beam has been developed that avoids the necessity of using high-speed rotating equipment.
The magnetic intensity in a Bragg reflection depends on the orientation of the atomic magnetic moments relative to the scattering vector, and it becomes zero when the moments are directed along the scattering vector. The direction of magnetization in ferrite crystals can be switched rapidly with an external magnetic field so that these crystals can serve both as a neutron monochromator and pulser. Furthermore, the neutron pulse-width and repetition rate can easily be varied by changing the current pulse that produces the external field.
The nuclear contribution for the (111) or (331) reflections can be made very small for 7Li-Ti ferrite of the correct composition. Large magnetic scattering intensities can be obtained in each case. The pulsed magnetic field is produced by switching the energy stored in a pulse-forming network into a magnet-drive coil by means of a silicon controlled rectifier. The pulse risetime is about 1 μsec and the pulse length in the present instrument is 12 μsec.
X-Ray and Susceptibility Study of the First-Order Magnetic Transformation in Mn3Pt
Authors: Krén E. , Szabó P. , Pál L. , Tarnóczi T. , Kádár G. , Hargitai C. 
Published: January 2006

The first-order transformation from triangular to collinear antiferromagnetic structure (AF-AF transformation) has been investigated in the Mn3Pt1−xRhx and Mn3+yPt1−y systems by x-ray diffraction and magnetic methods.
At the AF-AF transformation temperature Tt a discontinuous change in the lattice parameter is observed with a magnitude depending on concentration but with always the same lattice parameter value of the collinear phase. This implies the existence of a critical lattice parameter value for the AF-AF transformation. Below the Néel temperature TN an anomaly in the thermal expansion occurs indicating exchange interactions dependent on the interatomic separation. This anomaly differs in sign for the collinear-paramagnetic and triangular-paramagnetic transitions. The susceptibility shows an abrupt change at Tt and a maximum at TN in the triangular phase. No maximum occurs for the collinear phase. The observed transition temperatures are in agreement with the earlier neutron diffraction data.
Magnetic and Chemical Order in Pd2MnAl in Relation to Order in the Heusler Alloys Pd2MnIn, Pd2MnSn, and Pd2MnSb
Authors: Webster P. J. , Tebble R. S. 
Published: January 2006

The chemical and magnetic structures of the alloy Pd2MnAl, determined from magnetic and neutron diffraction measurements, are described, and compared with results recently obtained for the alloys Pd2MnIn, Pd2MnSn, and Pd2MnSb.
Pd 2 MnSn and Pd2MnSb have the Heusler (L21) structure, and are ferromagnetic with Curie temperatures of 189°K and 247°K, and magnetic moments, confined to the Mn atoms, of 4.23μB and 4.40μB, respectively. Pd2MnIn may be obtained in ordered (L21) and partially disordered (B2) forms by slow-cooling or quenching, respectively. The ordered alloy is antiferromagnetic with a Néel temperature of 142°K and a magnetic moment of 4.3μB per Mn atom. The magnetic moments are aligned in ferromagnetic (111) planes, with neighbouring planes oriented antiparallel as in NiO. In the partially disordered regions the Pd atoms remain ordered, but disorder occurs between the Mn and In atoms resulting in a B2, CsCl type, structure. The Mn atoms are still antiferromagnetically aligned, but on a magnetic unit cell of reduced size consistent with the change in chemical order.
Pd 2 MnAl has the B2 chemical structure, and a magnetic structure identical to that of the B2 regions of Pd2MnIn. The alloy has a Néel temperature of 240°K, and a magnetic moment of 4.4μB/Mn atom.
Temperature Dependence of the Spin-Wave Energy in the Itinerant Electron Model of Ferromagnetism
Authors: Mathon J. , Wohlfarth E. P. 
Published: January 2006

The long-wavelength noninteracting spin-wave energy for metals at low temperatures is expressed as ħωq = Dq2 = (D0+D1T2)q2. The dependence of the coefficient D1 on the density-of-states function, the number of electrons per atom n and the effective short-range interaction energy I is discussed. The variation of D with T2 comes from the change with temperature of the relative occupation ζ and the chemical potentials of the ± spin subbands as well as from the direct asymptotic expansion of the Fermi distribution functions occurring in the expression for D. Although the calculation is based essentially on the random phase approximation this is here used in an improved version due to Izuyama and Kubo where these distribution functions replace the thermal averages 〈akσ*akσ〉 which would occur in a strict r.p.a. formulation. The general relation for D1 which is obtained reduces to a very simple form giving D = D0ζ/ζ0 in the limit zgr;0→0, where ζ0 is the value of ζ at 0°K.
The general relation for D1 is evaluated numerically for a single tightly bound energy band corresponding to a simple cubic lattice structure. Although the values of D1 obtained are in general negative as normally expected, positive values may also occur for some values of the parameters n and I. The experimental value of D1 for iron2 is in good agreement with the calculated values for reasonable values of the parameters. It is suggested that other experimental data should also be analyzed in terms of D1.
A full account of this work is being published in Proc. Roy. Soc. (London) (1968).