bluuebunny/crossref_metadata_2025 huggingface dataset:
A systematic review of training in acute obstetric emergencies
Authors: Black Rebecca S. , Brocklehurst Peter
Published: December 2003

Objective
To describe models used for the training of labour ward personnel in acute obstetric emergencies and to describe how these models have been evaluated and compared.

Design
A systematic review of the following databases: Medline, the Cumulative Index of Nursing and Allied Health Literature, Embase, PsycLit, Allied and Alternative Medicine, Education Resources Information Center and the Cochrane Library using a structured search strategy.

Setting
Labour ward.

Population or Sample
Labour ward personnel.

Inclusion criteria
All papers that described or evaluated any form of drill or training in acute obstetric emergencies involving any personnel in a labour ward environment were included. Descriptions of training in developing countries were excluded.

Methods
Papers were classified as editorials or commentaries, papers describing a training programme or papers evaluating a training method. A data collection form was used to extract relevant information by two investigators independently.

Main outcome measure
Description of training models.

Results
Of 44 relevant papers, 22 were classed as editorials or commentaries. Six descriptions of training programmes were found and four papers involved an evaluation of such programmes. All evaluations involved the use of questionnaires to course participants. No studies comparing one form of training with another were found.

Conclusions
With regard to training in acute obstetric emergencies, few training programmes have been described, and even fewer have been evaluated. Training methods need to be developed, described and evaluated; further well‐conducted research for this important intervention is urgently required.
Placental edge to internal os distance in the late third trimester and mode of delivery in placenta praevia
Authors: Bhide Amarnath , Prefumo Federico , Moore Jessica , Hollis Brian , Thilaganathan Basky
Published: December 2003

Objectives
To correlate transvaginal ultrasound findings with mode of delivery in cases of placenta praevia.

Design
Cohort study.

Setting
A London Teaching Hospital.

Methods
Retrospective review of all cases of placenta praevia diagnosed by transvaginal ultrasound between February 1997 and March 2002.

Main outcome measures
Likelihood of vaginal delivery and major obstetric haemorrhage.

Results
A total of 121 pregnancies were studied with a mean scan‐to‐delivery interval of 10.5 days. In the 64 women who laboured, the likelihood of vaginal delivery rose significantly as the placental edge to internal os distance increased. Caesarean section rate was 90% when the placental edge–internal os distance was 0.1 to 2.0 cm, falling to 37% when this measurement was over 2.0 cm (P < 0.00045).

Conclusion
Trial of vaginal delivery is appropriate in cases with a placental to internal os distance>2 cm. The term ‘praevia’ should be restricted to cases where the placental edge is ≤2 cm from the internal os, as the likelihood of operative delivery and significant postpartum haemorrhage is high. Cases where the placenta is more than 2 cm from the internal os have a greater than 60% chance of vaginal delivery and should be defined as ‘low lying’ in order to reduce the clinician's bias towards operative delivery.
FE 200 440: a selective oxytocin antagonist on the term‐pregnant human uterus
Authors: Nilsson Lotta , Reinheimer Torsten , Steinwall Margareta , Åkerlund Mats
Published: December 2003

Objective
To compare a newly developed oxytocin antagonist, FE 200 440, with atosiban and ANTAG III, as to potency and selectivity of inhibitory effects on oxytocin‐ and vasopressin‐induced myometrial responses. FE 200 440 has high affinity for the human cloned oxytocin receptor, approximately 300‐fold that for the vasopressin V1a receptor, whereas atosiban binds well to both receptors.

Design
In vitro study of human myometrial contractility.

Setting
The Research Laboratory of the Department of Obstetrics and Gynecology, Lund University Hospital, Sweden.

Participants
Forty‐seven term‐pregnant women not in labour who were delivered by caesarean section.

Interventions
Concentration–response curves with oxytocin and arginine vasopressin on isolated myometrial strips were recorded in control experiments, in the presence of atosiban in concentrations of 25, 250 and 750 nmol/L, and after pretreatment with ANTAG III and FE 200 440, both in concentrations of 2.5, 25 and 250 nmol/L.

Main outcome measure
pA2 values (i.e. an index of inhibitory action).

Results
With oxytocin as the agonist, the median pA2 values for atosiban, ANTAG III and FE 200 440 were 10.6, 9.5 and 8.3, respectively. With vasopressin as the agonist, the pA2 values for atosiban and ANTAG III were 8.8 and 8.7, whereas no inhibitory effect of FE 200 440 was seen in five out of six experiments.

Conclusion
The new analogue FE 200 440 is a selective oxytocin antagonist and, in contrast to atosiban and ANTAG III, has practically no effect on vasopressin‐induced contractions of isolated term‐pregnant human myometrium.
Growth of juvenile tilapia, Oreochromis niloticus L. from Lakes Zwai, Langeno and Chamo (Ethiopian rift valley) based on otolith microincrement analysis
Authors: Admassu D. , Ahlgren I.
Published: December 2003

Abstract – Age and growth of juvenile tilapia, Oreochromis niloticus, from Lakes Zwai, Langeno and Chamo (Ethiopia) were studied from microincrements in otoliths. Growth in length was best described by the Gompertz model. Average growth rate of the fish was most rapid in Lake Chamo (0.39 mm · day−1, 1.14% · day−1), intermediate in Lake Zwai (0.20 mm · day−1, 0.72% · day−1) and slowest in Lake Langeno (0.16 mm · day−1, 0.62% · day−1). Similarly, back‐calculation from otolith increment widths gave growth rates of 0.28 to 0.43 mm · day−1, 0.15 to 0.32 mm · day−1 and 0.11 to 0.28 mm · day−1 for Chamo, Zwai and Langeno fish, respectively. In addition, Fulton's condition factor was largest for Chamo tilapia and smallest for Langeno tilapia; the difference between fish from Langeno and Zwai was small. Rapid growth of juvenile O. niloticus in Lake Chamo was attributed to warm temperature and better food quality.Note
Evidence of concealment behavior by adult rainbow trout and brook trout in winter
Authors: Meyer K. A. , Gregory J. S.
Published: December 2003

Abstract – There has been little investigation of the winter ecology of adult trout during winter, especially in regard to concealment behavior. We compared day vs night underwater counts of adult rainbow trout and brook trout from four streams. At water temperatures between 1°C and 9°C, daytime counts accounted for 44% and 16% of nighttime snorkeling counts for rainbow trout and brook trout adults, respectively. As winter progressed, nighttime counts declined more so for brook trout than rainbow trout, but the decline was not significant for either species. Nocturnalism of both species was higher in streams with colder water temperatures. We observed few fish within concealment structure; however, by electrofishing concealment habitat during the day, we captured 10 times more adult trout than we counted immediately beforehand by snorkeling. Adult trout were concealed in cobble‐boulder substrate and woody debris during the day.Note
The effects of an underwater fish observation technique on stream macroinvertebrates at two spatial scales
Authors: Petty J. T. , Grossman G. D.
Published: December 2003

Abstract – We examined the effects of snorkeling, a commonly used fish observation technique, on the distribution and abundance of benthic macroinvertebrates at both the reach (i.e., 10 m) and patch scale (i.e.,< 1 m) within a southern Appalachian stream (North Carolina, USA). At the reach scale, we quantified increases in macroinvertebrate drift rates associated with snorkeling and used these values to calculate the percentage of the macrobenthos that drifted out of snorkeled reaches. We also used a simple decay model of macroinvertebrate drift to quantify patch scale effects of snorkeling. The model incorporated size specific macroinvertebrate settling rates to estimate the total number of benthic macroinvertebrates that entered the drift in response to snorkeling disturbance. We found that snorkeling consistently produced significant increases in the number of drifting macroinvertebrates. Nevertheless, these increases comprised a very small percentage (<1%) of the total number of organisms in the benthos, suggesting that snorkeling probably did not strongly affect macroinvertebrate assemblages at either the reach or patch scale. However, our analyses also indicated that snorkeling had a disproportionate effect on the drift of small ephemeropterans (4–5% entered the drift in response to snorkeling) relative to other macroinvertebrate taxa. Consequently, the microdistribution of early instar mayflies may have been altered within snorkeled reaches. We conclude that snorkeling related disturbance to the benthos should have a minimal effect on the behavior and distribution of most stream fishes at either the reach or patch scale. However, because snorkeling had a substantial effect on the drift of small mayflies, snorkeling may influence the behavior of fishes that depend on early instar mayflies as a primary food resource.Note
Movement patterns of imperiled blue shiners (Pisces: Cyprinidae) among habitat patches
Authors: Johnston C. E.
Published: December 2003

Abstract – The blue shiner (Cyprinella caerulea) is a federally threatened cyprinid that inhabits discrete habitat patches, but whether the fish in these patches represent distinct subpopulations or a continuous population is not known. Movement patterns of adult blue shiners among habitat patches in the Conasauga River (Tennessee and Georgia, USA) were investigated to determine if movement among patches was unrestricted, or if each patch represented a relatively discrete subpopulation. Movement was restricted to a small proportion of individuals at any given time, and most fish that moved did so between adjacent habitat patches. The average distance moved by blue shiners over the two study periods (1997 and 1998) was just 130.7 m. Riffle and glide mesohabitats were not barriers to the dispersal of blue shiners, and fish moved both upstream and downstream in approximately equal numbers. It is suggested that the fish that are mobile at a given time are responsible for recolonization of habitat patches via cumulative, stepwise movements between adjacent patches, and that intervening patches must be present to maintain connectivity of the entire population. Blue shiners exist as relatively discrete subpopulations in the Conasauga River. This finding emphasizes the importance of protecting habitat integrity throughout the entire course of the river to prevent isolation of subpopulations. This species may be used as a model for the conservation of other patch‐restricted aquatic species.Note
Resource partitioning between lake‐dwelling Atlantic salmon (Salmo salar L.) parr, brown trout (Salmo trutta L.) and Arctic charr (Salvelinus alpinus (L.))
Authors: Jørgensen L. , Halvorsen M. , Amundsen P.‐A.
Published: December 2003

Abstract – Resource partitioning between Atlantic salmon parr, brown trout and Arctic charr was studied throughout the ice‐free season in a north Norwegian lake. Juvenile salmon and trout (≤160 mm) utilized the littoral zone and juvenile charr the profundal, while adult trout and charr (>160 mm) were found in both. Juvenile salmon and trout had a similar diet, although trichopteran larvae were more important for the trout and chironomid pupae and three‐spined sticklebacks for the salmon parr. Small salmon and trout parr (≤120 mm) had a higher diet overlap than larger parr (121–160 mm). The feeding habits of adult trout were similar to that of juvenile trout, but the former took larger prey items. At the population level, both salmon and trout were generalistic feeders with a broad diet, but at the individual level, both species had specialized on a single or a few prey categories. Juvenile charr were segregated from salmon and trout in both habitat and food utilization; they had a narrow diet consisting of chironomids and zooplankton, possibly reflecting their confinement to the profundal habitat which have a low diversity of potential prey. Larger charr also took zoobenthos and sticklebacks in the littoral zone.Note
Size‐related differences in diel activity of two species of juvenile eel (Anguilla) in a laboratory stream
Authors: Glova G. J. , Jellyman D. J.
Published: December 2003

Abstract – The diel activity of three size groups (small=<100 mm; medium=100–199 mm; large=200–299 mm total length) of juvenile shortfinned (“shortfin”) eels (Anguilla australis) and longfinned (“longfin”) eels (A. dieffenbachii) was tested in a laboratory flow tank over a 48‐h period during summer. All size groups of both species were nocturnally active, with the eels hiding in the substratum during the day and coming out on top of the cobbles from dusk to dawn, to feed. During the foraging period, the numbers and activity of all sizes of longfins visible were greater than those seen of shortfins, with the differences being more pronounced for small and medium eels. The activity of all eels consisted mostly of foraging by crawling, searching and probing for prey among the cobbles. Rate of activity increased with size of eel for both species. Small eels of either species did more swimming than eels of the larger sizes, whereas large eels were observed more frequently with only their head out of the substrate than were the smaller individuals. Feeding of small eels within the interstitial spaces of the streambed may explain their significantly lower activity on top of the substrate at night. The significantly lower rate of activity recorded for shortfins than longfins of all sizes may be due partly to their ability to feed within the interstices of the stream bed, and (or) longer time to recover from handling and habituate to the test environment.Note
Diel distribution of age‐0 largemouth bass, Micropterus salmoides, in B. E. Jordan Lake, North Carolina (USA) and its relation to cover
Authors: Irwin E. R. , Noble R. L.
Published: December 2003

Abstract – We used prepositioned area electrofishers (PAEs, 10×1.5 m) to assess diel differences in distribution of age‐0 largemouth bass, Micropterus salmoides, in August 1992–1993 in a paired sampling design. PAEs were placed parallel to shore in an embayment of an unvegetated reservoir (B. E. Jordan Lake, North Carolina, USA). The catch per unit effort (CPUE=fish/PAE) was significantly higher at night than during the day in both years, indicating that age‐0 largemouth bass exhibit nocturnal inshore movements. Age‐0 largemouth bass captured inshore during day were smaller than those captured at night, indicating that movement patterns may change ontogenetically. Inshore‐offshore movements of age‐0 largemouth bass were significantly reduced in the presence of cover, suggesting that diel movements were influenced by specific habitat components. Diel movements likely were related to foraging, resting and predator avoidance behavior and could affect population dynamics and introduce bias in assessment programs.Note
The effects of the menstrual cycle, pregnancy and early lactation on haematology and plasma biochemistry in the baboon (Papio hamadryas)
Authors: Harewood Winthrop J. , Gillin Adrian , Hennessy Annemarie , Armitstead Jeff , Horvath John S. , Tiller David J.
Published: December 2003

The changes in the haematology and clinical biochemistry associated with the different stages of the menstrual cycle, gestation and lactation in the baboon (Papio hamadryas) were evaluated in a prospective longitudinal study. Serial EDTA and heparin blood samples were collected from 12 baboons. Haemoglobin concentration, haematorcrit, red blood cell and white blood cell counts were decreased in the luteal compared to the follicular phase (P<0.001); the reverse effect was observed for platelet count, total protein and albumin concentrations. The changes in plasma concentrations of sodium, potassium, urea, creatinine and cholesterol and plasma osmolality were characterized by reductions (P<0.01) in early pregnancy which were maintained throughout gestation. Plasma concentrations of total protein, albumin and alkaline phosphatase, as well as haemoglobin, haematocrit and red cell count were reduced (P<0.001) from mid‐gestation. Platelet count and plasma calcium concentration fell continuously throughout gestation (P<0.001). Plasma triglycerides were lower and plasma iron was higher (P<0.01) in gestation compared to the phases of the menstrual cycle and lactation. By 1 week post partum, all parameters except haemaglobin had returned to pre‐conception levels.
A prevalence survey for zoonotic enteric bacteria in a research monkey colony with specific emphasis on the occurrence of enteric Yersinia
Authors: Vore Stephen J. , Peele Pamela D. , Barrow Peggy A. , Bradfield John F. , Pryor Jr. William H.
Published: December 2003

Transmissible pathogenic and opportunistic zoonotic enteric bacteria comprise a recognized occupational health threat to exposed humans from non‐human primates (NHPs). In an effort to evaluate the occurrence of selected enteric organisms with zoonotic and biohazard potential in a research colony setting, we performed a prevalence study examining 61 juvenile and young adult rhesus macaques participating in a transplant immunology project. Primary emphasis was directed specifically to detection of pathogenic enteric Yersinia, less well‐documented and reported NHP pathogens possessing recognized significant human disease potential. NHPs were surveyed by rectal culture during routine health monitoring on three separate occasions, and samples incubated using appropriate media and specific selective culture methods. Enteric organisms potentially transmissible to humans were subcultured and identified to genus and species. Significant human pathogens of the Salmonella/Shigella, Campylobacter, and enteric Yersinia groups were not isolated throughout the survey, suggesting prevalence of these organisms may generally be quite low.
Comparative analysis of natural killer cell activity, lymphoproliferation and lymphocyte surface antigen expression in nonhuman primates housed at the CIRMF Primate Center, Gabon
Authors: Poaty‐Mavoungou Virginie , Onanga Richard , Yaba Philippe , Delicat André , Dubreuil Guy , Mavoungou Elie
Published: December 2003

Six different species of nonhuman primates housed at the CIRMF Primate Center, cynomolgus monkeys (Macaca fascicularis), rhesus monkeys (Macaca mulatta), mandrills (Mandrillus sphinx), vervets (Cercopithecus aethiops pygerythrus), chimpanzees (Pan troglodyte) and baboons (Papio hamadryas), were evaluated for their natural killer cell activity and for the ability of their peripheral blood mononuclear cells to proliferate in response to known mitogens (concanavalin A, phytohemagglutinin and staphylococcal enterotoxin A) and to react with a panel of mouse monoclonal antibodies directed against human leukocyte surface antigens. Basic information on normal immune functions in these primates is important because of their use as experimental animal models for the study of human diseases such as acquired immunodeficiency syndrome (AIDS), hepatitis, loiasis and malaria.
Correlation of kidney weight and volume and selected skeletal parameters to sex in the adult rhesus monkey (Macaca mulatta)
Authors: Hill Lori R. , Hess Kenneth R. , Stephens L. Clifton , Price Roger E. , Gray Kenneth N.
Published: December 2003

This report outlines a comparison of renal weight and volume and selected skeletal parameters to sex in 22 adult male and 156 adult female rhesus macaques. Means and standard deviations for kidney weight and volume, body weight, and radiographic measurements for both males and females are reported. Ninety‐five percent confidence intervals and P‐values for the mean differences between the sexes for these parameters were also compiled. Male monkeys were larger, but had kidneys of similar size to those of the females. Joint distributions of the radiographic measurements of the first lumbar vertebra and the skull showed that males were larger in both measurements. The distributions of these parameters were clearly separate in males and females, while joint distributions of kidney weight and volume for males and females overlapped almost completely. We found that, regardless of age, sex, weight, or skeletal size, all normal adult rhesus monkeys generally have similar‐sized kidneys.
FERMIOLOGY IN CORRELATED ELECTRON SYSTEMS
Authors: AOKI HIDEO
Published: December 2003

An overview is given for the way in which electron correlation effects such as magnetism or superconductivity are sensitively dominated by the band structure and the shape of the Fermi surface. This "fermiology in correlated electron systems" arises because the competition between various orders may take place on a subtle energy scale, and this concept can also be exploited in novel (or tailor-made) structures. Specifically we discuss (i) why and how the "flat-band" ferromagnetism can appear from the electron-electron repulsion, (ii) how superconductivity from the repulsion (with the fluctuation-exchange-mediated interaction) can be "optimised" with respect to the band structure. This includes an exotic possibility of spin-triplet pairing, or a recently proposed pairing on disconnected Fermi surfaces.
KONDO ALLOYS AND THE MOTT METAL-INSULATOR TRANSITION: AN OLD PROBLEM REVISITED
Authors: NOZIÈRES P.
Published: December 2003

Please refer to the Proceeding of the 11th International Conference on Recent progress in Many Body Theories, ed. R. F. Bishop (World Scientific, 2002).
ANDREEV REFLECTION AND SUBGAP TRANSPORT DUE TO ELECTRON-MAGNON INTERACTIONS IN FERROMAGNET-SUPERCONDUCTOR JUNCTIONS
Authors: TKACHOV G. , MCCANN E. , FAL'KO V. I.
Published: December 2003

We show that electron-magnon interactions at a ferromagnetic metal-superconductor interface lead to a new process of magnon-assisted Andreev reflection, which consists of the simultaneous injection of a Cooper pair from the superconductor and the emission of a magnon inside the ferromagnet. At low temperature this process represents an additional channel for subgap transport across an FS interface, which lifts restrictions on the current I resulting from the necessity to match spin-polarised current in the ferromagnet with spin-less current in the superconductor. We calculate I using the tunnelling Hamiltonian method and the nonequilibrium (Keldysh) Green functions technique. It is shown that the inelastic magnon-assisted Andreev process would manifest itself as a nonlinear addition to the I(V) characteristics which is asymmetric with respect to the sign of the bias voltage and is related to the local density of states of magnons at the interface.
LINKED CLUSTER SERIES EXPANSIONS FOR TWO-PARTICLE STATES IN QUANTUM LATTICE MODELS
Authors: ZHENG WEIHONG , HAMER CHRIS J. , SINGH RAJIV R. P. , TREBST SIMON , MONIEN HARTMUT
Published: December 2003

We have developed strong-coupling series expansion methods to study the two-particle spectra in quantum lattice models. The properties of bound states and multiparticle excitations can reveal important information about the dynamics of a given model. At the heart of this method lies the calculation of an effective Hamiltonian in the two-particle subspace. We use an orthogonal transformation to perform this block diagonalising, and find that maintaining orthogonality is crucial for cases where the ground state and the two-particle subspace have identical quantum numbers. The two-particle Schrödinger equation is solved by using a finite lattice approach in coordinate space or an integral equation in momentum space. These methods allow us to determine precisely the low-lying excitation spectra and dispersion relations for the two-particle bound states. The method has been tested for the (1+1) D transverse Ising model, and applied to the two-leg spin-1/2 Heisenberg ladder. We study the coherence lengths of the bound states, and how they merge with the two-particle continuum. Finally, these techniques are applied to the frustrated alternating Heisenberg chain, which has been of considerable recent interest due to its relevance to spin-Peierls systems such as CuGeO 3. Starting from a limit corresponding to weakly-coupled dimers, we develop high-order series expansions for the effective Hamiltonian in the two-particle subspace. In the regime of strong dimerisation, various properties of the singlet and triplet bound states, and the quintet antibound states, can be accurately calculated. We also study the behaviour as the external bond alternation vanishes, and the way in which the bound states of triplet dimer excitations make the transition to a soliton-antisoliton continuum.
MAGNETIC EXCITATION OF ORTHOGONAL DIMER HEISENBERG SPIN SYSTEM FOR SrCu2(BO3)2
Authors: MIYAHARA S. , TOTSUKA K. , UEDA K.
Published: December 2003

SrCu 2( BO 3)2 is a new two-dimensional spin gap system and the magnetic behaviour of this compound is explained well by the two-dimensional orthogonal dimer Heisenberg model. Recently several excitations have been observed by inelastic neutron scattering and other experiments. We study features of these excitations by Lanczos method and perturbation technique. A triplet excitation has an almost localised nature. This localised character is observed as an almost flat band in neutron scattering. On the other hand, bound states of two triplet excitations, which have dispersive character, are stable in contrast to ordinary magnetic systems. We calculate the dynamic structure factor by a Lanczos method in finite systems and compare our results with experiments.
SUPERCONDUCTIVITY AND QUANTUM PHASE TRANSITIONS IN WEAK ITINERANT FERROMAGNETS
Authors: KIRKPATRICK T. R. , VOJTA THOMAS , BELITZ D. , NARAYANAN R.
Published: December 2003

It is argued that the phase transition in low Tc clean itinerant ferromagnets is generically of first order, due to correlation effects that lead to a nonanalytic term in the free energy. A tricritical point separates the line of first order transitions from Heisenberg critical behavior at higher temperatures. Sufficiently strong quenched disorder suppresses the first order transition via the appearance of a critical endpoint. A semi-quantitative discussion is given in terms of recent experiments on MnSi and UGe 2. It is then shown that the critical temperature for spin-triplet, p-wave superconductivity mediated by spin fluctuations is generically much higher in a Heisenberg ferromagnetic phase than in a paramagnetic one, due to the coupling of magnons to the longitudinal magnetic susceptibility. This qualitatively explains the phase diagram recently observed in UGe 2 and ZrZn 2.
THERMAL PHASES IN FINITE QUANTUM SYSTEMS
Authors: DEAN D. J.
Published: December 2003

I will describe the behaviour of two different quantum-mechanical systems as a function of increasing temperature. While these systems are somewhat different, the questions addressed are very similar, namely, how does one describe transitions in phase of a finite many-body system; how does one recognise these transitions in practical calculations; and how may one obtain the order of the transition.
THE MOTT TRANSITION AND F ELECTRON PHYSICS
Authors: KOTLIAR GABRIEL , SAVRASOV SERGEJ Y.
Published: December 2003

We revisit the issue of the Mott transition across the actinide series from the perspective of the spectral density functional approach to realistic dynamical mean-field theory. We stress both qualitative insights from the connection with models and quantitative results.
SCALING IN MANY-BODY SYSTEMS AND PROTON STRUCTURE FUNCTION
Authors: BENHAR OMAR
Published: December 2003

The observation of scaling in processes in which a weakly interacting probe delivers large momentum q to a many-body system simply reflects the dominance of incoherent scattering off target constituents. While a suitably defined scaling function may provide rich information on the internal dynamics of the target, in general its extraction from the measured cross section requires careful consideration of the nature of the interaction driving the scattering process. The analysis of deep inelastic electron-proton scattering in the target rest frame within standard many-body theory naturally leads to the emergence of a scaling function that, unlike the commonly used structure functions F1 and F2, can be directly identified with the intrinsic proton response.
SATURATION PROPERTIES OF NUCLEAR MATTER AND CORRELATED NUCLEONS
Authors: DICKHOFF W. H. , ROTH E. P.
Published: December 2003

A brief overview is given of the properties of spectral functions in finite nuclei as obtained from ( e,e ′ p ) experiments. Based on recent experimental data from this reaction it is argued that the empirical value of the saturation density of nuclear matter is dominated by short-range correlations. This observation and the observed fragmentation and depletion of the single-particle strength in nuclei provide the motivation for attempting a self-consistent description of the nucleon spectral functions with full inclusion of short-range and tensor correlations in nuclear matter. Results for these "second generation" spectral functions will be discussed with emphasis on the consequences for the saturation properties of nuclear matter. Arguments are presented to clarify the obscuring role of pionic long-range correlations in this long-standing problem.
NUCLEAR MANY-BODY THEORY AT FINITE TEMPERATURE APPLIED TO A PROTONEUTRON STAR
Authors: MARRANGHELLO G. F. , VASCONCELLOS C. A. Z. , DILLIG M. , de FREITAS PACHECO J. A.
Published: December 2003

We describe the structure of the Sommerfeld approximation to the Walecka model. The approximation is also applied to an extended version of the Boguta and Bodmer model which takes hyperon and lepton degrees of freedom into account, including trapped neutrinos. We apply the results to the protoneutron star problem.
ON THE TWO-BODY MOMENTUM DISTRIBUTION IN FINITE NUCLEI
Authors: PAPAKONSTANTINOU P. , MAVROMMATIS E. , KOSMAS T. S.
Published: December 2003

We present compact analytic expressions for the two-body momentum distribution η2(p1, p2) in Z=N closed-shell nuclei derived within the context of the independent particle shell model. Results are derived for the nucleus 16 O . The effect of dynamical short-range correlations is estimated using Jastrow-type correlation functions in the case of the nucleus 4 He .
TICC2 STATE-DEPENDENT CORRELATIONS IN NUCLEI
Authors: MOLINER I.
Published: December 2003

We use the TICC2, a translationally invariant reformulation of the coupled cluster method (CCM) at the sub(2) level, to study finite nuclei within the p-shell. These nuclei were previously studied with the linearised TICI2 wave function, but the role of the higher order terms had not been discussed for nuclei. We shall include the quadratic terms of the wave function within a coordinate-space implementation of the method, and consider state-dependent correlations with the same structure as the semi-realistic interactions used. Using CCM techniques and gaussian expansions we compute the ground-state energies of these nuclei.
SPECTROSCOPY OF HIGH-K BANDS IN THE A=180 REGION USING A QUANTUM MANY-BODY METHOD
Authors: RATH ASWINI KUMAR , WALKER P. M. , PRAHARAJ C. R.
Published: December 2003

Using deformed Hartree–Fock and the angular momentum projection formalism, the nature of the first band crossings in the high spin structure of 182,184,186 Os , 181,183 Re and 181 Ta are studied. The degree of high-K mixing obtained in the calculation provides a microscopic understanding of the K-forbidden transitions from the high-K bandheads to the yrast states with low-K intrinsic structure.
EFFECTIVE NUCLEON-NUCLEON INTERACTION AND FERMI LIQUID THEORY
Authors: SCHWENK ACHIM , BROWN GERALD E. , FRIMAN BENGT
Published: December 2003

We present two novel relations between the quasiparticle interaction in nuclear matter and the unique low momentum nucleon-nucleon interaction in vacuum. These relations provide two independent constraints on the Fermi liquid parameters of nuclear matter. Moreover, the new constraints define two combinations of Fermi liquid parameters, which are invariant under the renormalisation group flow in the particle-hole channels. Using empirical values for the spin-independent Fermi liquid parameters, we are able to compute the major spin-dependent ones by imposing the new constraints as well as the Pauli principle sum rules.
QUANTUM FLUID MIXTURES IN DIFFERENT PHASES
Authors: SAARELA MIKKO , TAIPALEENMÄKI TAUNO
Published: December 2003

Variational theory of quantum fluid mixtures is presented with the emphasis on the stability and phase transitions. We give results on two systems where new interesting phases are predicted. Dilute mixtures of 3 He impurities in the liquid 4 He in two dimensions form loosely bound pairs, dimers. The binding energy of the dimer ranges from milli- to micro-Kelvins with increasing 4 He density. The dimerised mixture of 3 He atoms is stable up to maximum solubility of ≈3%. Electrons and holes in semiconductors form a homogeneous mixture, electron-hole liquid. We predict that at low densities this system becomes unstable against clustering of charges and a liquid phase with a mixture of bound charged clusters could be formed.
BOSE–EINSTEIN CONDENSATION AND EXCITATIONS IN SOLID 4He WITH VACANCIES
Authors: GALLI D. E. , REATTO L.
Published: December 2003

We have studied the ground state and excited state properties of solid 4 He on the basis of the variational shadow wave function technique (SWF), which allows for relaxation and delocalisation of vacancies. We have found that a finite concentration of vacancies, if present, induces Bose-Einstein condensation (BEC) of the atoms at density close to the T=0 K melting where vacancies are delocalised. No BEC is present in a perfect crystal or in a defected solid at higher densities. We have extended this technique to study longitudinal phonons in solid 4 He and to study the vacancy excitation at a finite momentum; we have been able to compute for the first time the vacancy excitation spectrum in solid 4 He at density close to melting. Our results give a band width of about 8 K.
STRUCTURE AND SPECTROSCOPY OF DOPED HELIUM CLUSTERS USING QUANTUM MONTE CARLO TECHNIQUES
Authors: VIEL ALEXANDRA , WHALEY K. BIRGITTA
Published: December 2003

We present a comparative study of the rotational characteristics of various molecule-doped 4 He clusters using quantum Monte Carlo techniques. The theoretical conclusions obtained from both zero and finite temperature Monte Carlo studies confirm the presence of two different dynamical regimes that correlate with the magnitude of the rotational constant of the molecule, i.e. fast or slow rotors. For a slow rotor, the effective rotational constant for the molecule inside the helium droplet can be determined by a microscopic two-fluid model in which helium densities computed by path integral Monte Carlo are used as input, as well as by direct computation of excited energy levels. For a faster rotor, the conditions for application of the two-fluid model for dynamical analysis are usually not fulfilled and the direct determination of excitation energies is then mandatory. Quantitative studies for three molecules are summarised, showing in each case excellent agreement with experimental results.
RENORMALISATION GROUP ANALYSIS OF THE TWO-DIMENSIONAL HUBBARD MODEL: SPIN CORRELATIONS AND D-WAVE SUPERCONDUCTIVITY
Authors: METZNER W.
Published: December 2003

The repulsive two-dimensional Hubbard model is analysed within a functional renormalisation group (RG) approach. The flow equation for the effective interactions is evaluated on 1-loop level. The effective interactions diverge at a finite energy scale which is exponentially small for small bare interactions. To analyse the nature of the instabilities signalled by the diverging interactions, we compute the flow of the superconducting susceptibilities for various pairing symmetries and also charge and spin density susceptibilities. Depending on the choice of the model parameters (hopping amplitudes, interaction strength and band-filling) we find spin density wave instabilities or d-wave superconductivity as leading instability close to half-filling. This calculation establishes the existence of d-wave superconductivity in the Hubbard model beyond doubt.
INTERMEDIATE HAMILTONIAN FOCK-SPACE COUPLED CLUSTER METHOD AND APPLICATIONS
Authors: LANDAU ARIE , ELIAV EPHRAIM , KALDOR UZI
Published: December 2003

An intermediate Hamiltonian Fock-space coupled cluster method is presented. This method allows the use of large and flexible P spaces without encountering intruder-state problems. The larger P spaces enhance the accuracy of calculated transition energies by factors of 3–6, and make accessible many states which could not be handled by other CC methods. Examples given include the pilot calculation on Sc + levels, where accuracy increased by a factor of 4; element 114, where ionisation potentials show considerable increase relative to lighter group-14 atoms, due to relativistic stabilisation of the 7s and 7p1/2 orbitals; and a benchmark calculation of the electron affinities of the alkali atoms Na–E119, where results agree within 5 meV or better with known experimental values, providing a new reference value of 491±5 meV for the experimentally unknown EA of Fr.
CLUSTER ALGORITHM SOLUTION OF SIGN AND COMPLEX ACTION PROBLEMS
Authors: WIESE U.-J
Published: December 2003

Numerical simulations of numerous quantum systems suffer from notorious sign or complex action problems. In such cases, the Boltzmann factors contributing to the path integral are in general not positive. As a consequence, standard Monte Carlo algorithms based on importance sampling fail. Meron-cluster algorithms realize a general strategy for solving sign problems by canceling explicitly all negative contributions. The remaining uncancelled positive contributions are then generated using importance sampling. The general nature of the sign problem is discussed and its solution with a meron-cluster algorithm is illustrated for staggered lattice fermions that undergo a chiral phase transition. A similar cluster algorithm is used to solve the complex action problem that arises in the Potts model approximation to dense Quantum Chromodynamics (QCD) with heavy quarks.
DENSITY-MATRIX RENORMALISATION GROUP FOR DYNAMIC CORRELATION FUNCTIONS
Authors: JECKELMANN E.
Published: December 2003

The calculation of dynamic correlation functions in quantum systems is formulated as a variational problem. For low-dimensional many-body systems this variational problem can be solved numerically using the density-matrix renormalisation group (DMRG). This dynamic DMRG method is demonstrated on the linear optical conductivity in the Mott insulating phase of the one-dimensional extended Hubbard model at half filling. The full optical spectrum of this model can be calculated almost exactly for chains with more than 100 sites, which is large enough to investigate the spectral properties in the thermodynamic limit. The accuracy of the method is illustrated by comparison with analytical results in the field-theoretical regime and in the strong-coupling limit.
NONLINEAR ELECTRON TRANSPORT THROUGH DOUBLE QUANTUM DOTS COUPLED TO CONFINED PHONONS
Authors: DEBALD STEFAN , BRANDES TOBIAS , KRAMER BERNHARD
Published: December 2003

The non-linear electron current through a double quantum dot embedded in a free standing quantum well is investigated. In such a model for a nano-size phonon cavity, the transport at low temperatures is mediated by the spontaneous emission of acoustic phonons. Phonon quantum size effects can be detected as steps in the current. Moreover, for our model we find van-Hove singularities in the phonon density of states that give rise to a strong, tuneable increase of phonon emission into characteristic modes. The emission characteristic, depending on the position of the dots in the cavity, is also considered.
COUPLED CLUSTER TECHNIQUES AND THE RABI HAMILTONIAN
Authors: EMARY CLIVE
Published: December 2003

The Rabi Hamiltonian is a simple, yet non-trivial model of light-matter interactions. Here we present a brief review of the application of the normal coupled cluster method (NCCM) to this model. We concentrate on the NCCM description of the excitation spectrum and of simple time evolutions of the system, providing a link between the two that limits the accuracy of NCCM dynamical calculations in practice.
The WHO classification of MDS does make a difference
Authors: Howe Robert B. , Porwit-MacDonald Anna , Wanat Robert , Tehranchi Ramin , Hellström-Lindberg Eva
Published: December 2003

The purpose of this study was to determine the facility and reliability of the World Health Organization (WHO) classification of myelodysplastic syndromes (MDSs) with several observers reviewing the same diagnostic specimens. We also wanted to determine if the WHO classification provided additional information about predictability of clinical response outcome. To accomplish these goals we reviewed 103 previously diagnosed cases of low-risk MDS. We found 92% interobserver agreement (P < .001). Sixty-four of these patients had been entered into clinical trials using growth factors by the Nordic MDS Study Group. The WHO classification reliably predicted therapeutic response to the combination of granulocyte colony-stimulating factor (G-CSF) and erythropoietin (Epo). The response rate differed significantly between refractory anemia with ringed sideroblasts (RARS) and refractory anemia with multilineage dysplasia and ringed sideroblasts (RCMD/RS) with regard to therapeutic response (75% versus 9%; P = .003). Also, in the group of patients with less than 5% marrow blasts, there was a difference in median survival between patients with unilineage dysplasia (51% surviving at 67 months) and those with multilineage dysplasia (median survival, 28.5 months; P = .03). (Blood. 2004;103:3265-3270)
Analysis of compressibility effects on Darrieus-Landau instability of deflagration
wave
Authors: L. He
Published: December 2003

The Darrieus-Landau instability of propagating fronts, such as the flame
front in combustion and ablation front in inertial confinement fusion, was
analyzed with considering compressibility effects. It was shown that the
assumption that the flame velocity is constant, relative to both the burned
and unburned gas, cannot be applied to determine correctly the compressibility
effect because it violates the conservation equations (Rankine-Hugoniot relation).
Using the jump conditions from the Rankine-Hugoniot relation, we obtained
a dispersion relation for the growth rate in terms of the wave number, the
Mach number, and the density ratio of the burned to unburned gas. It was
found that the growth rate first increases and then decreases with the Mach
number and that the Chapman-Jouguet deflagration appears to be neutrally
stable.
Morphological and functional maturation of a skeletal muscle regulated by juvenile hormone
Authors: Rose Uwe
Published: December 2003

Reproductive behaviour of animals requires a well-adapted muscular system. This study examines the structural and functional development of ovipositor muscle properties in female locusts during reproductive development. A possible regulation by juvenile hormone (JH) was assessed by comparing muscle properties in immature and mature females and with those whose JH production was inhibited by allatectomy early in adult life. The results are related to the reproductive behaviour of locusts.

Histological and ultrastructural comparison of muscle fibres and their associated cuticular structures (apodemes) revealed dramatic growth during the first 2 weeks of reproductive development. The cross-sectional area of muscle fibres increased sevenfold, and their mass-per-length 5.3-fold. Ultrastructural examination showed growth of mitochondria, development of sarcoplasmic reticulum and increasing levels of structural organisation of myofibrils. Muscles of mature females displayed pronounced fatigue resistance,contracted more powerfully (twitch, 33.22±10.8 mN; 50 Hz,623.66±115.77 mN) and had almost two times faster kinetics than those of immature females (twitch, 6.5±2.6 mN; 50 Hz, 14.19±2.58 mN). Together with muscular maturation, cuticular apodemes, which serve as attachment sides for ovipositor muscles, grow considerably in length and width and assume a complex surface structure. Most of the described changes were suppressed in females deprived of JH (allatectomised). The results demonstrate an adaptation of muscle properties to the requirements of reproductive behaviour that is largely regulated by juvenile hormone.
Walking and running in the red-legged running frog,Kassina maculata
Authors: Ahn A. N. , Furrow E. , Biewener A. A.
Published: December 2003

Although most frog species are specialized for jumping or swimming, Kassina maculata (red-legged running frog) primarily uses a third type of locomotion during which the hindlimbs alternate. In the present study,we examined Kassina's distinct locomotory mode to determine whether these frogs walk or run and how their gait may change with speed. We used multiple methods to distinguish between terrestrial gaits: the existence or absence of an aerial phase, duty factor, relative footfall patterns and the mechanics of the animal's center of mass (COM). To measure kinematic and kinetic variables, we recorded digital video as the animals moved over a miniature force platform (N=12 individuals). With respect to footfall patterns, the frogs used a single gait and walked at all speeds examined. Duty factor always exceeded 0.59. Based on COM mechanics, however, the frogs used both walking and running gaits. At slower speeds, the fluctuations in the horizontal kinetic energy (Ek) and gravitational potential energy (Ep) of the COM were largely out of phase,indicating a vaulting or walking gait. In most of the trials, Kassinaused a combined gait at intermediate speeds, unlike cursorial animals with distinct gait transitions. This combined gait, much like a mammalian gallop,exhibited the mechanics of both vaulting and bouncing gaits. At faster speeds,the Ek and Ep of Kassina's COM were more in phase, indicating the use of a bouncing or running gait. Depending on the definition used to distinguish between walking and running, Kassina either only used a walking gait at all speeds or used a walking gait at slower speeds but then switched to a running gait as speed increased.
Acoustic communication in noise: regulation of call characteristics in a New World monkey
Authors: Brumm Henrik , Voss Katrin , Köllmer Ireen , Todt Dietmar
Published: December 2003

This study on common marmosets Callithrix jacchus is the first to examine noise-dependent mechanisms of vocal plasticity in a New World monkey. Since acoustic communication can be considerably impaired by environmental noise, some animals have evolved adaptations to counteract its masking effects. The studied marmosets increased the sound level of their spontaneous calls in response to increased levels of white noise broadcast to them. Possibly, such noise-dependent adjustment of vocal amplitude serves to maintain a specific signal-to-noise ratio that is favourable for signal production. Concurrently, the adjustment of vocal amplitude can maintain a given active space for communication. In contrast to some bird species, no noise-induced increase in the number of syllables per call series could be found, showing that an increased serial redundancy of vocal signals was not used to communicate under noisy conditions. Finally, we examined a possible noise-dependent prolongation of vocal signals. This approach was guided by the findings of perceptional studies, which suggest an increased detection probability of prolonged signals in noise by temporal summation. Marmosets indeed increased the duration of their call syllables along with increasing background noise levels. This is the first evidence of such mechanism of vocal plasticity in an animal communication system.