bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethical issues in using a cocaine vaccine to treat and prevent cocaine abuse and dependence
Authors: Hall W , Carter L
Published: August 2004

A “cocaine vaccine” is a promising immunotherapeutic approach to treating cocaine dependence which induces the immune system to form antibodies that prevent cocaine from crossing the blood brain barrier to act on receptor sites in the brain. Studies in rats show that cocaine antibodies block cocaine from reaching the brain and prevent the reinstatement of cocaine self administration. A successful phase 1 trial of a human cocaine vaccine has been reported. The most promising application of a cocaine vaccine is to prevent relapse to dependence in abstinent users who voluntarily enter treatment. Any use of a vaccine to treat cocaine addicts under legal coercion raises major ethical issues. If this is done at all, it should be carefully trialled first, and only after considerable clinical experience has been obtained in using the vaccine to treat voluntary patients. There will need to be an informed community debate about what role, if any, a cocaine vaccine may have as a way of preventing cocaine addiction in children and adolescents.
Why it is not strongly irrational to have children
Authors: Holm Søren
Published: August 2004

Response to: A rational cure for prereproductive stress syndrome
Response to: A rational cure for pre-reproductive stress syndrome
Authors: Aksoy S
Published: August 2004

This response to “A rational cure for pre-reproductive stress syndrome” first suggests it is existence that is essential and prerequisite to everything good or bad, therefore it deserves to be protected and respected. Secondly, it argues that every life is worth living, even if it is worse than some other lives, if the only alternative is non-existence. Finally, it takes a critical view of and challenges Häyry’s suggestion that in a good clinical situation, the idea of the irrationality of having children could be a legitimate part of the guidance given, since it is not the counsellor’s or doctor’s duty to advise a couple who wish to have children that it is irrational or even immoral to bring a child into life.
Who owns a dead man’s sperm?
Authors: Cannold L
Published: August 2004

A sad outcome, but the right one
‘Til Death Us Do Part: the ethics of postmortem gamete donation
Authors: Parker M J
Published: August 2004

Couples need to make their wishes explicit if we are to allow postmortem gamete donation
Further ethical and social issues in using a cocaine vaccine: response to Hall and Carter
Authors: Ashcroft R E , Franey C
Published: August 2004

Evaluation of the potential of a cocaine vaccine requires a detailed understanding of the intended and unintended social consequences of its use. Prospective technology assessment is always difficult, but in the case of treatment and prevention of cocaine addiction we need to understand not only the neuroscience and pharmacology of cocaine addiction, but also social attitudes to drug use and addiction, the social context of drug use, and the factors which make drug use a rational strategy for an addict and make treatment seeking or relapse more or less likely. By considering different scenarios related to differing levels of effectiveness of the vaccine, the authors argue that vaccination will be at best a useful adjunct to existing methods of treatment, rather than a substitute for them.
Fish-habitat modeling for gap analysis to conserve the endangered Topeka shiner (Notropis topeka)
Authors: Wall Steven S , Berry, Jr. Charles R , Blausey Carmen M , Jenks Jonathan A , Kopplin Chad J
Published: August 2004

Decision support tools that predict fish distribution over broad spatial scales are needed to assist in planning watershed management and endangered species recovery. We developed a geographical information system model with multivariate logistic regression to rank valley segments for probable occurrence of the endangered Topeka shiner (Notropis topeka) using stream condition variables (stream size, groundwater potential, channel slope, streamflow, network position) and land-cover variables (percent pasture, percent trees) in streams characteristic of the North American Great Plains. The stream condition and land-cover models correctly classified 89% and 68% of outcomes (i.e., presence or absence), respectively. Field tests of maps of predicted species distribution resulted in more species occurrences than expected in valley segments classified as high potential for presence and less than expected in low-potential valley segments. Gaps between high-priority segments and protected land parcels were found in all basins. In 37 basins with Topeka shiners, protected land coverage was <1% in 17 basins, 15% in 10 basins, and 521.8% in 10 basins. Conservation activities in gaps are long-term conservation measures, but maps of predicted species distribution have many immediate applications.
Abundance of minke whales (Balaenoptera acutorostrata) in the Northeast Atlantic: variability in time and space
Authors: Skaug Hans J , Øien Nils , Schweder Tore , Bøthun Gjermund
Published: August 2004

Regional sighting surveys with two independent observers on each vessel were conducted each year from 1996 to 2001. Northern minke whales (Balaenoptera acutorostrata) are mostly solitary animals and are only available for observation at moments when they surface to breath. Thus, a stochastic point process model is developed for how the data are generated. The hazard probability of initially sighting a whale that surfaces depends on relative spatial coordinates and on other covariates. The parameters of the model are estimated by maximum likelihood. To account for interannual variation in spatial distribution of minke whales, a random effects model is developed and estimated by comparing current and past (1989 and 1995) survey data. A simulation approach is taken to remove bias from parameter estimates and to assess the uncertainty in the results. For total abundance, the result is a log-normal confidence distribution with quantiles 107 205·exp(0.137z), i.e., an abundance estimate of 107 205 with a coefficient of variation of ≈0.14. Together with these and earlier survey data, past data on catch, markrecapture, and satellite tracking are reviewed to elucidate distribution and migration patterns in Northeastern Atlantic minke whales.
Grazercollector facilitation hypothesis supported by laboratory but not field experiments
Authors: Heard Stephen B , Buchanan Corinne K
Published: August 2004

Grazing invertebrates in streams feed by harvesting algal cells from surfaces, and in doing so release fine particulate organic matter (FPOM). The "grazercollector facilitation hypothesis" holds that FPOM production by grazers facilitates growth and (or) survival of FPOM-collecting invertebrates. We tested for grazercollector facilitation in laboratory and field experiments. In recirculating flumes in the laboratory, we tested for facilitation of the collector Hydropsyche slossonae by the grazers Physa gyrina, Glossosoma intermedium, and Baetis tricaudatus. All three grazers increased FPOM levels in flume water, but only Physa facilitated Hydropsyche growth. In the field, we manipulated Physa and Glossosoma densities to test for facilitation (at a local scale) of natural collector assemblages in an eastern Iowa stream. We did not detect facilitation of any collector by either grazer in the field, despite high power to detect such interactions. We suspect that grazercollector facilitation was not observed in the field because (unlike in our laboratory flumes) field FPOM levels are often high and extremely variable in time and space and because organic particles can arise from sources other than grazer activity (= grazer-independent processing). Therefore, at local scales, collectors may not be significantly limited by the supply of grazer-derived FPOM.
Influence of river speed on path selection by migrating adult sockeye salmon (Oncorhynchus nerka)
Authors: Standen Emily M , Hinch Scott G , Rand Peter S
Published: August 2004

We applied stereovideographic techniques to investigate path selection, ground speed, and swimming speed in adult sockeye salmon (Oncorhynchus nerka) ascending the Seton River, British Columbia. We tracked three-dimensional trajectories of salmon through 10 reaches and characterized the current profile at each site. At sites with relatively slow currents, the encountered river current speeds along the fish's trajectory were significantly lower than the mean current speed of the site. However, at higher current speed sites, fish experienced current speeds at or above the average current speed of the site and increased their ground speed through these sites. Observed in situ swimming speeds were 1.476.0 times greater than swimming speeds expected based on tailbeat frequency  swimming speed predictive relationships established in flume studies. We conclude that (i) at sites with relatively slow or moderate current speeds, fish minimize exposure to high-speed currents to minimize energy expenditure, (ii) at sites with high-speed currents, fish may change their migration strategy, minimizing time spent searching for low current speed pathways and increasing their ground speed to expedite passage, and (iii) laboratory-derived predictive equations may only be appropriate for predicting in situ swimming costs at sites with moderate and linearly flowing currents.
The influence of oceanic and lagoonal plume waters on otolith chemistry
Authors: Patterson Heather M , Kingsford Michael J , McCulloch Malcolm T
Published: August 2004

To determine how ocean and lagoonal plume waters from within the same reef were reflected in the chemical composition of otoliths, we conducted an experiment over three consecutive summers where conditions of temperature and food were held constant. Presettlement Pomacentrus coelestis were held in replicate tanks of the two water masses for 9 days. The sagittae were then analyzed at high spatial resolution (5 µm × 50 µm × 4 µm) using laser ablation inductively coupled plasma mass spectrometry. Ba/Ca and Sr/Ca varied between water masses and the rank of these elemental ratios changed among years. Although the reason for this change in rank is not known, likely mechanisms include upwelling and (or) the episodic appearance of phytoplankton blooms inside the lagoon. This is the first demonstration that the elemental signatures of otoliths can vary significantly over small spatial scales in reef systems in the absence of confounding factors, thus complicating studies attempting to discriminate reef-based stocks or elucidate natal origins using otolith chemistry.
Effect of age and temperature on amino acid composition and the content of different protein types of juvenile Atlantic cod (Gadus morhua) otoliths
Authors: Hüssy K , Mosegaard H , Jessen F
Published: August 2004

The purpose of this study was to analyse the amino acid composition of otolith matrix protein, estimate the proportion of the water-soluble protein fraction, and analyse the effect of matrix composition on otolith visual appearance. Juvenile Atlantic cod (Gadus morhua) were reared under constant temperature and feeding conditions and sampled at the beginning and the end of the experiment. The amino acid composition was dominated by asparagine, glutamic acid, leucine, serine, and proline. A change in amino acid composition was observed with increasing temperature and time, caused by changing proportions of the water-soluble and -insoluble protein fractions. Feeding level had no effect. The relative content of water-soluble protein was linearly related to fish dry weight and temperature. Otolith opacity, defined as the percentage of incident light absorbed by an otolith section, did not differ significantly between experimental treatments. The soluble protein fraction had a positive, albeit insignificant, correlation with opacity. Using opacity and otolith volume, deposited total otolith protein content was estimated with an R2 of 0.91, where otolith volume alone explained 83% of the observed variation.
Atlantic cod (Gadus morhua) growth and otolith accretion characteristics modelled in a bioenergetics context
Authors: Hüssy K , Mosegaard H
Published: August 2004

The purpose of this work is to present a conceptual model for fish otolith growth in which somatic growth is related to otolith growth and opacity. The model is based on known mechanisms of CaCO3 and protein incorporation into the otolith. Model parameters were derived from laboratory experiments and from the literature. A sensitivity analysis showed that the model was robust to measurement errors in most input parameters. The most sensitive parameters were the exponents of the otolith lengthweight and otolith protein  whole-body protein synthesis relationships and the proportionality constant between metabolism and otolith growth rate. Application to experimental data resulted in good agreement between back-calculated and observed fish sizes. In the growth experiment, the average back-calculated weights were slightly lower than the average observed weights, but the correlation was highly significant. In the starvation experiment, the back-calculated weights were also highly correlated with observed weights, with slightly declining residuals with fish size. Unlike previous back-calculation methods, this model has the ability to detect periods of starvation and estimate growth histories in both growing and starving fish.
An age-structured assessment model for chinook salmon (Oncorhynchus tshawytscha)
Authors: Savereide James W , Quinn II Terrance J
Published: August 2004

Age-structured assessment models are rarely used for estimating the abundance of exploited salmon stocks. We developed such a model for a chinook salmon (Oncorhynchus tshawytscha) population in the Copper River, Alaska. Information consisted of catch-age data from three fisheries (commercial, recreational, and subsistence) and two sources of auxiliary data (escapement index and spawnerrecruit relationship). Model parameters included brood-year returns, proportions of a brood year returning at age and year, annual exploitation rates, gear selectivity, spawnerrecruit parameters, and a calibration parameter for the escapement index. Results suggested that population parameter estimates with high precision and low bias were produced by an approach that considered measurement error in the pooled catch-age data from all three fisheries and brood-year return proportions that varied over time. A sensitivity analysis revealed that brood-year return, catch, and escapement index estimates were insensitive to large changes in data weightings. The absence of strong deviations in the retrospective patterns of the brood-year returns suggested that there were no serious model misspecifications. The model integrated all sources of available information, accounted for uncertainty, and provided estimates of optimal escapement and its associated exploitation level. We believe that the model has broad application for use in assessments of chinook salmon systems.
Factors influencing stream temperatures in small streams: substrate effects and a shading experiment
Authors: Johnson Sherri L
Published: August 2004

The temperature of stream water is an important control of many in-stream processes. To better understand the processes and consequences of solar energy inputs to streams, stream temperature dynamics were examined before, during, and after experimental shading of a 150-m reach of a second-order stream in the Oregon Cascade Range. Maximum water temperatures declined significantly in the shaded reach, but minimum and mean temperatures were not modified. Heat budget calculations before shading show the dominance of solar energy as an influence of stream temperature. The influence of substrate type on stream temperature was examined separately where the water flowed first over bedrock and then through alluvial substrates. Maximum temperatures in the upstream bedrock reach were up to 8.6 °C higher and 3.4 °C lower than downstream in the alluvial reach. Better understanding of factors that influence not only maximum but minimum temperatures as well as diurnal temperature variation will highlight types of reaches in which stream temperature would be most responsive to changes in shading. Many apparent discrepancies in stream temperature literature can be explained by considering variation in the relative importance of different stream temperature drivers within and among streams and over time.
Quantitative reconstruction of past salinity variations in African lakes: assessment of chironomid-based inference models (Insecta: Diptera) in space and time
Authors: Verschuren Dirk , Cumming Brian F , Laird Kathleen R
Published: August 2004

Faunal records of 20 common midge species (Diptera: Chironomidae) in 32 African surface waters with salinities ranging from 20 to 41 000 µS·cm1were used to develop inference models for quantitative reconstruction of past salinity variations from larval chironomid fossils preserved in lake sediments. Weighted-averaging regression and calibration models using presenceabsence data (P/A) and presenceabsence data with tolerance down-weighting (P/Atol) produced bootstrapped coefficients of determination (r2) of 0.78 and 0.81, respectively, and root mean squared errors (RMSE) of prediction of 0.42 and 0.39 log conductivity units. Historical conductivity data from African lakes are scarce. Therefore, model performance was tested in time by comparing chironomid-inferred conductivity estimates with the corresponding diatom-inferred estimates in sediment records of two fluctuating lakes in the Rift Valley of Kenya. A hybrid procedure in which presenceabsence calibration models were applied to abundance-weighted fossil data yielded significantly higher correlation between chironomid- and diatom-inferred time series (Lake Oloidien AD 18801991, r2 = 0.760.78; Crescent Island Crater AD 9001993, r2 = 0.560.61) than by applying the same models to presenceabsence fossil data (r2 = 0.470.56 and 0.260.42, respectively). Overall, model performance confirms that Chironomidae are valuable bioindicators for natural and man-made changes in the water balance of African lakes.
Landscape models to understand steelhead (Oncorhynchus mykiss) distribution and help prioritize barrier removals in the Willamette basin, Oregon, USA
Authors: Steel E Ashley , Feist Blake E , Jensen David W , Pess George R , Sheer Mindi B , Brauner Jody B , Bilby Robert E
Published: August 2004

We use linear mixed models to predict winter steelhead (Oncorhynchus mykiss) redd density from geology, land use, and climate variables in the Willamette River basin, Oregon. Landscape variables included in the set of best models were alluvium, hillslope < 6%, landslide-derived geology, young (<40 years) forest, shrub vegetation, agricultural land use, and mafic volcanic geology. Our approach enables us to model the temporal correlation between annual redd counts at the same site while extracting patterns of relative redd density across sites that are consistent even among years with varying strengths of steelhead returns. We use our model to predict redd density (redds per kilometre) upstream of 111 probable migration barriers as well as the 95% confidence interval around the redd density prediction and the total number of potential redds behind each barrier. Using a metric that incorporates uncertainty, we identified high-priority barriers that might have been overlooked using only stream length or mean predicted fish benefit and we clearly differentiated between otherwise similar barriers. We show that landscape features can be used to describe and predict the distribution of winter steelhead redds and that these models can be used immediately to improve decision-making for anadromous salmonids.
Effects of an invasive bivalve (Dreissena polymorpha) on fish in the Hudson River estuary
Authors: Strayer David L , Hattala Kathryn A , Kahnle Andrew W
Published: August 2004

Despite predictions that the zebra mussel (Dreissena polymorpha) invasion of North America would damage fisheries, analyses of actual effects on fish have been few and equivocal. We analyze 26 years of data on fish populations in the Hudson River to quantify changes associated with the zebra mussel invasion. Based on our measurements of changes in the lower food web, we predicted that populations of open-water fish species (e.g., Alosa spp.) would suffer and populations of littoral fish species (e.g., Centrarchidae) would prosper from the zebra mussel invasion. We found that the median decrease in abundance of open-water species was 28%, whereas the median increase in abundance of littoral species was 97%. Populations of open-water species shifted downriver away from the zebra mussel population, whereas those of littoral species shifted upriver. Median apparent growth rates fell by 17% among open-water species and rose by 12% in the single littoral species studied. Many of the observed changes were large and involved species of commercial or recreational importance (e.g., American shad (Alosa sapidissima), black basses (Micropterus spp.)). The influence of zebra mussels on fish should vary widely across ecosystems as a function of system morphology, factors that limit primary production, and diets of the fish species.
Acute cadmium biotic ligand model characteristics of laboratory-reared and wild yellow perch (Perca flavescens) relative to rainbow trout (Oncorhynchus mykiss)
Authors: Niyogi S , Couture P , Pyle G , McDonald D G , Wood C M
Published: August 2004

This study evaluated the >400-fold tolerance to acute waterborne Cd of a metal-tolerant fish, yellow perch (YP, Perca flavescens), relative to a sensitive model fish, rainbow trout (RBT, Oncorhynchus mykiss), from the perspective of the acute Cd biotic ligand model (BLM). Three-hour gill binding characteristics for Cd and its competitor, Ca, in both species exhibited only small quantitative differences, but gill Cd accumulations at 3 h and 24 h, which were associated with 50% lethality at 96 h (3- and 24-h LA50s), were 52- to 60-fold higher in YP relative to RBT. However, the acute Cd BLM cannot be extended from RBT to YP by simple adjustments of LA50 values because unlike RBT, in YP, LA50s (3 and 24 h) were 26- to 47-fold greater than the capacity of the characterized set of Cd-binding sites. Moreover, 3-h gill Ca and Cd binding characteristics in wild YP, collected from one clean (Geneva) and two metal-contaminated softwater lakes (Hannah and Whitson) around Sudbury region, northern Ontario, revealed that chronic waterborne factors like hardness and Cd preexposure can influence both Cd and Ca binding in fish gills and could have major implications for the future refinement of the acute Cd BLM approach.
A Bayesian hierarchical analysis of stockrecruit data: quantifying structural and parameter uncertainties
Authors: Michielsens Catherine GJ , McAllister Murdoch K
Published: August 2004

Stockrecruit functions are important in fisheries stock assessment, but there is often uncertainty surrounding the appropriate stockrecruit model and its parameter values. Combining different stockrecruit data sets of related species through Bayesian hierarchical analysis can decrease these uncertainties and help to characterize appropriate stockrecruit forms and ranges of plausible parameter values. Two different stockrecruit functions (BevertonHolt and Ricker) have been parameterized in terms of the steepness, which is a parameter that is comparable between populations. In the hierarchical analysis, the prior probability distribution of parameters for the cross-population variation in steepness is determined through a concise model structure. By calculating the Bayes' posteriors for alternative model forms, model uncertainty is accounted for. This methodology has been applied to Atlantic salmon (Salmo salar) stockrecruit data to provide predictions for the steepness of the stockrecruit function for Baltic salmon for which no stockrecruit data exist.
A Bayesian hierarchical formulation of the De Lury stock assessment model for abundance estimation of Falkland Islands' squid (Loligo gahi)
Authors: McAllister Murdoch K , Hill Simeon L , Agnew David J , Kirkwood Geoffrey P , Beddington John R
Published: August 2004

In stock assessments of short-lived species, De Lury depletion models are commonly applied in which commercial catches and changing catch rates are used to estimate resource abundance. These methods are applied within fishing seasons to decide when to close the fishery and can be reliable if the data show a distinct decline in response to the catch removals. However, this is not always the case, particularly when sampling error variation masks trends in abundance. This paper presents a Bayesian hierarchical formulation of the De Lury model in which data from previous years are combined hierarchically in the same stock assessment model to improve parameter estimation for future stock assessments. The improved precision in parameter estimates is demonstrated using data for the Falkland Islands' Loligo gahi squid fishery.
Ecological correlates of fish movement in a network of Virginia streams
Authors: Albanese Brett , Angermeier Paul L , Dorai-Raj Sundar
Published: August 2004

Identifying factors that influence fish movement is a key step in predicting how populations respond to environmental change. Using markrecapture (four species) and trap capture (eight species) data, we examined relationships between three attributes of movement and 15 ecological variables. The probability of emigrating from a reach was positively related to intermittency (one species) and body size (one species) and negatively related to distance from the mainstem creek (two species) and habitat complexity (one species). The number of fish moving upstream through traps was positively related to increases in flow (five species), day length (three species), and water temperature (two species); the number moving through downstream traps was positively associated with increases in flow (three species). Distance moved was greater for fish moving through unsuitable reaches (one species). Floods have a pervasive effect on fish movement, and human activities that affect flows will have widespread implications. The importance of other factors varies interspecifically, which may translate into variation in persistence and colonization rates. For example, species that exhibit reach fidelity in complex habitats may increase movement if habitats are homogenized. These species may suffer population declines because of the cost of increased movement and may ultimately be replaced by ecological generalists.
THEORETICAL STUDIES ON NONLINEAR INTERACTION BETWEEN LASER AND BIO-MOLECULES IN OPTICAL TOMOGRAPHY
Authors: YAO DUANZHENG , XIONG GUIGUANG
Published: August 2004

The nonlinear interaction between laser and bio-molecule has been studied by the theory of molecular nonlinear polarization. The expressions of operators of Hamiltonian, the moment of dipole and the electric susceptibility with different orders have been evaluated. The contributions of electrons and nuclei to the molecular polarization have been analyzed. A SHG tomography induced by third-order nonlinear optical effect has also been proposed.
Transepithelial HCO3− absorption is defective in renal thick ascending limbs from Na+/H+ exchanger NHE1 null mutant mice
Authors: Good David W. , Watts Bruns A. , George Thampi , Meyer Jamie W. , Shull Gary E.
Published: August 2004

In the medullary thick ascending limb (MTAL) of rat kidney, inhibiting basolateral Na+/H+ exchange with either amiloride or nerve growth factor (NGF) results secondarily in inhibition of apical Na+/H+ exchange, thereby decreasing transepithelial HCO3− absorption. To assess the possible role of the Na+/H+ exchanger NHE1 in this regulatory process, MTALs from wild-type and NHE1 knockout (NHE1−/−) mice were studied using in vitro microperfusion. The rate of HCO3− absorption was decreased 60% in NHE1−/− MTALs (15.4 ± 0.5 pmol·min−1·mm−1 wild-type vs. 6.0 ± 0.5 pmol·min−1·mm−1 NHE1−/−). Transepithelial voltage, an index of the NaCl absorption rate, did not differ in wild-type and NHE1−/− MTALs. Basolateral addition of 10 μM amiloride or 0.7 nM NGF decreased HCO3− absorption by 45–49% in wild-type MTALs but had no effect on HCO3− absorption in NHE1−/− MTALs. Inhibition of HCO3− absorption by vasopressin and stimulation by hyposmolality, both of which regulate MTAL HCO3− absorption through primary effects on apical Na+/H+ exchange, were similar in wild-type and NHE1−/− MTALs. Thus the regulatory defect in NHE1−/− MTALs is specific for factors (bath amiloride and NGF) shown previously to inhibit HCO3− absorption through primary effects on basolateral Na+/H+ exchange. These findings demonstrate a novel role for NHE1 in transepithelial HCO3− absorption in the MTAL, in which basolateral NHE1 controls the activity of apical NHE3. Paradoxically, a reduction in NHE1-mediated H+ extrusion across the basolateral membrane leads to a decrease in apical Na+/H+ exchange activity that reduces HCO3− absorption.
Backward adaptive biorthogonalization
Authors: Rebollo-Neira L.
Published: August 2004

A backward biorthogonalization approach is proposed, which
modifies biorthogonal functions so as to generate orthogonal
projections onto a reduced subspace. The technique is relevant to
problems amenable to be represented by a general linear model. In
particular, problems of data compression, noise reduction, and
sparse representations may be tackled by the proposed approach.
The differential geometry of almost Hermitian almost contact metric submersions
Authors: Tshikuna-Matamba T.
Published: August 2004

Three types of Riemannian submersions whose total space is an
almost Hermitian almost contact metric manifold are studied. The
study is focused on fundamental properties and the transference
of structures.
On hereditary interval algebras
Authors: Alami M. , Zhani D.
Published: August 2004

We show that each hereditary
interval algebra has a countable density and not conversely.
Moreover, we show that, for an interval algebra, having countable
density and being subalgebra of the interval algebra over the real
line are equivalent statements.
Restricted partitions
Authors: Jakimczuk Rafael
Published: August 2004

We prove a known partitions theorem by Bell in an elementary and
constructive way. Our proof yields a simple recursive method to
compute the corresponding Sylvester polynomials for the
partition. The previous known methods to obtain these polynomials
are in general not elementary.
Maximum principle and its extension for bounded control problems with boundary conditions
Authors: Vasilieva Olga
Published: August 2004

This note is focused on a bounded control problem
with boundary conditions. The control domain need not be convex.
First‐order necessary condition for optimality is obtained in the
customary form of the maximum principle, and second‐order
necessary condition for optimality of singular controls is
derived on the basis of second‐order increment formula using the
method of increments along with linearization approach.
The Poisson equation in homogeneous Sobolev spaces
Authors: Samrowski Tatiana , Varnhorn Werner
Published: August 2004

We consider Poisson′s equation in an n‐dimensional exterior
domain G(n ≥ 2) with a sufficiently smooth boundary. We
prove that for external forces and boundary values given in
certain Lq(G)‐spaces there exists a solution in the
homogeneous Sobolev space S2,q(G), containing functions
being local in Lq(G) and having second‐order derivatives in
Lq(G) Concerning the uniqueness of this solution we prove
that the corresponding nullspace has the dimension n + 1, independent of q.
Vanishing moments for scaling vectors
Authors: Ruch David K.
Published: August 2004

One advantage of scaling vectors over a single scaling function is
the compatibility of symmetry and orthogonality. This paper
investigates the relationship between symmetry, vanishing
moments, orthogonality, and support length for a scaling vector
Φ. Some general results on scaling vectors and vanishing
moments are developed, as well as some necessary conditions for
the symbol entries of a scaling vector with both symmetry and
orthogonality. If orthogonal scaling vector Φ has some kind
of symmetry and a given number of vanishing moments, we can
characterize the type of symmetry for Φ, give some
information about the form of the symbol P(z), and place some
bounds on the support of each ϕi. We then construct an
L2(ℝ) orthogonal, symmetric scaling vector with one
vanishing moment having minimal support.
Coefficient estimates for Ruscheweyh derivatives
Authors: Darus Maslina , Akbarally Ajab
Published: August 2004

We consider functions f, analytic in the unit disc and of the
normalized form . For
functions , the class of functions
involving the Ruscheweyh derivatives operator, we give sharp
upper bounds for the Fekete‐Szegö functional .
A remark on four‐dimensional almost Kähler‐Einstein manifolds with negative scalar curvature
Authors: Lemence R. S. , Oguro T. , Sekigawa K.
Published: August 2004

Concerning the Goldberg conjecture, we will prove a result
obtained by applying the result of Iton in terms of L2‐norm of the scalar curvature.
Periodic rings with finitely generated underlying group
Authors: Khazal R. , Dăscălescu S.
Published: August 2004

We study periodic rings that are finitely generated as groups. We
prove several structure results. We classify periodic rings that
are free of rank at most 2, and also periodic rings R such that
R is finitely generated as a group and R/t(R)≃ℤ. In this way, we construct new classes of periodic rings. We
also ask a question concerning the connection to
periodic rings that are finitely generated as rings.
Analysis of an age‐dependent SI epidemic model with disease‐induced mortality and proportionate mixing assumption: the case of vertically transmitted diseases
Authors: El-Doma M.
Published: August 2004

An SI epidemic model for a vertically as well as horizontally
transmitted disease is investigated when the fertility, natural
mortality, and disease‐induced mortality rates depend on age and
the force of infection corresponds to a special form of
intercohort transmission called proportionate mixing. We
determine the steady states and obtain explicitly computable
threshold conditions, and then perform stability analysis.
On multiple‐particle continuous‐time random walks
Authors: Becker-Kern Peter , Scheffler Hans-Peter
Published: August 2004

Scaling limits of continuous‐time random walks are used in
physics to model anomalous diffusion in which particles spread at
a different rate than the classical Brownian motion. In this
paper, we characterize the scaling limit of the average of
multiple particles, independently moving as a continuous‐time
random walk. The limit is taken by increasing the number of
particles and scaling from microscopic to macroscopic view. We
show that the limit is independent of the order of these limiting
procedures and can also be taken simultaneously in both
procedures. Whereas the scaling limit of a single‐particle
movement has quite an obscure behavior, the multiple‐particle
analogue has much nicer properties.
Periodic solutions of a delayed predator‐prey model with stage structure for predator
Authors: Xu Rui , Chaplain M. A. J. , Davidson F. A.
Published: August 2004

A periodic time‐dependent Lotka‐Volterra‐type predator‐prey model
with stage structure for the predator and time delays due to
negative feedback and gestation is investigated. Sufficient
conditions are derived, respectively, for the existence and global
stability of positive periodic solutions to the proposed model.
Blowup of solutions with positive energy in nonlinear thermoelasticity with second sound
Authors: Messaoudi Salim A. , Said-Houari Belkacem
Published: August 2004

This work is concerned with a semilinear thermoelastic system, where the heat flux is given by Cattaneo′s law instead of the usual Fourier′s law. We will improve our earlier result by showing that the blowup can be obtained for solutions with “relatively” positive initial energy. Our technique of proof is based on a method used by Vitillaro with the necessary modifications imposed by the nature of our problem.
Finite‐difference method for parameterized singularly perturbed problem
Authors: Amiraliyev G. M. , Kudu Mustafa , Duru Hakki
Published: August 2004

We study uniform finite‐difference method for solving first‐order
singularly perturbed boundary value problem (BVP) depending on a
parameter. Uniform error estimates in the discrete maximum norm
are obtained for the numerical solution. Numerical results
support the theoretical analysis.
Reissner‐Mindlin plate theory for elastodynamics
Authors: Wu Shen Rong
Published: August 2004

Existence and uniqueness of solution are proved for
elastodynamics of Reissner‐Mindlin plate model. Higher regularity
is proved under the assumptions of smoother data and certain
compatibility conditions. A mass scaling is introduced. When the
thickness approaches zero, the solution of the clamped
Reissner‐Mindlin plate is shown to approach the solution of a
Kirchhoff‐Love plate.
Statin and fibrate treatment of combined hyperlipidemia: the effects on some novel risk factors
Authors: Keber Irena , Žegura Branka , Simčič Saša , Božič Mojca , Fressart Martine , Stegnar Mojca , Šebeštjen Miran
Published: August 2004

The effects of cerivastatin and fenofibrate on proteins involved in haemostasis and on markers of inflammation were investigated in otherwise healthy middle-aged males with combined hyperlipidemia. Besides classical risk factors, other so-called novel risk factors for coronary artery disease are seen to be playing an increasingly important role in the development and progression of atherosclerosis. Thirty-eight males, aged 49 ± 5 years were randomised to 12 weeks treatment either with cerivastatin at a daily dose of 0.2 mg to 0.4 mg to achieve the LDL cholesterol goal of <3.0 mM, or with fenofibrate 250 mg daily. Fasting serum lipids, homocysteine, total and free tissue factor pathway inhibitor (TFPI), plasminogen activator inhibitor (PAI-1) and tissue plasminogen activator (t-PA) antigen and activity, C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were measured. No change in homocysteine level was observed in the cerivastatin group, while after fenofibrate administration it increased (p <0.0001).Total TFPI decreased significantly after cerivastatin (p = 0.002), but not after fenofibrate. Free TFPI did not decrease after either drug. Neither drug affected (t-PA) antigen and activity, while fenofibrate increased PAI-1 antigen (p <0.05) and activity (p <0.05). Cerivastatin decreased serum CRP values by 49.5% (p = 0.001), and fenofibrate by 29.8% (p = 0.03). The decreases of CRP in the two groups differed significantly (p = 0.04). IL-6 levels decreased significantly in the fenofibrate group (39%; p <0.0001), but not in the cerivastatin group (15%; p = 0.24) No significant decreases were observed for TNF-α. Cerivastatin had neutral effects on fibrinolysis, homocysteine or coagulation. On the other hand, fenofibrate increased PAI-1 antigen and activity and homocysteine, and did not affect coagulation. Both cerivastatin and fenofibrate reduced CRP levels, the decrease being significantly greater after cerivastatin. Fenofibrate also significantly decreased IL-6.
Inhibition of endothelial cell tube formation by the low molecular weight heparin, tinzaparin, is mediated by tissue factor pathway inhibitor
Authors: Mohamed S. , Mousa Shaker
Published: August 2004

Heparin and low molecular weight heparins (LMWHs) have both antithrombotic and anti-angiogenic activities. The antiangiogenic activity of LMWH may be associated with the release of endothelial tissue factor pathway inhibitor (TFPI), an important endogenous inhibitor of tissue factor/Factor VIIa (TF/fVIIa).To evaluate the effects of LMWH, tinzaparin, and TFPI in a model of angiogenesis-mediated processes, we compared the effects of tinzaparin, and recombinant TFPI in inhibiting either basic fibroblast growth factor-2 (FGF2) or TF/fVIIainduced endothelial cell tube formation in human umbilical vein endothelial cells (HUVEC).Our results show that tinzaparin and recombinant TFPI both blocked endothelial tube formation induced by either FGF2 or TF/fVIIa, in a concentration-dependent manner. Endothelial tube formation was only marginally inhibited by a potent and specific anti-Factor Xa, recombinant tick anticoagulant protein (rTAP). A monoclonal anti-TFPI antibody reversed the inhibitory effects of either tinzaparin or recombinant-TFPI on HUVEC tube formation. Tinzaparin fractions in the range of 8,000 to 12,600 Da were most effective in stimulating the release of TFPI from HUVEC. These results suggest that the inhibitory effect of the LMWH tinzaparin on endothelial tube formation is associated with stimulation of the release of TFPI, but not to anti-Factor Xa activity.
Mice deficient in tissue factor demonstrate attenuated intimal hyperplasia in response to vascular injury and decreased smooth muscle cell migration
Authors: Pyo Robert , Sato Yuichiro , Mackman Nigel , Taubman Mark
Published: August 2004

Tissue factor (TF) is the primary initiator of the coagulation cascade and is thought to play a key role in the generation of arterial thrombosis. Recent studies have suggested that TF mediates inflammatory processes in the arterial wall and may be an important regulator of intimal hyperplasia. We have employed genetically engineered mice (mTF−/−/hTF+) with markedly diminished TF activity (≈1% normal levels) to examine the role of TF in mediating the response to arterial injury. mTF−/−/hTF+ displayed a marked reduction in intimal hyperplasia (46% decrease in intimal area, 60% decrease in intimal/medial ratio) in response to femoral artery injury when compared to wild type controls. The decreased intimal hyperplasia seen in low TF mice was noted in a model of vascular injury not associated with significant thrombosis, suggesting that it may be mediated by non-procoagulant properties of TF. Smooth muscle cells from mTF−/−/hTF+ mice grew normally in response to serum, but exhibited a marked defect in cell migration in a modified Boyden chamber assay. In contrast, there was no difference in platelet derived growth factorinduced migration, suggesting that the effect of TF on smooth muscle cell migration is agonist dependent. These data suggest that TF may mediate intimal hyperplasia by regulating smooth muscle cell migration.
Compartment- and cell-specific expression of coagulation and fibrinolysis factors in the murine lung undergoing inhalational versus intravenous endotoxin application
Authors: Wygrecka Malgorzata , Markart Philipp , Ruppert Clemens , Kuchenbuch Tim , Fink Ludger , Bohle Rainer , Grimminger Friedrich , Seeger Werner , Günther Andreas
Published: August 2004

Intraalveolar and intravascular fibrin formation are typical hallmarks of acute inflammatory lung diseases, and may foster subsequent fibroproliferative events.We investigated the regulation and cellular sources of key coagulation and fibrinolysis factors in lungs undergoing compartmentalized challenge with endotoxin (LPS). BALB/c mice received 15ng LPS either by intravenous injection or by inhalation. Quantitative gene expression analysis (real-time RT-PCR) was performed for tissue factor (TF),TF pathway inhibitor (TFPI), tissue-type plasminogen activator (t-PA), urokinase-type-PA (u-PA), PA inhibitor-1 (PAI-1), and PAI-2 in peripheral white blood cells (PBC) as well as in alveolar macrophages (AM), type-II pneumocytes (ATII), endothelial cells (EC) and smooth muscle cells (SMC), all obtained by laser microdissection. Neither route of LPS administration caused substantial protein leakage or leukocyte recruitment into the alveolar space. Compartmentalized upregulation of procoagulant and downregulation of fibrinolytic activities was, however, observed in response to both modes of LPS challenge. Intraalveolar endotoxin, in particular, caused strong upregulation of TF (∼ 20-fold increase in gene expression) and PAI-2 (225-fold increase) in microdissected AM, upregulation of PAI-1 in microdissected ATII (300-fold increase) and EC (180-fold increase), upregulation of t-PA in EC (40-fold), and downregulation of u-PA in vascular smooth muscle cells. TFPI was largely unchanged in all cell types, and PBC showed no major gene regulatory response to inhaled endotoxin. We conclude that the lung possesses a cell-specific alveolar coagulation and fibrinolysis system, being independent of the vascular coagulation cascade and responding readily with enhanced procoagulant and anti-fibrinolytic activities to LPS challenge.
Seminal clotting and fibrinolytic balance: a possible physiological role in the male reproductive system
Authors: Greenfield Robert , Stewart Alistair , Birch Brian , Cooper Alan , Lwaleed Bashir
Published: August 2004

Semen contains enzymes and inhibitors of the haemostatic system as well as the high molecular weight seminal vesicle (HMW-SV) proteins. The former may have roles in seminal clotting and in liquefaction through “fibrinolytic” activity, which may ultimately affect fertility. Although a limited number of studies have addressed the subject, the role of clotting and fibrinolytic factors in semen remains poorly understood. The liquefaction time and the distribution of components vary across split ejaculates. This may have an important bearing on the way clotting/fibrinolytic factors in semen are assessed. Semen contains tissue factor (TF, Thromboplastin, CD142), which originates from the prostate and is associated with prostasomes. The function of TF (and prostasomes) in semen is still a matter for speculation. Recently the presence of minute amounts of factor VII in semen has been demonstrated but its importance is uncertain. Semen also contains a thrombin-like enzyme, prothrombin fragments 1 and 2 (F1+2), D-dimer (DD) and thrombin-antithrombin (TAT) complexes. The presence of several fibrinolytic factors has been demonstrated in semen but few questions about their potential impact on semen quality have been raised. Factors found include tissue plasminogen activator (t-PA), urinary plasminogen activator (u-PA) and plasmin. There are also traces of fibrinogen, plasminogen, plasminogen activator inhibitor-1 (PAI-1), factorVIII coagulant activity (VIII:c) and fibrin monomers. The co-ordinate expression of both TF and PAI-1 by decidual cells of the endometrium is believed to be important in maintaining haemostasis during endovascular trophoblast invasion. Kallikrein-like serine protease inhibitors including prostate specific antigen (PSA) are known to be present in semen at high concentrations. In semen PSA is also found in a complex form with protein C inhibitor (PCI) with mutually inhibitory consequences. A better understanding of the spectrum of coagulating and liquefaction agents in semen to include classical haemostatic processes and the pathogenesis resulting from any imbalances between or within either system may provide the basis for the development of more selective and efficient agents affecting global fertility. Here we review aspects of male reproductive physiology in the light of recent findings concerning conventional clotting/fibrinolytic systems in human semen with a view to stimulating further research.