bluuebunny/crossref_metadata_2025 huggingface dataset:
The Spread of Intravenous Drug Use and AIDS in a Neighborhood in Spain
Authors: Gamella Juan F.
Published: November 2004

This article traces the process of the adoption of intravenous drug use in a Madrid neighborhood between 1978 and 1990 and how that process influenced the local spread of HIV/AIDS. During this period, intravenous drug use reached massive proportions in Spain and became a main factor in the spread of HIV/AIDS in the country. Data collected on 245 intravenous drug users and the motives and circumstances of first intravenous drug use in 124 cases show a consistent pattern of social transmission, a high prevalence of HIV infection among drug users, and a high risk of infection for their partners and children. Contrary to prevalent stereotypes, often heroin was not the first drug injected.
Recent Italian Literature in Medical Anthropology (1989–92)
Authors: Beneduce Roberto
Published: November 2004

Medicine e magie: Le tradizioni popolari in Italia (Medicine and Magic: Folk Traditions in Italy). Tullio Seppilli, ed.

Médecine traditionnelle: Acteurs, itinéraires thérapeutiques. Piero Coppo and Arouna Keita, eds.

Profeti in città: Etnografia di quattro chiese indipendenti del Ghana (Town Prophets: Ethnography of Four Independent Churches in Ghana). Pino Schirripa.

Itinerari delle emozioni: Corpo e identità femminile nel Sannio campano (Itineraries of Emotions: Women's Bodies and Identity in Sannio, Campania). Mariella Pandolfi.

Sortilegio e delirio: Psicopatologia dell'emigrazione in prospettiva transculturale (Sorcery and Delusion: The Psychopathology of Emigration in Transcultural Perspective). Michele Risso and Wolfing Böker.
From Simple Technology to Complex Arena: Classification of Pap Smears, 1917–90
Authors: Clarke Adele E. , Casper Monica J.
Published: November 2004

This article explores historical constructions of Pap smear classification systems from 1917 to 1990. Using a social worlds/arenas analysis, we examine the perspectives and properties of all the major actors (both human and nonhuman) in the Pap smear arena, including implicated actors. Analytical emphasis is on interpretive struggles among different actors in this arena and centers on the consequences of such conflicts for global classificatory systems and on the global classificatory criteria. We describe some of the local clinical “work‐arounds” designed to resolve problems of classification standards in practice. In drawing theoretical conclusions, comparison is made between Pap smear classification systems and two other systems.
The Molecular Perspective: Morphine
Authors: Goodsell David S.
Published: November 2004

Learning Objectives

After completing this course, the reader will be able to:

Describe the role of morphine and the G protein signaling system in pain treatments.

Access and take the CME test online and receive 1 hour of AMA PRA category 1 credit at CME.TheOncologist.com
Capillary Electrophoresis of DNA
Authors: Smith Alan , Nelson Robert J.
Published: November 2004

Capillary electrophoresis (CE) is an alternative to conventional slab gel electrophoresis for the separation of DNA fragments. CE offers a number of advantages over slab gel separations in terms of speed, resolution, sensitivity, and data handling. Separation times are generally only a few minutes and the DNA is detected either by UV absorption or by fluorescent labeling. The quantity of DNA required for separation is in the nanogram range. Single‐base resolution can be obtained on fragments up to several hundred base pairs. In the presence of appropriate standards, fragments can be accurately sized based on relative electrophoretic mobility. A protocol for the analysis of synthetic oligonucleotides in a flowable matrix is described in this unit.
Transgenic Mouse Production By Zygote Injection
Authors: Conner David A.
Published: November 2004

This unit describes methods for the production of transgenic mice by injection of DNA into zygotes, including fertilized‐egg isolation, zygote injection, and oviduct reimplantation. Methods for the preparation of plasmid and BAC DNA suitable for microinjection are also presented.
Bone Marrow Engraftment Studies
Authors: Vnencak‐Jones Cindy L.
Published: November 2004

Bone marrow engraftment studies are used to evaluate the level of donor versus recipient cells in post‐transplant peripheral blood or bone marrow specimens. Unique fingerprints identified from recipient and donor DNA are used to determine the proportion of each contained within the total DNA extracted from the post‐transplant specimen. These percentages correspond to relative amounts of donor and recipient cells in the specimen. Engraftment studies are sequentially performed on transplant patients to closely monitor the levels of donor and recipient cells so that appropriate therapeutic intervention can proceed if and when needed. This unit will describe the use of fluorescent PCR for amplification of genomic short tandem repeats (STR). STR analysis is now considered the gold standard for engraftment studies and provides a quick and accurate assessment of the contribution of both donor and/or recipient hematopoietic cells in post‐transplantation specimens.
High‐Sensitivity Immunofluorescence/Flow Cytometry: Detection of Cytokine Receptors and Other Low‐Abundance Membrane Molecules
Authors: Zola Heddy
Published: November 2004

Cell marker identification by traditional phenotyping techniques is now considered straight‐forward and relatively uncomplicated. In immunofluorescence/flow cytometry, the sensitivity, or detection limit, depends on the reagents, staining, and instrument parameters. The sensitivity of the most commonly used procedures, based on fluorescein‐conjugated antibodies, ∼2000 molecules of target antigen per cell, which is adequate for most of the widely used leukocyte markers. However, measuring target antigens of low density has proven very difficult indeed. Flow cytometric immunofluorescence is capable of detecting 100 molecules of target antigen per cell in practical applications, provided that every step of the staining and analysis procedure is optimized for sensitivity. This level of sensitivity reveals staining not seen using conventional analytical procedures. This unit discusses the underlying principles of high‐sensitivity immunofluorescence and provides an excellent series of protocols for the practical detection of as few as 100 target antigen molecules per cell.
Contamination of natural and cultured mussels (Mytilus galloprovincialis) from the northern Adriatic Sea by tributyltin and dibutyltin compounds
Authors: Boscolo R. , Cacciatore F. , Berto D. , Marin M. G. , Giani M.
Published: November 2004

The levels of tributyltin (TBT) and dibutyltin (DBT) compounds were measured by gas chromatography ion‐trap mass spectrometry (GC–MS/MS) in natural and cultured mussels (Mytilus galloprovincialis) from the northern Adriatic Sea in spring 2003. The highest (725 ng g−1 dry weight) and lowest levels (198 ng g−1 dry weight) of butyltins (TBT + DBT) were found in native mussels from the Lagoon of Venice, with the higher values being detected in specimens collected next to a dockyard and the lower values in specimens from a location characterized by strong water exchanges between the lagoon and the Adriatic Sea. The two cultured samples exhibited intermediate concentrations, with marine harvested samples being more contaminated than those from the lagoon.

Concentrations of TBT were higher than those of DBT for several reasons: the limited capability of bivalves to metabolize TBT and their ability to accumulate it (with recent input of TBT into the environment as TBT‐based anti‐fouling paints being the most important contributor of organotin contamination in our study area); and higher lipophilicity of TBT than DBT. In order to find correlations between organotin pollution and the state of nourishment of the mussels, the condition index was also evaluated as the mass ratio of meat dry weight to shell dry weight. There was no correlation between condition index and butyltin concentrations. These results indicate that condition index could not give information about stress conditions, as the contamination level is probably too low to cause significant reductions in mussel growth. Copyright © 2004 John Wiley & Sons, Ltd.
Infrared and mass spectrometry studies of the thermal decomposition of a nitro‐aromatic polymer
Authors: White Daniel R. , White Robert L.
Published: November 2004

The thermal decomposition reactions of a novel nitro‐aromatic polymer were investigated. Infrared spectroscopy was used to detect chemical structure changes that occurred in the solid material when it was heated. Mass spectrometry was employed to identify volatile products. The polymer decomposition mechanisms involved reactions between nitro groups and nearby methyl or methylene functionalities and primarily resulted in the formation of nitrogen monoxide gas and hydroxyl and carbonyl groups in the solid residue. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 351–357, 2005
Photostabilization of polycarbonate by ZnO coatings
Authors: Moustaghfir A. , Rivaton A. , Tomasella E. , Mailhot B. , Cellier J. , Jacquet M. , Gardette J.‐L.
Published: November 2004

The photostability of bisphenol‐A polycarbonate (PC) can be increased by depositing zinc oxide (ZnO) coatings onto PC films by radiofrequency (rf) magnetron sputtering using an ArO2 plasma. The photoprotective efficiency increases with the thickness of the ZnO layer and also depends on the sputtering parameters (rf power, total pressure, plasma composition), which control the properties of coatings. The increasing thickness of the deposits is correlated with variations of the density, grain size, and composition. PC samples with ZnO coatings were submitted to artificial accelerated ageing (λ > 300 nm) and the extent of the photodegradation was evaluated by infrared and UV–visible spectroscopies. All the deposition parameters were optimized as a function of the results obtained in photoageing and are described in this article. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 380–385, 2005
Using concepts in literature‐based discovery: Simulating Swanson's Raynaud–fish oil and migraine–magnesium discoveries
Authors: Weeber Marc , Klein Henny , de Jong‐van den Berg Lolkje T.W. , Vos Rein
Published: November 2004

Literature‐based discovery has resulted in new knowledge. In the biomedical context, Don R. Swanson has generated several literature‐based hypotheses that have been corroborated experimentally and clinically. In this paper, we propose a two‐step model of the discovery process in which hypotheses are generated and subsequently tested. We have implemented this model in a Natural Language Processing system that uses biomedical Unified Medical Language System (UMLS) concepts as its unit of analysis. We use the semantic information that is provided with these concepts as a powerful filter to successfully simulate Swanson's discoveries of connecting Raynaud's disease with fish oil and migraine with a magnesium deficiency.
Leaf Associated Microbial Activities in a Stream Affected by Acid Mine Drainage
Authors: Schlief Jeanette
Published: November 2004

Microbial activity was assessed on birch leaves and plastic strips during 140 days of exposure at three sites in an acidic stream of the Lusatian post‐mining landscape, Germany. The sites differed in their degrees of ochre deposition and acidification. The aim of the study was (1) to follow the microbial activities during leaf colonization, (2) to compare the effect of different environmental conditions on leaf associated microbial activities, and (3) to test the microbial availability of leaf litter in acidic mining waters. The activity peaked after 49 days and subsequently decreased gradually at all sites. A formation of iron plaques on leaf surfaces influenced associated microbial activity. It seemed that these plaques inhibit the microbial availability of leaf litter and serve as a microbial habitat by itself. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Carbohydrate metabolism in the central nervous system of the megalobulimus oblongus snail during anoxia exposure and post‐anoxia recovery
Authors: De Fraga Luciano S. , Da Silva Roselis S.M. , Achaval Matilde , Zancan Denise M.
Published: November 2004

The effects of anoxic exposure and the post‐anoxia aerobic recovery period on carbohydrate metabolism in the central nervous system (CNS) of the land snail Megalobulimus oblongus, an anoxia‐tolerant land gastropod, were studied. The snails were exposed to anoxia for periods of 1.5, 3, 6, 12, 18, or 24 hr. In order to study the post‐anoxia recovery phase, snails exposed to a 3‐hr period of anoxia were returned to aerobic conditions for 1.5, 3, 6, or 15 hr. Glycogen and glucose concentrations in the CNS, hemolymph glucose concentration, and glycogen phosphorylase (active form, GPa) activity in the CNS were analyzed. Anoxia does not significantly affect the concentration of CNS glucose but induces hyperglycemia and a reduction of CNS GPa activity. The glycogen concentration was decreased at 12 hr of anoxia; however, by 18 and 24 hr in anoxia, the glycogen content was not significantly different from basal control values. During the post‐anoxia period, the reduction in GPa activity and the increased hemolymph glucose concentration induced by anoxia returned to control values. These results suggest that the CNS of M. oblongus may use hemolymph glucose to fulfill the metabolic demands during anoxia. However, the hypothesis of tissue metabolic arrest cannot be excluded. J. Exp. Zool. 301A:968–978, 2004. © 2004 Wiley‐Liss, Inc.
Q‐ball imaging
Authors: Tuch David S.
Published: November 2004

Magnetic resonance diffusion tensor imaging (DTI) provides a powerful tool for mapping neural histoarchitecture in vivo. However, DTI can only resolve a single fiber orientation within each imaging voxel due to the constraints of the tensor model. For example, DTI cannot resolve fibers crossing, bending, or twisting within an individual voxel. Intravoxel fiber crossing can be resolved using q‐space diffusion imaging, but q‐space imaging requires large pulsed field gradients and time‐intensive sampling. It is also possible to resolve intravoxel fiber crossing using mixture model decomposition of the high angular resolution diffusion imaging (HARDI) signal, but mixture modeling requires a model of the underlying diffusion process.

Recently, it has been shown that the HARDI signal can be reconstructed model‐independently using a spherical tomographic inversion called the Funk–Radon transform, also known as the spherical Radon transform. The resulting imaging method, termed q‐ball imaging, can resolve multiple intravoxel fiber orientations and does not require any assumptions on the diffusion process such as Gaussianity or multi‐Gaussianity. The present paper reviews the theory of q‐ball imaging and describes a simple linear matrix formulation for the q‐ball reconstruction based on spherical radial basis function interpolation. Open aspects of the q‐ball reconstruction algorithm are discussed. Magn Reson Med 52:1358–1372, 2004. © 2004 Wiley‐Liss, Inc.
T2ρ‐weighted contrast in MR images of the human brain
Authors: Wheaton Andrew J. , Borthakur Arijitt , Corbo Matthew T. , Moonis Gul , Melhem Elias , Reddy Ravinder
Published: November 2004

In this work, the feasibility of using T2ρ weighting as an MR contrast mechanism is evaluated. Axial images of a human brain were acquired using a single‐slice spin‐lock T2ρ‐weighted pulse sequence and compared to analogous T2‐weighted images of the same slice. The contrast between white matter and gray matter in T2ρ‐weighted images was approximately 40% greater than that from T2‐weighted data. These preliminary data suggest that the novel contrast mechanism of T2ρ can be used to yield high‐contrast T2‐like images. Magn Reson Med 52:1223–1227, 2004. © 2004 Wiley‐Liss, Inc.
Evaluation of variable line‐shape models and prior information in automated 1H spectroscopic imaging analysis
Authors: Soher and Brian J. , Maudsley Andrew A.
Published: November 2004

Analysis of in vivo short TE 1H spectra is complicated by broad baseline signal contributions and resonance line‐shape distortions. Although the assumptions of ideal metabolite resonance line‐shapes and slowly varying baseline signals can be used to separate these signals, the presence of broad or asymmetric line‐shapes can invalidate this model. More complex line‐shape models are computationally expensive or difficult to constrain, particularly for the low signal‐to‐noise commonly found for in vivo MR spectroscopic imaging applications. In this study, two time‐domain models for fitting variable spectral line‐shapes are examined, one using B‐splines and another using summed sinusoids. The methods were verified using both phantom and human data, and Monte Carlo simulations were used to evaluate variations in calculated metabolite amplitudes due to interactions between the baseline and line‐shape estimations. Additional studies investigated the use of prior line‐shape information, obtained from either a water MRSI measurement or calculations from B0 maps, to determine parameter starting values or optimization constraints. Both line‐shape models showed the ability to fit the variety of line‐shapes present in both the phantom and human MRSI data, with similar or improved accuracy over a Gaussian line‐shape model; however, this improvement resulted in only minor improvement for the high‐SNR phantom data and moderate improvements in regions with asymmetry for the fitted in vivo metabolite images. The use of prior line‐shape information was of most benefit when applied toward setting optimization constraints but was of limited benefit when used to define initial starting values. Magn Reson Med 52:1246–1254, 2004. © 2004 Wiley‐Liss, Inc.
Magnetic exchange interactions in cyano‐bridged MoIII binuclear complexes: Broken‐symmetry and density functional theory calculations
Authors: Zhang Yi‐Quan , Luo Cheng‐Lin , Yu Zhi
Published: November 2004

Molecular magnetism in cyano‐bridged MoIII binuclear complexes [Mo2(CN)11]5− and [(Me3tacn)2Mo2(CN)5]+ (Me3tacnN, N′, N″‐trimethyl‐1,4,7‐triazacyclononane) has been calculated using Becke's three‐parameter exchange functional and the gradient‐corrected functional of Lee, Yang, and Parr (B3LYP), a hybrid density functional theory (DFT), combined with a modified broken symmetry (BS) approach and the post–Hartree‐Fock (post‐HF) method difference‐dedicated configuration interaction (DDCI). We find B3LYP combined with broken‐symmetry approach (DFT‐BS) give the similar J values to those calculated by DDCI. So we use B3LYP combined with BS approach to investigate the magnetism above two molecules. Through calculations, we find that the absolute J values decrease with the increase of r (the Mo(2)‐Cbrid and Mo(1)‐Nbrid distances) and are linearly related to the differences of the squared spin populations [(ρ − ρ)] on MoIII atoms between the highest‐spin (HS) state and the broken symmetry (BS) state. Moreover, the absolute J values are linearly related to the sum of the square of the difference in energy of the unpaired electrons (ξ) with a limited variation of the r distance. We conclude that ξ can be used to scale the degree of the antiferromagnetic coupling interactions. At the end of the paper, the spin density distributions and the mechanisms of magnetic coupling interactions are analyzed by us. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Mismatch base pairing of the mutagen 8‐oxoguanine and its derivatives with adenine: A theoretical search for possible antimutagenic agents
Authors: Singh A. K. , Mishra P. C.
Published: November 2004

Molecular geometries of 8‐oxoguanine (8OG), those of its substituted derivatives with the substitutions CH2, CF2, CO, CNH, O, and S in place of the N7H7 group, adenine (A), and the base pairs of 8OG and its substituted derivatives with adenine were optimized using the RHF/6‐31+G* and B3LYP/6‐31+G* methods in gas phase. All the molecules and their hydrogen‐bonded complexes were solvated in aqueous media employing the polarized continuum model (PCM) of the self‐consistent reaction field (SCRF) theory using the RHF/6‐31+G* and B3LYP/6‐31+G* methods. The optimized geometrical parameters of the 8OG‐A base pair at the RHF/6‐31+G* and B3LYP/6‐31+G* levels of theory agree satisfactorily with those of an oligonucleotide containing the base pair found from X‐ray crystallography. The pattern of hydrogen bonding in the CF2‐ and O‐substituted 8OG‐A base pair is of Watson–Crick type and that in the unsubstituted and CH2‐, CNH‐, and S‐substituted base pairs is of Hoogsteen type. In the CO‐substituted base pair, the hydrogen bonding pattern is of neither Watson–Crick nor Hoogsteen type. The CF2‐substitution appears to introduce steric hindrance for stacking of DNA bases. On the basis of these results, it appears that among all the substituted 8OG molecules considered here, the O‐substituted derivative may be useful as an antimutagenic drug. It is, however, subject to experimental verification. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Random mutagenesis of the gene encoding a viral ligand for multiple cell entry receptors to obtain viral mutants altered for receptor usage
Authors: Yoon Miri , Spear Patricia G.
Published: November 2004

Herpes simplex virus type 1 (HSV-1) can enter cells expressing any one of multiple entry receptors, including the herpesvirus entry mediator (HVEM), nectin-1, and sites in heparan sulfate generated by specific 3-
O
-sulfotransferases. The viral ligand for these receptors is glycoprotein D (gD). To define structural requirements for functional interactions of gD with its receptors and to obtain viral mutants altered for receptor usage, we generated a library of HSV-1 mutants with random mutations in the gD gene. Viral isolates selected on a monkey cell line (Vero) were screened for the loss of ability to infect cells expressing each of the HSV-1 receptors. The 10 HSV-1 mutants obtained had 12 mutations in gD, affecting 11 amino acids. All mutations reduced or abrogated viral entry through HVEM and 3-O-sulfated heparan sulfate, indicating that similar features of gD are critical for functional interactions with both these receptors. None of the mutations reduced viral entry through nectin-1, whereas a subset of the mutations conferred ability to use nectin-2 as an entry receptor. These and other results show that features of gD, including conformation of the N terminus, critical for functional interactions with HVEM/3-O-sulfated heparan sulfate, differ from those critical for interactions with nectin-1.
Functional Reprogramming of the Primary Immune Response by T Cell Receptor Antagonism
Authors: Haribhai Dipica , Edwards Brandon , Williams Mary L. , Williams Calvin B.
Published: November 2004

The T cell receptor must translate modest, quantitative differences in ligand binding kinetics into the qualitatively distinct signals used to determine cell fate. Here, we use mice that express an endogenous T cell receptor (TCR) antagonist and an adoptive transfer system to examine the influence of TCR signal quality on the development of effector function. We show that activation of antigen-specific T cells in the presence of an antagonist results in a functional reprogramming of the primary immune response, marked by altered T cell homing, a failure to develop effector function, and ultimately clonal elimination by apoptosis. Importantly, antagonism does not block cell division, implying that the signals promoting clonal expansion and effector differentiation are distinct.
Community resistance and change to nutrient enrichment and fish manipulation in a vegetated lake littoral
Authors: Hietala Jaana , Vakkilainen Kirsi , Kairesalo Timo
Published: November 2004

1. High biomass of macrophytes is considered important in the maintenance of a clear‐water state in shallow eutrophic lakes. Therefore, rehabilitation and protection of aquatic vegetation is crucial to the management of shallow lakes.

2. We conducted field mesocosm experiments in 1998 and 1999 to study community responses in the plant‐dominated littoral zone of a lake to nutrient enrichment at different fish densities. We aimed to find the threshold fish biomass for the different nutrient enrichment levels below which large herbivorous zooplankton escapes control by fish. The experiments took place in the littoral of Lake Vesijärvi in southern Finland and were part of a series of parallel studies carried out jointly at six sites across Europe.

3. In 1998, when macrophyte growth was poor, a clear‐water state with low phytoplankton biomass occurred only in unenriched mesocosms without fish or with low fish biomass (4 g fresh mass m−2). Both nutrient enrichment and high fish biomass (20 g fresh mass m−2) provoked a turbid water state with high planktonic and periphytic algal biomass. The zooplankton community was dominated by rotifers and failed to control the biomass of algae in nutrient enriched mesocosms. The littoral community thus had low buffer capacity against nutrient enrichment.

4. In 1999, macrophytes, especially free‐floating Lemna trisulca L., grew well and the zooplankton community was dominated by filter‐feeding cladocerans. The buffer capacity of the littoral community against nutrient enrichment was high; a clear‐water state with low phytoplankton biomass prevailed even under the highest nutrient enrichment. High grazing rates by cladocerans, together with reduced light penetration into the water caused by L. trisulca, were apparently the main mechanisms behind the low algal biomass.

5. Effects of fish manipulations were less pronounced than effects of nutrient enrichment. In 1999, clearance rates of cladocerans were similar in fish‐free and low‐fish treatments but decreased in the high‐fish treatment. This suggests that the threshold fish biomass was between the low‐ and high‐fish treatments. In 1998, such a threshold was found only between fish‐free and low‐fish treatments.

6. The pronounced difference in the observed responses to nutrient enrichment and fish additions in two successive years suggests that under similar nutrient conditions and fish feeding pressure either clear or turbid water may result depending on the initial community structure and on weather.
Mesocosm experiments on nutrient and fish effects on shallow lake food webs in a Mediterranean climate
Authors: Romo Susana , Miracle María R. , Villena María‐José , Rueda Juan , Ferriol Carmen , Vicente Eduardo
Published: November 2004

1. Nutrient and fish manipulations in mesocosms were carried out on food‐web interactions in a Mediterranean shallow lake in south‐east Spain. Nutrients controlled biomass of phytoplankton and periphyton, while zooplankton, regulated by planktivorous fish, influenced the relative percentages of the dominant phytoplankton species.

2. Phytoplankton species diversity decreased with increasing nutrient concentration and planktivorous fish density. Cyanobacteria grew well in both turbid and clear‐water states.

3. Planktivorous fish increased concentrations of soluble reactive phosphorus (SRP). Larger zooplankters (mostly Ceriodaphnia and copepods) were significantly reduced when fish were present, whereas rotifers increased, after fish removal of cyclopoid predators and other filter feeders (cladocerans, nauplii). The greatest biomass and diversity of zooplankton was found at intermediate nutrient levels, in mesocosms without fish and in the presence of macrophytes.

4. Water level decrease improved underwater light conditions and favoured macrophyte persistence. Submerged macrophytes (Chara spp.) outcompeted algae up to an experimental nutrient loading equivalent to added concentrations of 0.06 mg L−1 PO4‐P and 0.6 mg L−1 NO3‐N, above which an exponential increase in periphyton biomass and algal turbidity caused characean biomass to decline.

5. Declining water levels during summer favoured plant‐associated rotifer species and chroococcal cyanobacteria. High densities of chroococcal cyanobacteria were related to intermediate nutrient enrichment and the presence of small zooplankton taxa, while filamentous cyanobacteria were relatively more abundant in fishless mesocosms, in which Crustacea were more abundant, and favoured by dim underwater light.

6. Benthic macroinvertebrates increased significantly at intermediate nutrient levels but there was no relationship with planktivorous fish density.

7. The thresholds of nutrient loading and in‐lake P required to avoid a turbid state and maintain submerged macrophytes were lower than those reported from temperate shallow lakes. Mediterranean shallow lakes may remain turbid with little control of zooplankton on algal biomass, as observed in tropical and subtropical lakes. Nutrient loading control and macrophyte conservation appear to be especially important in these systems to maintain high water quality.
Roe deer Capreolus capreolus behaviour affects density estimates from distance sampling surveys
Authors: WARD ALASTAIR I. , WHITE PIRAN C. L. , CRITCHLEY CHARLES H.
Published: November 2004

1. Roe deer Capreolus capreolus were surveyed at night along tracks and roads in plantation forests in North Yorkshire, UK. Distance sampling was used to estimate their density. This method has been proposed for monitoring deer populations in state‐owned forests throughout the UK.

2. Most deer were stationary on detection and the vast majority did not change their behaviour during observation. Few deer were observed on the transects, suggesting that they were avoiding tracks and roads at night as opposed to moving in response to the observer.

3. This has implications for data analysis and hence the results of surveys. Left‐truncation or grouping of data close to the transect line to cope with road avoidance decreased the precision of the population estimate and may have impacted upon its accuracy.

4. Use of roads and tracks in forests is the only realistic option for transect surveys of deer at night but the influence of these features on deer distribution and hence density estimates must be taken into consideration when conducting such surveys.
Attention to Detail: The Conservative Policy Agenda
Authors: DOREY PETER
Published: November 2004

Since 2001 (if not since 1997) the Conservative party has struggled to develop a coherent set of policies with which to provide a credible alternative to the Blair government. A second successive crushing election defeat fuelled the ongoing debates in the Conservative party, between those who were convinced of the need to steer towards the centre ground, thereby reviving the Conservative's 'one nation' tradition, and those who wanted to place clear blue water between themselves and New Labour, and thus adhere to Thatcherite radicalism. The Conservatives have therefore appeared to struggle in developing clear, alternative policies on such issues as 'tax‐and‐spend' and public service reform and delivery. They have, however, inched hesitatingly towards a more socially liberal stance on various issues. A major problem for the Conservatives has been that the Blair governments have actually continued with, or consolidated, many policies inherited from the Conservatives in 1997, thereby making it even more difficult for the Conservatives to articulate their own distinct policy agenda. This is likely to contribute towards a third heavy defeat for the Conservative party in the next general election.
A Turbulence Model for Pulsatile Arterial Flows
Authors: Younis B. A. , Berger S. A.
Published: November 2004

Difficulties in predicting the behavior of some high Reynolds number flows in the circulatory system stem in part from the severe requirements placed on the turbulence model chosen to close the time-averaged equations of fluid motion. In particular, the successful turbulence model is required to (a) correctly capture the “nonequilibrium” effects wrought by the interactions of the organized mean-flow unsteadiness with the random turbulence, (b) correctly reproduce the effects of the laminar-turbulent transitional behavior that occurs at various phases of the cardiac cycle, and (c) yield good predictions of the near-wall flow behavior in conditions where the universal logarithmic law of the wall is known to be not valid. These requirements are not immediately met by standard models of turbulence that have been developed largely with reference to data from steady, fully turbulent flows in approximate local equilibrium. The purpose of this paper is to report on the development of a turbulence model suited for use in arterial flows. The model is of the two-equation eddy-viscosity variety with dependent variables that are zero-valued at a solid wall and vary linearly with distance from it. The effects of transition are introduced by coupling this model to the local value of the intermittency and obtaining the latter from the solution of a modeled transport equation. Comparisons with measurements obtained in oscillatory transitional flows in circular tubes show that the model produces substantial improvements over existing closures. Further pulsatile-flow predictions, driven by a mean-flow wave form obtained in a diseased human carotid artery, indicate that the intermittency-modified model yields much reduced levels of wall shear stress compared to the original, unmodified model. This result, which is attributed to the rapid growth in the thickness of the viscous sublayer arising from the severe acceleration of systole, argues in favor of the use of the model for the prediction of arterial flows.
Steady Propagation of a Liquid Plug in a Two-Dimensional Channel
Authors: Fujioka Hideki , Grotberg James B.
Published: November 2004

In this study, we investigate the steady propagation of a liquid plug within a two-dimensional channel lined by a uniform, thin liquid film. The Navier-Stokes equations with free-surface boundary conditions are solved using the finite volume numerical scheme. We examine the effect of varying plug propagation speed and plug length in both the Stokes flow limit and for finite Reynolds number (Re). For a fixed plug length, the trailing film thickness increases with plug propagation speed. If the plug length is greater than the channel width, the trailing film thickness agrees with previous theories for semi-infinite bubble propagation. As the plug length decreases below the channel width, the trailing film thickness decreases, and for finite Re there is significant interaction between the leading and trailing menisci and their local flow effects. A recirculation flow forms inside the plug core and is skewed towards the rear meniscus as Re increases. The recirculation velocity between both tips decreases with the plug length. The macroscopic pressure gradient, which is the pressure drop between the leading and trailing gas phases divided by the plug length, is a function of U and U2, where U is the plug propagation speed, when the fluid property and the channel geometry are fixed. The U2 term becomes dominant at small values of the plug length. A capillary wave develops at the front meniscus, with an amplitude that increases with Re, and this causes large local changes in wall shear stresses and pressures.
An Electrodiffusion-Filtration Model for Effects of Endothelial Surface Glycocalyx on Microvessel Permeability to Macromolecules
Authors: Chen Bin , Fu Bingmei M.
Published: November 2004

Endothelial surface glycocalyx plays an important role in the regulation of microvessel permeability by possibly changing its charge and configuration. To investigate the mechanisms by which surface properties of the endothelial cells control the changes in microvessel permeability, we extended the electrodiffusion model developed by Fu et al. [Am. J. Physiol. 284, H1240–1250 (2003)], which is for the interendothelial cleft with a negatively charged surface glycocalyx layer, to include the filtration due to hydrostatic and oncotic pressures across the microvessel wall as well as the electrical potential across the glycocalyx layer. On the basis of the hypotheses proposed by Curry [Microcirculation 1(1): 11–26 (1994)], the predictions from this electrodiffusion-filtration model provide a good agreement with experimental data for permeability of negatively charged α-lactalbumin summarized in Curry [Microcirculation 1(1), 11–26 (1994)] under various conditions. In addition, we applied this new model to describe the transport of negatively charged macromolecules, bovine serum albumin (BSA), across venular microvessels in frog mesentery. According to the model, the convective component of the albumin transport is greatly diminished by the presence of a negatively charged glycocalyx under both normal and increased permeability conditions.
Gamma Interferon Does Not Enhance Clearance ofPseudomonas aeruginosabut Does Amplify a Proinflammatory Response in a Murine Model of Postseptic Immunosuppression
Authors: Murphey E. D. , Herndon David N. , Sherwood Edward R.
Published: November 2004

Patients that have suffered a major injury may sustain a period of immunocompromise and altered Th1/Th2 cytokine balance that can predispose them to opportunistic infections.Pseudomonas aeruginosais frequently a causative organism for nosocomial infections in critically ill patients and is associated with high mortality. We previously mimicked this clinical scenario by challenging mice withP. aeruginosa5 days after a cecal ligation and puncture (CLP) procedure. Mice that were subjected to CLP had reduced ability to clear bacteria, significantly lower gamma interferon (IFN-γ) concentrations in plasma, and significantly elevated levels of interleukin 10 (IL-10) in plasma in response to thePseudomonaschallenge compared to uninjured control mice. We investigated the significance of the alteration in IFN-γ by administering recombinant IFN-γ to post-CLP mice at the time ofPseudomonaschallenge and by challenging IFN-γ knockout (IFN-γ KO) mice withPseudomonas. Administration of IFN-γ to post-CLP mice attenuated IL-10 secretion and enhanced IL-12 secretion but did not improve bacterial clearance or survival afterPseudomonaschallenge. Furthermore, IFN-γ KO mice had significantly higher plasma IL-10 concentrations but did not exhibit impaired bacterial clearance or increased mortality followingPseudomonaschallenge. These data indicate that systemic administration of IFN-γ effectively reverses alterations in immune function that are commonly associated with immunosuppression in critically injured mice but does not improve bacterial clearance or survival followingPseudomonaschallenge. Further, endogenous IFN-γ does not appear to contribute significantly to early clearance ofPseudomonasbacteremia, nor does it affect the mortality rate after a lethalPseudomonaschallenge.
Severity of Human African Trypanosomiasis in East Africa Is Associated with Geographic Location, Parasite Genotype, and Host Inflammatory Cytokine Response Profile
Authors: MacLean Lorna , Chisi John E. , Odiit Martin , Gibson Wendy C. , Ferris Vanessa , Picozzi Kim , Sternberg Jeremy M.
Published: November 2004

The mechanisms underlying virulence in human African trypanosomiasis are poorly understood, although studies with experimental mice suggest that unregulated host inflammatory responses are associated with disease severity. We identified two trypanosomiasis foci with dramatically different disease virulence profiles. In Uganda, infections followed an acute profile with rapid progression to the late stage (meningoencephalitic infection) in the majority of patients (86.8%). In contrast, infections in Malawi were of a chronic nature, in which few patients progressed to the late stage (7.1%), despite infections of several months' duration. All infections were confirmed to beTrypanosoma brucei rhodesienseby testing for the presence of the serum resistance-associated (SRA) gene, but trypanosomes isolated from patients in Uganda or Malawi were distinguished by anSRAgene polymorphism. The two disease profiles were associated with markedly different levels of tumor necrosis factor alpha (TNF-α) and transforming growth factor β (TGF-β) in plasma. In Uganda but not Malawi early-stage TNF-α was elevated, while in Malawi but not Uganda early-stage TGF-β was elevated. Thus, rapid disease progression in Uganda is associated with TNF-α-mediated inflammatory pathology, whereas in the milder disease observed in Malawi this may be ameliorated by counterinflammatory cytokines. These differing host responses may result either from differing virulence phenotypes of northern and southern trypanosomes or from immune response polymorphisms in the different host populations.
Differential Regulation of Inflammatory Cytokine Secretion by Human Dendritic Cells upon
Chlamydia trachomatis
Infection
Authors: Gervassi Ana , Alderson Mark R. , Suchland Robert , Maisonneuve Jean François , Grabstein Kenneth H. , Probst Peter
Published: November 2004

Chlamydia trachomatis
is an obligate intracellular gram-negative bacterium responsible for a wide spectrum of diseases in humans. Both genital and ocular
C. trachomatis
infections are associated with tissue inflammation and pathology. Dendritic cells (DC) play an important role in both innate and adaptive immune responses to microbial pathogens and are a source of inflammatory cytokines. To determine the potential contribution of DC to the inflammatory process, human DC were infected with
C. trachomatis
serovar E or L2. Both
C. trachomatis
serovars were found to infect and replicate in DC. Upon infection, DC up-regulated the expression of costimulatory (B7-1) and cell adhesion (ICAM-1) molecules. Furthermore, chlamydial infection induced the secretion of interleukin-1β (IL-1β), IL-6, IL-8, IL-12p70, IL-18, and tumor necrosis factor alpha (TNF-α). The mechanisms involved in
Chlamydia
-induced IL-1β and IL-18 secretion differed from those of the other cytokines.
Chlamydia
-induced IL-1β and IL-18 secretion required infection with viable bacteria and was associated with the
Chlamydia
-induced activation of caspase-1 in infected host cells. In contrast, TNF-α and IL-6 secretion did not require that the
Chlamydia
be viable, suggesting that there are at least two mechanisms involved in the
Chlamydia
-induced cytokine secretion in DC. Interestingly, an antibody to Toll-like receptor 4 inhibited
Chlamydia
-induced IL-1β, IL-6, and TNF-α secretion. The data herein demonstrate that DC can be infected by human
C. trachomatis
serovars and that chlamydial components regulate the secretion of various cytokines in DC. Collectively, these data suggest that DC play a role in the inflammatory processes caused by chlamydial infections.
Antifungal Immune Reactivity in Nasal Polyposis
Authors: Pitzurra Lucia , Bellocchio Silvia , Nocentini Angela , Bonifazi Pierluigi , Scardazza Raffaele , Gallucci Luigi , Stracci Fabrizio , Simoncelli Costantino , Bistoni Francesco , Romani Luigina
Published: November 2004

As a fungal etiology has been proposed to underlie severe nasal polyposis, the present study was undertaken to assess local antifungal immune reactivity in nasal polyposis. For this purpose, microbial colonization, along with the pattern of T helper 1 (Th1)/Th2 cytokine production and Toll-like receptor (TLR) expression, was evaluated in patients with nasal symptoms and with and without polyposis and in healthy subjects. The results show that Th2 reactivity was a common finding for patients with nasal polyposis regardless of the presence of microbes. The production of interleukin-10 was elevated in patients with bacterial and, particularly, fungal colonization, while both TLR2 expression and TLR4 expression were locally impaired in microbe-colonized patients. Eosinophils and neutrophils, highly recruited in nasal polyposis, were found to exert potent antifungal effector activities toward conidia and hyphae of the fungus and to be positively regulated by TLR2 or TLR4 stimulation. Therefore, a local imbalance between activating and deactivating signals to effector cells may likely contribute to fungal pathogenicity and the expression of local immune reactivity in nasal polyposis.
Age structure, growth, and demographic parameters in breeding-age female subantarctic fur seals,Arctocephalus tropicalis
Authors: Dabin Willy , Beauplet Gwénaël , Crespo Enrique A , Guinet Christophe
Published: November 2004

Age distribution was estimated for 108 breeding-age female subantarctic fur seals, Arctocephalus tropicalis (Gray, 1872), sampled during the 1999–2000 breeding season on Amsterdam Island, southern Indian Ocean. The growth features were described and demographic parameters assessed from transversal life tables constructed for this female population. The breeding females had a longer mean body length than was observed for other breeding populations of the same species. These females also showed a later start to reproduction (6 years old), a lower overall age-specific reproductive rate (R6–16 = 48.0%), and a lower survival in older age classes (>13 years). Females reproduced up to a maximum age of 16 years, with none older than 19 years observed in the colony, suggesting an apparent senescence in the population. This consequently reduced the theoretical reproductive period of the females, which has led to a lower number of reproductive outputs per individual (i.e., 3.65 weaned pups per female throughout its reproductive life). Although such differences between islands may be related to genotypic traits, these results are consistent with low food availability and suggest that density-dependent regulatory processes operate on the Amsterdam Island population.
Spacing behavior and morphology predict promiscuous mating strategies in the rock-dwelling snow vole, Chionomys nivalis
Authors: Luque-Larena Juan José , López Pilar , Gosálbez Joaquim
Published: November 2004

Adaptive models predict that variation in the spacing of microtines during reproductive periods may reflect mating strategies linked to differences in habitat characteristics. Using spatial and morphological analyses, we aimed to assess the mating system adopted by a population of rock-dwelling snow voles, Chionomys nivalis (Martins, 1842), and its functional significance within high-mountain environments. Spacing data coincided with a pattern generally associated with promiscuous mating: males had largely overlapping home ranges, whereas female home ranges showed a very reduced or absent degree of overlap. In addition, ranges overlapped considerably between sexes. Males had significantly greater body mass than females, and the magnitude of this difference resembled more a promiscuous than a polygamous or monogamous species. Also, relative testis size of males was in the range reported for promiscuous voles. Our results fit the predictions made by food abundance and distribution optimality models, suggesting that mating strategies might be related to the habitat occupied by C. nivalis. In alpine rocky formations, vegetation is sparse and patchily distributed, and competing females could benefit from defending an exclusive territory. In turn, males might be unable to monopolize widely spaced females by defending exclusive territories, which may result in extensive overlap between their spatial ranges.
SCHEDULING FILE TRANSFERS UNDER PORT AND CHANNEL CONSTRAINTS
Authors: NAKANO SHIN-ICHI , NISHIZEKI TAKAO
Published: November 2004

The file transfer scheduling problem was introduced and studied by Coffman, Garey, Johnson and LaPaugh. The problem is to schedule transfers of a large collection of files between various nodes of a network under port constraint so as to minimize the overall finishing time. This paper extends their model to include communication channel constraint in addition to port constraint. We formulate the problem with both port and channel constraints as a new type of edge-coloring of multigraphs, called an fg-edge-coloring, and give an efficient approximation algorithm with absolute worst-case ratio 3/2.
A NEW CHARACTERIZATION OF UNBREAKABLE GRAPHS
Authors: OLARIU STEPHAN , STEWART IAIN A.
Published: November 2004

A nonempty set C of vertices of a graph G is a star-cutset if G\C is disconnected and some vertex in C is adjacent to all the remaining vertices in C. A graph G is unbreakable if neither G nor its complement Ḡ contains a star-cutset. In this note we present a new characterization of unbreakable graphs.