bluuebunny/crossref_metadata_2025 huggingface dataset:
Process Simulation for Molten Carbonate Fuel Cells
Authors: Fermeglia M. , Cudicio A. , DeSimon G. , Longo G. , Pricl S.
Published: November 2004

In the framework of electricity production from molten carbonate fuel cells (MCFC), this work presents the results obtained from steady state process simulation, coupled with a detailed dynamic model for the cell. The derivation of the model is briefly outlined, and detailed results of the simulation are reported. Macroscopic state variables of the overall system process are investigated by means of sensitivity analysis, yielding clear directions for process improvement and optimisation. The detailed steady state and dynamic simulation of the MCFC for a bi‐dimensional cross flow configuration showed the importance of the state variable distribution in the cell. Both models were based on data from real plants, and the simulation conditions were selected according to real operating conditions. The process studied was a 500 kW MCFC power system based on Ansaldo fuel cell (AFC) technology. The steady state simulation revealed the main interactions among the different devices involved in the process, and the subsequent sensitivity analysis showed that there is room for improvement in electrical efficiency by increasing: i) the steam to methane ratio, ii) the pressure, and iii) the air feed ratio. The dynamic simulation yielded the quantitative response of the system to several, different, perturbations and proved to be a valid tool for determining temperature, current, and voltage profiles as a function of time, within the fuel cells.
Influence of Summer Drought on Spatial Patterns of Resource Availability and Detritus Processing in Mediterranean Stream Sub‐Basins (Sardinia, Italy)
Authors: Pinna Maurizio , Fonnesu Alessio , Sangiorgio Franca , Basset Alberto
Published: November 2004

We studied the variation patterns of Phragmites australis detritus decomposition and derived patterns of field resource availability in three Mediterranean‐type sub‐basins exposed to varying degrees to summer drought events. The study was carried out during spring‐summer 1998 and fall‐winter 1998–1999, in 1st to 4th order streams. Detritus processing and macroinvertebrate body‐condition were measured. Decomposition rates were significantly higher in spring‐summer than in fall‐winter, in relatively unper turbed than in perturbed sub‐basins, and in high‐order than low‐order streams. The influence of disturbance decreased with increasing stream order, suggesting that higher order streams have greater resilience to drought events than lower order streams. The body condition of macroinvertebrates suggested patterns of field resource availability spatially covariant with those of detritus decay and ecosystem resilience. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Endocrine response to fasting in the overwintering captive raccoon dog (Nyctereutes procyonoides)
Authors: nieminen Petteri , Saarela Seppo , Pyykönen Teija , Asikainen Juha , Mononen Jaakko , Mustonen Anne‐Mari
Published: November 2004

The raccoon dog (Nyctereutes procyonoides) is an omnivorous canid utilizing the passive wintering strategy in the boreal climate. Farmed raccoon dogs (n=12) were randomly assigned into two study groups on 26 November 2003. Between 3 December 2003 and 27 January 2004, half of the animals were fasted for 8 weeks and plasma weight‐regulatory hormone concentrations determined on 26 November and 30 December 2003 and on 27 January 2004. The plasma peptide YY, ghrelin, and growth hormone (GH) concentrations increased due to food deprivation, while the T4 and Acrp30 concentrations decreased. Furthermore, the plasma GH concentrations were higher in the fasted raccoon dogs than in the fed animals, which had higher plasma insulin, glucagon, and T4 concentrations. However, fasting had no effect on the plasma leptin concentrations. The results confirm previous findings with unchanged leptin levels in fasting carnivores. Increased GH levels probably contribute to increased lipolysis and mobilization of fat stores. Ghrelin can also enhance lipolysis by increasing the GH levels. The decreased levels of T4 may reduce the metabolic rate. The plasma dopamine concentrations decreased due to fasting unlike observed previously in rats. Together with the unaffected adrenaline, noradrenaline, and cortisol concentrations, this suggests that food deprivation in winter does not cause stress to the raccoon dog but is an integral part of its natural life history. J. Exp. Zool. 301A:919–929, 2004. © 2004 Wiley‐Liss, Inc.
Continuous-wave broadband fiber optical parametric amplifier based
on 150 m of HNLF pumped with fiber laser
Authors: Solodyankin M A , Guryanov A N , Kazantseva N A , Khopin V F , Bubnov M M , Likhachev M E , Dianov E M
Published: November 2004

Development of broadband fiber optical parametric
amplifier based on highly nonlinear fiber pumped with tunable
continuous wave fiber laser is reported. Creation of highly
nonlinear fiber with optimized parameters is presented. Over 50 nm
bandwidth continuous wave optical parametric gain in highly
nonlinear fiber has been measured.
In vivo visualization of Alzheimer's amyloid plaques by magnetic resonance imaging in transgenic mice without a contrast agent
Authors: Jack Clifford R. , Garwood Michael , Wengenack Thomas M. , Borowski Bret , Curran Geoffrey L. , Lin Joseph , Adriany Gregor , Gröhn Olli H. J. , Grimm Roger , Poduslo Joseph F.
Published: November 2004

One of the cardinal pathologic features of Alzheimer's disease (AD) is the formation of senile, or amyloid, plaques. Transgenic mice have been developed that express one or more of the genes responsible for familial AD in humans. Doubly transgenic mice develop “human‐like” plaques, providing a mechanism to study amyloid plaque biology in a controlled manner. Imaging of labeled plaques has been accomplished with other modalities, but only MRI has sufficient spatial and contrast resolution to visualize individual plaques noninvasively. Methods to optimize visualization of plaques in vivo in transgenic mice at 9.4 T using a spin echo sequence based on adiabatic pulses are described. Preliminary results indicate that a spin echo acquisition more accurately reflects plaque size, while a T2* weighted gradient echo sequence reflects plaque iron content, not plaque size. In vivo MRI–ex vivo MRI–in vitro histologic correlations are provided. Histologically verified plaques as small as 50 μm in diameter were visualized in living animals. To our knowledge this work represents the first demonstration of noninvasive in vivo visualization of individual AD plaques without the use of a contrast agent. Magn Reson Med 52:1263–1271, 2004. © 2004 Wiley‐Liss, Inc.
Measurement and correction of respiration‐induced B0 variations in breast 1H MRS at 4 Tesla
Authors: Bolan Patrick J. , Henry Pierre‐Gilles , Baker Eva H. , Meisamy Sina , Garwood Michael
Published: November 2004

Respiratory motion is well known to cause artifacts in magnetic resonance spectroscopy (MRS). In MRS of the breast, the dominant artifact is not due to motion of the breast itself, but rather it is produced by B0 field distortions associated with respiratory motion of tissues in the chest and abdomen. This susceptibility artifact has been reported to occur in the brain, but it is more apparent in the breast due to the anatomic proximity of the lungs. In the breast, these B0 distortions cause shot‐to‐shot frequency shifts, which vary an average of 24 Hz during a typical 1H MRS scan at 4 T. This variation can be corrected retrospectively by frequency shifting individual spectra prior to averaging. If not corrected, these shifts reduce spectral resolution and increase peak fitting errors. This work demonstrates the artifact, describes a method for correcting it, and evaluates its impact on quantitative spectroscopy. When the artifact is not corrected, quantification errors increase by an average of 28%, which dramatically impacts the ability to measure metabolite resonances at low signal‐to‐noise ratios. Magn Reson Med 52:1239–1245, 2004. © 2004 Wiley‐Liss, Inc.
Experimental application of thermosensitive paramagnetic liposomes for monitoring magnetic resonance imaging guided thermal ablation
Authors: Frich Lars , Bjørnerud Atle , Fossheim Sigrid , Tillung Terje , Gladhaug Ivar
Published: November 2004

The use of a liposomal paramagnetic agent with a T1‐relaxivity that increases markedly at temperatures above the phase transition temperature (Tm) of the liposomal membrane was evaluated during magnetic resonance imaging (MRI) guided hyperthermia ablation. A neodymium‐yttrium aluminum garnet (Nd‐YAG) laser unit and a radiofrequency ablation system were used for tissue ablation in eight rabbit livers in vivo. One ablation was made in each animal prior to administration of the liposomal agent. Liposomes with a Tm of 57°C containing gadodiamide (GdDTPA‐BMA) were injected iv, and two additional ablations were performed. T1‐weighted scans were performed in heated tissue, after tissue temperature had normalized, and 15–20 min after normalization of tissue temperature. Increase in signal intensity (ΔSI) for ablations prior to injection of the agent was 13.0% (SD = 5.7) for the laser group and 9.1% (SD = 7.9) for the radiofrequency group. Signal intensity after administration of the agent unrelated to heating was not statistically significant (ΔSI = 1.4%, P = 0.35). For ablations made after injection of the agent, a significant increase was found in the laser (ΔSI = 34.5%, SD = 11.9) and radiofrequency group (ΔSI = 21.6%, SD = 22.7). The persistent signal enhancement found in areas exposed to a temperature above the threshold temperature above Tm allows thermal monitoring of MRI guided thermal ablation. Magn Reson Med 52:1302–1309, 2004. © 2004 Wiley‐Liss, Inc.
Simultaneous MRI acquisition of blood volume, blood flow, and blood oxygenation information during brain activation
Authors: Yang Yihong , Gu Hong , Stein Elliot A.
Published: November 2004

Simultaneous acquisition of complementary functional hemodynamic indices reflecting different aspects of brain activity would be a valuable tool for functional brain‐imaging studies offering enhanced detection power and improved data interpretation. As such, a new MRI technique is presented that is able to achieve concurrent acquisition of three hemodynamic images based primarily on the changes of cerebral blood volume, blood flow, and blood oxygenation, respectively, associated with brain activation. Specifically, an inversion recovery pulse sequence has been designed to measure VASO (vascular space occupancy), ASL (arterial spin labeling) perfusion, and BOLD (blood‐oxygenation‐level‐dependent) signals in a single scan. The MR signal characteristics in this sequence were analyzed, and image parameters were optimized for the simultaneous acquisition of these functional images. The feasibility and efficacy of the new technique were assessed by brain activation experiments with visual stimulation paradigms. Experiments on healthy volunteers showed that this technique provided efficient image acquisition, and thus higher contrast‐to‐noise ratio per unit time, compared with conventional techniques collecting these functional images separately. In addition, it was demonstrated that the proposed technique was able to be utilized in event‐related functional MRI experiments, with potential advantages of obtaining accurate transient information of the activation‐induced hemodynamic responses. Magn Reson Med 52:1407–1417, 2004. Published 2004 Wiley‐Liss, Inc.
A generalized affine gap model significantly improves protein sequence alignment accuracy
Authors: Zachariah Marcus A. , Crooks Gavin E. , Holbrook Stephen R. , Brenner Steven E.
Published: November 2004

Sequence alignment underpins common tasks in molecular biology, including genome annotation, molecular phylogenetics, and homology modeling. Fundamental to sequence alignment is the placement of gaps, which represent character insertions or deletions. We assessed the ability of a generalized affine gap cost model to reliably detect remote protein homology and to produce high‐quality alignments. Generalized affine gap alignment with optimal gap parameters performed as well as the traditional affine gap model in remote homology detection. Evaluation of alignment quality showed that the generalized affine model aligns fewer residue pairs than the traditional affine model but achieves significantly higher per‐residue accuracy. We conclude that generalized affine gap costs should be used when alignment accuracy carries more importance than aligned sequence length. Proteins 2005. © 2004 Wiley‐Liss, Inc.
Role of the electronic properties of azurin active site in the electron‐transfer process
Authors: Corni Stefano , De Rienzo Francesca , Di Felice Rosa , Molinari Elisa
Published: November 2004

Electron transfer proteins, such as azurin (a blue copper protein), are promising candidates for the implementation of biomolecular nanoelectronic devices. To understand the details of electron transfer in redox active azurin molecules, we performed plane‐wave pseudo‐potential density functional theory (DFT) calculations of the protein active site in the two possible oxidation states Cu(I) and Cu(II). The ab initio results are used to discuss how the electronic spectrum and wavefunctions may mediate the shuttling of electrons through the copper ion. We find that the Cu‐ligand hybridization is very similar in the two charge states of the metal center, but the energy spectrum changes substantially. This result might indicate important effects of electronic correlations in the redox activity and consequent electron transfer through the Cu site. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
A new genus and species of alvinocaridid shrimp (Crustacea: Decapoda: Caridea) from hydrothermal vents on the North Fiji and Lau Basins, south-western Pacific
Authors: Komai Tomoyuki , Segonzac Michel
Published: November 2004

Nautilocaris saintlaurentae gen. nov., sp. nov., is described and illustrated from hydrothermal vents in the North Fiji Basin and Lau Basin in the south-western Pacific. This new taxon is assigned to the Alvinocarididae. It has a well-developed, dorsally dentate rostrum, carapace with pterygostomian spine present, eye broadly fused mesially, epipod–setobranch complex present above pereopods, and appendix internae on second to fourth pleopods greatly reduced. This combination of characters places it in an intermediate position between a group of species in the genus Alvinocaris with well developed, dorsally dentate rostrum, carapace with pterygostomian spine present, eyes narrowly fused mesially, epipod–setobranch complex absent and well-developed appendices internae on second to fourth pleopods, and Mirocaris fortunata with rostrum unarmed, carapace with rounded pterygostomian angle, eye broadly fused mesially, epipod–setobranch complex present above pereopods and appendices internae on second to fourth pleopods greatly reduced. The habitat of the new species is briefly described.
The nursery function of sandy beaches in a Brazilian tropical bay for 0-group anchovies (Teleostei: Engraulidae): diel, seasonal and spatial patterns
Authors: de Araújo Silva Márcio , Araújo Francisco Gerson , de Azevedo Márcia Cristina Costa , de Sousa Santos Joaquim Neto
Published: November 2004

The role of sandy beaches as nursery areas for 0-group anchovies (Teleostei: Engraulidae) was investigated in a tropical bay, south-eastern Brazil. Spatial and temporal (diel and seasonal) changes in fish abundance and environmental influences at two beaches were assessed, one located in the outer zone, and the other in the inner zone of Sepetiba Bay. The two sites were sampled quarterly at the same time (0800, 1100, 1400, 1700, 2000, 2300, 0200 and 0500 hours) over a 24 h cycle by beach seine with three replicates, between winter 1998 and autumn 1999. Environmental variables of water temperature, salinity, and transparency (as % depth) were taken at each fish-sampling occasion. Five species in three genera (Anchoa tricolor, A. januaria, A. lyolepis, Cetengraulis edentulus, and Lycengraulis grossidens) were identified. Anchoa tricolor and A. januaria were the most abundant species and indications of spatial separation were detected, with A. tricolor being more abundant in the outer bay (higher salinity and lower temperature), while A. januaria, in the inner bay (lower salinity and higher temperature). Overall, young-of-the-year Engraulidae peaked during the day, perhaps an adaptation to avoid competition with other abundant species which peak at night. Maximum densities of anchovies due to 0-group influxes were found in spring and paucity in summer. Spatial segregation to optimize resource uses and daily habits adapted to take advantage of the rich planktonic bay waters seems to be the strategy developed by these closely related species to use the area during early life cycle. Their high abundances suggest the suitability of the sandy beaches as nursery areas.
Biology of the marine tucuxi dolphin (Sotalia fluviatilis) in south-eastern Brazil
Authors: Di Beneditto Ana Paula Madeira , Ramos Renata Maria Arruda
Published: November 2004

Age, growth and reproductive parameters related to the marine tucuxi are presented, as well as feeding habits and parasitism. The specimens' age ranged from zero (newborn) to 21 years for males and 0·5 to 30 years for females. In relation to the body dimension, length distributions were bell-shaped for both sexes with male marine tucuxi ranging from 86·0 to 200·0 cm in length and females from 117·5 to 198·0 cm. The body length of new-born and calves varied between 86·0 to 117·5 cm and the postnatal growth curve an asymptotic reached length of 191·0 cm. According to the relationship between age, body length and reproductive characteristics, male and female specimens were considered sexually mature when [ges ]6 years and body length [ges ]180·0 cm and [ges ]6 years and body length [ges ]160·0 cm, respectively. Males and females up to six years old represented around 80% of the captures, indicating a bias towards juveniles and individuals that have yet to reach sexual maturity. The youngest specimen with solid contents in the stomach was 119·0 cm in length and seven months old. The marine tucuxi feeds on neritic prey, preferentially on the teleost fishes Trichiurus lepturus and Porichthys porossisimus, and on the cephalopods Loligo sanpaulensis and L. plei. Back calculation of prey lengths indicated that fish ranged from 1·2 to 106·9 cm and cephalopods from 3·4 to 22·2 cm. The barnacle Xenobalanus globicipitis was recorded attaching to the caudal fin and the helminths Braunina cordiformis, Anisakis typica, Halocercus brasiliensis and Nasitrema sp. were found in the internal organs.
Phosphate and arsenate interactions in the rhizosphere of canola (Brassica napus)
Authors: Quaghebeur Mieke , Rengel Zed
Published: November 2004

Arsenate [As(V)] and phosphate [P(V)] compete for the same uptake systems in plant roots. For this reason, P(V) is often added to As-contaminated soils to reduce As(V) uptake and alleviate As toxicity. However, the addition of P(V) can result in an increase in As concentrations in plant tissues, which is often attributed to an increase in As(V) availability, although direct evidence for this explanation is lacking. Rhizosphere and batch desorption experiments were conducted to investigate (i) the effect of As(V) and P(V) additions, and plant phosphorus (P) status, on As(V) uptake by canola (Brassica napus L.) and (ii), P(V) and As(V) interactions at the surface of roots and specific soil particles (goethite and kaolinite). Results showed that P-deficient canola took up more As(V) from arsenated kaolinite, but transported less As from roots to shoots, than P-adequate canola. The addition of P(V) adsorbed on substrate increased As(V) uptake by canola but desorption experiments revealed that the addition of phosphated kaolinite to arsenated kaolinite was not likely to increase As(V) availability in the rhizosphere. It was concluded that plant P status together with P(V) and As(V) interactions at the surfaces of roots and soil particles need to be considered to properly asses P(V) and As(V) interactions in the plant–soil continuum.
Turgor, solute import and growth in maize roots treated with galactose
Authors: Pritchard Jeremy , Tomos A. Deri , Farrar John F. , Minchin Peter E. H. , Gould Nick , Paul Matthew J. , MacRae Elspeth A. , Ferrieri Richard A. , Gray Dennis W. , Thorpe Michael R.
Published: November 2004

It has been observed that extension growth in maize roots is almost stopped by exposure to 5 mm d-galactose in the root medium, while the import of recent photoassimilate into the entire root system is temporarily promoted by the same treatment. The aim of this study was to reconcile these two apparently incompatible observations. We examined events near the root tip before and after galactose treatment since the tip region is the site of elongation and of high carbon deposition in the root. The treatment rapidly decreased root extension along the whole growing zone. In contrast, turgor pressure, measured directly with the pressure probe in the cortical cells of the growing zone, rapidly increased by 0.15 MPa within the first hour following treatment, and the increase was maintained over the following 24 h. Both tensiometric measurements and a comparison of turgor pressure with local growth rate demonstrated that a rapid tightening of the cell wall caused the reduction in growth. Single cell sampling showed cell osmotic pressure increased by 0.3 MPa owing to accumulation of both organic and inorganic solutes. The corresponding change in cell water potential was a rise from –0.18 MPa to approximately zero. More mature cells at 14 mm from the root tip (just outside the growing region) showed a qualitatively similar response. Galactose treatment rapidly increased the import of recently fixed carbon (RFC) into the whole root as deduced by 11C labelling of photoassimilate. In contrast, there was a significant decrease in import of recently fixed carbon into the apical 5mm concomitant with the increase in turgor in this region. No decrease in import of recently fixed carbon was observed 5–15 mm from the root tip despite the increase in cortical cell turgor. These data are consistent with direct symplastic connections between the growing cells and the phloem supplying the solutes in the apical, but not the basal, regions of the growing zone. Hence, the inhibition of growth and the elevation of solute import induced by galactose are spatially separated within the root.
Cytolytic CD8+ T Cells Recognizing CFP10 Are Recruited to the Lung after Mycobacterium tuberculosis Infection
Authors: Kamath Arati B. , Woodworth Joshua , Xiong Xiaowei , Taylor Chad , Weng Yu , Behar Samuel M.
Published: November 2004

Optimum immunity against Mycobacterium tuberculosis requires both CD4+ and CD8+ T cells. In contrast with CD4+ T cells, few antigens are known that elicit CD8+ T cells during infection. CD8+ T cells specific for culture filtrate protein-10 (CFP10) are found in purified protein derivative positive donors, suggesting that CFP10 primes CD8+ T cells in vivo. Using T cells from M. tuberculosis–infected mice, we identified CFP10 epitopes recognized by CD8+ T cells and CD4+ T cells. CFP10-specific T cells were detected as early as week 3 after infection and at their peak accounted for up to 30% of CD8+ T cells in the lung. IFNγ-producing CD8+ and CD4+ T cells recognizing CFP10 epitopes were preferentially recruited to the lungs of M. tuberculosis–infected mice. In vivo cytolytic activity of CD8+ T cells specific for CFP10 and TB10.3/10.4 proteins was detected in the spleen, pulmonary lymph nodes, and lungs of infected mice. The cytolytic activity persisted long term and could be detected 260 d after infection. This paper highlights the cytolytic function of antigen-specific CD8+ T cells elicited by M. tuberculosis infection and demonstrates that large numbers of CFP10-specific cytolytic CD8+ T cells are recruited to the lung after M. tuberculosis infection.
Famine Intensity and Magnitude Scales: A Proposal for an Instrumental Definition of Famine
Authors: Howe Paul , Devereux Stephen
Published: November 2004

Ambiguities in current usage of the term ‘famine’ have had tragic implications for response and accountability in a number of recent food crises. This paper proposes a new approach to defining famine based on the use of intensity and magnitude scales, where ‘intensity’ refers to the severity of the crisis at a given location and point in time, while ‘magnitude’ describes the aggregate impact of a crisis. The scales perform three operations on ‘famine’: first, moving from a binary conception of ‘famine/no famine’ to a graduated, multi‐level definition; second, disaggregating the dimensions of intensity and magnitude; and third, assigning harmonised ‘objective’ criteria in place of subjective, case‐by‐case judgements. If adopted, the famine scales should contribute to more effective and proportionate responses, as well as greater accountability in future food crises.
‘We All Knew that a Cyclone Was Coming’: Disaster Preparedness and the Cyclone of 1999 in Orissa, India
Authors: Thomalla Frank , Schmuck Hanna
Published: November 2004

Imagine that a cyclone is coming, but that those living in the affected areas do nothing or too little to protect themselves. This is precisely what happened in the coastal state of Orissa, India. Individuals and communities living in regions where natural hazards are a part of daily life develop strategies to cope with and adapt to the impacts of extreme events. In October 1999, a cyclone killed 10,000 people according to government statistics, however, the unofficial death toll is much higher. This article examines why such a large loss of life occurred and looks at measures taken since then to initiate comprehensive disaster‐preparedness programmes and to construct more cyclone shelters. The role of both governmental organisations and NGOs in this is critically analysed. The good news is that, based on an assessment of disaster preparedness during a small cyclone in November 2002, it can be seen that at community‐level awareness was high and that many of the lessons learnt in 1999 were put into practice. Less positive, however, is the finding that at the state level collaboration continues to be problematic.
Response of zooplankton to nutrient enrichment and fish in shallow lakes: a pan‐European mesocosm experiment
Authors: Vakkilainen Kirsi , Kairesalo Timo , Hietala Jaana , Balayla David M. , Bécares Eloy , Van de Bund Wouter J. , Van Donk Ellen , Fernández‐Aláez Margarita , Gyllström Mikael , Hansson Lars‐Anders , Miracle Maria R. , Moss Brian , Romo Susana , Rueda Juan , Stephen Deborah
Published: November 2004

1. Responses of zooplankton to nutrient enrichment and fish predation were studied in 1998 and 1999 by carrying out parallel mesocosm experiments in six lakes across Europe.

2. Zooplankton community structure, biomass and responses to nutrient and fish manipulation showed geographical and year‐to‐year differences. Fish had a greater influence than nutrients in regulating zooplankton biomass and especially the relative abundances of different functional groups of zooplankton. When fish reduced the biomass of large crustaceans, there was a complementary increase in the biomasses of smaller crustacean species and rotifers.

3. High abundance of submerged macrophytes provided refuge for zooplankton against fish predation but this refuge effect differed notably in magnitude among sites.

4. Large crustacean grazers (Daphnia, Diaphanosoma, Sida and Simocephalus) were crucial in controlling algal biomass, while smaller crustacean grazers and rotifers were of minor importance. Large grazers were able to control phytoplankton biomass even under hypereutrophic conditions (up to 1600 μg TP L−1) when grazer biomass was high (>80–90 μg dry mass L−1) or accounted for >30% of the grazer community.

5. The littoral zooplankton community was less resistant to change following nutrient enrichment in southern Spain, at high temperatures (close to 30 °C), than at lower temperatures (17–23 °C) characterising the other sites. This lower resistance was because of a greater importance of nutrients than zooplankton in controlling algal biomass.

6. Apart from the reduced role of large crustacean grazers at the lowest latitude, no consistent geographical patterns were observed in the responses of zooplankton communities to nutrient and fish manipulation.
Responses of phytoplankton to fish predation and nutrient loading in shallow lakes: a pan‐European mesocosm experiment
Authors: Van De Bund W. J. , Romo S. , Villena M. J. , Valentín M. , Van Donk E. , Vicente E. , Vakkilainen K. , Svensson M. , Stephen D. , Ståhl‐Delbanco A. , Rueda J. , Moss B. , Miracle M. R. , Kairesalo T. , Hansson L.‐A. , Hietala J. , Gyllström M. , Goma J. , García P. , Fernández‐Aláez M. , Fernández‐Aláez C. , Ferriol C. , Collings S. E. , Bécares E. , Balayla D. M. , Alfonso T.
Published: November 2004

1. The impacts of nutrients (phosphorus and nitrogen) and planktivorous fish on phytoplankton composition and biomass were studied in six shallow, macrophyte‐dominated lakes across Europe using mesocosm experiments.

2. Phytoplankton biomass was more influenced by nutrients than by densities of planktivorous fish. Nutrient addition resulted in increased algal biomass at all locations. In some experiments, a decrease was noted at the highest nutrient loadings, corresponding to added concentrations of 1 mg L−1 P and 10 mg L−1 N.

3. Chlorophyll a was a more precise parameter to quantify phytoplankton biomass than algal biovolume, with lower within‐treatment variability.

4. Higher densities of planktivorous fish shifted phytoplankton composition toward smaller algae (GALD < 50 μm). High nutrient loadings selected in favour of chlorophytes and cyanobacteria, while biovolumes of diatoms and dinophytes decreased. High temperatures also may increase the contribution of cyanobacteria to total phytoplankton biovolume in shallow lakes.
Mis‐marketing the Conservatives: The Limitations of Style over Substance
Authors: LEES‐MARSHMENT JENNIFER
Published: November 2004

Every Tory leader since 1997 has made significant attempts to use marketing; the most recent, Michael Howard, appointed the first ever UK party Marketing Director to head a specialised Marketing Department. However, whilst the Conservatives have made use of the tools of marketing (polling, focus groups, public listening exercises, communication) they have misunderstood the concept of political marketing, which is concerned with creating a unified political product that is responsive to voter demands. Political marketing has hitherto not worked for the Conservative party. This is because there is a lack of a supportive internal culture that accepts the party change necessary to produce a market‐orientated political product including policy, leadership and candidates. If political marketing is only used to sell a product that the party elite rather than the British public wants, it will never help the Conservatives regain control of government.
Money Matters: The Financing of the Conservative Party
Authors: FISHER JUSTIN
Published: November 2004

The article examines the financing of the Conservative Party in the aftermath of the 2001 general election. An examination of the party's income and expenditure shows that pre‐2001 patterns remain ‐ the Conservatives are the poorer of the two main parties but continue to be the principal recipient of corporate and in‐kind donations. However, the article also demonstrates that income rose sharply in the aftermath of the change of leadership in 2003, suggesting that this change may have stimulated donations. Also, as for other parties, questions of probity continue to arise following larger donations but, like Labour, the Conservatives oppose any caps on political giving.
A Multinational Perspective on Capital Structure Choice and Internal Capital Markets
Authors: DESAI MIHIR A. , FOLEY C. FRITZ , HINES JAMES R.
Published: November 2004

This paper analyzes the capital structures of foreign affiliates and internal capital markets of multinational corporations. Ten percent higher local tax rates are associated with 2.8% higher debt/asset ratios, with internal borrowing being particularly sensitive to taxes. Multinational affiliates are financed with less external debt in countries with underdeveloped capital markets or weak creditor rights, reflecting significantly higher local borrowing costs. Instrumental variable analysis indicates that greater borrowing from parent companies substitutes for three‐quarters of reduced external borrowing induced by capital market conditions. Multinational firms appear to employ internal capital markets opportunistically to overcome imperfections in external capital markets.
Does Stock Return Momentum Explain the “Smart Money” Effect?
Authors: SAPP TRAVIS , TIWARI ASHISH
Published: November 2004

Does the “smart money” effect documented by Gruber (1996) and Zheng (1999) reflect fund selection ability of mutual fund investors? We examine the finding that investors are able to predict mutual fund performance and invest accordingly. We show that the smart money effect is explained by the stock return momentum phenomenon documented by Jegadeesh and Titman (1993). Further evidence suggests investors do not select funds based on a momentum investing style, but rather simply chase funds that were recent winners. Our finding that a common factor in stock returns explains the smart money effect offers no affirmation of investor fund selection ability.
Price Discovery in the U.S. Treasury Market: The Impact of Orderflow and Liquidity on the Yield Curve
Authors: BRANDT MICHAEL W. , KAVAJECZ KENNETH A.
Published: November 2004

We examine the role of price discovery in the U.S. Treasury market through the empirical relationship between orderflow, liquidity, and the yield curve. We find that orderflow imbalances (excess buying or selling pressure) account for up to 26% of the day‐to‐day variation in yields on days without major macroeconomic announcements. The effect of orderflow on yields is permanent and strongest when liquidity is low. All of the evidence points toward an important role of price discovery in understanding the behavior of the yield curve.
Stresses in Polyethylene Liners in a Semiconstrained Ankle Prosthesis
Authors: Miller M. C. , Smolinski P. , Conti S. , Galik K.
Published: November 2004

A finite element model of a semiconstrained ankle implant with the tibia and fibula was constructed so that the stresses in the polyethylene liner could be computed. Two different widths of talar components were studied and proximal boundary conditions were computed from an inverse process providing a load of five times body weight appropriately distributed across the osseous structures. von Mises stresses indicated small regions of localized yielding and contact stresses that were similar to those in acetabular cup liners. A wider talar component with 36% more surface area reduced contact stress and von Mises stresses at the center of the polyethylene component by 17%.
The Mycobacterial Heparin-Binding Hemagglutinin Is a Protective Antigen in the Mouse Aerosol Challenge Model of Tuberculosis
Authors: Parra Marcela , Pickett Thames , Delogu Giovanni , Dheenadhayalan Veerabadran , Debrie Anne-Sophie , Locht Camille , Brennan Michael J.
Published: November 2004

The heparin-binding hemagglutinin (HBHA) of
Mycobacterium tuberculosis
is a surface-expressed adhesin that can affect binding to host cells via a unique, methylated, carboxyl-terminal, lysine-, alanine-, and proline-rich repeat region. It has been implicated in extrapulmonary dissemination of
M. tuberculosis
from the lung following the initial infection of the host. To assess the vaccine potential of this protein, purified preparations of HBHA were emulsified in a dimethyldioctadecylammonium bromide-monophosphoryl lipid A adjuvant and tested for the ability to reduce
M. tuberculosis
infection in the mouse aerosol challenge model for tuberculosis. The HBHA-containing vaccine gave a ∼0.7-log reduction in CFU in both mouse lungs and spleens compared to adjuvant controls 28 days following challenge. Although a notable level of serum antibody to HBHA was elicited after three immunizations and the antibodies were able to bind to the surface of
M. tuberculosis
, passive immunization with monoclonal antibodies directed against HBHA did not protect in the challenge model. Compared to adjuvant controls, an elevated gamma interferon response was generated by splenic and lymph node-derived T cells from immunized mice in the presence of macrophages pulsed with purified HBHA or infected with live
M. tuberculosis
, suggesting that the effective immunity may be cell mediated. Efforts to construct effective recombinant HBHA vaccines in fast-growing
Mycobacterium smegmatis
have been unsuccessful so far, which indicates that distinctive posttranslational modifications present in the HBHA protein expressed by
M. tuberculosis
are critical for generating effective host immune responses. The vaccine studies described here demonstrate that HBHA is a promising new vaccine candidate for tuberculosis.
Vesicular Transport Is Not Required for the Cytoplasmic Pool of Cholera Toxin To Interact with the Stimulatory Alpha Subunit of the Heterotrimeric G Protein
Authors: Teter Ken , Jobling Michael G. , Holmes Randall K.
Published: November 2004

Cholera toxin (CT) moves from the cell surface to the endoplasmic reticulum (ER) by retrograde vesicular transport. The catalytic A1 polypeptide of CT (CTA1) then crosses the ER membrane, enters the cytosol, ADP-ribosylates the stimulatory α subunit of the heterotrimeric G protein (Gsα) at the cytoplasmic face of the plasma membrane, and activates adenylate cyclase. The cytosolic pool of CTA1 may reach the plasma membrane and its Gsα target by traveling on anterograde-directed transport vesicles. We examined this possibility with the use of a plasmid-based transfection system that directed newly synthesized CTA1 to either the ER lumen or the cytosol of CHO cells. Such a system allowed us to bypass the CT retrograde trafficking itinerary from the cell surface to the ER. Previous work has shown that the ER-localized pool of CTA1 is rapidly exported from the ER to the cytosol. Expression of CTA1 in either the ER or the cytosol led to the activation of Gsα, and Gsα activation was not inhibited in transfected cells exposed to drugs that inhibit vesicular traffic. Thus, anterograde transport from the ER to the plasma membrane is not required for the cytotoxic action of CTA1.
Analysis of the Immune Response toMycobacterium aviumsubsp.paratuberculosisin Experimentally Infected Calves
Authors: Koo Hye Cheong , Park Yong Ho , Hamilton Mary Jo , Barrington George M. , Davies Christopher J. , Kim Jong Bae , Dahl John L. , Waters W. Ray , Davis William C.
Published: November 2004

Johne's disease of cattle is widespread and causes significant economic loss to producers. Control has been hindered by limited understanding of the immune response to the causative agent,Mycobacterium aviumsubsp.paratuberculosis, and lack of an effective vaccine and sensitive specific diagnostic assays. The present study was conducted to gain insight into factors affecting the immune response toM. aviumsubsp.paratuberculosis. A persistent proliferative response toM. aviumsubsp.paratuberculosispurified protein derivative and solubleM. aviumsubsp.paratuberculosisantigens was detected in orally infected neonatal calves 6 months postinfection (p.i.) by flow cytometry (FC). CD4+T cells with a memory phenotype (CD45R0+) expressing CD25 and CD26 were the predominant cell type responding to antigens. Few CD8+T cells proliferated in response to antigens until 18 months p.i. γδ T cells did not appear to respond to antigen until 18 months p.i. The majority of WC1+CD2−and a few WC1−CD2+γδ T cells expressed CD25 at time zero. By 18 months, however, subsets of γδ T cells from both control and infected animals showed an increase in expression of CD25, ACT2, and CD26 in the presence of the antigens. Two populations of CD3−non-T non-B null cells, CD2+and CD2−, proliferated in cell cultures from some control and infected animals during the study, with and without antigen. The studies clearly show multicolor FC offers a consistent reliable way to monitor the evolution and changes in the immune response toM. aviumsubsp.paratuberculosisthat occur during disease progression.
Fine Mapping of the N-Terminal Cytotoxicity Region of
Clostridium perfringens
Enterotoxin by Site-Directed Mutagenesis
Authors: Smedley James G. , McClane Bruce A.
Published: November 2004

Clostridium perfringens
enterotoxin (CPE) has a unique mechanism of action that results in the formation of large, sodium dodecyl sulfate-resistant complexes involving tight junction proteins; those complexes then induce plasma membrane permeability alterations in host intestinal epithelial cells, leading to cell death and epithelial desquamation. Previous deletion and point mutational studies mapped CPE receptor binding activity to the toxin's extreme C terminus. Those earlier analyses also determined that an N-terminal CPE region between residues D45 and G53 is required for large complex formation and cytotoxicity. To more finely map this N-terminal cytotoxicity region, site-directed mutagenesis was performed with recombinant CPE (rCPE). Alanine-scanning mutagenesis produced one rCPE variant, D48A, that failed to form large complexes or induce cytotoxicity, despite having normal ability to bind and form the small complex. Two saturation variants, D48E and D48N, also had a phenotype resembling that of the D48A variant, indicating that both size and charge are important at CPE residue 48. Another alanine substitution rCPE variant, I51A, was highly attenuated for large complex formation and cytotoxicity, but rCPE saturation variants I51L and I51V displayed a normal large complex formation and cytotoxicity phenotype. Collectively, these mutagenesis results identify a core CPE sequence extending from residues G47 to I51 that directly participates in large complex formation and cytotoxicity.
TheLeishmania majorLACK Antigen with an Immunodominant Epitope at Amino Acids 156 to 173 Is Not Required for Early Th2 Development in BALB/c Mice
Authors: Kelly Ben L. , Locksley Richard M.
Published: November 2004

TheLeishmania majorLACK antigen contains an immunodominant epitope at amino acids 156 to 173 (LACK156-173) that is believed to nucleate the pathological Th2 immune response in susceptible BALB/c mice. To test this hypothesis, we generatedL. majorparasites that express a mutated LACK that fails to activate Vβ4/Vα8 T-cell receptor transgenic T cells specific for this epitope. Although mutant parasites attenuated the expansion of endogenous LACK-specific, interleukin-4 (IL-4)-expressing, CD4 T cells compared to wild-type parasites in vivo, the overall frequency of IL-4 and gamma interferon-secreting lymphocytes was similar to that elicited by wild-typeL. major. Mutant parasites demonstrated diminished amastigote viability and delayed lesion development in mice, although parasites could be recovered over 200 days after infection. Complementation with a wild-typelackfusion construct partially rescued these defects, indicating a role for endogenous LACK in parasitism. Mice inoculated with mutant parasites were not protected against subsequent infection with wild-typeL. major.
Hemozoin Differentially Regulates Proinflammatory Cytokine Production in Human Immunodeficiency Virus-Seropositive and -Seronegative Women with Placental Malaria
Authors: Moore Julie M. , Chaisavaneeyakorn Sujittra , Perkins Douglas J. , Othoro Caroline , Otieno Juliana , Nahlen Bernard L. , Shi Ya Ping , Udhayakumar Venkatachalam
Published: November 2004

Pregnant women are at an increased risk for malarial infection.
Plasmodium falciparum
accumulates in the placenta and is associated with dysregulated immune function and poor birth outcomes. Malarial pigment (hemozoin) also accumulates in the placenta and may modulate local immune function. In this study, the impact of hemozoin on cytokine production by intervillous blood mononuclear cells from malaria-infected placentas was investigated. There was a dose-dependent, suppressive effect of hemozoin on production of gamma interferon (IFN-γ), with less of an effect on tumor necrosis factor alpha (TNF-α) and interleukin-10, in human immunodeficiency virus-seronegative (HIV
−
) women. In contrast, IFN-γ and TNF-α production tended to increase in HIV-seropositive women with increasing hemozoin levels. Production patterns of cytokines, especially IFN-γ in HIV
−
women, followed different trends as a function of parasite density and hemozoin level. The findings suggest that the influences of hemozoin accumulation and high-density parasitemia on placental cytokine production are not equivalent and may involve different mechanisms, all of which may operate differently in the context of HIV infection. Cytokine production dysregulated by accumulation of hemozoin or high-density parasitemia may induce pathology and impair protective immunity in HIV-infected and -uninfected women.
Yersinia enterocoliticaInduces Apoptosis and Inhibits Surface Molecule Expression and Cytokine Production in Murine Dendritic Cells
Authors: Erfurth Stella E. , Gröbner Sabine , Kramer Uwe , Gunst Dani S. J. , Soldanova Irena , Schaller Martin , Autenrieth Ingo B. , Borgmann Stefan
Published: November 2004

Yersinia enterocoliticaevades innate immunity by expression of a variety of pathogenicity factors. Therefore, adaptive immunity including CD4+T cells plays an important role in defense againstY. enterocolitica. We investigated whetherY. enterocoliticamight target dendritic cells (DC) involved in adaptive T-cell responses. For this purpose, murine DC were infected withY. enterocoliticawild-type and mutant strains prior to incubation with ovalbumin (OVA) as antigen and 5-(6)-carboxyfluorescein diacetateN-succinimidyl ester-labeled OVA-specific T cells from DO11.10 mice. While T-cell proliferation was partially affected by infection of DC with plasmid-cured and YopP-deficientYersiniamutant strains, no T-cell proliferation occurred after infection of DC with wild-typeY. enterocolitica. Infection of DC withY. enterocoliticawild type resulted in decreased up-regulation of major histocompatibility complex class II, CD54 (intercellular adhesion molecule 1), CD 80, and CD86 expression. Experiments with plasmid-curedY. enterocoliticaor a YopP-deficient mutant strain revealed that YopP accounts for inhibition of surface molecule expression. Wild-typeY. enterocoliticasuppressed the release of KC, tumor necrosis factor alpha, interleukin-10 (IL-10), and IL-12 by DC, while infection of DC with plasmid-curedY. enterocoliticaor with the YopP-deficient mutant resulted in the production of these cytokines. Moreover, infection with wild-typeY. enterocoliticainduced apoptosis in DC mediated by YopP. Apoptosis occurred despite translocation of NF-κB to the nucleus, as demonstrated by electromobility shift assays. Together, these data demonstrate thatY. enterocoliticatargets functions of murine DC that are required for T-cell activation. This might contribute to evasion of adaptive immune responses byY. enterocolitica.