bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural characterization of the human Nogo‐A functional domains
Authors: Li Minfen , Shi Jiahai , Wei Zheng , Teng Felicia Y. H. , Tang Bor Luen , Song Jianxing
Published: August 2004

The recent discovery of the Nogo family of myelin inhibitors and the Nogo‐66 receptor opens up a very promising avenue for the development of therapeutic agents for treating spinal cord injury. Nogo‐A, the largest member of the Nogo family, is a multidomain protein containing at least two regions responsible for inhibiting central nervous system (CNS) regeneration. So far, no structural information is available for Nogo‐A or any of its structural domains. We have subcloned and expressed two Nogo‐A fragments, namely the 182 residue Nogo‐A(567–748) and the 66 residue Nogo‐66 in Escherichia coli. CD and NMR characterization indicated that Nogo‐A(567–748) was only partially structured while Nogo‐66 was highly insoluble. Nogo‐40, a truncated form of Nogo‐66, has been previously shown to be a Nogo‐66 receptor antagonist that is able to enhance CNS neuronal regeneration. Detailed NMR examinations revealed that a Nogo‐40 peptide had intrinsic helix‐forming propensity, even in an aqueous environment. The NMR structure of Nogo‐40 was therefore determined in the presence of the helix‐stabilizing solvent trifluoroethanol. The solution structure of Nogo‐40 revealed two well‐defined helices linked by an unstructured loop, representing the first structure of Nogo‐66 receptor binding ligands. Our results provide the first structural insights into Nogo‐A functional domains and may have implications in further designs of peptide mimetics that would enhance CNS neuronal regeneration.
The function of D1‐H332 in Photosystem II electron transport studied by thermoluminescence and chlorophyll fluorescence in site‐directed mutants of Synechocystis 6803
Authors: Allahverdiyeva Yagut , Deák Zsuzsanna , Szilárd András , Diner Bruce A. , Nixon Peter J. , Vass Imre
Published: August 2004

The His332 residue of the D1 protein has been identified as the likely ligand of the catalytic Mn ions in the water oxidizing complex (Ferreira, K.N., Iverson, T.M., Maghlaoui, K., Barber, J. & Iwata, S. (2004) Science 303, 1831–1838). However, its function has not been fully clarified. Here we used thermoluminescence and flash‐induced chlorophyll fluorescence measurements to characterize the effect of the D1‐H333E, D1‐H332D and D1‐H332S mutations on the electron transport of Photosystem II in intact cells of the cyanobacterium Synechocystis 6803. Although the mutants are not photoautotrophic they all show flash‐induced thermoluminescence and chlorophyll fluorescence, which originate from the S2QA– and S2QB– recombinations demonstrating that charge stabilization takes place in the water oxidizing complex. However, the conversion of S2 to higher S states is inhibited and the energetic stability of the S2QA– charge pair is increased by 75, 50 and 7 mV in the D1‐H332D, D1‐H332E and D1‐H332S mutants, respectively. This is most probably caused by a decrease of Em(S2/S1). Concomitantly, the rate of electron donation from Mn to Tyr‐Zḃ during the S1 to S2 transition is slowed down, relative to the wild type, 350‐ and 60‐fold in the D1‐H332E and D1‐H332D mutants, respectively, but remains essentially unaffected in D1‐H332S. A further effect of the D1‐H332E and D1‐H332D mutations is the retardation of the QA to QB electron transfer step as an indirect consequence of the donor side modification. Our data show that although the His residue in the D1‐332 position can be substituted by other metal binding residues for binding photo‐oxidisable Mn it is required for controlling the functional redox energetics of the Mn cluster.
Structural and functional comparison of 15S‐ and 15R‐specific cyclooxygenases from the coral Plexaura homomalla
Authors: Valmsen Karin , Boeglin William E. , Järving Ivar , Schneider Claus , Varvas Külliki , Brash Alan R. , Samel Nigulas
Published: August 2004

It has been known for 30 years that the gorgonian coral Plexaura homomalla contains either 15S‐ or 15R‐configuration prostaglandins (PGs), depending on its location in the Caribbean. Recently we showed that the 15R‐PGs in the R‐variety of P. homomalla are formed by a unique cyclooxygenase (COX) with 15R oxygenation specificity [Valmsen, K., Järving, I., Boeglin, W.E., Varvas, K., Koljak, R., Pehk, T., Brash, A.R. & Samel, N. (2001) Proc. Natl. Acad. Sci. USA98, 7700]. Here we describe the cloning and characterization of a closely related COX protein (97% amino acid sequence identity) from the S‐variety of P. homomalla. Functional expression of the S‐variant COX cDNA in Sf9 insect cells followed by incubation with exogenous arachidonic acid resulted in formation of PG products with > 98% 15S‐configuration. Mutational analysis was performed on a suggested active site determinant of C‐15 oxygenation specificity, position 349 (Val in all S‐specific COX, Ile in 15R‐COX). The 15S‐COX Val349 to Ile mutant formed 35% 15R‐PGs, while the reverse mutation in the 15R‐COX (Ile349Val) led to formation of 70% 15S‐products. This establishes position 349 as an important determinant of the product stereochemistry at C‐15. Our characterization of the enzyme variants demonstrates that very minor sequence divergence accounts for the content of epimeric PGs in the two variants of P. homomalla and that the differences do not arise by isomerization of the products.
Comparison of native and recombinant chlorite dismutase from Ideonella dechloratans
Authors: Danielsson Thorell Helena , Beyer Natascha H. , Heegaard Niels H. H. , Öhman Marcus , Nilsson Thomas
Published: August 2004

A detailed comparison between native chlorite dismutase from Ideonella dechloratans, and the recombinant version of the protein produced in Escherichia coli, suggests the presence of a covalent modification in the native enzyme. Although the native and recombinant N‐ and C‐terminal sequences are identical, the enzymes display different electrophoretic mobilities, and produce different peptide maps upon digestion with trypsin and separation of fragments using capillary electrophoresis. Comparison of MALDI mass spectra of tryptic peptides from the native and recombinant enzymes suggests two locations for modification in the native protein. Mass spectrometric analysis of isolated peptides from a tryptic digest of the native enzyme identifies a possible cross‐linked dipeptide, suggesting an intrachain cross‐link in the parent protein. Spectrophotometric titration of the native enzyme in the denatured state reveals two titrating components absorbing at 295 nm, suggesting the presence of about one tyrosine residue per subunit with an anomalously low pKa. The EPR spectrum for the recombinant enzyme is different from that of the native enzyme, and contains a substantial contribution of a low‐spin species with the characteristics of bis‐histidine coordination. These results are discussed in terms of a covalent cross‐link between a histidine and a tyrosine sidechain, similar to those found in other heme enzymes operating under highly oxidizing conditions.
Sequence selective binding of bis‐daunorubicin WP631 to DNA
Authors: Fox Keith R. , Webster Richard , Phelps Robin J. , Fokt Izabela , Priebe Waldemar
Published: August 2004

We have used footprinting techniques on a wide range of natural and synthetic footprinting substrates to examine the sequence‐selective interaction of the bis‐daunorubicin antibiotic WP631 with DNA. The ligand produces clear DNase I footprints that are very different from those seen with other anthracycline antibiotics such as daunorubicin and nogalamycin. Footprints are found in a diverse range of sequences, many of which are rich in GT (AC) or GA (TC) residues. As expected, the ligand binds well to the sequences CGTACG and CGATCG, but clear footprints are also found at hexanucleotide sequences such GCATGC and GCTAGC. The various footprints do not contain any particular unique di‐, tri‐ or tetranucleotide sequences, but are frequently contain the sequence (G/C)(A/T)(A/T)(G/C). All sequences with this composition are protected by the ligand, though it can also bind to some sites that differ from this consensus by one base pair.
Noncytotoxic ribonuclease, RNase T1, induces tumor cell death via hemagglutinating virus of Japan envelope vector
Authors: Yuki Shunji , Kondo Yoshitaka , Kato Fuminori , Kato Masanari , Matsuo Norifusa
Published: August 2004

Several ribonucleases, including onconase and α‐sarcin, are known to be toxic to tumor cells. On the other hand, although its structure is related to that of α‐sarcin, RNase T1 is noncytotoxic because of its inability to internalize into tumor cells. In this study, we internalized RNase T1 into human tumor cells via a novel gene transfer reagent, hemagglutinating virus of Japan (HVJ) envelope vector, which resulted in cell death. This cytotoxicity was drastically increased by pretreatment of HVJ envelope vector with protamine sulfate, and was stronger than that of onconase, which is in phase III human clinical trials as a nonmutagenic cancer chemotherapeutic agent. Furthermore, internalized RNase T1 induced apoptotic cell death programs. Because its cytotoxicity is unfortunately not specific to tumor cells, it cannot at present be developed as an anticancer drug. However, we believe that RNase T1 incorporated in HVJ envelope vector will be a unique anticancer drug if HVJ envelope vector can be targeted to tumor cells.
Large aggregating and small leucine‐rich proteoglycans are degraded by different pathways and at different rates in tendon
Authors: Samiric Tom , Ilic Mirna Z. , Handley Christopher J.
Published: August 2004

This work investigated the kinetics of catabolism and the catabolic fate of the newly synthesized 35S‐labelled proteoglycans present in explant cultures of tendon. Tissue from the proximal region of bovine deep flexor tendon was incubated with [35S]sulfate for 6 h and then placed in explant cultures for periods of up to 15 days. The amount of radiolabel associated with proteoglycans and free [35S]sulfate lost to the medium and retained in the matrix was determined for each day in culture. It was shown that the rate of catabolism of radiolabelled small proteoglycans (decorin and biglycan) was significantly slower (T½ > 20 days) compared with the radiolabelled large proteoglycans (aggrecan and versican) that were rapidly lost from the tissue (T½ ≈ 2 days). Both the small and large newly synthesized proteoglycans were lost from the matrix with either intact or proteolytically modified core proteins. When explant cultures of tendon were maintained either at 4 °C or in the presence of the lysosomotrophic agent ammonium chloride, inhibition of the cellular catabolic pathway for small proteoglycans was demonstrated indicating the involvement of cellular activity and lysosomes in the catabolism of small proteoglycans. It was estimated from these studies that approximately 60% of the radiolabelled small proteoglycans that were lost from the tissue were degraded by the intracellular pathway present in tendon cells. This work shows that the pathways of catabolism for large aggregating and small leucine‐rich proteoglycans are different in tendon and this may reflect the roles that these two populations of proteoglycans play in the maintenance of the extracellular matrix of tendon.
Experimental evidence for costs of parasitism for a threatened species, White Sands pupfish (Cyprinodon tularosa)
Authors: COLLYER MICHAEL L. , STOCKWELL CRAIG A.
Published: August 2004

We used field and experimental data to test if white grub parasites (Diplostomatidae) are costly to White Sands pupfish (Cyprinodon tularosa), a threatened species restricted to four sites in the Chihuahuan desert, New Mexico.

Of the four populations ofC. tularosa, two are native and two are introduced. The two native populations (Malpais Spring and Salt Creek) are genetically distinct and have been isolated historically in dissimilar aquatic habitats (brackish spring and saline river, respectively). Two populations were establishedc. 1970 from translocation of Salt Creek fish to another saline river (Lost River) and another brackish spring (Mound Spring).

Physid snails (Physidae) occur in the two brackish spring habitats but not the saline river habitats. These snails are first intermediate hosts for white grubs (Diplostomatidae). Therefore, the two freshwater populations are infected by diplostomatids. For the Mound Spring population, the ecological relationship ofC. tularosaand diplostomatids has only recently occurred.

In 1995, a population crash occurred forC. tularosaat Mound Spring, associated with a parasite outbreak. Diplostomatids were the presumptive cause of this crash, but this was inferred from observation of infection in collected fish.

Two years of seasonal sampling of the two populations revealed that all collected fish were infected. Parasite intensities were significantly lower in winter compared to summer, suggesting that heavily infected fish were lost from the population on a seasonal basis.

We conducted an artificial infection experiment to assess the costs of parasitism for previously uninfectedC. tularosafemales for various life‐history traits. Under experimental conditions, diplostomatid infection caused increases inC. tularosamortality and decreases in growth and fat storage. Individual‐level costs of parasitism may translate to population‐level patterns of parasitism forC. tularosapopulations. Results from this study suggest that parasites may impact host overwinter survival, which is consistent with lower parasite intensities found during winters in wild populations.
Population responses to perturbations: predictions and responses from laboratory mite populations
Authors: BENTON T. G. , CAMERON T. C. , GRANT A.
Published: August 2004

Mathematical models are frequently used to make predictions of the response of a population to management interventions or environmental perturbations, but it is rarely possible to make controlled or replicated tests of the accuracy of these predictions.

We report results from replicated laboratory experiments on populations of a soil mite, Sancassania berlesei, living in ‘constant’ or ‘variable’ environments. We experimentally perturbed vital rates, via selective harvesting, and examined the population‐level responses. The response depends on the stage manipulated and whether there is environmental variability. Increased mortality usually decreased population size and increased population variability. However, egg mortality in a variable environment increased total population size.

We used time‐series analysis to construct a stage‐based population model of this system, incorporating the responses to both density and variation in food supply.

The time‐series model qualitatively captures the population dynamics, but does not predict well the way the populations will respond to the change in mortality. Elasticity analysis, conducted on the model's output, therefore did not lead to accurate predictions.

The presence of indirect positive population effects of a negative perturbation, but only in a variable environment, suggests that predicting the population response will require the incorporation of density dependence and environmental stochasticity. That the considerable biological complexity of our time‐series model did not allow accurate predictions suggests that accurate prediction requires modelling processes within a stage class rather than trying to make do with simple functions of total density.
Fitness consequences of host selection in ectoparasites: testing reproductive patterns predicted by isodar theory in fleas parasitizing rodents
Authors: KRASNOV BORIS R. , KHOKHLOVA IRINA S. , BURDELOVA NADEZHDA V. , MIRZOYAN NATELLA S. , DEGEN ALLAN A.
Published: August 2004

Fleas Xenopsylla conformis and Xenopsylla ramesis parasitize the rodents Meriones crassus and Gerbillus dasyurus. Previously reported isodar analysis of host selection suggested that at low density, X. conformis parasitizes M. crassus only, but with an increase in flea density, G. dasyurus is also parasitized. Xenopsylla ramesis at low density parasitizes both hosts equally, whereas at high density prefers M. crassus. The ultimate cause of underlying these patterns was suggested to be differential fitness reward of parasitism on a particular host species, while the mechanism can be adaptive host selection by fleas.

To justify the suggested fitness–density relations, we studied reproductive success in X. conformis and X. ramesis feeding on either M. crassus or G. dasyurus. We hypothesized that reproductive success would differ between two host species for each flea species.

Xenopsylla conformis parasitizing M. crassus produced more eggs than when parasitizing G. dasyurus, whereas time of oviposition and larval hatching did not depend on host species. In contrast, egg production in X. ramesis did not differ between host species. However, fleas fed on M. crassus needed fewer bloodmeals, oviposited earlier and hatching of their larvae took less time than those of fleas fed on G. dasyurus.

Patterns of egg production and development time in both fleas were consistent with the hypothesis that their between‐host distribution arose from adaptive host selection strategy.
Influence of habitat quality, patch size and connectivity on colonization and extinction dynamics of collared pikasOchotona collaris
Authors: FRANKEN RENEE J. , HIK DAVID S.
Published: August 2004

The effects of habitat quality, patch size and connectivity between patches on patterns of local extinction and colonization of collared pikas were studied over 7 years in alpine meadows in the south‐west Yukon.

Although adult population size independently had a significant influence on patch extinction, its influence was minimal when other variables were included in generalized linear models. Instead, an index of habitat quality and the connectivity of a patch were found to be the best predictors of pika extinction.

Similarly, patch connectivity only partly explained the recolonization of talus patches by pikas. Other patch characteristics, including aspect, amount of vegetation within the patch and an index of habitat quality based on survival probability of pikas also had a significant influence on recolonization.

These results suggest that the influence of patch quality on local extinction and recolonization need to be more fully incorporated into metapopulation models.
The geographical range structure of the holly leaf‐miner. IV. Effects of variation in host‐plant quality
Authors: GASTON KEVIN J. , GENNEY DAVID R. , THURLOW MADDIE , HARTLEY SUE E.
Published: August 2004

Spatial variation and covariation in host‐plant quality, herbivore abundance and herbivore mortality were examined across the natural geographical range in Europe of hollyIlex aquifoliumand the host‐specific holly leaf‐minerPhytomyza ilicis.

Although measures of host‐plant quality showed substantial between‐site variation, no simple spatial pattern in any of the measures (only phosphorus content and leaf mass showed correlations with latitude, longitude or altitude) was detected, and few correlations with tree or local site characteristics.

In contrast, measures of the abundance of the leaf‐miner exhibited marked spatial patterns, resulting in a lack of simple covariance between leaf‐miner abundance and host‐plant quality.

Different apparent mortalities of the leaf‐miner exhibited varied spatial patterns in their intensity, but no evidence of range‐wide density dependence, again resulting in few patterns of covariance between intensity of mortality and measures of host‐plant quality.

The population dynamics of the holly leaf‐miner across its geographical range are complex. At any site, the mortality that a population experiences is the sum of largely independent yet spatially structured components, against a background of varying host‐plant quality. Despite lacking any marked spatial structure, host‐plant quality may have important local effects. These are difficult to detect regionally, and thus may principally contribute noise to regional patterns of levels of oviposition, abundance and mortality.
Bottom‐up density regulation in the holly leaf‐miner Phytomyza ilicis
Authors: EBER SABINE
Published: August 2004

The holly leaf‐miner Phytomyza ilicis Curtis shows density patterns typical for non‐eruptive leaf‐miners, with stable mean densities, but consistently different infestation rates on individual trees.

To identify the mechanisms responsible for these patterns the population dynamics of P. ilicis were studied during an 8‐year period on 92 host trees in 15 holly patches. The patterns of oviposition, mining and survival and the dominant sources and rates of mortality were monitored. The impact of tree and patch parameters on leaf‐miner population dynamics was analysed, and the dispersal ability of P. ilicis was evaluated experimentally.

Infestation differences among trees were due to host selection, which determined egg numbers on individual trees and was explained partly by holly variety and leaf availability.

Egg distributions on medium to highly infested host trees were aggregated, suggesting limits in the availability of young leaves for oviposition.

Due to a suite of mortality factors mean survival rates of P. ilicis were below 10% and did not show a relationship with host choice.

There was strongly density‐dependent pre‐mine mortality most probably caused by intraspecific competition in the leaf midrib. This lead to the formation of a single mine on most leaves. There was a weak density‐dependent effect of mine density on miscellaneous larval death and on the attack rates of the larval parasitoid Chrysocaris gemma.

In the holly leaf‐miner system phenology effects set a population ceiling delimited by the availability of oviposition sites. The resulting egg distribution determined the impact of density‐dependent intraspecific competition in the leaf midrib. The incidence of larval competition was therefore not a function of density per se, but density‐relative to the availability of a limiting resource, namely suitable young leaves for oviposition.
Metabolic response to temperature variation in the great tit: an interpopulation comparison
Authors: BROGGI JULI , ORELL MARKKU , HOHTOLA ESA , NILSSON JAN–ÅKE
Published: August 2004

We studied the resting metabolic rate (MR) from two great titParus major(Linnaeus) populations living in different winter regimes. Birds from the two different localities were exposed individually to +25 °C, 0 °C and −10 °C for the night in three consecutive sessions in random order.

Birds from Lund (Sweden) had a lower basal MR, as measured at thermoneutrality (+25 °C), than had birds from Oulu (Finland). Nevertheless, below thermoneutrality, birds from Oulu spent relatively more energy, especially at −10 °C.

Although the energy needed for thermoregulation decreased with increasing basal MR this relation is at a higher metabolic cost for birds in Oulu than for birds in Lund.

The higher basal MR in Oulu is probably a consequence of a higher maximal MR needed in the severe cold. Further, the observed MRs below thermoneutrality are lower than expected from published data. This suggests that all birds were probably hypothermic at −10 °C, particularly Lund birds, and that the use of controlled hypothermia in great tits may be more common than thought previously. Great tits seem to rely primarily on metabolic adjustment to cope with the harsh climatic conditions in the northernmost parts of its distribution.
The Old and Thee, uh, New
Authors: Arnold Jennifer E. , Tanenhaus Michael K. , Altmann Rebecca J. , Fagnano Maria
Published: August 2004

Most research on the rapid mental processes of online language processing has been limited to the study of idealized, fluent utterances. Yet speakers are often disfluent, for example, saying “thee, uh, candle” instead of “the candle.” By monitoring listeners' eye movements to objects in a display, we demonstrated that the fluency of an article (“thee uh” vs. “the”) affects how listeners interpret the following noun. With a fluent article, listeners were biased toward an object that had been mentioned previously, but with a disfluent article, they were biased toward an object that had not been mentioned. These biases were apparent as early as lexical information became available, showing that disfluency affects the basic processes of decoding linguistic input.
Phonological Dyslexia
Authors: Vliet Elise Caccappolo-van , Miozzo Michele , Stern Yaakov
Published: August 2004

Following brain damage, skilled readers may encounter more severe problems in reading nonwords than familiar words, a type of deficit referred to as phonological dyslexia. We report on 2 individuals with Alzheimer's disease who show phonological dyslexia. Although highly accurate in reading familiar words aloud (even those with irregular spelling, such as sew), they were quite impaired in nonword reading. Both patients performed well in phonological tasks involving the repetition, identification, and manipulation of phonemes of orally presented words and nonwords. These results challenge the idea, proposed in the context of connectionist and evolutionary theories, that phonological dyslexia originates from a phonological deficit. However, the results are consistent with reading models, such as the dual-route model, that attribute phonological dyslexia to a deficit that selectively affects the reading mechanisms responsible for deriving the sounds of non-words. According to these models, such a deficit is not necessarily accompanied by a more general phonological impairment.
Youth Bulges in Communities
Authors: Hart Daniel , Atkins Robert , Markey Patrick , Youniss James
Published: August 2004

Youth bulges, cohorts of 16- to 25-year-olds disproportionately large relative to the adult population, are linked with social upheaval in historical research. Limited civic knowledge and heightened civic participation in adolescence, resulting from socialization in communities with large populations of children, are hypothesized to be developmental precursors to the political activism characteristic of youth constituting bulges. In two studies with nationally representative samples, adolescents in communities with disproportionately large populations of children were found to have less civic knowledge than equivalent adolescents in communities without large populations of children. In both studies, civic participation was predicted by the interaction of a community's proportion of children and its poverty level. Similar patterns were identified in a third study using country-level data. Together, the findings demonstrate that the youthfulness of communities and countries influences civic development.
Visual Search Does Not Remain Efficient When Executive Working Memory Is Working
Authors: Han Sang-Hoon , Kim Min-Shik
Published: August 2004

Working memory (WM) has been thought to include not only short-term memory stores but also executive processes that operate on the contents of memory. The present study examined the involvement of WM in search using a dual-task paradigm in which participants performed visual search while manipulating or simply maintaining information held in WM. Experiments 1a and 2a involved executive WM tasks that required counting backward from a target digit and sorting a string of letters alphabetically, respectively. In both experiments, the search slopes in the dual-task condition were significantly steeper than those in a search-alone condition, indicating that performing the WM manipulation tasks influenced the efficiency of visual search. In contrast, when information was simply maintained in WM (Experiments 1b and 2b), search slopes did not differ between the single- and dual-task conditions. These results suggest that WM resources related to executive functions may be required in visual search.
Independent Processing of Parts and of Their Spatial Organization in Complex Visual Objects
Authors: Arguin Martin , Saumier Daniel
Published: August 2004

A visual search experiment using synthetic three-dimensional objects is reported. The target shared its constituent parts, the spatial organization of its parts, or both with the distractors displayed with it. Sharing of parts and sharing of spatial organization both negatively affected visual search performance, and these effects were strictly additive. These findings support theories of complex visual object perception that assume a parsing of the stimulus into its higher-order constituents (volumetric parts or visible surfaces). The additivity of the effects demonstrates that information on parts and information on spatial organization are processed independently in visual search.
State‐owned enterprises going public The case of China
Authors: Wang Xiaozu , Xu Lixin Colin , Zhu Tian
Published: August 2004

Public listing is a key reform measure for large state‐owned enterprises (SOEs) in China. We find evidence that public listing lowers state ownership significantly, lessens firms’ reliance on debt finance, and allows firms to increase capital expenditure, at least temporarily. We also find that ownership structure affects post‐listing performance. However, we find no statistical evidence of a positive effect of public listing on firms’ profitability. We suggest alternative interpretations of the last finding.
What determines public education expenditures in Russia?1
Authors: Verbina Inna , Chowdhury Abdur
Published: August 2004

Recent studies suggest that the allocation of expenditures in education is important for growth. The state of public education spending in many transition economies highlights the need for an assessment of the nature of education expenditures in these countries. This paper attempts to fill this gap in the literature by estimating the determinants of education expenditures in the Russian Federation. Results from panel data analysis show that revenue and the student‐population ratio have a positive impact on education expenditures while the effect of population density is negative. Three regional variables also show significant impact. The income and price elasticity of public education expenditures are estimated to be 0.57 and −0.18, respectively, a result comparable to studies from other countries. The results presented here provide insight into how fiscal institutions and the structure of the political process in Russia may affect the degree of resource allocation in the educational sector during the transition process.
Do family resources matter? Educational attainment during transition in Poland*
Authors: Beblo Miriam , Lauer Charlotte
Published: August 2004

We analyse the relationship between family background and children's educational attainment in the 1990s in Poland. If parental poverty affects children's educational prospects, the increase in social inequalities observed in the Polish transition process will be transmitted between generations. We apply an ordered probit model of educational attainment on longitudinal data from the Polish Labour Force Survey. Surprisingly, parents’ income and their labour market status have only a weak impact on children's education. Parents’ schooling, however, is strongly related to children's, and so are household structure, city size, and region of residence. We conclude that, if transmission of inequality takes place between generations, this seems to be primarily caused by the inheritance of human capital rather than by pure wealth effects.
Multinational Diversification and Corporate Performance: Evidence from European Firms
Authors: Mathur Ike , Singh Manohar , Gleason Kimberly C.
Published: August 2004

We investigate the empirical relationship between accounting based measures of performance and the degree of multinational diversification for a set of European chemical industry firms. We find that for these firms, the degree of multinational diversification is strongly related to superior financial performance. The results hold for each of the three sample years. The findings suggest that multinational firms outperform purely domestic and exporting firms. The results provide strong support for gains from multinational diversification. The results indicate that while greater European unification may have eroded potential benefits of exploiting international capital and product market imperfections, the benefits of firm specific economies of scope and scale as well as managerial and financial synergies are still realised through exports.
Perceived peer smoking prevalence and its association with smoking behaviours and intentions in Hong Kong Chinese adolescents
Authors: Lai Man Kin , Ho Sai Yin , Lam Tai Hing
Published: August 2004

Background  Among the many personal, social and environmental risk factors of adolescence smoking, normative beliefs stand out for their potential to be modified with factual information on smoking prevalence.

Aims  To study the perceived peer smoking prevalence and its association with smoking behaviours in Hong Kong Chinese adolescents.

Design and setting  Cross‐sectional territorial‐wide school‐based survey conducted in 64 randomly selected secondary schools in Hong Kong.

Participants  A total of 13 280 forms 1–3 students (equivalent to grades 7–9 in the United States) aged 12–16 years.

Measurements  Perceived peer smoking prevalence, smoking status, intention to smoke in future, other smoking‐related factors and demographic information.

Findings  Overestimation of peer smoking prevalence was observed regardless of gender and smoking status, and was more common in girls (69.4%) than boys (61.0%), and in experimental (74.3%) and current smokers (85.4%) than in never smokers (60.7%). Boys who overestimated and grossly overestimated (over two times) peer smoking were more likely to be current smokers, with adjusted odds ratios and 95% confidence intervals (95% CI) of 1.95 (1.24–3.07) and 3.52 (2.37–5.24) (P for trend <0.001). Similarly, boys who grossly overestimated peer smoking were 76% (95% CI: 41–120%) more likely to have ever smoked.

Conclusion  Overestimation of peer smoking prevalence was common in Hong Kong Chinese boys and girls, and was associated with current and ever smoking in boys. These findings have important implications on normative education in adolescence smoking prevention programmes.
Alcohol abuse in a metropolitan city in China: a study of the prevalence and risk factors
Authors: Jiafang Zhang , Jiachun Wang , Yunxia Lu , Xiaoxia Qiu , Ya Fang
Published: August 2004

Aims  To investigate the prevalence of alcohol abuse in modern China and to explore the risk factors that may be associated with alcohol abuse.

Design  A face‐to‐face interview was carried out in a random sample with 2327 respondents.

Setting  Respondents were selected randomly from Wuhan City, Hubei Province, China, between May and June 2002.

Participants  Fifteen−65‐year‐old urban Chinese adults.

Measurements  Scores for alcohol abuse and related risk factors were the main measures.

Findings  (1) Nearly 15% of urban Chinese adults aged 15–65 were alcohol abusers. (2) Deviant drinking habits of mother, schoolmates, colleagues or friends all had a negative impact on the respondent's alcohol drinking behaviours, and higher economic status, current smokers, being male and being older were identified as risk factors related to alcohol abuse. In particular, if a drinker's mother used alcohol frequently then this drinker was more likely to become an alcohol abuser than those drinkers whose mothers did not use alcohol frequently (P = 0.0001). Fathers’ drinking behaviours do not have a significant impact on the alcohol abusers.

Conclusions  In addition to common risk factors such as economic status, deviant peers’ and fellows’ drinking behaviours and negative attitudes to alcohol drinking, maternal alcohol drinking habit influenced significantly the offspring's drinking habits. Therefore, efficient intervention and education of healthy drinking habits in early motherhood is necessary for Chinese women.
Randomized controlled trial of a brief behavioural intervention for reducing hepatitis C virus risk practices among injecting drug users
Authors: Tucker Thamizan , Fry Craig L. , Lintzeris Nick , Baldwin Simon , Ritter Alison , Donath Susan , Whelan Greg
Published: August 2004

Aim  To develop and evaluate a brief intervention for reducing risk behaviours associated with HCV transmission in injecting drug users (IDU).

Design  Randomized controlled trial of an individually tailored brief behavioural intervention (BBI) (experimental) versus a standardized educational intervention (control).

Setting  Specialist drug treatment facility in Melbourne, Australia.

Participants  One hundred and forty‐five IDU (aged 18 or over, injecting at least weekly in the preceding 6 months) recruited and randomized to the experimental condition (n = 73) or the control condition (n = 72).

Interventions  The BBI was based on the Blood‐Borne Virus Transmission Risk Assessment Questionnaire (BBV‐TRAQ)—a standardized blood‐borne virus risk assessment instrument comprising injecting risk, sexual risk and other skin penetration risk subscales. The BBV‐TRAQ was used to identify individual HCV risk practices and to tailor the 30‐minute experimental BBI. Control participants received a standardized HCV educational session, using current educational materials.

Main outcome measures  BBV‐TRAQ subscale and total scores and measures of participant satisfaction.

Results  One hundred and twenty‐four participants (86%) were followed‐up at 4 weeks (±7 days). Analyses revealed a significant reduction in HCV risk behaviours for both groups at 1‐month follow‐up, with participants in the experimental BBI condition reporting higher overall satisfaction with the intervention compared to the control group.

Conclusions  Both groups reported significant reductions in risk behaviour, indicating that while BBI methods hold promise for HCV education and prevention, they were not demonstrated to be more effective than the provision of standard educational materials. Future research could evaluate the efficacy of the BBV‐TRAQ as a risk behaviour intervention and counselling tool in clinical, NSP and peer education settings.
Longitudinal surveys of prevalence rates and use patterns of illicit drugs at selected high‐prevalence areas in China from 1993 to 2000
Authors: Hao Wei , Su Zhonghua , Xiao Shuiyuan , Fan Changhe , Chen Hongxian , Liu Tieqiao , Young Deson
Published: August 2004

Aims  To identify the prevalence, patterns and trends of illicit drug use in the general population of selected high‐prevalence areas in China between 1993 and 2000.

Design, setting and participants  Cluster sampling was employed and the Epidemiological Inventory for Illicit Drug Use (EIIDU) used as survey instrument. In 1993, 1996 and 2000, 56 792, 67 319 and 53 747 individuals aged 15 or above in community were interviewed, respectively, at the three time‐points.

Measurements  Demographics and drug‐related data were collected and the prevalence patterns of illicit drug are described.

Findings  The life‐time prevalences of illicit drug use in the three consecutive surveys in 1993, 1996 and 2000 were 1.08, 1.60 and 1.52%, respectively, and the 1‐year prevalence rates were 0.91, 1.17 and 1.17%, respectively. Heroin was the first choice for drug use (51.8% in 1993, 83.4% in 1993 and 95.9% in 2000). The two most frequent routes of drug administration were inhalation (89.2% in 1993, 60.1% in 1996 and 93.5% in 2000) and intravenous injection (27.2% in 1993, 31.0% in 1996 and 25.7% in 2000).

Conclusion  At least for the time being, illicit drug use may have plateaued in these selected high‐prevalence areas.
Respiration and annual fungal production associated with decomposing leaf litter in two streams
Authors: Carter M. D. , Suberkropp Keller
Published: August 2004

1. We compared fungal biomass, production and microbial respiration associated with decomposing leaves in one softwater stream (Payne Creek) and one hardwater stream (Lindsey Spring Branch).

2. Both streams received similar annual leaf litter fall (478–492 g m−2), but Lindsey Spring Branch had higher average monthly standing crop of leaf litter (69 ± 24 g m−2; mean ± SE) than Payne Creek (39 ± 9 g m−2).

3. Leaves sampled from Lindsey Spring Branch contained a higher mean concentration of fungal biomass (71 ± 11 mg g−1) than those from Payne Creek (54 ± 8 mg g−1). Maximum spore concentrations in the water of Lindsay Spring Branch were also higher than those in Payne Creek. These results agreed with litterbag studies of red maple (Acer rubrum) leaves, which decomposed faster (decay rate of 0.014 versus 0.004 day−1), exhibited higher maximum fungal biomass and had higher rates of fungal sporulation in Lindsey Spring Branch than in Payne Creek.

4. Rates of fungal production and respiration per g leaf were similar in the two streams, although rates of fungal production and respiration per square metre were higher in Lindsey Spring Branch than in Payne Creek because of the differences in leaf litter standing crop.

5. Annual fungal production was 16 ± 6 g m−2 (mean ± 95% CI) in Payne Creek and 46 ± 25 g m−2 in Lindsey Spring Branch. Measurements were taken through the autumn of 2 years to obtain an indication of inter‐year variability. Fungal production during October to January of the 2 years varied between 3 and 6 g m−2 in Payne Creek and 7–27 g m−2 in Lindsey Spring Branch.

6. Partial organic matter budgets constructed for both streams indicated that 3 ± 1% of leaf litter fall went into fungal production and 7 ± 2% was lost as respiration in Payne Creek. In Lindsey Spring Branch, fungal production accounted for 10 ± 5% of leaf litter fall and microbial respiration for 13 ± 9%.
Microbial activities in the burrow environment of the potamal mayfly Ephoron virgo
Authors: Stief Peter , Altmann Dörte , de Beer Dirk , Bieg Rosita , Kureck Armin
Published: August 2004

1. The impact of burrowing larvae of Ephoron virgo (Ephemeroptera, Polymitarcidae) on sediment microbiology has not been previously investigated because of difficulties in sampling the sediment of large rivers under in situ conditions. Therefore, we conducted experiments in the on‐ship Ecological Rhine Station of the University of Cologne (Germany), in which ambient conditions of the River Rhine can be closely mimicked.

2. In two consecutive seasons, experimental flow channels were stocked with Ephoron larvae and continuously supplied with water taken directly from the River Rhine. Sediment from the immediate vicinity of Ephoron burrows (i.e. U‐shaped cavities reaching 10–80 mm deep into the sediment) and bulk sediment samples were analysed for (i) particulate organic matter content, (ii) microscale in situ distribution of O2, NO, and NH, and (iii) potential activities of exoenzymes.

3. Sediment surrounding the Ephoron burrows had markedly higher organic matter contents and exoenzyme activities compared with the bulk sediment. Microsensor measurements demonstrated that local O2 and NO penetration into the sediment were greatly enhanced by larval ventilation behaviour. Volumetric O2 and NO turnover rates that were calculated from steady state concentration profiles measured directly in the burrow lining were considerably higher than at the sediment surface.

4. In the sediment of the fast flowing River Rhine Ephoron burrows are preferential sites of organic matter accumulation and dissolved oxidant penetration. Our data suggest that the burrows are surrounded by a highly active microbial community that responds to the inputs from the water column with elevated O2 and NO turnover, and release of exoenzymes into the sediment pore water. Especially during periods of mass occurrence, the larvae of E. virgo may thus significantly contribute (i) to the ecological connection between the water column and the sediment and (ii) to biogeochemical processing of organic matter in the riverbed.
Identifying the scales of variability in stream macroinvertebrate abundance, functional composition and assemblage structure
Authors: Heino Jani , Louhi Pauliina , Muotka Timo
Published: August 2004

1. Many natural ecosystems are heterogeneous at scales ranging from microhabitats to landscapes. Running waters are no exception in this regard, and their environmental heterogeneity is reflected in the distribution and abundance of stream organisms across multiple spatial scales.

2. We studied patchiness in benthic macroinvertebrate abundance and functional feeding group (FFG) composition at three spatial scales in a boreal river system. Our sampling design incorporated a set of fully nested scales, with three tributaries, two stream sections (orders) within each tributary, three riffles within each section and ten benthic samples in each riffle.

3. According to nested anovas, most of the variation in total macroinvertebrate abundance, abundances of FFGs, and number of taxa was accounted for by the among‐riffle and among‐sample scales. Such small‐scale variability reflected similar patterns of variation in in‐stream variables (moss cover, particle size, current velocity and depth). Scraper abundance, however, varied most at the scale of stream sections, probably mirroring variation in canopy cover.

4. Tributaries and stream sections within tributaries differed significantly in the structure and FFG composition of the macroinvertebrate assemblages. Furthermore, riffles in headwater (second order) sections were more variable than those in higher order (third order) sections.

5. Stream biomonitoring programs should consider this kind of scale‐dependent variability in assemblage characteristics because: (i) small‐scale variability in abundance suggests that a few replicate samples are not enough to capture macroinvertebrate assemblage variability present at a site, and (ii) riffles from the same stream may support widely differing benthic assemblages.
Coping strategies of family carers for older relatives in Finland
Authors: Kuuppelomäki Merja , Sasaki Akiko , Yamada Kouko , Asakawa Noriko , Shimanouchi Setsu
Published: August 2004

Background.  As the population continues to age, it is important that older people and their family carers get all the help and support they need with coping. This requires knowledge and understanding of the factors that foster and promote coping strategies, and on the other hand that complicate coping.

Aims and objectives.  Conducted as part of a major international research project on carers’ work and coping in four countries, the purpose of this study was to explore the coping strategies of family carers looking after older relatives in their own home and to identify related factors.

Design.  A survey involving 290 family carers from three towns in Finland.

Methods.  The data were collected with a questionnaire including the Carers’ Assessment of Managing Index developed by Nolan et al. (1995).

Results.  The most helpful coping strategy was to establish one's priorities and concentrate on them. Other strategies that over 80% of the respondents regarded as helpful were believing in oneself and one's ability to handle the situation, taking life 1 day at a time, looking for positive things in each situation and relying on one's own expertise and experience. The 10 most helpful coping methods included five problem‐solving strategies, four emotional‐cognitive strategies and one managing stress strategy. The age and gender of the family carers were found to correlate with the results.

Conclusions.  Our findings lend further support to earlier results according to which there are both similarities and differences in the coping strategies of family carers in different countries.

Relevance to clinical practice.  Nurses who meet family carers of ageing individuals in their work will be able to use these results in assessing how these carers are coping and whether they need support, as well as in developing services for family carers.