bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fireflies with or without prespermatophores: Evolutionary origins and life‐history consequences
Authors: Hayashi Fumio , Suzuki Hirobumi 
Published: December 2004

AbstractDuring mating, some male North American fireflies produce spermatophores from prespermatophores in their paired reproductive accessory glands. Other species of fireflies have neither prespermatophores nor spermatophores. To establish a pattern of spermatophore occurrence across firefly species, we examined the male internal reproductive system in 20 Japanese species belonging to 10 genera for the presence or absence of prespermatophores. Twelve species from seven genera produced prespermatophores, while eight species from three genera did not. Superimposed on a molecular phylogeny of Japanese fireflies based on mitochondrial 16S ribosomal DNA sequences, the basal group was prespermatophore producers. Prespermatophores appear to have been lost in two different lineages. Species without prespermatophores are characterized by degeneration of both the forewings and hindwings, and by body gigantism in females.
Improved methods for selective dissolution of manganese oxides from soils and rocks
Authors: Neaman A. , Waller B. , Mouélé F. , Trolard F. , Bourrié G. 
Published: December 2004

SummaryHydroxylamine hydrochloride (NH2OH‐HCl) and hydrogen peroxide (H2O2) have been used in the past for selective dissolution of manganese oxide minerals. The methods reported, however, give poor recoveries. We tried to improve the methods in this respect. By stoichiometry, incomplete dissolution of Mn oxides is due to the lack of NH2OH‐HCl added or to the lack of acid added in the case of H2O2 treatment. By increasing the amount of solution for a given amount of solid in the case of NH2OH‐HCl and by increasing the acid concentration in the case of H2O2 treatment, we obtained rapid and complete dissolution of synthetic Mn oxides. The dissolution of natural samples, however, was slower than that of synthetic ones. Based on the results obtained, the improved methods are: (i) 0.1 m NH2OH‐HCl, non‐acidified, 2 hours' stirring, and 1 g solid in 2 litres solution; (ii) 30% H2O2 in 0.5 m nitric acid, 0.5 hours' stirring, and 1 g solid in 1 litre solution. The improved methods achieved almost complete release of manganese from samples without decreasing the selectivity of dissolution.
Radio‐labile cadmium and zinc in soils as affected by pH and source of contamination
Authors: Degryse F. , Buekers J. , Smolders E. 
Published: December 2004

SummaryThe determination of radio‐labile metals in soil has gained renewed interest for predicting metal availability. There is little information on to what extent the fraction of labile metal is affected by the soil properties and the source of metal contamination. The radio‐labile content (E value) of Cd and Zn was measured in field‐collected soils with Cd and Zn originating from different sources. The E values were erratic and sometimes even exceeded total metal content when the concentration in the soil extract was less than 8 μg Zn l−1 or less than 3 μg Cd l−1. Addition of EDTA (0.1 mm) to the radio‐labelled soil suspension resulted in larger concentrations of Cd and Zn in solution and smaller E values for these soils. The E values were, however, unaffected by the presence of EDTA (0.1 mm) in soils with larger concentrations of Cd and Zn in solution.The %E values (E value relative to metal soluble in aqua regia) ranged from 9% to 92% (mean 61%) for Cd and from 3% to 72% (mean 33%) for Zn. No correlation between soil properties and %E was observed for Cd, and the %E of Zn was negatively correlated with soil pH (r = −0.65). There was a strong negative correlation between pH and %E in soils enriched with metals in soluble form (e.g. metal salts, corrosion of galvanized structures). In soils where Cd or Zn were added in a less soluble form, no such correlation was found, and %E values were generally less than in soils spiked with metal salts, suggesting that the source of the contamination controls mainly the labile fractions of Cd and Zn.
Increased frequency of the mannose‐binding lectin LX haplotype in Chinese systemic lupus erythematosus patients
Authors: Huang Y. F. , Wang W. , Han J. Y. , Wu X. W. , Zhang S. T. , Liu C. J. , Hu Q. G. , Xiong P. , Hamvas R. M. J. , Wood N. , Gong F. L. , Bittles A. H. 
Published: December 2004

SummaryMannose‐binding lectin (MBL) is an important complement‐activating protein of the human immune system. As a result of one of three structural gene mutations in exon 1 (variants B, C and D) and/or the presence of a low‐efficiency promoter polymorphism, MBL deficiency may be associated with increased susceptibility to infectious diseases and to autoimmune disorders, including systemic lupus erythematosus (SLE). Using a combined approach of heteroduplex generator and polymerase chain reaction, a systematic search for mutations in exon 1 and the promoter region of the MBL gene was performed in a Chinese study population comprising 41 SLE patients and 111 healthy controls. Two alleles, a wild‐type allele A and a variant allele B (a previously reported mutation of GGC to GAC at codon 54), were identified in MBL exon 1. The frequency of the B allele (0.15) was higher in the SLE patients than in the healthy controls (0.09), but the difference did not attain statistical significance (P > 0.05). However, for two polymorphisms at positions −550 and −221 in the promoter region, the frequency of the low‐MBL‐producing haplotype (LX) in the patients (0.2073) was significantly higher than that in the controls (0.0855) (P = 0.003, relative risk = 2.79). Our results suggest that the LX haplotype represents a strong risk factor among Chinese SLE patients. Although of lesser importance, the MBL B allele also may be a risk component in the developing process of SLE in Chinese patients.
Allele frequencies for an interferon‐γ microsatellite in a population of Brazilian leprosy patients
Authors: Reynard M. P. , Turner D. , Junqueira‐Kipnis A. P. , Ramos de Souza M. , Moreno C. , Navarrete C. V. 
Published: December 2004

SummaryA group of Brazilian leprosy patients and controls were genotyped for a CA‐repeat microsatellite polymorphism within the interferon (IFN)‐γ gene. A significantly higher frequency of alleles 5–7 was observed in this patient population, indicating that IFN‐γ gene polymorphism may contribute to the course of leprosy post‐infection.
HLA‐B*15 subtypes in the population of north‐eastern Thailand
Authors: Romphruk A. , Phongaen K. , Chotechai J. , Puapairoj C. , Leelayuwat C. , Romphruk A. V. 
Published: December 2004

SummaryThe HLA‐B*15 group is the most polymorphic HLA‐B allele and so has several subtypes. These subtypes have not been defined in the population of north‐eastern Thailand (NET). In a previous study, using polymerase chain reaction–sequence‐specific primers (PCR‐SSP), subtypes were categorized into four groups, namely: group I: HLA‐B*15 (01, 04–07, 12, 14, 19, 20, 24, 25, 26N, 27, 32, 33, 34 and 35); group II: HLA‐B*15 (02, 08, 11, 15, 28 and 30); group III: HLA‐B*1503/4802; group IV: HLA‐B*1521. Groups I and II occurred frequently (allele frequency = 8.0 and 2.5%), and thus we optimized the polymerase chain reaction–single‐stranded conformation polymorphism (PCR‐SSCP) method to identify HLA‐B*15 subtypes of groups I and II. Eighty samples of DNA carrying HLA‐B*15 from 300 healthy unrelated individuals were tested. B*1502 (52.5%) and B*1525 (13.8%) were the most common subtypes found in NET. They also showed strong linkage disequilibrium with HLA‐Cw and heterogeneity of HLA‐A, DR, DQ haplotypes. Although limited conclusions can be drawn from this study because of the small number of DNA references used, the baseline data will be useful in the selection of common HLA‐B*15 alleles when subtyping for unrelated donor transplantations.
Determination of exchangeable potassium in soil using ion‐selective electrodes in soil suspensions
Authors: Wang J. J. , Scott A. D. 
Published: December 2004

SummaryMethods of determining exchangeable K+of soil by mixing extracting solutions and analysing the soil suspension with ion‐selective electrodes were developed and evaluated on 30 samples of soils. From preliminary comparisons of the K+extracted by BaCl2and NH4OAc solutions and by batch and leaching treatments of soils, we established that suspensions of 5 g soil in 100 ml 0.5 mBaCl2and single batch treatments of 1 h should be used. The exchangeable K+was determined with a K‐selective, valinomycin‐based PVC membrane electrode and electrochemical cells that did or did not include a liquid junction (the reference electrode being a double‐junction reference electrode assembly with a 10 mLiOAc salt bridge solution or a Cl‐selective electrode, respectively). The Ba‐exchangeable K+values were sensibly the same whether a liquid junction was involved or not, a result that can be attributed to the beneficial effects of the salt bridge and the ionic strength of the extractant. Comparisons of these Ba‐exchangeable results with those obtained by various combinations of batch or leaching treatments, BaCl2or NH4OAc extractants and filtrate analysis by the ion‐selective electrode method or atomic absorption spectrometry showed they were all highly correlated (r≥ 0.996). The selectivity of the K+‐selective electrode (kpotKNH4 = 0.004) significantly reduced the interference from indigenous soil NH4+in the BaCl2suspensions. Overall, the results show potentiometric measurements of K+in soil suspensions can provide a simple, rapid, and reliable means of determining exchangeable K+in soils.
Non‐linearity and error in modelling soil processes
Authors: Addiscott T. M. , Tuck G. 
Published: December 2004

SummaryError in models and their inputs can be propagated to outputs. This is important for modelling soil processes because soil properties used as parameters commonly contain error in the statistical sense, that is, variation. Model error can be assessed by validation procedures, but tests are needed for the propagation of (statistical) error from input to output. Input error interacts with non‐linearity in the model such that it contributes to the mean of the output as well as its error. This can lead to seriously incorrect results if input error is ignored when a non‐linear model is used, as is demonstrated for the Arrhenius equation. Tests for non‐linearity and error propagation are suggested. The simplest test for non‐linearity is a graph of the output against the input. This can be supplemented if necessary by testing whether the mean of the output changes as the standard deviation of the input increases. The tests for error propagation examine whether error is suppressed or exaggerated as it is propagated through the model and whether changes in the error in one input influence the propagation of another. Applying these tests to a leaching model with rate and capacity parameters showed differences between the parameters, which emphasized that statements about non‐linearity must be for specific inputs and outputs. In particular, simulations of mean annual concentrations of solute in drainage and concentrations on individual days differed greatly in the amount of non‐linearity revealed and in the way error was propagated. This result is interpreted in terms of decoherence.
Soil properties affecting solid–liquid distribution of As(V) in soils
Authors: Brouwere K. De , Smolders E. , Merckx R. 
Published: December 2004

SummaryThe prediction of the mobility of arsenic (As) is crucial for predicting risks in soils contaminated with As. The objective of this study is to predict the distribution of As between solid and solution in soils based on soil properties and the fraction of As in soil that is reversibly adsorbed. We studied adsorption of As(V) in suspensions at radiotrace concentrations for 30 uncontaminated soils (pH 4.4–6.6). The solid–liquid distribution coefficient of As (Kd) varied from 14 to 4430 l kg−1. The logarithm of the concentration of oxalate‐extractable Fe explained 63% of the variation in log Kd; by introducing the logarithm of the concentration of oxalate‐extractable P in the regression model, 85% of the variation in log Kd is explained. Double labelling experiments with 73As(V) and 32P(V) showed that the As to P adsorption selectivity coefficient decreased from 3.1 to 0.2 with increasing degree of P saturation of the amorphous oxides. The addition of As(V) (0–6 mmol kg−1) reduced the Kd of 73As up to 17‐fold, whereas corresponding additions of P(V) had smaller effects. These studies suggest that As(V) is adsorbed to amorphous oxides in soils and that sites of adsorption vary in their selectivity in respect of As and P. The concentration of isotopically exchangeable As in 27 contaminated soils (total As 13–1080 mg kg−1) was between 1.2 and 19% (mean 8.2%) of its total concentration, illustrating that a major fraction of As is fixed. We propose a two‐site model of competitive As(V)–P(V) sorption in which amorphous Fe and Al oxides represent the site capacity and the isotopically exchangeable As represents the adsorbed phase. This model is fitted to 73As adsorption data of uncontaminated soils and explains 69% of the variation of log Kd in these soils. The log Kd in contaminated soils predicted using this two‐site model correlated well with the observed log Kd (r = 0.75). We conclude that solubility of As is related to the available binding sites on amorphous oxides and to the fraction of As that is fixed.
An anion resin membrane technique to overcome detection limits of isotopically exchanged P in P‐sorbing soils
Authors: Maertens E. , Thijs A. , Smolders E. , Degryse F. , Cong P. T. , Merckx R. 
Published: December 2004

SummaryIsotopically exchanged phosphorus is difficult to determine in soils that strongly sorb P (so that there is little P in solution) and in soils with large concentrations of colloidal P in soil suspensions. A method is proposed in which anion exchange membranes (AEM) are added to the soil suspension after an initial period of isotopic exchange with 32P‐labelled phosphate ions. Isotopically exchanged P, termed EAEM, is calculated from the ratio of labelled phosphate ions to the total phosphate ions on the membrane. The EAEM was compared with the E value measured in an aqueous soil extract (EWater extract) for 14 soils with different degrees of P sorption. The two methods gave similar results in soils with large P concentrations in an aqueous soil extract. However, EWater extract values significantly exceeded the EAEM values by up to 18‐fold when soluble P was near the determination limit (0.008 mg P l−1). In a second experiment, two Ferralsols received further P from inorganic and plant sources and were incubated for 7 days. Treatment effects on labile P were erroneous as detected by the EWater extract but were significant as detected with the AEM method. Third, EAEM values were followed in a Lixisol and a Ferralsol which received labelled phosphate ions with carrier just before the beginning of a 23‐day incubation. The approximate recovery of added inorganic P in the EAEM value suggested that this method adequately samples labile P in P‐sorbing soils. All these results showed that errors in the determination of E values for soils with very small concentrations of P in the soil solution are reduced using the proposed method.
Classification, assessment and trophic reconstruction of Danish lakes using chironomids
Authors: Brodersen Klaus Peter , Lindegaard Claus 
Published: December 2004

1. Surface‐sediment assemblages of subfossil chironomid head capsules from fifty‐four primarily shallow and nutrient‐rich Danish lakes were analysed using multivariate numerical techniques. The species data, comprising forty‐one chironomid taxa, were compared to environmental monitoring data in order to establish a relationship between chironomid faunal composition and lake trophic state.2. The subfossil assemblages were compared to the chironomid bathymetric distributions along transects from four lakes. Correspondence analysis and similarity coefficients showed that the subfossil assemblages, sampled in the lake centre, reflect the chironomid communities in the littoral at a depth of 2–7 m.3. Two‐way indicator species analysis (TWINSPAN) was used to classify the Danish lakes into five groups defined by trophic state, lake depth and pH. Eighteen chironomid taxa showed significant differences in abundance among the five groups. Canonical correspondence analysis (CCA) showed the chlorophyll a concentration ([Chl a]) and Secchi depth to be the variables best correlated to the faunal data, and fourteen taxa were significantly correlated to [Chl a].4. The strong correlation between chironomid data and the ln‐transformed ([Chl a]) was used to create a weighted averaging (WA) model to infer lake trophic state. Several models were tested by cross validation (leave‐one‐out jack‐knifing), and a simple WA model using inverse de‐shrinking had a RMSEPjack of 0.65 (ln units) and a r2jack of 0.67.5. The results can be used in the assessment and reconstruction of lake trophic state for long‐term monitoring and palaeoecological investigations of shallow, temperate lakes in the mesotrophic to hypertrophic nutrient range.
Implications of varying pipe model relationships on Scots Pine growth in different climates
Authors: BERNINGER F. , NIKINMAA E. 
Published: December 2004

1. The process‐based model SIMFORG, based on the pipe theory, was parameterized for Scots Pine at six locations along a north–south gradient in Europe. The ratio of foliage mass to stem cross‐sectional area was changed as a function of potential evapotranspiration as proposed by Berninger et al. (1995). 2. Allocation to the stem differed between the locations and affected consequently the stemwood production. Variation in the net primary production and differences in the pipe model parameters were responsible for these differences. There was good agreement between measured and simulated data. 3. Increase in primary production, as predicted by climate‐change senarios, increased allocation to the stem. However, the results were sensitive to changes in the foliage mass to stem sapwood cross‐sectional area ratio. The changes in allocation were higher in the north than in the south.
Carbon and water fluxes in a calcareous grassland under elevated CO2
Authors: STOCKER R. , LEADLEY P. W. , KÖRNER CH. 
Published: December 2004

1. As part of a long‐term study of the effects of elevated CO2 on biodiversity and ecosystem function in a calcareous grassland, we measured ecosystem carbon dioxide and water‐vapour fluxes over 24‐h periods during the 1994 and 1995 growing seasons. Data were used to derive CO2 and H2O gas‐exchange response functions to quantum flux density (QFD). 2. The relative increase in net ecosystem CO2 flux (NEC) owing to CO2 enrichment increased as QFD rose. Daytime NEC at high QFD under elevated CO2 increased by 25% to 60%, with the greatest increases in the spring and after mowing in June when above‐ground biomass was lowest. There was much less stimulation of NEC in early June and again in October when the canopy was fully developed. Night‐time NEC was not significantly altered under elevated CO2. 3. Short‐term reversal of CO2 concentrations between treatments after two seasons of CO2 exposure provided evidence for a 50% downward adjustment of NEC expressed per unit above‐ground plant dry weight. However, when expressed on a land area basis, this difference disappeared because of a c. 20% increase in above‐ground biomass under elevated CO2. 4. Ecosystem evapotranspiration (ET) was not significantly altered by elevated CO2 when averaged over all measurement dates and positions. However, ET was reduced 3–18% at high QFD in plots at the top of the slope at our study site. In summary, CO2 enrichment resulted in a large stimulation of ecosystem CO2 capture, especially during periods of a large demand of carbon in relationship to its supply, and resulted in a relatively small and variable effect on ecosystem water consumption.
3D imaging of a reservoir analogue in point bar deposits in the Ferron Sandstone, Utah, using ground‐penetrating radar
Authors: Zeng Xiaoxian , McMechan George A. , Bhattacharya Janok P. , Aiken Carlos L.V. , Xu Xueming , Hammon William S. , Corbeanu Rucsandra M. 
Published: December 2004

ABSTRACTMost existing reservoir models are based on 2D outcrop studies; 3D aspects are inferred from correlation between wells, and so are inadequately constrained for reservoir simulations. To overcome these deficiencies, we have initiated a multidimensional characterization of reservoir analogues in the Cretaceous Ferron Sandstone in Utah. Detailed sedimentary facies maps of cliff faces define the geometry and distribution of reservoir flow units, barriers and baffles at the outcrop. High‐resolution 2D and 3D ground‐penetrating radar (GPR) images extend these reservoir characteristics into 3D to allow the development of realistic 3D reservoir models. Models use geometric information from mapping and the GPR data, combined with petrophysical data from surface and cliff‐face outcrops, and laboratory analyses of outcrop and core samples.The site of the field work is Corbula Gulch, on the western flank of the San Rafael Swell, in east‐central Utah. The outcrop consists of an 8–17 m thick sandstone body which contains various sedimentary structures, such as cross‐bedding, inclined stratification and erosional surfaces, which range in scale from less than a metre to hundreds of metres. 3D depth migration of the common‐offset GPR data produces data volumes within which the inclined surfaces and erosional surfaces are visible. Correlation between fluid permeability, clay content, instantaneous frequency and instantaneous amplitude of the GPR data provides estimates of the 3D distribution of fluid permeability and clay content.
Early menopause in women with Down's syndrome
Authors: Schupf N. , Zigman W. , Kapell D. , Lee J. H. , Kline J. , Levin B. 
Published: December 2004

AbstractWe used the AAMR's Adaptive Behavior Scale to ascertain current menstrual status in a population‐based sample of 157 women with Down's syndrome (DS) and 187 women with other intellectual disability, all 40 years of age or older. The age‐adjusted likelihood of menopause was twice as high in women with DS syndrome as in women with other intellectual disability (OR=2.3; 95% Cl= 1.1–4,9). Treated thyroid conditions did not influence menstrual status and did not modify the relationship between DS and menstrual status. These findings support the hypothesis that women with DS experience menopause at an earlier age and that this may be associated with accelerated aging.
Hypofibrinolysis in the insulin resistance syndrome: implication in cardiovascular diseases
Authors: Mavri A. , Alessi M.‐C. , Juhan‐Vague I. 
Published: December 2004

Abstract.Insulin resistance syndrome (IRS) is associated with increased cardiovascular morbidity and mortality. IRS is becoming one of the major health problems as its prevalence grows rapidly. Accelerated atherothrombotic process in the IRS is attributed to metabolic abnormalities, inflammation and to impaired fibrinolysis due to increased plasma plasminogen activator inhibitor type 1 (PAI‐1) levels. Proinflammatory cytokines may have an important role in PAI‐1 overexpression, particularly in the adipose tissue. Studies in genetically modified mice indicate that PAI‐1 might be involved in the aetiopathogenesis of obesity. Modifying PAI‐1 expression by PAI‐1 inhibitors may open a new field of research and may reveal the true role of PAI‐1 in atherosclerotic and insulin resistance processes.