bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tourmaline breakdown in the migmatite zone of the Ryoke metamorphic belt, SW Japan
Authors: Kawakami T. 
Published: March 2003

AbstractA sharp line delimitating the distribution of tourmaline (termed as a ‘tourmaline‐out isograd’) is defined in the migmatite zone of the Ryoke metamorphic belt, Japan. The trend of the tourmaline‐out isograd closely matches that of the isograds formed through the regional metamorphism, suggesting that it represents the breakdown front of tourmaline during regional metamorphism. This is confirmed by the presence of the reaction textures of tourmaline to sillimanite and cordierite near the tourmaline‐out isograd. The breakdown of tourmaline would release boron into associated melts or fluids and be an important factor in controlling the behaviour of boron in tourmaline‐bearing high‐temperature metamorphic rocks.Near the tourmaline‐out isograd, large tourmaline crystals occur in the centre of interboudin partitions containing leucosome. In the melanosome of the intervening matrix, reaction textures involving tourmaline are locally observed. These observations imply that tourmaline breakdown is related to a melting reaction and that the boron in the leucosome is derived from the breakdown of tourmaline in the melanosome during prograde metamorphism.Boron released by tourmaline breakdown lowers both the solidus temperature of the rock and the viscosity of any associated melt. Considering that the tourmaline‐out isograd lies close to the schist–migmatite boundary, these effects might have enhanced melt generation and segregation in the migmatite zone of the Ryoke belt.The evidence for the breakdown of tourmaline and the almost complete absence of any borosilicates throughout the migmatite zone suggest that boron was effectively removed from this region by the movement of melt and/or fluid. This implies that the tourmaline‐out isograd can reflect a significant amount of mass transfer in the anatectic zones.
Retrograde metamorphism of eclogite in the southern Appalachian Mountains, U.S.A.–A case involving seamount subduction?
Authors: Abbott R. N. , Greenwood J. P. 
Published: March 2003

AbstractThis work supports a growing body of evidence that the Ashe Metamorphic Suite (AMS) of the eastern Blue Ridge province in North Carolina has an ensimatic origin and is part of a subduction‐related accretionary mélange, marking the Taconic suture between the North American craton and the Inner Piedmont. In a palinspastic reconstruction, the thrust fault at the base of the AMS appears to have intercepted the greatest depths (i.e. highest‐P metamorphic rocks) beneath parts of the AMS now exposed adjacent to the Grandfather Mountain window. The greatest volume of mafic rock is found in these same areas. We suggest that the nascent, subduction‐related, basal thrust fault was deflected downward by an obstacle in the form of an isolated, mafic volcanic edifice on the oceanic crust–a sea mount.Pelitic and mafic rocks dominate the AMS. North of the Grandfather Mountain window, retrograded eclogite occurs in the amphibolite near the base of the AMS. Textures and mineralogy indicate that an original eclogite assemblage was subjected to the following sequence of parageneses:(a) Eclogite(I) facies: omphacite+garnet+quartz,(b) Eclogite(II) facies: omphacite+garnet+epidote+quartz,(c) Symplectic (diopside+plagioclase)+garnet+epidote+quartz,(d) Amphibolite facies: (diopside+plagioclase)+garnet+epidote+hornblende+quartz,(e) Amphibolite facies: plagioclase+garnet+epidote+hornblende+quartz. P–T conditions, estimated from geothermobarometry applied to relevant mineral compositions, are c.720 °C and c.16 kbar for (b) eclogite(II) facies; c.655 °C and c.8.5 kbar for (e) amphibolite facies.
Reaction pathways and reaction progress for the smectite‐to‐chlorite transformation: evidence from hydrothermally altered metabasites
Authors: Robinson D. , Schmidt S. Th. , De Zamora A. Santana 
Published: March 2003

AbstractThe transformation from smectite to chlorite has been interpreted as involving either a disequilibrium chlorite/smectite mixed‐layering sequence, or an equilibrated discontinuous sequence involving smectite–corrensite–chlorite. Here, analysis of the smectite to chlorite transition in different geothermal systems leads us to propose that the transformation proceeds via three contrasting reaction pathways involving (i) a continuous mixed‐layer chlorite/smectite series; (ii) a discontinuous smectite–corrensite–chlorite series and (iii) a direct smectite to chlorite transition. Such contrasting pathways are not in accord with an equilibrium mineral reaction series, suggesting that these pathways record kinetically controlled reaction progress. In the geothermal systems reviewed the style of reaction pathway and degree of reaction progress is closely correlated with intensity of recrystallization, and not to differences in thermal gradients or clay grain size. This suggests a kinetic effect linked to variation in fluid/rock ratios and/or a contrast between advective or diffusive fluid transport. The mode of fluid transport provides a means by which the rates of dissolution/nucleation/growth can control the reaction style and the reaction progress of the smectite to chlorite transition. Slow rates of growth are linked to the first reaction pathway involving mixed‐layering, while increasing rates of growth, relative to nucleation, promote the generation of more ordered structures and ultimately lead to the direct smectite to chlorite transition, representative of the third pathway.
The use of endogenous nitrogen for microbial crude protein synthesis in the rumen of growing bulls
Authors: Kluth H. , Gabel M. , Voigt J. , Schönhusen U. 
Published: March 2003

SummaryThe objective of this study was to quantify endogenous nitrogen (N) recycled for microbial protein synthesis in the rumen. Four growing bulls (Schwarzbuntes Milchrind; bodyweight: 240–310 kg) with duodenal T‐shaped cannulas were fed diets containing four levels of crude protein content (200, 156, 102 and 63 g/kg dry matter, respectively). The diets were based on wheat, barley, tapioca meal, soybean extracted meal, dried beet pulp, meadow hay and straw. The diets had an energy level of 11.1, 10.9, 10.2 and 9.6 MJ metabolizable energy/kg dry matter. Faeces and urine were collected in four 7‐day balance periods. Duodenal flow rate was estimated by TiO2, pelleted with grain, as a marker. The relationship between urine N excretion, the amount of microbial N reaching the duodenum, ruminal N balance and N retention were examined and the amount of endogenous N available for microbial protein synthesis without negative effects on the N retention was determined. It can be concluded that up to 16% of the microbial N supply could be covered by recycled endogenous N, but N retention should not be decreased by more than 1.5 residual standard deviations of maximal N retention.
Eukaryotic features of the Xanthomonas type III effector AvrBs3: protein domains involved in transcriptional activation and the interaction with nuclear import receptors from pepper
Authors: Szurek Boris , Marois Eric , Bonas Ulla , Van den Ackerveken Guido 
Published: March 2003

SummaryThe AvrBs3 protein of the phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria is targeted to host‐plant cells by the bacterial Hrp type III secretion system. In pepper plants containing the Bs3 resistance gene, AvrBs3 induces the hypersensitive response (HR). AvrBs3 recognition is thought to occur in the plant cell nucleus as HR induction is dependent on nuclear localization signals (NLSs) and an acidic transcription activation domain (AAD). In a search for AvrBs3‐interacting pepper proteins using the yeast two‐hybrid system, we have isolated eight different classes of cDNA inserts including two genes for importin α proteins. Importin α is part of the nuclear import machinery and interacts with AvrBs3 through an NLS in the carboxy‐terminus of the protein, both in yeast and in vitro. The mechanism of AvrBs3 recognition was further studied by analysis of the C‐terminal AAD. This putative transcription‐activation domain was shown to be required for AvrBs3 HR‐inducing activity, and could be functionally replaced with the VP16 AAD from the Herpes simplex virus. Our data support the model in which the AvrBs3 effector localizes to the nucleus, where the Bs3‐mediated surveillance system of resistant plants detects AvrBs3 through its interference with host gene transcription.
Fetal intracranial hemorrhage: is minor maternal trauma a possible pathogenetic factor?
Authors: Strigini F. A. L. , Cioni G. , Canapicchi R. , Nardini V. , Capriello P. , Carmignani A. 
Published: March 2003

AbstractObjectiveThe occurrence of fetal intracranial hemorrhage before labor has been repeatedly observed. The aim of this study was to evaluate the sonographic appearance of fetal intracranial hemorrhage in relation to its location. Possible causative factors were also evaluated.DesignFive consecutive cases of fetal intracranial hemorrhage were identified at a single ultrasound unit between 1996 and 1999. In utero magnetic resonance imaging was also performed in four of these cases. Autopsy was performed after pregnancy termination or intrauterine fetal death (one case of each), and neurological follow‐up was initiated in the three surviving infants.ResultsHydrocephaly was the predominant sonographic finding associated with intraventricular or subependymal hemorrhage; sonography provided the correct diagnosis in the former (two cases), whereas magnetic resonance imaging was necessary in the latter. Massive intraparenchymal hemorrhage was depicted as an irregular echoic mass, whereas extradural hemorrhage had a cystic appearance. History of minor maternal physical trauma without maternal or placental injury was elicited in all cases. Ultrasound examinations performed before or shortly after the trauma were available in all cases and showed normal fetal anatomy.ConclusionsThe sonographic appearance of fetal intracranial hemorrhage is variable, depending on its location. Even though sonography detected an intracranial anomaly in all cases, magnetic resonance imaging was necessary to establish the hemorrhagic nature of isolated subependymal and extradural hemorrhage. The similarity of histories involving minor maternal physical trauma in all cases, together with the absence of any known factor predisposing to fetal hemorrhage, may suggest that trauma is at least a contributing factor to the pathogenesis of fetal intracranial hemorrhage. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Effects of malaria infection on vitellogenesis in Anopheles gambiae during two gonotrophic cycles
Authors: Ahmed A. M. , Maingon R. , Romans P. , Hurd H. 
Published: March 2003

AbstractWe report changes in the abundance of vitellogenin (Vg) mRNA, and concentration of haemolymph Vg and ovarian vitellin (Vn) in Anopheles gambiae following infection with Plasmodium yoelii nigeriensis. A parasite‐induced reduction in Vg mRNA abundance was first detected 24 h after feeding on an infective blood meal, when ookinetes were invading the midgut. During a second gonotrophic cycle post‐infection, developing oocysts reduced Vg mRNA abundance by up to 33% and the effect was detected from 2 h post blood meal. Concentrations of Vg were initially reduced by infection during the second cycle, as predicted from Vg mRNA measurements. However, after 24 h, excess Vg had accumulated in the haemolymph. This accumulation may be due to impaired uptake, since ovarian vitellin accumulation was significantly decreased by infection during both gonotrophic cycles.
Genetic diversity of heavy metal‐tolerant populations inSilene paradoxaL. (Caryophyllaceae): a chloroplast microsatellite analysis
Authors: Mengoni A. , Barabesi C. , Gonnelli C. , Galardi F. , Gabbrielli R. , Bazzicalupo M. 
Published: March 2003

AbstractEight populations ofSilene paradoxaL. (Caryophyllaceae) growing in copper mine deposits, in serpentine outcrops or in uncontaminated soil in central Italy were studied. Genetic diversity was estimated using five polymorphic chloroplast microsatellite loci (cpSSR), identifying 27 different chloroplast haplotypes. The effective number of alleles, the haplotypic diversity and a stepwise mutational model‐based parameter (DSH2) were computed. The effective number of alleles observed within populations from copper mine deposits was 20% that of the serpentine neighbouring populations, suggesting the occurrence of a founder effect. Moreover, 13 of the 27 different haplotypes scored were exclusive to only one population, indicating genetic isolation for all tolerant populations. Even the copper‐tolerant populations appeared to have evolved independently. Finally, analysis of molecular variance (amova) of the cpSSR markers gave statistical significance to the grouping of populations according to their geographical location. This study demonstrates that cpSSR markers could be a useful complementary tool to isoenzymes or random amplified polymorphic DNA markers for elucidating the pattern of genetic differentiation in heavy metal‐tolerant populations.
‘Neighbourhood’ size, dispersal and density estimates in the prickly forest skink (Gnypetoscincus queenslandiae) using individual genetic and demographic methods
Authors: Sumner J. , Rousset F. , Estoup A. , Moritz C. 
Published: March 2003

AbstractDispersal, or the amount of dispersion between an individual’s birthplace and that of its offspring, is of great importance in population biology, behavioural ecology and conservation, however, obtaining direct estimates from field data on natural populations can be problematic. The prickly forest skink,Gnypetoscincus queenslandiae, is a rainforest endemic skink from the wet tropics of Australia. Because of its log‐dwelling habits and lack of definite nesting sites, a demographic estimate of dispersal distance is difficult to obtain. Neighbourhood size, defined as 4πDσ2(whereDis the population density and σ2the mean axial squared parent–offspring dispersal rate), dispersal and density were estimated directly and indirectly for this species using mark–recapture and microsatellite data, respectively, on lizards captured at a local geographical scale of 3 ha. Mark–recapture data gave a dispersal rate of 843 m2/generation (assuming a generation time of 6.5 years), a time‐scaled density of 13 635 individuals * generation/km2and, hence, a neighbourhood size of 144 individuals. A genetic method based on the multilocus (10 loci) microsatellite genotypes of individuals and their geographical location indicated that there is a significant isolation by distance pattern, and gave a neighbourhood size of 69 individuals, with a 95% confidence interval between 48 and 184. This translates into a dispersal rate of 404 m2/generation when using the mark–recapture density estimation, or an estimate of time‐scaled population density of 6520 individuals * generation/km2when using the mark–recapture dispersal rate estimate. The relationship between the two categories of neighbourhood size, dispersal and density estimates and reasons for any disparities are discussed.
The population genetics of host specificity: genetic differentiation in dove lice (Insecta: Phthiraptera)
Authors: Johnson Kevin P , Williams Barry L , Drown Devin M , Adams Richard J , Clayton Dale H 
Published: March 2003

AbstractSome species of parasites occur on a wide range of hosts while others are restricted to one or a few host species. The host specificity of a parasite species is determined, in part, by its ability to disperse between host species. Dispersal limitations can be studied by exploring the genetic structure of parasite populations both within a single species of host and across multiple host species. In this study we examined the genetic structure in the mitochondrial cytochrome oxidase I (COI) gene of two genera of lice (Insecta: Phthiraptera) occurring on multiple sympatric species of doves in southern North and Central America. One genus,Columbicola, is generally less host‐specific than the other,Physconelloides. For both genera we identified substantial genetic differentiation between populations of conspecific lice on different host species, generally 10–20% sequence divergence. This level of divergence is in the range of that often observed between species of these two genera. We used nested clade analysis to explore fine scale genetic structure within species of these feather lice. We found that species ofPhysconelloidesexhibited more genetic structure, both among hosts and among geographical localities, than did species ofColumbicola. In many cases, single haplotypes within species ofColumbicolaare distributed on multiple host species. Thus, the population genetic structure of species ofPhysconelloidesreveals evidence of geographical differentiation on top of high host species specificity. Underlying differences in dispersal biology probably explain the differences in population genetic structure that we observed betweenColumbicolaandPhysconelloides.
Microarrays in ecology and evolution: a preview
Authors: Gibson Greg 
Published: March 2003

AbstractMicroarray technology provides a new tool with which molecular ecologists and evolutionary biologists can survey genome‐wide patterns of gene expression within and among species. New analytical approaches based on analysis of variance will allow quantification of the contributions of among individual variation, genotype, sex, microenvironment, population structure, and geography to variation in gene expression. Applications of this methodology are reviewed in relation to studies of mechanisms of adaptation and divergence; delineation of developmental and physiological pathways and networks; characterization of quantitative genetic parameters at the level of transcription (‘quantitative genomics’); molecular dissection of parasitism and symbiosis; and studies of the diversification of gene content. Establishment of microarray resources is neither prohibitively expensive nor technologically demanding, and a commitment to development of gene expression profiling methods for nonmodel organisms could have a tremendous impact on molecular and genetic research at the interface of organismal and population biology.
Glucose screening test results in first and early third trimester of pregnancy: Is there any correlation?
Authors: Bhattacharya Sudhindra Mohan 
Published: March 2003

AbstractObjective: This study aims to find correlation between glucose screening test (GST) results done in the first trimester and again in the early third trimester of pregnancy.Methods: Analysis of the records of 458 cases of pregnant women (non‐diabetic in early pregnancy as detected by glucose screening test and glucose tolerance test) between 22 and 35 years of age with a body mass index of less than 25 kg/m2 was done. These women underwent GST in the first trimester (GST‐1) and again in the early third trimester (GST‐2). When the GST‐2 was 140 mg% or above, a standard ‘3 hour glucose tolerance test’ was done (GT TEST) with 100 g of glucose. The GST was done by measuring the plasma glucose level 1 hour after taking 50 g of glucose, irrespective of food intake.Results: A substantial correlation between the two groups of measurements was found. Based on the available data, a GST‐1 value of 99 mg% or less was seldom associated with GST‐2 value of 140 mg% or more (GT TEST was positive in none). It was observed that 100% of cases with GST‐1 value of 140 mg% or more had GST‐2 of 140 mg% or more. Out of those having GST‐2 value of 140 mg% or more, 72% had GT TEST positive. In the intermediate group (i.e. those patients having GST‐1 value of 100 mg% − 139 mg%), 51.7% had GST‐2 values of 140 mg% or more. Out of these 51.7% cases, only 23% cases turned out to be GT TEST positive. The correlation coefficients (CC) worked out to be 0.38 (substantial correlation for 0.20 < CC < 0.70).Conclusion: From the observations stated above, it is concluded that for women with GST‐1 of 99 mg% or less, a GST‐2 is not necessary. For those having GST‐1 of 140 mg% or more, a GT TEST is absolutely necessary instead of repeating the screening test again in the third trimester. But it is in the intermediate group (i.e. with GST‐1 value of 100 mg%–139 mg%) where the glucose screening test should be repeated in the early third trimester and GT TEST as and when necessary.
Involvement of peroxynitrite in LPS‐induced apoptosis of trophoblasts
Authors: Asagiri Kazuo , Nakatsuka Mikiya , Konishi Hideki , Noguchi Soichi , Takata Masayo , Habara Toshihiro , Kudo Takafumi 
Published: March 2003

AbstractObjective:  To examine whether or not peroxynitrite was involved in trophoblastic apoptosis induced by a bacterial endotoxin, lipopolysaccharide (LPS).Methods:  Levels of nitrite/nitrate, stable metabolites of nitric oxide (NO), in culture medium of trophoblasts, were determined using Griess reagents. Trophoblastic apoptosis was identified morphologically and confirmed using in situ nick end labeling technique. The amount of nitrotyrosine, a footprint of peroxynitrite, was quantified by dot blotting. Statistical significance was determined by anova.Results:  Treatment of trophoblasts with LPS leads to apoptosis accompanied by formation of NO and nitrotyrosine. Aminoguanidine, an inhibitor of NO synthase (NOS), reduced peroxynitrite formation and prevented apoptosis. Scavengers of peroxynitrite also prevented apoptosis in this culture model.Conclusion:  Peroxynitrite was involved in trophoblastic apoptosis induced by LPS. Peroxynitrite scavengers or inhibitors of NOS may thus be candidate therapeutic agents for infectious diseases, which is associated with overproduction of NO and peroxynitrite.
Non‐invasive cutaneous cardiovascular dynamics (CVD) as a predictor of preterm delivery: A pilot study
Authors: Ogunyemi Dotun , Vargas Noemi , Fukushima Teiichiro , Hon Edward 
Published: March 2003

AbstractAim:  To assess the clinical value of cardiovascular dynamics (CVD) pattern of ‘positive cycling’ in predicting true preterm labor.Methods:  Patients with a clinical diagnosis of preterm labor had CVD measurement with a non‐invasive miniature pressure transducer applied to the fingertip concomitantly with uterine activity monitoring. Based on previous work by our group, the rapid ejection time (RET) reflects arterial compliance; an elevated RET is suggestive of vasoconstriction. Positive cycling is present when the RET shows elevation with uterine contractions and negative cycling is present when there are no changes in the RET with uterine contractions.Results:  Twenty‐seven women had negative CVD cycling and nine had positive CVD cycling. There was no difference between the two groups in initial gestational age, cervical effacement or cervical dilation at testing. However, the mean interval from testing to delivery was 1.56 (SEM ± 0.29) days for positive cycling and 39 days (± 5.25) for negative cycling (P < 0.001).Conclusion:  Non‐invasive cardiovascular patterns of positive cycling appear predictive of preterm delivery.