bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil inorganic carbon storage pattern in China
Authors: MI NA , WANG SHAOQIANG , LIU JIYUAN , YU GUIRUI , ZHANG WENJUAN , JOBBÁGY ESTEBAN
Published: May 2008

Soils with pedogenic carbonate cover about 30% (3.44 × 106 km2) of China, mainly across its arid and semiarid regions in the Northwest. Based on the second national soil survey (1979–1992), total soil inorganic carbon (SIC) storage in China was estimated to be 53.3±6.3 PgC (1 Pg=1015 g) to the depth investigated to 2 m. Soil inorganic carbon storages were 4.6, 10.6, 11.1, and 20.8 Pg for the depth ranges of 0–0.1, 0.1–0.3, 0.3–0.5, and 0.5–1 m, respectively. Stocks for 0.1, 0.3, 0.5, and 1 m of depth accounted for 8.7%, 28.7%, 49.6%, and 88.9% of total SIC, respectively. In contrast with soil organic carbon (SOC) storage, which is highest under 500–800 mm yr−1 of mean precipitation, SIC storage peaks where mean precipitation is <400 mm yr−1. The amount and vertical distribution of SIC was related to climate and land cover type. Content of SIC in each incremental horizon was positively related with mean annual temperature and negatively related with mean annual precipitation, with the magnitude of SIC content across land cover types showing the following order: desert, grassland >shrubland, cropland >marsh, forest, meadow. Densities of SIC increased generally with depth in all ecosystem types with the exception of deserts and marshes where it peaked in intermediate layers (0.1–0.3 m for first and 0.3–0.5 m for latter). Being an abundant component of soil carbon stocks in China, SIC dynamics and the process involved in its accumulation or loss from soils require a better understanding.
Spatial variability and major controlling factors of CO2 sink strength in Asian terrestrial ecosystems: evidence from eddy covariance data
Authors: KATO TOMOMICHI , TANG YANHONG
Published: May 2008

Asian terrestrial ecosystems cover an extensive area characterized by a large variety in climates and ecosystem properties. The observations of ecosystem CO2 flux in this area are increasing both in duration and spatial density, but no synthesis has yet been conducted. We surveyed CO2 flux observation data obtained by eddy covariance methods at 49 sites in terrestrial Asia. The measurements at most sites (44 of 49) began after 2000. The net ecosystem uptake of CO2 (NEE) varied greatly among sites and years and averaged −132.6±73.7, −250.1±206.1, and −180.1±361.7 g C m−2 yr−1, in boreal, temperate, and tropical Asia, respectively, and the coefficient of variation among sites increased from boreal to tropical Asia. The site‐averaged annual NEE was correlated linearly with the mean annual temperature (Tair) and also correlated logarithmically with the precipitation. Multiple regression analysis and stepwise analysis indicated that photosynthetic active radiation (PAR) and Tair were the most significant predictors of the annual NEE. The study results suggest that Asian terrestrial ecosystems are currently significant net CO2 sinks and that the sink strength is largely controlled by temperature, moisture, and light conditions.
Changing land use reduces soil CH4 uptake by altering biomass and activity but not composition of high‐affinity methanotrophs
Authors: MENYAILO OLEG V. , HUNGATE BRUCE A. , ABRAHAM WOLF‐RAINER , CONRAD RALF
Published: May 2008

Forest ecosystems assimilate more CO2 from the atmosphere and store more carbon in woody biomass than most nonforest ecosystems, indicating strong potential for afforestation to serve as a carbon management tool. However, converting grasslands to forests could affect ecosystem–atmosphere exchanges of other greenhouse gases, such as nitrous oxide and methane (CH4), effects that are rarely considered. Here, we show that afforestation on a well‐aerated grassland in Siberia reduces soil CH4 uptake by a factor of 3 after 35 years of tree growth. The decline in CH4 oxidation was observed both in the field and in laboratory incubation studies under controlled environmental conditions, suggesting that not only physical but also biological factors are responsible for the observed effect. Using incubation experiments with 13CH4 and tracking 13C incorporation into bacterial phospholipid fatty acid (PLFA), we found that, at low CH4 concentrations, most of the 13C was incorporated into only two PLFAs, 18 : 1ω7 and 16 : 0. High CH4 concentration increased total 13C incorporation and the number of PLFA peaks that became labeled, suggesting that the microbial assemblage oxidizing CH4 shifts with ambient CH4 concentration. Forests and grasslands exhibited similar labeling profiles for the high‐affinity methanotrophs, suggesting that largely the same general groups of methanotrophs were active in both ecosystems. Both PLFA concentration and labeling patterns indicate a threefold decline in the biomass of active methanotrophs due to afforestation, but little change in the methanotroph community. Because the grassland consumed CH4 at a rate five times higher than forest soils under laboratory conditions, we concluded that not only biomass but also cell‐specific activity was higher in grassland than in afforested plots. While the decline in biomass of active methanotrophs can be explained by site preparation (plowing), inorganic N (especially NH4+) could be responsible for the change in cell‐specific activity. Overall, the negative effect of afforestation of upland grassland on soil CH4 uptake can be largely explained by the reduction in biomass and to a lesser extent by reduced cell‐specific activity of CH4‐oxidizing bacteria.
Shrub (Prosopis velutina) encroachment in a semidesert grassland: spatial–temporal changes in soil organic carbon and nitrogen pools
Authors: THROOP HEATHER L. , ARCHER STEVEN R.
Published: May 2008

Recent trends of increasing woody vegetation in arid and semiarid ecosystems may contribute substantially to the North American C sink. There is considerable uncertainty, however, in the extent to which woody encroachment alters dryland soil organic carbon (SOC) and total nitrogen (TN) pools. To date, studies assessing SOC and TN response to woody plant proliferation have not explicitly assessed the variability caused by shrub age or size and subcanopy spatial gradients. These factors were quantified via spatially intensive soil sampling around Prosopis velutina shrubs in a semidesert grassland, using shrub size as a proxy for age. We found that bulk density increased with distance from the bole (P < 0.005) and decreased with increasing shrub size (P= 0.056), while both SOC and TN increased with shrub size and decreased with distance from the bole (P < 0.001 for both). Significant (and predictable) spatial variation in bulk density suggests that use of generic values would generate unreliable estimates of SOC and TN mass, and subcanopy SOC pools could be overestimated by nearly 30% if intercanopy bulk density values were applied to subcanopy sites. Predictive models based on field‐documented spatial patterns were used to generate integrated estimates of under‐shrub SOC and TN pools, and these were compared with results obtained by typical area‐weighting protocols based on point samples obtained next to the bole or at a specified distance from the bole. Values obtained using traditional area‐weighting approaches generally overestimated SOC pools relative to those obtained using the spatially integrated approach, the discrepancy increasing with increasing shrub size and proximity of the point sample to the bole. These discrepancies were observed at the individual plant scale and for landscapes populated by various shrub size classes. Results suggest that sampling aimed at quantifying shrub encroachment impacts on SOC and TN pools will require area‐weighting algorithms that simultaneously account for shrub size (age) and subcanopy spatial patterns.
Contemporary carbon accumulation in a boreal oligotrophic minerogenic mire – a significant sink after accounting for all C‐fluxes
Authors: NILSSON MATS , SAGERFORS JÖRGEN , BUFFAM ISHI , LAUDON HJALMAR , ERIKSSON TOBIAS , GRELLE ACHIM , KLEMEDTSSON LEIF , WESLIEN PER , LINDROTH ANDERS
Published: May 2008

Based on theories of mire development and responses to a changing climate, the current role of mires as a net carbon sink has been questioned. A rigorous evaluation of the current net C‐exchange in mires requires measurements of all relevant fluxes. Estimates of annual total carbon budgets in mires are still very limited. Here, we present a full carbon budget over 2 years for a boreal minerogenic oligotrophic mire in northern Sweden (64°11′N, 19°33′E). Data on the following fluxes were collected: land–atmosphere CO2 exchange (continuous Eddy covariance measurements) and CH4 exchange (static chambers during the snow free period); TOC (total organic carbon) in precipitation; loss of TOC, dissolved inorganic carbon (DIC) and CH4 through stream water runoff (continuous discharge measurements and regular C‐concentration measurements). The mire constituted a net sink of 27±3.4 (±SD) g C m−2 yr−1 during 2004 and 20±3.4 g C m−2 yr−1 during 2005. This could be partitioned into an annual surface–atmosphere CO2 net uptake of 55±1.9 g C m−2 yr−1 during 2004 and 48±1.6 g C m−2 yr−1 during 2005. The annual NEE was further separated into a net uptake season, with an uptake of 92 g C m−2 yr−1 during 2004 and 86 g C m−2 yr−1 during 2005, and a net loss season with a loss of 37 g C m−2 yr−1 during 2004 and 38 g C m−2 yr−1 during 2005. Of the annual net CO2‐C uptake, 37% and 31% was lost through runoff (with runoff TOC>DIC≫CH4) and 16% and 29% through methane emission during 2004 and 2005, respectively. This mire is still a significant C‐sink, with carbon accumulation rates comparable to the long‐term Holocene C‐accumulation, and higher than the C‐accumulation during the late Holocene in the region.
Negative fire feedback in a transitional forest of southeastern Amazonia
Authors: BALCH JENNIFER K. , NEPSTAD DANIEL C. , BRANDO PAULO M. , CURRAN LISA M. , PORTELA OSVALDO , De CARVALHO OSWALDO , LEFEBVRE PAUL
Published: May 2008

Anthropogenic understory fires affect large areas of tropical forest, particularly during severe droughts. Yet, the mechanisms that control tropical forests' susceptibility to fire remain ambiguous. We tested the widely accepted hypothesis that Amazon forest fires increase susceptibility to further burning by conducting a 150 ha fire experiment in a closed‐canopy forest near the southeastern Amazon forest–savanna boundary. Forest flammability and its possible determinants were measured in adjacent 50 ha forest plots that were burned annually for 3 consecutive years (B3), once (B1), and not at all (B0). Contrary to expectation, an annual burning regime led to a decline in forest flammability during the third burn. Microclimate conditions were more favorable compared with the first burn (i.e. vapor pressure deficit increased and litter moisture decreased), yet flame heights declined and burned area halved. A slight decline in fine fuels after the second burn appears to have limited fire spread and intensity. Supporting this conclusion, fire spread rates doubled and burned area increased fivefold in B3 subplots that received fine fuel additions. Slow replacement of surface fine fuels in this forest may be explained by (i) low leaf litter production (4.3 Mg ha−1 yr−1), half that of other Amazon forests; and (ii) low fire‐induced tree and liana mortality (5.5±0.5% yr−1, SE, in B3), the lowest measured in closed‐canopy Amazonian forests. In this transitional forest, where severe seasonal drought removed moisture constraints on fire propagation, a lack of fine fuels inhibited the intensity and spread of recurrent fire in a negative feedback. This reduction in flammability, however, may be short‐lived if delayed tree mortality or treefall increases surface fuels in future years. This study highlights that understanding fuel input rate and timing relative to fire frequency is fundamental to predicting transitional forest flammability – which has important implications for carbon emissions and potential replacement by scrub vegetation.
Warming and drought alter C and N concentration, allocation and accumulation in a Mediterranean shrubland
Authors: SARDANS JORDI , PEÑUUELAS JOSEP , ESTIARTE MARC , PRIETO PATRICIA
Published: May 2008

We investigated the effects of warming and drought on C and N concentrations, nitrogen use efficiency (NUE), and C and N accumulation in different ecosystem compartments. We conducted a 6‐year (1999–2005) field experiment to simulate the climate conditions projected by IPCC models for the coming decades in a Mediterranean shrubland. We studied the two dominant species, Globularia alypum and Erica multiflora, and an N‐fixing species, Dorycnium pentaphyllum, also abundant in this shrubland. Warming (1 °C) decreased N leaf concentrations by 25% and increased N stem concentrations by 40% in G. alypum. Although warming changed the available ammonium in soil in some seasons, it did not increase total soil N contents. Drought (19% average reduction in soil moisture) decreased leaf N concentrations in the two dominant shrub species, E. multiflora and G. alypum by 16% and 19%, respectively, and increased stem N concentrations by 56% and 40%, respectively. Neither warming nor drought changed the leaf N concentrations in the N‐fixing species D. pentaphyllum, although warming increased stem N concentration by 9%. In G. alypum, the increase of stem N concentrations contributed to the observed increase of N accumulation in stem biomass in drought treatments with respect to control plots (8 kg N ha−1). Neither warming nor drought changed NUE in the period 1999–2005. Warming increased soil organic C relative to drought. The effects of warming and drought on C and N concentrations, on N accumulation and on leaf/stem N distribution were not the result of dilution or concentration effects produced by changes in biomass accumulation. Other factors such as the changes in soil N availability, photosynthetic capacity, and plant internal C and N remobilization must be involved. These changes which differed depending on the species and the plant tissue show that the climate change projected for the coming decades will have significant effects on the C and N cycle and stoichiometry, with probable implications for ecosystem structure and function, such as changes in plant–herbivore relationships, decomposition rates or community species composition.
The stripe‐backed weasel Mustela strigidorsa: taxonomy, ecology, distribution and status
Authors: ABRAMOV A. V. , DUCKWORTH J. W. , WANG Y. X. , ROBERTON S. I.
Published: May 2008

The stripe‐backed weasel Mustela strigidorsa is one of the rarest and least‐known mustelids in the world. Its phylogenetic relationships with other Mustela species remain controversial, though several unique morphological features distinguish it from congeners.

It probably lives mainly in evergreen forests in hills and mountains, but has also been recorded from plains forest, dense scrub, secondary forest, grassland and farmland. Known sites range in altitude from 90 m to 2500 m. Data are insufficient to distinguish between habitat and altitudes which support populations, and those where only dispersing animals may occur.

It has been confirmed from many localities in north‐east India, north and central Myanmar, south China, north Thailand, north and central Laos, and north and central Vietnam. Given the limited survey effort, the number of recent records shows that the species is not as rare as hitherto believed. Neither specific nor urgent conservation needs are apparent.
Holocene environmental changes and the seal (Phocidae) fauna of the Baltic Sea: coming, going and staying
Authors: SCHMÖLCKE ULRICH
Published: May 2008

The occurrence of different species of seal (Phocidae) during the Holocene in north‐eastern Europe was influenced by a changing geological situation over the last 12 000 years, characterized by alternating freshwater, brackish and marine stages and by spatially and temporally limited opportunities for migration of marine species into the Baltic basin. The patterns of immigration by ringed seal Phoca hispida, harp seal Phoca groenlandica, grey seal Halichoerus grypus and harbour seal Phoca vitulina are reviewed here in order to understand present distributions and population sizes. Furthermore, the future of their populations is analysed.

Phoca hispida immigrated into the Baltic basin during its brackish Yoldia Stage at the Late Glacial/Early Holocene boundary and has persisted in some disjunct populations until now. A second immigration followed at the beginning of the Littorina Transgression – which resulted in the present stage of the Baltic Sea, obviously caused by the strong cooling event that occurred 6200 calibrated 14C years BC. Its present status is not threatened, but global warming will restrict suitable habitat.

Phoca groenlandica had a mid‐Holocene intermezzo in the Baltic Sea. Its later disappearance was probably caused by hunting of subadult animals by humans.

Halichoerus grypus and Phoca vitulina also immigrated at the beginning of the present stage of the Baltic Sea. Whereas H. grypus has been common from this beginning point until modern times, the population of P. vitulina persisted at a low level for millennia. Only since the 18th century has its population increased and spread over the whole Baltic Sea.
A transcription factor regulatory cascade controls secreted aspartic protease expression in Candida albicans
Authors: Dabas Neelam , Morschhäuser Joachim
Published: May 2008

Secreted aspartic proteases (Saps) contribute to the virulence of Candida albicans, a major fungal pathogen of humans. One function of the Saps, which is specifically mediated by the Sap2p isoenzyme, is the degradation of proteins for use as a nitrogen source. The utilization of alternative nitrogen sources in fungi is controlled by GATA transcription factors and we found that C. albicans mutants lacking the GATA transcription factors Gln3p and Gat1p were unable to grow in a medium containing bovine serum albumin (BSA) as the sole nitrogen source. The growth defect was mainly caused by the inability of gln3Δgat1Δ mutants to express the SAP2 gene, as SAP2 expression from the constitutive ADH1 promoter restored the ability of the mutants to grow on BSA. Expression of STP1, which encodes a transcription factor that is required for SAP2 induction in the presence of proteins, was regulated by Gln3p and Gat1p, and forced expression of STP1 from a tetracycline‐inducible promoter bypassed the requirement of the GATA transcription factors for growth of C. albicans on proteins. SAP2 is repressed when preferred nitrogen sources are available and this nitrogen catabolite repression of SAP2 was correlated with downregulation of STP1 in the presence of high concentrations of ammonium, glutamine or urea. Tetracycline‐induced STP1 expression abolished nitrogen catabolite repression of SAP2, demonstrating that the control of STP1 expression levels by the GATA transcription factors is a key aspect of both positive and negative regulation of SAP2 expression. Therefore, secreted aspartic protease expression, a long‐known virulence attribute of C. albicans, is controlled by a regulatory cascade in which the general regulators Gln3p and Gat1p control the expression of the transcription factor Stp1p, which in turn mediates SAP2 expression.
Candida glabrata environmental stress response involves Saccharomyces cerevisiae Msn2/4 orthologous transcription factors
Authors: Roetzer Andreas , Gregori Christa , Jennings Ann Marie , Quintin Jessica , Ferrandon Dominique , Butler Geraldine , Kuchler Karl , Ammerer Gustav , Schüller Christoph
Published: May 2008

We determined the genome‐wide environmental stress response (ESR) expression profile of Candida glabrata, a human pathogen related to Saccharomyces cerevisiae. Despite different habitats, C. glabrata, S. cerevisiae, Schizosaccharomyces pombe and Candida albicans have a qualitatively similar ESR. We investigate the function of the C. glabrata syntenic orthologues to the ESR transcription factor Msn2. The C. glabrata orthologues CgMsn2 and CgMsn4 contain a motif previously referred to as HD1 (homology domain 1) also present in Msn2 orthologues from fungi closely related to S. cerevisiae. We show that regions including this motif confer stress‐regulated intracellular localization when expressed in S. cerevisiae. Site‐directed mutagenesis confirms that nuclear export of CgMsn2 in C. glabrata requires an intact HD1. Transcript profiles of CgMsn2/4 mutants and CgMsn2 overexpression strains show that they regulate a part of the CgESR. CgMsn2 complements a S. cerevisiae msn2 null mutant and in stressed C. glabrata cells, rapidly translocates from the cytosol to the nucleus. CgMsn2 is required for full resistance against severe osmotic stress and rapid and full induction of trehalose synthesis genes (TPS1, TPS2). Constitutive activation of CgMsn2 is detrimental for C. glabrata. These results establish an Msn2‐regulated general stress response in C. glabrata.
A role for Lon protease in the control of the acid resistance genes of Escherichia coli
Authors: Heuveling Johanna , Possling Alexandra , Hengge Regine
Published: May 2008

Lon protease is a major protease in cellular protein quality control, but also plays an important regulatory role by degrading various naturally unstable regulators. Here, we traced additional such regulators by identifying regulons with co‐ordinately altered expression in a lon mutant by genome‐wide transcriptional profiling. Besides many members of the RcsA regulon (which validates our approach as RcsA is a known Lon substrate), many genes of the σS‐dependent general stress response were upregulated in the lon mutant. However, the lon mutation did not affect σS levels nor σS activity in general, suggesting specific effects of Lon on secondary regulators involved in the control of subsets of σS‐controlled genes. Lon‐affected genes also included the major acid resistance genes (gadA, gadBC, gadE, hdeAB and hdeD), which led to the discovery that the essential acid resistance regulator GadE (whose expression is σS‐controlled) is degraded in vivo in a Lon‐dependent manner. GadE proteolysis is constitutive as it was observed even under conditions that induce the system (i.e. at low pH or during entry into stationary phase). GadE degradation was found to rapidly terminate the acid resistance response upon shift back to neutral pH and to avoid overexpression of acid resistance genes in stationary phase.
Mutations in the multi‐drug resistance regulator MRR1, followed by loss of heterozygosity, are the main cause of MDR1 overexpression in fluconazole‐resistant Candida albicans strains
Authors: Dunkel Nico , Blaß Julia , Rogers P. David , Morschhäuser Joachim
Published: May 2008

Overexpression of the MDR1 gene, encoding a multi‐drug efflux pump of the major facilitator superfamily, is a major cause of resistance to the widely used antifungal agent fluconazole and other toxic substances in the fungal pathogen Candida albicans. We found that all tested clinical and in vitro generated C. albicans strains that had become fluconazole‐resistant by constitutive MDR1 upregulation contained mutations in the MRR1 gene, which encodes a transcription factor that controls MDR1 expression. Introduction of the mutated alleles into a drug‐susceptible C. albicans strain resulted in activation of the MDR1 promoter and multi‐drug resistance, confirming that the amino acid substitutions in Mrr1p were gain‐of‐function mutations that rendered the transcription factor constitutively active. The majority of the MDR1 overexpressing strains had become homozygous for the mutated MRR1 alleles, demonstrating that the increased resistance level conferred by two gain‐of‐function alleles provides sufficient advantage to select for the loss of heterozygosity in the presence of fluconazole both in vitro and within the human host during therapy. Loss of heterozygosity usually occurred by mitotic recombination between the two chromosome 3 homologues on which MRR1 is located, but evidence for complete loss of one chromosome and duplication of the chromosome containing the mutated MRR1 allele was also obtained in two in vitro generated fluconazole‐resistant strains. These results demonstrate that gain‐of‐function mutations in MRR1 are the major, if not the sole, mechanism of MDR1 overexpression in fluconazole‐resistant strains and that this transcription factor plays a central role in the development of drug resistance in C. albicans.
Abscisic acid signalling when soil moisture is heterogeneous: decreased photoperiod sap flow from drying roots limits abscisic acid export to the shoots
Authors: DODD IAN C. , EGEA GREGORIO , DAVIES WILLIAM J.
Published: May 2008

To investigate the contribution of different parts of the root system to total sap flow and leaf xylem abscisic acid (ABA) concentration ([X‐ABA]leaf), individual sunflower (Helianthus annuus L.) shoots were grafted onto the root systems of two plants grown in separate pots and sap flow through each hypocotyl measured below the graft union. During deficit irrigation (DI), both pots received the same irrigation volumes, while during partial root zone drying (PRD) one pot (‘wet’) was watered and another (‘dry’) was not. During PRD, once soil water content (θ) decreased below a threshold, the fraction of sap flow from drying roots declined. As θ declined, root xylem ABA concentration increased in both irrigation treatments, and [X‐ABA]leaf increased in DI plants, but [X‐ABA]leaf of PRD plants actually decreased within a certain θ range. A simple model that weighted ABA contributions of wet and dry root systems to [X‐ABA]leaf according to the sap flow from each, better predicted [X‐ABA]leaf of PRD plants than either [X‐ABA]dry, [X‐ABA]wet or their mean. Model simulations revealed that [X‐ABA]leaf during PRD exceeded that of DI with moderate soil drying, but continued soil drying (such that sap flow from roots in drying soil ceased) resulted in the opposite effect.
The lack of alternative oxidase at low temperature leads to a disruption of the balance in carbon and nitrogen metabolism, and to an up‐regulation of antioxidant defence systems in Arabidopsis thaliana leaves
Authors: WATANABE CHIHIRO K. , HACHIYA TAKUSHI , TERASHIMA ICHIRO , NOGUCHI KO
Published: May 2008

Alternative oxidase (AOX) catalyses the ATP‐uncoupling cyanide (CN)‐resistant pathway. In this study, our aim was to clarify the physiological role of AOX at low temperature. We examined the effect of low‐temperature treatment on CN‐resistant respiration (CN‐resistant R) and on the transcription of respiratory components in wild‐type (WT) and aox1a knock‐out transgenic (aox1a) Arabidopsis thaliana plants. In WT leaves, the expression of AOX1a mRNA was strongly induced by the low‐temperature treatment, and thus CN‐resistant R increased during low‐temperature treatment. In aox1a, the CN‐sensitive respiration, and the expression of NDB2 and UCP1 were increased compared with WT. We compared several physiological parameters between WT and aox1a. Low‐temperature treatment did not result in a visible phenotype to distinguish aox1a from WT. In aox1a, several antioxidant defence genes were induced, and the malondialdehyde content was lower than in WT. Starch content and a ratio of carbon to nitrogen were higher in aox1a than in WT. Our results indicate that a lack of AOX was linked to a difference in the carbon and nitrogen balance, and an up‐regulation of the transcription of antioxidant defence system at low temperature. It is likely that AOX is a necessary component in antioxidant defence mechanisms and for the control of a balanced metabolism.
Determining the origin of soft‐sediment deformation structures: a case study from Upper Carboniferous delta deposits in south‐west Wales, UK
Authors: Owen Geraint , Moretti Massimo
Published: May 2008

Determining the cause of sediment mobilization is a major problem; possible triggers include earthquakes, sediment loading and wave action. A detailed sedimentological and palaeoenvironmental analysis of soft‐sediment deformation in Upper Carboniferous deltaic deposits in SW Wales, UK, shows that two styles of deformation occur. Type A (syndepositional convolute stratification) affects most sandstone beds and was generated by rapid sedimentation. Type B (localized sand‐in‐sand pseudonodules) incorporates beds that already contained Type A deformation, and developed when the substrate was liquefied by disturbance due to movement on a near‐surface gravity slide. Neither type of deformation was triggered by seismic events.
Alteration geochemistry of the Nopal I uranium deposit (Sierra Peña Blanca, Mexico), a natural analogue for a radioactive waste repository in volcanic tuffs
Authors: Calas Georges , Agrinier Pierre , Allard Thierry , Ildefonse Philippe
Published: May 2008

Natural analogues provide an approach to characterize and test the long‐term modelling of a repository performance. This article presents geochemical information about the alteration conditions of the Nopal I uranium deposit, Mexico, an analogue for the proposed Yucca Mountain radioactive waste repository. Mineralization and hydrothermal alteration of volcanic tuffs are contemporaneous, according to petrographic observations. Trace element geochemistry (U, Th, REE) provides evidence for local mobilization of uranium under oxidizing conditions and further precipitation under reducing conditions. O‐ and H‐isotope geochemistry of kaolinite, smectite, opal and calcite suggests that argillic alteration proceeded at shallow depth with meteoric water at 25–75 °C, a low‐temperature context, unusual for volcanic‐hosted uranium deposits. This temperature range is compatible with some post‐closure evolution models of the proposed Yucca Mountain repository.
Cenozoic denudation in the Marrakech High Atlas, Morocco: insight from apatite fission‐track thermochronology
Authors: Missenard Yves , Saddiqi Omar , Barbarand Jocelyn , Leturmy Pascale , Ruiz Geoffrey , El Haimer Fatima‐Zahra , Frizon de Lamotte Dominique
Published: May 2008

In North Africa, the High Atlas belt culminates at more than 4000 m. In Morocco, recent work shows that a lithospheric thinning explains about 1000 m of the mean topography, the remaining topography being related to crustal shortening. We combine regional geology with new apatite fission‐track (AFT) ages to constrain the timing of these events in the Marrakech High Atlas (MHA). In the inner belt, 10 AFT ages are comprised between 9 ± 1 and 27 ± 3 Ma. These Neogene ages indicate that the MHA underwent significant denudation during that time. In the southern foreland domain of the belt, three samples give scattered AFT ages between 27 ± 2 and 87 ±5 Ma. Geological evidences allow us to constrain the age of a major denudation event during Middle Miocene age. We propose that it is linked to the thermal doming highlighted in the whole Moroccan Atlas domain.
CLINICAL STUDY: Lack of effect of chronic dextromethorphan on experimental pain tolerance in methadone‐maintained patients
Authors: Compton Peggy A. , Ling Walter , Torrington Matt A.
Published: May 2008

Good evidence exists to suggest that individuals on opioid maintenance for the treatment of addiction (i.e. methadone) are less tolerant of experimental pain than are matched controls or ex‐opioid addicts, a phenomenon theorized to reflect opioid‐induced hyperalgesia (OIH). Agonist activity at the excitatory ionotropic N‐methyl‐D‐aspartate (NMDA) receptor on dorsal horn neurons has been implicated in the development of both OIH and its putative expression at the clinical level—opioid tolerance. The aim of this study was to evaluate the potential utility of the NMDA‐receptor antagonist, dextromethorphan (DEX), to reverse or treat OIH in methadone‐maintenance (MM) patients. Utilizing a clinical trial design and double‐blind conditions, changes in pain threshold and tolerance [cold pressor (CP) and electrical stimulation (ES)] following a 5‐week trial of DEX (titrated to 480 mg/day) in comparison with placebo was evaluated in a well‐characterized sample of MM patients. The sample (n = 40) was 53% male and ethnically diverse (53% Latino, 28% African American, 10% White, 9% other), with a mean age of 48.0 years (SD = 6.97). Based ont‐test analyses, no difference was found between groups on CP pain threshold, CP pain tolerance, ES pain threshold or ES pain tolerance, both pre‐ and postmedication. Notably, DEX‐related changes significantly differed by gender, with women tending to show diminished tolerance for pain with DEX therapy. These results support that chronic high‐dose NMDA antagonism does not improve tolerance for pain in MM patients, although a gender effect on DEX response is suggested.
A specific mixture of short‐chain galacto‐oligosaccharides and long‐chain fructo‐oligosaccharides induces a beneficial immunoglobulin profile in infants at high risk for allergy
Authors: Van Hoffen E. , Ruiter B. , Faber J. , M'Rabet L. , Knol E.F. , Stahl B. , Arslanoglu S. , Moro G. , Boehm G. , Garssen J.
Published: May 2008

Background:  It has been suggested that human breast milk oligosaccharides play a role in the development of the immune system in infants, and may consequently inhibit the onset of allergy. A specific prebiotic mixture of short‐chain galacto‐oligosaccharides and long‐chain fructo‐oligosaccharides (GOS/FOS) has been shown to reduce the incidence of atopic dermatitis (AD) at 6 months of age in infants at risk for allergy.

Aim of the study:  This study was aimed to analyze the effect of GOS/FOS on the immune response in these infants.

Methods:  In a double‐blind randomized placebo‐controlled study, infants received a hypoallergenic whey formula with either 8 g/l GOS/FOS in a 9 : 1 ratio (IMMUNOFORTISTM) or 8 g/l maltodextrine (placebo) for 6 months. At 3 months of age, children were vaccinated with Hexavac against a.o. diphteria, tetanus, polio (DTP). At 6 months of age, plasma samples were collected from 84 infants (verum group n = 41, placebo group n = 43). Levels of total immunoglobulins (Ig) and of cow’s milk protein (CMP‐) and DTP‐specific Ig were measured.

Results:  GOS/FOS supplementation led to a significant reduction in the plasma level of total IgE, IgG1, IgG2 and IgG3, whereas no effect on IgG4 was observed. CMP‐specific IgG1 was significantly decreased. DTP‐specific Ig levels were not affected.

Conclusions:  This study shows that GOS/FOS supplementation induces a beneficial antibody profile. GOS/FOS reduces the total Ig response and modulates the immune response towards CMP, while leaving the response to vaccination intact. This suggests that oral GOS/FOS supplementation is a safe method to restrain the atopic march.
Sputum neurokinin A in Egyptian asthmatic children and adolescents: relation to exacerbation severity
Authors: Mostafa G. A. , Reda S. M. , Abd El‐Aziz M. M. , Ahmed S. A.
Published: May 2008

Background:  Neurogenic inflammation may participate in the development and progression of bronchial asthma. The molecular mechanisms underlying neurogenic inflammation are orchestrated by a large number of neuropeptides including tachykinins such as neurokinin A (NKA) and substance P. Tachykinins are secreted from sensory airway nerves and inflammatory cells after allergens exposure. In clinical practice, assessment of airway inflammation is difficult. Therefore, detection of biological markers of airway inflammation in sputum might offer help for proper monitoring of asthma severity.

Aim of the study:  We aimed to measure sputum NKA in relation to acute asthma exacerbations of varying severity.

Methods:  Sputum NKA was measured by enzyme‐linked immunosorbent assay in 24 children and adolescents during and after acute asthma exacerbation and 24 healthy matched controls.

Results:  Sputum NKA was significantly higher in asthmatic patients during acute exacerbation than controls [217.5 (284) vs 10 (7) ng/ml, P < 0.001]. When patients with acute asthma exacerbation were followed‐up till remission, sputum NKA levels decreased significantly, but they remained significantly higher than controls. Sputum NKA levels were significantly higher in severe than moderate and in moderate than mild exacerbations, and was negatively correlated to peak expiratory flow rate (r = −0.9, P < 0.001). Sputum NKA had significant positive correlations to eosinophil counts in blood and sputum (r = 0.6, P < 0.001 and r = 0.7, P < 0.001 respectively).

Conclusions:  Sputum NKA is up‐regulated during acute asthma exacerbation and it positively correlates to its severity. Thus, NKA may aid in objective classification of the exacerbation severity. In addition, NKA may be a target for new asthma therapy.
Effects of bio‐pesticides on Eretmocerus warrae (Hym., Aphelinidae), a parasitoid of Bemisia tabaci (Hom., Aleyrodidae)
Authors: Kumar P. , Whitten M. , Thoeming G. , Borgemeister C. , Poehling H.‐M.
Published: May 2008

The sweet potato whitefly Bemisia tabaci (WF) can be controlled by two commercial neem products, NeemAzal‐T/S® (1% azadirachtin) for foliar application, and NeemAzal‐U (17% azadirachtin) for soil application, alongwith two biorational products of microbial origin, Abamectin (avermectin) and Success® (spinosad). Side effects of these products were tested in a laboratory bioassay against a native aphelinid, Eretmocerus warrae (EW). Eggs and early larval instars of the parasitoid, commonly found outside the host body, were highly susceptible to foliar spray of neem with only 8%, 18% and 55% emergences of adults from treated eggs. larval and pupal stages respectively at recommended dose‐rates of 5 ml/l and 1%, 8% and 40% at twice recommend dose‐rate (10 ml/l). Soil application with NeemAzal‐U marginally affected EW. At highest tested dose‐rate of 3.0 g/l, 46%, 64% and 81% emergence was recorded after treatement of plants harbouring WF parasitized by egg, larval and pupal stages of EW respectively. In contrast to neem application, Success® and Abamectin caused high mortality in development stages of the parasitoids. In particular, abamectin was highly toxic to the parasitoids with less than 1% emergence from either of the three development stages if treated with 1–2 ml/l.
Effects of nutrients on feeding activities of the pest termite Heterotermes tenuis (Isoptera: Rhinotermitidae)
Authors: Haifig I. , Costa‐Leonardo A. M. , Marchetti F. F.
Published: May 2008

Heterotermes tenuis is a native termite of large negative impact on the Brazilian economy. Many studies have focused on optimizing the baiting method for termite control by improving its use and its efficacy. In order to maximize termite bait consumption, this study aimed to select nutrient solutions which are able to enhance termite feeding. The effects of some sugars and urea on feeding preference of the subterranean termite H. tenuis were determined by double choice feeding tests, and the consumption was evaluated by variation in dry mass of filter paper after 28 days of termite feeding. Most of the solutions tested did not significantly influence feeding of H. tenuis. Termites fed preferentially on filter paper treated with 0.03 g/ml trehalose and 0.015 g/ml urea solutions. The data indicate that trehalose and urea solutions are phagostimulants to H. tenuis, and their future use in bait matrices may increase consumption of baits and improve this control technique.
Diversity analysis for resistance of rice (Oryza sativa L.) to blast disease [Magnaporthe grisea (Hebert) Barr.] using differential isolates from the Philippines
Authors: Telebanco‐Yanoria M. J. , Ohsawa R. , Senoo S. , Kobayashi N. , Fukuta Y.
Published: May 2008

A wide variation in resistance to blast disease caused by Magnaporthe grisea (Hebert) Barr. (Rossman et al. 1992) was found using 922 rice (Oryza sativa L.) varieties collected mainly from Asia. These were classified into six varietal groups, termed clusters A–F, according to Ward’s hierarchical cluster analysis, based on the reaction pattern to 20 standard differential blast isolates from the Philippines. The most susceptible two clusters, B and C, dominated in varieties from the Far East (Japan). Varieties from East Asia and Southeast Asia occurred less frequently in B and C clusters than those of Japan, and more frequently in E and F clusters, which were the most resistant of the cluster groups. Varieties from South Asia showed the widest variation, occurring in all clusters but less frequently in cluster B. The cluster B varieties dominated in Japan and showed a high frequency of isozyme type VI, corresponding to Japonica type. In contrast, the frequency of cluster B was low in the groups with isozyme types I, II, III and V, which dominated in South Asia. Isozyme type I corresponds to Indica type varieties. The distribution of resistance corresponded to the geographical distribution of rice varieties and might be related to differentiation into Indica and Japonica types. These findings will provide useful information for understanding the variation in blast resistance at the global level.
Assessment of the resistance of cotton germplasm (Gossypium spp.) to aphids (Homoptera, Aphididae) and leafhoppers (Homoptera: Cicadellidae, Typhlocybinae): methodology and genetic variability
Authors: Nibouche S. , Brévault T. , Klassou C. , Dessauw D. , Hau B.
Published: May 2008

We carried out an assessment of the resistance of 71 accessions of cotton (Gossypium spp. L.) to the aphid Aphis gossypii and to leafhoppers under natural infestation. Our objectives were (i) to improve the methods for screening cotton germplasm for resistance to both pests, and (ii) to test the existence of genetic correlation between resistances to both insects. For both insects, the percentage of colonized leaves exhibited high genotypic correlation with the number of insects per leaf, had similar or higher heritabilities, and appeared as the better measure of insect populations. The one‐plant‐per‐plot experimental design used allowed an assessment of resistance with high heritability value, and proved to be suitable for the screening of cotton germplasm. G. arboreum was more resistant to both insects than G. barbadense and G. hirsutum. While hairiness had a significant negative effect on resistance to aphids, no significant effect was observed on resistance to leafhoppers, excepted in G. arboreum. The lack of genotypic correlation between resistance to aphids and to leafhoppers demonstrated that a simultaneous improvement of the resistance is possible.
A genetic linkage map of Physocarpus, a member of the Spiraeoideae (Rosaceae), based on RAPD, AFLP, RGA, SSR and gene specific markers
Authors: Sutherland B. G. , Tobutt K. R. , Marchese A. , Paternoster G. , Simpson D. W. , Sargent D. J.
Published: May 2008

Physocarpus opulifolius is a deciduous shrub native to North America belonging to the Spiraeoideae subfamily of the Rosaceae. The cultivars ‘Luteus’ and ‘Diabolo’ are grown in gardens for their ornamental foliage, golden and purple respectively. We developed a linkage map of P. opulifolius with a view to detecting markers for the leaf colour genes, which are under major gene control. A total of 162 molecular markers (128 RAPDs, 27 AFLPs, three RGA, three STS markers and one SSR) and the leaf colour genes Pur and Aur were scored in the Physocarpus progeny and used to create a linkage map covering 586.1 cM over nine linkage groups. There was an average of 18.2 markers per linkage group and a mean linkage group length of 65.1 cM. Both leaf colour genes were mapped. This is the first reported linkage map of a member of the Spireaeoideae and the mapping of a small number of transferable markers has demonstrated its utility to comparative mapping, which will complement existing comparative mapping efforts in other rosaceous subfamilies.
Clinicopathological characteristics of gastrointestinal mesenchymal tumors and diagnostic value of endoscopic ultrasonography
Authors: Ji Feng , Wang Zi‐Wei , Wang Li‐Jun , Ning Jian‐Wen , Xu Guo‐Qiang
Published: May 2008

Background and Aim:  Gastrointestinal mesenchymal tumors (GIMTs) are tumors which arise from mesenchymal cells other than lymphocytes or epithelial cells and include gastrointestinal stromal tumors (GISTs), smooth muscle tumors, neurogenic tumors, fibroblast tumors, and liparomphalus. Here, we studied the clinicopathologic characteristics of GIMTs and determined the diagnostic value of endoscopic ultrasonography (EUS) in GIMTs.

Methods:  The morphological characteristics of 415 GIMT cases were observed using light microscopy. The expression of CD117, CD34, smooth muscle actin (SMA), S‐100, and Ki‐67 were detected using immunohistochemistry. EUS results were retrospectively analyzed in 76 cases.

Results:  Among the 415 GIMT cases, there were 229 GIST cases, 178 smooth muscle tumor cases, and eight neurogenic tumor cases. Diffuse strong expression of CD117 was observed in 202 (88.2%) GISTs and strong expression of CD34 was observed in 135 (59.0%) GISTs. SMA and S‐100 expression was detected in smooth muscle tumors (leiomyomas/leiomyosarcoma) and neurogenic tumors, respectively. Of the 12 cases with GISTs, nine cases with positive ki‐67 expression and accompanied with more mitosis were pathologically diagnosed as malignant GISTs. Most of the borderline and malignant tumors were found in male patients. EUS was 98.7% accurate in determining GIMT locations, 82.9% accurate in diagnosing GIMTs, and 80.3% accurate in differentiating benign from malignant tumors.

Conclusions:  GISTs, rather than leiomyomas, are the most common GIMTs. Immunohistochemical markers, such as CD117, CD34, SMA, and S‐100, can differentiate GISTs from smooth muscle and neurogenic tumors. The expression of Ki‐67 in patients with significant karyokinesis supports a malignant tumor diagnosis. EUS is an accurate method for detecting GIMTs and differentiating between benign and malignant tumors. Use of endoscopic ultrasound–guided fine‐needle aspiration biopsies may enable clinicians to make more accurate diagnoses than currently used methods.
Physical activity interventions in Hispanic American girls and women
Authors: Sharma M.
Published: May 2008

The purpose of this article was to review physical activity interventions done with Hispanic American girls and women that were published between 1994 and 2007, and suggest ways of enhancing these interventions. A total of 12 such interventions were found. Majority of the interventions focused on both physical activity and nutrition behaviours. Only half of the interventions were based on a behavioural theory. Social cognitive theory was the most popular theory, which was operationalized by four interventions. The interventions ranged from 3 weeks to 2 years in duration. The impact was not necessarily linked to the length of the intervention. The most popular physical activity that was promoted was walking, which was utilized by four interventions. Most of the interventions utilized a classroom format for imparting instruction in being physically active. All the interventions utilized individual‐level behaviour change as an approach, and none tried to address broader policy and environmental‐level changes. Process evaluation was done by very few interventions and must be done more systematically. In terms of the impact, half of the interventions were successful in influencing the outcomes. Recommendations for enhancing the effectiveness of physical activity interventions in Hispanic American girls and women are presented.
Subcontracting and vertical integration in the Spanish cotton industry1
Authors: ROSÉS JOAN R.
Published: May 2008

This paper examines changes in the organization of the Spanish cotton industry from 1736 to 1860 in its core region of Catalonia. As the Spanish cotton industry adopted the most modern technology available and experienced the transition to the factory system, cotton spinning and weaving mills became increasingly vertically integrated. Asset specificity, more than other factors, explains this tendency towards vertical integration. The probability of a firm being vertically integrated was higher among firms located in districts with high concentration ratios, and rose with size and the use of modern machinery. At the same time, subcontracting predominated in other phases of production and distribution, where transaction costs appear to be less important.