bluuebunny/crossref_metadata_2025 huggingface dataset:
Source reconstruction of an accidental radionuclide release at European scale
Authors: Krysta Monika , Bocquet Marc
Published: March 2007

We develop and experiment with new techniques to reconstruct the source of an accidental release of radionuclides at continental scale. The prior information on the source to be accounted for in the inversion is identified. Using methods based on information theory, purposeful cost functions consistent with this prior are constructed. They generalize classical variational least‐square assimilation techniques. The adjoint of the numerical dispersion model POLAIR3D is used in the minimization of these cost functions. The method is tested on a set of twin experiments involving the main European civil nuclear sites as candidate sources. Several experiments are performed. They demonstrate how sensitive the retrievals are to the prior, the meteorological conditions, the source profile shape and the errors. A reconstruction is then attempted on the Algeciras incident, which took place in southern Spain in May 1998. A truly successful three‐dimensional inversion is out of reach with the available observations. However, a temporal reconstruction of the event succeeds, and this exemplifies the newly designed cost functions. Copyright © 2007 Royal Meteorological Society
The impact on weather forecasts of targeted observations during A‐TReC
Authors: Petersen G. N. , Thorpe A. J.
Published: March 2007

The impact of the additional observations from the Atlantic THORPEX Regional Campaign (A‐TReC) on forecasts made with the UK Met Office operational forecast system is assessed. A total of 38 forecasts are analysed in which the forecasts range is between 30 and 78 hours. The absolute observational impact is evaluated as well as the effect on forecast error.

The results show that in most events, irrespective of whether there was a forecast improvement or not, the additional observations were made in the correct locations as the impact of the observations reached the verification areas at verification time. Thus, the guidance of the sensitive‐area prediction techniques was generally very successful in identifying sensitive regions. The observational impact resulted in a general improvement of the forecasts in 32% of the events, but in about half of the events there were improvements in some fields. These results need to be considered in the light of the fact that during the A‐TReC period, forecast errors were generally small. Thus, there was little room for improvements and consequently, as anticipated from previously published research, there was a significant risk of forecast deterioration. A detailed examination of four events demonstrates a complex range of behaviour in the role of targeted observations in realising forecast improvements. It is proposed that forecast improvements due to targeted observations are critically dependent on the properties of the data assimilation scheme, whilst predictions of the location of sensitive regions are successful using current techniques. Copyright © 2007 Royal Meteorological Society
Assimilation of MIPAS limb radiances in the ECMWF system. I: Experiments with a 1‐dimensional observation operator
Authors: Bormann N. , Thépaut J.‐N.
Published: March 2007

Emitted infrared limb radiances from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) are for the first time assimilated directly in a global numerical weather prediction system, using a fast radiative transfer model that assumes local horizontal homogeneity. This study reports on the monitoring of the observed MIPAS radiances against model equivalents, and the subsequent assimilation experiments within a 4‐dimensional variational data assimilation system. The impact of the limb radiance assimilation on the resulting analyses and forecasts is assessed by considering the fit to other observations assimilated in the system and by comparing the resulting analyses with independent data.

The results demonstrate the feasibility of direct assimilation of emitted infrared limb radiances and highlight how information on stratospheric temperature, humidity, and ozone can be extracted from the radiances directly within the assimilation system. The assimilation of MIPAS radiances leads to considerable differences in the mean stratospheric analyses, without a significant degradation of the fit to other observations used in the assimilation. The assimilation of MIPAS limb radiances appears to correct temperature biases with an oscillatory structure above 10 hPa in the analyses, and the assimilation leads to a considerable moistening of the stratosphere, typically by 20–40%. For ozone, the assimilation causes an increase in the tropical ozone maximum in the analysis, and a reduction of ozone over the poles. The changes to the humidity and ozone fields are retained in the subsequent 10‐day forecast.

The changes introduced in the analyses are overall supported qualitatively and quantitatively by independent retrievals of temperature and humidity; results for ozone are more mixed. Analyses with MIPAS radiances agree better with independent ozone sondes or retrievals over the North Polar region, whereas over the Tropics the changes to the mean ozone analyses are not supported by other observations. The limb radiance assimilation shows considerable sensitivity to the bias correction applied to the limb radiances prior to the assimilation, suggesting that the assimilation would benefit from refinements in the bias correction method. Copyright © 2007 Royal Meteorological Society
Assimilation of MIPAS limb radiances in the ECMWF system. II: Experiments with a 2‐dimensional observation operator and comparison to retrieval assimilation
Authors: Bormann N. , Healy S. B. , Hamrud M.
Published: March 2007

This study applies and compares three different ways of assimilating MIPAS data in a global numerical weather prediction system. The three methods are: direct assimilation of emitted infrared limb radiances with a 1‐dimensional radiative transfer model that assumes local horizontal homogeneity; direct assimilation of radiances with a 2‐dimensional radiative transfer model that takes into account horizontal gradients in the atmosphere; and assimilation of retrieved profiles of temperature, humidity and ozone, derived under the assumption of horizontal homogeneity. The resulting analyses are compared against each other and against independent retrievals.

The use of a 2‐dimensional radiative transfer model in the radiance assimilation leads to relatively small differences in the analyses compared to using a 1‐dimensional observation operator in our experiments. Nevertheless, the results show that the 2‐dimensional operator correctly takes into account the effect of tangent point drift, is capable of extracting a limited amount of horizontal structure from a single MIPAS scan, and leads to smaller first‐guess departures for lower tangent altitudes and more strongly absorbing channels. Consequently, humidity and ozone increments from a 2‐dimensional operator are smaller in the lower stratosphere and upper troposphere in areas where considerable horizontal gradients prevail, and forecasts of humidity and ozone are improved in these regions.

In these first trials with assimilation of limb radiances, both the radiance and the retrieval assimilation appear capable of incorporating useful information from MIPAS in the analyses. Both methods introduce broadly similar changes to the mean analyses, with little indication of which method should be favoured. Nevertheless, results from the retrieval assimilation compare better to independent ozone data in the Tropics and over Antarctica. For the radiance assimilation, there are many areas with scope for improvement; these are discussed at the end of the paper. Copyright © 2007 Royal Meteorological Society
Photoreactions and lateral patterning in Langmuir and Langmuir–Blodgett films
Authors: Matsumoto Mutsuyoshi
Published: March 2007

Reversible morphological changes occur with photoisomerization of azobenzene in Langmuir–Blodgett (LB) films complexed with polycations, which contradicts an implicit assumption of the concept of free volume that two‐dimensional film structures are preserved during the photoisomerization. J‐aggregates of chromophores are formed by two processes. The first process is “light‐induced J‐aggregation” in which photoisomerized molecules form J‐aggregates. The other process is “triggered J‐aggregation,” in which photoisomerization of one of the components triggers J‐aggregation of another chemical species in the mixed films. Both processes of J‐aggregation are in many cases accompanied by large morphological changes of the films. However, LB films fabricated using processes under isobaric conditions do not change their morphology during light‐induced J‐aggregation and are patterned with J‐aggregates using ultraviolet illumination through a photomask. Phase separation in mixed LB films gives rise to two‐dimensional patterns, which are used to fabricate templates by using an amphiphilic silane‐coupling agent as one of the components in the mixed LB films. Nanopatterns are also fabricated. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 69–77; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20099
Value of electric heat boilers and heat pumps for wind power integration
Authors: Meibom Peter , Kiviluoma Juha , Barth Rüdiger , Brand Heike , Weber Christoph , Larsen Helge V.
Published: March 2007

The paper analyses the economic value of using electric heat boilers and heat pumps as wind power integration measures relieving the link between the heat and power production in combined heat and power plants. Both measures have different technical and economic characteristics, making a comparison of the value of these measures relevant. A stochastic, fundamental bottom‐up model, taking the stochastic nature of wind power production explicitly into account when making dispatch decisions, is used to analyse the technical and economical performance of these measures in a North European power system covering Denmark, Finland, Germany, Norway and Sweden. Introduction of heat pumps or electric boilers is beneficial for the integration of wind power, because the curtailment of wind power production is reduced, the price of regulating power is reduced and the number of hours with very low power prices is reduced, making the wind power production more valuable. The system benefits of heat pumps and electric boilers are connected to replacing heat production on fuel oil heat boilers and combined heat and power (CHP) plants using various fuels with heat production using electricity and thereby saving fuel. The benefits of the measures depend highly on the underlying structure of heat production. The integration measures are economical, especially in systems where the marginal heat production costs before the introduction of the heat measures are high, e.g. heat production on heat boilers using fuel oil. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of deposition of deer dung on nutrient redistribution and on soil and plant nutrients on intensively grazed grasslands in lowland Nepal
Authors: Moe Stein R. , Wegge Per
Published: March 2007

Nutrient redistribution, deer response to areas containing dung, and plant and soil nutrient content on grazing lawns and adjacent control areas were studied on intensively grazed grasslands in humid lowland Nepal. Effects of experimental fertilisation of grasslands with different amounts of dung pellets were also studied. A high‐density population of axis deer recirculated 13 tons (dry mass, DM) of dung per month in the 10 km2 study area. Because of preferential use of the grasslands for feeding while resting elsewhere, 10 tons were lost from the grassland to other habitat types per month during the dry season (February–May). The N, P, K, Na, and Mg content of grass from grazing lawns was significantly higher, probably because the grass was kept in a younger phenological stage of growth. In contrast with results from many other studies, the nutrient content of lawn soil was similar to that of adjacent, less intensively grazed areas, apart from P, which was lower in lawn soils. High plant P requirement on grazing lawns and removal of nutrients by deer may explain low soil P levels. Experiments with pellet fertilisation showed that high dung deposition increased plant P content, probably because of increased P uptake during early stages of growth. Dung deposition did not affect deer grazing preferences.
Dietary conjugated linoleic acid increases endurance capacity and fat oxidation in mice during exercise
Authors: Mizunoya Wataru , Haramizu Satoshi , Shibakusa Tetsuro , Okabe Yuki , Fushiki Tohru
Published: March 2007

Ingestion of CLA activates β‐oxidation and causes loss of body fat in rodents. We investigated the effects of dietary CLA on endurance capacity and energy metabolism during exercis in mice. Five‐week‐old male BALB/c mice were fed a control diet containing 1.0% linoleic acid or a diet containing 0.5% CLA that replaced an equivalent amount of linoleic acid for 1 wk. The maximum swimming time until fatigue was significantly higher in the CLA‐fed group than in the control group. During treadmill running, the respiratory exchange ratio was significantly lower in the CLA‐fed group, but oxygen consumption did not differ significantly between groups, suggesting that FA contributed more as an energy substrate in the CLA‐fed mice. The muscle lipoprotein lipase activity was significantly higher in the CLA‐fed group than in the control group. These results suggest that CLA ingestion increases endurance exercise capacity by promoting fat oxidation during exercise.
Metabolities of dietary triacylglycerol and diacylglycerol during the digestion process in rats
Authors: Osaki Noriko , Meguro Shinichi , Yajima Noriyuki , Matsuo Noboru , Tokimitsu Ichiro , Shimasaki Hiroyuki
Published: March 2007

The present study investigated the metabolic fate of dietary TAG and DAG and also their digestion products in the stomach and small intestine. A diet containing 10% TAG or DAG oil, enriched in 1,3‐DAG, was fed to Wistar rats ad libitum for 9 d. After 18 h of fasting, each diet was re‐fed ad libitum for 1 h. The weights of the contents of the stomach and small intestine were measured, and the acylglycerol and FFA levels were analyzed by GC at 0, 1, and 4 h after the 1‐h re‐feeding. The amounts of re‐fed diet ingested and the gastric and small intestinal content were not different between the two diet groups. In the TAG diet group, the main products were TAG and DAG, especially 1(3),2‐DAG. In addition, 1,3‐DAG and 1(3)‐MAG were present in the stomach, and the 1,3‐DAG levels increased over time after the re‐feeding period. In the DAG diet group, the main products in the stomach were DAG, MAG, FFA, and TAG. There were significantly greater amounts of 1,3‐DAG, 1(3)‐MAG, and FFA in the DAG diet group in the stomach compared with the TAG diet group. The amount of FFA in the stomach relative to the amount of ingested TAG plus DAG in the DAG diet group was higher than that in the TAG diet group. Acylglycerol and FFA levels were considerably lower in the small intestine than in the stomach. These results indicate that, in the stomach, where acyl migration might occur, the digestion products were already different between TAG and DAG oil ingestion, and that DAG might be more readily digested by lingual lipase compared with TAG. Furthermore, almost all of the dietary lipid was absorbed, irrespective of the structure of the acylglycerol present in the small intestine.
Identification of Δ7 phytosterols and phytosteryl glucosides in the wood and bark of several Acacia speciesphytosterols and phytosteryl glucosides in the wood and bark of several Acacia species
Authors: Freire Carmen S. R. , Coelho Dora S. C. , Santos Nuno M. , Silvestre Armando J. D. , Pascoal Neto Carlos
Published: March 2007

The wood and bark of four Acacia species growing in Portugal, namely, A. longifolia, A. dealbata, A. melanoxylon, and A. retinodes, were investigated for their sterol content. The lipids fractions of the different wood and bark samples were isolated, and the sterols were identified and quantified by GC‐MS. Two Δ7 sterols, specifically, spinasterol and dihydrospinasterol, were the main sterols found in considerable amounts, particularly in wood tissues (more than 0.5 g/kg of dry wood in the case of A. melanoxylon and A. retinodes). The corresponding unusual steryl glucosides were also identified in significant amounts in the wood and bark extracts.
Reconstruction of a tissue‐engineered skin containing melanocytes
Authors: Liu Yuan , Suwa Fumihiko , Wang Xinwen , Takemura Akimichi , Fang Yi Ru , Li Yuan , Zhao Yu , Jin Yan
Published: March 2007

The objective of this study was to establish a new method for reconstruction of a tissue‐engineered skin containing melanocytes by employing tissue engineering. The keratinocytes, melanocytes and dermal fibroblasts were isolated and purified from human foreskin biopsies. Then the cells were used to construct a tissue‐engineered skin containing melanocytes. The localization of melanocytes in the tissue‐engineered skin was detected by DOPA staining, S‐100 immunohistochemical staining and transmission electron microscope (TEM). The results showed that the melanocytes could be detected in the basal layer of the constructed skin and the melanocytes showed dendritic morphology. Moreover the constructed skins were used to repair the athymic mice skin defects. Animal experiment results indicated that the skin equivalents could successfully repair full thickness skin defects in athymic mice and generated black skins by 6 weeks after grafting. Melanocytes located in the basal layer of the athymic mice skin could also be detected by using the S‐100 immunohistochemical staining. Our established method is useful to repair the full‐thickness skin defects.
Suppression of matrix metalloproteinase‐9 by 4‐methylumbelliferone
Authors: Nakamura Rika , Kuwabara Hiroko , Yoneda Masahiko , Yoshihara Shuichi , Ishikawa Takashi , Miura Tomisato , Nozaka Hiroyuki , Nanashima Naoki , Sato Tatsusuke , Nakamura Toshiya
Published: March 2007

OHK cells, a human lymphoma cell line, are known to produce large amounts of hyaluronan. We investigated the effect of 4‐methylumbelliferone, an inhibitor of hyaluronan synthesis, on the activity of matrix metalloproteinases in OHK cells. Matrix metalloproteinase‐9 was detected on gelatin zymography as the main metalloproteinase excreted into the medium of cultured OHK cells, and 4‐methylumbelliferone added to the medium decreased the activity of the enzyme in a dose‐dependent manner. Addition of Streptomyces hyaluronidase to the medium during cultivation did not decrease the enzyme activity. Reverse transcription‐polymerase chain reaction revealed that 4‐methylumbelliferone markedly decreased the level of mRNA for matrix metalloproteinase‐9 in cultured OHK cells. A similar decrease of the activity of matrix metalloproteinase‐9 by 4‐methylumbelliferone was also observed in cultured human breast and colon carcinoma cells. These results suggest that 4‐methylumbelliferone suppresses the expression of matrix metalloproteinase‐9 in cultured cancer cells.
Apoptosis induced by NO via phosphorylation of p38 MAPK that stimulates NF‐κB, p53 and caspase‐3 activation in rabbit articular chondrocytes
Authors: Wang Honglin , Wang Zhilun , Chen Jinghong , Wu Jin
Published: March 2007

Nitric oxide (NO), reported as an important inducer of apoptosis, plays a considerable role in the pathogenetic mechanisms of articular diseases. This research aimed at investigating the role of p38 MAPK signal transduction pathway on apoptosis induced by NO in rabbit articular chondrocytes. In the present study, NO was produced by a novel NO donor NOC‐18. Rabbit articular chondrocytes were cultured as monolayer, and the first passage cells were used for the experiments. We detected apoptosis induced by NO using Annexin V‐FITC/PI flow cytometry and TUNEL assay. Measurement of caspase‐3 has reflected its activity level. Western blotting was performed to show the protein expressions of p38, NF‐κB, p53 and caspase‐3. Furthermore, we examined the inhibitory effects in the NO pathway with p38‐specific inhibitor SB203580. Treatment with NOC‐18 caused accelerated apoptosis in a concentration dependent manner. This acceleration was able to be reduced when added to SB203580. Besides, the inhibitor could significantly decrease NO‐induced p38, NF‐κB, p53 and caspase‐3 protein expressions, as well as caspase‐3 intracellular activity (P< 0.05). These results suggest that p38 MAPK signal transduction pathway is critical to NO‐induced chondrocyte apoptosis, and p38 plays a role by way of stimulating NF‐κB, p53 and caspase‐3 activation.
P‐glycoprotein expression in extracellular matrix formation of chondrogenic differentiation of human adult stem cells
Authors: Kim Sang Gyung , Jeon Chang Ho , Suh Hun Suk , Choe Jung‐Yoon , Shin Im‐Hee
Published: March 2007

Mesenchymal stem cell (MSC) has been known as a good source of progenitor for multiple connective tissue including cartilage, muscle, adipocyte, and bone. P‐glycoproteins (P‐gps) also known as ABCB1 that exports diverse substrates are the product of the multidrug resistance‐1 (MDR‐1) gene. P‐gp expression has been reported in chondrosarcoma and hypertrophic chondrocyte in the human growth plate. This study was designed to investigate the expression of P‐gp during chondrogenic differentiation of adult human stem cells. Bone marrow samples were obtained from nine human donors after informed consent. The isolated mononuclear cells (MNCs) were incubated as one pellet/tube and 0.5 ml chondrogenic medium in the presence of 10 ng/ml of TGF‐beta 1 and TGF‐beta 3 for 28 days. The expression of surface P‐gps was analyzed by flow cytometry and quantitative RT‐PCR was performed for the detection of mRNA expression of MDR‐1 and type II collagen gene. Total collagen and glycosaminoglycan (GAG) contents of the pellets were measured. Surface P‐gp expression of the MSCs was decreased during chondrogenic differentiation. MDR‐1 gene was decreased 10‐fold after the 2‐week incubation whereas type II collagen gene was increased 491‐fold after the 4‐week incubation in chondrogenic medium. The total amount of collagen and GAG were increased during pellet culture. This study has demonstrated a decrease in expression of P‐gp and down regulation of MDR‐1 gene consistently by flow cytometry and quantitative RT‐PCR, but an increased expression of type II collagen on MSC during chondrogenesis.
Critical function of Ikaros in controlling Aiolos gene expression
Authors: Ghadiri Ata , Duhamel Marianne , Fleischer Aarne , Reimann Andreas , Dessauge Frederic , Rebollo Angelita
Published: March 2007

To characterize the regulation of lymphoid Aiolos transcription factor, we have cloned its promoter. Full promoter and nested deletions were expressed in lymphoid and non‐lymphoid cell lines. The minimal promoter activity could be considered as a 172 bp upstream from the ATG for Jurkat and HEK293 cells and as a 370 bp fragment for U937 cells. Moreover, we have mapped the transcription initiation site. Retardation gels showed binding activity for Ikaros, NFκB and AP4 transcription factors and mutations in their binding sites abolish Aiolos promoter activity. Chromatin immunoprecipitation assay revealed that Ikaros, NFκB and AP4 are bound to Aiolos promoter. The important function of Ikaros and NFκB is underlined by their over expression, which results in the trans‐activation of the promoter and drives Aiolos expression in cell lines and in freshly isolated B and T cells, while over expression of a dominant negative Ikaros isoform is able to block Aiolos expression.
Antenatal Corticosteroid Therapy for Fetal Maturation
Authors:   Committee on Obstetric Practice
Published: March 2007

The National Institute of Child Health and Human Development and the Office of Medical Applications of Research of the National Institutes of Health convened consensus conferences in 1994 and 2000 that recommended giving a single course of corticosteroids to all pregnant women between 24 and 34 weeks of gestation who are at risk of preterm delivery within 7 days. Because of insufficient scientific evidence, the consensus panel also recommended that repeat corticosteroid courses, including so‐called “rescue therapy”, should not be routinely used but should be reserved for women enrolled in clinical trials. Betamethasone and dexamethasone have been most widely studied and have generally been the preferred corticosteroids for antenatal treatment to accelerate fetal organ maturation. The American College of Obstetricians and Gynecologists' Committee on Obstetric Practice supports the conclusions of the consensus conferences.
Predicting the effects of body fatness on food intake and performance of sheep
Authors: Tolkamp Bert J. , Yearsley Jonathan M. , Gordon Iain J. , Illius Andrew W. , Speakman John R. , Kyriazakis Ilias
Published: March 2007

Adipose tissue produces signals that can have a profound effect on many physiological functions, including energy expenditure and food intake. The hypothesis that variation in food intake of sheep resulting from differences in animal fatness can be predicted from effects of animal fatness on energetic efficiency was subjected to three tests. First, an existing food intake model was adapted to account for effects of animal fatness, as estimated by condition score, on food intake. Parameter values were derived from data obtained with two of five treatment groups of an experiment where ewe lambs were fed either chopped hay or pelleted concentrates. The model predicted the intake of the remaining three treatment groups satisfactorily. The energy intake model was subsequently extended with a protein module based upon a Gompertz curve to simulate changes in body weight and condition score. The model predicted these changes satisfactorily for most treatment groups during the experimental period of 50 weeks. In a last test, the final body weights and body lipid contents of animals fed either hay or concentrates for a period of 3 years were predicted. The predictions for final body weight (77 or 118 kg) and lipid content in the empty body (26 or 58 %) were within the range of expectations for sheep with access to hay or concentrates, respectively. The biological implications of the hypothesis that body fatness acts upon voluntary intake via its effects on energetic efficiency are discussed.
High Noon on the Western Range: A Property Rights Analysis of the Johnson County War
Authors: McFerrin Randy , Wills Douglas
Published: March 2007

Wyoming's Johnson County War of 1892 is the historical basis of later popular depictions of the West as violent, and it influenced the development of Wyoming. Many see this era as the end of the open range system and the ascendancy of stock ranching and farming. Popular depiction argues that the event was an act of vigilantism of large foreign-owned firms against small individual settlers. We argue that the war was a conflict of property rights systems and use a model developed by Alston, Libecap, and Mueller to explain why violence broke out in Johnson County in 1892.

Richer (the Rancher): We made this country. Found it and we made it … Made a safe range out of this. Some us died doin' it. We made it. Then people move in who never held a rawhide through the old days. Fenced off my range. Fenced me off from water. Some of them like you paw ditches, and take out irrigation water, and so the creek runs dry sometimes, and I got to move my stock because of it. And you say we have no rights to the range.Stark (the Homesteader): You talk about rights. You think you got the right to say that nobody else has got any. Well, that ain't the way the government looks at it. Shane [Paramount Pictures, 1953]
Simple sequence repeat (SSR)-based diversity analysis of groundnut (Arachis hypogaea L.) germplasm resistant to bacterial wilt
Authors: Mace E. S. , Yuejin W. , Boshou L. , Upadhyaya H. , Chandra S. , Crouch J. H.
Published: March 2007

Groundnut is one of the most important oilseed crops in the world. Bacterial wilt, caused byRalstonia solanacearumE. F. Smith, is one of the major biotic constraints to groundnut production particularly in South-East Asia and East Africa. Several sources of resistance to bacterial wilt have been identified through field screening of groundnut germplasm. The aim of the present study was to quantify the genetic diversity among selected bacterial wilt-resistant lines, in comparison with the levels of variation observable within the cultivatedA. hypogaeagene pool. Thirty-two SSR markers were used to assess the degree of molecular polymorphism between 46 selected genotypes revealing 107 alleles, of which 101 (99.4%) were polymorphic with gene diversity scores ranging from 0.103 to 0.669, averaging 0.386. Cluster and multidimensional scaling analysis revealed two distinct groups within the germplasm broadly corresponding to the two subspecies (hypogaeaandfastigiata) ofA. hypogaea. However, accessions of varietiesperuvianaandaequatorianagrouped together with the varieties from subsp.hypogaea, rather than grouping with the other varieties of subsp.fastigiata.Analysis of molecular variance (AMOVA) revealed that 15% of the total observed variation was accounted for by disease response groups. This analysis will be useful in the selection of parental genotypes for mapping populations and breeding programmes attempting to broaden the genetic base of future groundnut cultivars. In particular, this opens up significant opportunities for the development of intraspecific mapping populations that will be highly relevant to modern groundnut breeding programmes.
Retrovirus‐Polymer Complexes: Study of the Factors Affecting the Dose Response of Transduction
Authors: Landázuri Natalia , Krishna Delfi , Gupta Monique , Doux Joseph M. Le
Published: March 2007

We have previously shown that complexes of Polybrene (PB), chondroitin sulfate C (CSC), and retrovirus transduce cells more efficiently than uncomplexed virus because the complexes are large and sediment, reaching the cells more rapidly than by diffusion. Transduction reaches a peak at equal weight concentrations of CSC and PB and declines when the dose of PB is higher or lower than CSC. We hypothesized that the nonlinear dose response of transduction was a complex function of the molecular characteristics of the polymers, cell viability, and the number of viruses incorporated into the complexes. To test this hypothesis, we formed complexes using an amphotropic retrovirus and several pairs of oppositely charged polymers and used them to transduce murine fibroblasts. We examined the effect of the type and concentration of polymers used on cell viability, the size and charge of the complexes, the number of viruses incorporated into the complexes, and virus binding and transduction. Transduction was enhanced (2.5‐ to 5.5‐fold) regardless of which polymers were used and was maximized when the number of positive charge groups was in slight excess (15–28%) of the number of negative charge groups. Higher doses of cationic polymer were cytotoxic, whereas complexes formed with lower doses were smaller, contained fewer viruses, and sedimented more slowly. These results show that the dose response of transduction by virus‐polymer complexes is nonlinear because excess cationic polymer is cytotoxic, whereas excess anionic polymer reduces the number of active viruses that are delivered to the cells.
Förderung von stotternden Kindern und Jugendlichen durch aktives Musizieren in einer Rock- und Pop-Band
Authors: Seidel Kerstin Martina
Published: March 2007

Zusammenfassung. Die Anwendung musikalischer Mittel zur Förderung des Lern- und Leistungsverhaltens sprachbehinderter Kinder und Jugendlicher eröffnet ein breites Spektrum an pädagogischen und therapeutischen Ansatzmöglichkeiten. Diese können nicht zuletzt auch an Förderschulen mit dem Schwerpunkt sprachliche Entwicklung umgesetzt werden. Durch die praktische Arbeit mit einer Schülergruppe werden konkrete musikimmanente Anwendungsmöglichkeiten zur Förderung von stotternden Kindern und Jugendlichen im Entwicklungsbereich Kommunikation und Sprache aufgezeigt. Die Förderinhalte beinhalten Angebote zum aktiven Musizieren und berücksichtigen insbesondere die kommunikativ-pragmatische Sprachebene.
Evolution of the accretion processes along the Mid‐Atlantic Ridge north of the Azores since 5.5 Ma: An insight into the interactions between the ridge and the plume
Authors: Maia Marcia , Goslin Jean , Gente Pascal
Published: March 2007

High‐resolution bathymetry and gravity data north of the Azores Plateau show that this part of the North Mid‐Atlantic Ridge is presently undergoing a phase of weak crustal production and magmatism. Most of the ridge segments are small and short‐lived, suggesting a disrupted and highly variable accretion regime since anomaly 3A. The influence of the nearby plume appears to be relatively minor and corresponds more to a weak thermal signal than to any major input of plume material and increased crustal production at the axis. A period of increased magmatism was identified at the southern limit of the study area (near 40°N) around anomaly 5. This magmatic “pulse” caused the emplacement of a topographic high, probably underlain by a thickened crust. This pulse probably marks the northernmost and last significant arrival of material from the Azores plume to the MAR axis.
Current amplification and magnetic reconnection at a three‐dimensional null point: Physical characteristics
Authors: Pontin D. I. , Galsgaard K.
Published: March 2007

The behavior of magnetic perturbations of an initially potential three‐dimensional equilibrium magnetic null point is investigated. The basic components which constitute a typical disturbance are taken to be rotations and shears, in line with previous work. The spine and fan of the null point (the field lines which asymptotically approach or recede from the null) are subjected to such rotational and shear perturbations, using three‐dimensional magnetohydrodynamic simulations. It is found that rotations of the fan plane and about the spine lead to current sheets which are spatially diffuse in at least one direction and form in the locations of the spine and fan. However, shearing perturbations lead to 3‐D‐localized current sheets focused at the null point itself. In addition, rotations are associated with a growth of current parallel to the spine, driving rotational flows and a type of rotational reconnection. Shears, on the other hand, cause a current through the null which is parallel to the fan plane and are associated with stagnation‐type flows and field line reconnection across both the spine and fan. The importance of the parallel electric field, and its meaning as a reconnection rate, are discussed.
Evaluation of Intergovernmental Panel on Climate Change Fourth Assessment soil moisture simulations for the second half of the twentieth century
Authors: Li Haibin , Robock Alan , Wild Martin
Published: March 2007

Soil moisture trends, particularly during the growing season, are an important possible consequence of global warming. Climate model simulations of future soil moisture changes should be made with models that can produce reliable simulations of soil moisture for past climate changes. In this paper, we compare soil moisture simulations from Intergovernmental Panel on Climate Change Fourth Assessment climate models forced with observed climate forcings for the past century, and evaluate them using in situ soil moisture measurements from over 140 stations or districts in midlatitudes of the Northern Hemisphere. To account for the observed spatial scale of soil moisture variations, we used regionally averaged soil moisture for six regions. The models showed realistic seasonal cycles for Ukraine, Russia, and Illinois, but generally poor seasonal cycles for Mongolia and China. To explore the summer drying issue for the second half of the 20th century, we analyzed the linear trend of soil moisture for Ukraine and Russia. Observations from both regions show increases in summer for the period from 1958–1999 that were larger than most trends in the model simulations. Only two out of 25 model realizations show trends comparable to those of observations. These two trends, however, are due to internal model variability rather than a result of external forcing. Changes in precipitation and temperature cannot fully explain soil moisture increases for Ukraine and Russia, which indicates that other factors might have played a dominant role on the observed patterns for soil moisture. We suggest that changes in solar irradiance (the dimming effect) and resultant changes in evaporative demand explain most of the observed soil moisture trends. To understand such sensitivity, we analyzed soil moisture outputs in a special version of the ECHAM5 model that was capable of capturing the observed radiation pattern as a result of incorporating a sophisticated aerosol scheme. Results suggest that both radiation and precipitation patterns are required to be adequately simulated to reproduce the observed soil moisture trends realistically.
Influence of nitrate radical on the oxidation of dimethyl sulfide in a polluted marine environment
Authors: Stark H. , Brown S. S. , Goldan P. D. , Aldener M. , Kuster W. C. , Jakoubek R. , Fehsenfeld F. C. , Meagher J. , Bates T. S. , Ravishankara A. R.
Published: March 2007

Simultaneous in situ measurements of dimethyl sulfide (DMS) and nitrate radical (NO3) from the NOAA research vessel Ronald H. Brown off the New England Coast during the summer of 2002 show a clear anticorrelation between these compounds. The anticorrelation indicates a strong interaction between anthropogenic NOx emissions and natural sulfur emissions from the ocean surface. The anticorrelation was invariant with the distance from the continent over the range sampled during this study. Diurnal averages showed maxima in DMS concentrations during dawn and dusk and a lower minimum of ≈30 pptv at night compared to the daytime minimum of ≈40 pptv, indicating a stronger oxidation by NO3 at night than by OH at daytime under polluted conditions. This conclusion is also supported by agreement between a box model calculation and the measurements. Including DMS oxidation by halogens (Cl and BrO) into the model improved the agreement significantly. Calculation of the relative DMS loss due to either NO3 or OH oxidation indicated that between 65 and 90% of the DMS oxidation was due to NO3, depending on NO3 mixing ratios. The area over which DMS oxidation by NO3 is at least as strong as by OH can extend as far as 3000 km from coastal anthropogenic NOx sources. These increased DMS oxidation rates by NO3 may have an impact on global non‐sea‐salt sulfate aerosol production, depending on the DMS chemical oxidation mechanism.
Solar radiation‐induced changes in ionospheric height and the Schumann resonance waveguide on different timescales
Authors: Williams E. R. , Sátori G.
Published: March 2007

This study draws together the available observations in the Schumann resonance frequency range to examine the general issue of sensitivity of ionospheric height variations to changes in ionizing radiation from the Sun on different timescales. Ionospheric height can be formally defined, and two characteristic heights are recognized in the Schumann resonance frequency range. In general, order of magnitude changes in radiation are needed to cause relative changes in ionospheric height as large as 10%, as is the case on both the diurnal and 11‐year timescales. Changes in EUV radiation are probably insufficiently strong to account for either the 27‐day or the 11‐year variation in ionospheric height. More ionization‐effective X radiation is needed, but much smaller height changes are expected on the solar rotation timescale because the variations in X radiation on this timescale are only tens of percent and not orders of magnitude. The annual variation in radiation from the Sun is only 7%, with an expected height variation less than 100 m, and this remains to be verified by observations. The general insensitivity of the Schumann resonance cavity to changes in ionizing radiation lends stability to the medium that is valuable toward quantifying absolute changes in the global lightning activity on various timescales within the cavity.
Evaluation of International Reference Ionosphere 2000 at a midlatitude station
Authors: Mansilla G. A.
Published: March 2007

To check the validity of the latest version of the International Reference Ionosphere (IRI‐2000), which contains geomagnetic activity dependence based on an empirical storm time ionospheric correction (STORM model), comparison of measuredfoF2values with those obtained from the model was made. To quantify the degree of accuracy of the IRI‐2000 model during disturbed conditions, the relative difference between the model outputs (with STORM model turned on and turned off options) and experimental data was calculated. The ionosondefoF2data used were obtained at Ebro Observatory (40.8°N, 0.49°E; geomagnetic latitude 43.2°N) during intense geomagnetic storms occurring in the years 2000 and 2001 (high solar activity). Although only a few case study comparisons have been made, the results show that during storm conditions, predicted values with the STORM model included in IRI‐2000 follow the variations offoF2data better than IRI‐2000 without the STORM model. In general, IRI‐2000 with the STORM model has almost 30–40% improvement over IRI‐2000 without the STORM model. The greater deviations between model outputs and observations are observed during the end of the main phase and early stage of the recovery phase. For this station, in general, IRI predictions with the STORM model underestimatefoF2data in February–March and significantly overestimate them in April–May.
Adrenomedullin Reduces Gender-Dependent Loss of Hypotensive Cerebrovasodilation after Newborn Brain Injury through Activation of ATP-Dependent K Channels
Authors: Armstead William M , Vavilala Monica S
Published: March 2007

Cerebrovascular dysregulation during hypotension occurs after fluid percussion brain injury (FPI) in the newborn pig owing to impaired K channel function. This study was designed to (1) determine the role of gender and K channel activation in adrenomedullin (ADM) cerebrovasodilation, (2) characterize the role of gender in the loss of hypotensive cerebrovasodilation after FPI, and (3) determine the role of gender in the ability of exogenous ADM to modulate hypotensive dysregulation after FPI. Lateral FPI (2 atm) was induced in newborn male and female newborn pigs (1 to 5 days old) equipped with a closed cranial window, n = 6 for each protocol. Adrenomedullin-induced pial artery dilation was significantly greater in female than male piglets and blocked by the KATP channel antagonist glibenclamide, but not by the Kca channel antagonist iberiotoxin. Cerebrospinal fluid ADM was increased from 3.8 ± 0.7 to 14.6 ± 3.0 fmol/mL after FPI in female but was unchanged in male piglets. Hypotensive pial artery dilation was blunted to a significantly greater degree in male versus female piglets after FPI. Topical pretreatment with a subthreshold vascular concentration of ADM (10−10 mol/L) before FPI reduced the loss of hypotensive pial artery dilation in both genders, but protection was significantly greater in male versus female piglets. These data show that hypotensive pial artery dilation is impaired after FPI in a gender-dependent manner. By unmasking a gender-dependent endogenous protectant, these data suggest novel gender-dependent approaches for clinical intervention in the treatment of perinatal traumatic brain injury.
Archaeological Chemistry
Authors: Pollard A Mark , Heron Carl , Gillard R D
Published: March 2007

The application of chemistry within archaeology is an important and fascinating area. It allows the archaeologist to answer such questions as "what is this artefact made of?", "where did it come from?" and "how has it been changed through burial in the ground?", providing pointers to the earliest history of mankind. Archaeological Chemistry begins with a brief description of the goals and history of archaeological science, and the place of chemistry within it. It sets out the most widely used analytical techniques in archaeology and compares them in the light of relevant applications. The book includes an analysis of several specific archaeological investigations in which chemistry has been employed in tracing the origins of or in preserving artefacts. The choice of these investigations conforms to themes based on analytical techniques, and includes chapters on obsidian, ceramics, glass, metals and resins. Finally, it suggests a future role for chemical and biochemical applications in archaeology. Archaeological Chemistry enables scientists to tackle the fundamental issues of chemical change in the archaeological materials, in order to advance the study of the past. It will prove an essential companion to students in archaeological science and chemistry, field and museum archaeologists, and all those involved in conserving human artefacts.
PI3K signalling during influenza A virus infections
Authors: Hale B.G. , Randall R.E.
Published: March 2007

Recent work has demonstrated that the PI3K (phosphoinositide 3-kinase) signalling pathway is important for efficient influenza A virus replication. Activation of PI3K in virus-infected cells is mediated by the viral NS1 protein, which binds directly to the p85β regulatory subunit of PI3K and causes the PI3K-dependent phosphorylation of Akt (protein kinase B). Given that recombinant influenza A viruses unable to activate PI3K signalling are attenuated in tissue culture, the PI3K pathway could be a novel target for the development of future anti-influenza drugs.
Metabolic switching of PI3K-dependent lipid signals
Authors: Downes C.P. , Leslie N.R. , Batty I.H. , van der Kaay J.
Published: March 2007

The lipid phosphatase, PTEN (phosphatase and tensin homologue deleted on chromosome 10), is the product of a major tumour suppressor gene that antagonizes PI3K (phosphoinositide 3-kinase) signalling by dephosphorylating the 3-position of the inositol ring of PtdIns(3,4,5)P3. PtdIns(3,4,5)P3 is also metabolized by removal of the 5-phosphate catalysed by a distinct family of enzymes exemplified by SHIP1 [SH2 (Src homology 2)-containing inositol phosphatase 1] and SHIP2. Mouse knockout studies, however, suggest that PTEN and SHIP2 have profoundly different biological functions. One important reason for this is likely to be that SHIP2 exists in a relatively inactive state until cells are exposed to growth factors or other stimuli. Hence, regulation of SHIP2 is geared towards stimulus dependent antagonism of PI3K signalling. PTEN, on the other hand, appears to be active in unstimulated cells and functions to maintain basal PtdIns(3,4,5)P3 levels below the critical signalling threshold. We suggest that concomitant inhibition of cysteine-dependent phosphatases, such as PTEN, with activation of SHIP2 functions as a metabolic switch to regulate independently the relative levels of PtdIns(3,4,5)P3 and PtdIns(3,4)P2.