bluuebunny/crossref_metadata_2025 huggingface dataset:
The δ13C value of ruminant saliva and its effect on the estimation of the legume component of oesophageal extrusa samples
Authors: Jones R. J. , Lefeuvre R. P.
Published: March 2009

The C3 and C4 plant components in extrusa samples from oesophageally fistulated cattle can be estimated by δ13Canalysis. However, contamination with saliva containing bicarbonates could cause bias in the estimation of the C3 or C4 components. Saliva from animals fed C4 and C3 diets had δ13C values of – 4.37/103 and –15.97/103, respectively. Both values showed a large positive shift of c. 10 units relative to the diets, but the difference between feeds was maintained in the saliva. On theoretical grounds, contamination of the ingested feed with saliva should have caused a small (1·3–3·4% legume) negative bias when estimating legume percentage in the diet. This did not occur when saliva of known (PC was added to mixtures of C3 and C4 forages which were dried, ground and analysed for δ13C. It is postulated that CO2 was lost from bicarbonate when saliva was dried in contact with fresh plant material, and so no significant bias was detected. It would appear that the δ13C technique can be used to estimate the proportion of C3 and C4 components in oesophageal extrusa samples without significant bias from salivary contamination.
Phosphorus diffusion in soils in relation to some edaphic factors and its influence on P uptake by maize and wheat
Authors: Bahl G. S. , Singh N. T.
Published: March 2009

Laboratory studies were conducted on four soils to ascertain the effect of P content and texture on the capacity factor (P buffering capacity) of soils and in turn the effect of these factors combined with moisture content of soil on the diffusion coefficient of P (Dp). A glasshouse experiment was conducted to study the relationship of Dp with P uptake by maize and wheat. The buffer capacity decreased by the application of P in all four soils. There was a significant negative correlation between buffer capacity and Olsen's extractable P but positive correlation with other soil factors. The relative influence of different soil variables on the buffer capacity was in the order: free iron > percentage clay > exchangeable aluminium. The Dp value increased significantly with applied P, the maximum (3·2-fold over control) being in Tolewal loamy sand. The increase in clay and moisture content of soil also increased the Dp value. The drymatter yield and P uptake was significantly correlated with Dp, the r value being higher at later stages of growth of maize and wheat.
Effect of row orientation on growth, yield and yield attributes of wheat sown on three dates
Authors: Dhingra K. K. , Dhillon M. S. , Grewal D. S. , Sharma K.
Published: March 2009

An experiment to study the effect of row direction on the light interception, growth and yield of three wheat cultivars sown at three different dates was conducted at Punjab Agricultural University, Ludhiana during rabi seasons 1982–3 and 1983–4. The results showed that sowing in a north-south direction resulted in 0·20 and 0·22 t/ha higher yield than sowing east-west. Bi-directional sowing gave further increases of 0·30 and 0·18 t/ha over north-south direction during 1982–3 and 1983–4 respectively. Late sowing significantly reduced yield.
Comparison of pods of the terminal raceme of rapeseed (Brassica campestris var. Yellow Sarson) and mustard (Brassica juncea) cultivars
Authors: Chauhan Y. S. , Bhargava S. C.
Published: March 2009

Rapeseed and mustard cultivars aro morphologically determinate but the growth of the raceme, which is a corymbose type, is indeterminate. On the raceme flower opening proceeds acropetally in a sequential manner with one or two flowers opening each day. Thus there is a considerable time lag between first and last flower opening within the same raceme. In these oil-seed crops, besides leaves both pod wall and stems are photosynthetically active and the share of assimilates contributed by these three organs to the growing seeds has been estimated to be 37, 32 and 31%, respectively (Brar & Thies, 1977). A rapid decline in leaf area during pod filling in rapeseed and mustard (Chauhan & Bhargava, 1984) and rape (Allen & Morgan, 1972) cultivars has been observed. The assimilate supply to the pods developing at different periods may, therefore, differ owing to a decline in the leaf source as well as increasing intornal competition between pods. In winter oil-seed rape (Brassica napus), both mutual competition for assimilates and shading resulting from excessive pod production have been reported to cause heavy seed and pod losses (Mendham, Shipway & Scott, 1981). No information is available for rapeseed and mustard cultivars on how different components of the pod, such as its weight, seed weight, number of seeds and seed oil percentage, change according to their position on the terminal raceme. This information may be useful in deciding the appropriate number of pods on a raceme for optimum yield.
Inheritance of seed yield, maturity and seed weight of common bean (Phaseolus vulgaris) under semi-arid rainfed conditions
Authors: White J. W. , Ochoa R. M. , Ibarra F. P. , Singh S. P.
Published: March 2009

To develop an effective breeding programme for rainfed production of the common bean (Phaseolus vulgaris L.), the inheritance of seed yield under such conditions should be understood, preferably considering the effects of environment to account for site or season specificity. Thus, heritability, expected and realized gain from selection, and combining ability were evaluated for a nine-parent diallel of common bean without reciprocals but including parents, at two locations each in Mexico and Colombia, using the F2 and F3 population bulks. Heritability estimated from regressions of F3 on F2 ranged from 0·09 ± 0·18 (S.E.) to 0·75±0·25 for seed yield, from 0·26±009 to 0·34±009 for days to maturity and from0·57±004 to 0·80±004 for 100-seed weight. Expected gain from selection in the F2 was estimated as a percentage of the population mean, selecting the upper 20% of the populations. Expected gain in seed yield ranged from 1·8 to 8·4% in Mexico and from 6·5 to 28·1% in Colombia. Realized gains in seed yield in the F3 were 0·4–7·4% in Mexico and 2·9–15·7% in Colombia. Realized gain values for days to maturity were < 2·2%, and for 100-seed weight > 13·4%. General combining ability (GCA) mean squares (estimated using Griffing's Method 2, Model 1) were significant (P <0·01) and larger than those for specific combining ability (SCA) for all traits at all locations. The parents from the Mexican highlands tended to have a positive GCA effect for yield in Mexico but negative values in Colombia, whereas parents adapted to mid-elevation tropical environments showed the opposite tendency. However, all significant GCA values of breeding line V8025 were positive in both countries.
Long-term effects of primary cultivations on crop yields in a four-course rotation
Authors: Allen E. J. , Barker M. G.
Published: March 2009

An experiment is described which investigated for a period of 12 years the effects of four methods of basic cultivation – ploughing, rotary cultivating, cultivating and discing – on crop yields in a four-course rotation of winter wheat, sugar beet, spring barley followed by either potatoes (on one half of each main plot) or ley (on the other). The cultivations were carried out at two different times and each crop was grown at two levels of fertilizer.

The method of cultivation had no effect on the yield of barley when weeds were controlled by chemicals but, in the absence of such control, the three deeper working methods of cultivation gave higher yields than discing towards the end of the experiment. In the case of wheat, ploughing generally led to the highest yields and rotary cultivating led to higher yields than either cultivating or discing after the ley. Discing led to relatively low yields, particularly with cultural methods of weed control at the lower level of fertility.

With the sugar-beet crop, yields of sugar were higher in all rotations after ploughing than after cultivating or discing, irrespective of the method of weed control and although yields after rotary cultivating were similar to those after ploughing in the second rotation they did not consistently exceed those after cultivating or discing in the other two rotations. With discing, in the absence of chemical weed control the yields were markedly reduced in the last rotation period. Ploughing also led to the highest yields of potatoes but there were no consistent differences between the other methods and an apparent trend to lower yields after discing in the absence of chemical methods of weed control had not reached significance by the end of the experiment.

It was concluded that ploughing was a more reliable method of seedbed preparation, not only with regard to consistency of performance under different conditions but also with regard to depth of working and extent of weed control.

Ploughing appeared to be of particular value with the root crops used but the other methods led to satisfactory yields of the cereals grown after roots.
The sodium requirements of beef calves for growth
Authors: Morris J. G. , Murphy G. W.
Published: March 2009

Thirty-two beef calves (mean body weight 79 kg) were given a ration which depleted their body reserves of Na as was evidenced by a narrow Na to K ratio in the parotid saliva. Eight calves were then assigned to each of the following four treatments: low Na basal ration alone, basal ration plus either 1·09, 2·19 or 3·28 g Na/calf/day as bicarbonate.
Effects of dietary deficiencies of energy, protein and calcium on the pregnant ewe. I. Body composition and mineral content of the ewes
Authors: Sykes A. R. , Field A. C.
Published: March 2009

Forty 6½-year-old Scottish Blackface ewes were used in an experiment to investigate the effects of low protein and low calcium (Ca) intakes during pregnancy on body composition and mineral contents. Six sheep were slaughtered at the commencement of the experiment as controls; 28 were used in a 2 × 2 factorial experiment in which semipurified diets containing 11·8 and 6·0% crude protein (CP) and 1·2 and 0·11% Ca in the dry matter were offered to maintain non-esterified fatty acids (NEFA) and ketone bodies in the plasma at levels comparable to those found in hill sheep in winter. All ewes were slaughtered after parturition and the carcase dissected into soft tissue and skeleton fractions. Both fractions were dissolved in HNO3and the fat and mineral contents measured.
Performance of laying hens fed on diets containing heat-treated beans (Vicia faba L. var. minor), cotyledons and hulls
Authors: Olaboro G. , Campbell L. D. , Marquardt R. R.
Published: March 2009

Two experiments were conducted to study the influence of heat treatment of Vicia faba beans on the productive performance of laying hens fed diets containing large proportions of the beans. In the first experiment, the effects of extruding and pelleting the beans were studied while in the second experiment the effects of autoclaving at 121 °C for 30 min the cotyledons and hulls of the beans were evaluated. Hyline-W36 layers were used in the first experiment while two strains (Shaver-288 and Dekalb) of birds were used in the second experiment. Each experiment lasted 5 months during which data on egg production, egg weight, feed intake, mortality and body-weight gain of birds were collected. The results obtained indicated that heat treatment (extruding, pelleting and autoclaving) of the beans, cotyledons and hulls had no beneficial effect on the productive performance of laying hens fed on diets containing large proportions of the heated beans, cotyledons and hulls. Egg-size reducing factors appeared to be concentrated in the cotyledons rather than the hulls of the beans.
The effect of growing clover cultivars in association with barley cultivars upon grain yield of the barley crop in the year of sowing and the subsequent year
Authors: Stewart R. H. , Lynch K. W. , White Ethel M.
Published: March 2009

In 1974 three cultivars of barley of different straw lengths, Mazurka, Julia and Midas, were grown alone and with each of four cultivars of red and two of white clover in a split-plot randomized-block experiment of four replications. Although the barley cultivars differed significantly in yield the barley x clover interaction was not significant and yield of grain was not affected by the presence of the clovers.

In the following year the entire experimental area was sown with Mazurka barley. Significantly higher grain yields were obtained on those plots sown with clover in 1974 than in plots where no clover had been sown. In no case was the combined yield of barley from the 2 years on any treatment involving clover lower than that of the mean of the no-clover control plots, although the highest increase in yield, 11% from the S.123 red clover treatment, over the no-clover control was not shown to be significant.
Growth, oscillation and collapse of vortex cavitation bubbles
Authors: CHOI JAEHYUG , HSIAO CHAO-TSUNG , CHAHINE GEORGES , CECCIO STEVEN
Published: March 2009

The growth, oscillation and collapse of vortex cavitation bubbles are examined using both two- and three-dimensional numerical models. As the bubble changes volume within the core of the vortex, the vorticity distribution of the surrounding flow is modified, which then changes the pressures at the bubble interface. This interaction can be complex. In the case of cylindrical cavitation bubbles, the bubble radius will oscillate as the bubble grows or collapses. The period of this oscillation is of the order of the vortex time scale, τV= 2πrc/uθ,max, wherercis the vortex core radius anduθ,maxis its maximum tangential velocity. However, the period, oscillation amplitude and final bubble radius are sensitive to variations in the vortex properties and the rate and magnitude of the pressure reduction or increase. The growth and collapse of three-dimensional bubbles are reminiscent of the two-dimensional bubble dynamics. But, the axial and radial growth of the vortex bubbles are often strongly coupled, especially near the axial extents of the bubble. As an initially spherical nucleus grows into an elongated bubble, it may take on complex shapes and have volume oscillations that also scale with τV. Axial flow produced at the ends of the bubble can produce local pinching and fission of the elongated bubble. Again, small changes in flow parameters can result in substantial changes to the detailed volume history of the bubbles.
Bragg resonance of waves in a two-layer fluid propagating over bottom ripples. Part I. Perturbation analysis
Authors: ALAM MOHAMMAD-REZA , LIU YUMING , YUE DICK K. P.
Published: March 2009

We investigate, via perturbation analyses, the mechanisms of nonlinear resonant interaction of surface-interfacial waves with a rippled bottom in a two-layer density-stratified fluid. As in a one-layer fluid, three classes of Bragg resonances are found to exist if nonlinear interactions up to the third order in the wave/ripple steepness are considered. As expected, the wave system associated with the resonances is more complicated than that in a one-layer fluid. Depending on the specifics of the resonance condition, the resonance-generated wave may be a surface or internal mode and may be transmitted or reflected. At the second order, class I Bragg resonance occurs involving two surface and/or internal waves and one bottom-ripple component. The interaction of an incident surface/internal wave with the bottom ripple generates a new surface or internal wave that may propagate in the same or the opposite direction as the incident wave. At the third order, class II and III Bragg resonances occur involving resonant interactions of four wave/ripple components: two surface and/or internal waves and two bottom-ripple components for class II resonance; three surface and/or internal waves and one bottom-ripple components for class III resonance. As in class I resonance, the resonance-generated wave in class II resonance has the same frequency as that of the incident wave. For class III resonance, the frequency of the resonant wave is equal to the sum or difference of the two incident wave frequencies. We enumerate and represent, using Feynman-like diagrams, the possible cases and combinations for Bragg resonance up to the third order (in two dimensions). Analytical regular perturbation results are obtained and discussed for all three classes of Bragg resonances. These are valid for limited bottom patch lengths and initial/finite growth of the resonant waves. For long bottom patches, a uniformly valid solution using multiple scales is derived for class I resonance. A number of applications underscoring the importance and implication of these nonlinear resonances on the evolution of ocean waves are presented and discussed. For example, it is shown that three internal/surface waves co-propagating over bottom topography are resonant under a broad range of Bragg conditions. The present study provides the theoretical basis and understanding for the companion paper (Alam, Liu & Yue 2008), where a direct numerical solution for the general nonlinear problem is pursued.
Beijing's Olympic Education Programme: Re-Thinking Suzhi Education, Re-Imagining an International China
Authors: Brownell Susan
Published: March 2009

Starting in 2005, the largest “Olympic education” programme ever implemented by an Olympic host country was carried out in schools in Beijing and across China. By looking at the ways in which the policies for this programme were created and implemented, this article challenges the common perception that there was a “master plan” surrounding all aspects of the Beijing Olympics that was imposed by the party-state from the top down with the singular goal of promoting nationalist and communist ideology. It makes the point that by contrast with the suzhi (“quality”) education that preceded it, Olympic education contained a de-politicized patriotic education that linked national identity with sports heroes rather than political systems, and re-situated Chinese national identity within an international community in which it would now take its place as an equal partner.
Personality Differences in Emotions
Authors: Ng Weiting , Diener Ed
Published: March 2009

In Study 1, individuals high in neuroticism (high N) felt more negative and experienced less decrease of their negative emotions than individuals low in Neuroticism (low N) when extremely unpleasant hypothetical scenarios improved. Study 2 also found that high N individuals felt more negative than low N in a slightly unpleasant laboratory situation, and that individuals high in Extraversion (high E) felt more positive than individuals low in Extraversion (low E) in a slightly pleasant laboratory situation. The present studies also confirmed that high N individuals were less likely to repair negative emotions than low N, and high E individuals were more likely to savor positive emotions than low E. These attempts at negative and positive emotion regulation predicted negative and positive emotional reactions, respectively, and accounted for the trait differences in emotions. Hence, there is evidence that differences in negative emotion regulation mediated the relation between Neuroticism and negative emotions, and differences in positive emotion regulation mediated the relation between Extraversion and positive emotions.
The Influence of Emotional Intelligence and Affectivity on Emotional Labor Strategies at Work
Authors: Cheung Francis Yue-lok , Tang Catherine So-kum
Published: March 2009

We investigated how affectivity and emotional intelligence (EI) influence the use of emotional labor strategies at work among 486 Chinese employees. Hierarchical regression analyses showed that negative affectivity was a significant correlate for surface acting, while EI was a significant correlate for both deep acting and expression of naturally felt emotion. Positive affectivity and EI interacted with each other to influence the adoption of various emotional labor strategies. For instance, individuals with positive affectivity and regulation of emotion, a key facet of EI, tended to use more deep acting and the expression of naturally felt emotion but less surface acting than employees who were low in regulation of emotion. Furthermore, mediation analyses revealed that EI was a mediator between positive affectivity and deep acting. We discussed limitations as well as practical and research implications of findings.
Altered oceanic crust as an inorganic record of paleoseawater Sr concentration
Authors: Coogan Laurence A.
Published: March 2009

The minimum Sr content of seawater at 90–95 Ma is determined from the Sr content and Sr isotopic composition of the sheeted dike complex of oceanic crust that was hydrothermally altered at this time on the basis of simple mass and heat balances. When this approach is applied to sheeted dike complexes that were hydrothermally altered by modern seawater a minimum fluid Sr content of <3 μg g−1 is calculated. This is substantially less than the modern ocean Sr content of ∼7.8 μg g−1 supporting the arguments that the approach provides a robust minimum Sr content of the ocean at the time of crust formation. Applying the same approach to the sheeted dike complexes in the Cretaceous Troodos and Oman ophiolites gives minimum Sr contents for the ocean at this time of 27 and 38 μg g−1, respectively. These values are consistent with previous studies of biomineralized carbonate that suggest higher Sr/Ca in seawater at this time and fluid inclusion analyses that suggest higher Ca contents in the ocean at this time. The Ca content of the ocean must have been at the upper end of the range suggested by fluid inclusion analyses (≥30 mmol kg−1). The high Ca and Sr content of seawater at 90–95 Ma was, at least partially, due to enhanced submarine hydrothermal circulation which leaches Sr from the basaltic crust because it coincides with a time of low seawater 87Sr/86Sr. Elevated Sr contents at this time may have impacted the evolution and/or biogeochemical role of the Acantharians which secrete a SrSO4 skeleton.
Shock front nonstationarity and ion acceleration in supercritical perpendicular shocks
Authors: Yang Z. W. , Lu Q. M. , Lembège B. , Wang S.
Published: March 2009

Previous particle‐in‐cell simulations have evidenced that quasiperpendicular shocks are nonstationary and suffer a self‐reformation on gyro scale of the incoming ions due to the accumulation of reflected ions. In this paper, by separating the incoming ions into reflected and directly transmitted parts, we investigate the detailed mechanisms of ion acceleration in a nonstationary perpendicular shock. Test particle simulations are performed where the shock profiles are issued from self‐consistent one‐dimensional full particle‐in‐cell simulations. Both shell and Maxwellian incoming ion distributions are used. In both cases, most energetic particles correspond to reflected ions, and the associated acceleration mechanisms include both shock drift acceleration (SDA) and shock surfing acceleration (SSA). Two types of results are obtained. First, if we fix the shock profiles at different times within a self‐reformation cycle, the mechanisms of particle acceleration are different at different profiles. SDA process appears as the dominant acceleration mechanism when the width of the ramp is broad (and overshoot amplitude is low) whereas both SDA and SSA contribute as the width of the ramp is narrow (and overshoot amplitude is high). For the different shock profiles concerned herein, SDA process is more efficient (higher resulting ion energy gain) than the SSA process. Second, in order to investigate ion acceleration in self‐reforming shocks, not only the ramp but also the variations of the whole shock front need to be included. In the continuously time‐evolving shock, SDA remains a dominant acceleration mechanism whereas SSA mechanism becomes more and more important with the increase of the initial particle energy. The percentage of reflected ions cyclically varies in time with a period equal to the self reformation cycle, which is in agreement with previous full particle simulations. The reflected ions not only come from the distribution wings of the incoming ions but also from the core part, in contrast with previous results based on stationary shocks.
Permafrost and climate change at Herschel Island (Qikiqtaruq), Yukon Territory, Canada
Authors: Burn C. R. , Zhang Y.
Published: March 2009

Herschel Island, in the southern Beaufort Sea, is dominantly a glacier ice thrust feature composed of ice‐rich, perennially frozen sediments. Climate data are available for Herschel Island from 1899 to 1905 and 1995–2006. Air temperatures at Herschel Island are similar to sites on the adjacent mainland. Late winter snow depth is only about 20 cm, or half the depth on the mainland, and local topography defines the sites of annually recurring snowdrifts. Near‐surface ground temperatures, thaw depths, and ground ice contents have been investigated over a 750‐m transect leading up Collinson Head, the easternmost part of the island. The ground temperature profile to 42‐m depth indicates recent warming of permafrost because the temperature decreases with depth. The temperature at 15‐m depth is −8.0°C, the same as the annual mean temperature at 1‐m depth at windswept sites along the transect. A simulation of the ground thermal regime, calibrated with local ground properties, equilibrated with the climate of 1899–1905, and driven by the climate of the region during the 20th century reproduces the present ground temperature profile and the annual temperature cycle for 1‐m depth at windswept sites. The model indicates that the mean annual temperatures at the top of permafrost and at 20‐m depth have increased by 2.6 and 1.9°C, respectively, since 1899–1905, and the perturbation in ground temperature has reached about 120‐m depth. Active layer thickness measured in the terrain types studied on Herschel Island is about 55 cm, 15 to 25 cm greater than field data from these units collected in 1985.
The 1F7 idiotype is selectively expressed on CD5+ B cells and elevated in chronic hepatitis C virus infection
Authors: Davtyan Tigran K , Hovsepyan Marine P , Mkhitaryan Levon M , Hakobyan Gagik S , Brazil Aiden , Barrett Lisa , Hirsch Geri , Peltekian Kevork M , Grant Michael D
Published: March 2009

Antibodies against different chronic viruses, including hepatitis C virus (HCV), express a public cross‐reactive idiotype (Id) designated as 1F7. The prominence of this Id may reflect selective engagement of B1 B cells by chronic pathogens. We investigated this by comparing 1F7 Id expression on CD5+ and CD5− B cells, total IgG, total IgM and anti‐HCV core antibodies in different HCV exposure settings. By flow cytometry, we observed a selective increase in 1F7 Id+CD5+ B cells in chronic HCV infection. 1F7 Id levels in different immunoglobulin compartments were measured by enzyme‐linked immunosorbent assay. 1F7 Id expression was prominent in anti‐HCV core antibodies of ∼90% of 141 HCV‐exposed individuals tested. In the Canadian and Armenian study groups, participants who spontaneously cleared HCV infection had lower median 1F7 Id levels on total plasma IgG and anti‐HCV core antibodies. Armenian spontaneous clearers, who were younger and more recently infected than their Canadian counterparts, also had had lower median 1F7 Id levels on total plasma IgM. Engagement by HCV of B‐cell receptors within, or overlapping with the CD5+ B1 B‐cell repertoire is reflected in the production of 1F7 Id+ anti‐HCV antibodies and expansion of 1F7 Id+CD5+ B cells. Higher 1F7 Id expression levels are associated with chronic infection.
Asymmetric development of Cotyledons of Tomato Embryo: Testing the prediction of Self-Organization
Authors: Reddy Chalapathy
Published: March 2009

Developmental biologists have long strived to understand how organisms acquire shape and form. The architecture of the mature plant is established during embryogenesis. They have learned much about how gene expression controls the specification of cell type and about how cells interact with one another to coordinate such specific decisions. Far less is known about autocatalytic feedback flow of resource molecules regulating a plant and its parts, shape and form. Indeed, it has even been proposed that the development of shape is not under genetic control but rather is determined by physical forces. Asymmetric development of sinks that depend on common resource pool has been viewed as a consequence of autocatalytic feedback process of flow of resource units into them. The feedback process implies that the stronger a sink is relative to its competitors, the greater is its probability of getting further resources as a non-linear function of its resource drawing ability and sink size. We have shown that this model contrasts with that of sink strength dependent model in its prediction of the subsequent development of the initial asymmetry of growing cotyledons of the tomato embryo (Lycopersicon esculentum L.), when their resource drawing ability is enhanced by exogenous application of the growth regulators (NAA, GA and BA), we test these prediction and show that the results are in conformity with the autocatalytic model proposed by Ganeshaiah and Uma Shaanker.
Long-term portal hypertension increases the vasodilator response to acetylcholine in rat aorta: role of prostaglandin I2
Authors: Blanco-Rivero Javier , Aller Ma Angeles , Arias Jaime , Ferrer Mercedes , Balfagón Gloria
Published: March 2009

In the present study, we have analysed both the effect of long-term portal hypertension on the vasomotor response to acetylcholine in rat aorta and the mechanism involved in this response. For this purpose, sham-operated rats and rats with pre-hepatic PH (portal hypertension; triple partial portal vein ligation) were used at 21 months after surgery. The participation of NO and COX (cyclo-oxygenase) derivatives in the vasodilator response elicited by acetylcholine after incubation with L-NAME (NG-nitro-L-arginine methyl ester), indomethacin, SC-560, NS-398, tranylcypromine and furegrelate, was analysed. NO, TXB2 (thromboxane B2) and 6-keto PGF1α (prostaglandin F1α) release were measured. In addition, SNP (sodium nitroprusside), U-46619, PGI2 and forskolin vasomotor responses were analysed. COX-1 and COX-2 expression was also determined. The acetylcholine-induced vasodilating response was higher in rats with PH. TXA2 and NO release, and SNP and U-46619 sensitivity were similar in both groups. PGI2 release was not modified by portal hypertension, but vasodilator responses to this prostanoid and to forskolin were higher in rats with PH. COX-1 and COX-2 expression remained unmodified by surgery. In conclusion, increased vasodilation to acetylcholine is maintained in long-term PH. Although the participation of endothelial NO remained unmodified, the COX-2 derivative PGI2 does participate through an increased vasodilator response.
Making a Broader Case for the Narrow View: Where to Begin?
Authors: Wallach Geraldine P. , Charlton Stephen , Christie Julie
Published: March 2009

Purpose

This final article covering the topic of the interplay between decoding, comprehension, and content versus structure knowledge describes a set of language initiatives that are focused toward content area learning. Inspired by the work of their colleagues from diverse fields and their own work, the authors offer suggestions to clinicians who are interested in creating and delivering curriculum-relevant and strategic-based language intervention to school-age students with language learning disabilities (LLD).

Method

The discussion covers selected topics that form the foundation for an evolving intervention framework, including (a) understanding the content and structural requirements of textbooks, (b) integrating metacognitive and metalinguistic techniques into intervention goals and objectives, and (c) emphasizing meaning-based activities that cut across connected discourse (macrostructure levels) and sentence/word components (microstructure levels) of spoken and written language.

Conclusion

Starting with ways to find clues about “what to do” with students by looking in their textbooks, the authors continue with examples that integrate content and structure knowledge using social studies and science as backdrops for language intervention. The article ends with a reminder to clinicians to consider ways that preschool language intervention can be more effective in helping children prepare for the academic demands of the future.
Large magnetic entropy change with small thermal hysteresis near room temperature in metamagnetic alloys Ni51Mn49−xInx
Authors: Hu F. X. , Wang J. , Shen J. , Gao B. , Sun J. R. , Shen B. G.
Published: March 2009

Magnetic properties and magnetic entropy change ΔS have been investigated in Heusler alloys Ni51Mn49−xInx (x=15.6, 16.0, and 16.2). By tuning Ni, Mn, and In contents around composition Ni50Mn34In16, large ΔS with small thermal hysteresis near room temperature can be achieved. Martensitic temperature Tm shifts from 308 K to 253 K with x varying from 15.6 to 16.2. The thermal hysteresis around Tm is small, <2 K, for all samples. Because of the fundamental difference in magnetization around Tm, an external magnetic field induces a metamagnetic transition from the martensitic to the austenitic state. As a result, a large magnetic entropy change with positive sign appears in a wide temperature range. The size of ΔS reaches 19, 20, and 33 J/kg K under 5 T magnetic field at 253, 262, and 308 K for samples x=15.6, 16.0, and 16.2, respectively.
An efficient algorithm for computing the Baker–Campbell–Hausdorff series and some of its applications
Authors: Casas Fernando , Murua Ander
Published: March 2009

We provide a new algorithm for generating the Baker–Campbell–Hausdorff (BCH) series Z=log(eXeY) in an arbitrary generalized Hall basis of the free Lie algebra L(X,Y) generated by X and Y. It is based on the close relationship of L(X,Y) with a Lie algebraic structure of labeled rooted trees. With this algorithm, the computation of the BCH series up to degree of 20 [111 013 independent elements in L(X,Y)] takes less than 15min on a personal computer and requires 1.5Gbytes of memory. We also address the issue of the convergence of the series, providing an optimal convergence domain when X and Y are real or complex matrices.
The von Kármán Sodium experiment: Turbulent dynamical dynamos
Authors: Monchaux Romain , Berhanu Michael , Aumaître Sébastien , Chiffaudel Arnaud , Daviaud François , Dubrulle Bérengère , Ravelet Florent , Fauve Stephan , Mordant Nicolas , Pétrélis François , Bourgoin Mickael , Odier Philippe , Pinton Jean-François , Plihon Nicolas , Volk Romain
Published: March 2009

The von Kármán Sodium (VKS) experiment studies dynamo action in the flow generated inside a cylinder filled with liquid sodium by the rotation of coaxial impellers (the von Kármán geometry). We first report observations related to the self-generation of a stationary dynamo when the flow forcing is Rπ-symmetric, i.e., when the impellers rotate in opposite directions at equal angular velocities. The bifurcation is found to be supercritical with a neutral mode whose geometry is predominantly axisymmetric. We then report the different dynamical dynamo regimes observed when the flow forcing is not symmetric, including magnetic field reversals. We finally show that these dynamics display characteristic features of low dimensional dynamical systems despite the high degree of turbulence in the flow.
Can existing models qualitatively describe the mixing behavior of acetone with water?
Authors: Jedlovszky Pál , Idrissi Abdenacer , Jancsó Gábor
Published: March 2009

The Helmholtz free energy of neat water, neat acetone, and acetone-water mixtures of various compositions covering the acetone mole fraction range of 0.02–0.26 is calculated at 300 K by computer simulation using the method of thermodynamic integration. In the calculations the mixtures of Kirkwood–Buff force field (KBFF) acetone with both TIP4P and SPC/E water are considered. The Helmholtz free energy of mixing calculated from the free energy difference of the mixture and of the two neat phases is found to be positive at each composition considered, indicating that the studied systems are thermodynamically unstable. The range of immiscibility is estimated to extend from the acetone mole fraction value below 0.01 to about 0.28 for both model pairs. Since a previous investigation [A. Perera and F. Sokolić, J. Chem. Phys. 121, 11272 (2004)] showed that, with the exception of SPC/E water and KBFF acetone, acetone-water model pairs exhibit demixing behavior, the present result points out that currently no existing acetone model can qualitatively reproduce the phase behavior of acetone-water mixtures, i.e., the well known experimental fact that acetone is miscible with water in any proportion.
Half-metallic electronic structure of Co2MnSi electrodes in fully epitaxial Co2MnSi/MgO/Co2MnSi magnetic tunnel junctions investigated by tunneling spectroscopy (invited)
Authors: Ishikawa Takayuki , Itabashi Naoki , Taira Tomoyuki , Matsuda Ken-ichi , Uemura Tetsuya , Yamamoto Masafumi
Published: March 2009

We used tunneling spectroscopy to examine the spin-dependent electronic structure of Co2MnSi (CMS) electrodes facing a MgO barrier and the key tunneling mechanism in fully epitaxial CMS/MgO/CMS magnetic tunnel junctions (MTJs) that showed high tunnel magnetoresistance ratios up to 182% at room temperature and 705% at 4.2 K. Consequently, we developed a model of the spin-dependent electronic structure for CMS electrodes and a tunneling model that can consistently explain the observed tunneling spectra. Here, we show that lower (upper) CMS electrodes possess a half-metal gap of 0.40 eV (0.32 eV) with the Fermi level (EF) near the middle of the half-metal gap for both lower and upper CMS electrodes. Furthermore, we found strong evidence for the existence of interface states in the interfacial region of CMS electrodes facing a MgO barrier, as well as evidence of residual states in the bulk region of upper CMS electrodes, in both cases for minority spins around EF, and we show that interface states play a critical role for spin-dependent tunneling in these half-metallic CMS-based MTJs.
Quadratic Lie algebras and quasiexact solvability of the two-photon Rabi Hamiltonian
Authors: Dolya S. N.
Published: March 2009

It is proved that the two-photon Rabi Hamiltonian is quasiexactly solvable on the basis of the two different quadratic Lie algebras.
Systematics and phylogeny of a new cryptic species of Diloma Philippi (Mollusca: Gastropoda: Trochidae) from a novel habitat, the bull kelp holdfast communities of southern New Zealand
Authors: Spencer Hamish G. , Marshall Bruce A. , Waters Jonathan M.
Published: March 2009

The seven currently recognised New Zealand species in the gastropod genus Diloma Philippi, 1845 are an important component of New Zealand’s littoral biodiversity across a range of intertidal habitats. A new cryptic species in this genus (Diloma durvillaea, sp. nov.) is described largely on molecular grounds from exposed coasts of the South Island of New Zealand from Lyttelton south, as well as the Auckland Islands. The shell is very similar to D. arida (Finlay, 1926), differing subtly in having stronger spiral ribs and less extensive or no yellow spotting. Phylogenetic analysis of the mitochondrial cytochrome c oxidase I (COI) gene shows these two species are sister-taxa and are more distinct from each other (genetic distance 11.5%) than are the morphologically divergent sister-species D. subrostrata (Gray, 1835) and D. aethiops (Gmelin, 1791) (8.2%), also from New Zealand. The new species is found in a novel habitat for the genus, in the holdfasts and on the blades of the bull kelp, Durvillaea antarctica (Cham.) Har. (Phaeophyta), at the low-tide mark on exposed coasts, whereas D. arida occurs higher up on the shore, as well as in more sheltered situations.
Distribution of carbon, nitrogen, phosphorus, and sulfur in the soil in a multiple habitat system in India
Authors: Prusty B. Anjan Kumar , Chandra Rachna , Azeez P. A.
Published: March 2009

We measured the background level and spatial variation of carbon (C), nitrogen (N), phosphorus (P), and sulfur (S) and associated basic soil parameters along the depth profile for 3 years, in 3 habitats (woodland, wetland, and grassland), in Keoladeo National Park (KNP), an important water fowl reserve and a world heritage site in India. The study examined soils at 5 depths (0, 0.25, 0.50, 0.75 and 1.0 m) for 3 years, i.e. from 2003 to 2005. Total organic C (TOC), total N (TN), total available P (TAP), and total available S (TAS), irrespective of the habitat type and year, were found to be highest in the litter layer, gradually declining with depth. Elemental ratios (C : N, C : P, and C : S) followed the same declining trend, whereas the N : P ratio increased down the soil profile. The high C : N and C : S ratios in the litter layer suggest the relatively low mobilisation of N and S from the decaying detritus layer. All the variables studied varied significantly among the soil layers (GLM-ANOVA, P < 0.05). Principal component analysis (PCA) showed 4 components based on examination of the scree plot. The first component accounted for 27.1% of the total variance in soil characteristics among samples, reflecting the influence of soil variables such as P, TOC, and pH. The second component accounted for 23.5% of the total variance, reflecting the influence of total dissolved solids (TDS) and TAS. The influence of C on elemental ratio (C : S) was pointed by the third component, accounted for 14.2% of the total variance. The fourth component accounted for 13.6% of the variance, indicating the influence of soil TN. Thus, the 4 PCA components that accounted for 78.4% of the total variance in the data can be qualified as N : P/soil P/C, TDS/TAS, C : S ratio, and soil TN, respectively.
A precedence effect resolves phantom sound source illusions in the parasitoid fly
Ormia ochracea
Authors: Lee Norman , Elias Damian O. , Mason Andrew C.
Published: March 2009

Localizing individual sound sources under reverberant environmental conditions can be a challenge when the original source and its acoustic reflections arrive at the ears simultaneously from different paths that convey ambiguous directional information. The acoustic parasitoid fly
Ormia ochracea
(Diptera: Tachinidae) relies on a pair of ears exquisitely sensitive to sound direction to localize the 5-kHz tone pulsatile calling song of their host crickets. In nature, flies are expected to encounter a complex sound field with multiple sources and their reflections from acoustic clutter potentially masking temporal information relevant to source recognition and localization. In field experiments,
O. ochracea
were lured onto a test arena and subjected to small random acoustic asymmetries between 2 simultaneous sources. Most flies successfully localize a single source but some localize a ‘phantom’ source that is a summed effect of both source locations. Such misdirected phonotaxis can be elicited reliably in laboratory experiments that present symmetric acoustic stimulation. By varying onset delay between 2 sources, we test whether hyperacute directional hearing in
O. ochracea
can function to exploit small time differences to determine source location. Selective localization depends on both the relative timing and location of competing sources. Flies preferred phonotaxis to a forward source. With small onset disparities within a 10-ms temporal window of attention, flies selectively localize the leading source while the lagging source has minimal influence on orientation. These results demonstrate the precedence effect as a mechanism to overcome phantom source illusions that arise from acoustic reflections or competing sources.
Fixation and fate of C and N in the cyanobacterium
Trichodesmium
using nanometer-scale secondary ion mass spectrometry
Authors: Finzi-Hart Juliette A. , Pett-Ridge Jennifer , Weber Peter K. , Popa Radu , Fallon Stewart J. , Gunderson Troy , Hutcheon Ian D. , Nealson Kenneth H. , Capone Douglas G.
Published: March 2009

The marine cyanobacterium
Trichodesmium
is ubiquitous in tropical and subtropical seas and is an important contributor to global N and C cycling. We sought to characterize metabolic uptake patterns in individual
Trichodesmium
IMS-101 cells by quantitatively imaging
13
C and
15
N uptake with high-resolution secondary ion mass spectrometry (NanoSIMS).
Trichodesmium
fix both CO
2
and N
2
concurrently during the day and are, thus, faced with a balancing act: the O
2
evolved during photosynthesis inhibits nitrogenase, the key enzyme in N
2
fixation. After performing correlated transmission electron microscopy (TEM) and NanoSIMS analysis on trichome thin-sections, we observed transient inclusion of
15
N and
13
C into discrete subcellular bodies identified as cyanophycin granules. We speculate that
Trichodesmium
uses these dynamic storage bodies to uncouple CO
2
and N
2
fixation from overall growth dynamics. We also directly quantified both CO
2
and N
2
fixation at the single cell level using NanoSIMS imaging of whole cells in multiple trichomes. Our results indicate maximal CO
2
fixation rates in the morning, compared with maximal N
2
fixation rates in the afternoon, bolstering the argument that segregation of CO
2
and N
2
fixation in
Trichodesmium
is regulated in part by temporal factors. Spatial separation of N
2
and CO
2
fixation may also have a role in metabolic segregation in
Trichodesmium
. Our approach in combining stable isotope labeling with NanoSIMS and TEM imaging can be extended to other physiologically relevant elements and processes in other important microbial systems.
FRET-based mapping of calmodulin bound to the RyR1 Ca
2+
release channel
Authors: Cornea Razvan L. , Nitu Florentin , Gruber Simon , Kohler Katherine , Satzer Michael , Thomas David D. , Fruen Bradley R.
Published: March 2009

Calmodulin (CaM) functions as a regulatory subunit of ryanodine receptor (RyR) channels, modulating channel activity in response to changing [Ca
2+
]
i
. To investigate the structural basis of CaM regulation of the RyR1 isoform, we used site-directed labeling of channel regulatory subunits and fluorescence resonance energy transfer (FRET). Donor fluorophore was targeted to the RyR1 cytoplasmic assembly by preincubating sarcoplasmic reticulum membranes with a fluorescent FK506-binding protein (FKBP), and FRET was determined following incubations in the presence of fluorescent CaMs in which acceptor fluorophore was attached within the N lobe, central linker, or C lobe. Results demonstrated strong FRET to acceptors attached within CaM's N lobe, whereas substantially weaker FRET was observed when acceptor was attached within CaM's central linker or C lobe. Surprisingly, Ca
2+
evoked little change in FRET to any of the 3 CaM domains. Donor–acceptor distances derived from our FRET measurements provide insights into CaM's location and orientation within the RyR1 3D architecture and the conformational switching that underlies CaM regulation of the channel. These results establish a powerful new approach to resolving the structure and function of RyR channels.