bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rhodium‐Catalyzed Asymmetric Nitroallylation of Arylmetallics with Cyclic Nitroallyl Acetates and Applications in Organic Synthesis
Authors: Dong Lin , Xu Yan‐Jun , Yuan Wei‐Cheng , Cui Xin , Cun Lin‐Feng , Gong Liu‐Zhu 
Published: July 2006

AbstractHighly enantioselective rhodium‐catalyzed nitroallylations of arylboronic acids and arylzinc chlorides with cyclic nitroallyl acetates are described. Catalyst screening indicated that the rhodium complex of [Rh(OH)(COD)]2 and optically pure binap is the optimal catalyst for the nitroallylation of arylboronic acids with 2‐nitrocyclohex‐2‐enyl esters, providing good yields and high enantioselectivities of up to 99 % ee. The rhodium complex prepared from Rh(acac)(C2H4)2 and (R)‐binap efficiently catalyzed the nitroallylation of arylzinc chlorides with 2‐nitrocyclohex‐2‐enyl acetate at 0 °C in high yields of up to 93 % and with high enantioselectivities of up to 96 % ee. A number of synthetically useful intermediates with high optical purity were prepared with this reaction as starting point: concise total syntheses of optically pure (+)‐β‐lycorane in 53 % overall yield and of (+)‐γ‐lycorane in 52 % overall yield were achieved by commencing with the asymmetric nitroallylation of 3,4‐methylenedioxyphenylzinc chloride with 2‐nitrocyclohex‐2‐enyl acetate. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
On‐column capture of a specific protein in capillary electrophoresis using magnetic beads
Authors: Kaneta Takashi , Inoue Junji , Koizumi Mototsugu , Imasaka Totaro 
Published: July 2006

AbstractA method for capturing specific molecules separated by CE has been explored. To demonstrate on‐column capture of migrating analyte molecules, two detection windows were fabricated on a capillary. Magnetic beads containing immobilized molecules that react with the specific molecules under study were placed between the detection windows in the capillary using magnets. Molecules in a sample solution injected into the capillary were separated and detected at the first detection window. After passing through the first detection window, the separated molecules encountered the magnetic beads, where the specific analyte was captured. As a result, the peak area for those analyte molecules decreased or disappeared completely at the second detection window. Rabbit IgG and carbonic anhydrase were employed to demonstrate on‐column capture of a specific molecule. For rabbit IgG, magnetic beads containing the immobilized antibody (anti‐rabbit IgG) were used. Rabbit IgG molecules were captured on the magnetic beads during CE migration. Furthermore, the capture of carbonic anhydrase was demonstrated by the reaction between magnetic beads (containing immobilized anti‐rabbit IgG) and anti‐carbonic anhydrase (rabbit IgG), before the beads were packed in the capillary. After packing the magnetic beads in the capillary, a mixture of two proteins was injected into the capillary. Two proteins were detected at the first detection window, while the peak corresponding to carbonic anhydrase disappeared at the second detection window. The results show that using an appropriate antibody, the present technique would be applicable to any proteins.
A sliding interface method for unsteady unstructured flow simulations
Authors: Blades Eric L. , Marcum David L. 
Published: July 2006

AbstractThe objective of this work is to develop a sliding interface method for simulations involving relative grid motion that is fast and efficient and involves no grid deformation, remeshing, or hole cutting. The method is implemented into a parallel, node‐centred finite volume, unstructured viscous flow solver. The rotational motion is accomplished by rigidly rotating the subdomain representing the moving component. At the subdomain interface boundary, the faces along the interface are extruded into the adjacent subdomain to create new volume elements forming a one‐cell overlap. These new volume elements are used to compute a flux across the subdomain interface. An interface flux is computed independently for each subdomain. The values of the solution variables and other quantities for the nodes created by the extrusion process are determined by linear interpolation. The extrusion is done so that the interpolation will maintain information as localized as possible. The grid on the interface surface is arbitrary. The boundary between the two subdomains is completely independent from one another; meaning that they do not have to connect in a one‐to‐one manner and no symmetry or pattern restrictions are placed on the grid. A variety of numerical simulations were performed on model problems and large‐scale applications to examine conservation of the interface flux. Overall solution errors were found to be comparable to that for fully connected and fully conservative simulations. Excellent agreement is obtained with theoretical results and results from other solution methodologies. Copyright © 2006 John Wiley & Sons, Ltd.
An application of the finite difference‐based lattice Boltzmann model to simulating flow‐induced noise
Authors: Kang Hokeun , Tsutahara Michihisa 
Published: July 2006

AbstractThis paper presents a novel approach to simulate aerodynamically generated sounds by modifying the finite difference‐based lattice BGK compressible fluid model for the purpose of speeding up the calculation and also stabilizing the numerical scheme. With the model, aerodynamic sounds generated by a uniform flow around a two‐dimensional circular cylinder at Re = 150 are simulated. The third‐order‐accurate up‐wind scheme is used for the spatial derivatives, and the second‐order‐accurate Runge–Kutta method is applied for the time marching. The results show that we successively capture very small acoustic pressure fluctuations, with the same frequency of the Karman vortex street, much smaller than the whole pressure fluctuation around a circular cylinder. The propagation velocity of the acoustic waves shows that the points of peak pressure are biased upstream owing to the Doppler effect in the uniform flow. For the downstream, on the other hand, it is faster. It is also apparent that the amplitude of sound pressure is proportional to r−1/2, r being the distance from the centre of the circular cylinder. Moreover, the edgetone generated by a two‐dimensional jet impinging on a wedge to predict the frequency characteristics of the discrete oscillations of a jet‐edge feedback cycle is investigated. The jet is chosen long enough to guarantee the parabolic velocity profile of the jet at the outlet, and the edge is of an angle of α = 23°. At a stand‐off distance w, the edge is inserted along the centreline of the jet, and a sinuous instability wave with real frequency is assumed to be created in the vicinity of the nozzle exit and to propagate towards the downstream. We have succeeded in capturing small pressure fluctuations resulting from periodic oscillation of jet around the edge. Copyright © 2006 John Wiley & Sons, Ltd.
Soil moisture dynamics in an eastern Amazonian tropical forest
Authors: Bruno Rogério D. , da Rocha Humberto R. , de Freitas Helber C. , Goulden Michael L. , Miller Scott D. 
Published: July 2006

AbstractWe used frequency‐domain reflectometry to make continuous, high‐resolution measurements for 22 months of the soil moisture to a depth of 10 m in an Amazonian rain forest. We then used these data to determine how soil moisture varies on diel, seasonal and multi‐year timescales, and to better understand the quantitative and mechanistic relationships between soil moisture and forest evapotranspiration. The mean annual precipitation at the site was over 1900 mm. The field capacity was approximately 0·53 m3 m−3 and was nearly uniform with soil depth. Soil moisture decreased at all levels during the dry season, with the minimum of 0·38 m3 m−3 at 3 m beneath the surface. The moisture in the upper 1 m showed a strong diel cycle with daytime depletion due to evapotranspiration. The moisture beneath 1 m declined during both day and night due to the combined effects of evapotranspiration, drainage and a nighttime upward movement of water. The depth of active water withdrawal changed markedly over the year. The upper 2 m of soil supplied ∼56% of the water used for evapotranspiration in the wet season and ∼28% of the water used in the dry season. The zone of active water withdrawal extended to a depth of at least 10 m. The day‐to‐day rates of moisture withdrawal from the upper 10 m of soil during rain‐free periods agreed well with simultaneous measurements of whole‐forest evapotranspiration made by the eddy covariance technique. The forest at the site was well adapted to the normal cycle of wet and dry seasons, and the dry season had only a small effect on the rates of land–atmosphere water vapour exchange. Copyright © 2006 John Wiley & Sons, Ltd.
Water budgets of three small catchments under montane forest in Ecuador: experimental and modelling approach
Authors: Fleischbein Katrin , Wilcke Wolfgang , Valarezo Carlos , Zech Wolfgang , Knoblich Klaus 
Published: July 2006

AbstractThe water budget of forested catchments controls the local water supply and influences the regional climate. To assess the anthropogenic impact on the water cycle, we constructed a water budget for three ∼10 ha catchments under lower montane forest on the east‐facing slope of the Andes in south Ecuador at 1900–2150 m elevation. We used field hydrological measurements and modelled surface flows with TOPMODEL, a semi‐distributed catchment model. We measured incident precipitation, throughfall, stemflow, and surface flow between May 1998 and April 2002 in hourly to weekly resolution, and determined all variables needed to parameterise TOPMODEL. On average, of the four monitored years and three catchments, incident precipitation was 2504 ± SD 123 mm, throughfall 1473 ± 197 mm, and stemflow 25 ± 2 mm yr−1. Fog water input was negligible. Mean annual interception loss in the forest was 1006 ± 270 mm, and mean annual surface flow, calculated with TOPMODEL in an hourly resolution was 1039 ± 48 mm. The resulting mean annual evapotranspiration was 1466 ± 161 mm of which 32% ( =471 ± 162 mm) was transpiration if evaporation from the soil was neglected. Our study catchments show a high evapotranspiration attributable to the strong solar insolation near the equator, the small impact of fog, the generally low intensity of incident precipitation and additional wind‐driven advective energy input. Copyright © 2006 John Wiley & Sons, Ltd.
Water storage and runoff processes in plinthic soils under forest and pasture in eastern Amazonia
Authors: de Moraes Jorge M. , Schuler Azeneth E. , Dunne Thomas , Figueiredo Ricardo de O. , Victoria Reynaldo L. 
Published: July 2006

AbstractExtensive areas of the Amazon River basin are underlain by soils with shallow impeding horizons. To evaluate how the distinctive hydraulic properties of soil with a plinthic horizon under forest and pasture affect water storage and runoff process, two first‐order catchments drained by ephemeral streams were instrumental in eastern Amazonia. Field measurements showed the presence of a strong vertical gradient of saturated hydraulic conductivity, which declines to extremely low values (median <1 mm h−1) at the plinthite layer, limiting both vertical and lateral flow, and keeping the soil water content close to saturation throughout most of the wet season. This scenario led to the frequent occurrence of saturation overland flow (SOF) under both land covers and very small amounts of shallow sub‐surface flow (SSF). The annual flow in the exit channels was 3·2% of throughfall (2·7% of annual rainfall) under forest and 17% of annual rainfall for pasture, while the frequency of days with overland flow (OVF) was about 60% of the days for both catchments during the wet season. In the forest, all OVF originated from saturated areas, while in the pasture, infiltration‐excess OVF accounted for 40% of the runoff and SOF accounted for 55% of runoff. The higher flow generation in the pasture could be explained by the higher water storage compared to the forest, promoting more frequent SOF, and additionally by the lower hydraulic conductivity near the surface favouring the occurrence of Horton overland flow (HOF). Copyright © 2006 John Wiley & Sons, Ltd.
Transport of water, solutes and nutrients from a pasture hillslope, southwestern Brazilian Amazon
Authors: Biggs Trent Wade , Dunne Thomas , Muraoka Takashi 
Published: July 2006

AbstractA conceptual model of water and solute transport pathways was developed and applied to a pasture hillslope in the southwestern Brazilian Amazon basin using select field measurements. Infiltration‐excess or Horton overland flow (HOF), saturation overland flow (SOF), and groundwater in both the near‐stream zone and upslope were sampled on a hillslope draining a 3·9 hectare pasture for a total of ten storms during the first half of the rainy season (October–November) in 2002. A Soil Conservation Service SCS curve number model of HOF and an annual water balance of both upslope and near‐stream zones were used to calculate the contribution of each flowpath to solute export. HOF occurred in rainstorms greater than 5 mm and accounted for ∼8% of annual rainfall. Flow generated in the near‐stream zone was ∼8% of annual rainfall. Sub‐surface flow from upslope groundwater dominated annual runoff (∼19–30% of annual rainfall). Solutes fell into three categories according to flowpath. HOF from upslope positions dominated the export of total phosphorus (TP) and total dissolved phosphorus (TDP, 51–72% of total annual export). The near‐stream zones controlled the export of K (58–65%), total dissolved nitrogen (TDN, 76–80%), and total nitrogen (TN, ∼75%) owing to relatively high solute concentrations and the large volume of water that flowed through the near‐stream zone. Na and Si export was via groundwater from upslope (50–67% of annual export). The flux calculations were based on a small number of storms and are preliminary estimates designed to identify broad patterns in solute export via different hydrologic pathways. Additional processes, especially N removal at the groundwater‐stream interface and in the stream channel, may affect actual export rates at the watershed scale. Whereas HOF production is negligible in Amazon forests, it represents a significant pathway for additional loss of elements, especially phosphorus, from mature pasture systems. The evidence presented here shows that biogeochemical perturbations and enhanced solute fluxes continue for decades following deforestation for pasture. Copyright © 2006 John Wiley & Sons, Ltd.
Deforestation alters the hydraulic and biogeochemical characteristics of small lowland Amazonian streams
Authors: Neill Christopher , Deegan Linda A. , Thomas Suzanne M. , Haupert Christie L. , Krusche Alex V. , Ballester Victoria M. , Victoria Reynaldo L. 
Published: July 2006

AbstractWe investigated how clearing of the tropical rainforest for cattle pasture along small, terra firme lowland streams in the Brazilian Amazon influenced stream hydraulic characteristics, solute concentrations and uptake of dissolved inorganic nitrogen and phosphorus. Measurements of stream channel structure, hydraulic properties and nutrient uptake were obtained from short‐term conservative and non‐conservative solute injections and an in‐stream transport model in two watersheds with pairs of similar‐sized forest and pasture streams in Rondônia. The pasture stream channels were deeper and had a lower cover of sandy bottom habitat and a higher cover of aquatic grass habitat than the forest streams. The pasture streams had larger transient storage zones, higher ratios of transient to channel storage and a shorter hydraulic uptake length than the forest streams. The pasture streams had lower concentrations of dissolved oxygen and NO3− and higher concentrations of dissolved Fe2+. Forest streams exhibited no NO3− uptake, but one pasture stream took up NO3− while the other did not. Uptake of NH4+ was low and variable among streams. Uptake velocities and rates of PO43− were greater in pasture streams compared to those in forest streams. In all streams, uptake lengths for NO3−, NH4+ and PO43− were long and indicated generally lower rates of uptake than in most comparably sized temperate forest streams. Uptake lengths or velocities were not correlated with stream transient storage, suggesting that other factors, such as hypoxia in pasture streams, controlled nutrient uptake. The structural differences are typical for the region, suggesting that deforestation may be altering stream hydrology and biogeochemistry over many thousands of kilometres of primary and secondary stream channels in the Amazon Basin. A better understanding of the extent and distribution of altered hydraulic and biogeochemical function in small streams is required to assess the importance of these changes for larger river networks in the Amazon basin. Copyright © 2006 John Wiley & Sons, Ltd.
Dissolved rainfall inputs and streamwater outputs in an undisturbed watershed on highly weathered soils in the Brazilian cerrado
Authors: Markewitz Daniel , Resende Julio C. F. , Parron Lucilia , Bustamante Mercedes , Klink Carlos A. , Figueiredo Ricardo de O. , Davidson Eric A. 
Published: July 2006

AbstractThe cerrados of Brazil cover 2 million km2. Despite the extent of these seasonally dry ecosystems, little watershed research has been focused in this region, particularly relative to the watersheds of the Amazon Basin. The cerrado shares pedogenic characteristics with the Amazon Basin in draining portions of the Brazilian shield and in possessing Oxisols over much of the landscape. The objective of this research was to quantify the stream water geochemical relationships of an undisturbed 1200 ha cerrado watershed for comparison to river geochemistry in the Amazon. Furthermore, this undisturbed watershed was used to evaluate stream discharge versus dissolved ion concentration relationships. This research was conducted in the Córrego Roncador watershed of the Reserva Ecológica do Roncador (RECOR) of the Instituto Brasileiro Geografia e Estatística (IBGE) near Brasilia, Brazil. Bulk precipitation and stream water chemistry were analysed between May 1998 and May 2000. The upland soils of this watershed are nutrient poor possessing total stocks of exchangeable elements in the upper 1 m of 81 ± 13, 77 ± 4, 25 ± 3, and 1 ± 1 kg ha−1 of K, Ca, Mg, and P, respectively. Bulk precipitation inputs of dissolved nutrients for this watershed are low and consistent with previous estimates. The nutrient‐poor soils of this watershed, however, increase the relative importance of precipitation for nutrient replenishment to vegetation during episodes of ecosystem disturbance. Stream water dissolved loads were extremely dilute with conductivities ranging from 4 to 10 µS cm−1 during periods of high‐ and low‐flow, respectively. Despite the low concentrations in this stream, geochemical relationships were similar to other Amazonian streams draining shield geologies. Discharge‐concentration relationships for Ca and Mg in these highly weathered soils developed from igneous rocks of the Brazilian shield demonstrated a significant negative relationship indicating a continued predominance of groundwater baseflow contributions these cationic elements. Copyright © 2006 John Wiley & Sons, Ltd.
Integrated approach to improving the value potential of biopharmaceutical R&D portfolios while mitigating risk
Authors: Rajapakse Anuradha , Titchener‐Hooker Nigel J , Farid Suzanne S 
Published: July 2006

AbstractEffective prioritisation of R&D portfolios under resource constraints is critical for biopharmaceutical companies to gain competitive advantage. This paper presents an application of a prototype software tool to assess the reward and risk associated with different drug portfolios in development. The tool adopts a hierarchical framework to incorporate the interactions between drug development activities, the available resources and databases. The valuation approach highlights the cash flow implications of diverse portfolios under uncertainty and uses efficient frontier analysis to prioritise portfolios for given constraints. A case study is presented to illustrate the application of this method where Monte Carlo simulations are used to capture the inherent uncertainties in drug development. The example addresses the portfolio management question of which antibody drug candidates to select for clinical development given finite levels of resources. The analysis highlighted the impact of different drug combinations on the expected portfolio profitability and risk. The simulation studies were used to generate efficient frontiers so as to identify the optimal portfolios at different levels of risk and budgetary constraint. This valuation method helps decision‐makers to identify clearly where a company portfolio is positioned with regard to the risk‐return characteristics of alternative product portfolios and hence facilitates investment decisions. Copyright © 2006 Society of Chemical Industry
Faith matters: faith‐based organisations, civil society and international development
Authors: Clarke Gerard 
Published: July 2006

AbstractGrowing interest in faith‐based organisations (FBOs) and development risks compounding conceptual and programmatic biases in recent donor discourse on civil society and development. This article develops this argument in two main respects. First, it argues, donors have traditionally focused on supporting organisations associated with the mainstream Christian Churches and current patterns of engagement risk compounding this trend. Second, different types of faith‐based organisation play an active role in the lives of the poor and in the political contests that affect them. Improving the conceptual and programmatic rationale for donor engagement with FBOs depends in significant part on developing an appreciation of these organisational types and the resultant challenges. Copyright © 2006 John Wiley & Sons, Ltd.
New tools to connect people and places: the impact of ICTs on learning among resource poor farmers in Bolivia
Authors: Nielsen Louise , Heffernan Claire 
Published: July 2006

AbstractInformation Communication Technologies (ICTs) have the ability to rapidly connect the poor to both wider communities and larger knowledge sets. However, while the use of ICTs in development has increased dramatically in recent years, there is a dearth of evidence regarding the impact and uptake of programmes. Therefore, the following article describes the development of El Promotor, a multi‐media, interactive programme for poor farmers on the Bolivian Altiplano. The study further examined the relationship between new and existing knowledge regarding animal health and production among 85 farmers in 13 communities, who utilised the programme. The authors found that the uptake of new knowledge was highly dependent upon the specific topic involved i.e. disease causation, symptoms, treatment and prevention. Not surprisingly, the level of challenge to existing beliefs also impacted learning levels. Nonetheless, by utilising visual referents, which supported customary knowledge, improvements in farmer understanding of disease causation, diagnosis, treatment were noted after use of the programme. Copyright © 2006 John Wiley & Sons, Ltd.