bluuebunny/crossref_metadata_2025 huggingface dataset:
Low-frequency noises as a tool for UV detector characterisation
Authors: Ćwirko R. , Bielecki Z. , Ćwirko J. , Dobrzański L.
Published: July 2006

Ultraviolet (UV) semiconductor detectors are mainly made of materials with wide energy gap, i.e., of AlGaN, GaP, SiC, and diamond. The article describes methodology of measurements of characteristics of low-frequency noises of UV detectors and presents the developed measuring system. Basing on analysis of noise characteristics of detectors, an optimal working point of detector can be determined. The results of measurements of noise characteristics of UV detectors made of AlGaN are shown. The measurements have been carried out in wide range of temperatures for several values of a detector supply voltage.
Succeeding in the City: Challenges and Best Practices on Urban Commuter Campuses
Authors: Clark Marcia Roe
Published: July 2006

Students who make the daily commute to urban campuses face academic and nonacademic issues not typically experienced by their suburban or rural counterparts. A veteran of multiple types of campus environments offers insight into the lives of these students and suggests strategies for helping college urbanites thrive.
Memory fragments as components of autobiographical knowledge
Authors: Bruce Darryl , Phillips‐Grant Kimberly , Wilcox‐O'Hearn L. Amber , Robinson John A. , Francis Lori
Published: July 2006

Adults described and dated two kinds of personal remembrances: a fragment—a memory moment that is largely bereft of context—and an episodic, personal event memory—a narrative that consists of a number of related events. In Experiment 1 subjects reported memories from when they were 0–8 years of age and in Experiment 2, from when they were 0–16 years of age. Fragments were judged to be older than event memories, especially in Experiment 2 where the estimated ages of most fragments were from 0 to 8 years and of most episodic memories, from 8 to 16 years. Ratings of various features of the two kinds of memories also differed. We conclude that isolated memory moments possess validity and that although they are most likely to arise when the autobiographical memory system is not fully developed, they can also originate during a time when it is. Copyright © 2006 John Wiley & Sons, Ltd.
Memory demands on facial composite identification
Authors: Oswald Karl M. , Coleman Marjorie L.
Published: July 2006

Face composites created with FACES 3.0 composite software were used to identify target photographs under varying conditions of memory load. Composites created while viewing a mugshot were presented concurrently with a five‐photograph lineup of actual criminal suspects, immediately preceding the lineup, or with a filled delay between composite and lineup. Compared to a baseline using the mock witness technique, results demonstrated above‐chance identification of target photographs from their composites in all four experiments. Identification was highest with concurrent composite‐lineup presentation and lower under immediate, 30‐second‐delayed, and 4‐minute‐delayed conditions, with no significant identification differences across the three memory conditions. Confidence ratings in target selection only weakly predicted identification accuracy at best. These findings extend the limited research on computerized facial composite systems while addressing composite software use, efficacy, guidelines and limitations. Copyright © 2006 John Wiley & Sons, Ltd.
The examination assessment of technical competence in vascular surgery
Authors: Pandey V A , Wolfe J H N , Liapis C D , Bergqvist D
Published: July 2006

Background

The European Board of Surgery Qualification in Vascular Surgery is a pan-European examination for vascular surgeons who have attained a national certificate of completion of specialist training. A 2-year study was conducted before the introduction of a technical skills assessment in the examination.

Methods

The study included 30 surgeons: 22 candidates and eight examiners. They were tested on dissection (on a synthetic saphenofemoral junction model), anastomosis (on to anterior tibial artery of a synthetic leg model) and dexterity (a knot-tying simulator with electromagnetic motion analysis). Validated rating scales were used by two independent examiners. Composite knot-tying scores were calculated for the computerized station. The stations were weighted 35, 45 and 20 per cent, respectively.

Results

Examiners performed better than candidates in the dissection (P < 0·001), anastomosis (P = 0·002) and dexterity (P = 0·005) stations. Participants performed consistently in the examination (dissection versus anastomosis: r = 0·79, P < 0·001; dexterity versus total operative score: r = −0·73, P < 0·001). Interobserver reliability was high (α = 0·91). No correlation was seen between a candidate's technical skill and oral examination performance or logbook-accredited scores.

Conclusion

Current surgical examinations do not address technical competence. This model appears to be a valid assessment of technical skills in an examination setting. The standards are set at a level appropriate for a specialist vascular surgeon.
Short-term results of a randomized clinical trial comparing Lichtenstein open repair with totally extraperitoneal laparoscopic inguinal hernia repair
Authors: Eklund A , Rudberg C , Smedberg S , Enander L K , Leijonmarck C E , Österberg J , Montgomery A
Published: July 2006

Background

Laparoscopic herniorrhaphy has emerged as a recognized operative method for inguinal hernia repair. This study compared the short-term results of two tension-free methods of repair: totally extraperitoneal (TEP) laparoscopic patch repair and the open Lichtenstein mesh technique.

Methods

A total of 1513 men from 11 hospitals who presented with a primary unilateral inguinal hernia were randomized to one of the two methods. Operating time, short-term complications, reoperations, postoperative pain, consumption of analgesics, sick leave and time to resumption of normal physical activities were recorded.

Results

Some 1371 of the 1513 men underwent surgery, 665 in the TEP group and 706 in the Lichtenstein group. The median duration of operation was 55 min for both procedures and 91·0 per cent of the patients in both groups were discharged on the day of operation. Patients in the TEP group experienced less postoperative pain (P < 0·001), consumed fewer analgesics (P < 0·001), had a shorter period of sick leave (7 versus 12 days; P < 0·001) and a shorter time to resumption of normal physical activity (20 versus 31 days; P < 0·001).

Conclusion

The TEP technique took no longer to perform, and was associated with less postoperative pain, a shorter period of sick leave and a faster recovery, compared with open Lichtenstein hernia repair.
Real‐time locomotion control by sensing gloves
Authors: Komura Taku , Lam Wai‐Chun
Published: July 2006

Sensing gloves are often used as an input device for virtual 3D games. We propose a new method to control characters such as humans or animals in real‐time by using sensing gloves. Based on existing motion data of the body, a new method to map the hand motion of the user to the locomotion of 3D characters in real‐time is proposed. The method was applied to control locomotion of characters such as humans or dogs. Various motions such as trotting, running, hopping, and turning could be produced. As the computational cost needed for our method is low, the response of the system is short enough to satisfy the real‐time requirements that are essential to be used for games. Using our method, users can directly control their characters intuitively and precisely than previous controlling devices such as mouse, keyboards or joysticks. Copyright © 2006 John Wiley & Sons, Ltd.
Procedural rhythmic character animation: an interactive Chinese lion dance
Authors: Li Tsai‐Yen , Chen Je‐Ren
Published: July 2006

The creation of a stylistic animation through the use of high‐level controls has always been a design goal for computer animation software. In this paper, we propose a procedural animation system, called rhythmic character animation playacting (RhyCAP), which allows a designer to interactively direct animated characters by adjusting rhythmic parameters such as tempo, exaggeration, and timing. The motions thus generated reflect the intention of the director and also adapt to environmental obstacle constraints. We use a sequence of martial‐art steps in the performance of a Chinese lion dance to illustrate the effectiveness of the system. The animation is generated by composition of common motion elements, concisely represented in an action graph. We have implemented an animation control program that allows Chinese lion dance to be choreographed interactively. This authoring tool also serves as a useful means for preserving this part of world cultural heritage. Copyright © 2006 John Wiley & Sons, Ltd.
Chemoprevention: Drug pricing and mortality
Authors: Melnikow Joy , Kuenneth Christina , Helms L. Jay , Barnato Amber , Kuppermann Miriam , Birch Stephen , Nuovo James
Published: July 2006

BACKGROUND.

Tamoxifen is a prototypic cancer chemopreventive agent, yet clinical trials have not evaluated its effect on mortality or the impact of drug pricing on its cost‐effectiveness.

METHODS.

A state‐transition Markov model for a hypothetical cohort of women age 50 years was used to evaluate the effects of tamoxifen on mortality and tamoxifen price on cost‐effectiveness. Incidence and mortality rates for breast and endometrial cancers were derived from Surveillance, Epidemiology and End Results statistics, and noncancer outcomes were obtained from published studies. Relative risks of outcomes were derived from the National Surgical Adjuvant Breast and Bowel Project P‐1 trial. Costs were based on Medicare reimbursements.

RESULTS.

Projected overall mortality for women at 1.67% 5‐year breast cancer risk showed little difference with or without tamoxifen, resulting in a cost‐effectiveness ratio of $1,335,690 per life‐year saved as a result of tamoxifen use. Adjusting for the differential impact of estrogen receptor‐negative cancers, tamoxifen increased mortality for women with a uterus until the 5‐year breast cancer risk reached ≥2.1%. Assigning the Canadian price for tamoxifen dramatically reduced the incremental cost (to $123,780 per life‐year saved). At that price, the use of tamoxifen was less costly and more effective for women with 5‐year breast cancer risks >4%.

CONCLUSIONS.

Tamoxifen may increase mortality in women at the lower end of the “high‐risk” range for breast cancer. If prices in the U.S. approximated Canadian prices, then tamoxifen use for breast cancer risk reduction in women with a 5‐year risk >3% could be a reasonable strategy to reduce the incidence of breast cancer. Because they are used by many unaffected individuals, the price of chemopreventive agents has a major influence on their cost‐effectiveness. Cancer 2006. © 2006 American Cancer Society.
Characterization of a mouse strain expressing Cre recombinase from the 3′ untranslated region of the dopamine transporter locus
Authors: Bäckman Cristina M. , Malik Nasir , Zhang YaJun , Shan Lufei , Grinberg Alex , Hoffer Barry J. , Westphal Heiner , Tomac Andreas C.
Published: July 2006

Dopamine (DA) neurotransmission has been implicated in several neurological and psychiatric disorders. The dopamine transporter (DAT) is highly expressed in dopaminergic neurons of the ventral mesencephalon and regulates neurotransmission by transporting DA back into the presynaptic terminals. To mediate restricted DNA recombination events into DA neurons using the Cre/loxP technology, we have generated a knockin mouse expressing Cre recombinase under the transcriptional control of the endogenous DAT promoter. To minimize interference with DAT function by preservation of both DAT alleles, Cre recombinase expression was driven from the 3′ untranslated region (3′UTR) of the endogenous DAT gene by means of an internal ribosomal entry sequence. Crossing this murine line with a LacZ reporter showed colocalization of DAT immunocytochemistry and β‐galactosidase staining in all regions analyzed. This knockin mouse can be used for generating tissue specific knockouts in mice carrying genes flanked by loxP sites, and will facilitate the analysis of gene function in dopaminergic neurons. genesis 44:383–390, 2006. Published 2006 Wiley‐Liss, Inc.
Preparation of Hydroxylamine and O‐Methylhydroxylamine Complexes of Manganese and Rhenium
Authors: Albertin Gabriele , Antoniutti Stefano , Bravo Jorge , Castro Jesús , García‐Fontán Soledad , Marín Ma Carmen , Noè Marco
Published: July 2006

Hydroxylamine and O‐methylhydroxylamine complexes [M(NH2OH)(CO)nP5–n]BPh4 and [M(NH2OCH3)(CO)nP5–n]BPh4 [M = Mn, Re; n = 1, 2, 3; P = P(OEt)3, PPh(OEt)2, PPh2OEt] were prepared by allowing hydrides MH(CO)nP5–n to react first with triflic acid and then with an excess of hydroxylamine. Bidentate phosphane and phosphite can also be used to prepare both NH2OH and NH2OCH3 complexes of manganese and rhenium of the [M(NH2OR)(CO)2(P–P)‐{P(OEt)3}]BPh4 and [M(NH2OR)(CO)3(P–P)]BPh4 [R = H, CH3; P–P = Ph2POCH2CH2OPPh2, Ph2PO(CH2)3OPPh2, Ph2PN(CH3)CH2CH2N(CH3)PPh2] types with the use of MH(CO)2(P–P){P(OEt)3} and MH(CO)3(P–P) as precursors. The complexes were characterized spectroscopically and by theX‐ray crystal‐structure determination of [Re(NH2OCH3)(CO)2{PPh(OEt)2}3]BPh4 and [Re(NH2OCH3)(CO)3{Ph2PO(CH2)3OPPh2}]BPh4. Oxidation of the hydroxylamine complexes with Pb(OAc)4 was studied at –40 °C and led to an unstable compound tentatively characterized as a nitroxyl [M]–N(H)=O derivative.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
The Two‐Step Spin Conversion in a Supramolecular Triple Helicate Dinuclear Iron(II) Complex Studied by Mössbauer Spectroscopy
Authors: Garcia Yann , Grunert C. Matthias , Reiman Sergey , van Campenhoudt Olivier , Gütlich Philipp
Published: July 2006

The triple helicate dinuclear iron(II) complex, [Fe2(L)3](ClO4)4·2H2O (1), previously reported by Tuna et al. (Chem. Eur. J. 2004, 10, 5737), was prepared and characterised by detailed SQUID and 57Fe Mössbauer measurements. Compound 1 exhibits a thermochromic two‐step spin conversion at TSC(1) ca. 240 K and TSC(2) ca. 120 K, but does not switch its spin state further below 20 K as proven by Mössbauer spectroscopy. The sharp variation of the susceptibility below 20 K is due to zero‐field splitting of the remaining iron(II) high‐spin species. Applied field 57Fe Mössbauer spectroscopy experiments at 4.2 K indicate that the gradual thermal spin conversion from [HS–HS] pairs to [LS–LS] pairs is complete for one half of the FeII active sites. The presence of a step tracked in the spin‐conversion curve and through the variation of the Mössbauer parameters of an uncoupled iron(II) site call for the occurrence of an [LS–HS] intermediate spin state in the plateau region.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
SN2 Displacement by Bromide Ions in Dichloromethane – The Role of Reverse Micelles
Authors: Brinchi Lucia , Germani Raimondo , Savelli Gianfranco , Spreti Nicoletta
Published: July 2006

Reverse micellar systems are of interest as reaction media because they are powerful models for biological compartmentalization, enzymatic catalysis and separation of biomolecules. Solutions of ionic surfactants in apolar solvents may contain reverse micelles, but they may also contain ion pairs, or small clusters, with waters of hydration. We studied the bimolecular reaction in CH2Cl2 solutions of cationic tetraalkylammonium bromide salts (onium salts), such as cetyltrimethylammonium bromide (CTABr), cetyltripropylammonium bromide (CTPABr) and tetra‐n‐butylammonium bromide (TBABr). Methylnaphthalene‐2‐sulfonate (β‐MeONs), its 6‐sulfonate derivative (β‐MeONsS–) as the 2,6‐lutidinium salt and methyl‐5‐N,N,N,trimethylammonium naphthalene‐1‐sulfonate (α‐MeONsNT+) as the trifluoromethanesulfonate salt react with Br– in CH2Cl2. First‐order rate constants, kobs, increase linearly and similarly for the three substrates with increasing concentrations of the onium salts. Reactions are faster with TBABr than they are with CTPABr and CTABr, and the reactivity of the three substrates is in the order: α‐MeONsNT+ >> β‐MeONsS– > β‐MeONs. The reactions are inhibited by the addition of H2O, but CTABr tolerates H2O in large excess. At [H2O]/[CTABr] = w0 ≈ 6, “water‐pool” reverse micelles form, and kobs for all three substrates is then independent of w0. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
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

Highly 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

A 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

The 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

This 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

We 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

The 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

Extensive 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

A 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

We 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

The 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

Effective 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

Growing 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

Information 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.
Water‐elutability of nucleic acids from metal‐chelate affinity adsorbents: enhancement by control of surface charge density
Authors: Fu Joseph Y. , Potty Ajish S. R. , Fox George E. , Willson Richard C.
Published: July 2006

Immobilized metal affinity chromatography (IMAC) is widely used for purification of proteins, especially “hexahistidine‐tagged” recombinant proteins. We previously demonstrated the application of IMAC to selective capture of nucleic acids, including RNA, selectively‐denatured genomic DNA, and PCR primers through interactions with purine bases exposed in single‐stranded regions. We also found that the binding affinity of nucleic acids for IMAC adsorbents can be increased several‐fold by addition of 20 volume% of neutral additives such as ethanol or DMSO. In the present work, it is demonstrated that bound nucleic acids can be effectively eluted with water instead of the usual imidazole‐containing competitive eluants, when the surface density of negative charges is enhanced by operation at alkaline pH, or by deliberate metal‐underloading of the anionic chelating ligands. With enhanced negative surface charge density, nucleic acid adsorption can be made strongly dependent on the presence of adsorption‐promoting additives and/or repulsion‐shielding salts, and removal of these induces elution. Complete water‐elutability is demonstrated for baker's yeast RNA bound to 10% Cu(II)‐ underloaded IDA Chelating Sepharose in a binding buffer of 20 mM HEPES, 240 mM NaCl, pH 7. Water elutability will significantly enhance the utility of IMAC in nucleic acid separations. Copyright © 2006 John Wiley & Sons, Ltd.
Interaction of sugars, polysaccharides and cells with boronate‐containing copolymers: from solution to polymer brushes
Authors: Ivanov Alexander E. , Galaev Igor Yu. , Mattiasson Bo
Published: July 2006

Interaction of mono‐ and disaccharides, polysaccharide particles and yeast cells with boronate‐containing copolymers (BCC) of N‐acryloyl‐m‐aminophenylboronic acid (NAAPBA) with N,N‐dimethylacrylamide (DMAA) or N‐isopropylacrylamide (NIPAM) was studied. The binding of saccharides to BCC of NIPAM resulted in a shift of its phase transition temperature (ΔTP), which provided a quantitative measure for the complex formation. Among the sugars typical of non‐reducing ends of glycoproteins the ΔTP decreased in the order: N‐acetylneuraminic acid > xylose ≈ galactose > mannose ≈ fucose ≫ N‐acetylglucosamine. Strong specific adsorption of the BCC on the cross‐linked agarose gel Sepharose CL‐6B (15–30 mg/ml gel at pH 9.2) was registered. The copolymers adsorption was due to boronate‐sugar interactions and decreased with pH. Multivalent interaction of the BCC with the agarose gel has been proven by liquid column chromatography exhibiting a weak reversible adsorption of NAAPBA and almost irreversible adsorption of DMAA‐NAAPBA copolymer from 0.1 M sodium phosphate buffer, pH 7.9. The two studied BCCs could be completely desorbed from the gel by 0.1 M fructose in aqueous buffered media with pH from 7.5 to 9.2. In turn, the agarose particles and yeast cells were found to adhere to siliceous supports end‐grafted with boronate‐BCC of N,N‐dimethylacrylamide at pH ≥7.5, due to the actions. Quantitative detachment of adhered particles or cells could be attained by addition of 20 mM or 100 mM fructose, respectively, in the pH range from 7.5 to 9.2. Affinity adhesion of micron‐size carbohydrate particles to boronate‐containing polymer brushes fixed on solid supports was considered as a model system suggesting a new approach to isolation and separation of living cells. Copyright © 2006 John Wiley & Sons, Ltd.
Cover Picture: Macromol. Chem. Phys. 14/2006
Authors: Fornof Ann R. , Glass Thomas E. , Long Timothy E.
Published: July 2006

Cover: This cover illustrates the chemical structure of a highly branched polyurethane obtained using oligomeric poly(ethylene oxide) units in combination with an A2 plus B3 synthetic methodology. Size exclusion chromatography confirms the gradual increase in molar mass without the formation of crosslinked product. The molar mass between branch points permits the formation of more ductile films with facile melt processibility, and maintained ionic conductivity upon salt doping. Further details can be found in the Full Paper by A. R. Fornof, T. E. Glass, and T. E. Long* on page 1197.
On local non‐compactness in recursive mathematics
Authors: Simonsen Jakob G.
Published: July 2006

A metric space is said to be locally non‐compact if every neighborhood contains a sequence that is eventually bounded away from every element of the space, hence contains no accumulation point. We show within recursive mathematics that a nonvoid complete metric space is locally non‐compact iff it is without isolated points.

The result has an interesting consequence in computable analysis: If a complete metric space has a computable witness that it is without isolated points, then every neighborhood contains a computable sequence that is eventually computably bounded away from every computable element of the space. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The model theory of m‐ordered differential fields
Authors: Rivière Cédric
Published: July 2006

In his Ph.D. thesis [7], L. van den Dries studied the model theory of fields (more precisely domains) with finitely many orderings and valuations where all open sets according to the topology defined by an order or a valuation is globally dense according with all other orderings and valuations. Van den Dries proved that the theory of these fields is companionable and that the theory of the companion is decidable (see also [8]).

In this paper we study the case where the fields are expanded with finitely many orderings and an independent derivation. We show that the theory of these fields still admits a model companion in the language L$^D_{<, m}$ = {+, –, ·, D, <1, …, <m, 1, 0}. We denote this model companion by CODFm and give a geometric axiomatization of this theory which uses basic notions of algebraic geometry and some generalized open subsets which appear naturally in this context. This axiomatization allows to recover (just by putting m = 1) the one given in [4] for the theory CODF of closed ordered differential fields. Most of the technics we use here are already present in [2] and [4].

Finally, we prove that it is possible to describe the completions of CODFm and to obtain quantifier elimination in a slightly enriched (infinite) language. This generalizes van den Dries' results in the “derivation free” case. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Definable subgroups of measure algebras
Authors: Berenstein Alexander
Published: July 2006

We show that type‐definable subgroups of measure algebras are definable. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of Alkyl‐Functionalized Hyperbranched Polymers and Their Use as Additives in Cationic Photopolymerization of Epoxy Resins
Authors: Di Gianni Anna , Sangermano Marco , Malucelli Giulio , Voit Brigitte
Published: July 2006

Summary: An alkyl‐functionalized hyperbranched polymer, HBP(OH)–C16, was synthesized by partial modification with fatty acid of an aromatic‐aliphatic OH‐terminated hyperbranched polyester HBPOH. This product was used as additive in the cationic photopolymerization of an epoxy resin. The alkyl‐modified polyester takes part in the photopolymerization process thanks to the residual OH groups by means of chain‐transfer reactions. An increase of the epoxy conversion is observed by increasing the amount of the HBP additive in the photocurable resin with a modification of the bulk properties of the final ultraviolet‐cured films. The presence of HBP(OH)–C16 induces an increase in glass transition temperature, thermal stability, and solvent resistance. Moreover the surface properties of the films are modified achieving highly hydrophobic surfaces in the presence of even very low amounts of HBP(OH)–C16.

Structure of HBP–C16.

magnified image

Structure of HBP–C16.