bluuebunny/crossref_metadata_2025 huggingface dataset:
Sonographic umbilical cord morphometry and coiling patterns in twin–twin transfusion syndrome
Authors: Cromi Antonella , Ghezzi Fabio , Dürig Peter , Di Naro Edoardo , Raio Luigi
Published: September 2005

Objective

Monochorionic twins with twin–twin transfusion syndrome (TTTS) provide an ideal model in which to evaluate the influence of differing hemodynamic stress on umbilical cord (UC) morphology. The purpose of this study was to investigate the UC morphometry and UC coiling pattern at ultrasound in monochorionic twin pregnancies with TTTS.

Methods

A targeted sonographic evaluation of the UC was performed in 21 consecutive twin pregnancies with untreated TTTS. The cross‐sectional area of the UC and of its vessels was measured. The Wharton's jelly area was computed by subtracting the vessels area from the area of the UC. The umbilical coiling index (UCI) was calculated as the reciprocal of the sonographic length of one complete vascular coil. The UCs were classified as uncoiled, normally coiled, hypocoiled, hypercoiled and atypically coiled (UCI not valuable).

Results

The UCs of recipient twins were invariably larger than those of donors, and this difference was mainly attributable to both a larger amount of Wharton's jelly and a larger umbilical vein diameter. The proportion of lean UCs was higher in the donor than in the recipient fetuses (18/21 vs 1/21, p < 0.0001), while large UCs were significantly more frequent in the recipient than in the donor twins (13/21 vs 1/21, p = 0.0002). In all twin pairs, a discordant umbilical coiling pattern was observed between the donor and the recipient twin. The prevalence of uncoiled and hypocoiled cords was higher in the donor group, while hypercoiling and atypical coiling were more frequently detected in the recipient group.

Conclusions

A discordant UC morphometry represents an additional phenotypic feature of twins with TTTS. The discordant intertwin coiling pattern in TTTS argues against an exclusively genetic origin of UC twists, and further supports a key role of hemodynamic forces in coiling development. Copyright © 2005 John Wiley & Sons, Ltd.
Diagnosis of conjoined twins before 16 weeks' gestation: the 4‐year experience of one medical center
Authors: Maymon Ron , Mendelovic Sonia , Schachter Morey , Ron‐El Raphael , Weinraub Zwi , Herman Arie
Published: September 2005

Background

Descriptions of the rarely occurring condition of conjoined twins are sparse.

Methods

We report a case series of four conjoined twin pregnancies diagnosed up to 16 weeks of gestation. One was in a quadruplet in vitro fertilization intracytoplasmic sperm injection (IVF‐ICSI) pregnancy of cryopreserved embryos and the others were spontaneous conceptions. Three were thoracopagus and had increased nuchal translucency (NT) or big nuchal cysts and one was omphalopagus.

Results

All the three affected twin pregnancies were terminated by cervical dilatation and uterine evacuation. In another case, selective fetal reduction, shortly followed by embryo reduction to singleton was performed. Histological analysis of one case revealed dissimilar gender. No further cytogenetic or molecular studies were conducted by parental request. The pathophysiology of increased NT, subcutaneous edema or nuchal cysts in thoracopagus conjoined twins, the possible embryonic events that may lead to dizygotic conjoined twins and the clinical management of conjoined twins in sets of multiple gestation are discussed.

Conclusions

The current case series illustrates that there are many problems related to this rare, but intriguing, accident of nature that still need to be overcome. Copyright © 2005 John Wiley & Sons, Ltd.
An algorithm to derive a numerical daily dose from unstructured text dosage instructions
Authors: Shah Anoop D. , Martinez Carlos
Published: September 2005

Purpose

The General Practice Research Database (GPRD) is a database of longitudinal patient records from general practices in the United Kingdom. It is an important data source for pharmacoepidemiology studies, but until now it has been tedious to calculate the daily dose and duration of exposure to drugs prescribed. This is because general practitioners routinely record dosage instructions as free text rather than in a structured way. The objective was to develop and assess the validity of an automated algorithm to derive the daily dose from text dosage instructions.

Methods

A computer program was developed to derive numerical information from unstructured text dosage instructions. It was tested on dosage texts from a random sample of one million prescription entries. A random sample of 1000 of these converted texts were manually checked for their accuracy.

Results

Out of the sample of one million prescription entries, 74.5% had text containing the daily dose, 14.5% had text but did not include a quantitative daily dose statement and 11.0% had no text entered. Of the 1000 texts which were checked manually, 767 stated the daily dose. The program interpreted 758 (98.8%) of these correctly, produced errors in four cases and failed to extract the dose from five texts.

Conclusions

An automated algorithm has been developed which can accurately extract the daily dose from almost 99% of general practitioners' text dosage instructions. It increases the utility of GPRD and other prescription data sources by enabling researchers to estimate the duration of drug exposure more efficiently. Copyright © 2005 John Wiley & Sons, Ltd.
Optical and electrochemical properties of copoly(aryl ether)s consisting of alternate 2,5‐distyrylbenzene and electron‐transporting oxadiazole or triazole derivatives
Authors: Chen Shinn‐Horng , Chen Yun
Published: September 2005

New copoly(aryl ether) P1 consisting of alternate electron‐transporting 2‐(3‐(trifluoromethyl)phenyl)‐5‐(4‐(5‐(3‐(trifluoromethyl)phenyl)‐1,3,4‐oxadiazol‐2‐yl)‐2,5‐bis(hexyloxy)phenyl)‐1,3,4‐oxadiazole and hole‐transporting 2,5‐distyrylbenzene (DSB) was synthesized via nucleophilic substitution polymerization. We investigated the optical and electrochemical properties of alternate copoly(aryl ether)s P1–P6, which contain the same hole‐transporting DSB segments, but with different electron transporting segments. The effect of trifluoromethyl groups in electron transporting segments is also discussed. Referencing to the spectra of their model compounds M1–M4, the emissions of P1–P3 are dominated exclusively by the hole‐transporting fluorophores with longer emissive wavelength about 452–453 nm via efficient excitation energy transfer. Furthermore, P1–P3 also exhibit unique variations in energy transfer in acidic media and solvatochromism in organic solvents. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of P1–P4, estimated from electrochemical data, are −5.12, −5.15, −5.18, −5.00 eV and −2.93, −3.39, −3.49, −2.76 eV, respectively. The electron and hole affinity of P1–P6 can be enhanced simultaneously by introducing isolated hole‐ and electron‐transporting segments in backbone. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5083–5096, 2005
Syntheses of graft and star copolymers possessing polyolefin branches by using polyolefin macromonomer
Authors: Kaneko Hideyuki , Kojoh Shin‐ichi , Kawahara Nobuo , Matsuo Shingo , Matsugi Tomoaki , Kashiwa Norio
Published: September 2005

Graft and star copolymers having poly(methacrylate) backbone and ethylene–propylene random copolymer (EPR) branches were successfully synthesized by radical copolymerization of an EPR macromonomer with methyl methacrylate (MMA). EPR macromonomers were prepared by sequential functionalization of vinylidene chain‐end group in EPR via hydroalumination, oxidation, and esterification reactions. Their copolymerizations with MMA were carried out with monofunctional and tetrafunctional initiators by atom transfer radical polymerization (ATRP). Gel‐permeation chromatography and NMR analyses confirmed that poly(methyl methacrylate) (PMMA)‐g‐EPR graft copolymers and four‐arm (PMMA‐g‐EPR) star copolymers could be synthesized by controlling EPR contents in a range of 8.6–38.1 wt % and EPR branch numbers in a range of 1–14 branches. Transmission electron microscopy of these copolymers demonstrated well‐dispersed morphologies between PMMA and EPR, which could be controlled by the dispersion of both segments in the range between 10 nm and less than 1 nm. Moreover, the differentiated thermal properties of these copolymers were demonstrated by differential scanning calorimetry analysis. On the other hand, the copolymerization of EPR macromonomer with MMA by conventional free radical polymerization with 2,2′‐azobis(isobutyronitrile) also gave PMMA‐g‐EPR graft copolymers. However, their morphology and thermal property remarkably differed from those of the graft copolymers obtained by ATRP. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5103–5118, 2005
A local‐probe analysis of the rheology of a "solid liquid"
Authors: Houston J. E.
Published: September 2005

Results are shown demonstrating the application of the interfacial force microscope to a study of the micro‐scale mechanical properties of an extreme example of a viscoelastic material, one that is often referred to as a “solid liquid.” Experiments involve relaxation measurements taken over a range of deformations, to establish linearity, and scaled according to the optically determined contact radius. In addition, the data is Fourier analyzed to obtain the frequency response of both the real and imaginary components of the shear modulus. The results from such an analysis of a single 3 s measurement are shown to be in remarkable agreement with published results from a series of single‐frequency measurements using a classical rheometer. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2993–2999, 2005
Morphology study of Nafion membranes prepared by solutions casting
Authors: Lin Hsiu‐Li , Yu T. Leon , Huang Cheng‐Hung , Lin Tsang‐Lang
Published: September 2005

The structures of Nafion membranes prepared by solutions casting from low aliphatic alcohols/water mixture solvents and N,N′‐dimethyl formamide (DMF) solvent were investigated using differential scanning calorimeter and small angle X‐ray scattering. The aggregation behavior of Nafion molecules in the casting solutions was also investigated using dynamic light scattering. We show that the morphology of membranes was strongly influenced by the conformations of Nafion molecules in the solutions. In aliphatic alcohol/water mixture solvents, which have a worse compatibility with Nafion backbones, the Nafion molecules aggregate and form fringed rod‐like structures. These primary rod‐like structures then aggregate again through fringed side chains to form secondary ionic aggregations. In DMF solvent, owing to its better compatibility with Nafion backbones, less Nafion molecules aggregate. The high degree of Nafion molecular aggregations in aliphatic alcohol/water mixture solvents leads to a high degree of hydrophobic and hydrophilic phase separation for membranes prepared by casting from Nafion/aliphatic alcohol/water solutions. However, the lower degree of molecular aggregations in DMF solvent results in a lower degree of hydrophobic and hydrophilic phase separation for membranes prepared by casting from Nafion/DMF solution. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3044–3057, 2005
Effects of ultrasonic oscillations on linear viscoelastic behaviors of metallocene‐catalyzed linear low density polyethylene and its blends with low density polyethylene
Authors: Wu Hong , Guo Shaoyun , Li Zhen
Published: September 2005

The effects of ultrasonic oscillations on linear viscoelastic behaviors of metallocene‐catalyzed linear low density polyethylene (mLLDPE) and its blends with low density polyethylene (LDPE) were investigated in this article. The experimental results showed that ultrasonic oscillations can increase the cross modulus, characteristic time, plateau modulus, complex viscosity, zero shear viscosity, and flow activation energy of mLLDPE. Molecular weight of mLLDPE increases but molecular polydispersity index decreases in the presence of ultrasonic oscillations. It has been found for mLLDPE/LDPE blends that the addition of LDPE as well as ultrasonic oscillations can decrease the cross modulus but increase the characteristic time of the blends. The complex viscosity, zero shear viscosity, and flow activation energy of the blends increase by the addition of LDPE, but decrease in the presence of ultrasonic oscillations. Shear thinning effect of the blends is improved because of the addition of LDPE. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3030–3043, 2005
Restoration of PSD from Chord Length Distribution Data using the Method of Projections onto Convex Sets
Authors: Worlitschek Jörg , Hocker Thomas , Mazzotti Marco
Published: September 2005

The interpretation of chord length distributions (CLDs) is essential in many fields and has been discussed by various authors. Here, the technique of the Focused Beam Reflectance Measurement (FBRM) is considered as on‐line and in‐situ measurement device of the CLD of particle dispersions and emulsions. Though useful in general, this measurement cannot be converted directly into a particle size distribution (PSD), unless the physics of the measurement method is described and accounted for. In this work we present a new tool to carry out such a conversion once the particle shape is known a priori and can be fixed, which is based on a two step procedure: (1) the computation of a matrix that converts the PSD of a population of particles with given shape into the corresponding CLD using a 3‐dimensional geometric model; (2) the calculation of the PSD from the resulting linear matrix equation for the measured CLD. Here, the method of Projections onto Convex Sets (POCS) is applied to solve the PSD restoration problem, which is a mathematically ill‐posed inverse problem. We study the effect of particle shape and matrix dimension on the ill‐posed character of the inverse problem. A detailed error analysis of the CLD allows for a predictive description of a posteriori constraints in the POCS framework. We discuss the application of this method to the characterization of simulated test cases and experimentally obtained data.
A global approach for reducing risks in hydrogenation operations
Authors: Karayigitoglu Cigdem , Holroyde John
Published: September 2005

Pfizer API manufacturing consists of 16 sites around the world and represents a large manufacturing capability. This network has expanded in recent years through mergers. This community of manufacturing sites represents a wide range of practical knowledge for conducting safe API (active pharmaceutical ingredient) manufacturing. Taking advantage of this wealth of experience, Pfizer manufacturing operations performed a global survey of hydrogenation current practices. From the information gathered, a “Hydrogen and Catalyst Handling Good Practice” guide was developed that covered the facility design and operational practices. The team that developed the “Good Practice” guide is also involved in overseeing the implementation of the recommended practices at all manufacturing sites conducting hydrogenations. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Reliable and effective inerting methods to prevent explosions
Authors: Hoppe Tom , Jaeger Norbert
Published: September 2005

This paper gives guidance on the use of inerting in the processing industry. It explains the different types of inerting methods available, the technical requirements for implementation of the methods, and their limitations. The report is intended to assist workers in plants with operations that need to be protected by inerting and reflects the present state of the art and current knowledge of the assessment and requirements associated with inerting. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Microstructural properties of Bi1.65Pb0.35Sr2Ca2Cu3O10+δ and Bi1.65Pb0.35Sr2CaCu2O8+δ ceramic samples through transport measurements: a comparative study
Authors: Govea‐Alcaide E. , Jardim R. F. , Muné P.
Published: September 2005

We have studied in detail the dependence of the electrical resistivity as a function of temperature of Bi1.65Pb0.35Sr2Ca2Cu3O10+δ ((Bi,Pb)‐2223) and Bi1.65Pb0.35Sr2CaCu2O8+δ ((Bi,Pb)‐2212) ceramic samples. Both types of samples were obtained by a solid‐state reaction method and pressed uniaxially at different compacting pressures ranging from 90 to 600 MPa before the last heat treatment. From electrical resistivity measurements as a function of temperature, we were able to separate contributions arising from both the grains' misalignment and microstructural defects, by using a current‐conduction model. The results suggest that in both compounds the texture degree and the connectivity between grains are improved with increasing compacting pressures. It was found that in the (Bi,Pb)‐2223 samples, even in those obtained at low compacting pressures, the grains exhibit a preferential orientation. A similar effect, but less pronounced, was observed in the (Bi,Pb)‐2212 samples. In both cases, the behavior is different to the one reported in YBCO ceramic samples, in which the grains exhibit random orientation. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effects of Nd impurity on the optical, dielectric and electrical properties of PbWO4 single crystals
Authors: Li Weifeng , Huang Hongwei , Feng Xiqi
Published: September 2005

A series of Nd‐doped PbWO4 (PWO) crystals are grown using the Czochralski method and their optical and electrical properties are investigated. It is found that the Nd3+ ion characterizes the optical absorption spectra of Nd‐containing crystals. On increasing the concentration of Nd, the optical absorption edge of the crystals shifts to low energy, which results from the defect energy level effect. Similar to other trivalent rare‐earth ions, the improvement of radiation hardness is also achieved in Nd‐doped PWO. Impedance spectroscopy reveals two dielectric loss peaks, which are assigned to [2($ {\rm Nd} ^{3+}_{\rm Pb} $)•–(VPb)″] and [($ {\rm Nd} ^{3+}_{\rm W} $)′′′–($ {\rm Nd} ^{3+}_{\rm Pb} $)•–(VO)••] defect complexes, respectively. High electrical conductivity with an activation energy of about 0.29 ± 0.02 eV at high temperature is present in PWO containing 1.6% Nd. It is of interest that the heavily Nd‐doped PWO could be a high‐temperature ionic conductor. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Luminescence and storage properties of CsBr:Cu and CsBr:CuO crystals
Authors: Zorenko Yu. , Turchak R. , Voznjak T. , Batentschuk M. , Osvet A. , Winnacker A.
Published: September 2005

The absorption, photoluminescence, photo‐stimulated luminescence (PSL) and emission decay of CsBr:Cu and CsBr:CuO crystals have been studied for estimation of the application possibilities of the compounds based on CsBr:Cu as a storage phosphors. The role of the Cu2+ and Cu+ ions in the PSL proceses of the CsBr:Cu compounds was considered. The comparison with the storage properties of the CsBr:Cu and CsBr:CuO crystals with the CsBr:Eu crystals have been provided. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interfacial modification of amorphous substrates for microcrystalline silicon growth with in situ hydrogen plasma pretreatment
Authors: Park Young‐Bae , Rhee Shi‐Woo , Li Xiaodong
Published: September 2005

Microcrystalline silicon (µc‐Si:H) films have been deposited onto hydrogenated and amorphous Si‐rich silicon nitride and thermal oxide substrates with silane (SiH4)–hydrogen (H2) in remote plasma‐enhanced chemical vapor deposition (RPECVD) at 250 °C, and these films have been investigated. It is found that in situ hydrogen plasma pretreatment of the amorphous substrates prior to µc‐Si:H deposition is effective in reducing the interfacial amorphous transition region. It is believed that this hydrogen plasma pretreatment gives adsorption and nucleation sites by breaking weak Si–N and Si–Si bonds and also removes native Si–O x and hydrocarbon impurities. In the case of SiNx:H surface, surface roughening from atomic hydrogen etching and surface cleaning effects are greater than those for stable thermal oxide. Surface crystallization at the initial stage of the growth can be obtained on amorphous substrate at low temperature without an a‐Si transition layer. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optoelectronic and electrical properties of TlGaS2 single crystal
Authors: Qasrawi A. F. , Gasanly N. M.
Published: September 2005

The optoelectronic and electrical properties of TlGaS2 single crystals have been investigated by means of room temperature transmittance and reflectance spectral analysis, Hall coefficient, dark electrical resistivity and photocurrent measurements in the temperature range of 200–350 K. The optical data have revealed an indirect and direct allowed transition band gaps of 2.45 and 2.51 eV, an oscillator and dispersion energy of 5.04 and 26.45 eV, respectively, a static dielectric constant of 6.25 and static refractive index of 2.50. The dark Hall coefficient measurements have shown that the crystals exhibit a conductivity type conversion from p‐type to n‐type at a critical temperature of 315 K. Deep donor and acceptor energy levels of 0.37/0.36 eV and 0.66 eV has been calculated from the temperature dependence of Hall coefficient and resistivity, and photocurrent measurements, respectively. The photocurrent decreases with decreasing temperature. The analysis of the photocurrent data have revealed that, the recombination mechanism is linear and supralinear above and below 290 K, respectively. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fine‐grained sediment in river systems: environmental significance and management issues
Authors: Owens P. N. , Batalla R. J. , Collins A. J. , Gomez B. , Hicks D. M. , Horowitz A. J. , Kondolf G. M. , Marden M. , Page M. J. , Peacock D. H. , Petticrew E. L. , Salomons W. , Trustrum N. A.
Published: September 2005

Fine‐grained sediment is a natural and essential component of river systems and plays a major role in the hydrological, geomorphological and ecological functioning of rivers. In many areas of the world, the level of anthropogenic activity is such that fine‐grained sediment fluxes have been, or are being, modified at a magnitude and rate that cause profound, and sometimes irreversible, changes in the way that river systems function. This paper examines how anthropogenic activity has caused significant changes in the quantity and quality of fine‐grained sediment within river systems, using examples of: land use change in New Zealand; the effects of reservoir construction and management in different countries; the interaction between sediment dynamics and fish habitats in British Columbia, Canada; and the management of contaminated sediment in USA rivers. The paper also evaluates present programmes and initiatives for the management of fine sediment in river systems and suggests changes that are needed if management strategies are to be effective and sustainable. Copyright © 2005 John Wiley & Sons, Ltd.
Hydrogeomorphic processes affecting riparian habitat within alluvial channel–floodplain river systems: a review for the temperate zone
Authors: Steiger J. , Tabacchi E. , Dufour S. , Corenblit D. , Peiry J.‐L.
Published: September 2005

Hydrogeomorphic processes within alluvial river systems create, maintain and degrade riparian habitat. The dynamic interactions between water, sediment, aquatic–terrestrial landforms and biotic elements control the functional processes and biodiversity patterns within the riparian zone and, thus, contribute directly to their ecological integrity and societal value. Numerous researchers from different disciplines publish work on the physical, biological, economic and societal functions of the riparian zone within various physiographic areas. The present paper aims to review the hydrogeomorphic processes of unconfined alluvial channel–floodplain rivers within the temperate zone. These processes and their interactions with the biotic environment provide the basis for understanding the physical as well as the ecological functioning of fluvial hydrosystems. The review focuses mainly on the European context, but major advances in riparian research from other continents are also considered. Rehabilitation and management strategies for the riparian zone are summarized and recommendations for further research conclude this review. Copyright © 2005 John Wiley & Sons, Ltd.
Land‐use change, sediment production and channel response in upland regions
Authors: Liébault Frédéric , Gomez Basil , Page Mike , Marden Mike , Peacock David , Richard Didier , Trotter Craig M.
Published: September 2005

Human‐induced modifications of the vegetation cover in river basins may cause strong geomorphic responses by disturbing sediment supply, transport and deposition regimes. The response is particularly noticeable in upland regions, where sensitivity to change is enhanced by strong coupling between river channels and hillslopes, as is exemplified by studies undertaken in the East Coast region, North Island, New Zealand, and in the Southern French Prealps. Both regions have been affected by land‐use change during the past 150 years (deforestation and reforestation) that can be chronologically linked to geomorphic change on hillslopes and on valley floors. In this paper we use these studies to draw attention to: (1) the magnitude of the change in sediment production associated with a modification to the vegetation cover; (2) the impact that reforestation has on the sediment production and the channel system; and (3) the relative influence of anthropogenic and climatic forcing on the channel response. Finally, we consider the manner in which land use has been used as a tool to manage sediment production in France and New Zealand. The results obtained in both regions demonstrate the strong effect that the vegetation cover has on hillslope erosion processes, through its impact on the landsliding threshold (in New Zealand) and the total sediment yield (from paired forested and non‐forested catchments in France). Consideration of channel response serves to emphasize the sensitivity of upland regions to land‐use change, and suggests that the successful discrimination between the respective influences of climatic and land‐use change depends, in large part, upon the ability to detect spatial and chronological links (or, conversely, gaps) between causes and effects. Copyright © 2005 John Wiley & Sons, Ltd.
A review of techniques available for delimiting the erodible river corridor: a sustainable approach to managing bank erosion
Authors: Piégay H. , Darby S. E. , Mosselman E. , Surian N.
Published: September 2005

Traditional policies for managing river bank erosion are currently being reconsidered as a result of increased awareness regarding the unsustainable nature of some forms of bank protection, and the role played by bank erosion in providing ecosystem services and supporting geomorphological functions. River managers are therefore increasingly seeking to preserve bank erosion within a defined erodible corridor. This paper provides an overview of the erodible corridor concept, focusing on the provision of guidelines for applying the concept in practice. We argue that a nested approach is required to address management objectives across a range of scales (network scale, reach scale, local scale) and review the different geomorphic tools that are available to help managers define the extent and inner sensitivity of the erodible corridor. These tools include simple rules of thumb such as evaluation of the equilibrium meander amplitude, historical approaches based on overlays of historical channel position, and simulation modelling. The advantages and limitations of each of these tools are discussed. Copyright © 2005 John Wiley & Sons, Ltd.
Pre‐ and post‐reforestation gully development in Mangatu Forest, East Coast, North Island, New Zealand
Authors: Marden Michael , Arnold Greg , Gomez Basil , Rowan Donna
Published: September 2005

Following clearance of the indigenous forest and conversion of the land to pasture early in the 20th century, gully erosion became a pervasive feature in the headwaters of the Waipaoa River basin, and was notably problematic in the 140‐km2 area now covered by the Mangatu Forest. In this area, before reforestation in 1961, gully erosion affected c. 4% of the terrain. After a 24‐year exotic reforestation programme the area affected by gullies was reduced to 1.5%, but of the eight gullies larger than 10 ha in 1960 none had stabilized by 1988, although four had at least halved in size. Estimates that a gully will stabilize or increase in size under a range of conditions suggest that in the case of gullies < 1 ha in area, formed in terrain underlain by Cretaceous rock, there is a > 80% probability of stabilization after one forest rotation (c. 24 years). For gullies between 1 and 5 ha in area the probability of stabilization is c. 60%. Gullies of 5 ha have an even chance of stabilizing over the time frame of a single rotation. The key determinant is gully size and shape at the time of planting and, within this size range, these relationships were stronger for linear than for amphitheatre‐shaped gullies. Between 1939 and 1988 sediment production from gullies in the portion (76%) of the Mangatu Forest underlain by Cretaceous‐aged rock was c. 22 000 t km−2 yr−1, and during the period of maximum sediment production (1939–1960) they may have accounted for c. 17% of the Waipaoa River's average annual suspended sediment load. Reforestation reduced the contribution to c. 8% in the period between 1970 and 1988. However, the off‐site (downstream) impact of sediment generated by the remaining 420 active gullies in the Waipaoa River catchment is significant, not least on the capacity of the scheme that protects high‐value agricultural land on the Poverty Bay Flats from flooding. A targeted reforestation programme may be an alternative to raising the height of the existing artificial levees. It is estimated that additional exotic plantings totalling c. 15 400 ha (c. 7% of the Waipaoa River basin area) would produce a > 64% reduction in sediment production from gullies on pastoral hillslopes within one forest rotation (c. 24 yr). Copyright © 2005 John Wiley & Sons, Ltd.
Response of a river sediment budget after historical gravel mining (the lower Tordera, NE Spain)
Authors: Rovira A. , Batalla R. J. , Sala M.
Published: September 2005

The channel of the lower Tordera River (Catalan Coastal Ranges) was intensively mined between 1956 and 1987, at an extraction rate 14 times higher than the replenishment rates. Mining caused incision of up to 2 m over the whole reach, leading to damage of infrastructures and affecting the groundwater system. In this paper we analyse the response of the river sediment budget by means of sediment transport measurements (both in suspension and as bedload) and topographic surveys. Historical data on mining activities was used to verify current values of sediment transport and to locate the main extraction areas in the long profile of the river. This has led to an integrated methodology that can be useful for assessing and managing current and future sediment deficits in heavily mined rivers. In the lower Tordera, a minimum of 3 million cubic metres of sand and gravel were extracted, especially from two gravel pits still visible as concavities in the river's longitudinal profile. Nowadays, 15 yr after mining ceased, the river shows during dry periods a general tendency towards aggradation (3.6 mm yr−1 on average and up to 12 mm yr−1 in central sections where mining took place), but a slight long‐term tendency to erode the riverbed. Sediment yield at the entrance of the study reach attains 552 000 t yr−1, while net sediment deposition reaches 16 400 t yr−1 (78% as bedload), mostly during small floods in dry periods. Estimated time for the river to recover pre‐extraction bed‐level is of the order of 420 yr. Copyright © 2005 John Wiley & Sons, Ltd.
Modulating T cell signaling cascades by HMG‐CoA reductase inhibitors
Authors: Waiczies Sonia , Prozorovski Timour , Zipp Frauke
Published: September 2005

The modulation of undesirable immune responses is a novel and exciting property of statins. These drugs were initially designed to lower lipid levels by specifically inhibiting the rate‐limiting enzyme HMGCR (3‐hydroxy‐3‐methylglutaryl (HMG)‐CoA reductase; EC 1.1.1.88; standard protein abbreviation HMG‐CoA reductase), which is important for cholesterol synthesis. Various mechanisms accounting for the anti‐inflammatory properties of statins have been proposed: preliminary studies reported an interference in MHC class II presentation necessary for transmitting antigen‐specific signals to T cells but subsequently a direct impact on various intracellular T cell molecules independent of antigen presentation or T cell receptor triggering was also reported. Several groups including ours have recently reported the benefits of treating various animal models of T cell‐mediated autoimmune disorders such as multiple sclerosis and rheumatoid arthritis with HMGCR inhibitors. Although a plethora of molecular processes have been reported, the main biological alterations responsible for modulating T cell response by statins involve (I) a direct interference in T cell cycle progression and induction of anergy and (II) a shift in the differentiation status of T‐helper (Th) effector cells towards a regulatory phenotype. The impact of statins on the T cellular immune response is discussed here in detail.
New aspects regarding mechanisms of tissue damage in the course of autoimmune demyelination
Authors: Aktas Orhan
Published: September 2005

Multiple sclerosis (MS) is a chronic demyelinating disease of the central nervous system (CNS) and the major cause of neurological disability in young adults in Western countries. Over the last decades, it has become evident that the immune system specifically attacks the myelin sheath within the CNS and induces recurrent or persisting neurological deficits in patients. This review focuses on selected new aspects of the underlying mechanisms linking autoimmune demyelination and irreversible brain tissue damage in the course of MS and its animal model, experimental autoimmune encephalomyelitis.
Mitogen activated protein kinase signaling in the kidney: target for intervention?
Authors: de Borst Martin H. , Wassef Lesley , Kelly Darren J. , van Goor Harry , Navis Gerjan
Published: September 2005

Mitogen activated protein kinases (MAPKs) are intracellular signal transduction molecules, which connect cell‐surface receptor signals to intracellular processes. MAPKs regulate a range of cellular activities including cell proliferation, gene expression, apoptosis, cell differentiation and cytokine production. The MAPK superfamily consists of at least four families: extracellular signal‐regulated kinase (ERK), p38 MAPK, Jun‐NH2‐terminal kinase (JNK), and ERK5. Each of these families exerts particular downstream effects, although interactions have been described. MAPK activity is present in the normal kidney. Moreover, in various types of renal disease, renal MAPK expression is increased. Interventions that provide renoprotection, such as ACE‐inhibition or statin therapy, may reduce renal MAPK expression, suggesting that increased renal MAPK expression is involved in the pathophysiology of renal damage. Studies using specific MAPK inhibitors have been used to further elucidate this role. This review gives an overview of available in vitro data on MAPK activation (focussed on renal cell types), and describes MAPK localization and possible functions in the normal and diseased kidney in man, and in experimental renal disease. Studies reporting the effect of conventional renoprotective intervention on renal MAPK expression are reviewed, as well as the available data on specific MAPK inhibition, both in the clinical and experimental setting. The available data appear to support the potential of MAPK inhibition as a novel intervention strategy in renal disease, but future clinical studies are needed to substantiate this assumption, and to establish its safety.
Protective role of thioredoxin‐1 in cardiovascular systems
Authors: Haendeler Judith
Published: September 2005

The thioredoxin‐1 (Trx‐1) system consists of two oxidoreductases, the thioredoxin‐reductase and Trx‐1. Trx‐1 is a ubiquitously expressed oxidoreductase. The cellular functions of Trx‐1 are wide range. They include protein disulfide reduction, DNA synthesis, protection from apoptosis, redox regulation of a variety of proteins transcription factors and reduction of H2O2, respectively. This review will first focus on the essential role for Trx‐1 in different cardiovascular cells, namely smooth muscle cells, endothelial cells and cardiomyocytes. Thereby, the review will demonstrate the predominant role of Trx‐1 to limit oxidative stress directly due to reactive oxygen species scavenging and by protein‐protein interaction with key signaling molecules. Furthermore, the review will focus on important in vivo studies showing a protective role of Trx‐1 in different cardiovascular diseases. Thus, the Trx system and Trx‐1 could be important future targets to develop clinical therapies for cardiovascular disorders.
Individualization of Single‐Walled Carbon Nanotubes: Is the Solvent Important?
Authors: Kim Dong Sik , Nepal Dhriti , Geckeler Kurt E.
Published: September 2005

The influence of different solvents on the individualization of single‐walled carbon nanotubes (SWNTs) was investigated by several methods. A stable solution of individual SWNTs in o‐dichlorobenzene was obtained by a combination of ultrasonication and ultracentrifugation. Atomic force microscopy height analysis confirmed that the final supernatant solution contained 85 % of individual tubes with a diameter equal to or less than 1.5 nm, which is consistent with the average diameter of arc‐discharge tubes. Both the solvent and the ultracentrifugation speed are important parameters in determining the final degree of individualized SWNTs. Notably, the SWNTs were stable in o‐dichlorobenzene for more than eight months. This technique for obtaining highly individualized SWNTs in an organic solvent is expected to have great potential in many applications, such as functional materials and nanoelectronics.
Ultrasound diagnosis of fetal macrosomia: a comparison of weight prediction models using computer simulation
Authors: Mongelli M. , Benzie R.
Published: September 2005

Objective

To assess the frequency of the diagnosis of macrosomia in relation to differing weight estimation formulae in unselected pregnancies.

Methods

Computer modeling techniques were employed. Computer modeling software generated correlated fetal biometry measurements according to published British standards, from 37 to 41 weeks' gestation. For each set of measurements, estimated fetal weights were obtained by a panel of 18 ultrasound weight formulae. The diagnosis of macrosomia was made if the fetal weight estimate was greater than 4500 g. Cohorts of 5000 pregnancies for each week of gestation were studied.

Results

The frequency of diagnosis of macrosomia increased progressively with advancing gestational age, with large increases between 40 and 41 weeks. The type of weight estimation formula had a profound influence on the frequency of diagnosis of macrosomia. Five of the formulae tested almost never returned a weight estimate greater than 4500 g. Three formulae yielded false positive rates in excess of 15%. The Hadlock group of formulae yielded frequencies of 0.3% to 14.6%.

Conclusions

Most formulae tend to over‐diagnose macrosomia at term. Intervention rates for suspected fetal macrosomia may be influenced by gestational age at the time of scan and the type of fetal weight estimation formula in use. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Proton computed tomography as a tool for proton therapy planning: preliminary computer simulations and comparisons with x‐ray CT basics
Authors: Teixeira de Assis Joaquim , Yevseyeva, Olga , Evseev Ivan , Lopes Ricardo Tadeu , Schelin Hugo Reuters , Loss Klock Márgio Cezar , Paschuk Sergei A. , Schulte Reinhard W. , Williams David C.
Published: September 2005

Proton beams can destroy tumors better than other radiation treatment options because they deliver their energy in a very accurate way, while leaving the surrounding tissue undamaged. However, it requires a very accurate prediction of the Bragg peak position within the patient's body. In existing proton treatment centers, the dose calculations are performed based on x‐ray computed tomography (CT) and the patient is positioned with x‐ray radiographs. During the 1970s and early 1980s, it was shown that the use of proton beams rather than conventional x‐rays could have some advantages. With the development of specialized medical proton gantries at Loma Linda University Medical Center (USA) and several other proton treatment centers worldwide, interest in this question has been renewed. The modern approach has advanced from simple proton film radiography to CT reconstructions from proton energy loss measurements employing individual proton tracking techniques. This permits image degradation due to multiple Coulomb scattering, one of the main problems of proton CT, to be reduced. Current work is devoted to the comparison of conventional x‐ray CT and proton computed tomography (pCT) as two alternative tools for measuring the physical properties of the human body, required for proton treatment planning. In this paper, a brief comparative overview of the physical basics of both methods are followed by the analysis of Monte Carlo simulation results. The first‐generation CT scheme was assumed for simplicity. The precisions relative to water volumetric electron density distributions, extracted from CT and pCT images, and the sources of absolute errors are discussed. Copyright © 2005 John Wiley & Sons, Ltd.
Density‐dependent regulation in populations of potato‐colonizing aphids
Authors: Alyokhin Andrei , Drummond Francis A. , Sewell Gary
Published: September 2005

Scarcity of long‐term (over 30 years) data series represents a major challenge for an accurate estimation of the role of density‐dependent processes in population regulation. We analyzed population densities of the wingless parthenogenic morphs of buckthorn aphid (BA), Aphis nasturtii Kaltenbach, potato aphid (PA), Macrosiphum euphorbiae (Thomas), and green peach aphid (GPA), Myzus persicae (Sulzer) from 1949 to 2003 for signs of density‐dependent regulation. We found strong evidence of density‐dependent regulation, with detection of density dependence being fairly consistent among the different statistical techniques. Direct density dependence was detected for the populations of all three species. There was also evidence of delayed density dependence for PA. The periodicity of population fluctuations for BA and GPA was 6.1 years and 3.9 years, respectively. The periodicity for PA was not explicit, being highly variable throughout the time series. Effects of density‐independent weather factors were relatively minor compared to density‐dependent regulation. The BA populations experienced a significant reduction in both density and annual oscillations starting in 1995, while GPA populations experienced a similar reduction in 1991. No such change was apparent for PA. The most likely explanation for the observed phenomenon is a change in the composition of the lady beetle community following the establishment of two alien coccinellid species, and/or changes in insecticide use by commercial growers in the area of the study.
Disentangling the effects of capture efficiency and population abundance on catch data using random effects models
Authors: Trenkel Verena M. , Skaug Hans J.
Published: September 2005

We propose a random effects model for disentangling population abundance and capture efficiency effects on bottom-trawl catches. The spatial distribution of individual fish is assumed random leading to a Poisson distribution for the number of individuals in the trawl path (no schooling). Capture efficiency, i.e. the proportion of individuals in the trawl path being retained by the gear, is modelled as a random variable. We propose model extensions that include the effects of body size on haul efficiency. We applied the models to several species from the Celtic Sea groundfish community based on small-scale repetitive hauls. The resulting abundance estimates allowed us to study population abundance ratios; the estimated capture efficiencies were comparable between species and showed that generally gear efficiency increases for larger species with the exception of haddock (Melanogrammus aeglefinus), which had low estimated gear efficiency despite its large body size. Model identifiability was studied using simulations and an independent trawl data set from the same area.
Pioneer whalers in the Ross Sea, 1923–33
Authors: Barr William , Watt James P.C.
Published: September 2005

On Christmas Eve 1923, the whaling factory ship Sir James Clark Ross, commanded by Captain Carl Anton Larsen and accompanied by five catchers, reached the front of the Ross Ice Shelf; these were the first whaling vessels to operate in the Ross Sea. They had been dispatched by the Norwegian whaling company Hvalfangeraktienselskapet Rosshavet, which had obtained a licence from the British government. For most of the 1923–24 season, Sir James Clark Ross occupied an uneasy anchorage in the deep waters of Discovery Inlet, a narrow embayment in the front of the Ross Ice Shelf, while her catchers pursued whales widely in the Ross Sea. During that first season they killed and processed 221 whales (211 blue whales and 10 fin whales), which yielded 17,300 barrels of oil. During the next decade, with the exception of the 1931–32 season, Sir James Clark Ross and two other factory ships operated by Rosshavet, C.A. Larsen and Sir James Clark Ross II, operated in the Ross Sea. From the 1926–27 season onwards these ships were joined by up to three other factory ships and their catchers, operated by other companies. During the decade 1923–33 the Rosshavet ships killed and processed 9122 whales in the Ross Sea sector, mainly in the open waters of the Ross Sea south of the pack-ice belt. Total harvest for all factory ships from the Ross Sea sector for the period was 18,238 whales (mainly blue whales) producing 1,490,948 barrels of oil. From 1924 onwards the Rosshavet catchers wintered in Paterson Inlet on Stewart Island, New Zealand, and from 1925 onwards a well-equipped shipyard, Kaipipi Shipyard, operated on Price Peninsula in Paterson Inlet to service the Rosshavet ships.
Radiocarbon dating of musk-ox (Ovibos moschatus) remains from northeast Greenland
Authors: Bennike Ole , Andreasen Claus
Published: September 2005

Northeast Greenland supports a large indigenous population of musk-oxen (Ovibosmoschatus). Radiocarbon dating of remains of this mammal collected on the terrain surface and from archaeological sites has yielded mid- and Late Holocene ages. The species probably arrived shortly before this part of Greenland became inhabited by the first hunter cultures. Only Late Holocene dates are available from the southern part of northeast Greenland, but the authors suggest that musk-ox spread south to this region at an early date, because there are no physical barriers. The lack of older dates may reflect the lack of palaeo-Eskimo sites with bones.
The men who sailed with Franklin
Authors: LLOYD-Jones RALPH
Published: September 2005

Using research methods well-known to family history investigators, it is possible to discover a remarkable amount of biographical information not merely on the officers, but also about the ratings who sailed — and died — with Sir John Franklin and Captain Francis Crozier on the 1845 Northwest Passage expedition. The findings from this research, mostly carried out at local and national archives in and around London, greatly enhances the understanding of that disaster, filling in gaps and answering questions raised by recent archaeological and forensic discoveries. This is the hitherto ignored social background to the last voyage of HMS Erebus and HMS Terror.