bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatio‐genetic population structure in mustached tamarins, Saguinus mystax
Authors: Huck Maren , Roos Christian , Heymann Eckhard W.
Published: February 2007

Dispersal and philopatry influence gene flow and thus the spatio‐genetic structure within and between populations. In callitrichids the flexible social and mating system corresponds with a variable migration pattern where both sexes might be philopatric or might disperse. We investigated the relationship between the spatio‐genetic structure and migration patterns in a population of mustached tamarins, Saguinus mystax. Using the rapidly evolving hypervariable region I (HVI) of the mitochondrial control region and 11 microsatellite markers we detected a high variation (HVI: 16 haplotypes in 69 individuals; microsatellites: HO = 0.75, average: 7.45 alleles/locus), with mating partners usually not sharing the same haplotype, indicating that matings are generally between partners that are not closely related. Similar high variance of haplotype differences for male‐male and female‐female pairs, along with a slightly higher number of haplotype differences in males show that both sexes habitually migrate. Spatial analyses suggest that females usually migrate longer distances, corresponding to very limited breeding positions for females in a polyandrous social mating system. Am J Phys Anthropol, 2007. © 2007 Wiley‐Liss, Inc.
Thermal oxidative degradation of bicomponent PP/PET fiber during thermal bonding process
Authors: Wang X. Y. , Gong R. H.
Published: January 2007

The effects of the thermal bonding temperature, dwell time, and the type of mold materials on the thermal oxidative degradation of the PP sheath of bicomponent fibers were investigated using the Fourier Transform Infrared Spectra (FTIR) and Thermal Gravimetry/Differential Scanning Calorimetry (TG‐DSC) techniques. The samples were prepared on a new 3D nonwovens process based on air‐laying and through‐air thermal bonding. The fiber material was a commercial polypropylene (PP)/polyester (PET) (sheath/core) bicomponent staple fiber. The results reveal that ketone developed following β‐scission in the thermally bonded nonwovens. The level of thermal oxidative degradation increases with increase in the bonding temperature, dwell time, and the thermal conductivity of the mold material. Such thermal oxidative degradation led to the slight widening of the melting peaks of the fiber PP sheath in the thermally bonded nonwovens, and a slight decreasing of melting point compared with those of the as‐received fiber. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 391–397, 2007
Microstructural transformation of wool during stretching with tensile curves
Authors: Liu Hongling , Yu Weidong
Published: January 2007

The microstructural transformation of wool fiber during the stretching process was investigated by the tensile tests and TEM micrograph observation. The results showed that water breaks some of the hydrogen bonds in the fiber, whereas the sodium bisulfite solution breaks some of the disulphide crosslinks between the peptide molecules, then the wool fiber is easy to be stretched. Two types of transformations were found during the stretching process, that is, the slippage of molecule chains or microstructural elements and the α→β transformation. The α→β transformation is dominant, in particular, during the low stretching rate process. In addition, the stretching slenderization tends to increase the tenacity of wool fiber and decrease its extension at break. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 816–822, 2007
Spherical cellulose–nickel powder composite matrix customized for expanded bed application
Authors: Xia Hai‐Feng , Lin Dong‐Qiang , Yao Shan‐Jing
Published: January 2007

Expanded bed adsorption (EBA) is an integrated technology for capturing target biomolecules directly from particle‐containing feedstock. The adsorbents are the key base to achieve the EBA process and should be designed specially. In present work a new type of composite particles for EBA application was prepared with cellulose as the skeleton, and nickel powder as the densifier through the method of water‐in‐oil suspension thermal regeneration. Two fractions of spherical particles with mean sizes of 101–119 μm and 168–217 μm were obtained and the effects of nickel powder addition on the physical properties of composite particles were analyzed. The results indicated that the cellulose–nickel powder composite particles prepared have appropriate wet density of 1.14–1.78 g/mL, water content of 51–75%, porosity of 81–93%, pore radius of 41–59 nm, and specific surface area of 30–42 m2/mL of wet particles. The bed expansion factor at the range of 2–3 was investigated and correlated with Richardson–Zaki equation. In addition, the bed stability with composite particles prepared was demonstrated with the observation of liquid mixing in expanded bed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 740–747, 2007
Kinetics of sulfur vulcanization of 1,4‐cis‐polyisoprene by differential scanning calorimetry
Authors: Kolesnikova N. N. , Ostroukhova O. A. , Popov A. A.
Published: January 2007

The vulcanization of 1,4‐cis‐polyisoprene was studied by differential scanning calorimetry under isothermal and nonisothermal conditions. On the basis of thermal characteristics obtained, the kinetic parameters of crosslinking (the induction period, maximum rate, and effective energy of activation) were determined. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 754–757, 2007
Surface modification and physical properties of various UHMWPE‐fiber‐reinforced modified epoxy composites
Authors: Lin S. P. , Han J. L. , Yeh J. T. , Chang F. C. , Hsieh K. H.
Published: January 2007

Two surface modification methods—plasma surface treatment and chemical agent treatment—were used to investigate their effects on the surface properties of ultrahigh‐molecular‐weight polyethylene (UHMWPE) fibers. In the analyses, performed using electron spectroscopy for chemical analysis, changes in weight, and scanning electron microscope observations, demonstrated that the two fiber‐surface‐modified composites formed between UHMWPE fiber and epoxy matrix exhibited improved interfacial adhesion and slight improvements in tensile strengths, but notable decreases in elongation, relative to those properties of the composites reinforced with the untreated UHMWPE fibers. In addition, three kinds of epoxy resins—neat DGEBA, polyurethane‐crosslinked DGEBA, and BHHBP‐DGEBA—were used as resin matrices to examine the tensile and elongation properties of their UHMWPE fiber‐reinforced composites. From stress/strain measurements and scanning electron microscope observations, the resin matrix improved the tensile strength apparently, but did not affect the elongation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 655–665, 2007
A functional polysiloxane with benzophenone derivative ultraviolet absorbing side groups: Synthesis, morphology, and its performance on fabrics
Authors: An Qiufeng , Li Linsheng , Lu Dedai , Huang Liangxian
Published: January 2007

A novel functional polysiloxane (PSBP) bearing benzophenone derivatives as UV absorbing side groups was synthesized by hydrosilylation of polyhydromethylsiloxane (PHMS) with 2‐hydroxy‐4‐(β‐hydroxy‐γ‐allyloxy)propyloxy benzophenone (HHAPB). The chemical structure, film morphology, and the softening fabric property of the synthesized polysiloxane were characterized and investigated by spectrum analysis, atomic force microscope (AFM), and Kawabata evaluation system. The experiment results indicated that PSBP was not only an excellent polymeric UV‐absorber, which showed intensive ultraviolet absorptions respectively, at wavelengths of 243.2, 288.2, and 325.4 nm, but could exhibit a nonhomogeneous, some rough structure film on silicon wafer substrate. In addition, the functional side group, benzophenone derivative as well as its mass ratio to PSBP has an influence on the performance of the synthesized polysiloxane. As the mass ratio decreased from 31.48 to 12.87%, the molar extinction coefficients εmax (λmax = 288.2 nm) of the PSBP fluids lowered from 3.4564 × 105 to 1.5763 × 105, but while the softening fabric properties of PSBP on cotton fabrics increased. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 680–687, 2007
Orbital period variation of the eclipsing binary system TT Herculis
Authors: Selam S. O. , Albayrak B.
Published: February 2007

New photoelectric UBV observations were obtained for the eclipsing binary TT Her at the Ankara University Observatory (AUO) and three new times of minima were calculated from these observations. The (O – C) diagram constructed for all available times of minima of TT Her exhibits a cyclic character superimposed on a quadratic variation. The quadratic character yields an orbital period decrease with a rate of dP /dt = –8.83 × 10–8 day yr–1 which can be attributed to the mass exchange/loss mechanism in the system. By assuming the presence of a gravitationally bound third body in the system, the analysis of the cyclic nature in the (O – C) diagram revealed a third body with a mass of 0.21M⊙ orbiting around the eclipsing pair. The possibility of magnetic activity cycle effect as a cause for the observed cyclic variation in the (O – C) diagram was also discussed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Poly(D,L‐lactide‐co‐glycolide acid) nanoparticles for DNA delivery: Waiving preparation complexity and increasing efficiency
Authors: Koby Gvili , Ofra Benny , Dganit Danino , Marcelle Machluf
Published: February 2007

When designing a nonviral gene delivery system based on polymeric nanoparticles (NPs), it is important to keep in mind obstacles associated with future clinical applications. Simplifying the procedure of NPs production and taking toxicity into account are the most important issues that need to be addressed. Toxicity concerns in clinical trials may be raised when using additives such as cationic polymers/lipids, buffering reagents, and proteins. Therefore, the aim of this study was to simplify the formulation of poly (lactide‐co‐glycolide) acid NPs by shortening steps such as sonication time and by avoiding the use of additives while preserving its efficiency. NPs (300 nm) were formulated using a modified w/o/w technique with DNA entrapment efficiency of 80%. Once achieving such NPs, formulation parameters such as DNA loading, release kinetics, DNA integrity and bioactivity, uptake by cells, and toxicity were addressed. The NPs were readily taken by several cell lines and were localized mostly in their endo‐lysosomal compartments. The NPs did not affect cells viability. Most importantly, transfection studies in COS‐7 and Cf2th cells resulted with a 250‐fold protein expression levels when compared with the control. These expression levels are higher than ones achieved with more complicated NPs systems, demonstrating the efficiency of our simplified NPs for gene delivery. © 2007 Wiley Periodicals, Inc. Biopolymers 85: 379–391, 2007.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Butanol production from agricultural residues: Impact of degradation products on Clostridium beijerinckii growth and butanol fermentation
Authors: Ezeji Thaddeus , Qureshi Nasib , Blaschek Hans P.
Published: February 2007

During pretreatment and hydrolysis of fiber‐rich agricultural biomass, compounds such as salts, furfural, hydroxymethyl furfural (HMF), acetic, ferulic, glucuronic, ρ‐coumaric acids, and phenolic compounds are produced. Clostridium beijerinckii BA101 can utilize the individual sugars present in lignocellulosic [e.g., corn fiber, distillers dry grain solubles (DDGS), etc] hydrolysates such as cellobiose, glucose, mannose, arabinose, and xylose. In these studies we investigated the effect of some of the lignocellulosic hydrolysate inhibitors associated with C. beijerinckii BA101 growth and acetone–butanol–ethanol (ABE) production. When 0.3 g/L ρ‐coumaric and ferulic acids were introduced into the fermentation medium, growth and ABE production by C. beijerinckii BA101 decreased significantly. Furfural and HMF are not inhibitory to C. beijerinckii BA101; rather they have stimulatory effect on the growth of the microorganism and ABE production. Biotechnol. Bioeng. 2007;97:1460–1469. © 2007 Wiley Periodicals, Inc.
Photochemical Production of Vitamin D2, Scale‐up and Optimization
Authors: Jike L. , Bei S. Y. , Yun M. J. , Li D. , Fang W. , Wei T. T.
Published: January 2007

An effective low cost method for the photochemical production of vitamin D2 has been studied, including a 200 L batch photoreactor and a continuous reactor. Following optimization of the irradiation time (550 min), initial concentration of ergosterol (1.4 mg/mL) and the number of lamps employed (16) for the batch reactor, the conversion of ergosterol is ca. 50 %, and the selectivity yield of pre‐vitamin D2 is ca. 84 %. The corresponding data for the continuous reactor are 73 % and 62 %, respectively.
Aufbereitung organischer Extraktphasen mittels Ultrafiltration bei der Schwermetallextraktion
Authors: Reinhart R. , Haseneder R. , Härtel G.
Published: January 2007

Ein Membranverfahren wie die Ultrafiltration ist prinzipiell zur Trennung von beladenem und unbeladenem Extraktionsmittel geeignet. Ferner besteht die Möglichkeit, durch die Kombination aus Laserscanner‐Messstand und Hochdruckmikrowaage Aussagen bezüglich Sorption und Quellung von Ultrafiltrationsmembranen sowohl anhand von gravimetrischen als auch optischen Messungen zu treffen. Aus den Ergebnissen der Permeationsversuche der eingesetzten Modellsubstanzen wird ersichtlich, dass sich das Aufkonzentrierungsverfahren mit Hilfe von Membranen aus regenerierter Cellulose sowohl für zwei‐ als auch dreiwertige Metallsalze eignet.
Modifizierung superabsorbierender Polymere mit hochkomprimiertem CO2
Authors: Schulz B. , Cleve E. , Krekel G. , Knopf K. , Cinquemani C.
Published: January 2007

Superabsorbierende Polymere, die man u. a. in Hygieneprodukten einsetzt, werden aus dem flüssigem und überkritischem CO2‐Zustand von 275 bar durch eine schnelle Expansion gebläht. Dadurch erzielte deutliche Veränderungen in der Oberflächenstruktur können durch rasterelektronenmikroskopische Aufnahmen (REM) erkannt werden. Messtechnisch lassen sich erhebliche Verbesserungen des Quellungsgrades und der Kinetik der Flüssigkeitsaufnahme bestimmen.
Entwicklung eines Thermogravimetrie‐Reaktors zur reaktionstechnischen Untersuchung heterogen katalysierter Reaktionen
Authors: Krautwald J. , Schnitzlein K.
Published: January 2007

Als Ersatz für den Standardtiegel in konventionellen Thermowaagen wird ein zwangsdurchströmter Thermogravimetrie‐Reaktor entwickelt, der kinetische Untersuchungen bei eindeutigen Strömungsverhältnissen erlaubt. Hierfür wird eine Kombination von numerischer Strömungssimulation und Experiment verwendet. Der Nachweis der Zwangsdurchströmung erfolgt mittels einer modifizierten Naphthalin‐Sublimationstechnik.
Optische Inline‐Messverfahren zur Zellzahl‐ und Zellgrößenbestimmung in der Bioprozesstechnik
Authors: Rudolph G. , Brückerhoff T. , Bluma A. , Korb G. , Scheper T.
Published: January 2007

Zur Beobachtung und Regelung von Kultivierungsprozessen werden zunehmend optische Sensoren verwendet. Wichtige Parameter für eine Kontrolle von Kultivierungsprozessen sind die Zellzahl, die Zellmorphologie und die Zellgrößenverteilung. Neben Trübungsmessverfahren werden auch bildgebende Verfahren für die Bestimmung dieser Prozessparameter eingesetzt. Ein Nachteil der meisten bisher entwickelten bildgebenden Verfahren ist, dass sie nur offline zur Verfügung stehen und somit Probenahmen erforderlich sind. Verfügbare bildgebende Inline‐Sonden können dagegen bis heute nur eine begrenzte Anzahl an Kultivierungsparametern bestimmen. In diesem Beitrag werden neue optische Verfahren vorgestellt, die für die Inline‐Bestimmung der Zellzahl, Zellgrößenverteilung und weiterer Parameter eingesetzt werden können. Speziell am Beispiel der In‐situ‐Mikroskopie wird ein bildgebendes Verfahren beschrieben, dass die Bestimmung direkter und indirekter Zellparameter in Echtzeit und ohne Probenahme erlaubt.
Berechnung des Druckverlustes in glatten konzentrischen Ringspalten bei ausgebildeter laminarer und turbulenter isothermer Strömung
Authors: Gnielinski V.
Published: January 2007

Doppelrohrapparate, die aus zwei ineinander gesteckten Rohren bestehen, werden als einfache Konstruktion u. a. in der Reaktionstechnik zur Wärmeübertragung verwendet. Die im Ringraum auftretende Reibung zwischen dem strömenden Medium und den Wänden führt zu einem Druckverlust des Strömungsmediums. Über den Reibungsbeiwert, der zur Berechnung des Druckverlusts benötigt wird, ist in den einschlägigen Handbüchern wenig zu finden.
Two‐Focus Fluorescence Correlation Spectroscopy: A New Tool for Accurate and Absolute Diffusion Measurements
Authors: Dertinger Thomas , Pacheco Victor , von der Hocht Iris , Hartmann Rudolf , Gregor Ingo , Enderlein Jörg
Published: February 2007

We present a new method to measure absolute diffusion coefficients at nanomolar concentrations with high precision. Based on a modified fluorescence correlation spectroscopy (FCS)‐setup, this method is improved by introducing an external ruler for measuring the diffusion time by generating two laterally shifted and overlapping laser foci at a fixed and known distance. Data fitting is facilitated by a new two‐parameter model to describe the molecule detection function (MDF). We present a recorded MDF and show the excellent agreement with the fitting model. We measure the diffusion coefficient of the red fluorescent dye Atto655 under various conditions and compare these values with a value achieved by gradient pulsed field NMR (GPF NMR). From these measurements we conclude, that the new measurement scheme is robust against optical and photophysical artefacts which are inherent to standard FCS. With two‐focus‐FCS, the diffusion coefficient of 4.26×10−6cm2 s−1for Atto655 in water at 25 °C compares well with the GPF NMR value of 4.28×10−6cm2 s−1.
Pulsed Electrical Discharge in Bubbled Water
Authors: Gershman S. , Mozgina O. , Belkind A. , Becker K. , Kunhardt E.
Published: February 2007

Electrical discharges in water are used for generating hydrogen peroxide, ozone, hydroxyl and oxygen radicals, and other chemically active species for disinfection and purification of water. The interest in electrical discharges in bubbled water is motivated by the need to reduce the power consumption for igniting the discharge. Understanding the electrical and optical characteristics of the discharge will help guide the design of future purification systems. Here we report results of investigations that focus on the study of pulsed electrical discharges in a single bubble of oxygen or argon in water. The single‐bubble system consists of a negative needle electrode inside a gas bubble in water and a disk electrode separated from the needle electrode by 5 –10 mm of water. The bubble is stationary and is subjected to repeated 3 – 15 kV, 1 μs long voltage pulses. At these voltage levels, the discharge process is confined to the bubble with the water serving as a dielectric material covering the disk electrode. During a single voltage pulse multiple ∼100 ns long discharges occur in the bubble. These discharges deposit sufficient amount of charge on the surface of the bubble to generate a reverse‐polarity discharge during the voltage shut‐off. Experiments with Ar and O2 bubbles show the same optical emission intensity at 309 ± 5 nm (OH emissions). These results indicate that OH radicals are generated by electron‐driven processes in water vapor present in all bubbles. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A single platform image cytometer for resource‐poor settings to monitor disease progression in HIV infection
Authors: Ymeti Aurel , Li Xiao , Lunter Björn , Breukers Christian , Tibbe Arjan G. J. , Terstappen Leon W. M. M. , Greve Jan
Published: January 2007

Background

For resource‐poor countries, affordable methods are required for enumeration of CD4+ T lymphocytes of HIV‐positive patients. For infants, additional determination of CD4/CD8 ratio is needed.

Methods

We determine the CD4+ and CD8+ T lymphocytes as the CD3+CD4+ and CD3+CD8+ population of blood cells. Target cells are CD3‐immunomagnetically separated from the whole blood, and CD4‐Phycoerythrin and CD8‐PerCP immunofluorescently labeled. A point‐of‐care single platform image cytometer was developed to enumerate the target CD3+CD4+ and CD3+CD8+ populations. It has light‐emitting diodes illumination, is fully computer‐controlled, operates from a 12 V battery, and was designed to be cheap and easy‐to‐handle. Target cells are imaged on a CCD camera and enumerated by an image analysis algorithm. The cytometer outputs the absolute number of CD4+ and CD8+ T lymphocytes/μl and CD4/CD8 ratio.

Results

The quality of the cell images obtained with the cytometer is sufficient for a reliable enumeration of target cells. The image cytometer achieves an accuracy of better than 10% in the range of 50–1700 cells/μl. Analysis of blood samples from HIV patients yields a good agreement with the TruCount method for CD4 and CD8 count and CD4/CD8 ratio.

Conclusions

The image cytometer is affordable (component costs $3,000), compact (25 × 25 × 20 cm3), and uses disposable test materials, making it a good candidate to monitor progression of immunodeficiency disease in resource‐poor settings. © 2007 International Society for Analytical Cytology.
Expression of inhibitory receptor ILT3 on neoplastic B cells is associated with lymphoid tissue involvement in chronic lymphocytic leukemia
Authors: Colovai Adriana I. , Tsao Lawrence , Wang Su , Lin Hana , Wang Chuan , Seki Tetsunori , Fisher Julie G. , Menes Manuel , Bhagat Govind , Alobeid Bachir , Suciu‐Foca Nicole
Published: February 2007

T cell responses against leukemia‐associated antigens have been reported in chronic lymphocytic leukemia (CLL). However, the relentless accumulation of CLL B cells in some patients indicates that anti‐tumor immune responses are inefficient. Inhibitory receptors from the Ig‐like transcript (ILT) family, such as ILT3 and ILT4, are crucial to the tolerogenic activity of antigen presenting cells. In this study, we examined the expression of ILT3 on CD5+ B cells obtained from 47 patients with CLL. Using flow cytometry and RT‐PCR, we found that B CLL cells from 23 of 47 patients expressed ILT3 protein and mature ILT3 mRNA. ILT3 protein and mRNA were not found in normal B cells obtained from donors without CLL. Expression of ILT4 in normal and B CLL cells showed a pattern similar to ILT3. The frequency of ILT3 positive CLL B cells was higher in patients with lymphoid tissue involvement, suggesting that ILT3 may have prognostic value in CLL. Our findings indicate that expression of ILT3 and ILT4 on CLL B cells represents a phenotypic abnormality that may play a role in tolerization of tumor‐specific T cells. © 2007 Clinical Cytometry Society
Effects of high‐dose vitamin E supplementation on oxidative stress and microalbuminuria in young adult patients with childhood onset type 1 diabetes mellitus
Authors: Giannini C. , Lombardo F. , Currò F. , Pomilio M. , Bucciarelli T. , Chiarelli F. , Mohn A.
Published: February 2007

Introduction

The aim of this study was to evaluate the effects of high‐dose vitamin E supplementation (1200 mg/day) on reducing both microalbuminuria (MA) and oxidative stress in patients with type 1 diabetes mellitus (T1DM) and persistent MA.

Methods

We performed a 12‐month, randomized, placebo‐controlled, double‐blind cross‐over trial in ten Caucasian young adults (7m/3f; mean age 18.87 ± 2.91 years) with T1DM and persistent MA.

At baseline and at end of the treatment period, determination of albumin excretion rate (AER) and HbA1c and evaluation of the oxidant/antioxidant status were performed.

Results

At the beginning of the study, AER and HbA1c were not significantly different between the vitamin E and placebo group. No differences in terms of oxidant and antioxidant status were found between the two groups. This was associated with no significantly different urinary VEGF and TGF‐β levels. After 6 months, no significant differences in AER were observed between the two groups (p = 0.59). However, plasma and LDL‐vitamin E content were significantly higher in the vitamin E group compared to the placebo group (p = 0.0001 and p = 0.004, respectively). This was associated with a significantly longer lag phase (p = 0.002) and lower MDA (p = 0.049). However, no statistically significant differences were detected in terms of VEGF and TGF‐β urinary levels.

Conclusion

These data demonstrate that high‐dose vitamin E supplementation reduces markers of oxidative stress and improves antioxidant defence in young patients with T1DM. However, although it positively affects the oxidant/antioxidant status, vitamin E supplementation does not reduce AER in patients with T1DM and persistent MA. Copyright © 2007 John Wiley & Sons, Ltd.
Ubiquitous and uniform in vivo fluorescence in ROSA26‐EGFP BAC transgenic mice
Authors: Giel‐Moloney Maryann , Krause Daniela S. , Chen Gang , Van Etten Richard A. , Leiter Andrew B.
Published: February 2007

Transplantation studies and cell lineage analyses require the ability to explicitly distinguish morphologically identical cells that have an identifiable marker indicating their origin in vivo. Several reporter mouse strains have been generated for such studies, but pancellular detection of the marker in all tissues has not been achieved. In this report, we describe the generation of transgenic mice that express enhanced green fluorescent protein (EGFP) under control of a 187 kb bacterial artificial chromosome (BAC) containing the murine ROSA26 locus, and show several advantages over existing EGFP reporter lines. It is demonstrated that EGFP is ubiquitously and reproducibly expressed from the murine BAC transgene in all organs and tissues analyzed, including the hematolymphoid compartment. Using this new reporter strain in hematopoietic cell transplantation studies, it is demonstrated that leukocytes in recipients maintain uniform transgene expression and are easily distinguished by flow cytometric analysis of live cells. The results suggest that the ROSA26 BAC is an efficient strategy for expressing complex transgene cassettes in vivo. genesis 45:83–89, 2007. Published 2007 Wiley‐Liss, Inc.
Automated ultrasound‐assisted method for the determination of the oxidative stability of virgin olive oil
Authors: Platero‐López José , García‐Mesa José A.
Published: January 2007

A fast and automated method is proposed for determining the oxidative stability of virgin olive oil by using ultrasound. The ultrasound microprobe (3 mm in diameter) was directly immersed into the olive oil sample contained in a test tube. The most influential variables in the oxidation process, namely pulse amplitude, duty cycle, irradiation time, and sample amount, were optimized. The oil absorbance at 270 nm was continuously monitored by oil recirculation through a 0.1‐mm path length flow cell connected to a fiber optic microspectrometer. This short path length allowed the direct monitoring of absorbance without needing any sample dilution. The ultrasound energy was applied during 35 min, and the resulting increase in absorbance was continuously monitored. The difference between the final and the initial absorbance at 270 nm of a set of virgin olive oil samples was closely correlated with their oxidative stability calculated by the Rancimat method (R2 = 0.9915). The resulting equation enabled the prediction of the oxidative stability of virgin olive oil in a short period of time (35 min), by using a simple, inexpensive, automatic and easy‐to‐use system.
Electrochemical Synthesis and Characterization of 1,2‐Naphthaquinone‐4‐Sulfonic Acid Doped Polypyrrole
Authors: Akinyeye Richard Odunayo , Michira Immaculate , Sekota Mantoa , Ahmed Amir Al , Tito Duarte , Baker Priscilla Gloria Lorraine , Brett Christopher Michael Ashton , Kalaji Maher , Iwuoha Emmanuel
Published: February 2007

Polypyrrole thin film microelectrodes prepared from an aqueous solution of the sodium salt of 1, 2‐napthaquinone‐4‐sulfonic acid and pyrrole in hydrochloric acid as the supporting electrolyte was characterized electrochemically for the first time and found to exhibit good electronic and spectroscopic properties. Voltammetric investigations showed that the polymer exhibited quasireversible kinetics in a potential window of −400 mV to 700 mV, with a formal potential of 322 mV vs. Ag/AgCl. The diffusion coefficient was calculated to be 1.02×10−6 cm2 s−1 for a thin film with a surface concentration of 1.83×10−7 mol cm−2 having a rate constant of 2.20×10−3 cm s−1 at 5 mV s−1. Electrochemical impedance spectroscopy provided quantitative information about the conductivity changes within the modified polymer and support for the quasireversible kinetics suggested by voltammetry. The changes in electrical properties of the polymer during electrochemical p‐doping and n‐doping were quantified by equivalent electrical circuit fitting and assisted in the identification of the suggested kinetic mechanism. SNIFTIRS confirmed the incorporation of the surfactant into the polypyrrole film and for the first time structural changes within the polymer were observed that could be related to the observed electrochemistry of the polymer.
Microbial Characteristics through Drinking Water Aquifer Sand Material
Authors: Ibekwe A. M. , Lyon S. R.
Published: February 2007

Public health concerns about pathogens present in animal manure are emerging constraints to water supplies in many areas of the world. The objective of this study was to examine the microbial community composition in aquifer material impacted by contaminants from different sources. Total microbial community profiles were compared by using eubacterial primers to amplify 16S rRNA genes from total bacterial DNA and RNA. PCR and reverse transcriptase (RT) PCR were used to amplify 16S ribosomal RNA, and the products were subjected to denaturing gradient gel electrophoresis (DGGE). DGGE analysis of RT‐PCR products detected a subset of bands visible in the DNA‐based analysis, indicating that some dominantly detected bacterial populations did not have high levels of metabolic activity. The sequences detected by the RT‐PCR approach were, however, derived from a wide taxonomic range, suggesting that the activity in the aquifer sand material was not determined at broad taxonomic levels but rather was a strain‐ or species‐specific phenomenon. Comparative analysis of DGGE profiles grouped all DNA‐derived aquifer samples together in a cluster. At the end of the experimental period, the aquifer material entered a stable population state, which was characterized by a greater diversity of DNA‐based fingerprints compared to viable bacteria. Our data showed that the active members of the community are a sub‐population of that community that performs certain biological functions during water filtration through aquifer material. Therefore, recharging surface water through aquifer sand material may produce a microbial population quite different from the input source due to the availability of nutrients for bacterial growth.
Flood‐related channel change in an arid‐region river
Authors: Graf William L.
Published: February 2007

A review of 112 years of change in the channel of the Salt River, central Arizona, U.S.A., shows that this arid‐region river has a main‐flow channel that has migrated laterally up to 1.6 km (1 mi) in response to floor events. Maps showing locational probabilities indicate that along the channel zones of relative locational stability alternate with zones of relative instability at a 3.2 km (2 mi) interval. Construction of upstream reservoirs has reduced sediment input into the main river but has not controlled floods. The channel width has not changed except for moderate fluctuations around mean values; the main‐flow channel has incised approximately 6 m (20 ft) over most of the 48 km (30 mi) study reach during six recent floods. Gradient has remained unchanged. During floods bed material was mobilized to a depth below the original bed level that was greater than the height of the water surface above the original bed. Calculations based on tractive force indicate a threshold discharge of instability that is equal to the flow with a five‐year return interval. The river exhibits remarkable stability with respect to gradient and sinuosity, irrespective of water and sediment discharges, but horizontal channel location exhibited selective instability. Over the record period of more than a century, the channel appears not to have been in equilibrium considering geometry, discharge, and sediment.
Spatial variation in solutional denudation and soil moisture over a hillslope hollow
Authors: Crabtree R. W. , Burt T. P.
Published: February 2007

A spatial pattern of relative solutional denudation is described for a hillslope hollow and adjacent spurs at Bicknoller Combe, Somerset. The pattern was obtained from a network of micro‐weight loss rock tablets emplaced in the soil. The results show that the hollow is the main locus of solutional denudation. The soil moisture distribution over the hollow indicates that it is a transmission zone for acid soil water percolating from the adjacent spurs to the saturated wedge at the base of the hollow. The wetter acid soils in the hollow are responsible for the relatively higher solutional denudation taking place in the hollow.
Preliminary estimates of intertidal limestone erosion, one tree island, southern great barrier reef, australia
Authors: Trudgill Stephen T.
Published: February 2007

Estimations of surface lowering of 0.2‐3.8 mm a−1 were gained from measurements of pedestal heights under sedentary organisms. The role of erosion by chitons, estimated at 0.2‐2.9 mm a−1 for home scars and 0.2‐0.7 mm a−1 for grazing, and other bioerosive organisms, is briefly discussed.
A note on the amount of wave energy transmitted over nearshore sand bars
Authors: Carter R. W. G. , Balsillie J. H.
Published: February 2007

The wave energy loss as waves break on nearshore bars is an important geomorphological process as it controls the stability of the adjacent beaches and dunes. The effect is particularly important during storms as it serves to guard against severe shoreline erosion.

Field measurements from Florida and Ireland of waves crossing both single and multiple bar bedforms, indicate that where bar‐breaking occurs, between 78 and 99 per cent of wave energy may be dissipated from individual waves. However, a further 20 per cent energy may reach the shore if wave frequencies increase during the reformation process. This latter effect was not noted at the multiple bar site where spilling mode breakers dominate. The level of energy dissipation is related to the time taken to cross that section of the submerged bar below the critical depth, d < 1.28H. In the field this may be approximated by the ratio of wave speed to the width of the bar breaker zone.
Periodic heat conduction in a non‐uniform soil
Authors: Wiltshire R. J.
Published: February 2007

The one dimensional heat conduction equation is applied to a non‐uniform soil in which harmonic boundary conditions are specified. The analytic solutions are derived for practical use and satisfy a law that the thermal diffusivity is proportional to the square of the speed of the temperature wave. Depending on the nature of this speed the solutions may be categorized as circular, parabolic, hyperbolic, or exponential. A practical example is given in which the damping depth and thermal capacity of the soil both vary with depth. It shows that there may be considerable differences between uniform and nonuniform soils as far as temperature is concerned. A case of a slowly varying soil layer is also examined and is compared with the constant soil solution.
Slope process change and colluvium deposition in Swaziland: An SEM analysis
Authors: Goudie Andrew , Bull Peter A.
Published: February 2007

Electron microscope analysis of sixty samples taken from six colluvium sites in Swaziland has shown that the quartz grains exhibit marked edge abrasion in the uppermost beds of exposures. This edge abrasion is lacking in the lower beds in all sections examined and indicates slope process change during colluvium deposition. A model of slope evolution is provided, in which slope erosion progressively brings about more channelling and causes greater surface roughness because of the exhumation of more core stones and differentially weathered rock. This roughness causes increased edge abrasion.
Eolian dust deposition on the Giara di Gesturi basalt plateau, Sardinia
Authors: Sevink J. , Kummer E. A.
Published: February 2007

Mineralogical study of samples from depression fills on an isolated basalt plateau in Central Sardinia showed that, although the basalt is free of quartz and mica, fair amounts of these minerals occur in the finer fractions. Results from X‐ray analyses of silt fractions and morphoscopical analyses of sand fractions indicate that the bulk of the quartz and mica is of eolian origin.

The eolian quartz is predominantly of medium and coarse silt size and, in the upper 10 cm of the depression fills, constitutes about 20 per cent of the soil mass (approx. 20 kg/m2). Eolian mica is present in smaller amounts and is of medium silt or smaller size.

The provenance of the eolian material could not be established with certainty, although a local origin can be excluded.
Hydraulics of runoff and loess loam deposition
Authors: De Ploey J.
Published: February 2007

On many more or less loamy soils, rill erosion is reported to start on slopes that are equal to or steeper than 2–3°; critical Froude numbers for the start of rill wash on these slopes vary between 2·0 and 3·0. This explains why colluvial deposition often occurs on slopes below 2–3°, when water spreads out at the downslope extremities of the rills.

The critical hydraulic conditions for loess loam deposition were tested in the laboratory for slopes of 0·5° and 2°, applying unit‐discharges (q) up to 10 cm2/s. It appeared from these experiments that for afterflow, without raindrop impact, deposition starts for critical load concentrations (ccr) varying between several g/1 and about 60 g/l. Under rain ccr amounts to a minimum value of 100–125 g/l and it increases when the runoff film becomes thinner. Nevertheless, deposition in pluvial runoff is also possible, as was the case during the Weichselian, according to data from quarries in Belgium and in The Netherlands.

A modified Kalinske equation is proposed for ccr prediction, with the introduction of a typical empirical coefficient Cr and considering such factors as shear stress and mean particle size. Massive sedimentation may occur when it stops raining and afterflow starts, since ccr values are then much lower. It is shown from the Shields' diagram that loamy suspensions are more sensitive to sedimentation than sands in clear water.
Structures caused by repeated freezing and thawing in various loamy sediments: A comparison of active, fossil and experimental data
Authors: Van Vliet‐Lanoë Brigitte , Coutard Jean‐Pierre , Pissart Albert
Published: February 2007

In this paper, the authors present the results of both macroscopic and microscopic investigations on structure development created by repeated ice lensing in various loamy experiments. Experimental data are compared with observations performed on active forms in High Arctic and Alpine Mountain environments. Those observations are also compared with phenomena observed in fossil periglacial formations of Western Europe.

Platy and short prismatic structure formation is bonded to the hydraulic and thermal conditions during ice segregation. When a long series of alternating freezing and thawing affects platy structures, the fabric evolves, also being influenced by slope and drainage conditions: cryoturbations, frostcreep, and gelifluction can appear. They are characterized by specific microfabrics which are better developed with an increasing number of cycles: this is clear in experiments where hydraulic and thermal parameters are better controlled.

Vesicles are also a prominent characteristic of the surface horizon in experiments and arctic soils. The genesis of vesicles is discussed on the basis of new observations and is related to the mechanical collapse of frost‐created aggregates under the mechanical work of soil air escape during soil saturation by water at thaw.
Determination of dissolved organic matter in streamwater using visible spectrophotometry
Authors: Grieve Ian C.
Published: February 2007

Absorbance at 360 nm was measured on 44 filtered streamwater samples of different dissolved organic matter (DOM) contents. A regression equation of DOM on absorbance predicted DOM with a standard error of estimate of 1.26 mgl−1, Use of a published equation relating dissolved organic carbon (DOC) to absorbance gave DOC values for the samples which were consistent with measured DOM. The method offers considerable potential for rapid quantification of dissolved organic matter concentrations in streamwater.
Sediment yield estimated from reservoir siltation in the Ochil hills, Scotland
Authors: McManus John , Duck Robert W.
Published: February 2007

Measurements made on the floors of the temporarily‐drained Glenfarg and Glenquey Reservoirs indicate that sediments with wet volumes of 63.94 × 103 m3 and 12.64 × 103 m3 were deposited in 56 and 73 years respectively. These figures represent 2.5 per cent and 1.1 per cent losses of original storage capacity. When corrected for water, organic, and diatom skeleton contents, and reservoir trap efficiency inorganic sediment yields of at least 31.3 tonnes km−2 yr−1 and of 9.0 tonnes km−2 yr−1 are suggested. The difference is probably related to contrasts of land use.
Attainable standards of accuracy in the retrodiction of palaeodischarge from channel dimensions
Authors: Dury G. H.
Published: February 2007

The most easily measurable palaeodimension on underfit streams is the wavelength of valley meanders, whether on manifest or on Osage‐type underfits. Checks that use data for existing, streams, however, suggest that retrodiction from wavelength is likely to be less accurate than retrodiction from width, while this in turn is less accurate than retrodiction from cross‐sectional area, or from some combination of cross‐sectional area and slope. Against this, former width and cross‐sectional area can be difficult to determine with any precision. Even where dimensions are known, calculation of discharge from these alone seems likely to range between some 75 and 130 per cent of actual values at the 50 per cent confidence limits, and between some 45 and 225 per cent at the 95 per cent limits. Variation in the form ratio appears to make no contribution to the difference between observed and expected velocities through the cross‐section. Unless former roughness can be reconstructed, by some other means than appeal to the form ratio, or unless something can be done with sediment transport, the retrodiction of palaeodischarge appears likely to remain subject to much uncertainty.
Definition of subfossil meandering palaeochannels
Authors: Rotnicki Karol , Borówka Ryszard K.
Published: February 2007

The determination of the bottom of a subfossil meandering palaeochannel is important for investigations of the palaeohydrology of valley bottoms, and crucial for the quantitative estimation of past river discharges. The authors present a procedure on the basis of which the bottom of a palaeochannel can be precisely determined. It is based on an analysis of the stratigraphic variability of such features of deposits as: mean diameter, standard deviation of the grain‐size composition, the percentage of sand, and ignition loss.
A factor analytic approach to the identification of geomorphic processes from soil particle size characteristics
Authors: East Thomas J.
Published: February 2007

Q‐mode factor analysis of soil particle size data is used to identify the three dominant geomorphic processes responsible for the spatial variability of particle size in a catchment on the basaltic Darling Downs landsurface. Three factors are shown to account for 95 per cent of the textural variability of a suite of transported and sedentary materials. The spatial characteristics of groups of samples associated with the three factors suggests that the three factors are associated with suspended sediment transport and deposition, weathering, and bedload transport and deposition respectively. These interpretations are supported by the detailed graphical analysis of the cumulative particle size curves. The spatially variable influence of the three factors and related processes is given by their respective factor loadings which are mappable for the surface layer materials.
Genesis of late pleistocene cross‐valley moraine ridges, South—Central Ulster, Northern Ireland
Authors: Dardis George F.
Published: February 2007

Four genetic varieties of ice‐marginal cross‐valley moraine ridge have been identified in south‐central Ulster, Northern Ireland. Type I ridges are flat topped, composed of stratified, water‐lain sediments and formed by coalescence of a series of supraaquatic deltas. Type II ridges are sharp crested, composed of stratified, water‐lain sediments and formed by coalescence of a series of subaquatic deltas. Type III ridges show mixed morphological and sedimentological characteristics of type I and II ridges. Type IV ridges are sharp crested or hummocky, composed of poorly‐sorted and poorly‐stratified water‐lain sediments and formed by coalescence of a series of subaquatic sediment gravity flow cones. Field evidence indicates that cross‐valley moraine ridges in south‐central Ulster were deposited in proglacial lacustrine environments. Ridge type depended principally on (1) the nature of the proglacial bedrock slope; (2) the manner in which meltwater entered the proglacial zone; and (3) ice‐sheet behaviour during deglaciation, particularly within the ice‐sheet terminus zone.
Corroded cobbles in Southern Death Valley: Their relationship to honeycomb weathering and lake shorelines
Authors: Butler Paul R. , Mount Jeffrey F.
Published: February 2007

In southern Death Valley, pits similar in morphology to honeycomb weathering (herein referred to as corrosion pits) occur on the surfaces of cobbles that are associated with wave‐produced benches. The pitted cobbles include a variety of igneous, metamorphic, and siliciclastic rocks; corrosion pits are rare to absent in limestones or dolomites. Pit morphology is controlled by cobble lithology. In massive rocks the pits are arcuate, elongate, and gently tapering; corrosion of laminated or foliated rocks has produced irregular, more jagged pits. The presence of desert varnish has strongly inhibited the corrosion process.

The corroded cobbles are inferred to reflect both chemical and physical weathering of rocks along Pleistocene lacustrine strandlines. Corrosion took place through salt‐weathering and/or heat‐moisture expansion processes and through chemical dissolution of selected minerals as a result of splash‐zone wetting and drying. The ancient lake waters may have had high pH and high total dissolved solids contents. The recognition of corroded cobbles may be important in the reconstruction of the position of ancient shorelines for certain types of alkaline lakes and in the reconstruction of their ancient chemistries.
Semi‐variograms for modelling the spatial pattern of landform and soil properties
Authors: Oliver Margaret A. , Webster R.
Published: February 2007

Many geomorphic properties can be treated as spatially‐dependent random variables. Some are second‐order stationary, others appear to vary without bound. In these circumstances their variation is best described by the semi‐variogram. In most instances the semi‐variogram can be modelled by a simple mathematical function, which itself is bounded for a stationary variable and unbounded otherwise. The function must be conditional negative semi‐definite to be permissible. More complex variation can be represented by combining two or more permissible models.

Sample semi‐variograms of several landform and soil properties illustrate the common types of semi‐variogram. Their form and parameters are interpreted in physical terms.