bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of field‐enhanced and pressure‐assisted field‐enhanced sample injection techniques for the analysis of water‐soluble vitamins using CZE
Authors: Liu Qingqing , Liu Yaling , Guan Yu , Jia Li
Published: February 2009

A new online concentration method, namely pressure‐assisted field‐enhanced sample injection (PA‐FESI), was developed and compared with FESI for the analysis of water‐soluble vitamins by CZE with UV detection. In PA‐FESI, negative voltage and positive pressure were simultaneously applied to initialize PA‐FESI. PA‐FESI uses the hydrodynamic flow generated by the positive pressure to counterbalance the reverse EOF in the capillary column during electrokinetic sample injection, which allowed a longer injection time than usual FESI mode without compromising the separation efficiency. Using the PA‐FESI method, the LODs of the vitamins were at ng/mL level based on the S/N of 3 and the RSDs of migration time and peak area for each vitamin (1 μg/mL) were less than 5.1%. The developed method was applied to the analysis of water‐soluble vitamins in corns.
A boundary value problem for the spherically symmetric motion of a pressureless gas with a temperature‐dependent viscosity
Authors: Ducomet Bernard , Nečasová Šárka
Published: February 2009

We consider an initial‐boundary value problem for the equations of spherically symmetric motion of a pressureless gas with temperature‐dependent viscosity µ(θ) and conductivity κ(θ). We prove that this problem admits a unique weak solution, assuming Belov's functional relation between µ(θ) and κ(θ) and we give the behaviour of the solution for large times. Copyright © 2009 John Wiley & Sons, Ltd.
Ossified haematomas and infectious bone changes on the anterior tibia: histomorphological features as an aid for accurate diagnosis
Authors: Van der Merwe A. E. , Maat G. J. R. , Steyn M.
Published: February 2009

Examination of the histological structure of bone not only helps investigators to estimate age at death but can also aid in the diagnosis of palaeopathological lesions. The purpose of this paper is to assess whether histological features as described in the literature can confirm the macroscopic diagnoses of ossified subperiosteal haematomas associated with healed scurvy and syphilitic bone changes observed on the anterior tibiae of individuals from a 19th century mining community from Kimberley South Africa. The frequent occurrence of these two diseases amongst the deceased was well established in related hospital documents and governmental documents. A section of bone was removed from lesions on the tibiae of 14 individuals. These bone changes were macroscopically diagnosed as being indicative of either treponematosis ossified subperiosteal haematomas or non‐specific periostitis. Cross‐sections were prepared for microscopic investigation using a manual ground section technique. Ossified haematomas were histologically identified in seven individuals. These sections were characterised by normal cortical bone an intact original periosteal surface and newly formed radiating trabecular bone apposing it. Three phases of ossified subperiosteal haematoma formation and remodelling could be distinguished. Infectious bone changes most likely associated with treponematosis were observed in one individual. These were characterised by lysis and numerous resorption holes/channels. No clear distinction could be made between the internal spongy cortical or newly formed bone. Histological features described by some authors as characteristic of this condition could not be identified. In addition three individuals presented with microscopic features indicative of both the aforementioned bone affections and three did not show any pathological changes on microscopic level. It was concluded that although specific pathological conditions can most likely not be diagnosed purely on the basis of histomorphological observations broad distinctions could be made between lesions caused by the ossification of subperiosteal haematomas and bone changes due to infectious diseases. Copyright © 2009 John Wiley & Sons Ltd.
A dynamic game of status‐seeking with public capital and an exhaustible resource
Authors: Katayama Seiichi , Long Ngo Van
Published: February 2009

This paper explores the link between status‐seeking and the exploitation of a common property exhaustible resource. The extracted resource is an input in the production of a final good. The other input is man‐made capital, which is a second state variable. Extraction requires efforts. Economic agents derive utility not only from absolute consumption, but also from relative consumption, because the latter is a signal of relative status. We consider a differential game involving n infinitely lived agents. We compare the Markov‐perfect Nash equilibrium of this game with the outcome under cooperation. We find that the degree of status‐consciousness has important impact on the Markov‐perfect Nash equilibrium. A higher degree of status‐consciousness leads to greater excessive consumption, and lower capital accumulation. If extraction is costless, status‐consciousness has no impact on the extraction/resource‐stock ratio. However, with costly extraction, higher status‐consciousness reduces this ratio. Copyright © 2009 John Wiley & Sons, Ltd.
The effect of Rhesus status on first‐trimester pregnancy screening markers free β human chorionic gonadotropin, pregnancy‐associated plasma protein‐A and nuchal translucency
Authors: Cowans Nicholas J. , Stamatopoulou Anastasia , Spencer Kevin
Published: February 2009

Objective

To examine whether maternal Rhesus status has any effect on the levels of first‐trimester markers free beta‐human chorionic gonadotropin (β‐hCG), pregnancy‐associated plasma protein‐A (PAPP‐A) and nuchal translucency (NT).

Methods

First‐trimester free‐β‐hCG and PAPP‐A levels from pregnant women attending three hospitals in Kent were converted into MoMs and corrected for maternal weight, ethnicity, and smoking status. Maternal Rhesus status data were merged with screening data and free‐β‐hCG and PAPP‐A medians multiples of medians (MoMs) and NT from the Rhesus positive and Rhesus negative group were compared.

Results

Totally, 15 045 normal, singleton pregnancies were retrieved with full records. Altogether, 16.0% of the population were Rhesus negative. There was no difference between the medians MoMs of both free‐β‐hCG nor PAPP‐A nor NT in the two Rhesus status groups (p > 0.05). Demographic analysis on the distribution of Rhesus status in different ethnic origins showed that Caucasians have lower percentages of RhD‐positive antigen compared to Asians and Afro–Caribbeans.

Conclusion

Maternal Rhesus status does not influence the levels of free‐β‐hCG and PAPP‐A in the first trimester of pregnancy in this almost exclusively Caucasian population studied; therefore correction for maternal Rhesus status is not suggested. Copyright © 2009 John Wiley & Sons, Ltd.
Structural changes on citronellol induced by gamma radiation
Authors: Rodríguez‐Linares Diana , Codorniu‐Hernández Edelsys , Aguilera‐Corrales Yuri , Rapado‐Paneque Manuel , Quert‐Alvarez Rolando , Ferro Noel
Published: February 2009

Structural changes in pure citronellol after exposure to different doses of gamma radiation were elucidated by spectroscopic techniques and molecular modelling methods. The citronellol samples were irradiated in an MPX‐γ30 installation (60Co, E = 1.25 MeV), absorbing in a dose range from 1.45 to 10.02 kGy. Citronellal and hydroxycitronellal compounds were detected in the irradiated samples. Some mechanisms of radiolytic transformations for citronellol were proposed and modelled at semiempirical quantum chemical level. These results provide the basis for the possible development of new synthetic pathways for close structurally related compounds, based on the use of gamma irradiation. Copyright © 2009 John Wiley & Sons, Ltd.
Rate limiting electrophilic attack in nitrosation of aminoguanidine
Authors: Fernández I. , Hervés P. , Parajó M.
Published: February 2009

Nitrosation reaction of aminoguanidine (AG) has been studied. The nitrosation rate is first‐order with respect to both the AG and acid concentration. The absence of general base catalysis, the existence of catalysis by nucleophilic anions (X−and SCN−) and the observed inverse deuterium isotope effect lead us to propose a mechanism for AG nitrosation similar to that which operates in the case of amines, in which the electrophilic attack of the nitrosating agents is the rate determining step. From this mechanism, we were able to obtain the values of the rate constants for the nitrosation process. We have found that unlike the other amines, the protonated form of AG is the reactive species. This situation becomes possible for AG because protonation of guanidines occurs mostly on the iminic nitrogen, and this may be the reason for the lower reactivity of this amine. Copyright © 2009 John Wiley & Sons, Ltd.
Structure and function of natural and synthetic signalling molecules in parasitic weed germination
Authors: Zwanenburg Binne , Mwakaboko Alinanuswe S , Reizelman Anat , Anilkumar Gopinathan , Sethumadhavan Divakaramenon
Published: February 2009

The structures of naturally occurring germination stimulants for seeds of the parasitic weeds Striga spp. and Orobanche spp. are described. The bioactiphore in this strigolactone family of stimulants is deduced from a structure–activity relationship and shown to reside in the CD part of the stimulant molecule. A molecular mechanism for the initial stages of seed germination is proposed. The influence of stereochemistry on the stimulant activity is significant. Combining this molecular information leads to a model for the design of synthetic strigolactones. Nijmegen‐1 is a typical example of a highly active, newly designed synthetic stimulant. The occurrence of natural stimulants not belonging to the strigolactone family, such as cotylenin and parthenolide, is briefly described. The biosynthesis of natural strigolactones from β‐carotene is analysed in terms of isolated and predicted stimulants. This scheme will be helpful in the search for new strigolactones from root exudates. Protein fishing experiments to isolate and characterise the receptor protein using biotin‐labelled GR 24 are described. A receptor protein of 60 kD was identified by this method. Nijmegen‐1 has been tested as a suicidal germination agent in field trials on tobacco infested by Orobanche ramosa L. The preliminary results are highly rewarding. Finally, some future challenges in synthesis are described. These include synthesising new natural and synthetic stimulants and establishing the molecular connection between strigolactones as germination stimulants, as the branching factor for arbuscular mycorrhizal fungi and as an inhibitor of shoot branching. Copyright © 2009 Society of Chemical Industry
A major QTL for resistance of rice to the parasitic plant Striga hermonthica is not dependent on genetic background
Authors: Swarbrick Philip J , Scholes Julie D , Press Malcolm C , Slate Jon
Published: February 2009

BACKGROUND: The use of Striga‐resistant germplasm is likely to be a cost‐effective control strategy for preventing loss of yield owing to Striga. Previously, the authors identified quantitative trait loci (QTL) for resistance in rice to Striga hermonthica (Del.) Benth. in backcross inbred lines (BILs) derived from a cross between two cultivars Nipponbare and Kasalath. It is essential to validate QTL in different environments and/or genetic backgrounds to develop molecular markers linked to resistance QTL for use in marker‐assisted selection (MAS) programmes. This study aimed to establish whether a large‐effect Kasalath‐derived resistance QTL allele on chromosome 4 of rice also conferred resistance in a different mapping population derived from a cross between Koshihikari and Kasalath, and to identify any further Striga resistance QTL.

RESULTS: Three Striga resistance QTL were detected in Koshihikari–Kasalath BILs, two of which were derived from the Kasalath allele and one from the Koshihkari allele. The largest QTL (Kasalath allele) explained 16% of the variation in the mapping population and was located on chromosome 4. Comparison between these data and those of the authors' previous analysis revealed that the confidence intervals of the chromosome‐4 QTL in the Nipponbare–Kasalath cross and the Kasalath–Koshihikari cross overlapped between 6.5 Mbp and 8 Mbp on the physical rice genome assembly.

CONCLUSION: This study has both verified and narrowed down the position of a Striga resistance QTL of major effect, and demonstrated that it may be a tractable target for MAS. Copyright © 2009 Society of Chemical Industry
Strigolactones: structures and biological activities
Authors: Yoneyama Koichi , Xie Xiaonan , Yoneyama Kaori , Takeuchi Yasutomo
Published: February 2009

Strigolactones released from plant roots induce seed germination of root parasitic weeds, witchweeds (Striga spp.) and broomrapes (Orobanche spp.), and hyphal branching of symbiotic arbuscular mycorrhizal (AM) fungi. In addition to these functions in the rhizosphere, strigolactones have recently been shown to be a novel class of plant hormones regulating shoot outgrowth. The natural strigolactones identified so far have the common C–D ring moiety, which is thought to be the essential structure for exhibiting biological activity. The introduction of substitutions on the A–B ring moiety of 5‐deoxystrigol, the basic strigolactone, affords various strigolactones, e.g. hydroxylation on C‐4, C‐5 and C‐9 leads to orobanchol, strigol and sorgomol respectively. Then, acetylation and probably other derivatisations of these hydroxy‐strigolactones would occur. Although the C‐2′‐(R) stereochemistry was thought to be an important structural feature for potent germination stimulation activity, 2′‐epi‐strigolactones were found in root exudates of tobacco, rice, pea and other plant species, indicating that at least some plants produce both epimers. Copyright © 2009 Society of Chemical Industry
Formation of CdSxTe1–x at the p‐n junction of CdS‐CdTe solar cells
Authors: Hädrich Mathias , Kraft Christian , Metzner Heinrich , Reislöhner Udo , Löffler Christiane , Witthuhn Wolfgang
Published: February 2009

The formation of ternary CdSxTe1–x alloys during CdTe solar cell production is quantitatively investigated using optical and quantum efficiency measurements. Both the diffusion of sulphur into the CdTe and of tellurium into the CdS film are analysed in the context of film thicknesses and the activation step used in CdTe solar cell processing. We present a method of determining the tellurium content in the CdS layer from EQE measurements. The tellurium content is limited to small values and depends on the CdS thickness. A CdSxTe1–x phase of several 100 nm thickness is generated in the CdTe film during the activation step. This phase changes the optical bandgap in the depletion region and gains importance in cells with thin absorbers. The comparison of solar cells with and without CdS layer illustrates the crucial role of the CdS buffer layer for the p‐n junction. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐temperature electrical properties of CdTe:Bi single crystals
Authors: Fochuk P. , Obedzynska Yu. , Armani N. , Zakharuk Z. , Yuriychuk I. , Kopach O. , Panchuk O.
Published: February 2009

At first the experimental results of detailed Hall effect measurements at high‐temperature defect equilibrium under Cd/Te vapor pressure in CdTe single crystals were obtained. They indicate that at these conditions Bi forms in CdTe crystals mainly BiCd donor centers. The analysis of the free electron density temperature dependencies allows to conclude that up to 800 K the electrons of dopant atoms define the sample's electrical properties. The native donor point defects begin to influence the electro‐neutrality condition above this temperature. The research of high‐temperature electrical properties of Bi‐doped CdTe samples shows that the real electrical active Bi content in the investigated crystals is ∼1017 at/cm3. The electron density dependencies vs PCd, modeled at constant temperatures (500‐900°C), in the assumption of deep Bi donor (EV+0.71 eV) are in good agreement with experiment. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystal structures, thermal expansion and phase transitions of mixed Pr1–xLaxAlO3 perovskites
Authors: Basyuk Tetyana , Vasylechko Leonid , Syvorotka Igor , Schmidt Ulrike , Trots Dmytro , Niewa Rainer
Published: February 2009

The crystal structures, thermal expansion and phase transitions of mixed Pr1–x Lax AlO3 perovskites have been examined by using an in situ high resolution X‐ray powder diffraction technique applying synchrotron radiation in a wide temperature range of 12–1173 K. At room temperature all samples in the PrAlO3–LaAlO3 pseudo‐binary system adopt the rhombohedral perovskite‐like structure. At elevated temperatures, all Pr1−x Lax AlO3 compositions undergo continuous phase transitions from rhombohedral to cubic structures. The sequence of the low‐temperature (LT) phase transformations R $\bar 3$ c ↔Imma ↔C2/m has been observed in Pr1–x Lax AlO3 samples. Temperatures of HT and LT phase transitions in Pr1–x Lax AlO3 decrease with decreasing Pr content. Crystal structure parameters for all compositions Pr1–x Lax AlO3 have been determined. Based on in situ powder diffraction and DTA/DSC data, the phase diagram of the PrAlO3–LaAlO3 pseudo‐binary system has been constructed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of lignans in Schisandra chinensis and rat plasma by high‐performance liquid chromatography diode‐array detection, time‐of‐flight mass spectrometry and quadrupole ion trap mass spectrometry
Authors: Lou Ziyang , Zhang Hai , Gong Chungui , Zhu Zhenyu , Zhao Liang , Xu Yuanjie , Wang Bin , Zhang Guoqing
Published: February 2009

High‐performance liquid chromatography/diode‐array detection (HPLC/DAD), time‐of‐flight mass spectrometry (HPLC/TOFMS) and quadrupole ion trap mass spectrometry (HPLC/QIT‐MS) were used for separation, identification and structural analysis of lignans in Schisandra chinensis and rat plasma after oral administration of the herbal extract. Six lignans in Schisandra chinensis extract were identified unambiguously by comparing the retention time, their characteristic ultraviolet (UV) absorption and accurate mass measurement. A formula database of known lignans in Schisandra chinensis was established, against which the other 15 lignans were identified effectively based on the accurate extract masses and formulae acquired by HPLC/TOFMS. In order to distinguish the isomers, multi‐stage mass spectrometry (ion trap mass spectrometry, MSn) was also used. The fragmentation behavior of the lignans in the ion trap mass spectrometer was studied by the six lignan standards, and their fragmentation rules in MSn spectra were summarized. These deduced fragmentation rules of lignans were successfully implemented in distinguishing the three groups of isomers in Schisandra chinensis by HPLC/QIT‐MS. By using the three different analytical techniques, 21 lignans in Schisandra chinensis were identified within 30 min. After oral administration of the extract, 11 lignans in rat plasma were detected and identified by comparing their retention time, characteristic UV absorption and accurate mass measurement of peaks in HPLC/TOFMS chromatograms of the herbal extract. Finally, HPLC/TOFMS fingerprints of Schisandra chinensis in vitro and rat plasma in vivo were established. It is concluded that a rapid and effective method based on three analytical techniques for identification of chemical components was established, which is useful for rapid identification of multiple components in Schisandra chinensis in vitro and in vivo. In addition, it can provide help for further pharmacology and action mechanism study of lignans in Schisandra chinensis. Copyright © 2009 John Wiley & Sons, Ltd.
Evaluation of matrix‐assisted laser desorption/ionization (MALDI) preparation techniques for surface characterization of intact Fusarium spores by MALDI linear time‐of‐flight mass spectrometry
Authors: Kemptner Jasmin , Marchetti‐Deschmann Martina , Mach Robert , Druzhinina Irina S. , Kubicek Christian P. , Allmaier Günter
Published: February 2009

Unambiguous identification of mycotoxin‐producing fungal species as Fusarium is of great relevance to agriculture and the food‐producing industry as well as in medicine. Protein profiles of intact fungal spores, such as Penicillium, Aspergillus and Trichoderma, derived from matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) were shown to provide a rapid and straightforward method for species identification and characterization. In this study, we applied this approach to five different Fusarium spp. strains which are known to affect the growth of different grain plants. To obtain a suitable MALDI matrix system and sample preparation method, thin‐layer, dried‐droplet and sandwich methods and several MALDI matrices, namely CHCA, DHB, FA, SA and THAP dissolved in various solvent mixtures (organic solvents such as ACN, MeOH, EtOH and iPrOH and for the aqueous phase water and 0.1% TFA), were evaluated in terms of mass spectrometric pattern and signal intensities. The most significant peptide/protein profiles were obtained with 10 mg ferulic acid (FA) in 1 mL ACN/0.1% TFA (7:3, v/v) used as matrix system. Mixing the spores with the matrix solution directly on the MALDI target (dried‐droplet technique) resulted in an evenly distributed spores/matrix crystal layer, yielding highly reproducible peptide/protein profiles from the spore surfaces. Numerous abundant ions throughout the investigated m/z range (m/z 1500–15 000) could be detected. Differences in the obtained mass spectral patterns allowed the differentiation of spores of various Fusarium species. Copyright © 2009 John Wiley & Sons, Ltd.
Trauma Pod: a semi‐automated telerobotic surgical system
Authors: Garcia Pablo , Rosen Jacob , Kapoor Chetan , Noakes Mark , Elbert Greg , Treat Michael , Ganous Tim , Hanson Matt , Manak Joe , Hasser Chris , Rohler David , Satava Richard
Published: February 2009

Background

The Trauma Pod (TP) vision is to develop a rapidly deployable robotic system to perform critical acute stabilization and/or surgical procedures, autonomously or in a teleoperative mode, on wounded soldiers in the battlefield who might otherwise die before treatment in a combat hospital could be provided.

Methods

In the first phase of a project pursuing this vision, a robotic TP system was developed and its capability demonstrated by performing selected surgical procedures on a patient phantom.

Results

The system demonstrates the feasibility of performing acute stabilization procedures with the patient being the only human in the surgical cell. The teleoperated surgical robot is supported by autonomous robotic arms and subsystems that carry out scrub‐nurse and circulating‐nurse functions. Tool change and supply delivery are performed automatically and at least as fast as performed manually by nurses. Tracking and counting of the supplies is performed automatically. The TP system also includes a tomographic X‐ray facility for patient diagnosis and two‐dimensional (2D) fluoroscopic data to support interventions. The vast amount of clinical protocols generated in the TP system are recorded automatically.

Conclusions

Automation and teleoperation capabilities form the basis for a more comprehensive acute diagnostic and management platform that will provide life‐saving care in environments where surgical personnel are not present. Copyright © 2009 John Wiley & Sons, Ltd.
Electroluminescent Characteristics of DBPPV–ZnO Nanocomposite Polymer Light Emitting Devices
Authors: Madhava Rao MV , Su YanKuin , Huang TsungSyun , Yeh Chen-Han , Tu Ming-Lung
Published: February 2009

We have demonstrated that fabrication and characterization of nanocomposite polymer light emitting devices with metal Zinc Oxide (ZnO) nanoparticles and 2,3-dibutoxy-1,4-poly(phenylenevinylene) (DBPPV). The current and luminance characteristics of devices with ZnO nanoparticles are much better than those of device with pure DBPPV. Optimized maximum luminance efficiencies of DBPPV–ZnO (3:1 wt%) before annealing (1.78 cd/A) and after annealing (2.45 cd/A) having a brightness 643 and 776 cd/m2at a current density of 36.16 and 31.67 mA/cm2are observed, respectively. Current density–voltage and brightness–voltage characteristics indicate that addition of ZnO nanoparticles can facilitate electrical injection and charge transport. The thermal annealing is thought to result in the formation of an interfacial layer between emissive polymer film and cathode.
CdSe Ring- and Tribulus-Shaped Nanocrystals: Controlled Synthesis, Growth Mechanism, and Photoluminescence Properties
Authors: Hu Pengfei , Jia Dianzeng , Cao Yali , Huang Yudai , Liu Lang , Luo Jianmin
Published: February 2009

With air-stable and generic reagents, CdSe nanocrystals with tunable morphologies were prepared by controlling the temperature in the solution reaction route. Thereinto, the lower reaction temperature facilitates the anisotropic growth of crystals to obtain high-yield CdSe ring- and tribulus-shaped nanocrystals with many branches on their surfaces. The photoluminescence properties are sensitive to the nature of particle and its surface. The products synthesized at room temperature, whose surfaces have many branches, show higher blue shift and narrower emission linewidths (FWHM) of photoluminescence than that of samples prepared at higher temperature, whose surfaces have no branches. Microstructural studies revealed that the products formed through self-assembly of primary crystallites. Nanorings formed through the nonlinear attachment of primary crystallites, and the branches on the surfaces grew by linear attachment at room temperature. And the structure of tribulus-shaped nanoparticle was realized via two steps of aggregation, i.e., random and linear oriented aggregation. Along with the elevation of temperature, the branches on nanocrystal surfaces shortened gradually because of the weakened linear attachment.
Effect of β‐Cyclodextrin on trans Fats, CLA, PUFA and Phospholipids of Milk Fat
Authors: Alonso L. , Cuesta P. , Gilliland S. E.
Published: February 2009

The aim of this study was to evaluate the effect of β‐cyclodextrin (β‐CD) on trans C18:1 fatty acid isomers, conjugated linoleic acid (CLA), polyunsaturated fatty acids (PUFA) and phospholipids in pasteurized milk. The individual trans C18:1 isomers were not significantly affected by the β‐CD. trans‐11 C18:1 (vaccenic acid) was found to be the major isomer (1.31 ± 0.12%) followed by trans‐15 C18:1 (0.35 ± 0.06%). Individual trans linoleic acids did not show differences from the effect of β‐CD, representing the high amount of the isomer trans‐11 cis‐15 C18:2 (0.433 ± 0.087%). The main CLA isomer cis‐9 trans‐11 C18:2 (rumenic acid) did not show differences between the control milk (0.672 ± 0.080%) and β‐CD milk (0.663 ± 0.074%). PUFA and omega‐3 and ‐6 fatty acids were not also significant by the effect of β‐CD. Total phospholipids were not significantly affected by effect of the β‐CD (0.023 ± 0.001% vs. 0.022 ± 0.001%). β‐CD is a effective oligosaccharide for cholesterol removal from pasteurized milk and does not significantly affect the lipid components of the milk fat.
Assessment of fertility by sperm mechanical energy using computer‐assisted sperm analysis system
Authors: Isobe Tetsuya
Published: February 2009

Purpose

It is known that the energy distribution of sperm obeys the following equations and the total mechanical energy in a sperm population is expressed as nKλ × a constant. nKλ/102 is defined as the sperm energy index (SEI).
urn:x-wiley:14470578:rmb20004:equation:rmb20004-math-0001

Here, P is the existing probability density of sperm, t is the square of amplitude of lateral head displacement, λ is the mean of t, n is the number of motile sperm in semen in a measurement field, and K is a constant determined for each semen sample. These values can be obtained with the use of computer‐assisted sperm analysis (CASA).

Methods

Sperm motility parameters were measured using CASA in 163 ejaculated semen samples from 47 infertile men (infertility group), and 162 ejaculated semen samples from 45 fertile men (natural pregnancy group). Kλ is defined for the present investigation as the mean energy index (MEI). SEI and MEI were obtained according to the methods described in sperm energy theory.

Results

There were no natural pregnancy subjects with SEI < 0.5. All subjects with MEI > 2.0 and SEI > 1.0 were in the natural pregnancy group.

Conclusions

An assessment of fertility was possible by using the sperm energy index.
Effect of relaxin and IGF‐I on the pre‐implantation development of Mongolian gerbil (Meriones unguiculatus) embryos in vitro
Authors: Yoshida Mayumi , Obata Ryuichiro , Tsujii Hirotada
Published: February 2009

Purpose

Both relaxin and insulin‐like growth factor (IGF) are members of the insulin super family. This study aimed to investigate the effect of relaxin and IGF‐I on the pre‐implantation of Mongolian gerbil of blastocyst development in vitro.

Methods

Blastocysts and eight‐cell stage embryos were collected from female gerbils. Eight‐cell embryos and blastocysts were cultured in mM16 medium supplemented with or without relaxin or IGF‐I for 24 h. Blastocysts were counted for total, inner cell mass (ICM) and trophectoderm (TE) cell numbers, and assessed apoptosis incidence. In addition, to measure incorporation of 3H‐methionine, blastocysts were cultured for 3 h with relaxin or IGF‐I, washed with trichloroacetic acid and measured by liquid scintiration counter.

Results

Relaxin (200 ng/ml) increased total, TE and ICM cell numbers of blastocyst (P < 0.05) when it was compared with the control. IGF‐I (150 ng/ml) also has influence on total and ICM cell numbers of blastocyst when compared with control. Apoptosis incidence was relatively low, and a significant difference was not observed between each group. The effect of relaxin on incorporation of 3H‐methionine was higher than the control group (P < 0.05). Relaxin increased the developmental rate from the eight‐cell stage to blastocyst (P < 0.05).

Conclusions

In conclusion, relaxin and IGF‐I stimulated protein synthesis and increased cell numbers of blastocysts, promoting development of the gerbil embryo in vitro culture.
Attachment and self‐evaluation in Chinese adolescents: Age and gender differences
Authors: Song Hairong , Thompson Ross A. , Ferrer Emilio
Published: February 2009

This study investigated age and gender differences in the quality of attachment to mothers, fathers, and peers, and the association of attachment with measures of self‐evaluation in 584 Chinese adolescents in junior high, high school, and university. Their responses to the Inventory of Parent and Peer Attachment indexed attachment quality, and self‐evaluation was measured by the Rosenberg Self‐Esteem Scale and the Self‐Liking and Self‐Competence Scale. Consistent with findings with Western samples, our analyses revealed (a) lower parent–child relationship quality in middle (compared to early) adolescence, (b) a significant association of parental and peer attachment with self‐evaluation, and (c) gender differences in attachment to peers, with females reporting stronger attachment than males. Chinese females reported stronger maternal attachment than did males, and for females the quality of maternal attachment was more strongly related to self‐evaluation than any other attachment relationship. During high school, peer attachment quality – rather than parental – was preeminently associated with self‐evaluation. The findings of this study indicate that in a context of considerable consistency of findings with Western studies, parent–child attachment in Chinese adolescents is also influenced by culture‐specific practices that influence parent–youth relationships and their meaning to the child.
Establishing in vitro Zinnia elegans cell suspension culture with high tracheary element differentiation
Authors: Twumasi Peter , Schel Jan H.N. , Van Ieperen Wim , Woltering Ernst , Van Kooten Olaf , Emons Anne Mie C.
Published: February 2009

The Zinnia elegans mesophyll cell culture is a useful system for xylogenesis studies. The system is associated with highly synchronous tracheary element (TE) differentiation, making it more suitable for molecular studies requiring larger amounts of molecular isolates, such as mRNA and proteins and for studying cellulose synthesis. There is, however, the problem of non‐uniformity and significant variations in the yields of TEs (%TE). One possible cause for this variability in the%TE could be the lack of a standardized experimental protocol in various research laboratories for establishing the Zinnia culture. Mesophyll cells isolated from the first true leaves of Z. elegans var Envy seedlings of approximately 14 days old were cultured in vitro and differentiated into TEs. The xylogenic culture medium was supplied with 1 mg/l each of benzylaminopurine (BA) and α‐naphthalene acetic acid (NAA). Application of this improved culture method resulted in stable and reproducible amounts of TE as high as 76% in the Zinnia culture. The increase was mainly due to conditioning of the mesophyll cell culture and adjustments of the phytohormonal balance in the cultures. Also, certain biochemical and cytological methods have been shown to reliably monitor progress of TE differentiation. We conclude that, with the adoption of current improvement in the xylogenic Z. elegans culture, higher amounts of tracheary elements can be produced. This successful outcome raises the potential of the Zinnia system as a suitable model for cellulose and xylogenesis research.
Molecular shape and prominent role of β‐strand swapping in organization of dUTPase oligomers
Authors: Takács Enikő , Barabás Orsolya , Petoukhov Maxim V. , Svergun Dmitri I. , Vértessy Beáta G.
Published: February 2009

MINT‐6946477:dUTPase (uniprotkb:Q9V3I1) and dUTPase (uniprotkb:Q9V3I1) bind (MI:0407) by X‐ray crystallography (MI:0114)
Reassessment of the role of FKBP38 in the Rheb/mTORC1 pathway
Authors: Uhlenbrock Katharina , Weiwad Matthias , Wetzker Reinhard , Fischer Gunter , Wittinghofer Alfred , Rubio Ignacio
Published: February 2009

MINT‐6946517: RAF (uniprotkb:P04049) binds (MI:0407) to Ha‐Ras (uniprotkb:P01112) by pull down (MI:0096)
Heterorhabditis gerrardi n. sp. (Nematoda: Heterorhabditidae): the hidden host of Photorhabdus asymbiotica (Enterobacteriaceae: γ-Proteobacteria)
Authors: Plichta K.L. , Joyce S.A. , Clarke D. , Waterfield N. , Stock S.P.
Published: February 2009

A new entomopathogenic nematode species from Australia, Heterorhabditis gerrardi n. sp. (Nematoda: Heterorhabditidae) is described. Morphological and molecular studies together with cross-hybridization tests indicated that this nematode represents a new undescribed species, closely related to members in the ‘indica-group’. However, the new species can be distinguished from other species in this genus by a combination of several qualitative and quantitative morphological traits. Key diagnostic features include: body size and excretory pore position of the third-stage infective juveniles; male bursa with a reduction of bursal rays, usually affecting the terminal set of papillae, with symmetrical or asymmetrical loss of one or two pairs; vulva of hermaphrodites more anteriorly located than in other species in the indica-group (V% average: 43), with non-protruding or slightly protruding lips, and longer tail length (average: 106 μm). The new species can be further characterized by molecular traits of sequence data from the internal transcribed spacer (ITS) region of ribosomal DNA. Additionally, the bacterial symbiont of this new species, Photorhabdus asymbiotica Kingscliff strain, was phenotypically characterized and compared with other P. asymbiotica strains. The Kingscliff strain revealed many characters not present in other strains of this species. We hypothesize that the newly found traits may contribute to the maintenance of this mutualistic association of the bacterium with its nematode host.
Computed tomography and/or magnetic resonance imaging for pre-operative planning for inverted nasal papilloma: review of evidence
Authors: Karkos P D , Khoo L C , Leong S C , Lewis-Jones H , Swift A C
Published: February 2009

Background:

Inverted nasal papilloma is a benign tumour with variable biological behaviour. It is a unique neoplasm and is often difficult to manage, being characterised by a tendency to recur following excision, an association with malignancy and an ability to destroy bone. Radiological diagnosis has traditionally been based on computed tomography, but it is often impossible to differentiate between polyps with entrapped debris and inverted nasal papilloma. Magnetic resonance imaging, especially T2-weighted images, is perhaps a better tool in differentiating inverted nasal papilloma from other nasal lesions, and has recently been advocated as the imaging modality of choice.

Aims:

To review the evidence on the ideal imaging modality for pre-operative planning of surgery for patients with histologically proven inverted nasal papilloma.

Materials and methods:

A systematic review of studies was undertaken, focusing on radiological assessment of inverted nasal papilloma (primary and recurrent). All English language articles were potentially included in the review. However, we excluded single case reports, case series, pictorial essays, ‘teaching’ reviews and reviews of inverted nasal papilloma not focusing on pre-operative imaging.

Results:

Sixteen studies were identified based on our search strategy. Only 10 fulfilled our criteria. Computed tomography scanning was the standard imaging modality of choice for assessing sinus involvement of inverted papilloma and for planning the extent of surgery. T2-weighted magnetic resonance imaging scans were able to distinguish tumour (intermediate signal) from inflammatory tissues (bright signal), but not post-operative scarring from recurrent tumour. No studies were found which compared the specificity and sensitivity of magnetic resonance imaging and computed tomography in the accurate pre-operative identification of the extent of inverted papilloma.

Conclusions:

There is currently not enough evidence to suggest one sole modality as providing optimum imaging for inverted nasal papilloma. Computed tomography remains the imaging modality of first choice for inverted nasal papilloma, despite certain disadvantages. Magnetic resonance imaging is able to distinguish tumour from inflammation and is advocated as a better tool for recurrent tumour, but bone destruction of sinus walls is less easy to recognise, compared with computed tomography. Evaluation of sinus tumours usually involves both imaging modalities, and inverted nasal papilloma should be included within this pathological group. The cohort of patients is usually small, so cost-effectiveness should not generally be an issue when considering whether to use computed tomography, magnetic resonance imaging or both. A well structured, prospective study is needed to evaluate the efficacy of magnetic resonance imaging versus computed tomography for pre-operative planning of histologically proven inverted nasal papilloma.
Topical chemoprevention of skin cancer in mice, using combined inhibitors of 5-lipoxygenase and cyclo-oxygenase-2
Authors: Fegn L , Wang Z
Published: February 2009

Objective:

Skin cancer is the most common cancer, and often occurs in the head and neck region. This study aimed to investigate whether a combination of inhibitors of cyclo-oxygenase-2 and 5-lipoxygenase, applied via a microemulsion delivery system, would be effective in topically inhibiting skin carcinogenesis.

Study design:

Randomised animal study.

Methods:

Twenty-four nude mice were intradermally inoculated with carcinoma cells and then divided into three groups (eight animals each): group one received no treatment; group two received celecoxib alone; and group three received a combination of zileuton and celecoxib. Tumour incidence and growth were measured for 14 days.

Results:

Both treatments significantly delayed the onset and development of tumours. However, the combined treatment had the best response (p < 0.01).

Conclusion:

The results clearly showed that topical treatment with either celecoxib alone or celecoxib plus zileuton significantly inhibited skin carcinogenesis, and that a combination of both agents had the best results.
DYNAMIC ROUTING OF CUSTOMERS WITH GENERAL DELAY COSTS IN A MULTISERVER QUEUING SYSTEM
Authors: Argon Nilay Tanik , Ding Li , Glazebrook Kevin D. , Ziya Serhan
Published: February 2009

We consider a network of parallel service stations each modeled as a single-server queue. Each station serves its own dedicated customers as well as generic customers who are routed from a central controller. We suppose that the cost incurred by a customer is an increasing function of her time spent in the system. In a significant advance on most previous work, we do not require waiting costs to be convex, still less linear. With the objective of minimizing the long-run average waiting cost, we develop two heuristic routing policies, one of which is based on dynamic programming policy improvement and the other on Lagrangian relaxation. In developing the latter policy, we show that each station is “indexable” under mild conditions for customers’ waiting costs and also prove some structural results on the admission control problem that naturally arises as a result of the Lagrangian relaxation. We then test the performance of our heuristics in an extensive numerical study and show that the Lagrangian heuristic demonstrates a strong level of performance in a range of traffic conditions. In particular, it clearly outperforms both a greedy heuristic, which is a standard proposal in complex routing problems, and a recent proposal from the heavy traffic literature.
ON THE TIME-DEPENDENT OCCUPANCY DISTRIBUTION OF THE G/G/1 QUEUING SYSTEM
Authors: Limón–Robles Jorge , Wortman Martin A.
Published: February 2009

This article offers an approach for studying the time-dependent occupancy distribution for a modest generalization of the GI/G/1 queuing system in which interarrival times and service times, although mutually independent, are not necessarily identically distributed. We develop and explore an analytical model leading to a computational approach that gives tight bounds on the occupancy distribution. Although there is no general closed-form characterization of probability law dynamics for occupancy in the GI/G/1 queue, our results offer what might be termed “near-closed-form” in that accurate plots of the transient occupancy distribution can be constructed with an insignificant computational burden. We believe that our results are unique; we are unaware of any alternative analytical approach leading to a numerical characterization of the time-dependent occupancy distribution for the G/G/1 queuing systems considered here.

Our analyses employ a marked point process that converges to the occupancy process at any fixed time t; it is shown that this process forms a Markov chain from which the transient occupancy law is available. We verify our analytical approach via comparison with the well-known closed-form expressions for time-dependent occupancy distribution of the M/M/1 queue. Additionally, we suggest the viability of our approach, as a computational means of obtaining the time-dependent occupancy distribution, through straightforward application to a Gamma[x]/Weibull/1 queuing system having batch arrivals and batch job services.
FORECAST ERRORS IN SERVICE SYSTEMS
Authors: Steckley Samuel G. , Henderson Shane G. , Mehrotra Vijay
Published: February 2009

We investigate the presence and impact of forecast errors in the arrival rate of customers to a service system. Analysis of a large dataset shows that forecast errors can be large relative to the fluctuations naturally expected in a Poisson process. We show that ignoring forecast errors typically leads to overestimates of performance and that forecast errors of the magnitude seen in our dataset can have a practically significant impact on predictions of long-run performance. We also define short-run performance as the random percentage of calls received in a particular period that are answered in a timely fashion. We prove a central limit theorem that yields a normal-mixture approximation for its distribution for Markovian queues and we sketch an argument that shows that a normal-mixture approximation should be valid in great generality. Our results provide motivation for studying staffing strategies that are more flexible than the fixed-level staffing rules traditionally studied in the literature.
A STATE-DEPENDENT POLLING MODEL WITH k-LIMITED SERVICE
Authors: Winands E. M. M. , Adan I. J. B. F. , van Houtum G. J. , Down D. G.
Published: February 2009

We consider a two-queue model with state-dependent setups, in which a single server alternately serves the two queues. The high-priority queue is served exhaustively, whereas the low-priority queue is served according to the k-limited strategy. A setup at a queue is incurred only if there are customers waiting at the polled queue. We obtain the transforms of the queue length and sojourn time distributions under the assumption of Poisson arrivals, generally distributed service times, and generally distributed setup times. The interest for this model is fueled by an application in the field of logistics. It is shown how the results of this analysis can be applied in the evaluation of a stochastic two-item single-capacity production system. From these results we can conclude that significant cost reductions are possible by bounding the production runs of the low-priority item, which indicates the potential of the k-limited service discipline as priority rule in production environments.
The contrastive hypothesis for the acquisition of word meaning: a reconsideration of the theory
Authors: Gathercole Virginia C.
Published: February 2009

The evidence for the Contrastive Hypothesis (Clark 1980, 1983a, b, 1987, Barrett 1978, 1982) is reviewed. An examination of data from the acquisition of object words, relational words and superordinate terms reveals little support for this hypothesis that young children automatically assume that every two words in their lexicons contrast. Further, theoretical problems with the positions that children assign words to semantic fields as they are acquiring them and that innovations are used to fill lexical gaps make these stances untenable.
The acquisition of temporal terms
Authors: Stevenson Rosemary J. , Pollitt Caroline
Published: February 2009

An experiment is described which investigates preschool children's understanding of temporal terms. Children aged 2;11 to 4;5 were required to act out situations described by sentences containing before and after. One set of sentences used both a simplified task and simplified materials. These sentences were simple commands, and they only required the children to act out the situation described by the main clause in order to demonstrate comprehension. Performance with these sentences was superior to performance with sentences like those of Clark (1971) and Grain (1982). In addition, children only used an order-of-mention strategy with the Clark sentences. With both the Clark and the Grain sentences, there were more omissions of the subordinate clause in before sentences than in after sentences. There was also a tendency, with these two types of sentence, for children to act out only the first clause in before sentences.
The acquisition of agglutinating languages: converging evidence from Tamil
Authors: Raghavendra Parimala , Leonard Laurence B.
Published: February 2009

The acquisition of verb inflections in Tamil, an agglutinating language, was investigated in three 2-year-old children. The findings revealed a high percentage use of verb inflections indicating tense, aspect, modality, person, number and gender by all three children. Explanations for this early, almost error-free acquisition are discussed in terms of the facilitating properties of agglutinating languages.