bluuebunny/crossref_metadata_2025 huggingface dataset:
The factor time at the formation and development of the passive layer in the atmosphere
Authors: Bierwirth M. , Goellner J. , Heyn A. , Winkelmans M.
Published: December 2007

Passive layers on high alloyed chromium nickel steels protect the metal from corrosion. The protective effect of the passive layer, however, does not immediately exist after the final surface treatment. Some time is necessary to form the protective layer. The exposure conditions are also decisive for the formation and further development of the passive layer besides the surface treatment. Samples of different chromium nickel steels are pickled and active passivated before they are exposed under laboratory conditions and in outdoor climates at different locations. The state of the corrosion resistance of the surface is determined with electrochemical noise measurements after different exposure times. The decreasing activity of the surface with an increasing exposure time indicates the further formation process of the protective qualities of the passive layer. An index which quantifies the state of the surface at the time of the measuring is calculated from the measured potential and potential noise signals. With these results, the development of the passive layer can be assessed and the corrosion resistance of the metal can then be estimated.
Electrochemical noise measurements on unalloyed steel in chloride‐containing alkaline environment
Authors: Eichler T. , Burkert A. , Beck M.
Published: December 2007

The investigations discussed in this paper aim to clarify whether electrochemical noise measurements (ENM) are capable for application in concrete and mortar, particularly with regard to pitting initiation in such environment. For these purposes, the results of several different test series are compared and discussed. Based on investigations on passivity and pitting corrosion in alkaline solutions with different chloride contents further results in cement paste, mortar and concrete are evaluated.
Synthesis and Study of CdS Nanoparticle‐Doped Poly(1,4‐dihexyloxybenzene)
Authors: Paul Gouri Sankar , Sarmah Pranjol Jyoti , Iyer Parameswar Krishnan , Agarwal Pratima
Published: December 2007

A simple, economical and high yielding method to prepare poly(1,4‐dihexyloxybenzene), an alkylated derivative of poly(para‐phenylene) (PPP), is reported. We further prepared a composite of poly(1,4‐dihexyloxybenzene) and CdS nanoparticles and studied their structural, optical, stability and transport properties. It was observed that the conductivity of poly(1,4‐dihexyloxybenzene) increased by several orders of magnitude when doped with CdS nanoparticles. Similarly, CdS nanoparticle‐doped PPP showed higher thermal stability, when compared to the neat polymer. As these composites could be processed in the same way as organic polymers, they would find applications in many low‐cost optoelectronic devices.

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Salt‐Induced Micelle Behavior of Poly(sodium acrylate)‐block‐Poly(N‐isopropylacrylamide) by ATRP
Authors: Jin Shuping , Liu Mingzhu , Chen Shilan , Gao Chunmei
Published: December 2007

Temperature‐ and pH‐sensitive diblock copolymers PAANa75‐b‐PNIPAMm are prepared by a combination of reverse and normal ATRP in aqueous solution at room temperature. The block copolymer is also stimuli‐sensitive with respect to salt in the aqueous solution, and forms spherical star‐like micelles with a PNIPAM core and an expanded PAANa shell for PAANa75‐b‐PNIPAM76 as well as spherical crew‐out micelles with a PNIPAM core for PAANa75‐b‐PNIPAM5110, as indicated by a fluorescence probe technique and TEM. A three‐stage model mechanism of phase transition driven by small molecule salt is proposed.

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Features, Questions and Future Challenges in Layered Silicates Clay Nanocomposites with Semicrystalline Polymer Matrices
Authors: Harrats Charef , Groeninckx Gabriel
Published: December 2007

The present features review article discusses the crystallisation of the polymer matrix when containing silicate layers. The accent is put on nylons (polyamides) and poly(ethylene oxide) as typical hydrophilic polymers and, poly(propylene) from the hydrophobic group. The effects of the clay, either intercalated or exfoliated, on the crystallisation behaviour of the matrix are highlighted. In addition, the crucial aspects of the semicrystalline morphology of the matrix in the presence of the clay platelets are also debated. The overall crystallisation rate is reported to slow down for most of the crystallisable polymer matrices on account of a retarding growth effect exerted by the clay platelets. As far as the location of the exfoliated clay platelets in the polymer matrix is concerned, they are assumed to be rejected from the crystalline phase in the interspherulitic space.

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Concurrent hemichorea and migrainous aura—A perfusion study on the basal ganglia using xenon‐computed tomography
Authors: Yamada Kazumichi , Harada Mikio , Inoue Nobuhiro , Yoshida Shinsuke , Morioka Motohiro , Kuratsu Jun‐Ichi
Published: December 2007

A variety of etiologies underlie the neurophysiological imbalance resulting in chorea. We report a 57‐year‐old woman with a long‐history of migraine who suddenly experienced concurrent scintillating scotoma and rapid involuntary movement of her neck and right extremities. Diffusion‐weighted magnetic resonance imaging (MRI) failed to detect any fresh ischemic and/or hemorrhagic lesions. Xenon‐computed tomography (CT) disclosed gross reduction in the cerebral blood flow (CBF) of the left occipital area. With precise mapping to the brain atlas, extreme hyperperfusion in the motor thalamus was found on the left side. Asymmetrical CBF reduction of the left subthalamic nucleus was also noted. Her symptoms gradually improved and completely disappeared within 15 days. Repeated xenon‐CT 1 month post‐onset demonstrated normalized CBF in the affected areas. Our study suggests that vascular event underlies the migrainous aura in this case and secondarily provokes a loss of inhibitory control of the motor thalamus resulting in the manifestation of hemichorea. © 2007 Movement Disorder Society
Chorea‐ballism associated with familial amyotrophic lateral sclerosis. A clinical, genetic, and neuropathological study
Authors: Gamez Josep , Corbera‐Bellalta Marc , Mila Montserrat , López‐Lisbona Rosa , Boluda Susana , Ferrer Isidre
Published: December 2007

Hyperkinetic movements in amyotrophic lateral sclerosis (ALS) are extremely rare. We present clinical, neuropathological, and genetic data for a 53‐year‐old woman with spinal onset ALS presenting chorea affecting the face, mouth, neck, and hands, and ballism in both arms 31 months after leg weakness onset. Her father and older sister had ALS, but had no movement disorders. As well as the typical neuropathological findings of ALS (marked upper and lower motor neuron loss), post‐mortem examination showed prominent neuronal loss and gliosis in the subthalamus, and in the internal globus pallidus, substantia nigra pars compacta, and red nucleus. No abnormalities were found in the caudate, putamen, and thalamus. No defects were found in the SOD1, HD, and DRPLA genes. These data support the idea that choreo‐ballism in ALS Plus may be the result of pallido‐luyso‐rubro‐nigral atrophy, despite not being the result of concomitant DRPLA based on neuropathological and genetic criteria. © 2007 Movement Disorder Society
Investigation of an unusual, high‐frequency jaw tremor with coherence analysis
Authors: Sowman Paul F. , Thompson Philip D. , Miles Timothy S.
Published: December 2007

Normal physiological tremor of the jaw has a frequency of 6 to 8 Hz. A patient is described with jaw tremor at frequencies of 12 Hz during jaw movement and 15 Hz when the jaw was relaxed. The 15 Hz tremor was driven by synchronous, bilateral bursts of activity in the temporalis and masseter muscles, which alternated with digastric bursts. Coherence analysis indicated the tremor was highly correlated with both opening and closing muscle activity, and that the opening and closing muscles were about 180° out of phase. The existence of two tremors with different, nonphysiological peak frequencies and the influence of attention, relaxation, and movement in switching from one tremor frequency to the other, suggest that more than one generator may be operating. © 2007 Movement Disorder Society
Rasagiline improves freezing in a patient with primary progressive freezing gait
Authors: Coria Francisco , Cozar‐Santiago María del Puig
Published: December 2007

We herein report the case of a 84‐year‐old man with a 4‐year history of freezing of gait (FOG) consistent with the diagnosis of primary progressive freezing gait. Single photon emission tomography (SPECT) with a radiolabeled ligand of the dopamine transporter (DAT‐SPECT) showed integrity of striatal dopaminergic terminals, whereas brain perfusion SPECT disclosed multiple areas of decreased perfusion in frontal and parietal lobes, as well as in the subcortical gray nuclei of both sides. Treatment with the new irreversible monoamine oxidase B inhibitor rasagiline at standard doses resulted in a rapid, dramatic, and sustained improvement of the frequency and duration of FOG episodes. In addition, brain perfusion SPECT after treatment showed a marked increase of the activity in all cortical areas as well as in the basal ganglia and thalamus. Rasagiline may prove to be an effective and safe treatment for this disabling condition. © 2007 Movement Disorder Society
Comparison of perception threshold testing and thermal‐vibratory testing
Authors: Lowenstein Lior , Jesse Kathy , Kenton Kimberly
Published: December 2007

Current perception threshold testing (CPT) is thought to selectively activate and measure three types of afferent nerves. However, it has not been standardized or compared with better‐studied methods of sensory testing. Our objectives were to determine the relationship between CPT (2000 Hz, 250 Hz, 5 Hz) and quantitative sensory testing (QST) using vibratory and heat thresholds, and to assess the test–retest reliability of both methods. Twenty‐seven healthy women were enrolled. Each woman underwent CPT and QST on the volar part of the arm. Sensory thresholds were determined by the method of limits; 20 women underwent repeated CPT testing and QST after 1 week to determine test–retest reliability. Thermal thresholds were moderately correlated with CPT at 5 Hz (ρ = 0.49, P = 0.009), as were vibratory thresholds and CPT at 2000 Hz (ρ = 0.5, P = 0.008). In contrast to CPT measurements, warm and vibratory and cold thresholds were correlated 1 week apart (ρ = 0.73, P = 0.0001; ρ = 0.83, P = 0.0001; and ρ = 0.47, P = 0.0037, respectively). CPT testing and QST seem to be measuring similar afferent nerve‐fiber populations, but QST has better test–retest reliability than CPT testing, justifying its role in clinical or research studies. Muscle Nerve, 2007
Increased PFK activity and GLUT4 protein content in McArdle's disease
Authors: Robertshaw Holly A. , Raha Sandeep , Kaczor Jan J. , Tarnopolsky Mark A.
Published: December 2007

Inborn errors of metabolism represent an opportunity to conduct studies in order to understand compensatory adaptations to a defective metabolic pathway. We evaluated the molecular and biochemical adaptations in substrate metabolism (glycolysis, electron transport chain, tricarboxylic acid cycle, β‐oxidation) in response to myophosphorylase deficiency in skeletal muscle from 13 patients with McArdle's disease (MD) and 13 age‐matched controls. MD muscle had higher phosphofructokinase protein content and activity as well as glucose transporter 4 (GLUT4) protein content and lower GLUT4 mRNA content than controls. At the protein level, skeletal muscle adaptations suggest an augmented glucose transport and glycolytic flux as a compensatory metabolic strategy to a chronic absence of muscle glycogen phosphorylase. These results support previous findings of increased glucose uptake during exercise and alleviation of symptoms with oral sucrose in patients with MD. Muscle Nerve, 2007
MR measurement of blood flow in the parotid gland without contrast medium: a functional study before and after gustatory stimulation
Authors: Schwenzer Nina F. , Schraml Christina , Martirosian Petros , Boss Andreas , Claussen Claus D. , Schick Fritz
Published: December 2007

Purpose

To investigate the feasibility of blood flow imaging in the parotid gland using the arterial spin labeling (ASL) technique for assessment of functional changes in the parotid gland after gustatory stimulation.

Materials and Methods

Anatomical and ASL imaging of the parotid gland was performed in eight healthy volunteers before and after gustatory stimulation over a period of 17 min. All measurements were carried out in a 1.5 T whole‐body MR unit. ASL and data recording were performed with an adapted FAIR TrueFISP (flow‐sensitive alternating inversion‐recovery true fast imaging with steady precession) technique. Maps of estimated tissue blood inflow in both parotid glands were derived using a simplified model and the extended Bloch equations.

Results

Delineation of the parotid glands was possible on FAIR TrueFISP images in all cases. In the 160 s period immediately after stimulation, a significant (P < 0.01) mean increase of 62% in the estimated parotid blood flow was observed. Estimated baseline blood flow before gustatory stimulation ranged from 226 to 500 mL/min/100 g (mean ± SD 335 ± 86). These rates increased in the 160 s immediately after stimulation to 404–772 mL/min/100 g (mean 542 ± 108). In all volunteers, blood flow returned to near baseline values within the observation period. No statistically significant difference between the right and left parotid was observed in baseline and peak blood flow.

Conclusion

ASL FAIR TrueFISP is feasible for functional characterization of the parotid glands. Assessment of changes in blood flow in the parotid gland could serve as a diagnostic tool in patients suffering from xerostomia. Copyright © 2008 John Wiley & Sons, Ltd.
Green's function evaluation for three‐dimensional exponentially graded elasticity
Authors: Criado R. , Gray L. J. , Mantič V. , París F.
Published: December 2007

The numerical implementation of Green's function for an isotropic exponentially graded three‐dimensional elastic solid is reported. The formulas for the non‐singular ‘grading term’ in this Green's function, originally deduced by Martin et al. (Proc. R. Soc. Lond. Ser. A 2000; 458:1931–1947), are quite complicated, and a small error in one of the formulas is corrected. The evaluation of the fundamental solution is tested by employing an indirect boundary integral formulation using a Galerkin approximation to solve several problems having analytic solutions. The numerical results indicate that Green's function formulas, and their evaluation, are correct. Copyright © 2007 John Wiley & Sons, Ltd.
Pre‐eclampsia is associated with dendritic cell recruitment into the uterine decidua
Authors: Huang SJ , Chen C‐P , Schatz F , Rahman M , Abrahams VM , Lockwood CJ
Published: December 2007

Pre‐eclampsia is a leading cause of fetal and maternal morbidity and mortality that preferentially affects primiparous patients. It is associated with systemic inflammation and impaired trophoblast invasion of the decidua. Decidual cells are the major cell type of the pregnant endometrium. Macrophages and dendritic cells are major specialized antigen‐presenting cells that promote both innate immunity and immune tolerance. Macrophage infiltration is implicated in impaired trophoblast invasion that leads to pre‐eclampsia. By contrast, the potential modulating role of decidual dendritic cells in the genesis of pre‐eclampsia has not been investigated. Interleukin‐1beta (IL‐1β), a pro‐inflammatory cytokine, has been implicated in the genesis of pre‐eclampsia. Thus, we postulate that pre‐eclampsia would be associated with enhanced decidual dendritic cells infiltration and that IL‐1β would enhance the production of relevant dendritic cell‐recruiting chemokines. We used immunohistochemistry to demonstrate a marked infiltrate of immature and mature dendritic cells in pre‐eclamptic decidua. Further, immunohistochemistry and immunoassays of placental bed biopsies revealed that pre‐eclamptic decidua displays elevated levels of several monocyte‐ and dendritic cell‐recruiting chemokines. Leukocyte‐free first‐trimester decidual cells were then treated with IL‐1β, which enhanced the mRNA and protein expression of these chemokines. The current study also confirmed previous reports that macrophages directly impaired trophoblast invasion and that this inhibitory effect is augmented by the conditioned medium of IL‐1β‐treated first‐trimester decidual cells. However, unlike macrophages, dendritic cells did not directly impede trophoblast invasion. This study demonstrates that the inflammatory milieu of pre‐eclampsia induces decidual cells to promote dendritic cell infiltration. Given their unusual versatility in mediating both immunity and tolerance, these novel findings suggest that dendritic cells may play a critical role either in the pathogenesis of pre‐eclampsia or its prevention in subsequent pregnancies. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
BMP‐6 over‐expression in prostate cancer is associated with increased Id‐1 protein and a more invasive phenotype
Authors: Darby S , Cross SS , Brown NJ , Hamdy FC , Robson CN
Published: December 2007

Bone morphogenetic protein‐6 (BMP‐6) has been strongly implicated in prostate cancer development and bone metastasis. Our previous data showed that BMP‐6 mRNA was absent in patients with benign prostatic hyperplasia, but evident in primary tumours with established secondary skeletal metastases. To examine the role of BMP‐6 in prostate cancer progression, we have developed a BMP‐6‐regulatable, doxycycline‐inducible gene expression system. BMP‐6 induction by doxycycline addition led to increased levels of BMP‐6 RNA and protein, associated with nuclear translocation of SMADs and activation of the downstream target gene Id‐1. BMP‐6 protein did not enhance the proliferation rate of PC3M cells but did significantly increase the rate of migration and invasion in both PC3M and DU145 cells. Increased metalloproteinase (MMP‐1 and MMP‐9) mRNA levels were also observed following BMP‐6 induction. Luciferase reporter assays confirmed BMP‐6‐mediated activation of MMP‐1 and MMP‐9 promoters, indicating direct transcriptional activation of MMPs by BMP‐6. BMP‐6 stimulation also led to an increase in phosphorylation levels of MAPK proteins. We next examined the effects of BMP‐6 on the downstream gene Id‐1 in a cohort of prostate cancer patients. A tissue microarray (TMA) was constructed and samples stained for BMP‐6 and Id‐1 expression. We observed a significant increase in the intensity of staining of epithelial BMP‐6 in the cancer cases compared to the benign cases (Mann–Whitney U test, p < 0.0005) and in the intensity of staining of epithelial Id‐1 in the cancer cases compared to the benign cases (Mann–Whitney U test, p = 0.015). We further observed a significant positive correlation between epithelial staining for Id‐1 and BMP‐6 (p = 0.001) across all samples for both benign and cancer cases. These data demonstrate that BMP‐6 promotes migration and invasion of prostate cancer cells, potentially through activation of Id‐1 and MMP activation. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Candidate biomarkers in renal cell carcinoma
Authors: Seliger Barbara , Dressler Sven P. , Lichtenfels Rudolf , Kellner Roland
Published: December 2007

Although the human genome has been decoded, the knowledge about the pathogenesis of diseases including cancer is still limited. By focusing on renal cell carcinoma (RCC) we here summarize the data of various research groups analyzing the protein/peptide expression profiles of tumor lesions/cell lines or serum obtained from patients and respective controls. Different powerful approaches such as 2‐DE, PROTEOMEX/SERPA/SPEARS, and T cell epitope discovery upon elution of MHC class I‐bound peptides in combination with MS/LC‐MS/MS revealed 500 differentially expressed proteins. The overlap in target recognition limits the pool to 299 unique protein identities, but only few thereof (12%) have been validated. The management, analysis, and interpretation of the distinct data sets derived from 27 publications required bioinformatic restructuring of the results. However, the comprehensive analysis of the results expands the knowledge about the pathophysiology of RCC in particular of the most prominent clear cell subtype by providing information on the differentially expressed proteins, their regulation status in RCC compared to normal kidney epithelium next to additional information on MHC‐presented T cell epitopes and on serological targets. Despite the low number of validated differentially expressed proteins some of them might serve as candidate biomarkers for the diagnosis and/or as therapeutic targets.
Proteomic identification of tyrosine nitration targets in kidney of spontaneously hypertensive rats
Authors: Tyther Raymond , Ahmeda Ahmad , Johns Edward , Sheehan David
Published: December 2007

Nitrosative and oxidative stress are implicated in the development of hypertension. Events in the renal medulla may play a key role in the development and progression of hypertension. This may arise through disruption of nitric oxide signalling in the medulla and be accompanied by enhanced nitrosative and oxidative stress as indicated by the presence of proteins containing 3‐nitrotyrosine. Here we demonstrate enhanced protein nitration in the medulla of spontaneously hypertensive rats. We have identified several nitrated proteins with both varied subcellular location and functional roles. These proteins are involved in nitric oxide signalling, antioxidant defense and energy metabolism. Moreover, increased nitration was observed in conjunction with enhanced oxidative damage as evidenced by the presence of protein carbonyl oxidative stress biomarkers. Our results suggest that kidney medulla is subject to enhanced nitrosative and oxidative stress, and that resulting protein modifications may contribute to the progression of hypertension.
The HcaR regulatory protein of Photorhabdus luminescens affects the production of proteins involved in oxidative stress and toxemia
Authors: Chalabaev Sabina , Turlin Evelyne , Charles Jean‐François , Namane Abdelkader , Pagès Sylvie , Givaudan Alain , Brito‐Fravallo Emma , Danchin Antoine , Biville Francis
Published: December 2007

Comparison of the proteomes of wild‐type Photorhabdus luminescens and its hcaR derivative, grown in insect hemolymph, showed that hcaR disruption decreased the production of toxins (tcdA1, mcf, and pirAB) and proteins involved in oxidative stress response (SodA, AhpC, Gor). The disruption of hcaR did not affect growth rate in insects, but did delay the virulence of P. luminescens in Bombyx mori and Spodoptera littoralis larvae. This delayed virulence was associated with a lower toxemia rather than delay in bacteremia. The disruption of hcaR also increased bacterial sensitivity to hydrogen peroxide. A sodA mutant and an hcaR mutant had similar phenotypes in terms of sensitivity to hydrogen peroxide, virulence, toxin gene expression, and growth rate in insects. Thus, the two processes affected by hcaR disruption – toxemia and oxidative stress response – appear to be related. Besides, expression of toxin genes tcdA1, mcf, and pirAB was decreased by paraquat challenge. We provide here the first demonstration of the importance of toxemia for P. luminescens virulence. Our results also highlight the power of proteomic analysis for detecting unexpected links between different, concomitant processes in bacteria.
Role of group A Streptococcus HtrA in the maturation of SpeB protease
Authors: Cole Jason N. , Aquilina John A. , Hains Peter G. , Henningham Anna , Sriprakash Kadaba S. , Caparon Michael G. , Nizet Victor , Kotb Malak , Cordwell Stuart J. , Djordjevic Steven P. , Walker Mark J.
Published: December 2007

The serine protease high‐temperature requirement A (HtrA) (DegP) of the human pathogen Streptococcus pyogenes (group A Streptococcus; GAS) is localized to the ExPortal secretory microdomain and is reportedly essential for the maturation of cysteine protease streptococcal pyrogenic exotoxin B (SpeB). Here, we utilize HSC5 (M5 serotype) and the in‐frame isogenic mutant HSC5ΔhtrA to determine whether HtrA contributes to the maturation of other GAS virulence determinants. Mutanolysin cell wall extracts and secreted proteins were arrayed by 2‐DE and identified by MALDI‐TOF PMF analysis. HSC5ΔhtrA had elevated levels of cell wall‐associated M protein, whilst the supernatant had higher concentrations of M protein fragments and a reduced amount of mature SpeB protease, compared to wild‐type (WT). Western blot analysis and protease assays revealed a delay in the maturation of SpeB in the HSC5ΔhtrA supernatant. HtrA was unable to directly process SpeB zymogen (proSpeB) to the active form in vitro. We therefore conclude that HtrA plays an indirect role in the maturation of cysteine protease SpeB.
New multiple‐herbicide crop resistance and formulation technology to augment the utility of glyphosate
Authors: Green Jerry M , Hazel Christine B , Forney D Raymond , Pugh Luann M
Published: December 2007

Glyphosate has performed long and well, but now some weed communities are shifting to populations that survive glyphosate, and growers need new weed management technologies to augment glyphosate performance in glyphosate‐resistant crops. Unfortunately, most companies are not developing any new selective herbicides with new modes of action to fill this need. Fortunately, companies are developing new herbicide‐resistant crop technologies to combine with glyphosate resistance and expand the utility of existing herbicides. One of the first multiple‐herbicide‐resistant crops will have a molecular stack of a new metabolically based glyphosate resistance mechanism with an active‐site‐based resistance to a broad spectrum of ALS‐inhibiting herbicides. Additionally, new formulation technology called homogeneous blends will be used in conjunction with glyphosate and ALS‐resistant crops. This formulation technology satisfies governmental regulations, so that new herbicide mixture offerings with diverse modes of action can be commercialized more rapidly and less expensively. Together, homogeneous blends and multiple‐herbicide‐resistant crops can offer growers a wider choice of herbicide mixtures at rates and ratios to augment glyphosate and satisfy changing weed management needs. Copyright © 2007 Society of Chemical Industry
In vitro antimicrobial and in vivo antioomycete activities of the novel antibiotic thiobutacin
Authors: Lee Jung Yeop , Sherman David H , Hwang Byung Kook
Published: December 2007

BACKGROUND: A number of synthetic fungicides are not effective when confronted by oomycete pathogens because many fungicide targets are absent from oomycetes. Moreover, resistance to fungicides has already arisen in oomycete species, and thus development of new, effective and safe compounds for use in oomycete disease control is necessary.

RESULTS: Zoospore lysis began at 10 µg mL−1 of thiobutacin, and most of the zoospores were collapsed at 50 µg mL−1. Thiobutacin also revealed inhibitory activity against the cyst germination and hyphal growth of Phytophthora capsici at 50 µg mL−1. Treatment with thiobutacin exhibited protective activity against development of Phytophthora disease on pepper plants.

CONCLUSION: The authors verified in vitro antioomycete activity of thiobutacin against P. capsici and its control efficacy against Phytophthora blight in vivo. This is the first report to demonstrate in vivo antioomycete activity of the novel antibiotic thiobutacin against P. capsici infection. Copyright © 2007 Society of Chemical Industry
Herbicides, glyphosate resistance and acute mammalian toxicity: simulating an environmental effect of glyphosate‐resistant weeds in the USA
Authors: Gardner Justin G , Nelson Gerald C
Published: December 2007

BACKGROUND: With the emergence of glyphosate‐resistant (GR) weeds, the environmental consequences of alternatives to GR technology are of increasing importance. A well‐known acute mammalian toxicity measure, the LD50 dose for rats, is used to assess one potential environmental impact of the loss of GR technology. A new dataset with this index is used to estimate and simulate the effects for corn, soybeans and cotton.

RESULTS: With conventional tillage it is found that the use of GR seeds reduces the number of LD50 doses applied per hectare by 17–98% depending on crop. With no‐till, the use of GR seeds reduces LD50 doses only in corn. If farmers switch to conventional seeds because of GR weeds but maintain the same tillage practice, the present simulations suggest that LD50 doses could increase by as much as 100 LD50 doses per hectare in soybeans, and 500 LD50 doses per hectare in cotton, or 11.4 and 19.8% respectively.

CONCLUSIONS: This is the first study to use field‐level data to assess GR technology with a mammalian toxicity environmental indicator. It has been found that GR crops have a positive environmental effect, and that alternatives to GR technology increase toxicity. Copyright © 2007 Society of Chemical Industry
Inheritance of beta‐cypermethrin resistance in the housefly Musca domestica (Diptera: Muscidae)
Authors: Zhang Lan , Shi Jing , Gao Xiwu
Published: December 2007

BACKGROUND: Beta‐cypermethrin, a synthetic pyrethroid insecticide, was applied frequently in the control of health pests including houseflies, Musca domestica L., in China. However, different levels of resistance to beta‐cypermethrin were monitored in field strains of houseflies. A strain of M. domestica, 4420‐fold resistant to beta‐cypermethrin after continuous 25 generations of selection, was used in this paper to determine the mode of inheritance of pyrethroid resistance.

RESULTS: The estimated realized heritability (h2) of beta‐cypermethrin resistance was 0.30 in this resistant strain. Results of bioassays showed no significant difference in values of LD50 and slope of log dose‐probit lines between reciprocal progenies F1 and F′1, and yielded values of − 0.10 (F1) and − 0.11 (F′1) for the degree of dominance (D). Chi‐square analysis from responses of self‐bred and backcross progenies (F2, BC1 and BC2 respectively) indicated that the null hypothesis, a single gene responsible for resistance, was accepted. The minimum number of independent segregation genes was 0.93 for F1 by Lande's method.

CONCLUSION: It was concluded that beta‐cypermethrin resistance in the housefly was inherited as a single, major, autosomal and incompletely recessive factor. These results would provide the basic information for pest management programmes. Copyright © 2007 Society of Chemical Industry
Understanding negative capacitance effect using an equivalent resistor‐capacitor circuit
Authors: Kwok H. L.
Published: December 2007

Negative capacitance effect has been observed in disordered solids and is shown to be linked to the presence of traps. Thus far, few theories have been applied rigorously to the reported (negative capacitance) data in the literature. This work continues an earlier effort to study negative capacitance effect using the Drude model. We have extended the model and have correlated it with an equivalent circuit model consisting of a resistor and a capacitor. With this model, we have derived an equation for the negative capacitance and have shown that it exists when the real and the imaginary components of the complex conductance are roughly equal and have opposite signs. We have also computed the frequency at the negative capacitance peak and have shown that it is proportional to the complex conductance and hence the complex carrier mobility. It confirms our earlier hypothesis on the “universality of photocurrent transients” in disordered organic solids when the capacitance‐frequency curves are normalized with respect to bias and temperature. Based on our results, we confirm that the negative capacitance effect arises from time delay in the current flow related to the trapped carriers. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical characterisation of Sn doped InAs grown by MOVPE
Authors: Shamba P. , Botha L. , Krug T. , Venter A. , Botha J. R.
Published: December 2007

The feasibility of tetraethyl tin (TESn) as an n‐type dopant for InAs is investigated. The electrical properties of Sn doped InAs films grown on semi‐insulating GaAs substrates by MOVPE are extensively studied as a function of substrate temperature, V/III ratio, substrate orientation and TESn flow rate. Results from this study show that Sn concentrations can be controlled over 2 orders of magnitude. The Sn doped InAs layers exhibit carrier concentrations between 2.7 x 1017 and 4.7 x 1019 cm–3 with 77 K mobilities ranging from 12 000 to 1300 cm2/Vs. Furthermore, the influence of the variation of these parameters on the structural properties of InAs are also reported. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical characterization of InAs thin films
Authors: Botha L. , Shamba P. , Botha J. R.
Published: December 2007

It is known that parallel conduction as a result of surface and /or interface charge accumulation significantly shields the bulk electrical properties of InAs thin films when characterized using Hall measurements. This parallel conduction in InAs can be modeled by using the two‐layer model of Nedoluha and Koch [Zeitschrift für Physik 132, 608 (1952)]; where an InAs epilayer is treated as consisting of two conductors connected in parallel viz. a bulk and a surface layer. Here, this two‐layer model is used to simulate Hall coefficient and conductivity data of InAs thin films ranging from strongly n‐doped (n = 1018 cm–3) to strongly p‐doped (p ∼ 1019 cm–3) material. Conventional Hall approximations, i.e. those that assume uniform conduction from a single band, are then used to predict the apparent carrier concentration and mobility that will be determined from conventional Hall measurements, with the aim of illustrating the error of such a simplified analysis of InAs Hall data. Results show that, in addition to ignoring parallel conduction, the approximations of conventional Hall data analysis have a further inadequacy for p‐type InAs, in that the high electron to hole mobility ratio in InAs is not taken into account. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of ZnO thin films by second harmonic generation
Authors: Neethling P. H. , Rohwer E. G. , Bergmann H. M. Von , Stafast H.
Published: December 2007

Different samples of ZnO thin films, manufactured using different techniques, namely metal organic chemical vapour deposition (MOCVD) and pulsed laser deposition (PLD) as well as a commercial bulk sample of ZnO were examined. SHG surface scan images of the samples were recorded measuring the SH signal in reflection. The information from these measurements can be used as a measure of the thickness and uniformity of the samples. Therefore SHG has potential as an in situ monitoring method during various manufacturing processes of ZnO thin films and thin film devices. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and characterization of GaAs‐GaSb III‐V pseudo‐binary nanoparticles
Authors: Schamp C. T. , Jesser W. A.
Published: December 2007

The GaAs‐GaSb pseudo‐binary materials system presents an interesting challenge for growth because of 1) the existence of a miscibility gap in the solid‐solid portion of the equilibrium phase diagram, and 2) the large differences in vapor pressure between the column III element, Ga, and the column V elements, As and Sb. To overcome these challenges in the growth of GaAs, GaSb, and Ga50AsxSb50–x alloy nanoparticles, single‐ and dual‐target pulsed laser deposition (PLD) techniques were implemented using an Nd:YAG laser operated with a harmonic generator to utilize the second harmonic wavelength (532 nm) and a combination of the fundamental and the second harmonic wavelengths (1064 nm + 532 nm). The nanoparticles were collected on amorphous carbon films for subsequent characterization by transmission electron microscopy. The analysis shows that single phase GaAs‐rich Ga50AsxSb50–x (28 > x > 50) nanoparticles and nanocrystalline films have been formed through dual‐target, single‐wavelength (532 nm) pulsed laser ablation. Interestingly, through the ablation of the single component targets, two‐phase particles were also found to form. These two phase particles resemble “nano‐ice cream cones” with solid cones of either GaAs or GaSb with a spherical “ice cream” ball of Ga located at the wide portion of the cone, which is either an amorphous phase or liquid phase. Through an analysis by STEM‐EDX spectroscopy, these particles are found to be consistant with this model. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the processing of InAs and InSb photodiode applications
Authors: Odendaal V. , Botha J. R. , Auret F. D.
Published: December 2007

In this paper, potential methods for the surface passivation of InSb and InAs material, covering both compositional extremes of the promising narrow band gap semiconductor InAsSb, are evaluated. Surface states, mostly due to dangling bonds and exposure to the atmosphere, create generation‐recombination centres that negatively influence the dark current, stability, efficiency and related noise characteristics of photosensitive devices fabricated from these materials. The effect of various surface treatments, including sulphuric acid based etching, lactic acid based etching, KOH anodising and Na2S anodising, on the relative number of surface states is deduced by evaluating the capacitance versus voltage characteristics of metal‐insulator‐semiconductor structures fabricated on InAs and InSb. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Grid‐based density functional calculations of many‐electron systems
Authors: Roy Amlan K.
Published: December 2007

Exploratory variational pseudopotential density functional calculations are performed for the electronic properties of many‐electron systems in the 3D cartesian coordinate grid (CCG). The atom‐centered localized gaussian basis set, electronic density, and the two‐body potentials are set up in the 3D cubic box. The classical Hartree potential is calculated accurately and efficiently through a Fourier convolution technique. As a first step, simple local density functionals of homogeneous electron gas are used for the exchange‐correlation potential, while Hay‐Wadt‐type effective core potentials are employed to eliminate the core electrons. No auxiliary basis set is invoked. Preliminary illustrative calculations on total energies, individual energy components, eigenvalues, potential energy curves, ionization energies, and atomization energies of a set of 12 molecules show excellent agreement with the corresponding reference values of atom‐centered grid as well as the grid‐free calculation. Results for three atoms are also given. Combination of CCG and the convolution procedure used for classical Coulomb potential can provide reasonably accurate and reliable results for many‐electron systems. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Bound state spectra of the 3D rational potential
Authors: Roy Amlan K. , Jalbout Abraham F. , Proynov Emil I.
Published: December 2007

We present bound state spectra of the 3D rational potential, V(r) = r2 + λr2/(1 + gr2), g > 0, by means of the generalized pseudospectral method. All the 30 states corresponding to n = 0–9 are considered for the first time for a broad range of coupling parameters. These results surpass the accuracy of all other existing calculations published so far except the finite‐difference method, which yields similar accuracy as ours. Variation of energies and radial distribution functions is followed with respect to the interaction parameters. Special emphasis has been laid on higher excitations and negative values of the interaction, where relatively less work has been reported. The energy sequence is found to be different for positive and negative interaction; numerically following a mirror‐image relationship usually, if not always. Additionally, 20 energy splittings arising from certain levels belonging to n = 0–9 are systematically studied as functions of the potential parameters. Several new states (including the higher ones) are presented. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
A civilization based on sustainable development: its limits and prospects
Authors: Skowroński Antoni
Published: December 2007

Solutions to current environmental and social problems cannot be achieved on the basis of the traditional concept of development. One solution may be the idea of ‘sustainable development’, which presents a series of solutions leading to the protection and safeguarding of three thrusts to development, i.e. that of society (culture), of nature and of the economy. It assumes major modifications to our way of thinking – and to the means of civilizational development – pursued hitherto. It points to the need for the spiritual development of humankind, and for an exchange of the goals of development from the material centred to the non‐materialistic. With respect to these general assumptions and goals, sustainable development encounters many practical and psychological problems that curb (or even prevent) the effective incorporation of the concept in practice (the greatest single barrier is global unilateralism). Copyright © 2007 John Wiley & Sons, Ltd and ERP Environment.
On the benefits of diversity schemes for Bluetooth coverage extension in the presence of IEEE802.11g interference
Authors: Masini Barbara Mavì , Conti Andrea , Pasolini Gianni , Dardari Davide
Published: December 2007

This paper investigates the impact of diversity reception on the performance of Bluetooth (BT) packet transmission in wireless channels with fast fading and shadowing and in the presence of IEEE802.11g interference. In particular, selection diversity (SD) technique is considered and the adoption of this technique results in a coverage extension evaluated in the paper. We first derive a tight parametric exponential approximation for the instantaneous bit error probability (BEP) in additive white Gaussian noise (AWGN); then, from this expression, we derive the mean block error probability (BLEP) in Ricean fading channel by adopting a simple SD scheme. The analysis is then extended to the evaluation of the mean packet error probability (PEP) and the coverage probability (Pcov). In particular, the impact of the diversity order on the BLEP, PEP, andPcovis shown. Copyright © 2007 John Wiley & Sons, Ltd.
Energy and connectivity performance of routing groups in multi‐radio multi‐hop networks
Authors: Rossi Michele , Badia Leonardo , Giacon Paolo , Zorzi Michele
Published: December 2007

This paper explores the logical device aggregation of terminals in future generation networks, where the availability of several different radio access techniques is integrated by means of common radio resource management algorithms. In particular, we investigate the creation of routing groups (RGs) among adjacent nodes, which might be beneficial in order to improve connectivity, decrease signaling overhead and increase transmission efficiency. A simple analytical approach is proposed, which allows the performance evaluation of device aggregation algorithms. We measure the performance of establishing RGs with special focus on two metrics of interest: the connectivity of the nodes and the energy consumption. Within this framework, many detailed insights are obtained and presented throughout the paper. In particular, we focus on the effectiveness of these aggregation techniques in improving network connectivity and on the cost incurred in getting the extra information needed to build and maintain group structures. In the final part of the paper, we provide simulation results which further validate our discussion and highlight additional aspects that are to be considered in real scenarios. Our work is a first step in the investigation of the effectiveness of in‐network aggregation of terminals equipped with multiple radio technologies. The results derived in the paper are encouraging and motivate further research on the topic. Copyright © 2007 John Wiley & Sons, Ltd.
Forest edge creates small‐scale variation in reproductive rate of sika deer
Authors: Miyashita Tadashi , Suzuki Maki , Ando Daisuke , Fujita Go , Ochiai Keiji , Asada Masahiko
Published: December 2007

Habitat edges are considered to have an important role in determining the abundance of deer in forest landscapes, but to our knowledge there are few lines of evidence indicating that forest edge enhances the vital rate of deer. We examined pregnancy of female sika deer in Boso peninsula, central Japan, and explored how forest edges, food availability in forests, and local population density influence the pregnancy rate of sika deer. Local deer density was estimated by the number of fecal pellets, and food availability in forests was estimated by combining GIS data of vegetation distribution and the relationship between vegetation biomass and local deer density. Forest edge length was also determined by GIS data. Model selection was performed with multiple logistic regression analyses using the AIC to find the best model for accounting for the observed variation in pregnancy rates of the deer. Multiple logistic regression analysis showed that the length of forest edge had a positive effect on the pregnancy rate of females, whereas food availability in forests and local deer density had little effect. This forest edge effect was detected in a 100–200‐m radius from deer captured locations, indicating that deer pregnancy is primarily determined by habitat quality within a 10‐ha area. This result was confirmed by tracking females with GPS telemetry, which found that the core areas of the home range were less than 12 ha. The positive effect of edges and the lack of density dependence could be a result of high plant productivity in open environments that produces forages not depleted by high deer densities. Our results support the view that land management is the cause of the current problem of deer overabundance.