bluuebunny/crossref_metadata_2025 huggingface dataset:
Host–parasite distribution patterns under simulated climate: implications for tick‐borne diseases
Authors: Olwoch J. M. , Reyers B. , van Jaarsveld A. S.
Published: December 2008

Ticks are known to depend intimately on both climate and the presence of suitable animal host populations for reproduction, survival and population establishment. In response to the reported probable impacts of climate change on ticks and tick‐borne diseases, current and future predicted distribution maps of ticks and animal species have been produced. However, there have been no known attempts to link climate change, the predicted future distribution of ticks and the vertebrates that act as hosts and/or reservoirs for ticks and tick‐borne diseases. Yet knowledge of this link provides an in‐depth understanding of the impacts of climate change on this complex system. Using a modelling approach, this paper provides the predicted change in distribution range of an economically important tick, Rhipicephalus appendiculatus and ten vertebrate species that act as its hosts. Results obtained using a predictive species model and climate variables provided by a nested regional climate model, Division of Atmospheric Area Model (DARLAM) show reduction in tick‐range and statistically significant differences between the current and future predicted ranges (probability of occurrence) for individual host species. The results also demonstrate a reduction in the range of the total host assemblage while the ranges of hosts intimately involved in East Coast fever (ECF) transmission were altered to different degrees in different areas in sub‐Saharan Africa. Increased probability of occurrences for the tick‐host assemblage was predicted in Tanzania, Angola and Mozambique. The implications of these results for future tick abundances and ECF transmission under a changing climate scenario are discussed using the Lyme disease ‘dilution effect’ model. Copyright © 2008 Royal Meteorological Society
Agroforestry as a strategy for carbon sequestration
Authors: Ramachandran Nair P. K. , Mohan Kumar B. , Nair Vimala D.
Published: December 2008

During the past three decades, agroforestry has become recognized the world over as an integrated approach to sustainable land use because of its production and environmental benefits. Its recent recognition as a greenhouse gas–mitigation strategy under the Kyoto Protocol has earned it added attention as a strategy for biological carbon (C) sequestration. The perceived potential is based on the premise that the greater efficiency of integrated systems in resource (nutrients, light, and water) capture and utilization than single‐species systems will result in greater net C sequestration. Available estimates of C‐sequestration potential of agroforestry systems are derived by combining information on the aboveground, time‐averaged C stocks and the soil C values; but they are generally not rigorous. Methodological difficulties in estimating C stock of biomass and the extent of soil C storage under varying conditions are compounded by the lack of reliable estimates of area under agroforestry. We estimate that the area currently under agroforestry worldwide is 1,023 million ha. Additionally, substantial extent of areas of unproductive crop, grass, and forest lands as well as degraded lands could be brought under agroforestry. The extent of C sequestered in any agroforestry system will depend on a number of site‐specific biological, climatic, soil, and management factors. Furthermore, the profitability of C‐sequestration projects will depend on the price of C in the international market, additional income from the sale of products such as timber, and the cost related to C monitoring. Our knowledge on these issues is unfortunately rudimentary. Until such difficulties are surmounted, the low‐cost environmental benefit of agroforestry will continue to be underappreciated and underexploited.
The effect of grassland renovation on soil mineral nitrogen and on nitrate leaching during winter
Authors: Seidel Kirsten , Kayser Manfred , Müller Jürgen , Isselstein Johannes
Published: December 2008

Renovation of grassland may increase the mineralization of organic material and leads to a high amount of mineral N in soil which can be leached in the winter period.

Soil mineral N (SMN) in autumn and calculated nitrate leaching during winter were measured after the renewal of 8 y–old cut grassland on a sandy soil in NW Germany in 1999 to 2002. Several factors, which may influence the intensity of N mineralization, were investigated in the 2 years following renewal: the season of renovation (spring or late summer/early autumn), the technique (rotary cultivator or direct drilling), and the amount of N fertilization (0 or 320 kg N ha–1 y–1 in the 7 years before the renovation). Calculated nitrate‐N leaching losses during winter were significantly higher following renewal in early autumn (36–64 kg N ha–1) compared to renewal in spring (1–7 kg N ha–1). This effect was only significant in the first, not in the second winter after renovation. The renovation technique had a significant effect on the nitrate‐N leaching losses only in the first year after the renovation. Direct drilling led to higher leaching losses (35 kg N ha–1) than the use of a rotary cultivator (30 kg N ha–1) in the same year. Calculated nitrate losses (on average over 60 kg N ha–1) were highest after renewal of N‐fertilized grassland in late summer/early autumn. To minimize N leaching losses, it would be more effective to plan grassland renewal in spring rather than in late summer/autumn. Another, however, less effective option is to reduce N fertilization before a renovation in autumn.
Response to chemotherapy predicts survival following resection of hepatic colo‐rectal metastases in patients treated with neoadjuvant therapy
Authors: Small Risa M. , Lubezky Nir , Shmueli Einat , Figer Arie , Aderka Dan , Nakache Richard , Klausner Joseph M. , Ben‐Haim Menahem
Published: December 2008

Background

Prognosis of patients following resection of CRC metastases to the liver has traditionally been predicted by clinical risk factors. In the era of neoadjuvant chemotherapy, determination of new prognostic indicators of outcome are necessary.

Methods

This retrospective study includes patients with CRC liver metastases, who received oxaliplatin or irinotecan based neoadjuvant chemotherapy and underwent R0 resection. Patients were followed by CT and PET‐CT, before, during and after chemotherapy and surgery. The predictive value of the Memorial Sloan‐Kettering Cancer Center Clinical Score (MSKCC‐CS) and degree of response to chemotherapy (measured by CT and PET‐CT), were analyzed by univariate and multivariate COX regression.

Results

Included are 54 patients. Overall 1‐, 2‐, 3‐year survival rates 88%, 70%, and 39%. Response to chemotherapy on CT was a significant predictor of survival on univariate (P = 0.03) and multivariate analysis (P = 0.03), whereas MSKCC‐CS and response to chemotherapy on PET‐CT were not. Multivariate analysis demonstrated response to chemotherapy as a predictor of time to recurrence on CT (P = 0.02) and PET‐CT (P = 0.03), while the MSKCC‐CS (P = 0.64) was not.

Conclusions

In this cohort of patients treated by neoadjuvant chemotherapy, the outcome was not predicted by the traditional clinical scoring system, but rather by response to chemotherapy as evaluated by CT and PET‐CT. J. Surg. Oncol. 2009;99: 93–98. © 2008 Wiley‐Liss, Inc.
Managing ethics in the tourism supply chain: the case of Chinese travel to Australia
Authors: Keating Byron
Published: December 2008

The purpose of this paper was to provide clues to the industry and the academia on how best to approach the challenge of managing ethics in the tourism supply chain. To achieve this objective, the paper provided a case study of how the Australian government has responded to concerns about unethical practices in the tourism supply chain from China to Australia. A series of best practice recommendations were provided following a review of both the demand side and the supply side processes. Copyright © 2008 John Wiley & Sons, Ltd.
In vitro effects of low‐level laser irradiation for bone marrow mesenchymal stem cells: Proliferation, growth factors secretion and myogenic differentiation
Authors: Hou Jian‐feng , Zhang Hao , Yuan Xin , Li Jun , Wei Ying‐jie , Hu Sheng‐shou
Published: December 2008

Background and Objectives

Bone marrow derived mesenchymal stem cells (BMSCs) have shown to be an appealing source for cell therapy and tissue engineering. Previous studies have confirmed that the application of low‐level laser irradiation (LLLI) could affect the cellular process. However, little is known about the effects of LLLI on BMSCs. The aim of this study was designed to investigate the influence of LLLI at different energy densities on BMSCs proliferation, secretion and myogenic differentiation.

Study Design/Materials and Methods

BMSCs were harvested from rat fresh bone marrow and exposed to a 635 nm diode laser (60 mW; 0, 0.5, 1.0, 2.0, or 5.0 J/cm2). The lactate dehydrogenase (LDH) release was used to assess the cytotoxicity of LLLI at different energy densities. Cell proliferation was evaluated by using 3‐(4, 5‐dimethylithiazol‐2‐yl)‐2, 5‐diphenyl tetrazolium bromide (MTT) and 5‐bromo‐2′‐deoxyuridine (BrdU) assay. Production of vascular endothelial growth factor (VEGF) and nerve growth factor (NGF) were measured by enzyme‐linked immunosorbent assay (ELISA). Myogenic differentiation, induced by 5‐azacytidine (5‐aza), was assessed by using immunocytochemical staining for the expression of sarcomeric α‐actin and desmin.

Results

Cytotoxicity assay showed no significant difference between the non‐irradiated group and irradiated groups. LLLI significantly stimulated BMSCs proliferation and 0.5 J/cm2 was found to be an optimal energy density. VEGF and NGF were identified and LLLI at 5.0 J/cm2 significantly stimulated the secretion. After 5‐aza induction, myogenic differentiation was observed in all groups and LLLI at 5.0 J/cm2 dramatically facilitated the differentiation.

Conclusions

LLLI stimulates proliferation, increases growth factors secretion and facilitates myogenic differentiation of BMSCs. Therefore, LLLI may provide a novel approach for the preconditioning of BMSCs in vitro prior to transplantation. Lasers Surg. Med. 40:726–733, 2008. © 2008 Wiley‐Liss, Inc.
Remodeling of the rat gingiva induced by CO2 laser coagulation mode
Authors: Yamasaki Akira , Tamamura Kiyoharu , Sakurai Yuuko , Okuyama Noriko , Yusa Junko , Ito Hiroshi
Published: December 2008

Background and Objectives

This study was conducted to clarify the morphologic characteristics and subsequent repair process of coagulation necrosis produced by pulsed CO2 laser irradiation with relatively low fluence, and thereby to evaluate the clinical efficacy of this irradiation mode.

Study Design/Materials and Methods

Wounding of rat gingiva to produce coagulation necrosis was done with a CO2 laser with a fluence of 326 J/cm2. The structural characteristics of the wound and subsequent repair process were examined by means of histology, immunohistochemistry, and electron microscopy.

Results

At 6 hours after irradiation, the cells in the laser wound appeared histologically intact but had lost the immunoreactivity to antibodies against Hsp47 and exhibited various ultrastructural signs of cell death. This wound area was lined by Hsp70‐positive cells. At 1‐day post‐irradiation, the uptake of BrdU rapidly increased in the adjacent epithelium and connective tissue. The re‐epithelization commenced at 1 day and was completed by 7 days. The necrotic tissue gradually became integrated within the newly formed connective tissue and the original contour of the gingiva was retained during the repair process. The repair process of the laser‐induced wound progressed more rapidly than that of a scalpel‐made wound.

Conclusions

The present study suggests that the coagulation necrosis produced by the low fluence pulsed CO2 laser does not disturb the repair process but promotes its steady progress and subsequent tissue remodeling. This laser mode will pave the way for more conservative and minimally invasive surgery for treating a wide variety of oral soft tissue disorders. Lasers Surg. Med. 40:695–703, 2008. © 2008 Wiley‐Liss, Inc.
Mechanical tissue optical clearing devices: Enhancement of light penetration in ex vivo porcine skin and adipose tissue
Authors: Rylander Christopher G. , Milner Thomas E. , Baranov Stepan A. , Nelson J. Stuart
Published: December 2008

Background and Objective

The complex morphological structure of tissue and associated variations in the indices of refraction of components therein, provides a highly scattering medium for visible and near‐infrared wavelengths of light. Tissue optical clearing permits delivery of light deeper into tissue, potentially improving the capabilities of various light‐based therapeutic techniques, such as adipose tissue removal or reshaping.

Study Design/Materials and Methods

We report results of a study to evaluate effectiveness of novel mechanical tissue optical clearing devices (TOCD) using white light photography and infrared imaging radiometry (IIR). The TOCD consists of a pin array and vacuum pressure source applied directly to the skin surface. IIR images recorded light absorption and temperature increase of ex vivo porcine skin and adipose during laser irradiation (980 and 1,210 nm) before and after TOCD application.

Results

White light photographic images of in vivo human skin demonstrated localized compression and altered visual appearance, indicative of water and blood movement in skin. White light photographic images also showed increased visible light transport through regions of ex vivo porcine skin compressed by TOCD pins. Rate of heating in sub‐dermal adipose regions beneath TOCD pins was twofold higher following TOCD application.

Conclusions

Results of our study suggest that mechanical optical clearing may provide a means to deliver increased light fluence to dermal and adipose tissues. Lasers Surg. Med. 40:688–694, 2008. © 2008 Wiley‐Liss, Inc.
Understanding older consumers through cognitive age and the list of values: A U.K.‐based perspective
Authors: Sudbury Lynn , Simcock Peter
Published: December 2008

Although the importance of older consumers to marketers is well documented, there exists a relative paucity of U.K.‐based empirical studies into the perceptions and values of these consumers. This is the first study to investigate the relationship between age, cognitive age, and values of consumers aged between 50 and 79 years (n = 650). Results confirm that by combining cognitive age with the List of Values, much richer insights into the 50+ market can be gained. © 2008 Wiley Periodicals, Inc.
Influence of postharvest processing and storage on the content of phenolic acids and flavonoids in foods
Authors: Amarowicz Ryszard , Carle Reinhold , Dongowski Gerhard , Durazzo Alessandra , Galensa Rudolf , Kammerer Dietmar , Maiani Guiseppe , Piskula Mariusz K.
Published: December 2008

The review is based on the evaluation of electronically collated data published between 2002 to June 2006. It is based on 325 references dealing with the following subclasses of phenolic compounds: hydroxycinnamic and hydroxybenzoic acids, chalcones, flavanones, flavones, flavonols, monomeric flavanols and anthocyanins. Only publications dealing directly with the effects of storage and postharvest processing on the phenolic acid and flavonoid contents of foods were considered. The expectation that the structural diversity even within each subgroup, and the number of different procedures and of different parameters would make finding homogenous tendencies unlikely, has, in most instances, been confirmed. By adding a database Excel table combined with a focused and unified evaluation, specific additional information was rendered accessible and concise. It holds true for most of the subclasses in question that the effect of storage and food processing on the polyphenol content is negligible in comparison to the differences between different varieties of plants. Variety dependence must always be considered, for all classes of compounds.
Betulinic acid: A natural product with anticancer activity
Authors: Fulda Simone
Published: December 2008

Betulinic acid (BA) is a naturally occurring pentacyclic triterpene that exhibits a variety of biological activities including potent antitumor properties. This anticancer activity has been linked to its ability to directly trigger mitochondrial membrane permeabilization, a central event in the apoptotic process that seals the cell's fate. In contrast to the potent cytotoxicity of BA against a variety of cancer types, nonmalignant cells and normal tissue remained relatively resistant to BA, indicating a therapeutic window. Since agents that exert a direct action on mitochondria may trigger cell death under circumstances in which standard chemotherapeutics fail, there is increasing interest to develop such compounds as experimental cancer therapeutics. Thus, mitochondrion‐targeted agents such as BA hold great promise as a novel approach to bypass certain forms of drug resistance in human cancers.
Absence of glycochenodeoxycholic acid (GCDCA) in human bile is an indication of cholestasis: A 1H MRS study
Authors: Ijare Omkar B. , Bezabeh Tedros , Albiin Nils , Arnelo Urban , Bergquist Annika , Lindberg Bo , Smith Ian C.P.
Published: December 2008

The utility of 1H MR spectroscopy in detecting chronic cholestasis has been investigated. The amide proton region of the 1H MR spectrum of human bile plays a major role in differentiating cholestatic (Ch) patterns from the normal ones. Bile obtained from normal bile ducts contains both taurine and glycine conjugates of bile acids – cholic acid (CA), chenodeoxycholic acid (CDCA), and deoxycholic acid (DCA). Absence of a glycine‐conjugated bile acid glycochenodeoxycholic acid (GCDCA) has been observed in bile samples obtained from primary sclerosing cholangitis (PSC) patients. A total of 32 patients with various hepatobiliary diseases were included in the study. Twenty‐one patients had PSC and 11 had normal cholangiograms. One PSC patient was excluded from the study because of a bad spectrum. Seventeen out of the 20 PSC patients showed an absence of GCDCA in their 1H MR spectrum of bile. Six of the 11 reference patients with normal cholangiogram also showed spectra similar to those of PSC, indicating the possibility of cholestasis. DQF‐COSY and TOCSY experiments performed on bile samples from PSC patients also revealed absence of phosphatidylcholine (PC) in some of the bile samples, suggesting possible damage to the cholangiocytes by the toxic bile. These observations suggest that analysis of human bile by 1H MRS could be of value in the diagnosis of chronic Ch liver disorders. Copyright © 2008 John Wiley & Sons, Ltd.
Kinetic study of the neutral and base hydrolysis of diketene
Authors: Gómez‐Bombarelli Rafael , González‐Pérez Marina , Pérez‐Prior María Teresa , Manso José A. , Calle Emilio , Casado Julio
Published: December 2008

Diketene (4‐methylene‐2‐oxetanone) is inactive as a carcinogen, although it is more reactive toward nucleophiles than the analogs β‐propiolactone and β‐butyrolactone, both of which are alkylating agents of known carcinogenicity. In the literature the lack of carcinogenic effects has been ascribed to the rapid hydrolysis of diketene, which could preclude its in vivo alkylating capacity. In this work, the kinetics of the neutral and alkaline hydrolysis of diketene in aqueous and different water–dioxane media have been studied. The following conclusions can be drawn: (i) The neutral hydrolysis of diketene is slightly faster than that of β‐propiolactone and β‐butyrolactone. (ii) The hydrolysis reaction of diketene is very slow when compared to its alkylation reaction of a DNA‐model nucleophile, suggesting that, contrary to earlier results, competitive hydrolysis is not the cause of its lack of carcinogenicity. (iii) The diketene neutral hydrolysis rate constant increases with the water/dioxane ratio, the opposite occurring in base hydrolysis. Copyright © 2008 John Wiley & Sons, Ltd.
Evidence for a possible role of 3‐hydroxyanthranilic acid as an antioxidant
Authors: Chadha Ridhima , Mahal H. S. , Mukherjee Tulsi , Kapoor S.
Published: December 2008

The reactions of 3‐hydroxyanthranilic acid (3‐OHAA) with N3•, NO2•, NO•, CCl3O2• , and OH•radicals were examined using a pulse radiolysis technique mainly at pH 7. The bimolecular electron transfer from secondary one‐electron oxidants results in the formation of anilino radical (λmax ≅ 380 nm). The rate constant for the reaction of N3•radical with 3‐OHAA at pH 7 was found to be 6.3 × 109 dm3 mol−1 s−1. It was observed that the 3‐OHAA reacts with oxygen centered radicals. The repair rate constant for the electron transfer reaction from 3‐OHAA to guanosine radical and chlorpromazine cation radical was also examined using a pulse radiolysis technique. Kinetic studies indicate that 3‐OHAA may act as an antioxidant to repair free‐radical damage to above mentioned biologically important compounds. The rate constants of electron transfer from the 3‐OHAA to the guanosine and chlorpromazine radicals were determined. The one‐electron reduction potential for 3‐OHAA radical was found to be 0.53 ± 0.06 VversusNHE. Copyright © 2008 John Wiley & Sons, Ltd.
Tuning the conformational properties of the prion peptide
Authors: Ho Chai‐Chi , Lee Lily Y.‐L. , Huang Kuo‐Ting , Lin Chun‐Cheng , Ku Mei‐yun , Yang Chien‐Chih , Chan Sunney I. , Hsu Ruei‐Lin , Chen Rita P.‐Y.
Published: December 2008

Previously, we disclosed that O‐linked glycosylation of Ser‐132 or Ser‐135 could dramatically change the amyloidogenic property of the hamster prion peptide (sequence 108–144). This peptide, which corresponds to the flexible loop and the first β‐strand in the structure of the prion protein, is a random coil when it is initially dissolved in buffer, but amyloid fibrils are formed with time. Thus, it offers a convenient model system to observe and compare how different chemical modifications and sequence mutations alter the amyloidogenic property of the peptide within a reasonable experimental time frame. In our earlier study, aside from uncovering a site‐specificity of the glycosylation on the fibrillogenesis, different effects of α‐GalNAc and β‐GlcNAc were observed. In this work, we explore further how different sugar configurations affect the conformational property of the polypeptide chain. We compare the effects of O‐linked glycosylation by the common sugars α‐GalNAc, β‐GlcNAc with their non‐native analogs β‐GalNAc, α‐GlcNAc in an effort to uncover the origin of the sugar‐specificity on the fibril formation. We find that the anomeric configuration of the sugar is the most important factor affecting the fibrillogenesis. Sugars with the glycosidic bond in the α‐configuration at Ser‐135 have a dramatic inhibitory effect on the structural conversion of the glycosylated peptide. Because O‐glycosylation of Ser‐135 with α‐linked sugars also promote the formation of three slowly converting conformations at the site of glycosylation, we surmise that the amyloidogenic property of the peptide is related to its conformational flexibility, and the proclivity of this region of the peptide to undergo the structural conversion from the random coil to form the β‐structure. Upon O‐glycosylation with an α‐linked sugar, this conversion is inhibited and the nucleation of fibril formation is largely retarded. Consistent with this scenario, Arg‐136 is the residue most affected in the TOCSY NMR spectra of the glycosylated peptides, other than the serine site modified. In addition, when Arg‐136 is substituted by Gly, a mutation that should provide higher structural flexibility in this part of the peptide, the amyloidogenic property of the peptide is greatly enhanced, and the inhibition effect of glycosylation is largely diminished. These results are consistent with Ser‐135 and Arg‐136 being part of the kink region involved in the structural conversion. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Refining near‐native protein–protein docking decoys by local resampling and energy minimization
Authors: Liang Shide , Wang Guangce , Zhou Yaoqi
Published: December 2008

How to refine a near‐native structure to make it closer to its native conformation is an unsolved problem in protein‐structure and protein–protein complex‐structure prediction. In this article, we first test several scoring functions for selecting locally resampled near‐native protein–protein docking conformations and then propose a computationally efficient protocol for structure refinement via local resampling and energy minimization. The proposed method employs a statistical energy function based on a Distance‐scaled Ideal‐gas REference state (DFIRE) as an initial filter and an empirical energy function EMPIRE (EMpirical Protein‐InteRaction Energy) for optimization and re‐ranking. Significant improvement of final top‐1 ranked structures over initial near‐native structures is observed in the ZDOCK 2.3 decoy set for Benchmark 1.0 (74% whose global rmsd reduced by 0.5 Å or more and only 7% increased by 0.5 Å or more). Less significant improvement is observed for Benchmark 2.0 (38% versus 33%). Possible reasons are discussed. Proteins 2009. © 2008 Wiley‐Liss, Inc.
Validating census methods to measure changes in house mouse populations
Authors: Quy Roger J , Watkins Richard W , Lambert Mark S , Cowan David P
Published: December 2008

BACKGROUND: Tracking and census baiting are two techniques that are commonly advocated for monitoring the size of mouse populations. However, currently these techniques are only able to provide an index of population size, rather than an assessment of absolute numbers. In this study the authors tested the reliability of both tracking (footprints left on tiles of fixed size) and census baiting as indices of population size, and sought to calibrate levels of activity and bait consumption under both semi‐natural and field conditions (inside farm buildings).

RESULTS: Under semi‐natural conditions, census baiting produced more satisfactory population estimates than those derived from tracking activity. An initial field trial established that the optimum bait point density for this technique was 1 point per 2 m. Subsequent field trials demonstrated that the bait census technique offers a way to estimate the approximate size of stable populations of mice (population size = (mean daily bait consumption ‐ 36.3)/2.46).

CONCLUSION: The results to date are sufficiently encouraging to support the use of this cost‐effective approach to monitoring mouse numbers in the type of habitats investigated in this study. © Crown copyright 2008. Reproduced with the permission of Her Majesty's Stationery Office. Published by John Wiley & Sons, Ltd.
Electronic properties of finite‐length silicon carbide nanotubes
Authors: Alfieri G. , Kimoto T.
Published: December 2008

The electronic properties of silicon carbide nanotubes (SiCNT) as a function of length, were investigated by means of density functional theory (DFT). We found that the increasing nanotube length yields a higher localization of the lowest unoccupied and highest occupied molecular orbitals (LUMO and HOMO), thus affecting the behavior of the band gap and chemical reactivity of the SiCNTs. It is also found that structural stability increases for longer and larger nanotubes. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electroluminescence in quantum well heterostructures p‐AlxGa1–xAs/GaAs1–yPy/n‐AlxGa1–xAs under uniaxial stress
Authors: Berman Irina V. , Bogdanov Evgeniy V. , Kissel Heiko , Minina Natalia Ya. , Shirokov Stanislav S. , Yunovich Alexander E.
Published: December 2008

We present new results on the influence of uniaxial stress up to P = 4 kbar on the electroluminescence spectra and current–voltage characteristics of p‐Alx Ga1–x As/GaAs1–y Py /n‐Alx Ga1–x As double heterostructures usually used in TM emitting 808 nm high‐power diode lasers. With increasing stress, the emission spectra demonstrate a blue shift of up to 25 meV at a pressure of P = 4 kbar, while the electroluminescence intensity increases under compression. The different behavior of the current–voltage characteristics under uniaxial stress along [110] and [1$ \bar 1 $0] directions is mainly determined by the arising piezoelectric field. The results are also discussed in terms of changes in the band structure under uniaxial compression. The construction of the cryostat for optical measurements under uniaxial stress at liquid nitrogen temperature is described in the paper. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Configuration dependence of the electronic structure and optical properties of BC2N alloys
Authors: Chen Shiyou , Gong X. G. , Wei Su‐Huai
Published: December 2008

Using the first‐principles band structure and total energy method, we have studied the general trend of physical properties of the BC2N alloy as a function of atomic configurations. We found that the mechanical properties of the BC2N alloy are basically determined by the bond components: structures with more C–C and B–N bonds have low energy, high density, and high bulk and shear moduli, which validates the so called the bond counting rule. We also show that the electronic and optical properties of the BC2N alloy are more sensitive to the atomic configuration, thus could be used in future experimental measurement to identify the atomic configuration of BC2N samples. A strong internal electric field produced by the polar interfaces is observed in the long period BC2Nn ×n (111) superlattices, which explains the significant band gap decrease as the period n increases. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Comparison of the dilute bismide and nitride alloys GaAsBi and GaAsN
Authors: Mascarenhas Angelo , Kini Rajeev , Zhang Yong , France Ryan , Ptak Aaron
Published: December 2008

Dilute III–V alloys containing N or Bi share many features that are common, but some that are distinct. In GaP and GaAs, both the substituent species N and Bi behave as isoelectronic impurity traps and both lead to a giant bandgap bowing phenomenon. The isolated N and Bi impurities generate bound states in GaP but resonant states in GaAs. N impurity pairs have been observed as bound states in GaP and in GaAs whereas Bi impurity pairs have not been observed as bound states in GaP nor in GaAs. Low temperature photoluminescence studies on GaAs1–x Bix show undulations in the spectra but these are not associated with Bi–Bi pairs. Theoretical arguments for the differing behaviour of the N and Bi isolated impurities in GaAs as a function of pressure are provided. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The recovery of the shear viscosity of thermally aged bulk and ribbon glassy Pd40Cu30Ni10P20 by rapid quenching from the supercooled liquid state
Authors: Khonik V. A. , Lysenko A. V.
Published: December 2008

Isochronal (= linear heating) measurements of the shear viscosity below the glass transition of bulk and ribbon glassy Pd40Cu30Ni10P20 samples differing ∼104‐fold in the production quenching rates have been performed. It has been found that heating up into the supercooled liquid region followed by slow cooling leads to a significant structural relaxation‐induced viscosity increase upon subsequent testing. This increase, however, is not truly irreversible and the viscosity can be fully recovered (= decreased) by fast quenching from the supercooled liquid state. The effect is nearly independent of whether ribbon or bulk samples are used despite the fact that those latter are notably denser. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Anticonvulsant activities of nutmeg oil of Myristica fragrans
Authors: Wahab Abdul , Haq Rizwan Ul , Ahmed Aftab , Khan Rafeeq Alam , Raza Mohsin
Published: December 2008

The purpose of this study was to investigate the anticonvulsant activity of the volatile oil of nutmeg, the dried seed kernel of Myristica fragrans Houtt, using well‐established animal seizure models and to evaluate its potential for acute toxicity and acute neurotoxicity. The volatile oil of nutmeg (nutmeg oil) was tested for its effects in maximal electroshock, subcutaneous pentylenetetrazole, strychnine and bicuculline seizure tests. All the experiments were performed at the time of peak effect of nutmeg oil. Nutmeg oil showed a rapid onset of action and short duration of anticonvulsant effect. It was found to possess significant anticonvulsant activity against electroshock‐induced hind limb tonic extension. It exhibited dose dependent anticonvulsant activity against pentylenetetrazole‐induced tonic seizures. It delayed the onset of hind limb tonic extensor jerks induced by strychnine. It was anticonvulsant at lower doses, whereas weak proconvulsant at a higher dose against pentylenetetrazole and bicuculline induced clonic seizures. Nutmeg oil was found to possess wide therapeutic margin, as it did not induce motor impairment when tested up to 600 µL/kg in the inverted screen acute neurotoxicity test. Furthermore, the LD50 (2150 µL/kg) value was much higher than its anticonvulsant doses (50–300 µL/kg). The results indicate that nutmeg oil may be effective against grand mal and partial seizures, as it prevents seizure spread in a set of established animal models. Slight potentiation of clonic seizure activity limits its use for the treatment of myoclonic and absence seizures. Copyright © 2008 John Wiley & Sons, Ltd.
trans‐resveratrol alone and hydroxystilbenes of rhubarb (Rheum rhaponticum L.) root reduce liver damage induced by chronic ethanol administration: a comparative study in mice
Authors: Raal Ain , Pokk Paavo , Arend Andres , Aunapuu Marina , Jõgi Janne , Õkva Kai , Püssa Tõnu
Published: December 2008

The hepatoprotective effects and pharmacokinetics of trans‐resveratrol and hydroxystilbenes of the garden rhubarb (Rheum rhaponticum L., R. rhaponticum) root ethanol extract were studied.

Ethanol was administered to male BALB/c mice for 35 days in an inhalation chamber. During this time vehicle, trans‐resveratrol (20 mg/kg per day) or R. rhaponticum extract was intraperitoneally (i.p.) administered and mice were sacrificed for the collection of liver and blood. In an additional experiment, the level of parent compounds and metabolites was estimated in the blood after acute i.p. administration of trans‐resveratrol or R. rhaponticum extract. The levels of hydroxystilbenes, their metabolites and fatty acid oxy‐metabolites (oxylipins) were studied by LC‐tandem DAD‐MS/MS.

Ethanol induced hepatotoxicity, as evidenced by histological changes and accumulation of oxylipins in the blood. Both trans‐resveratrol and R. rhaponticum extract reduced the extent of these changes.

The pharmacokinetics of trans‐resveratrol was characterized by a rapid removal from the blood and metabolism to sulfates and glucuronides. After the administration of R. rhaponticum extract, in addition to trans‐resveratrol glucoside and its metabolites, several other hydroxystilbenes were found.

Inhibition of oxidation of polyunsaturated fatty acids is proposed as a basis of the hepatoprotective effect of both trans‐resveratrol and R. rhaponticum extract. Copyright © 2008 John Wiley & Sons, Ltd.
Modelling of chemical and physical aerosol properties during the ADRIEX aerosol campaign
Authors: Myhre G. , Berglen T. F. , Hoyle C. R. , Christopher S.A. , Coe H. , Crosier J. , Formenti P. , Haywood J.M. , Johnsrud M. , Jones T.A. , Loeb N. , Osborne S. , Remer L.A.
Published: December 2008

A global aerosol model with relatively high resolution is used to simulate the distribution and radiative effect of aerosols during the Aerosol Direct Radiative Impact Experiment (ADRIEX) campaign in August and September 2004. The global chemical transport model Oslo CTM2 includes detailed chemistry, which is coupled to aerosol partitioning of sulphate, nitrate and secondary organic aerosols. In accordance with aircraft observations the aerosol model simulates a dominance of secondary aerosols compared to primary aerosols in the ADRIEX study region. The model underestimates the aerosol optical depth (AOD) at 550 nm in the main region of the campaign around Venice. This underestimation mainly occurs during a 3–4 day period of highest AODs. At two AERONET (Aerosol Robotic Network) stations related to the ADRIEX campaign outside the Po valley area, the model compares very well with the observed AOD. Comparisons with observed chemical composition show that the model mainly underestimates organic carbon, with better agreement for other aerosol species. The model simulations indicate that the emission of aerosols and their precursors may be underestimated in the Po valley. Recent results show a large spread in radiative forcing due to the direct aerosol effect in global aerosol models, which is likely linked to large differences in the vertical profile of aerosols and aerosol absorption. The modelled vertical profile of aerosol compares reasonably well to the aircraft measurements as was the case in two earlier campaigns involving biomass burning and dust aerosols. The radiative effect of aerosols over the northern part of the Adriatic Sea agrees well with the mean of three satellite‐derived estimates despite large differences between the satellite‐derived data. The difference between the model and the mean of the satellite data is within 10% for the radiative effect. The radiative forcing due to anthropogenic aerosols is simulated to be negative in the ADRIEX region with values between − 5 and − 2 W m−2. Copyright © 2008 Royal Meteorological Society
Interactive data mining informs designed experiments
Authors: Gaudard Marie , Ramsey Philip , Stephens Mia
Published: December 2008

We illustrate how a Six Sigma project team can apply recursive partitioning to a historical data set to narrow down a list of potential experimental factors and then construct an experimental design using information from the partition analysis. The paper illustrates the value of analyzing historical manufacturing data to inform the choice of factors and levels for statistically designed experiments. Copyright © 2008 John Wiley & Sons, Ltd.
All orthogonal arrays with 18 runs
Authors: Schoen Eric D.
Published: December 2008

All combinatorially inequivalent orthogonal arrays with 18 runs and eight or less factors are generated. Their potential as practical experimental designs is evaluated by a classification using generalized word‐length patterns of the original arrays and those of their projections into less factors. Arrays of special interest are given explicitly. This paper includes the statistical analysis of results from a real‐life experiment based on one of the arrays. Copyright © 2008 John Wiley & Sons, Ltd.
Resource allocation for reliability of a complex system with aging components
Authors: Anderson‐Cook Christine M. , Graves Todd L. , Hamada Michael S.
Published: December 2008

To assess the reliability of a complex system, many different types of data may be available. Full‐system tests are the most direct measure of reliability, but may be prohibitively expensive or difficult to obtain. Other less direct measures, such as component or section level tests, may be cheaper to obtain and more readily available. Using a single Bayesian analysis, multiple sources of data can be combined to give component and system reliability estimates. Resource allocation looks to develop methods to predict which new data would most improve the precision of the estimate of system reliability, in order to maximally improve understanding. In this paper, we consider a relatively simple system with different types of data from the components and system. We present a methodology for assessing the relative improvement in system reliability estimation for additional data from the various types. Various metrics for comparing improvement and a response surface approach to modeling the relationship between improvement and the additional data are presented. Copyright © 2008 John Wiley & Sons, Ltd.
Lower confidence limits for process capability indices Cp and Cpk when data are autocorrelated
Authors: Lovelace Cynthia R. , Swain James J. , Zeinelabdin Hisham , Gupta Jatinder N. D.
Published: December 2008

Many organizations use a single estimate of Cp and/or Cpk for process benchmarking, without considering the sampling variability of the estimators and how that impacts the probability of meeting minimum index requirements. Lower confidence limits have previously been determined for the Cp and Cpk indices under the standard assumption of independent data, which are based on the sampling distributions of the index estimators. In this paper, lower 100(1‐α)% confidence limits for Cp and Cpk were developed for autocorrelated processes. Simulation was used to generate the empirical sampling distribution of each estimator for various combinations of sample size (n), autoregressive parameter (ϕ), true index value (Cp or Cpk), and confidence level. In addition, the minimum values of the estimators required in order to meet quality requirements with 100(1‐α)% certainty were also determined from these empirical sampling distributions. These tables may be used by practitioners to set minimum capability requirements for index estimators, rather than true values, for the autocorrelated case. The implications of these results for practitioners will be discussed. Copyright © 2008 John Wiley & Sons, Ltd.
The synthetic control chart based on two sample variances for monitoring the covariance matrix
Authors: Machado M. A. G. , Costa A. F. B. , Rahim M. A.
Published: December 2008

In this article, we propose a new statistic to control the covariance matrix of bivariate processes. This new statistic is based on the sample variances of the two quality characteristics, in short VMAX statistic. The points plotted on the chart correspond to the maximum of the values of these two variances. The reasons to consider the VMAX statistic instead of the generalized variance |S| are its faster detection of process changes and its better diagnostic feature, that is, with the VMAX statistic it is easier to identify the out‐of‐control variable. We study the synthetic chart based on the VMAX statistic. The proposed chart is always more efficient than the chart based on the generalized variance |S|. An example is presented to illustrate the application of the proposed chart. Copyright © 2008 John Wiley & Sons, Ltd.
Dispersing hash functions
Authors: Pagh Rasmus
Published: December 2008

We define a family of functions F from a domain U to a range R to be dispersing if for every set S ⊆ U of a certain size and random h ∈ F, the expected value of ∣S∣ – ∣h[S]∣ is not much larger than the expectation if h had been chosen at random from the set of all functions from U to R.

We give near‐optimal upper and lower bounds on the size of dispersing families and present several applications where using such a family can reduce the use of random bits compared to previous randomized algorithms. A close relationship between dispersing families and extractors is exhibited. This relationship provides good explicit constructions of dispersing hash functions for some parameters, but in general the explicit construction is left open. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Corrigendum: The cover time of the giant component of a random graph, Random Structures and Algorithms 32 (2008), 401–439
Authors: Cooper Colin , Frieze Alan
Published: December 2008

The above paper gives an asymptotically precise estimate of the cover time of the giant component of a sparse random graph. The proof as it stands is not tight enough, and in particular, Eq. (64) is not strong enough to prove (65). The o(1) term in (64) needs to be improved to o(1/(lnn)2) for (65) to follow. The following section, which replaces Section 3.6, amends this oversight. The notation and definitions are from the paper.

A further correction is needed. Property P2 claims that the conductance of the giant is whp, Ω(1/lnn). The proof of P2 in the appendix of the paper is not quite complete. A complete proof of Property P2 can be found in 1,2. © 2008 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Physiological responses of Microcystis aeruginosa PCC7806 to nonanoic acid stress
Authors: Shao Ji‐Hai , Wu Xing‐Qiang , Li Ren‐Hui
Published: December 2008

A recent study has shown that nonanoic acid (NA) is one of the strongest allelochemicals to a cyanobacterium Microcystis aeruginosa, but the physiological responses of M. aeruginosa to NA stress remain unknown. In this study, physiological characters such as the growth rate, photosynthetic processes, phosphorus and nitrogen uptake kinetics, and the contents of intracellular microcystin of M. aeruginosa PCC7806 were studied under the NA stress. The results showed that the growth rates of M. aeruginosa PCC 7806 were significantly inhibited in all NA stress treatments during first 3 days after exposure, and the growth rate was recovered after 5‐day exposure. After 2‐day exposure, the contents of both phycocyanin and allophycocyanin per cell decreased at NA concentration of 4 mg L−1, and oxygen evolution was inhibited even at the concentration of 0.5 mg L−1, but carotenoid content per cell was slightly boosted in NA stress. Physiological recovery of M. aeruginosa PCC7806 was observed after 7‐day exposure to NA. It was shown that NA stress had no effect on uptake of nitrogen, but could stimulate the uptake of phosphorus. The contents of intracellular microcystin have not been affected in all NA treatments in contrast with the control. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009.
Sestamibi SPECT Intensity Scoring System in Sporadic Primary Hyperparathyroidism
Authors: Yip Linwah , Pryma Daniel A. , Yim John H. , Carty Sally E. , Ogilvie Jennifer B.
Published: December 2008

Background

Most cases of sporadic primary hyperparathyroidism (PHP) are due to a single parathyroid adenoma and can be treated with minimally invasive parathyroid exploration guided by sestamibi SPECT imaging and intraoperative parathyroid hormone monitoring. Successful surgery depends on identification of the 10–15% of patients with multiglandular disease. Failed initial parathyroid exploration is both costly and morbid. We examined whether a sestamibi SPECT scoring system could predict anatomic findings in patients with PHP.

Methods

Prospective data from 1,061 consecutive patients undergoing initial parathyroid exploration for PHP from March 6, 2000 to September 28, 2007 were reviewed. One nuclear medicine physician performed independent blinded review of 577 available dual time‐point sestamibi SPECT scans, and scored the results into 1 of 5 categories: 0—negative, 1—possible, 2—probable, 3—definite adenoma, or 4—multiglandular disease. Intraoperative findings and outcomes at >5 months follow‐up were examined. Chi‐square and nonparametric analyses were used to evaluate variables for correlation.

Results

Among patients with sestamibi SPECT scan results classified as either 0—negative or 1—possible adenoma, only 211/262 (81%) had a single adenoma, compared to 263/288 (91%) patients with scan results classified as 2—probable or 3—definite adenoma (p < 0.001). Positive predictive values increased in stepwise correlation with sestamibi SPECT image intensity: 1—possible 78.5%, 2—probable 94.3%, and 3—definite adenoma 98.8%. Multiglandular disease was present in 31/144 (22%) patients with a 0—negative scan versus 13/166 (8%) patients with a 3—definite adenoma scan (p = 0.0005). Only 7/27 (26%) patients with scans classified as 4—multiglandular had actual multiglandular disease. Negative scan results were associated with a greater risk of operative failure (p < 0.001).

Conclusions

A simple scoring system based on sestamibi SPECT intensity can predict the likelihood of single adenoma in PHP. Even the best localizing study cannot exclude multiglandular disease preoperatively. Negative sestamibi SPECT scans are associated with a higher rate of operative failure. Because sestamibi SPECT scans of any category do not reliably identify multiglandular disease, expert surgeons must use validated adjuncts to avoid operative failure.