bluuebunny/crossref_metadata_2025 huggingface dataset:
Robust designs for misspecified exponential regression models
Authors: Xu Xiaojian
Published: April 2009

We consider the construction of designs for exponential regression. The response function is an only approximately known function of a specified exponential function. As well, we allow for variance heterogeneity. We find minimax designs and corresponding optimal regression weights in the context of the following problems: (1) for nonlinear least‐squares (LS) estimation with homoscedasticity, determine a design to minimize the maximum value of the integrated mean‐squared error (IMSE), with the maximum being evaluated for the possible departures from the response function; (2) for nonlinear LS estimation with heteroscedasticity, determine a design to minimize the maximum value of IMSE, with the maximum being evaluated over both types of departures; (3) for nonlinear weighted LS estimation, determine both weights and a design to minimize the maximum IMSE; and (4) choose weights and design points to minimize the maximum IMSE, subject to a side condition of unbiasedness. Solutions to (1)–(4) are given in complete generality. Copyright © 2009 John Wiley & Sons, Ltd.
Sequential design in quality control and validation of land cover databases
Authors: Carfagna Elisabetta , Marzialetti Johnny
Published: April 2009

We have faced the problem of evaluating the quality of land cover databases produced through photo‐interpretation of remote‐sensing data according to a legend of land cover types. First, we have considered the quality control, that is, the comparison of a land cover database with the result of the photo‐interpretation made by a more expert photo‐interpreter, on a sample of the polygons. Then we have analysed the problem of validation, that is, the check of the photo‐interpretation through a ground survey.

We have used the percentage of area correctly photo‐interpreted as a quality measure. Since the kind of land cover type and the size of the polygons affect the probability of making mistakes in the photo‐interpretation, we stratify the polygons according to two variables: the land cover type of the photo‐interpretation and the size of the polygons.

We have proposed an adaptive sequential procedure with permanent random numbers in which the sample size per stratum is dependent on the previously selected units but the sample selection is not, and the stopping rule is not based on the estimates of the quality parameter. We have proved that this quality control and validation procedure allows unbiased and efficient estimates of the quality parameters and allows reaching high precision of estimates with the smallest sample size. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis of Enantiomerically Pure Highly Functionalized Furanoid Glycal and 2,5‐Dihydrofuran Building Blocks
Authors: Pal Pinki , Kumar Brijesh , Shaw Arun K.
Published: April 2009

Differently protected enantiomerically pure furanoid glycals (5a–d) and highly functionalized 2,5‐dihydrofurans (6a–b) were synthesized from their respective 2,3,4‐trisubstituted tetrahydrofurans. These furanoid glycals were identified as1,4‐anhydro‐2‐deoxy‐5,6‐O‐isopropylidene‐3‐O‐benzyl‐L‐arabino‐hex‐1‐enitol, 1,4‐anhydro‐2‐deoxy‐5,6‐O‐isopropylidene‐3‐O‐benzyl‐L‐ribo‐hex‐1‐enitol, 1,4‐anhydro‐2‐deoxy‐5,6‐O‐isopropylidene‐3‐O‐benzyl‐D‐ribo‐hex‐1‐enitol and 1,4‐anhydro‐2‐deoxy‐5,6‐O‐isopropylidene‐3‐O‐benzyl‐D‐arabino‐hex‐1‐enitol, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Pyridine‐based PBI Composite Membranes for PEMFCs
Authors: Quartarone E. , Magistris A. , Mustarelli P. , Grandi S. , Carollo A. , Zukowska G.Z. , Garbarczyk J. E. , Nowinski J. L. , Gerbaldi C. , Bodoardo S.
Published: April 2009

Polybenzimidazole (PBI) activated with H3PO4 is one of the membranes of choice to replace Nafion® in PEMFCs in order to allow their use above 100 °C. The limits of PBI in terms of acid leaching and low conductivity below 160 °C can be overcome by a proper monomer tailoring, and by the addition of new fillers. Here, we report on new pyridine‐based PBI membranes with: (i) imidazole‐silica (SiO2‐Im) and (ii) mesostructured silica (SBA‐15) fillers. Both the thermal stability and the permanent conductivity are improved by adding 5 wt.‐% of filler, but SiO2‐Im gives the best results. Permanent conductivity values higher than 10–3 S cm–1 are obtained at 120 °C and 50% R.H. Vibrational spectroscopies (FT‐IR and Raman) are used to investigate the relationships among the polymer, the filler and the activating H3PO4 acid.
Perception of head and neck cancer quality of life within the medical world: A multicultural study
Authors: Demez Pierre H. , Moreau Pierre R.
Published: April 2009

Background

Physician's perception of quality of life of patients with cancer is unclear. No reports have evaluated its influence on patient management.

Methods

Five hundred otolaryngologists completed a questionnaire regarding the quality of life of patients with head and neck cancer.

Results

Seventy‐eight percent of responders thought that quality of life must be considered when choosing treatment, even if this meant decreased survival. Seventy‐five percent thought it justified to withhold curative treatment if this would lead to impaired quality of life. Pain and breathing were the most important symptoms to consider. The perception was worse for physicians practicing in Latin culture, working in private practice, or with no personal acquaintance with a head and neck cancer victim and was better after radiotherapy than after surgery and chemotherapy.

Conclusion

Quality of life is important for physicians and is considered as essential as survival by many physicians. The perception of patient's quality of life influences the treatment choice. © 2009 Wiley Periodicals, Inc. Head Neck, 2009
Role of vitamin D deficiency in continued hyperparathyroidism following parathyroidectomy
Authors: Redman Carolyn , Bodenner Donald , Stack Brendan
Published: April 2009

Background

The aim of this study was to investigate vitamin D deficiency as an etiology for patients with elevated parathormone (PTH) levels after parathyroidectomy.

Methods

Fifity‐five patients were identified who had undergone parathyroidectomy between January 2003 and November 2006 with complete records that included measurements of preoperative and postoperative PTH, vitamin D, calcium, ionized calcium, and sestamibi localization results.

Results

Thirteen patients (24%) had elevated PTH at 1 week postoperatively. Sixty‐two percent of these patients (N = 8, 15% overall) had vitamin D deficiency. Thirty‐one percent (N = 4, 7% overall) had persistent biochemical evidence of primary hyperparathyroidism. Three of the 4 had a subsequent positive sestamibi parathyroid localization of an additional adenoma (5.5% series incidence of double adenomas).

Conclusion

Given the known prevalence of vitamin D deficiency, consideration should be given to preoperative vitamin D testing to avoid confusion about the etiology of persistently elevated PTH following surgery. © 2009 Wiley Periodicals, Inc. Head Neck, 2009
E1B 55‐kDa deleted, Ad5/F35 fiber chimeric adenovirus, a potential oncolytic agent for B‐lymphocytic malignancies
Authors: Wang Guohua , Li Gongchu , Liu Hui , Yang Chunmei , Yang Xiudi , Jin Jie , Liu Xinyuan , Qian Qijun , Qian Wenbin
Published: April 2009

Background

Conditionally replicative adenovirus (CRAd) provides a promising strategy for solid tumor therapy. However, relatively few studies have been addressed on hematopoietic malignancies. We previously found that ZD55, a serotype 5 (Ad5)‐based, E1B 55‐kDa deleted CRAd, inhibited leukemic cell growth and induced apoptosis. In the present study, we employed SG235, a new CRAd with both an E1B 55‐kDa deletion and an Ad5/F35 chimeric fiber, for the treatment of B‐cell tumors.

Methods

CRAd SG235 was engineered not to express adenovirus E1B 55‐kDa gene, and the wild‐type Ad5 fiber was replaced by a chimeric Ad5/35 fiber containing an Ad5 tail, an Ad35 shaft and an Ad35 knob. Using in vitro and in vivo experiments, the infectivity and selective cytotoxicity of SG235 on B‐cell tumor lines were evaluated. Apoptosis‐related signaling elements were investigated.

Results

SG235 significantly suppressed malignant B‐cell growth in vitro and in vivo. In addition to selective cytolysis, SG235‐induced apoptosis in the tumor cells. Upon SG235 infection, levels of cleaved forms of caspase‐3 and poly(adenosine diphosphate‐ribose) polymerase increased, suggesting that SG235 induces apoptosis in malignant B‐cells by activating a caspase cascade. Furthermore, SG235 infection resulted in an up‐regulated level of Bax, as well as down‐regulated levels of xIAP, cIAP and survivin, suggesting that infection of SG235 induces apoptosis in B‐cell tumor lines by affecting both apoptosis‐promoting and ‐inhibiting intracellular signaling elements.

Conclusions

CRAd SG235 may serve as a potential anticancer agent, or a therapeutic vehicle for harboring anticancer genes, in B‐cell tumor treatment. Copyright © 2009 John Wiley & Sons, Ltd.
A novel locus for adolescent idiopathic scoliosis on chromosome 12p
Authors: Raggio Cathleen L. , Giampietro Philip F. , Dobrin Seth , Zhao Chengfeng , Dorshorst Donna , Ghebranious Nader , Weber James L. , Blank Robert D.
Published: April 2009

Adolescent idiopathic scoliosis (AIS) is a common disorder with strong evidence for genetic predisposition. Quantitative trait loci (QTLs) for AIS susceptibility have been identified on chromosomes. We performed a genome‐wide genetic linkage scan in seven multiplex families using 400 marker loci with a mean spacing of 8.6 cM. We used Genehunter Plus to generate linkage statistics, expressed as homogeneity (HLOD) scores, under dominant and recessive genetic models. We found a significant linkage signal on chromosome 12p, whose support interval extends from near 12pter, spanning approximately 10 million bases or 31 cM. Fine mapping within the region using 20 additional markers reveals maximum HLOD = 3.7 at 5 cM under a dominant inheritance model, and a split peak maximum HLOD = 3.2 at 8 and 18 cM under a recessive inheritance model. The linkage support interval contains 95 known genes. We found evidence suggestive of linkage on chromosomes 1, 6, 7, 8, and 14. This study is the first to find evidence of an AIS susceptibility locus on chromosome 12. Detection of AIS susceptibility QTLs on multiple chromosomes in this and other studies demonstrate that the condition is genetically heterogeneous. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:1366–1372, 2009
Imaging of chemical and physical state of individual cellular lipid droplets using multiplex CARS microscopy
Authors: Bonn Mischa , Müller Michiel , Rinia Hilde A. , Burger Koert N.J.
Published: April 2009

Cellular lipid droplets are organelles that carry out important functions such as the regulated storage and release of cholesterol and fatty acids (FAs). Lipid droplets therefore play a key role in both healthy metabolism and metabolic disorders such as obesity, type II diabetes, and atherosclerosis. Hence, there has been much interest in understanding the chemical (lipid) composition and physical state (lipid packing) of lipid droplets. Coherent anti‐Stokes Raman Scattering (CARS) microscopy has proven to be a useful tool in lipid droplet research because of its ability to visualize lipid droplets in a label‐free manner. Multiplex CARS microscopy in spectroscopy mode has been particularly useful: In conjunction with appropriate spectral processing, it allows one to obtain the local Raman response with submicron spatial resolution. Thus, multiplex CARS microscopy provides rapid quantitative information and allows quantitative imaging of the chemistry (level of acyl unsaturation) and physical state (acyl chain order) of individual lipid droplets. We discuss the different vibrational markers that may be used to characterize the lipid droplet properties and demonstrate that while the CH stretch of unsaturated CH groups is a useful marker of the level of acyl unsaturationin vitro, it failsin vivo. Moreover, we present here results on two different cell lines—adipocytes and HeLa cells—with distinct lipid droplet characteristics, both in terms of lipid droplet size and dependence of the lipid droplet composition on the incubation medium. Copyright © 2009 John Wiley & Sons, Ltd.
Structural characterization of Lu0.7Y0.3AlO3 single crystal by Raman spectroscopy
Authors: Casu Alberto , Ricci Pier Carlo , Anedda Alberto
Published: April 2009

Lutetium yttrium orthoaluminate perovskite [Lu0.7Y0.3AlO3 (LuYAP)] crystals show great potential as fast response and high‐efficiency scintillators as an alternative to LuAlO3 (LuAP) crystals. This paper aims to offer a complete analysis of the vibrational modes of the LuYAP crystal by means of polarized Raman spectroscopy in the temperature range of 20–290 K and confronting the experimental results with numerical methods in order to characterize the crystal structure. Furthermore, an interpretation of the data in terms of vibrating molecular structures is suggested and the results are successfully confronted with the vibrational modes of similar perovskite crystals. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and Characterization of Amphiphilic Polyethers Based on Tetrahydrofuran and Glycidol: Antibacterial Assessment
Authors: Theiler Stefan , Hövetborn Thomas , Keul Helmut , Möller Martin
Published: April 2009

Starting from THF and protected glycidols, linear multifunctional polyethers were prepared. Random copolymers were synthesized via cationic ROP while block copolymers were obtained via anionic ROP. Kinetic studies were carried out for the random copolymers. Poly(THF‐co‐glycidol) was converted in polymer‐analogous reactions first to phenoxy‐carbonyloxy‐methyl‐substituted polyethers and then to amphiphilic polyethers by conversion of the former substituted polyethers with different functional amines. The resulting amphiphilic polyesters were tested for their bacteriostatic effect.

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Simulation of Agglomerate Dispersion in Cubic Cavity Flow
Authors: Hosseini Mahdi Salami , Nazockdast Hossein , Anderson Patrick D. , Meijer Han E. H.
Published: April 2009

Agglomerate dispersion and deformation is simulated and studied in a cavity flow, as a typical three‐dimensional flow field, using Stokesian dynamics and macroscopic flow analysis. The break‐up and deformation behaviors of two different agglomerate structures – loose, with fractal dimension FD = 1.8, and dense, with FD = 2.6 – are examined in different flow paths. The interparticle forces are calculated using van der Waals and Born forces. Results show that agglomerates with a dense structure break‐up through detachment, while ones with a loose structure deform and break into fragments through rupture. It was also found that the rearrangement of particles in the agglomerate can postpone break‐up in flow fields where rotation occurs, since it can dissipate stress through rearrangements.

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Analysis for the identification of an unknown diffusion coefficient via semigroup approach
Authors: Demir Ali , Ozbilge Ebru
Published: April 2009

This paper presents a semigroup approach for the mathematical analysis of the inverse coefficient problems of identifying the unknown coefficient k(ux) in the inhomogenenous quasi‐linear parabolic equation ut(x, t)=(k(ux)ux(x, t))x +F(u), with the Dirichlet boundary conditions u(0, t)=ψ0, u(1, t)=ψ1 and source function F(u). The main purpose of this paper is to investigate the distinguishability of the input–output mappings Φ[·]:𝒦→C1[0, T], Ψ[·]:𝒦→C1[0, T] via semigroup theory. Copyright © 2009 John Wiley & Sons, Ltd.
Schadstoffe in Spielwaren
Authors: Pfalzgraf Andreas , Wolter Jörg , Pötter Kristina
Published: April 2009

In Europa sind Spielzeuge mit gesundheitsschädlichen Stoffen verboten. Die Substanzen sind aber eindeutig nachzuweisen und zu bewerten. Nach über zwanzig Jahren CE‐Kennzeichnung für Spielzeuge stehen die Versuche, Kriterien und Vorgehensweise zu konkretisieren, noch immer am Anfang.
Die chemischen Gesellschaften im Dritten Reich
Authors: Maier Helmut
Published: April 2009

Erste Ergebnisse des Projektes zur Geschichte der GDCh‐Vorläuferorganisationen im Nationalsozialismus.
Novel splice site mutations in the gamma glutamyl carboxylase gene in a child with congenital combined deficiency of the vitamin K‐dependent coagulation factors (VKCFD)
Authors: Titapiwatanakun Ruetima , Rodriguez Vilmarie , Middha Sumit , Dukek Brian A. , Pruthi Rajiv K.
Published: April 2009

Congenital combined deficiency of the vitamin K‐dependent coagulation factors is a rare bleeding disorder caused by either a defect in the γ‐glutamyl carboxylase or the vitamin K epoxide reductase enzyme complex. The diagnosis should be considered when vitamin‐K dependent factor activities are decreased and liver dysfunction, vitamin K deficiency, and factitious coumarin ingestion have been excluded. We report a case of VKCFD in a child resulting from compound heterozygosity for two novel splice site mutations of the γ‐glutamyl carboxylase gene. Oral vitamin K supplementation resulted in partial resolution of proteins and complete resolution of bleeding. Pediatr Blood Cancer 2009;53:92–95. © 2009 Wiley‐Liss, Inc.
Characterization of chromate conversion film on tinplate substrate by XPS and electrochemistry methods
Authors: Sun J. , Qi G. C. , Tan Y. , An C. Q.
Published: April 2009

The chromate conversion coating formed on commercial tinplate via a cathode electrolytic dichromate treatment has been studied by X‐ray photoelectron spectroscopy (XPS) and electrochemistry methods. Through the analysis of the XPS, it was shown that there existed Cr, O, and Sn in the chromate coating and the chromate film consisted mainly of Cr(OH)3, Cr2O3, Sn, and SnOx. The current density decreased with increasing of the electric charge. The corrosion resistance for tinplate is relative with the content of chromium in the passivation film. Copyright © 2009 John Wiley & Sons, Ltd.
Generalized ROC curve inference for a biomarker subject to a limit of detection and measurement error
Authors: Perkins Neil J. , Schisterman Enrique F. , Vexler Albert
Published: April 2009

The receiver operating characteristic (ROC) curve is a tool commonly used to evaluate biomarker utility in clinical diagnosis of disease, especially during biomarker development research. Emerging biomarkers are often measured with random measurement error and subject to limits of detection that hinder their potential utility or mask an ability to discriminate by negatively biasing the estimates of ROC curves and subsequent area under the curve. Methods have been developed to correct the ROC curve for each of these types of sources of bias but here we develop a method by which the ROC curve is corrected for both simultaneously through replicate measures and maximum likelihood. Our method is evaluated via simulation study and applied to two potential discriminators of women with and without preeclampsia. Published in 2009 by John Wiley & Sons, Ltd.
Accessory sex glands of male mice have the ability to synthesize taurinevia the cysteine sulfinate decarboxylase pathway
Authors: Fan Jing Jing , Zhou Jin Lian , Li Jian Hua , Cui Sheng
Published: April 2009

Our previous study showed that cysteine sulfinate decarboxylase (CSD) is expressed in the testis, epididymis, and ductus deferens. However, the expression of CSD and taurine concentration in the male accessory sex glands remain unknown. Therefore, we conducted immunohistochemical analysis, semi‐quantitative reverse transcription polymerase chain reaction (RT‐PCR), and western blotting in order to examine CSD expression in the seminal vesicle; bulbourethral gland; and prostate gland, including the dorsolateral prostate, ventral prostate, and anterior prostate. We also analyzed the tissue taurine concentration by using high‐performance liquid chromatography (HPLC). Immunohistochemical analysis revealed that CSD is expressed in the tall columnar cells of the seminal vesicle, the glandular epithelium of the bulbourethral gland, and the epithelial cells of the intermediate segments of prostate gland. The taurine concentrations in the dorsolateral prostate, ventral prostate, and anterior prostate; seminal vesicle; and bulbourethral gland in terms of micromoles per gram wet weight were 6.09 ± 0.67, 6.62 ± 0.43, 4.14 ± 0.05, 12.55 ± 1.03, and 7.50 ± 0.64, respectively; these values are similar to the relative expression levels of the CSD protein. These results demonstrate that CSD is expressed in the accessory sex glands of mice, and they confirm our hypothesis that male accessory sex glands are able to synthesize taurine through the CSD pathway.
Ring formation in electromagnetic beams propagating in a magnetoplasma
Authors: MISRA SHIKHA , MISHRA S. K.
Published: April 2009

This paper presents an analysis (in the paraxial approximation) of a self-consistent, steady-state, theoretical model, which explains the ring formation in a Gaussian electromagnetic beam propagating in a magnetoplasma, characterized by ponderomotive and collisional nonlinearities. The condition for the formation of a dark and a bright ring has been derived analytically and the focusing/defocusing of the beam has been investigated in the different regimes. Further, the effect of the magnetic field and the nature of the nonlinearity on the ring formation and self focusing of the beam have also been explored.
Slope orientation enhances the nurse effect of a paramo shrub,Hypericum irazuense(Hypericaceae) in Costa Rica
Authors: Farji-Brener Alejandro G. , Chinchilla Federico A. , Magrach Ainhoa , Romero Víctor , Ríos Marcos , Velilla Marianela , Serrano José Manuel , Amador-Vargas Sabrina
Published: April 2009

The nurse effect is a positive interaction in which one plant (the nurse) provides conditions that enhance the establishment and growth of another plant species (Callaway 1995). Increased environmental severity appeared to increase the strength of nurse effects (Brookeret al. 2008, Lortie & Callaway 2006). On the one hand, the impact of the nurse effect depends on the magnitude of the environmental changes exerted by the nurse plant. On the other hand, the impact could depend on the number of plant species in the regional pool that respond to such changes. For example, better conditions beneath the crowns of nurse plants might allow the occurrence of species that are sensitive to environmental stress and that occur infrequently in open areas. Thus, if a nurse plant modulates environmental conditions that are critical for the persistence of other plant species, it seems likely that such nurse plants would have greater effects in stressful habitats, where they cause relatively larger environmental mitigation (Badanoet al. 2006, Callawayet al. 2002).
Microclimatic patterns correlate with the distribution of epiphyllous bryophytes in a tropical lowland rain forest in Costa Rica
Authors: Sonnleitner Michaela , Dullinger Stefan , Wanek Wolfgang , Zechmeister Harald
Published: April 2009

Quantitative analyses of the factors driving the distribution of bryophytes in the phyllosphere of tropical rain forests are rare. In this study we sampled epiphyllous bryophytes on two leaves of each of 57 individuals belonging to four phorophyte species (Asplundia pittieri, Carludovica drudei, Costus laevis and Dieffenbachia concinna) at three adjacent, but microclimatically varied sites in the Esquinas forest, Costa Rica. Microclimatic parameters and phorophyte identities were correlated to differences in cover, diversity and species composition of bryophyte assemblages by means of Kruskal–Wallis tests, non-metric multidimensional scaling and indicator species analysis. High relative humidity and in particular daily fluctuations in relative humidity proved to be the most important factors for epiphyll distribution suggesting severe constraints of epiphyll colonisation by pronounced humidity fluctuations. Differences in air temperature and light availability as well as phorophyte identity were only weakly correlated with bryophyte cover and diversity. However, species composition of epiphyllous assemblages was related to all microclimatic variables as well as to phorophyte identity. The strong response of epiphyllous bryophytes to even subtle microclimatic variations suggests that undisturbed forest canopies and their control on microclimate may be essential for the development of epiphyll communities.
Bed and flow dynamics leading to sediment‐wave initiation
Authors: Coleman S. E. , Nikora V. I.
Published: April 2009

New PIV‐based experiments show that the nascent seed waves from which both ripples and dunes develop are generated on planar mobile sediment beds in a two‐stage process. The first stage comprises the motion of random sediment patches that reflect the passage of sediment‐transport events caused by attached eddies. These eddy‐transport events propagate at speeds that are proportional to their size and less than overhead eddy convection velocities, but potentially larger than local average fluid and sediment velocities. In the second stage, interactions of the moving patches result in a bed disturbance that exceeds a critical height and interrupts the bed‐load layer. Quasi‐regular seed waves are then generated successively downstream of this stabilised growing disturbance via a scour‐deposition wave that arises from the requirement of sediment mass conservation and the sediment‐transport and bed‐stress distributions downstream of a bed perturbation. Seed waves are thereby of preferred lengths that scale with the grain size, i.e. length = O(130) grain diameters, agreeing with compiled measurements. This two‐stage generation mechanism is valid for fully‐turbulent hydraulically‐smooth and rough‐bed flows of small to large sediment transport rates. It is furthermore valid for laminar flows, although the critical disturbances leading to seed‐wave generation arise through bed discontinuities, and not eddy‐based sediment‐transport events. The identified generation mechanism, which accounts for turbulence effects, explains the observed similar scaling of alluvial, closed‐conduit and lightweight‐sediment seed waves. The present measurements highlight further aspects of the flow dynamics preceding seed‐wave generation, including: decreases in von Kármán's constant due to bed mobility, near‐bed eddy convection speeds in excess of local double‐averaged (in time and space) streamwise velocities, and the validity of the four‐range spectral scaling model for open‐channel flows proposed earlier by Nikora.
Shortwave versus longwave direct radiative forcing by Taklimakan dust aerosols
Authors: Xia Xiangao , Zong Xuemei
Published: April 2009

Six Mays from 2001 to 2006 of aerosol optical depth from the Multiangle Imaging SpectroRadiometer and short‐ and longwave flux from the Clouds and Earth's Radiant Energy Budget Scanner are combined to estimate radiative forcing of dust aerosols in the Taklimakan Desert (75°E–95°E, 36°N–42°N, elevation < 1600 m). The cloud‐free dust shortwave versus longwave forcing per aerosol optical depth at about 05:00 UTC are −48.1 and 28.4 W m−2, respectively. Dust longwave warming offsets 58% of dust shortwave cooling and the overall dust radiative effect is to cool the Earth system. Annual shortwave and longwave forcing efficiencies vary from 26.7 to 63.8 and 18.3 to 39.3 W m−2, respectively, due to changes in surface properties. Radiative transfer model simulations also suggest Earth's system is cooled in the shortwave but warmed in the longwave by Taklimakan dust aerosols.
Hypotheses on the functional roles of chaotic transitory dynamics
Authors: Tsuda Ichiro
Published: April 2009

In contrast to the conventional static view of the brain, recent experimental data show that an alternative view is necessary for an appropriate interpretation of its function. Some selected problems concerning the cortical transitory dynamics are discussed. For the first time, we propose five scenarios for the appearance of chaotic itinerancy, which provides typical transitory dynamics. Second, we describe the transitory behaviors that have been observed in human and animal brains. Finally, we propose nine hypotheses on the functional roles of such dynamics, focusing on the dynamics embedded in data and the dynamical interpretation of brain activity within the framework of cerebral hermeneutics.
Antiferromagnetic iridium-manganese intermediate layers for perpendicular recording media (invited)
Authors: Srinivasan Kumar , Piramanayagam S. N. , Sbiaa Rachid , Kay Yew Seng , Tan Hang Khume , Wong Seng Kai
Published: April 2009

Current generation of cobalt-oxide-based perpendicular magnetic recording media uses single or dual ruthenium intermediate layers in order to grow crystallographically textured, and magnetically isolated granular media. In this work, the potential advantages of an antiferromagnetic iridium-manganese intermediate layer directly under the recording layer are highlighted. Owing to its close lattice matching with hexagonal cobalt, iridium-manganese which has the L12, or AuCu3-type crystal structure, can support the heteroepitaxial growth of the cobalt-based recording layer. In one of the media schemes described here, (111) textured iridium-manganese thin film was grown on 7.5 nm thick ruthenium layer. On the iridium-manganese as segregation layer, the Co-oxide-based magnetic recording layer showed perpendicular texture with Δθ50 below 4°, coercivity of over 4000 Oe alongside magnetic exchange decoupling, average grain sizes of 6 nm with distributions under 14%, and improved thermal stability. Measurements of the anisotropy constant did not show any significant change and even an IrMn capping layer was observed to improve the thermal stability. The possible mechanisms through which the IrMn layer could affect the thermal stability are hypothesized. The initial layers of the magnetic recording layer on IrMn segregation layers also showed exchange-decoupled and segregated grains, which is unlike that observed on Ru segregation layers. In a second media scheme, (111) textured iridium-manganese thin film was grown on a crystalline soft magnetic underlayer belonging on top of amorphous soft underlayers. In this scheme, partial pinning of the soft underlayer due to exchange-bias interaction with the IrMn layer was observed. This scheme offers the possibility to reduce the intermediate layer thickness, thus improve media writability, and with further optimization, could potentially facilitate the approach toward 1 Tbits/in.2.
Detecting nonlinear oscillations in broadband signals
Authors: Vejmelka Martin , Paluš Milan
Published: April 2009

A framework for detecting nonlinear oscillatory activity in broadband time series is presented. First, a narrow-band oscillatory mode is extracted from a broadband background. Second, it is tested whether the extracted mode is significantly different from linearly filtered noise, modeled as a linear stochastic process possibly passed through a static nonlinear transformation. If a nonlinear oscillatory mode is positively detected, it can be further analyzed using nonlinear approaches such as phase synchronization analysis. For linear processes standard approaches, such as the coherence analysis, are more appropriate. The method is illustrated in a numerical example and applied to analyze experimentally obtained human electroencephalogram time series from a sleeping subject.
B activation and clustering in ion-implanted Ge
Authors: Impellizzeri G. , Mirabella S. , Bruno E. , Piro A. M. , Grimaldi M. G.
Published: April 2009

Experimental studies about electrical activation and clustering of B implanted in crystalline Ge (c-Ge) are reported. To this aim, we structurally and electrically investigated c-Ge samples implanted at different temperatures with B at 35 keV in the high-concentration dopant regime (0.67–25×1020 B/cm3). We elucidated that a high level of damage, in the form of amorphous pockets, favors the electrical activation of the dopant, and a complete activation was achieved for properly chosen implant conditions. We found, by joining channeling measurements with the electrical ones, that the reason for incomplete B activation is the formation of B-Ge complexes with a well-defined stoichiometry of 1:8. The thermal stability of the B-doped samples, up to 550 °C, was also investigated. The tested stability demonstrates that the B clustering, responsible of B inactivity, is characterized by high binding energies and higher thermal budgets are needed to make them to dissolve. These studies, besides clarify the physical mechanisms by which B dopes Ge, can be helpful for the realization of ultrashallow junctions for the future generation devices.
Bond breaking in light-induced potentials
Authors: Chang Bo Y. , Shin Seokmin , Santamaria Jesus , Sola Ignacio R.
Published: April 2009

We study the photodissociation of ICl− under moderately strong (TW/cm2) and short (below picosecond) laser pulses. Using a single resonant pump pulse, the photodissociation spectra shows two barely overlapping bands corresponding to Frank–Condon excitation and dissociation in two electronic states. By adding a nonresonant stronger control pulse we show that (1) the photodissociation bands can be blueshifted and (2) the asymptotic state of the fragments depends on the chosen pulse sequence. If the pump pulse precedes the control pulse or the control pulse straddles the pump pulse, the outgoing wave packet has components in the two dissociation channels, whereas if the control pulse precedes the pump pulse, the photodissociation proceeds selectively in a single channel.
Automated synchrogram analysis applied to heartbeat and reconstructed respiration
Authors: Hamann Claudia , Bartsch Ronny P. , Schumann Aicko Y. , Penzel Thomas , Havlin Shlomo , Kantelhardt Jan W.
Published: April 2009

Phase synchronization between two weakly coupled oscillators has been studied in chaotic systems for a long time. However, it is difficult to unambiguously detect such synchronization in experimental data from complex physiological systems. In this paper we review our study of phase synchronization between heartbeat and respiration in 150 healthy subjects during sleep using an automated procedure for screening the synchrograms. We found that this synchronization is significantly enhanced during non-rapid-eye-movement (non-REM) sleep (deep sleep and light sleep) and is reduced during REM sleep. In addition, we show that the respiration signal can be reconstructed from the heartbeat recordings in many subjects. Our reconstruction procedure, which works particularly well during non-REM sleep, allows the detection of cardiorespiratory synchronization even if only heartbeat intervals were recorded.
Noise mediated regularity of porous silicon nanostructures
Authors: Escorcia-Garcia J. , Agarwal V. , Parmananda P.
Published: April 2009

Interaction of noise with nonlinear electrochemical kinetics involving the etching of porous silicon is studied experimentally. It is realized that by monotonically increasing the level of internal noise, one can tune the regularity of the spatial distribution of pores in silicon nanostructures. This regularity of the noise provoked structures is quantified using a spatial normalized variance technique in conjunction with the calculation of Hurst exponents. Our experimental results indicate the emergence of intrinsic coherence resonance. Consequently, there exists an optimal value of internal noise for which the spatial distribution of nanopores attain maximal regularity. This regularity of the pores can be useful for enhancing the optical response of porous silicon based devices.
Introduction to Focus Issue: Nonlinear Dynamics in Cognitive and Neural Systems
Authors: Arecchi F. Tito , Kurths Jürgen
Published: April 2009

In this Focus Issue, two interrelated concepts, namely, deterministic chaos and cognitive abilities, are discussed.
The Metallicity Distribution of Distant F and G Type Stars in the CFHT Legacy Survey Deep Field
Authors: Karataş Yüksel , Kilic Mukremin , Güneş Orhan , Limboz Füsun
Published: April 2009

We study the metal abundances of F and G type stars in the Galactic disk and halo using the Canada–France–Hawaii Telescope Legacy Survey D4 field. For a sample of stars within 7 kpc of the Galactic plane, we derive mean abundance values of [Fe/H] = −0.77 ± 0.36 dex for the thick disk, and [Fe/H] = –1.42 ± 0.98 dex for the stellar halo, respectively. These metallicites are consistent with the metallicity estimates from the Sloan Digital Sky Survey Data Release 6. We do not find a vertical abundance gradient for the thick disk between 1 kpc and 4 kpc. However, stars within 1 kpc of the Galactic plane are saturated in our dataset, and therefore we cannot rule out the observed vertical metallicity gradient for the thick disk stars in the SDSS. Moreover, we find a negative trend in the halo metallicity with increasing distance from the Galactic plane. This trend could be due to a contribution from an increasing number of very metal poor stars that belong to the outer halo. However, systematic effects in photometric metallicities are largest for the most metal poor stars, and therefore these effects cannot be ruled out.
Where do we backchannel?
Authors: Kjellmer Göran
Published: April 2009

The paper investigates a sample of ‘backchannels’, a kind of response item, in the Cobuild Corpus. Its object is to chart the occurrence of backchannels in modern English speech, and especially to find out if they can indicate how much of a language sequence is needed for a listener to understand the intended message. The sequences into which backchannels are inserted and their insertion points are therefore classified, and the fairly numerous sequences where backchannels “interrupt” a linguistic unit are singled out for special study. A general conclusion is that in the cases where there is no explicit information about the part of the message following the inserted backchannel, the message will nevertheless mostly be understood even at the backchannel insertion point. A comparison between male and female speakers shows that women use backchannels more than men and that, unlike men, they prefer unemphatic backchannels.
Coping with extreme speech conditions in simultaneous interpreting
Authors: Meuleman Chris , Van Besien Fred
Published: April 2009

This study addresses the strategies used by simultaneous interpreters when confronted with syntactically complex sentences and with a high speed of delivery. The material consists of recordings of fifteen professional interpreters rendering two passages (one with a complex sentence structure, the other with a high speed of delivery) from French into Dutch. Most, but not all, interpreters managed to produce an acceptable translation. In the case of the complex passage, most interpreters opted for a segmentation strategy, while a few applied a tailing strategy. In the case of the high delivery speed, most opted for a tailing strategy, but a few applied segmentation.
A simulation study on word order bias
Authors: Gong Tao , Minett James W. , Wang William S-Y.
Published: April 2009

The majority of the extant languages have one of three dominant basic word orders: SVO, SOV or VSO. Various hypotheses have been proposed to explain this word order bias, including the existence of a universal grammar, the learnability imposed by cognitive constraints, the descent of modern languages from an ancestral protolanguage, and the constraints from functional principles. We run simulations using a multi-agent computational model to study this bias. Following a local order approach, the model simulates individual language processing mechanisms in production and comprehension. The simulation results demonstrate that the semantic structures that a language encodes can constrain the global syntax, and that local syntax can help trigger bias towards the global order SOV/SVO (or VOS/OVS).
Representations underlying social learning and cultural evolution
Authors: Bryson Joanna J.
Published: April 2009

Social learning is a source of behaviour for many species, but few use it as extensively as they seemingly could. In this article, I attempt to clarify our understanding of why this might be. I discuss the potential computational properties of social learning, then examine the phenomenon in nature through creating a taxonomy of the representations that might underly it. This is achieved by first producing a simplified taxonomy of the established forms of social learning, then describing the primitive capacities necessary to support them, and finally considering which of these capacities we actually have evidence for. I then discuss theoretical limits on cultural evolution, which include having sufficient information transmitted to support robust representations capable of supporting variation for evolution, and the need for limiting the extent of social conformity to avoid ecological fragility. Finally, I show how these arguments can inform several key scientific questions, including the uniqueness of human culture, the long lifespans of cultural species, and the propensity of animals to seemingly have knowledge about a phenomenon well before they will act upon it.
The Use of Messages in Altering Risky Gambling Behavior in College Students: An Experimental Analogue Study
Authors: Jardin Bianca , Wulfert Edelgard
Published: April 2009

This study examined the effects of messages on altering risky gambling behavior in college students. While playing a chance‐based computerized game with play money, three groups of participants either viewed occasional accurate messages that correctly described the contingencies of the game, neutral messages unrelated to the contingencies, or no messages. Participants in the accurate message condition spent overall less money gambling, played fewer trials in the final phase of the game when all trials resulted in losses, and were more likely to quit the game while they still had money remaining in the bank. The findings suggest that “reminders” about the random nature of games and the overall negative rate of return might lead to more responsible gaming.
Maternal effects mechanism of population cycling: a formidable competitor to the traditional predator–prey view
Authors: Inchausti Pablo , Ginzburg Lev R
Published: April 2009

In the language of mathematics, one needs minimally two interacting variables (two dimensions) to describe repeatable periodic behaviour, and in the language of density dependence, one needs delayed, not immediate, density dependence to produce cyclicity. Neither language specifies the causal mechanism. There are two major potential mechanisms: exogenous mechanisms involving species interactions as in predator–prey or host–parasite, and endogenous mechanisms such as maternal effects where population growth results from the cross-generational transmission of individual quality. The species interactions view stemming from a major observation of Elton and a simultaneous independent theory by Lotka and Volterra is currently dominant. Most ecologists, when faced with cyclic phenomena, automatically look for an interacting species one step below or above in a food chain in order to find an explanation. Maternal effects hypothesis, verbally suggested in the 1950s, had only found its theoretical implementation in the 1990s. In a relatively short time, the degree of acceptance of this view grew to the level of a ‘minority opinion’ as evidenced by the widely used textbook of Begonet al. This short review attempts to describe the arguments for and against this internal two-dimensional approach.
The Snail Ilyanassa: A Reemerging Model for Studies in Development: Figure 1.
Authors: Gharbiah Maey , Cooley James , Leise Esther M. , Nakamoto Ayaki , Rabinowitz Jeremy S. , Lambert J. David , Nagy Lisa M.
Published: April 2009

INTRODUCTION

Ilyanassa obsoleta is a marine gastropod that is a long-standing and very useful model for studies of embryonic development. It is especially important as a model for the spiralian development program, a distinctive mode of early development shared by a large group of animal phyla, but poorly understood. Ilyanassa adults are readily obtainable and easy to keep in the laboratory, and they produce large numbers of embryos throughout most of the year. The embryos are amenable to classic embryological manipulation techniques as well as a growing number of molecular approaches. In this article, we present an overview of aspects of its biology and use as a model organism.
Dye Loading with Patch Pipettes: Figure 1
Authors: Eilers Jens , Konnerth Arthur
Published: April 2009

INTRODUCTION

This protocol describes the loading of individual cells with fluorescent probes via patch pipettes. The patch-clamp methodology has been successfully used for single-cell dye labeling in cultured neurons, brain slices, and in vivo preparations. A broad range of dyes can be used with this loading technique. Markers for morphological reconstruction (e.g., Lucifer yellow); ion-sensitive indicator dyes for monitoring second-messenger cascades (e.g., fura-2); and dye-labeled proteins for fluorescence resonance energy transfer (FRET), fluorescence correlation spectroscopy (FCS), and fluorescence recovery after photobleaching (FRAP) studies are all suitable for patch-clamp loading. The most widespread application of this technique has been for Ca2+ imaging. Whole-cell patch-clamp recordings represent a versatile loading technique that allows combined electrophysiological and optical measurements at a quantitative level.
Differences in virulence and immune response induced in a murine model by isolates ofMycobacterium ulceransfrom different geographic areas
Authors: Hurtado Ortiz R , Aguilar Leon D , Orozco Estevez H , Martin A , Luna Herrera J , Flores Romo L , Portaels F , Hernandez Pando R
Published: April 2009

Buruli ulcer (BU) is the third most common mycobacterial disease in immunocompetent hosts. BU is caused by Mycobacterium ulcerans, which produces skin ulcers and necrosis at the site of infection. The principal virulence factor of M. ulcerans is a polyketide-derived macrolide named mycolactone, which has cytotoxic and immunosuppresive activities. We determined the severity of inflammation, histopathology and bacillary loads in the subcutaneous footpad tissue of BALB/c mice infected with 11 different M. ulcerans isolates from diverse geographical areas. Strains from Africa (Benin, Ghana, Ivory Coast) induced the highest inflammation, necrosis and bacillary loads, whereas the strains collected from Australia, Asia (Japan, Malaysia, New Guinea), Europe (France) and America (Mexico) induced mild inflammation. Subsequently, animals were infected with the strain that exhibited the highest (Benin) or lowest (Mexico) level of virulence in order to analyse the local immune response generated. The Mexican strain, which does not produce mycolactone, induced a predominantly T helper type 1 (Th1) cytokine profile with constant high expression of the anti-microbial peptides beta defensins 3 and 4, in co-existence with low expression of the anti-inflammatory cytokines interleukin (IL)-10, IL-4 and transforming growth factor (TGF)-β. The highly virulent strain from Benin which produces mycolactone A/B induced the opposite pattern. Thus, different local immune responses were found depending on the infecting M. ulcerans strain.