bluuebunny/crossref_metadata_2025 huggingface dataset:
Doublecortin (DCX) and doublecortin‐like (DCL) are differentially expressed in the early but not late stages of murine neocortical development
Authors: Boekhoorn Karin , Sarabdjitsingh Angela , Kommerie Hendrik , de Punder Karin , Schouten Theo , Lucassen Paul J. , Vreugdenhil Erno
Published: January 2008

During corticogenesis, radial glia‐derived neural progenitors divide and migrate along radial fibers to their designated positions within the cortical plate. The microtubule‐associated proteins doublecortin (DCX) and doublecortin‐like (DCL) are critically involved in neuronal migration and division, and may function in a partially redundant pathway. Since little is known about the important early stages of corticogenesis, when neurogenesis is extensive, we addressed a possible differential role by examining spatiotemporal expression patterns of DCX, DCL, and the radial glia marker vimentin during murine development. We found expression patterns of DCL and DCX to differ remarkably prior to embryonic day (E)13. DCL was already expressed at E9 and largely overlapped with vimentin, whereas DCX expression started modestly from E10/E11 onward. DCL was mainly found in the ventricular zone, often in mitotic cells and in pial‐oriented radial fibers. In contrast, DCX was expressed in tangential fibers in the outer cortical regions. After E13, DCX and DCL expression largely overlapped but DCL expression had disappeared from the ventricular zone. Also, DCL levels were attenuated, whereas DCX remained high beyond E17. In conclusion, DCX and DCL are differentially expressed, particularly during early corticogenesis, consistent with their different functional roles. Given its involvement in mitosis, DCL appears to have a unique role in the early neuroepithelium that is different from later developmental stages when DCX is coexpressed. J. Comp. Neurol. 507:1639–1652, 2008. © 2008 Wiley‐Liss, Inc.
Ab Initio Study of the Magneto‐Optical Rotation of Diastereoisomers
Authors: Kula Mathias , Cappelli Chiara , Coriani Sonia , Rizzo Antonio
Published: January 2008

Experimental studies on the natural optical activity and Faraday rotation of the three different stereoisomers of tartaric acid were reported recently by Ruchon et al. [Chem. Phys. Lett. 2005, 412, 411]. The authors noted that the Faraday rotation of the meso (R,S) system differed from those of the (S,S) and (R,R) enantiomers, and derived a simple dipole–dipole interaction model to describe what they claim to be a “new property”. We present the results of both density functional theory (DFT) and coupled cluster calculations for a structurally elementary model system composed of two chiral carbon atoms presenting three diastereoisomers (C2H2Cl2F2), as well as a detailed DFT study of the natural and magnetic‐field‐induced optical rotation of tartaric acid. The effects of electron correlation, basis set, and conformational flexibility are analyzed. It is found that the specific Faraday rotations of the chiral (R,R) and meso forms of tartaric acid (for λ=632.8 nm) differ by about 3 %, a value which is quite close in magnitude—but of opposite sign—to that obtained with the simplified model proposed by Ruchon and co‐workers.
Papillary carcinoma with nodular fasciitis‐like stroma—A case report in pregnancy
Authors: Leal Isabel Irene Rama , Carneiro Fabiana Pirani , Basílio‐de‐Oliveira Carlos Alberto , Magalhães Albino Verçosa , Barbosa Tânia Wanderley Paes , da Silva Francileide Paes , de Castro Montenegro Frederico Sérgio Luis
Published: January 2008

We report a case of Papillary carcinoma with nodular fasciitis‐like stroma that is a rare variant of Papillary carcinoma characterized by a prominent stromal cell proliferation that causes difficulties in cytologic and histologic diagnosis. The patient was a 34‐year‐old woman, pregnant, presented with a 1‐year history of a growing mass in neck, dysphagia, and hoarseness. Physical examination revealed a firm nodular mass in thyroid gland. The fine needle aspiration biopsy specimen contained, besides diagnostic epithelial features of Papillary thyroid carcinoma, discohesive arrangement of bland spindle cells. Macroscopically, the specimen consisted of nodular tumor measuring 10 × 6 × 6 cm. Histologically the tumor was composed of small foci of neoplastic epithelial component distributed in abundant stroma. In immunohistochemistry, spindle cells in the stroma were positive for α‐smooth muscle actin and the neoplastic cells showed positive staining for TTF‐1 and progesterone receptor. Diagn. Cytopathol. 2008;36:139–141. © 2008 Wiley‐Liss, Inc.
The clinical and diagnostic impact of using standard criteria of adequacy assessment and diagnostic terminology on thyroid nodule fine needle aspiration
Authors: Jing Xin , Michael Claire W. , Pu Robert T.
Published: January 2008

The study was aimed to investigate the impact of using standard criteria for assessing specimen adequacy and diagnostic terminology (CAST) on fine‐needle aspiration (FNA) diagnosis and clinical management of thyroid nodules. The study included similar numbers of FNAs performed in 2 year before (group A) and 1.5 year after (group B) implementing the standard CAST. In comparison to group A, group B showed a significantly lower rate of nondiagnostic specimens (RND) (16.1% vs. 21.6%, P ≤ 0.01) and rate of descriptive diagnoses (RDD) (3.8% vs. 14.5%, P ≤ 0.001) and greater non‐neoplastic (70.0% vs. 64.1%, P < 0.05) and follicular cell lesions (7.4% vs. 4.3%, P < 0.05) but a similar percentage of neoplastic diagnoses. The rate of surgical follow‐up (RSF) was significantly higher in group B than in group A, overall (21.6% vs. 17.0%, P < 0.05), or in subgroups of non‐neoplastic (12.6% vs. 5.4%, P < 0.01) and neoplastic categories (81.0% vs. 61.0%, P < 0.05). The rate of cytohistologic concordance was higher in group B although the difference was not statistically significant. We concluded that use of the standard CAST on FNA diagnosis of thyroid nodules significantly reduced RND and RDD, providing more consistent diagnoses among the pathologists as well as better and more uniform communication between the pathologists and the clinicians. Furthermore, the cytohistological concordance was slightly better after CAST implementation, indicating that the improvement of diagnostic consistency among pathologists did not sacrifice the diagnostic accuracy. Diagn. Cytopathol. 2008;36:161–166. © 2008 Wiley‐Liss, Inc.
Comparison of p16INK4A and Hybrid Capture® 2 human papillomavirus testing as adjunctive tests in liquid‐based gynecologic SurePath™ preparations
Authors: Nassar Aziza , O'Reilly Katie , Cohen Cynthia , Siddiqui Momin T.
Published: January 2008

p16INK4a, cyclin‐dependent kinase inhibitor, is functionally inactivated in many tumors, including cervical cancer. We compared p16INK4A immunocytochemical staining and Hybrid Capture® 2 (HCII) on SurePath™ specimens using tissue biopsies (as the gold standard). Their utility in a spectrum of atypical and preneoplastic lesions, and their ability to accurately identify underlying lesions of CIN II or greater was assessed using biopsy follow‐up data. One‐hundred and seventeen residual SurePath™ samples were collected: 43 atypical squamous cells of undetermined significance (ASCUS), 47 low‐grade (LGSIL), and 27 high‐grade (HGSIL) squamous intraepithelial lesions. Two slides were prepared from each sample; one stained with the SurePath™ autocyte stain and one immunostained using the CINtec™ p16INK4a Cytology Kit (Dakocytomation). High‐risk HPV testing was performed using the HCII DNA test (Digene, Gaithersburg, MD). Available tissue biopsy follow‐up data was retrieved. p16INK4a was positive in 32.6% (14/43) ASCUS, 46.8% (22/47) LGSIL, and 48.1% (13/27) HGSIL specimens. HCII DNA test was positive in 41.9% (18/43) ASCUS, 78.7% (37/47) LGSIL, and 96.3% (26/27) HGSIL samples. The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values of p16INK4a and HCII were: 58.7% and 89.8%, 58.6% and 34.6%, 69.2% and 72.1%, 47.2% and 64.3%, respectively. In patients with cervical biopsies, the PPV of HCII (92.3%) results for a biopsy with CINII/III was significantly higher than the PPV of p16INK4a (52%) (P = 0.001). Using liquid‐based cytology specimens, HCII is a more sensitive test than p16INK4a for detection of abnormal cytology. HCII has a higher PPV than p16INK4a for identifying CIN II/III. Diagn. Cytopathol. 2008;36:142–148. © 2008 Wiley‐Liss, Inc.
Factors Influencing Anion Binding Stoichiometry: The Subtle Influence of Electronic Effects
Authors: Lowe Adam J. , Dyson Gail A. , Pfeffer Frederick M.
Published: January 2008

Six new, charge‐neutral norbornene‐based receptors 1a,1b–3a,3b were prepared, and their ability to interact with simple anions in DMSO was investigated using 1H NMR and UV/Vis spectroscopy. Binding of dihydrogenphosphate by the six receptors appeared to be based solely on steric constraints. In contrast, the binding stoichiometry of 3a and 3b to acetate was controlled by subtle electronic factors.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Palladium‐Catalyzed Silylation of Electron‐Deficient Aryl Iodides Using Triorganosilane in the Presence of Pyridine and LiCl
Authors: Iizuka Muneaki , Kondo Yoshinori
Published: January 2008

Palladium‐catalysed silylation of aryl iodides with electron‐withdrawing groups was efficiently achieved using pyridine and lithium chloride as additives and conducting the reaction at room temperature. Functionalized aryl[2‐(hydroxymethyl)phenyl]dimethylsilanes were also prepared by palladium‐catalysed reaction using THP‐protected [2‐(hydroxymethyl)phenyl]dimethylsilane as a silylating agent followed by deprotection. Rhodium‐catalysed 1,4‐addition of the arylsilane was carried out using cyclohexenone as an enone in excellent yield. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Strength vs. Accessibility: Unraveling the Patterns of Self‐Recognition in a Conformationally Locked Amino Alcohol (Eur. J. Org. Chem. 5/2008)
Authors: Mehta Goverdhan , Sen Saikat , Guru Row Tayur N. , Chopra Deepak , Chattopadhyay Sayani
Published: January 2008

The cover picture shows the iso‐surface of a novel amino alcohol molecule. The packing in the crystalline phase is determined principally by O?H···N hydrogen bonds and rarely encountered weak π‐π stacking interactions between the isolated double bonds. The acidic, but less accessible hydrogen atoms of the tertiary NH2 group in the amino alcohol remain as mere spectators in the supramolecular assembly, which therefore breaks a well‐known crystallographic lore. Details are discussed in the article by G. Mehta et al. on p. 805 ff.
Extracting stoichiometry, thermodynamics, and kinetics for the interaction of DNA with cadmium ion by capillary electrophoresis on‐line coupled with electrothermal atomic absorption spectrometry
Authors: Li Yan , Xia Yun‐Long , Jiang Yan , Yan Xiu‐Ping
Published: January 2008

Understanding the binding of cadmium with DNA is of great importance for elucidating the mechanism of cadmium genotoxicity and carcinogenicity. In the present work, CE on‐line coupled with electrothermal atomic absorption spectrometry was employed to study the binding electrophoretic behaviors, stoichiometry, thermodynamics, and kinetics for the interaction of cadmium cation (Cd(II)) with DNA. The stoichiometry (Cd(II) to DNA (as the concentration of base pairs)) for the interaction was determined to be 1:5. Two types of binding sites on DNA were observed with the binding constants of 106 and 105 L/mol, respectively, showing strong affinity of Cd(II) to DNA. The interaction of Cd(II) with both types of binding sites on DNA were driven by negative enthalpy change with a large positive entropy change. The binding of Cd(II) to DNA followed a first‐order kinetics for Cd(II) with the apparent activation energy of 45.7 ± 1.9 kJ/mol. The results obtained in present investigation would be helpful to understanding the genotoxicity and carcinogenicity of cadmium.
Heparin inhibits osteoclastic differentiation and function
Authors: Ariyoshi Wataru , Takahashi Tetsu , Kanno Takahiro , Ichimiya Hisashi , Shinmyouzu Kouhei , Takano Hiroshi , Koseki Takeyoshi , Nishihara Tatsuji
Published: January 2008

We investigated the effects of Glycosaminoglycans (GAGs) on mouse monocytic cell line in regard to their differentiation, proliferation, and function in vitro. RAW 264.7 cells were cultured with receptor activator of NF‐κB ligand (RANKL) and various GAGs. Osteoclastic cells were visualized by staining for tartrate‐resistant acid phosphatase (TRAP) and detected using a phenyl‐phosphate substrate method. RAW 264.7 cells were also cultured with stimulants contained in BD BioCoat OSTEOLOGICTM kit, and bone resorption activity was assessed by counting the numbers of resorption pits. We also examined the effect of heparin on cell growth using MTT assay, while the expression level of c‐Src protein was determined by immunoblot analysis. Heparin suppressed TRAP‐positive multinucleated cell formation and TRAP activity induced by RANKL, whereas the other GAGs showed no effects on osteoclast differentiation. Heparin also inhibited the formation of resorption pits, while the others did not. In the MTT assay, none of the tested GAGs had an influence on RAW 264.7 cell proliferation. However, heparin reduced the level of c‐Src protein in RAW 264.7 cells stimulated with RANKL. To determine the affinity of heparin and RANKL, they were subjected by HiTrap heparin column chromatography and each fraction was collected. Western blotting analysis revealed the expression of RANKL in the fraction bound to heparin. The binding of RANKL and heparin was confirmed by quartz‐crystal microbalance. These results indicate that the inhibitory effect of heparin toward osteoclastogenesis induced by RANKL is due to the binding of heparin to RANKL. J. Cell. Biochem. 103: 1707–1717, 2008. © 2008 Wiley‐Liss, Inc.
Phosphate and amide III mapping in sialoliths with Raman microspectroscopy
Authors: Kinoshita H. , Miyoshi N. , Miyoshi K. , Ogawa T. , Ogasawara T. , Kitagawa Y. , Itoh H. , Sano K.
Published: January 2008

Sialoliths, a cause of the salivary gland infection, are reported to be composed of inorganic and organic substances. However, the precise mechanism of sialolith formation remains unclear. The purpose of this report is to elucidate this mechanism by analyzing the precise distribution of phosphate (an inorganic substance) and amide III (an organic substance) in sialoliths by using Raman microspectroscopy. Sialoliths from the submandibular gland duct were analyzed by this form of observation and by a scanning electron microscope (SEM) equipped with an energy‐dispersive X‐ray spectroscope (EDX). In Raman microspectroscopy we analyzed the spectral peak of the phosphate (PO43−) symmetric stretching vibrational mode (υ1) at 960 cm−1 and that of amide III at 1265 cm−1 to demonstrate the mapping of an image of these elements showing a semiquantitative distribution of phosphate and amide III in the sialoliths. It was found that phosphate and amide III were concentrated at the center of the sialoliths, and the phosphate distribution in the sialoliths showed concentric laminations. These results indicated the possibility that the sialoliths originated from a nidus of organic materials and progressively grew by the deposition of layers of organic and inorganic materials. Copyright © 2008 John Wiley & Sons, Ltd.
Raman spectroscopy study of the Fermi resonance between a local vibration and the two‐phonon spectrum in PbI2 crystal
Authors: Yaremko A. , Dorogan V. , Motsnyi F.
Published: January 2008

The problem of complex Fermi resonance (FR) involving a local vibration is considered. It is shown for the first time that in the PbI2 crystal, owing to the features of phonon bands, the following two effects superpose on each other: (1) the traditional FR between the fundamental Ω(A1g) vibration and the two‐phonon states (TPS) arising from the 2Ω(Eu) vibrations, and (2) the FR between the impurity vibration and the same TPS band. It is shown theoretically that in the case of such complex FR the shape of the spectrum strongly depends on the impurity concentration, anharmonic constants and the phonon band structure. An analysis of experimental data and comparison with theory is made. Copyright © 2008 John Wiley & Sons, Ltd.
Experimental and statistical analysis methods for peptide detection using surface‐enhanced Raman spectroscopy
Authors: Mitchell Breeana L. , Patwardhan Anil J. , Ngola Sarah M. , Chan Selena , Sundararajan Narayan
Published: January 2008

Surface‐enhanced Raman spectroscopy (SERS) has the potential to make a significant impact in biology research due to its ability to provide information orthogonal to that obtained by traditional techniques such as mass spectrometry (MS). While SERS has been well studied for its use in chemical applications, detailed investigations with biological molecules are less common. In addition, a clear understanding of how methodology and molecular characteristics impact the intensity, the number of peaks, and the signal‐to‐noise of SERS spectra is largely missing. By varying the concentration and order of addition of the SERS‐enhancer salt (LiCl) with colloidal silver, we were able to evaluate the impact of these variables on peptide spectra using a quantitative measure of spectra quality based on the number of peaks and peak intensity. The LiCl concentration and order of addition that produced the best SERS spectra were applied to a panel of synthetic peptides with a range of charges and isoelectric points (pIs) where the pI was directly correlated with higher spectral quality. Those peptides with moderate to high pIs and spectra quality scores were differentiated from each other using the improved method and a hierarchical clustering algorithm. In addition, the same method and algorithm was applied to a set of highly similar phosphorylated peptides, and it was possible to successfully classify the majority of peptides on the basis of species‐specific peak differences. Copyright © 2008 John Wiley & Sons, Ltd.
Micro‐Raman spectroscopy of pigments contained in different calcium carbonate polymorphs from freshwater cultured pearls
Authors: Soldati A. L. , Jacob D. E. , Wehrmeister U. , Häger T. , Hofmeister W.
Published: January 2008

The metastable calcium carbonate polymorph vaterite has recently been found to occur commonly in freshwater cultured pearls from Japan and China. Organic pigment molecules in these vaterite regions of freshwater cultured pearls were analysed by resonance and near‐resonance micro‐Raman spectroscopy, in single spectra and in mapping modes and are compared with their aragonitic counterparts. Four different excitation wavelengths (487.9, 514.5, 532.2 and 632.8 nm) were used, resulting in differential increase of resolution for the pigments. Although vaterite areas were always lightly coloured (light yellow, light brown or white), ten different pigments were identified and a single colour is formed by a combination of three and up to nine polyenes of different lengths. The molecules were identified as unmethylated polyenes with effective chain lengths between 8 and 12 conjugated double bonds and FWHMs of 10 ± 2 cm−1. Additionally, and for the first time in pearls, methylated polyenes were detected together with unmethylated pigments in aragonite. Polyenes with chain lengths shorter than 8 or longer than 12 were not found in vaterite, whereas both shorter and longer pigment chains were observed in aragonite from the same pearls. Pigments have lower concentrations in vaterite and are distributed more homogeneously, while they have higher concentrations in aragonite and are arranged along the annual growth lines of the pearls. Copyright © 2008 John Wiley & Sons, Ltd.
Raman spectroscopic study of the uranyl carbonate mineral zellerite
Authors: Frost Ray L. , Dickfos Marilla J. , Čejka Jiří
Published: January 2008

Raman and infrared spectra of the uranyl mineral zellerite, Ca[(UO2)(CO3)2(H2O)2]·3H2O, were measured and tentatively interpreted. UO bond in uranyl and OH···O hydrogen bonds were calculated from the vibrational spectra. The presence of structurally nonequivalent water molecules in the crystal structure of zellerite was inferred. A proposed chemical formula of zellerite is supported. Raman bands at 3514, 3375 and 2945 cm−1and broad infrared bands at 3513, 3396 and 3326 cm−1 are related to the ν OH stretching vibrations of hydrogen‐bonded water molecules. Observed wavenumbers of these vibrations prove that in fact hydrogen bonds participate in the crystal structure of zellerite. The presence of two bands at 1618 and 1681 cm−1 proves structurally distinct and nonequivalent water molecules in the crystal structure of zellerite. Copyright © 2008 John Wiley & Sons, Ltd.
Bichromophoric behavior of nitrophenyl‐triazene anions: a resonance Raman spectroscopy investigation
Authors: Ando Rômulo A. , dos Santos Ana P. V. , Hörner Manfredo , Santos Paulo S.
Published: January 2008

Highly delocalized molecular frameworks with intense charge transfer transitions, known as push‐pull systems, are of central interest in many areas of chemistry, as is the case of nitrophenyl‐triazene derivatives. The 1,3‐bis(2‐nitrophenyl)triazene and 1,3‐bis(4‐nitrophenyl)triazene were investigated by electronic (UV‐Vis) and resonance Raman (RR) spectroscopies. The bichromophoric behavior of 1,3‐bis(4‐nitrophenyl)triazene anion opens the possibility of tuning with visible radiation, two distinct electronic states. The RR profiles of nitrophenyl‐triazene derivatives clearly show that the first allowed electronic state can be assigned to a charge transfer from the ring π system to the NO2moiety (ca520 nm), while the second, as a charge transfer from N3−to the aromatic ring (ca390 nm). In thepara‐substituted derivative, a more efficient electron transfer and a greater energy separation between the two excited states are observed. Copyright © 2008 John Wiley & Sons, Ltd.
Characterisation and functional properties of proteins of some Indian chickpea (Cicer arietinum) cultivars
Authors: Deep Singh Gagan , Wani Ali Abas , Kaur Devinder , Sogi Dalbir Singh
Published: January 2008

BACKGROUND: Chickpea (Cicer arietinum L.) proteins have received attention during recent years owing to their higher biological values and better functional ingredients than oilseed proteins. In this study the composition, fractionation, electrophoretic behaviour and functional properties of five chickpea protein concentrates were determined.

RESULTS: The chickpea proteins contained 15.9–54.8 g kg−1 albumin, 48.9–154.1 g kg−1 globulin, 39.2–76.5 g kg−1 glutelin and traces of prolamin. Electrophoresis of the various fractions revealed that albumin and globulin were made up of sub‐units of different molecular weights ranging from 7 to 96 kDa. Water and oil absorption of the protein concentrates varied from 1.15 to 2.75 g g−1 and from 2.60 to 5.65 g g−1 respectively. Foaming capacity and foam stability of the protein concentrates were good and improved with the addition of salt (10 g L−1 NaCl) or sugar (100 g L−1 sucrose) at both isoelectric and neutral pH. Emulsifying capacity and emulsion stability of the protein concentrates were good and excellent respectively.

CONCLUSION: Protein concentrates prepared from chickpeas have potential use in food formulations owing to their good emulsifying/foaming and water/oil‐binding capacities. Copyright © 2008 Society of Chemical Industry
Nurse dose: What's in a concept?
Authors: Manojlovich Milisa , Sidani Souraya
Published: January 2008

Many researchers have sought to address the relationship between nursing care and patient outcomes, with inconsistent and contradictory findings. We conducted a concept analysis and concept derivation, basing our work on theoretical and empirical literature, to derive nurse dose as a concept that pulls into a coherent whole disparate variables used in staffing studies. We defined nurse dose as the level of nursing reflected in the purity, amount, frequency, and duration of nursing care needed to produce favorable outcomes. All four parameters of nurse dose used together can facilitate our understanding of how nursing contributes to patient outcomes. Ongoing investigation will help to identify the parameters of nurse dose that have the greatest effect on outcomes. © 2008 Wiley Periodicals, Inc. Res Nurs Health 31:310–319, 2008
Translational research: Essential contributions from interpretive nursing science
Authors: Chesla Catherine A.
Published: January 2008

Translating research into practice is a central priority in the National Institutes of Health Roadmap. Nurse scientists must reevaluate how proposed research fits within and contributes not only to the development of new knowledge, but to the translation of that knowledge to the care of diverse communities and populations. Key barriers to the translation of evidence based practices in health programs and initiatives have been identified in the health services and nursing literature. Contributions that interpretive research approaches enable in addressing those barriers are articulated. © 2008 Wiley Periodicals, Inc. Res Nurs Health 31:381–390, 2008
Dynamics of NGO legitimacy: how organising betrays core missions of INGOs
Authors: Ossewaarde Ringo , Nijhof André , Heyse Liesbet
Published: January 2008

International non‐governmental organisations (INGOs) are prominent actors in the international arena, aiming to improve the life of disadvantaged people. However, INGOs often do not succeed in doing this. Consequently, INGO legitimacy is regularly questioned. Increased transparency and tightened accountability mechanisms are often‐mentioned solutions to this problem. Based on an analysis of four dimensions of INGO legitimacy—normative, regulatory, cognitive and output legitimacy—we argue that this is not necessarily adequate. We conclude that INGO mission statements create a normative source of legitimacy, but that this, in itself, is not enough to ground INGO legitimacy: it also needs to be institutionalised and organised. However, as a result of power relations and resulting pressures for accountability and transparency, as defined by their external stakeholders, INGOs experience a permanent struggle to reconcile their mission with the requirements for regulatory, cognitive and output legitimacy. The more these stakeholders press for increased organisation of INGO work, the more the pursuit of the core objectives of INGOs is obstructed. We illustrate this argument with the case of the post‐Tsunami humanitarian intervention (2004/2005). Copyright © 2008 John Wiley & Sons, Ltd.
Creating a statewide educational data system for accountability and improvement: A comprehensive information and assessment system for making evidence‐based change at school, district, and policy levels
Authors: Felner Robert D. , Bolton Natalie , Seitsinger Anne M. , Brand Stephen , Burns Amy
Published: January 2008

This article reports on one ongoing statewide effort to create a high‐quality data reporting and utilization system (i.e., High‐Performance Learning Community [HiPlaces] Assessment) to inform educational accountability and improvement efforts system. This effort has undergoing refinement for more than a decade. The article describes the features of this system, particularly how empirically based psychological theory and research informed both the development and the overall design of the assessment method. This system, unlike those used by other educational institutions, is unusual in that from the onset of the development and then the implementation, the assessment moved well beyond the simple assessment of the performance and achievement of students to include a comprehensive assessment of all aspects of the developmental, educational, fiscal, and policy conditions that comprise the ecology of the public education system, at all levels, as well as of the developmental and educational needs and attainment of students. The use of data was integral in guiding specific and ongoing, state‐, district‐, school‐, and classroom‐level improvement plans and efforts, including the development, monitoring, evaluation, and refinement of the program. The major goal that guided this system is, and always has been, the enhancement of schools and students' lives. © 2008 Wiley Periodicals, Inc.
Investigation of Tb‐related green emission in group‐III nitrides by time‐resolved photoluminescence measurement
Authors: Wakahara A. , Takemoto K. , Oikawa F. , Okada H. , Ohshima T. , Itoh H.
Published: January 2008

Luminescence properties of Tb impurity in AlGaN are investigated various Al composition using time‐resolved photoluminescence (TRPL). When the AlN molar fraction is increased, the luminescence intensity corresponding to inner‐shell transitions in Tb becomes strong. At low‐temperatures, 5D3–7FJ transitions are dominant in AlN‐rich samples, whereas 5D4–7FJ transitions are dominant at high‐temperature. Temperature dependence of the transient decay and the luminescence intensity suggest thermally activated energy‐transfer process and suppression of energy‐back‐transfer due to widening of the band‐gap. Therefore, the large improvement of PL capability in AlGaN may be due to increase of energy transfer efficiency and/or increase of active Tb impurity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of Yb impurity on Er‐related emission in Al0.70Ga0.30As:Er,Yb epitaxially grown on GaAs substrate
Authors: Arai Tomoyuki , Uekusa Shin‐ichiro
Published: January 2008

The effects of Yb impurity on the optical properties of an Er,Yb‐implanted Al0.70Ga0.30As epitaxial layer were studied. The defect characterizations were carried out for undoped Al0.70Ga0.30As and Al0.70Ga0.30As:Er,Yb samples annealed in the temperature range from 500 °C to 900 °C. From results of photoluminescence (PL), Raman spectroscopy and positron annihilation spectroscopy, it was found that the implantation damage in Al0.70Ga0.30As:Er,Yb samples are recovered by the thermal annealing at a temperature above 700 °C. Maximum PL intensity of Er‐related emission was observed from the Al0.70Ga0.30As:Er,Yb sample annealed at 800 °C. The energy transfere from Yb3+ to Er3+ was also investigated by selectively excited photoluminescence (PL) and PL excitation spectroscopy. It was also observed that the energy was transfered from Yb3+ to Er3+. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Site‐specific excitation of Eu ions in GaN
Authors: Tafon Penn S. , Fleischman Z. , Dierolf V.
Published: January 2008

We performed cathodoluminescence (CL) studies on Eu‐doped GaN layers that were grown using the Interrupted Growth Epitaxy (IGE) method. We compare these results with our site‐selective combined excitation‐emission spectroscopy (CEES) studies in which numerous Eu3+ incorporation sites can be identified unambiguously. We find that for high beam currents the emission intensity saturates in a way that can only be accounted for by a coexistence of at least two different excitation processes. The ratio in excitation efficiency between these two processes is about 5. This conclusion is supported by the CL spectra which show less pronounced saturation for the majority substitutional incorporation site compared to the defect trap‐related (most likely interstitial) site. We further find that only a small fixed portion of the majority site can be excited through electron bombardment. We explain this behavior with a model for the excitation process in which defects are involved as an intermediate trap of excitation. Energy transfer can occur only to those substitutional Eu ions that are in close proximity to the trap. In the case that the Eu ion defect constitutes the trap itself, the spectra are clearly distinguishable and the transfer rates are highest. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation and photoluminescence of Eu‐doped GaN films by radio frequency magnetron sputtering method
Authors: Shirakata Sho , Yudate Shinji
Published: January 2008

The red‐luminescent Eu‐doped GaN film has been prepared on both sapphire and GaN/sapphire substrates by the conventional RF magnetron sputtering method using a compound powder target (GaN + EuN), N2 sputtering gas and subsequent annealing in NH3. The GaN:Eu layers exhibited a red sharp photoluminescence (PL) line at 622 nm due to 5D0–7F2 transition of Eu3+ ions together with series of narrow PL lines: 5D1–7F1 (540 nm), 5D0–7F1 (580–600 nm), and 5D0–7F3 (665 nm). Dependence of Eu‐related PL on the growth condition is described: Eu‐doping level (EuN in target), substrate temperature (Ts), growth time, and annealing temperature (Ta). The optimum conditions for luminescent GaN:Eu are: (i) the Eu of 2 mol% in target, (ii) Ts at 400–450 °C, and (iii) Ta at 1000 °C for 2 hours. Improvements in intensity and reproducibility of Eu‐related PL have been attained by: (i) the increase of growth time, (ii) the use of undoped GaN buffer layer, (iii) the improvement of the target quality, and (iv) the use of the MOVPE grown GaN/Al2O3 template. Preliminary studies of various PL properties are described: the fine structure in PL spectra, PL decay characteristics, temperature dependence and photoluminescence excitation spectrum (PLE). The PL results are discussed in comparison with those in the GaN:Eu grown by other methods in literature. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Defects in organic electronic devices
Authors: Nguyen T. P.
Published: January 2008

The performance of organic electronic devices depends strongly on the quality of the semiconductor used, and the transport process, in particular is greatly affected by the defect states of the material. Knowledge of trapping parameters is therefore of prime importance for studying organic devices. While defects in conventional semiconductors are well known and can be more or less controlled during processing, the formation of defects in organic materials is still not well understood, and consequently, it is difficult to control the defect states in organic devices. For defects that are electrically active or traps, techniques such as thermally stimulated currents, impedance spectroscopy, or deep level transient spectroscopy have been successfully used for determining the corresponding parameters (density, energy level, capture cross section). In this work, we review some fundamental aspects of trap analysis in organic devices by highlighting their role in the charge transport process in these materials. We present updated data from trap studies in polyfluorene derivative based diodes and we address specific problems in analyzing traps in polymers and organic semiconductors. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electrical characterization of defects introduced in Ge during electron beam deposition of different metals
Authors: Auret F. D. , Coelho S. M. M. , Hayes M. , Meyer W. E. , Nel J. M.
Published: January 2008

We have used deep level transient spectroscopy to characterize the defects introduced in n‐type, Sb‐doped, Ge during electron beam deposition of different metals for Schottky contact formation. We have found that the relative concentration of the electron beam induced defects depended on the metal used: metals that required a higher beam intensity to evaporate, e.g. Ru, resulted in larger defect concentrations than metals that required a lower beam intensity, e.g. Pd. The nature of some of these defects could be established by comparing their properties to those of well‐known defects introduced by electron irradiation of the same material. The most prominent defect thus identified was the E‐center, i.e. the Sb‐V center. This defect forms when vacancies, that are introduced during the interaction of energetic metal and other particles with the Ge surface, diffuse into the Ge where they bond to Sb dopant atoms. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman spectroscopy of WO3 nano‐wires and thermo‐chromism study of VO2 belts produced by ultrasonic spray and laser pyrolysis techniques
Authors: Mwakikunga B. W. , Sideras‐Haddad E. , Forbes A. , Arendse C.
Published: January 2008

Novel optical and electrical properties of newly synthesized nano‐wires of monoclinic WO3 and nano‐belts of rutile VO2 have been investigated by Raman spectroscopy and thermo‐chromism studies respectively. Phonon confinement is observed in the WO3 nano‐wires and the previously modified Richter equation is fitted to the experimental Raman spectroscopy data to obtain the optical phonon dispersion relations for the 713 cm–1 branch and the 808 cm–1 branch of WO3 phonon spectra for the first time. Electrical measurements on the VO2 nano‐belts at varying temperature reveal an enhanced hysteresis width of about 83 °C surpassing previously reported values on the thermo‐chromism studies on VO2. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical and electronic properties of GaInNP alloys – a new material system for lattice matching to GaAs
Authors: Buyanova I. A. , Chen W. M. , Tu C. W.
Published: January 2008

In this paper we will review our recent results from optical characterization studies of GaInNP. We will show that N incorporation in these alloys affects their structural and defect properties, as well as the electronic structure. The main structural changes include (i) increasing carrier localization due to strong compositional fluctuations, which is typical for all dilute nitrides, and (ii) N‐induced long range ordering effects, specific for GaInNP. The observed degradation of radiative efficiency of the alloys upon increasing N content is attributed to formation of several defects acting as centres of efficient non‐radiative recombination. One of the defects is identified as a complex involving a Ga interstitial atom. N incorporation is also found to change the band line up from the type I in the GaInP/GaAs structures to the type II in the GaInNP/GaAs heterojunctions with [N] > 0.5%. For the range of N compositions studied ([N] ≤ 2%), a conduction band offset at the GaInNP/GaAs interface is found to nearly linearly depend on [N] at –0.10 eV/%, whereas the valence band offset remains unaffected. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Photoluminescence under magnetic field and hydrostatic pressure for probing the electronic properties of GaAsN
Authors: Polimeni A. , Pettinari G. , Trotta R. , Masia F. , Felici M. , Capizzi M. , Lindsay A. , O'Reilly E. P. , Niebling T. , Stolz W. , Klar P. J. , Martelli F. , Rubini S.
Published: January 2008

The puzzling electronic properties of GaAsN have been investigated through the compositional dependence of two highly sensitive band structure parameters: the electron effective mass, me, and the electron gyromagnetic factor, ge. In the N concentration range from 0% to 0.7%, both me and ge show a highly nonlinear dependence on N composition that can be explained in terms of alternating on‐ and off‐resonance conditions between the red‐shifting conduction band edge and specific energy‐pinned N cluster states. Furthermore, the electronic properties of the material are studied under hydrostatic pressure, P. This allows tuning in a same sample the interaction between extended and localized states and disclosing a hierarchy between different nitrogen complexes as regards the extent of the perturbation these complexes exert on the electronic properties of the GaAs host crystal. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Nanostructure engineering of staggered InGaN quantum wells light emitting diodes emitting at 420–510 nm
Authors: Arif Ronald A. , Ee Yik‐Khoon , Tansu Nelson
Published: January 2008

We demonstrated staggered InGaN quantum wells (QW) grown by metalorganic chemical vapor deposition (MOCVD) as improved active region for visible light emitters. Theoretical studies indicate that staggered InGaN QW with step‐function like In‐content in the well offers significantly improved radiative recombination rate and optical gain, in comparison to the conventional InGaN QW. Experimental results of light emitting diode (LED) structure utilizing staggered InGaN QW show good agreement with theory. Staggered InGaN QW allows polarization engineering leading to improvement of photoluminescence intensity and LEDs output power as a result of enhanced radiative recombination rate. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Editorial: phys. stat. sol. (a) 205/1
Authors: Stutzmann Martin
Published: January 2008

How do you find the scientific information and the manuscript reference you need? The answer to this basic but very important question for every active scientist has changed significantly over the last 30 years. When I was a Ph.D. student or a young postdoc, I would venture regularly to a strange and quiet place called a “library”, where all important journals in my field could be easily identified already from the amount of the shelve space they filled. To find a specific reference and to preserve it for future use was limited by the physical exercise to carry a stack of heavy volumes to the copy machine and to press a “copy” button for each page I really wanted to keep. On the way, sometimes I actually found another interesting paper just by browsing through the latest issue of Journal X, and I copied this one, too. And in most cases, I even read what I copied.

Today, things are much better! All relevant information is available online in electronic form, so I do not have to leave my office anymore to find out what's new. The impact factors of journals and the h‐factors of authors help me to distinguish good from bad, or at least that is the hope. Whenever I search for a specific topic, anyhow I will get more hits than I can digest in a realistic time. Fortunately, printers by now are so fast and powerful that I can transfer the rest to a printout which I will, most likely, never use again in the foreseeable future.

But seriously, although the way to make use of and to deal with scientific information has changed drastically in the last couple of decades, the basic needs of active scientists for reliable, up‐to‐date, and easily accessible information exchange with their international colleagues worldwide has basically remained the same. We at physica status solidi, therefore, for more than 45 years have been and are dedicated to provide exactly that service to our authors and readers, whether they make use of the pss hardcopies in the library or whether they browse the online files of physica status solidi. Last year, more than 2500 articles have been published after strict peer review and careful editing, which makes physica status solidi (nomen est omen) the second largest journal series in solid state physics. The journal has more than doubled in volume since the year 2000, but the Impact Factor also has increased by a factor of two since 1995, showing that we did not trade in quantity for quality. And, last but not least, the visibility of the journal series as measured by the number of full text downloads has increased by a similar factor of two in the last 24 months alone.

In October 2007, more than 40000 full text downloads of physica status solidi articles have been registered by the Wiley Interscience data base. Unfortunately, we have no idea how many of these articles have actually been read …

In the name of the entire pss‐team, I thank all of you for your continued support of and interest in physica status solidi and wish you a successful year 2008!
Evidences of the virtual Anderson transition in a narrow impurity band of p‐GaAs/AlGaAs quantum wells: ε4 conductivity and electric breakdown at low temperatures
Authors: Agrinskaya N. V. , Kozub V. I. , Poloskin D. S. , Shamshur D. V. , Chernyaev A. V.
Published: January 2008

In highly doped uncompensated p‐type layers within the central part of GaAs/AlGaAs quantum wells at low temperatures we observed an activated behavior of the conductivity with low activation energies (1‐3) meV which cannot be ascribed to standard mechanisms. We attribute this behavior to the delocalization of hole states near the maximum of the narrow impurity band (characteristic for 2D) in the sense of the Anderson transition. Low temperature conduction ε4 is supported by an activation of minority carriers (resulting from a weak compensation by back‐ground defects) from the Fermi level to the band of delocalized states mentioned above. The corresponding behavior can be specified as virtual Anderson transition. Low temperature transport (<4 K) exhibits also strong nonlinearity of a breakdown type characterized in particular by S‐shaped I‐V curve. The nonlinearity is observed in unexpectedly low fields (<10 V/cm). Such a behavior can be explained by a simple model implying an impact ionization of the localized states of the minority carriers mentioned above to the band of Anderson‐delocalized states. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron‐electron relaxation in disordered interacting systems
Authors: Bozsoki Peter , Varga Imre , Schomerus Henning
Published: January 2008

We study the relaxation of a non‐equilibrium carrier distribution under the influence of the electron‐electron interaction in the presence of disorder. Based on the Anderson model, our Hamiltonian is composed from a single particle part including the disorder and a two‐particle part accounting for the Coulomb interaction. We apply the equation‐of‐motion approach for the density matrix, which provides a fully microscopic description of the relaxation. Our results show that the nonequilibrium distribution in this closed and internally interacting system relaxes exponentially fast during the initial dynamics. This fast relaxation can be described by a phenomenological damping rate. The total single particle energy decreases in the redistribution process, keeping the total energy of the system fixed. It turns out that the relaxation rate decreases with increasing disorder. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Many electron theory of 1/f ‐noise in hopping conductivity
Authors: Burin Alexander L. , Shklovskii Boris I. , Kozub Veniamin I. , Galperin Yuri M. , Vinokur Valerii
Published: January 2008

We show that 1=f ‐noise in the variable range hopping regime is related to transitions of many‐electrons clusters (fluctuators) between two almost degenerate states. Giant fluctuation times necessary for 1=f ‐noise are provided by slow rate of simultaneous tunneling of many localized electrons and by large activation barriers for their consecutive rearrangements. The Hooge constant steeply grows with decreasing temperature because it is easier to find a slow fluctuator at lower temperatures. Our conclusions qualitatively agree with the low temperature observations of 1=f ‐noise in p‐type silicon and GaAs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low‐temperature conductance mechanisms in p‐Si/SiGe heterostructures in high magnetic fields
Authors: Drichko I. L. , Dyakonov A. M. , Smirnov I. Yu. , Suslov A. V. , Galperin Y. M. , Vinokur V. , Myronov M. , Mironov O. A.
Published: January 2008

Low‐temperature conductance mechanism in low‐density Si/SiGe heterostructures in high magnetic fields (ultra‐quantum limit) is studied using AC and DC transport measurements. Evidence of the Wigner crystal in this regime is given. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tuning electron‐phonon and Coulomb interactions in organic field effect transistors
Authors: Fratini S. , Morpurgo A. F. , Ciuchi S.
Published: January 2008

Recent experiments have demonstrated that the performances of organic FETs strongly depend on the dielectric properties of the gate insulator. In particular, it has been shown that the temperature dependence of the mobility evolves from a metallic‐like to an insulating behavior upon increasing the dielectric constant of the gate material. This phenomenon can be explained in terms of the formation of small polarons, due to the polar interaction of the charge carriers with the phonons at the organic/dielectric interface. Building on this model, it is shown that the Coulomb repulsion between the carriers can lead to a further reduction of the electron mobility at high concentrations, as can be reached in devices with highly polarizable gate dielectrics. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)