bluuebunny/crossref_metadata_2025 huggingface dataset:
Mass spectrometric analysis of the S‐layer proteins from Clostridium difficile demonstrates the absence of glycosylation
Authors: Qazi Omar , Hitchen Paul , Tissot Bérangère , Panico Maria , Morris Howard R. , Dell Anne , Fairweather Neil
Published: October 2008

Like many other bacterial cell surfaces, the cell wall of Clostridium difficile is also encapsulated by a proteinaceous paracrystalline layer, the surface (S)‐layer. In many bacterial species, the S‐layer proteins (SLPs) have been shown to be glycosylated, whereas in other species glycosylation is absent. Unusually, the S‐layer of C. difficile is composed of two distinct proteins, the high‐molecular weight (HMW) and low‐molecular‐weight (LMW) SLPs. Previous investigations have reported that one or both of these SLPs are glycosylated, though no definitive study has been conducted. We have used a variety of mass spectrometric approaches to analyse SLPs from a number of strains of C. difficile for the presence of associated glycans. Analysis of intact SLPs by matrix assisted laser desorption/ionisation time of flight (MALDI‐ToF) mass spectrometry demonstrated that the observed molecular masses matched the predicted masses of the LMW and HMW SLPs. Furthermore, analysis of Cyanogen bromide (CNBr) and tryptic peptides displayed no evidence of post‐translational modification. In the first in‐depth study of its kind, we unequivocally demonstrate that the S‐layer proteins from the C. difficile strains investigated are not glycosylated. Copyright © 2008 John Wiley & Sons, Ltd.
Rotating three‐dimensional dynamic culture of adult human bone marrow‐derived cells for tissue engineering of hyaline cartilage
Authors: Sakai Shinsuke , Mishima Hajime , Ishii Tomoo , Akaogi Hiroshi , Yoshioka Tomokazu , Ohyabu Yoshimi , Chang Fei , Ochiai Naoyuki , Uemura Toshimasa
Published: October 2008

The method of constructing cartilage tissue from bone marrow‐derived cells in vitro is considered a valuable technique for hyaline cartilage regenerative medicine. Using a rotating wall vessel (RWV) bioreactor developed in a NASA space experiment, we attempted to efficiently construct hyaline cartilage tissue from human bone marrow‐derived cells without using a scaffold. Bone marrow aspirates were obtained from the iliac crest of nine patients during orthopedic operation. After their proliferation in monolayer culture, the adherent cells were cultured in the RWV bioreactor with chondrogenic medium for 2 weeks. Cells from the same source were cultured in pellet culture as controls. Histological and immunohistological evaluations (collagen type I and II) and quantification of glycosaminoglycan were performed on formed tissues and compared. The engineered constructs obtained using the RWV bioreactor showed strong features of hyaline cartilage in terms of their morphology as determined by histological and immunohistological evaluations. The glycosaminoglycan contents per µg DNA of the tissues were 10.01 ± 3.49 µg/µg DNA in the case of the RWV bioreactor and 6.27 ± 3.41 µg/µg DNA in the case of the pellet culture, and their difference was significant. The RWV bioreactor could provide an excellent environment for three‐dimensional cartilage tissue architecture that can promote the chondrogenic differentiation of adult human bone marrow‐derived cells. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 517–521, 2009
MRI‐based surgical simulation of transtrochanteric rotational osteotomy for femoral head osteonecrosis
Authors: Koyama Tsuyoshi , Sugano Nobuhiko , Nishii Takashi , Miki Hidenobu , Takao Masaki , Sato Yoshinobu , Yoshikawa Hideki , Tamura Shinichi
Published: October 2008

Transtrochanteric rotational osteotomy (TRO) is one of the joint‐preserving surgical treatments for osteonecrosis of the femoral head (ONFH). It can prevent collapse of the femoral head as necrotic lesions in the weight‐bearing portion can be moved sufficiently to a less weight‐bearing portion by anterior rotation, posterior rotation, or varus angulation. Patient selection and preoperative planning are important to determine indications for TRO. It has been reported that successful TRO requires at least 34% of the weight‐bearing area supported by the intact part of the femoral head. However, this ratio is difficult to preoperatively quantify according to the rotation angle using conventional two‐dimensional MR images or X‐rays. Therefore, we developed a method of simulating TRO using three‐dimensional (3D) models reconstructed from 3D MR images and applied it to serial patients with types C1 and C2 osteonecrosis at stage 1 or 2. The simulation visualized positional changes of the necrotic lesion in the weight‐bearing area and enabled quantitation of the postoperative intact ratio. Our surgical simulation is useful for evaluating the postoperative intact ratio and for determining indications for TRO as well as the optimal angle of femoral head rotation and varus angulation. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 447–451, 2009
Altered gene expression in early osteochondrosis lesions
Authors: Mirams Michiko , Tatarczuch Liliana , Ahmed Yasser A. , Pagel Charles N. , Jeffcott Leo B. , Davies Helen M.S. , Mackie Eleanor J.
Published: October 2008

Osteochondrosis is a condition involving defective endochondral ossification and retention of cartilage in subchondral bone. The pathophysiology of this condition is poorly characterized, but it has been proposed that the fundamental defect is failure of chondrocyte hypertrophy. The aim of the current study was to characterize phenotypic changes in chondrocytes associated with the initiation of osteochondrosis. Early lesions were induced in an equine model of osteochondrosis by feeding foals a high energy diet for 8 or 15 weeks. Lesions in articular‐epiphyseal growth cartilage were examined histologically and by quantitative PCR analysis of expression of a number of genes representative of pathways that regulate chondrocyte behavior during endochondral ossification. There were more cells present in clusters in the lesions compared to normal articular cartilage. Expression of matrix metalloproteinase‐13, type I collagen, type X collagen, and Runx2 mRNA was significantly greater in the lesions compared to normal cartilage from the same joint. Expression of vascular endothelial growth factor, type II collagen, connective tissue growth factor, aggrecan, Sox9, and fibroblast growth factor receptor 3 mRNA was not significantly different in lesions than in control cartilage. These observations suggest that osteochondrosis does not result from failure of chondrocytes to undergo hypertrophy. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27: 452–457, 2009
Optimization of SERS activities of gold nanoparticles and gold‐core–palladium‐shell nanoparticles by controlling size and shell thickness
Authors: Fang Ping‐Ping , Li Jian‐Feng , Yang Zhi‐Lin , Li Li‐Mei , Ren Bin , Tian Zhong‐Qun
Published: October 2008

The optimization of surface‐enhanced Raman scattering (SERS) activity of gold nanoparticles is essential for further enhancing SERS capability in terms of high sensitivity, stability and reproducibility. Recently, we utilized a simple seed‐mediated growth method to synthesize monodisperse Au nanoparticles with controllable size from about 16 to 160 nm, which were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV–vis spectroscopy. These nanoparticles can be easily formed as a uniform thin film on glass carbon or gold substrates with an area larger than 1 mm.2 The nanoparticle film with the size range of 120–135 nm showed the highest SERS activity with the excitation wavelength of 632.8 nm. Using pyridine as the probe molecule, the average enhancement factorcould reach up to 107. Finite difference time domain (FDTD) calculationwas employed to explain the size‐dependent SERS activity. The optimum‐sized Au nanoparticles were utilized to further prepare Au–Pd core–shell (Au@Pd)nanoparticles in order to greatly enhance the SERS activity of the Pd shell. The enhancement factor of the ultrathin Pd shell was found to be over 5 × 104. Thus the originally low enhancement factor of Pd could be improved substantially. Copyright © 2008 John Wiley & Sons, Ltd.
Laparoscopy‐assisted distal gastrectomy with D2 lymphadenectomy for T2b advanced gastric cancers: Three Years' experience
Authors: Hur Hoon , Jeon Hae Myung , Kim Wook
Published: October 2008

Background

The application of laparoscopy‐assisted distal gastrectomy (LADG) with advanced gastric cancer (AGC) is a controversial. The purpose of this study was to assess the possibility of using LADG application to AGC.

Methods

Of 160 patients who underwent LADG with D2 lymphadenectomy between April 2004 and March 2007, 26 patients with stage pT2b were selected and compared to 25 patients of the same stage who underwent open distal gastrectomy (ODG) within same period. The comparison was based on the clinicopathologic characteristics, surgical outcome, and follow‐up results.

Results

There was no significant difference between LADG and ODG groups in most operation results including complication rates (15.4% vs. 16.0%, P = 1.000) except for less average loss of blood (160.0 ml vs. 215.0 ml, P = 0.012) and longer average operating time (255.0 min vs. 190.0 min, P < 0.001) in LADG. Three‐year overall survival rates (88.2% vs. 77.2%; P = 0.246) and disease‐free survival rates (71.4% vs. 53.4%; P = 0.757) were not significantly different in LADG and ODG groups.

Conclusions

The early results of current study suggest that LADG for AGC is technically safe and oncologically feasible. Therefore, LADG should be considered as a curative treatment for AGC not exposed to serosa. J. Surg. Oncol. 2008;98:515–519. © 2008 Wiley‐Liss, Inc.
Morphology and Photophysical Properties of Electrospun Light‐Emitting Polystyrene/Poly(p‐phenylene ethynylene) Fibers
Authors: Changsarn Sutheerat , Mendez James D. , Weder Christoph , Supaphol Pitt
Published: October 2008

Ultra‐thin fibers, consisting of blends of a PPE derivative and polystyrene, with average diameters ranging from 430 to 1 200 nm, were produced by electrospinning. The electrospinnability was significantly improved by adding pyridinium formate to the spinning solution. FT‐IR spectroscopy was used to confirm the composition of the electrospun fibers and their morphology was probed by SEM. The optical properties of the as‐prepared solutions, pristine and annealed fibers, and corresponding spin‐coated and solution‐cast films were investigated by UV‐vis spectroscopy. A comparison of the PL emission spectra revealed aggregation of PPE molecules in the electrospun materials but the extent of aggregation can be reduced if the materials are annealed above the glass transition temperature.

magnified image
Female nudity in print advertising: An analysis of gender differences in arousal and Ad response
Authors: LaTour Michael S.
Published: October 2008

Previous research on the dimensionality of arousal indicates tension arousal is associated with negative feelings and energy arousal is associated with positive feelings. Women were found to generate more tension and negative feelings towards explicit female nudity in print ads than men. Men were more energized and positive in their feelings about such ads. The results have substantial strategic implications.
Transformed rat tracheal epithelial cells exhibit alterations in transforming growth factor‐β secretion and responsiveness
Authors: Steigerwalt Ronald W. , Rundhaug Joyce E. , Nettesheim Paul
Published: October 2008

The purpose of our studies was to define abnormalities in the transforming growth factor‐β (TGF‐β) system of transformed rat tracheal epithelial (RTE) cells that might cause their abnormal growth behavior. We found that many, but not all, of the transformed cell lines were hyporesponsive or unresponsive to the growth inhibitory effects of TGF‐β1. Scatchard and receptor cross‐linking analyses indicated that loss of TGF‐β1 responsiveness of transformed cells was probably not due to changes in receptor number or affinity, or to changes in expression of the three TGF‐β‐binding protein subtypes. Transformed cells were found to secrete far less TGF‐β‐like activity (<1/10) than primary cells. Cultured normal and transformed RTE cells expressed three TGF‐β1 transcripts of 2.5, 1.9, and 1.4 kb. In contrast, rat kidney tissue, a rat embryo fibroblast cell line, and a rat liver cell line expressed only the typical 2.5‐kb mRNA transcript commonly reported in the literature. In spite of the marked differences in TGF‐α secretion between normal and transformed cells, their levels of TGF‐β1 mRNA expression were similar. This suggests a change in the posttranscriptional regulation of TGF‐β1 expression. TGF‐β2 message was not detected in either normal or transformed RTE cells in culture. These findings are consistent with the hypothesis that the abnormal growth behavior of transformed RTE cells is at least in part due to disturbances of the TGF‐β system.
Rhabdomyosarcoma in infants under one year of age: Experience of the institut Gustave‐Roussy
Authors: Salloum Emile , Flamant Françoise , Rey Annie , Caillaud Jean M. , Friedman Samuel , Valteau Dominique , Lemerle Jean
Published: October 2008

Forty‐three infants under 1 year of age (median 4 months) with rhabdomyosarcoma (RMS), representing 11% of all childhood RMS seen over the same period, were treated and followed between 1955 and 1984 at our institute. Compared to the 340 older children (1‐16 years of age), there were no significant differences in male/female ratio, primary site, or clinical stage, but there was a higher frequency of alveolar and poorly differentiated histologic subtypes in infants aged under 1 year (P = 0.05 and P < 0.001, respectively) and increased frequency of botryoid RMS in older children (P < 0.02). Although children older than 1 year of age had a significantly higher complete remission rate (83% vs. 51%, P < 0.001), their 5 year overall survival (43%) was no different from that of infants under 1 year of age (35%). In the older group there was no survival difference between alveolar (38%) and nonalveolar (44%) histologic subtypes, but in infants younger than 1 year, alveolar subtype had a significantly poorer prognosis (13% vs. 47%, P = 0.01). Management of patients at this age group is difficult and major advances are needed to increase survival rates with a minimum of morbidity.
Permeability of the rhesus monkey oocyte membrane to water and common cryoprotectants
Authors: Karlsson Jens O.M. , Younis Abdelmoneim I. , Chan Anthony W.S. , Gould Kenneth G. , Eroglu Ali
Published: October 2008

Successful cryopreservation of oocytes of the rhesus monkey (Macaca mulatta) would facilitate the use of this valuable animal model in research on reproduction and development, while providing a stepping stone towards human oocyte cryopreservation and the conservation of endangered primate species. To enable rational design of cryopreservation techniques for rhesus monkey oocytes, we have determined their osmotic and permeability characteristics in the presence of dimethylsulfoxide (DMSO), ethylene glycol (EG), and propylene glycol (PROH), three widely used cryoprotectants. Using nonlinear regression to fit a membrane transport model to measurements of dynamic cell volume changes, we estimated the hydraulic conductivity (Lp) and cryoprotectant permeability (Ps) of mature and immature oocytes at 23.5°C. Mature oocyte membranes were most permeable to PROH (Ps = 0.56 ± 0.05 µm/sec) and least permeable to DMSO (Ps = 0.24 ± 0.02 µm/sec); the permeability to EG was 0.34 ± 0.07 µm/sec. In the absence of penetrating cryoprotectants, mature oocytes had Lp = 0.55 ± 0.05 µm/min/atm, whereas the hydraulic conductivity increased to 1.01 ± 0.10, 0.61 ± 0.07, or 0.86 ± 0.06 µm/min/atm when mature oocytes were exposed to DMSO, EG, or PROH, respectively. The osmotically inactive volume (Vb) in mature oocytes was 19.7 ± 2.4% of the isotonic cell volume. The only statistically significant difference between mature and immature oocytes was a larger hydraulic conductivity in immature oocytes that were exposed to DMSO. The biophysical parameters measured in this study were used to demonstrate the design of cryoprotectant loading and dilution protocols by computer‐aided optimization. Mol. Reprod. Dev. 76: 321–333, 2009. © 2008 Wiley‐Liss, Inc.
Molecular mechanisms regulating bovine ovarian follicular selection
Authors: Liu Zhilin , Youngquist Robert S. , Garverick H. Allen , Antoniou Eric
Published: October 2008

Transcription profiling of ovarian follicles. Understanding the mechanisms by which a single follicle is selected for further ovulation is important to control fertility in mammals. However, development of new treatments is limited by our poor understanding of molecular mechanisms regulating follicular selection. Our hypothesis is that genes involved in the control of cell proliferation and apoptosis are differentially regulated during follicular selection. Our objective was to identify these new genes. Bovine follicles were collected and gene expression levels were measured using microarrays. First, follicles were allocated to three groups, according to the time spent from the initiation of follicular wave to surgery (24 H, 36 H, and 48–60 H). Fifty‐seven genes are differentially expressed at a false discovery rate of 5%. These genes are involved in the control of lipid metabolism (P‐value = 0.0005), cell proliferation (0.007), cell death (0.003), cell morphology (0.003), and immune response (0.003). Follicles were also grouped into four categories, according to the expected time of deviation (early deviation; 8 mm, mid‐deviation; 8.5 mm, late deviation; 9 mm, dominant follicles; ≥10 mm). One hundred and twenty eight genes are differentially expressed between these four groups, including genes involved in cell proliferation (0.00002), cell death (0.0006), cell‐to‐cell signaling (0.003), cell morphology (0.003), lipid metabolism (0.0004), and immune response (0.00007). The expression levels of 10 genes were confirmed using quantitative real time PCR. As expected, we identified new differentially regulated genes involved in the control of cell growth and apoptosis. We also discovered a potential role for immune cells, and in particular macrophages, in follicular selection. Mol. Reprod. Dev. 76: 351–366, 2009. © 2008 Wiley‐Liss, Inc.
Staircase but not posttetanic potentiation in rat muscle after spinal cord hemisection
Authors: MacIntosh Brian R. , Smith Miles J. , Rassier Dilson E.
Published: October 2008

Spinal cord hemisection (SCH) results in atrophy of skeletal muscle and altered contractile properties. In this study our purpose was to assess staircase and posttetanic potentiation in the rat gastrocnemius muscle in situ, 1 week after SCH. Tetanic force was reduced by SCH, but twitch amplitude was not. The time course and magnitude of staircase during stimulation at 5 HZ (for 21 s) was similar in the control, sham‐operated, and SCH groups. However, posttetanic potentiation observed after 100‐, 500‐, and 1000‐ms tetanic (200 HZ) contractions was absent or drastically reduced after SCH. Twitch force increased 44 ± 8.7%, 47 ± 7.4%, and 15 ± 2.8% for the control, sham, and SCH groups, respectively, after the 1000‐ms tetanic contraction. After the 1000‐ms tetanic contraction, twitch active force decreased in all groups and was significantly reduced at 5 min relative to pretetanic twitch. In the control and sham groups, but not SCH, the active force recovered to the pretetanic level by 15 min. Resting regulatory light chain (RLC) phosphorylation was 15.4 ± 2.5% and 10.97 ± 3.3% for the control and SCH groups, respectively. After the 1‐s tetanic contraction, values were 41.6 ± 2.8% and 9.3 ± 2.9%, respectively. The potentiation observed in the SCH animals with 1000‐ms contraction apparently occurred without increases in RLC phosphorylation. One week after SCH there were clear changes in the contractile properties typically associated with prior activation. It is concluded that activity‐dependent potentiation can occur by a mechanism that is independent of RLC phosphorylation, and accelerated fatigue can mask the potentiating effects of prior activity. Muscle Nerve, 2008
Stiff‐person syndrome associated with multiple myeloma following autologous bone marrow transplantation
Authors: Clow Erin C. , Couban Stephen , Grant Ian A.
Published: October 2008

Stiff‐person syndrome (SPS) is an immunologically mediated central nervous system disorder that is infrequently associated with malignancy. We report a 31‐year‐old woman who developed SPS after autologous bone marrow transplantation and subsequent interferon treatment for multiple myeloma. Anti–glutamic acid decarboxylase (anti‐GAD) antibody serology was positive. The myeloma remains in remission 10 years posttransplant. SPS has been described in association with lung cancer and breast cancer, thymoma, and Hodgkin lymphoma. This is the second report of SPS in a patient with myeloma and the first description of SPS following autologous transplantation. Aberrant immune reconstitution is known to occur following hematopoietic progenitor cell transplantation. Interferon is also known to augment the immune response posttransplant. We speculate that an aberrant posttransplant immune response may have caused both the SPS and an autologous graft‐versus‐myeloma effect, resulting in prolonged remission posttransplant. Muscle Nerve, 2008
Appreciative inquiry: The why: The what? The how?
Authors: Moore Marian
Published: October 2008

‘Appreciative inquiry’ is the study and exploration of what gives life to human systems when they function at their best. This approach to personal change and organizational change is based on the assumption that questions and dialogue about strengths, successes, values, hope, and dreams are in themselves transformational. It is based on the belief that people, individually and collectively, have unique gifts, skills and contributions and that the organizations in which they work are human social systems where, through inquiry and dialogue, people can shift their attention and action away from problem analysis to identify worthy ideals and possibilities for the future. Copyright © 2008 John Wiley & Sons, Ltd.
Die Stapelfehlerenergie von Gold nach der τIII‐Methode Von
Authors: Ahlees M. , Haasen P.
Published: October 2008

Es wird die Stapelfehlerenergie γ von Gold an 30 Einkristallen nach der τIII‐Methode gemessen. Für 293 °K ergibt sich als Mittelwert γ = 13 erg/cm2 (32 erg/cm2 ≧ γ > 0). Die Ergebnisse werden mit denen anderer Meßmethoden verglichen und die Gründe für die große Unsicherheit bei Gold diskutiert. Weitere Verfestigungsparameter von Gold werden mitgeteilt.
Hall Effect in NiO
Authors: Nachman M. , Popescu F. G. , Rutter J.
Published: October 2008

The temperature and magnetic field dependence of the Hall effect in NiO polycrystalline samples, both below and above the Néel temperature (TN), were determined. The main experimental results are the following: (1) below TN the Hall e.m.f. decreases with increasing temperature, (2) above TN the Hall e.m.f. increases exponentially with temperature, (3) below TN the Hall coefficient (RH) decreases with increasing magnetic field and is constant above TN. Since below TN the magnetic properties of NiO have a non‐negligible influence on the Hall effect, the carrier mobility cannot be determined from Hall effect measurements by means of the usual formula in this temperature range. Above TN the mobility calculated in the usual way from RH exhibits an exponential rise with temperature, and this fact indicates that the hopping‐hole mechanism of conduction is dominant.
Electron Spin Resonance of NO in the Irradiated Ba(NO3)2 Single Crystal
Authors: Žďánský K. , Šroubek Z.
Published: October 2008

Electron spin resonance measurements are made on a single crystal of Ba(NO3)2 which has been X‐irradiated at 90 °K. The NO32−‐spectrum, with a hyperfine structure arising from a single nitrogen nucleus, is observed at 90 °K. The directions of the principal axes of the g‐tensors and hyperfine tensors and their eigenvalues are determined. The partially resolved super‐hyperfine structure assigned to an interaction with three Ba nuclei is also observed and compared with the super‐hyperfine structure of the NO32−‐spectrum in Pb(NO3)2.
Berechnung des Peierlspotentials im Diamantgitter Von
Authors: Labusch R.
Published: October 2008

Es wird eine erweiterte Form der Variationsmethode von Leibfried und Dietze verwendet, um das Peierlspotential für die Diamantstruktur zu berechnen. Wenn man nur die Wechselwirkung zwischen nächsten Nachbarn berücksichtigt, ist es möglich, das Peierlspotential der wichtigsten Versetzungsarten vollständig durch die Fouriertransformierte des Wechselwirkungspotentials auszudrücken. Es wird eine Methode entwickelt, die das Wechselwirkungspotential an die gemessenen Größen anzupassen gestattet. Ferner wird diskutiert, inwieweit das Peierlspotential durch diese Anpassung bestimmt ist. Als Beispiel wird die Theorie auf Schraubenversetzungen im Ge und Si angewandt. Die erhaltenen Werte für das Peierlspotential werden verwendet, um die Energien für die Kink‐Paarerzeugung zu berechnen. Es zeigt sich, daß sie annähernd dieselben Werte besitzen wie die gemessenen Aktivierungsenergien für die Bewegung von Versetzungen.
Untersuchung über die Gleichgewichtsformen von Zinkeinkristallen Von
Authors: Kaischew R. , Nanev Chr.
Published: October 2008

Es wird die experimentelle und theoretische Bestimmung der Gleichgewichtsformen von Zinkeinkristallen in Abhängigkeit von der Übersättigung behandelt. Zur Untersuchung des Wachstums der Zinkeinkristalle aus ihrer eigenen Dampfphase wird eine Apparatur beschrieben, die es ermöglicht, störende Keimbildung bei größeren Übersättigungen zu vermeiden. Dadurch war es möglich, eine Übersättigungsschwelle – gemessen als eine Temperaturdifferenz ΔT1= 7,5 ± 0,5 °C zwischen dem wachsenden Einkristall und dem verdampfenden Zinkvorrat – nachzuweisen, oberhalb derer die Flächen {1012} und {1120} in der Gleichgewichtsform nicht mehr auftreten. Dieses Versuchsergebnis wird vom Standpunkt der Kristallwachstumstheorie nach Stranski und Kaischew diskutiert. Man erhält unter der Annahme, daß die Bindungsenergie zwischen den Bausteinen des Kristallgitters eine Potenzfunktion des reziproken Atomabstandes ist, als Exponentndieser Funktion. den Wert 7,5 ± 0,3. Mit diesem Wert wird die Temperaturdifferenz ΔT2= 2,1 ± 0,3 °C berechnet, unterhalb welcher in der Gleichgewichtsform des Zinks noch zusätzlich die Flächen {1121} und {1122} erscheinen müssen.
Exciton and Low‐Energy Interband Structures in SrO and BaO
Authors: Kearney R. J. , Cottini M. , Grilli E. , Baldini G.
Published: October 2008

Optical reflectivity data are given in the energy region 3.5 to 10 eV on freshly cleaved single crystals of SrO and BaO. The main exciton structures are interpreted in terms of two different k‐space excitations one at the zone center, the other at the edge X. Also fine structure near the SrO exciton doublet is observed.
Hartree‐Fock Calculation of Point Defects in Li Clusters
Authors: Stoll H. , Preuss H.
Published: October 2008

SCF‐MO‐Lcgo calculations have been performed for Li35 clusters of b.c.c.‐structure. The introducing of vacancies and Be‐impurities, respectively, and the relaxation of the neighbour atoms are discussed. Reasonable agreement is found between the energy for complete removal of an inner cluster atom and the experimental formation energy of a vacancy in solid Li.
Temperature Dependence of the Absorption Edge in Crystalline and Vitreous As2S3
Authors: Zakis J. R. , Fritzsche H.
Published: October 2008

Optical absorption below and near the interband absorption edge has been measured from helium temperatures up to the molten state of As2S3 Irreversible changes in absorption below the band edge suggest that heating above 530 K produces defect states in crystalline As2S3. The exponential absorption tail and thus the absorption edge is temperature independent t o about 200K. Between 300 and 400K it decreases a t a rate of about 1.6 × 10−3, eV/K. This temperature dependence is predominantly caused by electron‐phonon interaction.
Model for Brillouin Scattering in Amorphous Solids
Authors: Martin A. J. , Brenig W.
Published: October 2008

An elastic continuum model is presented for Brillouin scattering by an amorphous solid. The assumption that light scatters on distorted plane wave acoustic phonons leads to the prediction that the scattered intensity plotted as a function of the frequency transfer Ωo consists of the usual Brillouin peaks plus a background which, a t room temperature, goes like Ωo; for small Ωo, but rises less steeply for larger Ωo, and may even bend over within the range of the validity of the model, depending on the correlation lengths for spatial fluctuations due to disorder and on the speeds of sound. For the case of a‐Si, additional results are obtained with the help of existing experimental measurements.
Existence and Binding Energy of the Excitonic Ion
Authors: Munschy G. , Stébé B.
Published: October 2008

It is shown that the excitonic ion should be stable for any value of the electron to hole effective mass ratio u. An accurate calculation of the binding energy is also performed, in excellent agreement with the values previously obtained in the limiting cases σ = 0 and σ = 1. In particular, the involved binding energy in copper halides is large enough to lead to an observable effect.
Bulk models of solar radiation at sea
Authors: Dobson Fred W. , Smith Stuart D.
Published: October 2008

With a view to improving climate prediction, we test various models for estimating solar radiation at sea from standard meteorological surface observations against long series of radiation measurements at several Ocean Weather Stations and at an offshore island meteorological station. The widely‐used Budyko formula is found to err by up to 32% in estimating long‐term mean insolation, and has even larger errors in reproducing seasonal variations. Various models which estimate solar radiation from solar elevation and from hourly cloud amount and type, using empirical or simple physical formulae, are evaluated. None of these models estimate mean insolation better than an existing formula which relies only on noon solar elevation and daily mean cloud amount, although the hourly models do reproduce seasonal, monthly and daily variations better. None of the formulae using standard surface observations is able to achieve the 10 Wm−2 accuracy in long‐term mean insolation which is required for climate prediction.
Drop‐size distributions of raindrops by polarization radar and simultaneous measurements with disdrometer, windprofiler and PMS probes
Authors: Richter Carolin , Hagen Martin
Published: October 2008

Multiparameter polarimetric weather radars offer the possibility of estimating raindrop size distribution directly. the retrieved parameters of exponential drop‐size distributions are compared with discrete drop‐size spectra obtained from a vertical‐pointing radar (windprofiler type), airborne particle measuring systems (PMS) probes and a disdrometer. the windprofiler and PMS probes allow simultaneous measurements at almost the same location. This unique data set shows that radar‐estimated drop‐size distributions can be retrieved with the same quality as distributions from other standard instruments. Results obtained with a C‐band radar during the CLEOPATRA (Cloud Experiment Oberpfaffenhofen and Transports) campaign in southern Germany are confirmed by measurements with an S‐band radar in southern England. the quality of the estimated rain rate is high, but differences in quantity can be caused not only by differences in the instrumental set‐up but also by deviation from an exponential shape of the drop‐size distribution.
Sensitivity analysis of atmospheric low‐frequency variability
Authors: Corti S. , Palmer T. N.
Published: October 2008

The sensitivity of the Pacific‐North‐American (PNA) pattern and the North‐Atlantic Oscillation (NAO) pattern to small perturbations is investigated using adjoint techniques. Analysis is perfomed on integrations of a quasi‐geostrophic (QG) model whose internal low‐frequency variability is realistic. Specifically, the sensitivity of the QG‐model PNA and NAO patterns have been made from a large set of five‐day integrations of the adjoint of the QG‐model, linearized about time‐varying basic‐state solutions of the model. the sensitivity perturbations are initially located well upstream of the pattern of low‐frequency variability and propagate downstream by wave dynamics, gaining energy through both barotropic and baroclinic processes. For the PNA pattern, it was found that variations in sensitivity were associated with fluctuations in the strength of the jet across the North Pacific. For the NAO pattern, it was found that fluctuations in sensitivity were correlated with the strength of the PNA pattern, the more sensitive NAO basic states having negative PNA index. This analysis has identified fairly distinct paths in phase space associated with predictable and unpredictable transitions, qualitatively similar to that found in the three‐component Lorenz model.

Predictability of climate‐change problems is also investigated. the results from four different climate integrations in which an additional time‐invariant forcing is added to the model equations are presented. QG simulations show that the influence of a forcing proportional to the mean sensitivity pattern induces a stronger change in the probability distribution of the PNA pattern than an equivalent amplitude forcing which directly projects onto the PNA pattern itself.
A general semi‐lagrangian advection scheme employing forward trajectories
Authors: Sun Wen‐Yih , Yeh Kao‐San
Published: October 2008

We propose a semi‐Lagrangian advection scheme using forward trajectories, and a general interpolation procedure from the irregularly distributed Lagrangian grid to the regularly distributed Eulerian grid. the general interpolation procedure has virtually no restrictions, and the advection scheme is absolutely stable due to the direct calculation of forward trajectories. They are, therefore, applicable to problems of any extent of deformation with arbitrary Courant numbers. the scheme is also quite efficient, because this interpolation procedure converts a two‐dimensional problem into a sequence of one‐dimensional problems by employing an intermediate grid. the slotted cylinder of Zalesak under the motion of solid‐body rotation is tested to assess the accuracy of this ‘internet interpolation method’. the idealized cyclogenesis of Doswell is simulated to demonstrate the ability of the advection scheme to accommodate strong deformation flows. Both tests indicate satisfactory accuracy.
Estimation of potential‐temperature gradient in turbulent stable layers using acoustic sounder measurements
Authors: Helmis C. G. , Kalogiros J. A. , Asimakopoulos D. N. , Soilemes A. T.
Published: October 2008

The intensity of acoustic backscatter from a monostatic acoustic sounder is used to compute the profile of the temperature structure parameter C. The average value of C in low‐height turbulent stable layers (temperature inversions) is used to infer the local potential‐temperature gradient. The estimates of temperature jump in the first height inversion at the top of the unstable atmospheric boundary layer (ABL) are compared with the direct measurements of the temperature profile by a tethered balloon, and the indirect estimation from the wave period of the waves present on the inversion. The agreement of the estimations with the direct measurements is satisfactory (at least a 0.4 degC accuracy). Also, the‐4/3 similarity law of the C profile in the unstable ABL is used to obtain estimates of the surface heat flux, Qo. The comparison of these estimates of Qo with eddy correlation measurements shows the high accuracy of this method. This direct connection of the C profile with Qo can also be used to calibrate the backscatter intensity.
Convective destabilization by upper‐level troughs
Authors: Juckes Martin , Smith Roger K.
Published: October 2008

The approach of an upper‐level trough is accompanied by a local ascent of the isentropic surfaces in the troposphere. The associated cooling and moistening destabilizes the atmosphere to convection. In this paper we attempt to quantify the maximum amount of destabilization as a function of the amplitude and horizontal scale of the trough. The trough is represented by an elongated potential‐temperature perturbation on the tropopause. Its structure, including the isentrope displacement it produces, is calculated from the balanced shear‐line solutions of Juckes. These solutions are used to estimate the amount by which mid‐ and lower‐tropospheric air masses are lifted when an upper‐tropospheric trough passes overhead on the assumption that isentropic potential‐vorticity anomalies are localized in the upper troposphere. The amount of destabilization is characterized by the maximum change in convective available potential energy (CAPE) and convective inhibition (CIN) brought about by the passage of the trough. The calculations seek to isolate one aspect of the interaction between an upper‐level trough and a tropical cyclone. We show that the changes in CAPE are significant in the Tropics (up to 83% for the soundings examined) and even more so in the middle latitudes (up to 130%) and that the CIN may be completely removed.
The oceanic mesoscale convective system and associated mesovortex observed 12 December 1992 during TOGA‐COARE
Authors: Bousquet Olivier , Chong Michel
Published: October 2008

This study documents the precipitation and kinematic structure of a mature/mature‐to‐decaying, westward propagating, near‐equatorial oceanic mesoscale convective system (MCS) observed by airborne Doppler radars during TOGA‐COARE, the Tropical Ocean/Global Atmosphere Coupled Ocean‐Atmosphere Response Experiment. This system occurred on 12 December 1992 during the convectively active phase of an intraseasonal oscillation, and was followed, at its dissipating stage, by a redevelopment of convection that led to the MCS observed on 13 December 1992. These two successive MCSs were associated with a two‐day atmospheric disturbance. Radar‐deduced airflows at two time periods reveal many similarities with other tropical oceanic cloud clusters. In particular, a marked rear inflow jet associated with a midlevel cyclonic mesovortex was observed within the rear of the stratiform region.

The mesovortex was better defined both in size and depth during the mature‐to‐decaying stage and was located more inside the system within a region of convergence, due to the westward propagation of the rear inflow. Countergradient transports of momentum normal to the mean orientation of the system at midlevels, and downgradient transports at lower and higher levels helped to intensify this rear inflow. These transports were mostly accomplished by eddy structures. Cyclonic vorticity was concentrated at the rear of the MCS and peaked at the centre of the observed closed wind circulation. As previously observed, stretching of the pre‐existing vertical vorticity was the dominant dynamical mechanism which helped to amplify the mesovortex at mid‐to‐upper levels, while tilting of the horizontal vorticity into the vertical was a lesser mechanism and had an opposite effect. In most respects, advective processes were negatively correlated with the stretching and tilting mechanisms, but not sufficiently to be balanced. The resulting tendency was an increase of cyclonic vorticity at low‐to‐mid levels and a net decrease above.
Direct Observation of the Transition Point Between Quasi‐Spherical and Cubic Nanoparticles in a Two‐Step Seed‐Mediated Growth Method
Authors: Dovgolevsky Ekaterina , Haick Hossam
Published: October 2008

An aqueous seed‐mediated growth method is adapted to explore the shape transformation of quasi‐spherical Au seeds to nanocubes in a direct and continuous manner. Quenching the growth process at varied reaction‐duration times and exploring the intermediate products by high‐resolution transmission electron microscopy and UV/vis spectroscopy shows an abrupt cuboctahedral‐to‐nanocube transition at 25–27 nm without any change in the nanoparticle size. The size of the obtained nanocubes remains constant (25–27 nm) until most (>90%) of the cuboctahedral nanoparticles are transformed to nanocubes. At this point, the (25–27 nm) nanocubes initiate further continuous and homogeneous growth until they reach 50‐nm Au cubes. These observations are ascribed to a scenario in which the kinetically controlled growth mode of the nanoparticle is significantly affected by the surface self‐diffusion of metal adatoms, especially when the adatom's self‐diffusion distance is comparable with the nanoparticle's size.
Selective serotonin reuptake inhibitor (SSRI) modulation of striatal dopamine measured with [11C]‐raclopride and positron emission tomography
Authors: Smith Gwenn S. , Ma Yilong , Dhawan Vijay , Chaly Thomas , Eidelberg David
Published: October 2008

The effect of a pharmacologic increase in serotonin concentrations on striatal dopamine (D2) receptor availability has been measured in several studies using positron emission tomography (PET) and the radiotracer [11C]‐raclopride as a method for the in vivo imaging of serotonin modulation of striatal dopamine in human subjects. These studies have shown that an acute increase in serotonin concentrations produced a decrease in striatal D2 receptor availability. The current study was undertaken to measure the effects of a more pharmacologically selective serotonergic agent compared to previous studies, the serotonin reuptake inhibitor, citalopram, on striatal D2 receptor availability. Twelve healthy control subjects underwent two PET scans performed on the same day following i.v. administration of saline (Scan 1) and citalopram (Scan 2, 40 mg, i.v.). The [11C]‐raclopride data were analyzed with a graphical analysis method using the cerebellum as the input function. Plasma levels of citalopram, cortisol, and prolactin were measured. The citalopram concentrations peaked at the end of infusion (EOI) and remained relatively consistent from 30 min to 3 h postinfusion. An increase in cortisol and prolactin concentrations was observed from the EOI until 60 min after the EOI. A significant decrease in striatal D2 receptor availability was observed after citalopram infusion (−5%), presumably due to an increase in endogenous dopamine concentrations. In summary, i.v. administration of the selective serotonin reuptake inhibitor, citalopram, produced modest reductions in striatal D2 receptor availability, consistent with other human [11C]‐raclopride studies using less pharmacologically selective serotonergic agents. Synapse 63:1–6, 2009. © 2008 Wiley‐Liss, Inc.
Role of prefrontal dopaminergic neurotransmission in glucocorticoid receptor‐mediated modulation of methamphetamine‐induced hyperactivity
Authors: Ago Yukio , Arikawa Shinsuke , Yata Miyuki , Yano Koji , Abe Michikazu , Takuma Kazuhiro , Matsuda Toshio
Published: October 2008

Glucocorticoids are involved in psychostimulant‐induced hyperactivity, but the exact mechanism is not known. This study used the selective glucocorticoid receptor antagonist, RU‐43044, to determine whether prefrontal neurotransmission is involved in glucocorticoid‐mediated modulation of methamphetamine (METH)‐induced hyperactivity in mice. Pretreatment with RU‐43044 (10–30 mg/kg) attenuated the increased spontaneous locomotor activity induced by METH (1–2 mg/kg). The psychostimulant effect of METH was also attenuated by adrenalectomy. RU‐43044 inhibited METH‐induced increases in extracellular dopamine (DA), but not serotonin (5‐HT), levels in the prefrontal cortex, but did not affect METH‐induced increases in extracellular DA levels in the nucleus accumbens shell, although it inhibited increases in extracellular 5‐HT levels. Adrenalectomy also attenuated the METH‐induced increases in extracellular DA levels in the prefrontal cortex. RU‐43044 did not affect METH‐induced increases in plasma corticosterone levels. These findings suggest that glucocorticoid receptors are involved in METH‐induced hyperactivity, and that prefrontal dopaminergic neurotransmission plays a role in glucocorticoid‐mediated modulation of METH‐induced behavioral changes. Synapse 63:7–14, 2009. © 2008 Wiley‐Liss, Inc.
Clozapine inhibits development and expression of nicotine‐induced locomotor sensitization in rats
Authors: Kayir Hakan , Goktalay Gokhan , Yildirim Murat , Uzbay Tayfun I.
Published: October 2008

It has been shown that clozapine, the prototype of atypical antipsychotics, significantly reduces daily cigarette use and alcohol consumption in schizophrenic patients. However, our knowledge about the effect of clozapine on nicotine abuse is limited. Aim of this study was to determine whether clozapine would inhibit the development and expression of nicotine‐induced locomotor sensitization in rats. To investigate the effect of clozapine on the development of nicotine‐induced locomotor sensitization, rats were pretreated with clozapine (2.5–10 mg/kg) 30 min before the nicotine (0.5 mg/kg), and locomotor activity was recorded for 15 min. This procedure was repeated every day for eight sessions. After a 3‐day drug‐free period, rats were challenged with nicotine (0.5 mg/kg). To reveal effect of clozapine on the expression of nicotine‐induced locomotor sensitization, rats were injected with nicotine for eight sessions. After a 3‐day drug‐free period, rats were pretreated with clozapine (2.5–10 mg/kg) or vehicle 30 min before the nicotine (0.5 mg/kg) challenge injection. Repeated administration of nicotine generated robust locomotor sensitization in rats. Clozapine pretreatment (2.5–10 mg/kg) blocked the development and the expression of nicotine‐induced locomotor sensitization in rats. Our results suggest that atypical antipsychotic clozapine can prevent the effects of nicotine in an animal model of dependence, which represents early adaptations in initiation and continuation of addictive behavior. Synapse 63:15–21, 2009. © 2008 Wiley‐Liss, Inc.
Identification of the arginine/ornithine antiporter ArcD from Halobacterium salinarum
Authors: Wimmer Florian , Oberwinkler Tanja , Bisle Birgit , Tittor Jörg , Oesterhelt Dieter
Published: October 2008

This paper identifies the first arginine/ornithine antiporter ArcD from the domain of archea. The functional role of ArcD is demonstrated by transport assays with radioactive labelled arginine, by its necessity to enable arginine fermentation under anaerobic growth conditions and by the consumption of arginine from the medium during growth. All three experimentally observables are severely disturbed when the deletion strain ΔArcD is used. The isolated protein is verified by mass spectrometry and reconstituted in vesicles. The proteoliposomes are attached to a membrane and capacitive currents are recorded which appear upon initiation of the transport process by change from arginine‐free to arginine‐containing buffer. This clearly demonstrates that the purified 34 kD protein is the functional unit.
TPPP orthologs are ciliary proteins
Authors: Orosz Ferenc , Ovádi Judit
Published: October 2008

Tubulin polymerization promoting protein, (TPPP/p25), was identified as a brain‐specific protein. The potential function of this protein resembled that of MAPs. It is mainly expressed in oligodendrocytes; however, immunopositivity was also detected in glial and neuronal inclusions in synucleinopathies. Here, we show that TPPP gene(s) are conserved in the genomes of ciliated organisms, but are lacking from the nonciliated ones. This recognition is based upon homologous gene sequence analysis, in silico comparative genomic studies, bioinformatic search and experimental evidence. Cilia (flagella) are microtubule‐based cellular extensions of sensory and/or motile function. TPPP orthologs are among the only 16 genes that can be found in all ciliated organisms, suggesting that TPPP orthologs may be associated with a basic function of cilia.