bluuebunny/crossref_metadata_2025 huggingface dataset:
Temperature‐Respiration Relationships Differ in Mycorrhizal and Non‐Mycorrhizal Root Systems of Picea abies (L.) Karst.
Authors: Koch N. , Andersen C. P. , Raidl S. , Agerer R. , Matyssek R. , Grams T. E. E.
Published: July 2007

Abstract: Root respiration has been shown to increase with temperature, but less is known about how this relationship is affected by the fungal partner in mycorrhizal root systems. In order to test respiratory temperature dependence, in particular Q10 of mycorrhizal and non‐mycorrhizal root systems, seedlings of Picea abies (L.) Karst. (Norway spruce) were inoculated with the ectomycorrhizal fungus Piloderma croceum (Eriksson and Hjortstam, SR430; synonym: Piloderma fallax: [Libert] Stalpers) and planted in soil respiration cuvettes (mycocosms). Temperature dependence of hyphal respiration in sterile cultures was determined and compared with respiration of mycorrhizal roots. Respiration rates of mycorrhizal and non‐mycorrhizal root systems as well as sterile cultures were sensitive to temperature. Q10 of mycorrhizal root systems of 3.0 ± 0.1 was significantly higher than that of non‐mycorrhizal systems (2.5 ± 0.2). Q10 of P. croceum in sterile cultures (older than 2 months) was similar to that of mycorrhizal root systems, suggesting that mycorrhizae may have a large influence on the temperature sensitivity of roots in spite of their small biomass. Our results stress the importance of considering mycorrhization when modeling the temperature sensitivity of spruce roots.
The Impact of Ozone on Juvenile Maize (Zea mays L.) Plant Photosynthesis: Effects on Vegetative Biomass, Pigmentation, and Carboxylases (PEPc and Rubisco)
Authors: Leitao L. , Bethenod O. , Biolley J.‐P.
Published: July 2007

Abstract: The impact of ozone on crops was more studied in C3 than in C4 species. In C3 plants, ozone is known to induce a photosynthesis impairment that can result in significant depressions in biomass and crop yields. To investigate the impact of O3 on C4 plant species, maize seedlings (Zea mays L. cv. Chambord) were exposed to 5 atmospheres in open‐top chambers: non‐filtered air (NF, 48 nL L‐1 O3) and NF supplied with 20 (+ 20), 40 (+ 40), 60 (+ 60), and 80 (+ 80) nL L‐1 ozone. An unchambered plot was also available. Leaf area, vegetative biomass, and leaf dry mass per unit leaf area (LMA) were evaluated 33 days after seedling emergence in OTCs. At the same time, photosynthetic pigments as well as carboxylase (PEPc and Rubisco) activities and amounts were also examined in the 5th leaf. Ozone enhanced visible symptoms characterizing foliar senescence. Across NF, + 20, + 40, and + 60 atmospheres, both chlorophylls and carotenoids were found to be linearly decreased against increasing AOT40 (ca. ‐ 50 % in + 60). No supplementary decrease was observed between + 60 and + 80. Total above‐ground biomass was reduced by 26 % in + 80 atmosphere; leaf dry matter being more depressed by ozone than leaf area. In some cases, LMA index was consistent to reflect low negative effects caused by a moderate increase in ozone concentration. PEPc and Rubisco were less sensitive to ozone than pigments: only the two highest external ozone doses reduced their activities by about 20 ‐ 30 %. These changes might be connected to losses in PEPc and Rubisco proteins that were decreased by about one‐third. The underlying mechanisms for these results were discussed with special reference to C3 species. To conclude, we showed that both light and dark reactions of C4 photosynthesis can be impaired by realistic ozone doses.
The nonlinear effect from the interplay between the nonlinearity and the supercollimation of photonic crystal
Authors: Jiang Xunya , Zhou Chuanhong , Yu Xiaofang , Fan Shanhui , Soljačić Marin , Joannopoulos J. D.
Published: July 2007

The authors theoretically and numerically investigate the beam propagation near the supercollimation frequency ωs0 in a photonic crystal made of nonlinear material. Since the value and sign of the equal-frequency-contour curvature which dominates the beam behaviors can be nonlinearly tuned near ωs0, a kind of nonlinear effect is generated. The envelope equation with unique form is also obtained. Beam-control mechanisms are theoretically predicted and observed in numerical experiments, such as tunable collimation, tunable beam-divergence angle, and self-lock of collimation. These mechanisms can be utilized to function as fiber, lens and coupler, or to design photonic devices.
Ultrafast-based projection-reconstruction three-dimensional nuclear magnetic resonance spectroscopy
Authors: Mishkovsky Mor , Kupče Eriks , Frydman Lucio
Published: July 2007

Recent years have witnessed increased efforts toward the accelerated acquisition of multidimensional nuclear magnetic resonance (nD NMR) spectra. Among the methods proposed to speed up these NMR experiments is “projection reconstruction,” a scheme based on the acquisition of a reduced number of two-dimensional (2D) NMR data sets constituting cross sections of the nD time domain being sought. Another proposition involves “ultrafast” spectroscopy, capable of completing nD NMR acquisitions within a single scan. Potential limitations of these approaches include the need for a relatively slow 2D-type serial data collection procedure in the former case, and a need for at least n high-performance, linearly independent gradients and a sufficiently high sensitivity in the latter. The present study introduces a new scheme that comes to address these limitations, by combining the basic features of the projection reconstruction and the ultrafast approaches into a single, unified nD NMR experiment. In the resulting method each member within the series of 2D cross sections required by projection reconstruction to deliver the nD NMR spectrum being sought, is acquired within a single scan with the aid of the 2D ultrafast protocol. Full nD NMR spectra can thus become available by backprojecting a small number of 2D sets, collected using a minimum number of scans. Principles, opportunities, and limitations of the resulting approach, together with demonstrations of its practical advantages, are here discussed and illustrated with a series of three-dimensional homo- and heteronuclear NMR correlation experiments.
Efficient configuration selection scheme for vibrational second-order perturbation theory
Authors: Yagi Kiyoshi , Hirata So , Hirao Kimihiko
Published: July 2007

A fast algorithm of vibrational second-order Møller-Plesset perturbation theory is proposed, enabling a substantial reduction in the number of vibrational self-consistent-field (VSCF) configurations that need to be summed in the calculations. Important configurations are identified a priori by assuming that a reference VSCF wave function is approximated well by harmonic oscillator wave functions and that fifth- and higher-order anharmonicities are negligible. The proposed scheme has reduced the number of VSCF configurations by more than 100 times for formaldehyde, ethylene, and furazan with an error in computed frequencies being not more than a few cm−1.
Energy conservation and unitary approximation numbers
Authors: Huhtanen Marko
Published: July 2007

The role of unitary operators is central in mathematics, in questions related to energy conservation in physics, as well as in stable computations in numerical linear algebra and scientific simulations. In this paper a refined way to measure the deviation from unitary operators is proposed for matrices in terms of so-called unitary approximation numbers. These describe how far an operator is from being unitary, i.e., energy conserving modulo small rank perturbations.
Guiding-center simulations of nonlocal and negative inertia effects on rotation in a tokamak
Authors: Kurki-Suonio T. , Heikkinen J. A. , Lashkul S. I.
Published: July 2007

The magnitude of the radial electric field (Er), resulting from nonambipolar fluxes of neoclassical origin, is evaluated using Monte Carlo guiding-center simulations for a low-current plasma corresponding to the FT-2 tokamak {Fisichiskii Tokamak-2, Ioffe Institute, St. Petersburg [S. I. Lashkul, V. N. Budnikov, E. O. Vekshina et al., Plasma Phys. Rep. 27, 1001 (2001)]}. The Er-values are found to significantly exceed those given by the standard neoclassical theory, based on thin-orbit assumption, when the plasma current is sufficiently low and the pressure gradient is sufficiently high. Strong Er-structures are found to form in the same low plasma-current range where enhanced confinement is reported in the FT-2 tokamak. In the simulations, the physics behind the strong increase in the field values is intimately related to the poloidal Mach-number, together with the wide ion orbits.
Evolution of the onset of coherence in a family of photonic crystal nanolasers
Authors: Choi Y.-S. , Rakher M. T. , Hennessy K. , Strauf S. , Badolato A. , Petroff P. M. , Bouwmeester D. , Hu E. L.
Published: July 2007

The authors report on the systematic variation of the onset of lasing in high-β photonic crystal nanolasers. A series of nanocavities has been designed to systematically approach the high-β devices by controlling the number of modes in the s-shell spectrum of InAs quantum dots at 4K. The lasing action is confirmed by the observation of coherent-state transition to Poissonian photon statistics. The quantitative analysis reveals the high β of 0.69, 0.44, and 0.19 for the nanocavities with one, two, and three modes, respectively. By mapping the observed lasing transitions to β factors, the authors demonstrate the interplay of β and lasing performance.
Comment on “Removable singularities for solutions of coupled Yang-Mills-Dirac equations” [J. Math. Phys. 47, 103502 (2006)]
Authors: Otway Thomas H.
Published: July 2007

A lemma from elliptic theory is used to improve a recent result by Li [J. Math. Phys. 47, 103502 (2006)] concerning the removability of an isolated point singularity from solutions of the coupled Yang-Mills-Dirac equations.
Nonlinear dielectric behavior in three-component ferroelectric superlattices
Authors: Sarkar A. , Ranjith R. , Krupanidhi S. B.
Published: July 2007

Three-component ferroelectric superlattices consisting of alternating layers of SrTiO3, BaTiO3, and CaTiO3 (SBC) with variable interlayer thickness were fabricated on Pt(111)/TiO2/SiO2/Si (100) substrates by pulsed laser deposition. The presence of satellite reflections in x-ray-diffraction analysis and a periodic concentration of Sr, Ba, and Ca throughout the film in depth profile of secondary ion mass spectrometry analysis confirm the fabrication of superlattice structures. The Pr (remnant polarization) and Ps (saturation polarization) of SBC superlattice with 16.4-nm individual layer thickness (SBC16.4) were found to be around 4.96 and 34 μC/cm2, respectively. The dependence of polarization on individual layer thickness and lattice strain were studied in order to investigate the size dependence of the dielectric properties. The dielectric constant of these superlattices was found to be much higher than the individual component layers present in the superlattice configuration. The relatively higher tunability (∼55%) obtained around 300 K indicates that the superlattice is a potential electrically tunable material for microwave applications at room temperature. The enhanced dielectric properties were thus discussed in terms of the interfacial strain driven polar region due to high lattice mismatch and electrostatic coupling due to polarization mismatch between individual layers.
Enhancement of magnetocaloric effects in La1−zPrz(Fe0.88Si0.12)13 and their hydrides
Authors: Fujieda S. , Fujita A. , Fukamichi K.
Published: July 2007

The magnetocaloric effects (MCEs) in La1−zPrz(Fe0.88Si0.12)13 and their hydrides have been investigated. The values of the MCEs due to the itinerant-electron metamagnetic transition are enhanced significantly by a partial substitution of Pr for La. Furthermore, the Curie temperature TC of the La1−zPrz(Fe0.88Si0.12)13 is controlled by adjusting the absorption content of hydrogen in a similar manner as La(Fe0.88Si0.12)13. For the compounds having almost the same TC, the MCEs in the La1−zPrz(Fe0.88Si0.12)13Hy are larger than those in La(Fe0.88Si0.12)13Hy. To conclude, the La1−zPrz(Fe0.88Si0.12)13 and their hydrides are more useful for magnetic refrigerants working in a wide temperature range covering room temperature.
Terahertz photomixing in high energy oxygen- and nitrogen-ion-implanted GaAs
Authors: Cámara Mayorga I. , Michael E. A. , Schmitz A. , van der Wal P. , Güsten R. , Maier K. , Dewald A.
Published: July 2007

In this letter, the authors elaborate a detailed study of ion-implanted GaAs terahertz photomixers. The authors implanted several GaAs samples with oxygen and nitrogen ions with energies between 2 and 3MeV and doses ranging from 2×1011to3×1013cm−2. The samples were processed by patterning metal-semiconductor-metal structures on the feed point of self-complementary log-periodic spiral broadband antennas. From dc measurements and analysis of frequency roll-off in the 100GHz–1THz range under variable bias conditions, the authors studied systematically the carrier trapping time, terahertz power, and photocurrent dependence on applied voltage and frequency for the different samples.
Long-time self-diffusion of charged colloidal particles: Electrokinetic and hydrodynamic interaction effects
Authors: McPhie Mathieu G. , Nägele Gerhard
Published: July 2007

The authors analyze the long-time self-diffusion of charge-stabilized colloidal macroions in nondilute suspensions using a mode-coupling scheme developed for multicomponent suspensions of interacting Brownian spheres. In this scheme, all ionic species, including counterions and electrolyte ions, are treated on an equal footing as charged hard spheres undergoing overdamped Brownian motion. Hydrodynamic interactions between all ions are accounted for on the far-field level. We show that the influence on the colloidal long-time self-diffusion coefficient arising from the relaxation of the microionic atmosphere surrounding the colloids, the so-called electrolyte friction effect, is usually insignificant in comparison with the friction contributions arising from direct and hydrodynamic interactions between the colloidal particles. This finding is true even for small colloid concentrations unless the mobility difference between colloidal particles and microions is not large. Furthermore, we observe an interesting nonmonotonic density dependence of the colloidal long-time self-diffusion coefficient in suspensions with low amount of added salt. We show that this unusual density dependence is due to colloid-colloid hydrodynamic interactions.
Aging effect and large recoverable electrostrain in Mn-doped KNbO3-based ferroelectrics
Authors: Feng Zuyong , Ren Xiaobing
Published: July 2007

K Nb O 3 -based ferroelectrics have drawn much attention in recent years owing to their good piezoelectric performance among Pb-free piezoelectrics. However, little is known about the aging effect of these materials. In the present study, the authors systematically studied the aging effect of a Mn-doped (K0.99Li0.01)(Nb0.65Ta0.35)O3 ceramic with an aim to find an aging-induced recoverable electrostrain effect based on a reversible domain switching mechanism. They found that aging in the ferroelectric state made the otherwise normal hysteresis loop into a double loop, and more interestingly the aged sample demonstrated a large recoverable electrostrain of 0.125% at 4kV∕mm in an unpoled state. Such a behavior persisted up to 140°C and showed good recoverability. The aging-induced double hysteresis and recoverable electrostrain suggest a reversible domain switching mechanism due to a symmetry-conforming short-range ordering of point defects. The striking similarity of the aging effect between acceptor-doped A+B5+O3 and acceptor-doped A2+B4+O3 systems indicates a common physical origin of aging.
Effects of metal gate-induced strain on the performance of metal-oxide-semiconductor field effect transistors with titanium nitride gate electrode and hafnium oxide dielectric
Authors: Kang Chang Yong , Choi Rino , Hussain M. M. , Wang Jinguo , Suh Young Jun , Floresca H. C. , Kim Moon J. , Kim Jiyoung , Lee Byoung Hun , Jammy Raj
Published: July 2007

In this letter, the authors investigate the strain induced by titanium nitride (TiN) electrode and effective work function (EWF) tuning for metal-oxide-semiconductor field effect transistors (MOSFETs). Scaling of TiN thickness was found to be effective both in increasing tensile stress on Si substrates and in lowering the EWF of metal gate n-MOSFETs. The device with 3nm TiN as a gate electrode showed favorable threshold voltage (Vth) for n-MOSFETs as well as higher channel electron mobility by 17% compared to the device with 20nm TiN film.
Efficient Monte Carlo sampling by parallel marginalization
Authors: Weare Jonathan
Published: July 2007

Markov chain Monte Carlo sampling methods often suffer from long correlation times. Consequently, these methods must be run for many steps to generate an independent sample. In this paper, a method is proposed to overcome this difficulty. The method utilizes information from rapidly equilibrating coarse Markov chains that sample marginal distributions of the full system. This is accomplished through exchanges between the full chain and the auxiliary coarse chains. Results of numerical tests on the bridge sampling and filtering/smoothing problems for a stochastic differential equation are presented.
ppGpp regulation of RpoS degradation via anti-adaptor protein IraP
Authors: Bougdour Alexandre , Gottesman Susan
Published: July 2007

IraP is a small protein that interferes with the delivery of σ
S
(RpoS) to the ClpXP protease by blocking the action of RssB, an adaptor protein for σ
S
degradation. IraP was previously shown to mediate stabilization of σ
S
during phosphate starvation. Here, we show that
iraP
is transcribed in response to phosphate starvation; this response is mediated by ppGpp. The
iraP
promoter is positively regulated by ppGpp, dependent on the discriminator region of the
iraP
promoter. Sensing of phosphate starvation requires SpoT but not RelA. The results demonstrate a target for positive regulation by ppGpp and suggest that the cell use of ppGpp to mediate a variety of starvation responses operates in part by modulating σ
S
levels.
Activity of ketoconazole against Mycobacterium tuberculosis
in vitro and in the mouse model
Authors: Byrne Sean T. , Denkin Steven M. , Gu Peihua , Nuermberger Eric , Zhang Ying
Published: July 2007

There is an urgent need for the development of new drugs that are active against drug-resistant Mycobacterium tuberculosis strains and can shorten tuberculosis (TB) therapy. It has previously been reported that the azole class of antifungals has anti-TB activity in vitro. This study evaluated ketoconazole (KTC) for activity against M. tuberculosis. The MIC of KTC for different M. tuberculosis strains ranged from 8 to 16 μg ml−1 under both acidic and neutral conditions, with the minimum bactericidal concentration being about twofold higher than the MIC. KTC had enhanced activity against old, non-growing bacilli in vitro when combined with pyrazinamide (PZA) and rifampicin (RIF). A single oral dose of KTC at 75 mg kg−1 led to an inhibitory serum concentration 2 h after administration. The in vivo activity of KTC was evaluated in established pulmonary TB in the murine model, compared alone and in combination with isoniazid (INH), PZA and RIF. KTC alone exhibited little effect after short-term treatment, with a borderline bacteriostatic effect on spleen colony counts but not on lung counts. KTC, when added in combination with INH, PZA and RIF, significantly improved the treatment outcome in the lungs (compared with treatment with INH, PZA and RIF). The lowest numbers of bacilli in lungs were found in mice treated with KTC, PZA and RIF. Further investigation is necessary to determine the role of KTC in the treatment of TB.
Chryseobacterium meningosepticum as a cause of cellulitis and sepsis in an immunocompetent patient
Authors: Tuon Felipe Francisco , Campos Luciana , Duboc de Almeida Gisele , Gryschek Ronaldo César
Published: July 2007

Chryseobacterium meningosepticum is a Gram-negative rod with a worldwide distribution. A case of C. meningosepticum cellulitis with severe sepsis and hepatitis in a 36-year-old male patient is described.
Dissemination of imipenem-resistant Acinetobacter baumannii strains carrying the ISAba1–bla
OXA-23 genes in a Chinese hospital
Authors: Zhou Hua , Pi Bo-Rui , Yang Qing , Yu Yun-Song , Chen Ya-Gang , Li Lan-Juan , Zheng Shu-Sen
Published: July 2007

An outbreak of 95 clinical infections with imipenem-resistant Acinetobacter baumannii in a Chinese hospital was investigated and the carbapenemase-encoding genes and their relationship with ISAba1 of these and a further 16 isolates recovered from the intensive care unit (ICU) environment were analysed. Almost all isolates were resistant to a wide range of antimicrobials; the lowest resistance rates were found for polymyxin E (17.1 %), cefoperazone/sulbactam (30.6 %) and ampicillin/sulbactam (67.6 %). Six pattern types defined by DNA macrorestriction patterns were distinguished among the clinical isolates with dissemination of pattern A (50 isolates) to patients in seven hospital units and pattern B (35 isolates) to eight units; the environmental isolates from ICUs were also of pattern A. All isolates were positive for the bla
OXA-66 and bla
OXA-23 genes. The OXA-23-encoding gene was located 34 bp downstream of ISAba1. No plasmids were detected and conjugal transfer of resistance was not demonstrated. The bla
OXA-23 probe hybridized with 200 and 220 kb ApaI chromosomal fragments for type patterns A and B, respectively.
Interaction of Chlamydia trachomatis serovar E with male genital tract epithelium results in secretion of proinflammatory cytokines
Authors: Al-Mously Najwa , Eley Adrian
Published: July 2007

Although much has been reported on the in vitro interaction of Chlamydia trachomatis with cells derived from the female genital tract, little is known of its interaction with male genital tract epithelium. The aim of this work was to investigate the effect of C. trachomatis serovar E on immortalized normal human urethral epithelial cells and on immortalized normal adult human prostate epithelial cells with regard to chlamydial growth and secretion of cytokines. After infection, these epithelial cells were assessed for their support of chlamydial growth in comparison with HeLa cells, and cytokine levels in cell culture supernatants were determined by ELISA. Although the male-derived epithelial cells supported growth of chlamydiae, the best growth was seen in HeLa cells. In contrast to prostate epithelial cells, the urethral epithelial cells released much larger quantities of interleukin 1α (IL-1α) following infection, whereas both IL-6 and IL-8 were produced in larger quantities by infected prostate cells. At 7 days post-infection, HeLa cells consistently produced large quantities of all three cytokines. In conclusion, the male-derived cell lines were shown to support the invasion of C. trachomatis and initiate a proinflammatory response to infection. From in vitro studies the suggestion that high levels of IL-6 could be a possible marker for chlamydial prostatitis is confirmed. Although not as marked a change, it is also suggested that higher IL-8 levels could be associated more with infection of the prostate than the urethra. Differential cytokine production by different male-derived epithelial cells could help determine the site of chlamydial infection and help in the study of pathogenesis.
Auranofin blocks interleukin‐6 signalling by inhibiting phosphorylation of JAK1 and STAT3
Authors: Kim Nam‐Hoon , Lee Mun‐Yong , Park Seon‐Joo , Choi Jeong‐Sun , Oh Mi‐Kyung , Kim In‐Sook
Published: July 2007

Auranofin (AF) is a sulphur‐containing gold compound. Because of its anti‐inflammatory and immunosuppressive activities, AF has been widely used for the therapeutic treatment of rheumatoid arthritis. However, little is known about its mechanism of action. To elucidate the molecular mechanism underlying the anti‐inflammatory effect of AF, we studied the effects of AF on cellular responses to interleukin‐6 (IL‐6). In HepG2 human hepatoma cells, AF markedly inhibited IL‐6‐induced phosphorylation of janus kinase 1 (JAK1) and signal transducer and activator of transcription 3 (STAT3) and STAT3 translocation into the nucleus. Consistent with this, AF diminished IL‐6‐induced production of the acute‐phase proteins, haptoglobin, fibrinogen, C3 complement and α1‐acid glycoprotein, and gene expression of vascular endothelial growth factor, all of whose transcriptional activities are regulated by STAT3. The inhibitory activity of AF on STAT3 phosphorylation was also demonstrated in primary cells, i.e. fibroblast‐like synoviocytes from rheumatoid arthritis patients, human umbilical vein endothelial cells and rat astrocytes. Auranofin‐mediated inhibition of STAT3 phosphorylation was recovered by pretreatment with antioxidants containing thiol groups. These findings suggest that the anti‐inflammatory action of AF is associated with a blockade of JAK1/STAT3 signalling. Thiol‐group‐reactive proteins may be involved in AF‐induced suppression of JAK1/STAT3 phosphorylation.
Ultrasonographic comparison of gastric motility between diabetic gastroparesis patients with and without metabolic syndrome
Authors: Sogabe Masahiro , Kimura Yoshitaka , Iwaki Hiroshi , Okita Yoshio , Hibino Shingo , Sawda Seizo , Okahisa Toshiya , Okamoto Koichi , Tsujigami Koji , Hayashi Hiroshige , Hukui Yasuo , Nakamura Toshio , Taniki Toshikatsu , Nakasono Masahiko , Muguruma Naoki , Okamura Seisuke , Ito Susumu
Published: July 2007

Background and Aims:  Diabetic patients with poor glycemic control or long standing disease often have impaired gastric motility. Recently, metabolic factors such as blood glucose have been reported as influencing gastric motility independently of autonomic neuropathy. Many diabetic patients have metabolic syndrome, which is strongly associated with coronary and other diseases. We investigated whether metabolic syndrome influences diabetic gastroparesis patients.

Methods:  We observed gastric motility ultrasonographically in diabetic gastroparesis patients including nine with and nine without metabolic syndrome. Both groups complained of upper abdominal symptoms when hospitalized to improve blood sugar control. All patients underwent upper gastrointestinal endoscopy to rule out gastric and duodenal lesions. All had autonomic neuropathy. Gastric motility was evaluated within 3 days after admission by transabdominal ultrasonography after a test meal.

Results:  Gastric emptying was 45.0 ± 13.7% in patients with and 39.1 ± 11.9% in patients without metabolic syndrome, which was not statistically significant. Frequency of gastric contractions was 8.33 ± 2.78 per 3 min in patients with metabolic syndrome and 7.44 ± 2.13 per 3 min in the others, which was not statistically significant. The motility index, which involves antral contractility, was 3.21 ± 2.18 in patients with metabolic syndrome and 2.80 ± 1.87 in the others, which was not statistically significant.

Conclusions:  Metabolic syndrome did not appear to contribute to delayed gastric motility in diabetic gastroparesis.
Post‐cholecystectomy biliary strictures: Not always benign
Authors: Sharma Ajay , Behari Anu , Sikora Sadiq S , Kumar Ashok , Saxena Rajan , Kapoor Vinay K
Published: July 2007

Background:  Post‐cholecystectomy malignant biliary obstruction masquerading as benign biliary stricture (BBS) has not been reported in the literature; it presents a diagnostic and management challenge.

Methods:  Of the 349 post‐cholecystectomy BBS managed at a tertiary care hospital in northern India between 1989 and 2004, 11 patients were found to have biliary malignancy. Records of these 11 patients were analyzed retrospectively for the purpose of this study.

Results:  Mean age of patients with malignant biliary strictures was significantly higher (52 vs 38 years, P = 0.000); they were more likely to have jaundice (100% vs 78%, P = 0.008) and pruritus (82% vs 48%, P = 0.03). Unlike most patients with BBS referred from elsewhere to us, they had had a smooth postoperative course uncomplicated by bile leak, had a longer cholecystectomy‐presentation interval, and were more likely to have high strictures ((Bismuth type III/IV) 91% vs 49%, P = 0.008).

Conclusions:  Post‐cholecystectomy biliary obstruction is not always benign. High bilirubin levels and hilar strictures, especially after an uneventful cholecystectomy, in a middle‐aged patient should raise a suspicion of underlying missed malignancy.
Serious duodenitis concomitant with graft dysfunction following renal transplantation
Authors: Suzuki Kotaro , Saito Kazuo , Yamagishi Takuya , Teranishi Junichi , Noguchi Kazumi , Makiyama Kazuhide , Kubota Yoshinobu
Published: July 2007

Abstract:  A 48‐year‐old woman underwent a renal transplantation from her sister. The graft functioned immediately. She received induction immunosuppressive therapy, including basiliximab, tacrolimus hydrate, mycophenolate mofetil and methylprednisolone. Her urinary output decreased on the first postoperative morning. Plasma exchange for 3 days and conversion from tacrolimus hydrate to cyclosporine partially improved graft function. Graft biopsies on the fifth postoperative day suggested an acute humoral rejection. On the seventh postoperative day, she experienced high fever, disorientation, hypertension and severe upper abdominal pain with a bulk of bloody stool. Graft function deteriorated again. Gastrointestinal fiberscopy showed severe duodenitis with bleeding. Following seven successive daily plasma exchanges with hemodialysis and reconversion to low dose tacrolimus hydrate, the systematic symptoms and graft function gradually improved. Two years after transplantation, graft function was good with a serum creatinine level of 1.0 mg/dL. The patient did not experience any further gastrointestinal symptoms.
Colonic adenocarcinoma in an Indiana pouch successfully treated by endoscopic mucosal resection
Authors: Ryoichi Saito , Hiroyuki Mishima , Nobuyuki Nishikawa , Tomohiro Ueda , Jang Kim Chul
Published: July 2007

Abstract:  We report the case of a 76‐year‐old woman who developed a colonic adenocarcinoma and a stone in an Indiana pouch 15 years after the urinary diversion. The colonic adenocarcinoma was treated endoscopically and we were able to preserve the Indiana pouch. To our knowledge, this is the sixth case of colonic adenocarcinoma in an Indiana pouch.
Three‐dimensional assessment of urinary stone on non‐contrast helical computed tomography as the predictor of stonestreet formation after extracorporeal shock wave lithotripsy for stones smaller than 20 mm
Authors: Yoshida Soichiro , Hayashi Tetsuo , Morozumi Makoto , Osada Hisato , Honda Norinari , Yamada Takumi
Published: July 2007

Abstract:  The incidence of stonestreet formation after extracorporeal shock wave lithotripsy (ESWL) rises with increasing stone burden. However, stonestreet after ESWL is often experienced even in stones smaller than 20 mm. To examine whether the non‐contrast helical computed tomography (CT) data could predict stonestreet formation in these stones, 53 radiopaque stones of 5–20 mm treated with ESWL were evaluated. Maximal dimension was measured on plain radiograph. From an attenuation value histogram graphed from the CT data, total stone volume and mean attenuation value were calculated. Seven stonestreets longer than 25 mm developed. There was no significant difference in maximal dimension and total stone volume between stones that did and stones that did not develop stonestreet. Mean attenuation value was the sole significant predictive factor. Application of mean attenuation value with cut‐off level of 650 HU would anticipate stonestreet formation with a sensitivity of 85.7% and a specificity of 71.7%. The estimated risk of stonestreet formation is high in the treatment of stones with higher mean attenuation value.
Renal cell carcinoma in allograft kidney – a case report with unusual findings at autopsy
Authors: Khan Tahir , Chakrabarty Aruna , Baborie Atik
Published: July 2007

Abstract:  A 30‐year old male who had a non‐related cadaveric renal transplant at the age of 12 years, presented with generalised CNS symptoms and meningeal enhancement on CT scan of the brain, 18 years after the transplantation. Autopsy revealed renal cell carcinoma in the transplanted kidney and metastatic tumour in a variety of organs including the brain. Prior ultrasound scans done at various post‐transplant periods had all been normal. .
Suppression of heart rate variability after supramaximal exertion
Authors: Niewiadomski W. , Gąsiorowska A. , Krauss B. , Mróz A. , Cybulski G.
Published: July 2007

Wingate test is short anaerobic exercise, performed with maximal power, whereas aerobic exercise at 85% maximal heart rate (HRmax) may be performed for long period. Sustained HR elevations and changes in autonomic activity indices have been observed after latter kind of exercise. Several studies reported reduction in mean interval between consecutive R peaks in ECG (RRI) 1 h after Wingate test; however, underlying changes in autonomic activity remain elusive. In eight young males, RRI and heart rate variability (HRV) were measured daily over two 5‐day trials. Subjects exercised on third day of each trial, measurements were taken 1 h after (i) two consecutive 30‐s bouts of Wingate tests or (ii) after a 30‐min exercise at 85% HRmax, with subjects in supine rest and breathing either spontaneously or at controlled rates of 6 and 15 breaths / min. RRI was significantly shorter after Wingate and submaximal exercise, reduction of high‐ and low‐frequency components of HRV attained reliability only after Wingate tests. This pattern remained preserved for three modes of breathing: spontaneous, 6 and 15 breaths /min. After 24 and 48 h, no exercise effects were traceable. We hypothesize that (i) anaerobic exertion is followed by sustained inhibition of vagal activity, (ii) parasympathetic system plays dominant role in mediating suppression of high‐ and low‐HRV frequency components during postexercise recovery, (iii) degree of alteration of autonomic activity caused by anaerobic and strenuous aerobic exercise may be similar and (iv) normalization of vagal activity precedes normalization of sympathetic cardiac nerves activity during final stage of postexercise recovery.
The Greening of Project Finance
Authors: Hadfield‐Hill Sophie
Published: July 2007

Over the past decade, financial institutions have become increasingly conscious of the environmental and social implications of their lending decisions. This is due to widespread environmental and social awareness within mainstream society and the rise of sophisticated nongovernmental organisations. Geography provides an insight into a range of issues related to project finance, particularly with regard to human‐environmental relationships, spatial differentiation and modes of governance. The ‘Equator Principles’ are examined focusing on the contribution that ‘Equator banks’ can make to sustainability. With a critical mass of financial institutions now theoretically in compliance with the latest revisions of the guidelines, ‘Equator Principles II,’ environmental decisions can now be made in relation to a common baseline. When conforming to the Principles, banks in theory can make responsible decisions with regard to the environment and society in regions where development projects are under consideration. However, it is essential that financial institutions and civil society collaborate and trust each other in order for both parties to achieve the desired outcomes of responsible lending and sustainable development. It is imperative that geographers expand their understanding of the project finance industry so as to identify the changes occurring within the lending sector and the consequential environmental and social impact.
Delayed decline of γ‐globin expression in infant age associated with the presence of Gγ−158 (C→T) polymorphism
Authors: GROSSO M. , AMENDOLARA M. , RESCIGNO G. , DANISE P. , TODISCO N. , IZZO P. , AMENDOLA G.
Published: July 2007

Persistent production of fetal hemoglobin (HbF) in adult has ameliorative effects on hemoglobinopathies and great efforts are currently made to achieve an exhaustive understanding of the molecular mechanisms of the switching in globin gene expression. One of the factors reported to be associated with the expression of fetal globin genes is the Xmn I Gγ−158 polymorphism, although it is still unclear if it is involved in this mechanism either by itself or in strong linkage disequilibrium with other loci. Here, we report a novel effect of the Xmn I Gγ−158 site that was found associated with a significant delayed decline of HbF production in infant age. The prolonged decay trend was enhanced when the Gγ−158 C→T substitution was co‐inherited with a β‐thalassemic trait. Our observations reinforce the hypothesis that this region plays an important role in the expression of the γ‐globin genes and give new insights on the intriguing and still poorly understood mechanisms of globin gene expression switching.
Compounded
Heat Transfer Enhancement in Enclosure Natural Convection by Changing the Cold Wall Shape and the
Gas Composition
Authors: Ridouane El
Hassan , Campo Antonio
Published: July 2007

This article addresses compound heat transfer enhancement for gaseous natural convection in closed enclosures; that is, the simultaneous use of two passive techniques to obtain heat transfer enhancement, which is greater than that produced by only one technique itself. The compounded heat transfer enhancement comes from two sources: (1) reshaping the bounded space and (2) the adequacy of the gas. The sizing of enclosures is of great interest in the miniaturization of electronic packaging that is severely constrained by space and∕or weight. The gases consist in a subset of binary gas mixtures formed with helium (He) as the primary gas. The secondary gases are nitrogen (N2), oxygen (O2), carbon dioxide (CO2), methane (CH4), and xenon (Xe). The steady-state flow is governed by a system of 2-D coupled mass, momentum, and energy conservation equations, in conjunction with the ideal gas equation of state. The set of partial differential equations is solved using the finite volume method, for a square and a right-angled isosceles triangular enclosure, accounting for the second-order accurate QUICK and SIMPLE schemes. The grid layouts rendered reliable velocities and temperatures for air and the five gas mixtures at high Ra=106, producing errors within 1% were 18,500 and 47,300 elements for the square and triangle enclosures, respectively. In terms of heat transfer enhancement, helium is better than air for the square and the isosceles triangle. It was found that the maximum heat transfer conditions are obtained filling the isosceles triangular enclosure with a He–Xe gas mixture. This gives a good trade-off between maximizing the heat transfer rate while reducing the enclosure space in half; the maximum enhancement of triangle∕square went up from 19% when filled with air into 46% when filled with He–Xe gas mixture at high Ra=106.
Thermal Analysis of Micro-Column Arrays for Tailored Temperature Control in Space
Authors: Adjim M. , Pillai R. , Bensaoula A. , Starikov D. , Boney C. , Saidane A.
Published: July 2007

Lightweight yet precise, temperature control protocols are critical in a variety of applications. This is especially true in space where weight and volume are at a premium and reliability is paramount. In space, complex processes to manage the heat fluxes generated from within and absorbed from space by the spacecraft are usually implemented. Surfaces having different heat fluxes might need to be controlled separately and maintained at different temperatures. The work presented in this paper evaluates a novel laser surface modification process to form micro-column arrays (MCA) on any material for use as highly adaptive radiators. The MCA-structured surfaces have experimentally been shown to have excellent emissive properties. Finite element methods have been used to simulate the temperature profiles for surfaces with and without MCA compared to pin fin structures as a function of input heat flux density. In the case of Ti, our models show that pin fin arrays are better heat radiating surfaces than equivalent MCA structures with cone-like profiles. Such structures, however, are difficult to modify and usually require complicated and expensive fabrication processes. Overall, MCA structures are shown to allow good control over base surface temperature for varying heat fluxes and different MCA aspect ratios. For Ti, under steady state conditions, an aspect ratio of 12 has been shown to be optimal for surface heat reduction. Preliminary experimental results show that the temperature drop is inline with that theoretically predicted.
Ablation and Aero-thermodynamic Studies on Thermal Protection Systems of Sharp-Nosed Re-entry Vehicles
Authors: Candane S. Rameche , Balaji C. , Venkateshan S. P.
Published: July 2007

A quasi-one-dimensional ablation analysis for a sharp-nosed, reusable, re-entry vehicle that could possibly be used in an unmanned space program, has been carried out by using an in-house code. The code is based on the boundary immobilization technique and the solution has been obtained using the tri-diagonal matrix algorithm (TDMA). The heat fluxes on the spherical nose cap that are used to determine the ablation rate of a thermal coating applied over the surface of the vehicle are obtained by performing a steady state aero-thermodynamic analysis. The aero-thermodynamic analysis for the viscous, compressible flow under consideration is carried out by using FLUENT 6.2. The computational fluid dynamics (CFD) simulations are performed at three locations on the trajectory that the vehicle follows, on re-entry. These simulations yield the temperature and heat flux distributions along the surface of the vehicle and the latter are given as input to the ablation code. The shell material of the vehicle is assumed to be zirconium boride (ZrB2). The code is validated with benchmark cases and the flow and heat transfer characteristics are also discussed. In brief, the present work presents a methodology for coupling an ablation code with CFD simulations from a commercial code, to study the effect of change of the nose region on the ablation process.
Performance and Optimization of Flat Plate Fins of Different Geometry on a Round Tube: A Comparative Investigation
Authors: Kundu B.
Published: July 2007

Owing to a uniform thickness, the fin material of a flat plate fin near to the tip does not participate optimally in transferring heat. On account of this, two new fin geometries of flat plate fins are proposed for improving the heat transfer rate per unit volume. These projected fin geometries, namely flat plate fin circumscribing a circular tube by providing quarter circular cut at the corners of the tip (FQCT) and flat plate fin circumscribing a circular tube having circular arc to cut at the tip (FCAT) are suggested. The thermal performance of the said geometric fins has been determined by a semianalytical method. By using a rigorous semianalytical technique, optimization have been demonstrated in a generalized scheme either by maximizing the rate of heat duty for a given fin volume or by minimizing the fin volume for a given heat transfer duty. The optimization study has also been made with the additional length constraints imposed on one or both sides of the fluid carrying tube. Finally, it can be demonstrated from the optimization study that two proposed fins, namely FQCT and FCAT, can dissipate more rate of heat than the FCT with an identical fin volume and thermophysical parameters. It can also be highlighted that the optimum FQCT and FCAT can transfer heat at a higher rate in comparison with the annular disk fin when a space constraint exists.
Investigation of Detached Eddy Simulations in Capturing the Effects of Coriolis Forces and Centrifugal Buoyancy in Ribbed Ducts
Authors: Viswanathan Aroon K. , Tafti Danesh K.
Published: July 2007

The predictive capability of Detached Eddy Simulations (DES) is investigated in stationary as well as rotating ribbed ducts with relevance to the internal cooling of turbine blades. A number of calculations are presented at Re=20,000 and rotation numbers ranging from 0.18 to 0.67 with buoyancy parameters up to 0.29 in a ribbed duct with ribs normal to the main flow direction. The results show that DES by admitting a LES solution in critical regions transcends some of the limitations of the base RANS model on which it is based. This feature of DES is exemplified by its sensitivity to turbulence driven secondary flows at the rib side-wall junction, to the effect of Coriolis forces, and centrifugal buoyancy effects. It is shown that DES responds consistently to these non-canonical effects when RANS and URANS with the same model cannot, at a cost which is about a tenth of that of LES for the geometry and Reynolds number considered in this study.
An experimental study of louvers for fish diversion
Authors: Shepherd D , Katopodis C , Rajaratnam N
Published: July 2007

This paper presents the results of an experimental study of louvers that are used for diversion of fish from water intakes and canals. This investigation was conducted in two phases. Phase I involved the field testing of a louver with curved slats for the guidance of hatchery-reared juvenile rainbow trout (Onchorhyncus mykiss) for louver angles θ of 7.2° and 17.0°. Phase II was a laboratory study with flat slats placed perpendicular to the approaching flow with θ of 10.0° and 15.0°. The velocity in the bypass in terms of the approach velocity increased to 1.7 and 2.5, respectively, for the curved and flat louvers for a bypass width b equal to 5% of the width of the approach channel B. The discharge in the bypass channel Qb in terms of the discharge in the approach channel Q was 0.15 and 0.20 for b/B = 0.10 for the curved and flat louvers, respectively, and Qb/Q = 0.07 for b/B = 0.05 for both the curved and flat louver slats. Key words: fish diversion, louvers, canals, open channels, water intakes, turbulent flows.
Comparative study of PAH removal efficiency under absence of molecular oxygen: effect of electron acceptor and hydrodynamic conditions
Authors: Uribe-Jongbloed Alberto , Bishop Paul L
Published: July 2007

A series of experiments were made in order to compare the removal efficiency of a mixture of four PAHs (naphthalene, phenanthrene, pyrene, and benzo[a]pyrene), under different electron acceptor (NO3-, SO4-2) and hydrodynamic conditions (stagnation and high shear). In all cases naphthalene showed the highest removal efficiency (from 69% up to 100%) as compared with the other PAHs. The fastest rate was obtained for the denitrifying-high shear condition followed by denitrification-no shear, sulfate-reduction-high shear and the lowest for sulfate reduction-no shear. However, most of the perceived removal of the heavier PAHs could be due to aging. No lag time was observed for the denitrifying experiments, and the denitrification rate was the same regardless of the hydrodynamic condition. A lag time of 64 d was observed under conditions of sulfate reduction and high shear. Sulfate reduction did not commence under no shear conditions. No toxic effect was observed for the four PAH mixture under all the conditions tested. Key words: anaerobic systems, biodegradation, denitrification, hydrodynamic conditions, PAH, sulfate reduction.