bluuebunny/crossref_metadata_2025 huggingface dataset:
The Bicyclic Polyselenium Cation Se102+ in the Structure of Se10[Bi4Cl14]
Authors: Beck Johannes , Eck Steffen J.
Published: July 2010

In the ternary system Se/Bi/Cl a new polycation containing phase besides the already known Se4[Bi4Cl14], Se8[Bi4Cl14], and Se10[Bi5Cl17] was discovered. Red, transparent, plate shaped crystals of Se10[Bi4Cl14] were formed by reaction of Se/SeCl4/BiCl3 in 15:1:8 molar ratio in evacuated glass ampoules applying a temperature gradient from 90 to 80 °C. The crystal structure consists of bicyclic Se102+ cations and of layered chloridobismutate anions with the cations located between the anionic planes. The atoms of the cation form a six membered ring with a Se4 chain bridging over the 1,4 positions of the Se6 ring. The anions are made up of BiCl7 polyhedra connected by common edges to layers all contain an anion of identical formula and two‐dimensional connectivity, but these polymeric chloridobismutates are not isostructural. The structural differences are discussed on basis of the different topologies of the nets made up by the bismuth atoms.
Ileocecal Strictureplasty for Crohn’s Disease: Long‐Term Results and Comparison with Ileocecal Resection
Authors: Tonelli Francesco , Fazi Marilena , Di Martino Carmela
Published: July 2010

Background

The aim of the present study was to evaluate strictureplasty as the first choice for surgical treatment for Crohn’s terminal ileitis.

Methods

Between 1996 and 2000 we performed Finney‐shaped ileocecal strictureplasty (ICS), doubling up the diseased terminal ileum, in 14 patients affected by Crohn’s disease (group A). We compared the postoperative and long‐term outcomes of these patients with those of 14 similar patients who underwent ileocecal resection with ileocolonic anastomosis during the same period (group B).

Results

No postoperative morbidity or mortality was recorded in group A, whereas two patients of group B had a pelvic hematoma and cholestatic hepatopathy, respectively. The mean hospital stay after surgery was 9.9 days (range 7–13 days) in group A and 7.4 days (range 6–10 days) in group B. After a median follow‐up of 120 months (range 103–147 months), five patients of group A had a symptomatic recurrence: A stricture at the site of the ICS was present in four of them, but only one required surgery; symptoms were controlled by medical therapy in the other three. The fifth symptomatic patient was reoperated for multiple jejunoileal recurrence of the disease above the ICS. Group B patients have been followed for a mean of 108 months (range 90–140 months). Four of the patients had a preanastomotic recurrence, with subocclusive symptoms and mild malnutrition treated with medical therapy.

Conclusions

Our results indicate that there are no significant differences between ICS and resection in terms of outcome and clinical relapse of Crohn’s terminal ileitis.
Optic nerve head drusen: a case of false-positive papilledema discovered by ocular ultrasound in the emergency department
Authors: Rifenburg Robert P. , Williams Joseph J.
Published: July 2010

Case report

A 15-year-old female presented to the emergency department (ED) from her optometrists office for further evaluation of reported papilledema. The patient was otherwise asymptomatic. A CT scan was performed in the ED which showed calcification of the optic nerve. A bedside ultrasound was also performed which confirmed the presence of optic nerve calcification in both eyes. The patient was discharged with a diagnosis of optic nerve head drusen and instructed to follow- up with her ophthalmologist for continued monitoring of the drusen.

Discussion

Optic nerve drusen are generally benign lesions associated with pseudopapilledema which may be associated with peripheral field visual defects. Management for this condition in most cases consists of routine ophthalmologic monitoring. There is no definitive treatment for this entity.
Associations among measures of awareness of cognitive deficits in dementia
Authors: Okonkwo Ozioma C. , Spitznagel Mary B. , Alosco Michael L. , Tremont Geoffrey
Published: July 2010

Background

Awareness of deficits is a complex phenomenon. In this study, we examined the relationships among various measures of awareness of cognitive deficits in dementia, and investigated the unique association between clinician ratings and alternative approaches to assessing awareness.

Methods

Participants included 108 patients with very mild (n = 50) or mild (n = 58) dementia. Awareness of cognitive difficulties was assessed by clinician ratings, informant ratings, patients' reports of cognitive difficulties, discrepancies between patients' and informants' reports of cognitive difficulties, and patients' perceptions of performance on neuropsychological tests. Correlational analyses were used to assess associations among these measures of awareness, and ordinal logistic regression was used to examine the unique relationship between clinician ratings of awareness and the other approaches.

Results

All measures of awareness were significantly correlated with one another. Coefficients ranged from 0.26 to −0.64. Patients categorized as unaware by either clinicians or informants reported fewer cognitive difficulties. Of the awareness measures evaluated, clinician ratings had the strongest correlation with measures of global cognition. In the regression analysis, only informant global ratings and patients' reports of cognitive difficulties were significantly associated with clinician ratings. The model's classification accuracy was satisfactory for patients in the “intact awareness” and “severe unawareness” categories, but not for those in the “mild unawareness” category.

Conclusions

Although measures of awareness likely share overlapping variance, they are not interchangeable. Each potentially elucidates unique aspects of the complex phenomenon of awareness, with clinician assessment being the most suited for ambiguous cases. When clinician assessment is not feasible, informant rating (but not patient‐informant discrepancy) would be a valid substitute.
First taxonomic description of multivalvulidan myxosporean parasites from elasmobranchs: Kudoa hemiscylli n.sp. and Kudoa carcharhini n.sp. (Myxosporea: Multivalvulidae)
Authors: GLEESON R. J. , BENNETT M. B. , ADLARD R. D.
Published: July 2010

Myxosporean parasites are significant parasites of fishes not only for their apparent high diversity but also for their potential impact on fish health and/or marketability. Regardless, our knowledge of most myxosporeans, especially those found in elasmobranch hosts, is superficial. A study of multivalvulidan diversity in a range of elasmobranchs from Queensland, Western Australia and the Northern Territory (Australia) was conducted to address this knowledge gap. Specimens were collected from a total of 3 orders, 9 families and 31 species of elasmobranchs. Myxosporean infections referable to the genus Kudoa were discovered in host muscle and characterized morphologically and genetically. Both small subunit (SSU) and large subunit (LSU) rDNA sequences were used in molecular phylogenetic analyses. Kudoa spp. infected 27 of the 31 species of elasmobranchs examined, representing new records of this parasite genus in 26, of the 27, host species. Kudoids were observed in all 3 orders, and 7 out of the 9 families of elasmobranchs investigated. This paper reports the first 2 multivalvulidan species to be formally described from elasmobranchs, Kudoa hemiscylli n.sp. characterized from Hemiscyllium ocellatum (and 8 other host species) and Kudoa carcharhini n. sp. characterized from Carcharhinus cautus (and 2 other host species). Phylogenetic analyses revealed that kudoids from elasmobranchs form a separate lineage to those of teleosts, but are anchored within the overall kudoid clade.
Low levels of transforming growth factor-beta (TGF-beta) and reduced suppression of Th2-mediated inflammation in hyperreactive human onchocerciasis
Authors: KORTEN S. , HOERAUF A. , KAIFI J. T. , BÜTTNER D. W.
Published: July 2010

Th2-biased inflammation with eosinophilia and IgE production is a hallmark of helminth infections. It is pronounced in hyperreactive onchocerciasis patients (‘sowda’ or ‘local form’), who efficiently kill microfilariae resulting in severe dermatitis and lymphadenitis. In contrast, hyporeactive patients (‘generalised form’) tolerate high microfilarial loads. This is thought to be mediated by regulatory CD4+ T cells and macrophages producing suppressive cytokines such as IL-10 and transforming growth factor-beta (TGF-β). We investigated whether hyperreactivity was reflected by lower local TGF-β production, analysing stable latent TGF-β1 expression in onchocercomas, lymph nodes and skin from hyperreactive and hyporeactive patients by immunohistochemistry. TGF-β expression was compared with that of IgE, IgG1, IgG4, and the antigen-presenting, CD4+ T cell-inducing MHC class II molecule HLA-DR. TGF-β was weakly and less frequently expressed by various cell types in onchocercomas, skin and lymph nodes from hyperreactive compared to hyporeactive patients. This applied to reactions around living and dead adult worms as well as dead microfilariae. Antigen-presenting cells strongly expressed HLA-DR in both forms, but their numbers were reduced in hyperreactive nodules. Plasma cells produced more IgE and IgG1, but less of the anti-inflammatory antibody IgG4 in hyperreactive onchocercomas. In conclusion, hyperreactivity is linked with reduced local expression of TGF-β, HLA-DR and IgG4, which might contribute to the insufficient down-regulation of inflammation via TGF-β- and HLA-DR-induced regulatory lymphocytes.
Income, Deprivation and Poverty: A Longitudinal Analysis
Authors: BERTHOUD RICHARD , BRYAN MARK
Published: July 2010

Indices of material deprivation are of increasing interest in Britain and the EU as potential markers of poverty, as an alternative, or complement, to measures of low income. This is the first panel regression analysis of the relationship between households' incomes and deprivation scores over time. We show a close underlying link (people with long-term low incomes report long-term deprivation), but only a weak dynamic link (people whose income increases do not always report a commensurate fall in deprivation). The implications for poverty measurement are important both to academic analysts and to policy-makers.
Development of an individual-based model for polioviruses: implications of the selection of network type and outcome metrics
Authors: RAHMANDAD H. , HU K. , TEBBENS R. J. DUINTJER , THOMPSON K. M.
Published: July 2010

We developed an individual-based (IB) model to explore the stochastic attributes of state transitions, the heterogeneity of the individual interactions, and the impact of different network structure choices on the poliovirus transmission process in the context of understanding the dynamics of outbreaks. We used a previously published differential equation-based model to develop the IB model and inputs. To explore the impact of different types of networks, we implemented a total of 26 variations of six different network structures in the IB model. We found that the choice of network structure plays a critical role in the model estimates of cases and the dynamics of outbreaks. This study provides insights about the potential use of an IB model to support policy analyses related to managing the risks of polioviruses and shows the importance of assumptions about network structure.
Economic analysis of experimental organic agricultural systems on a highly eroded soil of the Georgia Piedmont, USA
Authors: Jacobsen K.L. , Escalante C.L. , Jordan C.F.
Published: July 2010

Information about the costs and labor requirements of experimental organic farming systems designed to restore highly degraded soils in the southeastern US are needed. Enterprise budgets were prepared for the production of okra, hot pepper and a corn/winter squash intercrop under 10 different production systems, nine of which were based on organic conservation tillage. A stochastic dominance analysis was conducted to determine the relative risk efficiency of the 10 systems over the course of the experiment in terms of productivity, profitability and carbon sequestration potential. Organic conservation tillage treatments had lower tractor labor and fuel costs than conventional treatments, due to the extensive tillage required in conventional vegetable farming. The subset of organic treatments receiving compost addition without additional mulches also demonstrated increases in soil carbon, an important driver of system productivity. Organic treatments had little pest and pathogen pressure, with the exception ofFusariumwilt in some treatments receiving straw mulch. Weed suppression by straw mulches reduced labor requirements by an average of 23%. Yields in all treatments were lower than conventional yields from other studies in the region, due to the degraded nature of the soil on the study site. However, net returns on high-labor, organic crops were over US$30,000 ha−1in some treatments. The results of this work indicate that organic, conservation tillage systems can restore soil productivity and command high returns per hectare if labor requirements can be met.
Twentieth century trends in tree ring stable isotopes (δ13C and δ18O) of Larix sibirica under dry conditions in the forest steppe in Siberia
Authors: Knorre Anastasia A. , Siegwolf Rolf T. W. , Saurer Matthias , Sidorova Olga V. , Vaganov Eugene A. , Kirdyanov Alexander V.
Published: July 2010

Tree ring width, density, and ratio of stable isotopes (13C/12C and 18O/16O) in wood and cellulose were determined for larch (Larix sibirica Ledeb.) growing under water deficit conditions in the forest steppe zone in central Siberia (54°24′N, 89°57′E) for the period 1850–2005. Dendroclimatic analysis of the chronologies indicated precipitation to be the most important factor determining indicated parameters. Precipitation of June is significantly correlated with tree ring width and maximum density (r = 0.36 and 0.43, p < 0.05, respectively). Relations of δ13C and δ18O to precipitation are similar, but the most important month is July (r = −0.47, p < 0.05 for δ13C; r = −0.29, p < 0.05 for δ18O). Further, δ18O is positively related to the mean temperatures of July (r = 0.30, p < 0.05). Carbon and oxygen isotope ratios in wood and cellulose showed strong negative trends for the last 100 years. The reason for this decrease could be the observed shift of the beginning of the vegetation period to earlier dates (up to 1 week) in spring and the increased use of precipitation water stored in the soil from October of the previous year, although other explanations cannot be excluded (in particular the physiological effect of increasing atmospheric CO2 also responsible for lower δ13C values). Thus, an earlier start of the vegetation period could lead to tree ring formation during a period with higher water availability, resulting in stronger isotopic fractionation and 13C depletion, also reflected in a higher earlywood to latewood ratio. At the same time, highly 18O depleted water from October precipitation of the previous year is absorbed. The incorporation of this isotopically lighter water during photosynthesis is reflected in the wood and cellulose of tree rings.
Effects of permeability on CO2 trapping mechanisms and buoyancy‐driven CO2 migration in saline formations
Authors: Han Weon Shik , Lee Si‐Yong , Lu Chuan , McPherson Brian J.
Published: July 2010

We present the results from a series of numerical simulations to explore systematic k heterogeneity effects on both CO2 trapping mechanisms and buoyancy‐driven CO2 migration. For this purpose, we generated various permutations of two‐dimensional numerical models of subsurface porous media: homogeneous, random, homogenous with a low‐permeability (k) lens, and isotropically/anisotropically correlated k fields. For heterogeneous cases, we used a sequential Gaussian simulation technique to generate ten realizations in each model permutation. In each simulation, the amounts of mobile, residually, and aqueously trapped CO2 were calculated, and the spatial distributions of the CO2 plumes were quantified using first and second spatial moments. Simulation results from both homogeneous and random k fields suggest that the amount of residually trapped CO2 increases as the mean effective k increases. These results imply that the overall velocity distribution, which governs the sweeping area of the supercritical‐phase CO2 plume, is a critical factor for controlling residual CO2 trapping. However, as overall velocity (or effective k field) increases, we predict that the CO2 plume potentially reaches the caprock more quickly. In addition, results also show that the decrease of variance in ln k increases the amount of residually trapped CO2. In simulations of anisotropically correlated k fields, the vertical CO2 migration distance due to buoyancy shortens as the horizontal correlation length becomes greater. In addition, as the horizontal correlation length becomes greater, residual CO2 trapping increases and mobile CO2 decreases because the CO2 plume spreads farther laterally (i.e., it sweeps a larger area). In summary, results of these analyses suggest that heterogeneous k fields with greater anisotropic correlation ratios potentially maximize residual CO2 trapping and minimize buoyancy‐driven CO2 migration. Our findings also suggest that when heterogeneous k fields have a certain structure such as a low‐k lens or other hydraulic barriers (e.g., faults), the amount of residually trapped CO2 may increase and depend more on the geometry of geological structures than the magnitude of effective k.
Transmission electron microscopy investigations of epitaxial graphene on C-terminated 4H–SiC
Authors: Borysiuk J. , Bożek R. , Grodecki K. , Wysmołek A. , Strupiński W. , Stępniewski R. , Baranowski J. M.
Published: July 2010

Transmission electron microscopy (TEM) investigations of epitaxial graphene, grown on on-axis and 8° off-axis C-terminated 4H–SiC (0001¯) surfaces are presented. The TEM results provide evidence that the first carbon layer is separated by 3.2 Å from the C-terminated SiC surface. It was also found that thick graphene layers grown on on-axis SiC (0001¯) are loosely bound to the SiC substrate. Moreover, the structural observations reveal a certain degree of disorder between the graphene planes, which manifests itself in a rotation of the layers and in an increase in the interplanar spacing between certain carbon layers from 3.35 Å, which is characteristic for graphite, up to 3.7 Å. Graphene grown on 8° off-axis SiC (0001¯) substrates covers the steps of SiC and as a result disorder seems to be not as pronounced as it is on the on-axis SiC (0001¯) substrate.
Thermoelectric property studies on thallium-doped lead telluride prepared by ball milling and hot pressing
Authors: Yu Bo , Zhang Qinyong , Wang Hui , Wang Xiaowei , Wang Hengzhi , Wang Dezhi , Wang Heng , Snyder G. Jeffrey , Chen Gang , Ren Z. F.
Published: July 2010

Thallium doping into lead telluride has been demonstrated to increase the dimensionless thermoelectric figure-of-merit (ZT) by enhancing Seebeck coefficient due to the creation of resonant states close to Fermi level without affecting the thermal conductivity. However, the process is tedious, energy consuming, and small in quantities since it involves melting, slow cooling for crystal growth, long time annealing, post-crushing and hot pressing. Here we show that a similar ZT value about 1.3 at 400 °C is achieved on bulk samples with grain sizes of 3–7 μm by ball milling a mixture of elemental thallium, lead, and tellurium and then hot pressing the ball milled nanopowders.
CO
2
reduction by group 6 transition metal suboxide cluster anions
Authors: Hossain Ekram , Rothgeb David W. , Jarrold Caroline Chick
Published: July 2010

Reactions between small group 6 transition metal suboxide clusters, MxOy− (M=M98o or W186; x=1−4; y≤3x) and both CO2 and CO were studied in gas phase using mass spectrometric analysis of high-pressure, fast flow reaction products. Both Mo2Oy− and W2Oy− show evidence of sequential oxidation by CO2 of the form, M2Oy−+CO2→M2Oy+1−+CO for the more reduced species. Similar evidence is observed for the trimetallic clusters, although Mo3O6− appears uniquely unreactive. Lower mass resolution in the M4Oy− range precludes definitive product mass assignments, but intensity patterns suggest the continued trend of sequential oxidation of the more reduced end of the M4Oy− oxide series. Based on thermodynamic arguments, cluster oxidation by CO2 is possible if D0(OMoxOy−)>5.45 eV. Although simple bond energy analysis suggests that tungsten oxides may be more reactive toward CO2 compared to molybdenum oxides, this is not born out experimentally, suggesting that the activation barrier for the reduction of CO2 by tungsten suboxide clusters is very high compared to analogous molybdenum suboxide clusters. In reactions with CO, suboxides of both metal-based oxides show CO addition, with the product distribution being more diverse for MoxOy− than for WxOy−. No evidence of cluster reduction by CO is observed.
Measuring the conformational properties of 1,2,3,6,7,8-hexahydropyrene and its van der Waals complexes
Authors: Morgan Philip J. , Roscioli Joseph R. , Fleisher Adam J. , Pratt David W.
Published: July 2010

Rotationally resolved fluorescence excitation spectra of the S1←S0 origin band transitions of two conformers of 1,2,3,6,7,8-hexahydropyrene (HHP) have been recorded in the gas phase. The band at 30 648.0 cm−1 has been assigned as the origin band of the chair conformer and the band at 30 658.8 cm−1 has been assigned as the origin band of the boat conformer on the basis of differences in their rotational constants. In addition, rotationally resolved fluorescence excitation spectra of single Ar and H2O van der Waals complexes of chair-HHP have been observed. Analyses of these results indicate that the weakly attached argon atom (water molecule) is located on top of the plane of the bare molecule at ∼3.4 Å (∼4.1 Å) from its center of mass in the S0 electronic state. No complexes of boat-HHP were detected.
Characterization of gate recessed GaN/AlGaN/GaN high electron mobility transistors fabricated using a SiCl4/SF6 dry etch recipe
Authors: Green R. T. , Luxmoore I. J. , Lee K. B. , Houston P. A. , Ranalli F. , Wang T. , Parbrook P. J. , Uren M. J. , Wallis D. J. , Martin T.
Published: July 2010

Incorporating GaN capping layers in conjunction with recessing has been identified as a means to maximize the high frequency performance of AlGaN/GaN high electron mobility transistors (HEMTs). Doping the cap heavily n-type is required in order to ensure minimal loss of carriers from the channel. Using a SiCl4/SF6 dry etch plasma recipe, 250 nm gate length HEMTs with recess lengths varying from 300 nm to 5 μm are fabricated. Heavily doped n+GaN caps enabled contact resistances of 0.3 Ω mm to be achieved. Recessing using a SiCl4/SF6 recipe does not introduce significant numbers of bulk traps. Gate recessing in conjunction with Si3N4 passivation reduces rf dispersion to negligible levels.
High force sensitivity in Q-controlled phase-modulation atomic force microscopy
Authors: Kobayashi Naritaka , Li Yan Jun , Naitoh Yoshitaka , Kageshima Masami , Sugawara Yasuhiro
Published: July 2010

We investigate the dependence of effective Q-factor on force sensitivity in Q-controlled phase-modulation atomic force microscopy. With Q-control, the phase noise density spectrum shows a characteristic dependence on modulation frequency (fm). The phase noise density spectrum is nearly constant in the low-fm region, whereas it decreases inverse-proportionally to fm in the high-fm region. Such a decrease enhances the force sensitivity. We demonstrate that force sensitivity can be markedly increased with Q-control to exceed the limit of force sensitivity without Q-control.
Interfacial thermal conductance in spun-cast polymer films and polymer brushes
Authors: Losego Mark D. , Moh Lionel , Arpin Kevin A. , Cahill David G. , Braun Paul V.
Published: July 2010

Interfaces between inorganic materials and anharmonic polymers have potentially intriguing thermal transport behavior. The low thermal conductivity of amorphous polymers limits significant interfacial effects to polymer film thicknesses of only a few nanometers. We use time-domain thermoreflectance to directly measure interfacial effects in the thermal conductance of spun-cast poly(methyl methacrylate) (PMMA) thin films and PMMA brushes “grafted-from” the substrate. PMMA brushes are expected to have polymer chains partially aligned perpendicular to the substrate, yet only a modest increase (13%) in thermal conductivity is observed over spun-cast layers.
Rotationally resolved electronic spectroscopy of 5-methoxyindole
Authors: Brand Christian , Oeltermann Olivia , Pratt David , Weinkauf Rainer , Meerts W. Leo , van der Zande Wim , Kleinermanns Karl , Schmitt Michael
Published: July 2010

Rotationally resolved electronic spectra of the vibrationless origin and of eight vibronic bands of 5-methoxyindole (5MOI) have been measured and analyzed using an evolutionary strategy approach. The experimental results are compared to the results of ab initio calculations. All vibronic bands can be explained by absorption of a single conformer, which unambiguously has been shown to be the anti-conformer from its rotational constants and excitation energy. For both anti- and syn-conformers, a L1a/L1b gap larger than 4000 cm−1 is calculated, making the vibronic coupling between both states very small, thereby explaining why the spectrum of 5MOI is very different from that of the parent molecule, indole.
Phase separation and exchange biasing in the ferromagnetic IV-VI semiconductor Ge1−xMnxTe
Authors: Lechner R. T. , Springholz G. , Hassan M. , Groiss H. , Kirchschlager R. , Stangl J. , Hrauda N. , Bauer G.
Published: July 2010

Ferromagnetic Ge1−xMnxTe grown by molecular beam epitaxy with Mn content of xMn≈0.5 is shown to exhibit a strong tendency for phase separation. At higher growth temperatures apart from the cubic Ge0.5Mn0.5Te, a hexagonal MnTe and a rhombohedral distorted Ge0.83Mn0.17Te phase is formed. This coexistence of antiferromagnetic MnTe and ferromagnetic Ge0.5Mn0.5Te results in magnetic exchange-bias effects.
Planar Hall effect bridge magnetic field sensors
Authors: Henriksen A. D. , Dalslet B. T. , Skieller D. H. , Lee K. H. , Okkels F. , Hansen M. F.
Published: July 2010

Until now, the planar Hall effect has been studied in samples with cross-shaped Hall geometry. We demonstrate theoretically and experimentally that the planar Hall effect can be observed for an exchange-biased ferromagnetic material in a Wheatstone bridge topology and that the sensor signal can be significantly enhanced by a geometric factor. For the samples in the present study, we demonstrate an enhancement of the sensor output by a factor of about 100 compared to cross-shaped sensors. The presented construction opens a new design and application area of the planar Hall effect, which we term planar Hall effect bridge sensors.
Experimental determination of the quadratic nonlinear magnetic susceptibility of a varactor-loaded split ring resonator metamaterial
Authors: Larouche Stéphane , Rose Alec , Poutrina Ekaterina , Huang Da , Smith David R.
Published: July 2010

This letter presents a quantitative measurement of the second harmonic generated by a slab of varactor loaded split ring resonator metamaterial and the retrieval of the effective quadratic nonlinear magnetic susceptibility χm(2) using an approach based on transfer matrices. The retrieved value of χm(2) is in excellent agreement with that predicted by an analytical effective medium theory model.
Distribution of flow-induced stresses in highly porous media
Authors: Voronov Roman S. , VanGordon Samuel B. , Sikavitsas Vassilios I. , Papavassiliou Dimitrios V.
Published: July 2010

Simulation results for the distribution of flow-induced wall stresses within 36 different porous scaffolds with porosity larger than 80% indicate that the normalized wall stress follows a single gamma distribution. Experimental and computational results for scaffolds prepared via different techniques from different materials and by other laboratories follow the same distribution. The form of this universal distribution is offered, as well as the methodology to obtain it for laminar flow through high porosity materials.
Polarization based control of optical hysteresis in coupled GaAs microdisks
Authors: Ghosh S. N. , Buckley B. B. , Ferri C. G. L. , Li X. , Mendoza F. M. , Verma Y. K. , Samarth N. , Awschalom D. D. , Ghosh S.
Published: July 2010

Optical microresonators crafted from semiconducting materials are powerful systems for both understanding and harnessing the interactions between light and matter. We report an all-optical method of controlling the hysteretic emission of evanescently coupled GaAs microdisk pairs. Under partial excitation, the coupled lasing emission demonstrates optical bistability caused by saturable absorption. We observe that the presence of hysteresis can be modulated by the polarization state of the incident excitation. This optical control is an important functionality which, if extended to a large array, could lead to the creation of optical flip-flop and gated logic devices with multinode capabilities.
Interacting waves on chains of split-ring resonators in the presence of retardation
Authors: Lomanets V. , Zhuromskyy O. , Onishchukov G. , Sydoruk O. , Tatartschuk E. , Shamonina E. , Leuchs G. , Peschel U.
Published: July 2010

Wave propagation is studied experimentally in a one-dimensional periodic chain of magnetically coupled split-ring resonators with a spacing of about one tenth of the resonant wavelength. Retardation leads to a strong interaction between magnetoinductive and free-space waves. Two kinds of guided modes are observed: a slow backward wave which propagates far outside the light cone, and a fast forward wave close to the light cone. The two merge in a region of zero group velocity. The results are relevant for all one- and two-dimensional periodic systems interacting with waves of the surrounding space.
Pressure dependence of plasma structure in microwave gas breakdown at 110 GHz
Authors: Cook Alan , Shapiro Michael , Temkin Richard
Published: July 2010

Recent studies of 110 GHz microwave discharges in air at atmospheric pressure have demonstrated formation of a large array of quarter-wavelength-spaced plasma filaments. Here we present measurements showing that as pressure is decreased from atmosphere to a few torr, the discharge transitions from a well-defined array to a smeared-out array and finally to a diffuse plasma. Despite the distinct nature of breakdown phenomena at high microwave frequencies, the pressure dependence of the breakdown threshold field is seen to follow a Paschen-type curve. Data for air and argon at 110 GHz are compared with previous low-frequency data.
Low-frequency Raman spectra and fragility of imidazolium ionic liquids
Authors: Ribeiro Mauro C. C.
Published: July 2010

Raman spectra within the 5–200 cm−1 range have been recorded as a function of temperature for different ionic liquids based on imidazolium cations. A correlation has been found between fragility and the temperature dependence of the strength of fast relaxational motions. Understanding quasielastic scattering as the relaxational contribution to ionic mean-squared displacement elucidates some effects on ionic liquids’ fragility resulting from modifications in the chemical structure.
Nonlinear optical conductance in a graphene pn junction in the terahertz regime
Authors: Xu X. G. , Sultan S. , Zhang C. , Cao J. C.
Published: July 2010

We show that the optical responses of a graphene pn junction is dominated by nonlinear intraband and interband processes. At the experimentally relevant electric field intensity, nonlinear conductance is an order of magnitude larger than the linear conductance. Furthermore, the total conductance is negative in the terahertz to far infrared regime. The negative conductance provides a unique mechanism for photon generation in graphene and could be used for developing coherent terahertz radiation sources.
Force-controlled spatial manipulation of viable mammalian cells and micro-organisms by means of FluidFM technology
Authors: Dörig Pablo , Stiefel Philipp , Behr Pascal , Sarajlic Edin , Bijl Daniel , Gabi Michael , Vörös János , Vorholt Julia A. , Zambelli Tomaso
Published: July 2010

The FluidFM technology uses microchanneled atomic force microscope cantilevers that are fixed to a drilled atomic force microscope cantilevers probeholder. A continuous fluidic circuit is thereby achieved extending from an external liquid reservoir, through the probeholder and the hollow cantilever to the tip aperture. In this way, both overpressure and an underpressure can be applied to the liquid reservoir and hence to the built-in fluidic circuit. We describe in this letter how standard atomic force microscopy in combination with regulated pressure differences inside the microchanneled cantilevers can be used to displace living organisms with micrometric precision in a nondestructive way. The protocol is applicable to both eukaryotic and prokaryotic cells (e.g., mammalian cells, yeasts, and bacteria) in physiological buffer. By means of this procedure, cells can also be transferred from one glass slide to another one or onto an agar medium.
Developing a Code of Ethics for Psychiatry: The Australasian Experience
Authors: Pargiter Russell , Bloch Sidney
Published: July 2010

The first ever code of ethics of the Royal Australian and New Zealand College of Psychiatrists was promulgated in 1992. In this paper two of the four members of the College's Ethics Committee (which prepared the document) describe the code's provenance and the procedure used to determine its form and content. The code, a milestone in the College's history, reflects its maturity in confronting the many ethical issues with which psychiatrists have to wrestle in contemporary clinical (and research) practice. We hope that our account will assist them to deal effectively with this pivotal aspect of their professional work.
Language, Culture and Psychiatric Services: A Survey of Victorian Clinical Staff
Authors: Minas I. H. , Stuart G. W. , Klimidis S.
Published: July 2010

In planning psychiatric services for non-English speaking immigrant communities it is essential to know what resources are available for the implementation of service plans. A survey of 991 professionals from a variety of disciplines working in Victorian state operated inpatient and community psychiatric services demonstrates that, although there is a substantial number of bilingual clinicians working in the system, there is a poor match between languages spoken by patient groups and clinicians, infrequent contact between bilingual clinicians and patients speaking the same language, and inadequate availability of interpreting services. Clinicians' knowledge of cultural issues relevant to assessment and treatment is inadequate, and there is some enthusiasm among clinical staff for remedying this deficiency. Clinicians express the opinions that services to non-English speaking patients are inferior, and clinical outcome is worse than for the Australian-born. There appears to be general support for changes which would seek to more adequately meet the psychiatric service needs of immigrants.
Police Referrals to a Psychiatric Hospital: Indicators for Referral and Psychiatric Outcome
Authors: Meadows Graham , Calder Greg , van Den Bos Hans
Published: July 2010

Studies of police psychiatric referrals in the USA and the UK generally show these patients to be ill and in need of care. There are, however, no published Australian studies and such findings may not be validly generalised. This prospective study of consecutive police psychiatric referrals in Adelaide reports psychiatric assessment in 92 cases and observations by police in 69 of these, with no evidence of selection bias. The most common reason for referral was threat of self harm (28%). Mental illness was deemed to be present in 49% and the most common clinical description was “situational crisis” (29%). Schizophrenia was diagnosed in 18%. Clinicians viewed 19% of referrals as inappropriate. Increased relative odds for mental illness were associated with police accounts of psychotic symptoms, and decreased odds with threat of self harm and violence. Increased odds for admission were associated with language difficulties and damage to own property, decreased odds with threat to others, threat of suicide, and threat to self injury.

There were 14 cases where possible charges were not being pursued: of these 7 were regarded as ill and 4 were regarded as inappropriate referrals. The rates of major disorders are lower than in other published work. It is proposed that this can be explained by relative ease of referral by police to psychiatry and flexible acceptance criteria.
Abnormal Illness Behaviour: A 25th Anniversary Review
Authors: Pilowsky Issy
Published: July 2010

This paper is based on a lecture given at the Annual Conference of the Royal College of Psychiatrists on 7 July 1994 in Cork, Ireland.
Images of Psychiatry in Recent Australian and New Zealand Fiction
Authors: Dudley Michael
Published: July 2010

Psychiatry is variously portrayed in Australian and New Zealand fiction. This paper describes mental health professionals, settings, conditions, treatments, and social themes essayed in 128 works by 103 authors, published between 1957 and 1992. The predominant images are negative or markedly ambivalent: possible reasons for this are discussed. The perception of psychiatry by the culture in which it is formed and located, as mediated by its creative artists, has important implications for psychiatrist's understanding and explication of their social role, and has an impact on patient's expectations and experiences of psychiatry.
A Review of Dissociation and Dissociative Disorders
Authors: Atchison M. , McFarlane A. C.
Published: July 2010

There has been an explosion of activity concerning dissociation and dissociative disorders overseas, but little interest is apparent in Australian psychiatric publications. This article aims to critically examine the current conceptualisation of dissociation and its proposed relevance to the understanding of psychopathology, in order to create discussion about these issues in Australian psychiatry. Multiple personality disorder and post-traumatic stress disorder are critically examined.
Childhood Depression, Stressors and Parental Depression
Authors: Tisher Miriam , Tonge Bruce J. , de Horne David J. L.
Published: July 2010

The relationship between depression and stressors and the relationship between depression in children and depression in their parents were investigated. Depressed children aged 7–11 years (n=20) were compared with clinical non-depressed children (n=88) and normal children (n=55). Children, mothers and fathers in the three groups were tested. Measures included the Children's Depression Inventory, Recent Life Events Scale, Stressor Scale and Beck Depression Inventory. The findings showed that children and mothers in the depressed group reported more stressors than other children and other mothers while fathers of children in the depressed group did not report more stressors. The findings also showed that mothers of depressed children were more depressed than mothers of normal children while there were no differences between the scores of fathers in the three groups.
Dissecting the role of MPS1 in chromosome biorientation and the spindle checkpoint through the small molecule inhibitor reversine
Authors: Santaguida Stefano , Tighe Anthony , D'Alise Anna Morena , Taylor Stephen S. , Musacchio Andrea
Published: July 2010

The catalytic activity of the MPS1 kinase is crucial for the spindle assembly checkpoint and for chromosome biorientation on the mitotic spindle. We report that the small molecule reversine is a potent mitotic inhibitor of MPS1. Reversine inhibits the spindle assembly checkpoint in a dose-dependent manner. Its addition to mitotic HeLa cells causes the ejection of Mad1 and the ROD–ZWILCH–ZW10 complex, both of which are important for the spindle checkpoint, from unattached kinetochores. By using reversine, we also demonstrate that MPS1 is required for the correction of improper chromosome–microtubule attachments. We provide evidence that MPS1 acts downstream from the AURORA B kinase, another crucial component of the error correction pathway. Our experiments describe a very useful tool to interfere with MPS1 activity in human cells. They also shed light on the relationship between the error correction pathway and the spindle checkpoint and suggest that these processes are coregulated and are likely to share at least a subset of their catalytic machinery.
Sustained Mps1 activity is required in mitosis to recruit O-Mad2 to the Mad1–C-Mad2 core complex
Authors: Hewitt Laura , Tighe Anthony , Santaguida Stefano , White Anne M. , Jones Clifford D. , Musacchio Andrea , Green Stephen , Taylor Stephen S.
Published: July 2010

Mps1 is an essential component of the spindle assembly checkpoint. In this study, we describe a novel Mps1 inhibitor, AZ3146, and use it to probe the role of Mps1’s catalytic activity during mitosis. When Mps1 is inhibited before mitotic entry, subsequent recruitment of Mad1 and Mad2 to kinetochores is abolished. However, if Mps1 is inhibited after mitotic entry, the Mad1–C-Mad2 core complex remains kinetochore bound, but O-Mad2 is not recruited to the core. Although inhibiting Mps1 also interferes with chromosome alignment, we see no obvious effect on aurora B activity. In contrast, kinetochore recruitment of centromere protein E (CENP-E), a kinesin-related motor protein, is severely impaired. Strikingly, inhibition of Mps1 significantly increases its own abundance at kinetochores. Furthermore, we show that Mps1 can dimerize and transphosphorylate in cells. We propose a model whereby Mps1 transphosphorylation results in its release from kinetochores, thus facilitating recruitment of O-Mad2 and CENP-E and thereby simultaneously promoting checkpoint signaling and chromosome congression.
Sar1 assembly regulates membrane constriction and ER export
Authors: Long Kimberly R. , Yamamoto Yasunori , Baker Adam L. , Watkins Simon C. , Coyne Carolyn B. , Conway James F. , Aridor Meir
Published: July 2010

The guanosine triphosphatase Sar1 controls the assembly and fission of COPII vesicles. Sar1 utilizes an amphipathic N-terminal helix as a wedge that inserts into outer membrane leaflets to induce vesicle neck constriction and control fission. We hypothesize that Sar1 organizes on membranes to control constriction as observed with fission proteins like dynamin. Sar1 activation led to membrane-dependent oligomerization that transformed giant unilamellar vesicles into small vesicles connected through highly constricted necks. In contrast, membrane tension provided through membrane attachment led to organization of Sar1 in ordered scaffolds that formed rigid, uniformly nonconstricted lipid tubules to suggest that Sar1 organization regulates membrane constriction. Sar1 organization required conserved residues located on a unique C-terminal loop. Mutations in this loop did not affect Sar1 activation or COPII recruitment and enhanced membrane constriction, yet inhibited Sar1 organization and procollagen transport from the endoplasmic reticulum (ER). Sar1 activity was directed to liquid-disordered lipid phases. Thus, lipid-directed and tether-assisted Sar1 organization controls membrane constriction to regulate ER export.
A chemical tool box defines mitotic and interphase roles for Mps1 kinase
Authors: Lan Weijie , Cleveland Don W.
Published: July 2010

In this issue, three groups (Hewitt et al. 2010. J. Cell Biol. doi:10.1083/jcb.201002133; Maciejowski et al. 2010. J. Cell Biol. doi:10.1083/jcb.201001050; Santaguida et al. 2010. J. Cell Biol. doi:10.1083/jcb.201001036) use chemical inhibitors to analyze the function of the mitotic checkpoint kinase Mps1. These studies demonstrate that Mps1 kinase activity ensures accurate chromosome segregation through its recruitment to kinetochores of mitotic checkpoint proteins, formation of interphase and mitotic inhibitors of Cdc20, and correction of faulty microtubule attachments.
Representations of quadratic Jordan algebras
Authors: McCrimmon Kevin
Published: July 2010

Although representations do not play as much of a role in the theory of Jordan algebras as they do in the associative or Lie theories, they are important in considering Wedderburn splitting theorems and other applications. In this paper we develop a representation theory for quadratic Jordan algebras over an arbitrary ring of scalars, generalizing the usual theory for linear Jordan algebras over a field of characteristic

≠
2

\ne 2

. We define multiplication algebras and representations, characterize these abstractly as quadratic specializations, and relate them to bimodules. We obtain first and second cohomology groups with the usual properties. We define a universal object for quadratic specializations and show it is finite dimensional for a finite-dimensional algebra. The most important examples of quadratic representations, those obtained from commuting linear representations, are discussed and examples are given of new “pathological” representations which arise only in characteristic 2.
The structure of pseudocomplemented distributive lattices. II. Congruence extension and amalgamation
Authors: Grätzer G. , Lakser H.
Published: July 2010

This paper continues the examination of the structure of pseudocomplemented distributive lattices. First, the Congruence Extension Property is proved. This is then applied to examine properties of the equational classes

B

n

,
−
1
≦
n
≦
ω

{\mathcal {B}_n}, - 1 \leqq n \leqq \omega

, which is a complete list of all the equational classes of pseudocomplemented distributive lattices (see Part I). The standard semigroups (i.e., the semigroup generated by the operators H, S, and P) are described. The Amalgamation Property is shown to hold iff

n
≦
2

n \leqq 2

or

n
=
ω

n = \omega

. For

3
≦
n
>
ω
,

B

n

3 \leqq n > \omega ,{\mathcal {B}_n}

does not satisfy the Amalgamation Property; the deviation is measured by a class Amal

(

B

n

)
(
⊆

B

n

)

({\mathcal {B}_n})( \subseteq {\mathcal {B}_n})

. The finite algebras in Amal

(

B

n

)

({\mathcal {B}_n})

are determined.
Entropy for group endomorphisms and homogeneous spaces
Authors: Bowen Rufus
Published: July 2010

Topological entropy

h
d

(
T
)

{h_d}(T)

is defined for a uniformly continuous map on a metric space. General statements are proved about this entropy, and it is calculated for affine maps of Lie groups and certain homogeneous spaces. We compare

h
d

(
T
)

{h_d}(T)

with measure theoretic entropy

h
(
T
)

h(T)

; in particular

h
(
T
)
=

h
d

(
T
)

h(T) = {h_d}(T)

for Haar measure and affine maps

T
T

on compact metrizable groups. A particular case of this yields the well-known formula for

h
(
T
)

h(T)

when

T
T

is a toral automorphism.
Spatially induced groups of automorphisms of certain von Neumann algebras
Authors: Kallman Robert R.
Published: July 2010

This paper gives an affirmative solution, in a large number of cases, to the following problem. Let

R

\mathcal {R}

be a von Neumann algebra on the Hilbert space

H

\mathcal {H}

, let G be a topological group, and let

a
→
φ
(
a
)

a \to \varphi (a)

be a homomorphism of G into the group of

∗

^ \ast

-automorphisms of

R

\mathcal {R}

. Does there exist a strongly continuous unitary representation

a
→
U
(
a
)

a \to U(a)

of G on

H

\mathcal {H}

such that each

U
(
a
)

U(a)

induces

φ
(
a
)

\varphi (a)

?