bluuebunny/crossref_metadata_2025 huggingface dataset:
Blood parasitaemia in a high latitude flexible breeder, the white-winged crossbill,Loxia leucoptera: contribution of seasonal relapse versus new inoculations
Authors: DEVICHE P. , FOKIDIS H. B. , LERBOUR B. , GREINER E.
Published: October 2009

We measured seasonal changes in the prevalence of haematozoa (Leucocytozoon fringillinarum, Haemoproteus fringillae, andTrypanosoma avium) in free-ranging White-winged Crossbills,Loxia leucoptera, over 1·5 year in Fairbanks, Alaska, USA. This prevalence was low during early winter.L. fringillinarumprevalence increased in late winter/early spring, in the absence of vectors, suggesting relapse of latent infection. By contrast, the prevalence ofT. aviumandH. fringillaedid not increase until mid-spring, coincident with the emergence of putative vectors and suggestive of new inoculations. The winter breeding period was not associated with lower body condition or elevated blood heterophil/lymphocyte ratios than the summer post-breeding period. Thus, birds unlikely perceived their breeding effort as particularly stressful. Adult males in May and June had low plasma testosterone and their blood prevalence ofL. fringillinarum, but not other haemoparasites, was higher than in adult females. This difference may have resulted from sex differences in behaviour and/or plumage colouration – bright red in males, dull green/yellow in females. Species in which reproduction and vector abundance are seasonally dissociated may constitute important models for investigating the respective contribution of reproductive hormones, breeding effort, and vector abundance to patent and latent hemoparasitic infections and to new inoculations.
Decay of similarity with host phylogenetic distance in parasite faunas
Authors: POULIN R.
Published: October 2009

Exponential decay in community similarity as a function of distance is a ubiquitous phenomenon in biogeography. Thus, for parasite communities, pairwise similarity decreases with increasing geographical distance between host populations. This biogeographical rule should also apply along other dimensions characterizing the separation between communities. Since host-switching and phylogenetic affinities among host species affect the evolution of parasite faunas across host phylogenetic space the same way as dispersal and environmental gradients affect the assembly of local communities in geographical space, an exponential decay in similarity of parasite faunas with increasing host phylogenetic distance should be observed. This prediction is tested using data on metazoan parasites of 45 species of Canadian freshwater fishes belonging to 5 families. Across all host species, pairwise similarity in the composition of parasite faunas decayed exponentially, though not strongly, with increasing phylogenetic distance between hosts (measured as the number of substitutions per site along DNA sequences). A meta-analysis of correlations computed for separate fish families indicates only a very weak overall relationship. Data distribution indicates that phylogenetically close host species tend to share many of their parasites, while phylogenetically distant hosts have roughly equal chances of harbouring very similar or very dissimilar parasite faunas. The same pattern was seen when monogenean and trematode parasites were analysed separately, whereas no significant decay was observed for cestodes or nematodes, suggesting different patterns of host-switching and parasite colonization among these taxa. The results show that similarity in species composition decreases, though weakly, with increasing distance in the same manner in phylogenetic space as it does in geographical space.
How the divine properties fit together: reply to Gwiazda
Authors: SWINBURNE RICHARD
Published: October 2009

Jeremy Gwiazda has criticized my claim that God, understood as an omnipotent, omniscient, and perfectly free person is a person ‘of the simplest possible kind’ on the grounds that omnipotence etc. as spelled out by me are omnipotence etc. of restricted kinds, and so less simple forms of these properties than maximal forms would be. However the account which I gave of these properties in The Christian God (although not in The Coherence of Theism) shows that, when they are defined in certain ways, they all follow from one property of ‘pure, limitless, intentional power’. I argue here that a person who has these properties so defined is a person ‘of the simplest possible kind’.
NICHOLAS MAW AND THE MUSIC OF MEMORY
Authors: Whittall Arnold
Published: October 2009

Back in the early 1960s, followers of new music in Britain soon became aware that the future would not be entirely dictated by the innovative radicalism of Princeton or Darmstadt – or even by such iconoclastic Brits as Peter Maxwell Davies and Harrison Birtwistle. And anyone inclined to dismiss Nicholas Maw's Scenes and Arias, on its first version's Proms première in August 1962, as a nostalgic pseudo-Delian wallow, was put right by Anthony Payne's enthusiastic contextualization of Maw in this journal a couple of years later. In Payne's analysis, Scenes and Arias triumphantly avoided rambling romanticism, demonstrating a ‘post-expressionist language’ at ‘a new pitch of intensity’, as well as ‘the composer's exceptional feeling for the movement inherent in atonal harmony’.
MICROTONAL STORM AND STRESS: GEORGY RIMSKY-KORSAKOV AND QUARTER-TONE MUSIC IN 1920S SOVIET RUSSIA
Authors: Ader Lidia
Published: October 2009

‘Passed by the political censor’ – Commissar Lunacharsky

The new Russian generation of composers in 1920s Russia is widely known as the ‘musical avant-garde’. Maximilian Shteinberg, the professor of the Petrograd-Leningrad Conservatoire, who studied under Nikolay Rimsky-Korsakov, called his pupils more simply: ‘musical lefties’. The older generation tried to define this new trend that was evolving as the younger generation' explorations in the fields of musical systems, sounds, subjects, etc. Among the radical musical events in 1920s Soviet Russia, the quarter-tone system of temperament takes first place.
Dialect development in a melting pot: The formation of a new culture and a new dialect in the industrial town of Høyanger
Authors: Solheim Randi
Published: October 2009

The article describes new dialect formation in Høyanger, a small industrial town located in the county of Sogn og Fjordane on the west coast of Norway, where an aluminium industry was established in 1916. Four generations of dialect development are studied from a synchronic and a diachronic point of view, based on older real-time data as well as new fieldwork. Qualitative interviews with informants at different ages shed light on linguistic choices made in complex dialect contact situations, particularly at the decisive second stage of koineization. Local and social embeddings are essential for the interpretations of the results because the linguistic changes seem to be dependent on dynamic relations between language and society. The results are interesting as a contribution to recent debate on the role of identity and social factors in new dialect formation. Related to more general processes of linguistic change, the article also discusses further development of the focused dialect.
THE HEDYOTIS–OLDENLANDIA–KOHAUTIA COMPLEX (RUBIACEAE) IN NEPAL: A STUDY OF FRUIT, SEED AND POLLEN CHARACTERS AND THEIR TAXONOMIC SIGNIFICANCE
Authors: Neupane S. , Dessein S. , Motley T. J.
Published: October 2009

Pollen and seed characters of 12 Nepalese representatives of the Hedyotis–Oldenlandia–Kohautia complex (Spermacoceae s.l.; Rubiaceae) were investigated morphologically using scanning electron and light microscopy. The members of the complex were found to show remarkable variation in fruit, seed and pollen features. Pollen grains were all colporate with the aperture number varying from 3–4 to occasionally 5. The ectoaperture was a colpus, and the endoaperture was an endocingulum, a lalongate endocolpus or an endocolpus combined with an annulus around the mesoporus. Sexine ornamentation was variable, being perforate, reticulate or microreticulate. Three species were found to have a double reticulum. Supratectal elements were generally absent, but sometimes muri were beset with granules. Seeds were numerous per capsule, small and non-crateriform. Three types of seed were distinguished based on shape: (1) lenticular with a narrow wing-like margin, (2) trigonous, and (3) globose/subglobose. Trigonous seeds exhibited marked variation in colour, size and shape. On the basis of the pollen and seed characters, used in combination with the type of fruit dehiscence, five natural groups are identified for Nepalese taxa. The generic status of Hedyotis, Oldenlandia and Kohautia is maintained but some species are transferred from Hedyotis to Oldenlandia. Pollen and seed morphology, together with the type of fruit dehiscence, proved to be helpful in delimiting supra- and infrageneric groups within the Hedyotis–Oldenlandia–Kohautia complex.
SYSTEMATICS OF CLEMENSIELLA (APOCYNACEAE – ASCLEPIADOIDEAE)
Authors: Meve U. , Laurente O. , Alejandro G. J. , Livshultz T.
Published: October 2009

The genus Clemensiella (Apocynaceae – Asclepiadoideae) is reported to include two species. Clemensiella mariae, a Philippine endemic, is redescribed, illustrated, and lectotypified. Its chromosome number (2n = 22) is reported for the first time. The recently described Hoya viracensis is synonymised with Clemensiella mariae. Clemensiella omlori is described as a new species from Borneo and Sumatra. The taxonomic relationship of Clemensiella to other genera of tribe Marsdenieae is discussed.
NOMENCLATURAL TRANSFERS IN EAST MALESIAN MYRSINE (MYRSINACEAE), AND THE DESCRIPTION OF M. WARRAE, A DISTINCTIVE NEW SPECIES FROM ULTRABASIC ENVIRONMENTS IN PAPUA NEW GUINEA
Authors: Takeuchi W. , Pipoly J.
Published: October 2009

Recent studies in the palaeotropics indicate that Rapanea cannot be maintained as a separate genus from Myrsine (Myrsinaceae). Based on the latest evidence from comparative morphology, Papuasian Rapanea are thus transferred to Myrsine. The nomenclatural adjustment provides a foundation for future additions to the enlarged genus, previously represented by only three of the required binomials.After the establishment of a complete set of Myrsine names for eastern Malesia, M. warrae W.N.Takeuchi & Pipoly is added to the redefined conspectus. The new plant is distinguished by large leaves, rostrate fruits, and an apparent restriction to ultrabasic substrates.
N-terminal Pro-B-type Natriuretic Peptide and Ventricular Dysfunction in Children and Adolescents
Authors: Kocharian Armen , Shabanian Reza , Rahimzadeh Mitra , Kiani Abdolrazagh , Hosseini Ahmad , Zanjani Keyhan Sayadpour , Heidari-Bateni Giv , Hosseini-Navid Nasrollah
Published: October 2009

Our aim was further to clarify the diagnostic usefulness of N-terminal pro-B-type natriuretic peptide for detecting ventricular dysfunction in children, and its correlation with myocardial performance index and New York University Pediatric Heart Failure Index score. We also hypothesized that the level of this natriuretic peptide in the serum could predict the severity of diastolic abnormalities in children with cardiac failure. We enrolled 99 patients, aged from 3 months to 16 years, who had been referred for echocardiography to evaluate ventricular function. Echocardiographic evidence of left ventricular systolic and diastolic dysfunction was found in 20 and 42 patients, respectively. We classified these patients as having impaired relaxation, seen in 12 patients, pseudonormal patterns seen in 19 patients, and restrictive-like patterns of filling seen in 11 patients. The mean of the log-transformed values for N-terminal pro-B-type natriuretic peptide increased significantly according to the severity of diastolic dysfunction (p = 0.003, p = 0.022, p < 0.0001). A value of 178 pg/ml had a sensitivity of 88% and specificity of 81% for detecting abnormal diastolic function (p < 0.0001). Furthermore, the log-transformed values correlated with myocardial performance index (p < 0.0001) in a positive manner, and the levels increased significantly according to New York University Pediatric Heart Failure Index score, showing a linear correlation with a robust r value for regression (r = 0.89, p < 0.0001). Our findings suggest that higher levels of the peptide, having a good correlation with New York University Pediatric Heart Failure Index score and myocardial performance index, might be a suitable marker to rule out ventricular diastolic dysfunction in children.
Diagnosis and management of congenital right pulmonary venous atresia
Authors: Argueta-Morales I. Ricardo , Garg Ruchira , DeCampli William M.
Published: October 2009

Congenital unilateral pulmonary venous atresia is a rare anatomical defect. Patients present with pulmonary symptoms, and diagnosis may be ellusive. Pulmonary arterial wedge angiography is the gold standard with which to achieve diagnosis, and surgical intervention is often required for symptomatic patients.
Attentional networks efficiency in preterm children
Authors: PIZZO R. , URBEN S. , VAN DER LINDEN M. , BORRADORI-TOLSA C. , FRESCHI M. , FORCADA-GUEX M. , HÜPPI P. , BARISNIKOV K.
Published: October 2009

Recent studies have reported specific executive and attentional deficits in preterm children. However, the majority of this research has used multidetermined tasks to assess these abilities, and the interpretation of the results lacks an explicit theoretical backdrop to better understand the origin of the difficulties observed. In the present study, we used the Child Attention Network Task (Child ANT; Rueda et al. 2004) to assess the efficiency of the alerting, orienting and executive control networks. We compared the performance of 25 preterm children (gestational age ≤ 32 weeks) to 25 full-term children, all between 5½ and 6½ years of age. Results showed that, as compared to full-term children, preterm children were slower on all conditions of the Child ANT and had a specific deficit in executive control abilities. We also observed a significantly higher correlation between the orienting and executive control networks in the preterm group, suggesting less differentiation of these two networks in this population. (JINS, 2010, 16, 130–137.)
Economic growth related to mutually interdependent institutions and technology
Authors: LIPSEY RICHARD G.
Published: October 2009

This paper argues that technological advance is a necessary condition for sustained economic growth. Technologies and institutions co-evolve in a system of mutual causation. Although some institutions inhibit growth while others encourage it, no single institution is either necessary or sufficient to produce sustained growth. However, some non-unique bundle of encouraging institutions is necessary. Sustained growth began with the Industrial Revolutions that did not just ‘fall out of the blue’ but were instead the culmination of three trajectories of technological advance in steam power, electric power, and the mechanization of textile manufacturing. These stretched over several centuries. Growth then became sustained when the West ‘invented how to invent’. A necessary condition for the Industrial Revolutions was Western science whose roots lie as far back as the scholastic philosophers and the medieval universities. Its absence elsewhere is a sufficient reason why no other place developed its own indigenous industrial revolution.
Ontology and the foundations of evolutionary economic theory: on Dopfer and Potts' General Theory of Economic Evolution
Authors: RUNDE JOCHEN
Published: October 2009

This paper offers a critique of the ‘ontology of evolutionary realism’ proposed in Kurt Dopfer and Jason Potts’ recent General Theory of Economic Evolution, concentrating particularly on their treatment of social rules.
Thorstein Veblen (1857–1929): ‘The Limitations of Marginal Utility’ (1909)
Authors: HODGSON GEOFFREY M.
Published: October 2009

One hundred years ago, Thorstein Veblen (1909b) published what is one of his most important journal articles. In ‘The Limitations of Marginal Utility’, he not only developed his critique of neoclassical economics, but also expanded his own methodological outlook.
Aseismic crustal movement in southern Ryukyu Trench, southwest Japan
Authors: Nakamura Mamoru
Published: October 2009

Anomalous crustal deformation following the Mw = 7.1, March 31, 2002, Hualien earthquake was observed over 5 years using the global positioning system (GPS) network in the south Ryukyu Islands. The analysis showed an afterslip event at a depth of 30 km on the subducting Philippine Sea plate. The magnitude of the cumulative moment reached 7.4. The released moment of the afterslip exceeded the mainshock itself. The afterslip promoted Coulomb failure stress on the fault of the repeating slow slip events (SSEs) in the vicinity of the afterslip. The increase in the slip rate of the SSEs predicted through the change in the Coulomb failure stress is 13%. This is close to the observed increase in slip rate (19%) after the earthquake. This suggests that the afterslip had accelerated the slip rate of the SSEs after the earthquake.
Signatures of low latitude–high latitude coupling in the tropical MLT region during sudden stratospheric warming
Authors: Vineeth C. , Pant T. K. , Kumar K. K. , Ramkumar G. , Sridharan R.
Published: October 2009

The present paper analyses the variations of daytime mesopause temperature over an equatorial station during polar Stratospheric Sudden Warming (SSW) events, indicating a possible dynamical coupling between the two regions, through the intensification of planetary wave activity. The amplified wave signatures of quasi‐16 day period have been seen in the Equatorial Mesopause Temperature (EMT) and Polar Stratospheric Temperature (at 10 hPa) during the course of the SSW. The EMT measurements were made from Trivandrum (8.5°N, 76.5°E), an equatorial station in India and the stratospheric temperatures were obtained from NCEP/NCAR reanalysis. This investigation reveals (1) an overall enhancement and amplified wave activity in the EMT prior to the SSW and (2) propagation of a wave disturbance from equatorial stratosphere to North Pole in about a month. These results are new and reveal some newer aspects of the SSW and its equatorial effects.
On the link between Hadley circulation changes and radiative feedback processes
Authors: Yoshimori Masakazu , Broccoli Anthony J.
Published: October 2009

Previous studies have demonstrated that meridional displacements of precipitation in the tropics and changes in the Hadley circulation accompany interhemispherically asymmetric surface temperature changes. In this study, an attempt is made to provide a different perspective by linking this dynamical response to radiative feedback processes. An idealized experiment is conducted in which solar irradiance is reduced in the northern hemisphere extratropics. Radiative feedback analysis indicates that the interhemispheric asymmetry of water vapor and lapse rate feedbacks play a key role in maintaining the simulated cross‐equatorial heat transport and Hadley circulation change. On the other hand, cloud feedback plays a relatively minor role because of a large cancellation between shortwave and longwave components. While the experiment is idealized, the implications of the results apply widely from paleoclimate to future climate changes.
Comparison between CALIPSO and MIPAS observations of polar stratospheric clouds
Authors: Höpfner M. , Pitts M. C. , Poole L. R.
Published: October 2009

Polar stratospheric cloud (PSC) detection, top height, and composition as derived from measurements by the infrared emission limb sounder Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on Envisat and the Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) lidar have been compared. The comparisons are based on coincident observations from the 2006 and 2007 Antarctic and the 2006/2007 and 2007/2008 Arctic winters. During the middle of the Antarctic season, very good agreement in common PSC detection (around 90%) has been found. At the beginning and end of the Antarctic PSC season and in the Arctic, the frequency of common PSC detection is generally less (60–70%) which can be explained by cloud inhomogeneity and viewing geometry differences. MIPAS PSC top heights are about 0–2 km lower than CALIPSO top heights with larger offsets at higher altitudes. The negative bias of MIPAS PSC top heights can be modeled under the assumptions of limited horizontal cloud extent and a field‐of‐view–dependent sensitivity. The comparisons further show a high degree of consistency between PSC composition derived from the fundamentally different classification approaches of the two instruments. Remaining differences can be explained considering the physical limitations of each approach and the definition of composition boundaries within the classification scheme of each instrument.
Frost flower surface area and chemistry as a function of salinity and temperature
Authors: Obbard Rachel W. , Roscoe Howard K. , Wolff Eric W. , Atkinson Helen M.
Published: October 2009

Frost flowers play a role in air‐ice exchange in polar regions, contribute to tropospheric halogen chemistry, and affect ice core interpretation. Frost flowers were observed and collected on the Hudson Bay in March 2008. Their specific surface area (SSA) was measured using CH4 adsorption at 77 K. The Brunauer‐Emmett‐Teller analysis produced SSA values between 63 and 299 cm2 g−1 (mean 162 cm2 g−1, accuracy and reproducibility 5%). This range is very similar to that of Dominé et al. (2005) but our correlation of results with growth time and chemistry reveals the factors responsible for the wide range of SSA values. Longer growth time leads to higher SSA at low temperatures, so frost flowers are more likely to affect total surface area during colder periods. Chemical analysis was performed on frost flower melt and on local seawater and brine. We examined salinity and sulfate and bromide enrichment. The relationship between growth time and salinity varied spatially because of a freshwater plume from a nearby river and of tidal effects at the coast. Enrichment of certain ions in frost flowers, which affects their contribution to atmospheric chemistry, depends heavily on location, growth time, and temperature. No significant enrichment or depletion of bromide was detected. The low surface area index of frost flowers plus their lack of destruction in wind suggest their direct effect on sea salt mobilization and halogen chemistry may be less than previously thought, but their ability to salinate wind‐blown snow may increase their indirect importance.
Environmental versus biomineralization controls on the intratest variation in the trace element composition of the planktonic foraminifera G. inflata and G. scitula
Authors: Hathorne Ed C. , James Rachael H. , Lampitt Richard S.
Published: October 2009

The intratest variation in the chemical composition of Globorotalia scitula and G. inflata recovered from a sediment trap sample collected at 3000 m in the North Atlantic in early spring has been investigated using laser ablation inductively coupled plasma–mass spectrometry and electron microprobe. Mg/Ca, Li/Ca, B/Ca, Mn/Ca, and Ba/Ca vary by up to a factor of 10 through the test walls. Water column properties, including temperature and salinity, are well documented at the trap site, and the observed variations are too large to be explained by vertical migration of the foraminifera. However, changes in calcite precipitation rate, crystal structure, or the chemical composition of the internal calcification reservoir also cannot, by themselves, fully account for the pattern of intratest variability. Nevertheless, the average Mg/Ca for each chamber generally produces a Mg/Ca temperature that matches that measured in the water column. The exception is small, morphologically distinct G. inflata tests that have anomalously high Mg/Ca.
Critical evaluation of enhancement factors for vapor transport through unsaturated porous media
Authors: Shokri N. , Lehmann P. , Or D.
Published: October 2009

Previous experiments have demonstrated “enhanced” water vapor fluxes from partially saturated porous media relative to fluxes predicted based on Fick's law. This led to various mechanistic and phenomenological enhancement factors to reconcile discrepancies between experiments and predictions. In the present study, analyses of abrupt transitions from liquid‐ to diffusion‐controlled mass transport during evaporation from porous media is used to offer new insights regarding key assumptions and adequacy of experimental setups used to develop vapor transport enhancement factors. We reevaluate these concepts considering the role of capillary‐induced liquid flow through the unsaturated zone in supplying the total fluxes. The extent and existence of hydraulic connections through the unsaturated zone has been predicted theoretically and demonstrated experimentally using high‐resolution X‐ray tomography of sand columns during evaporation. Extending these results to the late stages of evaporation from porous media shows simultaneous capillary induced liquid flow and vapor diffusion supplying the total vapor fluxes as validated by laboratory evaporation experiments. Additionally, analysis of evaporation from porous media provides well defined conditions for testing vapor transport based solely on Fick's law. New insights regarding transport mechanisms controlling evaporation rates from porous media emphasize the extended role of capillary flows beyond previously assumed models and may reconcile observations with prediction without invoking unobservable local thermal gradients and similar enhancement factors. We illustrate that considering the coupling between capillary flow and vapor diffusion predicted by Fick's law of diffusion without any enhancement factors is the essential key to estimate the total vapor flux.
Protein quality control—linking the unfolded protein response to disease
Authors: Cyr Douglas M. , Hebert Daniel N.
Published: October 2009

The proper folding of proteins is essential for cellular homeostasis and prevention of an ever‐growing number of diseases. Here, the authors highlight recent breakthroughs in the study of the unfolded protein response and new strategies to combat the diseases caused by its malfunction.
Strain-induced microstructural evolution in epitaxial Fe/MgO layers grown on InxGa1−xAs(001) substrates
Authors: Kim Kyung-ho , Kim Hyung-jun , Kim Gyeung-Ho , Chang Joonyeon , Han Suk-hee
Published: October 2009

Epitaxial Fe/MgO layers have been grown on InxGa1−xAs substrates to examine the epitaxial relationship and the morphological variation with respect to indium content, x and the growth temperature of MgO interlayer. The in-plane epitaxial relationship of Fe[010]//MgO[11¯0]//InxGa1−xAs[11¯0] is found in the structures of all x values for 4 nm thick MgO layers grown at room temperature. Epitaxial MgO interlayers grow in two-dimensional layer regardless of x while the morphology of subsequent Fe changes from two-dimensional layer to three-dimensional islands with the increase of x. Furthermore, the average size of Fe islands becomes smaller at higher x value due to enhanced underlying strain. The elevated growth temperature of MgO has led to partial strain relaxation, resulting in the suppression of three-dimensional Fe island formation.
Dislocation-interaction-based model of strained-layer relaxation
Authors: Schwarz Klaus W. , Tu Yuhai
Published: October 2009

A strained layer relaxes plastically when dislocations propagate within the layer, leaving behind an array of misfit dislocations at the layer interface. We develop an analytical model of this process, based on the idea that relaxation is frustrated when propagating dislocations are trapped or annihilated by encounters with previously created misfit dislocations or other propagating dislocations. The theory characterizes the evolving density of the misfit array and the density of propagating dislocations in terms of a pair of coupled rate equations. The two trapping functions which appear in these equations are evaluated quantitatively by numerically investigating all possible dislocation-dislocation encounters. Fluctuations in the local stress field driving the individual dislocations are explicitly taken into account when evaluating the trapping functions. Analysis of the rate equations shows that there are two regimes in the strain-relaxation dynamics. Initially, the strain decreases rapidly following a universal dependence on time scaled with the initial dislocation density n0. At a (rescaled) crossover time that increases with n0, the strain levels off from the universal relaxation curve and saturates to an asymptotic residual strain level, which decreases with n0. Microscopically, our model reveals that the initial fast strain-relaxation regime is dominated by collisions between propagating dislocations, while the slow saturation regime is dominated by the trapping of propagating dislocations by the misfits. In the end, the self-trapping of the propagating dislocations by the misfit array they themselves have generated leaves the layer in a frustrated state with residual strain higher than the critical strain. The predictions of the theory are found to be in good agreement with experimental measurements and with large-scale numerical simulations of layer relaxation.
Laser induced dynamics of interacting small particles
Authors: Claro F. , Robles P. , Rojas R.
Published: October 2009

We study the translational motion of two interacting polarizable nanospheres in the presence of a laser field. Dependences of the resulting paths on geometry, viscosity of the medium, polarization, and wavelength of the incident field are discussed. It is found that in general clustering trajectories are more probable thus favoring agglomeration, and that viscosity and circular polarization of the applied field increase further the probability of clustering.
Multiferroic properties of Bi1−xDyxFeO3 nanoparticles
Authors: Qian F. Z. , Jiang J. S. , Guo S. Z. , Jiang D. M. , Zhang W. G.
Published: October 2009

Dysprosium (Dy)-doped BiFeO3 (BFO) (BFDO) nanoparticles were prepared by an ethylene glycol based sol-gel method. Partial substitution of Dy (0%–20%) at the Bi site results in a change from the rhombohedral structure (x=0) to the orthorhombic structure (x=0.10,0.20) of BFO nanoparticles. The average grain size varies from 65 to 24 nm when Dy concentration increases from x=0 to x=0.20. Saturated magnetization Ms of BDFO increases with increasing Dy concentration and decreasing grain size. Moreover, dielectric properties were measured up to high frequency ∼95 MHz, and Dy dopant was found to be helpful to improve dielectric ordering and reduce loss. Surprisingly, the large magnetodielectric coefficient was found to be 4.7% in the as-prepared BFO nanoparticles, and −6.3% in Bi0.8Dy0.2FeO3 at H=100 Oe and f=75 MHz.
Template-based multiwalled TiO2/iron oxides nanotubes: Structure and magnetic properties
Authors: Soroka I. L. , Rooth M. , Lu Jun , Boman M. , Svedlindh P. , Carlsson J.-O. , Hårsta A.
Published: October 2009

Double- and triple-walled TiO2/iron oxide nanotubes with well defined interfaces have been produced in nanoporous alumina templates using atomic layer deposition method. The structural properties of each individual layer are found to be dependent on the deposition temperatures. The outer layers of TiO2 are polycrystalline and consist of a phase mixture of anatase and rutile, while the inner TiO2 layers grown at lower temperature are amorphous. The iron oxide layers consist of pure hematite when deposited at 500 °C, while a phase mixture of hematite and magnetite was obtained at 400 °C. The magnetization measurements reveal that the studied nanotubes exhibit weak ferromagnetic behavior and magnetic anisotropy with an easy axis perpendicular to the tube axis.
Ultrafast gain and refractive index dynamics in GaInNAsSb semiconductor optical amplifiers
Authors: Piwonski T. , Pulka J. , Madden G. , Huyet G. , Houlihan J. , Pozo J. , Vogiatzis N. , Ivanov P. , Rorison J. M. , Barrios P. J. , Gupta J. A.
Published: October 2009

The gain and refractive index dynamics of dilute nitride antimonide semiconductor optical amplifiers are studied using heterodyne pump probe spectroscopy, both in forward and reverse bias regimes. In the forward biased absorption regime, both gain and refractive index relax on the same timescale indicating that both quantities are linked to the same relaxation process, interband recombination. Above transparency, in the forward biased gain regime, the gain and phase exhibit differing timescales resulting in a dynamical alpha factor that varies strongly with time. Reversed bias measurements suggest a recombination dominated absorption recovery where the recovery timescale increases with increasing reversed bias, possibly due to charge separation effects.
Coupled mode analysis of nonlinear defects in photonic crystals
Authors: Li Shaohui , Cai Xuhong
Published: October 2009

We present a general analysis of the coupling of nonlinear photonic crystal cavities using coupled-mode theory. The nonlinear transmission properties of two coupled nonlinear cavities have been investigated. We validate the analysis by comparing the theoretical result with rigorous numerical simulations based on finite-difference time-domain techniques. A device consisting of two nonidentical photonic crystal cavities is proposed, by which we demonstrate that this theory can be employed for designing high-contrast all-optical switches or diodes.
X-ray diffraction study of aluminum carbide powder to 50 GPa
Authors: Ji Cheng , Ma Yanzhang , Chyu Ming-Chien , Knudson Russell , Zhu Hongyang
Published: October 2009

The crystal structure and equation of state (EOS) of aluminum carbide (Al4C3) have been determined directly up to 50.1 GPa at room temperature by the synchrotron x-ray diffraction techniques. The results indicate that Al4C3 remained in rhombohedral structure under all tested pressure-temperature conditions and exhibited anisotropic compressibility, with the c-axis more compressible than the a-axis. Fitting the experimental data to third order Birch–Murnaghan EOS yields a bulk modulus of KOT=233±6 GPa with its pressure derivative KOT′=3.4±0.4, while the second-order EOS yields KOT=223±2 GPa.
Lumped circuit elements, statistical analysis, and radio frequency properties of electrical contact
Authors: Tang W. , Lau Y. Y. , Gilgenbach R. M.
Published: October 2009

The lumped circuit elements representing electrical contact of a single and multiple contact points are constructed. The local electrical contact is assumed to be in the form of a cylindrical constriction (connecting bridge) of radius a and axial length 2h, made of the same material as the main conducting current channel of radius b. The resistance, capacitance, and the inductance of the electrical contact are given in terms of a, b, and h, from which the rf properties of electrical contact are obtained. For the case of conducting surfaces with a single connecting bridge with dimension in micron size, the resulting resonant frequency is found to be in the terahertz regime. A statistical analysis on a distribution of these dimensions follows. It is found that for multiple contact points, the quality factor (Q) and the resonance frequency (ω0) are roughly independent of N, whereas the characteristic impedance (Zc) is proportional to 1/N, where N represents the number of contact points. The implications of these findings are discussed.
Feasibility of terahertz lasing in optically pumped epitaxial multiple graphene layer structures
Authors: Ryzhii V. , Ryzhii M. , Satou A. , Otsuji T. , Dubinov A. A. , Aleshkin V. Ya.
Published: October 2009

A multiple graphene layer (MGL) structure with a stack of GLs and a highly conducting bottom GL on SiC substrate pumped by optical radiation is considered as an active region of terahertz and far infrared lasers with external metal mirrors. The dynamic conductivity of the MGL structure is calculated as a function of the signal frequency, the number of GLs, and the optical pumping intensity. The utilization of optically pumped MGL structures might provide the achievement of lasing with the frequencies of about 1 THz at room temperature due to a high efficiency of pumping.
Correct virial formulation in the isotropic periodic sum method
Authors: Hristov Iordan H. , Paul Reginald , Paddison Stephen J.
Published: October 2009

The original formulation of the virial in the isotropic periodic sum (IPS) method assumes that the sphere defining the local region has a constant radius (the cutoff) independent of the system size. This assumption neglects a virial term originating from the separation between the local sphere and its periodic images. When comparing the IPS virial with that calculated from the cutoff plus long range correction method, the difference observed can be erroneously attributed to the representation of the infinite region. We show that when the two virials are calculated consistently the observed difference is significantly reduced. Additionally, the correct virial that includes the previously missing term is much simpler to calculate. We prove that in the IPS method the virial can be obtained as n/3 times the potential energy for the case of 1/rn type potentials.
Theory of coherent resonance energy transfer for coherent initial condition
Authors: Jang Seogjoo
Published: October 2009

A theory of coherent resonance energy transfer [Jang et al., J. Chem. Phys. 129, 101104 (2008)] is extended for coherent initial condition. For the situation where the initial excitation is an arbitrary linear combination of donor and acceptor excitations, a second order time local quantum master equation combined with polaron transformation is derived. Inhomogeneous terms in the resulting equation have contributions not only from initial donor and acceptor populations but also from their coherence terms. Numerical tests are performed for general super Ohmic spectral density where the bath degrees of freedom coupled to donor and acceptor can be correlated with each other. Calculation results demonstrate sensitivity of early nonstationary population dynamics on the relative sign of initial donor and acceptor excitation states. It is shown that contribution of inhomogeneous terms is more significant for coherent initial condition than for localized one. The overall model calculations provide details of the interplay between quantum coherence and nonequilibrium/non-Markovian effects in the time dependent donor population dynamics.
Large excess volume in grain boundaries of stressed, nanocrystalline metallic thin films: Its effect on grain-growth kinetics
Authors: Kuru Y. , Wohlschlögel M. , Welzel U. , Mittemeijer E. J.
Published: October 2009

The excess volumes per unit grain-boundary area of nanocrystalline Pd and Ni thin films were measured by an efficacious method based on real time in situ x-ray diffraction measurements. The obtained large values for the grain-boundary excess volume reveal the background of surprising, yet unexplained observations of grain growth in nanocrystalline materials.
Coating flow of viscous Newtonian liquids on a rotating vertical disk
Authors: Parmar Nilesh H. , Tirumkudulu Mahesh S. , Hinch E. J.
Published: October 2009

We study a Newtonian viscous liquid coating a vertical rotating disk in the creeping flow regime. Experiments were performed at varying disk rotation speeds and liquid volumes, and the thickness profile at steady state was measured. While the maximum liquid supported by the rotating disk varied with rotation rate and liquid viscosity, the numerical value of a dimensionless number signifying the ratio of gravity to viscous forces was the same in all the cases, γ=0.30. A lubrication analysis for the time evolution of the film thickness that accounted for gravity, surface tension, and viscous forces was solved numerically to steady state. The predicted thickness profiles are in quantitative agreement with those obtained experimentally. The lubrication equation at steady state was solved analytically in the absence of surface tension to obtain constant height contours that were circular and symmetric about the horizontal axis. However to obtain a complete solution, knowledge of the height variation across the contours is required, and this is controlled by the surface tension. On including this effect, we derived an asymptotic solution to predict thickness profiles that agree well with measurements for large values of viscosity or rotation rates.
Effects of geometric shape on the hydrodynamics of a self-propelled flapping foil
Authors: Zhang Xing , Ni Saizhen , Wang Shizhao , He Guowei
Published: October 2009

The hydrodynamics of a free flapping foil is studied numerically. The foil undergoes a forced vertical oscillation and is free to move horizontally. The effect of chord-thickness ratio is investigated by varying this parameter while fixing other ones such as the Reynolds number, the density ratio, and the flapping amplitude. Three different flow regimes have been identified when we increase the chord-thickness ratio, i.e., left-right symmetry, back-and-forth chaotic motion, and unidirectional motion with staggered vortex street. It is observed that the chord-thickness ratio can affect the symmetry-breaking bifurcation, the arrangement of vortices in the wake, and the terminal velocity of the foil. The similarity in the symmetry-breaking bifurcation of the present problem to that of a flapping body under constraint is discussed. A comparison between the dynamic behaviors of an elliptic foil and a rectangular foil at various chord-thickness ratios is also presented.
Highly specialized microbial diversity in hyper-arid polar desert
Authors: Pointing Stephen B. , Chan Yuki , Lacap Donnabella C. , Lau Maggie C. Y. , Jurgens Joel A. , Farrell Roberta L.
Published: October 2009

The McMurdo Dry Valleys in Antarctica are a cold hyperarid polar desert that present extreme challenges to life. Here, we report a culture-independent survey of multidomain microbial biodiversity in McKelvey Valley, a pristine example of the coldest desert on Earth. We demonstrate that life has adapted to form highly-specialized communities in distinct lithic niches occurring concomitantly within this terrain. Endoliths and chasmoliths in sandstone displayed greatest diversity, whereas soil was relatively depauperate and lacked a significant photoautotrophic component, apart from isolated islands of hypolithic cyanobacterial colonization on quartz rocks in soil contact. Communities supported previously unreported polar bacteria and fungi, but archaea were absent from all niches. Lithic community structure did not vary significantly on a landscape scale and stochastic moisture input due to snowmelt resulted in increases in colonization frequency without significantly affecting diversity. The findings show that biodiversity near the cold-arid limit for life is more complex than previously appreciated, but communities lack variability probably due to the high selective pressures of this extreme environment.
Homozygous loss of
BHD
causes early embryonic lethality and kidney tumor development with activation of mTORC1 and mTORC2
Authors: Hasumi Yukiko , Baba Masaya , Ajima Rieko , Hasumi Hisashi , Valera Vladimir A. , Klein Mara E. , Haines Diana C. , Merino Maria J. , Hong Seung-Beom , Yamaguchi Terry P. , Schmidt Laura S. , Linehan W. Marston
Published: October 2009

Germline mutations in the
BHD/FLCN
tumor suppressor gene predispose patients to develop renal tumors in the hamartoma syndrome, Birt-Hogg-Dubé (BHD).
BHD
encodes folliculin, a protein with unknown function that may interact with the energy- and nutrient-sensing AMPK-mTOR signaling pathways. To clarify
BHD
function in the mouse, we generated a
BHD
knockout mouse model.
BHD
homozygous null (
BHD

d/d

) mice displayed early embryonic lethality at E5.5–E6.5, showing defects in the visceral endoderm.
BHD
heterozygous knockout (
BHDd
/+
) mice appeared normal at birth but developed kidney cysts and solid tumors as they aged (median kidney-lesion-free survival = 23 months, median tumor-free survival = 25 months). As observed in human BHD kidney tumors, three different histologic types of kidney tumors developed in
BHD

d
/+

mice including oncocytic hybrid, oncocytoma, and clear cell with concomitant loss of heterozygosity (LOH), supporting a tumor suppressor function for
BHD
in the mouse. The PI3K-AKT pathway was activated in both human BHD renal tumors and kidney tumors in
BHD

d
/+

mice. Interestingly, total AKT protein was elevated in kidney tumors compared to normal kidney tissue, but without increased levels of
AKT
mRNA, suggesting that AKT may be regulated by folliculin through post translational or post-transcriptional modification. Finally,
BHD
inactivation led to both mTORC1 and mTORC2 activation in kidney tumors from
BHD

d
/+

mice and human BHD patients. These data support a role for PI3K-AKT pathway activation in kidney tumor formation caused by loss of
BHD
and suggest that inhibitors of both mTORC1 and mTORC2 may be effective as potential therapeutic agents for BHD-associated kidney cancer.
Antimicrobial Stewardship Programs in Pediatrics
Authors: Hersh Adam L. , Beekmann Susan E. , Polgreen Philip M. , Zaoutis Theoklis E. , Newland Jason G.
Published: October 2009

Objective.

To describe the prevalence, characteristics, and barriers to implementation of antimicrobial stewardship programs (ASPs) in pediatrics.

Design and Participants.

In December 2008, we surveyed the pediatric members of the Emerging Infections Network, a network of infectious diseases consultants located throughout North America. Participants responded regarding whether their hospital had or planned to develop an ASP, its characteristics, barriers to improvement or implementation, and perceptions about antimicrobial resistance.

Results.

Of 246 pediatric infectious disease consultants surveyed, 147 (60%) responded. Forty-five respondents (33%) reported having an ASP, and 25 (18%) were planning a program. The percentage of respondents from freestanding children's hospitals who were planning ASPs was higher than the percentage of respondents from other settings who were planning ASPs (P= .04). Most existing programs were developed before 2000 and had a limited number of full-time equivalent staff, and few programs used a prospective audit-and-feedback structure. Many programs were not monitoring important end points associated with ASPs, including cost and number of antibiotic-days. The major barriers to implementation of an ASP were lack of resources, including funding, time, and personnel, noted by more than 50% of respondents. Regardless of the presence of an ASP, respondents perceived antibiotic resistance as a more significant problem nationally than at their local hospital (P< .001).

Conclusions.

The prevalence of ASPs in pediatrics is limited, and opportunities exist to improve current programs.
The gputools package enables GPU computing in R
Authors: Buckner Joshua , Wilson Justin , Seligman Mark , Athey Brian , Watson Stanley , Meng Fan
Published: October 2009

Motivation: By default, the R statistical environment does not make use of parallelism. Researchers may resort to expensive solutions such as cluster hardware for large analysis tasks. Graphics processing units (GPUs) provide an inexpensive and computationally powerful alternative. Using R and the CUDA toolkit from Nvidia, we have implemented several functions commonly used in microarray gene expression analysis for GPU-equipped computers.

Results: R users can take advantage of the better performance provided by an Nvidia GPU.

Availability: The package is available from CRAN, the R project's repository of packages, at http://cran.r-project.org/web/packages/gputools More information about our gputools R package is available at http://brainarray.mbni.med.umich.edu/brainarray/Rgpgpu

Contact:  bucknerj@umich.edu