bluuebunny/crossref_metadata_2025 huggingface dataset:
Hot summers and heart failure: Seasonal variations in morbidity and mortality in Australian heart failure patients (1994–2005)
Authors: Inglis Sally C. , Clark Robyn A. , Shakib Sepehr , Wong Denis T. , Molaee Payman , Wilkinson David , Stewart Simon
Published: May 2008

Background

There are minimal reports of seasonal variations in chronic heart failure (CHF)‐related morbidity and mortality beyond the northern hemisphere.

Aims and methods

We examined potential seasonal variations with respect to morbidity and all‐cause mortality over more than a decade in a cohort of 2961 patients with CHF from a tertiary referral hospital in South Australia subject to mild winters and hot summers.

Results

Seasonal variation across all event‐types was observed. CHF‐related morbidity peaked in winter (July) and was lowest in summer (February): 70 (95% CI: 65 to 76)vs.33 (95% CI: 30 to 37) admissions/1000 at risk (p<0.005). All‐cause admissions (113 (95% CI: 107 to 120)vs.73 (95% CI 68 to 79) admissions/1000 at risk,p<0.001) and concurrent respiratory disease (21%vs.12%,p<0.001) were consistently higher in winter. 2010 patients died, mortality was highest in August relative to February: 23 (95% CI: 20 to 27)vs.12 (95% CI: 10 to 15) deaths per 1000 at risk,p<0.001. Those aged 75 years or older were most at risk of seasonal variations in morbidity and mortality.

Conclusion

Seasonal variations in CHF‐related morbidity and mortality occur in the hot climate of South Australia, suggesting that relative (rather than absolute) changes in temperature drive this global phenomenon.
Dimorphic aggregation behavior of a fusion polypeptide incorporating a stable protein domain (EGFP) with an amyloidogenic sequence (retroCspA)
Authors: Sharma Swati , Guptasarma Purnananda
Published: May 2008

We describe the behavior of a polypeptide consisting of the genetic fusion of a structurally stable single‐domain protein, EGFP (an analog of the green fluorescent protein) with an amyloidogenic sequence, retroCspA (known to readily form amyloid fibrils). Refolding of the fusion protein through single‐step removal of denaturant and salt results in precipitation into amyloid aggregates displaying fibrillar morphology, thioflavin T binding as well as green fluorescence. Refolding through step‐wise reduction of denaturant concentration in the presence of salt yields a soluble aggregate containing a folded, thermally‐stable, non‐fluorescent EGFP domain. Together, these results indicate that retroCspA forces the fusion protein to aggregate; however, the EGFP domain remains folded in a native‐like structural format in both soluble aggregates and precipitates.
Tyrosine phosphorylation of HPK1 by activated Src promotes ischemic brain injury in rat hippocampal CA1 region
Authors: Li Ting , Yu Xiu-Ju , Zhang Guang-Yi
Published: May 2008

Hematopoietic progenitor kinase 1 (HPK1) is a hematopoietic cell‐restricted member of the Ste20 serine/threonine kinase super family. We recently reported that HPK1 is involved in c‐Jun NH2‐terminal kinase (JNK) signaling pathway by sequential activation of MLK3–MKK7–JNK3 after cerebral ischemia. Here, we used 4‐amino‐5‐(4‐chlorophenyl)‐7‐(t‐butyl) pyrazolo [3,4‐d] pyrimidine (PP2) and MK801 to investigate the events upstream of HPK1 in ischemic brain injury. Immunoprecipitation and immunoblot results showed that PP2 and MK801 significantly decreased the activation of Src, HPK1, MLK3, JNK3 and c‐Jun, respectively, during ischemia/reperfusion. Histology and TUNEL staining showed PP2 or MK801 protects against neuron death after brain ischemia. We speculate that this unique signaling pathway through the tyrosine phosphorylation of HPK1 promotes ischemic brain injury by activated Src via N‐methyl‐d‐aspartate receptor and, ultimately, the activation of the MLK3–MKK7–JNK3 pathway after cerebral ischemia.
Dcytb (Cybrd1) functions as both a ferric and a cupric reductase in vitro
Authors: Wyman Steven , Simpson Robert J. , McKie Andrew T. , Sharp Paul A.
Published: May 2008

MDCK cells expressing an inducible duodenal cytochrome b‐green fluorescent protein (Dcytb‐EGFP) fusion construct were used to investigate the function of Dcytb. The Dcytb‐EGFP protein was targeted correctly to the plasma membrane, and cells displayed increased ferric and cupric reductase activities, which were greatly reduced in the presence of doxycycline. The data suggests that Dcytb plays a physiological role in both iron and copper uptake, through divalent metal transporter 1 (DMT1) and copper transporter 1, respectively. In support of this hypothesis, we show that 59Fe uptake was significantly enhanced in Dcytb‐EGFP expressing MDCK cells which endogenously express DMT1.
Is Asian Bioethics Really the Solution?
Authors: AKABAYASHI AKIRA , KODAMA SATOSHI , SLINGSBY BRIAN TAYLOR
Published: May 2008

Today Asia is attracting attention in the area of bioethics. In fact, the potential of bioethics is beginning to be discussed seriously at academic centers across Asia. In Japan, this discussion began a decade ago with the publication “Japanese and Western Bioethics.” The book is one of the principal explorations of biomedical ethics involving Japan to date. Tom Beauchamp, an author of one of the book's chapters, compares Japanese and American standards of informed consent and refutes relativistic positions, concluding that:
In Defense of Routine Recovery of Cadaveric Organs: A Response to Walter Glannon
Authors: SPITAL AARON , TAYLOR JAMES S.
Published: May 2008

Walter Glannon argues that our proposal for routine recovery (also known as conscription) of transplantable cadaveric organs is unacceptable “even if the consequence of [continuing to require consent] would be fewer organs for transplantation and fewer lives saved.” After carefully reviewing his counterarguments, we conclude that, although some of them have merit, none are sufficiently strong to warrant abandoning this plan. Below we respond to each of Glannon's concerns.
Abstracts of Note: The Bioethics Literature
Authors: ISERSON KENNETH V.
Published: May 2008

This section is meant to be a mutual effort. If you find an article you think should be abstracted in this section, do not be bashful—submit it for consideration to feature editor Kenneth V. Iserson care of CQ. If you do not like the editorial comments, this will give you an opportunity to respond in the letters section. Your input is desired and anticipated.
A new global model for P wave speed variations in Earth's mantle
Authors: Li Chang , van der Hilst Robert D. , Engdahl E. Robert , Burdick Scott
Published: May 2008

We document our tomographic method and present a new global model of three‐dimensional (3‐D) variations in mantle P wave velocity. The model is parameterized by means of rectangular cells in latitude, longitude, and radius, the size of which adapts to sampling density by short‐period (1 Hz) data. The largest single data source is ISC/NEIC data reprocessed by Engdahl and coworkers, from which we use routinely picked, short‐period P, Pg, Pn, pP, and pwP data (for earthquakes during the period 1964∼2007). To improve the resolution in the lowermost and uppermost mantle, we use differential times of core phases (PKPAB − PKPDF, PKPAB − PKPBC, Pdiff − PKPDF) and surface‐reflected waves (PP‐P). The low‐frequency differential times (Pdiff, PP) are measured by waveform cross correlation. Approximate 3‐D finite frequency kernels are used to integrate the long‐period data (Pdiff, PP) and short‐period (P, pP, PKP) data. This global data set is augmented with data from regional catalogs and temporary seismic arrays. A crust correction is implemented to mitigate crustal smearing into the upper mantle. We invert the data for 3‐D variations in P wave speed and effects of hypocenter mislocation subject to norm and gradient regularization. Spatial resolution is ∼100 km in the best sampled upper mantle regions. Our model, which is available online and which will be updated periodically, reveals in unprecedented detail the rich variation in style of subduction of lithospheric slabs into the mantle. The images confirm the structural complexity of downwellings in the transition zone discussed in previous papers and show with more clarity the structure of slab fragments stagnant in the transition zone beneath east Asia. They also reveal low wave speed beneath major hot spots, such as Iceland, Afar, and Hawaii, but details of these structures are not well resolved by the data used.
Wave‐driven circulation in a coastal bay during the landfall of a hurricane
Authors: Mulligan Ryan P. , Hay Alex E. , Bowen Anthony J.
Published: May 2008

A coupled wave/flow model was used to simulate the currents in a coastal bay during the landfall of a hurricane with large waves. Extensive wave breaking along the shoreline and over a midbay shoal induced the development of a strong mean circulation in the bay, in combination with currents forced by wind, tide, and storm surge. The general circulation pattern consisted of inflows along the shoreline and over the shoal region that were driven by radiation stress gradients, and outflows due to mass balance of the wave‐driven inflow that were observed in deeper channels. The predicted currents agreed with observations only when wave forcing was included in the circulation model. Wave‐driven flows accounted for over 50% of the high flushing rates during the storm and induced strong horizontal velocity gradients over short (∼200 m) length scales.
Generalization of the linearized discrete model of coupled oscillator arrays to account for coupling delay
Authors: Pogorzelski Ronald J.
Published: May 2008

Arrays of mutually injection locked oscillators have been proposed as a means of providing properly phased excitations for the elements of a phased array antenna. Analysis of such oscillator arrays has typically made use of Van der Pol's oscillator model and Adler's theory of injection locking resulting in a system of nonlinear differential equations for the phases of the oscillators. The solution resulting from a linearization of this formulation is noncausal because it does not account for time delay in the interoscillator coupling. The present analysis extends the linearlized formulation to account for coupling delay and thus yields a causal solution.
Paleomagnetic study of late Miocene through Pleistocene igneous rocks from the southwestern USA: Results from the historic collections of the U.S. Geological Survey Menlo Park laboratory
Authors: Mankinen Edward A.
Published: May 2008

Seventy sites from the southwestern United States provide paleomagnetic results that meet certain minimum criteria and can be considered for the Time‐Averaged Field Initiative (TAFI). The virtual geomagnetic poles for these 70 units are circularly distributed, and their mean is nearly coincident with the rotational axis. When other published data for the southwestern United States are included (N = 146), the virtual geomagnetic poles are again circularly distributed, but their mean is significantly displaced from the rotational axis. Whichever of these data sets is used, the mean poles for normal‐ and reversed‐polarity data differ by ∼170° and are not antipodal at greater than 95% confidence. When the data are separated into specific age groups, the 95% confidence limits about the mean poles for the Brunhes, Matuyama, combined Gauss/Gilbert, and late Miocene intervals all include the rotational axis. Angular dispersion about these four mean poles increases systematically with increasing age and is consistent with paleosecular variation Model “G.”
COSMIC GPS Observations of Northern Hemisphere winter stratospheric gravity waves and comparisons with an atmospheric general circulation model
Authors: Alexander S. P. , Tsuda T. , Kawatani Y.
Published: May 2008

COSMIC satellite temperature data are used to derive the 2006/07 winter mean stratospheric Northern Hemisphere potential energy Ep from gravity waves with vertical wavelengths less than 7 km in grid cells of size 10° × 5°; and to study longitudinal and latitudinal variability in cells of size 20° × 5° × 7 days. Large Ep at 17–23 km is mostly associated with the sub‐tropical jet and shows significant longitudinal variability. Some contribution to total Ep from local orographic sources may occur above the Canadian Rockies, Scandinavia and northern Japan, but not above the Himalayas, due to the background wind conditions. Many of the waves are likely to have low ground‐based phase speeds, as observed by filtering around the 0–10 m s−1 background zonal wind. COSMIC results are compared with a T106L60 AGCM, confirming sub‐tropical jet related generation, upward propagation and low phase speeds of the observed gravity waves.
Vulnerability of the Cordilleran Ice Sheet to iceberg calving during late Quaternary rapid climate change events
Authors: Hendy I. L. , Cosma T.
Published: May 2008

We present the first high‐resolution record of iceberg calving on the continental slope of Vancouver Island, British Columbia (MD02‐2496, 48°58N, 127°02W, 1243 m water depth), through the last glacial from the Cordilleran Ice Sheet (CIS). These previously unknown ice‐rafted debris (IRD) events representing significant retreat of the western margin of the CIS out of marine waters show little correspondence with local climate change. High‐resolution radiocarbon dating indicates that the younger IRD events coincide with global radiocarbon age plateaus that allow direct correlation with distal climate records where the same plateaus have been identified. The coincidence of episodic shedding of IRD from the CIS with North Atlantic climate events (i.e., North Atlantic Deep Water shutdown, and Heinrich events) begs the question: What drove CIS destabilization? Forcing appears to be external to CIS dynamics perhaps resulting from either eustatic sea level rise or episodes of atmospheric warming over the North American continent.
Regional Rates of Cerebral Protein Synthesis Measured with l-[1-11C]Leucine and PET in Conscious, Young Adult Men: Normal Values, Variability, and Reproducibility
Authors: Bishu Shrinivas , Schmidt Kathleen C , Burlin Thomas , Channing Michael , Conant Shielah , Huang Tianjiang , Liu Zhong-hua , Qin Mei , Unterman Aaron , Xia Zengyan , Zametkin Alan , Herscovitch Peter , Smith Carolyn B
Published: May 2008

We report regional rates of cerebral protein synthesis (rCPS) measured with the fully quantitative l-[1-11C]leucine positron emission tomography (PET) method. The method accounts for the fraction (Λ) of unlabeled amino acids in the precursor pool for protein synthesis derived from arterial plasma; the remainder (1-Λ) comes from tissue proteolysis. We determined rCPS and Λ in 18 regions and whole brain in 10 healthy men (21 to 24 years). Subjects underwent two 90-min dynamic PET studies with arterial blood sampling at least 2 weeks apart. Rates of cerebral protein synthesis varied regionally and ranged from 0.97 ± 0.70 to 2.25 ± 0.20 nmol/g per min. Values of rCPS were in good agreement between the two PET studies. Mean differences in rCPS between studies ranged from 9% in cortical regions to 15% in white matter. The Λ value was comparatively more uniform across regions, ranging from 0.63 ± 0.03 to 0.79 ± 0.02. Mean differences in Λ between studies were 2% to 8%. Intersubject variability in rCPS was on average 6% in cortical areas, 9% in subcortical regions, and 12% in white matter; intersubject variability in Λ was 2% to 8%. Our data indicate that in human subjects low variance and highly reproducible measures of rCPS can be made with the l-[1-11C]leucine PET method.
Molecular dynamics study of structure H clathrate hydrates of methane and large guest molecules
Authors: Susilo Robin , Alavi Saman , Ripmeester John A. , Englezos Peter
Published: May 2008

Methane storage in structure H (sH) clathrate hydrates is attractive due to the relatively higher stability of sH as compared to structure I methane hydrate. The additional stability is gained without losing a significant amount of gas storage density as happens in the case of structure II (sII) methane clathrate. Our previous work has showed that the selection of a specific large molecule guest substance (LMGS) as the sH hydrate former is critical in obtaining the optimum conditions for crystallization kinetics, hydrate stability, and methane content. In this work, molecular dynamics simulations are employed to provide further insight regarding the dependence of methane occupancy on the type of the LMGS and pressure. Moreover, the preference of methane molecules to occupy the small (512) or medium (435663) cages and the minimum cage occupancy required to maintain sH clathrate mechanical stability are examined. We found that thermodynamically, methane occupancy depends on pressure but not on the nature of the LMGS. The experimentally observed differences in methane occupancy for different LMGS may be attributed to the differences in crystallization kinetics and/or the nonequilibrium conditions during the formation. It is also predicted that full methane occupancies in both small and medium clathrate cages are preferred at higher pressures but these cages are not fully occupied at lower pressures. It was found that both small and medium cages are equally favored for occupancy by methane guests and at the same methane content, the system suffers a free energy penalty if only one type of cage is occupied. The simulations confirm the instability of the hydrate when the small and medium cages are empty. Hydrate decomposition was observed when less than 40% of the small and medium cages are occupied.
Transition from phase to generalized synchronization in time-delay systems
Authors: Senthilkumar D. V. , Lakshmanan M. , Kurths J.
Published: May 2008

The notion of phase synchronization in time-delay systems, exhibiting highly non-phase-coherent attractors, has not been realized yet even though it has been well studied in chaotic dynamical systems without delay. We report the identification of phase synchronization in coupled nonidentical piecewise linear and in coupled Mackey–Glass time-delay systems with highly non-phase-coherent regimes. We show that there is a transition from nonsynchronized behavior to phase and then to generalized synchronization as a function of coupling strength. We have introduced a transformation to capture the phase of the non-phase-coherent attractors, which works equally well for both the time-delay systems. The instantaneous phases of the above coupled systems calculated from the transformed attractors satisfy both the phase and mean frequency locking conditions. These transitions are also characterized in terms of recurrence-based indices, namely generalized autocorrelation function P(t), correlation of probability of recurrence, joint probability of recurrence, and similarity of probability of recurrence. We have quantified the different synchronization regimes in terms of these indices. The existence of phase synchronization is also characterized by typical transitions in the Lyapunov exponents of the coupled time-delay systems.
Matched soliton pairs of four-wave mixing in molecular magnets
Authors: Wu Ying
Published: May 2008

We investigate the nonlinear dynamics of four-wave mixing in molecular magnets, and show that the matched and coupled electromagnetic soliton pairs can be formed in molecular magnets via a four-wave mixing. It is shown that both bright and dark soliton pairs can propagate through a crystal of molecular magnets and their carrier frequencies are adjustable within the terahertz and sub-terahertz frequency regimes.
Measuring local lattice polarity in AlN and GaN by high resolution Z-contrast imaging: The case of (0001) and (11¯00) GaN quantum dots
Authors: Rouviere Jean-Luc , Bougerol Catherine , Amstatt Benoit , Bellet-Almaric Edith , Daudin Bruno
Published: May 2008

By using a probe Cs corrected transmission electron microscope, the local lattice polarity, i.e., the local stacking of atoms, in AlN and GaN is determined. The N atomic columns are not directly resolved, but determined from the tunnel positions of the structure. The method is first tested on GaN quantum dots grown on polar (0001) AlN surfaces. Then it is applied to GaN quantum dots grown on nonpolar (11¯00) AlN surfaces. In the (112¯0) plane, (11¯00) GaN dots have an asymmetrical shape and grow faster along the +c=[0001] direction than along −c=[0001¯].
Small-scale energy harvesting through thermoelectric, vibration, and radiofrequency power conversion
Authors: Hudak Nicholas S. , Amatucci Glenn G.
Published: May 2008

As sensors for a wide array of applications continue to shrink and become integrated, increasing attention has been focused on creating autonomous devices with long-lasting power supplies. To achieve this, energy will have to be harvested from the sensors’ environment. An energy harvesting device can power the sensor either directly or in conjunction with a battery. Presented herein is a review of three types of energy harvesting with focus on devices at or below the cm3 scale. The harvesting technologies discussed are based on the conversion of temperature gradients, mechanical vibrations, and radiofrequency waves. Operation principles, current state of the art, and materials issues are presented. In addition, requirements and recent developments in power conditioning for such devices are discussed. Future challenges specific to miniaturization are outlined from both the materials and device perspectives.
Force generation due to three-dimensional plasma discharge on a conical forebody using pulsed direct current actuators
Authors: Singh Kunwar Pal , Roy Subrata
Published: May 2008

Understanding the behavior of three-dimensional plasmas around a pulsed dc actuator can be useful for its efficient operation in many applications. The effect of such actuators is studied using a self-consistent multibody system of neutral oxygen species and its plasma. The equations governing the motion of charged species are solved with the drift diffusion approximation. The electrostatic potential is computed from Poisson’s equation. The electric field and ionization level are the highest close to the junction of electrodes and dielectric. The plasma body force thus generated also follows a similar characteristic. Results also show some dc corona instabilities. The temporal average of such force shows mostly acceleration from anode to cathode above the actuator.
Room-temperature high-sensitivity H2S gas sensor based on dendritic ZnO nanostructures with macroscale in appearance
Authors: Zhang N. , Yu Ke , Li Q. , Zhu Z. Q. , Wan Q.
Published: May 2008

Single-crystal dendritic ZnO nanostructures in appearance of macroscale in mass production have been synthesized via the vapor-phase transport method with Cu catalyst at 930°C. The hierarchical ZnO dendrites with a long central trunk and lots of multilevel branches are composed of well-oriented nanorods whose diameters range from 60to800nm. Gas sensors based on as-synthesized ZnO products exhibit high sensitivity and selectivity to H2S gas at room temperature through detecting various gases. The large modulation of the energy barrier of contact between nanorods in ZnO dendrites by H2S gas at room temperature might be the origin of the high sensitivity. The results demonstrate that the ZnO dendrites, with macroscopical appearance and properties of nanomaterials, are potential to develop effective and high performance gas sensors. Moreover, the detailed humidity characteristics of the sensor have also been investigated in the relative humidity range of 5%-97.6%.
Theory of the Sr-induced reconstruction of the Si (001) surface
Authors: Demkov Alexander A. , Zhang Xiaodong
Published: May 2008

By using first-principles calculations, we theoretically investigate the surface reconstruction caused by the adsorption of Sr on the Si (001) surface. For the Sr coverage below 12 monolayer (ML), the system behavior is dominated by the charge transfer between Sr and silicon that results in the “unbuckling” of Si dimers. At a higher coverage, the surface begins to “undimerize.” At the 1 ML coverage, a geometric size constraint induces a series of reconstructions such as 3×, 5×, 7×, etc., characterized by 1×1 reconstructed patches separated by a dimer row. Calculations of the surface energy as function of coverage suggest that for 1 ML of Sr 3×, 5×, and 7× reconstructions of the surface are preferred under the Sr rich conditions, which is in good agreement with the experiment.
Conformal Al2O3 dielectric layer deposited by atomic layer deposition for graphene-based nanoelectronics
Authors: Lee Bongki , Park Seong-Yong , Kim Hyun-Chul , Cho KyeongJae , Vogel Eric M. , Kim Moon J. , Wallace Robert M. , Kim Jiyoung
Published: May 2008

We present a facile route which combines the functionalization of a highly oriented pyrolytic graphite surface with an atomic layer deposition (ALD) process to allow for conformal Al2O3 layers. While the trimethylaluminum (TMA)∕H2O process caused selective deposition only along step edges, the TMA∕O3 process began to provide nucleation sites on the basal planes of the surface. O3 pretreatment, immediately followed by the ALD process with TMA∕O3 chemistry, formed Al2O3 layers without any preferential deposition at the step edges. This is attributed to functionalization of graphene by ozone treatment, imparting a hydrophilic character which is desirable for ALD deposition.
Controlled multipulse loading with a stuffed striker in classical split Hopkinson pressure bar testing
Authors: Xia K. , Chen R. , Huang S. , Luo S. N.
Published: May 2008

Controlled multipulse loading in classical split Hopkinson pressure bar (SHPB) testing is highly desirable for investigating loading history dependent phenomena but rarely explored. Here, we present a novel technique to achieve controlled multipulse loading in SHPB testing with a stuffed striker. This stuffed striker consists of a striker tube, and a striker bar and a gap enclosed inside the tube; upon impact on the input bar, it can produce two separated loading pulses. The gap controls the delay of the second pulse with respect to the first pulse, and the pulse separation (dwell time) can be continuously tuned from zero to hundreds of microseconds. The combination of the stuffed striker and the Lindholm technique [J. Mech. Phys. Solids 12, 317 (1964)] allows for controlled multipulse loading with triple or more pulses. We have validated the working principle of this technique with experiments, and demonstrated its feasibility and flexibility for acquiring relevant dynamic data with double- and triple-pulse loading on polycrystalline Cu. This precisely controlled multipulse loading technique is readily implementable and can be applied to investigating the dynamic response of a wide range of materials.
A minimum-reaction-flux solution to master-equation models of protein folding
Authors: Zhou Huan-Xiang
Published: May 2008

Master equations are widely used for modeling protein folding. Here an approximate solution to such master equations is presented. The approach used may be viewed as a discrete variational transition-state theory. The folding rate constant kf is approximated by the outgoing reaction flux J, when the unfolded set of macrostates assumes an equilibrium distribution. Correspondingly the unfolding rate constant ku is calculated as Jpu∕(1−pu), where pu is the equilibrium fraction of the unfolded state. The dividing surface between the unfolded and folded states is chosen to minimize the reaction flux J. This minimum-reaction-flux surface plays the role of the transition-state ensemble and identifies rate-limiting steps. Test against exact results of master-equation models of Zwanzig [Proc. Natl. Acad. Sci. USA 92, 9801 (1995)] and Muñoz et al. [Proc. Natl. Acad. Sci. USA 95, 5872 (1998)] shows that the minimum-reaction-flux solution works well. Macrostates separated by the minimum-reaction-flux surface show a gap in pfold values. The approach presented here significantly simplifies the solution of master-equation models and, at the same time, directly yields insight into folding mechanisms.
Radiative heat transfer between metallic nanoparticles
Authors: Chapuis Pierre-Olivier , Laroche Marine , Volz Sebastian , Greffet Jean-Jacques
Published: May 2008

In this letter, we study the radiative heat transfer between two nanoparticles in the near and far fields. We find that the heat transfer is dominated by the electric dipole-dipole interaction for identical dielectric particles and by the magnetic dipole-dipole interaction for identical metallic nanoparticles. We introduce polarizability formulas valid for arbitrary values of the skin depth. While the heat transfer mechanism is different for metallic and dielectric nanoparticles, we show that the distance dependence is the same. However, the dependence of the heat flux on the particle radius is different.
Generating genetic relatedness maps to improve the management of two rare orchid species
Authors: Broadhurst Linda M. , Scannell Paul K. , Johnson Glen A.
Published: May 2008

Arachnorchis concolor and A. pilotensis are two rare orchid species with contrasting spatial distributions found in south-eastern Australia. A. concolor is known from ~220 plants, with the largest population found in southern central Victoria and the remaining smaller populations ~100 km north. Some taxonomic uncertainty surrounds the affiliations of these disjunct populations. A. pilotensis is known from ~100 plants in a single location near the Beechworth region of north-eastern Victoria. Small populations such as these can show extreme demographic and/or genetic constraints and careful management is required to ensure their long-term persistence. The present study used amplified fragment length polymorphism (AFLP) markers to describe the levels of relatedness among plants from both species and to determine levels of genetic diversity for each species as well as levels of differentiation among A. concolor populations, to assist with species management. Species-level genetic diversity was lower in A. pilotensis (PLP 44%, Hj 0.182) than A. concolor (PLP 58.2%, Hj 0.202). Genetic diversity also varied among A. concolor populations but this does not appear to relate to population size. High levels of inbreeding were evident in A. concolor (f, 0.828) in contrast to moderate levels observed in A. pilotensis (f, 0.466). Genetic relatedness maps, generated by principal coordinates analyses, indicated significant differentiation among A. concolor populations with some sub-structuring also apparent within A. pilotensis. Management implications for the two species, with respect to sourcing of material for translocation and augmentation of pollination events within populations, are discussed in light of these findings.
Overcoming physiological dormancy in Prostanthera eurybioides (Lamiaceae), a nationally endangered Australian shrub species
Authors: Ainsley P. J. , Jones M. K. , Erickson T. E.
Published: May 2008

Prostanthera eurybioides (Lamiaceae) is an endangered shrub endemic to South Australia. Fruits consist of four mericarps enclosed by a persistent calyx, with each seed characterised by the presence of what we are defining as a mericarp plug. Research focussed on understanding the role of the mericarp plug in the germination process, determining seed dormancy classification and germination cues. Treatments tested included combinations of pulse dry heat (60–120°C) for up to 60 min, continuous application of gibberellic acid (100 mg L–1), smoked water (10% (v/v)) and excision of the mericarp plug. Seed imbibition experiments dispelled the presence of physical dormancy. The mericarp plug was found to be acting as a mechanical barrier preventing germination. Pulse dry heat (80°C) significantly improved germination, as did removal of the mericarp plug. Smoked water inhibited germination. Based on germination response, seeds have been classified as having non-deep physiological dormancy, with maximum germination (86%) observed following a pulse heat treatment (80°C, 10 min) and removal of the mericarp plug. Natural mechanisms for overcoming dormancy are proposed.
Virulence-transmission trade-offs and population divergence in virulence in a naturally occurring butterfly parasite
Authors: de Roode Jacobus C. , Yates Andrew J. , Altizer Sonia
Published: May 2008

Why do parasites harm their hosts? Conventional wisdom holds that because parasites depend on their hosts for survival and transmission, they should evolve to become benign, yet many parasites cause harm. Theory predicts that parasites could evolve virulence (i.e., parasite-induced reductions in host fitness) by balancing the transmission benefits of parasite replication with the costs of host death. This idea has led researchers to predict how human interventions—such as vaccines—may alter virulence evolution, yet empirical support is critically lacking. We studied a protozoan parasite of monarch butterflies and found that higher levels of within-host replication resulted in both higher virulence and greater transmission, thus lending support to the idea that selection for parasite transmission can favor parasite genotypes that cause substantial harm. Parasite fitness was maximized at an intermediate level of parasite replication, beyond which the cost of increased host mortality outweighed the benefit of increased transmission. A separate experiment confirmed genetic relationships between parasite replication and virulence, and showed that parasite genotypes from two monarch populations caused different virulence. These results show that selection on parasite transmission can explain why parasites harm their hosts, and suggest that constraints imposed by host ecology can lead to population divergence in parasite virulence.
Factor VIII accelerates proteolytic cleavage of von Willebrand factor by ADAMTS13
Authors: Cao Wenjing , Krishnaswamy Sriram , Camire Rodney M. , Lenting Peter J. , Zheng X. Long
Published: May 2008

Proteolytic processing of von Willebrand factor (VWF) by ADAMTS13 metalloproteinase is crucial for normal hemostasis.
In vitro
, cleavage of VWF by ADAMTS13 is slow even at high shear stress and is typically studied in the presence of denaturants. We now show that, under shear stress and at physiological pH and ionic strength, coagulation factor VIII (FVIII) accelerates, by a factor of ≈10, the rate of specific cleavage at the Tyr
1605
–Met
1606
bond in VWF. Multimer analysis reveals that FVIII preferentially accelerates the cleavage of high-molecular-weight multimers. This rate enhancement is not observed with VWF predenatured with 1.5 M guanidine. The ability of FVIII to enhance VWF cleavage by ADAMTS13 is rapidly lost after pretreatment of FVIII with thrombin. A FVIII derivative lacking most of the B domain behaves equivalently to full-length FVIII. In contrast, a derivative lacking both the B domain and the acidic region a3 that contributes to the high-affinity interaction of FVIII with VWF exhibits a greatly reduced ability to enhance VWF cleavage. Our data suggest that FVIII plays a role in regulating proteolytic processing of VWF by ADAMTS13 under shear stress, which depends on the high-affinity interaction between FVIII and its carrier protein, VWF.
Hecke operators for weakly holomorphic modular forms and supersingular congruences
Authors: Guerzhoy P.
Published: May 2008

We consider the action of Hecke operators on weakly holomorphic modular forms and a Hecke-equivariant duality between the spaces of holomorphic and weakly holomorphic cusp forms. As an application, we obtain congruences modulo supersingular primes, which connect Hecke eigenvalues and certain singular moduli.
Trigonometric and Rademacher measures of nowhere finite variation
Authors: Anantharaman R.
Published: May 2008

Let

X
X

be an infinite dimensional real Banach space. It was proved by E. Thomas and soon thereafter by L. Janicka and N. J. Kalton that there always exists a measure

μ
\mu

into

X
X

with relatively norm-compact range such that its variation measure assumes the value

∞
\infty

on every non-null set. Such measures have been called “measures of nowhere finite variation” by K. M. Garg and the author, who as well as L. Drewnowski and Z. Lipecki have done related investigations. We give some “concrete” examples of such

μ
\mu

’s in the

l
p

l^p

spaces defined using the (real) trigonometric system

(

t
n

)

(t_n)

and the Rademacher system

(

r
n

)

(r_n)

illustrating similarities and some differences. We also look at the extensibility of the integration map of these

μ
\mu

’s. As an application of the trigonometric example, we have the probably known result: For every

p
≥
1

p\ge 1

, the function

(
Σ
(

|

t
n

(
t
)

|

p

)

/

n
)

(\Sigma (| t_n (t) | ^p ) / n )

is unbounded on every set

A
A

with positive measure.
𝐿^{𝑝} bounds for oscillatory hyper-Hilbert transform along curves
Authors: Chen Jiecheng , Fan Dashan , Wang Meng , Zhu Xiangrong
Published: May 2008

We study the oscillatory hyper-Hilbert transform
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper H Subscript n comma alpha comma beta Baseline f left-parenthesis x right-parenthesis equals integral Subscript 0 Superscript 1 Baseline f left-parenthesis x minus normal upper Gamma left-parenthesis t right-parenthesis right-parenthesis e Superscript i t Super Superscript negative beta Baseline t Superscript negative 1 minus alpha Baseline d t">

H

n
,
α
,
β

f
(
x
)
=

∫
0
1

f
(
x
−
Γ
(
t
)
)

e

i

t

−
β

t

−
1
−
α

d
t

\begin{equation} H_{n,\alpha ,\beta }f(x)=\int ^1_0 f(x-\Gamma (t))e^{it^{-\beta }}t^{-1-\alpha }dt \end{equation}

along the curve
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="normal upper Gamma left-parenthesis t right-parenthesis equals left-parenthesis t Superscript p 1 Baseline comma t Superscript p 2 Baseline comma midline-horizontal-ellipsis comma t Superscript p Super Subscript n Superscript Baseline right-parenthesis">

Γ
(
t
)
=
(

t

p
1

,

t

p
2

,
⋯
,

t

p
n

)

\Gamma (t)=(t^{p_1},t^{p_2},\cdots ,t^{p_n})

, where

p
1

,

p
2

,
⋯
,

p
n

,
α
,
β

p_1,p_2,\cdots ,p_n,\alpha ,\beta

are some real positive numbers. We prove that if

β
>
(
n
+
1
)
α

\beta >(n+1)\alpha

, then

H

n
,
α
,
β

H_{n,\alpha ,\beta }

is bounded on

L
p

L^p

whenever
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="p element-of left-parenthesis StartFraction 2 beta Over 2 beta minus left-parenthesis n plus 1 right-parenthesis alpha EndFraction comma StartFraction 2 beta Over left-parenthesis n plus 1 right-parenthesis alpha EndFraction right-parenthesis">

p
∈
(

2
β

2
β
−
(
n
+
1
)
α

,

2
β

(
n
+
1
)
α

)

p \in (\frac {2\beta }{2\beta -(n+1)\alpha },\frac {2\beta }{(n+1)\alpha })

. Furthermore, we also prove that

H

n
,
α
,
β

H_{n,\alpha ,\beta }

is bounded on

L
2

L^2

when

β
=
(
n
+
1
)
α

\beta =(n+1)\alpha

. Our work improves and extends some known results by Chandarana in 1996 and in a preprint. As an application, we obtain an

L
p

L^p

boundedness result for some strongly parabolic singular integrals with rough kernels.
Products of Borel subgroups
Authors: Ding Longyun , Li Bingqing
Published: May 2008

We investigate the Borelness of the product of two Borel subgroups in Polish groups. While the intersection of these two subgroups is Polishable, the Borelness of their product is confirmed. On the other hand, we construct two

Δ

3

0

\boldsymbol {\Delta }^{0}_{3}

subgroups whose product is not Borel in every uncountable abelian Polish group.
Homogeneous and inhomogeneous manifolds
Authors: Gartside Paul , Gauld David , Greenwood Sina
Published: May 2008

All metaLindelöf, and most countably paracompact, homogeneous manifolds are Hausdorff. Metacompact manifolds are never rigid. Every countable group can be realized as the group of autohomeomorphisms of a Lindelöf manifold. There is a rigid foliation of the plane.
The remainder in asymptotic integration
Authors: Behncke Horst
Published: May 2008

Quantitative estimates for the remainder terms in Levinson’s Theorem are provided. This gives a precise meaning to the idea that small perturbations should result in small remainder terms.
𝐾-stability on toric manifolds
Authors: Zhou Bin , Zhu Xiaohua
Published: May 2008

In this note, we prove that on polarized toric manifolds the relative

K
K

-stability with respect to Donaldson’s toric degenerations is a necessary condition for the existence of Calabi’s extremal metrics, and we also show that the modified

K
K

-energy is proper in the space of

G
0

G_0

-invariant Kähler potentials in the case of toric surfaces which admit the extremal metrics.
Robot motion planning, weights of cohomology classes, and cohomology operations
Authors: Farber Michael , Grant Mark
Published: May 2008

The complexity of algorithms solving the motion planning problem is measured by a homotopy invariant

T
C

(
X
)

\mathrm {TC}(X)

of the configuration space

X
X

of the system. Previously known lower bounds for

T
C

(
X
)

\mathrm {TC}(X)

use the structure of the cohomology algebra of

X
X

. In this paper we show how cohomology operations can be used to sharpen these lower bounds for

T
C

(
X
)

\mathrm {TC}(X)

. As an application of this technique we calculate explicitly the topological complexity of various lens spaces. The results of the paper were inspired by the work of E. Fadell and S. Husseini on weights of cohomology classes appearing in the classical lower bounds for the Lusternik-Schnirelmann category. In the appendix to this paper we give a very short proof of a generalized version of their result.
Canonical forms, higher rank numerical ranges, totally isotropic subspaces, and matrix equations
Authors: Li Chi-Kwong , Sze Nung-Sing
Published: May 2008

The results on matrix canonical forms are used to give a complete description of the higher rank numerical range of matrices arising from the study of quantum error correction. It is shown that the set can be obtained as the intersection of closed half planes (of complex numbers). As a result, it is always a convex set inC\mathbb {C}. Moreover, the higher rank numerical range of a normal matrix is a convex polygon determined by the eigenvalues. These two consequences confirm the conjectures of Choi et al. on the subject. In addition, the results are used to derive a formula for the optimal upper bound for the dimension of a totally isotropic subspace of a square matrix and to verify the solvability of certain matrix equations.
The New Deal Order
Authors: Smith Jason Scott
Published: May 2008

This essay explores how historians and others have used the concept of political economy, arguing that its application to United States history between the 1920s and 1940s helps to clarify the relationships between politics, the economy, and liberalism.
Bacterial Blight, a New Disease of Broccoli Caused by Pseudomonas syringae in California
Authors: Koike S. T. , Cintas N. A. , Bull C. T.
Published: May 2008

In 1998 and 1999, a new disease was detected in commercial broccoli (Brassica oleracea var. botrytis) grown in the Salinas Valley, Monterey County, CA.

Posted 1 June 2000.
Natural Outbreak of a Bacterial Fruit Rot of Cantaloupe in Georgia Caused by Acidovoraxavenae subsp. citrulli
Authors: Walcott R. R. , Langston D. B. , JSanders F. H. , Gitaitis R. D. , Flanders J. T.
Published: May 2008

In April and July 1999, cantaloupe plants (Cucumis melo) from commercial greenhouses and fields in Grady, Colquitt, Mitchell, and Tift counties, GA, exhibited severe foliar necrosis and a fruit rot.

Posted 2 June 2000.
Pittosporum tobira: A New Host for Tomato spotted wilt virus in Israel
Authors: Gera A. , Kritzman A. , Cohen J.
Published: May 2008

In July 1998, Pittosporum tobira shrubs, grown in a nursery in the Sharon Valley of Israel, developed foliar ring spots, mild mosaic, and tip necrosis. Of 15 samples tested for the presence of Tomato spotted wilt virus (TSWV) with a commercially available enzyme-linked immunosorbent assay (ELISA) kit (Loewe Biochemica, Otterfing, Germany), 14 were positive for TSWV.

Posted 5 June 2000.
New Natural Hosts of Tomato spotted wilt virus in Spain
Authors: Jordá C. , Font I. , Lázaro A. , Juarez M. , Ortega A. , Lacasa A.
Published: May 2008

Tomato spotted wilt virus (TSWV) has caused epidemics in recent years in many crops throughout the Mediterranean Region. Tomato, pepper, and lettuce are the crops most affected in Spain.

Posted 5 June 2000.
Lupins, a New Host of Phytophthora erythroseptica in Spain
Authors: Trapero-Casas A. , Rodríguez-Tello A. , Kaiser W. J.
Published: May 2008

Several lupin (Lupinus) species are native to southern Spain. The white lupin, Lupinus albus L., is the most important crop, and its seeds are used for human consumption and animal feed.

Posted 9 June 2000.
Return of an Old Problem: Fusarium Head Blight of Small Grains
Authors: Stack Robert W.
Published: May 2008

Several species of fungus cause Fusarium Head Blight (FHB), but F. graminearum has been important in the US. The mixture of maize, wheat and barley production, and use of reduced tillage and increased residue retention encourage epidemics of FHB. Strong interest in use of fungicide sprays continues but the complete answer remains elusive. Molecular marker-assisted plant breeding is being used to breed for FHB resistance.

Posted 22 June 2000.
Contaminants and Injury Induce Inking on Peaches and Nectarines
Authors: Crisosto Carlos H. , Johnson R. Scott , Day Kevin R. , Beede Bob , Andris Harry
Published: May 2008

After 3 years of study, we have demonstrated that physical injury combined with contamination cause skin discoloration, called inking, on peaches and nectarines. Abrasion damage releases anthocyanin/phenolic pigments, which are located in the skin cells, allowing the reaction of these pigments with the heavy-metal contaminants. We found that iron, copper and aluminum were the most deleterious contaminants of those studied in inducing inking on abraded fruit. Approximately 10 ppm iron was enough to induce inking at the physiological fruit pH (~3.5). This contamination can occur within 15 days before harvest, or during harvest or packing operations. Foliar-nutrient, fungicide and insecticide preharvest sprays may act as sources of contamination for inking development, depending on the preharvest application interval. To reduce inking incidence, we have developed safe preharvest application intervals that yield low inking incidence benomyl for iprodione (Rovral), triforine (Funginex), vinclozolin (Ronilan DF) (Benlate) and certain foliar nutrients containing heavy metals.

Posted 25 June 2000.
Managing Powdery Mildew of Cherry in Washington Orchards and Nurseries with Spray Oils
Authors: Grove G. G. , Boal R. J. , Bennett L. H.
Published: May 2008

Powdery mildew of sweet cherry is the most serious disease in irrigated orchards and nurseries of Washington. The fungus infects foliage and fruit, but fruit infections are of primary concern due to the potential for rejection of entire crops. Development of resistance to demethylation inhibiting (DMI) fungicides in the mid-1990s increased the difficulty in controlling this disease. Orchard mildew management programs that utilize oils, DMI and strobilurin fungicides have been developed for use in eastern Washington. A growth stage (phenology)/calendar-based program provides excellent disease control, utilizes three fungicidal modes of action, and minimizes oil-induced fruit and foliar phytotoxicity by limiting oil use to no later than the pit hardening stage. A second approach that utilizes oils in a temperature-based disease forecasting system provides excellent disease control with fewer fungicide applications.

Accepted for publication 19 July 2000. Published 28 July 2000.
Outbreak of Smut Caused by Tilletia maclaganiion Cultivated Switchgrass in Iowa
Authors: Gravert C. E. , Tiffany L. H. , Munkvold G. P.
Published: May 2008

Switchgrass (Panicum virgatum L.), a prairie grass native to Iowa, is cultivated for forage and biomass production. During the late 1990s, biomass and seed yields of switchgrass grown in southern Iowa began to decline, and the reduction has been attributed to unidentified diseases.

Posted 15 August 2000.
Outbreak of Eremothecium coryli Fruit Rot of Tomato in California
Authors: Miyao G. M. , Davis R. M. , Phaff H. J.
Published: May 2008

A ripe fruit rot of tomato (Lycopersicon esculentum) associated with stink bug (Euschistus conspersus) feeding caused extensive losses in the Sacramento Valley of California in 1998.

Posted 16 August 2000.