bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of shallow groundwater flow systems in areas of degrading permafrost
Authors: Bense V. F. , Ferguson G. , Kooi H.
Published: November 2009

The recent increase in fresh‐water discharge during low‐flow conditions as observed in many (sub‐)Arctic Rivers has been attributed to a reactivation of groundwater flow systems caused by permafrost degradation. Hydrogeological simulations show how groundwater flow conditions in an idealized aquifer system evolve on timescales of decades to centuries in response to climate warming scenarios as progressive lowering of the permafrost table establishes a growing shallow groundwater flow system. Ultimately, disappearance of residual permafrost at depth causes a sudden establishment of deep groundwater flow paths. The projected shifts in groundwater flow conditions drive characteristic non‐linear trends in the evolution of increasing groundwater discharge to streams. Although the subsurface distribution of ice will markedly influence the system response, current modeling results suggest that late‐stage accelerations in base flow increase of streams and rivers, are to be expected, even if surface air temperatures stabilize at the current levels in the near future.
Element-specific magnetometry of EuS nanocrystals
Authors: Selinsky Rachel S. , Keavney David J. , Bierman Matthew J. , Jin Song
Published: November 2009

A soft x-ray absorption and x-ray magnetic circular dichroism (XMCD) study of the ferromagnetism in solution-grown EuS nanocrystals (NCs) is reported. The absorption edges of Eu M5 and M4, S K, O K, and P K were probed to determine elementally specific contributions to the magnetism of EuS NCs. Differential spin absorption was observed by XMCD at the Eu M5,4 edges confirming the presence of a magnetic moment on the Eu2+ 4f shell. No dichroic signal was observed for S, O, or P. Vibrating sample magnetometry of ensembles of NCs shows ferromagnetic properties consistent with the XMCD studies.
Stability of binary mixtures in electric field gradients
Authors: Samin Sela , Tsori Yoav
Published: November 2009

We consider the influence of electric field gradients on the phase behavior of nonpolar binary mixtures. Small fields give rise to smooth composition profiles, whereas large enough fields lead to a phase-separation transition. The critical field for demixing as well as the equilibrium phase-separation interface are given as a function of the various system parameters. We show how the phase diagram in the temperature-composition plane is affected by electric fields, assuming a linear or nonlinear constitutive relations for the dielectric constant. Finally, we discuss the unusual case where the interface appears far from any bounding surface.
Dynamic rheology of sphere- and rod-based magnetorheological fluids
Authors: de Vicente J. , Segovia-Gutiérrez J. P. , Andablo-Reyes E. , Vereda F. , Hidalgo-Álvarez R.
Published: November 2009

The effect of particle shape in the small amplitude oscillatory shear behavior of magnetorheological (MR) fluids is investigated from zero magnetic field strengths up to 800 kA/m. Two types of MR fluids are studied: the first system is prepared with spherical particles and a second system is prepared with rodlike particles. Both types of particles are fabricated following practically the same precipitation technique and have the same intrinsic magnetic and crystallographic properties. Furthermore, the distribution of sphere diameters is very similar to that of rod thicknesses. Rod-based MR fluids show an enhanced MR performance under oscillatory shear in the viscoelastic linear regime. A lower magnetic field strength is needed for the structuration of the colloid and, once saturation is fully achieved, a larger storage modulus is observed. Existing sphere- and rod-based models usually underestimate experimental results regarding the magnetic field strength and particle volume fraction dependences of both storage modulus and yield stress. A simple model is proposed here to explain the behavior of microrod-based MR fluids at low, medium and saturating magnetic fields in the viscoelastic linear regime in terms of magnetic interaction forces between particles. These results are further completed with rheomicroscopic and dynamic yield stress observations.
Threshold fields in the dc bias dependence of dielectric responses of relaxor ferroelectric terpolymer films
Authors: Meng X. J. , Dkhil B. , Liu P. F. , Wang J. L. , Sun J. L. , Chu J. H.
Published: November 2009

The dc bias dependence of dielectric properties has been investigated for poly (vinylindene fluoride-trifluoroethylene-chlorofluoroethylene) relaxor terpolymer films. The frequency dependence of the temperature of the permittivity maximum, Tm, was analyzed using the Vogel–Fulcher (VF) relation. Two threshold fields, ∼30 and 160 MV/m were found in the electric-field dependence of Tm. Tm shows a minimum at ∼30 MV/m and a maximum at ∼160 MV/m. The VF parameters activation energy Ea and freezing temperature Tf respectively show a maximum and a minimum at ∼25 MV/m.
Study of acoustic wave behavior in silicon-based one-dimensional phononic-crystal plates using harmony response analysis
Authors: Zhu Xuefeng , Xu Tao , Liu Shengchun , Cheng Jianchun
Published: November 2009

We promote an efficient method named harmony response analysis (HRA) as a comparison with transient response analysis and supercell plane wave expansion (supercell PWE) to study the behavior of Lamb wave in silicon-based one-dimensional composite plates. To implement HRA for dealing with Lamb waves in phononic-crystal plates, the viscous-spring artificial boundaries are employed to eliminate the boundary reflection in maximum. With the calculation of displacement field, the propagations of elastic waves under different frequency loads (inside/outside the completed band gap) are investigated in details. The method is then applied in plates both with and without substrate. We further study the plates with quasiperiodicity (generalized Fibonacci systems and double-period system) and investigate the change in band gaps induced by the quasiperiodicity.
Dielectric, ferroelectric, and piezoelectric behaviors of AgNbO3–KNbO3 solid solution
Authors: Fu Desheng , Itoh Mitsuru , Koshihara Shin-ya
Published: November 2009

Phase evolution in the (Ag1−xKx)NbO3 (AKN) solid solution was investigated by x-ray diffraction, dielectric, and ferroelectric measurements. At room temperature, there are three phase boundaries at xc1≈0.07, xc2≈0.20, and xc3≈0.8. When xc1<x, AKN transforms from the AgNbO3-type orthorhombic phase with a weak ferroelectricity into a new orthorhombic phase with a strong ferroelectricity. This ferroelectric phase is stable for xc1<x<xc2, and shows a nearly composition-independent Curie point of 525 K and a very large polarization (Pr=20.5 μC/cm2 for a ceramics sample of x=0.1). When xc2<x<xc3, single-phase AKN was not available. When xc3<x, AKN adopts the KNbO3-type orthorhombic structure and shows similar successive phase transitions to pure KNbO3. Its Curie point increases linearly with x from 633 K for x=0.80 to 696 K for x=1.00. We obtained a strain level of ≈0.05% and a d33 value of 46–64 pC/N for the AKN ceramics samples. The relationship between the structural change and ferroelectric phase evolution is also discussed briefly.
Effects of the alkyl chain length in phosphonic acid self-assembled monolayer gate dielectrics on the performance and stability of low-voltage organic thin-film transistors
Authors: Fukuda Kenjiro , Hamamoto Takanori , Yokota Tomoyuki , Sekitani Tsuyoshi , Zschieschang Ute , Klauk Hagen , Someya Takao
Published: November 2009

We have fabricated pentacene organic thin-film transistors (TFTs) using self-assembled monolayers (SAMs) based on alkyl-phosphonic acids with five different alkyl chain lengths as the gate dielectric and investigated the relationship between the SAM chain length and the electrical performance and stability of the transistors. A SAM chain length of 14 carbon atoms provides a maximum TFT mobility of 0.7 cm2/V s, along with an on/off current ratio greater than 105. We have also investigated the bias stress effect in these TFTs and found that the change in drain current is substantially less severe than in pentacene TFTs with polymer gate dielectrics.
Effects of oxygen vacancy on ferroelectricity in Ba(Fe1/2Nb1/2)O3 thin films grown by pulsed laser deposition
Authors: Zhang Wei , Li Lei , Chen Xiang Ming
Published: November 2009

Well-crystallized Ba(Fe1/2Nb1/2)O3 thin films were grown on Pt/TiO2/SiO2/Si substrates in various oxygen pressures at 550 °C by pulsed laser deposition. X-ray diffraction analysis revealed that the thin films had a single phase of perovskite structure. The lattice constants of thin films increased obviously with decreasing the deposited oxygen pressure due to more oxygen deficiency in samples. Saturated polarization-electric-field (P-E) loops and butterfly-shaped capacitance-voltage (C-V) curves were observed in Ba(Fe1/2Nb1/2)O3 thin films at room temperature. The remnant polarization decreased with increasing the deposition oxygen pressure and was further depressed by annealing in high pressure oxygen. The oxygen vacancy played a predominant role in the ferroelectricity of Ba(Fe1/2Nb1/2)O3 thin films.
Measurement system of the refractive power of spherical and sphero-cylindrical lenses with the magnification ellipse fitting method
Authors: Ko Wooseok , Kim Soohyun
Published: November 2009

This paper proposes a new measurement system for measuring the refractive power of spherical and sphero-cylindrical lenses with a six-point light source, which is composed of a light emitting diode and a six-hole pattern aperture, and magnification ellipse fitting method. The position of the six light sources is changed into a circular or elliptical form subjected to the lens refractive power and meridian rotation angle. The magnification ellipse fitting method calculates the lens refractive power based on the ellipse equation with magnifications that are the ratios between initial diagonal lengths and measured diagonal lengths of the conjugated light sources changed by the target lens. The refractive powers of the spherical and sphero-cylindrical lenses certified in the Korea Research Institute of Standard and Science were measured to verify the measurement performance. The proposed method is estimated to have a repeatability of ±0.01D and an error value below 1%.
Study of multi-ON states in nonvolatile memory based on metal-insulator-metal structure
Authors: Yang Guanwen , Chen Hsiang-Yu , Ma Liping , Shao Yue , Yang Yang
Published: November 2009

Various mechanisms have been proposed to interpret switching effect in thermally evaporated organic memory devices. In this work, we demonstrate a nonvolatile memory device having tristates, one OFF state and two different ON states (lower-ON state, higher-ON state) in the metal-insulator-metal (MIM) structure. Detailed study has revealed that different switching mechanisms are responsible for these two stages of switching: filament formation is the dominant mechanism for switching from the OFF state to the lower ON state while Poole–Frenkel effect governs the switching from the lower-ON state to the higher-ON state.
Origins of performance in fiber-based organic photovoltaics
Authors: Li Yuan , Zhou Wei , Xue Dan , Liu Jiwen , Peterson Eric D. , Nie Wanyi , Carroll David L.
Published: November 2009

Using ray tracing and optical path iteration, we present a mathematical model for light transmission, absorption, and loss in fiber-based organic photovoltaics. Simulations based on this model give an optimum incident angle, position, and an optimum aspect ratio in terms of other parameters of the fiber photocell. Further, the predicted relationship between current generation and incident angle correlates well with experimental data for a given fiber length. Finally, we show that experimental results on current generation versus fiber diameter are well reproduced by our simulation for fiber diameters of the order of the wavelength of incident light.
Fivefold annealing twin in nanocrystalline Cu
Authors: Huang P. , Dai G. Q. , Wang F. , Xu K. W. , Li Y. H.
Published: November 2009

Fivefold annealing twin has been observed in nanocrystalline Cu at zero external stress. The microstructure of the multifold twins at various annealing temperatures has been examined by transmission electron microscopic in detail. Contrary to the well known sequential twinning mechanism, coherent twin boundaries formed via migration of grain boundary segment were proposed to be the dominant mechanism of fivefold annealing twin, which associated with grain growth during annealing. Moreover, the possibilities of the proposed mechanism may operate in forming fivefold deformation twin were discussed.
Conformations and free energy landscapes of polyproline peptides
Authors: Moradi Mahmoud , Babin Volodymyr , Roland Christopher , Darden Thomas A. , Sagui Celeste
Published: November 2009

The structure of the proline amino acid allows folded polyproline peptides to exist as both left- (PPII) and right-handed (PPI) helices. We have characterized the free energy landscapes of hexamer, nanomer, and tridecamer polyproline peptides in gas phase and implicit water as well as explicit hexane and 1-propanol for the nanomer. To enhance the sampling provided by regular molecular dynamics, we used the recently developed adaptively biased molecular dynamics method, which describes Landau free energy maps in terms of relevant collective variables. These maps, as a function of the collective variables of handedness, radius of gyration, and three others based on the peptide torsion angle ω, were used to determine the relative stability of the different structures, along with an estimate of the transition pathways connecting the different minima. Results show the existence of several metastable isomers and therefore provide a complementary view to experimental conclusions based on photo-induced electron transfer experiments with regard to the existence of stable heterogeneous subpopulations in PPII polyproline.
Rab5 Mediates Caspase-8–promoted Cell Motility and Metastasis
Authors: Torres Vicente A. , Mielgo Ainhoa , Barbero Simone , Hsiao Ruth , Wilkins John A. , Stupack Dwayne G.
Published: November 2009

Caspase-8 is a key apical sensory protein that governs cell responses to environmental cues, alternatively promoting apoptosis, proliferation, and cell migration. The proteins responsible for integration of these pathways, however, have remained elusive. Here, we reveal that Rab5 regulates caspase-8–dependent signaling from integrins. Integrin ligation leads to Rab5 activation, association with integrins, and activation of Rac, in a caspase-8–dependent manner. Rab5 activation promotes colocalization and coprecipitation of integrins with caspase-8, concomitant with Rab5 recruitment to integrin-rich regions such as focal adhesions and membrane ruffles. Moreover, caspase-8 expression promotes Rab5-mediated internalization and the recycling of β1 integrins, increasing cell migration independently of caspase catalytic activity. Conversely, Rab5 knockdown prevented caspase-8–mediated integrin signaling for Rac activation, cell migration, and apoptotic signaling, respectively. Similarly, Rab5 was critical for caspase-8–driven cell migration in vivo, because knockdown of Rab5 compromised the ability of caspase-8 to promote metastasis under nonapoptotic conditions. These studies identify Rab5 as a key integrator of caspase-8–mediated signal transduction downstream of integrins, regulating cell survival and migration in vivo and in vitro.
Sub‐millimolar concentration of the novel phenol‐based compound, 2‐hydroxy benzoate zinc, induces apoptosis in human HT‐1080 fibrosarcoma cells
Authors: Mahdi J. G. , Pepper C. J. , Alkarrawi M. A. , Mahdi A. J. , Bowen I. D.
Published: November 2009

Objectives:  To examine the effect of a novel phenolic‐based compound, 2‐hydroxy benzoate zinc (2HBZ), and acetylsalicylic acid (ASA) on human HT‐1080 fibrosarcoma cells.

Materials and methods:  MTT assay was used to assess cell proliferation while different methods were used to detect apoptosis morphologically and immunohistochemically in Human HT‐1080 fibrosarcoma cells. Apoptosis was determined by Annexine‐V labelling, and caspase‐3 activation. In addition, western blot was used to analyse p21, p53 and Bax and flow cytometry was to analyse the cell cycle.

Results:  2HBZ exhibited a more than 5‐fold increase in cytotoxic potency when compared with ASA with mean LD50 values of 210 and 1100 lM respectively (P < 0.0001). The cytotoxic effects of 2HBZ were both time‐ and dosedependent with marked apoptosis being evident only after 24 h at concentrations as low as 200 mM. In contrast, ASA‐induced apoptosis was observed only at concentrations in excess of 1000 mM at the same time point. Both 2HBZ and ASA induced caspase‐3 activation in the cells, which confirmed that their cytotoxic effects were the result of apoptotic cell death. These findings were further confirmed by immunomorphological studies for the detection of apoptosis including haematoxylineosin, methyl green/pyronin Y staining and scanning electron microscopy. In addition, 2HBZ caused a marked increase in p21, p53 and Bax protein expressions and these effects were associated with an increase in G1 and G2 arrest of the cell cycle and a reduction in S‐phase.

Conclusions:  These results demonstrate that the novel phenolic compound 2HBZ is a potent apoptosis‐inducing agent in HT‐1080 cells and warrants further investigation as a potential chemotherapeutic agent in primary cancer cell models.
Calcineurin inhibitors affect B cell antibody responses indirectly by interfering with T cell help
Authors: Heidt S , Roelen D L , Eijsink C , Eikmans M , Van Kooten C , Claas F H J , Mulder A
Published: November 2009

In general, humoral immune responses depend critically upon T cell help. In transplantation, prevention or treatment of humoral rejection therefore require drugs that ideally inhibit both B cell and T helper cell activity. Here, we studied the effects of commonly used immunosuppressive drugs [tacrolimus, cyclosporin, mycophenolic acid (MPA) and rapamycin] on T cell helper activity and on T cell-dependent B cell responses. T cells were activated polyclonally in the presence of immunosuppressive drugs in order to analyse the effect of these drugs on T cell proliferation, co-stimulatory ligand expression and cytokines. The impact of immunosuppressive drugs on T cell-dependent immunoglobulin production by B cells was addressed in T–B cell co-cultures. All drugs affected T cell proliferation and attenuated T cell co-stimulatory ligand (CD154 and CD278) expression when T cells were activated polyclonally. Tacrolimus, cyclosporin and rapamycin also attenuated B cell stimulatory cytokine mRNA levels in T cells. As a consequence, a decrease in immunoglobulin levels was observed in autologous T–B cell co-cultures, where T cell help is essential for immunoglobulin production. In contrast, when pre-activated T cells were used to stimulate autologous B cells, calcineurin inhibitors failed to inhibit B cell immunoglobulin production, whereas MPA and rapamycin did show inhibition. From these studies, it is evident that calcineurin inhibitors affect the humoral immune response by interfering with T helper signals, but not by targeting B cells directly. Furthermore, our studies support the necessity of intervening in T cell helper function to attenuate humoral responses.
Plankton response to weakening of the Iberian coastal upwelling
Authors: PÉREZ FIZ F. , PADÍN XOSÉ A. , PAZOS YOLANDA , GILCOTO MIGUEL , CABANAS MANUEL , PARDO PAULA C. , DOVAL Ma DOLORES , FARINA‐BUSTO LUIS
Published: November 2009

Coastal upwelling regions, which are affected by equatorward‐wind variability, are among the most productive areas of the oceans. It has been suggested that global warming will lead to a general strengthening of coastal upwelling, with important ecological implications and an impact on fisheries. However, in the case of the Iberian upwelling, the long‐term analysis of climatological variables described here reveals a weakening in coastal upwelling. This is linked to a decrease of zonal sea level pressure gradient, and correlated with an observed increase of sea surface temperature and North Atlantic Oscillation. Weakening of coastal upwelling has led to quantifiable modifications of the ecosystem. In outer shelf waters a drop in new production over the last 40 years is likely related to the reduction of sardine landings at local harbors. On the other hand, in inner shelf and Ria waters, the observed weakening of upwelling has slowed down the residual circulation that introduces nutrients to the euphotic layer, and has increased the stability of the water column. The drop in nutrient levels has been compensated by an increase of organic matter remineralization. The phytoplankton community has responded to those environmental trends with an increase in the percentage of dinoflagellates and Pseudonitzschia spp. and a reduction in total diatoms. The former favors the proliferation of harmful algal blooms and reduces the permitted harvesting period for the mussel aquaculture industry. The demise of the sardine fishery and the potential threat to the mussel culture could have serious socio‐economic consequences for the region.
An integrated risk assessment for climate change: analysing the vulnerability of sharks and rays on Australia's Great Barrier Reef
Authors: CHIN ANDREW , KYNE PETER M. , WALKER TERENCE I. , McAULEY RORY B.
Published: November 2009

An Integrated Risk Assessment for Climate Change (IRACC) is developed and applied to assess the vulnerability of sharks and rays on Australia's Great Barrier Reef (GBR) to climate change. The IRACC merges a traditional climate change vulnerability framework with approaches from fisheries ecological risk assessments. This semi‐quantitative assessment accommodates uncertainty and can be applied at different spatial and temporal scales to identify exposure factors, at‐risk species and their key biological and ecological attributes, critical habitats a`nd ecological processes, and major knowledge gaps. Consequently, the IRACC can provide a foundation upon which to develop climate change response strategies. Here, we describe the assessment process, demonstrate its application to GBR shark and ray species, and explore the issues affecting their vulnerability to climate change. The assessment indicates that for the GBR, freshwater/estuarine and reef associated sharks and rays are most vulnerable to climate change, and that vulnerability is driven by case‐specific interactions of multiple factors and species attributes. Changes in temperature, freshwater input and ocean circulation will have the most widespread effects on these species. Although relatively few GBR sharks and rays were assessed as highly vulnerable, their vulnerability increases when synergies with other factors are considered. This is especially true for freshwater/estuarine and coastal/inshore sharks and rays. Reducing the impacts of climate change on the GBR's sharks and rays requires a range of approaches including mitigating climate change and addressing habitat degradation and sustainability issues. Species‐specific conservation actions may be required for higher risk species (e.g. the freshwater whipray, porcupine ray, speartooth shark and sawfishes) including reducing mortality, preserving coastal catchments and estuarine habitats, and addressing fisheries sustainability. The assessment identified many knowledge gaps concerning GBR habitats and processes, and highlights the need for improved understanding of the biology and ecology of the sharks and rays of the GBR.
Mediterranean warming triggers seagrass (Posidonia oceanica) shoot mortality
Authors: MARBÀ NÚRIA , DUARTE CARLOS M.
Published: November 2009

Rapid warming of the Mediterranean Sea threatens marine biodiversity, particularly key ecosystems already stressed by other impacts such as Posidonia oceanica meadows. A 6‐year monitoring of seawater temperature and annual P. oceanica shoot demography at Cabrera Archipelago National Park (Balearic Islands, Western Mediterranean) allowed us to determine if warming influenced shoot mortality and recruitment rates of seagrasses growing in relative pristine environments. The average annual maximum temperature for 2002–2006 was 1 °C above temperatures recorded in 1988–1999 (26.6 °C), two heat waves impacted the region (with seawater warming up to 28.83 °C in 2003 and to 28.54 °C in 2006) and the cumulative temperature anomaly, above the 1988–1999 mean annual maximum temperature, during the growing season (i.e. degree‐days) ranged between 0 °C in 2002 and 70 °C in 2003. Median annual P. oceanica shoot mortality rates varied from 0.067 year−1 in 2002 to 0.123 year−1 in 2003, and exceeded recruitment rates in all stations and years except in shallow stations for year 2004. Interannual fluctuations in shoot recruitment were independent of seawater warming (P>0.05). P. oceanica meadows experienced a decline throughout the study period at an average rate of −0.050±0.020 year−1. Interannual variability in P. oceanica shoot mortality was coupled (R2>0.40) to seawater warming variability and increasing water depth: shoot mortality rates increased by 0.022 year−1 (i.e. an additional 2% year−1) for each additional degree of annual maximum temperature and by 0.001 year−1 (i.e. 0.1% year−1) for each accumulated degree water temperature remained above 26.6 °C during the growing season. These results demonstrate that P. oceanica meadows are highly vulnerable to warming, which can induce steep declines in shoot abundance as well indicating that climate change poses a significant threat to this important habitat.
A new reliable tool (PVCassess) for assessment of peripheral venous catheters
Authors: Ahlqvist Margary , Berglund Britta , Nordstrom Gun , Klang Birgitta , Wirén Mikael , Johansson Eva
Published: November 2009

Rationale and aims To evaluate the extensive use of peripheral venous catheters (PVCs), including catheter‐related complications, a reliable tool for PVC assessment is needed. The aim of this study was to develop such a tool to evaluate PVCs in relation to management, documentation and signs and symptoms of thrombophlebitis (TH), as well as to determine its inter‐rater and test‐retest reliability.

Method The tool development included confirmation of content and face validity. Two groups of registered nurses used the new tool (PVCassess) to assess PVC management and signs of TH independently. Group A (n = 3) assessed 26 items in 67 PVCs bedside (inter‐rater reliability). Group B (n = 3) assessed photographs (67 PVCs, 21 items) of the same PVCs as those in Group A with a 4‐week interval (test‐retest reliability). Proportion of agreement P(A) and Cohen's kappa were calculated to evaluate inter‐rater and test‐retest reliability.

Results Among nurses assessing PVCs at bedside, the P(A) was good to excellent (0.80–1) in 96% of the items in PVCassess. In 80% of the items kappa was substantial to almost perfect (0.61–1). TH sign erythema fell into the fair range (kappa = 0.40). In test‐retest reliability analysis the P(A) was within the good and excellent range (0.80–1.0) and kappa varied from moderate to almost perfect (0.41–1.0) in 95% of the items. One item ‘outer dressing is clean’ was in fair range (0.21–0.40).

Conclusions The PVCassessinstrument shows satisfactory inter‐rater and test‐retest reliability. Reliability tests on reviewing documentation remain to be performed.
Identification of bloodmeals in Anopheles quadrimaculatus and Anopheles punctipennis from eastern equine encephalitis virus foci in northeastern U.S.A.
Authors: MOLAEI G. , FARAJOLLAHI A. , ARMSTRONG P. M. , OLIVER J. , HOWARD J. J. , ANDREADIS T. G.
Published: November 2009

The host‐feeding patterns of Anopheles quadrimaculatus Say and Anopheles punctipennis (Say) were examined in order to evaluate their potential contributions to the transmission of eastern equine encephalitis virus (EEEv) and other arboviruses in the northeastern U.S.A. Engorged mosquitoes of the two species were collected from EEEv foci in central New York (NY) and throughout New Jersey (NJ), and their bloodmeals were identified using a polymerase chain reaction (PCR)‐based assay and sequencing portions of the mitochondrial cytochrome b gene. Analysis of 131 An. quadrimaculatus and 107 An. punctipennis from NY revealed that 97.7% and 97.2%, respectively, had acquired blood solely from mammalian hosts. Similarly, examination of 288 An. quadrimaculatus and 127 An. punctipennis from NJ showed 100% and 96.0%, respectively, contained mammalian‐derived bloodmeals. Mosquitoes containing mixed bloodmeals from both avian and mammalian hosts were detected in 1.6% of An. quadrimaculatus from NY, and 2.8% and 4.0% of An. punctipennis from NY and NJ, respectively. White‐tailed deer (Odocoileus virginianus) constituted the most common vertebrate host for these anopheline mosquitoes, accounting for 85.8–97.7% of all bloodmeals identified. The predominance of white‐tailed deer as a source of bloodmeals supports enzootic amplification of deer‐associated arboviruses in this region, including Jamestown Canyon, Cache Valley and Potosi viruses. One horse‐ and two human‐derived bloodmeals were also detected in An. quadrimaculatus collected in NJ. Limited avian‐derived bloodmeals were detected from mourning dove (Zenaida macroura), sharp‐shinned hawk (Accipiter striatus) and house finch (Carpodacus mexicanus), mostly in mixed bloodmeals. Occasional feeding on avian hosts suggests that these mosquitoes may participate as epizootic–epidemic bridge vectors of EEEv from viraemic birds to mammalian hosts of concern, including horses and humans. An isolate of EEEv was recovered from the head and thorax of an An. punctipennis mosquito collected in NY.
Parasitism byCuscuta pentagonasequentially induces JA and SA defence pathways in tomato
Authors: RUNYON JUSTIN B. , MESCHER MARK C. , FELTON GARY W. , DE MORAES CONSUELO M.
Published: November 2009

While plant responses to herbivores and pathogens are well characterized, responses to attack by other plants remain largely unexplored. We measured phytohormones and C18fatty acids in tomato attacked by the parasitic plantCuscuta pentagona, and used transgenic and mutant plants to explore the roles of the defence‐related phytohormones salicylic acid (SA) and jasmonic acid (JA). Parasite attachment to 10‐day‐old tomato plants elicited few biochemical changes, but a second attachment 10 d later elicited a 60‐fold increase in JA, a 30‐fold increase in SA and a hypersensitive‐like response (HLR). Host age also influenced the response: neitherCuscutaseedlings nor established vines elicited a HLR in 10‐day‐old hosts, but both did in 20‐day‐old hosts. Parasites grew larger on hosts deficient in SA (NahG) or insensitive to JA [jasmonic acid‐insensitive1(jai1) ], suggesting that both phytohormones mediate effective defences. Moreover, amounts of JA peaked 12 h before SA, indicating that defences may be coordinated via sequential induction of these hormones. Parasitism also induced increases in free linolenic and linoleic acids and abscisic acid. These findings provide the first documentation of plant hormonal signalling induced by a parasitic plant and show that tomato responses toC. pentagonadisplay characteristics similar to both herbivore‐ and pathogen‐induced responses.
Conserving water in and applying solar power to haemodialysis: ‘Green Dialysis’ through wiser resource utilization
Authors: AGAR JOHN WM
Published: November 2009

Natural resources are under worldwide pressure, water and sustainable energy being the paramount issues. Haemodialysis, a water‐voracious and energy‐hungry healthcare procedure, thoughtlessly wastes water and leaves a heavy carbon footprint. In our service, 100 000 L/week of previously discarded reverse osmosis reject water – water which satisfies all World Health Organisation criteria for potable (drinking) water – no longer drains to waste but is captured for reuse. Reject water from the hospital‐based dialysis unit provides autoclave steam for instrument sterilization, ward toilet flushing, janitor stations and garden maintenance. Satellite centre reject water is tanker‐trucked to community sporting fields, schools and aged‐care gardens. Home‐based nocturnal dialysis patient reuse reject water for home domestic utilities, gardens and animal watering. Although these and other potential water reuse practices should be mandated through legislation for all dialysis services, this is yet to occur. In addition, we now are piloting the use of solar power for the reverse osmosis plant and the dialysis machines in our home dialysis training service. If previously attempted, these have yet to be reported. After measuring the power requirements of both dialytic processes and modelling the projected costs, a programme has begun to solar power all dialysis‐related equipment in a three‐station home haemodialysis training unit. Income‐generation with the national electricity grid via a grid‐share and reimbursement arrangement predicts a revenue stream back to the dialysis service. Dialysis services must no longer ignore the non‐medical aspects of their programmes but plan, trial, implement and embrace ‘green dialysis’ resource management practices.
Preparing for the World Risk Society: Towards a New Security Paradigm for the European Union
Authors: Boin Arjen , Ekengren Magnus
Published: November 2009

The world of crises and disasters is changing rapidly. We are witnessing new types of adversity. In addition, modern societies have become increasingly vulnerable to disruptions, new and old. This new world demands new types of responses, which nation states cannot produce alone. Nation states will have to cooperate to protect their citizens from these threats. This article investigates the role of the European Union in the development of new safety and security arrangements. It identifies conceptual building blocks for a new security paradigm and offers design principles that can facilitate a shared way of thinking and acting in the safety and security domain.
Coping with Macro‐Structural Adversity: Chronic Poverty, Female Youth Gangs, and Cultural Resilience in a US African‐American Urban Community
Authors: Fleisher Mark
Published: November 2009

Studies of cultural resilience concentrate on socio‐cultural processes that allow societies to resist the erosive strain of socio‐economic marginality and in response create social networks that provide cultural resilience. This study of a chronically poor, United States (U.S.) African‐American urban community in Champaign, Illinois, examines the community's adaptation to structurally generated socioeconomic marginality. This study finds that the theory of balanced, socioeconomic exchange relations helps to understand the intricate social dynamics of cultural resilience. The adaptive advantage of balanced exchange relationships are confirmed by an empirical analysis of personal social network data gathered female gang members.
Lost in translation: barriers to learning in health professional clinical education
Authors: Newton Jennifer M. , Billett Stephen , Jolly Brian , Ockerby Cherene M.
Published: November 2009

The perennial debate concerning the so‐called ‘theory‐practice gap’ pervades health professional education. It is uncertain whether this gap – the notion that knowledge gained in university does not translate well into the workplace – is unavoidable or if it is a manifestation of the learning approaches used and the cultures operative in the two locations. This paper examines how nursing students’ knowledge and skills gained within university clinical laboratories transfer into the reality of the clinical environment. A series of one‐on‐one interviews were conducted over a two year period with second and third year nursing students (n = 28) participating in a preceptorship clinical placement model at one healthcare organisation. This paper focuses on data from the students' first interview. Data were transcribed and imported into NVivo 8 for thematic analysis. Four key themes emerged, including: ‘How I learn’ which focuses on students’ perceptions of their learning preferences; ‘Lack of engagement – it’s not real’ which concerns a perceived lack of authenticity of clinical laboratories; ‘Lack of affordances’ relating to the learning opportunities available in the clinical setting; and ‘Teacher Impact’ which focuses on the influence of individual teachers on student learning. The ‘parallel universes’ of academia and the workplace create dissonance for students as they juxtapose the authenticity of the clinical laboratories with the reality of professional healthcare practice. Transfer is inextricably linked with the individuals’ learning preferences, the affordances the workplace offers to students, and the willingness of staff to provide exciting, engaging learning opportunities. The challenge for health professional education is to provide a model of clinical education that meets not only the needs of university and clinical staff, but most importantly, the needs of students.
The Use of Clinical Scales in Depicting Cerebrovascular Complications in Bacterial Meningitis
Authors: Merkelbach Stefan , König Jochem , Röhn Sonja , Müller Martin
Published: November 2009

To evaluate the utility of different scales for clinical assessment, over time, in acute bacterial meningitis, the authors investigated 53 consecutive patients (mean age 53 ± 17 years). Clinical status on days 1, 3, 5, 8, and 14 after admission was determined by the Scandinavian Stroke Scale (SSS), Glasgow Coma Scale (GCS), and Hunt and Hess Scale (HH), and, on day 21, by the Glasgow Outcome Scale (GOS). Transcranial Doppler examinations were performed serially to assess for disease‐related arterial narrowing. This was observed in 27 patients (51%) within 2 weeks of admission. All scales were observed to correlate with the 21‐day GOS. Patients with cerebral arterial narrowing had significantly decreased SSS scores between days 1 and 8 and worse GCS and HH scores between days 3 and 5. Mean blood flow velocity in the middle cerebral artery on days 5 and 8 significantly correlated with GOS (r= 0.268, P < .008; r=−0.324, P < .003, respectively). The use of such clinical scales allows standardized assessment of patients with bacterial meningitis and provides prognostic information. Cerebral arterial narrowing was observed to correlate with neurologic impairment.
Middle Cerebral Artery Flow Velocity Correlates With Common Carotid Artery Volume Flow Rate After CO2 Inhalation
Authors: Ratanakorn Disya , Greenberg Jason P. , Meads Dana B. , Tegeler Charles H.
Published: November 2009

Cerebral vasoreactivity can be studied with transcranial Doppler (TCD) by monitoring CO2‐induced middle cerebral artery (MCA) velocity changes. Expected MCA mean velocity (Vm) changes due to changes in end‐expiratory CO2(EE‐CO2) are established, but reactivity of common carotid artery (CCA) volume flow rate (VFR) has not been extensively reported. The authors assess the relationship between MCA Vm, CCA VFR, and EE‐CO2. Ten normal individuals without cerebrovascular disease and with CCA diameters of more than 3.0 mm were studied. CCA VFR was obtained by Color Velocity Imaging Quantification and ipsilateral MCA Vm by standard TCD methods. Each side was studied before, during, and after inhalation of 5% CO2. EE‐CO2, blood pressure, and pulse rate were monitored. Four women and 6 men with mean age of 36 years were included. Significant correlations between MCA Vm and EE‐CO2, CCA VFR and EE‐CO2, and MCA Vm and CCA VFR were found. MCA Vm and CCA VFR increased 5.2% and 4.3% per mm Hg increase in EE‐CO2, respectively. MCA Vm increased 0.3 cm/s per ml/min increase in CCA VFR. In normal individuals, there is a direct correlation between MCA Vm, CCA VFR, and EE‐CO2. Measurement of CCA VFR changes during CO2inhalation may be an alternative method to estimate cerebral vasoreactivity when the MCA velocity cannot be obtained because of inadequate acoustic temporal windows.
Ophthalmic Artery Flow Direction on Color Flow Duplex Imaging Is Highly Specific for Severe Carotid Stenosis
Authors: Reynolds Patrick S. , Greenberg Jason P. , Lien Li‐Ming , Meads Dana C. , Myers Lawrence G. , Tegeler Charles H.
Published: November 2009

Background/Purpose. Collateral flow patterns are important risk factors for brain ischemia in the presence of internal carotid artery (ICA) stenosis or occlusion. Ophthalmic artery (OA) flow reversal, routinely studied by transcranial Doppler sonography, is an important marker for high‐grade ICA stenosis or occlusion. The authors sought to define the value of assessing OA flow direction with color flow duplex ultrasonography (CDUS) in the setting of significant ICA disease. Methods. Of all patients having routine carotid ultrasound in the neurosonology laboratory between July 1995 and November 2000, 152 had both carotid and orbital (OA flow direction by reduced power orbital CDUS) examinations as well as angiographic confirmation of stenosis to which North American Symptomatic Carotid Endarterectomy Trial criteria could be applied. Degree of angiographic stenosis in these 152 patients (304 arteries) was correlated with OA flow direction. Results. Of 304 arteries, 101 had greater than 80% stenosis by angiogram. In 56 of these 101 arteries with high‐grade stenosis or occlusion, the ipsilateral OA was reversed; however, OA flow direction was never reversed ipsilateral to arteries with less than 80% stenosis (sensitivity 55%, specificity 100%, negative predictive value 82%, and positive predictive value 100% for OA flow reversal as a marker of high‐grade carotid lesions). Discussion/Conclusions. OA flow direction is easily studied with CDUS. Reversed OA flow direction is highly specific (100%) for severe ipsilateral ICA stenosis or occlusion, with excellent positive predictive value, moderate negative predictive value, and limited sensitivity. OA flow reversal is not only quite specific for severe ICA disease, which may be helpful if the carotid CDUS is difficult or inadequate, but may also provide additional hemodynamic insights (ie, the inadequacy of other collateral channels such as the anterior communicating artery). OA evaluation can provide important hemodynamic information and should be included as part of carotid CDUS if there is any evidence of ICA stenosis or occlusion.
Surgical Sutures as a Means of Identifying Human Remains*
Authors: Shepherd Katy L. , Walsh‐Haney Heather , Coburn Marta U.
Published: November 2009

Abstract: The Food and Drug Administration does not require surgical sutures to be tracked by manufacturer, physician, or patient; thereby, surgical sutures have been of little use to forensic practitioners who are tasked with establishing a positive identification with biological evidence. This study demonstrates the investigative process used to pinpoint suture manufacturers by presenting a case where surgical sutures were a distinctive characteristic that aided in the positive identification of skeletal remains. The suture’s manufacturer, construction material and structure, size, and medical use was determined by contacting a local surgical suture and orthopedic implant manufacturer and utilizing publicly available manufacturer websites, which provide catalogs and specific product details. This research was one of many lines of evidence used to establish the positive identification of a 47‐year‐old male.
Changes in non‐randomness in the expanding introduced avifauna of the world
Authors: Blackburn Tim M. , Gaston Kevin J. , Parnell Mark
Published: November 2009

The identities of bird species introduced to areas beyond the limits of their native geographic ranges have historically depended on a combination of societal demands for species with certain characteristics, and the availability of species for capture, transport and release. However, both societal demands and availability have changed over time, which should also change the characteristics of species more recently added to the list of introduced birds. Here, we quantify temporal changes in selectivity of introduced bird species by comparing the characteristics of 423 species listed in the seminal catalogue of introduced birds (Long, J. L.1981. Introduced birds of the world. – David and Charles, London) with those of 122 species that have been introduced but are not listed inLong (1981). We demonstrate differences between these two groups of species in the frequencies with which different taxa are represented, in the geographic range sizes of species, and in their biogeographic regions of origin, but not in body mass. Both groups also differ from bird species in general in terms of geographic range sizes, body masses, and taxonomic composition. We relate the observed differences in the characteristics of species listed or unlisted inLong (1981)to changes in the changes in attitudes, legislation and vectors of transport relating to exotic species. We conclude by noting that the utility of published catalogues of introduced bird species is increasingly being eroded by the continued liberation and establishment of bird species.
Differences in spatial predictions among species distribution modeling methods vary with species traits and environmental predictors
Authors: Syphard Alexandra D. , Franklin Janet
Published: November 2009

Prediction maps produced by species distribution models (SDMs) influence decision‐making in resource management or designation of land in conservation planning. Many studies have compared the prediction accuracy of different SDM modeling methods, but few have quantified the similarity among prediction maps. There has also been little systematic exploration of how the relative importance of different predictor variables varies among model types and affects map similarity. Our objective was to expand the evaluation of SDM performance for 45 plant species in southern California to better understand how map predictions vary among model types, and to explain what factors may affect spatial correspondence, including the selection and relative importance of different environmental variables. Four types of models were tested. Correlation among maps was highest between generalized linear models (GLMs) and generalized additive models (GAMs) and lowest between classification trees and GAMs or GLMs. Correlation between Random Forests (RFs) and GAMs was the same as between RFs and classification trees. Spatial correspondence among maps was influenced the most by model prediction accuracy (AUC) and species prevalence; map correspondence was highest when accuracy was high and prevalence was intermediate (average prevalence for all species was 0.124). Species functional type and the selection of climate variables also influenced map correspondence. For most (but not all) species, climate variables were more important than terrain or soil in predicting their distributions. Environmental variable selection varied according to modeling method, but the largest differences were between RFs and GLMs or GAMs. Although prediction accuracy was equal for GLMs, GAMs, and RFs, the differences in spatial predictions suggest that it may be important to evaluate the results of more than one model to estimate the range of spatial uncertainty before making planning decisions based on map outputs. This may be particularly important if models have low accuracy or if species prevalence is not intermediate.