bluuebunny/crossref_metadata_2025 huggingface dataset:
Achieving Environmental Excellence through a Multidisciplinary Grassroots Movement
Authors: Herechuk Bryan , Gosse Carolyn , Woods John N.
Published: December 2010

St. Joseph's Healthcare Hamilton (SJHH) supports a grassroots green team, called Environmental Vision and Action (EVA). Since the creation of EVA, a healthy balance between corporate projects led by corporate leaders and grassroots initiatives led by informal leaders has resulted in many successful environmental initiatives. Over a relatively short period of time, environmental successes at SJHH have included waste diversion programs, energy efficiency and reduction initiatives, alternative commuting programs, green purchasing practices, clinical and pharmacy greening and increased staff engagement and awareness. Knowledge of social movements theory helped EVA leaders to understand the internal processes of a grassroots movement and helped to guide it. Social movements theory may also have broader applicability in health care by understanding the passionate engagement that people bring to a common cause and how to evolve sources of opposition into engines for positive change. After early successes, as the limitations of a grassroots movement began to surface, the EVA team revived the concept of evolving the grassroots green program into a corporate program for environmental stewardship. It is hard to quantify the importance of allowing our staff, physicians, volunteers and patients to engage in changes that they feel passionately about. However, at SJHH, the transformation of a group of people unsatisfied with the organization's environmental performance into an ‘engine for change’ has led to a rapid improvement in environmental stewardship at SJHH that is now regarded as a success.
III Those Happy Fields? DIY Landscaping
Authors: Spencer Diana
Published: December 2010

Chapter II outlined how literary pastoral scenography makes for an often visually delightful but also heavily symbolic ethnoscape, ideally suited to the exploration of red-hot political, civic, and socio-cultural issues. The signs of pastoral provide props and a set for the rustic, artful, and occasionally (naïvely) politicized figures that populate and give Roman meaning to an imaginary and leisurely rural world, superficially very different from daily life. This chapter explores how pastoral imagery can also help us to think about a different aspect of what made for enjoyable Roman space: the sight of a productive agricultural landscape.
Newly discovered parasitic Turbellaria of opisthobranch gastropods
Authors: Sudo Kosuke , Hirano Yoshiaki J. , Hirano Yayoi M.
Published: December 2010

An endoparasitic platyhelminth from six species of sacoglossan opisthobranchs was collected at several localities of temperate to subtropical waters in Japan. Poecilostomatoid copepods (all species of Splanchnotrophidae and several species of Philoblennidae) and a few digenean flukes had been the only endoparasitic metazoans known for opisthobranch hosts. The newly discovered parasite was 1 to 15 mm in length and had no eyes, mouth, pharynx, or intestine. It had no external organs for parasitic life (e.g. attachment organs) and inhabited the haemocoel of the host. When mature, it emerged from the host and secreted a silky substance around itself to form a cocoon. The cocoon contained egg capsules with 19–42 eggs. Larvae, hatched from the capsule, had a ciliated body and a pair of eye spots. They were negatively phototactic and capable of invading suitable hosts. These morphological and life history features suggest this parasitic worm may belong to the family Fecampiidae (Platyhelminthes: Turbellaria), one of a few obligate parasite taxa in Turbellaria. Molluscan hosts which are common for parasitic Platyhelminthes have not previously been known for this family. The newly discovered parasite may be important for understanding the evolution of parasitism in Platyhelminthes.
The biology and functional morphology ofModiolarca subpicta(Bivalvia: Mytilidae: Musculinae), epizoically symbiotic withAscidiella aspersa(Urochordata: Ascidiacea), from the Kattegat, northern Jutland, Denmark
Authors: Morton Brian , Dinesen Grete E.
Published: December 2010

This study of the little known north-eastern Atlantic mytilidModiolarca subpictasuggests a more intimate relationship with ascidians and, especially,Ascidiella aspersa, than has hitherto been appreciated. Both live for ~18 months and the reproductive cycle of both is approximately co-ordinated so that juvenile ascidians become available as hosts to the settling spat of the symbiotically epizoicM. subpictaeach summer. Settling spat ofM. subpictaare thought to be attracted to the exhalant flow from the ascidian's anal siphon. After the ascidian's death, the liberated mussels may adopt a wandering, free-living, lifestyle they have occasionally been reported to pursue. Anatomically,M. subpictais of the typical mytilid plan, albeit simplified commensurate upon its normal lifestyle of protective envelopment within the host's tunic. The foot, however, is highly mobile and in addition to being used for locomotion, especially in juveniles, is responsible for the planting of byssal threads, typically dorsally above the shell, so that each individual stimulates the ascidian to produce an epidermal pocket into which it manœuvres itself and reposes, securely attached, but dorsal side downModiolarca subpicta, epizoic in the tests of ascidians, could have evolved from a more isomyarian, equivalve, ancestor via a nestling, epibyssate,Trichomusculus-like shaped intermediary with ventral flattening and, hence, stability characteristic of the more familiar heteromyarian mytilids of rocky shores and lotic freshwaters being achieved through living dorsal side down.
Outbreak of acute gastroenteritis caused by adenovirus type 41 in a kindergarten
Authors: GONÇALVES G. , GOUVEIA E. , MESQUITA J. R. , ALMEIDA A. , RIBEIRO A. , ROCHA-PEREIRA J. , SÃO JOSÉ NASCIMENTO M.
Published: December 2010

In response to an alert due to epidemic gastroenteritis in children in a kindergarten, an outbreak investigation was carried out in a Portuguese municipality. The objectives were to establish an aetiological diagnosis, assess vaccine efficacy if possible, and to take corrective measures if necessary. The warden at the kindergarten was interviewed, and we visited the premises. The overall attack rate was 11·4% and most cases were mild. Stool samples from three symptomatic children were collected and screened for the presence of noroviruses, rotaviruses and adenoviruses. High vaccination coverage against rotaviruses was recorded in children aged <2 years. We initially thought that noroviruses and rotaviruses were more likely to have been the aetiological cause of the disease, but the outbreak was caused by infection with adenovirus 41. These viruses should not be overlooked in the laboratory protocol in the study of acute gastroenteritis outbreaks.
Epidemiological changes in hepatitis B prevalence in an entire population after 20 years of the universal HBV vaccination programme
Authors: SHEN L. P. , ZHANG Y. , WANG F. , ZHANG S. , YANG J. Y. , FANG K. X. , YU T. , WANG X. Y. , ZHANG W. Y. , BI S. L.
Published: December 2010

A universal hepatitis B vaccination programme has been conducted in Long An county since 1986. To investigate the epidemiological changes in hepatitis B virus (HBV) infection we conducted a serosurvey there in 2005. A total of 4686 subjects were enrolled and vaccination history and blood samples collected. HBV infective markers were determined by radioimmunoassay. The results were compared with the data of 1985. Our results show that the overall HBsAg prevalence was 7·5%, less than half of the prevalence reported in 1985. HBsAg and anti-HBc antibody prevalence in people born after 1985 decreased markedly. The gender difference in HBsAg prevalence was abolished in subjects aged <20 years. The administration of a first dose of vaccine within 24 h could reduce the HBsAg prevalence by half. In conclusion, the marked epidemiological changes in HBV prevalence found in this serosurvey indicate that the implementation of HBV vaccination was highly successful.
CLOSING THE MODEL? THE HARROD–MARSCHAK CORRESPONDENCE ON THE DRAFT OF THE “ESSAY IN DYNAMIC THEORY”
Authors: SEMBER FLORENCIA
Published: December 2010

During August and September 1938, Harrod discussed a first draft of his “Essay in Dynamic Theory” with Keynes and Marschak. The aim of this paper is to discuss Harrod’s correspondence with Marschak in the light of the subsequent interpretations of the “Essay.” Firstly, we show how Marschak focused on some of the features of Harrod’s theory that would later give rise to widely different interpretations and some misunderstandings. Three issues in particular have been broadly debated in the literature: the concept of warranted rate of growth; instability; and non-linearity. Secondly, we show that a possible reason why Harrod neglected Marschak’s remarks lies in their respective methodological approaches. While Marschak tried to frame Harrod’s theory by means of a closed model, Harrod thought that the analysis of equilibrium and of the succession of states belonged to separate stages; this made building a complete model difficult at this stage, when he was presenting a “new tool of analysis.” In spite of their respective conflicting approaches, Marschak’s comments remain of great importance, and if Harrod had followed some of his advice, his theory would probably have improved in several respects, and certainly it would have been clearer and less ambiguous.
HOW INFLUENTIAL WAS MECHANICS IN THE DEVELOPMENT OF NEOCLASSICAL ECONOMICS? A SMALL EXAMPLE OF A LARGE QUESTION
Authors: GRATTAN-GUINNESS IVOR
Published: December 2010

It is well known that classical mechanics played a significant role in the thought of several major economists in the neoclassical tradition from the 1860s to the 1910s. Less well studied are the particular parts or features of mechanics that exercised this influence, or the depth and extent of the impact. After outlining the main traditions of mechanics and the calculus, and describing types of analogy between theories in general, I review some main pertinent features of the work of eight neoclassical economists from the 1830s to the 1910s. I argue that the influence took various forms but that in practice it was modest. Then I briefly describe a fresh set of possible influences with the development of dynamical systems in the period 1920–1950, where again the role of mechanics was limited. I end by raising a large question: does economics need some mathematics designed for its own purposes rather than that traditionally obtained by analogizing from mechanics and physics?
New Viruses fromLacerta monticola(Serra da Estrela, Portugal): Further Evidence for a New Group of Nucleo-Cytoplasmic Large Deoxyriboviruses
Authors: Alves de Matos António Pedro , da Silva Trabucho Caeiro Maria Filomena Alcobia , Papp Tibor , da Cunha Almeida Matos Bruno André , Correia Ana Cristina Lacerda , Marschang Rachel E.
Published: December 2010

Lizard erythrocytic viruses (LEVs) have previously been described inLacerta monticolafrom Serra da Estrela, Portugal. Like other known erythrocytic viruses of heterothermic vertebrates, these viruses have never been adapted to cell cultures and remain uncharacterized at the molecular level. In this study, we made attempts to adapt the virus to cell cultures that resulted instead in the isolation of a previously undetectedRanavirusclosely related to FV3. TheRanaviruswas subsequently detected by polymerase chain reaction (PCR) in the blood of infected lizards using primers for a conserved portion of theRanavirusmajor capsid protein gene. Electron microscopic study of thenew Ranavirusdisclosed, among other features, the presence of intranuclear viruses that may be related to an unrecognized intranuclear morphogenetic process. Attempts to detect by PCR a portion of the DNA polymerase gene of the LEV in infected lizard blood were successful. The recovered sequence had 65.2/69.4% nt/aa% homology with a previously detected sequence from a snake erythrocytic virus from Florida, which is ultrastructurally different from the studied LEV. These results further support the hypothesis that erythrocytic viruses are related to one another and may represent a new group of nucleo-cytoplasmic large deoxyriboviruses.
Numerical simulation and mock-up experimental measurement of the air conditioning system for the 3 GeV Taiwan Photon Source electron storage ring
Authors: Chang J. C. , Tsai Z. D. , Liu C. Y. , Chung Y. C. , Chen J. R.
Published: December 2010

National Synchrotron Radiation Research Center, Taiwan, is currently constructing the civil buildings and utility system of the Taiwan Photon Source. The air conditioning (AC) system of the storage ring tunnel was designed based on those of existing Taiwan Light Source and some international advanced accelerators. To predict the air temperature variation and flow pattern in tunnel more precisely, we applied 3D computational fluid dynamics scheme and built up a one-cell mock-up equipped with AC system. In the 3D numerical model, effects of magnets of the booster and the storage ring, girders, cable trays, front ends and the supplied air wind duct are all taken into account. The temperature variations and flow pattern were shown through the numerical simulation. Measured air temperature data in the one-cell mock-up were also collected.
Upgrading beamline performance: ultra stable mirror developments at ESRF
Authors: Mairs T. , Baker R. , Clavel C. , Dabin Y. , Berard L. E. , Mattenet M. , Guillemin J.
Published: December 2010

The ESRF has now started its upgrade programme. It has become evident from the start that upgrading beamline performance implies upgrading component performance. Beam stability is seen as a key requirement for many of the proposed beamlines, but the source of (in)stabilities can be manyfold. However, one identified source is white beam mirror, and therefore, ESRF has recently invested significant amount of engineering effort to improve white beam mirror performance. The motivation for having ‘ultra stable mirrors’ at the upgrade beamline ID24 Dispersive Exafs is analysed. The design solutions for positioning, cooling and supporting the white beam mirrors for this project are presented.
Das emotionale Gedächtnis im Alter und bei Depression
Authors: Savaskan
Published: December 2010

Die Wiedererkennungsleistung für emotionale Stimuli wie z.B. menschliche Gesichtsausdrücke ist entscheidend für die Gestaltung sozialer Verhaltensweisen. Gesunde Menschen favorisieren im Erkennen und im Erinnern positive emotionale Stimuli. Mit zunehmendem Alter nimmt zwar die Wiedererkennungsleistung im Allgemeinen ab, aber der Positiv-Bias bleibt bestehen. Bei der Depression dagegen werden negative emotionale Stimuli favorisiert, was zu dysfunktionellen Verhaltensweisen und zur sozialen Isolation der Patienten beiträgt. Eine Früherkennung und Behandlung der Depression kann helfen die schwerwiegenden Folgen der kognitiven Störungen zu verhindern.
A thermodynamic model for estimating sea and lake ice thickness with optical satellite data
Authors: Wang Xuanji , Key Jeffrey R. , Liu Yinghui
Published: December 2010

Sea ice is a very important indicator and an effective modulator of regional and global climate change. Current remote sensing techniques provide an unprecedented opportunity to monitor the cryosphere routinely with relatively high spatial and temporal resolutions. In this paper, we introduce a thermodynamic model to estimate sea and lake ice thickness with optical (visible, near‐infrared, and infrared) satellite data. Comparisons of nighttime ice thickness retrievals to ice thickness measurements from upward looking submarine sonar show that this thermodynamic model is capable of retrieving ice thickness up to 2.8 m. The mean absolute error is 0.18 m for samples with a mean ice thickness of 1.62 m, i.e., an 11% mean absolute error. Comparisons with in situ Canadian stations and moored upward looking sonar measurements show similar results. Sensitivity studies indicate that the largest errors come from uncertainties in surface albedo and downward solar radiation flux estimates from satellite data, followed by uncertainties in snow depth and cloud fractional coverage. Due to the relatively large uncertainties in current satellite retrievals of surface albedo and surface downward shortwave radiation flux, the current model is not recommended for use with daytime data. For nighttime data, the model is capable of resolving regional and seasonal variations in ice thickness and is useful for climatological analysis.
Space‐time structure of long ocean swell fields
Authors: Delpey Matthias T. , Ardhuin Fabrice , Collard Fabrice , Chapron Bertrand
Published: December 2010

The space‐time structure of long‐period ocean swell fields is investigated, with particular attention given to features in the direction orthogonal to the propagation direction. This study combines space‐borne synthetic aperture radar (SAR) data with numerical model hindcasts and time series recorded by in situ instruments. In each data set the swell field is defined by a common storm source. The correlation of swell height time series is very high along a single great circle path with a time shift given by the deep water dispersion relation of the dominant swells. This correlation is also high for locations situated on different great circles in entire ocean basins. Given the Earth radiusR, we define the distance from the sourceRαand the transversal angleβso thatαandβwould be equal the colatitude and longitude for a storm centered on the North Pole. Outside of land influence, the swell height field at timet,Hss(α,β,t) is well approximated by a functionHss,0(t ‐ Rα/Cg)/times another functionr2(β), whereCgis a representative group speed. Herer2(β) derived from SAR data is very broad, with a width at half the maximum that is larger than 70°, and varies significantly from storm to storm. Land shadows introduce further modifications so that in generalr2is a function ofβandα. This separation of variables and the smoothness of theHssfield, allows the estimation of the full field ofHssfrom sparse measurements, such as wave mode SAR data, combined with one time series, such as that provided by a single buoy. A first crude estimation of a syntheticHssfield based on this principle already shows that swell hindcasts and forecasts can be improved by assimilating such synthetic observations.
Impact of nonlinear energy transfer on the wave field in Pacific hindcast experiments
Authors: Tamura Hitoshi , Waseda Takuji , Miyazawa Yasumasa
Published: December 2010

We investigated the impact of nonlinear energy transfer (Snl) on wave fields by performing hindcast experiments for the Pacific Ocean. Specifically, we evaluated model performance using SRIAM, which was developed to accurately reproduce Snl with lower computational cost than more rigorous algorithms. The model results were compared to in situ wave parameters as well as results from another model employing the widely used discrete interaction approximation method (DIA). Comparison of the model results with buoy observations revealed a negligible difference between SRIAM and DIA for significant wave heights. However, the difference for the peak period was quite pronounced, especially around the tropical Pacific, where a persistent bias in peak frequency was improved by using SRIAM. This study also highlights the impact of source terms on spectral shape under a realistic model setting. Detailed analysis of spectral shape indicated that SRIAM can quantitatively capture the overshoot phenomena around the spectral peak during wave growth. In addition, Snl played a major role in maintaining the equilibrium range; it reacted to changes in the net external sources to cancel out the total source term. These results show that the magnitude of high‐frequency dissipation controls the spectral tail exponent and that the balanced net external source is responsible for the reproduction of the f−4 power law behavior in the equilibrium range.
Plot‐ and watershed‐scale soil moisture variability in a humid Piedmont watershed
Authors: Tague C. , Band L. , Kenworthy S. , Tenebaum D.
Published: December 2010

We investigate space‐time dynamics of soil water through extreme drought and wet periods for a Mid‐Atlantic Piedmont catchment. Soil moisture is a nonlinear control of soil nitrogen cycling processes, providing “hot spot” and “hot moment” dynamics that are not well modeled using time‐ or space‐averaged conditions. We document spatial variation in near‐surface soil moisture and examine relationships between mean and variance in soil moisture at plot and watershed scales. Riparian plot soil moisture spatial variance was significantly higher than the variance in uplands and was high relative to soil moisture variance reported by other studies. Plot soil moisture means closely followed a linear trend with the topographic wetness index. However, high within‐plot variance obscured this relationship for experiments where smaller subsets of samples were used, emphasizing the importance of replicate plot measurements to account for fine‐scale heterogeneity in soil moisture. We demonstrate the importance of these spatial‐temporal patterns of soil moisture for estimates of hydrologic controls on biogeochemical cycling by showing that undersampling of fine‐scale soil moisture variation is likely to lead to overestimation and underestimation of nitrification and denitrification, respectively.
Samoan hot spot track on a “hot spot highway”: Implications for mantle plumes and a deep Samoan mantle source
Authors: Jackson Matthew G. , Hart Stanley R. , Konter Jasper G. , Koppers Anthony A. P. , Staudigel Hubert , Kurz Mark D. , Blusztajn Jerzy , Sinton John M.
Published: December 2010

We report new geochemical data for submarine lavas from the Samoan region that greatly enhance the geochemical data set for volcanoes from the hot spot. Additionally, two volcanoes dredged in the northern Lau Basin, Futuna Island and Manatu seamount, are young (<5 Ma), appear to be genetically related, and may have been generated by melting a component of Samoan mantle that has been advected into the region. We also find evidence for three seamounts and one atoll along the Samoan hot spot track that are not geochemically related to Samoa. We use a plate motion model to show that three non‐Samoan hot spots, currently active in the Cook‐Austral Islands, provided volcanism to the Pacific Plate now in the Samoan region approximately 10–40 Ma. The four interloping volcanoes in the Samoan region exhibit geochemical affinities with the three hot spots. All three hot spots would have left a depleted, viscous, refractory keel that is coupled to the base of the Pacific lithosphere that has been “rafted” to the Samoan region. Therefore, the new data also have implications for the origin of the Samoan hot spot as its origin has been suggested to be a result of either a deep‐seated mantle plume or a consequence of lithospheric cracking. Without major modification of the current “propagating lithospheric cracks” model, it is not clear how such cracks could yield melts from the refractory keel present under the Samoan lithosphere. Instead, a region of buoyantly upwelling mantle, or plume, is suggested to generate the shield stage volcanism in the Samoan region.
In situ stress state in the Nankai accretionary wedge estimated from borehole wall failures
Authors: Chang Chandong , McNeill Lisa C. , Moore J. Casey , Lin Weiren , Conin Marianne , Yamada Yasuhiro
Published: December 2010

We constrain the orientations and magnitudes of in situ stress tensors using borehole wall failures (borehole breakouts and drilling‐induced tensile fractures) detected in four vertical boreholes (C0002, C0001, C0004, and C0006 from NW to SE) drilled in the Nankai accretionary wedge. The directions of the maximum horizontal principal stress (SHmax), indicated by the azimuths of borehole wall failures, are consistent in individual holes, but those in C0002 (margin‐parallel SHmax) are nearly perpendicular to those in all other holes (margin‐normal SHmax). Constrained stress magnitudes in C0001 and C0002, using logged breakout widths combined with empirical rock strength derived from sonic velocity, as well as the presence of the drilling‐induced tensile fractures, suggest that the stress state in the shallow portion of the wedge (fore‐arc basin and slope sediment formations) is predominantly in favor of normal faulting and that the stress state in the deeper accretionary prism is in favor of probable strike‐slip faulting or possible reverse faulting. Thus, the stress regime appears to be divided with depth by the major geological boundaries such as unconformities or thrust faults. The margin‐perpendicular tectonic stress components in the two adjacent sites, C0001 and C0002, are different, suggesting that tectonic force driven by the plate pushing of the Philippine Sea plate does not uniformly propagate. Rather, the stress field is inferred to be influenced by additional factors such as local deformation caused by gravitation‐driven extension in the fore arc and thrusting and bending within individual geologic domains.
Role of depleted flux tubes in steady magnetospheric convection: Results of RCM‐E simulations
Authors: Yang J. , Toffoletto F. R. , Song Y.
Published: December 2010

We present results of a simulation of an idealized steady magnetospheric convection (SMC) event during steady southward IMF BZ using a version of the Rice Convection Model that is coupled to an equilibrium magnetic field solver (RCM‐E) and compare that to a simulation of a substorm growth phase. In contrast to the 1‐hour growth phase, the 5‐hour SMC event is modeled by placing a plasma distribution with substantially depleted entropy parameter PV5/3 on the RCM's high‐latitude boundary. We find that the modeled large‐scale configuration on the nightside during the SMC event differs significantly from the growth phase simulation. First, in the magnetotail tailward of X ≈ −10 RE, the magnetic field is dipole‐like associated with thick plasma sheet. Second, near geosynchronous orbit, the magnetic field is more stretched associated with the strongly enhanced partial ring current and the inner edge of the plasma sheet moves well inside geosynchronous orbit. Third, the electric field shows strong shielding or even overshielding during the SMC; while a penetration electric field emerges in the growth phase simulation. Fourth, the ground magnetogram calculation shows large horizontal magnetic field disturbances in a much thicker auroral zone which is mainly attributed to Hall currents. Meantime, fairly negative magnetic disturbance emerges in the mid and low latitudes which is mainly attributed to the partial ring current approximately extended to terminators. Contrary to previous studies, our simulation does not produce a deep BZ minimum during strong magnetospheric convection, which implies that the pressure balance inconsistency may be dramatically alleviated if the inner magnetosphere is continuously fed with under‐populated flux tubes. We also suggest that strong magnetic field without BZ minimum in the plasma sheet may explain why SMCs can last for hours without a substorm expansion since certain instabilities may not build up to threshold in such a configuration.
Using multispectral optical observations to identify the acceleration mechanism responsible for flickering aurora
Authors: Whiter D. K. , Lanchester B. S. , Gustavsson B. , Ivchenko N. , Dahlgren H.
Published: December 2010

We present an analysis of flickering (2–10 Hz) auroras observed with a state‐of‐the‐art multispectral imaging system, Auroral Structure and Kinetics, located in Tromsø, Norway. Short (1–2 s) periods of flickering aurora have been identified in which the frequency of the brightness oscillations decreases or increases smoothly over time. To the authors' knowledge this is the first detailed analysis of such “chirps” in flickering aurora or field‐aligned bursts. We have found that the electron precipitation energy is strongly anticorrelated with the flickering frequency during all identified chirps. This result is consistent with the theory that flickering aurora is caused by the resonance interaction between electromagnetic ion cyclotron waves and precipitating electrons and that the wave parallel phase velocity is the primary factor determining the electron acceleration produced by this mechanism. Other current theories known to the authors cannot completely explain our observations.
Soil CO2 emissions at Furnas volcano, São Miguel Island, Azores archipelago: Volcano monitoring perspectives, geomorphologic studies, and land use planning application
Authors: Viveiros Fátima , Cardellini Carlo , Ferreira Teresa , Caliro Stefano , Chiodini Giovanni , Silva Catarina
Published: December 2010

Carbon dioxide (CO2) diffuse degassing structures (DDS) at Furnas volcano (São Miguel Island, Azores) are mostly associated with the main fumarolic fields, evidence that CO2 soil degassing is the surface expression of rising steam from the hydrothermal system. Locations with anomalous CO2 flux are mainly controlled by tectonic structures oriented WNW–ESE and NW–SE and by the geomorphology of the volcano, as evidenced by several DDS located in depressed areas associated with crater margins. Hydrothermal soil CO2 emissions in Furnas volcano are estimated to be ∼968 t d−1. Discrimination between biogenic and hydrothermal CO2 was determined using a statistical approach and the carbon isotope composition of the CO2 efflux. Different sampling densities were used to evaluate uncertainty in the estimation of the total CO2 flux and showed that a low density of points may not be adequate to quantify soil emanations from a relatively small DDS. Thermal energy release associated with diffuse degassing at Furnas caldera is about 118 MW (from an area of ∼4.8 km2) based on the H2O/CO2 ratio in fumarolic gas. The DDS also affect Furnas and Ribeira Quente villages, which are located inside the caldera and in the south flank of the volcano, respectively. At these sites, 58% and 98% of the houses are built over hydrothermal CO2 emanations, and the populations are at risk due to potential high concentrations of CO2 accumulating inside the dwellings.
Evaluation of earthquake triggering during the 2005–2008 earthquake sequence on Qeshm Island, Iran
Authors: Lohman R. B. , Barnhart W. D.
Published: December 2010

Coseismic static Coulomb stress changes may either advance or retard the timing of subsequent earthquakes on nearby faults in a manner that depends both on the relative orientations of faults within the vicinity of the primary rupture, as well as on the postseismic redistribution of stress. Here we examine interferometric synthetic aperture radar (InSAR) data spanning two earthquakes that occurred in close temporal and spatial proximity on Qeshm Island in southern Iran. Remote observations of earthquakes such as ground deformation or seismic waves allow us to infer earthquake source parameters, but in general, a nonunique family of solutions is consistent with the data, given our understanding of data noise and the limitations of our ability to model the real Earth. Here, we explore methods for assessing and propagating InSAR noise through our entire analysis of the stress triggering potential between these two earthquakes. We generate a range of source models for each earthquake based both on InSAR and seismic observations and assess whether the expected static Coulomb stress change during the first earthquake is likely to have brought the second event closer to or further from failure. Some combinations support the hypothesis that the first earthquake brought the second fault closer to failure, whereas some do not. Fault plane geometries that agree with InSAR constraints are more likely to suggest that the first earthquake increased the likelihood of the second earthquake, those based on the Harvard and global centroid moment tensor tend to not support triggering between the two events.
Effect of the initial spectrum on the spatial evolution of statistics of unidirectional nonlinear random waves
Authors: Shemer Lev , Sergeeva Anna , Liberzon Dan
Published: December 2010

Results of extensive experiments on propagation of unidirectional nonlinear random waves in a large wave tank are presented. The nonlinearity of the wavefield determined by the characteristic wave amplitude and the dominant wave length was retained constant in various series of experimental runs. In each experimental series, initial spectra of different shape and/or width were considered. Every series contained sufficient number of independent realizations to ensure reliable statistics. Evolution of various statistical parameters along the tank was investigated. It is demonstrated that the spectrum width plays an important role in the evolution of the random wavefield and strongly affects the variation of the wave spectrum as well as of parameters that characterize the deviation of the wavefield statistics from that corresponding to the Gaussian distribution. In particular, in a random wavefield that initially contains independent free harmonics within a narrow spectrum, extremely steep waves appear more often in the process of evolutions than predicted by a Rayleigh distribution, while for wider initial wave spectra the probability of those waves decreases sharply and is well below the Rayleigh values.
Local stratification control of marine productivity in the subtropical North Pacific
Authors: Dave Apurva C. , Lozier M. Susan
Published: December 2010

Strengthened stratification of the upper ocean due to global warming is generally expected to inhibit marine primary productivity in the subtropics, based on the supposition that increased water column stability will decrease vertical mixing and consequently the entrainment of deep nutrients into the euphotic zone. A recent analysis of observational data from the subtropical North Atlantic, however, demonstrates that productivity in this region is not correlated with stratification on interannual time scales over the modern observational record, but is instead impacted by other dynamics that affect vertical mixing and nutrient supply. Herein, we examine data from the Hawaiian Ocean Time series program's Station ALOHA (A Long‐Term Oligotrophic Habitat Assessment) in the subtropical North Pacific. We find that stratification and productivity are not strongly correlated at this location over the observational record. In contrast to the North Atlantic, the weakness of correlation observed at ALOHA may reflect the strongly stratified ecosystem of the eastern subtropical North Pacific and a lack of sufficiently strong interannual forcing in this region. Although basin‐wide climate processes (namely El Niño–Southern Oscillation and Pacific Decadel Oscillation) have previously been suggested to impact local stratification and vertical nutrient supply at ALOHA, we find no evidence of a strong or consistent linkage. Comparing local ecosystem variability to the recently identified North Pacific Gyre Oscillation, however, we observe a correlation with local subsurface productivity and salinity. The correlations have similar structure in both space (i.e., depth) and time and are possibly linked to dynamics associated with the formation and advection of water masses in the central gyre.
Ensemble forecast of analyses: Coupling data assimilation and sequential aggregation
Authors: Mallet Vivien
Published: December 2010

Sequential aggregation is an ensemble forecasting approach that weights each ensemble member based on past observations and past forecasts. This approach has several limitations: The weights are computed only at the locations and for the variables that are observed, and the observational errors are typically not accounted for. This paper introduces a way to address these limitations by coupling sequential aggregation and data assimilation. The leading idea of the proposed approach is to have the aggregation procedure forecast the forthcoming analyses, produced by a data assimilation method, instead of forecasting the observations. The approach is therefore referred to as ensemble forecasting of analyses. The analyses, which are supposed to be the best a posteriori knowledge of the model's state, adequately take into account the observational errors and they are naturally multivariable and distributed in space. The aggregation algorithm theoretically guarantees that, in the long run and for any component of the model's state, the ensemble forecasts approximate the analyses at least as well as the best constant (in time) linear combination of the ensemble members. In this sense, the ensemble forecasts of the analyses optimally exploit the information contained in the ensemble. The method is tested for ground‐level ozone forecasting, over Europe during the full year 2001, with a 20‐member ensemble. In this application, the method proves to perform well with 28% reduction in root‐mean‐square error compared to a reference simulation, to be robust in time and space, and to reproduce many spatial patterns found in the analyses only.
Multi‐instrumental observations of a positive gigantic jet produced by a winter thunderstorm in Europe
Authors: van der Velde Oscar A. , Bór József , Li Jingbo , Cummer Steven A. , Arnone Enrico , Zanotti Ferruccio , Füllekrug Martin , Haldoupis Christos , NaitAmor Samir , Farges Thomas
Published: December 2010

At 2336:56 UTC on 12 December 2009, a bright gigantic jet (GJ) was recorded by an observer in Italy. Forty‐nine additional sprites, elves, halos and two cases of upward lightning were observed that night. The location of the GJ corresponded to a distinct cloud top (−34°C) west of Ajaccio, Corsica. The GJ reached approximately 91 km altitude, with a “trailing jet” reaching 49–59 km, matching with earlier reported GJs. The duration was short at 120–160 ms. This is the first documented GJ which emerged from a maritime winter thunderstorm only 6.5 km tall, showing high cloud tops are not required for initiation of GJs. In the presence of strong vertical wind shear, the meteorological situation was different from typical outbreaks of fall and winter thunderstorms in the Mediterranean. During the trailing jet phase of the GJ, a sprite with halo triggered by a nearby cloud‐to‐ground lightning flash occurred at a relatively low altitude (<72 km). At the same time, the trailing jet and beads were reilluminated. Electromagnetic waveforms from Hungary, Poland, and the USA revealed this GJ is the first reported to transfer negative charge (approximately 136 C) from the ionosphere to the positively charged origins in the cloud (i.e., a positive cloud‐to‐ionosphere discharge, +CI), with a large total charge moment change of 11600 C km and a maximum current of 3.3 kA. Early VLF transmitter amplitude perturbations detected concurrently with the GJ confirm the production of large conductivity changes due to electron density enhancements in the D‐region of the ionosphere.
Ensemble smoother assimilation of hydraulic head and return flow data to estimate hydraulic conductivity distribution
Authors: Bailey R. , Baù D.
Published: December 2010

Numerical groundwater models, frequently used to enhance understanding of the hydrologic and chemical processes in local or regional aquifers, are often hindered by an incomplete representation of the parameters which characterize these processes. In this study, we present the use of a data assimilation algorithm that incorporates all past model results and data measurements, an ensemble smoother (ES) to provide enhanced estimates of aquifer hydraulic conductivity (K) through assimilation of hydraulic head (H) and groundwater return flow volume (RFV) measurements into groundwater model simulation results. On the basis of the Kalman filter methodology, residuals between forecasted model results and measurements, together with covariances between model results at measurement locations and nonmeasurement locations, are used to correct model results. Parameter estimation is achieved by incorporating model parameters into the algorithm, thus allowing the correlation between H, RFV, and K to correct the K fields. The applicability of the ES is demonstrated using a synthetic two‐dimensional transient groundwater modeling simulation. Sensitivity analyses are carried out to show the performance of the ES in regard to measurement error, number of measurements, number of assimilation times, correlation length of the K fields, and the number of stream gage locations. Results show that the departure of the K fields from a reference K field is greatly reduced through data assimilation and demonstrate that the ES scheme is a promising alternative to other inverse modeling techniques because of low computational burden and the ability to run the algorithm entirely independent of the groundwater model simulation.
Intra-Arterial Injection of Neural Stem Cells using a Microneedle Technique does not Cause Microembolic Strokes
Authors: Chua Joshua Y , Pendharkar Arjun V , Wang Nancy , Choi Raymond , Andres Robert H , Gaeta Xavier , Zhang Jian , Moseley Mike E , Guzman Raphael
Published: December 2010

Intra-arterial (IA) injection represents an experimental avenue for minimally invasive delivery of stem cells to the injured brain. It has however been reported that IA injection of stem cells carries the risk of reduction in cerebral blood flow (CBF) and microstrokes. Here we evaluate the safety of IA neural progenitor cell (NPC) delivery to the brain. Cerebral blood flow of rats was monitored during IA injection of single cell suspensions of NPCs after stroke. Animals received 1×106 NPCs either injected via a microneedle (microneedle group) into the patent common carotid artery (CCA) or via a catheter into the proximally ligated CCA (catheter group). Controls included saline-only injections and cell injections into non-stroked sham animals. Cerebral blood flow in the microneedle group remained at baseline, whereas in the catheter group a persistent (15 minutes) decrease to 78% of baseline occurred ( P < 0.001). In non-stroked controls, NPCs injected via the catheter method resulted in higher levels of Iba-1-positive inflammatory cells ( P = 0.003), higher numbers of degenerating neurons as seen in Fluoro-Jade C staining ( P < 0.0001) and ischemic changes on diffusion weighted imaging. With an appropriate technique, reduction in CBF and microstrokes do not occur with IA transplantation of NPCs.
SCALE-PWI: A Pulse Sequence for Absolute Quantitative Cerebral Perfusion Imaging
Authors: Srour Jessy Mouannes , Shin Wanyong , Shah Saurabh , Sen Anindya , Carroll Timothy J
Published: December 2010

The Bookend technique is a magnetic resonance imaging (MRI) dynamic susceptibility contrast method that provides reliable quantitative measurement of cerebral blood flow (CBF) and cerebral blood volume (CBV). The quantification is patient specific, is derived from a steady-state measurement of CBV, and is obtained from T1 changes in the white matter and the blood pool after contrast agent injection. In the current implementation, the Bookend technique consists of three scanning steps requiring a cumulative scan time of 3minutes 47seconds, a well-trained technologist, and extra time for offline image reconstruction. We present an automation and acceleration of the multiscan Bookend protocol through a self-calibrating pulse sequence, namely Self-Calibrated Epi Perfusion-Weighted Imaging (SCALE-PWI). The SCALE-PWI is a single-shot echo-planar imaging pulse sequence with three modules and a total scan time of under 2minutes. It provides the possibility of performing online, quantitative perfusion image reconstruction, which reduces the latency to obtain quantitative maps. A validation study in healthy volunteers ( N = 19) showed excellent agreement between SCALE-PWI and the conventional Bookend protocol ( P > 0.05 with Student's t-test, r = 0.95/slope = 0.98 for quantitative CBF, and r = 0.91/slope = 0.94 for quantitative CBV). A single MRI pulse sequence for absolute quantification of cerebral perfusion has been developed.
Traumatic Brain Injury in Mice Lacking the K Channel, TREK-1
Authors: Namiranian Khodadad , Brink Christa D , Goodman Jerry Clay , Robertson Claudia S , Bryan Robert M
Published: December 2010

The purpose of this study was to determine whether the potassium channel, TREK-1, was neuroprotective after traumatic brain injury (TBI). Since there are no selective blockers, we used TREK-1 knockout (KO) mice for our study. Wild-type (WT) and TREK-1 KO mice were anesthetized and subjected to controlled-cortical impact injury (deformation of the brain by 1.5 mm by a 3-mm diameter rod traveling at a 3 m/s). Laser Doppler perfusion (LDP) decreased by ∼80% in the injured cortex and remained at that level in both WT and TREK-1 KO mice ( n=10 and 11, respectively). Laser Doppler perfusion decreased by 50% to 60% in cortical areas directly adjacent to the site of injury. There were no statistical differences in LDP between genotype. The contusion volume, determined 15 days after the TBI using hematoxylin and eosin-stained coronal brain sections, was 4.1±0.8 ( n=10) and 5.1±0.5 ( n=11) mm3 for WT and TREK-1 KO, respectively (not significant, P=0.34). Cell counts of viable neurons in the CA1 and CA3 regions of the hippocampus were similar between WT and TREK-1 KO mice ( P=0.51 and 0.84 for CA1 and CA3, respectively). We conclude that TREK-1 expression does not provide brain protection after TBI.
Collateral Circulation in Symptomatic Intracranial Atherosclerosis
Authors: Liebeskind David S , Cotsonis George A , Saver Jeffrey L , Lynn Michael J , Cloft Harry J , Chimowitz Marc I ,   Investigators For the Warfarin—Aspirin Symptomatic Intracranial Disease (WASID)
Published: December 2010

Collateral circulation in intracranial atherosclerosis has never been systematically characterized. We investigated collaterals in a multicenter trial of symptomatic intracranial atherosclerotic disease. Baseline angiography was reviewed for information on collaterals in stenoses of the internal carotid, middle cerebral, vertebral, and basilar arteries. A battery of angiographic scales was utilized to evaluate lesion site, arterial patency, antegrade flow, downstream territorial perfusion, and collateral circulation, blinded to all other data. Collateral circulation was adequately available for analysis in 287/569 (50%) subjects with proximal arterial stenoses ranging from 50% to 99%. Extent of collaterals was absent or none in 69%, slow or minimal in 10%, more rapid, yet incomplete perfusion of territory in 7%, complete but delayed perfusion in 11%, and rapid, complete collateral perfusion in 4%. Extent of collateral flow correlated with percentage of stenosis ( P < 0.0001), with more severe stenoses exhibiting greater compensation via collaterals. Overall, collateral grade increased with diminished antegrade flow across the lesion (thrombolysis in myocardial ischemia) and resultant downstream perfusion (thrombolysis in cerebral infarction) (both P<0.001). Our findings provide the initial detailed description of collaterals across a variety of stenoses, suggesting that collateral perfusion is a pivotal component in pathophysiology of intracranial atherosclerosis and implicating the need for further evaluation in ongoing studies.