bluuebunny/crossref_metadata_2025 huggingface dataset:
Kann man chronische Depression effektiv psychotherapeutisch behandeln?
Authors: Ley Pia , Helbig-Lang Sylvia , Petermann Franz
Published: August 2009

Chronische Depression gilt in der klinischen Praxis als besonders schwer behandelbar. Die Befundlage zu dieser Annahme ist jedoch unbefriedigend. Die wenigen existierenden Effektivitätsstudien zu verschiedenen Formen von Psychotherapie bei chronischen Depressionen (z. B. KVT, IPT, CBASP) zeigen tatsächlich, dass die Wirksamkeit eines rein psychotherapeutischen Vorgehens bei chronischen Depressionen begrenzt zu sein scheint; es gibt jedoch Hinweise auf additive Effekte im Rahmen einer Kombinationsbehandlung mit Psychopharmaka. Welchen spezifischen Nutzen neue oder modifizierte Behandlungsverfahren gegenüber klassischen Behandlungsverfahren haben, ist offen, da bislang keine Studien existieren, die diese Verfahren direkt mit klassischen Behandlungsansätzen vergleichen. Weiterhin offen bleibt, inwieweit die schlechten Behandlungsergebnisse tatsächlich der Chronizität der depressiven Störung geschuldet sind, oder ob andere Faktoren, wie eine hohe Achse-II-Komorbidität, den Ausschlag dafür geben.
Pharmakologische und psychotherapeutische Behandlung der bipolaren Depression
Authors: Sarkar Rahul , Rathgeber Katrin , Bräunig Peter
Published: August 2009

Die bipolare Depression ist lange Zeit übersehen worden bei der Betrachtung der bipolaren affektiven Störung, obgleich sie ungleich häufiger ist als die Hypomanie oder die Manie. Dieser Artikel soll einen spezifischen Blick auf die bipolare Depression werfen. Nachdem einleitend die Kennzeichen der bipolaren Depression beschrieben werden, folgen im Hauptteil des Artikels die Darstellung der pharmakologischen sowie der psychotherapeutischen Behandlungsstrategien. Zur besseren Darstellung der spezifischen Ansätze zur Behandlung bipolarer Depression werden bei zentralen Punkten Gegenüberstellungen mit der Behandlung unipolarer Depression sowie mit der Behandlung von manischen Phasen vorgenommen. Die Darstellung von alternativen Therapieverfahren sowie ein Verweis auf vorliegende Leitlinien schließen den Beitrag ab.
Praktische Erfahrungen mit dem Cognitive Behavioral Analysis System of Psychotherapy (CBASP)
Authors: Wambach Katrin , Rief Winfried
Published: August 2009

Schätzungsweise 30 % der Depressionen im klinischen Setting verlaufen chronisch und gehen mit erheblichen Beeinträchtigungen, hohen Gesundheitskosten und immensem Leidensdruck einher. Bisherige pharmakologische und psychotherapeutische Behandlungsansätze sind bei dieser Patientengruppe weniger effektiv als bei akuten depressiven Episoden. Mit dem Cognitive Behavioral Analysis System of Psychotherapy (CBASP) von James McCullough wurde ein spezifisch auf chronische Depression zugeschnittenes Psychotherapieverfahren entwickelt, das behaviorale, kognitive und interpersonelle Therapiestrategien integriert. Die Wirksamkeit von CBASP wurde in einer großen randomisierten kontrollierten Studie belegt ( Keller et al., 2000 ). Der vorliegende Beitrag hat zum Ziel, die praktische Umsetzung von CBASP an einem Fallbeispiel aus einer psychotherapeutischen Ambulanz darzustellen. Dazu wird zunächst ein kurzer Überblick über das Vorgehen innerhalb von CBASP gegeben. Es handelt sich um die Behandlung einer 55-jährigen Büroangestellten, die seit neun Jahren an einer chronischen Major Depression (DSM-IV 296.31) leidet. In ihrem Fall hat sich CBASP als sehr wirksam und hilfreich erwiesen. Dieser Therapieansatz zeigte sich hierbei innerhalb der psychotherapeutischen Praxis gut umsetzbar und erscheint für Fälle mit chronischer Depression außerordentlich geeignet.
Kinderpsychiatrie und Klinische Kinderpsychologie im Dialog
Authors: Helmsen Johanna , Lehmkuhl Gerd , Petermann Franz
Published: August 2009

In den vergangenen Jahren haben sich die Kinderpsychiatrie und Klinische Kinderpsychologie beträchtlich angenähert. Im vorliegenden Beitrag wird untersucht, in welchen Themenbereichen diese inhaltliche Nähe in besonderem Maße besteht. Zudem werden die Forschungstrends im Bereich der Diagnostik und Behandlung psychisch kranker Kinder im deutschen Sprachraum aufgezeigt. Dazu wurden die Jahrgänge 2007 und 2008 der Kindheit und Entwicklung und der Zeitschrift für Kinder- und Jugendpsychiatrie und Psychotherapie einer bibliometrischen Analyse unterzogen. Inhaltlich ließen sich fünf Themenbereiche ausmachen, denen sich gleichzeitig die Klinische Kinderpsychologie und Kinderpsychiatrie gewidmet haben: a) Klinische Kinderneuropsychologie, b) Psychische Störungen des Kindesalters, c) Frühe Kindheit, d) Intelligenzdiagnostik und e) Psychotherapieforschung. Die Ergebnisse verdeutlichen die engen Verbindungen zwischen der Kinderpsychiatrie und der Klinischen Kinderpsychologie. Darüber hinaus lassen sie den Schluss zu, dass Forscher und Praktiker beider Disziplinen von einer interdisziplinären Zusammenarbeit profitieren können. Zukünftig sollte der bereits bestehende Dialog sowohl in der Forschung als auch in der Praxis weiter intensiviert werden, um psychisch kranke Kinder optimal diagnostizieren und behandeln zu können.
Chronische muskuloskelettale Schmerzen in der Schweiz: Die Betreuungsqualität aus Sicht der Ärzte und der Patienten
Authors: Michel  , Tschumi  , Woolf  , Zeidler  , Beglinger  , Dalvit  , Felder  , Graf  , Steurer
Published: August 2009

Ein hoher Prozentsatz der Bevölkerung leidet an chronischen muskulo-skelettalen Schmerzen (CMS) und die Betreuung von Patienten mit CMS scheint nicht optimal zu sein. Ziel der vorliegenden Untersuchungen war die Erhebung und Auswertung der epidemiologischen Daten sowie das Erkennen allfälliger Defizite in der Betreuung. Die Studie erfolgte in mehreren Stufen: Eine europäische Studie mit Einbezug der Schweiz erhob in einem ersten Schritt Daten sowohl bei Patienten mit chronischen muskuloskelettalen Schmerzen wie auch bei behandelnden Ärzten. Diese Resultate wurden in zwei Workshops vertieft diskutiert und weiter ausgearbeitet (Teilnehmer: Ärzte und Patienten). In einem weiteren Schritt wurden die Resultate der Workshops nochmals in einer Umfrage sowohl in der Deutsch- wie der Westschweiz bei Patienten und Ärzten vorgestellt und weiter analysiert. Die Datenerhebung im Rahmen der europäischen Studie ergab erhebliche Defizite: In 35% der Fälle wurde keine Diagnose gestellt, die Lebensqualität ist bei 1⁄3 der Patienten deutlich reduziert, Patienten sind über ihre Erkrankung schlecht informiert und die medikamentöse Behandlung wird oft als inadäquat beurteilt. Die beiden Workshops bestätigten die Resultate und ergaben folgende Schwachpunkte: Die genauen Ursachen der Schmerzen bleiben häufig unklar, es bestehen Kommunikationsprobleme zwischen Patient und Arzt, der Umgang mit der medikamentösen Therapie ist inadäquat und das Zeitmanagement während der Konsultation ist mangelhaft. Schliesslich fand sich in der darauf folgenden Umfrage eine Bestätigung der gefundenen Defizite. In der Betreuung von Patienten mit CMS gibt es erhebliche Defizite, wie fehlende oder unklare Diagnose, mangelhaftes Verständnis der medizinischen Sachverhalte und inadäquate Behandlung. Diese aufgedeckten Mängel sind durchaus veränderbar und erfordern Massnahmen für eine Optimierung der Betreuung von Schmerzkranken.
Hypertrophe Kardiomyopathie und plötzlicher Herztod – ICD-Indikationen in der Grauzone
Authors: Fauchère  , Duru
Published: August 2009

Die hypertrophe Kardiomyopathie ist die häufigste genetisch bedingte kardio­vaskuläre Erkrankung, und der plötzliche Herztod deren am meisten gefürchtete Komplikation und häufigste Todesursache. Seit der Entwicklung implantierbarer kardiovertierender Defibrillatoren mit der Möglichkeit einer wirksamen Prävention des plötzlichen Herztodes ist die Identifikation der Patienten, die von einer solchen Massnahme profitieren, in den Vordergrund der Bemühungen gerückt. Für einen Grossteil der Patienten fehlen aufgrund ihrer klinischen Merkmale klare Richtlinien. Die Indikation zur ICD-Implantation liegt bei ihnen folglich in einem Graubereich. Die Datenlage stammt vorwiegend aus retrospektiven Analysen; randomisierte, prospektiv geführte Studien fehlen weitgehend und sind aus ethischen Gründen und aufgrund der beschränkten Patientenzahl auch zukünftig nicht zu erwarten. Der folgende Artikel will versuchen, die aktuelle Datenlage zusammenzufassen, um die notwendige wissensbasierte Entscheidungsfindung zu ermöglichen.
A statistical study of BRIs (SMCs), isolated substorms, and individual sawtooth injections
Authors: DeJong A. D. , Ridley A. J. , Cai X. , Clauer C. R.
Published: August 2009

There are many similarities and differences in the solar wind drivers during three of the main modes of convection in the magnetosphere (isolated substorms, global sawtooth oscillations, and steady magnetospheric convection (SMC) events, which we term here balanced reconnection intervals (BRI)). Thus, this investigation utilizes statistical analysis to compare the solar wind and interplanetary magnetic field (IMF) drivers and their steadiness (standard deviation divided by the mean) during these three different event types. By including the steadiness of the drivers, the importance of magnitude, sign, and stability of the drivers for the different modes can be investigated. A series of histograms with each mode plotted over top of 6 years of background is used to measure the deviation of the mode drivers from the nominal data, and also allows for a comparison between each event type. We found that the magnitude and direction of Bz are the dominate driver for substorms, while BRIs and sawteeth require both magnitude and steadiness of certain drivers to occur. Both BRIs and sawteeth show similar steadiness in their drivers, while the magnitude of the drivers is much stronger for the sawtooth oscillations. Also included in this study are the substorms that initiate BRIs. The solar wind and IMF drivers for the initiating substorms are similar to drivers for BRIs; thus initiating substorms of BRIs are different from isolated substorms and may play a role in preconditioning the magnetosphere for BRIs.
A new high‐resolution unstructured grid finite volume Arctic Ocean model (AO‐FVCOM): An application for tidal studies
Authors: Chen Changsheng , Gao Guoping , Qi Jianhua , Proshutinsky Andrey , Beardsley Robert C. , Kowalik Zygmunt , Lin Huichan , Cowles Geoffrey
Published: August 2009

A spherical coordinate version of the unstructured grid 3‐D FVCOM (finite volume coastal ocean model) has been applied to the Arctic Ocean to simulate tides with a horizontal resolution ranging from 1 km in the near‐coastal areas to 15 km in the deep ocean. By accurately resolving the irregular coastlines and bathymetry in the Arctic Ocean coastal regions, this model reproduces the diurnal (K1 and O1) and semidiurnal (M2 and S2) tidal wave dynamics and captures the complex tidal structure along the coast, particularly in the narrow straits of the Canadian Archipelago. The simulated tidal parameters (harmonic constituents of sea surface elevation and currents) agree well with the available observational data. High‐resolution meshes over the continental shelf and slope capture the detailed spatial structure of topographic trapped shelf waves, which are quite energetic along the Greenland, Siberia, and Spitsbergen continental slope and shelf break areas. Water stratification influences the vertical distribution of tidal currents but not the water transport and thus tidal elevation. The comparison with previous finite difference models suggests that horizontal resolution and geometric fitting are two prerequisites to simulate realistically the tidal energy flux in the Arctic Ocean, particularly in the Canadian Archipelago.
Organic aerosol formation in urban and industrial plumes near Houston and Dallas, Texas
Authors: Bahreini R. , Ervens B. , Middlebrook A. M. , Warneke C. , de Gouw J. A. , DeCarlo P. F. , Jimenez J. L. , Brock C. A. , Neuman J. A. , Ryerson T. B. , Stark H. , Atlas E. , Brioude J. , Fried A. , Holloway J. S. , Peischl J. , Richter D. , Walega J. , Weibring P. , Wollny A. G. , Fehsenfeld F. C.
Published: August 2009

We present measurements of organic aerosol (OA) in urban plumes from Houston and Dallas/Fort Worth as well as in industrial plumes in the Houston area during TexAQS‐2006. Consistent with the TexAQS‐2000 study, measurements show greater amount of aerosol mass downwind of the industrial centers compared to urban areas. This is likely due to higher emission and processing of volatile organic compounds (VOCs) from the industrial sources along the Houston ship channel. Comparisons of the current measurements with observations from the northeastern (NE) United States indicate that the observed ratios of the enhancement above background in OA, ΔOA, to the enhancement above background in CO, ΔCO, downwind of urban centers of Houston and Dallas/Fort Worth are within a factor of 2 of the same values in plumes from urban areas in the NE United States. In the ship channel plumes, ΔOA/ΔCO exceeds that in the urban areas by factors ranging from 1.5 to 7. We use a chemical box model to simulate secondary organic aerosol (SOA) formation from anthropogenic and biogenic VOCs in different plumes using recently reported dependencies of SOA yields on VOC/NOx ratios. Modeled SOA to CO enhancement ratios are within a factor of 2 of measurements. The increase in SOA from biogenic VOCs (BVOCs) predicted by the chemical box model as well as by a separate analysis using a Lagrangian particle dispersion model (FLEXPART) is <0.7 μg per standard m3 (sm−3). We find no evidence for a substantial influence of BVOCs on OA formation in our measurements in Houston area.
Why do some lightning return stroke models not reproduce the far‐field zero crossing?
Authors: Shoory A. , Rachidi F. , Rubinstein M. , Moini R. , Sadeghi S. H. H.
Published: August 2009

In this paper, we investigate the reasons why some return stroke models do not reproduce one of the characteristic features of the electromagnetic fields radiated by lightning, namely the far‐field inversion of polarity with a zero crossing occurring in the tens of microseconds range. This study leads to physical insights into the behavior of the return stroke attenuation and speed as a function of height. Making reference to the properties of time domain far fields, we show that any one of the existing lightning return stroke channel models, including the electromagnetic models, sometimes known as Antenna Theory models, and the engineering models, should be able to predict a zero crossing in the far field as long as the duration of the return stroke current and the height of the channel are finite. However, the present versions of most of the available engineering and electromagnetic models predict the zero crossing to occur at times that fall well beyond those observed experimentally. We identify three mechanisms responsible for the time of occurrence of the reversal of polarity in the far fields: the current attenuation along the channel, the duration of the return stroke current, and the return stroke speed. The analysis of the MTLE and MTLL engineering models shows that the higher the attenuation of the current along the channel, the earlier the polarity reversal of the vertical electric field. Also, for a given value of the attenuation factor, higher propagation speeds correspond to earlier polarity reversal times. For the TCS model, in which the only adjustable parameter is the return‐stroke speed, we show that the far‐field zero crossing occurs considerably later than the values predicted by both the MTLE and the MTLL models. This is shown to be essentially due to the fact that the decrease of the current wave along the channel according to the TCS model is less pronounced than the current attenuation predicted by the MTLE and MTLL models. Furthermore, it is shown that, in the electromagnetic models, a uniformly distributed resistance along the channel does not lead to a zero crossing in the tens of microseconds range even for large resistance values. This is due to the significant increase of the current pulse duration, as it propagates along the channel as a result of the dispersion effect. The correct zero crossing time, however, can indeed be successfully reproduced if a nonlinear channel resistance is used, which prevents the significant increase of the current pulse duration as it propagates up the channel. Finally, based on the predictions of the MTLE, MTLL, and TCS models, it is shown that the zero crossing time decreases as the observation point moves farther away from the lightning channel, with the amount of variation of less than 10%.
Comparisons of monthly mean 10 m wind speeds from satellites and NWP products over the global ocean
Authors: Wallcraft A. J. , Kara A. B. , Barron C. N. , Metzger E. J. , Pauley R. L. , Bourassa M. A.
Published: August 2009

The accuracy of wind speed at 10 m above the sea surface from two satellite and three numerical weather prediction (NWP) products is investigated over the global ocean. Rain‐free equivalent neutral winds from the Quick Scatterometer (QuikSCAT) are converted to stability‐dependent winds to be consistent with those from NWP products and are taken as truth in comparisons to winds from other products. Quantitative statistical analyses presented at each grid point over the global ocean reveal that monthly winds from NWP products have almost perfect skill relative to those from QuikSCAT winds during the 3‐year common period (September 1999 to August 2002). Exceptions occur in tropical regions and high southern latitudes. Wind speeds adjusted to 10 m at many moored buoys located in different regions of the global ocean further confirm the accuracy of monthly NWP winds, giving RMS difference of 1.0 m s−1 based on 1281 monthlong time series. The satellite‐based QuikSCAT winds agree with buoy winds relatively better than NWP products. While there is good agreement among wind products on monthly timescales, large differences (>3 m s−1 and more) in NWP winds are found in comparison to QuikSCAT winds on shorter time intervals at high latitudes. Daily means of sensible and latent heat fluxes based on NWP winds can therefore differ as much as 100 W m−2 in comparison to those based on QuikSCAT winds. In general, NWP wind‐based sensible and latent heat fluxes are more similar to their QuikSCAT wind‐based counterparts in tropical regions and midlatitudes.
Saturation of curvature‐induced secondary flow, energy losses, and turbulence in sharp open‐channel bends: Laboratory experiments, analysis, and modeling
Authors: Blanckaert K.
Published: August 2009

The paper investigates the influence of relative bend curvature on secondary flow, energy losses, and turbulence in sharp open‐channel bends. These processes are important in natural streams with respect to sediment transport, the bathymetry and planimetry, mixing and spreading of pollutants, heat, oxygen, nutrients and biological species, and the conveyance capacity. Laboratory experiments were carried out in a configuration with rectangular cross section, consisting of a 193° bend of constant radius of curvature, preceded and followed by straight reaches. This somewhat unnatural configuration allows investigating the adaptation of mean flow and turbulence to curvature changes in open‐channel bends, without contamination by other effects such as a mobile bed topography. Experiments were carried out for three different values of the curvature ratio, defined as the ratio of centerline radius of curvature over flow depth, which is the principal curvature parameter for hydrodynamic processes. Commonly used so‐called linear models predict secondary flow to increase linearly with the curvature ratio. The reported experiments show that the secondary flow hardly increases in the investigated very sharp bends when the curvature ratio is further increased. This phenomenon is called saturation. Similar saturation is observed for the energy losses and the turbulence. This paper focuses on the analysis and modeling of the saturation of energy losses and turbulence. Secondary flow is found to be the dominant contribution to the curvature‐induced increase in turbulence production, which leads to increased energy losses. The curvature‐induced turbulence is explained by the fact that the turbulence dissipation lags behind the turbulence production, in agreement with the concept of the turbulence energy cascade. A 1‐D model is proposed for the curvature‐induced energy losses and turbulence. It could extend 1‐D or depth‐averaged 2‐D models that are commonly used in long‐term (scale of a flood event to geological scales) or large‐scale (scale of a river basin) investigations on flood propagation, hazard mapping, water quality modeling, and planimetric river evolution.
Novel approach to geomagnetically induced current forecasts based on remote solar observations
Authors: Pulkkinen A. , Taktakishvili A. , Odstrcil D. , Jacobs W.
Published: August 2009

In this paper, a novel approach that uses remote solar observations to forecast geomagnetically induced currents (GIC) is introduced. The approach utilizes first‐principles‐based propagation of the observed coronal mass ejections in the heliosphere and uses the modeled transient properties at the Earth to make site‐specific statistical estimates of GIC. The approach provides unprecedented forecast lead time of 1–2 days. The approach is validated for two nodes of the North American power transmission system by means of 14 coronal mass ejection events for which GIC observations are available. It is shown that the mean of the absolute value of the error in the GIC event start time prediction is about 5 h while the length of the events is underestimated on average by 17 h. The success rate, i.e., hits versus the total number of events, of the predictions are 12/14 and 7/14 for the two GIC stations, respectively. The implications of the new approach and the accuracy of the approach are discussed and possible avenues for future improvements are outlined.
Interphase mass transfer in variable aperture fractures: Controlling parameters and proposed constitutive relationships
Authors: Detwiler Russell L. , Rajaram Harihar , Glass Robert J.
Published: August 2009

Interphase mass transfer in variable aperture fractures occurs in many problems where two immiscible fluids are present, such as dissolution of dense nonaqueous phase liquids into groundwater, dissolution of CO2 in deep saline aquifers, and evaporation of trapped water by flowing gas during natural gas production. Typically, one fluid is entrapped by capillary forces and resides in immobilized regions whose distribution and geometry are controlled by the relative influence of capillary, gravitational, and viscous forces within the fracture. For the case of fractures bounded by a low porosity/permeability matrix, interphase mass transfer occurs predominantly owing to diffusive/advective transport from the entrapped phase interface into the phase flowing through the fracture. We explore the relative influence of the initial entrapped phase geometry and mean flowing phase velocities on the dissolution of the entrapped phase. Our systematic simulations use a percolation‐based model of phase invasion and depth‐averaged models of flow, transport, and mass transfer. The invasion model provides a physically based distribution of entrapped phase within the fracture and the mass transfer model implicitly calculates interphase mass transfer from discrete regions of entrapped phase without the need for empirical mass transfer relationships. Results demonstrate behavior across a wide range of initial entrapped phase distributions, with entrapped phase saturations ranging from zero to near the percolation threshold. Interfacial area evolves with a near‐linear dependence on entrapped phase saturation during dissolution in each simulation, and fracture‐scale intrinsic mass transfer rate coefficients exhibit a nonlinear dependence on Peclet number and a negligible dependence on entrapped phase saturation. These observations provide a basis for the development of constitutive relationships that quantify interphase mass transfer in variable aperture fractures as a function of entrapped phase saturation and flow rate; coarse‐grid dissolution simulations using these constitutive relationships demonstrate good agreement with results from the high‐resolution mechanistic simulations.
Cost‐effective alternatives for mitigating Cryptosporidium risk in drinking water and enhancing ecosystem services
Authors: Bryan B. A. , Kandulu J. M.
Published: August 2009

Under the multibarrier paradigm, water quality management barriers that mitigate risk to consumers are required at multiple points from the catchment to the tap. We present a cost‐effectiveness analysis of 13 catchment‐ and treatment‐based management alternatives for mitigating Cryptosporidium risk in the Myponga water supply catchment, South Australia. A broad range of costs and benefits are identified and valued, including setup, operation and maintenance, and opportunity costs, and benefits for ecosystem services including water quality, biodiversity, carbon sequestration, and farm production services. The results suggest that the cost‐effectiveness of investment in water quality management can be substantially enhanced by considering the costs of management and the benefits for ecosystem services, in addition to Cryptosporidium removal effectiveness. Cost‐effectiveness of investment in management alternatives is dependent upon the desired level of Cryptosporidium removal effectiveness by both the catchment and treatment barriers. The combination of a spatially targeted 25% restriction in water course access of nondairy cattle and treatment by enhanced coagulation provides the most (net) cost‐effective Cryptosporidium risk mitigation strategy. This combination may achieve 0.614 log removal at a net cost of A$0.7 million and (net) cost‐effectiveness of A$1.14 million per log removal. Additional risk mitigation can be achieved through the addition of ultraviolet irradiation treatment, higher levels of water course access restriction for cattle, and the adoption of dung beetles in the catchment. Economic valuation of a range of costs and benefits of management priorities can support cost‐effective water quality management investment decisions and inform elements of policy design such as cost‐sharing arrangements and spatial targeting.
Magma extraction from the mantle wedge at convergent margins through dikes: A parametric sensitivity analysis
Authors: Johnson S. E. , Jin Z.‐H.
Published: August 2009

We address under what conditions a magma generated by partial melting at 100 km depth in the mantle wedge above a subduction zone can reach the crust in dikes before stalling. We also address under what conditions primitive basaltic magma (Mg # > 60) can be delivered from this depth to the crust. We employ linear elastic fracture mechanics with magma solidification theory and perform a parametric sensitivity analysis. All dikes are initiated at a depth of 100 km in the thermal core of the wedge, and the Moho is fixed at 35 km depth. We consider a range of melt solidus temperatures (800–1100°C), viscosities (10–100 Pa s), and densities (2400–2700 kg m−3). We also consider a range of host rock fracture toughness values (50–300 MPa m1/2) and dike lengths (2–5 km) and two thermal structures for the mantle wedge (1260 and 1400°C at 100 km depth and 760 and 900°C at 35 km depth). For the given parameter space, many dikes can reach the Moho in less than a few hundred hours, well within the time constraints provided by U series isotope disequilibria studies. Increasing the temperature in the mantle wedge, or increasing the dike length, allows additional dikes to propagate to the Moho. We conclude that some dikes with vertical lengths near their critical lengths and relatively high solidus temperatures will stall in the mantle before reaching the Moho, and these may be returned by corner flow to depths where they can melt under hydrous conditions. Thus, a chemical signature in arc lavas suggesting partial melting of slab basalts may be partly influenced by these recycled dikes. Alternatively, dikes with lengths well above their critical lengths can easily deliver primitive magmas to the crust, particularly if the mantle wedge is relatively hot. Dike transport remains a viable primary mechanism of magma ascent in convergent tectonic settings, but the potential for less rapid mechanisms making an important contribution increases as the mantle temperature at the Moho approaches the solidus temperature of the magma.
Magnitude estimation for early warning applications using the initial part of P waves: A case study on the 2008 Wenchuan sequence
Authors: Wang Weitao , Ni Sidao , Chen Yong , Kanamori Hiroo
Published: August 2009

A period parameter τc and an amplitude parameter Pd determined from the very beginning of P wave are important for earthquake early warning (EEW), yet their dependence on source mechanism, focal depth and epicentral distance has not been fully studied. After the devastating Mw7.9 Wenchuan earthquake, hundreds of M4‐6 earthquakes occurred with diverse focal mechanisms and depth range of 2–20 km. We calculate τc and Pd of these aftershocks and examine their dependence on magnitude, τc, distance, and depth. We find that τc correlates well with magnitude, but joint regression including distance and depth does not significantly improve the correlation. The effect of focal mechanism on the τc ‐magnitude correlation is not obvious. When P wave is nodal, τc measurement becomes inaccurate. Also, τc is systematically greater for slow earthquakes, leading to a possible false alarm. Thus, more studies are required to discriminate slow earthquakes for robust early warning.
Can aerosol decrease cloud lifetime?
Authors: Small Jennifer D. , Chuang Patrick Y. , Feingold Graham , Jiang Hongli
Published: August 2009

Cloud responses to changes in aerosol remain a dominant uncertainty in the radiative forcing of climate. Two main constructs related to aerosol effects on clouds have been postulated: (i) the “albedo effect” whereby anthropogenic aerosol results in increased droplet concentrations that generate increases in cloud albedo, all else (particularly cloud water) being equal; (ii) the “lifetime effect” whereby anthropogenic aerosol suppresses precipitation and results in clouds with more liquid water, higher fractional cloudiness, and longer lifetimes. Based on new observations presented here, and supported by previous fine‐scale modeling studies, we suggest that the balance of evidence shows that non‐precipitating cumulus clouds can experience an evaporation‐entrainment feedback, and respond to aerosol perturbations in a manner inconsistent with the traditional “lifetime effect.” Because most cumulus clouds evaporate without producing significant precipitation, this is particularly relevant to estimates of aerosol indirect effects on climate.
Elliptical polarization of Saturn Kilometric Radiation observed from high latitudes
Authors: Fischer G. , Cecconi B. , Lamy L. , Ye S.‐Y. , Taubenschuss U. , Macher W. , Zarka P. , Kurth W. S. , Gurnett D. A.
Published: August 2009

The high‐inclination orbits of the Cassini spacecraft from autumn 2006 until spring 2007 allowed the Cassini/RPWS (Radio and Plasma Wave Science) instrument to observe Saturn Kilometric Radiation (SKR) from latitudes up to 60° for the first time. This has revealed a surprising new property of SKR: above ∼30° in observational latitude, a significant amount of SKR is strongly elliptically polarized, in marked contrast to previous observations from low latitudes, which showed only circular polarization. There are transitional latitudes where the elliptical polarization occurs in “patches” in the time‐frequency spectrograms next to regions of still completely circularly polarized SKR. From ∼45° to 60° in northern latitude, it is found that most of the SKR is elliptically polarized throughout its entire frequency range with an average degree of ∼0.7 in linear polarization. We demonstrate the ellipticity of SKR by using the concept of “apparent polarization” in case of two‐antenna measurements, but also show three‐antenna measurements from which the polarization can be unambiguously determined. Possible reasons for the variation of SKR polarization with the observer's latitude will be discussed.
Comparison of wind and tidal contributions to seasonal circulation of the Yellow Sea
Authors: Moon Jae‐Hong , Hirose Naoki , Yoon Jong‐Hwan
Published: August 2009

Seasonal circulation of the Yellow Sea (YS) in response to wind and tidal forces is examined using a three‐dimensional numerical model. Wind forcing affects the wintertime circulation of the YS; on the other hand, the summer southerly monsoon is weak and therefore has little impact on the circulation, on the basis of comparative experiments with and without wind conditions. Results indicate that the Yellow Sea Warm Current (YSWC) along the YS trough exists regardless of wind forcing. However, strong winter northerly winds intensify the southward coastal flows along both coasts of the YS, and therefore, the northward intrusion of the YSWC becomes stronger. These flows in the YS are substantially weakened when wind forcing is not applied to the model. In addition to wind‐driven circulation, tide‐induced circulation is also dominant in the YS, particularly in summer. In winter, the tidal effect weakens the upwind and downwind flows in response to the strong northerly winds, while in summer, tidal forcing induces a strong southward residual flow along the western slope and a cyclonic gyre with a bottom cold water dome at the central region of the YS. The southward residual current possibly explains the southward movement of the Yellow Sea Bottom Cold Water as observed in summer. Comparison to the effects of parameterized tidal mixing suggests that residual flow driven by explicit tidal forcing plays an important role in the summertime circulation of the YS.
Ice nucleation behavior of biomass combustion particles at cirrus temperatures
Authors: DeMott Paul J. , Petters Markus D. , Prenni Anthony J. , Carrico Christian M. , Kreidenweis Sonia M. , Collett Jeffrey L. , Moosmüller Hans
Published: August 2009

Measurements of ice formation by biomass combustion particles generated in controlled laboratory burns were made using a continuous flow diffusion chamber operating in the temperature range between −45 and −60°C. These measurements are the first of their kind to investigate the role that such particles may play in ice formation in upper tropospheric clouds. Measurements of aerosol water uptake were used to examine the role of hygroscopicity in low‐temperature ice nucleation by biomass combustion particles. Ice formation by the smoke particles at below −45°C and below water saturation followed the temperature and relative humidity dependencies predicted for water activity‐based homogeneous freezing within measurement uncertainties. As predicted, relative humidity dependence of homogeneous freezing fractions on hygroscopicity was weak in comparison with the temperature dependence for biomass particles of typical atmospheric sizes. The action of heterogeneous ice nucleation in or on these small smoke particles in the haze particle regime could not be distinguished within measurement uncertainties. Impedance of homogeneous freezing below −50°C was inferred for freezing higher number fractions of predominantly organic smoke particles separately reported to contain an abundance of large organic molecules, consistent with the recently predicted onset conditions for and impact of viscous or glassy aerosol phase states. Finally, we note that precision and accuracy requirements of instrumentation for resolving modest impacts (a few degrees less supercooling or a few percent lower relative humidity) of heterogeneous freezing, as compared with homogeneous freezing in the upper tropospheric temperature regime present difficulties for validating aerosol impacts on cirrus.
Targeted Overexpression of Endothelin-1 in Astrocytes Leads to More Severe Cytotoxic Brain Edema and Higher Mortality
Authors: Yeung Patrick Ka Kit , Lo Amy Cheuk Yin , Leung Justin Wai Chung , Chung Stephen Sum Man , Chung Sookja Kim
Published: August 2009

Transgenic mice overexpressing endothelin-1 (ET-1) in astrocytes (GET-1) displayed more severe brain edema and neurologic dysfunction after experimental ischemic stroke. However, it was not clear whether astrocytic ET-1 contributed to cytotoxic or vasogenic edema associated with stroke. In this study, the role of astrocytic ET-1 in cytotoxic edema and brain injury was investigated. Upon acute water intoxication, the GET-1 mice had a lower survival rate and more severe neurologic deficits. Such an exacerbated condition in the GET-1 mice may be a result of a significant increase in cerebral water content and increased expression of the water channel protein, aquaporin 4 (AQP-4). The GET-1 mice treated with OPC-31260, a nonpeptide arginine vasopressin V2 receptor antagonist, were alleviated from the cerebral water accumulation and neurologic deficit during the early time period after water intoxication. In addition, a significant reduction of AQP-4 expression was observed in astrocytic end-feet AQP-4 in the hippocampus of the GET-1 mice treated with OPC-31260. Therefore, ET-1-induced AQP-4 expression and cerebral water accumulation are the key factors in brain edema associated with acute water intoxication. The V2 receptor antagonist, OPC-31260, may be one of the effective drugs for the early treatment of ET-1-induced cytotoxic edema and brain injury.
Results of a Wildlife Toxicology Workshop held by Smithsonian Institution: Identification & Prioritization of Problem Statements
Authors: Grim K. Christiana , Jankowski Mark , Aguirre Alonso , Beasley Val , Fairbrother Anne , Gerould Sarah , Rattner Barnett , Rowles Teri , Monfort Steve , Tan Shirlee
Published: August 2009

Background/Question/Methods

On March 13-15, 2007 nearly 50 scientists and administrators from the US and Canada participated in a Smithsonian-sponsored Wildlife Toxicology Workshop. Invitees were from academic, government, conservation and private organizations and were selected to represent the diverse disciplines that encompass wildlife toxicology. The workshop addressed scientific and policy issues, strengths and weaknesses of current research strategies, interdisciplinary and science-based approaches in the study of complex contaminant issues, mechanisms for disseminating data to policy-makers, and the development of a partner network to meet the challenges facing wildlife toxicology over the next decade. Prior to the meeting, participants were asked to submit issues deemed to be of highest concern which shaped four thematic groups for discussion: Wildlife Toxicology in Education, Risk Assessment, Multiple Stressors/Complex Mixtures, and Sub-Lethal and Population-Level Effects.

Results/Conclusions

From these discussion groups, 18 problem statements were developed and prioritized outlining the most important issues to address now and into the future. Along with each problem statement participants developed potential solutions and action steps geared to move each issue forward. The workshop served as a stepping-stone for action in the field of wildlife toxicology. These problem statements and the resulting action items are presented to the inter-disciplinary wildlife toxicology community for adoption, and future work and action items in these areas are encouraged. For example, it was found that ecologists would be essential in addressing the implications of sublethal or lethal effects of contaminants on wildlife at the population, community and ecosystem scales. The workshop outcome looks to generate conversation and collaboration that will lead to the development of innovative research, future mechanisms for funding, workshops, working groups, and listserves within the wildlife toxicology community.
Cutting the trees to save the forest: The Finch Pruyn working forest
Authors: Neugarten Rachel , Wolf Steven , Stedman Rich
Published: August 2009

The past two decades have seen sales of millions of acres of commercial forest land in the United States. Changed ownership often results in altered forest management, parcelization or development. Such changes have profound implications for forest species and ecosystems, as well as the timber industry, recreational opportunities, and local and regional economies. An emerging strategy seeks to protect lands through complex public-private partnerships involving state agencies, conservation organizations, and commercial investors. By definition, these partnerships have both environmental and socioeconomic goals; as such, they represent contemporary experiments in sustainable development applied to forested landscapes. As this approach is a recent innovation, its benefits for nature and people have yet to be demonstrated, and the general applicability of this integrated approach to conservation is unknown. Our objective is to identify context-specific objectives and indicators to support integrated monitoring and adaptive management for the former Finch Pruyn lands, which encompass 161,000 acres in the Adirondack region of New York State. This interdisciplinary project involves social science faculty and students from Cornell University and cooperation from conservation scientists from The Nature Conservancy. Through a review of the literature on criteria and indicators for sustainable forestry, we developed an analytical framework for measuring ecological, social, and economic implications of forest management practices. Through key informant interviews, we identified context-specific objectives and indicators for the Finch Pruyn lands, including forest health, species protection, expanded recreation opportunities and community economic vitality. Our approach allows us to compare existing commitments to collection of monitoring data to ideal data sets as defined by actors occupying various structural positions. Identification of potential gaps in monitoring represents an opportunity for dialogue, reallocation of resources and enrollment of new strategic partners. Over time, these global and local indicators can support an adaptive framework through which flows of information inform management in an iterative process. Preliminary results indicate that this project entails several innovations that may contribute to its success, including the development of a comprehensive ecological baseline and the explicit engagement of local claims to livelihoods and access. We make several recommendations for future working forest agreements, such as the need to define clear environmental and socioeconomic goals at the outset, and, when private philanthropy is central to project viability, the incorporation of monitoring costs into initial fundraising targets. We believe these lessons are applicable to conservation development projects in the Northern Forest region and beyond.
Defects in virgin hydrothermally grown n-type ZnO studied by temperature dependent Hall effect measurements
Authors: Schifano R. , Monakhov E. V. , Vines L. , Svensson B. G. , Mtangi W. , Auret F. D.
Published: August 2009

Temperature dependent Hall (TDH) effect measurements have been performed on three virgin and hydrothermally grown ZnO samples with resistivities between ∼5 and ∼200 Ω cm at room temperature. The electrical conduction observed experimentally in the temperature range of 330–70 K can be accurately described by three donor levels with positions 41–48, 60–66, and ∼300 meV below the conduction band edge (EC) and an acceptor level in the lower part of the energy band gap (EG). Correlation of the TDH data with results from secondary ion mass spectrometry and admittance spectroscopy on the same samples suggests a rather firm association of the intermediate donor level with complexes involving Al impurities, while the shallowest one is tentatively ascribed to H-related centers. A large fraction of the deep donor remains nonionized in the temperature range studied and contributes substantially to the neutral-impurity-scattering of the conducting electrons. A detailed analysis of the TDH data, using the relaxation time approximation, reveals, however, that ionized-impurity-scattering and optical phonon scattering are the main mechanisms limiting the electron mobility which exhibits a maximum value of ∼125 cm2/V s at ∼200 K. The major reason for this modest value is the high concentration of compensating acceptors in the lower part of EG reaching values of ∼3×1017 cm−3 and where Li plays an important role. However, the Li content is not sufficient to account for all the acceptors and additional impurities, excluding group I elements, and/or intrinsic defects have to be considered.
Gyrokinetic water-bag modeling of a plasma column: Magnetic moment distribution and finite Larmor radius effects
Authors: Klein R. , Gravier E. , Morel P. , Besse N. , Bertrand P.
Published: August 2009

Describing turbulent transport in fusion plasmas is a major concern in magnetic confinement fusion. It is now widely known that kinetic and fluid descriptions can lead to significantly different properties. Although more accurate, the kinetic calculation of turbulent transport is much more demanding of computer resources than fluid simulations. An alternative approach is based on a water-bag representation of the distribution function that is not an approximation but rather a special class of initial conditions, allowing one to reduce the full kinetic Vlasov equation into a set of hydrodynamics equations while keeping its kinetic character [P. Morel, E. Gravier, N. Besse et al., Phys. Plasmas 14, 112109 (2007)]. In this paper, the water-bag concept is used in a gyrokinetic context to study finite Larmor radius effects with the possibility of using the full Larmor radius distribution instead of an averaged Larmor radius. The resulting model is used to study the ion temperature gradient (ITG) instability.
A high performance normally closed solenoid-actuated cold valve
Authors: Taminiau I. A. J. , Benningshof O. W. B , Jochemsen R.
Published: August 2009

An electromagnetically driven normally closed valve for liquid helium is presented, which is meant to regulate the input flow to a 1 K pot. An earlier design is modified to be normally closed (not actuated) and tuned for durability and reliability. A new feature is presented which prevents seat deformation at room temperature and provides comfort and durability for intensive use.
Leaflike architecture for cooling a flat body
Authors: Combelles L. , Lorente S. , Bejan A.
Published: August 2009

The generation of heat in high-density electronics is concentrated in spots, not uniform. Here we account for this fundamental aspect as a phenomenon of heat conduction in a flat body, from a concentrated heat source to surface dissipation of heat to an external flow. To facilitate conduction through the body, the heat source is connected to the rest of the body (the blade) with a vein of considerably higher thermal conductivity. The architecture resembles a botanical leaf, in which the heat source deposits the heat current at the root of the vein, and the upper and lower surfaces of the leaf dissipate the heat current to the surrounding fluid flow. The optimal dimensions of this leaflike architecture are determined analytically and numerically: the blade length, width, and thickness, the vein cross-sectional area, and the global thermal conductance of the entire multiscale body. The optimized features are nondimensionalized and reported as power laws that show explicitly the design effect of external convection and the thermal conductivities of the vein and the blade.
Depth resolution function of the laser assisted tomographic atom probe in the investigation of semiconductors
Authors: Cadel Emmanuel , Vurpillot François , Lardé Rodrigue , Duguay Sébastien , Deconihout Bernard
Published: August 2009

The investigation of boron delta layers by tomographic atom probe (3DAP) is used to demonstrate that a depth profiling resolution of 0.9 nm (full width at half maximum) can be achieved. Results are compared with measurements provided by secondary ion mass spectrometry. The steepness is found to be below 1 nm/decade. In addition, silicon atomic planes are resolved in the real space demonstrating an in-depth spatial resolution of the 3DAP below 0.2 nm.