bluuebunny/crossref_metadata_2025 huggingface dataset:
SOME EXAMPLES IN VECTOR INTEGRATION
Authors: RODRÍGUEZ JOSÉ
Published: June 2009

Some classical examples in vector integration due to Phillips, Hagler and Talagrand are revisited from the point of view of the Birkhoff and McShane integrals.
THEC*-ALGEBRAS OF LATTICE ATOMIC GRAPHS
Authors: JING YANGPING
Published: June 2009

In this article, we define lattice graphs (which generalise ultragraphs) as well as their Cuntz–Krieger families andC*-algebras. We will give a thorough study in the special case of lattice atomic graphs.
ON SUPERNILPOTENT RADICALS WITH THE AMITSUR PROPERTY
Authors: FRANCE-JACKSON HALINA
Published: June 2009

A radical α has the Amitsur property if α(A[x])=(α(A[x])∩A)[x] for all rings A. For rings R⊆S with the same unity, we call S a finite centralizing extension of R if there exist b1,b2,…,bt∈S such that S=b1R+b2R+⋯+btR and bir=rbi for all r∈R and i=1,2,…,t. A radical α is FCE-friendly if α(S)∩R⊆α(R) for any finite centralizing extension S of a ring R. We show that if α is a supernilpotent radical whose semisimple class contains the ring ℤ of all integers and α is FCE-friendly, then α has the Amitsur property. In this way the Amitsur property of many well-known radicals such as the prime radical, the Jacobson radical, the Brown–McCoy radical, the antisimple radical and the Behrens radical can be established. Moreover, applying this condition, we will show that the upper radical 𝒰(*k) generated by the essential cover *k of the class * of all *-rings has the Amitsur property and 𝒰(*k)(A[x])=𝒰(*k)(A)[x], where a semiprime ring R is called a *-ring if the factor ring R/I is prime radical for every nonzero ideal I of R. The importance of *-rings stems from the fact that a *-ring A is Jacobson semisimple if and only if A is a primitive ring.
Effects of pomace olive oil-enriched diets on endothelial function of small mesenteric arteries from spontaneously hypertensive rats
Authors: Rodriguez-Rodriguez Rosalia , Herrera Maria Dolores , de Sotomayor Maria Alvarez , Ruiz-Gutierrez Valentina
Published: June 2009

Pomace olive oil (POM), an olive oil subproduct traditionally used in Spain, is a good source of minor components from the unsaponifiable fraction such as triterpenoids, mainly in the form of oleanolic acid, which induces vascular protection and vasodilatation. Our aim was to evaluate the effects of long-term intake of diets enriched in POM with high concentration in oleanolic acid on endothelial dysfunction associated to hypertension in small mesenteric arteries (SMA) from spontaneously hypertensive rats (SHR). During 12 weeks, rats (six rats per group) were fed either a control 2 % maize oil diet (BD), or high-fat diets containing 15 % refined olive oil (OL), pomace olive oil (POM), or pomace olive oil supplemented in oleanolic acid (POMO; up to 800 parts per million). Endothelial and vascular functions were assessed by relaxing or contracting responses to acetylcholine (ACh) or phenylephrine, respectively. The involvement of endothelium-derived relaxing factors in these responses was evaluated. In contrast to BD, SHR fed high-fat diets showed a biphasic response to ACh related to changes in eicosanoid metabolism. POM enhanced the endothelial function in SMA from SHR by increasing the endothelium-derived hyperpolarising factor (EDHF)-type component, whereas administration of POMO resulted in a similar contribution of NO/EDHF in the endothelial response to ACh. The present study shows that despite the lack of changes in blood pressure, consumption of POM improves endothelial function in SMA from SHR by improving the agonist-mediated EDHF/NO response. Thus, triterpenoids confer a protective role to POM against endothelial dysfunction in hypertension.
The Adaptive Markets Hypothesis: Evidence from the Foreign Exchange Market
Authors: Neely Christopher J. , Weller Paul A. , Ulrich Joshua M.
Published: June 2009

We analyze the intertemporal stability of excess returns to technical trading rules in the foreign exchange market by conducting true, out-of-sample tests on previously studied rules. The excess returns of the 1970s and 1980s were genuine and not just the result of data mining. But these profit opportunities had disappeared by the early 1990s for filter and moving average rules. Returns to less-studied rules also have declined but have probably not completely disappeared. High volatility prevents precise estimation of mean returns. These regularities are consistent with the Adaptive Markets Hypothesis (Lo (2004)), but not with the Efficient Markets Hypothesis.
Anchoring Bias in Consensus Forecasts and Its Effect on Market Prices
Authors: Campbell Sean D. , Sharpe Steven A.
Published: June 2009

Previous empirical studies on the “rationality” of economic and financial forecasts generally test for generic properties such as bias or autocorrelated errors but provide only limited insight into the behavior behind inefficient forecasts. This paper tests for a specific form of forecast bias. In particular, we examine whether expert consensus forecasts of monthly economic releases are systematically biased toward the value of previous months’ releases. Such a bias would be consistent with the anchoring and adjustment heuristic described by Tversky and Kahneman (1974) or could arise from professional forecasters’ strategic incentives. We find broad-based and significant evidence for this form of bias, which in some cases results in sizable predictable forecast errors. To investigate whether market participants’ expectations are influenced by this bias, we examine interest rate reactions to economic news. We find that bond yields react only to the residual, or unpredictable, component of the forecast error and not to the component induced by anchoring, suggesting that expectations of market participants anticipate this bias embedded in expert forecasts.
Founder-CEOs, Investment Decisions, and Stock Market Performance
Authors: Fahlenbrach Rüdiger
Published: June 2009

Eleven percent of the largest public U.S. firms are headed by the CEO who founded the firm. Founder-CEO firms differ systematically from successor-CEO firms with respect to firm valuation, investment behavior, and stock market performance. Founder-CEO firms invest more in research and development, have higher capital expenditures, and make more focused mergers and acquisitions. An equal-weighted investment strategy that had invested in founder-CEO firms from 1993 to 2002 would have earned a benchmark-adjusted return of 8.3% annually. The excess return is robust; after controlling for a wide variety of firm characteristics, CEO characteristics, and industry affiliation, the abnormal return is still 4.4% annually. The implications of the investment behavior and stock market performance of founder-CEO firms are discussed.
Testing International Asset Pricing Models Using Implied Costs of Capital
Authors: Lee Charles , Ng David , Swaminathan Bhaskaran
Published: June 2009

This paper tests international asset pricing models using firm-level expected returns estimated from an implied cost of capital approach. We show that the implied approach provides clear evidence of economic relations that would otherwise be obscured by the noise in realized returns. Among G-7 countries, expected returns based on implied costs of capital have less than one-tenth the volatility of those based on realized returns. Our tests show that firm-level expected returns increase with world market beta, idiosyncratic volatility, financial leverage, and book-to-market ratios, and decrease with currency beta and firm size.
Diet and trophic level of scaldfish Arnoglossus laterna in the southern Tyrrhenian Sea (western Mediterranean): contrasting trawled versus untrawled areas
Authors: Fanelli E. , Badalamenti F. , D'Anna G. , Pipitone C.
Published: June 2009

This study assesses the effects of bottom trawling on the feeding ecology of the scaldfish Arnoglossus laterna, by contrasting diets in an untrawled area and in two trawled areas off northern Sicily (western Mediterranean): the Gulf of Castellammare (which hosts a 200 km2 no-trawl area) and the gulfs of Termini Imerese and Sant'Agata. Scaldfish were collected in May–June 2005 using a commercial otter trawler between 40 and 80 m on muddy bottoms. Our data show that scaldfish is a selective feeder and consumes similar prey items in the three gulfs, although between-site differences in the relative prey abundance in the stomachs were detected. In the three gulfs scaldfish fed mainly on the crab Goneplax rhomboides and on the fish Lesueurigobius suerii, but there was an increase in the consumption of L. suerii and the shrimp Alpheus glaber in the trawled areas. Ontogenetic changes were evident in the diet of scaldfish, with juveniles preying mainly upon suprabenthic species, e.g. mysids and small decapods. While significant differences occurred in the diet of juveniles among all areas due to natural spatial variability, variations in the diet of adults, which feed on benthic prey, occurred between untrawled and trawled areas. These variations were clearly due to trawling disturbance, and no significant difference was detected in the diet of adults between the two trawled areas. On the contrary, the trophic level (δ15N values) of scaldfish did not vary between trawled and untrawled areas and between juveniles and adults. Changes in the source of carbon, as detected by δ13C values, were evident between juveniles and adults, evidencing a shift from a suprabenthic (juveniles) to a benthic (adults) diet.
Prevalence of hepatitis C virus infection in patients with COPD
Authors: SILVA D. R. , STIFFT J. , CHEINQUER H. , KNORST M. M.
Published: June 2009

Some studies have suggested that chronic hepatitis C virus (HCV) infection may induce an accelerated decline of forced expiratory volume in 1 second (FEV1). We performed a cross-sectional study to determine the prevalence of HCV infection in a sample of chronic obstructive pulmonary disease (COPD) patients and in a control group of blood donors. The clinical characteristics of HCV-positive and HCV-negative patients were compared. Anti-HCV antibody was determined and confirmed by HCV-RNA. The prevalence of HCV infection in COPD patients was 7·5% (95% CI 6·52–8·48) and in blood donors was 0·41% (95% CI 0·40–0·42). The HCV-positive patients had a lower FEV1(34·7±8·6%) and a higher BODE index (median=6) than HCV-negative patients (42·7±16·5%, median=4, respectively) (P=0·011 and 0·027, respectively). Our results suggest a high prevalence of chronic HCV infection in patients with COPD in comparison with the blood donors. HCV-positive patients have a more severe disease.
Learning lexical indexation
Authors: Coetzee Andries W.
Published: June 2009

Morphological concatenation often triggers phonological processes. For instance, addition of the plural suffix /-ən/ to Dutch nouns causes vowel lengthening in some nouns due to the stress-to-weight principle ([xɑt]vs. [ˈxaː.tən] ‘hole’). These kinds of processes often apply only to a subset of words – not all Dutch nouns undergo this process ([kɑt]vs. [ˈkɑ.tən] ‘cat’). Nouns need to be lexically indexed as either undergoing this process or not. I investigate how phonological grammar and lexical indexation are learned when learners are confronted with data like these. Based on learnability considerations, I hypothesise that learners acquire a grammar with default non-alternation, so that novel items are treated as non-alternating. I report the results of artificial language learning experiments compatible with this hypothesis, and model these results in a version of the Biased Constraint Demotion algorithm (Prince & Tesar 2004).
The Pontydian Performance: the performative layer
Authors: Schroeder Franziska , Rebelo Pedro
Published: June 2009

In this paper we reflect on the performer–instrument relationship by turning towards the thinking practices of the French philosopher Maurice Merleau-Ponty (1908–1961). Merleau-Ponty’s phenomenological idea of the body as being at the centre of the world highlights an embodied position in the world and bestows significance onto the body as a whole, onto the body as a lived body. In order to better understand this two-way relationship of instrument and performer, we introduce the notion of theperformative layer, which emerges through strategies for dealing with discontinuities, breakdowns and the unexpected in network performance.
Of Epistemic Tools: musical instruments as cognitive extensions
Authors: Magnusson Thor
Published: June 2009

This paper explores the differences in the design and performance of acoustic and new digital musical instruments, arguing that with the latter there is an increased encapsulation of musical theory. The point of departure is the phenomenology of musical instruments, which leads to the exploration of designed artefacts as extensions of human cognition – as scaffolding onto which we delegate parts of our cognitive processes. The paper succinctly emphasises the pronounced epistemic dimension of digital instruments when compared to acoustic instruments. Through the analysis of material epistemologies it is possible to describe the digital instrument as anepistemic tool: a designed tool with such a high degree of symbolic pertinence that it becomes a system of knowledge and thinking in its own terms. In conclusion, the paper rounds up the phenomenological and epistemological arguments, and points at issues in the design of digital musical instruments that are germane due to their strong aesthetic implications for musical culture.
Understanding Interaction in Contemporary Digital Music: from instruments to behavioural objects
Authors: Bown Oliver , Eldridge Alice , McCormack Jon
Published: June 2009

Throughout the short history of interactive digital music, there have been frequent calls for a new language of interaction that incorporates and acknowledges the unique capabilities of the computational medium. In this paper we suggest that a conceptualisation of possible modes of performance–time interaction can only be sensibly approached in light of the ways that computers alter the social–artistic interactions that are precursive to performance. This conceptualisation hinges upon a consideration of the changing roles of composition, performer and instrument in contemporary practice. We introduce the termbehavioural objectto refer to software that has the capacity to act as the musical and social focus of interaction in digital systems. Whilst formative, this term points to a new framework for understanding the role of software in musical culture. We discuss the potential for behavioural objects to contribute actively to musical culture through two types of agency:performative agencyandmemetic agency.
Food variety, socioeconomic status and nutritional status in urban and rural areas in Koutiala (Mali)
Authors: Hatløy Anne , Hallund Jesper , Diarra Modibo M , Oshaug Arne
Published: June 2009

Objective:The purpose of this study was to analyse the associations between the food variety score (FVS), dietary diversity score (DDS) and nutritional status of children, and to assess the associations between FVS, DDS and socioeconomic status (SES) on a household level. The study also assessed urban and rural differences in FVS and DDS.

Design:Cross-sectional studies in 1994/95, including a simplified food frequency questionnaire on food items used in the household the previous day. A socioeconomic score was generated, based on possessions in the households. Weight and height were measured for all children aged 6–59 months in the households, and anthropometric indices were generated.

Subjects and setting:Three hundred and twenty-nine urban and 488 rural households with 526 urban and 1789 rural children aged 6–59 months in Koutiala County, Sikasso Region, Mali.

Results:Children from urban households with a low FVS or DDS had a doubled risk (OR>2) for being stunted and underweight. Those relations were not found in the rural area. There was an association between SES and both FVS and DDS on the household level in both areas. The FVS and DDS in urban households with the lowest SES were higher than the FVS and DDS among the rural households with the highest SES.

Conclusions:Food variety and dietary diversity seem to be associated with nutritional status (weight/age and height/age) of children in heterogeneous communities, as our data from urban areas showed. In rural areas, however, this association could not be shown. Socioeconomic factors seem to be important determinants for FVS and DDS both in urban and rural areas. FVS and DDS are useful variables in assessing the nutritional situation of households, particular in urban areas.
Radiotherapy research activity and radiographer involvement in the UK
Authors: Davies Julie , Rawlings Christine
Published: June 2009

In the UK, radiotherapy research is being conducted at national and international levels which include multi-centre clinical trials. Local initiatives and trials are also ongoing where work is being performed to develop techniques or protocols for new technologies and service development. Active participation within these studies is now leading to a culture change with radiographers (radiation therapists) becoming an integral part of the research process. There are currently 70 radiographers in the UK participating in research. This accounts for 2.5% of the UK profession. With the extension of role diversification, research radiographers are undertaking many new roles; however, there is still scope for further development. The therapists’ role in working within this research environment is to ensure improved standards of care focussed on evidence-based practice.
Radiation therapist research in Africa: overcoming the barriers to reap the rewards
Authors: Engel-Hills Penelope C.
Published: June 2009

Radiation therapy is recognised throughout the world as an essential modality in the treatment of many malignant diseases. A quality treatment process requires highly competent health care professionals and high-technology equipment. In the majority of countries in Africa there is a desperate need for equipment and skilled therapists and in many countries there is no access to radiation therapy to relieve the suffering of cancer patients. As a region, Africa can therefore be considered as ‘under resourced’ in terms of radiation oncology services. In this context both service and research are challenged by a lack of equipment, poor maintenance, inadequate funding, inconsistent consumable supplies, a scarcity of competent professionals to ensure optimal use of what is available and excessive workload. Africa therefore has many examples of the situation, where low-income countries generally have a poor research infrastructure. Radiation therapist (RTT) research in Africa has to develop where the barriers to research can in most instances be traced back to a lack of resources and any initiatives to overcome these barriers are frequently blocked by the limitations of a resource-poor environment. To locate the discussion on the research environment of RTTs in Africa, barriers to and benefits of research are integrated with brief information under the following headings: the macro environment, the RTT environment and the RTT research environment. The latter includes insights from interviews and discussions covering the following topics: research now, research priorities, research opportunities and strategies for future research.
Networking to deliver research: Research radiographers within the Academic Clinical Oncology and Radiobiology Research Network (ACORRN)
Authors: Heap G. , Stones Nicola
Published: June 2009

ACORRN was established in response to the sharp decline in the number of clinical academics and radiation biologists over the past ten years. The network was launched in 2005 to help revitalise radiotherapy and radiobiology research in the UK by networking and supporting individuals and groups. ACORRN is governed by a Steering Committee, comprising members of the UK research community and receives advice from an International Scientific Advisory Committee. Since its inception ACORRN has established a national office to support researchers, providing practical advice and assistance on funding streams, grant applications, ethics legislation and approval as well as facilitating collaborative research meetings. ACORRN has also developed several working parties, research interest groups and an interactive website (www.acorrn.org) which is actively used within the research community. The website serves as a hub of information allowing researchers to locate and contact each other and search for information on projects, institutions and opportunities, quickly and easily.
What research means to patients, and the importance of partnership with practitioners in research
Authors: Thornton Hazel
Published: June 2009

A brief general and personal history of research conducted in partnership with patients is outlined in order to substantiate the beneficial effect of this method in improving the quality of research and to illustrate the importance to patients of testing treatments in a manner that takes account of the outcomes they seek. Examples of two early initiatives, Radiotherapy Action Group Exposure (RAGE) and the Consumers' Advisory Group for Clinical Trials (CAG-CT), are used to demonstrate what can be accomplished by committed groups of patients working with policy makers and practitioners to improve the quality and provision of treatments for breast cancer.
Self-deceit and self-serving bias: Adam Smith on ‘General Rules’
Authors: KHALIL ELIAS L.
Published: June 2009

Adam Smith (1982) undertook a momentous project inThe Theory of Moral Sentiments(TMS): He wanted to debunk the Cartesian dichotomy between the emotions (body) and rationality (mind). The debunking of the body/mind dichotomy is a major aim of many modern neuroscientists and neuroeconomists (e.g., Damasio, 1994; Glimcher, 2004; Rustichini, 2005). Smith also wanted to demonstrate that morality is grounded on the emotions – as the title of his book indicates. So for Smith, the twin pillars of what thinkers consider to be distinguishably human, namely, rationality and morality, are actually rooted in the emotions (body). More specifically, while rationality and morality are based on the emotions, Smith showed that the emotions are rather refined and sophisticated sentiments adopted by agents in light of how they judge the actions of others and, in turn, how they should judge their own actions. Such judgments are nothing but the determination of what is the rational (optimal) solution. So, sentiments are not hurdles in the pathway of rational decisions. They are rather the building blocks of such decisions.
Das präoperative anästhesiologische Patientengespräch
Authors: Harms Christoph , Kindler Christoph H.
Published: June 2009

Anästhesisten treffen ihre Patienten häufig in Ausnahmesituationen an, geprägt von Angst und großer Unsicherheit. Selbst zeitlich kurze Kontakte sind daher meist intensiv und bedeutsam. Das persönliche, anästhesiologische Gespräch steht am Beginn der Beziehung von Patient und Anästhesist und soll die geplanten Maßnahmen, welche der Anästhesist durchführen wird, erklären und begleiten. Ein solches Gespräch dauert heute durchschnittlich 20 Minuten. Es beinhaltet die Erhebung der Anamnese, die strukturierte und verständliche Informationsübermittlung zwischen Anästhesist und Patient (inklusive Informationen über die anästhesiologischen Interventionen, Instruktionen zum Verhalten des Patienten und die offene und klare Kommunikation von Vor- und Nachteilen sowie Risiken möglicher Anästhesieverfahren) sowie den professionellen Umgang mit den Emotionen des Patienten, insbesondere seiner präoperativen Angst. Da Patienten heute in der Anästhesiologie vermehrt in den Entscheidungsprozess mit einbezogen werden, entwickelt sich dieses Gespräch zunehmend von einer eher paternalistischen Arzt-Patienten Interaktion zu einer gemeinsamen Entscheidungsfindung, dem so genannten „shared decision making“. Formal sollte das präoperative Gespräch die bekannten Voraussetzungen für eine erfolgreiche Verständigung zwischen Patient und Arzt wie Deutlichkeit, Eindeutigkeit, identische Kodierung, Empathie und Rückmeldung erfüllen und mit dem einholen eines „informed consent“ enden.
Atemwege und respiratorische Funktion – präoperative Beurteilung Anästhesiologische und intensivmedizinische Aspekte und Empfehlungen
Authors: Reber Adrian
Published: June 2009

Pulmonale Komplikationen treten sowohl bei pulmonalen und kardialen Risikopatienten als auch bei Patienten mit geringem Risiko vor allem postoperativ auf. Ist eine Operation notwendig, so gilt es nicht nur die richtige Indikation zu stellen, sondern auch den Zeitpunkt mit dem geringsten Risiko und der niedrigsten Komplikationswahrscheinlichkeit zu wählen. Operateur und Anästhesist teilen sich gemeinsam die perioperative Verantwortung. Der Hausarzt seinerseits, resp. der im Vorfeld der anstehenden Hospitalisation behandelnde Arzt, kennt den Patienten oft bereits über Monate/Jahre und kann mit seiner Expertise wesentliche Informationen beisteuern. In dieser Übersicht wird auf anästhesiologische Aspekte der Atemwege und Lunge eingegangen, im speziellen patienten- und operationsassoziierte Risikofaktoren durchleuchtet.
Lebereingriffe – präoperatives Management
Authors: Voigtsberger Stefanie , Breitenstein Stefan , Beck-Schimmer Beatrice
Published: June 2009

Die Behandlung von Patienten mit benignen oder malignen Lebertumorerkrankungen erfolgt oft interdisziplinär durch die Fachbereiche Chirurgie, Gastroenterologie, Anästhesiologie, Intensivmedizin, Radiologie, Onkologie und Pathologie. Chirurgische Technik, kombiniert mit einem breiten Spektrum an diagnostischen und therapeutischen Möglichkeiten, sorgen für ein hohes Maß an Sicherheit und Effektivität, vor allem bei komplexen, ausgedehnten chirurgischen Lebereingriffen. Der allgemein körperliche Zustand des Patienten, die Art und das Ausmaß der Lebererkrankung sowie der Umfang der Leberresektion haben einen großen Einfluss auf die perioperative Morbidität und Mortalität. Eine entsprechende präoperative Evaluation und Vorbereitung dieser Patienten ist daher äußerst wichtig. Sie hilft nicht nur die perioperativen Risiken abzuschätzen, sondern beeinflusst auch die therapeutische Strategie und damit den Erfolg der Behandlung.
What does chlorophyll variability tell us about export and air‐sea CO2 flux variability in the North Atlantic?
Authors: Bennington Val , McKinley Galen A. , Dutkiewicz Stephanie , Ullman David
Published: June 2009

The importance of biology to the ocean carbon sink is often quantified in terms of export, the removal of carbon from the ocean surface layer. Satellite images of sea surface chlorophyll indicate variability in biological production, but how these variations affect export and air‐sea carbon fluxes is poorly understood. We investigate this in the North Atlantic using an ocean general circulation model coupled to a medium‐complexity ecosystem model. We find that biological CO2 drawdown is significant on the mean and dominates the seasonal cycle of pCO2, but variations in the annual air‐sea CO2 flux and export are not significantly correlated. Large year‐to‐year variability in summertime pCO2 occurs, because of changing bloom timing, but integrated bloom strength and associated carbon uptake and export do not vary substantially. The model indicates that small biological variability, quantitatively consistent with SeaWiFS (1998–2006), is not sufficient to be a first‐order control on annual subpolar air‐sea CO2 flux variability.
Effect of uncertainties in climatologic wind, ocean pCO2, and gas transfer algorithms on the estimate of global sea‐air CO2 flux
Authors: Signorini Sergio R. , McClain Charles R.
Published: June 2009

This paper addresses the uncertainties of global sea‐air CO2 flux estimated on the basis of the sea‐air pCO2 differences and sea‐air CO2 gas transfer rate. Uncertainties in the global sea‐air flux estimates are identified from different gas transfer algorithms and monthly wind speeds (NCEP‐2 and SSM/I). The net global sea‐air flux estimates for the contemporary oceans range from 0.9 ± 0.5 Pg‐C a−1 to 1.3 ± 0.8 Pg‐C a−1 for reference year 2000. Including the carbon transferred from rivers in the preindustrial steady oceans, the uptake rates for anthropogenic CO2 range from 1.3 ± 0.6 Pg‐C a−1 to 1.7 ± 0.8 Pg‐C a−1. For all three gas exchange parameterizations used, the difference between global fluxes using SSM/I and NCEP‐2 winds ranged between 3% and 37%. The subtropical regions are the largest sinks of CO2 (–0.8 Pg‐C a−1), and the equatorial Pacific is the largest source (0.4 Pg‐C a−1). The North Pacific (–0.4 Pg‐C a−1) and the North Atlantic (–0.3 Pg‐C a−1) are also significant sinks of CO2. All the remaining regions have relatively weak net yearly exchanges of CO2. Recent estimates (Takahashi et al., 2009) of sea‐air CO2 flux in the ice‐free zone of the Southern Ocean (50°S−62°S) reveal a small mean annual flux (–0.06 Pg‐C a−1) resulting from the cancellation of the summer uptake CO2 flux with the winter release of CO2 caused by deepwater upwelling. Our study results for the same region range from –0.03 to –0.06 Pg‐C a−1, which are within the uncertainties of the estimates.
Observation of the seismic anisotropy effects on free oscillations below 4 mHz
Authors: Hu X. G. , Liu L. T. , Kroner C. , Sun H. P.
Published: June 2009

We present observations of significant fundamental spheroidal‐toroidal mode coupling at frequencies below 4 mHz in the early part of vertical component records from seismic stations on near‐equatorial source‐receiver propagation paths after the 26 December 2004 and 28 March 2005 great Sumatra earthquakes. Since the mixed‐type coupling induced by rotational Coriolis force are very weak at these selected equatorial‐path stations, we investigate what effects mimic the strong Coriolis effects at frequencies below 4 mHz, suggesting that local azimuthal anisotropy in the upper mantle is the most likely explanation for the strong anomalous coupling we observed. In addition, strong anisotropy coupling observed in the frequency band of 1–4 mHz is always characterized by anomalous small amplitudes of coupled spheroidal modes on the vertical component of seismograph, suggesting that excitation of quasi‐toroidal modes by azimuthal anisotropy associates with geometric nodes of fundamental spheroidal modes.
A silent Mw 4.7 slip event of October 2006 on the Superstition Hills fault, southern California
Authors: Wei Meng , Sandwell David , Fialko Yuri
Published: June 2009

During October 2006, the 20‐km‐long Superstition Hills fault (SHF) in the Salton Trough, southern California, slipped aseismically, producing a maximum offset of 27 mm, as recorded by a creepmeter. We investigate this creep event as well as the spatial and temporal variations in slip history since 1992 using ERS‐1/2 and Envisat satellite data. During a 15‐year period, steady creep is punctuated by at least three events. The first two events were dynamically triggered by the 1992 Landers and 1999 Hector Mine earthquakes. In contrast, there is no obvious triggering mechanism for the October 2006 event. Field measurements of fault offset after the 1999 and 2006 events are in good agreement with the interferometric synthetic aperture radar data indicating that creep occurred along the 20‐km‐long fault above 4 km depth, with most of the slip occurring at the surface. The moment released during this event is equivalent to a Mw 4.7 earthquake. This event produced no detectable aftershocks and was not recorded by the continuous GPS stations that were 9 km away. Modeling of the long‐term creep from 1992 to 2007 creep using stacked ERS‐1/2 interferograms also shows a maximum creep depth of 2–4 km, with slip tapering with depth. Considering that the sediment thickness varies between 3 km and 5 km along the SHF, our results are consistent with previous studies suggesting that shallow creep is controlled by sediment depth, perhaps due to high pore pressures in the unconsolidated sediments.
Thermal structure of a gas‐permeable lava dome and timescale separation in its response to perturbation
Authors: Hicks Peter D. , Matthews Adrian J. , Cooker Mark J.
Published: June 2009

The thermal boundary layer at the surface of a volcanic lava dome is investigated through a continuum model of the thermodynamic advection‐diffusion processes resulting from magmatic gas flow through the dome matrix. The magmatic gas mass flux, porosity, and permeability of the rock are identified as key parameters. New, theoretical, nonlinear steady state thermal profiles are reported, which give a realistic surface temperature of 210°C for a region of lava dome surface through which a gas flux of 3.5 × 10−3 kg s−1 m−2 passes. This contrasts favorably with earlier purely diffusive thermal models, which cool too quickly. Results are presented for time‐dependent perturbations of the steady states as a response to changes in surface pressure, a sudden rockfall from the lava dome surface, and a change in the magmatic gas mass flux at depth. Together with a generalized analysis using the method of multiple scales, this identifies two characteristic timescales associated with the thermal evolution of a dome carapace: a short timescale of several minutes, over which the magmatic gas mass flux, density, and pressure change to a new quasi‐steady state and a longer timescale of several days, over which the thermal profile changes to a new equilibrium distribution. Over the longer timescale, the dynamic properties of the dome continue to evolve, but only in slavish response to the ongoing temperature evolution. In light of this timescale separation, the use of surface temperature measurements to infer changes in the magmatic gas flux for use in volcanic hazard prediction is discussed.
Direct estimates of the Indonesian Throughflow entering the Indian Ocean: 2004–2006
Authors: Sprintall Janet , Wijffels Susan E. , Molcard Robert , Jaya Indra
Published: June 2009

The mean and variable transport of the Indonesian Throughflow (ITF) are determined from full‐depth velocity measurements in the three major exit passages of Lombok Strait, Ombai Strait, and Timor Passage from January 2003 through December 2006. Collectively, these passages convey the full‐depth transport and stratification profile of the ITF from the Pacific Ocean to the Indian Ocean. To first order, the seasonal cycle of transport in the thermocline (∼100–150 m) in all three exit straits is dominated by regional monsoon forcing, with maximum ITF during the southeast monsoon. During the northwest monsoon, the surface transport relaxes in Timor and weakly reverses in Ombai and Lombok, so the main core of the ITF is subsurface. Below the thermocline, semiannual reversals occur in all three straits during the monsoon transitions in response to the passage of Indian Ocean wind‐forced Kelvin waves. However, the reversals occur over different depth levels in each passage reflecting the influence of different sill depths along the coastal waveguide. The seasonal cycle of depth‐integrated transports in Lombok and Ombai are strongly out of phase with Timor Passage, suggesting that the subthermocline flow is largely gated by these Kelvin waves. Despite the different seasonal transport phases, interannual anomalies in all three passages are remarkably similar, particularly during the strong positive Indian Ocean Dipole event in 2006 when transport in the surface layer is toward the Indian Ocean and reversed below. The deep reversals are likely in response to a series of Kelvin waves driven by anomalous zonal winds in the equatorial Indian Ocean. Total mean transport over the 3‐year period is −2.6 Sv in Lombok Strait (i.e., toward the Indian Ocean), −4.9 Sv in Ombai Strait, and −7.5 Sv in Timor Passage. The transport in Timor Passage is nearly twice as large as historical estimates and represents half of the −15 Sv full‐depth ITF transport that enters the Indian Ocean.
Radiocarbon age anomaly at intermediate water depth in the Pacific Ocean during the last deglaciation
Authors: Stott Lowell , Southon John , Timmermann Axel , Koutavas Athanasios
Published: June 2009

Benthic and planktonic 14C ages are presented for the last glacial termination from marine sediment core VM21‐30 from 617 m in the eastern equatorial Pacific. The benthic‐planktonic 14C age differences in the core increased to more than 6000 years between Heinrich 1 time and the end of the Younger Dryas period. Several replicated 14C ages on different benthic and planktonic species from the same samples within the deglacial section of the core indicate a minimal amount of bioturbation. Scanning electron microscopy reveals no evidence of calcite alteration or contamination. The oxygen isotope stratigraphy of planktonic and benthic foraminifera does not indicate anomalously old (glacial age) values, and there is no evidence of a large negative stable carbon isotope excursion in benthic foraminifera that would indicate input of old carbon from dissociated methane. It appears, therefore, that the benthic 14C excursion in this core is not an artifact of diagenesis, bioturbation, or a pulse of methane. A benthic Δ14C stratigraphy reconstructed from the 14C ages from the deglacial section of VM21‐30 appears to match that of Baja margin core MV99‐MC19/GC31/PC08 (705 m), but the magnitude of the low‐14C excursion is much larger in the VM21‐30 record. This would seem to imply that the VM21‐30 core was closer to the source of 14C‐depleted waters during the deglaciation, but the source of this CO2 remains elusive.
Kalman filter estimation of plasmaspheric total electron content using GPS
Authors: Carrano Charles S. , Anghel Adela , Quinn Richard A. , Groves Keith M.
Published: June 2009

We extend a Kalman filter technique for GPS total electron content (TEC) estimation by explicitly accounting for the contribution to the line‐of‐sight TEC from the plasmasphere. The plasmaspheric contribution is determined by integrating the electron density predicted by the Carpenter‐Anderson model along GPS raypaths and allowing the Kalman filter to scale the results to fit the observations. The filter also estimates the coefficients of a local fit to the ionospheric TEC and the receiver and satellite instrumental biases. We compare algorithm results with and without the plasmasphere term for three GPS receivers located at different latitudes. We validate the approach by comparing ionospheric TEC estimates with Advanced Research Projects Agency Long‐range Tracking and Instrumentation Radar measurements along coincident lines of sight to calibration objects in low Earth orbit. We find the technique is effective at separating the ionospheric and plasmaspheric contributions to the TEC by exploiting differences in the spatial distributions of electron density, and the time scales on which they vary, in these two regions.
Simultaneous radio interferometer and optical observations of ionospheric structure at the Very Large Array
Authors: Coker Clayton , Thonnard Stefan E. , Dymond Kenneth F. , Lazio T. Joseph W. , Makela Jonathan J. , Loughmiller Pamela J.
Published: June 2009

Radio astronomers are searching the cosmos for new scientific discoveries at increasingly lower radio frequencies and with larger antenna arrays, but their observations of the sky are blurred by the dynamic ionosphere. At the same time, ionospheric scientists are seeking to understand, at increasingly higher spatial and temporal resolutions, the dynamics that drive the ionosphere and its effects on technological systems. Advancements in radio astronomy at the Very Large Array (VLA) are leading to advancements in ionospheric physics and vice versa. We review some of the ionospheric observations made by the VLA at low frequency. Results from a 2003 summer campaign at the VLA are discussed, during which an all‐sky optical camera was used to monitor ionospheric structure during VLA 74‐MHz operations. The camera and additional off‐site sensors, including ionosondes and incoherent scatter radar, were used to identify the dominant, summer nighttime ionospheric phenomena contributing to VLA signal distortion. Knowledge of the specific phenomena, including their spatial and temporal characteristics, can be used to improve low‐frequency, astronomical imaging. Similarly, the VLA observations can be used to investigate ionospheric phenomena in great detail, leading to an improved understanding of ionospheric physics. Key to these findings is the identification of specific ionospheric phenomena using support sensors. Implications for the development of the Long Wavelength Array are discussed.
Momentum flux estimates for South Georgia Island mountain waves in the stratosphere observed via satellite
Authors: Alexander M. Joan , Eckermann Stephen D. , Broutman Dave , Ma Jun
Published: June 2009

We show high‐resolution satellite observations of mountain wave events in the stratosphere above South Georgia Island in the remote southern Atlantic Ocean and compute the wave momentum fluxes for these events. The fluxes are large, and they imply important drag forces on the circulation. Small island orography is generally neglected in mountain wave parameterizations used in global climate models because limited model resolution treats the grid cell containing the island as ocean rather than land. Our results show that satellite observations can be used to quantitatively constrain mountain wave momentum fluxes, and they suggest that mountain waves from island topography may be an important missing source of drag on the atmospheric circulation.
Reductions of NO2 detected from space during the 2008 Beijing Olympic Games
Authors: Mijling B. , van der A R. J. , Boersma K. F. , Van Roozendael M. , De Smedt I. , Kelder H. M.
Published: June 2009

During the 2008 Olympic and Paralympic Games in Beijing (from 8 August to 17 September), local authorities enforced strong measures to reduce air pollution during the events. To evaluate the direct effect of these measures, we use the tropospheric NO2 column observations from the satellite instruments GOME‐2 and OMI. We interpret these data against simulations from the regional chemistry transport model CHIMERE, based on a 2006 emission inventory, and find a reduction of NO2 concentrations of approximately 60% above Beijing during the Olympic period. The air quality measures were especially effective in the Beijing area, but also noticeable in surrounding cities of Tianjin (30% reduction) and Shijiazhuang (20% reduction).
Quantitative forecasting of near‐term solar activity and upper atmospheric density
Authors: Lean J. L. , Picone J. M. , Emmert J. T.
Published: June 2009

Autoregressive algorithms are developed to forecast solar activity on timescales of 1 to 10 days and utilized to forecast upper atmospheric densities using the NRLMSIS density specification model. Quantitative assessment of solar activity observations and forecasts made over 27 years (from 1980 to 2006) indicates that the chromospheric Mg index is superior to the coronal F10.7 radio flux, both as a proxy for the day‐to‐day EUV irradiance variations that drive density changes and as an input to empirical models for density forecasts. For 1‐ to 10‐day Mg forecasts, the average of the root‐mean‐square error (evaluated in 81‐day windows and averaged over the 27 years) increases from 3% to 13%; for F10.7, the corresponding forecast uncertainty increases from 5% to 20%. We demonstrate how the use of Mg instead of F10.7 reduces the errors in forecasting upper atmospheric density changes by comparing orbit‐derived and forecast density changes along the tracks of two low earth‐orbiting objects. For the Yohkoh orbit, the 3‐day Mg and F10.7 forecasts have average root‐mean‐square errors of 29% and 30%, respectively. For the 10‐day solar activity forecasts, the errors are 37% and 41%. Although the improvement using Mg is evident, density uncertainties arising from errors in the solar activity forecasts are on average three to five times smaller than the uncertainties in the combined NRLMSIS density specification model and density data. To improve density forecasts, better characterization of the upper atmospheric response to solar and other drivers is needed.
Is solar dimming global or urban? Evidence from measurements in Israel between 1954 and 2007
Authors: Stanhill Gerald , Cohen Shabtai
Published: June 2009

Daily values of global radiation Eg↓ measured in a network of six sites within the greater Tel Aviv region indicated a maximum urban dimming effect of 7% with a similar day‐to‐day range in differences during the week that was significantly negatively related to the number of vehicles using the roads. Interannual variability of Eg↓ differed between three regions of Israel having very diverse population densities, both in their overall trends and in their rates of change during periods of dimming and brightening. During the 50 years of measurement the overall trends in all regions were negative; the rates of dimming were related to the logarithm of the mean population densities with the greatest net rate of dimming, −3.4% per decade, measured at the downwind edge of the densely populated Tel Aviv conurbation. Rates of change in the dimming and brightening periods were not related to the rates of change in population; maximum rates of both dimming and brightening were measured at the Dead Sea, a desert region with a low and unchanging population. Trends in maximum, minimum, mean, and diurnal range air temperatures were significant and differed between regions, but these differences were not clearly related to those in Eg↓ or in population density. The results indicate that in Israel the maximum urban effects on Eg↓ were insufficient to explain the large interannual variability measured during the last 50 years and that population density was not a robust proxy for global radiation change.
The roles of interferon‐γ and perforin in antiviral immunity in mice that differ in genetically determined NK‐cell‐mediated antiviral activity
Authors: Sumaria Nital , van Dommelen Serani L H , Andoniou Christopher E , Smyth Mark J , Scalzo Anthony A , Degli‐Esposti Mariapia A
Published: June 2009

The design of effective antiviral immunotherapies depends on a detailed understanding of the cellular and molecular processes involved in generating and maintaining immune responses. Control of cytomegalovirus (CMV) infection requires the concerted activities of both innate and adaptive immune effectors. In the mouse, immunity to acute murine CMV (MCMV) infection depends on natural killer (NK) cells and/or CD8+ T cells. The relative importance of NK and CD8+ T cells varies in different mouse strains. In C57BL/6 mice, early viral infection is controlled by Ly49H+ NK cells, whereas in BALB/c mice, CD8+ T cells exert the principal antiviral activities. Although the role of NK and CD8+ T cells is defined, the molecular mechanisms they utilize to limit acute infection are poorly understood. Here, we define the specific roles of perforin (pfp) and interferon‐γ (IFN‐γ) in the context of NK‐ or T‐cell‐mediated immunity to MCMV during acute infection. We show that pfp is essential for both NK‐ and T‐cell‐mediated antiviral immunity during the early stages of infection. The relative importance of IFN‐γ is more pronounced in Ly49H‐‐ mice. Using BALB/c background mice congenic for Ly49H and lacking pfp, we show that Ly49H‐regulated NK‐cell control of MCMV infection is dependent on pfp‐mediated cytolysis.