bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of a propensity score adjustment in longitudinal studies with covariate‐dependent representation
Authors: Leon Andrew C. , Hedeker Donald , Li Chunshan , Demirtas Hakan
Published: April 2012

Longitudinal observational studies provide rich opportunities to examine treatment effectiveness during the course of a chronic illness. However, there are threats to the validity of observational inferences. For instance, clinician judgment and self‐selection play key roles in treatment assignment. To account for this, an adjustment such as the propensity score can be used if certain assumptions are fulfilled. Here, we consider a problem that could surface in a longitudinal observational study and has been largely overlooked. It can occur when subjects have a varying number of distinct periods of therapeutic intervention. We evaluate the implications of baseline variables in the propensity model being associated with the number of post baseline observations per subject and refer to it as ‘covariate‐dependent representation’. An observational study of antidepressant treatment effectiveness serves as a motivating example. The analyses examine the first 20 years of follow‐up data from the National Institute of Mental Health Collaborative Depression Study, a longitudinal, observational study. A simulation study evaluates the consequences of covariate‐dependent representation in longitudinal observational studies of treatment effectiveness under a range of data specifications.The simulations found that estimates were adversely affected by underrepresentation when there was lower ICC among repeated doses and among repeated outcomes. Copyright © 2012 John Wiley & Sons, Ltd.
Effects of Music on Immunity and Physiological Responses in Healthcare Workers: A Randomized Controlled Trial
Authors: Lai Hui‐Ling , Liao Kuang‐Wen , Huang Chiung‐Yu , Chen Pin‐Wen , Peng Tai‐Chu
Published: April 2012

Research‐based evidence supports the effectiveness of soothing music in improving stress‐related psycho‐physiological indices in a clinical setting. However, there is currently insufficient scientific knowledge of the effects of music on immune markers of stress in humans. Therefore, the aims of the study were to compare the effects of music and quiet rest on the levels of interleukin‐6 (IL‐6), tumour necrosis factor‐α (TNF‐α), interleukin‐10 (IL‐10), heart rate and mean arterial pressure among healthcare workers. By using a randomized controlled trial design, 60 nurses were randomly assigned to the stimulating or sedating music or rest groups for 30 min. Participants' psychoneuroimmunological parameters were measured using enzyme‐linked immunosorbent assays. General estimating equation was used to analyse data. Results revealed that IL‐6, TNF‐α and IL‐10 were not detectable in this population. No significance differences in heart rate were found among the three groups. However, the stimulating music group had significantly higher mean arterial pressure levels than the sedating music group but no differences between the quiet rest group and the sedating music group. Music with different tempi had little effect on mean arterial pressure. Any effect of music on immune markers of stress requires further research. Copyright © 2012 John Wiley & Sons, Ltd.
Electroencephalographic activity in neonatal ventral hippocampus lesion in adult rats
Authors: ValdéS‐Cruz ALejandro , Negrete‐DíAZ José Vicente , Magdaleno‐Madrigal Victor Manuel , MartíNez‐Vargas David , FernáNdez‐Mas Rodrigo , AlmazáN‐Alvarado Salvador , Torres‐GarcÍA MaríA Evelina , Flores Gonzalo
Published: April 2012

A neonatal ventral hippocampal lesion (NVHL) in rats has been commonly used as a neurodevelopmental model to mimic schizophrenia‐like behaviors. Recently, we reported that NVHL resulted in dendritic retraction and spine loss in pyramidal neurons of the prefrontal cortex (PFC). In addition, the hippocampus and PFC are important structures in the regulation of the electroencephalographic (EEG) activity. Patients with PFC lesions show deficits in the EEG activity. This study aimed to determine whether the EEG activity was altered in NVHL rats. In addition, we also analyzed the locomotor activity induced by a novel environment and exploratory behavior using the hole‐board test. Consistent with the behavioral findings, the EEG analysis of the cortical regions showed that the NVHL rats displayed a lower power in cortical bands. At 1–8 Hz, 9–14 Hz, and 15–30 Hz bands, our findings showed a decrease in the absolute power of the parietal and occipital cortices recordings. In addition, the NVHL rats also showed a reduction in the exploratory behavior tested using the hole‐board test. In conclusion, this study demonstrated that the EEG activity was reduced in adult NVHL rats and suggests that this may play a role in the behavioral changes observed in this neurodevelopmental model of schizophrenia. Synapse, 2012. © 2012 Wiley Periodicals, Inc.
Implementation of electroweak corrections in the POWHEG BOX: single W production
Authors: Barzè Luca , Montagna Guido , Nason Paolo , Nicrosini Oreste , Piccinini Fulvio
Published: April 2012

Abstract

We present a fully consistent implementation of electroweak and strong radiative corrections to single W hadroproduction in the POWHEG BOX framework, treating soft and collinear photon emissions on the same ground as coloured parton emissions. This framework can be easily extended to more complex electroweak processes. We describe how next-to-leading order (NLO) electroweak corrections are combined with the NLO QCD calculation, and show how they are interfaced to QCD and QED shower Monte Carlo. The resulting tool fills a gap in the literature and allows to study comprehensively the interplay of QCD and electroweak effects to W production using a single computational framework. Numerical comparisons with the predictions of the electroweak generator HORACE, as well as with existing results on the combination of electroweak and QCD corrections to W production, are shown for the LHC energies, to validate the reliability and accuracy of the approach.
The 4D composite Higgs
Authors: De Curtis Stefania , Redi Michele , Tesi Andrea
Published: April 2012

Abstract

We propose a four dimensional description of Composite Higgs Models which represents a complete framework for the physics of the Higgs as a pseudo-Nambu-Goldstone boson. Our setup captures all the relevant features of 5D models and more in general of composite Higgs models with partial compositeness. We focus on the minimal scenario where we include a single multiplet of resonances of the composite sector, as these will be the only degrees of freedom which might be accessible at the LHC. This turns out to be sufficient to compute the effective potential and derive phenomenological consequences of the theory. Moreover our simplified approach is well adapted to simulate these models at the LHC. We also consider the impact of non-minimal terms in the effective lagrangian which do not descend from a 5D theory and could be of phenomenological relevance, for example contributing to the S − parameter.
Refined Hopf link revisited
Authors: Iqbal Amer , Kozçaz Can
Published: April 2012

Abstract

We establish a relation between the refined Hopf link invariant and the S-matrix of the refined Chern-Simons theory. We show that the refined open string partition function corresponding to the Hopf link, calculated using the refined topological vertex, when expressed in the basis of Macdonald polynomials gives the S-matrix of the refined Chern-Simons theory.
Asymptotically optimal Bayesian sequential change detection and identification rules
Authors: Dayanik Savas , Powell Warren B. , Yamazaki Kazutoshi
Published: April 2012

We study the joint problem of sequential change detection and multiple hypothesis testing. Suppose that the common distribution of a sequence of i.i.d. random variables changes suddenly at some unobservable time to one of finitely many distinct alternatives, and one needs to both detect and identify the change at the earliest possible time. We propose computationally efficient sequential decision rules that are asymptotically either Bayes-optimal or optimal in a Bayesian fixed-error-probability formulation, as the unit detection delay cost or the misdiagnosis and false alarm probabilities go to zero, respectively. Numerical examples are provided to verify the asymptotic optimality and the speed of convergence.
Optimization of a Six-Strand Continuous Casting Tundish: Industrial Measurements and Numerical Investigation of the Tundish Modifications
Authors: Merder Tomasz , Warzecha Marek
Published: April 2012

The main differences in the transient zone extent between the individual strands for the former industrial six-strand tundish configuration is the basis for undertaking this study. The aim this study was to improve the casting conditions by proposing the optimal equipment of the tundish working space. For economic reasons, only the variants with different baffles configurations were considered. It was also dictated by the simplicity of construction and the possibility of its implementation by the base operating steel mill. In the current study, industrial plant measurements and mathematical modeling were used. Industrial experimental data were used to diagnose the current state of the industrial tundish and then validate the numerical simulations. After this, the influence of different baffle configurations installed in the tundish on the steel flow characteristic was modeled mathematically. Residence time distribution (RTD) curves are plotted, and individual flow shares for the investigated tundish were estimated based on the curves. Finally, the industrial plant was rebuilt according to the numerical results and additional plant measurements were performed. A result of the appearance of the baffles in the tundish working space was the reduction of the transient zone extent. The results indicate the increasing share of the dispersed plug flow and a decreasing share of the dead volume flow, with a practically unchanging share of well-mixed volume flow in the modified tundish.
The effect of diffusion on the dynamics of unsteady detonations
Authors: Romick C. M. , Aslam T. D. , Powers J. M.
Published: April 2012

The dynamics of a one-dimensional detonation predicted by a one-step irreversible Arrhenius kinetic model are investigated in the presence of mass, momentum and energy diffusion. A study is performed in which the activation energy is varied and the length scales of diffusion and reaction are held constant. As the activation energy is increased, the system goes through a series of period-doubling events and eventually undergoes a transition to chaos. The rate at which these bifurcation points converge is calculated and shown to be in agreement with the Feigenbaum constant. Within the chaotic regime, there exist regions in which there are limit cycles consisting of a small number of oscillatory modes. When an appropriately fine grid is used to capture mass, momentum and energy diffusion, predictions are independent of the differencing scheme. Diffusion affects the behaviour of the system by delaying the onset of instability and strongly influencing the dynamics in the unstable regime. The use of the reactive Euler equations to predict detonation dynamics in the unstable and marginally stable regimes is called into question as the selected reactive and diffusive length scales are representative of real physical systems; reactive Navier–Stokes is a more appropriate model in such regimes.
Protective effects of vitamins E, B and C andl-carnitine in the prevention of cisplatin-induced ototoxicity in rats
Authors: Tokgöz S Alıcura , Vuralkan E , Sonbay N D , Çalişkan M , Saka C , Beşalti Ö , Akin İ
Published: April 2012

Objective:

This experimental study aimed to investigate the effects of vitamins E, B and C andl-carnitine in preventing cisplatin-induced ototoxicity.

Methods:

Twenty-five adult, male, Wistar albino rats were randomly allocated to receive intraperitoneal cisplatin either alone or preceded by vitamins B, E or C orl-carnitine. Auditory brainstem response (i.e. hearing thresholds and wave I–IV intervals) and distortion product otoacoustic emissions (i.e. signal-to-noise ratios) were recorded before and 72 hours after cisplatin administration.

Results:

The following statistically significant differences were seen: control group pre-vspost-treatment wave I–IV interval values (p < 0.05); controlvsvitamin E and B groups' I–IV interval values (p < 0.05); controlvsother groups' hearing thresholds; vitamin Evsvitamin B and C andl-carnitine groups' hearing thresholds (p < 0.05); and vitamin Bvsvitamin C andl-carnitine groups' hearing thresholds (p < 0.05). Statistically significant decreases were seen when comparing the initial and final signal-to-noise ratios in the control, vitamin B andl-carnitine groups (2000 and 3000 Hz;p < 0.01), and the initial and final signal-to-noise ratios in the control group (at 4000 Hz;p < 0.01).

Conclusion:

Vitamins B, E and C andl-carnitine appear to reduce cisplatin-induced ototoxicity in rats. The use of such additional treatments to decrease cisplatin-induced ototoxicity in humans is still under discussion.
Trajectories of maternal depressive symptoms predict child problem behaviour: The Generation R Study
Authors: Cents R. A. M. , Diamantopoulou S. , Hudziak J. J. , Jaddoe V. W. V. , Hofman A. , Verhulst F. C. , Lambregtse-van den Berg M. P. , Tiemeier H.
Published: April 2012

Background

It is unclear how the course of maternal depressive symptoms affects child development. We modelled trajectories of maternal depressive symptoms from mid-pregnancy to 3 years after childbirth to better determine their associations with child problem behaviour.

Method

Mother–child dyads (n = 4167) participated in a population-based prospective cohort in The Netherlands. Depressive symptoms were assessed with the Brief Symptom Inventory during pregnancy and at 2, 6 and 36 months postnatally. When children were 3 years old, problem behaviour was assessed with the Child Behaviour Checklist completed by each parent. A group-based modelling technique was used to model trajectories of maternal depressive symptoms and to examine their association with child problem behaviour. The added value of trajectory modelling was determined with successive linear regressions.

Results

We identified four trajectories of maternal depressive symptoms; ‘no’ (34%), ‘low’ (54%), ‘moderate’ (11%) and ‘high’ (1.5%). Child problem behaviour varied as a function of maternal trajectory membership. Whether rated by mother or father, children of mothers assigned to higher trajectories had significantly more problem behaviours than children of mothers assigned to lower trajectories. The model including trajectories had additive predictive value over a model relying only on a summed repeated measure of severity and a predefined chronicity variable.

Conclusions

Depending on their course, maternal depressive symptoms have different effects on child problem behaviour. More information is gained by studying trajectories of symptoms, than only predefined measures of severity and chronicity. Moreover, trajectories can help identifying clinically depressed mothers who are possible candidates for early interventions.
The prospects of deliberative global governance in the G20: legitimacy, accountability, and public contestation
Authors: SLAUGHTER STEVEN
Published: April 2012

This article contends that the ‘G’ system struggles to play a legitimate and effective role in global governance and argues that the G20 could play a important role if the forum was more publically accountable. This article argues that because of increasing forms of public contestation, the broadening agenda of the G8 and G20 and the uncertain status of global cooperation, that the legitimacy of the ‘G’ system is being questioned. As such, it is appropriate to consider deliberative avenues whereby public views could be considered by the G20 in a systematic way to foster forms of accountability. This consideration is animated by deliberative democracy theory and republican theory which advance a normative agenda which seeks to transform governance structures by enhancing the role of deliberation and public reasoning in political life. The article outlines the development of the ‘G’ system's legitimacy, considers possible modes of accountability and public involvement with respect to the G20 and examines the implications of more formalised public deliberation with respect to the G20.
THE CONTRIBUTION OF DIFFERENT INFORMATION SOURCES FOR ADVERSE EFFECTS DATA
Authors: Golder Su , Loke Yoon K.
Published: April 2012

Objectives: The aim of this study is to determine the relative value and contribution of searching different sources to identify adverse effects data.

Methods: The process of updating a systematic review and meta-analysis of thiazolidinedione-related fractures in patients with type 2 diabetes mellitus was used as a case study. For each source searched, a record was made for each relevant reference included in the review noting whether it was retrieved with the search strategy used and whether it was available but not retrieved. The sensitivity, precision, and number needed to read from searching each source and from different combinations of sources were also calculated.

Results: There were 58 relevant references which presented sufficient numerical data to be included in a meta-analysis of fractures and bone mineral density. The highest number of relevant references were retrieved from Science Citation Index (SCI) (35), followed by BIOSIS Previews (27) and EMBASE (24). The precision of the searches varied from 0.88% (Scirus) to 41.67% (CENTRAL). With the search strategies used, the minimum combination of sources required to retrieve all the relevant references was; the GlaxoSmithKline (GSK) website, Science Citation Index (SCI), EMBASE, BIOSIS Previews, British Library Direct, Medscape DrugInfo, handsearching and reference checking, AHFS First, and Thomson Reuters Integrity or Conference Papers Index (CPI).

Conclusions: In order to identify all the relevant references for this case study a number of different sources needed to be searched. The minimum combination of sources required to identify all the relevant references did not include MEDLINE
Spatial construction of European family and household systems: a promising path or a blind alley? An Eastern European perspective
Authors: SZOŁTYSEK MIKOŁAJ
Published: April 2012

This essay represents an attempt at a re-examination of the Western scientific evidence for the existence of the divergent ‘Eastern European family pattern’. This evidence is challenged by almost entirely unknown contributions of Eastern European scholars, revealing the stark incompatibility of the two discourses. This paper is informed to a large extent by Richard Wall's voluminous research on European household and family systems. Wall's original observation of non-negligible spatial variation within the supposedly homogeneous North-Western European marriage and family pattern is used here as a starting point to show the true diversity of familial organisation in Eastern Europe, which had been placed at the other end of the spectrum of what was long believed to be a dichotomous division in European family systems. The diversity of family forms and the rhythms of their development in historical Eastern Europe presented in this literature should finally free us from a simplistic view of the continent's familial history, and especially from the perspective implied by the notion of a ‘dividing line’.
Negligence, greed and the operation of English charities, 1350–1603
Authors: MCINTOSH MARJORIE K.
Published: April 2012

This paper explores the problems that hampered the effective functioning of charitable activities for the English poor during the later medieval years and sixteenth century and examines how the Poor Laws of 1598 and 1601 addressed those issues. It considers four types of challenges stemming from individual negligence or greed as well as the systemic legal obstacles that underlay them. The solutions provided by the Elizabethan Poor Laws placed charitable projects on a more solid legal and administrative footing, facilitating their expansion in the following centuries.
The Ancient Office of Parish Clerk and the Parish Clerks Company of London
Authors: Clark Oswald
Published: April 2012

Attempt is made to trace the work and role of the parish clerk from menial monastic beginnings to its emergence in the thirteenth century as a canonically recognised office–probably the oldest unordained office at the parochial level in the English church and the last vestigial survival of Minor Orders. In parallel is developed the story of the coming together of London parish clerks as a guild or fraternity, radically distinguished from the merchant, craft and service guilds, and of the grant to that fraternity of‘clerici et literati’–with its unique livery and ethos–of the first of its six Royal Charters. The duties and activities of mediaeval parish clerks and the constitution of their Company are considered along with its possessions, especially its Bede Roll. Attention is paid to the understanding of Purgatory and the devastating effects of the Chantries Act 1548. The parish clerk's changing role following the Reformation is examined within the prevailing continuities and discontinuities. New duties in relation to Registration and Bills of Mortality are marked in addition to the parish clerk's increasing social involvement in the civil affairs of the parish. The decline in the parish clerk's duties from the nineteenth century is studied and its effect on the office, the London Company and the ancient parishes of old London, from which the Company is exclusively recruited.
Changes in the distribution and abundance of wintering Lesser White-fronted GeeseAnser erythropusin eastern China
Authors: WANG XIN , FOX ANTHONY D. , CONG PEIHAO , BARTER MARK , CAO LEI
Published: April 2012

The Lesser White-fronted Goose Anser erythropus is globally threatened with an estimated world population of 25,000–28,000, of which c 20,000 winter at East Dongting Lake, China. We present here the first collation of published and unpublished data on the distribution and abundance of the species in eastern China in recent decades. Lesser White-fronted Goose numbers have declined greatly in Anhui, Jiangxi and Jiangsu Provinces between the late-1980s/early-1990s and recent years: the species’ range has now mainly contracted to East Dongting Lake in Hunan. The relatively stable numbers at East Dongting Lake suggest that the population is not currently threatened, but the extreme concentration at one lake makes the species vulnerable. Lesser White-fronted Geese rely on very specific meadow vegetation exposed after water recession, so changes in water levels or recession timing, due to hydrological changes following the commissioning of the Three Gorges Dam, may affect biomass, palatability and plant species composition of the meadows. Thus, it is critically important to understand the wintering ecology and habitat needs of this threatened species at East Dongting Lake. It is also essential to conduct further synchronous Yangtze River floodplain surveys to assess the current status, distribution and habitat use of Lesser White-fronted Geese throughout the region.
Mental Retrieval of Treatment Context in Dental Phobia
Authors: Elsesser Karin , Wannemüller Andre , Lohrmann Thomas , Jöhren Peter , Sartory Gudrun
Published: April 2012

Background: The effect of mental retrieval of an exposure session was investigated during a follow-up examination in dental phobia patients. Method: The exposure session took place at the psychology unit and the follow-up a week later at the dental clinic prior to dental treatment while patients were seated in the dental chair. During exposure, individuals with dental phobia (N = 72) were shown a video of a dental appointment, after which they were instructed to imagine themselves receiving dental treatment. During follow-up half of the participants received instructions to mentally retrieve the exposure session and the other half were asked to recall everyday activities. Before and after exposure treatment, and after mental retrieval, participants were shown three dental instruments while heart rate (HR) and avoidance and subjective units of discomfort (SUD) were recorded. Results: Questionnaires of phobic anxiety administered before and after treatment indicated significant improvement. Mental retrieval of treatment was moderately superior to the control condition with regard to avoidance. Over 80% of patients underwent the subsequent dental treatment session. Those not adhering showed initially more dysfunctional cognitions and more desire for control. Conclusion: There is some evidence that retrieval of treatment context may have a moderately beneficial effect on avoidance.
No increased risk of psychological/behavioral disorders in siblings of women with hyperemesis gravidarum (HG) unless their mother had HG
Authors: Mullin P. M. , Bray A. , Vu V. , Schoenberg-Paik F. , MacGibbon K. , Romero R. , Goodwin T. M. , Fejzo M. S.
Published: April 2012

Hyperemesis gravidarum (HG), severe nausea and vomiting of pregnancy, is characterized by prolonged maternal stress, undernutrition and dehydration. Maternal stress and malnutrition of pregnancy are linked to poor neonatal outcome and associated with poor adult health, and we recently showed that in utero exposure to HG may lead to increased risks of psychological and behavioral disorders in the offspring. In addition, we have shown familial aggregation of HG, which is strong evidence for a genetic component to the disease. In this study, we compare the rates of psychological and behavioral disorders in 172 adults with and 101 adults without a sibling with HG. The rate of emotional/behavioral disorders is identical (15%) in both groups. The results suggest that the etiology of HG is not likely to include genetic factors associated with emotional and behavioral disorders. In addition, this study provides evidence that the increased incidence of psychological/behavioral disorders among offspring of women with HG is attributable to the HG pregnancy itself, rather than to confounding genetic factors linked to HG.
Area characteristics and admission rates of people with schizophrenia and affective disorders in a German rural catchment area
Authors: Losert C. , Schmauß M. , Becker T. , Kilian R.
Published: April 2012

Background.

Studies in urban areas identified environmental risk factors for mental illness, but little research on this topic has been performed in rural areas.

Methods.

Hospital admission rates were computed for 174 rural municipalities in the catchment area of the state psychiatric hospital in Günzburg in years 2006 to 2009 and combined with structural and socio-economic data. Relationships of overall and diagnosis-specific admission rates with municipality characteristics were analysed by means of negative binomial regression models.

Results.

Admission rates of patients with a diagnosis of schizophrenia and affective disorder combined decrease with increasing population growth, population density, average income and green areas, while admission rates are positively correlated with commuter balance, income inequality, unemployment rates and traffic areas. Admission rates for schizophrenia are negatively related to population growth, average income and agricultural areas, but positively related to mobility index, income inequality and unemployment rate. Admission rates for affective disorders are negatively related to population growth, population density, average income and green areas, while higher admission rates are correlated with commuter balance, high income inequality, unemployment rate and traffic-related areas.

Conclusions.

Effects of wealth, economic inequality, population density and structural area characteristics influence psychiatric admission rates also in rural areas.
Entropy conservation and rate of propagation of bubbles in the Earth's magnetotail: A case study
Authors: Sanchez Ennio R. , Wing Simon , Spanswick Emma , Donovan Eric
Published: April 2012

Earthward propagation of low‐density flux tubes, called “plasma bubbles,” is a candidate mechanism to reduce total entropy in the plasma sheet. MHD models predict that bubbles conserve total entropy (S) as they propagate earthward, that the amount of density depletion governs the speed of propagation, and that bubbles slow down as their S nears the ambient plasma sheet S. The main objective of the present study is to test these predictions. Multiple instances of bursty flows with low entropy content were analyzed using in situ and all‐sky observations during a major THEMIS (TH) alignment. Twelve bubbles identified at TH‐B altitude were tracked earthward to determine if they convected past TH‐C, ‐D or ‐E and TH‐A. The analysis shows that the mean plasma sheet S along the THEMIS alignment is not conserved in general, as it decreases with decreasing distance. However, S is nearly constant along the bubbles' trajectories. Furthermore, S of the bubbles is one standard deviation smaller than the mean ambient plasma sheet S. Therefore, bubbles tend to decrease the S of the plasma sheet. An inverse relation of density and S of bubbles with velocity is consistent with theoretical predictions. The mean specific entropy (s) of the bubbles tends to be one standard deviation larger than the mean plasma sheet s. Therefore, bubbles tend to increase the plasma sheet s. A DMSP‐THEMIS coincidence during the sampled period shows how plasma measurements from low‐orbiting satellites combined with all‐sky images can be used to track the propagation of bubbles.
Goniopolarimetric inversion using SVD: An application to type III radio bursts observed by STEREO
Authors: Krupar V. , Santolik O. , Cecconi B. , Maksimovic M. , Bonnin X. , Panchenko M. , Zaslavsky A.
Published: April 2012

Type III radio bursts are intense solar radio emissions generated by beams of energetic electrons injected into the interplanetary medium. They can be routinely observed by the S/Waves instruments on‐board the STEREO (Solar Terrestrial Relation Observatory) spacecraft. We describe goniopolarimetric (GP) inversion of a signal measured on non‐orthogonal antennas using the Singular Value Decomposition (SVD) technique. This wave propagation analysis can be applied to spectral matrices built from measurements by the High Frequency Receiver (HFR; a part of the S/Waves experiment). We have found an empirical relation between the decomposed spectral matrices and apparent source sizes for waves with a low degree of polarization. Simulations of electromagnetic emissions with various senses and degrees of polarization, and source shapes show that SVD gives us reasonable results with respect to the polarization ellipsoid geometry. An error analysis considering inaccuracies of HFR has been performed in order to test the validity of the k‐vector direction estimation and the obtained empirical relation. We present a joint observation of a type III radio burst by the STEREO and Wind spacecraft during small separation distances. We obtain consistent results for the k‐vector direction and apparent source size using different analysis methods for the measurements of the STEREO and Wind spacecraft. We demonstrate that SVD can be an effective tool for the wave analysis of radio emissions measured on non‐orthogonal antennas even with very extended sources.
Geodetic observations detecting coseismic displacements and gravity changes caused by the Mw = 9.0 Tohoku‐Oki earthquake
Authors: Zhou Xin , Sun Wenke , Zhao Bin , Fu Guangyu , Dong Jie , Nie Zhaosheng
Published: April 2012

This paper reports coseismic displacements and gravity changes caused by the Tohoku‐Oki earthquake (Mw 9.0), as observed respectively using GPS in Japan and China and its surrounding area, and as observed by GRACE. To interpret geodetic observation data, we must choose a reasonable model among the slip models presented for the event. For this purpose, we first calculated the displacements using three slip models from USGS, UCSB, and ARIA respectively, with different dislocation theories. Then we compared the results with the displacements observed in Japan and China. Results show that the modeled coseismic displacements calculated using the slip model of Wei et al. (ARIA) and the spherically layered dislocation theory under the PREM model agree well with the observed ones, indicating that the Earth's layer‐structural and curvature effects should be considered. Then, we computed the coseismic geoid and gravity changes on the earth surface and at a space‐fixed point using the three slip models and the spherically layered dislocation theory. Results show that the maximum coseismic geoid change reaches 2.5 cm and that the coseismic gravity changes are about −1000–600 μgal for a solid Earth. Furthermore, we processed GRACE data to extract coseismic changes with decorrelation and a Gaussian filter of 350 km. The gravity changes observed by GRACE were dominated by a decrease over the back‐arc region, with −5 μgal reflecting coseismic crustal dilatation of the landward plate, which agrees well with the theoretically modeled values from the three finite fault models. After the 2004 Sumatra–Andaman and 2010 Central Chile (Maule) earthquakes, this study presents the third case of clear detection of coseismic gravity changes by GRACE.
The 2007 M7.7 Tocopilla northern Chile earthquake sequence: Implications for along‐strike and downdip rupture segmentation and megathrust frictional behavior
Authors: Schurr B. , Asch G. , Rosenau M. , Wang R. , Oncken O. , Barrientos S. , Salazar P. , Vilotte J.‐P.
Published: April 2012

In 2007 a M7.7 earthquake occurred near the town of Tocopilla within the northern Chile seismic gap. Main shock slip, derived from coseismic surface deformation, was confined to the depth range between 30 and 55 km. We relocated ∼1100 events during six months before and one week after the main shock. Aftershock seismicity is first congruent to the main shock slip and then it spreads offshore west and northwest of Mejillones Peninsula (MP). Waveform modeling for 38 aftershocks reveals source mechanisms that are in the majority similar to the main shock. However, a few events appear to occur in the upper plate, some with extensional mechanisms. Juxtaposing the Tocopilla aftershocks with those following the neighboring 1995 Antofagasta earthquake produces a striking symmetry across an EW axis in the center of MP. Events seem to skirt around MP, probably due to a shallower Moho there. We suggest that the seismogenic coupling zone in northern Chile changes its frictional behavior in the downdip direction from unstable to mostly conditionally stable. For both earthquake sequences, aftershocks agglomerate in the conditionally stable region, whereas maximum inter‐seismic slip deficit and co‐seismic slip occurs in the unstable region. The boundary between the unstable and conditionally stable zones parallels the coastline. We identify a similar segmentation for other earthquakes in Chile and Peru, where the offshore segments break in great M > 8 earthquakes, and the onshore segments in smaller M < 8 earthquakes. Using critical taper analysis, we demonstrate a causal relationship between varying slip behavior on the interface and forearc wedge anatomy that can be attributed to spatial variations in the rate‐dependency of friction.
Observations of internal waves and parametric subharmonic instability in the Philippines archipelago
Authors: Chinn Brian S. , Girton James B. , Alford Matthew H.
Published: April 2012

Internal waves contain a significant fraction of the kinetic energy in the ocean and are important intermediaries between the forcing (by wind and tide) and interior diapycnal mixing. We report here on measurements from Mindoro Strait in the Philippines (connecting the South China Sea to the Sulu Sea) of an internal wave field with a number of surprising properties that point to previously‐unrecognized processes at work in the region. Continuum spectral levels are very close to typical “background” values found in the open ocean, but internal tide energy in both the diurnal and semidiurnal frequency bands is significantly elevated—and higher at the northern mooring (MP1) than the southern (MP2). Two particularly energetic depth ranges stand out at MP1: an upper layer centered near 300 m, and one at the bottom of the water column, near 1800 m. The upper layer contains both internal tides and a near‐inertial band with upward and downward propagating waves and an apparent spring‐neap cycle. The combination is suggestive of Parametric Subharmonic Instability as the forcing for the near‐inertial band—a conclusion supported by bicoherence estimates. Mixing, estimated from density overturns, is weak over much of the water column but enhanced by about an order of magnitude in the deep layer and closely tied to the internal tide—both diurnal and semidiurnal. Near‐inertial currents in this deep layer are dominantly rectilinear and not well‐correlated with the mixing. Bulk mixing rates at the two sites are less than required to produce property changes seen in hydrography, suggesting additional enhancement elsewhere in the archipelago.
Wind and temperature response of midlatitude mesopause region to the 2009 Sudden Stratospheric Warming
Authors: Yuan Tao , Thurairajah B. , She C.‐Y. , Chandran A. , Collins R. L. , Krueger D. A.
Published: April 2012

In this paper we report winds and temperature in the mesopause region (80–102 km) over full diurnal cycles during the 2009 major Sudden Stratospheric Warming (SSW) at Fort Collins (41°N, 105°W). The measurements were made with the Colorado State University (CSU) sodium Doppler wind‐temperature lidar. We deduce the diurnal mean wind and temperature profiles by removing the tidal components from the 24‐h continuous observations and present their anomalous behaviors in connection with this event. These mean wind and temperature measurements reveal significant anomalies in the mesopause region: the mean temperature at 80 km was approximately 30 K lower than the climatological mean; the mean zonal wind ranged between ∼ −10 to 0 m/s from 80 to 97 km and then turned eastward in lower thermosphere in a reversal of the climatological mean wind profile. We further use observations from the TIMED/SABER satellite observations and simulations from the WACCM model to investigate the global structure of this dynamical anomaly at Fort Collins. The satellite observations and model reveal that the anomaly is part of a disturbance that extended from the polar region to Fort Collins. These simultaneous wind‐ and temperature‐lidar observations document the direct impact of a major SSW on the dynamic and thermal circulation of the midlatitude mesopause region.
The m‐chi decomposition of hybrid dual‐polarimetric radar data with application to lunar craters
Authors: Raney R. Keith , Cahill Joshua T. S. , Patterson G. Wesley , Bussey D. Benjamin J.
Published: April 2012

We introduce a new technique derived from the classical Stokes parameters for analysis of polarimetric radar astronomical data. This decomposition is based on m (the degree of polarization) and chi (the Poincaré ellipticity parameter). Analysis of the crater Byrgius A demonstrates how m‐chi can more easily differentiate materials within ejecta deposits and their relative thicknesses. We use Goldschmidt crater to demonstrate how m‐chi can differentiate coherent deposits of water ice. Goldschmidt crater floor is found to be consistent with single bounce Bragg scattering suggesting the absence of water ice and further corroborating adsorbed H to mineral grains or an H2O frost as plausible explanations for a H2O/OH detection by near‐infrared instruments.
Alpine inversion of the North African margin and delamination of its continental lithosphere
Authors: Roure François , Casero Piero , Addoum Belkacem
Published: April 2012

This paper aims at summarizing the current extent and architecture of the former Mesozoic passive margin of North Africa from North Algeria in the west up to the Ionian‐Calabrian arc and adjacent Mediterranean Ridge in the east. Despite that most paleogeographic models consider that the Eastern Mediterranean Basin as a whole is still underlain by remnants of the Permo‐Triassic or a younger Cretaceous Tethyan‐Mesogean ocean, the strong similarities documented here in structural styles and timing of inversion between the Saharan Atlas, Sicilian Channel and the Ionian abyssal plain evidence that this portion of the Eastern Mediterranean Basin still belongs to the distal portion of the North African continental margin. A rim of Tethyan ophiolitic units can be also traced more or less continuously from Turkey and Cyprus in the east, in onshore Crete, in the Pindos in Greece and Mirdita in Albania, as well as in the Western Alps, Corsica and the Southern Apennines in the west, supporting the hypothesis that both the Apulia/Adriatic domain and the Eastern Mediterranean Basin still belong to the former southern continental margin of the Tethys. Because there is no clear evidence of crustal‐scale fault offsetting the Moho, but more likely a continuous yet folded Moho extending between the foreland and the hinterland beneath the Mediterranean arcs, we propose here a new model of delamination of the continental lithosphere for the Apennines and the Aegean arcs. In this model, only the mantle lithosphere of Apulia and the Eastern Mediterranean is still locally subducted and recycled in the asthenosphere, most if not all the northern portion of the African crust and coeval Moho being currently decoupled from its former, currently delaminated and subducted mantle lithosphere.
Uplift history of the Sila Massif, southern Italy, deciphered from cosmogenic 10Be erosion rates and river longitudinal profile analysis
Authors: Olivetti Valerio , Cyr Andrew J. , Molin Paola , Faccenna Claudio , Granger Darryl E.
Published: April 2012

The Sila Massif in the Calabrian Arc (southern Italy) is a key site to study the response of a landscape to rock uplift. Here an uplift rate of ∼1 mm/yr has imparted a deep imprint on the Sila landscape recorded by a high‐standing low‐relief surface on top of the massif, deeply incised fluvial valleys along its flanks, and flights of marine terraces in the coastal belt. In this framework, we combined river longitudinal profile analysis with hillslope erosion rates calculated by 10Be content in modern fluvial sediments to reconstruct the long‐term uplift history of the massif. Cosmogenic data show a large variation in erosion rates, marking two main domains. The samples collected in the high‐standing low‐relief surface atop Sila provide low erosion rates (from 0.09 ± 0.01 to 0.13 ± 0.01 mm/yr). Conversely, high values of erosion rate (up to 0.92 ± 0.08 mm/yr) characterize the incised fluvial valleys on the massif flanks. The analyzed river profiles exhibit a wide range of shapes diverging from the commonly accepted equilibrium concave‐up form. Generally, the studied river profiles show two or, more frequently, three concave‐up segments bounded by knickpoints and characterized by different values of concavity and steepness indices. The wide variation in cosmogenic erosion rates and the non‐equilibrated river profiles indicate that the Sila landscape is in a transient state of disequilibrium in response to a strong and unsteady uplift not yet counterbalanced by erosion.
Increases in aerosol concentrations over eastern China due to the decadal‐scale weakening of the East Asian summer monsoon
Authors: Zhu Jianlei , Liao Hong , Li Jianping
Published: April 2012

China has been experiencing increased concentrations of aerosols, commonly attributed to the large increases in emissions associated with the rapid economic development. We show by using a chemical transport model driven by the assimilated meteorological fields that the observed decadal‐scale weakening of the East Asian summer monsoon also contributed to the increases in aerosols in China. We find that the simulated aerosol concentrations have strong negative correlations with the strength of the East Asian Summer monsoon. Accounting for sulfate, nitrate, ammonium, black carbon, and organic carbon aerosols, the summer surface‐layer PM2.5 concentration averaged over eastern China (110°–125°E, 20°–45°N) can be 17.7% higher in the weakest monsoon years than in the strongest monsoon years. The weakening of the East Asian Summer monsoon increases aerosol concentrations mainly by the changes in atmospheric circulation (the convergence of air pollutants) in eastern China.
Cassini in Titan's tail: CAPS observations of plasma escape
Authors: Coates A. J. , Wellbrock A. , Lewis G. R. , Arridge C. S. , Crary F. J. , Young D. T. , Thomsen M. F. , Reisenfeld D. B. , Sittler E. C. , Johnson R. E. , Szego K. , Bebesi Z. , Jones G. H.
Published: April 2012

We present observations of CAPS electron and ion spectra during Titan distant tail crossings at 5,000–10,000 km altitude by the Cassini spacecraft. In common with closer tail encounters, we identify ionospheric plasma in the tail. Some of the electron spectra indicate a direct magnetic connection to Titan's dayside ionosphere due to the presence of ionospheric photoelectrons. Ion observations reveal heavy (m/q∼ 16 and 28) and light (m/q = 1–2) ion populations streaming into the tail. Using the distant tail encounters T9, T75 and T63, we estimate total plasma loss rates from Titan via this process of (4.2, 0.96 and 2.3) × 1024 ions s−1 respectively for the three encounters, values which are in agreement with some simulations but slightly lower than earlier estimates based on non‐differential techniques. Using the mass‐separated data, this corresponds to mass loss rates of (8.9, 1.6, 4.0) × 1025 amu s−1 for T9, T75 and T63 respectively, an average loss rate of ∼7 tonnes per Earth day. Remarkably, all of the tail encounters studied here indicate a split tail feature, indicating that this may be a common feature in Titan's interaction with Saturn's magnetosphere.
Evaluating the “critical relative humidity” as a measure of subgrid‐scale variability of humidity in general circulation model cloud cover parameterizations using satellite data
Authors: Quaas Johannes
Published: April 2012

A simple way to diagnose fractional cloud cover in general circulation models is to relate it to the simulated relative humidity, and allowing for fractional cloud cover above a “critical relative humidity” of less than 100%. In the formulation chosen here, this is equivalent to assuming a uniform “top‐hat” distribution of subgrid‐scale total water content with a variance related to saturation. Critical relative humidity has frequently been treated as a “tunable” constant, yet it is an observable. Here, this parameter, and its spatial distribution, is examined from Atmospheric Infrared Sounder (AIRS) satellite retrievals, and from a combination of relative humidity from the ECMWF Re‐Analyses (ERA‐Interim) and cloud fraction obtained from CALIPSO lidar satellite data. These observational data are used to evaluate results from different simulations with the ECHAM general circulation model (GCM). In sensitivity studies, a cloud feedback parameter is analyzed from simulations applying the original parameter choice, and applying parameter choices guided by the satellite data. Model sensitivity studies applying parameters adjusted to match the observations show larger positive cloud‐climate feedbacks, increasing by up to 30% compared to the standard simulation.
Efficient photocatalytic hydrogen evolution over hydrogenated ZnO nanorod arrays
Authors: Lu Xihong , Wang Gongming , Xie Shilei , Shi Jianying , Li Wei , Tong Yexiang , Li Yat
Published: April 2012

Hydrogenated ZnO nanorod arrays grown on FTO substrates yield a benchmark specific hydrogen production rate of 122 500 μmol h−1 g−1.