bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of silence and attention on tinnitus perception
Authors: Knobel Keila Alessandra Baraldi , Sanchez Tanit Ganz
Published: September 2008

Objective

The purpose of this study was to study the effect of attention and sustained silence on the emergence of auditory phantom perception in normal‐hearing adults.

Study Design

Cross‐sectional survey.

Subjects and Methods

While sitting in a sound booth, 66 volunteers (age range, 18–65; mean age, 37.3) performed 3 experiments of 5 minutes each, consecutively and randomly presented. Two deviated attention from auditory system (Hanoi and visual attention experiments), and 1 drove attention to the auditory system (auditory attention). After each experiment, participants were asked about their auditory and visual perception. No sound or light change was given at any moment.

Results

Of the participants, 19.7% experienced tinnitus during Hanoi, 45.5% during visual attention, and 68.2% during auditory attention experiment, with no significant differences for studied variables.

Conclusion

Tinnitus‐like perceptions may occur in a non‐clinical population in a silent environment. Concomitant auditory attention plays an important role on the emergence of tinnitus.
Bones and words in 1870s New Zealand: the moa-hunter debate through actor networks
Authors: THODE SIMON
Published: September 2008

The paper describes an episode in New Zealand science commonly referred to as the moa-hunter debate. In the 1870s the geologist and curator of the Canterbury Museum Julius Haast put forward a proposal that a race distinct from the indigenous Maori hunted the giant flightless birds known as moa to extinction. James Hector, director of the New Zealand Geological Survey and manager of the New Zealand Institute, rejected this proposal and challenged Haast in what would become a bitter fight. Because moa remains in the form of semi-fossilized bones, eggshells and occasionally preserved feathers and skin were important in the debate, the paper will use the analytical method of actor-network theory (ANT) to reopen it. The paper thus provides an opportunity to study the strengths and weaknesses of ANT as a form of analysis. This analysis emphasizes a number of interesting points about the moa-hunter debate, including the ability of human actors to manipulate the meaning of common terms in order to create new theories, in this case Haast's theory of an earlier indigenous race in New Zealand. Though dismissed at the time, this was a belief that has lasted in alternative forms to the present.
Advertising cadavers in the republic of letters: anatomical publications in the early modern Netherlands
Authors: MARGÓCSY DÁNIEL
Published: September 2008

This paper sketches how late seventeenth-century Dutch anatomists used printed publications to advertise their anatomical preparations, inventions and instructional technologies to an international clientele. It focuses on anatomists Frederik Ruysch (1638–1732) and Lodewijk de Bils (1624–69), inventors of two separate anatomical preparation methods for preserving cadavers and body parts in a lifelike state for decades or centuries. Ruysch's and de Bils's publications functioned as an ‘advertisement’ for their preparations. These printed volumes informed potential customers that anatomical preparations were aesthetically pleasing and scientifically important but did not divulge the trade secrets of the method of production. Thanks to this strategy of non-disclosure and advertisement, de Bils and Ruysch could create a well-working monopoly market of anatomical preparations. The ‘advertising’ rhetorics of anatomical publications highlight the potential dangers of equating the growth of print culture with the development of an open system of knowledge exchange.
Effects ofn-3 fatty acids and acute exercise on endothelium-dependent vasorelaxation in healthy rat aorta
Authors: Thioub Sanéo , Mansourati Jacques , Corporeau Charlotte , Heylen Erwan , Delarue Jacques , Guerrero François
Published: September 2008

The purpose of this study was to determine whethern-3 PUFA result in an effect on endothelial function that is in addition to that of acute exercise. For 4 weeks, male Sprague–Dawley rats were subjected to a diet based onn-3 PUFA or a standard diet. In each diet group, ten rats were submitted to an acute treadmill exercise while the remaining ten acted as sedentary controls. The running speed was progressively increased until the animals were exhausted. Endothelial function was then assessed by measuring isometric tension in rings of the thoracic aorta. In vessels precontracted with 0·1 μm-phenylephrine, responses to acetylcholine (ACh) were significantly improved following acute exercise in all diet groups. When PUFA supplementation was compared to the standard diet no significant difference was found in response to ACh, either at rest or after an acute exercise. Pretreatment of rings with Nω-nitro-l-arginine methyl esther (50 μm) inhibited the ACh-mediated vasorelaxation in all groups. Response to 10 μm-nifedipine, an L-type Ca2+channel antagonist, was similarly enhanced after acute exercise in both standard and PUFA diets. Furthermore, response to 0·01 μm-nifedipine was significantly higher after acute exercise only in the PUFA diet. In conclusion, in our ‘healthy’ rat model with ‘normal’ baseline endothelial function, acute exercise improves response to ACh while PUFA supplementation alone or in combination with acute exercise has no effect on endothelium-dependent vasorelaxation. However, PUFA may potentiate the acute exercise effect on smooth muscle cell relaxation via L-type Ca2+channel modifications.
Impact of energy deficit calculated by a predictive method on outcome in medical patients requiring prolonged acute mechanical ventilation
Authors: Faisy Christophe , Lerolle Nicolas , Dachraoui Fahmi , Savard Jean-François , Abboud Imad , Tadie Jean-Marc , Fagon Jean-Yves
Published: September 2008

To assess energy balance in very sick medical patients requiring prolonged acute mechanical ventilation and its possible impact on outcome, we conducted an observational study of the first 14 d of intensive care unit (ICU) stay in thirty-eight consecutive adult patients intubated at least 7 d. Exclusive enteral nutrition (EN) was started within 24 h of ICU admission and progressively increased, in absence of gastrointestinal intolerance, to the recommended energy of 125·5 kJ/kg per d. Calculated energy balance was defined as energy delivered − resting energy expenditure estimated by a predictive method based on static and dynamic biometric parameters. Mean energy balance was − 5439 (sem222) kJ per d. EN was interrupted 23 % of the time and situations limiting feeding administration reached 64 % of survey time. ICU mortality was 72 %. Non-survivors had higher mean energy deficit than ICU survivors (P = 0·004). Multivariate analysis identified mean energy deficit as independently associated with ICU death (P = 0·02). Higher ICU mortality was observed with higher energy deficit (P = 0·003 comparing quartiles). Using receiver operating characteristic curve analysis, the best deficit threshold for predicting ICU mortality was 5021 kJ per d. Kaplan–Meier analysis showed that patients with mean energy deficit ≧5021 kJ per d had a higher ICU mortality rate than patients with lower mean energy deficit after the 14th ICU day (P = 0·01). The study suggests that large negative energy balance seems to be an independent determinant of ICU mortality in a very sick medical population requiring prolonged acute mechanical ventilation, especially when energy deficit exceeds 5021 kJ per d.
Dose-dependent effects of walnuts on motor and cognitive function in aged rats
Authors: Willis Lauren M. , Shukitt-Hale Barbara , Cheng Vivian , Joseph James A.
Published: September 2008

Aged rats show decrements in performance on motor and cognitive tasks that require the use of spatial learning and memory. Previously we have shown that these deficits can be reversed by the polyphenolics in fruits and vegetables. Walnuts, which contain the n-3 fatty acids α-linolenic acid and linoleic acid, are a dietary source of polyphenols, antioxidants and lipids. Thus, the present study examined the effects of walnut supplementation on motor and cognitive ability in aged rats. Fischer 344 rats, aged 19 months, were fed a control, or a 2, 6 or 9 % walnut diet for 8 weeks before motor and cognitive testing. Results for the motor testing showed that the 2 % walnut diet improved performance on rod walking, while the 6 % walnut diet improved performance on the medium plank walk; the higher dose of the 9 % walnut diet did not improve psychomotor performance and on the large plank actually impaired performance. All of the walnut diets improved working memory in the Morris water maze, although the 9 % diet showed impaired reference memory. These findings show for the first time that moderate dietary walnut supplementation can improve cognitive and motor performance in aged rats.
Travertine deposits from along the South Tibetan Fault System near Nyalam, Tibet
Authors: ZENTMYER R. , MYROW P. M. , NEWELL D. L.
Published: September 2008

A newly investigated travertine deposit in southern Tibet provides a window into Holocene hydrological, geomorphic and climatic processes near the boundary of the Tibetan Plateau and High Himalaya. Travertine, deposited as a result of the degassing of CO2-rich groundwater as it emerges on the Earth's surface, is in many cases formed along the trace of major crustal-scale faults in primarily extensional tectonic regimes. A travertine platform measuring roughly 1 km by 0.5 km exists near the town of Nyalam in southern Tibet along a major Himalayan down-to-the-N normal fault, the South Tibetan Fault System. A wide variety of travertine depositional textures and features are recorded in the platform on a series of terraces. Active travertine deposition was observed from spring mounds and seeps along the base of the platform at the modern river level. Palaeotemperatures of spring water, calculated from δ18O of the travertine, range from 9 to 25 °C, which closely matches the temperatures recorded from modern springs in the area. A complex geomorphological landscape records interaction between growing alluvial fans, travertine accumulation, and a rapidly down-cutting river with associated fluvial terraces. River incision was contemporaneous with travertine deposition, as indicated by cemented fluvial river gravel layers interbedded with travertine. High 87Sr/86Sr ratios in the travertine (mean of 0.7168) indicate subsurface fluid interaction with radiogenic crystalline rocks of the underlying Greater Himalaya. Uranium-series ages of the travertine platform range from 5400 a (±950 a) to 11600 a (±1000 a), and indicate a younging progression from higher terraces near the valley wall to lower terraces at present-day river level. Travertine that overlies a river gravel terrace 18 m above river level formed at 11600 a. This date yields a local incision rate of 1.6 mm a−1, consistent with estimated fluvial incision rates in the High Himalaya. The range of our U-series ages coincides with an interval of higher precipitation associated with greater intensity of the Indian monsoon, which led to elevated spring discharge and carbonate precipitation in this part of the High Himalayas.
Patterns of extinction and recovery of phacopid trilobites during the Frasnian–Famennian (Late Devonian) mass extinction event, Canning Basin, Western Australia
Authors: FEIST RAIMUND , MCNAMARA KENNETH J. , CRÔNIER CATHERINE , LEROSEY-AUBRIL RUDY
Published: September 2008

A diverse fauna of phacopid trilobites is described from the Late Devonian (middle Frasnian to early Famennian) of the northern Canning Basin, Western Australia. One new genus and four species in two genera are described from zones 11, 13a and 13b of the middle and late Frasnian:Trimerocephaloides sinevisusgen. nov. and sp. nov.,T.?linguiformissp. nov.,Acuticryphops acuticeps(Kayser, 1889) andA. klapperisp. nov. Late Frasnian phacopines are either blind, as shown for the first time inTrimerocephaloides sinevisus, or show trends to decreasing eye size up to the Frasnian–Famennian ‘Kellwasser’ mass extinction event. This evolutionary trend inAcuticryphopsis demonstrated to have been global at this time. One new genus and six species of early Famennian phacopids are described, from the Uppertriangularis, crepidaandrhomboideazones:Houseopsgen. nov. with the new taxaH. canningensissp. nov.,H. beckerisp. nov. andH.sp. A,Babinops planiventerFeist & Becker, 1997,B. minorsp. nov.,Trimerocephalus tardispinosusFeist & Becker, 1997 andT. mimbisp. nov. In contrast to European sections where exclusively blind phacopids are known in earliest Famennian sites, initial recovery following the mass extinction event in Canning peri-reefal environments is characterized by oculated forms. These trilobites must have evolved from conservative ancestors with normal eyes that had succeeded in surviving the Kellwasser biocrises in reef-related shallow water niches. Thus the origin of post-event phacopids from shallow water environments is demonstrated for the first time. Descendant lineages show increasing eye size, increased cephalic vaulting and effacement during the early Famennian.
Comparing Indonesia's party systems of the 1950s and the post-Suharto era: From centrifugal to centripetal inter-party competition
Authors: Mietzner Marcus
Published: September 2008

This article compares Indonesia's party systems of the 1950s and the post-Suharto period. It explores the question of why the party system of the 1950s collapsed quickly, while that of the contemporary polity appears stable. Challenging established assumptions that party systems fail if their individual parties are weakly institutionalised, I submit that the fundamental difference between the party politics of the 1950s and today's democratic system is related to the character of inter-party competition in both periods. While inter-party contestation in the 1950s took place at the far ends of the politico-ideological spectrum, the competition between parties in the contemporary democracy exhibits centripetal tendencies, stabilising the political system as a whole.
The Ethnography of failure: Middle-class Malays producing capitalism in an ‘Asian miracle’ economy
Authors: Sloane-White Patricia
Published: September 2008

Since NEP, the ethno-political measure of Malay progress has emphasised Malay capital ownership, leading social scientists who study the Malay middle class to focus almost exclusively on what this article calls the ‘two poles of consumption and dependency’. This ethnography suggests that certain middle-class Malays use a different calculus to mark out their place in contemporary Malay life. It argues that these Malays portray themselves not only in terms of material and entrepreneurial success, but through their frequent experiences of failure. To them, failure becomes, paradoxically, a virtue that can establish their moral and Islamic distance from the Malays they characterise as the ‘indolent’ poor and the ‘politicking’ rich.
The anthomedusan fauna of the Japan Trench: preliminary results fromin situsurveys with manned and unmanned vehicles
Authors: Lindsay Dhugal , Pagès Francesc , Corbera Jordi , Miyake Hiroshi , Hunt James C. , Ichikawa Tadafumi , Segawa Kyohei , Yoshida Hiroshi
Published: September 2008

Modernin situsurvey technologies such as crewed submersibles, remotely-operated vehicles (ROVs), towed camera arrays, and visual/video plankton recorders (VPRs) were used to characterize the dominant anthomedusan species off the eastern seaboard of Japan. Notes on the taxonomy, distribution, behaviour and interspecies interactions are presented for the four observed species:Euphysa japonica, E. flammea, Calycopsis nematophoraandPandea rubra. A new generic definition for the genusCalycopsisis proposed. The possibility of run-on, cascading detrimental effects of oceanic acidification on midwater ecosystems was identified from observations made during the present study.
Distribution, extent of inter-annual variability and diet of the bloom-forming jellyfish Rhizostoma in European waters
Authors: Lilley M.K.S. , Houghton J.D.R. , Hays G.C.
Published: September 2008

Jellyfish (Cnidaria: Scyphozoa) are increasingly thought to play a number of important ecosystem roles, but often fundamental knowledge of their distribution, seasonality and inter-annual variability is lacking. Bloom forming species, due to their high densities, can have particularly intense trophic and socio-economic impacts. In northern Europe it is known that one particularly large (up to 30 kg wet weight) bloom forming jellyfish is Rhizostoma spp. Given the potential importance, we set out to review all known records from peer-reviewed and broader public literature of the jellyfish R. octopus (Linnaeus) and R. pulmo (Macri) (Scyphozoa: Rhizostomae) across western Europe. These data revealed distinct hotspots where regular Rhizostoma spp. aggregations appeared to form, with other sites characterized by occasional abundances and a widespread distribution of infrequent observations. Surveys of known R. octopus hotspots around the Irish Sea also revealed marked inter-annual variation with particularly high abundances forming during 2003. The location of such consistent aggregations and inter-annual variances are discussed in relation to physical, climatic and dietary variations.
The prosodic (re)organization of children's early English articles
Authors: DEMUTH KATHERINE , McCULLOUGH ELIZABETH
Published: September 2008

Researchers have long been puzzled by children's variable omission of grammatical morphemes, often attributing this to a lack of semantic or syntactic competence. Recent studies suggest that some of this variability may be due to phonological constraints. This paper explored this issue further by conducting a longitudinal study of five English-speaking one- to two-year-olds' acquisition of articles. It found that most children were more likely to produce articles when these could be produced as part of a disyllabic foot. However, acoustic analysis revealed that one child initially produced all articles as independent prosodic words. These findings confirm that some of the variable production of articles is conditioned by constraints on children's early phonologies, providing further support for the Prosodic Licensing Hypothesis. They also hold important implications for our understanding of the emergence of syntactic knowledge.
CBT Supervision: From Reflexivity to Specialization
Authors: Milne Derek
Published: September 2008

Cognitive-behavioural therapy (CBT) supervision has traditionally been presented as an extension of the therapy, a reflexive strategy that includes a commendable commitment to a principled approach. However, a critical review suggests that this strategy has not been implemented with fidelity. Furthermore, this strategy overlooks potentially valuable ideas from the wider field of clinical supervision, runs counter to CBT's empirical roots, and under-values supervision as a discrete professional specialization. For these reasons, it is argued that new developments should be grafted onto the current approach. In future, this augmented version of CBT supervision should be subjected to the same kinds of research and development (R&D) activity as CBT. Initially, this could include developing a manual to specify and operationalize this innovative approach, evaluation of manual-based training, andN= 1 research to assess its effectiveness. Examples of preliminary work are provided, and future R&D directions identified.
Genetic analysis of self-reported physical activity and adiposity: The Southwest Ohio Family Study
Authors: Choh Audrey C , Demerath Ellen W , Lee Miryoung , Williams Kimberly D , Towne Bradford , Siervogel Roger M , Cole Shelley A , Czerwinski Stefan A
Published: September 2008

Objective

Physical inactivity poses a major risk for obesity and chronic disease, and is influenced by both genetic and environmental factors. However, the genetic association between physical activity (PA) level and obesity is not well characterized. Our aims were to: (i) estimate the extent of additive genetic influences on physical activity while adjusting for household effects; and (ii) determine whether physical activity and adiposity measures share common genetic effects.

Subjects

The sample included 521 (42 % male) adult relatives, 18–86 years of age, from five large families in the Southwest Ohio Family Study.

Design

Sport, leisure and work PA were self-reported (Baecke Questionnaire of Habitual Physical Activity). Total body and trunk adiposity, including percentage body fat (%BF), were measured using dual-energy X-ray absorptiometry. Abdominal visceral and subcutaneous adipose tissue mass were measured using MRI.

Results

Heritabilities for adiposity and PA traits, and the genetic, household and environmental correlations among them, were estimated using maximum likelihood variance components methods. Significant genetic effects (P< 0·05) were found for sport (h2= 0·26) and leisure PA (h2= 0·17). Significant (P< 0·05) household effects existed for leisure PA (c2= 0·25). Sport PA had a negative genetic correlation with central adiposity measurements adjusted for height (ρG> |−0·40|). Sport and leisure PA had negative genetic correlations with %BF (ρG> |−0·46|).

Conclusions

The results suggest that the association of sport and leisure PA with lower adiposity is due, in part, to a common genetic inheritance of both reduced adiposity and the predisposition to engage in more physical activity.
Association between obesity indices and blood pressure or hypertension: which index is the best?
Authors: Zhou Ziqiang , Hu Dayi , Chen Jie
Published: September 2008

Background

The association between obesity and blood pressure is well documented and a series of obesity indices are used as risk factors or indicators of blood pressure and/or the presence of hypertension.

Objective

The aim of the present study was to explore and determine which obesity index is the best indicator of blood pressure and the presence of hypertension among five frequently used simple anthropometric indices.

Methods

Subjects (n 29 079) were selected by cluster sampling from fourteen Chinese general populations. Weight, height, waist circumference (WC), hip circumference and blood pressure were measured for each participant. BMI, waist:hip ratio (WHR), waist:stature ratio (WSR) and conicity index (CI) were calculated. Pearson correlation, multiple logistic regression, multivariate linear regression and receiver-operating characteristic (ROC) curve analyses were used.

Results

A total of 13 558 men and 15 521 women were investigated. All five obesity indices were positively correlated with blood pressures and hypertension. After adjusting for age, WSR in men and BMI in women had the greatest association with the presence of hypertension, irrespective of the statistical method used. BMI had the strongest correlation with continuous blood pressures in both genders.

Conclusion

The present results indicate that hypertension is associated with different obesity indices in men and in women. The best indicator for hypertension is WSR in men while it is BMI in women.
A commentary on current practice in mediating variable analyses in behavioural nutrition and physical activity
Authors: Cerin Ester , MacKinnon David P
Published: September 2008

Objective

To critique current practice in, and provide recommendations for, mediating variable analyses (MVA) of nutrition and physical activity behaviour change.

Strategy

Theory-based behavioural nutrition and physical activity interventions aim at changing mediating variables that are hypothesized to be responsible for changes in the outcome of interest. MVA are useful because they help to identify the most promising theoretical approaches, mediators and intervention components for behaviour change. However, the current literature suggests that MVA are often inappropriately conducted, poorly understood and inadequately presented. Main problems encountered in the published literature are explained and suggestions for overcoming weaknesses of current practice are proposed.

Conclusion

The use of the most appropriate, currently available methods of MVA, and a correct, comprehensive presentation and interpretation of their findings, is of paramount importance for understanding how obesity can be treated and prevented.
Efficiency of three DNA markers in revealing genetic variation among wild Cajanus species
Authors: Aruna Rupakula , Manohar Rao D. , Sivaramakrishnan S. , Reddy L. Janardhan , Bramel Paula , Upadhyaya Hari
Published: September 2008

Wild relatives of pigeonpea (Cajanus cajanL.) possess many useful genes that can be utilized for crop improvement, most importantly genes for resistance toHelicoverpa armigera, the legume pod borer. The present study aimed at quantifying diversity in a collection ofCajanus scarabaeoides, Cajanus sericeus,Cajanus reticulatusandC. cajanspecies selected from a wide geographic range using two PCR-based marker systems, amplified fragment length polymorphism (AFLP) and simple sequence repeats (SSRs), and the hybridization-based restriction fragment length polymorphism (RFLP). Polymorphism was higher among the wild accessions than among the cultivated genotypes. Wild and cultivatedCajanusaccessions belonging to different species clustered into four distinct major groups largely based on the interspecific differences.C. scarabaeoidesaccessions derived from same geographical origins formed one group reflecting similar genetic makeup of these accessions. Dendrograms generated using AFLP, RFLP and SSR marker data were comparable with minor clustering differences, which suggests that either method, or a combination of both can be applied to expanded genetic studies inCajanus.Mantel testing confirmed the congruence between the genetic distances of three markers, indicating that the markers segregated independently, giving similar grouping patterns of all accessions having similar genetic origin.
The Relative Autonomy of the EU Human Rights Standard
Authors: LB  , JHR
Published: September 2008

To this day the founding treaties of the European Union contain no legally binding bill of rights in the traditional sense protecting religion, privacy, family life, the freedom of expression, and so forth. As we all know, while the European Court of Justice initially rejected appeals relying on fundamental rights as found in national constitutions, the Court changed its position under pressure of German courts.
Rex, Lex et Judex
Authors: Schönfeld K.M.
Published: September 2008

Doubts about the traditional, positivistic interpretation of Montesquieu's ‘bouche de la loi’-text – Reading Montesquieu in his historical context – England and France: judge made law and parlementaire ideology – Natural law context – Lex animata, lex loquens: King versus judge – The Ciceronian and English background of the ‘bouche de la loi’ – The Fronde and les Mazarinades – George Buchanan, Sir Edward Coke and Calvin's Case
Developmental Assessment
Authors: Petermann Franz , Macha Thorsten
Published: September 2008

Developmental diagnostics has a long-standing tradition of more than 100 years and is closely connected with the assessment of children’s abilities, for instance, intelligence. It aims at providing differentiated analysis of developmental status, at contrasting normal and abnormal development, and at evaluating the potential for further development.
Holocene eruptive history of the Stromboli volcano: Constraints from paleomagnetic dating
Authors: Speranza Fabio , Pompilio Massimo , D'Ajello Caracciolo Francesca , Sagnotti Leonardo
Published: September 2008

We report on paleomagnetic directions gathered from 33 sites from (mostly Holocene) volcanics from Stromboli, loosely dated at present by few K/Ar and 14C ages. In order to provide dating, the paleomagnetic directions were compared to the Holocene paleosecular variation of the geomagnetic field for the Mediterranean region, derived from direct geomagnetic observations and several archeomagnetic‐paleomagnetic data sets. Petrochemical analyses from the paleomagnetic specimens revealed that each Holocene eruptive cycle of Stromboli was characterized by peculiar chemical characteristics. We suggest that before the 20th century AD paroxysms, powerful spatter‐forming eruption(s) occurred during the 17th century AD, followed by three centuries of less energetic eruptions, when spattering was limited to the summit cones. A robust data set (4 sites, 52 samples) from the S. Bartolo flow, partially buried below the Stromboli village, constrains its age to 360 BC to 7 AD, in Greek‐Roman times. The ca. 6200 years BP age inferred for a scoria exposed below a characteristic pyroclastic succession suggests its correlation with the Secche di Lazzaro pyroclastics, a major phreatomagmatic eruption occurring during the 6th millennium BP, synchronous with the major volcanotectonic collapse of the Sciara del Fuoco. Ages were provided for many lavas from the Neostromboli sequence (including the Labronzo, Nel Cannestrà, and Ginostra flows), indicating that huge effusive activity from lateral fissures fed by an evolving magma chamber occurred in the ∼6200–8000 years BP time window. The absence of volcanics with ages comprised between the 6th millennium BP and 400 BC implies a puzzling three‐millennia “eruption gap” at Stromboli.
The global attenuation structure of the upper mantle
Authors: Dalton Colleen A. , Ekström Göran , Dziewoński Adam M.
Published: September 2008

A large data set of fundamental mode Rayleigh wave amplitudes is analyzed to derive a new global three‐dimensional model of shear wave attenuation in the upper mantle. The amplitude observations span a range of periods between 50 and 250 s and are derived from earthquakes with MW > 6.0 that occurred between 1993 and 2005. Four separate factors may influence an amplitude anomaly: intrinsic attenuation along the raypath, elastic focusing effects along the raypath, uncertainties in the strength of excitation, and uncertainties in the response at the station. In an earlier paper (Dalton and Ekström, 2006a), dependence of the retrieved attenuation structure on these terms was shown to be significant and an approach was developed to invert the amplitudes simultaneously for each term. The new three‐dimensional attenuation model QRFSI12, which is the subject of this paper, is derived using this method. The model contains large lateral variations in upper‐mantle attenuation, ±60% to ±100%, and exhibits strong agreement with surface tectonic features at depths shallower than 200 km. At greater depth, QRFSI12 is dominated by high attenuation in the southeastern Pacific and eastern Africa and low attenuation along many subduction zones in the western Pacific. Resolution tests confirm that the change in pattern of attenuation above and below 200‐km depth can be determined with confidence using the fundamental mode data set. The new model is highly correlated with global models of shear wave velocity, particularly in the uppermost mantle, suggesting that the same factors may control both seismic attenuation and velocity in this depth range. However, forcing the lateral perturbations in attenuation to match those found in global velocity models decreases the data variance reduction, which suggests that subtle differences between patterns of attenuation and velocity are robust.
Response of the Denmark Strait overflow to Nordic Seas heat loss
Authors: Grist Jeremy P. , Josey Simon A. , Sinha Bablu , Blaker Adam T.
Published: September 2008

The impact of extreme Nordic Seas heat loss on Denmark Strait (DS) dense water transport is examined in (1) control runs of the Hadley Centre HadCM3 and HadGEM1 coupled climate models and (2) perturbation experiments with the fast coupled model FORTE that allow heat flux effects to be isolated from wind stress. All three models show an approximately linear increase in southward DS transport of cold dense water with increasing Nordic Seas winter heat loss in the range −80 to −250 Wm−2. The propagation of the cold anomaly from the Nordic Seas source along a trajectory through the DS and into the Irminger Basin is also examined. A common response time is found with the strongest decrease in DS temperature occurring within 8–12 months of the heat loss signal. Our results show that Nordic Seas heat loss must be considered in addition to other processes in understanding DS variability.
A brief review of the problem of lightning initiation and a hypothesis of initial lightning leader formation
Authors: Petersen Danyal , Bailey Matthew , Beasley William H. , Hallett John
Published: September 2008

A brief review of hypothesized mechanisms of lightning initiation is presented, with the suggestion that these mechanisms provide an incomplete picture of lightning initiation. This is followed by two ideas: (1) a combination of previously hypothesized lightning initiation mechanisms as a means for local intensification of the thundercloud electric field, and (2) a process for the formation of a hot lightning leader channel that is analogous to the space leader phase of the laboratory negative stepped leader. Thundercloud electric field observations have consistently yielded peak values that are an order of magnitude weaker than the dielectric strength of air. Various mechanisms have been proposed to explain how lightning can initiate in such weak electric fields, including hydrometeor‐initiated positive streamers and cosmic ray‐initiated runaway breakdown. The historically favored positive streamer mechanisms are problematic due to requiring electric fields two to three times larger than peak observed fields. The recently favored runaway breakdown mechanisms appear capable of developing in conditions comparable to peak observed fields although it is not clear how these diffuse discharges can lead to creation of a lightning leader. This paper proposes a solution whereby runaway breakdown and hydrometeor‐initiated positive streamer systems serve to locally intensify the electric field. Following this local field intensification, it is hypothesized that formation of the initial lightning leader channel is analogous to the formation of a space leader in a laboratory negative stepped leader.
Investigation of carbonyls in cloudwater during ICARTT
Authors: Li Shao‐Meng , Macdonald Anne Marie , Leithead Amy , Leaitch W. Richard , Gong Wanmin , Anlauf Kurt G. , Toom‐Sauntry Desiree , Hayden Kathy , Bottenheim Jan , Wang Daniel
Published: September 2008

Air borne measurements carried out in the summer of 2004 in the lower Great Lakes region as part of the ICARTT 2004 study are used to examine the effects of clouds on the carbonyls in the atmosphere. Concentrations of seven carbonyl species in bulk cloudwater samples were measured with concurrent gas phase HCHO measurements. In the cloudwater, the most abundant carbonyl was HCHO with a median value of 11.9 μmol L−1, followed by acetaldehyde (4.3 μmol L−1), acetone (1.9 μmol L−1), pentanal (1.4 μmol L−1), benzaldehyde (0.5 μmol L−1), butanal (0.4 μmol L−1), and propanal (0.2 μmol L−1). The relative abundance of propanal to acetaldehyde in the cloudwater was substantially lower than estimates from primary emissions. The cloudwater abundance of HCHO relative to the sum of the other carbonyls was found to increase with altitude in the clouds that penetrated the boundary layer. During most flights, the total in‐cloud HCHOt (cloudwater + interstitial gas phase) was similar to cloud base HCHOg, suggesting that HCHO was distributed between the two phases through partitioning governed by Henry's law. However, during at least one flight, HCHOt was significantly depleted in the cloud. Finally, the equilibrium gas phase mixing ratios predicted from the cloudwater for all carbonyls but HCHO were much higher than previously measured in the gas phase.
Features of upper troposphere and lower stratosphere aerosols observed by lidar over Gadanki, a tropical Indian station
Authors: Kulkarni Padmavati , Ramachandran S. , Bhavani Kumar Y. , Narayana Rao D. , Krishnaiah M.
Published: September 2008

Upper troposphere (UT) and lower stratosphere (LS) aerosol characteristics are studied over a tropical station Gadanki (13.5°N, 79.2°E), using 532‐nm Nd:YAG lidar during 2001–2005. Scattering ratios (SR) and aerosol extinction are found to exhibit seasonal and interannual variations in UT (10–15 km) and LS (18–30 km). SR is about 1.00–1.2 in the 10‐ to 30‐km altitude region. Aerosol extinction is about 0.5–6 × 10−3 km−1. SR in UT in 2001 and 2004 during winter is lower than that of summer, whereas LS winter profiles are found to have higher SR values. SR values apparently experience a shift in altitude corresponding to the seasonal change in tropopause indicating a relation between the two. UT integrated extinction is about 2.5 times higher than LS extinction. The correlation between UT and LS monthly mean aerosol extinction was weak and negative with a coefficient of 0.4. UT and LS aerosol extinctions over Gadanki are found to exhibit an increasing trend during 2001–2005. The percentage contribution of integrated aerosol extinction in the 10‐ to 30‐km region to aerosol optical depth (AOD) is about 12%. Correlation coefficient between monthly mean AOD and the 10‐ to 30‐km integrated extinction is about 0.6. The increasing trends in UT and LS aerosols seem to support the finding that emissions from subtropical and tropical Asia may have already started to influence the amount of sulfur containing gases reaching UT and LS. This becomes relevant in the climate change context as it has been shown that increasing aerosol abundances may be impacting the monsoon.
Inferring the effect of catchment complexity on mesoscale hydrologic response
Authors: Fröhlich Holger L. , Breuer Lutz , Vaché Kellie B. , Frede Hans‐Georg
Published: September 2008

The effect of catchment complexity on hydrologic and hydrochemical catchment response was characterized in the mesoscale Dill catchment (692 km2), Germany. This analysis was developed using multivariate daily stream concentration and discharge data at the basin outlet, in connection with less frequently sampled catchment‐wide end‐member chemistries. The link between catchment‐wide runoff sources and basin output was observed through a combination of concentration‐discharge (C‐Q) analysis and multivariate end‐member projection. Subsurface stormflow, various groundwater and wastewater sources, as well as urban surface runoff emerged in catchment output chemistry. Despite the identification of multiple sources, several runoff sources observed within the catchment failed to display consistent links with the output chemistry. This failure to associate known source chemistry with outlet chemistry may have resulted from a lack of hydraulic connectivity between sources and basin outlet, from different arrival times of subbasin‐scale runoff contributions, and also from an overlap of source chemistries that subsumed discrete runoff sources in catchment output. This combination of catchment heterogeneity and complexity simply suggests that the internal spatial organization of the catchment impeded the application of lumped mixing calculations at the 692 km2 outlet. Given these challenges, we suggest that in mesoscale catchment research, the potential effects of spatial organization should be included in any interpretation of highly integrated response signals, or when using those signals to evaluate numerical rainfall‐runoff models.
A New Web‐Based Catalog of Earth Degassing Sites in Italy
Authors: Chiodini G. , Valenza M. , Cardellini C. , Frigeri A.
Published: September 2008

Italy is a region characterized by intense and widespread processes of Earth degassing. High‐temperature gases are released by crater plumes and fumaroles in volcanic environments throughout Italy. Also prevalent are numerous low‐temperature gas emissions rich in carbon dioxide (CO2). These low‐temperature emissions are located in a large area, mainly in the western sector of central and southern Italy (Figure 1).
Ground Deformation Imagery of the May Sichuan Earthquake
Authors: Stramondo Salvatore , Chini Marco , Salvi Stefano , Bignami Christian , Zoffoli Simona , Boschi Enzo
Published: September 2008

The magnitude Mw = 7.8 earthquake that struck China's Sichuan region on 12 May 2008 (Figure 1a) has been imaged by the Italian Space Agency's (ASI) Constellation of Small Satellites for the Mediterranean Basin Observation (COSMO)‐SkyMed radar Earth observation satellites. Five images were available—two preseismic spotlight mode images and three strip‐map mode images, two of which are preseismic and one of which is postseismic. We used two strip‐map images (acquired 1 month prior to and 3 days after the earthquake) to generate the first ever X‐band (i.e., microwave frequency domain, corresponding to about 3‐ centi meter wavelength) coseismic interferogram, which clearly shows part of the strong ground deformation caused by the fault dislocation. We also performed a change detection analysis of the same data that highlighted several changes in the radar response, presumably due to strong seismic damage, as far as 80 kilo meters away from the epicenter.
Land Management in the Anthropocene: Is History Still Relevant?: Incorporating Historical Ecology and Climate Change Into Land Management; Lansdowne, Virginia, 22–25 April 2008
Authors: Safford Hugh D. , Betancourt Julio L. , Hayward Gregory D. , Wiens John A. , Regan Claudia M.
Published: September 2008

Ecological restoration, conservation, and land management are often based on comparisons with reference sites or time periods, which are assumed to represent “natural” or “properly functioning” conditions. Such reference conditions can provide a vision of the conservation or management goal and a means to measure progress toward that vision. Although historical ecology has been used successfully to guide resource management in many parts of the world, the continuing relevance of history is now being questioned. Some scientists doubt that lessons from the past can inform management in what may be a dramatically different future, given profound climate change, accelerated land use, and an onslaught of plant and animal invasions.
Planetary Ring Systems
Authors: Murray Carl
Published: September 2008

Life used to be simple for ring scientists. Since the time of Galileo, anyone with even the most basic telescope could see that Saturn was the only planet with rings. Saturn's ring system is clearly bright, broad, and bland. James Clerk Maxwell proved that the rings could not be solid, and basic spectroscopy showed that they are composed primarily of water ice. There is also a clear connection between the location of the gap between Saturn's A and B rings and an orbital resonance with Mimas, one of Saturn's moons. No other connections between ring locations and moons were known.
Antarctic ice‐sheet melting provides negative feedbacks on future climate warming
Authors: Swingedouw D. , Fichefet T. , Huybrechts P. , Goosse H. , Driesschaert E. , Loutre M.‐F.
Published: September 2008

We show by using a three‐dimensional climate model, which includes a comprehensive representation of polar ice sheets, that on centennial to millennial time scales Antarctic Ice Sheet (AIS) can melt and moderate warming in the Southern Hemisphere, by up to 10°C regionally, in a 4 × CO2 scenario. This behaviour stems from the formation of a cold halocline in the Southern Ocean, which limits sea‐ice cover retreat under global warming and increases surface albedo, reducing local surface warming. Furthermore, we show that AIS melting, by decreasing Antarctic Bottom Water formation, restrains the weakening of the Atlantic meridional overturning circulation, which is a new illustration of the effect of the bi‐polar oceanic seesaw. Consequently, it appears that AIS melting strongly interacts with climate and ocean circulation globally. It is therefore necessary to account for this coupling in future climate and sea‐level rise scenarios.
Solar forcing of Holocene droughts in a stalagmite record from West Virginia in east‐central North America
Authors: Springer Gregory S. , Rowe Harold D. , Hardt Ben , Edwards R. Lawrence , Cheng Hai
Published: September 2008

Elevated Sr/Ca ratios and δ13C values in Holocene‐age stalagmite BCC‐002 from east‐central North America record six centennial‐scale droughts during the last five North Atlantic Ocean ice‐rafted debris (IRD) episodes, previously ascribed to solar irradiance minima. Spectral and cross‐spectral analyses of the multi‐decadal resolution Sr/Ca and δ13C time series yield coherent ∼200 and ∼500 years periodicities. The former is consistent with the de Vries solar irradiance cycle. Cross‐spectral analysis of the Sr/Ca and IRD time series yields coherent periodicities of 715‐ and 455‐years, which are harmonics of the 1,450 ± 500 year IRD periodicity. These coherencies corroborate strong visual correlations and provide convincing evidence for solar forcing of east‐central North American droughts and strengthen the case for solar modulation of mid‐continent climates. Moisture transport across North America may have lessened during droughts because of weakened north‐south temperature and pressure gradients caused by cooling of the tropical Pacific and Atlantic Oceans.
Comparison of new and existing global digital elevation models: ASTER G‐DEM and SRTM‐3
Authors: Hayakawa Yuichi S. , Oguchi Takashi , Lin Zhou
Published: September 2008

A new global elevation dataset known as G‐DEM, based on the ASTER satellite imagery, will be released in late 2008. G‐DEM will be the best freely available global digital elevation model (DEM) at a horizontal resolution of 1 arc second. We assess the quality of G‐DEM in comparison with 3‐arc‐second SRTM DEM, the best current global elevation dataset. Basic geomorphometric parameters (elevation, slope and curvature) were examined for a pre‐release version of G‐DEM and SRTM DEM for western Japan. G‐DEM has fewer missing cells than SRTM DEM, particularly in steep terrain. Also, G‐DEM gives smoother and more realistic representations of lowlands, valleys, steep slopes, and mountain ridges, whereas, SRTM DEM includes many local spikes and holes, and tends to overestimate valley‐floor elevation and underestimate ridge elevation. G‐DEM will be commonly used in geoscientific studies, because of its higher resolution, fewer missing data, and better topographic representation than SRTM DEM.
Wintertime temperature maximum at the subtropical stratopause in a T213L256 GCM
Authors: Tomikawa Y. , Sato K. , Watanabe S. , Kawatani Y. , Miyazaki K. , Takahashi M.
Published: September 2008

A wintertime temperature maximum can be observed at the subtropical stratopause but does not appear in the radiative equilibrium temperature distribution. This structure was well simulated using a high‐resolution general circulation model and examined in detail. The stratopause temperature is latitudinally maximized in the winter subtropics because of a strong downwelling of the meridional circulation from summer tropics to winter subtropics passing above the stratopause. Its strong meridional flow consists of two parts: a strong poleward flow in the winter subtropics with nearly vertically aligned contours of absolute angular momentum (M) and a strong cross‐equatorial flow toward winter hemisphere above the tropical stratopause with nearly horizontally aligned M contours. The strong poleward flow in the winter subtropics is driven by a large Eliassen‐Palm (E‐P) flux convergence in a small absolute vorticity region. The large E‐P flux convergence is due to extratropical planetary waves and asymmetric inertial instability. On the other hand, the strong cross‐equatorial flow is induced along the M contour to satisfy mass continuity with the strong poleward flow in the winter subtropics and exists in the easterly phase of S‐SAO with a small latitudinal gradient of M. The easterly of S‐SAO during its mature phase acts as a corridor for cross‐equatorial meridional circulation, while cross‐equatorial meridional circulation contributes to driving the easterly of S‐SAO in its development phase.