bluuebunny/crossref_metadata_2025 huggingface dataset:
A cognitive collaborative model to improve performance in engineering teams—A study of team outcomes and mental model sharing
Authors: DeFranco Joanna F. , Neill Colin J. , Clariana Roy B.
Published: October 2010

Working collaboratively in teams is an essential element in systems engineering: Interdisciplinary teams are formed to tackle large‐scale, heterogeneous problems requiring skill and knowledge across a wide array of engineering and technical disciplines. While this is widely accepted as necessary, little attention is given to the problem of ensuring effective collaboration across the diverse team. Attention is given to the processes that will be followed, and tools are provided to aid communication; but the critical cognitive aspects that ensure that the team works effectively and efficiently towards a common objective are frequently absent. Instead, managers and team members assume that their disparate mental models have no impact on their collaborative efforts, or that any cognitive dissonance will evaporate naturally and organically. In reality, neither assumption is true, and if these issues are not directly addressed, a team will fall into cooperative rather than collaborative work, which is less effective and efficient. We introduce a framework, the Cognitive Collaborative Model, that explicitly promotes the cognitive collaborative processes necessary for effective engineering teams, and demonstrate its effectiveness in controlled system design and development experiments. Further, we investigate whether this improvement is due to convergence of the individual team member mental models into a shared, or team, mental model, often cited as the basis for high‐performing teams. Finally, we propose a novel multistage evaluation process for mental model convergence using concept maps and Pathfinder analysis. © 2010 Wiley Periodicals, Inc. Syst Eng 14
Generalised self consistent homogenisation as an inverse problem
Authors: Boso D.P. , Lefik M. , Schrefler B.A.
Published: October 2010

Usually in the framework of the self consistent scheme, the homogenised material behaviour is obtained with a symbolic approach. This paper presents a different, fully numerical procedure. We solve a coupled thermo‐mechanical problem for non‐linear composites with brittle long fibres and properties depending on temperature, by using our development of the generalized self‐consistent method. The considered homogenisation scheme is presented as an inverse problem and Artificial Neural Networks are used to solve it. The problem is formulated for n‐layered isotropic elastic‐brittle cylindrical inclusions surrounded by an elasto‐plastic matrix. The influence of possible yielding of the matrix and breakage of the fibres on the effective behaviour of the composite is considered. The method is finally applied to the real case of superconducting strands used for the coils of the future ITER experimental reactor.
Driving forces on interfaces in elastic‐plastic two phase materials
Authors: Mueller R. , Böttcher A. , Xu B.X. , Aurich J. , Gross D.
Published: October 2010

The theory of configurational forces is applied to a standard dissipative medium and specialized to an elastic ideally plastic material. Besides the inhomogeneity and physical volume force contribution an extra volume term appears which accounts for the distribution of the plastic deformation. The numerical treatment within the method of finite elements is briefly presented. The focus is on the driving forces originating from the plastic deformation. The theory is applied to inhomogeneous problems of an elastically misfitting inclusion embedded in an elastic and an elastic ideally plastic material, respectively. In conjunction with an applied load the eigenstrain causes configurational forces at the interface of the inclusion. The interpretation of driving forces for a morphological change of a fixed inclusion volume is given. The examples are motivated by the so‐called rafting phenomenon in nickel‐based alloys for high temperature applications.
Brachial plexus sonoanatomy explained by multiplanar reformatting of digitized anatomy
Authors: Groen Gerbrand J. , Krediet Annelot C. , Moayeri Nizar , Bruhn Jörgen , van Geffen Geert J.
Published: October 2010

Background: The application of ultrasound (US) in peripheral nerve blocks has increased substantially during the last 15 years. However, this technique may have some drawbacks, one of which is the need of a high level of experience of the anaesthesiologist in performing US‐guided blocks, a.o. in interpreting the cross‐sections displayed in the ultrasound images. Sonoanatomical cross‐sections produced by digitized anatomy are easier to understand.

Methods: From seven cadavers by cryomicrotomy a large series of consecutive high‐resolution photographs with an interval of 0.078 mm were obtained from various regions. By multiplanar reformatting perpendicular reconstructions were made using self‐developed software (E‐MAC). Thus, 3‐D tissue blocs were obtained with a voxel size of 78 μm that enabled the reconstruction of oblique cross‐sections, in which sizes, angles and surface areas could be measured. Finally, a movie‐like animation of consecutive cross‐sections including a variable magnification display was built in.

Results: Reconstructions from the 3‐D tissue blocs illustrate important sonoanatomical issues of the brachial plexus (BP). Its proximal nerve roots show varying angulations, whereas the nerves, towards distal, exhibit a shift in internal architecture and changing topography relative to the subclavian and axillary artery. Blood vessels that may hinder needle insertion are highlighted.

Conclusion: Multiplanar reformatting of digitized anatomy has made feasible the reconstructions of non‐standard anatomical planes. The various (oblique) cross‐sections explain the difference between hypo‐echogenic vs hyper‐echogenic structures of the BP‐nerves, the position of the needle tip in the various BP‐approaches, the topography of important blood vessels displayed in US images and illustrates why the US‐probe needs a continuous change in angulation.
Golgi‐localized KIAA0725p regulates membrane trafficking from the Golgi apparatus to the plasma membrane in mammalian cells
Authors: Sato Sei-ichi , Inoue Hiroki , Kogure Takeshi , Tagaya Mitsuo , Tani Katsuko
Published: October 2010

MINT‐8019775: KIAA0725 (uniprotkb:O94830) and GM130 (uniprotkb:Q5PXD5) colocalize (MI:0403) by fluorescence microscopy (MI:0416)
Consolidation of glycosyl hydrolase family 30: A dual domain 4/7 hydrolase family consisting of two structurally distinct groups
Authors: St John Franz J. , González Javier M. , Pozharski Edwin
Published: October 2010

In this work glycosyl hydrolase (GH) family 30 (GH30) is analyzed and shown to consist of its currently classified member sequences as well as several homologous sequence groups currently assigned within family GH5. A large scale amino acid sequence alignment and a phylogenetic tree were generated and GH30 groups and subgroups were designated. A partial rearrangement in the GH30 defining side‐associated β‐domain contributes to the differentiation of two major groups that contain up to eight subgroups. For this CAZy family of Clan A enzymes the dual domain fold is conserved, suggesting that it may be a requirement for evolved function. This work redefines GH family 30 and serves as a guide for future efforts regarding enzymes classified within this family.
American Notes for General Circulation
Authors: Dickens Charles
Published: October 2010

Charles Dickens (1812–1870) is best remembered today for the novels which offer a fantastic, even grotesque panorama of Victorian life, but he was a journalist before he became a novelist. His travel writings have all the energy and urgency of journalism, and these two volumes, drawn from his experiences on a six-month tour of America between January and June 1842, are no exception. Dickens was already hugely popular with the American reading public, and he was lionised wherever he went, but the American Notes, and the American scenes in Martin Chuzzlewit, caused great controversy and were felt by many to insult the people and institutions of the United States. Dickens's dedication of American Notes, to 'those friends of mine in America ... who, loving their country, can bear the truth when it is told good humouredly, and in a kind spirit' suggests that he was not surprised by this reaction.
Aperçu d'une histoire de la langue grecque
Authors: Meillet Antoine
Published: October 2010

The echoes of Greek are heard in many modern languages. For example, the abstract vocabulary of the modern European languages derives largely from the vocabulary of the Greek philosophers and scholars, whether directly or via Latin writers who were educated according to the Greek tradition. First published in 1913, Antoine Meillet's history of Greek shows how the language, derived originally from Indo-European, developed over time in response to sociological and geographical factors. Meillet argues that its complexity is due to the constant borrowing of vocabulary and grammar from contemporary languages and regional dialects. Despite - or because of - its flexible and ever-changing nature, and the lack of consistency in usage between individual city states, Greek eventually became the language of great works of literature, philosophy and science.
The heterogeneity of antipsychotic response in the treatment of schizophrenia
Authors: Case M. , Stauffer V. L. , Ascher-Svanum H. , Conley R. , Kapur S. , Kane J. M. , Kollack-Walker S. , Jacob J. , Kinon B. J.
Published: October 2010

Background

Schizophrenia is a heterogeneous disorder in terms of patient response to antipsychotic treatment. Understanding the heterogeneity of treatment response may help to guide treatment decisions. This study was undertaken to capture inherent patterns of response to antipsychotic treatment in patients with schizophrenia, characterize the subgroups of patients with similar courses of response, and examine illness characteristics at baseline as possible predictors of response.

Method

Growth mixture modeling (GMM) was applied to data from a randomized, double-blind, 12-week study of 628 patients with schizophrenia or schizo-affective disorder treated with risperidone or olanzapine.

Results

Four distinct response trajectories based on Positive and Negative Syndrome Scale (PANSS) total score over 12 weeks were identified: Class 1 (420 patients, 80.6%) with moderate average baseline PANSS total score showing gradual symptom improvement; Class 2 (65 patients, 12.5%) showing rapid symptom improvement; Class 3 (24 patients, 4.6%) with high average baseline PANSS total score showing gradual symptom improvement; and Class 4 (12 patients, 2.3%) showing unsustained symptom improvement. Latent class membership of early responders (ER) and early non-responders (ENR) was determined based on 20% symptom improvement criteria at 2 weeks and ultimate responders (UR) and ultimate non-responders (UNR) based on 40% symptom improvement criteria at 12 weeks. Baseline factors with potential influence on latent class membership were identified.

Conclusions

This study identified four distinct treatment response patterns with predominant representation of responders or non-responders to treatment in these classes. This heterogeneity may represent discrete endophenotypes of response to treatment with different etiologic underpinnings.
Size matters: Early vocabulary as a predictor of language and literacy competence
Authors: LEE JOANNE
Published: October 2010

This paper investigated the predictive ability of expressive vocabulary size and lexical composition at age 2 on later language and literacy skills from ages 3 through 11. Multivariate analysis of covariance was performed to compare 16 language and literacy outcomes between children with large expressive vocabulary size at 24 months (N= 1,073) and those with smaller expressive vocabulary size. Comparisons between large and small verb size groups as a measure of lexical composition were also conducted. Our findings indicate that, after controlling for gender, birth order, ethnicity and socioeconomic status, total vocabulary size at age 2 can significantly predict subsequent language and literacy achievement up to fifth grade. Moreover, vocabulary size is a better predictor of later language ability than lexical composition.
Translation ambiguity in and out of context
Authors: PRIOR ANAT , WINTNER SHULY , MACWHINNEY BRIAN , LAVIE ALON
Published: October 2010

We compare translations of single words, made by bilingual speakers in a laboratory setting, with contextualized translation choices of the same items, made by professional translators and extracted from parallel language corpora. The translation choices in both cases show moderate convergence, demonstrating that decontextualized translation probabilities partially reflect bilinguals’ life experience regarding the conditional distributions of alternative translations. Lexical attributes of the target word differ in their ability to predict translation probability: form similarity is a stronger predictor in decontextualized translation choice, whereas word frequency and semantic salience are stronger predictors for context-embedded translation choice. These findings establish the utility of parallel language corpora as important tools in psycholinguistic investigations of bilingual language processing.
Using contexts to supervise a collaborative process
Authors: Gonzalez Avelino J. , Tsuruta Setsuo , Sakurai Yoshitaka , Nguyen Johann , Takada Kouhei , Uchida Ken
Published: October 2010

This article describes an investigation into the feasibility of using contextual reasoning to monitor and supervise the collaborative work of several knowledge workers working together on a project. Managing large and complex projects is a difficult task that requiressituational awarenessby the project manager to be able to be proactive when possible and to react correctly in the presence of events. In complex projects, effective oversight of the project personnel and the progress of the project are essential in ensuring that project objectives are met. This is especially true of projects that require contributions from various experts, whose interaction may be limited to a Web-based collaborative tool. Such oversight is typically the job of a project manager who is tasked with avoiding cost overruns, shipment delays, and ensuring product effectiveness. We utilizecontext-based reasoningandcontextual graphsas the tools of choice for implementing an agent that emulates the function of a competent project manager. We use rocket design and manufacture as the domain to evaluate our technique. We use a public domain rocket design software package developed by the National Aeronautics and Space Administration as a guide to the domain. The article describes the investigation, its results, and the related works in a collaborative design project.
How Large a Wave? Using the Generic Ballot to Forecast the 2010 Midterm Elections
Authors: Abramowitz Alan I.
Published: October 2010

As Election Day approaches, many political commentators are asking whether the 2010 midterm elections could be a reprise of 1994, when Republicans picked up eight seats in the Senate and 52 seats in the House of Representatives to take control of both chambers for the first time in 40 years. There is almost universal agreement that Republicans are poised to make major gains in both the House and the Senate. And while the GOP's chances of gaining the 10 seats needed to take control of the upper chamber appear remote, results from the generic ballot forecasting model indicate that the 39 seats required to take back the House of Representatives are well within reach.
The Referendum Model: A 2010 Congressional Forecast
Authors: Lewis-Beck Michael S. , Tien Charles
Published: October 2010

Congressional election forecasting has experienced steady growth. Currently fashionable models stress prediction over explanation. The independent variables do not offer a substantive account of the election outcome. Instead, these variables are tracking variables—that is, indicators that may trace the result but fail to explain it. The outstanding example is the generic ballot measure, which asks respondents for whom they plan to vote in the upcoming congressional race. While this variable correlates highly with presidential party House seat share, it is bereft of substance. The generic ballot measure is the archetypical tracking variable, and it holds pride of place in the Abramowitz (2010) model. Other examples of such tracking variables are exposed seats or lagged seats, features of the Campbell (2010) model. The difficulty with such tracking models is twofold. First, they are not based on a theory of the congressional vote. Second, because they are predictive models, they offer a suboptimal forecasting instrument when compared to models specified according to strong theory.
The Rebels' Yell: Mr. Perestroika and the Causes of This Rebellion in Context
Authors: Luke Timothy W. , McGovern Patrick J.
Published: October 2010

Ten years ago this October, the members of the political science community might have heard a short, but quite fascinating, cri de coeur about the prevailing practices of the discipline in the United States at the turn of the century. Circulating as an e-mail message shortly after the 2000 APSA Annual Meeting, it popped up in the inboxes of a few political scientists and graduate students throughout the academy, who then quickly redirected its message to hundreds and then thousands of their colleagues. Signed “Mr. Perestroika,” the e-mail's short passages bemoaned the profession of political science as it was unfolding under the allegedly misguided aegis of an “Orwellian system” of methodological formalism. Portraying the discipline as trapped in this intellectual cul de sac, Mr. Perestroika depicted an essentially degraded social science discipline that favored the political views of a “coterie” of “East Coast Brahmins” by ratifying their narrow methodological practices (cited in Monroe 2005, 9–11). Such practices, based mostly on “statistics or game theory,” wrongly promoted a simplistic and, for far too many students of the state and society, discredited economic understanding of politics. This unenviable methodological parochialism in turn favored a style of “professional correctness” that froze out other political perspectives and analytical approaches (Luke 1999, 345–63) in the discipline's key journals, major organizations, and scholarly practices. For Mr. Perestroika, these distorted academic norms were also compromising the relevance, utility, and validity of political science as an applied social science.
Motivationale und affektive Merkmale unterschätzter Schüler
Authors: Urhahne Detlef , Zhou Ji , Stobbe Martin , Chao Sheng-Han , Zhu Mingjing , Shi Jiannong
Published: October 2010

In diesem Beitrag werden zwei Untersuchungen zur diagnostischen Kompetenz von Lehrkräften und den motivational-affektiven Merkmalen unterschätzter und überschätzter Schüler präsentiert. An den Untersuchungen in Deutschland und China nahmen jeweils acht Grundschulklassen sowie deren Mathematiklehrer teil. Die Viertklässler bearbeiteten einen Mathematikleistungstest und einen Selbstbeschreibungsfragebogen. Die Lehrkräfte schätzten die Schüler in Bezug auf die Testleistung und motivational-affektive Merkmale ein. Auf Grundlage der geschätzten und der tatsächlichen Testleistung erfolgte eine Einteilung in unterschätzte und überschätzte Schüler. Beide Untersuchungen kommen zu übereinstimmenden Ergebnissen. Die Lehrkräfte konnten Testleistungen mit guter Genauigkeit prognostizieren, aber hatten Schwierigkeiten damit motivational-affektive Schülermerkmale richtig einzuschätzen. Unterschätzte Schüler zeigten die gleiche Testleistung und Lernmotivation wie überschätzte Schüler, aber hatten eine niedrigere Erfolgserwartung, ein niedrigeres Fähigkeitsselbstkonzept und eine höhere Leistungsangst. Die Lehrer erwarteten, dass unterschätzte Schüler in der nächsten Mathematikarbeit schlechter abschneiden werden und mit schlechteren Noten zufrieden sind als überschätzte Schüler. Der Beurteilungsfehler der Lehrer beschränkte sich nicht allein auf die Testleistung, sondern generalisierte auf motivational-affektive Schülermerkmale.
E-Learning unterstützte Förderung von selbstreguliertem Lernen an der Universität
Authors: Wagner Petra , Schober Barbara , Gradinger Petra , Reimann Ralph , Spiel Christiane
Published: October 2010

Dieser Beitrag beschreibt die Evaluation eines E-Learning unterstützten Trainingsprogramms zur Förderung des selbstregulierten Lernens bei Studierenden. Neben dem selbstregulierten Lernen verfolgt das Trainingsprogramm mit der Förderung der E-Kompetenz, der Teamarbeit und der Förderung von fachlichen Inhalten in Forschungsmethoden und Evaluation drei weitere Trainingsziele. Die Trainingseffekte wurden anhand eines quasi-experimentellen Pre-Post-Designs geprüft. Dazu nahmen 84 Studierenden an der einjährigen Intervention teil (Trainingsgruppe). Weitere 84 Studierende dienten als Vergleichsgruppe. Die Evaluationsergebnisse sprechen für den Erfolg des Trainingsprogramms. Effekte konnten bei allen vier intendierten Trainingszielen nachgewiesen werden. Hinsichtlich der untersuchten Komponenten zum selbstregulierten Lernen zeigten sich basierend auf dem Phasenmodell der Selbstregulation von Zimmerman (2000 ) Unterschiede zwischen Trainings- und Vergleichsgruppe insbesondere in der Forethought- (z. B. Selbstwirksamkeit) und Self-reflection-Phase (z. B. Umgang mit Misserfolg). Insgesamt legen die Befunde nahe, bei der Gestaltung von E-Learning gestützten Lehrveranstaltungen an der Universität neben der Vermittlung von Fachwissen auch die Selbstregulation systematisch zu fördern sowie die Kooperation innerhalb der Studierenden zu nützen.
Interventioneller Verschluss des persistierenden Foramen ovale nach kryptogenem Insult
Authors: Chatterjee  , Akin  , Nienaber  , Rehders  , Ortak  , Chatterjee  , Ince
Published: October 2010

Ein persistierendes Foramen ovale kann eine mögliche Ursache einer paradoxen zerebralen Embolie sein. Der Verschluss eines persistierenden Foramen ovale ist interventionell mit einer hohen Erfolgsrate möglich und stellt eine Rezidivprophylaxe dar. Diese Arbeit beschreibt die Anatomie, Pathophysiologie, klinische Bedeutung und diskutiert die aktuellen therapeutischen Optionen des persistierenden Foramen ovale für Patienten mit kryptogenem Insult.
Seasonal polar motion excitation from numerical models of atmosphere, ocean, and continental hydrosphere
Authors: Dobslaw H. , Dill R. , Grötzsch A. , Brzeziński A. , Thomas M.
Published: October 2010

Effective angular momentum functions from atmosphere, oceans, and terrestrial water storage are obtained from European Centre for Medium‐Range Weather Forecasts atmospheric data and corresponding simulations with the Ocean Model for Circulation and Tides and the Land Surface and Discharge Model (LSDM). Mass exchanges among the subsystems are realized by means of freshwater fluxes, causing the total ocean mass to vary predominantly annually. Variations in total ocean mass affect the oceanic excitations of the annual wobble by almost 1 milliarc second (mas) for both prograde and retrograde components, whereas the motion term contributions of terrestrial water flow derived from LSDM are found to be 3 orders of magnitude smaller. Since differences to geodetic excitations are not substantially reduced and regional decompositions demonstrate the large spatial variability of contributions to seasonal polar motion excitation that compensate each other when integrated globally, it is concluded that the closure of the seasonal excitation budget is still inhibited by remaining model errors in all subsystems.
Influences of the ocean surface mixed layer and thermohaline stratification on Arctic Sea ice in the central Canada Basin
Authors: Toole J. M. , Timmermans M.‐L. , Perovich D. K. , Krishfield R. A. , Proshutinsky A. , Richter‐Menge J. A.
Published: October 2010

Variations in the Arctic central Canada Basin mixed layer properties are documented based on a subset of nearly 6500 temperature and salinity profiles acquired by Ice‐Tethered Profilers during the period summer 2004 to summer 2009 and analyzed in conjunction with sea ice observations from ice mass balance buoys and atmosphere‐ocean heat flux estimates. The July–August mean mixed layer depth based on the Ice‐Tethered Profiler data averaged 16 m (an overestimate due to the Ice‐Tethered Profiler sampling characteristics and present analysis procedures), while the average winter mixed layer depth was only 24 m, with individual observations rarely exceeding 40 m. Guidance interpreting the observations is provided by a 1‐D ocean mixed layer model. The analysis focuses attention on the very strong density stratification at the base of the mixed layer in the Canada Basin that greatly impedes surface layer deepening and thus limits the flux of deep ocean heat to the surface that could influence sea ice growth/decay. The observations additionally suggest that efficient lateral mixed layer restratification processes are active in the Arctic, also impeding mixed layer deepening.
Methyl halides in surface seawater and marine boundary layer of the northwest Pacific
Authors: Ooki Atsushi , Tsuda Atsushi , Kameyama Sohiko , Takeda Shigenobu , Itoh Sachihiko , Suga Toshio , Tazoe Hirofumi , Okubo Ayako , Yokouchi Yoko
Published: October 2010

The partial pressures of methyl halides (CH3X; X = Cl, Br, or I) and of CHClF2 (HCFC‐22), which are all volatile organic compounds (VOCs), were measured in the air of the marine boundary layer (pVOCair) and in surface seawater (pVOCwater) during a cruise from the subarctic to subtropical regions of the northwest Pacific in summer of 2008. In the northern transition water (TWN) with high biological activity, high levels of the three CH3Xs in surface seawater were frequently observed, probably owing to their enhanced production by phytoplankton. Supersaturation of CH3Br was only present in TWN water, with a saturation anomaly (SCH3Br) of 0.95 [SCH3X = (pCH3Xwater − pCH3Xair)/pCH3Xair]. The highest saturation anomalies for CH3Cl (SCH3Cl = 1.6) and CH3I (SCH3I = 91) were found in the southern subtropical water (STS) with low biological production south of the subtropical front. We found that the molar concentrations of CH3Cl (CCH3Cl) and CH3I (CCH3I) sharply increased with increasing sea surface temperature (SST) in the subtropical waters. The maximum CCH3Cl (144 pmol l−1) was present in STS water at SST = 30°C and is 1.5 times the value extrapolated from the previously reported relationship between CCH3Cl and SST. Photochemical production might have contributed to the production of CH3Cl and CH3I in STS water.
Possible interannual to interdecadal variabilities of the Indonesian throughflow water pathways in the Indian Ocean
Authors: Valsala Vinu , Maksyutov Shamil , Murtugudde Raghu
Published: October 2010

A few possible interannual to interdecadal pathways of the Indonesian throughflow (ITF) water in the Indian Ocean are found from ocean reanalysis data provided by the European Centre for Medium‐Range Weather Forecasts under the name Ocean Re‐Analysis version S3 (ORA‐S3). The data was used in an off‐line mode to evolve a prognostic passive tracer. The tracer sources were prescribed at the ITF entrance channels and the spreading of the ITF in the Indian Ocean were tracked using interannually varying circulations for two separate episodes of 21 years spanning from 1960 to 1980 and from 1980 to 2000. A climatological run of 21 years was carried out for each time period and the differences in tracer spreading between the control and the climatological runs were computed. The empirical orthogonal function (EOF) analysis shows that the dominant mode of the interannual ITF pathway variability in the Indian Ocean is focused on the ITF entrance region into the southeastern tropical Indian Ocean. The first three EOFs collectively explain a total of 50% of the interannual pathway variability out of which EOF‐1 and 2 are significantly correlated with the Indian Ocean Dipole/Zonal Mode (IODZM). The IODZM‐related meridional circulation anomalies cause the ITF axis from the entrance region to be relatively closer to 10°S than the climatological axis which is shifted southward to 15°S∼20°S. The ITF pathways in the Indian Ocean show decadal shifts in the axis with a more direct departure from the entrance region to the western Indian Ocean prior to 1980, whereas a southwestward shift, subduction, and northwestward thermocline trajectories from the entrance region is seen after 1980. The dramatic shift in the surface meridional velocities in the ITF entrance region revealed from the ORA‐S3 data is a potential cause for the interdecadal changes in ITF pathways. The interannual pathways retrieved in this study thus complement the mean pathways of the ITF that were reported in previous studies. The variability in the pathways we found has implications for the crucial region of the southwestern thermocline ridge and the associated ocean‐atmosphere response.
Changes in extreme high water levels based on a quasi‐global tide‐gauge data set
Authors: Menéndez Melisa , Woodworth Philip L.
Published: October 2010

A quasi‐global sea level data set from tide gauges has been used to investigate extreme sea level events and their spatial and temporal variabilities. Modern methods based on a nonstationary extreme value analysis have been applied to the maxima of the total elevations and surges for the period of 1970 and onward. A subset of the data was used to study changes over the 20th century. The analyses demonstrate the magnitude and timing of the seasonal cycle of extreme sea level occurrence, the magnitude of long‐term trends in extreme sea levels, the evidence for perigean and nodal astronomical tidal components in the extremes, and the relationship of the interannual variability in high water levels to other ocean and atmosphere variations as represented by climate indices. The subtraction from the extreme sea levels of the corresponding annual median sea level results in a reduction in the magnitude of trends at most stations, leading to the conclusion that much of the change in the extremes is due to change in the mean values.
Separating physical and biological nutrient retention and quantifying uptake kinetics from ambient to saturation in successive mountain stream reaches
Authors: Covino Timothy , McGlynn Brian , Baker Michelle
Published: October 2010

Hydrological and biogeochemical processes in stream reaches impact the downstream transport of nutrients. The output from one stream reach becomes the input for the next, leading to serial processing along stream networks. The shape of the uptake‐concentration curve for each reach indicates in‐stream biological uptake of nutrient. Combined with physical retention due to hydrologic turnover, both biological and physical retention will control nutrient export downstream. We performed an instantaneous addition of conservative (chloride, Cl) and nonconservative nutrient (nitrate‐nitrogen, NO3‐N) tracers to ascertain the relative roles of physical and biological retention across four adjacent reaches along a 3744 m stream network in the Sawtooth Mountains, ID. Physical retention dominated total retention ranging from 15% to 58% across individual reaches and totaling 81% across the entire stream length. Within each reach, biological uptake was strongly controlled by nutrient concentration. We quantified continuous Michaelis‐Menten (M‐M) kinetic curves for each reach and determined that ambient uptake (Uamb) ranged from 19 to 58 μg m−2 min−1, maximum uptake (Umax) from 65 to 240 μg m−2 min−1, and half‐saturation constants (Km) from 4.2 to 14.4 μg l−1 NO3‐N. Biological retention capacity indicated by Umax decreased in a downstream direction. Although biological retention capacity decreased moving downstream, it did not decrease as much as physical retention, which led to biological retention comprising a larger portion of total retention at downstream reaches. We suggest that accurate assessment of total retention across stream reaches and stream networks requires quantification of physical retention and the concentration‐dependent nature of biological uptake.
Lunar banding in the scleractinian coral Montastraea faveolata: Fine‐scale structure and influence of temperature
Authors: Winter Amos , Sammarco Paul W.
Published: October 2010

Lunar cycles play an important role in controlling biological rhythms in many organisms, including hermatypic corals. Coral spawning is correlated with environmental factors, including surface seawater temperature (SST) and lunar phase. Calcium carbonate skeletons of corals possess minute structures that, when viewed via X‐radiography, produce high‐density (HD) annual banding patterns. Some corals possess dissepiments that serve as the microstructural base for upward corallite growth. Here we report the results of detailed structural analysis of the skeleton of Montastraea faveolata (Scleractinia) (Ellis and Solander, 1786) and quantify the number of dissepiments that occur between HD bands, including interannual and intercorallite variability. Using a 30 year database, spanning from 1961 to 1991, we confirm earlier speculation by several authors that the frequencies of these microbands within a year is tightly linked to the lunar cycle. We also demonstrate that the frequency distribution of the number of these dissepiments per year is skewed to lower numbers. Extensive statistical analyses of long‐term daily SST records (University of Puerto Rico, Mayaguez) revealed that precipitation of dissepiments is suppressed in years of cooler‐than‐average seawater temperature. We propose that dissepiment deposition is driven primarily by lunar cycle and seawater temperature, particularly at lower temperatures, and banding is generally unaffected by normal or high temperatures. These fine‐scale banding patterns are also strongly correlated with the number of lunar months between reproductive spawning events in average or warmer‐than‐average seawater temperature years. This microbanding may represent another proxy for high‐resolution estimates of variance in marine palaeo‐temperatures, particularly during cooler SST years.
Biological and environmental controls on tree transpiration in a suburban landscape
Authors: Peters Emily B. , McFadden Joseph P. , Montgomery Rebecca A.
Published: October 2010

Tree transpiration provides a variety of ecosystem services in urban areas, including amelioration of urban heat island effects and storm water management. Tree species vary in the magnitude and seasonality of transpiration owing to differences in physiology, response to climate, and biophysical characteristics, thereby complicating efforts to manage evapotranspiration at city scales. We report sap flux measurements during the 2007 and 2008 growing seasons for dominant tree species in a suburban neighborhood of Minneapolis–Saint Paul, Minnesota, USA. Evergreen needleleaf trees had significantly higher growing season means and annual transpiration per unit canopy area (1.90 kg H2O m−2 d−1 and 307 kg H2O m−2 yr−1, respectively) than deciduous broadleaf trees (1.11 kg H2O m−2 d−1 and 153 kg H2O m−2 yr−1, respectively) because of a smaller projected canopy area (31.1 and 73.6 m2, respectively), a higher leaf area index (8.8 and 5.5 m2 m−2, respectively), and a longer growth season (8 and 4 months, respectively). Measurements also showed patterns consistent with the species' differences in xylem anatomy (conifer, ring porous, and diffuse porous). As the growing season progressed, conifer and diffuse porous genera had increased stomatal regulation to high vapor pressure deficit, while ring porous genera maintained greater and more constant stomatal regulation. These results suggest that evaporative responses to climate change in urban ecosystems will depend in part on species composition. Overall, plant functional type differences in canopy structure and growing season length were most important in explaining species' differences in midsummer and annual transpiration, offering an approach to predicting the evapotranspiration component of urban water budgets.
Hydrologic response to precipitation pulses under and between shrubs in the Chihuahuan Desert, Arizona
Authors: Moran M. S. , Hamerlynck E. P. , Scott R. L. , Stone J. J. , Holifield Collins C. D. , Keefer T. O. , Bryant R. , DeYoung L. , Nearing G. S. , Sugg Z. , Hymer D. C.
Published: October 2010

Observations of the temporal and spatial distribution of poststorm soil moisture in open shrublands and savannas are limited, yet they are critical to understanding the interaction and feedback between moisture distribution and canopies. The objective of this analysis was to study the hydrologic impacts of precipitation pulses on the upper layer of soils under and between shrubs. The study was based on measurements of precipitation, runoff, and under‐ and between‐shrub soil moisture over a period of 20 years (1990–2009) at a shrub‐dominated site in the Walnut Gulch Experimental Watershed (WGEW) near Tombstone, Arizona. Within much of the root zone (to 30 cm depth), infiltration was not significantly different under versus between shrubs, and the under:between infiltration ratio was not related to pulse size or intensity. However, root‐zone soil moisture was significantly higher between shrubs than under shrubs. The soil moisture measured at the surface (at 5 cm depth) was not consistently different under and between shrubs, but the soil moisture measured at depths of 15 and 30 cm were both significantly higher between shrubs than under shrubs. Considering mechanisms that explain the interaction between plants and soil moisture, we found no differences in infiltration, evaporative losses, and surface soil moisture in locations under and between shrubs. This led to the conclusion that lower root‐zone soil moisture under shrubs was due largely to greater root density under shrubs than between shrubs. This study adds to the understanding of the impact of precipitation patterns on infiltration and soil moisture in shrub‐dominated sites and the potential for vegetation change in arid and semiarid lands.
Ancient numerical daemons of conceptual hydrological modeling: 2. Impact of time stepping schemes on model analysis and prediction
Authors: Kavetski Dmitri , Clark Martyn P.
Published: October 2010

Despite the widespread use of conceptual hydrological models in environmental research and operations, they remain frequently implemented using numerically unreliable methods. This paper considers the impact of the time stepping scheme on model analysis (sensitivity analysis, parameter optimization, and Markov chain Monte Carlo‐based uncertainty estimation) and prediction. It builds on the companion paper (Clark and Kavetski, 2010), which focused on numerical accuracy, fidelity, and computational efficiency. Empirical and theoretical analysis of eight distinct time stepping schemes for six different hydrological models in 13 diverse basins demonstrates several critical conclusions. (1) Unreliable time stepping schemes, in particular, fixed‐step explicit methods, suffer from troublesome numerical artifacts that severely deform the objective function of the model. These deformations are not rare isolated instances but can arise in any model structure, in any catchment, and under common hydroclimatic conditions. (2) Sensitivity analysis can be severely contaminated by numerical errors, often to the extent that it becomes dominated by the sensitivity of truncation errors rather than the model equations. (3) Robust time stepping schemes generally produce “better behaved” objective functions, free of spurious local optima, and with sufficient numerical continuity to permit parameter optimization using efficient quasi Newton methods. When implemented within a multistart framework, modern Newton‐type optimizers are robust even when started far from the optima and provide valuable diagnostic insights not directly available from evolutionary global optimizers. (4) Unreliable time stepping schemes lead to inconsistent and biased inferences of the model parameters and internal states. (5) Even when interactions between hydrological parameters and numerical errors provide “the right result for the wrong reason” and the calibrated model performance appears adequate, unreliable time stepping schemes make the model unnecessarily fragile in predictive mode, undermining validation assessments and operational use. Erroneous or misleading conclusions of model analysis and prediction arising from numerical artifacts in hydrological models are intolerable, especially given that robust numerics are accepted as mainstream in other areas of science and engineering. We hope that the vivid empirical findings will encourage the conceptual hydrological community to close its Pandora's box of numerical problems, paving the way for more meaningful model application and interpretation.
A noninvasive method for measuring the velocity of diffuse hydrothermal flow by tracking moving refractive index anomalies
Authors: Mittelstaedt Eric , Davaille Anne , van Keken Peter E. , Gracias Nuno , Escartin Javier
Published: October 2010

Diffuse flow velocimetry (DFV) is introduced as a new, noninvasive, optical technique for measuring the velocity of diffuse hydrothermal flow. The technique uses images of a motionless, random medium (e.g., rocks) obtained through the lens of a moving refraction index anomaly (e.g., a hot upwelling). The method works in two stages. First, the changes in apparent background deformation are calculated using particle image velocimetry (PIV). The deformation vectors are determined by a cross correlation of pixel intensities across consecutive images. Second, the 2‐D velocity field is calculated by cross correlating the deformation vectors between consecutive PIV calculations. The accuracy of the method is tested with laboratory and numerical experiments of a laminar, axisymmetric plume in fluids with both constant and temperature‐dependent viscosity. Results show that average RMS errors are ∼5%–7% and are most accurate in regions of pervasive apparent background deformation which is commonly encountered in regions of diffuse hydrothermal flow. The method is applied to a 25 s video sequence of diffuse flow from a small fracture captured during the Bathyluck'09 cruise to the Lucky Strike hydrothermal field (September 2009). The velocities of the ∼10°C–15°C effluent reach ∼5.5 cm/s, in strong agreement with previous measurements of diffuse flow. DFV is found to be most accurate for approximately 2‐D flows where background objects have a small spatial scale, such as sand or gravel.
Earthquake scaling characteristics and the scale‐(in)dependence of seismic energy‐to‐moment ratio: Insights from KiK‐net data in Japan
Authors: Oth Adrien , Bindi Dino , Parolai Stefano , Di Giacomo Domenico
Published: October 2010

We investigate earthquake source characteristics and scaling properties using the results of a spectral inversion of more than 29,000 accelerometric borehole recordings from 1,826 earthquakes (MJMA 2.7–8) throughout Japan. We find that the calculated source spectra can be well characterized by the omega‐square model and show on average self‐similar scaling over the entire magnitude range, with median stress drops of 1.1 and 9.2 MPa for crustal and subcrustal events, respectively. The seismic energy‐to‐moment ratio, as theoretically expected if the omega‐square model is valid, shows a strong dependency on stress drop only, which, in conjunction with data selection practice in some studies to cope with limited recording bandwidth, can explain the often observed apparent scale‐dependence. Our observations suggest that there is no significant deviation from similarity of the energy radiation in the investigated magnitude range and that the observed scatter is mainly related to the scatter in stress drop.
Permeability and pore connectivity: A new model based on network simulations
Authors: Bernabé Y. , Li M. , Maineult A.
Published: October 2010

The purpose of this paper is to model the effect of pore size heterogeneity and pore connectivity on permeability. Our approach is that of conceptual modeling based on network simulations. We simulated fluid flow through pipe networks with different coordination numbers and different pipe radius distributions. Following a method widely used in percolation theory, we sought “universal” relationships (i.e., independent of lattice type) between macroscopic properties such as permeability k and porosity ϕ, and, pore geometry attributes such as hydraulic radius rH, coordination number z, and so forth. Our main result was that in three‐dimensional simple cubic, FCC, and BCC networks, permeability obeyed “universal” power laws, k ∝ (z − zc)β, where the exponent β is a function of the standard deviation of the pore radius distribution and zc = 1.5 is the percolation threshold expressed in terms of the coordination number. Most importantly, these power law relationships hold in a wide domain, from z close to zc to the maximum possible values of z. A permeability model was inferred on the basis of the power laws mentioned above. It was satisfactorily tested by comparison with published, experimental, and microstructural data on Fontainebleau sandstone.
Pregravid Obesity Associates With Increased Maternal Endotoxemia and Metabolic Inflammation
Authors: Basu Subhabrata , Haghiac Maricela , Surace Peter , Challier Jean‐Claude , Guerre‐Millo Michele , Singh Katherine , Waters Thaddeus , Minium Judi , Presley Larraine , Catalano Patrick M. , Hauguel‐de Mouzon Sylvie
Published: October 2010

Obese pregnant women develop severe insulin resistance and enhanced systemic and placental inflammation, suggesting associated modifications of endocrine and immune functions. Activation of innate immunity by endotoxins/lipopolysaccharides (LPS) has been proposed as a mechanism for enhancing metabolic alterations in disorders with insulin resistance. The aim of this study was to characterize the immune responses developed by the adipose tissue (AT) and their potential links to maternal endotoxemia in pregnancy with obesity. Blood and subcutaneous abdominal AT were obtained from 120 lean and obese women (term pregnancy) recruited at delivery. Gene expression was assessed in AT and stromal vascular cells isolated from a subset of 24 subjects from the same cohort. Doubling of plasma endotoxin concentrations indicated subclinical endotoxemia in obese compared with lean women. This was associated with significant increase in systemic C‐reactive protein and interleukin‐6 (IL‐6) but not tumor necrosis factor‐α (TNF‐α) concentrations. AT inflammation was characterized by accumulation of CD68+ macrophages with a threefold increased gene expression of the macrophage markers CD68, EMR1, and CD14. Gene expression for cytokines IL‐6, TNF‐α, IL‐8, and monocyte chemotactic protein‐1 (MCP1) and for LPS—sensing CD14, toll‐like receptor 4 (TLR4), translocating chain‐associated membrane protein 2 was 2.5‐5‐fold higher in stromal cells of obese compared to lean. LPS‐treated cultured stromal cells of obese women expressed a 5–16‐fold stimulation of the same cytokines upregulated in vivo. Our data demonstrate that subclinical endotoxemia is associated with systemic and AT inflammation in obese pregnant women. Recognition of bacterial pathogens may contribute to the combined dysfunction of innate immunity and the metabolic systems in AT.