bluuebunny/crossref_metadata_2025 huggingface dataset:
The Central Intellective Factor
Authors: Rimoldi H. J. A.
Published: February 2006

The proof of the existence of “g” is more than a methodological problem and concerns the very core of psychological theory. The principles of noegenesis should be identified experimentally before a final opinion can be rendered about “g.” Many general factors isolated in different studies are not necessarily “g.” In the present study a second-order unrotated general factor has been identified by using Thurstone's method. It seems possible to identify this factor with “g.” In the first order, factors that seem to represent the first and second principles of noegenesis have been found. The existence of synthetic and analytic activities and their interplay in intellectual performances is indicated. The relation of likeness is of great interest in explaining cognitive abilities and is isolated both as a first and second order factor. For the final identification of factors the search should be conducted beyond the elementary listing of tests. The dynamic aspects underlying factors are more meaningful than their simple description. The second order gives indications that allow for a better interpretation of fundamental psychological activities.
Oxygen isotope composition of annually banded modern and mid-Holocene travertine and evidence of paleomonsoon floods, Grand Canyon, Arizona, USA
Authors: O'Brien Gary R. , Kaufman Darrell S. , Sharp Warren D. , Atudorei Viorel , Parnell Roderic A. , Crossey Laura J.
Published: February 2006

Holocene and modern travertine formed in spring-fed Havasu Creek of the Grand Canyon, Arizona, was studied to determine the factors governing its oxygen-isotope composition. Analysis of substrate-grown travertine indicates that calculated calcite-formation temperatures compare favorably with measured water temperatures, and include silt-rich laminae deposited by monsoon-driven floods. Ancient spring-pool travertine is dated by U-series at 7380 ± 110 yr and consists of 14 travertine-silt couplets of probable annual deposition. One hundred eighty high-resolution δ18O analyses of this mid-Holocene sample average −11.0‰ PDB. The average value for modern travertine is ∼0.5‰ lower, perhaps because mid-Holocene temperature was higher or there was proportionally greater summer recharge. δ18O cyclicity in the mid-Holocene travertine has average amplitude of 1.9 ± 0.5‰ PDB, slightly less than the inferred modern-day annual temperature range of Havasu Creek. The annual temperature range might have been reduced during the 14-yr interval compared to present, although other non-temperature factors could account for the muted annual variation. Silt-rich laminae within isotopically lower calcite in the modern and mid-Holocene travertine verifies the seasonal resolution of both samples, and suggests that similar temperature-precipitation conditions, as well as monsoon-generated summer floods, prevailed in the mid-Holocene as they do throughout the Grand Canyon region today.
Episodic Late Holocene dune movements on the sand-sheet area, Great Sand Dunes National Park and Preserve, San Luis Valley, Colorado, USA
Authors: Forman S.L. , Spaeth M. , Marín L. , Pierson J. , Gómez J. , Bunch F. , Valdez A.
Published: February 2006

The Great Sand Dunes National Park and Preserve (GSDNPP) in the San Luis Valley, Colorado, contains a variety of eolian landforms that reflect Holocene drought variability. The most spectacular is a dune mass banked against the Sangre de Cristo Mountains, which is fronted by an extensive sand sheet with stabilized parabolic dunes. Stratigraphic exposures of parabolic dunes and associated luminescence dating of quartz grains by single-aliquot regeneration (SAR) protocols indicate eolian deposition of unknown magnitude occurred ca. 1290–940, 715 ± 80, 320 ± 30, and 200–120 yr ago and in the 20th century. There are 11 drought intervals inferred from the tree-ring record in the past 1300 yr at GSDNPP potentially associated with dune movement, though only five eolian depositional events are currently recognized in the stratigraphic record. There is evidence for eolian transport associated with dune movement in the 13th century, which may coincide with the “Great Drought”, a 26-yr-long dry interval identified in the tree ring record, and associated with migration of Anasazi people from the Four Corners areas to wetter areas in southern New Mexico. This nascent chronology indicates that the transport of eolian sand across San Luis Valley was episodic in the late Holocene with appreciable dune migration in the 8th, 10–13th, and 19th centuries, which ultimately nourished the dune mass against the Sangre de Cristo Mountains.
Late Quaternary paleosols, stratigraphy and landscape evolution in the Northern Pampa, Argentina
Authors: Kemp Rob A. , Zárate Marcelo , Toms Phillip , King Matthew , Sanabria Jorge , Arguello Graciella
Published: February 2006

The field properties, micromorphology, grain-size, geochemistry, and optically stimulated luminescence (OSL) ages of two late Quaternary sections have been used to reconstruct the sequence of pedosedimentary processes and to provide insights into landscape evolution in part of the Northern Pampa of Argentina. Paleosols developed in paludal sediments adjacent to the Paraná river at Baradero and in loess at Lozada can both be correlated and linked to other sites, thus enabling for the first time the tentative recognition and tracing of a diachronous soil stratigraphic unit that probably spans the equivalent of at least part of marine oxygen isotope stage (OIS) 5. The paleosol at Lozada was truncated and buried beneath fluvial sediments during the time span of OIS 4 and 3. Eolian gradually replaced paludal inputs at Baradero over this period, and there were also two clearly defined breaks in sedimentation and development of paleosols. The period corresponding to OIS 2 was marked by significant loess accumulation at both sites with accretion continuing into the mid-Holocene only at Lozada. The more developed nature of the surface soil at Baradero probably reflects a combination of a moister climate and a longer soil-forming interval.
Social extremity, communities of fate, and the sociology of SARS
Authors: Baehr Peter
Published: February 2006

This article identifies the chief factors which transform a group of people into a “community of fate”. A community of fate refers to a temporary form of existence, born of duress and social emergency, which cuts across familiar divisions to elicit something socially consequential. One such community materialized during the 2003 Severe Acute Respiratory Syndrome (SARS) outbreak in Hong Kong. It is examined here in detail together with a range of other crisis communities – from Montreal battling smallpox, to the captives of the Warsaw Ghetto.
Incidence of complementary therapy use in patients undergoing vestibular assessment
Authors: Baguley David M , Humphriss Rachel L , Butler Katy , Knight Richard , Dawson Lisa , Vickers Fiona , Mitchell Alice
Published: February 2006

Objectives: To determine the incidence of use of complementary therapies in patients with vestibular symptoms undergoing vestibular assessment.

Design: A prospective, questionnaire-based study.

Setting: A UK university hospital department of audiology with secondary and tertiary referrals.

Participants: A consecutive series of 80 patients seen for vestibular assessment between November 2004 and May 2005.

Main outcome measures: Use of complementary therapies; actual therapies used and patients' subjective opinion of efficacy.

Results: Thirteen patients (16 per cent) had tried some form of complementary therapy for their vestibular symptoms. Ginkgo biloba and acupuncture were the two most popular treatments. Seven patients made their decision as to which treatment to try on the basis of personal recommendation. Six of the 13 patients (46 per cent) reported that their choice of treatment(s) helped them.

Conclusions: Sixteen per cent of patients seen for vestibular assessment had tried some form of complementary therapy for their vestibular symptoms. Clinicians should be aware of this and of the potential interactions between complementary therapies and conventional medicine.
Aerodynamic, acoustic and functional results of posterior transverse laser cordotomy for bilateral abductor vocal fold paralysis
Authors: Dursun Gürsel , Gökcan M Kürşat
Published: February 2006

Bilateral abductor vocal fold paralysis (BAVFP) is a rare but life-threatening condition which may require an emergency tracheotomy procedure. The ideal surgical technique for this condition should improve quality of life by relieving the airway obstruction while preserving laryngeal functions such as phonation and deglutition. Posterior transverse laser cordotomy (PTLC) was first described by Dennis and Kashima as a technique for providing an airway at the posterior glottis without pre-operative tracheotomy; they reported it as a successful method with satisfactory functional results. The aim of this prospective study was to evaluate long term acoustic, aerodynamic and functional results of the primary bilateral PTLC technique in 22 BAVFP patients. Severity of dyspnoea was evaluated using a five-level subjective symptom scale graded according to the limitation in daily activity and level of respiratory difficulty. Aerodynamic and acoustic analyses were performed pre-operatively and prospective changes in aerodynamic and acoustic parameters were collected after one post-operative year.
A Precocious Appetite: Industrial Agriculture and the Fertiliser Revolution in Java's Colonial Cane Fields, c. 1880–1914
Authors: Knight G. Roger
Published: February 2006

Late colonial sugar cane production in Java was characterised by the heavy use of (chemical) fertiliser in tandem with labour-intensive techniques and industrial work processes in the field. This article provides a useful corrective to an overemphasis on the extractive nature of the colonial economy of sugar and shows the truly industrial nature of plantation production. For students of colonial science and agriculture, the situation has additional ramifications, relating both to the role and ‘diffusion’ of scientific knowledge and to the historical dimensions of agricultural development in ‘the tropics’.
Meditations on a Portrait from Seventeenth-Century Batavia
Authors: Taylor Jean Gelman
Published: February 2006

A seventeenth-century painting, ‘Pieter Cnoll and His Family’ by J. J. Coeman, reveals a number of entry points from which Indonesian histories can be explored. Through a discussion of the painting and its subjects, a variety of issues ranging from VOC (United East India Company) policies and mestizo relationships to gender, labour and legal rights in VOC-controlled ports are discussed.
Forward kinematic solution and its applications for a 3-DOF parallel kinematic machine (PKM) with a passive link
Authors: Bi Z. M. , Lang S. Y. T.
Published: February 2006

In this paper, a 3-DOF parallel kinematic machine (PKM) with a passive link is introduced. The forward kinemaic model is established, and a new technique is proposed to solve this model. The developed forward kinematic solver (FKS) is employed in two new applications: the determination of joint workspace and sensor-based real-time monitoring. A joint workspace concept is proposed for the optimization of a PKM structure. It is defined as a reachable area in the joint coordinate system under given ranges of active joint motions. The larger a joint workspace is, the higher utilization of joint motion capacity is. Sensor-based monitoring is applied in real-time system operation, by which a remote user can monitor a PKM through Internet based on the feedbacks of the joint encoders or the on-site stereo camera.
KNOWLEDGE (‘ILM) AND CERTITUDE (YAQĪN) IN AL-FĀRĀBĪ’S EPISTEMOLOGY
Authors: BLACK DEBORAH L.
Published: February 2006

The concept of ‘‘certitude” (yaqīn) is central in Arabic discussions of the theory of demonstration advanced by Aristotle in the Posterior Analytics. In the Arabic tradition it is ‘‘certitude,” rather than ‘‘knowledge” (‘ilm=Greek epistēmē), that is usually identified as the end sought by demonstrations. Al-Fārābī himself devotes a short treatise, known as the Conditions of Certitude (šarā’iṭ al-yaqīn), to determining the criteria according to which a subject can claim to have absolute certitude of any proposition. In this article the author traces the roots of the concept of certitude to the Arabic translation of the Posterior Analytics. She then offers a close reading of the text of al-Fārābī's Conditions and its parallels in his Epitome of the Posterior Analytics (Kitāb al-Burhān). She argues that the identification of certitude as a cognitive state distinct from knowledge enabled al-Fārābī to introduce a number of interesting and sometimes problematic innovations into Arabic epistemology. Foremost amongst his positive innovations is the recognition that contingent as well as necessary propositions allow for an attenuated form of certitude, and the introduction of reliabilism into the justification of claims to certitude. But al-Fārābī is also one of the first philosophers to articulate explicitly the idea that certitude must include an element of ‘‘knowing that one knows,” a controversial principle that tends to undermine both al-Fārābī’s reliabilism and his efforts to loosen some of the strictures in traditional Aristotelian epistemology.
GEOPONICA AND NABATEAN AGRICULTURE: A NEW APPROACH INTO THEIR SOURCES AND AUTHORSHIP
Authors: CARRARA ANGELO ALVES
Published: February 2006

This article returns to an old but not hitherto satisfactorily solved question, and aims at putting forward a new approach to the study of the sources and authorship of two contemporary treatises on agriculture: the Nabatean Agriculture (in Arabic al-Filāḥa al-nabaṭiyya) and the Geoponica. Each of them embodies a long tradition reaching from Antiquity to the 10th century in two different cultural provinces expressed in Greek / Latin and Arabic languages. But there is another common feature of these works. Both of them survived in a significant number of manuscripts, and constitute a kind of revision of previous compilations which drew their contents from more ancient treatises brought to light between the 3rd and 6th centuries AD, and to some extent could be qualified as the outcome of an effort for systematising the corpus of agronomical science. Texts and translations from Greek to Latin, from Greek to Syriac or to Arabic, and from Arabic to Armenian attest to this cultural intercommunication.
AL-MAˇGŪSĪ'S KITĀB AL-MALAKĪ AND ITS LATIN TRANSLATION ASCRIBED TO CONSTANTINE THE AFRICAN: THE RECONSTRUCTION OF PANTEGNI, PRACTICA, LIBER III
Authors: VEIT RAPHAELA
Published: February 2006

Constantine the African's significance as the first important translator of medical texts from Arabic into Latin is indisputable due to the fact that his work contributed decisively to the enlargement of medical knowledge in the Latin West. Among his considerable œuvre the translation of al-Maˇgūsī's Kitāb al-Malakī under its Latin title Pantegni, the first real medical compendium in Latin, holds a particularly important position because of its popularity. The Pantegni is divided into the two parts Theory and Practice with ten books each. Yet while the Theorica Pantegni corresponds basically to the Theory in the Kitāb al-Malakī, this is only partly the case for the Practica Pantegni. The content of the differing parts has been put together mainly from other medical texts. The identification of these other medical texts was the aim of some important researches while the last ten years (see especially the articles in Charles Burnett and Danielle Jacquart [eds.], Constantine the African and ‘Alī ibn ‘Abbās al-Maˇgūsī: The Pantegni and Related Texts [Leiden / New York / Cologne, 1994]). The aim of this article is to present the sources of the Pantegni, Practica’s third book and to give some indications on the person who made the compilation who – as it seems – wasn't Constantine the African himself.
SPIRITS: THE REACTIVE SUBSTANCES IN JĀBIR'S ALCHEMY
Authors: EL-ESWED BASSAM. I.
Published: February 2006

The spirits (arwāḥ) found in Arabic alchemical texts, namely zi'baq, kibrīt, nūshādir and zarnīkh are identified with their modern counterparts, which are mercury, sulfur, ammonium chloride (carbonate) and arsenic (arsenous) sulfide, respectively. Jābir's conception of spirits has been shown to be related to his practice. The puzzling experiments of Jābir on ‘mineral and organic’ spirits are compared as far as possible with modern knowledge of chemistry. These comparisons lead to an understanding of Jābir's sequence of manipulations within the logic of his alchemy. In treatment of naturally occuring spirits, Jābir aimed at removing the combustibility of spirits and so improving their effect on fusible bodies. Jābir's notion of transmutation (iqlāb) of fusible bodies is shown to be a flexible term that is equivalent to purification (tanẓīf) or reformation (iṣlāḥ).
Dialogue act recognition under uncertainty using Bayesian networks
Authors: KEIZER SIMON , AKKER RIEKS OP DEN
Published: February 2006

In this paper we discuss the task of dialogue act recognition as a part of interpreting user utterances in context. To deal with the uncertainty that is inherent in natural language processing in general and dialogue act recognition in particular we use machine learning techniques to train classifiers from corpus data. These classifiers make use of both lexical features of the (Dutch) keyboard-typed utterances in the corpus used, and context features in the form of dialogue acts of previous utterances. In particular, we consider probabilistic models in the form of Bayesian networks to be proposed as a more general framework for dealing with uncertainty in the dialogue modelling process.
P3 and ERD/ERS in a Visual Oddball Paradigm
Authors: Sochurková Daniela , Brázdil Milan , Jurák Pavel , Rektor Ivan
Published: February 2006

Abstract: Objective: The present study investigates intracerebrally the concurrent occurrence of event-related potentials (ERPs) and event-related desynchronization/synchronization phenomena (ERD/ERS) in subjects performing a visual oddball task. Methods: Evoked (P3) and induced ERD/ERS changes were studied in six subjects with drug-resistant epilepsy. Depth EEG activity from the mesiotemporal limbic structures (amygdala, hippocampus, and parahippocampal gyrus) was analyzed. We used an averaging of raw data to obtain ERPs, and an averaging of the amplitude/power envelope (complex demodulation) in five frequency bands: theta, α 1, α 2, beta, and gamma to obtain ERD/ERS. The P3 component of ERP and ERD/ERS in response to target and nontarget stimuli were evaluated. Results: Even though both P3 and ERD/ERS phenomena were observed in all of the investigated mesiotemporal regions, the most pronounced findings were revealed in the hippocampus. A P3 component of ERP was repeatedly observed in the hippocampus after target stimuli. Significant changes in the oscillatory hippocampal activity were found: ERD in the α 1 and α 2 frequency bands. Evident, near-significant changes were observed throughout the hippocampus in the theta band. No apparent ERD/ERS changes in the beta or in the gamma frequency band were seen in our intracerebral data. The distribution of the P3 and ERD/ERS maxima differed slightly in adjacent contacts, but occurred at the same time. Conclusions: The cognitive processing of visual information is simultaneously accompanied by several electrophysiological phenomena. In addition to ERPs, apparent changes in oscillatory activity were detected in the intracerebral recordings from mesiotemporal limbic structures. Timing of both neuronal processes seems to be simultaneous, but differing spatial distribution could reflect the involvement of different networks.
MPI‐DING reference glasses for in situ microanalysis: New reference values for element concentrations and isotope ratios
Authors: Jochum Klaus Peter , Stoll Brigitte , Herwig Kirstin , Willbold Matthias , Hofmann Albrecht W. , Amini Marghaleray , Aarburg Susanne , Abouchami Wafa , Hellebrand Eric , Mocek Beate , Raczek Ingrid , Stracke Andreas , Alard Olivier , Bouman Claudia , Becker Stefan , Dücking Marc , Brätz Helene , Klemd Reiner , de Bruin Deon , Canil Dante , Cornell Dave , de Hoog Cees‐Jan , Dalpé Claude , Danyushevsky Leonid , Eisenhauer Anton , Gao Yongjun , Snow Jonathan E. , Groschopf Nora , Günther Detlef , Latkoczy Christopher , Guillong Marcel , Hauri Erik H. , Höfer Heidi E. , Lahaye Yann , Horz Kersten , Jacob Dorrit E. , Kasemann Simone A. , Kent Adam J. R. , Ludwig Thomas , Zack Thomas , Mason Paul R. D. , Meixner Anette , Rosner Martin , Misawa Keiji , Nash Barbara P. , Pfänder Jörg , Premo Wayne R. , Sun Weidong D. , Tiepolo Massimo , Vannucci Riccardo , Vennemann Torsten , Wayne Dave , Woodhead Jon D.
Published: February 2006

We present new analytical data of major and trace elements for the geological MPI‐DING glasses KL2‐G, ML3B‐G, StHs6/80‐G, GOR128‐G, GOR132‐G, BM90/21‐G, T1‐G, and ATHO‐G. Different analytical methods were used to obtain a large spectrum of major and trace element data, in particular, EPMA, SIMS, LA‐ICPMS, and isotope dilution by TIMS and ICPMS. Altogether, more than 60 qualified geochemical laboratories worldwide contributed to the analyses, allowing us to present new reference and information values and their uncertainties (at 95% confidence level) for up to 74 elements. We complied with the recommendations for the certification of geological reference materials by the International Association of Geoanalysts (IAG). The reference values were derived from the results of 16 independent techniques, including definitive (isotope dilution) and comparative bulk (e.g., INAA, ICPMS, SSMS) and microanalytical (e.g., LA‐ICPMS, SIMS, EPMA) methods. Agreement between two or more independent methods and the use of definitive methods provided traceability to the fullest extent possible. We also present new and recently published data for the isotopic compositions of H, B, Li, O, Ca, Sr, Nd, Hf, and Pb. The results were mainly obtained by high‐precision bulk techniques, such as TIMS and MC‐ICPMS. In addition, LA‐ICPMS and SIMS isotope data of B, Li, and Pb are presented.
Thermal properties of secondary organic aerosols
Authors: Offenberg John H. , Kleindienst Tadeusz E. , Jaoui Mohammed , Lewandowski Michael , Edney Edward O.
Published: February 2006

Volume concentrations of steady‐state secondary organic aerosol (SOA) were measured in several hydrocarbon/NOx irradiation experiments after passing through a constant temperature heated tube. Higher temperatures resulted in greater loss of particle volume. Negatives of the measured effective enthalpies of vaporization (ΔHvap,eff25–300) for SOA range from 11 to 44 kJ mol−1, and depend upon the reactant hydrocarbon (α‐pinene, toluene, or 1,3,5‐trimethylbenzene). Significant negative correlations between ΔHvap,eff25–300 and [NOx] are observed for SOA formed from α‐pinene or toluene. The ΔHvap,eff25–300 of SOA formed in the photooxidation of toluene is similar to that generated by the nebulization of glyoxal, indicating that the oligomers formed by nebulizing glyoxal may represent a surrogate for the chemical mixture formed in toluene photooxidation. These laboratory measurements suggest that the thermodynamic behavior of SOA depends upon the reactant hydrocarbon mixture and NOx concentration.
Validation of a cirrus parameterization with Meteosat Second Generation observations
Authors: Chaboureau Jean‐Pierre , Pinty Jean‐Pierre
Published: February 2006

A brightness temperature difference (BTD) technique is used to constrain the ice to snow autoconversion threshold, a tunable parameter of a bulk microphysical cloud scheme in a regional meteorological model. The technique based on a contrasted absorption property of ice crystals at two wavelengths within the atmospheric infrared window is applied to 3‐hourly Meteosat Second Generation (MSG) observations in the 8.7‐ and 10.8‐μm bands over southern Brazil. The cirrus coverage presents a diurnal cycle associated with tropical deep convection peaking at 1800 local solar time (LST). A similar signal is obtained from the regional model when the ice to snow autoconversion threshold is reevaluated using the BTD data. The improved diurnal cycle furthermore better captures the observed upper‐tropospheric humidity (UTH) maximum that lags the cirrus cover by 12 hours.
Satellite detection of soil moisture impacts on convection at the mesoscale
Authors: Taylor Christopher M. , Ellis Richard J.
Published: February 2006

Understanding of interactions between soil moisture and precipitation is limited by a lack of direct observations at spatial scales on which feedbacks occur. This study identifies a sensitivity of convective cloud to spatial variations in soil moisture, based on analysis of satellite observations from many cases in the Sahel. Patches of wet soil were located using passive microwave data. The patches were composited according to length scale, ranging from 37 to 200 km. The response of the convective cloud field to surface variability along the composite cross‐section was studied with thermal infra‐red data. A suppression of convective cloud is evident over the wet soil during the afternoon and evening for all but the smallest length scales. Analysis of over 100 individual cases where convection occurred in the vicinity of a patch revealed that the development of cloud systems in their early stages appears to be particularly sensitive to soil moisture.
Uplift and subsidence associated with the great Aceh‐Andaman earthquake of 2004
Authors: Meltzner Aron J. , Sieh Kerry , Abrams Michael , Agnew Duncan C. , Hudnut Kenneth W. , Avouac Jean‐Philippe , Natawidjaja Danny H.
Published: February 2006

Rupture of the Sunda megathrust on 26 December 2004 produced broad regions of uplift and subsidence. We define the pivot line separating these regions as a first step in defining the lateral extent and the downdip limit of rupture during that great Mw ≈ 9.2 earthquake. In the region of the Andaman and Nicobar islands we rely exclusively on the interpretation of satellite imagery and a tidal model. At the southern limit of the great rupture we rely principally on field measurements of emerged coral microatolls. Uplift extends from the middle of Simeulue Island, Sumatra, at ∼2.5°N, to Preparis Island, Myanmar (Burma), at ∼14.9°N. Thus the rupture is ∼1600 km long. The distance from the pivot line to the trench varies appreciably. The northern and western Andaman Islands rose, whereas the southern and eastern portion of the islands subsided. The Nicobar Islands and the west coast of Aceh province, Sumatra, subsided. Tilt at the southern end of the rupture is steep; the distance from 1.5 m of uplift to the pivot line is just 60 km. Our method of using satellite imagery to recognize changes in elevation relative to sea surface height and of using a tidal model to place quantitative bounds on coseismic uplift or subsidence is a novel approach that can be adapted to other forms of remote sensing and can be applied to other subduction zones in tropical regions.
Antarctic bottom and lower circumpolar deep water circulation in the eastern Indian Ocean
Authors: Sloyan Bernadette M.
Published: February 2006

Net northward transport below γn > 28.1 kg m−3 (≈3200 m) into the Perth Basin of between 4.4 and 5.8 Sv is estimated from a year‐long current meter mooring array between the Broken and Naturaliste plateaus. Northward transport of between 2.0 and 2.5 Sv of Antarctic Bottom Water (γn > 28.2 kg m−3), that must upwell within the southern region of the Perth Basin, results in an area‐averaged diapycnal velocity and diffusivity of w* = 2.5–3.1 × 10−6 m s−1 and κ = 13–15 × 10−4 m2 s−1, respectively. Diffusivity estimates for the Perth Basin are several times larger than area‐averaged mixing estimates for the abyssal subtropical South Atlantic and Pacific oceans. However, the dissipation of turbulent kinetic energy required to maintain the abyssal mixing in the Perth Basin, ε = O(10−9 W kg−1), is similar to that required in the South Atlantic Ocean. The area‐averaged diffusivity in the Perth Basin does not require unreasonable energy dissipation rates as this ocean basin is only weakly stratified. The abyssal diffusivity of the Perth Basin results from intense mixing at the basin boundary and in the basin interior over rough topography. The complex bathymetry and low abyssal stratification suggests that the Indian Ocean, for a given energy dissipation, may support a larger meridional overturning circulation than other subtropical basins.
A 6‐year analysis of stratospheric intrusions and their influence on ozone at Mt. Cimone (2165 m above sea level)
Authors: Cristofanelli P. , Bonasoni P. , Tositti L. , Bonafè U. , Calzolari F. , Evangelisti F. , Sandrini S. , Stohl A.
Published: February 2006

In this paper we present a study on stratospheric intrusion (SI) events recorded at a high mountain station in the Italian northern Apennines. Six years (1998–2003) of surface ozone and beryllium‐7 concentration measurements as well as relative humidity values recorded at the GAW Mt. Cimone research station (44°11′N, 10°42′E; 2165 m asl) were analyzed. Moreover, three‐dimensional backward trajectories calculated by the FLEXTRA model and potential vorticity values along these trajectories were used. In order to identify SI and evaluate their contribution to the tropospheric ozone at Mt. Cimone, a statistical methodology was developed. This methodology consists of different selection criteria based on observed and modeled stratospheric tracers as well as on tropopause height values recorded by radio soundings. On average, SI effects affected Mt. Cimone for about 36 days/year. The obtained 6‐year SI climatology showed a clear seasonal cycle with a winter maximum and a spring‐summer minimum. The seasonal cycle was also characterized by an interannual variation. In particular, during winter (autumn), SI frequency could be related to the intensity of the positive (negative) NAO phase. In order to separate direct SI from indirect SI, a restrictive selection criterion was set. This criterion, named Direct Intrusion Criterion (DIC), requested that all the analyzed tracers were characterized by stratospheric values. Direct SI affected Mt. Cimone for about 6 days/year, with frequency peaks in winter and early summer. At Mt. Cimone, SI contribution to background ozone concentrations was largest in winter. On average, an ozone increase of 8% (3%) with respect to the monthly running mean was found during direct (indirect) SI. Finally, the typical variations of stratospheric tracers during SI events were analyzed. The analysis of in situ atmospheric pressure values suggested that direct SI were connected with intense fronts affecting the region, while indirect SI were possibly connected with subsiding structures related with anticyclonic areas.
Overview of the Microscopic Imager Investigation during Spirit's first 450 sols in Gusev crater
Authors: Herkenhoff Ken E. , Squyres Steve W. , Anderson Robert , Archinal Brent A. , Arvidson Raymond E. , Barrett Janet M. , Becker Kris J. , Bell James F. , Budney Charles , Cabrol Nathalie A. , Chapman Mary G. , Cook Debbie , Ehlmann Bethany L. , Farmer Jack , Franklin Brenda , Gaddis Lisa R. , Galuszka Donna M. , Garcia Patricia A. , Hare Trent M. , Howington‐Kraus Elpitha , Johnson Jeffrey R. , Johnson Sarah , Kinch Kjartan , Kirk Randolph L. , Lee Ella Mae , Leff Craig , Lemmon Mark , Madsen Morten B. , Maki Justin N. , Mullins Kevin F. , Redding Bonnie L. , Richter Lutz , Rosiek Mark R. , Sims Michael H. , Soderblom Laurence A. , Spanovich Nicole , Springer Richard , Sucharski Robert M. , Sucharski Tracie , Sullivan Rob , Torson James M. , Yen Albert
Published: February 2006

The Microscopic Imager (MI) on the Mars Exploration Rover Spirit has returned images of Mars with higher resolution than any previous camera system, allowing detailed petrographic and sedimentological studies of the rocks and soils at the Gusev landing site. Designed to simulate a geologist's hand lens, the MI is mounted on Spirit's instrument arm and can resolve objects 0.1 mm in size or larger. This paper provides an overview of MI operations, data calibration, processing, and analysis of MI data returned during the first 450 sols (Mars days) of the Spirit landed mission. The primary goal of this paper is to facilitate further analyses of MI data by summarizing the methods used to acquire and process the data, the radiometric and geometric accuracy of MI data products, and the availability of archival products. In addition, scientific results of the MI investigation are summarized. MI observations show that poorly sorted soils are common in Gusev crater, although aeolian bedforms have well‐sorted coarse sand grains on their surfaces. Abraded surfaces of plains rocks show igneous textures, light‐toned veins or fracture‐filling minerals, and discrete coatings. The rocks in the Columbia Hills have a wide variety of granular textures, consistent with volcaniclastic or impact origins. Case hardening and submillimeter veins observed in the rocks as well as soil crusts and cemented clods imply episodic subsurface aqueous fluid movement, which has altered multiple geologic units in the Columbia Hills. The MI also monitored Spirit's solar panels and the magnets on the rover's deck.
Mechanisms of Early Brain Injury after Subarachnoid Hemorrhage
Authors: Cahill W Julian , Calvert John H , Zhang John H
Published: February 2006

Apoptosis is the term given to programmed cell death, which has been widely connected to a number of intracranial pathologies including stroke, Alzheimer's disease, and more recently subarachnoid hemorrhage (SAH). Subarachnoid hemorrhage is a disease, without any form of effective treatment, that affects mainly the young and middle aged and as a result is responsible for severe disability in otherwise healthy and productive individuals. Despite intense research efforts in the field, we currently possess a very limited understanding of the underlying mechanisms that result in injury after SAH. However, a number of studies have recently indicated that apoptosis may be a major player in the pathogenesis of secondary brain injury after SAH. As a result, the apoptotic cascades present a number of potential therapeutic opportunities that may ameliorate secondary brain injury after SAH. Experimental data suggest that these cascades occur very early after the initial insult and may be related directly to physiologic sequela commonly associated with SAH. It is imperative, therefore, to obtain a thorough understanding of the early events that occur after SAH, which will enable future therapies to be developed.
Independence, Dependency and Interdependence: Struggles and Resistances of Minoritized Women within and on Leaving Violent Relationships
Authors: Chantler Khatidja
Published: February 2006

This paper draws on research conducted in Manchester, UK, examining service responses to African, African-Caribbean, Irish, Jewish and South Asian women experiencing domestic violence (Batsleer et al., 2002). Popular discourses of domestic violence, which also feature in services, are underpinned by ‘victim-blaming’ together with an assumption that women only show agency and control when they leave violent relationships, and/or what are constructed as oppressive minority cultures. Contrary to these perceptions, firstly, I note competing notions ascribed to ‘independence’. Secondly, I highlight the strategies of resistance used by minoritized women whether they stay, or leave, abusive relationships, and examine the inter-relationships between gender, class and culture. Thirdly, I outline the level and type of support on offer, including key barriers and dilemmas to accessing sensitive and relevant services that respond to women's positions of minoritization, focusing particularly on refuge or shelter provision as they offer one of the key points of transition for women using domestic violence services. Lastly, I indicate some positive steps that can be taken by helping agencies to respond more appropriately to minoritized women facing domestic violence.
Mesoscale modeling of complex binary fluid mixtures: Towards an atomistic foundation of effective potentials
Authors: Silbermann Jörg R. , Klapp Sabine H. L. , Schoen Martin , Chennamsetty Naresh , Bock Henry , Gubbins Keith E.
Published: February 2006

This paper is devoted to equilibrium molecular-dynamics (MD) simulations of a fully atomistic model of binary mixtures of water (component 1) and ethanol (component 2). We investigate ways to extract from these simulations effective, pairwise additive potentials suitable to describe the interactions between coarse-grained molecules (i.e., beads) in corresponding mesoscale dissipative particle-dynamics simulations. The fully atomistic model employed in MD simulations is mapped onto an implicit water model, where the internal degrees of freedom of ethanol and all the degrees of freedom of water are integrated out. This gives us an effective one-component system consisting only of ethanol beads. The effective interaction potential between a pair of ethanol beads, Φ(R), is approximated at three levels of sophistication. At the lowest one, we approximate Φ(R) by the potential of mean force between the centers of mass of two ethanol beads calculated in the fully atomistic MD simulations; at the second level, we take Φ(R) to be the potential linked to total and direct correlation functions in the hypernetted-chain closure of the Ornstein-Zernike equation. At the third level we approximate Φ(R) numerically by improving it iteratively through the Boltzmann inversion scheme. Our results indicate that the level-one approach works only at the lowest (8 wt %) concentration; the level-two approach works only up to intermediate ethanol concentrations (ca. 50 wt %). Only the Boltzmann inversion scheme works for all, up to the highest concentration considered (70 wt %).
Threshold ion-pair production spectroscopy of HCN
Authors: Hu Q. J. , Zhang Q. , Hepburn J. W.
Published: February 2006

The spectroscopic technique of threshold ion-pair production spectroscopy (TIPPS) has been applied to the triatomic molecule HCN. We have recorded the total ion-pair yield and TIPP spectra for the HCN→H++CN− process using coherent vacuum ultraviolet excitation. From the simulation of our high-resolution TIPP spectrum we have precisely measured the HCN ion-pair threshold EIP0 to be 122244±4cm−1. This value could be used to determine the bond dissociation energy D0(H–CN) to unprecedented accuracy. Our fitting result also showed that rotationally excited instead of cold CN− fragment is favored as the ion-pair dissociation product in the threshold region.
Kinetics of spontaneous change in the localized motions of D-sorbitol glass
Authors: Power G. , Vij J. K. , Johari G. P.
Published: February 2006

The dielectric relaxation spectra of D-sorbitol glass have been studied in real time during annealing at 221.1K, which is 47K below its Tg of 268K. As the glass structurally relaxes during annealing, features of the Johari-Goldstein (JG) relaxation change with time: (i) the relaxation strength decreases, (ii) the relaxation peak at 48Hz shifts to a higher frequency, and (iii) the relaxation spectra become narrower. All seem to follow the relation p∝exp[−(kt)n], where p is the magnitude of a property, k the rate constant, and t the time. The parameter n may well be less than 1, but this could not be ascertained. It is proposed that shift of the relaxation peak to a higher frequency and narrowing of the relaxation spectra occur when local, loosely packed regions of molecules in the glass structure collapse nonuniformly and the relaxation time of some of the molecules in the collapsed state becomes too long to contribute to the JG-relaxation spectra. Consequently, the half width of the spectra decreases, and the relaxation peak shifts to a higher frequency. Molecules whose diffusion becomes too slow after the local regions’ collapse would contribute to the α-relaxation spectra and thus the net relaxation strength would increase on structural relaxation. It is argued that these findings conflict with the NMR-based conclusions that motion of all molecules in the glass and supercooled liquid contributes to the faster relaxation process.
Multiconfiguration time-dependent Hartree method applied to molecular dissociation on surfaces: H2+Pt(111)
Authors: Crespos C. , Meyer H.-D. , Mowrey R. C. , Kroes G. J.
Published: February 2006

Four-dimensional quantum dynamics calculations are performed on the dissociative chemisorption of H2 on Pt(111) using the multiconfiguration time-dependent Hartree method. The aim of this work is to study the performance of the multiconfiguration time-dependent Hartree method for a gas-surface reaction by comparison with the standard time-dependent wave-packet propagation method. The initial-state resolved dissociation probability of H2 is calculated within two four-dimensional models. The first four-dimensional model treats explicitly the rotational motion of the molecule and the H2 dissociation is studied above two different sites of the Pt(111). For this model, only a potential-energy surface of general form was available. This potential was refitted to a sum of product form to allow efficient calculations with the multiconfiguration time-dependent Hartree method. The second model focuses on the description of the center-of-mass motion parallel to the surface, the rotational motion of the molecule being frozen. These four-dimensional quantum dynamics calculations yield important insights which can help with performing full six-dimensional calculations on H2 dissociating on Pt(111). The multiconfiguration time-dependent Hartree method is shown to be particularly efficient for computing initial-state selective dissociation probabilities for the system studied, with a good accuracy and a reduced amount of memory and computational time when compared to the standard time-dependent wave-packet method.
Simulated water adsorption in chemically heterogeneous carbon nanotubes
Authors: Striolo Alberto , Chialvo Ariel A. , Cummings Peter T. , Gubbins Keith E.
Published: February 2006

Grand canonical Monte Carlo simulations are used to study the adsorption of water in single-walled (10:10), (12:12), and (20:20) carbon nanotubes at 298K. Water is represented by the extended simple point charge model and the carbon atoms as Lennard-Jones spheres. The nanotubes are decorated with different amounts of oxygenated sites, represented as carbonyl groups. In the absence of carbonyl groups the simulated isotherms are characterized by negligible amounts of water uptake at low pressures, sudden and complete pore filling once a threshold pressure is reached, and wide adsorption-desorption hysteresis loops. In the presence of a few carbonyl groups the simulated adsorption isotherms are characterized by pore filling at lower pressures and by narrower adsorption-desorption hysteresis loops compared to the results obtained in the absence of carbonyl groups. Our results show that the distribution of the carbonyl groups has a strong effect on the adsorption isotherms. For carbonyl groups localized in a narrow section the adsorption of water may be gradual because a cluster of adsorbed water forms at low pressures and grows as the pressure increases. For carbonyl groups distributed along the nanotube the adsorption isotherm is of type V.
Experimental results for a 1.5MW, 110GHz gyrotron oscillator with reduced mode competition
Authors: Choi E. M. , Marchewka C. D. , Mastovsky I. , Sirigiri J. R. , Shapiro M. A. , Temkin R. J.
Published: February 2006

A new result from a 110GHz gyrotron at MIT is reported with an output power of 1.67MW and an efficiency of 42% when operated at 97kV and 41A for 3μs pulses in the TE22,6 mode. These results are a major improvement over results obtained with an earlier cavity design, which produced 1.43MW of power at 37% efficiency. These new results were obtained using a cavity with a reduced output taper angle and a lower ohmic loss when compared with the earlier cavity. The improved operation is shown experimentally to be the result of reduced mode competition from the nearby TE19,7 mode. The reduced mode competition agrees well with an analysis of the startup scenario based on starting current simulations. The present results should prove useful in planning long pulse and CW versions of the 110GHz gyrotron.
Ab initio and direct quasiclassical-trajectory study of the Cl+CH4→HCl+CH3 reaction
Authors: Troya Diego , Weiss Paula J. E.
Published: February 2006

We present an electronic structure and dynamics study of the Cl+CH4→HCl+CH3 reaction. We have characterized the stationary points of the ground-state potential-energy surface using various electronic structure methods and basis sets. Our best calculations, CCSD(T) extrapolated to the complete basis-set limit based on geometries and harmonic frequencies obtained at the CCSD(T)/aug-cc-pvtz level, are in agreement with the experimental reaction energy and indirect measurements of the barrier height. Using ab initio information, we have reparametrized a semiempirical Hamiltonian so that the predictions of the improved Hamiltonian agree with the higher-level calculations in various regions of the potential-energy surface. This improved semiempirical Hamiltonian is then used to propagate quasiclassical trajectories and characterize the reaction dynamics. The good agreement of the calculated HCl rotational and angular distributions with the experiment indicates that reparametrizing semiempirical Hamiltonians is a promising approach to derive accurate potential-energy surfaces for polyatomic reactions. However, excessive energy leakage from the initial vibrational energy of the CH4 molecule to the reaction coordinate in the trajectory calculations calls into question the suitability of the standard quasiclassical-trajectory method to describe energy partitioning in polyatomic reactions.
Mesoscale transport properties induced by near critical resistive pressure-gradient-driven turbulence in toroidal geometry
Authors: Garcia L. , Carreras B. A.
Published: February 2006

Numerical calculations of resistive pressure-gradient-driven turbulence in toroidal geometry in a range of beta values where the pressure profile is close to critical show self-similarity of space and time scales. These self-similarity properties lead to a fractional diffusive equation for mesoscale tracer-particle transport. The indices of the fractional derivates are consistent with the ones found for resistive pressure-gradient-driven turbulence in cylindrical geometry.
Hydration structure of water confined between mica surfaces
Authors: Leng Yongsheng , Cummings Peter T.
Published: February 2006

We report further molecular dynamics simulations on the structure of bound hydration layers under extreme confinement between mica surfaces. We find that the liquid phase of water is maintained down to 2 monolayer (ML) thick, whereas the structure of the K+ ion hydration shell is close to the bulk structure even under D=0.92nm confinement. Unexpectedly, the density of confined water remains approximately the bulk value or less, whereas the diffusion of water molecules decreases dramatically. Further increase in confinement leads to a transition to a bilayer ice, whose density is much less than that of ice Ih due to the formation of a specific hydrogen-bonding network.
Field emission characteristics of a graphite nanoneedle cathode and its application to scanning electron microscopy
Authors: Neo Yoichiro , Mimura Hidenori , Matsumoto Takahiro
Published: February 2006

A high-brightness electron beam of more than 1011Asr−1m−2 was achieved from a graphite nanoneedle cathode, which was fabricated by simple hydrogen plasma etching of a graphite rod. A field emission was obtained at a high residual pressure of 10−6Torr. The performance of this cold cathode was demonstrated by the fabrication of a scanning electron microscope, which was operated at a high residual pressure of 10−5–10−6Torr. The brightness of this cathode offers a convenient field electron emission source that does not require a massive ultrahigh vacuum system.