bluuebunny/crossref_metadata_2025 huggingface dataset:
Ionization energies of LinX (n = 2, 3; X = Cl, Br, I) molecules
Authors: Veličković Suzana , Djordjević Vesna , Cvetićanin Jelena , Djustebek Jasmina , Veljković Miomir , Nešković Olivera
Published: September 2006

Molecules of LinX (n = 2, 3; X = Cl, Br, I) were examined with a magnetic sector mass spectrometer by surface ionization using a triple rhenium filament impregnated with fullerene (C60). The ionization energies obtained for Li2Cl, Li2Br and Li2I molecules are 3.8 ± 0.1, 3.9 ± 0.1 and 4.0 ± 0.1 eV, respectively. The first ionization energy of Li2Cl is documented, while there are no literature data for the ionization energies of Li2Br and Li2I. The molecules of Li3Cl, Li3Br and Li3I were detected experimentally for the first time with ionization energies of 4.0 ± 0.1, 4.1 ± 0.1 and 4.1 ± 0.1 eV, respectively. The ionization energies of LinX (n = 2, 3; X = Cl, Br, I) are in correlation with the theoretical prediction of their hyperlithiated configurations. Copyright © 2006 John Wiley & Sons, Ltd.
Post-processual Landscape Archaeology: a Critique
Authors: Fleming Andrew
Published: September 2006

Post-processual theorists have characterized landscape archaeology as practised in the second half of the twentieth century as over-empirical. They have asserted that the discipline is sterile, in that it deals inadequately with the people of the past, and is also too preoccupied with vision-privileging and Cartesian approaches. They have argued that it is therefore necessary to ‘go beyond the evidence’ and to develop more experiential approaches, ‘archaeologies of inhabitation’. This article argues that such a critique is misguided, notably in its rejection of long-accepted modes of fieldwork and argument and in its annexation of Cosgrove's rhetoric. ‘Post-processual’ landscape archaeology has involved the development of phenomenological approaches to past landscapes and the writing of hyper-interpretive texts (pioneered by Tilley and Edmonds respectively). It is argued that phenomenological fieldwork has produced highly questionable ‘results’. Some of the theoretical and practical consequences of adopting post-processual landscape archaeology are discussed; it is concluded that the new approaches are more problematic than their proponents have allowed. Although new thinking should always be welcomed, it would not be advisable to abandon the heuristic, argument-grounded strengths of conventional landscape archaeology.
For Whom the Bell Tolls: Social Hierarchy vs Social Integration in the Bell Beaker Culture of Southern France (Third Millennium bc)
Authors: Vander Linden Marc
Published: September 2006

The development of social hierarchy during the European Late Neolithic and Bronze Age is often taken for granted in the literature. The Bell Beaker culture has been given a primary role in this picture as it would correspond to the large-scale diffusion of prestige goods and associated individualistic values. On the basis of the French Midi sequence, this article seeks to demonstrate that the prestige model rests upon a simplistic and abstract perception of the data. Rather than the climax of social competition, the Bell Beaker culture marks the building of new fluid social networks which allowed better circulation of knowledge and people.
Materiality, Personhood and Monumentality in Early Neolithic Britain
Authors: Kirk Trevor
Published: September 2006

Archaeological studies of the material and historical conditions of life have in recent years stimulated discussion of the relationality of people and material culture. Engagement with the material world is one context in which senses of personhood and identity emerge and are transformed. People and materiality are interanimated in the more or less transient events and actions of daily life. Personhood and the material world are loaded with sense and made meaningful through citation and reanimation of cultural values and tradition. This contribution discusses the contingent and possibly transient senses of personhood that may have been constituted in some specific material and historical circumstances relating to early Neolithic monuments in southern Britain. A case study focuses on the relationality of people, animals, earth, stone, architecture and material culture.
The diverse cardiac morphology seen in hearts with isomerism of the atrial appendages with reference to the disposition of the specialised conduction system
Authors: Smith Audrey , Yen Ho Siew , Anderson Robert H. , Connell M. Gwen , Arnold Robert , Wilkinson James L. , Cook Andrew C.
Published: September 2006

Congenital cardiac malformations which include isomerism of the atrial appendages are amongst the most challenging of problems for diagnosis and also for medical and surgical management. The nomenclature for pathological description is controversial, but difficulties can be overcome by the use of a segmental approach. Such an approach sets out the morphology and the topology of the chambers of the heart, together with the types and modes of the atrioventricular, ventriculo-arterial, and venous connections. We have applied this method to a study of 35 hearts known to have isomerism of the atrial appendages. We have already published accounts of 27 of these cases, but these were reviewed for this study in the light of our increased awareness of the implications of isomerism, and 8 new cases were added. After examining, or re-examining, the morphology of every heart in detail, we grouped them together according to their ventricular topology and modes of atrioventricular connection. Then we studied the course of the specialised conduction system, by the use of the light microscope, first in each individual case, and then together in their groups. We conclude that the pathways for atrioventricular conduction in hearts with isomerism of the atrial appendages are conditioned both by ventricular topology, and by the atrioventricular connections. Based on our experience, we have been able to establish guidelines that direct the clinician to the likely location of the conduction tissues.
Fibromuscular dysplasia as the substrate for systemic and pulmonary hypertension in the setting of Moya-Moya disease
Authors: Ou Phalla , Dupont Peggy , Bonnet Damien
Published: September 2006

We report the first case, to the best of our knowledge, of a child with the unusual association of Moya-Moya disease and both systemic and pulmonary hypertension. Histological examination revealed fibromuscular dysplasia as the common denominator for a diffuse arteriopathy.
Neo-aortic valvar function after the arterial switch
Authors: Marino Bradley S. , Wernovsky Gil , McElhinney Doff B. , Jawad Abbas , Kreb Dieuwertje L. , Mantel Suzan F. , van der Woerd Wendy L. , Robbers-Visser Danielle , Novello Rita , Gaynor J. William , Spray Thomas L. , Cohen Meryl S.
Published: September 2006

Objectives: The purpose of our study was to assess the prevalence and progression, during childhood and adolescence, of dilation of the neo-aortic root, and neo-aortic valvar regurgitation, and to identify risk factors for such dilation and regurgitation, after the arterial switch operation.Methods: We included all patients who had undergone an arterial switch operation at The Children's Hospital of Philadelphia, and had been followed for a minimum of 4 years, and had at least 2 postoperative echocardiograms. Neo-aortic valvar regurgitation was quantitatively assessed, and measurements were made of the neo-aortic root at the level of the basal attachment of the leaflets, mid-sinusal level, and the sinutubular junction.Results: We found 82 patients who satisfied the criterions for inclusion, of whom 52 patients had transposition with an intact ventricular septum, and 30 had either an associated ventricular septal defect or double outlet right ventricle. The median follow-up time was 8.8 years (4.1 to 16.4 years). The neo-aortic valve had been replaced in 1 patient. Of the patients, 3 had moderate, 66 had trivial to mild, and 12 had no neo-aortic valvar regurgitation at their most recent follow-up. The regurgitation had progressed by at least 1 grade in 38 of the 82 patients (46.4%). Neo-aortic dilation was noted at the basal attachment of the leaflets, and at mid-sinusal level, which was out of proportion to somatic growth.Conclusions: At mid-term follow-up, significant neo-aortic valve regurgitation is present in 3.7%, and trivial to mild regurgitation in 81.4% of patients. The regurgitation progressed in almost half of the patients over time. We also noted progressive dilation of the neo-aortic root out of proportion to somatic growth.
The ExoMars rover and Pasteur payload Phase A study: an approach to experimental astrobiology
Authors: Barnes Dave , Battistelli Enrico , Bertrand Reinhold , Butera Francesco , Chatila Raja , Del Biancio Alessandro , Draper Chris , Ellery Alex , Gelmi Rolando , Ingrand Felix , Koeck Charles , Lacroix Simon , Lamon Pierre , Lee Chris , Magnani Piergiovanni , Patel Nildeep , Pompei Carlo , Re Eduardo , Richter Lutz , Rowe Mark , Siegwart Roland , Slade Richard , F Smith Mark , Terrien Gregoire , Wall Ronan , Ward Roger , Waugh Lester , Woods Mark
Published: September 2006

The Aurora programme is the European Space Agency programme of planetary exploration focused primarily on Mars. Although the long-term goals of Aurora are uncertain, the early phases of the Aurora programme are based on a number of robotic explorer missions – the first of these is the ExoMars rover mission currently scheduled for launch in 2013 (originally 2011). The ExoMars rover – developed during a Phase A study – is a 240 kg Mars rover supporting a 40 kg payload (called Pasteur) of scientific instruments specifically designed for astrobiological prospecting to search for evidence of extant or extinct life. In other words, ExoMars represents a new approach to experimental astrobiology in which scientific instruments are robotically deployed at extraterrestrial environments of astrobiological interest. Presented is an outline of the design of the rover, its robotic technology, its instrument complement and aspects of the design decisions made. ExoMars represents a highly challenging mission, both programmatically and technologically. Some comparisons are made with the highly successful Mars Exploration Rovers, Spirit and Opportunity.
Frictional response of a thick gouge sample: 1. Mechanical measurements and microstructures
Authors: Chambon Guillaume , Schmittbuhl Jean , Corfdir Alain
Published: September 2006

A 10‐cm‐thick layer of synthetic fault gouge (angular quartz sand with millimetric grains) is sheared over several meters at low confining pressures (0.1–0.5 MPa) using a ring shear apparatus (inner radius of 10 cm). The shear strength of the gouge exhibits a significant slip‐weakening behavior active over decimetric slip distances. Tests on the influence of particle size, particle geometry, and boundary conditions are reported. A long‐term compaction of the gouge samples is also observed but appears to be decoupled from the frictional slip weakening. At microscale, series of photographs taken during the runs enable us to follow the formation of a shear band in which most of displacements and strains localize. From image analysis we estimate the strain field in the material surrounding the shear band and show that this outer region accounts for most of the global volumetric strain. We argue that the mechanical coupling between this outer region and the shear band is responsible for the frictional slip weakening. Accordingly, the complex structure of the fault zone is shown to be crucial for its frictional behavior. Implications of our results for fault mechanics are discussed in the companion paper.
Observations and modeling of energetic electron dynamics during the October 2001 storm
Authors: Miyoshi Y. S. , Jordanova V. K. , Morioka A. , Thomsen M. F. , Reeves G. D. , Evans D. S. , Green J. C.
Published: September 2006

We examined and simulated the dynamics of energetic electrons during the October 2001 magnetic storm with the relativistic RAM electron model for a wide range of energies. The storm had a rapid main phase followed by a day of strong geomagnetic activity that produced a second Dst minimum and then a very quiet recovery phase. During the main phase and the period of intense activity, the observed hot electron flux (E = 30 keV) increased at low L while decreasing at large L and then decayed abruptly at the beginning of the recovery phase when activity subsided. The flux of subrelativistic (E = 100–300 keV) electrons also increased at low L and decreased at large L during the main phase and the period of intense activity but remained high throughout the recovery phase. In contrast, the relativistic (E = 300–1200 keV) electron flux decreased during the main phase, remained low throughout the period of intense activity, and then increased above prestorm values during the recovery phase in spite of the low activity. The highest energy electron flux (E > 1200 keV) decreased during the main phase and never recovered to prestorm levels. The numerical simulation was compared with observations. We identified the physical processes which produce the flux variations at the different energies. In the simulation, the hot electrons were convected inward during the main phase, reproducing the observed local time flux asymmetry. The higher‐energy electrons, on the other hand, were predominantly transported inward by radial diffusion and not convective motion. The simulation was not able to reproduce the subrelativistic and relativistic electron flux enhancement and spatial expansion as observed during the recovery phase. In the simulation, most of the energization occurred around the main phase and the period of intense activity with negligible transport or flux enhancement during the recovery phase. The discrepancy between the observed and simulated high energy electron flux suggests that only convective transport and radial diffusion cannot fully explain the electron dynamics. An additional mechanism may be necessary to explain enhancements of high energy electron flux during the recovery phase of the storm.
Quiet time solar illumination effects on the fluxes and characteristic energies of ionospheric outflow
Authors: Peterson W. K. , Collin H. L. , Lennartsson O. W. , Yau A. W.
Published: September 2006

We report on the characteristic energy, intensity, and flow rate of escaping ionospheric ions as a function of solar illumination. The data presented here were acquired with the Toroidal Ion Mass‐Angle Spectrograph (TIMAS) instrument on the Polar satellite at altitudes of 6000 to 9000 km, during solar minimum. To obtain uniform coverage under various solar illumination conditions, data were restricted to geomagnetically quiet intervals when the Dst index was above −50 nT. We explicitly report data for four magnetic local time ranges. Our investigation confirms many of the characteristics of ion outflows deduced from earlier episodic studies and identifies an anticorrelation in the dependence of beam and conic fluxes on solar illumination, which we attribute to variations in the altitude at which auroral acceleration processes occur. We find that the cusp is an important but not dominant source of ionospheric plasma for the magnetosphere. We conclude that significantly different plasma energization and/or transport mechanisms are dominant in the cusp and the midnight sectors. In addition, we conclude that variations in the solar EUV and geomagnetic energy inputs into the ionosphere, rather than the longer timescale seasonal and annual variations in solar illumination, determine the global rates of H+ and O+ outflow. The data presented here provide comprehensive and realistic boundary conditions for large‐scale magnetospheric models during nonstorm times.
Ensemble‐based air quality forecasts: A multimodel approach applied to ozone
Authors: Mallet Vivien , Sportisse Bruno
Published: September 2006

The potential of ensemble techniques to improve ozone forecasts is investigated. Ensembles with up to 48 members (models) are generated using the modeling system Polyphemus. Members differ in their physical parameterizations, their numerical approximations, and their input data. Each model is evaluated during 4 months (summer 2001) over Europe with hundreds of stations from three ozone‐monitoring networks. We found that several linear combinations of models have the potential to drastically increase the performances of model‐to‐data comparisons. Optimal weights associated with each model are not robust in time or space. Forecasting these weights therefore requires relevant methods, such as selection of adequate learning data sets, or specific learning algorithms. Significant performance improvements are accomplished by the resulting forecasted combinations. A decrease of about 10% of the root‐mean‐square error is obtained on ozone daily peaks. Ozone hourly concentrations show stronger improvements.
Influence of future climate and emissions on regional air quality in California
Authors: Steiner Allison L. , Tonse Shaheen , Cohen Ronald C. , Goldstein Allen H. , Harley Robert A.
Published: September 2006

Using a chemical transport model simulating ozone concentrations in central California, we evaluate the effects of variables associated with future changes in climate and ozone precursor emissions, including (1) increasing temperature; (2) increasing atmospheric water vapor; (3) increasing biogenic VOC emissions due to temperature; (4) projected decreases in anthropogenic NOx, VOC, and CO emissions in California for 2050; and (5) the influence of changing ozone, CO, and methane at the western boundary. Climatic changes expected for temperature, atmospheric water vapor, and biogenic VOC emissions each individually cause a 1–5% increase in the daily peak ozone. Projected reductions in anthropogenic emissions of 10–50% in NOx and 50–70% in VOCs and CO have the greatest single effect, reducing ozone by 8–15% in urban areas. Changes to the chemical boundary conditions lead to ozone increases of 6% in the San Francisco Bay area and along the west coast but only 1–2% inland. Simulations combining climate effects predict that ozone will increase 3–10% in various regions of California. This increase is partly offset by projected future emissions reductions, and a combined climate and emissions simulation yields ozone reductions of 3–9% in the Central Valley and almost no net change in the San Francisco Bay area. We find that different portions of the model domain have widely varying sensitivity to climate parameters. In particular, the San Francisco Bay region is more strongly influenced by temperature changes than inland regions, indicating that air quality in this region may worsen under future climate regimes.
Ozone‐CO correlations determined by the TES satellite instrument in continental outflow regions
Authors: Zhang Lin , Jacob Daniel J. , Bowman Kevin W. , Logan Jennifer A. , Turquety Solène , Hudman Rynda C. , Li Qinbin , Beer Reinhard , Worden Helen M. , Worden John R. , Rinsland Curtis P. , Kulawik Susan S. , Lampel Michael C. , Shephard Mark W. , Fisher Brendan M. , Eldering Annmarie , Avery Melody A.
Published: September 2006

Collocated measurements of tropospheric ozone (O3) and carbon monoxide (CO) from the Tropospheric Emission Spectrometer (TES) aboard the EOS Aura satellite provide information on O3‐CO correlations to test our understanding of global anthropogenic influence on O3. We examine the global distribution of TES O3‐CO correlations in the middle troposphere (618 hPa) for July 2005 and compare to correlations generated with the GEOS‐Chem chemical transport model and with ICARTT aircraft observations over the eastern United States (July 2004). The TES data show significant O3‐CO correlations downwind of polluted continents, with dO3/dCO enhancement ratios in the range 0.4–1.0 mol mol−1 and consistent with ICARTT data. The GEOS‐Chem model reproduces the O3‐CO enhancement ratios observed in continental outflow, but model correlations are stronger and more extensive. We show that the discrepancy can be explained by spectral measurement errors in the TES data. These errors will decrease in future data releases, which should enable TES to provide better information on O3‐CO correlations.
Anoxia and high primary production in the Paleogene central Arctic Ocean: First detailed records from Lomonosov Ridge
Authors: Stein Ruediger , Boucsein Bettina , Meyer Hanno
Published: September 2006

Except for a few discontinuous fragments of the Late Cretaceous/Early Cenozoic climate history and depositional environment, the paleoenvironmental evolution of the pre‐Neogene central Arctic Ocean was virtually unknown prior to the IODP Expedition 302 (Arctic Ocean Coring Expedition–ACEX) drilling campaign on Lomonosov Ridge in 2004. Here we present detailed organic carbon (OC) records from the entire ca. 200 m thick Paleogene OC‐rich section of the ACEX drill sites. These records indicate euxinic “Black Sea‐type” conditions favorable for the preservation of labile aquatic (marine algae‐type) OC occur throughout the upper part of the early Eocene and the middle Eocene, explained by salinity stratification due to freshwater discharge. The superimposed short‐term (“Milankovitch‐type”) variability in amount and composition of OC is related to changes in primary production and terrigenous input. Prominent early Eocene events of algae‐type OC preservation coincide with global δ13C events such as the PETM and Elmo events. The Elmo δ13C Event has been identified in the Arctic Ocean for the first time.
Impact of the Minoan tsunami of Santorini: Simulated scenarios in the eastern Mediterranean
Authors: Pareschi Maria Teresa , Favalli Massimiliano , Boschi Enzo
Published: September 2006

We have simulated the impact of the tsunami generated by the Late Bronze Age (LBA) volcanic eruption of Santorini on the Eastern Mediterranean. Two different tsunami triggering mechanisms were considered: a caldera collapse and pyroclastic flows/surges entering the sea. Simulations include the “worst” input conditions in order to evaluate the maximum possible impacts, but also “lighter” input conditions, compatible with the lack of any tsunami trace on the Northern coasts of Crete. In all the simulations, tsunami propagation is mainly confined to the Southern Aegean. Outside the Aegean, the tsunami impact was negligible and not responsible for the slide‐slumping of fine‐grained pelagic and/or hemipelagic sediments considered the sources of the sporadically located sea‐deposits in the Ionian Sea and of the widespread megaturbidite deposits localized in the Ionian and Sirte Abyssal Plains.
Topographically derived maps of valley networks and drainage density in the Mare Tyrrhenum quadrangle on Mars
Authors: Luo W. , Stepinski T. F
Published: September 2006

A novel, automated technique for delineating Martian valley networks from digital terrain data is applied to the Mare Tyrrhenum quadrangle on Mars, yielding a detailed map for the entire quadrangle. The resultant average value of drainage density for the Noachian part of the quadrangle is D ≈ 0.05 km−1, an order of magnitude higher than the value inferred from a global map based on Viking images, and comparable to the values inferred from the precision mapping of selected focus sites. Valleys are omnipresent in Noachian terrain even outside the “highly dissected” Npld unit. This suggests fluvial erosion throughout the Noachian, implying widespread precipitation. The map of continuous drainage density is constructed to study spatial variations of D. This map reveals significant variations in degree of dissection in Noachian on scale of >100 km. These variations do not correlate with any terrain parameter and their origin requires further study.
Reply to the comment by M. Lockwood et al. on “The IDV index: Its derivation and use in inferring long‐term variations of the interplanetary magnetic field”
Authors: Svalgaard L. , Cliver E. W.
Published: September 2006

From an analysis of geomagnetic and solar wind data, Lockwood et al. [1999] (hereinafter referred to as LSW99) reported that the solar coronal magnetic field had increased by more than a factor of two during the last century. If true, this would be an important discovery. Recently, Svalgaard and Cliver [2005] (hereinafter referred to as SC05) reported an analysis based on our newly developed interdiurnal variability (IDV) index of geomagnetic activity which indicated that cycle averages of the solar field varied no more than ∼25% over the same time interval and are now decreasing. Here, we answer the criticisms of Lockwood et al. [2006] (hereinafter referred to as LRFS06) to our paper. In sum, we find their objections without merit. If our prediction that the next solar cycle will be the smallest in 100 years [Svalgaard et al., 2005] bears out, this debate may be settled by direct solar wind measurements within the next few years. In the following sections we respond to the various points raised by LRFS06: percentage change, Br versus B, regression technique (including the effect of missing data), and analysis procedure.
Plasma depletion and mirror waves ahead of interplanetary coronal mass ejections
Authors: Liu Y. , Richardson J. D. , Belcher J. W. , Kasper J. C. , Skoug R. M.
Published: September 2006

We find that the sheath regions between fast interplanetary coronal mass ejections (ICMEs) and their preceding shocks are often characterized by plasma depletion and mirror wave structures, analogous to planetary magnetosheaths. A case study of these signatures in the sheath of a magnetic cloud (MC) shows that a plasma depletion layer (PDL) coincides with magnetic field draping around the MC. In the same event, we observe an enhanced thermal anisotropy and plasma beta as well as anticorrelated density and magnetic fluctuations which are signatures of mirror mode waves. We perform a superposed epoch analysis of ACE and Wind plasma and magnetic field data from different classes of ICMEs to illuminate the general properties of these regions. For MCs preceded by shocks, the sheaths have a PDL with an average duration of 6 hours (corresponding to a spatial span of about 0.07 AU) and a proton temperature anisotropy T⊥p/T∥p ≃ 1.2–1.3, and are marginally unstable to the mirror instability. For ICMEs with preceding shocks which are not MCs, plasma depletion and mirror waves are also present but at a reduced level. ICMEs without shocks are not associated with these features. The differences between the three ICME categories imply that these features depend on the ICME geometry and the extent of upstream solar wind compression by the ICMEs. We discuss the implications of these features for a variety of crucial physical processes including magnetic reconnection, formation of magnetic holes, and energetic particle modulation in the solar wind.
Three‐dimensional multifluid simulations of ionospheric loss at Mars from nominal solar wind conditions to magnetic cloud events
Authors: Harnett E. M. , Winglee R. M.
Published: September 2006

Three‐dimensional multifluid simulations of the solar wind interaction with a magnetized Mars are used to determine both the effect of the crustal magnetic field on ionospheric loss rate and the ionospheric loss rate as a function of solar wind conditions. Ionospheric losses on the order of 1025 O2+ ions per second are found for quiet solar wind conditions. This is of the same order as that estimated from Phobos 2 measurements. Varying the orientation of Mars' magnetic anomalies relative to the incident solar wind direction leads to only minor variation in the ionospheric loss rates of O2+ for each set of solar wind conditions studied. Solar wind parameters were varied from nominal solar wind conditions to conditions with high‐speed flows, high densities, and large IMF magnitudes. Outflow rates on the order of 1026 O2+ ions per second were seen for storm‐like conditions. The simulations indicate that ionospheric outflow rates increase by a larger percentage for high solar wind number density when compared to high solar wind speed or strong IMF conditions alone. This is due to the higher solar wind density and temperature of the precipitating ions. The results also indicate a significant influence of pickup on ionospheric loss.
Size‐selective nonrefractory ambient aerosol measurements during the Particulate Matter Technology Assessment and Characterization Study–New York 2004 Winter Intensive in New York City
Authors: Weimer Silke , Drewnick Frank , Hogrefe Olga , Schwab James J. , Rhoads Kevin , Orsini Douglas , Canagaratna Manjula , Worsnop Douglas R. , Demerjian Kenneth L.
Published: September 2006

During the Particulate Matter Technology Assessment and Characterization Study–New York (PMTACS‐NY) in January/February 2004 a variety of modern aerosol measurement instruments were deployed at a field site on the campus of Queens College in Queens, New York. These instruments included the Aerodyne Aerosol Mass Spectrometer (Q‐AMS), R&P Particulate Ambient Sulfate and Nitrate monitors (8400S&N), a Particle‐into‐liquid Sampler equipped with ion chromatographs (PILS‐IC), an R&P FDMS TEOM, and several other techniques to measure physical aerosol properties. The PMTACS‐NY 2004 winter campaign was designed to replicate measurements performed at this site during the PMTACS‐NY 2001 summer campaign. The field campaign experienced significant meteorological variability and extreme weather conditions, which together with local and regional aerosol and precursor emissions generated a wide range of PM concentrations at the site, with significant changes in physical aerosol properties as well as aerosol composition as a function of particle size. Q‐AMS quantification procedures and intercomparison studies of nonrefractory species mass concentrations measured with the Q‐AMS and other colocated instruments (PILS‐IC, R&P 8400 S/N, FDMS TEOM, and Sunset Labs OC Analyzer) are presented. The size‐resolved aerosol composition over the measurement period and its variation with time of the day, regional meteorology and local source impacts are discussed. Results obtained during this field campaign are compared to data from the PMTACS‐NY 2001 summer campaign, where aerosol composition was observed to have higher sulfate, significantly lower nitrate content and overall mean aerosol mass size distributions with larger mode diameters.
Evidence of 210Po on Martian dust at Meridiani Planum
Authors: Meslin Pierre‐Yves , Sabroux Jean‐Christophe , Berger Lionel , Pineau Jean‐François , Chassefière Eric
Published: September 2006

Since the Surveyor and Apollo missions and up to the recent Lunar Prospector mission, 222Rn and 210Po have been key isotopes for understanding gas release events and their spatial and temporal variations on the Moon. Comparatively, these isotopes have drawn much less attention on Mars, if any, despite the wealth of information it could bring on the uppermost meters of the regolith, the exchange of volatiles at the surface, and the atmospheric aerosol cycle. Here we present a statistical analysis of the high‐energy end of alpha spectra obtained by the alpha particle X‐ray spectrometer onboard Mars Exploration Rover Opportunity and report evidence of 210Po, a decay product of 222Rn, attached to atmospheric dust. The 210Po surface activity on rocks and soils at the landing site is lower than 3.1 × 10−4 Bq cm−2, but analysis of spectra obtained on the dust capture magnet reveals a 210Po activity of (4.6 ± 2.4) × 10−3 Bq cm−2 (±2σ). This difference is due to the very low dust cover index at the landing site. Owing to frequent dust devils, regional and global dust storms that mobilize substantial amounts of dust and homogenize the dust surface layer, we infer that the global average 222Rn exhalation rate is significantly greater on Mars than on the Moon. This comparison supports the hypothesis that on Mars, radon emanation could be comparatively enhanced by the presence of water in the surficial soil. Analysis of atmospheric spectra yields a radon activity upper limit of 16 ± 5 Bq m−3 during nighttime at the landing site.
Acetylcholine
Authors: Salvaterra Paul M
Published: September 2006

Acetylcholine is a neurotransmitter found in the nervous systems of all animals. It is involved in the control of functions as diverse as locomotion, digestion, cardiac rate, ‘fight and flight’ responses, secretion, learning and memory. Cholinergic dysfunction is associated with neuromuscular diseases such as myasthenia gravis and neurodegenerative disorders such as Alzheimer disease.
Action Potential: Ionic Mechanisms
Authors: Elmslie Keith S
Published: September 2006

The generation and propagation of the action potential requires an inward flux of sodium ions to depolarize the membrane, followed by an outward potassium flux to repolarize the membrane. Voltage‐dependent sodium and potassium channels provide the pathway for the passage of these ions.
Amine Transporters
Authors: Reith Maarten EA
Published: September 2006

Amine transporters in plasma membranes mediate the transport of dopamine, (nor)adrenaline ((nor)epinephrine) and serotonin. These transporters are members of the larger Na
+
and Cl
−
‐dependent neurotransmitter transporters.
Amino Acid Neurotransmitters
Authors: Henley Jeremy M
Published: September 2006

Amino acid neurotransmitters are single amino acid residues that are released from presynaptic nerve terminals in response to an action potential, cross the synaptic cleft, and bind to specific receptor proteins on the postsynaptic membrane to elicit a postsynaptic response.
Amphibian Brains
Authors: Smeets Wilhelmus JAJ , González Agustín
Published: September 2006

Amphibians mark the transition from aquatic to terrestrial life style. From a phylogenetic point of view, amphibians are, therefore, considered of particular interest for a better understanding of evolutionary processes in brain organization of vertebrates.
Arachidonic Acid
Authors: Bazan Nicolas G
Published: September 2006

Bioactive lipids have significant neurobiological actions such
as in the function of ion channels, receptors, neurotransmitter release,
synaptic plasticity and programmes of neuronal gene expression. As a result,
there is rapid increase in the size of the brain's free fatty acid
pool, particularly of arachidonic acid. Arachidonic acid is converted into a
variety of biologically active derivatives through cyclooxygenation and
lipoxygenation.
Axons
Authors: Waxman Stephen G
Published: September 2006

Axons, or nerve fibres, are neuronal extensions that serve as
conduits for the transfer of information from one nerve cell to others.
Blood–Brain Barrier
Authors: Peterson Darryl Ronnie
Published: September 2006

The blood–brain barrier serves to restrict and control the movement of substances between the general circulation and brain extracellular fluid. It participates in regulating the volume and composition of fluid surrounding the brain through specific transport processes, and thus contributes to homeostasis of the central nervous system.
Calcium and Neurotransmitter Release
Authors: Delaney Kerry R
Published: September 2006

Neural information encoded in the pattern of electrical activity
in a neuron is transferred to other neurons by the release of chemical
messengers. The mechanism of release of transmitter substances depends
intimately on the coupling of neuronal depolarization to the elevation of
calcium ion concentration at transmitter release sites.
Cerebellum: Movement Regulation and Cognitive Functions
Authors: Houk James C , Miller Lee E
Published: September 2006

The cerebellum is located in the back of the brain, just above the brainstem. Its important function is to regulate neural signals in other parts of the brain. Most is known about its regulatory actions on neurons that control movement and posture.
Chemical Synapses
Authors: Garner Craig , Nash Joanne
Published: September 2006

Chemical synapses are amongst the most elaborate junctions existing between two cells. They enable chemical neurotransmission to occur within the millisecond range.
Chloride Channels
Authors: Akabas Myles H
Published: September 2006

Chloride channels are integral membrane proteins whose functions are to regulate the movement of chloride ions across cellular membranes. They perform a vital role in physiological processes such as cell volume regulation, epithelial transport, the regulation of nerve and muscle cell membrane excitability and in determining the pH within cytoplasmic membrane‐bound organelles.
Circadian Rhythms
Authors: Young Michael W
Published: September 2006

Animal cells share a highly conserved genetic mechanism for producing circadian 24‐h rhythms. Interactions among clock genes in animal cells generate self‐sustaining molecular oscillations and provide a mechanism for entraining these oscillations to environmental cyclaes of light and dark.
Cortical Plasticity: Use‐dependent Remodelling
Authors: Ergenzinger Edward R , Pons Tim P
Published: September 2006

Sensory representations in the cortex have been shown to
reorganize after alterations of peripheral input. Such reorganization may be
induced by injury or through behavioural training.
Protein Synthesis and Long‐term Synaptic Plasticity
Authors: Schwartz James H
Published: September 2006

Long term synaptic plasticity is a sustained alteration in the
activity of a nerve cell. This change is produced by receptor mediated
induction of gene expression which results in the synthesis of new protein,
both in the neuron’s cell body and at its terminals.
Receptor Binding in Drug Discovery
Authors: Jarnagin Kurt
Published: September 2006

Receptors have formed one of the most successful classes of drug targets, with receptor‐binding analysis being a central component of drug discovery for such targets. Receptor assays are easily established in robust formats, and the advent of high‐throughput screening equipment using robotics and fast, reliable assay technology has made receptor binding one of the most reliable drug discovery technologies available.
Schizophrenia
Authors: Lewis David A , Pierri Joseph N
Published: September 2006

Schizophrenia is a chronic psychiatric disorder characterized by psychotic symptoms and a deterioration in previous levels of functioning; it may be a consequence of abnormalities in the dopamine neurotransmitter system. Treatment includes the combined use of drugs and psychosocial therapy.
Prions
Authors: Heppner Frank L , Aguzzi Adriano
Published: September 2006

The prion is defined as the infectious agent that causes transmissible spongiform encephalopathies, or prion diseases – transmissible degenerative disorders of the central nervous system. The unusual properties of the transmissible agent, or prion, suggested early on that it might be devoid of nucleic acid.
Invertebrate Neuropeptides
Authors: Nässel Dick R
Published: September 2006

Invertebrate neuropeptides are found in neurosecretory cells, interneurons and motor neurons, as well as in endocrine cells of the intestine and in glandular cells of non‐nervous tissue. Neuropeptides can act as neurohormones released into the circulation and/or as local neurohormones released in a paracrine fashion within the nervous system or at muscles or glands.
Autonomic Nervous System
Authors: Gabella Giorgio
Published: September 2006

The autonomic nervous system is a set of nerve cells and nerves that provide the innervation of blood vessels and the airways, intestines and urogenital organs. These nerves regulate and coordinate bodily functions based on secretory activity of glands, on contraction and relaxation of smooth muscle and cardiac muscle, and on sensations arising from deep viscera.
Axonal Transport and the Neuronal Cytoskeleton
Authors: Baas PW , Ahmad FJ
Published: September 2006

The neuronal cytoskeleton is a system of highly organized
polymers that provide architectural support for axons and dendrites, and also
provide railways for the transport of various classes of cytoplasmic
constituents. Molecular motor proteins provide the energy for the transport of
organelles along the cytoskeletal polymers and for the transport of the
polymers themselves.
Repetitive Action Potential Firing
Authors: Canavier CC , Baxter DA , Byrne JH
Published: September 2006

The biophysical basis of repetitive action potential firing can be understood in terms of the opposing positive and negative feedback processes that generate the repetitive activity. The relative timescales of these processes, which can include ion channel activation and inactivation as well as ion accumulation within a cell, are a key factor in the generation of repetitive single‐spike firing, intrinsic burst firing, and network burst firing.
Avian Brains
Authors: Reiner Anton
Published: September 2006

The brain in birds is large, complex and unique in a number of ways, and it underlies the sophisticated cognitive, social and motor behaviours that typify birds.
Cyclic Nucleotide‐gated Ion Channels
Authors: Kramer Richard H
Published: September 2006

Cyclic nucleotide‐gated (CNG) channels are activated by cAMP or cGMP, crucial intracellular messenger molecules that regulate physiological activities in a wide variety of cells. In photoreceptors and olfactory neurons, CNG channels play an essential role in transducing sensory stimuli into electrical and chemical responses.
Brain Imaging: Localization of Brain Functions
Authors: Posner Michael I
Published: September 2006

Neuroimaging provides a method to locate areas of the brain active when organisms perceive or respond to sensory events or carry out a wide variety of tasks. The methods have made it possible to examine where in the brain cognitive and emotional systems are located thus providing new approaches to understanding normal and pathological human information processing.
Epilepsy
Authors: Bowman James , Dudek F Edward , Spitz Mark
Published: September 2006

Epilepsy is a chronic neurological disorder characterized by recurrent epileptic seizures. Brain injury and genetic abnormalities underlie this disorder.
Neural Circuits: Functional Reconfiguration
Authors: Hooper Scott L
Published: September 2006

Animals produce a vast array of behaviours. In part, this
ability arises because the neural networks that produce behaviour are
multifunctional entities capable of producing many different outputs, and
because many different functional neural networks can be created from a single
large neuronal assembly.
Fly Brains
Authors: Heisenberg Martin
Published: September 2006

The fly brain is a condensed mass of about 200 000 nerve
cells, in the head, regulating the fly's behaviour and physiology.
G Protein‐coupled Receptors
Authors: Bockaert Joël
Published: September 2006

Among membrane‐bound receptors that recognize regulatory
messages (hormones, neurotransmitters, photon, odours, etc.) the seven
transmembrane receptors coupled to G proteins are the most numerous (1%
of the genome in vertebrates). They belong to six families that share no
sequence similarities and are targets for more than 50% of the drugs
used in therapy.
GABA as a Neurotransmitter and Neurogenic Signal
Authors: Barker Jeffery L
Published: September 2006

γ‐Aminobutyric acid (GABA) is an amino acid formed enzymatically from glutamate during and after brain development. GABA helps to produce, position and differentiate nerve cells before it mediates modulatory signals between them.
Serotonin
Authors: Azmitia Efrain CG
Published: September 2006

In humans, serotonin is found in all tissues and body fluids. Serotonin can modify a variety of biological and behavioural functions,
including sex, aggression, appetite, locomotor activity, learning and memory,
sleep and hormonal secretion, and it is implicated in a variety of human
illnesses, such as depression, Alzheimer disease, attention deficit disorder,
anorexia nervosa, bulimia, autism and schizophrenia.
Serotonin Receptors
Authors: Hoyer Daniel
Published: September 2006

Serotonin (5‐hydroxytryptamine, 5‐HT) receptors are found both in the central and peripheral nervous system as well as in a number of non‐neuronal tissues in the gut, cardiovascular system and blood cells. 5‐HT has been implicated in the aetiology of a number of diseases such as migraine, hypertension, depression, anxiety, schizophrenia, eating disorders and vomiting. Many of the current treatments for such disorders interact with the 5‐HT system.
Sodium Channels
Authors: Stühmer Walter
Published: September 2006

Biological cells are surrounded by an electrical insulating membrane and have a negative intracellular potential. The energy required to generate this potential difference is efficiently obtained through metabolic energy, which establishes a gradient of ions across membranes. Nature has developed miniature batteries that use this gradient to generate a membrane potential in the form of molecules called ion channels. Sodium channels use the sodium ion gradient to generate positive membrane potentials. Furthermore, generation and conduction of the nervous impulse is based on ionic gradients, as is the generation of electrical discharges used by electric fish to stun their prey while hunting.
Glutamate as a Neurotransmitter
Authors: Mennerick Steven , Zorumski Charles F
Published: September 2006

Glutamate is a major excitatory neurotransmitter in the vertebrate central nervous system. Glutamate receptors are involved in plastic changes in the nervous system and in excitotoxicity.
Neural Information Processing
Authors: Gabbiani Fabrizio , Midtgaard Jens
Published: September 2006

The central nervous system (CNS) is specialized in processing
information originating from a variety of internal and external sources. Its
basic information processing units are called nerve cells, or neurons. Within
the CNS, these elementary building blocks are densely interconnected in
hierarchical and parallel pathways. Information originating from sensory
neurons in contact with the body periphery is gradually transformed along
these pathways to generate specific actions through signals relayed by motor
neurons to peripheral organs.
Limbic System
Authors: Isaacson Robert L
Published: September 2006

The limbic system is a set of neural structures lying underneath
the neocortex and gathered around the deep medial portions of the forebrain.
The nuclei and primitive cortical areas of the limbic system are critically
important for the satisfaction of the essential needs of the individual,
including those of sustenance, procreation, self‐protection and the protection
of offspring.
Motor Neurons and Spinal Control of Movement
Authors: Wolpaw Jonathan R
Published: September 2006

Motor neurons are among the largest neurons in the central nervous system and have long axons that pass through peripheral nerves to innervate muscles. They are the final common pathway through which the brain controls bodily movement. All movements reflect the interaction of supraspinal commands, sensory inputs and spinal cord interneurons.
Long‐term Potentiation
Authors: Lisman John
Published: September 2006

Long‐term potentiation is an activity‐dependent strengthening of synapses that is thought to underlie memory.
Neuronal Firing Pattern Modulation
Authors: Jones Stephen W
Published: September 2006

Neurons generate diverse patterns of action potentials, depending on the intrinsic electrical properties of the neurons and on synaptic inputs from other neurons. The firing pattern of a neuron can be regulated, often by neurotransmitters acting via G protein‐coupled receptors to modulate voltage‐dependent ion channels.
Magnocellular Neurons
Authors: Lemos José R
Published: September 2006

Magnocellular neurons are neuroendocrine cells located in the hypothalamus; they are among the largest cells in the brain, and synthesize the hormones arginine vasopressin and oxytocin.
Hair Cells
Authors: Correia Manning J
Published: September 2006

A hair cell is the sensory cell in the ear that detects sounds and head motion to begin the processes of hearing and balance control.
Molluscan Nervous Systems
Authors: Benjamin Paul R , Kemenes György , Staras Kevin
Published: September 2006

Neural circuits underlying reflex and rhythmic behaviours in molluscs can be understood at the level of single identified neurons. Using these systems, the most important advances have been made in the understanding of the cellular and molecular basis of learning and memory.
Motor System Organization
Authors: Donoghue John P , Sanes Jerome N
Published: September 2006

Control of voluntary movement involves the central nervous system from the spinal cord to the cerbral cortex.