bluuebunny/crossref_metadata_2025 huggingface dataset:
Deactivation of the boron–oxygen recombination center in silicon by illumination at elevated temperature
Authors: Lim Bianca , Bothe Karsten , Schmidt Jan
Published: February 2008

The boron–oxygen‐related recombination center responsible for the light‐induced degradation of solar cells made on boron‐doped oxygen‐contaminated silicon is deactivated by simultaneously annealing the silicon wafer in the temperature range 135–210 °C and illuminating it with white light. The recombination lifetime after deactivation is found to be stable under illumination at room temperature. The deactivation process is shown to be thermally activated with an activation energy of 0.7 eV. Based on the experimental findings, a defect reaction model is proposed explaining the deactivation of the boron–oxygen center. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mass spectrometry analysis of terpene lactones in Ginkgo biloba
Authors: Ding Shujing , Dudley Ed , Song Qingbao , Plummer Sue , Tang Jiandong , Newton Russell P. , Brenton A. Gareth
Published: February 2008

Terpene lactones are a family of compounds with unique chemical structures, first recognised in an extract of Ginkgo biloba. The discovery of terpene lactone derivatives has recently been reported in more and more plant extracts and even food products. In this study, mass spectrometric characteristics of the standard terpene lactones in Ginkgo biloba were comprehensively studied using both an ion trap and a quadrupole time‐of‐flight (QTOF) mass spectrometer. The mass spectral fragmentation data from both techniques was compared to obtain the mass spectrometric fragmentation pathways of the terpene lactones with high confidence. The data obtained will facilitate the analysis and identification of terpene lactones in future plant research via the fragmentation knowledge reported here. Copyright © 2008 John Wiley & Sons, Ltd.
Efficient adaptive designs with mid‐course sample size adjustment in clinical trials
Authors: Bartroff Jay , Lai Tze Leung
Published: February 2008

Adaptive designs have been proposed for clinical trials in which the nuisance parameters or alternative of interest are unknown or likely to be misspecified before the trial. Although most previous works on adaptive designs and mid‐course sample size re‐estimation have focused on two‐stage or group‐sequential designs in the normal case, we consider here a new approach that involves at most three stages and is developed in the general framework of multiparameter exponential families. This approach not only maintains the prescribed type I error probability but also provides a simple but asymptotically efficient sequential test whose finite‐sample performance, measured in terms of the expected sample size and power functions, is shown to be comparable to the optimal sequential design, determined by dynamic programming, in the simplified normal mean case with known variance and prespecified alternative, and superior to the existing two‐stage designs and also to adaptive group‐sequential designs when the alternative or nuisance parameters are unknown or misspecified. Copyright © 2008 John Wiley & Sons, Ltd.
The chick embryo as a model for intrauterine ultrasound‐guided heart intervention
Authors: Fechner S. , Busch C. , Oppitz M. , Drews U. , Meyer‐Wittkopf M.
Published: February 2008

Objectives

Prenatal minimally invasive therapy represents a challenging option for reducing long‐term complications of pathological fetal heart development. Here, the potential of the chick embryo as a model for ultrasound‐guided intrauterine cardiac intervention is explored.

Methods

Chick embryos were incubated for 18 days in fenestrated eggs and their hearts were punctured in ovo under ultrasound guidance. Indian ink and Nile blue sulfate were applied to mark the injection channel. After cardiac intervention, embryos were further incubated and subsequently sacrificed for macroscopic and histological evaluation of the heart.

Results

Stereomicroscopic analysis revealed that the catheter had successfully penetrated the cardiac ventricular wall in 26/38 embryos. The myocardium was not severely injured. Histological evaluation showed that the myocardium had almost reoccluded after the intervention and that the injection channel was clogged with fibrin. In one case, the embryo was not sacrificed, but was removed from the egg 24 h after the intervention, with no signs of cardiac dysfunction, and was followed up for 6 months.

Conclusions

Intrauterine ultrasound‐guided heart intervention in the human fetus can be simulated in the chick embryo. Fenestrated eggs have to be used because the egg shell and shell membrane are impermeable to ultrasound. Copyright © 2008 ISUOG. Published by John Wiley & Sons, Ltd.
Prevalence of feline haemotropic mycoplasmas in convenience samples of cats in Germany
Authors: Bauer Natali , Balzer Hans-Jörg , Thüre Sibylle , Moritz Andreas
Published: February 2008

The aim of this prospective study was to evaluate the prevalence of feline haemotropic mycoplasmas in Germany, to determine probable risk factors for these infections and to compare the diagnostic value of microscopic examination of blood smears to polymerase chain reaction (PCR). For the prevalence study, convenience samples (Ethylene diamine-tetraacetic acid (EDTA) blood) from 262 (64.5% male and 35.5% female) cats were included. A PCR for the detection of Mycoplasma haemofelis (MHF) and ‘ Candidatus Mycoplasma haemominutum’ (CMH) as well as a feline leukaemia virus (FeLV)/feline immunodeficiency virus (FIV) enzyme-linked immunoassay was performed. Blood smears from 224 cats were examined and the sensitivity and specificity of the microscopic diagnosis were determined. The prevalence of CMH, MHF, and CMH/MHF co-infection was 22.5%, 4.5%, and 0.8%, respectively. CMH was significantly associated with male gender ( P=0.047), older age ( P=0.0015) and both FeLV ( P=0.002) and FIV infections ( P<0.0001). However, there was no association between the presence of anaemia and CMH/MHF infection. The respective sensitivity and specificity of the microscopic diagnosis were 10.3% and 87.1% for a CMH infection and 0.0% and 98.0% for MHF infection.
Shell partitioning of two sympatric hermit crabs, Pagurus middendorffii and P. brachiomastus, in north-eastern Hokkaido, Japan
Authors: Oba Takashi , Wada Satoshi , Goshima Seiji
Published: February 2008

The distribution, reproductive biology and shell utilization pattern of two sympatric hermit crab species in Akkeshi, north-eastern Hokkaido, were examined. Although spatial distributions of Pagurus middendorffii and P. brachiomastus highly overlapped and their body sizes were similar, their shell utilization and breeding season markedly differed. Since interspecific differences in the shell utilization pattern agreed with the experimentally determined shell preference difference, we conclude that the interspecific difference in shell preference results in the shell utilization patterns observed in the field. The interspecific difference in the reproductive period, shell utilization pattern and shell preference are concluded to be factors that allow the coexistence of the two Pagurus species in Akkeshi. This study is an example of resource partitioning by coexisting hermit crabs.
Ceratothoa collaris(Isopoda: Cymothoidae) new to the eastern Mediterranean, with a redescription and comments on its distribution and host specificity
Authors: Bariche Michel , Trilles Jean-Paul
Published: February 2008

Ceratothoa collarisis reported for the first time outside its known geographical range, which was restricted to north-western African coasts (from Senegal to Tunisia). Many specimens of different developmental stages were collected off the Lebanese coast in the eastern Mediterranean. In addition to an update of the geographical range, synonymy and host specificity, an accurate redescription of the species is given on the basis of new and old materials.
Small-scale variation within a Modiolus modiolus (Mollusca: Bivalvia) reef in the Irish Sea. II. Epifauna recorded by divers and cameras
Authors: Sanderson W.G. , Holt R.H.F. , Kay L. , Ramsay K. , Perrins J. , McMath A.J. , Rees E.I.S.
Published: February 2008

The spatial heterogeneity of epifauna on a Modiolus modiolus reef off north-west Wales was investigated using divers. The community associated with these horse mussels was similar to that described previously from Loch Creran and the north basin of Strangford Lough. Some differences in epifauna may be attributable to the less sheltered nature of the site. Modiolus modiolus numbers and the associated epifaunal community were significantly different between ridge and trough sub-habitats. Troughs can be considered ‘reduced’ ridge communities whereas ridges have high densities of horse mussels and certain sessile taxa were correlated with their abundance. Modiolus modiolus aggregation as a competitive response to the feeding environment, enhanced food availability on ridges and sediment deposition amongst mussel clumps may start to explain the undulating bed-form. Patchiness in community composition and periodic cover by ophuroids has implications when considering the monitoring of the horse mussel community. Stratified, in situ recording of the highly populated ridges could improve the statistical sensitivity of monitoring horse mussel reefs whilst simultaneously focusing on the more sensitive indicators of fishing threats.
Gut residence time in pelagic crustaceans
Authors: Ritz David A.
Published: February 2008

Gut residence time (GRT) is often reported to be extremely variable among crustaceans. In this study, GRT was measured in tethered mysids that were fed continuously, and appearance of the first faecal pellet was found to be quite consistent averaging 1.6 h. There was no significant difference between GRT in those mysids held singly and those accompanied by free-swimming conspecifics, even though previous studies have shown metabolic benefits in social behaviour. Gut residence time data from a range of pelagic crustaceans feeding continuously showed a clear linear relationship with size. It appears that, when feeding ceases and crustaceans are allowed to clear their guts in filtered water, GRT can be very long and variable. However, when feeding is continuous, GRT can be relatively short and consistent.
Reproductive ecology of the pedunculate barnacleScalpellum stearnsii(Cirripedia: Lepadomorpha: Scalpellidae)
Authors: Ozaki Yuki , Yusa Yoichi , Yamato Shigeyuki , Imaoka Tohru
Published: February 2008

The sexuality of large (non-dwarf) individuals and the characteristics of eggs, larvae and dwarf males were investigated in the pedunculate barnacleScalpellum stearnsii. All 103 large individuals collected in this study were not hermaphrodites but females. The major length axis of the egg was on average 0.50 mm, which was larger than that in most thoracican barnacles with planktotrophic larvae. The larvae hatched as nauplii and metamorphosed into cyprids without feeding (i.e. lecithotrophic development). There was a positive relationship between body weight and egg mass weight in ovigerous females. The number of males attached per female ranged from 0 to 35 (average: 5.9) and there was a positive relationship between the number of males and female body weight. The distribution of dwarf males was skewed significantly towards the lower part of the occludent margin, which is near the fertilization site.
Decrease in Lithothamnion sp. (Rhodophyta) primary production due to the deposition of a thin sediment layer
Authors: Riul Pablo , Targino Carlos Henrique , Farias Julyana Da Nóbrega , Visscher Pieter Teunis , Horta Paulo Antunes
Published: February 2008

Coralline algae are important reef-builders which can form nodules, known as rhodoliths, occurring worldwide in beds sustaining a high biodiversity. Although considered a non-renewable resource, they are exploited as a source of calcium carbonate used mainly for agricultural purposes. In Brazil between 96,000 and 120,000 metric tonnes of rhodoliths are extracted per year. Besides the direct impact caused by removal on the coralline bed, the dredge process may also produce a plume of fine sediment, which can change the primary production of the remaining organisms. In this study, four treatments, with three replicates, were used to acquire Lithothamnion sp. net photosynthetic rates with and without a sediment layer using a Clark-type oxygen microelectrode and micromanipulator. The results demonstrated that, under controlled conditions, the addition of a thin sediment layer resulted in a 30% reduction of the irradiance, decreasing the Lithothamnion sp. net production in 70%. For this reason direct and indirect effects of mechanical exploitation of the rhodolith beds should be included in future studies that focus on environmental impacts of dredging activity, whether it is linked to the extraction of these algae.
Gametogenic cycle of the smooth clam Callista chione on the south-western coast of Portugal
Authors: Moura P. , Gaspar M.B. , Monteiro C.C.
Published: February 2008

The gametogenic cycle of the smooth clam Callista chione off the Arrábida region was studied throughout a 17-month period (from January 2004 to May 2005) using standard histological techniques, mean oocyte diameters and a condition index. This species showed a synchronism between sexes both in terms of gametogenic development and spawning. The results indicated that sex-ratio was not significantly different from parity. In January 2004, the gametogenic cycle had already begun and ended in late October 2004. Three spawning peaks were detected: January–March, April–May and August–October. No resting period was observed and a new gametogenic cycle began in early November, immediately after the spawning period. The analysis of the oocyte diameter enabled predicting the main spawning periods, which appear to be largely governed by seawater temperature. The condition index evolved according to the reproductive cycle of the species, with the highest values being observed prior to the main spawning periods. The size at first maturity estimated for C. chione was 50.81 mm.
Gandhi and the Emergence of the Modern Indian Political Canon
Authors: Parel Anthony J.
Published: February 2008

This article explores Mahatma Gandhi's contributions towards the evolution of the modern Indian political canon. Beginning with the Arthasastra, classical India had a political canon of its own. It flourished for over a millennium, but it suffered near extinction with the introduction in the nineteenth century of the Western political canon by the colonial state. Gandhi in the twentieth century intervened and challenged the dominance of the Western canon. He updated the old canon by deleting what was obsolete in it, preserving what was viable, and adding to it what was new and modern.
The “Axial Period”: What Was It and What Does It Signify?
Authors: Black Antony
Published: February 2008

Karl Jaspers coined the term the “axial period” to refer to what he saw as the simultaneous development in several different and separate societies—China, India, Iran, Israel, Greece—of “a new departure within mankind.” What he meant has been characterized as “a kind of critical, reflective questioning of the actual and a new vision of what lies beyond.” While it is true that people in each of these separate cultures began to develop new ways of talking about the cosmos, ethics, and community, Jaspers's approach and description of these phenomena were, I shall argue, highly defective. This has led to serious misunderstandings of what was involved.
Linguistics for Archaeologists: a Case-study in the Andes
Authors: Heggarty Paul
Published: February 2008

In the previous issue of CAJ, Heggarty (2007) set out how certain key principles and methods of historical linguistics can be exploited to open up another window on the past, from a perspective quite different and complementary to that offered by the archaeological record. Following this up, we turn here to an ideal case-study for exploring how the various patterns in linguistic (pre-)histories can be matched with their most plausible correlates in the archaeological data. Beyond our initial illustration of the Incas we now look further afield, to set the sequence of major civilizations of the Andes into its linguistic context, tracing the expansion trajectories of the main Andean language families further back in time, stage by stage, ultimately to their most plausible original homelands. The linguistic story emerges starkly at odds with assumptions widely held among archaeologists of the region. Indeed we encounter a paradigm case of how only a radical rethinking can reconcile our two disciplines' findings into a single, coherent, holistic prehistory for a human population — in the Andes, a prize now tantalizingly within our reach.
Introduction
Authors: Robb John
Published: February 2008

Time and change have been among the most widely discussed themes in archaeological theory, though they have varying fortunes in the vicissitudes of academic life. British and American anthropology, it has been observed, have long oscillated between history and evolution, between studying culture in its local context and in a long-term narrative. Following Steward and White rather than Kroeber and Boas, the New Archaeology's banner was evolution, and many of its theoretical goals were explicitly reductionist, for example, in viewing human actions as a local response to large-scale environmental conditions. Yet, at the same time, from its inception the New Archaeology also contained the seeds of a humanistic, historical approach (for instance, in tracing social stratification to chiefly power strategies to local, short-term political contexts).
The Timing and Tempo of Change: Examples from the Fourth Millennium cal. bc in Southern England
Authors: Whittle Alasdair , Bayliss Alex , Healy Frances
Published: February 2008

Generation after generation, life after life, human existence flows through time. Person to person, community to community, the relationships of social existence spread out in space. Archaeology has come up with many different approaches to the central questions of temporality and sociality, but it has not been very successful with either.
Star Performances and Cosmic Clutter
Authors: Pauketat Timothy R. , Emerson Thomas E.
Published: February 2008

Are there long-term processes invisible over short spans? And if so, how might they relate to the loci of long-term social change, those performative or practical moments wherein agents enact, embody, or otherwise engage traditions, landscapes, or structures? Here, we are particularly concerned with the experience of starry skies as these were historically reckoned through cluttered object fields and cosmic events. These are key to understanding the emergent properties of ethnoastronomies and cultural landscapes that, in certain moments, may be described as leading to historical conjunctures.
The Archaeology of Liberty in an American Captial: Excavations in Annapolis
Authors: Leone Mark P. , Armstrong Douglas V. , Marshall Yvonne , Smith Adam T.
Published: February 2008

Over the last two decades, there has been increasing attention to community archaeology, an archaeology which acknowledges the impact of archaeological research upon the communities among which it is conducted. Doing fieldwork has tangible effects upon the people we work among: archaeologists provide employment, spend money locally, negotiate local power structures, provide exotic connections, and, not least, change the landscape of knowledge by helping local people understand more or different things about their ancestors and about their own historical identity. While this is true worldwide, within American Historical Archaeology this strand of research has converged with a tradition of sophisticated materialist analysis highlighting not only class domination but also resistance and the persistence of alternative practices, ideologies and identities. A key element of this archaeology is public participation in the process of revealing a past of domination, struggle and resistance. The result is an archaeology which aspires not only to revise traditionally endorsed accounts of American history, but also to be an activist archaeology.

Mark Leone began this line of activist, participatory historical archaeology many years ago in Annapolis, and many of the scholars currently contributing to this body of work have been trained or inspired by this project. In The Archaeology of Liberty in an American Capital, Leone summarizes twenty-five years of research at Annapolis.

The Archaeology of Liberty in an American Capital: Excavations in Annapolis has received the Society for Historical Archaeology's James Deetz Book Award for 2008.
Development of a bathymetric grid for the Gulf of Papua and adjacent areas: A note describing its development
Authors: Daniell James J.
Published: February 2008

A new bathymetric grid for the Gulf of Papua and northern Australia was produced for the area 140°–150°E, 6°–14°S, with a 3.6″ (∼110 m) cell size. New multibeam sonar surveys have added much needed detail to a region of the seabed where previously little was known. In shallow Australian waters, bathymetry derived from Landsat satellite imagery was used to supplement traditionally acquired bathymetric data. For onshore areas, Shuttle Radar Topography Mission data were used for topographic control. The final grid revealed numerous features not observed in previous compilations of bathymetric data for the region. Bathymetric surveys on the continental shelf revealed an incised shelf with highly variable valley morphology. Prograding clinoforms are infilling valleys on the continental shelf and mark the seaward extension of the Fly River delta. A linear, relict shelf‐edge barrier marks the shelf break in the northern Ashmore Trough region, elsewhere the shelf break is scalloped and incised by canyons. Large mass transport deposits are widespread on the continental slope and indicate regions where mass wasting is common.
Biogeochemical legacy of prescribed fire in a giant sequoia–mixed conifer forest: A 16‐year record of watershed balances
Authors: Engle Diana L. , Sickman James O. , Moore Claudette M. , Esperanza Annie M. , Melack John M. , Keeley Jon E.
Published: February 2008

The effects of prescription burning on watershed balances of major ions in mixed conifer forest were examined in a 16‐year paired catchment study in Sequoia National Park, California. The objective was to determine whether fire‐related changes in watershed balances persist as long as estimated low‐end natural fire‐return intervals (≤10 years), and whether cumulative net export caused by fire could deplete nutrient stocks between successive fires. Inputs (wet + dry deposition) and outputs (stream export) of N, S, Cl−, HCO3−, Ca2+, Mg2+, Na+, K+, H+, and SiO2 were measured for 7 years preceding, and 9 years following, a prescribed burn of one of the catchments. After fire, runoff coefficients increased by 7% (in dry years) to 35% (in wet years). Inorganic N was elevated in stream water for 3 years after fire. Increased export of water, SO42−, Cl−, SiO2, and base cations continued through the end of the study. Pools and processes attributed to fire led to the cumulative loss, per hectare, of 1.2 kg N, 16 kg S, 25 kg Cl−, 130 kg Ca2+, 19 kg Mg2+, 71 kg Na+, 29 kg K+ and 192 kg Si, above that predicted by prefire regression equations relating export in the paired catchments. This additional export equaled <1% of the N, up to one‐third of the Ca and Mg, and up to three‐fourths of the K, contained in the forest floor prior to combustion. Changes in watershed balances indicated that low‐end natural fire‐return intervals may prevent complete reaccumulation of several elements between fires.
Regional channelized transport in fractured media with matrix diffusion and linear sorption
Authors: Odén Magnus , Niemi Auli , Tsang Chin‐Fu , Öhman Johan
Published: February 2008

A regional‐scale solute transport model with long‐range flow channeling is used to study the effect of matrix diffusion and linear sorption on channelized transport. We start from a fracture‐network‐based block model to build up a large‐scale flow and transport model with regional flow channeling, and then incorporate the processes of matrix diffusion and linear sorption. Regional‐scale solute transport is then studied by applying the model to the fracture data set from Sellafield, England. The results demonstrate the significant impact that matrix diffusion has on regional‐scale solute travel times for different degrees of long‐range channeling. With no channeling, a relatively sharp and significantly delayed arrival can be observed, which is the well‐known retardation effect of matrix diffusion and linear sorption. However, with increasing regional channeling the delay becomes much smaller while the spread of transit times becomes much larger. The solute breakthrough curves obtained are analyzed with both the traditional advection‐dispersion equation (ADE) and a Continuous Time Random Walk (CTRW) method developed for non‐Fickian transport. The low β values obtained from the CTRW model indicate an extremely non‐Fickian transport, which is also confirmed by the low Peclet numbers (much less than 1) required for the best fit to the ADE model. In particular, the times for the first arrival of solute are much earlier when regional channeling occurs. In other words, the degree of large‐scale channeling is a crucial parameter for determining the first arrival of particles, and it becomes even more important when matrix diffusion and linear sorption are included in the model.
Field observations of the ocean‐atmosphere exchange of ammonia: Fundamental importance of temperature as revealed by a comparison of high and low latitudes
Authors: Johnson Martin T. , Liss Peter S. , Bell Thomas G. , Lesworth Timothy J. , Baker Alex R. , Hind Andrew J. , Jickells Timothy D. , Biswas Karabi F. , Woodward E. Malcolm S. , Gibb Stuart W.
Published: February 2008

Simultaneous measurements of NH3 in the atmosphere and NH4+ in the ocean are presented from fieldwork spanning 10 years and 110 degrees of latitude, including the first such simultaneous measurements in the remote marine environment at >55°N. At high latitudes, fluxes were almost exclusively from air to sea, in contradiction with previous lower‐latitude studies, which have suggested that the open oceans are predominantly sources of ammonia to the atmosphere. Sensitivity analysis demonstrates that the direction and magnitude of the ocean‐atmosphere NH3 exchange is highly dependent on water temperature. This temperature effect is sufficiently strong to outweigh the effects of variability in concentrations in seawater and atmosphere in many parts of the (open) ocean. This is highlighted in data from the Atlantic oligotrophic gyres, where fluxes were found to be predominantly out of the ocean despite extremely low dissolved ammonium concentrations in surface waters.
Short‐term dissolution response of pelagic carbonate sediments to the invasion of anthropogenic CO2: A model study
Authors: Gehlen M. , Bopp L. , Aumont O.
Published: February 2008

This study addresses the potential for and the quantification of dissolution of marine calcium carbonate (CaCO3) sediments occurring on century timescales in response to the invasion of anthropogenic CO2. It presents results obtained with the global biogeochemical model PISCES interactively coupled to a global sediment model. The latter represents the principal reactions involved in early diagenesis of biogenic opal, CaCO3, and organic matter. The model reproduces observed distributions of core top CaCO3 content and bottom water carbonate chemistry (e.g., [CO32−]). Starting from the climatological state, a model experiment is carried out according to the standard CMIP scenario of atmospheric pCO2 increasing at a rate of 1% per year from 286 to 1144 ppm over a 140 year time period. The invasion of anthropogenic CO2 results in a strong decrease in bottom water [CO32−] reaching −100 μM in areas of deep water formation in the North Atlantic and mode and intermediate water formation in the Southern Hemisphere. The concomitant decrease in calcite saturation state of bottom waters drives the dissolution of CaCO3. The absolute CaCO3 content averaged over the top first centimeter decreases by up to 6%, while the change in advection calculated at the base of the bioturbated layer (10 cm) is indicative of net erosion. The predicted changes in bottom water chemistry are discussed in terms of their potential impact on benthic communities.
Biogenic versus anthropogenic sources of CO in the United States
Authors: Hudman R. C. , Murray L. T. , Jacob D. J. , Millet D. B. , Turquety S. , Wu S. , Blake D. R. , Goldstein A. H. , Holloway J. , Sachse G. W.
Published: February 2008

Aircraft observations of carbon monoxide (CO) from the ICARTT campaign over the eastern United States in summer 2004 (July 1–August 15), interpreted with a global 3‐D model of tropospheric chemistry (GEOS‐Chem), show that the national anthropogenic emission inventory from the U.S. Environmental Protection Agency (93 Tg CO y−1) is too high by 60% in summer. Our best estimate of the CO anthropogenic source for the ICARTT period is 6.4 Tg CO, including 4.6 Tg from direct emission and 1.8 Tg CO from oxidation of anthropogenic volatile organic compounds (VOCs). The biogenic CO source for the same period from the oxidation of isoprene and other biogenic VOCs is 8.3 Tg CO, and is independently constrained by ICARTT observations of formaldehyde (HCHO). Anthropogenic emissions of CO in the U.S. have decreased to the point that they are now lower than the biogenic source in summer.
Diurnal warm‐layer events in the western Mediterranean and European shelf seas
Authors: Merchant C. J. , Filipiak M. J. , Le Borgne P. , Roquet H. , Autret E. , Piollé J.‐F. , Lavender S.
Published: February 2008

We characterize near‐surface ocean diurnal warm‐layer events, using satellite observations and fields from numerical weather forecasting. The study covers April to September, 2006, over the area 11°W to 17°E and 35°N to 57°N, with 0.1° cells. We use hourly satellite SSTs from which peak amplitudes of diurnal cycles in SST (dSSTs) can be estimated with error ∼0.3 K. The diurnal excursions of SST observed are spatially and temporally coherent. The largest dSSTs exceed 6 K, affect 0.01% of the surface, and are seen in the Mediterranean, North and Irish Seas. There is an anti‐correlation between the magnitude and the horizontal length scale of dSST events. Events wherein dSST exceeds 4 K have length scales of ≤40 km. From the frequency distribution of different measures of wind‐speed minima, we infer that extreme dSST maxima arise where conditions of low wind speed are sustained from early morning to mid afternoon.
Magnetic field structure of Saturn's dayside magnetosphere and its mapping to the ionosphere: Results from ring current modeling
Authors: Bunce E. J. , Arridge C. S. , Cowley S. W. H. , Dougherty M. K.
Published: February 2008

Ring current modeling in Saturn's magnetosphere using Pioneer‐11, Voyager, and Cassini data has shown that the size and strength of the current system grows with the extension of the magnetosphere, governed by the solar wind dynamic pressure. Here we show that the consequent middle magnetosphere field is quasi‐dipolar in form when the magnetosphere is strongly compressed, but extends into a magnetodisc when it is strongly expanded. We also show that the region occupied by the modeled ring current corresponds to an essentially fixed shell of field lines that expands and contracts with the size of the system, thus mapping to an almost fixed co‐latitude range in Saturn's ionosphere, between ∼14° and ∼20° in the northern hemisphere, and ∼16° and ∼22° in the southern hemisphere. The median dayside UV auroral oval is found to map from near the poleward edge of the modeled ring current toward the boundary of open field lines at smaller co‐latitudes. In the equatorial plane this corresponds to a layer ∼2–5 Saturn radius wide (depending on magnetosphere size), extending from near the outer edge of the ring current to the vicinity of the magnetopause.
A leaping, triggered sequence along a segmented fault: The 1951ML7.3 Hualien‐Taitung earthquake sequence in eastern Taiwan
Authors: Chen Kate Huihsuan , Toda Shinji , Rau Ruey‐Juin
Published: February 2008

As the most destructive seismic episode ever known in eastern Taiwan, the 1951ML7.3 Hualien – Taitung earthquake series consisted of sequential ruptures along four distinct fault segments. It provides a good opportunity to study earthquake triggering processes along an active fault at an oblique arc‐continent collision boundary. This sequence initiated on 21October 1951 with theML7.3 Hualien main shock and a group ofM6+ aftershocks nearby. TheML6.0 Chihshang earthquake occurred 34 days later and 100 km away from the main shock. TheML7.3 Yuli earthquake followed 3 m later and 5 km away from the Chihshang event. Two days later, theML6.0 Taitung earthquake shocked a region 40 km away from the precedingM6 event and completed the sequence. The first triggered rupture outside the main shock area did not occur on the nearby Yuli fault segment but occurred 100 km away at the Chihshang fault. Calculations of static Coulomb stress change show that most of the major aftershocks were located in areas of enhanced static stress change. However, the stress transfer alone cannot explain triggering across 100 km. With the rate/state stress transfer model, we computed the temporal order of encouraged ruptures on different segments along the collision boundary. The results show that 34 days following the major shocks in Hualien, the Chihshang segment had a higherM6+ (M≧ 6) earthquake probability due to its significantly higher (at least an order of magnitude) background seismicity rate than the other two segments. After the Chihshang event, the rate/state model predicted a higherM6+ earthquake probability in the Yuli segment, also matching the observation. In this case, the Yuli segment was triggered ahead of the Taitung segment because of its larger increase in Coulomb stress change.
Methanotrophic bacteria occupy benthic microbial mats in shallow marine hydrocarbon seeps, Coal Oil Point, California
Authors: Ding Haibing , Valentine David L.
Published: February 2008

Microbial mats composed of giant sulfur bacteria are observed throughout the benthos along continental margins. These communities serve to oxidize dissolved sulfides to sulfate, and are typically associated with the recent exposure of sulfide‐rich sediments. Such mats are also ubiquitous in areas of hydrocarbon seepage, where they are thought to consume sulfide generated in underlying sediment. Despite the high abundance of dissolved methane in hydrocarbon seeps, few studies have considered the importance of methanotrophy in mat communities. To assess the importance of methanotrophs in microbial mats from hydrocarbon seeps, an approach involving lipid biomarkers, stable isotopes and enrichment culturing was applied. Microbial mat samples were collected from benthic surfaces at two hydrocarbon seeps located in the Coal Oil Point seep field, offshore from Goleta, California. Both samples display a high abundance of 16:1 fatty acids, including two isomers specific to type I methanotrophic bacteria, 16:1(ω8) and 16:1(ω6). Depleted values of δ13C found in 16:1 fatty acids suggests methane assimilation into biomass, whereas three separate investigations of sulfide‐oxidizing bacteria yield fractionation factors too small to account for these values. On the basis of these observations and experiments, an isotope mass balance was applied to fatty acids present in the microbial mat samples which indicates methanotrophs contribute up to 46% of total fatty acids. These results implicate methanotrophy as an important function for microbial mats in seep areas, despite the visual appearance of these mats as being composed of giant sulfur bacteria.
Afterglow mode and the new micropulsed beam mode applied to an electron cyclotron resonance ion source
Authors: Maunoury L. , Adoui L. , Grandin J. P. , Noury F. , Huber B. A. , Lamour E. , Prigent C. , Rozet J. P. , Vernhet D. , Leherissier P. , Pacquet J. Y.
Published: February 2008

An increasing number of experiments in the field of low energy ion physics (<25keV/charge) requires pulsed beams of highly charged ions. Whereas for high-intensity beams (greater than microampere) a pulsed beam chopper, installed downstream to the analyzing dipole, is used. For low-intensity beams (<100nA) the ion intensity delivered during the pulse may be increased by operating the electron cyclotron resonance discharge in the afterglow mode. This method gives satisfactory results (i.e., average current during the beam pulse is higher than the current in the cw mode) for high charge state ions. In this paper, we report on results of the afterglow mode for beams of Neq+22, Arq+36, and Krq+84 ions. Furthermore, a new promising “micropulsed beam” mode will be described with encouraging preliminary results for Kr27+84 and Ar17+36 ions.
The negative hydrogen Penning ion gauge ion source for KIRAMS-13 cyclotron
Authors: An D. H. , Jung I. S. , Kang J. , Chang H. S. , Hong B. H. , Hong S. , Lee M. Y. , Kim Y. , Yang T. K. , Chai J. S.
Published: February 2008

The cold-cathode-type Penning ion gauge (PIG) ion source for the internal ion source of KIRAMS-13 cyclotron has been used for generation of negative hydrogen ions. The dc H-beam current of 650μA from the PIG ion source with the Dee voltage of 40kV and arc current of 1.0A is extrapolated from the measured dc extraction beam currents at the low extraction dc voltages. The output optimization of PIG ion source in the cyclotron has been carried out by using various chimneys with different sizes of the expansion gap between the plasma boundary and the chimney wall. This paper presents the results of the dc H-extraction measurement and the expansion gap experiment.
Multicharged iron ions produced by using induction heating vapor source
Authors: Kato Yushi , Kubo Takashi , Muramatsu Masayuki , Tanaka Kiyokatsu , Kitagawa Atsushi , Yoshida Yoshikazu , Asaji Toyohisa , Sato Fuminobu , Iida Toshiyuki
Published: February 2008

Multiply charged Fe ions are produced from solid pure material in an electron cyclotron resonance (ECR) ion source. We develop an evaporator by using induction heating with an induction coil which is made of bare molybdenum wire partially covered by ceramic beads in vacuum and surrounding and heating directly the pure Fe rod. Heated material has no contact with insulators, so that outgas is minimized. The evaporator is installed around the mirror end plate outside of the ECR plasma with its hole grazing the ECR zone. Helium or argon gas is usually chosen for supporting gas. The multicharged Fe ions up to Fe13+ are extracted from the opposite side of mirror and against the evaporator, and then multicharged Fe ion beam is formed. We compare production of multicharged iron ions by using this new source with our previous methods.
Direct current H− source for boron neutron capture therapy tandem accelerator
Authors: Belchenko Yu. , Sanin A. , Gusev I. , Khilchenko A. , Kvashnin A. , Rashchenko V. , Savkin V. , Zubarev P.
Published: February 2008

One year experience of dc H− source operation at 2MeV tandem accelerator is described. The source delivers H− ion beams with controlled current in the range of 1–8mA and energy up to 25keV. Normalized 1rms emittance for 8mA beam is less than 0.2πmmmrad. Negative ions are produced on the cesiated anode of the Penning discharge, driven by plasma injection from the hollow cathode inserts.
High intensity production of high and medium charge state uranium and other heavy ion beams with VENUS
Authors: Leitner D. , Galloway M. L. , Loew T. J. , Lyneis C. M. , Castro Rodriguez I. , Todd D. S.
Published: February 2008

The next generation, superconducting electron cyclotron resonance (ECR) ion source VENUS (versatile ECR ion source for nuclear science) started operation with 28GHz microwave heating in 2004. Since then it has produced world record ion beam intensities. For example, 2850eμA of O6+, 200eμA of U33+ or U34+, and in respect to high charge state ions, 1eμA of Ar18+, 270eμA of Ar16+, 28eμA of Xe35+, and 4.9eμA of U47+ have been produced. A brief overview of the latest developments leading to these record intensities is given and the production of high intensity uranium beams is discussed in more detail.
Off-line ion source terminal for ISAC at TRIUMF
Authors: Jayamanna K. , Ames F. , Cojocaru G. , Baartman R. , Bricault P. , Dube R. , Laxdal R. , Marchetto M. , MacDonald M. , Schmor P. , Wight G. , Yuan D.
Published: February 2008

The off-line ion source (OLIS) terminal consists of a microwave cusp ion source, either a surface ion source or a hybrid surface-arc discharge ion source and an electrostatic switch that allows selecting any one of the sources without mechanical intervention. These sources provide variety of beams to ISAC experiments, for commissioning the accelerators, for setting up the radioactive experiments, and for tuning the beam lines. The microwave ion source has been operational since 1995 and provides singly and doubly charged beams from various stable isotopes for many ISAC experiments at high and low energy areas. Originally its prime goal was to provide beams from gaseous elements, but later two ovens and a sputtering system were added in order to provide beams from liquids and from solids. The surface ion source installed in 2002 can provide low energy spread beams from alkali and semialkali elements. It also has three separate ovens and an ionizer. Therefore, it can provide three different temperature regions simultaneously to provide different beams to ISAC. It is mainly used for laser spectroscopy experiments and other experiments, which require a finite beam quality. A hybrid surface-arc discharge ion source was also developed and installed in order to meet specific demands from experiments. This source terminal is now automated for start up and for mass selection. It is capable of providing stable beams for months without maintenance and it is also capable of providing negative ion beams if required. To date, over 40 different isotopes including many rear isotopes were delivered to various experiments from the OLIS source terminal. Performances of the ion sources and some of the results are discussed.
Status of the PHOENIX electron cyclotron resonance charge breeder at ISOLDE, CERN
Authors: Barton Charles , Cederkall Joakim , Delahaye Pierre , Kester Oliver , Lamy Thierry , Marie-Jeanne Mélanie
Published: February 2008

We report here on the last progresses made with the PHOENIX electron cyclotron resonance charge breeder test bench at ISOLDE. Recently, an experiment was performed to test the trapping of Fe61 daughter nuclides from the decay of Mn61 nuclides. Preliminary results are given.
Study of pulsed electron cyclotron resonance ion source plasma near breakdown: The preglow
Authors: Thuillier T. , Lamy T. , Latrasse L. , Izotov I. V. , Sidorov A. V. , Skalyga V. A. , Zorin V. G. , Marie-Jeanne M.
Published: February 2008

A careful study of pulsed mode operation of the PHOENIX electron cyclotron resonance (ECR) ion source has clearly demonstrated the reality of an unexpected transient current peak, occurring at the very beginning of the plasma breakdown. This regime was named the preglow, as an explicit reference to the afterglow occurring at the microwave pulse end. After the transient preglow peak, the plasma regime relaxes to the classical steady state one. Argon preglow experiments performed at LPSC are presented. A theoretical model of ECR gas breakdown in a magnetic trap, developed at IAP, showing satisfactory agreement with the experimental results is suggested.
Measurement of plasma potential of liquid-He-free superconducting electron cyclotron resonance ion source
Authors: Higashijima H. , Takai W. , Nakagawa T. , Higurashi Y. , Kidera M. , Goto A.
Published: February 2008

The plasma potential of liquid-He-free superconducting electron cyclotron resonance ion source was measured as a function of minimum strength of mirror magnetic field (Bmin) and gas pressure with the method based on the retarding electric field. We observed that the plasma potential decreased with increasing Bmin up to 0.5T and then gradually increased again. The plasma potential increased with increasing gas pressure. When we add the O2 gas to the Ar plasma (gas mixing method), plasma potential gradually decreased with increasing the O2 gas pressure.
Prospects of ion beam extraction and transport simulations (invited)
Authors: Spädtke Peter , Tinschert K. , Lang R. , Mäder J. , Roßbach J. , Stetson J. W. , Celona L.
Published: February 2008

Beam profile measurements using viewing targets and emittance measurements with pepper pot devices have established new insights about the ion beam extracted from an electron cyclotron resonance ion source (ECRIS). In our measurements we have compared two different ECRISs of CAPRICE type, one source was equipped with a standard 1.0T hexapole magnet, whereas for the other ion source a stronger hexapole magnet with a flux density of 1.2T has been installed. The resulting ion beam profile for each individual charge state produced by different focal strengths of an optical element can be used to estimate the emittance, but it also shows the negative influence of the hexapole on the extracted ion beam. A hexapole correction would be desirable to improve further beam transport. A possible correction scheme will be discussed. All experimental observations can be reproduced by computer simulation if a magnetic plasma is assumed. When the Larmor radius for ions becomes small, collisions are negligible for the path of ions within the plasma. Low energy electrons are highly movable along the magnetic field lines and can compensate the ion space charge within the plasma chamber.
A generalization of the state-specific complete-active-space coupled-cluster method for calculating electronic excited states
Authors: Lyakh Dmitry I. , Ivanov Vladimir V. , Adamowicz Ludwik
Published: February 2008

The complete-active-space coupled-cluster approach with single and double excitations (CASCCSD) based on the ansatz of Oliphant and Adamowicz [J. Chem. Phys. 94, 1229 (1991); 96, 3739 (1992)] is used to derive an approach termed XCASCCSD for calculating potential energy surfaces of ground and excited electronic states with different multiplicities and symmetries. The XCASCCSD approach explicitly includes a procedure for spin and spatial orbital-momentum symmetry adaptation of the wave function that has allowed us to consider states with degenerate formal references. The XCASCCSD method is applied to calculate potential energy surfaces of the ground and some lowest singlet and triplet excited states of the FH and C2 molecules. Some states of C2 are known to have a very strong “multireference” character making their description difficult with single-reference methods. The problem of the change of the formal reference determinant along the potential energy surface is discussed. Also, vertical excitation energies of formaldehyde calculated with the XCASCCSD approach are presented.
The effect of magnetic field annealing on single crystal iron gallium alloy
Authors: Yoo J.-H. , Restorff J. B. , Wun-Fogle M. , Flatau A. B.
Published: February 2008

In this study, we investigate magnetic field annealing of Fe82.5Ga17.5 single crystal disks with two easy axes ([100] and [010]) in the plane of the disk. Magnetic annealing was conducted with a high magnetic field (H>12kOe) applied along the [100] or [010] easy axes of the demagnetized, as-grown, slow-cooled sample. Strain measurements were recorded both before and after the magnetic annealing of the samples from a demagnetized state. After each annealing protocol, the resultant built-in uniaxial anisotropy constants were measured using torque magnetometry and also using an approach that calculates anisotropy based on magnetization curves. The built-in anisotropy constant after magnetic annealing strongly depends on annealing protocol. The calculated anisotropy constants determined for each sample show consistent trends for each annealing condition using the two different anisotropy measurement methods. The maximum uniaxial anisotropy constant was 4.24kJ∕m3 and the built-in effective prestress was −19.9MPa after field annealing.