bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of sample storage on quantitation of lipoprotein (a) by an enzyme‐linked immunosorbent assay
Authors: Evans Rhobert W. , Sankey Steadman S. , Hauth Beth A. , Sutton‐Tyrrell Kim , Kambon M. Ilyas , Kuller Lewis H.
Published: November 2006

This study evaluated the effect of storage on the quantitation of lipoprotein (Lp)(a) in 25 serum samples. Aliquots of serum were stored for up to three years at either −20°C or−70°C and Lp(a) subsequently analyzed using an enzyme‐linked immunosorbent assay kit. Concentrations of Lp(a) declined during storage, and the temperatures employed elicited significantly different (P<0.05) values within 12 mon which further diverged during three years of storage. Compared to baseline values, significant decreases (P<0.05) in Lp(a) levels were evident after six months of storage at−20°C with apparent losses (geometric mean) reaching 36.9% (95% confidence interval: 30.9%, 42.9%) after three years. Similarly, significantly lower (P<0.05) Lp(a) values were recorded after six months of storage at−70°C and at three years the decrease (geometric mean) was 19.1% (95% confidence interval: 14.3%, 24.0%). The losses, after three years, in terms of the arithmetic mean were 53.5 and 26.2% at−20 and−70°C, respectively. Phenotype analysis suggested that large isoforms are more susceptible to degradation than smaller moieties. This may be related to the observation that apparent losses are reduced in samples containing over 8 mg/dL Lp(a). Nevertheless, Lp(a) levels in stored samples retained a strong correlation with the baseline values. These results must be considered specific for the storage conditions and analytical procedures employed.
The sterols ofCucurbita moschata (“calabacita”) seed oil
Authors: Rodriguez Juan B. , Cros Eduardo G. , Bertoni Maria H. , Cattaneo Pedro
Published: November 2006

From the sterol fraction of seed oil from commercialCucurbita moschata Dutch (“calabacita”) Δ5 and Δ7 sterols having saturated and unsaturated side chain were isolated by chromatographic procedures and characterized by spectroscopic (1H and13C‐nuclear magnetic resonance, mass spectrometry) methods. The main components were identified as 24S‐ethyl 5α‐cholesta‐7,22E‐dien‐3β‐ol (α‐spinasterol); 24S‐ethyl 5α‐cholesta‐7,22E, 25‐trien‐3β‐ol (25‐dehydrochondrillasterol); 24S‐ethyl 5α‐cholesta‐7, 25‐dien‐3β‐ol; 24R‐ethylcholesta‐7‐en‐3β‐ol (Δ7‐stigmastenol) and 24‐ethyl‐cholesta‐7, 24(28)‐dien‐3β‐ol (Δ7,24(28)‐stigmastadienol).Lipids 31, 1205–1208 (1996).
Real‐time X‐ray powder diffraction investigations on cocoa butter. II. The relationship between melting behavior and composition of β‐cocoa butter
Authors: van Malssen Kees , Peschar René , Schenk Henk
Published: November 2006

The melting behavior of twelve different cocoa butter samples, in the β‐phase, has been investigated with real‐time X‐ray powder diffraction. The melting trajectory of each sample is characterized by three temperature values: a starting point, a point of maximum melting, and a point of complete melting. These points are determined by an analysis of the subsequent X‐ray diffraction patterns. A least‐squares analysis has been developed which allows the observed melting points to be related to the composition of the cocoa butter. This analysis shows that the melting behavior of cocoa butter can be described as a function of certain binary combinations of its major components.
Real‐time X‐ray powder diffraction investigations on cocoa butter. III. Direct β‐crystallization of cocoa butter: Occurrence of a memory effect
Authors: van Malssen Kees , Peschar René , Brito Claudia , Schenk Henk
Published: November 2006

Direct β‐crystallization of different samples of cocoa butter has been investigated. The influence of the thermal history of cocoa butter on its phase behavior is defined as a memory effect. The chemical composition of cocoa butter has been related to the occurrence of the short‐term β‐memory effectvia statistical analysis of the results. We explain how this effect can be attributed mainly to stearic acid and its related triacylglycerols. The total phase behavior of cocoa butter is discussed on the basis of the results obtained from the series of three papers of which this is the last.
Deacidification of black cumin seed oil by selective supercritical carbon dioxide extraction
Authors: Türkay Selma , Burford Mark D. , Kemal Sangün M. , Ekinci Ekrem , Bartle Keith D. , Clifford Anthony A.
Published: November 2006

The deacidification of high‐acidity oils from Black cumin seeds (Nigella sativa) was investigated with supercritical carbon dioxide at two temperatures (40 and 60°C), pressures (15 and 20 MPa) and polarities (pure CO2 and CO2/10% MeOH). For pure CO2 at a relatively low pressure (15 MPa) and relatively high temperature (60°C), the deacidification of a highacidity (37.7 wt% free fatty acid) oil to a low‐acidity (7.8 wt% free fatty acid) oil was achieved. The free fatty acids were quantitatively (90 wt%) extracted from the oil and left the majority (77 wt%) of the valuable neutral oils in the seed to be recovered at a later stage by using a higher extraction pressure. By reducing the extraction temperature to 40°C, increasing the extraction pressure to 20 MPa, or increasing the polarity of the supercritical fluid via the addition of a methanol modifier, the selectivity of the extraction was significantly reduced; the amount of neutral oil that co‐extracted with the free fatty acids was increased from 23 to 94 wt%.
Isolation of tocopherol and sterol concentrate from sunflower oil deodorizer distillate
Authors: Ghosh S. , Bhattacharyya D. K.
Published: November 2006

The isolation of tocopherols and sterols together as a concentrate from sunflower oil deodorizer distillate was investigated. The sunflower oil deodorizer distillate was composed of 24.9% unsaponifiable matter with 4.8% tocopherols and 9.7% sterols, 28.8% free fatty acid (FFA) and 46.3% neutral glycerides. The isolation technology included process steps such as biohydrolysis, bioesterification and fractional distillation. The neutral glycerides of the deodorizer distillates were hydrolyzed byCandida cylindracea lipase. The total fatty acids (initial FFA plus FFA from neutral glycerides) were converted into butyl esters withMucor miehei lipase. The esterified product was then fractionally distilled in a Claisen‐vigreux flask. The first fraction, which was collected at 180–230°C at 1.00 mm of Hg for 45 min, contained mainly butyl esters, hydrocarbons, oxidized products and some amount of free fatty acids. The fraction collected at 230–260°C at 1.00 mm Hg for 15 min was rich in tocopherols (about 30%) and sterols (about 36%). The overall recovery of tocopherols and sterols after hydrolysis, esterification and distillation were around 70% and 42%, respectively, of the original content in sunflower oil deodorizer distillate.
Low‐molecular weight organic compositions of acid waters from vegetable oil soapstocks
Authors: Johansen Steven L. , Sivasothy Arunthathi , Dowd Michael K. , Reilly Peter J. , Hammond Earl G.
Published: November 2006

Alkaline extracts (soapstocks) from canola, corn, cottonseed, peanut, soybean, and sunflower oil refining were acidified, and identities and concentrations of the low‐molecular weight organic components of the resulting acid waters were determined by gas chromatography, followed by mass spectroscopy, and by high‐performance liquid chromatography. The main components of each acid water sample, in order of decreasing concentration and after omitting the fermentation product lactic acid, were phosphoric acid, α‐glycerophosphate, and glycerol from canola;myo‐inositol, phosphoric acid, α‐glycerophosphate andmyo‐inositol‐1‐phosphate from corn; glycerol, α‐glycerophosphate,myo‐inositol‐1‐phosphate, and β‐glycerophosphate from cottonseed; phosphoric acid, glycerol, andmyo‐inositol from peanut; α‐glycerophospho‐1‐myo‐inositol,myo‐inositol‐1‐phosphate, α‐glycerophosphate, and glycerol from soybean; and α‐glycerophosphate, glycerol,myo‐inositol‐1‐phosphate, and β‐glycerophosphate from sunflower.
Determination of the identity of by‐products in the industrial production of saturated fatty acids
Authors: Skovly Joakim , Lundanes Elsa , Greibrokk Tyge
Published: November 2006

A technical product of saturated fatty acids has been analyzed to determine the structure of by‐products found in the C20–22 fatty acids manufactured from fish oil. Short‐path distillation of the weakly colored product provided a residue, which was extracted either by supercritical carbon dioxide or by acetone. Extracts and residues were analyzed by size‐exclusion chromatography, supercritical fluid chromatography, and by gas chromatography, the latter combined with mass spectrometry and Fourier‐transform infrared spectroscopy, and by nuclear magnetic resonance spectrometry. A series of homologs of fatty acid dimers was identified as lactone esters. Each homolog also contained several isomers with a varying number of carbon atoms in the two hydrocarbon chains of the dimers. Trimers, containing yellow components, were also present in small amounts, but the structure of the trimers has not been determined yet.
Oxidative stabilities of soybean oils that lack lipoxygenases
Authors: Shen N. , Fehr W. , Johnson L. , White P.
Published: November 2006

Lipoxygenase (LOX)‐null soybean lines that lack LOX 2, or LOX 2 and 3, and contain normal (8.0–8.6%) or low (2.0–2.8%) linolenate (18∶3) amounts were evaluated for their oil qualities and storage stabilities. Soybean oils of six genotypes were extracted by both laboratory‐scale and pilot‐plant systems and were refined, bleached, and deodorized in the laboratory. Citric acid was added to oils during the cool‐down stage of deodorization. Two replications, separated at the point of conditioning, were evaluated for each genotype. Under storage conditions of 55–60°C in the dark, soybean oils with low 18∶3 contents were significantly (P<‐0.05) more stable as measured by peroxide values than were oils with normal 18∶3 contents, regardless of the LOX content of the beans. The volatile analysis showed few differences between oils with low and high 18∶3 contents or among oils from beans that lack different LOX enzymes. After 16 d of storage, the amount of 1‐octen‐3‐ol was significantly greater in oils with low 18∶3 content, and soybean oils from beans with normal LOX content had a significantly (P<‐0.05) lower amount of 1‐octen‐3‐ol than did the oils that lacked LOX enzymes. Storage at 35°C under light showed no differences in volatile amounts or sensory evaluations after 14 d of storage. During storage, peroxide values tended to be lower in oils from beans with normal 18∶3 content and in oils from beans with normal LOX content. Generally, the abscence of LOX 2 or LOX 2 and 3, although having a small effect on lipid oxidation, was not as important to oil quality as was the 18∶3 content.
Entwicklung und Validierung einer Networkingskala
Authors: Wolff Hans-Georg , Moser Klaus
Published: November 2006

Zusammenfassung. Networking umschreibt ein Syndrom von Verhaltensweisen, die Personen zu Aufbau, Pflege und Nutzung sozialer Beziehungen im beruflichen Kontext zeigen. Die Relevanz des Konstrukts beruht auf dem vermuteten positiven Einfluss, den Networking auf den beruflichen Erfolg ausübt. In diesem Beitrag wird auf der Basis der psychologischen Literatur zu Networking und der soziologischen Literatur zu sozialem Kapital eine Networkingskala entwickelt und in insgesamt drei Studien werden Struktur und Validität der Skala geprüft. Die Ergebnisse von multidimensionaler Skalierung (Studie 1) und konfirmatorischer Faktorenanalyse (Studie 2) bestätigen die postulierte Binnendifferenzierung von Networking durch zwei Facetten, 1) internes vs. externes Networking sowie 2) Aufbau vs. Pflege vs. Nutzung von Kontakten. Durch die Kreuzung der Facetten entstehen sechs Subskalen, die sich zu einer Gesamtskala zusammenfassen lassen. Für die Skala ergeben sich diskriminante Zusammenhänge mit Maßen, die Größe und Constraint von sozialen Netzwerken beschreiben. Auf Seiten der Determinanten von Networking zeigen sich theoriekonforme Zusammenhänge mit Konstrukten, die den beruflichen Fokus von Networking (z.B. Karriereorientierung) sowie die soziale Komponente von Networking (z.B. Extraversion) belegen.
Erste Untersuchungen zur Kriteriums-Validität des I-S-T 2000R an Erwachsenen beiderlei Geschlechts
Authors: Steinmayr Ricarda , Amelang Manfred
Published: November 2006

Zusammenfassung. Eine Stichprobe von insgesamt N = 219 berufstätigen Personen beiderlei Geschlechts im Alter von durchschnittlich 34 Jahren bearbeitete das Grund- und Erweiterungsmodul (GM bzw. EM) des Intelligenz-Struktur-Tests 2000 R (IST; Amthauer et al., 2001 ) sowie den CFT 3 ( Cattell & Weiß, 1971 ). Auf siebenfach abgestuften Skalen beurteilten jeweils drei Bekannte, Freunde oder Verwandte jede der an der Untersuchung teilnehmenden Personen hinsichtlich ihres Allgemeinen Wissens sowie ihrer verbalen, numerischen und figuralen Fähigkeiten als Facetten der Allgemeinen Intelligenz; als weitere externe Kriterien lagen Maße für das Ausbildungsniveau und die ausgeübte Berufstätigkeit vor. In fast allen Skalen des IST, im CFT 3 sowie in den Fremdeinschätzungen lagen die Mittelwerte der Frauen unter denjenigen der Männer. Die höchsten Korrelationen des IST bestanden mit Koeffizienten um r = .60 gegenüber dem Kriterium “Ausbildungserfolg“; in ähnlicher Größenordnung korrelierte der IST mit der fremdeingeschätzten Allgemeinen Intelligenz. Mit dem “Sozialen Status“ der ausgeübten Berufstätigkeit bestanden Korrelationen um .50. Die vorliegenden Ergebnisse lassen den IST auch bei Erwachsenen als ein hinreichend valides Verfahren erscheinen.
Beurteilung von sozialen Verhaltensproblemen und Erziehungsschwierigkeiten im Vorschulalter
Authors: Beelmann Andreas , Lösel Friedrich , Stemmler Mark , Jaursch Stefanie
Published: November 2006

Zusammenfassung. Der Artikel beschreibt die psychometrische Überprüfung der deutschen Version des Eyberg Child Behavior Inventory (ECBI) an einer Stichprobe von 718 Vorschulkindern mit Angaben von 715 Müttern und 566 Vätern. Die Itemanalyse ergab eine große Bandbreite von mittleren Intensitäts- und Problemratings sowie überwiegend zufriedenstellende Trennschärfen und Interkorrelationen der 36 ECBI-Items. Die Überprüfung der ECBI-Skalen erbrachte gute und mit der US-amerikanischen Standardisierung vergleichbare Reliabilitäten (z.B. Cronbachs α .90). Dagegen zeigten sich zum Teil deutlich höhere Intensitäts- und Problemwerte in unserer deutschen Stichprobe, was auf kulturspezifische Antwortmuster hindeutet. Es bestätigte sich jedoch das Ergebnis, dass Mütter im Vergleich zu Vätern von höheren Problemraten berichteten und Jungen im Vergleich zu Mädchen fast durchgängig höhere Belastungswerte aufwiesen. Die Daten zur Validierung des Verfahren anhand des Social Behavior Questionnaire (SBQ) erbrachten innerhalb des gleichen Informanten substanzielle Zusammenhänge, aber nur geringe Korrelationen zwischen den Angaben unterschiedlicher Informanten (Eltern und Erzieherinnen). Insgesamt erwies sich die deutsche Version des ECBI als ein ökonomisches und sensitives Screening-Verfahren zur Beurteilung von sozialen Verhaltensproblemen bei Vorschulkindern und Erziehungsproblemen der Eltern, das sowohl in pädagogisch-psychologischen als auch klinisch-psychologischen Kontexten eingesetzt werden kann.
Zur Entwicklung deutschsprachiger Testverfahren in der 2. Hälfte des 20. Jahrhunderts
Authors: Eberwein Manfred , Schui Gabriel , Krampen Günter
Published: November 2006

Zusammenfassung. Das Datenbanksegment PSYNDEX Tests, das vom Zentrum für Psychologische Information und Dokumentation (ZPID) an der Universität Trier im Rahmen seines Informationsangebotes für die Psychologie hergestellt wird, verfügt mit aktuell über 5000 Nachweisen über die größte Testdokumentation in den deutschsprachigen Ländern. Die einzelnen Nachweise sind nach verschiedenen Kriterien inhaltlich und formal aufgeschlüsselt und bieten so vielfältige Möglichkeiten für bibliometrische Analysen. Herausgegriffen werden hier die Erscheinungsjahre publizierter psychologischer und pädagogischer Testverfahren seit dem zweiten Weltkrieg, die in einem Verlag vollständig oder in Teilen veröffentlicht wurden. In der Aufgliederung nach Dezennien spiegelt sich aus dem Blickwinkel der psychologischen Diagnostik die Entwicklung der Psychologie wider, so die Blüte psychologisch-pädagogischer Tests in den 70er Jahren des 20. Jahrhunderts, der rasante Aufstieg der klinisch-psychologischen Diagnostik seit diesem Zeitraum und die zunehmende Stagnation projektiver Verfahren seit den 80er Jahren sowie die zunehmend deutlicher werdenden Qualitätsprobleme psychologischer Diagnostik im A&O-Bereich.
Körperbildtherapie bei Essstörungen
Authors: Vocks Silja , Legenbauer Tanja , Troje Nikolaus , Schulte Dietmar
Published: November 2006

Zusammenfassung. Theoretischer Hintergrund: Ein negatives Körperbild kann sich bei Essstörungen in einer Überschätzung der eigenen Körperdimensionen (perzeptive Komponente), negativen Gedanken und Gefühlen hinsichtlich des eigenen Körpers (kognitiv-affektive Komponente) sowie körperbezogenem Vermeidungs- und Kontrollverhalten (behaviorale Komponente) manifestieren. Fragestellung: Es soll überprüft werden, ob diese drei Komponenten eines gestörten Körperbildes durch ein kognitiv-verhaltenstherapeutisches Körperbildtherapieprogramm verbessert werden können. Methode: 24 Essstörungspatientinnen wurden vor und nach einer zehn Sitzungen umfassenden Körperbildtherapie sowie nach einem dreimonatigen Katamnesezeitraum untersucht. Ergebnisse: Während die perzeptive Körperbildkomponente nicht durch die Körperbildtherapie beeinflusst wurde, zeigten sich deutliche Verbesserungen auf der kognitiv-affektiven und behavioralen Ebene. Auch die Essstörungssymptomatik und allgemeine Belastung der Patientinnen reduzierten sich. Diese Effekte blieben über den Katamnesezeitraum stabil. Schlussfolgerungen: Die Befunde liefern Hinweise auf die Wirksamkeit der Körperbildtherapie.
Risikofaktoren des problematischen Glücksspielverhaltens
Authors: Sonntag Dilek
Published: November 2006

Zusammenfassung. Theoretischer Hintergrund: Pathologisches Glücksspielverhalten nach DSM-IV oder ICD-10 wird als Impulskontrollstörung diagnostiziert. In diesem Artikel wird der Begriff auf problematisches Glücksspielverhalten erweitert. In der Literatur dominieren zwei theoretische Entstehungsmodelle: das “Sucht-“ und das “Neurosemodell“. Fragestellung: Was sind die Korrelate und Risikofaktoren für die Entstehung und Aufrechterhaltung problematischen Glücksspielverhaltens, welche Implikationen gibt es für die Modellannahmen und für die Behandlung. Methode: Auf der Basis einer Literaturanalyse wird ein Überblick über die bislang gesicherten Risikofaktoren gegeben. Ergebnisse: Es gibt eine Fülle von Querschnittsstudien und einige Längsschnittstudien, die Hinweise auf das Vorliegen einiger gesicherter Korrelate und Risikofaktoren geben. Schlussfolgerungen: Die Befunde unterstützen bestimmte Modellannahmen und sollten in der Prävention und Therapie von Personen mit problematischem Glücksspielverhalten berücksichtigt werden.
Nitric acid condensation on ice: 1. Non‐HNO3 constituent of NOY condensing cirrus particles on upper tropospheric
Authors: Gamblin B. , Toon O. B. , Tolbert M. A. , Kondo Y. , Takegawa N. , Irie H. , Koike M. , Ballenthin J. O. , Hunton D. E. , Miller T. M. , Viggiano A. A. , Anderson B. E. , Avery M. , Sachse G. W. , Podolske J. R. , Guenther K. , Sorenson C. , Mahoney M. J.
Published: November 2006

Measurements of NOY condensation on cirrus particles during the SOLVE‐I field campaign are analyzed and segregated based on altitude. Significant amounts of NOY were found on the upper tropospheric ice particles; therefore condensation on ice appears to be an important method of NOY removal from the gas phase at the low temperatures of the Scandinavian upper troposphere. For the data set collected on 23 January 2000, NOY condensation on cirrus particles has different properties depending on whether the ice particles are sampled in the upper troposphere, where HNO3 does not dominate NOY, or in the lower stratosphere, where HNO3 does dominate NOY. Nitric acid becomes enriched in the gas phase as NOY condenses on upper tropospheric ice crystals, indicating that a non‐HNO3 component of NOY is condensing on upper tropospheric ice particles much faster and at higher concentrations than HNO3 alone on this day. It is unclear which non‐HNO3 constituent of NOY is condensing on upper tropospheric ice particles, although N2O5 is the most likely species. This condensation of a non‐HNO3 component of NOY is not universal in the upper troposphere but depends on the conditions of the air parcel in which sampling occurred, notably exposure to sunlight.
Retrieval and climatology of the aerosol asymmetry parameter in the NOAA aerosol monitoring network
Authors: Fiebig M. , Ogren J. A.
Published: November 2006

The aerosol monitoring network of the NOAA Earth System Research Laboratory routinely provides data on the aerosol absorption and spectral scattering and backscattering coefficients. An algorithm is introduced that retrieves from the primary measurements the aerosol asymmetry parameter, the optical property needed in addition to those mentioned above to completely characterize aerosol with respect to its direct radiative effect on climate. The algorithm is tested on synthetic data and shown to retrieve the spectral aerosol asymmetry parameter for aerodynamic particle diameters Dp,aer < 1.0 μm with ∼0.8% systematic uncertainty and ∼1.1% systematic uncertainty for Dp,aer < 10.0 μm. The algorithm is applied to data from six ESRL stations representing aerosol in the dried state of continental, marine, arctic, and free tropospheric origin. The retrieved asymmetry parameters show a significant dependence on wavelength. Both wavelength dependence and absolute value of the asymmetry parameter depend on location or air mass type. The median values range from 0.57 for free tropospheric aerosol to 0.65 for marine aerosol at 550 nm wavelength and Dp,aer < 10.0 μm. It is shown that the accuracy of the asymmetry parameters retrieved with the algorithm is significantly larger than that of asymmetry parameters derived from backscatter fractions assuming a Henyey‐Greenstein phase function.
Comparison of International Panel on Climate Change Fourth Assessment Report climate model simulations of surface albedo with satellite products over northern latitudes
Authors: Wang Shusen , Trishchenko Alexander P. , Khlopenkov Konstantin V. , Davidson Andrew
Published: November 2006

The surface albedos simulated by seventeen climate models over the northern latitudes of the Western Hemisphere were compared with satellite‐derived albedo products provided by the International Satellite Cloud Climatology Project (ISCCP). Model simulations were conducted in support of the International Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). Results show the following: (1) Annual albedo of the region averaged for all models is fairly close to that provided by the ISCCP (0.351 versus 0.334). The difference between model average and ISCCP albedos is well below the standard deviation in albedo among models. (2) Most models simulated seasonal variations in regional albedo reasonably well. In summer, the models systematically overestimated albedo relative to the ISCCP data by as much as 0.05. In winter, large differences were detected among the climate models. (3) The spatial correlations among models, and between models and ISCCP, depend on geographic location, season and surface type. In general, the spatial correlation coefficients between individual models and the ISCCP data were highest for the land surface in midsummer and for the ocean surface in spring. Model bias was smaller for the ocean surface than for the land surface, and smaller in summer than in winter. (4) Unlike the modeling results, the satellite data showed large interannual variations in albedo and a systematic decreasing trend over the 16 year period of 1984–1999. Depending on season, the standard deviation of albedo interannual variation ranged from 0.036 to 0.074, and the linear regression slope of the decreasing trend ranged from −0.02 to −0.05 per decade according to ISCCP results. The large interannual variation and decreasing trend are not reflected in model simulations. Additional efforts are still required to improve surface albedo simulations in GCMs and its mapping from satellite.
Recent unrest at Canary Islands' Teide Volcano?
Authors: Carracedo Juan Carlos , Troll Valentin R. , Pérez Francisco J. , Badiola Eduardo Rodríguez , Machín Alex Hansen , Paris Raphael , Guillou Hervé , Scaillet Stéphane
Published: November 2006

When a volcano that has been dormant for many centuries begins to show possible signs of reawakening, scientists and civil authorities rightly should be concerned about the possibility that the volcanic unrest might culminate in renewed eruptive activity. Such was the situation for Teide volcano, located on Tenerife in the Canary Islands, when a mild seismic swarm during April–July 2004 garnered much attention and caused public concern. However, that attention completely ignored the fact that the seismic recordings of the swarm were due to a much improved monitoring system rather than due to an actual event of alarming magnitude or extent.

It is important in any effective program of volcano‐risk mitigation that the response to an apparent change in the status of a volcano should include the immediate implementation or augmentation of monitoring studies to better anticipate possible outcomes of the volcanic unrest. Equally important, emergency‐management officials, using available scientific information and judgment, must take appropriate precautionary measures—including information of the populations at potential risk—while not creating unjust anxiety or alarm.
Refocusing NASA planetary science funding
Authors: Zielinski Sarah
Published: November 2006

NASA should invest more money in data analysis for its planetary science missions, even if it means delaying or canceling a future mission, members of the science committee of the NASA Advisory Council (NAC) uggested at a 12 October meeting.

Science committee member Mark Robinson, director of the Center for Planetary Sciences at Northwestern University in Chicago, Ill., said that large amounts of data from NASA planetary science missions are accumulating, and the funds for data analysis often are inadequate to properly analyze all of it. For example, there is a large amount of currently unanalyzed Mars data that could be used in planning for the Mars Science Laboratory (expected to launch in 2009), and particularly for site selection. This includes data from the recently arrived Mars Reconnaissance Orbiter, which is likely to send more data to Earth in its first year than has been collected by all previous Mars missions combined.
New rings found around Saturn
Authors: Zielinki Sarah
Published: November 2006

Images of Saturn taken by the Cassini spacecraft's wide‐angle camera in September, with the Sun directly behind the planet, have revealed the existence of two new rings around the planet and have confirmed the presence of two other suspected rings, NASA announced on 11 October. Two of the rings are associated with, and share the orbits of, one or more Saturn moonlets, and scientists expect to find a moonlet in at least one of the other two rings.
Climate change to bring more heat, less rain to U.S. northeast
Authors: Zielinski Sarah
Published: November 2006

If greenhouse gas emissions are not curtailed, the Northeast United States will experience higher average temperatures, less snow, and more drought, according to a 4 October synthesis report from the nonprofit Union of Concerned Scientists and a team of independent scientists from across the country. The scientists reviewed current research and models, and they found that by the end of the century, temperatures in the region would increase by 3.6–6.9°C, the number of days with snow on the ground would be reduced by 50%, and major cities could experience 30 to 60 summer days (compared with 10 to 15 days, historically) with temperatures exceeding 32.2°C. If emissions are reduced, less dramatic change could be expected, the report indicates. The report, “Climate Changes in the U.S. Northeast,” is the first in a series that will assess the impact of climate change in the region on forests and agriculture, coastal and marine resources, and human health.
Collaboration between shipboard oceanic and atmospheric programs
Authors: Smith Shawn R.
Published: November 2006

There are a few programs dedicated to providing high‐quality, automated surface oceanographic and meteorological observations from ships to the research and operational community. These observations typically include vessel position and motion, winds, air and sea temperature, atmospheric pressure and humidity, precipitation, radiation at the Earth's surface, sea surface salinity conductivity, fluorescence and other ocean measurements. The observations, which are a component of a global ocean observing system, provide essential benchmark values that can aide in understanding the exchange of heat, moisture, carbon, and other quantities that cross the ocean‐atmosphere interface.

The U.S. National Oceanic and Atmospheric Administration (NOAA) Office of Climate Observation sponsored a recent workshop to initiate collaboration between the Global Ocean Surface Underway Data (GOSUD) pilot project (http://www.gosud.org/), the Shipboard Automated Meteorological and Oceanographic System (SAMOS) initiative (http://samos.coaps.fsu.edu/), and other international programs that provide these essential observations. The goals of the workshop were to improve international collaboration between shipboard observation programs and to stimulate interest in applying these observations to applications such as satellite and model product evaluation, air‐sea flux analyses, and ocean process studies.
Young scientists focus on the dynamics of the lithosphere
Authors: Montesi Laurent G. J. , Di Toro Giulio , Simons Frederik J. , Akber‐Knutson Sofia , Becker Thorsten W. , Billen Magali , Deschamps Anne , Kellogg James B.
Published: November 2006

Young researchers face a wide choice of scientific approaches and directions that may shape their careers. The Earth sciences, in particular, offer a broad range of topics to study and techniques to use that exceeds what any current scientist was exposed to at the schools they attended. At early stages of their careers, researchers need to gain confidence in their expertise, and they often can benefit by expanding their scientific horizons and forging new collaborations
Observational relationships between aerosol and Asian monsoon rainfall, and circulation
Authors: Lau K.‐M. , Kim K.‐M.
Published: November 2006

Preliminary observational evidences are presented showing that the Indian subcontinent and surrounding regions are subject to heavy loading of absorbing aerosols, i.e., dust and black carbon, which possess spatial and temporal variability that are closely linked to those of the Asian monsoon water cycle. Consistent with the Elevated Heat Pump hypothesis, we find that increased loading of absorbing aerosols over the Indo‐Gangetic Plain in the pre‐monsoon season is associated with a) increased heating of the upper troposphere, with the formation of a warm‐core upper level anticyclone over the Tibetan Plateau in April–May, b) an advance of the monsoon rainy season in northern India in May, and c) subsequent increased rainfall over the Indian subcontinent, and decreased rainfall over East Asia in June–July.
A clear‐sky radiance archive from Meteosat “water vapor” observations
Authors: Brogniez Hélène , Roca Rémy , Picon Laurence
Published: November 2006

A long‐term archive of clear‐sky Meteosat “water vapor” observations, covering the July 1983 to February 1997 period with a 3 hourly time step and a spatial resolution of 0.625°, is presented. Cloud clearing is performed using a scene selection procedure based on the International Satellite Cloud Climatology Project DX product. In this procedure low cloud scenes are kept because of the negligible contribution of the low atmospheric layer in this spectral band. Cloud contamination is shown to have little influence on the clear‐sky radiance (CSR) field and is mainly confined to the continental Intertropical Convergence Zone with values less than 0.5 K. This scene selection yields to a significantly enhanced sampling with respect to pure clear‐sky in the subtropical high regions. Homogenization of the 14 year database is performed in accordance with existing technique. A comparison to the operational radiosondes archive indicates a small bias of 0.3 K that is stable throughout the period. A first analysis of the CSR variability reveals that the intraseasonal variance over the subtropical dry regions has a strong seasonal cycle in the Northern Hemisphere that is not observed in the Southern Hemisphere. Such a data set completes the ones currently available to document the water vapor variability of the troposphere from climatic down to regional and daily scales.
Intercomparisons of trace gases profiles from the Odin/SMR and Aura/MLS limb sounders
Authors: Barret B. , Ricaud P. , Santee M. L. , Attié J.‐L. , Urban J. , Le Flochmoën E. , Berthet G. , Murtagh D. , Eriksson P. , Jones A. , de La Noë J. , Dupuy E. , Froidevaux L. , Livesey N. J. , Waters J. W. , Filipiak M. J.
Published: November 2006

This paper presents the intercomparison of O3, HNO3, ClO, N2O and CO profiles measured by the two spaceborne microwave instruments MLS (Microwave Limb Sounder) and SMR (Submillimetre Radiometer) on board the Aura and Odin satellites, respectively. We compared version 1.5 level 2 data from MLS with level 2 data produced by the French data processor version 222 and 225 and by the Swedish data processor version 2.0 for several days in September 2004 and in March 2005. For the five gases studied, an overall good agreement is found between both instruments. Most of the observed discrepancies between SMR and MLS are consistent with results from other intercomparison studies involving MLS or SMR. O3 profiles retrieved from the SMR 501.8 GHz band are noisier than MLS profiles but mean biases between both instruments do not exceed 10%. SMR HNO3 profiles are biased low relative to MLS's by ∼30% above the profile peak. In the lower stratosphere, MLS ClO profiles are biased low by up to 0.3 ppbv relative to coincident SMR profiles, except in the Southern Hemisphere polar vortex in the presence of chlorine activation. N2O profiles from both instruments are in very good agreement with mean biases not exceeding 15%. Finally, the intercomparison between SMR and MLS CO profiles has shown a good agreement from the middle stratosphere to the middle mesosphere in spite of strong oscillations in the MLS profiles. In the upper mesosphere, MLS CO concentrations are biased high relative to SMR while negative values in the MLS retrievals are responsible for a negative bias in the tropics around 30 hPa.
Study of thermal transport in nanoparticle suspensions using forced Rayleigh scattering
Authors: Venerus David C. , Kabadi Madhu S. , Lee Sunmook , Perez-Luna Victor
Published: November 2006

Thermal diffusivity measurements on two nanofluids and their base fluids were made using an optical technique called forced Rayleigh scattering. The nanofluids studied were a citrate-stabilized Au nanoparticle suspension in water and an Al2O3 nanoparticle suspension in a petroleum oil. Thermal diffusivity measurements on the nanofluids and base fluids were made at temperatures in the range of 25–75°C. From these data, it was possible to estimate the thermal conductivity enhancement in the nanofluids as a function of temperature. In contrast to previous reports on similar systems, our experiments are consistent with thermal conductivity enhancement predictions from effective medium theory. In particular, we find that the level of thermal conductivity enhancement is independent of temperature.
Metal-induced nanocrystalline structures in Ni-containing amorphous silicon thin films
Authors: Ferri F. A. , Zanatta A. R. , Chambouleyron I.
Published: November 2006

The mechanisms of silicon nanocrystal structure formation in amorphous Si films have been studied for a relative Ni impurity content varying between 0.1 and 10at.%, i.e., from a Ni doping range to the Si–Ni alloy phase. The films, deposited by the cosputtering technique at 200°C, were submitted to isochronal (15min) annealing cycles up to 800°C. Four different substrates were used to deposit the studied films: crystalline (c-) quartz, c-Si, c-Ge, and glass. Both the two orders of magnitude impurity concentration range variation and the very short annealing times were selected on purpose to investigate the first steps of the mechanism leading to the appearance of crystal seeds. The conclusions of this work are the following: (a) Ni impurity induces the low-temperature crystallization of amorphous silicon; (b) the NiSi2 silicide phase mediates, at the surface or in the bulk of the film, the crystallization process; and (c) the onset of crystallization and the crystalline fraction of the samples at each temperature depend not only on the Ni impurity concentration, but also on the nature of the substrate.
Control of the thin film properties of Cu(In,Ga)Se2 using water vapor introduction during growth
Authors: Ishizuka Shogo , Shibata Hajime , Yamada Akimasa , Fons Paul , Sakurai Keiichiro , Matsubara Koji , Niki Shigeru , Yonemura Minoru , Nakanishi Hisayuki
Published: November 2006

The effects of water vapor introduction during growth on Cu(In,Ga)Se2 (CIGSe) thin film properties, specifically the electrical and photoluminescence (PL) properties have been studied. Increases in the hole carrier density and conductivity with water vapor introduction were observed for all [Ga]∕[In+Ga] composition ratios. The PL spectra observed from CuGaSe2 (CGSe) showed an annihilation of deep donor-acceptor pair emissions related to Se vacancies with water vapor introduction. In addition, the Na content in the CIGSe layers as well as the O content was found to increase. These results suggest that the mechanism behind the variation observed in the electrical and PL properties and consequent cell improvement is largely attributable to a decrease in the Se-vacancies-induced donor defect density and an enhancement of Na effects.
Effect of dislocations on electrical and electron transport properties of InN thin films. II. Density and mobility of the carriers
Authors: Lebedev V. , Cimalla V. , Baumann T. , Ambacher O. , Morales F. M. , Lozano J. G. , González. D.
Published: November 2006

The influence of dislocations on electron transport properties of undoped InN thin films grown by molecular-beam epitaxy on AlN(0001) pseudosubstrates is reported. The microstructure and the electron transport in InN(0001) films of varying thickness were analyzed by transmission electron microscopy and variable temperature Hall-effect measurements. It was found that crystal defects have strong effects on the electron concentration and mobility of the carriers in the films. In particular, the combined analysis of microscopy and Hall data showed a direct dependence between free carrier and dislocation densities in InN. It was demonstrated that threading dislocations are active suppliers of the electrons and an exponential decay of their density with the thickness implies the corresponding decay in the carrier density. The analysis of the electron transport yields also a temperature-independent carrier concentration, which indicates degenerate donor levels in the narrow band-gap InN material. The relative insensitivity of the mobility with respect to the temperature suggests that a temperature-independent dislocation strain field scattering dominates over ionized impurity∕defect and phonon scattering causing the increase of the mobility with rising layer thickness due to the reducing dislocation density. Room temperature mobilities in excess of 1500cm2V−1s−1 were obtained for ∼800nm thick InN layers with the dislocation densities of ∼3×109cm−2.
Paraxial theory of supercritical wave phase conjugation in a realistic magnetoacoustic conjugator
Authors: Merlen Alain , Zhang Qi
Published: November 2006

A recent theory of supercritical phase conjugation gives explicitly the paraxial analytical solution for a completely active conjugator in contact with arbitrary media. This letter extends the theory to the more realistic case of a limited active zone inside a conjugator in contact with arbitrary media. This configuration describes more accurately the experimental situations in ultrasonic parametric phase conjugation. The main practical result is the possibility of adjustable artificial impedance.
Liquid nitrogen cooled integrated power electronics module with high current carrying capability and lower on resistance
Authors: Ye Hua , Lee Changwoo , Simon Randy W. , Haldar Pradeep , Hennessy Michael J. , Mueller Eduard K.
Published: November 2006

This letter presents the development of high-performance integrated cryogenic power modules, where both driver components and power metal-oxide semiconductor field-effect transistors are integrated in a single package, to be used in a 50kW prototype cryogenic inverter operating at liquid nitrogen temperature. The authors have demonstrated a compact high-voltage, cryogenic integrated power module that exhibited more than 14 times improvement in on-resistance and continuous current carrying capability exceeding 40A. The modules are designed to operate at liquid nitrogen temperature with extreme thermal cycling. The power electronic modules are necessary components that provide control and switching for second generation, yttrium barium copper oxide-based high temperature superconductor devices including cables, motors, and generators.
Spin-dependent tunneling characteristics of fully epitaxial magnetic tunneling junctions with a full-Heusler alloy Co2MnSi thin film and a MgO tunnel barrier
Authors: Ishikawa T. , Marukame T. , Kijima H. , Matsuda K.-I. , Uemura T. , Arita M. , Yamamoto M.
Published: November 2006

Fully epitaxial, exchange-biased magnetic tunnel junctions (MTJs) were fabricated with a Co-based full-Heusler alloy Co2MnSi (CMS) thin film as a lower electrode, a MgO tunnel barrier, and a Co50Fe50 upper electrode. The microfabricated CMS∕MgO∕Co50Fe50 MTJs exhibited relatively high tunnel magnetoresistance ratios of 90% at room temperature and 192% at 4.2K. The bias voltage dependence of differential conductance (dI∕dV) for the parallel and antiparallel magnetization configurations suggested the existence of a basic energy gap structure for the minority-spin band of the CMS electrode with an energy difference of about 0.4eV between the bottom of the vacant minority-spin conduction band and the Fermi level.
Domain nucleation and hysteresis loop shape in piezoresponse force spectroscopy
Authors: Morozovska Anna N. , Eliseev Eugene A. , Kalinin Sergei V.
Published: November 2006

Electromechanical hysteresis loop measurements in piezoresponse force microscopy (PFM) [piezoresponse force spectroscopy (PFS)] have emerged as a powerful technique for probing ferroelectric switching behavior on the nanoscale. Interpretation of PFS data requires the relationship between the domain parameters and PFM signal to be established. Here, the authors analyze the switching process using modified point charge model. The charge parameters are selected to reproduce tip-induced surface potential and tip radius of curvature. The relationship between geometric parameters of semiellipsoidal domain and PFM signal is derived using linear Green’s function theory. The role of domain nucleation on hysteresis loop is established.
Efficient single-photon counting at 1.55μm by intracavity frequency upconversion in a unidirectional ring laser
Authors: Pan Haifeng , Dong Huafang , Zeng Heping , Lu Wei
Published: November 2006

A single-photon signal at 1.55μm was converted to its visible replica by sum-frequency mixing with a strong intracavity pump of a unidirectional ring laser at 1.06μm in a periodically poled lithium niobate (PPLN) crystal. In the ring laser configuration, standing-wave photorefractive effects in the PPLN crystal could be suppressed and consequently, the spectral bandwidth of the intracavity pump could be controlled for excellent quasi-phase-matching. A conversion efficiency of 96% was demonstrated, and the corresponding background counts were less than 6.0×105s−1. The single-photon upconversion was used for efficient single-photon counting at 1.55μm with long-term stability.
Large scale directed assembly of nanoparticles using nanotrench templates
Authors: Xiong Xugang , Makaram Prashanth , Busnaina Ahmed , Bakhtari Kaveh , Somu Sivasubramanian , McGruer Nicol , Park Jingoo
Published: November 2006

The authors describe a general high throughput directed assembly technique to address some of the challenges to enable high rate∕high volume nanomanufacturing. The directed assembly of colloidal particles using an applied electric field shows the ability of precise control of nanoparticles by controlling assembly voltage, time, and geometric design of templates. The results show that single nanoparticle lines as small as 10nm wide and 100000nm long over a 2.25cm2 area as well as other nanoparticle structures can be fabricated using electrophoresis. This approach offers a simple, robust, and fast means of directed assembly of nanoelements for many applications.
On the use of Monte Carlo modeling in the mathematical analysis of scanning electron microscopy–electron beam induced current data
Authors: Parish C. M. , Russell P. E.
Published: November 2006

Electron beam induced current (EBIC) is often used to evaluate minority carrier properties in semiconductors. Various mathematical models have been proposed; the most advanced is that of Bonard and Ganière [J. Appl. Phys. 79, 6987 (1996)]. However, in order to apply this model to EBIC experiments, the lateral and depth distributions of the electron-hole-pair generation in the sample must be known. This letter presents a straightforward method based on Monte Carlo simulation of the electron beam interaction with the sample to evaluate these distribution parameters. A quantitative experimental example from a GaN-based light emitting diode is presented to test the proposed method.
Spectroscopy of the nonlinear refractive index of colloidal PbSe nanocrystals
Authors: Moreels I. , Hens Z. , Kockaert P. , Loicq J. , Van Thourhout D.
Published: November 2006

A spectroscopic study of the optical nonlinearity of PbSe colloidal solutions was performed with the Z-scan technique at wavelength intervals of 1200–1350 and 1540–1750nm. While nonlinear absorption remains below the detection threshold, the third order nonlinear refractive index n2 shows clear resonances, somewhat blueshifted relative to the exciton transitions in the absorbance spectrum. The occurrence of thermal effects is ruled out by time-resolved measurements. At 1.55μm, measured (resonant) n2 values exceed typical bulk semiconductor values by two orders of magnitude. At high optical intensity, the refractive index change saturates, indicating that statefilling lies at the origin of the observed effect.