bluuebunny/crossref_metadata_2025 huggingface dataset:
Aufmerksamkeitsdefizit-/ Hyperaktivitätsstörungen bei Drei- bis Sechsjährigen in der ärztlichen Praxis - eine bundesweite Befragung
Authors: Breuer Dieter , Döpfner Manfred
Published: September 2006

Zusammenfassung: Fragestellung: Ziel der Arbeit ist die Ermittlung der Prävalenzen von Symptomen und Diagnosen einer Aufmerksamkeitsdefizit- /Hyperaktivitätsstörung (ADHS) bei Kindern im Vorschulalter, die Erfassung der Funktionseinschränkungen und komorbider Symptome im Eltern- und Erzieherurteil. Methodik: Bundesweit nahmen 708 Kinder aus 103 pädiatrischen oder kinder- und jugendpsychiatrischen Praxen teil. Verwendet wurden Fremdbeurteilungsbögen für Hyperkinetische Störungen im Vorschulalter (FBB-ADHS-V) im Eltern- und Erzieherurteil, sowie ärztliche Beurteilungen von n = 521 Kindern aus U8/U9 Vorsorgeuntersuchungen (U8/U9), oder vom Arzt als ADHS-auffällig eingeschätzte Kinder n = 187 (AUF) unter Ausschluss einer U8/U9-Vorsorgeuntersuchung. Ergebnisse: In U8/U9 erfüllen im Elternurteil 11,3% der Kinder die Diagnosekriterien für eine der drei ADHS-Diagnosen nach DSM-IV (ICD-10: 3,8%), im Erzieherurteil sind es nur 6,6% (ICD-10: 1,5). Bei Beurteilerübereinstimmung erfüllen 4,2 % aller Kinder aus U8/U9 diese Diagnosekriterien (ICD-10: 1,2%). In AUF zeigen sich wesentlich höhere Diagnose-Prävalenzen und komorbide Auffälligkeiten. Der Behandlungs- und Beratungsbedarf der Eltern liegt deutlich über der Rate der Eltern/Kinder, die eine Beratung/Behandlung erhalten. Schlussfolgerungen: Prävalenzraten internationaler Autoren können bestätigt werden. Vor dem Hintergrund hoher Komorbiditäts- und niedriger Behandlungsraten zeigt die Studie trotz methodischer Einschränkungen, wie fehlender Repräsentativität und möglicher Präselektion, die Relevanz von Präventionsmaßnahmen und Interventionsprogrammen bei Kindern im Vorschulalter.
Behandlungsbewertungen von Jugendlichen im Verlauf einer stationär-psychiatrischen Behandlung
Authors: Keller Ferdinand , Peter Susanne , Fegert Jörg M. , Naumann Alexander , Goldbeck Lutz
Published: September 2006

Zusammenfassung: Fragestellung: Einschätzungen zur Prozessqualität psychiatrisch/psychotherapeutischer Behandlung erfolgen meist rückblickend bei Entlassung, weshalb bisher wenig bekannt ist über Veränderungen in der Zufriedenheit mit den Therapien und bei verwandten Aspekten wie Partizipation und Motivation. Es wird untersucht, ob computergestützte Befragungen im stationären Verlauf machbar sind, die Fragen differenzieren, und ob sich Gruppenunterschiede im Verlauf und in der Variabilität ergeben. Methodik: 88 Jugendliche (48 Mädchen, 44 Jungen) im Alter von 13 bis 18 Jahren, die sich auf jugendpsychiatrischen Abteilungen zweier Kliniken in Behandlung befanden, wurden zwei Mal wöchentlich mit 16 Items zu den genannten Themen befragt; insgesamt stehen 1003 Befragungen zur Verfügung, der Median der Befragungen pro Person liegt bei 8. Ergebnisse: Psychometrische Analysen sprechen für eine gute Differenziertheit der Fragen. Auswertungen mit einem Wachstumskurvenmodell, das wegen der unterschiedlich langen Zeitreihen und vereinzelt auftretenden fehlenden Werten bevorzugt wurde, zeigen, dass in den personenspezifischen Verlaufskurven die Niveaus sehr unterschiedlich sind. In der globalen Zufriedenheit bleiben sie im Verlauf der Behandlung relativ stabil. Im Bereich von Mitbestimmung ergeben sich unterschiedliche Trends und auch ein Unterschied zwischen den beiden beteiligten Kliniken, der auf die unterschiedliche Teamerfahrung zurückzuführen sein dürfte, während Alter, Geschlecht und Diagnose nur eine geringe Rolle spielen. Schlussfolgerungen: Eine begleitende computergestützte Datenerhebung unter stationären Behandlungsbedingungen zur Evaluation der Prozessqualität bei Jugendlichen hat sich als praktikabel erwiesen und ergänzt die ergebnisorientierte Forschung um eine prozessorientierte Perspektive.
Bibliotherapie als Behandlungs- möglichkeit bei Kindern mit externalen Verhaltensstörungen
Authors: Kierfeld Frauke , Döpfner Manfred
Published: September 2006

Zusammenfassung: Fragestellung: Expansives Problemverhalten zählt zu den häufigsten und stabilsten Verhaltensauffälligkeiten im Kindes- und Jugendalter. Praktikable Alternativen zu teuren und nicht in ausreichendem Maße verfügbaren Behandlungen werden zunehmend notwendig. Ziel der vorliegenden Pilotstudie war es, Bibliotherapie in Form eines manualgestützten Selbsthilfeprogramms unter minimalen Kontaktbedingungen bei Eltern von Kindern mit expansivem Problemverhalten zu erproben. Methodik: Insgesamt wurden 21 Kinder im Alter von 6 bis 15 Jahren mit der Diagnose einer Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) und/oder einer Störung mit oppositionellem Trotzverhalten aus einer klinischen Inanspruchnahmepopulation rekrutiert. Die Bibliotherapie erstreckte sich über einen Zeitraum von 10 Wochen und beinhaltete neben einem Erstgespräch, einer Eingangs- und Abschlussdiagnostik, die schrittweise Durcharbeitung des Elternbuches «Wackelpeter und Trotzkopf». Begleitend fanden mit den Eltern wöchentlich kurze Telefonkontakte (ca. 20 Min.) statt. Ergebnisse: Das expansive Verhalten der Kinder nahm signifikant ab. Das Erziehungsverhalten der Eltern konnte gestärkt werden. Die Zufriedenheit mit dem Programm war hoch. Das Angebot einer anschließenden intensiven Therapie nahmen weniger als 20% in Anspruch. Schlussfolgerungen: Die Bibliotherapie könnte eine praktikable und effektive Behandlungsalternative für Kinder mit Aufmerksamkeitsdefizit-/Hyperaktivitätsstörungen und/oder oppositionellen Verhaltensstörungen sein - zumindest für Familien mit entsprechenden Ressourcen, die für die Durchführung von Bibliotherapie notwendig sind. Die Ergebnisse sind in Replikationen auch mittels randomisierter Kontrollgruppenstudien zu prüfen.
Seltene Formen der Invagination im Kindesalter
Authors: Tschirch  , Huisman
Published: September 2006

Invaginationen kommen häufig bei Kindern im Alter unter 2 Jahren vor. Diese sind meist idiopathisch, während sekundäre Invaginationen auf Grund von fokalen Pathologien selten auftreten. Wir berichten über zwei ungewöhnliche Fälle von ileokolischer Invagination: bei einem Kind wurde ein mobiles Zökum gesehen, bei einem zweiten Kind liess sich eine Duplikationszyste der Ileozökalklappe nachweisen.
Patientin aus Kamerun mit rezidivierenden, transienten, juckenden Schwellungen an Armen und Beinen
Authors: Gessler Stähelin  , Nüesch
Published: September 2006

Wir berichten über eine 36-jährige, aus Kamerun stammende Patientin mit rezidivierenden, transienten Schwellungen an den Extremitäten verbunden mit starkem Juckreiz. Zudem Augensymtome mit zeitweiligem Gefühl, «als ob ein Wurm ihr Auge durchquere». Die weitere Diagnostik ergab ein Eosinophilie und die Filarienserologie war positiv, sodass die Verdachtsdiagnose einer Loiasis mit rezidivierenden Kalabarschwellungen bestätigt werden konnte. Der Mikrofilariennachweis im Blut und Urin gelang nicht, was wir auf die geringe Mikrofilariendichte zurückführten. Unter einer Einmaldosis Ivermectin (43 × 3 mg) war die Patientin in der Folge beschwerdefrei. Die Loiasis kommt vorwiegend im tropischen Regenwald Zentral- und Westafrikas vor und gehört zu den Filariosen. Die Übertragung erfolgt durch die tagaktive Chrysopsfliege. Die Krankheit verursacht meist keine erntshaften Schäden, führt jedoch in endemischen Gebieten zu chronischen Beschwerden. Eine medikamentöse Therapie ist mit Diethylcarbamazine, Ivermectin oder auch Albendazol möglich. Prävention erfolgt durch schützende helle Kleidung, Anwendung von Insektensprays und allenfalls präventive Therapie mit Diethylcarbamazine oder Ivermectin.
Konstruktion visuell-räumlicher Repräsentationen beim Hör- und Leseverstehen
Authors: Kürschner Christian , Seufert Tina , Hauck Georg , Schnotz Wolfgang , Eid Michael
Published: September 2006

Zusammenfassung. In Lehr- und Lernumgebungen können Informationen sowohl mit Hilfe von Lesetext als auch mit Hilfe von Hörtext vermittelt werden. Nach wie vor ist jedoch unklar, inwieweit sich Hör- und Leseverstehensprozesse voneinander unterscheiden. In der vorliegenden Arbeit wurde die Verarbeitung von visuell-räumlicher Information aus Hör- und Lesetexten anhand von zwei Studien untersucht. In Studie 1 wurde insbesondere auf die Rolle des Arbeitsgedächtnisses eingegangen. Es konnte gezeigt werden, dass das Hören dem Lesen beim Erinnern von kurzen und semantisch wenig komplexen Textabschnitten mit visuell-räumlichen Inhalten überlegen ist. Es wird angenommen, dass die kognitive Verarbeitung visuell-räumlicher Inhalte und der Prozess des Lesens auf Grund gemeinsam genutzter Ressourcen im Arbeitsgedächtnis interferieren. In Studie 2 wurden Hör- und Leseverstehensleistungen unter ökologisch valideren Lernbedingungen mit längerem und komplexerem Lernmaterial miteinander verglichen. Die Ergebnisse zeigen, dass der zuvor berichtete Vorteil der Hör- gegenüber der Lesebedingung bei der Konstruktion und Aufrechterhaltung visuell-räumlicher Repräsentationen nicht mehr auftritt. Insgesamt konnte somit gezeigt werden, dass sich Hör- und Leseverstehensprozesse bei der Verarbeitung von visuell-räumlichen Inhalten unterscheiden, es jedoch von den Verarbeitungsbedingungen abhängt, ob diese Unterschiede sich auf die konstruierte mentale Repräsentationen des Sachverhaltes auswirken.
Psychophysiologisches Monitoring während einer Altorientalischen Musiktherapie - Untersuchung der Beziehung zwischen Therapeut und Patient
Authors: Tucek Gerhard , Fritz Florentina Maria , Ferstl Elisabeth
Published: September 2006

Zusammenfassung. Die rezeptive Altorientalische Musiktherapie setzt ihren Schwerpunkt darauf, bestimmten körperlichen bzw. emotionalen Zuständen einen ausgleichenden musikalischen Impuls entgegenzusetzen und dem Patienten in angenehmer Atmosphäre eine Abfolge von komponierten bzw. improvisierten Melodien zu Gehör zu bringen. Im Rahmen einer ersten Pilotstudie wurden mittels psychophysiologischem Monitoring die Parameter Hautwiderstand, Hautpotential und Elektromyogramm während Altorientalischer Musiktherapiesitzungen mittels rezeptiver Musikapplikationen erfasst und mittels Zeitreihenanalyse verarbeitet, um objektive Rückschlüsse auf die Befindlichkeit des Patienten zu gewinnen. Im vorliegenden Beitrag werden unterschiedliche Therapieverläufe mit verschiedenen Ausgangssituationen der Patienten anhand zweier Fallbeispiele gezeigt. In der Ergebnisdarstellung wird der Einfluss der Vertrautheit und zwischenmenschlichen Komponente zwischen Patient und Therapeut diskutiert sowie auf eine generelle entspannende und harmonisierende Wirkung dieser Therapieform hingewiesen.
Psycho-physiologische Forschungsbeiträge zur Musikwirkung
Authors: Vanecek Erich , Biegl Thomas , Gerngroß Johanna
Published: September 2006

Zusammenfassung. An der Fakultät für Psychologie der Universität Wien wurden unter der Leitung von Erich Vanecek Musikwirkungsforschungen mit modernen psycho-physiologischen Methoden durchgeführt. Thomas Biegl wies Veränderungen einiger physiologischer Parameter, die Wohlbefinden signalisieren (u.a. Serotonin, Dopamin, Beta-Endorphin, Adrenalin) während eines Gesang-Live-Auftrittes nach. Anneliesl Gabriel et al. untersuchten Änderungen der Befindlichkeit und der sIgA-Konzentration beim Anhören von erwünschter und unerwünschter Musik sowie nach halbstündigem Klavierspielen. Johanna Gerngroß untersuchte Beziehungen zwischen dem Flow-Erlebnis und subjektiven und physiologischen Reaktionen (Hautleitwert, Pulsfrequenz und Pulsvolumenamplitude) bei der Rezeption von Tanz. Die Studie von Kristina Hutterer zeigte deutliche positive Einflüsse des Singens und begleitender Atem- und Stimmübungen auf die Befindlichkeit von Senioren. Michaela Fürst beobachtete in der Arbeit “Musik als Lebenshilfe?“ förderliche Einflüsse der musikalischen Betätigung auf Persönlichkeit, Selbstkonzept und Lebenszufriedenheit.
Chemical reaction pathways affecting stratospheric and mesospheric ozone
Authors: Grenfell J. Lee , Lehmann Ralph , Mieth Peter , Langematz Ulrike , Steil Benedikt
Published: September 2006

Catalytic cycles and other chemical pathways affecting ozone are normally estimated empirically in atmospheric models. In this work we have automatically quantified such processes by applying a newly developed analysis package called the “Pathway Analysis Program” (PAP). It used modeled chemical rates and concentrations as input. These were supplied by the “Module Efficiently Calculating the Chemistry of the Atmosphere” MECCA box model, itself initialized by the Free University of Berlin Climate Middle Atmosphere Model with Chemistry. We analyzed equatorial, midlatitude and high‐latitude locations over 24‐hour periods during spring in both hemispheres. We present results for locations in the lower stratosphere, upper stratosphere and midmesosphere. Oxygen photolysis dominated (>99%) in situ ozone production in the equatorial lower stratosphere, in the upper stratosphere and in the mesosphere. In the lower stratosphere midlatitudes the “ozone smog cycle” (already established in the troposphere) rivaled oxygen photolysis as an in situ ozone source in both hemispheres. However, absolute ozone production rates in midlatitudes were rather slow compared with at the equator, typically 16–50 ppt ozone/day. In the equatorial lower stratosphere, five catalytic sinks were important (each contributing at least 5% to chemical ozone loss): a HOx cycle, a HOBr cycle and its HOCl analog, a water‐HOx cycle and a mixed chlorine‐bromine cycle. Important in midlatitudes were the HOx cycle, a NOx cycle, the HOBr cycle and the mixed chlorine‐bromine cycle. In lower‐stratosphere high latitudes, the chlorine dimer cycle and the mixed chlorine‐bromine cycle dominated in both hemispheres. A variant on the latter, involving BrCl formation, also featured. In the upper stratosphere high latitudes (where strong negative ozone trends are observed), a nitrogen cycle, a chlorine cycle, and a mixed chlorine‐nitrogen cycle were found. In the mesosphere, three closely related HOx cycles dominated ozone loss.
Observations of intermediate‐scale diurnal waves in the equatorial mesosphere and lower thermosphere
Authors: Lieberman R. S. , Riggin D. M. , Garcia R. R. , Wu Qian , Remsberg E. E.
Published: September 2006

The purpose of this study is to seek observational evidence for diurnal, vertically propagating inertia‐gravity waves (IGWs) in the mesosphere and lower thermosphere (MLT). Numerical modeling studies indicate that vertically propagating IGWs excited by tropical heating provide a significant source of momentum for the semiannual oscillation (SAO) in the equatorial zonal mean winds. The power spectrum of these waves has a strong diurnal component. We analyze global patterns of ascending and descending node differences in MLT satellite temperatures, which are assumed in this study to be proxies for waves of diurnal period. Juxtaposed upon the planetary‐scale features are localized variations with longitudinal wavelengths ranging from 25° to 50°, and with vertical wavelengths between 13 and 25 km. These “intermediate‐scale” variations are spatially coherent, and persist for several weeks. Their amplitudes generally increase with altitude, while their phase structures suggest both eastward and westward propagation. The variance of wave numbers 9–17 in the MLT is examined in relation to the underlying stratospheric zonal mean zonal gradient winds. Stronger variances generally coincide with periods where the underlying zonal mean winds are relatively light, or unidirectional. The weak inverse association between variance strength and zonal wind magnitude is suggestive of a wave filtering mechanism.
Ultraviolet climatology over Argentina
Authors: Luccini Eduardo , Cede Alexander , Piacentini Rubén , Villanueva Carlos , Canziani Pablo
Published: September 2006

Satellite‐derived climatologies of UV index (UVI) and erythemal daily dose were determined for Argentina at a geographical resolution of 0.5° latitude by 0.5° longitude. Total Ozone Mapping Spectrometer climatology of key input parameters was used to calculate the clear‐sky ground‐level solar UV irradiance. NASA Surface meteorology and Solar Energy cloud cover data were used to determine the UV attenuation by clouds. Two cases were tested: (1) monthly averages of total cloud cover and (2) monthly averages for three ranges of cloud cover percentage (0–10%, 10–70%, and 70–100%). Case 2, with smaller biases, was selected. Measured erythemal irradiance at seven stations of the Argentine Ultraviolet Monitoring Network was used to validate the satellite‐derived climatologies, as well as to estimate aerosol parameters, surface albedo corrections, and UV cloud transmittance for the calculations. Annual average biases of the monthly mean satellite‐derived UVI and erythemal daily dose with respect to the ground measurements are mostly within ±10%. The strong longitudinal gradient of UV levels toward the Andes Mountains is emphasized. Very high UVI and erythemal daily dose values are registered in the northwestern tropical high‐elevation Andean plateau, with extreme monthly means above 18 and 10 kJ/m2 respectively, in December–January. Even northern low‐elevation regions show averages over 12 and 7 kJ/m2, respectively. On average, clouds attenuate the clear‐sky erythemal irradiance by less than 20% for most of the continental region during all months. UV levels are considerably higher than those for equivalent regions in the Northern Hemisphere.
Large‐scale dynamics of the mesosphere and lower thermosphere: An analysis using the extended Canadian Middle Atmosphere Model
Authors: McLandress C. , Ward W. E. , Fomichev V. I. , Semeniuk K. , Beagley S. R. , McFarlane N. A. , Shepherd T. G.
Published: September 2006

The extended Canadian Middle Atmosphere Model is used to investigate the large‐scale dynamics of the mesosphere and lower thermosphere (MLT). It is shown that the 4‐day wave is substantially amplified in southern polar winter in the presence of instabilities arising from strong vertical shears in the MLT zonal mean zonal winds brought about by parameterized nonorographic gravity wave drag. A weaker 4‐day wave in northern polar winter is attributed to the weaker wind shears that result from weaker parameterized wave drag. The 2‐day wave also exhibits a strong dependence on zonal wind shears, in agreement with previous modeling studies. In the equatorial upper mesosphere, the migrating diurnal tide provides most of the resolved westward wave forcing, which varies semiannually in conjunction with the tide itself; resolved forcing by eastward traveling disturbances is dominated by smaller scales. Nonmigrating tides and other planetary‐scale waves play only a minor role in the zonal mean zonal momentum budget in the tropics at these heights. Resolved waves are shown to play a significant role in the zonal mean meridional momentum budget in the MLT, impacting significantly on gradient wind balance. Balance fails at low latitudes as a result of a strong Reynolds stress associated with the migrating diurnal tide, an effect which is most pronounced at equinox when the tide is strongest. Resolved and parameterized waves account for most of the imbalance at higher latitudes in summer. This results in the gradient wind underestimating the actual eastward wind reversal by up to 40%.
Aerosol black carbon over Bay of Bengal observed from an island location, Port Blair: Temporal features and long‐range transport
Authors: Moorthy K. Krishna , Babu S. Suresh
Published: September 2006

Extensive measurements of the mass concentration of aerosol black carbon (BC) made for about 18 months during 2002–2003 from an island location, Port Blair, in the Bay of Bengal are used to characterize its temporal variations, mass mixing ratio, and association to air mass types. Significantly high concentrations (∼2.4 μg m−3) occur during prevalence of continental air mass, when it also depicts a high mass‐mixing ratio (∼6.5%) to the composite aerosols. Diurnal variations show a nighttime peak and afternoon low, similar to those seen over the mainland, but weaker. Over the years, the concentrations are high during the September to April period, decrease rapidly (by a factor of >3) and continue to do so during the summer monsoon months (June to August). Back trajectory analyses reveal five potential advection pathways, which are seasonal in nature and have a strong influence on the BC concentrations over the island. Concentrations increase significantly, irrespective of air mass types, when the trajectories have long tracks close to and over land areas. The possible implications of the findings on radiative forcing are discussed.
Investigating a floodplain scaling relation using a hydrogeomorphic delineation method
Authors: Nardi Fernando , Vivoni Enrique R. , Grimaldi Salvatore
Published: September 2006

Floodplains are critical landscape features that are highly distinguished from neighboring uplands in terms of their hydrologic, geomorphologic, biogeochemical, and ecological processes. Thus an essential step in floodplain studies is the determination of the lateral floodplain extent and its variability within a basin. Recent advances in topographic mapping and GIS‐based analysis provide a means for developing automated techniques to determine floodplain extent. In this study, we propose a hydrogeomorphic floodplain delineation which links a simplified inundation algorithm with the river basin properties. We utilize the method to investigate the physical controls on floodplain formation, as captured by scaling relations between floodplain width and contributing area. Our hypothesis is that an efficient delineation grounded in hydrogeomorphic theory can improve our understanding of floodplain geometry across a range of conditions. We test the method for two distinct watersheds, a humid catchment in Italy and an ephemeral basin in New Mexico, and note the existence of power law scaling of the floodplain width after averaging over stream orders. An analysis of the algorithm parameters is conducted to identify possible limitations. Further systematic tests are needed to establish the generality of the floodplain scaling and its control on floodplain processes.
Experiments on the effect of hydrograph characteristics on vertical grain sorting in gravel bed rivers
Authors: Hassan Marwan A. , Egozi Roey , Parker Gary
Published: September 2006

Desert ephemeral gravel bed streams typically have bed surfaces that are relatively unarmored compared to the substrate below, while gravel bed streams in humid and snowmelt areas typically have well‐armored surfaces. The degree of armoring can be characterized in terms of an armor ratio defined as the ratio of the surface median size to the substrate median size. A set of field data shows desert ephemeral gravel bed streams with armor ratios ranging from 0.5 to 2.4 and with an average value of 1.2. The armor ratio of snowmelt‐fed gravel bed streams in the same set ranges from 2 to 7, with an average value of 3.4. The reason for this difference is sought in terms of differing hydrological characteristics and sediment supply regimes. Thirteen experiments were conducted to study the formation of armoring under a range of hydrological conditions. The experiments have two limiting cases: a relatively flat hydrograph that represents conditions produced by continuous snowmelt and a sharply peaked hydrograph that represents conditions associated with flash floods. All constant hydrograph experiments developed a well‐armored structured surface, while short asymmetrical hydrographs did not result in substantial vertical sorting. All symmetrical hydrographs show some degree of sorting, and the sorting tended to become more pronounced with longer duration. Sediment supply appears to be a first‐order control on bed surface armoring, while the shape of the hydrograph plays a secondary role.
Does atmospheric processing of saturated hydrocarbon surfaces by NO3 lead to volatilization?
Authors: Knopf D. A. , Mak J. , Gross S. , Bertram A. K.
Published: September 2006

The heterogeneous oxidation of a saturated hydrocarbon monolayer by NO3 was studied. A flow tube reactor coupled to chemical ionization mass spectrometry was used to determine the reactive uptake coefficient of NO3 on these surfaces, and X‐ray photoelectron spectroscopy (XPS) was used to investigate surface oxidation and to determine if exposure to NO3 leads to volatilization of the organic substrate. The uptake coefficient of NO3 by an alkane monolayer is about (8.8 ± 2.5) × 10−4, which may lead to competitive oxidation compared with OH, due to the higher atmospheric abundance of NO3 under certain conditions. The XPS results are consistent with the formation of 1) C‐O groups, 2) ketones or aldehydes, and 3) carboxylic groups. The XPS results also suggest that NO3 does not rapidly volatilize the organic surface: even under extremely polluted conditions, maximum 10% of the organic layer is volatilized.
Assessment of composite global sampling: Sea surface wind speed
Authors: Zhang Huai‐Min , Bates John J. , Reynolds Richard W.
Published: September 2006

Research and forecasts of the weather‐ocean‐climate system demand increasingly higher resolution forcing data. Here we assess the improvement in composite global observations and the feasibility of producing high resolution blended sea winds. The number of the long‐term US sea surface wind speed observing satellites has increased from one in July 1987 to five or more since 2000. Global 0.25° gridded, blended products with temporal resolutions of 6‐hours, 12‐hours and daily have become feasible since mid 2002, mid 1995 and January 1991, respectively (with ≥75% time coverage and ≥90% spatial coverage between 65°S–65°N). If the coverage is relaxed, the feasible times can be extended to earlier periods. These statistics provide practical guidance to produce reliable blended products for different applications, and serve as guidance on the design of future global observing systems.
Evaluation of the Hantush's M(α, β) function using binomial coefficients
Authors: Mamedov B. A. , Ekenoğlu A. S.
Published: September 2006

A new approach is presented for calculating Hantush's M function which arises often in analytical solutions for groundwater pumping models. We develop an algorithm of implementing Hantush's M function calculations, in which binomial expansion theorem is employed. This algorithm is advantageous in the accurate calculation of Hantush's M function. The formulae by which Hantush's M function is expressed are uniform, and their application to the calculation of dynamics of groundwater mounding beneath recharge zones presents no difficulties using a computer. Finally, simple results are presented and discussed.
Alterations in Mammalian Target of Rapamycin Signaling Pathways after Traumatic Brain Injury
Authors: Chen Shaoyi , Atkins Coleen M , Liu Chunli L , Alonso Ofelia F , Dietrich W Dalton , Hu Bingren R
Published: September 2006

In response to traumatic brain injury (TBI), neurons initiate neuroplastic processes through the activation of intracellular signaling pathways. However, the molecular mechanisms underlying neuroplasticity after TBI are poorly understood. To study this, we utilized the fluid-percussion brain injury (FPI) model to investigate alterations in the mammalian target of rapamycin (mTOR) signaling pathways in response to TBI. Mammalian target of rapamycin stimulates mRNA translation through phosphorylation of eukaryotic initiation factor 4E binding protein-1 (4E-BP1), p70 ribosomal S6 kinase (p70S6K), and ribosomal protein S6 (rpS6). These pathways coordinate cell growth and neuroplasticity via dendritic protein synthesis. Rats received sham surgery or moderate parasagittal FPI on the right side of the parietal cortex, followed by 15 mins, 30 mins, 4 h, 24 h, or 72 h of recovery. Using Western blot analysis, we found that mTOR, p70S6K, rpS6, and 4E-BP1 phosphorylation levels were significantly increased in the ipsilateral parietal cortex and hippocampus from 30 mins to 24 h after TBI, whereas total protein levels were unchanged. Using confocal microscopy to localize these changes, we found that rpS6 phosphorylation was increased in the parietal cortex and all subregions of the hippocampus. In accordance with these results, eIF4E, a key, rate-limiting mRNA translation factor, was also phosphorylated by mitogen-activated protein kinase-interacting kinase 1 (Mnk1) 15 mins after TBI. Together, these results suggest that changes in mRNA translation may be one mechanism that neurons use to respond to trauma and may contribute to the neuroplastic changes observed after TBI.
When Perfusion Meets Diffusion: in vivo Measurement of Water Permeability in Human Brain
Authors: Wang Jiongjiong , Fernández-Seara María A , Wang Sumei , Lawrence Keith S St
Published: September 2006

Quantification of water permeability can improve the accuracy of perfusion measurements obtained with arterial spin labeling (ASL) methods, and may provide clinically relevant information regarding the functional status of the microvasculature. The amount of labeled water in the vascular and tissue compartments in an ASL experiment can be estimated based on their distinct diffusion characteristics, and in turn, water permeability determined from the relative vascular and tissue contributions. In the present study, a hybrid magnetic resonance imaging technique was introduced by marrying a continuous ASL method with a twice-refocused spin—echo diffusion sequence. Series of diffusion-weighted ASL signals were acquired with systematically varied b values. The signals were modeled with fast and slow decaying components that were associated with the vascular and tissue compartments, respectively. The relative amount of labeled water in the tissue compartment increased from 61% to 74% and to 86% when the postlabeling delay time was increased from 0.8 to 1.2 and to 1.5 secs. With a b value of 50 secs/mm2 the capillary contribution (fast component) of the ASL signal could be effectively minimized. Using the single-pass approximation model, the water permeability of gray matter in the human brain was estimated based on the derived relative water fractions in the tissue and microvasculature. The potential for in vivo magnetic resonance mapping of water permeability was showed using two diffusion weighted ASL measurements with b = 0 and 50 secs/mm2 in both healthy subjects and a case of brain tumor.
Maternal undernutrition reduces aortic wall thickness and elastin content in offspring rats without altering endothelial function
Authors: Skilton Michael R. , Gosby Alison K. , Wu Ben J. , Ho Lisa M. L. , Stocker Roland , Caterson Ian D. , Celermajer David S.
Published: September 2006

Epidemiological studies suggest a link between fetal/early infant nutrition and adult coronary artery disease. In the present study, we examined the effects of altering nutrition during gestation, lactation and juvenile life on aortic structure and function in rats. Wistar rat dams were fed either a control or low-protein diet throughout pregnancy, or a low-protein diet for the final 7 days of gestation only. At 21 days post-partum, male pups were weaned on to a control, low-protein or high-fat diet. At 12 weeks, the offspring rats were killed. In 46 rats, aortic sections were mounted and stained to assess media thickness and elastin content. In a further 38 rats, aortic rings were suspended in an organ bath and vascular reactivity was tested with dose–response curves to the endothelium-dependent dilator acetylcholine and the endothelium-independent dilator sodium nitroprusside. Rats exposed to maternal protein restriction while in utero had a significantly decreased aortic wall thickness compared with control rats (P=0.005). Total elastin content of the aorta was also decreased by both maternal low-protein (P=0.02) and early postnatal low-protein (P=0.01) diets. Neither maternal nor postnatal low-protein or high-fat diets, however, resulted in any significant changes in arterial dilator function. In conclusion, fetal undernutrition in rats, induced via a maternal low-protein diet, causes a decrease in aortic wall thickness and elastin content without altering aortic dilator function. These changes in vascular structure may amplify aging-related changes to the vasculature and contribute to the pathophysiology of the putative link between impaired fetal growth and adult cardiovascular disease.
Kinetic Th1/Th2 responses of transgenic mice with bacterial meningitis induced byHaemophilus influenzae
Authors: Chen Shyi-Jou , Chu Mong-Ling , Wang Chia-Jen , Liao Ching-Len , Hsieh Shie-Liang , Sytwu Huey-Kang , Wang Chih-Chien
Published: September 2006

To investigate the kinetic Th1/Th2 immunopathogenic mechanisms of Haemophilus influenzae meningitis, we established a murine experimental model of meningitis and elucidated the Th1/Th2 immune responses in T1/T2 doubly transgenic mice based on a BALB/c background under the control of the IFN-γ (interferon-γ)/IL-4 (interleukin-4) promoters respectively. NTHi (non-typeable Haemophilus influenzae) meningitis was induced in these mice by inoculation with either a colonized (CNTHi) or invasive (INTHi) strain of NTHi. Mice inoculated with CNTHi displayed a less severe degree of disease in terms of clinical symptoms, mortality rate and brain histopathology. Conversely, INTHi-inoculated mice had more severe clinical symptoms. CNTHi-inoculated mice had a more significant Th1 response in terms of a higher percentage and longer maintenance of Th1 cells, and more production of IFN-γ from strain-specific antigen-stimulated splenocytes than INTHi-inoculated mice. In contrast, INTHi-inoculated mice had a more significant Th2 response. This was due to a significant increase in IL-4-producing CD4+ T-cells (Th2 cells) and more production of IL-4 from strain-specific antigen-stimulated splenocytes accompanied by a rapid decline of Th1 cells in INTHi-inoculated mice. In conclusion, the preferential Th1/Th2 trend in this murine model of NTHi meningitis is correlated with clinical severity as well as isolated characteristics of the pathogens themselves.
n− 3 Fatty acid supplementation during pregnancy in women with allergic disease: effects on blood pressure, and maternal and fetal lipids
Authors: Barden Anne E. , Dunstan Janet A. , Beilin Lawrence J. , Prescott Susan L. , Mori Trevor A.
Published: September 2006

n−3 Fatty acids derived from fish oil reduce plasma triacylglycerols (triglycerides) and increase HDL-C (high-density lipoprotein cholesterol); however, the effect of n−3 fatty acid supplementation during pregnancy, a hyperlipidaemic state, remains unknown. We took the opportunity to investigate maternal lipid levels and blood pressure during and after pregnancy, and fetal lipid levels at birth, in a study that aimed primarily to examine the effect of fish oil supplementation during pregnancy on immune function in infants born to women with allergic disease. Eighty-three pregnant women who had allergic disease, but were otherwise healthy, completed the study. They were randomly allocated to receive fish oil or olive oil capsules, taken as 4 g/day, from 20 weeks of pregnancy until delivery. Compared with olive oil, fish oil supplementation did not alter triacylglycerols, total cholesterol, LDL-C (low-density lipoprotein cholesterol) or HDL-C during or after pregnancy. There was also no effect of fish oil on cord blood triacylglycerols, total cholesterol, LDL-C or HDL-C. Fish oil supplementation during pregnancy did not alter maternal blood pressure during or after pregnancy. The effects of fish oil on lipids and blood pressure in non-pregnant individuals appear to be lost when it is administered during pregnancy.
Testosterone and vascular reactivity
Authors: Iliescu Radu , Reckelhoff Jane F.
Published: September 2006

The mechanisms by which male sex hormones modulate cardiovascular function are a subject of contemporary interest. Several lines of evidence indicate that androgens can exert acute vasorelaxing effects. On the other hand, chronic exposure to androgens has been shown to promote increases in blood pressure and compromise renal function. In the present issue of Clinical Science, Malkin and co-workers show that testosterone replacement impairs vascular reactivity in men with androgen deficiency. These studies may shed light on the functional and therapeutic significance of the diverging acute and chronic cardiovascular effects of androgens.
Inducible nitric oxide synthase activity does not contribute to the maintenance of peripheral vascular tone in patients with heart failure
Authors: Dover Anna R. , Chia Stanley , Ferguson James W. , Cruden Nicholas L. , Megson Ian L. , Fox Keith A. A. , Newby David E.
Published: September 2006

Enhanced iNOS (inducible nitric oxide synthase) activity may contribute to vascular dysfunction in patients with heart failure. In the present study, we aimed to determine whether iNOS activity contributes to the maintenance of vascular tone in patients with symptomatic heart failure with the use of the highly selective iNOS inhibitor 1400W {N-[3-(aminomethyl)benzyl] acetamidine}. Bilateral forearm blood flow was measured using venous occlusion plethysmography in 12 patients with New York Heart Association class II–IV heart failure and eight matched healthy control subjects during intra-brachial infusion of 1400W (0.1–1 μmol/min), L-NMMA (NG-monomethyl-L-arginine; a non-selective NOS inhibitor; 2–8 μmol/min) and noradrenaline (control vasoconstrictor; 60–480 pmol/min). In both patients and controls, intra-brachial infusion of L-NMMA and noradrenaline caused a dose–dependent reduction in infused forearm blood flow (P<0.05 for both): peak reduction of 32±6% and 37±4% during L-NMMA and 52±6% and 49±5% during noradrenaline respectively (P values were not significant when patients were compared with controls). In contrast, 1400W had no effect on blood flow at 1 μmol/min [−3±4% in patients (95% confidence intervals, −11 to 5%) and 3±8% in controls; P value was not significant]. In conclusion, we have demonstrated that intrabrachial selective iNOS inhibition does not influence forearm blood flow in patients with heart failure. We conclude that iNOS activity does not contribute to peripheral vascular tone in patients with symptomatic heart failure.
Parallel algorithm for the computation of the Hartree-Fock exchange matrix: Gas phase and periodic parallel ONX
Authors: Weber Valéry , Challacombe Matt
Published: September 2006

In this paper we present an efficient parallelization of the ONX algorithm for linear computation of the Hartree-Fock exchange matrix [J. Chem. Phys. 106, 9708 (1997)]. The method used is based on the equal time (ET) partitioning recently introduced [J. Chem. Phys. 118, 9128 (2003)] and [J. Chem. Phys. 121, 6608 (2004)]. ET exploits the slow variation of the density matrix between self-consistent-field iterations to achieve load balance. The method is presented and some benchmark calculations are discussed for gas phase and periodic systems with up to 128 processors. The current parallel ONX code is able to deliver up to 77% overall efficiency for a cluster of 50 water molecules on 128 processors (2.56 processors per heavy atom) and up to 87% for a box of 64 water molecules (two processors per heavy atom) with periodic boundary conditions.
The correlation-consistent composite approach: Application to the G3/99 test set
Authors: DeYonker Nathan J. , Grimes Tom , Yockel Scott , Dinescu Adriana , Mintz Benjamin , Cundari Thomas R. , Wilson Angela K.
Published: September 2006

The correlation-consistent composite approach (ccCA), an ab initio composite technique for computing atomic and molecular energies, recently has been shown to successfully reproduce experimental data for a number of systems. The ccCA is applied to the G3/99 test set, which includes 223 enthalpies of formation, 88 adiabatic ionization potentials, 58 adiabatic electron affinities, and 8 adiabatic proton affinities. Improvements on the original ccCA formalism include replacing the small basis set quadratic configuration interaction computation with a coupled cluster computation, employing a correction for scalar relativistic effects, utilizing the tight-d forms of the second-row correlation-consistent basis sets, and revisiting the basis set chosen for geometry optimization. With two types of complete basis set extrapolation of MP2 energies, ccCA results in an almost zero mean deviation for the G3/99 set (with a best value of −0.10kcalmol−1), and a 0.96kcalmol−1 mean absolute deviation, which is equivalent to the accuracy of the G3X model chemistry. There are no optimized or empirical parameters included in the computation of ccCA energies. Except for a few systems to be discussed, ccCA performs as well as or better than Gn methods for most systems containing first-row atoms, while for systems containing second-row atoms, ccCA is an improvement over Gn model chemistries.
Improved results for the excited states of nitric oxide, including the B∕C avoided crossing
Authors: Shi Huancong , East Allan L. L.
Published: September 2006

The potential energy surfaces of ten electronic states of nitric oxide (NO) have been reexamined computationally, with state energies calculated using ab initio multireference methods. Our wave function expansions of 10×106 configurations improve upon the results of de Vivie and Peyerimhoff [J. Chem. Phys. 89, 3028 (1988)], who obtained excellent results from expansions of 16 000 configurations in 1988. We present results for the adiabatic properties re, Be, Te, and ωe, demonstrating standard errors of 0.012Å, 0.026cm−1, 620cm−1, and 41cm−1, respectively. Vertical excitation energies and oscillator strengths are also presented, as are potential energy surface curves, with special attention to the B∕C avoided crossing. The technical issue of state-averaging effects is also discussed.
Molecular tailoring approach for geometry optimization of large molecules: Energy evaluation and parallelization strategies
Authors: Ganesh V. , Dongare Rameshwar K. , Balanarayan P. , Gadre Shridhar R.
Published: September 2006

A linear-scaling scheme for estimating the electronic energy, gradients, and Hessian of a large molecule at ab initio level of theory based on fragment set cardinality is presented. With this proposition, a general, cardinality-guided molecular tailoring approach (CG-MTA) for ab initio geometry optimization of large molecules is implemented. The method employs energy gradients extracted from fragment wave functions, enabling computations otherwise impractical on PC hardware. Further, the method is readily amenable to large scale coarse-grain parallelization with minimal communication among nodes, resulting in a near-linear speedup. CG-MTA is applied for density-functional-theory-based geometry optimization of a variety of molecules including α-tocopherol, taxol, γ-cyclodextrin, and two conformations of polyglycine. In the tests performed, energy and gradient estimates obtained from CG-MTA during optimization runs show an excellent agreement with those obtained from actual computation. Accuracy of the Hessian obtained employing CG-MTA provides good hope for the application of Hessian-based geometry optimization to large molecules.
Strong non-Arrhenius temperature dependence of the resistivity in the regime of traditional band transport
Authors: Michel C. , Baranovskii S. D. , Klar P. J. , Thomas P. , Goldlücke B.
Published: September 2006

When a strong, though non-Arrhenius temperature dependence of electrical resistivity is observed, one usually concludes that the underlying mechanism is variable-range hopping. Unexpectedly, such observations are also made for many semiconductor systems at elevated temperatures, where a variable-range hopping mechanism seems unlikely. A satisfactory explanation for this observation is still lacking up to now. The authors demonstrate that a non-Arrhenius resistivity behavior may also arise in a band transport picture by thermal activation of charge carriers from a reservoir into the transport-carrying band states, provided the energy distribution of reservoir states is sufficiently broadened or the density of band states exhibits tails.
Spin manipulation using fast cantilever phase reversals
Authors: Budakian R. , Mamin H. J. , Rugar D.
Published: September 2006

The authors show that the phase of a high-Q cantilever can be reversed abruptly, and they use this capability to detect spins for magnetic resonance force microscopy. Spins are manipulated at the cantilever resonant frequency while driving the cantilever with a wave form that has no Fourier component at this frequency. This amplitude-based detection protocol is motivated by the desire to avoid the effects of surface-induced force noise, which can interfere with frequency-based detection schemes. The technique has been applied to the detection of E′ centers and has shown significantly reduced susceptibility to surface noise, resulting in improved signal-to-noise ratio.
Fairly pure ultraviolet electroluminescence from ZnO-based light-emitting devices
Authors: Chen Peiliang , Ma Xiangyang , Yang Deren
Published: September 2006

Fairly pure ultraviolet (UV) electroluminescence (EL) was realized on a ZnO-based metal-insulator (SiOx,x⩽2)-semiconductor structure on a silicon substrate, which was easily fabricated by the reactive direct current sputtering and electron beam evaporation. The UV EL originated from the near-band-edge (NBE) emission of ZnO was achieved at room temperature when the device was under sufficient forward bias with the negative voltage applied on the silicon substrate. Moreover, the intermediate SiOx layer should be thick enough to confine the electrons in the conduction band of ZnO beneath the ZnO∕SiOx interface, which is critical for generation of NBE emission from ZnO.
Crystallization mechanism and piezoelectric properties of solution-derived ferroelectric poly(vinylidene fluoride) thin films
Authors: He Xujiang , Yao Kui
Published: September 2006

β -phase dominant poly(vinylidene fluoride) (PVDF) ferroelectric thin films were obtained on silicon substrates by spin coating the precursor solutions with addition of hydrate salt and drying at an elevated temperature. The remnant polarization of the dense β-phase dominant PVDF thin film was 69.5mC∕m2. The apparent longitudinal piezoelectric coefficient d33 was −17.4pm∕V without taking into account the substrate clamping effect. It was suggested that the hydrate salt functioned as nucleation sites for the crystallization of PVDF molecules, and the intermolecular hydrogen bonding together with dipolar interactions promoted all-trans conformation and β-phase formation.
Annihilation of the OH absorption due to domain inversion in MgO-doped lithium niobate crystals
Authors: Heinemeyer U. , Wengler M. C. , Buse K.
Published: September 2006

The influence of domain inversion on the infrared absorption of lithium niobate crystals with varying MgO doping is investigated. The authors observe a significant difference between crystals doped below and those doped above the so-called optical damage threshold. The shift of the OH absorption due to domain inversion for weakly doped or undoped samples, known from the literature, can be confirmed. However, for highly doped samples the peak vanishes completely after forward poling. It reemerges either by reverse poling or by annealing at 250°C. The mechanism is yet not fully understood but has to be correlated with the defect structure of the crystal.
Electronic transport characterization of silicon wafers by laterally resolved free-carrier absorption and multiparameter fitting
Authors: Zhang Xiren , Li Bincheng , Gao Chunming
Published: September 2006

Laterally resolved modulated free-carrier absorption (MFCA) is applied to the simultaneous determination of the electronic transport properties of semiconductor wafers. A rigorous three-dimensional carrier diffusion model is used to fit the observed dependences of the MFCA signal amplitude and phase on the separation between the pump and probe laser spots, measured at several modulation frequencies covering an appropriate range. This leads to a simultaneous and unambiguous determination of the values of three transport parameters, namely, the minority-carrier lifetime τ, the carrier diffusivity D, and the front surface recombination velocity s1. The extracted values for a n-type Si wafer with a resistivity of 7–10Ωcm are 53μs (τ), 16.6cm2∕s (D), and <200cm∕s (s1), respectively.