bluuebunny/crossref_metadata_2025 huggingface dataset:
The demographic characterization of women participating in oocyte donation: a review of 300 consecutively performed cycles
Authors: Sauer M.V. , Ary B.R. , Paulson R.J.
Published: May 2004

OBJECTIVES: To define the demographic characteristics of women participating as oocyte donors and recipients in a gamete donation program. The study took place in the in vitro fertilization program of the University of Southern California (USC‐IVF) and all women who underwent controlled ovarian hyperstimulation for the sole purpose of gamete donation (n = 110), and the recipients of the donated gametes (n = 192) were included. METHODS: Demographic characteristics were tallied for each of the above mentioned groups and reported as means ± S.D. or as percentages as appropriate. Comparisons between recipients were made according to age groups defined by 10‐year age intervals. RESULTS: Oocyte donors were most commonly married mothers in their late twenties who were fully employed. The majority (74%) proffered services anonymously. Recipients differed significantly by age group, with younger patients (< 30 years) being more likely to have been married only once, never to have been pregnant and unlikely to have had previous infertility care. This contrasted with women > 40 years old who were often remarried, likely to have undergone an elective termination of pregnancy, and usually a recipient of extensive infertility care prior to attempts at oocyte donation. CONCLUSIONS: In cases where solicitation of services has not occurred, women donating oocytes may best be described as married, employed, middle class mothers whose primary motivation for participation appears to be altruistic. Significant demographic differences exist between recipients of donated oocytes, which appeared to be age related.
Incidence and contribution of predisposing factors to transverse lie presentation
Authors: Gemer O. , Segal S.
Published: May 2004

OBJECTIVES: Reassessment of predisposing factors to transverse lie presentation. METHODS: Retrospective analysis of delivery data on 92 women with transverse lie presentation, using ultrasonography, and 92 randomly chosen control vertex deliveries. RESULTS: The association between transverse lie and multiparity, prematurity, placenta previa, polyhydramnios and uterine anomalies is reaffirmed. Predisposing factors were found in 66% of primiparas but in only 33% of multiparas. CONCLUSIONS: Known predisposing factors to transverse lie presentation withstood a closer and more accurate assessment of their incidence.
Ear length: A potential sonographic marker for Down syndrome
Authors: Awwad J.T. , Azar G.B. , Karam K.S. , Nicolaides K.H.
Published: May 2004

OBJECTIVES: The purpose of this study was to determine if antenatal sonographic determination of fetal ear length is a useful screening method for identification of fetuses with Down syndrome. METHODS: Ear length measurements were recorded in 418 fetuses undergoing ultrasound scanning between 20 and 28 weeks of gestation. Four trisomy 21 and six trisomy 18 fetuses were identified by karyotyping. The relationship between ear length and gestational age in the normal population was determined by linear regression analysis: expected ear length = −6.000 + 1.075 gestational age. The ability of measured‐to‐expected ear length cut‐off ratios to discriminate between affected and non‐affected fetuses was assessed. RESULTS: The mean ear length and measured‐to‐expected ear length ratios were significantly lower in the affected group as compared to the normal one. A measured‐to‐expected ear length ratio of less than 0.8 was 75.0% sensitive and 98.8% specific in detecting Down syndrome fetuses, and resulted in an 8.5% positive predictive value in the general population. CONCLUSIONS: This preliminary study suggests that antenatal ear length measurements might be a promising sonographic screening method for the detection of Down syndrome in the second trimester of pregnancy.
Management of early ectopic pregnancy
Authors: Popp L.W. , Colditz A. , Gaetje R.
Published: May 2004

OBJECTIVE: Management of early ectopic pregnancy was investigated in a multicenter, prospective study. METHODS: Serum β‐hCG levels were monitored after therapy and correlated to the type of management, gestational age, and initial serum β‐hCG levels in 119 patients with ectopic pregnancies detected at 5–7 postmentrual weeks. RESULTS: Salpingectomy was performed in 16 patients. No postoperative complications were reported. After conservative laparoscopic surgery of 51 ectopic pregnancies, 9 (18%) had delayed decrease or an increase of serum β‐hCG levels. Re‐operations were performed in 4 (7%) patients. Similar findings were noted in 216 patients after conservative operations performed by laparotomy. Intrachorionic injection treatment was sucessful in 17/18 ectopic pregnancies, and expectant management in 7/8 patients with initial serum β‐hCG levels below 250 mIU/ml. CONCLUSIONS: Persistence of trophoblastic activity is a potential complication of conservative surgical treatment of ectopic pregnancy.

A detailed diagnosis as early as 6–7 postmenstrual weeks may be the key for future nonsurgical management of ectopic pregnancy.
Long‐term follow‐up of patients with epithelial carcinoma of the ovary
Authors: Kawai M. , Kikkawa F. , Hattori S. , Ohta M. , Arii Y. , Tomoda Y.
Published: May 2004

OBJECTIVES: To determine the long‐term outcomes of patients with epithelial ovarian cancer. METHODS: A group of 298 patients with epithelial ovarian cancer were treated with combination chemotherapy between July 1979 and January 1986 at the Tokai Ovarian Tumor Study Group. Long‐term results of these patients were analyzed. RESULTS: Five‐year survival and 10‐year survival rates of all the patients were 53% and 47%, respectively. Five‐year survival and 10‐year survival rates for stage I were 89% and 79%, 59% and 56% for stage II, 27% and 22% for stage III, and 9% and 9% for stage IV, respectively. Survival of mucinous and endometrioid cell types were decreased after 5 or more years. In stages II‐IV, cisplatin‐based chemotherapy produced better results than mitomycin‐C, 5‐Fu, cytarabine (MFC) therapy. CONCLUSIONS: Long‐term results of epithelial ovarian cancer were not favorable even in mucinous and endometrioid cell types. For long‐term results, cisplatin‐based chemotherapy was effective in advanced ovarian cancer. Long‐term follow‐up of ovarian cancer is important and necessary.
Pap smear screening and changes in cervical cancer mortality in Sweden
Authors: Mählck C.G. , Jonsson H. , Lenner P.
Published: May 2004

OBJECTIVES: Age‐adjusted incidence of cervical carcinoma has fallen dramatically in Sweden in recent decades. This investigation is an attempt to evaluate the effectiveness of the gynecologic Pap smear screening program in terms of reduction of mortality from cervical cancer. METHODS: Cervical cancer mortality trends in relation to age, calendar period, county and degree of screening activities in the population were analyzed. Multiplicative Poisson regression models were utilized. The reduction of mortality was attributed to the activities of cervical screening. RESULTS: The analysis gave a calculated 53% reduction in cervical cancer mortality (95% confidence limits 23–72%), attributable to screening. CONCLUSIONS: The study supports the hypothesis that gynecological Pap smear screening has had an important impact on the reduction in cervical cancer mortality.
Acute myelogenous leukemia in pregnancy: Fetal blood sampling and early effects of chemotherapy
Authors: Morishita S. , Imai A. , Kawabata I. , Tamaya T.
Published: May 2004

This report documents the acute toxicity of anti‐leukemic chemotherapy on the fetus in utero by umbilical blood sampling. A patient with acute myelocytic leukemia diagnosed at the 23rd week of gestation received combination chemotherapy, and carried the pregnancy to successful delivery at the 34th week. During the course of pregnancy, the fetal condition was evaluated by serial real time sonograms and umbilical blood sampling through cordocentesis. Fetal hemotopoiesis was preserved against maternal chemotherapeutic agents, and no developmental abnormalities were observed. This is the first attempt to evaluate the acute effects of chemotherapeutic agents on the fetus in utero by real time umbilical cord sampling.
Duration of labor in patients delivered vaginally after one previous lower segment cesarean section
Authors: Ziadeh S.M. , Abu‐Heija A.T.
Published: May 2004

OBJECTIVES: To determine the presence or significance of labor patterns in women attempting vaginal birth after a previous cesarean. METHODS: This prospective study was performed for patients who have only had one prior birth by cesarean section. Eighty‐four women who had a cesarean section for failure to progress in labor had a trial of labor. RESULTS: Fifty‐eight were delivered vaginally. This has been matched to nulliparous and multiparous controls. The duration of the first and second stages of labor were similar in the study group and controls. There was no significant difference in oxytocin requirements among the three groups. CONCLUSIONS: Patients who have had a previous cesarean section for failure to progress, have a duration of labor similar to primiparous patients.
Gonadotropin releasing hormone agonist treatment before hysteroscopic endometrial resection
Authors: Vercellini P. , Trespidi L. , Bramante T. , Panazza S. , Mauro F. , Crosignani P.G.
Published: May 2004

OBJECTIVES: To evaluate the effects of treatment with the gonadotropin releasing hormone (GnRH) agonist goserelin before endometrial resection on absorption of distension medium fluid and technical feasibility of the surgical procedure. METHODS: Fifty‐five patients reporting menorrhagia underwent endometrial resection after 2 months of goserelin depot therapy (33 cases) or during the proliferative phase of the cycle (22 controls). RESULTS: In the cases, the mean distension medium deficit ± S.D. was 511 ± 196 ml versus 647 ± 245 ml in controls (P = 0.03), and the operating times were, respectively, 14 ± 4 versus 18 ± 5 min (P = 0.002). The intrauterine operating conditions were considered excellent or good in 64% of the cases versus 27% of the controls (χ2 = 5.60, P = 0.02). CONCLUSIONS: GnRH agonists induce endometrial thinning, so that when administered before intrauterine interventions, mucus cellular debris and bleeding should be reduced during surgery and hysteroscopic visibility increased; the operating time may thus be shorter and fluid absorption decreased. However, more data are needed before considering GnRH agonists a proven effective means of facilitating endometrial resection.
Termination of pregnancy with fetal death in the second and third trimesters — the double balloon versus extra‐amniotic prostaglandin
Authors: Toppozada M.K. , Shaala S.A. , Anwar M.Y. , Haiba N.A. , Abdrabbo S. , El‐Absy H.M.
Published: May 2004

OBJECTIVES: To evaluate the use of a double balloon catheter in the termination of pregnancy with fetal death in the second and third trimesters, in comparison with the administration of extra‐amniotic PGF2‐α. METHODS: Twenty cases with IUFD at > 20 weeks of gestation were divided into two groups. Group I was subjected to the double balloon alone, while in Group II extraamniotic instillation of PGF2‐α via a Foley's catheter was used. RESULTS: There were no significant differences between the two groups with regard to induction‐expulsion time, inductiondelivery time and failure rate. CONCLUSIONS: The double balloon catheter proved to be an effective non‐pharmacological method. The technique was simple and well tolerated by the patients. The side‐effects of the prostaglandin and the cost of the medication were avoided.
Is an intermediate state populated on the folding pathway of ubiquitin?
Authors: Went Heather M. , Benitez-Cardoza Claudia G. , Jackson Sophie E.
Published: May 2004

In the last couple of years, there has been increasing debate as to the presence and role of intermediate states on the folding pathways of several small proteins, including the 76‐residue protein ubiquitin. Here, we present detailed kinetic studies to establish whether an intermediate state is ever populated during the folding of this protein. We show that the differences observed in previous studies are attributable to the transient aggregation of the protein during folding. Using a highly soluble construct of ubiquitin, which does not aggregate during folding, we establish the conditions in which an intermediate state is sufficiently stable to be observed by kinetic measurements.
Besteht ein Zusammenhang zwischen dem Auftreten von positivem Arbeitserleben unter Flow-Bedingungen und Merkmalen der Arbeitstätigkeit?
Authors: Rau Renate , Riedel Stefan
Published: May 2004

Zusammenfassung. Um zu prüfen, ob sich Merkmale der Arbeitstätigkeit zwischen Personen unterscheiden, bei denen ein positives Arbeitserleben unter Flow-Bedingungen (pAF) auftritt, und denen, wo dieses nicht auftritt, wurden 114 berufstätige Männer untersucht. Für jeden Arbeitsplatz wurden eine objektive (TBS-GA) und eine subjektive Arbeitsanalyse (FIT) durchgeführt. Das emotionale Erleben, die erlebte Kontrolle und die Involviertheit in die aktuell ausgeführte Tätigkeit sowie Settingmerkmale wurden stündlich mit einem pocketcomputergestützten Fragebogen in einem Zeitraum von 24 Stunden erfasst. Positives Arbeitserleben unter Flow-Bedingungen wurde operationalisiert über das Bestehen der Flow auslösenden Bedingungen (a) hohe erlebte Kontrolle, (b) überdurchschnittliche geistige Anspannung und (c) Vorliegen eines überdurchschnittlich positiven Erlebens. Im Ergebnis wurden 15 Personen (13 %) mit pAF gefunden. Die Arbeitsplätze dieser Personen waren hinsichtlich der drei TBS-Merkmalsgruppen Lernpotenzial, Verantwortung und Kooperation/Kommunikation besser gestaltet als die von Personen ohne pAF. Dies bildete sich auch in einem als größer bewerteten Tätigkeitsspielraum sowie einem höheren Erfolgserleben im Beruf und einer stärkeren Lebenszufriedenheit bei Personen mit pAF im Vergleich zu denen ohne pAF ab. Insgesamt sprechen die Ergebnisse dafür, dass sich eine gute Arbeitsgestaltung förderlich auf das Befinden während der Arbeit auswirkt.
Auswirkungen von Priming im organisationalen Kontext: Wie nehmen Führungskräfte die eigene Organisation wahr?
Authors: Fischer Peter , Frey Dieter , Greitemeyer Tobias
Published: May 2004

Zusammenfassung. In einem einfaktoriellen Experiment mit drei Treatments wurde untersucht, wie sich Priming auf die Beurteilung der eigenen Organisation auswirkt. Führungskräfte einer deutschen Sparkasse wurden gebeten, sich entweder über (a) positive oder (b) negative Aspekte ihres organisationalen Kontextes Gedanken zu machen, während (c) eine dritte Gruppe von Versuchsteilnehmern Vorschläge generieren sollte, wie das eigene Unternehmen verbessert werden könnte. Führungskräfte, bei denen durch eine Priming-Manipulation ein positives Organisationskonzept aktiviert wurde, identifizierten sich stärker mit der eigenen Organisation, bewerteten das eigene Unternehmen positiver und stuften den eigenen Handlungsspielraum als größer ein im Vergleich zu Führungskräften, bei denen ein negatives Konzept aktiviert wurde. Führungskräfte, die über Verbesserungsvorschläge nachdenken sollten, nahmen das eigene Unternehmen positiver wahr als Führungskräfte, bei denen ein negatives organisationales Konzept geprimt wurde und unterschieden sich nicht von Führungskräften, bei denen ein positives organisationales Konzept aktiviert wurde. Die Bedeutung der Ergebnisse sowohl für die theoretische Forschung als auch die praktische Umsetzung wird diskutiert.
Organisationskultur und Kreativität: Öffnungs- und Schließungsprozesse in Theatern und Forschungsorganisationen
Authors: Boerner Sabine , Gebert Diether
Published: May 2004

Zusammenfassung. Zur Förderung organisationaler Kreativität sind einerseits Öffnungsprozesse, wie z. B. die Förderung individueller Freiheiten, notwendig. Diese Öffnungsprozesse führen jedoch andererseits zu Koordinationsdefiziten, die den Organisationserfolg gefährden. In einer empirischen Studie wird erstmals gezeigt, dass in Forschungseinrichtungen (n = 113 Befragte) und in Theatern (n = 88 Befragte) Öffnungsprozesse stets von parallelen Schließungsprozessen (durch Förderung von Orientierung, Konsens und Vertrauen) begleitet sind. Diese reduzieren die negativen Sekundäreffekte der Öffnung, können sie jedoch im Theater nicht vollständig kompensieren, weil hier ein besonders hoher Koordinationsbedarf besteht. Im Theater wird daher zusätzlich der Grad der Öffnung selbst reduziert, um der Entstehung negativer Sekundäreffekte vorzubeugen.
Rezension der 2. Auflage des Bochumer Inventars zur berufsbezogenen Persönlichkeitsbeschreibung (BIP) von R. Hossiep und M. Paschen
Authors: Marcus Bernd
Published: May 2004

Zusammenfassung. In dem Beitrag wird die zweite Auflage des Bochumer Inventars zur berufsbezogenen Persönlichkeitsbeschreibung (BIP), eines der am weitesten verbreiteten deutschsprachigen Persönlichkeitsinventare für berufliche Anwendungen, kritisch beleuchtet. Insgesamt kann die Neuauflage des BIP aufgrund der berufsbezogenen Konstruktion, der umfangreichen Datenbasis und der überwiegend positiven empirischen Befunde Anwendern empfohlen werden. Die konsequente Berücksichtigung der Perspektive der Testteilnehmer zählt zu den besonderen Stärken des Instruments. Kritisch ist dagegen zu beurteilen, dass auch in der Neuauflage eine Validierung an externen Leistungsbeurteilungen sowie anwendungsspezifische Normen fehlen.
Focal parameters, depth estimation, and plane selection of the worldwide shallow seismicity with Ms ≥ 7.0 for the period 1900–1976
Authors: Selva Jacopo , Marzocchi Warner
Published: May 2004

A worldwide seismic catalog of source parameters is an important tool in many geophysical studies. Such a kind of database is available only since 1977 with the CMT catalog. The main goal of this paper is to compile a similar catalog for the time period 1900–1976 estimating the focal parameters of shallow seismicity (depth ≤ 70 km) with Ms ≥ 7.0 (607 events). In particular, this new catalog (FM0076) contains strike, dip, rake, and depth estimations for 588 earthquakes in the period 1900–1976. At each estimate two reliability flags are assigned. The first is linked to the availability of data, and the second is given by comparing focal mechanism estimations and the tectonics of the epicentral area. The estimation procedure is based on the knowledge of the moment tensor of shallow earthquakes after 1977. From these data, the new concept of Weighted Cumulative Moment Tensor (WCMT), which represents such a kind of moment tensor for a mean earthquake in the epicentral area, leads to estimate the focal parameters. The estimation method is also tested by comparing out our data set for the period 1977–1989 with the CMT one (91 events). This comparison reveals a good agreement between the two methods and confirms the reliability of the catalog FM0076.
Triple cusps observed by Cluster—Temporal or spatial effect?
Authors: Zong Q.‐G. , Fritz T. A. , Zhang H. , Korth A. , Daly P. W. , Dunlop M. W. , Glassmeier K.‐H. , Reme H. , Balogh A.
Published: May 2004

On April 18, 2002, the Cluster spacecraft were outbound in the northern hemisphere over the pole and entered the cusp. A cusp‐like region was observed consecutively three times from 1620 to 1830 UT by all four Cluster Spacecraft although the solar wind dynamic pressure was small and stable. All three cusp encounters were characterized by turbulent magnetic fields, high density plasma and stagnant plasma flow. The cusp region identifications were further confirmed by the clock angle criterion. All three cusps were found to be associated with clear signatures of energetic ions, high He/H and O/H ratios obtained by the RAPID instrument. The observed triple cusps may be either explained as a funnel‐shaped cusp trifurcated or swiveled into a complicated geometry in space or as a cusp which shifted back and forth three times in a two hour interval. Observational evidence shows that the observed triple cusps were a temporal sequence rather than a spatial effect. We suggest further that the solar wind azimuthal flow was the controlling factor of the cusp position and was stronger factor than the IMF BY/BZ components. The importance of the solar wind azimuthal and north/south flow as a dynamic driver of the cusp, and even the whole magnetosphere has been more or less neglected or underestimated.
A statistical approach to Indian Ocean sea surface temperature prediction using a dynamical ENSO prediction
Authors: Kug Jong‐Seong , Kang In‐Sik , Lee June‐Yi , Jhun Jong‐Ghap
Published: May 2004

In this study, a statistical prediction model has been developed to forecast monthly Sea Surface Temperature (SST) in the Indian Ocean. It is a linear regression model based on a lagged relationship between the Indian Ocean SST and the NINO3 SST. A new approach to the statistical modeling has been tried out, in which the model predictors are obtained from not only observed NINO3 SST but also predicted results produced by a dynamical El Niño model. The forecast skill of the present model is better than that of persistence prediction. In particular, the present model has a significantly improved predictive skill during the spring and summer seasons when the boreal summer Indian monsoon is affected by the Indian Ocean SST.
Late‐summer sea ice thickness variability in the Arctic Transpolar Drift 1991–2001 derived from ground‐based electromagnetic sounding
Authors: Haas Christian
Published: May 2004

Late‐summer thickness distributions of large ice floes in the Transpolar Drift between Svalbard and the North Pole in 1991, 1996, 1998, and 2001 are compared. They have been derived from drilling and electromagnetic (EM) sounding. Results show a strong interannual variability, with significantly reduced thickness in 1998 and 2001. The mean thickness decreased by 22.5% from 3.11 m in 1991 to 2.41 m in 2001, and the modal thickness by 22% from 2.50 m in 1991 to 1.95 m in 2001. Since modal thickness represents the thickness of level ice, the observed thinning reflects changes in thermodynamic conditions. Together with additional data from the Laptev Sea obtained in 1993, 1995, and 1996, results are in surprising agreement with recently published thickness anomalies retrieved from satellite radar altimetry for Arctic regions south of 81.5°N. This points to a strong sensitivity of radar altimetry data to level ice thickness.
On the distributions of wave periods, wavelengths, and amplitudes in a random wave field
Authors: Xu Delun , Li Xiang , Zhang Lizhen , Xu Ning , Lu Hongmin
Published: May 2004

On the basis of a narrow‐band Gaussian process, two theoretical probability density functions (PDFs) are derived by applying an approximate Hilbert transform to the process represented by a general form. The first PDF is for the joint distribution of the wave period τ and amplitude ρ of sea waves. It has the same merits as the PDF previously derived by Longuet‐Higgins [1983], in being asymmetric in τ and depending only on the spectral width parameter ν, but gains an advantage that it predicts an exactly Rayleigh distribution of ρ and so facilitates its handling in theory and application in practice. In virtue of the advantage, a relatively simple conditional PDF of τ assuming ρ is derived, which may be used to predict an arbitrarily defined characteristic conditional wave period assuming the wave height from the average wave period. The second PDF is for the joint distribution of wavelengths and amplitudes in a unidirectional Gaussian wave field with narrow spectrum. It has the same form as the first PDF but depends only on the parameter μ defined by μ2 = m0m4/m22 − 1, where mn is the nth moment of spectrum. From this joint PDF, a PDF for the distribution of wavelengths of sea waves is also derived. Numerical simulation and laboratory experiments of wind waves and their results are reported. It is shown that the PDFs derived in this paper give fairly good fits to the simulated data and suitably filtered laboratory data.
Contemporaneous plutonism and strike‐slip faulting: A case study from the Tonale fault zone north of the Adamello pluton (Italian Alps)
Authors: Stipp M. , Fügenschuh B. , Gromet L. P. , Stünitz H. , Schmid S. M.
Published: May 2004

A field, microstructural, and geochronological study of contemporaneous plutonism and strike‐slip faulting along the eastern Tonale fault zone provides new insights into the interrelationships between magmatic emplacement, contact metamorphism and shearing, and it places new time constraints for the Periadriatic Fault System. Although pluton emplacement and shearing were not caused by each other, they mutually interacted during contact metamorphism. The character of the composite Tonale fault zone varies considerably with its proximity to the northern margin of the Adamello pluton, from a paired greenschist facies mylonite belt (Northern mylonite zone) and cataclastic fault zone in the west, to a fault zone consisting of Northern mylonite zone, Cataclastic fault zone and a second mylonite belt (Southern mylonite zone) formed by contemporaneous shearing and contact metamorphism in the east. Ongoing strike‐slip motion led to telescoping and advective cooling of the deforming contact aureole. New U/Pb zircon ages for the northernmost Adamello intrusions (the Avio at 34.6‐1.0 Ma and the Presanella at 32.0‐2.3 Ma) date the onset of contact metamorphism. Rb‐Sr and K‐Ar cooling ages and new zircon fission track ages provide evidence that postintrusive cooling to below 300°C was achieved rapidly, i.e., approximately 30 Myr ago being consistent with a shallow crustal emplacement at ambient temperatures of approximately 250°C. Cataclastic dextral strike‐slip faulting continued until about 20 Ma, when the Tonale fault zone became offset by a number of minor sinistral shears, and by the Giudicarie fault. Hence dextral strike‐slip motion along the Periadriatic Fault System east of the Bergell pluton lasted from approximately 35–20 Myr ago.
Combining surface renewal analysis and similarity theory: A new approach for estimating sensible heat flux
Authors: Castellví F.
Published: May 2004

Castellví et al. [2002] proposed a new approach for estimating sensible heat flux that combined surface renewal analysis and similarity theory. The approach used a calibration parameter (here referred as β) which was introduced by scaling the mean local gradient of air temperature with the ramp amplitude of air temperature over the mean volume of air parcel renewed per unit ground area, traditionally denoted as (αz), with z as the measurement height. Parameter β is explained and determined for half‐hourly samples. It is shown that (kβ) ∼ 0.1 is appropriate under unstable conditions over a variety of canopies, with k as the von Kármán constant. This value is rather robust with regard to height and when measuring in both the roughness and inertial sublayers. This understanding of parameter β allowed a better understanding of parameter α and permitted the derivation of a modified approach for estimating sensible heat flux. In practice, it was possible to consider the new approach exempt from calibration. It was attractive for field applications and showed excellent performance under both stable and unstable conditions. A test was carried out for canopies where fetch requirements and full surface cover were not adequate. It was also shown that the flux variance method required calibration and did not perform as well as the proposed approach under such field conditions.
Estimation of diffusion coefficients, lateral shear stress, and velocity in open channels with complex geometry
Authors: Yang Shu‐Qing , Yu Jian‐Xing , Wang Yuan‐Zhan
Published: May 2004

The lateral distributions of depth‐averaged apparent shear stress, depth mean velocity, and diffusion coefficients are essential in certain quantitative analysis for sediment transport and environmental studies. An analytical method for the computation of these parameters is presented. A mathematical relationship between these parameters, based on the concept of surplus energy transport through a minimum relative distance developed by Yang and Lim [1997], is established, the depth‐averaged apparent shear stress is determined from the boundary shear stress, depth mean velocity is obtained by considering the influence of nonuniform shear velocity and the free surface in 3‐D channels, and the diffusion coefficients are linked to the depth‐averaged apparent shear and velocity. The theoretical formulations for the distributions of depth‐averaged apparent shear stresses, depth mean velocity and diffusion coefficients in trapezoidal and compound channels are presented. Comparisons between the theoretical and the measured lateral distributions of the depth‐averaged apparent shear stresses and the depth mean velocities are also presented, and a reasonable agreement is achieved.
Mass balance errors when solving the convective form of the transport equation in transient flow problems
Authors: Saaltink Maarten W. , Carrera Jesús , Olivella Sebastià
Published: May 2004

The original (divergence) form of the solute transport equation expresses the mass balance of solutes in groundwater. The alternative (convective) form can be obtained by subtracting the flow equation, multiplied by concentration, from the original form. Many investigators prefer the latter because it facilitates the use of Lagrangian or mixed Eulerian‐Lagrangian numerical methods for solution. However, it performs very poorly in transient contaminant transport problems with large temporal variations in water content. We propose an alternative to overcome this difficulty. It consists of evaluating the water content at time level k + 1 − η if concentration in the convective term is evaluated at time level k + η. For this reason we have called it reverse time weighting, whereas we call an evaluation of the water content at time level k + η straight time weighting. We show that reverse time weighting improves significantly over straight time weighting not only in terms of mass balance errors, but also in terms of concentration errors.
Evaluation of bed load transport subject to high shear stress fluctuations
Authors: Cheng Nian‐Sheng , Tang Hongwu , Zhu Lijun
Published: May 2004

Many formulas available in the literature for computing sediment transport rates are often expressed in terms of time mean variables such as time mean bed shear stress or flow velocity, while effects of turbulence intensity, e.g., bed shear stress fluctuation, on sediment transport were seldom considered. This may be due to the fact that turbulence fluctuation is relatively limited in laboratory open‐channel flows, which are often used for conducting sediment transport experiments. However, turbulence intensity could be markedly enhanced in practice. This note presents an analytical method to compute bed load transport by including effects of fluctuations in the bed shear stress. The analytical results obtained show that the transport rate enhanced by turbulence can be expressed as a simple function of the relative fluctuation of the bed shear stress. The results are also verified using data that were collected recently from specifically designed laboratory experiments. The present analysis is applicable largely for the condition of a flat bed that is comprised of uniform sand particles subject to unidirectional flows.
Predicted errors of tropospheric emission spectrometer nadir retrievals from spectral window selection
Authors: Worden John , Kulawik Susan S. , Shephard Mark W. , Clough Shepard A. , Worden Helen , Bowman Kevin , Goldman Aaron
Published: May 2004

Error covariances and vertical resolutions are reported for Tropospheric Emission Spectrometer (TES) nadir‐view retrievals of surface temperature, atmospheric temperature, H2O, O3, CO, and CH4. These error covariances are computed as a result of selecting spectral windows that maximize the information content of simulated, TES nadir‐view atmospheric retrievals of four regions representative of northern midlatitude, southern midlatitude, tropical, and polar climates. The information content of a retrieval is a function of an a priori and an a posteriori covariance matrix where the a posteriori covariance depends on an estimated smoothing error, measurement error, and systematic errors from interfering species, surface emissivity, atmospheric and surface temperature, and line parameter uncertainties. For conditions representative of northern midlatitudes, we can expect about 3 degrees of freedom (DOF) for retrievals of H2O, 5 DOF for O3 with about 2.4 DOF in the troposphere, and 0.8 DOF for CO. These measures for the vertical resolution and the predicted errors can be used to assess which atmospheric science questions can be addressed with TES atmospheric retrievals. Proper characterization of TES retrievals is also critical for applications such as atmospheric data assimilation and inverse modeling.
Role of Red Carotenoids in Photoprotection During Winter Acclimation in Buxus sempervirens Leaves
Authors: Hormaetxe K. , Hernández A. , Becerril J. M. , García‐Plazaola J. I.
Published: May 2004

Abstract: The red leaf coloration of several plant species during autumn and winter is due to the synthesis of phenolic compounds such as anthocyanins or red carotenoids. The latter occur very rarely and are non‐ubiquitous and taxonomically restricted compounds. The present study shows that the leaves of common box (Buxus sempervirens L.) accumulate red carotenoids (eschscholtzxanthin, monoanhydroeschscholtzxanthin, anhydroeschscholtzxanthin) as a response to photoinhibitory conditions during winter acclimation. These compounds are produced in a coordinated manner with the operation of other photoprotective systems: accumulation and sustained deepoxidation of VAZ pigments with a concomitant decrease in maximal photochemical efficiency, accumulation of α‐tocopherol and a gradual decrease on chlorophyll content. All these processes were reversed when the photosynthetic tissues were transferred from photoinhibitory winter conditions to room temperature for 9 days. Buxus leaves showed a large degree of phenotype variation in the degree of reddening, ranging from green to orange. The differences in colour pattern were mainly due to differences in the accumulation of red carotenoids and xanthophyll esters. Red pigments were mainly anhydroeschscholtzxanthin and esters of eschscholtzxanthin. Conversely to fruit or petal chromoplasts, the plastids of red leaves in this species are not the terminal differentiated state but are able to redifferentiate again to chloroplasts. Their photoprotective role during winter as a light screen system or as antioxidants, in a similar way to other red pigments, and their implications on the wide ecological tolerance of this evergreen species are discussed.
Diffusive and Metabolic Limitations to Photosynthesis under Drought and Salinity in C3 Plants
Authors: Flexas J. , Bota J. , Loreto F. , Cornic G. , Sharkey T. D.
Published: May 2004

Abstract: Drought and salinity are two widespread environmental conditions leading to low water availability for plants. Low water availability is considered the main environmental factor limiting photosynthesis and, consequently, plant growth and yield worldwide. There has been a long‐standing controversy as to whether drought and salt stresses mainly limit photosynthesis through diffusive resistances or by metabolic impairment. Reviewing in vitro and in vivo measurements, it is concluded that salt and drought stress predominantly affect diffusion of CO2 in the leaves through a decrease of stomatal and mesophyll conductances, but not the biochemical capacity to assimilate CO2, at mild to rather severe stress levels. The general failure of metabolism observed at more severe stress suggests the occurrence of secondary oxidative stresses, particularly under high‐light conditions. Estimates of photosynthetic limitations based on the photosynthetic response to intercellular CO2 may lead to artefactual conclusions, even if patchy stomatal closure and the relative increase of cuticular conductance are taken into account, as decreasing mesophyll conductance can cause the CO2 concentration in chloroplasts of stressed leaves to be considerably lower than the intercellular CO2 concentration. Measurements based on the photosynthetic response to chloroplast CO2 often confirm that the photosynthetic capacity is preserved but photosynthesis is limited by diffusive resistances in drought and salt‐stressed leaves.
Electron cyclotron resonance plasmas and electron cyclotron resonance ion sources: Physics and technology (invited)
Authors: Girard A. , Hitz D. , Melin G. , Serebrennikov K.
Published: May 2004

Electron cyclotron resonance (ECR) ion sources are scientific instruments particularly useful for physics: they are extensively used in atomic, nuclear, and high energy physics, for the production of multicharged beams. Moreover, these sources are also of fundamental interest for plasma physics, because of the very particular properties of the ECR plasma. This article describes the state of the art on the physics of the ECR plasma related to multiply charged ion sources. In Sec. I, we describe the general aspects of ECR ion sources. Physics related to the electrons is presented in Sec. II: we discuss there the problems of heating and confinement. In Sec. III, the problem of ion production and confinement is presented. A numerical code is presented, and some particular and important effects, specific to ECR ion sources, are shown in Sec. IV. Eventually, in Sec. V, technological aspects of ECR are presented and different types of sources are shown.
Production of highly charged ion beams with the Grenoble test electron cyclotron resonance ion source (plenary)
Authors: Hitz D. , Girard A. , Serebrennikov K. , Melin G. , Cormier D. , Mathonnet J. M. , Chartier J. , Sun L. , Briand J. P. , Benhachoum M.
Published: May 2004

Grenoble Test Source (GTS) is a room temperature electron cyclotron resonance ion source whose purpose is to deepen the knowledge of this type of device. GTS was designed according to magnetic scaling laws determined with the SERSE source [Hitz et al., Rev. Sci. Instrum. 73, 509 (2002); Gammino et al., ibid. 72, 4090 (2001)] while keeping enough flexibility in terms of magnetic confinement and rf heating to determine best conditions for the production of intense beams of any charge state. First results were presented 1 year ago [Hitz et al., 8th European Particle Accelerator Conference, 2002; 15th International Workshop on ECR Ion Sources, 2002]. Since then, some improvements have been performed mostly in the magnetic confinement, beam extraction and analysis. Updated ion beam intensities are presented: e.g., 0.5 mA of Ar11+ at 18 GHz, 20 μA of Ar16+ and 1.8 μA of Ar17+ when GTS is operated at 14.5 GHz. On the other hand, charge coupled device imagers have been installed to diagnose and monitor the ion beam and some beam images are shown.
Self-consistent modeling of electron cyclotron resonance ion sources
Authors: Girard A. , Hitz D. , Melin G. , Serebrennikov K. , Lécot C.
Published: May 2004

In order to predict the performances of electron cyclotron resonance ion source (ECRIS), it is necessary to perfectly model the different parts of these sources: (i) magnetic configuration; (ii) plasma characteristics; (iii) extraction system. The magnetic configuration is easily calculated via commercial codes; different codes also simulate the ion extraction, either in two dimension, or even in three dimension (to take into account the shape of the plasma at the extraction influenced by the hexapole). However the characteristics of the plasma are not always mastered. This article describes the self-consistent modeling of ECRIS: we have developed a code which takes into account the most important construction parameters: the size of the plasma (length, diameter), the mirror ratio and axial magnetic profile, whether a biased probe is installed or not. These input parameters are used to feed a self-consistent code, which calculates the characteristics of the plasma: electron density and energy, charge state distribution, plasma potential. The code is briefly described, and some of its most interesting results are presented. Comparisons are made between the calculations and the results obtained experimentally.
Emittance measurement for intense beam of heavy ions from RIKEN 18 GHz ECRIS
Authors: Higurashi Y. , Kidera M. , Kase M. , Nakagawa T. , Yano Y. , Aihara T.
Published: May 2004

In order to investigate the ion-optical parameters of the RIKEN 18 GHz electron cyclotron resonance ion source injection line into the RIKEN RFQ linac, we measured the beam emittance for a wide mass range of the ions. First results indicate a strong extraction current dependence of the normalized emittance. When using the insertion method to produce metallic ions from solid rod with high melting point, we observed that the beam emittance of metallic ions was very large compared to the beam emittance of ions from gaseous element. It may be due to the plasma instability caused by inserting the rod into the plasma deeply.
Production of intense Fe58, Ni64 beam using the MIVOC method and new analyzing system of RIKEN 18 GHz electron cyclotron resonance ion source
Authors: Kidera M. , Nakagawa T. , Higurashi Y. , Aihara T. , Suzuki N. , Ikezawa E. , Kamigaito O. , Kase M. , Yano Y.
Published: May 2004

As required by the research group of super heavy elements, highly intense beams of Fe58 and Ni64 ions were produced from RIKEN 18 GHz electron cyclotron resonance ion source [Nakagawa et al., Nucl. Instrum. Methods Phys. Res. A 396, 9 (1997)] using the MIVOC method. Maximum intensities of the supplied ion beams were 20 eμA at the extraction voltage of 15.9 kV for Fe13+58 and 90 eμA at the extraction voltage of 17.5 kV for Ni13+64. Consumption rate was about 1.2 mg/h for Fe58 and Ni64, respectively. For the Radio Isotope Beam Factory [Yano, Proceedings of the 15th International Conference on Cyclotron and Their Application [(IOP, Bristol, 1999)] and various requests from users groups, we constructed a double beam injector system for the two ion sources as an external ion source of the Riken Heavy Ion Linear Accelerator [Odera et al., Nucl. Instrum. Methods Phys. Res. A 221, 187 (1984)]. Two ion sources; RAMSES [Arai et al., Nucl. Instrum. Methods Phys. Res. A 491, 9 (2002)] and 18 GHz ECRIS, will be placed at these at the beginning of next year.
Status report on ECR ion sources at HIMAC
Authors: Kitagawa A. , Muramatsu M. , Sasaki M. , Yamada S. , Sakuma T. , Sasaki N. , Takahashi H. , Takasugi W. , Yamamoto M. , Biri S. , Sudlitz K. , Drentje A. G.
Published: May 2004

The Heavy Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of Radiological Sciences (NIRS) is the first heavy-ion accelerator complex dedicated to cancer therapy. Over 1600 patients have already been treated with 140–400 MeV/amu carbon beams since 1994. The production of carbon ions for medical applications has been established. It is quite obvious from our experiences that the ECR ion source is an extremely suitable type of ion source for this purpose. An 18 GHz ECR ion source is mainly operated to offer various heavy-ion beams for basic experiments of biomedical science, physics, chemistry, etc. The results of recent developments, a thermal-controlled MIVOC system, and an electron bombardment evaporator are also reported.
A modified permanent magnet structure for a stronger multipole magnetic field
Authors: Koivisto H. , Suominen P. , Tarvainen O. , Hitz D.
Published: May 2004

The performance of the electron cyclotron resonance ion source (ECRIS) increases proportionally to the microwave frequency squared. This behavior encourages the use of higher microwave frequencies. However, a higher frequency would require a stronger magnetic field for the efficient operation of ECRIS. A rather complicated magnetic field configuration results from the combination of solenoids for the axial confinement and a multipolar radial field usually provided by permanent magnets. These fields produce the so-called B-minimum structure which is required for a stable and efficient operation of ECRIS. The highest multipole field achieved so far in an ECR ion source by using permanent magnets is about 1.3 T. This makes the efficient operation at a microwave frequency of about 18 GHz possible. We introduce here a new approach to further increase the magnetic multipole field provided by permanent magnets. According to our two-dimensional (2D) simulations, a remarkable improvement in the radial magnetic field of the multipole can be achieved. The idea was tested using a simple construction in the plasma chamber of the JYFL 6.4 GHz ECRIS. The multipole field increased from 0.37 to 0.5 T while the solenoids for the axial magnetic field were excited. This result is consistent with our 2D simulations. Based on our simulations and the simple test with the JYFL 6.4 GHz ECRIS, we believe that a multipole field value of 2 T is feasible in ECRIS while still using permanent magnets.
Micro-PHOENIX: Intense deuton beams production for SPIRAL II
Authors: Lamy T. , Curdy J.-C. , Sole P. , Sortais P. , Thuillier T. , Vieux-Rochaz J.-L. , Voulot D.
Published: May 2004

The development of electron cyclotron resonance ion source (ECRIS) at LPSC Grenoble (previously ISN) covers a wide range of applications. Micro-PHOENIX is a compact source whose magnetic confinement is fully generated by permanent magnets. The extraction geometry has been specially designed to manage high currents with a double electrode extraction system to improve the beam characteristics at high voltage. The ECRIS can accept a microwave power frequency from 10 to 18 GHz. It has been installed as a universal injector on the new charge breeder test bench in order to perform the widest range of experiments including mono- or multicharged ion injections. To characterize the analyzed extracted beam, a new emittance meter based on electrostatic deflection plates has been set up and permits one to obtain online high resolution measurements. The first objective of the experiments was to fulfill the future SPIRAL II requirements. After a technical description of the Micro-PHOENIX ECRIS and its beam analysis system, the first experimental results obtained with a single puller electrode will be presented. Thus, a D+ intensity of 5 mA at 39 kV is easily delivered within a normalized rms emittance of 0.092 π mm mrad, which is well below the 0.2 π mm mrad limit assuring a 100% RFQ transport efficiency as computed for the LINAG project. A more extensive study of emittance versus plasma parameters is in progress.
The new ECR ion source DECRIS-4 (project)
Authors: Leporis M. , Bogomolov S. , Efremov A. , Gulbekian G.
Published: May 2004

A new ion source DECRIS-4 for the production of multiply charged ions is planned to be built at the JINR FLNR. The source can be used as an injector of heavy multiply charged ions for the U-400 cyclotron, as well as a “charge breeder” (the “1+→n+” method) for the second phase of the Dubna Radioactive Ion Beams project. The main feature of the ion source design is the creation of the extended resonance zone in a comparatively compact electron cyclotron resonance ion source. For this purpose the axial magnetic field distribution is formed with a flat minimum. Superposition of the axial magnetic field with the field of the permanent magnet hexapole, made from NdFeB, allows one to create a large resonance volume. In this case the electrons can be heated more efficiently. The maximum of the plasma density is situated near the axis, where ions are mainly extracted from. For the plasma heating a microwave frequency of 14 GHz will be used. A preliminary design of the source is described. Also the features and prospects for the application of this source are discussed.
Parallel particle-mesh code for ECR plasma simulation
Authors: Philippov A. V. , Vatulin V. V. , Veselov R. A.
Published: May 2004

The three-dimensional particle-mesh parallel code for ECR plasma simulation is presented.