bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of the ocean in the Madden–Julian Oscillation: Implications for MJO prediction
Authors: Woolnough S. J. , Vitart F. , Balmaseda M. A. 
Published: February 2007

AbstractThe role of coupled processes in the Madden–Julian Oscillation (MJO) is investigated in the European Centre for Medium‐Range Weather Forecasts Monthly Forecasting System.A series of forecasts initialized daily for 47 days during the Tropical Ocean Global Atmosphere Coupled Ocean Atmosphere Response Experiment (TOGA‐COARE) period are performed with sea surface temperatures (SSTs) provided by persistence of initial conditions, and coupling to either a full dynamical ocean model with vertical resolution in the upper ocean typical of coupled models (10 m), or, a 1D mixed layer ocean model with high (∼1 m) vertical resolution in the upper ocean.The experiment with the full dynamical model shows improved skill compared with the persisted SST experiment, indicating a role for coupled processes in the MJO. The experiment with the mixed layer model shows a further improvement in skill over the full dynamical ocean, particularly for the phases of the MJO where the convection is active over the Indian Ocean or West Pacific. This further improvement comes about from an enhanced sensitivity of the SST to the surface flux anomalies associated with the MJO.Additional sensitivity experiments reveal that the improved representation of the diurnal cycle which results from the increased vertical resolution is a significant factor in the improved skill of the experiments with the mixed layer model. Copyright © 2007 Royal Meteorological Society
Critical re‐evaluation of the bulk transfer coefficient for sensible heat over the ocean during unstable and neutral conditions
Authors: Ann‐Sofi Smedman , Ulf Sahlée , Erik Högström , Cecilia Johansson 
Published: February 2007

AbstractA new analysis of the neutral heat transfer coefficient CHN on data from Östergarnsholm is presented, which is primarily based on a limited set of measurements with the very accurate MIUU (Meteorological Institute of the University of Uppsala) instrument, but with additional information from an extensive set of measurements with Solent sonic R2. Sonic data are, however, used with great caution, since for wind speed U above 10 m s−1, a strongly wind‐speed‐dependent correction is shown to be required. This error is roughly proportional to (U − 10) for sea–air temperature differences less than 4–5 K. For a larger temperature difference, no correction appears to be necessary in the wind speed range 10–15 m s−1.We infer from our data that for conditions when unstable and near‐neutral conditions prevail, measurements of the sea surface—air temperature difference are accurate to within 0.1 K at our site. This means that data for a range of relatively small temperature differences (0.5–1.5 K) which were often rejected in previous studies could be retained. It is observed that a rapid increase of CH and CHN occurs in that range.For wind speed above 10 m s−1, CHN is observed to increase rapidly with U10. During those conditions, the wave field at the site is known to have characteristics very similar to those in deep‐sea conditions. In a previous analysis of data from Östergarnsholm, it was speculated that observed high CHN values could be due to spray. Calculations with a spray model showed, however, conclusively that for wind speeds less than 14 m s−1, the spray effect on the sensible heat flux is expected to be small. The high CHN values must instead be due to dynamic effects.It is demonstrated that when the Obukhov length L is less than about − 150 m a regime with very specific characteristics ensues. This regime is dominated by surface‐layer scale eddies, which cause Monin–Obukhov relations for the exchange of sensible heat to break down. The characteristics of this surface‐layer regime are treated in detail in the companion paper.The rise of CHN with wind speed is shown to be closely related to a corresponding increase of z0T with roughness Reynolds number for winds above 10 m s−1. This means that during those conditions, traditional surface renewal theory for heat is no longer valid. It is suggested that this, in turn, is a result of increasing importance of wave‐breaking with increasing wind and with a possible link to processes in near‐surface atmospheric layers in the regime with −L > 150 m. Copyright © 2007 Royal Meteorological Society
Heat/mass transfer in the slightly unstable atmospheric surface layer
Authors: Smedman Ann‐Sofi , Högström Ulf , Hunt J.C.R. , Sahlée Erik 
Published: February 2007

AbstractIn very slightly unstable conditions, when the Obukhov length is much greater than the surface layer depth, it is observed that the structure of the surface layer turbulence does not accord with standard similarity theory. In particular the efficiency of the turbulent exchange of sensible and latent heat is observed to be more strongly enhanced than is consistent with the standard model. Also the profiles of dissipation of turbulent kinetic energy and temperature fluctuation variance are found to depend on the structure of the whole boundary layer (i.e. are non‐local), indicating that a large‐scale transport process is at work. At the same time, co‐spectral analysis shows how the large‐scale eddy motions that determine the heat transport process near the surface are typically 1/5 of the surface layer depth. All these features are found to be similar in measurements at a marine site and at a flat land site, indicating that they are determined by the dynamics of the whole boundary layer rather than being simply dependent on the surface boundary conditions.We hypothesize that in slightly unstable conditions there is a bifurcation in the structure of the large‐scale eddy motions. This is a transition from quasi‐steady longitudinal roll structures to detached eddies. In the particular regime identified here, the unsteady component dominates the heat transport at the surface. The observed enhancement in the surface layer of the eddy diffusivity of heat is observed to be significantly greater than for momentum. This is shown to be consistent with observations and with a model calculation of the interaction between the surface layer and the descending detached eddies. Copyright © 2007 Royal Meteorological Society
Thermodynamic functions of conformational changes, part IV: Functional analysis of conformational entropy of substituted ethane and methanol
Authors: Viskolcz Béla , Szori Milan , Izsak Robert , Fejer Szilard N. , Csizmadia Imre G. 
Published: February 2007

AbstractThe thermodynamic functions ΔH and ΔS, were computed along the dihedral angle (x) of conformational change for a few selected single rotors: YCH2CH2Y and YCH2OH. The computations were carried out at the B3LYP/6–31G(d,p) level of theory, with 5° increments in x, under very tight optimization condition. The entropy function, S(x), was generated for the full range (0° to 360°) of internal rotation and was subjected to functional analysis. We found the general rule that S(x) had critical points at or near the critical points of ΔH(x); therefore, (dS/dx) vanished for all critical points (minima and transition states) of ΔH(x). However, the entropy derivative also vanished at certain characteristic conformations that were not manifested on the potential energy or enthalpy function. These geometries were classified as “latent minima” or “latent critical points.” The conformational entropy change was related to the relative information (I/I180) of the same state, where the reference state was chosen to be the anti conformation (x = 180°). According to the relationship ln(I/I180) = −ΔS/R, information accumulation was observed in the case of 1,2‐disubtituted ethane and information depletion occurred in the case of fluoromethanol and ethyl alcohol. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Formation of diagnostic product ions from cyanobacterial cyclic peptides by the two‐bond fission mechanism using ion trap liquid chromatography/multi‐stage mass spectrometry
Authors: Mayumi Tsuyoshi , Kato Hajime , Kawasaki Yoshito , Harada Ken‐ichi 
Published: February 2007

AbstractProduct ions obtained by tandem mass spectrometry (MS/MS) are quite effective for the amino acid sequencing of linear peptides. However, in the case of cyclic peptides, the fragmentation pattern is complicated because the cleavages occur randomly and product ions are generated as an, bn, cn, xn, yn and zn series ions; therefore, the authors have never obtained sufficient sequence information. In order to overcome this problem, we applied ion trap liquid chromatography/multi‐stage mass spectrometry (LC/MSn) and characterized the product ions obtained from anabaenopeptins and aeruginopeptins as the cyclic peptides. For the anabaenopeptins, MS2 analysis did not provide sufficient sequence information on the cyclic structure, and MS3 analysis was applied to sequence the constituent amino acids. Diagnostic product ions were obtained by the MS3 analysis and were quite effective for obtaining the sequence information of the constituent amino acids. MS2 analysis was, however, sufficient to obtain the sequence information of the aeruginopeptins. In both cases, the resulting product ions obtained from the cyclic structures were formed by the two‐bond fission mechanism of the precursor ion, in which an initial fission of the cyclic structure to a linear one and subsequent fission(s) at the peptide bonds are included. The fragmentations were similar for the structurally related compounds, indicating that the cleavages occurred at definite peptide bonds. In addition, the resulting product ions are generated as bn series ions and the mass difference facilitates the amino acid sequencing. Thus, ion trap LC/MSn provides sequence information, and the resulting product ions are reproducible among the structurally related compounds and reliable for the sequencing of the constituent amino acids of the cyclic structure. Copyright © 2007 John Wiley & Sons, Ltd.
Mass spectrometric analysis of the individual variability of Bothrops jararaca venom peptide fraction. Evidence for sex‐based variation among the bradykinin‐potentiating peptides
Authors: Pimenta Daniel C. , Prezoto Benedito C. , Konno Katsuhiro , Melo Robson L. , Furtado Maria F. , Camargo Antonio C. M. , Serrano Solange M. T. 
Published: February 2007

AbstractVariation in the snake venom proteome is well documented and it is a ubiquitous phenomenon at all taxonomical levels. However, variation in the snake venom peptidome is so far not described. In this work we used mass spectrometry [liquid chromatography/mass spectrometry (LC/MS) and matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOFMS)] to explore sex‐based differences among the venom peptides of eighteen sibling specimens of Bothrops jararaca of a single litter born and raised in the laboratory. MALDI‐TOFMS analyses showed individual variability among the bradykinin‐potentiating peptides (BPPs), and, interestingly, four new peptides were detected only in female venoms and identified by de novo sequencing as cleaved BPPs lacking the C‐terminal Q‐I‐P‐P sequence. Similar results were obtained with venom from wild‐caught adult non‐sibling specimens of B. jararaca and in this case we were able to identify the gender of the specimen by analyzing the MALDI‐TOF profile of the peptide fraction and finding the cleaved peptides only in female venoms. Synthetic replicates of the cleaved BPPs were less potent than the full‐length BPP‐10c in potentiating the bradykinin hypotensive effect, suggesting that the C‐terminus is critical for the interaction of the BPPs with their mammalian molecular targets. This work represents a comprehensive mass spectrometric analysis of the peptide fraction of B. jararaca venom and shows for the first time sex‐based differences in the snake venom peptidome of sibling and non‐sibling snakes and suggests that the BPPs may follow distinct processing pathways in female and male individuals. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of Dose, Schedule, and Rate of Administration on Radiosensitization by a High‐Concentration Perflubron Emulsion/Carbogen
Authors: Teicher Beverly A. , Herman Terence S. , Holden Sylvia A. , Liu Shide , Menon Krishna 
Published: February 2007

AbstractPerfluorochemical emulsions are highly biocompatible materials which carry and deliver oxygen when a high oxygen content atmosphere is breathed. The concentrated perflubron emulsion Oxygent™CA (Oxygent) used in the current study is a second generation perfluorocarbon emulsion which is much more stable and much more concentrated (90% w/v perflubron) than the earlier preparations. In combination with single dose radiation, a range of Oxygent doses corresponding to perfluorochemical levels from 4 to 12 g/kg led to dose modifying factors from 1.2 to 1.9, respectively. With daily fractionated radiation and daily Oxygent administration over the same dosage range, dose modifying factors from 1.4 to 2.1 were achieved. In general, administration of Oxygent prior to each radiation fraction produced the greatest enhancement in tumor response, although the highest dose of Oxygent administered (12 g/kg) on alternate days with daily carbogen breathing produced a comparable tumor growth delay to 4 g/kg of the perfluorochemical emulsion administered daily with carbogen breathing. Rapid administration of the emulsion was necessary to achieve maximal enhancement of tumor growth delay from this therapeutic adjuvant. These results indicate that dose, schedule of administration, and rate of infusion are important variables to consider in the design of clinical trials to maximize the therapeutic benefit achievable with perfluorochemical emulsions as adjuvants to radiation therapy. © 1993 Wiley‐Liss, Inc.
Effects of Tamoxifen on the Radiosensitivity of Hormonally Responsive and Unresponsive Breast Carcinoma Cells
Authors: Wazer David E. , Joyce Melita , Chan Winnie , Gewirtz David , Lin Peck‐Sun , Solares Guido , Schmidt‐Ullrich Rupert K. 
Published: February 2007

AbstractThe effect of tamoxifen on the radiosensitivity of an estrogen receptor positive (ER+) and an estrogen receptor negative (ER−) breast carcinoma cell line was studied in vitro. Tamoxifen concentrations of 1 and 5 μM inhibited the proliferation of ER+ MCF‐7 cells but had little effect on the growth of ER− MDA‐MB‐231. A 48 hr incubation in tamoxifen increased the proportion of G0/G1 MCF‐7 cells, but minimally altered the cell cycle kinetics of MDA‐MB‐231 cells. Tamoxifen resulted in a small but significant increase in the mean inactivation dose of subconfluent cultures of the ER+ cells but had no effect on the ER− cells. The predominant change for MCF‐7 cells was a decrease in the linear damage coefficient, alpha. This was not associated with any enhanced capacity to recover from split radiation fractions. There was no difference in radiosensitivity comparing irradiated log‐phase to immediately plated plateau‐phase cells. However, 24 hr delayed plating of irradiated plateau‐phase cells resulted in decreased radiosensitivity of a magnitude comparable to that seen with tamoxifen. Quantitation of DNA strand fragmentation revealed no difference in the amount of single or double strand break induction nor the kinetics of strand break repair for cultures irradiated with or without tamoxifen. We conclude that tamoxifen results in a small decrease in the radiosensitivity of proliferating hormone responsive breast carcinoma cells and this effect appears to be most related to delay in cycle progression after release from tamoxifen inhibition. © 1993 Wiley‐Liss, Inc.
Radiotherapy Alone in Breast Cancer:Analysis of Tumor Parameters, Tumor and Lymph Node Doses, Lymph Node Control, Distant Metastasis, and Survival Rates—The Experience of the Gustave‐Roussy Institute and the Princess Margaret Hospital
Authors: Arriagada R. , Mouriesse H. , Sarrazin D. , Deboer G. , Bush R. S. 
Published: February 2007

AbstractThis retrospective analysis involved 453 breast cancer patients treated by radiotherapy alone at the Princess Margaret Hospital and at the Institut Gustave‐Roussy. These patients either had operable tumors, but were unfit for general anesthesia, or had inoperable tumors due to local contraindications to surgery. Results were analyzed according to lymph node response, lymph node recurrence rate, distant metastasis rate, survival rate, tumor size, clinical N category, age, tumor dose, axillary dose, and internal mammary chain irradiation. Multivariate analysis permitted the definition of a risk score for axillary lymph node recurrence (RSLN) according to two independent factors: tumor size and clinical N category. It was shown that the RSLNwas a good single composite prognostic factor for lymph node control. Increase in axillary dose gave a similar effect on the axillary lymph node recurrence relative risk for all the RSLNgroups. According to the slope of the axillary dose‐effect curve, it was deduced that a dose increase of 15 Gy can decrease the relative risk of lymph node recurrence 2‐fold. A similar slope was previously described for tumor dose and local control. A risk score for distant metastases (RSM) was calculated according to three independent prognostic factors: tumor size, clinical N category, and age. The RSMwas not influenced by the tumor or the axillary dose but by the treatment of the internal mammary chain. Similar results were obtained for the risk score for death (RSD). The present data emphasize the role of the lymph node radiation dose in the lymph node control of locally advanced breast cancer. © 1993 Wiley‐Liss, Inc.
Role of Tertiary Collimation for Linac‐Based Radiosurgery
Authors: Smith Vernon , Schell Michael C. , Larson David A. 
Published: February 2007

AbstractFor the stereotactic irradiation of intracranial lesions with a linear accelerator, the use of a tertiary collimating system can be expected to confer several benefits in comparison to the use of the standard linac collimating jaw system. Moving the collimator closer to the patient should lead to reduced penumbra and reduced susceptibility to positioning error. In addition, the use of a circular rather than a square aperture should yield a more advantageous dose distribution for irradiation techniques which follow spherical geometry. An investigation using film dosimetry with a tissue‐equivalent head phantom demonstrated that the tertiary system was superior to the standard jaw system as expected. © 1993 Wiley‐Liss, Inc.
Lumbosacral plexopathy secondary to hyperfractionated radiation therapy: A case presentation and literature review
Authors: Johnstone Peter A. S. , Wasscrmann Eric M. , O'Connell Paul G. , Delaney Thomas F. 
Published: February 2007

AbstractDamage to the lumbosacral plexus is an infrequent complication of radiation therapy to pelvic or spinal lesions. Described is a case of neurologic injury presenting in a young man treated definitively for a paraspinal soft tissue sarcoma. Neurologic symptoms and signs were limited to lower motor neuron deficits without sensory or sphincter disturbances. There remains no evidence of recurrence of the primary lesion. This is the first reported case of lumbosacral plexopathy occurring after a course of hyperfractionated radiotherapy. © 1993 Wiley‐Liss, IncThis article is a US government work and, as such, is in the public domain in the United States of America.
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Investigations into mechanisms of the interaction between platinum complexes and irradiation at low (∼2 Gy) doses in hypoxic cells: I. Role of single‐strand breaks
Authors: Walter P. , Korbelik M. , Spadinger I. , Skov K. 
Published: February 2007

AbstractThere is a need for radiosensitizers, to be used in conjunction with fractionated radiotherapy (∼2 Gy), because of the resistance of the hypoxic portions of tumors. A marked selective interaction between cisplatin (cis‐diamminedichloroplatinum (II)) and low doses of radiations was reported in hypoxic cells [Korbelik and Skov: Radiat Res 119:145–156, 1989]. A first hypothesis might be the interference with repair of radiationinduced DNA breaks by cisplatin, or vice versa. In order to study these possible mechanisms of interaction, the effects of changing the delivery time of cisplatin before and after low‐dose X‐irradiation of hypoxic cells were investigated. Survival after low doses of X‐rays of both Chinese hamster ovary (CHO) and V79 cells growing exponentially was assessed using the Cell Analyzer for location of individual cells. In cells exposed to cisplatin (2.5 μM for 1 hr) and low doses of X‐rays in hypoxia, the pronounced enhancement ratio (ER; 1.7 in CHO, 1.8 in V79) did not decrease regardless of scheduling (up to 8 hr after or 3 hr before irradiation). Since the repair of single‐strand breaks (SSB) is rapid, it appears that interference with their repair is not a major contribution to the interaction. The longer‐term damage (or misrepair) was examined indirectly by looking at 1) colony size: CHO cells which were irradiated with low doses of X‐rays (1 Gy, hypoxia) or treated with cisplatin (2.5 μM) produced smaller colonies than controls; the data for the combined treatments are presented, and 2) chromosome aberrations in hypoxic CHO cells: the ER for exchanges agrees with the survival data. © 1993 Wiley‐Liss, Inc.
Accelerated repopulation during radiotherapy: Quantitative evidence for delayed onset
Authors: Brenner David J. 
Published: February 2007

AbstractThe time of onset of accelerated tumor‐clonogen repopulation produced by radiotherapy is an important, but unresolved question. The suggestion by Withers et al. [Acta Oncol 27:131–146, 1988] and colleagues [Maciejewski and Majewski: Radiother Oncol 21:163–170, 1991] that onset is delayed has been questioned due to the variety of data sources and the methodology used to reach this conclusion. We describe an analysis of a single clinical data set, which allows a more credible estimate of the time of onset of accelerated repopulation. We analyze a recent report of tumor control of T2 and T3 laryngeal cancer as a function of dose and overall time. By virtue of their broad dynamic range, these results allow an estimate to be made of the time of onset of accelerated repopulation based on a single self‐consistent data set. The analyses suggest that rapid proliferation in these tumors is delayed by an estimated 32 days (95% confidence limits of 21–36 days). For these laryngeal tumors, and within the framework of the linear‐quadratic model, the hypothesis that accelerated repopulation begins at the start of radiotherapy can be rejected in favor of the suggestion that accelerated repopulation begins after 3–5 weeks. This conclusion, if generally true, would have significant ramifications for the design of optimized radiotherapeutic protocols. © 1993 Wiley‐Liss, Inc.
Long‐term results of combined modality therapy for esophageal cancer
Authors: Kavanagh Brian D. , Montana Gustavo S. , Crawford Jeffrey , Wolfe Walter G. , Anscher Mitchell S. 
Published: February 2007

AbstractPublished local control and survival rates strongly suggest the superiority of concurrent chemotherapy (CT) and radiotherapy (RT) over RT alone in the management of esophageal cancer, at least in the first 2–3 years after treatment. It is not yet known, however, if these promising early results will be sustained at 5 years and beyond. The present report updates a series that includes 103 patients with clinical stages I—III esophageal cancer treated with combined RT (44–64 Gy) and CT (5‐fluorouracil or etoposide plus cisplatin or carboplatin) either as definite therapy (n = 45) or as pre‐esophagectomy treatment (n = 58). Five year actuarial local control was 53% in the surgery group and 39% in the group without surgery (P < 0.01). Overall survival of both groups was 14% at 5 years. Late local failures and deaths beyond 3 years occurred in both groups. These results, combined with the few other series documenting 5 year outcomes, are not substantially different from 5 year results reported after RT alone. We conclude that extended follow‐up of 5 years or more is necessary before any combined modality regimen can be considered to be superior to single modality therapy for esophageal cancer. © 1993 Wiley‐Liss, Inc.