bluuebunny/crossref_metadata_2025_split huggingface dataset:
Initiating morphological changes associated with long‐term facilitation in Aplysia is independent of transcription or translation in the cell body
Authors: Grabham Peter W. , Wu Fang , Schacher Samuel , Goldberg Daniel J. 
Published: April 2005

AbstractIn Aplysia, the growth of axonal arbor and the formation of new presynaptic varicosities are thought to contribute to long‐term facilitation (LTF) produced by serotonin (5‐HT). While it is known that there is a requirement for both transcription and translation in LTF and in the accompanying morphological changes, the mechanisms mediating the initiation and maintenance of these changes are poorly understood. We used long‐term labeling of the presynaptic sensory neuron to carry out repeated imaging of axonal morphology, coupled with electrophysiology, to further elucidate the macromolecular requirements of this process. Robust synaptic facilitation, axonal growth, and the formation of axonal varicosities were elicited by 5‐HT even when transcription was blocked with actinomycin. Increases in synaptic efficacy and varicosity number were detected 12 h after exposure to 5‐HT but did not persist to 24 h. Even when sensory neuron cell bodies were removed, eliminating the contributions of both somal transcription and translation, 5‐HT elicited these transient morphological and electrophysiological responses. New sensory varicosities contacting the postsynaptic neuron were filled with the neuropeptide sensorin. Under all conditions, global inhibition of protein synthesis completely blocked the formation of new axonal branches and varicosities. These results demonstrate that neither transcription nor somal translation is required to initiate the axonal growth that often accompanies long‐term synaptic plasticity—protein synthesis in the axon is sufficient. Macromolecular synthesis in the cell body is, however, required to maintain the enlarged arbor. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005
Antenatal diagnosis of fetal renal calculus
Authors: Rhodes C. , Churchill D. , Hulton S.‐A. 
Published: April 2005

AbstractPediatric urolithiasis is commonly associated with structural renal tract anomalies and metabolic disorders. Antenatal diagnosis of renal calculi is extremely rare, with only one report in the literature. We present a case of renal stone formation diagnosed at 34 weeks' gestation on ultrasound examination. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Two‐ and three‐dimensional sonographic findings in a case of distal urethral obstruction due to a paraurethral tumor
Authors: Yang J.‐M. , Yang S.‐H. , Huang W.‐C. 
Published: April 2005

AbstractThe cause of bladder outlet obstruction in women may be categorized generally into two types, functional and anatomical. On ultrasonography, the urethra appears as a tubular structure with a central echolucent part and surrounding hyperechogenic structures. Morphological changes in the echolucent portion of the urethra have been reported to be associated with voiding dysfunction. We present a case of distal urethral obstruction secondary to metastatic paraurethral adenocarcinoma. Three‐dimensional sonography clearly demonstrated the configuration of the metastatic tumor and its spatial orientation in association with distal urethral obstruction. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
A novel method to improve prenatal diagnosis of abnormal systemic venous connections using three‐ and four‐dimensional ultrasonography and ‘inversion mode’
Authors: Espinoza J. , Gonçalves L. F. , Lee W. , Mazor M. , Romero R. 
Published: April 2005

AbstractObjectiveThe precise prenatal diagnosis of abnormal venous connections of the fetal heart is challenging. Anatomical accuracy may be important in determining the best route for postnatal angiography, as well as the prognosis and treatment. This study was designed to determine the value of ‘inversion mode’, a new three‐ and four‐dimensional (4D) rendering algorithm, in the visualization of the spatial relationships of an interrupted inferior vena cava (IVC) with azygos or hemiazygos vein continuation associated with and without heterotaxic syndromes.MethodsHeart volumes were acquired using 4D ultrasonography and spatiotemporal image correlation in cases of interrupted IVC with azygos/hemiazygos continuation (n = 3). Volume datasets were rendered using the ‘inversion mode’ algorithm and abnormal images were compared to those generated from a library of normal fetuses.ResultsThe ‘inversion mode’ rendering algorithm allowed the visualization of dilated azygos or hemiazygos veins and their spatial relationships with the descending aorta, the aortic arch, the superior vena cava, and the atria in cases of interrupted IVC with and without heterotaxic syndromes.ConclusionsThe ‘inversion mode’ algorithm improves prenatal visualization of both dilated azygos and hemiazygos veins, as well as their spatial relationships with the surrounding vascular structures. This has implications for the accurate prenatal diagnosis and management of neonates with abnormal systemic venous connections. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Power Doppler vascularity index for predicting malignancy of adnexal masses
Authors: Marret H. , Sauget S. , Giraudeau B. , Body G. , Tranquart F. 
Published: April 2005

AbstractObjectiveTo assess the performance of a power Doppler vascularity index in the preoperative diagnosis of ovarian malignancy.MethodsAdnexal masses (n = 101) were examined prospectively with power Doppler ultrasonography before surgical treatment. The tumor vascularity index (power Doppler index, PDI) was determined by quantification of the number of pixels in a defined region of interest according to the formula: number of colored pixels/(total number of pixels minus the number of pixels in the fluid or avascular areas). It was estimated on selected frames of the tumors using an in‐house color‐quantifying program added to MATLAB 6.0™ software. Inter‐ and intraobserver reproducibilities of PDI assessment were evaluated. Intratumoral blood flow velocity waveforms were obtained to determine the lowest resistance index (RI). A subjective visual score of power Doppler signals in the tumor was used to classify it as having low, moderate or high vascularity. The discriminatory ability of this score was compared to that of RI and PDI measurement.ResultsHistology identified 23 malignant and 78 benign lesions. The PDI was considerably higher in malignant than in benign lesions (0.34 ± 0.04 vs. 0.12 ± 0.06; P < 0.001). The intra‐ and interobserver variabilities of PDI were low (intraclass correlation coefficients of 0.99 and 0.97, respectively). The PDI cut‐off value to differentiate malignant from benign tumors was set at 0.265 (26.5% of the tumor being colored). Using this cut‐off, sensitivity and specificity were 100% (95% CI, 87.8–100.0) and 97.4% (95% CI, 91.0–99.7) compared to 78.3% (95% CI, 56.3–92.5) and 83.1% (95% CI, 72.9–90.7) for RI (cut‐off value of 0.53) and 78.3% (95% CI, 56.3–92.5) and 94.9% (95% CI, 87.4–98.6) for visual scoring. Logistic regression demonstrated that PDI was the best parameter for differentiating between malignant and benign tumors.ConclusionThe power Doppler vascularity index obtained using customized color quantifying software has high diagnostic value in discriminating between benign and malignant adnexal masses. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Increased uterine artery vascular impedance is related to adverse outcome of pregnancy but is present in only one‐third of late third‐trimester pre‐eclamptic women
Authors: Li H. , Gudnason H. , Olofsson P. , Dubiel M. , Gudmundsson S. 
Published: April 2005

AbstractObjectiveSigns of increased uterine artery vascular impedance in mid‐gestation are strongly related to pre‐eclampsia later in pregnancy. Whether this is true for the late third trimester is, however, unclear. The aim of the present study was to analyze the frequency of increased uterine artery vascular impedance in the third trimester, and its relationship to abnormal umbilical artery Doppler and adverse outcome of pregnancy.MethodsThis was a retrospective study of uterine and umbilical artery Doppler velocimetry in 570 pregnancies complicated by pre‐eclampsia. The managing clinician was informed only about the umbilical artery flow. The Doppler recordings were related to severity of pre‐eclampsia, prematurity, fetal growth restriction, and rates of Cesarean section and admission to neonatal intensive care.ResultsIncreased umbilical artery vascular impedance was seen in 59 cases (10.4%), seven having absent or reversed end‐diastolic flow. Uterine artery notching was seen in 145 cases (25%), 88 (15%) having bilateral notches. Either increased uterine artery pulsatility index (PI) or notching, or both, were seen in 207 women (36.3%). In 108 women with severe pre‐eclampsia, 38 (35.2%) had uterine artery notching. Signs of increased uteroplacental vascular impedance were more common in severe than in mild pre‐eclampsia (57.4% vs. 31.4%), in premature than in term pregnancies (70.9% vs. 28.4%), and were more prevalent than abnormality in the umbilical artery (36.3% vs. 10.4%).ConclusionOnly one‐third of pre‐eclamptic cases showed signs of increased uterine artery vascular impedance in the third trimester. However, signs of increased vascular impedance were much more frequent in the uterine than in the umbilical arteries and were strongly related to adverse outcome of pregnancy. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.
Impact of ionizing radiation on the life cycle of Saccharomyces cerevisiae Ty1 retrotransposon
Authors: Sacerdot Christine , Mercier Géraldine , Todeschini Anne‐Laure , Dutreix Marie , Springer Mathias , Lesage Pascale 
Published: April 2005

AbstractTy1 elements, LTR‐retrotransposons of Saccharomyces cerevisiae, are known to be activated by genetic and environmental stress. Several DNA‐damaging agents have been shown to increase both Ty1 transcription and retrotransposition. To explore further the relationship between Ty1 mobility and DNA damage, we have studied the impact of ionizing radiation at different steps of the Ty1 life cycle. We have shown that Ty1 transposition is strongly activated by γ‐irradiation and we have analysed its effect on Ty1 transcription, TyA1 protein and Ty1 cDNA levels. The activation of transposition rises with increasing doses of γ‐rays and is stronger for Ty1 elements than for the related Ty2 elements. Ty1 RNA levels are markedly elevated upon irradiation; however, no significant increase of TyA1 protein was detected as measured by TYA1–lacZ fusions and by Western blot. A moderate increase in Ty1 cDNA levels was also observed, indicating that ionizing radiation can induce the synthesis of Ty1 cDNA. In diploid cells and ste12 mutants, where both Ty1 transcription and transposition are repressed, γ‐irradiation is able to activate Ty1 transposition and increases Ty1 RNA levels. These results suggest the existence of a specific regulatory pathway involved in Ty1 response to the γ‐irradiation that would be independent of Ste12 and mating‐type factors. Our findings also indicate that ionizing radiation acts on several steps of the Ty1 life cycle. Copyright © 2005 John Wiley & Sons, Ltd.
Two new fungal inteins
Authors: Butler Margaret I. , Goodwin Timothy J. D. , Poulter Russell T. M. 
Published: April 2005

AbstractUntil recently the only intein known to be encoded by the nuclear genome of a eukaryote was the VMA intein in the vacuolar ATPase precursor of several species of saccharomycete yeast. This intein has been intensively studied and much information has been gained about its structure, mode of action and evolutionary history. We recently reported a second nuclear intein, Cne PRP8, encoded within the PRP8 gene of the basidiomycete Cryptococcus neoformans. Subsequent studies have found allelic PRP8 inteins in several species of yeast and filamentous ascomycetes. Here we report two further, non‐allelic, inteins from ascomycete species. The yeast Debaryomyces hansenii (which also has a VMA intein) has an intein encoded within the sequence of the glutamate synthase gene (GLT1). There are also inteins encoded in the homologous GLT1 genes of the yeast Candida (Pichia) guilliermondii and the filamentous fungus Podospora anserina. These allelic GLT1 inteins occupy exactly the same site in the glutamate synthase and all contain domains that indicate the presence of a homing endonuclease (HEG). Podospora anserina, in addition, contains a second, non‐allelic, intein encoded in the chitin synthase gene (CHS2); this intein also contains a HEG domain. We describe the phylogenetic relationships among the four eukaryote nuclear encoded inteins (VMA, PRP8, GLT1 and CHS2). We also consider this phylogeny in the broader context of eubacterial, archaeal and eukaryote viral and organelle inteins. Copyright © 2005 John Wiley & Sons, Ltd.
23,000 yr of vegetation history of the Upper Lerma, a tropical high-altitude basin in Central Mexico
Authors: Lozano-GarcÍa Socorro , Sosa-Nájera Susana , Sugiura Yoko , Caballero Margarita 
Published: April 2005

AbstractPollen analysis on a 9.54-m sediment core from lake Chignahuapan in the upper Lerma basin, the highest intermontane basin in Central Mexico (2570 m asl), documents vegetation and limnological changes over the past ∽23,000 14C yr. The core was drilled near the archaeological site of Santa Cruz Atizapán, a site with a long history of human occupation, abandoned at the end of the Epiclassic period (ca. 900 AD). Six radiocarbon AMS dates and two well-dated volcanic events, the Upper Toluca Pumice with an age of 11,600 14C yr B.P. and the Tres Cruces Tephra of 8500 14C yr B.P., provide the chronological framework for the lacustrine sequence. From ca. 23,000 14C yr B.P. to ca. 11,600 14C yr B.P. the plant communities were woodlands and grasslands based on the pollen data. The glacial advances MII-1 and MII-2 correlate with abundant non-arboreal pollen, mainly grasses, from ca. 21,000 to 16,000 14C yr B.P., and at ca. 12,600 14C yr B.P. During the late Pleistocene, lake Chignahuapan was a shallow freshwater lake with a phase of lower level between 19,000 and 16,000 14C yr B.P. After 10,000 14C yr B.P., tree cover in the area increased, and a more variable lake level is documented. Late Holocene (ca. 3100 14C yr B.P.) deforestation was concurrent with human population expansion at the beginning of the Formative period (1500 B.C.). Agriculture and manipulation of the lacustrine environment by human lakeshore populations appear at 1200 14C yr B.P. (550 A.D.) with the appearance of Zea mays pollen and abundant charcoal particles.
Quetiapine: Results of four phase II and III clinical trials
Authors: King DJ 
Published: April 2005

SummaryThe data on efficacy and tolerance from four (phase II and III) trials of quetiapine (Seroquel® or ICI 204,636) in a total of 1,461 patients with acute exacerbations of chronic or sub-chronic schizophrenia are briefly reviewed. Together, the results of these trials have demonstrated antipsychotic efficacy in comparison with placebo and equivalent efficacy to haloperidol. In spite of its short plasma elimination half-life, quetiapine is equally effective when given in twice-daily and three-time daily doses. The optimum dose is between 300 mg and 400 mg per day, and the main and most consistent adverse effect is sedation. It has a low extrapyramidal side effect liability and does not produce sustained elevations in plasma prolactin levels.
Treatment with antipsychotics: The impact on the patient in the community
Authors: Rössler W , Salize HJ , Reinhard I 
Published: April 2005

SummaryThe assessment of new treatment strategies such as the atypical antipsychotic agents goes far beyond the assessment of psychopathology, and includes evaluation of their effects on a variety of needs associated with living in the community. This article provides some empirical data for such a multidimensional perspective in analysing drug treatment with conventional antipsychotics. We focus on two groups of schizophrenic patients discharged from a psychiatric hospital, who were followed up for one year. One group was treated with oral and the other with depot medication. The two groups were assessed on their needs for care, quality of life, and rehospitalisation rates. We found few significant differences between depot- and orally-medicated patients. However, patients treated with depot antipsychotics were receiving higher mean daily doses. Patients taking oral medication had a lower rate of adverse effects but were more non-compliant, which resulted in a higher rehospitalisation rate, confirming our assumpt on that patients take different risk-to-benefit decisions. Orally-medicated patients did not have a better functional status than depot-medicated patients.
Hot-Cathode Arcs in Cesium Vapor
Authors: Steinberg Richard K. 
Published: April 2005

A hot-cathode arc in cesium vapor has been studied by the use of a plane Langmuir probe to investigate the potential distribution, electron temperature and electron density in the plasma. The range of arc currents and vapor pressures over which satisfactory probe measurements may be made are determined.
In some cases it was possible to maintain the discharge with a total arc drop of less than the ionization potential of cesium (3.87 volts). Potential ``humps'' along the arc are shown to be absent, and ionization by the high energy electrons of a Maxwellian electron velocity distribution is found unsatisfactory as a possible mechanism for positive ion production in the arc. The mechanism of successive electron collisions can account for the observed ionization on the assumption that the effective lifetime in the excited state is increased by the process of the imprisonment of resonance radiation.
The Effect of Input Configuration on Antenna Impedance
Authors: Whinnery J. R. 
Published: April 2005

It is known that the configuration of the input driving system may be of importance to the impedance of antennas at high frequencies. In this paper, a region in the vicinity of the input is considered as a transducer between the TEM mode on the driving transmission line and the spherical nearly-TEM mode on the antenna system, and the constants of this transducer are found both by calculation and measurement for a particular case. The calculation is based upon quasi-static concepts, utilizing an electrostatic field map obtained from an electrolytic tank to give the approximate form of the electric field lines. The measurement is made by finding three input reactances corresponding to the input region closed by three spun aluminum hemispheres of different radii. The three sets of data, taken at each frequency, are sufficient to determine the constants of the transducer. They are expressed here as a pi-network for comparison with calculated values.The main portion of the antenna is analyzed substantially as in Schelkunoff's approach, with the TM modes in space and in the antenna region expressed as a shunt admittance at the end of the antenna in the TEM mode equivalent circuit. This admittance is then transformed to the desired reference on the antenna by a perturbation calculation. From there it is transformed to a desired reference on the feed line by means of the input network constants. Values calculated in this way are compared with measured values over the range 200 to 1000 mc/sec. for the particular monopoles studied. Agreement is not perfect, but appears considerably better than without consideration of the specific input configuration.
Space-Charge Effects in Electron Beams and Their Reduction by Positive Ion Trapping
Authors: Linder E. G. , Hernqvist K. G. 
Published: April 2005

The spread of electron beams caused by space-charge forces is discussed. Under certain conditions ions formed from the residual gas may be trapped in the beam. An equilibrium condition may be established in which the electron and ion densities are equal, and then space-charge forces will be neutralized. Under these conditions high current densities may be produced at low voltages. A theory of ion trapping is discussed, and the equilibrium condition is formulated.Experimental data are presented which were obtained by the application of microsecond pulses to the beam. This technique is described, and its advantages and possibilities are mentioned. Data are given on beam spread as a function of current, voltage and pressure. Data on the improvement due to ion trapping are included. An increase of current density by a factor of 30 was observed with the structures tested. Results are included on ion build-up time as a function of pressure, and on beam noise and stability in the presence of trapped ions.
Frequency Factor and Activation Energy for the Volume Diffusion of Metals
Authors: Dienes G. J. 
Published: April 2005

The theoretical equations proposed for calculating D0 of the diffusion-constant-temperature relation D=D0e−E/RT are critically discussed in the light of presently available data. It is concluded that none of the relations gives satisfactory agreement with experiment.
Empirical analysis of experimental data covering a wide range of D0 and E values showed that the quantity E/Tm, where Tm is the melting point in °K, is the main factor in determining the value of D0, and that D0 depends approximately exponentially on E/Tm. In addition to many other diffusion constants, it is shown that the anisotropic diffusion of zinc and the widely differing diffusion constants for self-diffusion in α- and γ-iron are included in the proposed empirical correlation.
A possible theoretical basis for the empirical correlation is described based on the idea of local melting or disordering. The quantity E/Tm is identified with the entropy of activation.
Plastic Flow of Platinum Wires
Authors: Carreker R. P. 
Published: April 2005

The strain-time behavior of annealed platinum wires at constant stress and temperature is reported for a wide range of experimental conditions, namely: 1550 to 78°K, 900 to 40,000 p.s.i., 0.001 to 0.1 strain, 10−1 to 10−6 min.−1 strain rate.
The following relations were found to describe the results satisfactorily: σ=Aε̇n|ε,T;   σ=BepT|ε,ε̇,ε=Cta|σ,T;   Q∼logσ|ε;   ∂n∂T=∂p∂logε̇|ε,where σ=stress, ε=strain, σ=strain rate, T=absolute temperature, Q=activation energy for rate of deformation, t=time, and A, B, C, a, n, and p are constants.
Production of 2537 Radiation and the Role of Metastable Atoms in an Argon-Mercury Discharge
Authors: Kenty Carl 
Published: April 2005

The average population of 63P1 mercury atoms is calculated from the measured 2537 output and resonance radiation diffusion theory. Average populations of 63P2, 0 are then found by comparing the absorptions of 5461, 4358, and 4047. Populations for a 0.42-amp. discharge in 3.5-mm argon of high purity plus Hg vapor at 42°C in a tube 1½ inches in diameter are for 63P2, 1, 0, respectively, 7.6×1011, 1.9×1011, and 3.5×1011 cm−3; these are ⅕, 1/20, and ⅕ of the corresponding Boltzmann populations, for the electron temperature of 11,100°K.
Rates of collisions of the first and second kinds involving electrons (average concentration 2.1×1011 cm−3), and the 61S0 and 63P2, 1, 0 states are calculated using known excitation functions and detailed balancing. The results predict populations for 63P2, 1, 0 within 10 percent of those observed; they further predict that ⅔ of the observed 2537, ⅔ of the visible triplet, and ¾ of the 3650 group are produced stepwise via 63P. Quenching collisions involving argon are assumed negligible.
The results account fairly well for the maximum in the 2537 versus Hg pressure curve, for the decrease in the 2537 output efficiency with increasing current, and for the decrease in electron temperature which is associated with both these effects.