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Considerable Fraction (considerable + fraction)

Distribution by Scientific Domains

Medical Sciences	33%

Selected Abstracts

Reduced expression of MYO18B, a candidate tumor-suppressor gene on chromosome arm 22q, in ovarian cancer

INTERNATIONAL JOURNAL OF CANCER, Issue 1 2004
Nozomu Yanaihara
Abstract Allelic imbalance on chromosome arm 22q has been detected in 50,70% of ovarian cancers, suggesting the presence of a tumor-suppressor gene on this chromosome arm that is involved in ovarian carcinogenesis. Recently, we isolated a candidate tumor-suppressor gene, MYO18B, at 22q12.1, which is deleted, mutated and hypermethylated in approximately 50% of lung cancers. In our study, we analyzed genetic and epigenetic alterations of the MYO18B gene in ovarian cancers. Missense MYO18B mutations were detected in 1 of 4 (25%) ovarian cancer cell lines and in 1 of 17 (5.9%) primary ovarian cancers. MYO18B expression was reduced in all 4 ovarian cancer cell lines and in 12 of 17 (71%) of primary ovarian cancers. MYO18B expression was restored by treatment with 5-aza-2,-deoxycytidine and/or trichostatin A in 3 of 4 cell lines with reduced MYO18B expression, and hypermethylation of the promoter CpG island for MYO18B was observed in 2 of these 3 cell lines. Its hypermethylation was also observed in 2 of 15 (13%) primary ovarian cancers. Thus, it was indicated that MYO18B expression is reduced in a considerable fraction of ovarian cancers by several mechanisms, including hypermethylation, while the MYO18B gene is mutated in a small subset of ovarian cancers. The present results suggest that MYO18B alterations, including both epigenetic and genetic alterations, play an important role in ovarian carcinogenesis. © 2004 Wiley-Liss, Inc. [source]

On the reliability of fully automatic indexing of electron diffraction patterns obtained in a transmission electron microscope

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 1 2006
E. Bouzy
Orientation maps similar to electron backscatter diffraction maps can be obtained in a transmission electron microscope. A method of such mapping by automatic indexing of electron diffraction patterns has been proposed recently. The procedure is relatively simple and fast but it does not avoid the ambiguity. Using tests on simulated patterns, it is shown that under current practice automatic indexing may give a considerable fraction of erroneous solutions. Optimization of measurement conditions leading to a reduction of that fraction is considered. [source]

Hydrodynamic Size and Electrophoretic Mobility of Poly(styrene sulfonate) versus Molecular Weight,

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 19-20 2007
Ute Böhme
Abstract The effective charge of a macromolecule in solution is significantly smaller than the nominal charge, derived form the number of charged groups and the degree of dissociation. It is reduced by counterion condensation, shielding a considerable fraction of the macromolecules charge. As an example the influence of the molecular weight on hydrodynamic size and electrophoretic mobility of poly(styrene sulfonate) has been investigated. While from diffusion the hydrodynamic size is inferred, in a combination with electrophoresis NMR the effective charge is calculated. At low molecular weight the effective charge is equal to the nominal charge, in an intermediate range the effective charge is that predicted from counterion condensation theory, while at higher molecular weights it becomes considerably smaller. [source]

Brown dwarf candidates in the Serpens cloud core,

ASTRONOMISCHE NACHRICHTEN, Issue 1 2006
C. Eiroa
Abstract The Serpens cloud core is populated by a young, low-mass stellar cluster with members in many different evolutionary stages. We revisit the near-IR properties of the cluster in this contribution. A total of 188 near-IR sources are identified, including new members suggested in this work. Near-IR colour-magnitude and colour-colour diagrams allow us to suggest 42 objects among the cluster members as brown dwarf candidates. A considerable fraction of them present near-IR excesses which indicates that many of these very low mass objects are still surrounded by prominent dust accretion disks. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Ruminant-mediated Seed Dispersal of an Economically Valuable Tree in Indian Dry Forests,

BIOTROPICA, Issue 5 2006
Soumya Prasad
ABSTRACT Ruminant-mediated seed dispersal, an understudied process in tropical forests, was examined via Phyllanthus emblica,Axis axis interaction. A captive Axis deer regurgitated intact P. emblica seeds after retaining them in the rumen for 7,27 h. At Rajaji National Park, a considerable fraction (22%) of deer-regurgitated P. emblica seeds germinated, although lower than unconsumed seeds (72%). The size and strength of seeds like P. emblica might ensure that ruminants regurgitate them intact instead of defecating them. [source]

Seizures in the intrahippocampal kainic acid epilepsy model: characterization using long-term video-EEG monitoring in the rat

ACTA NEUROLOGICA SCANDINAVICA, Issue 5 2009
R. Raedt
Objective,,, Intrahippocampal injection of kainic acid (KA) in rats evokes a status epilepticus (SE) and leads to spontaneous seizures. However to date, precise electroencephalographic (EEG) and clinical characterization of spontaneous seizures in this epilepsy model using long-term video-EEG monitoring has not been performed. Materials and Methods,,, Rats were implanted with bipolar hippocampal depth electrodes and a cannula for the injection of KA (0.4 ,g/0.2 ,l) in the right hippocampus. Video-EEG monitoring was used to determine habitual parameters of spontaneous seizures such as seizure frequency, severity, progression and day,night rhythms. Results,,, Spontaneous seizures were detected in all rats with 13 out of 15 animals displaying seizures during the first eight weeks after SE. A considerable fraction (35%) of the spontaneous seizures did not generalize secondarily. Seizure frequency was quite variable and the majority of the KA-treated animals had less than one seizure per day. A circadian rhythm was observed in all rats that showed sufficient seizures per day. Conclusions,,, This study shows that the characteristics of spontaneous seizures in the intrahippocampal KA model display many similarities to other SE models and human temporal lobe epilepsy. [source]