29 research outputs found
White-matter microstructural changes in episodic menstrual migraine compared with hormonal controls
Question: Do patients with episodic menstrual migraine exhibit white-matter microstructural changes? Methods: 14 women with episodic menstrual migraine (35±8yrs) were assessed during interictal phase together with 11 healthy women (29±10yrs) during a matching phase of their menstrual cycle (post-ovulation). 2D-EPI multi-shell DWI data were acquired on a 3T Siemens Vida (64-ch coil) and preprocessed using DESIGNER [1]. Diffusion tensor / kurtosis imaging (DTI/DKI) parameter maps were estimated and skeletonised [2] and histogram-metrics were computed for each subject: median, peak height, width, and value. Results: Voxelwise statistical analysis [3] revealed multiple whitematter regions with lower MD and AD in patients, with no differences in FA and RD. Interestingly, migraineurs showed increased MK, AK and RK. Moreover, significant groups differences (Mann- Whitney test with Bonferroni correction) were found in histogram-metrics MD peak value, AD median and peak height and AK median. Median AK was positively associated (Spearman correlation) with disease duration but not with attack frequency and pain intensity. Conclusion: Our findings extended previous reports of whitematter microstructural changes in migraineurs across multiple brain regions [4, 5]. DKI histogram-metrics showed potential as disease biomarkers.info:eu-repo/semantics/publishedVersio
Effect of AGM and Fetal Liver-Derived Stromal Cell Lines on Globin Expression in Adult Baboon (P. anubis) Bone Marrow-Derived Erythroid Progenitors
This study was performed to investigate the hypothesis that the erythroid micro-environment plays a role in regulation of globin gene expression during adult erythroid differentiation. Adult baboon bone marrow and human cord blood CD34+ progenitors were grown in methylcellulose, liquid media, and in co-culture with stromal cell lines derived from different developmental stages in identical media supporting erythroid differentiation to examine the effect of the micro-environment on globin gene expression. Adult progenitors express high levels of γ-globin in liquid and methylcellulose media but low, physiological levels in stromal cell co-cultures. In contrast, γ-globin expression remained high in cord blood progenitors in stromal cell line co-cultures. Differences in γ-globin gene expression between adult progenitors in stromal cell line co-cultures and liquid media required cell-cell contact and were associated with differences in rate of differentiation and γ-globin promoter DNA methylation. We conclude that γ-globin expression in adult-derived erythroid cells can be influenced by the micro-environment, suggesting new potential targets for HbF induction
Should I Stay or Should I Go: Stellar Wind Retention and Expulsion in Massive Star Clusters
Mass and energy injection throughout the lifetime of a star cluster
contributes to the gas reservoir available for subsequent episodes of star
formation and the feedback energy budget responsible for ejecting material from
the cluster. In addition, mass processed in stellar interiors and ejected as
winds has the potential to augment the abundance ratios of currently forming
stars, or stars which form at a later time from a retained gas reservoir. Here
we present hydrodynamical simulations that explore a wide range of cluster
masses, compactnesses, metallicities and stellar population age combinations in
order to determine the range of parameter space conducive to stellar wind
retention or wind powered gas expulsion in star clusters. We discuss the
effects of the stellar wind prescription on retention and expulsion
effectiveness, using MESA stellar evolutionary models as a test bed for
exploring how the amounts of wind retention/expulsion depend upon the amount of
mixing between the winds from stars of different masses and ages. We conclude
by summarizing some implications for gas retention and expulsion in a variety
of compact () star clusters including
young massive star clusters (, ~Myrs), intermediate age clusters (, ~Gyrs), and globular clusters (, ~Gyrs).Comment: 18 pages, 14 figures, version resubmitted to MNRAS after minor
referee comment
Full-time mothers: daily rhythms in brooding and non-brooding behaviors in Brachyuran crabs.
Daily rhythms in activity have been reported for marine and terrestrial organisms, including brooding behaviors which supply oxygen to the embryos of marine invertebrates. Considering that oxygen is a limiting factor in embryo masses of Brachyuran crabs and that female crabs play a critical role in supplying oxygen to the embryos, we studied and compared daily patterns of (1) brooding and nonbrooding behaviors in brooding females, (2) behaviors in nonbrooding females, and (3) oxygen provision to the embryos in a Xanthid crab (Homalaspis plana). We also experimentally evaluated whether daily patterns of nonbrooding behaviors were related to food intake. Behaviors were identified using video recordings and correlated with oxygen analyses in the center of the egg masses by use of microoptodes. According to PO2 recordings abdominal flapping was identified as the single, most important behavior supplying oxygen to the center of the egg mass, maintained at a constant rate during both day and night. Furthermore, the lack of a daily pattern in oxygen availability in the center of the embryo mass is consistent with the lack of daily pattern in abdominal flapping. In contrast, locomotor activity (walking) and maxilliped movements remained unrelated to PO2 oscillations and showed a pronounced diurnal pattern, increasing during the night