The Effects of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) on Brown Adipogenesis in Stem Cell Culture

Polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are major maternal dietary supplements due to their positive benefits on neurological tissue growth during the first 12 weeks of gestation. Previous studies show that EPA and DHA inhibit muscle formation but promote adipogenesis. However, no research has addressed the question whether high intake of EPA and DHA affects brown fat development during gestation. The objective of this study was to measure the effect of EPA and DHA supplement on brown adipogenesis and potential pathways related to mitochondrial biosynthesis using fibroblasts as in vitro model. Using Oil-Red-O staining and PCR testing, lipid droplet formation and tested six genes were examined and PGC1α presented statistically significant difference from the control group when treated with PUFAs. Results indicated that PGC1α gene expression can be to be alternated by EPA and DHA treatment. Mitochondrial biosynthesis can potentially be promoted by increased PGC1α gene expression. However, the lipid droplets accumulated in the PUFAs treated group show an unknown mechanism of the n-3 PUFA on adipogenesis that needs to be revealed

Zhat Ting Dere

A poem

Dependence of radio halo properties on star formation activity and galaxy mass

We investigate the relation between the existence and size of radio halos, which are believed to be created by star formation (SF) related energy input into the interstellar medium, and other galaxy properties, most importantly star formation activity and galaxy mass. Based on radio continuum and H-alpha observations of a sample of seven late-type spiral galaxies we find a direct, linear correlation of the radial extent of gaseous halos on the size of the actively star-forming parts of the galaxy disks. Data of a larger sample of 22 galaxies indicate that the threshold energy input rate into the disk ISM per unit surface area for the creation of a gaseous halo depends on the mass surface density of the galaxy, in the sense that a higher threshold must be surpassed for galaxies with a higher surface density. Because of the good prediction of the existence of a radio halo from these two parameters, we conclude that they are important, albeit not the only contributors. The compactness of the SF-related energy input is also found to be a relevant factor. Galaxies with relatively compact SF distributions are more likely to have gaseous halos than others with more widespread SF activity. These results quantify the so-called "break-out" condition for matter to escape from galaxy disks, as used in all current models of the interstellar medium and first defined by Norman and Ikeuchi (1989).Comment: accepted for publication in Astronomy & Astrophysic

Dynamics from seconds to hours in Hodgkin-Huxley model with time-dependent ion concentrations and buffer reservoirs

The classical Hodgkin--Huxley (HH) model neglects the time-dependence of ion concentrations in spiking dynamics. The dynamics is therefore limited to a time scale of milliseconds, which is determined by the membrane capacitance multiplied by the resistance of the ion channels, and by the gating time constants. We study slow dynamics in an extended HH framework that includes time-dependent ion concentrations, pumps, and buffers. Fluxes across the neuronal membrane change intra- and extracellular ion concentrations, whereby the latter can also change through contact to reservoirs in the surroundings. Ion gain and loss of the system is identified as a bifurcation parameter whose essential importance was not realized in earlier studies. Our systematic study of the bifurcation structure and thus the phase space structure helps to understand activation and inhibition of a new excitability in ion homeostasis which emerges in such extended models. Also modulatory mechanisms that regulate the spiking rate can be explained by bifurcations. The dynamics on three distinct slow times scales is determined by the cell volume-to-surface-area ratio and the membrane permeability (seconds), the buffer time constants (tens of seconds), and the slower backward buffering (minutes to hours). The modulatory dynamics and the newly emerging excitable dynamics corresponds to pathological conditions observed in epileptiform burst activity, and spreading depression in migraine aura and stroke, respectively.Comment: 18 pages, 11 figure

The Effects of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) on Brown Adipogenesis in Stem Cell Culture

Polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are major maternal dietary supplements due to their positive benefits on neurological tissue growth during the first 12 weeks of gestation. Previous studies show that EPA and DHA inhibit muscle formation but promote adipogenesis. However, no research has addressed the question whether high intake of EPA and DHA affects brown fat development during gestation. The objective of this study was to measure the effect of EPA and DHA supplement on brown adipogenesis and potential pathways related to mitochondrial biosynthesis using fibroblasts as in vitro model. Using Oil-Red-O staining and PCR testing, lipid droplet formation and tested six genes were examined and PGC1α presented statistically significant difference from the control group when treated with PUFAs. Results indicated that PGC1α gene expression can be to be alternated by EPA and DHA treatment. Mitochondrial biosynthesis can potentially be promoted by increased PGC1α gene expression. However, the lipid droplets accumulated in the PUFAs treated group show an unknown mechanism of the n-3 PUFA on adipogenesis that needs to be revealed

A new species of Boettcheria from Guatemala (Diptera: Sarcophagidae)

Boettcheria styx new species is described from Guatemala, and a key is provided to separate it from B. maerens (Townsend). A list is given of Central American species of Boettcheria with references to figures of their genitalia

Transient localized wave patterns and their application to migraine

Transient dynamics is pervasive in the human brain and poses challenging problems both in mathematical tractability and clinical observability. We investigate statistical properties of transient cortical wave patterns with characteristic forms (shape, size, duration) in a canonical reaction-diffusion model with mean field inhibition. The patterns are formed by a ghost near a saddle-node bifurcation in which a stable traveling wave (node) collides with its critical nucleation mass (saddle). Similar patterns have been observed with fMRI in migraine. Our results support the controversial idea that waves of cortical spreading depression (SD) have a causal relationship with the headache phase in migraine and therefore occur not only in migraine with aura (MA) but also in migraine without aura (MO), i.e., in the two major migraine subforms. We suggest a congruence between the prevalence of MO and MA with the statistical properties of the traveling waves' forms, according to which (i) activation of nociceptive mechanisms relevant for headache is dependent upon a sufficiently large instantaneous affected cortical area anti-correlated to both SD duration and total affected cortical area such that headache would be less severe in MA than in MO (ii) the incidence of MA is reflected in the distance to the saddle-node bifurcation, and (iii) the contested notion of MO attacks with silent aura is resolved. We briefly discuss model-based control and means by which neuromodulation techniques may affect pathways of pain formation.Comment: 14 pages, 11 figure