Searching for electromagnetic counterpart of LIGO gravitational waves in the Fermi GBM data with ADWO

The Fermi collaboration identified a possible electromagnetic counterpart of the gravitational wave event of September 14, 2015. Our goal is to provide an unsupervised data analysis algorithm to identify similar events in Fermi's Gamma-ray Burst Monitor CTTE data stream. We are looking for signals that are typically weak. Therefore, they can only be found by a careful analysis of count rates of all detectors and energy channels simultaneously. Our Automatized Detector Weight Optimization (ADWO) method consists of a search for the signal, and a test of its significance. We developed ADWO, a virtual detector analysis tool for multi-channel multi-detector signals, and performed successful searches for short transients in the data-streams. We have identified GRB150522B, as well as possible electromagnetic candidates of the transients GW150914 and LVT151012. ADWO is an independently developed, unsupervised data analysis tool that only relies on the raw data of the Fermi satellite. It can therefore provide a strong, independent test to any electromagnetic signal accompanying future gravitational wave observations.Comment: 4 pages and 4 figures, A&A Letters accepte

Regulatory components involved in cold tolerance of barley cells

Micro- and macroclimatic changes fundamentally determine growth rate, development, crop production and geographical distribution of plant species. The existence of successful defensive mechanisms against the damaging effects of low temperature is essential for survival and sufficient seed production of plants. In winter-type cereals cold acclimation process is activated by low temperature, and it leads to elevated level of resistance against harmful physiological effects of suboptimal temperature. One of the most important gene expression regulator units in this mechanism is the CBF-COR system. However, cold acclimation mechanism is a very complex phenomenon, the process is influenced by many factors, e.g. falling temperature, day length, spectral composition of irradiated light, as well as local and systemic internal signals. Because of this, realignment of the gene expression pattern connected to the cold acclimation mechanism and its phenotypical effects is very difficult to investigate excluding the influence of other factors with interfering action. Basic cellular and biochemical changes caused by only the low temperature, independently of another factors mentioned above are mainly undiscovered. Therefore, elemental cold response of the CBF-COR system was compared in seedlings and dark-grown, dedifferentiated, meristemoid callus cultures of winter barley. Detailed characteristics of CBF-COR induction and effects of cold-hardening were also studied in barley callus cultures at the gene expression, hormone composition and freezing tolerance levels in the presence or absence of Dicamba, the exogenous auxin analogue used in tissue cultivation. Our results suggest the presence of a basal, cold-responsive activation mechanism of CBF and COR genes with the highest influence on the evolvement of frost resistance, which is independent of the differentiated state of cells or chloroplast-related, light-induced and systemic signals. However, these factors seem to be required for reaching the maximum level of activation. The exogenous auxin analogue, Dicamba, seems to be rather a coinducer in this process, since it does not affect the initiation or the characteristic of the activation, only influences the magnitude of the response

Classifying GRB 170817A/GW170817 in a Fermi duration–hardness plane

GRB 170817A, associated with the LIGO-Virgo GW170817 neutron-star merger event, lacks the short duration and hard spectrum of a Short gamma-ray burst (GRB) expected from long-standing classification models. Correctly identifying the class to which this burst belongs requires comparison with other GRBs detected by the Fermi GBM. The aim of our analysis is to classify Fermi GRBs and to test whether or not GRB 170817A belongs—as suggested—to the Short GRB class. The Fermi GBM catalog provides a large database with many measured variables that can be used to explore gamma-ray burst classification. We use statistical techniques to look for clustering in a sample of 1298 gamma-ray bursts described by duration and spectral hardness. Classification of the detected bursts shows that GRB 170817A most likely belongs to the Intermediate, rather than the Short GRB class. We discuss this result in light of theoretical neutron-star merger models and existing GRB classification schemes. It appears that GRB classification schemes may not yet be linked to appropriate theoretical models, and that theoretical models may not yet adequately account for known GRB class properties. We conclude that GRB 170817A may not fit into a simple phenomenological classification scheme. © 2018, Springer Science+Business Media B.V., part of Springer Nature

Cannabidiol exerts sebostatic and antiinflammatory effects on human sebocytes.

The endocannabinoid system (ECS) regulates multiple physiological processes, including cutaneous cell growth and differentiation. Here, we explored the effects of the major nonpsychotropic phytocannabinoid of Cannabis sativa, (-)-cannabidiol (CBD), on human sebaceous gland function and determined that CBD behaves as a highly effective sebostatic agent. Administration of CBD to cultured human sebocytes and human skin organ culture inhibited the lipogenic actions of various compounds, including arachidonic acid and a combination of linoleic acid and testosterone, and suppressed sebocyte proliferation via the activation of transient receptor potential vanilloid-4 (TRPV4) ion channels. Activation of TRPV4 interfered with the prolipogenic ERK1/2 MAPK pathway and resulted in the downregulation of nuclear receptor interacting protein-1 (NRIP1), which influences glucose and lipid metabolism, thereby inhibiting sebocyte lipogenesis. CBD also exerted complex antiinflammatory actions that were coupled to A2a adenosine receptor-dependent upregulation of tribbles homolog 3 (TRIB3) and inhibition of the NF-kappaB signaling. Collectively, our findings suggest that, due to the combined lipostatic, antiproliferative, and antiinflammatory effects, CBD has potential as a promising therapeutic agent for the treatment of acne vulgaris

A novel control of human keratin expression: cannabinoid receptor 1-mediated signaling down-regulates the expression of keratins K6 and K16 in human keratinocytes in vitro and in situ

Cannabinoid receptors (CB) are expressed throughout human skin epithelium. CB1 activation inhibits human hair growth and decreases proliferation of epidermal keratinocytes. Since psoriasis is a chronic hyperproliferative, inflammatory skin disease, it is conceivable that the therapeutic modulation of CB signaling, which can inhibit both proliferation and inflammation, could win a place in future psoriasis management. Given that psoriasis is characterized by up-regulation of keratins K6 and K16, we have investigated whether CB1 stimulation modulates their expression in human epidermis. Treatment of organ-cultured human skin with the CB1-specific agonist, arachidonoyl-chloro-ethanolamide (ACEA), decreased K6 and K16 staining intensity in situ. At the gene and protein levels, ACEA also decreased K6 expression of cultured HaCaT keratinocytes, which show some similarities to psoriatic keratinocytes. These effects were partly antagonized by the CB1-specific antagonist, AM251. While CB1-mediated signaling also significantly inhibited human epidermal keratinocyte proliferation in situ, as shown by K6/Ki-67-double immunofluorescence, the inhibitory effect of ACEA on K6 expression in situ was independent of its anti-proliferative effect. Given recent appreciation of the role of K6 as a functionally important protein that regulates epithelial wound healing in mice, it is conceivable that the novel CB1-mediated regulation of keratin 6/16 revealed here also is relevant to wound healing. Taken together, our results suggest that cannabinoids and their receptors constitute a novel, clinically relevant control element of human K6 and K16 expression

Statistical properties of Fermi GBM GRBs' spectra

Statistical studies of gamma-ray burst (GRB) spectra may result in important information on the physics of GRBs. The Fermi GBM catalog contains GRB parameters (peak energy, spectral indices, intensity) estimated fitting the gamma-ray SED of the total emission (fluence, flnc), and during the time of the peak flux pflx. Using contingency tables we studied the relationship of the models best fitting pflx and flnc time intervals. Our analysis revealed an ordering of the spectra into a power law - Comptonized - smoothly broken power law - Band series. This result was further supported by a correspondence analysis (CA) of the pflx and flnc spectra categorical variables. We performed a linear discriminant analysis (LDA) to find a relationship between categorical (spectral) and model independent physical data. LDA resulted in highly significant physical differences among the spectral types, that is more pronounced in the case of the pflx spectra, than for the flnc spectra. We interpreted this difference as caused by the temporal variation of the spectrum during the outburst. This spectral variability is confirmed by the differences in the low energy spectral index and peak energy, between the pflx and flnc spectra. We found that the synchrotron radiation is significant in GBM spectra. The mean low energy spectral index is close to the canonical value of {\alpha} = -2/3 during the peak flux. However, $\alpha$ is ~ -0.9 for the spectra of the fluences. We interpret this difference as showing that the effect of cooling is important only for the fluence spectra.Comment: Manuscript accepted for publication in MNRA

Triangle percolation in mean field random graphs -- with PDE

We apply a PDE-based method to deduce the critical time and the size of the giant component of the ``triangle percolation'' on the Erd\H{o}s-R\'enyi random graph process investigated by Palla, Der\'enyi and VicsekComment: Summary of the changes made: We have changed a remark about k-clique percolation in the first paragraph. Two new paragraphs are inserted after equation (4.4) with two applications of the equation. We have changed the names of some variables in our formula

Analysis of circulating extracellular vesicle-associated microRNAs in cortisol-producing adrenocortical tumors

PURPOSE: Circulating microRNAs (miRNA) have been described in patients with adrenocortical tumors, but the expression of miRNAs in non-functioning and cortisol-producing tumors has not been yet compared. Therefore, the objective of this study was to evaluate the expression of plasma extracellular vesicle (EV)-associated microRNAs in patients with non-functioning adrenocortical adenoma (NFA), cortisol-producing adrenocortical adenoma (CPA) and cortisol-producing adrenocortical carcinoma (CP-ACC). METHODS: Preoperative plasma EV samples of 13 NFAs, 13 CPAs and 9 CP-ACCs were subjected to extracellular vesicle isolation. miRNAs were investigated by targeted quantitative real-time PCR normalized to cel-miR-39 as reference. Five miRNAs have been selected for this analysis based on the previous studies including hsa-miR-22-3p, hsa-miR-27a-3p, hsa-miR-210-3p, hsa-miR-320b and hsa-miR-375. RESULTS: We have observed significant overrepresentation of three miRNAs in both CPA and CP-ACC relative to NFA: hsa-miR-22-3p (p < 0.01 and p < 0.0001, respectively), hsa-miR-27a-3p (p < 0.05 in both comparisons) and hsa-miR-320b (p < 0.05 and p < 0.0001, respectively). Hsa-miR-320b has been significantly overrepresented in CP-ACC relative to CPA (p < 0.01). Hsa-miR-210-3p turned out to be significantly overrepresented only in CP-ACC compared to NFA (p < 0.05). Significant correlation was revealed between circulating miRNA concentrations and urinary free cortisol values for hsa-miR-22-3p, hsa-miR-27a-3p and hsa-miR-320b (p < 0.0001 for all) and cortisol after low-dose dexamethasone test for hsa-miR-22-3p and hsa-miR-320b (p < 0.05). Hsa-miR-27a-3p has been significantly stimulated by low-dose dexamethasone test (p < 0.05). CONCLUSIONS: EV-associated miRNAs are differentially expressed in different non-functioning and cortisol-producing adrenocortical tumors