J. Kelemen

Over-expression of dopamine D2 receptor and inwardly rectifying potassium channel genes in drug-naive schizophrenic peripheral blood lymphocytes as potential diagnostic markers

Schizophrenia is one of the most common neuropsychiatric disorders affecting nearly 1% of the human population. Current diagnosis of schizophrenia is based on complex clinical symptoms. The use of easily detectable peripheral molecular markers could substantially help the diagnosis of psychiatric disorders. Recent studies showed that peripheral blood lymphocytes (PBL) express subtypes of D1 and D2 subclasses of dopamine receptors. Recently, dopamine receptor D3 (DRD3) was found to be over-expressed in schizophrenic PBL and proposed to be a diagnostic and follow-up marker for schizophrenia. In this study we screened PBL of 13 drug-naive/drug-free schizophrenic patients to identify additional markers of schizophrenia. One of the benefits of our study is the use of blood samples of non-medicated, drug-naive patients. This excludes the possibility that changes detected in gene expression levels might be attributed to the medication rather than to the disorder itself. Among others, genes for dopamine receptor D2 (DRD2) and the inwardly rectifying potassium channel (Kir2.3) were found to be over-expressed in microarray analysis. Increased mRNA levels were confirmed by quantitative real-time PCR (QRT-PCR) using the SybrGreen method and dual labeled TaqMan probes. The use of both molecular markers allows a more rapid and precise prediction of schizophrenia and might help find the optimal medication for schizophrenic patients.

The outburst and nature of two young eruptive stars in the North America/Pelican Nebula Complex

Context. In August 2010, the sudden optical brightening of two young stellar objects, HBC 722 and VSX J205126.1+440523, located in the North America/Pelican Nebula Complex, was announced. Early photometric and spectroscopic observations of these objects indicated that they may belong to the FUor or EXor class of young eruptive stars. The eruptions of FUors and EXors are often ex- plained by enhanced accretion of material from the circumstellar disk to the protostar. Aims. In order to determine the true nature of these two objects, we started an optical and near-infrared monitoring program, a nd complemented our data with archival observations and data from the literature. Methods. We plot and analyze pre-outburst and outburst spectral energy distributions (SEDs), multi-filter light curves, and col or-color diagrams. Results. The quiescent SED of HBC 722 is consistent with that of a slightly reddened normal T Tauri-type star. The source bright- ened monotonically in about two months, and the SED obtained during maximum brightness indicates the appearance of a hot, single-temperature blackbody. The current fading rate implies that the star will return to quiescence in about a year, q uestioning its classification as a bone fide FUor. The quiescent SED of VSX J20 5126.1+440523 looks like that of a highly embedded Class I source. The outburst of this source happened more gradually, but reached an unprecedentedly high amplitude. At 2.5 months after the peak, its light curves show a deep minimum, when the object was close to its pre-outburst optical brightness. Further monitori ng indicates that it is still far from being quiescent. Conclusions. The shape of the light curves, as well as the bolometric luminosities and accretion rates suggest that these objects do no t fit into the classic FUor group. Although HBC 722 exhibit all s pectral characteristics of a bona fide FUor, its luminosity a nd accretion rate is too low, and its timescale is too fast compared to clas sical FUors. VSX J205126.1+440523 seems to be an example where quick extinction changes modulate the light curve.

Improved distance determination to M 51 from supernovae 2011dh and 2005cs

Aims. The appearance of two recent supernovae, SN 2011dh and 2005cs, both in M 51, provides an opportunity to derive an improved distance to their host galaxy by combining the observations of both SNe. Methods. We apply the Expanding Photosphere Method to get the distance to M 51 by fitting the data of these two SNe simultaneously. In order to correct for the effect of flux dilution, we use correction factors (ζ) appropriate for standard type II-P SNe atmospheres for 2005cs, but find ζ ∼ 1 for the type IIb SN 2011dh, which may be due to the reduced H-content of its ejecta. Results. The EPM analysis resulted in D M5 1 = 8.4 ± 0.7 Mpc. Based on this improved distance, we also re-analyze the HST observations of the proposed progenitor of SN 2011dh. We confirm that the object detected on the pre-explosion HST-images is unlikely to be a compact stellar cluster. In addition, its derived radius (∼277 R� ) is too large for being the real (exploded) progenitor of SN 2011dh. Conclusions. The supernova-based distance, D = 8.4 Mpc, is in good agreement with other recent distance estimates to M 51.

EXTENSIVE SPECTROSCOPY and PHOTOMETRY of the TYPE IIP SUPERNOVA 2013ej

We present extensive optical (UBV RI, {g} \prime {r} \prime {i} \prime {z} \prime , and open CCD) and near-infrared (ZY JH) photometry for the very nearby Type IIP SN 2013ej extending from +1 to +461 days after shock breakout, estimated to be MJD 56496.9 ± 0.3. Substantial time series ultraviolet and optical spectroscopy obtained from +8 to +135 days are also presented. Considering well-observed SNe IIP from the literature, we derive UBV RIJHK bolometric calibrations from UBV RI and unfiltered measurements that potentially reach 2% precision with a B ‑ V color-dependent correction. We observe moderately strong Si ii λ 6355 as early as +8 days. The photospheric velocity ({v} {{ph }}) is determined by modeling the spectra in the vicinity of Fe ii λ 5169 whenever observed, and interpolating at photometric epochs based on a semianalytic method. This gives {v} {{ph }}=4500+/- 500 km s ‑1 at +50 days. We also observe spectral homogeneity of ultraviolet spectra at +10–12 days for SNe IIP, while variations are evident a week after explosion. Using the expanding photosphere method, from combined analysis of SN 2013ej and SN 2002ap, we estimate the distance to the host galaxy to be {9.0} -0.6 +0.4 Mpc, consistent with distance estimates from other methods. Photometric and spectroscopic analysis during the plateau phase, which we estimated to be 94 ± 7 days long, yields an explosion energy of 0.9+/- 0.3× {10} 51 erg, a final pre-explosion progenitor mass of 15.2 ± 4.2 {M} ȯ and a radius of 250 ± 70 {R} ȯ . We observe a broken exponential profile beyond +120 days, with a break point at +183 ± 16 days. Measurements beyond this break time yield a 56 Ni mass of 0.013 ± 0.001 M {} ȯ .

Exploring the circumstellar environment of the young eruptive star V2492 Cygni

Context. V2492 Cyg is a young eruptive star that went into outburst in 2010. The near-infrared color changes observed since the outburst peak suggest that the source belongs to a newly defined sub-class of young eruptive stars, where time-dependent accretion and variable line-of-sight extinction play a combined role in the flux changes. Aims. In order to learn about the origin of the light variations and to explore the circumstellar and interstellar environment of V2492 Cyg, we monitored the source at ten different wavelengths, between 0.55 μm and 2.2 μm from the ground and between 3.6 μm and 160 μm from space. Methods. We analyze the light curves and study the color−color diagrams via comparison with the standard reddening path. We examine the structure of the molecular cloud hosting V2492 Cyg by computing temperature and optical depth maps from the far-infrared data. Results. We find that the shapes of the light curves at different wavelengths are strictly self-similar and that the observed variability is related to a single physical process, most likely variable extinction. We suggest that the central source is episodically occulted by a dense dust cloud in the inner disk and, based on the invariability of the far-infrared fluxes, we propose that it is a long-lived rather than a transient structure. In some respects, V2492 Cyg can be regarded as a young, embedded analog of UX Orionis-type stars. Conclusions. The example of V2492 Cyg demonstrates that the light variations of young eruptive stars are not exclusively related to changing accretion. The variability provided information on an azimuthally asymmetric structural element in the inner disk. Such an asymmetric density distribution in the terrestrial zone may also have consequences for the initial conditions of planet formation.

OVERTONE AND MULTI-MODE RR LYRAE STARS IN THE GLOBULAR CLUSTER M3

The overtone and multi-mode RR Lyrae stars in the globular cluster M3 are studied using a 200 day long, B,V, and {I}{{C}} time-series photometry obtained in 2012. 70% of the 52 overtone variables observed show some kind of multi-periodicity (with additional frequency at {f}0.61={f}1{{O}}/0.61 frequency ratio, Blazhko effect, double/multi-mode pulsation, and period doubling). A signal at the 0.587 frequency ratio to the fundamental-mode frequency is detected in the double-mode star, V13, which may be identified as the second radial overtone mode. If this mode identification is correct, than V13 is the first RR Lyrae star showing triple-mode pulsation of the first three radial modes. Either the Blazhko effect or the {f}0.61 frequency (or both of these phenomena) appears in seven double-mode stars. The {P}1{{O}}/{P}{{F}} period ratio of RRd stars showing the Blazhko effect are anomalous. A displacement of the main frequency component at the fundamental mode with the value of modulation frequency (or its half), is detected in three Blazhko RRd stars that are parallel with the appearance of the overtone-mode pulsation. The {f}0.61 frequency appears in RRc stars that lie at the blue side of the double-mode region and in RRd stars, raising the suspicion that its occurrence may be connected to double-mode pulsation. The changes of the Blazhko and double-mode properties of the stars are also reviewed using the recent and archive photometric data.

Gene and protein expression changes in response to normoxic perfusion in mouse hearts

INTRODUCTION Although crystalloid-perfused isolated heart models are widely used in cardiovascular research, there are several limitations of these techniques. Changes in cardiac gene expression pattern due to normoxic perfusion itself have not been studied, despite its potential importance to provide useful information on limitations of this model. Therefore, here we investigated the time-dependent effect of normoxic, normothermic perfusion on global gene expression at mRNA and protein levels. METHODS Hearts from male CFLP mice were perfused according to the Langendorff technique. We assessed relative gene expression changes by DNA microarray analysis of 8000 genes after 0, 60 and 120 min perfusion. RESULTS Twelve genes exhibited significant up-regulation and 27 showed repression in hearts perfused for 60 or 120 min as compared to 0 min controls. Expression changes of 17 selected genes were verified and an additional 19 genes were examined by real-time quantitative PCR. Genes with altered expression included those coding for Creatin kinase, Lactate dehydrogenase, Voltage-dependent anion channel 1, a Disintegrin and Metalloprotease domain 3, Integrin alpha 7, Long-chain acyl-CoA dehydrogenase, Casein kinase II, Ketohexokinase, Chloride ion current inducer protein, Matrix metalloproteinase 2 and 9, Superoxide dismutases and Nitric oxide synthases, etc. DISCUSSION Our results show that normoxic crystalloid perfusion itself results in time-dependent changes in cardiac gene expression which should be considered when designing ex vivo perfusion protocols in the mouse heart to mimic cardiac pathologies as many of these genes have been suspected to influence several cardiovascular diseases.

Star count analysis of the interstellar matter in the region of L1251

We studied the ISM distribution in and around the star forming cloud L1251 with optical star counts. A careful calculation with a maximum likelihood based statistical approach resulted in B, V, R, I extinction distributions from the star count maps. A distance of 330 ± 30 pc was derived. The extinction maps revealed an elongated dense cloud with a bow shock at its eastern side. We estimated a Mach number of M ≈ 2 for the bow shock. A variation of the apparent dust properties is detected, i.e. the RV = AV /EB−V total to selective extinction ratio varies from 3 to 5.5, peaking at the densest part of L1251. The spatial structure of the head of L1251 is well modelled with a Schuster-sphere (i.e. n = 5 polytropic sphere). The observed radial distribution of mass fits the model with high accuracy out to 2.5 pc distance from the assumed center. Unexpectedly, the distribution of NH3 1.3 cm line widths is also well matched by the Schuster solution even in the tail of the cloud. Since the elongated head-tail structure of L1251 is far from the spherical symmetry the good fit of the linewidths in the tail makes it reasonable to assume that the present cloud structure has been formed by isothermal contraction.

The early phases of the type Iax supernova SN 2011ay

We present a detailed study of the early phases of the peculiar supernova 2011ay based on BVRI photometry obtained at Konkoly Observatory, Hungary, and optical spectra taken with the Hobby-Eberly Telescope at McDonald Observatory, Texas. The spectral analysis carried out with SYN++ and SYNAPPS confirms that SN 2011ay belongs to the recently defined class of SNe Iax, which is also supported by the properties of its light and color curves. The estimated photospheric temperature around maximum light, T_{phot} ~8,000 K, is lower than in most Type Ia SNe, which results in the appearance of strong Fe II features in the spectra of SN 2011ay, even during the early phases. We also show that strong blending with metal features (those of Ti II, Fe II, Co II) makes the direct analysis of the broad spectral features very difficult, and this may be true for all SNe Iax. We find two alternative spectrum models that both describe the observed spectra adequately, but their photospheric velocities differ by at least 3,000 km/s. The quasi-bolometric light curve of SN~2011ay has been assembled by integrating the UV-optical spectral energy distributions. Fitting a modified Arnett-model to L_{bol}(t), the moment of explosion and other physical parameters, i.e. the rise time to maximum, the ^{56}Ni mass and the total ejecta mass are estimated as t_{rise} ~14 +/-1 days, M_{Ni} ~0.22 +/- 0.01 M_{sol} and M_{ej} ~0.8 M_{sol}, respectively.

The Continuing Story of SN IIb 2013df: New Optical and IR Observations and Analysis

This work has been supported by the Hungarian Scientific Research Fund (OTKA) Grants NN107637, K104607, K83790, and K113117. TS is supported by the OTKA Postdoctoral Fellowship PD112325. JCW’s Supernova group at the UT Austin is supported by NSF Grant AST 11-09881 grant. JMS is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-1302771. KS and AP are supported by the ‘Lend¨ulet-2009’ Young Researchers Program and the LP2012-31 grant of the Hungarian Academy of Sciences, respectively; KS is also supported by the ESA PECS Contract no. 4000110889/14/NL/NDe.