Detailed studies of IPHAS sources - I. The disrupted late bipolar IPHASX J193718.6+202102

We present a detailed analysis of the new planetary nebula (PN) IPHASX J193718.6+202102 using deep imaging and intermediate- and high resolution spectroscopy that are interpreted through morpho-kinematic and photoionisation modelling. The physical structure of the nebula consists of a fragmented torus and an extremely faint orthogonal bipolar outflow, contrary to the pinched waist PN morphology suggested by its optical image. Our kinematic analysis indicates that the torus is expanding at 25±5 km s−1 and is gradually breaking up. At an estimated distance of 7.1$_{-0.3}^{+0.8}$ kpc, the corresponding kinematic age of ∼26000 years is consistent with a faint and disintegrating PN. The intermediate-resolution spectra reveal an excited PN with chemical abundances typical of Type II PNe. Based on the latter we also estimate an initial mass for the progenitor in the range 2–3 M⊙ and a central star (CSPN) mass MCSPN ∼0.61 M⊙. The Spitzer MIPS 24 μm emission that closely follows the fragmented torus could be attributed to the emission of [O iv] at 25.9 μm rather than to dust emission. All the results coherently point towards an evolved moderately massive bipolar Type II PN on the brink of dissolving into the interstellar medium.

Regional Specialization of Pyramidal Neuron Morphology and Physiology in the Tree Shrew Neocortex

The mammalian cerebral cortex is divided into different areas according to their function and pattern of connections. Studies comparing primary visual (V1) and prefrontal cortex (PFC) of primates have demonstrated striking pyramidal neuron (PN) specialization not present in comparable areas of the mouse neocortex. To better understand PFC evolution and regional PN specialization, we studied the tree shrew, a species with a close phylogenetic relationship to primates. We defined the tree shrew PFC based on cytoarchitectonic borders, thalamic connectivity and characterized the morphology and electrophysiology of layer II/III PNs in V1 and PFC. Similar to primates, the PFC PNs in the tree shrew fire with a regular spiking pattern and have larger dendritic tree and spines than those in V1. However, V1 PNs showed strikingly large basal dendritic arbors with high spine density, firing at higher rates and in a more varied pattern than PFC PNs. Yet, unlike in the mouse and unreported in the primate, medial prefrontal PN are more easily recruited than either the dorsolateral or V1 neurons. This specialization of PN morphology and physiology is likely to be a significant factor in the evolution of cortex, contributing to differences in the computational capacities of individual cortical areas.

Comparison of Time Lapse Embryo Morphokinetics Monitoring and Conventional Pronuclear Morphology Assessment to Determine Embryo Quality in Endometriosis Patients

<p><strong>Objective</strong></p><p>Endometriosis patients who underwent IVF program has poorer embryo quality, leads to low successive rate. In order to determine embryo quality, time lapse embryo monitoring and pronuclear (PN) morphology assessment were used to predict and select the most promising embryo. This research is expected to exhibit comparison the use of both methods in endometriosis patients in order to implement the most effective evaluation in future embryo implantation prognosis.</p><p><strong>Methods</strong></p><p>This cohort research was conducted to 72 embryos from 19 endometriosis patients who underwent IVF program in Yasmin Reproductive Clinic, Cipto Mangunkusumo Hospital. After ICSI was performed two-nucleated embryo later be monitored by its cleavage time and would be classified into categories for good quality embryo and other classes were considered poor quality embryo for time lapse monitoring. Then from time lapse monitoring, PN morphology were assessed regarding pronuclear scoring.</p><p><strong>Results</strong></p><p>Based on 72 embryos observation, we found that there was no significant difference between good and poor quality embryo based on PN scoring with p=0.185, and also between time-lapse morphokinetic monitoring and embryo quality with p=0.526. However, we found that there was a weak correlation between PN scoring and embryo quality with p=0.049 and r=0.233.</p><p><strong>Conclusion</strong></p><p>There was no significant difference found between time lapse monitoring and PN scoring in endometriosis patients in order to determine embryo quality. However, there was a weak correlation between PN scoring and embryo quality. This might be due to small number of samples taken and visual bias during observation.</p>

Shape, structure, and morphology in planetary nebulae

A revival over the past two decades in planetary nebula (PN) morphological studies springs from a combination of factors, including the advent of wide-area, high dynamic range detectors; the growing archives of high resolution images from the X-ray to the sub-mm; and the advent of sophisticated models of the co-evolution of PNe and their central stars. Yet the story of PN formation from their immediate precursors, the AGB stars, is not yet fully written. PN morphology continues to inspire, provide context for physical interpretation, and serve as an ultimate standard of comparison for many investigations in this area of astrophysics. After a brief review of the remarkable successes of PN morphology, I summarize how this tool has been employed over the last half-decade to advance our understanding of PNe.

Hubble Space TelescopeUltraviolet Spectroscopy of Central Stars of the LMC Planetary Nebulae

In the quest to understand the origin of Planetary Nebula (PN) morphology, correlations have been sought between the nebular shapes and the evolutionary status of the central stars. Several of the mechanisms proposed to explain asymmetric shapes have a direct link with the central star's evolutionary status. Among the possible mechanisms invoked to produce asymmetric PNs, stellar rotation is certainly an effective one, as several hydrodynamics models have shown. In this work we present Space Telescope Imaging Spectrograph (STIS) UV spectra of a sample of bright LMC PNs and their central stars. LMC PNs distances are known, thus the observed characteristics of the stars translate into absolute physical quantities readily, and provide the safest dataset for theory-observation comparisons. We are planing to fit stellar models to the observed spectra using black-body SEDs and synthetic photometry to estimate stellar temperature and reddening. We are going to use the stellar evolutionary tracks to compare the post-AGB age with the dynamical age from the nebula. P-Cygni profiles will be analyzed in order to determine an approximation of the mass loss rate. Stellar characteristics will be related to the morphology of the nebulae observed by our group with HST STIS optical slitless spectroscopy.

The Correlation of PN Morphology and Parameters

The morphology of a complete sample of 255 northern planetary nebulae (PNe) was studied and correlated with the nebular parameters. PNe were classified according to the following scheme: round (R, 25%), elliptical (E, 58% of the sample), and bipolar (B, 17%). Bipolars include the quadrupolar subsample. A subclass of pointsymmetric and multiple shell PNe was also found. Nine per cent of ellipticals and 46% of bipolars were found to be pointsymmetric. Thirty-five per cent of the round and 22% of the elliptical PNe were found to be multiple shell PNe (MSPNe). Galactic latitude was found to be different for each morphological class (|b| = 8°, 5° and 2° for types R, E, and B, respectively). Galactic height was also found to vary: 〈z〉 = 647, 276, and 100 pc for categories R, E, and B, respectively. Segregation according to the chemical abundances was also found, with helium abundances of 0.10, 0.12, and 0.14 and N/O of 0.21, 0.31, and 1.33 for types R, E, and B, respectively. Both galactic distribution and chemical abundances point to a different stellar population for each morphological class, the round and bipolar types being the result of low and high stellar mass progenitor evolution, respectively.