Oncologic outcomes following surgical management of clinical stage II sex cord stromal tumors

Objective To investigate the clinical history of patients with clinical stage II sex cord stromal tumors who underwent RPLND at our institution. Methods Our prospectively maintained testicular cancer database was queried to identify patients who presented with or developed clinical stage II sex cord stromal tumors and underwent RPLND at our institution between 1980 and 2018. Demographic, clinical and pathological characteristics were reviewed. Kaplan-Meier curves were graphed to assess recurrence-free and overall survival. Results Fourteen patients were included in the study with a median age of 44.2 years. Four patients presented with clinical stage II disease and 10 patients developed metastatic disease during follow-up of initial clinical stage I disease with a median time to metastasis of 2.7 years (range: 0.4-19.5 years). Of the 10 patients with orchiectomy pathology data available, all patients had at least 1 risk factor on testis pathology (mean: 2.9 risk factors). Nine patients received treatment prior to referral to our institution. All patients recurred post-RPLND at Indiana University. Median recurrence-free survival was 9.8 months. Twelve patients died of disease with a median overall survival of 14.4 months. Conclusions Metastatic sex cord stromal tumors are rare and are more resistant to standard treatment modalities than metastatic germ cell tumors. Patients presenting with sex cord stromal tumors should consider prophylactic primary RPLND in the setting of one or more pathological predictor of malignancy

`Hidden' Symmetries of Higher Dimensional Rotating Black Holes

We demonstrate that the rotating black holes in an arbitrary number of dimensions and without any restrictions on their rotation parameters possess the same `hidden' symmetry as the 4-dimensional Kerr metric. Namely, besides the spacetime symmetries generated by the Killing vectors they also admit the (antisymmetric) Killing-Yano and symmetric Killing tensors.Comment: 4 pages, slightly extended introductio

Electronic stress tensor analysis of hydrogenated palladium clusters

We study the chemical bonds of small palladium clusters Pd_n (n=2-9) saturated by hydrogen atoms using electronic stress tensor. Our calculation includes bond orders which are recently proposed based on the stress tensor. It is shown that our bond orders can classify the different types of chemical bonds in those clusters. In particular, we discuss Pd-H bonds associated with the H atoms with high coordination numbers and the difference of H-H bonds in the different Pd clusters from viewpoint of the electronic stress tensor. The notion of "pseudo-spindle structure" is proposed as the region between two atoms where the largest eigenvalue of the electronic stress tensor is negative and corresponding eigenvectors forming a pattern which connects them.Comment: 22 pages, 13 figures, published online, Theoretical Chemistry Account

Gravitational Slingshot of Young Massive Stars in Orion

The Orion Nebula Cluster (ONC) is the nearest region of massive star formation and thus a crucial testing ground for theoretical models. Of particular interest amongst the ONC's ~1000 members are: \theta^1 Ori C, the most massive binary in the cluster with stars of masses 38 and 9 MSun (Kraus et al. 2009); the Becklin-Neugebauer (BN) object, a 30 km/s runaway star of ~8 MSun (Tan 2004); and the Kleinmann-Low (KL) nebula protostar, a highly-obscured, ~15 MSun object still accreting gas while also driving a powerful, apparently "explosive" outflow (Allen & Burton 1993). The unusual behavior of BN and KL is much debated: How did BN acquire its high velocity? How is this related to massive star formation in the KL nebula? Here we report the results of a systematic survey using ~ 10^7 numerical experiments of gravitational interactions of the \theta^1C and BN stars. We show that dynamical ejection of BN from this triple system at its observed velocity leaves behind a binary with total energy and eccentricity matching those observed for \theta^1C. Five other observed properties of \theta^C are also consistent with it having ejected BN and altogether we estimate there is only a <~ 10^{-5} probability that \theta^1C has these properties by chance. We conclude that BN was dynamically ejected from the \theta^1C system about 4,500 years ago. BN has then plowed through the KL massive-star-forming core within the last 1,000 years causing its recently-enhanced accretion and outflow activity.Comment: 16 pages, 9 figures, 1 table, accepted to Ap

Hidden Symmetry of Higher Dimensional Kerr-NUT-AdS Spacetimes

It is well known that 4-dimensional Kerr-NUT-AdS spacetime possesses the hidden symmetry associated with the Killing-Yano tensor. This tensor is "universal" in the sense that there exist coordinates where it does not depend on any of the free parameters of the metric. Recently the general higher dimensional Kerr-NUT-AdS solutions of the Einstein equations were obtained. We demonstrate that all these metrics with arbitrary rotation and NUT parameters admit a universal Killing-Yano tensor. We give an explicit presentation of the Killing-Yano and Killing tensors and briefly discuss their properties.Comment: 4 pages, some discussion and references are adde

Model for SU(3) vacuum degeneracy using light-cone coordinates

Working in light-cone coordinates, we study the zero-modes and the vacuum in a 2+1 dimensional SU(3) gauge model. Considering the fields as independent of the tranverse variables, we dimensionally reduce this model to 1+1 dimensions. After introducing an appropriate su(3) basis and gauge conditions, we extract an adjoint field from the model. Quantization of this adjoint field and field equations lead to two constrained and two dynamical zero-modes. We link the dynamical zero-modes to the vacuum by writing down a Schrodinger equation and prove the non-degeneracy of the SU(3) vacuum provided that we neglect the contribution of constrained zero-modes.Comment: 22 pages, 5 figure