Negative Mass Solitons in Gravity

We first reconstruct the conserved (Abbott-Deser) charges in the spin connection formalism of gravity for asymptotically (Anti)-de Sitter spaces, and then compute the masses of the AdS soliton and the recently found Eguchi-Hanson solitons in generic odd dimensions, unlike the previous result obtained for only five dimensions. These solutions have negative masses compared to the global AdS or AdS/Z_p spacetimes. As a separate note, we also compute the masses of the recent even dimensional Taub-NUT-Reissner-Nordstrom metrics.Comment: 12 pages, RevTEX4; typos fixed; v3: version to appear in PRD, references adde

Gravitational charges of transverse asymptotically AdS spacetimes

Using Killing-Yano symmetries, we construct conserved charges of spacetimes that asymptotically approach to the flat or Anti-de Sitter spaces only in certain directions. In D dimensions, this allows one to define gravitational charges (such as mass and angular momenta densities) of p-dimensional branes/solitons or any other extended objects that curve the transverse space into an asymptotically flat or AdS one. Our construction answers the question of what kind of charges the antisymmetric Killing-Yano tensors lead to.Comment: 11 pages, no figures, REVTeX 4; version 2: important corrections made; version 3: one new paragraph and 2 references added, accepted for publication in PR

A note on the pp-wave solution of Minimal Massive 3D Gravity coupled with Maxwell-Chern-Simons theory

In this work, we examine a family of $pp$-wave solutions of Minimal Massive 3d Gravity (MMG) minimally coupled with the Maxwell-Chern-Simons theory. An elaborate investigation of the field equations shows that the theory admits $pp$-wave solutions provided that there exist an anti-self duality relation between the electric and the magnetic components of the Maxwell 2-form field. By employing Noether-Wald formalism, we also construct Noether charges of the theory within exterior algebra formalism.Comment: v2 : improved versio

Finite mass gravitating Yang monopoles

We show that gravity cures the infrared divergence of the Yang monopole when a proper definition of conserved quantities in curved backgrounds is used, i.e. the gravitating Yang monopole in cosmological Einstein theory has a finite mass in generic even dimensions (including time). In addition, we find exact Yang-monopole type solutions in the cosmological Einstein-Gauss-Bonnet-Yang-Mills theory and briefly discuss their properties

Cochlear implantation in inner ear malformations: Considerations related to surgical complications and communication skills

Introduction: There are particular challenges in the implantation of malformed cochleae, such as in cases of facial nerve anomalies, cerebrospinal fluid (CSF) leaks, erroneous electrode insertion, or facial stimulation, and the outcomes may differ depending on the severity of the malformation. The aim of this study was to assess the impact of inner ear malformations (IEMs) on surgical complications and outcomes of cochlear implantation. Methods: In order to assess the impact of IEMs on cochlear implant (CI) outcomes, 2 groups of patients with similar epidemiological parameters were selected from among 863 patients. Both the study group (patients with an IEM) and control group (patients with a normal inner ear) included 25 patients who received a CI and completed at least 1 year of follow-up. Auditory performance, receptive and expressive language skills, and production and use of speech were evaluated preoperatively and at least 1 year after implantation. Types of surgical complications and rates of revision surgeries were determined in each group. Results: In the study group, the most common malformation was an isolated enlarged vestibular aqueduct (EVA) (44.8%). Overall, the patients with IEMs showed significant improvement in auditory-verbal skills. In general, the patients who had normal cochleae scored significantly better compared to patients with IEMs (p < 0.05). The complication rate was significantly lower in the control group compared to the study group (p = 0.001), but the rate of revision surgeries did not differ significantly (p = 0.637). Conclusion: It is possible to improve communication skills with CIs in patients with IEMs despite the variations in postoperative performances. Patients with EVA, incomplete partition type 2, and cochlear hypoplasia type 2 were the best performers in terms of auditory-verbal skills. Patients with IEMs scored poorly compared to patients with normal cochleae. CSF leak (gusher or oozing) was the most common complication during surgery, which is highly likely in cases of incomplete partition type 3

Clinical Characteristics and Visual Outcomes of Pediatric Optic Neuritis: A Single Center Experience

INTRODUCTION: The aim of this study was to describe the clinical characteristics, visual outcomes of pediatric patients presenting with first-episode of optic neuritis. METHODS: We reviewed medical records of the patients newly diagnosed with optic neuritis younger than 18 years between January 2014 and December 2018 retrospectively. RESULTS: Twenty-eight patients were included to this study. The mean age at first onset of optic neuritis was 13.2+-3.1 years (range 6.2-17.3 years). The mean follow-up period was 4.2+-3.2 (range 0.6-13.08) years. 7 of 28 (25%) patients had recurrent optic neuritis. Optic neuritis involvement was unilateral in 17 of 28 (60%) patients. Forty percent of the patients had idiopathic optic neuritis. Of the six patients with demyelinating lesions in cranial magnetic resonance imaging (MRI) at the first admission, three were diagnosed with multiple sclerosis (MS) at the time of first optic neuritis attack, and three were diagnosed within 13.4+-4.8 months after the first episode. Eight of 21 optic neuritis patients (38%) had oligoclonal band positivity and the incidence of MS was significantly higher in these patients (p=0.014). The mean visual acuity at nadir was 0.48+-0.27 at admission. Whereas it was 0.74+-0.31 and 0.76+-0.33 at 1 and 6 months respectively. There was a strong correlation between first and sixth-month visual acuity (r=0.98, p=0.00). DISCUSSION AND CONCLUSION: Our study demonstrated that poor visual acuity (worse than 0.5) at 1 month can predict poor vision at 6 months. The patients with demyelinating lesions in cranial MRI at their first optic neuritis episode, are more likely to develop MS during the follow-up

Spinal cerebrospinal fluid leakage in spontaneous intracranial hypotension: An intrathecal gadolinium enhanced MR-myelography study

Objectives: In the present study, the authors presented the intrathecal gadolinium enhanced MR-myelography findings of patients with spontaneous intracranial hypotension. Materials and Methods: Intrathecal gadolinium enhanced MR-myelography (Gd-MR-myelography) examina-tions between October 2012 and September 2018 in patients having clinical and radiological findings of spontaneous intracranial hypotension were evaluated retrospectively. Sites and types of contrast leakages in 20 patients who met inclusion criteria were reviewed. All patients had undergone T1-fat suppressed sagittal images of cervical, thoracic and lumbar region after the off label intrathecal injection of 1 ml gadolinium-based contrast agent. Results: Patients (18 female, 2 male) are aged between 23 and 62 years-old (mean age: 41.1). Cerebrospi-nal fluid (CSF) leakages were cervical in 6 patients, thoracic in 5 patients, lumbar in 5 patients. One patient had leakage in multiple levels on both cervical and thoracic region and another patient on both cervical-thoracic and lumbar regions. No patients had adverse effects related to intrathecal injection of gadolinium. Conclusions: Gd-MR-myelography is effective imaging modality to reveal spinal CSF leakages in patients with spontaneous intracranial hypotension