Nonlocal black hole evaporation and quantum metric fluctuations via inhomogeneous vacuum density

Inhomogeneity of the actual value of the vacuum energy density is considered in a black hole background. We examine the back-reaction of a Schwarzschild black hole to the highly inhomogeneous vacuum density, and argue the fluctuations lead to deviations from general relativity in the near-horizon region. In particular, we found that vacuum fluctuations onto the horizon trigger adiabatic release of quantum information, while vacuum fluctuations in the vicinity of the horizon produce potentially observable metric fluctuations of order the Schwarzschild radius. Consequently, we propose a form of strong nonviolent nonlocality in which we simultaneously get nonlocal release of quantum information, and observable metric fluctuations.Comment: 10 pages, REVTeX 4.1, 2 figures. Published in the Special Issue "Classical and Quantum Approaches to Black Holes" of Advances in High Energy Physic

Entropic Entanglement: Information Prison Break

We argue certain nonviolent local quantum field theory (LQFT) modification considered at the global horizon ($r=2M$) of a static spherically-symmetric black hole can lead to adiabatic leakage of quantum information in the form of Hawking particles. The source of the modification is (i) smooth at $r=2M$ and (ii) rapidly vanishing at $r\gg2M$. Furthermore, we restore the unitary evolution by introducing extra quanta which departs slightly from the generic Hawking emission without changing the experience of an infalling observer (no drama). Also, we suggest that a possible interpretation of the Bekenstein-Hawking bound as entanglement entropy may yield a nonsingular dynamical horizon behavior described by black hole thermodynamics. Hence by treating gravity as a field theory, and considering its coupling to the matter fields in the Minkowski vacuum, we derive the conjectured fluctuations of the background geometry of a black hole.Comment: 16 pages, 2 figures. Published in Advances in High Energy Physic

School Principals – Educational Leaders And Professional Managers

The article studies the current changes in the functions and vision of the heads of educational institutions. The main management styles are analyzed. The professional and personal qualities modern school principals need to combine in order to successfully manage schools are outlined. The specifics and characteristics of school principals as professional managers and educational leaders are clarified. Specific emphasis is placed on managing governance processes, the status and position of school principals in the management hierarchy

Non-Financial Factors In Managing The Relationships Principal – Teachers

This article discusses the main psychological regularities of communication as an interpersonal interaction and the personal qualities of the principal and the teacher as elements of the psychological climate appearing to be an environment for non-financial stimulation of productivity at the school as a budget administrator. Pedagogical interaction is viewed as a professional communication and behavioral aspect of the relationships between the school principal and the pedagogical specialists as well as among the teachers themselves as members of the pedagogical staff. For this purpose, we have clarified the specific terms and aspects of pedagogical ethics, the tolerance and communication at school as non-financial factors in managing the relationships principal – teachers. We have determined their characteristics and the means of achieving the ethical objective. Special emphasis is placed on the competence of the school principal – a leader and manager – and the efficient interaction with all pedagogical specialists (deputy principals; primary, middle and secondary school teachers; tutors; pedagogical counsellors; resource teachers; psychologists)

Unique stability of femoral neck fractures treated with the novel biplane double-supported screw fixation method: A biomechanical cadaver study

AbstractOsteosynthesis of femoral neck fractures is related to 20–46% complication rate. Filipov's novel method for biplane double-supported screw fixation (BDSF), using three cannulated screws, has demonstrated excellent clinical results since 2007. Its two calcar-buttressed screws are oriented in different coronal inclinations with steeper angles to the diaphyseal axis and intended to provide constant fixation strength under different loading situations.The aim of this study was to biomechanically evaluate BDSF fixation strength and compare it with the conventional fixation (CFIX) using three parallel cannulated screws.MethodsEight fresh-frozen and six embalmed human femoral pairs with simulated AO/OTA31–B2.2 fracture were fixed applying either CFIX or BDSF. Quasistatic tests were performed in anteroposterior (AP) bending, followed by axial quasistatic, cyclic and destructive quasistatic tests run in 10° flexion with 7° or 16° varus specimen inclination.ResultsInitial axial stiffness was significantly higher for BDSF in comparison with CFIX at 7° inclination (p=0.02) and not significantly different between BDSF and CFIX at 16° inclination. Compared with the intact state, it decreased significantly at 7° inclination only for CFIX (p=0.01), but not for BDSF. Interfragmentary displacement during cyclic testing was significantly smaller for BDSF than CFIX at 7° inclination (p≤0.04) and not significantly different between BDSF and CFIX at 16° inclination. Failure load did not differ significantly between BDSF and CFIX at both inclinations.ConclusionsFemoral neck fracture stability can be substantially increased applying BDSF due to better cortical screw support and screw orientation. Having two calcar-buttressed screws oriented in different inclinations, BDSF can enhance constant stability during various patient activities. The more unstable the situation, the better BDSF stability is in comparison to CFIX

Laparoscopic Total Mesorectal Excision After 450 Cases

INTRODUCTION: The laparoscopic technique is widely adopted in the surgical treatment of colorectal carcinoma. Thus, patients benefit from the usual short-term advantages of minimally invasive surgery over classical open surgery, with comparable long-term oncological results.AIM: The study presents the experience of the Clinic for General and Endoscopic Surgery of St. Ivan Rilski University Hospital in Sofia, with laparoscopic radical rectal resections for rectal carcinoma over a 14-year period and more than 450 completed laparoscopic interventions.MATERIALS AND METHODS: From January 2009 until December 2022, 454 laparoscopic curative rectal resections for rectal carcinoma were performed. Only patients with cT1–cT3 tumors, without distant metastases, were included in the study.RESULTS: The studied group included 301 (66.3%) men and 153 (33.7%) women, aged between 34 and 86 years, with an average BMI of 26 kg/m2 (21–32 kg/m2). According to the localization of the tumor in the rectum, the patients were divided as follows: proximal 1/3 (10–15 cm)—148 (32.6%); middle 1/3 (5 < 10 cm)—203(44.7%), and distal 1/3(< 5 cm)—103 (22.7%). A total of 277 (61%) patients underwent neoadjuvant chemoradiation. Eighty-five (18.7%) of the operated were in the 1st stage, 159 (35%)—in the 2nd stage, 219 (46.3%)—in the 3rd stage. Conversion was necessary in 23 cases (5.1%). The average duration of the operative intervention was 180 minutes. (120–420 min), and the blood loss was 80 mL (20–800 mL). Intestinal passage was restored on average on the 2nd postoperative day (1–7 days). The average postoperative hospital stay was 5 days (3–17 days). Complications occurred in 35 patients (7.7%). The operated patients were followed up for an average of 36 months (3–60). The overall recurrence rate was 15.6%.CONCLUSION: Laparoscopic rectal resections for carcinoma are safe interventions, characterized by less postoperative pain, less blood loss, faster bowel recovery, shorter hospital stay, and excellent cosmetic results with comparable to open surgery oncological outcomes