The Impact of Stealthy Attacks on Smart Grid Performance: Tradeoffs and Implications

The smart grid is envisioned to significantly enhance the efficiency of energy consumption, by utilizing two-way communication channels between consumers and operators. For example, operators can opportunistically leverage the delay tolerance of energy demands in order to balance the energy load over time, and hence, reduce the total operational cost. This opportunity, however, comes with security threats, as the grid becomes more vulnerable to cyber-attacks. In this paper, we study the impact of such malicious cyber-attacks on the energy efficiency of the grid in a simplified setup. More precisely, we consider a simple model where the energy demands of the smart grid consumers are intercepted and altered by an active attacker before they arrive at the operator, who is equipped with limited intrusion detection capabilities. We formulate the resulting optimization problems faced by the operator and the attacker and propose several scheduling and attack strategies for both parties. Interestingly, our results show that, as opposed to facilitating cost reduction in the smart grid, increasing the delay tolerance of the energy demands potentially allows the attacker to force increased costs on the system. This highlights the need for carefully constructed and robust intrusion detection mechanisms at the operator.Comment: Technical report - this work was accepted to IEEE Transactions on Control of Network Systems, 2016. arXiv admin note: substantial text overlap with arXiv:1209.176

The sleep-inducing lipid oleamide deconvolutes gap junction communication and calcium wave transmission in glial cells.

Oleamide is a sleep-inducing lipid originally isolated from the cerebrospinal fluid of sleep-deprived cats. Oleamide was found to potently and selectively inactivate gap junction-mediated communication between rat glial cells. In contrast, oleamide had no effect on mechanically stimulated calcium wave transmission in this same cell type. Other chemical compounds traditionally used as inhibitors of gap junctional communication, like heptanol and 18beta-glycyrrhetinic acid, blocked not only gap junctional communication but also intercellular calcium signaling. Given the central role for intercellular small molecule and electrical signaling in central nervous system function, oleamide- induced inactivation of glial cell gap junction channels may serve to regulate communication between brain cells, and in doing so, may influence higher order neuronal events like sleep induction

Theological Comments mentioned in Jâmi’al- Tirmdzî and Its Application in Achieving Acceptance and Understanding within Muslim Community

This is a study of the theological comments of Imam Tirmidzi and those of which he mentioned in his book “al-Jâmi’ al-Kabîr”. These comments provide us a picture of how the early generations of Islam dealt with the issues related to Creed and Aqêda, Furthermore the issue of scarcity of views and comments associated to the early generations of Islam in dealing the issues of Creed and Aqêda is also dealt with in this study. Most of the comments of at-Tirmidzi in the study are mentioned as exact quotations and then they are classified according to the topics they are related to, and after classification analysis of the content along with the methodology and inclination of the holder of the opinion regarding these issues of Aqêda is studied. The study shows that the issue which overwhelmed and kept the early generation of Islam occupied was the issue of amal (Actions) related to those issues of creed or in other words they were more interested in the actions which has to exist as a result of that aqeedah hence those whose thoughts and emotions are attached to these early generations of Islam have to follow them in their pursuit of actions more than any other thing. Moreover regarding the conception of anthropomorphistic attributes the study yields that the more accurate and sound opinion associated to the early generations in this regard in the opinion of Tafwêdhi.e to depute the knowledge of its meaning to God alone and that on extremely rare occasions they use to incline towards their taweel i.e metaphorical interpretation. And this last issue in particular must and should be discussed within scholarly circles only and the general public should refrain from indulging themselves in such technical issues

Argumentation Through the Concept of Qadar as Depicted in Qurân

This paper revolves around those verses of Quran in which Quran states the argument of the non-believers provide for the justification of their disbelief and acts of polytheism and that is the argument of Qadar. The argument follows that the non-believers are not to be blamed for their disbelieve because these acts are been decreed by God for them. The paper emphasises upon a detail analysis of their argument and upon the quranic response to them by exposing their flawed argumentation and wrong claim. The paper then studies and establishes the position of belief in qadar and it’s position and place within the Islamic belief system, and furthermore studies those different issues which are discussed and dealt within those Quranic verses related to qadar. Moreover the interpretations of those Quranic verses which states this claim of non- believers according to different Mufassirin are studied and analysed and then in the end a general Quranic view regarding how Quran deals with the issue of “ärgumentation based upon the concept of Qadar” is presented in the paper

JUHŪD AL-ASYĀ’IRAH AL-MUĀSRĪN FĪ AL-TAQRĪB BAYN AL-AFKĀR AL-SUNNIYYAH: AL-SYAIKH HASAN AL-SYĀFI’Ī NAMŪŻAJAN

The article aims to describe Hasan al-Shafi’i’s view of uniting Sunnis theologically as an applied model. Through historical-philosophical analysis, this article found that Hasan al-Shafi’i viewed the need to unite Sunni viewpoints in the contemporary era. With his background in communication with the Islamic world and the West, Hasan al-Shafi’i confirmed the importance of understanding I’tidāl from al-Asy’ari theology. This theology rests on the spirit of harmony and tolerance, assuming that diversity is fairness and that plural life is the foundation of life that must be maintained. This view implies the restoration of theological relations between Sunni groups. Such a converged approach can serve as a model that is methodologically expected to enhance rapprochement on and off the Sunni spectru

Central extracorporeal membrane oxygenation as a bridge to recovery in patients with myocardial stunning after coronary artery bypass grafting

Background: The role of central extracorporeal membrane oxygenation (ECMO) post coronary artery bypass grafting (CABG) in older patients is debatable. The objectives of our study were to investigate the role of central veno-arterial (V-A) ECMO as a bridge to recovery in patients with myocardial stunning after CABG and its effect on mortality in this group of patients. Methods: Seventy-five patients had central ECMO as a bridge to recovery  after CABG because of myocardial stunning; 45 of them (60%) had survived (group 1), and mortality occurred in 30 patients (40%) (group 2). Preoperative risk factors such as hypertension, stroke, and renal failure were comparable between groups. In non-survivors, left main disease was more common (19 (63.3%) vs. 13 (28.9%); p= 0.003) and SYNTAX score was higher (Median 33 (25th- 75th percentiles); 33 (29- 35) vs. 26 (25- 32); p< 0.001). Results: Cross-clamp time was shorter in group 1 (58 minutes; (52-62) vs 115.5 minutes; (84- 161) in group 2; p< 0.001). Cardiopulmonary bypass time was shorter in group 1 compared to group 2 (83; (70-90) vs. 155.5; (60 -120) minutes; p< 0.001). ECMO duration was longer in group 2 (6 days; (6-7) vs. 3 days; (3-4); p<0.001). Stroke occurred in 10 patients (33.33%) in group 2 vs. 1 patient (2.22%) in groups 1; p< 0.001. Longer cross-clamp (OR: 1.61, 95% CI: 1.11- 2.31, p= 0.011) and bypass time (OR: 1.76; 95% CI: 1.57- 1.99; p= 0.048) predicted postoperative mortality. Conclusion: Central ven-arterial extramembrane oxygenation can be used as a bridge to recovery in patients with stunned myocardium post coronary bypass grafting, especially in centers where heart transplantation and ventricular assist devices are not available

Hypothermic circulatory arrest with or without antegrade cerebral perfusion for aortic arch surgery in infants

Background: Antegrade cerebral perfusion (ACP) minimizes deep hypothermic circulatory arrest (DHCA) duration during arch surgery in infants, which may impact the outcomes of the repair. We aimed to evaluate the effect of adding antegrade cerebral perfusion to deep hypothermic circulatory arrest on DHCA duration and operative outcomes of different aortic arch operations in infants. Methods: We retrospectively collected data from infants (<20 weeks old) who underwent aortic arch reconstruction (Norwood operation, arch reconstruction for the hypoplastic arch and interrupted aortic arch) using DHCA alone (n=88) or combined with ACP (n=26). We excluded patients who had concomitant procedures and those with preoperative neurological disability. Results: There was no difference between groups as regards the age, gender, and the operation performed (p= 0.64; 0.87 and 0.50; respectively). Among the 114 patients, 11 (9.6%) had operative mortality, and 14 (12.3%) had cerebral infarction diagnosed with CT scanning. Adding ACP to DHCA significantly reduced DHCA duration from 50.7 ± 10.6 minutes to 22.4 ± 6.2 minutes (p<0.001) and lowered the mortality (11 vs. 0; p=0.066) and cerebral infarction (13 vs. 1; p=0.18). No statistically significant difference between the two groups in terms of ischemic time (p=0.63) or hospital stay duration (p=0.47). Conclusion: Using ACP appears to reduce the DHCA duration and was associated with better survival and neurological outcomes of aortic arch surgery in infants. A study with longer follow-up to evaluate the long-term neurological sequelae is recommended

Self-scheduling of wind-thermal systems using a stochastic MILP approach

In this work a stochastic (Stoc) mixed-integer linear programming (MILP) approach for the coordinated trading of a price-taker thermal (Ther) and wind power (WP) producer taking part in a day-ahead market (DAM) electricity market (EMar) is presented. Uncertainty (Uncer) on electricity price (EPr) and WP is considered through established scenarios. Thermal units (TU) are modelled by variable costs, start-up (ST-UP) technical operating constraints and costs, such as: forbidden operating zones, minimum (Min) up/down time limits and ramp up/down limits. The goal is to obtain the optimal bidding strategy (OBS) and the maximization of profit (MPro). The wind-Ther coordinated configuration (CoConf) is modelled and compared with the unCoConf. The CoConf and unCoConf are compared and relevant conclusions are drawn from a case study

Mitral valve repair for myxomatous mitral regurgitation; Respect or Resect

Background: The superiority of mitral repair using resection of the posterior leaflet versus neo-artificial chordea is still debatable. The objective of this study was to compare leaflet resection versus chordal replacement for mitral valve repair in patients with isolated myxomatous degeneration of the posterior mitral valve leaflet.   Methods: This study was conducted on 199 patients with severe symptomatic mitral regurgitation due to myxomatous mitral valve degeneration. Patients were grouped into two groups: Group (1): Respect technique which included  76 patients who had limited resection of the anterior leaflet, chordal transfer, and replacement of anterior leaflet chordae by polytetrafluoroethylene sutures, and placement of annuloplasty ring. Group (2): Resect technique included  123 patients where the operation was done by resecting the prolapsed mid scallop of the posterior leaflet and placement of flexible annuloplasty ring. Results: There was no difference between both groups regarding gender. Patients in the Respect group were younger (37 (25th- 75th percentiles: 29- 44) vs. 54 (48- 60) years, P<0.001). The minimally invasive approach was more commonly used in patients who had resection techniques (20 (26.32%) vs. 106 (86.18%); P<0.001). Ischemic (99 (95- 106) vs. 79 (75- 82); P<0.001) and cardiopulmonary bypass times (134.5 (130- 138.5) vs. 99 (97- 104) min; P<0.001) were higher in the Respect group. Blood loss was more in the Resect group (370 (305- 390) vs. 550 (490- 600) ml; P<0.001). There were no differences in the postoperative complications between groups. ICU stay was longer in patients in the Resect group (5 (5- 6) vs. 7 (6- 8) days; P<0.001). Mitral valve gradient after 12 months was significantly higher in the Resect group (3 (3- 3.5) vs. 4 (3- 5) mmHg; P<0.001). Mitral valve reoperation was required more in patients in the Respect group (5 (6.58%) vs. 1 (0.81%); P= 0.03). Conclusions: Both Respect and resect techniques for mitral valve repair had comparable outcomes and durability. The repair technique should be tailored according to the mitral valve pathology

Comparison of automated fastener (Cor-Knot) versus manually tied knots in patients undergoing minimally invasive mitral valve replacement

Introduction: Automated knot fastener has been used in minimally invasive valve surgery to alleviate the longer total operating time and improve outcomes. Their advantages over manual knot tying remain questionable. This study aims to compare automated knot fasteners' efficacy with conventional knot-pushers in minimally invasive mitral valve replacements (MiMVR). Methods: Between 2016 and 2020, 50 patients underwent isolated mechanical mitral valve replacement via right mini-thoracotomy in rheumatic or degenerative mitral valve disease. The patients were grouped into two groups. Group I (n= 25) included patients who had MiMVR using the Cor-knot device, and Group II (n= 25) had MiMVR using the conventional knot-pusher. Primary endpoints were cross-clamp, cardiopulmonary bypass, and total operative times and the secondary outcomes were paravalvular leak and reoperation. There were no significant differences in the demographic data between the two groups. Results: Cross-clamp time (79± 1.11 vs. 98.88± 1.34 min; P<0.001), cardiopulmonary bypass time ( 132 (Q1- Q2: 129- 134) vs. 148 (140- 155) min; P<0.001) and operative times ( 206 (203- 209) vs. 228 (223- 234) min; P<0.001) were significantly shorter in Group I. There was no difference in postoperative complications between groups. The early paravalvular leak occurred in one patient (4%) in Group I and required valve re-exploration. In Group II, four patients (16%) had a paravalvular leak; 3 of them were severe and required valve re-exploration (P= 0.35). Transthoracic echocardiography at discharge revealed no evidence of a paravalvular leak in both groups. Conclusion: Automated fastener device (Cor-knot) could reduce operative times during minimally invasive mitral valve replacement. Operative complications are comparable between both techniques, and follow-up studies are recommended