Optimization problems under two-sided (max; min)–linear Inequalities constraints

as well as numerical examples will be presented

Surgical versus optical treatment for anisometropia in adults: A randomized controlled trial

Background: We evaluated and compared outcomes of laser-assisted in situ keratomileusis (LASIK) versus optical spectacle correction for the treatment of anisometropia in adult patients. Methods: This prospective, randomized controlled clinical trial included 50 eyes of 50 patients. We randomly allocated participants to Group A (25 eyes with anisometropia assigned to LASIK treatment) and Group B (25 eyes with anisometropia assigned to optical spectacle correction). All patients underwent preoperative and postoperative visual acuity, subjective and cycloplegic refraction, fundus, slit-lamp, and corneal topography examinations. Results: In Group A, at 1-month postoperatively, there were statistically significant differences in uncorrected distance visual acuity, corrected distance visual acuity, refractive sphere, cylinder, and spherical equivalent (SE) as compared to baseline. At 3-months postoperatively in Group A, SE showed good stability within ± 0.50 diopter (D) in 22 eyes (88%) and within ± 0.75 D in 23 eyes (92%), while two eyes had an SE beyond 1.00 D emmetropia. Five eyes had amblyopia with minimal improvement in two eyes in Group A after LASIK, and no improvement in three eyes treated with spectacles in Group B. Two amblyopic eyes had developed ocular deviations by the end of the study that referred to the strabismus unit. Conclusions: Our outcomes revealed that LASIK was more effective and advantageous than spectacles in the treatment of different types of anisometropia in adults. However, future randomized trials should focus on optical versus surgical treatment of anisometropia and anisometropic amblyopia in both pediatric and adult patients, to verify these conclusions before generalizing this treatment modality

Prevalence of Cytomegalovirus infection among Egyptian patients with fever of unknown origin

Background: Diagnosis of prolonged febrile illness of unknown origin (FUO) is challenging even with the advances in the diagnostic techniques. As common as the infection with cytomegalovirus (CMV) is, most health care providers would not suspect CMV infection as a cause of FUO unless mononucleosis syndrome is evident. The aim of this study is to investigate the rate of CMV infection among patients with FUO and shed light on IgG avidity as a diagnostic tool.  Patients and methods: Two hundred and twenty three (223) immune competent patients with FUO were included in our study. They were subjected to all routine laboratory investigations, fever agglutinins, tuberculin and abdominal ultrasound along with IgG and IgM for CMV and IgG avidity test. Results:  This study shows that the 92.8% of the overall studied population were positive for CMV IgG. However, only 74(33.2%) of the studied population was found positive for IgM. Only one patient had positive IgM with negative IgG. IgG avidity was high in almost all of them. Only 3 patients showed low IgG avidity denoting that they have primary infection. Conclusion: CMV infection was found to be the cause of 33.2% of prolonged febrile illness experienced by immuncompetent adults. Only 1.8% of patients had primary CMV infection and the majority of them had detectable IgG level and were diagnosed with primary infection depending mainly on IgG avidity test

Optimalizační problémy při (max,min.)-lineárních omezeních a některé související úlohy

Title: Optimization Problems under (max, min)-Linear Constraints and Some Related Topics. Author: Mahmoud Gad Department/Institue: Department of Probability and Mathematical Statis- tics Supervisor of the doctoral thesis: 1. Prof. RNDr. Karel Zimmermann,DrSc 2. Prof. Dr. Assem Tharwat, Cairo University, Egypt Abstract: Problems on algebraic structures, in which pairs of operations such as (max, +) or (max, min) replace addition and multiplication of the classical linear algebra have appeared in the literature approximately since the sixties of the last century. The first publications on these algebraic structures ap- peared by Shimbel [37] who applied these ideas to communication networks, Cunninghame-Green [12, 13], Vorobjov [40] and Gidffer [18] applied these alge- braic structures to problems of machine-time scheduling. A systematic theory of such algebraic structures was published probable for the first time in [14]. In recently appeared book [4] the readers can find latest results concerning theory and algorithms for (max, +)-linear systems of equations and inequalities. Since operation max replacing addition in no more a group, but a semigroup oppera- tion, it is a substantial difference between solving systems with variables on one side and systems with variables occuring on both sides of the equations....Název práce: Optimalizační problémy při (max,min)-lineárních omezeních a některé související úlohy. Author: Mahmoud Gad Katedra/Ústav: Katedra Pravděpodobnosti a matematické statistiky Vedoucí dizertační práce: 1. Prof. RNDr. Karel Zimmermann, DrSc 2. Prof. Dr. Assem Tharwat, Cairo University Egypt . Abstrakt: Úlohy na algebraických strukturách, v nichž dvojice operací (max, +) nebo (max, min) nahrazují operace sčítání a násobení v klasické lineární algebře se objevují v literatuře přibližně od šedesátých let minulého století. První výsledky s využitím těchto struktur publikovali A. Shimbel v práci [37] s aplikacemi v komunikačních sítích, a dále R. A. Cunnighame-Green [12,13], N. Vorobjov [40] a B. Giffler [18] s aplikacemi na rozvrhování práce strojů a v teorii spolehlivosti. Ucelená systematická teorie takových algebraických struktur byla publikována pravděpodobně poprvé v práci [14]. V nedávno publikované knize [4] lze nalézt nejnovější stav výzkumu teorie a algoritmů ve struktuře s operacemi (max,+). Protože operace maxima, která v uvedených strukturách nahrazuje operaci sčítání, není grupovou, ale pouze pologrupovou operací, je podstatný rozdíl mezi řešením soustav s proměnnými pouze na jedné straně rovnic resp. nerovností a soustav, v nichž se proměnné nacházejí na obou stranách těchto vztahů....Katedra pravděpodobnosti a matematické statistikyDepartment of Probability and Mathematical StatisticsFaculty of Mathematics and PhysicsMatematicko-fyzikální fakult

Multi-Finishing of Polyester and Polyester Cotton Blend Fabrics Activated by Enzymatic Treatment and Loaded with Zinc Oxide Nanoparticles

The present work discusses the possibility of applying enzymatic treatments for fabric surface activation that can facilitate the loading of zinc oxide nanoparticles (ZnO NPs) onto polyester (PET) and polyester cotton blend (PET/C) fabrics prepared by sol-gel method. Activated polyester fabrics loaded by ZnO NPs were investigated by the use of scanning electron microscopy (SEM), electron dispersion emission X-ray (EDX) and Fourier transformed infrared spectroscopy (FT-IR). The functionality of activated polyester fabrics loaded by ZnO NPs was evaluated by analyzing its antimicrobial activity and UV protection efficiency. Antimicrobial activity of activated polyester fabrics and loaded by ZnO NPs was tested against Gram-positive (Bacillus mycoides), Gram-negative (Escherichia coli), and nonfilamentous fungus (Candida albicans). The level of UV protection was verified by the UV protection factor (UPF) of polyester fabrics. Activated post-treated polyester fabrics exhibited outstanding antimicrobial and UV protection efficiency. The achieved antimicrobial function and UV protection on the polyester fabrics are durable with repeated laundering processes even after five washing cycles

Examining the modes malware suppliers use to provide goods and services

Malware suppliers use various modes to provide goods and services to customers. By mode, we mean “the way” the malware supplier chooses to function. These modes increase monetization opportunities and enable many security breaches worldwide. A theoretically sound framework that can be used to examine the various modes that malware suppliers use to produce and sell malware is needed. We apply a general model specified recently by Hagiu and Wright to study five modes that malware suppliers use to deliver goods and services to their customers. The framework presented in this article can be used to predict the mode in which a malware supplier will function; to study which types of malware suppliers, agents, and customers are attracted to each mode; to discover new modes; and to better understand the threat a malware supplier presents

Essays on Corporate Disclosure of Value Creation

Information on a firm’s business model helps investors understand an entity’s resource requirements, priorities for action, and prospects (FASB, 2001, pp. 14-15; IASB, 2010, p. 12). Disclosures of strategy and business model (SBM) are therefore considered a central element of effective annual report commentary (Guillaume, 2018; IIRC, 2011). By applying natural language processing techniques, I explore what SBM disclosures look like when management are pressed to say something, analyse determinants of cross-sectional variation in SBM reporting properties, and assess whether and how managers respond to regulatory interventions seeking to promote SBM annual report commentary. This dissertation contains three main chapters. Chapter 2 presents a systematic review of the academic literature on non-financial reporting and the emerging literature on SBM reporting. Here, I also introduce my institutional setting. Chapter 3 and Chapter 4 form the empirical sections of this thesis. In Chapter 3, I construct the first large sample corpus of SBM annual report commentary and provide the first systematic analysis of the properties of such disclosures. My topic modelling analysis rejects the hypothesis that such disclosure is merely padding; instead finding themes align with popular strategy frameworks and management tailor the mix of SBM topics to reflect their unique approach to value creation. However, SBM commentary is less specific, less precise about time horizon (short- and long-term), and less balanced (more positive) in tone relative to general management commentary. My findings suggest symbolic compliance and legitimisation characterize the typical annual report discussion of SBM. Further analysis identifies proprietary cost considerations and obfuscation incentives as key determinants of symbolic reporting. In Chapter 4, I seek evidence on how managers respond to regulatory mandates by adapting the properties of disclosure and investigate whether the form of the mandate matters. Using a differences-in-differences research design, my results suggest a modest incremental response by treatment firms to the introduction of a comply or explain provision to provide disclosure on strategy and business model. In contrast, I find a substantial response to enacting the same requirements in law. My analysis provides clear and consistent evidence that treatment firms incrementally increase the volume of SBM disclosure, improve coverage across a broad range of topics as well as providing commentary with greater focus on the long term. My results point to substantial changes in SBM reporting properties following regulatory mandates, but the form of the mandate does matter. Overall, this dissertation contributes to the accounting literature by examining how firms discuss a central topic to economic decision making in annual reports and how firms respond to different forms of disclosure mandate. Furthermore, the results of my analysis are likely to be of value for regulators and policymakers currently reviewing or considering mandating disclosure requirements. By examining how companies adapt their reporting to different types of regulations, this study provides an empirical basis for recalibrating SBM disclosure mandates, thereby enhancing the information set of capital market participants and promoting stakeholder engagement in a landscape increasingly shaped by non-financial information

Clinical and angiographic outcomes with drug-coated balloons for de novo coronary lesions: A meta-analysis of randomized clinical trials

Background The role of drug-coated balloons (DCBs) in the treatment of de novo coronary lesions is not well established. Methods and Results Electronic databases and major conference proceedings were searched for randomized controlled trials that compared DCBs with stents or angioplasty for de novo coronary lesions. The primary outcome was target lesion revascularization. Summary estimates were conducted using random-effects analysis complemented by several subgroup and sensitivity analyses. A total of 14 randomized controlled trials with 2483 patients were included. At a mean follow up of 12 months, DCBs were associated with no difference in the incidence of target lesion revascularization as compared with alternative strategies (risk ratio [RR], 0.79; 95% CI, 0.35-1.76). There was no difference in treatment effect based on the indication (ie, small-vessel disease, myocardial infarction, bifurcation, or high bleeding risk) (Pinteraction=0.22). DCBs were associated with lower target lesion revascularization compared with bare metal stents and similar target lesion revascularization compared with drug-eluting stents (Pinteraction=0.03). There was no difference between DCBs and control in terms of major adverse cardiac events, vessel thrombosis, or cardiovascular mortality. However, DCBs were associated with a lower incidence of myocardial infarction (RR, 0.48; 95% CI, 0.25-0.90) and all-cause mortality (RR, 0.45; 95% CI, 0.22-0.94). Conclusions In patients with de novo coronary lesions, use of DCBs was associated with comparable clinical outcomes irrespective of the indication or comparator device. DCBs had a similar rate of target lesion revascularization compared with drug-eluting stents. A randomized trial powered for clinical outcomes and evaluating the role of DCBs for all-comers is warranted

Arthroscopic Assisted Reduction and Internal Fixation of Tibial Plateau Fractures

BACKGROUND: Tibial plateau fractures present an important entity in orthopaedic fractures. Arthroscopic-assisted reduction and internal fixation is a good alternative to ORIF as it has the advantage of direct visualisation of the articular surface of the plateau, direct assessment of the reduction of the articular surface, and managing any associated intra-articular pathology. AIM: Our study aim is to determine the results of arthroscopic assisted reduction and internal fixation of tibial plateau fractures. METHODS: This study involved 25 patients with tibial plateau fractures presenting to the emergency department of Cairo University Hospitals between the periods of November 2016 and May 2017. The patients were followed up for an average of 14 months (11-18 months). According to Schatzker’s classification, five patients had type I, eleven had type II, and nine patients had type III fractures. RESULTS: The average time to full union in Schatzker type I was 9.1 weeks, in type II was 10.2 weeks, and in type III it was 9.4. The mean clinical Rasmussen score among the 25 patients was 26 (range, 24-30). A group of 19 patients (76%) had excellent results, (4 type I, 8 types II, and 7 types III) 6 patients (24 %) had good results (1 type I, 3 types II, 2 types III). Radiologic results were excellent in (14 cases) 56.0% and good results (11 cases) 44%. CONCLUSION: Arthroscopic assisted reduction and fixation of tibial plateau fractures have the advantages of checking the adequacy of reduction, avoiding the need for detachment of the meniscus, and allowing for accurate diagnosis and management of associated knee injuries. Therefore, we recommend that arthroscopic assisted reduction and fixation of tibial plateau fractures should be used more often