In recent years, scholars have sought to investigate the impact that ethical leaders can have within organisations. Yet, only a few theoretical perspectives have been adopted to explain how ethical leaders influence subordinate outcomes. This study therefore draws on social rules theory (SRT) to extend our understanding of the mechanisms linking ethical leadership to employee attitudes. We argue that ethical leaders reduce disengagement, which in turn promotes higher levels of job satisfaction and organisational commitment, as well as lower turnover intentions. (...) Co-worker social undermining is examined as a moderator of the relationship between ethical leadership and disengagement, as we suggest that it is difficult for ethical leaders to be effective when co-worker undermining prevails. To test the proposed model, questionnaires were administered to 460 nurses in Romanian hospital settings over three time points separated by two-week intervals and the hypotheses were tested using generalised multilevel structural equation modeling (GSEM) with STATA. The findings revealed that ethical leadership has a beneficial effect on employee attitudes by reducing disengagement. However, the relationship between ethical leadership and disengagement was moderated by co-worker social undermining, such that when undermining was higher, the significance of the mediated relationships disappeared. These results suggest that while ethical leaders can promote positive employee attitudes, their effectiveness is reduced in situations where co-worker undermining exists. (shrink)

Drawing on social exchange theory, this study examines a mechanism, namely organizational social capital, through which self-sacrificial leadership is related to two types of employee behaviours: organizational citizenship behaviours and counterproductive behaviours. The results of two different studies in Egypt showed that self-sacrificial leadership is positively related to OSC which, in turn, is positively related to OCBs and negatively related to CPBs. Overall, the findings suggest that self-sacrificial leaders are more likely to achieve desirable employee behaviours through improving the quality (...) of social relationships among employees. (shrink)

The aim of this research is to explore the process linking participative leadership to organizational identification. The study examines the relationship between participative leadership and internal CSR perceptions of employees and also investigates the role that pride in membership plays in the affiliation of CSR perceptions with organizational identification. By studying these relationships, the paper aspires to contemplate new presumed mediators in the association of participative leadership with organizational identification as well as determine a possible novel antecedent of employee CSR (...) perceptions. Empirical evidence is provided from data that was collected through a survey distributed to employees working for small- and medium-sized enterprises in three countries in the Middle East and North Africa regions, particularly the United Arab Emirates, Lebanon, and Tunisia. Findings show that participative leadership leads to positive internal CSR perceptions of employees and that these CSR perceptions lead to pride in membership which, in turn, results in organizational identification. Implications of these findings are also discussed. (shrink)

We show that there exists an atomic polyadic equality algebra of dimension n that is elementary equivalent to a completely representable algebra, but its diagonal free reduct is not completely representable.

In this note we give an interpretation of cylindric algebras as algebras of sentences of first order logic. We show that the isomorphism types of such algebras of sentences coincide with the class of neat reducts of cylindric algebras. Also we show how this interpretation sheds light on some recent results. This is done by likening Henkin's Neat Embedding Theorem to his celebrated completeness proof.

With the rapid growth of informatics systems’ technology in this modern age, the Internet of Things (IoT) has become more valuable and vital to everyday life in many ways. IoT applications are now more popular than they used to be due to the availability of many gadgets that work as IoT enablers, including smartwatches, smartphones, security cameras, and smart sensors. However, the insecure nature of IoT devices has led to several difficulties, one of which is distributed denial-of-service (DDoS) attacks. IoT (...) systems have several security limitations due to their disreputability characteristics, like dynamic communication between IoT devices. The dynamic communications resulted from the limited resources of these devices, such as their data storage and processing units. Recently, many attempts have been made to develop intelligent models to protect IoT networks against DDoS attacks. The main ongoing research issue is developing a model capable of protecting the network from DDoS attacks that is sensitive to various classes of DDoS and can recognize legitimate traffic to avoid false alarms. Subsequently, this study proposes combining three deep learning algorithms, namely recurrent neural network (RNN), long short-term memory (LSTM)-RNN, and convolutional neural network (CNN), to build a bidirectional CNN-BiLSTM DDoS detection model. The RNN, CNN, LSTM, and CNN-BiLSTM are implemented and tested to determine the most effective model against DDoS attacks that can accurately detect and distinguish DDoS from legitimate traffic. The intrusion detection evaluation dataset (CICIDS2017) is used to provide more realistic detection. The CICIDS2017 dataset includes benign and up-to-date examples of typical attacks, closely matching real-world data of Packet Capture. The four models are tested and assessed using Confusion Metrix against four commonly used criteria: accuracy, precision, recall, and F-measure. The performance of the models is quite effective as they obtain an accuracy rate of around 99.00%, except for the CNN model, which achieves an accuracy of 98.82%. The CNN-BiLSTM achieves the best accuracy of 99.76% and precision of 98.90%. (shrink)

Floods are one of the most common natural disasters in the world that affect all aspects of life, including human beings, agriculture, industry, and education. Research for developing models of flood predictions has been ongoing for the past few years. These models are proposed and built-in proportion for risk reduction, policy proposition, loss of human lives, and property damages associated with floods. However, flood status prediction is a complex process and demands extensive analyses on the factors leading to the occurrence (...) of flooding. Consequently, this research proposes an Internet of Things-based flood status prediction (IoT-FSP) model that is used to facilitate the prediction of the rivers flood situation. The IoT-FSP model applies the Internet of Things architecture to facilitate the flood data acquisition process and three machine learning (ML) algorithms, which are Decision Tree (DT), Decision Jungle, and Random Forest, for the flood prediction process. The IoT-FSP model is implemented in MATLAB and Simulink as development platforms. The results show that the IoT-FSP model successfully performs the data acquisition and prediction tasks and achieves an average accuracy of 85.72% for the three-fold cross-validation results. The research finding shows that the DT scores the highest accuracy of 93.22%, precision of 92.85, and recall of 92.81 among the three ML algorithms. The ability of the ML algorithm to handle multivariate outputs of 13 different flood textual statuses provides the means of manifesting explainable artificial intelligence and enables the IoT-FSP model to act as an early warning and flood monitoring system. (shrink)

Population-based genomics studies have proven successful in identifying genetic variants associated with diseases. High-quality biospecimens linked with informative health data from diverse segments of the population have made such research possible. However, the success of biobank research depends on the willingness of the public to participate in this type of research. We aimed to explore the factors associated with the willingness of the public to participate in biobank research from four low- and middle-income countries in the Arab region (Egypt, Jordan, (...) Morocco, and Sudan). We used a previously validated questionnaire to assess several constructs that included the public’s perceptions, attitudes, and willingness to participate in biobank research. We recruited 967 participants. More than half did not have prior awareness of biobanks. Participants’ willingness to donate biospecimens and health data was less than 10%. Our results also showed that participants harbored concerns with trust, privacy, and with data-sharing involving international researchers. Predictors of willingness to participate in biobank research included no previous involvement in research and positive attitudes toward biobanks. Finally, our study showed several differences between the four countries regarding several of the investigated constructs. We conclude there should be additional efforts to raise public awareness and enhance perceptions of the public in biobanking research to enhance trust. We further recommend qualitative research to explore the underlying factors that contribute to the public’s concerns with international data sharing that would enhance global health. (shrink)

Business relations rely on shared perceptions of what is acceptable/expected norms of behavior. Immense expansion in transnational business made rudimentary consensus on acceptable business practices across cultural boundaries particularly important. Nonetheless, as more and more nations with different cultural and historical experiences interact in the global economy, the potential for misunderstandings based on different expectations is magnified. Such misunderstandings emerge in a growing literature on "improper" business practices – articulated from a narrow cultural perspective. This paper reports an ongoing research (...) on the cultural and contextual aspects of business ethics. The objective is to investigate how the perception/attitudes of business students towards the ethical dimension of doing business varies in different countries; Whether there are socio-cultural factors that influence the perception of ethicality in business practices. Research findings among business students in six countries: China, Egypt, Finland, Korea, Russia, and the U.S.A. are reported. While all groups had basic agreement on what constitutes ethical business practices, differences are found in the respondents'' tolerance to damage resulting from "unethical" behavior. Without underestimating the role of national culture, variations in research results also point to the importance of current socio-political developments in the relevant countries. Implications for business teaching and management development are discussed. (shrink)

We give a new characterization of the class of completely representable cylindric algebras of dimension 2 #lt; n ≤ w via special neat embeddings. We prove an independence result connecting cylindric algebra to Martin's axiom. Finally we apply our results to finite-variable first order logic showing that Henkin and Orey's omitting types theorem fails for Ln, the first order logic restricted to the first n variables when 2 #lt; n#lt;w. Ln has been recently (and quite extensively) studied as a many-dimensional (...) modal logic. (shrink)

PurposeThis study is justified by the economic importance of information on greenhouse gases, as well as the interest in the question of governance structure after the adoption of the objectives of the 2030 Agenda. The problem is also explained by the lack of research that has investigated the relationship between the best governance structure that contributes to achieving sustainability goals, including climate actions (SDG13) and clean energy adoption (SDG7) as part of the 2030 Agenda.Design/methodology/approachThe level of disclosure is measured on (...) the basis of the carbon disclosure score calculated by the carbon disclosure project (CDP). The study sample consists of 387 US companies that voluntarily participated in the CDP survey from 2011 to 2018. The authors use panel data analysis based on multiple regression models.FindingsThe results confirm the influential role of board size, director independence, the presence of women on the board and the presence of an environmental committee on carbon disclosure. In terms of carbon disclosure, the results suggest that a better governance structure is likely to reduce carbon emissions and improve carbon performance practices. Similarly, the analyses show a different representation of the role of corporate governance in high-carbon sectors compared to low-carbon sectors.Research limitations/implicationsThis study has some limitations. First, the sample is only interested in US companies that responded to the CDP questionnaire during the period 2011–2018. Thus, the results cannot be generalized to countries with different governance structures. Second, the data from this study on carbon disclosure, specifically focuses on CDP reporting to determine the carbon disclosure score. In this sense, the findings on information disclosed do not necessarily address disclosures through other media, such as a company’s website or a press release.Originality/valueSustainability and commitment to the sustainable development goals (SDGs) are more likely to exist in companies that have good governance and, in particular, a better board. The research is inspired by the SDGs. The study aims to examine the relationship between carbon disclosure and corporate governance in the context of SDGs. Indeed, this research work contributes to achieving sustainability goals, including climate actions (SDG13) and clean energy adoption (SDG7). (shrink)

SC , CA , QA and QEA stand for the classes of Pinter's substitution algebras, Tarski's cylindric algebras, Halmos' quasipolyadic algebras, and quasipolyadic equality algebras of dimension , respectively. Generalizing a result of Németi on cylindric algebras, we show that for K {SC, CA, QA, QEA} and ordinals , the class Nr K of -dimensional neat reducts of -dimensional K algebras, though closed under taking homomorphic images and products, is not closed under forming subalgebras (i.e. is not a variety) if (...) and only if > 1.From this it easily follows that for 1 , the operation of forming -neat reducts of algebras in K does not commute with forming subalgebras, a notion to be made precise. (shrink)

We give a new characterization of the class of completely representable cylindric algebras of dimension 2 #lt; n w via special neat embeddings. We prove an independence result connecting cylindric algebra to Martin''s axiom. Finally we apply our results to finite-variable first order logic showing that Henkin and Orey''s omitting types theorem fails for L n, the first order logic restricted to the first n variables when 2 #lt; n#lt;w. L n has been recently (and quite extensively) studied as a (...) many-dimensional modal logic. (shrink)

Let 1 n. We show that the class NrnCAβ of n-dimensional neat reducts of β-dimensional cylindric algebras is not closed under forming elementary subalgebras. This solves a long-standing open problem of Tarski and his co-authors Andréka, Henkin, Monk and Németi. The proof uses genuine model-theoretic arguments.

We show that not all epimorphisms are surjective in certain classes of infinite dimensional cylindric algebras, Pinter's substitution algebras and Halmos' quasipolyadic algebras with and without equality. It follows that these classes fail to have the strong amalgamation property. This answers a question in [3] and a question of Pigozzi in his landmark paper on amalgamation [9]. The cylindric case was first proved by Judit Madarasz [7]. The proof presented herein is substantially different. By a result of Németi, our result (...) implies that the Beth-definability Theorem fails for certain expansions of first order logic. (shrink)

In this paper, an extension of first order logic is introduced. In such logics atomic formulas may have infinite lengths. An Omitting Types Theorem is proved.

We show that it is impossible to define a substitution operator for arbitrary representable cylindric algebras that agrees in its basic properties with the notion of substitutions introduced for dimension complemented algebras.

We redefine a system of varieties definable by a schema of equations to include finite dimensions. Then we present a technique using ultraproducts enabling one to lift results proved for every finite dimension to the transfinite. Let \(\bf Ord\) denote the class of all ordinals. Let \(\langle \mathbf{K}_{\alpha}: \alpha\in \bf Ord\rangle\) be a system of varieties definable by a schema. Given any ordinal \(\alpha\), we define an operator \(\mathsf{Nr}_{\alpha}\) that acts on \(\mathbf{K}_{\beta}\) for any \(\beta>\alpha\) giving an algebra in \(\mathbf{K}_{\alpha}\), (...) as an abstaction of taking \(\alpha\)-neat reducts for cylindric algebras. We show that for any positive \(k\), and any infinite ordinal \(\alpha\) that \(\mathbf{S}\mathsf{Nr}_{\alpha}\mathbf{K}_{\alpha+k+1}\) cannot be axiomatized by a finite schema over \(\mathbf{S}\mathsf{Nr}_{\alpha}\mathbf{K}_{\alpha+k}\) given that the result is valid for all finite dimensions greater than some fixed finite ordinal. We apply our results to cylindric algebras and Halmos quasipolyadic algebras with equality. As an application to our algebraic result we obtain a strong incompleteness theorem (in the sense that validitities are not captured by finitary Hilbert style axiomatizations) for an algebraizable extension of \(L_{\omega,\omega}\). (shrink)

SC, CA, QA and QEA denote the class of Pinter’s substitution algebras, Tarski’s cylindric algebras, Halmos’ quasi-polyadic and quasi-polyadic equality algebras, respectively. Let . and . We show that the class of n dimensional neat reducts of algebras in K m is not elementary. This solves a problem in [2]. Also our result generalizes results proved in [1] and [2].

We prove several interpolation theorems for many-valued infinitary logic with quantifiers by studying expansions of MV-algebras in the spirit of polyadic and cylindric algebras. We prove for various reducts of polyadic MV-algebras of infinite dimensions that if is the free algebra in the given signature,, is in the subalgebra of generated by, is in the subalgebra of generated by and, then there exists an interpolant in the subalgebra generated by and such that. We call this a varying interpolation property because (...) the integer depends on the inequality. We also address cases where this interpolation property fails, but other weaker ones hold. One such interpolation theorem says that though an interpolant may not be found as above, an interpolant can always be found if finitely many universal quantifiers are applied to making it smaller and the same number of existential quantifiers are applied to making it bigger. This number of quantifiers also varies; it depends on the inequality. Se.. (shrink)

Let α be an arbitrary infinite ordinal, and. In [26] we studied—using algebraic logic—interpolation and amalgamation for an extension of first order logic, call it, with α many variables, using a modal operator of a unimodal logic that contributes to the semantics. Our algebraic apparatus was the class of modal cylindric algebras. Modal cylindric algebras, briefly, are cylindric algebras of dimension α, expanded with unary modalities inheriting their semantics from a unimodal logic such as, or. When modal cylindric algebras based (...) on are just cylindric algebras, that is to say,. This paper is a sequel to [26], where we study algebraically other properties of. We study completeness and omitting types (s) for s by proving several representability results for so‐called dimension complemented and locally finite. Furthermore, we study the notion of atom‐canonicity for, the variety of n‐dimensional modal cylindric algebras. Atom canonicity, a well known persistence property in modal logic, is studied in connection to for, which is restricted to the first n variables. We further continue our study of interpolation in [26] for algebraizable extensions of by studying using both algebraic logic and category theory. Our main results on are Theorems 3.7, 4.4 & 4.6, while our main results on amalgamation are Theorems 5.7, 5.10, 5.13 & 5.16. (shrink)

Fix 2 < n < ω and let C A n denote the class of cylindric algebras of dimension n. Roughly, C A n is the algebraic counterpart of the proof theory of first-order logic restricted to the first n var...

We give a simple new construction of representable relation algebras with non-representable completions. Using variations on our construction, we show that the elementary closure of the class of completely representable relation algebras is not finitely axiomatizable.

We give a simple new construction of representable relation algebras with non-representable completions. Using variations on our construction, we show that the elementary closure of the class of completely representable relation algebras is not finitely axiomatizable.

We prove that the existence of atomic models for countable atomic theories does not hold for Ln the first order logic restricted to n variables for finite n > 2. Our proof is algebraic, via polyadic algebras. We note that Lnhas been studied in recent times as a multi-modal logic with applications in computer science. 2000 MATHEMATICS SUBJECT CLASSIFICATION. 03C07, 03G15.

Spam electronic mails (emails) refer to harmful and unwanted commercial emails sent to corporate bodies or individuals to cause harm. Even though such mails are often used for advertising services and products, they sometimes contain links to malware or phishing hosting websites through which private information can be stolen. This study shows how the adaptive intelligent learning approach, based on the visual anti-spam model for multi-natural language, can be used to detect abnormal situations effectively. The application of this approach is (...) for spam filtering. With adaptive intelligent learning, high performance is achieved alongside a low false detection rate. There are three main phases through which the approach functions intelligently to ascertain if an email is legitimate based on the knowledge that has been gathered previously during the course of training. The proposed approach includes two models to identify the phishing emails. The first model has proposed to identify the type of the language. New trainable model based on Naive Bayes classifier has also been proposed. The proposed model is trained on three types of languages (Arabic, English and Chinese) and the trained model has used to identify the language type and use the label for the next model. The second model has been built by using two classes (phishing and normal email for each language) as a training data. The second trained model (Naive Bayes classifier) has been applied to identify the phishing emails as a final decision for the proposed approach. The proposed strategy is implemented using the Java environments and JADE agent platform. The testing of the performance of the AIA learning model involved the use of a dataset that is made up of 2,000 emails, and the results proved the efficiency of the model in accurately detecting and filtering a wide range of spam emails. The results of our study suggest that the Naive Bayes classifier performed ideally when tested on a database that has the biggest estimate (having a general accuracy of 98.4%, false positive rate of 0.08%, and false negative rate of 2.90%). This indicates that our Naive Bayes classifier algorithm will work viably on the off chance, connected to a real-world database, which is more common but not the largest. (shrink)

BackgroundObstetrics and gynaecology always has reputation for being a highly litigious. The field of obstetrics and gynaecology is surrounded by different circumstances that stimulate the doctors to practice defensive medicine.MethodsThis study was directed to assess the extent and the possible effect of defensive medicine phenomenon on medical decision making among different grades of obstetric and gynaecologic Sudanese doctors, and to determine any experience of medical litigations with respect to sources and factors associated with it.ResultsA total of 117 doctors were approached, (...) their distribution according to job description was as follow: consultants registrars and specialists. The majority 89.7 % had the impression that litigation against doctors are increasing and 27.6 % had a direct experience of litigation. In this study less than one half of the surveyed doctors knew the concept of defensive medicine and 71.8 % reported practicing one or another form of defensive medicine. The different sources of the litigations reported by the doctors included: maternal death, perinatal death, other {misdiagnosis, intra-uterine fetal death, uterine perforation, rupture uterus}, fetal distress, injury to viscera and shoulder dystocia. In this study the experience of medical litigation was significantly observed among those who worked in area of blame culture. In logistic regression model, there was no significant difference between those who knew the concept of defence medicine and those who didn’t.ConclusionThere should be strategic plan to reduce the practice of defensive medicine and medical litigation against doctors. (shrink)

We give a novel application of algebraic logic to first order logic. A new, flexible construction is presented for representable but not completely representable atomic relation and cylindric algebras of dimension n (for finite n > 2) with the additional property that they are one-generated and the set of all n by n atomic matrices forms a cylindric basis. We use this construction to show that the classical Henkin-Orey omitting types theorem fails for the finite variable fragments of first order (...) logic as long as the number of variables available is > 2 and we have a binary relation symbol in our language. We also prove a stronger result to the effect that there is no finite upper bound for the extra variables needed in the witness formulas. This result further emphasizes the ongoing interplay between algebraic logic and first order logic. (shrink)

We show that the U.S. anti-discriminatory laws prohibiting discrimination in the workplace based on sexual orientation and gender identity identities) spur innovation, which ultimately leads to higher firm performance. We use the Human Rights Campaign’s Corporate Equality Index of 398 U.S. firms between 2011 and 2014, and find a significantly positive relationship between CEI and firm innovation. We also find that an interacting effect of CEI and firm innovation leads to higher firm performance. We use our understanding of Rawls’ Theory (...) of Justice and stakeholder theory to show that firms with workplace diversity policies are likely to be more innovative and perform better than those without such policies. Our results are robust to endogeneity, reverse causality and simultaneity issues. Our results will trigger debate in similar markets around the globe on the economic benefits of LGBT workplace diversity policies for firms. (shrink)

The purpose of this paper is modelling and controlling the spread of COVID-19 disease in Morocco. A nonlinear mathematical model with two subclasses of infectious individuals is proposed. The population is divided into five classes, namely, susceptible, exposed, undiagnosed infectious, diagnosed patients, and removed individuals. To reflect the real dynamic of the COVID-19 transmission in Morocco, the real reported data are used for estimating model parameters. Two controls representing screening effort and limited treatment are considered. Based on viability theory and (...) set-valued analysis, a Lyapunov function is constructed such that both exposed and infected populations are decreased to zero asymptotically. The corresponding controls are derived via a continuous selection of adequately designed feedback map. Numerical simulations are presented with three scenarios. Our results show that when only one control is to be applied, screening is the most effective in decreasing the number of people in the three infected compartments, whereas combining both controls is found to be highly effective and leads to a significant improvement in the epidemiological situation of Morocco. To the best of our knowledge, this work is the first one that applies the set-valued approach to a controlled COVID-19 model which agrees with the observed cases in Morocco. (shrink)