bluuebunny/crossref_metadata_2025 huggingface dataset:
More on Modal Aspects of Default Logic1
Authors: Marek V. Wiktor , Truszczynski Miroslaw
Published: May 2021

Investigations of default logic have been so far mostly concerned with the notion of an extension of a default theory. It turns out, however, that default logic is much richer. Namely, there are other natural classes of objects that might be associated with default reasoning. We study two such classes of objects with emphasis on their relations with modal nonmonotonic formalisms. First, we introduce the concept of a weak extension and study its properties. It has long been suspected that there are close connections between default and autoepistemic logics. The notion of weak extension allows us to precisely describe the relationship between these two formalisms. In particular, we show that default logic with weak extensions is essentially equivalent to autoepistemic logic, that is, nonmonotonic logic KD45. In the paper we also study the notion of a set of formulas closed under a default theory. These objects are shown to correspond to stable theories and to modal logic S5. In particular, we show that skeptical reasoning with sets closed under default theories is closely related with provability in S5. As an application of our results we determine the complexity of reasoning with weak extensions and sets closed under default theories.
On Some Equivalence Relations for Probabilistic Processes1
Authors: Huynh Dung T. , Tian Lu
Published: May 2021

In this paper, we investigate several equivalence relations for probabilistic labeled transition systems: bisimulation equivalence, readiness equivalence, failure equivalence, trace equivalence, maximal trace equivalence and finite trace equivalence. We formally prove the inclusions (equalities) among these equivalences. We also show that readiness, failure, trace, maximum trace and finite trace equivalences for finite probabilistic labeled transition systems are decidable in polynomial time. This should be contrasted with the PSPACE completeness of the same equivalences for classical labeled transition systems. Moreover, we derive an efficient polynomial time algorithm for deciding bisimulation equivalence for finite probabilistic labeled transition systems. The special case of initiated probabilistic transition systems will be considered. We show that the isomorphism problem for finite initiated labeled probabilistic transition systems is NC(1) equivalent to graph isomorphism.
An Automata-Theoretic Decision Procedure for Propositional Temporal Logic with Since and Until1
Authors: Ramakrishna Y.S. , Moser L.E. , Dillon L.K. , Melliar-Smith P.M. , Kutty G.
Published: May 2021

We present an automata-theoretic decision procedure for Since/Until Temporal Logic (SUTL), a linear-time propositional temporal logic with strong non-strict since and until operators. The logic, which is intended for specifying and reasoning about computer systems, employs neither next nor previous operators. Such operators obstruct the use of hierarchical abstraction and refinement and make reasoning about concurrency difficult. A proof of the soundness and completeness of the decision procedure is given, and its complexity is analyzed.
On Grammatical Inference and Derivational Complexity of Context-Free Grammars
Authors: Mäkinen Erkki
Published: May 2021

Derivational complexity related to leftmost derivations of context-free grammars is studied by defining a new complexity measure based on characteristic samples of left Szilard languages.
Relating Distributed, Temporal and Causal Observations of Simple Processes1
Authors: Aceto Luca
Published: May 2021

The noninterleaving equivalences that have been proposed in the literature may be roughly divided into three classes, depending on the kind of observational scenarios underlying them. Some of them distinguish parallelism from nondeterminism by admitting explicit observations of the causal structure of systems; some others are based on the observation of distribution and still others on the assumption that actions have duration. In general, these three observational scenarios give rise to equivalences of incomparable discriminating power. In this paper, we show that three representative equivalences of the aforementioned classes, namely timed equivalence [Hen88], distributed bisimulation [CH89] and causal bisimulation [DD88], coincide over a language for finite parallel processes without communication and restriction. The proof of this result is algebraic in style and relies on a theorem giving a finite, ω-complete axiomatization of causal bisimulation over the language under consideration. We also give a model for our language based upon causal trees and prove that it is fully abstract with respect to the largest congruence contained in strong bisimulation and preserved by a very simple form of action refinement [AH89].
Logical Characterizations of Bounded Query Classes I: Logspace Oracle Machines
Authors: Stewart Iain A.
Published: May 2021

We consider three sub-logics of the logic (±HP)*[FOs] and show that these sub-logics capture the complexity classes obtained by considering logspace deterministic oracle Turing machines with oracles in NP where the number of oracle calls is unrestricted and constant, respectively; that is, the classes LNP and LNP[O(1)]. We conclude that if certain logics are of the same expressibility then the Polynomial Hierarchy collapses. We also exhibit some new complete problems for the complexity class LNP via projection translations (the first to be discovered: projection translations are extremely weak logical reductions between problems) and characterize the complexity class LNP[O(1)] as the closure of NP under a new, extremely strict truth-table reduction (which we introduce in this paper).
Tableaux Versus Resolution a Comparison
Authors: Ophelders W.M.J. , De Swart H.C.M.
Published: May 2021

In [13] we have presented the ideas underlying an automated theorem prover based on tableaux extended with unification under restrictions. In [6] a full description of an implementation of this theorem prover in PROLOG is given. In this paper we first shortly repeat the main ideas, referring to [13] for more details. Next we present the test results of our theorem prover mainly with respect to Pelletier’s 75 problems for testing automatic theorem provers ([7]). We also give a comparison of our results with the results obtained by the resolution-based theorem provers PCPROVE and OTTER and by the tableau-based theorem provers of M. Fitting and S. Reeves. Short discussions of these theorem provers accompany the test results. For more elaborate discussions the reader is referred to [6].
Default Logic Models of Certain Inheritance Systems with Exceptions
Authors: Garlatti Serge
Published: May 2021

Representation systems based on inheritance networks are founded on the hierarchical structure of knowledge. Such representation is composed of a set of objects and a set of is-a links between nodes. Objects are generally defined by means of a set of properties. An inheritance mechanism enables us to share properties across the hierarchy, called an inheritance graph. It is often difficult, even impossible to define classes by means of a set of necessary and sufficient conditions. For this reason, exceptions must be allowed and they induce nonmonotonic reasoning. Many researchers have used default logic to give them formal semantics and to define sound inferences. In this paper, we propose a survey of the different models of nonmonotonic inheritance systems by means of default logic. A comparison between default theories and inheritance mechanisms is made. In conclusion, the ability of default logic to take some inheritance mechanisms into account is discussed.
Spatial Mental Models in Cognitive Systems
Authors: Chen Su-Shing
Published: May 2021

This paper is concerned with a mathematical foundation of representation issues and reasoning schemes of spatial information and knowledge. Spatial mental models in cognitive systems using a hybrid symbolic AI and highly parallel (e.g., neural networks or connectionism) framework of deductive and inductive reasoning in spatial domains will be constructed. The framework for “induction” of Holland, Holyoak, Nisbett, and Thagard was proposed as the classifer system approach to inferential and learning processes in biological cognitive systems which remedies the inadequacies of the classical logical approaches to induction: formal inductive logics. In this paper, we use a hybrid symbolic and highly parallel approach instead of the classifier system only.
Selected Algorithms of Machine Learning from Examples
Authors: Grzymala-Busse Jerzy W.
Published: May 2021

This paper presents and compares two algorithms of machine learning from examples, ID3 and AQ, and one recent algorithm from the same class, called LEM2. All three algorithms are illustrated using the same example. Production rules induced by these algorithms from the well-known Small Soybean Database are presented. Finally, some advantages and disadvantages of these algorithms are shown.
Learning Relations: An Evaluation of Search Strategies
Authors: Baroglio Cristina , Botta Marco , Giordana Attilio
Published: May 2021

Inducing concept descriptions in first order logic is inherently a complex task; then, heuristics are needed to keep the problem to manageable size. In this paper we explore the effect of alternative search strategies, including the use of information gain and of a-priori knowledge, on the quality of the acquired relations, intended as the ability to reconstruct the rule used to generate the examples. To this aim, an artificial domain has been created, in which the experimental conditions can be kept under control, the “solulion” of the learning problem is known and a perfect theory is available. Another investigated aspect is the impact of more complex description languages, such as, for instance, including numerical quantifiers. The resultS show that the information gain criterion is too greedy to be useful when the concepts have a complex internal structure; however, this drawback is more or less shared with any purely statistical evaluation criterion. The addition of parts of the available domain theory increases the obtained performance level. Similar results have been previously obtained on a number of real applications and of test-cases taken from standard machine learning data bases.
On the Algebraization of Some Gentzen Systems1
Authors: Rebagliato Jordi , Verdú Ventura
Published: May 2021

In this paper we study the algebraization of two Gentzen systems, both of them generating the implication-less fragment of the intuitionistic propositional calculus. We prove that they are algebraizable, the variety of pseudocomplemented distributive lattices being an equivalent algebraic semantics for them, in the sense that their Gentzen deduction and the equational deduction over this variety are interpretable in one another, these interpretations being essentially inverse to one another. As a consequence, the consistent deductive systems that satisfy the properties of Conjunction, Disjunction and Pseudo-Reductio ad Absurdum are described by giving apropriate Gentzen systems for them. All these Gentzen systems are algebraizable, the subvarieties of the variety of pseudocomplemented distributive lattices being their equivalent algebraic semantics respectively. Finally we give a Gentzen system for the conjunction and disjunction fragment of the classical propositional calculus, prove that the variety of distributive lattices is an equivalent algebraic semantics for it and give a Gentzen system, weaker than the latter, the variety of lattices being an equivalent algebraic semantics for it.
Lambda Calculus Characterizations of Poly-Time
Authors: Leivant Daniel , Marion Jean-Yves
Published: May 2021

We consider typed λ-calculi with pairing over the algebra W of words over {0, 1}, with a destructor and discriminator function. We show that the poly-time functions are precisely the functions (1) λ-representable using simple types, with abstract input (represented by Church-like terms) and concrete output (represented by algebra terms); (2) λ-representable using simple types, with abstract input and output, but with the input and output representations differing slightly; (3) λ-representable using polymorphic typing with type quantification ranging over multiplicative types only; (4) λ-representable using simple and list types (akin to ML style) with abstract input and output; and (5) λ-representable over the algebra of flat lists (in place of W), using simple types, with abstract input and output.
Primitive Recursion with Existential Types1
Authors: Urzyczyn Pawel
Published: May 2021

We consider computability over abstract structures with help of primitive recursive definitions (an appropriate modification of Gödel’s system T). Unlike the standard approach, we do not assume any fixed representation of integers, but instead we allow primitive recursion to be polymorphic, so that iteration is performed with help of counters viewed as objects of an abstract type Int of arbitrary (hidden) implementation. This approach involves the use of existential quantification in types, following the ideas of Mitchell and Plotkin. We show that the halting problem over finite interpretations is primitive recursive for each program involving primitive recursive definitions. Conversely, each primitive recursive set of interpretations is defined by the termination property of some program.
Dependencies in Relational Databases Algebraic and Logical Approach 1
Authors: Rauszer Cecylia M.
Published: May 2021

Functional and multivalued dependencies are expressed in terms of special equivalence relations, called indiscernibility relations. Subsequently, an algebra of indiscernibility relations of a given relational database is introduced and examined. It is shown that a dependency holds in a database if and only if a corresponding algebraic formula is equal to the greatest element in the algebra. In addition, a formal deductive system, called D-logic is defined. This system corresponds to a fragment of non-classical logic. An equivalence theorem showing that D-logic describes, in an adequate way, properties of functional and multivalued dependencies is stated. D-logic and D-lattices are instrumental in proving several properties of dependencies. Examples showing how these techniques are valuable in proving theorems about dependencies are given.
Undecidable Fragments of Term Algebras with Subterm Relation
Authors: Marongiu Gabriele , Tulipani Sauro
Published: May 2021

In this paper we give a new proof of undecidability results about term algebras with subterm relation. This proof yields a novel result which states that, in presence of the subterm relation and in signatures with symbols of arity greater than one, the ∑ 1 theory of rational trees is properly included in the ∑ 1 theory of infinite trees. Moreover, these theories are quite different; in fact, the first is r.e. and the second has degree not less than ∑ 1 1 . Here, in analogy with the arithmetical hierarchy, we call Δ 0 the prenex formulas, whose quantifiers are bounded by the predicate ⩽, and we call ∑ 1 the formulas which are existential quantification of Δ 0 formulas.
Using Hoare Logic in a Process Algebra Setting
Authors: Bergstra J.A. , Middelburg C.A.
Published: May 2021

This paper concerns the relation between process algebra and Hoare logic. We investigate the question whether and how a Hoare logic can be used for reasoning about how data change in the course of a process when reasoning equationally about that process. We introduce an extension of ACP (Algebra of Communicating Processes) with features that are relevant to processes in which data are involved, present a Hoare logic for the processes considered in this process algebra, and discuss the use of this Hoare logic as a complement to pure equational reasoning with the equational axioms of the process algebra.
Scattered Context Grammars with One Non-Context-Free Production are Computationally Complete
Authors: Křivka Zbyněk , Meduna Alexander
Published: May 2021

This paper investigates the reduction of scattered context grammars with respect to the number of non-context-free productions. It proves that every recursively enumerable language is generated by a scattered context grammar that has no more than one non-context-free production. An open problem is formulated.
Non-Self-Embedding Grammars and Descriptional Complexity
Authors: Pighizzini Giovanni , Prigioniero Luca
Published: May 2021

Non-self-embedding grammars are a subclass of context-free grammars which only generate regular languages. The size costs of the conversion of non-self-embedding grammars into equivalent finite automata are studied, by proving optimal bounds for the number of states of nondeterministic and deterministic automata equivalent to given non-self-embedding grammars. In particular, each non-self-embedding grammar of size s can be converted into an equivalent nondeterministic automaton which has an exponential size in s and into an equivalent deterministic automaton which has a double exponential size in s. These costs are shown to be optimal. Moreover, they do not change if the larger class of quasi-non-self-embedding grammars, which still generate only regular languages, is considered. In the case of letter bounded languages, the cost of the conversion of non-self-embedding grammars and quasi-non-self-embedding grammars into deterministic automata reduces to an exponential of a polynomial in s.
Generative Capacity of Contextual Grammars with Subregular Selection Languages*
Authors: Truthe Bianca
Published: May 2021

A contextual grammar is a language generating mechanism inspired by generating sentences in natural languages. An existing string can be extended to a new string of the language by adjoining a context before and behind the string or by inserting it into the string around some subword. The first mode is called external derivation whereas the second mode is called internal derivation. If conditions are given, around which words which contexts can be adjoined, we speak about contextual grammars with selection. We give an overview about the generative capacity of contextual grammars (working externally or internally) where the selection languages belong to subregular language classes. All languages generated by contextual grammars where all selection languages are elements of a certain subregular language family form again a language family. We compare such families which are based on finite, monoidal, nilpotent, combinational, definite, suffix-closed, ordered, commutative, circular, non-counting, power-separating, or union-free languages, or based on languages defined by restrictions regarding the descriptional complexity.
Evaluating operation efficiency of public transportation: A three-stage DEA method
Authors: Li Jing , Xia Ziyang , Yang Yang , Cui Yu , Li Xueyan , Zhu Xin
Published: May 2021

Based on the traffic data of Beijing, this paper uses the principal component analysis method to establish a reliable indicator system of efficiency evaluation. It then uses the three-stage DEA model to evaluate the efficiency of rail transit and ground bus in 2008–2017, which describes the development trend and effective situation of rail transit and ground bus in Beijing in the past ten years. Besides, it also compares and analyzes the calculated efficiency before and after the adjustment. The research shows that the overall operation efficiency of rail transit is high and rising year by year, but the overall operation efficiency of ground bus is low and declining in recent years. The number of vehicles, as an environmental variable, leads to the virtual high and causes a significant impact on the comprehensive efficiency and pure technical efficiency of rail transit, but has little impact on the scale efficiency. Also, it leads to the virtual high of comprehensive efficiency and pure technical efficiency of ground bus but underestimates the scale efficiency.
User logistics profiling for terminal distribution based on adaptive large adjacent search
Authors: Li Qinghua , Li Yisong
Published: May 2021

With the volume growth of delivery business, terminal distribution plays a more and more important role in logistics as it faces consumers directly. User Profiling as an important tool to realize user-centric interaction design can provide more accurate information for terminal distribution. By user profiling, the design team can better understand and satisfy users and their demands for the product and service. This paper studies the problem of terminal delivery route planning considering user logistic profiles. It mainly generates user profiles from two aspects: consumers’ preference for self-pickup services and consumers’ complaint tendencies. Based on the results of user profiles, an Adaptive Large Adjacent Search algorithm is established to design the delivery route of terminal distribution and determine the appropriate delivery strategy to reduce delivery costs and improve customer satisfaction.
A price discrimination based Cournot game model for high-speed rail and airline
Authors: Li Jinyu , Li Xuemei , Ma Ning
Published: May 2021

This study investigates the competitive game between high-speed rail and airline on price, profit and social welfare, taking into account the airline price discrimination. We build a multi-level price competition pricing Cournot model for high-speed rail and airline to shed light on the HSR-air transport competition impact of pricing discrimination when airline could offer multi-level class seats, and analyze the optimal pricing strategy of airlines and high-speed rail operators and their impact on social welfare. The analytical results demonstrate that: airline price dis-crimination will increase social welfare and reduce consumer surplus, both airfare and airline profit increase as the degree of price discrimination increases welfare. However, HSR fare and profit decreases with the increase of the degree of price discrimination.
The correlations of transportation with regional economy and demographic space1
Authors: Wu Xiaoping , Wu Peng , Guo Zihan
Published: May 2021

Based on the precise logical analysis method, the paper constructs a comprehensive evaluation model of transportation superiority in terms of transportation network density, the influence of transportation arteries, and regional location-specific advantages, then select Southwest China as a case to evaluate the transportation superiority and analyze the correlations of transportation with regional economic development and population distribution. The results show that there is a positive correlation between regional transportation superiority and regional population density as well as GDP per capita in the spatial distribution. Finally, by using the fuzzy logic analysis method, we propose countermeasures and suggestions for the impact of transportation integration on regional economic development and population distribution.
An evidence theory based approach for group decision making under uncertainty
Authors: Hu Limei , Tan Chunqiao , Deng Hepu
Published: May 2021

With the changing business environment and the active participation of various stakeholders in the decision making process, it plays an increasingly important role to the weight of decision makers and the preference information given by decision makers. This paper presents a novel approach for group decision making under uncertainty with the involvement of the third-party evaluator in the decision making process. Recognizing the challenge in adequately determining the weight of decision makers in group decision making, the evidence theory is appropriately used with the involvement of the third-party evaluator. To effectively model the uncertainty and imprecision in the decision making process, fuzzy preference relations are used for better representing the subjective assessment of individual decision makers. To adequately determine the ranking of available alternatives, the logarithmic least square method is applied for appropriately aggregating the fuzzy preference relation of individual decision makers. A group consensus index is developed for facilitating consensus building in group decision making. This leads to better group decisions being made. A real-world application is presented that shows the proposed approach is effective in solving group decision making problems under uncertainty.
Ideal convergent sequence spaces of fuzzy star–shaped numbers
Authors: Khan Vakeel A. , Tuba Umme , Ashadul Rahaman SK. , Ahmad Ayaz
Published: May 2021

In 1990, Diamond [16] primarily established the base of fuzzy star–shaped sets, an extension of fuzzy sets and numerous of its properties. In this paper, we aim to generalize the convergence induced by an ideal defined on natural numbers ℕ , introduce new sequence spaces of fuzzy star–shaped numbers in ℝ n and examine various algebraic and topological properties of the new corresponding spaces as well. In support of our results, we provide several examples of these new resulting sequences.
Empirical evaluation on the effect of enterprise quality immune response based on EMIBSGTD-TAS
Authors: Yang Xu , Guo Yu , Liu Qiang , Zhang Deming
Published: May 2021

Effective enterprise quality immune response can grasp the “pathogenesis”, “clinical manifestations” and “treatment” of enterprise quality dissident factors, which is the goal pursued continuously by enterprise quality management. Drawing on the theory of enterprise immunity, construct the evaluation index system of enterprise quality immune response effect, and use the evaluation model of interval binary semantic grey target decision based on two-dimensional association sampling (EMIBSGTD-TAS) to evaluate the quality immune response effect of the selected target company. The boundary and internal distribution situation weaken the influence of the extreme value of the index on the decision result, and introduce the interval binary semantic set value statistical method to determine the index weight, reduce the information loss and fuzzy error. It can be seen from the evaluation results that the model has practicability and feasibility, and provides a new idea for the evaluation of the effect of enterprise quality immune response.
Physician burnout and professional satisfaction in orthopedic surgeons during the COVID-19 Pandemic
Authors: Lazarides Alexander L. , Belay Elshaday S. , Anastasio Albert T. , Cook Chad E. , Anakwenze Oke A.
Published: May 2021

BACKGROUND: Burnout and professional satisfaction is an often an overlooked component for healthcare outcomes; the COVID-19 pandemic represents an unprecedented stressor that could contribute to higher levels of burnout. OBJECTIVES: Our primary objective was to evaluate the association of a battery of fulfillment, job satisfaction change, COVID-19 concerns, and coping measures. Our secondary objective was to determine whether the fulfillment and coping measures differed by gender and by experience levels among a battery of physician specialties. METHODS: The study was a purposive sample of convenience. Study participants included all trainees and attending orthopedic surgeons from our academic institution; all participants were invited to complete a survey built around a validated measure of professional fulfillment aimed at assessing response to acute change and stressors. We performed univariate statistics and a matrix correlational analysis to correlate different survey domains with variables of interest. RESULTS: The survey was sent electronically to 138 individuals; 63 surveys were completed (response rate = 45.7%). Twenty-seven (42.8%) individuals met the threshold criteria for fulfillment whereas 10 (15.9%) met the threshold for burnout. We found that surgeon perspectives on COVID-19 were not associated with burnout or professional fulfillment. Burnout was inversely associated with professional fulfillment (R = –0.35). Support seeking was noted to be correlated with professional fulfillment (R = 0.37). CONCLUSIONS: Stressors related to COVID-19 pandemic were not correlated with physician burnout and fulfillment. This held true even when stratifying by gender and by attending vs. trainee. Continued efforts should be implemented to protect against physician burnout and ensure professional fulfillment for Orthopedic surgeons.
Italian version of the cornell musculoskeletal discomfort questionnaire (CMDQ-I): Translation, cultural adaptation and validation
Authors: Magnifica F. , Colagrossi F. , Aloisi A. , Politi S. , Peretti A. , Berardi A. , Galeoto G. , Tofani M. , Pierelli F.
Published: May 2021

BACKGROUND: Almost 25%of workers in the European Union suffer from back pain, and 23%complain of muscle pain. Sixty-two percent of workers carry out repetitive operations with their hands or arms, 46%work in painful or tired positions and 35%carry or handle loads. OBJECTIVE: This study aimed to translate, culturally adapt and validate the Italian version of the Cornell Musculoskeletal Discomfort Questionnaire (CMDQ-I). METHODS: Translation and cultural adaptation procedures followed international guidelines. Participants were recruited from among the personnel components of the Italian Air Force, who were between 18 and 65 years old. Cronbach’s alpha and the intraclass correlation coefficient (ICC) were calculated to assess internal consistency and stability, respectively. The CDMQ-I was administered together with the Visual Analogic Scale (VAS), and the validity was evaluated using Pearson’s correlation coefficient. RESULTS: All CDMQ-I items were either identical or similar in meaning to the original version’s items. The scale was administered twice with a retest after seven to 10 days to 66 participants. Cronbach’s alpha was higher than 0.761, and the ICC ranged between 0.737 and 0.952. Pearson’s correlation coefficient showed positive and significant correlations (p > 0.01). CONCLUSIONS: The study produced an Italian version of the CMDQ with good reliability and validity. This scale is a useful tool to investigate the frequency and intensity of musculoskeletal disorders in various categories of workers.
An investigation of an ergonomics intervention to affect neck biomechanics and pain associated with smartphone use
Authors: Tang Minghao , Sommerich Carolyn M. , Lavender Steven A.
Published: May 2021

BACKGROUND: Neck discomfort and pronounced neck flexion have been associated with smartphone use. OBJECTIVE: Eye glasses with a 90 deg prism in each lens were investigated as a potential intervention to reduce awkward head and neck postures during activities involving viewing the device. METHODS: Sixteen smartphone users with neck pain and 9 asymptomatic users performed a texting task on a smartphone with and without the prism glasses, in sitting and standing postures in a laboratory setting. RESULTS: Cervical erector spinae and upper trapezius muscle activity, head posture and motion, performance, discomfort and other subjective perceptions were assessed. Prism glasses reduced neck extensor muscle activity, neck flexion, and head tilt compared to the direct view. In the symptomatic group, the intervention produced less neck and shoulder discomfort compared to the direct view. CONCLUSIONS: This intervention could offer an alternative way of interacting with a smartphone while texting in stationary postures, by reducing exposure to pronounced flexed neck and head posture commonly seen in users, and thereby could reduce neck discomfort associated with smartphone use.
Evaluation of occupational and non-occupational risk factors associated with carpal tunnel syndrome in dentists
Authors: Maghsoudipour Maryam , Hosseini Fereshteh , Coh Paul , Garib Seifolah
Published: May 2021

BACKGROUND: Musculoskeletal disorders are very prevalent among dentists. Of these disorders, carpal tunnel syndrome (CTS) is notable. OBJECTIVE: The aim of this study was to investigate the relationship between the occupational and non-occupational risk factors and CTS among dentists. METHODS: It is a cross-sectional study. We evaluated 106 dentists from dental schools in Tehran. We collected data by a general questionnaire, a hand diagram, and physical examination. A nerve conduction velocity (NCV) test was used to confirm the diagnosis of CTS. The analysis was performed using an independent T-test and logistic regressions on SPSS software. RESULTS: The prevalence of CTS among dentists was 17.9%. Significant risk factors of CTS included: vibration exposure greater than two hours per day (OR: 2.5), a wrist diameter ratio of greater than 0.7 (OR: 10.14), and female sex (OR: 13.38). CONCLUSIONS: Exposure to the hand-arm vibration should be considered as an occupational risk factor for CTS in dentists. Female dentists should take more preventive measures.
Correlation of hand functionality and grip strengths with anthropometric measurements
Authors: Tonak Hasan Atacan , Kaya Kara Ozgun , Sahin Sedef
Published: May 2021

BACKGROUND: Using objective anthropometric measurement data and anthropometric ratios, grip strength and hand functionality can be evaluated. OBJECTIVE: The aim of this study was to obtain anthropometric measurements regarding the forearm and hand, to evaluate the hand functionality in addition to hand and finger grip strengths, and to investigate the correlation between these values. METHODS: One-hundred eight-four subjects between 18 and 25 years were included in the study. Forearm and hand anthropometric measurements and ratios were measured. Hand and lateral grip strengths were evaluated. Jebsen Taylor Hand Function Test (JTHFT) was used to assess hand functionality. RESULTS: A statistically weak and consistently negative correlation between the ratios of forearm length to forearm/wrist circumferences and the ratio of hand length to metacarpal head circumference and hand-lateral grip strengths was found. There was a statistically weak and consistently negative correlation between these ratios and the subtests of JTHFT. It was shown that there was a statistically weak–moderate positive correlation between the hand-lateral grip strengths and JTHFT subtests. CONCLUSIONS: In conclusion, when evaluating grip strength and hand functionality, forearm and hand anthropometric measurements and ratios, which could affect the results, should be considered.
The effect of different work-rest schedules on ergonomic risk in poultry slaughterhouse workers
Authors: Dias Natália Fonseca , Tirloni Adriana Seára , Cunha dos Reis Diogo , Moro Antônio Renato Pereira
Published: May 2021

BACKGROUND: Rest breaks are an organizational measure to reduce the high risk of upper limb work-related musculoskeletal disorders (UL-WMSDs) to which slaughterhouse workers are subject. OBJECTIVE: To analyze the effect of different work-rest schedules on ergonomic risk in poultry slaughterhouse workers. METHODS: A total of 36 repetitive tasks was selected in a Brazilian slaughterhouse. Using the Occupational Repetitive Action (OCRA) Checklist, the level of exposure of workers to risk factors of UL-WMSDs in two work-rest schedules was evaluated. In the real condition, 6 rest breaks of 10 minutes were performed, and in the simulated condition, 3 rest breaks of 20 minutes. RESULTS: The right side of the body presented a higher score on the OCRA Checklist (72%of the tasks) than the left side (p = 0.037) in the real condition. Additionally, the OCRA score (18.3±2.5) was significantly lower (p < 0.001) than the simulated condition (21.9±3.0). It was verified that the risk level in simulated condition remained the same in 13 (36%) tasks, while in 23 (64%) tasks there was an increase in the risk level. CONCLUSIONS: Work-rest schedule of 6 breaks of 10 minutes was better than 3 breaks of 20 minutes to reduce the risk of UL-WMSDs in poultry slaughterhouse workers.
Investigating association between job stress dimensions and prevalence of low back pain among hospital nurses
Authors: Choobineh Alireza , Museloo Behbood Khani , Ghaem Haleh , Daneshmandi Hadi
Published: May 2021

BACKGROUND: There are a few studies conducted on job stress dimensions and their relationship with Low Back Pain (LBP) among Iranian nurses. OBJECTIVE: The aim of the current study was to investigate the association between job stress dimensions assessed via Demand-Control-Social Support (DCS) and Effort-Reward Imbalance (ERI) models and prevalence of LBP among Iranian hospital nurses. METHODS: In this cross-sectional study, 495 randomly selected nurses of Shiraz University of Medical Sciences (SUMS) participated. Demographic/occupational questionnaire, the Persian version of the Job Content Questionnaire (P-JCQ) and the Persian version of the ERI Questionnaire (P-ERIQ) were used for data collection. Data were analyzed by SPSS software (version 19) using descriptive statistics, independent sample t-test, and logistic regression. RESULTS: The LBP prevalence was found to be 69.9%. The means±standard deviations of job stress dimensions were obtained as follows: decision latitude: 64.67±6.82, physical job demands: 15.52±2.6, social support: 23.18±3.65, psychological job demands: 38.02±4.98, effort: 8.73±2.62, reward: 23.12±5.31, over-commitment: 12.25±3.09, and effort-reward ratio: 0.86±0.3. The findings revealed that the work experience (OR = 1.56), psychological job demands (OR = 1.082), and effort-reward ratio (OR = 3.43) were predictors for LBP among the study population. CONCLUSION: The prevalence rate of LBP among studied nurses was high. About half of nurses had high psychological demands, low decision latitude and low social support. Based on the effort-reward ratio, nurses had experienced high level of stress. Interventional programs and coping strategies for reduction of work-related stress and, subsequently, prevention of LBP are recommended among hospital nurses.
Acciones de transferencia en primera ayuda psicológica a organizaciones involucradas en acciones de rescate en situaciones de crisis: Relación entre la efectividad y la tendencia individual decisoria
Authors: Azzara Sergio Héctor , Grinhauz Aldana Sol , Azzollini Susana Celeste
Published: May 2021

The work exposes the results of a training in First Psychological Aid, which was performed in order to train the volunteers belonging to organizations responsible for the response in catastrophes. Likewise, the relationship between the tendency to make decisions and effectiveness was analyzed. Five trainings were carried out - 115 volunteers - in different institutions belonging to the province of Buenos Aires, Argentine Republic. The effect of the training on the decision-making effectivity of the volunteers was evaluated through the application of a software. The comparison of the trained group with another one without training evidenced the effectiveness of the training. An inverse association has been found between the individual trend to take affective decisions and effectiveness. Finally, we have come to the conclusion that training improves effectiveness, while the tendency to take urgent affective decisions impacts negatively on this dependent variable
Comparative evaluation of complex fertilizers when applied to strawberries
Authors: Ivanova A , Lekomceva Elena , Sokolova Elena , Tutova Tat'yana , Nesmelova Lyubov'
Published: May 2021

Abstract. The productivity of wild strawberries is significantly determined not only by the biological characteristics of the variety and soil and climatic conditions, but also by agrotechnical techniques and the use of organomineral fertilizers. The effectiveness of the use of mineral fertilizers on strawberries has been proven by numerous studies [5, p. 48; 6, p. 99; 14, p. 233; 15, p. 513; 16, p.101; 17, p. 513]. The purpose is a comparative assessment of the effect of various types of complex fertilizers for strawberries. The task was to study the effect of complex fertilizers on the yield of strawberry and its structure. In 2015–2018, studies were conducted on the introduction of complex fertilizers for wild strawberries, which are used during the growing season to improve their nutrition during periods of maximum consumption of nutrients. Methods. The studies were conducted according to generally accepted methods [4], [7]. The influence of “Azophoska”, “Perm-yagodnoye” and “Fasko-yagodnoye” fertilizers on the yield and elements of its structure in strawberry was studied in the conducted studies. Results. The best results for all the years of research were obtained when using the pre-planting application of the fertilizer “Fasko-yagodnoye”. In this variant, there was a significant increase in the number of berries by 1.8 pcs., their weight by 0.68 g and yield by 0.13 kg/m2. Scientific novelty. For the first time in the conditions of the Udmurt Republic, the effect of the pre-planting application of complex fertilizers “Perm-yagodnoye” and “Fasko-yagodnoye” was studied on strawberry garden. Practical significance. The obtained research results are of great practical value, since it is proved that the productivity of wild strawberries in the Udmurt Republic increases with the use of complex fertilizers.
El hombre del campo en Cuba
Authors: Dorta-Duque, S. J. F.
Published: May 2021

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The Place of the Sahel Region in the Theory of Regional Security Complex
Authors: Varga Márton
Published: May 2021

The theory of regional security complex is one of the main theories of the regional approach of the international security system. The international organisations, the different strategies and concepts use many different definitions for the Sahel region. However, the  ongoing changes of the global and the regional security and the complexity of the crisis of the Sahel region bring up the question  whether the Sahel region is a unit based on the Regional Security Complex Theory or not? Which countries are part of the Sahel? Can it be treated as a region? In this article I will give my answer to that question.
On the Artistic Value of Literary Ekphrasis
Authors: Shangguan Zhangfan , Wang Dong
Published: May 2021

As a language attribute that exists for visual arts, ekphrasis is not only a bridge to communicate poetry and painting, but also an important category in the cross-media and cross-disciplinary research of literature and art. Through the process of recreating paintings by using language as a medium, ekphrasis realizes the conversion from visual art to auditory art, and explores the richness of cognitive creation on the basis of the reproduction of visual art. In this process, the literary narrative diagram shows significant differences from the artistic doctrinal diagram, which are mainly reflected in the three levels of academic guiding ideology, narrative style difference, classic deconstruction and reconstruction, and language style writing paradigm. In addition, literary storytelling plays an important role in the writing of art history and the dissemination of artworks. It provides reference and inspiration for the current cross-border and in-depth integration of literature and art from the perspective of practical creation.
Project-based Learning: Connotation, Characteristics and Misunderstandings
Authors: Guo Peigeng
Published: May 2021

As a kind of teaching mode, project-based learning starts from the driving problems in the real world, aiming to solve learning problems, improve students' innovation ability and practical ability, as well as promote students' deep learning. It makes a vital difference in solving the current difficulties in reading teaching, which is characterized by process, authenticity and development. Due to the reading teaching is still in exploration stage from the perspective of project-based learning, there are inevitable problems in the actual teaching process, including improper time arrangement and lack of planning. Besides, learning is a mere formality, lacking of effectiveness. So teachers need to be more careful to improve the teaching quality and efficiency of project-based learning.
The effect of the drug “Bendamin” on the biochemical parameters of the blood of dogs in heart failure
Authors: Varkholiak I. S. , Gutyj B. V.
Published: May 2021

Experimental studies obtained in recent years indicate the urgency of developing drugs of complex action to prevent the development of cardiovascular disease in dogs. This requires a much deeper study of the pathogenesis of heart failure, including cardiomyopathy. The aim of the study was to investigate the effect of the drug “Bendamin” on the biochemical parameters of the blood of dogs in heart failure. Two groups of dogs were formed for research: control (healthy) and experimental (sick). The 30-day experiment included 10 dogs of the control group and 10 dogs of the experimental (sick) breed of spaniel and dog 10–12 years of age. Treatment regimen for sick dogs: furosemide was administered orally on an empty stomach at 2 mg/kg every 12 hours; enalapril was administered orally at 0.5 mg/kg every 12 hours; bendamine was administered orally on an empty stomach at 20 mg/kg every 24 hours. It is recommended to divide the dose into two doses. An increase in the activity of aminotransferases (ALT by 59.2 %, AST – by 51.9 %) was found in the serum of dogs at heart failure. An increase in alkaline phosphatase activity was also found, which in the complex is an additional confirmation of changes in the heart muscle. Lactate dehydrogenase activity increased in the blood of sick dogs by 23.5 %. Minor changes in the content of total bilirubin and urea in the serum of sick dogs indicate the initial stage of liver pathology with impaired liver function due to congestion in the small circulation. This is also indicated by a decrease in the level of total protein in the blood of sick dogs, which was respectively 57.2 ± 3.57 g/l against the control group of 63.5 ± 4.15 g/l. On the basis of cardiac dysfunction and on the background of congestion, the function of not only the liver but also the kidneys is impaired (the so-called cardiorenal syndrome in heart failure). This is indicated by an increase in urea and creatinine by 38.5 and 36.9 %, respectively, compared with animals in the control group. The use of the drug “Bendamin” alleviated the manifestations of functional failure of the heart, liver and kidneys, as indicated by biochemical studies. Studies confirm the feasibility of using the drug “Bendamin” in dogs with the development of heart failure. The use of the drug “Bendamine” in patients with heart failure in dogs had a positive effect on the restoration of hematopoiesis and the normalization of biochemical parameters of the blood.