Search Results (2,465)

Objective: The aim of this in vitro investigation is to study the effect of endodontic cavity design on interfacial voids, class II resin composite sealing ability, and fracture resistance in mandibular premolars. Methods: A total of 48 single-rooted mandibular premolars received compound class II preparations with either traditional flare access cavities (group A) or contracted endodontic cavity preparations (group B). Each study group was subdivided according to the coronal restoration into two sub-groups as α and β. In the α group, a microhybrid composite was used after etch-and-rinse bonding technique using an MDP-containing universal adhesive. In the β group, a self-adhesive composite was used as coronal restoration after endodontic treatment (n = 12) for each subgroup. A micro-CT analysis was performed to assess the obturation interfacial voids and tracing of class II cervical interfacial adaptation. The tooth fracture resistance testing was then performed adding an extra group of 12 sound non-prepared teeth, which were tested as the control for fracture strength testing. A one-way ANOVA and post-hoc testing were used together with descriptive statistics for an analysis of the mean values of obturation interfacial voids. A two-way ANOVA was used to assess the fracture resistance test results, and to find the influence of endodontic access design and the type of composite material on the fracture resistance testing. Chi-square testing was employed to analyze the cervical interfacial seal of the class II restorations. Results: A one-way ANOVA revealed that there were no statistically significant differences between test groups in the amount of obturation interfacial voids (p > 0.05). There were no statistically significant differences between test groups in terms of cervical interfacial sealing ability (p > 0.05). A two-way ANOVA revealed that no statistically significant differences between test groups including the control group existed in terms of the fracture resistance testing (p > 0.05). Conclusions: Although it does not improve tooth fracture resistance, the contracted endodontic access cavity does not deteriorate the quality of obturation in terms of the interfacial porosity. The self-adhesive composite does not improve the efficiency of cervical interfacial adaptation or tooth fracture resistance regardless of the endodontic access cavity shape, yet it revealed a substantial load-bearing capacity. Full article

This study investigates dietary supplement use among rugby players and their general health, focusing on prevalence and underlying motivations. Involving 92 athletes, it examines the relationship between supplement usage, motivations, and health outcomes using the 36-item Short Form Health Survey and a 24-item ad hoc questionnaire. Findings reveal a high frequency of supplement usage, motivated by desires to enhance performance, appearance, and mood. Significant differences in health-related quality of life are found between users and non-users, particularly in mental health, social functioning, and emotional stability. Motivations like performance enhancement and body shape manipulation were linked to altered health perceptions, indicating the psychosocial impacts of supplementation. This study emphasizes the need to consider the holistic effects of supplements on athlete well-being, advocating for a balanced approach prioritizing both physical and mental health. It calls for increased awareness among athletes, coaches, and sports professionals about the potential risks and benefits of supplement use and the importance of informed decision-making. Additionally, it highlights the need for further research to understand the mechanisms of supplement use and its impact on athlete health, aiming to enhance sports science and promote overall athlete well-being in competitive environments. Full article

The domination problem and three of its variants (total domination, 2-domination, and secure domination) are considered. These problems have various real-world applications, including error correction codes, ad hoc routing for wireless networks, and social network analysis, among others. However, each of them is NP-hard to solve to provable optimality, making fast heuristics for these problems desirable. There are a wealth of highly developed heuristics and approximation algorithms for the domination problem; however, such heuristics are much less common for variants of the domination problem. We redress this gap in the literature by proposing a novel implementation of the cross-entropy method that can be applied to any sensible variant of domination. We present results from experiments that demonstrate that this approach can produce good results in an efficient manner even for larger graphs and that it works roughly as well for any of the domination variants considered. Full article

One of the main security challenges when federating separate Internet of Things (IoT) administrative domains is effective Identity and Access Management, which is required to establish trust and secure communication between federated IoT devices. The primary goal of the work is to develop a “lightweight” protocol to enable authentication and authorization of IoT devices in federated environments and ensure the secure communication of IoT devices. We propose a novel Lightweight Authentication and Authorization Framework for Federated IoT (LAAFFI) which takes advantage of the unique fingerprint of IoT devices based on their configuration and additional hardware modules, such as Physical Unclonable Function, to provide flexible authentication and authorization based on Distributed Ledger technology. Moreover, LAAFFI supports IoT devices with limited computing resources and devices not equipped with secure storage space. We implemented a prototype of LAAFFI and evaluated its performance in the Hyperledger Fabric-based IoT framework. Three main metrics were evaluated: latency, throughput (number of operations or transactions per second), and network resource utilization rate (transmission overhead introduced by the LAAFFI protocol). The performance tests conducted confirmed the high efficiency and suitability of the protocol for federated IoT environments. Also, all LAAFFI components are scalable as confirmed by tests. We formally evaluated LAAFFI security using Verifpal as a formal verification tool. Based on the models developed for Verifpal, we validated their security properties, such as message secrecy, authenticity, and freshness. Our results show that the proposed solution can improve the security of federated IoT environments while providing zero-day interoperability and high scalability. Compared to existing solutions, LAAFFI is more efficient due to the use of symmetric cryptography and algorithms adapted for operations involving IoT devices. LAAFFI supports multiple authorization mechanisms, and since it also offers authentication and accountability, it meets the requirements of Authentication, Authorization and Accounting (AAA). It uses Distributed Ledger (DL) and smart contracts to ensure that the request complies with the policies agreed between the organizations. LAAFFI offers authentication of devices belonging to a single organization and different organizations, with the assurance that the encryption key will be shared with another device only if the appropriate security policy is met. The proposed protocol is particularly useful for ensuring the security of federated IoT environments created ad hoc for special missions, e.g., operations conducted by NATO countries and disaster relief operations Humanitarian Assistance and Disaster Relief (HADR) involving military forces and civilian services, where immediate interoperability is required. Full article

The adoption of UAVs in defence and civilian sectors necessitates robust communication networks. This paper presents a routing protocol for Cognitive Radio Unmanned Aerial Vehicles (CR-UAVs) in Flying Ad-hoc Networks (FANETs). The protocol is engineered to optimize route selection by considering crucial parameters such as distance, speed, link quality, and energy consumption. A standout feature is the introduction of the Central Node Resolution Factor (CNRF), which enhances routing decisions. Leveraging the Received Signal Strength Indicator (RSSI) enables accurate distance estimation, crucial for effective routing. Moreover, predictive algorithms are integrated to tackle the challenges posed by high mobility scenarios. Security measures include the identification of malicious nodes, while the protocol ensures resilience by managing multiple routes. Furthermore, it addresses route maintenance and handles link failures efficiently, cluster formation, and re-clustering with joining and leaving new nodes along with the predictive algorithm. Simulation results showcase the protocol’s self-comparison under different packet sizes, particularly in terms of end-to-end delay, throughput, packet delivery ratio, and normalized routing load. However, superior performance compared to existing methods, particularly in terms of throughput and packet transmission delay, underscoring its potential for widespread adoption in both defence and civilian UAV applications. Full article

In Vehicular Ad Hoc Networks (VANETs), high mobility of vehicles issues a huge challenge to the reliability and security of transmitting packets. Therefore, a Secure and Reliable Opportunistic Routing (SROR) is proposed in this paper. During construction of Candidate Forwarding Nodes (CFNs) set, the relative velocity, connectivity probability, and packet forwarding ratio are taken into consideration. The aim of SROR is to maximally improve the packet delivery ratio as well as reduce the end-to-end delay. The selection of a relay node from CFNs is formalized as a Markov Decision Process (MDP) optimization. The SROR algorithm extracts useful knowledge from historical behavior of nodes by interacting with the environment. This useful knowledge are utilized to select the relay node as well as to prevent the malicious nodes from forwarding packets. In addition, the influence of different learning rate and exploratory factor policy on rewards of agents are analyzed. The experimental results show that the performance of SROR outperforms the benchmarks in terms of the packet delivery ratio, end-to-end delay, and attack success ratio. As vehicle density ranges from 10 to 50 and percentage of malicious vehicles is fixed at 10%, the average of packet delivery ratio, end-to-end delay, and attack success ratio are 0.82, 0.26s, and 0.37, respectively, outperforming benchmark protocols. Full article

This article develops a detailed theory of the fetishes of the modern world. Fetishes may still have their original religious application as talismans and totems, but their actual range is much wider, as I illustrate. I show that a modern fetish satisfies our needs in an unexpected and unlikely manner: it does what it, prima facie, is not supposed to do. How does this happen? To explain, we must trace the construction of fetishes; I do this using some key rhetorical concepts. Paradiastole is a technique of evaluative redescription. It describes the world in value terms as something it is not—we can then ironize the result. If it serves the speakers’ essential interests and satisfies their desires, we have explained a fetish as a good-maker. The fetishization of an object, because of its ironic background, tends to invite critical, meiotic, and even derogatory responses—usually, the issue is and remains essentially contested. For example, early Christians wrote hagiographies that treated some people as saints, thus creating ad hoc beliefs that satisfied their religious interests. I also suggest a different, metonymic understanding of fetishes and their educational benefits. Perhaps my theory is overly permissive, allowing too many fetishes. My final conjecture is that true fetishes function as identity markers; for example, the crucifix is a fetish that defines Christianity. Full article

The aim of this study was to identify the most suitable organizational model for teaching the university subject of Outdoor Activities in relation to learning acquisition and satisfaction. For this purpose, four models were designed, some of which were dominated by traditional education and others by innovative education. The data collection instruments were the Spanish version of the Physical Education of the Sport Satisfaction Instrument, adapted to the university context, and the questionnaire on the contents of the subject designed ad hoc. Data collection was carried out before and after the intervention with a total of 125 students. For data analysis, an ANCOVA was performed. The results showed that there were significant differences in satisfaction between groups (p = 0.029), but not in the boredom scale (p = 0.109). With regard to acquisition of learning between groups, there were significant differences (p = 0.005) in the overall grade of the subject. There were also significant differences in the scores for content taught differently depending on the group (p = 0.003), with a higher score in the most innovative group, the intensive-continuous group, compared to the fractioned (p = 0.005) and classic groups (p = 0.015). It is concluded that there is a positive effect between direct and continuous contact with nature, both in the acquisition of learning and in student satisfaction, with the most innovative model obtaining the best results of the study. Full article

This paper derives some generalized Schur-type stability results of polynomials based on several forms and generalizations of the Eneström–Kakeya theorem combined with the Rouché theorem. It is first investigated, under sufficiency-type conditions, the derivation of the eventually generalized Schur stability sufficient conditions which are not necessarily related to the zeros of the polynomial lying in the unit open circle. In a second step, further sufficient conditions were introduced to guarantee that the above generalized Schur stability property persists within either the same above complex nominal stability region or in some larger one. The classical weak and, respectively, strong Schur stability in the closed and, respectively, open complex unit circle centred at zero are particular cases of their corresponding generalized versions. Some of the obtained and proved results are further generalized “ad hoc” for the case of quasi-polynomials whose zeros might be interpreted, in some typical cases, as characteristic zeros of linear continuous-time delayed time-invariant dynamic systems with commensurate constant point delays. Full article

Background: Monitoring antimicrobial use is crucial for understanding current prescribing practices. Such information helps in establishing stewardship programs for effectively using antimicrobials and combating resistance to them. Objectives: This study describes how antimicrobials are prescribed at the Veterinary Teaching Hospital of the University of Pisa and compares how the internal medicine and intensive care units differ in their usage of antimicrobials. Methods: The study involved cats that were presented in the units in 2021 and 2022. Antimicrobial prescriptions were obtained via the hospital’s management software (OCIROE). Results: In a population of 1164 non-surgical cats with 397 antimicrobials prescribed, the most prescribed ones were amoxicillin–clavulanic acid in the internal medicine unit and ampicillin in the intensive care unit. Twenty-five percent of all antimicrobials were Highest-Priority Critically Important Antimicrobials or Antimicrobial Advice Ad Hoc Expert Group Category B. The oral route was the main route of administration in the internal medicine unit, while parenteral was the most common route used in the intensive care unit. Most antimicrobials were prescribed to treat pathologic conditions affecting the urinary (39%), gastroenteric (21%), respiratory (13%), and integumentary (12%) systems. A diagnosis, accurate dosage, and the use of species-approved medications were recorded in the antimicrobial prescriptions. However, only 11% of these prescriptions were supported by antimicrobial susceptibility tests. Conclusions: These results suggest room for improvement, particularly in increasing the use of antimicrobial susceptibility testing to ensure more targeted antimicrobial therapy. Given the importance of antimicrobial resistance and the One Health approach, the study also highlights the need to consider the broader impact of antimicrobial use in animals, including the potential contribution to resistance in bacteria that affect both animal and human health. Full article

Objective: This study aims to evaluate the correlation of gestational weight gain (GWG) with pregnancy and perinatal outcomes in a cohort of obese women class I-III receiving standard care (SC) or lifestyle intervention (LI). Methods: This is a prospective cohort study including singleton obese women (body mass index, BMI ≥ 30) who delivered between 2016 and 2020. Women exposed to a LI were referred to an obesity weight management ad hoc clinic. Women followed by family centers or private settings represented the SC group. The LI started between the 9 and 12th week, consisting of a low-calorie diet and physical activity program. Pregnancy and perinatal outcomes were prospectively collected. Women included in the SC group were followed, simply checking their pregnancy and health status, providing general recommendations on a healthy lifestyle in pregnancy. GWG was categorized as insufficient, adequate, or excessive according to the Institute of Medicine (IOM). Results: A total of 1874 obese singleton women delivered in the study period. Among them, 565 (30.1%) were included in the LI while 1309 received SC. Women in SC showed a higher rate of GWG out of the IOM recommendations (excessive/insufficient), while women in the LI group showed higher adequate GWG. The small-for-gestational-age (SGA) rate resulted to be higher in the SC group. Once adjusting for age, BMI, country of origin, provider, and gestational hypertension, the risk for SGA was increased by insufficient GWG (OR = 1.25; 95%CI: 1.03–1.59), while it was reduced by LI (OR = 0.67, 95%CI: 0.42–0.98). Conclusions: In a cohort of obese women, the exposure to an LI was associated with more adequate GWG, reduced insufficient weight gain, and a decreased risk of SGA infants. Full article

Hyaluronic acid (HA) is a glycosaminoglycan composed of D-glucuronic acid and N-acetylglucosamine with an up-to-several-million-Daltons chain-length responsible for the lubricating properties of the temporomandibular joint (TMJ) synovial fluid. Arthritis results in the predominance of HA degradation over synthesis leading to temporomandibular disorders (TMDs). TMD injection treatments are divided into HA supplementation and platelet-rich plasma (PRP) inflammation suppression. We questioned whether either approach lubricated the TMJ better and answered it in a two-arm equal-allocation trial with a non-concurrent active treatment control (two groups of 39 patients each). HA statistically significantly improved (p < 0.01) and PRP did not statistically significantly change (0.06 ≤ p ≤ 0.53) articular mobility compared to baselines in 128 TMJs. Statistically significant inter-group discrepancies were observed for abduction (MD = −4.05 mm; SE = 1.08; p = 0.00; d = −0.85) and protrusion (MD = −0.97 mm; SE = 0.43; p = 0.03; d = −0.51) but not for rightward (MD = −0.21; SE = 0.43; p = 0.63; d = −0.11) and leftward (MD = −0.30; SE = 0.42; p = 0.47; d = −0.16) movements. HA supplementation proved superior to PRP autografting in ad hoc TMJ lubrication and hence is more appropriate in hypomobile TMD cases of symptomatic treatment. Full article

The big bud mite Phytoptus avellanae is a resurgent pest of hazelnut, Corylus avellana, causing substantial yields reductions in many productive areas. Mites colonise and develop within healthy buds which become swollen, with subsequent alteration to the plant’s development. To date, there has been limited knowledge on how the cultivar and pest management strategies affect infestations. This study explored these aspects through two ad hoc experiments carried out in central Italy. In the first experiment, the susceptibility of 11 cultivars with different geographic origins was tested in a germplasm hazelnut collection. The second experiment assessed the infestation level in orchards with integrated pest management (IPM) and organic pest management strategies and in a renaturalised environment (a former agricultural area now converted in a natural park). The results showed that the most and the least susceptible cultivars were Tonda Gentile and Nocchione, respectively. No significant differences were found between IPM and organic management, but they were both different to the renaturalised environment. The outcomes of this research can serve as a valuable reference and can be applied to all current or potential hazelnut cultivation areas characterised by the same environmental conditions. Full article

Models and simulations of blood flow in vascular networks are useful to deepen knowledge of cardiovascular diseases. This paper considers a model based on partial differential equations that mimic the dynamics of vascular networks in terms of flow velocities and arterial pressures. Such quantities are found by using ad hoc numerical schemes to examine variations in the pressure and homeostatic conditions of a whole organism. Two different case studies are examined. The former uses 15 arteries—a network that shows the real oscillations in pressures and velocities due to variations in artery volume. The latter focuses on the 55 principal arteries, and blood flows are studied by using a model of a heart valve that opens and closes via the differences in the aortic and left ventricle pressures. This last case confirms the possibility of autonomously regulating blood pressure and velocity in arteries in general and when tilt tests are applied to patients. Full article

Objectives: The main objective of this study is to analyze the relationships between academic performance, physical activity, and academic stress in secondary education students, while the secondary objective is to establish differences by gender in the physical activity and academic stress levels of secondary students based on academic performance. Methods: The sample was composed of students from both sexes who attended public institutions. Data collection was conducted applying an ad hoc questionnaire for academic performance, the PAQ-C questionnaire for physical activity, and the QASSE questionnaire for academic stress. Data analysis was performed using descriptive statistics: Spearman’s correlation coefficient was used for associations, while comparisons were conducted via the Mann–Whitney U test and Kruskal–Wallis H test. Results: The results show that academic stress is negatively correlated with physical activity and academic performance. Men present significantly higher values in physical activity, while women present higher mean values in general academic stress and the academic overload dimension. Lastly, regarding academic performance, significant differences were observed in the family pressure dimension, with students who perform better academically presenting lower mean values in this dimension of academic stress. Conclusions: In conclusion, the more the general academic stress, the lower the physical activity levels and academic performance. In addition, physical activity appears as a potential coping strategy for academic stress, and its influence on academic performance should be further studied in secondary education. Full article