Search

This paper addresses the problem of designing secure control for networked multi-agent systems (MASs) under Denial-of-Service (DoS) attacks. We propose a constructive design method based on the interaction topology. The MAS with a non-attack communication topology, modeled by quasi-Abelian Cayley graphs subject to DoS attacks, can be represented as a switched system. Using switching theory, we provide easily implementable sufficient conditions for the networked MAS to remain asymptotically stable despite DoS attacks. Our results are applicable to both continuous-time and discrete-time systems, as well as to discrete-time systems with variable steps or systems that combine discrete and continuous times. [ABSTRACT FROM AUTHOR]

Introduction: Methamphetamine is a highly stimulating psychoactive drug that causes life-threatening addictions and affects millions of people around the world. Its effects on the brain are complex and include disturbances in the neurotransmitter systems and neurotoxicity. There are several known treatment methods, but their effectiveness is moderate. It must be emphasised that no drugs have been approved for treatment. For this reason, there is an urgent need to develop new, effective, and safe treatments for methamphetamine. One of the potential treatments is mindfulness meditation. In recent years, this technique has been researched extensively in the context of many neurological and psychiatric disorders. Methods: This review explores the use of mindfulness in the treatment of methamphetamine addiction. Searches were conducted in the PubMed/Medline, Research Gate, and Cochrane databases. Results: Ten studies were identified that used mindfulness-based interventions in the treatment of methamphetamine addiction. The results show that mindfulness is an effective form of reducing hunger, risk of relapses, stress indicators, depression, and aggression, alone or in combination with transcranial direct current stimulation (tDCS). Mindfulness also improved the cognitive function in addicts. The included studies used only behavioural measures. The potential mechanisms of mindfulness in addiction were explained, and it was proposed that it can induce neuroplasticity, alleviating the symptoms of addiction. Conclusions: Evidence from the studies suggest that mindfulness may be an effective treatment option for methamphetamine addiction, used alone or in combination with tDCS. However, further high-quality research is required to establish the role of this treatment option in this field. The use of neuroimaging and neurophysiological measures is fundamental to understand the mechanisms of mindfulness. [ABSTRACT FROM AUTHOR]

Assessing the long-term stability of abandoned mine workings is a challenging problem in geo-mechanical engineering. There are several factors contributing to the long-term behaviour of excavations. Creep and the gradual deterioration of rocks are, in particular, among the dominant factors affecting the long-term stability of abandoned mine workings. In this paper, the mechanism of post-mining subsidence over old room-and-pillar mine workings is investigated. A case history of post-mining subsidence over Cow Pasture abandoned limestone mine in the West Midlands of the UK is presented. The geological and geotechnical characteristics of the mining site are explained. Empirical and analytical approaches are then used to study the mechanisms of post-mining subsidence. Outcomes of the analyses show that the bearing capacity failure of the roof strata and the gradual punching of pillars into the moisture-sensitive roof layers have been the key mechanisms initiating failure and leading to the formation of post-mining subsidence in the Cow Pasture Mine. [ABSTRACT FROM AUTHOR]

Abstract Anthropogenic activity related to the extraction of gas and oil, raw materials or water pumping leads to slow or rapid ground deformation. The ground motion rate is related to the type of the mined material, geological conditions, mining methods and other factors. Ground subsidence resulting from the collapse of underground post-mining voids occurs gradually. Mining-induced earthquakes and seismic earthquakes are largely unpredictable and have an adverse impact on the local inhabitants and buildings. For this reason, monitoring of this phenomenon is a challenge. The application of interferometric SAR for the evaluation of ground movement has brought satisfactory results over the past twenty years mainly in the regions where no other measurements were conducted during ground subsidence. In this paper we have examined a mining-induced earthquake with a magnitude 4.5 which occurred in an underground copper ore mine in Poland on 29th November 2016 and caused eight fatalities. It also had an impact on ground surface deformation in the vicinity of the mine tailings. An assessment of the earthquake-related impact on surface movement was carried out by Sentinel-1 TOPS time series interferometry. The velocity of ground movement and the scale of the phenomenon were investigated. In addition, the impact of the mining-induced earthquake on Zelazny Most mine tailings site was analyzed. Moreover, the process of dynamic ground compaction was also investigated in detail. Ground movement following the mine earthquake was explored. Two time phases of the movements were determined. The first phase of dynamic ground displacement was rapid and 90% of total ground deformation appeared on the surface within 7 days. The second phase of displacement was a 'vanishing' one; it lasted for approx. 3 weeks and 10% of ground deformation appeared on the surface. The study revealed that the maximum observed ground subsidence did not exceed 9 cm. The presented results contribute to a better understanding of post-earthquake ground deformations in the light of their spatial distribution in time. Highlights • Sentinel-1 interferometry is used to assess subsidence caused by mining-induced earthquake (M W 4.5). • About 92% of total subsidence occurred within 48 h after mining-induced earthquake. • Substantial ground movement stopped 7 days after the earthquake (M W 4.5). • Contribution to studies on ground movements which result from mining-induced earthquake. [ABSTRACT FROM AUTHOR]

This paper deals with control strategies for discrete-time fractional multi-agent systems. By using the discrete fractional order operator we introduce memory effects to the considered problem. Necessary optimality conditions for discrete-time fractional optimal control problems with single- and double-summator dynamics are proved, and simulation results are presented. [ABSTRACT FROM AUTHOR]

In this note we present a counterexample to Theorem 24 in G.S.F. Frederico and D.F.M. Torres (2010) [3] . [ABSTRACT FROM AUTHOR]

The time scale calculus theory can be applicable to any field in which dynamic processes are described by discrete- or continuous-time models. On the other hand, many economic models are dynamic models. Therefore it is natural to relate those two subjects. This work is intended to motivate the use of the calculus of variations and optimal control problems on time scales in the study of economic models. We show that a phenomenon known from the theory of behavioral economics may be described and analyzed by dynamical systems on time scales. [ABSTRACT FROM AUTHOR]

Weather extremes may have strong effects on biodiversity, as known from theoretical and modelling studies. Predicted negative effects of increased weather variation are found only for a few species, mostly plants and birds in empirical studies. Therefore, we investigated correlations between weather variability and patterns in occupancy, local colonisations and local extinctions (metapopulation metrics) across four groups of ectotherms: Odonata, Orthoptera, Lepidoptera, and Reptilia. We analysed data of 134 species on a 1×1 km-grid base, collected in the last 20 years from the Netherlands, combining standardised data and opportunistic data. We applied dynamic site-occupancy models and used the results as input for analyses of (i) trends in distribution patterns, (ii) the effect of temperature on colonisation and persistence probability, and (iii) the effect of years with extreme weather on all the three metapopulation metrics. All groups, except butterflies, showed more positive than negative trends in metapopulation metrics. We did not find evidence that the probability of colonisation or persistence increases with temperature nor that extreme weather events are reflected in higher extinction risks. We could not prove that weather extremes have visible and consistent negative effects on ectothermic species in temperate northern hemisphere. These findings do not confirm the general prediction that increased weather variability imperils biodiversity. We conclude that weather extremes might not be ecologically relevant for the majority of species. Populations might be buffered against weather variation (e.g. by habitat heterogeneity), or other factors might be masking the effects (e.g. availability and quality of habitat). Consequently, we postulate that weather extremes have less, or different, impact in real world metapopulations than theory and models suggest. [ABSTRACT FROM AUTHOR]

Introduction: Patients after SARS-CoV-2 infection frequently face "Post-COVID-19 Syndrome", defined by symptoms that develop during or after COVID-19, continue for more than 12 weeks, and are not explained by an alternative diagnosis. We aimed to evaluate the presence of post-COVID-19 syndrome and its predictors in kidney transplant recipients (KTR) 6 months after the disease. Materials and Methods: A total of 67 KTR (38 m) with a mean age of 53.6 ± 14 years, 7.3 ± 6.4 years post-transplant were included in the cohort longitudinal study. Thirty-nine (58.2%) of them were hospitalized, but not one required invasive ventilation therapy. They were interviewed 6 months after being infected, with a series of standardized questionnaires: a self-reported symptoms questionnaire, the modified British Medical Research Council (mMRC) dyspnea scale, EQ-5D-5L questionnaire, and EQ-VAS scale. Results: Post-COVID-19 syndrome was diagnosed in 70.1% of KTR and 26.9% of them reported at least three persistent symptoms. The most common symptoms were fatigue (43.3%), hair loss (31.3%), memory impairment (11.9%), muscle aches, and headaches (11.9%). Dyspnea with an mMRC scale grade of at least 1 was reported by 34.3% patients vs. 14.9% before infection; 47.8% stated that they still feel worse than before the disease. Mean EQ-VAS scores were 64.83 vs. 73.34 before infection. The persistent symptoms are more frequent in older patients and those with greater comorbidity. Conclusions: Persistent symptoms of post-COVID-19 syndrome are present in the majority of KTR, which highlights the need for long-term follow-up as well as diagnostic and rehabilitation programs. [ABSTRACT FROM AUTHOR]

We extend the second Noether theorem to fractional variational problems which are invariant under infinitesimal transformations that depend upon r arbitrary functions and their fractional derivatives in the sense of Caputo. Our main result is illustrated using the fractional Lagrangian density of the electromagnetic field. [ABSTRACT FROM PUBLISHER]

We extend the second Noether theoremto variational problems on time scales. As corollarieswe obtain the classical second Noether theorem, the second Noether theorem for the h-calculus and the second Noether theorem for the q-calculus. [ABSTRACT FROM AUTHOR]

Abstract: We study operators that are generalizations of the classical Riemann–Liouville fractional integral, and of the Riemann–Liouville and Caputo fractional derivatives. A useful formula relating the generalized fractional derivatives is proved, as well as three relations of fractional integration by parts that change the parameter set of the given operator into its dual. Such results are explored in the context of dynamic optimization, by considering problems of the calculus of variations with general fractional operators. Necessary optimality conditions of Euler–Lagrange type and natural boundary conditions for unconstrained and constrained problems are investigated. Interesting results are obtained even in the particular case when the generalized operators are reduced to be the standard fractional derivatives in the sense of Riemann–Liouville or Caputo. As an application we provide a class of variational problems with an arbitrary kernel that give answer to the important coherence embedding problem. Illustrative optimization problems are considered. [Copyright &y& Elsevier]

Abstract: This paper presents the Euler–Lagrange equations for fractional variational problems with multiple integrals. The fractional Noether-type theorem for conservative and nonconservative generalized physical systems is proved. Our approach uses well-known notion of the Riemann–Liouville fractional derivative. [Copyright &y& Elsevier]

Abstract: We introduce differential, integral, and variational delta embeddings. We prove that the integral delta embedding of the Euler–Lagrange equations and the variational delta embedding coincide on an arbitrary time scale. In particular, a new coherent embedding for the discrete calculus of variations that is compatible with the least-action principle is obtained. [Copyright &y& Elsevier]

We study fractional variational problems in terms of a generalized fractional integral with Lagrangians depending on classical derivatives, generalized fractional integrals and derivatives. We obtain necessary optimality conditions for the basic and isoperimetric problems, as well as natural boundary conditions for free-boundary value problems. The fractional action-like variational approach (FALVA) is extended and some applications to physics discussed. [ABSTRACT FROM AUTHOR]

We present a unified treatment to control problems on an arbitrary time scale by introducing the study of forward-backward optimal control problems. Necessary optimality conditions for delta-nabla isoperimetric problems are proved, and previous results in the literature are obtained as particular cases. As an application of the results of the paper we give necessary and sufficient Pareto optimality conditions for delta-nabla bi-objective optimal control problems. [ABSTRACT FROM PUBLISHER]

In this work we study a quasilinear system of equations on time scales. Using the Krasnoselskii fixed-point theorem, sufficient conditions are given for the existence of positive solutions. [ABSTRACT FROM AUTHOR]

Abstract: We prove the Euler–Lagrange delta-differential equations for problems of the calculus of variations on arbitrary time scales with delta-integral functionals depending on higher-order delta derivatives. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents the necessary and sufficient optimality conditions for problems of the fractional calculus of variations with a Lagrangian depending on the free end-points. The fractional derivatives are defined in the sense of Caputo. [Copyright &y& Elsevier]

We introduce the notion of strong local minimizer for the problems of the calculus of variations on time scales. Simple examples show that on a time scale a weak minimum is not necessarily a strong minimum. A time scale form of the Weierstrass necessary optimality condition is proved, which enables to include and generalize in the same result both continuous-time and discrete-time conditions [ABSTRACT FROM AUTHOR]

The presented research aimed to evaluate the spatio-temporal distribution of ground movements caused by groundwater head changes induced by mining. The research was carried out in the area of one of the copper ore and anhydrite mines in Poland. To determine ground movements, classical surveying results and the persistent scatter Satellite Radar Interferometry (PSInSAR) method were applied. The mining operation triggered significant subsidence, reaching 1.4 m in the years 1944–2015. However, subsidence caused by groundwater pumping was about 0.3 m. After mine closure, an ongoing groundwater rebound was observed. Hence, land uplift occurred, reaching no more than 29 mm/y. The main part of the investigation concerned developing a novel method for uplift prediction. Therefore, an attempt was made to comparatively analyze the dynamics of ground movements correlated with the mine life and hydrogeological condition. These analyses allowed the time factor for the modeling of land uplift to be determined. The investigation also revealed that in the next six years, the uplift will reach up to 12 mm/y. The developed methodology could be applied in any post-mining area where groundwater-rebound-related uplift is observed. [ABSTRACT FROM AUTHOR]

Earthquake occurrence is usually unpredictable apart from sites in the vicinity of volcanoes. It is not easy to measure displacements caused by seismic phenomena using classical geodetic methods, which are based on point survey. Therefore, the surveying of ground movements caused by seismic events should be carried out continuously. Nowadays, remote sensing data and InSAR are often applied to monitor ground displacements in areas affected by seismicity. The effects of severe nearby mining-induced earthquakes have been discussed in the paper. The earthquakes occurred in 2017 and had a magnitude of 4.7 and 4.8. The distance between the epicenters of the mining-induced earthquakes was around 1.6 km. The aim of the investigation has been to analyze the spatio-temporal distribution of ground movements caused by the two tremors using the InSAR technique. Superposition of surface displacement has been studied in time and space. The main scientific aim has been to prove that in the areas where high-energy tremors occur, ground movements overlap. Due to proximity between the epicenters, the mining-induced earthquakes caused the formation of a large subsidence trough with the dimension of approximately 1.2 km × 4.2 km and total subsidence of ca. 116 mm. Two-time phases of subsidence were determined with temporal overlapping. The subsidence analysis has enhanced the cognition of the impact of mining-induced seismicity on the kinematics of surface changes. Moreover, the present work supports the thesis that InSAR is a valuable and adequately accurate technique to monitor ground displacements caused by mining induced earthquakes. [ABSTRACT FROM AUTHOR]

• Sinkholes pose significant hazards in populated areas. • We investigated early detection of sinkholes using Persistent Scatterer (PS) Interferometry. • Accelerating subsidence may indicate sinkhole occurence. Unexpectedly occurring sinkholes caused by shallow submerged voids are one of the key problems of intensively built-up post-mining areas. Five percent of Poland's territory is still under the influence of post-mining deformation. Impending sinkholes, which tend to develop randomly over very large areas, cannot be detected by using traditional geophysical methods. Moreover, geodetic measurement methods like Global Positioning System (GPS) analyses, tachymetry, laser scanning, or photogrammetry may be useful only for the registration of the dimensions and locations of sinkholes that have already occurred. Here, we investigate an area in Upper Silesia, Poland, where 345 sinkholes were recorded over a period of more than 20 years (1992–2013). Most of the events occurred in intensively built-up areas, and thus, these sinkholes posed a direct threat to the population. In the test area, 11 sinkholes were detected with a maximum depth of 16 m and maximum dimension of 25 m. The root cause of sinkhole formation was the collapse of post-mining shallow voids. We used satellite radar technology to detect and monitor ground movements potentially associated with the impending sinkholes. The findings showed that the application of Persistent Scatterer Interferometry can support the identification of zones where sinkholes will occur, given adequate spatio-temporal sampling. A stack of Envisat Synthetic Aperture Radar (SAR) images acquired between March 2003 and August 2010 was used in the analysis, and the results confirmed that precursory ground movements were detectable at an early stage of sinkhole development. The land subsidence rate observed prior to sinkhole collapse was not constant in time. Accelerated ground movements within 100 m of an observed sinkhole were detected. We conclude that satellite measurements may provide significant support in the early identification of areas prone to sinkhole occurrence. [ABSTRACT FROM AUTHOR]

Oxide Dispersion Strengthened (ODS) ferritic steels are promising materials for the nuclear power sector. This paper presents the results of a study on the sintering process using the Spark Plasma Sintering (SPS) technique, focusing on ODS ferritic steel powders with different contents (0.3 and 0.6 vol.%) of Y2O3. The novelty lies in the analysis of the effect of pre-annealing treatment on powders previously prepared by mechanical alloying on the microstructure, mechanical, and thermal properties of the sinters. Using the SPS method, it was possible to obtain well-densified sinters with a relative density above 98%. Pre-annealing the powders resulted in an increase in the relative density of the sinters and a slight increase in their thermal conductivity. The use of low electron energies during SEM analysis allowed for a fairly good visualization of the reinforcing oxides uniformly dispersed in the matrix. Analysis of the Mössbauer spectroscopy results revealed that pre-annealing induces local atomic rearrangements within the solid solution. In addition, there was an additional spectral component, indicating the formation of a Cr-based paramagnetic phase. The ODS material with a higher Y2O3 content showed increased Vickers hardness values, as well as increased Young's modulus and nanohardness, as determined by nanoindentation tests. [ABSTRACT FROM AUTHOR]

Background: Among many possible variables that can be associated with gratitude, researchers list personality traits. Considering that these relationships are not always consistent, the first purpose of the present study was to verify how the Big Five factors connect to dispositional gratitude in a sample of Polish participants. The second purpose was to assess the unique contribution of personality traits on gratitude with multiple regression analyses. Moreover, because much remains to be learned about whether these associations are indirectly influenced by different personal or social variables, the third goal was to explore the role of emotional intelligence as a potential mediational mechanism implicated in the relationship between personality traits and gratitude. Participants, Methods and Data Collection: The sample consisted of 712 Polish respondents who were aged between 17 and 88. Most of them were women (64.3%). They answered questionnaires concerning their personality traits, emotional intelligence, and gratitude. The research was conducted using the paper-and-pencil method through convenience sampling. Results: The results showed that both gratitude and emotional intelligence correlated positively and significantly with extraversion, openness to experience, agreeableness, and conscientiousness. Gratitude and emotional intelligence correlated negatively and significantly with neuroticism. The personality predictor of gratitude with the highest and positive standardized regression value was agreeableness, followed by openness to experience and extraversion. Neuroticism had a negative impact on gratitude. Conscientiousness was the only statistically insignificant predictor in the tested multiple regression model. Moreover, emotional intelligence mediated the relationship between four dimensions of personality (extraversion, openness to experience, agreeableness, and conscientiousness) and gratitude and acted as a suppressor between neuroticism and gratitude. Conclusion: The current study broadens our comprehension of the interaction among personality traits, emotional intelligence, and a grateful disposition. Moreover, it imparts a noteworthy foundation not only for the mediatory role of emotional intelligence between four dimensions of personality and gratitude but also for its suppressor effect between neuroticism and being grateful. [ABSTRACT FROM AUTHOR]

Abstract: This article is devoted to the regular fractional Sturm–Liouville eigenvalue problem. By applying the methods of fractional variational analysis, we prove the existence of a countable set of orthogonal solutions and corresponding eigenvalues. Moreover, we formulate two results showing that the lowest eigenvalue is the minimum value for a certain variational functional. [Copyright &y& Elsevier]

Oil productions can result in pore pressure drop in the reservoir, generating an increase in effective stress and leading to reservoir compaction. The compaction in the subsurface reservoir translates to the earth's surface, which is manifested as a loss of elevation (land subsidence), causing damages to oil production facilities and surface infrastructures. The Liaohe oilfield, located in Liaohe River Delta (LRD), northeast of China, is one of the most significant subsidence areas in China as a direct consequence of oil extraction from the reservoir. Previous studies carried out in this area assumed the oil production-induced displacement retrieved from Interferometric Synthetic Aperture Radar (InSAR) corresponds only to vertical deformation. In this work, for the first time, we proposed a method to retrieve the full three-dimensional (3D) displacement field over the oilfield. We retrieved the vertical and east-west displacement components by combining the multiple-geometry InSAR line-of-sight (LOS) observations and retrieved the north-south component based on the assumption of a physical relationship between the horizontal and vertical displacement. Two ascending and two descending datasets from Sentinel-1 satellite covering the area were processed by an InSAR time series analysis over the 2017 to 2021 period, providing consistent displacement rate maps and displacement time series in the LOS direction. Spatial local-scale land subsidence was found in several producing fields over the deltaic region, including Shuguang, Huanxiling, and Jinzhou oilfields. The 3D displacement decomposition was then conducted in Shuguang oilfield. The derived 3D displacement field exhibit a circular subsidence bowl with a maximum subsiding rate reaching 212 mm/year, accompanied by a centripetal pattern of horizontal displacements with maximum rates up to 50–60 mm/year moving towards the subsidence center. The retrieved 3D displacements are in good agreement with predictions from the geomechanical modeling by assuming a disk-shaped reservoir subject to a uniform reduction in pore fluid pressure. Finally, we show the importance of knowing both the vertical and horizontal displacement in characterizing the lateral boundary of the subsurface reservoir. [ABSTRACT FROM AUTHOR]

The interaction between climate change and habitat fragmentation has been presented as a deadly anthropogenic cocktail. We cannot stop climate change, but it is within our circle of influence as ecologists to suggest landscape adaptation. Detailed population models that take into account climate change are considerably needed. We explore a detailed individual-based spatially explicit metapopulation model of a univoltine butterfly species where all processes are affected by daily weather, using historical daily weather data and future daily projections as input, in order to examine responses of a butterfly population in landscapes under various states of fragmentation and two climate change scenarios. This tool is used to investigate how landscapes could be adapted to compensate for possible negative impacts of climate change on population performance. We find that our model butterfly metapopulation was not only able to escape adverse conditions in summer by phenological shifts, but even to benefit from climatic warming. Varying either the amount of suitable habitat or patch size revealed a sharp threshold in population viability. In this particular case, however, the threshold was not affected by climate change and climate-dependent landscape adaptation was not required. The model presented here can be adapted for other species and applied to investigate scenarios for landscape adaptation. [Copyright &y& Elsevier]

In this paper, we present a new series of alkali‐free bioactive glasses (BG) based on FastOs® composition (38.49 SiO2 – 36.07 CaO – 19.24 MgO – 5.61 P2O5 – 0.59 CaF2, expressed in mol %), which was modified by partially replacing silicon dioxide network‐former with boron trioxide network‐former, utilizing calcium oxide as a charge compensator. The main objective of this study was to obtain a new family of bioactive glasses suitable for the fabrication of glass fibers. The BGs were prepared by melt quenching technique and their structural and thermal properties were determined. Glass rods were used to obtain fibers by the classic drawing technique. The bioactivity of the fibers was subsequently assessed through immersion tests in simulated body fluid (SBF) to establish their ability to form hydroxyl carbonated (HCA) apatite onto their surfaces. Glasses with moderate substitution of SiO2 with B2O3 exhibited enhanced thermal properties, allowing to significantly suppress the crystallization trend, and favoring to draw the fibers. The structure of the studied glasses was obtained by NMR spectroscopy. The structure‐property correlations were established by their relationship to the configurational entropy. Smaller amounts of substitution resulted in larger entropy of the glasses. Moreover the SBF tests revealed an extensive formation of HCA, comparable to the parent FastOs®BG composition, which assures fast bonding to the bone. Thus, presented glass fibers may be considered as promising materials for wool‐like bone implants or as reinforcing constituent of biopolymer matrix composites. [ABSTRACT FROM AUTHOR]

Does the way we think or feel about ourselves have an impact on our anger-based reactions? Is the direction and strength of this relationship direct, or affected by other factors as well? Given that there is a lack of research on the loss of self-dignity and anger, the first aim of the present study consisted in examining whether or not there is a connection between both variables, with particular emphasis on early adulthood. The second purpose was to explore the moderating role of religiosity on the relationship between loss of self-dignity and anger. Methods: Data were gathered from 462 participants aged 18 to 35. The main methods applied were the Questionnaire of Sense of Self-Dignity, Buss–Perry Aggression Questionnaire, and Religious Meaning System Questionnaire. The results show a statistically significant positive correlation between loss of self-dignity and anger, a negative correlation between religiosity and anger, and no significant association between the loss of self-dignity and religiosity. However, all other dimensions of the sense of self-dignity correlated positively with religiosity. Our findings also confirm that the level of anger resulting from the loss of self-dignity is significantly lower as the level of religiosity increases. Such outcomes seem to support the conception that religiosity may act as a protective factor between the risk (loss of self-dignity) and the outcome factor (anger). [ABSTRACT FROM AUTHOR]

The article describes a systematic investigation of the effects of an aqueous NaOH treatment of 3D printed poly(lactic acid) (PLA) scaffolds for surface activation. The PLA surface undergoes several morphology changes and after an initial surface roughening, the surface becomes smoother again before the material dissolves. Erosion rates and surface morphologies can be controlled by the treatment. At the same time, the bulk mechanical properties of the treated materials remain unaltered. This indicates that NaOH treatment of 3D printed PLA scaffolds is a simple, yet viable strategy for surface activation without compromising the mechanical stability of PLA scaffolds. [ABSTRACT FROM AUTHOR]

Natural killer (NK) cells make vital contributions to the immune system and the reproductive system. Notably, NK cells of donor origin can recognize and kill residual leukaemic cells and cure malignant patients in hematopoietic stem cell (HSC) transplant setting. NK cell function is regulated by KIRs that recognize cognate HLA class I molecules on target cells, depending on their amino acid residues. In review, we addressed the question of binding capacity and avidity of HLA class I molecules to different killer cell immunoglobulin‐like receptors (KIRs) depending on all interacting amino acid residues both on HLA and KIR side. We searched PubMed database and analysed available HLA:KIR crystallographic data for amino acid residues in HLA molecules, those physically involved in binding KIRs (termed here the "entire KIR interface"). Within entire KIR interface, we selected five functional sequence motifs (14–19, 66–76, 77–84, 88–92 and 142–151) and classified them according to the conservation of their amino acid sequences among 8,942 HLA class I molecules. Although some conserved amino acid motifs were shared by different groups of KIR ligands, the HLA motif combinations were exclusive for the ligand groups. In 135 common HLA class I molecules with known HLA:KIR recognition, we found 54 combinations of five motifs in each of the KIR‐binding interfaces (C1, C2, Bw4, A3/11) and conserved non‐KIR‐binding interfaces. Based on the entire KIR interface, this analysis allowed to classify 8,942 HLA class I molecules into KIR specificity groups. This functional and evolutionary classification of entire KIR interfaces provides a tool for unambiguously predicting HLA:KIR interactions for common and those HLA molecules that have not yet been functionally tested. Considering the entire KIR interface in HLA class I molecules, functional interactions of HLA and KIR can be predicted in immune responses, reproduction and allotransplantation. Further functional studies are needed on the HLA:KIR interaction variations caused by the repertoires of peptides presented by HLA molecules and KIR polymorphisms at allelic level. [ABSTRACT FROM AUTHOR]

This article describes the synthesis of anionic polymer brushes and their mineralization with calcium phosphate. The brushes are based on poly(3-sulfopropyl methacrylate potassium salt) providing a highly charged polymer brush surface. Homogeneous brushes with reproducible thicknesses are obtained via surface-initiated atom transfer radical polymerization. Mineralization with doubly concentrated simulated body fluid yields polymer/inorganic hybrid films containing AB-Type carbonated hydroxyapatite (CHAP), a material resembling the inorganic component of bone. Moreover, growth experiments using Dictyostelium discoideum amoebae demonstrate that the mineral-free and the mineral-containing polymer brushes have a good biocompatibility suggesting their use as biocompatible surfaces in implantology or related fields. [ABSTRACT FROM AUTHOR]

Adsorption of bovine serum albumin (BSA) on the surface of SiO 2 was investigated mainly using quartz crystal microbalance (QCM) with energy dissipation mode. BSA adsorption kinetics and coverage were determined as a function of pH of the solution with the ionic strength of 1 × 10 −2 M. The maximum coverage was obtained in the pH range 4.5–5.4, near the protein isoelectric point. For pH larger than 5.4 and smaller than 4.5 a monotonic decrease of the adsorbed mass was observed. The images obtained using atomic force microscopy (AFM) method revealed various BSA structures depending on the pH at which they were adsorbed. The identified conformations were assigned to the compact triangular form with an effective length L ef = 8.3 nm and the elongated one with length L ef = 26.7 nm. The dependence between the structure of the protein layers formed on the surface and BSA conformations in solution was additionally followed by contact angle (CA) measurements. It turned out that CA values are very sensitive to the structure of BSA monolayers formed on the silica surface. Comparison of QCM and AFM data with those obtained by other indirect methods (CA) additionally enabled interpretation of the dependence of BSA adsorption on the pH of the solution. The obtained results confirmed the significant role of the highly anisotropic surface charge distribution of BSA molecules on the process of their adsorption. [ABSTRACT FROM AUTHOR]

Ultrathin “one-component” multilayer polymeric films for potential biomedical applications were designed based on polyvinyl alcohol,—a non-toxic, fully degradable synthetic polymer. Good uniformity of the obtained film and adequate adsorption properties of the polymeric layers were achieved by functional modification of the polymer, which involved synthesis of cationic and anionic derivatives. Synthesized polymers were characterized by FTIR, NMR spectroscopy, dynamic light scattering measurements and elemental analysis. The layer by layer assembly technique was used to build up a multilayer film and this process was followed using UV–Vis spectroscopy and ellipsometry. The morphology and thickness of the obtained multilayered film material was evaluated by atomic force microscopy (AFM). Preliminary studies on the application of the obtained multilayer film for coating of liposomal nanocarriers containing phenytoin, an antiarrhythmic drug, were performed. The coating effectively stabilizes liposomes and the effect increases with an increasing number of deposited layers until the polymeric film reaches the optimal thickness. The obtained release profiles suggest that bilayer-coated liposomes release phenytoin less rapidly than uncoated ones. The cytotoxicity studies performed for all obtained nanocarriers confirmed that none of them has negative effect on cell viability. All of the performed experiments suggest that liposomes coated with ultrathin film obtained from PVA derivatives can be attractive drug nanocarriers. [ABSTRACT FROM AUTHOR]

Population viability analyses (PVAs) contribute to conservation theory, policy, and management. Most PVAs focus on single species within a given landscape and address a specific problem. This specificity often is reflected in the organization of published PVA descriptions. Many lack structure, making them difficult to understand, assess, repeat, or use for drawing generalizations across PVA studies. In an assessment comparing published PVAs and existing guidelines, we found that model selection was rarely justified; important parameters remained neglected or their implementation was described vaguely; limited details were given on parameter ranges, sensitivity analysis, and scenarios; and results were often reported too inconsistently to enable repeatability and comparability. Although many guidelines exist on how to design and implement reliable PVAs and standards exist for documenting and communicating ecological models in general, there is a lack of organized guidelines for designing, applying, and communicating PVAs that account for their diversity of structures and contents. To fill this gap, we integrated published guidelines and recommendations for PVA design and application, protocols for documenting ecological models in general and individual-based models in particular, and our collective experience in developing, applying, and reviewing PVAs. We devised a comprehensive protocol for the design, application, and communication of PVAs (DAC-PVA), which has 3 primary elements. The first defines what a useful PVA is; the second element provides a workflow for the design and application of a useful PVA and highlights important aspects that need to be considered during these processes; and the third element focuses on communication of PVAs to ensure clarity, comprehensiveness, repeatability, and comparability. Thereby, DAC-PVA should strengthen the credibility and relevance of PVAs for policy and management, and improve the capacity to generalize PVA findings across studies. [ABSTRACT FROM AUTHOR]

This paper studies the leader-following consensus problem in continuous-time multi-agent networks with communications/updates occurring only at random times. The time between two consecutive controller updates is exponentially distributed. Some sufficient conditions are derived to design the control law that ensures the leader-following consensus is asymptotically reached (in the sense of the expected value of a stochastic process). The numerical examples are worked out to demonstrate the effectiveness of our theoretical results. [ABSTRACT FROM AUTHOR]

A leader-following consensus for Caputo fractional multi-agent systems with nonlinear intrinsic dynamics is investigated. The second Lyapunov method is used to design a control protocol ensuring a consensus for two types of multi-agent systems. Contrary to the previous studies on leader-following consensus, the investigation covers systems with bounded and unbounded time-dependent Lipschitz coefficients in the intrinsic dynamics. Moreover, coupling strength describing the interactions between agents is considered to be a function of time. [ABSTRACT FROM AUTHOR]