Search Results (59)

This study investigates two novel prefabricated frame joints: prestressed steel sleeve-connected prefabricated reinforced concrete joints (PSFRC) and non-prestressed steel sleeve-connected prefabricated reinforced concrete joints (SSFRC). A total of three PSFRC specimens, four SSFRC specimens, and one cast-in-place joint were designed and fabricated. Seismic performance tests were conducted using different end-plate thicknesses, grout strengths, stiffener configurations, and prestressing tendon configurations. The experimental results showed that all specimens experienced beam end failures, and three failure modes occurred: (1) failure of the end plate of the beam sleeve, (2) failure of the variable cross-section of the prefabricated beam, and (3) failure of prefabricated beams at the connection with the steel sleeves. The load-bearing capacity and initial stiffness of the structure are increased by 35.41% and 32.64%, respectively, by increasing the thickness of the end plate. Specimens utilizing C80 grout exhibited a 39.05% higher load capacity than those with lower-grade materials. Adding stiffening ribs improved the initial stiffness substantially. Specimen XF2 had 219.08% higher initial stiffness than XF1, confirming the efficacy of stiffeners in enhancing joint rigidity. The configuration of the prestressed tendons significantly influenced the load-bearing capacity. Specimen YL2 with symmetrical double tendon bundles demonstrated a 27.27% higher ultimate load capacity than specimen YL1 with single centrally placed tendon bundles. An analytical model to calculate the moment–rotation relationship was established following the evaluation criteria specified in Eurocode 3. The results demonstrated a good agreement, providing empirical references for practical engineering applications. Full article

We study the thermodynamic properties of the generalized non-convex multispecies Curie–Weiss model, where interactions among different types of particles (forming the species) are encoded in a generic matrix. For spins with a generic prior distribution, we compute the thermodynamic limit of the generating functional for the moments of the Boltzmann–Gibbs measure using simple interpolation techniques. For Ising spins, we further analyze the fluctuations of the magnetization in the thermodynamic limit under the Boltzmann–Gibbs measure. It is shown that a central limit theorem (CLT) holds for a rescaled and centered vector of species magnetizations, which converges to either a centered or non-centered multivariate normal distribution, depending on the rate of convergence of the relative sizes of the species. Full article

Introduction: Neonatal sepsis is a severe and life-threatening condition caused by pathogens in the systemic circulation within the first 28 days of life. The classical definition of neonatal sepsis implies positive central cultures, but recent findings discuss culture-negative sepsis (clinical sepsis associated with laboratory findings). Since infected neonates initially express few non-specific clinical signs and there are unreliable biochemical markers to identify sepsis in the early stages, it is essential to improve the accuracy of diagnosis and reduce unnecessary antibiotic exposure. Objective: Our study aims to assess the influence of risk factors and the utility of currently used biomarkers in culture-negative neonatal early-onset sepsis (CN-EOS). Materials and methods: We performed a retrospective study at Bucharest University Hospital, which included 131 preterm and term newborns at risk for EOS admitted in the Neonatal Intensive Care Unit (NICU) over 12 months. The neonates included were classified into two groups: confirmed negative-culture early-onset sepsis (CN-EOS) and suspected early-onset sepsis (S-EOS). Patients from both groups received antibiotic therapy from the first day of life; the type and duration of antibiotic therapy were different in the two groups. For all the patients, we measured C-reactive protein (CRP), procalcitonin (PCT) and white blood count (WBC) at birth and after 72 h, tested blood culture in the first 24 h of life and correlated the results with clinical signs and prenatal risk factors. Categorical variables were presented as frequencies and percentages, while the continuous variables were the mean and the standard deviation. The differences between the continuous variable groups were determined by Student’s t-test or the Mann–Whitney U test, whereas for the categorical variables, the Chi-square test (X²) was employed. The performance of laboratory biomarkers (CRP and PCT) in diagnosing confirmed EOS was calculated. All the tests were statistically significant at a p-value < 0.05. Results: The findings support the significance of low birth weight and gestational age and low Apgar scores as potential indicators for EOS; PROM diagnosed with chorioamnionitis and smoking during the pregnancy were also important predictive risk factors. Respiratory signs, such as apnea and respiratory distress syndrome, were most encountered in the clinical evaluation of infants with CN-EOS. Inflammatory markers were inconsistent in CN-EOS cases, proving that they are not reliable enough for initiating, continuing or stopping antibiotic therapy. Conclusions: Culture-negative neonatal sepsis remains a significant challenge for the neonatologist, since the time elapsed between the moment sepsis is suspected and the initiation of empirical therapy can make the difference between survival and death. Continued efforts are needed to develop more reliable and effective diagnostic tools for timely and appropriate intervention. Full article

The topic of the mosaic patterns of the settlement of ethnic minorities in US cities has been studied in depth. Many works proceed from the optics of studying inequality, which, in the American context, is often explained by overlapping patterns of ethnoracial discrimination. In this regard, groups at the intersection of inequality patterns are of great interest—for example, non-white immigrants and their descendants. This article analyzes the settlement of two such groups—Haitians and Jamaicans—at the state, county, and census tract levels in the two main population centers for the following two groups: New York and Miami metropolitan areas. The authors pose the question of whether Haitians and Jamaicans fundamentally differ from African Americans in terms of settlement patterns and socio-economic status. It is established that these two population groups are highly concentrated on a nationwide scale (in the states of Florida and New York) and in some counties (comprising metropolitan areas of New York and Miami). The authors carried out a spatial correlation (LISA) analysis to identify areas of concentration of Haitians and Jamaicans in the two above-mentioned metropolitan areas. Three distinct Haitian areas, three mixed Haitian/Jamaican, and one distinct Jamaican area are found in New York. In the Miami metropolitan area, three mixed Haitian/Jamaican areas are identified, as well as one Haitian area. Calculation of the Darden–Kamel Composite Socio-Economic Index was used to assess the socio-economic status of these areas and to compare it with that in the areas of concentration of African Americans. The analysis revealed that the areas of concentration of Haitians and Jamaicans are relatively disadvantaged in their socio-economic status, but to a lesser extent than those of African Americans. The study also established the following pattern: in the New York metropolitan area, the higher socio-economic status is a feature of the mixed Haitian/Jamaican areas of concentration in the central city, while in Miami, the higher socio-economic status is observed in the Jamaican areas in the suburbs. Beyond these empirical findings, this article offers a contextual perspective on inequality among non-white migrant groups as they settle near established African American communities. The novelty of our approach to the research problem relates to the idea that communities of African Americans, Haitians, and Jamaicans are quite variable in time and space—in particular, due to the non-simultaneous settlement of these groups in the metropolitan areas under consideration. Our most important conclusion is the discovery of the relationship between the stage of the beginning of the integration of the groups considered into urban communities and their socio-economic status at that moment. The later the group began integration, the fewer discriminatory practices it had to face, which led to a higher socio-economic status. Full article

Schizophrenia is characterized by widespread disruptions in neural connectivity and dynamic modulation. Traditional EEG analyses often rely on static or averaged measures, which may overlook the temporal evolution of neural complexity across cognitive demands. This study employed Higuchi Fractal Dimension, a non-linear measure of signal complexity, to examine the temporal dynamics of EEG activity across five cortical regions (central, frontal, occipital, parietal, and temporal lobes) during an attentional and a memory-based task in individuals diagnosed with schizophrenia and healthy controls. A permutation-based topographic analysis of variance revealed significant differences in neural complexity between tasks and groups. In the control group, results showed a consistent pattern of higher neural complexity during the attentional task across the different brain regions (except during a few moments in the temporal and occipital regions). This pattern of differentiation in complexity between the attentional and memory tasks reflects healthy individuals’ ability to dynamically modulate neural activity based on task-specific requirements. In contrast, the group of patients with schizophrenia exhibited inconsistent patterns of differences in complexity between tasks over time across all neural regions. That is, differences in complexity between tasks varies across time intervals, being sometimes higher in the attentional task and other times higher in the memory task (especially in the central, frontal, and temporal regions). This inconsistent pattern in patients can explain reduced task-specific modulation of EEG complexity in schizophrenia, and suggests a disruption in the modulation of neural activity on function of task demands. These findings underscore the importance of analyzing the temporal dynamics of EEG complexity to capture task-specific neural modulation. Full article

This paper contributes to the literature by demonstrating that behavioral macroeconomic models better explain macroeconomic volatility in emerging economies compared to traditional rational expectations frameworks. We explore behavioral macroeconomics as a foundation for sustainable economic policies by comparing New Keynesian models under rational expectations and behavioral heuristics across multiple economies. The model parameters are estimated using the Generalized Method of Moments (GMM) for rational expectations and the Simulated Method of Moments (SMM) for the behavioral framework, evaluating their ability to replicate empirical second moments of output, inflation, and interest rates. The GMM, suited for linear models, provides analytical solutions, ensuring computational efficiency, while the SMM, designed for non-linear models, enables greater flexibility by generating simulated data and departing from restrictive DSGE assumptions. Our findings reveal that the behavioral model—incorporating heterogeneity, heuristic switching, and bounded rationality—better captures the persistent and volatile macroeconomic conditions observed in Central and Eastern European (CEE) economies. In contrast, rational expectations models perform better in advanced economies, where agents rely more on forward-looking information. These results emphasize the need to integrate behavioral features into macroeconomic modeling to enhance empirical accuracy and inform sustainable monetary policy tailored to diverse economic environments. Full article

Using descriptive and inferential techniques together with simplified metrics derived from the ecological discipline, we offer a long-term investigation of the Environmental Sensitive Area Index (ESAI) as a proxy of land degradation vulnerability in Italy. This assessment was specifically carried out on a decadal scale from 1960 to 2020 at the province (NUTS-3 sensu Eurostat) level and benefited from a short-term forecast for 2030, based on four simplified assumptions grounded on a purely deterministic (‘what … if’) approach. The spatial distribution of the ESAI was investigated at each observation year (1960, 1970, 1980, 1990, 2000, 2010, 2020, 2030) calculating descriptive statistics (central tendency, variability, and distribution shape), deviation from normality, and the increase (or decrease) in diversification in the index scores. Based on nearly 300 thousand observations all over Italy, provinces were considered representative spatial units because they include a relatively broad number of ESAI measures. Assuming a large sample size as a pre-requisite for the stable distribution of the most relevant moments of any statistical distribution—because of the convergence law underlying the central limit theorem—we found that the ESAI scores have increased significantly over time in both central values (i.e., means or medians) and variability across the central tendency (i.e., coefficient of variation). Additionally, ecological metrics reflecting diversification trends in the vulnerability scores delineated a latent shift toward a less diversified (statistical) distribution with a concentration of the observed values toward the highest ESAI scores—possibly reflecting a net increase in the level of soil degradation, at least in some areas. Multiple exploratory techniques (namely, a Principal Component Analysis and a two-way hierarchical clustering) were run on the two-way (data) matrix including distributional metrics (by columns) and temporal observations (by rows). The empirical findings of these techniques delineate the consolidation of worse predisposing conditions to soil degradation in recent times, as reflected in a sudden increase in the ESAI scores—both average and maximum values. These trends underline latent environmental dynamics leading to an early desertification risk, thus representing a valid predictive tool both in the present conditions and in future scenarios. A comprehensive scrutiny of past, present, and future trends in the ESAI scores using mixed (parametric and non-parametric) statistical tools proved to be an original contribution to the study of soil degradation in advanced economies. Full article

Background/Objectives. Obesity, type 2 diabetes (T2D), and Alzheimer’s disease (AD) are pathologies that affect millions of people worldwide. They have no effective therapy and are difficult to prevent and control when they develop. It has been known for many years that these diseases have many pathogenic aspects in common. We highlight in this review that neuroglial cells (astroglia, oligodendroglia, and microglia) play a vital role in the origin, clinical–pathological development, and course of brain neurodegeneration. Moreover, we include the new results of a T2D-AD mouse model (APP+PS1 mice on a high-calorie diet) that we are investigating. Methods. Critical bibliographic revision and biochemical neuropathological study of neuroglia in a T2D-AD model. Results. T2D and AD are not only “connected” by producing complex pathologies in the same individual (obesity, T2D, and AD), but they also have many common pathogenic mechanisms. These include insulin resistance, hyperinsulinemia, hyperglycemia, oxidative stress, mitochondrial dysfunction, and inflammation (both peripheral and central—or neuroinflammation). Cognitive impairment and AD are the maximum exponents of brain neurodegeneration in these pathological processes. both due to the dysfunctions induced by metabolic changes in peripheral tissues and inadequate neurotoxic responses to changes in the brain. In this review, we first analyze the common pathogenic mechanisms of obesity, T2D, and AD (and/or cerebral vascular dementia) that induce transcendental changes and responses in neuroglia. The relationships between T2D and AD discussed mainly focus on neuroglial responses. Next, we present neuroglial changes within their neuropathological context in diverse scenarios: (a) aging involution and neurodegenerative disorders, (b) human obesity and diabetes and obesity/diabetes models, (c) human AD and in AD models, and (d) human AD-T2D and AD-T2D models. An important part of the data presented comes from our own studies on humans and experimental models over the past few years. In the T2D-AD section, we included the results of a T2D-AD mouse model (APP+PS1 mice on a high-calorie diet) that we investigated, which showed that neuroglial dysfunctions (astrocytosis and microgliosis) manifest before the appearance of amyloid neuropathology, and that the amyloid pathology is greater than that presented by mice fed a normal, non-high-caloric diet A broad review is finally included on pharmacological, cellular, genic, and non-pharmacological (especially diet and lifestyle) neuroglial-related treatments, as well as clinical trials in a comparative way between T2D and AD. These neuroglial treatments need to be included in the multimodal/integral treatments of T2D and AD to achieve greater therapeutic efficacy in many millions of patients. Conclusions. Neuroglial alterations (especially in astroglia and microglia, cornerstones of neuroinflammation) are markedly defining brain neurodegeneration in T2D and A, although there are some not significant differences between each of the studied pathologies. Neuroglial therapies are a very important and p. promising tool that are being developed to prevent and/or treat brain dysfunction in T2D-AD. The need for further research in two very different directions is evident: (a) characterization of the phenotypic changes of astrocytes and microglial cells in each region of the brain and in each phase of development of each isolated and associated pathology (single-cell studies are mandatory) to better understand the pathologies and define new therapeutic targets; (b) studying new therapeutic avenues to normalize the function of neuroglial cells (preventing neurotoxic responses and/or reversing them) in these pathologies, as well as the phenotypic characteristics in each moment of the course and place of the neurodegenerative process. Full article

We present a new formulation of the central moment lattice Boltzmann (LB) method based on a minimal continuous Fokker-Planck (FP) kinetic model, originally proposed for stochastic diffusive-drift processes (e.g., Brownian dynamics), by adapting it as a collision model for the continuous Boltzmann equation (CBE) for fluid dynamics. The FP collision model has several desirable properties, including its ability to preserve the quadratic nonlinearity of the CBE, unlike that based on the common Bhatnagar-Gross-Krook model. Rather than using an equivalent Langevin equation as a proxy, we construct our approach by directly matching the changes in different discrete central moments independently supported by the lattice under collision to those given by the CBE under the FP-guided collision model. This can be interpreted as a new path for the collision process in terms of the relaxation of the various central moments to “equilibria”, which we term as the Markovian central moment attractors that depend on the products of the adjacent lower order moments and a diffusion coefficient tensor, thereby involving of a chain of attractors; effectively, the latter are nonlinear functions of not only the hydrodynamic variables, but also the non-conserved moments; the relaxation rates are based on scaling the drift coefficient by the order of the moment involved. The construction of the method in terms of the relevant central moments rather than via the drift and diffusion of the distribution functions directly in the velocity space facilitates its numerical implementation and analysis. We show its consistency to the Navier-Stokes equations via a Chapman-Enskog analysis and elucidate the choice of the diffusion coefficient based on the second order moments in accurately representing flows at relatively low viscosities or high Reynolds numbers. We will demonstrate the accuracy and robustness of our new central moment FP-LB formulation, termed as the FPC-LBM, using the D3Q27 lattice for simulations of a variety of flows, including wall-bounded turbulent flows. We show that the FPC-LBM is more stable than other existing LB schemes based on central moments, while avoiding numerical hyperviscosity effects in flow simulations at relatively very low physical fluid viscosities through a refinement to a model founded on kinetic theory. Full article

Whether fiscal decentralization will lead to agricultural land “non-grainization” has been widely debated in academic circles. How to improve the efficiency of financial support to agriculture and optimize the grain planting structure by clarifying the relationship between central and local powers and responsibilities is the key to ensuring food security. Based on the panel data of 170 cities in China from 2004 to 2017, this paper uses system moment estimation and a threshold effect model to explore the impact of fiscal decentralization on grain planting structure. The results show that (1) fiscal decentralization has a significant negative effect on the share of food crop cultivation in the major grain-producing areas. (2) Taking the wage level, financial support for agriculture, and land finance as the threshold variables, the test finds that there is a threshold effect of fiscal decentralization on the proportion of food crop cultivation, in which land finance dependence and rises in the wage level are conducive to mitigating the negative effect of fiscal decentralization on the proportion of food crop cultivation. (3) For the three major types of food crop varieties, the negative impact of fiscal decentralization on the share of wheat and corn crop cultivation is subject to the threshold effect of wage level, financial support for agriculture, and land finance, while the impact of fiscal decentralization on the share of rice crop cultivation is not significant. The results of the study have an important guiding role for the government to deepen the reform of the tax-sharing system, improve the long-term mechanism of stable growth of financial support for grain, and optimize the layout of the grain industry. Full article

The scientific claim that psychedelic drugs like psilocybin reliably occasion mystical experiences was justified using the Mystical Experiences Questionnaire (the MEQ), a survey first developed in the 1960s by Walter Pahnke using W.T. Stace’s Mysticism and Philosophy. Scholars in Christian mysticism reject the adequacy of Stace’s work for Western theistic mysticism, especially Christianity. One objection is that Stace follows William James in focusing on intense and unusual moments of mystical experience rather than the somewhat more ordinary mystical life. A greater concern is that Stace more adequately reflects non-Western traditions than Western theistic traditions like Christianity. For Stace, mysticism centers on the concept of union with external reality or with the absolute, a union in which the human creature is absorbed or fused. Christian mysticism, by contrast, involves a sense of presence rather than union, experienced in a most intimate relationship as a felt loving closeness with the divine, but not as fusion or absorption into the divine. While love of God is central to the Christian view, it is ignored in Stace and the MEQ30. Finally for Christianity, mysticism is not found in the momentary experience, but in the lifelong interpretation that leads to transformation. Full article

The suboptimal procedure under consideration, based on the MDR-EFE algorithm, provides sequential selection of relevant (in a sense) factors affecting the studied, in general, non-binary random response. The model is not assumed linear, the joint distribution of the factors vector and response is unknown. A set of relevant factors has specified cardinality. It is proved that under certain conditions the mentioned forward selection procedure gives a random set of factors that asymptotically (with probability tending to one as the number of observations grows to infinity) coincides with the “oracle” one. The latter means that the random set, obtained with this algorithm, approximates the features collection that would be identified, if the joint distribution of the features vector and response were known. For this purpose the statistical estimators of the prediction error functional of the studied response are proposed. They involve a new version of regularization. This permits to guarantee not only the central limit theorem for normalized estimators, but also to find the convergence rate of their first two moments to the corresponding moments of the limiting Gaussian variable. Full article

We study matter accretion in a static, axially symmetric and vacuum geometry describing the exterior gravitational field of a black hole mimicker called the $\gamma$ metric. We evaluate the thermal and optical properties of thin accretion disks, including the emission rate, luminosity and shadow, in the $gamma$ spacetime. Also, we explore the radial accretion of polytropic matter fields onto the central source and evaluate the thermal and optical properties of the infalling gas, such as temperature and luminosity. The results are discussed in the context of evaluating the possibility that the true nature of astrophysical black hole candidates may not be a black hole but some exotic compact object possessing a non-vanishing mass quadrupole moment. Full article

Confined walls are popular in areas exposed to seismic action. The advantage of such structures is increased load-bearing capacity, ductility, and energy dissipation. Confined masonry walls are also used to restrain the intensity of cracking and improve load-bearing capacity in areas exposed to seismic action. This paper describes the research on 18 confined walls and presents a comparison with research on unconfined walls (referenced models). The confined models were classified into three series: HOS-C-AAC—without openings and with confining elements around the perimeter; HAS-C1-AAC with a centrally positioned opening and circumferential confinement; and HAS-C2-AAC with a centrally positioned window opening and additional confinement along the vertical edges of the opening. The area of the window opening was 1.5 m². All walls were made of autoclaved aerated concrete (AAC) masonry units of the nominal density class of 600. The walls were tested under initial compressive stresses σ_c = 0.1; 0.75; and 1.0 N/mm². The reference models without confinement (six models of the series HOS-AAC without openings and the series HAS-AAC with openings) were prepared from the same masonry units, had almost the same outer dimensions, and were tested under the same initial compressive stresses σ_c. The analysis was performed for the morphology of cracks, stress values at the moment of cracking and failure, stiffness, and angles of shear strain. The morphology of cracks was found to depend on initial compressive stresses and the presence of an opening. A significant increase in compressive stress leading to cracks and failure stresses was observed with increasing values of initial compressive stresses. As the wall behavior was clearly non-linear, the bilinear relationship described by energy dissipation E, stiffness at the moment of cracking K_cr, and maximum displacement u_u was proposed to be included in the engineering description of the relationship between horizontal load and displacement of confined walls. Confinement along the vertical edges of the opening having an area of 1.5 m² (acc. to EN 1996-1-1) increased the maximum forces P_max by ca. 45% and marginally affected the ductility of the wall when compared to the elements with circumferential confinement. Full article

The negative multinomial distribution appears in many areas of applications such as polarimetric image processing and the analysis of longitudinal count data. In previous studies, general formulas for the falling factorial moments and cumulants of the negative multinomial distribution were obtained. However, despite the availability of the moment generating function, no comprehensive formulas for the moments have been calculated thus far. This paper addresses this gap by presenting general formulas for both central and non-central moments of the negative multinomial distribution. These formulas are expressed in terms of binomial coefficients and Stirling numbers of the second kind. Utilizing these formulas, we provide explicit expressions for all central moments up to the fourth order and all non-central moments up to the eighth order. Full article