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1.
Heliyon ; 10(15): e35328, 2024 Aug 15.
Article in English | MEDLINE | ID: mdl-39170358

ABSTRACT

In complex systems, single micro/nanorobots encounter challenges related to limited loading capacity and navigation, hindering their effective utilization in targeted therapy and drug delivery. To solve these challenges, this paper explores potential field mechanisms as a means to simulate natural collective behavior. This approach aims to enhance the navigation and efficiency of micro/nanorobots in high-demand therapeutic areas. The mechanism enables micro/nanorobots to dynamically adapt to environmental gradients, minimizing off-target effects while maximizing therapeutic efficacy and enhancing robustness through redundancy. Additionally, this study introduces innovative distributed learning and cooperative control strategies. Each micro/nanorobot updates its navigation strategy through local interactions and influences with the dynamic environment. This allows micro/nanorobots to share information and improve their navigation toward therapeutic targets. The simulation results demonstrate that collective behavior and potential field mechanisms can enhance the precision and efficiency of targeted therapy and drug delivery in dynamically changing environments. In conclusion, the proposed approach can improve the limitations of single micro/nanobot, offering new possibilities for the development of advanced therapeutics and drug delivery systems.

2.
Neuroscience ; 557: 116-123, 2024 Aug 13.
Article in English | MEDLINE | ID: mdl-39142623

ABSTRACT

In conscious states, the electrodynamics of the cortex are reported to work near a critical point or phase transition of chaotic dynamics, known as the edge-of-chaos, representing a boundary between stability and chaos. Transitions away from this boundary disrupt cortical information processing and induce a loss of consciousness. The entropy of the electroencephalogram (EEG) is known to decrease as the level of anesthesia deepens. However, whether the chaotic dynamics of electroencephalographic activity shift from this boundary to the side of stability or the side of chaotic enhancement during anesthesia-induced loss of consciousness remains poorly understood. We investigated the chaotic properties of EEGs at two different depths of clinical anesthesia using the maximum Lyapunov exponent, which is mathematically regarded as a formal measure of chaotic nature, using the Rosenstein algorithm. In 14 adult patients, 12 s of electroencephalographic signals were selected during two depths of clinical anesthesia (sevoflurane concentration 2% as relatively deep anesthesia, sevoflurane concentration 0.6% as relatively shallow anesthesia). Lyapunov exponents, correlation dimensions and approximate entropy were calculated from these electroencephalographic signals. As a result, maximum Lyapunov exponent was generally positive during sevoflurane anesthesia, and both maximum Lyapunov exponents and correlation dimensions were significantly greater during deep anesthesia than during shallow anesthesia despite reductions in approximate entropy. The chaotic nature of the EEG might be increased at clinically deeper inhalational anesthesia, despite the decrease in randomness as reflected in the decreased entropy, suggesting a shift to the side of chaotic enhancement under anesthesia.

3.
J Clin Med ; 13(14)2024 Jul 18.
Article in English | MEDLINE | ID: mdl-39064242

ABSTRACT

Dementia is a highly prevalent condition with devastating clinical and socioeconomic sequela. It is expected to triple in prevalence by 2050. No treatment is currently known to be effective. Symptomatic late-onset dementia and predementia (SLODP) affects 95% of patients with the syndrome. In contrast to trials of pharmacological prevention, no treatment is suggested to remediate or cure these symptomatic patients. SLODP but not young onset dementia is intensely associated with multimorbidity (MUM), including brain-perturbating conditions (BPCs). Recent studies showed that MUM/BPCs have a major role in the pathogenesis of SLODP. Fortunately, most MUM/BPCs are medically treatable, and thus, their treatment may modify and improve SLODP, relieving suffering and reducing its clinical and socioeconomic threats. Regrettably, the complex system features of SLODP impede the diagnosis and treatment of the potentially remediable conditions (PRCs) associated with them, mainly due to failure of pattern recognition and a flawed diagnostic workup. We suggest incorporating two SLODP-specific conceptual themes into the diagnostic workup: MUM/BPC and multilevel phenomenological themes. By doing so, we were able to improve the diagnostic accuracy of SLODP components and optimize detecting and favorably treating PRCs. These revolutionary concepts and their implications for remediability and other parameters are discussed in the paper.

4.
Methods Mol Biol ; 2811: 1-26, 2024.
Article in English | MEDLINE | ID: mdl-39037646

ABSTRACT

This chapter summarizes clinical evidence on tumor dormancy, with a special focus on our research supporting the role of dormancy both in local and distant recurrence of breast cancer following mastectomy. Starting from these premises, we propose a model of neoplastic development that allows us to elucidate several relevant clinical phenomena, including the mammographic paradox, the significance of ipsilateral breast tumor recurrence after conservative surgery, and the effect of surgeries performed after the removal of the primary. We will discuss the biological implications of the dormancy-based model, which are at odds with Somatic Mutation Theory. We will then review new models, alternatives to the Somatic Mutation Theory, for cancer development, with special emphasis on the Dynamic System Theory and the originality of its conceptual approach. Finally, we will put particular emphasis on the view of cancer development as a tissue-level process. We believe that this will help harmonize the molecular biology research with the new conceptual approach and bridge the knowledge gap on dormancy between bench and bedside.


Subject(s)
Breast Neoplasms , Neoplasm Recurrence, Local , Humans , Breast Neoplasms/pathology , Breast Neoplasms/genetics , Female , Mastectomy , Mutation
5.
Int J Biol Macromol ; 272(Pt 2): 132773, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38823746

ABSTRACT

The structure and physicochemical properties of the complex system of peanut protein and gluten with different concentrations (0 %, 0.5 %, 1 %, and 2 %) of carboxymethyl cellulose (CMC) or sodium alginate (SA) under high-moisture extrusion were studied. The water absorption index and low-field nuclear magnetic resonance showed that adding 0.5 % SA could significantly improve the water uniformity of peanut protein extrudates, while the increase in water absorption was not significant. The texture properties showed that adding CMC or SA increased the hardness, vertical shearing force, and parallel shearing force of the system. Furthermore, adding 0.5 % SA increased approximately 33 % and 75.2 % of the tensile distance and strength of the system, respectively. The secondary structure showed that CMC or SA decreased the proportion of α-helix, ß-turn, and random coil, while increased ß-sheet proportion. The results of hydrophobicity, unextractable protein, and endogenous fluorescence revealed that CMC and SA reduced the surface hydrophobicity of the system and caused fluorescence quenching in the system. Additionally, it was found that CMC generally increased the free sulfhydryl group content, while SA exhibited the opposite effect.


Subject(s)
Arachis , Colloids , Glutens , Plant Proteins , Polysaccharides , Triticum , Glutens/chemistry , Arachis/chemistry , Colloids/chemistry , Plant Proteins/chemistry , Polysaccharides/chemistry , Polysaccharides/pharmacology , Triticum/chemistry , Chemical Phenomena , Water/chemistry , Hydrophobic and Hydrophilic Interactions , Carboxymethylcellulose Sodium/chemistry , Tensile Strength , Alginates/chemistry , Alginates/pharmacology
6.
J Health Organ Manag ; ahead-of-print(ahead-of-print)2024 May 24.
Article in English | MEDLINE | ID: mdl-38785038

ABSTRACT

PURPOSE: In the past few decades, performance measuring systems have become important managerial tools for healthcare organizations. Healthcare performance metrics are a useful tool in understanding how healthcare organizations achieve their goals while satisfying the needs of their patients and conforming to national and international standards. Various efforts have been made to assess healthcare performance. Most of these measures are focused on a single perspective or developed by a single source to meet management and strategic objectives on time. DESIGN/METHODOLOGY/APPROACH: We develop a review of the literature to shed light on the measures used to assess performance in the healthcare sector at various points in time, as well as to establish a thorough understanding of healthcare performance measurement. FINDINGS: Developing real-time digital traceability of metrics and an integrative perspective that increases the actionability of information acquired is an attractive potential made possible by the introduction of new technologies and the digitization of data. ORIGINALITY/VALUE: We conclude that a proper measurement system should be one to combine patient, physician, non-medical staff and system perspective, which will further facilitate the assessment of healthcare performance and the comparative function.


Subject(s)
Delivery of Health Care , Humans , Delivery of Health Care/organization & administration , Quality Indicators, Health Care
7.
Trends Neurosci ; 47(7): 506-521, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38806296

ABSTRACT

Concepts from network science and graph theory, including the framework of network motifs, have been frequently applied in studying neuronal networks and other biological complex systems. Network-based approaches can also be used to study the functions of individual neurons, where cellular elements such as ion channels and membrane voltage are conceptualized as nodes within a network, and their interactions are denoted by edges. Network motifs in this context provide functional building blocks that help to illuminate the principles of cellular neurophysiology. In this review we build a case that network motifs operating within neurons provide tools for defining the functional architecture of single-neuron physiology and neuronal adaptations. We highlight the presence of such computational motifs in the cellular mechanisms underlying action potential generation, neuronal oscillations, dendritic integration, and neuronal plasticity. Future work applying the network motifs perspective may help to decipher the functional complexities of neurons and their adaptation during health and disease.


Subject(s)
Nerve Net , Neurons , Animals , Humans , Neurons/physiology , Nerve Net/physiology , Models, Neurological , Neuronal Plasticity/physiology , Action Potentials/physiology
8.
Entropy (Basel) ; 26(4)2024 Apr 12.
Article in English | MEDLINE | ID: mdl-38667884

ABSTRACT

Complex systems are prevalent in various disciplines encompassing the natural and social sciences, such as physics, biology, economics, and sociology. Leveraging data science techniques, particularly those rooted in artificial intelligence and machine learning, offers a promising avenue for comprehending the intricacies of complex systems without necessitating detailed knowledge of underlying dynamics. In this paper, we demonstrate that multiscale entropy (MSE) is pivotal in describing the steady state of complex systems. Introducing the multiscale entropy dynamics (MED) methodology, we provide a framework for dissecting system dynamics and uncovering the driving forces behind their evolution. Our investigation reveals that the MED methodology facilitates the expression of complex system dynamics through a Generalized Nonlinear Schrödinger Equation (GNSE) that thus demonstrates its potential applicability across diverse complex systems. By elucidating the entropic underpinnings of complexity, our study paves the way for a deeper understanding of dynamic phenomena. It offers insights into the behavior of complex systems across various domains.

9.
Entropy (Basel) ; 26(4)2024 Apr 16.
Article in English | MEDLINE | ID: mdl-38667893

ABSTRACT

The adjoint function of connection number has unique advantages in solving uncertainty problems of water resource complex systems, and has become an important frontier and research hotspot in the uncertainty research of water resource complex problems. However, in the rapid evolution of the adjoint function, some problems greatly limit the application of the adjoint function in the research of water resources. Therefore, based on bibliometric analysis, development, practical application issues, and prospects of the hot directions are analyzed. It is found that the development of the connection number of water resource set pair analysis can be divided into three stages: (1) relatively sluggish development before 2005, (2) a period of rapid advancement in adjoint function research spanning from 2005 to 2017, and (3) a subsequent surge post-2018. The introduction of the adjoint function of connection number promotes the continuous development of set pair analysis of water resources. Set pair potential and partial connection number are the crucial research directions of the adjoint function. Subtractive set pair potential has rapidly developed into a relatively independent and important trajectory. The research on connection entropy is comparatively less, which needs to be further strengthened, while that on adjacent connection number is even less. The adjoint function of set pair potential can be divided into three major categories: division set pair potential, exponential set pair potential, and subtraction set pair potential. The subtraction set pair potential, which retains the original dimension and quantity variation range of the connection number, is widely used in water resources and other fields. Coupled with the partial connection number, a series of new connection number adjoint functions have been developed. The partial connection number can be mainly divided into two categories: total partial connection number, and semi-partial connection number. Among these, the calculation expression and connotation of total partial connection numbers have not yet reached a consensus, accompanied by the slow development of high-order partial connection numbers. Semi-partial connection number can describe the mutual migration movement between different components of the connection number, which develops rapidly. With the limitations and current situation described above, promoting the exploration and application of the adjoint function of connection number in the field of water resources and other fields of complex systems has become the focus of future research.

10.
PeerJ Comput Sci ; 10: e1983, 2024.
Article in English | MEDLINE | ID: mdl-38660165

ABSTRACT

Analyzing and obtaining useful information is challenging when facing a new complex system. Traditional methods often focus on specific structural aspects, such as communities, which may overlook the important features and result in biased conclusions. To address this, this article suggests an adaptive algorithm for exploring complex system structures using a generative model. This method calculates and optimizes node parameters, which can reflect the latent structural characteristics of the complex system. The effectiveness and stability of this method have been demonstrated in comparative experiments on 10 sets of benchmark networks using our model parameter configuration scheme. To enhance adaptability, algorithm fusion strategies were also proposed and tested on two real-world networks. The results indicate that the algorithm can uncover multiple structural features, including clustering, overlapping, and local chaining. This adaptive algorithm provides a promising approach for exploring complex system structures.

11.
J Chromatogr A ; 1722: 464857, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38569445

ABSTRACT

Epimer separation is crucial in the field of analytical chemistry, separation science, and the pharmaceutical industry. No reported methods could separate simultaneously epimers or even isomers and remove other unwanted, co-existing, interfering substances from complex systems like herbal extracts. Herein, we prepared a heptapeptide-modified stationary phase for the separation of 1R,2S-(-)-ephedrine [(-)-Ephe] and 1S,2S-(+)-pseudoephedrine [(+)-Pse] epimers from Ephedra sinica Stapf extract and blood samples. The heptapeptide stationary phase was comprehensively characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The separation efficiency of the heptapeptide column was compared with an affinity column packed with full-length ß2-AR functionalized silica gel (ß2-AR column). The binding affinity of the heptapeptide with (+)-Pse was 3-fold greater than that with (-)-Ephe. Their binding mechanisms were extensively characterized by chromatographic analysis, ultraviolet spectra, circular dichroism analysis, isothermal titration calorimetry, and molecule docking. An enhanced hydrogen bonding was clearly observed in the heptapeptide-(+)-Pse complex. Such results demonstrated that the heptapeptide can recognize (+)-Pse and (-)-Ephe epimers in a complex system. This work, we believe, was the first report to simultaneously separate epimers and remove non-specific interfering substances from complex samples. The method was potentially applicable to more challenging sample separation, such as chiral separation from complex systems.


Subject(s)
Ephedrine , Pseudoephedrine , Receptors, Adrenergic, beta-2 , Ephedrine/chemistry , Pseudoephedrine/chemistry , Receptors, Adrenergic, beta-2/chemistry , Receptors, Adrenergic, beta-2/metabolism , Molecular Docking Simulation , Ephedra sinica/chemistry , Chromatography, High Pressure Liquid/methods , Plant Extracts/chemistry , Humans , Stereoisomerism , Oligopeptides/chemistry , Oligopeptides/isolation & purification
12.
Mar Environ Res ; 198: 106515, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38688111

ABSTRACT

Given the exponential population growth and remarkable socio-economic advancements, coastal areas face increasingly complex challenges in eco-environmental management due to anthropogenic pressures. With the current emphasis on high-quality economic development, there is an urgent need to establish and evaluate a comprehensive indicator system to ensure the sustainable development of the coastal eco-environment and to meet evolving management demands. Research on the coordinated development level of coastal eco-environmental complex system, based on the concept of land-sea coordination, plays a pivotal role in promoting the resolution of eco-environmental issues in coastal areas, achieving sustainable socio-economic development in these regions. In this study, we construct an indicator system for the eco-environmental complex system in Jiaozhou Bay (JZB) coastal zone, China, comprising six sub-systems and thirty indicators. The comprehensive development level and coupling coordination degree model (CCDM) are employed in this study to analyze the indicator system in 1980-2020, aiming to elucidate the processes involved in the improvements in this complex system. The findings indicate: (i) the system's comprehensive development level evaluation and coupling coordination degree (CCD) exhibit a two-stage pattern: a declining trend in 1980-2005, followed by a rising trend in 2005-2020. (ii) despite improvements, the comprehensive development level and the CCD of the system in 2020 still hold potential for further enhancement compared to 1980; and (iii) policymaking and changes in anthropogenic pressures in coastal areas are the primary factors influencing the performance of the system. In the future, policymaking can reduce anthropogenic pressures on the coastal eco-environment, improve the comprehensive development level and CCD of the complex system, and encourage a commitment to sustainable development.


Subject(s)
Bays , Conservation of Natural Resources , Ecosystem , Environmental Monitoring , China , Environmental Monitoring/methods , Sustainable Development
13.
J R Soc Interface ; 21(212): 20230630, 2024 03.
Article in English | MEDLINE | ID: mdl-38442859

ABSTRACT

Modern computing has enhanced our understanding of how social interactions shape collective behaviour in animal societies. Although analytical models dominate in studying collective behaviour, this study introduces a deep learning model to assess social interactions in the fish species Hemigrammus rhodostomus. We compare the results of our deep learning approach with experiments and with the results of a state-of-the-art analytical model. To that end, we propose a systematic methodology to assess the faithfulness of a collective motion model, exploiting a set of stringent individual and collective spatio-temporal observables. We demonstrate that machine learning (ML) models of social interactions can directly compete with their analytical counterparts in reproducing subtle experimental observables. Moreover, this work emphasizes the need for consistent validation across different timescales, and identifies key design aspects that enable our deep learning approach to capture both short- and long-term dynamics. We also show that our approach can be extended to larger groups without any retraining, and to other fish species, while retaining the same architecture of the deep learning network. Finally, we discuss the added value of ML in the context of the study of collective motion in animal groups and its potential as a complementary approach to analytical models.


Subject(s)
Deep Learning , Animals , Mass Behavior , Fishes , Machine Learning , Motion
14.
Front Microbiol ; 15: 1338100, 2024.
Article in English | MEDLINE | ID: mdl-38318336

ABSTRACT

Wastewater-based epidemiology (WBE) has been used for monitoring infectious diseases like polio, hepatitis, etc. since the 1940s. It is also being used for tracking the SARS-CoV-2 at the population level. This article aims to compile and assess the information for the qualitative and quantitative detection of the SARS-CoV-2 in wastewater. Based on the globally published studies, we highlight the importance of monitoring SARS-CoV-2 presence/detection in the wastewater and concurrently emphasize the development of early surveillance techniques. SARS-CoV-2 RNA sheds in the human feces, saliva, sputum and mucus that ultimately reaches to the wastewater and brings viral RNA into it. For the detection of the virus in the wastewater, different detection techniques have been optimized and are in use. These are based on serological, biosensor, targeted PCR, and next generation sequencing for whole genome sequencing or targeted amplicon sequencing. The presence of the SARS-CoV-2 RNA in wastewater could be used as a potential tool for early detection and devising the strategies for eradication of the virus before it is spread in the community. Additionally, with the right and timely understanding of viral behavior in the environment, an accurate and instructive model that leverages WBE-derived data may be created. This might help with the creation of technological tools and doable plans of action to lessen the negative effects of current viral epidemics or future potential outbreaks on public health and the economy. Further work toward whether presence of viral load correlates with its ability to induce infection, still needs evidence. The current increasing incidences of JN.1 variant is a case in point for continued early detection and surveillance, including wastewater.

15.
Mar Pollut Bull ; 200: 116093, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38310722

ABSTRACT

Polyethylene terephthalate microplastics (PET-MPs) are one of pivotal nondegradable emerging pollutant. Here the variation of the surface physicochemical characteristics of PET-MPs with UV irradiation aging and the adsorption behaviors of PET-MPs in malachite green (MG), tetracycline (TC) solution and the effect of coexisting Cu(II) were comparatively investigated. The yellowing, weakened hydrophobicity, and increased surface negative charge, crystallinity degree and oxygen-containing functional groups were manifested specifically by the aged PET-MPs. Different from the single system, the hydrophobic interaction and metal ion bridging complexation dominated the adsorption of MG and TC, respectively, in the binary solution. While in the ternary solution, cationic ion competition of Cu(II) with MG decreased its capture, and the formation of PET-Cu(II)-TC ternary complexes promoted TC adsorption. Moreover, PET-MPs could serve as an efficient vector for MG and TC in MG/TC/Cu(II) ternary system, indicating PET-MPs tend to carry more varieties in the complex environment, that may increase the environmental risk of PET-MPs.


Subject(s)
Microplastics , Rosaniline Dyes , Water Pollutants, Chemical , Microplastics/chemistry , Plastics , Polyethylene Terephthalates , Water Pollutants, Chemical/analysis , Tetracycline , Anti-Bacterial Agents , Adsorption , Water , Polyethylene
16.
R Soc Open Sci ; 11(2): 231619, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38420628

ABSTRACT

How interactions between individuals contribute to the emergence of complex societies is a major question in behavioural ecology. Nonetheless, little remains known about the type of immediate social structure (i.e. social network) that emerges from relationships that maximize beneficial interactions (e.g. social attraction towards informed individuals) and minimize costly relationships (e.g. social avoidance of infected group mates). We developed an agent-based model where individuals vary in the degree to which individuals signal benefits versus costs to others and, on this basis, choose with whom to interact depending on simple rules of social attraction (e.g. access to the highest benefits) and social avoidance (e.g. avoiding the highest costs). Our main findings demonstrate that the accumulation of individual decisions to avoid interactions with highly costly individuals, but that are to some extent homogeneously beneficial, leads to more modular networks. On the contrary, individuals favouring interactions with highly beneficial individuals, but that are to some extent homogeneously costly, lead to less modular networks. Interestingly, statistical models also indicate that when individuals have multiple potentially beneficial partners to interact with, and no interaction cost exists, this also leads to more modular networks. Yet, the degree of modularity is contingent upon the variability in benefit levels held by individuals. We discuss the emergence of modularity in the systems and their consequences for understanding social trade-offs.

17.
BMC Health Serv Res ; 24(1): 178, 2024 Feb 08.
Article in English | MEDLINE | ID: mdl-38331778

ABSTRACT

BACKGROUND: The aim of this systematic review was to examine the relationship between strategies to improve care delivery for older adults in ED and evaluation measures of patient outcomes, patient experience, staff experience, and system performance. METHODS: A systematic review of English language studies published since inception to December 2022, available from CINAHL, Embase, Medline, and Scopus was conducted. Studies were reviewed by pairs of independent reviewers and included if they met the following criteria: participant mean age of ≥ 65 years; ED setting or directly influenced provision of care in the ED; reported on improvement interventions and strategies; reported patient outcomes, patient experience, staff experience, or system performance. The methodological quality of the studies was assessed by pairs of independent reviewers using The Joanna Briggs Institute critical appraisal tools. Data were synthesised using a hermeneutic approach. RESULTS: Seventy-six studies were included in the review, incorporating strategies for comprehensive assessment and multi-faceted care (n = 32), targeted care such as management of falls risk, functional decline, or pain management (n = 27), medication safety (n = 5), and trauma care (n = 12). We found a misalignment between comprehensive care delivered in ED for older adults and ED performance measures oriented to rapid assessment and referral. Eight (10.4%) studies reported patient experience and five (6.5%) reported staff experience. CONCLUSION: It is crucial that future strategies to improve care delivery in ED align the needs of older adults with the purpose of the ED system to ensure sustainable improvement effort and critical functioning of the ED as an interdependent component of the health system. Staff and patient input at the design stage may advance prioritisation of higher-impact interventions aligned with the pace of change and illuminate experience measures. More consistent reporting of interventions would inform important contextual factors and allow for replication.


Subject(s)
Emergency Service, Hospital , Quality Improvement , Humans , Aged , Aged, 80 and over , Female
18.
Healthcare (Basel) ; 12(2)2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38255108

ABSTRACT

Healthcare systems are facing a shortage of nurses. This article identifies some of the major causes of this and the issues that need to be solved. We take a perspective derived from queuing theory: the patient-nurse relationship is characterized by a scarcity of time and resources, requiring comprehensive coordination at all levels. For coordination, we take an information-theoretic perspective. Using both perspectives, we analyze the nature of healthcare services and show that ensuring slack, meaning a less than exhaustive use of human resources, is a sine qua non to having a good, functioning healthcare system. We analyze what coordination efforts are needed to manage relatively simple office hours, wards, and home care. Next, we address the level of care where providers cannot themselves prevent the complexity of organization that possibly damages care tasks and job quality. A lack of job quality may result in nurses leaving the profession. Job quality, in this context, depends on the ability of nurses to coordinate their activities. This requires slack resources. The availability of slack that is efficient depends on a stable inflow and retention rate of nurses. The healthcare system as a whole should ensure that the required nurse workforce will be able to coordinate and execute their tasks. Above that, workforce policies need more stability.

19.
Entropy (Basel) ; 25(12)2023 Dec 05.
Article in English | MEDLINE | ID: mdl-38136505

ABSTRACT

A postulate that relates global warming to higher entropy generation rate demand in the tropospheric is offered and tested. This article introduces a low-complexity model to calculate the entropy generation rate required in the troposphere. The entropy generation rate per unit volume is noted to be proportional to the square of the Earth's average surface temperature for a given positive rate of surface warming. The main postulate is that the troposphere responds with mechanisms to provide for the entropy generation rate that involves specific cloud morphologies and wind behavior. A diffuse-interface model is used to calculate the entropy generation rates of clouds. Clouds with limited vertical development, like the high-altitude cirrus or mid-altitude stratus clouds, are close-to-equilibrium clouds that do not generate much entropy but contribute to warming. Clouds like the cumulonimbus permit rapid vertical cloud development and can rapidly generate new entropy. Several extreme weather events that the Earth is experiencing are related to entropy-generating clouds that discharge a high rate of rain, hail, or transfer energy in the form of lightning. The water discharge from a cloud can cool the surface below the cloud but also add to the demand for a higher entropy generation rate in the cloud and troposphere. The model proposed predicts the atmospheric conditions required for bifurcations to severe-weather clouds. The calculated vertical velocity of thunderclouds associated with high entropy generation rates matches the recorded observations. The scale of instabilities for an evolving diffuse interface is related to the entropy generation rate per unit volume. Significant similarities exist between the morphologies and the entropy generation rate correlations in vertical cloud evolution and directionally solidified grainy microstructures. Such similarities are also explored to explore a generalized framework of pattern evolution and establish the relationships with the corresponding entropy generation rate. A complex system like the troposphere can invoke multiple phenomena that dominate at different spatial scales to meet the demand for an entropy generation rate. A few such possibilities are presented in the context of rapid and slow changes in weather patterns.

20.
Entropy (Basel) ; 26(1)2023 Dec 31.
Article in English | MEDLINE | ID: mdl-38248172

ABSTRACT

Causal inference aims to faithfully depict the causal relationships between given variables. However, in many practical systems, variables are often partially observed, and some unobserved variables could carry significant information and induce causal effects on a target. Identifying these unobserved causes remains a challenge, and existing works have not considered extracting the unobserved causes while retaining the causes that have already been observed and included. In this work, we aim to construct the implicit variables with a generator-discriminator framework named the Neural Causal Information Extractor (NCIE), which can complement the information of unobserved causes and thus provide a complete set of causes with both observed causes and the representations of unobserved causes. By maximizing the mutual information between the targets and the union of observed causes and implicit variables, the implicit variables we generate could complement the information that the unobserved causes should have provided. The synthetic experiments show that the implicit variables preserve the information and dynamics of the unobserved causes. In addition, extensive real-world time series prediction tasks show improved precision after introducing implicit variables, thus indicating their causality to the targets.

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