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PubMed2026

Toward real-time quantification of driving risks: a systematic review and research agenda of risk field theory.

In complex traffic systems, driving risk often evolves in a continuous and progressive manner prior to crash occurrence. How to effectively represent and analyze such latent risk states remains a central challenge in traffic safety research. In recent years, risk field-based approaches have introduced spatial and spatiotemporal continuous modeling paradigms, providing new perspectives for characterizing the distribution of traffic risk and its dynamic evolution. Motivated by the rapid growth of this research area and the lack of a systematic synthesis, this paper presents a comprehensive review of studies applying risk field theory to driving safety and traffic risk analysis. Following the PRISMA guidelines, relevant literature was collected through multi-database searches and analyzed using a combination of bibliometric analysis and qualitative review. The review systematically summarizes the theoretical foundations, modeling elements, data sources, analytical methods, and application domains of risk field-related research. Particular attention is given to studies that conceptualize traffic risk as a continuous field, complemented by a broader review of traffic risk factor literature to identify key elements and analytical dimensions involved in risk field modeling. On this basis, the paper synthesizes research progress in major application areas, including traffic safety state representation, driving behavior analysis, traffic conflict assessment, and autonomous driving and human-machine cooperative systems. Differences and commonalities among existing studies are compared in terms of modeling strategies, data support, and application scenarios. Through this systematic review, the paper clarifies the main research themes and methodological trends of risk field-based studies, providing a structured framework for understanding the evolution and application of this approach and offering methodological insights for risk perception modeling and safety-oriented decision support in intelligent transportation systems (ITS).

Humans↗
PubMed1988

Free fitness that always increases in evolution.

I here introduce a free fitness function in population biology, which monotonically increases with time and takes its maximum at the evolutionary equilibrium. By suitably defining an "index" for each state, the free fitness is expressed as the average index plus an entropy term. In many cases, the index has a biologically clear meaning, such as the logarithmic population mean fitness. The technique is applicable to any Markov process model (either continuous or discrete) with a positive steady state. I discuss four examples from various branches of population biology: (1) one-locus-two-allele system of population genetics with mutation, selection, and random genetic drift; (2) evolutionary dynamics of quantitative characters; (3) a molecular evolution model; and (4) an ecological succession model. Introducing free fitness clarifies the balance between systematic forces (e.g. natural selection or successional trend toward the climax) and disturbing processes (e.g. random drift).

Animals↗
PubMed1995

Saltationist and punctuated equilibrium models for the evolution of viviparity and placentation.

Vertebrate viviparity (live-bearing reproduction), placentation, and placentotrophy are widely assumed to have evolved as three successive, gradualistic transformations. From empirical data and predictive tests on lizards and snakes, this paper indicates that placentae and a degree of placentotrophy have evolved repeatedly as necessary correlates of viviparity, not as subsequent modifications. In addition, information derived from studies of anatomy, physiology, biogeography and systematics is used to evaluate new saltationist and punctuated equilibrium models for the evolution of viviparity. Phylogenetic reconstruction reveals that more than 100 squamate clades have made the transition to viviparity and placentation. However, various phenotypic intermediates postulated by the gradualistic model are either scarce or unrepresented among known forms, including those in which viviparity has evolved at specific and subspecific levels. Evolution in squamates seems to have produced a dichotomy between two evolutionarily stable patterns: (i) retention of weakly shelled or shell-free eggs to term (viviparity), with development of fully functional placentae; and (ii) deposition of shelled eggs at or near the limb bud stage of development (typical oviparity). Conflicting functional demands placed on eggshell morphology may constrain establishment of prolonged, oviparous egg-retention as a viable, historically stable pattern. Alternatively, the costs of prolonged egg-retention associated with decreased female mobility or decreased fecundity may exceed the benefits in oviparous forms.

Animals↗
PubMed1996

The systematics of North American Daphnia (Crustacea: Anomopoda): a molecular phylogenetic approach.

Despite extensive studies on the ecology and evolution of the freshwater microcrustacean Daphnia, there is little understanding of the evolutionary history of the genus. Past attempts at reconstructing phylogenetic relationships among Daphnia species have been highly controversial, mainly because of the poor taxonomy of the genus. However, following a revised taxonomy of the daphniid fauna of North America, we conducted a comprehensive appraisal of systematic relationships within the genus through the analysis of sequence diversity in 503 b.p. of the 12S rRNA gene of the mtDNA. The large sequence divergence among its 34 North American members indicates that the genus Daphnia originated during the Mesozoic, even though many lineages exhibit extreme morphological stasis. Results from both cladistic and phenetic analyses indicate the presence of three subgenera comprised of 15 species complexes. Only four of these lineages have shown active speciation over the past 3 Ma, suggesting that cladogenesis in the genus has been constrained. Our study also reveals that interspecific hybridization occurs between taxa which show very large sequence divergence (up to 14%), suggesting that reproductive isolation within the genus evolves slowly.

Animals↗
PubMed1988

Can we guarantee the safety of genetically engineered organisms in the environment?

Concern about the safety of genetically engineered organisms in the environment arises from the undesirable results of earlier new technologies and introduced organisms. Progress towards safe release is complicated by the varied views of a diverse society, confusion of process and product, problems with existing methods, and the lack of practical experience with real releases. No categorically safe novel organisms exist, but a progressive series of releases should allow risks to be systematically reduced.

Animals↗
PubMed1990

Quality assessment in the medical intensive care unit: evolution of a data model.

Quality assessment and assurance in the intensive care unit require systematic monitoring and evaluation of patient care and its outcome. For analysis of these activities, data must be organized to reflect changes in such factors as patient types, ages, and lengths of stay. A model was developed to group data from the Cleveland Clinic Hospital medical intensive care unit into structural, process, and outcome categories. Development and application of the model are described.

Data Collection↗
PubMed1977

Suid evolution and correlation of African hominid localities.

Recently discovered Plio-Pleistocene vertebrate assemblages have allowed complete systematic revision of the sub-Saharan African Suidae. New phylogenies are proposed for the 7 genera and 16 species of fossil and extant representatives. Suids are common elements of African Plio-Pleistocene faunas, and their evolutionary trends, particularly in the species Mesochoerus limnetes and Metridiochoerus andrewsi, are of great correlative value. Suid data are employed in a refinement of stratigraphic correlations at Omo Shungura, Olduvai, and east of Lake Turkana (formerly East Rudolf) and in a correlation of East African and South African sites, with important implications for interpretation of hominid evolution. The suid record also bears significantly on questions of theoretical evolutionary biology.

Africa↗
PubMed1989

Cytological approaches to simuliid biosystematics in relation to the epidemiology and control of human onchocerciasis.

This paper presents an overview of advances in cytological research on the biosystematics of vector simuliid complexes in the areas of identification, age grading, and the evolution of resistance in relation to the epidemiology and control of human onchocerciasis. Systematic theory is discussed and relevant examples are given to show its application in predicting and resolving current problems in species identification for New World and Old World vector complexes. These complexes include Simulium damnosum s.l. and S. neavei s.l. from Africa and S. exiguum s.l., S. metallicum s.l., S. ochraceum s.l., and S. oyapockense s.l. from Latin America. The evolution of resistance in S. damnosum s.l. and the need for future molecular research as part of resistance management strategies are discussed.

Africa↗
PubMed1989

[Primary malignant melanoma of ORL mucosa. Apropos of 5 cases].

Based on five observations of primary mucosal melanomas recently treated in the department, the authors describe the main features of this very rare condition, and particularly the evolutive aspects in diagnosis and prognosis. Histological diagnosis is sometimes difficult, and must involve specific argentic staining and a search for the presence of the protein S100. Tumor thickness was systematically examined. No prognostic interpretation, however, is possible, given the small number of cases in the series. Evolution is unpredictable; there is very commonly a series of local recurrences which may be well controlled, followed by remote metastases remaining long quiescent, bypassing the cervical ganglion relay. Treatment is surgical whenever possible, with palliative radiotherapy for local recurrences and chemotherapy for metastatic forms. Other therapies have yet to prove their effectiveness.

Aged↗
PubMed1976

New karyological data of Rhinoderma: the chromosomes of Rhinoderma rufum.

The chromosomes of the Chilean frog Rhinoderma rufum are described for the first time. This chromosome set is compared with the karyotype of R. darwinii. The importance of the karyological data applied to the phylogeny and systematics of this genus are discussed. A tentative hypothesis of karyological evolution of Rhinoderma is given.

Animals↗
PubMed1976

Learning objectives in resident training. Objectives in clinical chemistry.

The use of learning objectives has recently found extensive application in the evolution of medical school curricula; however, they have not been utilized systematically in the education of pathology residents. In attempting to define the end-point behavior or objectives of a resident during a rotation in clinical biochemistry, 567 midwestern pathologists, clinical chemists and medical technologists working in chemistry sections rated proposed objectives as essentail, desirable but not essential, or not needed. Twenty-four of 52 objectives were considered essential for the resident to achieve by 75% or more of the respondents. These included 10 of 33 related to technical knowledge, 5 to 10 related to business and supervisory skills, 5 of 5 related to investigative problem solving, and 4 of 4 related to communicating with persons outside of the laboratory. In general, respondents considered knowledge of principles more important than technical skills. Management, business and communicative skills were highly rated.

Chemistry, Clinical↗
PubMed1991

Phylogenetic analysis of Alloglossidium Simer, 1929 (Digenea: Plagiorchiiformes: Macroderoididae) with discussion of the origin of truncated life cycle patterns in the genus.

Alloglossidium comprises 9 species of North American plagiorchiiform digeneans using ictalurid catfish, freshwater crustacea, and hirudinid leeches as definitive hosts. Two hypotheses about the evolution of this array of definitive hosts were examined using phylogenetic systematic analysis. Two most parsimonious trees, based on 15 homologous series derived from morphological data, each indicated the 2 species utilizing ictalurid catfish definitive hosts are basal members of the group, whereas the 2 species using freshwater crayfish definitive hosts and the 5 utilizing leech definitive hosts each comprise relatively derived monophyletic sister groups. The results suggest that species using crustaceans as definitive hosts are derived by life cycle truncation, whereas those using leeches as definitive hosts appear to be derived through a switch from crustaceans to leeches.

Animals↗
PubMed1993

[Sideroses of alveolar macrophages. Analysis of a continuous series of 360 bronchoalveolar lavages].

360 consecutive bronchoalveolar lavage fluids (BAL) were studied using semi-quantitative method described by GOLDE (GOLDE score). 44 hemosiderosis were detected (12%). Most of them corresponded to massive alveolar hemorrhage (AH). Depending on pathological contexts, we distinguished three main groups of AH frequency: a group of high frequency (around 40%), an intermediate group (10%) and a low frequency group with less than 5%. Matching cytological results with clinical and radiological data, revealed that AH was often too late diagnosed because inconstancy of typical clinical and radiological signs. Even with a variable prognosis related to different physiopathological mechanisms, AH evolution is unpredictable. The authors suggest thus BAL cytological examination may systematically include a research of hemosiderosis in AH high frequency groups.

Acquired Immunodeficiency Syndrome↗