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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↗
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↗
PubMed1993

[The Griscelli-Prunieras syndrome: a case report].

It is presented a six-year-old girl with silvered hair syndrome, of Griscelli-Prunieras variety; hereditary sickness with regressive autosomic and distinguished by partial albinism and leukocytic alterations. She presented the acute phase of the sickness distinguished by: hepatosplenomegaly, thrombocytopenia, lymphadenopathy generalized, and systematic infection; it is corroborated how a hemophagocytic syndrome; during her evolution developed pancerebellar syndrome. By laboratory were corroborated: decrease phagocytosis, degranulation 0%, decrease of globulins gamma, neutropenia, skin test of PPD and Candidin negatives, there were not find the giant inclusions in bone marrow leukocyte and peripheric blood that are feature of Chediak-Higashi syndrome. Another alteration that was the distribution of mote of melanin on the hair that in the Griscelli-Prunieras syndrome are six times bigger in the Chediak-Higashi syndrome.

Acute Disease↗
PubMed1994

Archaebacterial genomes: eubacterial form and eukaryotic content.

Since the recognition of the uniqueness and coherence of the archaebacteria (sometimes called Archaea), our perception of their role in early evolution has been modified repeatedly. The deluge of sequence data and rapidly improving molecular systematic methods have combined with a better understanding of archaebacterial molecular biology to describe a group that in some ways appears to be very similar to the eubacteria, though in others is more like the eukaryotes. The structure and contents of archaebacterial genomes are examined here, with an eye to their meaning in terms of the evolution of cell structure and function.

Archaea↗