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PubMed2005

Prediction of care class by local additive reference to prototypical examples.

The public long-term care insurance program for the elderly in Japan set out in 2000 toward establishing a new system whereby citizens can be assured that they will receive care and be supported by the society as a whole. The insurance program includes computer-aided certification processes to estimate the needs for nursing care for clients. In this work, we show the applicability of an adaptive local nonlinear approximation method associated with the Japanese national database for automatic inference of the care class.

Aged↗
PubMed1995

Eye movement patterns in hemianopic dyslexia.

Homonymous parafoveal field loss impairs reading at the visual-sensory level. To elucidate the role of parafoveal visual field in reading, reading eye movements were recorded, by means of an infra-red registration technique, in 50 patients with homonymous hemianopia and visual field sparing ranging from 1 degree to 5 degrees; for comparison, a group of 25 normal subjects was studied. The degree of reading impairment in patients was found to depend on the extent of visual field sparing. Patients with right-sided loss of parafoveal visual field were more impaired than patients with left-sided loss. Eye movement reading patterns paralleled this observation. Left-sided field loss mainly impairs return eye movements to the beginning of a line, while right-sided field loss is characteristically associated with prolonged fixations times, reduced amplitudes of saccades to the right, and many regressive saccades. The analysis of the durations of fixations, and the amplitudes of saccadic eye shifts to the right, and their mutual dependencies, suggests that the perceptual window ('reading span') is altered: its spatial size is reduced, while its temporal extent is increased. The analysis of reading eye movements in 20 patients, who were treated for their hemianopic reading disorder, revealed, in part, a normalization of the eye movement pattern after treatment, indicating that the lost parafoveal field region can be successfully substituted by oculomotor adaptation. Our observations underline the importance of the parafoveal visual field for reading and support the hypothesis of a serial interplay between sensory-perceptual and cognitive factors in reading. Furthermore, reading eye movements appear to be guided primarily by parafoveal information processing; however, eye movement patterns show relative plasticity with respect to 'local' adaptation when the parafoveal field region is lost. The adaptation can best be explained by a change of the perceptual window which appears to be guided mainly by top-down influences. As to the brain lesion which may be responsible for the lack of effective oculomotor compensation, damage to the occipital white matter appears the most crucial condition because it may disconnect visual cortical areas, and interrupt subcortical-cortical connections which are part of a neural network subserving directed visual attention and associated saccadic eye shifts.

Adolescent↗
PubMed1969

The need to standardize descriptive cataloging.

Because there are too many ways to describe a book, its presence may not be discovered in a bibliography or catalog. Standardized descriptive cataloging is needed to solve this problem and also to eliminate wasteful duplication of cataloging. The Anglo-American Cataloging Rules and the COSATI Standard disagree on choice of main entry, and the Library of Congress does not follow the AACR all of the time. But the essence of standardized cataloging is widespread availability and general acceptance of the data, regardless of principles followed. Local adaptations in standard cataloging data are necesary, but those which affect all copies of a book, not just unique features of particular copies, must be made available for use by all libraries by correction of the standard cataloging data. The national structure for communicating standard cataloging data today is mainly printed tools, but tomorrow local library terminals on-line to a shared computer data bank may provide the instantaneous access needed. The problem of getting the wider community of library users to standardize their citation practices is more difficult to solve, but hope for improvement lies in making access to standard data easier.

Cataloging↗
PubMed1999

Drug resistance in intensive care units.

Intensive care units (ICUs) are generally considered epicenters of antibiotic resistance and the principal sources of outbreaks of multi-resistant bacteria. The most important risk factors are obvious, such as excessive consumption of antibiotics exerting selective pressure on bacteria, the frequent use of invasive devices and relative density of a susceptible patient population with severe underlying diseases. Infections due to antibiotic-resistant bacteria have a major impact on morbidity and health-care costs. Increased mortality is not uniformly shown for all of these organisms: Methicillin-resistant Staphylococcus aureus (MRSA) seems to cause significantly higher mortality, in contrast to vancomycin-resistant enterococci (VRE). Therefore it is essential to diminish these potential risk factors, especially by providing locally adapted guidelines for the prudent use of antibiotic therapy. A quality control of antimicrobial therapy within a hospital, and especially within the ICU, might help to minimize the selection of multidrug-resistant bacteria. The restricted use of antimicrobial agents in prophylaxis and therapy has also been shown to have at least temporal effects on local resistance patterns. New approaches to the problem of drug resistance in ICUs are badly needed.

Anti-Bacterial Agents↗
PubMed1999

Tracking the evolution of insecticide resistance in the mosquito Culex pipiens.

The evolution of pesticide resistance provides some of the most striking examples of darwinian evolution occurring over a human life span. Identification of resistance alleles opens an outstanding framework in which to study the evolution of adaptive mutations from the beginning of pesticide application, the evolution of interactions between alleles (dominance) or between loci (epistasis). Here we show that resistance alleles can also be used as markers to dissect population processes at a microevolutionary scale. We have focused on the antagonistic roles of selection and migration involved in the dynamics of local adaptation with reference to allelic frequencies at two resistance loci in the mosquito Culex pipiens. We find that their frequencies follow an annual cycle of large amplitude (25%), and we precisely unravel the seasonal variation of migration and selection underlying this cycle. Our results provide a firm basis on which to devise an insecticide treatment strategy that will better control the evolution of resistance genes and the growth of mosquito populations.

Alleles↗
PubMed2006

Cross-generational environmental effects and the evolution of offspring size in the Trinidadian guppy Poecilia reticulata.

The existence of adaptive phenotypic plasticity demands that we study the evolution of reaction norms, rather than just the evolution of fixed traits. This approach requires the examination of functional relationships among traits not only in a single environment but across environments and between traits and plasticity itself. In this study, I examined the interplay of plasticity and local adaptation of offspring size in the Trinidadian guppy, Poecilia reticulata. Guppies respond to food restriction by growing and reproducing less but also by producing larger offspring. This plastic difference in offspring size is of the same order of magnitude as evolved genetic differences among populations. Larger offspring sizes are thought to have evolved as an adaptation to the competitive environment faced by newborn guppies in some environments. If plastic responses to maternal food limitation can achieve the same fitness benefit, then why has guppy offspring size evolved at all? To explore this question, I examined the plastic response to food level of females from two natural populations that experience different selective environments. My goals were to examine whether the plastic responses to food level varied between populations, test the consequences of maternal manipulation of offspring size for offspring fitness, and assess whether costs of plasticity exist that could account for the evolution of mean offspring size across populations. In each population, full-sib sisters were exposed to either a low- or high-food treatment. Females from both populations produced larger, leaner offspring in response to food limitation. However, the population that was thought to have a history of selection for larger offspring was less plastic in its investment per offspring in response to maternal mass, maternal food level, and fecundity than the population under selection for small offspring size. To test the consequences of maternal manipulation of offspring size for offspring fitness, I raised the offspring of low- and high-food mothers in either low- or high-food environments. No maternal effects were detected at high food levels, supporting the prediction that mothers should increase fecundity rather than offspring size in noncompetitive environments. For offspring raised under low food levels, maternal effects on juvenile size and male size at maturity varied significantly between populations, reflecting their initial differences in maternal manipulation of offspring size; nevertheless, in both populations, increased investment per offspring increased offspring fitness. Several correlates of plasticity in investment per offspring that could affect the evolution of offspring size in guppies were identified. Under low-food conditions, mothers from more plastic families invested more in future reproduction and less in their own soma. Similarly, offspring from more plastic families were smaller as juveniles and female offspring reproduced earlier. These correlations suggest that a fixed, high level of investment per offspring might be favored over a plastic response in a chronically low-resource environment or in an environment that selects for lower reproductive effort.

Animals↗
PubMed1985

Quantitative description of chromatin structure during neoplasia by the method of image processing.

Nuclear chromatin is visualized by light microscopy as a mosaic of interchanging regions of low and high optical density (O.D.). The regions of high O.D. are well-defined as chromatin particles; features characterizing these particles enable the description of chromatin structure and the recognition of its changes during neoplasia. This paper presents a method of feature extraction by means of digital image analysis, based on a localization algorithm with locally adaptive thresholding. Although the chromatin particles varied greatly in their O.D., the algorithm enabled the identification of significant numbers of particles, which is essential in characterizing the complex architecture of chromatin. The results obtained by studying neoplastic nuclei and nuclei from control tissue suggest that the appearance of an additional class of chromatin particles, defined by their localization and optical density, is typical of chromatin changes during neoplasia.

Animals↗
PubMed2005

Development of emergency medicine administration in the People's Republic of China.

A collaborative partnership between the Johns Hopkins Hospital, Chaoyang Red Cross Hospital and Chinese Ministry of Health has been established to initiate Emergency Medicine (EM) administrative training in Beijing, China. The Emergency Medical Education and Training Center (EMETC) at Chaoyang Red Cross Hospital was opened as a training facility to foster EM administrative curriculum development and training nationwide. A six-step approach with problem identification, needs assessment, goals and objectives, educational strategies, implementation and evaluation was used to form a locally adapted curriculum. With a train-the-trainers model, the EMETC sponsored several EM administration courses, the first of their kind in China. Since its inception, the EMETC has trained 95 persons from throughout China in EM administration. An EM administration curriculum has been developed and refined. In conclusion, an international partnership between academic hospitals, supported by the local Ministry of Health, to develop a national training facility using this six-step approach may be an attractive strategy for dissemination of EM administration principles.

China↗
PubMed2006

Asymmetric gene flow and constraints on adaptation caused by sex ratio distorters.

Asymmetric gene flow is generally believed to oppose natural selection and potentially impede adaptation. Whilst the cause of asymmetric gene flow has been seen largely in terms of variation in population density over space, asymmetric gene flow can also result from varying sex ratios across subpopulations with similar population sizes. We model the process of adaptation in a scenario in which two adjacent subpopulations have different sex ratios, associated with different levels of infection with maternally inherited endosymbionts that selectively kill male hosts. Two models are analyzed in detail. First, we consider one host locus with two alleles, each of which possesses a selective advantage in one of the subpopulations. We found that local adaptation can strongly be impeded in the subpopulation with the more female biased population sex ratio. Second, we analyze host alleles that provide resistance against the male-killing (MK) endosymbionts and show that asymmetric gene flow can prevent the spread of such alleles under certain conditions. These results might have important implications for the coevolution of MK bacteria and their hosts.

Acclimatization↗
PubMed1993

Evidence for cAMP-independent thyrotropin effects on astroglial cells.

Thyroid hormones are essential for normal brain development and function. Brain astroglial cells express type II iodothyronine 5'-deiodinase which converts thyroxine into 3,5,3'-triiodothyronine. This type II deiodinase is regulated through various signalling pathways, allowing probably for the local adaptation of the level of 3,5,3'-triiodothyronine. Our results demonstrated that thyrotropin was able to induce type II deiodinase activity in astrocytes. A thyrotropin receptor was demonstrated. It was not coupled, as in thyroid, to adenylyl cyclase and phospholipase C, but it stimulated cytosolic phospholipase A2. The stimulation by thyrotropin of both thyroxine synthesis in thyroid and its local activation in astrocytes, could protect the brain from variations in the level of 3,5,3'-triiodothyronine.

Adenylyl Cyclases↗
PubMed2005

Outbreeding depression, but no inbreeding depression in haplodiploid Ambrosia beetles with regular sibling mating.

In sexual reproduction the genetic similarity or dissimilarity between mates strongly affects offspring fitness. When mating partners are too closely related, increased homozygosity generally causes inbreeding depression, whereas crossing between too distantly related individuals may disrupt local adaptations or coadaptations within the genome and result in outbreeding depression. The optimal degree of inbreeding or outbreeding depends on population structure. A long history of inbreeding is expected to reduce inbreeding depression due to purging of deleterious alleles, and to promote outbreeding depression because of increased genetic variation between lineages. Ambrosia beetles (Xyleborini) are bark beetles with haplodiploid sex determination, strong local mate competition due to regular sibling mating within the natal chamber, and heavily biased sex ratios. We experimentally mated females of Xylosandrus germanus to brothers and unrelated males and measured offspring fitness. Inbred matings did not produce offspring with reduced fitness in any of the examined life-history traits. In contrast, outcrossed offspring suffered from reduced hatching rates. Reduction in inbreeding depression is usually attributed to purging of deleterious alleles, and the absence of inbreeding depression in X. germanus may represent the highest degree of purging of all examined species so far. Outbreeding depression within the same population has previously only been reported from plants. The causes and consequences of our findings are discussed with respect to mating strategies, sex ratios, and speciation in this unusual system.

Analysis of Variance↗
PubMed2006

Transcriptome of local innate and adaptive immunity during early phase of infectious bronchitis viral infection.

To understand the mechanistic basis of local innate and adaptive immunity against infectious bronchitis virus (IBV) at the molecular level, we examined the gene transcription profile of tracheal epithelial layers 3 d after infection of chickens with an attenuated IBV-Massachusetts strain. Results suggested that the transcription levels of 365 genes were either upregulated or downregulated (2-fold and higher) after IBV infection. Among the upregulated 250 genes, 25 were directly immune-related genes. These upregulated immune response genes included TLR2, TLR3, interferon-induced antiviral genes (Mx), and genes responsible for cytotoxic T cell killing such as Fas antigen and granzyme-A. Overall, a diversity of innate immunity and helper T cell type 1 (Th1)-biased adaptive immunity are activated in the host's early defense against IBV invasion, and they are responsible for the rapid clearance of virus from the local infection.

Animals↗
PubMed2003

Rapid appearance of epistasis during adaptive divergence following colonization.

Theory predicts that short-term adaptation within populations depends on additive (A) genetic effects, while gene-gene interactions 'epistasis (E)' are important only in long-term evolution. However, few data exist on the genetic architecture of adaptive variation, and the relative importance of A versus non-additive genetic effects continues to be a central controversy of evolutionary biology after more than 70 years of debate. To examine this issue directly, we conducted hybridization experiments between two populations of wild soapberry bugs that have strongly differentiated in 100 or fewer generations following a host plant shift. Contrary to expectation, we found that between-population E and dominance (D) have appeared quickly in the evolution of new phenotypes. Rather than thousands of generations, adaptive gene differences between populations have evolved in tens. Such complex genetic variation could underlie the seemingly extreme rates of evolution that are increasingly reported in many taxa. In the case of the soapberry bug, extraordinary ecological opportunity, rather than mortality, may have created hard selection for genetic variants. Because ultimate division of populations into genetic species depends on epistatic loss of hybrid compatibility, local adaptation based on E may accelerate macro-evolutionary diversification.

Acclimatization↗
PubMed2006

Minimal control synthesis adaptive control of nonlinear systems: utilizing the properties of chaos.

This paper discusses a novel approach to the control of chaos based on the use of the adaptive minimal control synthesis algorithm. The strategies presented are based on the explicit exploitation of different properties of chaotic systems including the boundedness of the chaotic attractors and their topological transitivity (or ergodicity). It is shown that chaos can be exploited to synthesize more efficient control techniques for nonlinear systems. For instance, by using the ergodicity of the chaotic trajectory, we show that a local adaptive control strategy can be used to synthesize a global controller. An application is to the swing-up control of a double inverted pendulum.

Algorithms↗
PubMed2006

The maintenance of sex in bacteria is ensured by its potential to reload genes.

Why sex is maintained in nature is a fundamental question in biology. Natural genetic transformation (NGT) is a sexual process by which bacteria actively take up exogenous DNA and use it to replace homologous chromosomal sequences. As it has been demonstrated, the role of NGT in repairing deleterious mutations under constant selection is insufficient for its survival, and the lack of other viable explanations have left no alternative except that DNA uptake provides nucleotides for food. Here we develop a novel simulation approach for the long-term dynamics of genome organization (involving the loss and acquisition of genes) in a bacterial species consisting of a large number of spatially distinct populations subject to independently fluctuating ecological conditions. Our results show that in the presence of weak interpopulation migration NGT is able to subsist as a mechanism to reload locally lost, intermittently selected genes from the collective gene pool of the species through DNA uptake from migrants. Reloading genes and combining them with those in locally adapted genomes allow individual cells to readapt faster to environmental changes. The machinery of transformation survives under a wide range of model parameters readily encompassing real-world biological conditions. These findings imply that the primary role of NGT is not to serve the cell with food, but to provide homologous sequences for restoring genes that have disappeared from or become degraded in the local population.

Bacteria↗
PubMed2001

Genetic evidence for adaptation-driven incipient speciation of Drosophila melanogaster along a microclimatic contrast in "Evolution Canyon," Israel.

Substantial genetic differentiation, as great as among species, exists between populations of Drosophila melanogaster inhabiting opposite slopes of a small canyon. Previous work has shown that prezygotic sexual isolation and numerous differences in stress-related phenotypes have evolved between D. melanogaster populations in "Evolution Canyon," Israel, in which slopes 100-400 m apart differ dramatically in aridity, solar radiation, and associated vegetation. Because the canyon's width is well within flies' dispersal capabilities, we examined genetic changes associated with local adaptation and incipient speciation in the absence of geographical isolation. Here we report remarkable genetic differentiation of microsatellites and divergence in the regulatory region of hsp70Ba which encodes the major inducible heat shock protein of Drosophila, in the two populations. Additionally, an analysis of microsatellites suggests a limited exchange of migrants and lack of recent population bottlenecks. We hypothesize that adaptation to the contrasting microclimates overwhelms gene flow and is responsible for the genetic and phenotypic divergence between the populations.

Adaptation, Physiological↗
PubMed2001

Raising our sites: dissemination of supported education.

In order to promote replication of supported education, an exemplary rehabilitation model for adults with psychiatric disabilities, funds were accessed through a Community Action Grant from the Center for Mental Health Services of the Substance Abuse and Mental Health Services Administration. Three communities in Michigan participated in a multistage process designed to maximize community ownership by encouraging local adaptations involving all stakeholder groups and providing technical assistance. The stages in the process were organizing the community for supported education development, acquiring knowledge about supported education basics, collecting information (needs assessment and barrier identification), and developing the plan. All three sites have begun implementation, providing services to adults with psychiatric disabilities who wish to pursue post-secondary education. The approach employed has applicability for other local communities.

Community Participation↗
PubMed1989

The evaluation of bone remodeling about orthopaedic implants with ultrasound.

Total hip arthroplasty causes biomechanical changes in the normal femur, including a redistribution and concentration of stress. These mechanical alterations in the femur cause local remodeling and resorption that affect the geometry and mechanical properties of the bone. Two complementary ultrasonic techniques were used to study the local adaptive remodeling of bone due to prosthesis implantation. An ultrasonic wave propagation technique was used to determine elastic properties and a new scanning acoustic microscope (SAM) mapped the acoustic impedance profile of each section. The effects of the implantation of two types of hip prostheses, an uncemented bipolar prosthesis with an Austin-Moore type stem and a cemented Charnley prosthesis, were investigated. Both prostheses had a detrimental effect on local elastic properties as determined by acoustic velocity measurements. The SAM system provided information about local inhomogeneities in bone properties not obtainable by any other means. The acoustic impedance maps highlighted bone resorption and bone remodeling on a microstructural level.

Aged↗