Distribution by Scientific Domains

Kinds of Mark

  • bench mark
  • bite mark
  • deutsche mark
  • epigenetic mark
  • german mark
  • methylation mark
  • scent mark

  • Selected Abstracts

    Interactions of MAP/microtubule affinity regulating kinases with the adaptor complex AP-2 of clathrin-coated vesicles

    CYTOSKELETON, Issue 8 2009
    Gerold Schmitt-Ulms
    Abstract MARK [microtubule-associated proteins (MAPs)/microtubule affinity regulating kinase]/Par-1 (partition defective) phosphorylate MAPs tau, MAP2 and MAP4 at KXGS motifs and thereby regulate microtubule dynamics and transport processes in cells [Drewes et al., Cell1997;89:297,308]. We report here that MARK copurifies with clathrin-coated vesicles (CCVs) via interaction with the adaptor complex AP-2. The adaptin binding site on MARK includes the regulatory loop of its catalytic domain. Immunofluorescence demonstrates the colocalization of MARK with AP-2 and clathrin, as well as other MARK-interacting proteins such as PAK5. The results are consistent with an observed influence of MARK on the trafficking of CCVs. Cell Motil. Cytoskeleton 2009. © 2009 Wiley-Liss, Inc. [source]

    Declining winter survival and fitness implications associated with latitudinal distribution in Norwegian Greylag Geese Anser anser

    IBIS, Issue 1 2006
    The Norwegian Greylag Goose Anser anser population has been increasing steadily over the past few decades, causing increasing nuisance in terms of agricultural crop damage. This, in combination with the importance of Greylags as a hunting target, has called for demographic estimates for the population to assist in management decisions. To this end, we analysed long-term mark,recapture data using Cormack,Jolly-Seber models embedded in program MARK to obtain survival estimates for the population. No sex-specific difference, or age effect on survival after juveniles had completed their first migration (3 months of age), was evident. Mean first-year survival was reported as 0.485 and annual survival of older birds as 0.700. On a monthly basis, survival in Greylags during summer and winter was very similar over the study period. A significant linear decline in winter survival from 0.909 to 0.807 was, however, apparent during the study period. Over the second half of the study (1994,2002), summer survival was about 3% lower than in the first half (1986,94) but no linear relationship was evident. We found a significant inverse relationship between Greylag survival during summer and latitudinal distribution in Norway. A similar relationship was evident between survival and annual bag numbers. The changes in adult survival observed in this study are likely to have had a substantial impact on the growth rate of the Norwegian Greylag population. [source]

    Fine mapping and detection of the causative mutation underlying Quantitative Trait Loci

    E. Uleberg
    Summary The effect on power and precision of including the causative SNP amongst the investigated markers in Quantitative Trait Loci (QTL) mapping experiments was investigated. Three fine mapping methods were tested to see which was most efficient in finding the causative mutation: combined linkage and linkage disequilibrium mapping (LLD); association mapping (MARK); a combination of LLD and association mapping (LLDMARK). Two simulated data sets were analysed: in one set, the causative SNP was included amongst the markers, while in the other set the causative SNP was masked between markers. Including the causative SNP amongst the markers increased both precision and power in the analyses. For the LLD method the number of correctly positioned QTL increased from 17 for the analysis without the causative SNP to 77 for the analysis including the causative SNP. The likelihood of the data analysis increased from 3.4 to 13.3 likelihood units for the MARK method when the causative SNP was included. When the causative SNP was masked between the analysed markers, the LLD method was most efficient in detecting the correct QTL position, while the MARK method was most efficient when the causative SNP was included as a marker in the analysis. The LLDMARK method, combining association mapping and LLD, assumes a QTL as the null hypothesis (using LLD method) and tests whether the ,putative causative SNP' explains significantly more variance than a QTL in the region. Thus, if the putative causative SNP does not only give an Identical-By-Descent (IBD) signal, but also an Alike-In-State (AIS) signal, LLDMARK gives a positive likelihood ratio. LLDMARK detected less than half as many causative SNPs as the other methods, and also had a relatively high false discovery rate when the QTL effect was large. LLDMARK may however be more robust against spurious associations, because the regional IBD is largely corrected for by fitting a QTL effect in the null hypothesis model. [source]

    Putting density dependence in perspective: nest density, nesting phenology, and biome, all matter to survival of simulated mallard Anas platyrhynchos nests

    Johan Elmberg
    Breeding success in ground-nesting birds is primarily determined by nest survival, which may be density-dependent, but the generality of this pattern remains untested. In a replicated crossover experiment conducted on 30 wetlands, survival of simulated mallard nests was related to "biome" (n=14 mediterranean and 16 boreal wetlands), breeding "phenology" (early vs late nests), and "density" (2 vs 8 nests per 225 m shoreline). Local abundances of "waterfowl", "other waterbirds", and "avian predators" were used as covariates. We used an information-theoretic approach and Program MARK to select among competing models. Nest survival was lower in late nests compared with early ones, and it was lower in the mediterranean than in the boreal study region. High-density treatment nests suffered higher depredation rates than low-density nests during days 1,4 of each experimental period. Nest survival was negatively associated with local abundance of "waterfowl" in the boreal but not in the mediterranean biome. Effect estimates from the highest-ranked model showed that nest "density" (d 1,4) had the strongest impact on model fit; i.e. three times that of "biome" and 1.5 times that of "phenology". The latter,s effect, in turn, was twice that of "biome". We argue that our study supports the idea that density-dependent nest predation may be temporally and spatially widespread in waterfowl. We also see an urgent need for research of how waterfowl nesting phenology is matched to that of prey and vegetation. [source]

    Nest survival for two species of manakins (Pipridae) in lowland Ecuador

    Thomas B. Ryder
    Estimates of reproductive success are essential to understand life-history strategies, yet tropical species remain under-studied relative to their temperate counterparts. Here, we report nest survival probabilities for two manakin species (Pipridae). We monitored 61 wire-tailed manakin Pipra filicauda and 45 blue-crowned manakin Lepidothrix coronata nests during three breeding seasons. Both species suffered high nest failure (84%). We modeled the effects of year, nest height, nest age (for P. filicauda only), as well as nest manipulation on daily survival rates (DSR) using program MARK. DSR decreased with nest age in P. filicauda whereas a constant survival model was best fitted for L. coronata. Average DSR was 89% for P. filicauda and 85% for L. coronata. This study reports some of the lowest nest survival rates among tropical passerines and poses important questions about population maintenance. [source]

    Sex-biased juvenile survival in a bird with extreme size dimorphism, the great bustard Otis tarda

    Carlos A. Martín
    We explored sex-biased mortality patterns in a species showing the most extreme sexual dimorphism among birds, the great bustard Otis tarda. Between 1991 and 2005 we studied juvenile and immature survival in a sample of 361 great bustards radio-tagged at two different populations in Spain, Villafáfila and Madrid. Mortality decreased with age, from high rates during the first year (0.70), to 0.10 in the second year. Using the known-fate model in program MARK we found that monthly survival increased throughout the first year. Offspring showing higher body mass at marking, i.e. those hatched earlier in the season and those with better body condition, survived in higher proportion. This was probably related to the earlier breeding dates of more experienced mothers, as well as to the observed decrease in food availability as the season progresses. Monthly survival estimates were higher in females than in males, which suggests that juvenile males are more vulnerable to reduced food availability and other factors due to their much faster growth rates. The proportion of non-natural deaths increased with age, and was higher in the Madrid population, where illegal hunting and collision with powerlines showed a high incidence. The male-biased mortality found in young birds in this study explains the female-biased population sex ratios observed in great bustard populations. The different degrees of incidence of human-induced causes of mortality found between both populations studied suggest that such differences may contribute to the variation observed in the adult sex ratio among populations. [source]

    Colored plastic and metal leg bands do not affect survival of Piping Plover chicks

    Erin A. Roche
    ABSTRACT Leg bands are commonly used to mark shorebird chicks as young as 1-d old, but little is known about the possible impacts of bands on survival of prefledging shorebirds. We used a mark-recapture framework to assess the impact of bands and banding-related disturbance on prefledging survival in a federally endangered population of Piping Plovers (Charadrius melodus) breeding in the Great Lakes region from 2000 to 2008. We banded approximately 96% of all surviving chicks hatched prior to fledging, typically between 5 and 15 d of age. We used a multistate approach in program MARK whereby individuals contributed data as unbanded chicks before capture (N= 1073) and as banded chicks afterward (N= 780). The cumulative probability of surviving through 24 d of age was 0.63 and did not differ between banded and unbanded chicks. In addition, we found a positive effect of banding-related disturbance on survival up to 3 d following banding (,= 0.60 CI: 0.17,1.02), possibly due to increased postbanding vigilance on the part of chicks and adults. Our results indicate that banding has no detrimental effect on survival of Piping Plover chicks prior to fledging and that current capture and banding methods are appropriate for this endangered species. RESUMEN Los anillos son comúnmente utilizados para marcar los polluelos de aves playeras desde edades tempranas como un día de eclosionados, pero poco se conoce sobre los posibles impactos que estos anillos puedan tener sobre la supervivencia antes de abandonar el nido en aves playeras. Usamos técnicas de marca recaptura para estimar el impacto de los anillos y disturbios asociados a este proceso en la supervivencia antes de abandonar el nido en una población federal en peligro de Charadrius melodus anidando en la región de los grandes lagos desde el 2000 hasta el 2008. Anillamos aproximadamente 96% de todos los polluelos que sobrevivieron después de la eclosión y antes de abandonar el nido, normalmente entre 5,15 días de nacidos. Usamos una aproximación de estado múltiple en el programa MARK en el cual se dividieron los datos en polluelos sin anillar antes de la captura (N= 1073) y polluelos después de ser anillados (N= 780). La probabilidad acumulada de supervivencia a través de 24 días de edad fue 0.63 y no existieron diferencias entre polluelos anillados y no anillados. Adicionalmente, encontramos un efecto positivo relacionado con el disturbio creado durante le anillamiento en la supervivencia hasta tres días después del anillamiento (,= 0.60 CI: 0.17,1.02), posiblemente debido al incremento de vigilancia después del anillamiento por parte de los polluelos y adultos. Nuestros resultados indican que el anillamiento no tiene efectos negativos sobre la supervivencia de polluelos de Charadrius melodus antes de abandonar el nido y que los métodos de anillamiento y captura actualmente utilizados son apropiados para esta especie en peligro. [source]


    John Dickson

    Demography and population viability of polar bears in the Gulf of Boothia, Nunavut

    Mitchell K. Taylor
    Abstract We estimated demographic parameters and harvest risks for polar bears (Ursus maritimus) inhabiting the Gulf of Boothia, Nunavut, from 1976 to 2000. We computed survival and abundance from capture,recapture and recovery data (630 marks) using a Burnham joint live,dead model implemented in program MARK. Annual mean total survival (including harvest) was 0.889 ± 0.179 (x,± 1 SE) for cubs, 0.883 ± 0.087 for subadults (ages 1,4), 0.919 ± 0.044 for adult females, and 0.917 ± 0.041 for adult males. Abundance in the last 3 yr of study was 1,592 ± 361 bears. Mean size of newborn litters was 1.648 ± 0.098 cubs. By age 7, 0.97 ± 0.30 of available females were producing litters. Harvest averaged 38.4 ± 4.2 bears/year in the last 5 yr of study; however, the 2002,2007 kill averaged 56.4 bears/yr. We used a harvested Population Viability Analysis (PVA) to examine impacts of increasing rates of harvest. We estimated the current population growth rate, ,H, to be 1.025 ± 0.032. Although this suggests the population is growing, progressive environmental changes may require more frequent population inventory studies to maintain the same levels of harvest risk. [source]


    Andrew M. Gormley
    Abstract Capture-recapture techniques have been extensively used to estimate survival rates of Hector's dolphins at Banks Peninsula, but not abundance. We analyzed nine seasons of photo-identification data using a model-fitting approach in the computer program MARK, and then used MARK's estimates of capture probabilities to calculate the abundance of distinctive individuals. We extrapolated these estimates to include unmarked individuals using five seasons of data on the proportion of identifiable individuals in this population, obtained from "random photography." This capture-recapture approach suggests a 1996 population of about 1,100 (CV = 0.21). This is very similar to the 1997 line-transect estimate of about 900 (CV = 0.28), especially considering that the two techniques do not necessarily measure the same thing. An important advantage of the capture-recapture approach stems from the inherent versatility of photo-ID data. If the sampling design is appropriate, an unbiased abundance estimate can be achieved as a spin-off from work directed at other questions. However, in our view, line-transect estimates are easier to interpret because the sampling design is explicit. [source]


    Summary. In 1977 Grahame Clark suggested that the siting of megalithic tombs along the west coast of Scandinavia reflected the distribution of productive fishing grounds. Unlike the situation in other parts of Europe, these monuments were not associated with agriculture. Opinions have varied over the last quarter century, but enough is now known about changes of sea-level for his interpretation to be investigated on the ground. There seems to have been considerable diversity. On the large island of Örust some of the tombs located near to the sea appear to be associated with small natural enclosures defined by rock outcrops and may have been associated with grazing land. On the neighbouring island of Tjörn, however, the tombs were associated with small islands and important sea channels. During the Bronze Age the same areas included carvings of ships. Recent fieldwork in western Norway suggests that such locations were especially important in a maritime economy. [source]

    Estimating Abundance Using Mark,Resight When Sampling Is with Replacement or the Number of Marked Individuals Is Unknown

    BIOMETRICS, Issue 1 2009
    Brett T. McClintock
    Summary Although mark,resight methods can often be a less expensive and less invasive means for estimating abundance in long-term population monitoring programs, two major limitations of the estimators are that they typically require sampling without replacement and/or the number of marked individuals available for resighting to be known exactly. These requirements can often be difficult to achieve. Here we address these limitations by introducing the Poisson log and zero-truncated Poisson log-normal mixed effects models (PNE and ZPNE, respectively). The generalized framework of the models allow the efficient use of covariates in modeling resighting rate and individual heterogeneity parameters, information-theoretic model selection and multimodel inference, and the incorporation of individually unidentified marks. Both models may be implemented using standard statistical computing software, but they have also been added to the mark,recapture freeware package Program MARK. We demonstrate the use and advantages of (Z)PNE using black-tailed prairie dog data recently collected in Colorado. We also investigate the expected relative performance of the models in simulation experiments. Compared to other available estimators, we generally found (Z)PNE to be more precise with little or no loss in confidence interval coverage. With the recent introduction of the logit-normal mixed effects model and (Z)PNE, a more flexible and efficient framework for mark,resight abundance estimation is now available for the sampling conditions most commonly encountered in these studies. [source]

    Survival of Bowhead Whales, Balaena mysticetus, Estimated from 1981,1998 Photoidentification Data

    BIOMETRICS, Issue 4 2002
    Judith Zeh
    Summary. Annual survival probability of bowhead whales, Balaena mysticetus, was estimated using both Bayesian and maximum likelihood implementations of Cormack and Jolly-Seber (JS) models for capture-recapture estimation in open populations and reduced-parameter generalizations of these models. Aerial photographs of naturally marked bowheads collected between 1981 and 1998 provided the data. The marked whales first photographed in a particular year provided the initial ,capture' and ,release' of those marked whales and photographs in subsequent years the ,recaptures'. The Cormack model, often called the Cormack-Jolly-Seber (CJS) model, and the program MARK were used to identify the model with a single survival and time-varying capture probabilities as the most appropriate for these data. When survival was constrained to be one or less, the maximum likelihood estimate computed by MARK was one, invalidating confidence interval computations based on the asymptotic standard error or profile likelihood. A Bayesian Markov chain Monte Carlo (MCMC) implementation of the model was used to produce a posterior distribution for annual survival. The corresponding reduced-parameter JS model was also fit via MCMC because it is the more appropriate of the two models for these photoidentification data. Because the CJS model ignores much of the information on capture probabilities provided by the data, its results are less precise and more sensitive to the prior distributions used than results from the JS model. With priors for annual survival and capture probabilities uniform from 0 to 1, the posterior mean for bowhead survival rate from the JS model is 0.984, and 95% of the posterior probability lies between 0.948 and 1. This high estimated survival rate is consistent with other bowhead life history data. [source]


    Shannon Gowans
    Abstract The use of natural marks in capture-recapture studies can lead to unequal capture probabilities. This paper examined a catalog of northern bottlenose whale (Hyperoodon ampullatus) photographs from the Gully, Nova Scotia, to identify potential sources of heterogeneity. This information can be used to select appropriate individuals and photographs to include in analyses. Individual northern bottlenose whales were sufficiently marked to uniquely identify individuals (x,= 14.5 marks/individual; range 1-67), but not all mark types persisted over time. Reliable marks were defined as mark types that were not lost over the nine-yeat study period (notches, back indentation, and mottled patches). Individuals were considered reliably marked if they possessed at least one back indentation or mottled patch (located within one dorsal fin width, at the base of the dorsal fin) or a notch on the dorsal fin. Sixty-six percent (SE = 5%) of the population were reliably marked. Longterm analyses (months to years) should use only reliably marked individuals, and the results scaled to account for the rest of the population. Our results also showed that photographic quality affected an observer's ability to identify individuals. For this catalog, quantitative analysis indicated only photographs of Q , 4 (on a 6-point scale with 6 representing the highest quality) should be included in mark-recapture analyses sensitive to heterogeneity. [source]

    Silver Medal Recipient 2006 , PROFESSOR ROBIN MARKS

    John Brenan
    No abstract is available for this article. [source]


    Dipankar Bandyopadhyay
    Summary A new function for the competing risks model, the conditional cumulative hazard function, is introduced, from which the conditional distribution of failure times of individuals failing due to cause,j,can be studied. The standard Nelson,Aalen estimator is not appropriate in this setting, as population membership (mark) information may be missing for some individuals owing to random right-censoring. We propose the use of imputed population marks for the censored individuals through fractional risk sets. Some asymptotic properties, including uniform strong consistency, are established. We study the practical performance of this estimator through simulation studies and apply it to a real data set for illustration. [source]

    Quality of life and health-related quality of life of adolescents with cerebral palsy

    Peter L Rosenbaum MD FRCP(C)
    This study assessed quality of life (QOL) and health-related quality of life (HRQOL) of 203 adolescents with cerebral palsy (111 males, 92 females; mean age 16y [SD 1y 9mo]). Participants were classified using the Gross Motor Function Classification System (GMFCS), as Level I (n=60), Level II (n=33), Level III (n=28), Level IV (n=50), or Level V (n=32). QOL was assessed by self (66.5%) or by proxy (33.5%) with the Quality of Life Instrument for People With Developmental Disabilities, which asks about the importance and satisfaction associated with the QOL domains of Being, Belonging, and Becoming; HRQOL was captured through proxy reports with the Health Utilities Index, Mark 3 (HUI3), which characterizes health in terms of eight attributes, each having five or six ordered levels of function. GMFCS level was not a source of variation for QOL domain scores but was significantly associated with the eight HRQOL attributes and overall HUI3 utility scores (p<0.05). Some QOL domain scores varied significantly by type of respondent (self vs proxy; p<0.05). Overall HUI3 utility values were significantly but weakly correlated with QOL Instrument scores for Being (r=0.37), Belonging (r=0.17), Becoming (r=0.20), and Overall QOL (r=0.28), and thus explain up to 14% of the variance (r2). These findings suggest that although QOL and HRQOL are somewhat related conceptually, they are different constructs and need to be considered as separate dimensions of the lives of people with functional limitations. [source]

    Dispersal ability and host-plant characteristics influence spatial population structure of monophagous beetles

    Matthew J. St Pierre
    Abstract., 1. Dispersal plays an integral role in determining spatial population structure and, consequently, the long-term survival of many species. Theoretical studies indicate that dispersal increases with population density and decreasing habitat stability. In the case of monophagous insect herbivores, the stability of host-plant populations may influence their spatial population structure. 2. The tallgrass prairie in Iowa, U.S.A. is highly fragmented and most prairie insects face a landscape with fewer habitat patches and smaller host-plant populations than 150 years ago, potentially making dispersal between patches difficult. Some herbivores, however, use native plant species with weedy characteristics that have increased in abundance because of disturbances. 3. Mark,recapture data and presence,absence surveys were used to examine dispersal and spatial population structure of two monophagous beetles with host plants that exhibit different population stability and have responded differently to fragmentation of tallgrass prairie. 4. Chrysochus auratus Fabricius exhibits a patchy population structure and has relatively large dispersal distances and frequencies. Its host plant is variable locally in time and space, but is more abundant than 150 years ago. The other species, Anomoea laticlavia Forster, exhibits a metapopulation or non-equilibrium population structure and has relatively small dispersal distances and frequencies. Its host-plant populations are stable in time and space. 5. The results indicate that dispersal ability of monophagous beetles reflects the life-history dynamics of their host plants, but the spatial population structure exhibited today is strongly influenced by how the host plants have responded to the fragmentation process over both time and space. [source]

    Dispersal between host populations in field conditions: navigation rules in the parasitoid Venturia canescens

    E. Desouhant
    Abstract. 1. Dispersal is a life-history trait that can have great ecological and evolutionary consequences, however understanding of how insects disperse is limited. 2. Navigation rules of the solitary koinobiont parasitoid of the pyralid moth larvae Venturia canescens (Gravenhorst) were studied in conditions that it is likely to meet when dispersing between host populations and in the absence of cues related directly to the presence of hosts. 3. Mark,release,recapture experiments were conducted in a natural host-free habitat, and letting the animals disperse for different periods. 4. In the presence of vegetation, wasps seemed to disperse rapidly (1 h for an area of ,,1 ha) and capture rates were independent of both dispersal time and distance from the release point. 5. The navigation rules of V. canescens during dispersal between tree stands can be summarised as: move up- or down-wind, avoid or pass through open, sunny areas, and go for shady and dense vegetation. 6. The consequences of the navigation rules for host,parasitoid dynamics are discussed in relation to different spatial scales. [source]

    Losing more than gaining from overall stable prices: the differential perception of increasing versus decreasing prices made the Euro look like a price booster

    Tobias Greitemeyer
    The present research examined whether price trend misperceptions can be explained by the differential perception of increasing versus decreasing prices. We expected price increases (losses to consumers) to be perceived as being more intense than price decreases (gains to consumers) of the same magnitude. This tendency, in turn, should be positively associated with how people perceive the overall price trend. To test this reasoning, participants in the first two studies were asked to compare German Mark (DM) and Euro prices. First, participants received a menu containing 21 dishes with DM prices, and their price trend expectations were assessed. Then, participants indicated for each dish to what extent the price had changed. Finally, participants' overall price trend judgments were assessed. In both studies, results indicate that price trend judgments were biased toward rising prices. In addition, price increases were perceived as rising more than price decreases of the same magnitude were perceived as falling. This tendency was positively associated with overall price trend judgments, even after controlling for expectations. Study 3 was to replicate these findings in a different domain to demonstrate the general nature and impact of the hypothesized effect. Copyright © 2007 John Wiley & Sons, Ltd. [source]

    Classifying tagging experiments for commercial fisheries into three fundamental types based on design, data requirements and estimable population parameters

    FISH AND FISHERIES, Issue 2 2010
    Tom Polacheck
    Abstract Mark,recapture experiments have the potential to provide direct estimates of fundamental parameters required for fishery stock assessment and provision of subsequent management advice in fisheries. The literature on mark,recapture experiments is enormous, with a variety of different experimental designs and estimation models; thus, it can be difficult to grasp the primary features of different approaches, the inter-relationship among them and their potential utility in different situations. Here, we present an overview of the tagging experimental designs that are appropriate for use in commercial fishery situations. We suggest that most mark,recapture experiments in a large-scale fishery context can be classified into one of three basic types , Petersen, tag-attrition or Brownie , based on the fundamental design employed for releases and recaptures. The release and recapture strategy (e.g. the number of release events, whether the size of the sample examined for recaptured tags is known) determines which parameters can be estimated and from where the information for estimating them arises. We conclude that an integrated Brownie and Petersen approach is the most powerful of the different approaches in terms of the range of parameters that can be estimated without underlying assumptions or constraints on parameters. Such an approach can provide direct estimates of fishing mortality, natural mortality and population size, which are the main population dynamics parameters that traditional fishery stock assessments attempt to estimate. [source]

    ,Defence lignin' and hydroxycinnamyl alcohol dehydrogenase activities in wounded Eucalyptus gunnii

    FOREST PATHOLOGY, Issue 2 2003
    S. Hawkins
    Summary To learn more about lignin formation in response to wounding in trees, we adopted two complementary approaches: (1) microscopic and histochemical studies of the wound response in 3.5-month-old Eucalyptus gunnii plantlets and (2) biochemical investigations of hydroxycinnamyl alcohol dehydrogenase activities in wounded 6-year-old, field-grown E. gunnii trees. The first approach revealed that a barrier zone was formed in response to wounding in both ground tissues (cortex barrier and pith reaction zone) and vascular tissues. The barrier zone was barely detectable after 24 h but well-developed 7 days after wounding. Microscopic analyses indicated that the barrier zone was formed by the reinforcement of cell walls with ,lignin-like material' in both ground tissues and vascular tissue, and that, in addition, the lumen of certain xylem cells (vessels and fibres) were blocked by the deposition of polymeric phenolic material. Histochemical characterization revealed that the lignin-like material (,defence lignin') deposited in ground tissue cell walls and xylem cell blockages was poor in syringyl (S-type) lignin units and therefore differed from the usual mixed guaiacyl,syringyl (G,S) lignin unit composition of E. gunnii developmental lignin. In contrast, S-type lignin appeared to be deposited in the cell walls of immature developing secondary xylem cells at a stage when the cell walls of comparable cells from unwounded control stems contained lignin poor in syringyl units. The second approach indicated that two different types of cinnamyl alcohol dehydrogenase activity are induced, and apparently regulated differentially, in response to wounding in E. gunnii trees. Coniferyl alcohol dehydrogenase activity was induced immediately and continued to increase throughout the first 15 days of the 17-day experimental period, while sinapyl alcohol dehydrogenase activity was first detected at 8 days after wounding and continued to increase throughout the experimental period. The biological roles of the two alcohol dehydrogenase activities are discussed in relation to the formation of defence lignin versus developmental lignin in trees. Résumé Afin d'approfondir nos connaissances concernant la formation de lignine en réponse aux blessures chez les arbres, nous avons utilisé deux approches complémentaires: (1) des études microscopiques et histochimiques de la réponse à la blessure chez les plantules d'Eucalyptus gunniiâgées de 3 mois et demi, et (2) des analyses biochimiques des activités alcools hydroxycinnamyliques déshydrogénases chez les arbres âgés de 6 ans blessés au champ. L'utilization de la première approche a révélé qu'une barrière physique se forme en réponse à la blessure aux niveaux des tissus vasculaires, de la moelle, et des tissus externes au phloème. A 24 h après la blessure, cette barrière est peu développée mais elle est bien formée après 7 jours. Les analyses microscopiques et histochimiques ont indiqué que les parois cellulaires au niveau de la barrière sont renforcées par un composé semblable à la lignine (,lignin-like material'). De plus, les lumens de plusieurs cellules xylémiennes (vaisseaux et fibres) sont bouchées par le dépôt d'un composé polymérique de nature phénolique. Les caractérizations histochimiques ont indiqué que le ,lignin-like material' (lignine de défense) déposé dans les parois cellulaires de la moelle et des tissus externes au phloème, et dans les lumens des cellules xylemiennes, contient peu d'unités syringyles (type-S). En conséquence, cette ,lignine de défense' se distingue de la ,lignine de développement' typique d'E. gunnii, qui est composée d'unités guaiacyles (type-G) et d'unités syringyles (type-S). En revanche chez les plantules blessées, des unités syringyles sont déposées dans les parois des cellules immatures du xylème à un stade où les cellules comparables des plantules témoins ne contiennent que très peu d'unités syringyles. La deuxième approche a indiqué que deux activités alcools cinnamyliques déshydrogénases différentes sont induites, et régulées d'une façon différencielle, en réponse à la blessure chez les arbres d'E. gunnii. L'activité alcool coniférylique déshydrogénase est induite rapidement et continue d'augmenter pendant les 15 premiers jours de la période expérimentale de 17 jours, tandis que l'activité alcool sinapylique déshydrogénase est seulement détectée à 8 jours après la blessure et continue d'augmenter le long de la période expérimentale. Les rôles biologiques potentiels de ces deux activités alcools déshydrogénases sont discutés en relation avec la formation de la lignine de défense et avec la lignine de développement chez les arbres. Zusammenfassung Zur Untersuchung der Ligninbildung nach Verletzungen bei Bäumen wurden zwei sich ergänzende Forschungsansätze gewählt: 1. Mikroskopische und histochemische Untersuchungen der Wundreaktion an Jungpflanzen (3,5 Monate alt) von Eucalyptus gunnii und 2. Biochemische Untersuchungen der Hydroxycinnamylalkohol-Dehydrogenase-Aktivität bei verletzten, sechs Jahre alten E. gunnii -Bäumen im Freiland. Der erste Ansatz zeigte, dass eine Barrierezone als Antwort auf die Verletzung sowohl in beiden Grundgeweben (Cortex-Barriere und Reaktionszone im Mark) als auch in den Leitgeweben gebildet wird. Die Barrierezone war 24 Stunden nach der Verletzung gerade erkennbar, nach sieben Tagen war sie gut entwickelt. Die mikroskopische Untersuchung zeigte, dass die Barrierezone durch Verstärkung der Zellwände mit ,,ligninartigem Material,, im Grund- und Leitgewebe gebildet wurde, und dass zusätzlich das Lumen gewisser Xylemzellen (Gefässe und Fasern) durch Ablagerung von polymerem phenolischem Material verschlossen wurde. Die histochemische Analyse ergab, dass das ligninartige Material (,,Abwehrlignin,,), das in den Zellwänden des Grundgewebes und in den Lumina der Xylemzellen abgelagert wurde, geringe Mengen an Syringyl-(S-Typ)-Lignineinheiten enthielt und sich somit von der normalen Guaiacyl-Syringyl(G-S)-Komposition des Lignins von E. gunnii unterschied. Das S-Typ-Lignin wurde offenbar in den Zellwänden sich entwickelnder sekundärer Xylemzellen abgelagert. Diese Einlagerung erfolgte in einem Stadium, in dem die Zellwände der vergleichbaren Zellen in unverletzten Kontrollstämmen Lignin mit geringem Syringylgehalt enthielten. Der zweite Versuchsansatz zeigte, dass als Reaktion auf die Verletzung zwei verschiedene Arten von Cinnamylalkohol-Dehydrogenase-Aktivitäten induziert und offensichtlich unterschiedlich reguliert werden. Die Aktivität der Coniferyl-Alkohol-Dehydrogenase wurde sofort induziert und sie nahm während 15 Tagen der 17tägigen Versuchsperiode stetig zu, während die Aktivität der Sinapyl-Dehydrogenase erstmals 8 Tage nach der Verletzung nachweisbar war und dann während der gesamten Versuchsperiode anstieg. Die biologische Bedeutung der beiden Alkoholdehydrogenase-Aktivitäten werden in Bezug auf die Bildung von Abwehr-Lignin im Vergleich zur normalen Ligninbildung in Bäumen diskutiert. [source]

    Peter Härtlings Hoffmann Oder Die Vielfältige Liebe: Ein Plädoyer Für Mischa?

    Birgit Röder
    In bislang veröffentlichten Studien zur Biografie E.T.A. Hoffmanns kommt dessen Ehefrau Maria Thekla Michaelina Rorer-Trzcinska eine höchst untergeordnete Rolle zu, und sie wird fast ausschließlich als durch und durch fantasielose Hausfrau aus dem Lager der Philister oder als duldsame leidgeprüfte Gefährtin des großen Exzentrikers gesehen. Im Gegensatz zu dieser Sichtweise, die sich zum Teil in grotesken, wissenschaftlich unhaltbaren Klischeevorstellungen manifestiert, wird in der vorliegenden Arbeit der Versuch unternommen, diese verzerrte Vorstellung von Mischa neu zu überdenken, und bisher ungestellte Fragen nach der Richtigkeit dieser Interpretationsweise aufzuwerfen. Dabei werden einerseits biografische Fakten zu Rate gezogen, andererseits aber auch Hoffmanns Werk, d. h. dessen fiktionale Darstellung von Liebesbeziehungen untersucht. Abschließend folgt eine Analyse von Peter Härtlings ,Romanze'Hoffmann oder Die vielfältige Liebe, in der dem Leser , auf überzeugende, wenngleich auf fiktionale Weise , eine Mischa vorgestellt wird, die wesentlich an Charakter und Persönlichkeit gewinnt. Dabei wird die traditionelle Klischeevorstellung von Hoffmanns Ehefrau, aber ebenso die leidenschaftliche Beziehung Hoffmanns zu seiner Gesangsschülerin Julia Mark, in Frage gestellt. Darüber hinaus bietet Härtling eine herausfordernde Alternative an, indem er beiden Frauen (besonders aber Mischa) eine eigene Stimme bzw. Perspektive gewährt. [source]

    Health state values for the HUI 2 descriptive system: results from a UK survey

    HEALTH ECONOMICS, Issue 3 2005
    Christopher McCabe
    Abstract This paper reports the results of a study to estimate a statistical health state valuation model for a revised version of the Health Utilities Index Mark 2, using Standard Gamble health state preference data. A sample of 51 health states were valued by a sample of the 198 members of the UK general population. Models are estimated for predicting health state valuations for all 8000 states defined by the revised HUI2. The recommended model produces logical and significant coefficients for all levels of all dimensions in the HUI2. These coefficients appear to be robust across model specifications. This model performs well in predicting the observed health state values within the valuation sample and for a separate validation sample of health states. However, there are concerns over large prediction errors for two health states in the valuation sample. These problems must be balanced against concerns over the validity of using the VAS based health state valuation data of the original HUI2 valuation model. Copyright © 2004 John Wiley & Sons, Ltd. [source]

    The role of permanent income and family structure in the determination of child health in Canada

    HEALTH ECONOMICS, Issue 4 2001
    Lori J. Curtis
    Abstract We use data from the Ontario Child Health Study (OCHS) to provide the first Canadian estimates of how the empirical association between child health and both low-income and family status (lone-mother versus two-parent) changes when we re-estimate the model with pooled data. Two waves of data provide a better indication of the family's long-run level of economic resources than does one wave. Our measures of health status include categorical indicators and the health utility score derived from the Health Utilities Index Mark 2 (HUI2) system. Consistent with findings from other countries, we find that most outcomes are more strongly related to low-average income (in 1982 and 1986) than to low-current income in either year. Unlike some previous research, we find the quantitative impact of low-income on child health to be modest to large. Lone-mother status is negatively associated with most outcomes, but the lone-mother coefficients did not change significantly when we switched from low-current income to low-average income. This implies that the lone-mother coefficient in single cross-sections is not just a proxy for low-permanent income. Copyright © 2001 John Wiley & Sons, Ltd. [source]

    Multi-annual dry episodes in Australian climatic variability

    B. G. Hunt
    Abstract The output from a 10 000-year simulation with the CSIRO Mark 2 coupled global climatic model has been analysed to investigate the occurrence of multi-year dry episodes for three selected regions of Australia, specifically, the northeast, southeast and southwest of the continent. Results are presented for dry episodes lasting for 8 or more years. An episode is defined as a time interval having consecutive negative rainfall anomalies, but not necessarily a major drought, for each year of the episode. The hydrological consequences of such an episode can persist for over a century. Typically about 30 episodes are found over the 10 000 years of the simulation for each of the three regions. There is little synchronicity between the regions in the occurrence of the dry episodes. While there is an El Nino/Southern Oscillation (ENSO) influence associated with these episodes, it is not continuous over the duration of an episode. Composites of sea surface temperature anomalies over an episode highlight the limited presence of ENSO events. The occurrence of the dry episodes for all three regions is essentially random, with multi-centennial periods without an episode, and episodes at multi-decadal frequency at other times. Following a discussion of possible mechanistic influences, it is concluded that stochastic forcing is responsible for the occurrence of dry episodes. This implies that there is no predictability associated with the initiation, duration or termination of individual dry episodes. This also suggests that the 2000,2007 dry episodes occurring over much of Australia may not be caused by the greenhouse effect. Such an episode has a return period of between 200 and 300 years based on the mean frequency of occurrence in the present simulation. Copyright © 2008 Royal Meteorological Society [source]

    Making their Mark: Eighteenth-Century Writing-Masters and their Copy-books

    First page of article [source]

    Agreement Between Patient and Proxy Responses of Health-Related Quality of Life After Hip Fracture

    C. Allyson Jones PT
    Objectives: To examine agreement between patient and proxy respondents on health-related quality of life (HRQL) over time during the 6-month recovery after hip fracture. Design: Prospective longitudinal cohort study. Setting: A healthcare region serving Edmonton, Alberta, and the surrounding area. Participants: Two hundred forty-five patients aged 65 and older, were treated for hip fracture, and had Mini-Mental State Examination scores greater than 17; 245 family caregivers participated as proxy respondents. Measurements: Primary outcome was HRQL (Health Utilities Mark 2 and Mark 3). Interviews were completed within 5 days after surgery and at 1, 3, and 6 months. Agreement was evaluated using intraclass correlation coefficients (ICCs). Results: Agreement was considered moderate to excellent for HRQL. ICC values ranged from 0.50 to 0.85 (P<.001) for physically based observable dimensions of health status and from 0.32 to 0.66 (P<.01) for less-observable dimensions. Agreement improved with time. Time and the number of days between patient and proxy interviews were significant factors in accounting for patient,proxy differences. Conclusion: Although proxy and patient responses are not interchangeable, proxy responses provide an option for assessing function and health status in patients who are unable to respond on their own behalf. [source]

    Does the introduction of the Euro have an effect on subjective hypotheses about the price-quality relationship?

    Günter Molz
    Product prices are often considered to be an indicator for quality. In our experiment we focussed on the question if consumers' hypotheses can be biased by exchanging the digits on price displays due to currency changes. We found that high numbers in a price expressed in terms of a currency with a relatively low value (German Mark) lead to a higher perceived quality level than an equivalent price expressed in terms of relatively high listed currency (Euro). Contrary to our expectations we could not prove that this effect is stronger for premium than for low-budget products. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Syntheses of cyclic polycarbonates by the direct phosgenation of bisphenol M,

    Hans R. Kricheldorf
    Abstract Bisphenol M was subjected to interfacial polycondensations in an NaOH/CH2Cl2 system with triethylamine as a catalyst. Regardless of the catalyst concentration, similar molecular weights were obtained, and matrix-assisted laser desorption/ionization time-of-flight mass spectra exclusively displayed mass peaks of cycles (detectable up to 15,000 Da). With triethyl benzyl ammonium chloride as a catalyst, linear chains became the main products, but the contents of the cycles and the molecular weights strongly increased with higher catalyst/bisphenol ratios. When the pseudo-high-dilution method was applied, both diphosgene and triphosgene yielded cyclic polycarbonates of low or moderate molecular weights. Size exclusion chromatography measurements, evaluated with the triple-detection method, yielded bimodal mass distribution curves with polydispersities of 5,12. Furthermore, a Mark,Houwink equation was elaborated, and it indicated that the hydrodynamic volume of poly(bisphenol M carbonate) was quite similar to that of poly(bisphenol A carbonate)s with similar concentrations of cyclic species. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1248,1254, 2005 [source]