Indirect

Distribution by Scientific Domains
Distribution within Life Sciences

Terms modified by Indirect

  • indirect action
  • indirect approach
  • indirect assessment
  • indirect association
  • indirect band gap
  • indirect benefit
  • indirect calorimetry
  • indirect change
  • indirect communication
  • indirect comparison
  • indirect competition
  • indirect consequence
  • indirect contact
  • indirect cost
  • indirect defence
  • indirect detection
  • indirect development
  • indirect effect
  • indirect effects
  • indirect elisa
  • indirect enzyme-linked immunosorbent
  • indirect estimate
  • indirect evidence
  • indirect exciton
  • indirect facilitation
  • indirect genetic benefit
  • indirect immunofluorescence
  • indirect immunofluorescence studies
  • indirect immunohistochemistry
  • indirect impact
  • indirect influence
  • indirect inhibition
  • indirect interaction
  • indirect laryngoscope
  • indirect link
  • indirect marker
  • indirect mean
  • indirect measure
  • indirect measurement
  • indirect mechanism
  • indirect method
  • indirect methods
  • indirect modulation
  • indirect pathway
  • indirect plant defence
  • indirect response
  • indirect response model
  • indirect role
  • indirect selection
  • indirect sign
  • indirect source
  • indirect support
  • indirect test
  • indirect utility function
  • indirect way

  • Selected Abstracts


    Growing Sovereignty: Modeling the Shift from Indirect to Direct Rule

    INTERNATIONAL STUDIES QUARTERLY, Issue 1 2010
    Lars-Erik Cederman
    Drawing on theories of historical sociology, we model the emergence of the territorial state in early modern Europe. Our modeling effort focuses on systems change with respect to the shift from indirect to direct rule. We first introduce a one-dimensional model that captures the tradeoff between organizational and geographic distances. In a second step, we present an agent-based model that features states with a varying number of organizational levels. This model explicitly represents causal mechanisms of conquest and internal state-building through organizational bypass processes. The computational findings confirm our hypothesis that technological change is sufficient to trigger the emergence of modern, direct-state hierarchies. Our theoretical findings indicate that the historical transformation from indirect to direct rule presupposes a logistical, rather than the commonly assumed exponential, form of the loss-of-strength gradient. [source]


    Integrating Transportation Network and Regional Economic Models to Estimate the Costs of a Large Urban Earthquake

    JOURNAL OF REGIONAL SCIENCE, Issue 1 2001
    Sungbin Cho
    In this paper we summarize an integrated, operational model of losses due to earthquake impacts on transportation and industrial capacity, and how these losses affect the metropolitan economy. The procedure advances the information provided by transportation and activity system analysis techniques in ways that help capture the most important ecomonic implications of earthquakes. Network costs and origin-destination requirements are modeled endogenously and consistently. Indirect and induced losses associated with direct impacts on transportation and industrial capacity are distributed across zones and ecomonic sectors. Preliminary results are summarized for a magnitude 7.1 earthquake on the Elysian Park blind thrust fault in Los Angeles. [source]


    Systematic review: the costs of ulcerative colitis in Western countries

    ALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 7 2010
    R. D. COHEN
    Aliment Pharmacol Ther,31, 693,707 Summary Background, Early onset and complications such as hospitalization and surgery contribute to the economic burden of ulcerative colitis. Aim, To review systematically the literature on costs of ulcerative colitis in Western countries. Methods, Studies estimating costs of ulcerative colitis in Western countries were identified using Medline, EMBASE and ISI Web of Science and were rated based on relevance and reliability of estimates. All costs were adjusted to 2008 currency values. A parallel review focused on the impact of disease severity on costs, hospitalizations and surgeries. Results, Estimated annual per-patient direct medical costs of ulcerative colitis ranged from $6217 to $11 477 in the United States and from ,8949 to ,10 395 in Europe. Hospitalizations accounted for 41,55% of direct medical costs. Indirect costs accounted for approximately one-third of total costs in the United States and 54,68% in Europe. Total economic burden of ulcerative colitis was estimated at $8.1,14.9 billion annually in the United States and at ,12.5,29.1 billion in Europe; total direct costs were $3.4,8.6 billion in the United States and ,5.4,12.6 billion in Europe. Direct costs, hospitalizations and surgeries increased with worsening disease severity. Conclusions, Ulcerative colitis is a costly disease. Hospitalizations contribute significantly to direct medical costs, and indirect costs are considerable, having previously been substantially underestimated. [source]


    Indirect Re,employment Wage Discrimination

    BULLETIN OF ECONOMIC RESEARCH, Issue 1 2003
    Kostas G. Mavromaras
    This paper looks at unemployed individuals and investigates wage differences generated by re,employment selection. It shows that discriminatory re,employment selection can result, indirectly, in discriminatory re,employment pay. A Heckman two,stage selection model is combined with an extension of Gomulka,Stern non,linear decompositions to explain how re,employment selection generates indirect discrimination. The paper uses data from pre,unification Germany in the late 1980s and finds that female human capital suffers more from unemployment and that the market is harsher to males for becoming unemployed. New policies should encourage a regime where the hiring process is more transparent and hiring decisions are monitored on a regular basis. [source]


    An Adaptive Method for Indirect Illumination Using Light Vectors

    COMPUTER GRAPHICS FORUM, Issue 3 2001
    Xavier Serpaggi
    In computer graphics, several phenomema need to be taken into account when it comes to the field of photo-realism. One of the most relevant is obviously the notion of global, and more precisely indirect, illumination. In "classical" ray-tracing if you are not under the light, then you are in a shadow. A great amount of work has been carried out which proposes ray-tracing based solutions to take into account the fact that "there is a certain amount of light in shadows". All of these methods carry the same weaknesses: high computation time and a lot of parameters you need to manage to get something out of the method. This paper proposes a generic computation method of indirect illumination based on Monte Carlo sampling and on the sequential analysis theory, which is faster and more automatic than classical methods. [source]


    Temperature-tuned band gap energy and oscillator parameters of Tl2InGaSe4 semiconducting layered single crystals

    CRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2009
    N. M. Gasanly
    Abstract The optical properties of Tl2InGaSe4 layered single crystals have been studied through the transmission and reflection measurements in the wavelength range of 500-1100 nm. The analysis of room temperature absorption data revealed the presence of both optical indirect and direct transitions with band gap energies of 1.86 and 2.05 eV, respectively. Transmission measurements carried out in the temperature range of 10-300 K revealed that the rate of change of the indirect band gap with temperature is , = , 4.4 × 10 -4 eV/K. The absolute zero value of the band gap energy was obtained as Egi(0) = 1.95 eV. The dispersion of the refractive index is discussed in terms of the single oscillator model. The refractive index dispersion parameters: oscillator wavelength and strength were found to be 2.53 × 10,7 m and 9.64 × 1013 m,2, respectively. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]


    Postoperative discomfort associated with surgical and nonsurgical endodontic retreatment

    DENTAL TRAUMATOLOGY, Issue 2 2000
    T. Kvist
    Abstract , Endodontic retreatment decision-making must include an appraisal of the costs of the different strategies proposed. In addition to direct costs, postoperative discomfort may have other consequences in terms of time off work, unscheduled visits and suffering. To establish a foundation for the appraisal of such indirect and intangible costs the present study was set up in which patients' assessments of pain and swelling after surgical and nonsurgical retreatment procedures were recorded. Ninety-two patients with 95 root-filled incisors and canine teeth exhibiting apical periodontitis were included in the study. The mode of retreatment was randomly assigned. Each day during the first post-treatment week patients assessed their degree of swelling and pain on horizontal 100-mm visual analog scales (VAS). The scales ranged from "no swelling" to "very severe swelling" and "no pain" to "intolerable pain", respectively. Consumption of self-prescribed analgesics and time off work were also recorded. Significantly more patients reported discomfort after surgical retreatment than after nonsurgical procedures. High pain scores were most frequent on the operative day while swelling reached its maximum on the first postoperative day followed by progressive decrease both in frequency and magnitude. Postoperative symptoms associated with nonsurgical retreatment were less frequent but reached high VAS values in single cases. Analgesics were significantly more often consumed after periapical surgery. Patients reported absence from work mainly due to swelling and discoloration of the skin. This was found to occur only after surgical retreatment. Conclusively, surgical retreatment resulted in more discomfort and tended to bring about greater indirect costs than nonsurgical retreatment. [source]


    Direct and indirect time spent on care of dental trauma: a 2-year prospective study of children and adolescents

    DENTAL TRAUMATOLOGY, Issue 1 2000
    U. Glendor
    Abstract , The aim was to account for the total time spent by professional care-givers (direct time) and by patients and companions engaged as support and help (indirect time) to treat and otherwise attend to children and adolescents with dental trauma to primary and permanent teeth. The study was based on a random sample of 192 children and adolescents with dental traumas reported to an insurance company and prospectively followed up by telephone interviews over a period of 2 years after the trauma episode. On average, direct time represented 16% of total time for all visits for dental trauma to permanent teeth and 11% for trauma to primary teeth. The most extensive type of indirect time was transport time, which took up 30% of the total time spent on injuries to permanent teeth and 36% for injuries to primary teeth. Multiple regression analysis of the impact of dental and demographic injury variables on the time variables showed that complicated trauma was associated with extended time, direct as well as indirect, for permanent and primary teeth injuries. Our estimate of the average relative increase in total time spent by patients and companions in cases of complicated injury to permanent teeth was 117% (95% confidence interval [CI], 52,211) for patients and 112% (95% CI, 42,217) for companions. For transport time a strong predictor was access to a dental clinic near the place of residence. Lack of access could extend the average transport time by 180% (95% CI, 80,335) for patients and 163% (95% CI, 67,317) for their companions in cases of injuries to primary teeth. [source]


    Small and Medium-Sized Congenital Nevi in Children: A Comparison of the Costs of Excision and Long-Term Follow-Up

    DERMATOLOGIC SURGERY, Issue 12 2009
    FERNANDO ALFAGEME ROLDÁN MD
    BACKGROUND Clinical decisions on whether to follow up or remove small and medium congenital melanocytic nevi (SMCMN) in children have cost implications that have not been studied. OBJECTIVES To compare the costs of excision of SMCMN in children with lifelong follow-up in a tertiary center. METHODS AND MATERIALS We elaborated models for the evaluation of the costs of excision and long-term follow-up. We retrospectively collected data on 113 consecutive excised SMCMN (105 single-step interventions and 8 multiple-step interventions) from the medical records of our pediatric dermatology unit from 2001 to 2007 and calculated and compared the costs (direct and indirect) of surgery and follow-up. RESULTS The mean ± standard deviation and total cohort costs for single-step interventions were ,1,504.73 ± 198.33 and 157,996.20, respectively. Median and cohort lifelong follow-up costs were similar if performed every 4 years (1,482.66 ± 34.98 and 156,679.63). For multiple-step interventions (3 or 4 steps), surgery costs were similar to those of annual lifelong follow-up. In the case of two-step surgery, costs were similar to lifelong follow-up every 2 years. CONCLUSIONS An analysis of the costs of surgery and long-term follow-up in children with SMCMN is possible. Although the clinical judgment of the dermatologist and parental opinion are the main determinants in the management of SMCMN, costs should also be taken into account. [source]


    Transient expression of thyroid hormone nuclear receptor TR,2 sets S opsin patterning during cone photoreceptor genesis

    DEVELOPMENTAL DYNAMICS, Issue 5 2007
    M.L. Applebury
    Abstract Cone photoreceptors in the murine retina are patterned by dorsal repression and ventral activation of S opsin. TR,2, the nuclear thyroid hormone receptor , isoform 2, regulates dorsal repression. To determine the molecular mechanism by which TR,2 acts, we compared the spatiotemporal expression of TR,2 and S opsin from embryonic day (E) 13 through adulthood in C57BL/6 retinae. TR,2 and S opsin are expressed in cone photoreceptors only. Both are transcribed by E13, and their levels increase with cone genesis. TR,2 is expressed uniformly, but transiently, across the retina. mRNA levels are maximal by E17 at completion of cone genesis and again minimal before P5. S opsin is also transcribed by E13, but only in ventral cones. Repression in dorsal cones is established by E17, consistent with the occurrence of patterning during cone cell genesis. The uniform expression of TR,2 suggests that repression of S opsin requires other dorsal-specific factors in addition to TR,2. The mechanism by which TR,2 functions was probed in transgenic animals with TR,2 ablated, TR,2 that is DNA binding defective, and TR,2 that is ligand binding defective. These studies show that TR,2 is necessary for dorsal repression, but not ventral activation of S opsin. TR,2 must bind DNA and the ligand T3 (thyroid hormone) to repress S opsin. Once repression is established, T3 no longer regulates dorsal S opsin repression in adult animals. The transient, embryonic action of TR,2 is consistent with a role (direct and/or indirect) in chromatin remodeling that leads to permanent gene silencing in terminally differentiated, dorsal cone photoreceptors. Developmental Dynamics 236:1203,1212, 2007. © 2007 Wiley-Liss, Inc. [source]


    Testing neural models of the development of infant visual attention

    DEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2002
    John E. Richards
    Abstract Several models of the development of infant visual attention have used information about neural development. Most of these models have been based on nonhuman animal studies and have relied on indirect measures of neural development in human infants. This article discusses methods for studying a "neurodevelopmental" model of infant visual attention using indirect and direct measures of cortical activity. We concentrate on the effect of attention on eye movement control and show how animal-based models, indirect measurement in human infants, and direct measurement of brain activity inform this model. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 226,236, 2002. DOI 10.1002/dev.10029 [source]


    Effects of insulin resistance on endothelial function: possible mechanisms and clinical implications

    DIABETES OBESITY & METABOLISM, Issue 10 2008
    D Tousoulis
    Insulin resistance (IR) is defined as a reduced responsiveness of peripheral tissues to the effects of the hormone, referring to abated ability of insulin in stimulating glucose uptake in peripheral tissues and in inhibiting hepatic glucose output. Insulin has both a vasodilatory effect, which is largely endothelium dependent through the release of nitric oxide, and a vasoconstrictory effect through the stimulation of the sympathetic nervous system and the release of endothelin-1. IR and endothelial dysfunction (ED) are not only linked by common pathogenetic mechanisms, involving deranged insulin signalling pathways, but also by other, indirect to the hormone's actions, mechanisms. Different treatment modalities have been proposed to affect positively both the metabolic effects of insulin and ED. Weight loss has been shown to improve sensitivity to insulin as a result of either altered diet or exercise. Exercise has favourable effects on endothelial function in normal states and in states of disease, in men and women, and throughout the age spectrum and, hence, in IR states. Metformin improves sensitivity to insulin and most likely affects positively ED. Studies have shown that inhibitors of the renin,angiotensin system alter IR favourably, while Angiotensin converting enzyme (ACE) inhibitors and Angiotensin receptor type II (ATII) inhibitors improve ED. Ongoing studies are expected to shed more light on the issue of whether treatment with the thiazolidinediones results in improvement of endothelial function, along with the accepted function of improving insulin sensitivity. Finally, improved endothelial function by such treatments is not in itself proof of reduced risk for atherosclerosis; this remains to be directly tested in clinical trials. [source]


    Effectiveness of screening and monitoring tests for diabetic retinopathy , a systematic review

    DIABETIC MEDICINE, Issue 7 2000
    A. Hutchinson
    SUMMARY Aims To determine which screening and monitoring tests for diabetic retinopathy are most effective and under what circumstances. Methods A systematic review of the English language literature, published from 1983 to April 1999. Results Available studies are generally limited in their ability to answer the important questions on the effectiveness of tests for early detection of diabetic retinopathy. No randomized controlled trials were identified although primary studies exist for two screening tests: ophthalmoscopy, either direct or indirect, and retinal photography, using either mydriasis or non-mydriasis. Retinal photography under mydriasis appears to be the most effective test, with the majority reporting levels of sensitivity in excess of 80%. However effectiveness is compromised when photographs are ungradable. Ophthalmoscopy can also reach acceptable standards of sensitivity and specificity. Conclusion Based on an assessment of available cohort studies, the most effective strategy for testing is the use of mydriatic retinal photography with the additional use of ophthalmoscopy for cases where photographs are ungradable. This does not exclude the use of ophthalmoscopy alone for opportunistic case finding but there is evidence of considerable variation in effectiveness of this test. [source]


    Climate, climate change and range boundaries

    DIVERSITY AND DISTRIBUTIONS, Issue 3 2010
    Chris D. Thomas
    Abstract Aim, A major issue in ecology, biogeography, conservation biology and invasion biology is the extent to which climate, and hence climate change, contributes to the positions of species' range boundaries. Thirty years of rapid climate warming provides an excellent opportunity to test the hypothesis that climate acts as a major constraint on range boundaries, treating anthropogenic climate change as a large-scale experiment. Location, UK and global data, and literature. Methods, This article analyses the frequencies with which species have responded to climate change by shifting their range boundaries. It does not consider abundance or other changes. Results, For the majority of species, boundaries shifted in a direction that is concordant with being a response to climate change; 84% of all species have expanded in a polewards direction as the climate has warmed (for the best data available), which represents an excess of 68% of species after taking account of the fact that some species may shift in this direction for non-climatic reasons. Other data sets also show an excess of animal range boundaries expanding in the expected direction. Main conclusions, Climate is likely to contribute to the majority of terrestrial and freshwater range boundaries. This generalization excludes species that are endemic to specific islands, lakes, rivers and geological outcrops, although these local endemics are not immune from the effects of climate change. The observed shifts associated with recent climate change are likely to have been brought about through both direct and indirect (changes to species' interactions) effects of climate; indirect effects are discussed in relation to laboratory experiments and invasive species. Recent observations of range boundary shifts are consistent with the hypothesis that climate contributes to, but is not the sole determinant of, the position of the range boundaries of the majority of terrestrial animal species. [source]


    Health Status among Emergency Department Patients Approximately One Year after Consecutive Disasters in New York City

    ACADEMIC EMERGENCY MEDICINE, Issue 10 2005
    William George Fernandez MD
    Abstract Objectives: Emergency department (ED) patients with disaster-related experiences may present with vague symptoms not clearly linked to the event. In 2001, two disasters in New York City, the World Trade Center disaster (WTCD) and the subsequent American Airlines Flight 587 crash, presented an opportunity to study long-term consequences of cumulative disaster exposure (CDE) on health-related quality of life (HRQOL) among ED patients. Methods: From July 15 to October 30, 2002, a systematic sample of stable, adult patients from two EDs in New York City were enrolled. Participants completed a self-administered questionnaire. The Short Form 36 (SF-36) was used to assess overall health status. Bivariate analyses were conducted to identify individual correlates of worsening health status. Multivariate regression was performed to identify the association between various factors and overall health status, while controlling for relevant sociodemographic variables. Results: Four hundred seventy-one patients (54.6% female) participated. The participation rate was 73.4%. One hundred sixty-one participants (36%) reported direct, indirect, or occupational exposure to the WTCD; 55 (13.3%) had direct, indirect, or occupational exposure to the plane crash; 33 (8.1%) had both exposures. In separate multivariate models, CDE predicted lower SF-36 scores for general health (p < 0.0096), mental health (p < 0.0033), and bodily pain (p < 0.0046). Conclusions: In the year following mass traumatic events, persons with CDE had lower overall health status than those with one or no disaster exposure. Clinicians should consider the impact that traumatic events have on the overall health status of ED patients in the wake of consecutive disasters. [source]


    Textural and compositional controls on modern beach and dune sands, New Zealand

    EARTH SURFACE PROCESSES AND LANDFORMS, Issue 3 2007
    J. J. Kasper-Zubillaga
    Abstract Textural, compositional, physical and geophysical determinations were carried out on 111 beach and dune sand samples from two areas in New Zealand: the Kapiti,Foxton coast sourced by terranes of andesite and greywackes and the Farewell Spit,Wharariki coast sourced by a wide variety of Paleozoic terranes. Our aim is to understand how long-shore drift, beach width and source rock control the sedimentological and petrographic characteristics of beach and dune sands. Furthermore, this study shows the usefulness of specific minerals (quartz, plagioclase with magnetite inclusions, monomineralic opaque grains) to interpret the physical processes (fluvial discharges, long-shore currents, winds) that distribute beach and dune sands in narrow and wide coastal plains. This was done by means of direct (grain size and modal analyses) and indirect (specific gravity, magnetic/non-magnetic separations M/NM, magnetic susceptibility measurements, hysteresis loops) methods. Results are compared with beach sands from Hawaii, Oregon, the Spanish Mediterranean, Elba Island and Southern California. Compositionally, the Kapiti,Foxton sands are similar to first-order immature sands, which retain their fluvial signature. This results from the high discharge of rivers and the narrow beaches that control the composition of the Kapiti,Foxton sands. The abundance of feldspar with magnetite inclusions controls the specific gravity of the Kapiti,Foxton sands due to their low content of opaque minerals and coarse grain size. Magnetic susceptibility of the sands is related mainly to the abundance of feldspars with Fe oxides, volcanic lithics and free-opaque minerals. The Farewell Spit,Wharariki sands are slightly more mature than the Kapiti,Foxton sands. The composition of the Farewell Spit,Wharariki sands does not reflect accurately their provenance due to the prevalence of long-shore drift, waves, little river input and a wide beach. Low abundance of feldspar with magnetite inclusions and free opaque grains produces poor correlations between specific gravity (Sg) and Fe oxide bearing minerals. The small correlation between opaque grains and M/NM may be related to grain size. The magnetic susceptibility of Farewell Spit,Wharariki sands is low due to the low content of grains with magnetite inclusions. Hysteresis and isothermal remnant magnetization (IRM) agree with the magnetic susceptibility values. Copyright © 2006 John Wiley & Sons, Ltd. [source]


    Conspicuous extra-floral nectaries are inducible in Vicia faba

    ECOLOGY LETTERS, Issue 6 2003
    Edward B. Mondor
    Abstract Mutualistic interactions are dynamic associations that vary depending on the costs and benefits to each of the interacting parties. Phenotypic plasticity in mutualistic interactions allows organisms to produce rewards to attract mutualists when the benefits of their presence outweigh the costs of producing the rewards. In ant,plant defensive mutualisms, defences are indirect as plants produce extra-floral nectaries (EFN) to attract predatory ants to deter herbivores. Here we demonstrate that in broad bean, Vicia faba, the overall number of EFNs on a plant increases dramatically following leaf damage. In two damage treatments, removal of: (1) one-third of one leaf in a single leaf pair or (2) one-third of both halves of a single leaf pair, resulted in a 59 and 106% increase in the number of EFNs on the plants, respectively, over 1 week. We suggest that the increased production of visually conspicuous EFNs is an adaptive inducible response, to attract predatory arthropods when risk of herbivory increases. [source]


    Effects of parasitoid fecundity and host resistance on indirect interactions among hosts sharing a parasitoid

    ECOLOGY LETTERS, Issue 6 2003
    George E. Heimpel
    Abstract We examine the effects of fecundity-limited attack rates and resistance of hosts to parasitism on the dynamics of two-host,one-parasitoid systems. We focus primarily on the situation where one parasitoid species attacks two host species that differ in their suitability for parasitism. While all eggs allocated to suitable hosts develop into adult parasitoids, some of the eggs allocated to marginal host do not develop. Marginal hosts can therefore act as a sink for parasitoid eggs. Three-species coexistence is favoured by low levels of parasitoid fecundity and by low levels of suitability of the marginal host. Our model also produces an indirect (+, ,) interaction in which the suitable host can benefit from the presence of the marginal host, but the marginal host suffers from the presence of the suitable host. The mechanism driving the indirect (+, ,) interaction is egg limitation of parasitoids incurred by allocating eggs to marginal hosts. [source]


    Top-down and bottom-up diversity cascades in detrital vs. living food webs

    ECOLOGY LETTERS, Issue 1 2003
    Lee A. Dyer
    Abstract Apex predators and plant resources are both critical for maintaining diversity in biotic communities, but the indirect (,cascading') effects of top-down and bottom-up forces on diversity at different trophic levels are not well resolved in terrestrial systems. Manipulations of predators or resources can cause direct changes of diversity at one trophic level, which in turn can affect diversity at other trophic levels. The indirect diversity effects of resource and consumer variation should be strongest in aquatic systems, moderate in terrestrial systems, and weakest in decomposer food webs. We measured effects of top predators and plant resources on the diversity of endophytic animals in an understorey shrub Piper cenocladum (Piperaceae). Predators and resource availability had significant direct and indirect effects on the diversity of the endophytic animal community, but the effects were not interactive, nor were they consistent between living vs. detrital food webs. The addition of fourth trophic level beetle predators increased diversity of consumers supported by living plant tissue, whereas balanced plant resources (light and nutrients) increased the diversity of primary through tertiary consumers in the detrital resources food web. These results support the hypotheses that top-down and bottom-up diversity cascades occur in terrestrial systems, and that diversity is affected by different factors in living vs. detrital food webs. [source]


    Fish assemblages as influenced by environmental factors in streams in protected areas of the Czech Republic

    ECOLOGY OF FRESHWATER FISH, Issue 1 2006
    M. Humpl
    Abstract,,, Three streams of comparable size located in different landscape-protected areas were selected for studying the effect of environmental factors on fish assemblages using indirect (detrended correspondence analysis, DCA) and direct (canonical correspondence analysis, CCA) gradient analysis. DCA of species showed well a gradient of assemblage changes in the longitudinal profile. DCA of sites stressed the variability between the fish assemblages of the three streams. This pattern was then confirmed by the highly significant between-stream CCA. In the within-site CCA, environmental factors explained 50.7% variability for presence,absence data and 58.3% for the relative abundance data. The analysis revealed that number of ponds and land use are the most influential factors of the strongest environmental gradient. However, in the partial CCAs, factor substratum type explained the largest proportion of the variability affecting fish in their habitat choice. Generally, presence,absence and relative abundance data of fish gave similar results in both DCA and CCA analyses; the same environmental factors proved to be important in both data type analyses. The environmental factors explain more variability than the regional (between-stream) one. The total proportion of variability explained by the presence,absence data analysis was 71.9% and in the relative abundance analysis even 80.8%. The environmental factors measured during the field survey explain 2.1- and 3.4-times more assemblages' variability than factors measured from a hydrological map. Resumen 1. Tres ríos de tamaño comparable localizados en diferentes áreas de paisaje protegido de la República Checa fueron seleccionados para estudiar el efecto de factores ambientales sobre los ensamblajes de peces. Para ello, utilizando análisis de gradientes indirectos (DCA) y directos (CCA). 2. El DCA para las especies enfatizó la variabilidad entre los ensamblajes de peces de los tres ríos. Este patrón fue confirmado por un CCA altamente significativo. Para la variabilidad dentro de la localidad, un CCA reveló que los factores ambientales explicaron un 50.7% para datos de presencia-ausencia y un 58.3% para las abundancias relativas. 3. Los análisis revelaron que el número de pozas y el uso del suelo fueron los factores de mayor influencia en el gradiente ambiental. Sin embargo, en el CCA parcial, el tipo de sustrato explicó la mayor proporción de la variabilidad que afecta a los peces en la elección de hábitat. 4. Generalmente los datos de presencia-ausencia y abundancia relativa produjeron resultados similares tanto en los análisis DCA como en los CCA; los mismos factores ambientales probaron ser importantes en los análisis de ambos tipos de datos. Los factores ambientales explicaron mas variabilidad que los regionales (entre ríos). La proporción total de variabilidad explicada por el análisis de los datos de presencia-ausencia fue 71.9% mientras que para las abundancias relativas fue de 80.8%. Los factores ambientales medidos durante los muestreos de campo explicaron 2.1 y 3.4 veces mas variabilidad que los factores medidos sobre mapas hidrológicos. [source]


    Labour market implications of EU product market integration

    ECONOMIC POLICY, Issue 30 2000
    Torben M. Andersen
    European labour markets are in a state of flux due to the changing market situation induced by international integration. This process affects wage formation through more fierce product market competition and increased mobility of jobs. This development is by some observers taken to enforce labour market flexibility, while for others it signals an erosion of social standards and in turn possibly the welfare society. Since labour is not very mobile in Europe, the effects of international integration on labour markets are mostly indirect via product market integration. We review the channels through which product market integration affects labour markets and perform an empirical analysis of the convergence and interdependencies in wage formation among EU countries. We find that integration is changing labour market structures and inducing wage convergences as well as stronger wage interdependencies, but it is a gradual process. Moreover, the present study does not support the view that international integration will lead to a ,race to the bottom' and rapidly erode domestic labour markets standards, nor that it will relieve politicians of the need to consider labour market reforms to improve labour market performance. [source]


    Electrophoretically mediated microanalysis with partial filling technique and indirect or direct detection as a tool for inhibition studies of enzymatic reaction

    ELECTROPHORESIS, Issue 7-8 2004
    Magdaléna Telnarová
    Abstract The inhibition of the model enzyme, haloalkane dehalogenase from Sphingomonas paucimobilis, was investigated by a combination of electrophoretically mediated microanalysis with a partial filling technique, followed by indirect or direct detection. In this setup, part of the capillary is filled with a buffer suitable for the enzymatic reaction (20 mM glycine buffer, pH 8.6) whereas the rest of the capillary is filled with the background electrolyte optimal for separation of substrates and products. Two different background electrolytes and corresponding detection approaches were used to show the versatility of the developed method. The inhibition effect of 1,2-dichloroethane on the dehalogenation of brominated substrate 1-bromobutane was studied by means of 10 mM chromate , 0.1 mM cetyltrimethylammonium bromide (pH 9.2) in combination with indirect detection or 20 mM ,-alanine , hydrochloric acid (pH 3.5) in combination with direct detection. The method was used to estimate the inhibition constant KI (0.44 mM by indirect detection and 0.63 mM by of direct detection) and to determine the inhibition type. Compared to spectrophotometric and other discontinuous assays, the method is rapid, can be automated, and requires only small amount of reagents that is especially important in the case of enzymes and inhibitors. [source]


    Pathways to cannabis abuse: a multi-stage model from cannabis availability, cannabis initiation and progression to abuse

    ADDICTION, Issue 3 2009
    Nathan A. Gillespie
    ABSTRACT Aims Although previous twin studies have modeled the association between drug initiation and abuse, none has included the obvious risk factor of drug availability. Our aim is to determine whether the genetic and environmental risk factors for cannabis availability also generate variation in cannabis initiation and/or progression to DSM-IV symptoms of abuse. Design We used multi-stage modeling, also known as causal-common-contingent (CCC) analysis, to partition the genetic and environmental factors into common and stage-specific components. Participants This report is based on data collected from 1772 adult males from the Mid Atlantic Twin Registry. Measurements The twins participated in two structured interviews which included clinical and non-clinical measures of cannabis abuse as well as retrospective assessments of perceived cannabis availability between ages 8 and 25 years. Findings Cannabis availability explained almost all the shared environmental risks in cannabis initiation and abuse. The influence of availability on the symptoms of abuse was indirect and mediated entirely by cannabis initiation. Conclusion These findings have begun to elucidate the causal processes underlying the liability to drug use and abuse in terms of putative risk factors. Specifically, our results show that the latent shared environmental factors in cannabis initiation and abuse can be explained by measured aspects of the shared environment,those responsible for variation in cannabis availability. [source]


    Impact of a benzoyl urea insecticide on aquatic macroinvertebrates in ditch mesocosms with and without non-sprayed sections,

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2009
    Theo C.M. Brock
    Abstract The long-term response, including recovery, of aquatic macroinvertebrates to short-term insecticide exposure may be affected by the presence of uncontaminated refuges in the stressed ecosystem. Experimental ditches were used to study the influence of non-sprayed ditch sections regarding the ecotoxicological effects on and the recovery of macroinvertebrates following treatment with the insecticide lufenuron. The treatment regimes differed in the proportion of the ditch (0, 33, 67, and 100% of surface area) that was sprayed to reach a lufenuron concentration of 3 ,/L in the water column of the sprayed ditch section. The magnitude and duration of effects on macroinvertebrates, and on arthropods in particular, were higher when a larger proportion of the ditch was treated. Initially, more pronounced responses were observed for bivoltine and multivoltine insects and macrocrustaceans than for univoltine and semivoltine arthropods. Most macroinvertebrate arthropods showed delayed responses, with maximum treatment-related effects observed two to six weeks after lufenuron application. This latency of effects can be explained by the mode of action of lufenuron, involving inhibition of chitin synthesis, which affects arthropod molting and metamorphosis. The observed effects were short-lived only in those ditches where 33% of the surface area was sprayed. In the ditches where 67 and 100% of the surface area was sprayed, some insects and macrocrustaceans showed long-term effects. In the 100% sprayed ditches in particular, the treatment-related reduction in arthropods resulted in indirect effects, such as an increase in snails, and later in an increase in the ephemeropteran Cloeon dipterum, probably because of an increase in periphyton, and release from competition and predation. Effects that are most likely indirect also were observed for Oligochaeta, Hirudinea, and the flatworm Mesostoma sp. [source]


    Does subtle screening for substance abuse work?

    ADDICTION, Issue 1 2007
    A review of the Substance Abuse Subtle Screening Inventory (SASSI)
    ABSTRACT Aim Through a complex combination of direct (face-valid) and indirect (subtle) subscales, the Substance Abuse Subtle Screening Inventory (SASSI) is purported to detect substance use disorders with a high degree of validity regardless of respondent honesty or motivation. This review evaluates empirical evidence regarding the reliability and validity of this widely used screening instrument. Methods Source documents were 36 peer-reviewed reports yielding data regarding the SASSI's internal consistency, test,retest reliability, psychometric structure, convergent and divergent validity and criterion (predictive) validity. Results The total N of the studies reviewed equaled 22 110. Internal consistency is high for the overall SASSI and for its direct but not its indirect (subtle) subscales, suggesting that the instrument taps a single face-valid construct. SASSI classifications converged with those from other direct screening instruments, and were also correlated with ethnicity, general distress and social deviance. Studies found test,retest reliability lower than that reported in the test manuals. Sensitivity was found to be similar to that for public domain screening instruments, but on specificity the SASSI appears to yield a high rate of false positives. Conclusion No empirical evidence was found for the SASSI's claimed unique advantage in detecting substance use disorders through its indirect (subtle) scales to circumvent respondent denial or dishonesty. Recommendations for screening and for future research with the SASSI are offered. [source]


    Biological measurement of estrogenic activity in urine and bile conjugates with the in vitro ER-CALUX reporter gene assay

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2002
    Juliette Legler
    Abstract Although estrogens are excreted as biologically inactive conjugates, they can be reconverted to an active form, possibly by bacteria. A simple method was developed to deconjugate estrogen metabolites present in human urine and fish bile back to active estrogens by enzymatic hydrolysis with ,-glucuronidase or live Escherichia coli cells. Deconjugated extracts were tested for estrogenic activity in the in vitro stable estrogen receptor,mediated chemical-activated luciferase gene expression (ER-CALUX) assay. Estrogen glucuronides in urine obtained from human males and females were effectively converted to active forms after incubation with ,-glucuronidase or E. coli. The highest estrogenic activity was found in deconjugated metabolites from urine of a pregnant woman, in which levels up to 3,000 nmol estradiol equivalents per liter of urine were found after overnight incubation of urine with E. coli. Bile sampled from male bream and flounder from various freshwater and marine locations was also deconjugated and a good correlation was found between high biliary estrogenic activity and elevated levels of xenoestrogenic activity in surface water as well as in plasma vitellogenin. Therefore, the measurement of deconjugated bile could form a useful (indirect) biomarker for internal dose of xenoestrogens in male fish. [source]


    Effect of mercury and Gpi-2 genotype on standard metabolic rate of eastern mosquitofish (Gambusia holbrooki),

    ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2001
    Christopher Paul Tatara
    Abstract Previous studies demonstrated differential mortality among mosquitofish of different Gpi-2 genotypes during acute mercury and arsenate exposures. Mercury-exposed mosquitofish also had Gpi-2 genotype-specific differences in glycolytic and Krebs cycle metabolite pools. The mortality and metabolite data suggested that mosquitofish bearing specific Gpi-2 genotypes might differ in metabolic efficiency, with less efficient Gpi-2 genotypes having higher standard metabolic rates (SMRs) and shorter times to death during acute mercury exposure. Effect of Gpi-2 genotype on SMR was assessed with a factorial arrangement of six Gpi-2 genotypes and two exposure sequences (Control , Control; Control , 100 ,g/L Hg). The SMRs were estimated by measuring oxygen consumption using an indirect, closed-circuit, computer-controlled respirometer. A 48-h exposure to 100 ,g/L of mercury resulted in a 16.7% elevation of SMR above control levels (p = 0.001). The Gpi-2 genotype and the number of heterozygous loci per individual had no significant effect on SMR in mercury-exposed mosquitofish. The experimental results do not support the hypothesis that Gpi-2 genotype-specific differences in glycolytic and Krebs cycle metabolite pools and mortality in mosquitofish exposed to mercury are associated with differences in SMR. [source]


    Cross-Country Measures for Monitoring Epilepsy Care

    EPILEPSIA, Issue 5 2007
    Charles E. Begley
    Summary:,Purpose: The International League Against Epilepsy (ILAE) Commission on Healthcare Policy in consultation with the World Health Organization (WHO) examined the applicability and usefulness of various measures for monitoring epilepsy healthcare services and systems across countries. The goal is to provide planners and policymakers with tools to analyze the impact of healthcare services and systems and evaluate efforts to improve performance. Methods: Commission members conducted a systematic literature review and consulted with experts to assess the nature, strengths, and limitations of the treatment gap and resource availability measures that are currently used to assess the adequacy of epilepsy care. We also conducted a pilot study to determine the feasibility and applicability of using new measures to assess epilepsy care developed by the WHO including Disability-Adjusted Life Years (DALYs), responsiveness, and financial fairness. Results: The existing measures that are frequently used to assess the adequacy of epilepsy care focus on structural or process factors whose relationship to outcomes are indirect and may vary across regions. The WHO measures are conceptually superior because of their breadth and connection to articulated and agreed upon outcomes for health systems. However, the WHO measures require data that are not readily available in developing countries and most developed countries as well. Conclusion: The epilepsy field should consider adopting the WHO measures in country assessments of epilepsy burden and healthcare performance whenever data permit. Efforts should be made to develop the data elements to estimate the measures. [source]


    A student learning perspective on teaching and learning, with implications for problem-based learning

    EUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 2 2004
    Michael Prosser
    Over the last 20 years or so, there has been a substantial development in our understanding of how and what university students learn in their courses (here meaning a component of a programme) and programmes of study. This research has shown that rather than there being a direct connection between the way teachers teach and design their courses, and the quality of their students' learning outcomes, the relationship is indirect. The way students perceive and understand their learning context and the way they approach their learning in relationship to these perceptions have been found to be major intervening factors between teachers' teaching and students' learning outcomes. Their perceptions are, in turn, constituted in relation to their prior experiences of teaching and learning and what is designed for them to learn. In this paper, some of the key findings of this research and how it can be related to a problem-based learning (PBL) perspective in higher education are outlined. In particular, it is argued that the variation in students' perceptions and understanding of what PBL is about is fundamental to the way they approach their studies and to their learning outcomes. [source]


    Testing of fine motor skills in dental students

    EUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 1 2000
    Olaf Luck
    Manual skills form only a part of the capabilities required of future dentists, but they are a very important component, which should be tested. With regard to the dental specialities, the present study tested speciality-independent fine motor skills. No objective, practical solution has been found up to now. 88 dental students and, as a control group, 23 medical students were examined in the longitudinal study. In the course of the analysis, 4 fine motor tests were carried out at the beginning of the 2nd and 6th semesters. The tests comprised the tremometer test, the tremometer test with a mirror, the 2-hand sinusoid test and archery using the Game Gear by SEGA. The test devices facilitate primarily the testing of components of accuracy of movements, indirect working methods, and eye-hand coordination. In the comparison of performances on test day A, the medical students' performance was noticeably better. As testing progressed, results showed stagnation in the performance of the medical students and a significant improvement in the performance of the dental students. That means that the test system can be used for a test over the course of study, but not as an initial test. [source]