Affecting

Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Affecting

  • factor affecting


  • Selected Abstracts


    INTERNATIONAL INTER-LABORATORY TRIALS TO DETERMINE THE FACTORS AFFECTING THE MEASUREMENT OF CHOCOLATE VISCOSITY

    JOURNAL OF TEXTURE STUDIES, Issue 5 2000
    J.-M. AESCHLIMANN
    The working group of the International Office of Cocoa, Chocolate and Sugar Confectionery (IOCCC) performed a sequence of five ring tests to improve the agreement of the standard method for measuring viscosity of chocolate between laboratories. Reporting shear stress measurements instead of using the Casson equation improved the agreement, as did standardising the method of cleaning the concentric cylinder and calibrating the viscometers. In the revised method, the standard deviation for shear stress measurement at shear rates greater than 5 s,1 from 23 laboratories was less than 8%. However, the Casson yield values had a seven-fold range and the Casson plastic viscosity a two-fold range, which was unacceptably high. A new method (IOCCC 2000) has been published as a result of this work and is available from CAOBISCO in Bruxelles, Belgium. [source]


    ISSUES AFFECTING AUSTRALIA'S RURAL OCCUPATIONAL THERAPY WORKFORCE

    AUSTRALIAN JOURNAL OF RURAL HEALTH, Issue 2 2000
    Jeannine Millsteed
    ABSTRACT The unequal distribution of health workers across Australia in favour of urban areas affects the provision of effective health services to rural and remote communities. Additional pressures on the current and future supply of occupational therapists may arise from a restructuring of the health labour force and demographic changes in the age structure of the population. Projections made on the basis of these data indicate that employment growth for occupational therapists will create a demand for 9600 therapists in 2005, or 79.9% more than the number of occupational therapists employed in 1994. Factors such as reductions in the level of immigration and the number of people of working age, and a diminishing population of school leavers to fill student places in universities will make it difficult to meet the projected demand for occupational therapists. Occupational therapy labour force planning suffers from a lack of detailed data on under-serviced areas. Such data are critical for clarifying the magnitude of the projected discrepancy between future demand and supply needs for occupational therapists in rural and urban areas in Australia. [source]


    Study of Factors Affecting the Performance of Voltammetric Copper Sensors Based on Gly-Gly-His Modified Glassy Carbon and Gold Electrodes

    ELECTROANALYSIS, Issue 12 2006
    Guozhen Liu
    Abstract This paper reports a study of the factors affecting the analytical performance of gold and glassy carbon electrodes modified with the tripeptide Gly-Gly-His for the detection of copper ions. Gly-Gly-His is attached to a glassy carbon (GC) surface modified with 4-carboxyphenyl moieties or a gold surface modified with 3-mercaptopropionic acid by the reaction of the N-terminal amine group of the peptide with the carboxylic acid groups of the monolayer via carbodiimide activation. X-ray photoelectron spectroscopy was used to characterize the steps in the biosensor fabrication. It was found that the analytical performance of a sensor prepared with Gly-Gly-His on a GC electrode was similar to that on a gold electrode under the same conditions. The performance was greatly enhanced at higher temperature, no added salt during copper accumulation and longer accumulation time within a pH range of 7,9. Interference studies and investigations of stability of the Gly-Gly-His sensor are reported. Analysis of natural water samples show that the sensors measure only copper ions that can complex at the sensor surface. Strongly complexed copper in natural water is not measured. Despite greater stability of diazonium salt derived monolayers on carbon surfaces compared with alkanethiols self-assembled monolayers on gold, the stability of the sensors was essentially the same regardless of the modification procedure. [source]


    Mediational behaviours of preschoolers teaching their younger siblings

    INFANT AND CHILD DEVELOPMENT, Issue 3 2003
    Pnina S. Klein
    There is very little research on the process of teaching in sibling interaction. The current study was designed to explore teaching behaviours of preschoolers and their effects on their toddler siblings. Participants were 40 dyads of 5-yr-olds and their 3-yr-old siblings from a middle class urban community in Israel. The children were divided into four equal groups based on gender and age of the siblings in each dyad. The children were visited at home and invited to play with two puzzles and two Lego games. Their play interaction with their siblings was videotaped. The observations were analysed using the observing mediational interaction (OMI) scale, assessing the frequency and style of the following behaviours: Focussing, Affecting, Encouraging, Expanding, and Regulating Behaviour. The younger siblings' success in playing the games was evaluated using a 5-point scale. The frequency of teaching behaviours in sibling interaction was found to be related to the younger siblings' success on the games. Affecting and Encouraging were significantly related to the younger siblings' level of success on the games. The teaching behaviours of older siblings were characterized by relatively high frequencies of Regulation of Behavior and Encouraging, moderate frequencies of Affecting and low frequencies of Expanding. Boys were found to receive more teaching behaviours than girls. Older brothers and sisters showed higher frequencies of teaching behaviour in interactions with their younger brothers than with their younger sisters. Copyright © 2003 John Wiley & Sons, Ltd. [source]


    Factors Affecting the Hydroxycinnamate Decarboxylase/Vinylphenol Reductase Activity of Dekkera/Brettanomyces: Application for Dekkera/Brettanomyces Control in Red Wine Making

    JOURNAL OF FOOD SCIENCE, Issue 1 2009
    S. Benito
    ABSTRACT:, The growth of Dekkera/Brettanomyces yeasts during the ageing of red wines,which can seriously reduce the quality of the final product,is difficult to control. The present study examines the hydroxycinnamate decarboxylase/vinylphenol reductase activity of different strains of Dekkera bruxellensis and Dekkera anomala under a range of growth-limiting conditions with the aim of finding solutions to this problem. The yeasts were cultured in in-house growth media containing different quantities of growth inhibitors such as ethanol, SO2, ascorbic acid, benzoic acid and nicostatin, different sugar contents, and at different pHs and temperatures. The reduction of p -coumaric acid and the formation of 4-ethylphenol were periodically monitored by HPLC-PDA. The results of this study allow the optimization of differential media for detecting/culturing these yeasts, and suggest possible ways of controlling these organisms in wineries. [source]


    Chemical Modification of Pigskin Gelatin: Factors Affecting the Esterification of Gelatin with Fatty Acid

    JOURNAL OF FOOD SCIENCE, Issue 9 2001
    K.B. Djagny
    ABSTRACT: This study investigated the esterification of pigskin gelatin with fatty acid catalyzed by acid in aqueous medium. Factors affecting the esterification reaction B temperature, pH, water content, fatty acid concentration, fatty acid type and reaction time- were elucidated in the view of optimizing the reaction. Under the same experimental conditions, increase in fatty acid concentration permitted the determination of the maximum amount of fatty acid that could be esterified per unit weight of gelatin and demonstrated that not all the hydroxyl functional groups present in the gelatin could be blocked by the fatty acid chains. [source]


    Factors Affecting %CDT Status at Entry Into a Multisite Clinical Treatment Trial: Experience from the COMBINE Study

    ALCOHOLISM, Issue 11 2006
    Raymond F. Anton
    Background: Carbohydrate-deficient transferrin (CDT) occurs as a higher percentage of normal transferrin (%CDT) in heavy drinkers. %CDT is used as a marker of both alcohol use disorder severity and treatment outcome both clinically and in treatment trials. Nevertheless, little is known about the parameters that predict which patients are %CDT positives at treatment entry. These parameters might include level of drinking, days of abstinence before testing, and severity of alcohol dependence before evaluation. Methods: %CDT levels were collected before randomization from participants of the COMBINE Study, a large federally sponsored multisite clinical trial evaluating medications and behavioral therapies in alcohol-dependent outpatients. %CDT (assayed in a central laboratory) was available in 1,193 individuals for whom drinking history in the 30 days before testing and measures of alcoholism severity were documented. The effects of drinking history and alcohol severity were evaluated for prediction of a %CDT-positive test status. Results: Less percent days abstinent (PDA) and more drinks per drinking day (DDD) were predictive of higher rates of %CDT-positive patients (maximum 67%). Up to 14 days of continuous abstinence before testing did not appear to significantly affect %CDT status. Rates of %CDT positives remained reasonably steady up to about 40% PDA. Years of drinking at dependence levels had an unexpected negative impact on %CDT-positive rates while previous treatment had a small but positive impact of %CDT-positive rates. ADS and DrInC scores had no predictive value over and above recent drinking amounts on %CDT status. Conclusions: %CDT is more likely to be positive in those who have more days of drinking and to a lesser degree in those who drink more per drinking day. It can remain positive even in those alcoholic subjects who stop drinking many days before testing. Alcoholic subjects with more treatment experiences appear to have a marginally higher %CDT-positive rate. [source]


    Critical Factors Affecting the Wettability of ,-Alumina by Molten Aluminum

    JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2004
    Ping Shen
    The wetting behaviors of ,-Al2O3 single crystals with three different faces,R(0112), A(01120), and C(0001),and polycrystals (PC) by molten aluminum were studied over a wide temperature range using both a conventional and an improved sessile-drop method. The critical factors affecting the wettability, such as temperature, atmosphere, substrate surface roughness, and crystallographic orientation, and the influence from the experimental technique, were thoroughly investigated. The results show that the aluminum surface oxidation and the thickness of the oxide film have a pronounced effect on the wettability, especially at low temperatures. To eliminate this effect, the experimental temperature must be over a critical value. Vacuum favors lowering this value compared with atmosphere, and the improved sessile-drop method, particularly using an impingement-dropping mode (I-mode), helps to weaken this effect by mechanical disruption and removal of the oxide film. However, the dropping distance and the dropping force must be controlled to prevent an overspreading of the drop. The effects of the substrate surface roughness and temperature are not significant in the case of a clean aluminum surface and a fine-prepared alumina surface. On the other hand, the effect of the alumina surface crystallographic orientation is noticeable and the wettability is in the order of R > A > PC > C. The intrinsic contact angles of the Al/,-Al2O3 system in the temperature range of 1000°,1500°C were estimated to be 76°,85° for the R and A faces, 88°,100° for the C face, and 77°,90° for the polycrystal, depending on the temperature. [source]


    Factors Affecting the Job,to,joblessness Turnover and Gender

    LABOUR, Issue 4 2002
    I. Theodossiou
    This paper explores gender differences with respect to the factors affecting the job,to,joblessness turnover. It casts light on the characteristics of those men and women who experience the highest propensity of their job ending in joblessness, taking into account the reasons for the job loss. The findings highlight the determinants of gender differences in labour turnover patterns. [source]


    Factors Affecting How Second Language Spanish Students Derive Meaning from Context

    MODERN LANGUAGE JOURNAL, Issue 2 2003
    Diana Frantzen
    Although first language (L1) and second language (L2) research has indicated that the meanings of unknown words can be derived from the contexts in which they occur, research has also found limitations to the value of context. Using data gathered in a classroom experiment on L2 vocabulary acquisition (Frantzen, 1998), the present study sought to determine some of the reasons why the context in which a word appears does not always lead a language learner to an accurate interpretation of its meaning. It expands the existing research by using a natural, intact, unmanipulated text as the context (an aspect underrepresented in current L2 word inferencing literature). Analysis of the students' answers, their self,reported guessing strategies, the contexts in which the words appeared, and the text's glossing revealed that the "blame" for the incorrect answers may be placed on: (a) the context itself, (b) the students' behavior, and in a minor way (c) the story's glossing. Numerous patterns are presented and discussed in light of other L1 and L2 research and new patterns are reported. [source]


    Myofascial Pain Syndrome Affecting the Quadratus Femoris

    PAIN PRACTICE, Issue 3 2010
    Joan Dalmau-Carolŕ MD
    Abstract The quadratus femoris is an external rotator of the hip. Quadratus femoris injury can accompany damage to the surrounding muscles. Guided by the clinical symptoms, the injection technique described here can facilitate accurate diagnosis in selected cases. [source]


    Variables Affecting the Participation in Individual Development

    PERFORMANCE IMPROVEMENT QUARTERLY, Issue 4 2001
    Janet L. Polach
    ABSTRACT Workers across the country are being asked to acquire more information at an increasing rate in response to technological, structural, and new product and process changes occurring in the workplace. Organizations continue to struggle with understanding the capabilities and capacity of their workforce and are making critical investments in building expertise. But how do organizations engage people in this development effort? This paper proposes three critical variables that affect an individual's participation in the development process. Proposed variables are: 1) individual expertise, 2) system stability, and 3) the acceptance for the need for improvement. The paper reviews the theories that support the proposed variables in terms of influencing learning participation, and it concludes by pointing out implications for human development practitioners. It identifies where further research is needed in gaining greater insight into understanding this complex issue. [source]


    Factors Affecting the Quality of Cryopreserved Buffalo (Bubalus bubalis) Bull Spermatozoa

    REPRODUCTION IN DOMESTIC ANIMALS, Issue 3 2009
    SMH Andrabi
    Contents Storage of buffalo (Bubalus bubalis) bull semen in the cryopreserved state is discussed in this article. Fertility rate in buffalo following artificial insemination with frozen,thawed semen is reviewed. To better understand the freezability of bubaline spermatozoa, the available data on biochemical components and the activity of specific enzymes of semen/spermatozoa are given. Moreover, the major factors that may influence the post-thaw viability and fertility of buffalo spermatozoa are examined in detail. In addition, suggestions for improvement in cryogenic procedures for buffalo spermatozoa are also given. [source]


    Targeted Tailored Management of the Breast Cancer Patient at Risk for Harboring a Germline Mutation,Current Trends Affecting the Selection of Patients Considering Surgical Prophylaxis for Breast Cancer

    THE BREAST JOURNAL, Issue 2009
    Edibaldo Silva MD
    Abstract:, Recent reports have documented the increasing use of mastectomy in women with breast cancer otherwise amenable to breast conservation. Similarly, other reports document an increase in the number of women undergoing contra-lateral prophylactic mastectomy for a single unilateral breast cancer. These trends are abetted by increasing use of MRI, inadequate risk counseling, and patient fear. Adequate and reliable risk assessment and genetic counseling are indispensable for the appropriate and personalized treatment of these individuals. In all of these instances, such counseling should be instituted well before the patients are submitted to any surgical intervention. An algorithm is presented which permits the orderly selection of patients who may benefit from such aggressive surgical intervention. [source]


    ORIGINAL ARTICLE: Tumor Necrosis Factor-,-Associated Mechanisms Affecting the Embryonic Response to Cyclophosphamide

    AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 3 2009
    Keren Mammon
    Problem, We have previously shown that TNF-,,/, embryos are more sensitive to the exposure to cyclophosphamide (CP) compared with TNF-,+/+ embryos; however, the underlying mechanisms are not fully understood. Thus, in our present study, we tried to identify those molecules that might be responsible for the protective effect of the cytokine. Method of study, CP-treated TNF-,,/, and TNF-,+/+ embryos were analyzed for changes in apoptosis by TUNEL and flow cytometry, while cell proliferation was analyzed by BrdU incorporation. The expression of Bax, bcl-2, p53, the p65 subunit of NF-,B and I,B, was assessed by Western blotting and immunohistochemistry. Results, CP-treated TNF-,,/, embryos exhibited a more profound decrease in their weight, which was accompanied by an earlier appearance of cellular damage and apoptotic cells and an earlier decrease in cell proliferation in the embryonic brain compared with TNF-,+/+ embryos. Also, an increased percentage of Bax-positive cells and a decreased percentage of bcl-2-positive cells were detected in TNF-,,/, embryos 48 hr after exposure, which were accompanied by a decreased percentage of p53-positive cells. Conclusion, Our data implicate TNF-, to be involved in the protection of the embryo against CP teratogenicity, possibly via alteration in Bax, bcl-2 or p53 expression. [source]


    A Maximum Likelihood-Based Method for Mining Major Genes Affecting a Quantitative Character

    BIOMETRICS, Issue 3 2001
    Rongling Wu
    Summary. In this article, we present a maximum likelihood-based analytical approach for detecting a major gene of large effect on a quantitative trait in a progeny population derived from a mating design. Our analysis is based on a mixed genetic model specifying both major gene and background polygenic inheritance. The likelihood of the data is formulated by combining the information about population behaviors of the major gene during hybridization and its phenotypic distribution densities. The EM algorithm is implemented to obtain maximum likelihood estimates for population and quantitative genetic parameters of the major locus. This approach is applied to detect an overdominant gene governing stem volume growth in a factorial mating design of aspen trees. It is suggested that further molecular genetic research toward mapping single genes affecting aspen growth and production based on the same experimental data has a high probability of success. [source]


    Retrovirus-Polymer Complexes: Study of the Factors Affecting the Dose Response of Transduction

    BIOTECHNOLOGY PROGRESS, Issue 2 2007
    Natalia Landázuri
    We have previously shown that complexes of Polybrene (PB), chondroitin sulfate C (CSC), and retrovirus transduce cells more efficiently than uncomplexed virus because the complexes are large and sediment, reaching the cells more rapidly than by diffusion. Transduction reaches a peak at equal weight concentrations of CSC and PB and declines when the dose of PB is higher or lower than CSC. We hypothesized that the nonlinear dose response of transduction was a complex function of the molecular characteristics of the polymers, cell viability, and the number of viruses incorporated into the complexes. To test this hypothesis, we formed complexes using an amphotropic retrovirus and several pairs of oppositely charged polymers and used them to transduce murine fibroblasts. We examined the effect of the type and concentration of polymers used on cell viability, the size and charge of the complexes, the number of viruses incorporated into the complexes, and virus binding and transduction. Transduction was enhanced (2.5- to 5.5-fold) regardless of which polymers were used and was maximized when the number of positive charge groups was in slight excess (15,28%) of the number of negative charge groups. Higher doses of cationic polymer were cytotoxic, whereas complexes formed with lower doses were smaller, contained fewer viruses, and sedimented more slowly. These results show that the dose response of transduction by virus-polymer complexes is nonlinear because excess cationic polymer is cytotoxic, whereas excess anionic polymer reduces the number of active viruses that are delivered to the cells. [source]


    Factors Affecting the Distribution and Abundance of Asplenium nidus L. in a Tropical Lowland Rain Forest in Peninsular Malaysia

    BIOTROPICA, Issue 4 2010
    Liwen Zhang
    ABSTRACT Asplenium nidus is an abundant epiphytic fern of tropical rain forests in the Old World, where it plays an important ecological role in the forest canopy as host to diverse arthropod communities. We investigated the factors that determine the distribution and abundance of A. nidus in the canopy of an aseasonal lowland dipterocarp forest at Pasoh Forest Reserve, Malaysia. We found that A. nidus was more abundant in the understory, and on hosts with smooth bark and relatively flat branch angles. Ferns were found on a wide diversity and size range of host taxa. However, both host taxa and host diameter at breast height had a significant effect on A. nidus occupancy. Asplenium nidus had an aggregated spatial distribution at all scales within the study area. Spatial aggregation at larger scales appears to be driven by habitat preference, as A. nidus abundance was positively associated with swampy areas and negatively associated with hilly areas. At smaller scales, limited dispersal of their wind-dispersed spores most likely explains the aggregated distribution. Larger individuals occurred higher in the canopy and were more common in the hilly area. Thus, the distribution of A. nidus may represent a trade-off between the availability of suitable microsites for establishment in the understory and better growth conditions higher in the canopy. However, A. nidus is known to comprise a complex of cryptic species, and future studies should incorporate molecular techniques to elucidate the potential role of speciation in explaining these patterns. Abstract in Malaysian is available at http://www.blackwell-synergy.com/loi/btp [source]


    Factors Affecting the Small Mammal Community Inside and Outside Katavi National Park, Tanzania1

    BIOTROPICA, Issue 2 2002
    T. M. Caro
    ABSTRACT Small mammal trapping showed that a minimum of 12 species live in and around Katavi National Park in western Tanzania. Species richness and abundance were greater outside the park than inside, extending results of an earlier study. Species richness and abundance were not significantly associated with vegetation cover or plant biomass but were negatively correlated with seed diversity, seed biomass, and possibly small carnivore abundance. Unfortunately, small mammal diets are unknown in this ecosystem and it can be argued that carnivores are unlikely to reduce species diversity, casting doubt on the importance of these variables. While the factors causing small mammals to fare poorly in this protected area are not yet understood, reduced food availability remains the best candidate. [source]


    Union Mobilization: A Consideration of the Factors Affecting the Willingness of Union Members to Take Industrial Action

    BRITISH JOURNAL OF INDUSTRIAL RELATIONS, Issue 2 2008
    Donna M. Buttigieg
    Drawing on mobilization theory, this article seeks to identify the factors that shape the willingness of union members to take industrial action. The study utilized data from a large-scale survey (N = 1,111) carried out in a financial services union during the renegotiation of a collective bargaining contract. The results suggested that individuals were more willing to engage in industrial action when they experienced a sense of injustice or unfairness in the employment relationship and when they held a collectivist orientation to work. Moreover, their propensity to take industrial action was greater when they considered that their union was an effective instrument of power. Workplace representatives were also important, particularly when they were seen as being responsive to their members' needs in situations of perceived injustice. The implications for mobilization theory and for union strategy are discussed. [source]


    ChemInform Abstract: Zirconium-Catalyzed Methylalumination of Heterosubstituted Arylethynes: Factors Affecting the Regio-, Stereo-, and Chemoselectivities.

    CHEMINFORM, Issue 6 2008
    Guangwei Wang
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]


    Etiology of strokes in children with sickle cell anemia

    DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 3 2006
    Michael R. DeBaun
    Abstract The most devastating complication of sickle cell anemia is cerebral infarction, affecting ,30% of all individuals with sickle cell anemia. Despite being one of the most common causes of stroke in infants and children, the mechanism of cerebral infarction in this population has not been extensively studied and is poorly understood. Multiple, synergistic factors are important in the pathogenesis of stroke including the hemodynamic effects of cerebral arterial occlusive disease, viscosity, chronic and acute anemia and acute medical events. This review focuses on the relationship between these factors in order to provide a foundation for further study of the etiology of strokes in this high-risk population. MRDD Research Reviews 2006;12:192,199. © 2006 Wiley-Liss, Inc. [source]


    Bilirubin as a determinant for altered neurogenesis, neuritogenesis, and synaptogenesis

    DEVELOPMENTAL NEUROBIOLOGY, Issue 9 2009
    Adelaide Fernandes
    Abstract Elevated levels of serum unconjugated bilirubin (UCB) in the first weeks of life may lead to long-term neurologic impairment. We previously reported that an early exposure of developing neurons to UCB, in conditions mimicking moderate to severe neonatal jaundice, leads to neuritic atrophy and cell death. Here, we have further analyzed the effect of UCB on nerve cell differentiation and neuronal development, addressing how UCB may affect the viability of undifferentiated neural precursor cells and their fate decisions, as well as the development of hippocampal neurons in terms of dendritic and axonal elongation and branching, the axonal growth cone morphology, and the establishment of dendritic spines and synapses. Our results indicate that UCB reduces the viability of proliferating neural precursors, decreases neurogenesis without affecting astrogliogenesis, and increases cellular dysfunction in differentiating cells. In addition, an early exposure of neurons to UCB decreases the number of dendritic and axonal branches at 3 and 9 days in vitro (DIV), and a higher number of neurons showed a smaller growth cone area. UCB-treated neurons also reveal a decreased density of dendritic spines and synapses at 21 DIV. Such deleterious role of UCB in neuronal differentiation, development, and plasticity may compromise the performance of the brain in later life. © 2009 Wiley Periodicals, Inc. Develop Neurobiol 2009 [source]


    Early Socio-political and Environmental Consequences of the Prestige Oil Spill in Galicia

    DISASTERS, Issue 3 2003
    J.D. García Pérez
    The controversial form in which the oil industry is run has once more caused a huge disaster , this one affecting the Galician coastal environment and economy. Oil-spill clean-up operations have been managed in Europe with some success but with considerable economic, environmental and social costs. The oil industry often avoids fully or even partially compensating those affected. The lack of both political will and political power has let the culprit (the oil industry) off the hook. This paper considers the spill of the Prestige to assess whether the balance of power between affected people and the oil industry can be changed. The paper examines the growing awareness of environmental issues among ordinary people in Spain, through the massive involvement of volunteers concerned with the damage done to the environment and to the livelihoods of fishing communities in Galicia. To understand these growing public concerns and the strength of opinion, the paper examines the details of the decisions taken by the central Spanish and local governments and the way these have informed the clean-up operations, the character of the oil companies involved and the feeling of impotence in the face of such disasters. The conclusion here is that the operations of the oil industry should be tightly regulated through EU legislation, and that this can come about as a result of organised political pressure from those affected by the oil spill, from the mass of volunteers, as well as from public opinion at large. [source]


    Macroecology of a host-parasite relationship

    ECOGRAPHY, Issue 1 2000
    Caryn C. Vaughn
    The larvae of freshwater mussels are obligate ectoparasites on fishes while adults are sedentary and benthic. Dispersal of mussels is dependent on the movement of fish hosts, a regional process, but growth and reproduction should be governed by local processes. Thus, mussel assemblage attributes should be predictable from the regional distribution and abundance of fishes. At a broad spatial scale in the Red River drainage, USA, mussel species richness and fish species richness were positively associated; maximum mussel richness was limited by fish richness, but was variable beneath that constraint. Measured environmental variables and the associated local fish assemblages each significantly accounted for the regional variation in mussel assemblages. Furthermore, mussel assemblages showed strong spatial autocorrelation. Variation partitioning revealed that pure fish effects accounted for 15.4% of the variation in mussel assemblages; pure spatial and environmental effects accounted for 16.1% and 7.8%, respectively. Shared variation among fish, space and environmental variables totaled 40%. Of this shared variation, 36.8% was associated with the fish matrix. Thus, the variation in mussel assemblages that was associated with the distribution and abundance of fishes was substantial (> 50%), indicating that fish community structure is an important determinant of mussel community structure. Although animals commonly disperse plants and, thus, influence the structure of plant communities, our results show a strong macroecological association between two disparate animal groups with one strongly affecting the assemblage structure of the other. [source]


    Regulation of ,FosB transcriptional activity by Ser27 phosphorylation

    EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2007
    Paula G. Ulery
    Abstract The transcription factor, ,FosB, is an important mediator of the long-term plasticity induced in brain by chronic exposure to drugs of abuse, stress, or several other psychoactive stimuli. We have previously demonstrated that the casein kinase 2 (CK2)-mediated phosphorylation of a highly conserved N-terminal serine (Ser27) plays a critical role in regulating ,FosB's unusual stability, while it does not affect that of the full-length FosB protein. In the present study, we analysed whether CK2 and Ser27 phosphorylation also play a role in regulating ,FosB's transcriptional activity. Our findings indicate that CK2 activation increases ,FosB's transactivation potential, while CK2 inhibition decreases it. Further, we show that preventing Ser27 phosphorylation by mutating the site to Ala results in a significant decrease in ,FosB transactivation, without affecting ,FosB's subcellular localization or DNA-binding affinity. In contrast, Ser27 does not seem to play a role in the transactivation potential of full-length FosB. These findings constitute the first evidence of a role for phosphorylation in ,FosB's transcriptional activity. [source]


    The Effect of Progesterone on Coronary Blood Flow in Anaesthetized Pigs

    EXPERIMENTAL PHYSIOLOGY, Issue 1 2001
    C. Molinari
    The present study was designed to investigate the effect of progesterone on the coronary circulation and to determine the mechanisms involved. In pigs anaesthetized with sodium pentobarbitone, changes in left circumflex or anterior descending coronary blood flow caused by intravenous infusion of progesterone at constant heart rate and arterial blood pressure were assessed using an electromagnetic flowmeter. In 14 pigs, infusion of 1 mg h,1 of progesterone caused an increase in coronary blood flow without affecting left ventricular dP/dtmax (rate of change of left ventricular systolic pressure) and filling pressures of the heart. In a further four pigs, this vasodilatory coronary effect was enhanced by graded increases in the dose of the hormone of between 1, 2 and 3 mg h,1. The mechanisms of the above response were studied in the 14 pigs by repeating the experiment after haemodynamic variables had returned to the control values observed before infusion. In six pigs, blockade of muscarinic cholinoceptors and adrenoceptors with atropine, propranolol and phentolamine did not affect the coronary vasodilatation caused by progesterone. In the remaining eight pigs, this response was abolished by intracoronary injection of N, -nitro-L-arginine methyl ester (L-NAME) even when performed after reversing the increase in arterial blood pressure and coronary vascular resistance caused by L-NAME with continuous intravenous infusion of papaverine. The present study showed that intravenous infusion of progesterone primarily caused coronary vasodilatation. The mechanism of this response was shown to involve the endothelial release of nitric oxide. [source]


    Site-directed mutagenesis and footprinting analysis of the interaction of the sunflower KNOX protein HAKN1 with DNA

    FEBS JOURNAL, Issue 1 2005
    Mariana F. Tioni
    The interaction of the homeodomain of the sunflower KNOX protein HAKN1 with DNA was studied by site-directed mutagenesis, hydroxyl radical footprinting and missing nucleoside experiments. Binding of HAKN1 to different oligonucleotides indicated that HAKN1 prefers the sequence TGACA (TGTCA), with changes within the GAC core more profoundly affecting the interaction. Footprinting and missing nucleoside experiments using hydroxyl radical cleavage of DNA showed that HAKN1 interacts with a 6-bp region of the strand carrying the GAC core, covering the core and nucleotides towards the 3, end. On the other strand, protection was observed along an 8-bp region, comprising two additional nucleotides complementary to those preceding the core. Changes in the residue present at position 50 produced proteins with different specificities. An I50S mutant showed a preference for TGACT, while the presence of lysine shifted the preference to TGACC, suggesting that residue 50 interacts with nucleotide(s) 3, to GAC. Mutation of Lys54,Val produced a protein with reduced affinity and relaxed specificity, able to recognize the sequence TGAAA, while the conservative change of Arg55,Lys completely abolished binding to DNA. Based on these results, we propose a model for the interaction of HAKN1 with DNA in which helix III of the homeodomain accommodates along the major groove with Arg55, Asn51, Lys54 and Ile50, establishing specific contacts with bases of the GACA sequence or their complements. This model can be extended to other KNOX proteins given the conservation of these amino acids in all members of the family. [source]


    Contribution of endothelium-derived hyperpolarizing factors to the regulation of vascular tone in humans

    FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 4 2008
    Jeremy Bellien
    Abstract Endothelium plays a crucial role in the regulation of cardiovascular homeostasis through the release of vasoactive factors. Besides nitric oxide (NO) and prostacyclin, increasing evidences show that endothelium-derived hyperpolarizing factors (EDHF) participate in the control of vasomotor tone through the activation of calcium-activated potassium channels. In humans, the role of EDHF has been demonstrated in various vascular beds including coronary, peripheral, skin and venous vessels. The mechanisms of EDHF-type relaxations identified in humans involved the release by the endothelium of hydrogen peroxide, epoxyeicosatrienoic acids (EETs), potassium ions and electronical communication through the gap junctions. The role of EETs could be particularly important because, in addition contributing to the maintenance of the basal tone and endothelium-dependent dilation of conduit arteries, these factors share many vascular protective properties of NO. The alteration of which might be involved in the physiopathology of cardiovascular diseases. The evolution of EDHF availability in human pathology is currently under investigation with some results demonstrating an increase in EDHF release to compensate the loss of NO synthesis and to maintain the endothelial vasomotor function whereas others reported a parallel decrease in NO and EDHF-mediated relaxations. Thus, the modulation of EDHF activity emerges as a new pharmacological target and some existing therapies in particular those affecting the renin,angiotensin system have already been shown to improve endothelial function through hyperpolarizing mechanisms. In this context, the development of new specific pharmacological agents especially those increasing EETs availability may help to prevent endothelial dysfunction and therefore enhance cardiovascular protection in patients. [source]


    Managing in Higher Education: The ,Wicked Issues'

    HIGHER EDUCATION QUARTERLY, Issue 1 2000
    David Watson
    Using the concept of ,wicked' or ,slushy' issues in social policy, the author presents a taxonomy of such problems faced by managers in universities and colleges. Groups of problems include: those shared with all large and complex enterprises; those affecting the public services with special force; and those peculiar to higher education. He concludes with some reflections on management reactions to such problems. [source]