Being affected by the other

Against present trends towards the homogenization and the hegemony of one world intellectual koine, the author underscores the richness contained in the plurality of intellectual styles, discursive paradigms and cultural configurations. He shows that all encounters encompass a tragic dimension, that of power and dependence, that cannot be neutralized by the most sensitive individual empathy. Seven rules are finally offered for guiding Western and non-Western scholars on the road towards the transnational and transcultural dialogue.

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Sommaire La richesse que représente le pluralisme des styles intellectuels et la multiplicité des configurations discursives et culturelles est mise en paralléle avec l'appauvrissement qu'engendre le processus d'homogénéisation et d'hégémonie croissante d'une koine intellectuelle à prétention universelle. L'auteur souligne la dimension tragique qui s'inscrit dans toute rencontre, une dimension de pouvoir et de dépendence qui ne peut être annulée par les meilleures qualités individuelles d'empathie. Pour guider les scientifiques tant occidentaux que non-occidentaux sur la voie du dialogue transculturel et transnational, l'auteur présente brièvement sept règles.

     

Identifying pathways affected by cancer mutations

Mutations in 15 cancers, sourced from the COSMIC Whole Genomes database, and 297 human pathways, arranged into pathway groups based on the processes they orchestrate, and sourced from the KEGG pathway database, have together been used to identify pathways affected by cancer mutations. Genes studied in ≥ 15, and mutated in ≥ 10 samples of a cancer have been considered recurrently mutated, and pathways with recurrently mutated genes have been considered affected in the cancer. Novel doughnut plots have been presented which enable visualization of the extent to which pathways and genes, in each pathway group, are targeted, in each cancer. The ‘organismal systems’ pathway group (including organism-level pathways; e.g., nervous system) is the most targeted, more than even the well-recognized signal transduction, cell-cycle and apoptosis, and DNA repair pathway groups. The important, yet poorly-recognized, role played by the group merits attention. Pathways affected in ≥ 7 cancers yielded insights into processes affected.     

Developmental changes affected by Mn deficiency

The changes in tissue Mn, Cu, Fe, Zn, and Superoxide dismutase (SOD) activity were studied in control and Mn-deficient mice during postnatal development. Mn levels were lower in tissues from Mn-deficient mice than in controls throughout development. By day 60, Mn concentration in tissues from Mn-deficient mice was at least 70% lower than that of controls. Cu levels in the two groups did not differ appreciably. Liver Cu concentration was highest at day 5, then decreased. Heart and kidney Cu increased throughout development. Fe concentration in heart and liver was similar in both groups at 1, 5, and 20 days of age, but at day 60, kidney Fe in the Mn-deficient mice was 40% higher than in controls. The developmental pattern for MnSOD activity paralleled that of Mn concentration. At day 5, there were no differences in MnSOD activity between control and deficient mice. By day 60, MnSOD activity in most tissues was at least 50% lower than that of controls, possibly increasing the susceptibility of the Mn deficient animal to oxidative damage. These developmental patterns should help investigators to determine the tissues and time periods in which to study trace element metabolism.     

Proteasome structures affected by ionizing radiation

Exposure of cells to ionizing radiation slows the rate of degradation of substrates through the proteasome. Because the 26S proteasome degrades most short-lived cellular proteins, changes in its activity might significantly, and selectively, alter the life span of many signaling proteins and play a role in promoting the biological consequences of radiation exposure, such as cell cycle arrest, DNA repair, and apoptosis. Experiments were therefore undertaken to identify the radiation target that is associated with the proteasome. Regardless of whether they were irradiated before or after extraction and purification from human prostate cancer PC3 cells, 26S proteasomes remained intact but showed a rapid 30% to 50% dose-independent decrease in their three major enzymatic activities following exposure to 1 to 20 Gy. There was no effect on 20S proteasomes, suggesting that the radiation-sensitive target is located in the 19S cap of the 26S proteasome, rather than in the enzymatically active core. Because the base of the 19S cap contains an ATPase ring that mediates substrate unfolding, pore opening, and translocation of substrates into the catalytic chamber, we examined whether the ATPase activity of purified 26S proteasomes was affected. In fact, in vitro irradiation of proteasomes enhanced their ATPase activity. Furthermore, pretreatment with low concentrations of the free radical scavenger tempol was able to prevent both the radiation-induced decrease in proteolytic activity and the increase in ATP utilization, indicating that free radicals are mediators of these radiation-induced phenomena. Finally, we have shown that cell irradiation results in the accumulation of proteasome substrates: polyubiquitinated proteins and ornithine decarboxylase, indicating that the observed decrease in proteasome function is physiologically relevant.     

Zinc uptake by corn as affected by vesicular-arbuscular mycorrhizae

Pot-grown mycorrhizal and non-mycorrhizal sweet corn were grown in a low Zn soil. All treatments received a complete nutrient solution with or without Zn. Treatments were harvested sequentially to detemine temporal mycorrhizal effects on: (a) tissue and water soluble Zn and (b) differential uptake of P and Zn. Plants grown with supplemental Zn had greater growth and Zn tissue concentration than those not receiving Zn. With no supplemental Zn, mycorrhizal treatments had greater growth and Zn concentration than non-mycorrhizal treatments. There was no indication of nutrient interaction between Zn and P. Over the range of tissue Zn found, there appeared to be no advantage to water soluble Zn analysis over total Zn in assessing plant Zn status.     

Water absorption by seeds as affected by soil temperature

Summary Water absorption by seeds of wheat and corn was studied over a temperature range of 5 to 35°C spaced at 5°C in sandy loam soil with moisture levels of 10 and 15 per cent. With increasing temperature, water absorption increased. The difference in water absorption due to moisture levels under study was not appreciable. Irrespective of treatments, a rapid initial absorption was followed by a tapering-off period of slow absorption.     

Nitrogen uptake of plants affected by windbreaks

Summary The present study was carried out with the windbreaks to determine the effect of wind protection on the uptake of nitrogen by plants. The results of the analysis clearly show that nitrogen uptake is favourably affected by the windbreaks. Nitrogen uptake by the plants in the protected zone at Altona was 52% higher as compared to the unprotected zone. The plants at both the optimal protected and less protected areas at Newton absorbed similar amounts of nitrogen. The increased uptake of nitrogen in the protected zone at Altona was due to the windbreak which favourably influenced the temperature and the evapotranspiration rate. This resulted in the better growth and yield of plants.

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Sommaire La présente étude fut faite à l'aide de brise-vents afin de determiner l'effect de protection du vent en rapport à l'ingestion de l'azote par les plantes. Les résultats de l'analyse montrent clairement que l'ingestion d'azote est favourablement affectée par les brise-vents. L'ingestion d'azote par les plantes de la zone protégée d'Altona fut 52% plus haute que celle de la zone non-protégée. Les plantes, aux endroits de protection maximale et de moindre protection de Newton, ont absorbé des quantités semblables d'azote. L'augmentation de l'ingestion en azote dans la zone protégée d'Altona fut due à l'effect des brisevents qui ont influen?é favourablement la température et le taux d'évapotranspiration. Ceci donna finalement une meilleure croissance et une meilleure productivité des plantes.

     

Weighting affected sib pairs by marker informativity

For the analysis of affected sib pairs (ASPs), a variety of test statistics is applied in genomewide scans with microsatellite markers. Even in multipoint analyses, these statistics might not fully exploit the power of a given sample, because they do not account for incomplete informativity of an ASP. For meta-analyses of linkage and association studies, it has been shown recently that weighting by informativity increases statistical power. With this idea in mind, the first aim of this article was to introduce a new class of tests for ASPs that are based on the mean test. To take into account how much informativity an ASP contributes, we weighted families inversely proportional to their marker informativity. The weighting scheme is obtained by use of the de Finetti representation of the distribution of identity-by-descent values. We derive the limiting distribution of the weighted mean test and demonstrate the validity of the proposed test. We show that it can be much more powerful than the classical mean test in the case of low marker informativity. In the second part of the article, we propose a Monte Carlo simulation approach for evaluating significance among ASPs. We demonstrate the validity of the simulation approach for both the classical and the weighted mean test. Finally, we illustrate the use of the weighted mean test by reanalyzing two published data sets. In both applications, the maximum LOD score of the weighted mean test is 0.6 higher than that of the classical mean test.     

Spray drift as affected by meteorological conditions

Spray drift can be defined as the quantity of plant protection product that is carried out of the sprayed (treated) area by the action of air currents during the application process. This continues to be a major problem in applying agricultural pesticides. The purpose of this research is to measure and compare the amount of drift for different climatological conditions under field conditions. Spray drift was determined by sampling in a defined downwind area at different positions in a flat meadow using horizontal drift collectors (sedimenting spray drift) and pipe cleaners (airborne spray drift) for a reference spraying. Meteorological conditions were monitored during each experiment. A drift prediction equation for the reference spraying was set up to predict the expected magnitude of sedimenting drift at various drift distances and atmospheric conditions (wind speed and temperature). This equation can be used to compare measurements using other spraying techniques under different weather conditions to the reference spraying. In 2005, more measurements will be performed to validate the statements and the model reflected in this paper.     

Tobacco polyamines as affected by stresses induced by different pathogens

A decrease of the polyamine content of tobacco leaves inoculated with fungal, bacterial and viral pathogens differing in symptom severity (mosaic, chlorosis, necrosis) was observed. The extent of the decrease was not related to the type of pathogens but to the severity of damage symptoms; hence, the polyamine decline may be regarded as a common response of tobacco to damage produced by pathogens. This revised version was published online in July 2006 with corrections to the Cover Date.     

Isoprene emission by plants is affected by transmissible wound signals

Isoprene (2-methyl 1,3-butadiene) is emitted from many plants, but the signals regulating isoprene emission are unknown. Mounting leaves in a gas exchange chamber or taking small leaf punches for biochemical analysis was found to reduce the rate of isoprene emission (Loreto & Sharkey 1993). This phenomenon was investigated by putting terminal leaflets of velvet bean (Mucuna deeringeniana L.) and kudzu [Pueraria lobaia (Willd) Ohwi.] into a gas exchange chamber and monitoring isoprene emission and photosynthesis. Lateral leaflets or remote leaves were then wounded or mechanically stimulated. The rate of isoprene emission was reduced after 1 min by up to 75% by burning a lateral leaflet with a match. Even a 7 ms^?1 (25km h^?1) wind imposed on a lateral leaflet reduced isoprene emission from the terminal leaflet by 18%. Photosynthesis rates were either unaffected by these treatments or reduced more slowly than isoprene emission rates, indicating that the effect of isoprene emission rates was not a consequence of changes in photosynthetic activity. Isoprene emission from a terminal leaflet was reduced by burning leaves above and below the monitored leaflet when on the same stem. The effect was much reduced if the burned leaf (all three leaflets) was on a different stem from the monitored leaflet. Reduction of the rate of isoprene emission was observed even when the burned leaf was 52 cm distant from the measured leaflet. Increasing the distance between the stressed leaf and the monitored leaf caused the effect to be slower and smaller. It is speculated that a signal is generated by wounding which propagates through the plant at 1.3 mm s^?1. This velocity was consistent throughout the measurements and is similar to the rate of propagation of electrical signals such as action potentials and variation potentials. The effect of the environmental stress, and particularly the wind effect, can be frequent in nature and should be considered when estimating local and regional emission of isoprene for modelling atmospheric chemistry. If leaf samples used for isoprene determination are exposed to the type of stress we investigated, isoprene emission inventories based on leaf level measurements will be underestimated.     

Mobilization of iron by phytosiderophores as affected by other micronutrients

It has been shown previously (Treeby et al., 1989) that phytosiderophores, released by roots of iron deficient grasses (Gramineae), mobilize from calcareous soils not only iron (Fe) but also zinc (Zn), manganese (Mn) and copper (Cu). Mobilization of Fe may therefore be impaired by other micronutrient cations. This has been studied in both, model experiments with Fe hydroxide and with a calcareous soil (15% CaCO₃, pH 8.6) amended with micronutrients as sulfate salts.Mobilization of Fe from Fe hydroxide by phytosiderophores (epi-3-hydroxymugineic acid) was not affected by the addition of CaCl₂, MgSO₄ and MnSO₄, slightly inhibited by ZnSO₄ and strongly inhibited by CuSO₄. In a calcareous soil amended with increasing levels of ZnSO₄, MnSO₄ and CuSO₄, mobilization of Fe by phytosiderophores remained uneffected by Zn and Mn amendments but was progressively impaired by increasing levels of Cu amendment, correlated with corresponding enhancement of Cu mobilization.High concentrations of ZnSO₄ and MnSO₄ and relatively high concentrations of CuSO₄ were required for inhibition of Fe mobilization by phytosiderophores. It is therefore concluded that in most calcareous soils phytosiderophores efficiently mobilize Fe, and that phytosiderophores play an important role in Fe acquisition by grasses grown on calcareous soils.