Toward a Unified Paradigm of Race

Racism in Mind. Michael Levine and Tamas Pataki, eds. Ithaca, NY: Cornell University Press, 2004. 320 pp.
Only Skin Deep: Changing Visions of the American Self. Coco Fusco and Brian Wallis, eds. New York: Harry N. Abrams, 2003. 416 pp.     

Carbon dioxide enrichment reduces shoot growth in sweet chestnut seedlings (Castanea sativa Mill.)*

Abstract. Two-year-old potted sweet chestnut seedlings were grown at 350 ppm CO₂ and 700 ppm, day and night in constantly ventilated tunnels during two full growing seasons, near Paris, France (48° N, 2° E). Enrichment with CO₂ caused an unusual shoot growth response. After the end of July, stem elongation ceased in 62% of the CO₂ enriched plants as compared with 37% in the control. The leaves of CO₂-enriched seedlings showed early senescence, indicated by premature yellowing and a decrease in chlorophyll content. This was associated with nutrient dilution brought about by the rapid growth of these trees. The increase in total dry weight of the CO₂-enriched seedlings was essentially the result of increase in the root dry weight (69%). Shoot weight decreased by 22% relative to the control. Total leaf area per enriched plant was 25% smaller than the control. This unusual pattern of growth and carbon allocation of the CO₂ treated Chestnut trees emphasizes the concept of a response specificity within trees to an increase of atmospheric CO₂.     

Effect of Light Intensity, Carbon Dioxide Concentration, and Leaf Temperature on Gas Exchange of Spray Carnation Plants

The rates of CO₂ assimilation by potted spray carnation plants(cv. Cerise Royalette) were determined over a wide range oflight intensities (45–450 W m^–2 PAR), CO₂ concentrations(200–3100 vpm), and leaf temperatures (5–35 °C).Assimilation rates varied with these factors in a way similarto the response of single leaves of other temperate crops, althoughthe absolute values were lower. The optimal temperature forCO₂ assimilation was between 5 and 10 °C at 45 W m^–2PAR but it increased progressively with increasing light intensityand CO₂ concentration up to 27 °C at 450 W m^–2 PARand 3100 vpm CO₂ as expressed by the equation TOpt = –6.47-h 2.336 In G + 0.031951 where C is CO₂ concentration in vpmand I is photo-synthetically active radiation in W m^–2.CO₂ enrichment also increased stomatal resistance, especiallyat high light intensities. The influence of these results on optimalization of temperaturesand CO₂ concentrations for carnation crops subjected to dailylight variation, and the discrepancy between optimal temperaturesfor growth and net photosynthesis, are discussed briefly     

Effect of Night Temperature on Photosynthesis, Transpiration, and Growth of Spray Carnations

Spray carnation plants were grown for several weeks under an8 h day/16 h night regime at temperatures of approximately 21°C by day and 6, 17, or 30 °C by night. Subsequently,the rates of photosynthesis and transpiration at 20 °C weresimilar. This contrasts with evidence published for some otherspecies. Night temperature had only a slight effect on the plant's growthrate. Leaf area ratios were also similar between treatmentsand for two intervals covering a 5 week period. At the highnight temperature flowers were initiated sooner and there werefewer side shoots per plant than at the lower temperatures. The implications of these results for the optimization of theclimatic environment are discussed briefly, and the resultsare compared with those reported for other species.     

Colormute: Race Talk Dilemmas in an American School

Colormute: Race Talk Dilemmas in an American School . Mica Pollock. Princeton, NJ: Princeton University Press, 2004. 268 pp.     

Relationships between protease activity, host blood and infection rates in Glossina morsitans sspp. infected with Trypanosoma congolense, T.brucei and T.simiae

Abstract. Midgut protease activity in Glossina morsitans centralis and G. m. morsitans , at 48h post bloodmeal averaged 1.8IU of trypsin-like activity. These two tsetse subspecies differ in their susceptibility to trypanosome infection. Except for low levels in flies fed on waterbuck blood (0.7IU), activity did not differ in flies fed a variety of host bloods (goat, pig, cow, buffalo, eland) and trypanosome species ( Trypanosoma congolense, T.brucei, T.simiae ). Protease activity was also not correlated with infection rates, despite large differences in infection rates among experiments. Nevertheless, addition of 0.06M D(+)-glucosamine to parasitaemic blood resulted in a three-fold reduction in protease activity, coincident with a large increase in infection rate. This effect did not occur when parasites or D(+)-glucosamine were added alone to the bloodmeal, suggesting that the effect was due to metabolism of D(+)-glucosamine by parasites.