Two hundred second chromosomes were extracted from a Japanese population in October of 1972, and the viabilities and productivities of homozygotes and heterozygotes from them were examined. Viability was measured by the Cgamma method and productivity by the number of progeny produced per female. The frequency of lethal-carrying chromosomes was 0.1315. When the average heterozygote viability was...

background: iron, manganese, and aluminum are three abundant metals on earth and their concentrations have increased in aquatic environments as a result of natural and industrial activities. this study was undertaken to report the median acute toxicity (lc50) and accumulation of the sub-lethal concentration (10% 96-h lc50) of iron (fe), manganese (mn) and aluminum (al) in kutum (rutilus kutum) ...

spirulina platensis, a cyanobacterium of economic important was studied for the tolerance to cadmium. the bioassay studies showed the ec50 value to be 1.53 mg/g. the cyanobacterium was very sensitive to low metal concentration and the productivity was also reduced. the chlorophyll pigments reduced with decreasing the algal biomass. the algal survival rate showed a marked reduction in their surv...

Introduction Temperature fluctuations are important for the distribution and survival of insects. Rapid hardening, a type phenotypic plasticity, is an adaptation that can help individuals better tolerate lethal temperatures because earlier exposure to sublethal but stressful temperature. Nutrition sex also known influence species ability thermal stress. This study determined effects larval diet...

Human rIL-1 alpha and human rIL-1 beta were examined for their ability to potentiate the lethal and hypothermic effects of mouse rTNF-alpha in mice. The LD50 of rTNF-alpha was 1.5 micrograms/mouse, whereas the LD50 of rTNF-alpha was reduced to 0.4 micrograms/mouse and 0.5 micrograms/mouse when rTNF-alpha was administered in combination with a nonlethal dose of rIL-1 alpha or rIL-1 beta, respect...

Almtract--1. Lizards with different preferred temperatures were water-loaded, and their ability to excrete excess water and conserve electrolytes was tested at several temperatures. 2. Rates of water excretion were much less temperature dependent in lizards having a low preferred temperature, but were maximal at about 30-35°C in both species. 3. Urinary sodium levels were minimal at temperature...

Out of 25,000 EMS-treated third chromosomes examined, ten dominant temperature-sensitive (DTS) lethal mutations which are lethal when heterozygous at 29 degrees C but survive at 22 degrees C were recovered. Seven of the eight mutations mapped were tested for complementation; these mutants probably define eight loci. Only DTS-2 survived in homozygous condition at 22 degrees C; homozygous DTS-2 f...

Vegetation change is expected with global climate change, potentially altering ecosystem function and climate feedbacks. However, causes of plant mortality, which are central to vegetation change, are understudied, and physiological mechanisms remain unclear, particularly the roles of carbon metabolism and xylem function. We report analysis of foliar nonstructural carbohydrates (NSCs) and assoc...