Dissolved concentrations of four forms of arsenic: arsenite, arsenate, monomethylarsenic, and dimethylarsenic, were measured in the Patuxent River Estuary near Benedict, Maryland, over two annual cycles. In each year, total arsenic concentrations peaked in the summer, in lateJuly and August, while minimum concentrations occurred in winter. Except in late winter, arsenate was a predominant form ...

dieback of trees is a serious problem in many different regions of the world and city authorities are concern about conserving and maintaining the green spaces in the big cites. this study was conducted to evaluate the early dieback and yellowing of sycamore trees (platanus sp.) by using a completely randomized block design (split split plot) in 15 replications (sites) in 2009. the main plot wa...

In northern Canada, lake chub (Cyprinidae: Couesius plumbeus) have colonized a variety of thermal springs that differ substantially from the ancestral environment in both mean temperature and thermal variation. To examine whether this environmental change is associated with differences in physiological traits, we compared the thermal breadth, capacity for acclimation of thermal tolerance, and m...

Several studies have demonstrated that localized heating of tree stems induces localized cambial reactivation. We analyzed by light microscopy the effects of early spring increases in ambient temperature in 2005 and 2007 on the timing of cambial reactivation and xylem differentiation in stems of two trees of a cloned deciduous hardwood hybrid poplar (Populus sieboldii Miquel. x P. grandidentata...

1 In the present study, we documented the lethal and sublethal effects of the entomopathogen Btk on spruce budworm and its progeny under various environmental conditions. We hypothesized that aerial spray of Bacillus thuringiensis ssp. kurstaki (Btk) could affect the biological performance of the surviving spruce budworm (Choristoneura fumiferana Clem.) populations and their progenies and that ...

Cold stress has always been a significant limitation for plant development and causes substantial decreases in crop yield. Some temperate plants, such as Arabidopsis, have the ability to carry out internal adjustment, which maintains checks metabolic machinery during cold temperatures. This acclimation process requires prior exposure low, chilling temperatures prevent damage subsequent freezing...

Cotton-rapeseed or cotton-wheat double cropping systems are popular in the Yangtze River Valley and Yellow River Valley of China. Due to the competition of temperature and light resources during the growing season of double cropping system, cotton is generally late-germinating and late-maturing and has to suffer from the coupling of declining temperature and low light especially in the late gro...

While the responses of photosynthesis to water stress have been widely studied, acclimation to sustained water stress and recovery after re-watering is poorly understood. In particular, the factors limiting photosynthesis under these conditions, and their possible interactions with other environmental conditions, are unknown. To assess these issues, changes of photosynthetic CO(2) assimilation ...

Three ribosomal protein genes induced by low-temperature treatment were isolated from soybean. GmRPS13 (742 bp) encodes a 17.1 kDa protein which has 95% identity with the 40S ribosomal protein S13 of Panax ginseng (AB043974). GmRPS6 (925 bp) encodes a 28.1 kDa protein which has 94% identity with the 40S ribosomal protein S6 of Asparagus officinalis (AJ277533). GmRPL37 (494 bp) encodes a 10.7 kD...