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ABSTRACTThe circadian clock regulates the expression of many genes involved in a wide range of biological functions through output pathways such as mitogen-activated protein kinase (MAPK) pathways. We demonstrate here that the clock regulates the phosphorylation, and thus activation, of the MAPKs MAK-1 and MAK-2 in the filamentous fungus Neurospora crassa. In this study, we identified genetic targets of the MAK-1 pathway, which is homologous to the cell wall integrity pathway in Saccharomyces cerevisiaeand the extracellular signal-regulated kinase 1/2 (ERK1/2) pathway in mammals. When MAK-1 was deleted from Neurosporacells, vegetative growth was reduced and the transcript levels for over 500 genes were affected, with significant enrichment for genes involved in protein synthesis, biogenesis of cellular components, metabolism, energy production, and transcription. Additionally, of the ~500 genes affected by the disruption of MAK-1, more than 25% were previously identified as putative clock-controlled genes. We show that MAK-1 is necessary for robust rhythms of two morning-specific genes, i.e., ccg-1and the mitochondrial phosphate carrier protein gene NCU07465. Additionally, we show clock regulation of a predicted chitin synthase gene, NCU04352, whose rhythmic accumulation is also dependent upon MAK-1. Together, these data establish a role for the MAK-1 pathway as an output pathway of the circadian clock and suggest a link between rhythmic MAK-1 activity and circadian control of cellular growth.

Students’ perceptions of school safety and experiences with bullying were examined in a large Canadian cohort of 5,493 girls and 5,659 boys in Grades 4 to 12. Results indicate notable differences in when and where students felt safe based on their own perceptions of safety and their own experiences with bullying, particularly across elementary and secondary schools. For elementary students, especially those involved in bullying, the playground/school yard and outside recess/break time were particularly hazardous, whereas for secondary students involved in bullying, the hallways, school lunchroom/cafeteria, and outside recess/break were considered especially dangerous. The commonality across student-identified unsafe areas is that they tend to not be well supervised by school personnel. Accordingly, the present results underscore the need to increase adult supervision in areas in which an overwhelming majority of students report feeling unsafe.

Circadian clocks and mitogen-activated protein kinase (MAPK) signaling pathways are fundamental features of eukaryotic cells. Both pathways provide mechanisms for cells to respond to environmental stimuli, and links between them are known. We recently reported that the circadian clock in Neurospora crassa regulates daily rhythms in accumulation of phosphorylated, and thus active, OS-2 MAPK, a relative of mammalian p38 MAPK, when cells are grown in constant conditions. In the absence of acute stress, rhythmically activated MAPK then signals to downstream effector molecules to regulate rhythmic expression of target genes of the pathway. Clock regulation of MAPK signaling pathways provides a mechanism to coordinately control major groups of genes such that they peak at the appropriate times of day to provide a growth and survival advantage to the organism by anticipating stresses. MAPK pathways are well known for their role in cell proliferation and tumor suppression. New evidence reveals that some mammalian clock components also function as tumor suppressors and rhythms in phospho-MAPK have been observed in higher eukaryotes. Thus, the role of the clock in regulation of the activity of MAPK pathways provides important clues into the function of the circadian clock as a tumor suppressor.

Transgenic Indian mustard [Brassica juncea(L.) Czern.] plants overproducing the enzymes γ‐glutamylcysteine synthetase (ECS) or glutathione synthetase (GS) were shown previously to have increased levels of the metal‐binding thiol peptides phytochelatins and glutathione, and enhanced Cd tolerance and accumulation. Furthermore, transgenic Indian mustard plants overexpressing adenosine triphosphate sulfurylase (APS) were shown to have higher levels of glutathione and total thiols. These results were obtained with a solution culture. To better examine the phytoremediation potential of these transgenics, a greenhouse experiment was performed in which the transgenics were grown on metal‐contaminated soil collected from a USEPA Superfund site near Leadville, Colorado. A grass mixture used for revegetation of the site was included for comparison. The ECS and GS transgenics accumulated significantly (P< 0.05) more metal in their shoot than wild‐type (WT) Indian mustard, while the APS plants did not. Of the six metals tested, the ECS and GS transgenics accumulated 1.5‐fold more Cd, and 1.5‐ to 2‐fold more Zn, compared with wild‐type Indian mustard. Furthermore, the ECS transgenics accumulated 2.4‐ to 3‐fold more Cr, Cu, and Pb, relative to WT. The grass mixture accumulated significantly less metal than Indian mustard: approximately 2‐fold less Cd, Cu, Mn, and Zn, and 5.7‐fold less Pb than WT Indian mustard. All transgenics removed significantly more metal from the soil compared with WT Indian mustard or an unplanted control. While WT did not remove more metal than the unplanted control for any of the metals tested, all three types of transgenics significantly reduced the soil metal concentration, and removed between 6% (Zn) and 25% (Cd) of the soil metal. This study is the first to demonstrate enhanced phytoextraction potential of transgenic plants using polluted environmental soil. The results confirm the importance of metal‐binding peptides for plant metal accumulation and show that results from hydroponic systems have value as an indicator for phytoremediation potential.

Several letters to the editor related to motorcycling are presented including, one on the motorcycle industry of Australia, one on motorcycle racing driver Valentine Rossi, and one on the use of speed and redlight cameras in Australia.

Several letters to the editor are presented in about motorcycle riders who were given the chance to ride minimotos, Honda Motor Co. Ltd.'s 50-year anniversary celebration, and a rider who has been riding Japanese sports bikes.