Conserved chromatin and repetitive patterns reveal slow genome evolution in frogs.

Frogs are an ecologically diverse and phylogenetically ancient group of anuran amphibians that include important vertebrate cell and developmental model systems, notably the genus Xenopus. Here we report a high-quality reference genome sequence for the western clawed frog, Xenopus tropicalis, along with draft chromosome-scale sequences of three distantly related emerging model frog species, Eleutherodactylus coqui, Engystomops pustulosus, and Hymenochirus boettgeri. Frog chromosomes have remained remarkably stable since the Mesozoic Era, with limited Robertsonian (i.

CRISPR-Cas9-mediated knockout of and in cassava attenuates toxic cyanogen production.

Cassava () is a starchy root crop that supports over a billion people in tropical and subtropical regions of the world. This staple, however, produces the neurotoxin cyanide and requires processing for safe consumption. Excessive consumption of insufficiently processed cassava, in combination with protein-poor diets, can have neurodegenerative impacts.

Deeply conserved synteny and the evolution of metazoan chromosomes.

Animal genomes show networks of deeply conserved gene linkages whose phylogenetic scope and chromosomal context remain unclear. Here, we report chromosome-scale conservation of synteny among bilaterians, cnidarians, and sponges and use comparative analysis to reconstruct ancestral chromosomes across major animal groups. Comparisons among diverse metazoans reveal the processes of chromosome evolution that produced contemporary karyotypes from their Precambrian progenitors.

Diagnostic validity of the passive-aggressive personality disorder: suggestions for reform.

Numerous problems have plagued the diagnosis of the passive-aggressive (P-A) personality disorder. Based on criteria established to evaluate the functional utility of diagnostic categories, the P-A personality disorder does not appear to be an adequate psychiatric diagnosis. However, the concept of passive-aggressiveness may be retained as a useful psychiatric construct when viewed from a dimensional rather than a categorical perspective.

Pediatric house staff's psychological response to call duty.

Psychological responses to the stress of call duty for first- and second-year pediatric house officers were assessed using reliable and well-validated measures administered to 34 house officers who were on call, compared with 27 house officers who were not on call. Negative mood increased from the pre- to post-24-hour period for house staff on call and decreased for house staff off call, yielding a significant interaction. State anxiety was significantly elevated for house officers who were on call.