Adolescents with Learning Disabilities

The subjective experiences of adolescents with learning disabilities (LD) were compared to those of their low-achieving and normally achieving peers. Three groups of juniors and seniors from one suburban high school district, 18 students with learning disabilities (15 males, 3 females), 17 low-achieving students (12 males, 5 females), and 20 average-achieving students (12 males, 8 females), were given electronic pagers and booklets for 1 week. They were signaled every 40 minutes during school hours, and every 2 hours after school. As soon as possible after receiving a signal, they responded to questions in their booklets. The questions provided subjective measures on levels of affect, activation, cognitive efficiency, self-esteem, motivation, and feedback from others. The students with learning disabilities reported feeling more positive and active than either of the other groups during school hours, while after school there were no differences on any of the subjective measures for the three groups. Specific LD school practices are highlighted for their probable impact on the heightened affect and activation of the students with learning disabilities.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68706/2/10.1177_002221949302600912.pd

Secretory structures in plants: lessons from the Plumbaginaceae on their origin, evolution and roles in stress tolerance

Special IssueThe Plumbaginaceae (non-core Caryophyllales) is a family well known for species adapted to a wide range of arid and saline habitats. Of its salt-tolerant species, at least 45 are in the genus Limonium; two in each of Aegialitis, Limoniastrum and Myriolimon, and one each in Psylliostachys, Armeria, Ceratostigma, Goniolimon and Plumbago. All the halophytic members of the family have salt glands, which are also common in the closely related Tamaricaceae and Frankeniaceae. The halophytic species of the three families can secrete a range of ions (Na+, K+, Ca2+, Mg2+, Cl−, HCO3 −, SO4 2-) and other elements (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn). Salt glands are, however, absent in salt-tolerant members of the sister family Polygonaceae. We describe the structure of the salt glands in the three families and consider whether glands might have arisen as a means to avoid the toxicity of Na+ and/or Cl− or to regulate Ca2+ concentrations within the leaves. We conclude that the establishment of lineages with salt glands took place after the split between the Polygonaceae and its sister group the Plumbaginaceaeinfo:eu-repo/semantics/publishedVersio