The Messy Teaching Conversation: Toward a Model of Collegial Reflection, Exchange, and Scholarship on Classroom Problems

Whether we teach in junior or senior colleges, we often represent our teaching in the best possible light, leaving little room for acknowledgment or discussion of uncertainty or errors. It seems that the only way to discuss a set back is as part of a larger narrative, one where a failure is simply a precursor to success, a way of highlighting a challenge overcome.This wall of silence about our messes prevents us from honestly discussing our day-to-day work in the classroom. This article models just such a messy teaching conversation

Adaptive plasticity of killifish (Fundulus heteroclitus) embryos: dehydration-stimulated development and differential aquaporin-3 expression

13 pages, 7 figures, 3 tablesEmbryos of the marine killifish Fundulus heteroclitus are adapted to survive aerially. However, it is unknown if they are able to control development under dehydration conditions. Here, we show that air-exposed blastula embryos under saturated relative humidity were able to stimulate development, and hence the time of hatching was advanced with respect to embryos continuously immersed in seawater. Embryos exposed to air at later developmental stages did not hatch until water was added, while development was not arrested. Air-exposed embryos avoided dehydration probably because of their thickened egg envelope, although it suffered significant evaporative water loss. The potential role of aquaporins as part of the embryo response to dehydration was investigated by cloning the aquaporin-0 (FhAqp0), -1a (FhAqp1a), and -3 (FhAqp3) cDNAs. Functional expression in Xenopus laevis oocytes showed that FhaAqp1a was a water-selective channel, whereas FhAqp3 was permeable to water, glycerol, and urea. Expression of fhaqp0 and fhaqp1a was prominent during organogenesis, and their mRNA levels were similar between water- and air-incubated embryos. However, fhaqp3 transcripts were highly and transiently accumulated during gastrulation, and the protein product was localized in the basolateral membrane of the enveloping epithelial cell layer and in the membrane of ingressing and migrating blastomers. Interestingly, both fhaqp3 transcripts and FhAqp3 polypeptides were downregulated in air-exposed embryos. These data demonstrate that killifish embryos respond adaptively to environmental desiccation by accelerating development and that embryos are able to transduce dehydration conditions into molecular responses. The reduced synthesis of FhAqp3 may be one of these mechanisms to regulate water and/or solute transport in the embryo.This study was supported by the European Commission New and Emerging Science and Technologies (NEST) program (contract no. 012674-2 Sleeping Beauty) and by a grant from the Spanish Ministry of Education and Science (MEC; AGL2004-00316/ACU) to J. Cerda`. Participation of C. Zapater and F. Chauvigne´ was financed by a predoctoral fellowship from MEC (Spain) and by the European Commission [Marie Curie Research Training Network Aqua (glycero)porins, MRTN-CT-2006-035995], respectively.Peer reviewe

Antioxidant therapies in COPD

Oxidative stress is an important feature in the pathogenesis of COPD. Targeting oxidative stress with antioxidants or boosting the endogenous levels of antioxidants is likely to be beneficial in the treatment of COPD. Antioxidant agents such as thiol molecules (glutathione and mucolytic drugs, such as N-acetyl-L-cysteine and N-acystelyn), dietary polyphenols (curcumin, resveratrol, green tea, catechins/quercetin), erdosteine, and carbocysteine lysine salt, all have been reported to control nuclear factor-kappaB (NF-κ B) activation, regulation of glutathione biosynthesis genes, chromatin remodeling, and hence inflammatory gene expression. Specific spin traps such as α-phenyl-N-tert-butyl nitrone, a catalytic antioxidant (ECSOD mimetic), porphyrins (AEOL 10150 and AEOL 10113), and a superoxide dismutase mimetic M40419 have also been reported to inhibit cigarette smoke-induced inflammatory responses in vivo. Since a variety of oxidants, free radicals, and aldehydes are implicated in the pathogenesis of COPD, it is possible that therapeutic administration of multiple antioxidants will be effective in the treatment of COPD. Various approaches to enhance lung antioxidant capacity and clinical trials of antioxidant compounds in COPD are discussed