Summary 1.We studied chick diet in a known-age, sexed population of a long-lived seabird, the Brünnich's guillemot ( Uria lomvia ), over 15 years ( N = 136; 1993-2007) and attached time-depth-temperature recorders to examine foraging behaviour in multiple years ( N = 36; 2004-07). 2. Adults showed specialization in prey fed to offspring, described by multiple indices calculated over 15 years: 27% of diet diversity was attributable to among-individual variation (withinindividual component of total niche width = 0·73); average similarity of an individual's diet to the overall diet was 65% (mean proportional similarity between individuals and population = 0·65); diet was significantly more specialized than expected for 70% of individuals (mean likelihood = 0.53). These indices suggest higher specialization than the average for an across-taxa comparison of 49 taxa. 3. Foraging behaviour varied along three axes: flight time, dive depth and dive shape. Individuals showed specialized individual foraging behaviour along each axis. These foraging strategies were reflected in the prey type delivered to their offspring and were maintained over scales of hours to years. 4. Specialization in foraging behaviour and diet was greater over short time spans (hours, days) than over long time spans (years). Regardless of sex or age, the main component of variation in foraging behaviour and chick diet was between individuals. 5. Plasma stable isotope values were similar across years, within a given individual, and variance was low relative to that expected from prey isotope values, suggesting adult diet specialized across years. Stable isotope values were similar among individuals that fed their nestlings similar prey items and there was no difference in trophic level between adults and chicks. We suggest that guillemots specialize on a single foraging strategy regardless of whether chick-provisioning and self-feeding. With little individual difference in body mass and physiology, specialization likely represents learning and memorizing optimal feeding locations and behaviours. 6. There was no difference in survival or reproductive success between specialists and generalists, suggesting these are largely equivalent strategies in terms of evolutionary fitness, presumably because different strategies were advantageous at different levels of prey abundance or predictability. The development of individual specialization may be an important precursor to diversification among seabirds.

Thiazolidinedione (TZD) drugs used in the treatment of type 2 diabetes mellitus (T2DM) have proven effective in improving insulin sensitivity, hyperglycemia, and lipid metabolism. Though well tolerated by some patients, their mechanism of action as ligands of peroxisome proliferator-activated receptors (PPARs) results in the activation of several pathways in addition to those responsible for glycemic control and lipid homeostasis. These pathways, which include those related to inflammation, bone formation, and cell proliferation, may lead to adverse health outcomes. As treatment with TZDs has been associated with adverse hepatic, cardiovascular, osteological, and carcinogenic events in some studies, the role of TZDs in the treatment of T2DM continues to be debated. At the same time, new therapeutic roles for TZDs are being investigated, with new forms and isoforms currently in the pre-clinical phase for use in the prevention and treatment of some cancers, inflammatory diseases, and other conditions. The aims of this review are to provide an overview of the mechanism(s) of action of TZDs, a review of their safety for use in the treatment of T2DM, and a perspective on their current and future therapeutic roles.

Levels of ultraviolet B radiation (UVBR) reaching the Earth's surface have increased since the 1970s as a result of stratospheric ozone depletion caused by the emission of ozone-depleting substances (ODSs) such as chlorofluorocarbons. Despite international agreements to phase out harmful ODSs, these substances are persistent, and even under the most optimistic scenarios, stratospheric ozone levels will not return to pre-1980 levels for several decades. Furthermore, climate change may enhance chemical stratospheric ozone depletion. Global phenomena such as climate change, ozone depletion, and acidification of aquatic ecosystems interact to modify dissolved organic carbon levels in aquatic systems, thereby increasing the penetration of UVBR. Since amphibians inhabit both aquatic and terrestrial habitats and have unshelled eggs and permeable skin, they are vulnerable to changes in environmental conditions and habitat quality. Increased exposure of amphibians to UVBR can produce lethal and sublethal effects, especially in individuals that do not possess adequate defense mechanisms to protect themselves. In this article, we discuss worldwide increases in UVBR and the adverse effects of UVBR exposure on amphibians. Specifically, studies on the effects of UVBR on amphibian development and metamorphosis are summarized, and possible mechanisms of thyroid system disruption caused by UVBR exposure are considered.

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The objectives of this study were to assess the role of LFA-1 in enteric antigen (EAg)-induced activation of T-cells in vitro and in vivo and to define the importance of this integrin in promoting trafficking of T-cells to the MLNs and colon. We found that EAg-pulsed dendritic cells (DCs) induced proliferation of LFA-1-deficient (CD11a−/−) CD4+ T-cells that was very similar to that induced using WT T-cells suggesting that LFA-1 is not required for activation/proliferation of T-cells in vitro. Co-culture of WT or CD11a−/− T-cells with EAg-pulsed DCs induced the generation of similar amounts of INF-γ, IL-4 and IL-10 whereas IL-17A production was reduced approximately 2-fold in co-cultures with CD11a−/− T-cells. Short term (20-22 hr) trafficking studies demonstrated that while both WT and CD11a−/− T-cells migrated equally well into the spleen, liver, lungs, small intestine, cecum and colon, trafficking of CD11a−/− T-cells to the MLNs was reduced by 50% when compared to WT T-cells. When the observation period was extended from 3-7 days post transfer, we observed approximately 2-3 fold more WT T-cells within the MLNs and colon than CD11a−/− T-cells whereas T cell proliferation (as measured by CSFE dilution) was comparable in both populations. Taken together, our data suggest that LFA-1 is not required for EAg-induced activation of CD4+ T-cells in vitro or in vivo but is required for trafficking of T-cells to the MLNs and homing of colitogenic effector cells to the colon where they initiate chronic gut inflammation.