Biodiversity, Disparity and Evolvability

A key problem in conservation biology is how to measure biological diversity. Taxic diversity (the number of species in a community or in a local biota) is not necessarily the most important aspect, if what most matters is to evaluate how the loss of the different species may impact on the future of the surviving species and communities. Alternative approaches focus on functional diversity (a measure of the distribution of the species among the different 'jobs' in the ecosystem), others on morphological disparity, still others on phylogenetic diversity. There are three major reasons to prioritize the survival of species which provide the largest contributions to the overall phylogenetic diversity. First, evolutionarily isolated lineages are frequently characterized by unique traits. Second, conserving phylogenetically diverse sets of taxa is valuable because it conserves some sort of trait diversity, itself important in so far as it helps maintain ecosystem functioning, although a strict relationships between phylogenetic diversity and functional diversity cannot be taken for granted. Third, in this way we maximize the "evolutionary potential" depending on the evolvability of the survivors. This suggests an approach to conservation problems focussed on evolvability, robustness and phenotypic plasticity of developmental systems in the face of natural selection: in other terms, an approach based on evolutionary developmental biology

Kinetic study of electro-oxidation of formic acid on spontaneously-deposited Pt/Pd nanoparticles - CO tolerant fuel cell chemistry

Pt/Pd catalysts have recently been found to have exceptional properties in formic acid fuel cells. In this paper, the kinetics of formic acid electro-oxidation on spontaneously-deposited Pt/Pd nanoparticles were measured to provide a basis for fuel cell design. The results confirmed previous findings that palladium covered platinum catalysts showed exceptional activity for formic acid electro-oxidation. The Pt/Pd catalysts were a factor of thirty more active than Pt under the conditions examined. The catalysts also continued to function as CO built up on the catalyst surface and showed reasonable activity. Thus, the catalysts were CO tolerant. In addition, the results showed that the Tafel slope of formic acid electro-oxidation on Pt/Pd was time dependent. Generally, the Tafel slope decreased as COad was deposited on the surface, suggesting a change in rate determining step with CO coverage. The formic acid concentration effect was also studied in detail to give guidance to the practical fuel cell design. Similar studies on Pt nanoparticles were performed for comparison. (C) 2003 The Electrochemical Society

Infliximab is not associated with increased risk of malignancy or hemophagocytic lymphohistiocytosis in pediatric patients with inflammatory bowel disease

BACKGROUND AND AIMS: Immunosuppressive therapy for inflammatory bowel disease (IBD) in pediatric patients is thought to increase the risk of malignancy and lymphoproliferative disorders, including hemophagocytic lymphohistiocytosis (HLH). We compared unadjusted incidence rates of malignancy and HLH in pediatric patients with IBD exposed to infliximab (IFX) with patients not exposed to biologics and calculated standardized incidence ratios (SIRs). METHODS: We collected and analyzed data from 5766 participants in a prospective study of long-term outcomes of pediatric patients with IBD (NCT00606346), from May 31, 2007 through June 30, 2016. Patients were 17 years old or younger and had Crohn's disease, ulcerative colitis, or IBD-unclassified with 24,543.0 patient-years of follow-up. We estimated incidence rates for malignancy and HLH as events/1000 patient-years of follow-up. We calculated age-, sex-, and race-adjusted SIRs, with 95% confidence intervals (CIs), using the Surveillance, Epidemiology, and End Results Program (SEER) database. RESULTS: Thirteen of the 15 patients who developed a malignancy and all 5 of the patients who developed HLH had been exposed to thiopurines; 10 patients with malignancy had also been exposed to a biologic agent. Unadjusted incidence rates showed no increased risk of malignancy (0.46/1000 patient-years) or HLH (0.0/1000 patient-years) in patients exposed to IFX as the only biologic vs those unexposed to biologics (malignancy: 1.12/1000 patient-years; HLH: 0.56/1000 patient-years). SIRs did not demonstrate an increased risk of malignancy among patients exposed to IFX (SIR, 1.69; 95% CI, 0.46-4.32) vs patients not exposed to a biologic agent (SIR, 2.17; 95% CI, 0.59-5.56), even when patients were stratified by thiopurine exposure. CONCLUSIONS: In determination of age-, sex-, and race-adjusted SIRs using data from a large clinical study and the SEER database, we found that IFX exposure did not associate with increased risk of malignancy or HLH in pediatric patients with IBD. Thiopurine exposure is an important precedent event for the development of malignancy or HLH in pediatric patients with IBD