UTe2 is a recently discovered unconventional superconductor that has attracted much interest because of its potentially spin-triplet topological superconductivity. Our ac calorimetry, electrical resistivity, and x-ray absorption study of UTe2 under applied pressure reveals key insights on the superconducting and magnetic states surrounding pressure-induced quantum criticality at Pc1 = 1.3 GPa. First, our specific heat data at low pressures, combined with a phenomenological model, show that pressure alters the balance between two closely competing superconducting orders. Second, near 1.5 GPa, we detect two bulk transitions that trigger changes in the resistivity, which are consistent with antiferromagnetic order, rather than ferromagnetism. Third, the emergence of magnetism is accompanied by an increase in valence toward a U4+ (5f2) state, which indicates that UTe2 exhibits intermediate valence at ambient pressure. Our results suggest that antiferromagnetic fluctuations may play a more substantial role on the superconducting state of UTe2 than previously thought.

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Life history of three catfish species (Siluriformes: Ariidae) from southeastern Brazil. Biota Neotrop. 12(4): http://www.biotaneotropica.org.br/v12n4/en/abstract?article+bn01912042012Abstract: This study evaluated the spatio-temporal distribution, reproduction and diet of the catfishes Genidens genidens, G. barbus and Aspistor luniscutis in Caraguatatuba Bay. Their sizes were recorded and the sex and reproductive stage identified. The abundance was compared between areas (South and North) and among months (August 2003 -October 2004. The species had different spatial distributions, allowing them to coexist. The temporal distribution reflected their tendencies to migrate in the reproductive period, as evidenced by the dominance of small immature individuals in the bay. G. genidens tended to reproduce in winter, and A. luniscutis in spring. The diet of G. genidens consisted of crustaceans, mollusks (shells), fish scales, ostracods, and bivalve siphons. G. barbus consumed a high proportion of mysids, followed by fish (bones and scales). For A. luniscutis, the diet was based on fish scales and crustaceans. High quantities of particulate organic matter were observed in the diet of all three species, as previously known for estuarine catfishes. The consumption of fish scales may reflect a lepidophagic habit. A small overlap was observed among the diets, reflecting differences in their environments as well as in the proportions of each item ingested. A distribuição temporal reflete sua tendência por migrar no períoo reprodutivo, evidenciado pela dominância de indivíduos pequenos e imaturos na enseada. Houve uma tendência de G. genidens reproduzir no inverno e A. luniscutis na primavera. G. genidens teve sua dieta constituida de crustáceos, moluscos (conchas), escamas de peixes, ostrácodes e sifões de bivalves. G. barbus revelou uma grande dominância por misidáceos, seguido por peixes (ossos e escamas). Para A. luniscutis, a dieta foi baseada em escamas de peixes e crustáceos. Grande quantidade de material orgânico particulado foi observado na dieta das espécies, como já conhecido para bagres estuarinos. O consumo de escamas de peixes pode refletir um hábito lepdofágico. Pequena sobreposição na dieta foi observada entre as espécies, refletindo distinções no ambiente como também nas proporções ingeridas de cada item. Palavras-chave: distribuição espaço-temporal, dieta, Genidens genidens, Genidens barbus, Aspistor luniscutis, Enseada de Caraguatatuba. 75Life history of three catfish

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