The merger history of massive spheroids since z ∼ 1 is size independent

Using a compilation of 379 massive (stellar mass M ≳ 10^11 M_⊙) spheroid-like galaxies from the near-infrared Palomar/DEEP-2 survey, we investigated, up to z ∼ 1, whether the presence of companions depends on the size of the host galaxy. We explored the presence of companions for mass ratios with respect to the central massive galaxy down to 1 : 10 and 1 : 100, and within projected distances of 30, 50 and 100 kpc of these objects. We found evidence that these companions are equally distributed around both compact and extended massive spheroid-like galaxies. This suggests that, at least since z ∼ 1, the merger activity in these objects is nearly homogeneous across the whole population and that the merger history is not affected by the size of the host galaxy. Our results could indicate that compact and extended massive spheroid-like galaxies are increasing in size at the same rate.

Emergent Brazil and the Curse of the ‘Hen’s Flight’. CEPS Working Document No. 379, 27 February 2013

The ‘Emergent Brazil’ growth model is reaching its limits. Its main engines have been slowing significantly since the beginning of the global financial and economic crisis. Even its much-praised predictable macroeconomic policy has been eroded by political interference. Inflationary pressures are growing and GDP performance is anaemic. As ominous, Brazil cannot compensate for its domestic deficiencies with an export drive. Commodity exports are suffering with the world economic slow-down and the manufacturing industries’ competitiveness is in sharp decline. Brazil has put all its trade negotiation eggs into the South American and WTO baskets, and now its export market share is threatened by the Doha Round paralysis, the Latin American Alianza del Pacífico, and the US-led initiatives for a Trans-Pacific Partnership and a trade and investment agreement with the EU. Paradoxically, this alarming situation opens a window of opportunity. There is a mounting national consensus on the need to tackle head-on the country’s and its industries’ lack of competitiveness. That means finding a solution to the much-decried ‘Brazil Cost’ and stimulating private-sector investment. It also entails an aggressive trade-negotiating stance in order to secure better access to foreign markets and to foster more competition in the domestic one. The most promising near-term goal would be the conclusion of the EU–Mercosur trade talks. A scenario to overcome the paralysis of these negotiations could trail two parallel paths: bilateral EU–Brazil agreements on ‘anything but trade’ combined with a sequencing of the EU–Mercosur talks where each member of the South American bloc could adopt faster or slower liberalisation commitments and schedules.

Sm-Nd isotope and Mn/Ca ratios for cleaned Neogloboquadrina pachyderma from ODP Hole 105-647A (Table 1)

The neodymium (Nd) isotope composition of ancient seawater is a potentially useful tracer of changes in continental inputs and ocean circulation on timescales of a few ka. Here we present the first Nd isotope record for seawater using sedimentary foraminifera cleaned using standard oxidative-reductive techniques. The data, along with Mn/Ca ratios, suggest that cleaned foraminifera provide a reliable record of Nd in seawater and hold out the prospect of using Nd in foraminifera to examine changes in seawater that accompany glacial-interglacial climatic cycles. The principal potential problem to be overcome with the use of forams as records of trace elements in ancient seawater is their diagenetic Fe-Mn coatings. These contain large amounts of Nd and other trace elements but can be cleaned off using highly reducing reagents. Mn(Ca ratios for the majority of the cleaned sedimentary foraminifera analysed here lie within the range (10-100 µmol/mol) that has yielded success in studies of transition elements in forams. Mass-balance modelling suggests that for residual Mn/Ca ratios <100 µmol/mol, Nd added to the foram in the coating will never shift the measured Nd isotope composition significantly away from the seawater value acquired by the foram test in the water column. Additionally, Nd concentrations measured in cleaned sedimentary foraminifera are comparable with those for a modern sample that has never encountered diagenetic fluids. Finally, core-top planktonic foraminifera for two sites have Nd isotope compositions that are identical to local surface seawater. The data we present here for Labrador Sea forams over the past 2.5 m.y. are interpreted in terms of changes in the seawater isotopic composition. The data show a pronounced shift from epsilon-Nd values of ~-12 to ~-19 in the period 2.5-1.5 Ma. This change is interpreted to result from the initiation of Northern Hemisphere glaciation and the increased derivation of Labrador Sea Nd via ice-rafting from Archaean terranes in central Canada. In combination with stable isotope and foraminiferal relative species abundance data, the new Nd data are consistent with the surface hydrography of the Labrador Sea being dominated by a fluctuating balance between cold, polar waters containing unradiogenic Nd and warm, subtropical waters containing more radiogenic Nd. The major change in Labrador Sea Nd that is observed in the past 2.5 Ma can, on its own, account for the change in the Nd isotope composition of North Atlantic Deep Water over the same time period.