Sources and Rates of Phosphorus in Improving Degraded Pasture in Brazilian West Amazon

The effects of phosphorus sources (triple superphosphate – TSP, single superphosphate – SSP and partially acidulated rock phosphate – PARP) and rates (0, 50 and 100 kg/ha of P2O5 on dry matter (DM) yields and chemical composition of a degraded Brachiaria brizantha cv. Marandu pasture were evaluated in a cutting trial. Phosphorus fertilization, irrespective of sources and rates, showed an effective agronomic technique for pasture recuperation. The grass DM yields and potassium contents were significantly improved by phosphorus application, while weed DM yields were depressed. Irrespective of sources and rates, crude protein, phosphorus, and calcium contents were not affected by phosphorus fertilization. The application of 100 kg of P2O5 /ha, as TSP, provided the highest grass yields, while for PARP it was observed the least effect of phosphorus fertilization

On isotropic cylindrically symmetric stellar models

We attempt to match the most general cylindrically symmetric vacuum space-time with a Robertson-Walker interior. The matching conditions show that the interior must be dust filled and that the boundary must be comoving. Further, we show that the vacuum region must be polarized. Imposing the condition that there are no trapped cylinders on an initial time slice, we can apply a result of Thorne's and show that trapped cylinders never evolve. This results in a simplified line element which we prove to be incompatible with the dust interior. This result demonstrates the impossibility of the existence of an isotropic cylindrically symmetric star (or even a star which has a cylindrically symmetric portion). We investigate the problem from a different perspective by looking at the expansion scalars of invariant null geodesic congruences and, applying to the cylindrical case, the result that the product of the signs of the expansion scalars must be continuous across the boundary. The result may also be understood in relation to recent results about the impossibility of the static axially symmetric analogue of the Einstein-Straus model.Comment: 13 pages. To appear in Classical and Quantum Gravit

LOTIS, Super-LOTIS, SDSS and Tautenburg Observations of GRB 010921

We present multi-instrument optical observations of the High Energy Transient Explorer (HETE-2)/Interplanetary Network (IPN) error box of GRB 010921. This event was the first gamma ray burst (GRB) localized by HETE-2 which has resulted in the detection of an optical afterglow. In this paper we report the earliest known observations of the GRB010921 field, taken with the 0.11-m Livermore Optical Transient Imaging System (LOTIS) telescope, and the earliest known detection of the GRB010921 optical afterglow, using the 0.5-m Sloan Digital Sky Survey Photometric Telescope (SDSS PT). Observations with the LOTIS telescope began during a routine sky patrol 52 minutes after the burst. Observations were made with the SDSS PT, the 0.6-m Super-LOTIS telescope, and the 1.34-m Tautenburg Schmidt telescope at 21.3, 21.8, and 37.5 hours after the GRB, respectively. In addition, the host galaxy was observed with the USNOFS 1.0-m telescope 56 days after the burst. We find that at later times (t > 1 day after the burst), the optical afterglow exhibited a power-law decline with a slope of $\alpha = 1.75 \pm 0.28$. However, our earliest observations show that this power-law decline can not have extended to early times (t < 0.035 day).Comment: AASTeX v5.x LaTeX 2e, 6 pages with 2 postscript figures, will be submitted to ApJ Letter

Toward a Unified Genetic Map of Higher Plants, Transcending the Monocot-Dicot Divergence

Closely related (confamilial) genera often retain large chromosomal tracts in which gene order is colinear, punctuated by structural mutations such as inversions and translocations 1. To explore the possibility that conservation of gene order might extrapolate to more distantly related taxa, we first estimated an average structural mutation rate. Nine pairs of taxa, for which there exist both comparative genetic maps and plausible estimates of divergence time, showed an average of0.14 (±0.06) structural mutations per chromosome per million years of divergence (Myr; Table 1). This value is offered as a first approximation, acknowledging that refined comparative data and/or divergence estimates may impel revision

Expedition 361 summary

International Ocean Discovery Program Expedition 361 drilled six sites on the southeast African margin (southwest Indian Ocean) and in the Indian-Atlantic Ocean gateway, from 30 January to 31 March 2016. In total, 5175 m of core was recovered, with an average recovery of 102%, during 29.7 days of on-site operations. The sites, situated in the Mozambique Channel at locations directly influenced by discharge from the Zambezi and Limpopo River catchments, the Natal Valley, the Agulhas Plateau, and Cape Basin, were targeted to reconstruct the history of the greater Agulhas Current system over the past ~5 My. The Agulhas Current is the strongest western boundary current in the Southern Hemisphere, transporting some 70 Sv of warm, saline surface water from the tropical Indian Ocean along the East African margin to the tip of Africa. Exchanges of heat and moisture with the atmosphere influence southern African climates, including individual weather systems such as extratropical cyclone formation in the region and rainfall patterns. Recent ocean model and paleoceanographic data further point at a potential role of the Agulhas Current in controlling the strength and mode of the Atlantic Meridional Overturning Circulation (AMOC) during the Late Pleistocene. Spillage of saline Agulhas water into the South Atlantic stimulates buoyancy anomalies that may influence basin-wide AMOC, with implications for convective activity in the North Atlantic and global climate change. The main objectives of the expedition were to establish the role of the Agulhas Current in climatic changes during the Pliocene–Pleistocene, specifically to document the dynamics of the Indian-Atlantic Ocean gateway circulation during this time, to examine the connection of the Agulhas leakage and AMOC, and to address the influence of the Agulhas Current on African terrestrial climates and coincidences with human evolution. Additionally, the expedition set out to fulfill the needs of Ancillary Project Letter number 845, consisting of high-resolution interstitial water sampling to help constrain the temperature and salinity profiles of the ocean during the Last Glacial Maximum. The expedition made major strides toward fulfilling each of these objectives. The recovered sequences allowed generation of complete spliced stratigraphic sections that range from 0 to between ~0.13 and 7 Ma. This sediment will provide decadal- to millennial-scale climatic records that will allow answering the paleoceanographic and paleoclimatic questions set out in the drilling proposal