2,417 research outputs found
Tussen Onderdanen, Rijksgenoten en Nederlanders : Nederlandse politici over burgers uit Oost en West en Nederland, 1945-2005
Spijkerboer, T.P. [Promotor]Walsum, S.K. van [Copromotor
Pretender punishment induced by chemical signalling in a queenless ant
Animal societies are stages for both conflict and cooperation. Reproduction is often monopolized by one or a few individuals who behave aggressively to prevent subordinates from reproducing (for example, naked mole-rats, wasps and ants). Here we report an unusual mechanism by which the dominant individual maintains reproductive control. In the queenless ant Dinoponera quadriceps, only the alpha female reproduces. If the alpha is challenged by another female she chemically marks the pretender who is then punished by low-ranking females. This cooperation between alpha and low-rankers allows the alpha to inflict punishment indirectly, thereby maintaining her reproductive primacy without having to figh
Letter from G.R. Jones to James B. Finley
Greenberry Jones, Presiding Elder of the Scioto District, tells of his interest in the Indian Mission. He has felt a lively interest in the red brethren since my acquaintance with them. He summarizes the work of his district as follows: In this district we have rather dull times with the exception of Deer Creek and Columbus Circuits where there is good work especially in Columbus. Abstract Number - 679https://digitalcommons.owu.edu/finley-letters/1773/thumbnail.jp
Reconstructing El Niño Southern Oscillation using data from ships’ logbooks, 1815–1854. Part II: Comparisons with existing ENSO reconstructions and implications for reconstructing ENSO diversity
© 2017 The Author(s) A systematic comparison of El Niño Southern Oscillation reconstructions during the early to mid-nineteenth century is presented using a range of proxy and documentary sources. Reconstructions of the boreal winter Southern Oscillation Index (SOI) using data from ships’ logbooks presented in a companion paper are evaluated and compared to previous ENSO reconstructions. Comparisons between ENSO reconstructions and the instrumental SOI during a period of overlap (1876–1977) are made. These same proxy and documentary reconstructions are then compared to the logbook-based reconstructions, over 1815–1854. The logbook-based reconstructions compare best with a recent multi-proxy reconstruction that used signals taken from different teleconnection regions, and they have an improved agreement with multi-proxy records compared to a previous attempt to reconstruct the SOI from ships’ logbook data. The logbook-based and the multi-proxy reconstructions are found to capture El Niño events better than La Niña events, and East Pacific El Niño events better than Central Pacific El Niño events, thus suggesting a degree of bias in the historical reconstructions. These findings have important implications for future ENSO reconstructions, with a need for an increased understanding of the effects of different ENSO flavours for future reconstructions
Early-nineteenth-century southern African precipitation reconstructions from ships' logbooks
Atmospheric circulation in the oceans surrounding southern Africa plays an important role in determining its precipitation. This study uses wind information recorded in ships’ logbooks in order to statistically reconstruct summer and winter season precipitation at four southern African weather stations from 1796 to 1854. The reconstruction was obtained by first relating gridded 8° × 8° NCEP-DOE reanalysis seasonal mean wind vectors in the adjacent oceans to station precipitation. Over a 30-year calibration period (1979–2008), significant correlations between wind and precipitation at Cape Town, Mthatha and Royal National Park showed particular correspondence with those areas with the greatest concentration of logbook observations. Principal component regression was used to assess the potential of the dominant patterns of variability in the wind vectors as predictors to reconstruct precipitation. Cross-validation in the calibration period gave confidence that precipitation could be reconstructed at several stations across South Africa, meaning the regression relationships derived in the calibration period could be applied to the gridded seasonal mean logbook data to produce reconstructions of precipitation from 1796 to 1854. The reconstructions show a degree of correspondence with other regional data sets. For instance, the decade beginning in 1810 was the wettest of the period at Mthatha and Royal National Park, while the 1820s were the driest. At Cape Town, the 1820s were the wettest decade, with drier conditions observed in the 1830s. An index of west–east circulation in the summer season revealed correspondence with two documentary reconstructions of El Niño events and increased westerliness, although this did not always result in drier conditions. Attention is also drawn to the remaining 3000 yet to be digitised English East India Company logbooks which would provide a high-resolution picture of atmospheric circulation back to 1700 in the region under consideration
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The use of coconut oil/diesel blends as a fuel for compression ignition engines (ODNRI Bulletin No. 31)
This bulletin describes experimental and evaluative work carried out by the Overseas Development Natural Resources Institute (ODNRI) to investigate fuelling of a standard compression ignition engine with blends of coconut oil and diesel. Initial studies were made of fuel-related properties for pure coconut oil and for a full range of blends with diesel. A major upgrading of the standard engine's fuel filtration system was necessary but thereafter it was found that a blend of 80% coconut oil in diesel, when heated to 45°C, provided a technically feasible substitute fuel. A limited duration engine trial was completed with this alternative arrangement to assess maintenance and operational requirements. On the basis of these results a preliminary economic evaluation was made of the potential for wider adoption of this type of substitute fuelling. Whilst this indicated that at prevailing prices of coconut oil relative to diesel this was unattractive, circumstances were identified in which this technology could have potential application
Assessing the ecological effects of management zoning on inshore reefs of the Great Barrier Reef Marine Park: Reef 2050 Integrated Monitoring and Reporting Program milestone report 2
[Extract] This RIMReP project builds upon a long-term monitoring program that assesses the ecological effects of management zoning on high-use and high-value inshore coral reefs of the Great Barrier Reef Marine Park (GBRMP). The monitoring program aims to track the status and condition of benthic (coral and algae) and fish communities and quantify the ecological effects of no-take marine reserves (green zones, NTRs). It is one of the few systematic long-term monitoring projects conducted on GBRMP reefs that specifically assesses temporal dynamics in reef communities and the ecological effects of zoning managemen
ATCA radio detection of the new X-ray transient MAXI J1813-095 as a candidate radio-quiet black hole X-ray binary
We observed the new X-ray transient MAXI J1813-095 (ATels #11323, #11326, #11332) with the Australia Telescope Compact Array (ATCA) between 2018-02-22 20:52 UT and 2018-02-23 02:59 UT. Our observations were taken simultaneously at 5.5 and 9 GHz, with a bandwidth of 2 GHz at each frequency
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