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181.
182.
In this paper we introduce a new testing procedure for evaluating the rationality of fixed‐event forecasts based on a pseudo‐maximum likelihood estimator. The procedure is designed to be robust to departures in the normality assumption. A model is introduced to show that such departures are likely when forecasters experience a credibility loss when they make large changes to their forecasts. The test is illustrated using monthly fixed‐event forecasts produced by four UK institutions. Use of the robust test leads to the conclusion that certain forecasts are rational while use of the Gaussian‐based test implies that certain forecasts are irrational. The difference in the results is due to the nature of the underlying data. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
183.
Dennis P. Gordon Judy E. Sutherland Brenda A. Perez Andrea Waeschenbach Paul D. Taylor Emanuela Di Martino 《Journal of Natural History》2020,54(15-16):947-970
ABSTRACT The status of Conopeum Gray, 1848 in New Zealand is clarified, confirming the presence of three living species – one a naturalised alien, one new to science, and a third that is also known in the Pleistocene. Conopeum seurati (Canu, 1928), a Mediterranean-European species, is naturalised at three localities in New Zealand – Opua, Whangarei Harbour and Whanganui Inlet. Conopeum antipodum n. sp., previously confused with C. seurati, is an estuarine species distributed from Kaipara Harbour to Lyttelton Harbour and is also found in Te Whanga Lagoon at Chatham Island (all New Zealand localities). Conopeum oretiensis Uttley, 1951, first described from Foveaux Strait, is known as far north as Kaipara and Manukau Harbours and is known as a Pleistocene fossil from Napier, New Zealand. There is one other solely fossil New Zealand species – Plio-Pleistocene Electra ongleyi Brown, 1952 is transferred to Conopeum. Sequence data from the 18SrDNA locus confirm that Conopeum antipodum n. sp. is resolved within Conopeum and is distinct from C. seurati. http://www.zoobank.org/urn:lsid:zoobank.org:act:4FED6730-1C70-4420-B1DA-F1D9046221DF http://www.zoobank.org/urn:lsid:zoobank.org.pub:5C130A99-0869-44A2-885C-338005FBCE07 相似文献
184.
185.
Nicholas Taylor 《Journal of forecasting》2008,27(8):721-742
This paper examines the benefits to forecasters of decomposing close-to-close return volatility into close-to-open (nighttime) and open-to-close (daytime) return volatility. Specifically, we consider whether close-to-close volatility forecasts based on the former type of (temporally aggregated) data are less accurate than corresponding forecasts based on the latter (temporally disaggregated) data. Results obtained from seven different US index futures markets reveal that significant increases in forecast accuracy are possible when using temporally disaggregated volatility data. This result is primarily driven by the fact that forecasts based on such data can be updated as more information becomes available (e.g., information flow from the preceding close-to-open/nighttime trading session). Finally, we demonstrate that the main findings of this paper are robust to the index futures market considered, the way in which return volatility is constructed, and the method used to assess forecast accuracy. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
186.
We have analysed a suite of 12 state-of-the-art climate models and show that ocean warming and sea-level rise in the twentieth century were substantially reduced by the colossal eruption in 1883 of the volcano Krakatoa in the Sunda strait, Indonesia. Volcanically induced cooling of the ocean surface penetrated into deeper layers, where it persisted for decades after the event. This remarkable effect on oceanic thermal structure is longer lasting than has previously been suspected and is sufficient to offset a large fraction of ocean warming and sea-level rise caused by anthropogenic influences. 相似文献
187.
Taylor M. J. Reading M. Sheehan J. F. Mulhaney A. 《Systemic Practice and Action Research》2001,14(3):239-249
Although there are technical standards and guides relating to specific aspects of computer network development and implementation, there appear to be no overall frameworks or approaches aimed specifically at computer network development and implementation, particularly those that are smaller in scale. In this paper the application of an action research approach to the technically oriented process of computer network development and implementation is examined. In particular, this paper examines the soft issues relating to small-scale computer network development and implementation encountered in a 2-year project in a small engineering company. 相似文献
188.
A new approach to protein fold recognition. 总被引:80,自引:0,他引:80
The prediction of protein tertiary structure from sequence using molecular energy calculations has not yet been successful; an alternative strategy of recognizing known motifs or folds in sequences looks more promising. We present here a new approach to fold recognition, whereby sequences are fitted directly onto the backbone coordinates of known protein structures. Our method for protein fold recognition involves automatic modelling of protein structures using a given sequence, and is based on the frameworks of known protein folds. The plausibility of each model, and hence the degree of compatibility between the sequence and the proposed structure, is evaluated by means of a set of empirical potentials derived from proteins of known structure. The novel aspect of our approach is that the matching of sequences to backbone coordinates is performed in full three-dimensional space, incorporating specific pair interactions explicitly. 相似文献
189.
Yokoyama S Woods SL Boyle GM Aoude LG MacGregor S Zismann V Gartside M Cust AE Haq R Harland M Taylor JC Duffy DL Holohan K Dutton-Regester K Palmer JM Bonazzi V Stark MS Symmons J Law MH Schmidt C Lanagan C O'Connor L Holland EA Schmid H Maskiell JA Jetann J Ferguson M Jenkins MA Kefford RF Giles GG Armstrong BK Aitken JF Hopper JL Whiteman DC Pharoah PD Easton DF Dunning AM Newton-Bishop JA Montgomery GW Martin NG Mann GJ Bishop DT Tsao H Trent JM Fisher DE Hayward NK Brown KM 《Nature》2011,480(7375):99-103
190.
Tissue wounding induces the rapid recruitment of leukocytes. Wounds and tumours--a type of 'unhealed wound'--generate hydrogen peroxide (H(2)O(2)) through an NADPH oxidase (NOX). This extracellular H(2)O(2) mediates recruitment of leukocytes, particularly the first responders of innate immunity, neutrophils, to injured tissue. However, the sensor that neutrophils use to detect the redox state at wounds is unknown. Here we identify the Src family kinase (SFK) Lyn as a redox sensor that mediates initial neutrophil recruitment to wounds in zebrafish larvae. Lyn activation in neutrophils is dependent on wound-derived H(2)O(2) after tissue injury, and inhibition of Lyn attenuates neutrophil wound recruitment. Inhibition of SFKs also disrupted H(2)O(2)-mediated chemotaxis of primary human neutrophils. In vitro analysis identified a single cysteine residue, C466, as being responsible for direct oxidation-mediated activation of Lyn. Furthermore, transgenic-tissue-specific reconstitution with wild-type Lyn and a cysteine mutant revealed that Lyn C466 is important for the neutrophil wound response and downstream signalling in vivo. This is the first identification, to our knowledge, of a physiological redox sensor that mediates leukocyte wound attraction in multicellular organisms. 相似文献