462,819 research outputs found
Spatial Chow-Lin Methods for Data Completion in Econometric Flow Models
Full text linkFlow data across regions can be modeled by spatial econometric models, see LeSage and Pace (2009). Recently, regional studies became interested in the aggregation and disaggregation of flow models, because trade data cannot be obtained at a disaggregated level but data are published on an aggregate level. Furthermore, missing data in disaggregated flow models occur quite often since detailed measurements are often not possible at all observation points in time and space. In this paper we develop classical and Bayesian methods to complete flow data. The Chow and Lin (1971) method was developed for completing disaggregated incomplete time series data. We will extend this method in a general framework to spatially correlated flow data using the cross-sectional Chow-Lin method of Polasek et al. (2009). The missing disaggregated data can be obtained either by feasible GLS prediction or by a Bayesian (posterior) predictive density.Missing values in spatial econometrics, MCMC, non-spatial Chow-Lin (CL) and spatial Chow-Lin (SCL) methods, spatial internal flow (SIF) models, origin and destination (OD) data
中国云南象牙参属(姜科)一新种——苍山象牙参
No full textRoscoea cangshanensis M. H. Luo, X. F. Gao & H. H. Lin, a new species of the Zingiberaceae from Yunnan, China, is described and illustrated. The new species is related to R. forrestii Cowley in habit, but differs in having 2-lobed labellum, each lobe 2-lobulate, base narrowed to a stalk with white lines, and narrower leaf blade, (2-)7-24X1.5-2.5 cm, with base narrow to petiole-like. The new species is also similar to R. debilis Gagnep. in having leaf base narrow to petiole-like, labellum obovate-cuneate, 2.5-3.5X2.5-3.0 cm, with white lines at throat, but differs in having bracts non-tubular, shorter, 5-15 mm long, concealed in leaf sheaths, corolla tubes longer, 10-12.5 cm long, labellum. 2-lobed with each lobe further 2-lobulate
Singaporemma wulongensis Lin & Li 2014
No full textSingaporemma wulongensis Lin & Li, 2014 Figures 6E–e, 7F Singaporemma wulongensis Lin & Li, 2014: 46, figs 7–9, 17, 20B Examined material. Holotype ♂, paratypes 8♂ and 20♀ (NHMSU), CHINA: Chongqing, Wulong, Tudi Town, Tiansheng Village, Xiaodong Cave, 29°31.853'N, 107°50.817'E, altitude 1050 m, 17 October 2010, L. Dou and Y. Lin leg. Diagnosis. Male of S. wulongensis differs from males of all other congeners with the exception of S. bifurcata by the furcate embolus (Fig. 6E–e vs. Fig. 6A–D, 6a–d, 6G–H, 6g –h); it differs from male of S. bifurcata by the narrower, longer oval bulb, the embolus with two equilong tip branches, and the embolus starts from the submesialback surface of bulb, but the embolus of S. bifurcata with asymmetric branches that origins from prolateral surface of bulb (Fig. 6E–e vs. Fig. 6F–f). Female of S. wulongensis seems also close to S. bifurcata having a similar vulval structure, but it can be distinguished by the lager “ω”-shaped inner vulval plate, and the longer, weakly sclerotized central process (Fig. 7F vs. Fig. 7D). Description. See Lin & Li, 2014: 46. Distribution. China (Chongqing) (Fig. 10).Published as part of Yan, Fanhu & Lin, Yucheng, 2018, A review of the spider genus Singaporemma (Araneae: Tetrablemmidae), with the description of a new species, pp. 329-346 in Zootaxa 4392 (2) on pages 344-345, DOI: 10.11646/zootaxa.4392.2.6, http://zenodo.org/record/119544
Singaporemma bifurcata Lin & Li 2010
No full textSingaporemma bifurcata Lin & Li, 2010 Figures 1A–H, 2A–E, 6F–f, 8A Singaporemma bifurcata Lin & Li, 2010: 26, figs 29–37 Examined material. Topotypes 11♂ 25♀ (NHMSU), CHINA: Guizhou, Suiyang, Wenquan Town, Guihua Village, Hejiao Cave, 28°15´N, 107°17´E, altitude 695 m, 17 April 2015, Y. Lin and H. Yang leg. Diagnosis. With the exception of S. wulongensis, male of S. bifurcata can be distinguished from all other congeners by the embolus with an asymmetrically furcate end (Fig. 6f vs. Fig. 6a–d, 6g –h), and female of S. bifurcata differs by the stubby, sclerotized central process (Fig. 8A vs. Figs. 5C–D, 7A–C, 9A–B). S. bifurcata similar to S. wulongensis in the shape of palpal bulb and the configuration of vulva, but male of S. bifurcata can be distinguished from that of S. wulongensis by the starting position of embolus (Fig. 6F vs. Fig. 6E, the position indicated by the blue arrow) and the unequal length of branches of embolic tip (Fig. 6f vs. Fig. 6e); female of S. bifurcata separated by the smaller, “Ω”-shaped inner vulval plate, and the shorter central process (Fig. 8A vs. Fig. 8B). Description. See Figs 1A–H, 2A–E, 6F–f, 8A and Lin & Li, 2010: 26. Distribution. China (Guizhou) (Fig. 10).Published as part of Yan, Fanhu & Lin, Yucheng, 2018, A review of the spider genus Singaporemma (Araneae: Tetrablemmidae), with the description of a new species, pp. 329-346 in Zootaxa 4392 (2) on page 334, DOI: 10.11646/zootaxa.4392.2.6, http://zenodo.org/record/119544
Singaporemma banxiaoensis Lin & Li 2014
No full textSingaporemma banxiaoensis Lin & Li, 2014 Figures 6B–b, 7C Singaporemma banxiaoensis Lin & Li, 2014: 42, figs 4–6, 16C–D, 20A Examined material. Holotype ♂, paratypes 1♂ and 1♀ (IZCAS), CHINA: Guangxi, Pingxiang, Xiashi Town, Xinming Village, Banxiaotun, Banxiao Cave, 22°5.542'N, 106°52.148'E, altitude 175 m, 26 July 2011, X. Wang leg. Diagnosis. Male of this species is similar to S. halongense (Fig. 6A) and S. lenachanae (Fig. 6D), but can be distinguished from the latter two by the narrower, pointed embolic tip (Fig. 6b vs. Fig. 6a, 6d), and by the vestigial white eyespots lacking black ocular base in the both sexes (see Lin & Li, 2014: fig. 4G–H vs. Lin et al., 2017: figs 16E–F, 21A). Female is close to S. takensis sp. n. in having a similar configuration of vulva, but differs from the latter by the inverted triangular inner vulval plate, the wider, shorter central process (Fig. 7C vs. Fig. 5C–D). Description. See Lin & Li, 2014: 42. Distribution. China (Guangxi) (Fig. 10).Published as part of Yan, Fanhu & Lin, Yucheng, 2018, A review of the spider genus Singaporemma (Araneae: Tetrablemmidae), with the description of a new species, pp. 329-346 in Zootaxa 4392 (2) on page 331, DOI: 10.11646/zootaxa.4392.2.6, http://zenodo.org/record/119544
Gaseous [M - H]+ ions of alpha,omega-diphenylalkanes: cyclization to [M + H]+ type ions of benzocycloalkanes as recognized by chain-length dependent proton exchange
Full text linkKuck D. Gaseous [M - H]+ ions of alpha,omega-diphenylalkanes: cyclization to [M + H]+ type ions of benzocycloalkanes as recognized by chain-length dependent proton exchange. International Journal of Mass Spectrometry and Ion Processes. 1992;117(1-3):441-455.Metastable [M - H]+ ions of alpha,omega-diphenylalkanes C6H5(CH2)xC6H5 where x = 3-6 (structures 3-6 respectively), generated by hydride abstraction in the chemical ionization (i-butane) source, eliminate benzene after proton exchange between the aromatic rings. The proton exchange is slow for ions [3 - H]+ and [4 - H]+, but fast and apparently complete for ions [5 - H]+ and [6 - H]+. These observations, combined with collision activation experiments, suggest the cyclization of the [M - H]+ ions to isomeric protonated 1-phenylbenzocycloalkane and 1-benzylbenzocycloalkane derivatives, i.e. to [M1 + H]+ type ions, with a preference for protonated tetralin structures. Hydrogen exchange between the aliphatic chain and the rings is absent or negligible for [M - H]+ ions of 3-5 but is significant for ions [6 - H]+
SPATIAL CHOW-LIN METHODS: BAYESIAN AND ML FORECAST COMPARISONS
Full text linkCompleting data that are collected in disaggregated and heterogeneous spatial units is a quite frequent problem in spatial analyses of regional data. Chow and Lin (1971) (CL) were the rst to develop a uni ed framework for the three problems (interpolation, extrapolation and distribution) of predicting disaggregated times series by so-called indicator series. This paper develops a spatial CL procedure for disaggregating cross-sectional spatial data and compares the Maximum Likelihood and Bayesian spatial CL forecasts with the naive pro rata error distribution. We outline the error covariance structure in a spatial context, derive the BLUE for the ML estimator and the Bayesian estimation procedure by MCMC. Finally we
apply the procedure to European regional GDP data and discuss the disaggregation assumptions. For the evaluation of the spatial Chow-Lin procedure we assume that only NUTS 1 GDP is known and predict it at NUTS 2 by using employment and spatial information available at NUTS 2. The spatial neighborhood is de ned by the inverse travel time by car in minutes. Finally, we present the forecast accuracy criteria comparing the predicted values with the actual observations.
Leptotrombidium (Leptotrombidium) dongluoense Wang, Liao and Lin 1981
No full textLeptotrombidium (Leptotrombidium) dongluoense Wang, Liao and Lin, 1981: PAL Leptotrombidium (Leptotrombidium) dongluoensis Wang, Liao and Lin, 1981 [akamushi group] Leptotrombidium (Leptotrombidium) dongluoense, Li et al. 1997 Leptotrombidium dongluoense, Stekolnikov 2013 [4 group]Published as part of Nielsen, David H., Robbins, Richard G. & Rueda, Leopoldo M., 2021, Annotated world checklist of the Trombiculidae and Leeuwenhoekiidae (1758 - 2021) (Acari: Trombiculoidea), with notes on nomenclature, taxonomy, and distribution, pp. 1-243 in Zootaxa 4967 (1) on page 128, DOI: 10.11646/zootaxa.4967.1.1, http://zenodo.org/record/474551
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