145,108 research outputs found
Notes on the Flora of Taiwan (35) — Scutellaria taipeiensis T. C. Huang, A. Hsiao et M. J. Wu sp. nov. (Lamiaceae)
No full textA comparative study of corolla types, pollen features, nutlet coat ornamentation and
chromosome numbers of Scutellaria (Lamiaceae) species in Taiwan has been conducted. The result
reveals that we have a new species so that Scutellaria taipeiensis T. C. Huang, A. Hsiao et M. J. Wu
sp. nov. is here proposed. A key to the species, species description and illustrations, and other relevant
information are provided
Analyse des signaux multicomposante à modulation de fréquence linéaire par la transformation de Teager-Huang-Hough
Get PDFA novel detection approach of linear FM (LFM) signals, with single or multiple components, in the time-frequency plane of Teager-Huang (TH) transform is presented. The detection scheme that combines TH transform and Hough transform is referred to as Teager-Huang-Hough (THH) transform. The input signal is mapped into the time-frequency plane by using TH transform followed by the application of Hough transform to recognize time-frequency components. LFM components are detected and their parameters are estimated from peaks and their locations in the Hough space. Advantages of THH transform over Hough transform of Wigner-Ville distribution (WVD) are: 1) cross-terms free detection and estimation, and 2) good time and frequency resolutions. No assumptions are made about the number of components of the LFM signals and their models. THH transform is illustrated on multicomponent LFM signals in free and noisy environments and the results compared with WVD-Hough and pseudo-WVD-Hough transforms
Investigating the linkages between industrial policies and M&A dynamics: Evidence from China
No full textMergers and acquisitions (M&As hereafter) have been widely examined in the economic and business literature under many perspectives. However, the industry-level view, specifically the relation between industrial policies and M&A waves at the sectoral level, has remained rather unexplored. This article contributes to fill this gap by empirically investigating the relation between selective industrial policies and M&A waves at the industry level in China. Referring to the four Five Year Plans covering the period 1996–2015, we explore whether being identified as an emerging sector in these plans generates positive or negative changes in the number of M&As. We reiterate the analysis according to the different types of M&As (vertical, horizontal or conglomerate) and the different natures of the acquirer (SOEs or private). Our results suggest that policies can differentially affect M&A waves according to the type of M&A. Moreover, while private firms are more responsive to both horizontal and vertical integration in emerging sectors, SOEs are more prone to engage in vertical M&As. We discuss the possible rationales behind the different behaviors. We also draw general policy implications on strategic industrial policy and market restructuring
Flavonoids and anthraquinones from Murraya tetramera C. C. Huang (Rutaceae)
No full textPhytochemical investigation of Murraya tetramera C. C. Huang led to the isolation of ten flavonoids (1-10) and three anthraquinones (11-13). Their structures were determined on the basis of MS, NMR, specific optical rotation, and CD spectroscopic data analysis, and by comparison of the obtained data with those reported in the literature. This is the first report for the occurrence of compounds 2, 4-7, and 11-13 in the Murraya species, and all the compounds were isolated from M. tetramera for the first time with the exception of compound 3. The chemotaxonomic significance of these compounds was also discussed. (C) 2014 Elsevier Ltd. All rights reserved.Biochemistry & Molecular BiologyEcologyEvolutionary BiologySCI(E)[email protected]
Miltochrista dongi Huang & Volynkin 2021, sp. n.
No full textMiltochrista dongi Huang & Volynkin, sp. n. (Figs 4, 11) Type material. Holotype (Figs 4, 11): male, “ 3.V.2018, altitude 2100 m, Mt. Dawei, Pingbian Miao Autonomous County, Honghe Hani and Yi Autonomous Prefecture, Yunnan Province, P. R. China, leg. Si-yao Huang & Tian-tian Yu” [in Chinese], prep. in glycerol by Huang (Coll. SCAU). Diagnosis. Miltochrista dongi sp. n. differs externally from its closest relative M. xihe sp. n. by its smaller size, the narrower forewing, the blackish abdomen (it is dark brown in M. xihe sp. n.), the crimson forewing ground color (it is pale red in M. xihe sp. n.), the presence of a wide blackish patch in the medial part of the forewing from the base to the subterminal area, and the blackish brown hindwing (it is dark brown in M. xihe sp. n.). The wing pattern of M. dongi sp. n. is also somewhat reminiscent of that of Ovipennis (Coccinigripennis) miloslavae (Černý, 2016) from southern Vietnam, but can be readily distinguished from the latter by its larger blackish patch which extends to the wing base (whereas it is not reaching the wing base in O. (C.) miloslavae) and the findamentally different male genitalia structure. The male genital capsule of M. dongi sp. n. is similar to that of M. xihe sp. n., but differs by the valva narrower medially and basally, the conspicuously narrower distal lobe of valva, and the slightly weaker distal saccular process. The aedeagus of the new species is slightly narrower and less elongated in comparison to the genital capsule of M. xihe sp. n. The vesica of M. dongi sp. n. differs clearly from that of M. xihe sp. n. by its narrower main chamber, the absence of spines on the ventral diverticulum, the smaller distal diverticulum bearing a smaller number of spines, and the markedly larger distal plate. Description. External morphology of adults. Forewing length 10 mm in holotype male. Male antenna ciliate, blackish. Legs blackish brown. Head and thorax crimson. Abdomen dark brown. Forewing blackish brown, edged with crimson, with blackish suffusion on veins in the subterminal and terminal areas; cilia crimson. Hindwing blackish brown including cilia. Male genitalia. Uncus long, thin, laterally flattened, curved subapically and apically pointed. Tuba analis moderately broad; scaphium thin, weakly sclerotized; subscaphium presented as setose field. Tegumen short, moderately broad and weakly sclerotized. Juxta shield-like with very deep lower triangular concavity. Valva elongated, narrow, its costal margin convex medially. Costa strongly broadened distally, lacks a distal process. Distal lobe of valva large, with apical moderately sclerotized triangular process. Sacculus with weakly setose dorsal margin. Distal saccular process narrow but robust, elongate, slightly S-like curved and apically blunt. Aedeagus elongated, straight. Vesica broad, with more or less globular main chamber; its ventral diverticulum small, heavily granulated; medial diverticulum broad, globular, bears a series of various-sized robust spines; distal diverticulum short, granulated, bears a cluster of several various-sized spines. Distal plate of vesica broadly triangular, moderately sclerotized. Female unknown. Distribution. The species is known from its type locality only, Mount Dawei in Yunnan Province of China. Etymology. The species is dedicated to Mr. Zhi-wei Dong (Kunming, China), a good friend of the second author who helped him during his trip to Mount Dawei.Published as part of Volynkin, Anton V. & Huang, Si-Yao, 2021, Three new peculiar species of the genus Miltochrista Hübner, [1819] from China (Lepidoptera, Erebidae, Arctiinae), pp. 569-576 in Zootaxa 4970 (3) on page 571, DOI: 10.11646/zootaxa.4970.3.8, http://zenodo.org/record/476688
More on Soft Theorems: Trees, Loops and Strings
Get PDFThe work of S. H. is
supported by Zurich Financial Services Membership and
the Ambrose Monell Foundation. The work of Y.-t. H. is
supported by the National Science Foundation Grant
No. PHY-1314311 and MOST Grant No. 103-2112-M002-025-MY3.
The work of C. W. is supported by the
Science and Technology Facilities Council Consolidated
Grant No. ST/J000469/1, “String theory, gauge theory and
duality.” The work of M. B. is partially supported by the
ERC Advanced Grant No. 226455, “Superfields
Automatic Gait Recognition
No full textGait is an emergent biometric aimed essentially to recognise people by the way they walk. Gait's advantages are that it is non-invasive, like automatic face recognition, and that it is less likely to be obscured than other biometrics. Gait has allied subjects including medical studies, psychology, human body modelling and motion tracking. These lend support to the view that gait has clear potential as a biometric. Essentially, we require to use computer vision techniques to derive a gait signature from a sequence of images. The majority of current approaches analyse an image sequence to derive motion characteristics which are then used for recognition; only one approach is feature based. Early results by these studies confirm that there is a rich potential in gait for recognition
Fluorescence-based methods to study rapid dynamics and conformational flexibility in peptides
Get PDFIntramolecular collision of polypeptides is the primary step in protein folding, the
dynamics of which is of importance for understanding this fascinating topic. In this thesis
the rapid dynamics and flexibility of several sets of peptides were experimentally
investigated with a fluorescence-based method, where the long-lived, hydrophilic
fluorophore, 2,3-diazabicyclo[2.2.2]oct-2-ene (DBO), was employed, which can be
selectively and efficiently quenched by tryptophan (Trp) through contact. An asparagine
derivative, Fmoc-DBO, was synthesized and applied to standard solid-phase peptide
synthesis to obtain DBO/Trp-labeled peptides. The end-to-end collision rates can then be
directly related to the intramolecular quenching of DBO by Trp. [Hudgins, R. R.; Huang,
F.; Gramlich, G.; Nau, W. M. J. Am. Chem. Soc. 2002, 124, 556-564 (Appendix I); Nau,
W. M.; Huang, F.; Wang, X.; Bakirci, H.; Gramlich, G.; Marquez, C. Chimia 2003, 57,
161-167 (Appendix III); Marquez, C.; Huang, F.; Nau, W. M. IEEE Trans. Nanobiosci.
2004, 3, 39-45 (Appendix V)]
This method has been further improved by establishing a dual quencher system, i.e.,
tyrosine (Tyr) was employed as an additional quencher, which can react with DBO upon
contact but with a lower efficiency than Trp. The combination of two probe/quencher
pairs with different quenching efficiency as well as the theoretical results for
intermolecular diffusion allows the extrapolation of the microscopic rate constants for
formation and dissociation of the end-to-end encounter complex even in the absence of
diffusion-controlled quenching. [Nau, W. M.; Huang, F.; Wang, X.; Bakirci, H.;
Gramlich, G.; Marquez, C. Chimia 2003, 57, 161-167 (Appendix III); Huang, F.; Hudgins,
R. R.; Nau, W. M. 2004, Submitted for publication (Appendix VI)]
We first applied this fluorescence-based method to measure the end-to-end collision
rate constants in flexible Gly-Ser peptides with varying length. The results suggest that the
behavior of real peptides deviates significantly from that of the ideal chain model and the
speed limit for protein folding should be faster than that reported previously. [Hudgins, R.
R.; Huang, F.; Gramlich, G.; Nau, W. M. J. Am. Chem. Soc. 2002, 124, 556-564
(Appendix I)]
We also investigated the end-to-end collision rates of another series of peptides
composed of different types of amino acids in the backbone but with identical length. The
experimental results have led to a conformational flexibility scale for amino acids in peptides and suggested that the flexibility of peptides is mainly determined by the atoms
and groups in close proximity to the backbone, while the more remote atoms and groups
have a smaller effect on the peptide dynamics due to their larger conformational space.
[Huang, F.; Nau, W. M. Angew. Chem. Int. Ed. 2003, 42, 2269-2272 (Appendix II);
Huang, F.; Nau, W. M. Res. Chem. Intermed. 2004, submitted for publication (Appendix
VII)]
Further investigations on peptides derived from the N-terminal b-hairpin of
ubiquitin were also carried out. The end-to-end collision rates in these peptides showed
significant dependence on the secondary structure, i.e., the turn segment is much more
flexible than the strand segments, which supports a previous proposal that the b-turn is the
initiator for the formation of the whole b-hairpin. Activation energies for end-to-end
collision of these peptides showed a good agreement with the collision rate constants,
which indicates that the activation energy may also be a measure of the flexibility of
peptides although it is not as sensitive as the collision rate. [Huang, F.; Hudgins, R. R.;
Nau, W. M. 2004, Submitted for publication (Appendix VI)]
Additionally, to get more detailed structural information of our peptides and to
reveal the underlying reasons for the deviation of the experimental length dependence of
end-to-end collision rates from the theoretical prediction, intramolecular fluorescence
resonance energy transfer (FRET) was applied as an independent approach to investigate
the dynamics in peptide chains. Two energy donor/acceptor pairs with small Förster
critical radius, where either naphthalene or Trp serves as energy donor and DBO as energy
acceptor, were employed. Energy transfer between naphthalene and DBO was first
investigated at a very short distance, where DBO and naphthalene were separated by
dimethylsiloxy. It was found that the Dexter mechanism might dominate in this system
due to the close proximity of donor and acceptor, the high flexibility of the tether, and the
nonviscous solvent employed. [Pischel, U.; Huang, F.; Nau, W. M. Photochem. Photobiol.
Sci. 2004, 3, 305-310 (Appendix IV)] However, when naphthalene and DBO were
covalently attached to the opposite ends of peptides and studied in water, control
experiments in the presence of cucurbit[7]uril as an encapsulating host suggested that
FRET was the dominant mechanism, which allowed us to apply the FRET technique to
recover the intramolecular end-to-end distance distribution and diffusion coefficient by
means of global analysis. In the investigation with naphthalene/DBO energy donor/acceptor pair, slower diffusion coefficients in shorter chains were found for the
series of flexible Gly-Ser peptides, suggesting that shorter chains may exhibit a larger
internal friction limiting the conformational change. Additionally, the intramolecular
energy transfer efficiency have been measured with the Trp/DBO pair and the effective
average end-to-end distances were calculated, which provided a lower limit for the mean
end-to-end distance of peptides for the global data analysis and offered a complementary
approach to interpret the end-to-end collision rates determined with the same pair but
based on a collision-induced quenching mechanism. [Huang, F.; Wang, X.; Haas, E.; Nau,
W. M. 2004, In preparation (Appendix VIII)]
The fluorescence-based method based on contact quenching mechanism has some
other potential applications. It has potential to be applied for high-throughput screening of
protease activity and to investigate the helix-coil transition in peptides
Role of protein kinase C in phosphorylation of vinculin in adriamycin-resistant HL-60 leukemia cells
No full textIn response to phorbol esters such as 12-O-tetradecanoylphorbol-13-acetate (TPA), HL-60 cells differentiate to macrophage-like cells and exhibit the ability to phosphorylate vinculin in vitro. Adriamycin-resistant HL-60 (HL-60/ADR) cells similarly demonstrate this characteristic without prior treatment with TPA. Since protein kinase C (PK-C) is a cellular TPA receptor, we have examined the role of this enzyme in the inherent ability of HL-60/ADR cells to phosphorylate vinculin. DEAE-cellulose chromatography of cell extracts revealed that HL-60/ADR cells contained 2-fold more PK-C than did the parental cell line. All PK-C activity was found in the cytosol of wild type HL-60 cells, whereas 85% of PK-C activity was cytosolic and 15% was membrane-bound in HL-60/ADR cells. After a 2-day treatment with 10 nM TPA, PK-C activity was reduced 80-90% in both cell lines regardless of its intracellular distribution. Immunoblotting of cell extracts from HL-60/ADR cells or HL-60 cells following treatment with TPA revealed increased levels of a 52-kDa species of similar mass to M-kinase. Coincident with these changes after TPA treatment was a reduction in Ca2+ and phospholipid-independent phosphorylation of vinculin in vitro in extracts from HL-60/ADR cells, whereas HL-60 cells exhibited an elevation of this phosphoprotein. The phosphorylation of vinculin in TPA-treated HL-60 cells or untreated HL-60/ADR cells was blocked by antibodies to protein kinase C. These results suggest that it is not the absolute level of protein kinase C but rather the proteolytic activation of PK-C to a Ca2+ and phospholipid-independent form which is associated with the utilization of vinculin as an endogenous substrate
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