1,839 research outputs found
Technology Evaluation and Imitation: Do They Have Differential or Dichotomous Effects on ERP Adoption and Assimilation in China?
postprin
How do bidders’ organism reactions mediate auction stimuli and bidder loyalty in online auctions? The case of Taobao in China
© 2016 Elsevier B.V.Currently, it is critical to nurture bidder loyalty in the highly competitive online auction business. This study investigated the mediating effect of consumer perceptions between technological/brand stimuli and bidder loyalty to an online auction website by applying the traditional and evolutionary stimulus-organism-response models. We tested these models using 449 bidders from Taobao, an online auction service provider in China. Based on the results of covariance-based structural equation modelling, we showed that consumer perceptions fully mediate technological stimuli, but only partially mediate brand stimuli, and bidder loyalty. These results can be used to further improve the related research and practice.Link_to_subscribed_fulltex
Overexpression of ZFX confers self-renewal and chemoresistance properties in hepatocellular carcinoma
postprin
Use of elder donors for cadaveric single kidney transplantation: a new evolution or an inacceptable risk?
Jet coherence in QCD media: the antenna radiation spectrum
We study the radiation of a highly energetic partonic antenna in a colored
state traversing a dense QCD medium. Resumming multiple scatterings of all
involved constituents with the medium we derive the general gluon spectrum
which encompasses both longitudinal color coherence between scattering centers
in the medium, responsible for the well known Landau-Pomeranchuk-Migdal (LPM)
effect, and transverse color coherence between partons inside a jet, leading,
in vacuum, to angular ordering of the parton shower. We discuss shortly the
onset of transverse decoherence which is reached in opaque media. In this
regime, the spectrum consists of independent radiation off the antenna
constituents.Comment: 15 pages, 2 figures, paper shortened and partly rewritten, references
added, results unchange
Permian (Artinskian to Wuchapingian) conodont biostratigraphy in the Tieqiao section, Laibin area, South China
Permian strata from the Tieqiao section (Jiangnan Basin, South China) contain several distinctive conodont assemblages. Early Permian (Cisuralian) assemblages are dominated by the genera Sweetognathus, Pseudosweetognathus and Hindeodus with rare Neostreptognathodus and Gullodus. Gondolellids are absent until the end of the Kungurian stage—in contrast to many parts of the world where gondolellids and Neostreptognathodus are the dominant Kungurian conodonts. A conodont changeover is seen at Tieqiao and coincided with a rise of sea level in the late Kungurian to the early Roadian: the previously dominant sweetognathids were replaced by mesogondolellids. The Middle and Late Permian (Guadalupian and Lopingian Series) witnessed dominance of gondolellids (Jinogondolella and Clarkina), the common presence of Hindeodus and decimation of Sweetognathus. Twenty main and seven subordinate conodont zones are recognised at Tieqiao, spanning the lower Artinskian to the middle Wuchiapingian Stage. The main (first appearance datum) zones are, in ascending order by stage: the Sweetognathus (Sw.) whitei, Sw. toriyamai, and Sw. asymmetrica n. sp. Zones for the Artinskian; the Neostreptognathodus prayi, Sw. guizhouensis, Sw. iranicus, Sw. adjunctus, Sw. subsymmeticus and Sw. hanzhongensis Zones for the Kungurian; the Jinogondolella (J.) nankingensis Zone for the Roadian; the J. aserrata Zone for the Wordian; the J. postserrata, J. shannoni, J. altudaensis, J. prexuanhanensis, J. xuanhanensis, J. granti and Clarkina (C.) hongshuiensis Zones for the Capitanian and the C. postbitteri Zone and C. transcaucasica Zone for the base and middle of the Wuchiapingian. The subordinate (interval) zones are the Pseudosweetognathus (Ps.) costatus, Ps. monocornus, Hindeodus (H.) gulloides, Pseudohindeodus ramovsi, Gullodus (G.) sicilianus, G. duani and H. excavates Zones. In addition, three new species, Gullodus tieqiaoensis n. sp., Pseudohindeodus elliptica n. sp. and Sweetognathus asymmetrica n. sp. are described. Age assignments for less common species (e.g., G. duani, H. catalanoi and Pseudosweetognathus monocornus etc.) are reassessed based on a rich conodont collection
New Permian-Triassic conodont data from Selong (Tibet) and the youngest occurrence of Vjalovognathus
The controversial biostratigraphy of the well-known Permo-Triassic (P-T) boundary section at Selong, South Tibet is reinvestigated based on large conodont samples. The conodont data in this study confirm that the upper part of Selong Formation and the Waagenites Bed in the lower part of Kangshare Formation as Changshingian age. Just above the Waagenites Bed, the Otoceras latilobatum Bed is assigned to the basal Triassic due to the presence of H. parvus Zone. The discovery of Vjalovognathus (a cool-temperature tolerant form) in Changshingian strata allows the youngest Vjalovognathus species (V. carinatus sp. nov.) to be described, and a possible Permian Vjalovognathus evolutionary trend proposed: in ascending order this is, V. australis (late Sakmarian-early Artinskian), V. shindyensis (early Kungurian), V. nicolli (late Kugurian-Early Roadian) and ultimately V. carinatus sp. nov. (Changshingian). The last species V. carinatus sp. nov. is also found in the pre-mass extinction beds at Guryul Ravine, Kashmir allowing correlation with South Tibet
RARS2 mutations in a sibship with infantile spasms
Pontocerebellar hypoplasia is a group of heterogeneous neurodevelopmental disorders characterized by reduced volume of the brainstem and cerebellum. We report two male siblings who presented with early infantile clonic seizures, and then developed infantile spasms associated with prominent isolated cerebellar hypoplasia/atrophy on magnetic resonance imaging (MRI). Using whole exome sequencing techniques, both were found to be compound heterozygotes for one previously reported and one novel mutation in the gene encoding mitochondrial arginyl-tRNA synthetase 2 (RARS2). Mutations in this gene have been classically described in pontocerebellar hypoplasia type six (PCH6), a phenotype characterized by early (often intractable) seizures, profound developmental delay, and progressive pontocerebellar atrophy. The electroclinical spectrum of PCH6 is broad and includes a number of seizure types: myoclonic, generalized tonic-clonic, and focal clonic seizures. Our report expands the characterization of the PCH6 disease spectrum and presents infantile spasms as an associated electroclinical phenotype
Analysis of isoflavones and flavonoids in human urine by UHPLC
A rapid, ultra high-performance liquid chromatographic (UHPLC) method has been developed and validated for simultaneous identification and analysis of the isoflavones genistein, daidzein, glycitin, puerarin, and biochanin A, and the flavonoids (±)-catechin, (−)-epicatechin, rutin, hesperidin, neohesperidin, quercitrin, and hesperetin in human urine. Urine samples were incubated with β-glucuronidase/sulfatase. UHPLC was performed with a Hypersil Gold (50 × 2.1 mm, 1.9 μm) analytical column. Elution was with a gradient prepared from aqueous trifluoroacetic acid (0.05%) and acetonitrile. UV detection was performed at 254 and 280 nm. The calibration curves were indicative of good linearity (r2 ≥ 0.9992) in the range of interest for each analyte. LODs ranged between 15.4 and 107.0 ng mL−1 and 3.9 and 20.4 ng mL−1 for flavonoids and isoflavones, respectively. Intra-day and inter-day precision (C.V., %) was less than 3.9% and 3.8%, respectively, and accuracy was between 0.03% and 5.0%. Recovery was 70.35–96.58%. The method is very rapid, simple, and reliable, and suitable for pharmacokinetic analysis. It can be routinely used for simultaneous determination of these five isoflavones and seven flavonoids in human urine. The method can also be applied to studies after administration of pharmaceutical preparations containing isoflavones and flavonoids to humans
On the evolutionary origin of aging
It is generally believed that the first organisms did not age, and that aging thus evolved at some point in the history of life. When and why this transition occurred is a fundamental question in evolutionary biology. Recent reports of aging in bacteria suggest that aging predates the emergence of eukaryotes and originated in simple unicellular organisms. Here we use simple models to study why such organisms would evolve aging. These models show that the differentiation between an aging parent and a rejuvenated offspring readily evolves as a strategy to cope with damage that accumulates due to vital activities. We use measurements of the age-specific performance of individual bacteria to test the assumptions of the model, and find evidence that they are fulfilled. The mechanism that leads to aging is expected to operate in a wide range of organisms, suggesting that aging evolved early and repeatedly in the history of life. Aging might thus be a more fundamental aspect of cellular organisms than assumed so far
- …