Dynamic Interrelation of Births and Deaths: Evidence from Plant Level Data

In this paper, the dynamic panel data method is used to investigate the dynamic interrelation of plant births and plant deaths. The dynamic panel data method considers the endogenous problem and individual effects. Empirical findings support the multiplier effect. In addition, exit does not cause entry, whereas entry causes exit.

Superradiant phase transition induced by the indirect Rabi interaction

We theoretically study the superradiant phase transition (SPT) in an indirect Rabi model, where both a two-level system and a single mode bosonic field couple to an auxiliary bosonic field. We find that the indirect spin-field coupling induced by the virtual excitation of the auxiliary field can allow the occurrence of a SPT at a critical point, and the influence of the so-called $A^2$ term in the normal Rabi model is naturally avoided. In the large detuning regime, we present the analytical expression of quantum critical point in terms of the original system parameters. The critical atom-field coupling strength is tunable, which will loosen the conditions on realizing the SPT. Considering a hybrid magnon-cavity-qubit system, we predict the squeezed cat state of magnon generated with feasible experimental parameters, which has potential applications in quantum metrology and quantum information processing.Comment: 12 pages, 8 figure

Relativistic Correction to J/\psi Production at Hadron Colliders

Relativistic corrections to the color-singlet J/\psi hadroproduction at the Tevatron and LHC are calculated up to O(v^2) in nonrelativistic QCD (NRQCD). The short distance coefficients are obtained by matching full QCD with NRQCD results for the subprocess g+g\to J/\psi+g. The long distance matrix elements are extracted from observed J/\psi hadronic and leptonic decay widths up to O}(v^2). Using the CTEQ6 parton distribution functions, we calculate the LO production cross sections and relativistic corrections for the process p+\bar{p}(p)\to J/\psi+X at the Tevatron and LHC. We find that the enhancement of O(v^2) relativistic corrections to the cross sections over a wide range of large transverse momentum p_t is negligible, only at a level of about 1 %. This tiny effect is due to the smallness of the correction to short distance coefficients and the suppression from long distance matrix elements. These results indicate that relativistic corrections can not help to resolve the large discrepancy between leading order prediction and experimental data for J/\psi production at the Tevatron.Comment: 9 pages, 5 figure

Hedonic Values And Utilitarian Values As Predicators Of Social Media Participation

This research proposes a model to investigate the behavior of posting articles and the continued use of social media via Babin’s value perspective. The antecedents of values are web quality and users’ emotions. The model was tested with PLS-Graph software based on its structural equation modeling approach. Data was gained from 310 users. The results revealed that antecedents have a strong impact on user values, which in turn influences users’ intention to post articles and continue to use social media. Several implications for research and practice have been derived from these findings

Phylogenetic analysis and classification of the Brassica rapa SET-domain protein family

<p>Abstract</p> <p>Background</p> <p>The SET (<it>Su(var)3-9, Enhancer-of-zeste, Trithorax</it>) domain is an evolutionarily conserved sequence of approximately 130-150 amino acids, and constitutes the catalytic site of lysine methyltransferases (KMTs). KMTs perform many crucial biological functions <it>via </it>histone methylation of chromatin. Histone methylation marks are interpreted differently depending on the histone type (i.e. H3 or H4), the lysine position (e.g. H3K4, H3K9, H3K27, H3K36 or H4K20) and the number of added methyl groups (i.e. me1, me2 or me3). For example, H3K4me3 and H3K36me3 are associated with transcriptional activation, but H3K9me2 and H3K27me3 are associated with gene silencing. The substrate specificity and activity of KMTs are determined by sequences within the SET domain and other regions of the protein.</p> <p>Results</p> <p>Here we identified 49 SET-domain proteins from the recently sequenced <it>Brassica rapa </it>genome. We performed sequence similarity and protein domain organization analysis of these proteins, along with the SET-domain proteins from the dicot <it>Arabidopsis thaliana</it>, the monocots <it>Oryza sativa </it>and <it>Brachypodium distachyon</it>, and the green alga <it>Ostreococcus tauri. </it>We showed that plant SET-domain proteins can be grouped into 6 distinct classes, namely KMT1, KMT2, KMT3, KMT6, KMT7 and S-ET. Apart from the S-ET class, which has an interrupted SET domain and may be involved in methylation of nonhistone proteins, the other classes have characteristics of histone methyltransferases exhibiting different substrate specificities: KMT1 for H3K9, KMT2 for H3K4, KMT3 for H3K36, KMT6 for H3K27 and KMT7 also for H3K4. We also propose a coherent and rational nomenclature for plant SET-domain proteins. Comparisons of sequence similarity and synteny of <it>B. rapa </it>and <it>A. thaliana </it>SET-domain proteins revealed recent gene duplication events for some KMTs.</p> <p>Conclusion</p> <p>This study provides the first characterization of the SET-domain KMT proteins of <it>B. rapa</it>. Phylogenetic analysis data allowed the development of a coherent and rational nomenclature of this important family of proteins in plants, as in animals. The results obtained in this study will provide a base for nomenclature of KMTs in other plant species and facilitate the functional characterization of these important epigenetic regulatory genes in <it>Brassica </it>crops.</p

Pharmacokinetics, safety and tolerability of L-3-n-butylphthalide tablet after single and multiple oral administrations in healthy Chinese volunteers

L-3-n-butylphthalide (L-NBP) is a naturally occurring antioxidant, which can be used for the treatment of acute ischemic stroke and vascular dementia. This study evaluated the safety, tolerability and pharmacokinetics of L-NBP tablets in healthy Chinese volunteers. This was a single-center, randomized, double-blind, placebo-controlled, single- and multiple-dose study. Subjects were assigned to receive a single dose of L-NBP tablet at either 80, 160, 320, or 480 mg (n=40), or multiple doses of 160 mg twice daily for 7 days (n=12). Plasma samples were analyzed with LC-MS/MS. Pharmacokinetic parameters of L-NBP were calculated using non-compartmental analysis with WinNonlin software. Statistical analysis was performed using SPSS software. All adverse events (AEs) were mild and of limited duration; AEs in this study occurred less frequently and more mildly than AEs listed for the DL-NBP soft capsule. No serious adverse event (SAE), death or withdrawal from the study was observed. In the single-dose study, Cmax was reached at about 1 h, and the mean t1/2 was approximately 13.76 h. Area under curve (AUC) and Cmax increased with dose escalation, but dose proportionality was not observed over the range of 160 to 480 mg. In the multiple-dose study, the steady-state was reached within 3 days with slight accumulation. In summary, the L-NBP tablet was well tolerated in healthy Chinese subjects. Slight accumulation appeared after repeated doses.L-3-n-butilftalida (L-NMP) é um antioxidante natural, que pode ser utilizado para o tratamento do acidente isquêmico agudo e demência vascular. Este estudo avaliou segurança, tolerância e farmacocinética de comprimidos de L-NBP em chineses voluntários sadios. Este foi um estudo monocêntrico, randomizado, duplo cego, com controle por placebo e doses única e múltipla. Os indivíduos receberam dose única de comprimido de L-NBP de 80, 160, 320 ou 480 mg (n=40) e doses múltiplas de 160 mg duas vezes ao dia, por sete dias (n=12). Amostras de plasma foram analisadas com LC-MS/MS. Os parâmetros farmacocinéticos do L-NBP foram calculados utilizando análise não compartimental, com o programa WinNonlin. A análise estatística foi realizada utilizando-se o programa SPSS. Todos os eventos adversos (EAs) foram moderados e de duração limitada. EAs nesse estudo ocorreram menos frequentemente e mais moderadamente do que os EAs relacionados para cápsulas moles de DL-NBP. Não se observaram eventos adversos graves (EAG), morte ou abandono do estudo. Com dose única, atingiu-se o Cmax em cerca de 1 hora e o t1/2 médio foi de, aproximadamente, 13,76 h. A área sob a curva (ASC) e o Cmax aumentaram com o aumento da dose, mas não se observou proporcionalidade na faixa acima de 160 a 480 mg. No estudo de dose múltipla, o equilíbrio foi alcançado em três dias, com pequeno acúmulo. Em resumo, o comprimido de L-NMP foi bem tolerado em indivíduos chineses saudáveis. O acúmulo pequeno apareceu após doses repetidas