Effect of sunlight shielding on leaf structure and amino acids concentration of light sensitive albino tea plant

Light sensitive albino tea cultivar ‘Jinguang’ (Camellia sinensis) which grows albinism leaf in yellow colour, results to high level of amino acids but low levels of photosynthetic pigments including chlorophylls, neoxanthin, violaxanthin, phytoxanthin and β-carotene when it is exposed to high sunlight illumination in the summer season. In this case, the chloroplasts showed partially lysed, with few thylakoids. The leaf albinism was reverted when the leaf was shielded from direct illumination of strong sunlight. It is considered that the blocked development of chloroplast and photosynthetic pigments in the albinism leaf inhibited the biosynthesis of leaf proteins, resulting in an accumulation of free amino acids.Keywords: Camellia sinensis, leaf albinism, light intensity, photosynthetic pigments, amino acids, chloroplastAfrican Journal of Biotechnology Vol. 12(36), pp. 5535-553

Young driver distraction by text messaging: A comparison of the effects of reading and typing text messages in Chinese versus English

Background: Reading and typing text messages while driving seriously impairs driving performance and are prohibited activities in many jurisdictions. Hong Kong is a bilingual society and many people write in both Chinese and English. As the input methods for text messaging in Chinese and English are considerably different, this study used a driving simulator approach to compare the effects of reading and typing Chinese and English text messages on driving performance. Method: The driving performances of 26 participants were monitored under the following conditions: (1) no distraction, (2) reading and typing Chinese text messages, and (3) reading and typing English text messages. The following measures of driving performance were collected under all of the conditions: reaction time (RT), driving lane undulation (DLU), driving speed fluctuation (DSF), and car-following distance (CFD) between test and leading cars. Results: RT, DLU, and DSF were significantly impaired by reading and typing both Chinese and English text messages. Moreover, typing text messages distracted drivers more than reading them. Although the Chinese text messaging input system is more complicated than the English system, the use of Chinese did not cause a significantly different degree of distraction. Conclusion: Both reading and typing text messages while driving should be prohibited regardless of whether Chinese or English is used.postprin

Perspectiva longitudinal da relação entre coesão e rendimento desportivo no futebol profissional masculino

O objectivo deste estudo é apresentar os resultados de um estudo longitudinal (10 jogos) que explora a existência de correlações estatisticamente significativas entre as quatro dimensões da coesão operacionalizadas pelo Modelo Conceptual de Coesão (Carron, Brawley & Widmeyer, 1985) e diferentes medidas de rendimento desportivo. Os participantes são 23 atletas de uma equipa de futebol profissional (M idade = 22.64; DP idade = 3.89) e os 3 treinadores. Uma versão portuguesa (Martins, Almeida & Viana, no prelo) do Group Environment Questionnaire (Carron, Widmeyer & Brawley, 1985) e um questionário pós-competitivo de avaliação do rendimento, dirigido a treinadores e atletas (Cruz, 1996), foram usados como instrumentos. Os resultados indicam a existência de uma relação entre a Coesão e o Rendimento desportivo em sete dos dez jogos analisados. De forma algo surpreendente e contrariamente ao que seria expectável, verificaram-se correlações positivas e negativas entre a dimensão Integração no Grupo-Social e as diferentes medidas de rendimento. De igual modo, verificaram-se correlações negativas entre as dimensões da coesão com orientação para a tarefa e o rendimento da equipa, contrariando assim todas as evidências. Os resultados obtidos nesta investigação parecem apoiar a concepção de que, de facto, existe uma relação circular entre coesão e rendimento desportivo.ABSTRACT: The purpose of this study is to present the main results of a longitudinal study (10 games) which explores the existence of statistically significant correlations between the four dimensions of the cohesion considered by the Conceptual Model of Cohesion (Carron, Brawley & Widmeyer, 1985) and different measures of sportive performance. Participants are 23 athletes from a professional soccer team (M age = 22.64; SD age = 3.89) and the 3 coaches. A Portuguese version (Martins, Almeida & Viana, in press) of The Group Environment Questionnaire (Carron, Widmeyer & Brawley, 1985) and a post-competition questionnaire on performance assessment, intended for athletes and coaches (Cruz, 1996), were used as instruments. Regarding the objectives, the existence of a relation between Cohesion and Sport Performance was observed in seven of the ten games analysed. The results indicate the existence of positive and negative correlations between the IG-S and the different measures of performance, as well as negative correlations between the dimensions of the cohesion with guidance towards the task and the team’s performance, thus contradicting the results of previous investigations. The results obtained from this investigation appear to support the concept that there is in fact a circular relation between cohesion and sportive performance

Chimeric 14-3-3 proteins for unraveling interactions with intrinsically disordered partners

In eukaryotes, several "hub" proteins integrate signals from different interacting partners that bind through intrinsically disordered regions. The 14-3-3 protein hub, which plays wide-ranging roles in cellular processes, has been linked to numerous human disorders and is a promising target for therapeutic intervention. Partner proteins usually bind via insertion of a phosphopeptide into an amphipathic groove of 14-3-3. Structural plasticity in the groove generates promiscuity allowing accommodation of hundreds of different partners. So far, accurate structural information has been derived for only a few 14-3-3 complexes with phosphopeptide-containing proteins and a variety of complexes with short synthetic peptides. To further advance structural studies, here we propose a novel approach based on fusing 14-3-3 proteins with the target partner peptide sequences. Such chimeric proteins are easy to design, express, purify and crystallize. Peptide attachment to the C terminus of 14-3-3 via an optimal linker allows its phosphorylation by protein kinase A during bacterial co-expression and subsequent binding at the amphipathic groove. Crystal structures of 14-3-3 chimeras with three different peptides provide detailed structural information on peptide-14-3-3 interactions. This simple but powerful approach, employing chimeric proteins, can reinvigorate studies of 14-3-3/phosphoprotein assemblies, including those with challenging low-affinity partners, and may facilitate the design of novel biosensors

The controversy in the γγ→ρρ\gamma\gamma\to\rho\rho process: potential scattering or qqqˉqˉqq\bar{q}\bar{q} resonance ?

The $\gamma\gamma\to\rho^0\rho^0\to 4 \pi$ reaction shows a broad peak at 1.5 GeV in the $(J^P,J_z)=(2^+,2)$ channel which has no counterpart in the $\rho^+\rho^-$ channel. This "resonance" is considered as a candidate for a $qq\bar q\bar q$ state in the "s-channel". We show, however, that it can also be explained by potential scattering of $\rho^0\rho^0$ via the $\sigma$- exchange in the "t-channel".Comment: 12 pages, latex, 3 postscript figures, to appear in Zeitschrift fur Physi

A Formalization of The Natural Gradient Method for General Similarity Measures

In optimization, the natural gradient method is well-known for likelihood maximization. The method uses the Kullback-Leibler divergence, corresponding infinitesimally to the Fisher-Rao metric, which is pulled back to the parameter space of a family of probability distributions. This way, gradients with respect to the parameters respect the Fisher-Rao geometry of the space of distributions, which might differ vastly from the standard Euclidean geometry of the parameter space, often leading to faster convergence. However, when minimizing an arbitrary similarity measure between distributions, it is generally unclear which metric to use. We provide a general framework that, given a similarity measure, derives a metric for the natural gradient. We then discuss connections between the natural gradient method and multiple other optimization techniques in the literature. Finally, we provide computations of the formal natural gradient to show overlap with well-known cases and to compute natural gradients in novel frameworks

1H, 15N, and 13C chemical shift assignments of calcium-binding protein 1 with Ca2+ bound at EF1, EF3 and EF4

Calcium-binding protein 1 (CaBP1) regulates inositol 1,4,5-trisphosphate receptors (InsP3Rs) and a variety of voltage-gated Ca2+ channels in the brain. We report complete NMR chemical shift assignments of the Ca2+-saturated form of CaBP1 with Ca2+ bound at EF1, EF3 and EF4 (residues 1–167, BMRB no. 16862)

A very faint core-collapse supernova in M85

An anomalous transient in the early Hubble-type (S0) galaxy Messier 85 (M85) in the Virgo cluster was discovered by Kulkarni et al. (2007) on 7 January 2006 that had very low luminosity (peak absolute R-band magnitude MR of about -12) that was constant over more than 80 days, red colour and narrow spectral lines, which seem inconsistent with those observed in any known class of transient events. Kulkarni et al. (2007) suggest an exotic stellar merger as the possible origin. An alternative explanation is that the transient in M85 was a type II-plateau supernova of extremely low luminosity, exploding in a lenticular galaxy with residual star-forming activity. This intriguing transient might be the faintest supernova that has ever been discovered.Comment: 7 pages, 2 figures. Submitted to Nature "Brief Communication Arising" on 18 July 2007, Accepted on 17 August 2007. Arising from: Kulkarni et al. 2007, Nature, 447, 458-46

A spin triplet supercurrent through the half-metallic ferromagnet CrO2

In general, conventional superconductivity should not occur in a ferromagnet, though it has been seen in iron under pressure. Moreover, theory predicts that the current is always carried by pairs of electrons in a spin singlet state, so conventional superconductivity decays very rapidly when in contact with a ferromagnet, which normally prohibits the existence of singlet pairs. It has been predicted that this rapid spatial decay would not occur when spin triplet superconductivity could be induced in the ferromagnet. Here we report a Josephson supercurrent through the strong ferromagnet CrO2, from which we infer that it is a spin triplet supercurrent. Our experimental setup is different from those envisaged in the earlier predictions, but we conclude that the underlying physical explanation for our result is a conversion from spin singlet to spin triplets at the interface. The supercurrent can be switched with the direction of the magnetization, analogous to spin valve transistors, and therefore could enable magnetization-controlled Josephson junctions.Comment: 14 pages, including 3 figure