Spin and Orbital Angular Momentum Distribution Functions of the Nucleon

A theoretical prediction is given for the spin and orbital angular momentum distribution functions of the nucleon within the framework of an effective quark model of QCD, i.e. the chiral quark soliton model. An outstanding feature of the model is that it predicts fairly small quark spin fraction of the nucleon $\Delta \Sigma \simeq 0.35$, which in turn dictates that the remaining 65% of the nucleon spin is carried by the orbital angular momentum of quarks and antiquarks at the model energy scale of $Q^2 \simeq 0.3 {GeV}^2$. This large orbital angular momentum necessarily affects the scenario of scale dependence of the nucleon spin contents in a drastic way.Comment: 16 pages, latex, 3 eps figures, the revised version to appear in Physical Review

Chorale Topic from Haydn to Brahms: Chorale in Secular Contexts of the Eighteenth and Nineteenth Centuries

Chorale as a genre originated in sixteenth-century Lutheran worship music, but chorales and chorale style did not really enter the vocabulary of secular concert music as a musical topic until the eighteenth century, as a semiotic code for ideas and feelings associated with chorales. Although the frequency of use as well as the range of contexts and implied meanings of chorale topic increased from the eighteenth to the nineteenth centuries, the scholarship of topical analysis concerning chorales has been vague and incomplete. Chorales by definition are congregational, identifying and expressing the sentiments of a group, and their most common associations are of purity, archaism, and of course spirituality. When chorales are used topically, the range of their expressive perspectives broadens considerably, and varies widely depending on the context. Chorale topic can express a religious or nationalistic “We,” a monumental and impersonal “It,” or an intimate and personal “I.” Within the category of “I” expressions, chorale topic can express the irony and despair of the “I” separated from the “We,” or on the other hand, the comfort, guidance, or transcendence of the separated “I” seeking and finding its community or communion. Haydn was one of the first composers to regularly use chorale as a topic in slow movements of his symphonies and string quartets. Nineteenth century composers—Beethoven, Schubert, Meyerbeer, Mendelssohn, Chopin, Schumann, and Brahms among others—provide examples of chorale topic of every expressive type and in many genres, including art song, oratorio, piano sonata, duo sonata, string quartet, symphony, opera, and piano nocturne. Because of their resonance with actual religious practice, chorales and chorale topic remain perennially current, inherently accessible, and easily blended with other styles and topics. Understanding the range of meanings that chorale topic can carry is thus essential to a solid stylistic understanding and hermeneutic competence with music of the eighteenth and nineteenth centuries

Regulators of Rho GTPases in neuronal development

The formation and elaboration of axonal and dendritic morphologies are fundamental aspects of neuronal polarization critical for information processing. In general, developing CNS neurons elaborate one axon and multiple dendrites in response to intracellular and extracellular cues, so as to transmit and receive information, respectively. The molecular mechanisms underlying axon-dendrite polarity are complex and involve the integration of numerous signaling pathways that impinge on the cytoskeleton. One group of proteins, the Rho GTPases, has emerged as key integrators of environmental cues to regulate the underlying axonal and dendritic cytoskeletons. Here, we discuss the role of regulators of the Rac1 GTPase in axon development and highlight the importance of both actin and microtubule remodeling in this process

Estimation of Organ Biodistribution of Activities in Human from External Measurement with TLD

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