Rethinking the Romans: New Views of Ancient Sculpture

Exhibition Notes, Number 13, 2001. This gallery guide has been created to accompany the exhibition Rethinking the Romans: New Views of Ancient Sculpture at the Museum of Art, Rhode Island School of Design (RISD). The installation presents RISD’s exceptional Roman sculpture collection in light of new scholarship, which stresses meaning, use, and context within Roman culture. Includes six short essays.https://digitalcommons.risd.edu/risdmuseum_journals/1028/thumbnail.jp

Deterministic ratchets: route to diffusive transport

The rectification efficiency of an underdamped ratchet operated in the adiabatic regime increases according to a scaling current-amplitude curve as the damping constant approaches a critical threshold; below threshold the rectified signal becomes extremely irregular and eventually its time average drops to zero. Periodic (locked) and diffusive (fully chaotic) trajectories coexist on fine tuning the amplitude of the input signal. The transition from regular to chaotic transport in noiseless ratchets is studied numerically.Comment: 9 pages, 5 figures, to be published in Phys. Rev.

Stokes' Drift of linear Defects

A linear defect, viz. an elastic string, diffusing on a planar substrate traversed by a travelling wave experiences a drag known as Stokes' drift. In the limit of an infinitely long string, such a mechanism is shown to be characterized by a sharp threshold that depends on the wave parameters, the string damping constant and the substrate temperature. Moreover, the onset of the Stokes' drift is signaled by an excess diffusion of the string center of mass, while the dispersion of the drifting string around its center of mass may grow anomalous.Comment: 14 pages, no figures, to be published in Phys.Rev.

A transcription factor network specifying inhibitory versus excitatory neurons in the dorsal spinal cord

The proper balance of excitatory and inhibitory neurons is crucial for normal processing of somatosensory information in the dorsal spinal cord. Two neural basic helix-loop-helix transcription factors (TFs), Ascl1 and Ptf1a, have contrasting functions in specifying these neurons. To understand how Ascl1 and Ptf1a function in this process, we identified their direct transcriptional targets genome-wide in the embryonic mouse neural tube using ChIP-Seq and RNA-Seq. We show that Ascl1 and Ptf1a directly regulate distinct homeodomain TFs that specify excitatory or inhibitory neuronal fates. In addition, Ascl1 directly regulates genes with roles in several steps of the neurogenic program, including Notch signaling, neuronal differentiation, axon guidance and synapse formation. By contrast, Ptf1a directly regulates genes encoding components of the neurotransmitter machinery in inhibitory neurons, and other later aspects of neural development distinct from those regulated by Ascl1. Moreover, Ptf1a represses the excitatory neuronal fate by directly repressing several targets of Ascl1. Ascl1 and Ptf1a bind sequences primarily enriched for a specific E-Box motif (CAGCTG) and for secondary motifs used by Sox, Rfx, Pou and homeodomain factors. Ptf1a also binds sequences uniquely enriched in the CAGATG E-box and in the binding motif for its co-factor Rbpj, providing two factors that influence the specificity of Ptf1a binding. The direct transcriptional targets identified for Ascl1 and Ptf1a provide a molecular understanding of how these DNA-binding proteins function in neuronal development, particularly as key regulators of homeodomain TFs required for neuronal subtype specification.National Institutes of Health grants: ([F31NS705592, R01 HD037932, R01 NS032817, F31 NS06144

Relationship of Internal Audit Functions to Governance of Local Government Units

The study determined the relationship between internal audit functions and governance in Local Government Units (LGUs) in Metro Manila, Philippines. The data were gathered from 510 employees of LGUs using stratified sampling. Majority ( 359 or 70.6%) of the respondents belonged to 31-50 years old; majority of them worked in finance (181 or 35.5%) and in social service provider department (179 or 35.1%) and were managers (44 or 8.6%), supervisors (188 or 36.9%), and in clerical position (278 or 54.5%). Results of the study revealed that the internal audit functions of the Internal Audit Units of the LGUs were very good. However, the respondents perceived that the internal audit units seldom retain an independent outlook in presenting their suggestions. The overall status of governance of LGUs included in the study was very good although they sometimes spend more than what they earned. Loans from private institutions are sometimes obtained. Further results revealed that all the dimensions of governance, i.e., financial management and reporting, delivery of basic services, legal compliance, and internal government were perceived very good but the respondents were most satisfied on financial management and reporting. There was a strong positive relationship of internal audit functions to governance. The findings showed that the predictors of governance included consulting services, assurance services, and age

Mediating Effect of Personality Traits on Religiosity and Ethical Leadership: Basis for a Leadership Development Program

The study aimed to determine the mediating effect of personality traits on religiosity and ethical leadership among administrators of Christian institutions in the Philippines. A self-constructed questionnaire was used in gathering the data from 265 administrators of Christian institutions in the Philippines. The study shows that the administrators are highly religious. As to their personality traits they are: highly open to experience; conscientious; extravert; agreeable; and moderately neurotic. As leaders, the administrators are highly ethical. Moreover the following have significant relationship to one another: religiosity and personality; religiosity and ethical leadership; and personality traits and ethical leadership. The predictors of the study are stewardship, prayer, and service. On the other hand, agreeableness, openness to experience, and conscientiousness predict ethical leadership. Furthermore, there is no impact to ethical leadership when gender, age and years of service are considered. But there is an association in ethical leadership and its dimensions between a bachelor’s degree holder and a master’s degree holder. Religiosity has no direct effect on ethical leadership. Personality traits fully mediate the relationship of religiosity and ethical leadership. Leadership development program was developed based on the results of the study

Noise-assisted classical adiabatic pumping in a symmetric periodic potential

We consider a classical overdamped Brownian particle moving in a symmetric periodic potential. We show that a net particle flow can be produced by adiabatically changing two external periodic potentials with a spatial and a temporal phase difference. The classical pumped current is found to be independent of the friction and to vanish both in the limit of low and high temperature. Below a critical temperature, adiabatic pumping appears to be more efficient than transport due to a constant external force.Comment: six pages, 3 figure

Momentum and Energy Distributions of Nucleons in Finite Nuclei due to Short-Range Correlations

The influence of short-range correlations on the momentum and energy distribution of nucleons in nuclei is evaluated assuming a realistic meson-exchange potential for the nucleon-nucleon interaction. Using the Green-function approach the calculations are performed directly for the finite nucleus $^{16}$O avoiding the local density approximation and its reference to studies of infinite nuclear matter. The nucleon-nucleon correlations induced by the short-range and tensor components of the interaction yield an enhancement of the momentum distribution at high momenta as compared to the Hartree-Fock description. These high-momentum components should be observed mainly in nucleon knockout reactions like $(e,e'p)$ leaving the final nucleus in a state of high excitation energy. Our analysis also demonstrates that non-negligible contributions to the momentum distribution should be found in partial waves which are unoccupied in the simple shell-model. The treatment of correlations beyond the Brueckner-Hartree-Fock approximation also yields an improvement for the calculated ground-state properties.Comment: 12 pages RevTeX, 7 figures postscript files appende

Width of the Δ\Delta resonance in nuclei

In this work we evaluate the imaginary part of the isobar $\Delta$ self-energy $\Sigma_{\Delta}$ from the two-body absorption process $\Delta+N\rightarrow 2N$. This contribution is calculated using a recently developed non-relativistic scheme, which allows for an evaluation of the self-energy with a basis of single-particle states appropriate for both bound hole states and for particle states in the continuum. In order to test the medium dependence of the self-energy, we calculate the two-body absorption term $\Sigma_{\Delta}^{A2}$ for several finite nuclei with $N=Z$, i.e.\ $^{16}$O, $^{40}$Ca and $^{100}$Sn. The resulting self-energy, which is energy dependent and non-local, is compared with a simple parameterization derived from nuclear matter.Comment: 5 pages 3 figures can be obtained from the authors, TU-93-160

Energy fluctuations in a biharmonically driven nonlinear system

We study the fluctuations of work done and dissipated heat of a Brownian particle in a symmetric double well system. The system is driven by two periodic input signals that rock the potential simultaneously. Confinement in one preferred well can be achieved by modulating the relative phase between the drives. We show that in the presence of pumping the stochastic resonance signal is enhanced when analyzed in terms of the average work done on the system per cycle. This is in contrast to the case when pumping is achieved by applying an external static bias, which degrades resonance. We analyze the nature of work and heat fluctuations and show that the steady state fluctuation theorem holds in this system.Comment: 13 pages, 14 figures, revised manuscrip