Guest Artist Series: Jessica Rivera, soprano and Kelley O\u27Connor, mezzo-soprano with Robert Spano, piano

KSU School of Music presents 2013-14 Guest Artist Series featuring Jessica Rivera, soprano and Kelley O\u27Connor, mezzo-soprano with Robert Spano, piano.https://digitalcommons.kennesaw.edu/musicprograms/1286/thumbnail.jp

Drastic effects of damping mechanisms on the third-order optical nonlinearity

We have investigated the optical response of superradiant atoms, which undergoes three different damping mechanisms: radiative dissipation ($\gamma_r$), dephasing ($\gamma_d$), and nonradiative dissipation ($\gamma_n$). Whereas the roles of $\gamma_d$ and $\gamma_n$ are equivalent in the linear susceptibility, the third-order nonlinear susceptibility drastically depends on the ratio of $\gamma_d$ and $\gamma_n$: When $\gamma_d \ll \gamma_n$, the third-order susceptibility is essentially that of a single atom. Contrarily, in the opposite case of $\gamma_d \gg \gamma_n$, the third-order susceptibility suffers the size-enhancement effect and becomes proportional to the system size.Comment: 5pages, 2figure

Ab initio calculations of structural and electronic properties of CdTe clusters

We present results of a study of small stoichiometric $Cd_{n}Te_{n}$ ($1{\leq}n{\leq}6$) clusters and few medium sized non-stoichiometric $Cd_{m}Te_{n}$ [($m,n= 13, 16, 19$); ($m{\neq}n$)] clusters using the Density Functional formalism and projector augmented wave method within the generalized gradient approximation. Structural properties {\it viz.} geometry, bond length, symmetry and electronic properties like HOMO-LUMO gap, binding energy, ionization potential and nature of bonding {\it etc.} have been analyzed. Medium sized non-stoichiometric clusters were considered as fragments of the bulk with T{$_{d}$} symmetry. It was observed that upon relaxation, the symmetry changes for the Cd rich clusters whereas the Te rich clusters retain their symmetry. The Cd rich clusters develop a HOMO-LUMO gap due to relaxation whereas there is no change in the HOMO-LUMO gap of the Te rich clusters. Thus, the symmetry of a cluster seems to be an important factor in determining the HOMO-LUMO gap.Comment: 8 pages 16 figure

Is experience the best teacher? Knowledge, perceptions, and awareness of wildfire risk

Wildfires represent a natural phenomenon with detrimental effects on natural resources and human health. A better knowledge, perception, and awareness of wildfire risk may help communities at risk of exposure to prevent future events and safeguard their own lives. The aim of this study is to explore differences between individuals with and without previous wildfire experience, in terms of (1) subjective and advanced wildfire knowledge, (2) self-reported perceptions, (3) level of information, (4) self-protection measures, and (5) importance of community involvement. As a second step, we investigated differences in the same variables, focusing more deeply on a group of individuals with previous wildfire experience, classifying them according to fire-related employment (fire-related workers vs. non-workers) and wildland–urban interface (WUI) proximity (WUI residents vs. non-WUI residents). The Kruskal–Wallis test was applied to establish differences between the pairs of subsamples. Our results partially confirmed our hypothesis, that direct experience leads individuals to have a greater preparedness on the topic of wildfires. Perception of knowledge is reflected only at a shallow level of expertise, and, therefore, no relevant within-group differences related to fire-related employment or to WUI proximity were detected. Moreover, available information was perceived to be insufficient, thus we report a strong need for developing effective communication to high-risk groups, such as homeowners and fire-related workers

Синдром «профессионального выгорания» у специалистов по социальной работе

В статті досліджується сутність та основні ознаки синдрому «професійного вигорання» у соціальних працівників.In the article the nature and main signs of «the professional burnout» syndrome of the social workers have been explored.В статье исследуется сущность и основные признаки синдрома «профессионального выгорания» у социальных работников

Targeted acetylation of NF-kappaB/RelA and histones by epigenetic drugs reduces post-ischemic brain injury in mice with an extended therapeutic window.

Nuclear factor-kappaB (NF-κB) p50/RelA is a key molecule with a dual effect in the progression of ischemic stroke. In harmful ischemia, but not in preconditioning insult, neurotoxic activation of p50/RelA is characterized by RelA-specific acetylation at Lys310 (K310) and deacetylation at other Lys residues. The derangement of RelA acetylation is associated with activation of Bim promoter. Objective: With the aim of producing neuroprotection by correcting altered acetylation of RelA in brain ischemia, we combined the pharmacological inhibition of histone deacetylase (HDAC) 1-3, the enzymes known to reduce global RelA acetylation, and the activation of sirtuin 1, endowed with a specific deacetylase activity on the K310 residue of RelA. To afford this aim, we tested the clinically used HDAC 1-3 inhibitor entinostat (MS-275) and the sirtuin 1 activator resveratrol. Methods: We used the mouse model of transient middle cerebral artery occlusion (MCAO) and primary cortical neurons exposed to oxygen glucose deprivation (OGD). Results: The combined use of MS-275 and resveratrol, by restoring normal RelA acetylation, elicited a synergistic neuroprotection in neurons exposed to OGD. This effect correlated with MS-275 capability to increase total RelA acetylation and resveratrol capability to reduce RelA K310 acetylation through the activation of an AMP-activated protein kinase-sirtuin 1 pathway. The synergistic treatment reproduced the acetylation state of RelA peculiar of preconditioning ischemia. Neurons exposed to the combined drugs totally recovered the optimal histone H3 acetylation.Neuroprotection was reproduced in mice subjected to MCAO and treated with MS-275 (20μg/kg and 200μg/kg) or resveratrol (6800μg/kg) individually. However, the administration of lowest doses of MS-275 (2μg/kg) and resveratrol (68μg/kg) synergistically reduced infarct volume and neurological deficits. Importantly, the treatment was effective even when administered 7h after the stroke onset. Chromatin immunoprecipitation analysis of cortices harvested from treated mice showed that the RelA binding and histone acetylation increased at the Bcl-x L promoter and decreased at the Bim promoter. Conclusion: Our study reveals that epigenetic therapy shaping acetylation of both RelA and histones may be a promising strategy to limit post-ischemic injury with an extended therapeutic window

A 3D Platform to Investigate Dynamic Cell-to-Cell Interactions Between Tumor Cells and Mesenchymal Progenitors

We here investigated the dynamic cell-to-cell interactions between tumor and mesenchymal stromal/stem cells (MSCs) by the novel VITVOⓇ 3D bioreactor that was customized to develop in vivo-like metastatic nodules of Ewing’s sarcoma (ES). MSCs are known to contribute to tumor microenvironment as cancer associated fibroblast (CAF) precursors and, for this reason, they have also been used as anti-cancer tools. Using dynamic conditions, the process of tissue colonization and formation of metastatic niches was recreated through tumor cell migration aiming to mimic ES development in patients. ES is an aggressive tumor representing the second most common malignant bone cancer in children and young adults. An urgent and unmet need exists for the development of novel treatment strategies to improve the outcomes of metastatic ES. The tumor-tropic ability of MSCs offers an alternative approach, in which these cells can be used as vehicles for the delivery of antitumor molecules, such as the proapoptotic TNF-related apoptosis inducing ligand (TRAIL). However, the therapeutic targeting of metastases remains challenging and the interaction occurring between tumor cells and MSCs has not yet been deeply investigated. Setting up in vitro and in vivo models to study this interaction is a prerequisite for novel approaches where MSCs affinity for tumor is optimized to ultimately increase their therapeutic efficacy. Here, VITVOⓇ integrating a customized scaffold with an increased inter-fiber distance (VITVO50) was used to develop a dynamic model where MSCs and tumor nodules were evaluated under flow conditions. Colonization and interaction between cell populations were explored by droplet digital PCR (ddPCR). VITVO50 findings were then applied in vivo. An ES metastatic model was established in NSG mice and biodistribution of TRAIL-expressing MSCs in mice organs affected by metastases was investigated using a 4-plex ddPCR assay. VITVOⓇ proved to be an easy handling and versatile bioreactor to develop in vivo-like tumor nodules and investigate dynamic cell-to-cell interactions with MSCs. The proposed fluidic system promises to facilitate the understanding of tumor-stroma interaction for the development of novel tumor targeting strategies, simplifying the analysis of in vivo data, and ultimately accelerating the progress towards the early clinical phase

Excitonic Strings in one dimensional organic compounds

Important questions concern the existence of excitonic strings in organic compounds and their signatures in the photophysics of these systems. A model in terms of Hard Core Bosons is proposed to study this problem in one dimension. Mainly the cases with two and three particles are studied for finite and infinite lattices, where analytical results are accessible. It is shown that if bi-excitonic states exist, three-excitonic and even, n-excitonic strings, at least in a certain range of parameters, will exist. Moreover, the behaviour of the transitions from one exciton to the biexciton is fully clarified. The results are in agreement with exact finite cluster diagonalizations of several model Hamiltonians.Comment: 36 pages, 4 eps figs. to appear in Phys. Rev.

Accelerating legacy applications with spatial computing devices

Heterogeneous computing is the major driving factor in designing new energy-efficient high-performance computing systems. Despite the broad adoption of GPUs and other specialized architectures, the interest in spatial architectures like field-programmable gate arrays (FPGAs) has grown. While combining high performance, low power consumption and high adaptability constitute an advantage, these devices still suffer from a weak software ecosystem, which forces application developers to use tools requiring deep knowledge of the underlying system, often leaving legacy code (e.g., Fortran applications) unsupported. By realizing this, we describe a methodology for porting Fortran (legacy) code on modern FPGA architectures, with the target of preserving performance/power ratios. Aimed as an experience report, we considered an industrial computational fluid dynamics application to demonstrate that our methodology produces synthesizable OpenCL codes targeting Intel Arria10 and Stratix10 devices. Although performance gain is not far beyond that of the original CPU code (we obtained a relative speedup of x 0.59 and x 0.63, respectively, for a single optimized main kernel, while only on the Stratix10 we achieved x 2.56 by replicating the main optimized kernel 4 times), our results are quite encouraging to drawn the path for further investigations. This paper also reports some major criticalities in porting Fortran code on FPGA architectures

Complete eigenstates of identical qubits arranged in regular polygons

We calculate the energy eigenvalues and eigenstates corresponding to coherent single and multiple excitations of an array of N identical qubits or two-level atoms (TLA's) arranged on the vertices of a regular polygon. We assume only that the coupling occurs via an exchange interaction which depends on the separation between the qubits. We include the interactions between all pairs of qubits, and our results are valid for arbitrary distances relative to the radiation wavelength. To illustrate the usefulness of these states, we plot the distance dependence of the decay rates of the n=2 (biexciton) eigenstates of an array of 4 qubits, and tabulate the biexciton eigenvalues and eigenstates, and absorption frequencies, line widths, and relative intensities for polygons consisting of N=2,...,9 qubits in the long-wavelength limit.Comment: Added a figure showing how these results can be used to compute deviations from "equal collective decoherence" approximation