Epitope-targeted peptide inhibitors of Myc-Max Dimerization

Myc is a popular transcription factor that is found in about 30% of human cancers. Along with being present in many cancers, it is also a potent oncogenic driver. Myc dimerizes with Max in order to promote transcription of genes that are associated with cellular proliferation, differentiation, and survival. In cancers that are Myc-driven, the Myc concentrations are higher than in healthy cells. Developing drugs in which impede Myc-Max dimerization has been difficult because there are many interactions that occur over large interfaces. This project hypothesizes that using molecular peptide ligands that adsorb to Myc at the Myc-Max dimer interface will disrupt the intermolecular interactions between Myc-Max. Molecular screening is used to identify cyclic peptide ligands that will have a high binding affinity to epitopes on Myc. By using the peptide ligands, they can be tested to measure their affinity to the Mac protein, the location of the binding on Myc, and its ability to inhibit the formation of the dimer by Myc-Max. By having this data, it then can be used to engineer peptides that are potent inhibitors of Myc-Max dimerization

The dust properties and physical conditions of the interstellar medium in the LMC massive star forming complex N11

We combine Spitzer and Herschel data of the star-forming region N11 in the Large Magellanic Cloud to produce detailed maps of the dust properties in the complex and study their variations with the ISM conditions. We also compare APEX/LABOCA 870um observations with our model predictions in order to decompose the 870um emission into dust and non-dust (free-free emission and CO(3-2) line) contributions. We find that in N11, the 870um can be fully accounted for by these 3 components. The dust surface density map of N11 is combined with HI and CO observations to study local variations in the gas-to-dust mass ratios. Our analysis leads to values lower than those expected from the LMC low-metallicity as well as to a decrease of the gas-to-dust mass ratio with the dust surface density. We explore potential hypotheses that could explain the low observed gas-to-dust mass ratios (variations in the XCO factor, presence of CO-dark gas or of optically thick HI or variations in the dust abundance in the dense regions). We finally decompose the local SEDs using a Principal Component Analysis (i.e. with no a priori assumption on the dust composition in the complex). Our results lead to a promising decomposition of the local SEDs in various dust components (hot, warm, cold) coherent with that expected for the region. Further analysis on a larger sample of galaxies will follow in order to understand how unique this decomposition is or how it evolves from one environment to another.Comment: 24 pages, 16 figures, accepted for publication in MNRA

Care provision: An experimental investigation

In many principal-agent settings, the effort provided by the agent benefits a third party. In these settings, the quality of the work is determined, at least in part, by pro-social motivations. We present lab experiments that utilize a new three-player trust game to examine one such setting, care provision. Players include a principal, an agent, and a needy recipient. The principal can transfer resources to an agent, who then can transfer resources to the needy recipient; the latter transfers are tripled. As in the two-player version, we find high, but variable, levels of trust and reciprocity (agent transfers to target) in the baseline game. Two treatments allow us to gauge the impact of potential policy interventions to enhance care of the target recipient. The first provides a budget subsidy to the principle, and the second alters the effectiveness (multiplier) of the agent’s transfers. Results show that the behavior of the agent does not vary by treatment, and is determined primarily by the amount received from the principal. Principals, on the other hand, do respond to the policy changes. While budget subsidies increase the expenditure of the principal only slightly, policies impacting the agent’s efficiency increase the amount entrusted to them by principals and significantly impact the well-being of the recipient. Results suggest that policies that increase the effectiveness of care workers (the agents) may significantly impact the quality of work provided. Examples of such policies include increased worker training and reductions in red tape

Local-density approximation for exchange energy functional in excited-state density functional theory

An exchange energy functional is proposed and tested for obtaining a class of excited-state energies using density functional formalism. The functional is the excited-state counterpart of the local-density approximation functional for the ground state. It takes care of the state dependence of the energy functional and leads to highly accurate excitation energies

Similaridade genética entre açaizeiros (Euterpe oleracea Mart.) procedentes de Breves, Pará, Brasil baseada em marcadores RAPD.

Caracterizou-se a similaridade genética entre açaizeiros procedentes de Breves, Pará, Brasil por meio de marcadores RAPD. Amostras de folíolos de 25 indivíduos foram coletadas para a extração de DNA genômico e aplicação 22 primers. Os produtos foram separados em eletroforese horizontal e as imagens capturadas para análise. Foram amplificadas 107 bandas polimórficas. A similaridade genética média foi de 64% e possibilitou a separação de três grupos. Logo, açaizeiros procedentes desse local, mesmo sob a ação antrópica para palmito e frutos, apresentam pouca similaridade genética

Magnetic Instabilities and Phase Diagram of the Double-Exchange Model in Infinite Dimensions

Dynamical mean-field theory is used to study the magnetic instabilities and phase diagram of the double-exchange (DE) model with Hund's coupling J_H >0 in infinite dimensions. In addition to ferromagnetic (FM) and antiferromagnetic (AF) phases, the DE model supports a broad class of short-range ordered (SRO) states with extensive entropy and short-range magnetic order. For any site on the Bethe lattice, the correlation parameter q of a SRO state is given by the average q=, where theta_i is the angle between any spin and its neighbors. Unlike the FM (q=0) and AF (q=1) transitions, the transition temperature of a SRO state (T_{SRO}) with 0<q<1 cannot be obtained from the magnetic susceptibility. But a solution of the coupled Green's functions in the weak-coupling limit indicates that a SRO state always has a higher transition temperature than the AF for all fillings p<1 and even than the FM for 0.26\le p \le 0.39. For 0.39<p<0.73, where both the FM and AF phases are unstable for small J_H, a SRO phase has a non-zero T_{SRO} except close to p=0.5. As J_H increases, T_{SRO} eventually vanishes and the FM dominates. For small J_H, the T=0 phase diagram is greatly simplified by the presence of the SRO phase. A SRO phase is found to have lower energy than either the FM or AF phases for 0.26\le p0 but appears for J_H\neq 0. For p near 1, PS occurs between an AF with p=1 and either a SRO or a FM phase. The stability of a SRO state at T=0 can be understood by examining the interacting DOS,which is gapped for any nonzero J_H in an AF but only when J_H exceeds a critical value in a SRO state.Comment: 38 pages, 11 figures, submitted to New Journal of Physic