Anemia in experimental protein deficiency in the rhesus monkey with special reference to iron metabolism

1. This investigation deals with a study of the anemia of protein deficiency in Rhesus monkeys. 2. Protein deficiency was induced in 17 rhesus monkeys. Seven animals, given a protein-rich diet, served as controls. The diets of both the groups were identical in all respects, except protein. All animals were tube-fed to ensure adequate caloric intake. Hematocrit, hemoglobin, erythroctye count, serum iron, serum iron binding capacity, plasma iron tolerance curves, and iron absorption using the Fe59 fecal recovery method were studied before and at intervals of the experiment in both deficient and control groups. Protein-deficient monkeys consistently developed normocytic normochromic anemia of moderate severity. A striking fall in serum iron binding capacity, total proteins and albumin with a rise in gamma globulin was observed in all deficient animals. A significant and comparable fall in serum iron was also observed. The Fe59 absorption was depressed and there was flattening of plasma iron tolerance curves. Two deficient animals, refed a high protein diet, showed reversal of all these changes. The control animals did not show any of these changes. The mechanism of anemia and decreased iron absorption observed in the protein-deficient animals and the relevance of these findings to those in Kwashiorkor are discussed

Structure of poly(propyl ether imine) (PETIM) dendrimer from fully atomistic molecular Dynamics Simulation and by Small Angle X-ray scattering

We study the structure of carboxylic acid terminated neutral poly (propyl ether imine) (PETIM) dendrimer from generation 1 through 6 (G1-G6) in a good solvent (water) by fully atomistic molecular dynamics (MD) simulations. We determine as a function of generation such structural properties as: radius of gyration, shape tensor, asphericity, fractal dimension, monomer density distribution, and end-group distribution functions. The sizes obtained from the MD simulations have been validated by Small Angle X-Ray Scattering (SAXS) experiment on dendrimer of generation 2 to 4 (G2-G4). A good agreement between the experimental and theoretical value of radius of gyration has been observed. We find a linear increase in radius of gyration with the generation. In contrast, Rg scales as ~ N^x with the number of monomers. We find two distinct exponents depending on the generations: x = 0.47 for G1-G3 and x = 0.28 for G3-G6 which reveals their non-space filling nature. In comparison with the amine terminated PAMAM dendrimer, we find Rg of G-th generation PETIM dendrimer is nearly equal to that of (G+1)-th generation of PAMAM dendrimer as observed by Maiti et. al. [Macromolecules,38, 979 2005]. We find substantial back folding of the outer sub generations into the interior of the dendrimer. Due to their highly flexible nature of the repeating branch units, the shape of the PETIM dendrimer deviates significantly from the spherical shape and the molecules become more and more spherical as the generation increases. The interior of the dendrimer is quite open with internal cavities available for accommodating guest molecules suggesting using PETIM dendrimer for guest-host applications. We also give a quantitative measure of the number of water molecules present inside the dendrimer.Comment: 33 page

Rapidity distribution as a probe for elliptical flow at intermediate energies

Interplay between the spectator and participant matter in heavy-ion collisions is investigated within isospin dependent quantum molecular dynamics (IQMD) model in term of rapidity distribution of light charged particles. The effect of different types and size rapidity distributions is studied in elliptical flow. The elliptical flow patterns show important role of the nearby spectator matter on the participant zone. This role is further explained on the basis of passing time of the spectator and expansion time of the participant zone. The transition from the in-plane to out-of-plane is observed only when the mid-rapidity region is included in the rapidity bin, otherwise no transition occurs. The transition energy is found to be highly sensitive towards the size of the rapidity bin, while weakly on the type of the rapidity distribution. The theoretical results are also compared with the experimental findings and are found in good agreement.Comment: 8 figure

Evolutionary dynamics on degree-heterogeneous graphs

The evolution of two species with different fitness is investigated on degree-heterogeneous graphs. The population evolves either by one individual dying and being replaced by the offspring of a random neighbor (voter model (VM) dynamics) or by an individual giving birth to an offspring that takes over a random neighbor node (invasion process (IP) dynamics). The fixation probability for one species to take over a population of N individuals depends crucially on the dynamics and on the local environment. Starting with a single fitter mutant at a node of degree k, the fixation probability is proportional to k for VM dynamics and to 1/k for IP dynamics.Comment: 4 pages, 4 figures, 2 column revtex4 format. Revisions in response to referee comments for publication in PRL. The version on arxiv.org has one more figure than the published PR

Low temperature and high pressure Raman and x-ray studies of pyrochlore Tb2_2Ti2_2O7_7 : phonon anomalies and possible phase transition

We have carried out temperature and pressure-dependent Raman and x-ray measurements on single crystals of Tb$_2$Ti$_2$O$_7$. We attribute the observed anomalous temperature dependence of phonons to phonon-phonon anharmonic interactions. The quasiharmonic and anharmonic contributions to the temperature-dependent changes in phonon frequencies are estimated quantitatively using mode Gr\"{u}neisen parameters derived from pressure-dependent Raman experiments and bulk modulus from high pressure x-ray measurements. Further, our Raman and x-ray data suggest a subtle structural deformation of the pyrochlore lattice at $\sim$ 9 GPa. We discuss possible implications of our results on the spin-liquid behaviour of Tb$_2$Ti$_2$O$_7$.Comment: 10 figures, 26 pages. Appeared in Physical Review B, vol-79, pp-134112 (2009

Romanian Tritium for Nuclear Fusion

The demand for tritium is expected to increase when ITER (the International Thermonuclear Experimental Reactor) begins operation in the mid-2020s. Romania is expected to detritiate its CANDU (Canada Deuterium Uranium) units at Cernavoda starting 2024, with the goal of improving radiological safety and reactor performance. Detritiation will result in a significant quantity of tritium being produced and thus Romania has an opportunity to supply tritium for fusion. In this assessment, ITER has been used as a reference device requiring tritium, as the projected tritium extraction schedule from Cernavoda aligns favourably with ITER operation. The findings suggest that Romania is capable of providing a total of 6.2 kg of tritium to ITER over its 20 year operation, generating a potential revenue of $186 M (USD). Opportunities associated with the supply of Romanian helium-3 are also considered as a hedging option, which has the potential to generate$120 M (USD) in the case of zero tritium sales. Greater involvement in future fission-fusion tritium-related activities through experience in tritium technologies is also discussed as a unique opportunity for Romania

Random elastic networks : strong disorder renormalization approach

For arbitrary networks of random masses connected by random springs, we define a general strong disorder real-space renormalization (RG) approach that generalizes the procedures introduced previously by Hastings [Phys. Rev. Lett. 90, 148702 (2003)] and by Amir, Oreg and Imry [Phys. Rev. Lett. 105, 070601 (2010)] respectively. The principle is to eliminate iteratively the elementary oscillating mode of highest frequency associated with either a mass or a spring constant. To explain the accuracy of the strong disorder RG rules, we compare with the Aoki RG rules that are exact at fixed frequency.Comment: 8 pages, v2=final versio

Random walks on the Apollonian network with a single trap

Explicit determination of the mean first-passage time (MFPT) for trapping problem on complex media is a theoretical challenge. In this paper, we study random walks on the Apollonian network with a trap fixed at a given hub node (i.e. node with the highest degree), which are simultaneously scale-free and small-world. We obtain the precise analytic expression for the MFPT that is confirmed by direct numerical calculations. In the large system size limit, the MFPT approximately grows as a power-law function of the number of nodes, with the exponent much less than 1, which is significantly different from the scaling for some regular networks or fractals, such as regular lattices, Sierpinski fractals, T-graph, and complete graphs. The Apollonian network is the most efficient configuration for transport by diffusion among all previously studied structure.Comment: Definitive version accepted for publication in EPL (Europhysics Letters

Correlated Prompt Fission Data in Transport Simulations

Detailed information on the fission process can be inferred from the observation, modeling and theoretical understanding of prompt fission neutron and $\gamma$-ray~observables. Beyond simple average quantities, the study of distributions and correlations in prompt data, e.g., multiplicity-dependent neutron and \gray~spectra, angular distributions of the emitted particles, $n$-$n$, $n$-$\gamma$, and $\gamma$-$\gamma$~correlations, can place stringent constraints on fission models and parameters that would otherwise be free to be tuned separately to represent individual fission observables. The FREYA~and CGMF~codes have been developed to follow the sequential emissions of prompt neutrons and $\gamma$-rays~from the initial excited fission fragments produced right after scission. Both codes implement Monte Carlo techniques to sample initial fission fragment configurations in mass, charge and kinetic energy and sample probabilities of neutron and $\gamma$~emission at each stage of the decay. This approach naturally leads to using simple but powerful statistical techniques to infer distributions and correlations among many observables and model parameters. The comparison of model calculations with experimental data provides a rich arena for testing various nuclear physics models such as those related to the nuclear structure and level densities of neutron-rich nuclei, the $\gamma$-ray~strength functions of dipole and quadrupole transitions, the mechanism for dividing the excitation energy between the two nascent fragments near scission, and the mechanisms behind the production of angular momentum in the fragments, etc. Beyond the obvious interest from a fundamental physics point of view, such studies are also important for addressing data needs in various nuclear applications. (See text for full abstract.)Comment: 39 pages, 57 figure files, published in Eur. Phys. J. A, reference added this versio