Electrochemical Impedance Imaging via the Distribution of Diffusion Times

We develop a mathematical framework to analyze electrochemical impedance spectra in terms of a distribution of diffusion times (DDT) for a parallel array of random finite-length Warburg (diffusion) or Gerischer (reaction-diffusion) circuit elements. A robust DDT inversion method is presented based on Complex Nonlinear Least Squares (CNLS) regression with Tikhonov regularization and illustrated for three cases of nanostructured electrodes for energy conversion: (i) a carbon nanotube supercapacitor, (ii) a silicon nanowire Li-ion battery, and (iii) a porous-carbon vanadium flow battery. The results demonstrate the feasibility of non-destructive "impedance imaging" to infer microstructural statistics of random, heterogeneous materials

Mechanism design for spatio-temporal request satisfaction in mobile networks

Mobile agents participating in geo-presence-capable crowdsourcing applications should be presumed rational, competitive, and willing to deviate from their routes if given the right incentive. In this paper, we design a mechanism that takes into consideration this rationality for request satisfaction in such applications. We propose the Geo-temporal Request Satisfaction (GRS) problem to be that of finding the optimal assignment of requests with specific spatio-temporal characteristics to competitive mobile agents subject to spatio-temporal constraints. The objective of the GRS problem is to maximize the total profit of the system subject to our rationality assumptions. We define the problem formally, prove that it is NP-Complete, and present a practical solution mechanism, which we prove to be convergent, and which we evaluate experimentally.National Science Foundation (1012798, 0952145, 0820138, 0720604, 0735974

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 320)

This bibliography lists 125 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during January, 1989. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

Zeros of QCD partition function from finite density lattices

Partition function zeros steer the critical behavior of a system. Studying four-flavor lattice QCD at finite temperature and density with the Wilson-clover fermion action and the Iwasaki gauge action using a phase-quenched fermion determinant, we combine statistics from multiple chemical potentials to improve sampling of the configuration space, and aim at unraveling the movement of zeros in finite systems. Preparing for further investigations, we discuss methods and criteria used to sieve through complex parameter space spanned by $(\text{Re}\mu, \text{Im}\mu)$ and $(\text{Re}\mu, \text{Im}\beta)$, and present statistically robust zeros of the partition function.Comment: 7 pages, 1 table, and 8 figures, presented at the 31st International Symposium on Lattice Field Theory (Lattice 2013), 29 July - 3 August 2013, Mainz, Germany. Changes include: fix a typo and clarify the caption for Figure 1; clearly state estimating error for the number of independent configuration

Slow light in molecular aggregates nanofilms

We study slow light performance of molecular aggregates arranged in nanofilms by means of coherent population oscillations (CPO). The molecular cooperative behavior inside the aggregate enhances the delay of input signals in the GHz range in comparison with other CPO-based devices. Moreover, the problem of residual absorption present in CPO processes, is removed. We also propose an optical switch between different delays by exploiting the optical bistability of these aggregates.Comment: 4 pages, 4 figure

Assigning Deviant Youths to Minimize Total Harm

A common practice in the fields of education, mental health, and juvenile justice is to segregate problem youths in groups with deviant peers. Assignments of this sort, which concentrate deviant youths, may facilitate deviant peer influence and lead to perverse outcomes. This possibility adds to the list of arguments in support of "mainstreaming" whenever possible. But there are other concerns that help justify segregated-group assignments, including efficiency of service delivery and protection of the public. Our analysis organizes the discussion about the relevant tradeoffs. First, the number of deviant youths (relative to the size of the relevant population, or to the number of assignment locations) affects whether the harm-minimizing assignment calls for diffusion or segregation. Second, the nature of the problematic behavior is relevant; behavior which has a direct, detrimental effect on others who share the assignment makes a stronger case for segregation. Third, the capacity for behavior control matters, and may make the difference in a choice between segregation and integration. We briefly discuss the empirical literature, which with some exceptions is inadequate to the task of providing clear guidance about harm-minimizing assignment strategies. Finally, we reflect briefly on the medical-practice principle "first do no harm," and contrast it with the claims of potential victims of deviants.

Time and length scales of autocrine signals in three dimensions

A model of autocrine signaling in cultures of suspended cells is developed on the basis of the effective medium approximation. The fraction of autocrine ligands, the mean and distribution of distances traveled by paracrine ligands before binding, as well as the mean and distribution of the ligand lifetime are derived. Interferon signaling by dendritic immune cells is considered as an illustration.Comment: 15 page

Molecular Characterisation of Bacteriophage K Towards Applications for the Biocontrol of Pathogenic Staphylococci

End of project reportThe aim of this work was to characterise staphylococcal bacteriophage (a bacterial virus) and to assess their potential as therapeutic agents against pathogenic strains of Staphylococcus aureus, particularly mastitis-causing strains. The project included the use of two newly isolated phage CS1 and DW2, and an existing polyvalent phage. The new phage were isolated from the farmyard and characterised by electron microscopy and restriction analysis. Both phage were shown to belong to the Siphoviridae family and were lytic for representatives of all three clonal groups of Irish mastitis-associated staphylococci. A cocktail of three phage (CS1, DW2 and K) at 108 (plaque forming units) PFU/ml was infused into cows teats in animal trials. The lack of an increase in somatic cell counts in milks indicated strongly that the phage did not irritate the animal. In addition, the most potent phage used in this study, phage K, was further studied by genome sequencing, which revealed a linear DNA genome of 127,395 base pairs, which encodes 118 putative ORFs (open reading frames)