High Resolution Maps of the Vasculature of An Entire Organ

The structure of vascular networks represents a great, unsolved problem in anatomy. Network geometry and topology differ dramatically from left to right and person to person as evidenced by the superficial venation of the hands and the vasculature of the retinae. Mathematically, we may state that there is no conserved topology in vascular networks. Efficiency demands that these networks be regular on a statistical level and perhaps optimal. We have taken the first steps towards elucidating the principles underlying vascular organization, creating the rst map of the hierarchical vasculature (above the capillaries) of an entire organ. Using serial blockface microscopy and fluorescence imaging, we are able to identify vasculature at 5 μm resolution. We have designed image analysis software to segment, align, and skeletonize the resulting data, yielding a map of the individual vessels. We transformed these data into a mathematical graph, allowing computationally efficient storage and the calculation of geometric and topological statistics for the network. Our data revealed a complexity of structure unexpected by theory. We observe loops at all scales that complicate the assignment of hierarchy within the network and the existence of set length scales, implying a distinctly non-fractal structure of components within

Examination of oncology summer camp attendance, psychosocial adjustment, and perceived social support among pediatric cancer patients and siblings

Pediatric oncology patients and siblings are a population at-risk for negative psychosocial outcomes due to the various procedures, treatments, late effects, and family-based stressors associated with pediatric cancer. Pediatric oncology camps were designed to creatively address psychosocial gaps experienced by this steadily increasing population. Literature focusing on psychosocial adjustment of pediatric cancer patients and siblings is generally mixed or inconclusive, although there is some evidence suggesting increased psychosocial adjustment following camp participation. Research focusing on levels of perceived social support is limited. Although campers report social support as a main benefit of oncology camp participation, most studies are exploratory and yield inconsistent findings regarding demographic differences. In order to understand the effects of an oncology camp intervention on levels of psychosocial adjustment and perceived social support for pediatric cancer patients and siblings, an archival data set collected at a pediatric oncology camp (N = 64) was analyzed. There were 30 patients and 34 siblings in the sample, 37 females and 27 males, and with a mean age of 11.84 (SD = 2.89). Participants completed the Children’s Depression Inventory (CDI) and the Social Adjustment Domain (SA) from the Child Behavior Checklist – Youth Self-Report at three time points. Data was analyzed using repeated measures MANOVAs and results indicated that psychosocial adjustment increased significantly for adolescent females but not for other demographic groups. Additionally, perceived social support was found to increase for adolescent females but decrease for adolescent males, although other demographic groups did not appear to experience significant change over time. Strengths, limitations, and areas for future research are addressed as part of the discussion

Can the frequency-dependent specific heat be measured by thermal effusion methods?

It has recently been shown that plane-plate heat effusion methods devised for wide-frequency specific-heat spectroscopy do not give the isobaric specific heat, but rather the so-called longitudinal specific heat. Here it is shown that heat effusion in a spherical symmetric geometry also involves the longitudinal specific heat.Comment: Paper presented at the Fifth International Workshop on Complex Systems (Sendai, September, 2007), to appear in AIP Conference Proceeding

An upper bound on the second order asymptotic expansion for the quantum communication cost of state redistribution

State redistribution is the protocol in which given an arbitrary tripartite quantum state, with two of the subsystems initially being with Alice and one being with Bob, the goal is for Alice to send one of her subsystems to Bob, possibly with the help of prior shared entanglement.We derive an upper bound on the second order asymptotic expansion for the quantum communication cost of achieving state redistribution with a given finite accuracy. In proving our result, we also obtain an upper bound on the quantum communication cost of this protocol in the one-shot setting, by using the protocol of coherent state merging as a primitive

Tunable Vibrational Band Gaps in One-Dimensional Diatomic Granular Crystals with Three-Particle Unit Cells

We investigate the tunable vibration filtering properties of one-dimensional diatomic granular crystals composed of arrays of stainless steel spheres and cylinders interacting via Hertzian contact. The arrays consist of periodically repeated three-particle unit cells (steel-cylinder-sphere) in which the length of the cylinder is varied systematically. We apply static compression to linearize the dynamic response of the crystals and characterize their linear frequency spectrum. We find good agreement between theoretical dispersion relation analysis (for infinite systems), state-space analysis (for finite systems), and experiments. We report the observation of up to three distinct pass bands and two finite band gaps and show their tunability for variations in cylinder length and static compression

Speech Communication

Contains reports on two research projects.U. S. Air Force (Electronic Systems Division) under Contract AF19(628)-5661National Institutes of Health (Grant 5 RO1 NB-04332-04)Lincoln Laboratory, a center for research operated by the Massachusetts Institute of Technology, with support of the U.S. Air Forc

Macroscopically local correlations can violate information causality

Although quantum mechanics is a very successful theory, its foundations are still a subject of intense debate. One of the main problems is the fact that quantum mechanics is based on abstract mathematical axioms, rather than on physical principles. Quantum information theory has recently provided new ideas from which one could obtain physical axioms constraining the resulting statistics one can obtain in experiments. Information causality and macroscopic locality are two principles recently proposed to solve this problem. However none of them were proven to define the set of correlations one can observe. In this paper, we present an extension of information causality and study its consequences. It is shown that the two above-mentioned principles are inequivalent: if the correlations allowed by nature were the ones satisfying macroscopic locality, information causality would be violated. This gives more confidence in information causality as a physical principle defining the possible correlation allowed by nature.Comment: are welcome. 6 pages, 4 figs. This is the originally submitted version. The published version contains some bounds on quantum realizations of d2dd isotropic boxes (table 1), found by T. Vertesi, who kindly shared them with u

Human Time-Frequency Acuity Beats the Fourier Uncertainty Principle

The time-frequency uncertainty principle states that the product of the temporal and frequency extents of a signal cannot be smaller than $1/(4\pi)$. We study human ability to simultaneously judge the frequency and the timing of a sound. Our subjects often exceeded the uncertainty limit, sometimes by more than tenfold, mostly through remarkable timing acuity. Our results establish a lower bound for the nonlinearity and complexity of the algorithms employed by our brains in parsing transient sounds, rule out simple "linear filter" models of early auditory processing, and highlight timing acuity as a central feature in auditory object processing.Comment: 4 pages, 2 figures; Accepted at PR

Speech Communication

Contains research objectives, summary of research and reports on one research project.U.S. Air Force Cambridge Research Laboratories, Office of Aerospace Research, under Contract F19628-69-C-0044National Institutes of Health (Grant 2 RO1 NB-04332-07