A low-cost hyperspectral scanner for natural imaging and the study of animal colour vision above and under water

Hyperspectral imaging is a widely used technology for industrial and scientific purposes, but the high cost and large size of commercial setups have made them impractical for most basic research. Here, we designed and implemented a fully open source and low-cost hyperspectral scanner based on a commercial spectrometer coupled to custom optical, mechanical and electronic components. We demonstrate our scanner's utility for natural imaging in both terrestrial and underwater environments. Our design provides sub-nm spectral resolution between 350-950 nm, including the UV part of the light spectrum which has been mostly absent from commercial solutions and previous natural imaging studies. By comparing the full light spectra from natural scenes to the spectral sensitivity of animals, we show how our system can be used to identify subtle variations in chromatic details detectable by different species. In addition, we have created an open access database for hyperspectral datasets collected from natural scenes in the UK and India. Together with comprehensive online build- and use-instructions, our setup provides an inexpensive and customisable solution to gather and share hyperspectral imaging data

Nanoscale Infrared Imaging Analysis of Carbonaceous Chondrites to Understand Organic-Mineral Interactions During Aqueous Alteration

Organic matter in carbonaceous chondrites is distributed in fine-grained matrix. To understand pre- and postaccretion history of organic matter and its association with surrounding minerals, microscopic techniques are mandatory. Infrared (IR) spectroscopy is a useful technique, but the spatial resolution of IR is limited to a few micrometers, due to the diffraction limit. In this study, we applied the high spatial resolution IR imaging method to CM2 carbonaceous chondrites Murchison and Bells, which is based on an atomic force microscopy (AFM) with its tip detecting thermal expansion of a sample resulting from absorption of infrared radiation. We confirmed that this technique permits 30 nm spatial resolution organic analysis for the meteorite samples. The IR imaging results are consistent with the previously reported association of organic matter and phyllosilicates, but our results are at much higher spatial resolution. This observation of heterogeneous distributions of the functional groups of organic matter revealed its association with minerals at 30 nm spatial resolution in meteorite samples by IR spectroscopy

Physician-led patient experience improvement efforts: The CONNECT program, an emerging innovation

In 2009, the leadership of the Children’s University Medical Group (CUMG) embarked on an effort to answer the question, “What would it take to promote and foster a culture of service amongst the medical staff?” The challenge was to engage the physician group in leading patient and family experience improvements within Seattle Children’s. In this article, an innovative, physician-designed and led approach to improving the patient experience is described. The effort focuses on encouraging local, grass roots strategies rooted in readily available and validated best practices. In support of that effort, novel tools that were developed and deployed to elicit input, engagement and self-assessment are also described

Maneuver Acoustic Flight Test of the Bell 430 Helicopter

A cooperative flight test by NASA, Bell Helicopter and the U.S. Army to characterize the steady state acoustics and measure the maneuver noise of a Bell Helicopter 430 aircraft was accomplished. The test occurred during June/July, 2011 at Eglin Air Force Base, Florida. This test gathered a total of 410 data points over 10 test days and compiled an extensive data base of dynamic maneuver measurements. Three microphone configurations with up to 31 microphones in each configuration were used to acquire acoustic data. Aircraft data included DGPS, aircraft state and rotor state information. This paper provides an overview of the test

Fovea-like photoreceptor specializations underlie single UV cone driven prey-capture behavior in zebrafish

In the eye, the function of same-type photoreceptors must be regionally adjusted to process a highly asymmetrical natural visual world. Here, we show that UV cones in the larval zebrafish area temporalis are specifically tuned for UV-bright prey capture in their upper frontal visual field, which may use the signal from a single cone at a time. For this, UV-photon detection probability is regionally boosted more than 10-fold. Next, in vivo two-photon imaging, transcriptomics, and computational modeling reveal that these cones use an elevated baseline of synaptic calcium to facilitate the encoding of bright objects, which in turn results from expressional tuning of phototransduction genes. Moreover, the light-driven synaptic calcium signal is regionally slowed by interactions with horizontal cells and later accentuated at the level of glutamate release driving retinal networks. These regional differences tally with variations between peripheral and foveal cones in primates and hint at a common mechanistic origin

The effect of brevenal on brevetoxin-induced DNA damage in human lymphocytes

Brevenal is a nontoxic short-chain trans-syn polyether that competes with brevetoxin (PbTx) for the active site on voltage-sensitive sodium channels. The PbTxs are highly potent polyether toxins produced during blooms of several species of marine dinoflagellates, most notably Karenia brevis. Blooms of K. brevis have been associated with massive fish kills, marine mammal poisoning, and are potentially responsible for adverse human health effects such as respiratory irritation and airway constriction in beach-goers. Additionally, the consumption of shellfish contaminated with PbTxs results in neurotoxic shellfish poisoning (NSP). The purpose of the present study was to determine whether PbTx could induce DNA damage in a human cell type, the lymphocyte, and if so, whether the damage could be antagonized or ameliorated by brevenal, a brevetoxin antagonist. The DNA damage may occur through both endogenous and exogenous physiological and pathophysiological processes. Unrepaired or erroneously repaired DNA damage may result in gene mutation, chromosome aberration, and modulation of gene regulation, which have been associated with immunotoxicity and carcinogenesis. A single-cell gel electrophoresis assay, or comet assay, was used to determine and compare DNA damage following various treatments. The data were expressed as tail moments, which is the percentage of DNA in the tail multiplied by the length between the center of the head and center of the tail (in arbitrary units). The negative control tail moment was 29.2 (SE=±0.9), whereas the positive control (hydrogen peroxide) was 72.1 (1.5) and solvent (ethanol) was 24.2 (2.1). The PbTx-2 (from Sigma, St. Louis, MO, USA), 10−8 M was 41.3 (3.6), PbTx-9 (Sigma), 10−8 M was 57.0 (5.3), PbTx-2 (from University of North Carolina at Wilmington, UNCW), 10−8 M was 49.4 (9.9), and PbTx-3 (UNCW), 10−8 M was 64.0 (6.4). 1.0 μg/ml brevenal applied 1 h before the PbTxs protected the lymphocytes from DNA damage; PbTx-2 (Sigma), 31.3 (2.1); PbTx-9 (Sigma), 35.5 (2.9); PbTx-2 (UNCW), 33.9 (1.4); PbTx-3 (UNCW), 34.9 (1.25). The tail moment for 1.0 μg/ml brevenal alone was 30.8 (2.6). The results indicate that extensive genotoxic damage is induced by PbTx-2 and 9 (Sigma), and PbTx-2 and 3 (UNCW) in normal human lymphocytes, which is fully antagonized by brevenal. This suggests that the immune systems of individuals exposed to PbTx during harmful algal bloom (HAB) events may be at risk. Originally published Archives in Toxicology, Vol. 79, No. 11, Nov 200

Learning at the Interstices; Locating Practical Philosophies for Understanding Physical/virtual Inter-spaces

Virtual worlds are relatively recent developments, and so it is tempting to believe that they need to be understood through newly developed theories and philosophies. However, humans have long thought about the nature of reality and what it means to be “real.” This paper examines the three persistent philosophical concepts of Metaxis, Liminality and Space that have evolved across more than 2000 years of meditation, contemplation and reflection. Our particular focus here is on the nature of the interface between the virtual and the physical: at the interstices, and how the nature of transactions and transitions across those interfaces may impact upon learning. This may, at first, appear to be an esoteric pursuit, but we ground our arguments in primary and secondary data from research studies in higher education

A multidomain spectral method for solving elliptic equations

We present a new solver for coupled nonlinear elliptic partial differential equations (PDEs). The solver is based on pseudo-spectral collocation with domain decomposition and can handle one- to three-dimensional problems. It has three distinct features. First, the combined problem of solving the PDE, satisfying the boundary conditions, and matching between different subdomains is cast into one set of equations readily accessible to standard linear and nonlinear solvers. Second, touching as well as overlapping subdomains are supported; both rectangular blocks with Chebyshev basis functions as well as spherical shells with an expansion in spherical harmonics are implemented. Third, the code is very flexible: The domain decomposition as well as the distribution of collocation points in each domain can be chosen at run time, and the solver is easily adaptable to new PDEs. The code has been used to solve the equations of the initial value problem of general relativity and should be useful in many other problems. We compare the new method to finite difference codes and find it superior in both runtime and accuracy, at least for the smooth problems considered here.Comment: 31 pages, 8 figure