Array Decomposition‐Fast Multipole Method for finite array analysis

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95440/1/rds5001.pd

Array decomposition-fast multipole method for finite array analysis

An innovative approach is presented for analyzing finite arrays of regularly spaced elements. We review the recently proposed Array Decomposition Method, which exploits the block-Toeplitz property of regularly spaced arrays for significant storage reduction. To further reduce storage, in this paper we incorporate a multipole expansion to treat distant element interactions. The suggested approach overcomes the matrix storage bottleneck associated with integral equation methods, resulting in fixed and minimal matrix storage for any sized array (on the same order as the storage of a single array element). Hence, fast and rigorous analysis of very large finite arrays can be accomplished with limited resources

Helping your partner with chronic pain: the importance of helping motivation, received social support, and its timeliness

Objective Like all intentional acts, social support provision varies with respect to its underlying motives. Greater autonomous or volitional motives (e.g., enjoyment, full commitment) to help individuals with chronic pain (ICPs) are associated with greater well-being benefits for the latter, as indexed by improved satisfaction of their psychological needs for autonomy, competence, and relatedness. The present study investigates the processes explaining why partners’ autonomous or volitional helping motivation yields these benefits. Methods A total of 134 couples, where at least one partner had chronic pain, completed a 14-day diary. Partners reported on their daily helping motives, whereas ICPs reported on their daily received support, timing of help, need-based experiences, and pain. Results On days when partners provided help for volitional motives, ICPs indicated receiving more help, which partially accounted for the effect of autonomous helping motivation on ICP need-based experiences. Timing of help moderated the effects of daily received support on ICP need-based experiences. Conclusions Findings highlight the importance of ICPs of receiving support in general and the role of timing in particular, which especially matters when there is little support being received.info:eu-repo/semantics/acceptedVersio

Quantification of HTLV-I proviral load in experimentally infected rabbits

BACKGROUND: Levels of proviral load in HTLV-1 infected patients correlate with clinical outcome and are reasonably prognostic. Adaptation of proviral load measurement techniques is examined here for use in an experimental rabbit model of HTLV-1 infection. Initial efforts sought to correlate proviral load with route and dose of inoculation and with clinical outcome in this model. These methods contribute to our continuing goal of using the model to test treatments that alleviate virus infection. RESULTS: A real-time PCR assay was used to measure proviral load in blood and tissue samples from a series of rabbits infected using HTLV-1 inocula prepared as either cell-free virus particles, infected cells or blood, or by naked DNA injection. Proviral loads from asymptomatically infected rabbits showed levels corresponding to those reported for human patients with clinically silent HTLV-1 infections. Proviral load was comparably increased in 50% of experimentally infected rabbits that developed either spontaneous benign or malignant tumors while infected. Similarly elevated provirus was found in organs of rabbits with experimentally induced acute leukemia/lymphoma-like disease. Levels of provirus in organs taken at necropsy varied widely suggesting that reservoirs of infections exist in non-lymphoid organs not traditionally thought to be targets for HTLV-1. CONCLUSION: Proviral load measurement is a valuable enhancement to the rabbit model for HTLV-1 infection providing a metric to monitor clinical status of the infected animals as well as a means for the testing of treatment to combat infection. In some cases proviral load in blood did not reflect organ proviral levels, revealing a limitation of this method for monitoring health status of HTLV-1 infected individuals

Prolonged dexamethasone exposure enhances zebrafish lateral-line regeneration but disrupts mitochondrial homeostasis and hair cell function

The synthetic glucocorticoid dexamethasone is commonly used to treat inner ear disorders. Previous work in larval zebrafish has shown that dexamethasone treatment enhances hair cell regeneration, yet dexamethasone has also been shown to inhibit regeneration of peripheral nerves after lesion. We therefore used the zebrafish model to determine the impact of dexamethasone treatment on lateral-line hair cells and primary afferents. To explore dexamethasone in the context of regeneration, we used copper sulfate (CuS

DNA metabarcoding unveils multiscale trophic variation in a widespread coastal opportunist

A thorough understanding of ecological networks relies on comprehensive information on trophic relationships among species. Since unpicking the diet of many organisms is unattainable using traditional morphology‐based approaches, the application of high‐throughput sequencing methods represents a rapid and powerful way forward. Here, we assessed the application of DNA metabarcoding with nearly universal primers for the mitochondrial marker cytochrome c oxidase I in defining the trophic ecology of adult brown shrimp, Crangon crangon, in six European estuaries. The exact trophic role of this abundant and widespread coastal benthic species is somewhat controversial, while information on geographical variation remains scant. Results revealed a highly opportunistic behaviour. Shrimp stomach contents contained hundreds of taxa (>1,000 molecular operational taxonomic units), of which 291 were identified as distinct species, belonging to 35 phyla. Only twenty ascertained species had a mean relative abundance of more than 0.5%. Predominant species included other abundant coastal and estuarine taxa, including the shore crab Carcinus maenas and the amphipod Corophium volutator. Jacobs’ selectivity index estimates based on DNA extracted from both shrimp stomachs and sediment samples were used to assess the shrimp's trophic niche indicating a generalist diet, dominated by crustaceans, polychaetes and fish. Spatial variation in diet composition, at regional and local scales, confirmed the highly flexible nature of this trophic opportunist. Furthermore, the detection of a prevalent, possibly endoparasitic fungus (Purpureocillium lilacinum) in the shrimp's stomach demonstrates the wide range of questions that can be addressed using metabarcoding, towards a more robust reconstruction of ecological networks

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