Improving surface current resolution using direction finding algorithms for multiantenna high-frequency radars

Author Posting. © American Meteorological Society, 2019. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of the Atmospheric and Oceanic Technology 36(10), (2019): 1997-2014, doi: 10.1175/JTECH-D-19-0029.1.While land-based high-frequency (HF) radars are the only instruments capable of resolving both the temporal and spatial variability of surface currents in the coastal ocean, recent high-resolution views suggest that the coastal ocean is more complex than presently deployed radar systems are able to reveal. This work uses a hybrid system, having elements of both phased arrays and direction finding radars, to improve the azimuthal resolution of HF radars. Data from two radars deployed along the U.S. East Coast and configured as 8-antenna grid arrays were used to evaluate potential direction finding and signal, or emitter, detection methods. Direction finding methods such as maximum likelihood estimation generally performed better than the well-known multiple signal classification (MUSIC) method given identical emitter detection methods. However, accurately estimating the number of emitters present in HF radar observations is a challenge. As MUSIC’s direction-of-arrival (DOA) function permits simple empirical tests that dramatically aid the detection process, MUSIC was found to be the superior method in this study. The 8-antenna arrays were able to provide more accurate estimates of MUSIC’s noise subspace than typical 3-antenna systems, eliminating the need for a series of empirical parameters to control MUSIC’s performance. Code developed for this research has been made available in an online repository.This analysis was supported by NSF Grants OCE-1657896 and OCE-1736930 to Kirincich, OCE-1658475 to Emery and Washburn and OCE-1736709 to Flament. Flament is also supported by NOAA’s Integrated Ocean Observing System through Award NA11NOS0120039. The authors thank Lindsey Benjamin, Alma Castillo, Ken Constantine, Benedicte Dousset, Ian Fernandez, Mael Flament, Dave Harris, Garrett Hebert, Ben Hodges, Victoria Futch, Matt Guanci, and Philip Moravcik for assistance in building, deploying, and operating the radars.2020-04-1

Altimeter processing tools for analyzing mesoscale ocean features

Satellite altimeters provide many opportunities for oceanographers to supplement their research with a valuable new data set. The recent GEOSAT exact repeat mission is the first of several altimeter missions proposed during the next decade. To utilize this new data, a software package was developed at the Woods Hole Oceanographic Institution and the University of Hawaii to facilitate the extraction of useful information from the NODC distributed GEOSAT data tapes. This software package was written with portability and modularity in mind. It should be possible to use this package with little or no modifications on data from future altimeters. The code was written in C and tested on Sun workstations and is oriented toward UNIX operating systems. However, since standard code was used, the programs should port easily to other computer systems. The modularity of the code should enable users to create additional programs. Additional programs designed to handle collocated water vapor corrections are also included for comparison.Funding was provided by the Office of Naval Research through Grant No. N00014-86-K-0751

Psychopathology And Functioning Among Children Of Treated Depressed Fathers And Mothers

Objective: Recent findings suggest that remissions of maternal depression are associated with decrease in offspring psychopathology. Little is known about the offspring effects of decrease in paternal depression. Method: The offspring of married fathers and married mothers were compared. The analysis was restricted to married parents to control for the confounding effect of single parenthood which was more prevalent among depressed mothers. At baseline all parents met criteria for major depressive disorder (MDD), and participated in a 3 month randomized controlled trial to treat depression with a 6 month follow-up. Married parents (N¼43) and their children aged 7–17 years (N¼78) were assessed independently through direct interviews of children and parents at baseline and followed for 9 months. Child assessors were blind to the clinical status of parents and uninvolved in their treatment. Results: At baseline, children of depressed fathers, compared to children of depressed mothers, had significantly fewer psychiatric disorders (11% vs. 37%; p¼ 0.012) and less impairment as measured by the Columbia Impairment Scale (6.5 vs. 11.6; p¼0.009). Over time, with treatment of parental depression, the prevalence of most child symptoms decreased among children of depressed mothers, but changed little among children of depressed fathers. Limitations: The main limitation of the study is the small number of fathers and their offspring included in the study. Conclusion: Maternal as compared to paternal depression had a greater impact on children. With treatment of parental depression the differential prevalence of child symptoms by parental gender narrowed over time. The clinical implication is that children may benefit from treatment of their depressed parents

Treatment Of Maternal Depression In A Medication Clinical Trial And Its Effect On Children

Objective: Observational studies show that when a depressed mother’s symptoms remit, her children’s psychiatric symptoms decrease. Using randomized treatment assignment, the authors sought to determine the differential effects of a depressed mother’s treatment on her child. Method: The study was a randomized double-blind 12-week trial of escitalopram, bupropion, or the combination of the two in depressed mothers (N=76), with independent assessment of their children (N=135; ages 7–17 years). Results: There were no significant treatment differences in mothers’ depressive symptoms or remission. Children’s depressive symptoms and functioning improved significantly among those whose mothers were in the escitalopram group (compared with those whose mothers were in the bupropion and combination treatment groups). Only in the escitalopram group was significant improvement of mother’s depression associated with improvement in the child’s symptoms. Exploratory analyses suggested that this may be due to changes in parental functioning: Mothers in the escitalopram group reported significantly greater improvement, compared with the other groups, in their ability to listen and talk to their children, who as a group reported that their mothers were more caring over the 12 weeks. Maternal baseline negative affectivity appeared to moderate the effect of maternal treatment on children, although the effect was not statistically significant. Children of mothers with low negative affectivity improved in all treatment groups. Children of mothers with high negative affectivity improved significantly only for those whose mothers were in the escitalopram group. Conclusions: The effects of the depressed mother’s improvement on her children may depend on her type of treatment. Depressed mothers with high anxious distress and irritability may require medications that reduce these symptoms in order to show the effect of her remission on her children

MCT Expression and Lactate Influx/Efflux in Tanycytes Involved in Glia-Neuron Metabolic Interaction

Metabolic interaction via lactate between glial cells and neurons has been proposed as one of the mechanisms involved in hypothalamic glucosensing. We have postulated that hypothalamic glial cells, also known as tanycytes, produce lactate by glycolytic metabolism of glucose. Transfer of lactate to neighboring neurons stimulates ATP synthesis and thus contributes to their activation. Because destruction of third ventricle (III-V) tanycytes is sufficient to alter blood glucose levels and food intake in rats, it is hypothesized that tanycytes are involved in the hypothalamic glucose sensing mechanism. Here, we demonstrate the presence and function of monocarboxylate transporters (MCTs) in tanycytes. Specifically, MCT1 and MCT4 expression as well as their distribution were analyzed in Sprague Dawley rat brain, and we demonstrate that both transporters are expressed in tanycytes. Using primary tanycyte cultures, kinetic analyses and sensitivity to inhibitors were undertaken to confirm that MCT1 and MCT4 were functional for lactate influx. Additionally, physiological concentrations of glucose induced lactate efflux in cultured tanycytes, which was inhibited by classical MCT inhibitors. Because the expression of both MCT1 and MCT4 has been linked to lactate efflux, we propose that tanycytes participate in glucose sensing based on a metabolic interaction with neurons of the arcuate nucleus, which are stimulated by lactate released from MCT1 and MCT4-expressing tanycytes

Quantitative assessment of the density of neurofibrillary tangles and senile plaques in senile dementia of the Alzheimer type. Comparison of immunocytochemistry with a specific antibody and Bodian's protargol method.

Counts of neurofibrillary tangles and senile plaques were performed in two adjacent sections from the temporal lobe in 14 women aged over 75 years at death. The mental status of these cases had been prospectively assessed by the test score of Blessed, Tomlinson and Roth. They were either intellectually normal or had senile dementia of the Alzheimer type of various degrees of severity. The first section was silver-impregnated according to Bodian's method; the second one was immunolabeled with an antiserum raised against neurofibrillary tangles. Densities of neurofibrillary tangles and senile plaques evaluated by the two techniques were highly correlated but their means of differences and limits of agreement were large. The correlation with the clinical data was similar for the two methods. Both techniques can thus be used with the same accuracy in correlative studies but their results are not interchangeable without caution.Comparative StudyJournal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe