A high-speed digital signal processor for atmospheric radar, part 7.3A

The Model SP-320 device is a monolithic realization of a complex general purpose signal processor, incorporating such features as a 32-bit ALU, a 16-bit x 16-bit combinatorial multiplier, and a 16-bit barrel shifter. The SP-320 is designed to operate as a slave processor to a host general purpose computer in applications such as coherent integration of a radar return signal in multiple ranges, or dedicated FFT processing. Presently available is an I/O module conforming to the Intel Multichannel interface standard; other I/O modules will be designed to meet specific user requirements. The main processor board includes input and output FIFO (First In First Out) memories, both with depths of 4096 W, to permit asynchronous operation between the source of data and the host computer. This design permits burst data rates in excess of 5 MW/s

Quantitative response of Alexandrium catenella cyst dormancy to cold exposure

Author Posting. © The Author(s), 2018. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Protist 169 (2018): 645-661, doi:10.1016/j.protis.2018.06.001.Many dinoflagellate cysts experience dormancy, a reversible state that prevents germination during unfavorable periods. Several of these species also cause harmful algal blooms (HABs), so a quantitative understanding of dormancy cycling is desired for better prediction and mitigation of bloom impacts. This study examines the effect of cold exposure on the duration of dormancy in Alexandrium catenella, a HAB dinoflagellate that causes paralytic shellfish poisoning (PSP). Mature, dormant cysts from Nauset Marsh (Cape Cod, MA USA) were stored at low but above freezing temperatures for up to six months. Dormancy status was then determined at regular intervals using a germination assay. Dormancy timing was variable among temperatures and was shorter in colder treatments, but the differences collapse when temperature and duration of storage are scaled by chilling-units (CU), a common horticultural predictor of plant and insect development in response to weather. Cysts within Nauset meet a well-defined chilling requirement by late January, after which they are poised to germinate with the onset of favorable conditions in spring. Cysts thus modulate their dormancy cycles in response to their temperature history, enhancing the potential for new blooms and improving this species’ adaptability to both unseasonable weather and new habitats/climate regimes.This work was supported by the National Science Foundation [OCE-0430724, OCE-0911031]; the National Institute of Environmental Health Sciences [1P50-ES01274201, 1P01ES021923]; the National Park Service Cooperative Agreement [H238015504]; and the Friends of Cape Cod National Seashore

Bacterial Isolates and Antimicrobial Susceptibility Phenotypes of Equine Specimens Submitted to the Oklahoma Animal Disease and Diagnostic Laboratory 2005-2007

Antimicrobial resistance is a topic of pervasive importance in both human and veterinary medicine. Increasingly, the zoonotic transfer of pathogens such as multi-drug resistance strains of Salmonella, methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus species is reported. The first step in responsible and effective use of antimicrobials in veterinary practice is to gain knowledge of the institutional and regional microbiologic environment. To this end, a large scale retrospective analysis was undertaken of all isolates from equine specimens submitted to the Oklahoma Animal Disease and Diagnostic Laboratory (OADDL) by the Boren Veterinary Medical Teaching Hospital, the College of Veterinary Health Sciences Ranch, and the regional veterinary community. Analysis was performed on pathogens identified, susceptibility phenotypes, and overall susceptibility patterns.The nature of bacterial isolates from equine specimens submitted to OADDL is similar to reported literature. Outbreaks of multi-drug resistant pathogens, particularly Staphylococcus aureus, have occurred at the BVMTH. These findings are supportive of real-time surveillance of major equine pathogens.Veterinary Pathobiolog

A quantitative assessment of the role of the parasite Amoebophrya in the termination of Alexandrium fundyense blooms within a small coastal embayment

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 8 (2013): e81150, doi:10.1371/journal.pone.0081150.Parasitic dinoflagellates of the genus Amoebophrya infect free-living dinoflagellates, some of which can cause harmful algal blooms (HABs). High prevalence of Amoebophrya spp. has been linked to the decline of some HABs in marine systems. The objective of this study was to evaluate the impact of Amoebophrya spp. on the dynamics of dinoflagellate blooms in Salt Pond (MA, USA), particularly the harmful species Alexandrium fundyense. The abundance of Amoebophrya life stages was estimated 3–7 days per week through the full duration of an annual A. fundyense bloom using fluorescence in situ hybridization coupled with tyramide signal amplification (FISH- TSA). More than 20 potential hosts were recorded including Dinophysis spp., Protoperidinium spp. and Gonyaulax spp., but the only dinoflagellate cells infected by Amoebophrya spp. during the sampling period were A. fundyense. Maximum A. fundyense concentration co-occurred with an increase of infected hosts, followed by a massive release of Amoebophrya dinospores in the water column. On average, Amoebophrya spp. infected and killed ~30% of the A. fundyense population per day in the end phase of the bloom. The decline of the host A. fundyense population coincided with a dramatic life-cycle transition from vegetative division to sexual fusion. This transition occurred after maximum infected host concentrations and before peak infection percentages were observed, suggesting that most A. fundyense escaped parasite infection through sexual fusion. The results of this work highlight the importance of high frequency sampling of both parasite and host populations to accurately assess the impact of parasites on natural plankton assemblages.L. Velo-Sua´rez was supported by a Marie Curie International Outgoing Fellowship (IOF; grant agreement: MOHAB PIOF-GA-252260). This work was supported in part by NSF grants OCE-0430724 and OCE-0911031 and National Institute of Environmental Health Sciences grants 1P50-ES01274201 and 1P01ES021923-01 to D.M. Anderson and D.J. McGillicuddy through the Woods Hole Center for Oceans and Human Health, National Park Service Cooperative Agreement H238015504 to D.M. Anderson

Evaluation of sxtA and rDNA qPCR assays through monitoring of an inshore bloom of Alexandrium catenella Group 1

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Murray, S. A., Ruvindy, R., Kohli, G. S., Anderson, D. M., & Brosnahan, M. L. Evaluation of sxtA and rDNA qPCR assays through monitoring of an inshore bloom of Alexandrium catenella Group 1. Scientific Reports, 9(1), (2019): 14532, doi:10.1038/s41598-019-51074-3.Alexandrium catenella (formerly A. tamarense Group 1, or A. fundyense) is the leading cause of Paralytic Shellfish Poisoning in North and South America, Europe, Africa, Australia and Asia. The quantification of A.catenella via sxtA, a gene involved in Paralytic Shellfish Toxin synthesis, may be a promising approach, but has not been evaluated in situ on blooms of A. catenella, in which cell abundances may vary from not detectable to in the order of 106 cells L−1. In this study, we compared sxtA assay performance to a qPCR assay targeted to a species-specific region of ribosomal DNA (rDNA) and an established fluorescent in situ hybridization (FISH) microscopy method. Passing-Bablok regression analyses revealed the sxtA assay to overestimate abundances when <5 cell equivalents A. catenella DNA were analysed, but otherwise was closer to microscopy estimates than the rDNA assay, which overestimated abundance across the full range of concentrations analysed, indicative of a copy number difference between the bloom population and a culture used for assay calibration a priori. In contrast, the sxtA assay performed more consistently, indicating less copy number variation. The sxtA assay was generally reliable, fast and effective in quantifying A. catenella and was predictive of PST contamination of shellfish.We thank the Australian Research Council for Funding (FT120100704). We thank Chowdhury Sarowar for the toxicity measurements, at the Sydney Institute of Marine Science. Support to MB and DA was provided by MIT Sea Grant (NA14OAR4170077) and the Woods Hole Center for Oceans and Human Health (National Science Foundation award OCE-1840381 and National Institute of Environmental Health Sciences award 1-P01-ES028938–01). We are grateful for assistance from David Kulis, Claire Mullen, and Isaac Rosenthal for assistance in the collection and processing of Salt Pond samples

Insights into the loss factors of phytoplankton blooms : the role of cell mortality in the decline of two inshore Alexandrium blooms

Author Posting. © The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Limnology and Oceanography 62 (2017): 1742–1753, doi:10.1002/lno.10530.While considerable effort has been devoted to understanding the factors regulating the development of phytoplankton blooms, the mechanisms leading to bloom decline and termination have received less attention. Grazing and sedimentation have been invoked as the main routes for the loss of phytoplankton biomass, and more recently, viral lysis, parasitism and programmed cell death (PCD) have been recognized as additional removal factors. Despite the importance of bloom declines to phytoplankton dynamics, the incidence and significance of various loss factors in regulating phytoplankton populations have not been widely characterized in natural blooms. To understand mechanisms controlling bloom decline, we studied two independent, inshore blooms of Alexandrium fundyense, paying special attention to cell mortality as a loss pathway. We observed increases in the number of dead cells with PCD features after the peak of both blooms, demonstrating a role for cell mortality in their terminations. In both blooms, sexual cyst formation appears to have been the dominant process leading to bloom termination, as both blooms were dominated by small-sized gamete cells near their peaks. Cell death and parasitism became more significant as sources of cell loss several days after the onset of bloom decline. Our findings show two distinct phases of bloom decline, characterized by sexual fusion as the initial dominant cell removal processes followed by elimination of remaining cells by cell death and parasitism.This article is a result of research funded by the National Oceanic and Atmospheric Administration Center for Sponsored Coastal Ocean Research ECOHAB program under award no. NA09NOS4780166 to the University of Texas Marine Science Institute (D.L.E) and the Woods Hole Center for Oceans and Human Health by National Science Foundation (NSF) award no. OCE-1314642 and National Institute of Environmental Health Sciences (NIEHS) award no. 1-P01-ES021923-014 to D.M.A. and M.L B

Progression of autosomal-dominant polycystic kidney disease in children1

Progression of autosomal-dominant polycystic kidney disease in children.BackgroundAlthough many case reports describe manifestations of autosomal-dominant polycystic kidney disease (ADPKD) in children, no longitudinal studies have examined the natural progression or risk factors for more rapid progression in a large number of children from ADPKD families.MethodsSince 1985, we have studied 312 children from 131 families with a history, a physical examination, blood and urine chemistries, an abdominal ultrasonography, and gene linkage analysis. One hundred fifteen of 185 affected children were studied multiple times for up to 15 years. Renal volumes were determined by ultrasound imaging. Graphs of mean renal volumes according to age were compared between affected and unaffected children, ADPKD children with and without early severe disease, and children with and without high blood pressure.ResultsAffected children had faster renal growth than unaffected children. ADPKD children with severe renal enlargement at a young age continued to experience faster renal growth than those with mild enlargement or normal kidney size for their age, and affected children with high blood pressure had faster renal growth than those with lower blood pressure. Glomerular filtration rate did not decrease in any children except for two with unusually severe early onset disease.ConclusionsThe progression of ADPKD clearly occurs in childhood and manifests as an increase in cyst number and renal size. This study identifies children at risk for rapid renal enlargement who may benefit the most from future therapeutic interventions

Temperature and residence time controls on an estuarine harmful algal bloom : modeling hydrodynamics and Alexandrium fundyense in Nauset estuary

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Estuaries and Coasts 38 (2015): 2240-2258, doi:10.1007/s12237-015-9949-z.A highly resolved, 3-d model of hydrodynamics and Alexandrium fundyense in an estuarine embayment has been developed to investigate the physical and biological controls on a recurrent harmful algal bloom. Nauset estuary on Cape Cod (MA, USA) consists of three salt ponds connected to the ocean through a shallow marsh and network of tidal channels. The model is evaluated using quantitative skill metrics against observations of physical and biological conditions during three spring blooms. The A. fundyense model is based on prior model applications for the nearby Gulf of Maine, but notable modifications were made to be consistent with the Nauset observations. The dominant factors controlling the A. fundyense bloom in Nauset were the water temperature, which regulates organism growth rates, and the efficient retention of cells due to bathymetric constraints, stratification, and cell behavior (diel vertical migration). Spring-neap variability in exchange altered residence times, but for cell retention to be substantially longer than the cell doubling time required both active vertical migration and stratification that inhibits mixing of cells into the surface layer by wind and tidal currents. Unlike in the Gulf of Maine, the model results were relatively insensitive to cyst distributions or germination rates. Instead, in Nauset, high apparent rates of vegetative cell division by retained populations dictated bloom development. Cyst germination occurred earlier in the year than in the Gulf of Maine, suggesting that Nauset cysts have different controls on germination timing. The model results were relatively insensitive to nutrient concentrations, due to eutrophic conditions in the highly impacted estuary or due to limitations in the spatial and temporal resolution of nutrient sampling. Cell loss rates were inferred to be extremely low during the growth phase of the bloom, but increased rapidly during the final phase due to processes that remain uncertain. The validated model allows a quantitative assessment of the factors that contribute to the development of a recurrent harmful algal bloom and provides a framework for assessing similarly impacted coastal systems.This work was supported by the National Science Foundation (OCE-0430724, OCE-0911031, and OCE-1314642) and National Institutes of Health (NIEHS-1P50-ES021923-01) through the Woods Hole Center for Oceans and Human Health, and by National Park Service (NPS) Cooperative Agreement H238015504.2016-03-1

Rapid growth and concerted sexual transitions by a bloom of the harmful dinoflagellate Alexandrium fundyense (Dinophyceae)

© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Limnology and Oceanography 60 (2015): 2059–2078, doi:10.1002/lno.10155.Transitions between life cycle stages by the harmful dinoflagellate Alexandrium fundyense are critical for the initiation and termination of its blooms. To quantify these transitions in a single population, an Imaging FlowCytobot (IFCB), was deployed in Salt Pond (Eastham, Massachusetts), a small, tidally flushed kettle pond that hosts near annual, localized A. fundyense blooms. Machine-based image classifiers differentiating A. fundyense life cycle stages were developed and results were compared to manually corrected IFCB samples, manual microscopy-based estimates of A. fundyense abundance, previously published data describing prevalence of the parasite Amoebophrya, and a continuous culture of A. fundyense infected with Amoebophrya. In Salt Pond, a development phase of sustained vegetative division lasted approximately 3 weeks and was followed by a rapid and near complete conversion to small, gamete cells. The gametic period (∼3 d) coincided with a spike in the frequency of fusing gametes (up to 5% of A. fundyense images) and was followed by a zygotic phase (∼4 d) during which cell sizes returned to their normal range but cell division and diel vertical migration ceased. Cell division during bloom development was strongly phased, enabling estimation of daily rates of division, which were more than twice those predicted from batch cultures grown at similar temperatures in replete medium. Data from the Salt Pond deployment provide the first continuous record of an A. fundyense population through its complete bloom cycle and demonstrate growth and sexual induction rates much higher than are typically observed in culture.National Science Foundation Grant Number: OCE-0430724, OCE-0911031, and OCE-1314642; National Institutes of Health Grant Number: NIEHS-1P50-ES021923-01; National Park Service (NPS) Cooperative Agreement Grant Number: H238015504; Gordon and Betty Moore Foundation Grant Number: #2649 to HMS; IOF Grant Number: MOHAB PIOF-GA-25226

The role of appetite-related hormones, adaptive thermogenesis, perceived hunger and stress in long-term weight-loss maintenance: a mixed-methods study

Background/objectives: Weight-loss maintenance is challenging, and few succeed in the long term. This study aimed to explain how appetite-related hormones, adaptive thermogenesis, perceived hunger and stress influence weight-loss maintenance. Subjects/methods: Fifteen adult women (age, 46.3 ± 9.5 years; BMI, 39.4 ± 4.3 kg/m2) participated in a 24-month intervention, which included 3–5 months total diet replacement (825–853 kcal/d). Body weight and composition (Magnetic Resonance Imaging), resting metabolic rate (indirect calorimetry), and fasting plasma concentration of leptin, ghrelin, glucagon-like peptide-1 (GLP-1), peptide YY (PYY), and growth differentiation factor 15 (GDF-15) were measured at baseline and after weight loss, around 6 months. Perceptions relating to weight-loss maintenance were explored using qualitative interviews. Results: Mean (SD) changes in body weight (−13.8 ± 6.3 kg) and total adipose tissue (−11.5 ± 4.9 kg) were significant (P &lt; 0.001). Weight loss was associated with a significant reduction in resting metabolic rate (−291 ± 226 kcal/day, P &lt; 0.001) and adaptive thermogenesis (−150 ± 162 kcal/day, P = 0.003), reduction in leptin (P &lt; 0.001) and GLP-1 (P = 0.015), an increase in ghrelin (P &lt; 0.001), and no changes in PYY and GDF-15. Weight regain between 6 and 24 months (6.1 ± 6.3 kg, P &lt; 0.05) was correlated positively with change in GLP-1 (r = 0.5, P = 0.037) and negatively with GLP-1 at baseline (r = −0.7, P = 0.003) and after weight loss (r = −0.7, P = 0.005). Participants did not report increased hunger after weight loss, and stress-related/emotional eating was perceived as the main reason for regain. Conclusions: Weight regain is more likely with lower fasting GLP-1 and greater reduction in GLP-1 after weight loss, but psychological aspects of eating behaviour appear as important in attenuating weight-loss maintenance