Bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon, FL (IRL) have tissue... more Bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon, FL (IRL) have tissue mercury concentrations among the highest reported worldwide. Analysis of total mercury (THg) concentrations in blood collected between 2003 and 2012 showed a significant linear decrease over time (p=0.04). Significant differences in the spatial distribution of THg in resident IRL dolphins were also observed with a general gradient in concentration from north to south. Evaluation of local biogeochemistry and accumulation of mercury in prey species is needed to better understand factors influencing the distribution of Hg in the apex predator. Analyses of temporal and spatial patterns of exposure to THg in this sentinel species may have implications for both ecosystem and public health in the region.
High-spin states of the [ital N]=49,50 nuclei [sup 85,86]Kr have been investigated via the reacti... more High-spin states of the [ital N]=49,50 nuclei [sup 85,86]Kr have been investigated via the reactions [sup 82]Se([sup 7]Li,[ital p]3[ital n]) or [sup 82]Se([sup 7]Li,[ital p]2[ital n]), respectively, using 32 MeV [sup 7]Li ions. In order to suppress [gamma] rays arising from pure neutron evaporation the measurements of angular distributions and relative excitation functions of the [gamma] rays as well as
Theoretical Aspects of Rationality and Knowledge, 1986
A propositional logic of distributed protocols is introduced which includes both the logic of kno... more A propositional logic of distributed protocols is introduced which includes both the logic of knowledge and temporal logic. Phenomena in distributed computing systems such as asynchronous time, incomplete knowledge by the computing agents in the system, and game-like behavior among the computing agents are all modeled in the logic. Two versions of the logic, the linear logic of protocols
This paper presents a framework for synthesizing efficient outof-core programs for block recursiv... more This paper presents a framework for synthesizing efficient outof-core programs for block recursive algorithms such as the fastFourier transform (FFT) and Batcher's bitonic sort. The blockrecursive algorithms considered in this paper are described usingtensor (Kronecker) product and other matrix operations. Thealgebraic properties of the matrix representation are used to deriveefficient out-of-core programs. These programs are targetedtowards a two-level disk model
Summary This paper presents an overview of recent experimental progress by the Duke DNA NanoTech ... more Summary This paper presents an overview of recent experimental progress by the Duke DNA NanoTech Group in our efforts to utilize novel DNA nanostructures for computational self-assembly as well as for templates in the fabrication of functional nano-patterned materials. We have prototyped a new DNA tile type known as the 4x4 (a cross-like structure composed of four four-arm junctions) upon
Molecular computing executed via local interactions of spatially contiguous set of molecules has ... more Molecular computing executed via local interactions of spatially contiguous set of molecules has potential advantages of (i) speed due to increased local concentration of reacting species, (ii) sharper switching behavior due to single molecule interactions, (iii) parallelism since each circuit operates independently of another and (iv) modularity and scalability due to the ability to reuse DNA sequences in spatially separated regions. We propose detailed designs for local molecular computations that involve spatially contiguous molecules arranged on addressable substrates. The circuit acts via enzyme-free DNA hybridization reaction cascades. Our designs include composable OR, AND, propagation Boolean gates and techniques to achieve higher degree fan-in and fan-out. A biophysical model of localized hybridization reactions is used to estimate the effect of locality on reaction rates. We also use the Visual DSD simulation software in conjunction with these localized reaction rates to s...
A propositional logic of distributed protocols is introduced which includes both the logic of kno... more A propositional logic of distributed protocols is introduced which includes both the logic of knowledge and temporal logic. Phenomena in distributed computing systems such as asynchronous time, incomplete knowledge by the computing agents in the system, and game-like ...
Polychlorinated biphenyls (PCBs), chlorinated pesticides (i.e., dichlorodiphenyltrichloroethane (... more Polychlorinated biphenyls (PCBs), chlorinated pesticides (i.e., dichlorodiphenyltrichloroethane (DDT) and its metabolites, chlordanes (CHLs), dieldrin, hexachlorobenzene (HCB), and mirex), polybrominated diphenyl ethers (PBDEs), perfluorinated chemicals (PFCs), and polyaromatic hydrocarbons (PAHs) were measured in blubber biopsy samples collected from 139 wild bottlenose dolphins (Tursiops truncatus) during 2003-2005 in Charleston (CHS), SC and the Indian River Lagoon (IRL), FL. Dolphins accumulated a similar suite of contaminants with summation operatorPCB dominating (CHS 64%, IRL 72%), followed by summation operatorDDT (CHS 20%, IRL 17%), summation operatorCHLs (CHS 7%; IRL 7%), summation operatorPBDE (CHS 4%, IRL 2%), PAH at 2%, and dieldrin, PFCs and mirex each 1% or less. Together summation operatorPCB and summation operatorDDT concentrations contributed approximately 87% of the total POCs measured in blubber of adult males. summation operatorPCBs in adult male dolphins exceed ...
There is a growing concern about the impacts of stress in marine mammals as they face a greater a... more There is a growing concern about the impacts of stress in marine mammals as they face a greater array of threats. The stress response of free-ranging dolphins (Tursiops truncatus) was examined by measuring their physiologic response to capture and handling. Samples were collected from 168 dolphins during capture-release health assessments 2003-2007 at two study sites: Charleston, SC (CHS) and the Indian River Lagoon, FL (IRL). Adrenocorticotropic hormone (ACTH), cortisol, aldosterone (ALD) and catecholamines (epinephrine (EPI), norepinephrine (NOR), dopamine (DA)), were measured in blood and cortisol in urine. Mean time to collect pre-examination samples after netting the animals was 22min; post-examination samples were taken prior to release (mean 1h 37min). EPI and DA concentrations decreased significantly with increased time to blood sampling. ACTH and cortisol levels increased from the initial capture event to the post-examination sample. EPI concentrations increased significantly with increasing time to the pre-examination sample and decreased significantly with time between the pre- and post-examination sample. Cortisol concentrations increased between the pre- and post-examination in CHS dolphins. Age- and sex-adjusted mean pre-examination values of catecholamines were significantly higher in CHS dolphins; ALD was higher in IRL dolphins. Significant differences related to age or sex included higher NOR concentrations in males; higher ALD and urine cortisol levels in juveniles than adults. Wild dolphins exhibited a typical mammalian response to acute stress of capture and restraint. Further studies that relate hormone levels to biological and health endpoints are warranted.
Javma-journal of The American Veterinary Medical Association, 2006
To determine the prevalence of lobomycosis, a mycotic infection of dolphins and humans caused by ... more To determine the prevalence of lobomycosis, a mycotic infection of dolphins and humans caused by a yeastlike organism (Lacazia loboi), among dolphins in the Indian River Lagoon in Florida. Cross-sectional study. 146 Atlantic bottlenose dolphins. Comprehensive health assessments of bottlenose dolphins in the Indian River Lagoon of Florida (n = 75) and in estuarine waters near Charleston, SC (71), were conducted during 2003 and 2004. Bottlenose dolphins were captured, examined, and released. Skin lesions were photographed and then biopsied. Tissue sections were stained with H&E and Gomori methenamine silver stains for identification of L. loboi. 9 of 30 (30%) dolphins captured in the southern portion of the Indian River Lagoon had lobomycosis, whereas none of the 45 dolphins captured in the northern portion of the lagoon or of the 71 dolphins captured near Charleston, SC, did. Affected dolphins had low serum alkaline phosphatase activities and high acute-phase protein concentrations. Results suggest that lobomycosis may be occurring in epidemic proportions among dolphins in the Indian River Lagoon. Localization of the disease to the southern portion of the lagoon, an area characterized by freshwater intrusion and lower salinity, suggests that exposure to environmental stressors may be contributing to the high prevalence of the disease, but specific factors are unknown. Because only dolphins and humans are naturally susceptible to infection, dolphins may represent a sentinel species for an emerging infectious disease.
In recent years, a number of research groups have begun developing nanofabrication methods based ... more In recent years, a number of research groups have begun developing nanofabrication methods based on DNA self-assembly. Here we review our recent experimental progress to utilize novel DNA nanostructures for self-assembly as well as for templates in the fabrication of functional nano-patterned materials. We have prototyped a new DNA nanostructure known as a cross structure. This nanostructure has a 4-fold
As part of conservation efforts between 1997 and 2001, more than 25% (332 animals) of the endange... more As part of conservation efforts between 1997 and 2001, more than 25% (332 animals) of the endangered Hawaiian monk seal (Monachus schauinslandi) population was sampled in the northwestern Hawaiian Islands. Serum samples were tested for antibodies to viruses, bacteria, and parasites known to cause morbidity and mortality in other marine mammal species. Antibodies were found to phocine herpesvirus-1 by using
The effects of occupational 60 Hz magnetic field and ambient light exposures on the pineal hormon... more The effects of occupational 60 Hz magnetic field and ambient light exposures on the pineal hormone, melatonin, were studied in 142 male electric utility workers in Colorado, 1995-1996. Melatonin was assessed by radioimmunoassay of its metabolite, 6-hydroxymelatonin sulfate (6-OHMS), in post-work shift urine samples. Personal magnetic field and light exposures were measured over 3 consecutive days using EMDEX C meters
Bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon, FL (IRL) have tissue... more Bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon, FL (IRL) have tissue mercury concentrations among the highest reported worldwide. Analysis of total mercury (THg) concentrations in blood collected between 2003 and 2012 showed a significant linear decrease over time (p=0.04). Significant differences in the spatial distribution of THg in resident IRL dolphins were also observed with a general gradient in concentration from north to south. Evaluation of local biogeochemistry and accumulation of mercury in prey species is needed to better understand factors influencing the distribution of Hg in the apex predator. Analyses of temporal and spatial patterns of exposure to THg in this sentinel species may have implications for both ecosystem and public health in the region.
High-spin states of the [ital N]=49,50 nuclei [sup 85,86]Kr have been investigated via the reacti... more High-spin states of the [ital N]=49,50 nuclei [sup 85,86]Kr have been investigated via the reactions [sup 82]Se([sup 7]Li,[ital p]3[ital n]) or [sup 82]Se([sup 7]Li,[ital p]2[ital n]), respectively, using 32 MeV [sup 7]Li ions. In order to suppress [gamma] rays arising from pure neutron evaporation the measurements of angular distributions and relative excitation functions of the [gamma] rays as well as
Theoretical Aspects of Rationality and Knowledge, 1986
A propositional logic of distributed protocols is introduced which includes both the logic of kno... more A propositional logic of distributed protocols is introduced which includes both the logic of knowledge and temporal logic. Phenomena in distributed computing systems such as asynchronous time, incomplete knowledge by the computing agents in the system, and game-like behavior among the computing agents are all modeled in the logic. Two versions of the logic, the linear logic of protocols
This paper presents a framework for synthesizing efficient outof-core programs for block recursiv... more This paper presents a framework for synthesizing efficient outof-core programs for block recursive algorithms such as the fastFourier transform (FFT) and Batcher's bitonic sort. The blockrecursive algorithms considered in this paper are described usingtensor (Kronecker) product and other matrix operations. Thealgebraic properties of the matrix representation are used to deriveefficient out-of-core programs. These programs are targetedtowards a two-level disk model
Summary This paper presents an overview of recent experimental progress by the Duke DNA NanoTech ... more Summary This paper presents an overview of recent experimental progress by the Duke DNA NanoTech Group in our efforts to utilize novel DNA nanostructures for computational self-assembly as well as for templates in the fabrication of functional nano-patterned materials. We have prototyped a new DNA tile type known as the 4x4 (a cross-like structure composed of four four-arm junctions) upon
Molecular computing executed via local interactions of spatially contiguous set of molecules has ... more Molecular computing executed via local interactions of spatially contiguous set of molecules has potential advantages of (i) speed due to increased local concentration of reacting species, (ii) sharper switching behavior due to single molecule interactions, (iii) parallelism since each circuit operates independently of another and (iv) modularity and scalability due to the ability to reuse DNA sequences in spatially separated regions. We propose detailed designs for local molecular computations that involve spatially contiguous molecules arranged on addressable substrates. The circuit acts via enzyme-free DNA hybridization reaction cascades. Our designs include composable OR, AND, propagation Boolean gates and techniques to achieve higher degree fan-in and fan-out. A biophysical model of localized hybridization reactions is used to estimate the effect of locality on reaction rates. We also use the Visual DSD simulation software in conjunction with these localized reaction rates to s...
A propositional logic of distributed protocols is introduced which includes both the logic of kno... more A propositional logic of distributed protocols is introduced which includes both the logic of knowledge and temporal logic. Phenomena in distributed computing systems such as asynchronous time, incomplete knowledge by the computing agents in the system, and game-like ...
Polychlorinated biphenyls (PCBs), chlorinated pesticides (i.e., dichlorodiphenyltrichloroethane (... more Polychlorinated biphenyls (PCBs), chlorinated pesticides (i.e., dichlorodiphenyltrichloroethane (DDT) and its metabolites, chlordanes (CHLs), dieldrin, hexachlorobenzene (HCB), and mirex), polybrominated diphenyl ethers (PBDEs), perfluorinated chemicals (PFCs), and polyaromatic hydrocarbons (PAHs) were measured in blubber biopsy samples collected from 139 wild bottlenose dolphins (Tursiops truncatus) during 2003-2005 in Charleston (CHS), SC and the Indian River Lagoon (IRL), FL. Dolphins accumulated a similar suite of contaminants with summation operatorPCB dominating (CHS 64%, IRL 72%), followed by summation operatorDDT (CHS 20%, IRL 17%), summation operatorCHLs (CHS 7%; IRL 7%), summation operatorPBDE (CHS 4%, IRL 2%), PAH at 2%, and dieldrin, PFCs and mirex each 1% or less. Together summation operatorPCB and summation operatorDDT concentrations contributed approximately 87% of the total POCs measured in blubber of adult males. summation operatorPCBs in adult male dolphins exceed ...
There is a growing concern about the impacts of stress in marine mammals as they face a greater a... more There is a growing concern about the impacts of stress in marine mammals as they face a greater array of threats. The stress response of free-ranging dolphins (Tursiops truncatus) was examined by measuring their physiologic response to capture and handling. Samples were collected from 168 dolphins during capture-release health assessments 2003-2007 at two study sites: Charleston, SC (CHS) and the Indian River Lagoon, FL (IRL). Adrenocorticotropic hormone (ACTH), cortisol, aldosterone (ALD) and catecholamines (epinephrine (EPI), norepinephrine (NOR), dopamine (DA)), were measured in blood and cortisol in urine. Mean time to collect pre-examination samples after netting the animals was 22min; post-examination samples were taken prior to release (mean 1h 37min). EPI and DA concentrations decreased significantly with increased time to blood sampling. ACTH and cortisol levels increased from the initial capture event to the post-examination sample. EPI concentrations increased significantly with increasing time to the pre-examination sample and decreased significantly with time between the pre- and post-examination sample. Cortisol concentrations increased between the pre- and post-examination in CHS dolphins. Age- and sex-adjusted mean pre-examination values of catecholamines were significantly higher in CHS dolphins; ALD was higher in IRL dolphins. Significant differences related to age or sex included higher NOR concentrations in males; higher ALD and urine cortisol levels in juveniles than adults. Wild dolphins exhibited a typical mammalian response to acute stress of capture and restraint. Further studies that relate hormone levels to biological and health endpoints are warranted.
Javma-journal of The American Veterinary Medical Association, 2006
To determine the prevalence of lobomycosis, a mycotic infection of dolphins and humans caused by ... more To determine the prevalence of lobomycosis, a mycotic infection of dolphins and humans caused by a yeastlike organism (Lacazia loboi), among dolphins in the Indian River Lagoon in Florida. Cross-sectional study. 146 Atlantic bottlenose dolphins. Comprehensive health assessments of bottlenose dolphins in the Indian River Lagoon of Florida (n = 75) and in estuarine waters near Charleston, SC (71), were conducted during 2003 and 2004. Bottlenose dolphins were captured, examined, and released. Skin lesions were photographed and then biopsied. Tissue sections were stained with H&E and Gomori methenamine silver stains for identification of L. loboi. 9 of 30 (30%) dolphins captured in the southern portion of the Indian River Lagoon had lobomycosis, whereas none of the 45 dolphins captured in the northern portion of the lagoon or of the 71 dolphins captured near Charleston, SC, did. Affected dolphins had low serum alkaline phosphatase activities and high acute-phase protein concentrations. Results suggest that lobomycosis may be occurring in epidemic proportions among dolphins in the Indian River Lagoon. Localization of the disease to the southern portion of the lagoon, an area characterized by freshwater intrusion and lower salinity, suggests that exposure to environmental stressors may be contributing to the high prevalence of the disease, but specific factors are unknown. Because only dolphins and humans are naturally susceptible to infection, dolphins may represent a sentinel species for an emerging infectious disease.
In recent years, a number of research groups have begun developing nanofabrication methods based ... more In recent years, a number of research groups have begun developing nanofabrication methods based on DNA self-assembly. Here we review our recent experimental progress to utilize novel DNA nanostructures for self-assembly as well as for templates in the fabrication of functional nano-patterned materials. We have prototyped a new DNA nanostructure known as a cross structure. This nanostructure has a 4-fold
As part of conservation efforts between 1997 and 2001, more than 25% (332 animals) of the endange... more As part of conservation efforts between 1997 and 2001, more than 25% (332 animals) of the endangered Hawaiian monk seal (Monachus schauinslandi) population was sampled in the northwestern Hawaiian Islands. Serum samples were tested for antibodies to viruses, bacteria, and parasites known to cause morbidity and mortality in other marine mammal species. Antibodies were found to phocine herpesvirus-1 by using
The effects of occupational 60 Hz magnetic field and ambient light exposures on the pineal hormon... more The effects of occupational 60 Hz magnetic field and ambient light exposures on the pineal hormone, melatonin, were studied in 142 male electric utility workers in Colorado, 1995-1996. Melatonin was assessed by radioimmunoassay of its metabolite, 6-hydroxymelatonin sulfate (6-OHMS), in post-work shift urine samples. Personal magnetic field and light exposures were measured over 3 consecutive days using EMDEX C meters
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