Passive therapy with humanized anti-staphylococcal enterotoxin B antibodies attenuates systemic inflammatory response and protects from lethal pneumonia caused by staphylococcal enterotoxin B-producing Staphylococcus aureus.

PubMed

Karau, Melissa J; Tilahun, Mulualem E; Krogman, Ashton; Osborne, Barbara A; Goldsby, Richard A; David, Chella S; Mandrekar, Jayawant N; Patel, Robin; Rajagopalan, Govindarajan

2017-10-03

Drugs such as linezolid that inhibit bacterial protein synthesis may be beneficial in treating infections caused by toxigenic Staphylococcus aureus. As protein synthesis inhibitors have no effect on preformed toxins, neutralization of pathogenic exotoxins with anti-toxin antibodies may be beneficial in conjunction with antibacterial therapy. Herein, we evaluated the efficacy of human-mouse chimeric high-affinity neutralizing anti-staphylococcal enterotoxin B (SEB) antibodies in the treatment of experimental pneumonia caused by SEB-producing S. aureus. Since HLA class II transgenic mice mount a stronger systemic immune response following challenge with SEB and are more susceptible to SEB-induced lethal toxic shock than conventional mice strains, HLA-DR3 transgenic mice were used. Lethal pneumonia caused by SEB-producing S. aureus in HLA-DR3 transgenic mice was characterized by robust T cell activation and elevated systemic levels of several pro-inflammatory cytokines and chemokines. Prophylactic administration of a single dose of linezolid 30 min prior to the onset of infection attenuated the systemic inflammatory response and protected from mortality whereas linezolid administered 60 min after the onset of infection failed to confer significant protection. Human-mouse chimeric high-affinity neutralizing anti-SEB antibodies alone, but not polyclonal human IgG, mitigated this response and protected from death when administered immediately after initiation of infection. Further, anti-SEB antibodies as well as intact polyclonal human IgG, but not its Fab or Fc fragments, protected from lethal pneumonia when followed with linezolid therapy 60 min later. In conclusion, neutralization of superantigens with high-affinity antibodies may have beneficial effects in pneumonia.

Staphylococcal enterotoxin-specific IgE antibodies in atopic dermatitis.

PubMed

Ide, Fumihito; Matsubara, Tomoyo; Kaneko, Miho; Ichiyama, Takashi; Mukouyama, Tokuko; Furukawa, Susumu

2004-06-01

The authors clarified the clinical significance of the measurement of serum concentrations of specific IgE antibodies to staphylococcal enterotoxin (SE) A- and SEB in atopic dermatitis (AD). The serum concentrations of SEA- and SEB-specific IgE antibodies in 140 pediatric patients with AD were measured with an immuno CAP -radioallergosorbent test system (RAST). To check the cross-reaction of specific IgE antibodies to SEA/SEB and other allergens, the CAP RAST fluorescent enzyme immunoassay inhibition test was performed. Forty-seven patients (33.6%) tested positive for either SEA- or SEB-specific IgE antibodies. School children showed higher positive rates of SEA/SEB-specific IgE antibodies than infants or young children. The patients with severe AD and those with exacerbation of symptoms in summer, had higher positive rates of SEA/SEB-specific IgE antibodies than patients with mild AD or those with exacerbation in winter. In addition, the positive rates of specific IgE antibodies to both dog-dander and cat-dander were higher in patients with positive SEA/SEB-specific IgE antibodies than in patients with negative ones. No cross-reactions occurred among specific IgE antibodies to SEA/SEB and dog/cat dander with one patient's serum, which had positive IgE-specific antibodies against cat/dog dander and SEA/SEB. The positive rate of SEA/SEB-specific IgE antibodies in the patients with dogs and/or cats as pets was 48.4%, which was higher than in those with no pets. Atopic dermatitis patients who exhibit high positive rates of SEA/SEB-specific IgE antibodies were found to be school children, severe cases, cases with high serum concentrations of total IgE, cases with exacerbation in summer, and cases with dogs and/or cats as pets. The measurement of serum concentrations of specific IgE antibodies to SEA and SEB, thus has some value for evaluating AD patients.

Se-SAD serial femtosecond crystallography datasets from selenobiotinyl-streptavidin

PubMed Central

Yoon, Chun Hong; DeMirci, Hasan; Sierra, Raymond G.; Dao, E. Han; Ahmadi, Radman; Aksit, Fulya; Aquila, Andrew L.; Batyuk, Alexander; Ciftci, Halilibrahim; Guillet, Serge; Hayes, Matt J.; Hayes, Brandon; Lane, Thomas J.; Liang, Meng; Lundström, Ulf; Koglin, Jason E.; Mgbam, Paul; Rao, Yashas; Rendahl, Theodore; Rodriguez, Evan; Zhang, Lindsey; Wakatsuki, Soichi; Boutet, Sébastien; Holton, James M.; Hunter, Mark S.

2017-01-01

We provide a detailed description of selenobiotinyl-streptavidin (Se-B SA) co-crystal datasets recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS) for selenium single-wavelength anomalous diffraction (Se-SAD) structure determination. Se-B SA was chosen as the model system for its high affinity between biotin and streptavidin where the sulfur atom in the biotin molecule (C10H16N2O3S) is substituted with selenium. The dataset was collected at three different transmissions (100, 50, and 10%) using a serial sample chamber setup which allows for two sample chambers, a front chamber and a back chamber, to operate simultaneously. Diffraction patterns from Se-B SA were recorded to a resolution of 1.9 Å. The dataset is publicly available through the Coherent X-ray Imaging Data Bank (CXIDB) and also on LCLS compute nodes as a resource for research and algorithm development. PMID:28440794

Se-SAD serial femtosecond crystallography datasets from selenobiotinyl-streptavidin

NASA Astrophysics Data System (ADS)

Yoon, Chun Hong; Demirci, Hasan; Sierra, Raymond G.; Dao, E. Han; Ahmadi, Radman; Aksit, Fulya; Aquila, Andrew L.; Batyuk, Alexander; Ciftci, Halilibrahim; Guillet, Serge; Hayes, Matt J.; Hayes, Brandon; Lane, Thomas J.; Liang, Meng; Lundström, Ulf; Koglin, Jason E.; Mgbam, Paul; Rao, Yashas; Rendahl, Theodore; Rodriguez, Evan; Zhang, Lindsey; Wakatsuki, Soichi; Boutet, Sébastien; Holton, James M.; Hunter, Mark S.

2017-04-01

We provide a detailed description of selenobiotinyl-streptavidin (Se-B SA) co-crystal datasets recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS) for selenium single-wavelength anomalous diffraction (Se-SAD) structure determination. Se-B SA was chosen as the model system for its high affinity between biotin and streptavidin where the sulfur atom in the biotin molecule (C10H16N2O3S) is substituted with selenium. The dataset was collected at three different transmissions (100, 50, and 10%) using a serial sample chamber setup which allows for two sample chambers, a front chamber and a back chamber, to operate simultaneously. Diffraction patterns from Se-B SA were recorded to a resolution of 1.9 Å. The dataset is publicly available through the Coherent X-ray Imaging Data Bank (CXIDB) and also on LCLS compute nodes as a resource for research and algorithm development.

Spatiotemporal variability in surface energy balance across tundra, snow and ice in Greenland.

PubMed

Lund, Magnus; Stiegler, Christian; Abermann, Jakob; Citterio, Michele; Hansen, Birger U; van As, Dirk

2017-02-01

The surface energy balance (SEB) is essential for understanding the coupled cryosphere-atmosphere system in the Arctic. In this study, we investigate the spatiotemporal variability in SEB across tundra, snow and ice. During the snow-free period, the main energy sink for ice sites is surface melt. For tundra, energy is used for sensible and latent heat flux and soil heat flux leading to permafrost thaw. Longer snow-free period increases melting of the Greenland Ice Sheet and glaciers and may promote tundra permafrost thaw. During winter, clouds have a warming effect across surface types whereas during summer clouds have a cooling effect over tundra and a warming effect over ice, reflecting the spatial variation in albedo. The complex interactions between factors affecting SEB across surface types remain a challenge for understanding current and future conditions. Extended monitoring activities coupled with modelling efforts are essential for assessing the impact of warming in the Arctic.

Preparation and properties of banana fiber-reinforced composites based on high density polyethylene (HDPE)/Nylon-6 blends.

PubMed

Liu, H; Wu, Q; Zhang, Q

2009-12-01

Banana fiber (BaF)-filled composites based on high density polyethylene (HDPE)/Nylon-6 blends were prepared via a two-step extrusion method. Maleic anhydride grafted styrene/ethylene-butylene/styrene triblock polymer (SEBS-g-MA) and maleic anhydride grafted polyethylene (PE-g-MA) were used to enhance impact performance and interfacial bonding between BaF and the resins. Mechanical, crystallization/melting, thermal stability, water absorption, and morphological properties of the composites were investigated. In the presence of SEBS-g-MA, better strengths and moduli were found for HDPE/Nylon-6 based composites compared with corresponding HDPE based composites. At a fixed weight ratio of PE-g-MA to BaF, an increase of BaF loading up to 48.2 wt.% led to a continuous improvement in moduli and flexural strength of final composites, while impact toughness was lowered gradually. Predicted tensile modulus by the Hones-Paul model for three-dimensional random fiber orientation agreed well with experimental data at the BaF loading of 29.3 wt.%. However, the randomly-oriented fiber models underestimated experimental data at higher fiber levels. It was found that the presence of SEBS-g-MA had a positive influence on reinforcing effect of the Nylon-6 component in the composites. Thermal analysis results showed that fractionated crystallization of the Nylon-6 component in the composites was induced by the addition of both SEBS-g-MA and PE-g-MA. Thermal stability of both composite systems differed slightly, except an additional decomposition peak related to the minor Nylon-6 for the composites from the HDPE/Nylon-6 blends. In the presence of SEBS-g-MA, the addition of Nylon-6 and increased BaF loading level led to an increase in the water absorption value of the composites.

Simplified energy-balance model for pragmatic multi-dimensional device simulation

NASA Astrophysics Data System (ADS)

Chang, Duckhyun; Fossum, Jerry G.

1997-11-01

To pragmatically account for non-local carrier heating and hot-carrier effects such as velocity overshoot and impact ionization in multi-dimensional numerical device simulation, a new simplified energy-balance (SEB) model is developed and implemented in FLOODS[16] as a pragmatic option. In the SEB model, the energy-relaxation length is estimated from a pre-process drift-diffusion simulation using the carrier-velocity distribution predicted throughout the device domain, and is used without change in a subsequent simpler hydrodynamic (SHD) simulation. The new SEB model was verified by comparison of two-dimensional SHD and full HD DC simulations of a submicron MOSFET. The SHD simulations yield detailed distributions of carrier temperature, carrier velocity, and impact-ionization rate, which agree well with the full HD simulation results obtained with FLOODS. The most noteworthy feature of the new SEB/SHD model is its computational efficiency, which results from reduced Newton iteration counts caused by the enhanced linearity. Relative to full HD, SHD simulation times can be shorter by as much as an order of magnitude since larger voltage steps for DC sweeps and larger time steps for transient simulations can be used. The improved computational efficiency can enable pragmatic three-dimensional SHD device simulation as well, for which the SEB implementation would be straightforward as it is in FLOODS or any robust HD simulator.

Dietary Animal Plasma Proteins Improve the Intestinal Immune Response in Senescent Mice.

PubMed

Miró, Lluïsa; Garcia-Just, Alba; Amat, Concepció; Polo, Javier; Moretó, Miquel; Pérez-Bosque, Anna

2017-12-11

Increased life expectancy has promoted research on healthy aging. Aging is accompanied by increased non-specific immune activation (inflammaging) which favors the appearance of several disorders. Here, we study whether dietary supplementation with spray-dried animal plasma (SDP), which has been shown to reduce the activation of gut-associated lymphoid tissue (GALT) in rodents challenged by S. aureus enterotoxin B (SEB), and can also prevent the effects of aging on immune system homeostasis. We first characterized GALT in a mouse model of accelerated senescence (SAMP8) at different ages (compared to mice resistant to accelerated senescence; SAMR1). Second, we analyzed the SDP effects on GALT response to an SEB challenge in SAMP8 mice. In GALT characterization, aging increased the cell number and the percentage of activated Th lymphocytes in mesenteric lymph nodes and Peyer's patches (all, p < 0.05), as well as the expression of IL-6 and TNF-α in intestinal mucosa (both, p < 0.05). With respect to GALT response to the SEB challenge, young mice showed increased expression of intestinal IL-6 and TNF-α, as well as lymphocyte recruitment and activation (all, p < 0.05). However, the immune response of senescent mice to the SEB challenge was weak, since SEB did not change cell recruitment or the percentage of activated Th lymphocytes. Mice supplemented with SDP showed improved capacity to respond to the SEB challenge, similar to the response of the young mice. These results indicate that senescent mice have an impaired mucosal immune response characterized by unspecific GALT activation and a weak specific immune response. SDP supplementation reduces non-specific basal immune activation, allowing for the generation of specific responses.

Deformational characteristics of thermoplastic elastomers

NASA Astrophysics Data System (ADS)

Indukuri, Kishore K.

This thesis focuses primarily on the structure-property relationships of poly (styrene-ethylene-butylene-styrene) triblock copolymer TPEs. First evidence for strain-induced crystallization occurring in certain SEBS block copolymers has been established using unique techniques like deformation calorimetry, combined in-situ small angle X-ray and wide angle X-ray diffraction (SAXD/WAXD). Also the ramifications of such strain-induced crystallization on the mechanical properties like cyclic hysteresis, stress relaxation/creep retention of these SEBS systems have been studied. In addition, the structural changes in the morphology of these systems on deformation have been investigated using combined SAXD/WAXD setup. Small angle X-ray diffraction probed the changes at the nano-scale of polystyrene (PS) cylinders, while wide angle X-ray diffraction probed the changes at molecular length scales of the amorphous/crystalline domains of the elastomeric mid-block in these systems. New structural features at both these length scales have been observed and incorporated into the overall deformation mechanisms of the material. Continuous processing techniques like extrusion have been used to obtain ultra long-range order and orientation in these SEBS systems. Thus well ordered crystal like hexagonal packing of cylinders, where in each element in this hexagonal lattice can be individually addressed without any grain boundaries can be realized using these robust techniques. The effect of long-range order/orientation on the mechanical properties has been studied. In addition, these well ordered systems serve as model systems for evaluating deformation mechanisms of these SEBS systems, where the relative contributions of each of the phases can be estimated. EPDM/i-PP thermoplastic vulcanizates (TPVs) have micron size scale phase separated morphologies of EPDM rubber dispersed in a semicrystalline i-PP matrix as a result of the dynamic vulcanization process. Confocal microscopy studies, along with scanning electron microscopy (SEM) studies show that the morphology of these EPDM/i-PP systems resembles a microcellular "filled" foam in which i-PP occupies the strut regions and EPDM the inner core. Based on this, an analytical model has been developed that takes into account composition information, molecular weight, cure state and morphology into account.

Rapid purification of staphylococcal enterotoxin B by high-pressure liquid chromatography.

PubMed Central

Strickler, M P; Neill, R J; Stone, M J; Hunt, R E; Brinkley, W; Gemski, P

1989-01-01

The Staphylococcus aureus enterotoxins represent a group of proteins that cause emesis and diarrhea in humans and other primates. We have developed a rapid two-step high-pressure liquid chromatography (HPLC) procedure for purification of staphylococcal enterotoxin B (SEB). Sterile filtrates (2.5 liters) of strain 10-275 were adsorbed directly onto a reversed-phase column (50 mm by 30 cm Delta Pak; 300 A [30 nm], 15 microns, C18). SEB was obtained by using a unique sequential gradient system. First, an aqueous ammonium acetate to acetonitrile gradient followed by an aqueous trifluoroacetic acid (TFA) wash was used to remove contaminants. A subsequent TFA to acetonitrile-TFA gradient eluted the bound SEB. Further purification was obtained by rechromatography on a cation-exchange column. From 35 to 45% of the SEB in starting filtrates was recovered. Analysis by immunoblotting of samples separated on sodium dodecyl sulfate-polyacrylamide gels indicated that HPLC-purified SEB exhibited immunological and biochemical properties similar to those of the SEB standard. Induction of an emetic response in rhesus monkeys showed that the HPLC-purified toxin also retained biological activity. Images PMID:2745678

Se-SAD serial femtosecond crystallography datasets from selenobiotinyl-streptavidin

DOE PAGES

Yoon, Chun Hong; DeMirci, Hasan; Sierra, Raymond G.; ...

2017-04-25

We provide a detailed description of selenobiotinyl-streptavidin (Se-B SA) co-crystal datasets recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS) for selenium single-wavelength anomalous diffraction (Se-SAD) structure determination. Se-B SA was chosen as the model system for its high affinity between biotin and streptavidin where the sulfur atom in the biotin molecule (C 10H 16N 2O 3S) is substituted with selenium. The dataset was collected at three different transmissions (100, 50, and 10%) using a serial sample chamber setup which allows for two sample chambers, a front chamber and a back chamber, to operatemore » simultaneously. Diffraction patterns from Se-B SA were recorded to a resolution of 1.9 Å. The dataset is publicly available through the Coherent X-ray Imaging Data Bank (CXIDB) and also on LCLS compute nodes as a resource for research and algorithm development.« less

Se-SAD serial femtosecond crystallography datasets from selenobiotinyl-streptavidin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoon, Chun Hong; DeMirci, Hasan; Sierra, Raymond G.

We provide a detailed description of selenobiotinyl-streptavidin (Se-B SA) co-crystal datasets recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS) for selenium single-wavelength anomalous diffraction (Se-SAD) structure determination. Se-B SA was chosen as the model system for its high affinity between biotin and streptavidin where the sulfur atom in the biotin molecule (C 10H 16N 2O 3S) is substituted with selenium. The dataset was collected at three different transmissions (100, 50, and 10%) using a serial sample chamber setup which allows for two sample chambers, a front chamber and a back chamber, to operatemore » simultaneously. Diffraction patterns from Se-B SA were recorded to a resolution of 1.9 Å. The dataset is publicly available through the Coherent X-ray Imaging Data Bank (CXIDB) and also on LCLS compute nodes as a resource for research and algorithm development.« less

The Anti-Inflammatory Effect of Spray-Dried Plasma Is Mediated by a Reduction in Mucosal Lymphocyte Activation and Infiltration in a Mouse Model of Intestinal Inflammation.

PubMed

Pérez-Bosque, Anna; Miró, Lluïsa; Amat, Concepció; Polo, Javier; Moretó, Miquel

2016-10-22

Spray-dried preparations from porcine and bovine plasma can alleviate mucosal inflammation in experimental models and improve symptoms in patients with enteropathy. In rodents, dietary supplementation with porcine spray-dried plasma (SDP) attenuates intestinal inflammation and improves the epithelial barrier function during intestinal inflammation induced by Staphylococcus aureus enterotoxin B (SEB). The aim of this study was to discern the molecular mechanisms involved in the anti-inflammatory effects of SDP. Male C57BL/6 mice were fed with 8% SDP or control diet (based on milk proteins) for two weeks, from weaning until day 33. On day 32, the mice were given a SEB dose (i.p., 25 µg/mouse) or vehicle. SEB administration increased cell recruitment to mesenteric lymph nodes and the percentage of activated Th lymphocytes and SDP prevented these effects). SDP supplementation increased the expression of interleukin 10 (IL-10) or transforming growth factor- β (TGF-β) compared to the SEB group. The SEB challenge increased six-fold the expression of mucosal addressin cell adhesion molecule 1 (MAdCAM-1) and intercellular adhesion molecule 1 (ICAM-1); and these effects were attenuated by SDP supplementation. SEB also augmented NF-κB phosphorylation, an effect that was prevented by dietary SDP. Our results indicate that the anti-inflammatory effects of SDP involve the regulation of transcription factors and adhesion molecules that reduce intestinal cell infiltration and the degree of the inflammatory response.

Reconnoitering the effect of shallow groundwater on land surface temperature and surface energy balance using MODIS and SEBS

USDA-ARS?s Scientific Manuscript database

The possibility of observing shallow groundwater depth and areal extent using satellite measurements can support groundwater models and vast irrigation systems management. Besides, these measurements help to integrate groundwater effects on surface energy balance within land surface models and clima...

Maternal immune activation with staphylococcal enterotoxin A produces unique behavioral changes in C57BL/6 mouse offspring.

PubMed

Glass, Ruthy; Norton, Sara; Fox, Nicholas; Kusnecov, Alexander W

2018-05-14

Stimulation of the immune system during pregnancy, known as maternal immune activation (MIA), can cause long-lasting neurobiological and behavioral changes in the offspring. This phenomenon has been implicated in the etiology of developmental psychiatric disorders, such as autism and schizophrenia. Much of this evidence is predicated on animal models using bacterial agents such as LPS and/or viral mimics such as Poly I:C, both of which act through toll-like receptors. However, fewer studies have examined the role of direct activation of maternal T-cells during pregnancy using microbial agents. Bacterial superantigens, such as Staphylococcal Enterotoxin A and B (SEA; SEB), are microbial proteins that activate CD4 + T-cells and cause prominent T-cell proliferation and cytokine production. We injected pregnant and non-pregnant adult female C57BL/6 mice with 200 μg/Kg of SEA, SEB, or 0.9% saline, and measured splenic T-cell-derived cytokine concentrations (viz., IL-2, IFN-γ, IL-6, and IL-4) 2 h later; animals injected with SEA were also measured for splenic concentrations of TNF-α and IL-17A. Half of the injected pregnant animals were brought to term, and their offspring were tested on a series of behavioral tasks starting at six weeks of age (postnatal day 42 [P42]). These tasks included social interaction, the elevated plus maze (EPM), an open field and object recognition (OR) task, prepulse inhibition (PPI) of sensorimotor gating, and the Morris water maze (MWM). Results showed that SEA and SEB induced significant concentrations of all measured cytokines, and in particular IFN-γ, although cytokine responses were greater following SEA exposure. In addition, pregnancy induced an inhibitory effect on cytokine production. Behavioral results showed distinct phenotypes among offspring from SEA- or SEB-injected mothers, very likely due to differences in the magnitude of cytokines generated in response to each toxin. Offspring from SEA-injected mothers displayed modest decreases in social behavior, but increased anxiety, locomotion, interest in a novel object, and short-term spatial memory, while offspring of SEB-injected mothers only exhibited increased anxiety and locomotion. There were no deficits in PPI, which was actually pronounced in SEA and SEB offspring. Overall, the novel use of SEA and SEB as prenatal immune challenges elicited distinct behavioral profiles in the offspring that both mirrors and diverges from previous models of maternal immune activation in important ways. We conclude that superantigen-induced T-cell-mediated maternal immune activation is a valid and valuable model for studying and expanding our understanding of the effects of prenatal immune challenge on neurodevelopmental and behavioral alterations in offspring. Published by Elsevier Inc.

An intercomparison of three remote sensing-based energy balance models using large aperture scintillometer measurements over a wheat-corn production region

USDA-ARS?s Scientific Manuscript database

This paper compares three remote sensing-based models for estimating evapotranspiration (ET), namely the Surface Energy Balance System (SEBS), the Two-Source Energy Balance (TSEB) model, and the surface Temperature-Vegetation index Triangle (TVT). The models used as input MODIS/TERRA products and gr...

Estimating surface fluxes over middle and upper streams of the Heihe River Basin with ASTER imagery

NASA Astrophysics Data System (ADS)

Ma, W.; Ma, Y.; Hu, Z.; Su, Z.; Wang, J.; Ishikawa, H.

2011-05-01

Land surface heat fluxes are essential measures of the strengths of land-atmosphere interactions involving energy, heat and water. Correct parameterization of these fluxes in climate models is critical. Despite their importance, state-of-the-art observation techniques cannot provide representative areal averages of these fluxes comparable to the model grid. Alternative methods of estimation are thus required. These alternative approaches use (satellite) observables of the land surface conditions. In this study, the Surface Energy Balance System (SEBS) algorithm was evaluated in a cold and arid environment, using land surface parameters derived from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data. Field observations and estimates from SEBS were compared in terms of net radiation flux (Rn), soil heat flux (G0), sensible heat flux (H) and latent heat flux (λE) over a heterogeneous land surface. As a case study, this methodology was applied to the experimental area of the Watershed Allied Telemetry Experimental Research (WATER) project, located on the mid-to-upstream sections of the Heihe River in northwest China. ASTER data acquired between 3 May and 4 June 2008, under clear-sky conditions were used to determine the surface fluxes. Ground-based measurements of land surface heat fluxes were compared with values derived from the ASTER data. The results show that the derived surface variables and the land surface heat fluxes furnished by SEBS in different months over the study area are in good agreement with the observed land surface status under the limited cases (some cases looks poor results). So SEBS can be used to estimate turbulent heat fluxes with acceptable accuracy in areas where there is partial vegetation cover in exceptive conditions. It is very important to perform calculations using ground-based observational data for parameterization in SEBS in the future. Nevertheless, the remote-sensing results can provide improved explanations of land surface fluxes over varying land coverage at greater spatial scales.

Feasibility study on the use of groupware support for NASA source evaluation boards

NASA Technical Reports Server (NTRS)

Bishop, Peter C.; Yoes, Cissy

1991-01-01

Groupware is a class of computer based systems that support groups engaged in a common task (or goal) and that provide an interface to a shared environment. A potential application for groupware is the source evaluation board (SEB) process used in the procurement of government contracts. This study was undertaken to (1) identify parts of the SEB process which are candidates for groupware supports; and (2) identify tools which could be used to support the candidate process. Two processes of the SEB were identified as good candidates for groupware support: (1) document generation - a coordination and communication process required to present and document the findings of an SEB; and (2) group decision making - a highly analytical and integrative decision process requiring a clear and supportable outcome.

Bone marrow - mesenchymal stem cells impact on the U937 cells in the presence of staphylococcal enterotoxin B (SEB).

PubMed

Ejtehadifar, Mostafa; Halabian, Raheleh; Ghazavi, Ali; Khansarinejad, Behzad; Mosayebi, Ghasem; Imani Fooladi, Abbas Ali

2018-04-14

The growing resistance against conventional chemotherapy in acute myeloid leukemia (AML) is a noticeable clinical concern. Therefore, many researchers are looking for novel substances to overcome drug resistance in cancer. Staphylococcal enterotoxin B (SEB) is a superantigen (SAg) and a promising compound which has lethal effects on malignant cells. In this unprecedented study, SEB was used against U937 cells in a co-culture system in the presence of human bone marrow-mesenchymal stem cells (hBM-MSCs). The effects of hBM-MSCs on the proliferation and survival of U937 cell line with SEB was assessed using MTT assay and AnnexinV/PI flowcytometry, respectively. Moreover, the expression of IL-6, IL-10, TGF-β, and inhibitor of nuclear factor kappa-B kinase (IKKb) was evaluated by real-time PCR technique. The same experiments were also carried out using hBM-MSCs-conditioned medium (hBM-MSCs-CM). The results showed that SEB reduced the proliferation and survival of U937 cell line, but hBM-MSCs or hBM-MSCs-CM suppressed the effects of SEB. Furthermore, real-timePCR demonstrated that SEB could decrease the expression of IL-6, IL-10, and TGF-β in hBM-MSCs (P < .05), while the production of IKKb was increased in comparison with the control group. These findings help us to have a broader understanding ofthe usage of SEB in the treatment of haematological malignancies, especially if it is targeted against hBM-MSCs to disrupt their supportive effects on malignant cells. © 2018 John Wiley & Sons Australia, Ltd.

A novel IgY-Aptamer hybrid system for cost-effective detection of SEB and its evaluation on food and clinical samples

PubMed Central

Mudili, Venkataramana; Makam, Shivakiran S.; Sundararaj, Naveen; Siddaiah, Chandranayaka; Gupta, Vijai Kumar; Rao, Putcha V. Lakshmana

2015-01-01

In the present study, we introduce a novel hybrid sandwich-ALISA employing chicken IgY and ssDNA aptamers for the detection of staphylococcal enterotoxin B (SEB). Cloning, expression and purification of the full length recombinant SEB was carried out. Anti-SEB IgY antibodies generated by immunizing white leg-horn chickens with purified recombinant SEB protein and were purified from the immunized egg yolk. Simultaneously, ssDNA aptamers specific to the toxin were prepared by SELEX method on microtiter well plates. The sensitivity levels of both probe molecules i.e., IgY and ssDNA aptamers were evaluated. We observed that the aptamer at 250 ngmL−1 concentration could detect the target antigen at 50 ngmL−1 and the IgY antibodies at 250 ngmL−1, could able to detect 100 ngmL−1 antigen. We further combined both the probes to prepare a hybrid sandwich aptamer linked immune sorbent assay (ALISA) wherein the IgY as capturing molecule and biotinylated aptamer as revealing probe. Limit of detection (LOD) for the developed method was determined as 50 ngmL−1. Further, developed method was evaluated with artificially SEB spiked milk and natural samples and obtained results were validated with PCR. In conclusion, developed ALISA method may provide cost-effective and robust detection of SEB from food and environmental samples. PMID:26477645

Single event burnout sensitivity of embedded field effect transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koga, R.; Crain, S.H.; Crawford, K.B.

Observations of single event burnout (SEB) in embedded field effect transistors are reported. Both SEB and other single event effects are presented for several pulse width modulation and high frequency devices. The microscope has been employed to locate and to investigate the damaged areas. A model of the damage mechanism based on the results so obtained is described.

Single event burnout sensitivity of embedded field effect transistors

NASA Astrophysics Data System (ADS)

Koga, R.; Crain, S. H.; Crawford, K. B.; Yu, P.; Gordon, M. J.

1999-12-01

Observations of single event burnout (SEB) in embedded field effect transistors are reported. Both SEB and other single event effects are presented for several pulse width modulation and high frequency devices. The microscope has been employed to locate and to investigate the damaged areas. A model of the damage mechanism based on the results so obtained is described.

Operating The Central Process Systems At Glenn Research Center

NASA Technical Reports Server (NTRS)

Weiler, Carly P.

2004-01-01

As a research facility, the Glenn Research Center (GRC) trusts and expects all the systems, controlling their facilities to run properly and efficiently in order for their research and operations to occur proficiently and on time. While there are many systems necessary for the operations at GRC, one of those most vital systems is the Central Process Systems (CPS). The CPS controls operations used by GRC's wind tunnels, propulsion systems lab, engine components research lab, and compressor, turbine and combustor test cells. Used widely throughout the lab, it operates equipment such as exhausters, chillers, cooling towers, compressors, dehydrators, and other such equipment. Through parameters such as pressure, temperature, speed, flow, etc., it performs its primary operations on the major systems of Electrical Dispatch (ED), Central Air Dispatch (CAD), Central Air Equipment Building (CAEB), and Engine Research Building (ERB). In order for the CPS to continue its operations at Glenn, a new contract must be awarded. Consequently, one of my primary responsibilities was assisting the Source Evaluation Board (SEB) with the process of awarding the recertification contract of the CPS. The job of the SEB was to evaluate the proposals of the contract bidders and then to present their findings to the Source Selecting Official (SSO). Before the evaluations began, the Center Director established the level of the competition. For this contract, the competition was limited to those companies classified as a small, disadvantaged business. After an industry briefing that explained to qualified companies the CPS and type of work required, each of the interested companies then submitted proposals addressing three components: Mission Suitability, Cost, and Past Performance. These proposals were based off the Statement of Work (SOW) written by the SEB. After companies submitted their proposals, the SEB reviewed all three components and then presented their results to the SSO. While the SEB does not select the company receiving the contract, they can make recommendations based on their findings to the SSO, who actually awards the contract. The SEB began work for this contract in July 2003 by writing the SOW and the selection will tentatively occur July 30, 2004. Contract awarding will take place Aug. 15. Following the awarding, the winning company has a 30-day Phase-in Period beginning Sept. 1,2004 and full performance will begin October 1.

A Dynamic Analysis of the Effects of Intelligence and Socioeconomic Background on Job-Market Success

ERIC Educational Resources Information Center

Ganzach, Yoav

2011-01-01

We compare the effects of socioeconomic background (SEB) and intelligence on wage trajectories in a dynamic growth modeling framework in a sample that had completed just 12 years of education. I show that the main difference between the two is that SEB affected wages solely by its effect on entry pay whereas intelligence affected wages primarily…

A novel air quality analysis and prediction system for São Paulo, Brazil to support decision-making

NASA Astrophysics Data System (ADS)

Hoshyaripour, Gholam Ali; Brasseur, Guy; Andrade, Maria Fatima; Gavidia-Calderón, Mario; Bouarar, Idir

2016-04-01

The extensive economic development and urbanization in southeastern Brazil (SEB) in recent decades have notably degraded the air quality with adverse impacts on human health. Since the Metropolitan Area of São Paulo (MASP) accommodates the majority of the economic growth in SEB, it overwhelmingly suffers from the air pollution. Consequently, there is a strong demand for developing ever-better assessment mechanisms to monitor the air quality and to assist the decision makers to mitigate the air pollution in MASP. Here we present the results of an air quality modeling system designed for SEB with focuses on MASP. The Weather Research and Forecast model with Chemistry (WRF-Chem) is used considering the anthropogenic, biomass-burning and biogenic emissions within a 1000×1500 km domain with resolution of 10 km. FINN and MEGAN are used for the biomass-burning and biogenic emissions, respectively. For the anthropogenic emissions we use a local bottom-up inventory for the transport sector and the HTAPv2 global inventory for all other sectors. The bottom-up inventory accounts for the traffic patterns, vehicle types and their emission factors in the area and thus could be used to evaluate the effect of changes in these parameters on air quality in MASP. The model outputs are compered to the satellite and ground-based observations for O3 and NOx. The results show that using the bottom-up or top-down inventories individually can result in a huge deviation between the predictions and observations. On the other hand, combining the inventories significantly enhances the forecast accuracy. It also provides a powerful tool to quantify the effects of traffic and vehicle emission policies on air quality in MASP.

Preliminary investigation of human serum albumin-Vβ inhibition on toxic shock syndrome induced by staphylococcus enterotoxin B in vitro and in vivo.

PubMed

Yuan, Qifeng; Li, Lin; Pian, Yaya; Hao, Huaijie; Zheng, Yuling; Zang, Yating; Jiang, Hua; Jiang, Yongqiang

2016-04-01

Staphylococcus enterotoxin B (SEB) is a superantigen that can induce massive activation of T cells with specific Vβ and inflammatory cytokine cascades, which mediate shock. To date, no SEB vaccine has been developed for preventing toxic shock syndrome (TSS). Here, we evaluated the therapeutic effect of a fusion protein human serum albumin-Vβ (HSA-Vβ) on TSS induced by SEB. Compared with Vβ, the preparation of HSA-Vβ was much easier to handle owing to its solubility. Affinity testing showed that HSA-Vβ had high affinity for SEB. In vitro results showed that HSA-Vβ could effectively inhibit interferon (IFN)-γ and tumor necrosis factor (TNF)-α secretion by human peripheral blood mononuclear cells. Moreover, in vivo, HSA-Vβ reduced IFN-γ and TNF-α levels in the serum and protected mice from SEB lethal challenge when administered simultaneously with SEB or 30 min after SEB. In summary, we simplified the preparation of Vβ by fusion with HSA, creating the HSA-Vβ protein, which effectively inhibited cytokine production and protected mice from lethal challenge with SEB. These data indicated that HSA-Vβ may represent a novel therapeutic strategy for the treatment of SEB-induced TSS. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of food-related stress conditions and loss of agr and sigB on seb promoter activity in S. aureus.

PubMed

Sihto, Henna-Maria; Stephan, Roger; Engl, Christoph; Chen, John; Johler, Sophia

2017-08-01

Staphylococcal enterotoxin B (SEB) causes staphylococcal food poisoning and is produced in up to ten times higher quantities than other major enterotoxins. While Staphylococcus aureus growth is often repressed by competing flora, the organism exhibits a decisive growth advantage under some stress conditions. So far, data on the influence of food-related stressors and regulatory mutations on seb expression is limited and largely based on laboratory strains, which were later reported to harbor mutations. Therefore, the aim of this study was to investigate the influence of stress and regulatory mutations on seb promoter activity. To this end, transcriptional fusions were created in two strains, USA300 and HG003, carrying different seb upstream sequences fused to a blaZ reporter. NaCl, nitrite, and glucose stress led to significantly decreased seb promoter activity, while lactic acid stress resulted in significantly increased seb promoter activity. Loss of agr decreased seb promoter activity and loss of sigB increased promoter activity, with the magnitude of change depending on the strain. These results demonstrate that mild stress conditions encountered during food production and preservation can induce significant changes in seb promoter activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Surface modification of poly (styrene-b-(ethylene-co-butylene)-b-styrene) elastomer and its plasma protein adsorption by QCM-D

NASA Astrophysics Data System (ADS)

Li, Rui; Jin, Jing; Sun, Yingchun

2014-05-01

Protein adsorption is a dynamic process and plays a major role in determining the hemocompatibility of biomaterials. We have obtained different poly (ethylene glycol) (PEG) graft concentrations of SEBS-g-PEG and the surface chemical compositions are confirmed by X-ray photoelectron spectroscopy (XPS). Graft concentration is defined by peak-area ratio of [C--O]/[C] on modified SEBS surface. With increasing graft concentration, water contact angles of the modified SEBS have significantly decreased. The platelet adhesion and static protein adsorption demonstrate that the hemocompatibility of copolymers films are improved effectively and SEBS-g-PEG-2 with larger graft concentration has more superior anticoagulation than that of SEBS-g-PEG-1. Moreover, we have quantitatively investigated the adsorption process of bovine serum albumin (BSA) and fibrinogen (Fib) on the surfaces of pristine SEBS and modified SEBS using quartz crystal microbalance with dissipation (QCM-D) in real time. The results indicate that the inactivated BSA on the pristine SEBS can continuously induce the subsequent Fib adsorption. The hemocompatibility of SEBS-g-PEG-2 with the graft concentration of 0.207 has excellent anti-protein property and the bio-inert BSA layer on the film can resist the subsequent Fib adsorption.

The SEB-1 Transcription Factor Binds to the STRE Motif in Neurospora crassa and Regulates a Variety of Cellular Processes Including the Stress Response and Reserve Carbohydrate Metabolism.

PubMed

Freitas, Fernanda Zanolli; Virgilio, Stela; Cupertino, Fernanda Barbosa; Kowbel, David John; Fioramonte, Mariana; Gozzo, Fabio Cesar; Glass, N Louise; Bertolini, Maria Célia

2016-05-03

When exposed to stress conditions, all cells induce mechanisms resulting in an attempt to adapt to stress that involve proteins which, once activated, trigger cell responses by modulating specific signaling pathways. In this work, using a combination of pulldown assays and mass spectrometry analyses, we identified the Neurospora crassa SEB-1 transcription factor that binds to the Stress Response Element (STRE) under heat stress. Orthologs of SEB-1 have been functionally characterized in a few filamentous fungi as being involved in stress responses; however, the molecular mechanisms mediated by this transcription factor may not be conserved. Here, we provide evidences for the involvement of N. crassa SEB-1 in multiple cellular processes, including response to heat, as well as osmotic and oxidative stress. The Δseb-1 strain displayed reduced growth under these conditions, and genes encoding stress-responsive proteins were differentially regulated in the Δseb-1 strain grown under the same conditions. In addition, the SEB-1-GFP protein translocated from the cytosol to the nucleus under heat, osmotic, and oxidative stress conditions. SEB-1 also regulates the metabolism of the reserve carbohydrates glycogen and trehalose under heat stress, suggesting an interconnection between metabolism control and this environmental condition. We demonstrated that SEB-1 binds in vivo to the promoters of genes encoding glycogen metabolism enzymes and regulates their expression. A genome-wide transcriptional profile of the Δseb-1 strain under heat stress was determined by RNA-seq, and a broad range of cellular processes was identified that suggests a role for SEB-1 as a protein interconnecting these mechanisms. Copyright © 2016 Freitas et al.

Isolation of a new ssDNA aptamer against staphylococcal enterotoxin B based on CNBr-activated sepharose-4B affinity chromatography.

PubMed

Hedayati Ch, Mojtaba; Amani, Jafar; Sedighian, Hamid; Amin, Mohsen; Salimian, Jafar; Halabian, Raheleh; Imani Fooladi, Abbas Ali

2016-09-01

Staphylococcus aureus are potent human pathogens possessing arsenal of virulence factors. Staphylococcal food poisoning (SFP) and respiratory infections mediated by staphylococcal enterotoxin B (SEB) are common clinical manifestations. Many diagnostic techniques are based on serological detection and quantification of SEB in different food and clinical samples. Aptamers are known as new therapeutic and detection tools which are available in different ssDNA, dsDNA and protein structures. In this study, we used a new set of ssDNA aptamers against SEB. The methods used included preparation of a dsDNA library using standard SEB protein as the target analyte, affinity chromatography matrix in microfuge tubes, SELEX procedures to isolate specific ssDNA-aptamer as an affinity ligand, aptamer purification using ethanol precipitation method, affinity binding assay using ELISA, aptamer cloning and specificity test. Among 12 readable sequences, three of them were selected as the most appropriate aptamer because of their affinity and specificity to SEB. This study presents a new set of ssDNA aptamer with favorable selectivity to SEB through 12 rounds of SELEX. Selected aptamers were used to detect SEB in infected serum samples. Results showed that SEB c1 aptamer (2 µg SEB/100 nM aptamer) had favorable specificity to SEB (kd  = 2.3 × 10(-11) ). In conclusion, aptamers can be considered as useful tools for detecting and evaluating SEB. The results showed that affinity chromatography was an affordable assay with acceptable accuracy to isolate sensitive and selective novel aptamers. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Highly Sensitive Colorimetric Biosensor for Staphylococcal Enterotoxin B by a Label-Free Aptamer and Gold Nanoparticles

PubMed Central

Mondal, Bhairab; Ramlal, Shylaja; Lavu, Padma S.; N, Bhavanashri; Kingston, Joseph

2018-01-01

A simple, sensitive and selective colorimetric biosensor for the detection of Staphylococcal enterotoxin B (SEB) was developed using SEB-binding aptamer (SEB2) as recognition element and unmodified gold nanoparticles (AuNPs) as colorimetric probes. The assay is based on color change from red to purple due to conformational change of aptamer in the presence of SEB, and the phenomenon of salt-induced AuNPs aggregation which could be monitored by naked eye or UV–vis spectrometer. Results showed that the AuNPs can effectively differentiate the SEB induced conformational change of the aptamer in the presence of a given high salt concentration. A linear response in the range of 50 μg/mL to 0.5 ng/mL of SEB concentration was obtained. The assay was highly specific to SEB as compared to other related toxins. The limit of detection (LOD) of SEB achieved within few minutes was 50 ng/mL visually and spectrometric method improved it to 0.5 ng/mL. Robustness of the assay was tested in artificially spiked milk samples and cross-checked using in house developed sandwich ELISA (IgY as capturing and SEB specific monoclonal as revealing antibody) and PCR. This colorimetric assay could be a suitable alternative over existing methods during biological emergencies due to its simplicity, sensitive and cost effectiveness. PMID:29487580

Effect of thermal processing during yogurt production upon the detection of staphylococcal enterotoxin B.

PubMed

Principato, Maryann; Boyle, Thomas; Njoroge, Joyce; Jones, Robert L; O'Donnell, Michael

2009-10-01

This research was conducted to examine the inherent properties of yogurt contaminated with staphylococcal enterotoxin B (SEB). Two types of yogurts were produced for this study. Type I yogurts were produced by adding SEB at the start of yogurt production, and type II yogurts were produced by adding SEB after the milk base had been boiled. Biochemical characteristics inherent to yogurt, including pH, lactic acid and acetaldehyde concentrations, were analyzed weekly for each batch beginning at a time just after production and throughout a storage period of at least 4 weeks. The presence of toxin during yogurt production did not result in any significant biochemical or physical changes in yogurt. However, we were unable to detect SEB toxin in type I yogurt using a commercially available enzyme-linked immunosorbent assay (ELISA). In contrast, SEB was easily detectable by our ELISA in type II yogurt samples. Higher levels of SEB were recovered from type II yogurt that had been stored for 1 week than from type II yogurt that had been stored for any other length of time. These results indicate that the biochemical characteristics of yogurt did not change significantly (relative to control yogurt) in the presence of either thermally processed SEB or native SEB. However, the ability to detect SEB by ELISA was dependent on whether the toxin had been processed.

Regional evapotranspiration from an image-based implementation of the Surface Temperature Initiated Closure (STIC1.2) model and its validation across an aridity gradient in the conterminous US

NASA Astrophysics Data System (ADS)

Bhattarai, Nishan; Mallick, Kaniska; Brunsell, Nathaniel A.; Sun, Ge; Jain, Meha

2018-04-01

Recent studies have highlighted the need for improved characterizations of aerodynamic conductance and temperature (gA and T0) in thermal remote-sensing-based surface energy balance (SEB) models to reduce uncertainties in regional-scale evapotranspiration (ET) mapping. By integrating radiometric surface temperature (TR) into the Penman-Monteith (PM) equation and finding analytical solutions of gA and T0, this need was recently addressed by the Surface Temperature Initiated Closure (STIC) model. However, previous implementations of STIC were confined to the ecosystem-scale using flux tower observations of infrared temperature. This study demonstrates the first regional-scale implementation of the most recent version of the STIC model (STIC1.2) that integrates the Moderate Resolution Imaging Spectroradiometer (MODIS) derived TR and ancillary land surface variables in conjunction with NLDAS (North American Land Data Assimilation System) atmospheric variables into a combined structure of the PM and Shuttleworth-Wallace (SW) framework for estimating ET at 1 km × 1 km spatial resolution. Evaluation of STIC1.2 at 13 core AmeriFlux sites covering a broad spectrum of climates and biomes across an aridity gradient in the conterminous US suggests that STIC1.2 can provide spatially explicit ET maps with reliable accuracies from dry to wet extremes. When observed ET from one wet, one dry, and one normal precipitation year from all sites were combined, STIC1.2 explained 66 % of the variability in observed 8-day cumulative ET with a root mean square error (RMSE) of 7.4 mm/8-day, mean absolute error (MAE) of 5 mm/8-day, and percent bias (PBIAS) of -4 %. These error statistics showed relatively better accuracies than a widely used but previous version of the SEB-based Surface Energy Balance System (SEBS) model, which utilized a simple NDVI-based parameterization of surface roughness (zOM), and the PM-based MOD16 ET. SEBS was found to overestimate (PBIAS = 28 %) and MOD16 was found to underestimate ET (PBIAS = -26 %). The performance of STIC1.2 was better in forest and grassland ecosystems as compared to cropland (20 % underestimation) and woody savanna (40 % overestimation). Model inter-comparison suggested that ET differences between the models are robustly correlated with gA and associated roughness length estimation uncertainties which are intrinsically connected to TR uncertainties, vapor pressure deficit (DA), and vegetation cover. A consistent performance of STIC1.2 in a broad range of hydrological and biome categories, as well as the capacity to capture spatio-temporal ET signatures across an aridity gradient, points to the potential for this simplified analytical model for near-real-time ET mapping from regional to continental scales.

An Updated Perspective of Single Event Gate Rupture and Single Event Burnout in Power MOSFETs

NASA Astrophysics Data System (ADS)

Titus, Jeffrey L.

2013-06-01

Studies over the past 25 years have shown that heavy ions can trigger catastrophic failure modes in power MOSFETs [e.g., single-event gate rupture (SEGR) and single-event burnout (SEB)]. In 1996, two papers were published in a special issue of the IEEE Transaction on Nuclear Science [Johnson, Palau, Dachs, Galloway and Schrimpf, “A Review of the Techniques Used for Modeling Single-Event Effects in Power MOSFETs,” IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 546-560, April. 1996], [Titus and Wheatley, “Experimental Studies of Single-Event Gate Rupture and Burnout in Vertical Power MOSFETs,” IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 533-545, Apr. 1996]. Those two papers continue to provide excellent information and references with regard to SEB and SEGR in vertical planar MOSFETs. This paper provides updated references/information and provides an updated perspective of SEB and SEGR in vertical planar MOSFETs as well as provides references/information to other device types that exhibit SEB and SEGR effects.

Fluorescent Pressure Response of Protein-Nanocluster Polymer Composites

DTIC Science & Technology

2016-05-01

composites as pressure sensitive indicators of brain damage. The PNC composites are made up of protein coated gold nanoclusters and a styrene- ethylene ...styrene- ethylene /butylene-styrene (SEBS):mineral oil composites that were developed as a brain tissue surrogate at ARL. Finally, we would like to...allowing us to use solid samples and create a model for brain damage. To this end, we used styrene- ethylene /butylene-styrene (SEBS) as the matrix to

Discussions On Worst-Case Test Condition For Single Event Burnout

NASA Astrophysics Data System (ADS)

Liu, Sandra; Zafrani, Max; Sherman, Phillip

2011-10-01

This paper discusses the failure characteristics of single- event burnout (SEB) on power MOSFETs based on analyzing the quasi-stationary avalanche simulation curves. The analyses show the worst-case test condition for SEB would be using the ion that has the highest mass that would result in the highest transient current due to charge deposition and displacement damage. The analyses also show it is possible to build power MOSFETs that will not exhibit SEB even when tested with the heaviest ion, which have been verified by heavy ion test data on SEB sensitive and SEB immune devices.

Cascade of chromosomal rearrangements caused by a heterogeneous T-DNA integration supports the double-stranded break repair model for T-DNA integration.

PubMed

Hu, Yufei; Chen, Zhiyu; Zhuang, Chuxiong; Huang, Jilei

2017-06-01

Transferred DNA (T-DNA) from Agrobacterium tumefaciens can be integrated into the plant genome. The double-stranded break repair (DSBR) pathway is a major model for T-DNA integration. From this model, we expect that two ends of a T-DNA molecule would invade into a single DNA double-stranded break (DSB) or independent DSBs in the plant genome. We call the later phenomenon a heterogeneous T-DNA integration, which has never been observed. In this work, we demonstrated it in an Arabidopsis T-DNA insertion mutant seb19. To resolve the chromosomal structural changes caused by T-DNA integration at both the nucleotide and chromosome levels, we performed inverse PCR, genome resequencing, fluorescence in situ hybridization and linkage analysis. We found, in seb19, a single T-DNA connected two different chromosomal loci and caused complex chromosomal rearrangements. The specific break-junction pattern in seb19 is consistent with the result of heterogeneous T-DNA integration but not of recombination between two T-DNA insertions. We demonstrated that, in seb19, heterogeneous T-DNA integration evoked a cascade of incorrect repair of seven DSBs on chromosomes 4 and 5, and then produced translocation, inversion, duplication and deletion. Heterogeneous T-DNA integration supports the DSBR model and suggests that two ends of a T-DNA molecule could be integrated into the plant genome independently. Our results also show a new origin of chromosomal abnormalities. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

Influence of processing sequence on the tribological properties of VGCF-X/PA6/SEBS composites

NASA Astrophysics Data System (ADS)

Osada, Yu; Nishitani, Yosuke; Kitano, Takeshi

2016-03-01

In order to develop the new tribomaterials for mechanical sliding parts with sufficient balance of mechanical and tribological properties, we investigated the influence of processing sequence on the tribological properties of the ternary nanocomposites: the polymer blends of polyamide 6 (PA6) and styrene-ethylene/butylene-styrene copolymer (SEBS) filled with vapor grown carbon fiber (VGCF-X), which is one of carbon nanofiber (CNF) and has 15nm diameter and 3μm length. Five different processing sequences: (1) VGCF-X, PA6 and SEBS were mixed simultaneously (Process A), (2) Re-mixing (Second compounding) of the materials prepared by Process A (Process AR),(3) SEBS was blended with PA6 (PA6/SEBS blends) and then these blends were mixed with VGCF-X (Process B), (4) VGCF-X was mixed with PA6 (VGCF-X/PA6 composites) and then these composites were blended with SEBS (Process C), and (5) VGCF-X were mixed with SEBS (VGCF-X/SEBS composites) and then these composites were blended with PA6 (Process D) were attempted for preparing of the ternary nanocomposites (VGCF-X/PA6/SEBS composites). These ternary polymer nanocomposites were extruded by a twin screw extruder and injection-molded. Their tribological properties were evaluated by using a ring-on-plate type sliding wear tester under dry condition. The tribological properties such as the frictional coefficient and the specific wear rate were influenced by the processing sequence. These results may be attributed to the change of internal structure formation, which is a dispersibility of SEBS particle and VGCF-X in ternary nanocomposites (VGCF-X/PA6/SEBS) by different processing sequences. In particular, the processing sequences of AR, B and D, which are those of re-mixing of VGCF-X, have a good dispersibility of VGCF-X for the improvement of tribological properties.

3D Thermal and Mechanical Analysis of a Single Event Burnout

NASA Astrophysics Data System (ADS)

Peretti, Gabriela; Demarco, Gustavo; Romero, Eduardo; Tais, Carlos

2015-08-01

This paper presents a study related to thermal and mechanical behavior of power DMOS transistors during a Single Event Burnout (SEB) process. We use a cylindrical heat generation region for emulating the thermal and mechanical phenomena related to the SEB. In this way, it is avoided the complexity of the mathematical treatment of the ion-device interaction. This work considers locating the heat generation region in positions that are more realistic than the ones used in previous work. For performing the study, we formulate and validate a new 3D model for the transistor that maintains the computational cost at reasonable level. The resulting mathematical models are solved by means of the Finite Element Method. The simulations results show that the failure dynamics is dominated by the mechanical stress in the metal layer. Additionally, the time to failure depends on the heat source position, for a given power and dimension of the generation region. The results suggest that 3D modeling should be considered for a detailed study of thermal and mechanical effects induced by SEBs.

Colorimetric DNAzyme Biosensor for Convenience Detection of Enterotoxin B Harboring Staphylococcus aureus from Food Samples.

PubMed

Mondal, Bhairab; N, Bhavanashri; Ramlal, Shylaja; Kingston, Joseph

2018-02-14

In the present study, a colorimetric DNAzymes biosensor strategy was devised in combination with immunomagnetic separation for rapid and easy detection of enterotoxin B harboring Staphylococcus aureus from food and clinical samples. The method employs immunocapture of S. aureus and amplification of seb gene by DNAzyme complementary sequence integrated forward primer and with specific reverse primer. The DNAzyme sequence integrated dsDNA PCR products when treated with hemin and TMB (3,3',5,5'-tetramethylbenzidine) in the presence of H 2 O 2 produce colorimetric signal. A linear relationship of optical signal with the initial template of seb was obtained which could be monitored by visually or spectrophotrometrically for qualitative and quantitative detection. The limit of detection for the assay was approximately 10 2 CFU/mL of seb gene harboring target. This method is convenient compared to gel based and ELISA systems. Further, spiking studies and analysis on natural samples emphasized the robustness and applicability of developed method. Altogether, the established assay could be a reliable alternative, low-cost, viable detection tool for the routine investigation of seb from food and clinical sources.

Biodegradable and biocompatible poly(DL-lactide-co-glycolide) microspheres as an adjuvant for staphylococcal enterotoxin B toxoid which enhances the level of toxin-neutralizing antibodies.

PubMed Central

Eldridge, J H; Staas, J K; Meulbroek, J A; Tice, T R; Gilley, R M

1991-01-01

Microspheres composed of biocompatible, biodegradable poly(DL-lactide-co-glycolide) (DL-PLG) and staphylococcal enterotoxin B (SEB) toxoid were evaluated as a vaccine delivery system when subcutaneously injected into mice. As measured by circulating immunoglobulin G (IgG) antitoxin titers, the delivery of SEB toxoid via DL-PLG microspheres, 1 to 10 microns in diameter, induced an immune response which was approximately 500 times that seen with nonencapsulated toxoid. The kinetics, magnitude, and duration of the antitoxin response induced with microencapsulated toxoid were similar to those obtained when an equal toxoid dose was administered as an emulsion with complete Freund adjuvant. However, the microspheres did not induce the inflammation and granulomata formation seen with complete Freund adjuvant. The adjuvant activity of the microspheres was not dependent on the superantigenicity of SEB toxin and was equally effective at potentiating circulating IgG antitrinitrophenyl levels in response to microencapsulated trinitrophenyl-keyhole limpet hemocyanin. Empty DL-PLG microspheres were not mitogenic, and SEB toxoid injected as a mixture with empty DL-PLG microspheres was no more effective as an immunogen than toxoid alone. Antigen-containing microspheres 1 to 10 microns in diameter exhibited stronger adjuvant activity than those greater than 10 microns, which correlated with the delivery of the 1- to 10-microns, but not the greater than 10-microns, microspheres into the draining lymph nodes within macrophages. The antibody response induced through immunization with microencapsulated SEB toxoid was protective against the weight loss and splenic V beta 8+ T-cell expansion induced by intravenous toxin administration. These results show that DL-PLG microsphere vaccine delivery systems, which are composed of pharmaceutically acceptable components, possess a strong adjuvant activity for their encapsulated antigens. PMID:1879922

Ultrasensitive electrochemical immunoassay of staphylococcal enterotoxin B in food using enzyme-nanosilica-doped carbon nanotubes for signal amplification.

PubMed

Tang, Dianping; Tang, Juan; Su, Biling; Chen, Guonan

2010-10-27

A new sandwich-type electrochemical immunoassay for ultrasensitive detection of staphylococcal enterotoxin B (SEB) in food was developed using horseradish peroxidase-nanosilica-doped multiwalled carbon nanotubes (HRPSiCNTs) for signal amplification. Rabbit polyclonal anti-SEB antibodies immobilized on the screen-printed carbon electrode (SPCE) and covalently bound to the HRPSiCNTs were used as capture antibodies and detection antibodies, respectively. In the presence of SEB analyte, the sandwich-type immunocomplex could be formed between the immobilized anti-SEB on the SPCE and anti-SEB-labeled HRPSiCNTs, and the carried HRP could catalyze the electrochemical reduction of H2O2 with the help of thionine. The high content of HRP in the HRPSiCNTs could greatly amplify the electrochemical signal. Under optimal conditions, the reduction current increased with the increase of SEB in the sample, and exhibited a dynamic range of 0.05-15 ng/mL with a low detection limit (LOD) of 10 pg/mL SEB (at 3σ). Intra- and interassay coefficients of variation were below 10%. In addition, the assay was evaluated with SEB spiked samples including watermelon juice, soymilk, apple juice, and pork food, receiving excellent correlation with results from commercially available enzyme-linked immunosorbent assay (ELISA).

Probing the SEB Sensitive Depth of a Power MOSFET Using a Two-Photon Absorption Laser Method

NASA Technical Reports Server (NTRS)

Lauenstein, Jean-Marie; Liu, Sandra; Titus, Jeffrey L.; McMorrow, Dale; Casey, Megan C.; Buchner, Stephen P.; Warner, Jeffrey; Phan, Anthony M.; Topper, Alyson D.; Kim, Hak S.;

The staphylococcal enterotoxin (SE) family: SEB and siblings.

PubMed

Krakauer, Teresa; Stiles, Bradley G

2013-11-15

Staphylococcus aureus plays an important role in numerous human cases of food poisoning, soft tissue, and bone infections, as well as potentially lethal toxic shock. This common bacterium synthesizes various virulence factors that include staphylococcal enterotoxins (SEs). These protein toxins bind directly to major histocompatibility complex class II on antigen-presenting cells and specific Vβ regions of T-cell receptors, resulting in potentially life-threatening stimulation of the immune system. Picomolar concentrations of SEs ultimately elicit proinflammatory cytokines that can induce fever, hypotension, multi-organ failure, and lethal shock. Various in vitro and in vivo models have provided important tools for studying the biological effects of, as well as potential vaccines/therapeutics against, the SEs. This review succinctly presents known physical and biological properties of the SEs, including various intervention strategies. In particular, SEB will often be portrayed as per biodefense concerns dating back to the 1960s.

Natural killer T cells are required for the development of a superantigen-driven T helper type 2 immune response in mice

PubMed Central

Nomizo, Auro; Postol, Edilberto; de Alencar, Raquel; Cardillo, Fabíola; Mengel, José

2005-01-01

We show, here, that one single injection or weekly injections of staphylococcal enterotoxin B (SEB), starting in 1-day-old newborn mice, induced a powerful immune response with a T helper type 2 (Th2) pattern, as judged by the isotype and cytokine profile, with the production of large amounts of SEB-specific immunoglobulin G1 (IgG1), detectable levels of SEB-specific IgE and increased production of interleukin-4 by spleen cells. These protocols also induced an increase in the levels of total IgE in the serum. Memory of SEB was transferred to secondary recipients by using total spleen cells from primed animals. The secondary humoral response in transferred mice was diminished if spleen cells from SEB-treated mice were previously depleted of CD3+ or Vβ8+ T cells or NK1.1+ cells. In vivo depletion of NK1.1+ cells in adult mice resulted in a marked reduction in the SEB-specific antibody response in both the primary and secondary immune responses. Additionally, purified NK1.1+ T cells were able to perform SEB-specific helper B-cell actions in vitro and in vivo. These results suggest that NK1.1+ T cells are required for the full development of humoral immunological memory, whilst making neonatal tolerance to SEB unachievable. PMID:16162272

Antimicrobial activities of secondary metabolites and phylogenetic study of sponge endosymbiotic bacteria, Bacillus sp. at Agatti Island, Lakshadweep Archipelago.

PubMed

Mohan, Gopi; Thipparamalai Thangappanpillai, Ajith Kumar; Ramasamy, Balagurunathan

2016-09-01

Twenty-one species of sponges were recorded under the class of Demospongiae and Calcareous sponges of which 19 species were new to Agatti reef. A total of 113 Sponge endosymbiotic bacterial strains were isolated from twenty-one species of sponges and screened for antimicrobial activity. Five bacterial strains of sponge endosymbiotic bacteria (SEB) namely SEB32, SEB33, SEB36, SEB43 and SEB51 showed antimicrobial activity against virulent marine fish pathogens such as Vibrio alginolyticus , Vibrio vulnificus , Vibrio parahaemolyticus , Aeromonas salmonicida , Flavobacterium sp., Edwardsiella sp., Proteus mirabilis and Citrobacter brackii . The secondary metabolites produced by SEB32 from sponge Dysidea fragilis (Montagu, 1818) [48] was selected with broad range of antibacterial activity and subjected for production, characterization by series of chromatography techniques and spectroscopic methods. Based on the results of FT-IR and mass spectrometry, the active molecule was tentatively predicted as "Pyrrol" and the structure is Pyrrolo[1,2 -a ]pyrazine-1,4-dione, hexahydro- with molecular formula of C7H10N2O2. The LC 50 of active molecule was 31 μg/ml and molecular weight of the metabolites was 154. The potential strain SEB32 was identified by gene sequence (GenBank Accession number JX985748) and identified as Bacillus sp. from GenBank database.

Determination of enterotoxigenic and methicillin resistant Staphylococcus aureus in ice cream.

PubMed

Gücükoğlu, Ali; Çadirci, Özgür; Terzi, Göknur; Kevenk, T Onur; Alişarli, Mustafa

2013-05-01

The aim of this study was to determine the prevalence of enterotoxigenic and methicillin-resistant Staphylococcus aureus in ice creams. After culture-based identification of isolates, the presence of 16S rRNA and nuc was confirmed by mPCR. S. aureus was identified in 18 of 56 fruity (32.1%), 4 of 32 vanilla (12.5%), and 1 of 12 chocolate (8.3%) ice creams. S. aureus was identified as 38 isolates in 23 ice cream samples by culture-based techniques, but only 35 isolates were confirmed by PCR as S. aureus. To determine the enterotoxigenic properties of PCR-confirmed S. aureus isolates, a toxin detection kit was used (SET RPLA®). Of the 12 enterotoxigenic S. aureus isolates, 9 SEB (75%), 1 SED (8.3%), 1 SEB+SED (8.3%), and 1 SEA+SEB+SED (8.3%) expressing isolates were found. The presence of enterotoxin genes (sea, seb, sed) was identified in 13 (37.1%) out of 35 isolates by the mPCR technique. In the ice cream isolates, the sea, seb, and sed genes were detected: 1 sea (7.6%), 9 seb (69.2%), 1 sed (7.6%), 1 seb+sed (7.6%), and 1 sea+seb+sed (7.6%), respectively. The sec gene was not detected in any of these isolates. One of the 35 (2.8%) S. aureus strain was mecA positive. © 2013 Institute of Food Technologists®

Natural indoles, indole-3-carbinol and 3,3′-diindolymethane, inhibit T cell activation by staphylococcal enterotoxin B through epigenetic regulation involving HDAC expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Busbee, Philip B.; Nagarkatti, Mitzi; Nagarkatti, Prakash S., E-mail: prakash@mailbox.sc.edu

2014-01-01

Staphylococcal enterotoxin B (SEB) is a potent exotoxin produced by the Staphylococcus aureus. This toxin is classified as a superantigen because of its ability to directly bind with MHC-II class molecules followed by activation of a large proportion of T cells bearing specific Vβ-T cell receptors. Commonly associated with classic food poisoning, SEB has also been shown to induce toxic shock syndrome, and is also considered to be a potential biological warfare agent because it is easily aerosolized. In the present study, we assessed the ability of indole-3-carbinol (I3C) and one of its byproducts, 3,3′-diindolylmethane (DIM), found in cruciferous vegetables,more » to counteract the effects of SEB-induced activation of T cells in mice. Both I3C and DIM were found to decrease the activation, proliferation, and cytokine production by SEB-activated Vβ8{sup +} T cells in vitro and in vivo. Interestingly, inhibitors of histone deacetylase class I (HDAC-I), but not class II (HDAC-II), showed significant decrease in SEB-induced T cell activation and cytokine production, thereby suggesting that epigenetic modulation plays a critical role in the regulation of SEB-induced inflammation. In addition, I3C and DIM caused a decrease in HDAC-I but not HDAC-II in SEB-activated T cells, thereby suggesting that I3C and DIM may inhibit SEB-mediated T cell activation by acting as HDAC-I inhibitors. These studies not only suggest for the first time that plant-derived indoles are potent suppressors of SEB-induced T cell activation and cytokine storm but also that they may mediate these effects by acting as HDAC inhibitors. - Highlights: • I3C and DIM reduce SEB-induced T cell activation and inflammatory cytokines. • Inhibiting class I HDACs reduces T cell activation and inflammatory cytokines. • Inhibiting class II HDACs increases T cell activation and inflammatory cytokines. • I3C and DIM selectively reduce mRNA expression of class I HDACs. • Novel use and mechanism to counteract SEB with I3C and DIM.« less

Selection of staphylococcal enterotoxin B (SEB)-binding peptide using phage display technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soykut, Esra Acar; Dudak, Fahriye Ceyda; Boyaci, Ismail Hakki

In this study, peptides were selected to recognize staphylococcal enterotoxin B (SEB) which cause food intoxication and can be used as a biological war agent. By using commercial M13 phage library, single plaque isolation of 38 phages was done and binding affinities were investigated with phage-ELISA. The specificities of the selected phage clones showing high affinity to SEB were checked by using different protein molecules which can be found in food samples. Furthermore, the affinities of three selected phage clones were determined by using surface plasmon resonance (SPR) sensors. Sequence analysis was realized for three peptides showing high binding affinitymore » to SEB and WWRPLTPESPPA, MNLHDYHRLFWY, and QHPQINQTLYRM amino acid sequences were obtained. The peptide sequence with highest affinity to SEB was synthesized with solid phase peptide synthesis technique and thermodynamic constants of the peptide-SEB interaction were determined by using isothermal titration calorimetry (ITC) and compared with those of antibody-SEB interaction. The binding constant of the peptide was determined as 4.2 {+-} 0.7 x 10{sup 5} M{sup -1} which indicates a strong binding close to that of antibody.« less

Processes Affecting the Annual Surface Energy Budget at High-Latitude Terrestrial Sites

NASA Astrophysics Data System (ADS)

Persson, P. O. G.; Stone, R. S.; Grachev, A.; Matrosova, L.

2012-04-01

Instrumentation at four Study of Environmental Arctic Change (SEARCH) sites (Barrow, Eureka, Alert, and Tiksi) have been enhanced in the past 6 years, including during the 2007-2008 IPY. Data from these sites are used to investigate the annual cycle of the surface energy budget (SEB), its coupling to atmospheric processes, and for Alert, its interannual variability. The comprehensive data sets are useful for showing interactions between the atmosphere, surface, and soil at high temporal resolution throughout the annual cycle. Processes that govern the SEB variability at each site are identified, and their impacts on the SEB are quantified. For example, mesoscale modulation of the SEB caused by forcing from the local terrain (downslope wind events) and coastlines (sea and land breezes) are significant at Alert and Eureka, with these processes affecting both radiative, turbulent, and ground heat flux terms in the SEB. Sub-seasonal and interannual variations in atmospheric processes and SEB impact soil thermal structures, such as the depth and timing of the summer active layer. These analyses provide an improved understanding of the processes producing changes in surface and soil temperature, linking them through the SEB as affected by atmospheric processes.

Label-Free Toxin Detection by Means of Time-Resolved Electrochemical Impedance Spectroscopy

PubMed Central

Chai, Changhoon; Takhistov, Paul

2010-01-01

The real-time detection of trace concentrations of biological toxins requires significant improvement of the detection methods from those reported in the literature. To develop a highly sensitive and selective detection device it is necessary to determine the optimal measuring conditions for the electrochemical sensor in three domains: time, frequency and polarization potential. In this work we utilized a time-resolved electrochemical impedance spectroscopy for the detection of trace concentrations of Staphylococcus enterotoxin B (SEB). An anti-SEB antibody has been attached to the nano-porous aluminum surface using 3-aminopropyltriethoxysilane/glutaraldehyde coupling system. This immobilization method allows fabrication of a highly reproducible and stable sensing device. Using developed immobilization procedure and optimized detection regime, it is possible to determine the presence of SEB at the levels as low as 10 pg/mL in 15 minutes. PMID:22315560

Leaf-Encapsulated Vaccines: Agroinfiltration and Transient Expression of the Antigen Staphylococcal Endotoxin B in Radish Leaves

PubMed Central

Liu, Pei-Feng; Wang, Yanhan; Ulrich, Robert G.; Simmons, Christopher W.; VanderGheynst, Jean S.; Gallo, Richard L.

2018-01-01

Transgene introgression is a major concern associated with transgenic plant-based vaccines. Agroinfiltration can be used to selectively transform nonreproductive organs and avoid introgression. Here, we introduce a new vaccine modality in which Staphylococcal enterotoxin B (SEB) genes are agroinfiltrated into radishes (Raphanw sativus L.), resulting in transient expression and accumulation of SEB in planta. This approach can simultaneously express multiple antigens in a single leaf. Furthermore, the potential of high-throughput vaccine production was demonstrated by simultaneously agroinfiltrating multiple radish leaves using a multichannel pipette. The expression of SEB was detectable in two leaf cell types (epidermal and guard cells) in agroinfiltrated leaves. ICR mice intranasally immunized with homogenized leaves agroinfiltrated with SEB elicited detectable antibody to SEB and displayed protection against SEB-induced interferon-gamma (IFN-γ) production. The concept of encapsulating antigens in leaves rather than purifying them for immunization may facilitate rapid vaccine production during an epidemic disease. PMID:29577048

Chinese elders' self-image and their perceived peer-image: possibility of self-enhancement bias.

PubMed

Bai, Xue; Chow, Nelson

2013-01-01

Decades of research with Western participants has documented that there is a pervasive motivation for people to view themselves as better off than others while evidence for the existence of such self-enhancement bias (SEB) among East Asians varies considerably across studies. Considering the traditional culture of Confucius on modesty, the present study hypothesizes that there should be no significant SEB among Chinese elders. Structured face-to-face interviews were conducted with 445 older people in China-Wuhan, in which the revised Chinese version of Image of Aging Scale (IAS-C) was filled out. SEB was calculated by subtracting participants' ratings of "Peer-Image" (P) from their ratings of Self-Image (S). However, inconsistent with our hypothesis, a significant SEB was observed among the Chinese older participants and significant differences in the magnitude of SEB were discerned among older people in different characteristic groups. Possible explanations were further provided for the mismatch between Chinese values and the existence of SEB.

Mechanisms Mediating Enhanced Neutralization Efficacy of Staphylococcal Enterotoxin B by Combinations of Monoclonal Antibodies*

PubMed Central

Dutta, Kaushik; Varshney, Avanish K.; Franklin, Matthew C.; Goger, Michael; Wang, Xiaobo; Fries, Bettina C.

2015-01-01

Staphylococcal enterotoxin B (SEB) is a superantigen that cross-links the major histocompatibility complex class II and specific V-β chains of the T-cell receptor, thus forming a ternary complex. Developing neutralizing mAb to disrupt the ternary complex and abrogate the resulting toxicity is a major therapeutic challenge because SEB is effective at very low concentrations. We show that combining two SEB-specific mAbs enhances their efficacy, even though one of the two mAbs by itself has no effect on neutralization. Crystallography was employed for fine-mapping conformational epitopes in binary and ternary complexes between SEB and Fab fragments. NMR spectroscopy was used to validate and identify subtle allosteric changes induced by mAbs binding to SEB. The mapping of epitopes established that a combination of different mAbs can enhance efficacy of mAb-mediated protection from SEB induced lethal shock by two different mechanisms: one mAb mixture promoted clearance of the toxin both in vitro and in vivo by FcR-mediated cross-linking and clearance, whereas the other mAb mixture induced subtle allosteric conformational changes in SEB that perturbed formation of the SEB·T-cell receptor·major histocompatibility complex class II trimer. Finally structural information accurately predicted mAb binding to other superantigens that share conformational epitopes with SEB. Fine mapping of conformational epitopes is a powerful tool to establish the mechanism and optimize the action of synergistic mAb combinations. PMID:25572397

Mechanisms mediating enhanced neutralization efficacy of Staphylococcal enterotoxin B by combinations of monoclonal antibodies

DOE PAGES

Dutta, Kaushik; Varshney, Avanish K.; Franklin, Matthew C.; ...

2015-01-08

Staphylococcal enterotoxin B (SEB) is a superantigen that cross-links the major histocompatibility complex class II and specific V-β chains of the T-cell receptor, thus forming a ternary complex. Developing neutralizing mAb to disrupt the ternary complex and abrogate the resulting toxicity is a major therapeutic challenge because SEB is effective at very low concentrations. We show that combining two SEB-specific mAbs enhances their efficacy, even though one of the two mAbs by itself has no effect on neutralization. Crystallography was employed for fine-mapping conformational epitopes in binary and ternary complexes between SEB and Fab fragments. NMR spectroscopy was used tomore » validate and identify subtle allosteric changes induced by mAbs binding to SEB. The mapping of epitopes established that a combination of different mAbs can enhance efficacy of mAb-mediated protection from SEB induced lethal shock by two different mechanisms: one mAb mixture promoted clearance of the toxin both in vitro and in vivo by FcR-mediated cross-linking and clearance, whereas the other mAb mixture induced subtle allosteric conformational changes in SEB that perturbed formation of the SEB·T-cell receptor·major histocompatibility complex class II trimer. Lastly structural information accurately predicted mAb binding to other superantigens that share conformational epitopes with SEB. Fine mapping of conformational epitopes is a powerful tool to establish the mechanism and optimize the action of synergistic mAb combinations.« less

Eddy Correlation Flux Measurement System Handbook

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cook, D. R.

2016-01-01

The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The fluxes are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the air temperature, the water vapor density, and the CO2 concentration. The instruments used are: • a fast-response, three-dimensional (3D) wind sensor (sonic anemometer) to obtain the orthogonal wind componentsmore » and the speed of sound (SOS) (used to derive the air temperature) • an open-path infrared gas analyzer (IRGA) to obtain the water vapor density and the CO2 concentration, and • an open-path infrared gas analyzer (IRGA) to obtain methane density and methane flux at one SGP EF and at the NSA CF. The ECOR systems are deployed at the locations where other methods for surface flux measurements (e.g., energy balance Bowen ratio [EBBR] systems) are difficult to employ, primarily at the north edge of a field of crops. A Surface Energy Balance System (SEBS) has been installed collocated with each deployed ECOR system in SGP, NSA, Tropical Western Pacific (TWP), ARM Mobile Facility 1 (AMF1), and ARM Mobile Facility 2 (AMF2). The surface energy balance system consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes. The SEBS at one SGP and one NSA site also support upwelling and downwelling PAR measurements to qualify those two locations as Ameriflux sites.« less

Reliability Design for Neutron Induced Single-Event Burnout of IGBT

NASA Astrophysics Data System (ADS)

Shoji, Tomoyuki; Nishida, Shuichi; Ohnishi, Toyokazu; Fujikawa, Touma; Nose, Noboru; Hamada, Kimimori; Ishiko, Masayasu

Single-event burnout (SEB) caused by cosmic ray neutrons leads to catastrophic failures in insulated gate bipolar transistors (IGBTs). It was found experimentally that the incident neutron induced SEB failure rate increases as a function of the applied collector voltage. Moreover, the failure rate increased sharply with an increase in the applied collector voltage when the voltage exceeded a certain threshold value (SEB cutoff voltage). In this paper, transient device simulation results indicate that impact ionization at the n-drift/n+ buffer boundary is a crucially important factor in the turning-on of the parasitic pnp transistor, and eventually latch-up of the parasitic thyristor causes SEB. In addition, the device parameter dependency of the SEB cutoff voltage was analytically derived from the latch-up condition of the parasitic thyristor. As a result, it was confirmed that reducing the current gain of the parasitic transistor, such as by increasing the n-drift region thickness d was effective in increasing the SEB cutoff voltage. Furthermore, `white' neutron-irradiation experiments demonstrated that suppressing the inherent parasitic thyristor action leads to an improvement of the SEB cutoff voltage. It was confirmed that current gain optimization of the parasitic transistor is a crucial factor for establishing highly reliable design against chance failures.

Efficacy and safety data of subsequent entry biologics pertinent to nephrology practice: a systematic review.

PubMed

Marin, Judith Genevieve; Leung, Marianna; Lo, Clifford; Tsao, Nicole W; Martinusen, Daniel J

2014-01-01

Subsequent entry biologics (SEBs) may soon be a reality in Canadian nephrology practice. Understanding the worldwide experience with these agents will be valuable to Canadian clinicians. To compare the efficacy and safety data between SEBs used in nephrology practice and their reference biologic. Systematic review. Ovid MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Database of Abstracts of Review of Effects, Cochrane Central Register of Controlled Trials. Adult patients with chronic kidney disease (CKD). Our systematic review follows the process outlined by Cochrane Reviews. For efficacy data, all randomized controlled trials (RCTs), quasi-RCTs and observational trials in nephrology practice were included. For safety data, case series, case reports, review articles in nephrology practice and pharmacovigilance programs were included as well. Only epoetin SEBs trials were published in the literature. Ten studies involving three different epoetin SEBs (epoetin zeta, HX575 and epoetin theta) were included. The mean epoetin dose used did not differ significantly between the SEBs and the reference product. For epoetin zeta and epoetin theta, the mean hemoglobin levels achieved in the studies were similar between the SEBs and the reference epoetin. The HX 575 studies reported a mean absolute change in hemoglobin within the predefined equivalence margin, when compared with the reference biologic. In terms of safety data, 2 cases of pure-red-cell aplasia were linked to the subcutaneous administration of HX 575. Otherwise, the rate of adverse drug reactions was similar when epoetin SEBs were compared with the reference biologic. Our analysis is limited by the paucity of information available on SEB use in nephrology with the exception of epoetin SEBs. Methodological flaw was found in one of the epoetin zeta studies which accounted for 45% of pooled results. Little clinical difference was found between epoetin SEBs and the reference product. Although not deemed clinically important, the financial implication of a possible dose difference between epoetin zeta and reference product should be considered in pharmacoeconomic studies. Ongoing trials are expected to address the risk of pure-red-cell aplasia with HX 575.

Thermomechanical Stresses Analysis of a Single Event Burnout Process

NASA Astrophysics Data System (ADS)

Tais, Carlos E.; Romero, Eduardo; Demarco, Gustavo L.

2009-06-01

This work analyzes the thermal and mechanical effects arising in a power Diffusion Metal Oxide Semiconductor (DMOS) during a Single Event Burnout (SEB) process. For studying these effects we propose a more detailed simulation structure than the previously used by other authors, solving the mathematical models by means of the Finite Element Method. We use a cylindrical heat generation region, with 5 W, 10 W, 50 W and 100 W for emulating the thermal phenomena occurring during SEB processes, avoiding the complexity of the mathematical treatment of the ion-semiconductor interaction.

Gold nanoparticle-based enhanced chemiluminescence immunosensor for detection of Staphylococcal Enterotoxin B (SEB) in food.

PubMed

Yang, Minghui; Kostov, Yordan; Bruck, Hugh A; Rasooly, Avraham

2009-08-15

Staphylococcal enterotoxins (SEs) are major cause of foodborne diseases, so sensitive detection (<1 ng/ml) methods are needed for SE detection in food. The surface area, geometric and physical properties of gold nanoparticles make them well-suited for enhancing interactions with biological molecules in assays. To take advantage of the properties of gold nanoparticles for immunodetection, we have developed a gold nanoparticle-based enhanced chemiluminescence (ECL) immunosensor for detection of Staphylococcal Enterotoxin B (SEB) in food. Anti-SEB primary antibodies were immobilized onto a gold nanoparticle surface through physical adsorption and then the antibody-gold nanoparticle mixture was immobilized onto a polycarbonate surface. SEB was detected by a "sandwich-type" ELISA assay on the polycarbonate surface with a secondary antibody and ECL detection. The signal from ECL was read using a point-of-care detector based on a cooled charge-coupled device (CCD) sensor or a plate reader. The system was used to test for SEB in buffer and various foods (mushrooms, tomatoes, and baby food meat). The limit of detection was found to be approximately 0.01 ng/mL, which is approximately 10 times more sensitive than traditional ELISA. The gold nanoparticles were relatively easy to use for antibody immobilization because of their physical adsorption mechanism; no other reagents were required for immobilization. The use of our simple and inexpensive detector combined with the gold nanoparticle-based ECL method described here is adaptable to simplify and increase sensitivity of any immunological assay and for point-of-care diagnostics.

Gold nanoparticle-based enhanced chemiluminescence immunosensor for detection of Staphylococcal Enterotoxin B (SEB) in food

PubMed Central

Yang, Minghui; Kostov, Yordan; Bruck, Hugh A.; Rasooly, Avraham

2010-01-01

Staphylococcal enterotoxins (SEs) are major cause of foodborne diseases, so sensitive detection (<1 ng/ml) methods are needed for SE detection in food. The surface area, geometric and physical properties of gold nanoparticles make them well-suited for enhancing interactions with biological molecules in assays. To take advantage of the properties of gold nanoparticles for immunodetection, we have developed a gold nanoparticle-based enhanced chemiluminescence (ECL) immunosensor for detection of Staphylococcal Enterotoxin B (SEB) in food. Anti-SEB primary antibodies were immobilized onto a gold nanoparticle surface through physical adsorption and then the antibody–gold nanoparticle mixture was immobilized onto a polycarbonate surface. SEB was detected by a “sandwich-type” ELISA assay on the polycarbonate surface with a secondary antibody and ECL detection. The signal from ECL was read using a point-of-care detector based on a cooled charge-coupled device (CCD) sensor or a plate reader. The system was used to test for SEB in buffer and various foods (mushrooms, tomatoes, and baby food meat). The limit of detection was found to be ~0.01 ng/mL, which is ~10 times more sensitive than traditional ELISA. The gold nanoparticles were relatively easy to use for antibody immobilization because of their physical adsorption mechanism; no other reagents were required for immobilization. The use of our simple and inexpensive detector combined with the gold nanoparticle-based ECL method described here is adaptable to simplify and increase sensitivity of any immunological assay and for point-of-care diagnostics. PMID:19540011

Interferon gamma-dependent intestinal pathology contributes to the lethality in bacterial superantigen-induced toxic shock syndrome.

PubMed

Tilahun, Ashenafi Y; Holz, Marah; Wu, Tsung-Teh; David, Chella S; Rajagopalan, Govindarajan

2011-02-03

Toxic shock syndrome (TSS) caused by the superantigen exotoxins of Staphylococcus aureus and Streptococcus pyogenes is characterized by robust T cell activation, profound elevation in systemic levels of multiple cytokines, including interferon-γ (IFN-γ), followed by multiple organ dysfunction and often death. As IFN-γ possesses pro- as well as anti-inflammatory properties, we delineated its role in the pathogenesis of TSS. Antibody-mediated in vivo neutralization of IFN-γ or targeted disruption of IFN-γ gene conferred significant protection from lethal TSS in HLA-DR3 transgenic mice. Following systemic high dose SEB challenge, whereas the HLA-DR3.IFN-γ(+/+) mice became sick and succumbed to TSS, HLA-DR3.IFN-γ(-/-) mice appeared healthy and were significantly protected from SEB-induced lethality. SEB-induced systemic cytokine storm was significantly blunted in HLA-DR3.IFN-γ(-/-) transgenic mice. Serum concentrations of several cytokines (IL-4, IL-10, IL-12p40 and IL-17) and chemokines (KC, rantes, eotaxin and MCP-1) were significantly lower in HLA-DR3.IFN-γ(-/-) transgenic mice. However, SEB-induced T cell expansion in the spleens was unaffected and expansion of SEB-reactive TCR Vβ8(+) CD4(+) and CD8(+) T cells was even more pronounced in HLA-DR3.IFN-γ(-/-) transgenic mice when compared to HLA-DR3.IFN-γ(+/+) mice. A systematic histopathological examination of several vital organs revealed that both HLA-DR3.IFN-γ(+/+) and HLA-DR3.IFN-γ(-/-) transgenic mice displayed comparable severe inflammatory changes in lungs, and liver during TSS. Remarkably, whereas the small intestines from HLA-DR3.IFN-γ(+/+) transgenic mice displayed significant pathological changes during TSS, the architecture of small intestines in HLA-DR3.IFN-γ(-/-) transgenic mice was preserved. In concordance with these histopathological changes, the gut permeability to macromolecules was dramatically increased in HLA-DR3.IFN-γ(+/+) but not HLA-DR3.IFN-γ(-/-) mice during TSS. Overall, IFN-γ seemed to play a lethal role in the immunopathogenesis of TSS by inflicting fatal small bowel pathology. Our study thus identifies the important role for IFN-γ in TSS.

Natural Indoles, Indole-3-Carbinol (I3C) and 3,3’-Diindolylmethane (DIM), Attenuate Staphylococcal Enterotoxin B-Mediated Liver Injury by Downregulating miR-31 Expression and Promoting Caspase-2-Mediated Apoptosis

PubMed Central

Busbee, Philip B.; Nagarkatti, Mitzi; Nagarkatti, Prakash S.

2015-01-01

Staphylococcal enterotoxin B (SEB) is a potent superantigen capable of inducing inflammation characterized by robust immune cell activation and proinflammatory cytokine release. Exposure to SEB can result in food poisoning as well as fatal conditions such as toxic shock syndrome. In the current study, we investigated the effect of natural indoles including indole-3-carbinol (I3C) and 3,3’-diindolylmethane (DIM) on SEB-mediated liver injury. Injection of SEB into D-galactosamine-sensitized female C57BL/6 mice resulted in liver injury as indicated by an increase in enzyme aspartate transaminase (AST) levels, induction of inflammatory cytokines, and massive infiltration of immune cells into the liver. Administration of I3C and DIM (40mg/kg), by intraperitonal injection, attenuated SEB-induced acute liver injury, as evidenced by decrease in AST levels, inflammatory cytokines and cellular infiltration in the liver. I3C and DIM triggered apoptosis in SEB-activated T cells primarily through activation of the intrinsic mitochondrial pathway. In addition, inhibitor studies involving caspases revealed that I3C and DIM-mediated apoptosis in these activated cells was dependent on caspase-2 but independent of caspase-8, 9 and 3. In addition, I3C and DIM caused a decrease in Bcl-2 expression. Both compounds also down-regulated miR-31, which directly targets caspase-2 and influences apoptosis in SEB-activated cells. Our data demonstrate for the first time that indoles can effectively suppress acute hepatic inflammation caused by SEB and that this may be mediated by decreased expression of miR-31 and consequent caspase-2-dependent apoptosis in T cells. PMID:25706292

Spectral surface plasmon resonance biosensor for detection of staphylococcal enterotoxin B in milk.

PubMed

Homola, Jirí; Dostálek, Jakub; Chen, Shengfu; Rasooly, Avraham; Jiang, Shaoyi; Yee, Sinclair S

2002-05-05

This work evaluates a newly developed wavelength modulation-based SPR biosensor for the detection of staphylococcal enterotoxin B (SEB) in milk. Two modes of operation of the SPR biosensor are described: direct detection of SEB and sandwich assay. In the sandwich assay detection mode, secondary antibodies are bound to the already captured toxin to amplify sensor response. Samples including SEB in buffer and SEB in milk were analyzed in this work. The SPR biosensor has been shown to be capable of directly detecting concentrations of SEB in buffer as low as 5 ng/ml. In sandwich detection mode, the lowest detection limit was determined to be 0.5 ng/ml for both buffer and milk samples. The reported wavelength modulation-based SPR sensor provides a generic platform which can be tailored for detection of various foodborne pathogens and agents for food analysis and testing.

A model of the ground surface temperature for micrometeorological analysis

NASA Astrophysics Data System (ADS)

Leaf, Julian S.; Erell, Evyatar

2017-07-01

Micrometeorological models at various scales require ground surface temperature, which may not always be measured in sufficient spatial or temporal detail. There is thus a need for a model that can calculate the surface temperature using only widely available weather data, thermal properties of the ground, and surface properties. The vegetated/permeable surface energy balance (VP-SEB) model introduced here requires no a priori knowledge of soil temperature or moisture at any depth. It combines a two-layer characterization of the soil column following the heat conservation law with a sinusoidal function to estimate deep soil temperature, and a simplified procedure for calculating moisture content. A physically based solution is used for each of the energy balance components allowing VP-SEB to be highly portable. VP-SEB was tested using field data measuring bare loess desert soil in dry weather and following rain events. Modeled hourly surface temperature correlated well with the measured data (r 2 = 0.95 for a whole year), with a root-mean-square error of 2.77 K. The model was used to generate input for a pedestrian thermal comfort study using the Index of Thermal Stress (ITS). The simulation shows that the thermal stress on a pedestrian standing in the sun on a fully paved surface, which may be over 500 W on a warm summer day, may be as much as 100 W lower on a grass surface exposed to the same meteorological conditions.

Using local climate zone classifications to assess the influence of urban morphology on the urban heat island effect

NASA Astrophysics Data System (ADS)

Satcher, P. S.; Brunsell, N. A.

2017-12-01

Alterations to land cover resulting from urbanization interact with the atmospheric boundary layer inducing elevated surface and air temperatures, changes to the surface energy balance (SEB), and modifications to regional circulations and climates. These changes pose risks to public health, ecological systems, and have the potential to affect economic interests. We used Google Earth Engine's Landsat archive to classify local climate zones (LCZ) that consist of ten urban and seven non-urban classes to examine the influence of urban morphology on the urban heat island (UHI) effect. We used geostatistical methods to determine the significance of the spatial distributions of LCZs to land surface temperatures (LST) and normalized difference vegetation index (NDVI) Moderate Resolution Imaging Spectroradiometer (MODIS) products. We used the triangle method to assess the variability of SEB partitioning in relation to high, medium, and low density LCZ classes. Fractional vegetation cover (Fr) was calculated using NDVI data. Linear regressions of observations in Fr-LST space for select LCZ classes were compared for selected eight-day periods to determine changes in energy partitioning and relative soil moisture availability. The magnitude of each flux is not needed to determine changes to the SEB. The regressions will examine near surface soil moisture, which is indicative of how much radiation is partitioned into evaporation. To compare changes occurring over one decade, we used MODIS NDVI and LST data from 2005 and 2015. Results indicated that variations in the SEB can be detected using the LCZ classification method. The results from analysis in Fr-LST space of the annual cycles over several years can be used to detect changes in the SEB as urbanization increases.

Late Multiple Organ Surge in Interferon-Regulated Target Genes Characterizes Staphylococcal Enterotoxin B Lethality

PubMed Central

Ferreyra, Gabriela A.; Elinoff, Jason M.; Demirkale, Cumhur Y.; Starost, Matthew F.; Buckley, Marilyn; Munson, Peter J.; Krakauer, Teresa; Danner, Robert L.

2014-01-01

Background Bacterial superantigens are virulence factors that cause toxic shock syndrome. Here, the genome-wide, temporal response of mice to lethal intranasal staphylococcal enterotoxin B (SEB) challenge was investigated in six tissues. Results The earliest responses and largest number of affected genes occurred in peripheral blood mononuclear cells (PBMC), spleen, and lung tissues with the highest content of both T-cells and monocyte/macrophages, the direct cellular targets of SEB. In contrast, the response of liver, kidney, and heart was delayed and involved fewer genes, but revealed a dominant genetic program that was seen in all 6 tissues. Many of the 85 uniquely annotated transcripts participating in this shared genomic response have not been previously linked to SEB. Nine of the 85 genes were subsequently confirmed by RT-PCR in every tissue/organ at 24 h. These 85 transcripts, up-regulated in all tissues, annotated to the interferon (IFN)/antiviral-response and included genes belonging to the DNA/RNA sensing system, DNA damage repair, the immunoproteasome, and the ER/metabolic stress-response and apoptosis pathways. Overall, this shared program was identified as a type I and II interferon (IFN)-response and the promoters of these genes were highly enriched for IFN regulatory matrices. Several genes whose secreted products induce the IFN pathway were up-regulated at early time points in PBMCs, spleen, and/or lung. Furthermore, IFN regulatory factors including Irf1, Irf7 and Irf8, and Zbp1, a DNA sensor/transcription factor that can directly elicit an IFN innate immune response, participated in this host-wide SEB signature. Conclusion Global gene-expression changes across multiple organs implicated a host-wide IFN-response in SEB-induced death. Therapies aimed at IFN-associated innate immunity may improve outcome in toxic shock syndromes. PMID:24551153

Characterisation of the atmospheric surface layer over a debris cover glacier in the Nepal Himalayas.

NASA Astrophysics Data System (ADS)

Litt, M.; Steiner, J. F.; Stigter, E.; Bierkens, M. F.; Shea, J. M.; Immerzeel, W. W.

2017-12-01

A significant area of Himalayan glaciers tongues is covered by debris. Turbulent exchanges of sensible and latent heat at the debris surface directly act on its surface energy balance (SEB). At the same time, the large turbulent water vapour exchanges at high altitude modify the debris water content and thus its thermal properties. These must be correctly accounted for in SEB models and a proper characterisation of the atmospheric surface layer (ASL) is therefore needed. We installed an eddy-correlation system (Campbell IRGASON) during a period of 15 days over the Lirung glacier in the Langtang Valley in Nepal in the Nepal Himalaya, during the transition period between the monsoon and the dry season. We present the main characteristics of our set-up and the implication of our ASL characterisation on the parameterisation of the turbulent fluxes. During the day, moderate winds blow up-valley and the ASL is mostly unstable. Latent (sensible) heat fluxes scale between 50 and 150 (50 and 250) Wm-2 during the day, thus drying and cooling the debris and playing a significant role in the SEB. During the night, weak down-glacier winds are observed and fluxes remain weak. Spectral analysis of the turbulent data indicate that flow characteristics do not fulfil theoretical requirements needed to estimate turbulent fluxes using bulk methods and at this site our data show they would work only for the sensible heat flux evaluation.

An Analysis of High School Students' Performance on Five Integrated Science Process Skills

NASA Astrophysics Data System (ADS)

Beaumont-Walters, Yvonne; Soyibo, Kola

2001-02-01

This study determined Jamaican high school students' level of performance on five integrated science process skills and if there were statistically significant differences in their performance linked to their gender, grade level, school location, school type, student type and socio-economic background (SEB). The 305 subjects comprised 133 males, 172 females, 146 ninth graders, 159 10th graders, 150 traditional and 155 comprehensive high school students, 164 students from the Reform of Secondary Education (ROSE) project and 141 non-ROSE students, 166 urban and 139 rural students and 110 students from a high SEB and 195 from a low SEB. Data were collected with the authors' constructed integrated science process skills test the results indicated that the subjects' mean score was low and unsatisfactory; their performance in decreasing order was: interpreting data, recording data, generalising, formulating hypotheses and identifying variables; there were statistically significant differences in their performance based on their grade level, school type, student type, and SEB in favour of the 10th graders, traditional high school students, ROSE students and students from a high SEB. There was a positive, statistically significant and fairly strong relationship between their performance and school type, but weak relationships among their student type, grade level and SEB and performance.

Attenuation of massive cytokine response to the staphylococcal enterotoxin B superantigen by the innate immunomodulatory protein lactoferrin

PubMed Central

Hayworth, J L; Kasper, K J; Leon-Ponte, M; Herfst, C A; Yue, D; Brintnell, W C; Mazzuca, D M; Heinrichs, D E; Cairns, E; Madrenas, J; Hoskin, D W; McCormick, J K; Haeryfar, S M M

2009-01-01

Staphylococcal enterotoxin B (SEB) is a pyrogenic exotoxin and a potent superantigen which causes massive T cell activation and cytokine secretion, leading to profound immunosuppression and morbidity. The inhibition of SEB-induced responses is thus considered a goal in the management of certain types of staphylococcal infections. Lactoferrin (LF) is a multi-functional glycoprotein with both bacteriostatic and bactericidal activities. In addition, LF is known to have potent immunomodulatory properties. Given the anti-microbial and anti-inflammatory properties of this protein, we hypothesized that LF can modulate T cell responses to SEB. Here, we report that bovine LF (bLF) was indeed able to attenuate SEB-induced proliferation, interleukin-2 production and CD25 expression by human leucocyte antigen (HLA)-DR4 transgenic mouse T cells. This inhibition was not due to bLF's iron-binding capacity, and could be mimicked by the bLF-derived peptide lactoferricin. Cytokine secretion by an engineered SEB-responsive human Jurkat T cell line and by peripheral blood mononuclear cells from healthy donors was also inhibited by bLF. These findings reveal a previously unrecognized property of LF in modulation of SEB-triggered immune activation and suggest a therapeutic potential for this naturally occurring protein during toxic shock syndrome. PMID:19659771

Interferon Gamma-Dependent Intestinal Pathology Contributes to the Lethality in Bacterial Superantigen-Induced Toxic Shock Syndrome

PubMed Central

Tilahun, Ashenafi Y.; Holz, Marah; Wu, Tsung-Teh; David, Chella S.; Rajagopalan, Govindarajan

2011-01-01

Toxic shock syndrome (TSS) caused by the superantigen exotoxins of Staphylococcus aureus and Streptococcus pyogenes is characterized by robust T cell activation, profound elevation in systemic levels of multiple cytokines, including interferon-γ (IFN-γ), followed by multiple organ dysfunction and often death. As IFN-γ possesses pro- as well as anti-inflammatory properties, we delineated its role in the pathogenesis of TSS. Antibody-mediated in vivo neutralization of IFN-γ or targeted disruption of IFN-γ gene conferred significant protection from lethal TSS in HLA-DR3 transgenic mice. Following systemic high dose SEB challenge, whereas the HLA-DR3.IFN-γ+/+ mice became sick and succumbed to TSS, HLA-DR3.IFN-γ−/− mice appeared healthy and were significantly protected from SEB-induced lethality. SEB-induced systemic cytokine storm was significantly blunted in HLA-DR3.IFN-γ−/− transgenic mice. Serum concentrations of several cytokines (IL-4, IL-10, IL-12p40 and IL-17) and chemokines (KC, rantes, eotaxin and MCP-1) were significantly lower in HLA-DR3.IFN-γ−/− transgenic mice. However, SEB-induced T cell expansion in the spleens was unaffected and expansion of SEB-reactive TCR Vβ8+ CD4+ and CD8+ T cells was even more pronounced in HLA-DR3.IFN-γ−/− transgenic mice when compared to HLA-DR3.IFN-γ+/+ mice. A systematic histopathological examination of several vital organs revealed that both HLA-DR3.IFN-γ+/+ and HLA-DR3.IFN-γ−/− transgenic mice displayed comparable severe inflammatory changes in lungs, and liver during TSS. Remarkably, whereas the small intestines from HLA-DR3.IFN-γ+/+ transgenic mice displayed significant pathological changes during TSS, the architecture of small intestines in HLA-DR3.IFN-γ−/− transgenic mice was preserved. In concordance with these histopathological changes, the gut permeability to macromolecules was dramatically increased in HLA-DR3.IFN-γ+/+ but not HLA-DR3.IFN-γ−/− mice during TSS. Overall, IFN-γ seemed to play a lethal role in the immunopathogenesis of TSS by inflicting fatal small bowel pathology. Our study thus identifies the important role for IFN-γ in TSS. PMID:21304813

First observation of proton induced power MOSFET burnout in space: the CRUX experiment on APEX

NASA Astrophysics Data System (ADS)

Adolphsen, J. W.; Barth, J. L.; Gee, G. B.

1996-12-01

Ground testing has shown that power MOSFETs are susceptible to burnout when irradiated with heavy ions and protons. Satellite data from the Cosmic Ray Upset Experiment (CRUX) demonstrate that single event burnouts (SEBs) on 100-volt and 200-volt power MOSFETs can and do occur in space. Few SEBs occurred on the 100-volt devices, all at L/sup 1/>3. The 200-volt devices experienced many SEBs at L<3 when drain-to-source voltage (V/sub D-S/) was greater than 85% of maximum rated voltage. CRUX flight lot devices were ground tested with protons. The SEB rates calculated with the cross-sections from the ground tests show close agreement with the measured rates.

Blood Selenium Concentration and Blood Cystatin C Concentration in a Randomly Selected Population of Healthy Children Environmentally Exposed to Lead and Cadmium.

PubMed

Gać, Paweł; Pawlas, Natalia; Wylężek, Paweł; Poręba, Rafał; Poręba, Małgorzata; Pawlas, Krystyna

2017-01-01

This study aimed at evaluation of a relationship between blood selenium concentration (Se-B) and blood cystatin C concentration (CST) in a randomly selected population of healthy children, environmentally exposed to lead and cadmium. The studies were conducted on 172 randomly selected children (7.98 ± 0.97 years). Among participants, the subgroups were distinguished, manifesting marginally low blood selenium concentration (Se-B 40-59 μg/l), suboptimal blood selenium concentration (Se-B: 60-79 μg/l) or optimal blood selenium concentration (Se-B ≥ 80 μg/l). At the subsequent stage, analogous subgroups of participants were selected separately in groups of children with BMI below median value (BMI <16.48 kg/m 2 ) and in children with BMI ≥ median value (BMI ≥16.48 kg/m 2 ). In all participants, values of Se-B and CST were estimated. In the entire group of examined children no significant differences in mean CST values were detected between groups distinguished on the base of normative Se-B values. Among children with BMI below 16.48 kg/m 2 , children with marginally low Se-B manifested significantly higher mean CST values, as compared to children with optimum Se-B (0.95 ± 0.07 vs. 0.82 ± 0.15 mg/l, p < 0.05). In summary, in a randomly selected population of healthy children no relationships could be detected between blood selenium concentration and blood cystatin C concentration. On the other hand, in children with low body mass index, a negative non-linear relationship was present between blood selenium concentration and blood cystatin C concentration.

3,3′-Diindolylmethane Ameliorates Staphylococcal Enterotoxin B–Induced Acute Lung Injury through Alterations in the Expression of MicroRNA that Target Apoptosis and Cell-Cycle Arrest in Activated T Cells

PubMed Central

Elliott, David M.; Nagarkatti, Mitzi

2016-01-01

3,3′-Diindolylmethane (DIM), a natural indole found in cruciferous vegetables, has significant anti-cancer and anti-inflammatory properties. In this current study, we investigated the effects of DIM on acute lung injury (ALI) induced by exposure to staphylococcal enterotoxin B (SEB). We found that pretreatment of mice with DIM led to attenuation of SEB-induced inflammation in the lungs, vascular leak, and IFN-γ secretion. Additionally, DIM could induce cell-cycle arrest and cell death in SEB-activated T cells in a concentration-dependent manner. Interestingly, microRNA (miRNA) microarray analysis uncovered an altered miRNA profile in lung-infiltrating mononuclear cells after DIM treatment of SEB-exposed mice. Moreover, computational analysis of miRNA gene targets and regulation networks indicated that DIM alters miRNA in the cell death and cell-cycle progression pathways. Specifically, DIM treatment significantly downregulated several miRNA and a correlative increase associated gene targets. Furthermore, overexpression and inhibition studies demonstrated that DIM-induced cell death, at least in part, used miR-222. Collectively, these studies demonstrate for the first time that DIM treatment attenuates SEB-induced ALI and may do so through the induction of microRNAs that promote apoptosis and cell-cycle arrest in SEB-activated T cells. PMID:26818958

Single-event burnout hardening of planar power MOSFET with partially widened trench source

NASA Astrophysics Data System (ADS)

Lu, Jiang; Liu, Hainan; Cai, Xiaowu; Luo, Jiajun; Li, Bo; Li, Binhong; Wang, Lixin; Han, Zhengsheng

2018-03-01

We present a single-event burnout (SEB) hardened planar power MOSFET with partially widened trench sources by three-dimensional (3D) numerical simulation. The advantage of the proposed structure is that the work of the parasitic bipolar transistor inherited in the power MOSFET is suppressed effectively due to the elimination of the most sensitive region (P-well region below the N+ source). The simulation result shows that the proposed structure can enhance the SEB survivability significantly. The critical value of linear energy transfer (LET), which indicates the maximum deposited energy on the device without SEB behavior, increases from 0.06 to 0.7 pC/μm. The SEB threshold voltage increases to 120 V, which is 80% of the rated breakdown voltage. Meanwhile, the main parameter characteristics of the proposed structure remain similar with those of the conventional planar structure. Therefore, this structure offers a potential optimization path to planar power MOSFET with high SEB survivability for space and atmospheric applications. Project supported by the National Natural Science Foundation of China (Nos. 61404161, 61404068, 61404169).

Differential RNA regulation by staphylococcal enterotoxins A and B in murine macrophages

NASA Technical Reports Server (NTRS)

Chapes, S. K.; Beharka, A. A.; Hart, M. E.; Smeltzer, M. S.; Iandolo, J. J.; Spooner, B. S. (Principal Investigator)

1994-01-01

Staphylococcal enterotoxin A (SEA) is significantly better than enterotoxin B (SEB) in activating tumor necrosis factor (TNF) secretion by B6MP102 cells. Both toxins bound to B6MP102 cells; however, SEB competed less effectively with SEA than SEA competed with SEB. This suggested that receptors unique to SEA were present on B6MP102 cells. Signal transduction occurred in response to both toxins. Within 30 s after addition, SEA and SEB significantly increased the F-actin concentration in B6MP102 cells. However, only SEA induced increased TNF mRNA levels. B6MP102 cells incubated with interferon-gamma and SEB secreted TNF. However, enhanced mRNA expression was delayed and the concentration of TNF secreted was less than that of B6MP102 cells stimulated with SEA. Although these data suggest that receptors unique to SEA are present on B6MP102 cells, they also indicate that staphylococcal enterotoxins differentially regulate TNF at the RNA level, perhaps because of differences in binding to the plasma membrane.

The location and extent of exfoliation of clay on the fracture mechanisms in nylon 66-based ternary nanocomposites.

PubMed

Dasari, Aravind; Yu, Zhong-Zhen; Mai, Yiu-Wing; Yang, Mingshu

2008-04-01

The primary focus of this work is to elucidate the location and extent of exfoliation of clay on fracture (under both static and dynamic loading conditions) of melt-compounded nylon 66/clay/SEBS-g-MA ternary nanocomposites fabricated by different blending sequences. Distinct microstructures are obtained depending on the blending protocol employed. The state of exfoliation and dispersion of clay in nylon 66 matrix and SEBS-g-MA phase are quantified and the presence of clay in rubber is shown to have a negative effect on the toughness of the nanocomposites. The level of toughness enhancement of ternary nanocomposites depends on the blending protocol and the capability of different fillers to activate the plastic deformation mechanisms in the matrix. These mechanisms include: cavitation of SEBS-g-MA phase, stretching of voided matrix material, interfacial debonding of SEBS-g-MA particles, debonding of intercalated clay embedded inside the SEBS-g-MA phase, and delamination of intercalated clay platelets. Based on these results, new insights and approaches for the processing of better toughened polymer ternary nanocomposites are discussed.

The influence of caregiver depression on children in non-relative foster care versus kinship care placements.

PubMed

Garcia, Antonio; O'Reilly, Amanda; Matone, Meredith; Kim, Minseop; Long, Jin; Rubin, David M

2015-03-01

Little is known about how the challenges faced by caregivers influence the variation in social, emotional, and behavioral (SEB) outcomes of youth placed in kinship versus non-relative foster care. This study examined SEB symptoms among youth in kinship and non-relative foster care settings, hypothesizing that changes in caregiver depression would modify children's change in behavior over time. Child Behavior Checklist (CBCL) assessments of 199 children placed with kinship and non-relative foster care providers in a Mid-Atlantic city were conducted at time of placement and 6-12 months post-placement. Linear regression estimated CBCL change scores for youth across placement type and caregiver depression trajectories. Kinship caregivers were more likely to become depressed or remained depressed than non-relative foster caregivers. Youth in kinship care always exhibited better change in SEB outcomes than youth in non-relative foster care, but these positive outcomes were principally observed among families where caregivers demonstrated a reduction in depression over time or were never depressed. Adjusted change scores for non-relative foster care youth were always negative, with the most negative scores among youth whose caregivers became depressed over time. Caregiver well-being may modify the influence of placement setting on SEB outcomes for youth placed into out-of-home care. Findings lend to policy relevance for child welfare systems that seek kinship settings as a panacea to the challenges faced by youth, without allocating resources to address caregiver needs.

An Investigation of Language Environment Analysis Measures for Spanish-English Bilingual Preschoolers From Migrant Low-Socioeconomic-Status Backgrounds.

PubMed

Wood, Carla; Diehm, Emily A; Callender, Maya F

2016-04-01

The current study was designed to (a) describe average hourly Language Environment Analysis (LENA) data for preschool-age Spanish-English bilinguals (SEBs) and typically developing monolingual peers and (b) compare LENA data with mean length of utterance in words (MLUw) and total number of words (TNW) calculated on a selected sample of consecutive excerpts of audio files (CEAFs). Investigators examined average hourly child vocalizations from daylong LENA samples for 42 SEBs and 39 monolingual English-speaking preschoolers. The relationship between average hourly child vocalizations, conversational turns, and adult words from the daylong samples and MLUw from a 50-utterance CEAF was examined and compared between groups. MLUw, TNW, average hourly child vocalizations, and conversational turns were lower for young SEBs than monolingual English-speaking peers. Average hourly child vocalizations were not strongly related to MLUw performance for monolingual or SEB participants (r = .29, r = .25, respectively). In a similar manner, average hourly conversational turns were not strongly related to MLUw for either group (r = .22, r = .21, respectively). Young SEBs from socioeconomically disadvantaged backgrounds showed lower average performance on LENA measures, MLUw, and TNW than monolingual English-speaking peers. MLUw from monolinguals were also lower than typical expectations when derived from CEAFs. LENA technology may be a promising tool for communication sampling with SEBs; however, more research is needed to establish norms for interpreting MLUw and TNW from selected CEAF samples.

Prevalence of serum IgE antibodies to the Staphylococcus aureus enterotoxins (SAE, SEB, SEC, SED, TSST-1) in patients with persistent allergic rhinitis.

PubMed

Rossi, Renato Enzo; Monasterolo, Giorgio

2004-03-01

Enterotoxins produced by Staphylococcus aureus and their specific IgE antibodies were thought to be important in worsening atopic dermatitis. However, few studies have documented an association between S. aureus or its exotoxins and exacerbations of upper airway/nasal disease. In the current study, we determined the prevalence of serum-specific IgE towards staphylococcal enterotoxin A, B, C, D (SEA, SEB, SEC, SED) and toxic shock syndrome toxin 1 (TSST-1) in patients suffering from rhinitis and/or asthma due to allergy. Therefore, we examined whether SEA, SEB, SEC, SED and TSST-1 were important in worsening the clinical status of patients allergic to house dust mites by means of assessing serum eosinophil cationic protein (ECP), which is thought to be a reliable marker of asthma and rhinitis severity. 198 patients with persistent allergic rhinitis and/or asthma due to house dust mites were evaluated. Specific IgE towards SEA, SEB, SEC, SED, TSST-1, timothy grass and birch pollen recombinant allergens, and other aeroallergen extracts from common allergen sources were evaluated by the Pharmacia CAP System. Serum ECP was assessed, too. The percentages of sensitization to staphylococcal enterotoxins of 198 house dust mite-allergic patients were as follows: TSST-1-specific IgE 24.7% (n=49), SEC-specific IgE 22.2% (n=44), SEB-specific IgE 15.1% (n=30), SEA-specific IgE 9.1% (n=18), and SED-specific IgE 5.5% (n=11). Out of 198 individuals allergic to house dust mites 136 patients suffering from persistent rhinitis were subdivided into two subgroups: 53 patients with serum-specific IgE to at least one staphylococcal enterotoxin and 83 patients without specific IgE towards staphylococcal enterotoxins. Patients sensitive to staphylococcal enterotoxins had higher serum ECP levels than patients lacking specific IgE to SEA, SEB, SEC, SED and TSST-1(geometric mean 24.3 vs. 16.6 microg/100 ml; p=0.029), as well as total IgE levels (geometric mean 564 vs. 161 kU/l, p=0.00063) and specific IgE to Dermatophagoides pteronyssinus (geometric mean 16.7 vs. 6.6 kU/l; p=0.0235) and Dermatophagoides farinae (geometric mean 18.6 vs. 7.8 kU/l; p=0.0246). A status of sensitization to staphylococcal enterotoxins seems to be a factor increasing serum ECP, which is thought to be a reliable marker of clinical severity of allergic disease. Therefore, the evaluation of SEA, SEB, SEC, SED and TSST-1-specific IgE antibodies may have additional significance for the prognosis of persistent allergic diseases of the upper airway. Copyright 2004 S. Karger AG, Basel

On Averaging Timescales for the Surface Energy Budget Closure Problem

NASA Astrophysics Data System (ADS)

Grachev, A. A.; Fairall, C. W.; Persson, O. P. G.; Uttal, T.; Blomquist, B.; McCaffrey, K.

2017-12-01

An accurate determination of the surface energy budget (SEB) and all SEB components at the air-surface interface is of obvious relevance for the numerical modelling of the coupled atmosphere-land/ocean/snow system over different spatial and temporal scales, including climate modelling, weather forecasting, environmental impact studies, and many other applications. This study analyzes and discusses comprehensive measurements of the SEB and the surface energy fluxes (turbulent, radiative, and ground heat) made over different underlying surfaces based on the data collected during several field campaigns. Hourly-averaged, multiyear data sets collected at two terrestrial long-term research observatories located near the coast of the Arctic Ocean at Eureka (Canadian Archipelago) and Tiksi (East Siberia) and half-hourly averaged fluxes collected during a year-long field campaign (Wind Forecast Improvement Project 2, WFIP 2) at the Columbia River Gorge (Oregon) in areas of complex terrain. Our direct measurements of energy balance show that the sum of the turbulent sensible and latent heat fluxes systematically underestimate the available energy at half-hourly and hourly time scales by around 20-30% at these sites. This imbalance of the surface energy budget is comparable to other terrestrial sites. Surface energy balance closure is a formulation of the conservation of energy principle (the first law of thermodynamics). The lack of energy balance closure at hourly time scales is a fundamental and pervasive problem in micrometeorology and may be caused by inaccurate estimates of the energy storage terms in soils, air and biomass in the layer below the measurement height and above the heat flux plates. However, the residual energy imbalance is significantly reduced at daily and monthly timescales. Increasing the averaging time to daily scales substantially reduces the storage terms because energy locally entering the soil, air column, and vegetation in the morning is released in the afternoon and evening.

Lab-On-a-Chip for carbon nanotubes based immunoassay detection of Staphylococcal Enterotoxin B (SEB).

PubMed

Yang, Minghui; Sun, Steven; Kostov, Yordan; Rasooly, Avraham

2010-04-21

We describe a new eight channel Lab-On-a-Chip (LOC) for a Carbon Nanotube (CNT) based immunoassay with optical detection of Staphylococcal Enterotoxin B (SEB) for food safety applications. In this work, we combined four biosensing elements: (1) CNT technology for primary antibody immobilization, (2) Enhanced Chemiluminescence (ECL) for light signal generation, (3) a cooled charge-coupled device (CCD) for detection and (4) polymer lamination technology for developing a point of care immunological assay for SEB detection. Our concept for developing versatile LOCs, which can be used for many different applications, is to use a modular design with interchangeable recognition elements (e.g. various antibodies) to determine the specificity. Polymer lamination technology was used for the fabrication of a six layer, syringe operated LOC capable of analyzing eight samples simultaneously. An anti-SEB antibody-nanotube mixture was immobilized onto a polycarbonate strip, to serve as an interchangeable ligand surface that was then bonded onto the LOC. SEB samples are loaded into the device and detected by an ELISA assay using Horse Radish Peroxidase (HRP) conjugated anti-SEB IgG as a secondary antibody and ECL, with detection by a previously described portable cooled CCD detector. Eight samples of SEB in buffer or soy milk were assayed simultaneously with a limit of detection of 0.1 ng mL(-1). CNT immobilization of the antibody increased the sensitivity of detection six fold. Use of a simple interchangeable immunological surface allows this LOC to be adapted to any immunoassay by simply replacing the ligand surface. A syringe was used to move fluids for this assay so no power is needed to operate the device. Our versatile portable point-of-care CCD detector combined with the LOC immunoassay method described here can be used to reduce the exposure of users to toxins and other biohazards when working outside the lab, as well as to simplify and increase sensitivity for many other types of immunological diagnostics and detection assays.

Incidence of enterotoxigenic staphylococci and their toxins in foods.

PubMed

Soriano, J M; Font, G; Rico, H; Moltó, J C; Mañes, J

2002-05-01

Of 504 food samples collected from cafeterias, 19 (3.8%) yielded strains of enterotoxigenic staphylococci, and 10 (52.6%), 4 (21.1%), 3 (15.8%), and 2 (10.5%) of these strains produced enterotoxins C (SEC), D (SED), B (SEB), and A (SEA), respectively. Moreover, SEA, SEB, and SEC were isolated from three hamburger samples. Of 181 food samples collected from four restaurants before the implementation of the hazard analysis and critical control point (HACCP) system, 7 (3.9%) were found to contain enterotoxigenic strains, and SED, SEC, and SEA were produced by 4 (57.1%), 2 (28.6%), and 1 (14.3%) of these strains, respectively. One meatball sample with SEC was detected in a restaurant. After the implementation of the HACCP system in four restaurants, neither enterotoxigenic staphylococci nor enterotoxins were detected in 196 studied samples.

Nanoshell-Enhanced Raman Spectroscopy on a Microplate for Staphylococcal Enterotoxin B Sensing.

PubMed

Wang, Wenbin; Wang, Weiwei; Liu, Liqiang; Xu, Liguang; Kuang, Hua; Zhu, Jianping; Xu, Chuanlai

2016-06-22

A sensitive surface-enhanced Raman scattering (SERS) immunosensor based on the Au nanoparticle (Au NP) shell structure was developed to detect staphylococcal enterotoxin B (SEB) on a microplate. Au NPs modified with 4-nitrothiophenol (4-NTP) and coated with Ag shell of controlled thickness at 6.6 nm exhibited excellent SERS intensity and were used as signal reporters in the detection of SEB. The engaged 4-NTP allowed the significant electromagnetic enhancement between Au NPs and the Ag shell and prevented the dissociation of the Raman reporter. More importantly, 4-NTP-differentiated SERS signals between the sample and microplate. The SERS-based immunosensor had a limit of detection of 1.3 pg/mL SEB. Analysis of SEB-spiked milk samples revealed that the developed method had high accuracy. Therefore, the SERS-encoded Au@Ag core-shell structure-based immunosensor is promising for the detection of biotoxins, pathogens, and environmental pollutants.

Integration of Process Models and Remote Sensing for Estimating Productivity, Soil Moisture, and Energy Fluxes in a Tallgrass Prairie Ecosystem

EPA Science Inventory

We describe a research program aimed at integrating remotely sensed data with an ecosystem model (VELMA) and a soil-vegetation-atmosphere transfer (SVAT) model (SEBS) for generating spatially explicit, regional scale estimates of productivity (biomass) and energy\\mass exchanges i...

Do child healthcare professionals and parents recognize social-emotional and behavioral problems in 1-year-old infants?

PubMed

Alakortes, Jaana; Kovaniemi, Susanna; Carter, Alice S; Bloigu, Risto; Moilanen, Irma K; Ebeling, Hanna E

2017-04-01

Growing evidence supports the existence of clinically significant social-emotional/behavioral (SEB) problems among as young as 1-year-old infants. However, a substantial proportion of early SEB problems remain unidentified during contacts with child healthcare professionals. In this study, child healthcare nurse (CHCN; N = 1008) and parental (N = 518) reports about SEB worries were gathered, along with the maternal and paternal Brief Infant-Toddler Social and Emotional Assessment (BITSEA) ratings, for 12-month-old infants randomly recruited through Finnish child health centers. Only 1.4-1.8 % of CHCNs, 3.9 % of mothers, and 3.2 % of fathers reported of being worried about the assessed child's SEB development. When the CHCNs' and parental reports were combined, 7.7 % (33/428) of the infants assessed each by all three adults had one (7.0 %), two (0.7 %) or three (0 %) worry reports. Even the combination of the CHCN's and parental worry reports identified only 7.0-13.8 % of the infants with the maternal and/or paternal BITSEA Problem or Competence rating in the of-concern range. Identified associations across the three informants' worry reports, parental BITSEA ratings and sociodemographic factors are discussed in the paper. Routine and frequent use of developmentally appropriate screening measures, such as the BITSEA, might enhance identification and intervening of early SEB problems in preventive child healthcare by guiding both professionals and parents to pay more attention to substantial aspects of young children's SEB development and encouraging them to discuss possible problems and worries.

Molecular docking of superantigens with class II major histocompatibility complex proteins.

PubMed

Olson, M A; Cuff, L

1997-01-01

The molecular recognition of two superantigens with class II major histocompatibility complex molecules was simulated by using protein-protein docking. Superantigens studied were staphylococcal enterotoxin B (SEB) and toxic shock syndrome toxin-1 (TSST-1) in their crystallographic assemblies with HLA-DR1. Rigid-body docking was performed sampling configurational space of the interfacial surfaces by employing a strategy of partitioning the contact regions on HLA-DR1 into separate molecular recognition units. Scoring of docked conformations was based on an electrostatic continuum model evaluated with the finite-difference Poisson-Boltzmann method. Estimates of nonpolar contributions were derived from the buried molecular surface areas. We found for both superantigens that docking the HLA-DR1 surface complementary with the SEB and TSST-1 contact regions containing a homologous hydrophobic surface loop provided sufficient recognition for the reconstitution of native-like conformers exhibiting the highest-scoring free energies. For the SEB complex, the calculations were successful in reproducing the total association free energy. A comparison of the free-energy determinants of the conserved hydrophobic contact residue indicates functional similarity between the two proteins for this interface. Though both superantigens share a common global association mode, differences in binding topology distinguish the conformational specificities underlying recognition.

Evaluation of handheld assays for the detection of ricin and staphylococcal enterotoxin B in disinfected waters.

PubMed

Wade, Mary Margaret; Biggs, Tracey D; Insalaco, Joseph M; Neuendorff, Lisa K; Bevilacqua, Vicky L H; Schenning, Amanda M; Reilly, Lisa M; Shah, Saumil S; Conley, Edward K; Emanuel, Peter A; Zulich, Alan W

2011-01-01

Development of a rapid field test is needed capable of determining if field supplies of water are safe to drink by the warfighter during a military operation. The present study sought to assess the effectiveness of handheld assays (HHAs) in detecting ricin and Staphylococcal Enterotoxin B (SEB) in water. Performance of HHAs was evaluated in formulated tap water with and without chlorine, reverse osmosis water (RO) with chlorine, and RO with bromine. Each matrix was prepared, spiked with ricin or SEB at multiple concentrations, and then loaded onto HHAs. HHAs were allowed to develop and then read visually. Limits of detection (LOD) were determined for all HHAs in each water type. Both ricin and SEB were detected by HHAs in formulated tap water at or below the suggested health effect levels of 455 ng/mL and 4.55 ng/mL, respectively. However, in brominated or chlorinated waters, LODs for SEB increased to approximately 2,500 ng/mL. LODs for ricin increased in chlorinated water, but still remained below the suggested health effect level. In brominated water, the LOD for ricin increased to approximately 2,500 ng/mL. In conclusion, the HHAs tested were less effective at detecting ricin and SEB in disinfected water, as currently configured.

Integrated Raman and angular scattering microscopy reveals chemical and morphological differences between activated and nonactivated CD8+ T lymphocytes

PubMed Central

Smith, Zachary J.; Wang, Jyh-Chiang E.; Quataert, Sally A.; Berger, Andrew J.

2010-01-01

Integrated Raman and angular-scattering microscopy (IRAM) is a multimodal platform capable of noninvasively probing both the chemistry and morphology of a single cell without prior labeling. Using this system, we are able to detect activation-dependent changes in the Raman and elastic-scattering signals from CD8+ T cells stimulated with either Staphylococcal enterotoxin B (SEB) or phorbol myristate acetate (PMA). In both cases, results obtained from the IRAM instrument correlate well with results obtained from traditional fluorescence-based flow cytometry for paired samples. SEB-mediated activation was distinguished from resting state in CD8+ T cells by an increase in the number and mean size of small (∼500-nm) elastic scatterers as well as a decrease in Raman bands, indicating changes in nuclear content. PMA-mediated activation induced a different profile in CD8+ T cells from SEB, showing a similar increase in small elastic scatterers but a different Raman change, with elevation of cellular protein and lipid bands. These results suggest the potential of this multimodal, label-free optical technique for studying processes in single cells. PMID:20615023

The relationship between environmental exposure to cadmium and lead and blood selenium concentration in randomly selected population of children inhabiting industrial regions of Silesian Voivodship (Poland).

PubMed

Gać, P; Pawlas, N; Poręba, R; Poręba, M; Pawlas, K

2014-06-01

This study aimed at determining the relationship between environmental exposure to lead (Pb) and cadmium (Cd) and blood selenium (Se) concentration in randomly selected population of children inhabiting the industrial regions of Silesian Voivodship, Poland. The study was conducted on a group of consecutive randomly selected 349 children aged below 15 years and inhabiting the industrial regions in Upper Silesia. The examined variables included whole blood Cd concentration (Cd-B), whole blood Pb concentration (Pb-B) and whole blood Se concentration (Se-B). The concentration of Cd-B, Pb-B and Se-B in the studied group of children amounted to 0.26 ± 0.14, 37.62 ± 25.30 and 78.31 ± 12.82 μg/L, respectively. In the entire examined group a statistically significant negative linear relationship was noted between Pb-B and Se-B (r = -0.12, p < 0.05). Also, a statistically insignificant negative correlation was detected between Cd-B and Se-B (r = -0.02, p > 0.05) and a statistically insignificant positive correlation between Pb-B and Cd-B (r = 0.08, p > 0.05). A multivariate backward stepwise regression analysis demonstrated that in the studied group of children higher Pb-B and a more advanced age-represented independent risk factors for a decreased Se-B. Environmental exposure to Pb may represent an independent risk factor for Se deficit in blood of the studied population of children. In children, the lowered Se-B may create one of the mechanisms in which Pb unfavourably affects human body. © The Author(s) 2014.

Exposure to inorganic mercury in vivo attenuates extrinsic apoptotic signaling in Staphylococcal aureus enterotoxin B stimulated T-cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laiosa, Michael D.; Eckles, Kevin G.; Langdon, Margaret

2007-12-15

The heavy metal mercury (Hg) is known to have immunomodulatory properties affecting lymphocyte signal transduction, death receptor signaling and autoimmunity. In this study we tested the hypothesis that Hg exposure would attenuate T-cell activation and caspase 8 and 3 activity in response to antigenic stimuli. To test this hypothesis, BALB/cJ mice were exposed to 10 mg/l mercuric chloride (HgCl{sub 2}) in their drinking water for 2 weeks followed by injection with 20 {mu}g of the Staphylococcal aureus enterotoxin B (SEB) superantigen. Eighteen hours after SEB challenge, there was a statistically significant reduction in caspase 8 and caspase 3 enzyme activitymore » in the SEB reactive V{beta}8+ T-cells. The attenuated caspase activity in Hg-exposed mice persisted for 48 h after exposure. Moreover, activation of caspase 8 and caspase 3 was reduced by more than 60% in CD95 deficient MRL/MpJ-Fas{sup lpr} mice demonstrating that caspase 8 and 3 activation in response to SEB is CD95 dependent. In addition to the effects of Hg on caspase activity, expression of the T-cell activation marker CD69 was also attenuated in SEB reactive V{beta}8 T-cells in Hg-exposed mice. Moreover, CD69 expression in MRL/MpJ-Fas{sup lpr} mice was also reduced. Taken together the caspase and CD69 data support a role for CD95 in promoting a proapoptotic and activated state in SEB responsive T-lymphocytes and this state is attenuated by the autoimmune potentiating environmental agent mercury.« less

Rapid and sensitive sandwich enzyme-linked immunosorbent assay for detection of staphylococcal enterotoxin B in cheese.

PubMed Central

Morissette, C; Goulet, J; Lamoureux, G

1991-01-01

A rapid and sensitive screening sandwich enzyme-linked immunosorbent assay (ELISA) was developed for the detection of staphylococcal enterotoxin B (SEB) in cheese by using a highly avid anti-SEB antibody (Ab) as the capture Ab (CAb) and as the biotinylated Ab conjugate. The glutaraldehyde fixation method for the immobilization of CAb on polystyrene dipsticks was superior to the adsorption fixation and the adsorption-glutaraldehyde fixation methods. The glutaraldehyde fixation method resulted in a higher surface-saturating CAb concentration as evaluated by the peroxidase saturation technique and by the ability of the CAb-coated dipstick to discriminate between positive and negative controls (index of discrimination). Of nine blocking agents used alone or in pairs, lysine-human serum albumin, bovine serum albumin, human serum albumin, and gelatin effectively saturated available sites on the CAb-coated dipsticks without causing interference with the antigen-Ab reactions. The addition of 1% polyethylene glycol to the diluent of the biotinylated anti-SEB Ab conjugate improved the detection of SEB. A concentration of 4% polyethylene glycol allowed a 5-min reaction time for the streptavidin-biotin-horseradish peroxidase conjugate. Cheddar cheese homogenate reduced the sensitivity of the SEB assay; however, the sensitivity was restored when 1.6% (wt/vol) of either a nonionic detergent (Mega-9) or two zwitterionic detergents (Zwittergent 3-10 and 3-12 detergent) was added to the diluent. By using the rapid sandwich ELISA, a minimum of 0.5 to 1.0 ng of SEB per ml was detected within 45 min. The whole procedure for the analysis of the cheddar cheese samples was completed within 1 h.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2039234

Triggering Mechanism for Neutron Induced Single-Event Burnout in Power Devices

NASA Astrophysics Data System (ADS)

Shoji, Tomoyuki; Nishida, Shuichi; Hamada, Kimimori

2013-04-01

Cosmic ray neutrons can trigger catastrophic failures in power devices. It has been reported that parasitic transistor action causes single-event burnout (SEB) in power metal-oxide-semiconductor field-effect transistors (MOSFETs) and insulated gate bipolar transistors (IGBTs). However, power diodes do not have an inherent parasitic transistor. In this paper, we describe the mechanism triggering SEB in power diodes for the first time using transient device simulation. Initially, generated electron-hole pairs created by incident recoil ions generate transient current, which increases the electron density in the vicinity of the n-/n+ boundary. The space charge effect of the carriers leads to an increase in the strength of the electric field at the n-/n+ boundary. Finally, the onset of impact ionization at the n-/n+ boundary can trigger SEB. Furthermore, this failure is closely related to diode secondary breakdown. It was clarified that the impact ionization at the n-/n+ boundary is a key point of the mechanism triggering SEB in power devices.

Staphylococcal enterotoxins bind H-2Db molecules on macrophages

NASA Technical Reports Server (NTRS)

Beharka, A. A.; Iandolo, J. J.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

1995-01-01

We screened a panel of monoclonal antibodies against selected macrophage cell surface molecules for their ability to inhibit enterotoxin binding to major histocompatibility complex class II-negative C2D (H-2b) macrophages. Two monoclonal antibodies, HB36 and TIB126, that are specific for the alpha 2 domain of major histocompatibility complex class I, blocked staphylococcal enterotoxins A and B (SEA and SEB, respectively) binding to C2D macrophages in a specific and concentration-dependent manner. Inhibitory activities were haplotype-specific in that SEA and SEB binding to H-2k or H-2d macrophages was not inhibited by either monoclonal antibody. HB36, but not TIB126, inhibited enterotoxin-induced secretion of cytokines by H-2b macrophages. Lastly, passive protection of D-galactosamine-sensitized C2D mice by injection with HB36 antibody prevented SEB-induced death. Therefore, SEA and SEB binding to the alpha 2 domain of the H-2Db molecule induces biological activity and has physiological consequences.

Evaluation of Handheld Assays for the Detection of Ricin and Staphylococcal Enterotoxin B in Disinfected Waters

PubMed Central

Wade, Mary Margaret; Biggs, Tracey D.; Insalaco, Joseph M.; Neuendorff, Lisa K.; Bevilacqua, Vicky L. H.; Schenning, Amanda M.; Reilly, Lisa M.; Shah, Saumil S.; Conley, Edward K.; Emanuel, Peter A.; Zulich, Alan W.

2011-01-01

Development of a rapid field test is needed capable of determining if field supplies of water are safe to drink by the warfighter during a military operation. The present study sought to assess the effectiveness of handheld assays (HHAs) in detecting ricin and Staphylococcal Enterotoxin B (SEB) in water. Performance of HHAs was evaluated in formulated tap water with and without chlorine, reverse osmosis water (RO) with chlorine, and RO with bromine. Each matrix was prepared, spiked with ricin or SEB at multiple concentrations, and then loaded onto HHAs. HHAs were allowed to develop and then read visually. Limits of detection (LOD) were determined for all HHAs in each water type. Both ricin and SEB were detected by HHAs in formulated tap water at or below the suggested health effect levels of 455 ng/mL and 4.55 ng/mL, respectively. However, in brominated or chlorinated waters, LODs for SEB increased to approximately 2,500 ng/mL. LODs for ricin increased in chlorinated water, but still remained below the suggested health effect level. In brominated water, the LOD for ricin increased to approximately 2,500 ng/mL. In conclusion, the HHAs tested were less effective at detecting ricin and SEB in disinfected water, as currently configured. PMID:21792355

13-cis Retinoic acid induces apoptosis and cell cycle arrest in human SEB-1 sebocytes.

PubMed

Nelson, Amanda M; Gilliland, Kathryn L; Cong, Zhaoyuan; Thiboutot, Diane M

2006-10-01

Isotretinoin (13-cis retinoic acid (13-cis RA)) is the most potent inhibitor of sebum production, a key component in the pathophysiology of acne, yet its mechanism of action remains largely unknown. The effects of 13-cis RA, 9-cis retinoic acid (9-cis RA), and all-trans retinoic acid (ATRA) on cell proliferation, apoptosis, and cell cycle proteins were examined in SEB-1 sebocytes and keratinocytes. 13-cis RA causes significant dose-dependent and time-dependent decreases in viable SEB-1 sebocytes. A portion of this decrease can be attributed to cell cycle arrest as evidenced by decreased DNA synthesis, increased p21 protein expression, and decreased cyclin D1. Although not previously demonstrated in sebocytes, we report that 13-cis RA induces apoptosis in SEB-1 sebocytes as shown by increased Annexin V-FITC staining, increased TUNEL staining, and increased cleaved caspase 3 protein. Furthermore, the ability of 13-cis RA to induce apoptosis cannot be recapitulated by 9-cis RA or ATRA, and it is not inhibited by the presence of a retinoid acid receptor (RAR) pan-antagonist AGN 193109. Taken together these data indicate that 13-cis RA causes cell cycle arrest and induces apoptosis in SEB-1 sebocytes by a RAR-independent mechanism, which contributes to its sebosuppressive effect and the resolution of acne.

Ground-Atmosphere Interactions at Gale: Determination of the Surface Energy Budget, Thermal Inertia and Water Sorption on the Regolith

NASA Astrophysics Data System (ADS)

Martinez, German; Renno, Nilton; Fischer, Erik; Borlina, Caue; Hallet, Bernard; De la Torre Juarez, Manuel; Vasavada, Aswhin; Gomez-Elvira, Javier

2014-05-01

The analysis of the Surface Energy Budget (SEB) yields insights into the local climate and the soil-atmosphere interactions, while the analysis of the thermal inertia of the shallow subsurface augments surface observations, providing information about the local geology. The Mars Global Surveyor Thermal Emission Spectrometer and the Mars Odyssey Thermal Emission Imaging System have measured near subsurface thermal inertia from orbit at scales of ~104 m2 to ~10 km2. Here we report analysis of the thermal inertia at a few locations at Gale Crater at scales of 100 m2. The thermal inertia is calculated by solving the heat conduction equation in the soil using hourly measurements by the Rover Environmental Station (REMS) ground temperature sensor as an upper boundary condition. Three Sols representative of different environmental conditions and soil properties, namely, Sol 82 at Rocknest (RCK), Sol 112 at Point Lake (PL) and Sol 139 at Yellowknife Bay (YKB) are analyzed in detail. The largest thermal inertia (I) value is found at YKB, I = 445 J m-2 K-1 s-1/2 or 445 tiu (thermal inertia unit), followed by PL with I= 300 tiu and RCK withI = 280 tiu [1]. These values are consistent with the type of terrain imaged by MastCam and with previous satellite estimates at Gale Crater [2,3]. The SEB is calculated by using all REMS data products as well as dust opacity values derived from MastCam measurements, whereas previously, the SEB has been calculated using numerical models only [4]. At each location and during the daytime, the SEB is dominated by the downwelling shortwave (SW) solar radiation (~450-500 W/m2) and the upwelling longwave (LW) radiation emitted by the surface (~300-400 W/m2). The sum of these two terms accounts for at least 70% of the net surface heating rate between 0900 and 1400 local solar time. At nighttime, the SEB is dominated by the upwelling LW radiation emitted by the surface (~50-100 W/m2) and the downwelling LW radiation from the atmosphere (~50 W/m2). When the wind speeds exceed 10 m/s at night, the turbulent heat flux can be as large as 25 W/m2, thus playing a secondary but significant role in the SEB. Finally, we estimate the amount of adsorbed water exchanged between the shallow subsurface and the atmosphere at diurnal time scales. We use subsurface temperature profiles, obtained by solving the heat conduction equation in the soil using the calculated value of I, and adsorption and desorption isotherms [5] to analyze critically the correlation between the soil wetness measured by the Dynamic Albedo of Neutrons instrument and the relative humidity measured by REMS. Acknowledgement: This research is supported by a grant from the Mars Science Laboratory and NASA Astrobiology Program Award #09-EXOB09-0050. References: [1] Martinez, G.M. et al. (2014), JGR (submitted). [2] Pelkey, S. M., and B. M. Jakosky (2002), doi:10.1006/icar.2002.6978. [3] Fergason, R., P. et al. (2012), doi:10.1007/s11214-012-9891-3. [4] Savijärvi, H., and A. Määttänen (2010), doi:10.1002/qj.650. [5] Pommerol, A. et al. (2009), doi:10.1016/j.icarus.2009.06.013.

GIS/RS-based Integrated Eco-hydrologic Modeling in the East River Basin, South China

NASA Astrophysics Data System (ADS)

Wang, Kai

Land use/cover change (LUCC) has significantly altered the hydrologic system in the East River (Dongjiang) Basin. Quantitative modeling of hydrologic impacts of LUCC is of great importance for water supply, drought monitoring and integrated water resources management. An integrated eco-hydrologic modeling system of Distributed Monthly Water Balance Model (DMWBM), Surface Energy Balance System (SEBS) was developed with aid of GIS/RS to quantify LUCC, to conduct physically-based ET (evapotranspiration) mapping and to predict hydrologic impacts of LUCC. To begin with, in order to evaluate LUCC, understand implications of LUCC and provide boundary condition for the integrated eco-hydrologic modeling, firstly the long-term vegetation dynamics was investigated based on Normalized Difference Vegetation Index (NDVI) data, and then LUCC was analyzed with post-classification methods and finally LUCC prediction was conducted based on Markov chain model. The results demonstrate that the vegetation activities decreased significantly in summer over the years. Moreover, there were significant changes in land use/cover over the past two decades. Particularly there was a sharp increase of urban and built-up area and a significant decrease of grassland and cropland. All these indicate that human activities are intensive in the East River Basin and provide valuable information for constructing scenarios for studying hydrologic impacts of LUCC. The physically-remote-sensing-based Surface Energy Balance System (SEBS) was employed to estimate areal actual ET for a large area rather than traditional point measurements . The SEBS was enhanced for application in complex vegetated area. Then the inter-comparison with complimentary ET model and distributed monthly water balance model was made to validate the enhanced SEBS (ESEBS). The application and test of ESEBS show that it has a good accuracy both monthly and annually and can be effectively applied in the East River Basin. The results of ET mapping based on ESEBS demonstrate that actual ET in the East River Basin decreases significantly in the last two decades, which is probably caused by decrease of sunshine duration. In order to effectively simulate hydrologic impact of LUCC, an integrated model of ESEBS and distributed monthly water balance model has been developed in this study. The model is capable of considering basin terrain and the spatial distribution of precipitation and soil moisture. Particularly, the model is unique in accounting for spatial and temporal variations of vegetation cover and ET, which provides a powerful tool for studying the hydrologic impacts of LUCC. The model was applied to simulate the monthly runoff for the period of 1980-1994 for model calibration and for the period of 1995-2000 for validation. The calibration and validation results show that the newly integrated model is suitable for simulating monthly runoff and studying hydrologic impacts ofLUCC in the East River Basin. Finally, the newly integrated model was firstly applied to analyze the relationship of land use and hydrologic regimes based on the land use maps in 1980 and 2000. Then the newly integrated model was applied to simulate the potential impacts of land use change on hydrologic regimes in the East River Basin under a series of hypothetical scenarios. The results show that ET has a positive relationship with Leaf Area Index (LAI) while runoff has a negative relationship with LAI in the same climatic zone, which can be elaborated by surface energy balance and water balance equation. Specifically, on an annual basis, ET of forest scenarios is larger than that of grassland or cropland scenarios. On the contrary, runoff of forest scenarios is less than that of grassland or cropland scenarios. On a monthly basis, for most of the scenarios, particularly the grassland and cropland scenarios, the most significant changes occurred in the rainy season. The results indicate that deforestation would cause increase of runoff and decrease of ET on an annual basis in the East River Basin. On a monthly basis, deforestation would cause significant decrease of ET and increase of runoff in the rainy season in the East River Basin. These results are not definitive statements as to what will happen to runoff, ET and soil moisture regimes in the East River Basin, but rather offer an insight into the plausible changes in basin hydrology due to land use change. The integrated model developed in this study and these results have significant implications for integrated water resources management and sustainable development in the East River Basin.

The 2010-2011 Revival of Jupiter's South Equatorial Belt: Perturbations of Temperatures, Clouds and Composition from Infrared Observations

NASA Technical Reports Server (NTRS)

Orton, G.; Fletcher, L.; Yanamandra-Fisher, P.; Sanchez-Lavega, A.; Perez-Hoyos, S.; Baines, K.; de Pater, I.; Wong, M.; Goetz, R.; Valkov, S.;

Assisting Bulgarian Special Educators with Competency Development Online

ERIC Educational Resources Information Center

Peterson, Rob; Herrington, Jan; Konza, Deslea; Tzvetkova-Arsova, Mira; Stefanov, Krassen

2008-01-01

Purpose: The purpose of this paper is to discuss an expansion of the Special Education Bulgaria (SEB) internet community that is required to pilot software created by the European Union's (EU's) Sixth Framework integrated project, TENCompetence. Design/methodology/approach: SEB is the product of a two-year research project designed to create a…

Health Canada/BIOTECanada Summit on regulatory and clinical topics related to subsequent entry biologics (biosimilars), Ottawa, Canada, 14 May 2012.

PubMed

Kay, Jonathan; Feagan, Brian G; Guirguis, Micheal S; Keystone, Edward C; Klein, Agnes V; Lubiniecki, Anthony S; Mould, Diane R; Nyarko, Kwasi A; Ridgway, Anthony A G; Trudeau, Maureen E; Wang, Jian

2012-11-01

In May 2012, Health Canada and other participants held a National Summit on Subsequent Entry Biologics (SEBs). Health Canada released a guidance document in March 2010 describing policy positions and data requirements for approval of SEBs. While Health Canada and health agencies in other regulatory jurisdictions are aligned on many scientific principles related to biosimilar drugs, Health Canada's specific requirements may not be widely understood by many Canadian stakeholders. The Summit provided an opportunity for education and dialog among physicians who prescribe biologics, provincial payers, and industry on the following topics: preclinical and clinical comparability studies; manufacturing and other product differences; extrapolation of indications; substitution and interchangeability of SEBs with reference biologic drugs in clinical practice; payers' current perspective; pharmacovigilance and naming. It is anticipated that the consensus reached at this meeting will further educate Canadian healthcare professionals, provincial payers, and insurers about the appropriate use of SEBs, and may be of general interest to others internationally. Copyright © 2012 The International Alliance for Biological Standardization. All rights reserved.

Organization and ELISA-Based Results of the First Proficiency Testing to Evaluate the Ability of European Union Laboratories to Detect Staphylococcal Enterotoxin Type B (SEB) in Buffer and Milk

PubMed Central

Nia, Yacine; Rodriguez, Mélanie; Zeleny, Reinhard; Herbin, Sabine; Auvray, Frédéric; Fiebig, Uwe; Avondet, Marc-André; Munoz, Amalia; Hennekinne, Jacques-Antoine

2016-01-01

The aim of this work was to organize the first proficiency test (PT) dedicated to staphylococcal enterotoxin B (SEB) detection in milk and buffer solutions. This paper describes the organization of the PT trial according to EN ISO 17043 requirements. Characterization of the SEB stock solution was performed using SDS-PAGE and SE-specific ELISA, and amino acid analysis was used to assign its protein concentration. The solution was then used to prepare six PT materials (four milk and two buffer batches) at a ng/g toxin level, which included one blank and one SEA-containing milk as specificity control. Suitable material homogeneity and stability were assessed using screening and quantitative ELISAs. Among the methods used by the participants, ELISA-based methods demonstrated their efficiency for the detection of SEB in both simple and complex matrices. The results serve as a basis for further improving the detection capabilities in expert laboratories and can therefore be considered as a contribution to biopreparedness. PMID:27649244

24 CFR 200.934 - User fee system for the technical suitability of products program.

Code of Federal Regulations, 2012 CFR

2012-04-01

... section establishes fee requirements for the issuance of Structural Engineering Bulletins (SEBs), Mechanical Engineering Bulletins (MEBs), Truss Connector Bulletins (TCBs), Area Letters of Acceptance (ALAs... Department. (i) With respect to Mechanical Engineering Bulletins (MEBs), Structural Engineering Bulletins...

24 CFR 200.934 - User fee system for the technical suitability of products program.

Code of Federal Regulations, 2013 CFR

2013-04-01

... section establishes fee requirements for the issuance of Structural Engineering Bulletins (SEBs), Mechanical Engineering Bulletins (MEBs), Truss Connector Bulletins (TCBs), Area Letters of Acceptance (ALAs... Department. (i) With respect to Mechanical Engineering Bulletins (MEBs), Structural Engineering Bulletins...

24 CFR 200.934 - User fee system for the technical suitability of products program.

Code of Federal Regulations, 2014 CFR

2014-04-01

... section establishes fee requirements for the issuance of Structural Engineering Bulletins (SEBs), Mechanical Engineering Bulletins (MEBs), Truss Connector Bulletins (TCBs), Area Letters of Acceptance (ALAs... Department. (i) With respect to Mechanical Engineering Bulletins (MEBs), Structural Engineering Bulletins...

24 CFR 200.934 - User fee system for the technical suitability of products program.

Code of Federal Regulations, 2011 CFR

2011-04-01

... section establishes fee requirements for the issuance of Structural Engineering Bulletins (SEBs), Mechanical Engineering Bulletins (MEBs), Truss Connector Bulletins (TCBs), Area Letters of Acceptance (ALAs... Department. (i) With respect to Mechanical Engineering Bulletins (MEBs), Structural Engineering Bulletins...

Stable phantom materials for ultrasound and optical imaging.

PubMed

Cabrelli, Luciana C; Pelissari, Pedro I B G B; Deana, Alessandro M; Carneiro, Antonio A O; Pavan, Theo Z

2017-01-21

Phantoms mimicking the specific properties of biological tissues are essential to fully characterize medical devices. Water-based materials are commonly used to manufacture phantoms for ultrasound and optical imaging techniques. However, these materials have disadvantages, such as easy degradation and low temporal stability. In this study, we propose an oil-based new tissue-mimicking material for ultrasound and optical imaging, with the advantage of presenting low temporal degradation. A styrene-ethylene/butylene-styrene (SEBS) copolymer in mineral oil samples was made varying the SEBS concentration between 5%-15%, and low-density polyethylene (LDPE) between 0%-9%. Acoustic properties, such as the speed of sound and the attenuation coefficient, were obtained using frequencies ranging from 1-10 MHz, and were consistent with that of soft tissues. These properties were controlled varying SEBS and LDPE concentration. To characterize the optical properties of the samples, the diffuse reflectance and transmittance were measured. Scattering and absorption coefficients ranging from 400 nm-1200 nm were calculated for each compound. SEBS gels are a translucent material presenting low optical absorption and scattering coefficients in the visible region of the spectrum, but the presence of LDPE increased the turbidity. Adding LDPE increased the absorption and scattering of the phantom materials. Ultrasound and photoacoustic images of a heterogeneous phantom made of LDPE/SEBS containing a spherical inclusion were obtained. Annatto dye was added to the inclusion to enhance the optical absorbance. The results suggest that copolymer gels are promising for ultrasound and optical imaging, making them also potentially useful for photoacoustic imaging.

Stable phantom materials for ultrasound and optical imaging

NASA Astrophysics Data System (ADS)

Cabrelli, Luciana C.; Pelissari, Pedro I. B. G. B.; Deana, Alessandro M.; Carneiro, Antonio A. O.; Pavan, Theo Z.

2017-01-01

Phantoms mimicking the specific properties of biological tissues are essential to fully characterize medical devices. Water-based materials are commonly used to manufacture phantoms for ultrasound and optical imaging techniques. However, these materials have disadvantages, such as easy degradation and low temporal stability. In this study, we propose an oil-based new tissue-mimicking material for ultrasound and optical imaging, with the advantage of presenting low temporal degradation. A styrene-ethylene/butylene-styrene (SEBS) copolymer in mineral oil samples was made varying the SEBS concentration between 5%-15%, and low-density polyethylene (LDPE) between 0%-9%. Acoustic properties, such as the speed of sound and the attenuation coefficient, were obtained using frequencies ranging from 1-10 MHz, and were consistent with that of soft tissues. These properties were controlled varying SEBS and LDPE concentration. To characterize the optical properties of the samples, the diffuse reflectance and transmittance were measured. Scattering and absorption coefficients ranging from 400 nm-1200 nm were calculated for each compound. SEBS gels are a translucent material presenting low optical absorption and scattering coefficients in the visible region of the spectrum, but the presence of LDPE increased the turbidity. Adding LDPE increased the absorption and scattering of the phantom materials. Ultrasound and photoacoustic images of a heterogeneous phantom made of LDPE/SEBS containing a spherical inclusion were obtained. Annatto dye was added to the inclusion to enhance the optical absorbance. The results suggest that copolymer gels are promising for ultrasound and optical imaging, making them also potentially useful for photoacoustic imaging.

Simultaneous integrated vs. sequential boost in VMAT radiotherapy of high-grade gliomas.

PubMed

Farzin, Mostafa; Molls, Michael; Astner, Sabrina; Rondak, Ina-Christine; Oechsner, Markus

2015-12-01

In 20 patients with high-grade gliomas, we compared two methods of planning for volumetric-modulated arc therapy (VMAT): simultaneous integrated boost (SIB) vs. sequential boost (SEB). The investigation focused on the analysis of dose distributions in the target volumes and the organs at risk (OARs). After contouring the target volumes [planning target volumes (PTVs) and boost volumes (BVs)] and OARs, SIB planning and SEB planning were performed. The SEB method consisted of two plans: in the first plan the PTV received 50 Gy in 25 fractions with a 2-Gy dose per fraction. In the second plan the BV received 10 Gy in 5 fractions with a dose per fraction of 2 Gy. The doses of both plans were summed up to show the total doses delivered. In the SIB method the PTV received 54 Gy in 30 fractions with a dose per fraction of 1.8 Gy, while the BV received 60 Gy in the same fraction number but with a dose per fraction of 2 Gy. All of the OARs showed higher doses (Dmax and Dmean) in the SEB method when compared with the SIB technique. The differences between the two methods were statistically significant in almost all of the OARs. Analysing the total doses of the target volumes we found dose distributions with similar homogeneities and comparable total doses. Our analysis shows that the SIB method offers advantages over the SEB method in terms of sparing OARs.

[An operational remote sensing algorithm of land surface evapotranspiration based on NOAA PAL dataset].

PubMed

Hou, Ying-Yu; He, Yan-Bo; Wang, Jian-Lin; Tian, Guo-Liang

2009-10-01

Based on the time series 10-day composite NOAA Pathfinder AVHRR Land (PAL) dataset (8 km x 8 km), and by using land surface energy balance equation and "VI-Ts" (vegetation index-land surface temperature) method, a new algorithm of land surface evapotranspiration (ET) was constructed. This new algorithm did not need the support from meteorological observation data, and all of its parameters and variables were directly inversed or derived from remote sensing data. A widely accepted ET model of remote sensing, i. e., SEBS model, was chosen to validate the new algorithm. The validation test showed that both the ET and its seasonal variation trend estimated by SEBS model and our new algorithm accorded well, suggesting that the ET estimated from the new algorithm was reliable, being able to reflect the actual land surface ET. The new ET algorithm of remote sensing was practical and operational, which offered a new approach to study the spatiotemporal variation of ET in continental scale and global scale based on the long-term time series satellite remote sensing images.

Cytokine secretion induced by superantigens in peripheral blood mononuclear cells, lamina propria lymphocytes, and intraepithelial lymphocytes.

PubMed Central

Sperber, K; Silverstein, L; Brusco, C; Yoon, C; Mullin, G E; Mayer, L

1995-01-01

Superantigens are potent inducers of T-cell proliferation and induce a broad range of cytokines, including tumor necrosis factor (TNF), gamma interferon, and interleukin 2 (IL-2). In the present study, we compared the abilities of different staphylococcal superantigens (staphylococcal enterotoxin B [SEB], staphylococcal enterotoxin E [SEE], and toxic shock syndrome toxin 1 [TSST-1]) to stimulate distinct cytokine profiles in peripheral blood mononuclear cells (PBMC), lamina propria lymphocytes (LPL), and intraepithelial lymphocytes (IEL). One million PBMC, LPL, and IEL were stimulated with various concentrations of superantigen (10 to 0.001 ng/ml) for 24, 48, and 72 h. Maximum cytokine production by PBMC, LPL, and IEL was observed for all three superantigens at 48 h at a concentration of 1 ng/ml. In PBMC, SEE and TSST-1 stimulated more IL-2 and gamma interferon than SEB. SEE and TSST-1 also stimulated more TNF and IL-4 production than SEB. In contrast, SEB stimulated more IL-6 than either SEE or TSST-1. In LPL, there was no SEE-induced IL-2 or IL-4 production, but IL-6, TNF, and gamma interferon were induced. SEB similarly induced no IL-2 or gamma interferon from the LPL, but IL-4, IL-6, and TNF were detected. TSST-1 stimulation of LPL resulted in IL-2 and TNF production but no IL-4, IL-6, or gamma interferon. In IEL, SEE induced no IL-2, IL-4, or gamma interferon but produced IL-6 and TNF, while SEB stimulation resulted in no IL-2 or gamma interferon but did result in detectable IL-4, IL-6, and TNF. Taken together, these data indicate that there are significant differences in the cytokine profiles induced by superantigens in LPL and IEL compared with those in PBMC, and these differences may relate to differences in activation requirements. PMID:7583927

Deriving hourly evapotranspiration (ET) rates with SEBS: A lysimetric evaluation

USDA-ARS?s Scientific Manuscript database

Numerous energy balance (EB) algorithms have been developed to use remote sensing data for mapping evapotranspiration (ET) on a regional basis. Adopting any single or combination of these models for an operational ET remote sensing program requires a thorough evaluation. The Surface Energy Balance S...

24 CFR 200.934 - User fee system for the technical suitability of products program.

Code of Federal Regulations, 2010 CFR

2010-04-01

... COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT GENERAL INTRODUCTION TO FHA PROGRAMS Minimum Property... section establishes fee requirements for the issuance of Structural Engineering Bulletins (SEBs), Mechanical Engineering Bulletins (MEBs), Truss Connector Bulletins (TCBs), Area Letters of Acceptance (ALAs...

Superantigens Modulate Bacterial Density during Staphylococcus aureus Nasal Colonization

PubMed Central

Xu, Stacey X.; Kasper, Katherine J.; Zeppa, Joseph J.; McCormick, John K.

2015-01-01

Superantigens (SAgs) are potent microbial toxins that function to activate large numbers of T cells in a T cell receptor (TCR) Vβ-specific manner, resulting in excessive immune system activation. Staphylococcus aureus possesses a large repertoire of distinct SAgs, and in the context of host-pathogen interactions, staphylococcal SAg research has focused primarily on the role of these toxins in severe and invasive diseases. However, the contribution of SAgs to colonization by S. aureus remains unclear. We developed a two-week nasal colonization model using SAg-sensitive transgenic mice expressing HLA-DR4, and evaluated the role of SAgs using two well-studied stains of S. aureus. S. aureus Newman produces relatively low levels of staphylococcal enterotoxin A (SEA), and although we did not detect significant TCR-Vβ specific changes during wild-type S. aureus Newman colonization, S. aureus Newman Δsea established transiently higher bacterial loads in the nose. S. aureus COL produces relatively high levels of staphylococcal enterotoxin B (SEB), and colonization with wild-type S. aureus COL resulted in clear Vβ8-specific T cell skewing responses. S. aureus COL Δseb established consistently higher bacterial loads in the nose. These data suggest that staphylococcal SAgs may be involved in regulating bacterial densities during nasal colonization. PMID:26008236

High School Students' Informal Reasoning Regarding a Socio-Scientific Issue, with Relation to Scientific Epistemological Beliefs and Cognitive Structures

ERIC Educational Resources Information Center

Wu, Ying-Tien; Tsai, Chin-Chung

2011-01-01

This study investigated the relationship among 68 high school students' scientific epistemological beliefs (SEBs), cognitive structures regarding nuclear power usage, and their informal reasoning regarding this issue. Moreover, the ability of students' SEBs as well as their cognitive structures for predicting their informal reasoning regarding…

Self-Efficacy Beliefs amongst Parents of Young Children: Validation of a Self-Report Measure

ERIC Educational Resources Information Center

Meunier, Jean-Christophe; Roskam, Isabelle

2009-01-01

The self-efficacy belief (SEB) concept is discussed in the context of parenting. A questionnaire, the "Echelle Globale du Sentiment de Competence Parentale" (EGSCP), assessing several domain-specific SEBs and three related cognitive constructs, was developed with 705 French-speaking parents of 3- to 7-year-old children. The EGSCP displayed good…

Reduction of Noise from Disc Brake Systems Using Composite Friction Materials Containing Thermoplastic Elastomers (TPEs)

NASA Astrophysics Data System (ADS)

Masoomi, Mohsen; Katbab, Ali Asghar; Nazockdast, Hossein

2006-09-01

Attempts have been made for the first time to prepare a friction material with the characteristic of thermal sensitive modulus, by the inclusion of thermoplastic elastomers (TPE) as viscoelastic polymeric materials into the formulation in order to the increase the damping behavior of the cured friction material. Styrene butadiene styrene (SBS), styrene ethylene butylene styrene (SEBS) and nitrile rubber/polyvinyl chloride (NBR/PVC) blend system were used as TPE materials. In order to evaluate the viscoelastic parameters such as loss factor (tan δ) and storage modulus (E‧) for the friction material, dynamic mechanical analyzer (DMA) were used. Natural frequencies and mode shapes of friction material and brake disc were determined by modal analysis. However, NBR/PVC and SEBS were found to be much more effective in damping behavior. The results from this comparative study suggest that the damping characteristics of commercial friction materials can be strongly affected by the TPE ingredients. This investigation also confirmed that the specimens with high TPE content had low noise propensity.

Modelling the climate and surface mass balance of polar ice sheets using RACMO2 - Part 1: Greenland (1958-2016)

NASA Astrophysics Data System (ADS)

Noël, Brice; van de Berg, Willem Jan; Melchior van Wessem, J.; van Meijgaard, Erik; van As, Dirk; Lenaerts, Jan T. M.; Lhermitte, Stef; Kuipers Munneke, Peter; Smeets, C. J. P. Paul; van Ulft, Lambertus H.; van de Wal, Roderik S. W.; van den Broeke, Michiel R.

2018-03-01

We evaluate modelled Greenland ice sheet (GrIS) near-surface climate, surface energy balance (SEB) and surface mass balance (SMB) from the updated regional climate model RACMO2 (1958-2016). The new model version, referred to as RACMO2.3p2, incorporates updated glacier outlines, topography and ice albedo fields. Parameters in the cloud scheme governing the conversion of cloud condensate into precipitation have been tuned to correct inland snowfall underestimation: snow properties are modified to reduce drifting snow and melt production in the ice sheet percolation zone. The ice albedo prescribed in the updated model is lower at the ice sheet margins, increasing ice melt locally. RACMO2.3p2 shows good agreement compared to in situ meteorological data and point SEB/SMB measurements, and better resolves the spatial patterns and temporal variability of SMB compared with the previous model version, notably in the north-east, south-east and along the K-transect in south-western Greenland. This new model version provides updated, high-resolution gridded fields of the GrIS present-day climate and SMB, and will be used for projections of the GrIS climate and SMB in response to a future climate scenario in a forthcoming study.

Utility of remote sensing-based surface energy balance models to track water stress in rain-fed switchgrass under dry and wet conditions

USDA-ARS?s Scientific Manuscript database

The ability of remote sensing-based surface energy balance (SEB) models to track water stress in rain-fed switchgrass has not been explored yet. In this paper, the theoretical framework of crop water stress index (CWSI) was utilized to estimate CWSI in rain-fed switchgrass (Panicum virgatum L.) usin...

Polypropylene/Short Glass Fibers Composites: Effects of Coupling Agents on Mechanical Properties, Thermal Behaviors, and Morphology

PubMed Central

Lin, Jia-Horng; Huang, Chien-Lin; Liu, Chi-Fan; Chen, Chih-Kuang; Lin, Zheng-Ian; Lou, Ching-Wen

2015-01-01

This study uses the melt compounding method to produce polypropylene (PP)/short glass fibers (SGF) composites. PP serves as matrix while SGF serves as reinforcement. Two coupling agents, maleic anhydride grafted polypropylene, (PP-g-MA) and maleic anhydride grafted styrene-ethylene-butylene-styrene block copolymer (SEBS-g-MA) are incorporated in the PP/SGF composites during the compounding process, in order to improve the interfacial adhesion and create diverse desired properties of the composites. According to the mechanical property evaluations, increasing PP-g-MA as a coupling agent provides the composites with higher tensile, flexural, and impact properties. In contrast, increasing SEBS-g-MA as a coupling agent provides the composites with decreasing tensile and flexural strengths, but also increasing impact strength. The DSC results indicate that using either PP-g-MA or SEBS-g-MA as the coupling agent increases the crystallization temperature. However, the melting temperature of PP barely changes. The spherulitic morphology results show that PP has a smaller spherulite size when it is processed with PP-g-MA or SEBS-g-MA as the coupling agent. The SEM results indicate that SGF is evenly distributed in PP matrices, but there are distinct voids between these two materials, indicating a poor interfacial adhesion. After PP-g-MA or SEBS-g-MA is incorporated, SGF can be encapsulated by PP, and the voids between them are fewer and indistinctive. This indicates that the coupling agents can effectively improve the interfacial compatibility between PP and SGF, and as a result improves the diverse properties of PP/SGF composites. PMID:28793710

High School Students' Scientific Epistemological Beliefs, Motivation in Learning Science, and Their Relationships: A Comparative Study within the Chinese Culture

ERIC Educational Resources Information Center

Lin, Tzung-Jin; Deng, Feng; Chai, Ching Sing; Tsai, Chin-Chung

2013-01-01

This study explored the differences in high school students' scientific epistemological beliefs (SEBs), motivation in learning science (MLS), and the different relationships between them in Taiwan and China. 310 Taiwanese and 302 Chinese high school students' SEBs and MLS were assessed quantitatively. Taiwanese students generally were more prone…

Associations between Expressive and Receptive Language and Internalizing and Externalizing Behaviours in a Community-Based Prospective Study of Slow-to-Talk Toddlers

ERIC Educational Resources Information Center

Conway, Laura J.; Levickis, Penny A.; Mensah, Fiona; McKean, Cristina; Smith, Kylie; Reilly, Sheena

2017-01-01

Background: Evidence suggests that language and social, emotional and behavioural (SEB) difficulties are associated in children and adolescents. When these associations emerge and whether they differ by language or SEB difficulty profile is unclear. This knowledge is crucial to guide prevention and intervention programmes for children with…

Application of LC-MS/MS MRM to Determine Staphylococcal Enterotoxins (SEB and SEA) in Milk.

PubMed

Andjelkovic, Mirjana; Tsilia, Varvara; Rajkovic, Andreja; De Cremer, Koen; Van Loco, Joris

2016-04-20

Staphylococcus aureus is one of the important aetiological agents of food intoxications in Europe and can cause gastro-enteritis through the production of various staphylococcal enterotoxins (SEs) in foods. Due to their stability and ease of production and dissemination, some SEs have also been studied as potential agents for bioterrorism. Therefore, specific and accurate analytical tools are required to detect and quantify SEs. Online solid-phase extraction liquid chromatography electrospray ionization tandem mass spectrometry (online SPE-LC-ESI-MS/MS) based on multiple reaction monitoring (MRM) was used to detect and quantify two types of SE (A and B) spiked in milk and buffer solution. SE extraction and concentration was performed according to the European Screening Method developed by the European Reference Laboratory for Coagulase Positive Staphylococci. Trypsin digests were screened for the presence of SEs using selected proteotypic heavy-labeled peptides as internal standards. SEA and SEB were successfully detected in milk samples using LC-MS/MS in MRM mode. The selected SE peptides were proteotypic for each toxin, allowing the discrimination of SEA and SEB in a single run. The detection limit of SEA and SEB was approximately 8 and 4 ng/g, respectively.

Reduction of Non-Specific Protein Adsorption Using Poly(ethylene) Glycol (PEG) Modified Polyacrylate Hydrogels In Immunoassays for Staphylococcal Enterotoxin B Detection

PubMed Central

Charles, Paul T.; Stubbs, Veronte R.; Soto, Carissa M.; Martin, Brett D.; White, Brandy J.; Taitt, Chris R.

2009-01-01

Three PEG molecules (PEG-methacrylate, -diacrylate and -dimethacrylate) were incorporated into galactose-based polyacrylate hydrogels and their relative abilities to reduce non-specific protein adsorption in immunoassays were determined. Highly crosslinked hydrogels containing amine-terminated functionalities were formed and used to covalently attach antibodies specific for staphylococcal enterotoxin B (SEB). Patterned arrays of immobilized antibodies in the PEG-modified hydrogels were created with a PDMS template containing micro-channels for use in sandwich immunoassays to detect SEB. Different concentrations of the toxin were applied to the hydrogel arrays, followed with a Cy3-labeled tracer antibody specific for the two toxins. Fluorescence laser scanning confocal microscopy of the tracer molecules provided both qualitative and quantitative measurements on the detection sensitivity and the reduction in non-specific binding as a result of PEG incorporation. Results showed the PEG-modified hydrogel significantly reduced non-specific protein binding with a detection limit for SEB of 1 ng/mL. Fluorescence signals showed a 10-fold decrease in the non-specific binding and a 6-fold increase in specific binding of SEB. PMID:22389622

Sulfonated Styrene-(ethylene-co-butylene)-styrene/Montmorillonite Clay Nanocomposites: Synthesis, Morphology, and Properties

PubMed Central

2008-01-01

Sulfonated styrene-(ethylene-butylene)-styrene triblock copolymer (SSEBS) was synthesized by reaction of acetyl sulfate with SEBS. SSESB-clay nanocomposites were then prepared from hydrophilic Na-montmorillonite (MT) and organically (quaternary amine) modified hydrophobic nanoclay (OMT) at very low loading. SEBS did not show improvement in properties with MT-based nanocomposites. On sulfonation (3 and 6 weight%) of SEBS, hydrophilic MT clay-based nanocomposites exhibited better mechanical, dynamic mechanical, and thermal properties, and also controlled water–methanol mixture uptake and permeation and AC resistance. Microstructure determined by X-ray diffraction, atomic force microscopy, and transmission electron microscopy due to better dispersion of MT nanoclay particles and interaction of MT with SSEBS matrix was responsible for this effect. The resulting nanocomposites have potential as proton transfer membranes for Fuel Cell applications.

Quality Systems Manual (QSM) Version 5: Update

DTIC Science & Technology

2012-03-01

Rei Mao; Charles Stoner  Air Force: John (Seb) Gillette  DOE: Joe Pardue; Todd Hardt  Contractor: Alyssa Wingard Questions ??? We have answers* Do...labs must be approved by appropriate DOE representative • Outsourced QS elements (such as data review) must comply with the standard and are subject to

Forcing and Responses of the Surface Energy Budget at Summit, Greenland

NASA Astrophysics Data System (ADS)

Miller, Nathaniel B.

Energy exchange at the Greenland Ice Sheet surface governs surface temperature variability, a factor critical for representing increasing surface melt extent, which portends a rise in global sea level. A comprehensive set of cloud, tropospheric, near-surface and sub-surface measurements at Summit Station is utilized to determine the driving forces and subsequent responses of the surface energy budget (SEB). This budget includes radiative, turbulent, and ground heat fluxes, and ultimately controls the evolution of surface temperature. At Summit Station, clouds radiatively warm the surface in all months with an annual average cloud radiative forcing value of 33 W m -2, largely driven by the occurrence of liquid-bearing clouds. The magnitude of the surface temperature response is dependent on how turbulent and ground heat fluxes modulate changes to radiative forcing. Relationships between forcing terms and responding surface fluxes show that changes in the upwelling longwave radiation compensate for 65-85% (50- 60%) of the total change in radiative forcing in the winter (summer). The ground heat flux is the second largest response term (16% annually), especially during winter. Throughout the annual cycle, the sensible heat flux response is comparatively constant (9%) and latent heat flux response is only 1.5%, becoming more of a factor in modulating surface temperature responses during the summer. Combining annual cycles of these responses with cloud radiative forcing results, clouds warm the surface by an estimated 7.8°C annually. A reanalysis product (ERA-I), operational model (CFSv2), and climate model (CESM) are evaluated utilizing the comprehensive set of SEB observations and process-based relationships. Annually, surface temperatures in each model are warmer than observed with overall poor representation of the coldest surface temperatures. Process-based relationships between different SEB flux terms offer insight into how well a modeling framework represents physical processes and the ability to distinguish errors in forcing versus those in physical representation. Such relationships convey that all three models underestimate the response of surface temperatures to changes in radiative forcing. These results provide a method to expose model deficiencies and indicate the importance of representing surface, sub-surface and boundary-layer processes when portraying cloud impacts on surface temperature variability.

The Use of Multiplex PCR to Determine the Prevalence of Enterotoxigenic Staphylococcus aureus Isolated from Raw Milk, Feta Cheese, and Hand Swabs.

PubMed

Zeinhom, Mohamed M A; Abdel-Latef, Gihan K; Jordan, Kieran

2015-12-01

Staphylococcus aureus (S. aureus) can cause mastitis in cattle and, therefore, can be present in milk. This study was undertaken to determine the prevalence of coagulase positive S. aureus and its enterotoxin genes sea, seb, and sec in isolates recovered from raw milk, feta cheese, and human hand swabs of milk and cheese handlers in Beni-Suef province, Egypt. A total of 100 samples of raw milk and 50 samples of pasteurized-milk feta cheese were collected. In addition, 50 hand swabs from milk handlers and 25 hand swabs from cheese handlers were examined for the presence of coagulase positive S. aureus. The isolates were characterized by multiplex PCR for detection of sea, seb, and sec genes, and for resistance to 5 classes of commonly used antibiotics. Twelve (12/100), 12 (6/50), and 17% (13/75) of milk, cheese, and hand swab samples, respectively, were positive for coagulase positive S. aureus. One isolate was obtained from each positive sample (31 isolates), and none contained genes for SEA or SEC production. Twenty-five percent, 33%, and 31%, respectively, of the isolates contained the genes for SEB, resulting in 3%, 4%, and 5% of samples being positive for toxin producing coagulase positive S. aureus, respectively. At least one isolate was resistant to each of the antibiotics tested. Despite the low potential for SEB production shown, preventative measures, such as maintenance of the cold-chain and good hygienic practices should be implemented to further reduce the potential risk to public health from SEB, and to reduce the spread of antimicrobial resistance. © 2015 Institute of Food Technologists®

Health Promotion Outcomes of a Newly Developed Elastic Band Exercise Program for Older Adults in the Community: A Pilot Test.

PubMed

Chan, Shu-Ya; Kuo, Chang-Chih; Chen, Kuei-Min; Tseng, Wei-Shyuan; Huang, Hsin-Ting; Li, Chun-Huw

2016-06-01

Studies indicate that the incidence of disease, the mortality rate, and medical costs are significantly higher in people aged 65 years and over who do not engage in physical activities than in their peers who do engage in these activities. Therefore, promoting appropriate physical activity among older adults in the community is essential to delaying the health implications of aging. This pilot test was developed to assess the effectiveness of a newly developed Senior Elastic Band (SEB) exercise program on the health of older adults in community care stations. A quasiexperimental design was used. A convenience sample of 20 participants from a community care station was recruited. The SEB intervention included three phases (warm-up, aerobic motion, and static stretching) and was conducted three times per week, 40 minutes per session for 1 month. Twelve health indicators in three categories (functional fitness, self-perceived health status, and sleep quality) were examined before and immediately after 1 month of SEB exercises. Participants showed improved performance at the end of the 1-month study for the following indicators: lung capacity, cardiopulmonary fitness, upper and lower body flexibilities, upper limb muscle power, lower limb muscle endurance, and self-perceived physical health status (all ps < .05). No significant differences were identified for the other indicators. The SEB exercise program shows preliminary and promising effects on improving the health of older adults in a community care station. Healthcare professionals who work with older adults living in the community may consider the SEB exercise program as a health promotion modality to recommend and implement with this population. However, we recommend further testing the long-term effects of this program on a larger population.

Application of a SERS-based lateral flow immunoassay strip for the rapid and sensitive detection of staphylococcal enterotoxin B

NASA Astrophysics Data System (ADS)

Hwang, Joonki; Lee, Sangyeop; Choo, Jaebum

2016-06-01

A novel surface-enhanced Raman scattering (SERS)-based lateral flow immunoassay (LFA) biosensor was developed to resolve problems associated with conventional LFA strips (e.g., limits in quantitative analysis and low sensitivity). In our SERS-based biosensor, Raman reporter-labeled hollow gold nanospheres (HGNs) were used as SERS detection probes instead of gold nanoparticles. With the proposed SERS-based LFA strip, the presence of a target antigen can be identified through a colour change in the test zone. Furthermore, highly sensitive quantitative evaluation is possible by measuring SERS signals from the test zone. To verify the feasibility of the SERS-based LFA strip platform, an immunoassay of staphylococcal enterotoxin B (SEB) was performed as a model reaction. The limit of detection (LOD) for SEB, as determined with the SERS-based LFA strip, was estimated to be 0.001 ng mL-1. This value is approximately three orders of magnitude more sensitive than that achieved with the corresponding ELISA-based method. The proposed SERS-based LFA strip sensor shows significant potential for the rapid and sensitive detection of target markers in a simplified manner.A novel surface-enhanced Raman scattering (SERS)-based lateral flow immunoassay (LFA) biosensor was developed to resolve problems associated with conventional LFA strips (e.g., limits in quantitative analysis and low sensitivity). In our SERS-based biosensor, Raman reporter-labeled hollow gold nanospheres (HGNs) were used as SERS detection probes instead of gold nanoparticles. With the proposed SERS-based LFA strip, the presence of a target antigen can be identified through a colour change in the test zone. Furthermore, highly sensitive quantitative evaluation is possible by measuring SERS signals from the test zone. To verify the feasibility of the SERS-based LFA strip platform, an immunoassay of staphylococcal enterotoxin B (SEB) was performed as a model reaction. The limit of detection (LOD) for SEB, as determined with the SERS-based LFA strip, was estimated to be 0.001 ng mL-1. This value is approximately three orders of magnitude more sensitive than that achieved with the corresponding ELISA-based method. The proposed SERS-based LFA strip sensor shows significant potential for the rapid and sensitive detection of target markers in a simplified manner. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr07243c

The WACMOS-ET project – Part 1: Tower-scale evaluation of four remote-sensing-based evapotranspiration algorithms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michel, D.; Jimenez, C.; Miralles, D. G.

The WAter Cycle Multi-mission Observation Strategy – EvapoTranspiration (WACMOS-ET) project has compiled a forcing data set covering the period 2005–2007 that aims to maximize the exploitation of European Earth Observations data sets for evapotranspiration (ET) estimation. The data set was used to run four established ET algorithms: the Priestley–Taylor Jet Propulsion Laboratory model (PT-JPL), the Penman–Monteith algorithm from the MODerate resolution Imaging Spectroradiometer (MODIS) evaporation product (PM-MOD), the Surface Energy Balance System (SEBS) and the Global Land Evaporation Amsterdam Model (GLEAM). In addition, in situ meteorological data from 24 FLUXNET towers were used to force the models, with results from both forcing sets compared tomore » tower-based flux observations. Model performance was assessed on several timescales using both sub-daily and daily forcings. The PT-JPL model and GLEAM provide the best performance for both satellite- and tower-based forcing as well as for the considered temporal resolutions. Simulations using the PM-MOD were mostly underestimated, while the SEBS performance was characterized by a systematic overestimation. In general, all four algorithms produce the best results in wet and moderately wet climate regimes. In dry regimes, the correlation and the absolute agreement with the reference tower ET observations were consistently lower. While ET derived with in situ forcing data agrees best with the tower measurements ( R 2 = 0.67), the agreement of the satellite-based ET estimates is only marginally lower ( R 2 = 0.58). Results also show similar model performance at daily and sub-daily (3-hourly) resolutions. Overall, our validation experiments against in situ measurements indicate that there is no single best-performing algorithm across all biome and forcing types. In conclusion, an extension of the evaluation to a larger selection of 85 towers (model inputs resampled to a common grid to facilitate global estimates) confirmed the original findings.« less

The WACMOS-ET project – Part 1: Tower-scale evaluation of four remote-sensing-based evapotranspiration algorithms

DOE PAGES

Michel, D.; Jimenez, C.; Miralles, D. G.; ...

2016-02-23

The WAter Cycle Multi-mission Observation Strategy – EvapoTranspiration (WACMOS-ET) project has compiled a forcing data set covering the period 2005–2007 that aims to maximize the exploitation of European Earth Observations data sets for evapotranspiration (ET) estimation. The data set was used to run four established ET algorithms: the Priestley–Taylor Jet Propulsion Laboratory model (PT-JPL), the Penman–Monteith algorithm from the MODerate resolution Imaging Spectroradiometer (MODIS) evaporation product (PM-MOD), the Surface Energy Balance System (SEBS) and the Global Land Evaporation Amsterdam Model (GLEAM). In addition, in situ meteorological data from 24 FLUXNET towers were used to force the models, with results from both forcing sets compared tomore » tower-based flux observations. Model performance was assessed on several timescales using both sub-daily and daily forcings. The PT-JPL model and GLEAM provide the best performance for both satellite- and tower-based forcing as well as for the considered temporal resolutions. Simulations using the PM-MOD were mostly underestimated, while the SEBS performance was characterized by a systematic overestimation. In general, all four algorithms produce the best results in wet and moderately wet climate regimes. In dry regimes, the correlation and the absolute agreement with the reference tower ET observations were consistently lower. While ET derived with in situ forcing data agrees best with the tower measurements ( R 2 = 0.67), the agreement of the satellite-based ET estimates is only marginally lower ( R 2 = 0.58). Results also show similar model performance at daily and sub-daily (3-hourly) resolutions. Overall, our validation experiments against in situ measurements indicate that there is no single best-performing algorithm across all biome and forcing types. In conclusion, an extension of the evaluation to a larger selection of 85 towers (model inputs resampled to a common grid to facilitate global estimates) confirmed the original findings.« less

Surface energy budget and turbulent fluxes at Arctic terrestrial sites

NASA Astrophysics Data System (ADS)

Grachev, Andrey; Persson, Ola; Uttal, Taneil; Konopleva-Akish, Elena; Crepinsek, Sara; Cox, Christopher; Fairall, Christopher; Makshtas, Alexander; Repina, Irina

2017-04-01

Determination of the surface energy budget (SEB) and all SEB components at the air-surface interface are required in a wide variety of applications including atmosphere-land/snow simulations and validation of the surface fluxes predicted by numerical models over different spatial and temporal scales. Here, comparisons of net surface energy budgets at two Arctic sites are made using long-term near-continuous measurements of hourly averaged surface fluxes (turbulent, radiation, and soil conduction). One site, Eureka (80.0 N; Nunavut, Canada), is located in complex topography near a fjord about 200 km from the Arctic Ocean. The other site, Tiksi (71.6 N; Russian East Siberia), is located on a relatively flat coastal plain less than 1 km from the shore of Tiksi Bay, a branch of the Arctic Ocean. We first analyzed diurnal and annual cycles of basic meteorological parameters and key SEB components at these locations. Although Eureka and Tiksi are located on different continents and at different latitudes, the annual course of the surface meteorology and SEB components are qualitatively similar. Surface energy balance closure is a formulation of the conservation of energy principle. Our direct measurements of energy balance for both Arctic sites show that the sum of the turbulent sensible and latent heat fluxes and the ground (conductive) heat flux systematically underestimate the net radiation by about 25-30%. This lack of energy balance closure is a fundamental and pervasive problem in micrometeorology. We discuss a variety of factors which may be responsible for the lack of SEB closure. In particular, various storage terms (e.g., air column energy storage due to radiative and/or sensible heat flux divergence, ground heat storage above the soil flux plate, energy used in photosynthesis, canopy biomass heat storage). For example, our observations show that the photosynthesis storage term is relatively small (about 1-2% of the net radiation), but about 8-12% of the imbalance magnitude. All turbulent fluxes are highly correlated with net radiation because this balance between solar and longwave radiation is the principal energy source for daytime surface warming, evaporation, and photosynthesis. We find that turbulent fluxes of carbon dioxide and sensible heat are closely linked and, on average, change sign synchronously during the diurnal and annual cycles. The work is supported by the NOAA Climate Program Office, the U.S. National Science Foundation (NSF) with award ARC 11-07428, and by the U.S. Civilian Research & Development Foundation (CRDF) with award RUG1-2976-ST-10.

Pilot Scale Production and Testing of a Recombinant Staphylococcal Enterotoxin (SEB) Triple Mutant

DTIC Science & Technology

2017-09-01

1 PILOT-SCALE PRODUCTION AND TESTING OF A RECOMBINANT STAPHYLOCOCCAL ENTEROTOXIN (SEB) TRIPLE MUTANT ECBC...Disclaimer The findings in this report are not to be construed as an official Department of the Army position unless so designated by other authorizing...TYPE Final 3. DATES COVERED (From - To) Mar 2010 – Dec 2011 4. TITLE AND SUBTITLE Pilot-Scale Production and Testing of a Recombinant

Transcriptome analysis of Aspergillus niger grown on sugarcane bagasse

PubMed Central

2011-01-01

Background Considering that the costs of cellulases and hemicellulases contribute substantially to the price of bioethanol, new studies aimed at understanding and improving cellulase efficiency and productivity are of paramount importance. Aspergillus niger has been shown to produce a wide spectrum of polysaccharide hydrolytic enzymes. To understand how to improve enzymatic cocktails that can hydrolyze pretreated sugarcane bagasse, we used a genomics approach to investigate which genes and pathways are transcriptionally modulated during growth of A. niger on steam-exploded sugarcane bagasse (SEB). Results Herein we report the main cellulase- and hemicellulase-encoding genes with increased expression during growth on SEB. We also sought to determine whether the mRNA accumulation of several SEB-induced genes encoding putative transporters is induced by xylose and dependent on glucose. We identified 18 (58% of A. niger predicted cellulases) and 21 (58% of A. niger predicted hemicellulases) cellulase- and hemicellulase-encoding genes, respectively, that were highly expressed during growth on SEB. Conclusions Degradation of sugarcane bagasse requires production of many different enzymes which are regulated by the type and complexity of the available substrate. Our presently reported work opens new possibilities for understanding sugarcane biomass saccharification by A. niger hydrolases and for the construction of more efficient enzymatic cocktails for second-generation bioethanol. PMID:22008461

Moist convection and the 2010-2011 revival of Jupiter's South Equatorial Belt

NASA Astrophysics Data System (ADS)

Fletcher, Leigh N.; Orton, G. S.; Rogers, J. H.; Giles, R. S.; Payne, A. V.; Irwin, P. G. J.; Vedovato, M.

2017-04-01

The transformation of Jupiter's South Equatorial Belt (SEB) from its faded, whitened state in 2009-2010 (Fletcher et al., 2011b) to its normal brown appearance is documented via comparisons of thermal-infrared (5-20 μm) and visible-light imaging between November 2010 and November 2011. The SEB revival consisted of convective eruptions triggered over ∼100 days, potentially powered by the latent heat released by the condensation of water. The plumes rise from the water cloud base and ultimately diverge and cool in the stably-stratified upper troposphere. Thermal-IR images from the Very Large Telescope (VLT) were acquired 2 days after the SEB disturbance was first detected as a small white spot by amateur observers on November 9th 2010. Subsequent images over several months revealed the cold, putatively anticyclonic and cloudy plume tops (area 2.5 × 106 km2) surrounded by warm, cloud-free conditions at their peripheries due to subsidence. The latent heating was not directly detectable in the 5-20 μm range. The majority of the plumes erupted from a single source near 140 -160∘ W, coincident with the remnant cyclonic circulation of a brown barge that had formed during the fade. The warm remnant of the cyclone could still be observed in IRTF imaging 5 days before the November 9th eruption. Additional plumes erupted from the leading edge of the central disturbance immediately east of the source, which propagated slowly eastwards to encounter the Great Red Spot. The tropospheric plumes were sufficiently vigorous to excite stratospheric thermal waves over the SEB with a 20 -30∘ longitudinal wavelength and 5-6 K temperature contrasts at 5 mbar, showing a direct connection between moist convection and stratospheric wave activity. The subsidence and compressional heating of dry, unsaturated air warmed the troposphere (particularly to the northwest of the central branch of the revival) and removed the aerosols that had been responsible for the fade. Dark, cloud-free lanes west of the plumes were the first to show the colour change, and elongated due to the zonal windshear to form the characteristic 'S-shape' of the revival complex. The aerosol-free air was redistributed and mixed throughout the SEB by the zonal flow, following a westward-moving southern branch and an eastward-moving northern branch that revived the brown colouration over ∼200 days. The transition from the cool conditions of the SEBZ during the fade to the revived SEB caused a 2-4 K rise in 500-mbar temperatures (leaving a particularly warm southern SEB) and a reduction of aerosol opacity by factors of 2-3. Newly-cleared gaps in the upper tropospheric aerosol layer appeared different in filters sensing the ∼700-mbar cloud deck and the 2-3 bar cloud deck, suggesting complex vertical structure in the downdrafts. The last stage of the revival was the re-establishment of normal convective activity northwest of the GRS in September 2011, ∼840 days after the last occurrence in June 2009. Moist convection may therefore play an important role in controlling the timescale and atmospheric variability during the SEB life cycle.

KSC-99pp0833

NASA Image and Video Library

1999-07-16

Commander of the Air Force Space Command, General Richard B. Myers (left) joins Ed Gormel (center) and Commander of the 45th Space Wing Brig. Gen. F. Randall Starbuck (right) after the presentation of the Hammer Award. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. Morley Winograd, director of the National Partnership for Reinventing Government, presented the award to the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Gormel is a co-chair of the SEB. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the J-BOSC SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base

The Hammer Award is presented to KSC and 45th Space Wing.

NASA Technical Reports Server (NTRS)

1999-01-01

Commander of the Air Force Space Command, General Richard B. Myers (left) joins Ed Gormel (center) and Commander of the 45th Space Wing Brig. Gen. F. Randall Starbuck (right) after the presentation of the Hammer Award. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. Morley Winograd, director of the National Partnership for Reinventing Government, presented the award to the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Gormel is a co-chair of the SEB. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the J-BOSC SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base.

Structure of the superantigen staphylococcal enterotoxin B in complex with TCR and peptide-MHC demonstrates absence of TCR-peptide contacts.

PubMed

Rödström, Karin E J; Elbing, Karin; Lindkvist-Petersson, Karin

2014-08-15

Superantigens are immune-stimulatory toxins produced by Staphylococcus aureus, which are able to interact with host immune receptors to induce a massive release of cytokines, causing toxic shock syndrome and possibly death. In this article, we present the x-ray structure of staphylococcal enterotoxin B (SEB) in complex with its receptors, the TCR and MHC class II, forming a ternary complex. The structure, in combination with functional analyses, clearly shows how SEB adopts a wedge-like position when binding to the β-chain of TCR, allowing for an interaction between the α-chain of TCR and MHC. Furthermore, the binding mode also circumvents contact between TCR and the peptide presented by MHC, which enables SEB to initiate a peptide-independent activation of T cells. Copyright © 2014 by The American Association of Immunologists, Inc.

Multicomponent Solvated Triblock Copolymer Network Systems: Fundamental Insights and Emerging Applications

NASA Astrophysics Data System (ADS)

Krishnan, Arjun Sitaraman

Block copolymers have received significant research attention in recent times due to their ability to spontaneously self-assemble into a variety of nanostructures. Thermoplastic elastomers composed of styrenic triblock copolymers are of great importance in applications such as adhesives and vibration dampening due to their shape memory, resilience and facile processing. The swelling of these polymers by adding midblock selective solvents or oligomers provides an easy route by which to modify the morphology and mechanical behavior of these systems. We first consider a ternary blend of a poly[styrene- b-(ethylene-co-butylene)-b-styrene] triblock copolymer (SEBS) and mixtures of two midblock selective co-solvents, with significantly different physical states. We use dynamic rheology to study the viscoelastic response of a wide variety of systems under oscillatory shear. Frequency spectra acquired at ambient temperature display viscoelastic behavior that shifts in the frequency domain depending on the co-solvent composition. For each copolymer concentration, all the frequency data can be shifted by time-composition superpositioning (tCS) to yield a single master-curve. tCS fails at low frequencies due to presence of endblock pullout, which is a fundamentally different relaxation process from segmental relaxation of the midblock. As an emerging technology, we examine SEBS-oil gels as dielectric elastomers. Dielectric elastomers constitute one class of electroactive polymers (EAPs), polymeric materials that respond to an electric stimulus by changing their macroscopic dimensions, thereby converting electrical energy into mechanical work. We use standard configuration of EAP devices involving stretching, or "prestraining," the elastomer film biaxially. The effect of experimental parameters such as film thickness and amount of prestrain on the (electro)mechanical properties of the material become apparent by recasting as-obtained electroactuation data into compressive electromechanical stress-strain curves. The ultimate dielectric properties of the specimen are strongly correlated with specimen composition and experimental conditions. We shed light on the effect of biaxial prestrain on copolymer morphology. We use small-angle X-ray scattering (SAXS) to probe the nanostructure of SEBS-oil gels by systematically changing the concentration of polymer and the biaxial prestrain. Azimuthally integrated intensity profiles are used to ascertain the extent of deformation of polystyrene microdomains. The structure factor data correlates with prestrain, and is fitted using the Percus-Yevick approximation for interacting spheres. While a hard sphere interaction model is sufficient for unstrained gels, the additional attractive potentials observed in stretched samples are indicative of soft coronal interactions due to interpenetration brought about by strain.

Fatigue-propagation du melange polymere polystyrene/polyethylene

NASA Astrophysics Data System (ADS)

Bureau, Martin N.

The interrelations between the morphology of PS/HDPE and PS/SEBS/HDPE immiscible polymer blends and their mechanical behavior, namely in monotonic loading and in cyclic loading, were studied. As predicted by theory, high shear rates encountered during extrusion blending led to efficient minor phase emulsification in PS/HDPE blends for which the viscosity ratio approaches unity. Consequently, the emulsifying effect of an SEBS triblock copolymer employed as a compatibilizer was found to be negligible. In subsequent molding process, disintegration, shape relaxation and coarsening of the minor phase domains were responsible for the morphological evolution of the blends. In the compression molding process, morphological observations showed that the rate of minor phase coarsening followed the predictions of the Ostwald ripening theory, in agreement with the rheological analysis. In the injection molding process, minor phase coarsening was attributed to shear coalescence. The fatigue crack propagation behavior of injection-molded specimens of pure PS as well as of 95/5, 85/15 and 70/30 PS/HDPE blends and of 95/(0.5/4.5), 85/(1.5/13.5) and 70/(3/27) PS/(SEBS/HDPE) blends was then studied. The fatigue fracture surface features of specimens of pure PS as well as of PS/HDPE and PS/SEBS/HDPE blends were analyzed in detail in order to interpret their fatigue crack propagation behavior. In pure PS specimens, discontinuous growth bands, associated with the fracture of crazes in the plastic zone, formed at low fatigue crack growth rates, large dimple-like features at intermediate fatigue crack growth rates and fatigue striations at high fatigue crack growth rates. The fracture toughness of injection-molded specimens of pure PS as well as of 95/5, 85/15 and 70/30 PS/HDPE blends and of 95/(0.5/4.5) PS/(SEBS/HDPE), 85/(1.5/13.5) and 70/(3/27) PS/(SEBS/HDPE) was finally studied. The results showed that the addition of HDPE to PS led to a reduction of the fracture toughness KQ following ASTM E-399 when compared to that of pure PS. This effect was attributed to the very fine minor phase morphology of the blends obtained after extrusion blending and injection molding. (Abstract shortened by UMI.)

3D-Printed Millimeter Wave Structures

DTIC Science & Technology

2016-03-14

demonstrates the resolution of the printer with a 10 micron nozzle. Figure 2: Measured loss tangent of SEBS and SBS samples. 3D - Printed Millimeter... 3D printing of styrene-butadiene-styrene (SBS) and styrene ethylene/butylene-styrene (SEBS) is used to demonstrate the feasibility of 3D - printed ...Additionally, a dielectric lens is printed which improves the antenna gain of an open-ended WR-28 waveguide from 7 to 8.5 dBi. Keywords: 3D printing

Oil-based gel phantom for ultrasound and optical imaging

NASA Astrophysics Data System (ADS)

Cabrelli, Luciana C.; Pelissari, Pedro I. B. G. B.; Aggarwal, Lucimara P.; Deana, Alessandro M.; Carneiro, Antonio A. O.; Pavan, Theo. Z.

2015-06-01

Water-based materials are commonly used in phantoms for ultrasound and optical imaging techniques. However, these materials have disadvantages such as easy degradation and low temporal stability. In this study, we propose an oil-based new tissue mimicking material for ultrasound and optical imaging, with the advantage of presenting low temporal degradation. Styrene-Ethylene/Butylene-Styrene (SEBS) copolymer in mineral oil samples were made varying the SEBS concentration between 5-15%, and low-density polyethylene (LDPE) between 0-9%. Acoustic properties such as speed of sound and attenuation coefficient were obtained by the substitution technique with frequencies ranging from 2.25-10 MHz, and were consistent to that of soft tissue. These properties were controlled varying SEBS and LDPE concentration; speed of sound from 1445-1480 m/s, and attenuation from 0.86-11.31 dB/cm were observed. SEBS gels with 0% of LDPE were optically transparent, presenting low optical absorption and scattering coefficients in the visible region of the spectrum. In order to fully characterize the optical properties of the samples, the reflectances of the surfaces were measured, along with the absorption. Scattering and absorption coefficients ranging from 400 nm to 1200 nm were calculated for each compound. The results showed that the presence of LDPE increased absorption and scattering of the phantoms. The results suggest the copolymer gels are promising for ultrasound and optical imaging, what make them also potentially useful for photoacoustic imaging.

Improvement of conventional transcutaneous bilirubinometry results in term newborn infants.

PubMed

Felc, Zlata

2005-05-01

This prospective study was performed to determine a way to improve conventional transcutaneous bilirubinometry results in healthy term newborn infants. In 118 infants during phototherapy (group A), and in 118 infants without phototherapy (group B), bilirubin determinations were done in duplicate using the Minolta AirShields Jaundice Meter type 101 (transcutaneous bilirubin index [TcB]), and the diazometric method on the Hitachi 717 Automated Analyzer (total reacting serum bilirubin [SeB]). In 112 infants (group C), bilirubin determinations were done in triplicate, using simple direct-reading photometry on the Moltronic Bilirubinometer (direct serum bilirubin [BiB]). A close correlation between TcB and SeB values was observed in group A ( r = 0.69; p < 0.001) and in group B ( r = 0.59; p < 0.001). The 95% confidence intervals of TcB readings corresponding to SeB were +/- 80.7 micromol/L in group A and +/- 76.9 micromol/L in group B, respectively. In group C, using a correctly calibrated BiB with adult sera containing bilirubin concentration in the range 271 to 344 micromol/L, the 95% confidence intervals of parallel TcB and BiB readings corresponding to SeB were +/- 28 micromol/L. Parallel determinations of the TcB and the BiB in healthy term newborn infants give results almost identical to those of bilirubin determination by the laboratory method.

Invariant Natural Killer T Cells Are Pathogenic in the HLA-DR4-Transgenic Humanized Mouse Model of Toxic Shock Syndrome and Can Be Targeted to Reduce Morbidity.

PubMed

Szabo, Peter A; Rudak, Patrick T; Choi, Joshua; Xu, Stacey X; Schaub, Robert; Singh, Bhagirath; McCormick, John K; Haeryfar, S M Mansour

2017-03-01

During toxic shock syndrome (TSS), bacterial superantigens trigger a polyclonal T -cell response leading to a potentially catastrophic "cytokine storm". Whether innate-like invariant natural killer T (iNKT) cells, with remarkable immunomodulatory properties, participate in TSS is unclear. Using genetic and cell depletion approaches, we generated iNKT cell-deficient, superantigen-sensitive HLA-DR4-transgenic (DR4tg) mice, which were compared with their iNKT-sufficient counterparts for responsiveness to staphylococcal enterotoxin B (SEB). Both approaches indicate that iNKT cells are pathogenic in TSS. Importantly, treating DR4tg mice with a TH2-polarizing glycolipid agonist of iNKT cells reduced SEB-inflicted morbidity/mortality. Therefore, iNKT cells may constitute an attractive therapeutic target in superantigen-mediated illnesses. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

An investigation of satellite sounding products for the remote sensing of the surface energy balance and soil moisture

NASA Technical Reports Server (NTRS)

Diak, George R.

1989-01-01

Improved techniques for the remote sensing of the land surface energy balance (SEB) and soil moisture would greatly improve prediction of climate and weather as well as be of benefit to agriculture, hydrology and many associated fields. Most of the satellite remote sensing methods which were researched to date rely upon satellite-measured infrared surface temperatures or their time changes as a remote sensing signal. Optimistically, only four or five levels of information (wet to dry) in surface heating/evaporation are discernable by surface temperature methods and a good understanding of atmospheric conditions is necessary to bring them to this accuracy level. Skin temperature methods were researched as well as begun work on several new methods for the remote sensing of the SEB, some elements of which are applicable to current and retrospective data sources and some which will rely on instrumentation from the Earth Observing System (EOS) program in the 1990s.

Displacement Damage Induced Catastrophic Second Breakdown in Silicon Carbide Schottky Power Diodes

NASA Technical Reports Server (NTRS)

Scheick, Leif; Selva, Luis; Selva, Luis

2004-01-01

A novel catastrophic breakdown mode in reversed biased Silicon carbide diodes has been seen for low LET particles. These particles are too low in LET to induce SEB, however SEB was seen from particles of higher LET. The low LET mechanism correlates with second breakdown in diodes due to increase leakage and assisted charge injection from incident particles. Percolation theory was used to predict some basic responses of the devices, but the inherent reliability issue with silicon carbide have proven challenging.

Review of Chemical, Biological, Radiological, and Nuclear (CBRN) Terminology in Technical Guide 316 (TG 316) and Allied Medical Publication 8(C) (AMedP-8(C))

DTIC Science & Technology

2013-05-01

tularensis causing pneumonic tularemia (Aberdeen Proving Ground, MD: USAPHC, January 2012); USAPHC, Technical Guide 316 Supplement F1; USAPHC, Technical...Phase I preliminary BMEGs are completed for anthrax, plague, tularemia , ricin, and Staphylococcal Enterotoxin B (SEB). The Phase II process has been...Exposure to Specified Biological Agents: Brucellosis, Glanders, Q Fever, SEB and Tularemia , IDA Document D-4132 (Alexandria, VA: Institute for Defense

Conductive paint-filled cement paste sensor for accelerated percolation

NASA Astrophysics Data System (ADS)

Laflamme, Simon; Pinto, Irvin; Saleem, Hussam S.; Elkashef, Mohamed; Wang, Kejin; Cochran, Eric

2015-04-01

Cementitious-based strain sensors can be used as robust monitoring systems for civil engineering applications, such as road pavements and historic structures. To enable large-scale deployments, the fillers used in creating a conductive material must be inexpensive and easy to mix homogeneously. Carbon black (CB) particles constitute a promising filler due to their low cost and ease of dispersion. However, a relatively high quantity of these particles needs to be mixed with cement in order to reach the percolation threshold. Such level may influence the physical properties of the cementitious material itself, such as compressive and tensile strengths. In this paper, we investigate the possibility of utilizing a polymer to create conductive chains of CB more quickly than in a cementitious-only medium. This way, while the resulting material would have a higher conductivity, the percolation threshold would be reached with fewer CB particles. Building on the principle that the percolation threshold provides great sensing sensitivity, it would be possible to fabricate sensors using less conducting particles. We present results from a preliminary investigation comparing the utilization of a conductive paint fabricated from a poly-Styrene-co-Ethylene-co-Butylene-co-Styrene (SEBS) polymer matrix and CB, and CB-only as fillers to create cementitious sensors. Preliminary results show that the percolation threshold can be attained with significantly less CB using the SEBS+CB mix. Also, the study of the strain sensing properties indicates that the SEBS+CB sensor has a strain sensitivity comparable to the one of a CB-only cementitious sensor when comparing specimens fabricated at their respective percolation thresholds.

Nanoleakage in Hybrid Layer and Acid-Base Resistant Zone at the Adhesive/Dentin Interface.

PubMed

Nikaido, Toru; Nurrohman, Hamid; Takagaki, Tomohiro; Sadr, Alireza; Ichinose, Shizuko; Tagami, Junji

2015-10-01

The aim of interfacial nanoleakage evaluation is to gain a better understanding of degradation of the adhesive-dentin interface. The acid-base resistant zone (ABRZ) is recognized at the bonded interface under the hybrid layer (HL) in self-etch adhesive systems after an acid-base challenge. The purpose of this study was to evaluate nanoleakage in HL and ABRZ using three self-etch adhesives; Clearfil SE Bond (SEB), Clearfil SE One (SEO), and G-Bond Plus (GBP). One of the three adhesives was applied on the ground dentin surface and light cured. The specimens were longitudinally divided into two halves. One half remained as the control group. The others were immersed in ammoniacal silver nitrate solution, followed by photo developing solution under fluorescent light. Following this, the specimens were subjected to acid-base challenges with an artificial demineralization solution (pH4.5) and sodium hypochlorite, and prepared in accordance with common procedures for transmission electron microscopy (TEM) examination. The TEM images revealed silver depositions in HL and ABRZ due to nanoleakage in all the adhesives; however, the extent of nanoleakage was material dependent. Funnel-shaped erosion beneath the ABRZ was observed only in the all-in-one adhesive systems; SEO and GBP, but not in the two-step self-etch adhesive system; SEB.

Improved biocompatibility of poly (styrene-b-(ethylene-co-butylene)-b-styrene) elastomer by a surface graft polymerization of hyaluronic acid.

PubMed

Li, Xiaomeng; Luan, Shifang; Shi, Hengchong; Yang, Huawei; Song, Lingjie; Jin, Jing; Yin, Jinghua; Stagnaro, Paola

2013-02-01

Hyaluronic acid (HA) is an important component of extracellular matrix (ECM) in many tissues, providing a hemocompatible and supportive environment for cell growth. In this study, glycidyl methacrylate-hyaluronic acid (GMHA) was first synthesized and verified by proton nuclear magnetic resonance ((1)H NMR) spectroscopy. GMHA was then grafted to the surface of biomedical elastomer poly (styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) via an UV-initiated polymerization, monitored by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). The further improvement of biocompatibility of the GMHA-modified SEBS films was assessed by platelet adhesion experiments and in vitro response of murine osteoblastic cell line MC-3T3-E1 with the virgin SEBS surface as the reference. It showed that the surface modification with HA strongly resisted platelet adhesion whereas improved cell-substrate interactions. Copyright © 2012 Elsevier B.V. All rights reserved.

Social support seeking and self-efficacy-building strategies in enhancing the emotional well-being of informal HIV/AIDS caregivers in Ibadan, Oyo state, Nigeria.

PubMed

Okeke, Bernedette Okwuchukwu

2016-01-01

This study examined the relative efficacy of social support seeking (SSS) and self-efficacy building (SEB) in the management of emotional well-being of caregivers of people suffering from HIV/AIDS. It was based at the United States President's Emergency Plan for AIDS Relief (PEPFAR) center in the University College Hospital, Ibadan, Oyo state, being the first and the largest teaching hospital in Nigeria. A 3 × 2 factorial design consisting of treatment and a control group was used. The columns have two levels of gender being male and female caregivers. One-hundred and sixty-five (165) caregivers who were taking care of people that are suffering from HIV/AIDS were purposively selected and randomly assigned to the treatment groups and control. The treatment was carried out for a period of eight weeks. Two null hypotheses were tested, both at .05 levels of significance. Data were collected with the use of standardized intruments rating scale; social support scale, general self-efficacy scale and emotional well-being scale. ANCOVA was used to establish significant treatment effects with the pretest as covariate. Even though SSS and SEB were both found to be effective in enhancing the emotional well-being of informal caregivers in this study when compared to the controls, SSS was significantly more effective than SEB in achieving this goal. Since the HIV/AIDS patients cannot be adequately cared for in the hospital settings due to severe shortages of material, personnel and time, serious efforts should be made by the three levels of the health care system viz: the primary, secondary and tertiary health care systems, to encourage the employment of the psychological management of caregivers of people suffering from HIV/AIDS. Also, the psychologists, clinical psychologists and the significant others should be encouraged to employ this psychological management in the care of HIV/AIDS informal caregivers.

Social support seeking and self-efficacy-building strategies in enhancing the emotional well-being of informal HIV/AIDS caregivers in Ibadan, Oyo state, Nigeria

PubMed Central

Okeke, Bernedette Okwuchukwu

2016-01-01

Abstract This study examined the relative efficacy of social support seeking (SSS) and self-efficacy building (SEB) in the management of emotional well-being of caregivers of people suffering from HIV/AIDS. It was based at the United States President's Emergency Plan for AIDS Relief (PEPFAR) center in the University College Hospital, Ibadan, Oyo state, being the first and the largest teaching hospital in Nigeria. A 3 × 2 factorial design consisting of treatment and a control group was used. The columns have two levels of gender being male and female caregivers. One-hundred and sixty-five (165) caregivers who were taking care of people that are suffering from HIV/AIDS were purposively selected and randomly assigned to the treatment groups and control. The treatment was carried out for a period of eight weeks. Two null hypotheses were tested, both at .05 levels of significance. Data were collected with the use of standardized intruments rating scale; social support scale, general self-efficacy scale and emotional well-being scale. ANCOVA was used to establish significant treatment effects with the pretest as covariate. Even though SSS and SEB were both found to be effective in enhancing the emotional well-being of informal caregivers in this study when compared to the controls, SSS was significantly more effective than SEB in achieving this goal. Since the HIV/AIDS patients cannot be adequately cared for in the hospital settings due to severe shortages of material, personnel and time, serious efforts should be made by the three levels of the health care system viz: the primary, secondary and tertiary health care systems, to encourage the employment of the psychological management of caregivers of people suffering from HIV/AIDS. Also, the psychologists, clinical psychologists and the significant others should be encouraged to employ this psychological management in the care of HIV/AIDS informal caregivers. PMID:26831832

NATO Planning Guide for the Estimation of Chemical, Biological, Radiological, and Nuclear (CBRN) Casualties (AMedP-8(C)) - Parameters for Estimation of Casualties from Exposure to Specified Biological Agents. Addenda to Allied Medical Publication 8

DTIC Science & Technology

2011-01-01

glanders, Q fever, and tularemia , as well as the biotoxin staphylococcal enterotoxin B. Incorporating these five agents into the published NATO guide will...Specified Biological Agents: Brucellosis, Glanders, Q Fever, SEB, and Tularemia . This document describes the research methods used by the study authors...enterotoxin B (SEB), and tularemia . Several editorial changes, such as renumbering figures and tables, updating the corresponding references in the text, and

The National Ocean Sciences Bowl: An Effective Model for Engaging High School Students in Ocean Science

NASA Astrophysics Data System (ADS)

Holloway, A. E.

2016-02-01

The National Ocean Sciences Bowl (NOSB) is an informal high school education program that engages students in ocean and environmental science and exposes them to the breadth of ocean-related careers. The NOSB strives to train the next generation of interdisciplinary capable scientists and build a STEM-literate society that harnesses the power of ocean and climate science to address environmental, economic, and societal issues. Through the NOSB, students not only learn scientific principles, but also apply them to compelling real-world problems. The NOSB provides a richer STEM education and exposes students to ocean science topics they may not otherwise study through classroom curriculum. A longitudinal study that began in 2007 has shown that NOSB participants have an enhanced interest in ocean-related hobbies and environmental stewardship and an increasing number of these students have remained in the STEM pipeline and workforce.While the NOSB is primarily an academic competition, it has evolved since its creation in 1998 to include a variety of practical and professional development components. One of the program enhancements, the Scientific Expert Briefing (SEB), gives students the opportunity to apply what they have studied and think critically about current and ongoing ocean science challenges. The SEB helps students connect their knowledge of ocean science with current and proposed policy initiatives. Students gain significant research, writing, and presentation skills, while enhancing their ability for collaboration and consensus building, all vital workforce skills. Ultimately, the SEB teaches students how to communicate complex scientific research into digestible information for decision-makers and the general public.This poster will examine the impact of the NOSB and its role in strengthening the workforce pipeline through a combination of independent learning, competition, and opportunities for communication skills development.

Experimental Seismic Event-screening Criteria at the Prototype International Data Center

NASA Astrophysics Data System (ADS)

Fisk, M. D.; Jepsen, D.; Murphy, J. R.

- Experimental seismic event-screening capabilities are described, based on the difference of body-and surface-wave magnitudes (denoted as Ms:mb) and event depth. These capabilities have been implemented and tested at the prototype International Data Center (PIDC), based on recommendations by the IDC Technical Experts on Event Screening in June 1998. Screening scores are presented that indicate numerically the degree to which an event meets, or does not meet, the Ms:mb and depth screening criteria. Seismic events are also categorized as onshore, offshore, or mixed, based on their 90% location error ellipses and an onshore/offshore grid with five-minute resolution, although this analysis is not used at this time to screen out events.Results are presented of applications to almost 42,000 events with mb>=3.5 in the PIDC Standard Event Bulletin (SEB) and to 121 underground nuclear explosions (UNE's) at the U.S. Nevada Test Site (NTS), the Semipalatinsk and Novaya Zemlya test sites in the Former Soviet Union, the Lop Nor test site in China, and the Indian, Pakistan, and French Polynesian test sites. The screening criteria appear to be quite conservative. None of the known UNE's are screened out, while about 41 percent of the presumed earthquakes in the SEB with mb>=3.5 are screened out. UNE's at the Lop Nor, Indian, and Pakistan test sites on 8 June 1996, 11 May 1998, and 28 May 1998, respectively, have among the lowest Ms:mb scores of all events in the SEB.To assess the validity of the depth screening results, comparisons are presented of SEB depth solutions to those in other bulletins that are presumed to be reliable and independent. Using over 1600 events, the comparisons indicate that the SEB depth confidence intervals are consistent with or shallower than over 99.8 percent of the corresponding depth estimates in the other bulletins. Concluding remarks are provided regarding the performance of the experimental event-screening criteria, and plans for future improvements, based on recent recommendations by the IDC Technical Experts on Event Screening in May 1999.

Activation of mouse liver natural killer cells and NK1.1(+) T cells by bacterial superantigen-primed Kupffer cells.

PubMed

Dobashi, H; Seki, S; Habu, Y; Ohkawa, T; Takeshita, S; Hiraide, H; Sekine, I

1999-08-01

Although bacterial superantigens have been well characterized as potent stimulators of T cells, their role in natural killer (NK)-type cells remains largely unknown. In the present study, we examined the effect of bacterial superantigens on mouse liver NK cells and NK1.1 Ag(+) (NK1(+)) T cells. C57BL/6 mice were intravenously injected with staphylococcal enterotoxin B (SEB) or streptococcal pyrogenic exotoxin A (SPE-A), and mononuclear cells (MNC) of various organs were obtained from mice 4 hours after being injected with superantigen. MNC were cultured for 48 hours, and interferon gamma (IFN-gamma) levels of supernatants were measured. The antitumor cytotoxicities of the liver and spleen MNC were also evaluated 24 hours after the mice were injected with superantigen. Liver MNC produced more IFN-gamma than did splenocytes, and peripheral blood and lung MNC did not produce any detectable IFN-gamma. In addition, liver MNC acquired a potent antitumor cytotoxicity by the SEB injection, and both NK cells and NK1(+)T cells but not cluster of differentiation (CD)8(+) T cells were responsible for the cytotoxicity as demonstrated by either in vivo or in vitro cell depletion experiments, and the NK-type cells were partly responsible for the increased serum IFN-gamma. Activation of liver NK-type cells was also supported by the fact that liver NK cells proportionally increased and NK1(+) T cells augmented their CD11a expressions after SEB injection. The pretreatment of mice with anti-IFN-gamma Ab and/or with anti-interleukin-12 (IL-12) Ab diminished the SEB-induced cytotoxicity of liver MNC. Furthermore, the in vivo depletion of Kupffer cells decreased the SEB-induced cytotoxicity of liver MNC. Consistent with these results, liver MNC stimulated with superantigens in the presence of Kupffer cells in vitro produced a greater amount of IFN-gamma than did the liver MNC without Kupffer cells or splenocytes. Our results suggest that bacterial superantigen-primed Kupffer cells produce IL-12 and other monokines, while also nonspecifically activating both NK cells and NK1(+) T cells to produce IFN-gamma.

Simulation study on single event burnout in linear doping buffer layer engineered power VDMOSFET

NASA Astrophysics Data System (ADS)

Yunpeng, Jia; Hongyuan, Su; Rui, Jin; Dongqing, Hu; Yu, Wu

2016-02-01

The addition of a buffer layer can improve the device's secondary breakdown voltage, thus, improving the single event burnout (SEB) threshold voltage. In this paper, an N type linear doping buffer layer is proposed. According to quasi-stationary avalanche simulation and heavy ion beam simulation, the results show that an optimized linear doping buffer layer is critical. As SEB is induced by heavy ions impacting, the electric field of an optimized linear doping buffer device is much lower than that with an optimized constant doping buffer layer at a given buffer layer thickness and the same biasing voltages. Secondary breakdown voltage and the parasitic bipolar turn-on current are much higher than those with the optimized constant doping buffer layer. So the linear buffer layer is more advantageous to improving the device's SEB performance. Project supported by the National Natural Science Foundation of China (No. 61176071), the Doctoral Fund of Ministry of Education of China (No. 20111103120016), and the Science and Technology Program of State Grid Corporation of China (No. SGRI-WD-71-13-006).

Re-Verification of the IRHN57133SE and IRHN57250SE for Single Event Gate Rupture and Single Event Burnout

NASA Technical Reports Server (NTRS)

Scheick, Leif

2010-01-01

The vertical metal oxide semiconductor field-effect transistor (MOSFET) is a widely used power transistor onboard a spacecraft. The MOSFET is typically employed in power supplies and high current switching applications. Due to the inherent high electric fields in the device, power MOSFETs are sensitive to heavy ion irradiation and can fail catastrophically as a result of single event gate rupture (SEGR) or single event burnout (SEB). Manufacturers have designed radiation-hardened power MOSFETs for space applications. These radiation hardened devices are not immune to SEGR or SEB but, rather, can exhibit them at a much more damaging ion than their non-radiation hardened counterparts. See [1] through [5] for more information.This effort was to investigate the SEGR and SEB responses of two power MOSFETs from IR(the IRHN57133SE and the IRHN57250SE) that have recently been produced on a new fabrication line. These tests will serve as a limited verification of these parts, but it is acknowledged that further testing on the respective parts may be needed for some mission profiles.

Influence of electron beam irradiation on mechanical and thermal properties of polypropylene/polyamide blend

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakamura, Shigeya, E-mail: shi-nakamura@hitachi-chem.co.jp; Tokumitsu, Katsuhisa

The effects of electron beam irradiation on the mechanical and thermal properties of polypropylene (PP) and polyamide6 (PA6) blends-with talc 20 wt% as filler, SEBS-g-MAH as compatibilizer, and triallyl isocyanurate as crosslinking agent-were investigated. Although the tensile and flexural moduli and strengths of the PP/PA6 blends with talc, SEBS-g-MAH, and TAIC could be increased by the application of electron beam irradiation, the impact strength was decreased. Ddifferential scanning calorimetryer measurements showed that the melting temperatures of all PP/PA6 blends were decreased with increases in the electron beam irradiationdose. From dynamic mechanical analyzer results, a storage modulus curve in the plateaumore » region was observed only in the PP/PA6 blends with talc, SEBS-g-MAH, and TAIC; the storage modulus increased with increasing electron beam irradiation dose, indicating that the three-dimensional network developed gradually in the more amorphous PA6. As a result, the most significant improvement observed in heat distortion tests under high load (1.8 MPa) occurred at 200 kGy.« less

The Hammer Award is presented to KSC and 45th Space Wing.

NASA Technical Reports Server (NTRS)

1999-01-01

At a special presentation of the Hammer Award in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex, former Apollo astronauts Neil Armstrong (left) and Edwin 'Buzz' Aldrin (second from right) applauded the recipients, Kennedy Space Center and the 45th Space Wing. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Ed Gormel and Chris Fairey, co-chairs of the SEB, accepted the awards for the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base. Armstrong and Aldrin were at KSC to attend a banquet and other activities for the 30th anniversary of the Apollo 11 mission, which landed the first man on the moon.

KSC-99pp0839

NASA Image and Video Library

1999-07-16

At a special presentation of the Hammer Award in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex, former Apollo astronauts Neil Armstrong (left) and Edwin "Buzz" Aldrin (second from right) applauded the recipients, Kennedy Space Center and the 45th Space Wing. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Ed Gormel and Chris Fairey, co-chairs of the SEB, accepted the awards for the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base. Armstrong and Aldrin were at KSC to attend a banquet and other activities for the 30th anniversary of the Apollo 11 mission, which landed the first man on the moon

ELISA-LOC: lab-on-a-chip for enzyme-linked immunodetection.

PubMed

Sun, Steven; Yang, Minghui; Kostov, Yordan; Rasooly, Avraham

2010-08-21

A miniature 96 sample ELISA-lab-on-a-chip (ELISA-LOC) was designed, fabricated, and tested for immunological detection of Staphylococcal Enterotoxin B (SEB). The chip integrates a simple microfluidics system into a miniature ninety-six sample plate, allowing the user to carry out an immunological assay without a laboratory. Assay reagents are delivered into the assay plate without the need for separate devices commonly used in immunoassays. The ELISA-LOC was constructed using Laminated Object Manufacturing (LOM) technology to assemble six layers with an acrylic (poly(methyl methacrylate) (PMMA)) core and five polycarbonate layers micromachined by a CO(2) laser. The ELISA-LOC has three main functional elements: reagent loading fluidics, assay and detection wells, and reagent removal fluidics, a simple "surface tension" valve used to control the flow. To enhance assay sensitivity and to perform the assay without a lab, ELISA-LOC detection combines several biosensing elements: (1) carbon nanotube (CNT) technology to enhance primary antibody immobilization, (2) sensitive ECL (electrochemiluminescence) detection, and (3) a charge-coupled device (CCD) detector for measuring the light signal generated by ECL. Using a sandwich ELISA assay, the system detected SEB at concentrations as low as 0.1 ng ml(-1), which is similar to the reported sensitivity of conventional ELISA. The fluidics system can be operated by a syringe and does not require power for operation. This simple point-of-care (POC) system is useful for carrying out various immunological assays and other complex medical assays without a laboratory.

Delayed BCG vaccination results in minimal alterations in T cell immunogenicity of acellular pertussis and tetanus immunizations in HIV-exposed infants.

PubMed

Blakney, Anna K; Tchakoute, Christophe Toukam; Hesseling, Anneke C; Kidzeru, Elvis B; Jones, Christine E; Passmore, Jo-Ann S; Sodora, Donald L; Gray, Clive M; Jaspan, Heather B

2015-09-11

Bacille Calmette-Guerin (BCG) is effective in preventing disseminated tuberculosis (TB) in children but may also have non-specific benefits, and is thought to improve immunity to unrelated antigens through trained innate immunity. In HIV-infected infants, there is a risk of BCG-associated adverse events. We aimed to explore whether delaying BCG vaccination by 8 weeks, in utero or perinatal HIV infection is excluded, affected T-cell responses to B. pertussis (BP) and tetanus toxoid (TT), in HIV-exposed, uninfected infants. Infants were randomized to receive BCG vaccination at birth or 8 weeks of age. At 8 and 14 weeks, T cell proliferation and intracellular cytokine (IL-2, IL-13, IL-17, and IFN-γ) expression was analyzed in response to BP, TT and Staphylococcal enterotoxin B (SEB) antigens. Delaying BCG vaccination did not alter T-cell proliferation to BP or TT antigens. Infants immunized with BCG at birth had higher CD4+ T cell proliferation to SEB at 14 weeks of age (p=0.018). Birth-vaccinated infants had increased CD8+ IL-2 expression in response to BP, but not TT or SEB, at 8 weeks. Infants vaccinated with BCG at 8 weeks had significantly lower IL-13 expression by BP-specific CD4+ and CD8+ T cells at 14 weeks (p=0.032 and p=0.0035, respectively). There were no observed differences in multifunctional cytokine response to TT, BP or SEB between infants vaccinated with BCG at birth versus 8 weeks of age. Delaying BCG vaccination until 8 weeks of age results in robust T-cellular responses to BP and TT in HIV-exposed infants. NCT02062580. Copyright © 2015 Elsevier Ltd. All rights reserved.

Rinse-resistant superhydrophobic block copolymer fabrics by electrospinning, electrospraying and thermally-induced self-assembly

NASA Astrophysics Data System (ADS)

Wu, Jie; Li, Xin; Wu, Yang; Liao, Guoxing; Johnston, Priscilla; Topham, Paul D.; Wang, Linge

2017-11-01

An inherent problem that restricts the practical application of superhydrophobic materials is that the superhydrophobic property is not sustainable; it can be diminished, or even lost, when the surface is physically damaged. In this work, we present an efficient approach for the fabrication of superhydrophobic fibrous fabrics with great rinse-resistance where a block copolymer has been electrospun into a nanofibrous mesh while micro-sized beads have been subsequently electrosprayed to give a morphologically composite material. The intricate nano- and microstructure of the composite was then fixed by thermally annealing the block copolymer to induce self-assembly and interdigitation of the microphase separated domains. To demonstrate this approach, a polystyrene-b-poly(ethylene-co-butylene)-b-polystyrene (SEBS) nanofibrous scaffold was produced by electrospinning before SEBS beads were electrosprayed into this mesh to form a hierarchical micro/nanostructure of beads and fibers. The effects of type and density of SEBS beads on the surface morphology and wetting properties of composite membranes were studied extensively. Compared with a neat SEBS fibrous mesh, the composite membrane had enhanced hydrophobic properties. The static water contact angle increased from 139° (±3°) to 156° (±1°), while the sliding angle decreased to 8° (±1°) from nearly 90°. In order to increase the rinse-resistance of the composite membrane, a thermal annealing step was applied to physically bind the fibers and beads. Importantly, after 200 h of water flushing, the hierarchical surface structure and superhydrophobicity of the composite membrane were well retained. This work provides a new route for the creation of superhydrophobic fabrics with potential in self-cleaning applications.

A two-step non-flowcytometry-based naïve B cell isolation method and its application in Staphylococcal enterotoxin B (SEB) presentation.

PubMed

Chokeshai-u-saha, Kaj; Buranapraditkun, Supranee; Jacquet, Alain; Nguyen, Catherine; Ruxrungtham, Kiat

2012-09-01

To study the role of human naïve B cells in antigen presentation and stimulation to naïve CD4+ T cell, a suitable method to reproducibly isolate sufficient naïve B cells is required. To improve the purity of isolated naive B cells obtained from a conventional one-step magnetic bead method, we added a rosetting step to enrich total B cell isolates from human whole blood samples prior to negative cell sorting by magnetic beads. The acquired naïve B cells were analyzed for phenotypes and for their role in Staphylococcal enterotoxin B (SEB) presentation to naïve CD4+ T cells. The mean (SD) naïve B cell (CD19+/CD27-) purity obtained from this two-step method compared with the one-step method was 97% (1.0) versus 90% (1.2), respectively. This two-step method can be used with a sample of whole blood as small as 10 ml. The isolated naive B cells were phenotypically at a resting state and were able to prime naïve CD4+ T cell activation by Staphylococcal enterotoxin B (SEB) presentation. This two-step non-flow cytometry-based approach improved the purity of isolated naïve B cells compared with conventional one-step magnetic bead method. It also worked well with a small blood volume. In addition, this study showed that the isolated naïve B cells can present a super-antigen "SEB" to activate naïve CD4 cells. These methods may thus be useful for further in vitro characterization of human naïve B cells and their roles as antigen presenting cells in various diseases.

Some previous ABL measurements in the Duero and Ebro valleys

NASA Astrophysics Data System (ADS)

Cuxart, Joan

2017-04-01

Evapotranspiration in semi-arid regimes needs improved understanding and representation in numerical models. Most of the Iberian Peninsula (IP) upper soil in summer becomes dry which makes of it a good area for field campaigning and numerical modeling. The two large basins at the northern IP, Duero (essentially non-irrigated cereals) and Ebro (large irrigated areas surrounded by typical mediterranean vegetation), have already seen some ABL research efforts in the last decades. The CIBA site is located over a plateau in the centre of the Duero basin. The plateau has shallow soil over karstic rock, contrarily to the lower areas that are essentially sedimentary. There radiation and fluxes of biogenic gases have been measured during decades by the University of Valladolid. Since 1998 the renovated 100m tower has been used to study the ABL, focusing essentially in the nocturnal stably stratified regime, the mesoscale low-level jets, the effet of surface heterogeneities and fog events. Studies have been supplemented with use of satellital information and high-resolution mesoscale simulations. The center of the Ebro basin was the site of ABL measurements between 2008 and 2011, when a surface energy budget (SEB) station and a WindRASS were operating in the middle of a large vineyard, occasionally irrigated during the summer season, keeping the soil always with enough water content to sustain the needs of the vines. Similar topics as for the Duero basin were inspected, here supplemented by the effect of the surrounding topography and the wet-dry terrain heterogeneities, both contributing to intensify the strength of low-level circulations. The SEB imbalance was quantified and the terms compared to the ones from the ECMWF model, finding very significant differences. The SEB and WindRASS were installed in 2015 in the large Pyrenean valley of La Cerdanya, through which the Segre river (a main tributary of the Ebro) flows. The soil in this area usually retains enough water during all year and does not experience summer soil dryness. This allows that rain events on the mountain may runoff as soon as they take place and a substantial part of the water may reach the dams downriver. A very strong cold pool develops any season of the year in the valley, which usually presents the lowest temperature values of Catalonia.

Simulation Study of Single-Event Burnout in Power Trench ACCUFETs

NASA Astrophysics Data System (ADS)

Yu, Cheng-Hao; Wang, Ying; Fei, Xin-Xing; Cao, Fei

2016-10-01

This paper presents 2-D numerical simulation results of single-event burnout (SEB) in power trench accumulation mode field effect transistor (ACCUFET) for the first time. In this device, a p+ base region is used to deplete the n- base region to achieve a low leakage current density, and the blocking voltage is supported by the n- drift region. We find that the depth of the p+ base region determines both the leakage current density and SEB performance, as a result, there is a tradeoff relationship between the two characteristics. The 60 V hardened power ACCUFET shown in this paper could demonstrate much better SEB performance without sacrificing the current handling capability compared with the standard UMOSFET. The hardened structure mentioned in this paper indicates that an n buffer layer is added between the epitaxial layer and substrate layer based on a basic power device. As a result, the safe operating area (SOA) of the 60 V, 80 V and 100 V hardened ACCUFET discussed in this paper could reach the value of breakdown voltage when the buffer layer is over a certain value, that can realize safety operation throughout entire LET range.

SEGR- and SEB-hardened structure with DSPSOI in power MOSFETs

NASA Astrophysics Data System (ADS)

Tang, Zhaohuan; Fu, Xinghua; Yang, Fashun; Tan, Kaizhou; Ma, Kui; Wu, Xue; Lin, Jiexing

2017-12-01

Single event irradiation-hardened power MOSFET is the most important device for DC/DC converter in space environment application. Single event gate rupture (SEGR) and single event burnout (SEB), which will degrade the running safety and reliability of spacecraft, are the two typical failure modes in power MOSFETs. In this paper, based on recombination mechanism of interface between oxide and silicon, a novel hardened power MOSFETs structure for SEGR and SEB is proposed. The structure comprises double stagger partial silicon-on-insulator (DSPSOI) layers. Results show that the safety operation area (SOA) of a 130 V N-channel power MOSFET in single event irradiation environment is enhanced by up to 50% when the linear-energy-transfer value of heavy ion is a constant of 98 MeV·cm2/mg in the whole incident track, and the other parameters are almost maintained at the same value. Thus this novel structure can be widely used in designing single event irradiation-hardened power MOSFETs. Project supported by the National Natural Science Foundation of China (No. 61464002), the Grand Science and Technology Special Project in Guizhou Province of China (No. [2015]6006), and the Ministry of Education Open Foundation for Semiconductor Power Device Reliability (No. 010201).

The response of surface mass and energy balance of a continental glacier to climate variability, western Qilian Mountains, China

NASA Astrophysics Data System (ADS)

Sun, Weijun; Qin, Xiang; Wang, Yetang; Chen, Jizu; Du, Wentao; Zhang, Tong; Huai, Baojuan

2017-08-01

To understand how a continental glacier responds to climate change, it is imperative to quantify the surface energy fluxes and identify factors controlling glacier mass balance using surface energy balance (SEB) model. Light absorbing impurities (LAIs) at the glacial surface can greatly decrease surface albedo and increase glacial melt. An automatic weather station was set up and generated a unique 6-year meteorological dataset for the ablation zone of Laohugou Glacier No. 12. Based on these data, the surface energy budget was calculated and an experiment on the glacial melt process was carried out. The effect of reduced albedo on glacial melting was analyzed. Owing to continuous accumulation of LAIs, the ablation zone had been darkening since 2010. The mean value of surface albedo in melt period (June through September) dropped from 0.52 to 0.43, and the minimum of daily mean value was as small as 0.1. From the records of 2010-2015, keeping the clean ice albedo fixed in the range of 0.3-0.4, LAIs caused an increase of +7.1 to +16 W m-2 of net shortwave radiation and an removal of 1101-2663 mm water equivalent. Calculation with the SEB model showed equivalent increases in glacial melt were obtained by increasing air temperature by 1.3 and 3.2 K, respectively.

Algorithm of regional surface evaporation using remote sensing: A case study of Haihe basin, China

NASA Astrophysics Data System (ADS)

Xiong, Jun; Wu, Bingfang; Yan, Nana; Hu, Minggang

2007-11-01

Evapotranspiration (ET, or latent heat flux) is the most essential and uncertain factor in water resource management. Remote sensing is a promising tool for estimation of spatial distribution of ET at regional scale with limited ground observations. We developed an algorithm for estimating regional evapotranspiration from MODIS 1b data and ancillary meteorological data. The algorithm is an integration of Penman-Monteith equation and SEBS (Surface Energy Balance System) model. The former is a combination of the energy balance theory and the mass transfer method to compute the evaporation from cropped surfaces from standard climatological records of sunshine, temperature, humidity and wind speed by introducing resistance factors, and the latter determines the spatio-temporal variability of regional evaporative condition. First, we characterized key land surface parameters on satellite over passing days, including fractional vegetation cover (fc), roughness height for momentum (z0m), net radiation (Rn) and soil heat flux (G0); Second, SEBS was applied to partition the sensible heat (H) from latent heat (LE) in combination with Planetary Boundary Layer (PBL) information from seven meteorological stations. A parameterization of surface roughness was applied at mountainous area considering topographic influence; third, we chose available surface resistance (RS) as the temporal-scaling factor. With bulk surface resistance is properly defined, P-M methods is valid for both soil and vegetation canopy. We validated ET from this algorithm with limited actual observations of ET including 2 eddy covariance system dataset and 1 lysimeter sites. Water balance equation is used as a trend-analysis tool to show the consistency between rainfall and ET on four drainage area. As a result, the prototype products showed different accuracy and applicability on different underlying and time scale, which demonstrates the potential of this approach for estimating ET from 1-km to regional spatial scale in North China Plain.

Impaired Cytokine Responses to Epstein-Barr Virus Antigens in Systemic Lupus Erythematosus Patients

PubMed Central

Draborg, Anette Holck; Sandhu, Noreen; Larsen, Nanna; Lisander Larsen, Janni; Jacobsen, Søren; Houen, Gunnar

2016-01-01

We analyzed cytokine responses against latent and lytic Epstein-Barr virus (EBV) antigens in systemic lupus erythematosus (SLE) patients and healthy controls (HCs) to obtain an overview of the distinctive immune regulatory response in SLE patients and to expand the previously determined impaired EBV-directed T-cell response. The concentrations of 14 cytokines (IL2, IL4, IL5, IL6, IL10, IL12, IL17, IL18, IL1β, IFNγ, TNFα, TNFβ, TGFβ, and GM-CSF) were quantified upon stimulation of whole blood with latent state antigen EBNA1, lytic cycle antigen EBV-EA/D, and the superantigen SEB. To avoid results affected by lack of lymphocytes, we focused on SLE patients with normal levels. Decreased induction of IL12, IFNγ, IL17, and IL6 upon EBNA1 stimulation and that of IFNγ, IL6, TNFβ, IL1β, and GM-CSF upon EBV-EA/D stimulation were detected in SLE patients compared to HCs. IFNγ responses, especially, were shown to be reduced. Induction of several cytokines was furthermore impaired in SLE patients upon SEB stimulation, but no difference was observed in basic levels. Results substantiate the previously proposed impaired regulation of the immune response against latent and lytic cycle EBV infection in SLE patients without lymphopenia. Furthermore, results indicate general dysfunction of leukocytes and their cytokine regulations in SLE patients. PMID:27110576

Prevention of allergic rhinitis by ginger and the molecular basis of immunosuppression by 6-gingerol through T cell inactivation.

PubMed

Kawamoto, Yoshiyuki; Ueno, Yuki; Nakahashi, Emiko; Obayashi, Momoko; Sugihara, Kento; Qiao, Shanlou; Iida, Machiko; Kumasaka, Mayuko Y; Yajima, Ichiro; Goto, Yuji; Ohgami, Nobutaka; Kato, Masashi; Takeda, Kozue

2016-01-01

The incidence of allergies has recently been increasing worldwide. Immunoglobulin E (IgE)-mediated hypersensitivity is central to the pathogenesis of asthma, hay fever and other allergic diseases. Ginger (Zingiber officinale Roscoe) and its extracts have been valued for their medical properties including antinausea, antiinflammation, antipyresis and analgesia properties. In this study, we investigated the antiallergic effects of ginger and 6-gingerol, a major compound of ginger, using a mouse allergy model and primary/cell line culture system. In mice with ovalbumin (OVA)-induced allergic rhinitis, oral administration of 2% ginger diet reduced the severity of sneezing and nasal rubbing by nasal sensitization of OVA and suppressed infiltration of mast cells in nasal mucosa and secretion of OVA-specific IgE in serum. 6-Gingerol inhibited the expression of not only Th2 cytokines but also Th1 cytokines in OVA-sensitized spleen cells. Accordingly, 6-gingerol suppressed in vitro differentiation of both Th1 cells and Th2 cells from naïve T cells. In addition, 6-gingerol suppressed both superantigen staphylococcal enterotoxin B (SEB)- and anti-CD3-induced T cell proliferation. 6-Gingerol also abrogated PMA plus ionomycin- and SEB-induced IL-2 production in T cells, suggesting that 6-gingerol affected T cell receptor-mediated signal transduction rather than the antigen-presentation process. Indeed, 6-gingerol inhibited the phosphorylation of MAP kinases, calcium release and nuclear localization of c-fos and NF-κB by PMA and ionomycin stimulation. Thus, our results demonstrate that 6-gingerol suppresses cytokine production for T cell activation and proliferation, thereby not causing B cell and mast cell activation and resulting in prevention or alleviation of allergic rhinitis symptoms. Copyright © 2015 Elsevier Inc. All rights reserved.

[Marketing role of corneal graft tissue donation to an eye bank and donors' socioeconomic profile].

PubMed

Farias, Roberta Jansen de Mello; Sousa, Luciene Barbosa de

2008-01-01

Penetrating keratoplasty has been the leading and the most successful type of transplant in the world, however corneal deficiency is a commom problem usually presented to corneal surgeons. Impact evaluation of the number of corneal graft donations to the Sorocaba Eye Bank after the implementation of a corneal graft procurement system; to draw the socioeconomic profile of corneal graft donors of the Sorocaba Eye Bank (SEB). Retrospective study on donations to SEB from its creation and after the development of media marketing. Prospective analysis of the socioeconomic profile of corneal graft donors by a questionnaire sent as letters to the families of the donors in a certain month. SEB began its work in 1971 by spreading need of organ donation through lectures in churches, shopping malls, community meetings, radio programs, television programs, etc. In the 70s, the number of retrieved corneal grafts was 1 or 2/month. Between 1984 - 1989 a procurement coordination team was trained to act in mortuaries and by 2000 they also began to work in public hospitals. In 1984 only 260 corneal grafts were retrieved. This number has been increasing to 2,778 corneal graft donations in 2004. The questionnaire was answered by 76 of the 93 donor families, with a response rate of 81.7%. Donor age had a mean of 65.1 +/- 14.7 y/o, forty-two (55.3%) were men. Educational level of the donor families was an important factor for organ donation, once 36.8% had concluded high school and 34.2% completed university. The great majority, sixty-three (82.9%) of the corneal grafts were donated through the efforts of the procurement coordination team. The role of the media and institutional credibility are mandatory for public commitment to organ donation. The proficiency of the procurement coordination team requires intensive training, as the results show that 82.9% donations were made thanks to their efforts.

Controlled lecithin release from a hierarchical architecture on blood-contacting surface to reduce hemolysis of stored red blood cells.

PubMed

Shi, Qiang; Fan, Qunfu; Ye, Wei; Hou, Jianwen; Wong, Shing-Chung; Xu, Xiaodong; Yin, Jinghua

2014-06-25

Hemolysis of red blood cells (RBCs) caused by implant devices in vivo and nonpolyvinyl chloride containers for RBC preservation in vitro has recently gained much attention. To develop blood-contacting biomaterials with long-term antihemolysis capability, we present a facile method to construct a hydrophilic, 3D hierarchical architecture on the surface of styrene-b-(ethylene-co-butylene)-b-styrene elastomer (SEBS) with poly(ethylene oxide) (PEO)/lecithin nano/microfibers. The strategy is based on electrospinning of PEO/lecithin fibers onto the surface of poly [poly(ethylene glycol) methyl ether methacrylate] [P(PEGMEMA)]-modified SEBS, which renders SEBS suitable for RBC storage in vitro. We demonstrate that the constructed 3D architecture is composed of hydrophilic micro- and nanofibers, which transforms to hydrogel networks immediately in blood; the controlled release of lecithin is achieved by gradual dissolution of PEO/lecithin hydrogels, and the interaction of lecithin with RBCs maintains the membrane flexibility and normal RBC shape. Thus, the blood-contacting surface reduces both mechanical and oxidative damage to RBC membranes, resulting in low hemolysis of preserved RBCs. This work not only paves new way to fabricate high hemocompatible biomaterials for RBC storage in vitro, but provides basic principles to design and develop antihemolysis biomaterials for implantation in vivo.

The Hammer Award is presented to KSC and 45th Space Wing.

NASA Technical Reports Server (NTRS)

1999-01-01

At a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex, the Hammer Award is presented to Kennedy Space Center and the 45th Space Wing. Among the attendees in the audience are (center) Center Director Roy D. Bridges Jr., flanked by (at left) Commander of the 45th Space Wing Brig. Gen. F. Randall Starbuck and (at right) Commander of the Air Force Space Command General Richard B. Myers. Standing second from right is NASA Administrator Daniel S. Goldin. At the far right is Morley Winograd, director of the National Partnership for Reinventing Government, who presented the award. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J- BOSC) Source Evaluation Board (SEB). Ed Gormel and Chris Fairey, co-chairs of the SEB, accepted the awards for the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base.

KSC-99pp0838

NASA Image and Video Library

1999-07-16

At a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex, the Hammer Award is presented to Kennedy Space Center and the 45th Space Wing. Among the attendees in the audience are (center) Center Director Roy D. Bridges Jr., flanked by (at left) Commander of the 45th Space Wing Brig. Gen. F. Randall Starbuck and (at right) Commander of the Air Force Space Command General Richard B. Myers. Standing second from right is NASA Administrator Daniel S. Goldin. At the far right is Morley Winograd, director of the National Partnership for Reinventing Government, who presented the award. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Ed Gormel and Chris Fairey, co-chairs of the SEB, accepted the awards for the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base

Comparison of Genotypes and Enterotoxin Genes Between Staphylococcus aureus Isolates from Blood and Nasal Colonizers in a Korean Hospital

PubMed Central

Peck, Kyong Ran; Baek, Jin Yang; Song, Jae-Hoon

2009-01-01

In this study, we investigated the genetic background of 70 Staphylococcus aureus isolates (36 methicillin-resistant S. aureus [MRSA] and 34 methicillin-susceptible S. aureus [MSSA]) obtained from blood at a Korean tertiary-care hospital, using spa typing, multilocus sequence typing, and SCCmec typing. In addition, the prevalence of enterotoxin (sea, seb, sec, sed, see, seg, seh, sei, and sek), tst, and pvl genes among the samples was assessed via polymerase chain reaction, and the results were compared with those of 95 isolates of S. aureus obtained from nasal swabs. All MRSA isolates from blood, except one, belonged to three major clones: sequence type (ST)5-MRSA-II, ST72-MRSA-II (or IVA), and ST239-MRSA-III, among which ST5-MRSA-II was the predominant clone. The prevalence of enterotoxin genes in the S. aureus isolates obtained from blood differed significantly from those from the nasal swabs for the sea, seb, sec, and seh gene. In particular, the seb and sec genes were detected exclusively in the MRSA isolates of ST5 or spa-CC002, thereby suggesting the co-adaptation of virulence genes with the genetic background and their contribution to biological fitness. PMID:19654937

Effect of bacterial collagenase on resin-dentin bonds degradation.

PubMed

Toledano, Manuel; Osorio, Raquel; Osorio, Estrella; Aguilera, Fátima S; Yamauti, Monica; Pashley, David H; Tay, Franklin

2007-12-01

The objective of this study is to evaluate the effect of a bacterial collagenase on the degradation of resin-dentin bonds. Human dentin surfaces were bonded with: an etch-&-rinse self-priming adhesive (SB), a two-step self-etching primer/adhesive (SEB), and a 1-step self-etching adhesive (OUB). Composite build-ups were constructed. The bonded teeth were stored (24 h, 3 months, 1 year) in distilled water or in a buffered bacterial collagenase solution. Half of the specimens were stored as intact bonded teeth (Indirect Exposure/IE). The other half were sectioned into beams prior to storage (Direct Exposure/DE). After storage the intact teeth were sectioned into beams and all specimens were tested for microtensile bond strengths (MTBS). ANOVA and multiple comparisons tests were performed. Fractographic analysis was performed by scanning electron microscopy. The inclusion of bacterial collagenase in the storing solution did not lower the MTBS values over those seen in specimens stored in water. SB and SEB bonds strength were equal, and were superior to OUB. After 3 months of DE, SB and OUB bonded specimens showed decreases in MTBS; similar reductions required 1 year for SEB/DE. MTBS did not decrease in IE specimens except for OUB. Resin and collagen dissolution were evident in DE groups after storing.

Determining suitability of Large Aperture Scintillometer for validating remote sensing based evapotranspiration maps

NASA Astrophysics Data System (ADS)

Paul, G.; Gowda, P. H.; Howell, T. A.; Basu, S.; Colaizzi, P. D.; Marek, T.

2013-12-01

Scintillation method is a relatively new technique for measuring the sensible heat and water fluxes over land surfaces. Path integrating capabilities of scintillometer over heterogeneous landscapes make it a potential tool for comparing the energy fluxes derived from remote sensing based energy balance algorithms. For this reason, scintillometer-derived evapotranspiration (ET) fluxes are being used to evaluate remote sensing based energy balance algorithms for their ability to estimate ET fluxes. However, LAS' (Large Aperture Scintillometer) ability to derive ET fluxes is not thoroughly tested. The objective of this study was to evaluate LAS- and Surface Energy Balance System (SEBS)-derived fluxes against lysimetric data to determine LAS' suitability for validating remote sensing based evapotranspiration (ET) maps. The study was conducted during the Bushland Evapotranspiration and Agricultural Remote sensing EXperiment - 2008 (BEAREX-08) at the USDA-ARS Conservation and Production Research Laboratory (CPRL), Bushland, Texas. SEBS was coded in a GIS environment to retrieve ET fluxes from the high resolution imageries acquired using airborne multispectral sensors. The CPRL has four large weighing lysimeters (3 m long x 3 m wide x 2.4 m deep), each located in the middle of approximately 5 ha fields, arranged in a block pattern. The two lysimeter fields located on the east (NE and SE) were managed under irrigated conditions, and the other two lysimeters on the west (NW and SW) were under dryland management. Each lysimeter field was equipped with an automated weather station that provided measurements for net radiation (Rn), Ts, soil heat flux (Go), Ta, relative humidity, and wind speed. During BEAREX08, the NE and SE fields were planted to cotton on May 21, and the NW and SW dryland lysimeters fields were planted to cotton on June 5. One LAS each was deployed across two large dryland lysimeter fields (NW and SW) and two large irrigated lysimeter fields (NE and SE). The structural parameter of refractive index of air was measured at 1-min interval and averaged at 15-min, and synchronized with weather station. The source area (footprint) of the surface energy fluxes were computed using a footprint model. ET fluxes were derived using LAS-estimated H as a residual from the energy balance equation. Comparison of SEBS- and LAS-derived ET fluxes were made against lysimetric data and performance of each method was discussed to determine the suitability of LAS for evaluating accuracy of remote sensing based ET maps.

[Comparison of two rat models of IgA nephropathy].

PubMed

Peng, Wei; Liu, Zheng-rong

2008-10-01

To study the methods for rapid establishment of rat models of IgA nephropathy. Forty female SD rats weighing 160-200 g were randomized into 3 groups. In group A, the rats received intravenous injection of staphylococcal enterotoxin B (SEB) and oral bovine serum albumin (BSA), and in group B, CCl4 was injected subcutaneously in addition to the above treatments; the rats in group C received no treatments to serve as the normal control group. The rats were sacrificed 10 and 14 weeks after the treatment for biochemical testing of the arterial blood and histopathological and IgA immunofluorescence examination of the renal tissues. The twenty-four-hour urine was collected at 10, 12, and 14 weeks after the treatments for detecting the urine proteins. Compared with the control group, the rats in groups A and B showed significantly increased serum creatinine, urine nitrogen and protein levels. Pathological examination of the renal tissue showed mild to moderate mesangial expansion and mesangial cell proliferation in groups A and B, without obvious difference between the two groups; but hematuria and proteinuria occurred earlier in group B with stronger IgA immunofluorescence than in group A. Both of the methods used in group A and group B can successfully induce IgA nephropathy in rats, but in group B, hematuria and urineprotein occurs earlier and IgA immunofluorescence is more stronger. Therefore intravenous SEB injection combined with oral BSA and subcutaneous CCl4 administration is a better method for time-efficient establishment of rat models of IgA nephropathy.

Mesenchymal stromal (stem) cells suppress pro-inflammatory cytokine production but fail to improve survival in experimental staphylococcal toxic shock syndrome.

PubMed

Kim, Hani; Darwish, Ilyse; Monroy, Maria-Fernanda; Prockop, Darwin J; Liles, W Conrad; Kain, Kevin C

2014-01-14

Toxic shock syndrome (TSS) is caused by an overwhelming host-mediated response to bacterial superantigens produced mainly by Staphylococcus aureus and Streptococcus pyogenes. TSS is characterized by aberrant activation of T cells and excessive release of pro-inflammatory cytokines ultimately resulting in capillary leak, septic shock, multiple organ dysfunction and high mortality rates. No therapeutic or vaccine has been approved by the U.S. Food and Drug Administration for TSS, and novel therapeutic strategies to improve clinical outcome are needed. Mesenchymal stromal (stem) cells (MSCs) are stromal cells capable of self-renewal and differentiation. Moreover, MSCs have immunomodulatory properties, including profound effects on activities of T cells and macrophages in specific contexts. Based on the critical role of host-derived immune mediators in TSS, we hypothesized that MSCs could modulate the host-derived proinflammatory response triggered by Staphylococcal enterotoxin B (SEB) and improve survival in experimental TSS. Effects of MSCs on proinflammatory cytokines in peripheral blood were measured in wild-type C57BL/6 mice injected with 50 μg of SEB. Effects of MSCs on survival were monitored in fatal experimental TSS induced by consecutive doses of D-galactosamine (10 mg) and SEB (10 μg) in HLA-DR4 transgenic mice. Despite significantly decreasing serum levels of IL-2, IL-6 and TNF induced by SEB in wild-type mice, human MSCs failed to improve survival in experimental TSS in HLA-DR4 transgenic mice. Similarly, a previously described downstream mediator of human MSCs, TNF-stimulated gene 6 (TSG-6), did not significantly improve survival in experimental TSS. Furthermore, murine MSCs, whether unstimulated or pre-treated with IFNγ, failed to improve survival in experimental TSS. Our results suggest that the immunomodulatory effects of MSCs are insufficient to rescue mice from experimental TSS, and that mediators other than IL-2, IL-6 and TNF are likely to play critical mechanistic roles in the pathogenesis of experimental TSS.

Comparative transcriptome analysis reveals different strategies for degradation of steam-exploded sugarcane bagasse by Aspergillus niger and Trichoderma reesei.

PubMed

Borin, Gustavo Pagotto; Sanchez, Camila Cristina; de Santana, Eliane Silva; Zanini, Guilherme Keppe; Dos Santos, Renato Augusto Corrêa; de Oliveira Pontes, Angélica; de Souza, Aline Tieppo; Dal'Mas, Roberta Maria Menegaldo Tavares Soares; Riaño-Pachón, Diego Mauricio; Goldman, Gustavo Henrique; Oliveira, Juliana Velasco de Castro

2017-06-30

Second generation (2G) ethanol is produced by breaking down lignocellulosic biomass into fermentable sugars. In Brazil, sugarcane bagasse has been proposed as the lignocellulosic residue for this biofuel production. The enzymatic cocktails for the degradation of biomass-derived polysaccharides are mostly produced by fungi, such as Aspergillus niger and Trichoderma reesei. However, it is not yet fully understood how these microorganisms degrade plant biomass. In order to identify transcriptomic changes during steam-exploded bagasse (SEB) breakdown, we conducted a RNA-seq comparative transcriptome profiling of both fungi growing on SEB as carbon source. Particular attention was focused on CAZymes, sugar transporters, transcription factors (TFs) and other proteins related to lignocellulose degradation. Although genes coding for the main enzymes involved in biomass deconstruction were expressed by both fungal strains since the beginning of the growth in SEB, significant differences were found in their expression profiles. The expression of these enzymes is mainly regulated at the transcription level, and A. niger and T. reesei also showed differences in TFs content and in their expression. Several sugar transporters that were induced in both fungal strains could be new players on biomass degradation besides their role in sugar uptake. Interestingly, our findings revealed that in both strains several genes that code for proteins of unknown function and pro-oxidant, antioxidant, and detoxification enzymes were induced during growth in SEB as carbon source, but their specific roles on lignocellulose degradation remain to be elucidated. This is the first report of a time-course experiment monitoring the degradation of pretreated bagasse by two important fungi using the RNA-seq technology. It was possible to identify a set of genes that might be applied in several biotechnology fields. The data suggest that these two microorganisms employ different strategies for biomass breakdown. This knowledge can be exploited for the rational design of enzymatic cocktails and 2G ethanol production improvement.

Development of an Arm Phantom for Testing Non-Invasive Blood Pressure Monitors

NASA Astrophysics Data System (ADS)

Anderson-Jackson, LaTecia D.

Approximately one in every three adults age 20 older are diagnosed with high blood pressure or hypertension. It is estimated that hypertension affects 78 million people in the United States, is equally prevalent in both men and woman (Crabtree, Stuart-Shor, & McAllister, 2013). In the United States, around 78% of people suffering from hypertension are aware of their condition, with only 68% using hypertensive medications to control their blood pressure (Writing Group et al., 2010). Clinically, blood pressure measurements may lack accuracy, which can be attributed to various factors, including device limitations, cuff mis-sizing and misplacement, white-coat effect, masked hypertension, and lifestyle factors. The development of an arm phantom to simulate physiologic properties of a human arm and arterial BP waveforms may allow us to better assess the accuracy of non-invasive blood pressure (NIBP) monitors. The objective of this study are to: (1) Develop an arm phantom to replicate physiological properties of the human arm, and (2) Incorporate the arm phantom into a mock circulatory flow loop to simulate different physiological blood pressure readings on the bench. A tissue mimicking material, styrene-ethylene-butylene-styrene (SEBS), a co-block polymer was used to develop the arm phantom for in-vitro testing. To determine the optimal mechanical properties for the arm phantom, individual arm components were isolated and tested. A protocol was developed to evaluate various components for optimal arm phantom development. Mechanical testing was conducted on 10%, 15%, and 20% SEBS gel samples for modulus of elasticity measurements in order to simulate physiological properties of the human arm. As a result of the SEBS polymer being a new material for this application, this investigation will contribute to resolving the limitations that occurred during experimentation. In this study, we demonstrated that although SEBS polymer may be an ideal material to use for simulating tissue, further research on the material properties should be conducted.

EXPERIMENTAL EVALUATION OF DEFORMATION AND CONSTRAINT CHARACTERISTICS IN PRECRACKED CHARPY AND OTHER THREE-POINT BEND SPECIMENS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nanstad, Randy K; Sokolov, Mikhail A; Merkle, John Graham

2007-01-01

To enable determination of the fracture toughness reference temperature, T0, with reactor pressure vessel surveillance specimens, the precracked Charpy (PCVN) three-point bend, SE(B), specimen is of interest. Compared with the 25-mm (1 in.) thick compact, 1TC(T), specimen, tests with the PCVN specimen (10x10x55 mm) have resulted in T0 temperatures as much as 40 XC lower (a so-called specimen bias effect). The Heavy-Section Steel Irradiation (HSSI) Program at Oak Ridge National Laboratory developed a two-part project to evaluate the C(T) versus PCVN differences, (1) calibration experiments concentrating on test practices, and (2) a matrix of transition range tests with various specimenmore » geometries and sizes, including 1T SE(B) and 1TC(T). The test material selected was a plate of A533 grade B class 1 steel. The calibration experiments included assessment of the computational validity of J-integral determinations, while the constraint characteristics of various specimen types and sizes were evaluated using key curves and notch strength determinations. The results indicate that J-integral solutions for the small PCVN specimen are comparable in terms of J-integral validity with 1T bend specimens. Regarding constraint evaluations, Phase I deformation is defined where plastic deformation is confined to crack tip plastic zone development, whereas Phase II deformation is defined where plastic hinging deformation develops. In Phase II deformation, the 0.5T SE(B) B B specimen (slightly larger than the PCVN specimen) consistently showed the highest constraint of all SE(B) specimens evaluated for constraint comparisons. The PCVN specimen begins the Phase II type of deformation at relatively low KR levels, with the result that KJc values above about 70 MPa m from precracked Charpy specimens are under extensive plastic hinging deformation.« less

Comparison of Methods for Estimating Evapotranspiration using Remote Sensing Data

NASA Astrophysics Data System (ADS)

Beamer, J. P.; Morton, C.; Huntington, J. L.; Pohll, G.

2010-12-01

Estimating the annual evapotranspiration (ET) in arid and semi-arid environments is important for managing water resources. In this study we use remote sensing methods to estimate ET from different areas located in western and eastern Nevada. Surface energy balance (SEB) and vegetation indices (VI) are two common methods for estimating ET using satellite data. The purpose of this study is to compare these methods for estimating annual ET and highlight strengths and weaknesses in both methods. The SEB approach used is based on the Mapping Evapotranspiration at high Resolution with Internalized Calibration (METRIC) model, which estimates ET as a residual of the energy balance. METRIC has been shown to produce accurate results in agricultural and riparian settings. The VI approach used is based on statistical relationships between annual ET and various VI’s. The VI approaches have also shown to produce fairly accurate estimates of ET for various vegetation types, however consideration for spatial variations in potential ET and precipitation amount are generally ignored, leading to restrictions in their application. In this work we develop a VI approach that considers the study area potential ET and precipitation amount and compare this approach to METRIC and flux tower estimates of annual ET for several arid phreatophyte shrubs and irrigated agriculture settings.

Synergistic effect of selectively distributed AlN/MWCNT hybrid fillers on the morphological, mechanical and thermal properties of polycarbonate/maleated poly[styrene-b-(ethylene-co-butylene)- b-styrene] triblock copolymer (SEBS-g-MA) composites

NASA Astrophysics Data System (ADS)

Xiao, Chao; Leng, Xinyu; Wang, Hui; Su, Zheng; Zhang, Xian; Chen, Lin; Zheng, Kang; Tian, Xingyou

2017-02-01

A quaternary nanocomposite polycarbonate (PC)- multi-walled carbon nanotubes (MWCNT)/SEBS-g-MA (SM)-AlN is prepared by controlling the selective distribution of nano-fillers via melt-blending. Through a two-step mixing method, surface modified AlN is selectively dispersed in the island-like SM phase; meanwhile, MWCNT acting as bridges are mainly located in the continuous phase of PC. This ‘island-bridge’ morphology is confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The selective localization results agree well with the theoretical predictions. Dynamic mechanical analysis (DMA) indicates that the addition of hybrid fillers improved the storage modulus selectively. Thermogravimetric analysis (TGA) shows that the thermal stability of the PC/SM blends increased significantly; the degradation kinetic has also been changed due to the synergistic effects of the fillers. This novel ‘island-bridge’ network contributes a higher thermal conductivity at low filler content as the effective thermal conductivity reached 0.72 W m-1 K-1, which is three times higher than that of 70PC/30SM. The experimental observations coincide well with the optimizing model results.

The staphylococcal enterotoxin (SE) family

PubMed Central

Krakauer, Teresa; Stiles, Bradley G

2013-01-01

Staphylococcus aureus plays an important role in numerous human cases of food poisoning, soft tissue, and bone infections, as well as potentially lethal toxic shock. This common bacterium synthesizes various virulence factors that include staphylococcal enterotoxins (SEs). These protein toxins bind directly to major histocompatibility complex class II on antigen-presenting cells and specific Vβ regions of T-cell receptors, resulting in potentially life-threatening stimulation of the immune system. Picomolar concentrations of SEs ultimately elicit proinflammatory cytokines that can induce fever, hypotension, multi-organ failure, and lethal shock. Various in vitro and in vivo models have provided important tools for studying the biological effects of, as well as potential vaccines/therapeutics against, the SEs. This review succinctly presents known physical and biological properties of the SEs, including various intervention strategies. In particular, SEB will often be portrayed as per biodefense concerns dating back to the 1960s. PMID:23959032

The role of inserted polymers in polymeric insulation materials: insights from QM/MD simulations.

PubMed

Li, Chunyang; Zhao, Hong; Zhang, Hui; Wang, Ying; Wu, Zhijian; Han, Baozhong

2018-02-28

In this study, we performed a quantum chemical molecular dynamics (QM/MD) simulation to investigate the space charge accumulation process in copolymers of polyethylene (PE) with ethylene acrylic acid (EAA), ethylene vinyl acetate (EVA), styrene-ethylene-butadiene-styrene (SEBS), and black carbon (BC). We predicted that BC, especially branched BC, would possess the highest electron affinity and is identified as the most promising filler in power cable insulation. Following incorporations of 0-4 high-energy electrons into the composites, branched BC exhibited the highest stability and almost all electrons were trapped by it. Therefore, PE was protected efficiently and BC can be considered as an efficient filler for high voltage cables and an inhibitor of tree formation. On the contrary, although EAA, EVA, and SEBS can trap high-energy electrons, the latter can be supersaturated in composites of EAA, EVA, and SEBS with PE. The inserted polymers was unavoidably destroyed following C-H and C-O bond cleavage, which results from the interactions and charge transfer between PE and inserted polymers. The content effects of -COOH, benzene, and -OCOCH 3 groups on the electron trapping, mobility and stability of PE were also investigated systematically. We hope this knowledge gained from this work will be helpful in understanding the role of inserted polymers and the growth mechanisms of electrical treeing in high voltage cable insulation.

Inhibitory effect of totarol on exotoxin proteins hemolysin and enterotoxins secreted by Staphylococcus aureus.

PubMed

Shi, Ce; Zhao, Xingchen; Li, Wenli; Meng, Rizeng; Liu, Zonghui; Liu, Mingyuan; Guo, Na; Yu, Lu

2015-10-01

Staphylococcus aureus (S. aureus) causes a wide variety of infections, which are of major concern worldwide. S. aureus produces multiple virulence factors, resulting in food infection and poisoning. These virulence factors include hyaluronidases, proteases, coagulases, lipases, deoxyribonucleases and enterotoxins. Among the extracellular proteins produced by S. aureus that contribute to pathogenicity, the exotoxins α-hemolysin, staphylococcal enterotoxin A (SEA) and staphylococcal enterotoxin B (SEB) are thought to be of major significance. Totarol, a plant extract, has been revealed to inhibit the proliferation of several pathogens effectively. However, there are no reports on the effects of totarol on the production of α-hemolysin, SEA or SEB secreted by S. aureus. The aim of this study was to evaluate the effects of totarol on these three exotoxins. Hemolysis assay, western blotting and real-time reverse transcriptase-PCR assay were performed to identify the influence of graded subinhibitory concentrations of totarol on the production of α-hemolysin and the two major enterotoxins, SEA and SEB, by S. aureus in a dose-dependent manner. Moreover, an enzyme linked immunosorbent assay showed that the TNF-α production of RAW264.7 cells stimulated by S. aureus supernatants was inhibited by subinhibitory concentrations of totarol. Form the data, we propose that totarol could potentially be used as a promising natural compound in the food and pharmaceutical industries.

Staphylococcal food poisoning caused by Staphylococcus argenteus harboring staphylococcal enterotoxin genes.

PubMed

Wakabayashi, Yuki; Umeda, Kaoru; Yonogi, Shinya; Nakamura, Hiromi; Yamamoto, Kaori; Kumeda, Yuko; Kawatsu, Kentaro

2018-01-16

Staphylococcal food poisoning (SFP) is caused by staphylococcal enterotoxins (SEs) preformed in food materials. SE genes are encoded on mobile genetic elements and are widely found across Staphylococcus species including S. argenteus, although most SFP cases are caused by S. aureus. S. argenteus, recently discriminated from S. aureus as a novel species, are non-pigmented staphylococci phenotypically related to S. aureus. In 2014 and 2015, two independent food poisoning cases occurred in Osaka, Japan, in which non-pigmented staphylococci were predominantly isolated. Several enterotoxin genes (seb, seg, sei, sem, sen, seo, and selu2) were found in their genome and the production of SEB was confirmed by reverse passive agglutination tests. The non-pigmented isolates from patients, food handlers, food, and cooking utensils all produced the same pulsed-field gel electrophoresis pattern. These non-pigmented isolates were coagulase-positive and biochemically identical to S. aureus. We performed further genetic analysis using nucA sequencing and multi-locus sequence typing, and identified these isolates as S. argenteus. We also found that seb was encoded on the Staphylococcus aureus pathogenicity island, while seg, sei, sem, sen, seo, and selu2 were encoded on the enterotoxin gene cluster. From these results, we concluded that the two food poisoning outbreaks were SFP cases caused by S. argenteus harboring SE genes. Copyright © 2017 Elsevier B.V. All rights reserved.

A New Strategy to Prepare Polymer-based Shape Memory Elastomers.

PubMed

Song, Shijie; Feng, Jiachun; Wu, Peiyi

2011-10-04

A new strategy that utilizes the microphase separation of block copolymer and phase transition of small molecules for preparing polymer-based shape memory elastomer has been proposed. According to this strategy, a novel kind of shape memory elastomer comprising styrene-b-(ethylene-co-butylene)-b-styrene (SEBS) and paraffin has been prepared. Because paraffins are midblock-selective molecules for SEBS, they will preferentially enter and swell EB blocks supporting paraffins as an excellent switch phase for shape memory effect. Microstructures of SEBS/paraffin composites have been characterized by transmission electron microscopy, polarized light microscopy, and differential scanning calorimetry. The composites demonstrate various phase morphologies with regard to different paraffin loading. It has been found that under low paraffin loading, all the paraffins precisely embed in and swell EB-rich domains. While under higher loading, part of the paraffins become free and a larger-scaled phase separation has been observed. However, within wide paraffin loadings, all composites show good shape fixing, shape recovery performances, and improved tensile properties. Compared to the reported methods for shape memory elastomers preparation, this method not only simplifies the fabrication procedure from raw materials to processing but also offers a controllable approach for the optimization of shape memory properties as well as balancing the rigidity and softness of the material. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Applying Signature Extraction and Classification Algorithms on Express on Profiles of CD Markers and Toll Like Receptors to Classify and Predict Exposures to Various Pathogens

DTIC Science & Technology

2016-02-10

gram positive bacteria) at various time points.  We carried  out carrying out gene expression analysis for SEB,  Dengue , Plague, VEE, Bot toxin, at...to confidently  identify transcriptional responses induced by bacteria (anthrax, plague, Brucella), toxins (CT, SEB,  BoNTA), or viruses ( Dengue , VEE...P, Celluzzi CM, Marovich M, Subramanian H, Eller M, Widjaja S, Palmer D, Porter K, Sun W, Burgess T: CD40 ligand enhances dengue viral infection of

Jupiter's Deep Cloud Structure Revealed Using Keck Observations of Spectrally Resolved Line Shapes

NASA Technical Reports Server (NTRS)

Bjoraker, G. L.; Wong, M.H.; de Pater, I.; Adamkovics, M.

2015-01-01

Technique: We present a method to determine the pressure at which significant cloud opacity is present between 2 and 6 bars on Jupiter. We use: a) the strength of a Fraunhofer absorption line in a zone to determine the ratio of reflected sunlight to thermal emission, and b) pressure- broadened line profiles of deuterated methane (CH3D) at 4.66 meters to determine the location of clouds. We use radiative transfer models to constrain the altitude region of both the solar and thermal components of Jupiter's 5-meter spectrum. Results: For nearly all latitudes on Jupiter the thermal component is large enough to constrain the deep cloud structure even when upper clouds are present. We find that Hot Spots, belts, and high latitudes have broader line profiles than do zones. Radiative transfer models show that Hot Spots in the North and South Equatorial Belts (NEB, SEB) typically do not have opaque clouds at pressures greater than 2 bars. The South Tropical Zone (STZ) at 32 degrees South has an opaque cloud top between 4 and 5 bars. From thermochemical models this must be a water cloud. We measured the variation of the equivalent width of CH3D with latitude for comparison with Jupiter's belt-zone structure. We also constrained the vertical profile of H2O in an SEB Hot Spot and in the STZ. The Hot Spot is very dry for a probability less than 4.5 bars and then follows the H2O profile observed by the Galileo Probe. The STZ has a saturated H2O profile above its cloud top between 4 and 5 bars.

Surface-layer turbulence, energy balance and links to atmospheric circulations over a mountain glacier in the French Alps

NASA Astrophysics Data System (ADS)

Litt, Maxime; Sicart, Jean-Emmanuel; Six, Delphine; Wagnon, Patrick; Helgason, Warren D.

2017-04-01

Over Saint-Sorlin Glacier in the French Alps (45° N, 6.1° E; ˜ 3 km2) in summer, we study the atmospheric surface-layer dynamics, turbulent fluxes, their uncertainties and their impact on surface energy balance (SEB) melt estimates. Results are classified with regard to large-scale forcing. We use high-frequency eddy-covariance data and mean air-temperature and wind-speed vertical profiles, collected in 2006 and 2009 in the glacier's atmospheric surface layer. We evaluate the turbulent fluxes with the eddy-covariance (sonic) and the profile method, and random errors and parametric uncertainties are evaluated by including different stability corrections and assuming different values for surface roughness lengths. For weak synoptic forcing, local thermal effects dominate the wind circulation. On the glacier, weak katabatic flows with a wind-speed maximum at low height (2-3 m) are detected 71 % of the time and are generally associated with small turbulent kinetic energy (TKE) and small net turbulent fluxes. Radiative fluxes dominate the SEB. When the large-scale forcing is strong, the wind in the valley aligns with the glacier flow, intense downslope flows are observed, no wind-speed maximum is visible below 5 m, and TKE and net turbulent fluxes are often intense. The net turbulent fluxes contribute significantly to the SEB. The surface-layer turbulence production is probably not at equilibrium with dissipation because of interactions of large-scale orographic disturbances with the flow when the forcing is strong or low-frequency oscillations of the katabatic flow when the forcing is weak. In weak forcing when TKE is low, all turbulent fluxes calculation methods provide similar fluxes. In strong forcing when TKE is large, the choice of roughness lengths impacts strongly the net turbulent fluxes from the profile method fluxes and their uncertainties. However, the uncertainty on the total SEB remains too high with regard to the net observed melt to be able to recommend one turbulent flux calculation method over another.

Estimation of Land Surface Energy Balance Using Satellite Data of Spatial Reduced Resolution

NASA Astrophysics Data System (ADS)

Vintila, Ruxandra; Radnea, Cristina; Savin, Elena; Poenaru, Violeta

2010-12-01

The paper presents preliminary results concerning the monitoring at national level of several geo-biophysical variables retrieved by remote sensing, in particular those related to drought or aridisation. The study, which is in progress, represents also an exercise for to the implementation of a Land Monitoring Core Service for Romania, according to the Kopernikus Program and in compliance with the INSPIRE Directive. The SEBS model has been used to retrieve land surface energy balance variables, such as turbulent heat fluxes, evaporative fraction and daily evaporation, based on three information types: (1) surface albedo, emissivity, temperature, fraction of vegetation cover (fCover), leaf area index (LAI) and vegetation height; (2) air pressure, temperature, humidity and wind speed at the planetary boundary layer (PBL) height; (3) downward solar radiation and downward longwave radiation. AATSR and MERIS archived reprocessed images have provided several types of information. Thus, surface albedo, emissivity, and land surface temperature have been retrieved from AATSR, while LAI and fCover have been estimated from MERIS. The vegetation height has been derived from CORINE Land Cover and PELCOM Land Use databases, while the meteorological information at the height of PBL have been estimated from the measurements provided by the national weather station network. Other sources of data used during this study have been the GETASSE30 digital elevation model with 30" spatial resolution, used for satellite image orthorectification, and the SIGSTAR-200 geographical information system of soil resources of Romania, used for water deficit characterisation. The study will continue by processing other AATSR and MERIS archived images, complemented by the validation of SEBS results with ground data collected on the most important biomes for Romania at various phenological stages, and the transformation of evaporation / evapotranspiration into a drought index using the soil texture data. It is also foreseen to develop procedures for processing near-real time AATSR and MERIS images from the rolling archives, as well as procedures for dealing with SENTINEL 3 images in the future, for timely delivery of reliable information to authorities and planning for drought to reduce its effects on citizens.

KSC-99pp0836

NASA Image and Video Library

1999-07-16

Morley Winograd (right), director of the National Partnership for Reinventing Government, presents the Hammer Award to Ed Gormel (left) and Chris Fairey (center) at a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Gormel and Fairey are co-chairs of the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base

KSC-99pp0835

NASA Image and Video Library

1999-07-16

Ed Gormel (left) and Chris Fairey (center) accept the Hammer Award at a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex. Presenting the award is Morley Winograd (right), director of the National Partnership for Reinventing Government. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Gormel and Fairey are co-chairs of the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base

Simultaneous Detection of Escherichia coli O157:H7, Salmonella enteritidis, and Listeria monocytogenes at a Very Low Level Using Simultaneous Enrichment Broth and Multichannel SPR Biosensor.

PubMed

Zhang, Xiaoguang; Tsuji, Sachiko; Kitaoka, Hayato; Kobayashi, Hiroshi; Tamai, Mitsuru; Honjoh, Ken-Ichi; Miyamoto, Takahisa

2017-10-01

Detection of foodborne pathogens at very low levels is still a challenge. A custom-built multichannel surface plasmon resonance (SPR) biosensor and simultaneous enrichment broth (SEB) were used to develop a simultaneous detection method for 3 important foodborne pathogens, Escherichia coli O157:H7 (O157:H7), Salmonella enteritidis, and Listeria monocytogenes, at a very low level. These 3 foodborne pathogens at a very low level (14, 6, and 28 CFU/25 g (mL) for O157:H7, S. enteritidis, and L. monocytogenes, respectively) were inoculated in SEB and incubated at 37 ˚C for 24 h. Sample prepared from the simultaneous enrichment culture was analyzed using the multichannel SPR biosensor and sensor chip immobilized with polyclonal antibodies specific to each of the target pathogens. O157:H7, S. enteritidis, and L. monocytogenes in chicken were detected simultaneously at an inoculum dose of 14, 6, and 28 CFU/25 g, respectively. Our method using a custom-built multichannel SPR biosensor and enrichment in SEB is expected as a rapid and simultaneous detection method for low levels of O157:H7, S. enteritidis, and L. monocytogenes in food. Our method is expected as a rapid and simultaneous detection method for pathogens at very low levels. It has great potential for safety control of food and microbiological detection applications. © 2017 Institute of Food Technologists®.

Surface energy budget and thermal inertia at Gale Crater: Calculations from ground-based measurements.

PubMed

Martínez, G M; Rennó, N; Fischer, E; Borlina, C S; Hallet, B; de la Torre Juárez, M; Vasavada, A R; Ramos, M; Hamilton, V; Gomez-Elvira, J; Haberle, R M

2014-08-01

The analysis of the surface energy budget (SEB) yields insights into soil-atmosphere interactions and local climates, while the analysis of the thermal inertia ( I ) of shallow subsurfaces provides context for evaluating geological features. Mars orbital data have been used to determine thermal inertias at horizontal scales of ∼10 4  m 2 to ∼10 7  m 2 . Here we use measurements of ground temperature and atmospheric variables by Curiosity to calculate thermal inertias at Gale Crater at horizontal scales of ∼10 2  m 2 . We analyze three sols representing distinct environmental conditions and soil properties, sol 82 at Rocknest (RCK), sol 112 at Point Lake (PL), and sol 139 at Yellowknife Bay (YKB). Our results indicate that the largest thermal inertia I  = 452 J m -2  K -1  s -1/2 (SI units used throughout this article) is found at YKB followed by PL with I  = 306 and RCK with I  = 295. These values are consistent with the expected thermal inertias for the types of terrain imaged by Mastcam and with previous satellite estimations at Gale Crater. We also calculate the SEB using data from measurements by Curiosity's Rover Environmental Monitoring Station and dust opacity values derived from measurements by Mastcam. The knowledge of the SEB and thermal inertia has the potential to enhance our understanding of the climate, the geology, and the habitability of Mars.

Surface energy budget and thermal inertia at Gale Crater: Calculations from ground-based measurements

PubMed Central

Martínez, G M; Rennó, N; Fischer, E; Borlina, C S; Hallet, B; de la Torre Juárez, M; Vasavada, A R; Ramos, M; Hamilton, V; Gomez-Elvira, J; Haberle, R M

2014-01-01

The analysis of the surface energy budget (SEB) yields insights into soil-atmosphere interactions and local climates, while the analysis of the thermal inertia (I) of shallow subsurfaces provides context for evaluating geological features. Mars orbital data have been used to determine thermal inertias at horizontal scales of ∼104 m2 to ∼107 m2. Here we use measurements of ground temperature and atmospheric variables by Curiosity to calculate thermal inertias at Gale Crater at horizontal scales of ∼102 m2. We analyze three sols representing distinct environmental conditions and soil properties, sol 82 at Rocknest (RCK), sol 112 at Point Lake (PL), and sol 139 at Yellowknife Bay (YKB). Our results indicate that the largest thermal inertia I = 452 J m−2 K−1 s−1/2 (SI units used throughout this article) is found at YKB followed by PL with I = 306 and RCK with I = 295. These values are consistent with the expected thermal inertias for the types of terrain imaged by Mastcam and with previous satellite estimations at Gale Crater. We also calculate the SEB using data from measurements by Curiosity's Rover Environmental Monitoring Station and dust opacity values derived from measurements by Mastcam. The knowledge of the SEB and thermal inertia has the potential to enhance our understanding of the climate, the geology, and the habitability of Mars. PMID:26213666

Water and Ammonia Abundances in Jupiter's South Equatorial Belt and Equatorial Zone at the time of Juno Perijoves 4 to 6

NASA Astrophysics Data System (ADS)

Bjoraker, G. L.; De Pater, I.; Wong, M. H.; Adamkovics, M.; Hewagama, T.; Orton, G.

2017-12-01

We used iSHELL on NASA's Infrared Telescope Facility and NIRSPEC on the Keck telescope concurrent with Juno perijoves 4-6 between February and May 2017 to obtain 5-micron spectra of Jupiter. Here we will focus on observations of the South Equatorial Belt and the Equatorial Zone. Spectrally resolved line profiles of CH3D, NH3, and H2O probe the 1 to 8-bar level of Jupiter's troposphere. This overlaps with the weighting functions for several channels of Juno's microwave radiometer. The profile of the CH3D lines at 4.66 microns is very broad in SEB Hot Spots due to collisions with up to 8 bars of H2, where unit optical depth occurs due to collision-induced H2 opacity. The extreme width of these CH3D features implies that the Hot Spots that we observed do not have significant cloud opacity for P > 2 bars. We will discuss the abundance of NH3 and gaseous H2O within SEB Hot Spots and other regions near the longitude of perijove for each Juno encounter. We had dry nights on Mauna Kea and a sufficient Doppler shift to detect H2O. We will compare line wings to derive H2O profiles in the 2 to 6-bar region. SEB Hot Spots are highly depleted in H2O for P < 5 bars with respect to zones.

Rapid and simultaneous detection of ricin, staphylococcal enterotoxin B and saxitoxin by chemiluminescence-based microarray immunoassay.

PubMed

Szkola, A; Linares, E M; Worbs, S; Dorner, B G; Dietrich, R; Märtlbauer, E; Niessner, R; Seidel, M

2014-11-21

Simultaneous detection of small and large molecules on microarray immunoassays is a challenge that limits some applications in multiplex analysis. This is the case for biosecurity, where fast, cheap and reliable simultaneous detection of proteotoxins and small toxins is needed. Two highly relevant proteotoxins, ricin (60 kDa) and bacterial toxin staphylococcal enterotoxin B (SEB, 30 kDa) and the small phycotoxin saxitoxin (STX, 0.3 kDa) are potential biological warfare agents and require an analytical tool for simultaneous detection. Proteotoxins are successfully detected by sandwich immunoassays, whereas competitive immunoassays are more suitable for small toxins (<1 kDa). Based on this need, this work provides a novel and efficient solution based on anti-idiotypic antibodies for small molecules to combine both assay principles on one microarray. The biotoxin measurements are performed on a flow-through chemiluminescence microarray platform MCR3 in 18 minutes. The chemiluminescence signal was amplified by using a poly-horseradish peroxidase complex (polyHRP), resulting in low detection limits: 2.9 ± 3.1 μg L(-1) for ricin, 0.1 ± 0.1 μg L(-1) for SEB and 2.3 ± 1.7 μg L(-1) for STX. The developed multiplex system for the three biotoxins is completely novel, relevant in the context of biosecurity and establishes the basis for research on anti-idiotypic antibodies for microarray immunoassays.

The GEWEX LandFlux project: Evaluation of model evaporation using tower-based and globally gridded forcing data

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCabe, M. F.; Ershadi, A.; Jimenez, C.

Determining the spatial distribution and temporal development of evaporation at regional and global scales is required to improve our understanding of the coupled water and energy cycles and to better monitor any changes in observed trends and variability of linked hydrological processes. With recent international efforts guiding the development of long-term and globally distributed flux estimates, continued product assessments are required to inform upon the selection of suitable model structures and also to establish the appropriateness of these multi-model simulations for global application. In support of the objectives of the Global Energy and Water Cycle Exchanges (GEWEX) LandFlux project, fourmore » commonly used evaporation models are evaluated against data from tower-based eddy-covariance observations, distributed across a range of biomes and climate zones. The selected schemes include the Surface Energy Balance System (SEBS) approach, the Priestley–Taylor Jet Propulsion Laboratory (PT-JPL) model, the Penman–Monteith-based Mu model (PM-Mu) and the Global Land Evaporation Amsterdam Model (GLEAM). Here we seek to examine the fidelity of global evaporation simulations by examining the multi-model response to varying sources of forcing data. To do this, we perform parallel and collocated model simulations using tower-based data together with a global-scale grid-based forcing product. Through quantifying the multi-model response to high-quality tower data, a better understanding of the subsequent model response to the coarse-scale globally gridded data that underlies the LandFlux product can be obtained, while also providing a relative evaluation and assessment of model performance. Using surface flux observations from 45 globally distributed eddy-covariance stations as independent metrics of performance, the tower-based analysis indicated that PT-JPL provided the highest overall statistical performance (0.72; 61 W m –2; 0.65), followed closely by GLEAM (0.68; 64 W m –2; 0.62), with values in parentheses representing the R 2, RMSD and Nash–Sutcliffe efficiency (NSE), respectively. PM-Mu (0.51; 78 W m –2; 0.45) tended to underestimate fluxes, while SEBS (0.72; 101 W m –2; 0.24) overestimated values relative to observations. A focused analysis across specific biome types and climate zones showed considerable variability in the performance of all models, with no single model consistently able to outperform any other. Results also indicated that the global gridded data tended to reduce the performance for all of the studied models when compared to the tower data, likely a response to scale mismatch and issues related to forcing quality. Rather than relying on any single model simulation, the spatial and temporal variability at both the tower- and grid-scale highlighted the potential benefits of developing an ensemble or blended evaporation product for global-scale LandFlux applications. Hence, challenges related to the robust assessment of the LandFlux product are also discussed.« less

The GEWEX LandFlux project: Evaluation of model evaporation using tower-based and globally gridded forcing data

DOE PAGES

McCabe, M. F.; Ershadi, A.; Jimenez, C.; ...

2016-01-26

Determining the spatial distribution and temporal development of evaporation at regional and global scales is required to improve our understanding of the coupled water and energy cycles and to better monitor any changes in observed trends and variability of linked hydrological processes. With recent international efforts guiding the development of long-term and globally distributed flux estimates, continued product assessments are required to inform upon the selection of suitable model structures and also to establish the appropriateness of these multi-model simulations for global application. In support of the objectives of the Global Energy and Water Cycle Exchanges (GEWEX) LandFlux project, fourmore » commonly used evaporation models are evaluated against data from tower-based eddy-covariance observations, distributed across a range of biomes and climate zones. The selected schemes include the Surface Energy Balance System (SEBS) approach, the Priestley–Taylor Jet Propulsion Laboratory (PT-JPL) model, the Penman–Monteith-based Mu model (PM-Mu) and the Global Land Evaporation Amsterdam Model (GLEAM). Here we seek to examine the fidelity of global evaporation simulations by examining the multi-model response to varying sources of forcing data. To do this, we perform parallel and collocated model simulations using tower-based data together with a global-scale grid-based forcing product. Through quantifying the multi-model response to high-quality tower data, a better understanding of the subsequent model response to the coarse-scale globally gridded data that underlies the LandFlux product can be obtained, while also providing a relative evaluation and assessment of model performance. Using surface flux observations from 45 globally distributed eddy-covariance stations as independent metrics of performance, the tower-based analysis indicated that PT-JPL provided the highest overall statistical performance (0.72; 61 W m –2; 0.65), followed closely by GLEAM (0.68; 64 W m –2; 0.62), with values in parentheses representing the R 2, RMSD and Nash–Sutcliffe efficiency (NSE), respectively. PM-Mu (0.51; 78 W m –2; 0.45) tended to underestimate fluxes, while SEBS (0.72; 101 W m –2; 0.24) overestimated values relative to observations. A focused analysis across specific biome types and climate zones showed considerable variability in the performance of all models, with no single model consistently able to outperform any other. Results also indicated that the global gridded data tended to reduce the performance for all of the studied models when compared to the tower data, likely a response to scale mismatch and issues related to forcing quality. Rather than relying on any single model simulation, the spatial and temporal variability at both the tower- and grid-scale highlighted the potential benefits of developing an ensemble or blended evaporation product for global-scale LandFlux applications. Hence, challenges related to the robust assessment of the LandFlux product are also discussed.« less

Automatic hammering of nano-patterns on special polymer film by using a vibrating AFM tip

PubMed Central

2012-01-01

Complicated nano-patterns with linewidth less than 18 nm can be automatically hammered by using atomic force microscopy (AFM) tip in tapping mode with high speed. In this study, the special sample was thin poly(styrene-ethylene/butylenes-styrene) (SEBS) block copolymer film with hexagonal spherical microstructures. An ordinary silicon tip was used as a nano-hammer, and the entire hammering process is controlled by a computer program. Experimental results demonstrate that such structure-tailored thin films enable AFM tip hammering to be performed on their surfaces. Both imprinted and embossed nano-patterns can be generated by using a vibrating tip with a larger tapping load and by using a predefined program to control the route of tip movement as it passes over the sample’s surface. Specific details for the fabrication of structure-tailored SEBS film and the theory for auto-hammering patterns were presented in detail. PMID:22889045

Isolation and characterization of anti-SEB peptides using magnetic sorting and bacterial peptide display library technology

NASA Astrophysics Data System (ADS)

Pennington, Joseph M.; Kogot, Joshua M.; Sarkes, Deborah A.; Pellegrino, Paul M.; Stratis-Cullum, Dimitra N.

2012-06-01

Peptide display libraries offer an alternative method to existing antibody development methods enabling rapid isolation of highly stable reagents for detection of new and emerging biological threats. Bacterial display libraries are used to isolate new peptide reagents within 1 week, which is simpler and timelier than using competing display library technology based on phage or yeast. Using magnetic sorting methods, we have isolated peptide reagents with high affinity and specificity to staphylococcal enterotoxin B (SEB), a suspected food pathogen. Flow cytometry methods were used for on-cell characterization and the binding affinity (Kd) of this new peptide reagent was determined to be 56 nm with minimal cross-reactivity to other proteins. These results demonstrated that magnetic sorting for new reagents using bacterial display libraries is a rapid and effective method and has the potential for current and new and emerging food pathogen targets.

KSC-99pp0832

NASA Image and Video Library

1999-07-16

At a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex, KSC and 45th Space Wing employees share the honors as recipients of the Hammer Award. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. Morley Winograd, director of the National Partnership for Reinventing Government, presented the award to Ed Gormel and Chris Fairey, co-chairs of the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the J-BOSC SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base

The Hammer Award is presented to KSC and 45th Space Wing.

NASA Technical Reports Server (NTRS)

1999-01-01

At a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex, KSC and 45th Space Wing employees share the honors as recipients of the Hammer Award. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. Morley Winograd, director of the National Partnership for Reinventing Government, presented the award to Ed Gormel and Chris Fairey, co-chairs of the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the J-BOSC SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base.

KSC-99pp0834

NASA Image and Video Library

1999-07-16

KSC's Director of Public Affairs Joe Gordon (left) applauds as Ed Gormel and Chris Fairey are named recipients of the Hammer Award at a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex. Presenting the award is Morley Winograd (at the podium), director of the National Partnership for Reinventing Government. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Gormel and Fairey are co-chairs of the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base

Study on W-band sheet-beam traveling-wave tube based on flat-roofed sine waveguide

NASA Astrophysics Data System (ADS)

Fang, Shuanzhu; Xu, Jin; Jiang, Xuebing; Lei, Xia; Wu, Gangxiong; Li, Qian; Ding, Chong; Yu, Xiang; Wang, Wenxiang; Gong, Yubin; Wei, Yanyu

2018-05-01

A W-band sheet electron beam (SEB) traveling-wave tube (TWT) based on flat-roofed sine waveguide slow-wave structure (FRSWG-SWS) is proposed. The sine wave of the metal grating is replaced by a flat-roofed sine wave around the electron beam tunnel. The slow-wave characteristics including the dispersion properties and interaction impedance have been investigated by using the eigenmode solver in the 3-D electromagnetic simulation software Ansoft HFSS. Through calculations, the FRSWG SWS possesses the larger average interaction impedance than the conventional sine waveguide (SWG) SWS in the frequency range of 86-110 GHz. The beam-wave interaction was studied and particle-in-cell simulation results show that the SEB TWT can produce output power over 120 W within the bandwidth ranging from 90 to 100 GHz, and the maximum output power is 226 W at typical frequency 94 GHz, corresponding electron efficiency of 5.89%.

KSC-99pp0831

NASA Image and Video Library

1999-07-16

Ed Gormel (left) and Chris Fairey (center) display the Hammer Award they received at a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. At the podium is Morley Winograd director of the National Partnership for Reinventing Government, who presented the award. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Fairey and Gormel are co-chairs of the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base

Suppression of cytokine release by fluticasone furoate vs. mometasone furoate in human nasal tissue ex-vivo.

PubMed

Zhang, Nan; Van Crombruggen, Koen; Holtappels, Gabriele; Lan, Feng; Katotomichelakis, Michail; Zhang, Luo; Högger, Petra; Bachert, Claus

2014-01-01

Topical glucocorticosteroids are the first line therapy for airway inflammation. Modern compounds with higher efficacy have been developed, but head-to-head comparison studies are sparse. To compare the activity of two intranasal glucocorticoids, fluticasone furoate (FF) and mometasone furoate (MF) with respect to the inhibition of T helper (Th)1, Th2 and Th17 cytokine release in airway mucosa. We used an ex-vivo human nasal mucosal tissue model and employed pre- and post- Staphylococcus aureus enterotoxin B (SEB)-challenge incubations with various time intervals and drug concentrations to mimic typical clinical situations of preventive or therapeutic use. At a fixed concentration of 10-10 M, FF had significantly higher suppressive effects on interferon (IFN)-γ, interleukin (IL)-2 and IL-17 release, but not IL-5 or tumor necrosis factor (TNF)-α, vs. MF. While the maximal suppressive activity was maintained when FF was added before or after tissue stimulation, the cytokine suppression capacity of MF appeared to be compromised when SEB-induced cell activation preceded the addition of the drug. In a pre-challenge incubation setting with removal of excess drug concentrations, MF approached inhibition of IL-5 and TNF-α after 6 and 24 hours while FF maximally blocked the release of these cytokines right after pre-incubation. Furthermore, FF suppressed a wider range of T helper cytokines compared to MF. The study demonstrates the potential of our human mucosal model and shows marked differences in the ability to suppress the release of various cytokines in pre- and post-challenge settings between FF and MF mimicking typical clinical situations of preventive or therapeutic use.

Virulence Factors of Staphylococcus aureus Isolates in an Iranian Referral Children's Hospital.

PubMed

Sabouni, Farah; Mahmoudi, Shima; Bahador, Abbas; Pourakbari, Babak; Sadeghi, Reihaneh Hosseinpour; Ashtiani, Mohammad Taghi Haghi; Nikmanesh, Bahram; Mamishi, Setareh

2014-04-01

The clinical importance of Staphylococcus aureus (S. aureus) is attributed to notable virulence factors, surface proteins, toxins, and enzymes as well as the rapid development of drug resistance. The aim of this study was to compare the occurrence of virulence factors produced by S. aureus strains isolated from children in an Iranian referral children's hospital. The presence of genes encoding for the enterotoxins A (sea), B (seb), C (sec), D (sed), TSST-1 (tsst), exfoliative toxin A (eta), and exfoliative toxin B (etb) were detected by Multiplex polymerase chain reaction (PCR) using specific primers. In addition, the standardized Kirby-Bauer disc-diffusion method was performed on Mueller-Hinton agar. In total, 133 S. aureus isolates were obtained from different patients. Of these S. aureus isolates, 64 (48%) were methicillin-resistant S. aureus (MRSA), and all of these tested positive for the mecA gene. Regarding the classical enterotoxin genes, sea gene (40.6%) was the most prevalent followed by seb (19.6%), tsst (12.8%), eta (11.3%), etb (9%), sed (4.5%), and sec (3%). Among methicillin-susceptible S. aureus (MSSA) isolates, seb and tsst were the more prevalent toxins in comparison with MRSA isolates (p < 0.05), while the frequency of sea, sed, eta, and etb genes were higher among MRSA isolates (p > 0.05). In our study enterotoxin A was produced by 40.6% of the isolates (48% from MRSA and 33% from MSSA isolates) which was higher than in previous reports. According to our results, strict hygiene and preventative measures during food processing are highly recommended.

Quantitative Analysis of Staphylococcal Enterotoxins A and B in Food Matrices Using Ultra High-Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS).

PubMed

Muratovic, Aida Zuberovic; Hagström, Thomas; Rosén, Johan; Granelli, Kristina; Hellenäs, Karl-Erik

2015-09-11

A method that uses mass spectrometry (MS) for identification and quantification of protein toxins, staphylococcal enterotoxins A and B (SEA and SEB), in milk and shrimp is described. The analysis was performed using a tryptic peptide, from each of the toxins, as the target analyte together with the corresponding (13)C-labeled synthetic internal standard peptide. The performance of the method was evaluated by analyzing spiked samples in the quantification range 2.5-30 ng/g (R² = 0.92-0.99). The limit of quantification (LOQ) in milk and the limit of detection (LOD) in shrimp was 2.5 ng/g, for both SEA and SEB toxins. The in-house reproducibility (RSD) was 8%-30% and 5%-41% at different concentrations for milk and shrimp, respectively. The method was compared to the ELISA method, used at the EU-RL (France), for milk samples spiked with SEA at low levels, in the quantification range of 2.5 to 5 ng/g. The comparison showed good coherence for the two methods: 2.9 (MS)/1.8 (ELISA) and 3.6 (MS)/3.8 (ELISA) ng/g. The major advantage of the developed method is that it allows direct confirmation of the molecular identity and quantitative analysis of SEA and SEB at low nanogram levels using a label and antibody free approach. Therefore, this method is an important step in the development of alternatives to the immune-assay tests currently used for staphylococcal enterotoxin analysis.

Polyclonal and allergen-induced cytokine responses in children with elevated immunoglobulin E but no atopic disease.

PubMed

Smart, J M; Tang, M L K; Kemp, A S

2002-11-01

Reduced Th1 and elevated Th2 cytokine responses are considered to be a principal mechanism in the generation of the inflammation leading to the manifestations of atopic disease in the skin of atopic dermatitis and in the airways of asthma. If reduced Th1 and elevated Th2 responses are principal determinants of the manifestation of atopic disease it might be expected that subjects with established disease would exhibit differences in their cytokine profiles as compared with atopic patients without clinical disease. To determine whether asymptomatic atopic children exhibit a cytokine imbalance similar to that seen in patients with established atopic disease or if they behave like non-atopic controls. Cytokine responses in a group of children with elevated IgE but no clinical manifestations of disease, atopic children with established disease and non-atopic controls were compared. We examined allergen-induced (house dust mite, HDM, rye grass pollen and RYE) cytokine responses in parallel with polyclonal (staphylococcal enterotoxin B, SEB) cytokine responses in a group of children with elevated serum IgE levels without current or past evidence of atopic disease (median age 6.6 years) and compared these with a non-atopic control group (median age 6.5 years) and a group of children with atopic disease (median age 6.7 years). Symptomatic atopic children had reduced SEB-induced IFN-gamma and increased SEB-induced IL-4 and IL-5 as compared with non-atopic controls. In contrast, SEB-induced IFN-gamma, IL-4 and IL-5 production in asymptomatic atopics was not significantly different from the non-atopic control subjects. Allergen-induced Th1 (IFN-gamma) and Th2 (IL-5 and IL-13) cytokine production was increased in both symptomatic atopics and asymptomatic atopics when compared with non-atopic controls. The defect in polyclonally induced IFN-gamma production was associated with the clinical manifestation of atopic disease but not the atopic stateper se. This suggests that the global reduction in IFN-gamma is the key determinant of the development of overt atopic disease. In contrast, elevated allergen-induced Th2 cytokine responses in children related to the atopic state per se irrespective of the presence of clinical atopic disease.

40 CFR 725.421 - Introduced genetic material.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Neurotoxin Staphylococcus aureus Alpha toxin (alpha lysin) Yersinia pestis Murine toxin Snake toxins Bungarus... aeruginosa Proteases Staphylococcus aureus Gamma lysin (Gamma toxin); Enterotoxins (SEA, SEB, SEC, SED SEE); Pyrogenic exotoxins A B; Toxic shock syndrome toxins (TSST-1) Staphylococcus aureus & Pseudomonas aeruginosa...

40 CFR 725.421 - Introduced genetic material.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Neurotoxin Staphylococcus aureus Alpha toxin (alpha lysin) Yersinia pestis Murine toxin Snake toxins Bungarus... aeruginosa Proteases Staphylococcus aureus Gamma lysin (Gamma toxin); Enterotoxins (SEA, SEB, SEC, SED SEE); Pyrogenic exotoxins A B; Toxic shock syndrome toxins (TSST-1) Staphylococcus aureus & Pseudomonas aeruginosa...

40 CFR 725.421 - Introduced genetic material.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Neurotoxin Staphylococcus aureus Alpha toxin (alpha lysin) Yersinia pestis Murine toxin Snake toxins Bungarus... aeruginosa Proteases Staphylococcus aureus Gamma lysin (Gamma toxin); Enterotoxins (SEA, SEB, SEC, SED SEE); Pyrogenic exotoxins A B; Toxic shock syndrome toxins (TSST-1) Staphylococcus aureus & Pseudomonas aeruginosa...

40 CFR 725.421 - Introduced genetic material.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Neurotoxin Staphylococcus aureus Alpha toxin (alpha lysin) Yersinia pestis Murine toxin Snake toxins Bungarus... aeruginosa Proteases Staphylococcus aureus Gamma lysin (Gamma toxin); Enterotoxins (SEA, SEB, SEC, SED SEE); Pyrogenic exotoxins A B; Toxic shock syndrome toxins (TSST-1) Staphylococcus aureus & Pseudomonas aeruginosa...

User-tailored seasonal forecasts for agriculture - creating socio-economic benefit through climate services in the Andes

NASA Astrophysics Data System (ADS)

De Ventura, Sara; Avalos, Grinia; Rossa, Andrea; Flubacher, Moritz; Gubler, Stefanie; Sedlmeier, Katrin; Dapozzo, Marlene; Garcia, Teresa; Quevedo, Karim; Liniger, Mark; Spirig, Christoph; Rosas, Gabriela; Schwierz, Cornelia

2017-04-01

The project Climandes is a twinning project between the Peruvian National Meteorological and Hydrological Service (SENAMHI) and the Federal Office of Meteorology and Climatology of Switzerland (MeteoSwiss) aiming at improving climate services for the Andean Region. It was launched in 2012 as a pilot project of the Global Framework for Climate Services (GFCS) of WMO. In 2016 a second phase of the project has started. Until now, Peru as all the Andean countries has had only a limited access to climate services, and the few instruments already in place have mostly not been developed in concordance with the user needs. Due to this mismatch, the opportunity to achieve veritable socio-economic benefits (SEB) has been overlooked so far. An additional difficulty is the lack of trained and experienced climatology and meteorology professionals able to develop and provide high quality climate services. Furthermore, the importance of climate information and its far-reaching benefits has not yet been fully acknowledged and embraced by the political decision-makers. The overall goals of the Climandes project are the following:. • Provision of user-tailored climate services for the Andean Region to improve socio- economic benefits for the agricultural sector and for society at large. • Improvement of the capacities of the meteorological service of Peru to generate user-tailored climate services in the agricultural sector. These goals are elaborated within three mutually dependent modules: The first one comprises user-tailored climate products for the agricultural sector in the Peruvian Andes. This includes drought and precipitation monitoring as well as the development of a prototype seasonal prediction system for the region including indices tailored to the agricultural sector. The second module focuses on capacity building, enabling climatology-related professionals and students to develop high-quality climate services for Peru and the Andean Region. Training courses as well as E-learning tools covering the knowledge needed for the elaboration and use of climate services (e.g. monitoring, seasonal prediction of precipitation) are developed and implemented. The third module aims at raising the awareness of political stakeholders of the SEB of SENAMHI's sector-specific climate services underpinned by a case study to quantify the SEB of drought and precipitation information platform for selected crops. This contribution will give an overview of the project and highlights some of the results of the first year of Climandes 2.

A single-stranded DNA aptamer that selectively binds to Staphylococcus aureus enterotoxin B.

PubMed

DeGrasse, Jeffrey A

2012-01-01

The bacterium Staphylococcus aureus is a common foodborne pathogen capable of secreting a cocktail of small, stable, and strain-specific, staphylococcal enterotoxins (SEs). Staphylococcal food poisoning (SFP) results when improperly handled food contaminated with SEs is consumed. Gastrointestinal symptoms of SFP include emesis, diarrhea and severe abdominal pain, which manifest within hours of ingesting contaminated food. Immuno-affinity based methods directly detect, identify, and quantify several SEs within a food or clinical sample. However, the success of these assays depends upon the availability of a monoclonal antibody, the development of which is non-trivial and costly. The current scope of the available immuno-affinity based methods is limited to the classical SEs and does not encompass all of the known or emergent SEs. In contrast to antibodies, aptamers are short nucleic acids that exhibit high affinity and specificity for their targets without the high-costs and ethical concerns of animal husbandry. Further, researchers may choose to freely distribute aptamers and develop assays without the proprietary issues that increase the per-sample cost of immuno-affinity assays. This study describes a novel aptamer, selected in vitro, with affinity to staphylococcal enterotoxin B (SEB) that may be used in lieu of antibodies in SE detection assays. The aptamer, designated APT(SEB1), successfully isolates SEB from a complex mixture of SEs with extremely high discrimination. This work sets the foundation for future aptamer and assay development towards the entire family of SEs. The rapid, robust, and low-cost identification and quantification of all of the SEs in S. aureus contaminated food is essential for food safety and epidemiological efforts. An in vitro generated library of SE aptamers could potentially allow for the comprehensive and cost-effective analysis of food samples that immuno-affinity assays currently cannot provide.

Development of surrogate endpoint biomarkers for clinical trials of cancer chemopreventive agents: relationships to fundamental properties of preinvasive (intraepithelial) neoplasia.

PubMed

Boone, C W; Kelloff, G J

1994-01-01

The tissue changes offering the greatest immediate potential for development as surrogate endpoint biomarkers (SEBs) to be used in Phase II trials of cancer chemopreventive agents are those derived from the microscopic tissue changes pathologists use to make the diagnosis of preinvasive (intraepithelial) neoplasia. These changes comprise four categories: proliferative index, ploidy, nuclear morphometry (size, shape, texture, and pleomorphism), and nucleolar morphometry (number, size, shape, position, and pleomorphism). Computer-assisted image analysis (CIA) permits dozens of additional morphometric parameters to be developed. Other categories of candidate SEBs are: DNA and chromosomal structural changes associated with genomic instability, activation of oncogenes and inactivation of tumor suppressor genes, structural changes in differentiated molecules, and aberrations of growth factor/receptor structure and function. Self-perpetuating DNA breakage with secondary mutator mutations in genomic stability genes is a major mechanism by which the genomic instability characteristic of neoplasia occurs, and from which stem other basic neoplastic properties, including clonal evolution, along multiple pathways of genetic variation that are stochastically determined, continuously increasing proliferation, rate and extent of phenotypic heterogeneity. SEBs resulting from genomic instability include homogeneously staining regions, double minute chromosomes, micronuclei, dicentrics, gene amplification, loss of heterozygosity, and alterations in chromosome number. Newly developed assays for detecting genomic instability include comparative genomic hybridization using fluorescence in situ hybridization on > 20 micron-thick sections monitored by confocal laser scanning microscopy, assays for microsatellite instability, and restriction landmark genomic scanning. These assays offer promise for detecting the earliest molecular changes of neoplasia in normal-appearing epithelium prior to the onset of the dysplastic phase of intraepithelial neoplasia.

Impaired CD23 and CD62L expression and tissue inhibitors of metalloproteinases secretion by eosinophils in adults with atopic dermatitis.

PubMed

de Oliveira Titz, T; Orfali, R L; de Lollo, C; Dos Santos, V G; da Silva Duarte, A J; Sato, M N; Aoki, V

2016-12-01

Eosinophils are multifunctional, polymorphonuclear leucocytes that secrete proteins within cytoplasmic granules, such as cytokines, chemokines, metalloproteinases (MMPs) and metalloproteinases tissue inhibitors (TIMPs). Although eosinophilia is a hallmark of atopic dermatitis (AD), several functional aspects of eosinophils remain unknown. We aimed to evaluate the phenotype and functional response of eosinophils under staphylococcal enterotoxin B (SEB) and Toll-like receptor (TLR)-2/6 (FSL-1) stimulation in the secretion of CCL5, MMPs and TIMPs in adults with AD. Forty-one adult patients with AD and 45 healthy controls enrolled for the study. Phenotype of eosinophils from granulocytes of peripheral blood was analysed by flow cytometry. We performed evaluation of CCL5 (cytometric bead array), MMP and TIMP (ELISA) secretion, in culture supernatants of purified eosinophils stimulated with SEB or TLR2/6 agonist (FSL-1). We found a higher frequency of LIN1 - CCR3 + eosinophils, and decreased expression of CD23 and CD62L receptors in eosinophils of AD patients. There was no difference in MMP and TIMP serum levels between the evaluated groups. However, we detected decreased basal levels of TIMP-1, TIMP-2 and CCL5 in culture supernatants from purified, unstimulated eosinophils from AD patients. In adults with AD, phenotypical features of eosinophils reveal decreased expression of early activation and L-selectin receptors. Regarding the functional profile of purified eosinophils related to tissue remodelling in atopic dermatitis, innate immune stimulation (TLR2/6 agonist and SEB) did not affect the ratio of MMP/TIMPs secretion in AD. Our findings reinforce the potential breakdown in tissue remodelling process mediated by eosinophils in AD. © 2016 European Academy of Dermatology and Venereology.

The reversal of the spontaneous exchange bias effect and zero-field-cooling magnetization in La1.5Sr0.5Co1-xFexMnO6: the effect of Fe doping.

PubMed

Zhang, H G; Xie, L; Liu, X C; Xiong, M X; Cao, L L; Li, Y T

2017-09-20

The crystal structure, electronic structure and magnetic properties were systematically studied in a series of Fe-doped La 1.5 Sr 0.5 CoMnO 6 double perovskites. The X-ray diffraction patterns of the samples are all refined with a rhombohedral (R3[combining macron]c) structure. The parameters a and c continuously increase with increasing Fe doping concentration x. X-ray photoelectron spectroscopy (XPS) spectra of the Mn, Co, and Fe 2p core levels, consistent with the soft X-ray absorption spectroscopy (XAS) spectra of Mn, Co, and Fe L 2,3 edges, indicate that their valence states are Mn 3+ and Mn 4+ , Co 2+ and Co 3+ , and Fe 3+ , respectively. However, relative to samples with x ≤ 0.1, there is an abrupt change of photon energy in the Co- and Fe-2p XAS spectra for x ≥ 0.2, implying the spin state transition is from high to low. In addition, this is further confirmed by a comparison between the calculated effective spin moment from the paramagnetic data and the theoretical value. Interestingly, we demonstrate the reversal of both zero-field-cooling magnetization and the sign switching of the spontaneous exchange bias (SEB) with the doping concentration from magnetic measurements. The magnetization reverses from positive to negative with the temperature decreasing across the compensation temperature at the critical concentration x = 0.2. Meanwhile, the exchange bias field of the SEB reverses from large negative values to positive ones. Our findings allow us to propose that the spin state transition caused by inhomogeneity is considered to play an important role in the reversal of the magnetization and the SEB effect.

Experimental and simulation studies of neutron-induced single-event burnout in SiC power diodes

NASA Astrophysics Data System (ADS)

Shoji, Tomoyuki; Nishida, Shuichi; Hamada, Kimimori; Tadano, Hiroshi

2014-01-01

Neutron-induced single-event burnouts (SEBs) of silicon carbide (SiC) power diodes have been investigated by white neutron irradiation experiments and transient device simulations. It was confirmed that a rapid increase in lattice temperature leads to formation of crown-shaped aluminum and cracks inside the device owing to expansion stress when the maximum lattice temperature reaches the sublimation temperature. SEB device simulation indicated that the peak lattice temperature is located in the vicinity of the n-/n+ interface and anode contact, and that the positions correspond to a hammock-like electric field distribution caused by the space charge effect. Moreover, the locations of the simulated peak lattice temperature agree closely with the positions of the observed destruction traces. Furthermore, it was theoretically demonstrated that the period of temperature increase of a SiC power device is two orders of magnitude less than that of a Si power device, using a thermal diffusion equation.

Effects of space radiation on electronic microcircuits

NASA Technical Reports Server (NTRS)

Kolasinski, W. A.

1989-01-01

The single event effects or phenomena (SEP), which so far have been observed as events falling on one or another of the SE classes: Single Event Upset (SEU), Single Event Latchup (SEL) and Single Event Burnout (SEB), are examined. Single event upset is defined as a lasting, reversible change in the state of a multistable (usually bistable) electronic circuit such as a flip-flop or latch. In a computer memory, SEUs manifest themselves as unexplained bit flips. Since latchup is in general caused by a single event of short duration, the single event part of the SEL term is superfluous. Nevertheless, it is used customarily to differentiate latchup due to a single heavy charged particle striking a sensitive cell from more ordinary kinds of latchup. Single event burnout (SEB) refers usually to total instantaneous failure of a power FET when struck by a single particle, with the device shorting out the power supply. An unforeseen failure of these kinds can be catastrophic to a space mission, and the possibilities are discussed.

Identifying the Source of Large-Scale Atmospheric Variability in Jupiter

NASA Astrophysics Data System (ADS)

Orton, Glenn

2011-01-01

We propose to use the unique mid-infrared filtered imaging and spectroscopic capabilities of the Subaru COMICS instrument to determine the mechanisms associated with recent unusual rapid albedo and color transformations of several of Jupiter's bands, particularly its South Equatorial Belt (SEB), as a means to understand the coupling between its dynamics and chemistry. These observations will characterize the temperature, degree of cloud cover, and distribution of minor gases that serve as indirect tracers of vertical motions in regions that will be undergoing unusual large-scale changes in dynamics and chemistry: the SEB, as well as regions near the equator and Jupiter's North Temperate Belt. COMICS is ideal for this investigation because of its efficiency in doing both imaging and spectroscopy, its 24.5-mum filter that is unique to 8-meter-class telescopes, its wide field of view that allows imaging of nearly all of Jupiter's disk, coupled with a high diffraction-limited angular resolution and optimal mid-infrared atmospheric transparency.

[Study of the mucociliary transport rate in evaluating the effectiveness of the treatment of suppurative endobronchitis by CO2 laser].

PubMed

Shesterina, M V; Khaĭtun, A A; Kirchik, O P

1990-01-01

The rate of mucociliary transport (MCT) in dogs with an experimental pulmonary tuberculosis and concurrent suppurative endobronchitis (SEB) and just with the latter was measured. The treatment effect was achieved by an endobronchial radiation with a CO2-laser unfocused beam of 3.56 and 5.3 w/cm2 power density, and the dogs in the control group were subjected to an endobronchial introduction of furagin. A comparison of the endoscopic picture and MCT rate findings made it possible to believe that the latter index appeared to be more reliable than a visual inspection of the bronchial mucous membrane. An active specific process in the lungs brings about MCT rate inhibition while the concurrent SEB aggravates these changes to a great extent. The radiation of the bronchial mucous membrane with the CO2-laser unfocused beam produces an immediate positive effect on MCT rate normalization. Better results were observed at a power density of 3.56 w/cm2.

Medium-energy heavy-ion single-event-burnout imaging of power MOSFETs

NASA Astrophysics Data System (ADS)

Musseau, O.; Torres, A.; Campbell, A. B.; Knudson, A. R.; Buchner, S.; Fischer, B.; Schlogl, M.; Briand, P.

1999-12-01

We present the first experimental determination of the SEB sensitive area in a power MOSFET irradiated with a high-LET heavy-ion microbeam. We used a spectroscopy technique to perform coincident measurements of the charge collected in both source and drain junctions together, with a nondestructive technique (current limitation). The resulting charge collection images are related to the physical structure of the individual cells. These experimental data reveal the complex 3-dimensional behavior of a real structure, which can not easily be simulated using available tools. As the drain voltage is increased, the onset of burnout is reached, characterized by a sudden change in the charge collection image. "Hot spots" are observed where the collected charge reaches its maximum value. Those spots, due to burnout triggering events, correspond to areas where the silicon is degraded through thermal effects along a single ion track. This direct observation of SEB sensitive areas as applications for, either device hardening, by modifying doping profiles or layout of the cells, or for code calibration and device simulation.

Binding and activation of major histocompatibility complex class II-deficient macrophages by staphylococcal exotoxins

NASA Technical Reports Server (NTRS)

Beharka, A. A.; Armstrong, J. W.; Iandolo, J. J.; Chapes, S. K.; Spooner, B. S. (Principal Investigator)

1994-01-01

Macrophages from C2D transgenic mice deficient in the expression of major histocompatibility complex (MHC) class II proteins were used to identify binding sites for superantigens distinct from the MHC class II molecule. Iodinated staphylococcal enterotoxins A and B (SEA and SEB) and exfoliative toxins A and B (ETA and ETB) bound to C2D macrophages in a concentration-dependent and competitive manner. All four toxins increased F-actin concentration within 30 s of their addition to C2D macrophages, indicating that signal transduction occurred in response to toxin in the absence of class II MHC. Furthermore, ETA, ETB, SEA, and, to a lesser extent, SEB induced C2D macrophages to produce interleukin 6. Several molecular species on C2D macrophages with molecular masses of 140, 97, 61, 52, 43, and 37 kDa bound SEA in immunoprecipitation experiments. These data indicate the presence of novel, functionally active toxin binding sites on murine macrophages distinct from MHC class II molecules.

The Hammer Award is presented to KSC and 45th Space Wing.

NASA Technical Reports Server (NTRS)

1999-01-01

KSC's Director of Public Affairs Joe Gordon (left) applauds as Ed Gormel and Chris Fairey are named recipients of the Hammer Award at a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex. Presenting the award is Morley Winograd (at the podium), director of the National Partnership for Reinventing Government. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Gormel and Fairey are co-chairs of the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base.

KSC-99pp0837

NASA Image and Video Library

1999-07-16

At a special presentation in the IMAX 2 Theater in the Kennedy Space Center Visitor Complex, the Hammer Award is presented to Kennedy Space Center and the 45th Space Wing. Present for the awards are (left to right) Commander of the Air Force Space Command General Richard B. Myers, Ed Gormel, Chris Fairey, NASA Administrator Daniel Goldin, and Director of the National Partnership for Reinventing Government, Morley Winograd, who presented the award. The Hammer Award is Vice President Al Gore's special recognition of teams of federal employees who have made significant contributions in support of the principles of the National Partnership for Reinventing Government. This Hammer Award acknowledges the accomplishments of a joint NASA and Air Force team that established the Joint Base Operations and Support Contract (J-BOSC) Source Evaluation Board (SEB). Gormel and Fairey are co-chairs of the SEB. The team developed and implemented the acquisition strategy for establishing a single set of base operations and support service requirements for KSC, Cape Canaveral Air Station and Patrick Air Force Base

Coupling of snow and permafrost processes using the Basic Modeling Interface (BMI)

NASA Astrophysics Data System (ADS)

Wang, K.; Overeem, I.; Jafarov, E. E.; Piper, M.; Stewart, S.; Clow, G. D.; Schaefer, K. M.

2017-12-01

We developed a permafrost modeling tool based by implementing the Kudryavtsev empirical permafrost active layer depth model (the so-called "Ku" component). The model is specifically set up to have a basic model interface (BMI), which enhances the potential coupling to other earth surface processes model components. This model is accessible through the Web Modeling Tool in Community Surface Dynamics Modeling System (CSDMS). The Kudryavtsev model has been applied for entire Alaska to model permafrost distribution at high spatial resolution and model predictions have been verified by Circumpolar Active Layer Monitoring (CALM) in-situ observations. The Ku component uses monthly meteorological forcing, including air temperature, snow depth, and snow density, and predicts active layer thickness (ALT) and temperature on the top of permafrost (TTOP), which are important factors in snow-hydrological processes. BMI provides an easy approach to couple the models with each other. Here, we provide a case of coupling the Ku component to snow process components, including the Snow-Degree-Day (SDD) method and Snow-Energy-Balance (SEB) method, which are existing components in the hydrological model TOPOFLOW. The work flow is (1) get variables from meteorology component, set the values to snow process component, and advance the snow process component, (2) get variables from meteorology and snow component, provide these to the Ku component and advance, (3) get variables from snow process component, set the values to meteorology component, and advance the meteorology component. The next phase is to couple the permafrost component with fully BMI-compliant TOPOFLOW hydrological model, which could provide a useful tool to investigate the permafrost hydrological effect.

Detection and Measurement of Staphylococcal Enterotoxin-Like K (SEl-K) Secretion by Staphylococcus aureus Clinical Isolates

PubMed Central

Aguilar, Jorge L.; Varshney, Avanish K.; Wang, Xiaobo; Stanford, Lindsay; Scharff, Matthew

2014-01-01

Staphylococcal enterotoxin-like K (SEl-K) is a potent mitogen that elicits T-cell proliferation and cytokine production at very low concentrations. However, unlike the classical enterotoxins SEB and toxic shock syndrome toxin 1 (TSST-1), the gene for SEl-K is commonly present in more than half of all Staphylococcus aureus clinical isolates and is present in almost all USA300 community-acquired methicillin-resistant S. aureus (CA-MRSA) isolates. Sequencing of the sel-k gene in over 20 clinical isolates and comparative analysis with all 14 published sel-k sequences indicate that there are at least 6 variants of the sel-k gene, including one that is conserved among all examined USA300 strains. Additionally, we have developed a highly sensitive enzyme-linked immunosorbent assay (ELISA) that specifically detects and measures SEl-K protein in culture supernatants and biological fluids. Quantification of in vitro SEl-K secretion by various S. aureus isolates using this novel capture ELISA revealed detectable amounts of SEl-K secretion by all isolates, with the highest secretion levels being exhibited by MRSA strains that coexpress SEB. In vivo secretion was measured in a murine thigh abscess model, where similar levels of SEl-K accumulation were noted regardless of whether the infecting strain exhibited high or low secretion of SEl-K in vitro. We conclude that SEl-K is commonly expressed in the setting of staphylococcal infection, in significant amounts. SEl-K should be further explored as a target for passive immunotherapy against complicated S. aureus infection. PMID:24808237

A tripartite cocktail of chimeric monoclonal antibodies passively protects mice against ricin, staphylococcal enterotoxin B and Clostridium perfringens epsilon toxin.

PubMed

Sully, Erin K; Whaley, Kevin; Bohorova, Natasha; Bohorov, Ognian; Goodman, Charles; Kim, Do; Pauly, Michael; Velasco, Jesus; Holtsberg, Frederick W; Stavale, Eric; Aman, M Javad; Tangudu, Chandra; Uzal, Francisco A; Mantis, Nicholas J; Zeitlin, Larry

2014-12-15

Due to the fast-acting nature of ricin, staphylococcal enterotoxin B (SEB), and Clostridium perfringens epsilon toxin (ETX), it is necessary that therapeutic interventions following a bioterrorism incident by one of these toxins occur as soon as possible after intoxication. Moreover, because the clinical manifestations of intoxication by these agents are likely to be indistinguishable from each other, especially following aerosol exposure, we have developed a cocktail of chimeric monoclonal antibodies that is capable of neutralizing all three toxins. The efficacy of this cocktail was demonstrated in mouse models of lethal dose toxin challenge. Copyright © 2014 Elsevier Ltd. All rights reserved.

Integrating Remote Sensing Information Into A Distributed Hydrological Model for Improving Water Budget Predictions in Large-scale Basins through Data Assimilation.

PubMed

Qin, Changbo; Jia, Yangwen; Su, Z; Zhou, Zuhao; Qiu, Yaqin; Suhui, Shen

2008-07-29

This paper investigates whether remote sensing evapotranspiration estimates can be integrated by means of data assimilation into a distributed hydrological model for improving the predictions of spatial water distribution over a large river basin with an area of 317,800 km2. A series of available MODIS satellite images over the Haihe River basin in China are used for the year 2005. Evapotranspiration is retrieved from these 1×1 km resolution images using the SEBS (Surface Energy Balance System) algorithm. The physically-based distributed model WEP-L (Water and Energy transfer Process in Large river basins) is used to compute the water balance of the Haihe River basin in the same year. Comparison between model-derived and remote sensing retrieval basin-averaged evapotranspiration estimates shows a good piecewise linear relationship, but their spatial distribution within the Haihe basin is different. The remote sensing derived evapotranspiration shows variability at finer scales. An extended Kalman filter (EKF) data assimilation algorithm, suitable for non-linear problems, is used. Assimilation results indicate that remote sensing observations have a potentially important role in providing spatial information to the assimilation system for the spatially optical hydrological parameterization of the model. This is especially important for large basins, such as the Haihe River basin in this study. Combining and integrating the capabilities of and information from model simulation and remote sensing techniques may provide the best spatial and temporal characteristics for hydrological states/fluxes, and would be both appealing and necessary for improving our knowledge of fundamental hydrological processes and for addressing important water resource management problems.

Integrating Remote Sensing Information Into A Distributed Hydrological Model for Improving Water Budget Predictions in Large-scale Basins through Data Assimilation

PubMed Central

Qin, Changbo; Jia, Yangwen; Su, Z.(Bob); Zhou, Zuhao; Qiu, Yaqin; Suhui, Shen

2008-01-01

This paper investigates whether remote sensing evapotranspiration estimates can be integrated by means of data assimilation into a distributed hydrological model for improving the predictions of spatial water distribution over a large river basin with an area of 317,800 km2. A series of available MODIS satellite images over the Haihe River basin in China are used for the year 2005. Evapotranspiration is retrieved from these 1×1 km resolution images using the SEBS (Surface Energy Balance System) algorithm. The physically-based distributed model WEP-L (Water and Energy transfer Process in Large river basins) is used to compute the water balance of the Haihe River basin in the same year. Comparison between model-derived and remote sensing retrieval basin-averaged evapotranspiration estimates shows a good piecewise linear relationship, but their spatial distribution within the Haihe basin is different. The remote sensing derived evapotranspiration shows variability at finer scales. An extended Kalman filter (EKF) data assimilation algorithm, suitable for non-linear problems, is used. Assimilation results indicate that remote sensing observations have a potentially important role in providing spatial information to the assimilation system for the spatially optical hydrological parameterization of the model. This is especially important for large basins, such as the Haihe River basin in this study. Combining and integrating the capabilities of and information from model simulation and remote sensing techniques may provide the best spatial and temporal characteristics for hydrological states/fluxes, and would be both appealing and necessary for improving our knowledge of fundamental hydrological processes and for addressing important water resource management problems. PMID:27879946

Reliability Concerns for Flying SiC Power MOSFETs in Space

NASA Technical Reports Server (NTRS)

Galloway, K. F.; Witulski, A. F.; Schrimpf, R. D.; Sternberg, A. L.; Ball, D. R.; Javanainen, A.; Reed, R. A.; Sierawski, B. D.; Lauenstein, J.-M.

2018-01-01

SiC power MOSFETs are space-ready in terms of typical reliability measures. However, single event burnout (SEB) often occurs at voltages 50% or lower than specified breakdown. Data illustrating burnout for 1200 V devices is reviewed and the space reliability of SiC MOSFETs is discussed.

7 CFR Exhibit B to Subpart A of... - Requirements for Modular/Panelized Housing Units

Code of Federal Regulations, 2013 CFR

2013-01-01

... Regional Letters of Acceptance (RLA), Truss Connector Bulletins (TCB): and, Mechanical Engineering... issued by HUD include: Structural Engineering Bulletins (SEB) on a national basis, Area Letters of... Category III housing (modular/panelized housing that does not have to have a Structural Engineering...

7 CFR Exhibit B to Subpart A of... - Requirements for Modular/Panelized Housing Units

Code of Federal Regulations, 2014 CFR

2014-01-01

... Regional Letters of Acceptance (RLA), Truss Connector Bulletins (TCB): and, Mechanical Engineering... issued by HUD include: Structural Engineering Bulletins (SEB) on a national basis, Area Letters of... Category III housing (modular/panelized housing that does not have to have a Structural Engineering...

7 CFR Exhibit B to Subpart A of... - Requirements for Modular/Panelized Housing Units

Code of Federal Regulations, 2012 CFR

2012-01-01

... Regional Letters of Acceptance (RLA), Truss Connector Bulletins (TCB): and, Mechanical Engineering... issued by HUD include: Structural Engineering Bulletins (SEB) on a national basis, Area Letters of... Category III housing (modular/panelized housing that does not have to have a Structural Engineering...

Development of Ultrafiltration Membrane-Separation Technology for Energy-Efficient Water Treatment and Desalination Process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yim, Woosoon; Bae, Chulsung

The growing scarcity of fresh water is a major political and economic challenge in the 21st century. Compared to thermal-based distillation technique of water production, pressure driven membrane-based water purification process, such as ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO), can offer more energy-efficient and environmentally friendly solution to clean water production. Potential applications also include removal of hazardous chemicals (i.e., arsenic, pesticides, organics) from water. Although those membrane-separation technologies have been used to produce drinking water from seawater (desalination) and non-traditional water (i.e., municipal wastewater and brackish groundwater) over the last decades, they still have problems in ordermore » to be applied in large-scale operations. Currently, a major huddle of membrane-based water purification technology for large-scale commercialization is membrane fouling and its resulting increases in pressure and energy cost of filtration process. Membrane cleaning methods, which can restore the membrane properties to some degree, usually cause irreversible damage to the membranes. Considering that electricity for creating of pressure constitutes a majority of cost (~50%) in membrane-based water purification process, the development of new nano-porous membranes that are more resistant to degradation and less subject to fouling is highly desired. Styrene-ethylene/butylene-styrene (SEBS) block copolymer is one of the best known block copolymers that induces well defined morphologies. Due to the polarity difference of aromatic styrene unit and saturated ethylene/butylene unit, these two polymer chains self-assemble each other and form different phase-separated morphologies depending on the ratios of two polymer chain lengths. Because the surface of SEBS is hydrophobic which easily causes fouling of membrane, incorporation of ionic group (e,g, sulfonate) to the polymer is necessary to reduces fouling. Recently, sulfonated SEBS became commercially available and has been extensively explored for membrane-mediated water purification technology. The sulfonated block copolymer creates a well developed nano-sale phase-separated morphologies composed of hydrophilic domains (sulfonated polystyrene) and hydrophobic domains (polyethylene/polybutylene). The hydrophilic domains determines transport properties (water transport, salt and/or ion rejection, etc) and the hydrophobic domains provides mechanical stability of the membrane. Unfortunately, a high degree of sulfonation of SEBS induces excessive swelling and deterioration of mechanical stability of the membrane. In an effort to develop robust polymeric membrane materials for water purification technology, phosphonic acid-functionalized SEBS membranes are investigated during this report period. In compare to sulfonated polymers, the corresponding phosphonated polymers are known to swell less because of the formation of extensive hydrogen bonding networks between phosphonates. In addition to the expected better mechanical stability, phosphonated polymers has another advantage over sulfonated polymers for the use water purification membrane; each phosphonate can accommodate two ions while each sulfonate accommodates only one ion. Membrane properties (ion type, ionic density, etc) of new membranes will be studied and their separation performance will be evaluated in water purification and desalination process. Through systematic study of the relationship of chemical structure–surface property–membrane performance, we aim to better understand the nature of membrane fouling and develop more fouling-resistant water purification membranes. The basic understanding of this relationship will lead to the development of advanced membrane materials which can offer a solution to environmentally sustainable production of fresh water.« less

Update on Staphylococcal Superantigen-Induced Signaling Pathways and Therapeutic Interventions

PubMed Central

Krakauer, Teresa

2013-01-01

Staphylococcal enterotoxin B (SEB) and related bacterial toxins cause diseases in humans and laboratory animals ranging from food poisoning, acute lung injury to toxic shock. These superantigens bind directly to the major histocompatibility complex class II molecules on antigen-presenting cells and specific Vβ regions of T-cell receptors (TCR), resulting in rapid hyper-activation of the host immune system. In addition to TCR and co-stimulatory signals, proinflammatory mediators activate signaling pathways culminating in cell-stress response, activation of NFκB and mammalian target of rapamycin (mTOR). This article presents a concise review of superantigen-activated signaling pathways and focuses on the therapeutic challenges against bacterial superantigens. PMID:24064719

Social Acceptability of Five Screening Instruments for Social, Emotional, and Behavioral Challenges

ERIC Educational Resources Information Center

Harrison, Judith R.; Vannest, Kimberly J.; Reynolds, Cecil R.

2013-01-01

Social, emotional, and behavioral (SEB) screening occurs in only two percent of our schools. This is unfortunate because universal screening is linked to prevention and early intervention with emotional and behavioral disorders (EBD) in children and youth, a population who continues to experience a plethora of poor outcomes. The social…

Life Satisfaction among High School Students with Social, Emotional, and Behavioral Problems

ERIC Educational Resources Information Center

State, Talida M.; Kern, Lee

2017-01-01

Over the last decade, there has been increased interest in measuring life satisfaction among children and adolescents as an indicator of broad well-being and happiness. Although limited, existing research with students with social, emotional, and behavioral (SEB) problems indicates they experience lower life satisfaction compared with their…

Factors Influencing Candidates' Performance in English Language and Mathematics at West African Senior School Certificate Examination

ERIC Educational Resources Information Center

Alade, O. M.; Kuku, O. O.; Osoba, A.

2017-01-01

The study investigated influence of some factors on the performance of selected West African Senior School Certificate Examination (WASSCE) candidates. It also examined the relationship between these factors and candidates' performance. Factors investigated include socio-economic background of the candidates (SEB), study hours (SH), attitude…

Transition Goals for Youth with Social, Emotional, and Behavioral Problems: Parent and Student Knowledge

ERIC Educational Resources Information Center

Harrison, Judith R.; State, Talida M.; Wills, Howard P.; Custer, Beth A.; Miller, Elaine

2017-01-01

Transition planning is a mandated component of individualized education plans (IEPs) designed to ensure successful transition to adult life for students with disabilities. Students with social, emotional, and behavioral (SEB) needs experience poor post-school outcomes, suggesting a need for more effective transition planning. This study evaluated…

Sunlight Helps Laboratory Get Ready for Y2K

Science.gov Websites

by the end of December to provide emergency electricity to the Site Entrance Building (SEB), which solar power if the supply of electricity from the local utility grid is interrupted. The solar generator failure disrupts electricity supplies. If a power failure should be protracted, a secondary propane backup

Medium-energy heavy-ion single-event-burnout imaging of power MOSFETs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musseau, O.; Torres, A.; Campbell, A.B.

The authors present the first experimental determination of the SEB sensitive area in a power MOSFET irradiated with a high-LET heavy-ion microbeam. They used a spectroscopy technique to perform coincident measurements of the charge collected in both source and drain junctions together, with a non-destructive technique (current limitation). The resulting charge collection images are related to the physical structure of the individual cells. These experimental data reveal the complex 3-dimensional behavior of a real structure, which can not easily be simulated using available tools. As the drain voltage is increased, the onset of burnout is reached, characterized by a suddenmore » change in the charge collection image. Hot spots are observed where the collected charge reaches its maximum value. Those spots, due to burnout triggering events, correspond to areas where the silicon is degraded through thermal effects along a single ion track. This direct observation of SEB sensitive areas as applications for, either device hardening, by modifying doping profiles or layout of the cells, or for code calibration and device simulation.« less

Simulation of CO2 Solubility in Polystyrene-b-Polybutadieneb-Polystyrene (SEBS) by artificial intelligence network (ANN) method

NASA Astrophysics Data System (ADS)

Sharudin, R. W.; AbdulBari Ali, S.; Zulkarnain, M.; Shukri, M. A.

2018-05-01

This study reports on the integration of Artificial Neural Network (ANNs) with experimental data in predicting the solubility of carbon dioxide (CO2) blowing agent in SEBS by generating highest possible value for Regression coefficient (R2). Basically, foaming of thermoplastic elastomer with CO2 is highly affected by the CO2 solubility. The ability of ANN in predicting interpolated data of CO2 solubility was investigated by comparing training results via different method of network training. Regards to the final prediction result for CO2 solubility by ANN, the prediction trend (output generate) was corroborated with the experimental results. The obtained result of different method of training showed the trend of output generated by Gradient Descent with Momentum & Adaptive LR (traingdx) required longer training time and required more accurate input to produce better output with final Regression Value of 0.88. However, it goes vice versa with Levenberg-Marquardt (trainlm) technique as it produced better output in quick detention time with final Regression Value of 0.91.

Production of cellulosic ethanol from sugarcane bagasse by steam explosion: Effect of extractives content, acid catalysis and different fermentation technologies.

PubMed

Neves, P V; Pitarelo, A P; Ramos, L P

2016-05-01

The production of cellulosic ethanol was carried out using samples of native (NCB) and ethanol-extracted (EECB) sugarcane bagasse. Autohydrolysis (AH) exhibited the best glucose recovery from both samples, compared to the use of both H3PO4 and H2SO4 catalysis at the same pretreatment time and temperature. All water-insoluble steam-exploded materials (SEB-WI) resulted in high glucose yields by enzymatic hydrolysis. SHF (separate hydrolysis and fermentation) gave ethanol yields higher than those obtained by SSF (simultaneous hydrolysis and fermentation) and pSSF (pre-hydrolysis followed by SSF). For instance, AH gave 25, 18 and 16 g L(-1) of ethanol by SHF, SSF and pSSF, respectively. However, when the total processing time was taken into account, pSSF provided the best overall ethanol volumetric productivity of 0.58 g L(-1) h(-1). Also, the removal of ethanol-extractable materials from cane bagasse had no influence on the cellulosic ethanol production of SEB-WI, regardless of the fermentation strategy used for conversion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Buckling Structured Stretchable Pseudocapacitor Yarn.

PubMed

Lee, Duck Weon; Lee, Jung Han; Min, Nam Ki; Jin, Joon-Hyung

2017-09-20

Cable-type stretchable electrochemical pseudocapacitors based on multi-walled carbon nanotube (MWCNT) sheets and two different metal oxide nanopowders (NP), i.e., MnO 2 and RuO 2 are developed using a newly-devised dry painting method to mechanically fix the NP to the elastic rubber-based MWCNT electrode substrate, resulting in a porous buckling structured pseudocapacitor yarn. Highly stretchable stylene-ethylene/butylene-stylene (SEBS) is used as the supporting elastomeric core for wrapping with the MWCNT sheets and the electroactive NP. The dry painting can successfully deposit NP on the soft SEBS surface, which is normally an unfavorable substrate for coating alien materials. The resulting yarn-type pseudocapacitor, composed of eight-layered MWCNT sheets, three-layered RuO 2 , and two-layered MnO 2 , showing a diameter of approximately 400 μm with a porous buckling structure, records a specific capacitance of 25 F g -1 . After being stretched by 200% in strain with no sacrifice of the porous buckling structure, the cable-type stretchable electrochemical pseudocapacitor yarn retains its electrical capacity, and is potentially applicable to energy storage devices for wearable electronics.

Electricity Breakdown Management for Sarawak Energy: Use of Condition-Based Equipment for Detection of Defective Insulator

NASA Astrophysics Data System (ADS)

Tan, J. K.; Abas, N.

2017-07-01

Managing electricity breakdown is vital since an outage causes economic losses for customers and the utility companies. However, electricity breakdown is unavoidable due to some internal or external factors beyond our control. Electricity breakdown on overhead lines tend occur more frequently because it is prone to external disturbances such as animal, overgrown vegetation and defective pole top accessories. In Sarawak Energy Berhad (SEB), majority of the network are composed of overhead lines and hence, is more prone to failure. Conventional method of equipment inspection and fault finding are not effective to quickly identify the root cause of failure. SEB has engaged the use of corona discharge camera as condition-based monitoring equipment to carry out condition based inspection on the line in order to diagnose the condition of the lines prior to failure. Experimental testing has been carried out to determine the correlation between the corona discharge count and the level of defect on line insulator. The result shall be tabulated and will be used as reference for future scanning and diagnostic on any defect on the lines.

Improved survival with an innovative approach to the treatment of severely burned patients: development of a burn treatment manual.

PubMed

Morisada, S; Nosaka, N; Tsukahara, K; Ugawa, T; Sato, K; Ujike, Y

2015-09-30

The management of severely burned patients remains a major issue worldwide as indicated by the high incidence of permanent debilitating complications and poor survival rates. In April 2012, the Advanced Emergency & Critical Care Medical Center of the Okayama University Hospital began implementing guidelines for severely burned patients, distributed as a standard burn treatment manual. The protocol, developed in-house, was validated by comparing the outcomes of patients with severe extensive burns (SEB) treated before and after implementation of these new guidelines at this institution. The patients included in this study had a burn index (BI) ≥30 or a prognostic burn index (PBI = BI + patient's age) ≥100. The survival rate of the patients with BI ≥30 was 65.2% with the traditional treatment and 100% with the new guidelines. Likewise, the survival rate of the patients with PBI ≥100 was 61.1% with the traditional treatment compared to 100% with the new guidelines. Together, these data demonstrate that the new treatment guidelines dramatically improved the treatment outcome and survival of SEB patients.

A school-based programme for tobacco and alcohol prevention in special education: effectiveness of the modified 'healthy school and drugs' intervention and moderation by school subtype.

PubMed

Turhan, Abdullah; Onrust, Simone A; Ten Klooster, Peter M; Pieterse, Marcel E

2017-03-01

To test the effectiveness of the Healthy School and Drugs (HSD) programme on tobacco and alcohol use in Dutch secondary special education (SE) schools, and whether this depends upon subtypes of SE schools and the level of implementation. In a quasi-experimental design with baseline and post-treatment follow-up, 363 students were allocated arbitrarily or depending on teacher motivation to either intervention condition (n = 205) or usual curriculum (n = 158). Thirteen secondary SE schools spread throughout the Netherlands. Participants were recruited during the autumn of 2013 from three school subtypes: SE for adolescents with intellectual/physical disabilities (SEI; n = 13), behavioural/emotional difficulties (SEB; n = 136) and learning disabilities/developmental disorders (SEL; n = 214). Self-reported life-time smoking prevalence and life-time drinking frequency as outcomes, and school subtype (SEL/SEB) and implementation fidelity (high/low) as moderators. No significant differences were found at follow-up in life-time smoking [odds ratio (OR) = 1.52; 95% confidence interval (CI) = 0.74-3.12] and drinking frequency (d = 0.01; 95% CI = -0.16 to 0.18). Interaction analyses revealed adverse effects in SEB students for alcohol use (d = 0.43; 95% CI = 0.16-0.69). Effect on tobacco refusal self-efficacy was moderated positively by implementation fidelity (d = 0.35; 95% CI = 0.07-0.63). The Healthy School and Drugs programme adapted for secondary special education in the Netherlands lacked clear evidence for effects on all outcomes. This pilot study suggests further that, within special education, substance use interventions may need to be targeted at school subtypes, as these may have harmful effects among students with behavioural difficulties. Finally, limited evidence was found that programme effectiveness may depend upon implementation fidelity. © 2016 Society for the Study of Addiction.

Detection of Staphylococcus aureus enterotoxins in sheep cheese and dairy desserts by multiplex PCR technique.

PubMed

Ertas, Nurhan; Gonulalan, Zafer; Yildirim, Yeliz; Kum, Erhan

2010-08-15

The aim of this study was to investigate the presence of Staphylococcus aureus (S. aureus) and staphylococcal enterotoxins (SEs) genes in sheep cheese and dairy dessert samples by multiplex PCR (mPCR) technique. A total of 150 samples were analyzed consisting of 50 dairy dessert samples and 100 sheep cheese. Coagulase positive staphylococci (CPS) were found in 86 (57.3%) out of 150 analyzed samples. S. aureus were isolated from 60 (60%), 26 (52%) of sheep cheese and from of dairy desserts, respectively. Five suspected colonies were tested from each sheep cheese and dairy dessert samples for phenotypic and genotypic characterizations. A total of 430 isolates from the 86 positive samples were investigated in this study. Eighty (18.6%) isolates were characterized as S. aureus. The enterotoxin genes (sea, seb, sec, sed) were found in 13 (3.02%) out of 80 isolates. From cheese isolates, sea, seb and sed were detected in 5 (1.6%), 2 (0.6%), 1 (0.3%), respectively. From dairy dessert isolates, sea, sec and sed were detected in 3 (2.3%), 1 (0.76%), 1 (0.76%), respectively. The presence of SEs was identified in 12 (2.8%) out of 80 isolates by using ELISA technique. It was determined that these SEs had a distribution of 7 (1.6%) SEA, 2 (0.46%) SEB, 1 (0.23%) SEC, and 2 (0.46%) SED. SEs were found in 7 (2.3%) cheese and 5 (3.8%) dairy dessert isolates. In conclusion, S.aureus and their SEs were found to be present in sheep cheese and dairy desserts in this study. It is emphasized that the presence of S. aureus and their SEs genes in sheep cheese and dairy desserts may be regarded as a potential risk for human health. Copyright 2010 Elsevier B.V. All rights reserved.

Uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model at multiple flux tower sites

USGS Publications Warehouse

Chen, Mingshi; Senay, Gabriel B.; Singh, Ramesh K.; Verdin, James P.

2016-01-01

Evapotranspiration (ET) is an important component of the water cycle – ET from the land surface returns approximately 60% of the global precipitation back to the atmosphere. ET also plays an important role in energy transport among the biosphere, atmosphere, and hydrosphere. Current regional to global and daily to annual ET estimation relies mainly on surface energy balance (SEB) ET models or statistical and empirical methods driven by remote sensing data and various climatological databases. These models have uncertainties due to inevitable input errors, poorly defined parameters, and inadequate model structures. The eddy covariance measurements on water, energy, and carbon fluxes at the AmeriFlux tower sites provide an opportunity to assess the ET modeling uncertainties. In this study, we focused on uncertainty analysis of the Operational Simplified Surface Energy Balance (SSEBop) model for ET estimation at multiple AmeriFlux tower sites with diverse land cover characteristics and climatic conditions. The 8-day composite 1-km MODerate resolution Imaging Spectroradiometer (MODIS) land surface temperature (LST) was used as input land surface temperature for the SSEBop algorithms. The other input data were taken from the AmeriFlux database. Results of statistical analysis indicated that the SSEBop model performed well in estimating ET with an R2 of 0.86 between estimated ET and eddy covariance measurements at 42 AmeriFlux tower sites during 2001–2007. It was encouraging to see that the best performance was observed for croplands, where R2 was 0.92 with a root mean square error of 13 mm/month. The uncertainties or random errors from input variables and parameters of the SSEBop model led to monthly ET estimates with relative errors less than 20% across multiple flux tower sites distributed across different biomes. This uncertainty of the SSEBop model lies within the error range of other SEB models, suggesting systematic error or bias of the SSEBop model is within the normal range. This finding implies that the simplified parameterization of the SSEBop model did not significantly affect the accuracy of the ET estimate while increasing the ease of model setup for operational applications. The sensitivity analysis indicated that the SSEBop model is most sensitive to input variables, land surface temperature (LST) and reference ET (ETo); and parameters, differential temperature (dT), and maximum ET scalar (Kmax), particularly during the non-growing season and in dry areas. In summary, the uncertainty assessment verifies that the SSEBop model is a reliable and robust method for large-area ET estimation. The SSEBop model estimates can be further improved by reducing errors in two input variables (ETo and LST) and two key parameters (Kmax and dT).

The use of chitosan-dextran gel shows anti-inflammatory, antibiofilm, and antiproliferative properties in fibroblast cell culture.

PubMed

Paramasivan, Sathish; Jones, Damien; Baker, Leonie; Hanton, Lyall; Robinson, Simon; Wormald, Peter J; Tan, Lorwai

2014-01-01

Chitosan-dextran gel has been used as an antihemostatic agent and antiadhesive agent after endoscopic sinus surgery. Because Staphylococcus aureus biofilms have been implicated in recalcitrant chronic rhinosinusitis, this study aimed to further investigate the (i) anti-inflammatory, (ii) bacterial biofilm inhibition, (iii) antiproliferative effects, and (iv) wound-healing properties of chitosan and chitosan-dextran gel. Fibroblasts were isolated from human nasal tissue and were used to determine the effects of chitosan and chitosan-dextran gel on (i) cell proliferation, (ii) wound healing, (iii) inflammation in fibroblast cultures challenged with superantigens S. aureus enterotoxin B (SEB) and toxic shock syndrome toxin (TSST), and (iv) on S. aureus biofilms. Chitosan was highly effective at reducing IL-8 expression after TSST and SEB challenge. Chitosan was also effective at reducing IL-8 expression of nonchallenged fibroblasts showing its anti-inflammatory effects on fibroblasts in a diseased state. Chitosan-dextran gel showed strong antibiofilm properties at 50% (v/v) concentration in vitro. Dextran, on its own, showed antibiofilm properties at 1.25% (w/v) concentration. Chitosan, on its own, reduced proliferation of fibroblasts to 82% of control proliferation and chitosan-dextran gel reduced proliferation of the fibroblasts to 0.04% of control proliferation. Relative to the no treatment controls, chitosan-dextran gel significantly delayed the wound-healing rate over the first 48 hours of the experiment. Chitosan-dextran gel reduced fibroblast proliferation and wound-healing time, showing a possible mechanism of reducing adhesions in the postsurgical period. Chitosan reduced IL-8 levels, showing its anti-inflammatory properties. Chitosan-dextran gel and dextran treatment showed antibiofilm properties in our model.

Monitoring of "all-weather" evapotranspiration using optical and passive microwave remote sensing imagery over the River Source Region in Southwest China

NASA Astrophysics Data System (ADS)

Ma, Y.; Liu, S.

2017-12-01

Accurate estimation of surface evapotranspiration (ET) with high quality is one of the biggest obstacles for routine applications of remote sensing in eco-hydrological studies and water resource management at basin scale. However, many aspects urgently need to deeply research, such as the applicability of the ET models, the parameterization schemes optimization at the regional scale, the temporal upscaling, the selecting and developing of the spatiotemporal data fusion method and ground-based validation over heterogeneous land surfaces. This project is based on the theoretically robust surface energy balance system (SEBS) model, which the model mechanism need further investigation, including the applicability and the influencing factors, such as local environment, and heterogeneity of the landscape, for improving estimation accuracy. Due to technical and budget limitations, so far, optical remote sensing data is missing due to frequent cloud contamination and other poor atmospheric conditions in Southwest China. Here, a multi-source remote sensing data fusion method (ESTARFM: Enhanced Spatial and Temporal Adaptive Reflectance Fusion Model) method will be proposed through blending multi-source remote sensing data acquired by optical, and passive microwave remote sensors on board polar satellite platforms. The accurate "all-weather" ET estimation will be carried out for daily ET of the River Source Region in Southwest China, and then the remotely sensed ET results are overlapped with the footprint-weighted images of EC (eddy correlation) for ground-based validation.

The Relationships among Scientific Epistemic Beliefs, Conceptions of Learning Science, and Motivation of Learning Science: A Study of Taiwan High School Students

ERIC Educational Resources Information Center

Ho, Hsin-Ning Jessie; Liang, Jyh-Chong

2015-01-01

This study explores the relationships among Taiwanese high school students' scientific epistemic beliefs (SEBs), conceptions of learning science (COLS), and motivation of learning science. The questionnaire responses from 470 high school students in Taiwan were gathered for analysis to explain these relationships. The structural equation modeling…

Correlations among Five Demographic Variables and the Performance of Selected Jamaican 11th-Graders on Some Numerical Problems on Energy

ERIC Educational Resources Information Center

Emepue, Nicholas; Soyibo, Kola

2009-01-01

This study was designed to assess whether the level of performance of selected Jamaican 11th-grade physics students on some numerical problems on the energy concept was satisfactory and if there were significant differences in their performance linked to their gender, socioeconomic background (SEB), school location, English language and…

Phase structure and properties of poly(ethylene terephthalate)/polyethylene based on recycled materials

Treesearch

Yong Lei; Qinglin Wu; Craig M. Clemons; Weihong Guo

2009-01-01

Blends based on recycled high density polyethylene (R-HDPE) and recycled poly(ethylene terephthalate) (R-PET) were made through reactive extrusion. The effects of maleated polyethylene (PE-g-MA), triblock copolymer of styrene and ethylene/butylene (SEBS), and 4,40-methylenedi(phenyl isocyanate) (MDI) on blend properties were studied. The 2% PE-g-MA improved the...

Practical Considerations and Challenges Involved in Surfactant Enhanced Bioremediation of Oil

PubMed Central

Mohanty, Sagarika; Jasmine, Jublee

2013-01-01

Surfactant enhanced bioremediation (SEB) of oil is an approach adopted to overcome the bioavailability constraints encountered in biotransformation of nonaqueous phase liquid (NAPL) pollutants. Fuel oils contain n-alkanes and other aliphatic hydrocarbons, monoaromatics, and polynuclear aromatic hydrocarbons (PAHs). Although hydrocarbon degrading cultures are abundant in nature, complete biodegradation of oil is rarely achieved even under favorable environmental conditions due to the structural complexity of oil and culture specificities. Moreover, the interaction among cultures in a consortium, substrate interaction effects during the degradation and ability of specific cultures to alter the bioavailability of oil invariably affect the process. Although SEB has the potential to increase the degradation rate of oil and its constituents, there are numerous challenges in the successful application of this technology. Success is dependent on the choice of appropriate surfactant type and dose since the surfactant-hydrocarbon-microorganism interaction may be unique to each scenario. Surfactants not only enhance the uptake of constituents through micellar solubilization and emulsification but can also alter microbial cell surface characteristics. Moreover, hydrocarbons partitioned in micelles may not be readily bioavailable depending on the microorganism-surfactant interactions. Surfactant toxicity and inherent biodegradability of surfactants may pose additional challenges as discussed in this review. PMID:24350261

Exploring learners' beliefs about science reading and scientific epistemic beliefs, and their relations with science text understanding

NASA Astrophysics Data System (ADS)

Yang, Fang-Ying; Chang, Cheng-Chieh; Chen, Li-Ling; Chen, Yi-Chun

2016-07-01

The main purpose of this study was to explore learners' beliefs about science reading and scientific epistemic beliefs, and how these beliefs were associating with their understanding of science texts. About 400 10th graders were involved in the development and validation of the Beliefs about Science Reading Inventory (BSRI). To find the effects of reader beliefs and epistemic beliefs, a new group of 65 10th grade students whose reader and epistemic beliefs were assessed by the newly developed BSRI and an existing SEB questionnaire were invited to take part in a science reading task. Students' text understanding in terms of concept gain and text interpretations was collected and analyzed. By the correlation analysis, it was found that when students had stronger beliefs about meaning construction based on personal goals and experiences (i.e. transaction beliefs), they produced more thematic and critical interpretations of the content of the test article. The regression analysis suggested that students SEBs could predict concept gain as a result of reading. Moreover, among all beliefs examined in the study, transaction beliefs stood out as the best predictor of overall science-text understanding.

EFFECTS OF BIASES IN VIRIAL MASS ESTIMATION ON COSMIC SYNCHRONIZATION OF QUASAR ACCRETION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinhardt, Charles L.

2011-09-01

Recent work using virial mass estimates and the quasar mass-luminosity plane has yielded several new puzzles regarding quasar accretion, including a sub-Eddington boundary (SEB) on most quasar accretion, near-independence of the accretion rate from properties of the host galaxy, and a cosmic synchronization of accretion among black holes of a common mass. We consider how these puzzles might change if virial mass estimation turns out to have a systematic bias. As examples, we consider two recent claims of mass-dependent biases in Mg II masses. Under any such correction, the surprising cosmic synchronization of quasar accretion rates and independence from themore » host galaxy remain. The slope and location of the SEB are very sensitive to biases in virial mass estimation, and various mass calibrations appear to favor different possible physical explanations for feedback between the central black hole and its environment. The alternative mass estimators considered do not simply remove puzzling quasar behavior, but rather replace it with new puzzles that may be more difficult to solve than those using current virial mass estimators and the Shen et al. catalog.« less

Array biosensor: recent developments

NASA Astrophysics Data System (ADS)

Golden, Joel P.; Rowe-Taitt, Chris A.; Feldstein, Mark J.; Ligler, Frances S.

1999-05-01

A fluorescence-based immunosensor has been developed for simultaneous analyses of multiple samples for 1 to 6 different antigens. A patterned array of recognition antibodies immobilized on the surface of a planar waveguide is used to 'capture' analyte present in samples. Bound analyte is then quantified by means of fluorescent detector molecules. Upon excitation of the fluorescent label by a small diode laser, a CCD camera detects the pattern of fluorescent antigen:antibody complexes on the sensor surface. Image analysis software correlates the position of fluorescent signals with the identity of the analyte. A new design for a fluidics distribution system is shown, as well as results from assays for physiologically relevant concentrations of staphylococcal enterotoxin B (SEB), F1 antigen from Yersinia pestis, and D- dimer, a marker of sepsis and thrombotic disorders.

DoD Resource Augmentation for Civilian Consequence Management (DRACCM) Tool

DTIC Science & Technology

2015-07-01

staffing availabilities for the nine regions. Finally, we added options to view IDAC data that had included school closings, vaccinations , antivirals...there is enough critical medical resource at that hospital for a given day. An hospital icon coded yellow means that at least one critical medical...tularemia, Q fever , SEB, anthrax, plague (with contagion), VEE, botulism, brucellosis, glanders, smallpox (with contagion), influenza, cesium, sarin, VX

Prevalence and Characterization of Staphylococcus aureus Strains in the Pork Chain Supply in Chile.

PubMed

Velasco, Valeria; Vergara, José L; Bonilla, Ana M; Muñoz, Javier; Mallea, Alejandra; Vallejos, Diego; Quezada-Aguiluz, Mario; Campos, Jorge; Rojas-García, Pedro

2018-05-01

The detection of methicillin-resistant Staphylococcus aureus (MRSA) and other emerging strains in meat-producing animals and retail meat has increased the risk of contamination of food. The aim of this study was to determine the prevalence and characterize S. aureus strains isolated from the pork chain supply in Chile. A total of 487 samples were collected: 332 samples from pigs at farms and slaughterhouses (nasal, n = 155; skin, n = 177); 85 samples from carcasses at slaughterhouses; and 70 meat samples at supermarkets and retail stores. The isolation of S. aureus was carried out by selective enrichment and culture media. Biochemical testing (API ® Staph) and PCR (detection of the nuc and mecA genes) were used to confirm S. aureus and MRSA strains. The agglutination test was used to determine the protein PBP2'. Enterotoxins (SEA, SEB, SEC, SED) were determined by agglutination test and the se genes by PCR method. Oxacillin and cefoxitin susceptibility testing were carried out using the diffusion method. The overall prevalence of S. aureus in the pork meat supply was 33.9%. A higher prevalence was detected on carcasses (56.5%), in pigs sampled at farms (40.6%) than in pigs sampled at slaughterhouses (23.3%) and in nonpackaged retail meat (43.1%) than packaged retail meat (5.3%) (p ≤ 0.05). No significant differences (p > 0.05) were found between the prevalence in pigs (28.3%) and pork meat (32.9%) and between natural pig farming (33.3%) and conventional production (52.8%). The mecA gene and the protein PBP2' were not detected in S. aureus strains. Two S. aureus strains exhibited oxacillin and cefoxitin resistance, and one S. aureus strain was resistant to cefoxitin. One S. aureus strain isolated from a meat sample was positive for enterotoxin SEB. Although the mecA gene was not detected, oxacillin-resistant and seb-producing S. aureus strains were detected, which represent a risk in the pork chain supply.

Direct measurements of meltwater runoff on the Greenland ice sheet surface

NASA Astrophysics Data System (ADS)

Smith, Laurence C.; Yang, Kang; Pitcher, Lincoln H.; Overstreet, Brandon T.; Chu, Vena W.; Rennermalm, Åsa K.; Ryan, Jonathan C.; Cooper, Matthew G.; Gleason, Colin J.; Tedesco, Marco; Jeyaratnam, Jeyavinoth; van As, Dirk; van den Broeke, Michiel R.; van de Berg, Willem Jan; Noël, Brice; Langen, Peter L.; Cullather, Richard I.; Zhao, Bin; Willis, Michael J.; Hubbard, Alun; Box, Jason E.; Jenner, Brittany A.; Behar, Alberto E.

2017-12-01

Meltwater runoff from the Greenland ice sheet surface influences surface mass balance (SMB), ice dynamics, and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream fluvial catchment area. A first 72-h trial for a 63.1-km2 moulin-terminating internally drained catchment (IDC) on Greenland's midelevation (1,207–1,381 m above sea level) ablation zone is compared with melt and runoff simulations from HIRHAM5, MAR3.6, RACMO2.3, MERRA-2, and SEB climate/SMB models. Current models cannot reproduce peak discharges or timing of runoff entering moulins but are improved using synthetic unit hydrograph (SUH) theory. Retroactive SUH applications to two older field studies reproduce their findings, signifying that remotely sensed IDC area, shape, and supraglacial river length are useful for predicting delays in peak runoff delivery to moulins. Applying SUH to HIRHAM5, MAR3.6, and RACMO2.3 gridded melt products for 799 surrounding IDCs suggests their terminal moulins receive lower peak discharges, less diurnal variability, and asynchronous runoff timing relative to climate/SMB model output alone. Conversely, large IDCs produce high moulin discharges, even at high elevations where melt rates are low. During this particular field experiment, models overestimated runoff by +21 to +58%, linked to overestimated surface ablation and possible meltwater retention in bare, porous, low-density ice. Direct measurements of ice surface runoff will improve climate/SMB models, and incorporating remotely sensed IDCs will aid coupling of SMB with ice dynamics and subglacial systems.

Direct measurements of meltwater runoff on the Greenland ice sheet surface.

PubMed

Smith, Laurence C; Yang, Kang; Pitcher, Lincoln H; Overstreet, Brandon T; Chu, Vena W; Rennermalm, Åsa K; Ryan, Jonathan C; Cooper, Matthew G; Gleason, Colin J; Tedesco, Marco; Jeyaratnam, Jeyavinoth; van As, Dirk; van den Broeke, Michiel R; van de Berg, Willem Jan; Noël, Brice; Langen, Peter L; Cullather, Richard I; Zhao, Bin; Willis, Michael J; Hubbard, Alun; Box, Jason E; Jenner, Brittany A; Behar, Alberto E

2017-12-12

Meltwater runoff from the Greenland ice sheet surface influences surface mass balance (SMB), ice dynamics, and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream fluvial catchment area. A first 72-h trial for a 63.1-km 2 moulin-terminating internally drained catchment (IDC) on Greenland's midelevation (1,207-1,381 m above sea level) ablation zone is compared with melt and runoff simulations from HIRHAM5, MAR3.6, RACMO2.3, MERRA-2, and SEB climate/SMB models. Current models cannot reproduce peak discharges or timing of runoff entering moulins but are improved using synthetic unit hydrograph (SUH) theory. Retroactive SUH applications to two older field studies reproduce their findings, signifying that remotely sensed IDC area, shape, and supraglacial river length are useful for predicting delays in peak runoff delivery to moulins. Applying SUH to HIRHAM5, MAR3.6, and RACMO2.3 gridded melt products for 799 surrounding IDCs suggests their terminal moulins receive lower peak discharges, less diurnal variability, and asynchronous runoff timing relative to climate/SMB model output alone. Conversely, large IDCs produce high moulin discharges, even at high elevations where melt rates are low. During this particular field experiment, models overestimated runoff by +21 to +58%, linked to overestimated surface ablation and possible meltwater retention in bare, porous, low-density ice. Direct measurements of ice surface runoff will improve climate/SMB models, and incorporating remotely sensed IDCs will aid coupling of SMB with ice dynamics and subglacial systems. Copyright © 2017 the Author(s). Published by PNAS.

Direct measurements of meltwater runoff on the Greenland ice sheet surface

PubMed Central

Smith, Laurence C.; Yang, Kang; Pitcher, Lincoln H; Overstreet, Brandon T.; Chu, Vena W.; Rennermalm, Åsa K.; Ryan, Jonathan C.; Cooper, Matthew G.; Gleason, Colin J.; Tedesco, Marco; Jeyaratnam, Jeyavinoth; van As, Dirk; van den Broeke, Michiel R.; van de Berg, Willem Jan; Noël, Brice; Langen, Peter L.; Cullather, Richard I.; Zhao, Bin; Hubbard, Alun; Box, Jason E.; Jenner, Brittany A.; Behar, Alberto E.

2017-01-01

Meltwater runoff from the Greenland ice sheet surface influences surface mass balance (SMB), ice dynamics, and global sea level rise, but is estimated with climate models and thus difficult to validate. We present a way to measure ice surface runoff directly, from hourly in situ supraglacial river discharge measurements and simultaneous high-resolution satellite/drone remote sensing of upstream fluvial catchment area. A first 72-h trial for a 63.1-km2 moulin-terminating internally drained catchment (IDC) on Greenland’s midelevation (1,207–1,381 m above sea level) ablation zone is compared with melt and runoff simulations from HIRHAM5, MAR3.6, RACMO2.3, MERRA-2, and SEB climate/SMB models. Current models cannot reproduce peak discharges or timing of runoff entering moulins but are improved using synthetic unit hydrograph (SUH) theory. Retroactive SUH applications to two older field studies reproduce their findings, signifying that remotely sensed IDC area, shape, and supraglacial river length are useful for predicting delays in peak runoff delivery to moulins. Applying SUH to HIRHAM5, MAR3.6, and RACMO2.3 gridded melt products for 799 surrounding IDCs suggests their terminal moulins receive lower peak discharges, less diurnal variability, and asynchronous runoff timing relative to climate/SMB model output alone. Conversely, large IDCs produce high moulin discharges, even at high elevations where melt rates are low. During this particular field experiment, models overestimated runoff by +21 to +58%, linked to overestimated surface ablation and possible meltwater retention in bare, porous, low-density ice. Direct measurements of ice surface runoff will improve climate/SMB models, and incorporating remotely sensed IDCs will aid coupling of SMB with ice dynamics and subglacial systems. PMID:29208716

[Changes of platelet rheological behavior and the interventional effects of ulinastatin in rats with high-voltage electrical burns].

PubMed

Zhang, Q F; Li, Y; Feng, J K; Xu, Y F; Tu, L L

2017-12-20

Objective: To explore the influence of high-voltage electrical burns on the number of platelet aggregation, β-thromboglobulin (β-TG) and platelet factor 4 (PF-4) and the interventional effects of ulinastatin in rats with high-voltage electrical burns. Methods: A total of 240 Sprague-Dawley rats were divided into sham injury (SI) group, simple electrical burn (SEB) group, normal saline (NS) group, and ulinastatin (UTI) group according to the random number table, with 60 rats in each group. The electrical current was applied to the outside proximal part of left forelimb of rats and exited from the outside proximal part of right hind limb of rats. Rats in groups SEB, NS, and UTI were inflicted with high-voltage electrical burn wounds of 1 cm×1 cm at current entrances and exits, with the voltage regulator and experimental transformer. Rats in group SI were sham injured through connecting the same equipments without electricity. At 2 min post injury, rats in group NS were intraperitoneally injected with 2 mL/kg NS, and rats in group UTI were intraperitoneally injected with 2×10(4) U/kg UTI of 10 g/L. At 15 min before injury and 5 min, 1 h, 2 h, 4 h, 8 h post injury, 10 rats in each group were selected to collect 5-7 mL blood of heart respectively. Blood of 0.05 mL were collected to make fresh blood smear for observing the number of platelet aggregation, and serum were separated from the remaining blood to determine content of β-TG and PF-4 with enzyme-linked immunosorbent assay. Data were processed with analysis of factorial design of variance, student-Newman-Keuls test, Kruskal-Wallis H test, Wilcoxon rank sum test, and Bonferroni correction. Results: (1) At 15 min before injury, the numbers of platelet aggregation of rats were close among groups SI, SEB, NS and UTI (5.9±1.2, 5.8±1.2, 5.9±1.3, 5.9±1.1, respectively, with P values above 0.05). At 5 min, 1 h, 2 h, 4 h, 8 h post injury, the numbers of platelet aggregation of rats in group SEB were 57.2±16.3, 59.1±16.9, 60.8±20.6, 83.6±24.9, and 83.4±30.3, respectively, obviously more than those in group SI (6.0±1.3, 6.0±1.4, 5.9±1.4, 5.7±1.1, and 5.8±1.3, respectively, with P values below 0.001); the numbers of platelet aggregation of rats in group UTI were 29.6±7.4, 31.9±10.1, 35.0±14.2, 43.0±13.6, and 35.2±11.1, respectively, obviously more than those in group NS (58.3±16.1, 63.9±18.0, 60.8±17.7, 74.2±23.0, and 82.3±21.9, respectively, with P values below 0.001). There was no significantly statistical difference in the number of platelet aggregation of rats in group SI between each two time points within the same group (with P values above 0.05), but the number of platelet aggregation of rats in the other 3 groups at each time point post injury was significantly more than that of the same group at 15 min before injury (with P values below 0.001). (2) At 2, 4, and 8 h post injury, β-TG content of serum of rats in group SEB was significantly higher than that in group SI (with Z values from -3.780 to -3.477, P values below 0.05). At 5 min and 4 h post injury, β-TG content of serum of rats in group UTI was significantly lower than that in group NS (with Z values respectively -3.477 and -3.780, P values below 0.05). There was no significantly statistical difference in β-TG content of serum of rats in group SI at all time points of the same group ( χ (2)=0.130, P >0.05). At 2, 4, and 8 h post injury, β-TG content of serum of rats in group SEB was significantly higher than that of the same group at 15 min before injury (with Z values from -3.780 to -3.553, P values below 0.05). At 5 min, 1 h, and 4 h post injury, β-TG content of serum of rats in group NS was significantly higher than that of the same group at 15 min before injury (with Z values from -3.780 to -3.477, P values below 0.05). At 1 and 4 h post injury, β-TG content of serum of rats in group UTI was significantly higher than that of the same group at 15 min before injury (with Z values respectively -3.250 and -3.780, P values below 0.05). (3) At 2 and 8 h post injury, PF-4 content of serum of rats in group SEB was significantly higher than that in group SI (with P values below 0.05). At 2 h post injury, PF-4 content of serum of rats in group UTI was significantly higher than that in group NS ( P <0.05), and at 4 and 8 h post injury, PF-4 content of serum of rats in group UTI was significantly lower than that in group NS (with P values below 0.05). At all time points, PF-4 content of serum of rats in group SI was close (with P values above 0.05). At 2 and 8 h post injury, PF-4 content of serum of rats in group SEB was significantly higher than that of the same group at 15 min before injury (with P values below 0.05). At 1, 4, and 8 h post injury, PF-4 content of serum of rats in group NS was significantly higher than that of the same group at 15 min before injury (with P values below 0.05). There were significantly statistical differences in PF-4 content of serum of rats between all time points except for 5 min post injury and 15 min before injury (with P values below 0.05). Conclusions: Increasing number of platelet aggregation and abnormal secretion of β-TG and PF-4 of rats with high-voltage electrical burns can lead to microcirculation disturbance. UTI can alleviate microcirculation disturbance caused by high-voltage electrical burns by reducing the number of platelet aggregation and inhibiting secretion of β-TG and PF-4.

Fault-Tolerant Sequencer Using FPGA-Based Logic Designs for Space Applications

DTIC Science & Technology

2013-12-01

Prototype Board SBU single bit upset SDK software development kit SDRAM synchronous dynamic random-access memory SEB single-event burnout ...current VHDL VHSIC hardware description language VHSIC very-high-speed integrated circuits VLSI very-large- scale integration VQFP very...transient pulse, called a single-event transient (SET), or even cause permanent damage to the device in the form of a burnout or gate rupture. The SEE

Detection of Staphylococcus Aureus Enterotoxin A and B Genes with PCR-EIA and a Hand-Held Electrochemical Sensor

DTIC Science & Technology

2004-06-11

Streptococcus pneumoniae 33400 Enterobacter cloaceae 49141 S. pyogenes 19615 E. aerogenes m10822 Vibrio cholerae N16961 Enterococcus durans 6056 Yersinia...identified. Thus the sensitivity for both assays was 100%. Of the 56 samples that lacked sea or seb genes, two false positives ( Enterobacter aerogenes ...Comanonas, Enterobacter , Enterococcus, Escherichia, Francisella, Haemophilus, Klebsiella, Listeria, Moraxella, Neisseria, Proteus, Pseudomonas, Salmonella

Giove 2005 - 06: rapporto osservativo

NASA Astrophysics Data System (ADS)

Adamoli, G.

2007-08-01

Jupiter was observed and photographed at visible and near-IR wavelenghts. White spots at 59°S, a train of SSTCAWOs, oval BA turned orange, followed by a dark STB sector, relevant mid-SEB outbreak, big equatorial festoons and produced a massive EB, NEB extended beyond 20°N, NNTBs jetstream was active, a methan image showed a bright S. Polar Hood, a fainter N. one and a large and dark NTB

Eugenol reduces the expression of virulence-related exoproteins in Staphylococcus aureus.

PubMed

Qiu, Jiazhang; Feng, Haihua; Lu, Jing; Xiang, Hua; Wang, Dacheng; Dong, Jing; Wang, Jianfeng; Wang, Xiaoliang; Liu, Juxiong; Deng, Xuming

2010-09-01

Eugenol, an essential oil component in plants, has been demonstrated to possess activity against both gram-positive and gram-negative bacteria. This study examined the influence that subinhibitory concentrations of eugenol may have on the expression of the major exotoxins produced by Staphylococcus aureus. The results from a tumor necrosis factor (TNF) release assay and a hemolysin assay indicated that S. aureus cultured with graded subinhibitory concentrations of eugenol (16 to 128 microg/ml) dose dependently decreased the TNF-inducing and hemolytic activities of culture supernatants. Western blot analysis showed that eugenol significantly reduced the production of staphylococcal enterotoxin A (SEA), SEB, and toxic shock syndrome toxin 1 (the key exotoxins to induce TNF release), as well as the expression of alpha-hemolysin (the major hemolysin to cause hemolysis). In addition, this suppression was also evaluated at the transcriptional level via real-time reverse transcription (RT)-PCR analysis. The transcriptional analysis indicated that 128 microg/ml of eugenol remarkably repressed the transcription of the S. aureus sea, seb, tst, and hla genes. According to these results, eugenol has the potential to be rationally applied on food products as a novel food antimicrobial agent both to inhibit the growth of bacteria and to suppress the production of exotoxins by S. aureus.

Thermodynamic consideration and ground-state search of icosahedral boron subselenide B12(B1-xSex) 2 from a first-principles cluster expansion

NASA Astrophysics Data System (ADS)

Ektarawong, A.

2018-05-01

The phase stability of icosahedral boron subselenide B12(B1-xSex) 2 , where 0.5 ≤x ≤1 , is explored using a first-principles cluster expansion. The results shows that, instead of a continuous solid solution, B12(B1-xSex) 2 is thermodynamically stable as an individual line compound at the composition of B9.5Se . The ground-state configuration of B9.5Se is represented by a mixture of B12(Se-Se), B12(B-Se), and B12(Se-B) with a ratio of 1:1:1, where they form a periodic A B C A B C ⋯ stacking sequence of B12(Se-Se), B12(B-Se), and B12(Se-B) layers along the c axis of the hexagonal conventional unit cell. The structural and electronic properties of the ground-state B9.5Se are also derived and discussed. By comparing the derived ground-state properties of B9.5Se to the existing experimental data of boron subselenide B˜13Se , I proposed that the as-synthesized boron subselenide B˜13Se , as reported in the literature, has the actual composition of B9.5Se .

Validation of the Two-Parameter-Fracture Criterion for Various Crack Configurations Made of 2014-T6 (TL) Aluminum Alloy Using Finite Element Fracture Simulations

NASA Astrophysics Data System (ADS)

McQuilkin, Martin

The Two-Parameter- Fracture-Criterion (TPFC) was validated using an elastic-plastic two-dimensional (2D) finite-element code, ZIP2D, with the plane-strain- core concept. Fracture simulations were performed on three crack configurations: (1) middle-crack-tension, M(T), (2) single-edge- crack-tension, SE(T), and (3) single-edge crack-bend, SE(B), specimens. They were made of 2014-T6 (TL) aluminum alloy. Fracture test data from Thomas Orange work (NASA) were only available on M(T) specimens (one-half width, w = 1.5 to 6 in.) and they were all tested at cryogenic (-320 o F) temperature. All crack configurations were analysed over a very wide range of widths (w = 0.75 to 24 in.) and crack-length- to-width ratios ranged from 0.2 to 0.8. The TPFC was shown to fit the simulated fracture data fairly well (within 6.5%) for all crack configurations for net-section stresses less than the material proportional limit. For M(T) specimens, a simple approximation was shown to work well for net-section stresses greater than the proportional limit. Further study is needed for net-section stresses greater than the proportional limit for the SE(T) and SE(B) specimens.

Lung Cancer Worry and Home Screening for Radon and Secondhand Smoke in Renters.

PubMed

Hahn, Ellen J; Hooper, Marissa; Riker, Carol; Butler, Karen M; Rademacher, Kathy; Wiggins, Amanda; Rayens, Mary Kay

2017-01-01

Lung cancer is largely preventable by eliminating tobacco smoke and radon exposure. This exploratory study assessed the relationships of demographic factors, including having one or more smokers living in the household, and a) lung cancer worry and b) completion of home screening for radon and secondhand smoke (SHS) among renters. A convenience sample of renters (N = 47) received free test kits for radon and SHS as part of a larger study. Demographic factors, lung cancer worry, and completion of home testing were assessed at baseline. The sample was mostly Caucasian (68%), female (62%), and educated beyond high school (70%). The average age was 43 years (SD = 15), and roughly half lived with at least one smoker (49%). Gender, race/ethnicity, education, and whether they had smokers in the home accounted for 35% of the variability in lung cancer worry, F(4, 42) = 5.6, p = .001. Lung cancer worry was associated with lower level of education, b = 0.77; SE(b) = 0.32, and having at least one smoker living in the home, b = 0.71; SE(b) = 0.31. Renters tested their homes for radon and SHS whether they had smokers in the home or not. Constructing and delivering educational messages that target low-educated populations may promote radon testing and smoke-free homes.

Lung Cancer Worry and Home Screening for Radon and Secondhand Smoke in Renters

PubMed Central

Hahn, Ellen J.; Hooper, Marissa; Riker, Carol; Butler, Karen M.; Rademacher, Kathy; Wiggins, Amanda; Rayens, Mary Kay

2017-01-01

Lung cancer is largely preventable by eliminating tobacco smoke and radon exposure. This exploratory study assessed the relationships of demographic factors, including having one or more smokers living in the household, and a) lung cancer worry and b) completion of home screening for radon and secondhand smoke (SHS) among renters. A convenience sample of renters (N = 47) received free test kits for radon and SHS as part of a larger study. Demographic factors, lung cancer worry, and completion of home testing were assessed at baseline. The sample was mostly Caucasian (68%), female (62%), and educated beyond high school (70%). The average age was 43 years (SD = 15), and roughly half lived with at least one smoker (49%). Gender, race/ethnicity, education, and whether they had smokers in the home accounted for 35% of the variability in lung cancer worry, F(4, 42) = 5.6, p = .001. Lung cancer worry was associated with lower level of education, b = 0.77; SE(b) = 0.32, and having at least one smoker living in the home, b = 0.71; SE(b) = 0.31. Renters tested their homes for radon and SHS whether they had smokers in the home or not. Constructing and delivering educational messages that target low-educated populations may promote radon testing and smoke-free homes. PMID:29135198

Preparation, characterisation and study of in vitro biologically active azamacrocyclic Cu(II) dicarboxylate complexes

NASA Astrophysics Data System (ADS)

Antonijević-Nikolić, Mirjana; Antić-Stanković, Jelena; Tanasković, Sladjana B.; Korabik, Maria J.; Gojgić-Cvijović, Gordana; Vučković, Gordana

2013-12-01

New cationic Cu(II) complexes with N, N‧, N″, N″‧-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane (tpmc) and aliphatic dicarboxylic acids: pentanedioic (glutaric acid = glutH2), hexanedioic acid (adipic acid = adipH2) and decanedioic acid (sebacic acid = sebH2) of general formula [Cu4(L)(tpmc)2](ClO4)6·xH2O, L = glut, x = 2; L = adip, x = 7; L = seb, x = 6 were isolated. Their composition and charges are proposed based on elemental analyses and molar conductivity measurements. By the comparison of their UV-Vis, reflectance, FTIR and EPR spectral data, CV and SQUID magnetic measurements, with those for the complex with butanedioic acid (succinic acid = succH2) of known molecular structure and analysis of LC/MS spectra, geometry with two [Cu2tpmc]4+ units bridged by dicarboxylate dianion engaging all oxygens is proposed. Within units, Cu(II) ions are also bridged with N portion of cyclam ring. All four complexes were screened to in vitro antimicrobial and cytotoxic activity along with free primary and secondary ligands, Cu(II) salt and solvent controls. Detected antibacterial and cytotoxic activity for the complexes was enhanced in most cases than the corresponding controls.

Highly Stretchable and Conductive Superhydrophobic Coating for Flexible Electronics.

PubMed

Su, Xiaojing; Li, Hongqiang; Lai, Xuejun; Chen, Zhonghua; Zeng, Xingrong

2018-03-28

Superhydrophobic materials integrating stretchability with conductivity have huge potential in the emerging application horizons such as wearable electronic sensors, flexible power storage apparatus, and corrosion-resistant circuits. Herein, a facile spraying method is reported to fabricate a durable superhydrophobic coating with excellent stretchable and electrical performance by combing 1-octadecanethiol-modified silver nanoparticles (M-AgNPs) with polystyrene- b-poly(ethylene- co-butylene)- b-polystyrene (SEBS) on a prestretched natural rubber (NR) substrate. The embedding of M-AgNPs in elastic SEBS matrix and relaxation of prestretched NR substrate construct hierarchical rough architecture and endow the coating with dense charge-transport pathways. The fabricated coating exhibits superhydrophobicity with water contact angle larger than 160° and a high conductivity with resistance of about 10 Ω. The coating not only maintains superhydrophobicity at low/high stretch ratio for the newly generated small/large protuberances but also responds to stretching and bending with good sensitivity, broad sensing range, and stable response cycles. Moreover, the coating exhibits excellent durability to heat and strong acid/alkali and mechanical forces including droplet impact, kneading, torsion, and repetitive stretching-relaxation. The findings conceivably stand out as a new tool to fabricate multifunctional superhydrophobic materials with excellent stretchability and conductivity for flexible electronics under wet or corrosive environments.

MAIT cells launch a rapid, robust and distinct hyperinflammatory response to bacterial superantigens and quickly acquire an anergic phenotype that impedes their cognate antimicrobial function: Defining a novel mechanism of superantigen-induced immunopathology and immunosuppression

PubMed Central

Shaler, Christopher R.; Choi, Joshua; Rudak, Patrick T.; Memarnejadian, Arash; Szabo, Peter A.; Tun-Abraham, Mauro E.; Rossjohn, Jamie; Corbett, Alexandra J.; McCluskey, James; McCormick, John K.; Lantz, Olivier; Hernandez-Alejandro, Roberto; Haeryfar, S.M. Mansour

2017-01-01

Superantigens (SAgs) are potent exotoxins secreted by Staphylococcus aureus and Streptococcus pyogenes. They target a large fraction of T cell pools to set in motion a “cytokine storm” with severe and sometimes life-threatening consequences typically encountered in toxic shock syndrome (TSS). Given the rapidity with which TSS develops, designing timely and truly targeted therapies for this syndrome requires identification of key mediators of the cytokine storm’s initial wave. Equally important, early host responses to SAgs can be accompanied or followed by a state of immunosuppression, which in turn jeopardizes the host’s ability to combat and clear infections. Unlike in mouse models, the mechanisms underlying SAg-associated immunosuppression in humans are ill-defined. In this work, we have identified a population of innate-like T cells, called mucosa-associated invariant T (MAIT) cells, as the most powerful source of pro-inflammatory cytokines after exposure to SAgs. We have utilized primary human peripheral blood and hepatic mononuclear cells, mouse MAIT hybridoma lines, HLA-DR4-transgenic mice, MAIThighHLA-DR4+ bone marrow chimeras, and humanized NOD-scid IL-2Rγnull mice to demonstrate for the first time that: i) mouse and human MAIT cells are hyperresponsive to SAgs, typified by staphylococcal enterotoxin B (SEB); ii) the human MAIT cell response to SEB is rapid and far greater in magnitude than that launched by unfractionated conventional T, invariant natural killer T (iNKT) or γδ T cells, and is characterized by production of interferon (IFN)-γ, tumor necrosis factor (TNF)-α and interleukin (IL)-2, but not IL-17A; iii) high-affinity MHC class II interaction with SAgs, but not MHC-related protein 1 (MR1) participation, is required for MAIT cell activation; iv) MAIT cell responses to SEB can occur in a T cell receptor (TCR) Vβ–specific manner but are largely contributed by IL-12 and IL-18; v) as MAIT cells are primed by SAgs, they also begin to develop a molecular signature consistent with exhaustion and failure to participate in antimicrobial defense. Accordingly, they upregulate lymphocyte-activation gene 3 (LAG-3), T cell immunoglobulin and mucin-3 (TIM-3), and/or programmed cell death-1 (PD-1), and acquire an anergic phenotype that interferes with their cognate function against Klebsiella pneumoniae and Escherichia coli; vi) MAIT cell hyperactivation and anergy co-utilize a signaling pathway that is governed by p38 and MEK1/2. Collectively, our findings demonstrate a pathogenic, rather than protective, role for MAIT cells during infection. Furthermore, we propose a novel mechanism of SAg-associated immunosuppression in humans. MAIT cells may therefore provide an attractive therapeutic target for the management of both early and late phases of severe SAg-mediated illnesses. PMID:28632753

Agents Within our Midst

DTIC Science & Technology

2012-03-14

agents; and the development of bio -monitoring protocols for civilian and service personnel during a chemical attack. These efforts have resulted in greater...produced by staphylococcal bacteria that is and is classified as a CDC select agent which has the potential to be used as a biological weapon .1...NMR chemical shift perturbation titrations with Fab (fragment, antigen binding regions) domains of 20B1, 14G8, and 6D3 using deuterated (2H) SEB

Preparation and Characterization of High Temperature Superconductor Film Surfaces

DTIC Science & Technology

1993-10-27

Lanthanum Strontium Copper Oxide (LSCO) was also tested as a normal metal overlayer because of its compatibility with the high deposition temperature for...fabricate YBCO/ISCO SEB junctions using a variety of step heights (110 nm - 330 nm) on Neodymium Gallate (NGO) substrates. NGO was chosen as a...substrate because of its excellent lattice match to YBCO and its lack of crystal twinning Twinning had been a drawback of Lanthanum Aluminate (LAO)- L

Tower-scale performance of four observation-based evapotranspiration algorithms within the WACMOS-ET project

NASA Astrophysics Data System (ADS)

Michel, Dominik; Miralles, Diego; Jimenez, Carlos; Ershadi, Ali; McCabe, Matthew F.; Hirschi, Martin; Seneviratne, Sonia I.; Jung, Martin; Wood, Eric F.; (Bob) Su, Z.; Timmermans, Joris; Chen, Xuelong; Fisher, Joshua B.; Mu, Quiaozen; Fernandez, Diego

2015-04-01

Research on climate variations and the development of predictive capabilities largely rely on globally available reference data series of the different components of the energy and water cycles. Several efforts have recently aimed at producing large-scale and long-term reference data sets of these components, e.g. based on in situ observations and remote sensing, in order to allow for diagnostic analyses of the drivers of temporal variations in the climate system. Evapotranspiration (ET) is an essential component of the energy and water cycle, which cannot be monitored directly on a global scale by remote sensing techniques. In recent years, several global multi-year ET data sets have been derived from remote sensing-based estimates, observation-driven land surface model simulations or atmospheric reanalyses. The LandFlux-EVAL initiative presented an ensemble-evaluation of these data sets over the time periods 1989-1995 and 1989-2005 (Mueller et al. 2013). The WACMOS-ET project (http://wacmoset.estellus.eu) started in the year 2012 and constitutes an ESA contribution to the GEWEX initiative LandFlux. It focuses on advancing the development of ET estimates at global, regional and tower scales. WACMOS-ET aims at developing a Reference Input Data Set exploiting European Earth Observations assets and deriving ET estimates produced by a set of four ET algorithms covering the period 2005-2007. The algorithms used are the SEBS (Su et al., 2002), Penman-Monteith from MODIS (Mu et al., 2011), the Priestley and Taylor JPL model (Fisher et al., 2008) and GLEAM (Miralles et al., 2011). The algorithms are run with Fluxnet tower observations, reanalysis data (ERA-Interim), and satellite forcings. They are cross-compared and validated against in-situ data. In this presentation the performance of the different ET algorithms with respect to different temporal resolutions, hydrological regimes, land cover types (including grassland, cropland, shrubland, vegetation mosaic, savanna, woody savanna, needleleaf forest, deciduous forest and mixed forest) are evaluated at the tower-scale in 24 pre-selected study regions on three continents (Europe, North America, and Australia). References: Fisher, J. B., Tu, K.P., and Baldocchi, D.D. Global estimates of the land-atmosphere water flux based on monthly AVHRR and ISLSCP-II data, validated at 16 FLUXNET sites, Remote Sens. Environ. 112, 901-919, 2008. Jiménez, C. et al. Global intercomparison of 12 land surface heat flux estimates. J. Geophys. Res. 116, D02102, 2011. 
 Miralles, D.G. et al. Global land-surface evaporation estimated from satellite-based observations. Hydrol. Earth Syst. Sci. 15, 453-469, 2011. 
 Mu, Q., Zhao, M. & Running, S.W. Improvements to a MODIS global terrestrial evapotranspiration algorithm. Remote Sens. Environ. 115, 1781-1800, 2011. 
 Mueller, B., Hirschi, M., Jimenez, C., Ciais, P., Dirmeyer, P. A., Dolman, A. J., Fisher, J. B., Jung, M., Ludwig, F., Maignan, F., Miralles, D. G., McCabe, M. F., Reichstein, M., Sheffield, J., Wang, K., Wood, E. F., Zhang, Y., and Seneviratne, S. I. (2013). Benchmark products for land evapotranspiration: LandFlux-EVAL multi-data set synthesis. Hydrology and Earth System Sciences, 17, 3707-3720. Mueller, B. et al. Benchmark products for land evapotranspiration: LandFlux-EVAL multi-dataset synthesis. Hydrol. Earth Syst. Sci. 17, 3707-3720, 2013. Su, Z. The Surface Energy Balance System (SEBS) for estimation of turbulent heat fluxes. Hydrol. Earth Syst. Sci. 6, 85-99, 2002.

Growth and condition of juvenile chum and pink salmon in the northeastern Bering Sea

NASA Astrophysics Data System (ADS)

Wechter, Melissa E.; Beckman, Brian R.; Andrews, Alexander G., III; Beaudreau, Anne H.; McPhee, Megan V.

2017-01-01

As the Arctic continues to warm, abundances of juvenile Pacific salmon (Oncorhynchus spp.) in the northern Bering Sea are expected to increase. However, information regarding the growth and condition of juvenile salmon in these waters is limited. The first objective of this study was to describe relationships between size, growth, and condition of juvenile chum (O. keta) and pink (O. gorbuscha) salmon and environmental conditions using data collected in the northeastern Bering Sea (NEBS) from 2003-2007 and 2009-2012. Salmon collected at stations with greater bottom depths and cooler sea-surface temperature (SST) were longer, reflecting their movement further offshore out of the warmer Alaska Coastal Water mass, as the season progressed. Energy density, after accounting for fish length, followed similar relationships with SST and bottom depth while greater condition (weight-length residuals) was associated with warm SST and shallower stations. We used insulin-like growth factor-1 (IGF-1) concentrations as an indicator of relative growth rate for fishes sampled in 2009-2012 and that found fish exhibited higher IGF-1 concentrations in 2010-2012 than in 2009, although these differences were not clearly attributable to environmental conditions. Our second objective was to compare size and condition of juvenile chum and pink salmon in the NEBS between warm and cool spring thermal regimes of the southeastern Bering Sea (SEBS). This comparison was based on a hypothesis informed by the strong role of sea-ice retreat in the spring for production dynamics in the SEBS and prevailing northward currents, suggesting that feeding conditions in the NEBS may be influenced by production in the SEBS. We found greater length (both species) and condition (pink salmon) in years with warm thermal regimes; however, both of these responses changed more rapidly with day of year in years with cool springs. Finally, we compared indicators of energy allocation between even and odd brood-year stocks of juvenile pink salmon, finding support for the idea that the even-year stock allocates more energy to storage, as opposed to growth, than does the odd-year stock. Over all, our results support the idea that sea-ice dynamics influence energy allocation and growth of juvenile salmon in the northern Bering Sea and provide a foundation for further understanding of how environmental conditions influence juvenile salmon at the northern edge of their range.

Modelling the climate and surface mass balance of polar ice sheets using RACMO2 - Part 2: Antarctica (1979-2016)

NASA Astrophysics Data System (ADS)

Melchior van Wessem, Jan; van de Berg, Willem Jan; Noël, Brice P. Y.; van Meijgaard, Erik; Amory, Charles; Birnbaum, Gerit; Jakobs, Constantijn L.; Krüger, Konstantin; Lenaerts, Jan T. M.; Lhermitte, Stef; Ligtenberg, Stefan R. M.; Medley, Brooke; Reijmer, Carleen H.; van Tricht, Kristof; Trusel, Luke D.; van Ulft, Lambertus H.; Wouters, Bert; Wuite, Jan; van den Broeke, Michiel R.

2018-04-01

We evaluate modelled Antarctic ice sheet (AIS) near-surface climate, surface mass balance (SMB) and surface energy balance (SEB) from the updated polar version of the regional atmospheric climate model, RACMO2 (1979-2016). The updated model, referred to as RACMO2.3p2, incorporates upper-air relaxation, a revised topography, tuned parameters in the cloud scheme to generate more precipitation towards the AIS interior and modified snow properties reducing drifting snow sublimation and increasing surface snowmelt. Comparisons of RACMO2 model output with several independent observational data show that the existing biases in AIS temperature, radiative fluxes and SMB components are further reduced with respect to the previous model version. The model-integrated annual average SMB for the ice sheet including ice shelves (minus the Antarctic Peninsula, AP) now amounts to 2229 Gt y-1, with an interannual variability of 109 Gt y-1. The largest improvement is found in modelled surface snowmelt, which now compares well with satellite and weather station observations. For the high-resolution ( ˜ 5.5 km) AP simulation, results remain comparable to earlier studies. The updated model provides a new, high-resolution data set of the contemporary near-surface climate and SMB of the AIS; this model version will be used for future climate scenario projections in a forthcoming study.

Multivariate Spectral Analysis to Extract Materials from Multispectral Data

DTIC Science & Technology

1993-09-01

Euclidean minimum distance and conventional Bayesian classifier suggest some fundamental instabilities. Two candidate sources are (1) inadequate...Coacete Water 2 TOTAL Cetu¢t1te 0 0 0 0 34 0 0 34 TZC10 0 0 0 0 0 26 0 26 hpem ~d I 0 0 to 0 0 0 0 60 Seb~ s 0 0 0 0 4 24 0 28 Mwal 0 0 0 0 33 29 0 62 Ihwid

Military Role in Countering Terrorist Use of Weapons of Mass Destruction

DTIC Science & Technology

1999-04-01

chemical and biological mobile point detection. “The M21 Remote Sensing Chemical Agent Alarm (RSCAAL) is an automatic scanning, passive infrared sensor...The M21 detects nerve and blister agent clouds based on changes in the background infrared spectra caused by the presence of the agent vapor.”15...required if greater than 3 years since last vaccine. VEE Yes Multiple vaccines required. VHF No Botulism Yes SEB No Ricin No Mycotoxin s No Source

PARENTAL REPORTS OF EARLY SOCIOEMOTIONAL AND BEHAVIORAL PROBLEMS: DOES THE FATHER'S VIEW MAKE A DIFFERENCE?

PubMed

Alakortes, Jaana; Fyrstén, Jenni; Bloigu, Risto; Carter, Alice S; Moilanen, Irma K; Ebeling, Hanna E

2017-05-01

Although both mothers and fathers are essential sources of information to address early socioemotional/behavioral (SEB) problems, there continues to be a dearth of studies considering both parental views. A sample of 208 toddlers (M age = 19.3 months) was recruited through public child health centers. Both parents of 172 toddlers (76 boys, 96 girls) completed the Child Behavior Checklist (CBCL) 1-5 (T.M. Achenbach & L.A. Rescorla, 2000; Finnish translation by F. Almqvist, ). Correspondence (intraclass correlation coefficients; ICCs) between the maternal and paternal CBCL ratings was good (.64) for the Internalizing and excellent (.76) for the Externalizing and Total Problems scores whereas ICCs varied from .45 for the Withdrawn to .76 for the Sleep Problems and Aggressive Behavior syndrome scores. Regarding discrepancies, mothers consistently reported higher CBCL scale scores than did fathers. Most significant differences between the parental ratings were found on the Aggressive Behavior syndrome, Externalizing, and Total Problems scales. Interparental rating discrepancies increased with elevations in the corresponding CBCL scale scores. Positive correlations were found between maternal, but not paternal, parenting stress and interparental rating discrepancies on the CBCL. The observed differences between maternal and paternal ratings highlight the importance of gathering reports from both parents when assessing early SEB problems. The findings are more profoundly discussed in the article. © 2017 Michigan Association for Infant Mental Health.

Development of an ELISA microarray assay for the sensitive and simultaneous detection of ten biodefense toxins.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jenko, Kathryn; Zhang, Yanfeng; Kostenko, Yulia

Plant and microbial toxins are considered bioterrorism threat agents because of their extreme toxicity and/or ease of availability. Additionally, some of these toxins are increasingly responsible for accidental food poisonings. The current study utilized an ELISA-based protein antibody microarray for the multiplexed detection of ten biothreat toxins, botulinum neurotoxins (BoNT) A, B, C, D, E, F, ricin, shiga toxins 1 and 2 (Stx), and staphylococcus enterotoxin B (SEB), in buffer and complex biological matrices. The multiplexed assay displayed a sensitivity of 1.3 pg/mL (BoNT/A, BoNT/B, SEB, Stx-1 and Stx-2), 3.3 pg/mL (BoNT/C, BoNT/E, BoNT/F) and 8.2 pg/mL (BoNT/D, ricin). Allmore » assays demonstrated high accuracy (75-120 percent recovery) and reproducibility (most coefficients of variation < 20%). Quantification curves for the ten toxins were also evaluated in clinical samples (serum, plasma, nasal fluid, saliva, stool, and urine) and environmental samples (apple juice, milk and baby food) with overall minimal matrix effects. The multiplex assays were highly specific, with little crossreactivity observed between the selected toxin antibodies. The results demonstrate a multiplex microarray that improves current immunoassay sensitivity for biological warfare agents in buffer, clinical, and environmental samples.« less

Synthesis of High-Speed Digital Systems.

DTIC Science & Technology

1985-11-08

1 (sub2 sub 16 2 (sub3 sub 16) 3 (sub4 sub 16) 4 (eub5 sub 16) 5 (sub6 sub 16) 6 ( sub7 sub 16) 7 (addi add 16) 8 (add2 add 16) 9 (add3 add 16) 10...seB uub5 J2 16 se5) 15 (se6 sub6 JI 16 soO) 18 (se7 sub7 J5 16 se7) 17 (aol addi Dl 16 aol) 18 (a921 add2 add7 18 a02) 19 (&922 add2 add5 16 a02) 20...de4l D4 add4 16 de4) 33 Wd942 D4 sub4 16 de4) 34 (de~i D5 sub7 16 de5) 35 (deS2 D5 add8 16 deS) 36 (jell Ji add7 16 jel) 37 (je12 JI D5 16 jel) 38 (je2

A microflow cytometer on a chip

NASA Astrophysics Data System (ADS)

Golden, Joel P.; Kim, Jason; Anderson, George P.; Hashemi, Nastaran; Howell, Peter J.; Ligler, Frances S.

2010-02-01

A rapid, automated, multi-analyte Microflow Cytometer is being developed as a portable, field-deployable sensor for onsite diagnosis of biothreat agent exposure and environmental monitoring. The technology relies on a unique method for ensheathing a sample stream in continuous flow past an interrogation region where optical fibers provide excitation and collect emission. This approach efficiently focuses particles in the interrogation region of the fluidic channel, avoids clogging and provides for subsequent separation of the core and sheath fluids in order to capture the target for confirmatory assays and recycling of the sheath fluid. Fluorescently coded microspheres provide the capability for highly multiplexed assays. Optical analysis at four different wavelengths identified six sets of the coded microspheres recognizing Escherichia coli, Listeria, and Salmonella as well as cholera toxin, staphylococcal enterotoxin B (SEB), and ricin, and assay results were compared with those of a commercial Luminex analysis system.

Microbial Pathogenesis and Host Defense.

DTIC Science & Technology

1998-03-01

and DS 168- 1 were identical to each other but distinct from E2073 8A and DS37-4; the deduced amino acid sequences differed at 17 of 145 residues and...radiolabeled protein and RNA that reached a plateau within 1 h. In contrast, release of LPS-associated fatty acids did not exceed 10%, did not become...analyzed the effects of different superantigens (SEA, SEB, TSST- 1 and ETA) in contrast to their mutants (exchange of one or more amino acid residues

Acoustic Microsensors III. Direct Detection of Staphylococcal Enterotoxin B Employing a Piezoelectric Crystal Immunosensor with a Flexible Carboxylated Dextran Matrix as the Biochemical Interface.

DTIC Science & Technology

1998-03-01

8217real time’ monitoring van biologische strijdmiddelen en aanverwante verbindingen. TNO- PML onderzoekt de mogelijkheden van een immunoreactie op een...toxine, dat voedselvergiftiging veroorzaakt, behoort tot de biologische strijdmid- delen. SEB werd door PG33 gekozen als teststof om de diverse...onderzoek zieh richten op de detectie van grote antigenen die tot de biologische strijdmiddelen behoren, zoals sommige virussen en bacteri- en. De

Feasibility study for the swaziland/mozambique interconector. Executive summary of the final report. Export trade information

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-11-01

This study, conducted by Black & Veatch, was funded by the U.S. Trade and Development Agency. The report, produced for the Ministry of National Resources, Energy and Environment (MNRE) of Swaziland, determines the least cost capacity expansion option to meet the future power demand and system reliability criteria of Swaziland, with particular emphasis on the propsoed Interconnector between Swaziland and Mozambique. Volume 1 contains the Executive Summary and is divided into the following sections: (1.0) Study Objectives; (2.0) Swaziland and its Economy; (3.0) The Power Sector Structure in Swaziland; (4.0) Electric Power Resources; (5.0) Past Demand Growth; (6.0) Load andmore » Energy Forecasts; (7.0) Need for Power; (8.0) Generation and Transmission Capacity Addition Option; (9.0) SEB Expansion Plan Scenario Development; (10.0) EDM Expansion Plan Development; (11.0) Cost Sharing of the Interconnector; (12.0) Interconnector Options and Environmental Evaluation; (13.0) Generation/Transmission Trade Offs; (14.0) EPC RFP and Draft Interconnection Agreement; (15.0) Transmission System Study; (16.0) Conclusions and Recommendations.« less

Immune system development during early childhood in tropical Latin America: evidence for the age-dependent down regulation of the innate immune response.

PubMed

Teran, Rommy; Mitre, Edward; Vaca, Maritza; Erazo, Silvia; Oviedo, Gisela; Hübner, Marc P; Chico, Martha E; Mattapallil, Joseph J; Bickle, Quentin; Rodrigues, Laura C; Cooper, Philip J

2011-03-01

The immune response that develops in early childhood underlies the development of inflammatory diseases such as asthma and there are few data from tropical Latin America (LA). This study investigated the effects of age on the development of immunity during the first 5 years of life by comparing innate and adaptive immune responses in Ecuadorian children aged 6-9 months, 22-26 months, and 48-60 months. Percentages of naïve CD4+ T cells declined with age while those of memory CD4(+) and CD8(+) T cells increased indicating active development of the immune system throughout the first five years. Young infants had greater innate immune responses to TLR agonists compared to older children while regulatory responses including SEB-induced IL-10 and percentages of FoxP3(+) T-regulatory cells decreased with age. Enhanced innate immunity in early life may be important for host defense against pathogens but may increase the risk of immunopathology. Copyright © 2010 Elsevier Inc. All rights reserved.

Estimating surface fluxes over middle and upper streams of the Heihe River Basin with ASTER imagery

NASA Astrophysics Data System (ADS)

Ma, W.; Ma, Y.; Hu, Z.; Su, B.; Wang, J.; Ishikawa, H.

2009-06-01

Surface fluxes are important boundary conditions for climatological modeling and the Asian monsoon system. Recent availability of high-resolution, multi-band imagery from the ASTER (Advanced Space-borne Thermal Emission and Reflection Radiometer) sensor has enabled us to estimate surface fluxes to bridge the gap between local scale flux measurements using micrometeorological instruments and regional scale land-atmosphere exchanges of water and heat fluxes that are fundamental for the understanding of the water cycle in the Asian monsoon system. A Surface Energy Balance System (SEBS) method based on ASTER data and field observations has been proposed and tested for deriving net radiation flux (Rn), soil heat flux (G0), sensible heat flux (H) and latent heat flux (λ E) over heterogeneous land surface in this paper. As a case study, the methodology was applied to the experimental area of the WATER (Watershed Allied Telemetry Experimental Research), located at the mid-to-upstream sections of the Heihe River, northwest China. The ASTER data of 3 May and 4 June in 2008 was used in this paper for the case of mid-to-upstream sections of the Heihe River Basin. To validate the proposed methodology, the ground-measured land surface heat fluxes (net radiation flux (Rn), soil heat flux (G0), sensible heat flux (H) and latent heat flux (λ E)) were compared to the ASTER derived values. The results show that the derived surface variables and land surface heat fluxes in different months over the study area are in good accordance with the land surface status. It is therefore concluded that the proposed methodology is successful for the retrieval of land surface heat fluxes using the ASTER data and filed observation over the study area.

Realization of daily evapotranspiration in arid ecosystems based on remote sensing techniques

NASA Astrophysics Data System (ADS)

Elhag, Mohamed; Bahrawi, Jarbou A.

2017-03-01

Daily evapotranspiration is a major component of water resources management plans. In arid ecosystems, the quest for an efficient water budget is always hard to achieve due to insufficient irrigational water and high evapotranspiration rates. Therefore, monitoring of daily evapotranspiration is a key practice for sustainable water resources management, especially in arid environments. Remote sensing techniques offered a great help to estimate the daily evapotranspiration on a regional scale. Existing open-source algorithms proved to estimate daily evapotranspiration comprehensively in arid environments. The only deficiency of these algorithms is the course scale of the used remote sensing data. Consequently, the adequate downscaling algorithm is a compulsory step to rationalize an effective water resources management plan. Daily evapotranspiration was estimated fairly well using an Advance Along-Track Scanner Radiometer (AATSR) in conjunction with (MEdium Resolution Imaging Spectrometer) MERIS data acquired in July 2013 with 1 km spatial resolution and 3 days of temporal resolution under a surface energy balance system (SEBS) model. Results were validated against reference evapotranspiration ground truth values using standardized Penman-Monteith method with R2 of 0.879. The findings of the current research successfully monitor turbulent heat fluxes values estimated from AATSR and MERIS data with a temporal resolution of 3 days only in conjunction with reliable meteorological data. Research verdicts are necessary inputs for a well-informed decision-making processes regarding sustainable water resource management.

Comparison of Extruder Systems for 3D Printer Filament Fabrication

NASA Astrophysics Data System (ADS)

Ramirez, Adriana

Additive Manufacturing (AM) has grown in popularity over the past thirty years, due to its versatility, short design to product cycle, and capability to fabricate complex geometries, which cannot otherwise be produced. There exist several platforms that are able to print objects composed of different materials, making this technology significant in different fields such as: automotive, aerospace, medical, electronics, amongst others. Though several types of AM technologies are available, the expiration of the patents on fused deposition modeling (FDM) in 2009 has led to a widespread use of this platform in academia and home use settings. Widespread use of FDM-type AM platforms has led to a demand to fabricate feedstock materials for this AM platform. Particularly, in the home do it yourself (DIY) community there has been a widespread interest for users to manufacture their own feedstock filament leading to a large growth in home-use extrusion systems. The low cost of these desktop-grade systems has also made them attractive to academics, but there has not been a widespread effort into determining the efficacy of these small scale extrusion systems as compared to industrial quality extruders which are typically used to manufacture feedstock for FDM platforms. The aim of this study was to compare two extrusion processes: 1) a desktop grade single-screw extruder; and 2) an industrial scale twin-screw extruder. In order to understand differences between their performance and quality of mixing, a rubberized blend of acrylonitrile butadiene styrene (ABS) mixed with styrene ethylene butylene styrene with a maleic anhydride graft (SEBS-g-MA) at different ratios was compounded on each extrusion system. Melt flow index, and mechanical properties were compared. In addition, a raster pattern sensitivity study was performed to evaluate the effect of the extruder system on 3D printed objects. Finally, scanning electron microscopy (SEM) was used to examine the fracture surfaces of spent tensile specimens.

Investigation of the Semicoa 2N7616 and 2N7425 and the Microsemi 2N7480 for Single-Event Gate Rupture and Single-Event Burnout

NASA Technical Reports Server (NTRS)

Scheick, Leif

2014-01-01

Single-event-effect test results for hi-rel total-dose-hardened power MOSFETs are presented in this report. The 2N7616 and the 2N7425 from Semicoa and the 2N7480 from International Rectifier were tested to NASA test condition standards and requirements. The 2N7480 performed well and the data agree with the manufacture's data. The 2N7616 and 2N7425 were entry parts from Semicoa using a new device architecture. Unfortunately, the device performed poorly and Semicoa is withdrawing power MOSFETs from it line due to these data. Vertical metal-oxide-semiconductor field-effect transistors (MOSFETs) are the most commonly used power transistor. MOSFETs are typically employed in power supplies and high current switching applications. Due to the inherent high electric fields in the device, power MOSFETs are sensitive to heavy ion irradiation and can fail catastrophically as a result of single-event gate rupture (SEGR) or single-event burnout (SEB). Manufacturers have designed radiation-hardened power MOSFETs for space applications. See [1] through [5] for more information. The objective of this effort was to investigate the SEGR and SEB responses of two power MOSFETs recently produced. These tests will serve as a limited verification of these parts. It is acknowledged that further testing on the respective parts may be needed for some mission profiles.

Effect of age and latent CMV infection on CD8+ CD56+ T cells (NKT-like) frequency and functionality.

PubMed

Hassouneh, Fakhri; Campos, Carmen; López-Sejas, Nelson; Alonso, Corona; Tarazona, Raquel; Solana, Rafael; Pera, Alejandra

2016-09-01

Changes in the T cell pool caused by CMV infection have been proposed to contribute to immunosenescence, but it has been postulated that CMV can also have some beneficial effects in young individuals improving the immune response to other pathogens. T cells expressing CD56 (NKT-like cells) are cytotoxic effector cells with a significant role in the immune response against cancer. We have studied how age and latent CMV infection affect the frequency of NKT-like cells (CD8+ CD56+ T cells) and their response to Staphylococcal Enterotoxin B (SEB) in the context of CMV and ageing. NKT-like cell percentage increases with the combination of both CMV and age. The response to SEB and the polyfunctional index of NKT-like cells also increase with age in CMV-seropositive individuals. In young individuals, CMV infection induces a shift on the polyfunctional profile of CD8+ CD56- T cells not observed on the NKT-like cells response. NKT-like cells expressing CD57 are expanded in CMV-seropositive individuals and are more polyfunctional than their CD57-  counterpart. In addition CD57- NKT-like cells are more polyfunctional than CD8+ CD56- CD57- T cells. The results support that the expansion of polyfunctional NKT-cells may have a beneficial effect on the immune response against pathogens. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Characterization of Toxin Genes and Antimicrobial Susceptibility of Staphylococcus aureus from Retail Raw Chicken Meat.

PubMed

Li, Suixia; Wang, Panpan; Zhao, Jialin; Zhou, Luhong; Zhang, Pengfei; Fu, Chengyu; Meng, Jianghong; Wang, Xin

2018-04-01

The aim of this study was to investigate the toxin gene profile and antimicrobial resistance of Staphylococcus aureus isolates from raw chicken in the People's Republic of China. In total, 289 S. aureus isolates were characterized by antimicrobial susceptibility testing, and genes encoding enterotoxins, exfoliative toxins, Panton-Valentine leukocidin, and toxic shock syndrome toxin were revealed by PCR. Overall, 46.0% of the isolates were positive for one or more toxin genes. A high proportion of toxin genes were pvl (26.6%), followed by sej (12.5%), sea (9.0%), seh (8.3%), seb (6.9%), sec (6.9%), sed (4.8%), sei (3.1%), and see (2.4%). None of the isolates harbored seg, tsst-1, or exfoliative toxin genes. In total, 29 toxin gene profiles were obtained, and pvl (10.7%) was the most frequent genotype, followed by sea (5.9%), seb (4.8%), and sej (4.2%). Furthermore, 99.7% of the strains were resistant to at least one of the tested antimicrobial agents, and 87.2% of them displayed multidrug resistance. Resistance was most frequently observed to trimethoprim-sulfamethoxazole and erythromycin (86.2% for each), followed by tetracycline (69.9%), amoxicillin-clavulanic acid (45.0%), and ampicillin (42.6%). None of the strains were resistant to vancomycin. This study indicates that S. aureus isolates from raw chicken harbored multiple toxin genes and exhibited multiple antimicrobial resistance, which represents a potential health hazard for consumers.

[Multiplex PCR strategy for the simultaneous identification of Staphylococcus aureus and detection of staphylococcal enterotoxins in isolates from food poisoning outbreaks].

PubMed

Brizzio, Aníbal A; Tedeschi, Fabián A; Zalazar, Fabián E

2013-01-01

Staphylococcal food poisoning is the most frequent type of food poisoning around the world. Staphylococcus aureus enterotoxins cause significant loss of water in the intestinal lumen, followed by vomiting and diarrhea. To report a fast, reliable and inexpensive strategy based on multiplex PCR for the simultaneous identification of S. aureus and detection of five classical S. aureus enterotoxin genes ( sea, seb, sec, sed, see ) in Staphylococcus spp. strains isolated from food poisoning outbreaks. We analyzed isolates from 12 food poisoning outbreaks occurred in Santa Fe province (Argentina). Isolation and phenotypic characterization were carried out by standard procedures. Genotypic analysis was performed by multiplex PCR, using primers for nuc , sea-see and 16S rRNA genes simultaneously. Of all the strains tested, 58% were found to carry toxigenic genes. Sea and seb toxins were found at the same percentage (29%) while sec, sed and see genes were found in a lower and identical proportion (14%). We did not find more than one different type of S. aureus enterotoxin in the isolates analyzed. The multiplex PCR strategy designed in this work has enabled us to identify strains of S. aureus and detect -at the same time- their enterotoxigenic ability. At present, our efforts are devoted to the detection of genes encoding enterotoxins other than the classical ones, in order to know their impact on staphylococcal food poisoning, as well as to investigate their relevance to our country's public health.

Morphological Evaluation of the Adhesive/Enamel interfaces of Two-step Self-etching Adhesives and Multimode One-bottle Self-etching Adhesives.

PubMed

Sato, Takaaki; Takagaki, Tomohiro; Matsui, Naoko; Hamba, Hidenori; Sadr, Alireza; Nikaido, Toru; Tagami, Junji

To evaluate the acid-base resistant zone (ABRZ) at the adhesive/enamel interface of self-etching adhesives with or without prior phosphoric acid etching. Four adhesives were used in 8 groups: Clearfil SE Bond (SEB), Optibond XTR (XTR), Scotchbond Universal Adhesive (SBU), and Clearfil BOND SE ONE (ONE) without prior phosphoric-acid etching, and each adhesive with phosphoric acid etching for 10 s (P-SEB, P-XTR, P-SBU and P-ONE, respectively). After application of self-etching adhesives on ground enamel surfaces of human teeth, a flowable composite was placed. For observation of the acid-base resistant zone (ABRZ), the bonded interface was exposed to demineralizing solution (pH 4.5) for 4.5 h, followed by 5% NaOCl with ultrasonication for 20 min. After the acid-base challenge, morphological attributes of the interface were observed using SEM. ABRZ formation was confirmed in all groups. The funnel-shaped erosion beneath the interface was present in SBU and ONE, where nearly 10 to 15 μm of enamel was dissolved. With phosphoric acid etching, the ABRZs were obviously thicker compared with no phosphoric acid etching. Enamel beneath the bonding interface was more susceptible to acid dissolution in SBU and ONE. In the case of the one-bottle self-etching adhesives and universal adhesives that intrinsically have higher pH values, enamel etching should be recommended to improve the interfacial quality.

Molecular Typing and Virulence Characteristic of Methicillin-Resistant Staphylococcus Aureus Isolates from Pediatric Patients in Bucaramanga, Colombia

PubMed Central

Machuca, Mayra Alejandra; Sosa, Luis Miguel; González, Clara Isabel

2013-01-01

Background Staphylococcus aureus is among the most common global nosocomial pathogens. The emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA) is a public health problem worldwide that causes nosocomial and community infections. The goals of this study were to establish the clonal complexes (CC) of the isolates of MRSA obtained from pediatric patients in a university hospital in Colombia and to investigate its molecular characteristics based on the virulence genes and the genes of staphylococcal toxins and adhesins. Methods A total of 53 MRSA isolates from pediatric patients with local or systemic infections were collected. The MRSA isolates were typed based on the SCCmec, MLST, spa and agr genes. The molecular characterization included the detection of Panton-Valentine Leukocidin, superantigenic and exfoliative toxins, and adhesin genes. The correlation between the molecular types identified and the profile of virulence factors was determined for all isolates. Results Four CC were identified, including CC8, CC5, CC80 and CC78. The ST8-MRSA-IVc-agrI was the predominant clone among the isolates, followed by the ST5-MRSA-I-agrII and ST5-MRSA-IVc-agrII clones. Twelve spa types were identified, of which t10796 and t10799 were new repeat sequences. The isolates were carriers of toxin genes, and hlg (100%), sek (92%) and pvl (88%) were the most frequent. Ten toxin gene profiles were observed, and the most frequent were seq-sek-hlg (22.6%), sek-hlg (22.6%), seb-seq-sek-hlg (18.9%) and seb-sek-hlg (15.1%). The adhesion genes were present in most of the MRSA isolates, including the following: clf-A (89%), clf-B (87%), fnb-A (83%) and ica (83%). The majority of the strains carried SCCmec-IVc and were identified as causing nosocomial infection. No significant association between a molecular type and the virulence factors was found. Conclusion Four major MRSA clone complexes were identified among the isolates. ST8-MRSA-IVc-agrI pvl+ (USA300-LV) was the most frequent, confirming the presence of community-associated MRSA in Colombian hospitals. PMID:24058415

[Curing mode of universal adhesives affects the bond strength of resin cements to dentin].

PubMed

Fu, Z R; Tian, F C; Zhang, L; Han, B; Wang, X Y

2017-02-18

To determine the effects of curing mode of one-step and two-step universal adhesives on the micro-tensile bond strength (μTBS) of different dual-cure resin cements to dentin. One-step universal adhesive Single Bond Universal (SBU), and two-step universal adhesive OptiBond Versa (VSA) were chosen as the subjects, one-step self-etching adhesive OptiBond All in One (AIO) and two-step self-etching adhesive Clearfil SE Bond (SEB) were control groups, and two dual-cure resin cements RelyX Ultimate (RLX) and Nexus 3 Universal (NX3) were used in this study. In this study, 80 extracted human molars were selected and the dentin surface was exposed using diamond saw. The teeth were divided into 16 groups according to the adhesives (AIO, SBU, SEB, VSA), cure modes of adhesives (light cure, non-light cure) and resin cements (RLX, NX3). The adhesives were applied on the dentin surface following the instruction and whether light cured or not, then the resin cements were applied on the adhesives with 1 mm thickness and light cured (650 mW/cm(2) for 20 s. A resin was built up (5 mm) on the cements and light cured layer by layer. After water storage for 24 h, the specimens were cut into resin-cement-dentin strips with a cross sectional area of 1 mm×1 mm and the μTBS was measured. Regarding one-step universal adhesive (SBU) light cured, the μTBS with RLX [(35.45±7.04) MPa] or NX3 [(26.84±10.39) MPa] were higher than SBU non-light cured with RLX [(17.93±8.93) MPa)] or NX3 [(10.07±5.89) MPa, P<0.001]. Compared with AIO, light-cured SBU combined with RLX presented higher μTBS than AIO group [(35.45±7.04) MPa vs. (24.86±8.42) MPa, P<0.05]. When SBU was not lighted, the μTBS was lower than AIO [(17.93±8.93) MPa vs. (22.28±7.57) MPa, P<0.05]. For two-step universal adhesive (VSA) and control adhesive (SEB), curing mode did not affect the μTBS when used with either RLX or NX3 (25.98-32.24 MPa, P>0.05). Curing mode of one-step universal adhesive may affect the μTBS between dual-cure resin cements and dentin, while for two-step universal adhesive, the curing mode and the type of resin cements did not influence the μTBS.

Scaling and Single Event Effects (SEE) Sensitivity

NASA Technical Reports Server (NTRS)

Oldham, Timothy R.

2003-01-01

This paper begins by discussing the potential for scaling down transistors and other components to fit more of them on chips in order to increasing computer processing speed. It also addresses technical challenges to further scaling. Components have been scaled down enough to allow single particles to have an effect, known as a Single Event Effect (SEE). This paper explores the relationship between scaling and the following SEEs: Single Event Upsets (SEU) on DRAMs and SRAMs, Latch-up, Snap-back, Single Event Burnout (SEB), Single Event Gate Rupture (SEGR), and Ion-induced soft breakdown (SBD).

Correnti atmosferiche su Giove

NASA Astrophysics Data System (ADS)

Adamoli, Gianluigi

2006-06-01

UAI observations are presented concerning the surveillance of Jupiter's atmospheric currents by means of digital images. General statistics are derived about the latitude and speed of individual spots and currents in the period 2000-04, compared with the Voyager wind profile. Attention is drawn to the wind shear present at distinct latitudes, namely on the South edge of the SEB, across the NTB and across the NEB. Especially interesting were the 2003 remnants of the disappearing NTB, which showed a motion intermediate between the NTC and the NTBs jet streams. Vorticity was derived in all cases.

Drought impacts and resilience on crops via evapotranspiration estimations

NASA Astrophysics Data System (ADS)

Timmermans, Joris; Asadollahi Dolatabad, Saeid

2015-04-01

Currently, the global needs for food and water is at a critical level. It has been estimated that 12.5 % of the global population suffers from malnutrition and 768 million people still do not have access to clean drinking water. This need is increasing because of population growth but also by climate change. Changes in precipitation patterns will result either in flooding or droughts. Consequently availability, usability and affordability of water is becoming challenge and efficient use of water and water management is becoming more important, particularly during severe drought events. Drought monitoring for agricultural purposes is very hard. While meteorological drought can accurately be monitored using precipitation only, estimating agricultural drought is more difficult. This is because agricultural drought is dependent on the meteorological drought, the impacts on the vegetation, and the resilience of the crops. As such not only precipitation estimates are required but also evapotranspiration at plant/plot scale. Evapotranspiration (ET) describes the amount of water evaporated from soil and vegetation. As 65% of precipitation is lost by ET, drought severity is highly linked with this variable. In drought research, the precise quantification of ET and its spatio-temporal variability is therefore essential. In this view, remote sensing based models to estimate ET, such as SEBAL and SEBS, are of high value. However the resolution of current evapotranspiration products are not good enough for monitoring the impact of the droughts on the specific crops. This limitation originates because plot scales are in general smaller than the resolution of the available satellite ET products. As such remote sensing estimates of evapotranspiration are always a combination of different land surface types and cannot be used for plant health and drought resilience studies. The goal of this research is therefore to enable adequate resolutions of daily evapotranspiration estimates for monitoring crop health during the severe drought events. The presentation will provide results of the investigation into Droughts using time series of coarse resolution daily evapotranspiration produced from the SEBS remote sensing model, on basis of MODIS data. The evapotranspiration will be converted into drought severity using the evapotranspiration deficit index (ETDI). Afterwards the disaggregation to plot scale will be investigated. This disaggregation will be performed as a weighted filtering on basis of crop-coefficient at high resolution. These growth stage of the vegeation (needed for the estimation of the crop coefficients) are estimated on basis of Normalized Difference Vegetation Index (NDVI) using Landsat 5,7 and 8 observations. The final result of the research provides good statistical information about drought resilience and crop health.

Time series evapotranspiration maps at a regional scale: A methodology, evaluation, and their use in water resources management

NASA Astrophysics Data System (ADS)

Gowda, P. H.

2016-12-01

Evapotranspiration (ET) is an important process in ecosystems' water budget and closely linked to its productivity. Therefore, regional scale daily time series ET maps developed at high and medium resolutions have large utility in studying the carbon-energy-water nexus and managing water resources. There are efforts to develop such datasets on a regional to global scale but often faced with the limitations of spatial-temporal resolution tradeoffs in satellite remote sensing technology. In this study, we developed frameworks for generating high and medium resolution daily ET maps from Landsat and MODIS (Moderate Resolution Imaging Spectroradiometer) data, respectively. For developing high resolution (30-m) daily time series ET maps with Landsat TM data, the series version of Two Source Energy Balance (TSEB) model was used to compute sensible and latent heat fluxes of soil and canopy separately. Landsat 5 (2000-2011) and Landsat 8 (2013-2014) imageries for row 28/35 and 27/36 covering central Oklahoma was used. MODIS data (2001-2014) covering Oklahoma and Texas Panhandle was used to develop medium resolution (250-m), time series daily ET maps with SEBS (Surface Energy Balance System) model. An extensive network of weather stations managed by Texas High Plains ET Network and Oklahoma Mesonet was used to generate spatially interpolated inputs of air temperature, relative humidity, wind speed, solar radiation, pressure, and reference ET. A linear interpolation sub-model was used to estimate the daily ET between the image acquisition days. Accuracy assessment of daily ET maps were done against eddy covariance data from two grassland sites at El Reno, OK. Statistical results indicated good performance by modeling frameworks developed for deriving time series ET maps. Results indicated that the proposed ET mapping framework is suitable for deriving daily time series ET maps at regional scale with Landsat and MODIS data.

Influence of holding temperature on the growth and survival of Salmonella spp. and Staphylococcus aureus and the production of staphylococcal enterotoxin in egg products.

PubMed

Yang, S E; Yu, R C; Chou, C C

2001-01-22

In this study, growth and survival of Salmonella spp. and Staphylococcus aureus in steamed egg and scrambled egg held at 5, 18, 22, 37, 55 and 60 degrees C are investigated. The production of staphylococcal enterotoxin in steamed egg is also examined. Results reveal that Salmonella spp. and Staph. aureus in the egg products multiply best at 37 degrees C, followed closely by 22 and 18 degrees C. Neither pathogen showed growth in the egg products held at 5 degrees C. Initial inoculation dose, holding temperature and holding time affected the population of both organisms found in the egg products. Staphylococcal enterotoxin A (SEA) and B (SEB) are detected only in the egg products held at 37 or 22 degrees C. After holding at 37 degrees C for 36 h, scrambled egg inoculated with ca. 5.0 log cfu/g Staph. aureus contains the highest levels of SEA (> 64 ng/g) and SEB (> 64 ng/g). Although Salmonella spp. and Staph. aureus grow better in steamed eggs than in scrambled eggs, production of staphylococcal enterotoxin, in general, was higher in scrambled eggs than in steamed eggs. On the other hand, a repaid destruction of the test organisms in steamed eggs held at 60 degrees C was observed. Holding the steamed eggs at 60 degrees C, Salmonella spp. and Staph. aureus with an initial population of ca. 5.9 and 5.6 log cfu/g, respectively, reduced to a non-detectable level in 1 h.

Heavy quark diffusion in strong magnetic fields at weak coupling and implications for elliptic flow

DOE PAGES

Fukushima, Kenji; Hattori, Koichi; Yee, Ho -Ung; ...

2016-04-20

In this paper, we compute the momentum diffusion coefficients of heavy quarks, κ ∥ and κ ⊥, in a strong magnetic field B along the directions parallel and perpendicular to B, respectively, at the leading order in QCD coupling constant α s. We consider a regime relevant for the relativistic heavy ion collisions, α seB << T 2 << eB, so that thermal excitations of light quarks are restricted to the lowest Landau level (LLL) states. In the vanishing light-quark mass limit, we find κ LO ⊥ ∝ α 2 sTeB in the leading order that arises from screened Coulombmore » scatterings with (1+1)-dimensional LLL quarks, while κ ∥ gets no contribution from the scatterings with LLL quarks due to kinematic restrictions. We show that the first nonzero leading order contributions to κ LO ∥ come from the two separate effects: 1) the screened Coulomb scatterings with thermal gluons, and 2) a finite light-quark mass m q. The former leads to κ LO,gluon ∥ ∝ α 2 sT 3 and the latter to κ LO,massive ∥ ∝ α s(α seB) 1/2m 2 q. Based on our results, we propose a new scenario for the large value of heavy-quark elliptic flow observed in RHIC and LHC. Namely, when κ ⊥ >> κ ∥, an anisotropy in drag forces gives rise to a sizable amount of the heavy-quark elliptic flow even if heavy quarks do not fully belong to an ellipsoidally expanding background fluid.« less

Heavy quark diffusion in strong magnetic fields at weak coupling and implications for elliptic flow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fukushima, Kenji; Hattori, Koichi; Yee, Ho -Ung

In this paper, we compute the momentum diffusion coefficients of heavy quarks, κ ∥ and κ ⊥, in a strong magnetic field B along the directions parallel and perpendicular to B, respectively, at the leading order in QCD coupling constant α s. We consider a regime relevant for the relativistic heavy ion collisions, α seB << T 2 << eB, so that thermal excitations of light quarks are restricted to the lowest Landau level (LLL) states. In the vanishing light-quark mass limit, we find κ LO ⊥ ∝ α 2 sTeB in the leading order that arises from screened Coulombmore » scatterings with (1+1)-dimensional LLL quarks, while κ ∥ gets no contribution from the scatterings with LLL quarks due to kinematic restrictions. We show that the first nonzero leading order contributions to κ LO ∥ come from the two separate effects: 1) the screened Coulomb scatterings with thermal gluons, and 2) a finite light-quark mass m q. The former leads to κ LO,gluon ∥ ∝ α 2 sT 3 and the latter to κ LO,massive ∥ ∝ α s(α seB) 1/2m 2 q. Based on our results, we propose a new scenario for the large value of heavy-quark elliptic flow observed in RHIC and LHC. Namely, when κ ⊥ >> κ ∥, an anisotropy in drag forces gives rise to a sizable amount of the heavy-quark elliptic flow even if heavy quarks do not fully belong to an ellipsoidally expanding background fluid.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

McKallip, Robert J., E-mail: mckallip_r@mercer.ed; Lombard, Catherine; Sun Jingping

Extracts from plants containing plumbagin (PLB) continue to be used as a treatment of a number of chronic immunologically-based diseases. However, most of these claims are supported only by anecdotal evidence with few scientific reports describing the mechanism of action or the efficacy of plumbagin in the suppression of the immune response. In the current study, we tested the hypothesis that plumbagin-induced suppression of the immune response was mediated through the induction of apoptosis. Splenocytes from C57BL/6 mice cultured in the presence of 0.5 {mu}M or greater concentrations of PLB significantly reduced proliferative responses to mitogens, including anti-CD3 mAbs, concanavalinmore » A (Con A), lipopolysaccharide (LPS) and staphylococcal enterotoxin B (SEB) in vitro. Exposure of naive and activated splenocytes to PLB led to a significant increase in the levels of apoptosis. In addition, PLB treatment led to a significant increase in the levels of reactive oxygen species (ROS) in naive and activated splenocytes. Furthermore, treatment with the ROS scavenger, N-acetylcysteine (NAC), prevented PLB-induced apoptosis, suggesting a role of ROS in PLB-induced apoptosis. PLB-induced apoptosis led to ROS-mediated activation of both the extrinsic and intrinsic apoptotic pathways. In addition, plumbagin led to increased expression of Fas. Finally, treatment of mice with PLB (5 mg/kg) led to thymic and splenic atrophy as well as a significant suppression of the response to SEB and dinitroflourobenzene (DNFB) in vivo. Together, these results suggest that plumbagin has significant immunosuppressive properties which are mediated by generation of ROS, upregulation of Fas, and the induction of apoptosis.« less

Structure-Based Design and Synthesis of a Small Molecule that Exhibits Anti-inflammatory Activity by Inhibition of MyD88-mediated Signaling to Bacterial Toxin Exposure.

PubMed

Alam, Shahabuddin; Javor, Sacha; Degardin, Melissa; Ajami, Dariush; Rebek, Mitra; Kissner, Teri L; Waag, David M; Rebek, Julius; Saikh, Kamal U

2015-08-01

Both Gram-positive and Gram-negative pathogens or pathogen-derived components, such as staphylococcal enterotoxins (SEs) and endotoxin (LPS) exposure, activate MyD88-mediated pro-inflammatory cellular immunity for host defense. However, dysregulated MyD88-mediated signaling triggers exaggerated immune response that often leads to toxic shock and death. Previously, we reported a small molecule compound 1 mimicking BB-loop structure of MyD88 was capable of inhibiting pro-inflammatory response to SEB exposure in mice. In this study, we designed a dimeric structure compound 4210 covalently linked with compound 1 by a non-polar cyclohexane linker which strongly inhibited the production of pro-inflammatory cytokines in human primary cells to SEB (IC50 1-50 μm) or LPS extracted from Francisella tularensis, Escherichia coli, or Burkholderia mallei (IC50 10-200 μm). Consistent with cytokine inhibition, in a ligand-induced cell-based reporter assay, compound 4210 inhibited Burkholderia mallei or LPS-induced MyD88-mediated NF-kB-dependent expression of reporter activity (IC50 10-30 μm). Furthermore, results from a newly expressed MyD88 revealed that 4210 inhibited MyD88 dimer formation which is critical for pro-inflammatory signaling. Importantly, a single administration of compound 4210 in mice showed complete protection from lethal toxin challenge. Collectively, these results demonstrated that compound 4210 inhibits toxin-induced inflated pro-inflammatory immune signaling, thus displays a potential bacterial toxin therapeutic. © 2014 John Wiley & Sons A/S.

Detection of Staphylococcus aureus enterotoxigenic strains in bovine raw milk by reversed passive latex agglutination and multiplex polymerase chain reaction.

PubMed

Mansour, Asmaa Samy; Wagih, Gad El-Said; Morgan, Sabry D; Elhariri, Mahmoud; El-Shabrawy, Mona A; Abuelnaga, Azza S M; Elgabry, E A

2017-08-01

This review gives an outline of the assessment of enterotoxigenic Staphylococcus aureus tainting levels in raw milk from different sources in Egypt and characterization of enterotoxigenic strains utilizing a technique in light of PCR to identify genes coding for the production of staphylococcal enterotoxin (SE). The obtained data were compared with results from the application of the reversed passive latex. Multiplex PCR and reversed passive latex agglutination (RPLA) were used. A total of 141 samples of raw milk (cow's milk=33, buffalo's milk=58, and bulk tank milk=50) were investigated for S. aureus contamination and tested for enterotoxin genes presence and toxin production. S. aureus was detected in 23 (16.3%) samples phenotypically and genotypically by amplification of nuc gene. The S. aureus isolates were investigated for SEs genes ( sea to see ) by multiplex PCR and the toxin production by these isolates was screened by RPLA. SEs genes were detected in six isolates (26.1%) molecularly; see was the most observed gene where detected in all isolates, two isolates harbored seb , and two isolates harbored sec . According to RPLA, three isolates produced SEB and SEC. The study revealed the widespread of S. aureus strains caring genes coding for toxins. The real significance of the presence of these strains or its toxins in raw milk and their possible impact a potential hazard for staphylococcal food poisoning by raw milk consumption. Therefore, detection of enterotoxigenic S. aureus strains in raw milk is necessary for consumer safety.

From placement to prison revisited: Do mental health services disrupt the delinquency pipeline among Latino, African American and Caucasian youth in the child welfare system?

PubMed

Garcia, Antonio R; Greeson, Johanna K P; Kim, Minseop; Thompson, Allison; DeNard, Christina

2015-12-01

Racial and ethnic disparities in delinquency among child welfare-involved youth are well documented. However, less is known about the mechanisms through which these disparities occur. This study explores the extent to which sets of variables predict the occurrence of juvenile delinquency and whether race/ethnicity moderates the strength of the relationships between (1) social, emotional, and behavioral (SEB) problems and delinquency and (2) mental health service use and delinquency. We used a nationally representative sample of 727 African American, Caucasian, and Latino youth between the ages of 12-17 who were referred to the child welfare system. Controlling for age, gender, placement instability, maltreatment history, poverty, and urbanicity, linear regression analyses revealed that African American and Latino youth engaged in more delinquent acts than Caucasian youth did. However, service use decreased the likelihood of engaging in more delinquent acts for African Americans. Additional efforts are needed to illuminate and address the contextual and organizational barriers to delivering effective mental health services as a strategy to reduce racial disparities in delinquent behavior. Copyright © 2015 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Functional characterization of GH7 endo-1,4-β-glucanase from Aspergillus fumigatus and its potential industrial application.

PubMed

Bernardi, Aline Vianna; de Gouvêa, Paula Fagundes; Gerolamo, Luis Eduardo; Yonamine, Deborah Kimie; de Lourdes de Lima Balico, Laís; Uyemura, Sergio Akira; Dinamarco, Taisa Magnani

2018-04-30

A gene encoding an endo-1,4-β-glucanase (Afu6g01800) from A. fumigatus was cloned into the vector pET-28a(+) and expressed in the E. coli strain RosettaTM (DE3) pLysS. Sequence analysis indicated that the enzyme Af-EGL7 belonged to the GH7 family. The gene Af-egl7 encoded a protein comprising 460 amino acids, with a CBM1 domain at residues 424-460 and molecular mass of 52 kDa, as estimated by SDS-PAGE. This enzyme was optimally active at pH and temperatures ranging from 4.5 to 5.5 and from 40 to 60 °C, respectively. Mn 2+ addition significantly enhanced the Af-EGL7 cellulase activity by 233%, whereas SDS addition fully inhibited this activity. Higher activity was observed toward β-glucan than toward xyloglucan and CM-Cellulose, suggesting that the enzyme corresponds to a β-1,3-1,4-glucanase. qRT-PCR in different culture media helped to establish the time-course expression profile. Different polysaccharides induced the gene Af-egl7 in a time-dependent manner; in the particular case of the substrate sugarcane exploded bagasse (SEB), Af-egl7 was induced 2500-fold. Upon addition to a commercial cellulase cocktail, Af-EGL7 significantly improved SEB saccharification, which suggested that the enzyme Af-EGL7 had great potential to hydrolyze complex biomass. From a biotechnological point of view, A. fumigatus Af-EGL7 is a promising candidate to enhance enzyme cocktails used in biorefineries such as consolidated bioprocessing. Copyright © 2018 Elsevier Inc. All rights reserved.

A Single-Stranded DNA Aptamer That Selectively Binds to Staphylococcus aureus Enterotoxin B

PubMed Central

DeGrasse, Jeffrey A.

2012-01-01

The bacterium Staphylococcus aureus is a common foodborne pathogen capable of secreting a cocktail of small, stable, and strain-specific, staphylococcal enterotoxins (SEs). Staphylococcal food poisoning (SFP) results when improperly handled food contaminated with SEs is consumed. Gastrointestinal symptoms of SFP include emesis, diarrhea and severe abdominal pain, which manifest within hours of ingesting contaminated food. Immuno-affinity based methods directly detect, identify, and quantify several SEs within a food or clinical sample. However, the success of these assays depends upon the availability of a monoclonal antibody, the development of which is non-trivial and costly. The current scope of the available immuno-affinity based methods is limited to the classical SEs and does not encompass all of the known or emergent SEs. In contrast to antibodies, aptamers are short nucleic acids that exhibit high affinity and specificity for their targets without the high-costs and ethical concerns of animal husbandry. Further, researchers may choose to freely distribute aptamers and develop assays without the proprietary issues that increase the per-sample cost of immuno-affinity assays. This study describes a novel aptamer, selected in vitro, with affinity to staphylococcal enterotoxin B (SEB) that may be used in lieu of antibodies in SE detection assays. The aptamer, designated APTSEB1, successfully isolates SEB from a complex mixture of SEs with extremely high discrimination. This work sets the foundation for future aptamer and assay development towards the entire family of SEs. The rapid, robust, and low-cost identification and quantification of all of the SEs in S. aureus contaminated food is essential for food safety and epidemiological efforts. An in vitro generated library of SE aptamers could potentially allow for the comprehensive and cost-effective analysis of food samples that immuno-affinity assays currently cannot provide. PMID:22438927

The ammonia absorption behavior on Jupiter during 2005-2015

NASA Astrophysics Data System (ADS)

Tejfel, Victor G.; V.G.Tejfel, V.D.Vdovichenko, A.M.Karimov, P.G.Lysenko, , G.A.Kirienko, , V.A.Filippov, G.A.Kharitonova, A.S. Khozhenetz

2017-10-01

V.G.Tejfel, V.D.Vdovichenko, A.M.Karimov, P.G.Lysenko, , G.A.Kirienko, , V.A.Filippov, G.A.Kharitonova, A.S. KhozhenetzFessenkov Astrophysical Institute, Almaty, KazakhstanWe measured the intensity of the 645 and 787 nm NH3 absorption bands in five latitudinal belts of Jupiter (STrZ, SEB, EZ, NEB and NTrZ) during almost full period of its revolution around the Sun: from 2005 to 2015. The variations in the equivalent widths of the bands were investigated. The permanently lowered intensity of the 787 nm NH3 band in NEB is confirmed. There are also some systematic differences in latitudinal and temporal variations between the 645 and 787 nm ammonia bands. The equivalent width of the 787 nm NH3 band was averaged for all years of observations. Its maximum (W = 18.95 ± 0.75 A) corresponds to EZ, its minimum (W = 15.82 ± 0.68 A) corresponds to NEB. The 645 nm NH3 band shows the maximum in SEB (W = 6.78 ± 0.45 A), and the minimum in NTrZ (W = 5.38 ± 0.36 A). The weakened ammonia absorption is also observed in the Great Red Spot. However, this is due to the increased density of the clouds inside the Spot storm, but not to decreased gaseous ammonia abundance, in contrast to NEB. The brightness temperature of GRS in the infrared and millimeter ranges of thermal radiation is lower, in contrast to NEB, where an increased brightness temperature is observed. The enhanced cloud density may explain also a pretty high brightness of GRS observed in strong methane absorption bands such as the 887 nm CH4 band and more long waved ones.

ICAM-1 (CD54) expression on B lymphocytes is associated with their costimulatory function and can be increased by coactivation with IL-1 and IL-7.

PubMed

Dennig, D; Lacerda, J; Yan, Y; Gasparetto, C; O'Reilly, R J

1994-07-01

Recent studies have demonstrated that acute lymphoblastic leukemia-derived pre-B cell lines are deficient in their costimulatory function for T cell proliferation in response to the mitogen Con A and the superantigens TSST-1 and SEB. Stimulation of these pre-B cells with IL-7 increased their costimulatory function which involved the B7/CD28 pathway. In the present study, we stimulated T cells with Con A, TSST-1, and SEB in the presence of peripheral blood B lineage cells that do not constitutively express B7/BB1 on their surface and investigated whether their costimulatory function could also be enhanced by IL-7. We found that, in the presence of IL-1, stimulation with IL-7 increased the costimulatory function of B cells and their surface expression level of ICAM-1 (CD54). We then investigated whether costimulatory B cell function could be inhibited by blocking the ICAM-1/LFA-1 pathway. Addition of anti-ICAM-1 mAb to the coculture of T and B cells inhibited T cell proliferation by approximately 20%. In contrast, addition of anti-LFA-1 beta (CD18) mAb, directed against the T cell ligand of ICAM-1, inhibited T cell proliferation almost completely. To determine the role of ICAM-1 in costimulatory B cell function, we sorted B cells into ICAM-1low-and ICAM-1high-expressing populations. We found that B cells expressing high levels of surface ICAM-1 elicited significantly higher T cell responses than those with low levels, suggesting that the expression level of ICAM-1 on peripheral blood B cells correlates with their costimulatory function.

Multiplex detection of protein toxins using MALDI-TOF-TOF tandem mass spectrometry: application in unambiguous toxin detection from bioaerosol.

PubMed

Alam, Syed Imteyaz; Kumar, Bhoj; Kamboj, Dev Vrat

2012-12-04

Protein toxins, such as botulinum neurotoxins (BoNTs), Clostridium perfringens epsilon toxin (ETX), staphylococcal enterotoxin B (SEB), shiga toxin (STX), and plant toxin ricin, are involved in a number of diseases and are considered as potential agents for bioterrorism and warfare. From a bioterrorism and warfare perspective, these agents are likely to cause maximum damage to a civilian or military population through an inhalational route of exposure and aerosol is considered the envisaged mode of delivery. Unambiguous detection of toxin from aerosol is of paramount importance, both for bringing mitigation protocols into operation and for implementation of effective medical countermeasures, in case a "biological cloud" is seen over a population. A multiplex, unambiguous, and qualitative detection of protein toxins is reported here using tandem mass spectrometry with MALDI-TOF-TOF. The methodology involving simple sample processing steps was demonstrated to identify toxins (ETX, Clostridium perfringes phospholipase C, and SEB) from blind spiked samples. The novel directed search approach using a list of unique peptides was used to identify toxins from a complex protein mixture. The bioinformatic analysis of seven protein toxins for elucidation of unique peptides with conservation status across all known sequences provides a high confidence for detecting toxins originating from any geographical location and source organism. Use of tandem MS data with peptide sequence information increases the specificity of the method. A prototype for generation of aerosol using a nebulizer and collection using a cyclone collector was used to provide a proof of concept for unambiguous detection of toxin from aerosol using precursor directed tandem mass spectrometry combined with protein database searching. ETX prototoxin could be detected from aerosol at 0.2 ppb concentration in aerosol.

CD107a Expression and IFN-γ Production as Markers for Evaluation of Cytotoxic CD3+ CD8+ T Cell Response to CMV Antigen in Women with Recurrent Spontaneous Abortion

PubMed Central

Tarokhian, Batoul; Sherkat, Roya; Nasr Esfahani, Mohamma Hossein; Adib, Minoo; Kiani Esfahani, Abbas; Ataei, Behrooz

2014-01-01

Background: Some evidence has shown a relationship between primary human cytomegalovirus (CMV) infection and pregnancy loss. The impact of CMV infection reactivation during pregnancy on adverse pregnancy outcomes is not completely understood. It is proposed that altered immune response, and therefore, recurrence or reactivation of latent CMV infection may relate to recurrent spontaneous abortion (RSA); however, few data are available in this regard. To find out about any cell mediated defect and reactivation of latent CMV infection in women with RPL, cellular immunity to the virus has been evaluated by specific cytotoxic T lymphocyte (CTL) response to CMV. Materials and Methods: In a case control study, CTL CD107a expression and in- tercellular IFN-γ production in response to CMV pp65 antigen and staphylococcus enterotoxin B (SEB) in women with RSA were assessed by flow cytometric analysis. Forty-four cases with history of recurrent pregnancy and forty-four controls with history of successful pregnancies were included. The FACSCaliber flow cytometer were used for analysis. Results: No significant difference was observed between CD107a expression and IFN-γ production in response to CMV PP65 antigen in RPL patients and control group. How- ever, the cytotoxic response to SEB antigen in patients with RPL was significantly lower than control group (p=0.042). Conclusion: The results of this study show that impaired CD107a expression and IFN-γ production as CTL response to CMV does not appear to be a major contrib- uting and immune incompetence factor in patients with RPL, but cytotoxic T cell response defect to other antigens requires to be assessed further in these patients. PMID:24520502

CD107a Expression and IFN-γ Production as Markers for Evaluation of Cytotoxic CD3+ CD8+ T Cell Response to CMV Antigen in Women with Recurrent Spontaneous Abortion.

PubMed

Tarokhian, Batoul; Sherkat, Roya; Nasr Esfahani, Mohamma Hossein; Adib, Minoo; Kiani Esfahani, Abbas; Ataei, Behrooz

2014-01-01

Some evidence has shown a relationship between primary human cytomegalovirus (CMV) infection and pregnancy loss. The impact of CMV infection reactivation during pregnancy on adverse pregnancy outcomes is not completely understood. It is proposed that altered immune response, and therefore, recurrence or reactivation of latent CMV infection may relate to recurrent spontaneous abortion (RSA); however, few data are available in this regard. To find out about any cell mediated defect and reactivation of latent CMV infection in women with RPL, cellular immunity to the virus has been evaluated by specific cytotoxic T lymphocyte (CTL) response to CMV. In a case control study, CTL CD107a expression and in- tercellular IFN-γ production in response to CMV pp65 antigen and staphylococcus enterotoxin B (SEB) in women with RSA were assessed by flow cytometric analysis. Forty-four cases with history of recurrent pregnancy and forty-four controls with history of successful pregnancies were included. The FACSCaliber flow cytometer were used for analysis. No significant difference was observed between CD107a expression and IFN-γ production in response to CMV PP65 antigen in RPL patients and control group. How- ever, the cytotoxic response to SEB antigen in patients with RPL was significantly lower than control group (p=0.042). The results of this study show that impaired CD107a expression and IFN-γ production as CTL response to CMV does not appear to be a major contrib- uting and immune incompetence factor in patients with RPL, but cytotoxic T cell response defect to other antigens requires to be assessed further in these patients.

Composite polymer membranes for proton exchange membrane fuel cells operating at elevated temperatures and reduced humidities

NASA Astrophysics Data System (ADS)

Zhang, Tao

Proton Exchange Membrane Fuel Cells (PEMFCs) are the leading candidate in the fuel cell technology due to the high power density, solid electrolyte, and low operational temperature. However, PEMFCs operating in the normal temperature range (60-80°C) face problems including poor carbon monoxide tolerance and heat rejection. The poisoning effect can be significantly relieved by operating the fuel cell at elevated temperature, which also improves the heat rejection and electrochemical kinetics. Low relative humidity (RH) operation is also desirable to simplify the reactant humidification system. However, at elevated temperatures, reduced RH PEMFC performance is seriously impaired due to irreversible water loss from presently employed state-of-the-art polymer membrane, Nafion. This thesis focuses on developing polymer electrolyte membranes with high water retention ability for operation in elevated temperature (110-150°C), reduced humidity (˜50%RH) PEMFCs. One approach is to alter Nafion by adding inorganic particles such as TiO2, SiO2, Zr(HPO 4)2, etc. While the presence of these materials in Nafion has proven beneficial, a reduction or no improvement in the PEMFC performance of Nafion/TiO2 and Nafion/Zr(HPO4)2 membranes is observed with reduced particle sizes or increased particle loadings in Nafion. It is concluded that the PEMFC performance enhancement associated with addition of these inorganic particles was not due to the particle hydrophilicity. Rather, the particle, partially located in the hydrophobic region of the membrane, benefits the cell performance by altering the membrane structure. Water transport properties of some Nafion composite membranes were investigated by NMR methods including pulsed field gradient spin echo diffusion, spin-lattice relaxation, and spectral measurements. Compared to unmodified Nafion, composite membranes materials exhibit longer longitudinal relaxation time constant T1. In addition to the Nafion material, sulfonated styrene-ethylene/butylene-styrene triblock copolymer (sSEBS) was investigated as an alternate membrane candidate. sSEBS was modified through introduction of polymer crosslinks using benzephenone as a photoinitiator and addition of a titania co-phase. A photocrosslinked membrane initially containing 15% benzophenone and 3% titania laminated with a 10 mum Nafion layer was found to produce the best PEMFC performance (120°C, 50%RH).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burns, S. P.; Blanken, P. D.; Turnipseed, A. A.

Precipitation changes the physical and biological characteristics of an ecosystem. Using a precipitation-based conditional sampling technique and a 14 year data set from a 25 m micrometeorological tower in a high-elevation subalpine forest, we examined how warm-season precipitation affected the above-canopy diel cycle of wind and turbulence, net radiation R net, ecosystem eddy covariance fluxes (sensible heat H, latent heat LE, and CO 2 net ecosystem exchange NEE) and vertical profiles of scalars (air temperature T a, specific humidity q, and CO 2 dry mole fraction χ c). This analysis allowed us to examine how precipitation modified these variables frommore » hourly (i.e., the diel cycle) to multi-day time-scales (i.e., typical of a weather-system frontal passage). During mid-day we found the following: (i) even though precipitation caused mean changes on the order of 50–70 % to R net, H, and LE, the surface energy balance (SEB) was relatively insensitive to precipitation with mid-day closure values ranging between 90 and 110 %, and (ii) compared to a typical dry day, a day following a rainy day was characterized by increased ecosystem uptake of CO 2 (NEE increased by ≈ 10 %), enhanced evaporative cooling (mid-day LE increased by ≈ 30 W m –2), and a smaller amount of sensible heat transfer (mid-day H decreased by ≈ 70 W m –2). Based on the mean diel cycle, the evaporative contribution to total evapotranspiration was, on average, around 6 % in dry conditions and between 15 and 25 % in partially wet conditions. Furthermore, increased LE lasted at least 18 h following a rain event. At night, even though precipitation (and accompanying clouds) reduced the magnitude of R net, LE increased from ≈ 10 to over 20 W m –2 due to increased evaporation. Any effect of precipitation on the nocturnal SEB closure and NEE was overshadowed by atmospheric phenomena such as horizontal advection and decoupling that create measurement difficulties. Above-canopy mean χ c during wet conditions was found to be about 2–3 μmol mol –1 larger than χ c on dry days. This difference was fairly constant over the full diel cycle suggesting that it was due to synoptic weather patterns (different air masses and/or effects of barometric pressure). Lastly, the effect of clouds on the timing and magnitude of daytime ecosystem fluxes is described.« less

Evaluation of observation-driven evaporation algorithms: results of the WACMOS-ET project

NASA Astrophysics Data System (ADS)

Miralles, Diego G.; Jimenez, Carlos; Ershadi, Ali; McCabe, Matthew F.; Michel, Dominik; Hirschi, Martin; Seneviratne, Sonia I.; Jung, Martin; Wood, Eric F.; (Bob) Su, Z.; Timmermans, Joris; Chen, Xuelong; Fisher, Joshua B.; Mu, Quiaozen; Fernandez, Diego

2015-04-01

Terrestrial evaporation (ET) links the continental water, energy and carbon cycles. Understanding the magnitude and variability of ET at the global scale is an essential step towards reducing uncertainties in our projections of climatic conditions and water availability for the future. However, the requirement of global observational data of ET can neither be satisfied with our sparse global in-situ networks, nor with the existing satellite sensors (which cannot measure evaporation directly from space). This situation has led to the recent rise of several algorithms dedicated to deriving ET fields from satellite data indirectly, based on the combination of ET-drivers that can be observed from space (e.g. radiation, temperature, phenological variability, water content, etc.). These algorithms can either be based on physics (e.g. Priestley and Taylor or Penman-Monteith approaches) or be purely statistical (e.g., machine learning). However, and despite the efforts from different initiatives like GEWEX LandFlux (Jimenez et al., 2011; Mueller et al., 2013), the uncertainties inherent in the resulting global ET datasets remain largely unexplored, partly due to a lack of inter-product consistency in forcing data. In response to this need, the ESA WACMOS-ET project started in 2012 with the main objectives of (a) developing a Reference Input Data Set to derive and validate ET estimates, and (b) performing a cross-comparison, error characterization and validation exercise of a group of selected ET algorithms driven by this Reference Input Data Set and by in-situ forcing data. The algorithms tested are SEBS (Su et al., 2002), the Penman- Monteith approach from MODIS (Mu et al., 2011), the Priestley and Taylor JPL model (Fisher et al., 2008), the MPI-MTE model (Jung et al., 2010) and GLEAM (Miralles et al., 2011). In this presentation we will show the first results from the ESA WACMOS-ET project. The performance of the different algorithms at multiple spatial and temporal scales for the 2005-2007 reference period will be disclosed. The skill of these algorithms to close the water balance over the continents will be assessed by comparisons to runoff data. The consistency in forcing data will allow to (a) evaluate the skill of these five algorithms in producing ET over particular ecosystems, (b) facilitate the attribution of the observed differences to either algorithms or driving data, and (c) set up a solid scientific basis for the development of global long-term benchmark ET products. Project progress can be followed on our website http://wacmoset.estellus.eu. REFERENCES Fisher, J. B., Tu, K.P., and Baldocchi, D.D. Global estimates of the land-atmosphere water flux based on monthly AVHRR and ISLSCP-II data, validated at 16 FLUXNET sites. Remote Sens. Environ. 112, 901-919, 2008. Jiménez, C. et al. Global intercomparison of 12 land surface heat flux estimates. J. Geophys. Res. 116, D02102, 2011. Jung, M. et al. Recent decline in the global land evapotranspiration trend due to limited moisture supply. Nature 467, 951-954, 2010. Miralles, D.G. et al. Global land-surface evaporation estimated from satellite-based observations. Hydrol. Earth Syst. Sci. 15, 453-469, 2011. Mu, Q., Zhao, M. & Running, S.W. Improvements to a MODIS global terrestrial evapotranspiration algorithm. Remote Sens. Environ. 115, 1781-1800, 2011. Mueller, B. et al. Benchmark products for land evapotranspiration: LandFlux-EVAL multi- dataset synthesis. Hydrol. Earth Syst. Sci. 17, 3707-3720, 2013. Su, Z. The Surface Energy Balance System (SEBS) for estimation of turbulent heat fluxes. Hydrol. Earth Syst. Sci. 6, 85-99, 2002.

An automated multi-model based evapotranspiration estimation framework for understanding crop-climate interactions in India

NASA Astrophysics Data System (ADS)

Bhattarai, N.; Jain, M.; Mallick, K.

2017-12-01

A remote sensing based multi-model evapotranspiration (ET) estimation framework is developed using MODIS and NASA Merra-2 reanalysis data for data poor regions, and we apply this framework to the Indian subcontinent. The framework eliminates the need for in-situ calibration data and hence estimates ET completely from space and is replicable across all regions in the world. Currently, six surface energy balance models ranging from widely-used SEBAL, METRIC, and SEBS to moderately-used S-SEBI, SSEBop, and a relatively new model, STIC1.2 are being integrated and validated. Preliminary analysis suggests good predictability of the models for estimating near- real time ET under clear sky conditions from various crop types in India with coefficient of determination 0.32-0.55 and percent bias -15%-28%, when compared against Bowen Ratio based ET estimates. The results are particularly encouraging given that no direct ground input data were used in the analysis. The framework is currently being extended to estimate seasonal ET across the Indian subcontinent using a model-ensemble approach that uses all available MODIS 8-day datasets since 2000. These ET products are being used to monitor inter-seasonal and inter-annual dynamics of ET and crop water use across different crop and irrigation practices in India. Particularly, the potential impacts of changes in precipitation patterns and extreme heat (e.g., extreme degree days) on seasonal crop water consumption is being studied. Our ET products are able to locate the water stress hotspots that need to be targeted with water saving interventions to maintain agricultural production in the face of climate variability and change.

Relationship Between Remotely-sensed Vegetation Indices, Canopy Attributes and Plant Physiological Processes: What Vegetation Indices Can and Cannot Tell Us About the Landscape.

PubMed

Glenn, Edward P; Huete, Alfredo R; Nagler, Pamela L; Nelson, Stephen G

2008-03-28

Vegetation indices (VIs) are among the oldest tools in remote sensing studies. Although many variations exist, most of them ratio the reflection of light in the red and NIR sections of the spectrum to separate the landscape into water, soil, and vegetation. Theoretical analyses and field studies have shown that VIs are near-linearly related to photosynthetically active radiation absorbed by a plant canopy, and therefore to light-dependent physiological processes, such as photosynthesis, occurring in the upper canopy. Practical studies have used time-series VIs to measure primary production and evapotranspiration, but these are limited in accuracy to that of the data used in ground truthing or calibrating the models used. VIs are also used to estimate a wide variety of other canopy attributes that are used in Soil-Vegetation-Atmosphere Transfer (SVAT), Surface Energy Balance (SEB), and Global Climate Models (GCM). These attributes include fractional vegetation cover, leaf area index, roughness lengths for turbulent transfer, emissivity and albedo. However, VIs often exhibit only moderate, non-linear relationships to these canopy attributes, compromising the accuracy of the models. We use case studies to illustrate the use and misuse of VIs, and argue for using VIs most simply as a measurement of canopy light absorption rather than as a surrogate for detailed features of canopy architecture. Used this way, VIs are compatible with "Big Leaf" SVAT and GCMs that assume that canopy carbon and moisture fluxes have the same relative response to the environment as any single leaf, simplifying the task of modeling complex landscapes.

Kinetics of Phase Transition from Lamellar to Hexagonally Packed Cylinders for a Triblock Copolymer in a Selective Solvent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu,Y.; Li, M.; Bansil, R.

2007-01-01

We examined the kinetics of the transformation from the lamellar (LAM) to the hexagonally packed cylinder (HEX) phase for the triblock copolymer, polystyrene-b-poly (ethylene-co-butylene)-b-polystyrene (SEBS) in dibutyl phthalate (DBP), a selective solvent for polystyrene (PS), using time-resolved small-angle X-ray scattering (SAXS). We observe the HEX phase with the EB block in the cores at a lower temperature than that observed for the LAM phase due to the solvent selectivity of DBP for the PS block. Analysis of the SAXS data for a deep temperature quench well below the LAM-HEX transition shows that the transformation occurs in a one-step process. Wemore » calculate the scattering using a geometric model of rippled layers with adjacent layers totally out of phase during the transformation. The agreement of the calculations with the data further supports the continuous transformation mechanism from the LAM to HEX for a deep quench. In contrast, for a shallow quench close to the order-order transition, we find agreement with a two-step nucleation and growth mechanism.« less

Perceived self-competence and relationship experiences in inpatient psychotherapy - a pilot study

PubMed Central

Sammet, Isa; Häfner, Steffen; Leibing, Eric; Lüneburg, Tim; Schauenburg, Henning

2007-01-01

Objective: The patient’s sense of capability in mastering future challenges (“self-competence”) represents an important therapeutic target. To date, empirical findings concerning the influence of the therapeutic relationship on perceived self-competence remain scarce. Against this backdrop, mutual associations between perceived self-competence, symptom distress and various relationship experiences within inpatient psychotherapy are investigated. Methods: 219 inpatients with heterogeneous diagnoses completed the SCL-90-R, the Relationship Questionnaire RQ1 and the Inventory of Interpersonal Problems IIP prior to therapy. Self-competence and relationships to the individual therapist, therapeutic team and fellow patients were assessed weekly using an inpatient questionnaire (SEB). Results: As expected, there were significant negative correlations between self-competence and symptom distress. Patients with more “fearfully avoidant” behavior upon admission experienced relationships during therapy as significantly more negative. Conversely, the quality of relationships to the individual therapist and fellow patients was predictive of a significant part of variance in self-competence upon discharge. Conclusions: A model of mutual interactions is proposed for the variables under investigation. Results suggest that the positive association between the therapeutic relationship and symptom reduction could partly be explained by an improvement in perceived self-competence. PMID:19742295

The AquaDEB project (phase I): Analysing the physiological flexibility of aquatic species and connecting physiological diversity to ecological and evolutionary processes by using Dynamic Energy Budgets

NASA Astrophysics Data System (ADS)

Alunno-Bruscia, Marianne; van der Veer, Henk W.; Kooijman, Sebastiaan A. L. M.

2009-08-01

The European Research Project AquaDEB (2007-2011, http://www.ifremer.fr/aquadeb/) is joining skills and expertise of some French and Dutch research institutes and universities to analyse the physiological flexibility of aquatic organisms and to link it to ecological and evolutionary processes within a common theoretical framework for quantitative bioenergetics [Kooijman, S.A.L.M., 2000. Dynamic energy and mass budgets in biological systems. Cambridge University Press, Cambridge]. The main scientific objectives in AquaDEB are i) to study and compare the sensitivity of aquatic species (mainly molluscs and fish) to environmental variability of natural or human origin, and ii) to evaluate the related consequences at different biological levels (individual, population, ecosystem) and temporal scales (life cycle, population dynamics, evolution). At mid-term life, the AquaDEB collaboration has already yielded interesting results by quantifying bio-energetic processes of various aquatic species (e.g. molluscs, fish, crustaceans, algae) with a single mathematical framework. It has also allowed to federate scientists with different backgrounds, e.g. mathematics, microbiology, ecology, chemistry, and working in different fields, e.g. aquaculture, fisheries, ecology, agronomy, ecotoxicology, climate change. For the two coming years, the focus of the AquaDEB collaboration will be in priority: (i) to compare energetic and physiological strategies among species through the DEB parameter values and to identify the factors responsible for any differences in bioenergetics and physiology; and to compare dynamic (DEB) versus static (SEB) energy models to study the physiological performance of aquatic species; (ii) to consider different scenarios of environmental disruption (excess of nutrients, diffuse or massive pollution, exploitation by man, climate change) to forecast effects on growth, reproduction and survival of key species; (iii) to scale up the models for a few species from the individual level up to the level of evolutionary processes.

The influence of warm-season precipitation on the diel cycle of the surface energy balance and carbon dioxide at a Colorado subalpine forest site

DOE PAGES

Burns, S. P.; Blanken, P. D.; Turnipseed, A. A.; ...

2015-12-15

Precipitation changes the physical and biological characteristics of an ecosystem. Using a precipitation-based conditional sampling technique and a 14 year data set from a 25 m micrometeorological tower in a high-elevation subalpine forest, we examined how warm-season precipitation affected the above-canopy diel cycle of wind and turbulence, net radiation R net, ecosystem eddy covariance fluxes (sensible heat H, latent heat LE, and CO 2 net ecosystem exchange NEE) and vertical profiles of scalars (air temperature T a, specific humidity q, and CO 2 dry mole fraction χ c). This analysis allowed us to examine how precipitation modified these variables frommore » hourly (i.e., the diel cycle) to multi-day time-scales (i.e., typical of a weather-system frontal passage). During mid-day we found the following: (i) even though precipitation caused mean changes on the order of 50–70 % to R net, H, and LE, the surface energy balance (SEB) was relatively insensitive to precipitation with mid-day closure values ranging between 90 and 110 %, and (ii) compared to a typical dry day, a day following a rainy day was characterized by increased ecosystem uptake of CO 2 (NEE increased by ≈ 10 %), enhanced evaporative cooling (mid-day LE increased by ≈ 30 W m –2), and a smaller amount of sensible heat transfer (mid-day H decreased by ≈ 70 W m –2). Based on the mean diel cycle, the evaporative contribution to total evapotranspiration was, on average, around 6 % in dry conditions and between 15 and 25 % in partially wet conditions. Furthermore, increased LE lasted at least 18 h following a rain event. At night, even though precipitation (and accompanying clouds) reduced the magnitude of R net, LE increased from ≈ 10 to over 20 W m –2 due to increased evaporation. Any effect of precipitation on the nocturnal SEB closure and NEE was overshadowed by atmospheric phenomena such as horizontal advection and decoupling that create measurement difficulties. Above-canopy mean χ c during wet conditions was found to be about 2–3 μmol mol –1 larger than χ c on dry days. This difference was fairly constant over the full diel cycle suggesting that it was due to synoptic weather patterns (different air masses and/or effects of barometric pressure). Lastly, the effect of clouds on the timing and magnitude of daytime ecosystem fluxes is described.« less

Multilocus Sequence Typing and Virulence-Associated Gene Profile Analysis of Staphylococcus aureus Isolates From Retail Ready-to-Eat Food in China.

PubMed

Yang, Xiaojuan; Yu, Shubo; Wu, Qingping; Zhang, Jumei; Wu, Shi; Rong, Dongli

2018-01-01

The aim of this study was to characterize the subtypes and virulence profiles of 69 Staphylococcus aureus isolates obtained from retail ready-to-eat food in China. The isolates were analyzed using multilocus sequence typing (MLST) and polymerase chain reaction (PCR) analysis of important virulence factor genes, including the staphylococcal enterotoxin (SE) genes ( sea , seb , sec , sed , see , seg , seh , sei , sej ), the exfoliative toxin genes ( eta and etb ), the toxic shock syndrome toxin-1 gene ( tst ), and the Panton-Valentine leucocidin-encoding gene ( pvl ). The isolates encompassed 26 different sequence types (STs), including four new STs (ST3482, ST3484, ST3485, ST3504), clustered in three clonal complexes and 17 singletons. The most prevalent STs were ST1, ST6, and ST15, constituting 34.8% of all isolates. Most STs (15/26, 57.7%) detected have previously been associated with human infections. All 13 toxin genes examined were detected in the S. aureus isolates, with 84.1% of isolates containing toxin genes. The three most prevalent toxin genes were seb (36.2%), sea (33.3%), and seg (33.3%). The classical SE genes ( sea - see ), which contribute significantly to staphylococcal food poisoning (SFP), were detected in 72.5% of the S. aureus isolates. In addition, pvl , eta , etb , and tst were found in 11.6, 10.1, 10.1, and 7.2% of the S. aureus isolates, respectively. Strains ST6 carrying sea and ST1 harboring sec-seh enterotoxin profile, which are the two most common clones associated with SFP, were also frequently detected in the food samples in this study. This study indicates that these S. aureus isolates present in Chinese ready-to-eat food represents a potential public health risk. These data are valuable for epidemiological studies, risk management, and public health strategies.

Multilocus Sequence Typing and Virulence-Associated Gene Profile Analysis of Staphylococcus aureus Isolates From Retail Ready-to-Eat Food in China

PubMed Central

Yang, Xiaojuan; Yu, Shubo; Wu, Qingping; Zhang, Jumei; Wu, Shi; Rong, Dongli

2018-01-01

The aim of this study was to characterize the subtypes and virulence profiles of 69 Staphylococcus aureus isolates obtained from retail ready-to-eat food in China. The isolates were analyzed using multilocus sequence typing (MLST) and polymerase chain reaction (PCR) analysis of important virulence factor genes, including the staphylococcal enterotoxin (SE) genes (sea, seb, sec, sed, see, seg, seh, sei, sej), the exfoliative toxin genes (eta and etb), the toxic shock syndrome toxin-1 gene (tst), and the Panton-Valentine leucocidin-encoding gene (pvl). The isolates encompassed 26 different sequence types (STs), including four new STs (ST3482, ST3484, ST3485, ST3504), clustered in three clonal complexes and 17 singletons. The most prevalent STs were ST1, ST6, and ST15, constituting 34.8% of all isolates. Most STs (15/26, 57.7%) detected have previously been associated with human infections. All 13 toxin genes examined were detected in the S. aureus isolates, with 84.1% of isolates containing toxin genes. The three most prevalent toxin genes were seb (36.2%), sea (33.3%), and seg (33.3%). The classical SE genes (sea–see), which contribute significantly to staphylococcal food poisoning (SFP), were detected in 72.5% of the S. aureus isolates. In addition, pvl, eta, etb, and tst were found in 11.6, 10.1, 10.1, and 7.2% of the S. aureus isolates, respectively. Strains ST6 carrying sea and ST1 harboring sec-seh enterotoxin profile, which are the two most common clones associated with SFP, were also frequently detected in the food samples in this study. This study indicates that these S. aureus isolates present in Chinese ready-to-eat food represents a potential public health risk. These data are valuable for epidemiological studies, risk management, and public health strategies. PMID:29662467

Spatiotemporal patterns of coral disease prevalence on Heron Island, Great Barrier Reef, Australia

NASA Astrophysics Data System (ADS)

Haapkylä, J.; Melbourne-Thomas, J.; Flavell, M.; Willis, B. L.

2010-12-01

Despite increasing research effort on coral diseases, little is known about factors driving disease dynamics on the Great Barrier Reef (GBR). This is the first study to investigate the temporal patterns of coral disease prevalence and potential drivers of disease around Heron Island, in the southern Capricorn Bunker sector of the GBR. Surveys were conducted in two austral summers and three winters between November 2007 and August 2009 on six sites around the island. Six diseases were detected: brown band syndrome (BrB), growth anomalies (GA), ulcerative white spots (UWS), white syndrome (WS), skeletal eroding band disease (SEB) and black band disease (BBD). The lowest overall mean disease prevalence was 1.87 ± 0.75% (mean ± SE) in November 2007 and the highest 4.22 ± 1.72% in August 2008. There was evidence of seasonality for two diseases: BrB and UWS. This is the first study to report a higher prevalence of BrB in the winter. BrB had a prevalence of 3.29 ± 0.58% in August 2008 and 1.53 ± 0.28% in August 2009, while UWS was the most common syndrome in the summer with a prevalence of 1.12 ± 0.31% in November 2007 and 2.67 ± 0.52% prevalence in January 2008. The prevalence of GAs and SEB did not depend on the season, although the prevalence of GAs increased throughout the study period. WS had a slightly higher prevalence in the summer, but its overall prevalence was low (<0.5%). Sites with high abundance of staghorn Acropora and Montipora were characterised by the highest disease prevalence (12% of Acropora and 3.3% of Montipora species were diseased respectively). These results highlight the correlations between coral disease prevalence, seasonally varying environmental parameters and coral community composition. Given that diseases are likely to reduce the resilience of corals, seasonal patterns in disease prevalence deserve further research.

Enterotoxigenicity and Antimicrobial Resistance of Staphylococcus aureus Isolated from Retail Food in China

PubMed Central

Wang, Wei; Baloch, Zulqarnain; Jiang, Tao; Zhang, Cunshan; Peng, Zixin; Li, Fengqin; Fanning, Séamus; Ma, Aiguo; Xu, Jin

2017-01-01

Staphylococcus aureus is one of the most common causes of zoonotic agent in the world, which are attributable to the contamination of food with enterotoxins. In this study, a total of 1,150 S. aureus isolates were cultured from 27,000 retail foods items from 203 cities of 24 provinces in China in 2015 and were test for antimicrobial susceptibility. Additionally, the role of the genes responsible for the staphylococcal enterotoxins (SEA to SEE), methicillin resistance (mecA) and the toxigenic capabilities were also assessed. The results showed that 4.3% retail foods were contaminated with S. aureus, and 7.9% retail foods isolates were mecA positive. Some 97.6% of S. aureus isolates were resistant to at least one antimicrobial compound, and 57.5% of these were multi drug resistant (MDR). Resistance to penicillin (83.7%, 963/1,150), was common, followed by linezolid (67.7%, 778/1,150) and erythromycin (52.1%, 599/1,150). The isolates cultured from raw meats showed high levels of resistant to tetracycline (42.8%), ciprofloxacin (17.4%), and chloramphenicol (12.0%) and expressed a MDR phenotype (62.4%). A total of 29.7% S. aureus isolates harbored the classical SEs genes (sea, seb, sec, and sed). The sea and seb genes were the most frequent SEs genes detected. Of note, 22% of the SEs genes positive S. aureus harbored two or three SEs genes, and 16 isolates were confirmed with the capacity to simultaneously produce two or three enterotoxin types. Moreover, nearly 50% of the MRSA isolates were positive for at least one SE gene in this study. Therefore, it is important to monitor the antimicrobial susceptibility and enterotoxigenicity of MDR S. aureus and MRSA in the food chain and to use these data to develop food safety measures, designed to reduce the contamination and transmission of this bacterium. PMID:29209290

Radiation and annealing response of WWER 440 beltline welding seams

NASA Astrophysics Data System (ADS)

Viehrig, Hans-Werner; Houska, Mario; Altstadt, Eberhard

2015-01-01

The focus of this paper is on the irradiation response and the effect of thermal annealing in weld materials extracted from decommissioned WWER 440 reactor pressure vessels of the nuclear power plant Greifswald. The characterisation is based on the measurement of the hardness, the yield stress, the Master Curve reference temperature, T0, and the Charpy-V transition temperature through the thickness of multi-layer beltline welding seams in the irradiated and the thermally annealed condition. Additionally, the weld bead structure was characterised by light microscopic studies. We observed a large variation in the through thickness T0 values in the irradiated as well as in thermally annealed condition. The T0 values measured with the T-S-oriented Charpy size SE(B) specimens cut from different thickness locations of the multilayer welding seams strongly depend on the intrinsic weld bead structure along the crack tip. The Master Curve, T0, and Charpy-V, TT47J, based ductile-to-brittle transition temperature progressions through the thickness of the multi-layer welding seam do not correspond to the forecast according to the Russian code. In general, the fracture toughness values at cleavage failure, KJc, measured on SE(B) specimens from the irradiated and large-scale thermally annealed beltline welding seams follow the Master Curve description, but more than the expected number lie outside the curves for 2% and 98% fracture probability. In this case the test standard ASTM E1921 indicates the investigated multi-layer weld metal as not uniform. The multi modal Master Curve based approach describes the temperature dependence of the specimen size adjusted KJc-1T values well. Thermal annealing at 475 °C for 152 h results in the expected decrease of the hardness and tensile strength and the shift of Master Curve and Charpy-V based ductile-to-brittle transition temperatures to lower values.

Evidence of functional cell-mediated immune responses to nontypeable Haemophilus influenzae in otitis-prone children

PubMed Central

Seppanen, Elke; Tan, Dino; Corscadden, Karli J.; Currie, Andrew J.; Richmond, Peter C.; Thornton, Ruth B.

2018-01-01

Otitis media (OM) remains a common paediatric disease, despite advances in vaccinology. Susceptibility to recurrent acute OM (rAOM) has been postulated to involve defective cell-mediated immune responses to common otopathogenic bacteria. We compared the composition of peripheral blood mononuclear cells (PBMC) from 20 children with a history of rAOM (otitis-prone) and 20 healthy non-otitis-prone controls, and assessed innate and cell-mediated immune responses to the major otopathogen nontypeable Haemophilus influenzae (NTHi). NTHi was a potent stimulator of inflammatory cytokine secretion from PBMC within 4 hours, with no difference in cytokine levels produced between PBMC from cases or controls. In the absence of antigen stimulation, otitis-prone children had more circulating Natural Killer (NK) cells (p<0.01), particularly NKdim (CD56lo) cells (p<0.01), but fewer CD4+ T cells (p<0.01) than healthy controls. NTHi challenge significantly increased the proportion of activated (CD107a+) NK cells in otitis-prone and non-otitis-prone children (p<0.01), suggesting that NK cells from otitis-prone children are functional and respond to NTHi. CD8+ T cells and NK cells from both cases and controls produced IFNγ in response to polyclonal stimulus (Staphylococcal enterotoxin B; SEB), with more IFNγ+ CD8+ T cells present in cases than controls (p<0.05) but similar proportions of IFNγ+ NK cells. Otitis-prone children had more circulating IFNγ-producing NK cells (p<0.05) and more IFNγ-producing CD4+ (p<0.01) or CD8+ T-cells (p<0.05) than healthy controls. In response to SEB, more CD107a-expressing CD8+ T cells were present in cases than controls (p<0.01). Despite differences in PBMC composition, PBMC from otitis-prone children mounted innate and T cell-mediated responses to NTHi challenge that were comparable to healthy children. These data provide evidence that otitis-prone children do not have impaired functional cell mediated immunity. PMID:29621281

Enterotoxigenicity and Antimicrobial Resistance of Staphylococcus aureus Isolated from Retail Food in China.

PubMed

Wang, Wei; Baloch, Zulqarnain; Jiang, Tao; Zhang, Cunshan; Peng, Zixin; Li, Fengqin; Fanning, Séamus; Ma, Aiguo; Xu, Jin

2017-01-01

Staphylococcus aureus is one of the most common causes of zoonotic agent in the world, which are attributable to the contamination of food with enterotoxins. In this study, a total of 1,150 S. aureus isolates were cultured from 27,000 retail foods items from 203 cities of 24 provinces in China in 2015 and were test for antimicrobial susceptibility. Additionally, the role of the genes responsible for the staphylococcal enterotoxins (SEA to SEE), methicillin resistance ( mecA ) and the toxigenic capabilities were also assessed. The results showed that 4.3% retail foods were contaminated with S. aureus , and 7.9% retail foods isolates were mecA positive. Some 97.6% of S. aureus isolates were resistant to at least one antimicrobial compound, and 57.5% of these were multi drug resistant (MDR). Resistance to penicillin (83.7%, 963/1,150), was common, followed by linezolid (67.7%, 778/1,150) and erythromycin (52.1%, 599/1,150). The isolates cultured from raw meats showed high levels of resistant to tetracycline (42.8%), ciprofloxacin (17.4%), and chloramphenicol (12.0%) and expressed a MDR phenotype (62.4%). A total of 29.7% S. aureus isolates harbored the classical SEs genes ( sea, seb, sec , and sed ). The sea and seb genes were the most frequent SEs genes detected. Of note, 22% of the SEs genes positive S. aureus harbored two or three SEs genes, and 16 isolates were confirmed with the capacity to simultaneously produce two or three enterotoxin types. Moreover, nearly 50% of the MRSA isolates were positive for at least one SE gene in this study. Therefore, it is important to monitor the antimicrobial susceptibility and enterotoxigenicity of MDR S. aureus and MRSA in the food chain and to use these data to develop food safety measures, designed to reduce the contamination and transmission of this bacterium.

Assessing the Time Variability of Jupiter's Tropospheric Properties from 1996 to 2011

NASA Technical Reports Server (NTRS)

Orton, G. S.; Fletcher, L. N.; Yanamandra-Fisher, P. A.; Simon-Miller, A. A.; Greco, J.; Wakefield, L.

2012-01-01

We acquired and analyzed mid-infrared images of Jupiter's disk at selected wavelengths from NASA's Infrared Telescope Facility (IRTF) from 1996 to 2011, including a period of large-scale changes of cloud color and albedo. We derived the 100-300 mbar temperature structure, together with tracers of vertical motion: the thickness of a 600- mbar cloud layer, the 300-mbar abundance of the condensable gas NH3, and the 400- mbar para- vs. ortho-H2 ratio. The biggest visual change was detected in the normally dark South Equatorial Belt (SEB) that 'faded' to a light color in 2010, during which both cloud thickness and NH3 abundance rose; both returned to their pre-fade levels in 2011, as the SEB regained its normal dark color. The cloud thickness in Jupiter's North Temperate Belt (NTB) increased in 2002, coincident with its visible brightening, and its NH3 abundance spiked in 2002-2003. Jupiter's Equatorial Zone (EZ), a region marked by more subtle but widespread color and albedo change, showed high cloud thickness variability between 2007 and 2009. In Jupiter's North Equatorial Belt (NEB), the cloud thickened in 2005, then slowly decreased to a minimum value in 2010-2011. No temperature variations were associated with any of these changes, but we discovered temperature oscillations of approx.2-4 K in all regions, with 4- or 8-year periods and phasing that was dissimilar in the different regions. There was also no detectable change in the para- vs. ortho-H2 ratio over time, leading to the possibility that it is driven from much deeper atmospheric levels and may be time-invariant. Our future work will continue to survey the variability of these properties through the Juno mission, which arrives at Jupiter in 2016, and to connect these observations with those made using raster-scanned images from 1980 to 1993 (Orton et al. 1996 Science 265, 625).

Encapsulating Networks of Droplet Interface Bilayers in a Thermoreversible Organogel.

PubMed

Challita, Elio J; Najem, Joseph S; Monroe, Rachel; Leo, Donald J; Freeman, Eric C

2018-04-24

The development of membrane-based materials that exhibit the range and robustness of autonomic functions found in biological systems remains elusive. Droplet interface bilayers (DIBs) have been proposed as building blocks for such materials, owing to their simplicity, geometry, and capability for replicating cellular phenomena. Similar to how individual cells operate together to perform complex tasks and functions in tissues, networks of functionalized DIBs have been assembled in modular/scalable networks. Here we present the printing of different configurations of picoliter aqueous droplets in a bath of thermoreversible organogel consisting of hexadecane and SEBS triblock copolymers. The droplets are connected by means of lipid bilayers, creating a network of aqueous subcompartments capable of communicating and hosting various types of chemicals and biomolecules. Upon cooling, the encapsulating organogel solidifies to form self-supported liquid-in-gel, tissue-like materials that are robust and durable. To test the biomolecular networks, we functionalized the network with alamethicin peptides and alpha-hemolysin (αHL) channels. Both channels responded to external voltage inputs, indicating the assembly process does not damage the biomolecules. Moreover, we show that the membrane properties may be regulated through the deformation of the surrounding gel.

Efficient protein immobilization on polyethersolfone electrospun nanofibrous membrane via covalent binding for biosensing applications.

PubMed

Mahmoudifard, Matin; Soudi, Sara; Soleimani, Masoud; Hosseinzadeh, Simzar; Esmaeili, Elaheh; Vossoughi, Manouchehr

2016-01-01

In this paper we introduce novel strategy for antibody immobilization using high surface area electrospun nanofibrous membrane based on ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling chemistry. To present the high performance of proposed biosensors, anti-staphylococcus enterotoxin B (anti-SEB) was used as a model to demonstrate the utility of our proposed system. Polymer solution of polyethersolfone was used to fabricate fine nanofibrous membrane. Moreover, industrial polyvinylidene fluoride membrane and conventional microtiter plate were also used to compare the efficiency of antibody immobilization. Scanning electron microscopy images were taken to study the morphology of the membranes. The surface activation of nanofibrous membrane was done with the help of O2 plasma. PES nanofibrous membrane with carboxyl functional groups for covalent attachment of antibodies were treated by EDC/NHS coupling agent. The quantity of antibody immobilization was measured by enzyme-linked immuno sorbent assay (ELISA) method. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) spectroscopy was performed to confirm the covalent immobilization of antibody on membrane. Atomic force microscopy, scanning electron microscopy and invert fluorescence microscopy were used to analyze the antibody distribution pattern on solid surfaces. Results show that oxygen plasma treatment effectively increased the amount of antibody immobilization through EDC/NHS coupling chemistry. It was found that the use of nanofibrous membrane causes the improved detection signal of ELISA based biosensors in comparison to the standard assay carried out in the 96-well microtiter plate. This method has the potential to improve the ELISA-based biosensor and we believe that this technique can be used in various biosensing methods. Copyright © 2015. Published by Elsevier B.V.

Resources for Radiation Test Data

NASA Technical Reports Server (NTRS)

O'Bryan, Martha V.; Casey, Megan C.; Lauenstein, Jean-Marie; LaBel, Ken

2016-01-01

The performance of electronic devices in a space radiation environment is often limited by susceptibility to single-event effects (SEE), total ionizing dose (TID), and displacement damage (DD). Interpreting the results of SEE, TID, and DD testing of complex devices is quite difficult given the rapidly changing nature of both technology and the related radiation issues. Radiation testing is performed to establish the sensitivities of candidate spacecraft electronics to single-event upset (SEU), single-event latchup (SEL), single-event gate rupture (SEGR), single-event burnout (SEB), single-event transients (SETs), TID, and DD effects. Knowing where to search for these test results is a valuable resource for the aerospace engineer or spacecraft design engineer. This poster is intended to be a resource tool for finding radiation test data.

An Entitlement Approach to Address the Water-Energy-Food Nexus in Rural India

NASA Astrophysics Data System (ADS)

Siegfried, T. U.; Fishman, R.; Modi, V.; Lall, U.

2008-12-01

Groundwater mining in India is one of the biggest water related present and future challenges of South Asia. In the agricultural sector, the negative impact from groundwater depletion is complex and affects farmers directly and indirectly in different ways according to their existing dependence on access to groundwater for irrigation. It stems from a) a reduction in buffer capacity of groundwater as a source of backup supply in critical times of drought, b) the deprivation of access to groundwater of those farmers that cannot raise the capital to continuously drill deeper so as to chase the declining groundwater table and c) the constant reduction of per pump well yield due to the declining water tables given more or less constant pumping energy supply. As a result, rural incomes have become less reliable and household as well as national level food security are increasingly compromised. It is feared that the current deterioration of the national food security situation in India might not easily be reversed due to the unsustainable nature of consumptive groundwater use over the past decades. Access to electricity and subsidized power so as to pump groundwater for irrigation have played a critical role in increasing food production thus linking the energy and agricultural sector. The current rural public finance mechanism is highly ineffective, however, and trapped in an inefficient equilibrium. The deficiencies are that low cost and low quality electricity for agriculture likely translate into wasteful groundwater as well as inefficient energy use and thus lead to resource depletion and contribute to an erosion of the rural electricity distribution system. It is estimated that the current commercial losses to the State Electricity Boards (SEBs) amount to about 23 percent of the gross fiscal deficit of the states. The original intent of the rural subsidy program is thus lost and the current system in urgent need of repair. The uncertain future development of energy prices and rainfall patterns due to climate change only enhance these concerns. Given these deficiencies, any corrective strategy should at least target the following long-term policy goals: a) increase the efficiency of rural electricity consumption in terms of grain production and rural income, b) providing the farmers greater flexibility with timely, high quality energy and more efficient means of production, c) enable proper energy accounting on the use side so as to recover costs at sufficient levels for the SEBs and thus enable long-term investments in energy infrastructure and d) secure and eventually increase agricultural production without depleting groundwater resources over the long run. We will present an entitlement approach with which the above issues can be addressed in the future. A case study example from the semi-arid Telangana Region in Andhra Pradesh will be discussed in depth and preliminary results shown.

An ELISA Lab-on-a-Chip (ELISA-LOC).

PubMed

Rasooly, Avraham; Bruck, Hugh A; Kostov, Yordan

2013-01-01

Laminated object manufacturing (LOM) technology using polymer sheets is an easy and affordable method for rapid prototyping of Lab-on-a-Chip (LOC) systems. It has recently been used to fabricate a miniature 96 sample ELISA lab-on-a-chip (ELISA-LOC) by integrating the washing step directly into an ELISA plate. LOM has been shown to be capable of creating complex 3D microfluidics through the assembly of a stack of polymer sheets with features generated by laser micromachining and by bonding the sheets together with adhesive. A six layer ELISA-LOC was fabricated with an acrylic (poly(methyl methacrylate) (PMMA)) core and five polycarbonate layers micromachined by a CO(2) laser with simple microfluidic features including a miniature 96-well sample plate. Immunological assays can be carried out in several configurations (1 × 96 wells, 2 × 48 wells, or 4 × 24 wells). The system includes three main functional elements: (1) a reagent loading fluidics module, (2) an assay and detection wells plate, and (3) a reagent removal fluidics module. The ELISA-LOC system combines several biosensing elements: (1) carbon nanotube (CNT) technology to enhance primary antibody immobilization, (2) sensitive ECL (electrochemiluminescence) detection, and (3) a charge-coupled device (CCD) detector for measuring the light signal generated by ECL. Using a sandwich ELISA assay, the system detected Staphylococcal enterotoxin B (SEB) at concentrations as low as 0.1 ng/ml, a detection level similar to that reported for conventional ELISA. ELISA-LOC can be operated by a syringe and does not require power for operation. This simple point-of-care (POC) system is useful for carrying out various immunological assays and other complex medical assays without the laboratory required for conventional ELISA, and therefore may be more useful for global healthcare delivery.

Relationship Between Remotely-sensed Vegetation Indices, Canopy Attributes and Plant Physiological Processes: What Vegetation Indices Can and Cannot Tell Us About the Landscape

PubMed Central

Glenn, Edward P.; Huete, Alfredo R.; Nagler, Pamela L.; Nelson, Stephen G.

2008-01-01

Vegetation indices (VIs) are among the oldest tools in remote sensing studies. Although many variations exist, most of them ratio the reflection of light in the red and NIR sections of the spectrum to separate the landscape into water, soil, and vegetation. Theoretical analyses and field studies have shown that VIs are near-linearly related to photosynthetically active radiation absorbed by a plant canopy, and therefore to light-dependent physiological processes, such as photosynthesis, occurring in the upper canopy. Practical studies have used time-series VIs to measure primary production and evapotranspiration, but these are limited in accuracy to that of the data used in ground truthing or calibrating the models used. VIs are also used to estimate a wide variety of other canopy attributes that are used in Soil-Vegetation-Atmosphere Transfer (SVAT), Surface Energy Balance (SEB), and Global Climate Models (GCM). These attributes include fractional vegetation cover, leaf area index, roughness lengths for turbulent transfer, emissivity and albedo. However, VIs often exhibit only moderate, non-linear relationships to these canopy attributes, compromising the accuracy of the models. We use case studies to illustrate the use and misuse of VIs, and argue for using VIs most simply as a measurement of canopy light absorption rather than as a surrogate for detailed features of canopy architecture. Used this way, VIs are compatible with “Big Leaf” SVAT and GCMs that assume that canopy carbon and moisture fluxes have the same relative response to the environment as any single leaf, simplifying the task of modeling complex landscapes. PMID:27879814

Intercomparison of four remote-sensing-based energy balance methods to retrieve surface evapotranspiration and water stress of irrigated fields in semi-arid climate

NASA Astrophysics Data System (ADS)

Chirouze, J.; Boulet, G.; Jarlan, L.; Fieuzal, R.; Rodriguez, J. C.; Ezzahar, J.; Er-Raki, S.; Bigeard, G.; Merlin, O.; Garatuza-Payan, J.; Watts, C.; Chehbouni, G.

2014-03-01

Instantaneous evapotranspiration rates and surface water stress levels can be deduced from remotely sensed surface temperature data through the surface energy budget. Two families of methods can be defined: the contextual methods, where stress levels are scaled on a given image between hot/dry and cool/wet pixels for a particular vegetation cover, and single-pixel methods, which evaluate latent heat as the residual of the surface energy balance for one pixel independently from the others. Four models, two contextual (S-SEBI and a modified triangle method, named VIT) and two single-pixel (TSEB, SEBS) are applied over one growing season (December-May) for a 4 km × 4 km irrigated agricultural area in the semi-arid northern Mexico. Their performance, both at local and spatial standpoints, are compared relatively to energy balance data acquired at seven locations within the area, as well as an uncalibrated soil-vegetation-atmosphere transfer (SVAT) model forced with local in situ data including observed irrigation and rainfall amounts. Stress levels are not always well retrieved by most models, but S-SEBI as well as TSEB, although slightly biased, show good performance. The drop in model performance is observed for all models when vegetation is senescent, mostly due to a poor partitioning both between turbulent fluxes and between the soil/plant components of the latent heat flux and the available energy. As expected, contextual methods perform well when contrasted soil moisture and vegetation conditions are encountered in the same image (therefore, especially in spring and early summer) while they tend to exaggerate the spread in water status in more homogeneous conditions (especially in winter). Surface energy balance models run with available remotely sensed products prove to be nearly as accurate as the uncalibrated SVAT model forced with in situ data.

Charge generation by heavy ions in power MOSFETs, burnout space predictions, and dynamic SEB sensitivity

NASA Technical Reports Server (NTRS)

Stassinopoulos, E. G.; Brucker, G. J.; Calvel, P.; Baiget, A.; Peyrotte, C.; Gaillard, R.

1992-01-01

The transport, energy loss, and charge production of heavy ions in the sensitive regions of IRF 150 power MOSFETs are described. The dependence and variation of transport parameters with ion type and energy relative to the requirements for single event burnout in this part type are discussed. Test data taken with this power MOSFET are used together with analyses by means of a computer code of the ion energy loss and charge production in the device to establish criteria for burnout and parameters for space predictions. These parameters are then used in an application to predict burnout rates in a geostationary orbit for power converters operating in a dynamic mode. Comparisons of rates for different geometries in simulating SEU (single event upset) sensitive volumes are presented.

Nevus sebáceo cerebriforme: uma rara apresentação*

PubMed Central

da Cunha Filho, Roberto Rheingantz; Fezer, Aline Peluso; Lorencette, Nádia Aparecida

2015-01-01

A 13-year-old boy presented congenital, raised, yellowish colored plaques with fibroelastic consistency, which were velvety in appearance, alopecic, with clearly defined limits and sulci or well-marked meandering invaginations, a cerebriform appearance on the upper part of the right ear, accompanied by alopecia in the temporomandibular region-parietal. The lesion was asymptomatic. Histopathologic examination revealed acanthosis, hyperkeratosis, papillomatosis and follicular plugging in the epidermis. The upper dermis showed underdeveloped hair follicles with sebaceous glands, consistent with sebaceous nevus. There were no skeletal, cardiological, ophthalmological or neuropsychomotor changes; nor were there any records of relevant pathologies in the family history. The patient complained of his appearance, experiencing aesthetic and social issues. Following a diagnosis of cerebriform nevus sebaceous, complete excision was performed with excellent aesthetic results. PMID:26312703

Categorizing Weapons of Mass Destruction Biological Agents into Postmortem Risk Groups

DTIC Science & Technology

2012-12-20

toxin  •Marburg  • Smallpox  •Brucellosis  •Melioidosis  • Staphylococcal Entertoxin B (SEB)  •Chikungunya  •Mycotoxins  • Tularemia   •Cholera...Marburg, 9.0 Saxitoxin, 6.25   Lassa fever, 8.75 VEE, 6.0   vCJD, 8.75 WEE, 6.0   Smallpox, 8.5 Tularemia , 6.0   Botulinum toxin, 7.75 Junin/Marchupo...WEE, 5.0     VEE, 5.0     Tularemia , 5.0     Junin/Marchupo, 5.0      Ricin, 4.75     Q fever, 4.75     Rift Valley Fever, 4.75      Mycotoxins

Liquid Crystal Formation from Sunflower Oil: Long Term Stability Studies.

PubMed

da Rocha-Filho, Pedro Alves; Maruno, Mônica; Ferrari, Márcio; Topan, José Fernando

2016-06-09

The Brazilian biodiversity offers a multiplicity of raw materials with great potential in cosmetics industry applications. Some vegetable oils and fatty esters increase skin hydration by occlusivity, keeping the skin hydrated and with a shiny appearance. Sunflower (Helianthus annus L.) oil is widely employed in cosmetic emulsions in the form of soaps, creams, moisturizers and skin cleansers due to the presence of polyphenols and its high vitamin E content. Liquid crystals are systems with many applications in both pharmaceutical and cosmetic formulations and are easily detected by microscopy under polarized light due to their birefringence properties. The aim of this research was to develop emulsions from natural sunflower oil for topical uses. Sunflower oil (75.0% w/w) was combined with liquid vaseline (25.0% w/w) employing a natural self-emulsifying base (SEB) derivative. The high temperature of the emulsification process did not influence the antioxidant properties of sunflower oil. Fatty esters were added to cosmetic formulations and extended stability tests were performed to characterize the emulsions. Fatty esters like cetyl palmitate and cetyl ester increase the formation of anisotropic structures. O/W emulsions showed acidic pH values and pseudoplastic behavior. The presence of a lamellar phase was observed after a period of 90 days under different storage conditions.

A bioanalytical platform for simultaneous detection and quantification of biological toxins.

PubMed

Weingart, Oliver G; Gao, Hui; Crevoisier, François; Heitger, Friedrich; Avondet, Marc-André; Sigrist, Hans

2012-01-01

Prevalent incidents support the notion that toxins, produced by bacteria, fungi, plants or animals are increasingly responsible for food poisoning or intoxication. Owing to their high toxicity some toxins are also regarded as potential biological warfare agents. Accordingly, control, detection and neutralization of toxic substances are a considerable economic burden to food safety, health care and military biodefense. The present contribution describes a new versatile instrument and related procedures for array-based simultaneous detection of bacterial and plant toxins using a bioanalytical platform which combines the specificity of covalently immobilized capture probes with a dedicated instrumentation and immuno-based microarray analytics. The bioanalytical platform consists of a microstructured polymer slide serving both as support of printed arrays and as incubation chamber. The platform further includes an easy-to-operate instrument for simultaneous slide processing at selectable assay temperature. Cy5 coupled streptavidin is used as unifying fluorescent tracer. Fluorescence image analysis and signal quantitation allow determination of the toxin's identity and concentration. The system's performance has been investigated by immunological detection of Botulinum Neurotoxin type A (BoNT/A), Staphylococcal enterotoxin B (SEB), and the plant toxin ricin. Toxins were detectable at levels as low as 0.5-1 ng · mL(-1) in buffer or in raw milk.

Long-term energy balance and vegetation water stress monitoring of Mediterranean oak savanna using satellite thermal data

NASA Astrophysics Data System (ADS)

González-Dugo, Maria P.; Chen, Xuelong; Andreu, Ana; Carpintero, Elisabet; Gómez-Giraldez, Pedro; Su, Z.(Bob)

2017-04-01

Drought is one of the major hazards faced by natural and cropped vegetation in the Mediterranean Sea Basin. Water scarcity is likely to be worsened under the predicted conditions of climate change, which is expected to make this region both warmer and drier. A Holm oak savanna, known as dehesa in Spain and montado in Portugal, is an agro-silvo-pastoral system occupying more than 3 million hectares the Iberian Peninsula and Greece. It consists of widely-spaced oak trees (mostly Quercus ilex L.), combined with crops, pasture and Mediterranean shrubs. This ecosystem is considered an example of sustainable land use, supporting a large number of species and diversity of habitats and for its importance in rural economy. A similar ecosystem is worldwide distributed in areas with Mediterranean climate (as California or South Africa) and shares structural and functional properties with tropical savannas in Africa, Australia and South America. Remote sensing time series can assist the monitoring of the energy balance components, with special attention to the evapotranspiration and vegetation water stress over these areas. Long-term data analysis may improve our understanding of the functioning of the system, helping to assess drought impacts and leading to reduce the economic and environmental vulnerability of this ecosystem. This work analyzes the evolution the surface energy balance components, mapping the evapotranspiration and moisture stress of holm oak woodlands of Spain and Portugal during the last 15 years (2001-2015). The surface energy balance model (SEBS) has been applied over the Iberian Peninsula on a monthly time scale and 0.05° spatial resolution, using multi-satellite and meteorological forcing data. Modelled energy and water fluxes have been validated using ground measurements of two eddy covariance towers located in oak savanna sites during 3 years, resulting in moderate deviations from observations (10-25 W/m2). The departure of actual ET from the potential rate, expected under optimum soil water conditions, has been used to assess the water stress of the system. An annual drought index has been calculated based on this relative ET, in order to compare the main drought events occurred during the study period. Two generalised events (2005 and 2012) and a partial one (2009) have been characterised by analysing the evaporative stress time series, performing a detailed comparison over the two eddy covariance tower sites and a general one over the entire oak savanna area of the Peninsula.

Increased Th1 and Th2 allergen-induced cytokine responses in children with atopic disease.

PubMed

Smart, J M; Kemp, A S

2002-05-01

Polyclonal cytokine responses following stimulation of T cells with mitogens or superantigens provides information on cytokine production from a wide range of T cells. Alternatively allergen-induced T cell responses can provide information on cytokine production by allergen-reactive T cells. While there is evidence of increased Th2 and reduced Th1 cytokine production following T cell stimulation with non-specific mitogens and superantigens, the evidence that Th1 cytokine production to allergens is decreased in line with a postulated imbalance in Th1/Th2 responses is unclear, with studies finding decreased, no difference or increased IFN-gamma responses to allergens in atopic subjects. To examine childhood polyclonal and allergen-induced cytokine responses in parallel to evaluate cytokine imbalances in childhood atopic disease. PBMC cytokine responses were examined in response to a polyclonal stimulus, staphylococcal superantigen (SEB), in parallel with two inhalant allergens, house dust mite (HDM) and rye grass pollen (RYE), and an ingested allergen, ovalbumin (OVA), in (a) 35 healthy children (non-atopic) and (b) 36 children with atopic disease (asthma, eczema and/or rhinitis) (atopic). Atopic children had significantly reduced IFN-gamma and increased IL-4 and IL-5 but not IL13 production to SEB superantigen stimulation when compared with non-atopic children. HDM and RYE allergens stimulated significantly increased IFN-gamma, IL-5 and IL-13, while OVA stimulated significantly increased IFN-gamma production in atopic children. We show that a polyclonal stimulus induces a reduced Th1 (IFN-gamma) and increased Th2 (IL-4 and IL-5) cytokine pattern. In contrast, the allergen-induced cytokine responses in atopic children were associated with both increased Th1 (INF-gamma) and Th2 (IL-5 and IL-13) cytokine production. The increased Th1 response to allergen is likely to reflect prior sensitization and indicates that increases in both Th1 and Th2 cytokine production to allergens exists concomitantly with a decreased Th1 response to a polyclonal stimulus in atopic children.

A Summary of NASA Related Contributions for the Remote Sensing of Evapotranspiration in Support of Water Management and Agriculture

NASA Technical Reports Server (NTRS)

Toll, David; Doorn, Brad; Lawford, Rick; Anderson, Martha; Allen, Rick; Martin, Timothy; Wood, Eric; Ferguson, Craig

2010-01-01

The amount of evapotranspiration (ET) to the atmosphere can account for 60% or more of the water loss in many semi-arid locations, and can critically affect local economies tied to agriculture, recreation, hydroelectric power, ecosystems, and numerous other water-related areas. NASA supports many activities using satellite and Earth science data to more accurately and cost effectively estimate ET. NASA ET related work includes the research, development and application of techniques. The free and open access of NASA satellite data and products now permits a much wider application of ET mapping. Typically the NASA supported approaches ranges from large regional and continental ET mapping using MODIS (also with AIRS and CERES), GRACE (gravimetric water balance), geostationary (e.g., GOES and Meteosat for near continental sca|e), land surface modeling (i.e, Land Data Assimilation Systems) to fine scale mapping such as provided bvLandsatdata(<100 m). Usually satellite or airborne thermal imagery are used as input to an ET estimated surface energy balance based approach. There are currently several of these ET approaches under development and implementation including 'METRIC', 'SEBS', 'ALEXI/DisALEXI', etc.. One exception is an approach using GRACE satellite data that estimates the terrestrial water storage using gravimetric data over large areas and estimates ET indirectly. Also land surface modeling within the context of data assimilation and integration schemes provides the capability to integrate in situ, ancillary and satellite together to provide a spatially and synoptic estimates of ET also for use to provide for short-term ET predictions. We will summarize NASA related activities contributing to the improved estimation of ET for water management and agriculture with an emphasis on the Western U3.. This summary includes a description of ET projects in the Middle Rio Grande, Yakima, North Platte and other selected basins in the western US. We will also discuss plans to further address ET applications through working with the USDA and the Group on Earth Observations (GEO) to extend and evaluate western U.S. ET mapping to other parts of the U.S. and internationally.

Investigation of the Semicoa SCF9550 and the International Rectifier IRHM57260SE for Single-Event Gate Rapture and Single-Event Burnout : NASA Electronic Parts and Packaging (NEPP) Program Office of Safety and Mission Assurance

NASA Technical Reports Server (NTRS)

Scheick, Leif

2011-01-01

Single-event-effect test results for hi-rel total-dose-hardened power MOSFETs are presented in this report. TheSCF9550 from Semicoa and the IRHM57260SE from International Rectifier were tested to NASA test condition/standards and requirements.The IRHM57260SE performed much better when compared to previous testing. These initial results confirm that parts from the Temecula line are marginally comparable to the El Segundo line. The SCF9550 from Semicoa was also tested and represents the initial parts offering from this vendor. Both parts experienced single-event gate rupture (SEGR) and single-event burnout (SEB). All of the SEGR was from gate to drain.

Genetic analysis and ethnic affinities from two Scytho-Siberian skeletons.

PubMed

Ricaut, François-Xavier; Keyser-Tracqui, Christine; Cammaert, Laurence; Crubézy, Eric; Ludes, Bertrand

2004-04-01

We extracted DNA from two skeletons belonging to the Sytho-Siberian population, which were excavated from the Sebÿstei site (dating back 2,500 years) in the Altai Republic (Central Asia). Ancient DNA was analyzed by autosomal short tandem repeats (STRs) and by the sequencing of the hypervariable region 1 (HV1) of the mitochondrial DNA (mtDNA) control region. The results showed that these two skeletons were not close relatives. Moreover, their haplogroups were characteristic of Asian populations. Comparison with the haplogroup of 3,523 Asian and American individuals linked one skeleton with a putative ancestral paleo-Asiatic population and the other with Chinese populations. It appears that the genetic study of ancient populations of Central Asia brings important elements to the understanding of human population movements in Asia. Copyright 2003 Wiley-Liss, Inc.

Highlight on the dynamic organization of the nucleus.

PubMed

Thorpe, Stephen D; Charpentier, Myriam

2017-01-02

The last decade has seen rapid advances in our understanding of the proteins of the nuclear envelope, which have multiple roles including positioning the nucleus, maintaining its structural organization, and in events ranging from mitosis and meiosis to chromatin positioning and gene expression. Diverse new and stimulating results relating to nuclear organization and genome function from across kingdoms were presented in a session stream entitled "Dynamic Organization of the Nucleus" at this year's Society of Experimental Biology (SEB) meeting in Brighton, UK (July 2016). This was the first session stream run by the Nuclear Dynamics Special Interest Group, which was organized by David Evans, Katja Graumann (both Oxford Brookes University, UK) and Iris Meier (Ohio State University, USA). The session featured presentations on areas relating to nuclear organization across kingdoms including the nuclear envelope, chromatin organization, and genome function.

Monoclonal antibodies and toxins--a perspective on function and isotype.

PubMed

Chow, Siu-Kei; Casadevall, Arturo

2012-06-01

Antibody therapy remains the only effective treatment for toxin-mediated diseases. The development of hybridoma technology has allowed the isolation of monoclonal antibodies (mAbs) with high specificity and defined properties, and numerous mAbs have been purified and characterized for their protective efficacy against different toxins. This review summarizes the mAb studies for 6 toxins--Shiga toxin, pertussis toxin, anthrax toxin, ricin toxin, botulinum toxin, and Staphylococcal enterotoxin B (SEB)--and analyzes the prevalence of mAb functions and their isotypes. Here we show that most toxin-binding mAbs resulted from immunization are non-protective and that mAbs with potential therapeutic use are preferably characterized. Various common practices and caveats of protection studies are discussed, with the goal of providing insights for the design of future research on antibody-toxin interactions.

Monoclonal Antibodies and Toxins—A Perspective on Function and Isotype

PubMed Central

Chow, Siu-Kei; Casadevall, Arturo

2012-01-01

Antibody therapy remains the only effective treatment for toxin-mediated diseases. The development of hybridoma technology has allowed the isolation of monoclonal antibodies (mAbs) with high specificity and defined properties, and numerous mAbs have been purified and characterized for their protective efficacy against different toxins. This review summarizes the mAb studies for 6 toxins—Shiga toxin, pertussis toxin, anthrax toxin, ricin toxin, botulinum toxin, and Staphylococcal enterotoxin B (SEB)—and analyzes the prevalence of mAb functions and their isotypes. Here we show that most toxin-binding mAbs resulted from immunization are non-protective and that mAbs with potential therapeutic use are preferably characterized. Various common practices and caveats of protection studies are discussed, with the goal of providing insights for the design of future research on antibody-toxin interactions. PMID:22822456

Spatial Observation and Models for Crop Water Use in Australia (Invited)

NASA Astrophysics Data System (ADS)

Hafeez, M. M.; Chemin, Y.; Rabbani, U.

2009-12-01

Recent drought in Australia and concerns about climate change have highlighted the need to manage agricultural water resources more sustainably, especially in the Murray Darling Basin which accounts for more than 70% of water for crop production. For Australian continent, approximately 90% of the precipitation that falls on the land is returned back to the atmosphere through actual evapotranspiration (ET) process. However, despite its significance nationally, it is almost impossible to measure or observe it directly at a meaningful scale in space and time through traditional point-based methods. Since late 1990's, the optical-thermal remote sensing satellite data has been extensively used for mapping of actual ET from farm to catchment scales in Australia. Numerous ET algorithms have been developed to make use of remote sensing data acquired by optical-thermal sensors mounted on airborne and satellite platforms. This article concentrates on the Murrumbidgee catchment, where ground truth data has been collected on a fortnightly basis since 2007 using two Eddy Covariance Systems (ECS) and two Large Aperture Scintillometers (LAS). Their setup absorbed variability in the landscape to measure ET-related fluxes. The ground truthing measurement data includes leaf area index (LAI) from LICOR 2000, soil heat fluxes from HuskeFlux, crop reflectance data from CROPScan and from a thermal radiometer. UAV drone equipped with multispectral scanner and thermal imager was used to get very high spatial resolution NDVI and surface temperature maps over the selected farms. This large array of high technology instruments have been used to collect specific measurements within various micro-ecosystems available in our study area. This article starts by an overview of common ET estimation algorithms based on satellite remote sensing data. The algorithms are SEBAL, METRIC, Simplified Surface Energy Balance, Two Source Energy Balance and SEBS. They are used in Australia at both regional and catchment scale for mapping actual ET using imagery from Landsat 5TM/7ETM+ and Terra-MODIS sensors. Results of ET derived from various remote sensing algorithms are matched well against the ECS and LAS data sets. These high-tech observation system are used to collect specific ground truth data to develop new empirical and semi-empirical relationship for creating a Spatial Algorithm for Mapping ET (SAM-ET) dedicated to Australian agro-ecosystems. Such estimates can underpin crop water use, crop water productivity, food security, carbon sequestration and environmental flow requirements to enhance the sustainability of agricultural systems. The next frontier is to integrate these data and models to deliver a decision support system to irrigation managers for coordinating water supply and demand, to help match crop water requirement closely in near real time environment.

Enterotoxin Gene Cluster-Encoded SEI and SElN from Staphylococcus aureus Isolates are Crucial for the Induction of Human Blood Cell Proliferation and Pathogenicity in Rabbits.

PubMed

Roetzer, Andreas; Gruener, Corina S; Haller, Guenter; Beyerly, John; Model, Nina; Eibl, Martha M

2016-10-28

Among the toxin family of bacterial superantigens, the six members of the enterotoxin gene cluster (egc) seem to have unusual characteristics. They are present in the majority of Staphylococcus aureus strains, but their role in disease remains uncertain. We assessed secretion levels, immunogenicity, and toxicity of native and recombinant egc proteins. After having developed enzyme-linked immunosorbent assays, we found different quantities of egc proteins secreted by bacterial isolates. Supernatants induced proliferation of human peripheral blood mononuclear cells. However, purified recombinant egc proteins were shown to have differing superantigenicity potentials. Immunization with identical amounts of all members of egc, and the prominent toxic agent SEB, resulted in neutralizing antisera. Two egc proteins, SEI and SE l N, were found to play a predominant role within the cluster. Both displayed the highest potential to activate blood cells, and were essential to be neutralized in supernatants. The application of a supernatant of a strain bearing only egc was sufficient for a lethal outcome in a rabbit model. Again, neutralization of SEI and SE l N led to the survival of all tested animals. Finally, nanogram amounts of purified rSEI and rSE l N led to lethality in vivo, pointing out the importance of both as virulence determinants among egc superantigens.

Enterotoxin Gene Cluster-Encoded SEI and SElN from Staphylococcus aureus Isolates are Crucial for the Induction of Human Blood Cell Proliferation and Pathogenicity in Rabbits

PubMed Central

Roetzer, Andreas; Gruener, Corina S.; Haller, Guenter; Beyerly, John; Model, Nina; Eibl, Martha M.

2016-01-01

Among the toxin family of bacterial superantigens, the six members of the enterotoxin gene cluster (egc) seem to have unusual characteristics. They are present in the majority of Staphylococcus aureus strains, but their role in disease remains uncertain. We assessed secretion levels, immunogenicity, and toxicity of native and recombinant egc proteins. After having developed enzyme-linked immunosorbent assays, we found different quantities of egc proteins secreted by bacterial isolates. Supernatants induced proliferation of human peripheral blood mononuclear cells. However, purified recombinant egc proteins were shown to have differing superantigenicity potentials. Immunization with identical amounts of all members of egc, and the prominent toxic agent SEB, resulted in neutralizing antisera. Two egc proteins, SEI and SElN, were found to play a predominant role within the cluster. Both displayed the highest potential to activate blood cells, and were essential to be neutralized in supernatants. The application of a supernatant of a strain bearing only egc was sufficient for a lethal outcome in a rabbit model. Again, neutralization of SEI and SElN led to the survival of all tested animals. Finally, nanogram amounts of purified rSEI and rSElN led to lethality in vivo, pointing out the importance of both as virulence determinants among egc superantigens. PMID:27801832

T-cell epitope analysis using subtracted expression libraries (TEASEL): application to a 38-kDA autoantigen recognized by T cells from an insulin-dependent diabetic patient.

PubMed Central

Neophytou, P I; Roep, B O; Arden, S D; Muir, E M; Duinkerken, G; Kallan, A; de Vries, R R; Hutton, J C

1996-01-01

Studies on circulating T cells and antibodies in newly diagnosed type 1 diabetic patients and rodent models of autoimmune diabetes suggest that beta-cell membrane proteins of 38 kDa may be important molecular targets of autoimmune attack. Biochemical approaches to the isolation and identification of the 38-kDa autoantigen have been hampered by the restricted availability of islet tissue and the low abundance of the protein. A procedure of epitope analysis for CD4+ T cells using subtracted expression libraries (TEASEL) was developed and used to clone a 70-amino acid pancreatic beta-cell peptide incorporating an epitope recognized by a 38-kDa-reactive CD4+ T-cell clone (1C6) isolated from a human diabetic patient. The minimal epitope was mapped to a 10-amino acid synthetic peptide containing a DR1 consensus binding motif. Data base searches did not reveal the identity of the protein, though a weak homology to the bacterial superantigens SEA (Streptococcus pyogenes exotoxin A) and SEB (Staphylococcus aureus enterotoxin B) (23% identity) was evident. The TEASEL procedure might be used to identify epitopes of other autoantigens recognized by CD4+ T cells in diabetes as well as be more generally applicable to the study low-abundance autoantigens in other tissue-specific autoimmune diseases. PMID:8700877

Retrievals of Jovian Tropospheric Phosphine from Cassini/CIRS

NASA Technical Reports Server (NTRS)

Irwin, P. G. J.; Parrish, P.; Fouchet, T.; Calcutt, S. B.; Taylor, F. W.; Simon-Miller, A. A.; Nixon, C. A.

2004-01-01

On December 30th 2000, the Cassini-Huygens spacecraft reached the perijove milestone on its continuing journey to the Saturnian system. During an extended six-month encounter, the Composite Infrared Spectrometer (CIRS) returned spectra of the Jovian atmosphere, rings and satellites from 10-1400 cm(exp -1) (1000-7 microns) at a programmable spectral resolution of 0.5 to 15 cm(exp -1). The improved spectral resolution of CIRS over previous IR instrument-missions to Jupiter, the extended spectral range, and higher signal-to-noise performance provide significant advantages over previous data sets. CIRS global observations of the mid-infrared spectrum of Jupiter at medium resolution (2.5 cm(exp -1)) have been analysed both with a radiance differencing scheme and an optimal estimation retrieval model to retrieve the spatial variation of phosphine and ammonia fractional scale height in the troposphere between 60 deg S and 60 deg N at a spatial resolution of 6 deg. The ammonia fractional scale height appears to be high over the Equatorial Zone (EZ) but low over the North Equatorial Belt (NEB) and South Equatorial Belt (SEB) indicating rapid uplift or strong vertical mixing in the EZ. The abundance of phosphine shows a similar strong latitudinal variation which generally matches that of the ammonia fractional scale height. However while the ammonia fractional scale height distribution is to a first order symmetric in latitude, the phosphine distribution shows a North/South asymmetry at mid latitudes with higher amounts detected at 40 deg N than 40 deg S. In addition the data show that while the ammonia fractional scale height at this spatial resolution appears to be low over the Great Red Spot (GRS), indicating reduced vertical mixing above the approx. 500 mb level, the abundance of phosphine at deeper levels may be enhanced at the northern edge of the GRS indicating upwelling.

Ecosystem Evapotranspiration as a Response to Climate and Vegetation Coverage Changes in Northwest Yunnan, China

PubMed Central

Yang, Hao; Luo, Peng; Wang, Jun; Mou, Chengxiang; Mo, Li; Wang, Zhiyuan; Fu, Yao; Lin, Honghui; Yang, Yongping; Bhatta, Laxmi Dutt

2015-01-01

Climate and human-driven changes play an important role in regional droughts. Northwest Yunnan Province is a key region for biodiversity conservation in China, and it has experienced severe droughts since the beginning of this century; however, the extent of the contributions from climate and human-driven changes remains unclear. We calculated the ecosystem evapotranspiration (ET) and water yield (WY) of northwest Yunnan Province, China from 2001 to 2013 using meteorological and remote sensing observation data and a Surface Energy Balance System (SEBS) model. Multivariate regression analyses were used to differentiate the contribution of climate and vegetation coverage to ET. The results showed that the annual average vegetation coverage significantly increased over time with a mean of 0.69 in spite of the precipitation fluctuation. Afforestation/reforestation and other management efforts attributed to vegetation coverage increase in NW Yunnan. Both ET and WY considerably fluctuated with the climate factors, which ranged from 623.29 mm to 893.8 mm and –51.88 mm to 384.40 mm over the time period. Spatially, ET in the southeast of NW Yunnan (mainly in Lijiang) increased significantly, which was in line with the spatial trend of vegetation coverage. Multivariate linear regression analysis indicated that climatic factors accounted for 85.18% of the ET variation, while vegetation coverage explained 14.82%. On the other hand, precipitation accounted for 67.5% of the WY. We conclude that the continuous droughts in northwest Yunnan were primarily climatically driven; however, man-made land cover and vegetation changes also increased the vulnerability of local populations to drought. Because of the high proportion of the water yield consumed for subsistence and poor infrastructure for water management, local populations have been highly vulnerable to climate drought conditions. We suggest that conservation of native vegetation and development of water-conserving agricultural practices should be implemented as adaptive strategies to mitigate climate change. PMID:26237220

Ecosystem Evapotranspiration as a Response to Climate and Vegetation Coverage Changes in Northwest Yunnan, China.

PubMed

Yang, Hao; Luo, Peng; Wang, Jun; Mou, Chengxiang; Mo, Li; Wang, Zhiyuan; Fu, Yao; Lin, Honghui; Yang, Yongping; Bhatta, Laxmi Dutt

2015-01-01

Climate and human-driven changes play an important role in regional droughts. Northwest Yunnan Province is a key region for biodiversity conservation in China, and it has experienced severe droughts since the beginning of this century; however, the extent of the contributions from climate and human-driven changes remains unclear. We calculated the ecosystem evapotranspiration (ET) and water yield (WY) of northwest Yunnan Province, China from 2001 to 2013 using meteorological and remote sensing observation data and a Surface Energy Balance System (SEBS) model. Multivariate regression analyses were used to differentiate the contribution of climate and vegetation coverage to ET. The results showed that the annual average vegetation coverage significantly increased over time with a mean of 0.69 in spite of the precipitation fluctuation. Afforestation/reforestation and other management efforts attributed to vegetation coverage increase in NW Yunnan. Both ET and WY considerably fluctuated with the climate factors, which ranged from 623.29 mm to 893.8 mm and -51.88 mm to 384.40 mm over the time period. Spatially, ET in the southeast of NW Yunnan (mainly in Lijiang) increased significantly, which was in line with the spatial trend of vegetation coverage. Multivariate linear regression analysis indicated that climatic factors accounted for 85.18% of the ET variation, while vegetation coverage explained 14.82%. On the other hand, precipitation accounted for 67.5% of the WY. We conclude that the continuous droughts in northwest Yunnan were primarily climatically driven; however, man-made land cover and vegetation changes also increased the vulnerability of local populations to drought. Because of the high proportion of the water yield consumed for subsistence and poor infrastructure for water management, local populations have been highly vulnerable to climate drought conditions. We suggest that conservation of native vegetation and development of water-conserving agricultural practices should be implemented as adaptive strategies to mitigate climate change.

Characterization of the Staphylococcal enterotoxin A: Vβ receptor interaction using human receptor fragments engineered for high affinity.

PubMed

Sharma, P; Postel, S; Sundberg, E J; Kranz, D M

2013-12-01

Staphylococcal food poisoning is a gastrointestinal disorder caused by the consumption of food containing Staphylococcal enterotoxins. Staphylococcal enterotoxin A (SEA) is the most common enterotoxin recovered from food poisoning outbreaks in the USA. In addition to its enteric activity, SEA also acts as a potent superantigen through stimulation of T cells, although less is known about its interactions than the superantigens SEB, SEC and toxic shock syndrome toxin-1. To understand more about SEA:receptor interactions, and to develop toxin-detection systems for use in food testing, we engineered various SEA-binding receptor mutants. The extracellular domain of the receptor, a variable region of the beta chain (Vβ22) of the T-cell receptor, was engineered for stability as a soluble protein and for high affinity, using yeast-display technology. The highest affinity mutant was shown to bind SEA with a Kd value of 4 nM. This was a 25 000-fold improvement in affinity compared with the wild-type receptor, which bound to SEA with low affinity (Kd value of 100 µM), similar to other superantigen:Vβ interactions. The SEA:Vβ interface was centered around residues within the complementarity determining region 2 loop. The engineered receptor was specific for SEA, in that it did not bind to two other closely related enterotoxins SEE or SED, providing information on the SEA residues possibly involved in the interaction. The specificity and affinity of these high-affinity Vβ proteins also provide useful agents for the design of more sensitive and specific systems for SEA detection.

Characterization of the Staphylococcal enterotoxin A: Vβ receptor interaction using human receptor fragments engineered for high affinity

PubMed Central

Sharma, P.; Postel, S.; Sundberg, E.J.; Kranz, D.M.

2013-01-01

Staphylococcal food poisoning is a gastrointestinal disorder caused by the consumption of food containing Staphylococcal enterotoxins. Staphylococcal enterotoxin A (SEA) is the most common enterotoxin recovered from food poisoning outbreaks in the USA. In addition to its enteric activity, SEA also acts as a potent superantigen through stimulation of T cells, although less is known about its interactions than the superantigens SEB, SEC and toxic shock syndrome toxin-1. To understand more about SEA:receptor interactions, and to develop toxin-detection systems for use in food testing, we engineered various SEA-binding receptor mutants. The extracellular domain of the receptor, a variable region of the beta chain (Vβ22) of the T-cell receptor, was engineered for stability as a soluble protein and for high affinity, using yeast-display technology. The highest affinity mutant was shown to bind SEA with a Kd value of 4 nM. This was a 25 000-fold improvement in affinity compared with the wild-type receptor, which bound to SEA with low affinity (Kd value of 100 µM), similar to other superantigen:Vβ interactions. The SEA:Vβ interface was centered around residues within the complementarity determining region 2 loop. The engineered receptor was specific for SEA, in that it did not bind to two other closely related enterotoxins SEE or SED, providing information on the SEA residues possibly involved in the interaction. The specificity and affinity of these high-affinity Vβ proteins also provide useful agents for the design of more sensitive and specific systems for SEA detection. PMID:24167300

Development of bacterial display peptides for use in biosensing applications

NASA Astrophysics Data System (ADS)

Stratis-Cullum, Dimitra N.; Kogot, Joshua M.; Sellers, Michael S.; Hurley, Margaret M.; Sarkes, Deborah A.; Pennington, Joseph M.; Val-Addo, Irene; Adams, Bryn L.; Warner, Candice R.; Carney, James P.; Brown, Rebecca L.; Pellegrino, Paul M.

2012-06-01

Recent advances in synthetic library engineering continue to show promise for the rapid production of reagent technology in response to biological threats. A synthetic library of peptide mutants built off a bacterial host offers a convenient means to link the peptide sequence, (i.e., identity of individual library members) with the desired molecular recognition traits, but also allows for a relatively simple protocol, amenable to automation. An improved understanding of the mechanisms of recognition and control of synthetic reagent isolation and evolution remain critical to success. In this paper, we describe our approach to development of peptide affinity reagents based on peptide bacterial display technology with improved control of binding interactions for stringent evolution of reagent candidates, and tailored performance capabilities. There are four key elements to the peptide affinity reagent program including: (1) the diverse bacterial library technology, (2) advanced reagent screening amenable to laboratory automation and control, (3) iterative characterization and feedback on both affinity and specificity of the molecular interactions, and (3) integrated multiscale computational prescreening of candidate peptide ligands including in silico prediction of improved binding performance. Specific results on peptides binders to Protective Antigen (PA) protein of Bacillus anthracis and Staphylococcal Enterotoxin B (SEB) will be presented. Recent highlights of on cell vs. off-cell affinity behavior and correlation of the results with advanced docking simulations on the protein-peptide system(s) are included. The potential of this technology and approach to enable rapid development of a new affinity reagent with unprecedented speed (less than one week) would allow for rapid response to new and constantly emerging threats.

Prevalence of genes encoding extracellular virulence factors among meticillin-resistant Staphylococcus aureus isolates from the University Hospital, Olomouc, Czech Republic.

PubMed

Sauer, P; Síla, J; Stosová, T; Vecerová, R; Hejnar, P; Vágnerová, I; Kolár, M; Raclavsky, V; Petrzelová, J; Lovecková, Y; Koukalová, D

2008-04-01

A rather fast and complicated progression of an infection caused by some strains of Staphylococcus aureus could be associated with the expression and co-action of virulence factor complexes in these strains. This study screened the antibiotic susceptibility and prevalence of virulence markers in isolates of meticillin-resistant S. aureus (MRSA) obtained from patients hospitalized at the University Hospital in Olomouc, Czech Republic. A total of 100 isolates was screened for 13 genes encoding extracellular virulence determinants (tst, pvl, eta, etb, sea, seb, sec, sed, see, seg, seh, sei and sej) and for their distribution in sample types. Eighty-nine isolates were positive for at least one of the genes. Genes for etb, pvl, see and seh were not detected in any of the MRSA isolates. No statistically significant differences in the occurrence of the determinants studied among sample types were found.

Dietary n-3 PUFAs augment caspase 8 activation in Staphylococcal aureus enterotoxin B stimulated T-cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gill, R.

Epidemiological studies have linked consumption of n-3 PUFAs with a variety of beneficial health benefits, particularly with respect to putative anti-inflammatory effects. Unfortunately, many of these results remain somewhat controversial because in most instances there has not been a linkage to specific molecular mechanisms. For instance, dietary exposure to low levels of mercury has been shown to be damaging to neural development, but concomitant ingestion of n-3 PUFAs as occurs during consumption of fish, has been shown to counteract the detrimental effects. As the mechanisms mediating the neurotoxicity of environmental mercury are not fully delineated, it is difficult to conceptualizemore » a testable molecular mechanism explaining how n-3 PUFAs negate its neurotoxic effects. However, environmental exposure to mercury also has been linked to increased autoimmunity. By way of a molecular understanding of this immuno-toxic association, disruption of CD95 signaling is well established as a triggering factor for autoimmunity, and we have previously shown that environmentally relevant in vitro and dietary exposures to mercury interfere with CD95 signaling. In particular we have shown that activation of caspase 8, as well as downstream activation of caspase 3, in response to CD95 agonist stimulation is depressed by mercury. More recently we have shown in vitro that the n-3 PUFA docosahexaenoic acid counteracts the negative effect of mercury on CD95 signaling by restoring caspase activity. We hypothesized that concomitant ingestion of n-3 PUFAs with mercury might be protective from the immuno-toxic effects of mercury, as it is with mercury's neuro-toxic effects, and in the case of immuno-toxicity this would be related to restoration of CD95 signal strength. We now show that dietary ingestion of n-3 PUFAs generally promotes CD95 signaling by upregulating caspase 8 activation. Apart from accounting for the ability of n-3 PUFAs to specifically counteract autoimmune sequelae of mercury exposure, this novel finding for the first time suggests a testable molecular mechanism explaining the overall anti-inflammatory properties of n-3 PUFAs. - Highlights: • Dietary n-3 PUFAs counter Hg{sup 2+} immunotoxicity • Hg{sup 2+} interference with SEB-mediated signal transduction is ameliorated by n-3 PUFA rich diets. • Dietary n-3 PUFAs augment SEB-mediated activation of caspase 8 in vivo.« less

Molecular Characterization of Methicillin-Resistant Staphylococcus aureus from Outpatients in Northern Japan: Increasing Tendency of ST5/ST764 MRSA-IIa with Arginine Catabolic Mobile Element.

PubMed

Aung, Meiji Soe; Kawaguchiya, Mitsuyo; Urushibara, Noriko; Sumi, Ayako; Ito, Masahiko; Kudo, Kenji; Morimoto, Shigeo; Hosoya, Shino; Kobayashi, Nobumichi

2017-07-01

Arginine catabolic mobile element (ACME) is a genomic island of staphylococcus and is considered to confer enhanced ability to survive and growth on host bacterial cells. ACME has been typically identified in Panton-Valentine Leukocidin (PVL)-positive ST8 methicillin-resistant Staphylococcus aureus (MRSA) with SCCmec type IVa (USA300 clone), and it is also found in other lineages at low frequency. Prevalence and molecular characteristics of PVL + and/or ACME + MRSA were investigated for 624 clinical isolates collected from outpatients in northern Japan from 2013 to 2014. Both PVL genes and ACME type I were detected in nine isolates (1.4%), which were ST8-MRSA-SCCmec IVa/spa type t008/agr-I; whereas solely PVL genes were positive in two isolates, ST30-MRSA-SCCmec IV and ST59-MRSA-SCCmec V. ACME type II' (previously referred to as ACME ΔII) was detected in 36 isolates (5.8%) with SCCmec II and V (32 and 4 isolates, respectively), exhibiting an increased rate within SCCmec II-MRSA (7.1%) compared with our previous studies (0.86-4.5%, 2008-2011). ACME II'-positive MRSA strains were classified into ST5-SCCmec IIa/V or ST764-SCCmec IIa belonging to five different spa types, with t002 being dominant. They harbored mostly enterotoxin gene clusters (seg-sei-sem-sen-seo-seu) and some more enterotoxin genes (seb1, seb2, sec3, sel, sep), showing resistance to more antimicrobials than ST8-MRSA-SCCmec IVa. ACME-SCCmec composite island (CI) of the 36 ACME II'-positive MRSA was classified into five types (ii)-(vi), among which type (ii) (orfX-ΨSCC ΔJ1 SCCmec I -ACME II'-SCCmec II) was dominant and subdivided into the A3 variant and the less common A2 variant. CI types (v) and (vi) were considered novel genetic organizations having speG (acetyltransferase genes for polyamines) in inserted SCC4610/SCC266-like genetic elements. The present study revealed increased prevalence and genetic diversity of the ST5/ST764-MRSA-SCCmec II with ACME II' in northern Japan.

Sirolimus-eluting Biodegradable Poly-l-Lactic Acid Stent to Suppress Granulation Tissue Formation in the Rat Urethra.

PubMed

Kim, Kun Yung; Park, Jung-Hoon; Kim, Do Hoon; Tsauo, Jiaywei; Kim, Min Tae; Son, Woo-Chan; Kang, Sung-Gwon; Kim, Dong-Hyun; Song, Ho-Young

2018-01-01

Purpose To investigate the use of sirolimus-eluting biodegradable stents (SEBSs) to suppress granulation tissue formation after stent placement in a rat urethral model. Materials and Methods All experiments were approved by the animal research committee. A total of 36 male Sprague-Dawley rats were randomized into three equal groups after biodegradable stent placement. Group A received control biodegradable stents. Groups B and C received stents coated with 90 µg/cm 2 and 450 µg/cm 2 sirolimus, respectively. Six rats in each group were sacrificed after 4 weeks; the remaining rats were sacrificed after 12 weeks. The therapeutic effectiveness of SEBSs was assessed by comparing the results of retrograde urethrography and histologic examination. Analysis of variance with post hoc comparisons was used to evaluate statistical differences. Results SEBS placement was technically successful in all rats. Urethrographic and histologic examinations revealed significantly less granulation tissue formation at both time points in the rats receiving SEBSs (groups B and C) compared with those that received control stents (group A) (P < .05 for all). There were no significant differences in urethrographic and histologic findings between groups B and C (P > .05 for all). However, the mean number of epithelial layers in group B was higher than that in group C at 4 weeks after stent placement (P < .001). Apoptosis increased in group C compared with groups A and B (P < .05 for all). Conclusion The use of SEBSs suppressed granulation tissue formation secondary to stent placement in a rat urethral model; local therapy with SEBSs may be used to decrease stent-related granulation tissue formation. © RSNA, 2017.

Staphylococcal superantigen-specific IgE antibodies: degree of sensitization and association with severity of asthma.

PubMed

Elabras, José; Mello, Fernanda Carvalho de Queiroz; Lupi, Omar; Bica, Blanca Elena Rios Gomes; Papi, José Angelo de Souza; França, Alfeu Tavares

2016-01-01

To determine the presence of staphylococcal superantigen-specific IgE antibodies and degree of IgE-mediated sensitization, as well as whether or not those are associated with the severity of asthma in adult patients. This was a cross-sectional study involving outpatients with asthma under treatment at a tertiary care university hospital in the city of Rio de Janeiro, Brazil. Consecutive patients were divided into two groups according to the severity of asthma based on the Global Initiative for Asthma criteria: mild asthma (MA), comprising patients with mild intermittent or persistent asthma; and moderate or severe asthma (MSA). We determined the serum levels of staphylococcal toxin-specific IgE antibodies, comparing the results and performing a statistical analysis. The study included 142 patients: 72 in the MA group (median age = 46 years; 59 females) and 70 in the MSA group (median age = 56 years; 60 females). In the sample as a whole, 62 patients (43.7%) presented positive results for staphylococcal toxin-specific IgE antibodies: staphylococcal enterotoxin A (SEA), in 29 (20.4%); SEB, in 35 (24.6%); SEC, in 33 (23.2%); and toxic shock syndrome toxin (TSST), in 45 (31.7%). The mean serum levels of IgE antibodies to SEA, SEB, SEC, and TSST were 0.96 U/L, 1.09 U/L, 1.21 U/L, and 1.18 U/L, respectively. There were no statistically significant differences between the two groups in terms of the qualitative or quantitative results. Serum IgE antibodies to SEA, SEB, SEC, and TSST were detected in 43.7% of the patients in our sample. However, neither the qualitative nor quantitative results showed a statistically significant association with the clinical severity of asthma. Determinar a presença de anticorpos IgE específicos para superantígenos estafilocócicos e o grau de sensibilização mediada por esses, assim como se esses estão associados à gravidade da asma em pacientes adultos. Estudo transversal incluindo asmáticos adultos em acompanhamento ambulatorial em um hospital universitário terciário no Rio de Janeiro (RJ). Os pacientes foram alocados consecutivamente em dois grupos de gravidade da asma segundo critérios da Global Initiative for Asthma: asma leve (AL), com asmáticos leves intermitentes ou persistentes, e asma moderada ou grave (AMG). Foram determinados os níveis séricos de anticorpos IgE antitoxinas estafilocócicas, e os resultados foram comparados por análise estatística. Foram incluídos 142 pacientes no estudo: 72 no grupo AL (mediana de idade = 46 anos; 59 do sexo feminino) e 70 do grupo AMG (mediana de idade = 56 anos; 60 do sexo feminino). Na amostra geral, 62 pacientes (43,7%) apresentaram resultados positivos para dosagens de anticorpos IgE antitoxinas estafilocócicas: enterotoxina (TX) A, em 29 (20,4%); TXB, em 35 (24,6%); TXC, em 33 (23,2%); e toxic shock syndrome toxin (TSST), em 45 (31,7%). As médias das dosagens séricas de anticorpos IgE específicos anti-TXA, TXB, TXC e TSST foram, respectivamente, de 0,96 U/l, 1,09 U/l, 1,21 U/l, e 1,18 U/l. Não houve diferença estatisticamente significativa dos resultados qualitativos ou quantitativos entre os grupos. A presença de anticorpos IgE séricos anti-TXA, TXB, TXC e TSST, foi detectada em 43,7% nessa amostra de pacientes, mas não houve associação estatisticamente significativa entre seus resultados qualitativos ou quantitativos e gravidade clínica da asma.

Quantifying green water flows for improved Integrated Land and Water Resource Management under the National Water Act of South Africa: A review on hydrological research in South Africa.

NASA Astrophysics Data System (ADS)

Jarmain, C.; Everson, C. S.; Gush, M. B.; Clulow, A. D.

2009-09-01

The contribution of hydrological research in South Africa in quantifying green water flows for improved Integrated Land and Water Resources Management is reviewed. Green water refers to water losses from land surfaces through transpiration (seen as a productive use) and evaporation from bare soil (seen as a non-productive use). In contrast, blue water flows refer to streamflow (surface water) and groundwater / aquifer recharge. Over the past 20 years, a number of methods have been used to quantify the green water and blue water flows. These include micrometeorological techniques (e.g. Bowen ratio energy balance, eddy covariance, surface renewal, scintillometry, lysimetry), field scale models (e.g. SWB, SWAP), catchment scale hydrological models (e.g. ACRU, SWAT) and more recently remote sensing based models (e.g. SEBAL, SEBS). The National Water Act of South Africa of 1998 requires that water resources are managed, protected and used (developed, conserved and controlled) in an equitable way which is beneficial to the public. The quantification of green water flows in catchments under different land uses has been pivotal in (a) regulating streamflow reduction activities (e.g. forestry) and the management of alien invasive plants, (b) protecting riparian and wetland areas through the provision of an ecological reserve, (c) assessing and improving the water use efficiency of irrigated pastures, fruit tree orchards and vineyards, (d) quantifying the potential impact of future land uses like bio-fuels (e.g. Jatropha) on water resources, (e) quantifying water losses from open water bodies, and (f) investigating "biological” mitigation measures to reduce the impact of polluted water resources as a result of various industries (e.g. mining). This paper therefore captures the evolution of measurement techniques applied across South Africa, the impact these results have had on water use and water use efficiency and the extent to which it supported the National Water Act of South Africa.

Teleconsultation: The use of technology to improve evidence-based practices in rural communities.

PubMed

Bice-Urbach, Brittany J; Kratochwill, Thomas R

2016-06-01

Problem-solving consultation in schools has been found to be an effective method of service delivery to support teachers who are struggling to address student social-emotional behavioral (SEB) concerns. Despite its benefits, a number of barriers (e.g., lack of time and limited access to trained professionals) restrict the use of consultation within schools, especially in rural settings. The purpose of the study was to examine the impact of teleconsultation designed to improve behavior support to students living in rural communities. Both student outcomes and teacher perceptions were evaluated. Results indicated that (a) student disruptive behaviors improved through the implementation of an individualized behavior support plan developed through teleconsultation, and (b) teachers found the teleconsultation experience acceptable and feasible. As the demands placed on psychologists and the quality of videoconferencing continue to increase, teleconsultation is becoming a viable option for service delivery within rural school settings. Copyright © 2016 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Annotated catalog and bibliography of the cyclocephaline scarab beetles (Coleoptera, Scarabaeidae, Dynastinae, Cyclocephalini).

PubMed

Moore, Matthew R; Cave, Ronald D; Branham, Marc A

2018-01-01

Cyclocephaline scarab beetles represent the second largest tribe of the subfamily Dynastinae, and the group includes the most speciose genus of dynastines, Cyclocephala . The period following publication of Sebő Endrődi's The Dynastinae of the World has seen a huge increase in research interest on cyclocephalines, and much of this research has not been synthesized. The objective of this catalog and bibliography is to compile an exhaustive list of taxa in Cyclocephalini. This paper provides an updated foundation for understanding the taxonomy and classification of 14 genera and over 500 species in the tribe. It discusses the history of cataloging dynastine species, clarifies issues surrounding the neotype designations in Endrődi's revision of Cyclocephalini, synthesizes all published distribution data for cyclocephaline species, and increases accessibility to the voluminous literature on the group by providing an easily searchable bibliography for each species. We propose the nomen novum Cyclocephala rogerpauli , new replacement name , for C. nigra Dechambre.

A proteomics assay to detect eight CBRN-relevant toxins in food.

PubMed

Gilquin, Benoit; Jaquinod, Michel; Louwagie, Mathilde; Kieffer-Jaquinod, Sylvie; Kraut, Alexandra; Ferro, Myriam; Becher, François; Brun, Virginie

2017-01-01

A proteomics assay was set up to analyze food substrates for eight toxins of the CBRN (chemical, biological, radiological and nuclear) threat, namely ricin, Clostridium perfringens epsilon toxin (ETX), Staphylococcus aureus enterotoxins (SEA, SEB and SED), shigatoxins from Shigella dysenteriae and entero-hemorragic Escherichia coli strains (STX1 and STX2) and Campylobacter jejuni cytolethal distending toxin (CDT). The assay developed was based on an antibody-free sample preparation followed by bottom-up LC-MS/MS analysis operated in targeted mode. Highly specific detection and absolute quantification were obtained using isotopically labeled proteins (PSAQ standards) spiked into the food matrix. The sensitivity of the assay for the eight toxins was lower than the oral LD50 which would likely be used in a criminal contamination of food supply. This assay should be useful in monitoring biological threats. In the public-health domain, it opens the way for multiplex investigation of food-borne toxins using targeted LC-MS/MS. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Radiation Characterization of Commercial GaN Devices

NASA Technical Reports Server (NTRS)

Harris, Richard D.; Scheick, Leif Z.; Hoffman, James P.; Thrivikraman, Tushar; Jenabi, Masud; Gim, Yonggyu; Miyahira, Tetsuo

2011-01-01

Radiative feedback from primordial protostars and final mass of the first star Commercially available devices fabricated from GaN are beginning to appear from a number of different suppliers. Based on previous materials and prototype device studies, it is expected that these commercial devices will be quite tolerant to the types of radiation encountered in space. This expectation needs to be verified and the study described herein was undertaken for that purpose. All of the parts discussed in this report are readily available commercially. The parts chosen for study are all targeted for RF applications. Three different studies were performed: 1) a preliminary DDD/TID test of a variety of part types was performed by irradiating with 50 MeV protons, 2) a detailed DDD/TID study of one particular part type was performed by irradiating with 50 MeV protons, and 3) a SEB/SEGR test was performed on a variety of part types by irradiating with heavy ions. No significant degradation was observed in the tests performed in this study.

Annotated catalog and bibliography of the cyclocephaline scarab beetles (Coleoptera, Scarabaeidae, Dynastinae, Cyclocephalini)

PubMed Central

Moore, Matthew R.; Cave, Ronald D.; Branham, Marc A.

2018-01-01

Abstract Cyclocephaline scarab beetles represent the second largest tribe of the subfamily Dynastinae, and the group includes the most speciose genus of dynastines, Cyclocephala. The period following publication of Sebő Endrődi’s The Dynastinae of the World has seen a huge increase in research interest on cyclocephalines, and much of this research has not been synthesized. The objective of this catalog and bibliography is to compile an exhaustive list of taxa in Cyclocephalini. This paper provides an updated foundation for understanding the taxonomy and classification of 14 genera and over 500 species in the tribe. It discusses the history of cataloging dynastine species, clarifies issues surrounding the neotype designations in Endrődi’s revision of Cyclocephalini, synthesizes all published distribution data for cyclocephaline species, and increases accessibility to the voluminous literature on the group by providing an easily searchable bibliography for each species. We propose the nomen novum Cyclocephala rogerpauli, new replacement name, for C. nigra Dechambre. PMID:29670449

Survey and properties of Staphylococcus aureus isolated from Japanese-style desserts.

PubMed

Shimamura, Yuko; Kidokoro, Shiho; Murata, Masatsune

2006-07-01

We surveyed the contamination of 315 Japanese- and western-style desserts and 247 human hands by Staphylococcus aureus and other staphylococcal bacteria. The most frequently isolated staphylococcal bacterium was S. warneri, followed by S. aureus. Only 1.9% of western-style desserts were contaminated by S. aureus strains, while 19.4% and 13.0% of Japanese-style desserts and human hands respectively were contaminated. Ninety-four isolates of S. aureus were characterized as to their biological properties and enterotoxigenicity. Although staphylococcal enterotoxins (SEs) were detected by enzyme-linked immunosorbent assay in the cultured broth of all S. aureus isolates, the reversed passive latex agglutination method and the polymerase chain reaction showed only 39 (41.5%) and 40 (42.6%) samples respectively as SE-positive. The predominant type of SE was SEB (67.5%), and eight strains produced SEA. None of the S. aureus strains had penicillin-binding protein 2', showing that methicillin-resistant S. aureus was not present in the samples.

Understanding the climate-included variations in the seasonal water demands of irrigated crops in Northern India

NASA Astrophysics Data System (ADS)

Bhattarai, N.; Jain, M.

2016-12-01

Expected changes in temperature and precipitation patterns in the rice-wheat belt of Northern India have implications for balancing crop water demand and available water resources. Because the impacts of water scarcity and reduced crop production are realized at a local scale, water-saving interventions are most effective when implemented locally. However, a paucity of fine-scale studies on the relationship between variations in climate and crop water demand has limited our ability to effectively implement such interventions. In an effort to better understand the responses of irrigated crops to changing climate in Northern India at finer-scales, we propose a remote sensing based semi-empirical approach. First, we employ a multi-model surface energy balance (SEB) approach to map seasonal evapotranspiration (ET)/water use (1995-2015) at 30 to 100 m resolution from space and investigate how seasonal and inter-annual variations in temperature and precipitation are associated with regional surface-energy budgets. Second, using remote estimates of ET and other biophysical variables, such as vegetation indices, land surface temperature, and albedo, we will explain the possible relationships between climate change and seasonal water demands of crops. Our estimates of high/moderate resolution (30 to 100 m) seasonal ET maps can make clear distinctions between impacts of climate variations on crop water demand at field, plot, and regional scales in Northern India. Finally, by improving our ability to identify targeted area for water-saving interventions, this study supports agricultural resiliency of Northern India in the face of climate change.

Compendium of Current Single Event Effects for Candidate Spacecraft Electronics for NASA

NASA Technical Reports Server (NTRS)

O'Bryan, Martha V.; Label, Kenneth A.; Chen, Dakai; Campola, Michael J.; Casey, Megan C.; Lauenstein, Jean-Marie; Pellish, Jonathan A.; Ladbury, Raymond L.; Berg, Melanie D.

2015-01-01

NASA spacecraft are subjected to a harsh space environment that includes exposure to various types of ionizing radiation. The performance of electronic devices in a space radiation environment are often limited by their susceptibility to single event effects (SEE). Ground-based testing is used to evaluate candidate spacecraft electronics to determine risk to spaceflight applications. Interpreting the results of radiation testing of complex devices is and adequate understanding of the test condition is critical. Studies discussed herein were undertaken to establish the application-specific sensitivities of candidate spacecraft and emerging electronic devices to single-event upset (SEU), single-event latchup (SEL), single-event gate rupture (SEGR), single-event burnout (SEB), and single-event transient (SET). For total ionizing dose (TID) and displacement damage dose (DDD) results, see a companion paper submitted to the 2015 Institute of Electrical and Electronics Engineers (IEEE) Nuclear and Space Radiation Effects Conference (NSREC) Radiation Effects Data Workshop (REDW) entitled "compendium of Current Total Ionizing Dose and Displacement Damage for Candidate Spacecraft Electronics for NASA by M. Campola, et al.

Magnetic anomalies in Fe-doped NiO nanoparticle

NASA Astrophysics Data System (ADS)

Pradeep, R.; Gandhi, A. C.; Tejabhiram, Y.; Mathar Sahib, I. K. Md; Shimura, Y.; Karmakar, L.; Das, D.; Wu, Sheng Yun; Hayakawa, Y.

2017-09-01

Undoped and iron-doped NiO nanoparticle were synthesized by standard hydrothermal method. A detailed study is carried out on the effect of dopant concentration on morphology, structural, resonance and magnetic properties of NiO nanoparticle by varying the Fe concentration from 0.01 to 0.10 M. The synchrotron-x-ray diffraction confirmed that no secondary phase was observed other than NiO. The x-ray photoelectron spectroscopy studies revealed that, Fe was primarily in the trivalent state, replacing the Ni2+ ion inside the octahedral crystal site of NiO. The Electron paramagnetic studies revealed the ferromagnetic cluster formation at high doping concentration (5 and 10%). The ZFC-FC curves displayed an average blocking temperature around 180 K due to particle size distribution. The anomalous behaviour of spontaneous exchange bias (H SEB) and magnetic remanence (M r) for all Fe-doped samples observed at 5 K showed an increase (0.1316-0.1384 emu g-1) in the moment of frozen spin (M p) as the dopant concentration increased. The role of frozen spin moment in spontaneous exchange bias behaviour was discussed.

Comparative Stress Corrosion Cracking and General Corrosion Resistance of Annealed and Hardened 440 C Stainless Steel - New Techniques in Stress Corrosion Testing

NASA Technical Reports Server (NTRS)

Mendreck, M. J.; Hurless, B. E.; Torres, P. D.; Danford, M. D.

1998-01-01

The corrosion and stress corrosion cracking (SCC) characteristics of annealed and hardened 440C stainless steel were evaluated in high humidity and 3.5-percent NaCl solution. Corrosion testing consisted of an evaluation of flat plates, with and without grease, in high humidity, as well as electrochemical testing in 3.5-percent NaCl. Stress corrosion testing consisted of conventional, constant strain, smooth bar testing in high humidity in addition to two relatively new techniques under evaluation at MSFC. These techniques involve either incremental or constant rate increases in the load applied to a precracked SE(B) specimen, monitoring the crack-opening-displacement response for indications of crack growth. The electrochemical corrosion testing demonstrated an order of magnitude greater general corrosion rate in the annealed 440C. All techniques for stress corrosion testing showed substantially better SCC resistance in the annealed material. The efficacy of the new techniques for stress corrosion testing was demonstrated both by the savings in time and the ability to better quantify SCC data.

Measuring NH3 and other molecular abundance profiles from 5 microns ground-based spectroscopy in support of JUNO investigations

NASA Astrophysics Data System (ADS)

Blain, Doriann; Fouchet, Thierry; Greathouse, Thomas K.; Bézard, Bruno; Encrenaz, Therese; Lacy, John H.; Drossart, Pierre

2017-10-01

We report on results of an observational campaign to support the Juno mission. At the beginning of 2016, using TEXES (Texas Echelon cross-dispersed Echelle Spectrograph), mounted on the NASA Infrared Telescope Facility (IRTF), we obtained data cubes of Jupiter in the 1930--1943 cm-1 and 2135--2153 cm-1 spectral ranges (around 5 μm), which probe the atmosphere in the 1--4 bar region, with a spectral resolution of ≈0.3 cm-1 (R≈7000) and an angular resolution of ≈1.5''.This dataset is analyzed by a code that combines a line-by-line radiative transfer model with a non-linear optimal estimation inversion method. The inversion retrieves the abundance profiles of NH3 and PH3, which are the main conbtributors at these wavelengths, as well as the cloud transmittance. This retrieval is performed over more than one thousand pixels of our data cubes, producing effective maps of the disk, where all the major belts are visible (NEB, SEB, NTB, STB, NNTB and SSTB).We will present notably our retrieved NH3 abundance maps which can be compared with the unexpected latitudinal distribution observed by Juno's MWR (Bolton et al., 2017 and Li et al. 2017), as well as our other species retrieved abundance maps and discuss on their significance for the understanding of Jupiter's atmospheric dynamics.References:Bolton, S., et al. (2017), Jupiter’s interior and deep atmosphere: The first close polar pass with the Juno spacecraft, Science, doi:10.1126/science.aal2108, in press.Li, C., A. P. Ingersoll, S. Ewald, F. Oyafuso, and M. Janssen (2017), Jupiter’s global ammonia distribution from inversion of Juno Microwave Radiometer observations, Geophys. Res. Lett., doi:10.1002/2017GL073159, in press.

Enterotoxin-Encoding Genes in Staphylococcus spp. from Food Handlers in a University Restaurant.

PubMed

da Silva, Sabina Dos Santos Paulino; Cidral, Thiago André; Soares, Maria José dos Santos; de Melo, Maria Celeste Nunes

2015-11-01

Food handlers carrying enterotoxin-producing Staphylococcus are a potential source of food poisoning. The aim of this study was to analyze genes encoding enterotoxins in coagulase-positive Staphylococcus (CoPS) and coagulase-negative Staphylococcus (CoNS) isolated from the anterior nostrils and hands of food handlers at a university restaurant in the city of Natal, Northeast Brazil. Thirty food handlers were screened for the study. The isolates were subjected to Gram staining, a bacitracin sensitivity test, mannitol fermentation, and catalase and coagulase tests. CoNS and CoPS strains were subsequently identified by a Vitek 2 System (BioMerieux, France) and various biochemical tests. Polymerase chain reaction was used to detect genes for enterotoxins A, B, C, D, E, G, H, and I (sea, seb, sec, sed, see, seg, seh, and sei) and a disc-diffusion method was used to determine susceptibility to several classes of antimicrobials. All food handlers presented staphylococci on their hands and/or noses. The study found 58 Staphylococcus spp., of which 20.7% were CoPS and 79.3% were CoNS. S. epidermidis was the most prevalent species. Twenty-nine staphylococci (50%) were positive for one or more enterotoxin genes, and the most prevalent genes were seg and sei, each with a frequency of 29.3%. Indeed, CoNS encoded a high percentage of enterotoxin genes (43.5%). However, S. aureus encoded even more enterotoxin genes (75%). Most isolates showed sensitivity to the antibiotics used for testing, except for penicillin (only 35% sensitive). The results from this study reinforce that coagulase-negative as well as coagulase-positive staphylococci isolated from food handlers are capable of genotypic enterotoxigenicity.

Building a framework for theory-based ethnographies for studying intergenerational family food practices.

PubMed

Visser, Sanne Siete; Hutter, Inge; Haisma, Hinke

2016-02-01

The growing rates of (childhood) obesity worldwide are a source concern for health professionals, policy-makers, and researchers. The increasing prevalence of associated diseases-such as diabetes, cardiovascular diseases, and psychological problems-shows the impact of obesity on people's health, already from a young age. In turn, these problems have obvious consequences for the health care system, including higher costs. However, the treatment of obesity has proven to be difficult, which makes prevention an important goal. In this study, we focus on food practices, one of the determinants of obesity. In recent years, it has become increasingly clear that interventions designed to encourage healthy eating of children and their families are not having the desired impact, especially among groups with a lower socioeconomic background (SEB). To understand why interventions fail to have an impact, we need to study the embedded social and cultural constructions of families. We argue that we need more than just decision-making theories to understand this cultural embeddedness, and to determine what cultural and social factors influence the decision-making process. By allowing families to explain their cultural background, their capabilities, and their opportunities, we will gain new insights into how families choose what they eat from a complex set of food choices. We have thus chosen to build a framework based on Sen's capability approach and the theory of cultural schemas. This framework, together with a holistic ethnographic research approach, can help us better understand what drives the food choices made in families. The framework is built to serve as a starting point for ethnographic research on food choice in families, and could contribute to the development of interventions that are embedded in the cultural realities of the targeted groups. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Considerations in detecting CDC select agents under field conditions

NASA Astrophysics Data System (ADS)

Spinelli, Charles; Soelberg, Scott; Swanson, Nathaneal; Furlong, Clement; Baker, Paul

2008-04-01

Surface Plasmon Resonance (SPR) has become a widely accepted technique for real-time detection of interactions between receptor molecules and ligands. Antibody may serve as receptor and can be attached to the gold surface of the SPR device, while candidate analyte fluids contact the detecting antibody. Minute, but detectable, changes in refractive indices (RI) indicate that analyte has bound to the antibody. A decade ago, an inexpensive, robust, miniature and fully integrated SPR chip, called SPREETA, was developed. University of Washington (UW) researchers subsequently developed a portable, temperature-regulated instrument, called SPIRIT, to simultaneously use eight of these three-channel SPREETA chips. A SPIRIT prototype instrument was tested in the field, coupled to a remote reporting system on a surrogate unmanned aerial vehicle (UAV). Two target protein analytes were released sequentially as aerosols with low analyte concentration during each of three flights and were successfully detected and verified. Laboratory experimentation with a more advanced SPIRIT instrument demonstrated detection of very low levels of several select biological agents that might be employed by bioterrorists. Agent detection under field-like conditions is more challenging, especially as analyte concentrations are reduced and complex matricies are introduced. Two different sample preconditioning protocols have been developed for select agents in complex matrices. Use of these preconditioning techniques has allowed laboratory detection in spiked heavy mud of Francisella tularensis at 10 3 CFU/ml, Bacillus anthracis spores at 10 3 CFU/ml, Staphylococcal enterotoxin B (SEB) at 1 ng/ml, and Vaccinia virus (a smallpox simulant) at 10 5 PFU/ml. Ongoing experiments are aimed at simultaneous detection of multiple agents in spiked heavy mud, using a multiplex preconditioning protocol.

Detection of target staphylococcal enterotoxin B antigen in orange juice and popular carbonated beverages using antibody-dependent antigen-capture assays.

PubMed

Principato, MaryAnn; Njoroge, Joyce M; Perlloni, Andrei; O' Donnell, Michael; Boyle, Thomas; Jones, Robert L

2010-10-01

There is a critical need for qualitative and quantitative methodologies that provide the rapid and accurate detection of food contaminants in complex food matrices. However, the sensitivity of the assay can be affected when antigen-capture is applied to certain foods or beverages that are extremely acidic. This study was undertaken to assess the effects of orange juice and popular carbonated soft drink upon the fidelity of antibody-based antigen-capture assays and to develop simple approaches that could rescue assay performance without the introduction of additional or extensive extraction procedures. We examined the effects of orange juice and a variety of popular carbonated soft drink beverages upon a quantitative Interleukin-2 (IL-2) enzyme-linked immunosorbent assay (ELISA) assay system and a lateral flow device (LFD) adapted for the detection of staphylococcal enterotoxin B (SEB) in foods. Alterations in the performance and sensitivity of the assay were directly attributable to the food matrix, and alterations in pH were especially critical. The results demonstrate that approaches such as an alteration of pH and the use of milk as a blocking agent, either singly or in combination, will partially rescue ELISA performance. The same approaches permit lateral flow to efficiently detect antigen. Practical Application: The authors present ways to rescue an ELISA assay compromised by acidity in beverages and show that either the alteration of pH, or the use of milk as a blocking agent are not always capable of restoring the assay to its intended efficiency. However, the same methods, when employed with lateral flow technology, are rapid and extremely successful.

Genetic shifts in methicillin-resistant Staphylococcus aureus epidemic clones and toxin gene profiles in Japan: comparative analysis among pre-epidemic, epidemic and post-epidemic phases.

PubMed

Osaka, Shunsuke; Okuzumi, Katsuko; Koide, Shota; Tamai, Kiyoko; Sato, Tomoaki; Tanimoto, Koichi; Tomita, Haruyoshi; Suzuki, Masahiro; Nagano, Yukiko; Shibayama, Keigo; Arakawa, Yoshichika; Nagano, Noriyuki

2018-03-01

The decline in methicillin-resistant Staphylococcus aureus (MRSA) isolation rates has become a general observation worldwide, including Japan. We hypothesized that some genetic shift in MRSA might cause this phenomenon, and therefore we investigated the genetic profiles among MRSA clinical isolates obtained from three different epidemic phases in Japan. A total of 353 MRSA isolates were selected from 202 medical facilities in 1990 (pre-epidemic phase), 2004 (epidemic phase) and 2016 (post-epidemic phase). Molecular typing was performed by PCR detection of 22 genes using the polymerase chain reaction (PCR)-based ORF typing (POT) system, including an additional eight genes including small genomic islets and seven toxin genes. Isolates with a POT1 of score 93, identified as presumed clonal complex (pCC)5-staphylococcal cassette chromosome mec (SCCmec) type II including ST5-SCCmec type II New York/Japan clone, represented the major epidemic MRSA lineage in 1990 and 2004. In 2016, however, a marked decrease in isolates with a POT1 score of 93, along with changes in the epidemiology of toxin genes carried, was noted, where the carriers of tst genes including the tst-sec combination were markedly reduced, and those possessing the seb gene alone were markedly increased. Rather, isolates with a POT1 score of 106, including pCC1 or pCC8 among the isolates with SCCmec type IV, which often links to community-associated MRSA, were predominant. Interestingly, the pCC1 and pCC8 lineages were related to sea and tst-sec carriage, respectively. Over time, a transition in MRSA genetic profiles from a POT1 score of 93 in 1990 and 2004 to 106 in 2014 was found in Japan.

Recent development in low-constraint fracture toughness testing for structural integrity assessment of pipelines

NASA Astrophysics Data System (ADS)

Kang, Jidong; Gianetto, James A.; Tyson, William R.

2018-03-01

Fracture toughness measurement is an integral part of structural integrity assessment of pipelines. Traditionally, a single-edge-notched bend (SE(B)) specimen with a deep crack is recommended in many existing pipeline structural integrity assessment procedures. Such a test provides high constraint and therefore conservative fracture toughness results. However, for girth welds in service, defects are usually subjected to primarily tensile loading where the constraint is usually much lower than in the three-point bend case. Moreover, there is increasing use of strain-based design of pipelines that allows applied strains above yield. Low-constraint toughness tests represent more realistic loading conditions for girth weld defects, and the corresponding increased toughness can minimize unnecessary conservatism in assessments. In this review, we present recent developments in low-constraint fracture toughness testing, specifically using single-edgenotched tension specimens, SENT or SE(T). We focus our review on the test procedure development and automation, round-robin test results and some common concerns such as the effect of crack tip, crack size monitoring techniques, and testing at low temperatures. Examples are also given of the integration of fracture toughness data from SE(T) tests into structural integrity assessment.

Compendium of Single Event Effects, Total Ionizing Dose, and Displacement Damage for Candidate Spacecraft Electronics for NASA

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; OBryan, Martha V.; Chen, Dakai; Campola, Michael J.; Casey, Megan C.; Pellish, Jonathan A.; Lauenstein, Jean-Marie; Wilcox, Edward P.; Topper, Alyson D.; Ladbury, Raymond L.;

The abundance and distribution of water vapor in Jupiter's atmosphere

NASA Technical Reports Server (NTRS)

Bjoraker, Gordon L.; Larson, Harold P.; Kunde, Virgil G.

1986-01-01

The atmospheric transmission window between 1800 and 2250 cm(-1) in Jupiter's atmosphere was observed from the Kuiper Airborne Observatory (KAO) and by the infrared spectrometer (IRIS) on Voyager. The vertical distribution of H2O was derived for the 1 to 6 bar portion of Jupiter's troposphere. The spatial variation of H2O was measured using IRIS spectra of the Hot Spots in the North and South Equatorial Belts, the Equatorial Zone, and for an average of the North and South Tropical Zones. The H2O column abundance above the 4 bar level is the same in the zones as in the SEB Hot Spots, about 20 cm-amagat. The NEB Hot Spots are desiccated by a factor of 3 with respect to the rest of Jupiter. For an average between -40 to 40 deg latitude, the H2O mole fraction, qH2O, is saturated for P less than 2 bars, qH2O = 4x10 to the -6 in the 2 to 4 bar range and it increases to 3x10 to the -5 at 6 bars. A similar vertical profile applies to the spatially resolved zone and belt spectra, except that H2O falls off more rapidly at P less than 4 bars in the NEB Hot Spots. The massive H2O cloud at 5 bars, T = 273 K, proposed in solar composition models, is inconsistent with the observations. Instead, a thin H2O ice cloud would form at 2 bars, T = 200 K. The O/H ratio in Jupiter, inferred from H2O measurements in both belts and zones at 6 bars, is depleted by a factor of 50 with respect to the Sun. The implications for the origin of Jupiter of globally depleted O/H, but enhanced C/H and N/H, are discussed.

Safety Evaluation of the Coagulase-Negative Staphylococci Microbiota of Salami: Superantigenic Toxin Production and Antimicrobial Resistance

PubMed Central

Soares Casaes Nunes, Raquel; Mere Del Aguila, Eduardo; Paschoalin, Vânia Margaret Flosi

2015-01-01

The risks of contracting staphylococci food poisoning by the consumption of improperly manufactured salami and the possibility of this food being reservoirs for antibiotic resistance were evaluated. Nineteen coagulase-negative staphylococci (CNS) strains were found in commercial and artisanal salami. The species in commercial salami were S. saprophyticus, S. sciuri, S. xylosus, and S. carnosus. Artisanal salami showed S. succinus, S. epidermidis, and S. hominis but no S. carnosus. Phylogenetic analyses grouped the strains into three major staphylococcal species groups, comprised of 4 refined clusters with similarities superior to 90%. Fifteen strains harbored multiple enterotoxin genes, with high incidence of seb/sec and sea, 57% and 50%, respectively, intermediate incidence of sed/seh/selm and sei/seln/tst-H, 33% and 27%, correspondingly, and low incidence of see/selj/selo and seg, of respectively 13% and 1%. Real time RT-PCR and enzyme-linked-immunosorbent assays confirmed the enterotoxigenicity of the strains, which expressed and produced enterotoxins in vitro. The CNS strains showed multiresistance to several antimicrobials of therapeutic importance in both human and veterinarian medicine, such as β-lactams, vancomycin, and linezolid. The effective control of undue staphylococci in fermented meat products should be adopted to prevent or limit the risk of food poisoning and the spread of antimicrobial-resistant strains. PMID:26697486

Water quality monitoring using an automated portable fiber optic biosensor: RAPTOR

NASA Astrophysics Data System (ADS)

Anderson, George P.; Rowe-Taitt, Chris A.

2001-03-01

The RAPTOR is a portable, automated biosensor capable of performing rapid, ten-minute assays on a sample for four target analytes simultaneously. Samples are analyzed using a fluorescent sandwich immunoassay on the surface of short polystyrene optical probes with capture antibody adsorbed to the probe surface. Target analytes bound to the fiber by capture antibodies are detected with fluorescently labeled tracer antibodies, which are held in a separate reservoir. Since target recognition is a two-step process, selectivity is enhanced, and the optical probes can be reused up to forty times, or until a positive result is obtained. This greatly reduces the logistical burden for field operations. Numerous assays for toxins, such as SEB and ricin, and bacteria, such as Bacillus anthracis and Francisella tularensis, have been developed for the RAPTOR. An assay of particular interest for water quality monitoring and the screening of fruits and vegetables is detection of Giardia cysts. Giardia lamblia is a parasitic protozoan common in the developing world that causes severe intestinal infections. Thus, a simple field assay for screening water supplies would be highly useful. Such an assay has been developed using the RAPTOR. The detection limit for Giardia cysts was 5x104/ml for a 10-minute assay.

Identification of Infantile Diarrhea Caused by Breast Milk-Transmitted Staphylococcus aureus Infection.

PubMed

Chen, Zhong; Pan, Wei-Guang; Xian, Wei-Yi; Cheng, Hang; Zheng, Jin-Xin; Hu, Qing-Hua; Yu, Zhi-Jian; Deng, Qi-Wen

2016-10-01

Staphylococcus aureus is a well-known organism which is responsible for a variety of human infectious diseases including skin infections, pneumonia, bacteremia, and endocarditis. Few of the microorganisms can be transmitted from mother to the newborn or infant by milk breastfeeding. This study aims to identify transmission of S. aureus from healthy, lactating mothers to their infants by breastfeeding. Stool specimens of diarrheal infants and breast milk of their mother (totally three pairs) were collected and six Staphylococcus aureus isolates were cultured positively. Homology and molecular characters of isolated strains were tested using pulsed-field gel electrophoresis (PFGE), spa typing, and multilocus sequence typing. Furthermore, toxin genes detection was also performed. Each pair of isolates has the same PFGE type and spa type. Four Sequence types (STs) were found among all the isolates; they are ST15, ST188, and ST59, respectively. Among the strains, seb, sec, and tst genes were found, and all were negative for pvl gene. The homology of the S. aureus strains isolated from the infants' stool and the mothers' milk was genetically demonstrated, which indicated that breastfeeding may be important in the transmission of S. aureus infection, and the character of S. aureus needed to be further evaluated.

A Bioanalytical Platform for Simultaneous Detection and Quantification of Biological Toxins

PubMed Central

Weingart, Oliver G.; Gao, Hui; Crevoisier, François; Heitger, Friedrich; Avondet, Marc-André; Sigrist, Hans

2012-01-01

Prevalent incidents support the notion that toxins, produced by bacteria, fungi, plants or animals are increasingly responsible for food poisoning or intoxication. Owing to their high toxicity some toxins are also regarded as potential biological warfare agents. Accordingly, control, detection and neutralization of toxic substances are a considerable economic burden to food safety, health care and military biodefense. The present contribution describes a new versatile instrument and related procedures for array-based simultaneous detection of bacterial and plant toxins using a bioanalytical platform which combines the specificity of covalently immobilized capture probes with a dedicated instrumentation and immuno-based microarray analytics. The bioanalytical platform consists of a microstructured polymer slide serving both as support of printed arrays and as incubation chamber. The platform further includes an easy-to-operate instrument for simultaneous slide processing at selectable assay temperature. Cy5 coupled streptavidin is used as unifying fluorescent tracer. Fluorescence image analysis and signal quantitation allow determination of the toxin’s identity and concentration. The system’s performance has been investigated by immunological detection of Botulinum Neurotoxin type A (BoNT/A), Staphylococcal enterotoxin B (SEB), and the plant toxin ricin. Toxins were detectable at levels as low as 0.5–1 ng·mL−1 in buffer or in raw milk. PMID:22438766

Safety Evaluation of the Coagulase-Negative Staphylococci Microbiota of Salami: Superantigenic Toxin Production and Antimicrobial Resistance.

PubMed

Soares Casaes Nunes, Raquel; Mere Del Aguila, Eduardo; Paschoalin, Vânia Margaret Flosi

2015-01-01

The risks of contracting staphylococci food poisoning by the consumption of improperly manufactured salami and the possibility of this food being reservoirs for antibiotic resistance were evaluated. Nineteen coagulase-negative staphylococci (CNS) strains were found in commercial and artisanal salami. The species in commercial salami were S. saprophyticus, S. sciuri, S. xylosus, and S. carnosus. Artisanal salami showed S. succinus, S. epidermidis, and S. hominis but no S. carnosus. Phylogenetic analyses grouped the strains into three major staphylococcal species groups, comprised of 4 refined clusters with similarities superior to 90%. Fifteen strains harbored multiple enterotoxin genes, with high incidence of seb/sec and sea, 57% and 50%, respectively, intermediate incidence of sed/seh/selm and sei/seln/tst-H, 33% and 27%, correspondingly, and low incidence of see/selj/selo and seg, of respectively 13% and 1%. Real time RT-PCR and enzyme-linked-immunosorbent assays confirmed the enterotoxigenicity of the strains, which expressed and produced enterotoxins in vitro. The CNS strains showed multiresistance to several antimicrobials of therapeutic importance in both human and veterinarian medicine, such as β-lactams, vancomycin, and linezolid. The effective control of undue staphylococci in fermented meat products should be adopted to prevent or limit the risk of food poisoning and the spread of antimicrobial-resistant strains.

Role of IL-1 Beta in the Development of Human TH17 Cells: Lesson from NLPR3 Mutated Patients

PubMed Central

Lasigliè, Denise; Traggiai, Elisabetta; Federici, Silvia; Alessio, Maria; Buoncompagni, Antonella; Accogli, Andrea; Chiesa, Sabrina; Penco, Federica; Martini, Alberto; Gattorno, Marco

2011-01-01

Background T helper 17 cells (TH-17) represent a lineage of effector T cells critical in host defence and autoimmunity. In both mouse and human IL-1β has been indicated as a key cytokine for the commitment to TH-17 cells. Cryopyrin-associated periodic syndromes (CAPS) are a group of inflammatory diseases associated with mutations of the NLRP3 gene encoding the inflammasome component cryopyrin. In this work we asked whether the deregulated secretion of IL-1β secondary to mutations characterizing these patients could affect the IL-23/IL-17 axis. Methodology/Principal Findings A total of 11 CAPS, 26 systemic onset juvenile idiopathic arthritis (SoJIA) patients and 20 healthy controls were analyzed. Serum levels of IL-17 and IL-6 serum were assessed by ELISA assay. Frequency of TH17 cells was quantified upon staphylococcus enterotoxin B (SEB) stimulation. Secretion of IL-1β, IL-23 and IL-6 by monocyte derived dendritic cells (MoDCs), were quantified by ELISA assay. A total of 8 CAPS and 11 SoJIA patients were also analysed before and after treatment with IL-1β blockade. Untreated CAPS patients showed significantly increased IL-17 serum levels as well as a higher frequency of TH17 compared to control subjects. On the contrary, SoJIA patients displayed a frequency of TH17 similar to normal donors, but were found to have significantly increased serum level of IL-6 when compared to CAPS patients or healthy donors. Remarkably, decreased IL-17 serum levels and TH17 frequency were observed in CAPS patients following in vivo IL-1β blockade. On the same line, MoDCs from CAPS patients exhibited enhanced secretion of IL-1β and IL-23 upon TLRs stimulation, with a reduction after anti-IL-1 treatment. Conclusion/Significance These findings further support the central role of IL-1β in the differentiation of TH17 in human inflammatory conditions. PMID:21637346

Continuous monitoring bed-level dynamics on an intertidal flat: introducing novel stand-alone high-resolution SED-sensors

NASA Astrophysics Data System (ADS)

Hu, Zhan; Lenting, Walther; van der Wal, Daphne; Bouma, Tjeerd

2015-04-01

Tidal flat morphology is continuously shaped by hydrodynamic force, resulting in highly dynamic bed elevations. The knowledge of short-term bed-level changes is important both for understanding sediment transport processes as well as for assessing critical ecological processes such as e.g. vegetation recruitment chances on tidal flats. Due to the labour involved, manual discontinuous measurements lack the ability to continuously monitor bed-elevation changes. Existing methods for automated continuous monitoring of bed-level changes lack vertical accuracy (e.g., Photo-Electronic Erosion Pin sensor and resistive rod) or limited in spatial application by using expensive technology (e.g., acoustic bed level sensors). A method provides sufficient accuracy with a reasonable cost is needed. In light of this, a high-accuracy sensor (2 mm) for continuously measuring short-term Surface-Elevation Dynamics (SED-sensor) was developed. This SED-sensor makes use of photovoltaic cells and operates stand-alone using internal power supply and data logging system. The unit cost and the labour in deployments is therefore reduced, which facilitates monitoring with a number of units. In this study, the performance of a group of SED-sensors is tested against data obtained with precise manual measurements using traditional Sediment Erosion Bars (SEB). An excellent agreement between the two methods was obtained, indicating the accuracy and precision of the SED-sensors. Furthermore, to demonstrate how the SED-sensors can be used for measuring short-term bed-level dynamics, two SED-sensors were deployed for 1 month at two sites with contrasting wave exposure conditions. Daily bed-level changes were obtained including a severe storm erosion event. The difference in observed bed-level dynamics at both sites was statistically explained by their different hydrodynamic conditions. Thus, the stand-alone SED-sensor can be applied to monitor sediment surface dynamics with high vertical and temporal resolutions, which provides opportunities to pinpoint morphological responses to various forces in a number of environments (e.g. tidal flats, beaches, rivers and dunes).

Variability of Jupiter's Five-Micron Hot Spot Inventory

NASA Technical Reports Server (NTRS)

Yanamandra-Fisher, Padma A.; Orton, G. S.; Wakefield, L.; Rogers, J. H.; Simon-Miller, A. A.; Boydstun, K.

2012-01-01

Global upheavals on Jupiter involve changes in the albedo of entire axisymmetric regions, lasting several years, with the last two occurring in 1989 and 2006. Against this backdrop of planetary-scale changes, discrete features such as the Great Red Spot (GRS), and other vortices exhibit changes on shorter spatial- and time-scales. We track the variability of the discrete equatorial 5-micron hot spots, semi-evenly spaced in longitude and confined to a narrow latitude band centered at 6.5degN (southern edge of the North Equatorial Belt, NEB), abundant in Voyager images. Tantalizingly similar patterns were observed in the visible (bright plumes and blue-gray regions), where reflectivity in the red is anti-correlated with 5-microns thermal radiance. Ortiz et al. (1998, GRL, 103) characterized the latitude and drift rates of the hot spots, including the descent of the Galileo probe at the southern edge of a 5-micron hot spot, as the superposition of equatorial Rossby waves, with phase speeds between 99 - 103m/s, relative to System III. We note that the high 5-micron radiances correlate well but not perfectly with high 8.57-micron radiances. Because the latter are modulated primarily by changes in the upper ammonia (NH3) ice cloud opacity, this correlation implies that changes in the ammonia ice cloud field may be responsible for the variability seen in the 5-m maps. During the NEB fade (2011 - early 2012), however, these otherwise ubiquitous features were absent, an atmospheric state not seen in decades. The ongoing NEB revival indicates nascent 5-m hot spots as early as April 2012, with corresponding visible dark spots. Their continuing growth through July 2012 indicates the possit.le re-establishment of Rossby waves. The South Equatorial Belt (SEB) and NEB revivals began similarly with an instability that developed into a major outbreak, and many similarities in the observed propagation of clear regions.

Isolation of anti-toxin single domain antibodies from a semi-synthetic spiny dogfish shark display library.

PubMed

Liu, Jinny L; Anderson, George P; Goldman, Ellen R

2007-11-19

Shark heavy chain antibody, also called new antigen receptor (NAR), consists of one single Variable domain (VH), containing only two complementarity-determining regions (CDRs). The antigen binding affinity and specificity are mainly determined by these two CDRs. The good solubility, excellent thermal stability and complex sequence variation of small single domain antibodies (sdAbs) make them attractive alternatives to conventional antibodies. In this report, we construct and characterize a diversity enhanced semi-synthetic NAR V display library based on naturally occurring NAR V sequences. A semi-synthetic shark sdAb display library with a complexity close to 1e9 was constructed. This was achieved by introducing size and sequence variations in CDR3 using randomized CDR3 primers of three different lengths. Binders against three toxins, staphylococcal enterotoxin B (SEB), ricin, and botulinum toxin A (BoNT/A) complex toxoid, were isolated from panning the display library. Soluble sdAbs from selected binders were purified and evaluated using direct binding and thermal stability assays on the Luminex 100. In addition, sandwich assays using sdAb as the reporter element were developed to demonstrate their utility for future sensor applications. We demonstrated the utility of a newly created hyper diversified shark NAR displayed library to serve as a source of thermal stable sdAbs against a variety of toxins.

Fracture Mechanics Testing of Titanium 6AL-4V in AF-M315E

NASA Technical Reports Server (NTRS)

Sampson, J. W.; Martinez, J.; McLean, C.

2016-01-01

The Green Propellant Infusion Mission (GPIM) will demonstrate the performance of AF-M315E monopropellant on orbit. Flight certification requires a safe-life analysis of the titanium alloy fuel tank to ensure inherent processing flaws will not cause failure during the design life of the tank. Material property inputs for this analysis require testing to determine the stress intensity factor for environment-assisted cracking (KEAC) of Ti 6Al-4V in combination with the AF-M315E monopropellant. Testing of single-edge notched, or SE(B), specimens representing the bulk tank membrane and weld material were performed in accordance with ASTM E1681. Specimens with fatigue pre-cracks were loaded into test fixtures so that the crack tips were exposed to AF-M315E at 50 C for a duration of 1,000 hours. Specimens that did not fail during exposure were opened to inspect the crack surfaces for evidence of crack growth. The threshold stress intensity value, KEAC, is the highest applied stress intensity that produced neither a failure of the specimen during the exposure nor showed evidence of crack growth. The threshold stress intensity factor for environment-assisted cracking of the Ti 6Al-4V forged tank material was found to be at least 22 ksivin and at least 31 ksivin for the weld material when exposed to AF-M315E monopropellant.

Frequency of enterotoxins, toxic shock syndrome toxin-1, and biofilm formation genes in Staphylococcus aureus isolates from cows with mastitis in the Northeast of Brazil.

PubMed

Costa, F N; Belo, N O; Costa, E A; Andrade, G I; Pereira, L S; Carvalho, I A; Santos, R L

2018-06-01

Staphylococcus aureus is among the microorganisms more frequently associated with subclinical bovine mastitis. S. aureus may produce several virulence factors. This study aimed at determining the frequency of virulence factors such as enterotoxins, toxic shock syndrome toxin 1, and ica adhesion genes. In addition, we assessed antimicrobial drug resistance in S. aureus isolated from clinical and subclinical cases of mastitis. A total of 88 cows with clinical or subclinical mastitis were sampled, resulting in 38 S. aureus isolates, from which 25 (65.78%) carried toxin genes, including seb, sec, sed, tst, and icaD adhesion gene. These S. aureus isolates belong to 21 ribotypes and three S. aureus strains belonged to the same ribotype producing ica adhesion gene. Approximately 90% of S. aureus strains obtained in our study demonstrated multiple resistance to different antimicrobial agents. The most efficacious antimicrobial agents against the isolates were gentamicin, amoxicillin, and norfloxacin. Gentamicin was the most efficacious agent inhibiting 78.95% of the S. aureus isolates. The least efficacious were penicillin, streptomycin, and ampicillin. Our results can help in understanding the relationship between virulence factors and subclinical mastitis caused by S. aureus. Further research about diversity of S. aureus isolates and genes responsible for the pathogenicity of subclinical mastitis is essential.

Binary release of ascorbic acid and lecithin from core-shell nanofibers on blood-contacting surface for reducing long-term hemolysis of erythrocyte.

PubMed

Shi, Qiang; Fan, Qunfu; Ye, Wei; Hou, Jianwen; Wong, Shing-Chung; Xu, Xiaodong; Yin, Jinghua

2015-01-01

There is an urgent need to develop blood-contacting biomaterials with long-term anti-hemolytic capability. To obtain such biomaterials, we coaxially electrospin [ascorbic acid (AA) and lecithin]/poly (ethylene oxide) (PEO) core-shell nanofibers onto the surface of styrene-b-(ethylene-co-butylene)-b-styrene elastomer (SEBS) that has been grafted with poly (ethylene glycol) (PEG) chains. Our strategy is based on that the grafted layers of PEG render the surface hydrophilic to reduce the mechanical injure to red blood cells (RBCs) while the AA and lecithin released from nanofibers on blood-contacting surface can actively interact with RBCs to decrease the oxidative damage to RBCs. We demonstrate that (AA and lecithin)/PEO core-shell structured nanofibers have been fabricated on the PEG grafted surface. The binary release of AA and lecithin in the distilled water is in a controlled manner and lasts for almost 5 days; during RBCs preservation, AA acts as an antioxidant and lecithin as a lipid supplier to the membrane of erythrocytes, resulting in low mechanical fragility and hemolysis of RBCs, as well as high deformability of stored RBCs. Our work thus makes a new approach to fabricate blood-contacting biomaterials with the capability of long-term anti-hemolysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Food poisoning outbreak in Tokyo, Japan caused by Staphylococcus argenteus.

PubMed

Suzuki, Yasunori; Kubota, Hiroaki; Ono, Hisaya K; Kobayashi, Makiko; Murauchi, Konomi; Kato, Rei; Hirai, Akihiko; Sadamasu, Kenji

2017-12-04

Staphylococcus argenteus is a novel species subdivided from Staphylococcus aureus. Whether this species can cause food poisoning outbreaks is unknown. This study aimed to investigate the enterotoxigenic activities of two food poisoning isolates suspected to be S. argenteus (Tokyo13064 and Tokyo13069). The results for phylogenic trees, constructed via whole genome sequencing, demonstrated that both isolates were more similar to a type strain of S. argenteus (MSHR1132) than any S. aureus strain. Moreover, the representative characteristics of S. argenteus were present in both strains, namely both isolates belong to the CC75 lineage and both lack a crtOPQMN operon. Thus, both were determined to be "S. argenteus." The compositions of the two isolates' accessory elements differed from those of MSHR1132. For example, the seb-related Staphylococcus aureus pathogenicity island, SaPIishikawa11, was detected in Tokyo13064 and Tokyo13069 but not in MSHR1132. Both isolates were suggested to belong to distinct lineages that branched off from MSHR1132 lineages in terms of accessory elements. Tokyo13064 and Tokyo13069 expressed high levels of s(arg)eb and produced S(arg)EB protein, indicating that both have the ability to cause food poisoning. Our findings suggest that S. argenteus harboring particular accessory elements can cause staphylococcal diseases such as food poisoning, similarly to S. aureus. Copyright © 2017 Elsevier B.V. All rights reserved.

Sanitary quality, occurrence and identification of Staphylococcus sp. in food services.

PubMed

de Mello, Jozi Fagundes; da Rocha, Laura Braga; Lopes, Ester Souza; Frazzon, Jeverson; da Costa, Marisa

2014-01-01

Sanitary conditions are essential for the production of meals and control of the presence of pathogensis important to guarantee the health of customers. The aim of this study was to evaluate the sanitary quality of food services by checking the presence of thermotolerant coliforms, Staphylococcus sp. and evaluate the toxigenic potential from the latter. The analysis was performed on water, surfaces, equipment, ready-to-eat foods, hands and nasal cavity of handlers in seven food services. The water used in food services proved to be suitable for the production of meals. Most food, equipment and surfaces showed poor sanitary conditions due to the presence of thermotolerant coliforms (60.6%). Twenty-six Staphylococcus species were identified from the 121 Staphylococcus isolates tested. Staphylococci coagulase-negative species were predominant in the foods, equipment and surfaces. In food handlers and foods, the predominant species was Staphylococcus epidermidis. Twelve different genotypes were found after PCR for the classical enterotoxin genes. The seb gene (19.8%) was the most prevalent among all Staphylococcus sp. Both coagulase-positive and coagulase-negative Staphylococci showed some of the genes of the enterotoxins tested. We conclude that there are hygienic and sanitary deficiencies in the food services analyzed. Although coagulase-positive Staphylococci have not been present in foods there is a wide dispersion of enterotoxigenic coagulase-negative Staphylococci in the environment and in the foods analyzed, indicating a risk to consumer health.

High proportions of Staphylococcus epidermidis in dental caries harbor multiple classes of antibiotics resistance, significantly increase inflammatory interleukins in dental pulps.

PubMed

Devang Divakar, Darshan; Muzaheed; Aldeyab, Sultan Salem; Alfawaz, Sara A; AlKheraif, Abdulaziz Abdullah; Ahmed Khan, Aftab

2017-08-01

Staphylococcus epidermidis is one of most prevalent in dental caries or dental pulp which has the capability of horizontal genetic transfer between different bacterial species in the oropharynx, suggesting that it may evolve with the dissemination of resistant determinants, This study was performed to molecularly characterize and differentiate S. epidermidis isolated from dental caries and healthy individual. Also, two important cytokines in inflammation were assayed caused due to S. epidermidis of health and dental caries sources. Dental caries strains were more resistant with high MIC 50 and MIC 90 value. These isolates also showed the presence of mecA gene and another virulence gene i. e sea and seb comparatively more than healthy individual isolates. SCCmec types, III and IV was more prevalent in dental caries isolates where an as healthy individual was more non-typable. Additionally, the quantity of IL-1β and IL-8 caused due to dental caries isolates was seen more which indicate dental caries isolates are able to induce. This study showed that S. epidermidis a normal flora of oropharyngeal are more diverse to those strains which cause dental caries. S. epidermidis owns a prodigious genetic plasticity that permits to obtain, lose or regulate genetic elements that provide compensations to improve its colonization in the host. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sanitary quality, occurrence and identification of Staphylococcus sp. in food services

PubMed Central

de Mello, Jozi Fagundes; da Rocha, Laura Braga; Lopes, Ester Souza; Frazzon, Jeverson; da Costa, Marisa

2014-01-01

Sanitary conditions are essential for the production of meals and control of the presence of pathogensis important to guarantee the health of customers. The aim of this study was to evaluate the sanitary quality of food services by checking the presence of thermotolerant coliforms, Staphylococcus sp. and evaluate the toxigenic potential from the latter. The analysis was performed on water, surfaces, equipment, ready-to-eat foods, hands and nasal cavity of handlers in seven food services. The water used in food services proved to be suitable for the production of meals. Most food, equipment and surfaces showed poor sanitary conditions due to the presence of thermotolerant coliforms (60.6%). Twenty-six Staphylococcus species were identified from the 121 Staphylococcus isolates tested. Staphylococci coagulase-negative species were predominant in the foods, equipment and surfaces. In food handlers and foods, the predominant species was Staphylococcus epidermidis. Twelve different genotypes were found after PCR for the classical enterotoxin genes. The seb gene (19.8%) was the most prevalent among all Staphylococcus sp. Both coagulase-positive and coagulase-negative Staphylococci showed some of the genes of the enterotoxins tested. We conclude that there are hygienic and sanitary deficiencies in the food services analyzed. Although coagulase-positive Staphylococci have not been present in foods there is a wide dispersion of enterotoxigenic coagulase-negative Staphylococci in the environment and in the foods analyzed, indicating a risk to consumer health. PMID:25477940

Isolation of anti-toxin single domain antibodies from a semi-synthetic spiny dogfish shark display library

PubMed Central

Liu, Jinny L; Anderson, George P; Goldman, Ellen R

2007-01-01

Background Shark heavy chain antibody, also called new antigen receptor (NAR), consists of one single Variable domain (VH), containing only two complementarity-determining regions (CDRs). The antigen binding affinity and specificity are mainly determined by these two CDRs. The good solubility, excellent thermal stability and complex sequence variation of small single domain antibodies (sdAbs) make them attractive alternatives to conventional antibodies. In this report, we construct and characterize a diversity enhanced semi-synthetic NAR V display library based on naturally occurring NAR V sequences. Results A semi-synthetic shark sdAb display library with a complexity close to 1e9 was constructed. This was achieved by introducing size and sequence variations in CDR3 using randomized CDR3 primers of three different lengths. Binders against three toxins, staphylococcal enterotoxin B (SEB), ricin, and botulinum toxin A (BoNT/A) complex toxoid, were isolated from panning the display library. Soluble sdAbs from selected binders were purified and evaluated using direct binding and thermal stability assays on the Luminex 100. In addition, sandwich assays using sdAb as the reporter element were developed to demonstrate their utility for future sensor applications. Conclusion We demonstrated the utility of a newly created hyper diversified shark NAR displayed library to serve as a source of thermal stable sdAbs against a variety of toxins. PMID:18021450

Virulence properties of methicillin-susceptible Staphylococcus aureus food isolates encoding Panton-Valentine Leukocidin gene.

PubMed

Sudagidan, Mert; Aydin, Ali

2010-04-15

In this study, three Panton-Valentine Leukocidin gene carrying methicillin-susceptible Staphylococcus aureus (MSSA) strains (M1-AAG42B, PY30C-b and YF1B-b) were isolated from different food samples in Kesan-Edirne, Turkey. These strains were characterized on the basis of MLST type, spa type, virulence factor gene contents, antibiotic susceptibilities against 21 antibiotics and biofilm formation. The genetic relatedness of the strains was determined by PFGE. In addition, the complete gene sequences of lukS-PV and lukF-PV were also investigated. All strains were found to be susceptible to tested antibiotics and they were mecA negative. Three strains showed the same PFGE band pattern, ST152 clonal type and t355 spa type. In the detection of virulence factor genes, sea, seb, sec, sed, see, seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq, seu, eta, etb, set1, geh and tst genes were not detected. All strains showed the positive results for alpha- and beta-haemolysin genes (hla and hlb), protease encoding genes (sspA, sspB and aur), lukE and lukD leukocidin genes (lukED). The strains were found to be non-biofilm formers. By this study, the virulence properties of the strains were described and this is one of the first reports regarding PVL-positive MSSA strains from food. (c) 2010 Elsevier B.V. All rights reserved.

Fracture Growth Testing of Titanium 6AL-4V in AF-M315E

NASA Technical Reports Server (NTRS)

Sampson, Jeffrey W.; Martinez, Jonathan; McLean, Christopher

2015-01-01

The Green Propellant Infusion Mission (GPIM) will demonstrate the performance of AF-M315E monopropellant in orbit. Flight certification requires a safe-life analysis of the titanium alloy fuel tank to ensure inherent flaws will not cause failure during the design life. Material property inputs for this analysis require testing to determine the stress intensity factor for environmentally-assisted cracking (K (sub EAC)) of Ti 6Al-4V in combination with the AF-M315E monopropellant. Testing of single-edge notched specimens SE(B) representing the bulk tank membrane and weld material were performed in accordance with ASTM E1681. Specimens with fatigue pre-cracks were loaded into test fixtures so that the crack tips were exposed to the monopropellant at 50 degrees Centigrade for a duration of 1,000 hours. Specimens that did not fail during exposure were opened to inspect the crack surfaces for evidence of crack growth. The threshold stress intensity value, KEAC, is the highest applied stress intensity that produced neither a failure of the specimen during the exposure nor showed evidence of crack growth. The threshold stress intensity factor of the Ti 6Al-4V forged tank material when exposed to AF-M315E monopropellant was found to be at least 22.0 kilopounds per square inch. The stress intensity factor of the weld material was at least 31.3 kilopounds per square inch.

EBF proteins participate in transcriptional regulation of Xenopus muscle development.

PubMed

Green, Yangsook Song; Vetter, Monica L

2011-10-01

EBF proteins have diverse functions in the development of multiple lineages, including neurons, B cells and adipocytes. During Drosophila muscle development EBF proteins are expressed in muscle progenitors and are required for muscle cell differentiation, but there is no known function of EBF proteins in vertebrate muscle development. In this study, we examine the expression of ebf genes in Xenopus muscle tissue and show that EBF activity is necessary for aspects of Xenopus skeletal muscle development, including somite organization, migration of hypaxial muscle anlagen toward the ventral abdomen, and development of jaw muscle. From a microarray screen, we have identified multiple candidate targets of EBF activity with known roles in muscle development. The candidate targets we have verified are MYOD, MYF5, M-Cadherin and SEB-4. In vivo overexpression of the ebf2 and ebf3 genes leads to ectopic expression of these candidate targets, and knockdown of EBF activity causes downregulation of the endogenous expression of the candidate targets. Furthermore, we found that MYOD and MYF5 are likely to be direct targets. Finally we show that MYOD can upregulate the expression of ebf genes, indicating the presence of a positive feedback loop between EBF and MYOD that we find to be important for maintenance of MYOD expression in Xenopus. These results suggest that EBF activity is important for both stabilizing commitment and driving aspects of differentiation in Xenopus muscle cells. Copyright © 2010 Elsevier Inc. All rights reserved.

Effect of in vitro chewing and bruxism events on remineralization, at the resin-dentin interface.

PubMed

Toledano, Manuel; Cabello, Inmaculada; Aguilera, Fátima S; Osorio, Estrella; Osorio, Raquel

2015-01-02

The purpose of this study was to evaluate if different in vitro functional and parafunctional habits promote mineralization at the resin-dentin interface after bonding with three different adhesive approaches. Dentin surfaces were subjected to distinct treatments: demineralization by (1) 37% phosphoric acid (PA) followed by application of an etch-and-rinse dentin adhesive, Single Bond (SB) (PA+SB); (2) 0.5 M ethylenediaminetetraacetic acid (EDTA) followed by SB (EDTA+SB); (3) application of a self-etch dentin adhesive, Clearfil SE Bond (SEB). Different loading waveforms were applied: No cycling (I), cycled in sine (II) or square (III) waves, sustained loading hold for 24 h (IV) or sustained loading hold for 72 h (V). Remineralization at the bonded interfaces was assessed by AFM imaging/nano-indentation, Raman spectroscopy and Masson's trichrome staining. In general, in vitro chewing and parafunctional habits, promoted an increase of nano-mechanical properties at the resin-dentin interface. Raman spectroscopy through cluster analysis demonstrated an augmentation of the mineral-matrix ratio in loaded specimens. Trichrome staining reflected a narrow demineralized dentin matrix after loading in all groups except in PA+SB and EDTA+SB samples after sustained loading hold for 72 h, which exhibited a strong degree of mineralization. In vitro mechanical loading, produced during chewing and bruxism (square or hold 24 and 72 h waveforms), induced remineralization at the resin-dentin bonded interface. Copyright © 2014 Elsevier Ltd. All rights reserved.

SUNrises on the International Plant Nucleus Consortium: SEB Salzburg 2012.

PubMed

Graumann, Katja; Bass, Hank W; Parry, Geraint

2013-01-01

The nuclear periphery is a dynamic, structured environment, whose precise functions are essential for global processes-from nuclear, to cellular, to organismal. Its main components-the nuclear envelope (NE) with inner and outer nuclear membranes (INM and ONM), nuclear pore complexes (NPC), associated cytoskeletal and nucleoskeletal components as well as chromatin are conserved across eukaryotes (Fig. 1). In metazoans in particular, the structure and functions of nuclear periphery components are intensely researched partly because of their involvement in various human diseases. While far less is known about these in plants, the last few years have seen a significant increase in research activity in this area. Plant biologists are not only catching up with the animal field, but recent findings are pushing our advances in this field globally. In recognition of this developing field, the Annual Society of Experimental Biology Meeting in Salzburg kindly hosted a session co-organized by Katja Graumann and David E. Evans (Oxford Brookes University) highlighting new insights into plant nuclear envelope proteins and their interactions. This session brought together leading researchers with expertise in topics such as epigenetics, meiosis, nuclear pore structure and functions, nucleoskeleton and nuclear envelope composition. An open and friendly exchange of ideas was fundamental to the success of the meeting, which resulted in founding the International Plant Nucleus Consortium. This review highlights new developments in plant nuclear envelope research presented at the conference and their importance for the wider understanding of metazoan, yeast and plant nuclear envelope functions and properties.

Virulence factors genes of Staphylococcus spp. isolated from caprine subclinical mastitis.

PubMed

Salaberry, Sandra Renata Sampaio; Saidenberg, André Becker Simões; Zuniga, Eveline; Melville, Priscilla Anne; Santos, Franklin Gerônimo Bispo; Guimarães, Ednaldo Carvalho; Gregori, Fábio; Benites, Nilson Roberti

2015-08-01

The aim of this study was to investigate genes involved in adhesion expression, biofilm formation, and enterotoxin production in isolates of Staphylococcus spp. from goats with subclinical mastitis and associate these results with the staphylococcal species. One hundred and twenty-four isolates were identified and polymerase chain reaction (PCR) was performed to detect the following genes: cna, ebpS, eno, fib, fnbA, fnbB, bap, sea, seb, sec, sed and see. The most commonly Staphylococcus species included S. epidermidis, S. lugdunensis, S. chromogenes, S. capitis ss capitis and S. intermedius. With the exception of fnbB, the genes were detected in different frequencies of occurrence in 86.3% of the Staphylococcus spp. isolates. Eno (73.2%) and bap (94.8%) were more frequently detected in coagulase-negative staphylococci (CNS); ebpS (76%), fib (90.9%) and fnbA (87%) were the most frequent genes in coagulase-positive staphylococci (CPS). Regarding enterotoxins, genes sed (28.2%) and see (24.2%) had a higher frequency of occurrence; sec gene was more frequently detected in CPS (58.8%). There was no association between the presence of the genes and the Staphylococcus species. Different virulence factors genes can be detected in caprine subclinical mastitis caused by CNS and CPS. The knowledge of the occurrence of these virulence factors is important for the development of effective control and prevention measures of subclinical mastitis caused by CNS and CPS in goats. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification and prevalence of coral diseases on three Western Indian Ocean coral reefs.

PubMed

Séré, Mathieu G; Chabanet, Pascale; Turquet, Jean; Quod, Jean-Pascal; Schleyer, Michael H

2015-06-03

Coral diseases have caused a substantial decline in the biodiversity and abundance of reef-building corals. To date, more than 30 distinct diseases of scleractinian corals have been reported, which cause progressive tissue loss and/or affect coral growth, reproductive capacity, recruitment, species diversity and the abundance of reef-associated organisms. While coral disease research has increased over the last 4 decades, very little is known about coral diseases in the Western Indian Ocean. Surveys conducted at multiple sites in Reunion, South Africa and Mayotte between August 2010 and June 2012 revealed the presence of 6 main coral diseases: black band disease (BBD), white syndrome (WS), pink line syndrome (PLS), growth anomalies (GA), skeleton eroding band (SEB) and Porites white patch syndrome (PWPS). Overall, disease prevalence was higher in Reunion (7.5 ± 2.2%; mean ± SE) compared to South Africa (3.9 ± 0.8%) and Mayotte (2.7 ± 0.3%). Across locations, Acropora and Porites were the genera most susceptible to disease. Spatial variability was detected in both Reunion and South Africa, with BBD and WS more prevalent on shallow than deep reefs. There was also evidence of seasonality in 2 diseases: the prevalence of BBD and WS was higher in summer than winter. This was the first study to investigate the ecology of coral diseases, providing both qualitative and quantitative data, on Western Indian Ocean reefs, and surveys should be expanded to confirm these patterns.

Durability assessment of soft elastomeric capacitor skin for SHM of wind turbine blades

NASA Astrophysics Data System (ADS)

Downey, Austin; Pisello, Anna Laura; Fortunati, Elena; Fabiani, Claudia; Luzi, Francesca; Torre, Luigi; Ubertini, Filippo; Laflamme, Simon

2018-03-01

Renewable energy production has become a key research driver during the last decade. Wind energy represents a ready technology for large-scale implementation in locations all around the world. While important research is conducted to optimize wind energy production efficiency, a critical issue consists of monitoring the structural integrity and functionality of these large structures during their operational life cycle. This paper investigates the durability of a soft elastomeric capacitor strain sensing membrane, designed for structural health monitoring of wind turbines, when exposed to aggressive environmental conditions. The sensor is a capacitor made of three thin layers of an SEBS polymer in a sandwich configuration. The inner layer is doped with titania and acts as the dielectric, while the external layers are filled with carbon black and work as the conductive plates. Here, a variety of samples, not limited to the sensor configuration but also including its dielectric layer, were fabricated and tested within an accelerated weathering chamber (QUV) by simulating thermal, humidity, and UV radiation cycles. A variety of other tests were performed in order to characterize their mechanical, thermal, and electrical performance in addition to their solar reflectance. These tests were carried out before and after the QUV exposures of 1, 7, 15, and 30 days. The tests showed that titania inclusions improved the sensor durability against weathering. These findings contribute to better understanding the field behavior of these skin sensors, while future developments will concern the analysis of the sensing properties of the skin after aging.

Principles for new optical techniques in medical diagnostics for mHealth applications

NASA Astrophysics Data System (ADS)

Balsam, Joshua Michael

Medical diagnostics is a critical element of effective medical treatment. However, many modern and emerging diagnostic technologies are not affordable or compatible with the needs and conditions found in low-income and middle-income countries and regions. Resource-poor areas require low-cost, robust, easy-to-use, and portable diagnostics devices compatible with telemedicine (i.e. mHealth) that can be adapted to meet diverse medical needs. Many suitable devices will need to be based on optical technologies, which are used for many types of biological analyses. This dissertation describes the fabrication and detection principles for several low-cost optical technologies for mHealth applications including: (1) a webcam based multi-wavelength fluorescence plate reader, (2) a lens-free optical detector used for the detection of Botulinum A neurotoxin activity, (3) a low cost micro-array reader that allows the performance of typical fluorescence based assays demonstrated for the detection of the toxin staphylococcal enterotoxin (SEB), and (4) a wide-field flow cytometer for high throughput detection of fluorescently labeled rare cells. This dissertation discusses how these technologies can be harnessed using readily available consumer electronics components such as webcams, cell phones, CCD cameras, LEDs, and laser diodes. There are challenges in developing devices with sufficient sensitivity and specificity, and approaches are presented to overcoming these challenges to create optical detectors that can serve as low cost medical diagnostics in resource-poor settings for mHealth.

Giove 2003-2004: rapporto osservativo

NASA Astrophysics Data System (ADS)

Adamoli, Gianluigi

2005-08-01

The planet was monitored from 2003 September 19 to 2004 August 7, with plenty of digital images and a few visual observations. Undulations in latitude were shown by many belts, with SSTB, STB and NNTB spiralling so as to overpose parallel to themselves after a turn. Bright SPH and an SPB were recorded in the SPR, with spots discernible to about 60°S. The SSTZ anti-cyclonic white ovals were prominent, so as oval BA, well visible amidst dark SSTB/STB features; it was reached by a prograding STB dark sector. A dark STZ spot surpassed the GRS and then became a diagonal streak. The GRS was pale red, with a darker S. edge and a central condensation, followed by the usual train of white spots in SEB. This belt had much structure, with white SEBZ, a central dark component and projections on both edges. EZ was 3/4 veiled and EB was systematically S. of the equator; NEBs activity consisted of the usual festoons, often distorted through the Zone by the wind speed shear, and prominent blue bars on the edge of the belt. The NEB N. edge underwent a new Northern expansion in April; its barges were few and faint, while Roger's Z bay decelerated. A continuous NTrB was present, with NTB very faint; they were blue, while NNTB had a warm hue and the NNTBs jetstream was very active. Many faint belt sectors were recorded N. of it, with spots to about 60°N.

Analysis of the VIDAS® Staph Enterotoxin III (SET3) for Detection of Staphylococcal Enterotoxins G, H, and I in Foods.

PubMed

Hait, Jennifer M; Nguyen, Angela T; Tallent, Sandra M

2018-04-20

Background : Staphylococcal food poisoning (SFP) frequently causes illnesses worldwide. SFP occurs from the ingestion of staphylococcal enterotoxins (SEs) preformed in foods by enterotoxigenic strains of Staphylococcus species, primarily S. aureus . SEG, SEH, and SEI induce emesis and have been implicated in outbreaks. Immunological-based methods are deemed the most practical methods for the routine analysis of SEs in foods given their ease of use, sensitivity, specificity, and commercial availability. These kits are routinely used to test for SEA-SEE. However, only recently has a kit been developed to detect SEG, SEH, and SEI. Objective: Our research examined the performance of the novel VIDAS ® Staph Enterotoxin III (SET3) for the detection of staphylococcal enterotoxins SEG, SEH, and SEI in foods. Methods : Here we assess the sensitivity and specificity of SET3 using duplicate test portions of six foods at varying concentrations of inclusivity and exclusivity inocula: pure SEG, SEH, SEI, S. aureus strain extracts positive for seg, seh , and sei , as well as SEA, SEB, SEC, SED, and SEE. Results : The overall detection limit was less than 2.09 ng/mL for foods inoculated with SEG, SEH, and SEI, with no cross reactivity observed. Highlights : Integrating concurrent testing to detect the presence of SEA-SEE and SEG-SEI utilizing the SET3 along with the VIDAS SET2, Ridascreen ® SET total, or other comparable kits will be instrumental for the future food assessments in our laboratory and may become the new standard for SE analysis of foods.

The tonotopic map in the embryonic chicken cochlea.

PubMed

Jones, S M; Jones, T A

1995-02-01

The purpose of the present study was to determine the tonotopic map in the chicken cochlea at 19 days of incubation (E19) by obtaining characteristic frequencies (CFs) for primary afferents, labeling the characterized neurons, and documenting their projections to the papilla. The lowest and highest CFs recorded were 188 and 1623 Hz respectively. The embryonic tonotopic map coincided with maps reported for post-hatch chicks. There were no evidence that neurons selective to low frequencies project inappropriately to more basal locations of the embryonic papilla. Linear regression was used to estimate the frequency gradient (b = 0.037 +/- 0.012 In Hz/% [b +/- SEb]) and intercept (In C, where C = 111 Hz) of the semilog plot of frequency versus cochlear position (in % distance from apex). From these estimates the octave distribution was calculated to be 18.7%/octave or 0.58 mm/octave. These quantities were not significantly different from those found in post hatch chickens. We conclude that the tonotopic map of the avian cochlea for CFs between 100 and 1700 Hz is stable and relatively mature from age E19 to post-hatch day 21 (P21). The most striking sign of immaturity in the E19 embryo is the limited range of high CFs. We offer the hypothesis that, between the ages of E19 and P21, improvements in middle ear admittance alone or in combination with functional maturation of the cochlear base may be the principal factors responsible for the appearance of adult-like high CF limits and not an apically shifting tonotopic map.

Clonal profile, virulence and resistance of Staphylococcus aureus isolated from sheep milk.

PubMed

Martins, Katheryne Benini; Faccioli-Martins, Patricia Yoshida; Riboli, Danilo Flávio Moraes; Pereira, Valéria Cataneli; Fernandes, Simone; Oliveira, Aline A; Dantas, Ariane; Zafalon, Luiz Francisco; da Cunha, Maria de Lourdes Ribeiro de Souza

2015-06-01

The objective of this study was to characterize the clonal profile, virulence factors and antimicrobial resistance, particularly oxacillin resistance, of Staphylococcus aureus isolated from sheep milk. Milk samples were collected from all teats for the California Mastitis Test (CMT), somatic cell count, identification of S. aureus, investigation in these strains of genes encoding toxins (sea, seb, sec, sed, tst), biofilm (icaA, icaC, icaD, bap), leukocidin (luk-PV) oxacillin resistance by mecA gene detection and susceptibility testing (12 antibiotics). Messenger RNA expression was evaluated by RT-PCR in isolates carrying toxin and biofilm genes. Biofilm formation was also evaluated phenotypically by adherence to polystyrene plates. The clonal profile of S. aureus was investigated by pulsed-field gel electrophoresis. A total of 473 milk samples were collected from 242 animals on three farms and 20 S. aureus strains were isolated and none carried the mecA gene. The two sec gene-positive isolates and the isolates carrying the tst and luk-PV genes were positive by RT-PCR. Staphylococcus aureus isolated from the three flocks studied showed high susceptibility to the drugs tested and none was biofilm producer, indicating that biofilm formation was not a virulence factor causing infection by these strains. The typing of 17 S. aureus isolates revealed the presence of a common clone on the three farms studied, and the presence and expression of the sec and tst genes in one strain of this clone suggest the possible acquisition of virulence genes by this clone, a fact that is important for animal health and food hygiene.

Performance of polyethylene based radiation grafted anion exchange membrane with polystyrene-b-poly (ethylene/butylene)-b-polystyrene based ionomer using NiCo2O4 catalyst for water electrolysis

NASA Astrophysics Data System (ADS)

Gupta, Gaurav; Scott, Keith; Mamlouk, Mohamed

2018-01-01

A soluble anion exchange ionomer with high OH- ion conductivity comparable to that of H+ conductivity of Nafion is synthesised by chloromethylation of polystyrene-b-poly (ethylene/butylene)-b-polystyrene (SEBS) and used with NiCo2O4 electro-catalyst for water electrolysis. The ionomer has an ion exchange capacity of 1.9 mmol g-1 and ionic conductivity of 0.14 S cm-2 at 50 °C. The cell voltage at 20 °C at 100 mA cm-2 is 1.77 and 1.72 V in, 0.1 and 1.0 M NaOH, respectively, for an optimum loading of 10 mg cm-2 NiCo2O4. At 10 mg cm-2 NiCo2O4 electrolyser cell performance is at least equal to or superior to that of IrO2 at 2 mg cm-2 with excellent stability over 1 h. When the catalyst is sprayed on the GDL instead of CCM, the performance is further improved to 1.65 V at 100 mA cm-2 at 60 °C & 0.1 M KOH. The limited AEM electrolyser performance when operating with deionised water in comparison to PEM and alkaline electrolyser arises from the sluggish OER in the AEM environment equivalent to pH of 11.5 and the two orders of magnitude lower HER activity with respect to acid medium combined with the high Tafel slope of 120 mV dec-1.

The tonotopic map in the embryonic chicken cochlea

NASA Technical Reports Server (NTRS)

Jones, S. M.; Jones, T. A.

1995-01-01

The purpose of the present study was to determine the tonotopic map in the chicken cochlea at 19 days of incubation (E19) by obtaining characteristic frequencies (CFs) for primary afferents, labeling the characterized neurons, and documenting their projections to the papilla. The lowest and highest CFs recorded were 188 and 1623 Hz respectively. The embryonic tonotopic map coincided with maps reported for post-hatch chicks. There were no evidence that neurons selective to low frequencies project inappropriately to more basal locations of the embryonic papilla. Linear regression was used to estimate the frequency gradient (b = 0.037 +/- 0.012 In Hz/% [b +/- SEb]) and intercept (In C, where C = 111 Hz) of the semilog plot of frequency versus cochlear position (in % distance from apex). From these estimates the octave distribution was calculated to be 18.7%/octave or 0.58 mm/octave. These quantities were not significantly different from those found in post hatch chickens. We conclude that the tonotopic map of the avian cochlea for CFs between 100 and 1700 Hz is stable and relatively mature from age E19 to post-hatch day 21 (P21). The most striking sign of immaturity in the E19 embryo is the limited range of high CFs. We offer the hypothesis that, between the ages of E19 and P21, improvements in middle ear admittance alone or in combination with functional maturation of the cochlear base may be the principal factors responsible for the appearance of adult-like high CF limits and not an apically shifting tonotopic map.

Association between a Brief Alcohol Craving Measure and Drinking in the Following Week

PubMed Central

McHugh, R. Kathryn; Fitzmaurice, Garrett M.; Griffin, Margaret L.; Anton, Raymond F.; Weiss, Roger D.

2016-01-01

Background and aims Craving for alcohol is thought to be a predictor of alcohol use, particularly in the near future. The assessment of craving in clinical practice requires brief, simple measures that can be implemented routinely. This study tested whether greater alcohol craving was associated with a higher likelihood of alcohol use in the subsequent week. Design The COMBINE Study was a large, multi-site clinical trial of treatment for alcohol dependence. Participants were randomized (stratified by site) to 1 of 9 treatment conditions involving combinations of pharmacotherapy and psychotherapy. Craving was assessed every other week throughout the treatment period. Setting Substance use disorder treatment settings at 11 academic sites across the United States. Participants Participants from the COMBINE Study (N=1,370) with available craving data. Measurements Craving was assessed using the 3-item self-report Craving Scale. Drinking was assessed using the Timeline Followback method, and was defined as alcohol use in each study week. Findings There was an average of 5.8 (of a possible 7) observation pairs per participant. Craving was strongly associated with alcohol use in the following week (B=0.27, SEB=.06, Wald Chi-Square=43.34, OR=1.31, 95% CI=1.16, 1.47, p<.001). For each 1-unit increase in the Craving Scale, the likelihood of drinking in the next week was 31% higher. Conclusions Craving for alcohol is strongly associated with alcohol use in the following week. Clinicians can measure alcohol craving effectively using a brief self-report craving scale. PMID:26780476

Effects of a Carob-Pod-Derived Sweetener on Glucose Metabolism

PubMed Central

Lambert, Carmen; Cubedo, Judit; Padró, Teresa; Vilahur, Gemma; López-Bernal, Sergi; Rocha, Milagros

2018-01-01

Background: Patients with type 2 diabetes mellitus (T2DM) have a higher incidence of cardiovascular (CV) events. The ingestion of high-glycemic index (GI) diets, specially sweetened beverage consumption, has been associated with the development of T2DM and CV disease. Objective: We investigated the effects of the intake of a sweetened beverage, obtained from natural carbohydrates containing pinitol (PEB) compared to a sucrose-enriched beverage (SEB) in the context of impaired glucose tolerance (IGT) and diabetes. Methods: The study was divided in three different phases: (1) a discovery phase where the plasma proteomic profile was investigated by 2-DE (two-dimensional electrophoresis) followed by mass spectrometry (matrix-assisted laser desorption/ionization time-of-flight—MALDI-TOF/TOF) in healthy and IGT volunteers; (2) a verification phase where the potential mechanisms behind the observed protein changes were investigated in the discovery cohort and in an additional group of T2DM volunteers; and (3) the results were validated in a proof-of-concept interventional study in an animal model of diabetic rats with complementary methodologies. Results: Six weeks of pinitol-enriched beverage (PEB) intake induced a significant increase in two proteins involved in the insulin secretion pathway, insulin-like growth factor acid labile subunit (IGF1BP-ALS; 1.3-fold increase; P = 0.200) and complement C4A (1.83-fold increase; P = 0.007) in IGT subjects but not in healthy volunteers. Changes in C4A were also found in the serum samples of Zucker diabetic fatty (ZDF) rats after four weeks of PEB intake compared to basal levels (P = 0.042). In addition, an increased expression of the glucose transporter-2 (GLUT2) gene was observed in the jejunum (P = 0.003) of inositol-supplemented rats when compared to sucrose supplementation. This change was correlated with the observed change in C4A (P = 0.002). Conclusions: Our results suggest that the substitution of a common sugar source, such as sucrose, by a naturally-based, pinitol-enriched beverage induces changes in the insulin secretion pathway that could help to reduce blood glucose levels by protecting β-cells and by stimulating the insulin secretion pathway. This mechanism of action could have a relevant role in the prevention of insulin resistance and diabetes progression. PMID:29495516

Turkish Ministry of Health, 2nd Turkish Medical General Assembly Clinical Oncology Study Group Report

PubMed Central

Özmen, Vahit; Dağoğlu, Nergiz; Dede, İsmet; Akçakaya, Adem; Kerem, Mustafa; Göksel, Fatih; Özgür, Enver; Başkan, Emel; Yaylacı, Mustafa; Ceydeli, Adil; Baykara, Meltem; Kızıltan, Huriye Şenay; Kömürcü, Şeref; Gümüş, Mahmut; Türk, H. Mehmet; Demirhan, Recep; Akgün, Ali; Kadoglou, Naim; Yatman, Emre; Elbi, Cem Cüneyt; Güleç, Seza; Soran, Atilla; Özet, Ahmet; Keleştimur, Fahrettin

2016-01-01

Objective There is an increase in the incidence of cancer, and consequently in mortality rates, both in the world and in Turkey. The increase in the incidence and mortality rate of cancer are more prominent in our country as well as in other developing countries. The aim of this workshop was to determine the current status on prevention, screening, early diagnosis and treatment of cancer in our country, to identify related shortcomings, specify solutions and to share these with health system operators, and to aid in implementation of these systems. Developments on palliative care were also evaluated. Materials and Methods The current situation in the practice of clinical oncology, related drawbacks, problems encountered during multidisciplinary approach and their solutions were discussed under several sub-headings during a 3-day meeting organized by the Turkish Ministry of Health (Türkiye Cumhuriyeti Sağlık Bakanlığı-TCSB) with participation of 16 scientists from Turkey and 6 from abroad, and the conclusions were reported. Results It is expected that the newly established Turkish Health Institutes Association (Türkiye Sağlık Enstitüleri Başkanlığı-TÜSEB) and the National Cancer Institute (Ulusal Kanser Enstitüsü) will provide a new framework in the field of oncology. The current positive findings include the increase in the number of scientists who carry out successful trials in oncology both in Turkey and abroad, the implementation of the national cancer registry program by the Cancer Control Department and the breast cancer registry program by the Turkish Federation of Breast Diseases Societies (Türkiye Meme Hastalıkları Dernekleri Federasyonu-TMHDF), and introduction of Cancer Early Diagnosis, Screening, and Training Centers (Kanser Erken Tanı, Tarama ve Eğitim Merkezi-KETEM) for the application of community-based cancer screening programs. In addition to these, obvious shortcomings related to education, implementation, management and research issues were also determined, and policy and project proposals to address these issues were presented. Collaboration with relevant organizations in the implementation of these studies was supported. Conclusion Both the incidence and mortality rates of cancer are increasing in Turkey. The widespread deficiencies in population-based screening and in effective treatment lead to an increase in delay in diagnosis and mortality. Despite improvements in data recording, screening and treatment over the last 10 years, extensive, organized, population-based screening programs and fully equipped early diagnosis and treatment centers are required. Enhancement of basic cancer epidemiologic, translational, genetic and molecular research studies is essential in our country. Improvements on pain treatment and palliative care of patients with chronic and terminal cancer are also required. PMID:28331725

CD4 T-helper cell cytokine phenotypes and antibody response following tetanus toxoid booster immunization.

PubMed

Livingston, Kimberly A; Jiang, Xiaowen; Stephensen, Charles B

2013-04-30

Routine methods for enumerating antigen-specific T-helper cells may not identify low-frequency phenotypes such as Th2 cells. We compared methods of evaluating such responses to identify tetanus toxoid- (TT) specific Th1, Th2, Th17 and IL10(+) cells. Eight healthy subjects were given a TT booster vaccination. Blood was drawn before, 3, 7, 14, and 28days after vaccination and peripheral blood mononuclear cells (PBMC) were cultured for 7days with TT, negative control (diluent), and a positive control (Staphylococcus enterotoxin B [SEB]). Activation markers (CD25 and CD69) were measured after 44h (n=8), cytokines in supernatant after 3 and 7days, and intracellular cytokine staining (ICS) of proliferated cells (identified by dye dilution) after 7days (n=6). Vaccination increased TT-specific expression of CD25 and CD69 on CD3(+)CD4(+) lymphocytes, and TT-specific proliferation at 7, 14 and 28days post vaccination. Vaccination induced TT-specific Th1 (IFN-γ, TNF-α, and IL-2) Th2 (IL-13, IL-5, and IL-4), Th17 (IL-17A) and IL-10(+) cells as measured by ICS. TT-specific Th1 cells were the most abundant (12-15% of all TT-specific CD4(+) T-cells) while IL10(+) (1.8%) Th17 (1.1%) and Th2 cells (0.2-0.6%) were less abundant. TT-specific cytokine concentrations in PBMC supernatants followed the same pattern where a TT-specific IL-9 response was also seen. In conclusion, TT booster vaccination induced a broad T-helper cell response. This method of evaluating cytokine phenotypes may be useful in examining the impact of nutrition and environmental conditions on the plasticity of T-helper cell memory responses. Published by Elsevier B.V.

Altered Innate and Lymphocytic Immune Responses in Mouse Splenocytes Post-Flight

NASA Technical Reports Server (NTRS)

Hwang, ShenAn; Crucian, Brian E.; Sams, Clarence F.; Actor, Jeffrey K.

2011-01-01

Space flight is known to affect immune responses of astronauts and animals, decreasing lymphocytic responses to mitogenic stimuli, delayed typed hypersensitivity reactions, and T-cell activation. Despite changes in immune suppression, there are no reports of consistent adverse clinical events post flight. To further investigate the spectrum of affected immune responses, murine splenocytes were stimulated immediately post-shuttle flight (14 days on STS-135) with T-cell stimulators or toll-like receptor agonists. Comparisons were made to ground control splenocytes from age-matched mice. Cell phenotypes were assessed, as well as activation markers and associated cytokine production. The CD4+ population decreased with no concurrent decrease in CD8+ cells from shuttle mice post flight compared to ground controls. Regarding antigen presenting cell populations, the number of CD11c+ cells were slightly elevated post flight, compared to ground controls, with increased MHC Class I expression (I-A(sup b)) and no change in Class II expression (H-2K(sup b)). CD86+ populations were also significantly diminished. However, the decreased markers did not correlate with activity. Stimulation of splenocytes post flight showed significant increase in bead uptake, increased Class I expression, increased TNF-alpha and IL-6 production in response to TLR-2 (zymosan) and TLR-4 (LPS) agonists. While most activated (ConA or anti-CD3/anti-CD28) CD4+ cells showed markedly diminished responses (reduced IL-2 production), non-specific T cell responses to superantigen (SEA/SEB) increased post flight as determined by expression of early activation markers. Production of additional cytokines was also dysregulated postflight. Overall, persistent immune changes during space flight could represent unique clinical risks for exploration class missions. The consequences of pathogenic encounter remain an important concern that should be addressed.

Effects of the administration of Lactobacilli on body growth and on the metabolic profile in growing Maltese goat kids.

PubMed

Chiofalo, Vincenzo; Liotta, Luigi; Chiofalo, Biagina

2004-01-01

The aim of this study was to evaluate the effect of some lactobacilli on body growth and on the metabolic-nutritional status in growing goat kids. Twenty growing Maltese goat kids (10 Control and 10 Bios) were studied. The animals of the Bios group received a concentrate including 1 g x kg(-1) of SEB Bovino (spray-dried), Akron S.r.l., Italy, with non bacterial components: gum arabic, soybean meal, silicate alum of magnesium, and with bacterial components: 10(11) cfu kg(-1) each of Lactobacillus acidophilus, Lactobacillus salivarius, Lactobacillus reuteri. Monthly, bio-metric and weight evaluations were carried out on each animal and individual blood samples were taken. The Bios group showed the highest body weight (Control 19 vs. Bios 23 kg P < 0.001), anamorphosis (Control 71 vs. Bios 78 P < 0.05) and body proportion (Control 35 vs. Bios 41 P < 0.001) indices; the lowest levels of Non Esterified Fatty Acids (Control 0.778 vs. Bios 0.403 mmol L(-1) P < 0.001), triglycerides (Control 0.21 vs. Bios 0.18 mmol L(-1) P < 0.05), urea (Control 8.83 vs. Bios 7.65 mmol L(-1) P < 0.05) and the highest levels of Alkaline Phosphatase (Control 270 vs. Bios 851 U L(-1) P < 0.01) and Creatine Kinase (Control 173 vs. Bios 285 U L(-1) P < 0.01). The results testify to the better metabolic activity of the Bios group which achieved, at the end of the trial (7 months old), about 99% of the morphological development of the adult, therefore an adequate structure for mating and going into production within the first year of life.

A study of Staphylococcus aureusnasal carriage, antibacterial resistance and virulence factor encoding genes in a tertiary care hospital, Kayseri, Turkey.

PubMed

Oguzkaya-Artan, M; Artan, C; Baykan, Z; Sakalar, C; Turan, A; Aksu, H

2015-01-01

This study was to determine the virulence encoding genes, and the antibiotic resistance patterns of the Staphylococcus aureus isolates, which were isolated from the nasal samples of chest clinic patients. The nasal samples of the in-patients (431) and out-patients (1857) in Kayseri Training and Research Hospital's Chest Clinic, Kayseri, Turkey, were cultured on CHROMagar (Biolife, Italiana) S. aureus, and subcultured on sheep blood agar for the isolation of S. aureus. Disc diffusion method was used for antimicrobial susceptibility testing. The occurrence of the staphylococcal virulence encoding genes (enterotoksins [sea, seb, sec, see, seg, seh, sei, sej], fibronectin-binding proteins A, B [fnbA, fnbB], toxic shock syndrome toxin-1 [tst]) were detected by polymerase chain reaction. Forty-five of the 55 (81.8%) S. aureus isolates from inpatients, and 319 (90.6%) isolates from tested 352 out-patient's isolates were suspected to all the antibiotics tested. methicillin-resistant S. aureus (MRSA) was detected in 1.2% of S. aureus isolates. Rifampin, trimethoprim-sulfamethoxazole, clindamycin, erythromycin, gentamicin resistance rates were 1.2%, 1.7%, 2.0%, 8.8%, and 1.2%, respectively. The isolates were susceptible to teicoplanin and vancomycin. The genes most frequently found were tst (92.7%), seg (85.8%), sea (83.6%), fnbA (70.9%). There was no statistical significance detected between MRSA and mecA-negative S. aureus isolates in encoding genes distribution (P > 0.05). Our results show that virulence factor encoding genes were prevalent in patients with S. aureus carriage, whereas antibiotic resistance was low. These virulence determinants may increase the risk for subsequent invasive infections in carriers.

Antibiotic resistance and pathogenicity factors in Staphylococcus aureus isolated from mastitic Sahiwal cattle.

PubMed

Kumar, Ravinder; Yadav, B R; Singh, R S

2011-03-01

Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious problem in dairy animals suffering from mastitis. In the present study, the distribution of mastitic MRSA and antibiotic resistance was studied in 107 strains of S. aureus isolated from milk samples from 195 infected udders. The characterizations pathogenic factors (adhesin and toxin genes) and antibiotic susceptibility of isolates were carried out using gene amplification and disc diffusion assays, respectively. A high prevalence of MRSA was observed in the tested isolates (13.1%). The isolates were also highly resistant to antibiotics, i.e. 36.4% were resistant to streptomycin, 33.6% to oxytetracycline, 29.9% to gentamicin and 26.2% each to chloramphenicol, pristinomycin and ciprofloxacin. A significant variation in the expression of pathogenic factors (Ig, coa and clf) was observed in these isolates. The overall distribution of adhesin genes ebp, fib, bbp, fnbB, cap5, cap8, map and cna in the isolates was found to be 69.1, 67.2, 6.5, 20.5, 60.7, 26.1, 81.3 and 8.4%, respectively. The presence of fib, fnbB, bbp and map genes was considerably greater in MRSA than in methicillin-susceptible S. aureus (MSSA) isolates. The proportions of toxin genes, namely, hlb, seb, sec, sed, seg and sei, in the isolates were found to be 94.3, 0.9, 8.4, 0.9, 10.2 and 49.5%, respectively. The proportions of agr genes I, II, III and IV were found to be 39.2, 27.1, 21.5 and 12.1%, respectively. A few isolates showed similar antibiotic-resistance patterns, which could be due to identical strains or the dissemination of the same strains among animals. These findings can be utilized in mastitis treatment programmes and antimicrobials strategies in organized herd.

Occurrence of Salmonella, Listeria monocytogenes, and enterotoxigenic Staphylococcus in goat milk from small and medium-sized farms located in Minas Gerais State, Brazil.

PubMed

Cavicchioli, V Q; Scatamburlo, T M; Yamazi, A K; Pieri, F A; Nero, L A

2015-12-01

Consumption of goat milk has been increasing due to its nutritional characteristics and health benefits. Therefore, assessment of the presence of foodborne pathogens in this product is critical to ensure its safety to consumers. The present study aimed to identify common foodborne pathogens in raw goat milk. Fifty-three samples of raw goat milk from 11 farms were collected and cultured for the presence of Salmonella spp. and Listeria monocytogenes, as well as for enumeration and isolation of coagulase-positive and coagulase-negative Staphylococcus (CPS and CNS, respectively). All samples tested negative for Salmonella spp. and L. monocytogenes. The CPS counts in raw goat milk samples were predominantly less than 2 log cfu/mL (n=39), and CNS counts were predominantly higher than 3 log cfu/mL (n=42). Based on Staphylococcus counts, 51 isolates were selected (CPS=26; CNS=25) and tested by PCR for the presence of classic enterotoxin-encoding genes (sea, seb, sec, sed, and see). Only 3 isolates (CPS=2, CNS=1) were negative for all enterotoxin-encoding genes tested, and the genotype sec and see was the most frequent (n=16), followed by sea, sec, and see (n=13) and sec (n=13); sed was not detected in any isolate. The frequencies of enterotoxin-encoding genes for CPS and CNS were similar, demonstrating the equivalence of both groups in harboring these virulent markers. These results suggest that Salmonella and L. monocytogenes are not frequent contaminants of raw goat milk, but that Staphylococcus spp. that are capable of producing enterotoxins are prevalent; therefore, consumers of raw goat milk and products made from raw milk are at risk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Short communication: Pasteurization as a means of inactivating staphylococcal enterotoxins A, B, and C in milk.

PubMed

Necidova, Lenka; Bogdanovicova, Katerina; Harustiakova, Danka; Bartova, Katerina

2016-11-01

Our aim was to assess the effect of pasteurization temperature on inactivation of staphylococcal enterotoxins (SE). Milk samples were inoculated with log 4.38 to 5.18cfu/mL of 40 different Staphylococcus aureus strains having the ability to produce types A, B, or C SE and incubated at 37°C for 24h to develop SE. This incubation was followed by heat treatment for 15 s at 72, 85, and 92°C. Samples were analyzed for Staph. aureus count by plate method and, specifically, for SE presence. An enzyme-linked immunofluorescent assay on a MiniVIDAS analyzer (bioMérieux, Marcy l'Étoile, France) was used to detect SE, which were determined semiquantitatively based on test values. The Staph. aureus count in milk before pasteurization did not affect the amount of SE. Before pasteurization, SEB was detected in the lowest amount compared with other SE types. Staphylococcal enterotoxins were markedly reduced with pasteurization and inactivated at pasteurization temperatures to an extent depending on the amount in the sample before pasteurization. After pasteurization at 72°C, SE were detected in 87.5% of samples (35/40), after pasteurization at 85°C in 52.5% of samples (21/40), and after pasteurization at 92°C in 45.0% of samples (18/40). We determined that SE may still persist in milk even when Staph. aureus bacteria are inactivated through pasteurization. Although pasteurization may partially inactivate SE in milk, a key measure in the prevention of staphylococcal enterotoxicosis linked to pasteurized milk consumption is to avoid any cold chain disruption during milk production and processing. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Behavior and enterotoxin production by coagulase negative Staphylococcus in cooked ham, reconstituted skimmed milk, and confectionery cream.

PubMed

Oliveira, Ana Maria; Miya, Norma Teruko Nago; Sant'Ana, Anderson S; Pereira, José Luiz

2010-09-01

In this study, the behavior and enterotoxin production by 10 different coagulase negative Staphylococcus (CNS) strains inoculated in cooked ham, reconstituted skimmed milk, and confectionery cream in the presence or absence of background microbiota have been investigated. After inoculation (103 CFU/g), foods were incubated at 25, 30, and 37 °C and aerobic mesophilic and CNS counts were carried out at 12, 24, 48, and 72 h. Staphylococcal enterotoxins (SE) detection was performed by SET-RPLA (Oxoid, Basingstoke, U.K.) and mini-Vidas® (bioMérieux, La Balme les Grottes, France). CNS counts increased during incubation and approached 10⁶ to 10⁷ CFU/g after 12 h at 37 °C in the 3 foods studied. At 25 °C, counts reached 10⁶ to 10⁷ CFU/g only after 24 to 48 h. The interference of background microbiota on CNS behavior was only observed when they grew in sliced cooked ham, which presented a high initial total count (10⁵ CFU/g). Significantly higher counts of CNS isolated from raw cow's milk in comparison with food handlers isolates were found in reconstituted milk and confectionery cream. Although CNS strains were able to produce SEA, SEB, and SED in culture media, in foods, in the presence or absence of background microbiota S. chromogenes LE0598 was the only strain able to produce SEs. Despite the scarcity of reports on CNS involvement with foodborne disease outbreaks, the results found here support the CNS growth and SE production in foods even in the presence of background microbiota and may affect food safety.

The prevalence of antimicrobial resistance and carriage of virulence genes in Staphylococcus aureus isolated from food handlers in Kuwait City restaurants

PubMed Central

Udo, Edet E; Al-Mufti, Siham; Albert, M John

2009-01-01

Background Staphylococcus aureus is a major cause of food poisoning due to their ability to produce enterotoxins which if ingested in sufficient amounts results in sickness. Food handlers carrying enterotoxin-producing S. aureus in their noses or hands can contaminate food leading to food poisoning. We characterized 200 S. aureus obtained from food handlers in different restaurants for antibacterial resistance and the carriage of virulence genes. Findings Susceptibility to antibacterial agents was determined by disk diffusion and Etest. PCR was used to detect genes for accessory gene regulator (agr); capsular polysaccharide (cap) 5 and 8, staphylococcal enterotoxins (SE), toxic shock syndrome toxin-1 (TSST-1) and Panton-Valentine leukocidin (PVL). Isolates were typed using pulsed-field gel electrophoresis. In total 185 (92.5%) of the 200 isolates expressed resistance to antibacterial agents. They were resistant to penicillin G (82.0%), tetracycline (19.0%), erythromycin (2.5%), clindamycin (2.0%), trimethoprim (7.5%), kanamycin (2.5%), streptomycin (1.5%), ciprofloxacin (1.5%), fusidic acid (1.0%) and cadmium acetate (68.0%). Seventy-six (38.0%) and 114 (57.0%) isolates had type 5 and type 8 capsular polysaccharides respectively. The agr types I, II and III alleles were detected in 50.5%, 20.0% and 23.5% of the isolates respectively. They contained genes for SEI (38.5%), SEG (24.0%), SEC (23.0%), SEB (12.5%), SEH (21.5%), SEA (11.0), SED (1.5%), SEE (1.5%), TSST-1 (4.0%) and PVL (9.0%). Conclusion This study revealed a high prevalence of antibacterial resistance and virulence determinants in S. aureus from food handlers in Kuwait restaurants justifying the screening of food handlers to detect and treat carriers and protect restaurant customers from staphylococcal food poisoning. PMID:19531224

Improving the Sensitivity and Functionality of Mobile Webcam-Based Fluorescence Detectors for Point-of-Care Diagnostics in Global Health.

PubMed

Rasooly, Reuven; Bruck, Hugh Alan; Balsam, Joshua; Prickril, Ben; Ossandon, Miguel; Rasooly, Avraham

2016-05-17

Resource-poor countries and regions require effective, low-cost diagnostic devices for accurate identification and diagnosis of health conditions. Optical detection technologies used for many types of biological and clinical analysis can play a significant role in addressing this need, but must be sufficiently affordable and portable for use in global health settings. Most current clinical optical imaging technologies are accurate and sensitive, but also expensive and difficult to adapt for use in these settings. These challenges can be mitigated by taking advantage of affordable consumer electronics mobile devices such as webcams, mobile phones, charge-coupled device (CCD) cameras, lasers, and LEDs. Low-cost, portable multi-wavelength fluorescence plate readers have been developed for many applications including detection of microbial toxins such as C. Botulinum A neurotoxin, Shiga toxin, and S. aureus enterotoxin B (SEB), and flow cytometry has been used to detect very low cell concentrations. However, the relatively low sensitivities of these devices limit their clinical utility. We have developed several approaches to improve their sensitivity presented here for webcam based fluorescence detectors, including (1) image stacking to improve signal-to-noise ratios; (2) lasers to enable fluorescence excitation for flow cytometry; and (3) streak imaging to capture the trajectory of a single cell, enabling imaging sensors with high noise levels to detect rare cell events. These approaches can also help to overcome some of the limitations of other low-cost optical detection technologies such as CCD or phone-based detectors (like high noise levels or low sensitivities), and provide for their use in low-cost medical diagnostics in resource-poor settings.

Improving the Sensitivity and Functionality of Mobile Webcam-Based Fluorescence Detectors for Point-of-Care Diagnostics in Global Health

PubMed Central

Rasooly, Reuven; Bruck, Hugh Alan; Balsam, Joshua; Prickril, Ben; Ossandon, Miguel; Rasooly, Avraham

2016-01-01

Resource-poor countries and regions require effective, low-cost diagnostic devices for accurate identification and diagnosis of health conditions. Optical detection technologies used for many types of biological and clinical analysis can play a significant role in addressing this need, but must be sufficiently affordable and portable for use in global health settings. Most current clinical optical imaging technologies are accurate and sensitive, but also expensive and difficult to adapt for use in these settings. These challenges can be mitigated by taking advantage of affordable consumer electronics mobile devices such as webcams, mobile phones, charge-coupled device (CCD) cameras, lasers, and LEDs. Low-cost, portable multi-wavelength fluorescence plate readers have been developed for many applications including detection of microbial toxins such as C. Botulinum A neurotoxin, Shiga toxin, and S. aureus enterotoxin B (SEB), and flow cytometry has been used to detect very low cell concentrations. However, the relatively low sensitivities of these devices limit their clinical utility. We have developed several approaches to improve their sensitivity presented here for webcam based fluorescence detectors, including (1) image stacking to improve signal-to-noise ratios; (2) lasers to enable fluorescence excitation for flow cytometry; and (3) streak imaging to capture the trajectory of a single cell, enabling imaging sensors with high noise levels to detect rare cell events. These approaches can also help to overcome some of the limitations of other low-cost optical detection technologies such as CCD or phone-based detectors (like high noise levels or low sensitivities), and provide for their use in low-cost medical diagnostics in resource-poor settings. PMID:27196933

Enterotoxin-encoding genes in Staphylococcus spp. from bulk goat milk.

PubMed

Lyra, Daniele G; Sousa, Francisca G C; Borges, Maria F; Givisiez, Patrícia E N; Queiroga, Rita C R E; Souza, Evandro L; Gebreyes, Wondwossen A; Oliveira, Celso J B

2013-02-01

Although Staphylococcus aureus has been implicated as the main Staphylococcus species causing human food poisoning, recent studies have shown that coagulase-negative Staphylococcus could also harbor enterotoxin-encoding genes. Such organisms are often present in goat milk and are the most important mastitis-causing agents. Therefore, this study aimed to investigate the occurrence of enterotoxin-encoding genes among coagulase-positive (CoPS) and coagulase-negative (CoNS) staphylococci isolated from raw goat milk produced in the semi-arid region of Paraiba, the most important region for goat milk production in Brazil. Enterotoxin-encoding genes were screened in 74 staphylococci isolates (30 CoPS and 44 CoNS) by polymerase chain reaction targeting the genes sea, seb, sec, sed, see, seg, seh, and sei. Enterotoxin-encoding genes were found in nine (12.2%) isolates, and four different genes (sea, sec, seg, and sei) were identified amongst the isolates. The most frequent genes were seg and sei, which were often found simultaneously in 44.5% of the isolates. The gene sec was the most frequent among the classical genes, and sea was found only in one isolate. All CoPS isolates (n=7) harboring enterotoxigenic genes were identified as S. aureus. The two coagulase-negative isolates were S. haemolyticus and S. hominis subsp. hominis and they harbored sei and sec genes, respectively. A higher frequency of enterotoxin-encoding genes was observed amongst CoPS (23.3%) than CoNS (4.5%) isolates (p<0.05), reinforcing the importance of S. aureus as a potential foodborne agent. However, the potential risk posed by CoNS in goat milk should not be ignored because it has a higher occurrence in goat milk and enterotoxin-encoding genes were detected in some isolates.

Defeating anisotropy in material extrusion 3D printing via materials development

NASA Astrophysics Data System (ADS)

Torrado Perez, Angel Ramon

Additive Manufacturing technologies has been in continuous development for more than 35 years. Specifically, the later denominated Material Extrusion Additive Manufacturing (MEAM), was first developed by S. Scott Crump around 1988 and trademarked later as Fused Deposition Modeling (FDM). Although all of these technologies have been around for a while, it was not until recently that they have been more accessible to everyone. Today, the market of 3D printers covers all ranges of price, from very specialized, heavy and expensive machines, to desktop printers of only a few cubic inches in volume. Until recently, FDM technology had remained somewhat stagnant in terms of developments; however, with the new market boom, scholars and hobbyists have opened new doors for investigation in this area. The technology is now better understood from a software, mechanical, electrical and not less important, materials point of view. The current availability of materials for MEAM is very broad: PLA (Polylactic Acid), ABS (Acrylonitrile Butadiene Styrene), PC (Polycarbonate), PEEK (Polyether Ether Ketone), nylon, polyurethanes, and many others. Even so, these are all materials that were used before for other technologies, adapted but not specifically developed for MEAM. The processes that take place during the production of a part are currently not very well understood, and the final properties exhibited are long ways away from reaching the potential of more traditional manufacturing techniques. Due to the nature of the process, all the material properties always display a certain level of anisotropy. The research covered in these pages aims to shed some light on understanding the different mechanics taking place during the extrusion process of additive manufacturing. The development of new materials for MEAM has been explored. Several blends and composites have been developed, and their tensile properties and fracture mechanics evaluated. The blending of different combinations of ABS, UHMWPE (Ultra High Molecular Weight Polyethylene) and SEBS (Styrene Ethylene Butylene Styrene) were further examined due to the potential they demonstrated as low anisotropic materials in terms of strength. Also, the geometrical influence of different standard tensile specimens was studied. The development of materials that lead to lowered anisotropy on the strength of 3D printed parts has been successfully demonstrated, and alternative methodologies for the evaluation of anisotropic characteristics has been proposed as well. The present work shows the beginning to a better understanding of the mechanics taking place during the fusion of deposited material in MEAM.

Comprehensive Astronaut Immune Assessment Following a Short-Duration Space Flight

NASA Technical Reports Server (NTRS)

Crucian, Brian; Stowe, Raymond; Yetman, Deborah; Pierson, Duane; Sams, Clarence

2006-01-01

Immune system dysregulation has been demonstrated to occur during spaceflight and has the potential to cause serious health risks to crewmembers participating in exploration class missions. As a part of an ongoing NASA flight experiment assessing viral immunity (DSO-500), a generalized immune assessment was performed on 3 crewmembers who participated in the recent STS-114 Space Shuttle mission. The following assays were performed: (1) comprehensive immunophenotype analysis; (2) T cell function/intracellular cytokine profiles; (4) secreted Th1/Th2 cytokine profiles via cytometric bead array. Immunophenotype analysis included a leukocyte differential, lymphocyte subsets, T cell subsets, cytotoxic/effector CD8+ T cells, memory/naive T cell subsets and constitutively activated T cells. Study timepoints were L-180, L-65, L-10, R+0, R+3 and R+14. Detailed data are presented in the poster text. As expected from a limited number of human subjects, data tended to vary with respect to most parameters. Specific post-flight alterations were as follows (subject number in parentheses): Granulocytosis (2/3), reduced NK cells (3/3), elevated CD4/CD8 ratio (3/3), general CD8+ phenotype shift to a less differentiated phenotype (3/3), elevated levels of memory CD4+ T cells (3/3), loss of L-selectin on T cell subsets (3/3), increased levels of activated T cells (2/3), reduced IL-2 producing T cell subsets (3/3), levels of IFNg producing T cells were unchanged. CD8+ T cell expression of the CD69 activation markers following whole blood stimulation with SEA+SEB were dramatically reduced postflight (3/3), whereas other T cell function assessments were largely unchanged. Cytometric bead array assessment of secreted T cell cytokines was performed, following whole blood stimulation with either CD3/CD28 antibodies or PMA+ionomycin for 48 hours. Specific cytokines assessed were IFNg, TNFa, IL-2, IL-4, IL-5, IL-10. Following CD3/CD28 stimulation, all three crewmembers had a mission-associated reduction in the levels of secreted IFNg. One crewmember had a post-flight inversion in the IFNg/IL-10 ratio postflight, which trended back to baseline by R+14. Detailed cytokine data are presented in the poster text. This testing regimen was designed to correlate immunophenotype changes (thought to correspond to specific in-vivo immune responses or pathogenesis), against altered leukocyte function and cytokine profiles. In-flight studies are required to determine if post-flight alterations are reflective of the in-flight condition, or are a response to landing and readaptation.

Dynamical and Chemical Tracers in Jupiter's Troposphere and Stratosphere from the Earth-Based Infrared Juno Support Campaign

NASA Astrophysics Data System (ADS)

Melin, H.; Fletcher, L. N.; Donnelly, P. T.; Greathouse, T.; Lacy, J.; Orton, G.; Giles, R.; Sinclair, J. A.; Irwin, P. G.

2017-12-01

The three-dimensional distribution of temperatures, chemical tracers and aerosol opacity in Jupiter's troposphere and stratosphere can be characterised by inverting spectra and images taken the mid-infrared. We present NASA IRTF TEXES, Gemini TEXES and VLT VISIR 5-25 µm spectral maps of Jupiter obtained in the run-up, and during the Juno mission at Jupiter, providing crucial observations in the mid-infrared, a wavelength region not covered by Juno's suite of instruments. The NASA IRTF TEXES observations form a long baseline of spectroscopic maps between 2012 and 2017, providing temporal context for Juno's observations. Using this dataset we investigate the zonal abundance distribution of acetylene and ethane, and how these change over time. Using the methane channel, we can retrieve the vertical temperature profile between 1 and 10 mbar and track a full cycle of Jupiter's equatorial stratospheric oscillation. We confirm that the acetylene abundance decreases towards the pole, whilst ethane increases towards the pole. We find that the data supports the hypothesis that acetylene is asymmetric about the equator, and varies with time in response to short-lived dynamical changes. We suggest that this asymmetry, which changes over time, is driven by stratospheric wave activity. Conversely, ethane appears to be symmetric about the equator, and does not vary with time. The stark difference between acetylene and ethane is likely linked to the two species having very different chemical life-times and vertical abundance gradients. Gemini TEXES spectral mapping in March 2017 reveals - in addition to temperatures - the spatial distribution of ammonia, phosphine and upper tropospheric aerosols at high spatial resolution. We confirm the equatorial NH3 enhancement observed by Juno, and investigate the distribution of these dynamical tracers in the vicinity of NEB hotspots, an SEB plume outbreak, and the Great Red Spot.

Staphylococcus aureus strains associated with food poisoning outbreaks in France: comparison of different molecular typing methods, including MLVA

PubMed Central

Roussel, Sophie; Felix, Benjamin; Vingadassalon, Noémie; Grout, Joël; Hennekinne, Jacques-Antoine; Guillier, Laurent; Brisabois, Anne; Auvray, Fréderic

2015-01-01

Staphylococcal food poisoning outbreaks (SFPOs) are frequently reported in France. However, most of them remain unconfirmed, highlighting a need for a better characterization of isolated strains. Here we analyzed the genetic diversity of 112 Staphylococcus aureus strains isolated from 76 distinct SFPOs that occurred in France over the last 30 years. We used a recently developed multiple-locus variable-number tandem-repeat analysis (MLVA) protocol and compared this method with pulsed field gel electrophoresis (PFGE), spa-typing and carriage of genes (se genes) coding for 11 staphylococcal enterotoxins (i.e., SEA, SEB, SEC, SED, SEE, SEG, SEH, SEI, SEJ, SEP, SER). The strains known to have an epidemiological association with one another had identical MLVA types, PFGE profiles, spa-types or se gene carriage. MLVA, PFGE and spa-typing divided 103 epidemiologically unrelated strains into 84, 80, and 50 types respectively demonstrating the high genetic diversity of S. aureus strains involved in SFPOs. Each MLVA type shared by more than one strain corresponded to a single spa-type except for one MLVA type represented by four strains that showed two different-but closely related-spa-types. The 87 enterotoxigenic strains were distributed across 68 distinct MLVA types that correlated all with se gene carriage except for four MLVA types. The most frequent se gene detected was sea, followed by seg and sei and the most frequently associated se genes were sea-seh and sea-sed-sej-ser. The discriminatory ability of MLVA was similar to that of PFGE and higher than that of spa-typing. This MLVA protocol was found to be compatible with high throughput analysis, and was also faster and less labor-intensive than PFGE. MLVA holds promise as a suitable method for investigating SFPOs and tracking the source of contamination in food processing facilities in real time. PMID:26441849

Circulating CD4+CXCR5+ T cells contribute to proinflammatory responses in multiple ways in coronary artery disease.

PubMed

Ding, Ru; Gao, Wenwu; He, Zhiqing; Wu, Feng; Chu, Yang; Wu, Jie; Ma, Lan; Liang, Chun

2017-11-01

Coronary artery disease (CAD) is a common subtype of cardiovascular disease. The major contributing event is atherosclerosis, which is a progressive inflammatory condition resulting in the thickening of the arterial wall and the formation of atheromatous plaques. Recent evidence suggests that circulating CD4 + CXCR5 + T cells can contribute to inflammatory reactions. In this study, the frequency, phenotype, and function of circulating CD4 + CXCR5 + T cells in CAD patients were examined. Data showed that circulating CD4 + CXCR5 + T cells in CAD patients were enriched with a PD-1 + CCR7 - subset, which was previously identified as the most potent in B cell help. The CD4 + CXCR5 + T cells in CAD patients also secreted significantly higher levels of IFN-γ, IL-17A, and IL-21 than those from healthy controls. Depleting the PD-1 + population significantly reduced the cytokine secretion. Interestingly, the CD4 + CXCR5 + PD-1 - T cells significantly upregulated PD-1 following anti-CD3/CD28 or SEB stimulation. CD4 + CXCR5 + T cells from CAD patients also demonstrated more potent capacity to stimulate B cell inflammation than those from healthy individuals. The phosphorylation of STAT1 and STAT3 were significantly higher in B cells incubated with CD4 + CXCR5 + T cells from CAD than controls. The IL-6 and IFN-γ expression were also significantly higher in B cells incubated with CD4 + CXCR5 + T cells from CAD. Together, this study demonstrated that CAD patients presented a highly activated CD4 + CXCR5 + T cell subset that could contribute to proinflammatory responses in multiple ways. The possibility of using CD4 + CXCR5 + T cells as a therapeutic target should therefore be examined in CAD patients. Copyright © 2017 Elsevier B.V. All rights reserved.

L1 adhesion molecule on mouse leukocytes: regulation and involvement in endothelial cell binding.

PubMed

Hubbe, M; Kowitz, A; Schirrmacher, V; Schachner, M; Altevogt, P

1993-11-01

L1 is a cell surface glycoprotein of the immunoglobulin superfamily which was initially shown to mediate adhesion between neural cells. Recently we have reported that L1 is expressed by bone marrow cells and the majority of mature lymphocytes (Kowitz et al., Eur. J. Immunol. 1992. 22: 1199-1205). To analyze the function of L1 on leukocytes we studied its regulation following cell activation. In vitro activation of B lymphocytes with lipopolysaccharide or T lymphocytes with phorbol 12-myristate 13-acetate/Ca2+ ionophore, concanavalin A or anti-CD3 monoclonal antibody as well as in vivo activation of V beta 8+ T cells with staphylococcal enterotoxin B (SEB) revealed a down-regulation of L1 within 48 h. A rapid loss of L1 expression was seen when mouse neutrophils were activated with PMA alone. This rapid loss paralleled the shedding of L-selectin. We also studied a possible role of L1 in the binding of leukocytes to endothelial cells. ESb-MP lymphoma cells with a high expression of L1 (L1hi) could bind to bend3 endothelioma cells without prior activation with inflammatory cytokines. The interaction was inhibited by anti-L1 antibodies. In contrast, ESb-MP cells with low L1 expression (L1lo) were only marginally bound. Latex beads coated with affinity-isolated L1 antigen were also able to bind to the endothelioma cells in a specific fashion. The binding of ESb-MP lymphoma cells required Ca2+ and Mg2+ ions and was sensitive to cold temperature. Since the endothelioma cells did not express L1 the binding mechanism studied here is distinct from the established L1-L1 homotypic interaction. It is possible that the novel L1-mediated adhesion pathway involves an unidentified ligand and could play a role in leukocyte migration.

Staphylococcus argenteus from rabbits in Thailand.

PubMed

Indrawattana, Nitaya; Pumipuntu, Natapol; Suriyakhun, Nawarat; Jangsangthong, Arunee; Kulpeanprasit, Suphang; Chantratita, Narisara; Sookrung, Nitat; Chaicumpa, Wanpen; Buranasinsup, Shutipen

2018-06-21

Staphylococcus argenteus, a novel species of the genus Staphylococcus or a member of the S. aureus complex, is closely related to S. aureus and is usually misidentified. In this study, the presence of S. argenteus in isolated S. aureus was investigated in 67 rabbits with abscess lesions during 2014-2016. Among 19 S. aureus complex isolates, three were confirmed to be S. argenteus by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, nonribosomal peptide synthetase gene amplification, and multilocus sequence type. All S. aureus complex isolates, including the S. aureus isolates, were examined for their antimicrobial resistance phenotype by disk diffusion and for their resistance genotype by PCR assays. Among the S. argenteus isolates, one was susceptible to all antimicrobial drugs and the other two were resistant to penicillin and doxycycline. In contrast, most S. aureus isolates were resistant to penicillin (37.5%), and gentamicin (12.5%). Moreover, S. aureus isolates harbored the blaZ, mecA, aacA-aphD, and mrs(A) as well as mutations of gyrA and grlA, but S. argenteus isolates carried solely the blaZ. S. argenteus isolates were investigated for enterotoxin (sea-sed) and virulence genes by PCR. One isolate carried sea, sec, and sed, whereas the other two isolates carried only sea or sed. No isolate carried seb and see. All three S. argenteus isolates carried hla, hlb, and clfA, followed by pvl, whereas coa, spa (IgG-binding region), and spa (x region) were not detected in the three isolates. This paper presents the first identification of S. argenteus from rabbits in Thailand. S. argenteus might be pathogenic because the isolates carried virulence genes. Moreover, antimicrobial resistance was observed. Investigations of this new bacterial species should be conducted in other animal species as well as in humans. © 2018 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

Four-Year Cost-effectiveness of Cognitive Behavior Therapy for Preventing First-episode Psychosis: The Dutch Early Detection Intervention Evaluation (EDIE-NL) Trial.

PubMed

Ising, Helga K; Lokkerbol, Joran; Rietdijk, Judith; Dragt, Sara; Klaassen, Rianne M C; Kraan, Tamar; Boonstra, Nynke; Nieman, Dorien H; van den Berg, David P G; Linszen, Don H; Wunderink, Lex; Veling, Wim; Smit, Filip; van der Gaag, Mark

2017-03-01

This study aims to evaluate the long-term cost-effectiveness of add-on cognitive behavior therapy (CBT) for the prevention of psychosis for individuals at ultrahigh risk (UHR) of psychosis. The Dutch Early Detection and Intervention randomized controlled trial was used, comparing routine care (RC; n = 101) with routine care plus CBT for UHR (here called CBTuhr; n = 95). A cost-effectiveness analysis was conducted with treatment response (defined as proportion of averted transitions to psychosis) as an outcome and a cost-utility analysis with quality-adjusted life years (QALYs) gained as a secondary outcome. The proportion of averted transitions to psychosis was significantly higher in the CBTuhr condition (with a risk difference of 0.122; b = 1.324, SEb = 0.017, z = 7.99, P < 0.001). CBTuhr showed an 83% probability of being more effective and less costly than RC by -US$ 5777 (savings) per participant. In addition, over the 4-year follow-up period, cumulative QALY health gains were marginally (but not significantly) higher in CBTuhr than for RC (2.63 vs. 2.46) and the CBTuhr intervention had a 75% probability of being the superior treatment (more QALY gains at lower costs) and a 92% probability of being cost-effective compared with RC at the Dutch threshold value (US$ 24 560; €20 000 per QALY). Add-on preventive CBTuhr had a high likelihood (83%) of resulting in more averted transitions to psychosis and lower costs as compared with RC. In addition, the intervention had a high likelihood (75%) of resulting in more QALY gains and lower costs as compared to RC. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com

Filarial infection modulates the immune response to Mycobacterium tuberculosis through expansion of CD4+ IL-4 memory T cells

PubMed Central

Chatterjee, Soumya; Clark, Carolyn E.; Lugli, Enrico; Roederer, Mario; Nutman, Thomas B.

2015-01-01

Exaggerated CD4+T helper 2-specific cytokine producing memory T cell responses developing concomitantly with a T helper1 response might have a detrimental role in immunity to infection caused by Mycobacterium tuberculosis (Mtb). To assess the dynamics of antigen (Ag)-specific memory T cell compartments in the context of filarial infection we used multiparameter flow cytometry on PBMCs from 25 microfilaremic filarial -infected (Inf) and 14 filarial-uninfected (Uninf) subjects following stimulation with filarial (BmA) or with the Mycobacterium tuberculosis (Mtb)-specific Ag CFP10. Our data demonstrated that the Inf group not only had a marked increase in BmA-specific CD4+IL-4+ cells (Median net frequency compared to baseline (Fo)=0.09% vs. 0.01%, p=0.038) but also to CFP10 (Fo =0.16% vs. 0.007%, p=0.04) and Staphylococcal Enterotoxin B (SEB) (Fo =0.49% vs. 0.26%, p=0.04). The Inf subjects showed a BmA-specific expansion of CD4+CD45RO+IL-4+ producing central memory (TCM, CD45RO+CCR7+CD27+) (Fo =1.1% vs. 0.5%, p=0.04) as well as effector memory (TEM CD45RO+CCR7-CD27-) (Fo =1.5% vs. 0.2%, p=0.03) with a similar but non-significant response to CFP10. In addition, there was expansion of CD4+ IL-4+ CD45RA+ CCR7+CD27+ (naïve-like) in Inf individuals compared to Uninf subjects. Among Inf subjects with definitive latent tuberculosis , there were no differences in frequencies of IL-4 producing cells within any of the memory compartments compared to the Uninf group. Our data suggest that filarial infection induces antigen-specific, exaggerated IL-4 responses in distinct T cell memory compartments to Mtb-specific antigens, which are attenuated in subjects who are able to mount a delayed type hypersensitivity reaction to Mtb. PMID:25667413

Acute responses to opioidergic blockade as a biomarker of hedonic eating among obese women enrolled in a mindfulness-based weight loss intervention trial

PubMed Central

Mason, Ashley E.; Lustig, Robert H.; Brown, Rashida R.; Acree, Michael; Bacchetti, Peter; Moran, Patricia J.; Dallman, Mary; Laraia, Barbara; Adler, Nancy

2015-01-01

There are currently no commonly used or easily accessible ‘biomarkers’ of hedonic eating. Physiologic responses to acute opioidergic blockade, indexed by cortisol changes and nausea, may represent indirect functional measures of opioid-mediated hedonic eating drive and predict weight loss following a mindfulness-based intervention for stress eating. In the current study, we tested whether cortisol and nausea responses induced by oral ingestion of an opioidergic antagonist (naltrexone) correlated with weight and self-report measures of hedonic eating and predicted changes in these measures following a mindfulness-based weight loss intervention. Obese women (N=88; age=46.7±13.2 years; BMI=35.8±3.8) elected to complete an optional sub-study prior to a 5.5-month weight loss intervention with or without mindfulness training. On two separate days, participants ingested naltrexone and placebo pills, collected saliva samples, and reported nausea levels. Supporting previous findings, naltrexone-induced cortisol increases were associated with greater hedonic eating (greater food addiction symptoms and reward-driven eating) and less mindful eating. Among participants with larger cortisol increases (+1 SD above mean), mindfulness participants (relative to control participants) reported greater reductions in food addiction symptoms, b=−0.95, SE(b=0.40, 95% CI [−1.74, −0.15], p=.021. Naltrexone-induced nausea was marginally associated with reward-based eating. Among participants who endorsed naltrexone-induced nausea (n=38), mindfulness participants (relative to control participants) reported greater reductions in food addiction symptoms, b=−1.00, 95% CI [−1.85, −0.77], p=.024, and trended toward reduced reward-based eating, binge eating, and weight, post-intervention. Single assessments of naltrexone-induced cortisol increases and nausea responses may be useful time- and cost-effective biological markers to identify obese individuals with greater opioid-mediated hedonic eating drive who may benefit from weight loss interventions with adjuvant mindfulness training that targets hedonic eating. PMID:25931433

Communities of practice in life sciences and the need for brokering

PubMed Central

Tierney, Anne

2016-01-01

Etienne Wenger’s work on communities of practice is influential in teaching and learning in higher education. A core work of many postgraduate certificate in teaching and learning (PGCert) courses for new lecturers, it is studied, in the main, as a means to understand how to support and encourage students to achieve more effective learning. Communities of practice can also be applied to academics. In the context of the Research Excellence Framework (REF) and its predecessors, the gulf between research-focused and teaching-Focused academics in life sciences has widened, so that in many institutions, these two groups have evolved into two distinct communities of practice; one whose priority is disciplinary research, the other’s learning and teaching. However, in 2015, the UK government announced that a Teaching Excellence Framework (TEF) would be introduced into higher education in England, as early as 2017. While the exact details of TEF remain unclear, it is certain that “excellence” and “student satisfaction” will be high on the agenda. It is vital, therefore, that the two communities of practice, research-focused and teaching-focused, find ways to come together in order to ensure high quality teaching and learning. Wenger proposes that this can be done through the process of “brokering”, which allows expertise from both communities of practice to cross from one to the other, strengthening both. This should be encouraged at departmental and institutional level, but another vital origin of brokering can be forged at a(n) (inter)national level at meetings such as the SEB Annual Conference, where teaching-focused academics have the opportunity to mix with research-active colleagues. While this paper is informed by recent and current events in the UK Higher Education sector, it is of interest to academics who work in an environment where research and teaching have become separate to any extent. PMID:26998239

Lymphocyte Redox Imbalance and Reduced Proliferation after a Single Session of High Intensity Interval Exercise.

PubMed

Tossige-Gomes, Rosalina; Costa, Karine Beatriz; Ottone, Vinícius de Oliveira; Magalhães, Flávio de Castro; Amorim, Fabiano Trigueiro; Rocha-Vieira, Etel

2016-01-01

This study investigated whether an acute session of high-intensity interval training (HIIT) is sufficient to alter lymphocyte function and redox status. Sixteen young healthy men underwent a HIIT session on a cycloergometer, consisting of eight bouts of 1 min at 90-100% of peak power, with 75 seconds of active recovery at 30 W between bouts. Venous blood was collected before, immediately after, and 30 minutes after the HIIT session. In response to Staphylococcus aureus superantigen B (SEB) stimulation, lymphocyte proliferation decreased and the IL-2 concentration increased after the HIIT session. However, the HIIT session had no effect on lymphocyte proliferation or IL-2 response to phytohemagglutinin stimulation. The HIIT session also induced lymphocyte redox imbalance, characterized by an increase in the concentration of thiobarbituric acid reactive substances and a decrease in the activity of the antioxidant enzyme catalase. Lymphocyte viability was not affected by the HIIT session. The frequencies of CD25+ and CD69+ T helper and B lymphocytes in response to superantigen stimulation were lower after exercise, suggesting that superantigen-induced lymphocyte activation was reduced by HIIT. However, HIIT also led to a reduction in the frequency of CD4+ and CD19+ cells, so the frequencies of CD25+ and CD69+ cells within the CD4 and CD19 cell populations were not affected by HIIT. These data indicate that the reduced lymphocyte proliferation observed after HIIT is not due to reduced early lymphocyte activation by superantigen. Our findings show that an acute HIIT session promotes lymphocyte redox imbalance and reduces lymphocyte proliferation in response to superantigenic, but not to mitogenic stimulation. This observation cannot be explained by alteration of the early lymphocyte activation response to superantigen. The manner in which lymphocyte function modulation by an acute HIIT session can affect individual immunity and susceptibility to infection is important and requires further investigation.

Exotoxin diversity of Staphylococcus aureus isolated from milk of cows with subclinical mastitis in Central Russia.

PubMed

Fursova, K K; Shchannikova, M P; Loskutova, I V; Shepelyakovskaya, A O; Laman, A G; Boutanaev, A M; Sokolov, S L; Artem'eva, O A; Nikanova, D A; Zinovieva, N A; Brovko, F A

2018-05-01

Mastitis, a major veterinary problem widespread in many regions, is caused mainly by Staphylococcus spp. However, there is no current reliable information about the role of Staphylococcus aureus and their toxins in the development of mastitis in cows in the territory of the Russian Federation. The aim of this investigation was to determine the profile of exotoxins of S. aureus from cow milk from farms of Central Russia. A total of 60 isolates of S. aureus were obtained from milk samples of cows with the subclinical form of mastitis. The exotoxin genes were identified using 2 types of PCR assays. The diversity of enterotoxin genes was studied by multiplex PCR. The percentage occurrence of enterotoxin genes was as follows: sea, 53.3%; seb, 3.3%; sec, 50%; sed, 4%; see, 46.6%; seg, 70%; sei, 10%; selp, 3.3%; and tsst1, 1.6%. The seh gene was not detected. The genes of pore-forming toxins and phenol-soluble modulins were identified by singleplex PCR and consisted of the following: hlA, 70%; lucS, 46.6%; psmA, 81.6%; psmB, 95%; and hld, 78.3%. The most abundant genes were psm (psmB, 95%), which codes for pore-forming toxins, and seg (70%), which codes for enterotoxins. The production of some enterotoxins in bacterial culture medium was detected by ELISA. The level of toxin production was near 1 ng/mL for SEA, SEE, SEG, SEI, SELP, and TSST-1 and reached a maximal level of 18 ng/mL for SEE. In the present work, we show that subclinical mastitis in cows is associated with S. aureus in the central region of the Russian Federation. Most of the isolates containing enterotoxin genes also had cytotoxin genes. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Investigation of a Staphylococcal Food Poisoning Outbreak from a Chantilly Cream Dessert, in Umbria (Italy)

PubMed Central

Gallina, Silvia; Nia, Yacine; Auvray, Frédéric; Primavilla, Sara; Guidi, Fabrizia; Pierucci, Benedetta; Graziotti, Catia; Decastelli, Lucia; Scuota, Stefania

2017-01-01

Abstract On August 28, 2015, a staphylococcal food poisoning outbreak occurred in Umbria, Italy, affecting 24 of the 42 customers who had dinner at a local restaurant. About 3 h after ingesting a variety of foods, the customers manifested gastrointestinal symptoms. Within 24 h of notification from the hospital emergency department, Sanitary Inspectors of the local Public Health Unit performed an epidemiological investigation. A retrospective cohort study was conducted among the customers. Food and environmental samples were collected. Due to the rapid onset of symptoms (vomiting, diarrhea), the food samples were analyzed for the presence of toxigenic bacteria and their toxins; nasopharyngeal swabs were collected from the waiters and cooks. Among the food tested, high levels of coagulase-positive staphylococci (CPS) (3.4 × 108 CFU/g) and staphylococcal enterotoxins (2.12 ng SEA/g) were only detected in the Chantilly cream dessert. CPS were also detected on the surface of a kitchen table (10 CFU/swab), and five food handlers were positive for Staphylococcus aureus. In total, five enterotoxigenic S. aureus isolates were recovered from three food handlers, a kitchen surface, and the Chantilly cream dessert. These isolates were further characterized by biotyping, pulsed-field gel electrophoresis, and multiplex polymerase chain reaction assays for the detection of eleven enterotoxin encoding genes (sea, seb, sec, sed, see, seg, seh, sei, sej, sep, and ser) and three genes involved in antibiotic resistance (mecA, mecC, and mupA). Three sea-positive strains, isolated from the dessert, environment, and one of the cooks, had the same pulsed-field gel electrophoresis profile and belonged to the human biotype, suggesting that the contamination causing the outbreak most likely originated from a food handler. Moreover, improper storage of the dessert, at room temperature for about 5 h, permitted microbial growth and SEA production. This study underlines the importance of both laboratory evidence and epidemiological data for outbreak investigation. PMID:28402712

Lymphocyte Redox Imbalance and Reduced Proliferation after a Single Session of High Intensity Interval Exercise

PubMed Central

Tossige-Gomes, Rosalina; Costa, Karine Beatriz; Ottone, Vinícius de Oliveira; Magalhães, Flávio de Castro; Amorim, Fabiano Trigueiro; Rocha-Vieira, Etel

2016-01-01

This study investigated whether an acute session of high-intensity interval training (HIIT) is sufficient to alter lymphocyte function and redox status. Sixteen young healthy men underwent a HIIT session on a cycloergometer, consisting of eight bouts of 1 min at 90–100% of peak power, with 75 seconds of active recovery at 30 W between bouts. Venous blood was collected before, immediately after, and 30 minutes after the HIIT session. In response to Staphylococcus aureus superantigen B (SEB) stimulation, lymphocyte proliferation decreased and the IL-2 concentration increased after the HIIT session. However, the HIIT session had no effect on lymphocyte proliferation or IL-2 response to phytohemagglutinin stimulation. The HIIT session also induced lymphocyte redox imbalance, characterized by an increase in the concentration of thiobarbituric acid reactive substances and a decrease in the activity of the antioxidant enzyme catalase. Lymphocyte viability was not affected by the HIIT session. The frequencies of CD25+ and CD69+ T helper and B lymphocytes in response to superantigen stimulation were lower after exercise, suggesting that superantigen-induced lymphocyte activation was reduced by HIIT. However, HIIT also led to a reduction in the frequency of CD4+ and CD19+ cells, so the frequencies of CD25+ and CD69+ cells within the CD4 and CD19 cell populations were not affected by HIIT. These data indicate that the reduced lymphocyte proliferation observed after HIIT is not due to reduced early lymphocyte activation by superantigen. Our findings show that an acute HIIT session promotes lymphocyte redox imbalance and reduces lymphocyte proliferation in response to superantigenic, but not to mitogenic stimulation. This observation cannot be explained by alteration of the early lymphocyte activation response to superantigen. The manner in which lymphocyte function modulation by an acute HIIT session can affect individual immunity and susceptibility to infection is important and requires further investigation. PMID:27096389

Biofilm formation and virulence factor analysis of Staphylococcus aureus isolates collected from ovine mastitis.

PubMed

Azara, E; Longheu, C; Sanna, G; Tola, S

2017-08-01

To perform a phenotypic and genotypic characterization of 258 Staphylococcus aureus isolates from clinical ovine mastitis and used for the preparation of inactivated autogenous vaccines. The potential for biofilm production was determined by phenotypic test of Congo Red Agar (CRA) and by PCR for the detection of icaA/D genes. Isolates were also screened by PCR for the presence of enterotoxins (sea, seb, sec, sed and see), toxic shock syndrome toxin (tsst), leukotoxins (lukD-E, lukM and lukPV83), haemolysins (hly-β and hly-γ), autolysin (atlA) genes and encoding microbial surface components recognizing adhesive matrix molecules (MSCRAMMs: clfA, clfB, fnbA, fnbB, bbp, cna, eno, fib, epbs, sdrC, sdrD and SdrE). None of the 258 isolates showed biofilm-forming ability on CRA and harboured icaA/D genes. The most frequent pyrogenic toxin superantigen genes amplified were sec plus tsst-1, which were found strictly in combination with 71·3% of the Staph. aureus isolates tested. None of the isolates harboured the genes encoding sea and see. Of the 258 isolates tested, 159 (61·6%) possessed all lukD-E/lukM/lukPV83 genes, 123 (47·7%) harboured both hly-β/hly-γ genes, whereas almost all (97·3%) were PCR positive for atlA gene. With respect to adhesion determinants, 179 (69·4%) isolates presented simultaneously four genes (fnbA, fib, clfA and clfB) for fibronectin- and fibrinogen-binding proteins. In this search, several putative virulence determinants have been identified in ovine Staph. aureus isolates collected in Sardinia. Some of the putative virulence determinants could be considered as components of a vaccine because of their role in ovine mastitis pathogenesis. © 2017 The Society for Applied Microbiology.

Seasonal and Non-Seasonal Variations of Jupiter's Atmosphere from Observations of Thermal Emission, 1994-2011

NASA Technical Reports Server (NTRS)

Orton, G.; Fletcher, L.; Yanamandra-Fisher, P.; Greathouse, T.; Fisher, B.; Greco, J.; Wakefield, L.; Snead, E.; Boydstun, K.; Simon-Miller, A.;

Soft error rate simulation and initial design considerations of neutron intercepting silicon chip (NISC)

NASA Astrophysics Data System (ADS)

Celik, Cihangir

Advances in microelectronics result in sub-micrometer electronic technologies as predicted by Moore's Law, 1965, which states the number of transistors in a given space would double every two years. The most available memory architectures today have submicrometer transistor dimensions. The International Technology Roadmap for Semiconductors (ITRS), a continuation of Moore's Law, predicts that Dynamic Random Access Memory (DRAM) will have an average half pitch size of 50 nm and Microprocessor Units (MPU) will have an average gate length of 30 nm over the period of 2008-2012. Decreases in the dimensions satisfy the producer and consumer requirements of low power consumption, more data storage for a given space, faster clock speed, and portability of integrated circuits (IC), particularly memories. On the other hand, these properties also lead to a higher susceptibility of IC designs to temperature, magnetic interference, power supply, and environmental noise, and radiation. Radiation can directly or indirectly affect device operation. When a single energetic particle strikes a sensitive node in the micro-electronic device, it can cause a permanent or transient malfunction in the device. This behavior is called a Single Event Effect (SEE). SEEs are mostly transient errors that generate an electric pulse which alters the state of a logic node in the memory device without having a permanent effect on the functionality of the device. This is called a Single Event Upset (SEU) or Soft Error . Contrary to SEU, Single Event Latchup (SEL), Single Event Gate Rapture (SEGR), or Single Event Burnout (SEB) they have permanent effects on the device operation and a system reset or recovery is needed to return to proper operations. The rate at which a device or system encounters soft errors is defined as Soft Error Rate (SER). The semiconductor industry has been struggling with SEEs and is taking necessary measures in order to continue to improve system designs in nano-scale technologies. Prevention of SEEs has been studied and applied in the semiconductor industry by including radiation protection precautions in the system architecture or by using corrective algorithms in the system operation. Decreasing 10B content (20%of natural boron) in the natural boron of Borophosphosilicate glass (BPSG) layers that are conventionally used in the fabrication of semiconductor devices was one of the major radiation protection approaches for the system architecture. Neutron interaction in the BPSG layer was the origin of the SEEs because of the 10B (n,alpha) 7Li reaction products. Both of the particles produced have the capability of ionization in the silicon substrate region, whose thickness is comparable to the ranges of these particles. Using the soft error phenomenon in exactly the opposite manner of the semiconductor industry can provide a new neutron detection system based on the SERs in the semiconductor memories. By investigating the soft error mechanisms in the available semiconductor memories and enhancing the soft error occurrences in these devices, one can convert all memory using intelligent systems into portable, power efficient, directiondependent neutron detectors. The Neutron Intercepting Silicon Chip (NISC) project aims to achieve this goal by introducing 10B-enriched BPSG layers to the semiconductor memory architectures. This research addresses the development of a simulation tool, the NISC Soft Error Analysis Tool (NISCSAT), for soft error modeling and analysis in the semiconductor memories to provide basic design considerations for the NISC. NISCSAT performs particle transport and calculates the soft error probabilities, or SER, depending on energy depositions of the particles in a given memory node model of the NISC. Soft error measurements were performed with commercially available, off-the-shelf semiconductor memories and microprocessors to observe soft error variations with the neutron flux and memory supply voltage. Measurement results show that soft errors in the memories increase proportionally with the neutron flux, whereas they decrease with increasing the supply voltages. NISC design considerations include the effects of device scaling, 10B content in the BPSG layer, incoming neutron energy, and critical charge of the node for this dissertation. NISCSAT simulations were performed with various memory node models to account these effects. Device scaling simulations showed that any further increase in the thickness of the BPSG layer beyond 2 mum causes self-shielding of the incoming neutrons due to the BPSG layer and results in lower detection efficiencies. Moreover, if the BPSG layer is located more than 4 mum apart from the depletion region in the node, there are no soft errors in the node due to the fact that both of the reaction products have lower ranges in the silicon or any possible node layers. Calculation results regarding the critical charge indicated that the mean charge deposition of the reaction products in the sensitive volume of the node is about 15 fC. It is evident that the NISC design should have a memory architecture with a critical charge of 15 fC or less to obtain higher detection efficiencies. Moreover, the sensitive volume should be placed in close proximity to the BPSG layers so that its location would be within the range of alpha and 7Li particles. Results showed that the distance between the BPSG layer and the sensitive volume should be less than 2 mum to increase the detection efficiency of the NISC. Incoming neutron energy was also investigated by simulations and the results obtained from these simulations showed that NISC neutron detection efficiency is related with the neutron cross-sections of 10B (n,alpha) 7Li reaction, e.g., ratio of the thermal (0.0253 eV) to fast (2 MeV) neutron detection efficiencies is approximately equal to 8000:1. Environmental conditions and their effects on the NISC performance were also studied in this research. Cosmic rays were modeled and simulated via NISCSAT to investigate detection reliability of the NISC. Simulation results show that cosmic rays account for less than 2 % of the soft errors for the thermal neutron detection. On the other hand, fast neutron detection by the NISC, which already has a poor efficiency due to the low neutron cross-sections, becomes almost impossible at higher altitudes where the cosmic ray fluxes and their energies are higher. NISCSAT simulations regarding soft error dependency of the NISC for temperature and electromagnetic fields show that there are no significant effects in the NISC detection efficiency. Furthermore, the detection efficiency of the NISC decreases with both air humidity and use of moderators since the incoming neutrons scatter away before reaching the memory surface.

Ionic-liquid mediated olefin hydroboration and heteroatom insertion reactions, and the development of template routes to non-oxide ceramic nano- and micro-structures

NASA Astrophysics Data System (ADS)

Kusari, Upal

The goal of the work described in this dissertation was two-fold: (1) To use the unique properties of ionic liquids to develop new synthetic routes to boron-containing molecules including substituted decaboranes, ortho-carboranes and chalcogeno-boranes, and (2) to combine newly developed chemical precursors with template routes to fabricate the non-oxide ceramics boron carbide, silicon carbide and boron nitride on the micro- and nano-scales. The first application of ionic liquid and related salt systems to the hydroboration of a variety of olefins with the polyborane cage B10H 14, leading to the syntheses of functionalized decaborane clusters, 6-R-B10H13, was demonstrated. The decaborane olefin-hydroboration reaction was found to proceed with a wide variety of functional olefins, including, alkenyl, halide, phenyl, ether, ester, pinacolborane, ketone and alcohol-containing olefins. These reactions provide a general, simple, one-pot and high-yield alternative route to functional boranes. The functional decaboranes were then converted by another ionic liquid mediated reaction, to its ortho -carborane derivatives 3-R-1,2-Et2C2B 10H9. Experimental and computational studies of the hydroboration mechanism suggest that the ionic liquid induced the formation of the B 10H13- anion which behaved as an electrophile in the olefin-hydroboration reaction. The unique properties of ionic liquids were also found to be useful in mediating the insertion of chalcogen heteroatoms into the borane clusters nido-B10H14, nido-5,6-C2B8H12 and arachno -4-CB8H14 and led to the improved syntheses of the known compounds nido-7-SB10H12, nido-7-SeB10H12, nido-7,9,10-SC 2B8H10, nido-7,9,10-SeC 2B8H10 and arachno-6,9-CSB 8H12, as well as the synthesis of the new 10-vertex selena-monocarbaborane arachno-6,9-CSeB8H12 (˜40% yield). The second part of the thesis demonstrated that newly developed chemical precursors can be used in conjunction with silica bead and diatom frustule templates to generate highly uniform, nanoporous layered materials and 3-D, free-standing nano- and micro-structures of boron carbide, boron nitride and silicon carbide. The retention of structural features on the micron and nanometer length scales, allowed the fabrication of advanced materials with a range of potential applications, as shown by the production of a SiC/BN-microbasket composite using the frustule template-derived boron nitride replicas.

Continuous system modeling

NASA Technical Reports Server (NTRS)

Cellier, Francois E.

1991-01-01

A comprehensive and systematic introduction is presented for the concepts associated with 'modeling', involving the transition from a physical system down to an abstract description of that system in the form of a set of differential and/or difference equations, and basing its treatment of modeling on the mathematics of dynamical systems. Attention is given to the principles of passive electrical circuit modeling, planar mechanical systems modeling, hierarchical modular modeling of continuous systems, and bond-graph modeling. Also discussed are modeling in equilibrium thermodynamics, population dynamics, and system dynamics, inductive reasoning, artificial neural networks, and automated model synthesis.

Feature-based component model for design of embedded systems

NASA Astrophysics Data System (ADS)

Zha, Xuan Fang; Sriram, Ram D.

2004-11-01

An embedded system is a hybrid of hardware and software, which combines software's flexibility and hardware real-time performance. Embedded systems can be considered as assemblies of hardware and software components. An Open Embedded System Model (OESM) is currently being developed at NIST to provide a standard representation and exchange protocol for embedded systems and system-level design, simulation, and testing information. This paper proposes an approach to representing an embedded system feature-based model in OESM, i.e., Open Embedded System Feature Model (OESFM), addressing models of embedded system artifacts, embedded system components, embedded system features, and embedded system configuration/assembly. The approach provides an object-oriented UML (Unified Modeling Language) representation for the embedded system feature model and defines an extension to the NIST Core Product Model. The model provides a feature-based component framework allowing the designer to develop a virtual embedded system prototype through assembling virtual components. The framework not only provides a formal precise model of the embedded system prototype but also offers the possibility of designing variation of prototypes whose members are derived by changing certain virtual components with different features. A case study example is discussed to illustrate the embedded system model.

The Value of SysML Modeling During System Operations: A Case Study

NASA Technical Reports Server (NTRS)

Dutenhoffer, Chelsea; Tirona, Joseph

2013-01-01

System models are often touted as engineering tools that promote better understanding of systems, but these models are typically created during system design. The Ground Data System (GDS) team for the Dawn spacecraft took on a case study to see if benefits could be achieved by starting a model of a system already in operations. This paper focuses on the four steps the team undertook in modeling the Dawn GDS: defining a model structure, populating model elements, verifying that the model represented reality, and using the model to answer system-level questions and simplify day-to-day tasks. Throughout this paper the team outlines our thought processes and the system insights the model provided.

The value of SysML modeling during system operations: A case study

NASA Astrophysics Data System (ADS)

Dutenhoffer, C.; Tirona, J.

System models are often touted as engineering tools that promote better understanding of systems, but these models are typically created during system design. The Ground Data System (GDS) team for the Dawn spacecraft took on a case study to see if benefits could be achieved by starting a model of a system already in operations. This paper focuses on the four steps the team undertook in modeling the Dawn GDS: defining a model structure, populating model elements, verifying that the model represented reality, and using the model to answer system-level questions and simplify day-to-day tasks. Throughout this paper the team outlines our thought processes and the system insights the model provided.

A Model-Driven Visualization Tool for Use with Model-Based Systems Engineering Projects

NASA Technical Reports Server (NTRS)

Trase, Kathryn; Fink, Eric

2014-01-01

Model-Based Systems Engineering (MBSE) promotes increased consistency between a system's design and its design documentation through the use of an object-oriented system model. The creation of this system model facilitates data presentation by providing a mechanism from which information can be extracted by automated manipulation of model content. Existing MBSE tools enable model creation, but are often too complex for the unfamiliar model viewer to easily use. These tools do not yet provide many opportunities for easing into the development and use of a system model when system design documentation already exists. This study creates a Systems Modeling Language (SysML) Document Traceability Framework (SDTF) for integrating design documentation with a system model, and develops an Interactive Visualization Engine for SysML Tools (InVEST), that exports consistent, clear, and concise views of SysML model data. These exported views are each meaningful to a variety of project stakeholders with differing subjects of concern and depth of technical involvement. InVEST allows a model user to generate multiple views and reports from a MBSE model, including wiki pages and interactive visualizations of data. System data can also be filtered to present only the information relevant to the particular stakeholder, resulting in a view that is both consistent with the larger system model and other model views. Viewing the relationships between system artifacts and documentation, and filtering through data to see specialized views improves the value of the system as a whole, as data becomes information

Communication system modeling

NASA Technical Reports Server (NTRS)

Holland, L. D.; Walsh, J. R., Jr.; Wetherington, R. D.

1971-01-01

This report presents the results of work on communications systems modeling and covers three different areas of modeling. The first of these deals with the modeling of signals in communication systems in the frequency domain and the calculation of spectra for various modulations. These techniques are applied in determining the frequency spectra produced by a unified carrier system, the down-link portion of the Command and Communications System (CCS). The second modeling area covers the modeling of portions of a communication system on a block basis. A detailed analysis and modeling effort based on control theory is presented along with its application to modeling of the automatic frequency control system of an FM transmitter. A third topic discussed is a method for approximate modeling of stiff systems using state variable techniques.

Adaptive System Modeling for Spacecraft Simulation

NASA Technical Reports Server (NTRS)

Thomas, Justin

2011-01-01

This invention introduces a methodology and associated software tools for automatically learning spacecraft system models without any assumptions regarding system behavior. Data stream mining techniques were used to learn models for critical portions of the International Space Station (ISS) Electrical Power System (EPS). Evaluation on historical ISS telemetry data shows that adaptive system modeling reduces simulation error anywhere from 50 to 90 percent over existing approaches. The purpose of the methodology is to outline how someone can create accurate system models from sensor (telemetry) data. The purpose of the software is to support the methodology. The software provides analysis tools to design the adaptive models. The software also provides the algorithms to initially build system models and continuously update them from the latest streaming sensor data. The main strengths are as follows: Creates accurate spacecraft system models without in-depth system knowledge or any assumptions about system behavior. Automatically updates/calibrates system models using the latest streaming sensor data. Creates device specific models that capture the exact behavior of devices of the same type. Adapts to evolving systems. Can reduce computational complexity (faster simulations).

Moving alcohol prevention research forward-Part II: new directions grounded in community-based system dynamics modeling.

PubMed

Apostolopoulos, Yorghos; Lemke, Michael K; Barry, Adam E; Lich, Kristen Hassmiller

2018-02-01

Given the complexity of factors contributing to alcohol misuse, appropriate epistemologies and methodologies are needed to understand and intervene meaningfully. We aimed to (1) provide an overview of computational modeling methodologies, with an emphasis on system dynamics modeling; (2) explain how community-based system dynamics modeling can forge new directions in alcohol prevention research; and (3) present a primer on how to build alcohol misuse simulation models using system dynamics modeling, with an emphasis on stakeholder involvement, data sources and model validation. Throughout, we use alcohol misuse among college students in the United States as a heuristic example for demonstrating these methodologies. System dynamics modeling employs a top-down aggregate approach to understanding dynamically complex problems. Its three foundational properties-stocks, flows and feedbacks-capture non-linearity, time-delayed effects and other system characteristics. As a methodological choice, system dynamics modeling is amenable to participatory approaches; in particular, community-based system dynamics modeling has been used to build impactful models for addressing dynamically complex problems. The process of community-based system dynamics modeling consists of numerous stages: (1) creating model boundary charts, behavior-over-time-graphs and preliminary system dynamics models using group model-building techniques; (2) model formulation; (3) model calibration; (4) model testing and validation; and (5) model simulation using learning-laboratory techniques. Community-based system dynamics modeling can provide powerful tools for policy and intervention decisions that can result ultimately in sustainable changes in research and action in alcohol misuse prevention. © 2017 Society for the Study of Addiction.

A novel simulation theory and model system for multi-field coupling pipe-flow system

NASA Astrophysics Data System (ADS)

Chen, Yang; Jiang, Fan; Cai, Guobiao; Xu, Xu

2017-09-01

Due to the lack of a theoretical basis for multi-field coupling in many system-level models, a novel set of system-level basic equations for flow/heat transfer/combustion coupling is put forward. Then a finite volume model of quasi-1D transient flow field for multi-species compressible variable-cross-section pipe flow is established by discretising the basic equations on spatially staggered grids. Combining with the 2D axisymmetric model for pipe-wall temperature field and specific chemical reaction mechanisms, a finite volume model system is established; a set of specific calculation methods suitable for multi-field coupling system-level research is structured for various parameters in this model; specific modularisation simulation models can be further derived in accordance with specific structures of various typical components in a liquid propulsion system. This novel system can also be used to derive two sub-systems: a flow/heat transfer two-field coupling pipe-flow model system without chemical reaction and species diffusion; and a chemical equilibrium thermodynamic calculation-based multi-field coupling system. The applicability and accuracy of two sub-systems have been verified through a series of dynamic modelling and simulations in earlier studies. The validity of this system is verified in an air-hydrogen combustion sample system. The basic equations and the model system provide a unified universal theory and numerical system for modelling and simulation and even virtual testing of various pipeline systems.

Rule-based simulation models

NASA Technical Reports Server (NTRS)

Nieten, Joseph L.; Seraphine, Kathleen M.

1991-01-01

Procedural modeling systems, rule based modeling systems, and a method for converting a procedural model to a rule based model are described. Simulation models are used to represent real time engineering systems. A real time system can be represented by a set of equations or functions connected so that they perform in the same manner as the actual system. Most modeling system languages are based on FORTRAN or some other procedural language. Therefore, they must be enhanced with a reaction capability. Rule based systems are reactive by definition. Once the engineering system has been decomposed into a set of calculations using only basic algebraic unary operations, a knowledge network of calculations and functions can be constructed. The knowledge network required by a rule based system can be generated by a knowledge acquisition tool or a source level compiler. The compiler would take an existing model source file, a syntax template, and a symbol table and generate the knowledge network. Thus, existing procedural models can be translated and executed by a rule based system. Neural models can be provide the high capacity data manipulation required by the most complex real time models.

What can formal methods offer to digital flight control systems design

NASA Technical Reports Server (NTRS)

Good, Donald I.

1990-01-01

Formal methods research begins to produce methods which will enable mathematic modeling of the physical behavior of digital hardware and software systems. The development of these methods directly supports the NASA mission of increasing the scope and effectiveness of flight system modeling capabilities. The conventional, continuous mathematics that is used extensively in modeling flight systems is not adequate for accurate modeling of digital systems. Therefore, the current practice of digital flight control system design has not had the benefits of extensive mathematical modeling which are common in other parts of flight system engineering. Formal methods research shows that by using discrete mathematics, very accurate modeling of digital systems is possible. These discrete modeling methods will bring the traditional benefits of modeling to digital hardware and hardware design. Sound reasoning about accurate mathematical models of flight control systems can be an important part of reducing risk of unsafe flight control.

Component model reduction via the projection and assembly method

NASA Technical Reports Server (NTRS)

Bernard, Douglas E.

1989-01-01

The problem of acquiring a simple but sufficiently accurate model of a dynamic system is made more difficult when the dynamic system of interest is a multibody system comprised of several components. A low order system model may be created by reducing the order of the component models and making use of various available multibody dynamics programs to assemble them into a system model. The difficulty is in choosing the reduced order component models to meet system level requirements. The projection and assembly method, proposed originally by Eke, solves this difficulty by forming the full order system model, performing model reduction at the the system level using system level requirements, and then projecting the desired modes onto the components for component level model reduction. The projection and assembly method is analyzed to show the conditions under which the desired modes are captured exactly; to the numerical precision of the algorithm.

The System of Systems Architecture Feasibility Assessment Model

DTIC Science & Technology

2016-06-01

OF SYSTEMS ARCHITECTURE FEASIBILITY ASSESSMENT MODEL by Stephen E. Gillespie June 2016 Dissertation Supervisor Eugene Paulo THIS PAGE...Dissertation 4. TITLE AND SUBTITLE THE SYSTEM OF SYSTEMS ARCHITECTURE FEASIBILITY ASSESSMENT MODEL 5. FUNDING NUMBERS 6. AUTHOR(S) Stephen E...SoS architecture feasibility assessment model (SoS-AFAM). Together, these extend current model- based systems engineering (MBSE) and SoS engineering

Using the Model Coupling Toolkit to couple earth system models

USGS Publications Warehouse

Warner, J.C.; Perlin, N.; Skyllingstad, E.D.

2008-01-01

Continued advances in computational resources are providing the opportunity to operate more sophisticated numerical models. Additionally, there is an increasing demand for multidisciplinary studies that include interactions between different physical processes. Therefore there is a strong desire to develop coupled modeling systems that utilize existing models and allow efficient data exchange and model control. The basic system would entail model "1" running on "M" processors and model "2" running on "N" processors, with efficient exchange of model fields at predetermined synchronization intervals. Here we demonstrate two coupled systems: the coupling of the ocean circulation model Regional Ocean Modeling System (ROMS) to the surface wave model Simulating WAves Nearshore (SWAN), and the coupling of ROMS to the atmospheric model Coupled Ocean Atmosphere Prediction System (COAMPS). Both coupled systems use the Model Coupling Toolkit (MCT) as a mechanism for operation control and inter-model distributed memory transfer of model variables. In this paper we describe requirements and other options for model coupling, explain the MCT library, ROMS, SWAN and COAMPS models, methods for grid decomposition and sparse matrix interpolation, and provide an example from each coupled system. Methods presented in this paper are clearly applicable for coupling of other types of models. ?? 2008 Elsevier Ltd. All rights reserved.

Virtual Observation System for Earth System Model: An Application to ACME Land Model Simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Dali; Yuan, Fengming; Hernandez, Benjamin

Investigating and evaluating physical-chemical-biological processes within an Earth system model (EMS) can be very challenging due to the complexity of both model design and software implementation. A virtual observation system (VOS) is presented to enable interactive observation of these processes during system simulation. Based on advance computing technologies, such as compiler-based software analysis, automatic code instrumentation, and high-performance data transport, the VOS provides run-time observation capability, in-situ data analytics for Earth system model simulation, model behavior adjustment opportunities through simulation steering. A VOS for a terrestrial land model simulation within the Accelerated Climate Modeling for Energy model is also presentedmore » to demonstrate the implementation details and system innovations.« less