Science.gov

Sample records for accumulation product lap

  1. Lipid accumulation product (LAP) as a criterion for the identification of the healthy obesity phenotype in postmenopausal women.

    PubMed

    Lwow, Felicja; Jedrzejuk, Diana; Milewicz, Andrzej; Szmigiero, Leszek

    2016-09-01

    Obesity and its complications constitute a major health problem in postmenopausal women. The identification of the obesity phenotype, especially that of metabolically healthy obese (MHO) patients, is a necessary part of obesity treatment protocols. There are several methods to define MHO, but unfortunately, all of them are arbitrary and inconsistent. The aim of this work was to determine whether lipid accumulation product (LAP) could be used as a marker of the MHO phenotype in postmenopausal women. A sample of 345 Polish postmenopausal women aged 50-60years old participated in the study. Participants were classified as obese when their BMI was >27. Receiver operating characteristic curve analysis was performed to estimate the best cutoff for the LAP index value to identify postmenopausal women without metabolic syndrome components. We found that the best cutoff value was LAP ≤29.9, and this value was used to define MHO individuals. With this definition, the identification of MHO individuals could be made when both of the following criteria were met: LAP index ≤29.9 and no arterial hypertension (SBP<130mmHg, DBP<85mmHg). The anthropometric and body fat distribution measurements, as well as the metabolic characteristics of MHO women identified according to the above definition, were compared with those of MHO women identified by two other methods in the literature. These methods and our definition identified similar proportions of MHO women ranging from 11.6% to 16.9%. We found that MHO women identified by all of the definitions used in this study possessed a similar metabolic status, and they did not differ in anthropometric indices or body fat distribution measurements. We concluded that the combination of LAP estimation and arterial blood pressure measurement appear to constitute a useful method for identifying the MHO phenotype in postmenopausal women. PMID:27329927

  2. Associação entre lipid accumulation product (LAP) e hirsutismo na síndrome do ovário policístico.

    PubMed

    Oliveira, Flávia Ribeiro de; Rezende, Mariana Bicalho; Faria, Nícolas Figueiredo; Dias, Tomás Ribeiro Gonçalves; Oliveira, Walter Carlos Santos de; Rocha, Ana Luiza Lunardi; Cândido, Ana Lúcia

    2016-02-01

    Objective Polycystic ovary syndrome (PCOS) is the most common endocrine metabolic disorder in women between menarche and menopause. Clinical hyperandrogenism is the most important diagnostic criterion of the syndrome, which manifests as hirsutism in 70% of cases. Hirsute carriers of PCOS have high cardiovascular risk. Lipid accumulation product (LAP) is an index for the evaluation of lipid accumulation in adults and the prediction of cardiovascular risk. The aim of this study was to evaluate the association between LAP and hirsutism in women with PCOS. Methods This was a cross-sectional observational study of a secondary database, which included 263 patients who had visited the Hyperandrogenism Outpatient Clinic from November 2009 to July 2014. The exclusion criteria were patients without Ferriman-Gallwey index (FGI) and/or LAP data. We used the Rotterdam criteria for the diagnosis of PCOS. All patients underwent medical assessment followed by measurement and recording of anthropometric data and the laboratory tests for measurement of the following: thyroid-stimulating hormone, follicle-stimulating hormone, prolactin, total testosterone, sex hormone binding globulin, 17-α-hydroxyprogesterone (follicular phase), glycohemoglobin A1c, and basal insulin. In addition, the subjects underwent lipid profiling and oral glucose tolerance tests. Other laboratory measurements were determined according to clinical criteria. LAP and the homeostatic model assessment index (HOMA-IR) were calculated using the data obtained. We divided patients into two groups: the PCOS group with normal LAP (< 34.5) and the PCOS group with altered LAP (> 34.5) to compare the occurrence of hirsutism. For statistical analysis, we used SPSS Statistics for Windows® and Microsoft Excel programs, with descriptive (frequencies, percentages, means, and standard deviations) and comparative analyses (Student's t-test and Chi-square test). We considered relations significant when the p-value was

  3. LAP degradation product reflects plasma kallikrein-dependent TGF-β activation in patients with hepatic fibrosis.

    PubMed

    Hara, Mitsuko; Kirita, Akiko; Kondo, Wakako; Matsuura, Tomokazu; Nagatsuma, Keisuke; Dohmae, Naoshi; Ogawa, Shinji; Imajoh-Ohmi, Shinobu; Friedman, Scott L; Rifkin, Daniel B; Kojima, Soichi

    2014-01-01

    Byproducts of cytokine activation are sometimes useful as surrogate biomarkers for monitoring cytokine generation in patients. Transforming growth factor (TGF)-β plays a pivotal role in pathogenesis of hepatic fibrosis. TGF-β is produced as part of an inactive latent complex, in which the cytokine is trapped by its propeptide, the latency-associated protein (LAP). Therefore, to exert its biological activity, TGF-β must be released from the latent complex. Several proteases activate latent TGF-β by cutting LAP. We previously reported that Camostat Mesilate, a broad spectrum protease inhibitor, which is especially potent at inhibiting plasma kallikrein (PLK), prevented liver fibrosis in the porcine serum-induced liver fibrosis model in rats. We suggested that PLK may work as an activator of latent TGF-β during the pathogenesis of liver diseases in the animal models. However, it remained to be elucidated whether this activation mechanism also functions in fibrotic liver in patients. Here, we report that PLK cleaves LAP between R(58) and L(59) residues. We have produced monoclonal antibodies against two degradation products of LAP (LAP-DP) by PLK, and we have used these specific antibodies to immunostain LAP-DP in liver tissues from both fibrotic animals and patients. The N-terminal side LAP-DP ending at R(58) (R(58) LAP-DP) was detected in liver tissues, while the C-terminal side LAP-DP beginning at L(59) (L(59) LAP-DP) was not detectable. The R(58) LAP-DP was seen mostly in α-smooth muscle actin-positive activated stellate cells. These data suggest for the first time that the occurrence of a PLK-dependent TGF-β activation reaction in patients and indicates that the LAP-DP may be useful as a surrogate marker reflecting PLK-dependent TGF-β activation in fibrotic liver both in animal models and in patients. PMID:24877031

  4. Lapping slurry

    DOEpatents

    Simandl, R.F.; Upchurch, V.S.; Leitten, M.E.

    1999-01-05

    Improved lapping slurries provide for easier and more thorough cleaning of alumina work pieces, as well as inhibit corrosion of the lapping table and provide for easier cleaning of the lapping equipment. The unthickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, and triethanolamine. The thickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, triethanolamine, a water soluble silicate, and acid. 1 fig.

  5. Lapping slurry

    DOEpatents

    Simandl, Ronald F.; Upchurch, Victor S.; Leitten, Michael E.

    1999-01-01

    Improved lapping slurries provide for easier and more thorough cleaning of alumina workpieces, as well as inhibit corrosion of the lapping table and provide for easier cleaning of the lapping equipment. The unthickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, and triethanolamine. The thickened lapping slurry comprises abrasive grains such as diamond abrasive dispersed in a carrier comprising water, glycerine, triethanolamine, a water soluble silicate, and acid.

  6. LAP5 and LAP6 encode anther-specific proteins with similarity to chalcone synthase essential for pollen exine development in Arabidopsis.

    PubMed

    Dobritsa, Anna A; Lei, Zhentian; Nishikawa, Shuh-Ichi; Urbanczyk-Wochniak, Ewa; Huhman, David V; Preuss, Daphne; Sumner, Lloyd W

    2010-07-01

    Pollen grains of land plants have evolved remarkably strong outer walls referred to as exine that protect pollen and interact with female stigma cells. Exine is composed of sporopollenin, and while the composition and synthesis of this biopolymer are not well understood, both fatty acids and phenolics are likely components. Here, we describe mutations in the Arabidopsis (Arabidopsis thaliana) LESS ADHESIVE POLLEN (LAP5) and LAP6 that affect exine development. Mutation of either gene results in abnormal exine patterning, whereas pollen of double mutants lacked exine deposition and subsequently collapsed, causing male sterility. LAP5 and LAP6 encode anther-specific proteins with homology to chalcone synthase, a key flavonoid biosynthesis enzyme. lap5 and lap6 mutations reduced the accumulation of flavonoid precursors and flavonoids in developing anthers, suggesting a role in the synthesis of phenolic constituents of sporopollenin. Our in vitro functional analysis of LAP5 and LAP6 using 4-coumaroyl-coenzyme A yielded bis-noryangonin (a commonly reported derailment product of chalcone synthase), while similar in vitro analyses using fatty acyl-coenzyme A as the substrate yielded medium-chain alkyl pyrones. Thus, in vitro assays indicate that LAP5 and LAP6 are multifunctional enzymes and may play a role in both the synthesis of pollen fatty acids and phenolics found in exine. Finally, the genetic interaction between LAP5 and an anther gene involved in fatty acid hydroxylation (CYP703A2) demonstrated that they act synergistically in exine production. PMID:20442277

  7. Role of lymphocyte activation products (LAP) in cell-mediated immunity. II. Effects of lymphocyte activation products on lymph node architecture and evidence for peripheral release of LAP following antigenic stimulation

    PubMed Central

    Kelly, R. H.; Wolstencroft, R. A.; Dumonde, D. C.; Balfour, Brigid M.

    1972-01-01

    The experiments reported here were concerned with determining the effects of lymphocyte activation products (LAP) on lymph node architecture, and with assaying afferent lymph for evidence of the peripheral release of LAP during the induction of an immune response. Intralymphatic inoculation of purified homologous LAP into guinea-pigs resulted in increased weight and cellular content of the draining node. Histologically these nodes showed paracortical distension and dense aggregations of lymphoid cells or `cellular plugs' in the paracortical sinuses. It was suggested that one effect of LAP may be to cause cellular retention in the paracortex of lymph nodes by regulating the rate of cell exit via the sinuses of the node. The peripheral lymph of rabbits was assayed for its ability to inhibit macrophage migration and to accelerate lymphocyte DNA synthesis after stimulation with three different antigens. The antigens were chosen to give a spectrum which ranged from a primarily humoral response (erythrocyte stimulation) through a mixed humoral and cell-mediated response (diphtheria toxoid stimulation) to a predominantly cell-mediated type of response (skin contact sensitization to fluorodinitrobenzene–FDNB). Paracortical distension with lymphoid cell sinus plugging, similar to that observed in the guinea-pig nodes following intralymphatic injection of LAP, were common features of both the diphtheria toxoid and FDNB responses. It was concluded that the development of this type of sinus plugging and paracortical distension might be related to multiple activities of LAP generated and released either at the peripheral antigen depot or within the draining node. ImagesFig. 5Fig. 2Fig. 3Fig. 4 PMID:4111695

  8. The "lipid accumulation product" is associated with 2-hour postload glucose outcomes in overweight/obese subjects with nondiabetic fasting glucose.

    PubMed

    Malavazos, Alexis Elias; Cereda, Emanuele; Ermetici, Federica; Caccialanza, Riccardo; Briganti, Silvia; Rondanelli, Mariangela; Morricone, Lelio

    2015-01-01

    "Lipid accumulation product" (LAP) is a continuous variable based on waist circumference and triglyceride concentration previously associated with insulin resistance. We investigated the accuracy of LAP in identifying oral glucose tolerance test (OGTT) abnormalities and compared it to the homeostasis model assessment of insulin resistance (HOMA-IR) in a population of overweight/obese outpatients presenting with nondiabetic fasting glucose. We studied 381 (male: 23%) adult (age: 18-70 years) overweight/obese Caucasians (body mass index: 36.9 ± 5.4 Kg/m(2)) having fasting plasma glucose < 7.0 mmol/L. OGTT was used to diagnose unknown glucose tolerance abnormalities: impaired glucose tolerance (IGT) and type-2 diabetes mellitus (T2-DM). According to OGTT 92, subjects had an IGT and 33 were diagnosed T2-DM. Logistic regression analysis detected a significant association for both LAP and HOMA-IR with single (IGT and T2-DM) and composite (IGT + T2-DM) abnormal glucose tolerance conditions. However, while the association with diabetes was similar between LAP and HOMA-IR, the relationship with IGT and composite outcomes by models including LAP was significantly superior to those including HOMA-IR (P = 0.006 and P = 0.007, resp.). LAP seems to be an accurate index, performing better than HOMA-IR, for identifying 2-hour postload OGTT outcomes in overweight/obese patients with nondiabetic fasting glucose. PMID:25792981

  9. 26 CFR 1.263A-11 - Accumulated production expenditures.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 3 2010-04-01 2010-04-01 false Accumulated production expenditures. 1.263A-11 Section 1.263A-11 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Items Not Deductible § 1.263A-11 Accumulated production expenditures. (a) General rule. Accumulated...

  10. 26 CFR 1.263A-11 - Accumulated production expenditures.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... production period. For purposes of determining accumulated production expenditures on any measurement date... subsequent measurement dates and computation periods, that interest is included in accumulated production... subassemblies must be aggregated at each measurement date in a reasonable manner that is consistent with...

  11. Radionuclides accumulation in milk and its products

    NASA Astrophysics Data System (ADS)

    Marmuleva, N. I.; Barinov, E. Ya.; Petukhov, V. L.

    2003-05-01

    The problem of radioactive pollution is extremely urgent in Russia in connection with presence of territories polluted by radionuclides on places of nuclear tests, in zones around the enterprises on production, processing and storage of radioactive materials, and also in areas of emergency pollution (Barakhtin, 2001). The aim of our investigation was a determination of the levels of the main radioactive elements - Cs-137 and Sr-90 in diary products. 363 samples of milk, dry milk, butter, cheese and yogurt from Novosibirsk region were examined. Cs-137 level was 3.7...9.2 times higher than Sr-90 one in milk, cheese and yogurt. At the same time the level of these radio nuclides in butter was identical (8.03 Bk/kg).

  12. Cashier/Checker Learning Activity Packets (LAPs).

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    Twenty-four learning activity packets (LAPs) are provided for six areas of instruction in a cashier/checker program. Section A, Orientation, contains an LAP on exploring the job of cashier-checker. Section B, Operations, has nine LAPs, including those on operating the cash register, issuing trading stamps, and completing the cash register balance…

  13. Factors Influencing Biogenic Amines Accumulation in Dairy Products

    PubMed Central

    Linares, Daniel M.; del Río, Beatriz; Ladero, Victor; Martínez, Noelia; Fernández, María; Martín, María Cruz; Álvarez, Miguel A.

    2012-01-01

    Fermented foods are among the food products more often complained of having caused episodes of biogenic amines (BA) poisoning. Concerning milk-based fermented foods, cheese is the main product likely to contain potentially harmful levels of BA, specially tyramine, histamine, and putrescine. Prompted by the increasing awareness of the risks related to dietary uptake of high biogenic amine loads, in this review we report all those elaboration and processing technological aspects affecting BA biosynthesis and accumulation in dairy foods. Improved knowledge of the factors involved in the synthesis and accumulation of BA should lead to a reduction in their incidence in milk products. Synthesis of BA is possible only when three conditions converge: (i) availability of the substrate amino acids; (ii) presence of microorganisms with the appropriate catabolic pathway activated; and (iii) environmental conditions favorable to the decarboxylation activity. These conditions depend on several factors such as milk treatment (pasteurization), use of starter cultures, NaCl concentration, time, and temperature of ripening and preservation, pH, temperature, or post-ripening technological processes, which will be discussed in this chapter. PMID:22783233

  14. Cranberry Product Decreases Fat Accumulation in Caenorhabditis elegans.

    PubMed

    Sun, Quancai; Yue, Yiren; Shen, Peiyi; Yang, Jeremy J; Park, Yeonhwa

    2016-04-01

    Cranberry phenolic compounds have been linked to many health benefits. A recent report suggested that cranberry bioactives inhibit adipogenesis in 3T3-L1 adipocytes. Thus, we investigated the effects and mechanisms of the cranberry product (CP) on lipid metabolism using the Caenorhabditis elegans (C. elegans) model. CP (0.016% and 0.08%) dose-dependently reduced overall fat accumulation in C. elegans (N2, wild type) by 43% and 74%, respectively, without affecting its pumping rates or locomotive activities. CP decreased fat accumulation in aak-2 (an ortholog of AMP-activated kinase α) and tub-1 (an ortholog of TUBBY) mutants significantly, but only minimal effects were observed in sbp-1 (an ortholog of sterol response element-binding protein-1) and nhr-49 (an ortholog of peroxisome proliferator-activated receptor-α) mutant strains. We further confirmed that CP downregulated sbp-1, cebp, and hosl-1 (an ortholog of hormone-sensitive lipase homolog) expression, while increasing the expression of nhr-49 in wild-type C. elegans. These results suggest that CP could effectively reduce fat accumulation in C. elegans dependent on sbp-1, cebp, and nhr-49, but not aak-2 and tub-1. PMID:26991055

  15. Additive manufacturing of tools for lapping glass

    NASA Astrophysics Data System (ADS)

    Williams, Wesley B.

    2013-09-01

    Additive manufacturing technologies have the ability to directly produce parts with complex geometries without the need for secondary processes, tooling or fixtures. This ability was used to produce concave lapping tools with a VFlash 3D printer from 3D Systems. The lapping tools were first designed in Creo Parametric with a defined constant radius and radial groove pattern. The models were converted to stereolithography files which the VFlash used in building the parts, layer by layer, from a UV curable resin. The tools were rotated at 60 rpm and used with 120 grit and 220 grit silicon carbide lapping paste to lap 0.750" diameter fused silica workpieces. The samples developed a matte appearance on the lapped surface that started as a ring at the edge of the workpiece and expanded to the center. This indicated that as material was removed, the workpiece radius was beginning to match the tool radius. The workpieces were then cleaned and lapped on a second tool (with equivalent geometry) using a 3000 grit corundum aluminum oxide lapping paste, until a near specular surface was achieved. By using lapping tools that have been additively manufactured, fused silica workpieces can be lapped to approach a specified convex geometry. This approach may enable more rapid lapping of near net shape workpieces that minimize the material removal required by subsequent polishing. This research may also enable development of new lapping tool geometry and groove patterns for improved loose abrasive finishing.

  16. How Tongue Size and Roughness Affect Lapping

    NASA Astrophysics Data System (ADS)

    Hubbard, M. J.; Hay, K. M.

    2012-10-01

    The biomechanics of domestic cat lapping (Felis catus) and domestic dog lapping (Canis familiaris) is currently under debate. Lapping mechanics in vertebrates with incomplete cheeks, such as cats and dogs, is a balance of inertia and the force of gravity likely optimized for ingestion and physical necessities. Physiology dictates vertebrate mass, which dictates vertebrate tongue size, which dictates lapping mechanics to achieve optimum liquid ingestion; with either touch lapping, scooping, or a hybrid lapping method. The physics of this optimized system then determines how high a column of liquid can be raised before it collapses due to gravity, and therefore, lapping frequency. Through tongue roughness model variation experiments it was found that pore-scale geometrical roughness does not appear to affect lapping or liquid uptake. Through tongue size model variation experiments it was found that there is a critical tongue radius in the range of 25 mm to 35 mm above which touch lapping is no longer an efficient way to uptake liquid. Vertebrates with incomplete cheeks may use a touch lapping method to ingest water if their tongue radius is less than this critical radius and use an alternative ingestion method if their tongue radius is larger.

  17. Loose abrasive slurries for optical glass lapping

    SciTech Connect

    Neauport, Jerome; Destribats, Julie; Maunier, Cedric; Ambard, Chrystel; Cormont, Philippe; Pintault, B.; Rondeau, Olivier

    2010-10-20

    Loose abrasive lapping is widely used to prepare optical glass before its final polishing. We carried out a comparison of 20 different slurries from four different vendors. Slurry particle sizes and morphologies were measured. Fused silica samples were lapped with these different slurries on a single side polishing machine and characterized in terms of surface roughness and depth of subsurface damage (SSD). Effects of load, rotation speed, and slurry concentration during lapping on roughness, material removal rate, and SSD were investigated.

  18. ACCUMULATION OF PERCHLORATE IN TOBACCO PLANTS AND TOBACCO PRODUCTS

    EPA Science Inventory

    Previous field and laboratory studies with vascular plants have shown that perchlorate is transported from perchlorate fortified soils and is accumulated in the plant tissues and organs. This paper reports results of initial investigations on the accumulation of perchlorate in t...

  19. The effect of diamond powder characteristics on lapping of sintered silicon carbide

    NASA Astrophysics Data System (ADS)

    Rosczyk, Benjamin; Burkam, Eric; Titov, Artem; Onyenemezu, Clement; Benea, Ion C.

    2015-10-01

    In Automotive applications, sintered Silicon Carbide has been used in applications such as seal pump faces. The surface of sintered SiC, when lapped or polished for sealing to another surface, must be free of blemishes and mechanical defects. Lapping and polishing processes therefore must be well defined and controlled assuring minimal variation and production scrap. In this study, we related the characteristics of different diamond powders (particle size distribution, particle shape and surface) to their performance in lapping of sintered silicon carbide material, expressed as removal rate and surface finish.

  20. Quadruple Lap Shear Processing Evaluation

    NASA Technical Reports Server (NTRS)

    Thornton, Tony N.; McCool, A. (Technical Monitor)

    2000-01-01

    The Thiokol, Science and Engineering Huntsville Operations (SEHO) Laboratory has previously experienced significant levels of variation in testing Quadruple Lap Shear (QLS) specimens. The QLS test is used at Thiokol / Utah for the qualification of Reusable Solid Rocket Motor (RSRM) nozzle flex bearing materials. A test was conducted to verify that process changes instituted by SEHO personnel effectively reduced variability, even with normal processing variables introduced. A test matrix was designed to progress in a series of steps; the first establishing a baseline, then introducing additional solvents or other variables. Variables included normal test plan delay times, pre-bond solvent hand-wipes and contaminants. Each condition tested utilized standard QLS hardware bonded with natural rubber, two separate technicians and three replicates. This paper will report the results and conclusions of this investigation.

  1. Association of Lipid Accumulation Product with Cardio-Metabolic Risk Factors in Postmenopausal Women.

    PubMed

    Namazi Shabestari, Alireza; Asadi, Mojgan; Jouyandeh, Zahra; Qorbani, Mostafa; Kelishadi, Roya

    2016-06-01

    The lipid accumulation product is a novel, safe and inexpensive index of central lipid over accumulation based on waist circumference and fasting concentration of circulating triglycerides. This study was designed to investigate the ability of lipid accumulation product to predict Cardio-metabolic risk factors in postmenopausal women. In this Cross-sectional study, 264 postmenopausal women by using convenience sampling method were selected from menopause clinic in Tehran. Cardio-metabolic risk factors were measured, and lipid accumulation product (waist-58×triglycerides [nmol/L]) was calculated. Optimal cut-off point of lipid accumulation product for predicting metabolic syndrome was estimated by ROC (Receiver-operating characteristic) curve analysis. Metabolic syndrome was diagnosed in 41.2% of subjects. Optimal cut-off point of lipid accumulation product for predicting metabolic syndrome was 47.63 (sensitivity:75%; specificity:77.9%). High lipid accumulation product increases risk of all Cardio-metabolic risk factors except overweight, high Total Cholesterol, high Low Density Lipoprotein Cholesterol and high Fasting Blood Sugar in postmenopausal women. Our findings show that lipid accumulation product is associated with metabolic syndrome and some Cardio-metabolic risk factors Also lipid accumulation product may have been a useful tool for predicting cardiovascular disease and metabolic syndrome risk in postmenopausal women. PMID:27306343

  2. Advanced Glycation End-Product Accumulation Reduces Vitreous Permeability

    PubMed Central

    Lee, On-Tat; Good, Samuel D.; Lamy, Ricardo; Kudisch, Max; Stewart, Jay M.

    2015-01-01

    Purpose. To evaluate the effect of nonenzymatic cross-linking (glycation) upon the permeability of the vitreous to small- and large-solute diffusion. Methods. Vitreous from freshly excised porcine eyes was treated for 30 minutes with control or 0.01%, 0.1%, or 1% methylglyoxal (MG) solution. The efficacy of the glycation regimen was verified by measuring nonenzymatic cross-link density by fluorescence in the vitreous samples. Resistance to collagenase digestion as well as Nε-(carboxyethyl) lysine (CEL) content were also measured. The permeability coefficient for fluorescein and fluorescein isothiocyanate (FITC)-IgG diffusion through 3 mL of the vitreous samples was determined by using a custom permeability tester. Results. Vitreous cross-linking with MG treatment was confirmed by increased fluorescence, increased CEL concentration, and increased resistance to collagenase digestion. Vitreous glycation resulted in a statistically significant decrease in the permeability coefficient for fluorescein diffusion when either 0.1% or 1% MG solution was used (5.36 ± 5.24 × 10−5 cm s−1, P = 0.04; and 4.03 ± 2.1 × 10−5 cm s−1, P = 0.001; respectively, compared with control, 9.77 ± 5.45 × 10−5 cm s−1). The permeability coefficient for diffusion of FITC-IgG between control (9.9 ± 6.37 × 10−5 cm s−1) and treatment groups was statistically significant at all MG concentrations (0.01% MG: 3.95 ± 3.44 × 10−5 cm s−1, P = 0.003; 0.1% MG: 4.27 ± 1.32 × 10−5 cm s−1, P = 0.004; and 0.1% MG: 3.72 ± 2.49 × 10−5 cm s−1, P = 0.001). Conclusions. Advanced glycation end-product (AGE) accumulation reduces vitreous permeability when glycation is performed in ex vivo porcine vitreous. The permeability change was more pronounced for the larger solute, suggesting a lower threshold for AGE-induced permeability changes to impact the movement of proteins through the vitreous when compared with smaller molecules. PMID:26024075

  3. LAPS Grid generation and adaptation

    NASA Astrophysics Data System (ADS)

    Pagliantini, Cecilia; Delzanno, Gia Luca; Guo, Zehua; Srinivasan, Bhuvana; Tang, Xianzhu; Chacon, Luis

    2011-10-01

    LAPS uses a common-data framework in which a general purpose grid generation and adaptation package in toroidal and simply connected domains is implemented. The initial focus is on implementing the Winslow/Laplace-Beltrami method for generating non-overlapping block structured grids. This is to be followed by a grid adaptation scheme based on Monge-Kantorovich optimal transport method [Delzanno et al., J. Comput. Phys,227 (2008), 9841-9864], that equidistributes application-specified error. As an initial set of applications, we will lay out grids for an axisymmetric mirror, a field reversed configuration, and an entire poloidal cross section of a tokamak plasma reconstructed from a CMOD experimental shot. These grids will then be used for computing the plasma equilibrium and transport in accompanying presentations. A key issue for Monge-Kantorovich grid optimization is the choice of error or monitor function for equi-distribution. We will compare the Operator Recovery Error Source Detector (ORESD) [Lapenta, Int. J. Num. Meth. Eng,59 (2004) 2065-2087], the Tau method and a strategy based on the grid coarsening [Zhang et al., AIAA J,39 (2001) 1706-1715] to find an ``optimal'' grid. Work supported by DOE OFES.

  4. Calcium Causes Multimerization of the Large Adhesin LapF and Modulates Biofilm Formation by Pseudomonas putida

    PubMed Central

    Martínez-Gil, Marta; Romero, Diego; Kolter, Roberto

    2012-01-01

    LapF is a large secreted protein involved in microcolony formation and biofilm maturation in Pseudomonas putida. Its C-terminal domain shows the characteristics of proteins secreted through a type I secretion system and includes a predicted calcium binding motif. We provide experimental evidence of specific binding of Ca2+ to the purified C-terminal domain of LapF (CLapF). Calcium promotes the formation of large aggregates, which disappear in the presence of the calcium chelator EGTA. Immunolocalization of LapF also shows the tendency of this protein to accumulate in vivo in certain extracellular regions. These findings, along with results showing that calcium influences biofilm formation, lead us to propose a model in which P. putida cells interact with each other via LapF in a calcium-dependent manner during the development of biofilms. PMID:23042991

  5. Strength and Efficiency during Lap Joining molding of GMT-Sheet

    NASA Astrophysics Data System (ADS)

    Kim, Jin-Woo; Kim, Hyoung-Seok; Lee, Dong-Gi

    2010-06-01

    In order to substitute and recycle the existing automobile parts for GMT-Sheet, researches on the effects of GMT-Sheet on the establishment of precise joining strength, joining condition that are lap length of joining part, compression ratio, and closure speed must be carried out but until now, there is almost no case of systematic researches on joint of GMT-Sheet. Therefore, as there are many obstacles in joining of GMT-Sheet molding products or in production of stable molding products, the researches on these issues are required. Because of this, it is reality that GMT-Sheet is only applied to parts of newly developed automobiles instead of substituting the existing automobile parts. In this study, materials with each different fiber content ratio and fiber orientation state were used in the study for decision of molding condition of GMT-Sheet and the condition of lap joining. Clarify joining strength and lap joining efficiency during high temperature. Compression press lap joining molding of GMT-Sheet and research data regarding to the lap length of joining part was presented. Thus, the purpose of this study is to contribute to the substitution of existing products as well as usage development in non-automobile field and also to find out precise dynamic characteristics as designing data of structures.

  6. 40 CFR 86.426-78 - Service accumulation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... manufacturer's recommended shifting procedure will be used for laps 1 through 10. Lap 11 shifts (W.O.T... mass which is within 5 kg (11.0 lb) of the loaded vehicle mass specified by the Administrator. (b) During service accumulation, vehicles shall not be operated for more than 12 hours during an...

  7. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Lap-joint seam boilers. 230.30 Section 230.30... Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams... annual inspection so that an inspection of the entire joint, inside and out, can be made, taking...

  8. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Lap-joint seam boilers. 230.30 Section 230.30... Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams... annual inspection so that an inspection of the entire joint, inside and out, can be made, taking...

  9. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Lap-joint seam boilers. 230.30 Section 230.30... Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams... annual inspection so that an inspection of the entire joint, inside and out, can be made, taking...

  10. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Lap-joint seam boilers. 230.30 Section 230.30... Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams... annual inspection so that an inspection of the entire joint, inside and out, can be made, taking...

  11. 49 CFR 230.30 - Lap-joint seam boilers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Lap-joint seam boilers. 230.30 Section 230.30..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal...

  12. Mini-review: the morphology, mineralogy and microbiology of accumulated iron corrosion products.

    PubMed

    Little, Brenda J; Gerke, Tammie L; Lee, Jason S

    2014-09-01

    Despite obvious differences in morphology, substratum chemistry and the electrolyte in which they form, accumulations of iron corrosion products have the following characteristics in common: stratification of iron oxides/hydroxides with a preponderance of α-FeOOH (goethite) and accumulation of metals. Bacteria, particularly iron-oxidizing and sulfate-reducing bacteria have been identified in some accumulations. Both biotic and abiotic mechanisms have been used to rationalize observations for particular sets of environmental data. This review is the first to compare observations and interpretations. PMID:25271874

  13. Mini-review: the morphology, mineralogy and microbiology of accumulated iron corrosion products

    PubMed Central

    Little, Brenda J.; Gerke, Tammie L.; Lee, Jason S.

    2014-01-01

    Despite obvious differences in morphology, substratum chemistry and the electrolyte in which they form, accumulations of iron corrosion products have the following characteristics in common: stratification of iron oxides/hydroxides with a preponderance of α-FeOOH (goethite) and accumulation of metals. Bacteria, particularly iron-oxidizing and sulfate-reducing bacteria have been identified in some accumulations. Both biotic and abiotic mechanisms have been used to rationalize observations for particular sets of environmental data. This review is the first to compare observations and interpretations. PMID:25271874

  14. Pseudomonas putida Fis Binds to the lapF Promoter In Vitro and Represses the Expression of LapF

    PubMed Central

    Lahesaare, Andrio; Moor, Hanna; Kivisaar, Maia; Teras, Riho

    2014-01-01

    The biofilm matrix of the rhizospheric bacterium Pseudomonas putida consists mainly of a proteinaceous component. The two largest P. putida proteins, adhesins LapA and LapF, are involved in biofilm development but prevail in different developmental stages of the biofilm matrix. LapA is abundant in the initial stage of biofilm formation whereas LapF is found in the mature biofilm. Although the transcriptional regulation of the adhesins is not exhaustively studied, some factors that can be involved in their regulation have been described. For example, RpoS, the major stress response sigma factor, activates, and Fis represses LapF expression. This study focused on the LapF expression control by Fis. Indeed, using DNase I footprint analysis a Fis binding site Fis-F2 was located 150 bp upstream of the lapF gene coding sequence. The mapped 5′ end of the lapF mRNA localized the promoter to the same region, overlapping with the Fis binding site Fis-F2. Monitoring the lapF promoter activity by a β-galactosidase assay revealed that Fis overexpression causes a 4-fold decrease in the transcriptional activity. Furthermore, mutations that diminished Fis binding to the Fis-F2 site abolished the repression of the lapF promoter. Thus, these data suggest that Fis is involved in the biofilm regulation via repression of LapF expression. PMID:25545773

  15. Production of polyhydroxyalkanoates by glycogen accumulating organisms treating a paper mill wastewater.

    PubMed

    Bengtsson, Simon; Werker, Alan; Welander, Thomas

    2008-01-01

    A process for production of polyhydroxyalkanoates (PHA) by activated sludge treating a paper mill wastewater was investigated. The applied strategy was to select for glycogen accumulating organisms (GAOs) by alternating anaerobic/aerobic conditions. Acidogenic fermentation was used as pretreatment to convert various organic compounds to volatile fatty acids which are preferable substrates for PHA production. Enrichment resulted in a culture dominated by GAOs related to Defluviicoccus vanus (56%) and Candidatus Competibacter phosphatis (22%). Optimization of PHA accumulation by the enriched GAO culture was performed through batch experiments. Accumulation of PHA under anaerobic conditions was limited by the intracellular glycogen stored. Under aerobic conditions significant glycogen production (to 25% of sludge dry weight) was observed alongside PHA accumulation (to 22% of sludge dry weight). By applying a subsequent anaerobic period after an initial aerobic, the produced glycogen could be utilized for further PHA accumulation and by this strategy PHA content was increased to 42% of sludge dry weight. The PHA yield over the entire process was 0.10 kg per kg of influent COD treated which is similar to what has been achieved with a process applying feast/famine enrichment strategy with the same wastewater. PMID:18701781

  16. A new cultivation method for microbial oil production: cell pelletization and lipid accumulation by Mucor circinelloides

    PubMed Central

    2011-01-01

    The recent energy crisis has triggered significant attention on the microbial synthesis of lipids, which comprise the raw material for biodiesel production. Microbial oil accumulation with filamentous fungi has great potential because filamentous fungi can form pellets during cell growth, and these pellets are much easier to harvest from cell broth. This paper focuses on the cell pelletization process of the oleaginous Mucor circinelloides. We have studied the effect of various cultural conditions on pelletized cell growth and lipid accumulation. This study is the first to report that pH adjustment during cell growth plays a key role in pellet formation of M. circinelloides and describes a handy method by which to induce cell pelletization in submerged fungal cultivation. Our study reveals that cell growth and lipid production are not significantly affected by pelletization and that lipid accumulation is triggered at stressed conditions, such as a high carbon-to-nitrogen ratio and high temperature. PMID:21635739

  17. Stillage reflux in food waste ethanol fermentation and its by-product accumulation.

    PubMed

    Ma, Hongzhi; Yang, Jian; Jia, Yan; Wang, Qunhui; Tashiro, Yukihiro; Sonomoto, Kenji

    2016-06-01

    Raw materials and pollution control are key issues for the ethanol fermentation industry. To address these concerns, food waste was selected as fermentation substrate, and stillage reflux was carried out in this study. Reflux was used seven times during fermentation. Corresponding ethanol and reducing sugar were detected. Accumulation of by-products, such as organic acid, sodium chloride, and glycerol, was investigated. Lactic acid was observed to accumulate up to 120g/L, and sodium chloride reached 0.14mol/L. Other by-products did not accumulate. The first five cycles of reflux increased ethanol concentration, which prolonged fermentation time. Further increases in reflux time negatively influenced ethanol fermentation. Single-factor analysis with lactic acid and sodium chloride demonstrated that both factors affected ethanol fermentation, but lactic acid induced more effects. PMID:26974357

  18. Learning Activity Package, Physical Science. LAP Numbers 5, 6, and 7.

    ERIC Educational Resources Information Center

    Williams, G. J.

    These three units of the Learning Activity Packages (LAPs) for individualized instruction in physical science cover the physical and chemical properties of water, dehydration of crystals, solutions, acidity, strong and weak bases, neutral properties of salts, amorphous forms of carbon, hydrocarbons, and petroleum products. Each unit contains a…

  19. p-Synephrine Suppresses Glucose Production but Not Lipid Accumulation in H4IIE Liver Cells

    PubMed Central

    Cui, Zhigang; Lee, Youngil; Lee, Youngki

    2015-01-01

    Abstract p-Synephrine, the primary protoalkaloid in the extract of bitter orange and other citrus species, has gained interest due to its lipolytic activity in adipose tissues. We previously found that p-synephrine stimulates glucose consumption via AMP-activated protein kinase (AMPK) in L6 skeletal muscle cells. This study investigated the effect of p-synephrine on glucose production and lipid accumulation in H4IIE rat liver cells. Glucose production was increased in H4llE cells that were incubated in glucose-free medium but decreased dose dependently (1–100 μM) with p-synephrine treatment. Protein levels of glucose-6-phosphatase (G6Pase) and phosphoenol pyruvate carboxykinase (PEPCK) were also decreased by treatment (4 h) with p-synephrine. Antagonists against α- and β-adrenergic receptors (phentolamine and propranolol) and other inhibitors against signaling molecules did not interrupt p-synephrine-induced suppression in glucose production. However, H7 (an inhibitor of serine/threonine kinases PKA, PKC, and PKG) significantly blocked p-synephrine-induced suppression of glucose production and further increased basal glucose production. Unlike the suppressive effect on glucose production, p-synephrine failed to affect palmitic acid-induced cytoplasmic lipid accumulation. Protein levels of fatty acid synthase (FAS) and phosphorylation levels of AMPK and ACC were not changed by p-synephrine. Altogether, p-synephrine can suppress glucose production but does not affect lipid accumulation in H4IIE liver cells. PMID:25379695

  20. Homologs of the LapD-LapG c-di-GMP Effector System Control Biofilm Formation by Bordetella bronchiseptica

    PubMed Central

    Ambrosis, Nicolás; Boyd, Chelsea D.; O´Toole, George A.; Fernández, Julieta; Sisti, Federico

    2016-01-01

    Biofilm formation is important for infection by many pathogens. Bordetella bronchiseptica causes respiratory tract infections in mammals and forms biofilm structures in nasal epithelium of infected mice. We previously demonstrated that cyclic di-GMP is involved in biofilm formation in B. bronchiseptica. In the present work, based on their previously reported function in Pseudomonas fluorescens, we identified three genes in the B. bronchiseptica genome likely involved in c-di-GMP-dependent biofilm formation: brtA, lapD and lapG. Genetic analysis confirmed a role for BrtA, LapD and LapG in biofilm formation using microtiter plate assays, as well as scanning electron and fluorescent microscopy to analyze the phenotypes of mutants lacking these proteins. In vitro and in vivo studies showed that the protease LapG of B. bronchiseptica cleaves the N-terminal domain of BrtA, as well as the LapA protein of P. fluorescens, indicating functional conservation between these species. Furthermore, while BrtA and LapG appear to have little or no impact on colonization in a mouse model of infection, a B. bronchiseptica strain lacking the LapG protease has a significantly higher rate of inducing a severe disease outcome compared to the wild type. These findings support a role for c-di-GMP acting through BrtA/LapD/LapG to modulate biofilm formation, as well as impact pathogenesis, by B. bronchiseptica PMID:27380521

  1. Methane dynamics in a montane fen: Factors controlling production, accumulation and emissions

    NASA Astrophysics Data System (ADS)

    Mwakanyamale, K. E.; Yeung, H.; Strack, M.

    2014-12-01

    Characterization of methane dynamics in peatlands is essential to improve understanding of peatlands contribution to carbon balance and interaction with climate. Of the two peatland types, natural fens are known to be a larger contributor of methane emissions to the atmosphere than natural bogs. This study uses geophysical methods integrated with in-situ direct measurements and chamber fluxes to improve understanding of temporal and spatial variation in methane production, accumulation and emissions from natural montane fen in Alberta Canada. Meteorological data and peat cores (~150 cm) were collected to study factors affecting methane production, accumulation and emissions from the Sibbald Research Wetland, a montane fen in the Rocky Mountains in southern Alberta. Our results show a direct correlation between methane accumulation and degree of peat humification, substrate quality and porosity. Changes in temperature, pressure and water table position were shown to relate to ebullition events, with the highest number of ebullition events occurring from late August to early November. The geophysical results indicate a small spatial variation in free phase biogenic gas accumulation within the studied area. Diffusive methane fluxes were correlated to plant productivity on both daily and seasonal time scales with patterns varying between plots dominated by Juncus sp. and Carex spp. These results highlight the interacting ecological and physical controls on peatland methane dynamics.

  2. A study on the diamond lapping direction determination

    NASA Astrophysics Data System (ADS)

    Yang, Ning; Zong, WenJun; Li, ZengQiang; Sun, Tao

    2014-08-01

    The anisotropy of material removal rate for diamond gives a method to control the lapping rate of diamond specimen, i.e. changing the lapping direction. This requires comprehension on the relationship of the material removal rate and the lapping direction for diamond. This paper provides a method to figure out the diamond lapping direction. By preprocessing a straight edge formed by lapping a surface intersects with the required machining surface, the diamond lapping direction can be figured out under the Confocal Scanning Laser Microscope only if the crystal directions of the two surfaces are determined at first. The advantage of our method is that there is no need to consider the position and posture of the diamond specimen fixed on the holder.

  3. Dogs lap using acceleration-driven open pumping

    PubMed Central

    Gart, Sean; Socha, John J.; Vlachos, Pavlos P.; Jung, Sunghwan

    2015-01-01

    Dogs lap because they have incomplete cheeks and cannot suck. When lapping, a dog’s tongue pulls a liquid column from the bath, suggesting that the hydrodynamics of column formation are critical to understanding how dogs drink. We measured lapping in 19 dogs and used the results to generate a physical model of the tongue’s interaction with the air–fluid interface. These experiments help to explain how dogs exploit the fluid dynamics of the generated column. The results demonstrate that effects of acceleration govern lapping frequency, which suggests that dogs curl the tongue to create a larger liquid column. Comparing lapping in dogs and cats reveals that, despite similar morphology, these carnivores lap in different physical regimes: an unsteady inertial regime for dogs and steady inertial regime for cats. PMID:26668382

  4. Systematic Construction of Real Lapped Tight Frame Transforms

    PubMed Central

    Sandryhaila, Aliaksei; Chebira, Amina; Milo, Christina; Kovčcević, Jelena; Püschel, Markus

    2010-01-01

    We present a constructive algorithm for the design of real lapped equal-norm tight frame transforms. These transforms can be efficiently implemented through filter banks and have recently been proposed as a redundant counterpart to lapped orthogonal transforms, as well as an infinite-dimensional counterpart to harmonic tight frames. The proposed construction consists of two parts: First, we design a large class of new real lapped orthogonal transforms derived from submatrices of the discrete Fourier transform. Then, we seed these to obtain real lapped tight frame transforms corresponding to tight, equal-norm frames. We identify those frames that are maximally robust to erasures, and show that our construction leads to a large class of new lapped orthogonal transforms as well as new lapped tight frame transforms. PMID:20607116

  5. Dogs lap using acceleration-driven open pumping.

    PubMed

    Gart, Sean; Socha, John J; Vlachos, Pavlos P; Jung, Sunghwan

    2015-12-29

    Dogs lap because they have incomplete cheeks and cannot suck. When lapping, a dog's tongue pulls a liquid column from the bath, suggesting that the hydrodynamics of column formation are critical to understanding how dogs drink. We measured lapping in 19 dogs and used the results to generate a physical model of the tongue's interaction with the air-fluid interface. These experiments help to explain how dogs exploit the fluid dynamics of the generated column. The results demonstrate that effects of acceleration govern lapping frequency, which suggests that dogs curl the tongue to create a larger liquid column. Comparing lapping in dogs and cats reveals that, despite similar morphology, these carnivores lap in different physical regimes: an unsteady inertial regime for dogs and steady inertial regime for cats. PMID:26668382

  6. New design deforming controlling system of the active stressed lap

    NASA Astrophysics Data System (ADS)

    Ying, Li; Wang, Daxing

    2008-07-01

    A 450mm diameter active stressed lap has been developed in NIAOT by 2003. We design a new lap in 2007. This paper puts on emphases on introducing the new deforming control system of the lap. Aiming at the control characteristic of the lap, a new kind of digital deforming controller is designed. The controller consists of 3 parts: computer signal disposing, motor driving and force sensor signal disposing. Intelligent numeral PID method is applied in the controller instead of traditional PID. In the end, the result of new deformation are given.

  7. Diamond machine tool face lapping machine

    DOEpatents

    Yetter, H.H.

    1985-05-06

    An apparatus for shaping, sharpening and polishing diamond-tipped single-point machine tools. The isolation of a rotating grinding wheel from its driving apparatus using an air bearing and causing the tool to be shaped, polished or sharpened to be moved across the surface of the grinding wheel so that it does not remain at one radius for more than a single rotation of the grinding wheel has been found to readily result in machine tools of a quality which can only be obtained by the most tedious and costly processing procedures, and previously unattainable by simple lapping techniques.

  8. Bending behavior of lapped plastic ehv cables

    SciTech Connect

    Morgan, G H; Muller, A C

    1980-01-01

    One of the factors delaying the development of lapped polymeric cables has been their reputed poor bending characteristics. Complementary programs were begun at BNL several years ago to mathematically model the bending of synthetic tape cables and to develop novel plastic tapes designed to have moduli more favorable to bending. A series of bend tests was recently completed to evaluate the bending performance of several tapes developed for use in experimental superconducting cables. The program is discussed and the results of the bend tests are summarized.

  9. Analysis of adhesively bonded composite lap joints

    SciTech Connect

    Tong, L.; Kuruppu, M.; Kelly, D.

    1994-12-31

    A new nonlinear formulation is developed for the governing equations for the shear and peel stresses in adhesively bonded composite double lap joints. The new formulation allows arbitrary nonlinear stress-strain characteristics in both shear and peel behavior. The equations are numerically integrated using a shooting technique and Newton-Raphson method behind a user friendly interface. The failure loads are predicted by utilizing the maximum stress criterion, interlaminar delamination and the energy density failure criteria. Numerical examples are presented to demonstrate the effect of the nonlinear adhesive behavior on the stress distribution and predict the failure load and the associated mode.

  10. Modulated lapped transforms in image coding

    NASA Astrophysics Data System (ADS)

    de Queiroz, Ricardo L.; Rao, K. R.

    1994-05-01

    The class of modulated lapped transforms (MLT) with extended overlap is investigated in image coding. The finite-length-signals implementation using symmetric extensions is introduced and human visual sensitivity arrays are computed. Theoretical comparisons with other popular transforms are carried and simulations are made using intraframe coders. Emphasis is given in transmission over packet networks assuming high rate of data losses. The MLT with overlap factor 2 is shown to be superior in all our tests with bonus features such as greater robustness against block losses.

  11. Net ecosystem production: A comprehensive measure of net carbon accumulation by ecosystems

    USGS Publications Warehouse

    Randerson, J.T.; Chapin, F. S., III; Harden, J.W.; Neff, J.C.; Harmon, M.E.

    2002-01-01

    The conceptual framework used by ecologists and biogeochemists must allow for accurate and clearly defined comparisons of carbon fluxes made with disparate techniques across a spectrum of temporal and spatial scales. Consistent with usage over the past four decades, we define "net ecosystem production" (NEP) as the net carbon accumulation by ecosystems. Past use of this term has been ambiguous, because it has been used conceptually as a measure of carbon accumulation by ecosystems, but it has often been calculated considering only the balance between gross primary production (GPP) and ecosystem respiration. This calculation ignores other carbon fluxes from ecosystems (e.g., leaching of dissolved carbon and losses associated with disturbance). To avoid conceptual ambiguities, we argue that NEP be defined, as in the past, as the net carbon accumulation by ecosystems and that it explicitly incorporate all the carbon fluxes from an ecosystem, including autotrophic respiration, heterotrophic respiration, losses associated with disturbance, dissolved and particulate carbon losses, volatile organic compound emissions, and lateral transfers among ecosystems. Net biome productivity (NBP), which has been proposed to account for carbon loss during episodic disturbance, is equivalent to NEP at regional or global scales. The multi-scale conceptual framework we describe provides continuity between flux measurements made at the scale of soil profiles and chambers, forest inventories, eddy covariance towers, aircraft, and inversions of remote atmospheric flask samples, allowing a direct comparison of NEP estimates made at all temporal and spatial scales.

  12. Determination of the Corrosive Conditions Present within Aircraft Lap-Splice Joints

    NASA Technical Reports Server (NTRS)

    Lewis, Karen S.; Kelly, Robert G.; Piascik, Robert S.

    1999-01-01

    The complexity of airframe structure lends itself to damage resulting from crevice corrosion. Fuselage lap-splice joints are a particularly important structural detail in this regard because of the difficulty associated with detection and measurement of corrosion in these occluded regions. The objective of this work is to develop a laboratory corrosion test protocol to identify the chemistry to which lap joints are exposed and to develop a model of the corrosion within the joints. A protocol for collecting and identifying the chemistry of airframe crevice corrosion has been developed. Capillary electrophoresis (CE) is used to identify the ionic species contained in corrosion product samples removed from fuselage lap splice joints. CE analysis has been performed on over sixty corrosion product samples removed from both civilian and military aircraft. Over twenty different ions have been detected. Measurements of pH of wetted corroded surfaces indicated an alkaline occluded solution. After determining the species present and their relative concentrations, the resultant solution was reproduced in bulk and electrochemical tests were performed to determine the corrosion rate. Electrochemical analyses of the behavior of AA2024-T3 in these solutions gave corrosion rates of up to 250 microns per year (10 mpy). Additional tests have determined the relative importance of each of the detected ions in model solutions used for future predictive tests. The statistically significant ions have been used to create a second generation solution. Laboratory studies have also included exposure tests involving artificial lap joints exposed to various simulated bulk and crevice environments. The extent and morphology of the attack in artificial lap joints has been compared to studies of corroded samples from actual aircraft. Other effects, such as temperature and potential, as well as the impact of the environment on fatigue crack growth have also been studied.

  13. The influence of light intensity and photoperiod on duckweed biomass and starch accumulation for bioethanol production.

    PubMed

    Yin, Yehu; Yu, Changjiang; Yu, Li; Zhao, Jinshan; Sun, Changjiang; Ma, Yubin; Zhou, Gongke

    2015-01-01

    Duckweed has been considered as a valuable feedstock for bioethanol production due to its high biomass and starch production. To investigate the effects of light conditions on duckweed biomass and starch production, Lemna aequinoctialis 6000 was cultivated at different photoperiods (12:12, 16:8 and 24:0h) and light intensities (20, 50, 80, 110, 200 and 400μmolm(-2)s(-1)). The results showed that the duckweed biomass and starch production was increased with increasing light intensity and photoperiod except at 200 and 400μmolm(-2)s(-1). Considering the light cost, 110μmolm(-2)s(-1) was optimum light condition for starch accumulation with the highest maximum growth rate, biomass and starch production of 8.90gm(-2)day(-1), 233.25gm(-2) and 98.70gm(-2), respectively. Moreover, the results suggested that high light induction was a promising method for duckweed starch accumulation. This study provides optimized light conditions for future industrial large-scale duckweed cultivation. PMID:25841186

  14. Accumulation of Pyrimidine Intermediate Orotate Decreases Virulence Factor Production in Pseudomonas aeruginosa.

    PubMed

    Niazy, Abdurahman; Hughes, Lee E

    2015-08-01

    The impact of orotate accumulation in the medically important bacterium Pseudomonas aeruginosa was studied by deleting pyrE, the gene encoding orotate phosphoribosyltransferase and responsible for converting orotate into orotate monophosphate within the de novo pyrimidine synthesis pathway. The pyrE mutant accumulated orotate and exhibited decreased production of hemolysin, casein protease, and elastase. Feeding orotate at a concentration of 51.25 μM to the wild type, PAO1, likewise decreased production of these factors except for hemolysin, which was not affected. A significant increase in the pigments pyocyanin and pyoverdin was also observed. Pyocyanin increase in the pyrE mutant was heightened when the mutant was supplemented with orotate. Although pyoverdin production in the wild-type PAO1 was unaffected by orotate supplementation, a decrease in the mutant's production was observed when supplemented with orotate. These results indicate a significant reduction in virulence factor production in the pyrE mutant and reduction in some virulence factors in the wild type when supplemented with orotate. PMID:25917504

  15. Isolation and Characterization of the Neutral Leucine Aminopeptidase (LapN) of Tomato1

    PubMed Central

    Tu, Chao-Jung; Park, Sang-Youl; Walling, Linda L.

    2003-01-01

    Tomatoes (Lycopersicon esculentum) express two forms of leucine aminopeptidase (LAP-A and LAP-N) and two LAP-like proteins. The relatedness of LAP-N and LAP-A was determined using affinity-purified antibodies to four LAP-A protein domains. Antibodies to epitopes in the most N-terminal region were able to discriminate between LAP-A and LAP-N, whereas antibodies recognizing central and COOH-terminal regions recognized both LAP polypeptides. Two-dimensional immunoblots showed that LAP-N and the LAP-like proteins were detected in all vegetative (leaves, stems, roots, and cotyledons) and reproductive (pistils, sepals, petals, stamens, and floral buds) organs examined, whereas LAP-A exhibited a distinct expression program. LapN was a single-copy gene encoding a rare-class transcript. A full-length LapN cDNA clone was isolated, and the deduced sequence had 77% peptide sequence identity with the wound-induced LAP-A. Comparison of LAP-N with other plant LAPs identified 28 signature residues that classified LAP proteins as LAP-N or LAP-A like. Overexpression of a His6-LAP-N fusion protein in Escherichia coli demonstrated distinct differences in His6-LAP-N and His6-LAP-A activities. Similar to LapA, the LapN RNA encoded a precursor protein with a molecular mass of 60 kD. The 5-kD presequence had features similar to plastid transit peptides, and processing of the LAP-N presequence could generate the mature 55-kD LAP-N. Unlike LapA, the LapN transcript contained a second in-frame ATG, and utilization of this potential initiation codon would yield a 55-kD LAP-N protein. The localization of LAP-N could be controlled by the balance of translational initiation site utilization and LAP-N preprotein processing. PMID:12746529

  16. How dogs lap: open pumping driven by acceleration

    NASA Astrophysics Data System (ADS)

    Gart, Sean; Socha, John; Vlachos, Pavlos; Jung, Sunghwan

    2015-11-01

    Dogs drink by lapping because they have incomplete cheeks and cannot suck fluids into the mouth. When lapping, a dog's tongue pulls a liquid column from a bath, which is then swallowed, suggesting that the hydrodynamics of column formation are critical to understanding how dogs drink. We measured the kinematics of lapping from nineteen dogs and used the results to generate a physical model of the tongue's interaction with the air-fluid interface. These experiments with an accelerating rod help to explain how dogs exploit the fluid dynamics of the generated column. The results suggest that effects of acceleration govern lapping frequency, and that dogs curl the tongue ventrally (backwards) and time their bite on the column to increase fluid intake per lap. Comparing lapping in dogs and cats reveals that though they both lap with the same frequency scaling with respect to body mass and have similar morphology, these carnivores lap in different physical regimes: a high-acceleration regime for dogs and a low-acceleration regime for cats.

  17. Learning Activity Package, Chemistry I, (LAP) Study 29.

    ERIC Educational Resources Information Center

    Jones, Naomi

    Presented is a Learning Activity Package (LAP) study concerned with carbon and its compounds. This LAP in chemistry includes a rationale for studying the chemical element of carbon, a list of student objectives (stated in behavioral terms), of activities (reading, laboratory experiments, model construction, etc.), a two-page worksheet, a…

  18. Design Document: KWIC Module; L.A.P. Version I.

    ERIC Educational Resources Information Center

    Porch, Ann

    The Language Analysis Package (LAP) was developed by the Southwest Regional Laboratory (SWRL) to assist researchers in the analysis of language usage. The function of the KWIC (Keyword-in Context or Concordance) Module of the LAP is to produce keyword listings from the input text being analyzed. Such listings will contain location information…

  19. Experimental study on lapping of micro groove with controlled force

    NASA Astrophysics Data System (ADS)

    Ding, Fei; Wang, Bo; Li, Guo; Che, Lin; Mao, Xing

    2014-08-01

    Precision parts with complicated microstructures have been in increasing demand in the field of inertial navigation systems and structured molds. Micro milling is a direct operation to manufacture the micro structure but it will induce unexpected tool marks and deterioration layer. A novel lapping method based on controlled force is proposed as the final finishing process. The method offers efficient position determination strategy for the structure and is capable to monitor the lapping condition. In the paper, processing method and the developed lapping apparatus was firstly introduced. Then, the individual influence on finished surface of several processing parameters including abrasive size, amount of feed and lapping trajectory are investigated. Results show that the deterioration layer was successfully removed with different slurries without diminution of its original form accuracy. Lapping efficiency is also taken into account in the choosing of parameters. The formative mechanism of parallel scratches observed in experiments is analyzed and verified.

  20. The Use of Horizontal Wells in Gas Production from Hydrate Accumulations

    SciTech Connect

    Reagan, Matthew; Moridis, George J.; Reagan, Matthew T.; Zhang, Keni

    2008-04-15

    The amounts of hydrocarbon gases trapped in natural hydrate accumulations are enormous, leading to a recent interest in the evaluation of their potential as an energy source. Earlier studies have demonstrated that large volumes of gas can be readily produced at high rates for long times from gas hydrate accumulations by means of depressurization-induced dissociation, using conventional technology and vertical wells. The results of this numerical study indicate that the use of horizontal wells does not confer any practical advantages to gas production from Class 1 deposits. This is because of the large disparity in permeabilities between the hydrate layer (HL) and the underlying free gas zone, leading to a hydrate dissociation that proceeds in a horizontally dominant direction and is uniform along the length of the reservoir. When horizontal wells are placed near the base of the HL in Class 2 deposits, the delay in the evolution of a significant gas production rate outweighs their advantages, which include higher rates and the prevention of flow obstruction problems that often hamper the performance of vertical wells. Conversely, placement of a horizontal well near to top of the HL can lead to dramatic increases in gas production from Class 2 and Class 3 deposits over the corresponding production from vertical wells.

  1. Characteristic of nitrous oxide production in partial denitrification process with high nitrite accumulation.

    PubMed

    Du, Rui; Peng, Yongzhen; Cao, Shenbin; Wang, Shuying; Niu, Meng

    2016-03-01

    Nitrous oxide (N2O) production during the partial denitrification process with nitrate (NO3(-)-N) to nitrite (NO2(-)-N) transformation ratio of 80% was investigated in this study. Results showed that N2O was seldom observed before complete depletion of NO3(-)-N, but it was closely related to the reduction of NO2(-)-N rather than NO3(-)-N. High COD/NO3(-)-N was in favor of N2O production in partial denitrification with high NO2(-)-N accumulation. It was seriously enhanced at constant acidic pH due to the free nitrous acid (FNA) inhibition. However, the N2O production was much lower at initial pH of 5.5 and 6.5 due to the pH increase during denitrification process. Significantly, the pH turning point could be chosen as a controlled parameter to denote the end of NO3(-)-N reduction, which could not only achieve high NO2(-)-N accumulation but also decrease the N2O production significantly for practical application. PMID:26760756

  2. Laboratory-scale bioaugmentation relieves acetate accumulation and stimulates methane production in stalled anaerobic digesters.

    PubMed

    Town, Jennifer R; Dumonceaux, Tim J

    2016-01-01

    An imbalance between acidogenic and methanogenic organisms during anaerobic digestion can result in increased accumulation of volatile fatty acids, decreased reactor pH, and inhibition of methane-producing Archaea. Most commonly the result of organic input overload or poor inoculum selection, these microbiological and biochemical changes severely hamper reactor performance, and there are a few tools available to facilitate reactor recovery. A small, stable consortium capable of catabolizing acetate and producing methane was propagated in vitro and evaluated as a potential bioaugmentation tool for stimulating methanogenesis in acidified reactors. Replicate laboratory-scale batch digesters were seeded with a combination of bioethanol stillage waste and a dairy manure inoculum previously observed to result in high volatile fatty acid accumulation and reactor failure. Experimental reactors were then amended with the acetoclastic consortium, and control reactors were amended with sterile culture media. Within 7 days, bioaugmented reactors had significantly reduced acetate accumulation and the proportion of methane in the biogas increased from 0.2 ± 0 to 74.4 ± 9.9 % while control reactors showed no significant reduction in acetate accumulation or increase in methane production. Organisms from the consortium were enumerated using specific quantitative PCR assays to evaluate their growth in the experimental reactors. While the abundance of hydrogenotrophic microorganisms remained stable during the recovery period, an acetoclastic methanogen phylogenetically similar to Methanosarcina sp. increased more than 100-fold and is hypothesized to be the primary contributor to reactor recovery. Genomic sequencing of this organism revealed genes related to the production of methane from acetate, hydrogen, and methanol. PMID:26481626

  3. Identification of a Novel Human LAP1 Isoform That Is Regulated by Protein Phosphorylation

    PubMed Central

    Santos, Mariana; Domingues, Sara C.; Costa, Patrícia; Muller, Thorsten; Galozzi, Sara; Marcus, Katrin; da Cruz e Silva, Edgar F.; da Cruz e Silva, Odete A.; Rebelo, Sandra

    2014-01-01

    Lamina associated polypeptide 1 (LAP1) is an integral protein of the inner nuclear membrane that is ubiquitously expressed. LAP1 binds to lamins and chromatin, probably contributing to the maintenance of the nuclear envelope architecture. Moreover, LAP1 also interacts with torsinA and emerin, proteins involved in DYT1 dystonia and X-linked Emery-Dreifuss muscular dystrophy disorder, respectively. Given its relevance to human pathological conditions, it is important to better understand the functional diversity of LAP1 proteins. In rat, the LAP1 gene (TOR1AIP1) undergoes alternative splicing to originate three LAP1 isoforms (LAP1A, B and C). However, it remains unclear if the same occurs with the human TOR1AIP1 gene, since only the LAP1B isoform had thus far been identified in human cells. In silico analysis suggested that, across different species, potential new LAP1 isoforms could be generated by alternative splicing. Using shRNA to induce LAP1 knockdown and HPLC-mass spectrometry analysis the presence of two isoforms in human cells was described and validated: LAP1B and LAP1C; the latter is putatively N-terminal truncated. LAP1B and LAP1C expression profiles appear to be dependent on the specific tissues analyzed and in cultured cells LAP1C was the major isoform detected. Moreover, LAP1B and LAP1C expression increased during neuronal maturation, suggesting that LAP1 is relevant in this process. Both isoforms were found to be post-translationally modified by phosphorylation and methionine oxidation and two LAP1B/LAP1C residues were shown to be dephosphorylated by PP1. This study permitted the identification of the novel human LAP1C isoform and partially unraveled the molecular basis of LAP1 regulation. PMID:25461922

  4. Enhanced decomposition offsets enhanced productivity and soil carbon accumulation in coastal wetlands responding to climate change

    USGS Publications Warehouse

    Kirwan, M.L.; Blum, L.K.

    2011-01-01

    Coastal wetlands are responsible for about half of all carbon burial in oceans, and their persistence as a valuable ecosystem depends largely on the ability to accumulate organic material at rates equivalent to relative sea level rise. Recent work suggests that elevated CO2 and temperature warming will increase organic matter productivity and the ability of marshes to survive sea level rise. However, we find that organic decomposition rates increase by about 12% per degree of warming. Our measured temperature sensitivity is similar to studies from terrestrial systems, twice as high as the response of salt marsh productivity to temperature warming, and roughly equivalent to the productivity response associated with elevated CO2 in C3 marsh plants. Therefore, enhanced CO2 and warmer temperatures may actually make marshes less resilient to sea level rise, and tend to promote a release of soil carbon. Simple projections indicate that elevated temperatures will increase rates of sea level rise more than any acceleration in organic matter accumulation, suggesting the possibility of a positive feedback between climate, sea level rise, and carbon emissions in coastal environments. ?? 2011 Author(s).

  5. Enhanced decomposition offsets enhanced productivity and soil carbon accumulation in coastal wetlands responding to climate change

    USGS Publications Warehouse

    Kirwan, M.L.; Blum, L.K.

    2011-01-01

    Coastal wetlands are responsible for about half of all carbon burial in oceans, and their persistence as a valuable ecosystem depends largely on the ability to accumulate organic material at rates equivalent to relative sea level rise. Recent work suggests that elevated CO2 and temperature warming will increase organic matter productivity and the ability of marshes to survive sea level rise. However, we find that organic decomposition rates increase by about 12% per degree of warming. Our measured temperature sensitivity is similar to studies from terrestrial systems, twice as high as the response of salt marsh productivity to temperature warming, and roughly equivalent to the productivity response associated with elevated CO2 in C3 marsh plants. Therefore, enhanced CO2 and warmer temperatures may actually make marshes less resilient to sea level rise, and tend to promote a release of soil carbon. Simple projections indicate that elevated temperatures will increase rates of sea level rise more than any acceleration in organic matter accumulation, suggesting the possibility of a positive feedback between climate, sea level rise, and carbon emissions in coastal environments.

  6. Influence of the Environmental Factors on the Accumulation of the Bioactive Ingredients in Chinese Rhubarb Products.

    PubMed

    Ren, Guangxi; Li, Li; Hu, Huijuan; Li, Yanpeng; Liu, Chunsheng; Wei, Shengli

    2016-01-01

    To provide a basis for controlling the quality of rhubarb under artificial cultivation, the present work was designed to evaluate the contents of 14 active pharmaceutical ingredients (API) of rhubarb in major rhubarb production areas in China and analyze the correlations between the contents of API and such factors as species, geographic distribution and soil. The levels of fourteen API in rhubarb were measured using HPLC. The geographic distributions were collected using GPS and the nutrients in the soil were measured using the methods in the literature. The results showed that the levels of major API vary significantly among plants of different locations according to variance analysis. The species factor has few obvious effect on the overall properties of the rhubarb by the cluster analysis because of the two source species occurring in all divided three groups. However, Rheum tanguticum Maxim.ex Balf. is less effective at synthesizing and accumulating 9 API out of 14 than Rheum palmatum L. The correlation analysis and regression analysis also indicated that a lower latitude should be considered in the accumulation of API and a lower longitude should be considered to produce more compound anthraquinones. Lower levels of total P, rapidly available P and available molybdenum (Mo) and higher available K and available Zn in the soil were significantly correlated to accumulation of API in rhubarb. These results provide a basis for the clinical application and controlling the levels of the major API of rhubarb during artificial cultivation. PMID:27138597

  7. Influence of the Environmental Factors on the Accumulation of the Bioactive Ingredients in Chinese Rhubarb Products

    PubMed Central

    Hu, Huijuan; Li, Yanpeng; Liu, Chunsheng; Wei, Shengli

    2016-01-01

    To provide a basis for controlling the quality of rhubarb under artificial cultivation, the present work was designed to evaluate the contents of 14 active pharmaceutical ingredients (API) of rhubarb in major rhubarb production areas in China and analyze the correlations between the contents of API and such factors as species, geographic distribution and soil. The levels of fourteen API in rhubarb were measured using HPLC. The geographic distributions were collected using GPS and the nutrients in the soil were measured using the methods in the literature. The results showed that the levels of major API vary significantly among plants of different locations according to variance analysis. The species factor has few obvious effect on the overall properties of the rhubarb by the cluster analysis because of the two source species occurring in all divided three groups. However, Rheum tanguticum Maxim.ex Balf. is less effective at synthesizing and accumulating 9 API out of 14 than Rheum palmatum L. The correlation analysis and regression analysis also indicated that a lower latitude should be considered in the accumulation of API and a lower longitude should be considered to produce more compound anthraquinones. Lower levels of total P, rapidly available P and available molybdenum (Mo) and higher available K and available Zn in the soil were significantly correlated to accumulation of API in rhubarb. These results provide a basis for the clinical application and controlling the levels of the major API of rhubarb during artificial cultivation. PMID:27138597

  8. Electron-cooled accumulation of 4 × 109 positrons for production and storage of antihydrogen atoms

    NASA Astrophysics Data System (ADS)

    Fitzakerley, D. W.; George, M. C.; Hessels, E. A.; Skinner, T. D. G.; Storry, C. H.; Weel, M.; Gabrielse, G.; Hamley, C. D.; Jones, N.; Marable, K.; Tardiff, E.; Grzonka, D.; Oelert, W.; Zielinski, M.; ATRAP Collaboration

    2016-03-01

    Four billion positrons (e+) are accumulated in a Penning-Ioffe trap apparatus at 1.2 K and <6 × 10-17 Torr. This is the largest number of positrons ever held in a Penning trap. The e+ are cooled by collisions with trapped electrons (e-) in this first demonstration of using e- for efficient loading of e+ into a Penning trap. The combined low temperature and vacuum pressure provide an environment suitable for antihydrogen (\\bar{{{H}}}) production, and long antimatter storage times, sufficient for high-precision tests of antimatter gravity and of CPT.

  9. Tubular lap joints for wind turbine applications

    SciTech Connect

    Reedy, E.D. Jr.; Guess, T.R.

    1990-01-01

    A combined analytical/experimental study of the strength of thick- walled, adhesively bonded PMMA-to-aluminum and E-glass/epoxy composite-to-aluminum tubular lap joints under axial load has been conducted. Test results include strength and failure mode data. Moreover, strain gages placed along the length of the outer tubular adherend characterize load transfer from one adherend to the other. The strain gage data indicate that load transfer is nonuniform and that the relatively compliant PMMA has the shorter load transfer length. Strains determined by a finite element analysis of the tested joints are in excellent agreement with those measured. Calculated bond stresses are highest in the region of observed failure, and extensive bond yielding is predicted in the E- glass/epoxy composite-to-aluminum joint prior to joint failure. 4 refs., 13 figs., 1 tab.

  10. Flaw Tolerance In Lap Shear Brazed Joints. Part 2

    NASA Technical Reports Server (NTRS)

    Wang, Len; Flom, Yury

    2003-01-01

    This paper presents results of the second part of an on-going effort to gain better understanding of defect tolerance in braze joints. In the first part of this three-part series, we mechanically tested and modeled the strength of the lap joints as a function of the overlap distance. A failure criterion was established based on the zone damage theory, which predicts the dependence of the lap joint shear strength on the overlap distance, based on the critical size of a finite damage zone or an overloaded region in the joint. In this second part of the study, we experimentally verified the applicability of the damage zone criterion on prediction of the shear strength of the lap joint and introduced controlled flaws into the lap joints. The purpose of the study was to evaluate the lap joint strength as a function of flaw size and its location through mechanical testing and nonlinear finite element analysis (FEA) employing damage zone criterion for definition of failure. The results obtained from the second part of the investigation confirmed that the failure of the ductile lap shear brazed joints occurs when the damage zone reaches approximately 10% of the overlap width. The same failure criterion was applicable to the lap joints containing flaws.

  11. Six bioabsorbable polymers: in vitro acute toxicity of accumulated degradation products.

    PubMed

    Taylor, M S; Daniels, A U; Andriano, K P; Heller, J

    1994-01-01

    Bioabsorbable polymer implants may provide a viable alternative to metal implants for internal fracture fixation. One of the potential difficulties with absorbable implants is the possible toxicity of the polymeric degradation products especially if they accumulate and become concentrated. Accordingly, material evaluation must involve dose-response toxicity data as well as mechanical properties and degradation rates. In this study the toxicity and rates of degradation for six polymers were determined, along with the toxicity of their degradation product components. The polymers studied were poly(glycolic acid) (PGA), two samples of poly(L-lactic acid) (PLA) having different molecular weights, poly(ortho ester) (POE), poly(epsilon-caprolactone) (PCL), and poly(hydroxy butyrate valerate) (5% valerate) (PHBV). Polymeric specimens were incubated at 37 degrees C in 0.05 M Tris buffer (pH 7.4 at 37 degrees C) and sterile deionized water. The solutions were not changed during the incubation intervals, providing a worst-case model of the effects of accumulation of degradation products. The pH and acute toxicity of the incubation solutions and the mass loss and logarithmic viscosity number of the polymer samples were measured at 10 days, 4, 8, 12, and 16 weeks. Toxicity was measured using a bioluminescent bacteria, acute toxicity assay system. The acute toxicity of pure PGA, PLA, POE, and PCL degradation product components was also determined. Degradation products for PHBV were not tested. PGA incubation solutions were toxic at 10 days and at all following intervals. The lower molecular weight PLA incubation solutions were not toxic in buffer but were toxic by 4 weeks in water.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:10147175

  12. Net methylmercury production in 2 contrasting stream sediments and associated accumulation and toxicity to periphyton.

    PubMed

    Klaus, Jaclyn E; Hammerschmidt, Chad R; Costello, David M; Burton, G Allen

    2016-07-01

    Periphyton uptake of bioaccumulative methylmercury (MeHg) may be an important entryway into the food web of many stream ecosystems where periphyton can be dominant primary producers. The net production of MeHg in stream sediment, its bioaccumulation in periphyton, and the potential toxicity of divalent Hg (Hg[II]) and MeHg in sediment to periphyton were investigated with a 67-d in situ incubation experiment using chemical exposure substrates containing either a fine-grained, organic-rich or a sandy, low-organic sediment, each amended with varying concentrations of mercuric chloride. Methylmercury was produced in sediment, and concentrations increased with greater amounts of added Hg(II); however, the net production of MeHg was inhibited in the highest Hg(II) treatments of both sediments. The range of total Hg concentrations that inhibited MeHg production was between approximately 80 000 ng Hg and 350 000 ng Hg per gram of organic matter for both sediments. Periphyton colonizing substrates accumulated MeHg in proportion to the concentration in sediment, but periphyton exposed to the sandy sediment accumulated approximately 20-fold more than those exposed to the organic-rich sediment relative to sediment MeHg concentrations. Toxicity of either Hg(II) or MeHg to periphyton was not observed with either periphyton organic content, net primary production, or respiration as endpoints. These results suggest that in situ production and bioaccumulation of MeHg in stream ecosystems can vary as a function of sediment characteristics and Hg(II) loadings to the sediment. Environ Toxicol Chem 2016;35:1759-1765. © 2015 SETAC. PMID:26636557

  13. Effects of agriculture production systems on nitrate and nitrite accumulation on baby-leaf salads

    PubMed Central

    Aires, Alfredo; Carvalho, Rosa; Rosa, Eduardo A S; Saavedra, Maria J

    2013-01-01

    Nitrate and nitrite are widespread contaminants of vegetables, fruits, and waters. The levels of these compounds are increased as a result of using organic wastes from chemical industries, domestic wastes, effluents, nitrogenous fertilizers, and herbicides in agriculture. Therefore, determining the nitrate and nitrite levels in biological, food, and environmental samples is important to protect human health and the environment. In this context, we set this study, in which we report the effect of production system (conventional and organic) on the accumulation of nitrates and nitrites in fresh baby-leaf samples. The average levels of the nitrate () and nitrite () contents in six different baby-leaf salads of a single species (green lettuce, red lettuce, watercress, rucola, chard, and corn salad) produced in organic and conventional agriculture system were evaluated. Spectrophotometric analytical method recently published was validated and used. Nitrates and nitrites were detected in all samples. The nitrates levels from organic production varied between 1.45 and 6.40 mg/kg fresh weight (FW), whereas those from conventional production ranged from 10.5 to 45.19 mg/kg FW. The nitrites content was lower than nitrates and ranged from 0.32 to 1.89 mg/kg FW in organic production system and between 0.14 and 1.41 mg/kg FW in conventional production system. Our results showed that the nitrate content was dependent on the agricultural production system, while for nitrites, this dependency was less pronounced. PMID:24804008

  14. BAFF regulates T follicular helper cells and affects accumulation and IFNγ production in autoimmunity

    PubMed Central

    Coquery, Christine M.; Loo, William M.; Wade, Nekeithia S.; Bederman, Annelise G.; Tung, Kenneth S.; Lewis, Janet E.; Hess, Henry; Erickson, Loren D.

    2014-01-01

    Objective T follicular helper (TFH) cells are critical for the development of protective antibodies via germinal center (GC) B-cell responses; however, uncontrolled TFH cell expansion activates autoreactive B-cells to produce antibodies that cause autoimmunity. The mechanisms that control TFH cell homeostasis remains largely unknown. The aim of this study was to determine the contribution of BAFF to TFH cell responses in autoimmunity. Methods We analyzed the properties of TFH cells in lupus-prone mice, sufficient or deficient in B-cell maturation antigen (BCMA). Adoptive transfer studies and mixed bone marrow chimeras were used to test BCMA signaling in T cells. We assessed BAFF stimulation of TFH cells through in vitro cell cocultures and in vivo depletion studies using flow cytometry. Results In Nba2 mice, TFH cells expressed the BAFF receptors BCMA and BR3, and accumulated in the spleen when BCMA was absent. BCMA deficiency in T cells promoted the expansion of TFH cells, GC formation, autoantibody production, and IFNγ production by TFH cells through BR3. IFNγ-producing TFH cells increased BAFF expression in dendritic cells. Blocking BAFF or IFNγ in vivo reduced TFH cell accumulation and improved autoimmunity in BCMA-deficient animals. Moreover, circulating TFH-like cells that expressed BR3 (but not BCMA) were elevated in SLE patients, which correlated with serum BAFF and IFNγ titers. Conclusion In Nba2 mice, BCMA negatively regulates TFH cell expansion whereas BAFF signaling through BR3 promotes TFH cell accumulation. Our work suggests the balance between BCMA and BR3 signaling in TFH cells serves as a checkpoint of immune tolerance. PMID:25385309

  15. Rate of production, dissolution and accumulation of biogenic solids in the ocean

    NASA Technical Reports Server (NTRS)

    Arrhenius, G.

    1988-01-01

    The equatorial current system, by its response to global circulation changes, provides a unique recording mechanism for long range climatic oscillations. A permanent record of the changes in rate of upwelling and organic production is generated in the equatorial deep sea sediments, particularly by such biogenic components which are unaffected by secondary dissolution. In order to determine the rates of accumulation of various sedimentary components, a reliable differential measurement of age of the strata must be obtained. Various approaches to this problem are reviewed, and sources of error discussed. Secondary dissolution of calcium carbonate introduces a substantial and variable difference between the dissolution-modified, and hence a priori unknown, rate of deposition on one hand and the rate of accumulation, derivable from the observed concentration, on the other. The cause and magnitude of these variations are of importance, particularly since some current dating schemes are based on assumed constancy in the rate of accumulation of this and, in some cases, also all other sedimentary components. The concepts used in rate evaluation are discussed with emphasis on the difference between the state of dissolution, an observable property of the sediment, and the rate of dissolution, a parameter that requires deduction of the carbonate fraction dissolved, and of the time differential. As a most likely cause of the enhanced state of dissolution of the interglacial carbonate sediments is proposed the lowered rates of biogenic production and deposition, which cause longer exposure of the carbonate microfossils to corrosion in the bioturbated surface layer of the sediment. Historical perspective is included in the discussion in view of the dedication of the Symposium to Hans Pettersson, the leader of the Swedish Deep Sea Expedition 1947-1948, an undertaking that opened a new era in deep sea research and planetary dynamics.

  16. Genetic analysis on accumulated productivity and calving intervals in Nelore cattle.

    PubMed

    Grossi, Daniela do Amaral; Berton, Mariana Piatto; Buzanskas, Marcos Eli; Chud, Tatiane Cristina Seleguim; Grupioni, Natália Vinhal; de Paz, Claudia Cristina Paro; Lôbo, Raysildo Barbosa; Munari, Danísio Prado

    2016-01-01

    The aim of this study was to estimate genetic parameters for accumulated productivity (ACP), first calving interval (CI1), second calving interval (CI2), and mean calving interval (MCI) in Nelore beef cattle. The ACP trait is a reproduction index and comprises the total number of calves born per dam, weight of weaned calves, and age of the dam at calving. Genetic parameters were estimated by the average information restricted maximum likelihood method in two-trait analyses. The average heritability estimate for ACP was 0.17 (0.03). For CI1, CI2, and MCI, the heritability estimates were 0.02, 0.02, and 0.06, respectively. Genetic correlations between ACP with CI1, CI2, and MCI were -0.16 ± 0.47, -0.29 ± 0.53, and -0.40 ± 0.27, respectively. Despite of the low heritability estimates obtained in our study, reproduction traits should be further studied and their inclusion in the selection criteria must be evaluated in order to improve the performance of females because these traits are of great economic importance in beef cattle. Accumulated productivity could contribute to decrease the mean calving interval in Nelore cattle. PMID:26387093

  17. New mathematical model for error reduction of stressed lap

    NASA Astrophysics Data System (ADS)

    Zhao, Pu; Yang, Shuming; Sun, Lin; Shi, Xinyu; Liu, Tao; Jiang, Zhuangde

    2016-05-01

    Stressed lap, compared to traditional polishing methods, has high processing efficiency. However, this method has disadvantages in processing nonsymmetric surface errors. A basic-function method is proposed to calculate parameters for a stressed-lap polishing system. It aims to minimize residual errors and is based on a matrix and nonlinear optimization algorithm. The results show that residual root-mean-square could be >15% after one process for classical trefoil error. The surface period errors close to the lap diameter were removed efficiently, up to 50% material removal.

  18. Machine Shop I. Learning Activity Packets (LAPs). Section A--Orientation.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains two learning activity packets (LAPs) for the "orientation and safety" instructional area of a Machine Shop I course. The two LAPs cover the following topics: orientation and general shop safety. Each LAP contains a cover sheet that describes its purpose, an introduction, and the tasks included in the LAP; learning steps…

  19. Machine Shop I. Learning Activity Packets (LAPs). Section C--Hand and Bench Work.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains two learning activity packets (LAPs) for the "hand and bench work" instructional area of a Machine Shop I course. The two LAPs cover the following topics: hand and bench work and pedestal grinder. Each LAP contains a cover sheet that describes its purpose, an introduction, and the tasks included in the LAP; learning steps…

  20. Machine Shop I. Learning Activity Packets (LAPs). Section D--Power Saws and Drilling Machines.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains two learning activity packets (LAPs) for the "power saws and drilling machines" instructional area of a Machine Shop I course. The two LAPs cover the following topics: power saws and drill press. Each LAP contains a cover sheet that describes its purpose, an introduction, and the tasks included in the LAP; learning steps…

  1. Multifrequency Eddy Current Inspection of Corrosion in Clad Aluminum Riveted Lap Joints and Its Effect on Fatigue Life

    SciTech Connect

    Okafor, A. C.; Natarajan, S.

    2007-03-21

    Aging aircraft are prone to corrosion damage and fatigue cracks in riveted lap joints of fuselage skin panels. This can cause catastrophic failure if not detected and repaired. Hence detection of corrosion damage and monitoring its effect on structural integrity are essential. This paper presents multifrequency eddy current (EC) inspection of corrosion damage and machined material loss defect in clad A1 2024-T3 riveted lap joints and its effect on fatigue life. Results of eddy current inspection, corrosion product removal and fatigue testing are presented.

  2. Multifrequency Eddy Current Inspection of Corrosion in Clad Aluminum Riveted Lap Joints and Its Effect on Fatigue Life

    NASA Astrophysics Data System (ADS)

    Okafor, A. C.; Natarajan, S.

    2007-03-01

    Aging aircraft are prone to corrosion damage and fatigue cracks in riveted lap joints of fuselage skin panels. This can cause catastrophic failure if not detected and repaired. Hence detection of corrosion damage and monitoring its effect on structural integrity are essential. This paper presents multifrequency eddy current (EC) inspection of corrosion damage and machined material loss defect in clad A1 2024-T3 riveted lap joints and its effect on fatigue life. Results of eddy current inspection, corrosion product removal and fatigue testing are presented.

  3. INTERIOR OF WEST SPAN LOOKING WEST (SHADOW OF VERTICAL LAPS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR OF WEST SPAN LOOKING WEST (SHADOW OF VERTICAL LAPS PLACED ON ZONE III; ASPHALT ZONE IX) - Honey Run Bridge, Spanning Butte Creek, bypassed section of Honey Run Road (originally Carr Hill Road), Paradise, Butte County, CA

  4. FRICTION STIR LAP WELDING OF ALUMINUM - POLYMER USING SCRIBE TECHNOLOGY

    SciTech Connect

    Upadhyay, Piyush; Hovanski, Yuri; Fifield, Leonard S.; Simmons, Kevin L.

    2015-02-16

    Friction Stir Scribe (FSS) technology is a relatively new variant of Friction Stir Welding (FSW) which enables lap joining of dissimilar material with very different melting points and different high temperature flow behaviors. The cutter scribe attached at the tip of FSW tool pin effectively cuts the high melting point material such that a mechanically interlocking feature is created between the dissimilar materials. The geometric shape of this interlocking feature determines the shear strength attained by the lap joint. This work presents first use of scribe technology in joining polymers to aluminum alloy. Details of the several runs of scribe welding performed in lap joining of ~3.175mm thick polymers including HDPE, filled and unfilled Nylon 66 to 2mm thick AA5182 are presented. The effect of scribe geometry and length on weld interlocking features is presented along with lap shear strength evaluations.

  5. [Dipeptide nootropic agent GVS-111 prevents accumulation of the lipid peroxidation products during immobilization].

    PubMed

    Lysenko, A V; Uskova, N I; Ostrovskaia, R U; Gudasheva, T A; Voronina, T A

    1997-01-01

    Immobilization of rats in a narrow plastic chamber for 24 h caused a sharp increase in the level of diene conjugates and the content of schiff bases in the synaptosomes of the brain cortex as well as accumulation of extraerythrocytic hemoglobin in blood serum. The dipeptide nootropic agent GVS-111 (ethyl ether of phenylacetylprolylglycine), when administered 15 and particularly 60 min before immobilization reduced the accumulation of these products of lipid peroxidation in the brain and blood. GVS-111 demonstrated these signs of its antioxidant effect after a single i.p. injection in doses of 0.12 and 0.5 mg/kg. Pyracetam produced a similar effect on the listed parameters in injection in a dose of 300 mg/kg for three successive days. The protective effect of the new pyracetam dipeptide analog GVS-111 in relation to activation of free-radical processes induced by immobilization is additional proof of the antistress action of this dipeptide. PMID:9483398

  6. Does Accumulation of Advanced Glycation End Products Contribute to the Aging Phenotype?

    PubMed Central

    Nicklett, Emily J.; Ferrucci, Luigi

    2010-01-01

    Background. Aging is a complex multifactorial process characterized by accumulation of deleterious changes in cells and tissues, progressive deterioration of structural integrity and physiological function across multiple organ systems, and increased risk of death. Methods. We conducted a review of the scientific literature on the relationship of advanced glycation end products (AGEs) with aging. AGEs are a heterogeneous group of bioactive molecules that are formed by the nonenzymatic glycation of proteins, lipids, and nucleic acids. Results. Humans are exposed to AGEs produced in the body, especially in individuals with abnormal glucose metabolism, and AGEs ingested in foods. AGEs cause widespread damage to tissues through upregulation of inflammation and cross-linking of collagen and other proteins. AGEs have been shown to adversely affect virtually all cells, tissues, and organ systems. Recent epidemiological studies demonstrate that elevated circulating AGEs are associated with increased risk of developing many chronic diseases that disproportionally affect older individuals. Conclusions. Based on these data, we propose that accumulation of AGEs accelerate the multisystem functional decline that occurs with aging, and therefore contribute to the aging phenotype. Exposure to AGEs can be reduced by restriction of dietary intake of AGEs and drug treatment with AGE inhibitors and AGE breakers. Modification of intake and circulating levels of AGEs may be a possible strategy to promote health in old age, especially because most Western foods are processed at high temperature and are rich in AGEs. PMID:20478906

  7. Effects of agriculture production systems on nitrate and nitrite accumulation on baby-leaf salads.

    PubMed

    Aires, Alfredo; Carvalho, Rosa; Rosa, Eduardo A S; Saavedra, Maria J

    2013-01-01

    Nitrate and nitrite are widespread contaminants of vegetables, fruits, and waters. The levels of these compounds are increased as a result of using organic wastes from chemical industries, domestic wastes, effluents, nitrogenous fertilizers, and herbicides in agriculture. Therefore, determining the nitrate and nitrite levels in biological, food, and environmental samples is important to protect human health and the environment. In this context, we set this study, in which we report the effect of production system (conventional and organic) on the accumulation of nitrates and nitrites in fresh baby-leaf samples. The average levels of the nitrate ([Formula: see text]) and nitrite ([Formula: see text]) contents in six different baby-leaf salads of a single species (green lettuce, red lettuce, watercress, rucola, chard, and corn salad) produced in organic and conventional agriculture system were evaluated. Spectrophotometric analytical method recently published was validated and used. Nitrates and nitrites were detected in all samples. The nitrates levels from organic production varied between 1.45 and 6.40 mg/kg fresh weight (FW), whereas those from conventional production ranged from 10.5 to 45.19 mg/kg FW. The nitrites content was lower than nitrates and ranged from 0.32 to 1.89 mg/kg FW in organic production system and between 0.14 and 1.41 mg/kg FW in conventional production system. Our results showed that the nitrate content was dependent on the agricultural production system, while for nitrites, this dependency was less pronounced. PMID:24804008

  8. Adhesive-bonded scarf and stepped-lap joints

    NASA Technical Reports Server (NTRS)

    Hart-Smith, L. J.

    1973-01-01

    Continuum mechanics solutions are derived for the static load-carrying capacity of scarf and stepped-lap adhesive-bonded joints. The analyses account for adhesive plasticity and adherend stiffness imbalance and thermal mismatch. The scarf joint solutions include a simple algebraic formula which serves as a close lower bound, within a small fraction of a per cent of the true answer for most practical geometries and materials. Digital computer programs were developed and, for the stepped-lap joints, the critical adherend and adhesive stresses are computed for each step. The scarf joint solutions exhibit grossly different behavior from that for double-lap joints for long overlaps inasmuch as that the potential bond shear strength continues to increase with indefinitely long overlaps on the scarf joints. The stepped-lap joint solutions exhibit some characteristics of both the scarf and double-lap joints. The stepped-lap computer program handles arbitrary (different) step lengths and thickness and the solutions obtained have clarified potentially weak design details and the remedies. The program has been used effectively to optimize the joint proportions.

  9. Denitrifying Bacterial Communities Affect Current Production and Nitrous Oxide Accumulation in a Microbial Fuel Cell

    PubMed Central

    Vilar-Sanz, Ariadna; Puig, Sebastià; García-Lledó, Arantzazu; Trias, Rosalia; Balaguer, M. Dolors; Colprim, Jesús; Bañeras, Lluís

    2013-01-01

    The biocathodic reduction of nitrate in Microbial Fuel Cells (MFCs) is an alternative to remove nitrogen in low carbon to nitrogen wastewater and relies entirely on microbial activity. In this paper the community composition of denitrifiers in the cathode of a MFC is analysed in relation to added electron acceptors (nitrate and nitrite) and organic matter in the cathode. Nitrate reducers and nitrite reducers were highly affected by the operational conditions and displayed high diversity. The number of retrieved species-level Operational Taxonomic Units (OTUs) for narG, napA, nirS and nirK genes was 11, 10, 31 and 22, respectively. In contrast, nitrous oxide reducers remained virtually unchanged at all conditions. About 90% of the retrieved nosZ sequences grouped in a single OTU with a high similarity with Oligotropha carboxidovorans nosZ gene. nirS-containing denitrifiers were dominant at all conditions and accounted for a significant amount of the total bacterial density. Current production decreased from 15.0 A·m−3 NCC (Net Cathodic Compartment), when nitrate was used as an electron acceptor, to 14.1 A·m−3 NCC in the case of nitrite. Contrarily, nitrous oxide (N2O) accumulation in the MFC was higher when nitrite was used as the main electron acceptor and accounted for 70% of gaseous nitrogen. Relative abundance of nitrite to nitrous oxide reducers, calculated as (qnirS+qnirK)/qnosZ, correlated positively with N2O emissions. Collectively, data indicate that bacteria catalysing the initial denitrification steps in a MFC are highly influenced by main electron acceptors and have a major influence on current production and N2O accumulation. PMID:23717427

  10. Highly accumulative production of L(+)-lactate from glucose by crystallization fermentation with immobilized Rhizopus oryzae.

    PubMed

    Yamane, Tsuneo; Tanaka, Ryohsuke

    2013-01-01

    In order to produce microbiologically large amount of l(+)-lactic acid (LA) from glucose, batch and fed-batch (intermittent addition of sterilized glucose powder aseptically) cultures of Rhizopus oryzae NBRC 5384 (identical to NRRL 395 and ATCC 9363) whose mycelia were immobilized in situ within sponge-like cubic particles (3.5 mm edge long) were carried out at 37°C in a three baffled shake flask. Appropriately calculated amount of fine powdery calcium carbonate (CaCO(3)) was added initially or intermittently to control pH of the culture liquids. High accumulations of LA (145 g/L and 231 g/L, in reality 176 g/L and 280 g/L as anhydrous calcium lactate) were achieved by a batch (glucose concentration = 150 g/L) and a fed-batch cultures (the initial glucose concentration = 150 g/L and the intermittent addition of glucose equivalent to 100 g/L). In these cultures the yields and productivities of LA were, 95.0%, 1.42 g/L·h and 92.5%, 1.83 g/L·h, respectively. Existence of considerable amounts of calcium lactate (Ca(LA)(2)) as crystals in the culture broth was experimentally proved by two evidences: (i) heating up (70°C) followed by quick low centrifugal force to remove remaining CaCO(3) solids from culture broth and then cooling down (37°C) followed by incubation of the culture supernatant at 37°C to observe recrystallization of Ca(LA)(2), and (ii) the measurement of solubility of Ca(LA)(2) in the culture media. It was conceptually discussed to be able to avoid the product inhibition by means of crystallization fermentation for the high accumulation of LA by R. oryzae. PMID:22938823

  11. Denitrifying bacterial communities affect current production and nitrous oxide accumulation in a microbial fuel cell.

    PubMed

    Vilar-Sanz, Ariadna; Puig, Sebastià; García-Lledó, Arantzazu; Trias, Rosalia; Balaguer, M Dolors; Colprim, Jesús; Bañeras, Lluís

    2013-01-01

    The biocathodic reduction of nitrate in Microbial Fuel Cells (MFCs) is an alternative to remove nitrogen in low carbon to nitrogen wastewater and relies entirely on microbial activity. In this paper the community composition of denitrifiers in the cathode of a MFC is analysed in relation to added electron acceptors (nitrate and nitrite) and organic matter in the cathode. Nitrate reducers and nitrite reducers were highly affected by the operational conditions and displayed high diversity. The number of retrieved species-level Operational Taxonomic Units (OTUs) for narG, napA, nirS and nirK genes was 11, 10, 31 and 22, respectively. In contrast, nitrous oxide reducers remained virtually unchanged at all conditions. About 90% of the retrieved nosZ sequences grouped in a single OTU with a high similarity with Oligotropha carboxidovorans nosZ gene. nirS-containing denitrifiers were dominant at all conditions and accounted for a significant amount of the total bacterial density. Current production decreased from 15.0 A · m(-3) NCC (Net Cathodic Compartment), when nitrate was used as an electron acceptor, to 14.1 A · m(-3) NCC in the case of nitrite. Contrarily, nitrous oxide (N2O) accumulation in the MFC was higher when nitrite was used as the main electron acceptor and accounted for 70% of gaseous nitrogen. Relative abundance of nitrite to nitrous oxide reducers, calculated as (qnirS+qnirK)/qnosZ, correlated positively with N2O emissions. Collectively, data indicate that bacteria catalysing the initial denitrification steps in a MFC are highly influenced by main electron acceptors and have a major influence on current production and N2O accumulation. PMID:23717427

  12. Continuous Influenza Virus Production in Cell Culture Shows a Periodic Accumulation of Defective Interfering Particles

    PubMed Central

    Pflugmacher, Antje; Behrendt, Ilona; Jordan, Ingo; Flockerzi, Dietrich; Genzel, Yvonne; Reichl, Udo

    2013-01-01

    Influenza viruses are a major public health burden during seasonal epidemics and a continuous threat due to their potential to cause pandemics. Annual vaccination provides the best protection against the contagious respiratory illness caused by influenza viruses. However, the current production capacities for influenza vaccines are insufficient to meet the increasing demands. We explored the possibility to establish a continuous production process for influenza viruses using the duck-derived suspension cell line AGE1.CR. A two-stage bioreactor setup was designed in which cells were cultivated in a first stirred tank reactor where an almost constant cell concentration was maintained. Cells were then constantly fed to a second bioreactor where virus infection and replication took place. Using this two-stage reactor system, it was possible to continuously produce influenza viruses. Surprisingly, virus titers showed a periodic increase and decrease during the run-time of 17 days. These titer fluctuations were caused by the presence of defective interfering particles (DIPs), which we detected by PCR. Mathematical modeling confirmed this observation showing that constant virus titers can only emerge in the absence of DIPs. Even with very low amounts of DIPs in the seed virus and very low rates for de novo DIP generation, defective viruses rapidly accumulate and, therefore, represent a serious challenge for continuous vaccine production. Yet, the continuous replication of influenza virus using a two-stage bioreactor setup is a novel tool to study aspects of viral evolution and the impact of DIPs. PMID:24039749

  13. Tolerance and accumulation of lead in Vetiveria zizanioides and its effect on oil production.

    PubMed

    Rotkittikhun, P; Kruatrachue, M; Pokethitiyook, P; Baker, A J M

    2010-05-01

    Experiments were conducted to evaluate lead tolerance and accumulation in vetiver grass Vetiveria zizanioides (L.), grown in hydroponics and a pot study and to examine the effect of lead on vetiver oil production. Elevated concentrations of lead decreased the length of shoots and roots of plants. However, vetiver grown in highly contaminated soils showed no apparent phytotoxicity symptoms. Lead concentrations in the shoots and roots of vetiver plants grown in hydroponics were up to 144 and 19530 mg kg(-1) and those grown in soil were 38 and 629 mg kg(-1), respectively. Lead had an effect on vetiver oil production and composition by stimulating oil yield and the number of its constituents. Oil yield ranged from 0.4-1.3%; the highest yields were found in plants grown in nutrient solution with 100 mg Pb l(-1) for 5 weeks (1.29%) and 7 weeks (1.22%). The number of total constituents of vetiver oil also varied between 47-143 compounds when lead was presentin the growth medium. The highest number (143) was found in plants grown in soil spiked with 1000 mg Pb kg(-1). The predominant compound was khusimol (10.7-18.1%) followed by (E)-isovalencenol (10.3-15.6%). Our results indicated that lead could increase the oil production of vetiver. PMID:21047007

  14. Spider dragline silk proteins in transgenic tobacco leaves: accumulation and field production.

    PubMed

    Menassa, Rima; Zhu, Hong; Karatzas, Costas N; Lazaris, Anthoula; Richman, Alex; Brandle, Jim

    2004-09-01

    Spider dragline silk is a unique biomaterial and represents nature's strongest known fibre. As it is almost as strong as many commercial synthetic fibres, it is suitable for use in many industrial and medical applications. The prerequisite for such a widespread use is the cost-effective production in sufficient quantities for commercial fibre manufacturing. Agricultural biotechnology and the production of recombinant dragline silk proteins in transgenic plants offer the potential for low-cost, large-scale production. The purpose of this work was to examine the feasibility of producing the two protein components of dragline silk (MaSp1 and MaSp2) from Nephila clavipes in transgenic tobacco. Two different promoters, the enhanced CaMV 35S promoter (Kay et al., 1987) and a new tobacco cryptic constitutive promoter, tCUP (Foster et al., 1999) were used, in conjunction with a plant secretory signal (PR1b), a translational enhancer (alfalfa mosaic virus, AMV) and an endoplasmic reticulum (ER) retention signal (KDEL), to express the MaSp1 and MaSp2 genes in the leaves of transgenic plants. Both genes expressed successfully and recombinant protein accumulated in transgenic plants grown in both greenhouse and field trials. PMID:17168889

  15. Chemical Pollutants Sorbed to Ingested Microbeads from Personal Care Products Accumulate in Fish.

    PubMed

    Wardrop, Peter; Shimeta, Jeff; Nugegoda, Dayanthi; Morrison, Paul D; Miranda, Ana; Tang, Min; Clarke, Bradley O

    2016-04-01

    The prevalence of microplastics (<5 mm) in natural environments has become a widely recognized global problem. Microplastics have been shown to sorb chemical pollutants from their surrounding environment, thus raising concern as to their role in the movement of these pollutants through the food chain. This experiment investigated whether organic pollutants sorbed to microbeads (MBs) from personal care products were assimilated by fish following particle ingestion. Rainbow fish (Melanotaenia fluviatilis) were exposed to MBs with sorbed polybrominated diphenyl ethers (PBDEs; BDE-28, -47, -100, -99, -153, -154, -183, 200 ng g(-1); BDE-209, 2000 ng g(-1)) and sampled at 0, 21, 42, and 63 days along with two control treatments (food only and food + clean MBs). Exposed fish had significantly higher Σ8PBDE concentrations than both control treatments after just 21 days, and continued exposure resulted in increased accumulation of the pollutants over the experiment (ca. 115 pg g(-1) ww d(-1)). Lower brominated congeners showed the highest assimilation whereas higher brominated congeners did not appear to transfer, indicating they may be too strongly sorbed to the plastic or unable to be assimilated by the fish due to large molecular size or other factors. Seemingly against this trend, however, BDE-99 did not appear to bioaccumulate in the fish, which may be due to partitioning from the MBs or it being metabolized in vivo. This work provides evidence that MBs from personal care products are capable of transferring sorbed pollutants to fish that ingest them. PMID:26963589

  16. Epicatechin breaks preformed glycated serum albumin and reverses the retinal accumulation of advanced glycation end products.

    PubMed

    Kim, Junghyun; Kim, Chan-Sik; Moon, Min Kyong; Kim, Jin Sook

    2015-02-01

    The accumulation of advanced glycation end products (AGEs) is associated with many of the complications of diabetes mellitus, including diabetic retinopathy. AGE-breakers, such as N-phenacylthiazolium and alagebrium, have been proposed as therapeutic agents for reversing the increase in protein crosslinking in diabetes. (-)-Epicatechin is a major dietary flavonoid with a wide range of health-promoting biological activities. The aim of this study was to determine the potential effect of (-)-epicatechin in reducing the burden of AGEs in vitro and in vivo and to evaluate whether the reduced AGE burden could translate into improvement in retinal vascular function in exogenously AGE-injected rats. Glycated human serum albumin was purified from patients with diabetes. The breakdown of the already formed AGEs was studied by treating glycated human serum albumin with (-)-epicatechin. To study the effect of (-)-epicatechin on retinal vascular function, exogenously AGE-injected rats were treated with (-)-epicatechin (50 and 100 mg/kg i.p.) for two weeks. Apoptosis of retinal vascular cells was quantified using TUNEL staining. The AGE load in the retinas was determined via immunohistochemical staining and western blot analysis. (-)-Epicatechin was able to break preformed glycated human serum albumin in vitro as well as reduce AGE accumulation in retinas in vivo in a dose dependent manner. In exogenously AGE-injected rats, treatment with (-)-epicatechin was evidenced by an improved retinal vascular apoptosis. AGE burden in retinas was also reduced upon treatment. This study suggests that (-)-epicatechin could represent a valuable drug for the treatment of diabetic retinopathy by reducing the AGE burden. PMID:25530268

  17. Flaw Tolerance in Lap Shear Brazed Joints. Part 1

    NASA Technical Reports Server (NTRS)

    Flom, Yury; Wang, Li-Qin

    2003-01-01

    Furnace brazing is a joining process used in the aerospace and other industries to produce strong permanent and hermetic structural joints. As in any joining process, brazed joints have various imperfections and defects. At the present time, our understanding of the influence of the internal defects on the strength of the brazed joints is not adequate. The goal of this 3-part investigation is to better understand the properties and failure mechanisms of the brazed joints containing defects. This study focuses on the behavior of the brazed lap shear joints because of their importance in manufacturing aerospace structures. In Part 1, an average shear strength capability and failure modes of the single lap joints are explored. Stainless steel specimens brazed with pure silver are tested in accordance with the AWS C3.2 standard. Comparison of the failure loads and the ultimate shear strength with the Finite Element Analysis (FEA) of the same specimens as a function of the overlap widths shows excellent correlation between the experimental and calculated values for the defect-free lap joints. A damage zone criterion is shown to work quite well in understanding the failure of the braze joints. In Part 2, the findings of the Part 1 will be verified on the larger test specimens. Also, various flaws will be introduced in the test specimens to simulate lack of braze coverage in the lap joints. Mechanical testing and FEA will be performed on these joints to verify that behavior of the flawed ductile lap joints is similar to joints with a reduced braze area. Finally, in Part 3, the results obtained in Parts 1 and 2 will be applied to the actual brazed structure to evaluate the load-carrying capability of a structural lap joint containing discontinuities. In addition, a simplified engineering procedure will be offered for the laboratory testing of the lap shear specimens.

  18. Use of two-dimensional transmission photoelastic models to study stresses in double-lap bolted joints: Load transfer and stresses in the inner lap

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.

    1980-01-01

    The determination of the stress distribution in the inner lap of double-lap, double-bolt joints using photoelastic models of the joint is discussed. The principal idea is to fabricate the inner lap of a photoelastic material and to use a photoelastically sensitive material for the two outer laps. With this setup, polarized light transmitted through the stressed model responds principally to the stressed inner lap. The model geometry, the procedures for making and testing the model, and test results are described.

  19. Lap time optimisation of a racing go-kart

    NASA Astrophysics Data System (ADS)

    Lot, Roberto; Dal Bianco, Nicola

    2016-02-01

    The minimum lap time optimal control problem has been solved for a go-kart model. The symbolic algebra software Maple has been used to derive equations of motion and an indirect method has been adopted to solve the optimal control problem. Simulation has been successfully performed on a full track lap with a multibody model endowed with seven degrees of freedom. Geometrical and mechanical characteristics of a real kart have been measured by a lab test to feed the mathematical model. Telemetry recorded in an entire lap by a professional driver has been compared to simulation results in order to validate the model. After the reliability of the optimal control model was proved, the simulation has been used to study the peculiar dynamics of go-karts and focus to tyre slippage dynamics, which is highly affected by the lack of differential.

  20. Review on failure prediction techniques of composite single lap joint

    NASA Astrophysics Data System (ADS)

    Ab Ghani A., F.; Rivai, Ahmad

    2016-03-01

    Adhesive bonding is the most appropriate joining method in construction of composite structures. The use of reliable design and prediction technique will produce better performance of bonded joints. Several papers from recent papers and journals have been reviewed and synthesized to understand the current state of the art in this area. It is done by studying the most relevant analytical solutions for composite adherends with start of reviewing the most fundamental ones involving beam/plate theory. It is then extended to review single lap joint non linearity and failure prediction and finally on the failure prediction on composite single lap joint. The review also encompasses the finite element modelling part as tool to predict the elastic response of composite single lap joint and failure prediction numerically.

  1. Novel virtual Lap-Band simulator could promote patient safety.

    PubMed

    De, Suvranu; Ahn, Woojin; Lee, Doo Yong; Jones, Daniel B

    2008-01-01

    This paper presents, for the first time, a physics-based modeling technique for the Lap-Band (Inamed Health) used in laparoscopic gastric banding (LAGB) operations for treating the morbidly obese. A virtual LAGB simulator can help train medical students as well as surgeons who embark at learning this relatively new operation. The Lap-Band has different thickness and curvature along the centerline, and therefore leads to different deformation behaviors. A hybrid modeling strategy is therefore adopted to successfully replicate its dynamics. A mass-spring model, used to model the less stiff part, is coupled to a quasi-static articulated link model for the more stiff and inextensible part. The virtual Lap-Band model has been implemented into a complete graphics-haptics-physics-based system with two PHANToM Omni devices (from Sensible Technologies) being used for real-time bimanual interaction with force feedback. PMID:18391265

  2. Characterization studies on the additives mixed L-arginine phosphate monohydrate (LAP) crystals

    NASA Astrophysics Data System (ADS)

    Haja Hameed, A. S.; Karthikeyan, C.; Ravi, G.; Rohani, S.

    2011-04-01

    L-arginine phosphate monohydrate (LAP), potassium thiocyanate (KSCN) mixed LAP (LAP:KSCN) and sodium sulfite (Na 2SO 3) mixed LAP (LAP:Na 2SO 3) single crystals were grown by slow cooling technique. The effect of microbial contamination and coloration on the growth solutions was studied. The crystalline powders of the grown crystals were examined by X-ray diffraction and the lattice parameters of the crystals were estimated. From the FTIR spectroscopic analysis, various functional group frequencies associated with the crystals were assigned. Vickers microhardness studies were done on {1 0 0} faces for pure and additives mixed LAP crystals. From the preliminary surface second harmonic generation (SHG) results, it was found that the SHG intensity at (1 0 0) face of LAP:KSCN crystal was much stronger than that of pure LAP.

  3. Seam-Tracking for Friction Stir Welded Lap Joints

    NASA Astrophysics Data System (ADS)

    Fleming, Paul A.; Hendricks, Christopher E.; Cook, George E.; Wilkes, D. M.; Strauss, Alvin M.; Lammlein, David H.

    2010-11-01

    This article presents a method for automatic seam-tracking in friction stir welding (FSW) of lap joints. In this method, tracking is accomplished by weaving the FSW tool back-and-forth perpendicular to the direction of travel during welding and monitoring force and torque signals. Research demonstrates the ability of this method to automatically track weld seam positions. Additionally, tensile and S-bend test result comparisons demonstrate that weaving most likely does not reduce weld quality. Finally, benefits of this weave-based method to FSW of lap joints are discussed and methods for incorporating it into existing friction stir welding control algorithms (such as axial load control) are examined.

  4. Effects of bearing surfaces on lap joint energy dissipation

    SciTech Connect

    Kess, H. R.; Rosnow, N. J.; Sidle, B. C.

    2001-01-01

    Energy is dissipated in mechanical systems in several forms. The major contributor to damping in bolted lap joints is friction, and the level of damping is a function of stress distribution in the bearing surfaces. This study examines the effects of bearing surface configuration on lap joint energy dissipation. The examination is carried out through the analysis of experimental results in a nonlinear framework. Then finite element models are constructed in a nonlinear framework to simulate the results. The experimental data were analyzed using piecewise linear log decrement. Phenomenological and non-phenomenological mathematical models were used to simulate joint behavior. Numerical results of experiments and analyses are presented.

  5. 4-hydroxynonenal, a lipid peroxidation product, rapidly accumulates following traumatic spinal cord injury and inhibits glutamate uptake.

    PubMed

    Springer, J E; Azbill, R D; Mark, R J; Begley, J G; Waeg, G; Mattson, M P

    1997-06-01

    Traumatic injury to the spinal cord initiates a host of pathophysiological events that are secondary to the initial insult. One such event is the accumulation of free radicals that damage lipids, proteins, and nucleic acids. A major reactive product formed following lipid peroxidation is the aldehyde, 4-hydroxynonenal (HNE), which cross-links to side chain amino acids and inhibits the function of several key metabolic enzymes. In the present study, we used immunocytochemical and immunoblotting techniques to examine the accumulation of protein-bound HNE, and synaptosomal preparations to study the effects of spinal cord injury and HNE formation on glutamate uptake. Protein-bound HNE increased in content in the damaged spinal cord at early times following injury (1-24 h) and was found to accumulate in myelinated fibers distant to the site of injury. Immunoblots revealed that protein-bound HNE levels increased dramatically over the same postinjury interval. Glutamate uptake in synaptosomal preparations from injured spinal cords was decreased by 65% at 24 h following injury. Treatment of control spinal cord synaptosomes with HNE was found to decrease significantly, in a dose-dependent fashion, glutamate uptake, an effect that was mimicked by inducers of lipid peroxidation. Taken together, these findings demonstrate that the lipid peroxidation product HNE rapidly accumulates in the spinal cord following injury and that a major consequence of HNE accumulation is a decrease in glutamate uptake, which may potentiate neuronal cell dysfunction and death through excitotoxic mechanisms. PMID:9166741

  6. Effects of bicarbonate/lactate solution on peritoneal advanced glycosylation end-product accumulation.

    PubMed

    Park, M S; Kim, J K; Holmes, C; Weiss, M F

    2000-01-01

    Advanced glycosylation end-products (AGEs) are associated with diabetic complications and peritoneal damage after long-term peritoneal dialysis (PD) with high glucose dialysis solutions. Glucose degradation products (GDPs) derived during heat sterilization of high glucose dialysis solutions are thought to accelerate AGE formation. A new technique of separating glucose from electrolytes has yielded markedly lower GDP levels and permitted the use of dialysis solutions containing the physiologic buffer bicarbonate. Formation of AGEs in vitro with this new solution is significantly lower compared with formation of AGEs with conventional solutions. The purpose of the present study was to investigate the effect of long-term intraperitoneal use of new, neutral dialysis solution (B/L) containing bicarbonate (25 mmol/L) and lactate (15 mmol/L) on peritoneal AGE accumulation and permeability. Normal male Sprague-Dawley rats were used. Twice daily for 12 weeks, 30 mL of new solution (B/L) or conventional solution [Lac (lactate 40 mmol/L)] was injected into the peritoneal cavity of the test rats. As a control, rats that were not injected were kept for 12 weeks in the same manner as the test rats. After 12 weeks, a 2-hour peritoneal equilibration test (PET) was performed in the test rats. After the PET, the parietal peritoneum and liver were obtained for evaluation of peritoneal morphology and for immunohistochemistry for AGE. Intensity of AGE staining was semi-quantitatively graded from 0 to 3. The omentum was also obtained and immediately frozen for analysis of pentosidine content by high-performance liquid chromatography. Compared with findings in the control group, hematoxylin and eosin staining of the parietal peritoneum and liver samples revealed partial denudation of mesothelial cells in the Lac group; denudation was not remarkable in the B/L group. The B/L solution showed significantly less AGE staining in the peritoneal cavity compared to conventional solution. However

  7. Auto Mechanics I. Learning Activity Packets (LAPs). Section C--Engine.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains five learning activity packets (LAPs) that outline the study activities for the "engine" instructional area for an Auto Mechanics I course. The five LAPs cover the following topics: basic engine principles, cooling system, engine lubrication system, exhaust system, and fuel system. Each LAP contains a cover sheet that…

  8. Auto Mechanics I. Learning Activity Packets (LAPs). Section B--Measuring.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains three learning activity packets (LAPs) that outline the study activities for the instructional area of measuring for an Auto Mechanics I course. The three LAPs cover the following topics: rules, the outside micrometer, and the inside micrometer. Each LAP contains a cover sheet that describes its purpose, an introduction, and…

  9. Auto Mechanics I. Learning Activity Packets (LAPs). Section D--Suspension.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains six learning activity packets (LAPs) that outline the study activities for the "suspension" instructional area for an Auto Mechanics I course. The six LAPs cover the following topics: wheel bearings, tires and wheels, wheel balancing, suspension system, steering system, and wheel alignment. Each LAP contains a cover sheet…

  10. Transcriptomic Analyses during the Transition from Biomass Production to Lipid Accumulation in the Oleaginous Yeast Yarrowia lipolytica

    PubMed Central

    Beopoulos, Athanasios; Lelandais, Gaëlle; Le Berre, Veronique; Uribelarrea, Jean-Louis; Molina-Jouve, Carole; Nicaud, Jean-Marc

    2011-01-01

    We previously developed a fermentation protocol for lipid accumulation in the oleaginous yeast Y. lipolytica. This process was used to perform transcriptomic time-course analyses to explore gene expression in Y. lipolytica during the transition from biomass production to lipid accumulation. In this experiment, a biomass concentration of 54.6 gCDW/l, with 0.18 g/gCDW lipid was obtained in ca. 32 h, with low citric acid production. A transcriptomic profiling was performed on 11 samples throughout the fermentation. Through statistical analyses, 569 genes were highlighted as differentially expressed at one point during the time course of the experiment. These genes were classified into 9 clusters, according to their expression profiles. The combination of macroscopic and transcriptomic profiles highlighted 4 major steps in the culture: (i) a growth phase, (ii) a transition phase, (iii) an early lipid accumulation phase, characterized by an increase in nitrogen metabolism, together with strong repression of protein production and activity; (iv) a late lipid accumulation phase, characterized by the rerouting of carbon fluxes within cells. This study explores the potential of Y. lipolytica as an alternative oil producer, by identifying, at the transcriptomic level, the genes potentially involved in the metabolism of oleaginous species. PMID:22132183

  11. Patterns of accumulation of miRNAs encoded by herpes simplex virus during productive infection, latency, and on reactivation

    PubMed Central

    Du, Te; Han, Zhiyuan; Zhou, Guoying; Roizman, Bernard

    2015-01-01

    The key events in herpes simplex virus (HSV) infections are (i) replication at a portal of entry into the body modeled by infection of cultured cells; (ii) establishment of a latent state characterized by a sole latency-associated transcript and microRNAs (miRNAs) modeled in murine peripheral ganglia 30 d after inoculation; and (iii) reactivation from the latent state modeled by excision and incubation of ganglia in medium containing anti-NGF antibody for a timespan of a single viral replicative cycle. In this report, we examine the pattern of synthesis and accumulation of 18 HSV-1 miRNAs in the three models. We report the following: (i) H2-3P, H3-3P, H4-3P, H5-3P, H6-3P, and H7-5P accumulated in ganglia harboring latent virus. All but H4-3P were readily detected in productively infected cells, and most likely they originate from three transcriptional units. (ii) H8-5P, H15, H17, H18, H26, and H27 accumulated during reactivation. Of this group, only H26 and H27 could be detected in productively infected cells. (iii) Of the 18 we have examined, only 10 miRNAs were found to accumulate above background levels in productively infected cells. The disparity in the accumulation of miRNAs in cell culture and during reactivation may reflect differences in the patterns of regulation of viral gene expression during productive infection and during reactivation from the latent state. PMID:25535379

  12. Efficient oxidative hydrogen peroxide production and accumulation in photoelectrochemical water splitting using a tungsten trioxide/bismuth vanadate photoanode.

    PubMed

    Fuku, Kojiro; Sayama, Kazuhiro

    2016-04-01

    An aqueous solution of hydrogen carbonate (HCO3(-)) facilitated oxidative hydrogen peroxide (H2O2) production from water on a WO3/BiVO4 photoanode with the simultaneous production of hydrogen (H2) on a Pt cathode even at an applied voltage far lower than the theoretical electrolysis voltage (+1.77 V vs. RHE) under simulated solar light. The unprecedentedly efficient simultaneous production and accumulation of H2O2 and H2 was achieved in 2.0 M KHCO3 at low temperature, and the maximum selectivity, accumulated concentration and turnover number (TON) of H2O2 generated reached ca. 54%, more than 2 mM and 108, respectively. PMID:27009778

  13. Design Document: Content Module; L.A.P. Version I.

    ERIC Educational Resources Information Center

    Porch, Ann; Lang, Pat

    A series of computer programs and routines designed to assist researchers in the analysis of language usage was developed by the Southwest Regional Laboratory (SWRL). This document is one of a series that describes design specifications for the individual modules which comprise the Language Analysis Package (LAP). The Content Module functions as a…

  14. Learning Activity Package, Physical Science 92, LAPs 1-9.

    ERIC Educational Resources Information Center

    Williams, G. J.

    This set of nine teacher-prepared Learning Activity Packages (LAPs) for individualized instruction in physical science covers the topics of scientific equipment and procedures; measure of time, length, area, and volume; water; oxygen and oxidation; atmospheric pressure; motion; machines; carbon; and light and sound. Each unit contains a rationale…

  15. Insights: A LAP on Moles: Teaching an Important Concept.

    ERIC Educational Resources Information Center

    Ihde, John

    1985-01-01

    Describes a learning activity packet (LAP) designed to help students understand the basic concept of the mole as a chemical unit; know relationships between the mole and atomic weights in the periodic table; and solve basic conversion problems involving moles, atoms, and molecules. (JN)

  16. Learning Activity Package, Algebra 124, LAPs 46-55.

    ERIC Educational Resources Information Center

    Holland, Bill

    A series of 10 teacher-prepared Learning Activity Packages (LAPs) in advanced algebra and trigonometry, these units cover absolute value, inequalities, exponents, radicals, and complex numbers; functions; higher degree equations and the derivative; the trigonometric functions; graphs and applications of the trigonometric functions; sequences and…

  17. Nature, origin, and production characteristics of the Lower Silurian regional oil and gas accumulation, central Appalachian basin, United States

    USGS Publications Warehouse

    Ryder, R.; Zagorski, W.A.

    2003-01-01

    uplift and erosion, causing gas leakage and a marked reduction in fluid pressure. Most future natural-gas production in the Clinton/Medina sandstones is anticipated to come from the basin-center accumulation. The Tuscarora Sandstone has additional gas resources but typically low reservoir porosity and permeability, and the likelihood of low-energy (in British thermal units) gas reduce the incentive to explore for it.

  18. [Tropical forest restoration in Costa Rica: the effect of several strategies on litter production, accumulation and decomposition].

    PubMed

    Celentano, Danielle; Zahawi, Rakan A; Finegan, Bryan; Casanoves, Fernando; Ostertag, Rebecca; Cole, Rebecca J; Holl, Karen D

    2011-09-01

    Tropical forest restoration strategies have the potential to accelerate the recovery of the nutrient cycles in degraded lands. Litter production and its decomposition represent the main transfer of organic material and nutrients into the soil substrate. We evaluated litter production, accumulation on the forest floor, and its decomposition under three restoration strategies: plantation (entire area planted with trees), island (trees planted in patches of three different sizes) and control (natural regeneration) plots. We also compared restoration strategies to young secondary forest (7-9 yr). Restoration treatments were established in 50 x 50m plots in June 2004 at six sites in Southern Costa Rica. Planted tree species included two native timber species (Terminalia amazonia and Vochysia guatemalensis) interplanted with two N fixers (Erythrina poeppigiana and Inga edulis). Litter was collected every 15 days between September 2008 and August 2009 in 12 0.25m2 litter traps distributed within each plot; litter that accumulated on the soil surface was collected at four locations (0.25m2 quadrats) within each plot in February and May 2009. Total litter production in plantation (6.3Mg/ha) and secondary forest (7.3Mg/ha) did not differ, but were greater than in islands (3.5Mg/ha) and control (1.4 Mg/ha). Plantation had greatest accumulation of litter on the soil surface (10.6 Mg/ha) as compared to the other treatments (SF = 7.2; I = 6.7; C = 4.9). Secondary forest was the only treatment with a greater annual production of litter than litter accumulation on the soil surface. Carbon storage in litter was similar between plantation and secondary forest, and significantly greater than the other treatments. No differences were found for carbon concentration and storage in the soil among treatments. There was also high variability in the production and accumulation of litter and carbon among sites. Active restoration treatments accelerated the production of litter and carbon

  19. [Migration in soil and accumulation in plants of peaceful nuclear explosion products in Perm region].

    PubMed

    Raskosha, N G; Shuktova, I I

    2015-01-01

    The data on the migration capacity in soil and accumulation of 238Pu, 239, 240Pu, 137Cs and 90Sr by plants in the area of a peaceful nuclear explosion located in the taiga zone are presented. The influence of the soil parameters on the distribution and transformation forms of the radionuclides in the podzolic soil profile was studied. The major amounts of man-made radionuclides were found in the matter of the ground lip. The accumulation parameters of pollutants by plants were the highest for the leaves, young branches and conifer of trees. PMID:25962279

  20. Alternative splicing and co-option of transposable elements: the case of TMPO/LAP2α and ZNF451 in mammals.

    PubMed

    Abascal, Federico; Tress, Michael L; Valencia, Alfonso

    2015-07-15

    Transposable elements constitute a large fraction of vertebrate genomes and, during evolution, may be co-opted for new functions. Exonization of transposable elements inserted within or close to host genes is one possible way to generate new genes, and alternative splicing of the new exons may represent an intermediate step in this process. The genes TMPO and ZNF451 are present in all vertebrate lineages. Although they are not evolutionarily related, mammalian TMPO and ZNF451 do have something in common-they both code for splice isoforms that contain LAP2alpha domains. We found that these LAP2alpha domains have sequence similarity to repetitive sequences in non-mammalian genomes, which are in turn related to the first ORF from a DIRS1-like retrotransposon. This retrotransposon domestication happened separately and resulted in proteins that combine retrotransposon and host protein domains. The alternative splicing of the retrotransposed sequence allowed the production of both the new and the untouched original isoforms, which may have contributed to the success of the colonization process. The LAP2alpha-specific isoform of TMPO (LAP2α) has been co-opted for important roles in the cell, whereas the ZNF451 LAP2alpha isoform is evolving under strong purifying selection but remains uncharacterized. PMID:25735770

  1. Production, accumulation, and decomposition of Melaleuca quinquenervia litter biomass in time and space

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Melaleuca quinquenervia (melaleuca) is highly invasive in various habitats of southern Florida where it has invaded over 200,000 hectares. Some areas have become closed-canopy monocultures with thick layers of leaf litter covering the forest floor. We hypothesized that the dramatic accumulation of...

  2. Using quantum dots to tag subsurface damage in lapped and polished glass samples

    SciTech Connect

    Williams, Wesley B.; Mullany, Brigid A.; Parker, Wesley C.; Moyer, Patrick J.; Randles, Mark H.

    2009-09-20

    Grinding, lapping, and polishing are finishing processes used to achieve critical surface parameters in a variety of precision optical and electronic components. As these processes remove material from the surface through mechanical and chemical interactions, they may induce a damaged layer of cracks, voids, and stressed material below the surface. This subsurface damage (SSD) can degrade the performance of a final product by creating optical aberrations due to diffraction, premature failure in oscillating components, and a reduction in the laser induced damage threshold of high energy optics. As these defects lie beneath the surface, they are difficult to detect, and while many methods are available to detect SSD, they can have notable limitations regarding sample size and type, preparation time, or can be destructive in nature. The authors tested a nondestructive method for assessing SSD that consisted of tagging the abrasive slurries used in lapping and polishing with quantum dots (nano-sized fluorescent particles). Subsequent detection of fluorescence on the processed surface is hypothesized to indicate SSD. Quantum dots that were introduced to glass surfaces during the lapping process were retained through subsequent polishing and cleaning processes. The quantum dots were successfully imaged by both wide field and confocal fluorescence microscopy techniques. The detected fluorescence highlighted features that were not observable with optical or interferometric microscopy. Atomic force microscopy and additional confocal microscope analysis indicate that the dots are firmly embedded in the surface but do not appear to travel deep into fractures beneath the surface. Etching of the samples exhibiting fluorescence confirmed that SSD existed. SSD-free samples exposed to quantum dots did not retain the dots in their surfaces, even when polished in the presence of quantum dots.

  3. Production of polyhydroxyalkanoates from fermented sugar cane molasses by a mixed culture enriched in glycogen accumulating organisms.

    PubMed

    Bengtsson, Simon; Pisco, Ana R; Reis, Maria A M; Lemos, Paulo C

    2010-02-01

    Batch production of polyhydroxyalkanoates (PHAs) under aerobic conditions by an open mixed culture enriched in glycogen accumulating organisms (GAOs) with fermented sugar cane molasses as substrate was studied. The produced polymers contained five types of monomers, namely 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV), 3-hydroxy-2-methylbutyrate (3H2MB), 3-hydroxy-2-methylvalerate (3H2MV) and the medium chain length monomer 3-hydroxyhexanoate (3HHx). With fermented molasses as substrate, PHA was produced under concurrent consumption of stored glycogen with yields of 0.47-0.66 C-mol PHA per C-mol of total carbon substrate and with rates up to 0.65 C-mol/C-molX h. In order to investigate the role of glycogen during aerobic PHA accumulation in GAOs, synthetic single volatile fatty acids (VFAs) were used as substrates and it was found that the fate of glycogen was dependent on the type of VFA being consumed. Aerobic PHA accumulation occurred under concurrent glycogen consumption with acetate as substrate and under minor concurrent glycogen production with propionate as substrate. With butyrate and valerate as substrates, PHA accumulation occurred with the glycogen pool unaffected. The composition of the PHA was dependent on the VFA composition of the fermented molasses and was 56-70 mol-% 3HB, 13-43 mol-% 3HV, 1-23 mol-% 3HHx and 0-2 mol-% 3H2MB and 3H2MV. The high polymer yields and production rates suggest that enrichment of GAOs can be a fruitful strategy for mixed culture production of PHA from waste substrates. PMID:19958801

  4. Enhanced acetyl-CoA production is associated with increased triglyceride accumulation in the green alga Chlorella desiccata

    PubMed Central

    Avidan, Omri; Brandis, Alexander; Rogachev, Ilana; Pick, Uri

    2015-01-01

    Triglycerides (TAGs) from microalgae can be utilized as food supplements and for biodiesel production, but little is known about the regulation of their biosynthesis. This work aimed to test the relationship between acetyl-CoA (Ac-CoA) levels and TAG biosynthesis in green algae under nitrogen deprivation. A novel, highly sensitive liquid chromatography mass spectrometry (LC-MS/MS) technique enabled us to determine the levels of Ac-CoA, malonyl-CoA, and unacetylated (free) CoA in green microalgae. A comparative study of three algal species that differ in TAG accumulation levels shows that during N starvation, Ac-CoA levels rapidly rise, preceding TAG accumulation in all tested species. The levels of Ac-CoA in the high TAG accumulator Chlorella desiccata exceed the levels in the moderate TAG accumulators Dunaliella tertiolecta and Chlamydomonas reinhardtii. Similarly, malonyl-CoA and free CoA levels also increase, but to lower extents. Calculated cellular concentrations of Ac-CoA are far lower than reported K mAc-CoA values of plastidic Ac-CoA carboxylase (ptACCase) in plants. Transcript level analysis of plastidic pyruvate dehydrogenase (ptPDH), the major chloroplastic Ac-CoA producer, revealed rapid induction in parallel with Ac-CoA accumulation in C. desiccata, but not in D. tertiolecta or C. reinhardtii. It is proposed that the capacity to accumulate high TAG levels in green algae critically depends on their ability to divert carbon flow towards Ac-CoA. This requires elevation of the chloroplastic CoA pool level and enhancement of Ac-CoA biosynthesis. These conclusions may have important implications for future genetic manipulation to enhance TAG biosynthesis in green algae. PMID:25922486

  5. Enhanced acetyl-CoA production is associated with increased triglyceride accumulation in the green alga Chlorella desiccata.

    PubMed

    Avidan, Omri; Brandis, Alexander; Rogachev, Ilana; Pick, Uri

    2015-07-01

    Triglycerides (TAGs) from microalgae can be utilized as food supplements and for biodiesel production, but little is known about the regulation of their biosynthesis. This work aimed to test the relationship between acetyl-CoA (Ac-CoA) levels and TAG biosynthesis in green algae under nitrogen deprivation. A novel, highly sensitive liquid chromatography mass spectrometry (LC-MS/MS) technique enabled us to determine the levels of Ac-CoA, malonyl-CoA, and unacetylated (free) CoA in green microalgae. A comparative study of three algal species that differ in TAG accumulation levels shows that during N starvation, Ac-CoA levels rapidly rise, preceding TAG accumulation in all tested species. The levels of Ac-CoA in the high TAG accumulator Chlorella desiccata exceed the levels in the moderate TAG accumulators Dunaliella tertiolecta and Chlamydomonas reinhardtii. Similarly, malonyl-CoA and free CoA levels also increase, but to lower extents. Calculated cellular concentrations of Ac-CoA are far lower than reported K mAc-CoA values of plastidic Ac-CoA carboxylase (ptACCase) in plants. Transcript level analysis of plastidic pyruvate dehydrogenase (ptPDH), the major chloroplastic Ac-CoA producer, revealed rapid induction in parallel with Ac-CoA accumulation in C. desiccata, but not in D. tertiolecta or C. reinhardtii. It is proposed that the capacity to accumulate high TAG levels in green algae critically depends on their ability to divert carbon flow towards Ac-CoA. This requires elevation of the chloroplastic CoA pool level and enhancement of Ac-CoA biosynthesis. These conclusions may have important implications for future genetic manipulation to enhance TAG biosynthesis in green algae. PMID:25922486

  6. Structural Features of the Pseudomonas fluorescens Biofilm Adhesin LapA Required for LapG-Dependent Cleavage, Biofilm Formation, and Cell Surface Localization

    PubMed Central

    Boyd, Chelsea D.; Smith, T. Jarrod; El-Kirat-Chatel, Sofiane; Newell, Peter D.; Dufrêne, Yves F.

    2014-01-01

    The localization of the LapA protein to the cell surface is a key step required by Pseudomonas fluorescens Pf0-1 to irreversibly attach to a surface and form a biofilm. LapA is a member of a diverse family of predicted bacterial adhesins, and although lacking a high degree of sequence similarity, family members do share common predicted domains. Here, using mutational analysis, we determine the significance of each domain feature of LapA in relation to its export and localization to the cell surface and function in biofilm formation. Our previous work showed that the N terminus of LapA is required for cleavage by the periplasmic cysteine protease LapG and release of the adhesin from the cell surface under conditions unfavorable for biofilm formation. We define an additional critical region of the N terminus of LapA required for LapG proteolysis. Furthermore, our results suggest that the domains within the C terminus of LapA are not absolutely required for biofilm formation, export, or localization to the cell surface, with the exception of the type I secretion signal, which is required for LapA export and cell surface localization. In contrast, deletion of the central repetitive region of LapA, consisting of 37 repeats of 100 amino acids, results in an inability to form a biofilm. We also used single-molecule atomic force microscopy to further characterize the role of these domains in biofilm formation on hydrophobic and hydrophilic surfaces. These studies represent the first detailed analysis of the domains of the LapA family of biofilm adhesin proteins. PMID:24837291

  7. Heat production by energy viscous dissipation at the stage of the Earth's accumulation.

    NASA Astrophysics Data System (ADS)

    Yurie Khachay, Professor; Olga Hachay, Professor

    2016-04-01

    In [1] it is suggested the model of Sun's protoplanetary cloud matter differentiation during the process of terrestrial planets accumulation. In [2] it was shown that the energy released during the decay of short-lived radioactive elements in the small size more than 50 km, it is enough that the temperature inside of the protoplanet becomes larger than the temperature of iron melting. It provides a realization of the matter differentiation process and convection development inside the inner envelopes. In [3] it is shown that during the sequence of changes in the growth of accumulated protoplanets, three types of driving mechanisms of convection are realized: internal heat sources; heated top; finally in the outer forming core of the Earth, heated from bottom and chemical and thermal convection. At all stages of proto Earth's development the convective heat-mass transfer becomes a most significant factor in the dynamics of the planet. However, the heat release due to friction in the viscous liquid is still considered only for the formed planetary envelopes with a constant radius and angular speed. In this paper we present the first results of numerical modeling of thermal evolution of 3D spherical segment for a protoplanet with increasing radius. To describe the planetary accumulation Safronov equation is used [4]. For the quantitative determination of the released heat by viscous friction a system of hydro dynamic equations of a viscous liquid is used. The obtained results show that the heat input due to viscous friction heat release at the early stage of planetary accumulation was very significant. This work was supported by grant RFFI №16-05-00540 Reference. 1. Anfilogov V., Khachay Y., 2015, Some Aspects of the Solar System Formation. Springer Briefs of the Earth Sciences. 75p 2. Anfilogov V., Khachay Y., 2005, A possible variant of matter differentiation on the initial stage of Earth's forming. DAN, V. 403, No 6, pp. 803-806. 3. Khachay Yu. Realization of

  8. Export Production Fluctuations in the Eastern Equatorial Pacific during the Pliocene-Pleistocene: Reconstruction Using Barite Accumulation Rates

    NASA Astrophysics Data System (ADS)

    Paytan, A.; Ma, Z.; Ravelo, A. C.; Liu, Z.

    2014-12-01

    Over the last 5 million years, Earth has experienced a transition from warmer climates to cooler climates. It is not clear how these changes affected export productivity in the Equatorial Pacific (EEP) and what are the potential feedbacks between ocean productivity and climate? To address these questions we use barite accumulation rates to reconstruct export productivity in the eastern equatorial Pacific (ODP Site 849) and compare the record to sea surface temperature (SST) fluctuations and other productivity proxies over the past 5.3 Ma. We find that export productivity fluctuated considerably on multiple time scales. During the Pliocene between 4.5 and 3 Ma, export productivity was on average higher (~50 g C m-2 yr-1) than during the Pleistocene (~ 35 g C m-2 yr-1). In the Pleistocene a trend of decreasing export production occurred between 3 Ma and 1 Ma (from ~60 to ~20 g C m-2 yr-1) followed by an increase over the last million years. Our record reveal decoupling between export productivity and SST on long (million year) time scales as previously suggested. Throughout this time interval shorter orbital-scale large amplitude fluctuations (between 10 and 100 g C m-2 yr-1) in export productivity are observed and export production was generally higher during cold periods or during transitions. Results from this study suggest that in the EEP mechanisms that affect carbon export on orbital time scales differed from those operating on longer time scales.

  9. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  10. LAP6/POLYKETIDE SYNTHASE A and LAP5/POLYKETIDE SYNTHASE B encode hydroxyalkyl α-pyrone synthases required for pollen development and sporopollenin biosynthesis in Arabidopsis thaliana.

    PubMed

    Kim, Sung Soo; Grienenberger, Etienne; Lallemand, Benjamin; Colpitts, Che C; Kim, Sun Young; Souza, Clarice de Azevedo; Geoffroy, Pierrette; Heintz, Dimitri; Krahn, Daniel; Kaiser, Markus; Kombrink, Erich; Heitz, Thierry; Suh, Dae-Yeon; Legrand, Michel; Douglas, Carl J

    2010-12-01

    Plant type III polyketide synthases (PKSs) catalyze the condensation of malonyl-CoA units with various CoA ester starter molecules to generate a diverse array of natural products. The fatty acyl-CoA esters synthesized by Arabidopsis thaliana ACYL-COA SYNTHETASE5 (ACOS5) are key intermediates in the biosynthesis of sporopollenin, the major constituent of exine in the outer pollen wall. By coexpression analysis, we identified two Arabidopsis PKS genes, POLYKETIDE SYNTHASE A (PKSA) and PKSB (also known as LAP6 and LAP5, respectively) that are tightly coexpressed with ACOS5. Recombinant PKSA and PKSB proteins generated tri-and tetraketide α-pyrone compounds in vitro from a broad range of potential ACOS5-generated fatty acyl-CoA starter substrates by condensation with malonyl-CoA. Furthermore, substrate preference profile and kinetic analyses strongly suggested that in planta substrates for both enzymes are midchain- and ω-hydroxylated fatty acyl-CoAs (e.g., 12-hydroxyoctadecanoyl-CoA and 16-hydroxyhexadecanoyl-CoA), which are the products of sequential actions of anther-specific fatty acid hydroxylases and acyl-CoA synthetase. PKSA and PKSB are specifically and transiently expressed in tapetal cells during microspore development in Arabidopsis anthers. Mutants compromised in expression of the PKS genes displayed pollen exine layer defects, and a double pksa pksb mutant was completely male sterile, with no apparent exine. These results show that hydroxylated α-pyrone polyketide compounds generated by the sequential action of ACOS5 and PKSA/B are potential and previously unknown sporopollenin precursors. PMID:21193570

  11. Bottlenecks in carotenoid biosynthesis and accumulation in rice endosperm are influenced by the precursor-product balance.

    PubMed

    Bai, Chao; Capell, Teresa; Berman, Judit; Medina, Vicente; Sandmann, Gerhard; Christou, Paul; Zhu, Changfu

    2016-01-01

    The profile of secondary metabolites in plants reflects the balance of biosynthesis, degradation and storage, including the availability of precursors and products that affect the metabolic equilibrium. We investigated the impact of the precursor-product balance on the carotenoid pathway in the endosperm of intact rice plants because this tissue does not normally accumulate carotenoids, allowing us to control each component of the pathway. We generated transgenic plants expressing the maize phytoene synthase gene (ZmPSY1) and the bacterial phytoene desaturase gene (PaCRTI), which are sufficient to produce β-carotene in the presence of endogenous lycopene β-cyclase. We combined this mini-pathway with the Arabidopsis thaliana genes AtDXS (encoding 1-deoxy-D-xylulose 5-phosphate synthase, which supplies metabolic precursors) or AtOR (the ORANGE gene, which promotes the formation of a metabolic sink). Analysis of the resulting transgenic plants suggested that the supply of isoprenoid precursors from the MEP pathway is one of the key factors limiting carotenoid accumulation in the endosperm and that the overexpression of AtOR increased the accumulation of carotenoids in part by up-regulating a series of endogenous carotenogenic genes. The identification of metabolic bottlenecks in the pathway will help to refine strategies for the creation of engineered plants with specific carotenoid profiles. PMID:25857664

  12. Enhanced lipid accumulation and biodiesel production by oleaginous Chlorella protothecoides under a structured heterotrophic-iron (II) induction strategy.

    PubMed

    Li, Yuqin; Mu, Jinxiu; Chen, Di; Xu, Hua; Han, Fangxin

    2015-05-01

    A structured heterotrophic-iron (II) induction (HII) strategy was proposed to enhance lipid accumulation in oleaginous Chlorella protothecoides. C. protothecoides subjected to heterotrophic-iron (II) induction achieved a favorable lipid accumulation up to 62 % and a maximum lipid productivity of 820.17 mg/day, representing 2.78-fold and 3.64-fold increase respectively over heterotrophic cultivation alone. HII-induced cells produced significantly elevated levels of 16:0, 18:1(Δ9), and 18:2(Δ9,12) fatty acids (over 90 %). The lipid contents and plant lipid-like fatty acid compositions exhibit the potential of HII-induced C. protothecoides as biodiesel feedstock. Furthermore, 31 altered proteins in HII-induced algal cells were successfully identified. These differentially expressed proteins were assigned into nine molecular function categories, including carbohydrate metabolism, lipid biosynthesis, Calvin cycle, cellular respiration, photosynthesis, energy and transport, protein biosynthesis, regulate and defense, and unclassified. Analysis using the Kyoto encyclopedia of genes and genomes and gene ontology annotation showed that malic enzyme, acyltransferase, and ACP were key metabolic checkpoints found to modulate lipid accumulation in C. protothecoides. The results provided possible applications of HII cultivation strategy in other microalgal species and new possibilities in developing genetic and metabolic engineering microalgae for desirable lipid productivity. PMID:25724298

  13. Material characterization of structural adhesives in the lap shear mode

    NASA Technical Reports Server (NTRS)

    Sancaktar, E.; Schenck, S. C.

    1983-01-01

    A general method for characterizing structual adhesives in the bonded lap shear mode is proposed. Two approaches in the form of semiempirical and theoretical approaches are used. The semiempirical approach includes Ludwik's and Zhurkov's equations to describe respectively, the failure stresses in the constant strain rate and constant stress loading modes with the inclusion of the temperature effects. The theoretical approach is used to describe adhesive shear stress-strain behavior with the use of viscoelastic or nonlinear elastic constitutive equations. Two different model adhesives are used in the single lap shear mode with titanium adherends. These adhesives (one of which was developed at NASA Langley Research Center) are currently considered by NASA for possible aerospace applications. Use of different model adhesives helps in assessment of the generality of the method.

  14. FRICTION-STIR-LAP-WELDS OF AA6111 ALUMINUM ALLOY

    SciTech Connect

    Yadava, Manasij; Mishra, Rajiv S.; Chen, Y. L.; Gayden, X.; Grant, Glenn J.

    2007-01-09

    Lap joints of 1 mm thick AA6111 aluminum sheets were made by friction stir welding, using robotic and conventional machines. Welds were made for advancing as well as retreating side loading. Thinning in welds was quantified. Lap shear test of welds was conducted in as-welded and paint-baked conditions. Conventional machine welds showed less thinning and better strength than robotic machine welds. Process forces in conventional machine welding were higher. Paint bake treatment improved the weld strength; but the improvement varied with process parameters. Advancing side loaded welds achieved higher strength than the retreating side loaded welds. Fracture location was found to occur on the loaded side of the weld and along the thinning defect.

  15. The impact of lubricants on the precision lapping process.

    PubMed

    Jiang, Xionghua; Chen, Zhenxing; Wolfram, Joy; Wei, Zhongxian; Shen, Yuqiu; Yang, Zhizhou

    2014-12-01

    The impact of lubricants on pole-tip recession and surface morphology of hard disk drive heads in the precision lapping process was investigated with atomic force microscopy, scanning electron microscopy, and auger electron spectroscopy. In particular, the effects of deionized water, hydrocarbon oil, ethanediol, isopropanol, and ethanol lubricants were evaluated. The results reveal that proper selection of lubricant is critical for achieving optimal performance in the lapping process. A mixture of 68% hydrocarbon oil, 30% isopropanol, and 2% octadecenoic acid was found to yield the most favorable results, displaying a writer shield recession, first shield of reader recession, and surface roughness of 0.423, 0.581, and 0.242 nm, respectively. PMID:25387606

  16. Identification of bolted lap joints parameters in assembled structures

    NASA Astrophysics Data System (ADS)

    Ahmadian, Hamid; Jalali, Hassan

    2007-02-01

    Bolted lap joints have significant influence on the dynamical behaviour of the assembled structures due to creation of strong local flexibility and damping. In modelling the dynamical behaviour of assembled structures the joint interface model must be represented accurately. A nonlinear model for bolted lap joints and interfaces is proposed capable of representing the dominant physics involved in the joint such as micro/macro-slip. The joint interface is modelled using a combination of linear and nonlinear springs and a damper to simulate the damping effects of the joint. An estimate of the response of the structure with a nonlinear model for the bolted joint under external excitations is obtained using the method of multiple scales. The parameters of the model, i.e. the spring constants and the damper coefficient, are functions of normal and tangential stresses at the joint interface and are identified by minimizing the difference between the model predictions and the experimentally measured data.

  17. Clofazimine Biocrystal Accumulation in Macrophages Upregulates Interleukin 1 Receptor Antagonist Production To Induce a Systemic Anti-Inflammatory State.

    PubMed

    Yoon, Gi S; Keswani, Rahul K; Sud, Sudha; Rzeczycki, Phillip M; Murashov, Mikhail D; Koehn, Tony A; Standiford, Theodore J; Stringer, Kathleen A; Rosania, Gus R

    2016-06-01

    Clofazimine (CFZ) is a poorly soluble antibiotic and anti-inflammatory drug indicated for the treatment of leprosy. In spite of its therapeutic value, CFZ therapy is accompanied by the formation of drug biocrystals that accumulate within resident tissue macrophages, without obvious toxicological manifestations. Therefore, to specifically elucidate the off-target consequences of drug bioaccumulation in macrophages, we compared the level of inflammasome activation in CFZ-accumulating organs (spleen, liver and lung) in mice after 2 and 8 weeks of CFZ treatment when the drug exists in soluble and insoluble (biocrystalline) forms, respectively. Surprisingly, the results showed a drastic reduction in caspase 1 and interleukin-1β (IL-1β) cleavage in the livers of mice treated with CFZ for 8 weeks (8-week-CFZ-treated mice) compared to 2-week-CFZ-treated and control mice, which was accompanied by a 3-fold increase in hepatic IL-1 receptor antagonist (IL-1RA) production and a 21-fold increase in serum IL-1RA levels. In the lung and spleen, IL-1β cleavage and tumor necrosis factor alpha expression were unaffected by soluble or biocrystal CFZ forms. Functionally, there was a drastic reduction of carrageenan- and lipopolysaccharide-induced inflammation in the footpads and lungs, respectively, of 8-week-CFZ-treated mice. This immunomodulatory activity of CFZ biocrystal accumulation was attributable to the upregulation of IL-1RA, since CFZ accumulation had minimal effect in IL-1RA knockout mice or 2-week-CFZ-treated mice. In conclusion, CFZ accumulation and biocrystal formation in resident tissue macrophages profoundly altered the host's immune system and prompted an IL-1RA-dependent, systemic anti-inflammatory response. PMID:27021320

  18. Investigation into Interface Lifting Within FSW Lap Welds

    SciTech Connect

    K. S. Miller; C. R. Tolle; D. E. Clark; C. I. Nichol; T. R. McJunkin; H. B. Smartt

    2008-06-01

    Friction stir welding (FSW) is rapidly penetrating the welding market in many materials and applications, particularly in aluminum alloys for transportation applications. As this expansion outside the research laboratory continues, fitness for service issues will arise, and process control and NDE methods will become important determinants of continued growth. The present paper describes research into FSW weld nugget flaw detection within aluminum alloy lap welds. We present results for two types of FSW tool designs: a smooth pin tool and a threaded pin tool. We show that under certain process parameters (as monitored during welding with a rotating dynamometer that measures x, y, z, and torque forces) and tooling designs, FSW lap welds allow significant nonbonded interface lifting of the lap joint, while forming a metallurgical bond only within the pin region of the weld nugget. These lifted joints are often held very tightly together even though unbonded, and might be expected to pass cursory NDE while representing a substantial compromise in joint mechanical properties. The phenomenon is investigated here via radiographic and ultrasonic NDE techniques, with a copper foil marking insert (as described elsewhere) and by the tensile testing of joints. As one would expect, these results show that tool design and process parameters significantly affect plactic flow and this lifted interface. NDE and mechanical strength ramifications of this defect are discussed.

  19. Residual Strength Analyses of Riveted Lap-Splice Joints

    NASA Technical Reports Server (NTRS)

    Seshadri, B. R.; Newman, J. C., Jr.

    2000-01-01

    The objective of this paper was to analyze the crack-linkup behavior in riveted-stiffened lap-splice joint panels with small multiple-site damage (MSD) cracks at several adjacent rivet holes. Analyses are based on the STAGS (STructural Analysis of General Shells) code with the critical crack-tip-opening angle (CTOA) fracture criterion. To account for high constraint around a crack front, the "plane strain core" option in STAGS was used. The importance of modeling rivet flexibility with fastener elements that accurately model load transfer across the joint is discussed. Fastener holes are not modeled but rivet connectivity is accounted for by attaching rivets to the sheet on one side of the cracks that simulated both the rivet diameter and MSD cracks. Residual strength analyses made on 2024-T3 alloy (1.6-mm thick) riveted-lap-splice joints with a lead crack and various size MSD cracks were compared with test data from Boeing Airplane Company. Analyses were conducted for both restrained and unrestrained buckling conditions. Comparison of results from these analyses and results from lap-splice-joint test panels, which were partially restrained against buckling indicate that the test results were bounded by the failure loads predicted by the analyses with restrained and unrestrained conditions.

  20. Genome-scale metabolic modeling and in silico analysis of lipid accumulating yeast Candida tropicalis for dicarboxylic acid production.

    PubMed

    Mishra, Pranjul; Park, Gyu-Yeon; Lakshmanan, Meiyappan; Lee, Hee-Seok; Lee, Hongweon; Chang, Matthew Wook; Ching, Chi Bun; Ahn, Jungoh; Lee, Dong-Yup

    2016-09-01

    Recently, the bio-production of α,ω-dicarboxylic acids (DCAs) has gained significant attention, which potentially leads to the replacement of the conventional petroleum-based products. In this regard, the lipid accumulating yeast Candida tropicalis, has been recognized as a promising microbial host for DCA biosynthesis: it possess the unique ω-oxidation pathway where the terminal carbon of α-fatty acids is oxidized to form DCAs with varying chain lengths. However, despite such industrial importance, its cellular physiology and lipid accumulation capability remain largely uncharacterized. Thus, it is imperative to better understand the metabolic behavior of this lipogenic yeast, which could be achieved by a systems biological approach. To this end, herein, we reconstructed the genome-scale metabolic model of C. tropicalis, iCT646, accounting for 646 unique genes, 945 metabolic reactions, and 712 metabolites. Initially, the comparative network analysis of iCT646 with other yeasts revealed several distinctive metabolic reactions, mainly within the amino acid and lipid metabolism including the ω-oxidation pathway. Constraints-based flux analysis was, then, employed to predict the in silico growth rates of C. tropicalis which are highly consistent with the cellular phenotype observed in glucose and xylose minimal media chemostat cultures. Subsequently, the lipid accumulation capability of C. tropicalis was explored in comparison with Saccharomyces cerevisiae, indicating that the formation of "citrate pyruvate cycle" is essential to the lipid accumulation in oleaginous yeasts. The in silico flux analysis also highlighted the enhanced ability of pentose phosphate pathway as NADPH source rather than malic enzyme during lipogenesis. Finally, iCT646 was successfully utilized to highlight the key directions of C. tropicalis strain design for the whole cell biotransformation application to produce long-chain DCAs from alkanes. Biotechnol. Bioeng. 2016;113: 1993-2004.

  1. Localized accumulation of angiotensin II and production of angiotensin-(1-7) in rat luteal cells and effects on steroidogenesis.

    PubMed

    Pepperell, John R; Nemeth, Gabor; Yamada, Yuji; Naftolin, Frederick; Merino, Maricruz

    2006-08-01

    These studies aim to investigate subcellular distribution of angiotensin II (ANG II) in rat luteal cells, identify other bioactive angiotensin peptides, and investigate a role for angiotensin peptides in luteal steroidogenesis. Confocal microscopy showed ANG II distributed within the cytoplasm and nuclei of luteal cells. HPLC analysis showed peaks that eluted with the same retention times as ANG-(1-7), ANG II, and ANG III. Their relative concentrations were ANG II >or= ANG-(1-7) > ANG III, and accumulation was modulated by quinapril, an inhibitor of angiotensin-converting enzyme (ACE), Z-proprolinal (ZPP), an inhibitor of prolyl endopeptidase (PEP), and parachloromercurylsulfonic acid (PCMS), an inhibitor of sulfhydryl protease. Phenylmethylsulfonyl fluoride (PMSF), a serine protease inhibitor, did not affect peptide accumulation. Quinapril, ZPP, PCMS, and PMSF, as well as losartan and PD-123319, the angiotensin receptor type 1 (AT1) and type 2 (AT2) receptor antagonists, were used in progesterone production studies. ZPP significantly reduced luteinizing hormone (LH)-dependent progesterone production (P < 0.05). Quinapril plus ZPP had a greater inhibitory effect on LH-stimulated progesterone than either inhibitor alone, but this was not reversed by exogenous ANG II or ANG-(1-7). Both PCMS and PMSF acutely blocked LH-stimulated progesterone, and PCMS blocked LH-sensitive cAMP accumulation. Losartan inhibited progesterone production in permeabilized but not intact luteal cells and was reversed by ANG II. PD-123319 had no significant effect on luteal progesterone production in either intact or permeabilized cells. These data suggest that steroidogenesis may be modulated by angiotensin peptides that act in part through intracellular AT1 receptors. PMID:16478781

  2. Lap Shear and Impact Testing of Ochre and Beeswax in Experimental Middle Stone Age Compound Adhesives.

    PubMed

    Kozowyk, P R B; Langejans, G H J; Poulis, J A

    2016-01-01

    The production of compound adhesives using disparate ingredients is seen as some of the best evidence of advanced cognition outside of the use of symbolism. Previous field and laboratory testing of adhesives has shown the complexities involved in creating an effective Middle Stone Age glue using Acacia gum. However, it is currently unclear how efficient different adhesive recipes are, how much specific ingredients influence their performance, and how difficult it may have been for those ingredients to be combined to maximum effect. We conducted a series of laboratory-based lap shear and impact tests, following modern adhesion testing standards, to determine the efficacy of compound adhesives, with particular regard to the ingredient ratios. We tested rosin (colophony) and gum adhesives, containing additives of beeswax and ochre in varying ratios. During both lap shear and impact tests compound rosin adhesives performed better than single component rosin adhesives, and pure acacia gum was the strongest. The large difference in performance between each base adhesive and the significant changes in performance that occur due to relatively small changes in ingredient ratios lend further support to the notion that high levels of skill and knowledge were required to consistently produce the most effective adhesives. PMID:26983080

  3. Lap Shear and Impact Testing of Ochre and Beeswax in Experimental Middle Stone Age Compound Adhesives

    PubMed Central

    2016-01-01

    The production of compound adhesives using disparate ingredients is seen as some of the best evidence of advanced cognition outside of the use of symbolism. Previous field and laboratory testing of adhesives has shown the complexities involved in creating an effective Middle Stone Age glue using Acacia gum. However, it is currently unclear how efficient different adhesive recipes are, how much specific ingredients influence their performance, and how difficult it may have been for those ingredients to be combined to maximum effect. We conducted a series of laboratory-based lap shear and impact tests, following modern adhesion testing standards, to determine the efficacy of compound adhesives, with particular regard to the ingredient ratios. We tested rosin (colophony) and gum adhesives, containing additives of beeswax and ochre in varying ratios. During both lap shear and impact tests compound rosin adhesives performed better than single component rosin adhesives, and pure acacia gum was the strongest. The large difference in performance between each base adhesive and the significant changes in performance that occur due to relatively small changes in ingredient ratios lend further support to the notion that high levels of skill and knowledge were required to consistently produce the most effective adhesives. PMID:26983080

  4. House crickets can accumulate polybrominated diphenyl ethers (PBDEs) directly from polyurethane foam common in consumer products.

    PubMed

    Gaylor, Michael O; Harvey, Ellen; Hale, Robert C

    2012-02-01

    Polybrominated diphenyl ether (PBDE) flame retardants are added at percent levels to many polymers and textiles abundant in human spaces and vehicles, wherein they have been long assumed to be tightly sequestered. However, the mgkg(-1) burdens recently detected in indoor dust testify to substantial releases. The bulk of released PBDEs remain in the terrestrial environment, yet comparatively little research focuses on this compartment. There, insects/arthropods, such as crickets, are the most abundant invertebrate organisms and facilitate the trophic transfer of contaminants by breaking down complex organic matter (including discarded polymers) and serving as food for other organisms. Our experiments revealed that house crickets (Acheta domesticus) provided uncontaminated food and free access to PUF containing Penta-BDE (8.7%drywt) for 28 d accumulated substantial PBDE body burdens. Crickets allowed to depurate gut contents exhibited whole body burdens of up to 13.4 mg kg(-1) lipid ΣPenta-BDE, 1000-fold higher than typically reported in humans. Non-depurated crickets and molted exoskeletons incurred even higher ΣPenta-BDE, up to 80.6 and 63.3 mg kg(-1) lipid, respectively. Congener patterns of whole crickets and molts resembled those of PUF and the commercial Penta-BDE formulation, DE-71, indicative of minimal discrimination or biotransformation. Accumulation factor (AF) calculations were hampered by uncertainties in determining actual PUF ingestion. However, estimated AFs were low, in the range of 10(-4)-10(-3), suggesting that polymer-PBDE interactions limited uptake. Nonetheless, results indicate that substantial PBDE burdens may be incurred by insects in contact with current-use and derelict treated polymers within human spaces and solid waste disposal sites (e.g. landfills, automotive dumps, etc.). Once ingested, even burdens not absorbed across the gut wall may be dispersed within proximate terrestrial food webs via the insect's movements and/or predation

  5. Production of targeted poly(3-hydroxyalkanoates) copolymers by glycogen accumulating organisms using acetate as sole carbon source.

    PubMed

    Dai, Yu; Yuan, Zhiguo; Jack, Kevin; Keller, Jurg

    2007-05-01

    One of the main limitations in bacterial polyhydroxyalkanoate (PHA) production with mixed cultures is the fact that primarily polyhydroxybutyrate (PHB) homopolymers are generated from acetate as the main carbon source, which is brittle and quite fragile. The incorporation of different 3-hydroxyalkanoate (HA) components into the polymers requires the addition of additional carbon sources, leading to extra costs and complexity. In this study, the production of poly(3-hydroxybutyrate (3HB)-co-3-hydroxyvalerate (3HV)-co-3-hydroxy-2-methylvalerate (3HMV)), with 7-35C-mol% of 3HV fractions from acetate as the only carbon source was achieved with the use of glycogen accumulating organisms (GAOs). An enriched GAO culture was obtained in a lab-scale reactor operated under alternating anaerobic and aerobic conditions with acetate fed at the beginning of the anaerobic period. The production of PHAs utilizing the enriched GAO culture was investigated under both aerobic and anaerobic conditions. A polymer content of 14-41% of dry cell weight was obtained. The PHA product accumulated by GAOs under anaerobic conditions contained a relatively constant proportion of non-3HB monomers (30+/-5C-mol%), irrespective of the amount of acetate assimilated. In contrast, under aerobic conditions, GAOs only produced 3HB monomers from acetate causing a gradually decreasing 3HV fraction during this aerobic feeding period. The PHAs were characterized by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The data demonstrated that the copolymers possessed similar characteristics to those of commercially available poly(3HB-co-3HV) (PHBV) products. The PHAs produced under solely anaerobic conditions possessed lower melting points and crystallinity, higher molecular weights, and narrower molecular-weight distributions, compared to the aerobically produced polymers. This paper hence demonstrates the significant potential of GAOs to produce high quality polymers from a

  6. Superior triacylglycerol (TAG) accumulation in starchless mutants of Scenedesmus obliquus: (II) evaluation of TAG yield and productivity in controlled photobioreactors

    PubMed Central

    2014-01-01

    Background Many microalgae accumulate carbohydrates simultaneously with triacylglycerol (TAG) upon nitrogen starvation, and these products compete for photosynthetic products and metabolites from the central carbon metabolism. As shown for starchless mutants of the non-oleaginous model alga Chlamydomonas reinhardtii, reduced carbohydrate synthesis can enhance TAG production. However, these mutants still have a lower TAG productivity than wild-type oleaginous microalgae. Recently, several starchless mutants of the oleaginous microalga Scenedesmus obliquus were obtained which showed improved TAG content and productivity. Results The most promising mutant, slm1, is compared in detail to wild-type S. obliquus in controlled photobioreactors. In the slm1 mutant, the maximum TAG content increased to 57 ± 0.2% of dry weight versus 45 ± 1% in the wild type. In the wild type, TAG and starch were accumulated simultaneously during initial nitrogen starvation, and starch was subsequently degraded and likely converted into TAG. The starchless mutant did not produce starch and the liberated photosynthetic capacity was directed towards TAG synthesis. This increased the maximum yield of TAG on light by 51%, from 0.144 ± 0.004 in the wild type to 0.217 ± 0.011 g TAG/mol photon in the slm1 mutant. No differences in photosynthetic efficiency between the slm1 mutant and the wild type were observed, indicating that the mutation specifically altered carbon partitioning while leaving the photosynthetic capacity unaffected. Conclusions The yield of TAG on light can be improved by 51% by using the slm1 starchless mutant of S. obliquus, and a similar improvement seems realistic for the areal productivity in outdoor cultivation. The photosynthetic performance is not negatively affected in the slm1 and the main difference with the wild type is an improved carbon partitioning towards TAG. PMID:24883102

  7. Nitrate reductase-mediated NO production enhances Cd accumulation in Panax notoginseng roots by affecting root cell wall properties.

    PubMed

    Kan, Qi; Wu, Wenwei; Yu, Wenqian; Zhang, Jiarong; Xu, Jin; Rengel, Zed; Chen, Limei; Cui, Xiuming; Chen, Qi

    2016-04-01

    Panax notoginseng (Burk) F. H. Chen is a traditional medicinal herb in China. However, the high capacity of its roots to accumulate cadmium (Cd) poses a potential risk to human health. Although there is some evidence for the involvement of nitric oxide (NO) in mediating Cd toxicity, the origin of Cd-induced NO and its function in plant responses to Cd remain unknown. In this study, we examined NO synthesis and its role in Cd accumulation in P. notoginseng roots. Cd-induced NO production was significantly decreased by application of the nitrate reductase inhibitor tungstate but not the nitric oxide synthase inhibitor L-NAME (N(G)-methyl-l-arginine acetate), indicating that nitrate reductase is the major contributor to Cd-induced NO production in P. notoginseng roots. Under conditions of Cd stress, sodium nitroprusside (SNP, an NO donor) increased Cd accumulation in root cell walls but decreased Cd translocation to the shoot. In contrast, the NO scavenger cPTIO (2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) and tungstate both significantly decreased NO-increased Cd retention in root cell walls. The amounts of hemicellulose 1 and pectin, together with pectin methylesterase activity, were increased with the addition of SNP but were decreased by cPTIO and tungstate. Furthermore, increases or decreases in hemicellulose 1 and pectin contents as well as pectin methylesterase activity fit well with the increased or decreased retention of Cd in the cell walls of P. notoginseng roots. The results suggest that nitrate reductase-mediated NO production enhances Cd retention in P. notoginseng roots by modulating the properties of the cell wall. PMID:26956919

  8. Optimal tubular adhesive-bonded lap joint of the carbon fiber epoxy composite shaft

    NASA Astrophysics Data System (ADS)

    Kim, Ki S.; Kim, Won T.; Lee, Dai G.; Jun, Eui J.

    The effects of the adhesive thickness and the adherend surface roughness on the fatigue strength of a tubular adhesive-bonded single lap joint were investigated using fatigue test specimens whose adherends were made of S45C carbon steel. Results of fatigue tests showed that the optimal arithmetic surface roughness of the adherends is about 2 microns and the optimal adhesive thickness is about 0.15 mm. Using these values, the prototype torsional adhesive joints were manufactured for power transmission shafts of an automotive vehicle or a small helicopter, and static tests under torque were performed on a single-lap joint, a single-lap joint with scarf, a double-lap joint, and a double-lap joint with scarf. It was found that the double-lap joint was superior among the joints, in terms of torque capacity and manufacturing cost.

  9. Guanidine-phosphate non-covalent interaction in LAP crystal growth solution evidenced from spectroscopy studies

    NASA Astrophysics Data System (ADS)

    Wang, L.; Zhang, G. H.; Wang, X. Q.; Zhu, L. Y.; Xu, D.

    2015-09-01

    The similar L-arginine molecule aggregation has been found in L-arginine (LA) and L-arginine phosphate monohydrate (LAP) aqueous solutions. The special fluorescence emission at 380 nm of LA aggregates in LAP solution has been found, compared with the emission of LA solution at 415 nm, which has an obvious blue shift. By comparing the fluorescence spectra of several solutions for L-arginine and L-lysine salts, the interaction between phosphate and guanidine in LAP solution was considered to be the cause of its special fluorescence emission. Meanwhile, when LAP molecule formed in solution, the fluorescence emission wavelength and the UV absorption intensity at 296 nm of L-arginine solutions have mutated. Therefore, the group interaction involved by guanidine has changed the fluorescence properties of L-arginine aggregates in LAP solution, indicating that the specific interaction between phosphate and guanidine exists in LAP molecule.

  10. Hsp65-producing Lactococcus lactis prevents experimental autoimmune encephalomyelitis in mice by inducing CD4+LAP+ regulatory T cells.

    PubMed

    Rezende, Rafael M; Oliveira, Rafael P; Medeiros, Samara R; Gomes-Santos, Ana C; Alves, Andrea C; Loli, Flávia G; Guimarães, Mauro A F; Amaral, Sylvia S; da Cunha, André P; Weiner, Howard L; Azevedo, Vasco; Miyoshi, Anderson; Faria, Ana M C

    2013-02-01

    Heat shock proteins (Hsps) participate in the cellular response to stress and they are hiperexpressed in inflammatory conditions. They are also known to play a major role in immune modulation, controlling, for instance, autoimmune responses. In this study, we showed that oral administration of a recombinant Lactococcus lactis strain that produces and releases LPS-free Hsp65 prevented the development of experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice. This was confirmed by the reduced inflammatory cell infiltrate and absence of injury signs in the spinal cord. The effect was associated with reduced IL-17 and increased IL-10 production in mesenteric lymph node and spleen cell cultures. Hsp65-producing-L. lactis-fed mice had a remarkable increase in the number of natural and inducible CD4+Foxp3+ regulatory T (Treg) cells and CD4+LAP+ (Latency-associated peptide) Tregs - which express the membrane-bound TGF-β - in spleen, inguinal and mesenteric lymph nodes as well as in spinal cord. Moreover, many Tregs co-expressed Foxp3 and LAP. In vivo depletion of LAP+ cells abrogated the effect of Hsp65-producing L. lactis in EAE prevention and worsened disease in medium-fed mice. Thus, Hsp65-L.lactis seems to boost this critical regulatory circuit involved in controlling EAE development in mice. PMID:22939403

  11. Hsp65-producing Lactococcus lactis prevents experimental autoimmune encephalomyelitis in mice by inducing CD4+LAP+ regulatory T cells

    PubMed Central

    Rezende, Rafael M.; Oliveira, Rafael P.; Medeiros, Samara R.; Gomes-Santos, Ana C.; Alves, Andrea C.; Loli, Flávia G.; Guimarães, Mauro A.F.; Amaral, Sylvia S.; da Cunha, André P.; Weiner, Howard L.; Azevedo, Vasco; Miyoshi, Anderson; Faria, Ana M.C.

    2013-01-01

    Heat shock proteins (Hsps) participate in the cellular response to stress and they are hiperexpressed in inflammatory conditions. They are also known to play a major role in immune modulation, controlling, for instance, autoimmune responses. In this study, we showed that oral administration of a recombinant Lactococcus lactis strain that produces and releases LPS-free Hsp65 prevented the development of experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice. This was confirmed by the reduced inflammatory cell infiltrate and absence of injury signs in the spinal cord. The effect was associated with reduced IL-17 and increased IL-10 production in mesenteric lymph node and spleen cell cultures. Hsp65-producing-L. lactis-fed mice had a remarkable increase in the number of natural and inducible CD4+Foxp3+ regulatory T (Treg) cells and CD4+LAP+ (Latency-associated peptide) Tregs - which express the membrane-bound TGF-β - in spleen, inguinal and mesenteric lymph nodes as well as in spinal cord. Moreover, many Tregs co-expressed Foxp3 and LAP. In vivo depletion of LAP+ cells abrogated the effect of Hsp65-producing L. lactis in EAE prevention and worsened disease in medium-fed mice. Thus, Hsp65-L.lactis seems to boost this critical regulatory circuit involved in controlling EAE development in mice. PMID:22939403

  12. Strategies for gas production from hydrate accumulations under various geologic conditions

    SciTech Connect

    Moridis, G.; Collett, T.

    2003-04-29

    In this paper we classify hydrate deposits in three classes according to their geologic and reservoir conditions, and discuss the corresponding production strategies. Simple depressurization appears promising in Class 1 hydrates, but its appeal decreases in Class 2 and Class 3 hydrates. The most promising production strategy in Class 2 hydrates involves combinations of depressurization and thermal stimulation, and is clearly enhanced by multi-well production-injection systems. The effectiveness of simple depressurization in Class 3 hydrates is limited, and thermal stimulation (alone or in combination with depressurization) through single well systems seems to be the strategy of choice in such deposits.

  13. Enhanced biomass production and lipid accumulation of Picochlorum atomus using light-emitting diodes (LEDs).

    PubMed

    Ra, Chae Hun; Kang, Chang-Han; Jung, Jang-Hyun; Jeong, Gwi-Taek; Kim, Sung-Koo

    2016-10-01

    The effects of light-emitting diode (LED) wavelength, light intensity, nitrate concentration, and time of exposure to different LED wavelength stresses in a two-phase culture on lipid production were evaluated in the microalga, Picochlorum atomus. The biomass produced by red LED light was higher than that produced by purple, blue, green, or yellow LED and fluorescent lights from first phase of two-phase culture. The highest lipid production of P. atomus was 50.3% (w/w) with green LED light at 2days of second phase as light stress. Fatty acid analysis of the microalgae showed that palmitic acid (C16:0) and linolenic acid (C18:3) accounted for 84-88% (w/w) of total fatty acids from P. atomus. The two-phase culture of P. atomus is suitable for biofuel production due to higher lipid productivity and favorable fatty acid composition. PMID:27474341

  14. ATP production from adenine by a self-coupling enzymatic process: high-level accumulation under ammonium-limited conditions.

    PubMed

    Maruyama, A; Fujio, T

    2001-03-01

    To improve ATP production from adenine, we optimized cultivation and reaction conditions for the ATP producing strain, Corynebacterium ammoniagenes KY13510. In the conventional method, 28% NH4OH has been used both to adjust pH during cultivation and reaction, and to provide nitrogen for cell growth. In the ATP-producing reaction, high concentrations of inorganic phosphate and magnesium ion are needed, which form magnesium ammonium phosphate (MgNH4PO4) precipitate. To keep inorganic phosphate and magnesium ions soluble in the reaction mixture, it was indispensable to add phytic acid as a chelating agent of divalent metal ions. Under such conditions, 37 mg/ml (61.2 mM) ATP was accumulated in 13 h (Appl. Microbiol. Biotechnol. 21, 143 1985). If ammonium ion was depleted from the reaction mixture to avoid MgNH4 PO4 formation, we expected that there was no need to add phytic acid and ATP accumulation might be improved. Therefore, we obtained the cultured broth of C. ammoniagenes KY13510 strain with low ammonium ion content (less than 1 mg/ml as NH3) by the method that a part of alkali solution (28% NH4OH) for pH control was replaced with 10 N KOH. Using this culture broth, ATP producing reaction was done in 2-liter jar fermentor, controlling the pH of the reaction mixture with 10 N KOH. Under these conditions, the rate of ATP accumulation improved greatly, and 70.6 mg/ml (117 mM) ATP was accumulated in 28 h. The molar conversion ratio from adenine to ATP was about 82%. Phytic acid was slightly inhibitory to ATP formation under these ammonium-limited conditions. PMID:11330681

  15. Methodology for assessing quantities of water and proppant injection, and water production associated with development of continuous petroleum accumulations

    USGS Publications Warehouse

    Haines, Seth S.

    2015-01-01

    The quantities of water and hydraulic fracturing proppant required for producing petroleum (oil, gas, and natural gas liquids) from continuous accumulations, and the quantities of water extracted during petroleum production, can be quantitatively assessed using a probabilistic approach. The water and proppant assessment methodology builds on the U.S. Geological Survey methodology for quantitative assessment of undiscovered technically recoverable petroleum resources in continuous accumulations. The U.S. Geological Survey assessment methodology for continuous petroleum accumulations includes fundamental concepts such as geologically defined assessment units, and probabilistic input values including well-drainage area, sweet- and non-sweet-spot areas, and success ratio within the untested area of each assessment unit. In addition to petroleum-related information, required inputs for the water and proppant assessment methodology include probabilistic estimates of per-well water usage for drilling, cementing, and hydraulic-fracture stimulation; the ratio of proppant to water for hydraulic fracturing; the percentage of hydraulic fracturing water that returns to the surface as flowback; and the ratio of produced water to petroleum over the productive life of each well. Water and proppant assessments combine information from recent or current petroleum assessments with water- and proppant-related input values for the assessment unit being studied, using Monte Carlo simulation, to yield probabilistic estimates of the volume of water for drilling, cementing, and hydraulic fracture stimulation; the quantity of proppant for hydraulic fracture stimulation; and the volumes of water produced as flowback shortly after well completion, and produced over the life of the well.

  16. Improving satellite rainfall accumulation using multiple microwave satellite soil moisture products is Australia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Real-time satellite precipitation product is important input information for streamflow forecasting and for understanding hydrological cycles in ungauged basins. The inner basins of Australia are monitored by a very sparse gauge network and rainfall estimation in the regions does not capture the var...

  17. Impact of organic production management on variety yield and grain arsenic accumulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The demand for organically produced rice increases each year. Organic rice production offers economic benefits to growers because the crop can be sold at a premium and input costs are generally lower. The objective of this experiment was to determine the agronomic performance of rice cultivars grown...

  18. Effect of surfactant on hydrolysis products accumulation and short-chain fatty acids (SCFA) production during mesophilic and thermophilic fermentation of waste activated sludge: kinetic studies.

    PubMed

    Zhang, Peng; Chen, Yinguang; Zhou, Qi

    2010-09-01

    In the presence of surfactant sodium dodecylbenzene sulfonate (SDBS) the hydrolysis products accumulation and the short-chain fatty acids (SCFA) production during waste activated sludge fermentation under mesophilic and thermophilic conditions was compared with that at room temperature. In order to understand the mechanism of significant amounts of mesophilic and thermophilic hydrolysis products and SCFA observed in the presence of surfactant, the kinetic models at different SDBS dosages were developed. It was found that SDBS increased the mesophilic and thermophilic hydrolysis rate significantly, and the maximum specific utilization of hydrolysis products increased at low SDBS and decreased at high one. However, the observed maximum specific utilization of SCFA decreased seriously with SDBS increase. In the presence of SDBS the decay rate of acidogenic bacteria not only was lower than that in the absence of SDBS but decreased with the increase of SDBS under either mesophilic or thermophilic conditions. PMID:20409704

  19. Correcting Errors in Catchment-Scale Satellite Rainfall Accumulation Using Microwave Satellite Soil Moisture Products

    NASA Astrophysics Data System (ADS)

    Ryu, D.; Crow, W. T.

    2011-12-01

    Streamflow forecasting in the poorly gauged or ungauged catchments is very difficult mainly due to the absence of the input forcing data for forecasting models. This challenge poses a threat to human safety and industry in the areas where proper warning system is not provided. Currently, a number of studies are in progress to calibrate streamflow models without relying on ground observations as an effort to construct a streamflow forecasting systems in the ungauged catchments. Also, recent advances in satellite altimetry and innovative application of the optical has enabled mapping streamflow rate and flood extent in the remote areas. In addition, remotely sensed hydrological variables such as the real-time satellite precipitation data, microwave soil moisture retrievals, and surface thermal infrared observations have the great potential to be used as a direct input or signature information to run the forecasting models. In this work, we evaluate a real-time satellite precipitation product, TRMM 3B42RT, and correct errors of the product using the microwave satellite soil moisture products over 240 catchments in Australia. The error correction is made by analyzing the difference between output soil moisture of a simple model forced by the TRMM product and the satellite retrievals of soil moisture. The real-time satellite precipitation products before and after the error correction are compared with the daily gauge-interpolated precipitation data produced by the Australian Bureau of Meteorology. The error correction improves overall accuracy of the catchment-scale satellite precipitation, especially the root mean squared error (RMSE), correlation, and the false alarm ratio (FAR), however, only a marginal improvement is observed in the probability of detection (POD). It is shown that the efficiency of the error correction is affected by the surface vegetation density and the annual precipitation of the catchments.

  20. Rice SPK, a Calmodulin-Like Domain Protein Kinase, Is Required for Storage Product Accumulation during Seed Development

    PubMed Central

    Asano, Takayuki; Kunieda, Noriko; Omura, Yuhi; Ibe, Hirokazu; Kawasaki, Tsutomu; Takano, Makoto; Sato, Miho; Furuhashi, Hideyuki; Mujin, Toshiyuki; Takaiwa, Fumio; Wu, Chuan-yin; Tada, Yuichi; Satozawa, Tomomi; Sakamoto, Masahiro; Shimada, Hiroaki

    2002-01-01

    Suc, an end product of photosynthesis, is metabolized by Suc synthase in sink organs as an initial step in the biosynthesis of storage products. Suc synthase activity is known to be regulated by reversible phosphorylation, but the details of this process are unclear at present. Rice SPK, a calcium-dependent protein kinase, is expressed uniquely in the endosperm of immature seed, and its involvement in the biosynthetic pathways of storage products was suggested. Antisense SPK transformants lacked the ability to accumulate storage products such as starch, but produced watery seed with a large amount of Suc instead, as the result of an inhibition of Suc degradation. Analysis of in vitro phosphorylation indicated that SPK phosphorylated specifically a Ser residue in Suc synthase that has been shown to be important for its activity in the degradation of Suc. This finding suggests that SPK is involved in the activation of Suc synthase. It appears that SPK is a Suc synthase kinase that may be important for supplying substrates for the biosynthesis of storage products. PMID:11910009

  1. An integrated system for the energy production and accumulation from renewable sources: a rural tower prototype

    NASA Astrophysics Data System (ADS)

    Di Francesco, Silvia; Petrozzi, Alessandro; Montesarchio, Valeria

    2014-05-01

    This research work presents the implementation of an architectural prototype aiming at the complete energy self-sufficiency through an integrated system based on renewable energy. It is suitable for historical buildings in rural areas, isolated but important from natural and architectonical point of view. In addition to the energy aspects, it is important to protect the impact in terms of land-use and environment. This idea is also especially powerful because in the rural countries there are many little building centers abandoned because they are devoid of a connection to the electric energy grid and methane piping. Thus, taking inspiration from dove towers, architectural typology widespread in central Italy, a virtual model has been developed as an integrated system for renewable energy production, storage and supply. While recovering the ancient tower, it is possible to design and assembly an integrated intelligent system, able to combine energy supply and demand: a new tower that should be flexible, efficient and replicable in other contexts as manufacturing, commercial and residential ones. The prototype has been applied to a real case of study, an ancient complex located in Umbria Region. The sources for electric production installed on the tower are photovoltaics, on the head and shaft of the tower, hydropower and a biomass gasifier providing thermal too. A tank at the head of the tower allows an available hydraulic potential energy, for the turbine at any time, to cover photovoltaic lacks, caused by sudden loss of production, for environmental causes. Conversely, photovoltaic peaks, otherwise unusable, can be used to reload the water from the receiving tank at the foot of the tower, up to the tank in the head. The same underground tank acts as a thermal flywheel to optimize the geothermal heat pumps for the heat and cold production. Keywords: hydropower, photovoltaics, dove tower.

  2. Fatty acids from VLDL lipolysis products induce lipid droplet accumulation in human monocytes

    PubMed Central

    den Hartigh, Laura J; Connolly-Rohrbach, Jaime E; Fore, Samantha; Huser, Thomas R; Rutledge, John C

    2010-01-01

    One mechanism by which monocytes become activated postprandially is by exposure to triglyceride (TG)-rich lipoproteins such as very low-density lipoproteins (VLDL). VLDL are hydrolyzed by lipoprotein lipase (LpL) at the blood-endothelial cell interface, releasing free fatty acids. In this study, we examined postprandial monocyte activation in more detail, and found that lipolysis products generated from postprandial VLDL induce the formation of lipid-filled droplets within cultured THP-1 monocytes, characterized by coherent anti-stokes Raman spectroscopy. Organelle-specific stains revealed an association of lipid droplets with the endoplasmic reticulum, confirmed by electron microscopy. Lipid droplet formation was reduced when LpL-released fatty acids were bound by bovine serum albumin, which also reduced cellular inflammation. Furthermore, saturated fatty acids induced more lipid droplet formation in monocytes compared to mono- and polyunsaturated fatty acids. Monocytes treated with postprandial VLDL lipolysis products contained lipid droplets with more intense saturated Raman spectroscopic signals than monocytes treated with fasting VLDL lipolysis products. In addition, we found that human monocytes isolated during the peak postprandial period contain more lipid droplets compared to those from the fasting state, signifying that their development is not limited to cultured cells but also occurs in vivo. In summary, circulating free fatty acids can mediate lipid droplet formation in monocytes and potentially be used as a biomarker to assess an individual’s risk of developing atherosclerotic cardiovascular disease. PMID:20208007

  3. Somatic embryogenesis, pigment accumulation, and synthetic seed production in Digitalis davisiana Heywood.

    PubMed

    Verma, Sandeep Kumar; Sahin, Gunce; Gurel, Ekrem

    2016-04-01

    Digitalis davisiana, commonly called Alanya foxglove, from Turkey, is an important medicinal herb as the main source of cardiac glycosides, cardenolides, anthraquinones, etc. It is also known in the Indian Medicine for treatment of wounds and burns. It has ornamental value as well. Overexploitation of D. davisiana has led this species to be declared protected, and thereby encouraged various methods for its propagation. In this study, an optimized and efficient plant tissue culture protocol was established using cotyledonary leaf, hypocotyl and root explants of D. davisiana. Callus tissues were obtained from the cotyledonary leaf, hypocotyl and root segments cultured on Murashige and Skoog's (MS) medium containing different plant growth regulators. The maximum number of somatic embryos were achieved by the MS medium containing 6-benzyladenine (1.0 mg/L BAP) or 2,4-dichlorophenoxy acetic acids (0.1 mg/L 2,4-D), which produced an average of 8.3 ± 1.5 or 5.3 ± 1.5 embryos per cotyledonary leaf, respectively. After 3 wk of culture in MS medium supplemented with 1.0 mg/L 2,4-D, callus showed a clear accumulation of orange pigmentation. Shoot regeneration was remarkably higher (14.3 indirect shoots) in a combination of α-naphthalene acetic acid (0.25 mg/L NAA) plus 3.0 mg/L BAP than 2.0 mg/L zeatin (10.3 ± 0.5 direct shoots) alone. The shoots were successfully rooted on MS medium supplemented with NAA (0.1-1.0 mg/L). In addition, synthetic seeds were produced by encapsulating shoot tips in 4% sodium alginate solution. Maximum conversion frequency of 76.6% was noted from encapsulated shoot tips cultured on 0.25 mg/L NAA with 1.0 mg/L BAP. The encapsulated shoot tips could be stored up to 60 days at 4 °C. Regenerated plantlets of D. davisiana were successfully acclimatized and transferred to soil. This study has demonstrated successful preservation of elite genotypes of D. davisiana. PMID:27295921

  4. Numerical solutions for heat flow in adhesive lap joints

    NASA Technical Reports Server (NTRS)

    Howell, P. A.; Winfree, William P.

    1992-01-01

    The present formulation for the modeling of heat transfer in thin, adhesively bonded lap joints precludes difficulties associated with large aspect ratio grids required by standard FEM formulations. This quasi-static formulation also reduces the problem dimensionality (by one), thereby minimizing computational requirements. The solutions obtained are found to be in good agreement with both analytical solutions and solutions from standard FEM programs. The approach is noted to yield a more accurate representation of heat-flux changes between layers due to a disbond.

  5. Parameter studies on impact in a lap joint

    NASA Astrophysics Data System (ADS)

    Rahmani, Amir M.; Ervin, Elizabeth K.

    2015-03-01

    To represent a loose lap joint, a beam impacting four springs with gaps is modeled. Modal analysis with base excitation is solved, and time histories of contact points are closely monitored. Using the impulse during steady state response, six influential parameters are studied: damping ratio, contact stiffness, intermediate contact position, gap, excitation amplitude and beam height. For all parameters, the system response is highly controlled by modes with two contacting springs. Each parameter's effect on system response is presented including unstable regions, unique trend behaviours result. Recommendations for structural designers are also noted.

  6. Diffusion and accumulation in cultivated vegetable plants of di-(2-ethylhexyl) phthalate (DEHP) from a plastic production factory.

    PubMed

    Du, Q Z; Wang, J W; Fu, X W; Xia, H L

    2010-08-01

    Di-(2-ethylhexyl) phthalate (DEHP) concentrations in the atmosphere and in four vegetable crops including Brassica chinensis L. (bok choy), Brassica campestris L. (field mustard), Vigna unguiculata Walp. (cowpea), and Solanum melongena L. (eggplant) cultivated on land surrounding a plastic production factory were determined. The air DEHP concentrations (means) at the sites 0.2, 0.4, 0.8, and 1.6 km away from the plastic production building were about 9.4-12.8, 5.8-9.6, 1.6-5.0, and 0.04-0.27 microg m(-3) dry weight (DW), respectively. Wind direction is a key factor influencing the measurable DEHP concentration of the air, which was highest in the downwind direction and lowest in the upwind direction, and thus the vegetables accumulated the highest DEHP contents in the downwind direction and the lowest quantities in the upwind direction. The highest DEHP accumulations content of bok choy, field mustard, eggplant, and cowpea were 52.0 +/- 3.1, 43.1 +/- 2.2, 36.2 +/- 2.8, and 19.4 +/- 0.47 mg kg(-1) DW, respectively. Safety estimation on the basis of the daily intake limit referenced by the US Environmental Protection Agency (USEPA) led to the conclusion that eating vegetables cultivated 0.2 km away from the plastic production building is not a food safety problem under normal conditions. A strong positive linear correlation between atmospheric DEHP concentration and DEHP content of the vegetable crops was found. The limits for air DEHP concentration for safe vegetable cultivation are 24.0, 34.8, 40.8, and 82.8 microg m(-3) for bok choy, field mustard, cowpea, and eggplant, respectively, by calculating from the equation of linear regression between air DEHP concentration and vegetable DEHP content. PMID:20496185

  7. Cultivation of Chlorella vulgaris in Column Photobioreactor for Biomass Production and Lipid Accumulation.

    PubMed

    Wong, Y K; Ho, K C; Tsang, Y F; Wang, L; Yung, K K L

    2016-01-01

    Microalgae have been used as energy resources in recent decades to mitigate the global energy crisis. As the demand for pure microalgae strains for commercial use increases, designing an effective photobioreactor (PBR) for mass cultivation is important. Chlorella vulgaris, a local freshwater microalga, was used to study the algal biomass cultivation and lipid production using various PBR configurations (bubbling, air-lift, porous air-lift). The results show that a bubbling column design is a better choice for the cultivation of Chlorella vulgaris than an air-lift one. The highest biomass concentration in the bubbling PBR was 0.78 g/L while the air-lift PBR had a value of 0.09 g/L. Key operating parameters, including draft-tube length and bubbling flowrate, were then optimized based on biomass production and lipid yield. The highest lipid content was in the porous air-lift PBR and the air-lift PBR with shorter draft tube (35 cm) was also better than a longer one (50 cm) for algal cultivation, but the microalgae attachment on the inner tube of PBR always occurred. The highest biomass concentration could be produced under the highest gas flowrate of 2.7 L/min, whereas the lowest dry cell mass was under the lowest gas flowrate of 0.2 L/min. PMID:26803025

  8. Accumulated polymer degradation products as effector molecules in cytotoxicity of polymeric nanoparticles.

    PubMed

    Singh, Raman Preet; Ramarao, Poduri

    2013-11-01

    Polymeric nanoparticles (PNPs) are a promising platform for drug, gene, and vaccine delivery. Although generally regarded as safe, the toxicity of PNPs is not well documented. The present study investigated in vitro toxicity of poly-ε-caprolactone, poly(DL-lactic acid), poly(lactide-cocaprolactone), and poly(lactide-co-glycide) NPs and possible mechanism of toxicity. The concentration-dependent effect of PNPs on cell viability was determined in a macrophage (RAW 264.7), hepatocyte (Hep G2), lung epithelial (A549), kidney epithelial (A498), and neuronal (Neuro 2A) cell lines. PNPs show toxicity at high concentrations in all cell lines. PNPs were efficiently internalized by RAW 264.7 cells and stimulated reactive oxygen species and tumor necrosis factor-alpha production. However, reactive nitrogen species and interleukin-6 production as well as lysosomal and mitochondrial stability remained unaffected. The intracellular degradation of PNPs was determined by monitoring changes in osmolality of culture medium and a novel fluorescence recovery after quenching assay. Cell death showed a good correlation with osmolality of culture medium suggesting the role of increased osmolality in cell death. PMID:23976781

  9. Application of high-content image analysis for quantitatively estimating lipid accumulation in oleaginous yeasts with potential for use in biodiesel production.

    PubMed

    Capus, Aurélie; Monnerat, Marianne; Ribeiro, Luiz Carlos; de Souza, Wanderley; Martins, Juliana Lopes; Sant'Anna, Celso

    2016-03-01

    Biodiesel from oleaginous microorganisms is a viable substitute for a fossil fuel. Current methods for microorganism lipid productivity evaluation do not analyze lipid dynamics in single cells. Here, we described a high-content image analysis (HCA) as a promising strategy for screening oleaginous microorganisms for biodiesel production, while generating single-cell lipid dynamics data in large cell density. Rhodotorula slooffiae yeast were grown in standard (CTL) or lipid trigger medium (LTM), and lipid droplet (LD) accumulation was analyzed in deconvolved confocal microscopy images of cells stained with the lipophilic fluorescent Nile red (NR) dye using automated cell and LD segmentation. The 'vesicle segmentation' method yielded valid morphometric results for limited lipid accumulation in smaller LDs (CTL samples) and for high lipid accumulation in larger LDs (LTM samples), and detected LD localization changes. Thus, HCA can be used to analyze the lipid accumulation patterns likely to be encountered in screens for biodiesel production. PMID:26744805

  10. Lipid accumulation from pinewood pyrolysates by Rhodosporidium diobovatum and Chlorella vulgaris for biodiesel production.

    PubMed

    Luque, Luis; Orr, Valerie C A; Chen, Sean; Westerhof, Roel; Oudenhoven, Stijn; Rossum, Guus van; Kersten, Sascha; Berruti, Franco; Rehmann, Lars

    2016-08-01

    This study evaluated the suitability of pinewood pyrolysates as a carbon source for lipid production and cultivation of the oleaginous yeast Rhodosporidium diobovatum and the microalgae Chlorella vulgaris. Thermal decomposition of pinewood and fractional condensation were used to obtain an oil rich in levoglucosan which was upgraded to glucose by acid hydrolysis. Blending of pyrolytic sugars with pure glucose in both nitrogen rich and nitrogen limited conditions was studied for R. diobovatum, and under nitrogen limited conditions for C. vulgaris. Glucose consumption rate decreased with increasing proportions of pyrolytic sugars increasing cultivation time. While R. diobovatum was capable of growth in 100% (v/v) pyrolytic sugars, C. vulgaris growth declined rapidly in blends greater than 20% (v/v) until no growth was detected in blends >40%. Finally, the effects of pyrolysis sugars on lipid composition was evaluated and biodiesel fuel properties were estimated based on the lipid profiles. PMID:27208736

  11. Calculation of Accumulated Radiation Doses to Man from Radionuclides Found in Food Products and from Radionuclides in the Environment.

    1981-02-17

    PABLM calculates internal radiation doses to man from radionuclides in food products and external radiation doses from radionuclides in the environment. It can be used to calculate accumulated doses to 23 possible body organs or tissues for any one or a combination of radionuclides. Radiation doses from radionuclides in the environment may be calculated from deposition on the soil or plants during an atmospheric or liquid release, or from exposure to residual radionuclides in themore » environment after the releases have ended. Radioactive decay is considered during the release of radionuclides, after they are deposited on the plants or ground, and during holdup of food after harvest. A chain decay scheme is used; it includes branching to account for transitions to and from isomeric states. Doses may be calculated for either a maximum-exposed individual or for a population group. The doses calculated are accumulated doses from continuous chronic exposure. A first-year committed dose is calculated as well as an integrated dose for a selected number of years.« less

  12. Litsea japonica extract inhibits neuronal apoptosis and the accumulation of advanced glycation end products in the diabetic mouse retina

    PubMed Central

    KIM, JUNGHYUN; KIM, CHAN-SIK; LEE, YUN MI; SOHN, EUNJIN; JO, KYUHYUNG; KIM, JIN SOOK

    2015-01-01

    The retinal accumulation of advanced glycation end products (AGEs) is a condition, which is found in diabetic retinopathy. The purpose of the present study was to investigate the protective effect of Litsea japonica extract (LJE) and to elucidate its underlying protective mechanism in model diabetic db/db mice. Male, 7 -week-old db/db mice were treated with LJE (100 or 250 mg/kg body weight) once a day orally for 12 weeks. The expression levels of AGEs and their receptor (RAGE) were subsequently assessed by immunohistochemistry. An electrophoretic mobility shift assay and southwestern histochemistry were used to detect activated nuclear factor κB (NF-κB). The immunohistochemical analysis demonstrated that LJE significantly reduced the expression levels of the AGEs and RAGE in the neural retinas of the db/db mice. LJE markedly inhibited the apop-tosis of retinal ganglion cells. In addition, LJE suppressed the activation of NF-κB. These results suggested that LJE may be beneficial for the treatment of diabetes-induced retinal neurodegeneration, and the ability of LJE to attenuate retinal ganglion cell loss may be mediated by inhibition of the accumulation of AGEs. PMID:25815519

  13. Changing nutrient stoichiometry affects phytoplankton production, DOP accumulation and dinitrogen fixation - a mesocosm experiment in the eastern tropical North Atlantic

    NASA Astrophysics Data System (ADS)

    Meyer, J.; Löscher, C. R.; Neulinger, S. C.; Reichel, A. F.; Loginova, A.; Borchard, C.; Schmitz, R. A.; Hauss, H.; Kiko, R.; Riebesell, U.

    2016-02-01

    Ocean deoxygenation due to climate change may alter redox-sensitive nutrient cycles in the marine environment. The productive eastern tropical North Atlantic (ETNA) upwelling region may be particularly affected when the relatively moderate oxygen minimum zone (OMZ) deoxygenates further and microbially driven nitrogen (N) loss processes are promoted. Consequently, water masses with a low nitrogen to phosphorus (N : P) ratio could reach the euphotic layer, possibly influencing primary production in those waters. Previous mesocosm studies in the oligotrophic Atlantic Ocean identified nitrate availability as a control of primary production, while a possible co-limitation of nitrate and phosphate could not be ruled out. To better understand the impact of changing N : P ratios on primary production and N2 fixation in the ETNA surface ocean, we conducted land-based mesocosm experiments with natural plankton communities and applied a broad range of N : P ratios (2.67-48). Silicic acid was supplied at 15 µmol L-1 in all mesocosms. We monitored nutrient drawdown, biomass accumulation and nitrogen fixation in response to variable nutrient stoichiometry. Our results confirmed nitrate to be the key factor determining primary production. We found that excess phosphate was channeled through particulate organic matter (POP) into the dissolved organic matter (DOP) pool. In mesocosms with low inorganic phosphate availability, DOP was utilized while N2 fixation increased, suggesting a link between those two processes. Interestingly this observation was most pronounced in mesocosms where nitrate was still available, indicating that bioavailable N does not necessarily suppress N2 fixation. We observed a shift from a mixed cyanobacteria-proteobacteria dominated active diazotrophic community towards a diatom-diazotrophic association of the Richelia-Rhizosolenia symbiosis. We hypothesize that a potential change in nutrient stoichiometry in the ETNA might lead to a general shift within

  14. Machine Shop I. Learning Activity Packets (LAPs). Section B--Basic and Related Technology.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains eight learning activity packets (LAPs) for the "basic and related technology" instructional area of a Machine Shop I course. The eight LAPs cover the following topics: basic mathematics, blueprints, rules, micrometer measuring tools, Vernier measuring tools, dial indicators, gaging and inspection tools, and materials and…

  15. Learning Activity Package, Biology 102, (LAP) Studies 1, 3, and 4.

    ERIC Educational Resources Information Center

    Rhoden, Bruce

    Included are three Learning Activity Package (LAP) studies for use in high school biology: Everything has a Place (Grouping and the Diversity of Life), Energy Relations, and Reproduction. Each LAP contains a rationale for teaching the material included, student objectives (stated in behavioral terms), a list of related resources (books,…

  16. Improvement of transformer core magnetic properties using the step-lap design

    NASA Astrophysics Data System (ADS)

    Valkovic, Z.; Rezic, A.

    1992-07-01

    Magnetic properties of the step-lap joints have been investigated experimentally on two three-phase three-leg transformer cores. Using the step-lap joint design, a reduction of the total core loss of 2 to 4.4% and of the exciting power of 31 to 37% has been obtained.

  17. Auto Mechanics I. Learning Activity Packets (LAPs). Section A--Orientation and Safety.

    ERIC Educational Resources Information Center

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains seven learning activity packets (LAPs) that outline the study activities for the orientation and safety instructional area for an Auto Mechanics I course. The seven LAPs cover the following topics: orientation, safety, hand tools, arc welding, oxyacetylene cutting, oxyacetylene fusion welding, and oxyacetylene braze welding.…

  18. Ultrasonic guided wave inspection of Inconel 625 brazed lap joints

    NASA Astrophysics Data System (ADS)

    Comot, Pierre; Bocher, Philippe; Belanger, Pierre

    2016-04-01

    The aerospace industry has been investigating the use of brazing for structural joints, as a mean of reducing cost and weight. There therefore is a need for a rapid, robust, and cost-effective non-destructive testing method for evaluating the structural integrity of the joints. The mechanical strength of brazed joints depends mainly on the amount of brittle phases in their microstructure. Ultrasonic guided waves offer the possibility of detecting brittle phases in joints using spatio-temporal measurements. Moreover, they offer the opportunity to inspect complex shape joints. This study focused on the development of a technique based on ultrasonic guided waves for the inspection of Inconel 625 lap joints brazed with BNi-2 filler metal. A finite element model of a lap joint was used to optimize the inspection parameters and assess the feasibility of detecting the amount of brittle phases in the joint. A finite element parametric study simulating the input signal shape, the center frequency, and the excitation direction was performed. The simulations showed that the ultrasonic guided wave energy transmitted through, and reflected from, the joints was proportional to the amount of brittle phases in the joint.

  19. Lap Shear Testing of Candidate Radiator Panel Adhesives

    NASA Technical Reports Server (NTRS)

    Ellis, David; Briggs, Maxwell; McGowan, Randy

    2013-01-01

    During testing of a subscale radiator section used to develop manufacturing techniques for a full-scale radiator panel, the adhesive bonds between the titanium heat pipes and the aluminum face sheets failed during installation and operation. Analysis revealed that the thermal expansion mismatch between the two metals resulted in relatively large shear stresses being developed even when operating the radiator at moderate temperatures. Lap shear testing of the adhesive used in the original joints demonstrated that the two-part epoxy adhesive fell far short of the strength required. A literature review resulted in several candidate adhesives being selected for lap shear joint testing at room temperature and 398 K, the nominal radiator operating temperature. The results showed that two-part epoxies cured at room and elevated temperatures generally did not perform well. Epoxy film adhesives cured at elevated temperatures, on the other hand, did very well with most being sufficiently strong to cause yielding in the titanium sheet used for the joints. The use of an epoxy primer generally improved the strength of the joint. Based upon these results, a new adhesive was selected for the second subscale radiator section.

  20. Nonlinear Analysis of Bonded Composite Single-LAP Joints

    NASA Technical Reports Server (NTRS)

    Oterkus, E.; Barut, A.; Madenci, E.; Smeltzer, S. S.; Ambur, D. R.

    2004-01-01

    This study presents a semi-analytical solution method to analyze the geometrically nonlinear response of bonded composite single-lap joints with tapered adherend edges under uniaxial tension. The solution method provides the transverse shear and normal stresses in the adhesive and in-plane stress resultants and bending moments in the adherends. The method utilizes the principle of virtual work in conjunction with von Karman s nonlinear plate theory to model the adherends and the shear lag model to represent the kinematics of the thin adhesive layer between the adherends. Furthermore, the method accounts for the bilinear elastic material behavior of the adhesive while maintaining a linear stress-strain relationship in the adherends. In order to account for the stiffness changes due to thickness variation of the adherends along the tapered edges, their in-plane and bending stiffness matrices are varied as a function of thickness along the tapered region. The combination of these complexities results in a system of nonlinear governing equilibrium equations. This approach represents a computationally efficient alternative to finite element method. Comparisons are made with corresponding results obtained from finite-element analysis. The results confirm the validity of the solution method. The numerical results present the effects of taper angle, adherend overlap length, and the bilinear adhesive material on the stress fields in the adherends, as well as the adhesive, of a single-lap joint

  1. Large-Scale Advanced Prop-Fan (LAP)

    NASA Technical Reports Server (NTRS)

    Degeorge, C. L.

    1988-01-01

    In recent years, considerable attention has been directed toward improving aircraft fuel efficiency. Analytical studies and research with wind tunnel models have demonstrated that the high inherent efficiency of low speed turboprop propulsion systems may now be extended to the Mach .8 flight regime of today's commercial airliners. This can be accomplished with a propeller, employing a large number of thin highly swept blades. The term Prop-Fan has been coined to describe such a propulsion system. In 1983 the NASA-Lewis Research Center contracted with Hamilton Standard to design, build and test a near full scale Prop-Fan, designated the Large Scale Advanced Prop-Fan (LAP). This report provides a detailed description of the LAP program. The assumptions and analytical procedures used in the design of Prop-Fan system components are discussed in detail. The manufacturing techniques used in the fabrication of the Prop-Fan are presented. Each of the tests run during the course of the program are also discussed and the major conclusions derived from them stated.

  2. Generic element formulation for modelling bolted lap joints

    NASA Astrophysics Data System (ADS)

    Ahmadian, Hamid; Jalali, Hassan

    2007-07-01

    Joints have significant effects on the dynamic response of the assembled structures due to existence of two non-linear mechanisms in their interface, namely slipping and slapping. These mechanisms affect the structural response by adding considerable damping into the structure and lowering the natural frequencies due to the stiffness softening. Neglecting these effects in modelling of joints produces errors in predictions of the structure responses. In this paper, a non-linear generic element formulation is developed for modelling bolted lap joints. The generic element is formed by satisfying all conditions that are known for a joint interface and hence providing a non-linear parametric formulation for the families of allowable joint models. Dynamic response of the developed model for the assembled structure including the generic joint interface element is obtained using the incremental harmonic balance (IHB) method. The generic parameters of the joint are identified by minimising the difference between the model response obtained from IHB method and the observed behaviour of the structure. The procedure is demonstrated by modelling an actual structure containing a single lap bolted joint in the middle. The frequency responses of the structure around the first two resonance frequencies are measured by exciting the structure using a sinusoidal force at each individual frequency. The measured responses are compared with the predictions of the model containing a parametric generic joint element. The parameters of the joint interface model are successfully identified by minimising the difference between the measured responses and the model predictions.

  3. Edge effect modeling and experiments on active lap processing.

    PubMed

    Liu, Haitao; Wu, Fan; Zeng, Zhige; Fan, Bin; Wan, Yongjian

    2014-05-01

    Edge effect is regarded as one of the most difficult technical issues for fabricating large primary mirrors, especially for large polishing tools. Computer controlled active lap (CCAL) uses a large size pad (e.g., 1/3 to 1/5 workpiece diameters) to grind and polish the primary mirror. Edge effect also exists in the CCAL process in our previous fabrication. In this paper the material removal rules when edge effects happen (i.e. edge tool influence functions (TIFs)) are obtained through experiments, which are carried out on a Φ1090-mm circular flat mirror with a 375-mm-diameter lap. Two methods are proposed to model the edge TIFs for CCAL. One is adopting the pressure distribution which is calculated based on the finite element analysis method. The other is building up a parametric equivalent pressure model to fit the removed material curve directly. Experimental results show that these two methods both effectively model the edge TIF of CCAL. PMID:24921777

  4. Atomic physics and synchrotron radiation: The production and accumulation of highly charged ions

    NASA Astrophysics Data System (ADS)

    Johnson, B. M.; Meron, M.; Agagu, A.; Jones, K. W.

    1987-04-01

    Synchrotron radiation can be used to produce highly-charged ions, and to study photoexcitation and photoionization for ions of virtually any element in the periodic table. To date, with few exceptions, atomic physics studies have been limited to rare gases and a few metal vapors, and to photoexcitation energies in the VUV region of the electromagnetic spectrum. These limitations can now be overcome using photons produced by high-brightness synchrotron storage rings, such as the X-ray ring at the National Synchrotron Light Source (NSLS) at Brookhaven. Furthermore, calculations indicate that irradiation of an ion trap with an intense energetic photon beam will result in a viable source of highly-charged ions that can be given the name PHOBIS: the photon beam ion source. Promising results, which encourage the wider systematic use of synchrotron radiation in atomic physics research, have been obtained in recent experiments on VUV photoemission and the production and storage of multiply-charged ions. An overview of the field, current plans, and future possibilities will be presented.

  5. Accumulative charge separation for solar fuels production: coupling light-induced single electron transfer to multielectron catalysis.

    PubMed

    Hammarström, Leif

    2015-03-17

    The conversion and storage of solar energy into a fuel holds promise to provide a significant part of the future renewable energy demand of our societies. Solar energy technologies today generate heat or electricity, while the large majority of our energy is used in the form of fuels. Direct conversion of solar energy to a fuel would satisfy our needs for storable energy on a large scale. Solar fuels can be generated by absorbing light and converting its energy to chemical energy by electron transfer leading to separation of electrons and holes. The electrons are used in the catalytic reduction of a cheap substrate with low energy content into a high-energy fuel. The holes are filled by oxidation of water, which is the only electron source available for large scale solar fuel production. Absorption of a single photon typically leads to separation of a single electron-hole pair. In contrast, fuel production and water oxidation are multielectron, multiproton reactions. Therefore, a system for direct solar fuel production must be able to accumulate the electrons and holes provided by the sequential absorption of several photons in order to complete the catalytic reactions. In this Account, the process is termed accumulative charge separation. This is considerably more complicated than charge separation on a single electron level and needs particular attention. Semiconductor materials and molecular dyes have for a long time been optimized for use in photovoltaic devices. Efforts are made to develop new systems for light harvesting and charge separation that are better optimized for solar fuel production than those used in the early devices presented so far. Significant progress has recently been made in the discovery and design of better homogeneous and heterogeneous catalysts for solar fuels and water oxidation. While the heterogeneous ones perform better today, molecular catalysts based on transition metal complexes offer much greater tunability of electronic and

  6. Comparative study of flavonoid production in lycopene-accumulated and blonde-flesh sweet oranges (Citrus sinensis) during fruit development.

    PubMed

    Chen, Jiajing; Zhang, Hongyan; Pang, Yibo; Cheng, Yunjiang; Deng, Xiuxin; Xu, Juan

    2015-10-01

    Four main flavanone glycosides (FGs) and four main polymethoxylated flavones (PMFs) were determined in fruits of 'Cara Cara' navel orange, 'Seike' navel orange, 'Anliu' and 'Honganliu' sweet orange (Citrus sinensis). No bitter neohesperidosides were detected in the FG profiles, indicating the functional inability of 1,2-rhamnosyltransferase, though relatively high transcription levels were detected in the fruit tissues of 'Anliu' and 'Honganliu' sweet oranges. Different to the FGs, the PMFs only exist abundantly in the peel and decreased gradually throughout fruit development of sweet oranges, suggesting the expression of methylation-related genes accounting for PMF biosynthesis have tissue-specificity. Significant changes in production of the eight flavonoids were found between red-flesh and blonde-flesh sweet oranges, indicating that lycopene accumulation might have direct or indirect effects on the modification of flavonoid biosynthesis in these citrus fruits. PMID:25872450

  7. Melanin targets LC3-associated phagocytosis (LAP): A novel pathogenetic mechanism in fungal disease.

    PubMed

    Chamilos, Georgios; Akoumianaki, Tonia; Kyrmizi, Irene; Brakhage, Axel; Beauvais, Anne; Latge, Jean-Paul

    2016-05-01

    Intracellular swelling of conidia of the major human airborne fungal pathogen Aspergillus fumigatus results in surface exposure of immunostimulatory pathogen-associated molecular patterns (PAMPs) and triggers activation of a specialized autophagy pathway called LC3-associated phagocytosis (LAP) to promote fungal killing. We have recently discovered that, apart from PAMPs exposure, cell wall melanin removal during germination of A. fumigatus is a prerequisite for activation of LAP. Importantly, melanin promotes fungal pathogenicity via targeting LAP, as a melanin-deficient A. fumigatus mutant restores its virulence upon conditional inactivation of Atg5 in hematopoietic cells of mice. Mechanistically, fungal cell wall melanin selectively excludes the CYBA/p22phox subunit of NADPH oxidase from the phagosome to inhibit LAP, without interfering with signaling regulating cytokine responses. Notably, inhibition of LAP is a general property of melanin pigments, a finding with broad physiological implications. PMID:27028978

  8. PGE2-Induced CXCL12 Production and CXCR4 Expression Controls the Accumulation of Human MDSCs in Ovarian Cancer Environment

    PubMed Central

    Obermajer, Nataša; Muthuswamy, Ravikumar; Odunsi, Kunle; Edwards, Robert P.; Kalinski, Pawel

    2016-01-01

    Signals mediated by CXCL12 (SDF1) and its receptor CXCR4 are centrally involved in cancer progression, both directly by activating cancer cells and indirectly by inducing angiogenesis plus recruiting T regulatory and plasmacytoid dendritic immune cells. Here, we show that in ascites isolated from ovarian cancer patients, both CXCL12 and CXCR4 are controlled by the tumor-associated inflammatory mediator prostaglandin E2 (PGE2), which attracts myeloid-derived suppressor cells (MDSC) into the ascites microenvironment. In this setting, PGE2 was essential both for expression of functional CXCR4 in cancer-associated MDSCs and for production of its ligand CXCL12. Frequencies of CD11b+CD14+CD33+CXCR4+ MDSCs closely correlated with CXCL12 and PGE2 levels in patient ascites. MDSCs migrated toward ovarian cancer ascites in a CXCR4-dependent manner that required COX2 activity and autocrine PGE2 production. Inhibition of COX2 or the PGE2 receptors EP2/EP4 in MDSCs suppressed expression of CXCR4 and MDSC responsiveness to CXCL12 or ovarian cancer ascites. Similarly, COX2 inhibition also blocked CXCL12 production in the ovarian cancer environment and its ability to attract MDSCs. Together, our findings elucidate a central role for PGE2 in MDSC accumulation triggered by the CXCL12-CXCR4 pathway, providing a powerful rationale to target PGE2 signaling in ovarian cancer therapy. PMID:22025564

  9. The Teacher's Lap--A Site of Emotional Well-Being for the Younger Children in Day-Care Groups

    ERIC Educational Resources Information Center

    Hännikäinen, Maritta

    2015-01-01

    This study focuses on a particular relationship between teachers and one- to three-year-old children: the child in the teacher's lap. When, in what situations, does this happen? Who are the children in the teacher's lap? Why are they there? How do children express emotional well-being when in the teacher's lap? Relational, sociocultural and…

  10. Dechlorination of Chloral Hydrate Is Influenced by the Biofilm Adhesin Protein LapA in Pseudomonas putida LF54

    PubMed Central

    Zhang, Wanjun; Huhe; Pan, Yuanbai; Toyofuku, Masanori; Nomura, Nobuhiko; Nakajima, Toshiaki

    2013-01-01

    LapA is the largest surface adhesion protein of Pseudomonas putida that initiates biofilm formation. Here, by using transposon insertion mutagenesis and a conditional lapA mutant, we demonstrate for the first time that LapA influences chloral hydrate (CH) dechlorination in P. putida LF54. PMID:23603683

  11. Accumulation of soil carbon drives denitrification potential and lab-incubated gas production along a chronosequence of salt marsh development

    NASA Astrophysics Data System (ADS)

    He, Yanlong; Widney, Sarah; Ruan, Michelle; Herbert, Ellen; Li, Xiuzhen; Craft, Christopher

    2016-04-01

    We measured sediment organic carbon and nitrogen accumulation and rates of denitrification enzyme activity and greenhouse gas (CO2, CH4, N2O) production from slurries of sediments of a mudflat that formed in 2002, a young (8-year-old) natural Spartina alterniflora salt marsh that developed on part of the mudflat, and four mature (>200 years old) salt marshes in southeastern Georgia to examine microbial processes related to carbon (C) and nitrogen (N) cycling during succession from mudflat to mature marsh. Soil organic C and N and C: N ratio (0-30 cm) increased across the chronosequence from mudflat (791 ± 35 g C/m2, 125 ± 17 g N/m2) to young marsh (2520 ± 131 g C/m2, 190 ± 10 g N/m2) to mature marshes (5827 ± 250 g C/m2, 372 ± 20 g N/m2). After 8 years of colonization by S. alterniflora, sediment organic carbon increased 3.2 times, and nitrogen increased 1.5 times relative to the mudflat. The high rate of organic C and N accumulation based on time series measurements (188 g C/m2/yr, 7.8 g N/m2/yr) and feldspar marker layers (359 g C/m2/yr, 26.2 g N/m2/yr) was attributed to high accretion (3 cm/yr) in this low elevation (0.18 m NAVD88) emerging marsh. Carbon dioxide production increased with increasing sediment organic C from mudflat to mature marshes. Un-amended denitrification enzyme activity, measured in slurry incubations, ranged from an average of 0.020 ± 0.005 μg g-1 hr-1 in the mature marshes to 0.094 ± 0.03 μg g-1 hr-1 in the young marsh. We also measured denitrification potential in slurry incubations amended with C (glucose), N (nitrate), and C + N to assess the potential for substrate limitations. Denitrification potential in the mudflat did not show strong nutrient limitation. In the young marsh, denitrification potential was C-limited, and in the mature marsh, it was co-limited by C and N. In July samples, CO2 production showed a statistically significant increase with age from the mudflat to the mature marshes. However, in both months, CO2

  12. C/EBPβ-LAP*/LAP Expression Is Mediated by RSK/eIF4B-Dependent Signalling and Boosted by Increased Protein Stability in Models of Monocytic Differentiation

    PubMed Central

    Christmann, Martin; Friesenhagen, Judith; Westphal, Andreas; Pietsch, Daniel; Brand, Korbinian

    2015-01-01

    The transcription factor C/EBPβ plays a key role in monocytic differentiation and inflammation. Its small isoform LIP is associated with proliferation at early premonocytic developmental stages and regulated via mTOR-dependent signalling. During later stages of (pre)monocytic differentiation there is a considerable increase in the large C/EBPβ isoforms LAP*/LAP which inhibit proliferation thus supporting terminal differentiation. Here, we showed in different models of monocytic differentiation that this dramatic increase in the LAP*/LAP protein and LAP/LIP ratio was accompanied by an only modest/retarded mRNA increase suggesting an important role for (post)translational mechanisms. We found that LAP*/LAP formation was induced via MEK/RSK-dependent cascades, whereas mTOR/S6K1 were not involved. Remarkably, LAP*/LAP expression was dependent on phosphorylated eIF4B, an acceleratory protein of RNA helicase eIF4A. PKR inhibition reduced the expression of eIF4B and C/EBPβ in an eIF2α-independent manner. Furthermore, under our conditions a marked stabilisation of LAP*/LAP protein occurred, accompanied by reduced chymotrypsin-like proteasome/calpain activities and increased calpastatin levels. Our study elucidates new signalling pathways inducing LAP*/LAP expression and indicates new alternative PKR functions in monocytes. The switch from mTOR- to RSK-mediated signalling to orchestrate eIF4B-dependent LAP*/LAP translation, accompanied by increased protein stability but only small mRNA changes, may be a prototypical example for the regulation of protein expression during selected processes of differentiation/proliferation. PMID:26646662

  13. Weed management, training, and irrigation practices for organic production of trailing blackberry: III. Accumulation and removal of aboveground biomass, carbon, and nutrients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of various production practices on biomass, C, and nutrient content, accumulation, and loss were assessed over 2 years in a mature organic trailing blackberry (Rubus L. subgenus Rubus, Watson) production system. Treatments included two irrigation options (no irrigation after harvest and ...

  14. Accumulate-Repeat-Accumulate-Accumulate-Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Sam; Thorpe, Jeremy

    2004-01-01

    Inspired by recently proposed Accumulate-Repeat-Accumulate (ARA) codes [15], in this paper we propose a channel coding scheme called Accumulate-Repeat-Accumulate-Accumulate (ARAA) codes. These codes can be seen as serial turbo-like codes or as a subclass of Low Density Parity Check (LDPC) codes, and they have a projected graph or protograph representation; this allows for a high-speed iterative decoder implementation using belief propagation. An ARAA code can be viewed as a precoded Repeat-and-Accumulate (RA) code with puncturing in concatenation with another accumulator, where simply an accumulator is chosen as the precoder; thus ARAA codes have a very fast encoder structure. Using density evolution on their associated protographs, we find examples of rate-lJ2 ARAA codes with maximum variable node degree 4 for which a minimum bit-SNR as low as 0.21 dB from the channel capacity limit can be achieved as the block size goes to infinity. Such a low threshold cannot be achieved by RA or Irregular RA (IRA) or unstructured irregular LDPC codes with the same constraint on the maximum variable node degree. Furthermore by puncturing the accumulators we can construct families of higher rate ARAA codes with thresholds that stay close to their respective channel capacity thresholds uniformly. Iterative decoding simulation results show comparable performance with the best-known LDPC codes but with very low error floor even at moderate block sizes.

  15. An examination of faying surface fretting in single lap splices

    NASA Astrophysics Data System (ADS)

    Brown, Adam

    While fretting damage in mechanically fastened joints is widely acknowledged as a common source of crack nucleation, little work is available in the open literature on the role that fretting damage plays in the fatigue life of a riveted joint. To expand on the limited knowledge available, a study was undertaken on fretting fatigue in thin-sheet riveted fuselage lap joints. In joints constructed out of 1 mm thick 2024-T3 aluminum sheet the rivet forming load was found to have a significant effect on the location of fretting damage and crack nucleation. This effect was observed for splices riveted with machine countersunk and with universal rivets. The shift in the location of peak fretting damage and crack nucleation with changing rivet forming loads was investigated through numerical and experimental methods. A predictive model based on the critical plane Smith-Watson-Topper strain life equation was applied to the complex geometry of the single lap splice and was shown to be effective in predicting the fretting fatigue life as well as the location of fretting-induced crack nucleation. Basing this model on an explicit finite element simulation allowed for the inclusion of compressive residual stresses generated during rivet forming. Key to the proper functionality of the predictive model was to have a validated finite element model from which results for the stress and strain field in the loaded component could be obtained. In addition to the predictive model, a series of splice coupon and simplified geometry fretting fatigue tests were performed. The tests showed that, at higher rivet forming loads, crack nucleation is on the faying surface away from the hole edge and that the type of surface condition is important to the fretting fatigue life of the splice. The discovery of this variation with surface treatment at high rivet forming loads is important as more research is showing the benefit of using load-controlled rivet forming and higher rivet forming loads in

  16. Macrophage migration inhibitory factor drives neutrophil accumulation by facilitating IL-1β production in a murine model of acute gout.

    PubMed

    Galvão, Izabela; Dias, Ana Carolina Fialho; Tavares, Livia Duarte; Rodrigues, Irla Paula Stopa; Queiroz-Junior, Celso Martins; Costa, Vivian Vasconcelos; Reis, Alesandra Corte; Ribeiro Oliveira, Rene Donizeti; Louzada-Junior, Paulo; Souza, Daniele Glória; Leng, Lin; Bucala, Richard; Sousa, Lirlândia Pires; Bozza, Marcelo Torres; Teixeira, Mauro Martins; Amaral, Flávio Almeida

    2016-06-01

    This study evaluated the role of macrophage migration inhibitory factor in inflammation caused by monosodium urate crystals. The concentration of macrophage migration inhibitory factor was increased in synovial fluid of patients with acute gout, and there was a positive correlation between intra-articular macrophage migration inhibitory factor and IL-1β concentrations. In mice, the injection of monosodium urate crystals into the knee joint increased the levels of macrophage migration inhibitory factor in macrophages and in inflamed tissue. The injection of recombinant macrophage migration inhibitory factor into the joint of mice reproduced the inflammatory response observed in acute gout, including histologic changes, the recruitment of neutrophils, and increased levels of IL-1β and CXCL1. Importantly, the accumulation of neutrophils and the amount IL-1β in the joints were reduced in macrophage migration inhibitory factor-deficient mice when injected with monosodium urate crystals. We observed a similar effect when we blocked macrophage migration inhibitory factor with (S,R)-3-(4-hydroxyphenyl)-4,5-dihydro-5-isoxazole acetic acid or anti-macrophage migration inhibitory factor. In addition, the blockade of IL-1R and CXCR2 reduced recombinant macrophage migration inhibitory factor-induced neutrophil recruitment. Mechanistically, recombinant macrophage migration inhibitory factor is important for the synthesis of il1β mRNA in vivo and in isolated macrophages. Altogether, macrophage migration inhibitory factor promotes neutrophil accumulation and is important for IL-1β production, which are 2 crucial events contributing to the pathogenesis of acute gout. PMID:26868525

  17. Testing composite-to-metal tubular lap joints

    NASA Astrophysics Data System (ADS)

    Guess, T. R.; Reedy, E. D., Jr.; Slavin, A. M.

    Procedures were developed to fabricate, nondestructively evaluate, and mechanically test composite-to-metal tubular joints. The axially loaded tubular lap joint specimen consisted of two metal tubes bonded within each end of a fiberglass composite tube. Joint specimens with both tapered and untapered aluminum adherends and a plain weave E-glass/epoxy composite were tested in tension, compression, and flexure. Other specimens with tapered and untapered steel adherends and a triaxially reinforced E-glass/epoxy composite were tested in tension and compression. Test results include joint strength and failure mode data. A finite element analysis of the axially loaded joints explains the effect of adherend geometry and material properties on measured joint strength. The flexural specimen was also analyzed; calculated surface strains are in good agreement with measured values, and joint failure occurs in the region of calculated peak peel stress.

  18. Large-Scale Advanced Prop-Fan (LAP) blade design

    NASA Technical Reports Server (NTRS)

    Violette, John A.; Sullivan, William E.; Turnberg, Jay E.

    1984-01-01

    This report covers the design analysis of a very thin, highly swept, propeller blade to be used in the Large-Scale Advanced Prop-Fan (LAP) test program. The report includes: design requirements and goals, a description of the blade configuration which meets requirements, a description of the analytical methods utilized/developed to demonstrate compliance with the requirements, and the results of these analyses. The methods described include: finite element modeling, predicted aerodynamic loads and their application to the blade, steady state and vibratory response analyses, blade resonant frequencies and mode shapes, bird impact analysis, and predictions of stalled and unstalled flutter phenomena. Summarized results include deflections, retention loads, stress/strength comparisons, foreign object damage resistance, resonant frequencies and critical speed margins, resonant vibratory mode shapes, calculated boundaries of stalled and unstalled flutter, and aerodynamic and acoustic performance calculations.

  19. Testing composite-to-metal tubular lap joints

    SciTech Connect

    Guess, T.R.; Reedy, E.D. Jr.; Slavin, A.M.

    1993-11-01

    Procedures were developed to fabricate, nondestructively evaluate, and mechanically test composite-to-metal tubular joints. The axially loaded tubular lap joint specimen consisted of two metal tubes bonded within each end of a fiberglass composite tube. Joint specimens with both tapered and untapered aluminum adherends and a plain weave E-glass/epoxy composite were tested in tension, compression, and flexure. Other specimens with tapered and untapered steel adherends and a triaxially reinforced E-glass/epoxy composite were tested in tension and compression. Test results include joint strength and failure mode data. A finite element analysis of the axially loaded joints explains the effect of adherend geometry and material properties on measured joint strength. The flexural specimen was also analyzed; calculated surface strains are in good agreement with measured values, and joint failure occurs in the region of calculated peak peel stress.

  20. Deformations and strains in a thick adherend lap joint

    NASA Technical Reports Server (NTRS)

    Post, D.; Czarnek, R.; Wood, J. D.; Joh, D.

    1988-01-01

    Displacement fields in a thick adherend lap joint were measured by high-sensitivity moire interferometry. Contour maps of in-plane U and V displacements were obtained across adhesive and adherend surfaces. Loads ranged from a modest load to a near-failure load. Quantitative results are given for displacements and strains in the adhesive and along the adhesive/adherend boundary lines. The results show nearly constant shear strain in the adhesive, nonlinear strains as a function of load or average shear stress, and viscoelastic or time-dependent response. Longitudinal normal strains in the adhesive are nearly two orders of magnitude less than the shear strains. With its subwavelength displacement resolution and high spatial resolution, moire interferometry is especially well suited for deformation studies of adhesive joints.

  1. Accumulate-Repeat-Accumulate-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Samuel; Thorpe, Jeremy

    2007-01-01

    Accumulate-repeat-accumulate-accumulate (ARAA) codes have been proposed, inspired by the recently proposed accumulate-repeat-accumulate (ARA) codes. These are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. ARAA codes can be regarded as serial turbolike codes or as a subclass of low-density parity-check (LDPC) codes, and, like ARA codes they have projected graph or protograph representations; these characteristics make it possible to design high-speed iterative decoders that utilize belief-propagation algorithms. The objective in proposing ARAA codes as a subclass of ARA codes was to enhance the error-floor performance of ARA codes while maintaining simple encoding structures and low maximum variable node degree.

  2. Lamina Associated Polypeptide 1 (LAP1) Interactome and Its Functional Features

    PubMed Central

    Serrano, Joana B.; da Cruz e Silva, Odete A. B.; Rebelo, Sandra

    2016-01-01

    Lamina-associated polypeptide 1 (LAP1) is a type II transmembrane protein of the inner nuclear membrane encoded by the human gene TOR1AIP1. LAP1 is involved in maintaining the nuclear envelope structure and appears be involved in the positioning of lamins and chromatin. To date, LAP1’s precise function has not been fully elucidated but analysis of its interacting proteins will permit unraveling putative associations to specific cellular pathways and cellular processes. By assessing public databases it was possible to identify the LAP1 interactome, and this was curated. In total, 41 interactions were identified. Several functionally relevant proteins, such as TRF2, TERF2IP, RIF1, ATM, MAD2L1 and MAD2L1BP were identified and these support the putative functions proposed for LAP1. Furthermore, by making use of the Ingenuity Pathways Analysis tool and submitting the LAP1 interactors, the top two canonical pathways were “Telomerase signalling” and “Telomere Extension by Telomerase” and the top functions “Cell Morphology”, “Cellular Assembly and Organization” and “DNA Replication, Recombination, and Repair”. Once again, putative LAP1 functions are reinforced but novel functions are emerging. PMID:26784240

  3. Alleviation of harmful effect in stillage reflux in food waste ethanol fermentation based on metabolic and side-product accumulation regulation.

    PubMed

    Ma, Hongzhi; Yang, Jian; Jia, Yan; Wang, Qunhui; Ma, Xiaoyu; Sonomoto, Kenji

    2016-10-01

    Stillage reflux fermentation in food waste ethanol fermentation could reduce sewage discharge but exert a harmful effect because of side-product accumulation. In this study, regulation methods based on metabolic regulation and side-product alleviation were conducted. Result demonstrated that controlling the proper oxidation-reduction potential value (-150mV to -250mV) could reduce the harmful effect, improve ethanol yield by 21%, and reduce fermentation time by 20%. The methods of adding calcium carbonate to adjust the accumulated lactic acid showed that ethanol yield increased by 17.3%, and fermentation time decreased by 20%. The accumulated glyceal also shows that these two methods can reduce the harmful effect. Fermentation time lasted for seven times without effect, and metabolic regulation had a better effect than side-product regulation. PMID:27394991

  4. Influence of environmental parameters on production of the acrolein precursor 3-hydroxypropionaldehyde by Lactobacillus reuteri DSMZ 20016 and its accumulation by wine lactobacilli.

    PubMed

    Bauer, Rolene; du Toit, Maret; Kossmann, Jens

    2010-01-31

    Lactic acid bacteria belonging to the genus Lactobacillus are known to convert glycerol into 3-hydroxypropionaldehyde (3-HPA) during anaerobic glycerol fermentation. Wine quality can be gravely compromised by the accumulation of 3-HPA, due to its spontaneous conversion to acrolein under wine making conditions. Acrolein is not only a dangerous substance for the living cell, but has been implicated in the development of unpleasant bitterness in beverages. This study evaluates the effect of individual environmental parameters on 3-HPA production by Lactobacillus reuteri DSMZ 20016, which only proved possible under conditions that allow accumulation well below the threshold concentration affecting cell viability. 3-HPA production was optimal at pH 6 and in the presence of 300 mM glycerol. Production increased with an increase in cell concentration up to an OD(600) of 50, whereas higher cell concentrations inhibited accumulation. Data presented in this study suggest that 3-HPA plays a role in regulating its own production through quorum sensing. Glycerol dehydratase possessing bacterial strains isolated from South African red wine, L. pentosus and L. brevis, tested positive for 3-HPA accumulation. 3-HPA is normally intracellularly reduced to 1,3-propanediol. This is the first study demonstrating the ability of wine lactobacilli to accumulate 3-HPA in the fermentation media. Recommendations are made on preventing the formation of acrolein and its precursor 3-HPA in wine. PMID:19897270

  5. Use of two-dimensional transmission photoelastic models to study stresses in double-lap bolted joints

    NASA Technical Reports Server (NTRS)

    Hyer, M. W.; Liu, D. H.

    1981-01-01

    The stress distribution in two hole connectors in a double lap joint configuration was studied. The following steps are described: (1) fabrication of photoelastic models of double lap double hole joints designed to determine the stresses in the inner lap; (2) assessment of the effects of joint geometry on the stresses in the inner lap; and (3) quantification of differences in the stresses near the two holes. The two holes were on the centerline of the joint and the joints were loaded in tension, parallel to the centerline. Acrylic slip fit pins through the holes served as fasteners. Two dimensional transmission photoelastic models were fabricated by using transparent acrylic outer laps and a photoelastic model material for the inner laps. It is concluded that the photoelastic fringe patterns which are visible when the models are loaded are due almost entirely to stresses in the inner lap.

  6. Global-Local Finite Element Analysis of Bonded Single-Lap Joints

    NASA Technical Reports Server (NTRS)

    Kilic, Bahattin; Madenci, Erdogan; Ambur, Damodar R.

    2004-01-01

    Adhesively bonded lap joints involve dissimilar material junctions and sharp changes in geometry, possibly leading to premature failure. Although the finite element method is well suited to model the bonded lap joints, traditional finite elements are incapable of correctly resolving the stress state at junctions of dissimilar materials because of the unbounded nature of the stresses. In order to facilitate the use of bonded lap joints in future structures, this study presents a finite element technique utilizing a global (special) element coupled with traditional elements. The global element includes the singular behavior at the junction of dissimilar materials with or without traction-free surfaces.

  7. Electromechanical behaviour of REBCO tape lap splices under transverse compressive loading

    NASA Astrophysics Data System (ADS)

    Grether, A.; Scheuerlein, C.; Ballarino, A.; Bottura, L.

    2016-07-01

    We have studied the influence of transverse compressive stress on the resistance and critical current (I c ) of soldered REBCO tape lap splices. Internal contact resistances dominate the overall REBCO lap splice resistances. Application of transverse compressive stress up to 250 MPa during the resistance measurements does not alter the resistance and I c of the soldered REBCO splices that were studied. The resistance of unsoldered REBCO tape lap splices depends strongly on the contact pressure. At a transverse compressive stress of 100 MPa, to which Roebel cables are typically exposed in high field magnets, the crossover splice contact resistance is comparable to the internal tape resistances.

  8. Machine imparting complex rotary motion for lapping a spherical inner diameter

    DOEpatents

    Carroll, T.A.; Yetter, H.H.

    1985-01-30

    An apparatus for imparting complex rotary motion is used to lap an inner spherical diameter surface of a workpiece. A lapping tool consists of a dome and rod mounted along the dome's vertical axis. The workpiece containing the lapping tool is held in a gimbal which uses power derived from a secondary takeoff means to impart rotary motion about a horizontal axis. The gimbal is rotated about a vertical axis by a take means while mounted at a radially outward position on a rotating arm.

  9. Machine imparting complex rotary motion for lapping a spherical inner diameter

    DOEpatents

    Carroll, Thomas A.; Yetter, Harold H.

    1986-01-01

    An apparatus for imparting complex rotary motion is used to lap an inner spherical diameter surface of a workpiece. A lapping tool consists of a dome and rod mounted along the dome's vertical axis. The workpiece containing the lapping tool is held in a gimbal which uses power derived from a secondary takeoff means to impart rotary motion about a horizontal axis. The gimbal is rotated about a vertical axis by a take means while mounted at a radially outward position on a rotating arm.

  10. Expression of a bacterial mtlD gene in transgenic tobacco leads to production and accumulation of mannitol.

    PubMed Central

    Tarczynski, M C; Jensen, R G; Bohnert, H J

    1992-01-01

    A bacterial gene encoding mannitol-1-phosphate dehydrogenase, mtlD, was engineered for expression in higher plants. Gene constructions were stably incorporated into tobacco plants. The mtlD gene was expressed and translated into a functional enzyme in tobacco, resulting in the synthesis and accumulation of mannitol, which was identified by NMR and mass spectroscopy. Mannitol concentrations exceeded 6 mumol/g (fresh weight) in the leaves and in the roots of some transformants, whereas this sugar alcohol was not detected in these organs of wild-type tobacco plants or of untransformed tobacco plants that underwent the same regeneration scheme. These experiments demonstrate that branch-points in plant carbohydrate metabolism can be generated by which novel gene products can utilize endogenous substrates to divert metabolic energy into novel compounds. Additionally, the system described here allows for physiological studies in which the responses of wild-type and transgenic tobacco to various environmental stimuli can be compared directly. Such studies will facilitate our understanding of the roles of sugar alcohols (e.g., in stress tolerance) in higher plants. Images PMID:1557364

  11. Accumulation of radioactive corrosion products on steel surfaces of VVER-type nuclear reactors. II. 60Co

    NASA Astrophysics Data System (ADS)

    Varga, Kálmán; Hirschberg, Gábor; Németh, Zoltán; Myburg, Gerrit; Schunk, János; Tilky, Péter

    2001-10-01

    In the case of intact fuel claddings, the predominant source of radioactivity in the primary circuits of water-cooled nuclear reactors is the activation of corrosion products in the core. The most important corrosion product radionuclides in the primary coolant of pressurized water reactors (PWRs) are 60Co, 58Co, 51Cr, 54Mn, 59Fe (as well as 110mAg in some Soviet-made VVER-type reactor). The second part of this series is focused on the complex studies of the formation and build-up of 60Co-containing species on an austenitic stainless steel type 08X18H10T (GOST 5632-61) and magnetite-covered carbon steel often to be used in Soviet-planned VVERs. The kinetics and mechanism of the cobalt accumulation were studied by a combination (coupling) of an in situ radiotracer method and voltammetry in a model solution of the primary circuit coolant. In addition, independent techniques such as X-ray photoelectron spectroscopic (XPS) and ICP-OES are also used to analyze the chemical state of Co species in the passive layer formed on stainless steel as well as the chemical composition of model solution. The experimental results have revealed that: (i) The passive behavior of the austenitic stainless steel at open-circuit conditions, the slightly alkaline pH and the reducing water chemistry can be considered to be optimal to minimize the 60Co contamination. (ii) The highly potential dependent deposition of various Co-oxides at E>1.10 V (vs. RHE) offers a unique possibility to elaborate a novel electrochemical method for the decrease or removal of cobalt traces from borate-containing coolants contaminated with 60Co and/or 58Co radionuclides.

  12. Roles of Cyclic Di-GMP and the Gac System in Transcriptional Control of the Genes Coding for the Pseudomonas putida Adhesins LapA and LapF

    PubMed Central

    Martínez-Gil, Marta; Ramos-González, María Isabel

    2014-01-01

    LapA and LapF are large extracellular proteins that play a relevant role in biofilm formation by Pseudomonas putida. Current evidence favors a sequential model in which LapA is first required for the initial adhesion of individual bacteria to a surface, while LapF participates in later stages of biofilm development. In agreement with this model, lapF transcription was previously shown to take place at late times of growth and to respond to the stationary-phase sigma factor RpoS. We have now analyzed the transcription pattern of lapA and other regulatory elements that influence expression of both genes. The lapA promoter shows a transient peak of activation early during growth, with a second increase in stationary phase that is independent of RpoS. The same pattern is observed in biofilms although expression is not uniform in the population. Both lapA and lapF are under the control of the two-component regulatory system GacS/GacA, and their transcription also responds to the intracellular levels of the second messenger cyclic diguanylate (c-di-GMP), although in surprisingly reverse ways. Whereas expression from the lapA promoter increases with high levels of c-di-GMP, the opposite is true for lapF. The transcriptional regulator FleQ is required for the modulation of lapA expression by c-di-GMP but has a minor influence on lapF. This work represents a further step in our understanding of the regulatory interactions controlling biofilm formation in P. putida. PMID:24488315

  13. Alteration of Sulphides in the Rumuruti Chondrite La Paz Icefield (LAP) 031275

    NASA Astrophysics Data System (ADS)

    Steer, E. D.; Treiman, A. H.

    2014-09-01

    Pyrrhotite in LAP 03175 (R5) has altered to a fine-grained mineral mixture. New data (optical, chemical, and Raman) suggest the mixture includes violarite and tochilinite, but not (as suggested earlier) graphite, hematite, and/or jarosite.

  14. Energy release, beam attenuation radiation damage, gas production and accumulation of long-lived activity in Pb, Pb-Bi and Hg targets

    SciTech Connect

    Shubin, Yu.N.

    1996-06-01

    The calculation and analysis of the nuclei concentrations and long-lived residual radioactivity accumulated in Pb, Pb-Bi and Hg targets irradiated by 800 MeV, 30 mA proton beam have been performed. The dominating components to the total radioactivity of radionuclides resulting from fission and spallation reactions and radiative capture by both target nuclei and accumulated radioactive nuclei for various irradiation and cooling times were analyzed. The estimations of spectral component contributions of neutron and proton fluxes to the accumulated activity were carried out. The contributions of fission products to the targets activity and partial activities of main long-lived fission products to the targets activity and partial activities of main long-lived fission products were evaluated. The accumulation of Po isotopes due to reactions induced by secondary alpha-particles were found to be important for the Pb target as compared with two-step radiative capture. The production of Tritium in the targets and its contribution to the total targets activity was considered in detail. It is found that total activities of both targets are close to one another.

  15. Accumulation of Advanced Glycation End-Products and Activation of the SCAP/SREBP Lipogenetic Pathway Occur in Diet-Induced Obese Mouse Skeletal Muscle

    PubMed Central

    Mastrocola, Raffaella; Collino, Massimo; Nigro, Debora; Chiazza, Fausto; D’Antona, Giuseppe; Aragno, Manuela; Minetto, Marco A.

    2015-01-01

    Aim of this study was to investigate whether advanced glycation end-products (AGEs) accumulate in skeletal myofibers of two different animal models of diabesity and whether this accumulation could be associated to myosteatosis. Male C57Bl/6j mice and leptin-deficient ob/ob mice were divided into three groups and underwent 15 weeks of dietary manipulation: standard diet-fed C57 group (C57, n = 10), high-fat high-sugar diet-fed C57 group (HFHS, n = 10), and standard diet-fed ob/ob group (OB/OB, n = 8). HFHS mice and OB/OB mice developed glycometabolic abnormalities in association with decreased mass of the gastrocnemius muscle, fast-to-slow transition of muscle fibers, and lipid accumulation (that occurred preferentially in slow compared to fast fibers). Moreover, we found in muscle fibers of HFHS and OB/OB mice accumulation of AGEs that was preferential for the lipid-accumulating cells, increased expression of the lipogenic pathway SCAP/SREBP, and co-localisation between AGEs and SCAP-(hyper)expressing cells (suggestive for SCAP glycosylation). The increased expression of the SCAP/SREBP lipogenic pathway in muscle fibers is a possible mechanism underlying lipid accumulation and linking myosteatosis to muscle fiber atrophy and fast-to-slow transition that occur in response to diabesity. PMID:25750996

  16. Protein storage vacuoles of Brassica napus zygotic embryos accumulate a BURP domain protein and perturbation of its production distorts the PSV.

    PubMed

    Teerawanichpan, Prapapan; Xia, Qun; Caldwell, Sarah J; Datla, Raju; Selvaraj, Gopalan

    2009-11-01

    BNM2is a prototypical member of the enigmatic BURP domain protein family whose members contain the signature FX6-7GX10-28PX25-31CX11-12X2SX45-56CHX10 CHX25-29CHX2TX15-16PX5CH in the C-terminus. This protein family occurs only in plants, and the cognate genes vary very widely in their expression contexts in vegetative and reproductive tissues. None of theBURP family members has been assigned any biochemical function. BNM2 was originally discovered as a gene expressed in microspore derived embryos (MDE) of Brassica napus but we found that MDE do not contain the corresponding protein. We show that BNM2 protein production is confined to the seeds and localized to the protein storage vacuoles (PSV) even though the transcript is found in vegetative parts and floral buds as well. In developing seeds, transcript accumulation precedes protein appearance by more than 18 days. RNA accumulation peaks at approximately 20 days post anthesis (DPA) whereas protein accumulation reaches its maximum at approximately 40 DPA. Transgenic expression of BNM2 does not abrogate this regulation to yield ectopic protein production or to alter the temporal aspect ofBNM2 accumulation. Overexpression ofBNM2 led to spatial distortion of storage protein accumulation within PSV and to some morphological alterations of PSVs. However, the overall storage protein content was not altered. PMID:19714473

  17. Composition of matrix in the CR chondrite LAP 02342

    NASA Astrophysics Data System (ADS)

    Wasson, John T.; Rubin, Alan E.

    2009-03-01

    We report evidence of interchondrule matrix heterogeneity on a scale of ˜50 μm in the well-preserved CR2 chondrite LAP 02342. Despite minor effects resulting from asteroidal aqueous alteration, the matrix in this CR chondrite seems to preserve much of the compositional record of nebular fines. We carried out electron-microprobe studies using a 3-μm-diameter beam; we analyzed 10 elements in 36- or 49-point grids on 11 ca. 50 × 50-μm rectangular areas of matrix. Each grid area has a distinct composition, inconsistent with a simple model of matrix material having a uniform composition throughout the nebular formation region of the CR chondrites. On S-Fe, Mg-Si, K-Na and K-Al scatter diagrams, the grid areas (i.e., different matrix patches) are largely separated from each other; plots of means with 95% confidence limits demonstrate that the compositions are resolvable. Five matrix areas were analyzed again in duplicate runs; excellent agreement was observed between duplicate studies. LAP 02342 experienced two forms of mild aqueous alteration - as patchy enrichments in Ca (inferred to reflect CaCO 3) and as regions in which sulfide laths are embedded within phyllosilicates. Despite this evidence of aqueous transport, the effect on the composition of matrix is not resolvable. For example, matrix points that were adjacent to points with high CaCO 3 contents show elemental concentrations similar to those in regions having only one or two points with a Ca enrichment. It appears that secondary minerals are found in areas where there are suitable precursor phases and voids into which new phases could grow unimpeded. Calcium appears to be unique in forming a phase that greatly lowers the Ca ++ content of the aqueous medium, thus enhancing the rate of diffusion. Because chondrules vary widely in bulk composition, the formation of chondrules in small sets (100 or less) could generate "smoke" and mesostasis spray with compositions unique to each set. However, if these

  18. Crystal structure, spectroscopic and thermal properties of [Zn(Lap)2(DMF)(H2O)] and isomorphous [M(Lap)2]n (M: Cd, Mn) complexes

    NASA Astrophysics Data System (ADS)

    Farfán, R. A.; Espíndola, J. A.; Gomez, M. I.; de Jiménez, M. C. L.; Piro, O. E.; Castellano, E. E.; Martínez, M. A.

    2015-05-01

    The solid state structure of the lapacholate (Lap-) complexes with Zn(II), Cd(II) and Mn(II) were determined by X-ray diffraction methods. [Zn(Lap)2(DMF)(H2O)] crystallizes in the triclinic space group P 1 bar with a = 10.5051(4), b = 12.8020(4), c = 13.0394(4) Å, α = 60.418(2), β = 83.904(2), γ = 86.206(2)°, and Z = 2 molecules per unit cell. The isomorphous complexes [M(Lap)2]n (M: Cd, Mn) crystallize in the tetragonal space group P43212 with a = b = 13.5770(6) Å, c = 14.5730(6) Å (Cd), and a = b = 13.3539(4), c = 14.7148(4) Å (Mn), and Z = 4. In [Zn(Lap)2(DMF)(H2O)] the Zn(II) ion is in a distorted octahedral environment coordinated to two different and nearly perpendicular Lap- molecules acting as bidentate ligands through their adjacent carbonyl and phenol oxygen atoms. The remaining two cis-coordination sites are occupied by water and DMF molecules. [M(Lap)2]n (M: Cd, Mn) isomorphous complexes are also octahedral and present a supra-molecular arrangement in the lattice. There is only one independent Lap- molecule that coordinates the metal through all three ligand binding sites, giving rise to a 3-D structure of [M(Lap)2]n complexes that extends throughout the crystal lattice. The lapachol binding to metal is also revealed by the IR spectra. In fact, the carbonyl Cdbnd O stretching frequency is appreciable red-shifted in the complexes as compared to uncoordinated lapachol ligand. As expected, the IR and UV-Vis spectra of the isomorphous pair of complexes closely resemble to each other. Up to above 300 °C there are significant differences in the TGA of the Zn complex when compared with the isomorphous pair: while the former shows the loss of the secondary ligands (water and DMF), the latter exhibits a plateau signaling the lesser labile character of the lapacholate ligand.

  19. Comparison of Methylmercury Production and Accumulation in Sediments of the Congaree and Edisto River Basins, South Carolina, 2004-06

    USGS Publications Warehouse

    Bradley, Paul M.; Chapelle, Francis H.; Journey, Celeste A.

    2009-01-01

    Fish-tissue mercury concentrations (approximately 2 micrograms per gram) in the Edisto River basin of South Carolina are among the highest recorded in the United States. Substantially lower mercury concentrations (approximately 0.2 microgram per gram) are reported in fish from the adjacent (about 30 kilometer) Congaree River basin and the Congaree National Park. In contrast, concentrations of total mercury were statistically higher in sediments from the Congaree River compared with those in sediments from the Edisto River. Furthermore, no statistically significant difference was observed in concentrations of methylmercury or net methylation potential in sediments collected from various Edisto and Congaree hydrologic settings. In both systems, the net methylation potential was low (0-0.17 nanogram per gram per day) for in-stream sediments exposed to continuously flowing water but substantially higher (about 1.8 nanograms per gram per day) in wetland sediments exposed to standing water. These results are not consistent with the hypothesis that differences in fish-tissue mercury between the Edisto and Congaree basins reflect fundamental differences in the potential for each system to methylate mercury. Rather, the significantly higher ratios of methylmercury to total mercury observed in the Edisto system suggest that the net accumulation and(or) preservation of methylmercury are greater in the Edisto system. The marked differences in net methylation potential observed between the wetland and in-stream settings suggest the hypothesis that methylmercury transport from zones of production (wetlands) to points of entry into the food chain (channels) may contribute to the observed differences in fish-tissue mercury concentrations between the two river systems.

  20. Productivity and selective accumulation of carotenoids of the novel extremophile microalga Chlamydomonas acidophila grown with different carbon sources in batch systems.

    PubMed

    Cuaresma, María; Casal, Carlos; Forján, Eduardo; Vílchez, Carlos

    2011-01-01

    Cultivation of extremophile microorganisms has attracted interest due to their ability to accumulate high-value compounds. Chlamydomonas acidophila is an acidophile green microalga isolated by our group from Tinto River, an acidic river that flows down from the mining area in Huelva, Spain. This microalga accumulates high concentrations of lutein, a very well-known natural antioxidant. The aim of this study is to assess use of different carbon sources (CO(2), glucose, glycerol, starch, urea, and glycine) for efficient growth of and carotenoid production by C. acidophila. Our results reveal that growth of the microalga on different carbon sources resulted in different algal biomass productivities, urea being as efficient as CO(2) when used as sole carbon source (~20 g dry biomass m(-2) day(-1)). Mixotrophic growth on glucose was also efficient in terms of biomass production (~14 g dry biomass m(-2) day(-1)). In terms of carotenoid accumulation, mixotrophic growth on urea resulted in even higher productivity of carotenoids (mainly lutein, probably via α-carotene) than obtained with photoautotrophic cultures (70% versus 65% relative abundance of lutein, respectively). The accumulated lutein concentrations of C. acidophila reported in this work (about 10 g/kg dry weight, produced in batch systems) are among the highest reported for a microalga. Glycerol and glycine seem to enhance β-carotene biosynthesis, and when glycine is used as carbon source, zeaxanthin becomes the most accumulated carotenoid in the microalga. Strategies for production of lutein and zeaxanthin are suggested based on the obtained results. PMID:20811803

  1. Fabrication of micro nickel/diamond abrasive pellet array lapping tools using a LIGA-like technology

    NASA Astrophysics Data System (ADS)

    Luo, Sheng-Yih; Yu, Tsung-Han; Hu, Yuh-Chung

    2007-06-01

    A manufacturing process of micro nickel/diamond abrasive pellet array lapping tools using a LIGA-like technology is reported here. The thickness of JSR THB-151N resist coated on an aluminum alloy substrate for micro lithography can reach up to 110 µm. During the lithography, different geometrical photomasks were used to create specific design patterns of the resist mold on the substrate. Micro roots, made by electrolytic machining on the substrate with guidance of the resist mold, can improve the adhesion of micro nickel abrasive pellets electroplated on the substrate. During the composite electroforming, the desired hardness of the nickel matrix inside the micro diamond abrasive pellets can be obtained by the addition of leveling and stress reducing agents. At moderate blade agitation and ultrasonic oscillation, higher concentration and more uniform dispersion of diamond powders deposited in the nickel matrix can be achieved. With these optimal experiment conditions of this fabrication process, the production of micro nickel/diamond abrasive pellet array lapping tools is demonstrated.

  2. Fatigue strength of a single lap joint SPR-bonded

    SciTech Connect

    Di Franco, G.; Fratini, L.; Pasta, A.

    2011-05-04

    In the last years, hybrid joints, meaning with this the joints which consist in combining a traditional mechanical joint to a layer of adhesive, are gradually attracting the attention of various sectors of the construction of vehicles and transportation industries, for their better performance compared to just mechanical joints (self-piercing riveting SPR, riveting, and so on) or just to bonded joints.The paper investigates the fatigue behavior of a single lap joint self-piercing riveted (SPR) and bonded throughout fatigue tests. The considered geometric configuration allowed the use of two rivets placed longitudinally; an epoxy resin was used as adhesive. In the first part of the work static characterization of the joints was carried out through tensile tests. Then fatigue tests were made with the application of different levels of load. The fatigue curves were also obtained at the varying the distance between the two rivets in order to better assess the joint strength for a given length of overlap.

  3. Experimental Investigations of an Inclined Lap-Type Bolted Joint

    SciTech Connect

    GREGORY, DANNY LYNN; RESOR, BRIAN R.; COLEMAN, RONALD G.; SMALLWOOD, DAVID ORA

    2003-04-01

    The dynamic response of critical aerospace components is often strongly dependent upon the dynamic behavior of bolted connections that attach the component to the surrounding structure. These bolted connections often provide the only structural load paths to the component. The bolted joint investigated in this report is an inclined lap-type joint with the interface inclined with respect to the line of action of the force acting on the joint. The accurate analytical modeling of these bolted connections is critical to the prediction of the response of the component to normal and high-level shock environmental loadings. In particular, it is necessary to understand and correctly model the energy dissipation (damping) of the bolted joint that is a nonlinear function of the forces acting on the joint. Experiments were designed and performed to isolate the dynamics of a single bolted connection of the component. Steady state sinusoidal and transient experiments were used to derive energy dissipation curves as a function of input force. Multiple assemblies of the bolted connection were also observed to evaluate the variability of the energy dissipation of the connection. These experiments provide insight into the complex behavior of this bolted joint to assist in the postulation and development of reduced order joint models to capture the important physics of the joint including stiffness and damping. The experiments are described and results presented that provide a basis for candidate joint model calibration and comparison.

  4. Correlation of different spectral lights with biomass accumulation and production of antioxidant secondary metabolites in callus cultures of medicinally important Prunella vulgaris L.

    PubMed

    Fazal, Hina; Abbasi, Bilal Haider; Ahmad, Nisar; Ali, Syed Shujait; Akbar, Fazal; Kanwal, Farina

    2016-06-01

    Light is one of the key elicitors that directly fluctuates plant developmental processes and biosynthesis of secondary metabolites. In this study, the effects of various spectral lights on biomass accumulation and production of antioxidant secondary metabolites in callus cultures of Prunella vulgaris were investigated. Among different spectral lights, green light induced the maximum callogenic response (95%). Enhanced fresh biomass accumulation was observed in log phases on day-35, when callus cultures were exposed to yellow and violet lights. Yellow light induced maximum biomass accumulation (3.67g/100ml) from leaf explants as compared to control (1.27g/100ml). In contrast, violet lights enhanced biomass accumulation (3.49g/100ml) from petiole explant. Maximum total phenolics content (TPC; 23.9mg/g-DW) and total flavonoids content (TFC; 1.65mg/g-DW) were observed when cultures were grown under blue lights. In contrast, green and yellow lights enhanced total phenolics production (TPP; 112.52g/100ml) and total flavonoids production (TFP; 9.64g/100ml) as compared to control. The calli grown under green, red and blue lights enhanced DPPH-free radical scavenging activity (DFRSA; 91.3%, 93.1% and 93%) than control (56.44%) respectively. The DFRSA was correlated either with TPC and TFC or TPP and TFP. Furthermore, yellow lights enhanced superoxide dismutase (SOD), peroxidase (POD) and protease activities, however, the content of total protein (CTP) was higher in control cultures (186μg BSAE/mg FW) as compared to spectral lights. These results suggest that the exposure of callus cultures to various spectral lights have shown a key role in biomass accumulation and production of antioxidant secondary metabolites. PMID:26995670

  5. Pycnogenol® inhibits lipid accumulation in 3T3-L1 adipocytes with the modulation of reactive oxygen species (ROS) production associated with antioxidant enzyme responses.

    PubMed

    Lee, Ok-Hwan; Seo, Min-Jung; Choi, Hyeon-Son; Lee, Boo-Yong

    2012-03-01

    Pycnogenol® is a group of flavonoids with antioxidant effects. Adipogenesis is the process of adipocyte differentiation. It causes the increase of lipids as well as ROS (reactive oxygen species). Lipid accumulation and ROS production were determined in 3 T3-L1 adipocyte, and the effect of Pycnogenol® was evaluated. Lipid accumulation was elevated in adipocyte treated with hydrogen peroxide, one of the ROS. Pycnogenol® showed an inhibitory effect on the lipid accumulation and ROS production during the adipogenesis. We also investigated the molecular events associated with ROS production and lipid accumulation. Our results showed that Pycnogenol® inhibited the mRNA expression of pro-oxidant enzymes, such as NOX4 (NADPH (nicotinamide adenine dinucleotide phosphate hydrogen) oxidase 4), and the NADPH-producing G6PDH (glucose-6-phosphate dehydrogenase) enzyme. In addition, Pycnogenol® suppressed the mRNA abundance of adipogenic transcription factors, PPAR-γ (peroxisome proliferator-activated receptor γ) and C/EBP-α (CCAAT/enhancer binding protein α), and their target gene, aP2 (adipocyte protein 2) responsible for fatty acid transportation. On the other hand, Pycnogenol® increased the abundance of antioxidant proteins such as Cu/Zn-SOD (copper-zinc superoxide dismutase), Mn-SOD (manganese superoxide dismutase), GPx (glutathione peroxidase) and GR (glutathione reductase). Our results suggest that Pycnogenol® inhibits lipid accumulation and ROS production by regulating adipogenic gene expression and pro-/antioxidant enzyme responses in adipocytes. PMID:21796705

  6. "DIAGNOSTIC" PULSE FOR SINGLE-PARTICLE-LIKE BEAM POSITION MEASUREMENTS DURING ACCUMULATION/PRODUCTION MODE IN THE LOS ALAMOS PROTON STORAGE RING

    SciTech Connect

    Kolski, Jeffrey S.; Baily, Scott A.; Bjorklund, Eric A.; Bolme, Gerald O.; Hall, Michael J.; Kwon, Sung I.; Martinez, Martin P.; Prokop, Mark S.; Shelley, Fred E. Jr.; Torrez, Phillip A.

    2012-05-14

    Beam position monitors (BPMs) are the primary diagnostic in the Los Alamos Proton Storage Ring (PSR). When injecting one turn, the transversemotion is approximated as a single particle with initial betatron position and angle {rvec x}{sub 0} and {rvec x}'{sub 0}. With single-turn injection, we fit the betatron tune, closed orbit (CO), and injection offset ({rvec x}{sub 0} and {rvec x}'{sub 0} at the injection point) to the turn-by-turn beam position. In production mode, we accumulate multiple turns, the transverse phase space fills after 5 injections (horizontal and vertical fractional betatron tunes {approx}0.2) resulting in no coherent betatron motion, and only the CO may be measured. The injection offset, which determines the accumulated beam size and is very sensitive to steering upstream of the ring, is not measurable in production mode. We describe our approach and ongoing efforts to measure the injection offset during production mode by injecting a 'diagnostic' pulse {approx}50 {micro}s after the accumulated beam is extracted. We also study the effects of increasing the linac RF gate length to accommodate the diagnostic pulse on the production beam position, transverse size, and loss.

  7. Weed management practices for organic production of trailing blackberry. II. Accumulation and loss of plant biomass and nutrients

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted to assess the impact of cultivar and weed management on accumulation and loss of plant biomass and nutrients during the first 3 years of establishment when using organic fertilizer in trailing blackberry. Treatments included two cultivars, Marion and Black Diamond, each with ei...

  8. Large-scale Advanced Prop-fan (LAP) high speed wind tunnel test report

    NASA Technical Reports Server (NTRS)

    Campbell, William A.; Wainauski, Harold S.; Arseneaux, Peter J.

    1988-01-01

    High Speed Wind Tunnel testing of the SR-7L Large Scale Advanced Prop-Fan (LAP) is reported. The LAP is a 2.74 meter (9.0 ft) diameter, 8-bladed tractor type rated for 4475 KW (6000 SHP) at 1698 rpm. It was designated and built by Hamilton Standard under contract to the NASA Lewis Research Center. The LAP employs thin swept blades to provide efficient propulsion at flight speeds up to Mach .85. Testing was conducted in the ONERA S1-MA Atmospheric Wind Tunnel in Modane, France. The test objectives were to confirm that the LAP is free from high speed classical flutter, determine the structural and aerodynamic response to angular inflow, measure blade surface pressures (static and dynamic) and evaluate the aerodynamic performance at various blade angles, rotational speeds and Mach numbers. The measured structural and aerodynamic performance of the LAP correlated well with analytical predictions thereby providing confidence in the computer prediction codes used for the design. There were no signs of classical flutter throughout all phases of the test up to and including the 0.84 maximum Mach number achieved. Steady and unsteady blade surface pressures were successfully measured for a wide range of Mach numbers, inflow angles, rotational speeds and blade angles. No barriers were discovered that would prevent proceeding with the PTA (Prop-Fan Test Assessment) Flight Test Program scheduled for early 1987.

  9. The Nuclear Envelope Protein, LAP1B, Is a Novel Protein Phosphatase 1 Substrate

    PubMed Central

    Santos, Mariana; Rebelo, Sandra; Van Kleeff, Paula J. M.; Kim, Connie E.; Dauer, William T.; Fardilha, Margarida; da Cruz e Silva, Odete A.; da Cruz e Silva, Edgar F.

    2013-01-01

    Protein phosphatase 1 (PP1) binding proteins are quintessential regulators, determining substrate specificity and defining subcellular localization and activity of the latter. Here, we describe a novel PP1 binding protein, the nuclear membrane protein lamina associated polypeptide 1B (LAP1B), which interacts with the DYT1 dystonia protein torsinA. The PP1 binding domain in LAP1B was here identified as the REVRF motif at amino acids 55-59. The LAP1B:PP1 complex can be immunoprecipitated from cells in culture and rat cortex and the complex was further validated by yeast co-transformations and blot overlay assays. PP1, which is enriched in the nucleus, binds to the N-terminal nuclear domain of LAP1B, as shown by immunocolocalization and domain specific binding studies. PP1 dephosphorylates LAP1B, confirming the physiological relevance of this interaction. These findings place PP1 at a key position to participate in the pathogenesis of DYT1 dystonia and related nuclear envelope-based diseases. PMID:24116158

  10. Intracellular accumulation of AMP as a cause for the decline in rate of ethanol production by Saccharomyces cerevisiae during batch fermentation

    SciTech Connect

    Dombek, K.M.; Ingram, L.O.

    1988-01-01

    A general hypothesis is presented for the decline in the rate of ethanol production (per unit of cell protein) during batch fermentation. Inhibition of ethanol production is proposed to result from the intracellular accumulation of AMP during the transition from growth to the stationary phase. AMP acts as a competitive inhibitor of hexokinase with respect to ATP. When assayed in vitro in the presence of ATP and AMP concentration equivalent to those within cells at different stages of fermentation, hexokinase activity declined in parallel with the in vivo decline in the rate of ethanol production. The coupling of glycolytic flux and fermentation to cell growth via degradation products of RNA may be of evolutionary advantage for Saccharomyces cerevisiae. Such a coupling would reduce the exposure of nongrowing cells to potentially harmful concentrations of waste products from metabolism and would conserve nutrients for future growth under more favorable conditions.

  11. Remediation and Safe Production of cd Contaminated Soil Via Multiple Cropping Hyperaccumulator Solanum nigrum L. and Low Accumulation Chinese Cabbage.

    PubMed

    Niu, Mingfen; Wei, Shuhe; Bai, Jiayi; Wang, Siqi; Ji, Dandan

    2015-01-01

    Multiple crop experiment of hyperaccumulator Solanum nigrum L. with low accumulation Chinese cabbage Fenyuanxin 3 were conducted in a cadmium (Cd) contaminated vegetable field. In the first round, the average removal rate of S. nigrum to Cd was about 10% without assisted phytoextraction reagent addition for the top soil (0-20 cm) with Cd concentration at 0.53-0.97 mg kg(-1) after its grew 90 days. As for assisted phytoextraction reagent added plots, efficiency of Cd remediation might reach at 20%. However, in the second round, Cd concentration in Chinese cabbage was edible, even in the plots with assisted phytoextraction reagent added. Thus, multiple cropping hyperaccumulator with low accumulation crop could normally remediate contaminated soil and produce crop (obtain economic benefit) in one year, which may be one practical pathway of phytoremediating heavy metal contaminated soil in the future. PMID:25976879

  12. Intrauterine infusion of latency-associated peptide (LAP) during early porcine pregnancy affects conceptus elongation and placental size.

    PubMed

    Massuto, Dana A; Hooper, R Neil; Kneese, Eric C; Johnson, Greg A; Ing, Nancy H; Weeks, Bradley R; Jaeger, Laurie A

    2010-03-01

    In the pig, transforming growth factor beta (TGFB), TGFB receptors (TGFBRs), and integrins are present during the peri-implantation period. Latency-associated peptide (LAP), a part of latent TGFB, can bind to integrin heterodimers via its Arg-Gly-Asp (RGD) sequence; therefore, ligand-receptor interactions between TGFB and TGFBRs, along with LAP and integrin heterodimers, may be functional in mediating events supporting conceptus elongation and attachment. With the use of surgically implantable osmotic pumps, we were able to maintain pregnancy with the aim of mechanistically altering in vivo receptor-ligand interactions involving TGFB with TGFBRs and LAP with integrins during porcine pregnancy. Day 9 pregnant gilts received intrauterine infusions of LAP-RGD, a recombinant mutant of LAP (LAP-RGE), or vehicle control and were ovariohysterectomized on Day 13 or 24 of pregnancy. We hypothesized that intrauterine infusion of LAP-RGD would decrease downstream signaling of TGFB while increasing LAP-integrin interactions and that net effect would enhance conceptus survival and attachment early in the peri-implantation period but possibly increase the chance of abnormal placentation later in pregnancy. Additionally, we hypothesized that infusion of LAP-RGE would disrupt TGFB signals but not alter integrin signaling, and thus the net result would be decreased conceptus survival and abnormal development. Unexpectedly, LAP-RGD intrauterine infusions resulted in a reduction of conceptus elongation, whereas infusions of LAP-RGE permitted implantation and placentation but resulted in larger fetal weight, allantois length, and allantoic fluid volume. Results suggest TGFB and integrins are contributing factors in the regulation of conceptus elongation and placental and fetal size. PMID:19906685

  13. Characterization of oleaginous yeasts accumulating high levels of lipid when cultivated in glycerol and their potential for lipid production from biodiesel-derived crude glycerol.

    PubMed

    Polburee, Pirapan; Yongmanitchai, Wichien; Lertwattanasakul, Noppon; Ohashi, Takao; Fujiyama, Kazuhito; Limtong, Savitree

    2015-12-01

    This study attempted to identify oleaginous yeasts and selected the strain that accumulated the largest quantity of lipid for lipid production from glycerol. Two-step screening of 387 yeast strains revealed 23 oleaginous strains that accumulated quantities of lipid higher than 20 % of their biomass when cultivated in glycerol. These strains were identified to be four ascomycetous yeast species i.e. Candida silvae, Kodamaea ohmeri, Meyerozyma caribbica, and Pichia manshurica, and five basidiomycetous yeast species i.e. Cryptococcus cf. podzolicus, Cryptococcus laurentii, Rhodosporidium fluviale, Rhodotorula taiwanensis, and Sporidiobolus ruineniae. Rhodosporidium fluviale DMKU-RK253 accumulated the highest quantity of lipid equal to 65.2 % of its biomass (3.9 g L(-1) lipid and 6.0 g L(-1) biomass) by shaking flask cultivation in crude glycerol. The main fatty acids in the accumulated lipid of this strain consisted of oleic acid, linoleic acid, and palmitic acid. Therefore, R. fluviale DMKU-RK253 has potential for producing lipid for biodiesel manufacturing using crude glycerol as a feedstock. PMID:26615742

  14. Detection of Hidden Cracks on Aircraft LAP Joints with GMR Based Eddy Current Technology

    SciTech Connect

    Na, J. K.; Franklin, M. A.; Linn, J. R.

    2006-03-06

    Cracks occurring on commercial aircraft fuselage lap joints made of aluminum alloys often caused by scribe lines made during the removal of process of moisture sealing materials between two layers. These cracks on thinner bottom skin layers can be obscured by thicker top plates with paint. A portable GMR (Giant Magnetoresistive) sensor based eddy current system has been developed and tested on several simulated aircraft lap joints samples with EDM notches. Various thicknesses of layers are used to simulate the test as used on different combinations of lap joints. Length and depth of cracks are important factors for the safety of aircraft. Test results are used to come up with a portable nondestructive inspection system which is easy and fast with a high reliability of detecting cracks longer than a half inch in length and 0.010 inches in depth.

  15. Measurements of fuselage skin strains and displacements near a longitudinal lap joint in a pressurized aircraft

    NASA Technical Reports Server (NTRS)

    Phillips, Edward P.; Britt, Vicki O.

    1991-01-01

    Strains and displacements in a small area near a longitudinal lap joint in the fuselage skin of a B737 aircraft were measured during a pressurization cycle to a differential pressure of 6.2 psi while the aircraft was on the ground. It was found that hoop strains were higher than longitudinal strains at each location; membrane strains in the unreinforced skin were higher than in the joint; membrane strains in the hoop direction, as well as radial displacements, tended to be highest at the mid-bay location between skin reinforcements; significant bending in the hoop direction occurred in the joint and in the skin near the joint, and the bending was unsymmetrically distributed about the stringer at the middle of the joint; and radial displacements were unsymmetrically distributed across the lap joint. The interpretation of the strain gage data for locations on the bonded and riveted lap joint assumed that the joint did not contain disbonded areas.

  16. EFFECT OF TOOL FEATURE ON THE JOINT STRENGTH OF DISSIMILAR FRICTION STIR LAP WELDS

    SciTech Connect

    Jana, Saumyadeep; Hovanski, Yuri; Grant, Glenn J.; Mattlin, Karl F.

    2011-04-25

    Several variations of friction stir tools were used to investigate the effects on the joint strengths of dissimilar friction stir lap welds. In the present lap weld configuration the top sheet was a 2.32 mm thick Mg (AZ 31) alloy. The bottom sheet consisted of two different steels, a (i) 0.8 mm thick electro-galvanized (EG) mild steel, or a (ii) 1.5 mm thick hot dip galvanized (HDG) high strength low alloy (HSLA) steel. Initially the tool shape was modified to accommodate the material, at which point the tool geometry was fixed. With a fixed tool geometry an additional feature was added to the pin bottom on one of the tools by incorporating a short hard insert, which would act as a stronger bottom sheet cutter. The effects of such modification on the unguided lap shear strength, and associated microstructural changes are discussed in this study.

  17. Age of Lunar Meteorite LAP02205 and Implications for Impact-Sampling of Planetary Surfaces

    NASA Technical Reports Server (NTRS)

    Nyquist, L. E.; Shih, C.-Y.; Reese, Y.; Bogard, D. D.

    2005-01-01

    We have measured the age of lunar meteorite LAP02205 by the Rb-Sr and Ar-Ar methods. Sm-Nd analyses are in progress. The Rb-Sr and Ar-Ar ages indicate a crystallization age of approx. 3 Ga. Comparing the ages of LAP02205 and other lunar mare basaltic meteorites to mare surface ages based on the density of impact craters shows no significant bias in impact- sampling of lunar mare surfaces. Comparing the isotopic and geochemical data for LAP02205 to those for other lunar mare basalts suggests that it is a younger variant of the type of volcanism that produced the Apollo 12 basalts. Representative impact-sampling of the lunar surface

  18. Large-scale Advanced Prop-fan (LAP) technology assessment report

    NASA Technical Reports Server (NTRS)

    Degeorge, C. L.

    1988-01-01

    The technologically significant findings and accomplishments of the Large Scale Advanced Prop-Fan (LAP) program in the areas of aerodynamics, aeroelasticity, acoustics and materials and fabrication are described. The extent to which the program goals related to these disciplines were achieved is discussed, and recommendations for additional research are presented. The LAP program consisted of the design, manufacture and testing of a near full-scale Prop-Fan or advanced turboprop capable of operating efficiently at speeds to Mach .8. An aeroelastically scaled model of the LAP was also designed and fabricated. The goal of the program was to acquire data on Prop-Fan performance that would indicate the technology readiness of Prop-Fans for practical applications in commercial and military aviation.

  19. Lapped orthogonal transform coding by amplitude and group partitioning

    NASA Astrophysics Data System (ADS)

    Zou, Xiangyu; Pearlman, William A.

    1999-10-01

    Transform coding has been the focus of the research for image compression. In previous research, the Amplitude and Group Partitioning (AGP) coding scheme is proved to be a low complexity algorithm with higher performance, clearly one of the state-of-art transform coding techniques. However, the previous AGP is used along with the Discrete Cosine Transform (DCT) and the discrete wavelet transform. In this paper, a different transform, the Lapped Orthogonal Transform (LOT), replaces the DCT in conjunction with the AGP. This is the first time LOT and AGP have been combined in a coding method. The definition and design of the LOT are discussed. An objective metric to measure the performance of transform, coding gain, is calculated for both the DCT and the LOT. The LOT has slightly higher coding gain than the DCT. The principles of the LOT based AGP image codec (LOT-AGP) are presented and a complete codec, encoder and decoder, is implemented in software. The performance of the LOT-AGP is compared with other block transform coding schemes: the baseline JPEG codec and the DCT based AGP image codec (DCT- AGP) by both objective evaluation and subjective evaluation. The Peak Signal to Noise Ratio (PSNR) is calculated for these three coding schemes. The two AGP codecs are much better than the JPEG codec on PSNR, from about 1.7 dB to 3 dB depending on bit rate. The two AGP schemes have PSNR differences only to a small degree. Visually, the LOT-AGP has the best-reconstructed images among these three at all bit rates. In addition, the coding results of two other state-of-art progressive image codecs are cited for further comparison. One is the Set Partitioning in Hierarchical Trees (SPIHT) algorithm with a dyadic wavelet transform, and the other is Tran and Nguyen's method with the generalized LOT transform. The AGP coding and the adaptive Huffman entropy coding of LOT-AGP are less complex and the memory usage is smaller than in these two progressive codecs. Comparing these

  20. Failure strength prediction for adhesively bonded single lap joints

    NASA Astrophysics Data System (ADS)

    Rahman, Niat Mahmud

    For adhesively bonded joint, failure strength depends on many factors such as material properties (both adhesive and adherend), specimen geometries, test environments, surface preparation procedures, etc. Failure occurs inside constitutive materials or along joint interfaces. Based on location, adhesively bonded failure mode can be classified as adhesive failure mode, cohesive failure mode and adherend failure mode. Failure mode directly affects the failure strength of joint. For last eight decades, researchers have developed analytical, empirical or semi-empirical methods capable of predicting failure strength for adhesively bonded joints generating either cohesive failure or adherend failure. Applicability of most of the methods is limited to particular cases. In this research, different failure modes for single lap joints (SLJs) were generated experimentally using epoxy based paste adhesive. Based on experimental data and analytical study, simplified failure prediction methods were developed for each failure mode. For adhesive failure mode, it is observed that peel stress distributions concur along interface near crack initiation points. All SLJs for this test endured consistent surface treatments. Geometric parameters of the joints were varied to study their effect on failure strength. Peel stress distributions were calculated using finite analysis (FEA). Based on peel stress distribution near crack initiation point, a failure model is proposed. Numerous analytical, empirical and semi-empirical models are available for predicting failure strengths of SLJs generating cohesive failures. However, most of the methods in the literature failed to capture failure behavior of SLJs having thickness of adhesive layer as variable. Cohesive failure mode was generated experimentally using aluminum as adherend and epoxy adhesive considering thickness of adhesive layers as variable within SLJs. Comparative study was performed among various methods. It was observed that

  1. Non destructive evaluation of adhesively bonded carbon fiber reinforced composite lap joints with varied bond quality

    NASA Astrophysics Data System (ADS)

    Vijayakumar, R. L.; Bhat, M. R.; Murthy, C. R. L.

    2012-05-01

    Structural adhesive bonding is widely used to execute assemblies in automobile and aerospace structures. The quality and reliability of these bonded joints must be ensured during service. In this context non destructive evaluation of these bonded structures play an important role. Evaluation of adhesively bonded composite single lap shear joints has been attempted through experimental approach. Series of tests, non-destructive as well as destructive were performed on different sets of carbon fiber reinforced polymer (CFRP) composite lap joint specimens with varied bond quality. Details of the experimental investigations carried out and the outcome are presented in this paper.

  2. Accumulate Repeat Accumulate Coded Modulation

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  3. LAP TGF-Beta Subset of CD4+CD25+CD127− Treg Cells is Increased and Overexpresses LAP TGF-Beta in Lung Adenocarcinoma Patients

    PubMed Central

    Islas-Vazquez, Lorenzo; Prado-Garcia, Heriberto; Aguilar-Cazares, Dolores; Meneses-Flores, Manuel; Galicia-Velasco, Miriam; Romero-Garcia, Susana; Camacho-Mendoza, Catalina; Lopez-Gonzalez, Jose Sullivan

    2015-01-01

    Lung cancer is the leading cause of cancer death worldwide. Adenocarcinoma, the most commonly diagnosed histologic type of lung cancer, is associated with smoking. Cigarette smoke promotes inflammation on the airways, which might be mediated by Th17 cells. This inflammatory environment may contribute to tumor development. In contrast, some reports indicate that tumors may induce immunosuppressive Treg cells to dampen immune reactivity, supporting tumor growth and progression. Thus, we aimed to analyze whether chronic inflammation or immunosuppression predominates at the systemic level in lung adenocarcinoma patients, and several cytokines and Th17 and Treg cells were studied. Higher proportions of IL-17-producing CD4+ T-cells were found in smoking control subjects and in lung adenocarcinoma patients compared to nonsmoking control subjects. In addition, lung adenocarcinoma patients increased both plasma concentrations of IL-2, IL-4, IL-6, and IL-10, and proportions of Latency Associated Peptide (LAP) TGF-β subset of CD4+CD25+CD127− Treg cells, which overexpressed LAP TGF-β. This knowledge may lead to the development of immunotherapies that could inhibit the suppressor activity mediated by the LAP TGF-β subset of CD4+CD25+CD127− Treg cells to promote reactivity of immune cells against lung adenocarcinoma cells. PMID:26582240

  4. The “Lipid Accumulation Product” Is Associated with 2-Hour Postload Glucose Outcomes in Overweight/Obese Subjects with Nondiabetic Fasting Glucose

    PubMed Central

    Malavazos, Alexis Elias; Cereda, Emanuele; Ermetici, Federica; Caccialanza, Riccardo; Briganti, Silvia; Rondanelli, Mariangela; Morricone, Lelio

    2015-01-01

    “Lipid accumulation product” (LAP) is a continuous variable based on waist circumference and triglyceride concentration previously associated with insulin resistance. We investigated the accuracy of LAP in identifying oral glucose tolerance test (OGTT) abnormalities and compared it to the homeostasis model assessment of insulin resistance (HOMA-IR) in a population of overweight/obese outpatients presenting with nondiabetic fasting glucose. We studied 381 (male: 23%) adult (age: 18–70 years) overweight/obese Caucasians (body mass index: 36.9 ± 5.4 Kg/m2) having fasting plasma glucose < 7.0 mmol/L. OGTT was used to diagnose unknown glucose tolerance abnormalities: impaired glucose tolerance (IGT) and type-2 diabetes mellitus (T2-DM). According to OGTT 92, subjects had an IGT and 33 were diagnosed T2-DM. Logistic regression analysis detected a significant association for both LAP and HOMA-IR with single (IGT and T2-DM) and composite (IGT + T2-DM) abnormal glucose tolerance conditions. However, while the association with diabetes was similar between LAP and HOMA-IR, the relationship with IGT and composite outcomes by models including LAP was significantly superior to those including HOMA-IR (P = 0.006 and P = 0.007, resp.). LAP seems to be an accurate index, performing better than HOMA-IR, for identifying 2-hour postload OGTT outcomes in overweight/obese patients with nondiabetic fasting glucose. PMID:25792981

  5. Anaerobic fermentation combined with low-temperature thermal pretreatment for phosphorus-accumulating granular sludge: Release of carbon source and phosphorus as well as hydrogen production potential.

    PubMed

    Zou, Jinte; Li, Yongmei

    2016-10-01

    Releases of organic compounds and phosphorus from phosphorus-accumulating granular sludge (PGS) and phosphorus-accumulating flocculent sludge (PFS) during low-temperature thermal pretreatment and anaerobic fermentation were investigated. Meanwhile, biogas production potential and microbial community structures were explored. The results indicate that much more soluble chemical oxygen demand (SCOD) and phosphorus were released from PGS than from PFS via low-temperature thermal pretreatment because of the higher extracellular polymeric substances (EPS) content in PGS and higher ratio of phosphorus reserved in EPS. Furthermore, PGS contains more anaerobes and dead cells, resulting in much higher SCOD and volatile fatty acids release from PGS than those from PFS during fermentation. PGS fermentation facilitated the n-butyric acid production, and PGS exhibited the hydrogen production potential during fermentation due to the presence of hydrogen-producing bacteria. Therefore, anaerobic fermentation combined with low-temperature thermal pretreatment can facilitate the recovery of carbon and phosphorus as well as producing hydrogen from PGS. PMID:27344244

  6. Improving Critical Thinking Skills Using Learning Model Logan Avenue Problem Solving (LAPS)-Heuristic

    ERIC Educational Resources Information Center

    Anggrianto, Desi; Churiyah, Madziatul; Arief, Mohammad

    2016-01-01

    This research was conducted in order to know the effect of Logan Avenue Problem Solving (LAPS)-Heuristic learning model towards critical thinking skills of students of class X Office Administration (APK) in SMK Negeri 1 Ngawi, East Java, Indonesia on material curve and equilibrium of demand and supply, subject Introduction to Economics and…

  7. The Introduction of Crystallographic Concepts Using Lap-Dissolve Slide Techniques.

    ERIC Educational Resources Information Center

    Bodner, George M.; And Others

    1980-01-01

    Describes a method using lap-dissolve slide techniques with two or more slide projectors focused on a single screen for presenting visual effects that show structural features in extended arrays of atoms, or ions involving up to several hundred atoms. Presents an outline of an introduction to the structures of crystalline solids. (CS)

  8. Progerin reduces LAP2α-telomere association in Hutchinson-Gilford progeria.

    PubMed

    Chojnowski, Alexandre; Ong, Peh Fern; Wong, Esther S M; Lim, John S Y; Mutalif, Rafidah A; Navasankari, Raju; Dutta, Bamaprasad; Yang, Henry; Liow, Yi Y; Sze, Siu K; Boudier, Thomas; Wright, Graham D; Colman, Alan; Burke, Brian; Stewart, Colin L; Dreesen, Oliver

    2015-01-01

    Hutchinson-Gilford progeria (HGPS) is a premature ageing syndrome caused by a mutation in LMNA, resulting in a truncated form of lamin A called progerin. Progerin triggers loss of the heterochromatic marker H3K27me3, and premature senescence, which is prevented by telomerase. However, the mechanism how progerin causes disease remains unclear. Here, we describe an inducible cellular system to model HGPS and find that LAP2α (lamina-associated polypeptide-α) interacts with lamin A, while its interaction with progerin is significantly reduced. Super-resolution microscopy revealed that over 50% of telomeres localize to the lamina and that LAP2α association with telomeres is impaired in HGPS. This impaired interaction is central to HGPS since increasing LAP2α levels rescues progerin-induced proliferation defects and loss of H3K27me3, whereas lowering LAP2 levels exacerbates progerin-induced defects. These findings provide novel insights into the pathophysiology underlying HGPS, and how the nuclear lamina regulates proliferation and chromatin organization. PMID:26312502

  9. Correlates of Mood and RPE During Multi-Lap Off-Road Cycling.

    PubMed

    Viana, Bruno Ferreira; Pires, Flávio Oliveira; Inoue, Allan; Micklewright, Dominic; Santos, Tony Meireles

    2016-03-01

    This study examined the relationship between mood and rating of perceived exertion (RPE) during a simulated multiple-lap time trial (MLTT). Nineteen male cyclists performed a MLTT consisting of four 9.9 km laps, each lap with a gradient ranging from 0 to 10 %. Mood as measured by the Profile of Mood States Questionnaire (POMS) and perceived exertion as measured by the Borg CR100 scale (RPE) were obtained at the end of each lap. A categorical multiple regressive model, having median of POMS subscales as independent variables, was obtained to explain the variance in median RPE responses. Increases in POMS fatigue scores and decreases in POMS vigour scores were observed throughout the MLTT (P < 0.001). A linear increase in RPE during the MLTT was also observed (P < 0.001). POMS fatigue subscale scores accounted for 88 % of the variance in RPE during the MLTT (R(2) = 0.88, P = 0.002), and no other POMS subscale improved the final predictive model. With the exception of fatigue these results suggest that most aspects of mood do not have a discernable effect on RPE during a MLTT. The rate of increase in RPE can predict the MLTT endpoint. PMID:26242877

  10. Learning Activity Package, Physical Science. LAP Numbers 1, 2, 3, and 4.

    ERIC Educational Resources Information Center

    Williams, G. J.

    These four units of the Learning Activity Packages (LAPs) for individualized instruction in physical science cover measuring techniques, operations of instruments, metric system heat, matter, energy, elements, atomic numbers, isotopes, molecules, mixtures, compounds, physical and chemical properties, liquids, solids, and gases. Each unit contains…

  11. Learning Activity Package, American Civics 92, LAPs 1 Through 3 and 5 Through 9.

    ERIC Educational Resources Information Center

    Calhoun, B. C.

    This self paced program in American Civics is for the ninth grade student who needs help on basic skills and who plans to enroll in vocational or business courses. Instructional materials, written at 9th grade level, consist of eight Learning Activity Packages (LAPs) on the following topics: Citizenship and Our Democracy; The Constitution of the…

  12. The impact of layer thickness on the performance of additively manufactured lapping tools

    NASA Astrophysics Data System (ADS)

    Williams, Wesley B.

    2015-10-01

    Lower cost additive manufacturing (AM) machines which have emerged in recent years are capable of producing tools, jigs, and fixtures that are useful in optical fabrication. In particular, AM tooling has been shown to be useful in lapping glass workpieces. Various AM machines are distinguished by the processes, materials, build times, and build resolution they provide. This research investigates the impact of varied build resolution (specifically layer resolution) on the lapping performance of tools built using the stereolithographic assembly (SLA) process in 50 μm and 100 μm layer thicknesses with a methacrylate photopolymer resin on a high resolution desktop printer. As with previous work, the lapping tools were shown to remove workpiece material during the lapping process, but the tools themselves also experienced significant wear on the order of 2-3 times the mass loss of the glass workpieces. The tool wear rates for the 100 μm and 50 μm layer tools were comparable, but the 50 μm layer tool was 74% more effective at removing material from the glass workpiece, which is attributed to some abrasive particles being trapped in the coarser surface of the 100 um layer tooling and not being available to interact with the glass workpiece. Considering the tool wear, these additively manufactured tools are most appropriate for prototype tooling where the low cost (<$45) and quick turnaround make them attractive when compared to a machined tool.

  13. Learning Activity Package, Chemistry I. LAP Numbers 22, 23, 24, 25, 26, 27, and 28.

    ERIC Educational Resources Information Center

    Jones, Naomi

    As a set of seven Learning Activity Packages (LAPs) for individualized instruction in chemistry, the units cover the unit system, matter, energy, atomic structures, chemical formulas, physical states of matter, solutions and suspensions, ionization, acids, bases, and salts. Each unit contains a rationale for the material; a list of behavioral…

  14. 77 FR 27746 - Notice of Submission for OMB Review; Federal Student Aid; Lender Application Process (LAP)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-11

    ... Notice of Submission for OMB Review; Federal Student Aid; Lender Application Process (LAP) SUMMARY: The Lender's Application Process is submitted by lenders who are eligible for reimbursement of interest and special allowance, as well as Federal Insured Student Loan claims payment, under the Federal...

  15. Determination of Arsenic Poisoning and Metabolism in Hair by Synchrotron Radiation: The Case of Phar Lap

    SciTech Connect

    Kempson, Ivan M.; Henry, Dermot A.

    2010-08-26

    Fresh physical evidence about the demise of the racehorse Phar Lap (see photograph) has been gathered from the study of mane hair samples by synchrotron radiation analysis with high resolution X-ray fluorescence (XRF) and X-ray absorption near edge structure (XANES) analyses. The results are indicative of arsenic ingestion and metabolism, and show that the racing champion died from arsenic poisoning.

  16. Design Considerations of Polishing Lap for Computer-Controlled Cylindrical Polishing Process

    NASA Technical Reports Server (NTRS)

    Khan, Gufran S.; Gubarev, Mikhail; Arnold, William; Ramsey, Brian D.

    2009-01-01

    This paper establishes a relationship between the polishing process parameters and the generation of mid spatial-frequency error. The consideration of the polishing lap design to optimize the process in order to keep residual errors to a minimum and optimization of the process (speeds, stroke, etc.) and to keep the residual mid spatial-frequency error to a minimum, is also presented.

  17. Learning Activity Package, Algebra 103-104, LAPs 23-33.

    ERIC Educational Resources Information Center

    Evans, Diane

    This set of 11 teacher-prepared Learning Activity Packages (LAPs) in intermediate algebra covers number systems; exponents and radicals; polynomials and factoring; rational expressions; coordinate geometry; relations, functions, and inequalities; quadratic equations and inequalities; Quadratic functions; systems of equations and inequalities;…

  18. Progerin reduces LAP2α-telomere association in Hutchinson-Gilford progeria

    PubMed Central

    Chojnowski, Alexandre; Ong, Peh Fern; Wong, Esther SM; Lim, John SY; Mutalif, Rafidah A; Navasankari, Raju; Dutta, Bamaprasad; Yang, Henry; Liow, Yi Y; Sze, Siu K; Boudier, Thomas; Wright, Graham D; Colman, Alan; Burke, Brian; Stewart, Colin L; Dreesen, Oliver

    2015-01-01

    Hutchinson-Gilford progeria (HGPS) is a premature ageing syndrome caused by a mutation in LMNA, resulting in a truncated form of lamin A called progerin. Progerin triggers loss of the heterochromatic marker H3K27me3, and premature senescence, which is prevented by telomerase. However, the mechanism how progerin causes disease remains unclear. Here, we describe an inducible cellular system to model HGPS and find that LAP2α (lamina-associated polypeptide-α) interacts with lamin A, while its interaction with progerin is significantly reduced. Super-resolution microscopy revealed that over 50% of telomeres localize to the lamina and that LAP2α association with telomeres is impaired in HGPS. This impaired interaction is central to HGPS since increasing LAP2α levels rescues progerin-induced proliferation defects and loss of H3K27me3, whereas lowering LAP2 levels exacerbates progerin-induced defects. These findings provide novel insights into the pathophysiology underlying HGPS, and how the nuclear lamina regulates proliferation and chromatin organization. DOI: http://dx.doi.org/10.7554/eLife.07759.001 PMID:26312502

  19. Learning Activity Package, Algebra 93-94, LAPs 12-22.

    ERIC Educational Resources Information Center

    Evans, Diane

    A set of 11 teacher-prepared Learning Activity Packages (LAPs) in beginning algebra, these units cover sets, properties of operations, operations over real numbers, open expressions, solution sets of equations and inequalities, equations and inequalities with two variables, solution sets of equations with two variables, exponents, factoring and…

  20. Learning Activity Package, Physical Science. LAP Numbers 8, 9, 10, and 11.

    ERIC Educational Resources Information Center

    Williams, G. J.

    These four units of the Learning Activity Packages (LAPs) for individualized instruction in physical science cover nuclear reactions, alpha and beta particles, atomic radiation, medical use of nuclear energy, fission, fusion, simple machines, Newton's laws of motion, electricity, currents, electromagnetism, Oersted's experiment, sound, light,…

  1. Numerical study of the accumulation dynamics of oil shale thermal decomposition products in the vicinity of a heating element

    NASA Astrophysics Data System (ADS)

    Knyazeva, A. G.; Maslov, A. L.

    2015-10-01

    This study proposes the model of thermal decomposition of oil shale heated by electrodes. Differences in thermal physical properties of phases (solid core and gas, reagents and decomposition products), flow of generated gases in pores, and thermal effects of decomposition reactions are taken into account. The consideration of concentration expansion phenomenon is one of the features of the described model. The solution was carried out numerically. The concentration change of intermediate and final reaction products were studied for various heating conditions.

  2. Accumulation of Extracellular Matrix and Developmental Dysregulation in the Pancreas by Transgenic Production of Transforming Growth Factor-β1

    PubMed Central

    Lee, Myung-Shik; Gu, Danling; Feng, Lili; Curriden, Scott; Arnush, Marc; Krahl, Troy; Gurushanthaiah, Deepak; Wilson, Curtis; Loskutoff, David L.; Fox, Howard; Sarvetnick, Nora

    1995-01-01

    Transgenic mice expressing transforming growth factor-β1 (TGF-β1) in the pancreatic β-islet cells directed by human insulin promoter were produced to study in vivo effects of TGF-β1. Fibroblast proliferation and abnormal deposition of extracellular matrix were observed from birth onward, finally replacing almost all the exocrine pancreas. Cellular infiltrates comprising macrophages and neutrophils were also observed. Plasminogen activator inhibitor was induced in the transgenic pancreas as well as fibronectin and laminin, partly explaining accumulation of extracellular matrix. TGF-β1 inhibited proliferation of acinar cells in vivo as evidenced by decreased bromodeoxyuridine incorporation. Development of pancreatic islets was dysregulated, resulting in small islet cell clusters without formation of normal adult islets; however, the overall islet cell mass was not signfifcantly diminished. Additional transgenic lines with less pronounced phenotypes had less expression of TGF-β1 transgene. These findings suggest that TGF-β1 might be a mediator of diseases associated with extracellular matrix deposition such as chronic pancreatitis, and this mouse model will be useful for further analysis of the in vivo effects of TGF-β1, including its potential for immunosuppression. Imagesp43-aFigure 2Figure 3Figure 4Figure 5Figure 6 PMID:7604884

  3. The Characteristics of Fatigue Damage in the Fuselage Riveted Lap Splice Joint

    NASA Technical Reports Server (NTRS)

    Piascik, Robert S.; Willard, Scott A.

    1997-01-01

    An extensive data base has been developed to form the physical basis for new analytical methodology to predict the onset of widespread fatigue damage in the fuselage lap splice joint. The results of detailed destructive examinations have been cataloged to describe the physical nature of MSD in the lap splice joint. ne catalog includes a detailed description, e.g., crack initiation, growth rates, size, location, and fracture morphology, of fatigue damage in the fuselage lap splice joint structure. Detailed examinations were conducted on a lap splice joint panel removed from a full scale fuselage test article after completing a 60,000 cycle pressure test. The panel contained a four bay region that exhibited visible outer skin cracks and regions of crack link-up along the upper rivet row. Destructive examinations revealed undetected fatigue damage in the outer skin, inner skin, and tear strap regions. Outer skin fatigue cracks were found to initiate by fretting damage along the faying surface. The cracks grew along the faying surface to a length equivalent to two to three skin thicknesses before penetrating the outboard surface of the outer skin. Analysis of fracture surface marker bands produced during full scale testing revealed that all upper rivet row fatigue cracks contained in a dim bay region grow at similar rates; this important result suggests that fracture mechanics based methods can be used to predict the growth of outer skin fatigue cracks in lap splice structure. Results are presented showing the affects of MSD and out-of-plane pressure loads on outer skin crack link-up.

  4. Inhibition of Advanced Glycation End Products (AGEs) Accumulation by Pyridoxamine Modulates Glomerular and Mesangial Cell Estrogen Receptor α Expression in Aged Female Mice

    PubMed Central

    Xia, Xiaomei; Cai, Weijing; Choi, Rhea; Striker, Gary E.; Elliot, Sharon J.

    2016-01-01

    Age-related increases in oxidant stress (OS) play a role in regulation of estrogen receptor (ER) expression in the kidneys. In this study, we establish that in vivo 17β-estradiol (E2) replacement can no longer upregulate glomerular ER expression by 21 months of age in female mice (anestrous). We hypothesized that advanced glycation end product (AGE) accumulation, an important source of oxidant stress, contributes to these glomerular ER expression alterations. We treated 19-month old ovariectomized female mice with pyridoxamine (Pyr), a potent AGE inhibitor, in the presence or absence of E2 replacement. Glomerular ERα mRNA expression was upregulated in mice treated with both Pyr and E2 replacement and TGFβ mRNA expression decreased compared to controls. Histological sections of kidneys demonstrated decreased type IV collagen deposition in mice receiving Pyr and E2 compared to placebo control mice. In addition, anti-AGE defenses Sirtuin1 (SIRT1) and advanced glycation receptor 1 (AGER1) were also upregulated in glomeruli following treatment with Pyr and E2. Mesangial cells isolated from all groups of mice demonstrated similar ERα, SIRT1, and AGER1 expression changes to those of whole glomeruli. To demonstrate that AGE accumulation contributes to the observed age-related changes in the glomeruli of aged female mice, we treated mesangial cells from young female mice with AGE-BSA and found similar downregulation of ERα, SIRT1, and AGER1 expression. These results suggest that inhibition of intracellular AGE accumulation with pyridoxamine may protect glomeruli against age-related oxidant stress by preventing an increase of TGFβ production and by regulation of the estrogen receptor. PMID:27428057

  5. Transfer of skills on LapSim virtual reality laparoscopic simulator into the operating room in urology

    PubMed Central

    Alwaal, Amjad; Al-Qaoud, Talal M.; Haddad, Richard L.; Alzahrani, Tarek M.; Delisle, Josee; Anidjar, Maurice

    2015-01-01

    Objective: Assessing the predictive validity of the LapSim simulator within a urology residency program. Materials and Methods: Twelve urology residents at McGill University were enrolled in the study between June 2008 and December 2011. The residents had weekly training on the LapSim that consisted of 3 tasks (cutting, clip-applying, and lifting and grasping). They underwent monthly assessment of their LapSim performance using total time, tissue damage and path length among other parameters as surrogates for their economy of movement and respect for tissue. The last residents’ LapSim performance was compared with their first performance of radical nephrectomy on anesthetized porcine models in their 4th year of training. Two independent urologic surgeons rated the resident performance on the porcine models, and kappa test with standardized weight function was used to assess for inter-observer bias. Nonparametric spearman correlation test was used to compare each rater's cumulative score with the cumulative score obtained on the porcine models in order to test the predictive validity of the LapSim simulator. Results: The kappa results demonstrated acceptable agreement between the two observers among all domains of the rating scale of performance except for confidence of movement and efficiency. In addition, poor predictive validity of the LapSim simulator was demonstrated. Conclusions: Predictive validity was not demonstrated for the LapSim simulator in the context of a urology residency training program. PMID:25838162

  6. Accumulation of lipid production in Chlorella minutissima by triacylglycerol biosynthesis-related genes cloned from Saccharomyces cerevisiae and Yarrowia lipolytica.

    PubMed

    Hsieh, Hsin-Ju; Su, Chia-Hung; Chien, Liang-Jung

    2012-06-01

    Discovery of an alternative fuel is now an urgent matter because of the impending issue of oil depletion. Lipids synthesized in algal cells called triacylglycerols (TAGs) are thought to be of the most value as a potential biofuel source because they can use transesterification to manufacture biodiesel. Biodiesel is deemed as a good solution to overcoming the problem of oil depletion since it is capable of providing good performance similar to that of petroleum. Expression of several genomic sequences, including glycerol-3-phosphate dehydrogenase, glycerol-3-phosphate acyltransferase, lysophosphatidic acid acyltransferase, phosphatidic acid phosphatase, diacylglycerol acyltransferase, and phospholipid:diacylglycerol acyltransferase, can be useful for manipulating metabolic pathways for biofuel production. In this study, we found this approach indeed increased the storage lipid content of C. minutissima UTEX 2219 up to 2-fold over that of wild type. Thus, we conclude this approach can be used with the biodiesel production platform of C. minutissima UTEX 2219 for high lipid production that will, in turn, enhance productivity. PMID:22752918

  7. Petrography of Lunar Meteorite LAP 02205, a New Low-Ti Basalt Possibly Launch Paired with NWA 032

    NASA Technical Reports Server (NTRS)

    Jolliff, B. L.; Zeigler, R. A.; Korotev, R. L.

    2004-01-01

    Lunar meteorite LAP 02205 is a 1.23 kg basalt collected during the 2002 field season in the La- Paz ice field, Antarctica [1]. We present a petrographic description including mineral modes and compositions, and the major-element composition of the bulk meteorite. LAP 02205 is an Fe-rich, moderately low-Ti mare basalt that is similar in composition, mineralogy, and mineral chemistry to the NWA 032 basaltic lunar meteorite. LAP 02205 is yet another of the moderately low- Ti basaltic meteorites that are underrepresented among Apollo and Luna samples but that appear from remote sensing to be the most common basalt type on the Moon.

  8. Hydrogen sulfide production during yeast fermentation causes the accumulation of ethanethiol, S-ethyl thioacetate and diethyl disulfide.

    PubMed

    Kinzurik, Matias I; Herbst-Johnstone, Mandy; Gardner, Richard C; Fedrizzi, Bruno

    2016-10-15

    Hydrogen sulfide (H2S) is produced by yeast during winemaking and possesses off-flavors reminiscent of rotten eggs. The production of H2S during fermentation has also been associated in the finished wine with the rise of additional volatile sulfur compounds (VSCs) with strong aromas of cooked onions and vegetables. To characterize these more complex VSCs produced from H2S, we performed fermentations in synthetic grape juice. H2S production was manipulated experimentally by feeding increasing concentrations of sulfate to mutant strains that are unable to incorporate H2S efficiently as part of the sulfur assimilation pathway. In finished wines from these mutants, three VSCs - ethanethiol, S-ethyl thioacetate and diethyl disulfide - increased proportionally to H2S. (34)S-labeled sulfate fed to the MET17-deleted strain was incorporated into same three VSCs, demonstrating that they are formed directly from H2S. PMID:27173572

  9. Enhanced energy conversion efficiency from high strength synthetic organic wastewater by sequential dark fermentative hydrogen production and algal lipid accumulation.

    PubMed

    Ren, Hong-Yu; Liu, Bing-Feng; Kong, Fanying; Zhao, Lei; Xing, Defeng; Ren, Nan-Qi

    2014-04-01

    A two-stage process of sequential dark fermentative hydrogen production and microalgal cultivation was applied to enhance the energy conversion efficiency from high strength synthetic organic wastewater. Ethanol fermentation bacterium Ethanoligenens harbinense B49 was used as hydrogen producer, and the energy conversion efficiency and chemical oxygen demand (COD) removal efficiency reached 18.6% and 28.3% in dark fermentation. Acetate was the main soluble product in dark fermentative effluent, which was further utilized by microalga Scenedesmus sp. R-16. The final algal biomass concentration reached 1.98gL(-1), and the algal biomass was rich in lipid (40.9%) and low in protein (23.3%) and carbohydrate (11.9%). Compared with single dark fermentation stage, the energy conversion efficiency and COD removal efficiency of two-stage system remarkably increased 101% and 131%, respectively. This research provides a new approach for efficient energy production and wastewater treatment using a two-stage process combining dark fermentation and algal cultivation. PMID:24582427

  10. Age-related accumulation of advanced glycation end-products-albumin, S100β, and the expressions of advanced glycation end product receptor differ in visceral and subcutaneous fat.

    PubMed

    Son, Kuk Hui; Son, Myeongjoo; Ahn, Hyosang; Oh, Seyeon; Yum, Yoonji; Choi, Chang Hu; Park, Kook Yang; Byun, Kyunghee

    2016-08-19

    Visceral fat induces more inflammation by activating macrophages than subcutaneous fat, and inflammation is an underlying feature of the pathogeneses of various diseases, including cardiovascular disease and diabetes. Advanced glycation end products (AGEs), S100β, and their receptors, the receptor for advanced glycation end products (RAGE), lead to macrophage activation. However, little information is available regarding the differential accumulations of AGE-albumin (serum albumin modified by AGEs), S100β, or expressions of RAGE in different adipocyte types in fat tissues. In this study, the authors investigated whether age-related AGE-albumin accumulations S100β level, and RAGE expressions differ in subcutaneous and visceral fat tissues. Subcutaneous and visceral fat were harvested from 3- and 28-week-old rats. Macrophage activation was confirmed by Iba1 staining, and AGE-albumin accumulations and RAGE expressions were assessed by confocal microscopy. S100β were analyzed by immunoblotting. It was found that activated macrophage infiltration, AGE-albumin accumulation, and S100β in visceral fat was significantly greater in 28-week-old rats than in 3-week-old rats, but similar in subcutaneous fat. The expression of RAGE in visceral fat was much greater in 28-week-old rats, but its expression in subcutaneous fat was similar in 3- and 28-week-old rats. Furthermore, inflammatory signal pathways (NFκB, TNF-α) and proliferation pathways (FAK) in visceral fat were more activated in 28-week-old rats. These results imply that age-related AGE-albumin accumulation, S100β, and RAGE expression are more prominent in visceral than in subcutaneous fat, suggesting that visceral fat is involved in the pathogenesis of inflammation-induced diseases in the elderly. PMID:27301641

  11. Use of Information Theory Concepts for Developing Contaminated Site Detection Method: Case for Fission Product and Actinides Accumulation Modeling

    SciTech Connect

    Harbachova, N.V.; Sharavarau, H.A.

    2006-07-01

    Information theory concepts and their fundamental importance for environmental pollution analysis in light of experience of Chernobyl accident in Belarus are discussed. An information and dynamic models of the radionuclide composition formation in the fuel of the Nuclear Power Plant are developed. With the use of code DECA numerical calculation of actinides (58 isotopes are included) and fission products (650 isotopes are included) activities has been carried out and their dependence with the fuel burn-up of the RBMK-type reactor have been investigated. (authors)

  12. Increased growth and root Cu accumulation of Sorghum sudanense by endophytic Enterobacter sp. K3-2: Implications for Sorghum sudanense biomass production and phytostabilization.

    PubMed

    Li, Ya; Wang, Qi; Wang, Lu; He, Lin-Yan; Sheng, Xia-Fang

    2016-02-01

    Endophytic bacterial strain K3-2 was isolated from the roots of Sorghum sudanense (an bioenergy plant) grown in a Cu mine wasteland soils and characterized. Strain K3-2 was identified as Enterobacter sp. based on 16S rRNA gene sequence analysis. Strain K3-2 exhibited Cu resistance and produced 1-aminocyclopropane-1-carboxylate (ACC) deaminase, indole-3-acetic acid (IAA), siderophores, and arginine decarboxylase. Pot experiments showed that strain K3-2 significantly increased the dry weight and root Cu accumulation of Sorghum sudanense grown in the Cu mine wasteland soils. Furthermore, increase in total Cu uptake (ranging from 49% to 95%) of the bacterial inoculated-Sorghum sudanense was observed compared to the control. Notably, most of Cu (83-86%) was accumulated in the roots of Sorghum sudanense. Furthermore, inoculation with strain K3-2 was found to significantly increase Cu bioconcentration factors and the proportions of IAA- and siderophore-producing bacteria in the root interiors and rhizosphere soils of Sorghum sudanense compared with the control. Significant decrease in the available Cu content was also observed in the rhizosphere soils of the bacterial-inoculated Sorghum sudanense. The results suggest that the endophytic bacterial strain K3-2 may be exploited for promoting Sorghum sudanense biomass production and Cu phytostabilization in the Cu mining wasteland soils. PMID:26517728

  13. Efficient polyhydroxyalkanoate (PHA) accumulation by a new continuous feeding mode in three-stage mixed microbial culture (MMC) PHA production process.

    PubMed

    Chen, Zhiqiang; Huang, Long; Wen, Qinxue; Guo, Zirui

    2015-09-10

    A new continuous feeding mode was developed to optimize the polyhydroxyalkanoates (PHAs) accumulation step in the three-stage PHAs production process by mixed microbial cultures (MMCs) using mixed volatile fatty acids (VFAs) as substrate. The continuous feeding assays under low biomass loading rate (BLR) (in the range of 3.5-5.5Cmol VFA/Cmol X/d) can be directly fed with feedstock with pH from 5.0 to 10.0 without any pH regulation. The maximum intracellular PHA content of 70.4% and system PHA yield (YPHA/S(sys)) of 0.81Cmol PHA/Cmol VFA were achieved under the continuous feeding mode at BLR of 3.86Cmol VFA/Cmol X/d when directly fed with substrate at pH 5. These values were higher than those under the pulse wise feeding mode with the same substrate and active biomass concentration. The results indicated that a self-balanced pH state was formed in the continuous feeding system. Further studies on the reaction pH and kinetics of the MMCs in the continuous feeding reactor were conducted to understand the pH variation mechanism and accumulation process. The optimal BLR to get high PHA content and YPHA/S(sys) was 3.5-5.5Cmol VFA/Cmol X/d. PMID:26073996

  14. A record of barite accumulation rate for marine export productivity changes in the tropical Indian Ocean during the Mid-Pliocene--Early-Pleistocene transition

    NASA Astrophysics Data System (ADS)

    Zhou, Liping; Ma, Zhongwu; Ding, Xuan

    2016-04-01

    One of the most interesting features in the marine oxygen isotope records is the gradual shift towards heavier 18O from the Mid-Pliocene, which ends with the initiation of Northern Hemisphere glaciation (NHG) around 2.7 Ma. The lack of significant change in sea surface temperature in the tropical Indian Ocean as revealed in the previous studies does not rule out their possible contributions to this dramatic climate change during the Mid-Pliocene transition. Changing circulation systems in the region will control the supply of nutrients for the water masses which in turn determine the marine productivity. In the areas of high productivity, ocean export productivity may potentially provide a mechanism of CO2 draw-down into the deep ocean, through which contributing to the lowering of the global temperature. In this study, we present a record of barite accumulation rate (BAR) for DSDP Site 214 drilled on the Ninetyeast Ridge. Here we use the marine barite, which is formed during the decay of organism in the twilight zone, as a proxy for ocean export productivity. Our results show that the BAR of Site 214 varies between 0.25 and 1.25 mg/cm2/kyr during the period between 4 Ma and 2 Ma. Five intervals of increased BAR from 3.6 Ma to 2.4 Ma are identified with the most distinct peak centred around 3 Ma. The overall pattern does not follow either the oxygen isotope record for the Site or the sea surface temperature and subsurface temperature reconstructed with the Mg/Ca of foraminifera. This suggests that regional changes in ocean circulation and water masses may have played more important role than temperature in controlling the productivity change in the tropical Indian Ocean. The relative higher productivity around 3 Ma may imply a biogenetic process towards the intensification of NHGs.

  15. Identification of QTLs influencing alcohol preference in the High Alcohol Preferring (HAP) and Low Alcohol Preferring (LAP) mouse lines.

    PubMed

    Bice, Paula J; Foroud, Tatiana; Carr, Lucinda G; Zhang, Lili; Liu, Lixiang; Grahame, Nicholas J; Lumeng, Lawrence; Li, Ting-Kai; Belknap, John K

    2006-03-01

    The High- and Low-Alcohol Preferring (HAP1/LAP1 and HAP2/LAP2) mouse lines were developed by selective breeding for differences in alcohol preference. They represent the only extant selectively bred mouse lines developed for this alcohol phenotype. Therefore, they provide a unique resource for QTL detection and mapping. Importantly, neither of the replicate lines is inbred and therefore, novel study designs can be employed to detect loci contributing to alcohol preference. Two independent studies, with very different approaches, were conducted in the HAP and LAP replicate lines. In Study 1, microsatellite markers were genotyped in the replicate HAP1/LAP1 and HAP2/LAP2 mice in QTL regions nominated by other mouse RI and F2 studies in order to detect divergence of allele frequencies in the two oppositely selected lines. Significant differences in allele frequencies were observed in the HAP1/LAP1 mice with markers on chromosome 9 (p<0.01). In the HAP2/LAP2 mice, significant differences in allele frequencies were identified on chromosomes 2 and 9 (p<0.01). In Study 2, a genome-wide screen was performed in a sample of 432 HAP1xLAP1 F2 animals and a QTL on chromosome 9 (LOD=5.04) was found which met criteria for genome wide significance (p<0.001). Gender specific analyses supported a greater effect of the QTL among female mice (LOD=5.19; p<0.0008) than male mice (LOD=1.19). This study provides additional evidence and confirmation that specific regions on chromosomes 9 and perhaps 2 are important for alcohol preference. PMID:16482403

  16. A critical examination of stresses in an elastic single lap joint

    NASA Technical Reports Server (NTRS)

    Cooper, P. A.; Sawyer, J. W.

    1979-01-01

    The results of an approximate nonlinear finite-element analysis of a single lap joint are presented and compared with the results of a linear finite-element analysis, and the geometric nonlinear effects caused by the load-path eccentricity on the adhesive stress distributions are determined. The results from finite-element, Goland-Reissner, and photoelastic analyses show that for a single lap joint the effect of the geometric nonlinear behavior of the joint has a sizable effect on the stresses in the adhesive. The Goland-Reissner analysis is sufficiently accurate in the prediction of stresses along the midsurface of the adhesive bond to be used for qualitative evaluation of the influence of geometric or material parametric variations. Detailed stress distributions in both the adherend and adhesive obtained from the finite-element analysis are presented to provide a basis for comparison with other solution techniques.

  17. A Practical Engineering Approach to Predicting Fatigue Crack Growth in Riveted Lap Joints

    NASA Technical Reports Server (NTRS)

    Harris, C. E.; Piascik, R. S.; Newman, J. C., Jr.

    2000-01-01

    An extensive experimental database has been assembled from very detailed teardown examinations of fatigue cracks found in rivet holes of fuselage structural components. Based on this experimental database, a comprehensive analysis methodology was developed to predict the onset of widespread fatigue damage in lap joints of fuselage structure. Several computer codes were developed with specialized capabilities to conduct the various analyses that make up the comprehensive methodology. Over the past several years, the authors have interrogated various aspects of the analysis methods to determine the degree of computational rigor required to produce numerical predictions with acceptable engineering accuracy. This study led to the formulation of a practical engineering approach to predicting fatigue crack growth in riveted lap joints. This paper describes the practical engineering approach and compares predictions with the results from several experimental studies.

  18. A Practical Engineering Approach to Predicting Fatigue Crack Growth in Riveted Lap Joints

    NASA Technical Reports Server (NTRS)

    Harris, Charles E.; Piascik, Robert S.; Newman, James C., Jr.

    1999-01-01

    An extensive experimental database has been assembled from very detailed teardown examinations of fatigue cracks found in rivet holes of fuselage structural components. Based on this experimental database, a comprehensive analysis methodology was developed to predict the onset of widespread fatigue damage in lap joints of fuselage structure. Several computer codes were developed with specialized capabilities to conduct the various analyses that make up the comprehensive methodology. Over the past several years, the authors have interrogated various aspects of the analysis methods to determine the degree of computational rigor required to produce numerical predictions with acceptable engineering accuracy. This study led to the formulation of a practical engineering approach to predicting fatigue crack growth in riveted lap joints. This paper describes the practical engineering approach and compares predictions with the results from several experimental studies.

  19. Material characterization of structural adhesives in the lap shear mode. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Schenck, S. C.; Sancaktar, E.

    1983-01-01

    A general method for characterizing structural adhesives in the bonded lap shear mode is proposed. Two approaches in the form of semi-empirical and theoretical approaches are used. The semi-empirical approach includes Ludwik's and Zhurkov's equations to describe respectively, the failure stresses in the constant strain rate and constant stress loading modes with the inclusion of the temperature effects. The theoretical approach is used to describe adhesive shear stress-strain behavior with the use of viscoelastic or nonlinear elastic constitutive equations. Three different model adhesives are used in the simple lap shear mode with titanium adherends. These adhesives (one of which was developed at NASA Langley Research Center) are currently considered by NASA for possible aerospace applications. Use of different model adhesives helps in assessment of the generality of the method.

  20. Experimental study of non-linear effects in a typical shear lap joint configuration

    NASA Astrophysics Data System (ADS)

    Hartwigsen, C. J.; Song, Y.; McFarland, D. M.; Bergman, L. A.; Vakakis, A. F.

    2004-10-01

    Although mechanical joints are integral parts of most practical structures, their modelling and their effects on structural dynamics are not yet fully understood. This represents a serious impediment to accurate modelling of the dynamics and to the development of reduced-order, finite element models capable of describing the effects of mechanical joints on the dynamics. In this work we provide an experimental study to quantify the non-linear effects of a typical shear lap joint on the dynamics of two structures: a beam with a bolted joint in its center; and a frame with a bolted joint in one of its members. Both structures are subjected to a variety of dynamical tests to determine the non-linear effects of the joints. The tests reveal several important influences on the effective stiffness and damping of the lap joints. The possibility of using Iwan models to represent the experimentally observed joint effects is discussed.

  1. Investigation of defect rate of lap laser welding of stainless steel railway vehicles car body

    NASA Astrophysics Data System (ADS)

    Wang, Hongxiao

    2015-02-01

    In order to resolve the disadvantages such as poor appearance quality, poor tightness, low efficiency of resistance spot welding of stainless steel rail vehicles, partial penetration lap laser welding process was investigated widely. But due to the limitation of processing technology, there will be local incomplete fusion in the lap laser welding seam. Defect rate is the ratio of the local incomplete fusion length to the weld seam length. The tensile shear strength under different defect rate and its effect on the car body static strength are not clear. It is necessary to find the biggest defect rate by numerical analysis of effects of different defect rates on the laser welding stainless steel rail vehicle body structure strength ,and tests of laser welding shear tensile strength.

  2. Ground based experiments on the growth and characterization of L-Arginine Phosphate (LAP) crystals

    NASA Technical Reports Server (NTRS)

    Rao, S. M.; Cao, C.; Batra, A. K.; Lal, R. B.; Mookherji, T. K.

    1991-01-01

    L-Arginine Phosphate (LAP) is a new nonlinear optical material with higher efficiency for harmonic generation compared to KDP. Crystals of LAP were grown in the laboratory from supersaturated solutions by temperature lowering technique. Investigations revealed the presence of large dislocation densities inside the crystals which are observed to produce refractive index changes causing damage at high laser powers. This is a result of the convection during crystal growth from supersaturated solutions. It is proposed to grow these crystals in a diffusion controlled growth condition under microgravity environment and compare the crystals grown in space with those grown on ground. Physical properties of the solutions needed for modelling of crystal growth are also presented.

  3. Boosting TAG Accumulation with Improved Biodiesel Production from Novel Oleaginous Microalgae Scenedesmus sp. IITRIND2 Utilizing Waste Sugarcane Bagasse Aqueous Extract (SBAE).

    PubMed

    Arora, Neha; Patel, Alok; Pruthi, Parul A; Pruthi, Vikas

    2016-09-01

    This investigation utilized sugarcane bagasse aqueous extract (SBAE), a nontoxic, cost-effective medium to boost triacylglycerol (TAG) accumulation in novel fresh water microalgal isolate Scenedesmus sp. IITRIND2. Maximum lipid productivity of 112 ± 5.2 mg/L/day was recorded in microalgae grown in SBAE compared to modified BBM (26 ± 3 %). Carotenoid to chlorophyll ratio was 12.5 ± 2 % higher than in photoautotrophic control, indicating an increase in photosystem II activity, thereby increasing growth rate. Fatty acid methyl ester (FAME) profile revealed presence of C14:0 (2.29 %), C16:0 (15.99 %), C16:2 (4.05 %), C18:0 (3.41 %), C18:1 (41.55 %), C18:2 (12.41), and C20:0 (1.21 %) as the major fatty acids. Cetane number (64.03), cold filter plugging property (-1.05 °C), and oxidative stability (12.03 h) indicated quality biodiesel abiding by ASTM D6751 and EN 14214 fuel standards. Results consolidate the candidature of novel freshwater microalgal isolate Scenedesmus sp. IITRIND2 cultivated in SBAE, aqueous extract made from copious, agricultural waste sugarcane bagasse to increase the lipid productivity, and could further be utilized for cost-effective biodiesel production. PMID:27093970

  4. Early evolution of comet 67P studied with the RPC-LAP onboard Rosetta

    NASA Astrophysics Data System (ADS)

    Miloch, Wojciech; Edberg, Niklas J. T.; Eriksson, Anders I.; Yang, Lei; Paulsson, Joakim J. P.; Wedlund, Cyril Simon; Odelstad, Elias

    2016-07-01

    The Rosetta mission provides the in-situ measurements of a comet that are closest to a comet's aphelion ever made. The Rosetta Plasma Consortium (RPC) is a set of five instruments on board the spacecraft that specialise in the measurements of the plasma environment of comet 67P. One of the instruments is RPC-LAP, which consists of two Langmuir Probes and can measure the density, temperature, and flow speed of the plasma in the vicinity of the comet. At the early stage of the Rosetta mission, when the spacecraft is far from the nucleus of comet 67P, the ion part of the current-voltage characteristics of RPC-LAP1 is dominated by the photoemission current which surpasses the currents from the dilute solar wind plasma. As Rosetta starts orbiting around the nucleus in September 2014, LAP1 picks up signatures of local plasma density enhancements corresponding to variations of water-group ions observed in the vicinity of the comet. With the help of current-voltage characteristics and the spacecraft potential, we identify and characterise in space and time the entering of this coma-dominated plasma. In particular we determine the transition for entering the ion dominated region characterised by the 6-hour variations in the local plasma density due to the comet rotation. This transition manifests as a steep gradient in the density with respect to the distance to the comet nucleus. We discuss these RPC-LAP results together with the corresponding measurements by other instruments to provide a comprehensive picture of the transition.

  5. Spatial distribution of low energy plasma at comet 67P from Rosetta RPC-LAP measurements

    NASA Astrophysics Data System (ADS)

    Edberg, Niklas J. T.; Eriksson, Anders I.; Odelstad, Elias; Vigren, Erik; Henri, Pierre; Lebreton, Jean-Pierre; Mandt, Kathleen; Nilsson, Hans; Carr, Chris; Cupido, Emanuele; Vallat, Claire; Altwegg, Kathrin

    2015-04-01

    We present in situ measurements of the low energy plasma environment around comet 67P from the two Langmuir probes (LAP) on the Rosetta spacecraft, which form part of the Rosetta plasma consortium (RPC). RPC-LAP has operated almost continuously as Rosetta has orbited the comet at close distance (10-30 km) at low velocity (about 1 m/s) since August 2014. Using the RPC-LAP measurements we have produced global maps of the low energy plasma in the vicinity of 67P. Initial estimates indicate that the plasma density has reached values of several 100 cm^-3 and that the electron temperature has typically been in the range 5-10 eV, when the comet was beyond 2.5 AU from the sun. Photoionisation is the dominating process for producing the plasma around the comet while charge-exchange and impact ionisation may also contribute. The plasma environment has been found to be strongly coupled to the local neutral gas density, which in turn is coupled to which area on the comet is facing the sun. The northern summer neck-area of the comet outgasses more than other areas and above this region are the highest densities observed. In the southern winter and above the two main lobes of the comet body, the plasma density is lower. The plasma density is hence not determined by the solar wind, but by the outgassing from the comet. The 12.4-hour rotation period of the comet together with the varying latitude of the slow-moving Rosetta provide strong modulation of the RPC-LAP measurements. Besides orbiting the comet, Rosetta will also perform flybys of the comet in early 2015 when Rosetta will move to distances of several hundred kilometres from the nucleus. These flybys provide a cut-through view of the near-comet plasma environment, which will possibly give some insight to the solar-wind interaction with the cometary coma.

  6. A Single-Lap Joint Adhesive Bonding Optimization Method Using Gradient and Genetic Algorithms

    NASA Technical Reports Server (NTRS)

    Smeltzer, Stanley S., III; Finckenor, Jeffrey L.

    1999-01-01

    A natural process for any engineer, scientist, educator, etc. is to seek the most efficient method for accomplishing a given task. In the case of structural design, an area that has a significant impact on the structural efficiency is joint design. Unless the structure is machined from a solid block of material, the individual components which compose the overall structure must be joined together. The method for joining a structure varies depending on the applied loads, material, assembly and disassembly requirements, service life, environment, etc. Using both metallic and fiber reinforced plastic materials limits the user to two methods or a combination of these methods for joining the components into one structure. The first is mechanical fastening and the second is adhesive bonding. Mechanical fastening is by far the most popular joining technique; however, in terms of structural efficiency, adhesive bonding provides a superior joint since the load is distributed uniformly across the joint. The purpose of this paper is to develop a method for optimizing single-lap joint adhesive bonded structures using both gradient and genetic algorithms and comparing the solution process for each method. The goal of the single-lap joint optimization is to find the most efficient structure that meets the imposed requirements while still remaining as lightweight, economical, and reliable as possible. For the single-lap joint, an optimum joint is determined by minimizing the weight of the overall joint based on constraints from adhesive strengths as well as empirically derived rules. The analytical solution of the sin-le-lap joint is determined using the classical Goland-Reissner technique for case 2 type adhesive joints. Joint weight minimization is achieved using a commercially available routine, Design Optimization Tool (DOT), for the gradient solution while an author developed method is used for the genetic algorithm solution. Results illustrate the critical design variables

  7. Low frequency ultrasonic nondestructive inspection of aluminum/adhesive fuselage lap splices

    SciTech Connect

    Patton, T.

    1994-01-04

    This thesis is a collection of research efforts in ultrasonics, conducted at the Center for Aviation Systems Reliability located at Iowa State University, as part of the Federal Aviation Administration`s ``Aging Aircraft Program.`` The research was directed toward the development of an ultrasonic prototype to inspect the aluminum/adhesive fuselage lap splices found on 1970`s vintage Boeing passenger aircraft. The ultrasonic prototype consists of a normal incidence, low frequency inspection technique, and a scanning adapter that allows focused immersion transducers to be operated in a direct contact manner in any inspection orientation, including upside-down. The inspection technique uses a computer-controlled data acquisition system to produce a C-scan image of a radio frequency (RF) waveform created by a low frequency, broadband, focused beam transducer, driven with a spike voltage pulser. C-scans produced by this technique are color representations of the received signal`s peak-to-peak amplitude (voltage) taken over an (x, y) grid. Low frequency, in this context, refers to a wavelength that is greater than the lap splice`s layer thicknesses. With the low frequency technique, interface echoes of the lap splice are not resolved and gating of the signal is unnecessary; this in itself makes the technique simple to implement and saves considerable time in data acquisition. Along with the advantages in data acquisition, the low frequency technique is relatively insensitive to minor surface curvature and to ultrasonic interference effects caused by adhesive bondline thickness variations in the lap splice.

  8. Evaluation of the fuselage lap joint fatigue and terminating action repair

    NASA Technical Reports Server (NTRS)

    Samavedam, Gopal; Thomson, Douglas; Jeong, David Y.

    1994-01-01

    Terminating action is a remedial repair which entails the replacement of shear head countersunk rivets with universal head rivets which have a larger shank diameter. The procedure was developed to eliminate the risk of widespread fatigue damage (WFD) in the upper rivet row of a fuselage lap joint. A test and evaluation program has been conducted by Foster-Miller, Inc. (FMI) to evaluate the terminating action repair of the upper rivet row of a commercial aircraft fuselage lap splice. Two full scale fatigue tests were conducted on fuselage panels using the growth of fatigue cracks in the lap joint. The second test was performed to evaluate the effectiveness of the terminating action repair. In both tests, cyclic pressurization loading was applied to the panels while crack propagation was recorded at all rivet locations at regular intervals to generate detailed data on conditions of fatigue crack initiation, ligament link-up, and fuselage fracture. This program demonstrated that the terminating action repair substantially increases the fatigue life of a fuselage panel structure and effectively eliminates the occurrence of cracking in the upper rivet row of the lap joint. While high cycle crack growth was recorded in the middle rivet row during the second test, failure was not imminent when the test was terminated after cycling to well beyond the service life. The program also demonstrated that the initiation, propagation, and linkup of WFD in full-scale fuselage structures can be simulated and quantitatively studied in the laboratory. This paper presents an overview of the testing program and provides a detailed discussion of the data analysis and results. Crack distribution and propagation rates and directions as well as frequency of cracking are presented for both tests. The progression of damage to linkup of adjacent cracks and to eventual overall panel failure is discussed. In addition, an assessment of the effectiveness of the terminating action repair and the

  9. Large-scale Advanced Prop-fan (LAP) static rotor test report

    NASA Technical Reports Server (NTRS)

    Degeorge, Charles L.; Turnberg, Jay E.; Wainauski, Harry S.

    1987-01-01

    Discussed is Static Rotor Testing of the SR-7L Large Scale Advanced Prop-Fan (LAP). The LAP is an advanced 9 foot diameter, 8 bladed propeller designed and built by Hamilton Standard under contract to the NASA Lewis Research Center. The Prop-Fan employs thin swept blades to provide efficient propulsion at flight speeds up to Mach .85. Static Testing was conducted on a 10,000 HP whirl rig at Wright Patterson Air Force Base. The test objectives were to investigate the Prop-Fan static aerodynamic and structural dynamic performance, determine the blade steady state stressers and deflections and to measure steady and unsteady pressures on the SR-7L blade surface. The measured performance of the LAP correlated well with analytical predictions at blade pitch angles below 30 deg. A stall buffet phenomenon was observed at blade pitch angles above 30 deg. This phenomenon manifested itself by elevated blade vibratory stress levels and lower than expected thrust produced and power absorbed by the Prop-Fan for a given speed and blade angle.

  10. Behavior Of A Confined Tension Lap Splice In High-Strength Reinforced Concrete Beams

    NASA Astrophysics Data System (ADS)

    Abdel-Kareem, Ahmed H.; Abousafa, Hala; El-Hadidi, Omaia S.

    2015-09-01

    The results of an experimental program conducted on seventeen simply supported concrete beams to study the effect of transverse reinforcement on the behavior of the lap splice of a steel reinforcement in tension zones in high-strength concrete beams are presented. The parameters included in the experimental program were the concrete compressive strength, the lap splice length, the amount of transverse reinforcement provided within the splice region, and the shape of the transverse reinforcement around the spliced bars. The experimental results showed that the displacement ductility increased and the mode of failure changed from a splitting bond failure to a flexural failure when the amount of the transverse reinforcement in the splice region increased, and the compressive strength increased up to 100 MPa. The presence of the transverse reinforcement around the spliced bars had a pronounced effect on increasing the ultimate load, the ultimate deflection, and the displacement ductility. The prediction of maximum steel stresses for spliced bars using the ACI 318-05 building code was compared with the experimental results. The comparison showed that the effect of the transverse reinforcement around spliced bars has to be considered into the design equations for lap splice length in high-strength concrete beams.

  11. Enhancing pulsed eddy current for inspection of P-3 Orion lap-joint structures

    NASA Astrophysics Data System (ADS)

    Butt, D. M.; Underhill, P. R.; Krause, T. W.

    2016-02-01

    During flight, aircraft are subjected to cyclic loading. In the Lockheed P-3 Orion airframe, this cyclic loading can lead to development of fatigue cracks at steel fastener locations in the top and second layers of aluminum wing skin lap-joints. An inspection method that is capable of detecting these cracks, without fastener removal, is desirable as this can minimize aircraft downtime, while subsequently reducing the risk of collateral damage. The ability to detect second layer cracks has been demonstrated using a Pulsed Eddy Current (PEC) probe design that utilizes the ferrous fastener as a flux conduit. This allows for deeper penetration of flux into the lap-joint second layer and consequently, sensitivity to the presence of cracks. Differential pick-up coil pairs are used to sense the eddy current response due to the presence of a crack. The differential signal obtained from pick-up coils on opposing sides of the fastener is analyzed using a Modified Principal Components Analysis (MPCA). This is followed by a cluster analysis of the resulting MPCA scores to separate fastener locations with cracks from those without. Probe design features, data acquisition system parameters and signal post-processing can each have a strong impact on crack detection. Physical probe configurations and signal analysis processes, used to enhance the PEC system for detection of cracks in P-3 Orion lap-joint structures, are investigated and an enhanced probe design is identified.

  12. Conventional box model training improves laparoscopic skills during salpingectomy on LapSim: a randomized trial

    PubMed Central

    Akdemir, Ali; Ergenoğlu, Ahmet Mete; Yeniel, Ahmet Özgür; Şendağ, Fatih

    2013-01-01

    Objective Box model trainers have been used for many years to facilitate the improvement of laparoscopic skills. However, there are limited data available on box trainers and their impact on skill acquisition, assessed by virtual reality systems. Material and Methods Twenty-two Postgraduate Year 1 gynecology residents with no laparoscopic experience were randomly divided into one group that received structured box model training and a control group. All residents performed a salpingectomy on LapSim before and after the training. Performances before and after the training were assessed using LapSim and were recorded using objective parameters, registered by a computer system (time, damage, and economy of motion scores). Results There were initially no differences between the two groups. The box trainer group showed significantly greater improvement in time (p=0.01) and economy of motion scores (p=0.001) compared with the control group post-training. Conclusion The present study confirmed the positive effect of low cost box model training on laparoscopic skill acquisition as assessed using LapSim. Novice surgeons should obtain practice on box trainers and teaching centers should make efforts to establish training laboratories. PMID:24592096

  13. Optimum design of bolted composite lap joints under mechanical and thermal loading

    NASA Astrophysics Data System (ADS)

    Kradinov, Vladimir Yurievich

    A new approach is developed for the analysis and design of mechanically fastened composite lap joints under mechanical and thermal loading. Based on the combined complex potential and variational formulation, the solution method satisfies the equilibrium equations exactly while the boundary conditions are satisfied by minimizing the total potential. This approach is capable of modeling finite laminate planform dimensions, uniform and variable laminate thickness, laminate lay-up, interaction among bolts, bolt torque, bolt flexibility, bolt size, bolt-hole clearance and interference, insert dimensions and insert material properties. Comparing to the finite element analysis, the robustness of the method does not decrease when modeling the interaction of many bolts; also, the method is more suitable for parametric study and design optimization. The Genetic Algorithm (GA), a powerful optimization technique for multiple extrema functions in multiple dimensions search spaces, is applied in conjunction with the complex potential and variational formulation to achieve optimum designs of bolted composite lap joints. The objective of the optimization is to acquire such a design that ensures the highest strength of the joint. The fitness function for the GA optimization is based on the average stress failure criterion predicting net-section, shear-out, and bearing failure modes in bolted lap joints. The criterion accounts for the stress distribution in the thickness direction at the bolt location by applying an approach utilizing a beam on an elastic foundation formulation.

  14. Probabilistic seismic performance assessment of lap-spliced RC columns retrofitted by steel wrapping jackets

    NASA Astrophysics Data System (ADS)

    Choi, Eunsoo; Youn, Heejung; Cho, Baik-Soon

    2016-06-01

    In this study, the seismic fragility curves of two reinforced concrete (RC) columns that were lap-spliced at the bottom and retrofitted with steel wrapping jackets were generated. Their seismic performance was probabilistically assessed in comparison to that of lap-spliced or continuous reinforcement RC columns. This study used two types of steel wrapping jackets, a full jacket and a split jacket. Analytical models of the four types of columns were developed based on the experimental results of the columns using OpenSEES, which is effective in conducting nonlinear time history analyses. A suite of ten artificial ground motions, modified from recorded ground motions, was used to perform nonlinear time history analyses of the analytical models with scaling of the peak ground acceleration from 0.1 g to 1.0 g in increments of 0.1 g. The steel wrapping jackets did not increase the medians for yield (slight damage state) of the lap-spiced column and did not exceed the corresponding median of the continuous reinforcement column. However, the two steel jackets increased the medians for failure by 1.872 and 2.017 times, respectively, and exceeded the corresponding median of the continuous reinforcement column by 11.8% and 20.5%, respectively.

  15. Influence of high concentrations of mineral salts on production process and NaCl accumulation by Salicornia europaea plants as a constituent of the LSS phototroph link

    NASA Astrophysics Data System (ADS)

    Tikhomirova, N. A.; Ushakova, S. A.; Kovaleva, N. P.; Gribovskaya, I. V.; Tikhomirov, A. A.

    Use of halophytes (salt-tolerant vegetation), in a particular vegetable Salicornia europaea plants which are capable of utilizing NaCl in rather high concentrations, is one of possible means of NaCl incorporation into mass exchange of bioregenerative life support systems. In preliminary experiments it was shown that S. europaea plants, basically, could grow on urine pretreated with physicochemical processing and urease-enzyme decomposing of urea with the subsequent ammonia distillation. But at the same time inhibition of the growth process of the plants was observed. The purpose of the given work was to find out the influence of excessive quantities of some mineral elements contained in products of physicochemical processing of urine on the production process and NaCl accumulation by S. europaea plants. As the content of mineral salts in the human liquid wastes (urine) changed within certain limits, two variants of experimental solutions were examined. In the first variant, the concentration of mineral salts was equivalent to the minimum salt content in the urine and was: K - 1.5 g/l, P - 0.5 g/l, S - 0.5 g/l, Mg - 0.07 g/l, Ca - 0.2 g/l. In the second experimental variant, the content of mineral salts corresponded to the maximum salt content in urine and was the following: K - 3.0 g/l, P - 0.7 g/l, S - 1.2 g/l, Mg - 0.2 g/l, Ca - 0.97 g/l. As the control, the Tokarev nutrient solution containing nitrogen in the form of a urea, and the Knop nutrient solution with nitrogen in the nitrate form were used. N quantity in all four variants made up 177 mg/l. Air temperature was 24 °C, illumination was continuous. Light intensity was 690 μmol/m 2s of photosynthetically active radiation. NaCl concentration in solutions was 1%. Our researches showed that the dry aboveground biomass of an average plant of the first variant practically did not differ from the control and totaled 11 g. In the second variant, S. europaea productivity decreased and the dry aboveground biomass

  16. Influence of high concentrations of mineral salts on production process and NaCl accumulation by Salicornia europaea plants as a constituent of the LSS phototroph link

    NASA Astrophysics Data System (ADS)

    Tikhomirova, N. A.; Ushakova, S. A.; Kovaleva, N. P.; Gribovskaya, I. V.; Tikhomirov, A. A.

    Use of halophytes, in particular vegetable Salicornia europaea plants which are capable to utilize NaCl in rather high concentrations, is one of possible means of NaCl incorporation into mass exchange of biological life support systems (BLSS). In preliminary experiments it was shown, that S.europaea plants, basically, can grow on urine subjected to physicochemical processing and urease-fermentative decomposing of urea with the subsequent ammonia distillation, but for all that oppression of plants growth process was observed. In this connection, the purpose of the given work was to find out the influence of excessive quantity of some mineral elements contained in products of physicochemical processing of urine on production process and NaCl accumulation by S. europaea plants. As the content of mineral salts in the human's fluid excretions changed within certain limits two variants of modeling solutions were prepared. In the first variant concentration of mineral salts was equivalent to minimum salt content in the human's fluid excretions and compounded: K - 1,5 g/l, P - 0,5 g/l, S - 0,5 g/l, Mg - 0,07 g/l, Ca - 0,2 g/l. In the second variant the content of mineral salts corresponded to maximum salt content in the human's fluid excretions and was the following: K - 3,0 g/l, P - 0,7g/l, S - 1,2 g/l, Mg - 0,2 g/l, Ca - 0,97 g/l. As the control the modified solution under B.I.Tokarev's formulation containing nitrogen in the form of a urea, and Knop's solution with nitrogen in the nitrate form were used. N quantity in all 4 variants made up 177 mg/l. Air temperature was 24°, illumination was continuous. Light intensity was 150 W/m2 PAR. NaCl concentration in solutions compounded 1 %. The researches conducted showed that the dry above-ground biomass of an average plant of the first variant practically did not differ from the control and compounded 11,2 g. In the second variant S.europaea productivity decreased, and the dry above-ground biomass of an average plant

  17. Integrated approach to sustain biogas production in anaerobic digestion of chicken manure under recycled utilization of liquid digestate: Dynamics of ammonium accumulation and mitigation control.

    PubMed

    Wu, Shubiao; Ni, Ping; Li, Jiaxi; Sun, Hao; Wang, Yanfei; Luo, Hongzhen; Dach, Jacek; Dong, Renjie

    2016-04-01

    The dynamics of ammonium accumulation and mitigation control in anaerobic digestion of chicken manure under the recycled utilization of liquid digested slurry were investigated by using an integrated approach in two laboratory-scale semi-continuously stirred tank reactors. In the reactor with direct recycled utilization of the anaerobic digested liquid slurry, total volatilized fatty acids (in CH3COOH) and NH4(+)-N increased from 1600mg/L to 8000mg/L and from 2600mg/L to 5000mg/L, respectively. The daily volumetric biogas production decreased from 1.4±0.1L/(L·d) to 0.8±0.1L/(L·d) with a reduction efficiency of 43±4%. Air stripping was integrated for ammonium mitigation of recycled liquid digested slurry and was shown to effectively reduce the ammonium to 3000mg/L. Correspondingly, the biogas production was recovered back to 1.4±0.1L/(L·d). This indicated the potential of the integration of air stripping for ammonium mitigation in an anaerobic digestion process with liquid digested slurry recirculation. PMID:26812140

  18. Formation and accumulation of radiation-induced defects and radiolysis products in modified lithium orthosilicate pebbles with additions of titanium dioxide

    NASA Astrophysics Data System (ADS)

    Zarins, Arturs; Valtenbergs, Oskars; Kizane, Gunta; Supe, Arnis; Knitter, Regina; Kolb, Matthias H. H.; Leys, Oliver; Baumane, Larisa; Conka, Davis

    2016-03-01

    Lithium orthosilicate (Li4SiO4) pebbles with 2.5 wt.% excess of silicon dioxide (SiO2) are the European Union's designated reference tritium breeding ceramics for the Helium Cooled Pebble Bed (HCPB) Test Blanket Module (TBM). However, the latest irradiation experiments showed that the reference Li4SiO4 pebbles may crack and form fragments under operation conditions as expected in the HCPB TBM. Therefore, it has been suggested to change the chemical composition of the reference Li4SiO4 pebbles and to add titanium dioxide (TiO2), to obtain lithium metatitanate (Li2TiO3) as a second phase. The aim of this research was to investigate the formation and accumulation of radiation-induced defects (RD) and radiolysis products (RP) in the modified Li4SiO4 pebbles with different contents of TiO2 for the first time, in order to estimate and compare radiation stability. The reference and the modified Li4SiO4 pebbles were irradiated with accelerated electrons (E = 5 MeV) up to 5000 MGy absorbed dose at 300-990 K in a dry argon atmosphere. By using electron spin resonance (ESR) spectroscopy it was determined that in the modified Li4SiO4 pebbles, several paramagnetic RD and RP are formed and accumulated, like, E' centres (SiO33-/TiO33-), HC2 centres (SiO43-/TiO3-) etc. On the basis of the obtained results, it is concluded that the modified Li4SiO4 pebbles with TiO2 additions have comparable radiation stability with the reference pebbles.

  19. Metal contaminant accumulation in the hive: Consequences for whole-colony health and brood production in the honey bee (Apis mellifera L.).

    PubMed

    Hladun, Kristen R; Di, Ning; Liu, Tong-Xian; Trumble, John T

    2016-02-01

    Metal pollution has been increasing rapidly over the past century, and at the same time, the human population has continued to rise and produce contaminants that may negatively impact pollinators. Honey bees (Apis mellifera L.) forage over large areas and can collect contaminants from the environment. The primary objective of the present study was to determine whether the metal contaminants cadmium (Cd), copper (Cu), lead (Pb), and selenium (Se) can have a detrimental effect on whole-colony health in the managed pollinator A. mellifera. The authors isolated small nucleus colonies under large cages and fed them an exclusive diet of sugar syrup and pollen patty spiked with Cd, Cu, Pb, and Se or a control (no additional metal). Treatment levels were based on concentrations in honey and pollen from contaminated hives around the world. They measured whole-colony health including wax, honey, and brood production; colony weight; brood survival; and metal accumulation in various life stages. Colonies treated with Cd or Cu contained more dead pupae within capped cells compared with control, and Se-treated colonies had lower total worker weights compared to control. Lead had a minimal effect on colony performance, although many members of the hive accumulated significant quantities of the metal. By examining the honey bee as a social organism through whole-colony assessments of toxicity, the authors found that the distribution of toxicants throughout the colony varied from metal to metal, some caste members were more susceptible to certain metals, and the colony's ability to grow over time may have been reduced in the presence of Se. Apiaries residing near metal-contaminated areas may be at risk and can suffer changes in colony dynamics and survival. PMID:26448590

  20. Accumulation of the planets

    NASA Technical Reports Server (NTRS)

    Wetherill, G. W.

    1987-01-01

    In modeling the accumulation of planetesimals into planets, it is appropriate to distinguish between two stages: an early stage, during which approximately 10 km diameter planetesimals accumulate locally to form bodies approximate 10 to the 25th g in mass; and a later stage in which the approximately 10 to the 25th g planetesimals accumulate into the final planets. In the terrestrial planet region, an initial planetesimal swarm corresponding to the critical mass of dust layer gravitational instabilities is considered. In order to better understand the accumulation history of Mercury-sized bodies, 19 Monte-Carlo simulations of terrestrial planet growth were calculated. A Monte Carlo technique was used to investigate the orbital evolution of asteroidal collision debris produced interior to 2.6 AU. It was found that there are two regions primarily responsible for production of Earth-crossing meteoritic material and Apollo objects. The same techniques were extended to include the origin of Earth-approaching asteroidal bodies. It is found that these same two resonant mechanisms predict a steady-state number of Apollo-Amor about 1/2 that estimated based on astronomical observations.

  1. Starch Products. Learning Activity Pack and Instructor's Guide 5.9. Commercial Foods and Culinary Arts Competency-Based Series. Section 5: Basic Food Preparation.

    ERIC Educational Resources Information Center

    Florida State Univ., Tallahassee. Center for Studies in Vocational Education.

    This document consists of a learning activity packet (LAP) for the student and an instructor's guide for the teacher. The LAP is intended to acquaint occupational home economics students with some basic information about starches and with three starch products found throughout the world: cereals and rice, potatoes, and pasta. Illustrated…

  2. Stress enhances the synthesis of secondary plant products: the impact of stress-related over-reduction on the accumulation of natural products.

    PubMed

    Selmar, Dirk; Kleinwächter, Maik

    2013-06-01

    Spice and medicinal plants grown under water deficiency conditions reveal much higher concentrations of relevant natural products compared with identical plants of the same species cultivated with an ample water supply. For the first time, experimental data related to this well-known phenomenon have been collected and a putative mechanistic concept considering general plant physiological and biochemical aspects is presented. Water shortage induces drought stress-related metabolic responses and, due to stomatal closure, the uptake of CO2 decreases significantly. As a result, the consumption of reduction equivalents (NADPH + H(+)) for CO2 fixation via the Calvin cycle declines considerably, generating a large oxidative stress and an oversupply of reduction equivalents. As a consequence, metabolic processes are shifted towards biosynthetic activities that consume reduction equivalents. Accordingly, the synthesis of reduced compounds, such as isoprenoids, phenols or alkaloids, is enhanced. PMID:23612932

  3. The yeast NOP4 gene product is an essential nucleolar protein required for pre-rRNA processing and accumulation of 60S ribosomal subunits.

    PubMed Central

    Sun, C; Woolford, J L

    1994-01-01

    The Saccharomyces cerevisiae NOP4 gene was isolated by screening a lambda gt11 yeast genomic DNA library with a monoclonal antibody against a yeast nucleolar protein. NOP4 encodes a 78 kDa protein that contains two prototypical RNA recognition motifs (RRMs) flanking an imperfect RRM lacking characteristic RNP1 and RNP2 motifs. In addition, there is a fourth incomplete RRM. NOP4 is a single copy essential gene present on chromosome XVI, between RAD1 and PEP4. To examine the function of Nop4p, we constructed a conditional null allele of NOP4 by placing this gene under the control of the glucose-repressible GAL1 promoter. When cells are shifted from galactose-containing medium to glucose-containing medium, NOP4 transcription is terminated, Nop4 protein is depleted and cell growth is impaired. Nop4 protein depletion results in diminished accumulation of 60S ribosomal subunits, assignable to a defect in ribosome biogenesis arising from a lack of production of mature 25S rRNA from 27S precursor rRNA. Images PMID:8039505

  4. Accumulation of DOC in Low Phosphate Low Chlorophyll (LPLC) area: is it related to higher production under high N:P ratio?

    NASA Astrophysics Data System (ADS)

    Mauriac, R.; Moutin, T.; Baklouti, M.

    2010-09-01

    The biogeochemistry of carbon and nutrients (N, P) in the surface layer of the ocean strongly depends on the interaction between C, N and P at the cell level and at the population level where interaction between primary producers (phytoplankton) and remineralizers (heterotrophic bacteria) impact the overall stock and dynamics of organic carbon. To understand these interactions in the surface layer of the Mediterranean Sea, we implemented, using Eco3M, a multi-element, steady state, mechanistic model. This cell-based model intend to represent the growth of phytoplankton and heterotrophic bacteria under various amount of nutrients. As a results, it displays the expected biogeochemical characteristics of the system and give us insight on the expected interaction between phytoplankton and heterotrophic bacteria both in term of competition for inorganic nutrients and in term of commensalism for organic carbon. In this study, we found a good quantitative agreement between model results and literrature data for stocks and fluxes of the western Mediterranean basin. In addition, for phytoplankton we show how the uncoupling between carbon production and growth could impact the overall DOC dynamic and based on these results, we proposed a new explanantion for the observed DOC accumulation in the surface layer of the Mediterranean Sea.

  5. Effects of tire rubber ash and zinc sulfate on crop productivity and cadmium accumulation in five rice cultivars under field conditions.

    PubMed

    Fahad, Shah; Hussain, Saddam; Khan, Fahad; Wu, Chao; Saud, Shah; Hassan, Shah; Ahmad, Naeem; Gang, Deng; Ullah, Abid; Huang, Jianliang

    2015-08-01

    Cadmium (Cd) is among the most widespread and toxic heavy metals becoming a severe threat to humans. A field study was conducted to examine the role of various zinc (Zn) fertilization treatments and cultivars on crop productivity and Zn and Cd concentrations in brown rice and rice straw. The Zn fertilization treatments included an unfertilized control, foliar applied Zn sulfate (ZnSO4) at panicle initiation stage, foliar applied ZnSO4 at milky stage, soil application of rubber ash, and soil-applied ZnSO4, while five rice cultivars were Swat-1, Shadab, Shua-92, Swat-2, and Sada Hayat. All the Zn fertilization treatments resulted in significantly higher number of panicles, number of spikelets per panicles, spikelet fertility, 1,000-grain weight, grain yield, brown rice and rice straw Zn concentrations, and significantly lower Cd concentrations. Soil application of rubber ash remained the best among all Zn fertilization treatments as it resulted in 73% higher grain yield and reduced Cd concentration by 51% as compared with control. Variations were also apparent among cultivars, and Shua-92 and Swat-2 performed better in terms of all studied attributes as compared with other cultivars. Conclusively, cultivar selection and Zn application are effective strategies to improve rice grain yield as well as quality. Rubber ash appeared a viable source of Zn having the ability to increase yield along with reducing Cd accumulation. PMID:25903182

  6. TRMM and GPM: Radar Observations and Simulations with the Local Analysis and Prediction System (LAPS)

    NASA Astrophysics Data System (ADS)

    Albers, S. C.; Holub, K.; Xie, Y.

    2015-12-01

    The Local Analysis and Prediction System (LAPS), developed at NOAAs Earth System Research Laboratory is used for data assimilation, nowcasting, and model initialization/post-processing.It is a portable system and typically runs with a high resolution and rapid updateBlends a wide variety of in-situ and remotely sensed data sets (e.g. METARs, mesonets, radar, satellite)‏Here we test the assimilation of PMM radar data, using reflectivity obtained from the TRMM satellite, as a preparation for GPM. A case study for July 26 2013 with a small region of convection occurring over Florida. The 3-D LAPS domain is on a 1km grid and is producing analyses and forecasts.TRMM radar data was remapped to mimic the appearance of reflectivity in a ground-based radar over Florida.Three assimilation experiments are being performed using non-radar observations plus: TRMM radar, ground-based radar, and neither source of radar. We are comparing both analyses (initial condition) and forecasts where the WRF modelis initialized with the LAPS analysis. When evaluating the results we consider some big picture aspects in thatthe GPM Core Observatory radar coverage is limited in space and time and potentially less operational model benefit.To address this 4DVAR can help increase impact (particularly in a global model), since it spreads observations in time and space.The spreading in time also helps compensate for latency of the real-time data stream.We can also use GPM (core satellite) radar paired with microwave imager data to calibrate microwave data from other GPM constellation satellites. We thus can leverage more frequent satellite microwave passes compared with radar to assess hydrometeor climatological covariance between various species, fill in ice phase information.These relationships, leveraged from related climate research, help to provide constraints for our planned variational analysis improvements.

  7. A comparative study of the hydroxy acids from the Murchison, GRA 95229 and LAP 02342 meteorites

    NASA Astrophysics Data System (ADS)

    Pizzarello, Sandra; Wang, Yi; Chaban, Galina M.

    2010-11-01

    The hydroxy acid suites extracted from the Murchison (MN), GRA 95229 (GRA) and LAP 02342 (LAP) meteorites have been investigated for their molecular, chiral and isotopic composition. Substantial amounts of the compounds have been detected in all three meteorites, with a total abundance that is lower than that of the amino acids in the same stones. Overall, their molecular distributions mirror closely that of the corresponding amino acids and most evidently so for the LAP meteorite. A surprising L-lactic acid enantiomeric excess was found present in all three stones, which cannot be easily accounted by terrestrial contamination; all other compounds of the three hydroxy acid suites were found racemic. The branched-chain five carbon and the diastereomer six-carbon hydroxy acids were also studied vis-a-vis the corresponding amino acids and calculated ab initio thermodynamic data, with the comparison allowing the suggestion that meteoritic hydroxyacid at these chain lengths formed under thermodynamic control and, possibly, at a later stage than the corresponding amino acids. 13C and D isotopic enrichments were detected for many of the meteoritic hydroxy acids and found to vary between molecular species with trends that also appear to correlate to those of amino acids; the highest δD value (+3450‰) was displayed by GRA 2-OH-2-methylbutyric acid. The data suggest that, while the amino- and hydroxy acids likely relate to common presolar precursor, their final distribution in meteorites was determined to large extent by the overall composition of the environments that saw their formation, with ammonia being the determining factor in their final abundance ratios.

  8. On the determination of diffusion lengths by means of angle-lapped p-n junctions

    NASA Technical Reports Server (NTRS)

    Von Roos, O.

    1979-01-01

    A standard procedure for determining the minority carrier diffusion length by means of SEM consists of scanning an angle-lapped surface of a p-n junction and measuring the resulting short circuit current as a function of beam position. The present paper points out that the usual expression linking the short circuit current induced by the electron beam to the angle between the semiconductor surface and the junction plane is incorrect. The correct expression is discussed and it is noted that, for angles less than 10 deg, the new and the old expression are practically indistinguishable.

  9. An artifical corrosion protocol for lap-splices in aircraft skin

    NASA Technical Reports Server (NTRS)

    Shaw, Bevil J.

    1994-01-01

    This paper reviews the progress to date to formulate an artificial corrosion protocol for the Tinker AFB C/KC-135 Corrosion Fatigue Round Robin Test Program. The project has provided new test methods to faithfully reproduce the corrosion damage within a lap-splice by accelerated means, the rationale for a new laboratory test environment, and a means for corrosion damage quantification. The approach is pragmatic and the resulting artificial corrosion protocol lays the foundation for future research in the assessment of aerospace alloys. The general means for quantification of corrosion damage has been presented in a form which can be directly applied to structural integrity calculations.

  10. Comparison of heating protocols for detection of disbonds in lap joints

    NASA Technical Reports Server (NTRS)

    Winfree, William P.; Crews, B. S.; Howell, P. A.

    1992-01-01

    A thermographic technique is presented which is shown to be effective for disbond detection in lap-joint samples. The study of various heating protocols shows that shorter heating times allow the greatest contrast in smaller disbonds; the optimum heating technique for this case is periodic heating. In order to compare the different heating protocols, contrast is defined as a function of the moments of the histograms for the bonded region and unbonded regions of the reduced thermal images. A comparison of the bonded-unbonded contrast for different heating times establishes the parameters which maximize disbond detection probability.

  11. Bolted Double-Lap Composite Joints Under Mechanical and Thermal Loading

    NASA Technical Reports Server (NTRS)

    Kradinov, V.; Barut, A.; Madenci, E.; Walker, Sandra P. (Technical Monitor)

    2000-01-01

    This study concerns the determination of the contact stresses and contact region around bolt holes and the bolt load distribution in single- and double-lap joints of composite laminates with arbitrarily located bolts under general mechanical loading conditions and uniform temperature change. The unknown contact stress distribution and contact region between the bolt and laminates and the interaction among the bolts require the bolt load distribution, as well as the contact stresses, to be as part of the solution. The present method is based on the complex potential theory and the variational formulation in order to account for bolt stiffness, bolt-hole clearance, and finite geometry of the composite laminates.

  12. Traumatic disruption of the abdominal wall: lap-belt injuries in children.

    PubMed

    Moremen, Jacob R; Nakayama, Don K; Ashley, Dennis W; Astin, Matthew; Nolan, Tracy L

    2013-04-01

    Traumatic abdominal wall hernia (TAWH) from high speed mechanism is a unique finding in adult trauma, and exceedingly rare in pediatrics. The majority of reports are of low-speed "handlebar" hernias associated with direct injury by bicycle handlebars. We report a series of three pediatric patients in motor vehicle collisions (MVC) who experienced TAWH by lap-belt and associated intra-abdominal injuries necessitating immediate operative intervention. Different operative approaches were used in each case to manage the varying types of disruptions. This adds to the pediatric literature the largest series of its kind. PMID:23583160

  13. Endovascular management of lap belt-related abdominal aortic injury in a 9-year-old child.

    PubMed

    Papazoglou, Konstantinos O; Karkos, Christos D; Kalogirou, Thomas E; Giagtzidis, Ioakeim T

    2015-02-01

    Blunt abdominal aortic trauma is a rare occurrence in children with only a few patients having been reported in the literature. Most such cases have been described in the context of lap belt injuries. We report a 9-year-old boy who suffered lap belt trauma to the abdomen during a high-speed road traffic accident resulting to the well-recognized pattern of blunt abdominal injury, that is, the triad of intestinal perforation, fractures of the lumbar spine, and abdominal aortic injury. The latter presented with lower limb ischemia due to dissection of the infrarenal aorta and right common iliac artery. Revascularization was achieved by endovascular means using 2 self-expanding stents in the infrarenal aorta and the right common iliac artery. This case is one of the few reports of lap belt-related acute traumatic abdominal aortic dissection in a young child and highlights the feasibility of endovascular management in the pediatric population. PMID:25463338

  14. Interfacial and Mechanical Behavior of AA5456 Filling Friction-Stir-Welded Lap Joints Using Similar and Dissimilar Pins

    NASA Astrophysics Data System (ADS)

    Behmand, Saleh Alaei; Mirsalehi, Seyyed Ehsan; Omidvar, Hamid; Safarkhanian, Mohammad Ali

    2016-06-01

    In this article, filling friction stir welding (FFSW) of the remaining exit holes of AA5456 alloy friction-stir-welded lap joints was studied. For this purpose, the influences of different rotating speeds, holding times, and pin materials, AA5456 and AA2024, on the metallurgical structure and joint strength were investigated. The observations showed that defect-free lap joints are successfully obtainable by this method using similar and dissimilar consumable pins. The results indicated that the higher rotating speed and holding time adversely affect the weld performance. The best result was achieved for 30 seconds holding time, 500 rpm rotating speed, and AA2024 consumable pin. In this condition, a lap shear strength of 10 pct higher than that of the nonfilled joint, equivalent to about 94 pct of the original defect-free FSW joint, was obtained, whereas the GTAW filled joint showed only approximately 87 pct of the continuous FSW joint strength.

  15. Combining FoxP3 and Helios with GARP/LAP markers can identify expanded Treg subsets in cancer patients

    PubMed Central

    Khaled, Yazan S.; Ammori, Basil J.; Elkord, Eyad

    2016-01-01

    Regulatory T cells (Tregs) comprise numerous heterogeneous subsets with distinct phenotypic and functional features. Identifying Treg markers is critical to investigate the role and clinical impact of various Treg subsets in pathological settings, and also for developing more effective immunotherapies. We have recently shown that non-activated FoxP3−Helios+ and activated FoxP3+/–Helios+ CD4+ T cells express GARP/LAP immunosuppressive markers in healthy donors. In this study we report similar observations in the peripheral blood of patients with pancreatic cancer (PC) and liver metastases from colorectal cancer (LICRC). Comparing levels of different Treg subpopulations in cancer patients and controls, we report that in PC patients, and unlike LICRC patients, there was no increase in Treg levels as defined by FoxP3 and Helios. However, defining Tregs based on GARP/LAP expression showed that FoxP3−LAP+ Tregs in non-activated and activated settings, and FoxP3+Helios+GARP+LAP+ activated Tregs were significantly increased in both groups of patients, compared with controls. This work implies that a combination of Treg-specific markers could be used to more accurately determine expanded Treg subsets and to understand their contribution in cancer settings. Additionally, GARP−/+LAP+ CD4+ T cells made IL-10, and not IFN-γ, and levels of IL-10-secreting CD4+ T cells were elevated in LICRC patients, especially with higher tumor staging. Taken together, our results indicate that investigations of Treg levels in different cancers should consider diverse Treg-related markers such as GARP, LAP, Helios, and others and not only FoxP3 as a sole Treg-specific marker. PMID:26885615

  16. Relaxin Inhibits High Glucose-Induced Matrix Accumulation in Human Mesangial Cells by Interfering with TGF-β1 Production and Mesangial Cells Phenotypic Transition.

    PubMed

    Xie, Xiangcheng; Xia, Wenkai; Fei, Xiao; Xu, Qunhong; Yang, Xiu; Qiu, Donghao; Wang, Ming

    2015-01-01

    Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD). DN is characterized by glomerular extracellular matrix accumulation, mesangial expansion, basement membrane thickening, and renal interstitial fibrosis. To date, mounting evidence has shown that H2 relaxin possesses powerful antifibrosis properties; however, the mechanisms of H2 relaxin on diabetic nephropathy remain unknown. Here, we aimed to explore whether H2 relaxin can reduce production of extracellular matrix (ECM) secreted by human mesangial cells (HMC). HMC were exposed to 5.5 mM glucose (NG) or 30 mM glucose (HG) with or without H2 relaxin. Fibronectin (FN) and collagen type IV levels in the culture supernatants were examined by solid-phase enzyme-linked immunoadsorbent assay (ELISA). Western blot was used to detect the expression of α-smooth muscle actin (α-SMA) protein. Quantitative polymerase chain reaction (qPCR) method was employed to analyze transforming growth factor (TGF)-β1 mRNA expression. Compared with the normal glucose group, the levels of fibronectin and collagen type were markedly increased after being cultured in high glucose medium. Compared with the high glucose group, remarkable decreases of fibronectin, collagen type IV, α-smooth muscle actin, and TGF-β1 mRNA expression were observed in the H2 relaxin-treated group. The mechanism by which H2 relaxin reduced high glucose-induced overproduction of ECM may be associated with inhibition of TGF-β1 mRNA expression and mesangial cells' phenotypic transition. H2 relaxin is a potentially effective modality for the treatment of DN. PMID:26424011

  17. Atomic force and super-resolution microscopy support a role for LapA as a cell-surface biofilm adhesin of Pseudomonas fluorescens

    PubMed Central

    Ivanov, Ivan E.; Boyd, Chelsea D.; Newell, Peter D.; Schwartz, Mary E.; Turnbull, Lynne; Johnson, Michael S.; Whitchurch, Cynthia B.; O’Toole, George A.; Camesano, Terri A.

    2012-01-01

    Pseudomonas fluorescence Pf0-1 requires the large repeat protein LapA for stable surface attachment. This study presents direct evidence that LapA is a cell-surface-localized adhesin. Atomic force microscopy (AFM) revealed a significant twofold reduction in adhesion force for mutants lacking the LapA protein on the cell surface compared to the wild-type strain. Deletion of lapG, a gene encoding a periplasmic cysteine protease that functions to release LapA from the cell surface, resulted in a twofold increase in the force of adhesion. Three-dimensional structured illumination microscopy (3D-SIM) revealed the presence of the LapA protein on the cell surface, consistent with its role as an adhesin. The protein is only visualized in the cytoplasm for a mutant of the ABC transporter responsible for translocating LapA to the cell surface. Together, these data highlight the power of combining the use of AFM and 3D-SIM with genetic studies to demonstrate that LapA, a member of a large group of RTX-like repeat proteins, is a cell-surface adhesin. PMID:23064158

  18. Contributions of kinematics and viscoelastic lap deformation on the suface figure during full aperture polishing of fused silica

    SciTech Connect

    Suratwala, T I; Steele, R A; Feit, M D

    2007-10-09

    A typical optical fabrication process involves a series of basic process steps including: (1) shaping, (2) grinding, (3) polishing, and sometimes (4) sub-aperture tool finishing. With significant innovation and development over the years in both the front end (shaping using CNC machines) and the back end (sup-aperture tool polishing), these processes have become much more deterministic. However, the intermediate stages (full aperture grinding/polishing) in the process, which can be very time consuming, still have much reliance on the optician's insight to get to the desired surface figure. Such processes are not presently very deterministic (i.e. require multiple iterations to get desired figure). The ability to deterministically finish an optical surface using a full aperture grinding/polishing will aid optical glass fabricators to achieve desired figure in a more repeatable, less iterative, and more economical manner. Developing a scientific understanding of the material removal rate is a critical step in accomplishing this. In the present study, the surface figure and material removal rate of a fused silica workpiece is measured as a function of polishing time using Ceria based slurry on a polyurethane pad or pitch lap under a variety of kinematic conditions (motion of the workpiece and lap) and loading configurations. The measured results have been applied to expand the Preston model of material removal (utilizing chemical, mechanical and tribological effects). The results show that under uniform loading, the surface figure is dominated by kinematics which can be predicted by calculating the relative velocity (between the workpiece and the lap) with time and position on the workpiece. However, in the case where the kinematics predict a time-averaged removal function over the workpiece that is uniform, we find experimentally that the surface deviates significantly from uniform removal. We show that this non-uniform removal is caused by the non-uniform stress

  19. Large-Scale Advanced Prop-Fan (LAP) pitch change actuator and control design report

    NASA Technical Reports Server (NTRS)

    Schwartz, R. A.; Carvalho, P.; Cutler, M. J.

    1986-01-01

    In recent years, considerable attention has been directed toward improving aircraft fuel consumption. Studies have shown that the high inherent efficiency previously demonstrated by low speed turboprop propulsion systems may now be extended to today's higher speed aircraft if advanced high-speed propeller blades having thin airfoils and aerodynamic sweep are utilized. Hamilton Standard has designed a 9-foot diameter single-rotation Large-Scale Advanced Prop-Fan (LAP) which will be tested on a static test stand, in a high speed wind tunnel and on a research aircraft. The major objective of this testing is to establish the structural integrity of large-scale Prop-Fans of advanced construction in addition to the evaluation of aerodynamic performance and aeroacoustic design. This report describes the operation, design features and actual hardware of the (LAP) Prop-Fan pitch control system. The pitch control system which controls blade angle and propeller speed consists of two separate assemblies. The first is the control unit which provides the hydraulic supply, speed governing and feather function for the system. The second unit is the hydro-mechanical pitch change actuator which directly changes blade angle (pitch) as scheduled by the control.

  20. Using the LAPS / WRF system to Analyze and Forecast Solar Radiation

    NASA Astrophysics Data System (ADS)

    Albers, S. C.; Xie, Y.; Jiang, H.; Toth, Z.

    2012-12-01

    The Local Analysis and Prediction System (LAPS) is being used to produce rapid update, high resolution analyses and forecasts of solar radiation (Global Horizontal Irradiance or GHI). LAPS is highly portable and can be run onsite, particularly when high-resolution and rapid updating is needed. This allows the user to assimilate their own observational data merged with centrally available observations and to set up the analysis/forecast configuration to their liking. The cloud analysis uses satellite (including IR and 1-km resolution visible imagery, updated every 15-min), METARs, radar, aircraft and model first guess information to produce an hourly 3-D field of cloud fraction, cloud liquid, and cloud ice. The cloud analysis and satellite data together are used to produce a gridded analysis of total solar radiation. This is verified against a dense network of real-time solar radiation measurements that are independent (not used in the analysis). We are focusing mainly on a two nested domains covering the Southern Plains states that encompass networks of pyranometers located in Oklahoma and Texas. The GHI forecast is being run on the outer domain, and is being initialized using the same cloud analysis package that drives the analysis fields mentioned above. The HWT domain initializes WRF every hour with 15-minute output. Real-time verification of the analyses (including images of the analysis), and forecasts can be seen on our website, and updated results will be explored in this presentation.

  1. Using the LAPS / WRF system to Analyze and Forecast Solar Radiation

    NASA Astrophysics Data System (ADS)

    Albers, S. C.; Jankov, I.

    2011-12-01

    The LAPS system is being used to produce rapid update, high resolution analyses and forecasts of solar radiation. The cloud analysis uses satellite, METARs, radar, aircraft and model first guess information to produce an hourly 3-D field of cloud fraction, cloud liquid, and cloud ice. The cloud analysis and satellite data together are used to produce a gridded analysis of total solar radiation. This is verified against solar radiation measurements that are independent (not used in the analysis). Two domains are being run and verified at present. The one with the most stations covers the Oklahoma mesonet with about 100 pyranometers. The total solar radiation forecast is being run on two domains, and is being initialized using the same cloud analysis package that drives the analysis fields mentioned above. The Colorado domain produces hourly forecasts, initialized every 6 hours. It is verified with about 20 Oklahoma mesonet stations. The HWT domain initializes WRF every 2 hours, with 15-minute output. Forecasts are being compared with the Oklahoma mesonet. Real-time verification of the analyses (including images of the analysis), and forecasts can be seen on our website 'laps.noaa.gov', and will be explored in this presentation.

  2. Using LAPS/STMAS as a real time surface analysis tool

    NASA Astrophysics Data System (ADS)

    Moré, Jordi; Farguell, Àngel; Altava, Vicent

    2016-04-01

    A data assimilation system based on the LAPS/STMAS software is tested for a full year (2012) to provide hourly surface analyses at high resolution (3 km) in a complex terrain area centered over Catalonia. In particular, surface observations of more than 150 automatic weather stations (AWS) of the Meteorological Service of Catalonia (SMC) are combined with the operational outputs of WRF-ARW model at 3 km available at SMC. The hourly analyses obtained are verified against independent observations in order to evaluate the system as a real time tool in a small meteorological office. Additionally, an special study is carried out focusing on temperature at 2 m by means of introducing some code modifications in the LAPS/STMAS software. These tests are compared together with a simple multiregression technique exclusively based on observational data (AWS). The comparison shows that the best results are obtained for STMAS when introducing an error weight that depends on the station topography representativeness, instead of just considering a common instrumental error for all the stations. Nevertheless, the multiregression technique still provides more accurate results on temperature and reveals that additional work has to be done in order to improve the system.

  3. Lap shear strength and healing capability of self-healing adhesive containing epoxy/mercaptan microcapsules

    NASA Astrophysics Data System (ADS)

    Ghazali, Habibah; Ye, Lin; Zhang, Ming-Qiu

    2016-03-01

    The aim of this work is to develop a self-healing polymeric adhesive formulation with epoxy/mercaptan microcapsules. Epoxy/mercaptan microcapsules were dispersed into a commercialize two-part epoxy adhesive for developing self-healing epoxy adhesive. The influence of different content of microcapsules on the shear strength and healing capability of epoxy adhesive were investigated using single-lap-joints with average thickness of adhesive layer of about 180 µm. This self-healing adhesive was used in bonding of 5000 series aluminum alloys adherents after mechanical and alkaline cleaning surface treatment. The adhesion strength was measured and presented as function of microcapsules loading. The results indicated that the virgin lap shear strength was increased by about 26% with addition of 3 wt% of self-healing microcapsules. 12% to 28% recovery of the shear strength is achieved after self-healing depending on the microcapsules content. Scanning electron microscopy was used to study fracture surface of the joints. The self-healing adhesives exhibit recovery of both cohesion and adhesion properties with room temperature healing.

  4. The development of laser-plasma interaction program LAP3D on thousands of processors

    NASA Astrophysics Data System (ADS)

    Hu, Xiaoyan; Hao, Liang; Liu, Zhanjun; Zheng, Chunyang; Li, Bin; Guo, Hong

    2015-08-01

    Modeling laser-plasma interaction (LPI) processes in real-size experiments scale is recognized as a challenging task. For explorering the influence of various instabilities in LPI processes, a three-dimensional laser and plasma code (LAP3D) has been developed, which includes filamentation, stimulated Brillouin backscattering (SBS), stimulated Raman backscattering (SRS), non-local heat transport and plasmas flow computation modules. In this program, a second-order upwind scheme is applied to solve the plasma equations which are represented by an Euler fluid model. Operator splitting method is used for solving the equations of the light wave propagation, where the Fast Fourier translation (FFT) is applied to compute the diffraction operator and the coordinate translations is used to solve the acoustic wave equation. The coupled terms of the different physics processes are computed by the second-order interpolations algorithm. In order to simulate the LPI processes in massively parallel computers well, several parallel techniques are used, such as the coupled parallel algorithm of FFT and fluid numerical computation, the load balance algorithm, and the data transfer algorithm. Now the phenomena of filamentation, SBS and SRS have been studied in low-density plasma successfully with LAP3D. Scalability of the program is demonstrated with a parallel efficiency above 50% on about ten thousand of processors.

  5. Microstructure and Fatigue Properties of a Friction Stir Lap Welded Magnesium Alloy

    NASA Astrophysics Data System (ADS)

    Naik, B. S.; Chen, D. L.; Cao, X.; Wanjara, P.

    2013-08-01

    Friction stir welding (FSW), being an enabling solid-state joining technology, can be suitably applied for the assembly of lightweight magnesium (Mg) alloys. In this investigation, friction stir lap welded (FSLWed) joints of AZ31B-H24 Mg alloy were characterized in terms of the welding defects, microstructure, hardness, and fatigue properties at various combinations of tool rotational rates and welding speeds. It was observed that the hardness decreased from the base metal (BM) to the stir zone (SZ) across the heat-affected zone (HAZ) and thermomechanically affected zone (TMAZ). The lowest value of hardness appeared in the SZ. With increasing tool rotational rate or decreasing welding speed, the average hardness in the SZ decreased owing to increasing grain size, and a Hall-Petch-type relationship was established. Fatigue fracture of the lap welds always occurred at the interface between the SZ and TMAZ on the advancing side where a larger hooking defect was present (in comparison with the retreating side). The welding parameters had a significant influence on the hook height and the subsequent fatigue life. A relatively "cold" weld, conducted at a rotational rate of 1000 rpm and welding speed of 20 mm/s, gave rise to almost complete elimination of the hooking defect, thus considerably (over two orders of magnitude) improving the fatigue life. Fatigue crack propagation was basically characterized by the formation of fatigue striations concomitantly with secondary cracks.

  6. Friction Stir Lap Welding of Magnesium Alloy to Steel: A Preliminary Investigation

    NASA Astrophysics Data System (ADS)

    Jana, S.; Hovanski, Y.; Grant, G. J.

    2010-12-01

    An initial study was made to evaluate the feasibility of joining magnesium alloy AZ31 sheet to galvanized steel sheet in a lap configuration using friction stir welding (FSW). Two different automotive sheet steels were used for comparative evaluation of the dissimilar joining potential: a 0.8 mm thick, electrogalvanized (EG) mild steel, and a 1.5 mm thick hot-dipped galvanized (HDG) high-strength, low-alloy (HSLA) steel. These steels were joined to 2.33 mm thick AZ31B magnesium sheet. A single FSW tool design was used for both dissimilar welds, and the process parameters were kept the same. The average peak load for the AZ31-1.5 mm steel weld joint in lap shear mode was found to be 6.3 ± 1.0 kN. For the AZ31-0.8 mm steel weld, joint strength was 5.1 ± 1.5 kN. Microstructural investigation indicates melting of the Zn coating present on the steel sheets, and subsequent alloying with the Mg sheet resulted in the formation of a solidified Zn-Mg alloy layer.

  7. The development of laser-plasma interaction program LAP3D on thousands of processors

    SciTech Connect

    Hu, Xiaoyan Hao, Liang; Liu, Zhanjun; Zheng, Chunyang; Li, Bin Guo, Hong

    2015-08-15

    Modeling laser-plasma interaction (LPI) processes in real-size experiments scale is recognized as a challenging task. For explorering the influence of various instabilities in LPI processes, a three-dimensional laser and plasma code (LAP3D) has been developed, which includes filamentation, stimulated Brillouin backscattering (SBS), stimulated Raman backscattering (SRS), non-local heat transport and plasmas flow computation modules. In this program, a second-order upwind scheme is applied to solve the plasma equations which are represented by an Euler fluid model. Operator splitting method is used for solving the equations of the light wave propagation, where the Fast Fourier translation (FFT) is applied to compute the diffraction operator and the coordinate translations is used to solve the acoustic wave equation. The coupled terms of the different physics processes are computed by the second-order interpolations algorithm. In order to simulate the LPI processes in massively parallel computers well, several parallel techniques are used, such as the coupled parallel algorithm of FFT and fluid numerical computation, the load balance algorithm, and the data transfer algorithm. Now the phenomena of filamentation, SBS and SRS have been studied in low-density plasma successfully with LAP3D. Scalability of the program is demonstrated with a parallel efficiency above 50% on about ten thousand of processors.

  8. (40)Ar/(39)Ar Age of Hornblende-Bearing R Chondrite LAP 04840

    NASA Technical Reports Server (NTRS)

    Righter, K.; Cosca, M.

    2015-01-01

    Chondrites have a complex chronology due to several variables affecting and operating on chondritic parent bodies such as radiogenic heating, pressure and temperature variation with depth, aqueous alteration, and shock or impact heating. Unbrecciated chondrites can record ages from 4.56 to 4.4 Ga that represent cooling in small parent bodies. Some brecciated chondrites exhibit younger ages (much less than 4 to 4.4 Ga) that may reflect the age of brecciation, disturbance, or shock and impact events (much less than 4 Ga). A unique R chondrite was recently found in the LaPaz Icefield of Antarctica - LAP 04840. This chondrite contains approximately 15% hornblende and trace amounts of biotite, making it the first of its kind. Studies have revealed an equigranular texture, mineral equilibria yielding equilibration near 650-700 C and 250-500 bars, hornblende that is dominantly OH-bearing (very little Cl or F), and high D/H ratios. To help gain a better understanding of the origin of this unique sample, we have measured the (40)Ar/(39)Ar age (LAP 04840 split 39).

  9. Microstructure and Properties of Lap Joint Between Aluminum Alloy and Galvanized Steel by CMT

    NASA Astrophysics Data System (ADS)

    Niu, Song; Chen, Su; Dong, Honggang; Zhao, Dongsheng; Zhang, Xiaosheng; Guo, Xin; Wang, Guoqiang

    2016-05-01

    Lap joining of 1-mm-thick Novelist AC 170 PX aluminum alloy to 1.2-mm-thick ST06 Z galvanized steel sheets for automotive applications was conducted by cold metal transfer advanced welding process with ER4043 and ER4047 filler wires. Under the optimized welding parameters with ER4043 filler wire, the tensile shear strength of joint was 189 MPa, reaching 89% of the aluminum alloy base metal. Microstructure and elemental distribution were characterized by optical metalloscope and electron probe microanalysis. The lap joints with ER4043 filler wire had smaller wetting angle and longer bonded line length with better wettability than with ER4047 filler wire during welding with same parameters. The needle-like Al-Fe-Si intermetallic compounds (IMCs) were spalled into the weld and brought negative effect to the tensile strength of joints. With increasing welding current, the needle-like IMCs grew longer and spread further into the weld, which would deteriorate the tensile shear strength.

  10. Joining aluminum to titanium alloy by friction stir lap welding with cutting pin

    SciTech Connect

    Wei, Yanni; Li, Jinglong; Xiong, Jiangtao; Huang, Fu; Zhang, Fusheng; Raza, Syed Hamid

    2012-09-15

    Aluminum 1060 and titanium alloy Ti-6Al-4V plates were lap joined by friction stir welding. A cutting pin of rotary burr made of tungsten carbide was employed. The microstructures of the joining interface were observed by scanning electron microscopy. Joint strength was evaluated by a tensile shear test. During the welding process, the surface layer of the titanium plate was cut off by the pin, and intensively mixed with aluminum situated on the titanium plate. The microstructures analysis showed that a visible swirl-like mixed region existed at the interface. In this region, the Al metal, Ti metal and the mixed layer of them were all presented. The ultimate tensile shear strength of joint reached 100% of 1060Al that underwent thermal cycle provided by the shoulder. - Highlights: Black-Right-Pointing-Pointer FSW with cutting pin was successfully employed to form Al/Ti lap joint. Black-Right-Pointing-Pointer Swirl-like structures formed due to mechanical mixing were found at the interface. Black-Right-Pointing-Pointer High-strength joints fractured at Al suffered thermal cycle were produced.

  11. An evaluation of the blind lap joint for the surface mount attachment of chip components

    NASA Astrophysics Data System (ADS)

    Vianco, P. T.; Dalporto, J. F.

    Blind lap solder joints were used to attach leadless ceramic chip resistors to polyimidequartz circuit boards. Hand soldering and vapor phase reflow techniques were evaluated. The solder was 62Sn-36Pb-2Ag (wt. percent). The integrity of the solder joints was assessed by microstructural examination and room temperature shear tests. These analyses were performed on as-fabricated circuit boards as well as an those samples exposed to thermal cycling (308 cycles; -55 to 125 C; 6 C/min ramps; 120 min hold periods;) or thermal shock (100 cycles, -55 C to 125 C; liquid-to-liquid transfer; 10 min hold periods). In all cases, microscopy revealed no cracks within the solder joints. The shear strengths of the joints were 13.4 lb (59 N), as-fabricated; 10.5 lb (47 N), 308 thermal cycles; and 14.0 lb (62 N), 100 thermal shock cycles. All values were well within acceptability limits for the particular application. Measurements of the intermetallic compound thicknesses at the copper land/solder interface indicated that the additional heating cycle of the hand soldering step decreased the layer thickness as compared to non-hand soldered joints. The successful implementation of the blind lap joint can provide increased device densities on circuit boards by reducing bonding pad extension beyond the ceramic chip foot print.

  12. Multitechnique monitoring of fatigue damage in adhesively bonded composite lap-joints

    NASA Astrophysics Data System (ADS)

    Karpenko, Oleksii; Koricho, Ermias; Khomenko, Anton; Dib, Gerges; Haq, Mahmoodul; Udpa, Lalita

    2015-03-01

    The requirement for reduced structural weight has driven the development of adhesively bonded joints. However, a major issue preventing their full acceptance is the initiation of premature failure in the form of a disbond between adherends, mainly due to fatigue, manufacturing flaws or impact damage. This work presents the integrated approach for in-situ monitoring of degradation of the adhesive bond in the GFRP composite lap-joint using ultrasonic guided waves and dynamic measurements from strategically embedded FBG sensors. Guided waves are actuated with surface mounted piezoelectric elements and mode tuning is used to provide high sensitivity to the degradation of the adhesive layer parameters. Composite lap-joints are subjected to fatigue loading, and data from piezoceramic transducers are collected at regular intervals to evaluate the progression of damage. Results demonstrate that quasi-static loading affects guided wave measurements considerably, but FBG sensors can be used to monitor the applied load levels and residual strains in the adhesive bond. The proposed technique shows promise for determining the post-damage stiffness of adhesively bonded joints.

  13. Monitoring of fatigue damage in composite lap-joints using guided waves and FBG sensors

    NASA Astrophysics Data System (ADS)

    Karpenko, Oleksii; Khomenko, Anton; Koricho, Ermias; Haq, Mahmoodul; Udpa, Lalita

    2016-02-01

    Adhesive bonding is being increasingly employed in many applications as it offers possibility of light-weighting and efficient multi-material joining along with reduction in time and cost of manufacturing. However, failure initiation and progression in critical components like joints, specifically in fatigue loading is not well understood, which necessitates reliable NDE and SHM techniques to ensure structural integrity. In this work, concurrent guided wave (GW) and fiber Bragg grating (FBG) sensor measurements were used to monitor fatigue damage in adhesively bonded composite lap-joints. In the present set-up, one FBG sensor was strategically embedded in the adhesive bond-line of a lap-joint, while two other FBGs were bonded on the surface of the adherends. Full spectral responses of FBG sensors were collected and compared at specific intervals of fatigue loading. In parallel, guided waves were actuated and sensed using PZT wafers mounted on the composite adherends. Experimental results demonstrated that time-of-flight (ToF) of the fundamental modes transmitted through the bond-line and spectral response of FBG sensors were sensitive to fatigue loading and damage. Combination of guided wave and FBG measurements provided the desired redundancy and synergy in the data to evaluate the degradation in bond-line properties. Measurements taken in the presence of continuously applied load replicated the in-situ/service conditions. The approach shows promise in understanding the behavior of bonded joints subjected to complex loading.

  14. Microstructure and Properties of Lap Joint Between Aluminum Alloy and Galvanized Steel by CMT

    NASA Astrophysics Data System (ADS)

    Niu, Song; Chen, Su; Dong, Honggang; Zhao, Dongsheng; Zhang, Xiaosheng; Guo, Xin; Wang, Guoqiang

    2016-04-01

    Lap joining of 1-mm-thick Novelist AC 170 PX aluminum alloy to 1.2-mm-thick ST06 Z galvanized steel sheets for automotive applications was conducted by cold metal transfer advanced welding process with ER4043 and ER4047 filler wires. Under the optimized welding parameters with ER4043 filler wire, the tensile shear strength of joint was 189 MPa, reaching 89% of the aluminum alloy base metal. Microstructure and elemental distribution were characterized by optical metalloscope and electron probe microanalysis. The lap joints with ER4043 filler wire had smaller wetting angle and longer bonded line length with better wettability than with ER4047 filler wire during welding with same parameters. The needle-like Al-Fe-Si intermetallic compounds (IMCs) were spalled into the weld and brought negative effect to the tensile strength of joints. With increasing welding current, the needle-like IMCs grew longer and spread further into the weld, which would deteriorate the tensile shear strength.

  15. Friction Stir Lap Welding of Magnesium Alloy to Steel: A Preliminary Investigation

    SciTech Connect

    Jana, Saumyadeep; Hovanski, Yuri; Grant, Glenn J.

    2010-12-01

    An initial study was made to evaluate the feasibility of joining Magnesium alloy AZ31 sheet to galvanized steel sheet in lap configuration using friction stir welding (FSW). Two different automotive sheet steels were used for comparative evaluation of the dissimilar joining potential; a 0.8mm thick, electro galvanized (EG) mild steel, and a 1.5mm thick hot dipped galvanized (HDG) high-strength, low-alloy steel (HSLA). These steels were joined to 2.33mm thick AZ31B magnesium sheet. A single FSW tool design was used for both dissimilar welds, and process parameters were kept the same. Average peak load for the AZ31-1.5 mm steel weld joint in lap shear mode was found to be 6.3 ± 1.0 kN. For the AZ31-0.8 mm steel weld, joint strength was 5.1 ± 1.5 kN. Microstructural investigation indicates melting of the Zn coating at the interface and subsequent alloying with the Mg sheet resulting in formation of solidified Zn-Mg alloy layer at AZ31/steel interface.

  16. Structure-based hybridization of the bioactive natural products rhizonin A and ternatin leading to a selective fat-accumulation inhibitor against 3T3-L1 adipocytes.

    PubMed

    Shimokawa, Kenichiro; Yamada, Kaoru; Uemura, Daisuke

    2009-02-01

    Based on the structural similarity between the naturally occurring cyclic heptapeptides rhizonin A and ternatin, two novel analogues were designed. The synthetic analogues were assessed with regard to their fat-accumulation inhibitory effect against 3T3-L1 adipocytes, and this led to the discovery of a potent and selective fat-accumulation inhibitor compared to the parent compound rhizonin A. PMID:19097891

  17. Palynological indications for elevated microbial primary productivity during the Early Toarcian Anoxic Event: Implications for organic-carbon accumulation and the interpretation of δ13C-trends

    NASA Astrophysics Data System (ADS)

    Houben, A. J. P.; Goldberg, T.; Janssen, N. M. M.; Nelskamp, S.; Verreussel, R.

    2015-12-01

    The Early Toarcian Oceanic Anoxic Event (T-OAE, ~182 Ma ago) represents an episode of organic-rich deposition that was accompanied by a substantial (up to 7‰) negative carbon-isotope excursion (CIE), suggesting a perturbation in the carbon cycle likely driven by the addition of "light" carbon to the ocean-atmosphere system. Paired δ13Corg-ratios and hydrogen-indices provide evidence for major changes in organic-matter sourcing which quantitatively affect CIE-magnitude. Underpinning the relationship between this carbon-cycle perturbation, ocean anoxia and primary productivity feedbacks thus remains a major challenge. We here present palynological- and organic-matter analysis data from outcrop sections in Yorkshire (UK) and three drill-cores from the Netherlands. In addition, elemental ratios and iron speciation data aid to constrain bottom-water oxygenation and euxinia. Stratigraphic calibrations were achieved with high-resolution δ13Corg-data. The iron-speciation and trace-element data indicate that persistent euxinic bottom-water conditions incept at the base of- and remarkably persist after the T-OAE. By employing extremely careful palynological preparation and UV-fluorescence microscopy, we assessed changes in phytoplankton communities and organic-matter types. At the base of the T-OAE a major increase in abundance of prasinophycean vegetative cysts indicates chemocline shoaling into the photic zone. During the T-OAE, all localities are characterized by organic-matter associations dominated by dense Structureless Organic Matter (SOM) that contain abundant characteristic sphaerical palynomorphs.These results confirm changes in organic-carbon sourcing, which exaggerate the magnitude of the CIE. The palynological and organic-matter data indicate that primary productivity did not collapse and that TOC-accumulations were not merely an effect of inhibited remineralization duirng anoxia. In contrast, we present a scenario in which cyanobacterial anoxygenic

  18. In vivo anti-LAP mAb enhances IL-17/IFN-γ responses and abrogates anti-CD3-induced oral tolerance

    PubMed Central

    da Cunha, Andre P.; Wu, Henry Y.; Rezende, Rafael M.; Vandeventer, Tyler

    2015-01-01

    Regulatory T cells (Tregs) play a critical role in the maintenance of immunological tolerance. The best-characterized Tregs are those expressing the transcription factor Foxp3 and in vivo modulation of Foxp3 Tregs has been employed to study their role in immune homeostasis. Latency-associated peptide (LAP) is a membrane-bound TGF-β complex that has also been shown to play a role in Treg function and oral tolerance. We developed a novel anti-mouse LAP mAb that allowed us to investigate the effect of targeting LAP in vivo on immune function and on anti-CD3-induced oral tolerance. We found that in vivo anti-LAP mAb administration led to a decrease in the number of CD4+LAP+ Tregs in spleen and lymph nodes without affecting CD4+Foxp3+ Tregs. Spleen cells from anti-LAP-injected mice proliferated more in vitro and produced increased amounts of IL-2, IL-17 and IFN-γ. Moreover, injection of anti-LAP antibody abrogated the protective effect of oral anti-CD3 on experimental autoimmune encephalomyelitis (EAE). Finally, in vivo anti-LAP administration prior to myelin oligodendrocyte glycoprotein immunization resulted in severe EAE in the absence of pertussis toxin, which is used for EAE induction. Our findings demonstrate the importance of CD4+LAP+ T cells in the control of immune homeostasis and autoimmunity and provides a new tool for the in vivo investigation of murine LAP+ Tregs on immune function. PMID:25194146

  19. Lake Michigan and Lake Superior air quality: The 1994-2003 LADCO Aircraft Project (LAP)

    NASA Astrophysics Data System (ADS)

    Foley, T. A.; Betterton, E. A.; Jacko, R.; Hillery, J.

    2011-12-01

    The goal of the 1994 to 2003 LADCO Airplane Project (LAP) was to study ozone formation over Lake Michigan so that equitable regional control strategies could be devised. During the ten year LAP campaign, a total of 328 flights were flown on 81 days over Lake Michigan and its southern and western boundaries. LAP also monitored air quality over Lake Superior and other areas in the Midwestern and southern United States. From 2001 to 2003, 117 flights were conducted over Lake Superior, Isle Royale National Park, Painted Rocks National Lakeshore and the Seeney National Wildlife Refuge in Michigan. 63 flights were conducted over St. Louis and 58 flights over the Dolly Sods Wilderness Area in West Virginia. We are looking for collaborators to help us analyze this vast data archive. Our first paper (Atmospheric Environment 45 (2011) 3192-3202) documented the project and presented results of our ozone analysis. Our results support the hypothesis of Dye et al. (1995), who found that the atmosphere over Lake Michigan is stable in the summer due to the air water temperature difference, which creates an efficient reaction chamber for ozone formation. They also hypothesized that the southwest winds characteristic of ozone-conducive conditions transport ozone further north over the lake before it crosses the shoreline onto land. We found that below 200 m above the lake, ozone formation is VOC-limited in the morning and becomes NOx limited in the afternoon. Above 200 m, ozone formation is NOx-limited throughout the day. The onshore NOx and VOC diurnal cycles peak during the early morning rush hour and are clearly linked to traffic patterns. Over the lake, VOC and NOy concentrations peak during the mid-morning rather than the early morning, supporting the hypothesis that the land breeze transports VOC and NOy over the lake. The diurnal NOx pattern over Lake Michigan is less clearly defined than the VOC pattern possibly as a result of emissions from five coal-burning power plants

  20. The Amphibole-Bearing Chondrite Meteorite LAP04840: Metamorphism and `Tectonics' in a Hydrous Asteroid

    NASA Astrophysics Data System (ADS)

    Treiman, A. H.; McCanta, M. C.; Essene, E. J.

    2006-12-01

    LAP04840 is an R-chondrite found in Antarctica, and is unique among meteorites in containing abundant amphibole and biotite. Its chondrules (>500 μm diam) sit in a granoblastic matrix of grains ~20 μm across. Amphibole and biotite grains are anhedral to subhedral, to ~100 μm, and concentrated in chondrules. Commonly, they fit among the olivine and opx grains in regions that would (in anhydrous chondrules) have been occupied by cpx, mesostasis, or glass. Minerals are unzoned, and have constant compositions: olivine Fo62Fa38, Opx En60Wo01, plagioclase An07Ab90, magnesio-hornblende, (Ca1.52Na0.81K0.44) (Mg3.60Fe1.27Mn0.01Ti0.04Cr0.08) (Si6.95Al1.02Fe0.03) O22 (OH1.94?F0.05Cl0.01), sodian phlogopite (low Ti, F, Cl), magnetite (Mt63Chr28Sp05Usp04) and Fe-Ni sulfides. This assemblage is consistent with amphibolite facies equilibrium. Amph-plg thermometry (Holland &Blundy, 1994) gives 675°C, which is consistent with limits of ~600LAP are dry and contain strongly metamorphosed clasts (but no melt rocks). Depending on bulk composition, heating can continue to and beyond the basalt solidus, with core formation and widespread melting and differentiation. An asteroid in the outer belt would accrete abundant ice, which would dilute ^{26}Al and sink much of its heat in melting and vaporization even cores of large asteroids (100+ km radius) would barely reach 675

  1. The poxviral scrapin MV-LAP requires a myxoma viral infection context to efficiently downregulate MHC-I molecules.

    PubMed

    Collin, Nicolas; Guérin, Jean-Luc; Drexler, Ingo; Blanié, Sophie; Gelfi, Jacqueline; Boullier, Séverine; Foucras, Gilles; Sutter, Gerd; Messud-Petit, Frédérique

    2005-12-20

    Downregulation of MHC class I molecules is a strategy developed by some viruses to escape cellular immune responses. Myxoma virus (MV), a poxvirus causing rabbit myxomatosis, encodes MV-LAP that is known to increase MHC-I endocytosis and degradation through a C(4)HC(3) motif critical for an E3 ubiquitin ligase activity. Here, we performed a functional mapping of MV-LAP and showed that not only the C(4)HC(3) motif is necessary for a marked downregulation of MHC-I but also a conserved region in the C-terminal part of the protein. We also showed that the putative transmembrane domains are responsible for a specific subcellular localization of the protein: they retain MV-LAP in the ER in transfected cells and in the endolysosomal compartments in infected cells. We observed that a specific MV infection context is necessary for a fully efficient downregulation of MHC-I. Our data suggest that the functionality of viral LAP factors, inherited by herpes- and poxviruses from mammalian cells, is more complex than anticipated. PMID:16185739

  2. The First Use of the Learning Accomplishment Profile (LAP) in Prekindergarten Head Start 1976-1977. Report Number 77137.

    ERIC Educational Resources Information Center

    Silbermann, David J.

    Prekindergarten Head Start teachers were trained to administer the Learning Accomplishment Profile (LAP), an objective check list of development in seven areas: gross motor, fine motor manipulation and writing, social, self help, cognitive, and language skills. Data were collected from separate groups of 3, 4, and 5-year old children to ascertain…

  3. Research on the design of surface acquisition system of active lap based on FPGA and FX2LP

    NASA Astrophysics Data System (ADS)

    Zhao, Hongshen; Li, Xiaojin; Fan, Bin; Zeng, Zhige

    2014-08-01

    In order to research the dynamic surface shape changes of active lap during the processing, this paper introduces a dynamic surface shape acquisition system of active lap using FPGA and USB communication. This system consists of high-precision micro-displacement sensor array, acquisition board, PC computer composition, and acquisition circuit board includes six sub-boards based on FPGA, a hub-board based on FPGA and USB communication. A sub-board is responsible for a number of independent channel sensors' data acquisition; hub-board is responsible for creating encoder simulation tools to active lap deformation control system with location information, sending synchronization information to latch the sensor data in all of the sub-boards for a time, while addressing the sub-boards to gather the sensor data in each sub-board one by one and transmitting all the sensor data together with location information via the USB chip FX2LP to the host computer. Experimental results show that the system is capable of fixing the location and speed of active lap, meanwhile the control of surface transforming and dynamic surface data acquisition at a certain location in the processing is implemented.

  4. Lamina-associated polypeptide (LAP)2α and nucleoplasmic lamins in adult stem cell regulation and disease.

    PubMed

    Gesson, Kevin; Vidak, Sandra; Foisner, Roland

    2014-05-01

    A-type lamins are components of the lamina network at the nuclear envelope, which mediates nuclear stiffness and anchors chromatin to the nuclear periphery. However, A-type lamins are also found in the nuclear interior. Here we review the roles of the chromatin-associated, nucleoplasmic LEM protein, lamina-associated polypeptide 2α (LAP2α) in the regulation of A-type lamins in the nuclear interior. The lamin A/C-LAP2α complex may be involved in the regulation of the retinoblastoma protein-mediated pathway and other signaling pathways balancing proliferation and differentiation, and in the stabilization of higher-order chromatin organization throughout the nucleus. Loss of LAP2α in mice leads to selective depletion of the nucleoplasmic A-type lamin pool, promotes the proliferative stem cell phenotype of tissue progenitor cells, and delays stem cell differentiation. These findings support the hypothesis that LAP2α and nucleoplasmic lamins are regulators of adult stem cell function and tissue homeostasis. Finally, we discuss potential implications of this concept for defining the molecular disease mechanisms of lamin-linked diseases such as muscular dystrophy and premature aging syndromes. PMID:24374133

  5. Design and analysis on the kinematics of the lap-polisher for optical fiber end face based on tribological theory

    NASA Astrophysics Data System (ADS)

    Lu, Yu-Shan; Wang, Jun; Shu, Qi-Lin; Sun, Jun; Zheng, Xiao-Jiao

    2010-10-01

    In order to obtain the effects of the kinematical state to the profile precision of the fiber optic end surface in the process of lapping and polishing, a kinematical equation of the lap- polisher with the slider-crank movement is developed, and based on these equations and the tribological model of CMP, the dimensionless distribution of the material removal volume (DDMRV) and the trajectory of abrasive grains cutting on the lap-polisher are numerically simulated with the way of stochastic abrasive grains, then the effects of the parameters of the lap-polisher on the uniformity of the DDMRV and the trajectory on the fiber optical end surface are discussed, and the results are that the DDMRV and the trajectory of abrasive grains have rather better value when the crank length E is chosen in a advisable parameter region and the rotational speed n1 of the crank is increased and the rotation speed n0 of the guide plate is decreased.

  6. Amylose-like polysaccharide accumulation and hyphal cell-surface structure in relation to citric acid production by Aspergillus niger in shake culture.

    PubMed

    Kirimura, K; Yusa, S; Rugsaseel, S; Nakagawa, H; Osumi, M; Usami, S

    1999-09-01

    When 120 mg glucose/ml was used as a carbon source, in shake culture Aspergillus niger Yang no. 2 maximally produced only 15.4 mg citric acid/ml but accumulated 3.0 mg extracellular polysaccharide/ml. The polysaccharide secreted by mycelia of Yang no. 2 in shake culture was confirmed to be an amylose-like alpha-1,4-glucan by hydrolysis analysis with acid, amylase and glucoamylase. However, in static cultures, such as semisolid and surface cultures free from physical stresses caused by shaking damage, Yang no. 2 produced more citric acid but did not accumulate the polysaccharide. With cultivation time in shake culture, the amount of extracellular polysaccharide and the viscosity of the culture broth increased. The increase of shaking speed caused a remarkable increase in the accumulation of extracellular polysaccharide, e.g. 11.2 mg extracellular polysaccharide/ml was accumulated in the medium at a shaking speed of 200 rpm. The addition of 2.0 mg carboxymethylcellulose (CMC)/ml as a viscous additive to the medium reduced drastically the amount of extracellular polysaccharide accumulated to 1.5 mg/ml, but increased the citric acid produced to 52.0 mg/ml. However, intracellular polysaccharide accumulation kept up a steady rate of 0.26 microgram/mg dried mycelium through the entire period of cultivation. The addition of 3.0 mg polysaccharide/ml purified from the culture broth to the medium at the start of a culture resulted in a decrease of extracellular polysaccharide accumulation but an increase of citric acid accumulation. From electronmicroscopic observation, cell surfaces of hyphae cultivated with CMC were smooth, while hyphae cultivated without CMC had fibrous and granular polysaccharide on the cell surface. These results suggested that Yang no. 2 secreted the polysaccharide on the cell surface as a viscous substance and/or a shock absorber to protect itself from physical stresses caused by shaking damage in shake culture. PMID:10531655

  7. SRB/SLEEC (Solid Rocket Booster/Shingle Lap Extendible Exit Cone) feasibility study, volume 1

    NASA Technical Reports Server (NTRS)

    Baker, William H., Jr.

    1986-01-01

    A preliminary design and analysis was completed for a SLEEC (Shingle Lap Extendible Exit Cone) which could be incorporated on the Space Transportation System (STS) Solid Rocket Booster (SRB). Studies were completed which predicted weights and performance increases and development plans were prepared for the full-scale bench and static test of SLEEC. In conjunction with the design studies, a series of supporting analyses were performed to assure the validity and feasibility of performance, fabrication, cost, and reliability for the selected design. The feasibility and required amounts of bench, static firing, and flight tests considered necessary for the successful incorporation of SLEEC on the Shuttle SRBs were determined. Preliminary plans were completed which define both a follow on study effort and a development program.

  8. A scan-angle correction for thermal infrared multispectral data using side lapping images

    USGS Publications Warehouse

    Watson, K.

    1996-01-01

    Thermal infrared multispectral scanner (TIMS) images, acquired with side lapping flight lines, provide dual angle observations of the same area on the ground and can thus be used to estimate variations in the atmospheric transmission with scan angle. The method was tested using TIMS aircraft data for six flight lines with about 30% sidelap for an area within Joshua Tree National Park, California. Generally the results correspond to predictions for the transmission scan-angle coefficient based on a standard atmospheric model although some differences were observed at the longer wavelength channels. A change was detected for the last pair of lines that may indicate either spatial or temporal atmospheric variation. The results demonstrate that the method provides information for correcting regional survey data (requiring multiple adjacent flight lines) that can be important in detecting subtle changes in lithology.

  9. A two-dimensional stress analysis of single lap joints subjected to external bending moments

    SciTech Connect

    Sawa, Toshiyuki; Nakano, Katsuyuki; Toratani, Hiroshi

    1995-11-01

    The stress distribution of single lap adhesive joints subjected to external bending moments are analyzed as a three-body contact problem by using a two-dimensional theory of elasticity. In the analysis, two similar adherends and an adhesive are replaced by finite strips, respectively. In the numerical calculations, the effects of the ratio of Young;s modulus of adherends to that of adhesive and the adhesive thickness on the stress distribution at the interface are examined. As the results, it is seen that the stress singularity causes at the edges of the interfaces and the peel stress at the edges of the interface increases with a decrease of Young`s modulus of the adherends. In addition, photoelastic experiments are carried out. A fairly good agreement is seen between the analytical and the experimental results.

  10. Shear Strength of Single Lap Joint Aluminium-Thermoplastic Natural Rubber (Al-TPNR) Laminated Composite

    NASA Astrophysics Data System (ADS)

    Muzakkar, M. Z.; Ahmad, S.; Yarmo, M. A.; Jalar, A.; Bijarimi, M.

    2013-04-01

    In this work, we studied the effect of surface treatment on the aluminium surface and a coupling agent to improve adhesion between aluminium with organic polymer. Thermoplastic natural rubber (TPNR) matrix was prepared by melt blending of natural rubber (NR), liquid natural rubber (LNR) compatibilizer, linear low density polyethylene (LLDPE) and polyethylene grafted maleic anhydride (PE-g-MAH). The PEgMAH concentration used was varied from 0% - 25%. In addition, the aluminium surface was pre-treated with 3-glycidoxy propyl trimethoxy silane (3-GPS) to enhance the mechanical properties of laminated composite. It was found that the shear strength of single lap joint Al-TPNR laminated composite showing an increasing trend as a function of PE-g-MAH contents for the 3-GPS surface treated aluminium. Moreover, the scanning electron microscope (SEM) revealed that the strength improvement was associated with the chemical state of the compound involved.

  11. Adhesive-bonded double-lap joints. [analytical solutions for static load carrying capacity

    NASA Technical Reports Server (NTRS)

    Hart-Smith, L. J.

    1973-01-01

    Explicit analytical solutions are derived for the static load carrying capacity of double-lap adhesive-bonded joints. The analyses extend the elastic solution Volkersen and cover adhesive plasticity, adherend stiffness imbalance and thermal mismatch between the adherends. Both elastic-plastic and bi-elastic adhesive representations lead to the explicit result that the influence of the adhesive on the maximum potential bond strength is defined uniquely by the strain energy in shear per unit area of bond. Failures induced by peel stresses at the ends of the joint are examined. This failure mode is particularly important for composite adherends. The explicit solutions are sufficiently simple to be used for design purposes

  12. FRACTURE MECHANICS APPROACH TO ESTIMATE FATIGUE LIVES OF WELDED LAP-SHEAR SPECIMENS

    SciTech Connect

    Lam, P.; Michigan, J.

    2014-04-25

    A full range of stress intensity factor solutions for a kinked crack is developed as a function of weld width and the sheet thickness. When used with the associated main crack solutions (global stress intensity factors) in terms of the applied load and specimen geometry, the fatigue lives can be estimated for the laser-welded lap-shear specimens. The estimations are in good agreement with the experimental data. A classical solution for an infinitesimal kink is also employed in the approach. However, the life predictions tend to overestimate the actual fatigue lives. The traditional life estimations with the structural stress along with the experimental stress-fatigue life data (S-N curve) are also provided. In this case, the estimations only agree with the experimental data under higher load conditions.

  13. The lap-counting and zeta functions of the tent map

    NASA Astrophysics Data System (ADS)

    Flatto, Leopold; Lagarias, Jeffrey C.

    2000-07-01

    The tent map tβ:[0,1]→[0,1] with parameter 1 < β≤2 is defined by t_{\\beta }(x) = \\cases{\\beta x & $0 \\leq x \\leq \\case{1}{2}$\\\\ \\beta (1- x) & $\\case{1}{2} \\leq x \\leq 1$. } This paper derives formulae for its dynamical zeta and <span class=lap-counting functions which exhibit the renormalization structure of such maps. It relates these functions to the centrally symmetric linear mod 1 transformation f_ {\\beta }(x) = \\beta x + 1- \\case{1}{2} \\beta\\quad (\\mathop{\\rm mod} 1). The singularities of these functions on the circle |z| = 1/β are determined explicitly.

  14. Stress analysis of the cracked lap shear specimens: An ASTM round robin

    NASA Technical Reports Server (NTRS)

    Johnson, W. S.

    1986-01-01

    This ASTM Round Robin was conducted to evaluate the state of the art in stress analysis of adhesively bonded joint specimens. Specifically, the participants were asked to calculate the strain-energy-release rate for two different geometry cracked lap shear (CLS) specimens at four different debond lengths. The various analytical techniques consisted of 2- and 3-dimensional finite element analysis, beam theory, plate theory, and a combination of beam theory and finite element analysis. The results were examined in terms of the total strain-energy-release rate and the mode I to mode II ratio as a function of debond length for each specimen geometry. These results basically clustered into two groups: geometric linear or geometric nonlinear analysis. The geometric nonlinear analysis is required to properly analyze the CLS specimens. The 3-D finite element analysis gave indications of edge closure plus some mode III loading. Each participant described his analytical technique and results. Nine laboratories participated.

  15. Abrasion and deformed layer formation of manganese-zinc ferrite in sliding contact with lapping tapes

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Buckley, D. H.; Tanaka, K.

    1986-01-01

    Wear experiments were conducted using replication electron microscopy and reflection electron diffraction to study abrasion and the deformed layers produced in single-crystal Mn-Zn ferrite simulated heads during contact with lapping tapes. The crystaline state of the head is changed drastically during the abrasion process. Crystalline states ranging from nearly amorphous to highly textured polycrystalline can be produced on the wear surface of a single-crystal Mn-Zn ferrite head. The total thickness of the deformed layer was approximately 0.8 microns. This thickness increased as the load and abrasive grit size increased. The anisotropic wear of the ferrite was found to be inversely proportional to the hardness of the wear surface. The wear was lower in the order 211 111 10 0110. The wear of the ferrite increased markedly with an increase in sliding velocity and abrasive grit size.

  16. Quantitative strain and slope evaluation on a double lap joint tensile test using ESPSI

    NASA Astrophysics Data System (ADS)

    Molimard, J.; Bounda, D.; Vautrin, A.

    2006-08-01

    The present study is based on the use of electronical speckle pattern shearing interferometry (ESPSI) on a double lap joint, the joined parts being two steel blocks and two composite plates. ESPSI is used to investigate de strain maps close to the end of the bonding in the center part of the specimen. The ESPSI set-up allows to get the full field strain and slope maps of a given surface. Its architecture is based on optical fibres which gives a portable assembly that can be used in a civil/mechanical engineering laboratory. This presentation emphases the advantages of such a method and its performances. Last some results are given and compared to an analytical approach.

  17. Mutation in TOR1AIP1 encoding LAP1B in a form of muscular dystrophy: a novel gene related to nuclear envelopathies.

    PubMed

    Kayman-Kurekci, Gulsum; Talim, Beril; Korkusuz, Petek; Sayar, Nilufer; Sarioglu, Turkan; Oncel, Ibrahim; Sharafi, Parisa; Gundesli, Hulya; Balci-Hayta, Burcu; Purali, Nuhan; Serdaroglu-Oflazer, Piraye; Topaloglu, Haluk; Dincer, Pervin

    2014-07-01

    We performed genome-wide homozygosity mapping and mapped a novel myopathic phenotype to chromosomal region 1q25 in a consanguineous family with three affected individuals manifesting proximal and distal weakness and atrophy, rigid spine and contractures of the proximal and distal interphalangeal hand joints. Additionally, cardiomyopathy and respiratory involvement were noted. DNA sequencing of torsinA-interacting protein 1 (TOR1AIP1) gene encoding lamina-associated polypeptide 1B (LAP1B), showed a homozygous c.186delG mutation that causes a frameshift resulting in a premature stop codon (p.E62fsTer25). We observed that expression of LAP1B was absent in the patient skeletal muscle fibres. Ultrastructural examination showed intact sarcomeric organization but alterations of the nuclear envelope including nuclear fragmentation, chromatin bleb formation and naked chromatin. LAP1B is a type-2 integral membrane protein localized in the inner nuclear membrane that binds to both A- and B-type lamins, and is involved in the regulation of torsinA ATPase. Interestingly, luminal domain-like LAP1 (LULL1)-an endoplasmic reticulum-localized partner of torsinA-was overexpressed in the patient's muscle in the absence of LAP1B. Therefore, the findings suggest that LAP1 and LULL1 might have a compensatory effect on each other. This study expands the spectrum of genes associated with nuclear envelopathies and highlights the critical function for LAP1B in striated muscle. PMID:24856141

  18. Thin plate gap bridging study for Nd:YAG pulsed laser lap welds.

    SciTech Connect

    Roach, Robert Allen; Fuerschbach, Phillip William; Bernal, John E.; Norris, Jerome T.

    2006-01-01

    In an on going study of gap bridging for thin plate Nd:YAG laser lap welds, empirical data, high speed imaging, and computer modeling were utilized to better understand surface physics attributed to the formation and solidification of a weld pool. Experimental data indicates better gap bridging can be achieved through optimized laser parameters such as pulse length, duration, and energy. Long pulse durations at low energies generating low peak powers were found to create the highest percent of gap bridging ability. At constant peak power, gap-bridging ability was further improved by using a smaller spot diameter resulting in higher irradiances. Hence, welding in focus is preferable for bridging gaps. Gas shielding was also found to greatly impact gap-bridging ability. Gapped lap welds that could not be bridged with UHP Argon gas shielding, were easily bridged when left unshielded and exposed to only air. Incident weld angle and joint offset were also investigated for their ability to improve gap bridging. Optical filters and brightlight surface illumination enabled high-speed imaging to capture the fluid dynamics of a forming and solidifying weld pool. The effects of various laser parameters and the weld pool's interaction with the laser beam could also be observed utilizing the high-speed imaging. The work described is used to develop and validate a computer model with improved weld pool physics. Finite element models have been used to derive insight into the physics of gap bridging. The dynamics of the fluid motion within the weld pool in conjunction with the free surface physics have been the primary focus of the modeling efforts. Surface tension has been found to be a more significant factor in determining final weld pool shape than expected.

  19. Rapamycin reverses age-related increases in mitochondrial ROS production at complex I, oxidative stress, accumulation of mtDNA fragments inside nuclear DNA, and lipofuscin level, and increases autophagy, in the liver of middle-aged mice.

    PubMed

    Martínez-Cisuelo, V; Gómez, J; García-Junceda, I; Naudí, A; Cabré, R; Mota-Martorell, N; López-Torres, M; González-Sánchez, M; Pamplona, R; Barja, G

    2016-10-01

    Rapamycin consistently increases longevity in mice although the mechanism of action of this drug is unknown. In the present investigation we studied the effect of rapamycin on mitochondrial oxidative stress at the same dose that is known to increase longevity in mice (14mgofrapamycin/kg of diet). Middle aged mice (16months old) showed significant age-related increases in mitochondrial ROS production at complex I, accumulation of mtDNA fragments inside nuclear DNA, mitochondrial protein lipoxidation, and lipofuscin accumulation compared to young animals (4months old) in the liver. After 7weeks of dietary treatment all those increases were totally or partially (lipofuscin) abolished by rapamycin, middle aged rapamycin-treated animals showing similar levels in those parameters to young animals. The decrease in mitochondrial ROS production was due to qualitative instead of quantitative changes in complex I. The decrease in mitochondrial protein lipoxidation was not due to decreases in the amount of highly oxidizable unsaturated fatty acids. Rapamycin also decreased the amount of RAPTOR (of mTOR complex) and increased the amounts of the PGC1-α and ATG13 proteins. The results are consistent with the possibility that rapamycin increases longevity in mice at least in part by lowering mitochondrial ROS production and increasing autophagy, decreasing the derived final forms of damage accumulated with age which are responsible for increased longevity. The decrease in lipofuscin accumulation induced by rapamycin adds to previous information suggesting that the increase in longevity induced by this drug can be due to a decrease in the rate of aging. PMID:27498120

  20. A trial of production of the plant-derived high-value protein in a plant factory: photosynthetic photon fluxes affect the accumulation of recombinant miraculin in transgenic tomato fruits.

    PubMed

    Kato, Kazuhisa; Maruyama, Shinichiro; Hirai, Tadayoshi; Hiwasa-Tanase, Kyoko; Mizoguchi, Tsuyoshi; Goto, Eiji; Ezura, Hiroshi

    2011-08-01

    One of the ultimate goals of plant science is to test a hypothesis obtained by basic science and to apply it to agriculture and industry. A plant factory is one of the ideal systems for this trial. Environmental factors affect both plant yield and the accumulation of recombinant proteins for industrial applications within transgenic plants. However, there have been few reports studying plant productivity for recombinant protein in closed cultivation systems called plant factories. To investigate the effects of photosynthetic photon flux (PPF) on tomato fruit yield and the accumulation of recombinant miraculin, a taste-modifying glycoprotein, in transgenic tomato fruits, plants were cultivated at various PPFs from 100 to 400 (µmol m(-2) s(-)1) in a plant factory. Miraculin production per unit of energy used was highest at PPF100, although miraculin production per unit area was highest at PPF300. The commercial productivity of recombinant miraculin in transgenic tomato fruits largely depended on light conditions in the plant factory. Our trial will be useful to consider the trade-offs between the profits from production of high-value materials in plants and the costs of electricity. PMID:21791976

  1. Effect of Viscosity on Fuel Leakage Between Lapped Plungers and Sleeves and on the Discharge from a Pump-Injection System

    NASA Technical Reports Server (NTRS)

    Rothrock, A M; Marsh, E T

    1935-01-01

    Test data and analysis show that the rate of fuel leakage between a lapped plunger and sleeve varies directly with the density of the fuel, the diameter of the plunger, the pressure producing the leakage, and the cube of the mean clearance between the plunger and sleeve. The rate varies inversely as the length of the lapped fit and the viscosity of the fuel. With a mean clearance between the plunger and sleeve of 0.0001 inch the leakage amounts to approximately 0.2 percent of the fuel injected with gasoline and as low as 0.01 percent with diesel fuel oils. With this mean clearance an effective seal is obtained when the length of the lap is three times the diameter of the lap. The deformation of the sleeve and plunger under pressure is sufficient to change the rate of leakage appreciably from that which would be obtained if the clearance was constant under pressure.

  2. Growth of thin, c-axis oriented Sr-doped LaP3O9 electrolyte membranes in condensed phosphoric acid solutions

    NASA Astrophysics Data System (ADS)

    Hatada, Naoyuki; Takahashi, Kota; Adachi, Yoshinobu; Uda, Tetsuya

    2016-08-01

    Proton-conducting Sr-doped LaP3O9 has potential application as electrolytes in intermediate temperature fuel cells, but reduction of the electrical resistance of the electrolyte membranes is necessary for practical applications. In this study, we focused on reducing the resistance by reducing the electrolyte thickness, while maintaining a preferable microstructure for proton conduction (c-axis orientation and absence of the small-crystal layer). Thin, c-axis oriented Sr-doped LaP3O9 membranes were successfully obtained in condensed phosphoric acid solutions by a novel "two-step precipitation method". In this method, Sr-doped LaP3O9 powder was artificially deposited on the surface of the carbon paper supports as seeds, and then columnar crystals were grown "downward" in the solutions. We expect that this method will be utilized to produce LaP3O9 electrolyte membranes with lower electrical resistance.

  3. Programmed death 1 regulates memory phenotype CD4 T cell accumulation, inhibits expansion of the effector memory phenotype subset and modulates production of effector cytokines.

    PubMed

    Charlton, Joanna J; Tsoukatou, Debbie; Mamalaki, Clio; Chatzidakis, Ioannis

    2015-01-01

    Memory phenotype CD4 T cells are found in normal mice and arise through response to environmental antigens or homeostatic mechanisms. The factors that regulate the homeostasis of memory phenotype CD4 cells are not clear. In the present study we demonstrate that there is a marked accumulation of memory phenotype CD4 cells, specifically of the effector memory (T(EM)) phenotype, in lymphoid organs and tissues of mice deficient for the negative co-stimulatory receptor programmed death 1 (PD-1). This can be correlated with decreased apoptosis but not with enhanced homeostatic turnover potential of these cells. PD-1 ablation increased the frequency of memory phenotype CD4 IFN-γ producers but decreased the respective frequency of IL-17A-producing cells. In particular, IFN-γ producers were more abundant but IL-17A producing cells were more scarce among PD-1 KO T(EM)-phenotype cells relative to WT. Transfer of peripheral naïve CD4 T cells suggested that accumulated PD-1 KO T(EM)-phenotype cells are of peripheral and not of thymic origin. This accumulation effect was mediated by CD4 cell-intrinsic mechanisms as shown by mixed bone marrow chimera experiments. Naïve PD-1 KO CD4 T cells gave rise to higher numbers of TEM-phenotype lymphopenia-induced proliferation memory cells. In conclusion, we provide evidence that PD-1 has an important role in determining the composition and functional aspects of memory phenotype CD4 T cell pool. PMID:25803808

  4. Behavior and design of reinforced concrete column-type lapped splices subjected to high-intensity cyclic loading

    NASA Astrophysics Data System (ADS)

    Sivakumar, B.; White, R. N.; Gergely, P.

    1982-10-01

    The behavior and design of lapped splices in reinforced concrete column type specimens under high intensity flexural cyclic loads was studied. Special attention is focused on the transverse steel requirements of specimens with more than two splices in a layer; the use of offsets in spliced bars; the effect of concrete strength on splice strength and behavior; and the strength of epoxy-repaired splices. Procedures are provided for the design of reinforced lapped splices to sustain at least twenty reversing load cycles beyond yield and a maximum rebar strain at the splice of at least 2.5 times the yield strain. The key aspect of the design is the provision of closely spaced uniformly distributed stirrup ties in the splice region. Equations are developed for the spacing of stirrups and the minimum splice length requirement.

  5. Analysis of the Vibration Damping of Bonded Beams with a Single-Lap-Joint and Partial Dampers

    NASA Astrophysics Data System (ADS)

    Choi, Nak-Sam; Park, Jeong-Il

    A theoretical analysis model for the lateral vibration of beams with a bonded single-lap-joint and partial layered dampers has been proposed in this paper. Both shear and normal forces acting along the interface between the elastic and viscoelastic layers were considered in the vibration analysis. The analytical results were comparable to those obtained by the modal strain energy method and the harmonic response analysis, which were based on a finite element model. The effects of the location and thickness of the partial dampers on the system loss factor ηs were studied. The characteristic variations of ηs, with changes of the modulus and loss factor of the viscoelastic layer in the lap joint part and partial dampers were also studied. Consequently, the geometrical and material conditions at maximizing ηs were suggested.

  6. Gastric lap-band infection due to Mycobacterium abscessus presenting as new-onset ascites in a cirrhotic patient.

    PubMed

    Kahn, Allon; Agrwal, Neera; Carey, Elizabeth J; Madura, James A; Hewitt, Winston R; Lambert, Karen L; Grys, Thomas E; Vikram, Holenarasipur R

    2016-08-01

    Nontuberculous mycobacteria are ubiquitous environmental organisms that are infrequently implicated as pathogens. Peritoneal infection with nontuberculous mycobacteria is rare and published reports are most commonly associated with peritoneal dialysis. This study describes a case of a 41-year-old woman with cirrhosis who had Mycobacterium abscessus peritonitis and an abdominal abscess resulting from infection of a remotely placed gastric band (Lap-Band; Apollo Endosurgery, Inc). PMID:27222118

  7. Design of a micro lapping system based on double-feedback control algorithm for manufacturing optical micro components

    NASA Astrophysics Data System (ADS)

    Che, Lin; Li, Guo; Wang, Bo; Ding, Fei; Mao, Xing; Dong, Wenxia

    2014-08-01

    This paper presents a micro lapping machine tool, which is dedicated for manufacturing the high-precision optical micro components with 3-D micro structures. And it can remove the damaged surface layer efficiently.In order to control machining process precisely, a double-feedback control system strategy is proposed and implemented. Lapping force signal from the clamp feeds back at the same time with position signal from grating scale close-looped devices. With the function of position keeping , a dual-stage drive micro-displacement servo system is used to provide the desired performance in the vertical feeding direction. Random lapping trace is formed with combinations of two mutually-perpendicular horizontal liner motion. A clamp with the function of micro force detection is designed to monitor the machining process and control the lapping force. Based on force feedback, a tool auto-checking strategy is conducted to realize the tool checking in limited tiny space. Corresponding experiments are undertaken to test the properties of the machine tool.And, the optical micro components are manufactured successfully. The optical components are measured and analysised before and after processing. The experimental results show that the position-keeping accuracy of the dual-stage feed drive system can reach to ±0.02μm, the resolution of motion control can reach to 20nm.The Sa value of the processed component can reach 0.0882um. Surface quality can be improved obviously and the damaged surface layer is removed efficiently.The theoretical and experimental results show the validity of the machine tool and the control algorithm.

  8. Proliferation of progeria cells is enhanced by lamina-associated polypeptide 2α (LAP2α) through expression of extracellular matrix proteins

    PubMed Central

    Vidak, Sandra; Kubben, Nard; Dechat, Thomas; Foisner, Roland

    2015-01-01

    Lamina-associated polypeptide 2α (LAP2α) localizes throughout the nucleoplasm and interacts with the fraction of lamins A/C that is not associated with the peripheral nuclear lamina. The LAP2α–lamin A/C complex negatively affects cell proliferation. Lamins A/C are encoded by LMNA, a single heterozygous mutation of which causes Hutchinson-Gilford progeria syndrome (HGPS). This mutation generates the lamin A variant progerin, which we show here leads to loss of LAP2α and nucleoplasmic lamins A/C, impaired proliferation, and down-regulation of extracellular matrix components. Surprisingly, contrary to wild-type cells, ectopic expression of LAP2α in cells expressing progerin restores proliferation and extracellular matrix expression but not the levels of nucleoplasmic lamins A/C. We conclude that, in addition to its cell cycle-inhibiting function with lamins A/C, LAP2α can also regulate extracellular matrix components independently of lamins A/C, which may help explain the proliferation-promoting function of LAP2α in cells expressing progerin. PMID:26443848

  9. Proliferation of progeria cells is enhanced by lamina-associated polypeptide 2α (LAP2α) through expression of extracellular matrix proteins.

    PubMed

    Vidak, Sandra; Kubben, Nard; Dechat, Thomas; Foisner, Roland

    2015-10-01

    Lamina-associated polypeptide 2α (LAP2α) localizes throughout the nucleoplasm and interacts with the fraction of lamins A/C that is not associated with the peripheral nuclear lamina. The LAP2α-lamin A/C complex negatively affects cell proliferation. Lamins A/C are encoded by LMNA, a single heterozygous mutation of which causes Hutchinson-Gilford progeria syndrome (HGPS). This mutation generates the lamin A variant progerin, which we show here leads to loss of LAP2α and nucleoplasmic lamins A/C, impaired proliferation, and down-regulation of extracellular matrix components. Surprisingly, contrary to wild-type cells, ectopic expression of LAP2α in cells expressing progerin restores proliferation and extracellular matrix expression but not the levels of nucleoplasmic lamins A/C. We conclude that, in addition to its cell cycle-inhibiting function with lamins A/C, LAP2α can also regulate extracellular matrix components independently of lamins A/C, which may help explain the proliferation-promoting function of LAP2α in cells expressing progerin. PMID:26443848

  10. Residual Stresses and Tensile Properties of Friction Stir Welded AZ31B-H24 Magnesium Alloy in Lap Configuration

    NASA Astrophysics Data System (ADS)

    Naik, Bhukya Srinivasa; Cao, Xinjin; Wanjara, Priti; Friedman, Jacob; Chen, Daolun

    2015-08-01

    AZ31B-H24 Mg alloy sheets with a thickness of 2 mm were friction stir welded in lap configuration using two tool rotational rates of 1000 and 1500 rpm and two welding speeds of 10 and 20 mm/s. The residual stresses in the longitudinal and transverse directions of the weldments were determined using X-ray diffraction. The shear tensile behavior of the lap joints was evaluated at low [233 K (-40 °C)], room [298 K (25 °C)], and elevated [453 K (180 °C)] temperatures. The failure load was highest for the lower heat input condition that was obtained at a tool rotational rate of 1000 rpm and a welding speed of 20 mm/s for all the test temperatures, due to the smaller hooking height, larger effective sheet thickness, and lower tensile residual stresses, as compared to the other two welding conditions that were conducted at a higher tool rotational rate or lower welding speed. The lap joints usually fractured on the advancing side of the top sheet near the interface between the thermo-mechanically affected zone and the stir zone. Elevated temperature testing of the weld assembled at a tool rotational rate of 1000 rpm and a welding speed of 20 mm/s led to the failure along the sheet interface in shear fracture mode due to the high integrity of the joint that exhibited large plastic deformation and higher total energy absorption.

  11. Highly Variable Holocene Antarctic Climate: A High-Resolution Marine Geochemical Record of Surface and Export Production, Terrigenous Provenance, and Terrigenous Accumulation from the Palmer Deep, West Antarctic Peninsula.

    NASA Astrophysics Data System (ADS)

    Kryc, K. A.; Murray, R. W.; Dunbar, R. B.

    2001-12-01

    The Antarctic Peninsula is an ideal region to investigate climate change at decadal to millennial timescales due to its location in one of the earth's most dynamic climate systems. We have targeted the geochemical sedimentary record of ODP Site 1098 in the Palmer Deep to investigate changes in Holocene glacial evolution and oscillations in the Circumpolar Deep Water as traced by terrigenous provenance, terrigenous accumulation, nutrient utilization, and surface and export production. More than 50 meters of laminated diatomaceous muds, oozes, and muddy diamictons were recovered from the Palmer Deep, comprising the first, high-resolution, continuous Holocene sediment record from the Antarctic continental margin. We report on a synthesis of trace and major element, stable isotope, and C/N geochemistry on samples collected at a temporal resolution ranging from ~8 to ~50 years. We analyzed Si, Al, Ti, P, Ba, biogenic opal, organic C and N, and organic 13C/12C and 15N/14N isotopic ratios every 2.5 to 10 cm downcore. A series of sequential extractions were completed on a subset of samples to better constrain the elemental distribution within the different components of the sediment. Our chronology is based on 36 AMS radiocarbon dates. Biogenic opal, Corg, and P accumulation rates all increase ~2,000 years B.P., reaching a maximum ~5,500 to 7,000 years B.P. Opal concentrations are less variable, yet indicate that biosiliceous production increased during the mid-Holocene. 13C/12C in bulk organic matter are high (with values similar to ice-edge bloom products) ~4500 to 7000 years B.P., signifying stronger diatom bloom events during the mid-Holocene. Prior to ~3000 years B.P., delta15N was lower for ~2,000 years, resulting from less complete utilization of photic zone nitrate. The Al/Ti ratio indicates a change in terrigenous composition ~3500 years B.P. indicating a change in source, weathering style, and/or intensity. All tracers of productivity and terrigenous provenance

  12. Mechanical behaviour of a friction stir spot welding lap under static loading

    NASA Astrophysics Data System (ADS)

    Herbelot, C.; Hoang, T. Dang; Imad, A.; Benseddiq, N.

    2011-01-01

    Friction stir spot welding (FSSW) is a recent welding method which takes advantage of being performed in the solid state and presents many benefits such as a lower heat-input, a reduction of residual stresses and an elimination of the solidification defects for example. The present study investigates, for fixed process parameters and tool geometry, the fracture and damage of a single-lap friction stir spot welding joints formed from thin sheets of aluminum alloy 6082 T6. An experimental approach was carried out in order to analyze the sequence of damage mechanisms using acoustic emission (A.E.) and measurement of fields by digital image correlation (D.I.C.) techniques simultaneously. The A.E. technique allows the monitoring of the evolution of acoustic activities by taking into account energy of the events. The D.I.C. technique confirms the damage scenarios after the treatment of strain field at any point near the fastener and especially between the exit hole and the shoulder footprint. The coupling of those two techniques allows to identify characteristic points and a breakdown of the load displacement curve in phases.

  13. Nondestructive Evaluation of Friction Stir-Welded Aluminum Alloy to Coated Steel Sheet Lap Joint

    NASA Astrophysics Data System (ADS)

    Das, H.; Kumar, A.; Rajkumar, K. V.; Saravanan, T.; Jayakumar, T.; Pal, Tapan Kumar

    2015-11-01

    Dissimilar lap joints of aluminum sheet (AA 6061) of 2 mm thickness and zinc-coated steel sheet of 1 mm thickness were produced by friction stir welding with different combinations of rotational speed and travel speed. Ultrasonic C- and B-scanning, and radiography have been used in a complementary manner for detection of volumetric (cavity and flash) and planar (de bond) defects as the defects are in micron level. Advanced ultrasonic C-scanning did not provide any idea about the defects, whereas B-scanning cross-sectional image showed an exclusive overview of the micron-level defects. A digital x-ray radiography methodology is proposed for quality assessment of the dissimilar welds which provide three-fold increase in signal-to-noise ratio with improved defect detection sensitivity. The present study clearly shows that the weld tool rotational speed and travel speed have a decisive role on the quality of the joints obtained by the friction stir welding process. The suitability of the proposed NDE techniques to evaluate the joint integrity of dissimilar FSW joints is thus established.

  14. Laser-assisted friction stir welding of aluminum alloy lap joints: microstructural and microhardness characterizations

    NASA Astrophysics Data System (ADS)

    Casalino, Giuseppe; Campanelli, Sabina L.; Contuzzi, Nicola; Angelastro, Andrea; Ludovico, Antonio D.

    2014-02-01

    Friction Stir Welding (FSW) is a solid-state joining process; i.e., no melting occurs. The welding process is promoted by the rotation and translation of an axis-symmetric non-consumable tool along the weld centerline. Thus, the FSW process is performed at much lower temperatures than conventional fusion welding, nevertheless it has some disadvantages. The laser Assisted Friction Stir Welding (LAFSW) combines a Friction Stir Welding machine and a laser system. Laser power is used to preheat and to plasticize the volume of the workpiece ahead of the rotating tool; the workpiece is then joined in the same way as in the conventional FSW process. In this work an Ytterbium fiber laser with maximum power of 4 kW and a commercial FSW machine were coupled. Both FSW and LAFSW tests were conducted on 3 mm thick 5754H111 aluminum alloy plates in lap joint configuration with a constant tool rotation rate and with different feed rates. The two processes were compared and evaluated in terms of differences in the microstructure and in the micro-hardness profile.

  15. Large-scale Advanced Prop-fan (LAP) hub/blade retention design report

    NASA Technical Reports Server (NTRS)

    Soule, Matthew

    1986-01-01

    The Large-scale Advanced Prop-fan (LAP) hub assembly forms a semi-rigid link between the blades, which provide the thrust, and the engine shaft, which provides the torque. The hub and tailshaft is a one piece partially forged part which is carburized, heat treated and machined. A single row ball bearing restrains each of the eight blades in the hub, while the tailshaft secures the propeller to the engine shaft with two cone seats that are preloaded against each other by the Prop-fan retaining nut. The hub also forms the support for the pitch change actuator system, the control and the spinner. The retention transmits the loads from the blades to the hub while allowing the changes in blade pitch. The single row ball bearing retention provides ease of maintenance by allowing individual blade replacement without dissassembly of the hub. It has a through hardened inner race which seats against the aluminum blade shank and an outer race which is integral with the barrel. The outer race area is carburized to achieve the hardness necessary to support the ball loads. The balls are kept from contact with each other by a separator. The rotational speed of the propeller keeps the retention submerged in the oil which is contained in the hub by a seal. Stress and strain analysis, material hardness requirements, weight predictions, and stiffness characteristics are discussed.

  16. Strength analysis of laser welded lap joint for ultra high strength steel

    NASA Astrophysics Data System (ADS)

    Jeong, Young Cheol; Kim, Cheol Hee; Cho, Young Tae; Jung, Yoon Gyo

    2013-12-01

    Several industries including the automotive industry have recently applied the process of welding high strength steel. High strength steel is steel that is harder than normal high strength steel, making it much stronger and stiffer. HSS can be formed in pieces that can be up to 10 to 15 percent thinner than normal steel without sacrificing strength, which enables weight reduction and improved fuel economy. Furthermore, HSS can be formed into complex shapes that can be welded into structural areas. This study is based on previous experiments and is aimed at establishing the stress distribution for laser welded high strength steel. Research on the stress distribution for laser welded high strength steel is conducted by using Solid Works, a program that analyzes the stress of a virtual model. In conclusion, we found that the stress distribution is changed depending on the shape of welded lap joint. In addition, the Influence of the stress distribution on welded high strength steel can be used to standard for high energy welding of high strength steel, and we can also predict the region in welded high strength steel that may cracked.

  17. Growth kinetics of Al–Fe intermetallic compounds during annealing treatment of friction stir lap welds

    SciTech Connect

    Movahedi, M.; Kokabi, A.H.; Seyed Reihani, S.M.; Najafi, H.; Farzadfar, S.A.; Cheng, W.J.; Wang, C.J.

    2014-04-01

    In this study, we explored the growth kinetics of the Al–Fe intermetallic (IM) layer at the joint interface of the St-12/Al-5083 friction stir lap welds during post-weld annealing treatment at 350, 400 and 450 °C for 30 to 180 min. Optical microscope (OM), field emission gun scanning electron microscope (FEG-SEM) and transmission electron microscope (TEM) were employed to investigate the structure of the weld zone. The thickness and composition of the IM layers were evaluated using image analysis system and electron back-scatter diffraction (EBSD), respectively. Moreover, kernel average misorientation (KAM) analysis was performed to evaluate the level of stored energy in the as-welded state. The results showed that the growth kinetics of the IM layer was not governed by a parabolic diffusion law. Presence of the IM compounds as well as high stored energy near the joint interface of the as-welded sample was recognized to be the origin of the observed deviation from the parabolic diffusion law. - Highlights: • This work provided a new insight into growth kinetics of Al–Fe IM thickness. • The growth kinetics of IM layer was not governed by a parabolic diffusion law. • IM near the joint interface was the origin of deviation from the parabolic law. • High stored energy at joint interface was origin of deviation from parabolic law.

  18. Design Considerations of Polishing Lap for Computer-Controlled Cylindrical Polishing Process

    NASA Technical Reports Server (NTRS)

    Khan, Gufran S.; Gubarev, Mikhail; Speegle, Chet; Ramsey, Brian

    2010-01-01

    The future X-ray observatory missions, such as International X-ray Observatory, require grazing incidence replicated optics of extremely large collecting area (3 m2) in combination with angular resolution of less than 5 arcsec half-power diameter. The resolution of a mirror shell depends ultimately on the quality of the cylindrical mandrels from which they are being replicated. Mid-spatial-frequency axial figure error is a dominant contributor in the error budget of the mandrel. This paper presents our efforts to develop a deterministic cylindrical polishing process in order to keep the mid-spatial-frequency axial figure errors to a minimum. Simulation studies have been performed to optimize the operational parameters as well as the polishing lap configuration. Furthermore, depending upon the surface error profile, a model for localized polishing based on dwell time approach is developed. Using the inputs from the mathematical model, a mandrel, having conical approximated Wolter-1 geometry, has been polished on a newly developed computer-controlled cylindrical polishing machine. We report our first experimental results and discuss plans for further improvements in the polishing process.

  19. Assessment Ground Safety Using Time Lap Vertical Gravity Gradient At The Subsidence Area

    NASA Astrophysics Data System (ADS)

    Rim, H. B.; Park, Y.; Lim, M.; Koo, S. B.; Kwon, B. D.

    2007-05-01

    We have carried out time-lap vertical gravity gradient (VGG) survey in order to assess the ground safety before and after grouting. The target area is new pavement through the rice field, and the area has subsidence problems because of excessive pumping for agricultural irrigation. Therefore, it has been reinforced with cement grouting avoiding subsidence. In this paper, we examined the change of subsurface density distribution due to cement grouting by means of VGG survey. VGG method is more sensitive to detect the change of near surface than gravity survey itself because VGG enhanced small variation of gravity anomaly. We gathered one line gravity data about 270m long at every 2m. VGG survey consisted of observations between the ground bottom and the top separated vertically about 1.5m with help of the ladder specially designed. According to result, VGG anomaly made the response of man-made waterway clearer than Bouguer anomaly in the middle part of the line. And VGG result showed changes of subsurface density distribution after grouting.

  20. Optical examination of load transfer in riveted lap joints using portable holographic interferometry

    NASA Astrophysics Data System (ADS)

    Shankar, Krishnakumar; Baird, John P.; Clark, Robert K.; Williamson, Hugh M.

    1997-03-01

    In mechanically fastened single lap joints, such as those employed on aircraft fuselage skin splices, there are two distinct mechanisms of load transfer. At low values of load the transfer occurs primarily through friction between the component sheets while at higher loads the load is transferred by friction as well as through bearing at the fasteners. The load level at which the bearing mode of load transfer comes into action significantly affects the fatigue life of the joint, since the fasteners are stressed only at loads above this threshold load value. The portable holographic interferometry testing system (PHITS) is a robust, portable and sensitive non-destructive inspection system which produces contours of relative out of plane displacement by the method of superposition. PHITS is applied here to monitor the load transfer mechanism and identify the threshold at which the bearing mode comes into effect. In the friction mode there is no relative displacement between the fasteners and the skin panels. In the bearing mode the fasteners are loaded, causing a distinct tipping of the rivets, which is readily observable in the fringe pattern of deflection contours recorded by the holographic system.

  1. Estimating the upper limit of gas production from Class 2 hydrate accumulations in the permafrost: 2. Alternative well designs and sensitivity analysis

    SciTech Connect

    Moridis, G.; Reagan, M.T.

    2011-01-15

    In the second paper of this series, we evaluate two additional well designs for production from permafrost-associated (PA) hydrate deposits. Both designs are within the capabilities of conventional technology. We determine that large volumes of gas can be produced at high rates (several MMSCFD) for long times using either well design. The production approach involves initial fluid withdrawal from the water zone underneath the hydrate-bearing layer (HBL). The production process follows a cyclical pattern, with each cycle composed of two stages: a long stage (months to years) of increasing gas production and decreasing water production, and a short stage (days to weeks) that involves destruction of the secondary hydrate (mainly through warm water injection) that evolves during the first stage, and is followed by a reduction in the fluid withdrawal rate. A well configuration with completion throughout the HBL leads to high production rates, but also the creation of a secondary hydrate barrier around the well that needs to be destroyed regularly by water injection. However, a configuration that initially involves heating of the outer surface of the wellbore and later continuous injection of warm water at low rates (Case C) appears to deliver optimum performance over the period it takes for the exhaustion of the hydrate deposit. Using Case C as the standard, we determine that gas production from PA hydrate deposits increases with the fluid withdrawal rate, the initial hydrate saturation and temperature, and with the formation permeability.

  2. Fast carry accumulator design

    NASA Technical Reports Server (NTRS)

    Mastin, W. C.

    1971-01-01

    Simple iterative accumulator combined with gated-carry, carry-completion detection, and skip-carry circuits produces three accumulators with decreased carry propagation times. Devices are used in machine control, measurement equipment, and computer applications to increase speed of binary addition. NAND gates are used in combining network.

  3. Combining the enrichment and accumulation step in non-axenic PHA production: Cultivation of Plasticicumulans acidivorans at high volume exchange ratios.

    PubMed

    Marang, Leonie; van Loosdrecht, Mark C M; Kleerebezem, Robbert

    2016-08-10

    The process for non-axenic polyhydroxyalkanoate (PHA) production from organic waste generally comprises three steps: acidogenic fermentation of the waste stream, enrichment of a PHA-producing culture, and production of the PHA. This study assesses the feasibility of combining the enrichment and production step. Harvesting PHA-rich biomass directly from the sequencing batch reactor (SBR) used for enrichment of the microbial culture reduces capital cost, but may increase downstream-processing cost if the PHA content is significantly lowered. Operating an acetate-fed SBR at a volume exchange ratio of 0.75 (18h cycles, 1 d SRT) allowed the production of biomass with 70wt% poly(3-hydroxybutyrate) (PHB) in a single-step process. By increasing the exchange ratio to 0.83 (20h cycles) the PHB content of the harvested biomass increased to 75wt%, but the operational stability decreased. SBR operation at these high exchange ratios makes that bacteria have to increase their growth rate and external substrate is available for relatively long periods. This allows the establishment of larger flanking populations and negatively affected the kinetic properties of Plasticicumulans acidivorans, the predominant organism. Maximizing the volume exchange ratio is, therefore, a suitable strategy to produce large amounts of PHA in the SBR, but does not ensure the enrichment of a culture with superior PHA productivity. PMID:27316831

  4. A new design of the LAPS land surface scheme for use over and through heterogeneous and non-heterogeneous surfaces: Numerical simulations and tests

    NASA Astrophysics Data System (ADS)

    Mihailovic, Dragutin T.; Lazic, Jelena; Leśny, Jacek; Olejnik, Janusz; Lalic, Branislava; Kapor, Darko; Cirisan, Ana

    2010-05-01

    Numerical simulations and tests with the recently redesigned land-air parameterization scheme (LAPS) are presented. In all experiments, supported either by one-point micrometeorological, 1D or 3D simulations, the attention has been directed to: (1) comparison of simulation outputs, expressing the energy transfer over and through heterogeneous and non-heterogeneous surfaces, versus observations and (2) analysis of uncertainties occurring in the solution of the energy balance equation at the land-air interface. To check the proposed method for aggregation of albedo, "propagating hole" sensitivity tests with LAPS over a sandstone rock grid cell have been performed with the forcing meteorological data for July 17, 1999 in Baxter site, Philadelphia (USA). Micrometeorological and biophysical measurements from the surface experiments conducted over crops and apple orchard in Serbia, Poland, Austria and France were used to test the operation of LAPS in calculating surface fluxes and canopy environment temperatures within and above plant covers of different densities. In addition, sensitivity tests with single canopy covers over the Central Europe region and comparison against the observations taken from SYNOP data using 3D simulations were made. Validation of LAPS performances over a solid surface has been done by comparison of 2 m air temperature observations against 5-day simulations over the Sahara Desert rocky ground using 3D model. To examine how realistically the LAPS simulates surface processes over a heterogeneous surface, we compared the air temperature measured at 2 m and that predicted by the 1D model with the LAPS as the surface scheme. Finally, the scheme behaviour over urban surface was tested by runs over different parts of a hypothetical urban area. The corresponding 1D simulations were carried out with an imposed meteorological dataset collected during HAPEX-MOBILHY experiment at Caumont (France). The quantities predicted by the LAPS compare well with the

  5. Photosynthesis and assimilate partitioning between carbohydrates and isoprenoid products in vegetatively active and dormant guayule: physiological and environmental constraints on rubber accumulation in a semiarid shrub

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The stems and roots of the desert shrub guayule, Parthenium argentatum, contain a significant amount of latex that can be used as a source of natural rubber. Photosynthesis and the levels of carbohydrates and volatile isoprenoid products were measured in guayule plants grown under simulated summer-...

  6. LAPS Lidar Measurements at the ARM Alaska Northslope Site (Support to FIRE Project)

    NASA Technical Reports Server (NTRS)

    Philbrick, C. Russell; Lysak, Daniel B., Jr.; Petach, Tomas M.; Esposito, Steven T.; Mulik, Karoline R.

    1998-01-01

    This report consists of data summaries of the results obtained during the May 1998 measurement period at Barrow Alaska. This report does not contain any data interpretation or analysis of the results which will follow this activity. This report is forwarded with a data set on magnetic media which contains the reduced data from the LAPS lidar in 15 minute intervals. The data was obtained during the period 15-30 May 1998. The measurement period overlapped with several aircraft flights conducted by NASA as part of the FIRE project. The report contains a summary list of the data obtained plus figures that have been prepared to help visualize the measurement periods. The order of the presentation is as follows: Section 1. A copy of the Statement of Work for the planned activity of the second measurement period at the ARM Northslope site is provided. Section 2. A list of the data collection periods shows the number of one minute data records stored during each hour of operation and the corresponding size (Mbytes) of the one hour data folders. The folder and file names are composed from the year, month, day, hour and minute. The date/time information is given in UTC for easier comparison with other data sets. Section 3. A set of 4 comparisons between the LAPS lidar results and the sondes released by the ARM scientists from a location nearby the lidar. The lidar results show the +/- 1 sigma statistical error on each of the independent 75 m altitude bins of the data. This set of 4 comparisons was used to set and validate the calibration value which was then used for the complete data set. Section 4. A set of false color figures with up to 10 hours of specific humidity measurements are shown in each graph. Two days of measurements are shown on each page. These plots are crude representations of the data and permit a survey which indicates when the clouds were very low or where interesting events may occur in the results. These plots are prepared using the real time sequence

  7. Calmodulin controls liver proliferation via interactions with C/EBPbeta-LAP and C/EBPbeta-LIP.

    PubMed

    Orellana, Daniel; Liu, Xiaoying; Wang, Gou-Li; Jin, Jingling; Iakova, Polina; Timchenko, Nikolai A

    2010-07-23

    A truncated isoform of C/EBPbeta, C/EBPbeta-LIP, is required for liver proliferation. This isoform is expressed at high levels in proliferating liver and in liver tumors. However, high levels of C/EBPbeta-LIP are also observed in non-proliferating livers during acute phase response (APR). In this paper we present mechanisms by which liver regulates activities of C/EBPbeta-LIP. We found that calmodulin (CaM) inhibits the ability of C/EBPbeta-LIP to promote liver proliferation during APR through direct interactions. This activity of CaM is under negative control of Ca(2+), which is reduced in nuclei of livers with APR, whereas it is increased in nuclei of proliferating livers. A mutant CaM, which does not interact with C/EBPbeta-LIP, also fails to inhibit the growth promotion activity of C/EBPbeta-LIP. Down-regulation of CaM in livers of LPS-treated mice causes liver proliferation via activation of C/EBPbeta-LIP. Overexpression of C/EBPbeta-LIP above levels of CaM also initiates liver proliferation in LPS-treated mice. In addition, CaM regulates transcriptional activity of another isoform of C/EBPbeta, C/EBPbeta-LAP, and might control liver biology through the regulation of both isoforms of C/EBPbeta. In searching for molecular mechanisms by which C/EBPbeta-LIP promotes cell proliferation, we found that C/EBPbeta-LIP releases E2F.Rb-dependent repression of cell cycle genes by a disruption of E2F1.Rb complexes and by a direct interaction with E2F-dependent promoters. CaM inhibits these growth promotion activities of C/EBPbeta-LIP and, therefore, supports liver quiescence. Thus, our findings discover a new pathway of the regulation of liver proliferation that involves calcium-CaM signaling. PMID:20498378

  8. Ar-40/Ar-39 Age of Hornblende-bearing R Chondrite LAP 04840

    NASA Technical Reports Server (NTRS)

    Righter, K.; Cosca, M.

    2014-01-01

    Chondrites have a complex chronology due to several variables affecting and operating on chondritic parent bodies such as radiogenic heating, pressure and temperature variation with depth, aqueous alteration, and shock or impact heating [1]. Unbrecciated chondrites can record ages from 4.56 to 4.4 Ga that represent cooling in small parent bodies. Some brecciated chondrites exhibit younger ages (<<4 to 4.4 Ga) that may reflect the age of brecciation, disturbance, or shock and impact events (<< 4 Ga). A unique R chondrite was recently found in the LaPaz Icefield of Antarctica - LAP 04840 [2]. This chondrite contains approx.15% hornblende and trace amounts of biotite, making it the first of its kind. Studies have revealed an equigranular texture, mineral equilibria yielding equilibration near 650-700 C and 250-500 bars, hornblende that is dominantly OH-bearing (very little Cl or F), and high D/H ratios [8,9,10]. To help gain a better understanding of the origin of this unique sample, we have measured the Ar-40/Ar-39 age. Age of 4.290 +/- 0.030 Ga is younger than one would expect for a sample that has cooled within a small body [4], and one might instead attribute the age to a younger shock event, On the other hand, there is no evidence for extensive shock in this meteorite (shock stage S2; [3]), so this sample may have been reannealed after the shock event. This age is similar to Ar-Ar ages determined for some other R chondrites

  9. The mechanics and tribology of fretting fatigue with application to riveted lap joints

    NASA Astrophysics Data System (ADS)

    Szolwinski, Matthew Paul

    Fretting is the synergistic combination of wear, corrosion, and fatigue damage mechanisms driven by the partial slip of contacting surfaces. The surface microslip and near-surface contact stresses associated with fretting can lead to severe reduction in service lifetimes of contacting components as diversified as bearings, turbine blades and mechanically-fastened joints, both structural and biological. This tribologically induced degradation has come under close scrutiny by those responsible for maintaining aging fleets of both commercial and military aircraft. Thus a critical need exists for predicting fretting crack nucleation in riveted aluminum. aircraft joints. Fulfilling this need requires characterizing both the near-surface mechanics and intimately-related tribology of fretting. To this end, a well characterized experimental setup has been developed to generate carefully controlled and monitored fretting contacts to investigate the nature of the near-surface conditions. Included in this investigation were in-situ observations of the fretting contact stress field via a non-invasive thermal imaging technique and a characterization of the evolution of friction under partial slip conditions. With specific qualitative and quantitative understanding of these near-surface conditions, a series of fretting fatigue experiments have been conducted to validate a mechanics-based model for predicting fretting fatigue crack nucleation. Finally, efforts have been directed toward extending this understanding of fretting crack nucleation to riveted aircraft structure through modeling of the riveting process and a related experimental program designed to link riveting process parameters and fretting damage in single-lap joint structures. This work focuses specifically on determination of the residual stresses induced during rivet installation and the morphological characterization of fretting fatigue damage in the riveted test specimens manufactured under controlled

  10. A feasibility study for experimentally determining dynamic force distribution in a lap joint.

    SciTech Connect

    Mayes, Randall Lee

    2013-11-01

    Developing constitutive models of the physics in mechanical joints is currently stymied by inability to measure forces and displacements within the joint. The current state of the art estimates whole joint stiffness and energy loss per cycle from external measured force input and one or two acceleration responses. To validate constitutive models beyond this state requires a measurement of the distributed forces and displacements at the joint interface. Unfortunately, introducing measurement devices at the interface completely disrupts the desired physics. A feasibility study is presented for a non-intrusive method of solving for the interface dynamic forces from an inverse problem using full field measured responses. The responses come from the viewable surface of a beam. The noise levels associated with digital image correlation and continuous scanning laser Doppler velocimetry are evaluated from typical beam experiments. Two inverse problems are simulated. One utilizes the extended Sum of Weighted Accelerations Technique (SWAT). The second is a new approach dubbed the method of truncated orthogonal forces. These methods are much more robust if the contact patch geometry is well identified. Various approaches to identifying the contact patch are investigated, including ion marker tracking, Prussian blue and ultrasonic measurements. A typical experiment is conceived for a beam which has a lap joint at one end with a single bolt connecting it to another identical beam. In a virtual test using the beam finite element analysis, it appears that the SWAT inverse method requires evaluation of too many coefficients to adequately identify the force distribution to be viable. However, the method of truncated orthogonal forces appears viable with current digital image correlation (and probably other) imaging techniques.

  11. Propagation of ultrasonic guided waves in lap-shear adhesive joints

    NASA Astrophysics Data System (ADS)

    Lanza di Scalea, Francesco; Rizzo, Piervincenzo; Marzani, Alessandro

    2004-07-01

    This paper deals with the propagation of ultrasonic guided waves in adhesively-bonded lap-shear joints. The topic is relevant to ultrasonic bond inspection in aerospace components. Specifically, the propagation of the lowest-order, antisymmetric a0 mode through the joint is examined. This mode can be easily generated and detected in the field due to the predominant out-of-plane displacements at the surface of the test piece. An important aspect is the mode conversion at the boundaries between the single-plate adherends and the multilayer overlap. The a0 strength of transmission is studied for three different bond states in aluminum joints, namely a fully cured adhesive bond, a poorly cured adhesive bond, and a slip bond. Theoretical predictions based on the Global Matrix Method indicate that the dispersive behavior of the guided waves in the multilayer overlap is highly dependent on bond state. Experimental tests of the joints are conducted by a hybrid, broadband laser/air-coupled ultrasonic setup in a through-transmission configuration. This system does not require any wet coupling and it can be moved flexibly across the test piece. The Gabor Wavelet transform is employed to extract energy transmission coefficients in the 100 kHz - 1.4 MHz range for the three different bond states examined. The cross-sectional mode shapes of the guided waves are shown to have a substantial role in the energy transfer through the joint. A rationale for the selection of the a0 excitation frequencies highly sensitive to bond state will be given.

  12. Ternatin, an anti-inflammatory flavonoid, inhibits thioglycolate-elicited rat peritoneal neutrophil accumulation and LPS-activated nitric oxide production in murine macrophages.

    PubMed

    Rao, V S N; Paiva, L A F; Souza, M F; Campos, A R; Ribeiro, R A; Brito, G A C; Teixeira, M J; Silveira, E R

    2003-09-01

    Ternatin, an anti-inflammatory flavonoid from Egletes viscosa Less., was examined for its possible influence on thioglycolate-elicited neutrophil influx into the rat peritoneal cavity in vivo and nitric oxide production in lipopolysaccharide (LPS)-activated mouse peritoneal macrophages ex vivo. The neutrophil influx induced by thioglycolate was found to be significantly lower in ternatin (25 and 50 mg/kg, s. c.) pre-treated rats with a similar magnitude of inhibition produced by dexamethasone (1 mg/kg, s. c.), a known anti-inflammatory agent. Also, peritoneal macrophages from ternatin (25 mg/kg)-treated mice that were exposed to LPS demonstrated significantly less production of nitric oxide (NO). These results suggest that ternatin exerts its anti-inflammatory action, at least in part, through inhibition of neutrophil migration and modulation of macrophage function. PMID:14598213

  13. Ascorbate accumulation during sulphur deprivation and its effects on photosystem II activity and H2 production of the green alga Chlamydomonas reinhardtii.

    PubMed

    Nagy, Valéria; Vidal-Meireles, André; Tengölics, Roland; Rákhely, Gábor; Garab, Győző; Kovács, László; Tóth, Szilvia Z

    2016-07-01

    In nature, H2 production in Chlamydomonas reinhardtii serves as a safety valve during the induction of photosynthesis in anoxia, and it prevents the over-reduction of the photosynthetic electron transport chain. Sulphur deprivation of C. reinhardtii also triggers a complex metabolic response resulting in the induction of various stress-related genes, down-regulation of photosynthesis, the establishment of anaerobiosis and expression of active hydrogenase. Photosystem II (PSII) plays dual role in H2 production because it supplies electrons but the evolved O2 inhibits the hydrogenase. Here, we show that upon sulphur deprivation, the ascorbate content in C. reinhardtii increases about 50-fold, reaching the mM range; at this concentration, ascorbate inactivates the Mn-cluster of PSII, and afterwards, it can donate electrons to tyrozin Z(+) at a slow rate. This stage is followed by donor-side-induced photoinhibition, leading to the loss of charge separation activity in PSII and reaction centre degradation. The time point at which maximum ascorbate concentration is reached in the cell is critical for the establishment of anaerobiosis and initiation of H2 production. We also show that ascorbate influenced H2 evolution via altering the photosynthetic electron transport rather than hydrogenase activity and starch degradation. PMID:26714836

  14. The effect of age and microstructural white matter integrity on lap time variation and fast-paced walking speed.

    PubMed

    Tian, Qu; Ferrucci, Luigi; Resnick, Susan M; Simonsick, Eleanor M; Shardell, Michelle D; Landman, Bennett A; Venkatraman, Vijay K; Gonzalez, Christopher E; Studenski, Stephanie A

    2016-09-01

    Macrostructural white matter damage (WMD) is associated with less uniform and slower walking in older adults. The effect of age and subclinical microstructural WM degeneration (a potentially earlier phase of WM ischemic damage) on walking patterns and speed is less clear. This study examines the effect of age on the associations of regional microstructural WM integrity with walking variability and speed, independent of macrostructural WMD. This study involved 493 participants (n = 51 young; n = 209 young-old; n = 233 old-old) from the Baltimore Longitudinal Study of Aging. All completed a 400-meter walk test and underwent a concurrent brain MRI with diffusion tensor imaging. Microstructural WM integrity was measured as fractional anisotropy (FA). Walking variability was measured as trend-adjusted variation in time over ten 40-meter laps (lap time variation, LTV). Fast-paced walking speed was assessed as mean lap time (MLT). Multiple linear regression models of FA predicting LTV and MLT were adjusted for age, sex, height, weight, and WM hyperintensities. Independent of WM hyperintensities, lower FA in the body of the corpus callosum was associated with higher LTV and longer MLT only in the young-old. Lower FA in superior longitudinal, inferior fronto-occipital, and uncinate fasciculi, the anterior limb of the internal capsule, and the anterior corona radiate was associated with longer MLT only in the young-old. While macrostructural WMD is known to predict more variable and slower walking in older adults, microstructural WM disruption is independently associated with more variable and slower fast-paced walking only in the young-old. Disrupted regional WM integrity may be a subclinical contributor to abnormal walking at an earlier phase of aging. PMID:26399234

  15. Portable e-Tongue based on Multi-channel LAPS Array with PVC Membrane for Rapid Environment Detection

    NASA Astrophysics Data System (ADS)

    Ha, D.; Yu, H.; Hu, N.; Wu, C. X.; Zhou, J.; Kirsanov, Dmitry; Legin, Andrey; Wang, P.

    2011-09-01

    A new kind of portable e-Tongue based on multi-channel LAPS array with PVC membrane has been designed for the rapid detection of environment situation, especially the seawater. It has the great advantages of depositing membranes which are offered by Chemistry Department, Saint-Petersburg State University on the sensors artificially with convenience and efficiency. To detect various heavy metal ions (Pb2+, Cd2+, Zn2+) simultaneously, respective Polyvinyl Chloride (PVC) membrane could be prepared on the surface of the silicon-based sensor in different channel.

  16. Experiments and simulation for 6061-T6 aluminum alloy resistance spot welded lap joints

    NASA Astrophysics Data System (ADS)

    Florea, Radu Stefanel

    This comprehensive study is the first to quantify the fatigue performance, failure loads, and microstructure of resistance spot welding (RSW) in 6061-T6 aluminum (Al) alloy according to welding parameters and process sensitivity. The extensive experimental, theoretical and simulated analyses will provide a framework to optimize the welding of lightweight structures for more fuel-efficient automotive and military applications. The research was executed in four primary components. The first section involved using electron back scatter diffraction (EBSD) scanning, tensile testing, laser beam profilometry (LBP) measurements, and optical microscopy(OM) images to experimentally investigate failure loads and deformation of the Al-alloy resistance spot welded joints. Three welding conditions, as well as nugget and microstructure characteristics, were quantified according to predefined process parameters. Quasi-static tensile tests were used to characterize the failure loads in specimens based upon these same process parameters. Profilometer results showed that increasing the applied welding current deepened the weld imprints. The EBSD scans revealed the strong dependency between the grain sizes and orientation function on the process parameters. For the second section, the fatigue behavior of the RSW'ed joints was experimentally investigated. The process optimization included consideration of the forces, currents, and times for both the main weld and post-heating. Load control cyclic tests were conducted on single weld lap-shear joint coupons to characterize the fatigue behavior in spot welded specimens. Results demonstrate that welding parameters do indeed significantly affect the microstructure and fatigue performance for these welds. The third section comprised residual strains of resistance spot welded joints measured in three different directions, denoted as in-plane longitudinal, in-plane transversal, and normal, and captured on the fusion zone, heat affected zone

  17. Neurodegeneration with Brain Iron Accumulation

    MedlinePlus

    ... Diversity Find People About NINDS NINDS Neurodegeneration with Brain Iron Accumulation Information Page Synonym(s): Hallervorden-Spatz Disease, ... done? Clinical Trials Organizations What is Neurodegeneration with Brain Iron Accumulation? Neurodegeneration with brain iron accumulation (NBIA) ...

  18. Multiple forms of octopine dehydrogenase in Strombus luhuanus (mollusca, gastropoda, strombidae): genetic basis of polymorphism, properties of the enzymes, and relationship between the octopine dehydrogenase phenotype and the accumulation of anaerobic end products during exercise.

    PubMed

    Baldwin, J; England, W R

    1982-10-01

    Octopine dehydrogenase (ODH) is electrophoretically polymorphic in the gastropod mollusk Strombus luhuanus. The frequencies of the six electrophoretic phenotypes in the Heron Island population, together with the molecular weight values of 38,000 obtained for each of the three forms of the enzyme, demonstrate that the monomeric enzyme is encoded by three codominant alleles at a single locus. The purified allozymes are indistinguishable in terms of Km values for substrates, product inhibition by octopine and NAD, pH optima, and substrate inhibition by pyruvate. No statistically significant correlations were found between the ODH phenotype and the maximum activities of ODH or alanopine dehydrogenase, the capacity for anaerobic muscle work, or the accumulation of octopine or strombine/alanopine during exercise. It would appear that the ODH allozymes may be functionally equivalent both in vitro and in vivo. PMID:7181845

  19. Plastids and Carotenoid Accumulation.

    PubMed

    Li, Li; Yuan, Hui; Zeng, Yunliu; Xu, Qiang

    2016-01-01

    Plastids are ubiquitously present in plants and are the organelles for carotenoid biosynthesis and storage. Based on their morphology and function, plastids are classified into various types, i.e. proplastids, etioplasts, chloroplasts, amyloplasts, and chromoplasts. All plastids, except proplastids, can synthesize carotenoids. However, plastid types have a profound effect on carotenoid accumulation and stability. In this chapter, we discuss carotenoid biosynthesis and regulation in various plastids with a focus on carotenoids in chromoplasts. Plastid transition related to carotenoid biosynthesis and the different capacity of various plastids to sequester carotenoids and the associated effect on carotenoid stability are described in light of carotenoid accumulation in plants. PMID:27485226

  20. Comparison of Peritoneal Adhesion Formation in Bowel Retraction by Cotton Towels Versus the Silicone Lap Pak Device in a Rabbit Model

    PubMed Central

    Liu, Brian G.; Ruben, Dawn S.; Renz, Wolfgang; Santillan, Antonio; Kubisen, Steven J.; Harmon, John W.

    2011-01-01

    Objective: Manipulation of cotton operating room towels within the abdominal cavity in open abdominal surgery has been associated with the formation of peritoneal adhesions. In a rabbit model, the use of standard cotton operating room towels is compared to the Lap Pak, a silicone bowel-packing device, to determine the potential for reducing the risk of adhesions. Methods: Thirty rabbits were randomly assigned to 3 groups. The rabbits underwent a sham surgery with incision only (n = 10), placement of operating room towels (n = 10), or placement of a Lap Pak (n = 10). After 14 days, the rabbits were sacrificed and the peritoneal cavity explored for adhesions. The number, tenacity, ease of dissection, and density of adhesions were recorded, and the adhesions quantitatively graded using a Modified Hopkins Adhesion scoring system. Results: The operating room towel group had an average adhesion score of 2.5, and 8 (80%) rabbits developed adhesions. The sham group had an average adhesion score of 0.3 and one rabbit (10%) developed adhesions. The Lap Pak group had an average adhesion score of 0.2 and 1 rabbit (10%) developed adhesions. The frequency and severity of adhesions in the operating room towel group were significantly greater from that of the baseline sham group. There was no significant difference between the Lap Pak and sham groups. Conclusions: In this rabbit laparotomy model, the use of the Lap Pak to retract the bowels resulted in significantly fewer adhesions compared to cotton operating room towels. Lap Pak may be beneficial for bowel packing in general abdominal surgeries. PMID:22096614

  1. Molecular Approaches to Genetically Improve the Accumulation of Health-Promoting Secondary Metabolites in Staple Crops—A Case Study: The Lipoxygenase-B1 Genes and Regulation of the Carotenoid Content in Pasta Products

    PubMed Central

    Borrelli, Grazia M.; Trono, Daniela

    2016-01-01

    Secondary metabolites, also known as phytochemicals, represent a large subset of plant molecules that include compounds with health-promoting effects. Indeed, a number of epidemiological studies have shown that, when taken regularly and in adequate amounts, these molecules can have long-term beneficial effects on human health, through reduction of the incidence of degenerative diseases, such as cardiovascular diseases, obesity, diabetes, and cancer. As the dietary intake of these phytochemicals is often inadequate, various strategies are in use to improve their content in staple crops, and the end-products thereof. One of the most effective strategies is crop improvement through genetic approaches, as this is the only way to generate new cultivars in which the high accumulation of a given phytochemical is stably fixed. Efforts to genetically improve quality traits are rapidly evolving, from classical breeding to molecular-assisted approaches; these require sound understanding of the molecular bases underlying the traits, to identify the genes/alleles that control them. This can be achieved through global analysis of the metabolic pathway responsible for phytochemical accumulation, to identify the link between phytochemical content and the activities of key enzymes that regulate the metabolic pathway, and between the key enzymes and their encoding genes/alleles. Once these have been identified, they can be used as markers for selection of new improved genotypes through biotechnological approaches. This review provides an overview of the major health-promoting properties shown to be associated with the dietary intake of phytochemicals, and describes how molecular approaches provide means for improving the health quality of edible crops. Finally, a case study is illustrated, of the identification in durum wheat of the Lipoxygenase-B1 genes that control the final carotenoid content in semolina-based foods, such as pasta products. PMID:27455242

  2. Molecular Approaches to Genetically Improve the Accumulation of Health-Promoting Secondary Metabolites in Staple Crops-A Case Study: The Lipoxygenase-B1 Genes and Regulation of the Carotenoid Content in Pasta Products.

    PubMed

    Borrelli, Grazia M; Trono, Daniela

    2016-01-01

    Secondary metabolites, also known as phytochemicals, represent a large subset of plant molecules that include compounds with health-promoting effects. Indeed, a number of epidemiological studies have shown that, when taken regularly and in adequate amounts, these molecules can have long-term beneficial effects on human health, through reduction of the incidence of degenerative diseases, such as cardiovascular diseases, obesity, diabetes, and cancer. As the dietary intake of these phytochemicals is often inadequate, various strategies are in use to improve their content in staple crops, and the end-products thereof. One of the most effective strategies is crop improvement through genetic approaches, as this is the only way to generate new cultivars in which the high accumulation of a given phytochemical is stably fixed. Efforts to genetically improve quality traits are rapidly evolving, from classical breeding to molecular-assisted approaches; these require sound understanding of the molecular bases underlying the traits, to identify the genes/alleles that control them. This can be achieved through global analysis of the metabolic pathway responsible for phytochemical accumulation, to identify the link between phytochemical content and the activities of key enzymes that regulate the metabolic pathway, and between the key enzymes and their encoding genes/alleles. Once these have been identified, they can be used as markers for selection of new improved genotypes through biotechnological approaches. This review provides an overview of the major health-promoting properties shown to be associated with the dietary intake of phytochemicals, and describes how molecular approaches provide means for improving the health quality of edible crops. Finally, a case study is illustrated, of the identification in durum wheat of the Lipoxygenase-B1 genes that control the final carotenoid content in semolina-based foods, such as pasta products. PMID:27455242

  3. Impact of CRFR1 Ablation on Amyloid-β Production and Accumulation in a Mouse Model of Alzheimer’s Disease

    PubMed Central

    Campbell, Shannon N.; Zhang, Cheng; Roe, Allyson D.; Lee, Nickey; Lao, Kathleen U.; Monte, Louise; Donohue, Michael C.; Rissman, Robert A.

    2015-01-01

    Stress exposure and the corticotropin-releasing factor (CRF) system have been implicated as mechanistically involved in both Alzheimer’s disease (AD) and associated rodent models. In particular, the major stress receptor, CRF receptor type 1 (CRFR1), modulates cellular activity in many AD-relevant brain areas, and has been demonstrated to impact both tau phosphorylation and amyloid-β (Aβ) pathways. The overarching goal of our laboratory is to develop and characterize agents that impact the CRF signaling system as disease-modifying treatments for AD. In the present study, we developed a novel transgenic mouse to determine whether partial or complete ablation of CRFR1 was feasible in an AD transgenic model and whether this type of treatment could impact Aβ pathology. Double transgenic AD mice (PSAPP) were crossed to mice null for CRFR1; resultant CRFR1 heterozygous (PSAPP-R1+/−) and homozygous (PSAPP-R1−/−) female offspring were used at 12 months of age to examine the impact of CRFR1 disruption on the severity of AD Aβ levels and pathology. We found that both PSAPP-R1+/− and PSAPP-R1−/− had significantly reduced Aβ burden in the hippocampus, insular, rhinal, and retrosplenial cortices. Accordingly, we observed dramatic reductions in Aβ peptides and AβPP-CTFs, providing support for a direct relationship between CRFR1 and Aβ production pathways. In summary, our results suggest that interference of CRFR1 in an AD model is tolerable and is efficacious in impacting Aβ neuropathology. PMID:25697705

  4. Antagonism of the presumed presynaptic action of L-AP4 on GABAergic transmission in the ventrobasal thalamus by the novel mGluR antagonist MPPG.

    PubMed

    Salt, T E; Turner, J P

    1996-02-01

    The metabotropic glutamate receptor (mGluR) agonists CCG-I and L-AP4, acting at Group II and Group III mGluRs respectively, can reduce GABAergic synaptic inhibition on single neurones in the rat thalamus in vivo via a presumed presynaptic mechanism. The actions of L-AP4 were antagonized by (+/-)-alpha-methyl-4-phosphonophenylglycine (MPPG), whereas CCG-I was significantly less affected. Thus MPPG may be a useful tool for detecting physiological roles for Group III mGluRs. PMID:8734494

  5. Ultrasonic inspection of multiple-rivet-hole lap joint cracks using global analysis with local finite element approach

    NASA Astrophysics Data System (ADS)

    Bhuiyan, Yeasin; Shen, Yanfeng; Giurgiutiu, Victor

    2016-04-01

    Ultrasonic inspection of multiple-rivet-hole lap joint cracks has been introduced using combined analytical and finite element approach (CAFA). Finite element analyses have been performed on local damage area in spite of the whole large structure and transfer function based analytical model is used to analyze the full structure. "Scattered cube" of complex valued wave damage interaction coefficient (WDIC) that involves scattering and mode conversion of Lamb waves around the damage is used as coupling between analytical and FEM simulation. WDIC is captured for multiple angles of incident Lamb mode (S0 and A0) over the frequency domain to analyze the cracks of multiple-rivet-hole lap joint. By analyzing the scattered cube of WDICs over the frequency domain and azimuthal angles the optimum parameters can be determined for each angle of incidence and the most sensitive signals are obtained using WaveformRevealer2D (WFR2D). These sensitive signals confirm the detection of the butterfly cracks in rivet holes through the installment of the transmitting and sensing PWASs in the proper locations and selecting the right frequency of excitation.

  6. Transcriptional regulation of miR-146b by C/EBPβ LAP2 in esophageal cancer cells

    SciTech Connect

    Li, Junxia; Shan, Fabo; Xiong, Gang; Wang, Ju-Ming; Wang, Wen-Lin; Xu, Xueqing; Bai, Yun

    2014-03-28

    Highlights: • MiR-146b promotes esophageal cancer cell proliferation. • MiR-146b inhibits esophageal cancer cell apoptosis. • C/EBPβ directly binds to miR-146b promoter conserved region. • MiR-146b is up-regulated by C/EBPβ LAP2 transcriptional activation. - Abstract: Recent clinical study indicated that up-regulation of miR-146b was associated with poor overall survival of patients in esophageal squamous cell carcinoma. However, the underlying mechanism of miR-146b dysregulation remains to be explored. Here we report that miR-146b promotes cell proliferation and inhibits cell apoptosis in esophageal cancer cell lines. Mechanismly, two C/EBPβ binding motifs are located in the miR-146b promoter conserved region. Among the three isoforms of C/EBPβ, C/EBPβ LAP2 positively regulated miR-146b expression and increases miR-146b levels in a dose-dependent manner through transcription activation of miR-146b gene. Together, these results suggest a miR-146b regulatory mechanism involving C/EBPβ, which may contribute to the up-regulation of miR-146b in esophageal squamous cell carcinoma.

  7. Ultrasonic Welding of Thermoplastic Composite Coupons for Mechanical Characterization of Welded Joints through Single Lap Shear Testing.

    PubMed

    Villegas, Irene F; Palardy, Genevieve

    2016-01-01

    This paper presents a novel straightforward method for ultrasonic welding of thermoplastic-composite coupons in optimum processing conditions. The ultrasonic welding process described in this paper is based on three main pillars. Firstly, flat energy directors are used for preferential heat generation at the joining interface during the welding process. A flat energy director is a neat thermoplastic resin film that is placed between the parts to be joined prior to the welding process and heats up preferentially owing to its lower compressive stiffness relative to the composite substrates. Consequently, flat energy directors provide a simple solution that does not require molding of resin protrusions on the surfaces of the composite substrates, as opposed to ultrasonic welding of unreinforced plastics. Secondly, the process data provided by the ultrasonic welder is used to rapidly define the optimum welding parameters for any thermoplastic composite material combination. Thirdly, displacement control is used in the welding process to ensure consistent quality of the welded joints. According to this method, thermoplastic-composite flat coupons are individually welded in a single lap configuration. Mechanical testing of the welded coupons allows determining the apparent lap shear strength of the joints, which is one of the properties most commonly used to quantify the strength of thermoplastic composite welded joints. PMID:26890931

  8. Experimental and analytical program to determine strains in 737 LAP splice joints subjected to normal fuselage pressurization loads

    SciTech Connect

    Roach, D.P.; Jeong, D.Y.

    1996-02-01

    The Federal Aviation Administration Technical Center (FAATC) has initiated several research projects to assess the structural integrity of the aging commercial aircraft fleet. One area of research involves the understanding of a phenomenon known as ``Widespread Fatigue Damage`` or WFD, which refers to a type of multiple element cracking that degrades the damage tolerance capability of an aircraft structure. Research on WFD has been performed both experimentally and analytically including finite element modeling of fuselage lap splice joints by the Volpe Center. Fuselage pressurization tests have also been conducted at the FAA`s Airworthiness Assurance NDI Validation Center (AANC) to obtain strain gage data from select locations on the FAA/AANC 737 Transport Aircraft Test Bed. One-hundred strain channels were used to monitor five different lap splice bays including the fuselage skin and substructure elements. These test results have been used to evaluate the accuracy of the analytical models and to support general aircraft analysis efforts. This paper documents the strain fields measured during the AANC tests and successfully correlates the results with analytical predictions.

  9. In silico screening of novel inhibitors of M17 Leucine Amino Peptidase (LAP) of Plasmodium vivax as therapeutic candidate.

    PubMed

    Rout, Subhashree; Mahapatra, Rajani Kanta

    2016-08-01

    M17 LAP (Leucine Amino Peptidase) plays an important role in the hydrolysis of amino acids essential for growth and development of Plasmodium vivax (Pv), the pathogen causing malaria. In this paper a homology model of PvLAP was generated using MODELLER v9.15. From different in-silico methods such as structure based, ligand based and de novo drug designing a total of 90 compounds were selected for docking studies. A final list of 10 compounds was prepared. The study reported the identification of 2-[(3-azaniumyl-2-hydroxy-4-phenylbutanoyl) amino]-4-methylpentanoate as the best inhibitor in terms of docking score and pharmacophoric features. The reliability of the binding mode of the inhibitor is confirmed by molecular dynamics (MD) simulation study with GROMACS software for a simulation time of 20ns in water environment. Finally, in silico ADMET analysis of the inhibitors using MedChem Designer v3 evaluated the drug likeness of the best hits to be considered for industrial pharmaceutical research. PMID:27470355

  10. Chimpanzee accumulative stone throwing.

    PubMed

    Kühl, Hjalmar S; Kalan, Ammie K; Arandjelovic, Mimi; Aubert, Floris; D'Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M; Zuberbuehler, Klaus; Boesch, Christophe

    2016-01-01

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites. PMID:26923684

  11. Chimpanzee accumulative stone throwing

    PubMed Central

    Kühl, Hjalmar S.; Kalan, Ammie K.; Arandjelovic, Mimi; Aubert, Floris; D’Auvergne, Lucy; Goedmakers, Annemarie; Jones, Sorrel; Kehoe, Laura; Regnaut, Sebastien; Tickle, Alexander; Ton, Els; van Schijndel, Joost; Abwe, Ekwoge E.; Angedakin, Samuel; Agbor, Anthony; Ayimisin, Emmanuel Ayuk; Bailey, Emma; Bessone, Mattia; Bonnet, Matthieu; Brazolla, Gregory; Buh, Valentine Ebua; Chancellor, Rebecca; Cipoletta, Chloe; Cohen, Heather; Corogenes, Katherine; Coupland, Charlotte; Curran, Bryan; Deschner, Tobias; Dierks, Karsten; Dieguez, Paula; Dilambaka, Emmanuel; Diotoh, Orume; Dowd, Dervla; Dunn, Andrew; Eshuis, Henk; Fernandez, Rumen; Ginath, Yisa; Hart, John; Hedwig, Daniela; Ter Heegde, Martijn; Hicks, Thurston Cleveland; Imong, Inaoyom; Jeffery, Kathryn J.; Junker, Jessica; Kadam, Parag; Kambi, Mohamed; Kienast, Ivonne; Kujirakwinja, Deo; Langergraber, Kevin; Lapeyre, Vincent; Lapuente, Juan; Lee, Kevin; Leinert, Vera; Meier, Amelia; Maretti, Giovanna; Marrocoli, Sergio; Mbi, Tanyi Julius; Mihindou, Vianet; Moebius, Yasmin; Morgan, David; Morgan, Bethan; Mulindahabi, Felix; Murai, Mizuki; Niyigabae, Protais; Normand, Emma; Ntare, Nicolas; Ormsby, Lucy Jayne; Piel, Alex; Pruetz, Jill; Rundus, Aaron; Sanz, Crickette; Sommer, Volker; Stewart, Fiona; Tagg, Nikki; Vanleeuwe, Hilde; Vergnes, Virginie; Willie, Jacob; Wittig, Roman M.; Zuberbuehler, Klaus; Boesch, Christophe

    2016-01-01

    The study of the archaeological remains of fossil hominins must rely on reconstructions to elucidate the behaviour that may have resulted in particular stone tools and their accumulation. Comparatively, stone tool use among living primates has illuminated behaviours that are also amenable to archaeological examination, permitting direct observations of the behaviour leading to artefacts and their assemblages to be incorporated. Here, we describe newly discovered stone tool-use behaviour and stone accumulation sites in wild chimpanzees reminiscent of human cairns. In addition to data from 17 mid- to long-term chimpanzee research sites, we sampled a further 34 Pan troglodytes communities. We found four populations in West Africa where chimpanzees habitually bang and throw rocks against trees, or toss them into tree cavities, resulting in conspicuous stone accumulations at these sites. This represents the first record of repeated observations of individual chimpanzees exhibiting stone tool use for a purpose other than extractive foraging at what appear to be targeted trees. The ritualized behavioural display and collection of artefacts at particular locations observed in chimpanzee accumulative stone throwing may have implications for the inferences that can be drawn from archaeological stone assemblages and the origins of ritual sites. PMID:26923684

  12. Hybrid laser-arc welding of galvanized high-strength steels in a gap-free lap-joint configuration

    NASA Astrophysics Data System (ADS)

    Yang, Shanglu

    In order to meet the industry demands for increased fuel efficiency and enhanced mechanical and structural performance of vehicles as well as provided excellent corrosion resistance, more and more galvanized advanced high-strength steels (AHSS) have been used to fabricate automobile parts such as panels, bumpers, and front rails. The automotive industry has shown tremendous interest in using laser welding to join galvanized dual phase steels because of lower heat input and higher welding speed. However, the laser welding process tends to become dramatically unstable in the presence of highly pressurized zinc vapor because of the low boiling point of zinc, around 906°C, compared to higher melting point of steel, over 1500°C. A large number of spatters are produced by expelling the liquid metal from the molten pool by the pressurized zinc vapor. Different weld defects such as blowholes and porosities appear in the welds. So far, limited information has been reported on welding of galvanized high strength dual-phase steels in a gap-free lap joint configuration. There is no open literature on the successful attainment of defect-free welds from the laser or hybrid welding of galvanized high-strength steels. To address the significant industry demand, in this study, different welding techniques and monitoring methods are used to study the features of the welding process of galvanized DP steels in a gap-free lap joint configuration. The current research covers: (i) a feasibility study on the welding of galvanized DP 980 steels in a lap joint configuration using gas tungsten arc welding (GTAW), laser welding, hybrid laser/arc welding with the common molten pool, laser welding with the assistance of GTAW preheating source and hybrid laser-variable polarity gas tungsten arc welding (Laser-VPGTAW) techniques (Chapter 2-4); (ii) a welding process monitoring of the welding techniques including the use of machine vision and acoustic emission technique (Chapter 5); (iii

  13. Prevalence of Comorbidities and Baseline Characteristics of LAP-BAND AP® Subjects in the Helping Evaluate Reduction in Obesity (HERO) Study

    PubMed Central

    Dreyer, Nancy; Dixon, John B.; Okerson, Ted; Finkelstein, Eric A.; Globe, Denise

    2013-01-01

    Objective To describe the baseline characteristics in patients who chose placement of a LAP-BAND AP® System (LBAP) and participated in the Helping Evaluate Reduction in Obesity (HERO) Study across regions. Patients and Methods HERO is a five- year, prospective, multicenter, international study of patients with LBAP placement between July 22, 2009 and January 31, 2011. In addition to baseline and peri-surgery clinical data, seven follow up visits are scheduled at 3, 6 and 12 months, and annually through year five. Data collection included family and medical history, clinical outcomes, laboratory data, health-related quality of life (HRQoL), productivity, healthcare resource utilization, and adverse events. Results LBAP were placed in 1106 enrolled patients; 56.6% from the US, 26.3% from Europe, 7.1% from Canada, and 10.0% from Australia. The majority were female (n = 877 (79.3%)) with a mean age of 43 years (s.d. = 11.4) and mean body mass index of 45.1 kg/m2 (s.d. = 6.9). The most common comorbidities were hypertension (HTN) (overall  = 42.9%) and diabetes (overall 22.2%, with 27% from the US and 14% from Europe). Overall, less than 5% had a history of cardiovascular disease. The prevalence rates of HTN, diabetes and cardiovascular disease were significantly (p<0.001) higher in men than in women across all regions. Overall HRQoL also worsened with increasing BMI. Conclusions The HERO study is the first large, multinational and long-term registry with the LBAP. This study will provide real-world outcomes data on LAGB that will help inform patient choice, clinician treatment strategies, and payer reimbursement decisions. PMID:24260140

  14. Study on effect of 1,3-dimethyl urea doping on optical properties of L-arginine phosphate monohydrate (LAP) single crystal

    NASA Astrophysics Data System (ADS)

    Wankhade, Pratik M.; Muley, Gajanan G.

    Pure and 1,3-dimethyl urea doped L-arginine phosphate monohydrate (LAP) crystals were grown by a solution growth technique from aqueous solution at a constant temperature. The effect of dopant on the optical properties, crystal structure and second harmonic generation (SHG) efficiency was studied. Dopant modifies the SHG efficiency of the LAP crystal at a greater extent. The SHG efficiency of 0.01 mol% 1,3-dimethyl urea doped LAP crystal corresponds to 1.37 times more as compared to the pure LAP. Absorption and transmission were measured in the spectral range 190-1083 nm. The increase in the optical transparency of the doped crystal is reported. The band gap of the grown crystals has been determined. The presence of the dopant in the doped crystals was confirmed qualitatively by the FT-IR spectroscopy. A slight variation in unit cell parameters has been reported. Thermal and dielectric study of the doped crystal has also been presented.

  15. Vitamin A supplementation leads to increases in regulatory CD4+Foxp3+LAP+ T cells in mice.

    PubMed

    Medeiros, Samara R; Pinheiro-Rosa, Natalia; Lemos, Luisa; Loli, Flavia G; Pereira, Alline G; Santiago, Andrezza F; Pinter, Ester C; Alves, Andrea C; Oliveira, Jamil S; Cara, Denise C; Maioli, Tatiani U; Faria, Ana Maria C

    2015-10-01

    Dietary compounds, including micronutrients such as vitamin A and its metabolite retinoic acid, directly influence the development and function of the immune system. In this study, we show that either dietary deficiency of or supplementation with vitamin A had immunologic effects in mice that were fed these diets during their development (for 8 wk during the postweaning period). Deficient mice presented higher levels of interferon-γ, interleukin (IL)-6, transforming growth factor-β, IL-17, and IL-10 in the gut-associated lymphoid tissues and draining lymph nodes, indicating a proinflammatory shift in the gut mucosa. Serum immunoglobulin G levels also were elevated in these mice. Conversely, supplemented mice showed higher frequencies of CD4+Foxp3+LAP+ regulatory T cells in gut lymphoid tissues and spleen, suggesting that vitamin A supplementation in the diet may be beneficial in pathologic situations such as inflammatory bowel diseases. PMID:26004193

  16. Spectroscopic, energetic and metallographic investigations of the laser lap welding of AISI 304 using the response surface methodology

    NASA Astrophysics Data System (ADS)

    Rizzi, Domenico; Sibillano, Teresa; Pietro Calabrese, Paolo; Ancona, Antonio; Mario Lugarà, Pietro

    2011-07-01

    Spectroscopic signals originated by the laser-induced plasma optical emission have been simultaneously investigated together with energetic and metallographic analyses of CO 2 laser welded stainless steel lap joint, using the Response Surface Methodology. This statistical approach allowed us to study the influence of the laser beam power and the laser welding speed on the following response parameters: plasma plume electron temperature, joint penetration depth and melted area. A clear correlation has been found between all the investigated response parameters. The results have been shown to be consistent with quantitative considerations on the energy supplied to the workpiece as far as the laser power and travel speed were varied. The regression model obtained in this way could be a valuable starting point to develop a closed loop control of the weld penetration depth and the melted area in the investigated process window.

  17. THE KINETICS OF PENETRATION : VIII. TEMPORARY ACCUMULATION.

    PubMed

    Osterhout, W J; Kamerling, S E

    1934-03-20

    A model is described which throws light on the mechanism of accumulation. In the model used an external aqueous phase A is separated by a non-aqueous phase B (representing the protoplasm) from the artificial sap in C. A contains KOH and C contains HCl: they tend to mix by passing through the non-aqueous layer but much more KOH moves so that most of the KCl is formed in C, where the concentration of potassium becomes much greater than in A. This accumulation is only temporary for as the system approaches equilibrium the composition of A approaches identity with that of C, since all the substances present can pass through the non-aqueous layer. Such an approach to equilibrium may be compared to the death of the cell as the result of which accumulation disappears. During the earlier stages of the experiment potassium tends to go in as KOH and at the same time to go out as KCl. These opposing tendencies do not balance until the concentration of potassium inside becomes much greater than outside (hence potassium accumulates). The reason is that KCl, although its driving force be great, moves very slowly in B because its partition coefficient is low and in consequence its concentration gradient in B is small. This illustrates the importance of partition coefficients for penetration in models and in living cells. It also indicates that accumulation depends on the fact that permeability is greater for the ingoing compound of the accumulating substance than for the outgoing compound. Other things being equal, accumulation is increased by maintaining a low pH in C. Hence we may infer that anything which checks the production of acid in the living cell may be expected to check accumulation and growth. This model recalls the situation in Valonia and in most living cells where potassium accumulates as KCl, perhaps because it enters as KOH and forms KA in the sap (where A is an organic anion). In some plants potassium accumulates as KA but when HCl exists in the external

  18. 19 CFR 10.597 - Accumulation.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... States Free Trade Agreement Rules of Origin § 10.597 Accumulation. (a) Originating materials from the territory of one or more of the Parties that are used in the production of a good in the territory...

  19. 19 CFR 10.597 - Accumulation.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... States Free Trade Agreement Rules of Origin § 10.597 Accumulation. (a) Originating materials from the territory of one or more of the Parties that are used in the production of a good in the territory...

  20. 19 CFR 10.597 - Accumulation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... States Free Trade Agreement Rules of Origin § 10.597 Accumulation. (a) Originating materials from the territory of one or more of the Parties that are used in the production of a good in the territory...

  1. 19 CFR 10.597 - Accumulation.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY... States Free Trade Agreement Rules of Origin § 10.597 Accumulation. (a) Originating materials from the territory of one or more of the Parties that are used in the production of a good in the territory...

  2. Heat exchanger-accumulator

    DOEpatents

    Ecker, Amir L.

    1980-01-01

    What is disclosed is a heat exchanger-accumulator for vaporizing a refrigerant or the like, characterized by an upright pressure vessel having a top, bottom and side walls; an inlet conduit eccentrically and sealingly penetrating through the top; a tubular overflow chamber disposed within the vessel and sealingly connected with the bottom so as to define an annular outer volumetric chamber for receiving refrigerant; a heat transfer coil disposed in the outer volumetric chamber for vaporizing the liquid refrigerant that accumulates there; the heat transfer coil defining a passageway for circulating an externally supplied heat exchange fluid; transferring heat efficiently from the fluid; and freely allowing vaporized refrigerant to escape upwardly from the liquid refrigerant; and a refrigerant discharge conduit penetrating sealingly through the top and traversing substantially the length of the pressurized vessel downwardly and upwardly such that its inlet is near the top of the pressurized vessel so as to provide a means for transporting refrigerant vapor from the vessel. The refrigerant discharge conduit has metering orifices, or passageways, penetrating laterally through its walls near the bottom, communicating respectively interiorly and exteriorly of the overflow chamber for controllably carrying small amounts of liquid refrigerant and oil to the effluent stream of refrigerant gas.

  3. Solids Accumulation Scouting Studies

    SciTech Connect

    Duignan, M. R.; Steeper, T. J.; Steimke, J. L.

    2012-09-26

    The objective of Solids Accumulation activities was to perform scaled testing to understand the behavior of remaining solids in a Double Shell Tank (DST), specifically AW-105, at Hanford during multiple fill, mix, and transfer operations. It is important to know if fissionable materials can concentrate when waste is transferred from staging tanks prior to feeding waste treatment plants. Specifically, there is a concern that large, dense particles containing plutonium could accumulate in poorly mixed regions of a blend tank heel for tanks that employ mixing jet pumps. At the request of the DOE Hanford Tank Operations Contractor, Washington River Protection Solutions, the Engineering Development Laboratory of the Savannah River National Laboratory performed a scouting study in a 1/22-scale model of a waste staging tank to investigate this concern and to develop measurement techniques that could be applied in a more extensive study at a larger scale. Simulated waste tank solids: Gibbsite, Zirconia, Sand, and Stainless Steel, with stainless steel particles representing the heavier particles, e.g., plutonium, and supernatant were charged to the test tank and rotating liquid jets were used to mix most of the solids while the simulant was pumped out. Subsequently, the volume and shape of the mounds of residual solids and the spatial concentration profiles for the surrogate for heavier particles were measured. Several techniques were developed and equipment designed to accomplish the measurements needed and they included: 1. Magnetic particle separator to remove simulant stainless steel solids. A device was designed and built to capture these solids, which represent the heavier solids during a waste transfer from a staging tank. 2. Photographic equipment to determine the volume of the solids mounds. The mounds were photographed as they were exposed at different tank waste levels to develop a composite of topographical areas. 3. Laser rangefinders to determine the volume of

  4. ITER helium ash accumulation

    SciTech Connect

    Hogan, J.T.; Hillis, D.L.; Galambos, J.; Uckan, N.A. ); Dippel, K.H.; Finken, K.H. . Inst. fuer Plasmaphysik); Hulse, R.A.; Budny, R.V. . Plasma Physics Lab.)

    1990-01-01

    Many studies have shown the importance of the ratio {upsilon}{sub He}/{upsilon}{sub E} in determining the level of He ash accumulation in future reactor systems. Results of the first tokamak He removal experiments have been analysed, and a first estimate of the ratio {upsilon}{sub He}/{upsilon}{sub E} to be expected for future reactor systems has been made. The experiments were carried out for neutral beam heated plasmas in the TEXTOR tokamak, at KFA/Julich. Helium was injected both as a short puff and continuously, and subsequently extracted with the Advanced Limiter Test-II pump limiter. The rate at which the He density decays has been determined with absolutely calibrated charge exchange spectroscopy, and compared with theoretical models, using the Multiple Impurity Species Transport (MIST) code. An analysis of energy confinement has been made with PPPL TRANSP code, to distinguish beam from thermal confinement, especially for low density cases. The ALT-II pump limiter system is found to exhaust the He with maximum exhaust efficiency (8 pumps) of {approximately}8%. We find 1<{upsilon}{sub He}/{upsilon}{sub E}<3.3 for the database of cases analysed to date. Analysis with the ITER TETRA systems code shows that these values would be adequate to achieve the required He concentration with the present ITER divertor He extraction system.

  5. Cloning, expression, crystallization and preliminary X-ray crystallographic analysis of leucine aminopeptidase (LAP) from the pepA gene of Xanthomonas oryzae pv. oryzae

    PubMed Central

    Huynh, Kim-Hung; Natarajan, Sampath; Choi, Jeongyoon; Song, Na-Hyun; Kim, Jeong-Gu; Lee, Byoung-Moo; Ahn, Yeh-Jin; Kang, Lin-Woo

    2009-01-01

    Xanthomonas oryzae pv. oryzae (Xoo) causes the serious disease bacterial blight in rice. The pepA (Xoo0834) gene from Xoo is one of around 100 genes that have been selected for the design of antibacterial drugs. The pepA gene encodes leucine aminopeptidase (LAP), an exopeptidase that catalyzes the hydrolysis of leucine residues from the N-terminus of a protein or peptide. This enzyme was expressed in Escherichia coli, purified and crystallized, and preliminary X-ray structural studies have been carried out. The LAP crystal diffracted to 2.6 Å resolution and belonged to the cubic space group P213. The unit-cell volume of the crystal was compatible with the presence of two monomers in the asymmetric unit. PMID:19724142

  6. High Mobility Group Protein N5 (HMGN5) and Lamina-associated Polypeptide 2α (LAP2α) Interact and Reciprocally Affect Their Genome-wide Chromatin Organization*

    PubMed Central

    Zhang, Shaofei; Schones, Dustin E.; Malicet, Cedric; Rochman, Mark; Zhou, Ming; Foisner, Roland; Bustin, Michael

    2013-01-01

    The interactions of nuclear lamins with the chromatin fiber play an important role in regulating nuclear architecture and chromatin function; however, the full spectrum of these interactions is not known. We report that the N-terminal domain of the nucleosome-binding protein HMGN5 interacts with the C-terminal domain of the lamin-binding protein LAP2α and that these proteins reciprocally alter their interaction with chromatin. Chromatin immunoprecipitation analysis of cells lacking either HMGN5 or LAP2α reveals that loss of either protein affects the genome-wide distribution of the remaining partner. Our study identifies a new functional link between chromatin-binding and lamin-binding proteins. PMID:23673662

  7. Analysis of the Static and Fatigue Strenght of a Damage Tolerant 3D-Reinforced Joining Technology on Composite Single Lap Joints

    NASA Astrophysics Data System (ADS)

    Nogueira, A. C.; Drechsler, K.; Hombergsmeier, E.

    2012-07-01

    The increasing usage of carbon fiber reinforced plastics (CFRP) in aerospace together with the constant drive for fuel efficiency and lightweight design have imposed new challenges in next generation structural assemblies and load transfer efficient joining methods. To address this issue, an innovative technology, denominated Redundant High Efficiency Assembly (RHEA) joints, is introduced as a high-performance lightweight joint that combines efficient load transfer with good damage tolerance. A review of the ongoing research involving the RHEA joint technology, its through-thickness reinforcement concept and the results of quasi-static and fatigue tensile investigations of single lap shear specimens are exposed and discussed. Improvements in ultimate static load, maximum joint deformation, damage tolerance and fatigue life are encountered when comparing the performance of the RHEA lap shear joints to co-bonded reference specimens.

  8. Xenopus LAP2β protein knockdown affects location of lamin B and nucleoporins and has effect on assembly of cell nucleus and cell viability.

    PubMed

    Dubińska-Magiera, Magda; Chmielewska, Magdalena; Kozioł, Katarzyna; Machowska, Magdalena; Hutchison, Christopher J; Goldberg, Martin W; Rzepecki, Ryszard

    2016-05-01

    Xenopus LAP2β protein is the single isoform expressed in XTC cells. The protein localizes on heterochromatin clusters both at the nuclear envelope and inside a cell nucleus. The majority of XLAP2β fraction neither colocalizes with TPX2 protein during interphase nor can be immunoprecipitated with XLAP2β antibody. Knockdown of the XLAP2β protein expression in XTC cells by synthetic siRNA and plasmid encoded siRNA resulted in nuclear abnormalities including changes in shape of nuclei, abnormal chromatin structure, loss of nuclear envelope, mislocalization of integral membrane proteins of INM such as lamin B2, mislocalization of nucleoporins, and cell death. Based on timing of cell death, we suggest mechanism associated with nucleus reassembly or with entry into mitosis. This confirms that Xenopus LAP2 protein is essential for the maintenance of cell nucleus integrity and the process of its reassembly after mitosis. PMID:26209045

  9. Ethanol accumulation in drought-stressed conifer seedlings.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study, we investigated the effect of drought-stress on ethanol production and accumulation in tissues of three conifer species (Douglas-fir, ponderosa pine, and lodgepole pine). Significant ethanol accumulation was observed for all three species at severe levels of drought stress (pre-dawn ...

  10. Intra-individual lap time variation of the 400-m walk, an early mobility indicator of executive function decline in high-functioning older adults?

    PubMed

    Tian, Qu; Resnick, Susan M; Ferrucci, Luigi; Studenski, Stephanie A

    2015-12-01

    Higher intra-individual lap time variation (LTV) of the 400-m walk is cross-sectionally associated with poorer attention in older adults. Whether higher LTV predicts decline in executive function and whether the relationship is accounted for by slower walking remain unanswered. The main objective of this study was to examine the relationship between baseline LTV and longitudinal change in executive function. We used data from 347 participants aged 60 years and older (50.7% female) from the Baltimore Longitudinal Study of Aging. Longitudinal assessments of executive function were conducted between 2007 and 2013, including attention (Trails A, Digit Span Forward Test), cognitive flexibility and set shifting (Trails B, Delta TMT: Trials B minus Trials A), visuoperceptual speed (Digit Symbol Substitution Test), and working memory (Digit Span Backward Test). LTV and mean lap time (MLT) were obtained from the 400-m walk test concurrent with the baseline executive function assessment. LTV was computed as variability of lap time across ten 40-m laps based on individual trajectories. A linear mixed-effects model was used to examine LTV in relation to changes in executive function, adjusted for age, sex, education, and MLT. Higher LTV was associated with greater decline in performance on Trails B (β = 4.322, p < 0.001) and delta TMT (β = 4.230, p < 0.001), independent of covariates. Findings remained largely unchanged after further adjustment for MLT. LTV was not associated with changes in other executive function measures (all p > 0.05). In high-functioning older adults, higher LTV in the 400-m walk predicts executive function decline involving cognitive flexibility and set shifting over a long period of time. High LTV may be an early indicator of executive function decline independent of MLT. PMID:26561401

  11. The Fundamentals of Laparoscopic Surgery and LapVR evaluation metrics may not correlate with operative performance in a novice cohort

    PubMed Central

    Steigerwald, Sarah N.; Park, Jason; Hardy, Krista M.; Gillman, Lawrence; Vergis, Ashley S.

    2015-01-01

    Background Considerable resources have been invested in both low- and high-fidelity simulators in surgical training. The purpose of this study was to investigate if the Fundamentals of Laparoscopic Surgery (FLS, low-fidelity box trainer) and LapVR (high-fidelity virtual reality) training systems correlate with operative performance on the Global Operative Assessment of Laparoscopic Skills (GOALS) global rating scale using a porcine cholecystectomy model in a novice surgical group with minimal laparoscopic experience. Methods Fourteen postgraduate year 1 surgical residents with minimal laparoscopic experience performed tasks from the FLS program and the LapVR simulator as well as a live porcine laparoscopic cholecystectomy. Performance was evaluated using standardized FLS metrics, automatic computer evaluations, and a validated global rating scale. Results Overall, FLS score did not show an association with GOALS global rating scale score on the porcine cholecystectomy. None of the five LapVR task scores were significantly associated with GOALS score on the porcine cholecystectomy. Conclusions Neither the low-fidelity box trainer or the high-fidelity virtual simulator demonstrated significant correlation with GOALS operative scores. These findings offer caution against the use of these modalities for brief assessments of novice surgical trainees, especially for predictive or selection purposes. PMID:26641071

  12. Coordinated Analysis of Two Graphite Grains from the CO3.0 LAP 031117 Meteorite: First Identification of a CO Nova Graphite and a Presolar Iron Sulfide Subgrain

    NASA Astrophysics Data System (ADS)

    Haenecour, Pierre; Floss, Christine; José, Jordi; Amari, Sachiko; Lodders, Katharina; Jadhav, Manavi; Wang, Alian; Gyngard, Frank

    2016-07-01

    Presolar grains constitute the remnants of stars that existed before the formation of the solar system. In addition to providing direct information on the materials from which the solar system formed, these grains provide ground-truth information for models of stellar evolution and nucleosynthesis. Here we report the in situ identification of two unique presolar graphite grains from the primitive meteorite LaPaz Icefield 031117. Based on these two graphite grains, we estimate a bulk presolar graphite abundance of {5}-3+7 ppm in this meteorite. One of the grains (LAP-141) is characterized by an enrichment in 12C and depletions in 33,34S, and contains a small iron sulfide subgrain, representing the first unambiguous identification of presolar iron sulfide. The other grain (LAP-149) is extremely 13C-rich and 15N-poor, with one of the lowest 12C/13C ratios observed among presolar grains. Comparison of its isotopic compositions with new stellar nucleosynthesis and dust condensation models indicates an origin in the ejecta of a low-mass CO nova. Grain LAP-149 is the first putative nova grain that quantitatively best matches nova model predictions, providing the first strong evidence for graphite condensation in nova ejecta. Our discovery confirms that CO nova graphite and presolar iron sulfide contributed to the original building blocks of the solar system.

  13. Path-dependent economic evolution with capital accumulation and education.

    PubMed

    Zhang, Wei-Bin

    2005-07-01

    This paper proposes a dynamic economic model with wealth accumulation and human capital accumulation. The economic system consists of one production sector and one university. The university carries out education. The model describes a dynamic interdependence between wealth accumulation, human capital accumulation, and division of labor under perfect economic competition and the government intervention in education. We provide conditions for the existence of equilibrium points and stability of the nonlinear dynamic system. The simulation results demonstrate path-dependent processes of the nonlinear evolution. Some insights into East Asia's industrializing processes are provided. PMID:16011826

  14. Influence of Zn Interlayer on Interfacial Microstructure and Mechanical Properties of TIG Lap-Welded Mg/Al Joints

    NASA Astrophysics Data System (ADS)

    Gao, Qiong; Wang, Kehong

    2016-03-01

    This study explored 6061 Al alloy and AZ31B Mg alloy joined by TIG lap welding with Zn foils of varying thicknesses, with the additional Zn element being imported into the fusion zone to alloy the weld seam. The microstructures and chemical composition in the fusion zone near the Mg substrate were examined by SEM and EDS, and tensile shear strength tests were conducted to investigate the mechanical properties of the Al/Mg joints, as well as the fracture surfaces, and phase compositions. The results revealed that the introduction of an appropriate amount of Zn transition layer improves the microstructure of Mg/Al joints and effectively reduces the formation of Mg-Al intermetallic compounds (IMCs). The most common IMCs in the fusion zone near the Mg substrate were Mg-Zn and Mg-Al-Zn IMCs. The type and distribution of IMCs generated in the weld zone differed according to Zn additions; Zn interlayer thickness of 0.4 mm improved the sample's mechanical properties considerably compared to thicknesses of less than 0.4 mm; however, any further increase in Zn interlayer thickness of above 0.4 mm caused mechanical properties to deteriorate.

  15. Application of a simple and cost-effective method for detection of bolt self-loosening in single lap joints

    NASA Astrophysics Data System (ADS)

    Esmaeel, Ramadan A.; Taheri, Farid

    2013-09-01

    One of the major advantages of bolted joints (BJs) over welded, riveted and adhesively bonded joints is the disassembling option. This option facilitates the manufacturing and transportation of large-scale structures that are commonly formed as assemblage of various large structural components. However, this option is not always problem free, in that, during the life cycle of such structures, the bolts used to fasten the joints may become loosened. Although several techniques have been developed to mitigate bolt self-loosening (BSL), nonetheless, development of a methodology for detecting BSL has consumed considerable attention in recent years. As a result, several researchers have been seeking simple and reliable methods for detecting bolt-loosening in BJs, without compromising their stability. In this study, piezoelectric sensors are used to collect the vibration signals of a laboratory-scale single lap joint, joining two steel plates with three bolts. The acquired signals are then processed using the empirical mode decomposition method and the energies of the respective signals are calculated. A recently developed effective method is then employed to establish the so-called energy damage index, evaluated based on the energy stored in certain modes of the collected signal, in both the damaged and healthy states of the system. This method is found to be quite effective in detecting bolt loosening and the progression of self-loosening.

  16. Biomimetic-inspired joining of composite with metal structures: A survey of natural joints and application to single lap joints

    NASA Astrophysics Data System (ADS)

    Avgoulas, Evangelos Ioannis; Sutcliffe, Michael P. F.

    2014-03-01

    Joining composites with metal parts leads, inevitably, to high stress concentrations because of the material property mismatch. Since joining composite to metal is required in many high performance structures, there is a need to develop a new multifunctional approach to meet this challenge. This paper uses the biomimetics approach to help develop solutions to this problem. Nature has found many ingenious ways of joining dissimilar materials and making robust attachments, alleviating potential stress concentrations. A literature survey of natural joint systems has been carried out, identifying and analysing different natural joint methods from a mechanical perspective. A taxonomy table was developed based on the different methods/functions that nature successfully uses to attach dissimilar tissues (materials). This table is used to understand common themes or approaches used in nature for different joint configurations and functionalities. One of the key characteristics that nature uses to joint dissimilar materials is a transitional zone of stiffness in the insertion site. Several biomimetic-inspired metal-to-composite (steel-to-CFRP), adhesively bonded, Single Lap Joints (SLJs) were numerically investigated using a finite element analysis. The proposed solutions offer a transitional zone of stiffness of one joint part to reduce the material stiffness mismatch at the joint. An optimisation procedure was used to identify the variation in material stiffness which minimises potential failure of the joint. It was found that the proposed biomimetic SLJs reduce the asymmetry of the stress distribution along the adhesive area.

  17. Laser damage initiation and growth of antireflection coated S-FAP crystal surfaces prepared by pitch lap and magnetorheological finishing

    SciTech Connect

    Stolz, C J; Menapace, J A; Schaffers, K I; Bibeau, C; Thomas, M D; Griffin, A J

    2005-10-31

    Antireflection (AR) coatings typically damage at the interface between the substrate and coating. Therefore the substrate finishing technology can have an impact on the laser resistance of the coating. For this study, AR coatings were deposited on Yb:S-FAP [Yb{sup 3+}:Sr{sub 5}(PO{sub 4}){sub 3}F] crystals that received a final polish by both conventional pitch lap finishing as well as magnetorheological finishing (MRF). SEM images of the damage morphology reveals laser damage originates at scratches and at substrate coating interfacial absorbing defects. Previous damage stability tests on multilayer mirror coatings and bare surfaces revealed damage growth can occur at fluences below the initiation fluence. The results from this study suggest the opposite trend for AR coatings. Investigation of unstable HR and uncoated surface damage morphologies reveals significant radial cracking that is not apparent with AR damage due to AR delamination from the coated surface with few apparent cracks at the damage boundary. Damage stability tests show that coated Yb:S-FAP crystals can operate at 1057 nm at fluences around 20 J/cm{sup 2} at 10 ns; almost twice the initiation damage threshold.

  18. LigLAP: Encirclement and Ligation of Vessels in Laparoscopic Surgery: A Double-Layer Suture Sealing Approach.

    PubMed

    Yousefian, Reza; Jones, Paul; Kia, Michael A; Zadeh, Mehrdad Hosseini

    2015-12-01

    This article proposes a potential automatic ligation (LigLAP) method to occlude vessels and ducts in several laparoscopic surgical procedures. Currently, stapling devices are widely used for this purpose. However, there are some complications associated with stapling devices, including biliary leak and tissue damage. In this article, we examine the feasibility of an alternative method that uses a double-layer suture to encircle and occlude a vessel. A heating element melts the outer layer of the suture at the cross-point of the suture to create a seal. Several electromechanical mechanisms have been proposed to carry out this ligation process. In addition, some parts have been prototyped for experimental verification and visualization. Several double-layered sutures have been created, and their tensile strength and sealing capabilities have been measured. Moreover, a simple leakage experiment has been performed to verify experimentally the idea of using the double-layer suture. The results show that the new suture and the thermal sealing method provide the required strength to occlude balloons filled with water. Although the results suggest that the proposed method and the double-layer suture may be used in surgical ligation processes, much more rigorous testing of leakage is required. PMID:25918125

  19. Nd:Yag laser irradiation of single lap joints made by polyethylene and polyethylene doped by carbon nanomaterials

    NASA Astrophysics Data System (ADS)

    Visco, A. M.; Brancato, V.; Cutroneo, M.; Torrisi, L.

    2014-04-01

    Thermoplastic polyethylene can be welded by the transmission laser welding technique (TTLW) that exhibits some process related benefits with respect other conventional joining methods. This justifies its large use in wide fields, from the automotive to medical or domestic appliances. In this research, we studied single lap joints made by polyethylene pure and filled with carbon nanomaterials (0.2% in weight) to make the polymer laser absorbent. The joints were irradiated by a Nd:YAG laser operating at 1064 nm (first harmonic) with an intensity of 107 W/cm2 and 1 ÷ 30Hz, a maximum pulse energy of 300mJ and a laser spot of ≈ 1 cm2 (no focusing lens were employed). The joints were characterized by morphological analysis, mechanical shear tests and calorimetric analysis. The results suggested that the laser exposition time must be opportunely balanced in order to avoid a poor adhesion between the polymer sheets and to realized efficient joints. In particular the mechanical test showed that the laser exposition time of 40 seconds is the best conditions to obtain the highest shear strength of the joints of 140 N. After too prolonged laser exposure times, degrading phenomena starts.

  20. Establishment of a model predicting tensile shear strength and fracture portion of laser-welded lap joints

    NASA Astrophysics Data System (ADS)

    Furusako, Seiji; Miyazaki, Yasunobu; Hashimoto, Koji; Kobayashi, Junichi

    2003-03-01

    This study was aimed at establishment of a model that can predict tensile shear strength and fracture portion laser-welded lap joints in the tensile test. To clear influence of the bead length and width on them, the joints employed steel sheets with a thickness in the range of 0.8 mm to 1.2 mm were evaluated. It was found that the tensile shear strength increased with the bead size, and the fracture occurred at base metal (BM), weld metal (WM) or portion between them with a curvature (referred to as portion R). Also to clarify rotational deformation process around WM during the tensile test, joint cross-sections were observed at some applied load levels in the test. This observation derived the relationship between the radius, Ri, at the inner plane of portion R and the rotational angle, θ, of the center of sheet thickness, and the relationship between Ri and applied load. A plastic analysis based on these functions and assumptions that the joint consists of BM, WM and R, which are under simplified stress mode respectively, could estimate the tensile shear strength and the fracture portion of the joints. This estimation made good accord with experimental results.

  1. Mechanical Behavior of Lithium-Ion Batteries and Fatigue Behavior of Ultrasonic Weld-Bonded Lap-Shear Specimens of Dissimilar Magnesium and Steel Sheets

    NASA Astrophysics Data System (ADS)

    Lai, Wei-Jen

    The mechanical behaviors of LiFePO4 battery cell and module specimens under in-plane constrained compression were investigated for simulations of battery cells, modules and packs under crush conditions. The experimental stress-strain curves were correlated to the deformation patterns of battery cell and module specimens. Analytical solutions were developed to estimate the buckling stresses and to provide a theoretical basis for future design of representative volume element cell and module specimens. A physical kinematics model for formation of kinks and shear bands in battery cells was developed to explain the deformation mechanism for layered battery cells under in-plane constrained compression. A small-scale module constrained punch indentation test was also conducted to benchmark the computational results. The computational results indicate that macro homogenized material models can be used to simulate battery modules under crush conditions. Fatigue behavior and failure modes of ultrasonic spot welds in lap-shear specimens of magnesium and steel sheets with and without adhesive were investigated. For ultrasonic spot welded lap-shear specimens, the failure mode changes from the partial nugget pullout mode under low-cycle loading conditions to the kinked crack failure mode under high-cycle loading conditions. For adhesive-bonded and weld-bonded lap-shear specimens, the test results show the near interface cohesive failure mode and the kinked crack failure mode under low-cycle and high-cycle loading conditions, respectively. Next, the analytical effective stress intensity factor solutions for main cracks in lap-shear specimens of three dissimilar sheets under plane strain conditions were developed and the solutions agreed well with the computational results. The analytical effective stress intensity factor solutions for kinked cracks were compared with the computational results at small kink lengths. The results indicate that the computational results approach to

  2. Noise Reduction by Signal Accumulation

    ERIC Educational Resources Information Center

    Kraftmakher, Yaakov

    2006-01-01

    The aim of this paper is to show how the noise reduction by signal accumulation can be accomplished with a data acquisition system. This topic can be used for student projects. In many cases, the noise reduction is an unavoidable part of experimentation. Several techniques are known for this purpose, and among them the signal accumulation is the…

  3. MODELING LONG-TERM DYNAMICS OF LITTER ACCUMULATION IN RESPONSE TO STATIC AND VARIABLE HYDROPERIODS

    EPA Science Inventory

    Accumulated litter from emergent species like the cattail hybrid (Typha glauca Godr.) can influence local abiotic conditions, other biota, and ecosystem processes. Litter accumulation results from high production coupled with slow breakdown rates. Wetland managers regularly mani...

  4. LC-PUFA-Enriched Oil Production by Microalgae: Accumulation of Lipid and Triacylglycerols Containing n-3 LC-PUFA Is Triggered by Nitrogen Limitation and Inorganic Carbon Availability in the Marine Haptophyte Pavlova lutheri

    PubMed Central

    Guihéneuf, Freddy; Stengel, Dagmar B.

    2013-01-01

    In most microalgal species, triacyglycerols (TAG) contain mostly saturated and monounsaturated fatty acids, rather than PUFA, while PUFA-enriched oil is the form most desirable for dietary intake. The ability of some species to produce LC-PUFA-enriched oil is currently of specific interest. In this work, we investigated the role of sodium bicarbonate availability on lipid accumulation and n-3 LC-PUFA partitioning into TAG during batch cultivation of Pavlova lutheri. Maximum growth and nitrate uptake exhibit an optimum concentration and threshold tolerance to bicarbonate addition (~9 mM) above which both parameters decreased. Nonetheless, the transient highest cellular lipid and TAG contents were obtained at 18 mM bicarbonate, immediately after combined alkaline pH stress and nitrate depletion (day nine), while oil body and TAG accumulation were highly repressed with low carbon supply (2 mM). Despite decreases in the proportions of EPA and DHA, maximum volumetric and cellular EPA and DHA contents were obtained at this stage due to accumulation of TAG containing EPA/DHA. TAG accounted for 74% of the total fatty acid per cell, containing 55% and 67% of the overall cellular EPA and DHA contents, respectively. These results clearly demonstrate that inorganic carbon availability and elevated pH represent two limiting factors for lipid and TAG accumulation, as well as n-3 LC-PUFA partitioning into TAG, under nutrient-depleted P. lutheri cultures. PMID:24177672

  5. Gypsum accumulation on carbonate stone

    USGS Publications Warehouse

    McGee, E.S.; Mossotti, V.G.

    1992-01-01

    The accumulation of gypsum on carbonate stone has been investigated through exposure of fresh samples of limestone and marble at monitored sites, through examination of alteration crusts from old buildings and through laboratory experiments. Several factors contribute to gypsum accumulation on carbonate stone. Marble or limestone that is sheltered from direct washing by rain in an urban environment with elevated pollution levels is likely to accumulate a gypsum crust. Crust development may be enhanced if the stone is porous or has an irregular surface area. Gypsum crusts are a surficial alteration feature; gypsum crystals form at the pore opening-air interface, where evaporation is greatest.

  6. Selective expression of latency-associated peptide (LAP) and IL-1 receptor type I/II (CD121a/CD121b) on activated human FOXP3+ regulatory T cells allows for their purification from expansion cultures

    PubMed Central

    Andersson, John; Hardwick, Donna; Bebris, Lolita; Illei, Gabor G.

    2009-01-01

    Although adoptive transfer of regulatory T cells (Foxp3+ Tregs) has proven to be efficacious in the prevention and treatment of autoimmune diseases and graft-versus-host disease in rodents, a major obstacle for the use of Treg immunotherapy in humans is the difficulty of obtaining a highly purified preparation after ex vivo expansion. We have identified latency-associated peptide (LAP) and IL-1 receptor type I and II (CD121a/CD121b) as unique cell-surface markers that distinguish activated Tregs from activated FOXP3− and FOXP3+ non-Tregs. We show that it is feasible to sort expanded FOXP3+ Tregs from non-Tregs with the use of techniques for magnetic bead cell separation based on expression of these 3 markers. After separation, the final product contains greater than 90% fully functional FOXP3+ Tregs. This novel protocol should facilitate the purification of Tregs for both cell-based therapies as well as detailed studies of human Treg function in health and disease. PMID:19299332

  7. Manganese As a Metal Accumulator

    EPA Science Inventory

    Manganese deposits in water distribution systems accumulate metals, radionuclides and oxyanions by a combination of surface complexation, adsorption and solid substitution, as well as a combination of oxidation followed by manganese reduction and sorption of the oxidized constitu...

  8. Evidence accumulation for spatial reasoning

    NASA Technical Reports Server (NTRS)

    Matsuyama, T.; Hwang, V. S. S.; Davis, L. S.

    1984-01-01

    The evidence accumulation proces of an image understanding system is described enabling the system to perform top-down(goal-oriented) picture processing as well as bottom-up verification of consistent spatial relations among objects.

  9. Clinical issues of mucus accumulation in COPD

    PubMed Central

    Ramos, Frederick L; Krahnke, Jason S; Kim, Victor

    2014-01-01

    Airway mucus is part of the lung’s native immune function that traps particulates and microorganisms, enabling their clearance from the lung by ciliary transport and cough. Mucus hypersecretion and chronic productive cough are the features of the chronic bronchitis and chronic obstructive pulmonary disease (COPD). Overproduction and hypersecretion by goblet cells and the decreased elimination of mucus are the primary mechanisms responsible for excessive mucus in chronic bronchitis. Mucus accumulation in COPD patients affects several important outcomes such as lung function, health-related quality of life, COPD exacerbations, hospitalizations, and mortality. Nonpharmacologic options for the treatment of mucus accumulation in COPD are smoking cessation and physical measures used to promote mucus clearance. Pharmacologic therapies include expectorants, mucolytics, methylxanthines, beta-adrenergic receptor agonists, anticholinergics, glucocorticoids, phosphodiesterase-4 inhibitors, antioxidants, and antibiotics. PMID:24493923

  10. Carbon allocation and accumulation in conifers

    SciTech Connect

    Gower, S.T.; Isebrands, J.G.; Sheriff, D.W.

    1995-07-01

    Forests cover approximately 33% of the land surface of the earth, yet they are responsible for 65% of the annual carbon (C) accumulated by all terrestrial biomes. In general, total C content and net primary production rates are greater for forests than for other biomes, but C budgets differ greatly among forests. Despite several decades of research on forest C budgets, there is still an incomplete understanding of the factors controlling C allocation. Yet, if we are to understand how changing global events such as land use, climate change, atmospheric N deposition, ozone, and elevated atmospheric CO{sub 2} affect the global C budget, a mechanistic understanding of C assimilation, partitioning, and allocation is necessary. The objective of this chapter is to review the major factors that influence C allocation and accumulation in conifer trees and forests. In keeping with the theme of this book, we will focus primarily on evergreen conifers. However, even among evergreen conifers, leaf, canopy, and stand-level C and nutrient allocation patterns differ, often as a function of leaf development and longevity. The terminology related to C allocation literature is often inconsistent, confusing and inadequate for understanding and integrating past and current research. For example, terms often used synonymously to describe C flow or movement include translocation, transport, distribution, allocation, partitioning, apportionment, and biomass allocation. A common terminology is needed because different terms have different meanings to readers. In this paper we use C allocation, partitioning, and accumulation according to the definitions of Dickson and Isebrands (1993). Partitioning is the process of C flow into and among different chemical, storage, and transport pools. Allocation is the distribution of C to different plant parts within the plant (i.e., source to sink). Accumulation is the end product of the process of C allocation.

  11. Initiation and growth of multiple-site damage in the riveted lap joint of a curved stiffened fuselage panel: An experimental and analytical study

    NASA Astrophysics Data System (ADS)

    Ahmed, Abubaker Ali

    As part of the structural integrity research of the National Aging Aircraft Research Program, a comprehensive study on multiple-site damage (MSD) initiation and growth in a pristine lap-joint fuselage panel has been conducted. The curved stiffened fuselage panel was tested at the Full-Scale Aircraft Structural Test Evaluation and Research (FASTER) facility located at the Federal Aviation Administration William J. Hughes Technical Center. A strain survey test was conducted to verify proper load application. The panel was then subjected to a fatigue test with constant-amplitude cyclic loading. The applied loading spectrum included underload marker cycles so that crack growth history could be reconstructed from post-test fractographic examinations. Crack formation and growth were monitored via nondestructive and high-magnification visual inspections. Strain gage measurements recorded during the strain survey tests indicated that the inner surface of the skin along the upper rivet row of the lap joint experienced high tensile stresses due to local bending. During the fatigue loading, cracks were detected by eddy-current inspections at multiple rivet holes along the upper rivet row. Through-thickness cracks were detected visually after about 80% of the fatigue life. Once MSD cracks from two adjacent rivet holes linked up, there was a quick deterioration in the structural integrity of the lap joint. The linkup resulted in a 2.87" (72.9-mm) lead fatigue crack that rapidly propagated across 12 rivet holes and crossed over into the next skin bay, at which stage the fatigue test was terminated. A post-fatigue residual strength test was then conducted by loading the panel quasi-statically up to final failure. The panel failed catastrophically when the crack extended instantaneously across three additional bays. Post-test fractographic examinations of the fracture surfaces in the lap joint of the fuselage panel were conducted to characterize subsurface crack initiation and

  12. Effects of Fusion Zone Size and Failure Mode on Peak Load and Energy Absorption of Advanced High Strength Steel Spot Welds under Lap Shear Loading Conditions

    SciTech Connect

    Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2008-06-01

    This paper examines the effects of fusion zone size on failure modes, static strength and energy absorption of resistance spot welds (RSW) of advanced high strength steels (AHSS) under lap shear loading condition. DP800 and TRIP800 spot welds are considered. The main failure modes for spot welds are nugget pullout and interfacial fracture. Partial interfacial fracture is also observed. Static weld strength tests using lap shear samples were performed on the joint populations with various fusion zone sizes. The resulted peak load and energy absorption levels associated with each failure mode were studied for all the weld populations using statistical data analysis tools. The results in this study show that AHSS spot welds with conventionally required fusion zone size of can not produce nugget pullout mode for both the DP800 and TRIP800 welds under lap shear loading. Moreover, failure mode has strong influence on weld peak load and energy absorption for all the DP800 welds and the TRIP800 small welds: welds failed in pullout mode have statistically higher strength and energy absorption than those failed in interfacial fracture mode. For TRIP800 welds above the critical fusion zone level, the influence of weld failure modes on peak load and energy absorption diminishes. Scatter plots of peak load and energy absorption versus weld fusion zone size were then constructed, and the results indicate that fusion zone size is the most critical factor in weld quality in terms of peak load and energy absorption for both DP800 and TRIP800 spot welds.

  13. Design and Engineering Aspects of a Compact Lyman Alpha Photometer (LAP) for In-situ Measurements of D/H Ratio in Martian Atmosphere

    NASA Astrophysics Data System (ADS)

    Sridhar Raja, V. L. N.; Kalyani, K.; Mohan, Aparna; Chandran, Anand; Durga Pushpavalli, J. T.; Laxmiprasad, S. A.; Kamalakar, A. J.; Viswanathan, M.; Rao, M. V. H.

    2012-07-01

    One of the most challenging multidisciplinary problems in geophysics and atmospheric science is the study of the evolution and escape of planetary atmospheres. Owing to no or little intrinsic magnetic field, the upper atmosphere of the planet Mars is always exposed to the solar wind that triggers the photo-dissociation of water by producing H and D, which are subsequently lost to space over time. Measurements of the atmospheric deuterium to hydrogen abundance ratio (D/H ratio) are significantly vital not only to examine the escape process of the current atmosphere but also to infer the loss process of water in the evolutionary history of Martian atmosphere. Till date, observations of D/H ratio measurements of Mars revealed only local values at certain time or average values over the planetary atmosphere. The exact value of the pristine Martian D/H ratio is still considered to be an open question. This paper primarily focuses on the development of a compact ultraviolet photometer capable of providing present D/H ratio of Mars from spacecraft observations. An ultraviolet photometer named `Lyman Alpha Photometer-LAP' that is currently under development at our laboratory is compact, light weight with low-power consumption and supports the spacecraft operational altitude range of 200 km to 20000 km. LAP operates on the principle of resonant scattering and absorption at Lyman-a wavelengths of H and D i.e., 121.56 nm, 121.53 nm respectively and comprises of 25 mm (Φ) x 60 mm (l) cylindrical metal/glass based gas cells filled with pure H2 and D2 gases at 3 mbar pressure. Thermally dissociated H2 and D2 molecules (due to the heating of a filament inserted in the cell) in the cells absorb the incoming H2/D2 Lyman-a incident on the cell. A 15 nm bandwidth Lyman-a filter cuts-off the undesirable radiation and a solar-blind side-on type photo multiplier tube (PMT) is selected for photon detection. Proto-LAP that is currently under development is a compact instrument that

  14. Flavonoid accumulation patterns of transparent testa mutants of arabidopsis

    NASA Technical Reports Server (NTRS)

    Peer, W. A.; Brown, D. E.; Tague, B. W.; Muday, G. K.; Taiz, L.; Murphy, A. S.

    2001-01-01

    Flavonoids have been implicated in the regulation of auxin movements in Arabidopsis. To understand when and where flavonoids may be acting to control auxin movement, the flavonoid accumulation pattern was examined in young seedlings and mature tissues of wild-type Arabidopsis. Using a variety of biochemical and visualization techniques, flavonoid accumulation in mature plants was localized in cauline leaves, pollen, stigmata, and floral primordia, and in the stems of young, actively growing inflorescences. In young Landsberg erecta seedlings, aglycone flavonols accumulated developmentally in three regions, the cotyledonary node, the hypocotyl-root transition zone, and the root tip. Aglycone flavonols accumulated at the hypocotyl-root transition zone in a developmental and tissue-specific manner with kaempferol in the epidermis and quercetin in the cortex. Quercetin localized subcellularly in the nuclear region, plasma membrane, and endomembrane system, whereas kaempferol localized in the nuclear region and plasma membrane. The flavonoid accumulation pattern was also examined in transparent testa mutants blocked at different steps in the flavonoid biosynthesis pathway. The transparent testa mutants were shown to have precursor accumulation patterns similar to those of end product flavonoids in wild-type Landsberg erecta, suggesting that synthesis and end product accumulation occur in the same cells.

  15. Flavonoid Accumulation Patterns of Transparent Testa Mutants of Arabidopsis1

    PubMed Central

    Peer, Wendy Ann; Brown, Dana E.; Tague, Brian W.; Muday, Gloria K.; Taiz, Lincoln; Murphy, Angus S.

    2001-01-01

    Flavonoids have been implicated in the regulation of auxin movements in Arabidopsis. To understand when and where flavonoids may be acting to control auxin movement, the flavonoid accumulation pattern was examined in young seedlings and mature tissues of wild-type Arabidopsis. Using a variety of biochemical and visualization techniques, flavonoid accumulation in mature plants was localized in cauline leaves, pollen, stigmata, and floral primordia, and in the stems of young, actively growing inflorescences. In young Landsberg erecta seedlings, aglycone flavonols accumulated developmentally in three regions, the cotyledonary node, the hypocotyl-root transition zone, and the root tip. Aglycone flavonols accumulated at the hypocotyl-root transition zone in a developmental and tissue-specific manner with kaempferol in the epidermis and quercetin in the cortex. Quercetin localized subcellularly in the nuclear region, plasma membrane, and endomembrane system, whereas kaempferol localized in the nuclear region and plasma membrane. The flavonoid accumulation pattern was also examined in transparent testa mutants blocked at different steps in the flavonoid biosynthesis pathway. The transparent testa mutants were shown to have precursor accumulation patterns similar to those of end product flavonoids in wild-type Landsberg erecta, suggesting that synthesis and end product accumulation occur in the same cells. PMID:11402185

  16. Inactivation of the inhA-encoded fatty acid synthase II (FASII) enoyl-acyl carrier protein reductase induces accumulation of the FASI end products and cell lysis of Mycobacterium smegmatis.

    PubMed

    Vilchèze, C; Morbidoni, H R; Weisbrod, T R; Iwamoto, H; Kuo, M; Sacchettini, J C; Jacobs, W R

    2000-07-01

    The mechanism of action of isoniazid (INH), a first-line antituberculosis drug, is complex, as mutations in at least five different genes (katG, inhA, ahpC, kasA, and ndh) have been found to correlate with isoniazid resistance. Despite this complexity, a preponderance of evidence implicates inhA, which codes for an enoyl-acyl carrier protein reductase of the fatty acid synthase II (FASII), as the primary target of INH. However, INH treatment of Mycobacterium tuberculosis causes the accumulation of hexacosanoic acid (C(26:0)), a result unexpected for the blocking of an enoyl-reductase. To test whether inactivation of InhA is identical to INH treatment of mycobacteria, we isolated a temperature-sensitive mutation in the inhA gene of Mycobacterium smegmatis that rendered InhA inactive at 42 degrees C. Thermal inactivation of InhA in M. smegmatis resulted in the inhibition of mycolic acid biosynthesis, a decrease in hexadecanoic acid (C(16:0)) and a concomitant increase of tetracosanoic acid (C(24:0)) in a manner equivalent to that seen in INH-treated cells. Similarly, INH treatment of Mycobacterium bovis BCG caused an inhibition of mycolic acid biosynthesis, a decrease in C(16:0), and a concomitant accumulation of C(26:0). Moreover, the InhA-inactivated cells, like INH-treated cells, underwent a drastic morphological change, leading to cell lysis. These data show that InhA inactivation, alone, is sufficient to induce the accumulation of saturated fatty acids, cell wall alterations, and cell lysis and are consistent with InhA being a primary target of INH. PMID:10869086

  17. Anthocyanins facilitate tungsten accumulation in Brassica

    SciTech Connect

    Hale, K.L.

    2002-11-01

    Accumulation of molybdenum in Brassica was recently found to be correlated with anthocyanin content, involving the formation of a blue complex. Here the role of anthocyanins in tungsten sequestration was investigated using three species of Brassica: B. rapa (cv. Fast plants), B. juncea (Indian mustard) and B. oleracea (red cabbage). Seedlings of B. rapa and B. juncea turned blue when supplied with colourless tungstate. The blue compound co-localized with anthocyanins in the peripheral cell layers, and the degree of blueness was correlated with anthocyanin content. The direct involvement of anthocyanins in the blue coloration was evident when purified anthocyanins showed a colour change from pink to blue in vitro upon addition of tungstate, over a wide pH range. Anthocyanin production was upregulated 3-fold by W in B. juncea, possibly reflecting a function for anthocyanins in W tolerance or sequestration. The presence of anthocyanins facilitated W accumulation in B. rapa: anthocyanin-containing seedlings accumulated 3-fold more W than an anthocyaninless mutant. There was no correlation between anthocyanin content and W tolerance under these conditions. The nature of the interaction between anthocyanins and tungstate was investigated. X-ray absorption spectroscopy showed no change in the local chemical environment of Wupon uptake of tungstate by the plant; HPLC analysis of purified anthocyanin with or without tungstate showed no peak shift after metal treatment.

  18. Maximum likelihood decoding analysis of Accumulate-Repeat-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    Repeat-Accumulate (RA) codes are the simplest turbo-like codes that achieve good performance. However, they cannot compete with Turbo codes or low-density parity check codes (LDPC) as far as performance is concerned. The Accumulate Repeat Accumulate (ARA) codes, as a subclass of LDPC codes, are obtained by adding a pre-coder in front of RA codes with puncturing where an accumulator is chosen as a precoder. These codes not only are very simple, but also achieve excellent performance with iterative decoding. In this paper, the performance of these codes with (ML) decoding are analyzed and compared to random codes by very tight bounds. The weight distribution of some simple ARA codes is obtained, and through existing tightest bounds we have shown the ML SNR threshold of ARA codes approaches very closely to the performance of random codes. We have shown that the use of precoder improves the SNR threshold but interleaving gain remains unchanged with respect to RA code with puncturing.

  19. Regulation of Monoterpene Accumulation in Leaves of Peppermint1

    PubMed Central

    Gershenzon, Jonathan; McConkey, Marie E.; Croteau, Rodney B.

    2000-01-01

    Plants synthesize numerous classes of natural products that accumulate during development and are thought to function as constitutive defenses against herbivores and pathogens. However, little information is available about how the levels of such defenses are regulated. We measured the accumulation of monoterpenes, a model group of constitutive defenses, in peppermint (Mentha × piperita L.) leaves and investigated several physiological processes that could regulate their accumulation: the rate of biosynthesis, the rate of metabolic loss, and the rate of volatilization. Monoterpene accumulation was found to be restricted to leaves of 12 to 20 d of age, the period of maximal leaf expansion. The rate of monoterpene biosynthesis determined by 14CO2 incorporation was closely correlated with monoterpene accumulation, as determined by gas chromatographic analysis, and appeared to be the principal factor controlling the monoterpene level of peppermint leaves. No significant catabolic losses of monoterpenes were detected throughout leaf development, and monoterpene volatilization was found to occur at a very low rate, which, on a monthly basis, represented less than 1% of the total pool of stored monoterpenes. The composition of volatilized monoterpenes differed significantly from that of the total plant monoterpene pool, suggesting that these volatilized products may arise from a separate secretory system. With the demonstration that the rate of biosynthesis is the chief process that determines monoterpene accumulation in peppermint, efforts to improve production in this species can now focus on the genes, enzymes, and cell differentiation processes that regulate monoterpene biosynthesis. PMID:10631264

  20. Measurement of longitudinal strain and estimation of peel stress in adhesive-bonded single-lap joint of CFRP adherend using embedded FBG sensor

    NASA Astrophysics Data System (ADS)

    Ning, X.; Murayama, H.; Kageyama, K.; Uzawa, K.; Wada, D.

    2012-04-01

    In this research, longitudinal strain and peel stress in adhesive-bonded single-lap joint of carbon fiber reinforced plastics (CFRP) were measured and estimated by embedded fiber Bragg grating (FBG) sensor. Two unidirectional CFRP substrates were bonded by epoxy to form a single-lap configuration. The distributed strain measurement system is used. It is based on optical frequency domain reflectometry (OFDR), which can provide measurement at an arbitrary position along FBG sensors with the high spatial resolution. The longitudinal strain was measured based on Bragg grating effect and the peel stress was estimated based on birefringence effect. Special manufacturing procedure was developed to ensure the embedded location of FBG sensor. A portion of the FBG sensor was embedded into one of CFRP adherends along fiber direction and another portion was kept free for temperature compensation. Photomicrograph of cross-section of specimen was taken to verify the sensor was embedded into proper location after adherend curing. The residual strain was monitored during specimen curing and adhesive joint bonding process. Tensile tests were carried out and longitudinal strain and peel stress of the bondline are measured and estimated by the embedded FBG sensor. A two-dimensional geometrically nonlinear finite element analysis was performed by ANSYS to evaluate the measurement precision.

  1. Assessment of a three-point restraint system with a pre-tensioned lap belt and an inflatable, force-limited shoulder belt.

    PubMed

    Kent, Richard; Lopez-Valdes, Francisco J; Dennis, Nate J; Lessley, David; Forman, Jason; Higuchi, Kazuo; Tanji, Hiromasa; Ato, Tadayuki; Kameyoshi, Hikaru; Arbogast, Kristy

    2011-11-01

    This study investigates the performance of a 3-point restraint system incorporating an inflatable shoulder belt with a nominal 2.5-kN load limiter and a non-inflatable lap belt with a pretensioner (the "Airbelt"). Frontal impacts with PMHS in a rear seat environment are presented and the Airbelt system is contrasted with an earlier 3-point system with inflatable lap and shoulder belts but no load-limiter or pretensioners, which was evaluated with human volunteers in the 1970s but not fully reported in the open literature (the "Inflataband"). Key differences between the systems include downward pelvic motion and torso recline with the Inflataband, while the pelvis moved almost horizontally and the torso pitched forward with the Airbelt. One result of these kinematic differences was an overall more biomechanically favorable restraint loading but greater maximum forward head excursion with the Airbelt. The Airbelt is shown to generate generally lower head, neck, and thoracic injury metrics and PMHS trauma than other, non-inflatable rear-seat restraint concepts (viz., a standard 3-point belt and a pre-tensioned shoulder belt with a progressive load limiter). Further study is needed to evaluate the Airbelt system for different size occupants (e.g., children), non-frontal impact vectors, and for out-of-position occupants and to allow the results with this particular system to be generalized to a broader range of Airbelt designs. PMID:22869308

  2. Ecology: accumulating threats to life

    SciTech Connect

    Peterson, R.W.

    1980-04-01

    The accumulating impacts of toxic materials like polychloridnated bephenyls (PCBs), acid rain, deforestation in the Amazon River Basin, and nuclear energy are examined as life-threatening actions that the public must recognize. Immediate action is needed to abandon destructive human activities and search out those life-supporting choices which will replace immediate gratification with long-range benefits. (DCK)

  3. Pensions and Household Wealth Accumulation

    ERIC Educational Resources Information Center

    Engelhardt, Gary V.; Kumar, Anil

    2011-01-01

    Economists have long suggested that higher private pension benefits "crowd out" other sources of household wealth accumulation. We exploit detailed information on pensions and lifetime earnings for older workers in the 1992 wave of the Health and Retirement Study and employ an instrumental-variable (IV) identification strategy to estimate…

  4. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired... fluid. Accumulators must meet the applicable requirements in § 54.01-5 (c)(3), (c)(4), and (d) of this chapter or the remaining requirements in part 54. (b) If the accumulator is of the gas and fluid...

  5. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired... fluid. Accumulators must meet the applicable requirements in § 54.01-5 (c)(3), (c)(4), and (d) of this chapter or the remaining requirements in part 54. (b) If the accumulator is of the gas and fluid...

  6. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired... fluid. Accumulators must meet the applicable requirements in § 54.01-5 (c)(3), (c)(4), and (d) of this chapter or the remaining requirements in part 54. (b) If the accumulator is of the gas and fluid...

  7. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired... fluid. Accumulators must meet the applicable requirements in § 54.01-5 (c)(3), (c)(4), and (d) of this chapter or the remaining requirements in part 54. (b) If the accumulator is of the gas and fluid...

  8. R-acetoin accumulation and dissimilation in Klebsiella pneumoniae.

    PubMed

    Wang, Dexin; Zhou, Jidong; Chen, Chuan; Wei, Dong; Shi, Jiping; Jiang, Biao; Liu, Pengfu; Hao, Jian

    2015-08-01

    Klebsiella pneumoniae is a 2,3-butanediol producer, and R-acetoin is an intermediate of 2,3-butanediol production. R-acetoin accumulation and dissimilation in K. pneumoniae was studied here. A budC mutant, which has lost 2,3-butanediol dehydrogenase activity, accumulated high levels of R-acetoin in culture broth. However, after glucose was exhausted, the accumulated R-acetoin could be reused by the cells as a carbon source. Acetoin dehydrogenase enzyme system, encoded by acoABCD, was responsible for R-acetoin dissimilation. acoABCD mutants lost the ability to grow on acetoin as the sole carbon source, and the acetoin accumulated could not be dissimilated. However, in the presence of another carbon source, the acetoin accumulated in broth of acoABCD mutants was converted to 2,3-butanediol. Parameters of R-acetoin production by budC mutants were optimized in batch culture. Aerobic culture and mildly acidic conditions (pH 6-6.5) favored R-acetoin accumulation. At the optimized conditions, in fed-batch fermentation, 62.3 g/L R-acetoin was produced by budC and acoABCD double mutant in 57 h culture, with an optical purity of 98.0 %, and a substrate conversion ratio of 28.7 %. PMID:26059458

  9. Accumulation of Poly (beta-Hydroxybutyrate) by Halobacteria.

    PubMed

    Fernandez-Castillo, R; Rodriguez-Valera, F; Gonzalez-Ramos, J; Ruiz-Berraquero, F

    1986-01-01

    Some species of extremely halophilic archaebacteria, Halobacteriaceae, have been shown to accumulate large amounts of poly (beta-hydroxybutyrate) under conditions of nitrogen limitation and abundant carbon source. The production of poly (beta-hydroxybutyrate), at least in large quantities, was restricted to two carbohydrate-utilizing species, Halobacterium mediterranei and H. volcanii. In addition to the nutrients in the media, the salt concentration also influenced poly (beta-hydroxybutyrate) accumulation, which was greater at lower salt concentrations. The possible application of these microorganisms for the production of biodegradable plastics is discussed. PMID:16346972

  10. Triacylglycerol Metabolism, Function, and Accumulation in Plant Vegetative Tissues.

    PubMed

    Xu, Changcheng; Shanklin, John

    2016-04-29

    Oils in the form of triacylglycerols are the most abundant energy-dense storage compounds in eukaryotes, and their metabolism plays a key role in cellular energy balance, lipid homeostasis, growth, and maintenance. Plants accumulate oils primarily in seeds and fruits. Plant oils are used for food and feed and, increasingly, as feedstocks for biodiesel and industrial chemicals. Although plant vegetative tissues do not accumulate significant levels of triacylglycerols, they possess a high capacity for their synthesis, storage, and metabolism. The development of plants that accumulate oil in vegetative tissues presents an opportunity for expanded production of triacylglycerols as a renewable and sustainable bioenergy source. Here, we review recent progress in the understanding of triacylglycerol synthesis, turnover, storage, and function in leaves and discuss emerging genetic engineering strategies targeted at enhancing triacylglycerol accumulation in biomass crops. Such plants could potentially be modified to produce oleochemical feedstocks or nutraceuticals. PMID:26845499

  11. Metal accumulating plants: Medium's role

    NASA Astrophysics Data System (ADS)

    Rabier, J.; Prudent, P.; Szymanska, B.; Mevy, J.-P.

    2003-05-01

    To evaluate phytoremediation potentialities by metal accumulation in tolerant plants, trials are carried out using in vitro cultures. Organie compounds influence on metal accumulation is studied with metals supplemented media. The tested compounds on zinc and lead absorption by Brassica juncea, are chelating agents (EDTA, citric acid) and soluble organic fractions of compost. EDTA seems to enhance the transfer of lead in plant but it is the opposite in the case of zinc. Citric acid stimulates root absorption for both zinc and lead. For the aqueous extracts of compost, variable effects are obtained according to the origin of compost (green wastes and food wastes). In'all tested conditions of cultures, zinc is mainly exported towards shoot while lead is stored in root.

  12. Mechanisms of intrahepatic triglyceride accumulation

    PubMed Central

    Ress, Claudia; Kaser, Susanne

    2016-01-01

    Hepatic steatosis defined as lipid accumulation in hepatocytes is very frequently found in adults and obese adolescents in the Western World. Etiologically, obesity and associated insulin resistance or excess alcohol intake are the most frequent causes of hepatic steatosis. However, steatosis also often occurs with chronic hepatitis C virus (HCV) infection and is also found in rare but potentially life-threatening liver diseases of pregnancy. Clinical significance and outcome of hepatic triglyceride accumulation are highly dependent on etiology and histological pattern of steatosis. This review summarizes current concepts of pathophysiology of common causes of hepatic steatosis, including non-alcoholic fatty liver disease (NAFLD), alcoholic fatty liver disease, chronic HCV infections, drug-induced forms of hepatic steatosis, and acute fatty liver of pregnancy. Regarding the pathophysiology of NAFLD, this work focuses on the close correlation between insulin resistance and hepatic triglyceride accumulation, highlighting the potential harmful effects of systemic insulin resistance on hepatic metabolism of fatty acids on the one side and the role of lipid intermediates on insulin signalling on the other side. Current studies on lipid droplet morphogenesis have identified novel candidate proteins and enzymes in NAFLD. PMID:26819531

  13. METHODS FOR RECONSTRUCTION OF RADIONUCLIDE COMPOSITION AND ACTIVITY OF FISSION PRODUCTS ACCUMULATED IN THE IRRADIATED URANIUM AT THE MOMENT OF ITS RADIOCHEMICAL REPROCESSING AT PLANT “B”, “MAYAK” PA IN THE EARLY 1950s

    SciTech Connect

    Glagolenko, Y. V.; Drozhko, Evgeniy G.; Mokrov, Y.; Rovny, Sergey I.; Lyzhkov, A. V.; Anspaugh, L. R.; Napier, Bruce A.

    2008-06-01

    The article describes calculation procedure for reconstruction of radionuclide composition and activity of fission fragments accumulated in the irridated uranium from “Mayak” PA graphite-uranium reactors at the moment, when irradiation is completed, and at the moment, when the uranium is transferred to radiochemical processing (plant B) in the early 1950s. The procedure includes a reactor model and a cooling pool model. It is based on archive data on monthly uranium unloading and loading in the reactor and in the cooling pool of each reactor. The objects of reconstruction include: order of reloading of uranium versus its location radius in the reactor core; duration of irradiation and radionuclide composition of fission fragments for each radius; order of uranium removal from the cooling pool; effective time of uranium storage in the pool; radionuclide composition and activity of fission fragments in the irradiated uranium delivered to radiochemical reprocessing daily and on average for each month. The model is intended for use in reconstruction of parameters of radionuclide release source into the atmosphere and the source of liquid radioactive waste generation at the “Mayak” PA radiochemical plant.

  14. Heat accumulation during sequential cortical bone drilling.

    PubMed

    Palmisano, Andrew C; Tai, Bruce L; Belmont, Barry; Irwin, Todd A; Shih, Albert; Holmes, James R

    2016-03-01

    Significant research exists regarding heat production during single-hole bone drilling. No published data exist regarding repetitive sequential drilling. This study elucidates the phenomenon of heat accumulation for sequential drilling with both Kirschner wires (K wires) and standard two-flute twist drills. It was hypothesized that cumulative heat would result in a higher temperature with each subsequent drill pass. Nine holes in a 3 × 3 array were drilled sequentially on moistened cadaveric tibia bone kept at body temperature (about 37 °C). Four thermocouples were placed at the center of four adjacent holes and 2 mm below the surface. A battery-driven hand drill guided by a servo-controlled motion system was used. Six samples were drilled with each tool (2.0 mm K wire and 2.0 and 2.5 mm standard drills). K wire drilling increased temperature from 5 °C at the first hole to 20 °C at holes 6 through 9. A similar trend was found in standard drills with less significant increments. The maximum temperatures of both tools increased from <0.5 °C to nearly 13 °C. The difference between drill sizes was found to be insignificant (P > 0.05). In conclusion, heat accumulated during sequential drilling, with size difference being insignificant. K wire produced more heat than its twist-drill counterparts. This study has demonstrated the heat accumulation phenomenon and its significant effect on temperature. Maximizing the drilling field and reducing the number of drill passes may decrease bone injury. PMID:26334198

  15. A New Dynamic Accumulator for Batch Updates

    NASA Astrophysics Data System (ADS)

    Wang, Peishun; Wang, Huaxiong; Pieprzyk, Josef

    A dynamic accumulator is an algorithm, which gathers together a large set of elements into a constant-size value such that for a given element accumulated, there is a witness confirming that the element was indeed included into the value, with a property that accumulated elements can be dynamically added and deleted into/from the original set such that the cost of an addition or deletion operation is independent of the number of accumulated elements. Although the first accumulator was presented ten years ago, there is still no standard formal definition of accumulators. In this paper, we generalize formal definitions for accumulators, formulate a security game for dynamic accumulators so-called Chosen Element Attack (CEA), and propose a new dynamic accumulator for batch updates based on the Paillier cryptosystem. Our construction makes a batch of update operations at unit cost. We prove its security under the extended strong RSA (es-RSA) assumption.

  16. Defining the cytosolic pathway of glutathione degradation in Arabidopsis thaliana: role of the ChaC/GCG family of γ-glutamyl cyclotransferases as glutathione-degrading enzymes and AtLAP1 as the Cys-Gly peptidase.

    PubMed

    Kumar, Shailesh; Kaur, Amandeep; Chattopadhyay, Banani; Bachhawat, Anand K

    2015-05-15

    Glutathione homoeostasis is critical to plant life and its adaptation to stress. The γ-glutamyl cycle of glutathione biosynthesis and degradation plays a pre-eminent role in glutathione homoeostasis. The genes encoding two enzymatic steps of glutathione degradation, the γ-glutamyl cyclotransferase (GGCT; acting on γ-glutamyl amino acids) and the Cys-Gly dipeptidase, have, however, lacked identification. We have investigated the family of GGCTs in Arabidopsis thaliana. We show through in vivo functional assays in yeast that all three members of the ChaC/GCG subfamily show significant activity towards glutathione but no detectable activity towards γ-glutamyl methionine. Biochemical characterization of the purified recombinant enzymes GGCT2;2 and GGCT2;3 further confirmed that they act specifically to degrade glutathione to yield 5-oxoproline and Cys-Gly peptide and show no significant activity towards γ-glutamyl cysteine. The Km for glutathione was 1.7 and 4.96 mM for GGCT2;2 and GGCT2;3 respectively and was physiologically relevant. Evaluation of representative members of other subfamilies indicates the absence of GGCTs from plants showing significant activity towards γ-glutamyl-amino acids as envisaged in the classical γ-glutamyl cycle. To identify the Cys-Gly peptidase, we evaluated leucine aminopeptidases (LAPs) as candidate enzymes. The cytosolic AtLAP1 (A. thaliana leucine aminopeptidase 1) and the putative chloroplastic AtLAP3 displayed activity towards Cys-Gly peptide through in vivo functional assays in yeast. Biochemical characterization of the in vitro purified hexameric AtLAP1 enzyme revealed a Km for Cys-Gly of 1.3 mM that was physiologically relevant and indicated that AtLAP1 represents a cytosolic Cys-Gly peptidase activity of A. thaliana. The studies provide new insights into the functioning of the γ-glutamyl cycle in plants. PMID:25716890

  17. A type I collagen reporter gene construct for protein engineering studies. Functional equivalence of transfected reporter COL1A1 and endogenous gene products during biosynthesis and in vitro extracellular matrix accumulation.

    PubMed

    Lamandé, S R; Bateman, J F

    1993-07-15

    A type I collagen reporter gene construct, designed to facilitate detailed analysis of the consequences of introduced structural and regulatory mutations on collagen biosynthesis and participation in the extracellular matrix, was produced by site-directed mutagenesis of the mouse COL1A1 gene. The reporter construct, pWTCI-Ile822, carried a single base change which converted the codon for amino acid 822 of the triple helix from methionine to isoleucine. This change allowed the reporter protein, [Ile822]alpha 1(I), to be distinguished from the wild-type alpha 1(I), and quantified, by its altered CNBr cleavage pattern. In mouse Mov13 cells, which synthesize no endogenous pro alpha 1(I), reporter chains associated with endogenous pro alpha 2(I), formed pepsin-stable triple helices and were secreted efficiently from the cell. The thermal stability of wild-type molecules and molecules containing the reporter [Ile822]alpha 1(I) chains was identical. The biosynthetic characteristics of wild-type and reporter chains were directly compared in stably transfected 3T6 cells. These cells did not make a distinction between reporter and endogenous alpha 1(I) chains, which were secreted from the cells at the same rate and were processed and deposited into the 3T6 cell in vitro accumulated extracellular matrix with equal efficiency. These data demonstrate that the helical sequence alteration in the reporter protein is functionally neutral and that the reporter construct, pWTCI-Ile822, is a suitable vector for the analysis of the biochemical effects of site-directed mutations in the putative COL1A1 functional domains. PMID:8343119

  18. Physiological Expression and Accumulation of the Products of Two Upstream Open Reading Frames mrtl and MycHex1 Along With p64 and p67 Myc From the Human c-myc Locus.

    PubMed

    Ji, Mi Hong; Kim, Seung-Ki; Kim, Chae-Yong; Phi, Ji Hoon; Jun, Hyun Jin; Blume, Scott W; Choi, Hyoung Soo

    2016-06-01

    In addition to the canonical c-Myc p64 and p67 proteins, the human c-myc locus encodes two distinct proteins, mrtl (myc-related translation/localization regulatory factor) and MycHex1 (Myc Human Exon 1), from the upstream open reading frames within the 5'-untranslated region of the c-myc P0 mRNA. The aim of this study is to examine simultaneously, for the first time, mrtl, MycHex1, c-Myc p64, and p67 in human tumor cell lines and pediatric brain tumor tissues. Western blot analysis demonstrated endogenous mrtl, MycHex1, c-Myc p64, and p67 simultaneously. The relative abundance of mrtl and MycHex1 were consistent among a variety of human tumor cell lines, and the relative intensities of mrtl and MycHex1 correlated positively. Confocal imaging revealed mrtl predominantly localized to the nuclear envelope, along with prominent reticular pattern in the cytoplasm. MycHex1 was observed as a series of bright foci located within the nucleus, a subset of which colocalized with fibrillarin. mrtl and MycHex1 co-immunoprecipitated with RACK1, c-Myc, fibrillarin, coilin, and with each other. These findings suggest that mrtl and MycHex1 have multiple interaction partners in both the nucleus and cytoplasm. Sequence analyses confirmed a known polymorphism of mrtl at base 1965 (G>T) and new mutations at bases 1900 (C>G) and 1798 (C>G). Evidence is presented for expression and stable accumulation of all four proteins encoded by three distinct non-overlapping open reading frames within the human c-myc locus. Additional work is warranted to further elucidate the functional or regulatory roles of these molecules in regulation of c-Myc and in oncogenesis. J. Cell. Biochem. 117: 1407-1418, 2016. © 2015 Wiley Periodicals, Inc. PMID:26552949

  19. Preservation of ancient impact ages on the R chondrite parent body: 40Ar/39Ar age of hornblende-bearing R chondrite LAP 04840

    NASA Astrophysics Data System (ADS)

    Righter, K.; Cosca, M. A.; Morgan, L. E.

    2016-09-01

    The hornblende- and biotite-bearing R chondrite LAP 04840 is a rare kind of meteorite possibly containing outer solar system water stored during metamorphism or postshock annealing deep within an asteroid. Because little is known regarding its age and origin, we determined 40Ar/39Ar ages on hornblende-rich separates of the meteorite, and obtained plateau ages of 4340(±40) to 4380(±30) Ma. These well-defined plateau ages, coupled with evidence for postshock annealing, indicate this meteorite records an ancient shock event and subsequent annealing. The age of 4340-4380 Ma (or 4.34-4.38 Ga) for this and other previously dated R chondrites is much older than most impact events recorded by ordinary chondrites and points to an ancient event or events that predated the late heavy bombardment that is recorded in so many meteorites and lunar samples.

  20. Dynamic strain distribution measurement and crack detection of an adhesive-bonded single-lap joint under cyclic loading using embedded FBG

    NASA Astrophysics Data System (ADS)

    Ning, Xiaoguang; Murayama, Hideaki; Kageyama, Kazuro; Wada, Daichi; Kanai, Makoto; Ohsawa, Isamu; Igawa, Hirotaka

    2014-10-01

    In this study, the dynamic strain distribution measurement of an adhesive-bonded single-lap joint was carried out in a cyclic load test using a fiber Bragg grating (FBG) sensor embedded into the adhesive/adherend interface along the overlap length direction. Unidirectional carbon fiber reinforced plastic (CFRP) substrates were bonded by epoxy resin to form the joint, and the FBG sensor was embedded into the surface of one substrate during its curing. The measurement was carried out with a sampling rate of 5 Hz by the sensing system, based on the optical frequency domain reflectometry (OFDR) throughout the test. A finite element analysis (FEA) was performed for the measurement evaluation using a three-dimensional model, which included the embedded FBG sensor. The crack detection method, based on the longitudinal strain distribution measurement, was introduced and performed to estimate the cracks that occurred at the adhesive/adherend interface in the test.

  1. SRB/SLEEC (Solid Rocket Booster/Shingle Lap Extendible Exit Cone) feasibility study, volume 2. Appendix A: Design study for a SLEEC actuation system

    NASA Technical Reports Server (NTRS)

    Thompson, D. S.

    1986-01-01

    The results are presented of a design feasibility study of a self-contained (powered) actuation system for a Shingle Lap Extendible Exit Cone (SLEEC) for Transportation System (STS). The evolution of the SLEEC actuation system design is reviewed, the final design concept is summarized, and the results of the detailed study of the final concept of the actuation system are treated. A conservative design using proven mechanical components was established as a major program priority. The final mechanical design has a very low development risk since the components, which consist of ballscrews, gearing, flexible shaft drives, and aircraft cables, have extensive aerospace applications and a history of proven reliability. The mathematical model studies have shown that little or no power is required to deploy the SLEEC actuation system because acceleration forces and internal pressure from the rocket plume provide the required energies. A speed control brake is incorporated in the design in order to control the rate of deployment.

  2. A record of all marker bands found in the upper rivet rows of 2 adjacent bays from a fuselage lap splice joint

    NASA Technical Reports Server (NTRS)

    Willard, Scott A.

    1995-01-01

    A full scale fuselage test article was subjected to 60,000 load cycles (pressurizations) to study the effect of widespread fatigue damage in fuselage structures. Every 10,000 cycles coded marker block loading sequences were used to mark the fracture surfaces of the fatigue cracks propagating within the panel. The loading sequences consisted of series of underloads combined with a series of full pressurizations. The combination of loads and underloads marked the fracture surfaces with marker bands that could later be used to reconstruct the fatigue crack growth history of selected regions within the test article. Thirty rivet holes comprising the upper rivet rows from two adjacent bays (bays #3 and #4) from a fuselage lap splice joint were examined for the purpose of this study. Optical and scanning electron microscopy (SEM) were used to locate the marker bands.

  3. Preservation of ancient impact ages on the R chondrite parent body: 40Ar/39Ar age of hornblende-bearing R chondrite LAP 04840

    NASA Astrophysics Data System (ADS)

    Righter, K.; Cosca, M. A.; Morgan, L. E.

    2016-07-01

    The hornblende- and biotite-bearing R chondrite LAP 04840 is a rare kind of meteorite possibly containing outer solar system water stored during metamorphism or postshock annealing deep within an asteroid. Because little is known regarding its age and origin, we determined 40Ar/39Ar ages on hornblende-rich separates of the meteorite, and obtained plateau ages of 4340(±40) to 4380(±30) Ma. These well-defined plateau ages, coupled with evidence for postshock annealing, indicate this meteorite records an ancient shock event and subsequent annealing. The age of 4340-4380 Ma (or 4.34-4.38 Ga) for this and other previously dated R chondrites is much older than most impact events recorded by ordinary chondrites and points to an ancient event or events that predated the late heavy bombardment that is recorded in so many meteorites and lunar samples.

  4. Accumulation of artificial radionuclides in agricultural plants in the area used for surface nuclear tests.

    PubMed

    Kozhakhanov, T E; Lukashenko, S N; Larionova, N V

    2014-11-01

    The paper reports on the study of artificial radionuclide accumulation in agricultural crops grown at the territory with high concentration of radionuclides, and first of all - with high concentration of transuranium elements. As a result of this work, peculiarities of accumulation and distribution of artificial radionuclides in the vegetative and generative organs of the studied plants have been revealed. Basic accumulation factors have been found for (137)Cs, (90)Sr, (239+240)Pu, and (241)Am in agricultural products. Accumulation factor dependence on type of planting was found for the investigated types of plants. It has been found that the vegetative organs accumulate radionuclides most of all. PMID:25128979

  5. Analysis of the Side-Lap Effect on Full-Waveform LIDAR Data Acquisition for the Estimation of Forest Structure Variables

    NASA Astrophysics Data System (ADS)

    Crespo-Peremarch, P.; Ruiz, L. A.; Balaguer-Beser, A.; Estornell, J.

    2016-06-01

    LiDAR full-waveform provides a better description of the physical and forest vertical structure properties than discrete LiDAR since it registers the full wave that interacts with the canopy. In this paper, the effect of flight line side-lap is analysed on forest structure and canopy fuel variables estimations. Differences are related to pulse density changes between flight stripe side-lap areas, varying the point density between 2.65 m-2 and 33.77 m-2 in our study area. These differences modify metrics extracted from data and therefore variable values estimated from these metrics such as forest stand variables. In order to assess this effect, 64 pairwise samples were selected in adjacent areas with similar canopy structure, but having different point densities. Two parameters were tested and evaluated to minimise this effect: voxel size and voxel value assignation testing maximum, mean, median, mode, percentiles 90 and 95. Student's t-test or Wilcoxon test were used for the comparison of paired samples. Moreover, the absolute value of standardised paired samples was calculated to quantify dissimilarities. It was concluded that optimizing voxel size and voxel value assignation minimised the effect of point density variations and homogenised full-waveform metrics. Height/median ratio (HTMR) and Vertical distribution ratio (VDR) had the lowest variability between different densities, and Return waveform energy (RWE) reached the best improvement with respect to initial data, being the difference between standardised paired samples 1.28 before and 0.69 after modification.

  6. Analysis of the La:P ratio in lake sediments - Vertical and spatial distribution assessed by a multiple-core survey.

    PubMed

    Yasseri, Said; Epe, Tim S

    2016-06-15

    In recent years, lanthanum modified bentonite has been increasingly applied to eutrophic lakes with the aim of converting potentially bio-available forms of phosphorus in sediments into biologically unavailable forms. In many of these applications, however, no attempts have been made to assess the efficiency and efficacy of the measure in terms of its effect on the sediment. In this study, we collected sediment cores from a heavily eutrophied lake that has previously been treated with lanthanum modified clay. This restoration method is based on the strong ionic bond formed between lanthanum and phosphate which results in the formation of LaPO4 (Rhabdophane) in the sediment. In order to determine the changes that had occurred in the sediments as a result of the addition of the clay, we measured the vertical distribution of lanthanum in the collected cores, calculated La:P ratios of the different sediment layers and used the ratios to determine whether or not the applied dosage was sufficient. By means of the geostatistical method of kriging these values were transferred into maps of different depth intervals to visualize the results. The results indicate that the La:P ratio may be a useful tool which allows lake managers to measure the vertical distribution of lanthanum in sediments following treatments and determine whether or not dosages are sufficient to permanently render sediment phosphorus biologically unavailable. The method may also provide a basis on which to decide whether or not smaller reapplications are needed and can be used to control the dispersion of the material. PMID:26250755

  7. [Dry matter accumulation in rice aboveground part: quantitative simulation].

    PubMed

    Li, Yan-Da; Tang, Liang; Chen, Qing-Chun; Zhang, Yu-Ping; Cao, Wei-Xing; Zhu, Yan

    2010-06-01

    A field experiment with four rice (Oryza sativa L.) cultivars and different nitrogen application rates was conducted, with the dry matter accumulation (DMA) in the cultivars aboveground part measured at their main growth stages. The dynamic model of relative dry matter accumulation (RDMA) was established with the normalized DMA and TEP (product of thermal effectiveness and PAR) from emergence to maturity, and the temporal characteristics of DMA changes was quantitatively analyzed based on the RDMA model. The dynamic changes of the RDMA could be well described with Richards equation, i. e., RDMA = 1.0157/(1 +e(3.6329-7.5907xRTEP)) 1/0.5574 (r = 0.9938). The model was validated with independent field experiment datasets, involving different eco-sites, cultivars, and nitrogen application rates. The RMSE (root mean square error) between the simulated and observed values of DMA at varied RTEP was 0.86 t x hm(-2). According to the two inflexion points of dry matter accumulation rate equation, the whole process of dry matter accumulation could be divided into early, middle, and late phases. The maximum dry matter accumulation rate (AR(max)), relative TEP at AR(max), and relative dry matter accumulation at AR(max) were found to be 2.24, 0.56, and 0.46, respectively. PMID:20873627

  8. Phorbol esters modulate cyclic AMP accumulation in porcine thyroid cells

    SciTech Connect

    Emoto, T.; Kasai, K.; Hiraiwa, M.; Shimoda, S.

    1988-01-01

    In cultured porcine thyroid cells, during 60 min incubation phorbol 12-myristate 13-acetate (PMA) had no effect on basal cyclic AMP accumulation and slightly stimulated cyclic AMP accumulation evoked by thyroid stimulating hormone (TSH) or forskolin. Cholera toxin-induced cyclic AMP accumulation was significantly stimulated by PMA. On the other hand, cyclic AMP accumulation evoked by prostaglandin E/sub 1/ or E/sub 2/ (PGE/sub 1/ and PGE/sub 2/) was markedly depressed by simultaneous addition of PMA. These opposing effects of PMA on cyclic AMP accumulation evoked by PGE and cholera toxin were observed in a dose-related fashion, with half-maximal effect of around 10/sup -9/ M in either case. The almost same effects of PMA on cyclic AMP accumulation in basal and stimulated conditions were also observed in freshly prepared thyroid cells. The present study was performed in the presence of phosphodiesterase inhibitor, 3-iso-butyl-1-methylxanthine (IBMX), indicating that PMA affected adenylate cyclase activity. Therefore, it is suggested that PMA may modulate the production of cyclic AMP in response to different stimuli, possibly by affecting several sites in the adenylate cyclase complex in thyroid cells.

  9. Racial Differences in Patterns of Wealth Accumulation

    ERIC Educational Resources Information Center

    Gittleman, Maury; Wolff, Edward N.

    2004-01-01

    The race differences in patterns of asset accumulations were examined using PSD data for 1984, 1989 and 1994. The results indicate that inheritances led to wealth accumulations among whites as compared to the African Americans.

  10. Neurodegeneration with brain iron accumulation (NBIA)

    MedlinePlus

    ... gov/ency/article/001225.htm Neurodegeneration with brain iron accumulation (NBIA) To use the sharing features on this page, please enable JavaScript. Neurodegeneration with brain iron accumulation (formerly known as Hallervorden-Spatz disease) is ...

  11. Accumulation and fragmentation of plastic debris in global environments

    PubMed Central

    Barnes, David K. A.; Galgani, Francois; Thompson, Richard C.; Barlaz, Morton

    2009-01-01

    One of the most ubiquitous and long-lasting recent changes to the surface of our planet is the accumulation and fragmentation of plastics. Within just a few decades since mass production of plastic products commenced in the 1950s, plastic debris has accumulated in terrestrial environments, in the open ocean, on shorelines of even the most remote islands and in the deep sea. Annual clean-up operations, costing millions of pounds sterling, are now organized in many countries and on every continent. Here we document global plastics production and the accumulation of plastic waste. While plastics typically constitute approximately 10 per cent of discarded waste, they represent a much greater proportion of the debris accumulating on shorelines. Mega- and macro-plastics have accumulated in the highest densities in the Northern Hemisphere, adjacent to urban centres, in enclosed seas and at water convergences (fronts). We report lower densities on remote island shores, on the continental shelf seabed and the lowest densities (but still a documented presence) in the deep sea and Southern Ocean. The longevity of plastic is estimated to be hundreds to thousands of years, but is likely to be far longer in deep sea and non-surface polar environments. Plastic debris poses considerable threat by choking and starving wildlife, distributing non-native and potentially harmful organisms, absorbing toxic chemicals and degrading to micro-plastics that may subsequently be ingested. Well-established annual surveys on coasts and at sea have shown that trends in mega- and macro-plastic accumulation rates are no longer uniformly increasing: rather stable, increasing and decreasing trends have all been reported. The average size of plastic particles in the environment seems to be decreasing, and the abundance and global distribution of micro-plastic fragments have increased over the last few decades. However, the environmental consequences of such microscopic debris are still poorly

  12. 47 CFR 32.3100 - Accumulated depreciation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Accumulated depreciation. 32.3100 Section 32... Accumulated depreciation. (a) This account shall include the accumulated depreciation associated with the... with depreciation amounts concurrently charged to Account 6561, Depreciation...

  13. 46 CFR 58.30-25 - Accumulators.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Accumulators. 58.30-25 Section 58.30-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-25 Accumulators. (a) An accumulator is an unfired pressure vessel in which energy is...

  14. Factors Influencing the Accumulation and Subsurface Transport of Fecal Indicator Bacteria near the Shoreline at Freshwater Beaches

    NASA Astrophysics Data System (ADS)

    Wu, M. Z.; O'Carroll, D. M.; Vogel, L. J.; Robinson, C. E.

    2015-12-01

    Beach sand near the shoreline acts as a reservoir for fecal contaminants with fecal indicator bacteria (FIB) often orders of magnitude higher than in adjacent surface waters. This reservoir poses a human health risk and can also act as an important non-point contamination source for surface waters. Beach water quality advisories or closures can be issued when FIB (Escherichia coli (E. coli), enterococci (ENT)) concentrations are elevated in the surface water. The factors controlling the transport and accumulation of FIB in the foreshore sand are not well understood, though this is required to manage and mitigate this source. Multiple sources may contribute to the accumulation of FIB in sand, with recent studies suggesting that the continuous influx of surface water across the sediment-water interface may be a dominant source at many beaches.The study objective was to develop understanding of the physical processes controlling the accumulation and transport of FIB in beach sand. Field measurements were combined with numerical modelling to evaluate the role of low-energy lapping waves in delivering FIB to the saturated foreshore sand at freshwater beaches. E. coli and ENT were measured at two beaches in Ontario, Canada at depths of up to 1 and 2 m, respectively, below the water table. A numerical model simulating wave-induced groundwater recirculations coupled with microbial transport (using colloid filtration theory) showed that the different FIB distributions measured at the two beaches was due mainly to the different beach slope and terrestrial groundwater flow. The model was applied to assess the impact of beach, wave and bacterial parameters on FIB accumulation. The infiltration zone width, average infiltration velocity and infiltration rate were shown to ultimately control the amount and spatial distribution of FIB in the sand. The study findings are important in understanding factors controlling the transport of FIB at the sediment-water interface of

  15. Chip integrated fuel cell accumulator

    NASA Astrophysics Data System (ADS)

    Frank, M.; Erdler, G.; Frerichs, H.-P.; Müller, C.; Reinecke, H.

    A unique new design of a chip integrated fuel cell accumulator is presented. The system combines an electrolyser and a self-breathing polymer electrolyte membrane (PEM) fuel cell with integrated palladium hydrogen storage on a silicon substrate. Outstanding advantages of this assembly are the fuel cell with integrated hydrogen storage, the possibility of refuelling it by electrolysis and the opportunity of simply refilling the electrolyte by adding water. By applying an electrical current, wiring the palladium hydrogen storage as cathode and the counter-electrode as anode, the electrolyser produces hydrogen at the palladium surface and oxygen at the electrolyser cell anode. The generated hydrogen is absorbed by the palladium electrode and the hydrogen storage is refilled consequently enabling the fuel cell to function.

  16. Regulation of starch and lipid accumulation in a microalga Chlorella sorokiniana.

    PubMed

    Li, Tingting; Gargouri, Mahmoud; Feng, Jie; Park, Jeong-Jin; Gao, Difeng; Miao, Chao; Dong, Tao; Gang, David R; Chen, Shulin

    2015-03-01

    Microalgae have attracted growing attention due to their potential in biofuel feedstock production. However, current understanding of the regulatory mechanisms for lipid biosynthesis and storage in microalgae is still limited. This study revealed that the microalga Chlorella sorokiniana showed sequential accumulation of starch and lipids. When nitrogen was replete and/or depleted over a short period, starch was the predominant carbon storage form with basal levels of lipid accumulation. After prolonged nitrogen depletion, lipid accumulation increased considerably, which was partially due to starch degradation, as well as the turnover of primary metabolites. Lipid accumulation is also strongly dependent on the linear electron flow of photosynthesis, peaking at lower light intensities. Collectively, this study reveals a relatively clear regulation pattern of starch and lipid accumulation that is basically controlled by nitrogen levels. The mixotrophic growth of C. sorokiniana shows promise for biofuel production in terms of lipid accumulation in the final biomass. PMID:25616239

  17. Guidelines for Waste Accumulation Areas (WAAs)

    SciTech Connect

    Not Available

    1991-07-01

    The purpose of this document is to set conditions for establishing and maintaining areas for the accumulation of hazardous waste at LBL. Areas designed for accumulation of these wastes in quantities greater than 100 kg (220 lb) per month of solid waste or 55 gallons per month of liquid waste are called Waste Accumulation Areas (WAAs). Areas designed for accumulation of wastes in smaller amounts are called Satellite Accumulation Areas (SAAs). This document provides guidelines for employee and organizational responsibilities for WAAs; constructing a WAA; storing waste in a WAA; operating and maintaining a WAA, and responding to spills in a WAA. 4 figs.

  18. Ischaemic accumulation of succinate controls reperfusion injury through mitochondrial ROS.

    PubMed

    Chouchani, Edward T; Pell, Victoria R; Gaude, Edoardo; Aksentijević, Dunja; Sundier, Stephanie Y; Robb, Ellen L; Logan, Angela; Nadtochiy, Sergiy M; Ord, Emily N J; Smith, Anthony C; Eyassu, Filmon; Shirley, Rachel; Hu, Chou-Hui; Dare, Anna J; James, Andrew M; Rogatti, Sebastian; Hartley, Richard C; Eaton, Simon; Costa, Ana S H; Brookes, Paul S; Davidson, Sean M; Duchen, Michael R; Saeb-Parsy, Kourosh; Shattock, Michael J; Robinson, Alan J; Work, Lorraine M; Frezza, Christian; Krieg, Thomas; Murphy, Michael P

    2014-11-20

    Ischaemia-reperfusion injury occurs when the blood supply to an organ is disrupted and then restored, and underlies many disorders, notably heart attack and stroke. While reperfusion of ischaemic tissue is essential for survival, it also initiates oxidative damage, cell death and aberrant immune responses through the generation of mitochondrial reactive oxygen species (ROS). Although mitochondrial ROS production in ischaemia reperfusion is established, it has generally been considered a nonspecific response to reperfusion. Here we develop a comparative in vivo metabolomic analysis, and unexpectedly identify widely conserved metabolic pathways responsible for mitochondrial ROS production during ischaemia reperfusion. We show that selective accumulation of the citric acid cycle intermediate succinate is a universal metabolic signature of ischaemia in a range of tissues and is responsible for mitochondrial ROS production during reperfusion. Ischaemic succinate accumulation arises from reversal of succinate dehydrogenase, which in turn is driven by fumarate overflow from purine nucleotide breakdown and partial reversal of the malate/aspartate shuttle. After reperfusion, the accumulated succinate is rapidly re-oxidized by succinate dehydrogenase, driving extensive ROS generation by reverse electron transport at mitochondrial complex I. Decreasing ischaemic succinate accumulation by pharmacological inhibition is sufficient to ameliorate in vivo ischaemia-reperfusion injury in murine models of heart attack and stroke. Thus, we have identified a conserved metabolic response of tissues to ischaemia and reperfusion that unifies many hitherto unconnected aspects of ischaemia-reperfusion injury. Furthermore, these findings reveal a new pathway for metabolic control of ROS production in vivo, while demonstrating that inhibition of ischaemic succinate accumulation and its oxidation after subsequent reperfusion is a potential therapeutic target to decrease ischaemia

  19. Ischaemic accumulation of succinate controls reperfusion injury through mitochondrial ROS

    PubMed Central

    Gaude, Edoardo; Aksentijević, Dunja; Sundier, Stephanie Y.; Robb, Ellen L.; Logan, Angela; Nadtochiy, Sergiy M.; Ord, Emily N. J.; Smith, Anthony C.; Eyassu, Filmon; Shirley, Rachel; Hu, Chou-Hui; Dare, Anna J.; James, Andrew M.; Rogatti, Sebastian; Hartley, Richard C.; Eaton, Simon; Costa, Ana S.H.; Brookes, Paul S.; Davidson, Sean M.; Duchen, Michael R.; Saeb-Parsy, Kourosh; Shattock, Michael J.; Robinson, Alan J.; Work, Lorraine M.; Frezza, Christian; Krieg, Thomas; Murphy, Michael P.

    2014-01-01

    Ischaemia-reperfusion (IR) injury occurs when blood supply to an organ is disrupted and then restored, and underlies many disorders, notably heart attack and stroke. While reperfusion of ischaemic tissue is essential for survival, it also initiates oxidative damage, cell death, and aberrant immune responses through generation of mitochondrial reactive oxygen species (ROS)1-5. Although mitochondrial ROS production in IR is established, it has generally been considered a non-specific response to reperfusion1,3. Here, we developed a comparative in vivo metabolomic analysis and unexpectedly identified widely conserved metabolic pathways responsible for mitochondrial ROS production during IR. We showed that selective accumulation of the citric acid cycle (CAC) intermediate succinate is a universal metabolic signature of ischaemia in a range of tissues and is responsible for mitochondrial ROS production during reperfusion. Ischaemic succinate accumulation arises from reversal of succinate dehydrogenase (SDH), which in turn is driven by fumarate overflow from purine nucleotide breakdown and partial reversal of the malate/aspartate shuttle. Upon reperfusion, the accumulated succinate is rapidly re-oxidised by SDH, driving extensive ROS generation by reverse electron transport (RET) at mitochondrial complex I. Decreasing ischaemic succinate accumulation by pharmacological inhibition is sufficient to ameliorate in vivo IR injury in murine models of heart attack and stroke. Thus, we have identified a conserved metabolic response of tissues to ischaemia and reperfusion that unifies many hitherto unconnected aspects of IR injury. Furthermore, these findings reveal a novel pathway for metabolic control of ROS production in vivo, while demonstrating that inhibition of ischaemic succinate accumulation and its oxidation upon subsequent reperfusion is a potential therapeutic target to decrease IR injury in a range of pathologies. PMID:25383517

  20. Nutrient-contaminant (Pu) plant accumulation model

    SciTech Connect

    Cowan, C.E.; Jenne, E.A.; Simpson, J.C.; Cataldo, D.A.

    1981-12-01

    A model was developed which simulates the movement and daily accumulation of nutrients and contaminants in crop plants resulting from known physiological processes in the plant. In the model, the daily contaminant accumulation is governed by daily increase in plant biomass derived from photosynthesis and by the specified thermodynamic activity of the bioavailable contaminant species in soil or hydroponic solutin. Total accumulation and resulting concentration in the plant's root, stem and branch, leaf, and reproductive compartments can be simulated any time during the growing season. Parameters were estimated from data on plutonium accumulation in soybeans and the model was calibrated against this same data set. The plutonium distribution in the plant was found to be most sensitive to parameters related to leaf accumulation. Contamination at different times during the growing season resulted in a large change in predicted leaf accumulation but very little change in predicted accumulation in other plant parts except when contamination occurred very late in the growing season.