Sample records for biodynamics

  1. Molecular Biodynamers: Dynamic Covalent Analogues of Biopolymers

    PubMed Central

    2017-01-01

    Conspectus Constitutional dynamic chemistry (CDC) features the use of reversible linkages at both molecular and supramolecular levels, including reversible covalent bonds (dynamic covalent chemistry, DCC) and noncovalent interactions (dynamic noncovalent chemistry, DNCC). Due to its inherent reversibility and stimuli-responsiveness, CDC has been widely utilized as a powerful tool for the screening of bioactive compounds, the exploitation of receptors or substrates driven by molecular recognition, and the fabrication of constitutionally dynamic materials. Implementation of CDC in biopolymer science leads to the generation of constitutionally dynamic analogues of biopolymers, biodynamers, at the molecular level (molecular biodynamers) through DCC or at the supramolecular level (supramolecular biodynamers) via DNCC. Therefore, biodynamers are prepared by reversible covalent polymerization or noncovalent polyassociation of biorelevant monomers. In particular, molecular biodynamers, biodynamers of the covalent type whose monomeric units are connected by reversible covalent bonds, are generated by reversible polymerization of bio-based monomers and can be seen as a combination of biopolymers with DCC. Owing to the reversible covalent bonds used in DCC, molecular biodynamers can undergo continuous and spontaneous constitutional modifications via incorporation/decorporation and exchange of biorelevant monomers in response to internal or external stimuli. As a result, they behave as adaptive materials with novel properties, such as self-healing, stimuli-responsiveness, and tunable mechanical and optical character. More specifically, molecular biodynamers combine the biorelevant characters (e.g., biocompatibility, biodegradability, biofunctionality) of bioactive monomers with the dynamic features of reversible covalent bonds (e.g., changeable, tunable, controllable, self-healing, and stimuli-responsive capacities), to realize synergistic properties in one system. In addition, molecular biodynamers are commonly produced in aqueous media under mild or even physiological conditions to suit their biorelated applications. In contrast to static biopolymers emphasizing structural stability and unity by using irreversible covalent bonds, molecular biodynamers are seeking relative structural adaptability and diversity through the formation of reversible covalent bonds. Based on these considerations, molecular biodynamers are capable of reorganizing their monomers, generating, identifying, and amplifying the fittest structures in response to environmental factors. Hence, molecular biodynamers have received considerable research attention over the past decades. Accordingly, the construction of molecular biodynamers through equilibrium polymerization of nucleobase-, carbohydrate- or amino-acid-based monomers can lead to the fabrication of dynamic analogues of nucleic acids (DyNAs), polysaccharides (glycodynamers), or proteins (dynamic proteoids), respectively. In this Account, we summarize recent advances in developing different types of molecular biodynamers as structural or functional biomimetics of biopolymers, including DyNAs, glycodynamers, and dynamic proteoids. We introduce how chemists utilize various reversible reactions to generate molecular biodynamers with specific sequences and well-ordered structures in aqueous medium. We also discuss and list their potential applications in various research fields, such as drug delivery, drug discovery, gene sensing, cancer diagnosis, and treatment. PMID:28169527

  2. Problems in modeling man machine control behavior in biodynamic environments

    NASA Technical Reports Server (NTRS)

    Jex, H. R.

    1972-01-01

    Reviewed are some current problems in modeling man-machine control behavior in a biodynamic environment. It is given in two parts: (1) a review of the models which are appropriate for manual control behavior and the added elements necessary to deal with biodynamic interfaces; and (2) a review of some biodynamic interface pilot/vehicle problems which have occurred, been solved, or need to be solved.

  3. Recent advances in biodynamics of human hand-arm system.

    PubMed

    Dong, Ren G; Wu, John Z; Welcome, Daniel E

    2005-07-01

    The biodynamics of human hand-arm system is one of the most important foundations for the measurement, evaluation, and risk assessment of hand-transmitted vibration (HTV) exposure. This paper presents a new conceptual model relating factors influencing cause-effect relationships for HTV exposure, a new study strategy, and a comprehensive review of the recent advances in the biodynamics closely associated with HTV exposure. The review covers the following five aspects: theoretical modeling of biodynamic responses, vibration transmissibility, driving-point biodynamic responses, evaluation of anti-vibration gloves, and applied forces. This review finds that some significant advances in each of these aspects have been achieved in the recent years. Several important issues and problems in the biodynamic measurement have been identified and resolved, which has significantly helped improve the reliability and accuracy of the experimental data. The results reported in recent years suggest that, from the point of view of biodynamics, the frequency weighting specified in ISO 5349-1 (2001) overestimates the low frequency effect but underestimates the high frequency effect on the fingers and hand. The major problems, issues, and topics for further studies are also outlined in this paper. It is anticipated that the further studies of the biodynamics of the system will eventually lead to establishment of a robust vibration exposure theory. Although this review focuses on the biodynamics of the hand-arm system, the fundamental concepts and some methodologies reviewed in this paper may also be applicable for the study of whole-body vibration exposure.

  4. Growth, Yield and Fruit Quality of Grapevines under Organic and Biodynamic Management

    PubMed Central

    Döring, Johanna; Frisch, Matthias; Tittmann, Susanne; Stoll, Manfred; Kauer, Randolf

    2015-01-01

    The main objective of this study was to determine growth, yield and fruit quality of grapevines under organic and biodynamic management in relation to integrated viticultural practices. Furthermore, the mechanisms for the observed changes in growth, yield and fruit quality were investigated by determining nutrient status, physiological performance of the plants and disease incidence on bunches in three consecutive growing seasons. A field trial (Vitis vinifera L. cv. Riesling) was set up at Hochschule Geisenheim University, Germany. The integrated treatment was managed according to the code of good practice. Organic and biodynamic plots were managed according to Regulation (EC) No 834/2007 and Regulation (EC) No 889/2008 and according to ECOVIN- and Demeter-Standards, respectively. The growth and yield of the grapevines differed strongly among the different management systems, whereas fruit quality was not affected by the management system. The organic and the biodynamic treatments showed significantly lower growth and yield in comparison to the integrated treatment. The physiological performance was significantly lower in the organic and the biodynamic systems, which may account for differences in growth and cluster weight and might therefore induce lower yields of the respective treatments. Soil management and fertilization strategy could be responsible factors for these changes. Yields of the organic and the biodynamic treatments partially decreased due to higher disease incidence of downy mildew. The organic and the biodynamic plant protection strategies that exclude the use of synthetic fungicides are likely to induce higher disease incidence and might partially account for differences in the nutrient status of vines under organic and biodynamic management. Use of the biodynamic preparations had little influence on vine growth and yield. Due to the investigation of important parameters that induce changes especially in growth and yield of grapevines under organic and biodynamic management the study can potentially provide guidance for defining more effective farming systems. PMID:26447762

  5. Biodynamic Doppler imaging of subcellular motion inside 3D living tissue culture and biopsies (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Nolte, David D.

    2016-03-01

    Biodynamic imaging is an emerging 3D optical imaging technology that probes up to 1 mm deep inside three-dimensional living tissue using short-coherence dynamic light scattering to measure the intracellular motions of cells inside their natural microenvironments. Biodynamic imaging is label-free and non-invasive. The information content of biodynamic imaging is captured through tissue dynamics spectroscopy that displays the changes in the Doppler signatures from intracellular constituents in response to applied compounds. The affected dynamic intracellular mechanisms include organelle transport, membrane undulations, cytoskeletal restructuring, strain at cellular adhesions, cytokinesis, mitosis, exo- and endo-cytosis among others. The development of 3D high-content assays such as biodynamic profiling can become a critical new tool for assessing efficacy of drugs and the suitability of specific types of tissue growth for drug discovery and development. The use of biodynamic profiling to predict clinical outcome of living biopsies to cancer therapeutics can be developed into a phenotypic companion diagnostic, as well as a new tool for therapy selection in personalized medicine. This invited talk will present an overview of the optical, physical and physiological processes involved in biodynamic imaging. Several different biodynamic imaging modalities include motility contrast imaging (MCI), tissue-dynamics spectroscopy (TDS) and tissue-dynamics imaging (TDI). A wide range of potential applications will be described that include process monitoring for 3D tissue culture, drug discovery and development, cancer therapy selection, embryo assessment for in-vitro fertilization and artificial reproductive technologies, among others.

  6. Soil microbiota respond to green manure in organic vineyards.

    PubMed

    Longa, C M O; Nicola, L; Antonielli, L; Mescalchin, E; Zanzotti, R; Turco, E; Pertot, I

    2017-12-01

    The aim of this work was to investigate the effects of biodynamic management with and without the addition of green manure, in comparison with organic management, on the microbiota in vineyards soil. High throughput sequencing was used to compare the taxonomic structure of the soil bacterial and fungal communities from vineyards managed with different methods (organic, biodynamic or biodynamic with green manure). Our results showed that microbial communities associated with biodynamic and organic farming systems were very similar, while green manure was the greatest source of soil microbial biodiversity and significantly changed microbial richness and community composition compared with other soils. Green manure also significantly enriched bacterial taxa involved in the soil nitrogen cycle (e.g. Microvirga sp., Pontibacter sp. and Nitrospira sp.). Our results showed that the diversity and composition of the microbial communities associated with biodynamic and organic farming systems were similar, indicating that the use of biodynamic preparations 500 and 501 did not cause any significant detectable changes to the soil microbial community in the short term, while the effects of green manure were significant in soil microbiota. The microbiological richness and structure of soil are used as a sensitive indicator of soil quality. The extension of organic/biodynamic farming, associated with green manure application, could contribute to increase the abundance of functional groups of biological and agronomical relevance and maintaining microbial biodiversity in vineyard soils. © 2017 The Society for Applied Microbiology.

  7. A potential non-invasive approach to evaluating blastocyst quality using biodynamic imaging

    NASA Astrophysics Data System (ADS)

    Li, Zhe; Ehmke, Natalie; Machaty, Zoltan; Nolte, David

    2018-02-01

    Biodynamic imaging (BDI) is capable of capturing the intracellular dynamics of blastocysts within a relatively short time. Spectroscopic signatures of embryos in the 0.01 Hz - 1 Hz range display responses to external factors before morphology changes take place. Viability evaluation is consistent with results from other non-invasive methods. Biodynamic imaging is a potential tool for selecting high quality embryos in clinical IVF practices.

  8. Biodynamic imaging of therapeutic efficacy for canine B-cell lymphoma: preclinical trial results

    NASA Astrophysics Data System (ADS)

    Choi, H.; Turek, J.; Li, Z.; Childress, M.; Nolte, D.

    2018-02-01

    Biodynamic imaging uses coherence-gated dynamic light scattering to create three dimensional maps of intracellular dynamics in living tissue biopsies. The technique is sensitive to changes in intracellular dynamics dependent on the mechanism of action (MoA) of therapeutics applied in vitro to the living samples. A preclinical trial in the assessment of chemotherapeutic response of dogs with B-cell lymphoma to the doxorubicin-based therapy CHOP has been completed using biodynamic imaging. The trial enrolled 19 canine patients presenting with non-Hodgkin's B-cell lymphoma. Biopsies were acquired through surgery or through needle cores. The time-varying power spectrum of scattered light after drugs are applied ex vivo to the biopsies represent biodynamic biomarkers that are used in machine learning algorithms to predict the patient clinical outcome. Two distinct phenotypes emerged from the analysis that correlate with patient drug resistance or sensitivity. Cross validation of the algorithms perform with an accuracy of 90% in the prediction of dogs that will respond to treatment. Biodynamic imaging has the potential to help select chemotherapy for personalized cancer care.

  9. Hand-transmitted vibration and biodynamic response of the human hand-arm: a critical review.

    PubMed

    Dong, R G; Rakheja, S; Schopper, A W; Han, B; Smutz, W P

    2001-01-01

    Hand-arm vibration syndrome (HAVS) has been associated with prolonged exposure to vibration transmitted to the human hand-arm system from hand-held power tools, vibrating machines, or hand-held vibrating workpieces. The biodynamic response of the human hand and arm to hand transmitted vibration (HTV) forms an essential basis for effective evaluations of exposures, vibration-attenuation mechanisms, and potential injury mechanisms. The biodynamic response to HTV and its relationship to HAVS are critically reviewed and discussed to highlight the advances and the need for further research. In view of its strong dependence on the nature of HTV and the lack of general agreement on the characteristics of HTV, the reported studies are first reviewed to enhance an understanding of HTV and related issues. The characteristics of HTV and relevant unresolved issues are discussed on the basis of measured data, proposed standards, and measurement methods, while the need for further developments in measurement systems is emphasized. The studies on biodynamic response and their findings are grouped into four categories based on the methodology used and the objective. These include studies on (1) through-the-hand-arm response, expressed in terms of vibration transmissibility; (2) to-the-hand response, expressed in terms of the force-motion relationship of the hand-arm system; (3) to-the-hand biodynamic response function, expressed in terms of vibration energy absorption; and (4) computer modeling of the biodynamic response characteristics.

  10. Biodynamic digital holography of chemoresistance in a pre-clinical trial of canine B-cell lymphoma.

    PubMed

    Choi, Honggu; Li, Zhe; Sun, Hao; Merrill, Dan; Turek, John; Childress, Michael; Nolte, David

    2018-05-01

    Biodynamic digital holography was used to obtain phenotypic profiles of canine non-Hodgkin B-cell lymphoma biopsies treated with standard-of-care chemotherapy. Biodynamic signatures from the living 3D tissues were extracted using fluctuation spectroscopy from intracellular Doppler light scattering in response to the molecular mechanisms of action of therapeutic drugs that modify a range of internal cellular motions. The standard-of-care to treat B-cell lymphoma in both humans and dogs is a combination CHOP therapy that consists of doxorubicin, prednisolone, cyclophosphamide and vincristine. The proportion of dogs experiencing durable cancer remission following CHOP chemotherapy was 68%, with 13 out of 19 dogs responding favorably to therapy and 6 dogs failing to have progression-free survival times greater than 100 days. Biodynamic signatures were found that correlate with inferior survival times, and biomarker selection was optimized to identify specific Doppler signatures related to chemoresistance. A machine learning classifier was constructed based on feature vector correlations and linear separability in high-dimensional feature space. Hold-out validation predicted patient response to therapy with 84% accuracy. These results point to the potential for biodynamic profiling to contribute to personalized medicine by aiding the selection of chemotherapy for cancer patients.

  11. Soil response to biodynamic farming practices in estevia -Stevia Rebaudiana- (Extremadura, Spain)

    NASA Astrophysics Data System (ADS)

    Labrador, Juana; Colmenares, Ricardo; Sánchez, Eduardo; Creus, Juan; García, Nieves; Blázquez, Jaime; Moreno, Marta M.

    2014-05-01

    The first results of the evolution of an organic-biodynamic cultivation of stevia (Stevia rebaudiana) in Extremadura (Spain) are shown here. The organic-biodynamic approach permits experimentally for a more holistic view of the crop development process what means the understanding and quantification of its evolution at different scales. The research methodology applied includes not only quantitative individual parameters of the crop development but also global parameters which make a contribution of very relevant information concerning unbalances between growth and differentiation processes, as well as other aspects linked to the product intrinsic quality. The crop cultivation has been done over a plot of 2.5 has, on acid soils (pH 5.18) and very poor organic matter content (0.5 %). On this first year of cultivation two cuts were given to the plant with an average total yield of 4,500 kg/ha without any supply of solid organic matter, only with the application of the biodynamic preparations. So far results regarding soil improvement and crop productivity, taking into consideration the practices used, let us introduce this pioneer crop in Extremadura, not only as an alternative crop to the current tobacco crop in this area, but also as a development resource for the rural environment of this region. Key words: Agroecology, Organic Biodynamic Agriculture, Stevia Rebaudiana

  12. Adaptive magnetorheological seat suspension for shock mitigation

    NASA Astrophysics Data System (ADS)

    Singh, Harinder Jit

    This research focuses on theoretical and experimental analysis of an adaptive seat suspension employing magnetorheological energy absorber with the objective of minimizing injury potential to seated occupant of different weights subjected to broader crash intensities. The research was segmented into three tasks: (1) development of magnetorheological energy absorber, (2) biodynamic modeling of a seated occupant, and (3) control schemes for shock mitigation. A linear stroking semi-active magnetorheological energy absorber (MREA) was designed, fabricated and tested for intense impact conditions with piston velocities up to 8 m/s. MREA design was optimized on the basis of Bingham-plastic model (BPM model) in order to maximize the energy absorption capabilities at high impact velocities. Computational fluid dynamics and magnetic FE analysis were conducted to validate MREA performance. Subsequently, low-speed cyclic testing (0-2 Hz subjected to 0-5.5 A) and high-speed drop testing (0-4.5 m/s at 0 A) were conducted for quantitative comparison with the numerical simulations. Later, a nonlinear four degrees-of-freedom biodynamic model representing a seated 50th percentile male occupant was developed on the basis of experiments conducted on Hybrid II 50th percentile male anthropomorphic test device. The response of proposed biodynamic model was compared quantitatively against two different biodynamic models from the literature that are heavily implemented for obtaining biodynamic response under impact conditions. The proposed biodynamic model accurately predicts peak magnitude, overall shape and the duration of the biodynamic transient response, with minimal phase shift. The biodynamic model was further validated against 16 impact tests conducted on horizontal accelerator facility at NAVAIR for two different shock intensities. Compliance effects of human body were also investigated on the performance of adaptive seat suspension by comparing the proposed biodynamic model response with that of a rigid body response. Finally, three different control schemes were analyzed for maximizing shock attenuation using semi-active magnetorheological energy absorber. High-speed drop experiments were conducted by dropping two rigid payloads of 240 and 340 lb mass from heights of 35 and 60 inch to simulate different impact intensities. First control scheme called constant stroking load control offered inflexible stroking load irrespective of varying impact severity or occupant weight. The other two control schemes: terminal trajectory control and optimal control adapted stroking load as per the shock intensity. The control schemes were compared on the basis of their adaptability and ease of implementation. These tools can serve as the basis for future research and development of state-of-the-art crashworthy seat suspension designs that further enhance occupant protection compared to limited performance of existing passive crashworthy concepts.

  13. Biodynamic modelling of the accumulation of Ag, Cd and Zn by the deposit-feeding polychaete Nereis diversicolor: inter-population variability and a generalised predictive model.

    PubMed

    Kalman, J; Smith, B D; Riba, I; Blasco, J; Rainbow, P S

    2010-06-01

    Biodynamic parameters of the ragworm Nereis diversicolor from southern Spain and south England were experimentally derived to assess the inter-population variability of physiological parameters of the bioaccumulation of Ag, Cd and Zn from water and sediment. Although there were some limited variations, these were not consistent with the local metal bioavailability nor with temperature changes. Incorporating the biodynamic parameters into a defined biodynamic model, confirmed that sediment is the predominant source of Cd and Zn accumulated by the worms, accounting in each case for 99% of the overall accumulated metals, whereas the contribution of dissolved Ag to the total accumulated by the worm increased from about 27 to about 53% with increasing dissolved Ag concentration. Standardised values of metal-specific parameters were chosen to generate a generalised model to be extended to N. diversicolor populations across a wide geographical range from western Europe to North Africa. According to the assumptions of this model, predicted steady state concentrations of Cd and Zn in N. diversicolor were overestimated, those of Ag underestimated, but still comparable to independent field measurements. We conclude that species-specific physiological metal bioaccumulation parameters are relatively constant over large geographical distances, and a single generalised biodynamic model does have potential to predict accumulated Ag, Cd and Zn concentrations in this polychaete from a single sediment metal concentration.

  14. Chemical Biodynamics Division. Annual report 1979

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

    Not Available

    1980-08-01

    The Chemical Biodynamics Division of LBL continues to conduct basic research on the dynamics of living cells and on the interaction of radiant energy with organic matter. Many aspects of this basic research are related to problems of environmental and health effects of fossil fuel combustion, solar energy conversion and chemical/ viral carcinogenesis.

  15. An Analysis of Vertebral Stress and BMD During +Gz Impact Accelerations

    DTIC Science & Technology

    2007-04-01

    Responses During Laboratory Frontal –Gx Axis Impact Tests. AFRL Technical Report AFRL-HE-WP-TR-2001-0022. 9) Buhrman, J.R., Plaga , J.A., Cheng, H...University of Munich. Naval Biodynamics Laboratory, New Orleans, LA. 4) Buhrman, J.R., Plaga , J.A., Cheng, H., Mosher, S.E. (2001) The AFRL Biodynamics

  16. (1)H NMR foodomics reveals that the biodynamic and the organic cultivation managements produce different grape berries (Vitis vinifera L. cv. Sangiovese).

    PubMed

    Picone, Gianfranco; Trimigno, Alessia; Tessarin, Paola; Donnini, Silvia; Rombolà, Adamo Domenico; Capozzi, Francesco

    2016-12-15

    The increasing demand for natural foods and beverages, i.e. prepared by excluding synthetic chemicals along the whole production chain, has boosted the adoption of organic and biodynamic cultivation methods which are based on protocols avoiding use of synthetic pesticides. This trend is striking in viticulture, since wine production is largely shaped by the varying drinking attitudes of environment-friendly consumers. Using (1)H NMR, the compositions of grape berries, collected at harvest in 2009 and 2011, in experimental plots cultivated either with biodynamic or organic methods, were compared. Although the analysis provides a comprehensive metabolic profile of berries, the resulting distinctive pattern consists of a few molecules. Lower content of sugars, coumaric and caffeic acids, as well as higher amount of γ-aminobutyric acid (GABA) were observed in biodynamic grapes. The (1)H NMR foodomics approach evidenced a diverse fruit metabolome that could be associated to a different physiological response of plants to the agronomic environment. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Expectation or Sensorial Reality? An Empirical Investigation of the Biodynamic Calendar for Wine Drinkers

    PubMed Central

    Parr, Wendy V.; Valentin, Dominique; Reedman, Phil; Grose, Claire; Green, James A.

    2017-01-01

    The study’s aim was to investigate a central tenet of biodynamic philosophy as applied to wine tasting, namely that wines taste different in systematic ways on days determined by the lunar cycle. Nineteen New Zealand wine professionals tasted blind 12 Pinot noir wines at times determined within the biodynamic calendar for wine drinkers as being favourable (Fruit day) and unfavourable (Root day) for wine tasting. Tasters rated each wine four times, twice on a Fruit day and twice on a Root day, using 20 experimenter-provided descriptors. Wine descriptors spanned a range of varietal-relevant aroma, taste, and mouthfeel characteristics, and were selected with the aim of elucidating both qualitative and quantitative aspects of each wine’s perceived aromatic, taste, and structural aspects including overall wine quality and liking. A post-experimental questionnaire was completed by each participant to determine their degree of knowledge about the purpose of the study, and their awareness of the existence of the biodynamic wine drinkers’ calendar. Basic wine physico-chemical parameters were determined for the wines tasted on each of a Fruit day and a Root day. Results demonstrated that the wines were judged differentially on all attributes measured although type of day as determined by the biodynamic calendar for wine drinkers did not influence systematically any of the wine characteristics evaluated. The findings highlight the importance of testing experimentally practices that are based on anecdotal evidence but that lend themselves to empirical investigation. PMID:28046047

  18. Expectation or Sensorial Reality? An Empirical Investigation of the Biodynamic Calendar for Wine Drinkers.

    PubMed

    Parr, Wendy V; Valentin, Dominique; Reedman, Phil; Grose, Claire; Green, James A

    2017-01-01

    The study's aim was to investigate a central tenet of biodynamic philosophy as applied to wine tasting, namely that wines taste different in systematic ways on days determined by the lunar cycle. Nineteen New Zealand wine professionals tasted blind 12 Pinot noir wines at times determined within the biodynamic calendar for wine drinkers as being favourable (Fruit day) and unfavourable (Root day) for wine tasting. Tasters rated each wine four times, twice on a Fruit day and twice on a Root day, using 20 experimenter-provided descriptors. Wine descriptors spanned a range of varietal-relevant aroma, taste, and mouthfeel characteristics, and were selected with the aim of elucidating both qualitative and quantitative aspects of each wine's perceived aromatic, taste, and structural aspects including overall wine quality and liking. A post-experimental questionnaire was completed by each participant to determine their degree of knowledge about the purpose of the study, and their awareness of the existence of the biodynamic wine drinkers' calendar. Basic wine physico-chemical parameters were determined for the wines tasted on each of a Fruit day and a Root day. Results demonstrated that the wines were judged differentially on all attributes measured although type of day as determined by the biodynamic calendar for wine drinkers did not influence systematically any of the wine characteristics evaluated. The findings highlight the importance of testing experimentally practices that are based on anecdotal evidence but that lend themselves to empirical investigation.

  19. Multi-stimuli-responsive biohybrid nanoparticles with cross-linked albumin coronae self-assembled by a polymer-protein biodynamer.

    PubMed

    Wang, Lin; Liu, Li; Dong, Bingyang; Zhao, Hanying; Zhang, Mingming; Chen, Wenjuan; Hong, Yanhang

    2017-05-01

    A thermoresponsive polymer-protein biodynamer was prepared via the bioconjugation of an aliphatic aldehyde-functionalized copolymer to hydrazine-modified bovine serum albumin (BSA) through reversible pyridylhydrazone linkages. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and size exclusion chromatography (SEC) results indicated that the pyridylhydrazone linkages cleaved in an intracellular-mimicking acidic milieu, thus leading to the release of BSA. The dynamic character of the protein biodynamer was demonstrated by exchange reactions with aldehyde-containing molecules. The biodynamer self-assembled into spherical micelles at a temperature above its lower critical solution temperature (LCST). Subsequently, BSA molecules within the hydrophilic coronae of the micelles were readily cross-linked via reaction with cystamine at 45°C, and multi-stimuli-responsive nanoparticles were generated. The biohybrid nanoparticles reversibly swelled and shrank as the cores of the nanoparticles were solvated below the LCST and desolvated above the LCST. The accessible reversibility of the pyridylhydrazone bonds imparts pH-responsive and dynamic characteristics to the nanoparticles. The nanoparticles displayed glutathione (GSH) responsiveness, and the synergistic effects of pH and GSH resulted in complete disintegration of the nanoparticles under the intracellular-mimicking acidic and reductive conditions. The nanoparticles were also enzyme-responsive and disintegrated rapidly in the presence of protease. In vitro cytotoxicity and cell uptake assays demonstrated that the nanoparticles were highly biocompatible and effectively internalized by HepG2 cells, which make them interesting candidates as vehicles for drug delivery application and biomimetic platforms to investigate the biological process in nature. In this research, we report the synthesis of a temperature and pH dual-responsive polymer-protein biodynamer through reversible pyridylhydrazone formation. The prepared biodynamer can offer a potential platform for intracellular protein delivery. The multi-stimuli-responsive biohybrid nanoparticles containing disulfide functionalities are constructed by cross-linking albumin coronae of the biodynamer micelles. With the combination of a thermoresponsive polymer, protein and reversible covalent bonds, the biohybrid nanoparticles are endowed with highly biocompatible, environmentally responsive and adaptive features. These nanoparticles present the ability to undergo changes in their constitution, hydrodynamic size and nanostructure in response to physical, chemical and biological stimuli, which make them interesting candidates as vehicles for drug delivery application and a biomimetic platform to investigate the biological process in nature. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  20. A method to quantify hand-transmitted vibration exposure based on the biodynamic stress concept.

    PubMed

    Dong, R G; Welcome, D E; Wu, J Z

    2007-11-01

    This study generally hypothesized that the vibration-induced biodynamic stress and number of its cycles in a substructure of the hand-arm system play an important role in the development of vibration-induced disorders in the substructure. As the first step to test this hypothesis, the specific aims of this study were to develop a practical method to quantify the biodynamic stress-cycle measure, to compare it with ISO-weighted and unweighted accelerations, and to assess its potential for applications. A mechanical-equivalent model of the system was established using reported experimental data. The model was used to estimate the average stresses in the fingers and palm. The frequency weightings of the stresses in these substructures were derived using the proposed stress-cycle measure. This study found the frequency dependence of the average stress distributed in the fingers is different from that in the palm. Therefore, this study predicted that the frequency dependencies of finger disorders could also be different from those of the disorders in the palm, wrist, and arms. If vibration-induced white finger (VWF) is correlated better with unweighted acceleration than with ISO-weighted acceleration, the biodynamic stress distributed in the fingers is likely to play a more important role in the development of VWF than is th e biodynamic stressdistributed in the other substructures of the hand-arm system. The results of this study also suggest that the ISO weighting underestimates the high-frequency effect on the finger disorder development but it may provide a reasonable risk assessment of the disorders in the wrist and arm.

  1. Establishing the Biodynamics Data Resource (BDR): Human Volunteer Impact Acceleration Research Data in the BDR

    DTIC Science & Technology

    2009-10-01

    accelerations (+Z) were applied to HRVs in the supine position to mimic the acceleration of an ejection seat , while runs simulating aircraft crashes were...Naval Biodynamics Laboratory, 1985). The vertical testing provided a more authentic ejection seat simulation than was achievable using axial...impact acceleration exposures with hundreds of human research volunteers. The resulting volumes of kinematic and physiological data serve as a

  2. Naval Biodynamics Laboratory: 1989 and 1990 Command History

    DTIC Science & Technology

    1991-07-01

    T. G., "Naval Biodynamics Laboratory: Human Factors Research Capabilities and Programs." Presented at the Canal de Experiencias Hidrodinamicas de El...1990. Call, D. W., attended meetings at the Canal de Experiencias Hidrodinamicas de El Padro, Madrid, Spain, 24-26 April 1990. Call, D. W., attended the...LABORATORY Dobie, T. G., attended meetings at the Canal de Experiencias Hidrodinamicas de El Padro, Madrid, Spain, 24-26 April 1990. Dobie, T. G., attended

  3. Experimental investigation of biodynamic human body models subjected to whole-body vibration during a vehicle ride.

    PubMed

    Taskin, Yener; Hacioglu, Yuksel; Ortes, Faruk; Karabulut, Derya; Arslan, Yunus Ziya

    2018-02-06

    In this study, responses of biodynamic human body models to whole-body vibration during a vehicle ride were investigated. Accelerations were acquired from three different body parts, such as the head, upper torso and lower torso, of 10 seated passengers during a car ride while two different road conditions were considered. The same multipurpose vehicle was used during all experiments. Additionally, by two widely used biodynamic models in the literature, a set of simulations were run to obtain theoretical accelerations of the models and were compared with those obtained experimentally. To sustain a quantified comparison between experimental and theoretical approaches, the root mean square acceleration and acceleration spectral density were calculated. Time and frequency responses of the models demonstrated that neither of the models showed the best prediction performance of the human body behaviour in all cases, indicating that further models are required for better prediction of the human body responses.

  4. A biodynamic feedthrough model based on neuromuscular principles.

    PubMed

    Venrooij, Joost; Abbink, David A; Mulder, Mark; van Paassen, Marinus M; Mulder, Max; van der Helm, Frans C T; Bulthoff, Heinrich H

    2014-07-01

    A biodynamic feedthrough (BDFT) model is proposed that describes how vehicle accelerations feed through the human body, causing involuntary limb motions and so involuntary control inputs. BDFT dynamics strongly depend on limb dynamics, which can vary between persons (between-subject variability), but also within one person over time, e.g., due to the control task performed (within-subject variability). The proposed BDFT model is based on physical neuromuscular principles and is derived from an established admittance model-describing limb dynamics-which was extended to include control device dynamics and account for acceleration effects. The resulting BDFT model serves primarily the purpose of increasing the understanding of the relationship between neuromuscular admittance and biodynamic feedthrough. An added advantage of the proposed model is that its parameters can be estimated using a two-stage approach, making the parameter estimation more robust, as the procedure is largely based on the well documented procedure required for the admittance model. To estimate the parameter values of the BDFT model, data are used from an experiment in which both neuromuscular admittance and biodynamic feedthrough are measured. The quality of the BDFT model is evaluated in the frequency and time domain. Results provide strong evidence that the BDFT model and the proposed method of parameter estimation put forward in this paper allows for accurate BDFT modeling across different subjects (accounting for between-subject variability) and across control tasks (accounting for within-subject variability).

  5. SU-E-J-31: Biodynamic Imaging of Cancer Tissue and Response to Chemotherapy

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

    Nolte, D; Turek, J; Childress, M

    2014-06-01

    Purpose: To measure intracellular motions inside three-dimensional living cancer tissue samples to establish a novel set of biodynamic biomarkers that assess tissue proliferative activity and sensitivity or resistance to chemotherapy. Methods: Biodynamic imaging (BDI) uses digital holography with low-coherence low-intensity light illumination to construct 3D holograms from depths up to a millimeter deep inside cancer tissue models that include multicellular tumor spheroids and ex vivo cancer biopsies from canine non-Hodgkins lymphoma and epithelial ovarian cancer (EOC) mouse explants. Intracellular motions modulate the holographic intensity with frequencies related to the Doppler effect caused by the motions of a wide variety ofmore » intracellular components. These motions are affected by applied therapeutic agents, and BDI produces unique fingerprints of the action of specific drugs on the motions in specific cell types. In this study, chemotherapeutic agents (doxorubicin for canine lymphoma and oxoplatin for ovarian) are applied to the living tissue models and monitored over 10 hours by BDI. Results: Multicellular spheroids and patient biopsies are categorized as either sensitive or insensitive to applied therapeutics depending on the intracellular Doppler signatures of chemotherapy response. For both lymphoma and EOC there is strong specificity to the two types of sensitivities, with sensitive cell lines and biopsies exhibiting a global cessation of proliferation and strong suppression of metabolic activity, while insensitive cell lines and biopsies show moderate activation of Doppler frequencies associated with membrane processes and possible membrane trafficking. Conclusion: This work supports the hypothesis that biodynamic biomarkers from three-dimensional living tumor tissue, that includes tissue heterogeneity and measured within 24 hours of surgery, is predictive of near-term patient response to therapy. Future work will correlate biodynamic biomarkers with progression free survival times. This work is supported by NIH 1R01EB016582 and NSF 1263753-CBET. Nolte, Turek and An have a financial interest in Animated Dynamics, Inc. that will be licensing technology from Purdue University.« less

  6. Biodynamics of deformable human body motion

    NASA Technical Reports Server (NTRS)

    Strauss, A. M.; Huston, R. L.

    1976-01-01

    The objective is to construct a framework wherein the various models of human biomaterials fit in order to describe the biodynamic response of the human body. The behavior of the human body in various situations, from low frequency, low amplitude vibrations to impact loadings in automobile and aircraft crashes, is very complicated with respect to all aspects of the problem: materials, geometry and dynamics. The materials problem is the primary concern, but the materials problem is intimately connected with geometry and dynamics.

  7. Biodynamic profiling of three-dimensional tissue growth techniques

    NASA Astrophysics Data System (ADS)

    Sun, Hao; Merrill, Dan; Turek, John; Nolte, David

    2016-03-01

    Three-dimensional tissue culture presents a more biologically relevant environment in which to perform drug development than conventional two-dimensional cell culture. However, obtaining high-content information from inside three dimensional tissue has presented an obstacle to rapid adoption of 3D tissue culture for pharmaceutical applications. Biodynamic imaging is a high-content three-dimensional optical imaging technology based on low-coherence interferometry and digital holography that uses intracellular dynamics as high-content image contrast. In this paper, we use biodynamic imaging to compare pharmaceutical responses to Taxol of three-dimensional multicellular spheroids grown by three different growth techniques: rotating bioreactor, hanging-drop and plate-grown spheroids. The three growth techniques have systematic variations among tissue cohesiveness and intracellular activity and consequently display different pharmacodynamics under identical drug dose conditions. The in vitro tissue cultures are also compared to ex vivo living biopsies. These results demonstrate that three-dimensional tissue cultures are not equivalent, and that drug-response studies must take into account the growth method.

  8. Frequency weightings based on biodynamics of fingers-hand-arm system.

    PubMed

    Dong, Ren G; Welcome, Daniel E; Wu, John Z

    2005-07-01

    The frequency weighting for assessing hand-transmitted vibration exposure is critical to obtaining a true dose-response relationship. Any valid weighting must have a solid theoretical foundation. The objectives of this study are to examine the biodynamic foundation for assessing the vibration exposure and to develop a set of biodynamic methods to formulate the frequency weightings for different anatomical locations of the fingers-hand-arm system. The vibration transmissibility measured on the fingers, hand, wrist, elbow, shoulder, and head was used to define the transmitted acceleration-based (TAB) frequency weighting. The apparent masses measured at the fingers and the palm of the hand were used to construct the biodynamic force-based (BFB) weightings. These weightings were compared with the ISO weighting specified in ISO 5349-1 (2001). The results of this study suggest that the frequency weightings for the vibration-induced problems at different anatomical locations of the hand-arm system can be basically divided into three groups: (a) the weighting for the fingers and hand, (b) the weighting for the wrist, elbow, and shoulder, and (c) the weighting for the head. The ISO weighting is highly correlated with the weighting for the second group but not with the first and third groups. The TAB and BFB finger weightings are quite different at frequencies lower than 100 Hz, but they show similar trends at higher frequencies. Both TAB and BFB finger weightings at frequencies higher than 20 Hz are greater than the ISO weighting.

  9. Review and Evaluation of Hand-Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces.

    PubMed

    Dong, Ren G; Sinsel, Erik W; Welcome, Daniel E; Warren, Christopher; Xu, Xueyan S; McDowell, Thomas W; Wu, John Z

    2015-09-01

    The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study.

  10. Review and Evaluation of Hand–Arm Coordinate Systems for Measuring Vibration Exposure, Biodynamic Responses, and Hand Forces

    PubMed Central

    Dong, Ren G.; Sinsel, Erik W.; Welcome, Daniel E.; Warren, Christopher; Xu, Xueyan S.; McDowell, Thomas W.; Wu, John Z.

    2015-01-01

    The hand coordinate systems for measuring vibration exposures and biodynamic responses have been standardized, but they are not actually used in many studies. This contradicts the purpose of the standardization. The objectives of this study were to identify the major sources of this problem, and to help define or identify better coordinate systems for the standardization. This study systematically reviewed the principles and definition methods, and evaluated typical hand coordinate systems. This study confirms that, as accelerometers remain the major technology for vibration measurement, it is reasonable to standardize two types of coordinate systems: a tool-based basicentric (BC) system and an anatomically based biodynamic (BD) system. However, these coordinate systems are not well defined in the current standard. Definition of the standard BC system is confusing, and it can be interpreted differently; as a result, it has been inconsistently applied in various standards and studies. The standard hand BD system is defined using the orientation of the third metacarpal bone. It is neither convenient nor defined based on important biological or biodynamic features. This explains why it is rarely used in practice. To resolve these inconsistencies and deficiencies, we proposed a revised method for defining the realistic handle BC system and an alternative method for defining the hand BD system. A fingertip-based BD system for measuring the principal grip force is also proposed based on an important feature of the grip force confirmed in this study. PMID:26929824

  11. Why is metal bioaccumulation so variable? Biodynamics as a unifying concept

    USGS Publications Warehouse

    Luoma, Samuel N.; Rainbow, Philip S.

    2005-01-01

    Ecological risks from metal contaminants are difficult to document because responses differ among species, threats differ among metals, and environmental influences are complex. Unifying concepts are needed to better tie together such complexities. Here we suggest that a biologically based conceptualization, the biodynamic model, provides the necessary unification for a key aspect in risk:  metal bioaccumulation (internal exposure). The model is mechanistically based, but empirically considers geochemical influences, biological differences, and differences among metals. Forecasts from the model agree closely with observations from nature, validating its basic assumptions. The biodynamic metal bioaccumulation model combines targeted, high-quality geochemical analyses from a site of interest with parametrization of key physiological constants for a species from that site. The physiological parameters include metal influx rates from water, influx rates from food, rate constants of loss, and growth rates (when high). We compiled results from 15 publications that forecast species-specific bioaccumulation, and compare the forecasts to bioaccumulation data from the field. These data consider concentrations that cover 7 orders of magnitude. They include 7 metals and 14 species of animals from 3 phyla and 11 marine, estuarine, and freshwater environments. The coefficient of determination (R2) between forecasts and independently observed bioaccumulation from the field was 0.98. Most forecasts agreed with observations within 2-fold. The agreement suggests that the basic assumptions of the biodynamic model are tenable. A unified explanation of metal bioaccumulation sets the stage for a realistic understanding of toxicity and ecological effects of metals in nature.

  12. The apparent mass and mechanical impedance of the hand and the transmission of vibration to the fingers, hand, and arm

    NASA Astrophysics Data System (ADS)

    Concettoni, Enrico; Griffin, Michael

    2009-08-01

    Although hand-transmitted vibration causes injury and disease, most often evident in the fingers, the biodynamic responses of the fingers, hand, and arm are not yet well understood. A method of investigating the motion of the entire finger-hand-arm system, based on the simultaneous measurement of the biodynamic response at the driving point and the transmissibility to many points on the finger-hand-arm system, is illustrated. Fourteen male subjects participated in an experiment in which they pushed down on a vertically vibrating metal plate with their right forearm pronated and their elbow bent at 90°. The apparent mass and mechanical impedance of the finger-hand-arm system were measured for each of seven different contact conditions between the plate and the fingers and hand. Simultaneously, the vibration of the fingers, hand, and arm was measured at 41 locations using a scanning laser Doppler vibrometer. Transmissibilities showed how the vibration was transmitted along the arm and allowed the construction of spectral operating deflection shapes showing the vibration pattern of the fingers, hand, and arm for each of the seven contact conditions. The vibration patterns at critical frequencies for each contact condition have been used to explain features in the driving point biodynamic responses and the vibration behaviour of the hand-arm system. Spectral operating deflection shapes for the upper limb assist the interpretation of driving point biodynamic responses and help to advance understanding required to predict, explain, and control the various effects of hand-transmitted vibration.

  13. Chemical and sensory characterisation of Sangiovese red wines: comparison between biodynamic and organic management.

    PubMed

    Parpinello, Giuseppina Paola; Rombolà, Adamo Domenico; Simoni, Marco; Versari, Andrea

    2015-01-15

    The effects of biodynamic production practices on composition and sensory attributes of Sangiovese wines were examined for 2 years (2009 and 2010) in a vineyard that was converted from organic (ORG) to biodynamic (BDN) viticulture. During the first year (2009), the BDN wines were characterised by low alcohol strength, colour intensity, total polyphenols, monomeric anthocyanins and catechin. Conversely, the second year BDN wines differed from the organic wines in terms of total polyphenols and phenolic compounds, including polymeric pigments, co-pigmentation, tannins and iron-reactive polyphenols. The effect of management practices, harvest and their interaction was analysed for each compound. Positive interaction was observed for total acidity, volatile acidity, cyanidin-3-glucoside, protocatechuic acid, (+)-catechin, quercetin and trans-resveratrol. ORG wine initially showed a more complex aroma profile; however, the differences were almost indistinguishable during the second year. Trained panellists highlighted differences in colour intensity between ORG and BDN wines although no preference was found by consumers. The concentrations of ochratoxin A and biogenic amines were far below the health-hazardous threshold. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Are Epiphytic Microbial Communities in the Carposphere of Ripening Grape Clusters (Vitis vinifera L.) Different between Conventional, Organic, and Biodynamic Grapes?

    PubMed

    Kecskeméti, Elizabeth; Berkelmann-Löhnertz, Beate; Reineke, Annette

    2016-01-01

    Using barcoded pyrosequencing fungal and bacterial communities associated with grape berry clusters (Vitis vinifera L.) obtained from conventional, organic and biodynamic vineyard plots were investigated in two subsequent years at different stages during berry ripening. The four most abundant operational taxonomic units (OTUs) based on fungal ITS data were Botrytis cinerea, Cladosporium spp., Aureobasidium pullulans and Alternaria alternata which represented 57% and 47% of the total reads in 2010 and 2011, respectively. Members of the genera Sphingomonas, Gluconobacter, Pseudomonas, Erwinia, and Massilia constituted 67% of the total number of bacterial 16S DNA reads in 2010 samples and 78% in 2011 samples. Viticultural management system had no significant effect on abundance of fungi or bacteria in both years and at all three sampling dates. Exceptions were A. alternata and Pseudomonas spp. which were more abundant in the carposphere of conventional compared to biodynamic berries, as well as Sphingomonas spp. which was significantly less abundant on conventional compared to organic berries at an early ripening stage in 2011. In general, there were no significant differences in fungal and bacterial diversity indices or richness evident between management systems. No distinct fungal or bacterial communities were associated with the different maturation stages or management systems, respectively. An exception was the last stage of berry maturation in 2011, where the Simpson diversity index was significantly higher for fungal communities on biodynamic compared to conventional grapes. Our study highlights the existence of complex and dynamic microbial communities in the grape cluster carposphere including both phytopathogenic and potentially antagonistic microorganisms that can have a significant impact on grape production. Such knowledge is particularly relevant for development, selection and application of effective control measures against economically important pathogens present in the grape carposphere.

  15. Are Epiphytic Microbial Communities in the Carposphere of Ripening Grape Clusters (Vitis vinifera L.) Different between Conventional, Organic, and Biodynamic Grapes?

    PubMed Central

    Kecskeméti, Elizabeth; Berkelmann-Löhnertz, Beate; Reineke, Annette

    2016-01-01

    Using barcoded pyrosequencing fungal and bacterial communities associated with grape berry clusters (Vitis vinifera L.) obtained from conventional, organic and biodynamic vineyard plots were investigated in two subsequent years at different stages during berry ripening. The four most abundant operational taxonomic units (OTUs) based on fungal ITS data were Botrytis cinerea, Cladosporium spp., Aureobasidium pullulans and Alternaria alternata which represented 57% and 47% of the total reads in 2010 and 2011, respectively. Members of the genera Sphingomonas, Gluconobacter, Pseudomonas, Erwinia, and Massilia constituted 67% of the total number of bacterial 16S DNA reads in 2010 samples and 78% in 2011 samples. Viticultural management system had no significant effect on abundance of fungi or bacteria in both years and at all three sampling dates. Exceptions were A. alternata and Pseudomonas spp. which were more abundant in the carposphere of conventional compared to biodynamic berries, as well as Sphingomonas spp. which was significantly less abundant on conventional compared to organic berries at an early ripening stage in 2011. In general, there were no significant differences in fungal and bacterial diversity indices or richness evident between management systems. No distinct fungal or bacterial communities were associated with the different maturation stages or management systems, respectively. An exception was the last stage of berry maturation in 2011, where the Simpson diversity index was significantly higher for fungal communities on biodynamic compared to conventional grapes. Our study highlights the existence of complex and dynamic microbial communities in the grape cluster carposphere including both phytopathogenic and potentially antagonistic microorganisms that can have a significant impact on grape production. Such knowledge is particularly relevant for development, selection and application of effective control measures against economically important pathogens present in the grape carposphere. PMID:27500633

  16. Common-path biodynamic imaging for dynamic fluctuation spectroscopy of 3D living tissue

    NASA Astrophysics Data System (ADS)

    Li, Zhe; Turek, John; Nolte, David D.

    2017-03-01

    Biodynamic imaging is a novel 3D optical imaging technology based on short-coherence digital holography that measures intracellular motions of cells inside their natural microenvironments. Here both common-path and Mach-Zehnder designs are presented. Biological tissues such as tumor spheroids and ex vivo biopsies are used as targets, and backscattered light is collected as signal. Drugs are applied to samples, and their effects are evaluated by identifying biomarkers that capture intracellular dynamics from the reconstructed holograms. Through digital holography and coherence gating, information from different depths of the samples can be extracted, enabling the deep-tissue measurement of the responses to drugs.

  17. Biodynamic feedback training to assure learning partial load bearing on forearm crutches.

    PubMed

    Krause, Daniel; Wünnemann, Martin; Erlmann, Andre; Hölzchen, Timo; Mull, Melanie; Olivier, Norbert; Jöllenbeck, Thomas

    2007-07-01

    To examine how biodynamic feedback training affects the learning of prescribed partial load bearing (200N). Three pre-post experiments. Biomechanics laboratory in a German university. A volunteer sample of 98 uninjured subjects who had not used crutches recently. There were 24 subjects in experiment 1 (mean age, 23.2y); 64 in experiment 2 (mean age, 43.6y); and 10 in experiment 3 (mean age, 40.3y), parallelized by arm force. Video instruction and feedback training: In experiment 1, 2 varied instruction videos and reduced feedback frequency; in experiment 2, varied frequencies of changing tasks (contextual interference); and in experiment 3, feedback training (walking) and transfer (stair tasks). Vertical ground reaction force. Absolute error of practiced tasks was significantly reduced for all samples (P<.050). Varied contextual interference conditions did not significantly affect retention (P=.798) or transfer (P=.897). Positive transfer between tasks was significant in experiment 2 (P<.001) and was contrary to findings in experiment 3 (P=.071). Biodynamic feedback training is applicable for learning prescribed partial load bearing. The frequency of changing tasks is irrelevant. Despite some support for transfer effects, additional practice in climbing and descending stairs might be beneficial.

  18. On 4-degree-of-freedom biodynamic models of seated occupants: Lumped-parameter modeling

    NASA Astrophysics Data System (ADS)

    Bai, Xian-Xu; Xu, Shi-Xu; Cheng, Wei; Qian, Li-Jun

    2017-08-01

    It is useful to develop an effective biodynamic model of seated human occupants to help understand the human vibration exposure to transportation vehicle vibrations and to help design and improve the anti-vibration devices and/or test dummies. This study proposed and demonstrated a methodology for systematically identifying the best configuration or structure of a 4-degree-of-freedom (4DOF) human vibration model and for its parameter identification. First, an equivalent simplification expression for the models was made. Second, all of the possible 23 structural configurations of the models were identified. Third, each of them was calibrated using the frequency response functions recommended in a biodynamic standard. An improved version of non-dominated sorting genetic algorithm (NSGA-II) based on Pareto optimization principle was used to determine the model parameters. Finally, a model evaluation criterion proposed in this study was used to assess the models and to identify the best one, which was based on both the goodness of curve fits and comprehensive goodness of the fits. The identified top configurations were better than those reported in the literature. This methodology may also be extended and used to develop the models with other DOFs.

  19. A framework for biodynamic feedthrough analysis--part I: theoretical foundations.

    PubMed

    Venrooij, Joost; van Paassen, Marinus M; Mulder, Mark; Abbink, David A; Mulder, Max; van der Helm, Frans C T; Bulthoff, Heinrich H

    2014-09-01

    Biodynamic feedthrough (BDFT) is a complex phenomenon, which has been studied for several decades. However, there is little consensus on how to approach the BDFT problem in terms of definitions, nomenclature, and mathematical descriptions. In this paper, a framework for biodynamic feedthrough analysis is presented. The goal of this framework is two-fold. First, it provides some common ground between the seemingly large range of different approaches existing in the BDFT literature. Second, the framework itself allows for gaining new insights into BDFT phenomena. It will be shown how relevant signals can be obtained from measurement, how different BDFT dynamics can be derived from them, and how these different dynamics are related. Using the framework, BDFT can be dissected into several dynamical relationships, each relevant in understanding BDFT phenomena in more detail. The presentation of the BDFT framework is divided into two parts. This paper, Part I, addresses the theoretical foundations of the framework. Part II, which is also published in this issue, addresses the validation of the framework. The work is presented in two separate papers to allow for a detailed discussion of both the framework's theoretical background and its validation.

  20. Suppression of Biodynamic Interference by Adaptive Filtering

    NASA Technical Reports Server (NTRS)

    Velger, M.; Merhav, S. J.; Grunwald, A. J.

    1984-01-01

    Preliminary experimental results obtained in moving base simulator tests are presented. Both for pursuit and compensatory tracking tasks, a strong deterioration in tracking performance due to biodynamic interference is found. The use of adaptive filtering is shown to substantially alleviate these effects, resulting in a markedly improved tracking performance and reduction in task difficulty. The effect of simulator motion and of adaptive filtering on human operator describing functions is investigated. Adaptive filtering is found to substantially increase pilot gain and cross-over frequency, implying a more tight tracking behavior. The adaptive filter is found to be effective in particular for high-gain proportional dynamics, low display forcing function power and for pursuit tracking task configurations.

  1. Ernst Haeckel's biodynamics 1866 and the occult basis of organic farming

    PubMed Central

    Kutschera, Ulrich

    2016-01-01

    ABSTRACT One hundred and 50 years ago (Sept. 1866), Ernst Haeckel published a monograph entitled General Morphology of Organisms, wherein key terms, such as Protista, Monera, ontogeny, phylogeny, ecology and the ‘biogenetic law’ where introduced. In addition, Haeckel coined the word “biodynamics” as a synonym for “general physiology.” In contrast, Rudolf Steiner's “biodynamic agriculture,” which originated in 1924, and was promoted via Ehrenfried Pfeiffer's book of 1938 with the same title, is an occult pseudoscience still popular today. The misuse of Haeckel's term to legitimize disproven homeopathic principles and esoteric rules within the context of applied plant research is unacceptable. PMID:27322020

  2. Modal description—A better way of characterizing human vibration behavior

    NASA Astrophysics Data System (ADS)

    Rützel, Sebastian; Hinz, Barbara; Wölfel, Horst Peter

    2006-12-01

    Biodynamic responses to whole body vibrations are usually characterized in terms of transfer functions, such as impedance or apparent mass. Data measurements from subjects are averaged and analyzed with respect to certain attributes (anthropometrics, posture, excitation intensity, etc.). Averaging involves the risk of identifying unnatural vibration characteristics. The use of a modal description as an alternative method is presented and its contribution to biodynamic modelling is discussed. Modal description is not limited to just one biodynamic function: The method holds for all transfer functions. This is shown in terms of the apparent mass and the seat-to-head transfer function. The advantages of modal description are illustrated using apparent mass data of six male individuals of the same mass percentile. From experimental data, modal parameters such as natural frequencies, damping ratios and modal masses are identified which can easily be used to set up a mathematical model. Following the phenomenological approach, this model will provide the global vibration behavior relating to the input data. The modal description could be used for the development of hardware vibration dummies. With respect to software models such as finite element models, the validation process for these models can be supported by the modal approach. Modal parameters of computational models and of the experimental data can establish a basis for comparison.

  3. The relationships between hand coupling force and vibration biodynamic responses of the hand-arm system.

    PubMed

    Pan, Daniel; Xu, Xueyan S; Welcome, Daniel E; McDowell, Thomas W; Warren, Christopher; Wu, John; Dong, Ren G

    2018-06-01

    This study conducted two series of experiments to investigate the relationships between hand coupling force and biodynamic responses of the hand-arm system. In the first experiment, the vibration transmissibility on the system was measured as a continuous function of grip force while the hand was subjected to discrete sinusoidal excitations. In the second experiment, the biodynamic responses of the system subjected to a broadband random vibration were measured under five levels of grip forces and a combination of grip and push forces. This study found that the transmissibility at each given frequency increased with the increase in the grip force before reaching a maximum level. The transmissibility then tended to plateau or decrease when the grip force was further increased. This threshold force increased with an increase in the vibration frequency. These relationships remained the same for both types of vibrations. The implications of the experimental results are discussed. Practitioner Summary: Shocks and vibrations transmitted to the hand-arm system may cause injuries and disorders of the system. How to take hand coupling force into account in the risk assessment of vibration exposure remains an important issue for further studies. This study is designed and conducted to help resolve this issue.

  4. Human body modeling method to simulate the biodynamic characteristics of spine in vivo with different sitting postures.

    PubMed

    Dong, Rui-Chun; Guo, Li-Xin

    2017-11-01

    The aim of this study is to model the computational model of seated whole human body including skeleton, muscle, viscera, ligament, intervertebral disc, and skin to predict effect of the factors (sitting postures, muscle and skin, buttocks, viscera, arms, gravity, and boundary conditions) on the biodynamic characteristics of spine. Two finite element models of seated whole body and a large number of finite element models of different ligamentous motion segments were developed and validated. Static, modal, and transient dynamic analyses were performed. The predicted vertical resonant frequency of seated body model was in the range of vertical natural frequency of 4 to 7 Hz. Muscle, buttocks, viscera, and the boundary conditions of buttocks have influence on the vertical resonant frequency of spine. Muscle played a very important role in biodynamic response of spine. Compared with the vertical posture, the posture of lean forward or backward led to an increase in stress on anterior or lateral posterior of lumbar intervertebral discs. This indicated that keeping correct posture could reduce the injury of vibration on lumbar intervertebral disc under whole-body vibration. The driving posture not only reduced the load of spine but also increased the resonant frequency of spine. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Twentieth Annual Conference on Manual Control, Volume 1

    NASA Technical Reports Server (NTRS)

    Hart, S. G. (Compiler); Hartzell, E. J. (Compiler)

    1984-01-01

    The 48 papers presented were devoted to humanopeator modeling, application of models to simulation and operational environments, aircraft handling qualities, teleopertors, fault diagnosis, and biodynamics.

  6. Role of Prolactin in the Regulation of Bicarbonates Biodynamics in Female Rat Model of Cholestasis of Pregnancy.

    PubMed

    Bulaeva, O A; Abramicheva, P A; Balakina, T A; Smirnova, O V

    2017-03-01

    We studied possible involvement of prolactin in the regulation of bicarbonate biodynamics using female rat model of cholestasis of pregnancy induced by transplantation of the donor pituitary under the renal capsule of a recipient (hyperprolactinemia) and bile duct ligation (cholestasis). The concentration of bicarbonates in the bile and blood, their excretion, clearance, and reabsorption, as well as glomerular filtration rate and excretion of sodium ions were assessed. It was found that the main effect of prolactin was directed to the kidney-regulated pool of bicarbonates and consisted in stimulation of their clearance and inhibition of reabsorption, which led to a decrease in bicarbonate blood concentration. Parallel influence of prolactin on the clearance of bicarbonates and sodium ions was observed.

  7. Seated Occupant Apparent Mass Characteristics Under Automotive Postures and Vertical Vibration

    NASA Astrophysics Data System (ADS)

    RAKHEJA, S.; HARU, I.; BOILEAU, P.-É.

    2002-05-01

    The biodynamic apparent mass response characteristics of 24 human subjects (12 males and 12 females) seated under representative automotive postures with hands-in-lap (passengers) and hands-on-steering wheel (drivers) are reported. The measurements were carried out under white noise vertical excitations of 0·25, 0·5 and 1·0m/s2r.m.s. acceleration magnitudes in the 0·5-40Hz frequency range and a track measured input (1·07m/s2). The measured data have been analyzed to study the effects of hands position, body mass, magnitude and type of vibration excitation, and feet position, on the biodynamic response expressed in terms of apparent mass. A comparison of the measured response of subjects assuming typical automotive postures involving inclined cushion, inclined backrest and full use of backrest support with data determined under different postural conditions and excitation levels revealed considerable differences. The biodynamic response of automobile occupants seated with hands in lap, peaks in the 6·5-8·6Hz frequency range, which is considerably higher than the reported range of fundamental frequencies (4·5-5Hz) in most other studies involving different experimental conditions. The peak magnitude tends to decrease considerably for the driving posture with hands-on-steering wheel, while a second peak in the 8-12 Hz range becomes more apparent for this posture. The results suggest that biodynamic response of occupants seated in automotive seats and subject to vertical vibration need to be characterized, as a minimum, by two distinct functions for passenger and driving postures. A higher body mass, in general, yields higher peak magnitude response and lower corresponding frequency for both postures. The strong dependence of the response on the body mass is further demonstrated by grouping the measured data into four different mass ranges: less than 60 kg, between 60·5 and 70 kg, between 70·5 and 80 kg, and above 80 kg. From the results, it is concluded that hands position and body mass have the most significant influence on the apparent mass response under automotive posture and vibration.

  8. Theoretical foundation, methods, and criteria for calibrating human vibration models using frequency response functions

    PubMed Central

    Dong, Ren G.; Welcome, Daniel E.; McDowell, Thomas W.; Wu, John Z.

    2015-01-01

    While simulations of the measured biodynamic responses of the whole human body or body segments to vibration are conventionally interpreted as summaries of biodynamic measurements, and the resulting models are considered quantitative, this study looked at these simulations from a different angle: model calibration. The specific aims of this study are to review and clarify the theoretical basis for model calibration, to help formulate the criteria for calibration validation, and to help appropriately select and apply calibration methods. In addition to established vibration theory, a novel theorem of mechanical vibration is also used to enhance the understanding of the mathematical and physical principles of the calibration. Based on this enhanced understanding, a set of criteria was proposed and used to systematically examine the calibration methods. Besides theoretical analyses, a numerical testing method is also used in the examination. This study identified the basic requirements for each calibration method to obtain a unique calibration solution. This study also confirmed that the solution becomes more robust if more than sufficient calibration references are provided. Practically, however, as more references are used, more inconsistencies can arise among the measured data for representing the biodynamic properties. To help account for the relative reliabilities of the references, a baseline weighting scheme is proposed. The analyses suggest that the best choice of calibration method depends on the modeling purpose, the model structure, and the availability and reliability of representative reference data. PMID:26740726

  9. Subsurface high resolution definition of subsurface heterogeneity for understanding the biodynamics of natural field systems: Advancing the ability for scaling to field conditions. 1998 annual progress report

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

    Majer, E.L.; Brockman, F.J.

    1998-06-01

    'This research is an integrated physical (geophysical and hydrologic) and microbial study using innovative geophysical imaging and microbial characterization methods to identify key scales of physical heterogeneities that affect the biodynamics of natural subsurface environments. Data from controlled laboratory and in-situ experiments at the INEEL Test Area North (TAN) site are being used to determine the dominant physical characteristics (lithologic, structural, and hydrologic) that can be imaged in-situ and correlated with microbial properties. The overall goal of this research is to contribute to the understanding of the interrelationships between transport properties and spatially varying physical, chemical, and microbiological heterogeneity. Themore » outcome will be an improved understanding of the relationship between physical and microbial heterogeneity, thus facilitating the design of bioremediation strategies in similar environments. This report summarizes work as of May 1998, the second year of the project. This work is an extension of basic research on natural heterogeneity first initiated within the DOE/OHER Subsurface Science Program (SSP) and is intended to be one of the building blocks of an integrated and collaborative approach with an INEEL/PNNL effort aimed at understanding the effect of physical heterogeneity on transport properties and biodynamics in natural systems. The work is closely integrated with other EMSP projects at INEEL (Rick Colwell et al.) and PNNL (Fred Brockman and Jim Fredrickson).'« less

  10. Using biodynamic models to reconcile differences between laboratory toxicity tests and field biomonitoring with aquatic insects

    USGS Publications Warehouse

    Buchwalter, D.B.; Cain, D.J.; Clements, W.H.; Luoma, S.N.

    2007-01-01

    Aquatic insects often dominate lotic ecosystems, yet these organisms are under-represented in trace metal toxicity databases. Furthermore, toxicity data for aquatic insects do not appear to reflect their actual sensitivities to metals in nature, because the concentrations required to elicit toxicity in the laboratory are considerably higher than those found to impact insect communities in the field. New approaches are therefore needed to better understand how and why insects are differentially susceptible to metal exposures. Biodynamic modeling is a powerful tool for understanding interspecific differences in trace metal bioaccumulation. Because bioaccumulation alone does not necessarily correlate with toxicity, we combined biokinetic parameters associated with dissolved cadmium exposures with studies of the subcellular compartmentalization of accumulated Cd. This combination of physiological traits allowed us to make predictions of susceptibility differences to dissolved Cd in three aquatic insect taxa: Ephemerella excrucians, Rhithrogena morrisoni, and Rhyacophila sp. We compared these predictions with long-term field monitoring data and toxicity tests with closely related taxa: Ephemerella infrequens, Rhithrogena hageni, and Rhyacophila brunea. Kinetic parameters allowed us to estimate steady-state concentrations, the time required to reach steady state, and the concentrations of Cd projected to be in potentially toxic compartments for different species. Species-specific physiological traits identified using biodynamic models provided a means for better understanding why toxicity assays with insects have failed to provide meaningful estimates for metal concentrations that would be expected to be protective in nature. ?? 2007 American Chemical Society.

  11. Construction of a biodynamic model for Cry protein production studies.

    PubMed

    Navarro-Mtz, Ana Karin; Pérez-Guevara, Fermín

    2014-12-01

    Mathematical models have been used from growth kinetic simulation to gen regulatory networks prediction for B. thuringiensis culture. However, this culture is a time dependent dynamic process where cells physiology suffers several changes depending on the changes in the cell environment. Therefore, through its culture, B. thuringiensis presents three phases related with the predominance of three major metabolic pathways: vegetative growth (Embded-Meyerhof-Parnas pathway), transition (γ-aminobutiric cycle) and sporulation (tricarboxylic acid cycle). There is not available a mathematical model that relates the different stages of cultivation with the metabolic pathway active on each one of them. Therefore, in the present study, and based on published data, a biodynamic model was generated to describe the dynamic of the three different phases based on their major metabolic pathways. The biodynamic model is used to study the interrelation between the different culture phases and their relationship with the Cry protein production. The model consists of three interconnected modules where each module represents one culture phase and its principal metabolic pathway. For model validation four new fermentations were done showing that the model constructed describes reasonably well the dynamic of the three phases. The main results of this model imply that poly-β-hydroxybutyrate is crucial for endospore and Cry protein production. According to the yields of dipicolinic acid and Cry from poly-β-hydroxybutyrate, calculated with the model, the endospore and Cry protein production are not just simultaneous and parallel processes they are also competitive processes.

  12. Modeling the Biodynamical Response of the Human Head for Injury Analysis

    DTIC Science & Technology

    2001-09-01

    1 II. BACKGROUND ..............................................5 A. HUMAN ANATOMY ......................................5...facilitate the simulation of the sled acceleration test used for model validation. A. HUMAN ANATOMY 1. The Spine The muscles and other soft tissue

  13. Advanced interdisciplinary technologies

    NASA Technical Reports Server (NTRS)

    Anderson, John L.

    1990-01-01

    The following topics are presented in view graph form: (1) breakthrough trust (space research and technology assessment); (2) bionics (technology derivatives from biological systems); (3) biodynamics (modeling of human biomechanical performance based on anatomical data); and (4) tethered atmospheric research probes.

  14. Unobtrusive Multimodal Biometric Authentication: The HUMABIO Project Concept

    NASA Astrophysics Data System (ADS)

    Damousis, Ioannis G.; Tzovaras, Dimitrios; Bekiaris, Evangelos

    2008-12-01

    Human Monitoring and Authentication using Biodynamic Indicators and Behavioural Analysis (HUMABIO) (2007) is an EU Specific Targeted Research Project (STREP) where new types of biometrics are combined with state of the art sensorial technologies in order to enhance security in a wide spectrum of applications. The project aims to develop a modular, robust, multimodal biometrics security authentication and monitoring system which utilizes a biodynamic physiological profile, unique for each individual, and advancements of the state-of-the art in behavioural and other biometrics, such as face, speech, gait recognition, and seat-based anthropometrics. Several shortcomings in biometric authentication will be addressed in the course of HUMABIO which will provide the basis for improving existing sensors, develop new algorithms, and design applications, towards creating new, unobtrusive biometric authentication procedures in security sensitive, controlled environments. This paper presents the concept of this project, describes its unobtrusive authentication demonstrator, and reports some preliminary results.

  15. Adaptive magnetorheological seat suspension for shock mitigation

    NASA Astrophysics Data System (ADS)

    Singh, Harinder J.; Wereley, Norman M.

    2013-04-01

    An adaptive magnetorheological seat suspension (AMSS) was analyzed for optimal protection of occupants from shock loads caused by the impact of a helicopter with the ground. The AMSS system consists of an adaptive linear stroke magnetorheological shock absorber (MRSA) integrated into the seat structure of a helicopter. The MRSA provides a large controllability yield force to accommodate a wide spectrum for shock mitigation. A multiple degrees-of-freedom nonlinear biodynamic model for a 50th percentile male occupant was integrated with the dynamics of MRSA and the governing equations of motion were investigated theoretically. The load-stroke profile of MRSA was optimized with the goal of minimizing the potential for injuries. The MRSA yield force and the shock absorber stroke limitations were the most crucial parameters for improved biodynamic response mitigation. An assessment of injuries based on established injury criteria for different body parts was carried out.

  16. Establishment of one-axis vibration test system for measurement of biodynamic response of human hand-arm system.

    PubMed

    Shibata, Nobuyuki; Hosoya, Naoki; Maeda, Setsuo

    2008-12-01

    Prolonged exposure to hand-arm vibration (HAV) due to use of hand-held power tools leads to an increased occurrence of symptoms of disorders in the vascular, neurological, and osteo-articular systems of the upper limbs called hand-arm vibration syndrome (HAVS). Biodynamic responses of the hand-arm system to vibration can be suggestive parameters that give us better assessment of exposure to HAV and fundamental data for design of low-vibration-exposure power tools. Recently, a single axis hand-arm vibration system has been installed in the Japan National Institute of Occupational Safety and Health (NIOSH). The aims of this study were to obtain the fundamental dynamic characteristics of an instrumented handle and to validate the performance and measurement accuracy of the system applied to dynamic response measurement. A pseudo-random vibration signal with a frequency range of 5-1,250 Hz and a power spectrum density of 1.0 (m/s2)2/Hz was used in this study. First the dynamic response of the instrumented handle without any weight was measured. After this measurement, the dynamic response measurement of the handle with weights mounted on the handle was performed. The apparent mass of a weight itself was obtained by using the mass cancellation method. The mass of the measuring cap on the instrumented handle was well compensated by using the mass cancellation method. Based on the 10% error tolerance, this handle can reliably measure the dynamic response represented by an apparent mass with a minimum weight of 2.0 g in a frequency range of 10.0 to 1,000 Hz. A marked increase in the AM magnitude of the weights of 15 g and 20 g in frequency ranges greater than 800 Hz is attributed not to the fundamental resonance frequency of the handle with weights, but to the fixation of the weight to the measuring cap. In this aspect, the peak of the AM magnitude can be reduced and hence should not be an obstacle to the biodynamic response measurement of the human hand-arm system. On the basis of the results obtained in this study, we conclude that this hand-arm vibration test system can be used to measure biodynamic response parameters of the human hand-arm system.

  17. Biodynamic evaluation of air traffic control students between 1960-1963.

    DOT National Transportation Integrated Search

    1971-03-01

    Between 1960-1963, a large number of ATC students in training at the FAA Aeronautical Center in Oklahoma City underwent a broad spectrum of biomedical evaluations conducted by the Civil Aeromedical Research Institute (CARI). Approximately 1,270 of th...

  18. Organic Addict. And Why Not?

    ERIC Educational Resources Information Center

    Pilliaud, Denis

    1993-01-01

    Discusses the practice of organic farming as used in Japan. Defines the biodynamic agricultural method based on the principle of the dynamics that control life on earth from the cosmos. Argues that organic farming does not benefit from chemicals used on neighboring farms. (MDH)

  19. A Survey of Biodynamic Test Devices and Methods,

    DTIC Science & Technology

    1984-04-01

    aca-a) *Cavfcr:.,: ( CncD : all tgat A~rply) Rane of Acceir!racion buration v.1 Sne __________ _________ _________ U.2. 1/2 Sn _______ _______ ______ e...State University. Dayton. Ohio 45435, USA. 12. )istribution Statement This document is distributed in accordance with A(VARI) policies and

  20. Experimentally fitted biodynamic models for pedestrian-structure interaction in walking situations

    NASA Astrophysics Data System (ADS)

    Toso, Marcelo André; Gomes, Herbert Martins; da Silva, Felipe Tavares; Pimentel, Roberto Leal

    2016-05-01

    The interaction between moving humans and structures usually occurs in slender structures in which the level of vibration is potentially high. Furthermore, there is the addition of mass to the structural system due to the presence of people and an increase in damping due to the human body´s ability to absorb vibrational energy. In this paper, a test campaign is presented to obtain parameters for a single degree of freedom (SDOF) biodynamic model that represents the action of a walking pedestrian in the vertical direction. The parameters of this model are the mass (m), damping (c) and stiffness (k). The measurements were performed on a force platform, and the inputs were the spectral acceleration amplitudes of the first three harmonics at the waist level of the test subjects and the corresponding amplitudes of the first three harmonics of the vertical ground reaction force. This leads to a system of nonlinear equations that is solved using a gradient-based optimization algorithm. A set of individuals took part in the tests to ensure inter-subject variability, and, regression expressions and an artificial neural network (ANN) were used to relate the biodynamic parameters to the pacing rate and the body mass of the pedestrians. The results showed some scatter in damping and stiffness that could not be precisely correlated with the masses and pacing rates of the subjects. The use of the ANN resulted in significant improvements in the parameter expressions with a low uncertainty. Finally, the measured vertical accelerations on a prototype footbridge show the adequacy of the numerical model for the representation of the effects of walking pedestrians on a structure. The results are consistent for many crowd densities.

  1. Suppression of biodynamic interference in head-tracked teleoperation

    NASA Technical Reports Server (NTRS)

    Lifshitz, S.; Merhav, S. J.; Grunwald, A. J.; Tucker, G. E.; Tischler, M. B.

    1991-01-01

    The utility of helmet-tracked sights to provide pointing commands for teleoperation of cameras, lasers, or antennas in aircraft is degraded by the presence of uncommanded, involuntary heat motion, referred to as biodynamic interference. This interference limits the achievable precision required in pointing tasks. The noise contributions due to biodynamic interference consists of an additive component which is correlated with aircraft vibration and an uncorrelated, nonadditive component, referred to as remnant. An experimental simulation study is described which investigated the improvements achievable in pointing and tracking precision using dynamic display shifting in the helmet-mounted display. The experiment was conducted in a six degree of freedom motion base simulator with an emulated helmet-mounted display. Highly experienced pilot subjects performed precision head-pointing tasks while manually flying a visual flight-path tracking task. Four schemes using adaptive and low-pass filtering of the head motion were evaluated to determine their effects on task performance and pilot workload in the presence of whole-body vibration characteristic of helicopter flight. The results indicate that, for tracking tasks involving continuously moving targets, improvements of up to 70 percent can be achieved in percent on-target dwelling time and of up to 35 percent in rms tracking error, with the adaptive plus low-pass filter configuration. The results with the same filter configuration for the task of capturing randomly-positioned, stationary targets show an increase of up to 340 percent in the number of targets captured and an improvement of up to 24 percent in the average capture time. The adaptive plus low-pass filter combination was considered to exhibit the best overall display dynamics by each of the subjects.

  2. Educational and Training Opportunities in Sustainable Agriculture. 5th Edition.

    ERIC Educational Resources Information Center

    Gates, Jane Potter

    This directory lists 151 programs in alternative farming systems (systems that aim at maintaining agricultural productivity and profitability, while protecting natural resources, especially sustainable, low-input, regenerative, biodynamic or organic farming and gardening). It includes programs conducted by colleges and universities, research…

  3. Biodynamic Response to Windblast.

    DTIC Science & Technology

    1975-07-01

    750 noeuda. Lea rioultata atatistiquea globaux donnent -47 ijectiona inortellea (18 %), 209 of riusaies (82 %), il: pilate errivant vivant mu aol...On entend par 6jection riummie 1. fait quo ise pilot* arrive vivant au sob K sans tenir compto dos blemauroo 6ventuellos qulil priaents. Dana notre

  4. 8 CFR 316.20 - American institutions of research, public international organizations, and designations under the...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Sociology and Anthropology), Northfield, MN. Center of Alcohol Studies, Laboratory of Applied Biodynamics of...), Fort Collins, CO. Colorado University (International Economic Studies Center), Boulder, CO. Columbia University (Parker School of Foreign and Comparative Law) and (Faculty of Pure Science), New York, NY...

  5. 8 CFR 316.20 - American institutions of research, public international organizations, and designations under the...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Sociology and Anthropology), Northfield, MN. Center of Alcohol Studies, Laboratory of Applied Biodynamics of...), Fort Collins, CO. Colorado University (International Economic Studies Center), Boulder, CO. Columbia University (Parker School of Foreign and Comparative Law) and (Faculty of Pure Science), New York, NY...

  6. 8 CFR 316.20 - American institutions of research, public international organizations, and designations under the...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Sociology and Anthropology), Northfield, MN. Center of Alcohol Studies, Laboratory of Applied Biodynamics of...), Fort Collins, CO. Colorado University (International Economic Studies Center), Boulder, CO. Columbia University (Parker School of Foreign and Comparative Law) and (Faculty of Pure Science), New York, NY...

  7. 8 CFR 316.20 - American institutions of research, public international organizations, and designations under the...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Sociology and Anthropology), Northfield, MN. Center of Alcohol Studies, Laboratory of Applied Biodynamics of...), Fort Collins, CO. Colorado University (International Economic Studies Center), Boulder, CO. Columbia University (Parker School of Foreign and Comparative Law) and (Faculty of Pure Science), New York, NY...

  8. 8 CFR 316.20 - American institutions of research, public international organizations, and designations under the...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Sociology and Anthropology), Northfield, MN. Center of Alcohol Studies, Laboratory of Applied Biodynamics of...), Fort Collins, CO. Colorado University (International Economic Studies Center), Boulder, CO. Columbia University (Parker School of Foreign and Comparative Law) and (Faculty of Pure Science), New York, NY...

  9. Sustainable Agriculture in Print: Current Books. Special Reference Briefs: SRB 95-02.

    ERIC Educational Resources Information Center

    National Agricultural Library, Beltsville, MD.

    Prepared by the Alternative Farming Systems Information Center (AFSIC) staff and volunteers, this annotated bibliography provides a list of 85 recently published books pertaining to sustainable agriculture. AFSIC focuses on alternative farming systems (e.g., sustainable, low-input, regenerative, biodynamic, and organic) that maintain agricultural…

  10. Practices to identify and preclude adverse Aircraft-and-Rotorcraft-Pilot Couplings - A design perspective

    NASA Astrophysics Data System (ADS)

    Pavel, Marilena D.; Masarati, Pierangelo; Gennaretti, Massimo; Jump, Michael; Zaichik, Larisa; Dang-Vu, Binh; Lu, Linghai; Yilmaz, Deniz; Quaranta, Giuseppe; Ionita, Achim; Serafini, Jacopo

    2015-07-01

    Understanding, predicting and supressing the inadvertent aircraft oscillations caused by Aircraft/Rotorcraft Pilot Couplings (A/RPC) is a challenging problem for designers. These are potential instabilities that arise from the effort of controlling aircraft with high response actuation systems. The present paper reviews, updates and discusses desirable practices to be used during the design process for unmasking A/RPC phenomena. These practices are stemming from the European Commission project ARISTOTEL Aircraft and Rotorcraft Pilot Couplings - Tools and Techniques for Alleviation and Detection (2010-2013) and are mainly related to aerodynamic and structural modelling of the aircraft/rotorcraft, pilot modelling and A/RPC prediction criteria. The paper proposes new methodologies for precluding adverse A/RPCs events taking into account the aeroelasticity of the structure and pilot biodynamic interaction. It is demonstrated that high-frequency accelerations due to structural elasticity cause negative effects on pilot control, since they lead to involuntary body and limb-manipulator system displacements and interfere with pilot's deliberate control activity (biodynamic interaction) and, finally, worsen handling quality ratings.

  11. Occupant Protection during Orion Crew Exploration Vehicle Landings

    NASA Technical Reports Server (NTRS)

    Gernhardt, Michael L.; Jones, J. A.; Granderson, B. K.; Somers, J. T.

    2009-01-01

    The constellation program is evaluating current vehicle design capabilities for nominal water landings and contingency land landings of the Orion Crew Exploration vehicle. The Orion Landing Strategy tiger team was formed to lead the technical effort for which associated activities include the current vehicle design, susceptibility to roll control and tip over, reviewing methods for assessing occupant injury during ascent / aborts /landings, developing an alternate seat/attenuation design solution which improves occupant protection and operability, and testing the seat/attenuation system designs to ensure valid results. The EVA physiology, systems and Performance (EPSP) project is leading the effort under the authority of the Tiger Team Steering committee to develop, verify, validate and accredit biodynamics models using a variety of crash and injury databases including NASCAR, Indy Car and military aircraft. The validated biodynamics models will be used by the Constellation program to evaluate a variety of vehicle, seat and restraint designs in the context of multiple nominal and off-nominal landing scenarios. The models will be used in conjunction with Acceptable Injury Risk definitions to provide new occupant protection requirements for the Constellation Program.

  12. Evaluation on subcellular partitioning and biodynamics of pulse copper toxicity in tilapia reveals impacts of a major environmental disturbance.

    PubMed

    Ju, Yun-Ru; Yang, Ying-Fei; Tsai, Jeng-Wei; Cheng, Yi-Hsien; Chen, Wei-Yu; Liao, Chung-Min

    2017-07-01

    Fluctuation exposure of trace metal copper (Cu) is ubiquitous in aquatic environments. The purpose of this study was to investigate the impacts of chronically pulsed exposure on biodynamics and subcellular partitioning of Cu in freshwater tilapia (Oreochromis mossambicus). Long-term 28-day pulsed Cu exposure experiments were performed to explore subcellular partitioning and toxicokinetics/toxicodynamics of Cu in tilapia. Subcellular partitioning linking with a metal influx scheme was used to estimate detoxification and elimination rates. A biotic ligand model-based damage assessment model was used to take into account environmental effects and biological mechanisms of Cu toxicity. We demonstrated that the probability causing 50% of susceptibility risk in response to pulse Cu exposure in generic Taiwan aquaculture ponds was ~33% of Cu in adverse physiologically associated, metabolically active pool, implicating no significant susceptibility risk for tilapia. We suggest that our integrated ecotoxicological models linking chronic exposure measurements with subcellular partitioning can facilitate a risk assessment framework that provides a predictive tool for preventive susceptibility reduction strategies for freshwater fish exposed to pulse metal stressors.

  13. Nonlinear dual-axis biodynamic response of the semi-supine human body during longitudinal horizontal whole-body vibration

    NASA Astrophysics Data System (ADS)

    Huang, Ya; Griffin, Michael J.

    2008-04-01

    The resonance frequencies in frequency response functions of the human body (e.g. apparent mass and transmissibility) decrease with increasing vibration magnitude. This nonlinear biodynamic response is found with various sitting and standing postures requiring postural control. The present study measured the apparent mass of the body in a relaxed semi-supine posture with two types of longitudinal horizontal vibration (in the z-axis of the semi-supine body): (i) continuous random excitation (0.25-20 Hz) at five magnitudes (0.125, 0.25, 0.5, 0.75 and 1.0 ms -2 rms); (ii) intermittent random excitation (0.25-20 Hz) alternately at 0.25 and 1.0 ms -2 rms. With continuous random vibration, the dominant primary resonance frequency in the median normalised apparent mass decreased from 3.7 to 2.4 Hz as the vibration magnitude increased from 0.125 to 1.0 ms -2 rms. A nonlinear response was apparent in both the horizontal ( z-axis) apparent mass and the vertical ( x-axis) cross-axis apparent mass. With intermittent random vibration, as the vibration magnitude increased from 0.25 to 1.0 ms -2 rms, the median resonance frequency of the apparent mass decreased from 3.2 to 2.5 Hz whereas, with continuous random vibration over the same range of magnitudes, the resonance frequency decreased from 3.4 to 2.4 Hz. The median change in the resonance frequency (between 0.25 and 1.0 ms -2 rms) was 0.6 Hz with the intermittent random vibration and 0.9 Hz with the continuous random vibration. With intermittent vibration, the resonance frequency was higher at the high magnitude and lower at the low magnitude than with continuous vibration at the same magnitudes. The responses were consistent with passive thixotropy being a primary cause of nonlinear biodynamic responses to whole-body vibration, although reflex activity of the muscles may also have an influence.

  14. Nonlinear dual-axis biodynamic response of the semi-supine human body during vertical whole-body vibration

    NASA Astrophysics Data System (ADS)

    Huang, Ya; Griffin, Michael J.

    2008-04-01

    Nonlinear biodynamic responses are evident in many studies of the apparent masses of sitting and standing subjects in static postures that require muscle activity for postural control. In the present study, 12 male subjects adopted a relaxed semi-supine posture assumed to involve less muscle activity than during static sitting and standing. The supine subjects were exposed to two types of vertical vibration (in the x-axis of the semi-supine body): (i) continuous random vibration (0.25-20 Hz) at five magnitudes (0.125, 0.25, 0.5, 0.75, and 1.0 m s -2 rms); (ii) intermittent random vibration (0.25-20 Hz) alternately at 0.25 and 1.0 m s -2 rms. With continuous random vibration, the dominant primary resonance frequency in the median normalised apparent mass decreased from 10.35 to 7.32 Hz as the vibration magnitude increased from 0.125 to 1.0 m s -2 rms. This nonlinear response was apparent in both the vertical ( x-axis) apparent mass and in the horizontal ( z-axis) cross-axis apparent mass. As the vibration magnitude increased from 0.25 to 1.0 m s -2 rms, the median resonance frequency of the apparent mass with intermittent random vibration decreased from 9.28 to 8.06 Hz whereas, over the same range of magnitudes with continuous random vibration, the resonance frequency decreased from 9.62 to 7.81 Hz. The median change in the resonance frequency (between 0.25 and 1.0 m s -2 rms) was 1.37 Hz with the intermittent random vibration and 1.71 with the continuous random vibration. With the intermittent vibration, the resonance frequency was higher at the high magnitude and lower at the low magnitude than with continuous vibration of the same magnitudes. The response was typical of thixotropy that may be a primary cause of the nonlinear biodynamic responses to whole-body vibration.

  15. Comparative Assessment of Torso and Seat Mounted Restraint Systems using Manikins on the Vertical Deceleration Tower

    DTIC Science & Technology

    2017-03-01

    experimental effort involving a series of +z-axis impact tests was conducted on the 711th Human Performance Wing’s Vertical Deceleration Tower (VDT...parameters) and a JSF-styled ejection seat configuration (combined non -baseline test parameters) produced similar biodynamic response parameters for the LOIS...Photography .............................................................................. 12 6.0 EXPERIMENTAL DESIGN

  16. Modeling of biodynamic responses distributed at the fingers and the palm of the human hand-arm system.

    PubMed

    Dong, Ren G; Dong, Jennie H; Wu, John Z; Rakheja, Subhash

    2007-01-01

    The objective of this study is to develop analytical models for simulating driving-point biodynamic responses distributed at the fingers and palm of the hand under vibration along the forearm direction (z(h)-axis). Two different clamp-like model structures are formulated to analyze the distributed responses at the fingers-handle and palm-handle interfaces, as opposed to the single driving point invariably considered in the reported models. The parameters of the proposed four- and five degrees-of-freedom models are identified through minimization of an rms error function of the model and measured responses under different hand actions, namely, fingers pull, push only, grip only, and combined push and grip. The results show that the responses predicted from both models agree reasonably well with the measured data in terms of distributed as well total impedance magnitude and phase. The variations in the identified model parameters under different hand actions are further discussed in view of the biological system behavior. The proposed models are considered to serve as useful tools for design and assessment of vibration isolation methods, and for developing a hand-arm simulator for vibration analysis of power tools.

  17. Cadmium ecophysiology in seven stonefly (Plecoptera) species: Delineating sources and estimating susceptibility

    USGS Publications Warehouse

    Martin, C.A.; Luoma, S.N.; Cain, D.J.; Buchwalter, D.B.

    2007-01-01

    A major challenge in ecotoxicology lies in generating data under experimental conditions that are relevant to understanding contaminant effects in nature. Biodynamic modeling combines species-specific physiological traits to make predictions of metal bioaccumulation that fare well when tested in the field. We generated biodynamic models for seven predatory stonefly (Plecoptera) species representing the families Perlidae (5) and Perlodidae (2). Each taxon was exposed to cadmium independently via diet and via solution. Species varied approximately 2.6 fold in predicted steady-state cadmium concentrations. Diet was the predominant source of accumulated cadmium in five of the seven species and averaged 53.2 ?? 9.6% and 90.2 ?? 3.7% of net Cd accumulation in perlids and perlodids, respectively. Differences in Cd bioaccumulation between the two families were largely driven by differences in dissolved accumulation rates, which were considerably slower in perlodids than in perlids. We further examined the subcellular compartmentalization of Cd accumulated from independent aqueous and dietary exposures. Predicted steady-state concentrations were modified to only consider Cd accumulated in metal-sensitive subcellular compartments. These values ranged 5.3 fold. We discuss this variability within a phylogenetic context and its implications for bioassessment. ?? 2007 American Chemical Society.

  18. Chemical composition and antifungal activity of plant extracts traditionally used in organic and biodynamic farming.

    PubMed

    Andreu, Vanessa; Levert, Annabel; Amiot, Anaïs; Cousin, Anaïs; Aveline, Nicolas; Bertrand, Cédric

    2018-03-07

    Five plant extracts traditionally used in organic and biodynamic farming for pest control and antifungal (downy mildew) disease management were selected after a farmer survey and analyzed for their chemical composition in LC-PDA-MS-MS and using adapted analytical method from food chemistry for determination of class of component (e.g., protein, sugar, lipids…). Their antifungal activity against Penicillium expansum, Botrytis cinerea, Botrytis allii, brown rot causing agents (Monilinia laxa and Monilinia fructigena), and grape downy mildew (Plasmopara viticola) was examined in vitro. White willow (Salix alba) and absinthe (Artemisia absinthium) ethanolic extracts were found to be the most effective in particular against Plasmopara viticola, with a total inhibition of spores germination when applied at 1000 mg/L. These extracts also showed a relatively low toxicity during preliminary ecotoxicological assays on Daphnia pulex. Extract from the bark of white willow contained some flavonoids, especially flavanones (eriodyctiol and derivates) and flavanols (catechins and derivates), as major compounds, whereas absinthe extract was rich in O-methylated flavanols and hydroxycinnamic acids. Thujone content in this extract was also determined by external calibration in GC-MS analysis, and its value was 0.004% dry extract.

  19. Intracellular Doppler Signatures of Platinum Sensitivity Captured by Biodynamic Profiling in Ovarian Xenografts

    NASA Astrophysics Data System (ADS)

    Merrill, Daniel; An, Ran; Sun, Hao; Yakubov, Bakhtiyor; Matei, Daniela; Turek, John; Nolte, David

    2016-01-01

    Three-dimensional (3D) tissue cultures are replacing conventional two-dimensional (2D) cultures for applications in cancer drug development. However, direct comparisons of in vitro 3D models relative to in vivo models derived from the same cell lines have not been reported because of the lack of sensitive optical probes that can extract high-content information from deep inside living tissue. Here we report the use of biodynamic imaging (BDI) to measure response to platinum in 3D living tissue. BDI combines low-coherence digital holography with intracellular Doppler spectroscopy to study tumor drug response. Human ovarian cancer cell lines were grown either in vitro as 3D multicellular monoculture spheroids or as xenografts in nude mice. Fragments of xenografts grown in vivo in nude mice from a platinum-sensitive human ovarian cell line showed rapid and dramatic signatures of induced cell death when exposed to platinum ex vivo, while the corresponding 3D multicellular spheroids grown in vitro showed negligible response. The differences in drug response between in vivo and in vitro growth have important implications for predicting chemotherapeutic response using tumor biopsies from patients or patient-derived xenografts.

  20. Naval Biodynamics Laboratory 1993 Command History

    DTIC Science & Technology

    1993-01-01

    position and alignment, camera optical calibration, photo target position, and standard anatomical coordinate systems based upon X-rays of each HRV...safety range. Before, during, and after each sled run, a physiological data acquisition system is used to collect and analyze physiological measurements ...experimental devices. It is also responsible for the configuring of field data measuring and acquisition systems for use aboard ships or at other field

  1. 50 (Fifty) Years of Research on Man in Flight

    DTIC Science & Technology

    1985-06-01

    h td ~il lcild FlightI IR’c’urch1)71.AI . .. 0 . . . . . . Advanced Flight Research 1970&1984 0 bo a I .41~ CII1(f’(l k/i h t Iu’raru/i l~)7(~-15’.~I I...Hazel, Mrs Branch Secretary BBD BIODYNAMIC EFFECTS BRANCH Bekele, Tamara, Ms Jonopulos, Michael, 9Sgt Kazarian. Leon, Dr Branch Chief Natvig

  2. International Conference on Environmental Ergonomics (4th) Held in Austin, Texas on 1-5 October 1990

    DTIC Science & Technology

    1991-01-15

    measurement error in relation 94 Ducharme, Michel B. to clothing and tissue insulation -- a simplified view 5 Reischl, Uwe Breathability measurements...PROTECTIVE CLOTHING Uwe Reischl, Francis N. Dukes-Dobos, Thomas E. Bernard and Kai Buller Department of Environmental and Occupational Health 0 College of...understood. 117 BREATHING APPARATUS AND VENTILATION William P. Morgan Biodynamics Laboratory University of Wisconsin- Madison 0 Madison , Wisconsin USA

  3. Animal Preparations to Assess Neurophysiological Effects of Bio-Dynamic Environments.

    DTIC Science & Technology

    1980-07-17

    deprivation in preventing the acquisition of visually-guided behaviors. The next study examined acquisition of visually-guided behaviors in six animals...Maffei, L. and Bisti, S. Binocular interaction in strabismic kittens deprived of vision. Science, 191, 579-580, 1976. Matin, L. A possible hybrid...function in cat visual cortex following prolonged deprivation . Exp. Brain Res., 25 (1976) 139-156. Hein, A. Visually controlled components of movement

  4. Biodynamic Assessment of the THOR-K Manikin

    DTIC Science & Technology

    2013-09-01

    finite element model, and for optimization of occupant seating systems and restraint system design for the MPCV and USAF aircraft ejection seats and...had the same rigid backrest, a rigid seat pan, a rigid footrest and leg support panel, but also provided side supports that restrict the motion of the... Ejection Seat (Technical Report AFRL-HE-WP-SR-2000-0002). Wright-Patterson AFB OH: Human Effectiveness Directorate, Air Force Research Laboratory

  5. Influence of growing system on nitrate accumulation in two varieties of lettuce and red radicchio of Treviso.

    PubMed

    Lucarini, Massimo; D'Evoli, Laura; Tufi, Sara; Gabrielli, Paolo; Paoletti, Sara; Di Ferdinando, Sandra; Lombardi-Boccia, Ginevra

    2012-11-01

    Green leafy vegetables contribute greatly to the total intake of nitrates from the daily diet. This study evaluates the influence of different cultivation systems on nitrate accumulation in leafy vegetables. Two varieties of lettuce (Lactuca sativa L.) (Lattuga Romana, Foglia di Quercia) and two varieties of red radicchio of Treviso (Cychorium intibus L.) (Early, Late) were selected. Lettuce varieties were both organically and biodynamically grown; red radicchio varieties were conventionally grown both in the field and in spring water. Both lettuce varieties biodynamically grown accumulated 1.3-2 times less nitrate than the respective organically grown plants. The two lettuce varieties showed differences in nitrate accumulating capacity: Foglia di Quercia was almost three times richer in nitrate than Lattuga Romana. The traditional growing systems applied to the red radicchio of Treviso varieties strongly influenced nitrate accumulation in leaves, the Early variety having up to 15 times higher nitrate than the Late variety. Our findings on nitrate levels in both lettuce and red radicchio of Treviso varieties suggest that both genetic factors and cultivation systems strongly affect the nitrate accumulation capacity. This study also highlights how the cultivation strategy can reduce nitrate levels in leafy vegetables, suggesting the possibility of modulating the N supply along the harvesting time. Copyright © 2011 Society of Chemical Industry.

  6. Modal analysis of human body vibration model for Indian subjects under sitting posture.

    PubMed

    Singh, Ishbir; Nigam, S P; Saran, V H

    2015-01-01

    Need and importance of modelling in human body vibration research studies are well established. The study of biodynamic responses of human beings can be classified into experimental and analytical methods. In the past few decades, plenty of mathematical models have been developed based on the diverse field measurements to describe the biodynamic responses of human beings. In this paper, a complete study on lumped parameter model derived from 50th percentile anthropometric data for a seated 54- kg Indian male subject without backrest support under free un-damped conditions has been carried out considering human body segments to be of ellipsoidal shape. Conventional lumped parameter modelling considers the human body as several rigid masses interconnected by springs and dampers. In this study, concept of mass of interconnecting springs has been incorporated and eigenvalues thus obtained are found to be closer to the values reported in the literature. Results obtained clearly establish decoupling of vertical and fore-and-aft oscillations. The mathematical modelling of human body vibration studies help in validating the experimental investigations for ride comfort of a sitting subject. This study clearly establishes the decoupling of vertical and fore-and-aft vibrations and helps in better understanding of possible human response to single and multi-axial excitations.

  7. Biodynamic response at the palm of the human hand subjected to a random vibration.

    PubMed

    Dong, Ren G; McDowell, Thomas W; Welcome, Daniel E

    2005-01-01

    This study investigated the biodynamic response (BR) distributed at the palm of the hand subjected to a random vibration. Twelve male subjects were used in the experiment. Each subject applied three coupling actions (grip-only, push-only, and combined grip and push) on a simulated tool handle at three different levels (50, 75, and 100 N) of palm force. This study found that the hand-arm system resonated mostly in the frequency range of 20 to 50 Hz, depending on the specific test treatment and individual characteristics. The maximum vibration power transmission through the palm occurred at the resonant frequency. Increasing the effective palm force generally increased the BR magnitude and resonant frequency. The apparent stiffness measured at the middle frequencies (80-100 Hz) is correlated to the BR in almost the entire frequency range (20-1,000 Hz). Under the same palm force, the push-only action corresponded to the highest BR values while the grip-only action generally produced the lowest values. Since the resonant frequency range matches the dominant vibration frequency range of many percussive tools, it is anticipated that the palm BR and vibration power transmission may have an association with vibration-induced injuries or disorders in the wrist-arm system among the workers using these tools.

  8. Biodynamic imaging for phenotypic profiling of three-dimensional tissue culture

    PubMed Central

    Sun, Hao; Merrill, Daniel; An, Ran; Turek, John; Matei, Daniela; Nolte, David D.

    2017-01-01

    Abstract. Three-dimensional (3-D) tissue culture represents a more biologically relevant environment for testing new drugs compared to conventional two-dimensional cancer cell culture models. Biodynamic imaging is a high-content 3-D optical imaging technology based on low-coherence interferometry and digital holography that uses dynamic speckle as high-content image contrast to probe deep inside 3-D tissue. Speckle contrast is shown to be a scaling function of the acquisition time relative to the persistence time of intracellular transport and hence provides a measure of cellular activity. Cellular responses of 3-D multicellular spheroids to paclitaxel are compared among three different growth techniques: rotating bioreactor (BR), hanging-drop (HD), and nonadherent (U-bottom, UB) plate spheroids, compared with ex vivo living tissues. HD spheroids have the most homogeneous tissue, whereas BR spheroids display large sample-to-sample variability as well as spatial heterogeneity. The responses of BR-grown tumor spheroids to paclitaxel are more similar to those of ex vivo biopsies than the responses of spheroids grown using HD or plate methods. The rate of mitosis inhibition by application of taxol is measured through tissue dynamics spectroscopic imaging, demonstrating the ability to monitor antimitotic chemotherapy. These results illustrate the potential use of low-coherence digital holography for 3-D pharmaceutical screening applications. PMID:28301634

  9. Measurement and modeling of polychlorinated biphenyl bioaccumulation from sediment for the marine polychaete neanthes arenaceodentata and response to sorbent amendment

    USGS Publications Warehouse

    Janssen, E.M.-L.; Croteau, M.-N.; Luoma, S.N.; Luthy, R.G.

    2010-01-01

    Bioaccumulation rates of polychlorinated biphenyls (PCBs) for the marine polychaete Neanthes arenaceodentata were characterized, including PCB uptake rates from water and sediment, and the effect of sorbent amendment to the sediment on PCB bioavailability, organism growth, and lipid content. Physiological parameters were incorporated into a biodynamic model to predict contaminant uptake. The results indicate rapid PCB uptake from contaminated sediment and significant organism growth dilution during time-series exposure studies. PCB uptake from the aqueous phase accounted for less than 3% of the total uptake for this deposit-feeder. Proportional increase of gut residence time and assimilation efficiency as a consequence of the organism's growth was assessed by PCB uptake and a reactor theory model of gut architecture. Pulse-chase feeding and multilabeled stable isotope tracing techniques proved high sediment ingestion rates (i.e., 6?10 times of dry body weight per day) indicating that such deposit-feeders are promising biological indicators for sediment risk assessment. Activated carbon amendment reduced PCB uptake by 95% in laboratory experiments with no observed adverse growth effects on the marine polychaete. Biodynamic modeling explained the observed PCB body burdens for N. arenaceodentata, with and without sorbent amendment. ?? 2009 American Chemical Society.

  10. Biodynamic imaging for phenotypic profiling of three-dimensional tissue culture

    NASA Astrophysics Data System (ADS)

    Sun, Hao; Merrill, Daniel; An, Ran; Turek, John; Matei, Daniela; Nolte, David D.

    2017-01-01

    Three-dimensional (3-D) tissue culture represents a more biologically relevant environment for testing new drugs compared to conventional two-dimensional cancer cell culture models. Biodynamic imaging is a high-content 3-D optical imaging technology based on low-coherence interferometry and digital holography that uses dynamic speckle as high-content image contrast to probe deep inside 3-D tissue. Speckle contrast is shown to be a scaling function of the acquisition time relative to the persistence time of intracellular transport and hence provides a measure of cellular activity. Cellular responses of 3-D multicellular spheroids to paclitaxel are compared among three different growth techniques: rotating bioreactor (BR), hanging-drop (HD), and nonadherent (U-bottom, UB) plate spheroids, compared with ex vivo living tissues. HD spheroids have the most homogeneous tissue, whereas BR spheroids display large sample-to-sample variability as well as spatial heterogeneity. The responses of BR-grown tumor spheroids to paclitaxel are more similar to those of ex vivo biopsies than the responses of spheroids grown using HD or plate methods. The rate of mitosis inhibition by application of taxol is measured through tissue dynamics spectroscopic imaging, demonstrating the ability to monitor antimitotic chemotherapy. These results illustrate the potential use of low-coherence digital holography for 3-D pharmaceutical screening applications.

  11. Overviews of Emerging Research Techniques in Hearing, Bioacoustics, and Biomechanics: Proceedings of the 1981 Meeting

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

    Not Available

    These proceedings of the 1981 annual meeting of the Committee on Hearing, Bioacoustics, and Biomechanics cover topics of emerging research in several areas of interest to the Committee. Topics covered include: hair cell function; transduction process of hair cells; speech synthesis; machine recognition of words; neuromagnetic analysis of sensory systems; tinnitus; tactile communication of speech; and biodynamic research at the Air Force Aerospace Medical Research Laboratory.

  12. The Position and Mobility of the Shoulder, Spinal Column and Pelvis in Seated Subjects.

    DTIC Science & Technology

    1985-02-01

    Wright-Patterson AFB acted as contract monitor; and Ints Kaleps, * Ph.D., Chief, Modeling and Analysis Branch, Biodynamics and Bioengineering Division...lumbar flexion and luibar extension motion series. Fewer motion segments are available for shoulder abduction motion analysis . These data are reported in...the measurements of this cadaver, samples of muscle and tendon were examined histologically to 12 attachments to trolley and arm cuff so that it

  13. Biodynamics of attachments used in overdentures: experimental analysis with photoelasticity.

    PubMed

    Labaig, C; Marco, R; Fons, A; Selva, E J

    1997-03-01

    Treatment with overdentures is an alternative to conventional complete prostheses. Different types of attachments can be placed in natural teeth that act as retainers for overdentures. The photoelastic relationship between the design of the attachment and the distribution of occlusal forces among the abutment teeth and the distal alveolar ridges was examined. The results were used to develop a classification for clinical cases so that the correct attachment design can be selected.

  14. Modeling the Biodynamical Response of the Human Thorax with Body Armor from a Bullet Impact

    DTIC Science & Technology

    2001-03-01

    inferior vena cava to the right auricle. From the right auricle, the blood is passed into the right ventricle. The right ventricle pumps the blood...the rib and vertebrae is modeled with two beam elements. To create the subcoastal angle, vertical cartilaginous connections at the inferior edge of...brachiocephalic aorta, the aorta, pulmonary arteries and veins, internal jugular veins, brachial veins, and superior vena cava . These vessels are modeled

  15. Reliability of Slope Scores for Individuals.

    DTIC Science & Technology

    1983-04-01

    RD-Ai3I 252 RELIABILITY OF SLOPE SCORES FOR XNDIVIDUALS( U ) NAVAL i/ BIODYNAMICS LAB*NE&I ORLEANS LA R C CARTER ET AL. APR 83 NBDL-93RS UNCLASSIFIED F... Neisser , 1963), search for typographical errors in prose (Schindler, 1978), and choice reaction time (Teichner, 1978) were studied with respect to the...17 Experiment 4: Letter Search Method A letter-search task was administered to 23 subjects in the manner of Neisser (1963). Subjects were presented

  16. Biodynamic Assessment of Pilot Knee-Board Configurations During Simulated T-38 Catapult Acceleration

    DTIC Science & Technology

    2015-04-01

    Apple iPad Mini with a shock case. The T-38C ejection pulse was simulated using the Vertical Deceleration Tower (VDT) set-up with a Martin Baker Mk...Figure 6. Free-body Diagram to Illustrate Loading and Bending Moment at Mid-Point of Femur (Schematic from Kennedy, VPI Thesis , 2004...kneeboard configuration compared to the paper kneeboard configuration. The proposed kneeboard configuration consisted of an Apple iPad Mini with a

  17. Bibliography of NBDL (Naval Biodynamics Laboratory) Publications,

    DTIC Science & Technology

    1987-01-28

    of Pro- ceedings of 9th International Conference in Engineering on Medicine and Biology , Melbourne, Australia, Aug 1971, 154 pp. 3.15 Ewing, C. L...75thFAnnii1"onfer6nce on Engineerng in Medicine and Biology . Miami Beach, FL, 4 Oct 1972, 241 pp. 3.23 Becker, E. B. Measurement of Mass Distribution...Pepper, R. L. & Wiker, S. F. Perfonnance Evaluation Tests for Environmental Researh (PETER): Collected Papers. NBUL Research Report, NBUL-8URO(8

  18. Control and postural thixotropy of the forearm muscles: changes caused by cold.

    PubMed

    Lakie, M; Walsh, E G; Wright, G W

    1986-01-01

    The forearm was cooled in water at 5-10 degrees C while wrist biodynamics were investigated. Pronounced loosening following a perturbation (thixotropy) was no longer seen. The wrist became stiffer for large or moderate but not small movements; EMG activity did not increase. Cooling the wrist alone, or opposite forearm, was without effect. The ability to make rapid reciprocating movements was reduced and muscle relaxation time was increased. Single movements were not affected.

  19. Control and postural thixotropy of the forearm muscles: changes caused by cold.

    PubMed Central

    Lakie, M; Walsh, E G; Wright, G W

    1986-01-01

    The forearm was cooled in water at 5-10 degrees C while wrist biodynamics were investigated. Pronounced loosening following a perturbation (thixotropy) was no longer seen. The wrist became stiffer for large or moderate but not small movements; EMG activity did not increase. Cooling the wrist alone, or opposite forearm, was without effect. The ability to make rapid reciprocating movements was reduced and muscle relaxation time was increased. Single movements were not affected. PMID:3958734

  20. Simulation of Thrust-Vectored Aircraft Maneuvers on a Human Centrifuge: Model Validation and Design for the Dynamic Environment Simulator

    DTIC Science & Technology

    1998-09-01

    reviewed and is approved for publication. FOR THE DIRECTOR ROGER L. STORK , Colonel, USAF, BSC Chief, Biodynamics and Protection Division Air Force Research...possible disorienting stimuli. Short radius yaw rotational movements that occur in helicopter flight and vertical take off and landing (VTOL) fixed wing ... wing flight. Aeronautical terms and thought has evolved. Tactical concepts, once thought inviolate, are changing. New terms are emerging and the very

  1. Microcomputer Enhancement of the Articulated Total Body (ATB) Biodynamic Modeling System

    DTIC Science & Technology

    1990-01-01

    products. In view of the broad market base, continued hardware and software support can be reasonably expected. The Intel family of microprocessors...time library. Their use became sufficiently widespread that "after- market " support libraries have been written for several devices, such as the...11,11,82,12,12,11,11,12) , NPRT4 HEDING 11 LOLD - FALSE. HED ING LNEW - .TRUE. HEDING GO TO 13 HEDING 12 LOLD - .TRUE. HEDING LNEW -FALSE. FIEDING 13 MT -20 HEDING NLINES

  2. To Predict the Body’s Strength

    DTIC Science & Technology

    1988-11-01

    requests to Henning E. Von Gierke, Dr. Eng., T"rector, Biodynamics & Bioengineering Division, Wright-Patterson Fig. 1. The anatomy of the human neck ...aircraft emerged. This idea generated the 0 8.O- 0 question, "How much acceleration in the buttocks- 4 0 to- head direction is tolerable in ejecting a...determine that the required 10-12 G head - 0 . JJwards acceleration would be tolerable for I second (21). 01O c 0 0And that was the criteria for the first

  3. Biokinetics and Biodynamics of Nanomaterial Interactions

    DTIC Science & Technology

    2009-09-30

    HEK viability. The medium from each treatment set of the dosed cells was removed, pooled into a microfuge tube , and quickly frozen to -80ºC until...Trump’s fixative at 4ºC. The cells were rinsed in 0.1M phosphate buffer (pH 7.2), pelleted in a microfuge tube , resuspended, and quickly pelleted in 3...formulation on in vitro human skin localized NP in the upper stratum corneum with minimal penetration (Cross et al., 2007) and microfine zinc oxide with a

  4. Positive effects, side effects, and adverse events of clinical holistic medicine. A review of Gerda Boyesen's nonpharmaceutical mind-body medicine (biodynamic body-psychotherapy) at two centers in the United Kingdom and Germany.

    PubMed

    Allmer, Charlotte; Ventegodt, Søren; Kandel, Isack; Merrick, Joav

    2009-01-01

    To review adverse events of intensive, clinical holistic medicine (CHM) as it is practiced in holistic body-psychotherapy in England and Germany. Gerda Boyesen's "biodynamic body-psychotherapy" (BBP) is an intensive type of holistic mind-body medicine used by Boyesen at two centers. About 13,500 patients were treated during 1985-2005 period and studied for side effects and adverse events. The first author worked closely with Boyesen 1995-2005 with full insight in all aspects of the therapy and provided the data on side-effects. Therapy helped chronic patients with physical, psychological, sexual, psychiatric and existential problems to improve health, ability, and quality of life (NNT (number needed to treat) = 1-3). Effective in the treatment of mentally ill patients (schizophrenia, anxiety, poor mental health, low general ability). For retraumatization, brief reactive psychosis, depression, depersonalization and derealization, implanted memories, side effects from manipulations of the body, suicide/suicide attempts, hospitalization for physical and mental health problem during or 90 days after treatment, NNH (number needed to harm) > 13,500. Intensive, holistic non-drug medicine is helpful for physical, sexual, psychological, psychiatric and existential problems and is completely safe for the patient. The therapeutic value TV = NNH/NNT > 5,000. Altogether about 18,000 patients treated with different subtypes of CHM in four different countries have now been evaluated for effects, side effects and adverse events, with similar results.

  5. Application of biodynamic imaging for personalized chemotherapy in canine lymphoma

    NASA Astrophysics Data System (ADS)

    Custead, Michelle R.

    Biodynamic imaging (BDI) is a novel phenotypic cancer profiling technology which characterizes changes in cellular and subcellular motion in living tumor tissue samples following in vitro or ex vivo treatment with chemotherapeutics. The ability of BDI to predict clinical response to single-agent doxorubicin chemotherapy was tested in ten dogs with naturally-occurring non-Hodgkin's lymphomas (NHL). Pre-treatment tumor biopsy samples were obtained from all dogs and treated with doxorubicin (10 muM) ex vivo. BDI captured cellular and subcellular motility measures on all biopsy samples at baseline and at regular intervals for 9 hours following drug application. All dogs subsequently received treatment with a standard single-agent doxorubicin protocol. Objective response (OR) to doxorubicin and progression-free survival time (PFST) following chemotherapy were recorded for all dogs. The dynamic biomarkers measured by BDI were entered into a multivariate logistic model to determine the extent to which BDI predicted OR and PFST following doxorubicin therapy. The model showed that the sensitivity, specificity, and accuracy of BDI for predicting treatment outcome were 95%, 91%, and 93%, respectively. To account for possible over-fitting of data to the predictive model, cross-validation with a one-left-out analysis was performed, and the adjusted sensitivity, specificity, and accuracy following this analysis were 93%, 87%, and 91%, respectively. These findings suggest that BDI can predict, with high accuracy, treatment outcome following single-agent doxorubicin chemotherapy in a relevant spontaneous canine cancer model, and is a promising novel technology for advancing personalized cancer medicine.

  6. Chemical Biodynamics Division: Annual report, October 1, 1985-September 30, 1986

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

    Not Available

    1986-10-01

    The research in the Laboratory of Chemical Biodynamics is almost entirely fundamental research. The biological research component is strongly dominated by a long term interest in two main themes which make up our Structural Biology Program. The first interest has to do with understanding the molecular dynamics of photosynthesis. The Laboratory's investigators are studying the various components that make up the photosynthetic reaction center complexes in many different organisms. This work not only involves understanding the kinetics of energy transfer and storage in plants, but also includes studies to work out how photosynthetic cells regulate the expression of genes encodingmore » the photosynthetic apparatus. The second biological theme is a series of investigations into the relationship between structure and function in nucleic acids. Our basic mission in this program is to couple our chemical and biophysical expertise to understand how not only the primary structure of nucleic acids, but also higher levels of structure including interactions with proteins and other nucleic acids regulate the functional activity of genes. In the chemical sciences work in the Laboratory, our investigators are increasing our understanding of the fundamental chemistry of electronically excited molecules, a critical dimension of every photosynthetic energy storage process. We are developing approaches not only toward the utilization of sophisticated chemistry to store photon energy, but also to develop systems that can emulate the photosynthetic apparatus in the trapping and transfer of photosynthetic energy.« less

  7. Bibliography of Research Reports and Publications Issued by the Biodynamics and Bioengineering Division, 1944-1984.

    DTIC Science & Technology

    1985-04-01

    Ratino, R.K.H. Geber , A.A. Karl, D.R. Nelson, "OPTO Electronic Methodology Suitable for Electroretinographic Investigations During Environmental Stess...R.K.H. Geber , A.A. Karl, D.R. Nelson, "OPTO Electronic Methodology Suitable for Electroretinographic Investigations During Environmental Stess...6 Section M -Page 167 Author Index Gaudio, R. L-62, 67 Gawain,G.C.V. A-12 Geber ,R.K.H. G-42,H-22 Geer,R.L. F-92 Gehrich,J.L. A-273 Gell,C.F. D-33,F-97

  8. [Periosteal reactions in bone tumors (author's transl)].

    PubMed

    Heuck, F

    1979-08-01

    Morphology of solid, lamellar and spicular periosteal reactions of benign and malignant primary and metastatic bone tumors in x-ray-pictures with regard to common and specific characteristics of different bone tumors is presented. The specific behaviour of the periosteum itself and of the subperiosteal region as an expression of the reactive biodynamics in skeletal neoplasia is demonstrated; and the diagnostic value of the radiograph is explained. The possibilities but also the limitations of sophisticated radiologic image analysis in establishing a differential diagnosis and a diagnosis of bone tumors and other bone lesions are discussed.

  9. Models and Analogues for the Evaluation of Human Biodynamic Response, Performance and Protection

    DTIC Science & Technology

    1979-06-01

    but in a point situated more ventrally . Nid-sagittal sacral curvature, length-width proportions and the height of the mid-sagittal curvature are...principal moments of che new ellipsoid are then calculated. I* , ioV- cm2 275 a:.s 1.981Iola - 82.99 225 175 125 75- 50 75 100 12S , S5 O75 Ix.,, to...along and three angulations about the three axes of the coordinate system. The complete descrip- tion of the behavior of a FSU can be obtained by

  10. Differential bioaccumulation patterns of nanosized and dissolved silver in a land snail Achatina fulica.

    PubMed

    Chen, Yuanzhen; Si, Youbin; Zhou, Dongmei; Dang, Fei

    2017-03-01

    With the increasing application in antimicrobial products, silver nanoparticles (AgNP) are inevitably released into the terrestrial environment, and pose potential risks to invertebrates such as land snails Achatina fulica, which take up AgNP from food and water. Here we differentiate Ag uptake biodynamic between Ag forms (i.e., PVP-AgNP vs. AgNO 3 ) and between exposure pathways. Snails assimilated Ag efficiently from lettuce leaves pre-exposed to AgNP, with assimilation efficiencies (AEs) averaging 62-85% and food ingestion rates of 0.11 ± 0.03 g g -1  d -1 . Dietary Ag bioavailability was independent on Ag forms, as revealed by comparable AEs between AgNP and AgNO 3 . However, the uptake rate constant from water was much lower for AgNP relative to AgNO 3 (2 × 10 -4 vs. 0.12 L g -1  d -1 ). The elimination rate constants were 0.0093 ± 0.0037 d -1 for AgNP and 0.019 ± 0.0077 d -1 for AgNO 3 . Biodynamic modeling further showed that dietary exposure was the dominant uptake pathway for AgNP in most circumstances, while for AgNO 3 the relative importance of waterborne and dietary exposure depended on Ag concentrations in food and water. Our findings highlight the importance of dietary uptake of AgNP during bioaccumulation, which should be considered in the risk assessment of these nanoparticles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Biodynamic modeling of PCB uptake by Macoma balthica and Corbicula fluminea from sediment amended with activated carbon

    USGS Publications Warehouse

    McLeod, Pamela B.; Luoma, S.N.; Luthy, R.G.

    2008-01-01

    Activated carbon amendment was assessed in the laboratory as a remediation strategy for freshwater sediment contaminated with polychlorinated biphenyls (PCBs) from the Grasse River (near Massena, NY). Three end points were evaluated: aqueous equilibrium PCB concentration, uptake into semipermeable membrane devices (SPMDs), and 28-day bioaccumulation in the clam Corbicula fluminea. PCB uptake by water, SPMDs, and clams followed similar trends, with reductions increasing as a function of carbon dose. Average percent reductions in clam tissue PCBs were 67, 86, and 95% for activated carbon doses of 0.7, 1.3, and 2.5% dry wt, respectively. A biodynamic model that incorporates sediment geochemistry and dietary and aqueous uptake routes was found to agree well with observed uptake by C. fluminea in our laboratory test systems. Results from this study were compared to 28-day bioaccumulation experiments involving PCB-contaminated sediment from Hunters Point Naval Shipyard (San Francisco Bay, CA) and the clam Macoma balthica. Due to differences in feeding strategy, M. balthica deposit-feeds whereas C. fluminea filter-feeds, the relative importance of the aqueous uptake route is predicted to be much higher for C. fluminea than for M. balthica. Whereas M. balthica takes up approximately 90% of its body burden through sediment ingestion, C. fluminea only accumulates approximately 45% via this route. In both cases, results strongly suggest that it is the mass transfer of PCBs from native sediment to added carbon particles, not merely reductions in aqueous PCB concentrations, that effectively reduces PCB bioavailability and uptake by sediment-dwelling organisms. ?? 2008 American Chemical Society.

  12. Detection of chaotic dynamics in human gait signals from mobile devices

    NASA Astrophysics Data System (ADS)

    DelMarco, Stephen; Deng, Yunbin

    2017-05-01

    The ubiquity of mobile devices offers the opportunity to exploit device-generated signal data for biometric identification, health monitoring, and activity recognition. In particular, mobile devices contain an Inertial Measurement Unit (IMU) that produces acceleration and rotational rate information from the IMU accelerometers and gyros. These signals reflect motion properties of the human carrier. It is well-known that the complexity of bio-dynamical systems gives rise to chaotic dynamics. Knowledge of chaotic properties of these systems has shown utility, for example, in detecting abnormal medical conditions and neurological disorders. Chaotic dynamics has been found, in the lab, in bio-dynamical systems data such as electrocardiogram (heart), electroencephalogram (brain), and gait data. In this paper, we investigate the following question: can we detect chaotic dynamics in human gait as measured by IMU acceleration and gyro data from mobile phones? To detect chaotic dynamics, we perform recurrence analysis on real gyro and accelerometer signal data obtained from mobile devices. We apply the delay coordinate embedding approach from Takens' theorem to reconstruct the phase space trajectory of the multi-dimensional gait dynamical system. We use mutual information properties of the signal to estimate the appropriate delay value, and the false nearest neighbor approach to determine the phase space embedding dimension. We use a correlation dimension-based approach together with estimation of the largest Lyapunov exponent to make the chaotic dynamics detection decision. We investigate the ability to detect chaotic dynamics for the different one-dimensional IMU signals, across human subject and walking modes, and as a function of different phone locations on the human carrier.

  13. [Chemical and biological evaluation of the effect of plant extracts against Plasmodium berghei].

    PubMed

    Castro, O; Barrios, M; Chinchilla, M; Guerrero, O

    1996-08-01

    Extracts from thirteen species of plants were evaluated by "in vivo" antimalarial test against plasmodium berghei effects. Significant activities were observed in the ethyl acetate and aqueous extracts, elaborated of Cedrela tonduzii leaves, Trichilia havanensis and Trichilia americana barks, Neurolaena lobata and Gliricidia sepium leaves and Duranta repens fruits. Compounds identified include flavanoids, coumarins, mellilotic acid and iridoids which some kind of biodynamic activity has previously been reported. The flavone quercetin 1 purified from C. tonduzii gave strong antimalarial activity, however, its respective glucosides (quercetin 3-glucoside 2 y robinine 7) showed little significant activity.

  14. Influence of support conditions on vertical whole-body vibration of the seated human body.

    PubMed

    M-Pranesh, Anand; Rakheja, Subhash; Demont, Richard

    2010-01-01

    The vibration transmission to the lumbar and thoracic segments of seated human subjects exposed to whole body vibration of a vehicular nature have been mostly characterised without the back and hand supports, which is not representative of general driving conditions. This non-invasive experimental study investigated the transmission of vertical seat vibration to selected vertebrae and the head along the vertical and fore-aft axes of twelve male human subjects seated on a rigid seat and exposed to random vertical excitation in the 0.5-20 Hz range. The measurements were performed under four different sitting postures involving combinations of back support conditions and hands positions, and three difference magnitudes of vertical vibration (0.25, 0.5 and 1.0 m/s(2) rms acceleration). The results showed significant errors induced by sensor misalignment and skin effects, which required appropriate correction methodologies. The averaged corrected responses revealed that the back support attenuates vibration in the vertical axis to all the body locations while increasing the fore-aft transmissibility at the C7 and T5. The hands position generally has a relatively smaller effect, showing some influences on the C7 and L5 vibration. Sitting without a back support resulted in very low magnitude fore-aft vibration at T5, which was substantially higher with a back support, suggestive of a probable change in the body's vibration mode. The effect of back support was observed to be very small on the horizontal vibration of the lower thoracic and lumbar regions. The results suggest that distinctly different target body-segment biodynamic functions need to be defined for different support conditions in order to represent the unique contribution of the specific support condition. These datasets may then be useful for the development of biodynamic models.

  15. Some Aspects of the Investigation of Random Vibration Influence on Ride Comfort

    NASA Astrophysics Data System (ADS)

    DEMIĆ, M.; LUKIĆ, J.; MILIĆ, Ž.

    2002-05-01

    Contemporary vehicles must satisfy high ride comfort criteria. This paper attempts to develop criteria for ride comfort improvement. The highest loading levels have been found to be in the vertical direction and the lowest in lateral direction in passenger cars and trucks. These results have formed the basis for further laboratory and field investigations. An investigation of the human body behaviour under random vibrations is reported in this paper. The research included two phases; biodynamic research and ride comfort investigation. A group of 30 subjects was tested. The influence of broadband random vibrations on the human body was examined through the seat-to-head transmissibility function (STHT). Initially, vertical and fore and aft vibrations were considered. Multi-directional vibration was also investigated. In the biodynamic research, subjects were exposed to 0·55, 1·75 and 2·25 m/s2 r.m.s. vibration levels in the 0·5- 40 Hz frequency domain. The influence of sitting position on human body behaviour under two axial vibrations was also examined. Data analysis showed that the human body behaviour under two-directional random vibrations could not be approximated by superposition of one-directional random vibrations. Non-linearity of the seated human body in the vertical and fore and aft directions was observed. Seat-backrest angle also influenced STHT. In the second phase of experimental research, a new method for the assessment of the influence of narrowband random vibration on the human body was formulated and tested. It included determination of equivalent comfort curves in the vertical and fore and aft directions under one- and two-directional narrowband random vibrations. Equivalent comfort curves for durations of 2·5, 4 and 8 h were determined.

  16. Exploratory Research and Development Fund, FY 1990

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

    Not Available

    1992-05-01

    The Lawrence Berkeley Laboratory Exploratory R D Fund FY 1990 report is compiled from annual reports submitted by principal investigators following the close of the fiscal year. This report describes the projects supported and summarizes their accomplishments. It constitutes a part of an Exploratory R D Fund (ERF) planning and documentation process that includes an annual planning cycle, projection selection, implementation, and review. The research areas covered in this report are: Accelerator and fusion research; applied science; cell and molecular biology; chemical biodynamics; chemical sciences; earth sciences; engineering; information and computing sciences; materials sciences; nuclear science; physics and research medicinemore » and radiation biophysics.« less

  17. Soil zinc and cadmium availability and uptake by wheat (Triticum aestivum L.) as affected by long-term organic matter management

    NASA Astrophysics Data System (ADS)

    Grüter, Roman; Costerousse, Benjamin; Mayer, Jochen; Mäder, Paul; Thonar, Cécile; Frossard, Emmanuel; Schulin, Rainer; Tandy, Susan

    2017-04-01

    Zinc (Zn) deficiency is a widespread problem in human mineral nutrition. It is mainly caused by imbalanced diets with low contents of bioavailable Zn. This is in particular a problem in populations depending on cereals such as wheat (Triticum aestivum L.) as a major source of this essential micronutrient element. Increasing Zn concentrations in wheat grains (biofortification) is therefore an important challenge. At the same time, increased uptake of the toxic heavy metal cadmium (Cd) must be prevented. Agronomic practises influence soil properties such as pH and soil organic carbon and thus also have an indirect effect on phytoavailable soil Zn and Cd concentrations and the uptake of these metals by wheat in addition to direct inputs with fertilizers and other amendments. This study investigated the effects of long-term organic matter management on the phytoavailability of soil Zn and Cd and their uptake by wheat on plots of two Swiss long-term field trials. In one trial (DOK), a farming system comparison trial established in 1978, we compared plots under conventional management with mineral fertilization either in combination or not with farmyard manure application to plots under biodynamic organic management and control plots with no fertilizer application. In the second trial (ZOFE), established in 1949, we compared different fertilizer regimes on conventionally managed plots, including plots with application of mineral fertilizers only, farmyard manure, or compost and control plots with no fertilizer application. Soil physico-chemical and biological properties were determined at the beginning of the growing season. Soil Zn and Cd availabilities were assessed by the Diffusive Gradients in Thin Films (DGT) method and by DTPA extraction before and after wheat cultivation. Additionally, various wheat yield components and element concentrations in shoots and grains were measured at harvest. In the ZOFE trial, soil Zn and Cd concentrations were lowest in the mineral fertilizer and highest in the farmyard manure treatments, where metal export via crop harvests and inputs through farmyard manure dominated soil metal mass balances in the long-term, respectively. DGT-available Zn and Cd correlated negatively with soil pH, total organic carbon and microbial biomass in both trials. They were lowest in the biodynamic and compost treatments and highest in the control treatments. In the ZOFE trial, wheat yields on mineral fertilized plots exceeded the other treatments by more than a factor of two. Cd concentrations in wheat shoots and grains showed a strong positive correlation with DGT-available soil Cd. They were lowest in biodynamic and compost treatments. In contrast, shoot and grain Zn concentrations correlated more closely with total and DTPA-extractable than with DGT-available soil Zn in the ZOFE trial and they poorly correlated with both Zn availability indicators in the DOK trial. Despite these differences, the study reveals that long-term organic matter management has an important influence on the availability of both elements in soil and their uptake by wheat.

  18. Griffon Helicopter Neck Strain Project: Part 1: Mission Function Task Analysis and Physical Demands Analysis Report. Part 2: Physical Demands Analysis Library

    DTIC Science & Technology

    2014-10-01

    nor limited to only rotary wing aircraft such as the CH-146 Griffon Helicopter. In fact, it is an international problem that militaries have been...Quality of Life Grant #1725981 and Military Health Program W3931-050513- 001/SV. Perry, C. E., Buhrman, J. R. and Knox, F. S. (1993). Biodynamic testing...a nd P D A Pa ge 1 24 V ig ne tte 1: L og ist ic s S up po rt a nd S ur ve ill an ce M iss io n Fl yi ng P ilo t: M is si on C lo

  19. Exploratory Research and Development Fund, FY 1990. Report on Lawrence Berkeley Laboratory

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

    Not Available

    1992-05-01

    The Lawrence Berkeley Laboratory Exploratory R&D Fund FY 1990 report is compiled from annual reports submitted by principal investigators following the close of the fiscal year. This report describes the projects supported and summarizes their accomplishments. It constitutes a part of an Exploratory R&D Fund (ERF) planning and documentation process that includes an annual planning cycle, projection selection, implementation, and review. The research areas covered in this report are: Accelerator and fusion research; applied science; cell and molecular biology; chemical biodynamics; chemical sciences; earth sciences; engineering; information and computing sciences; materials sciences; nuclear science; physics and research medicine and radiationmore » biophysics.« less

  20. A physiologically based biodynamic (PBBD) model for estragole DNA binding in rat liver based on in vitro kinetic data and estragole DNA adduct formation in primary hepatocytes

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

    Paini, Alicia, E-mail: alicia.paini@rdls.nestle.co; Nestle Research Center, PO Box 44, Lausanne; Punt, Ans

    2010-05-15

    Estragole has been shown to be hepatocarcinogenic in rodent species at high-dose levels. Translation of these results into the likelihood of formation of DNA adducts, mutation, and ultimately cancer upon more realistic low-dose exposures remains a challenge. Recently we have developed physiologically based biokinetic (PBBK) models for rat and human predicting bioactivation of estragole. These PBBK models, however, predict only kinetic characteristics. The present study describes the extension of the PBBK model to a so-called physiologically based biodynamic (PBBD) model predicting in vivo DNA adduct formation of estragole in rat liver. This PBBD model was developed using in vitro datamore » on DNA adduct formation in rat primary hepatocytes exposed to 1'-hydroxyestragole. The model was extended by linking the area under the curve for 1'-hydroxyestragole formation predicted by the PBBK model to the area under the curve for 1'-hydroxyestragole in the in vitro experiments. The outcome of the PBBD model revealed a linear increase in DNA adduct formation with increasing estragole doses up to 100 mg/kg bw. Although DNA adduct formation of genotoxic carcinogens is generally seen as a biomarker of exposure rather than a biomarker of response, the PBBD model now developed is one step closer to the ultimate toxic effect of estragole than the PBBK model described previously. Comparison of the PBBD model outcome to available data showed that the model adequately predicts the dose-dependent level of DNA adduct formation. The PBBD model predicts DNA adduct formation at low levels of exposure up to a dose level showing to cause cancer in rodent bioassays, providing a proof of principle for modeling a toxicodynamic in vivo endpoint on the basis of solely in vitro experimental data.« less

  1. A study of lagoonal and estuarine processes and artificial habitats in the area of the John F. Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Poonai, P.

    1974-01-01

    In order to study the influence of an artificial habitat of discarded automobile tires upon the biomass in and around it, three sites were selected in the Banana River, one of which will serve as a control and the other two as locations for small tire reefs. Measurements and correlation studies of the biomasses and the species indicate that the biodynamics of the sites are appreciably the same in the three cases, that there are probably adequate populations at the lower trophic levels, that there are perhaps reduced numbers of upper level carnivores, and that it is likely that small artificial havens can contribute to an increase in populations of certain species of gamefish.

  2. Evaluation of wheelchair back support crashworthiness: combination wheelchair back support surfaces and attachment hardware.

    PubMed

    Ha, D; Bertocci, G; Deemer, E; van Roosmalen, L; Karg, P

    2000-01-01

    Automotive seats are tested for compliance with federal motor vehicle safety standards (FMVSS) to assure safety during impact. Many wheelchair users rely upon their wheelchairs to serve as vehicle seats. However, the crashworthiness of these wheelchairs during impact is often unknown. This study evaluated the crashworthiness of five combinations of wheelchair back support surfaces and attachment hardware using a static test procedure simulating crash loading conditions. The crashworthiness was tested by applying a simulated rearward load to each seat-back system. The magnitude of the applied load was established through computer simulation and biodynamic calculations. None of the five tested wheelchair back supports withstood the simulated crash loads. All failures were associated with attachment hardware.

  3. Visual, Physiological, and Aesthetic Factors and Pitfalls in Asian Blepharoplasty

    PubMed Central

    Chen, William Pai-Dei

    2016-01-01

    Double eyelid surgery to create an upper-lid crease in Asian patients is one of the more popular aesthetic surgeries among people of Asian descent. Much has been written about the myriad methods, but little has been written about the underlying factors that predispose a patient to complications and suboptimal results. This article touches on some of the possible errors in placement of crease height in upper blepharoplasty and the pitfalls that can be associated with permanent placement of nondissolvable sutures that encircle the complex layers of the upper eyelid, as well as the ideal eyelid crease wound closure and its biodynamics. One should consider these factors in any form of upper eyelid procedure, as they are not merely applicable to upper blepharoplasty. PMID:26673576

  4. A Theory for the Roll-Ratchet Phenomenon in High Performance Aircraft

    NASA Technical Reports Server (NTRS)

    Hess, Ronald A.

    1997-01-01

    Roll-ratchet refers to a high frequency oscillation which can occur in pilot-in-the-loop control of roll attitude in high performance aircraft. The frequencies of oscillation are typically well beyond those associated with the more familiar pilot-induced oscillation. A structural model of the human pilot which has been employed to provide a unified theory for aircraft handling qualities and pilot-induced oscillations is employed here to provide a theory for the existence of roll-ratchet. It is hypothesized and demonstrated using the structural model that the pilot's inappropriate use of vestibular acceleration feedback can cause this phenomenon, a possibility which has been discussed previously by other researchers. The possible influence of biodynamic feedback on roll ratchet is also discussed.

  5. RTO Technical Publications: A Quarterly Listing

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This is a listing of recent unclassified RTO technical publications processed by the NASA Center for AeroSpace Information covering the period from July 1, 2005 to September 30, 2005; and available in the NASA Aeronautics and Space Database. Contents include: Aeroelastic Deformation: Adaptation of Wind Tunnel Measurement Concepts to Full-Scale Vehicle Flight Testing; Actively Controlling Buffet-Induced Excitations; Modelling and Simulation to Address NATO's New and Existing Military Requirements; Latency in Visionic Systems: Test Methods and Requirements; Personal Hearing Protection including Active Noise Reduction; Virtual Laboratory Enabling Collaborative Research in Applied Vehicle Technologies; A Method to Analyze Tail Buffet Loads of Aircraft; Particle Image Velocimetry Measurements to Evaluate the Effectiveness of Deck-Edge Columnar Vortex Generators on Aircraft Carriers; Introduction to Flight Test Engineering, Volume 14; Pathological Aspects and Associated Biodynamics in Aircraft Accident Investigation;

  6. Animating the biodynamics of soil thickness using process vector analysis: A dynamic denudation approach to soil formation

    USGS Publications Warehouse

    Johnson, D.L.; Domier, J.E.J.; Johnson, D.N.

    2005-01-01

    This paper expands the dynamic denudation framework of landscape evolution by providing new process insights and details on how soil and its signature morphological feature, the biomantle, form and function in the environment. We examine soils and their biomantles from disparate parts of the world, from the tropics through midlatitudes and hyperarid through perhumid, a range that exhibits varying environments for, and of, life. We then explicate the process pathways that cause soils to thicken and thin, and to even disappear, then reform. We do this by examining thickness relationships, where soil thickness stand biomantle thickness bt are functions of upbuilding u and deepening d minus removal r processes, hence st/bt=f(u+d-r). Upbuilding has two subsets, u1, which includes all exogenous (allochthonous-outside) mineral and/or organic inputs to the soil system, and u2, which includes all endogenous (autochthonous-in situ) processes and productions, including weathering. Exogenous u1 inputs include eolian and slopewash inputs (sedimentations) of mineral and organic materials, mass wasting accumulations and the like. Endogenous u2 processes and productions include the sum of in situ bioturbations, biosynthetic productions, organic accumulations, biovoid productions, weathering and volume increases caused by their sum. Endogenous upbuildings, which dominantly occur in the biomantle, are basically biodynamic bd processes and productions, hence u2=bd. Therefore, if exogenous upbuildings u1 are minimal or zero, then biomantle thickness bt is expressed by bt=f(u2-r) or bt=f(bd-r). Drawing on these relationships, we employ a graphic-conceptual device called process vector analysis in a digital animation (see supplementary materials or cf. https://netfiles.uiuc.edu/jdomier/www/temp/ biomantle.html) that illustrates the main pathways that form both Earth's soil and its unique epidermis, the biomantle. We then discuss the main elements of the animation using still frames that represent thickness turning points. We end by encouraging researchers, instructors and students to view Earth's landforms and soils as integrated dynamic entities that are constantly coevolving elements of a global subaerial-subaqueous continuum. ?? 2004 Elsevier B.V. All rights reserved.

  7. A biodynamic understanding of dietborne and waterborne Ag uptake from Ag NPs in the sediment-dwelling oligochaete, Tubifex tubifex

    USGS Publications Warehouse

    Tangaa, Stine Rosendal; Winther-Nielsen, Margrethe; Selck, Henriette; Croteau, Marie-Noele

    2018-01-01

    Metal nanoparticles (Me-NPs) are increasingly used in various products, such as inks and cosmetics, enhancing the likelihood of their release into aquatic environments. An understanding of the mechanisms controlling their bioaccumulation and ecotoxicity in aquatic biota will help support environmental risk assessment. Here we characterized unidirectional parameters for uptake and elimination of silver (Ag) in the sediment-dwelling oligochaete Tubifex tubifex after waterborne (0.01–47 nmol Ag/L) and dietborne (0.4–482 nmol Ag/g dw sed.) exposures to Ag NPs and AgNO3, respectively. Worms accumulated Ag from AgNO3more efficiently than from Ag NPs during waterborne exposure. The Ag uptake rate constants from water were 8.2 L/g/d for AgNO3 and 0.34 L/g/d for Ag NPs. Silver accumulated from both forms was efficiently retained in tissues, as no significant loss of Ag was detected after up to 20 days of depuration in clean media. High mortality (~50%) during depuration (i.e. after 17 days) was only observed for worms exposed to waterborne AgNO3 (3 nmol/L). Sediment exposures to both Ag forms resulted in low accumulation, i.e., the uptake rate constants were 0.002 and 0.005 g/g/d for AgNO3 and Ag NPs, respectively. Avoidance was only observed for worms exposed to sediment amended with AgNO3. Incorporation of the estimated rate constants into a biodynamic model predicted that sediment is likely the most important route of uptake for Ag in both forms in ecologically relevant aquatic environments. However, inference of bioavailability from our estimations of Ag assimilation efficiencies (AE) suggests that Ag (AE: 3–12% for AgNO3 and 0.1–0.8% for Ag NPs) is weakly bioavailable from sediment for this species. Thus, Ag amended to sediment as NPs might not pose greater problems than 'conventional' Ag for benthic organisms such as T. tubifex.

  8. Mechanical impedance and absorbed power of hand-arm under x(h)-axis vibration and role of hand forces and posture.

    PubMed

    Aldien, Yasser; Marcotte, Pierre; Rakheja, Subhash; Boileau, Paul-Emile

    2005-07-01

    The biodynamic responses of the hand-arm system under x(h)-axis vibration are investigated in terms of the driving point mechanical impedance (DPMI) and absorbed power in a laboratory study. For this purpose, seven healthy male subjects are exposed to two levels of random vibration in the 8-1,000 Hz frequency range, using three instrumented cylindrical handles of different diameters (30, 40 and 50 mm), and different combinations of grip (10, 30 and 50 N) and push (0, 25 and 50 N) forces. The experiments involve grasping the handle while adopting two different postures, involving elbow flexion of 90 degrees and 180 degrees, with wrist in the neutral position for both postures. The analyses of the results revealed peak DPMI magnitude and absorbed power responses near 25 Hz and 150 Hz, for majority of the test conditions considered. The frequency corresponding to the peak response increased with increasing hand forces. Unlike the absorbed power, the DPMI response was mostly observed to be insensitive to variations in the excitation magnitude. The handle diameter revealed obvious effects on the DPMI magnitude, specifically at frequencies above 250 Hz, which was not evident in the absorbed power due to relatively low velocity at higher frequencies. The influence of hand forces was also evident on the DPMI magnitude response particularly at frequencies. above 100 Hz, while the effect of hand-arm posture on the DPMI magnitude was nearly negligible. The magnitude of power absorbed within the hand and arm was observed to be strongly dependent upon the excitation level over the entire frequency range, while the influence of hand-arm posture on the total absorbed power was observed to be important. The effect of variations in the hand forces on the absorbed power was relatively small for the bent elbow posture, while an increase in either the grip or the push force coupled with the extended arm posture resulted in considerably higher energy absorption. The results suggested that the handle size, hand-arm posture and hand forces, produce coupled effect on the biodynamic response of the hand-arm system.

  9. Biodynamic study of americium-241 accumulation in the cytosol of the hepatopancreas of the lobster Homarus gammarus.

    PubMed

    Goudard, F; Paquet, F; Durand, J P; Milcent, M C; Germain, P; Pieri, J

    1994-08-01

    In the lobster, most of the radionuclides ingested with contaminated food are concentrated in the digestive gland. Americium-241 accumulation in the hepatopancreas of the lobster was studied during the digestive cycle. Fractionations of cytosols at different times after ingestion of radioactive preys were performed by gel permeation chromatography to determine the distribution of 241Am in the different macromolecular components. 241Am was associated with ferritin during the whole digestive cycle. This observation suggests a correlation between 241Am distribution pathways and iron metabolism. The distribution of 241Am present in the other cytosolic proteins followed two major steps of accumulation which may be correlated to the evolution of the two main cellular types playing an important role in the digestive cycle (B and R type cells).

  10. Poster Session

    NASA Technical Reports Server (NTRS)

    1997-01-01

    In this session, Poster Session, the discussion focuses on the following topics: Development of correlative measures for the assessment of attention and memory; Biodynamical Responses of the Crewmember Head/Neck System During Emergence Ejection; Fecundation in the Sky, a Ten Years Old Experiment in Microgravity; A Modified Botex Incubator as a Transport System For Developing Crickets into Space; Chromosomal Aberrations in Peripheral Lymphocytes of Cosmonauts and Astronauts after Space Flights; Method for Establishing Long term Bone Marrow; Cultures Under Microgravity Conditions Reproduction Under Simulated Weightlessness --Mammalian in vivo Experiments Under Suspension; Towards Human Movement Analysis Without the Use of Markers; Habitability Requirements For a Cogent Mars Mission; The Saucer Concept for Space Habitats; New Way In Modeling the Growth of the Organism; The Fractionation of Hydrogen and Oxygen Stable Isotopes By Life Support Systems of Space Station "MIR"; and Effect of Space Flight on Neutrophil Function.

  11. Leaching of plastic additives to marine organisms.

    PubMed

    Koelmans, Albert A; Besseling, Ellen; Foekema, Edwin M

    2014-04-01

    It is often assumed that ingestion of microplastics by aquatic species leads to increased exposure to plastic additives. However, experimental data or model based evidence is lacking. Here we assess the potential of leaching of nonylphenol (NP) and bisphenol A (BPA) in the intestinal tracts of Arenicola marina (lugworm) and Gadus morhua (North Sea cod). We use a biodynamic model that allows calculations of the relative contribution of plastic ingestion to total exposure of aquatic species to chemicals residing in the ingested plastic. Uncertainty in the most crucial parameters is accounted for by probabilistic modeling. Our conservative analysis shows that plastic ingestion by the lugworm yields NP and BPA concentrations that stay below the lower ends of global NP and BPA concentration ranges, and therefore are not likely to constitute a relevant exposure pathway. For cod, plastic ingestion appears to be a negligible pathway for exposure to NP and BPA. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Microcomputer based software for biodynamic simulation

    NASA Technical Reports Server (NTRS)

    Rangarajan, N.; Shams, T.

    1993-01-01

    This paper presents a description of a microcomputer based software package, called DYNAMAN, which has been developed to allow an analyst to simulate the dynamics of a system consisting of a number of mass segments linked by joints. One primary application is in predicting the motion of a human occupant in a vehicle under the influence of a variety of external forces, specially those generated during a crash event. Extensive use of a graphical user interface has been made to aid the user in setting up the input data for the simulation and in viewing the results from the simulation. Among its many applications, it has been successfully used in the prototype design of a moving seat that aids in occupant protection during a crash, by aircraft designers in evaluating occupant injury in airplane crashes, and by users in accident reconstruction for reconstructing the motion of the occupant and correlating the impacts with observed injuries.

  13. Mathematics reflecting sensorimotor organization.

    PubMed

    McCollum, Gin

    2003-02-01

    This review combines short presentations of several mathematical approaches that conceptualize issues in sensorimotor neuroscience from different perspectives and levels of analysis. The intricate organization of neural structures and sensorimotor performance calls for characterization using a variety of mathematical approaches. This review points out the prospects for mathematical neuroscience: in addition to computational approaches, there is a wide variety of mathematical approaches that provide insight into the organization of neural systems. By starting from the perspective that provides the greatest clarity, a mathematical approach avoids specificity that is inaccurate in characterizing the inherent biological organization. Approaches presented include the mathematics of ordered structures, motion-phase space, subject-coincident coordinates, equivalence classes, topological biodynamics, rhythm space metric, and conditional dynamics. Issues considered in this paper include unification of levels of analysis, response equivalence, convergence, relationship of physics to motor control, support of rhythms, state transitions, and focussing on low-dimensional subspaces of a high-dimensional sensorimotor space.

  14. Differences in Otolith and Abdominal Viscera Graviceptor Dynamics: Implications for Motion Sickness and Perceived Body Position

    NASA Technical Reports Server (NTRS)

    vonGierke, Henning E.; Parker, Donald E.

    1993-01-01

    Human graviceptors, located in the trunk by Mittelstaedt probably transduce acceleration by abdominal viscera motion. As demonstrated previously in biodynamic vibration and impact tolerance research the thoraco-abdominal viscera exhibit a resonance at 4 to 6 Hz. Behavioral observations and mechanical models of otolith graviceptor response indicate a phase shift increasing with frequency between 0.01 and O.5 Hz. Consequently the potential exists for intermodality sensory conflict between vestibular and visceral graviceptor signals at least at the mechanical receptor level. The frequency range of this potential conflict corresponds with the primary frequency range for motion sickness incidence in transportation, in subjects rotated about Earth-horizontal axes (barbecue spit stimulation) and in periodic parabolic flight microgravity research and also for erroneous perception of vertical oscillations in helicopters. We discuss the implications of this hypothesis for previous self motion perception research and suggestions for various future studies.

  15. Apparent mass of the human body in the vertical direction: Effect of a footrest and a steering wheel

    NASA Astrophysics Data System (ADS)

    Toward, M. G. R.; Griffin, M. J.

    2010-04-01

    The apparent mass of the seated human body influences the vibration transmitted through a car seat. The apparent mass of the body is known to be influenced by sitting posture but the influence of the position of the hands and the feet is not well understood. This study was designed to quantify the influence of steering wheel location and the position of a footrest on the vertical apparent mass of the human body. The influences of the forces applied by the hands to a steering wheel and by the feet to a footrest were also investigated. Twelve subjects were exposed to whole-body vertical random vibration (1.0 m s -2 rms over the frequency range 0.13-40.0 Hz) while supported by a rigid seat with a backrest reclined to 15°. The apparent mass of the body was measured with five horizontal positions and three vertical positions of a steering wheel and also with hands in the lap, and with five horizontal positions of a footrest. The influence of five forward forces (0, 50, 100, 150, 200 N) applied separately to the 'steering wheel' and the footrest were also investigated as well as a 'no backrest' condition. With their hands in their laps, subjects exhibited a resonance around 6.7 Hz, compared to 4.8 Hz when sitting upright with no backrest. In the same posture holding a steering wheel, the mass supported on the seat surface decreased and there was an additional resonance at 4 Hz. Moving the steering wheel away from the body reduced the apparent mass at the primary resonance frequency and increased the apparent mass around the 4 Hz resonance. As the feet moved forward, the mass supported on the seat surface decreased, indicating that the backrest and footrest supported a greater proportion of the subject weight. Applying force to either the steering wheel or the footrest reduced the apparent mass at resonance and decreased the mass supported on the seat surface. It is concluded that the positions and contact conditions of the hands and the feet affect the biodynamic response of the body in a car driving posture. As the biodynamic response influences the vibration transmitted through seats, these factors should be considered in dynamic models of vehicle seating.

  16. Materials dispersion and biodynamics project research

    NASA Technical Reports Server (NTRS)

    Lewis, Marian L.

    1992-01-01

    The Materials Dispersion and Biodynamics Project (MDBP) focuses on dispersion and mixing of various biological materials and the dynamics of cell-to-cell communication and intracellular molecular trafficking in microgravity. Research activities encompass biomedical applications, basic cell biology, biotechnology (products from cells), protein crystal development, ecological life support systems (involving algae and bacteria), drug delivery (microencapsulation), biofilm deposition by living organisms, and hardware development to support living cells on Space Station Freedom (SSF). Project goals are to expand the existing microgravity science database through experiments on sounding rockets, the Shuttle, and COMET program orbiters and to evolve,through current database acquisition and feasibility testing, to more mature and larger-scale commercial operations on SSF. Maximized utilization of SSF for these science applications will mean that service companies will have a role in providing equipment for use by a number of different customers. An example of a potential forerunner of such a service for SSF is the Materials Dispersion Apparatus (MDA) 'mini lab' of Instrumentation Technology Associates, Inc. (ITA) in use on the Shuttle for the Commercial MDAITA Experiments (CMIX) Project. The MDA wells provide the capability for a number of investigators to perform mixing and bioprocessing experiments in space. In the area of human adaptation to microgravity, a significant database has been obtained over the past three decades. Some low-g effects are similar to Earth-based disorders (anemia, osteoporosis, neuromuscular diseases, and immune system disorders). As new information targets potential profit-making processes, services and products from microgravity, commercial space ventures are expected to expand accordingly. Cooperative CCDS research in the above mentioned areas is essential for maturing SSF biotechnology and to ensure U.S. leadership in space technology. Currently, the MDBP conducts collaborative research with investigators at the Rockefeller University, National Cancer Institute, and the Universities of California, Arizona, and Alabama in Birmingham. The growing database from these collaborations provides fundamental information applicable to development of cell products, manipulation of immune cell response, bone cell growth and mineralization, and other processes altered by low-gravity. Contacts with biotechnology and biopharmaceutical companies are being increased to reach uninformed potential SSF users, provide access through the CMDS to interested users for feasibility studies, and to continue active involvement of current participants. We encourage and actively seek participation of private sector companies, and university and government researchers interested in biopharmaceuticals, hardware development and fundamental research in microgravity.

  17. Unobtrusive Behavioral and Activity-Related Multimodal Biometrics: The ACTIBIO Authentication Concept

    PubMed Central

    Drosou, A.; Ioannidis, D.; Moustakas, K.; Tzovaras, D.

    2011-01-01

    Unobtrusive Authentication Using ACTIvity-Related and Soft BIOmetrics (ACTIBIO) is an EU Specific Targeted Research Project (STREP) where new types of biometrics are combined with state-of-the-art unobtrusive technologies in order to enhance security in a wide spectrum of applications. The project aims to develop a modular, robust, multimodal biometrics security authentication and monitoring system, which uses a biodynamic physiological profile, unique for each individual, and advancements of the state of the art in unobtrusive behavioral and other biometrics, such as face, gait recognition, and seat-based anthropometrics. Several shortcomings of existing biometric recognition systems are addressed within this project, which have helped in improving existing sensors, in developing new algorithms, and in designing applications, towards creating new, unobtrusive, biometric authentication procedures in security-sensitive, Ambient Intelligence environments. This paper presents the concept of the ACTIBIO project and describes its unobtrusive authentication demonstrator in a real scenario by focusing on the vision-based biometric recognition modalities. PMID:21380485

  18. Pulsatile crizotinib treatment for brain metastasis in a patient with non-small-cell lung cancer.

    PubMed

    Wang, S; Chen, J; Xie, Z; Xia, L; Luo, W; Li, J; Li, Q; Yang, Z

    2017-10-01

    Anaplastic lymphoma kinase (ALK)-rearranged non-small-cell lung cancer (NSCLC) is a distinct subtype with patients showing peculiar clinicopathological features and dramatic responses to the ALK tyrosine kinase inhibitor crizotinib. Patients with this cancer variant have a dismal prognosis and limited treatment options when it has progressed to intracranial metastasis because of inadequate drug penetration into the central nervous system (CNS). Factors associated with response to TKI therapy have been reported to include pharmacokinetic and biodynamic resistance phenomena. In our NSCLC patient with multiple intracranial metastases, we administered high-dose pulsatile crizotinib therapy (1000 mg/d) on a one-day-on/one-day-off basis. A significant central nervous system (CNS) response was achieved, and time to neurological progression was prolonged to 6 months. High-dose pulsatile therapy may be an effective dosing strategy for crizotinib in NSCLC showing progression to metastasis in the brain. © 2017 John Wiley & Sons Ltd.

  19. Unobtrusive behavioral and activity-related multimodal biometrics: The ACTIBIO Authentication concept.

    PubMed

    Drosou, A; Ioannidis, D; Moustakas, K; Tzovaras, D

    2011-03-01

    Unobtrusive Authentication Using ACTIvity-Related and Soft BIOmetrics (ACTIBIO) is an EU Specific Targeted Research Project (STREP) where new types of biometrics are combined with state-of-the-art unobtrusive technologies in order to enhance security in a wide spectrum of applications. The project aims to develop a modular, robust, multimodal biometrics security authentication and monitoring system, which uses a biodynamic physiological profile, unique for each individual, and advancements of the state of the art in unobtrusive behavioral and other biometrics, such as face, gait recognition, and seat-based anthropometrics. Several shortcomings of existing biometric recognition systems are addressed within this project, which have helped in improving existing sensors, in developing new algorithms, and in designing applications, towards creating new, unobtrusive, biometric authentication procedures in security-sensitive, Ambient Intelligence environments. This paper presents the concept of the ACTIBIO project and describes its unobtrusive authentication demonstrator in a real scenario by focusing on the vision-based biometric recognition modalities.

  20. Apparent mass matrix of standing subjects exposed to multi-axial whole-body vibration.

    PubMed

    Tarabini, Marco; Solbiati, Stefano; Saggin, Bortolino; Scaccabarozzi, Diego

    2016-08-01

    This paper describes the experimental characterisation of the apparent mass matrix of eight male subjects in standing position and the identification of nonlinearities under both mono-axial and dual-axis whole-body vibration. The nonlinear behaviour of the response was studied using the conditioned response techniques considering models of increasing complexity. Results showed that the cross-axis terms are comparable to the diagonal terms. The contribution of the nonlinear effects are minor and can be endorsed to the change of modal parameters during the tests. The nonlinearity generated by the vibration magnitude is more evident in the subject response, since magnitude-dependent effects in the population are overlaid by the scatter in the subjects' biometric data. The biodynamic response is influenced by the addition of a secondary vibration axis and, in case of dual-axis vibrations, the overall magnitude has a marginal contribution. Practitioner Summary: We have measured both the diagonal and cross-axis elements of the apparent mass matrix. The effect of nonlinearities and the simultaneous presence of vibration along two axes are smaller than the inter-subject variability.

  1. Measurement and modelling of the y-direction apparent mass of sitting human body-cushioned seat system

    NASA Astrophysics Data System (ADS)

    Stein, George Juraj; Múčka, Peter; Hinz, Barbara; Blüthner, Ralph

    2009-04-01

    Laboratory tests were conducted using 13 male subjects seated on a cushioned commercial vehicle driver's seat. The hands gripped a mock-up steering wheel and the subjects were in contact with the lumbar region of the backrest. The accelerations and forces in the y-direction were measured during random lateral whole-body vibration with a frequency range between 0.25 and 30 Hz, vibration magnitudes 0.30, 0.98, and 1.92 m s -2 (unweighted root mean square (rms)). Based on these laboratory measurements, a linear multi-degree-of-freedom (mdof) model of the seated human body and cushioned seat in the lateral direction ( y-axis) was developed. Model parameters were identified from averaged measured apparent mass values (modulus and phase) for the three excitation magnitudes mentioned. A preferred model structure was selected from four 3-dof models analysed. The mean subject parameters were identified. In addition, identification of each subject's apparent mass model parameters was performed. The results are compared with previous studies. The developed model structure and the identified parameters can be used for further biodynamical research in seating dynamics.

  2. Digital holography of intracellular dynamics to probe tissue physiology.

    PubMed

    Merrill, Daniel; An, Ran; Turek, John; Nolte, David D

    2015-01-01

    Digital holography provides improved capabilities for imaging through dense tissue. Using a short-coherence source, the digital hologram recorded from backscattered light performs laser ranging that maintains fidelity of information acquired from depths much greater than possible by traditional imaging techniques. Biodynamic imaging (BDI) is a developing technology for live-tissue imaging of up to a millimeter in depth that uses the hologram intensity fluctuations as label-free image contrast and can study tissue behavior in native microenvironments. In this paper BDI is used to investigate the change in adhesion-dependent tissue response in 3D cultures. The results show that increasing density of cellular adhesions slows motion inside tissue and alters the response to cytoskeletal drugs. A clear signature of membrane fluctuations was observed in mid-frequencies (0.1-1 Hz) and was enhanced by the application of cytochalasin-D that degrades the actin cortex inside the cell membrane. This enhancement feature is only observed in tissues that have formed adhesions, because cell pellets initially do not show this signature, but develop this signature only after incubation enables adhesions to form.

  3. Uptake dynamics of inorganic mercury and methylmercury by the earthworm Pheretima guillemi.

    PubMed

    Dang, Fei; Zhao, Jie; Zhou, Dongmei

    2016-02-01

    Mercury uptake dynamics in the earthworm Pheretima guillemi, including the dissolved uptake rate constant (ku) from pore-water and assimilation efficiencies (AEs) from mercury-contaminated soil, was quantified in this study. Dissolved uptake rate constants were 0.087 and 0.553 L g(-1) d(-1) for inorganic mercury (IHg) and methylmercury (MeHg), respectively. Assimilation efficiency of IHg in field-contaminated soil was 7.2%, lower than 15.4% of spiked soil. In contrast, MeHg exhibited comparable AEs for both field-contaminated and spiked soil (82.4-87.2%). Within the framework of biodynamic model, we further modelled the exposure pathways (dissolved exposure vs soil ingestion) to source the accumulated mercury in Pheretima guillemi. The model showed that the relative importance of soil ingestion to mercury bioaccumulation depended largely on mercury partitioning coefficients (K(d)), and was also influenced by soil ingestion rate of earthworms. In the examined field-contaminated soil, almost (>99%) accumulated IHg and MeHg was predicted to derive from soil ingestion. Therefore, soil ingestion should be carefully considered when assessing mercury exposure risk to earthworms. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. A New Skin Tensiometer Device: Computational Analyses To Understand Biodynamic Excisional Skin Tension Lines.

    PubMed

    Paul, Sharad P; Matulich, Justin; Charlton, Nick

    2016-07-25

    One of the problems in planning cutaneous surgery is that human skin is anisotropic, or directionally dependent. Indeed, skin tension varies between individuals and at different body sites. Many a surgeon has tried to design different devices to measure skin tension to help plan excisional surgery, or to understand wound healing. However, many of the devices have been beset with problems due to many confounding variables - differences in technical ability, material (sutures) used and variability between different users. We describe the development of a new skin tensiometer that overcomes many historical technical issues. A new skin tension measuring device is presented here. It was designed to be less user-dependent, more reliable and usable on different bodily sites. The design and computational optimizations are discussed. Our skin tensiometer has helped understand the differences between incisional and excisional skin lines. Langer, who pioneered the concept of skin tension lines, created incisional lines that differ from lines caused by forces that need to be overcome when large wounds are closed surgically (excisional tension). The use of this innovative device has led to understanding of skin biomechanics and best excisional skin tension (BEST) lines.

  5. A New Skin Tensiometer Device: Computational Analyses To Understand Biodynamic Excisional Skin Tension Lines

    PubMed Central

    Paul, Sharad P.; Matulich, Justin; Charlton, Nick

    2016-01-01

    One of the problems in planning cutaneous surgery is that human skin is anisotropic, or directionally dependent. Indeed, skin tension varies between individuals and at different body sites. Many a surgeon has tried to design different devices to measure skin tension to help plan excisional surgery, or to understand wound healing. However, many of the devices have been beset with problems due to many confounding variables - differences in technical ability, material (sutures) used and variability between different users. We describe the development of a new skin tensiometer that overcomes many historical technical issues. A new skin tension measuring device is presented here. It was designed to be less user-dependent, more reliable and usable on different bodily sites. The design and computational optimizations are discussed. Our skin tensiometer has helped understand the differences between incisional and excisional skin lines. Langer, who pioneered the concept of skin tension lines, created incisional lines that differ from lines caused by forces that need to be overcome when large wounds are closed surgically (excisional tension). The use of this innovative device has led to understanding of skin biomechanics and best excisional skin tension (BEST) lines. PMID:27453542

  6. The Influence of Neck Muscle Activation on Head and Neck Injuries of Occupants in Frontal Impacts.

    PubMed

    Li, Fan; Lu, Ronggui; Hu, Wei; Li, Honggeng; Hu, Shiping; Hu, Jiangzhong; Wang, Haibin; Xie, He

    2018-01-01

    The aim of the present paper was to study the influence of neck muscle activation on head and neck injuries of vehicle occupants in frontal impacts. A mixed dummy-human finite element model was developed to simulate a frontal impact. The head-neck part of a Hybrid III dummy model was replaced by a well-validated head-neck FE model with passive and active muscle characteristics. The mixed dummy-human FE model was validated by 15 G frontal volunteer tests conducted in the Naval Biodynamics Laboratory. The effects of neck muscle activation on the head dynamic responses and neck injuries of occupants in three frontal impact intensities, low speed (10 km/h), medium speed (30 km/h), and high speed (50 km/h), were studied. The results showed that the mixed dummy-human FE model has good biofidelity. The activation of neck muscles can not only lower the head resultant acceleration under different impact intensities and the head angular acceleration in medium- and high-speed impacts, thereby reducing the risks of head injury, but also protect the neck from injury in low-speed impacts.

  7. Human response to vibration stress in Japanese workers: lessons from our 35-year studies A narrative review

    PubMed Central

    MATOBA, Tsunetaka

    2015-01-01

    The occupational uses with vibratory tools or vehicles provoked health disorders of users. We reviewed narratively our articles of 35 yr studies and their related literatures, and considered the pathophysiology of the hand-arm vibration disorders. Concerning the risk factors of health impairments in workers with vibratory tools, there are two conflicting schools of the researchers: The peripheral school emphasizes that vibration only makes predominant impairments on hands and arms, showing typically Raynaud’s phenomenon in the fingers. In the systemic school, the health disorders are produced by combination with vibration, noise and working environment, namely vibratory work itself, leading to diversified symptoms and signs in relation to systemic impairments. Our 35 yr studies have evidently supported the systemic school, including disorders of the central and autonomic nervous systems. The genesis is vibratory work itself, including vibration, noise, cold working environment, ergonomic and biodynamic conditions, and emotional stress in work. Because the health disorders yield in the whole body, the following measures would contribute to the prevention of health impairments: the attenuation of vibration and noise generated form vibratory machines and the regulations on operating tool hours. In conclusion, this occupational disease results from systemic impairments due to long-term occupational work with vibratory tools. PMID:26460379

  8. Perception and biodynamics in unalerted precrash response.

    PubMed

    McGehee, Daniel V; Carsten, Oliver M J

    2010-01-01

    This research seeks to better understand unalerted driver response just prior to a serious vehicle crash. Few studies have been able to view a crash from the inside-with a camera focused on the driver and occupants. Four studies are examined: 1) a high-fidelity simulator study with an unalerted intersection incursion crash among 107 drivers; 2) four crashes from the Virginia Tech Transportation Institute (VTTI) 100 car study; 3) 58 crashes from vehicles equipped with an event triggered video recorder; and 4) a custom-designed high-fidelity simulator experiment that examined unalerted driver response to a head-on crash with a heavy truck. Analyses concentrate on decomposing driver perception, action, facial and postural changes with a focus on describing the neurophysiologic mechanisms designed to respond to danger. Results indicate that drivers involved in severe crashes generally have preview that an impact is about to occur. They respond first with vehicle control inputs (accelerator pedal release) along with facial state changes and withdrawal of the head back towards the head restraint. These responses frequently occur almost simultaneously, providing safety system designers with a number of reliable driver performance measures to monitor. Understanding such mechanisms may assist future advanced driver assistance systems (ADAS), advanced restraints, model development of advanced anthropomorphic test dummies (ATDs), injury prediction and the integration of active and passive safety systems.

  9. Psychodynamic and biodynamic analysis of treatment of outlet obstructive constipation (OOC) using Procedure for Prolapse and Hemorrhoids (PPH).

    PubMed

    Qin, Zhensheng; Pang, Liqun; Dai, Weijie; Yan, Wei; Zhang, Jian; Zhao, Yao; Li, Qianjun; Wu, Kun; Zhou, Baoxiang

    2015-07-01

    To discuss the possible pathogenesis of outlet obstructive constipation (OOC) and identify the theoretical basis of the Procedure for Prolapse and Hemorrhoids (PPH) used to treat outlet obstructive constipation (OOC). 19 patients diagnosed with outlet obstructive constipation (OOC) form the case group, and 9 healthy volunteers form the control group. Patients, before and after operation, and the control group, were equally given such tests as Hamilton Depression Rating Scale (HAMD), Hamilton Anxiety Scale (HAMA) and anorectal dynamics. No significant difference in the functional lengths of anal canals was found between all groups (F = 0.98, p = 0.41). The minimum perception threshold, maximum tolerance threshold, and rectal defecation threshold of Group A, of 15 days after operation, were equally lower than those before operation, and than the control group (P < 0.05). These thresholds rebounded significantly in Group B 90 days after operation. Mentally, HAMA (F = 23.75, p = 0.00) and HAMD (F = 20.99, p = 0.00) total scores, after operation, were equally decreased first and then rebounded. Patients with outlet obstructive constipation (OOC) are subject to anorectal dynamic disorders as well as mental and psychological disorders, which can be remarkably improved using the Procedure for Prolapse and Hemorrhoids (PPH). Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Role of cellular adhesions in tissue dynamics spectroscopy

    NASA Astrophysics Data System (ADS)

    Merrill, Daniel A.; An, Ran; Turek, John; Nolte, David

    2014-02-01

    Cellular adhesions play a critical role in cell behavior, and modified expression of cellular adhesion compounds has been linked to various cancers. We tested the role of cellular adhesions in drug response by studying three cellular culture models: three-dimensional tumor spheroids with well-developed cellular adhesions and extracellular matrix (ECM), dense three-dimensional cell pellets with moderate numbers of adhesions, and dilute three-dimensional cell suspensions in agarose having few adhesions. Our technique for measuring the drug response for the spheroids and cell pellets was biodynamic imaging (BDI), and for the suspensions was quasi-elastic light scattering (QELS). We tested several cytoskeletal chemotherapeutic drugs (nocodazole, cytochalasin-D, paclitaxel, and colchicine) on three cancer cell lines chosen from human colorectal adenocarcinoma (HT-29), human pancreatic carcinoma (MIA PaCa-2), and rat osteosarcoma (UMR-106) to exhibit differences in adhesion strength. Comparing tumor spheroid behavior to that of cell suspensions showed shifts in the spectral motion of the cancer tissues that match predictions based on different degrees of cell-cell contacts. The HT-29 cell line, which has the strongest adhesions in the spheroid model, exhibits anomalous behavior in some cases. These results highlight the importance of using three-dimensional tissue models in drug screening with cellular adhesions being a contributory factor in phenotypic differences between the drug responses of tissue and cells.

  11. The Golden Spiral Flap: A New Flap Design that Allows for Closure of Larger Wounds under Reduced Tension – How Studying Nature’s Own Design Led to the Development of a New Surgical Technique

    PubMed Central

    Paul, Sharad P.

    2016-01-01

    This paper details the study of biodynamic excisional skin tension lines on the scalp and the development of a new flap technique for closure of scalp wounds. Recently, a study by this author, on pigskin, replicated whorls by placing tissue under rapid stretch using saline tissue expanders, by recreating rapid dermo-epidermal shear of skin – thereby concluding that the golden spiral pattern is nature’s own pattern for rapid expansion. Given the relationship between tissue expansion and stretch has been shown to cause deformation gradients that have both elastic and growth factors, the author set out to test the hypothesis that a golden spiral pattern therefore would be more efficient at closing wounds under less tension when compared with standard semicircular rotational flap patterns. The author conducted a series of experiments, both on pigskin (to first confirm the hypothesis, using a recently developed computerized tensiometer) and later a clinical study. This paper presents a new random pivotal flap technique for skin closures on the head and neck: the golden spiral flap. Biomechanics, planning, and advantages of this new flap are described in this paper. PMID:27900320

  12. Bioturbation delays attenuation of DDT by clean sediment cap but promotes sequestration by thin-layered activated carbon.

    PubMed

    Lin, Diana; Cho, Yeo-Myoung; Werner, David; Luthy, Richard G

    2014-01-21

    The effects of bioturbation on the performance of attenuation by sediment deposition and activated carbon to reduce risks from DDT-contaminated sediment were assessed for DDT sediment-water flux, biouptake, and passive sampler (PE) uptake in microcosm experiments with a freshwater worm, Lumbriculus variegatus. A thin-layer of clean sediment (0.5 cm) did not reduce the DDT flux when bioturbation was present, while a thin (0.3 cm) AC cap was still capable of reducing the DDT flux by 94%. Bioturbation promoted AC sequestration by reducing the 28-day DDT biouptake (66%) and DDT uptake into PE (>99%) compared to controls. Bioturbation further promoted AC-sediment contact by mixing AC particles into underlying sediment layers, reducing PE uptake (55%) in sediment compared to the AC cap without bioturbation. To account for the observed effects from bioturbation, a mass transfer model together with a biodynamic model were developed to simulate DDT flux and biouptake, respectively, and models confirmed experimental results. Both experimental measurements and modeling predictions imply that thin-layer activated carbon placement on sediment is effective in reducing the risks from contaminated sediments in the presence of bioturbation, while natural attenuation process by clean sediment deposition may be delayed by bioturbation.

  13. [Time and temporality in gerontology and the ontologic privation theory of biological aging].

    PubMed

    Kment, A

    1989-01-01

    We have seen how our conception of time has changed in the course of the years. Up to the beginning of this century people believed in absolute time. According to today's views, time and temporality do not consist of a continuous flow of time successions, as generally assumed, the essence lies in the inner character of events. Therefore, in order to comprehend the true nature of time and temporality in gerontology, we must pay particular attention to the constitutional structures of events or happenings. Here we must comprehend the implication of an ontological change and the constitutions of time as metaphysical structure. Time and temporality are measured in happenings and processes, and not vice versa. Whitehead, showed that we are concerned with an ontological interpretation of time and temporality. The biodynamics of an individual reveal the largely autonomous structure and bionomy of the processes of life, as well as the continuous interaction and shifts of the biological cycles of formation, change, and decline. The ontological privation of biological aging and death are just as much a part of life as conception and birth. Only what lives can mature, age, and die. The imminent "purpose" of the biological aging of the individual is dying and death, i.e., the return home into "absolute being".

  14. The Impact of Structural Vibration on Flying Qualities of a Supersonic Transport

    NASA Technical Reports Server (NTRS)

    Raney, David L.; Jackson, E. Bruce; Buttrill, Carey S.; Adams, William M.

    2001-01-01

    A piloted simulation experiment has been conducted in the NASA Langley Visual/Motion Simulator facility to address the impact of dynamic aeroelastic effects on flying qualities of a supersonic transport. The intent of this experiment was to determine the effectiveness of several measures that may be taken to reduce the impact of aircraft flexibility on piloting tasks. Potential solutions that were examined included structural stiffening, active vibration suppression, and elimination of visual cues associated with the elastic modes. A series of parametric configurations was evaluated by six test pilots for several types of maneuver tasks. During the investigation, several incidents were encountered in which cockpit vibrations due to elastic modes fed back into the control stick through involuntary motions of the pilot's upper body and arm. The phenomenon, referred to as biodynamic coupling, is evidenced by a resonant peak in the power spectrum of the pilot's stick inputs at a structural mode frequency. The results of the investigation indicate that structural stiffening and compensation of the visual display were of little benefit in alleviating the impact of elastic dynamics on the piloting tasks, while increased damping and elimination of control-effector excitation of the lowest frequency modes offered great improvements when applied in sufficient degree.

  15. Arbuscular mycorrhizal fungal spores host bacteria that affect nutrient biodynamics and biocontrol of soil-borne plant pathogens

    PubMed Central

    Cruz, Andre Freire; Ishii, Takaaki

    2012-01-01

    Summary The aim of this research was to isolate and characterize bacteria from spores of arbuscular mycorrhizal fungi (AMF). We designated these bacteria ‘probable endobacteria’ (PE). Three bacterial strains were isolated from approximately 500 spores of Gigaspora margarita (Becker and Hall) using a hypodermic needle (diameter, 200 μm). The bacteria were identified by morphological methods and on the basis of ribosomal gene sequences as Bacillus sp. (KTCIGM01), Bacillus thuringiensis (KTCIGM02), and Paenibacillus rhizospherae (KTCIGM03). We evaluated the effect of these probable endobacteria on antagonistic activity to the soil-borne plant pathogens (SBPPs) Fusarium oxysporum f. sp. lactucae MAFF 744088, Rosellinia necatrix, Rhizoctonia solani MAFF 237426, and Pythium ultimum NBRC 100123. We also tested whether these probable endobacteria affected phosphorus solubilization, ethylene production, nitrogenase activity (NA), and stimulation of AMF hyphal growth. In addition, fresh samples of spores and hyphae were photographed using an in situ scanning electron microscope (SEM) (Quanta 250FEG; FEI Co., Japan). Bacterial aggregates (BAs), structures similar to biofilms, could be detected on the surface of hyphae and spores. We demonstrate that using extraction with an ultrathin needle, it is possible to isolate AMF-associated bacterial species that are likely derived from inside the fungal spores. PMID:23213368

  16. Effects of elastic seats on seated body apparent mass responses to vertical whole body vibration.

    PubMed

    Dewangan, K N; Rakheja, S; Marcotte, Pierre; Shahmir, A

    2015-01-01

    Apparent mass (AM) responses of the body seated with and without a back support on three different elastic seats (flat and contoured polyurethane foam (PUF) and air cushion) and a rigid seat were measured under three levels of vertical vibration (overall rms acceleration: 0.25, 0.50 and 0.75 m/s(2)) in the 0.5 to 20 Hz range. A pressure-sensing system was used to capture biodynamic force at the occupant-seat interface. The results revealed strong effects of visco-elastic and vibration transmissibility characteristics of seats on AM. The response magnitudes with the relatively stiff air seat were generally higher than those with the PUF seats except at low frequencies. The peak magnitude decreased when sitting condition was changed from no back support to a vertical support; the reduction however was more pronounced with the air seat. Further, a relatively higher frequency shift was evident with soft seat compared with stiff elastic seat with increasing excitation. The effects of visco-elastic properties of the body-seat interface on the apparent mass responses of the seated body are measured under vertical vibration. The results show considerable effects of the coupling stiffness on the seated body apparent mass, apart from those of excitation magnitude and back support.

  17. Performance effects of mounting a helmet-mounted display on the ANVIS mount of the HGU-56P helmet

    NASA Astrophysics Data System (ADS)

    Harding, Thomas H.; Martin, John S.; Rash, Clarence E.

    2006-05-01

    The U.S. Army, under the auspices of the Air Warrior Product Office, is developing a modular helmet-mounted display (HMD) for four aircraft series within its helicopter fleet. A design consideration is mounting the HMDs to the HGU- 56P Aviator's Night Vision Imaging System (ANVIS) mount. This particular mount is being considered, presumably due to its inherent cost savings, as the mount is already part of the helmet. Mounting the HMD in this position may have consequences for the daylight performance of these HMDs, as well as increasing the forward weight of the HMD. The latter would have consequences for helmet weight and center-of-mass biodynamic issues. Calculations were made of the increased luminance needed as a consequence of mounting the HMD in front of an HGU-56P tinted visor as opposed to mounting it behind the visor. By mounting in front of the helmet's visor, the HMD's light output will be filtered as light coming from the outside world. Special consideration then would have to be given to the HMD's light source selection process, as not to select a source that would differentially reduce luminance by a mounted visor (e.g., laser protection visors) compared to the ambient light in the aviator's field-of-view.

  18. Human response to vibration stress in Japanese workers: lessons from our 35-year studies A narrative review.

    PubMed

    Matoba, Tsunetaka

    2015-01-01

    The occupational uses with vibratory tools or vehicles provoked health disorders of users. We reviewed narratively our articles of 35 yr studies and their related literatures, and considered the pathophysiology of the hand-arm vibration disorders. Concerning the risk factors of health impairments in workers with vibratory tools, there are two conflicting schools of the researchers: The peripheral school emphasizes that vibration only makes predominant impairments on hands and arms, showing typically Raynaud's phenomenon in the fingers. In the systemic school, the health disorders are produced by combination with vibration, noise and working environment, namely vibratory work itself, leading to diversified symptoms and signs in relation to systemic impairments. Our 35 yr studies have evidently supported the systemic school, including disorders of the central and autonomic nervous systems. The genesis is vibratory work itself, including vibration, noise, cold working environment, ergonomic and biodynamic conditions, and emotional stress in work. Because the health disorders yield in the whole body, the following measures would contribute to the prevention of health impairments: the attenuation of vibration and noise generated form vibratory machines and the regulations on operating tool hours. In conclusion, this occupational disease results from systemic impairments due to long-term occupational work with vibratory tools.

  19. Nutrient changes and biodynamics of Eisenia fetida during vermicomposting of water lettuce (Pistia sp.) biomass: a noxious weed of aquatic system.

    PubMed

    Suthar, Surindra; Pandey, Bhawna; Gusain, Rita; Gaur, Rubia Zahid; Kumar, Kapil

    2017-01-01

    This paper reports the results of vermicomposting of water lettuce biomass (WL) spiked with cow dung at ratios of 20, 40, 60, and 80 % employing Eisenia fetida. A total of four treatments were established and changes in chemical properties of mixtures were observed. Vermicomposting caused a decrease in pH, TOC, volatile solids, and C/N ratio by 1.01-1.08-fold, 0.85-0.92-fold, 0.94-0.96-fold, 0.56-0.70-fold, respectively, but increase in EC, tot N, tot P, tot K, tot Ca, tot Zn, tot Fe, and tot Cu, by 1.19-1.42-fold, 1.33-1.68-fold, 1.38-1.69-fold, 1.13-1.24-fold, 1.04-1.11-fold, 1.16-1.37-fold, 1.05-1.113-fold, 1.10-1.27-fold, respectively. Overall, the treatment with 60-80 % of WL showed the maximum decomposition and mineralization rates. The earthworm showed the growth and reproduction rate in considerable ranges in all treatment setups but setups with 60-80 % WL proportion exhibited the optimum results. Results reveal that biomass of water lettuce can be utilized effectively for production of valuable manure through vermicomposting system.

  20. Biodynamic Performance of Hyaluronic Acid versus Synovial fluid of the Knee for Osteoarthritic Therapy

    PubMed Central

    Corvelli, Michael; Che, Bernadette; Saeui, Christopher; Singh, Anirudha; Elisseeff, Jennifer

    2015-01-01

    Hyaluronic acid (HA), a natural biomaterial present in healthy joints but depleted in osteoarthritis (OA), has been employed clinically to provide symptomatic relief of joint pain. Joint movement combined with a reduced joint lubrication in osteoarthritic knees can result in increased wear and tear, chondrocyte apoptosis, and inflammation, leading to cascading cartilage deterioration. Therefore, development of an appropriate cartilage model and evaluation for its friction properties with potential lubricants in different conditions is necessary, which can closely resemble a mechanically induced OA cartilage. Additionally, the comparison of different models with and without endogenous lubricating surface zone proteins, such as PRG4 promotes a well-rounded understanding of cartilage lubrication. In this study, we present our findings on the lubricating effects of HA on different articular cartilage model surfaces in comparison to synovial fluid, a physiological lubricating biomaterial. The mechanical testings data demonstrated that HA reduced average static and kinetic friction coefficient values of the cartilage samples by 75% and 70%, respectively. Furthermore, HA mimicked the friction characteristics of freshly harvested natural synovial fluid throughout all tested and modeled OA conditions with no statistically significant difference. These characteristics led us to exclusively identify HA as an effective boundary layer lubricant in the technology that we develop to treat OA [Singh et al. 2104]. PMID:25858258

  1. Bone structure and quality preserved by active versus passive muscle exercise in 21 days tail-suspended rats

    NASA Astrophysics Data System (ADS)

    Luan, Huiqin; Sun, Lian-wen; Fan, Yu-bo

    2012-07-01

    Humans in Space suffer from microgravity-induced attenuated bone strength that needs to be addressed by on-orbit exercise countermeasures. However, exercise prescriptions so far did not adequately counteract the bone loss of astronauts in spaceflight because even active muscle contractions were converted to passive mode during voluntary bouts. We tested our hypothesis in unloaded rat hind limb following twenty-one days of tail-suspension (TS) combined with exercise using a hind limb stepper device designed by our group. Female Sprague Dawley rats (250g b.wt.) were divided into four groups (n=5, each): TS-only (hind limb unloading), TS plus passive mode exercise (TSP) induced by mechanically-forced passive hind limb lifting, TS plus active mode exercise (TSA) entrained by plantar electrostimulation, and control (CON) group. Standard measures of bone (e.g., mineral density, trabecular microstructure, biomechanics and ash weight) were monitored. Results provided that the attenuated properties of unloaded hind limb bone in TS-rats were more effectively supported by active mode than by passive mode motions. We here propose a modified exercise regimen combined with spontaneous muscle contractions thereby considering the biodynamic demands of both muscle and bone during resistive-load exercise in microgravity. Keywords: rat, BMD, DXA, passive exercise, active exercise, bone loss, tail suspension, spaceflight analogue, exercise countermeasure.

  2. Environment and genotype effects on antioxidant properties of organically grown wheat varieties: a 3-year study.

    PubMed

    Di Silvestro, Raffaella; Di Loreto, Alessandro; Bosi, Sara; Bregola, Valeria; Marotti, Ilaria; Benedettelli, Stefano; Segura-Carretero, Antonio; Dinelli, Giovanni

    2017-01-01

    Wheat grain (Triticum aestivum L.) possesses significant amounts of antioxidants that contribute to the dietary antiradical protection against a number of chronic diseases. Despite the increasing interest in organic food among both consumers and scientists, the availability of literature studies concerning the environment effect under organic management is still scarce. The aim of this study was to evaluate the antioxidant properties of wheat varieties by considering the genotype response to different environmental factors under biodynamic management. The soluble fraction of phenolic compounds was mainly determined by the environment, whereas a major genotypic effect was observed for the bound forms, which were present at higher amounts in red grain varieties. Moreover, a predominant effect of genotype was observed for yellow pigment content and antioxidant activity determined by the FRAP method. Despite some changes induced by environment, most genotypes had stable antioxidant properties and different phenolic profiles as determined by high-performance liquid chromatography-mass spectrometry, except for the old variety Inallettabile, which was the most sensitive to environmental fluctuations. The red grain varieties Andriolo, Gentil rosso and Verna were identified as the most promising breeding material for the development of varieties with high nutraceutical value under low-input management. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  3. Effects of foot placement, hand positioning, age and climbing biodynamics on ladder slip outcomes.

    PubMed

    Pliner, Erika M; Campbell-Kyureghyan, Naira H; Beschorner, Kurt E

    2014-01-01

    Ladder falls frequently cause severe injuries; yet the factors that influence ladder slips/falls are not well understood. This study aimed to quantify (1) the effects of restricted foot placement, hand positioning, climbing direction and age on slip outcomes, and (2) differences in climbing styles leading to slips versus styles leading to non-slips. Thirty-two occupational ladder users from three age groups (18-24, 25-44 and 45-64 years) were unexpectedly slipped climbing a vertical ladder, while being assigned to different foot placement conditions (unrestricted vs. restricted toe clearance) and different hand positions (rails vs. rungs). Constraining foot placement increased the climber's likelihood of slipping (p < 0.01), while younger and older participants slipped more than the middle-aged group (p < 0.01). Longer double stance time, dissimilar and more variable foot and body positioning were found in styles leading to a slip. Maintaining sufficient toe clearance and targeting ladder safety training to younger and older workers may reduce ladder falls. Practitioner Summary: Ladder falls frequently cause severe occupational fall injuries. This study aims to identify safer ladder climbing techniques and individuals at risk of falling. The results suggest that ladders with unrestricted toe clearance and ladder climbing training programmes, particularly for younger and older workers, may reduce ladder slipping risk.

  4. The Effect of Microplastic on the Uptake of Chemicals by the Lugworm Arenicola marina (L.) under Environmentally Relevant Exposure Conditions

    PubMed Central

    2017-01-01

    It has been hypothesized that ingestion of microplastic increases exposure of aquatic organisms to hydrophobic contaminants. To date, most laboratory studies investigated chemical transfer from ingested microplastic without taking other exposure pathways into account. Therefore, we studied the effect of polyethylene (PE) microplastic in sediment on PCB uptake by Arenicola marina as a model species, quantifying uptake fluxes from all natural exposure pathways. PCB concentrations in sediment, biota lipids (Clip) and porewater measured with passive samplers were used to derive lipid-normalized bioaccumulation metrics Clip, Biota sediment accumulation factor (BSAF), Bioaccumulation factor (BAF) and the Biota plastic accumulation factor (BPAF). Small effects of PE addition were detected suggesting slightly increased or decreased bioaccumulation. However, the differences decreased in magnitude dependent on the metric used to assess bioaccumulation, in the order: Clip > BSAF > BPAF > BAF, and were nonsignificant for BAF. The fact that BAF, that is, normalization of Clip on porewater concentration, largely removed all effects of PE, shows that PE did not act as a measurable vector of PCBs. Biodynamic model analysis confirmed that PE ingestion contributed marginally to bioaccumulation. This work confirmed model-based predictions on the limited relevance of microplastic for bioaccumulation under environmentally realistic conditions, and illustrated the importance of assessing exposure through all media in microplastic bioaccumulation studies. PMID:28682597

  5. Investigation of the transmission of fore and aft vibration through the human body.

    PubMed

    Demić, Miroslav; Lukić, Jovanka

    2009-07-01

    Understanding the behavior of human body under the influence of vibration is of great importance for the optimal motor vehicle system design. Therefore, great efforts are being done in order to discover as many information about the influence of vibration on human body as possible. So far the references show that the major scientific attention has been paid to vertical vibration, although intensive research has been performed lately on the other sorts of excitation. In this paper, the results of the investigation of behavior of human body, in seated position, under the influence of random fore and aft vibration are shown. The investigation is performed by the use of an electro-hydraulic simulator, on a group of 30 healthy male occupants. Experiments are performed in order to give results to improve human body modeling in driving conditions. Excitation amplitudes (1.75 and 2.25 m/s(2) rms) and seat backrest conditions (with and without inclination) were varied. Data results are analyzed by partial coherence and transfer functions. Analyses have been performed and results are given in detail. The results obtained have shown that the human body under the influence of random excitations behaves as a non-linear system and its response depends on spatial position. Obtained results give necessary data to define structure and parameters of human biodynamic model with respect to different excitation and seat backrest position.

  6. Delivering key signals to the machine: seeking the electric signal that muscles emanate

    NASA Astrophysics Data System (ADS)

    Bani Hashim, A. Y.; Maslan, M. N.; Izamshah, R.; Mohamad, I. S.

    2014-11-01

    Due to the limitation of electric power generation in the human body, present human-machine interfaces have not been successful because of the nature of standard electronics circuit designs, which do not consider the specifications of signals that resulted from the skin. In general, the outcomes and applications of human-machine interfaces are limited to custom-designed subsystems, such as neuroprosthesis. We seek to model the bio dynamical of sub skin into equivalent mathematical definitions, descriptions, and theorems. Within the human skin, there are networks of nerves that permit the skin to function as a multi dimension transducer. We investigate the nature of structural skin. Apart from multiple networks of nerves, there are other segments within the skin such as minute muscles. We identify the segments that are active when there is an electromyography activity. When the nervous system is firing signals, the muscle is being stimulated. We evaluate the phenomena of biodynamic of the muscles that is concerned with the electromyography activity of the nervous system. In effect, we design a relationship between the human somatosensory and synthetic systems sensory as the union of a complete set of the new domain of the functional system. This classifies electromyogram waveforms linked to intent thought of an operator. The system will become the basis for delivering key signals to machine such that the machine is under operator's intent, hence slavery.

  7. Perception and Biodynamics in Unalerted Precrash Response

    PubMed Central

    McGehee, Daniel V.; Carsten, Oliver M.J.

    2010-01-01

    This research seeks to better understand unalerted driver response just prior to a serious vehicle crash. Few studies have been able to view a crash from the inside—with a camera focused on the driver and occupants. Four studies are examined: 1) a high-fidelity simulator study with an unalerted intersection incursion crash among 107 drivers; 2) four crashes from the Virginia Tech Transportation Institute (VTTI) 100 car study; 3) 58 crashes from vehicles equipped with an event triggered video recorder; and 4) a custom-designed high-fidelity simulator experiment that examined unalerted driver response to a head-on crash with a heavy truck. Analyses concentrate on decomposing driver perception, action, facial and postural changes with a focus on describing the neurophysiologic mechanisms designed to respond to danger. Results indicate that drivers involved in severe crashes generally have preview that an impact is about to occur. They respond first with vehicle control inputs (accelerator pedal release) along with facial state changes and withdrawal of the head back towards the head restraint. These responses frequently occur almost simultaneously, providing safety system designers with a number of reliable driver performance measures to monitor. Understanding such mechanisms may assist future advanced driver assistance systems (ADAS), advanced restraints, model development of advanced anthropomorphic test dummies (ATDs), injury prediction and the integration of active and passive safety systems. PMID:21050614

  8. Biological uptake of polychlorinated biphenyls by Macoma balthica from sediment amended with activated carbon

    USGS Publications Warehouse

    McLeod, Pamela B.; van den Heuvel-Greve, Martine J.; Luoma, S.N.; Luthy, R.G.

    2007-01-01

    This work characterizes the efficacy of activated carbon amendment in reducing polychlorinated biphenyl (PCB) bioavailability to clams (Macoma balthica) from field-contaminated sediment (Hunters Point Naval Shipyard, San Francisco Bay, CA, USA) Test methods were developed for the use of clams to investigate the effects of sediment amendment on biological uptake. Sediment was mixed with activated carbon for one month. Bioaccumulation tests (28 d) were employed to assess the relationships between carbon dose and carbon particle size on observed reductions in clam biological uptake of PCBs. Extraction and cleanup protocols were developed for the clam tissue. Efficacy of activated carbon treatment was found to increase with both increasing carbon dose and decreasing carbon particle size. Average reductions in bioaccumulation of 22, 64, and 84% relative to untreated Hunters Point sediment were observed for carbon amendments of 0.34, 1.7, and 3.4%, respectively. Average bioaccumulation reductions of 41, 73, and 89% were observed for amendments (dose = 1.7% dry wt) with carbon particles of 180 to 250, 75 to 180, and 25 to 75 ??m, respectively, in diameter, indicating kinetic phenomena in these tests. Additionally, a biodynamic model quantifying clam PCB uptake from water and sediment as well as loss through elimination provided a good fit of experimental data. Model predictions suggest that the sediment ingestion route contributed 80 to 95% of the PCB burdens in the clams. ?? 2007 SETAC.

  9. The influence of urea and nitrate nutrients on the bioavailability and toxicity of nickel to Prorocentrum donghaiense (Dinophyta) and Skeletonema costatum (Bacillariophyta).

    PubMed

    Huang, Xu-Guang; Lin, Xie-Chang; Li, Shun-Xing; Xu, Song-Li; Liu, Feng-Jiao

    2016-12-01

    Nitrogen nutrients and nickel(Ni) are ubiquitous in aquatic environments, and they are important for primary production of ocean ecosystem. This study examined the interaction of nitrogen nutrients (specifically urea and nitrate) and Ni on chlorophyll (Chl a) concentration and photosynthesis parameters values of Prorocentrum donghaiense and Skeletonema costatum. The data presented here indicate that low concentration of Ni for P. donghaiense and S. costatum can enhance both Chl a concentration and photosynthesis parameters values when grown in urea containing environment. Despite this increase there was also an observed depression in both species tested when incubated in high concentration of Ni for P. donghaiense and S. costatum regardless of incubating in urea or nitrate. Additionally, EC 50 values of Chl a and Fv/Fm for Ni at different time intervals were calculated in this study. These observations indicated that the Ni tolerance was higher in P. donghaiense as compared to S. costatum. The Ni tolerance of P. donghaiense incubated in urea was higher than that incubating in nitrate. The same phenomenon was not observed in S. costatum, which indicated that the influence of urea was dependent on the species investigated. Thus, urea input could impact Ni bioavailability and toxicity, and then affect the biodynamics thereafter. Copyright © 2016. Published by Elsevier B.V.

  10. Observations from a 4-year contamination study of a sample depth profile through Martian meteorite Nakhla.

    PubMed

    Toporski, Jan; Steele, Andrew

    2007-04-01

    Morphological, compositional, and biological evidence indicates the presence of numerous well-developed microbial hyphae structures distributed within four different sample splits of the Nakhla meteorite obtained from the British Museum (allocation BM1913,25). By examining depth profiles of the sample splits over time, morphological changes displayed by the structures were documented, as well as changes in their distribution on the samples, observations that indicate growth, decay, and reproduction of individual microorganisms. Biological staining with DNA-specific molecular dyes followed by epifluorescence microscopy showed that the hyphae structures contain DNA. Our observations demonstrate the potential of microbial interaction with extraterrestrial materials, emphasize the need for rapid investigation of Mars return samples as well as any other returned or impactor-delivered extraterrestrial materials, and suggest the identification of appropriate storage conditions that should be followed immediately after samples retrieved from the field are received by a handling/curation facility. The observations are further relevant in planetary protection considerations as they demonstrate that microorganisms may endure and reproduce in extraterrestrial materials over long (at least 4 years) time spans. The combination of microscopy images coupled with compositional and molecular staining techniques is proposed as a valid method for detection of life forms in martian materials as a first-order assessment. Time-resolved in situ observations further allow observation of possible (bio)dynamics within the system.

  11. The Effect of Microplastic on the Uptake of Chemicals by the Lugworm Arenicola marina (L.) under Environmentally Relevant Exposure Conditions.

    PubMed

    Besseling, Ellen; Foekema, Edwin M; van den Heuvel-Greve, Martine J; Koelmans, Albert A

    2017-08-01

    It has been hypothesized that ingestion of microplastic increases exposure of aquatic organisms to hydrophobic contaminants. To date, most laboratory studies investigated chemical transfer from ingested microplastic without taking other exposure pathways into account. Therefore, we studied the effect of polyethylene (PE) microplastic in sediment on PCB uptake by Arenicola marina as a model species, quantifying uptake fluxes from all natural exposure pathways. PCB concentrations in sediment, biota lipids (C lip ) and porewater measured with passive samplers were used to derive lipid-normalized bioaccumulation metrics C lip , Biota sediment accumulation factor (BSAF), Bioaccumulation factor (BAF) and the Biota plastic accumulation factor (BPAF). Small effects of PE addition were detected suggesting slightly increased or decreased bioaccumulation. However, the differences decreased in magnitude dependent on the metric used to assess bioaccumulation, in the order: C lip > BSAF > BPAF > BAF, and were nonsignificant for BAF. The fact that BAF, that is, normalization of C lip on porewater concentration, largely removed all effects of PE, shows that PE did not act as a measurable vector of PCBs. Biodynamic model analysis confirmed that PE ingestion contributed marginally to bioaccumulation. This work confirmed model-based predictions on the limited relevance of microplastic for bioaccumulation under environmentally realistic conditions, and illustrated the importance of assessing exposure through all media in microplastic bioaccumulation studies.

  12. Comparison of Biodynamic Responses in Standing and Seated Human Bodies

    NASA Astrophysics Data System (ADS)

    MATSUMOTO, Y.; GRIFFIN, M. J.

    2000-12-01

    The dynamic responses of the human body in a standing position and in a sitting position have been compared. The apparent mass and transmissibilities to the head, six locations along the spine, and the pelvis were measured with eight male subjects exposed to vertical whole-body vibration. In both postures, the principal resonance in the apparent mass occurred in the range 5-6 Hz, with slightly higher frequencies and lower apparent mass in the standing posture. There was greater transmission of vertical vibration to the pelvis and the lower spine and greater relative motion within the lower spine in the standing posture than in the sitting posture at the principal resonance and at higher frequencies. Transmissibilities from the supporting surface (floor or seat) to the thoracic region had similar magnitudes for both standing and sitting subjects. The lumbar spine has less lordosis and may be more compressed and less flexible in the sitting posture than in the standing posture. This may have reduced the relative motions between lumbar vertebrae and both the supporting vibrating surface and the other vertebrae in the sitting posture. The characteristics of the vibration transmitted to the pelvis may have differed in the two postures due to different transmission paths. Increased forward rotation of the pelvis in the standing posture may have caused the differences in responses of the pelvis and the lower spine that were observed between the two postures.

  13. Cadmium biodynamics in the oligochaete Lumbriculus variegatus and its implications for trophic transfer

    USGS Publications Warehouse

    Xie, Lingtian; Lambert, D.; Martin, C.; Cain, D.J.; Luoma, S.N.; Buchwalter, D.

    2008-01-01

    It has become increasingly apparent that diet can be a major source of trace metal bioaccumulation in aquatic organisms. In this study, we examined cadmium uptake, efflux, and subcellular compartmentalization dynamics in the freshwater oligochaete Lumbriculus variegatus. L. variegatus is an important component of freshwater food webs in Europe and North America and is potentially useful as a standard food source for laboratory-based trophic transfer studies. Cadmium accumulation and depuration were each followed for 10 days. Rate constants of uptake (ku) and efflux (ke) were estimated and subcellular Cd compartmentalization was followed over the course of uptake and efflux. The partitioning of Cd into operationally-defined subcellular compartments was relatively consistent throughout the 20-day experiment, with the majority of Cd accumulating in the cytosol. No major changes in Cd compartmentalization were observed over uptake or depuration, but there appeared to be some exchange between heat-stable and heat-labile cytosolic protein fractions. Cadmium accumulation from solution was strongly affected by ambient calcium concentrations, suggesting competition between Cd and Ca for uptake sites. Finally, we demonstrate the ability to manipulate the whole body calcium content of L. variegatus as a potential tool for examining calcium influences on dietary Cd dynamics. The potential for this species to be an important conduit of Cd to higher trophic levels is discussed, along with its potential as a standardized food source in metal trophic transfer studies. ?? 2007 Elsevier B.V. All rights reserved.

  14. Omega "Ω" Pulley Plasty for Surgical Management of DeQuervain's Disease.

    PubMed

    Bakhach, Joseph; Chaya, Bachar; Papazian, Nazareth

    2018-06-01

    DeQuervain tenosynovitis, refractory to medical conservative treatment, has been traditionally treated by a simple division of the pulley, a procedure associated with several complications. Many authors attempted to prevent these complications by describing techniques of pulley reconstruction after its release necessitating suturing the different flaps and subsequently promoting extensor tendons adhesions. The authors present an alternative procedure for the first extensor compartment pulley decompression: "Omegaplasty". 25 Patients with 29 DeQuervain tenosynovitis cases were enrolled in a prospective, nonrandomized clinical trial from 2012 to 2016. At enrollment they were offered the option of Omegaplasty as a surgical treatment modality for their cases. The procedure is based on liberating the anterior attachment of the pulley from the anterior lip of the styloïd process while respecting its continuity with the periosteal flap as well as promoting expansion of the tunnel volume. All operated patients were evaluated using the "Opposition Kapandji Score". The authors present the results of 29 different "Omegaplasty" procedures. Based on the Kapandji opposition score, twenty cases scored 10/10 while the remaining nine cases yielded an 8/10 score each. The described technique is simple, reliable and respects the extensor tendons gliding physiology and biodynamics. By preserving the anatomical continuity of the first extensor compartment pulley at the wrist, the risk of adhesion formation is reduced. The preliminary results are encouraging and provide the "Ω" plasty the potential to be considered as a surgical option for treatment of De Quervain Tenosynovitis.

  15. Assessment of field-related influences on polychlorinated biphenyl exposures and sorbent amendment using polychaete bioassays and passive sampler measurements

    USGS Publications Warehouse

    Janssen, E.M.; Oen, A.M.; Luoma, S.N.; Luthy, R.G.

    2011-01-01

    Field-related influences on polychlorinated biphenyl (PCB) exposure were evaluated by employing caged deposit-feeders, Neanthes arenaceodentata, along with polyoxymethylene (POM) samplers using parallel in situ and ex situ bioassays with homogenized untreated or activated carbon (AC) amended sediment. The AC amendment achieved a remedial efficiency in reducing bioaccumulation by 90% in the laboratory and by 44% in the field transplants. In situ measurements showed that PCB uptake by POM samplers was greater for POM placed in the surface sediment compared with the underlying AC amendment, suggesting that tidal exchange of surrounding material with similar PCB availability as untreated sediment was redeposited in the cages. Polychlorinated biphenyls bioaccumulation with caged polychaetes from untreated sediment was half as large under field conditions compared with laboratory conditions. A biodynamic model was used to confirm and quantify the different processes that could have influenced these results. Three factors appeared most influential in the bioassays: AC amendment significantly reduces bioavailability under laboratory and field conditions; sediment deposition within test cages in the field partially masks the remedial benefit of underlying AC-amended sediment; and deposit-feeders exhibit less PCB uptake from untreated sediment when feeding is reduced. Ex situ and in situ experiments inevitably show some differences that are associated with measurement methods and effects of the environment. Parallel ex situ and in situ bioassays, passive sampler measurements, and quantifying important processes with a model can tease apart these field influences. ?? 2010 SETAC.

  16. [Towards a structuring fibrillar ontology].

    PubMed

    Guimberteau, J-C

    2012-10-01

    Over previous decades and centuries, the difficulty encountered in the manner in which the tissue of our bodies is organised, and structured, is clearly explained by the impossibility of exploring it in detail. Since the creation of the microscope, the perception of the basic unity, which is the cell, has been essential in understanding the functioning of reproduction and of transmission, but has not been able to explain the notion of form; since the cells are not everywhere and are not distributed in an apparently balanced manner. The problems that remain are those of form and volume and also of connection. The concept of multifibrillar architecture, shaping the interfibrillar microvolumes in space, represents a solution to all these questions. The architectural structures revealed, made up of fibres, fibrils and microfibrils, from the mesoscopic to the microscopic level, provide the concept of a living form with structural rationalism that permits the association of psychochemical molecular biodynamics and quantum physics: the form can thus be described and interpreted, and a true structural ontology is elaborated from a basic functional unity, which is the microvacuole, the intra and interfibrillar volume of the fractal organisation, and the chaotic distribution. Naturally, new, less linear, less conclusive, and less specific concepts will be implied by this ontology, leading one to believe that the emergence of life takes place under submission to forces that the original form will have imposed and oriented the adaptive finality. Copyright © 2012. Published by Elsevier SAS.

  17. Segmental Dynamics of Forward Fall Arrests: System Identification Approach

    PubMed Central

    Kim, Kyu-Jung; Ashton-Miller, James A.

    2009-01-01

    Background Fall-related injuries are multifaceted problems, necessitating thorough biodynamic simulation to identify critical biomechanical factors. Methods A 2-degree-of-freedom discrete impact model was constructed through system identification and validation processes using the experimental data to understand dynamic interactions of various biomechanical parameters in bimanual forward fall arrests. Findings The bimodal reaction force response from the identified models had small identification errors for the first and second force peaks less than 3.5% and high coherence between the measured and identified model responses (R2=0.95). Model validation with separate experimental data also demonstrated excellent validation accuracy and coherence, less than 7% errors and R2=0.87, respectively. The first force peak was usually greater than the second force peak and strongly correlated with the impact velocity of the upper extremity, while the second force peak was associated with the impact velocity of the body. The impact velocity of the upper extremity relative to the body could be a major risk factor to fall-related injuries as observed from model simulations that a 75% faster arm movement relative to the falling speed of the body alone could double the first force peak from soft landing, thereby readily exceeding the fracture strength of the distal radius. Interpretation Considering that the time-critical nature of falling often calls for a fast arm movement, the use of the upper extremity in forward fall arrests is not biomechanically justified unless sufficient reaction time and coordinated protective motion of the upper extremity are available. PMID:19250726

  18. The geometry of high angle of attack maneuvers and the implications for Gy-induced neck injuries.

    PubMed

    Newman, David G; Ostler, David

    2011-08-01

    Modern super agile fighter aircraft have significantly expanded maneuverability envelopes, often involving very high angles of attack (AOA) in the post-stall region. One such maneuver is the high AOA velocity vector roll. The geometry of this flight maneuver is such that during the roll there is a significant lateral C load imposed on the unrestrained head-neck complex of the pilot. A mathematical analysis of the geometric relationship determining the magnitude of +/- Gy acceleration during high AOA maneuvering was conducted. This preliminary mathematical model is able to predict the Gy load imposed on the head-neck complex of the pilot for a given set of flight maneuver parameters. The analysis predicts that at an AOA of 700 and with a roll rate of 100 degrees x s(-1), the lateral G developed will be approximately 3.5 Gy. Increasing the roll rate increases the lateral G component: at 200 degrees x s(-1) the Gy, load is more than 6 Gy. There are serious potential implications of super agile maneuvers on the neck of the pilot. The G environment experienced by the pilot of super agile aircraft is increasingly multiaxial, involving +/- Gx, +/- Gy, and +/- Gz. The level of lateral G developed during these dynamic flight maneuvers should not be underestimated, as such G loads can potentially lead to neck injuries. While aircraft become ever more capable, a full understanding of the biodynamic effects on the pilot while exploiting the agility of the aircraft still needs to be developed.

  19. Contact area affects frequency-dependent responses to vibration in the peripheral vascular and sensorineural systems.

    PubMed

    Krajnak, Kristine; Miller, G R; Waugh, Stacey

    2018-01-01

    Repetitive exposure to hand-transmitted vibration is associated with development of peripheral vascular and sensorineural dysfunctions. These disorders and symptoms associated with it are referred to as hand-arm vibration syndrome (HAVS). Although the symptoms of the disorder have been well characterized, the etiology and contribution of various exposure factors to development of the dysfunctions are not well understood. Previous studies performed using a rat-tail model of vibration demonstrated that vascular and peripheral nervous system adverse effects of vibration are frequency-dependent, with vibration frequencies at or near the resonant frequency producing the most severe injury. However, in these investigations, the amplitude of the exposed tissue was greater than amplitude typically noted in human fingers. To determine how contact with vibrating source and amplitude of the biodynamic response of the tissue affects the risk of injury occurring, this study compared the influence of frequency using different levels of restraint to assess how maintaining contact of the tail with vibrating source affects the transmission of vibration. Data demonstrated that for the most part, increasing the contact of the tail with the platform by restraining it with additional straps resulted in an enhancement in transmission of vibration signal and elevation in factors associated with vascular and peripheral nerve injury. In addition, there were also frequency-dependent effects, with exposure at 250 Hz generating greater effects than vibration at 62.5 Hz. These observations are consistent with studies in humans demonstrating that greater contact and exposure to frequencies near the resonant frequency pose the highest risk for generating peripheral vascular and sensorineural dysfunction.

  20. Vibration energy absorption in the whole-body system of a tractor operator.

    PubMed

    Szczepaniak, Jan; Tanaś, Wojciech; Kromulski, Jacek

    2014-01-01

    Many people are exposed to whole-body vibration (WBV) in their occupational lives, especially drivers of vehicles such as tractor and trucks. The main categories of effects from WBV are perception degraded comfort interference with activities-impaired health and occurrence of motion sickness. Absorbed power is defined as the power dissipated in a mechanical system as a result of an applied force. The vibration-induced injuries or disorders in a substructure of the human system are primarily associated with the vibration power absorption distributed in that substructure. The vibration power absorbed by the exposed body is a measure that combines both the vibration hazard and the biodynamic response of the body. The article presents measurement method for determining vibration power dissipated in the human whole body system called Vibration Energy Absorption (VEA). The vibration power is calculated from the real part of the force-velocity cross-spectrum. The absorbed power in the frequency domain can be obtained from the cross-spectrum of the force and velocity. In the context of the vibration energy transferred to a seated human body, the real component reflects the energy dissipated in the biological structure per unit of time, whereas the imaginary component reflects the energy stored/released by the system. The seated human is modeled as a series/parallel 4-DOF dynamic models. After introduction of the excitation, the response in particular segments of the model can be analyzed. As an example, the vibration power dissipated in an operator has been determined as a function of the agricultural combination operating speed 1.39 - 4.16 ms(-1).

  1. Wild Grape-Associated Yeasts as Promising Biocontrol Agents against Vitis vinifera Fungal Pathogens.

    PubMed

    Cordero-Bueso, Gustavo; Mangieri, Nicola; Maghradze, David; Foschino, Roberto; Valdetara, Federica; Cantoral, Jesús M; Vigentini, Ileana

    2017-01-01

    The increasing level of hazardous residues in the environment and food chains has led the European Union to restrict the use of chemical fungicides. Thus, exploiting new natural antagonistic microorganisms against fungal diseases could serve the agricultural production to reduce pre- and post-harvest losses, to boost safer practices for workers and to protect the consumers' health. The main aim of this work was to evaluate the antagonistic potential of epiphytic yeasts against Botrytis cinerea, Aspergillus carbonarius , and Penicillium expansum pathogen species. In particular, yeast isolation was carried out from grape berries of Vitis vinifera ssp sylvestris populations, of the Eurasian area, and V. vinifera ssp vinifera cultivars from three different farming systems (organic, biodynamic, and conventional). Strains able to inhibit or slow the growth of pathogens were selected by in vitro and in vivo experiments. The most effective antagonist yeast strains were subsequently assayed for their capability to colonize the grape berries. Finally, possible modes of action, such as nutrients and space competition, iron depletion, cell wall degrading enzymes, diffusible and volatile antimicrobial compounds, and biofilm formation, were investigated as well. Two hundred and thirty-one yeast strains belonging to 26 different species were isolated; 20 of them, ascribed to eight species, showed antagonistic action against all molds. Yeasts isolated from V. vinifera ssp sylvestris were more effective (up to 50%) against B. cinerea rather than those isolated from V. vinifera ssp vinifera. Six strains, all isolated from wild vines, belonging to four species ( Meyerozyma guilliermondii, Hanseniaspora uvarum, Hanseniaspora clermontiae , and Pichia kluyveri ) revealed one or more phenotypical characteristics associated to the analyzed modes of antagonistic action.

  2. Dynamic forces over the interface between a seated human body and a rigid seat during vertical whole-body vibration.

    PubMed

    Liu, Chi; Qiu, Yi; Griffin, Michael J

    2017-08-16

    Biodynamic responses of the seated human body are usually measured and modelled assuming a single point of vibration excitation. With vertical vibration excitation, this study investigated how forces are distributed over the body-seat interface. Vertical and fore-and-aft forces were measured beneath the ischial tuberosities, middle thighs, and front thighs of 14 subjects sitting on a rigid flat seat in three postures with different thigh contact while exposed to random vertical vibration at three magnitudes. Measures of apparent mass were calculated from transfer functions between the vertical acceleration of the seat and the vertical or fore-and-aft forces measured at the three locations, and the sum of these forces. When sitting normally or sitting with a high footrest, vertical forces at the ischial tuberosities dominated the vertical apparent mass. With feet unsupported to give increased thigh contact, vertical forces at the front thighs were dominant around 8Hz. Around 3-7Hz, fore-and-aft forces at the middle thighs dominated the fore-and-aft cross-axis apparent mass. Around 8-10Hz, fore-and-aft forces were dominant at the ischial tuberosities with feet supported but at the front thighs with feet unsupported. All apparent masses were nonlinear: as the vibration magnitude increased the resonance frequencies decreased. With feet unsupported, the nonlinearity in the apparent mass was greater at the front thighs than at the ischial tuberosities. It is concluded that when the thighs are supported on a seat it is not appropriate to assume the body has a single point of vibration excitation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. American palm ethnomedicine: A meta-analysis

    PubMed Central

    2009-01-01

    Background Many recent papers have documented the phytochemical and pharmacological bases for the use of palms (Arecaceae) in ethnomedicine. Early publications were based almost entirely on interviews that solicited local knowledge. More recently, ethnobotanically guided searches for new medicinal plants have proven more successful than random sampling for identifying plants that contain biodynamic ingredients. However, limited laboratory time and the high cost of clinical trials make it difficult to test all potential medicinal plants in the search for new drug candidates. The purpose of this study was to summarize and analyze previous studies on the medicinal uses of American palms in order to narrow down the search for new palm-derived medicines. Methods Relevant literature was surveyed and data was extracted and organized into medicinal use categories. We focused on more recent literature than that considered in a review published 25 years ago. We included phytochemical and pharmacological research that explored the importance of American palms in ethnomedicine. Results Of 730 species of American palms, we found evidence that 106 species had known medicinal uses, ranging from treatments for diabetes and leishmaniasis to prostatic hyperplasia. Thus, the number of American palm species with known uses had increased from 48 to 106 over the last quarter of a century. Furthermore, the pharmacological bases for many of the effects are now understood. Conclusions Palms are important in American ethnomedicine. Some, like Serenoa repens and Roystonea regia, are the sources of drugs that have been approved for medicinal uses. In contrast, recent ethnopharmacological studies suggested that many of the reported uses of several other palms do not appear to have a strong physiological basis. This study has provided a useful assessment of the ethnobotanical and pharmacological data available on palms. PMID:20034398

  4. Effect of cysteine and humic acids on bioavailability of Ag from Ag nanoparticles to a freshwater snail

    USGS Publications Warehouse

    Luoma, Samuel N.; Tasha Stoiber,; Croteau, Marie-Noele; Isabelle Romer,; Ruth Merrifeild,; Lead, Jamie

    2016-01-01

    Metal-based engineered nanoparticles (NPs) will undergo transformations that will affect their bioavailability, toxicity and ecological risk when released to the environment, including interactions with dissolved organic material. The purpose of this paper is to determine how interactions with two different types of organic material affect the bioavailability of silver nanoparticles (AgNPs). Silver uptake rates by the pond snail Lymnaea stagnalis were determined after exposure to 25 nmol l-1 of Ag as PVP AgNPs, PEG AgNPs or AgNO3, in the presence of either Suwannee River humic acid or cysteine, a high-affinity thiol-rich organic ligand. Total uptake rate of Ag from the two NPs was either increased or not strongly affected in the presence of 1 – 10 mg 1-1 humic acid. Humic substances contain relatively few strong ligands for Ag explaining their limited effects on Ag uptake rate. In contrast, Ag uptake rate was substantially reduced by cysteine. Three components of uptake from the AgNPs were quantified in the presence of cysteine using a biodynamic modeling approach: uptake of dissolved Ag released by the AgNPs, uptake of a polymer or large (>3kD) Ag-cysteine complex and uptake of the nanoparticle itself. Addition of 1:1 Ag:cysteine reduced concentrations of dissolved Ag, which contributed to, but did not fully explain the reductions in uptake. A bioavailable Ag-cysteine complex (> 3kD) appeared to be the dominant avenue of uptake from both PVP AgNPs and PEG AgNPs in the presence of cysteine. Quantifying the different avenues of uptake sets the stage for studies to assess toxicity unique to NPs.

  5. Mechanical instability after an acute lateral ankle sprain.

    PubMed

    Hubbard, Tricia J; Cordova, Mitchell

    2009-07-01

    To examine the natural recovery of mechanical laxity after an ankle sprain over an 8-week period. Prospective cohort study. Biodynamics research laboratory. Subjects with an acute lateral ankle sprain (n=16; 7 men, 9 women; age, 19.5+/-0.7y; mass, 64.6+/-8.1 kg; height, 171.9+/-9.6 cm) and healthy controls (n=16; 7 men, 9 women; age, 20.4+/-1.7y; mass, 76.9+/-11.1 kg; height, 176.5+/-11.1 cm) participated. Not applicable. Subjects with acute ankle sprains were tested 3 days after injury and again 8 weeks later. Anterior and posterior displacement (mm) and inversion and eversion rotation ( degrees ) were measured with an instrumented arthrometer. For each dependent variable, a 2 x 2 x 2 repeated-measures multivariate analysis of variance was performed. A significant interaction was found between group, time, and side for anterior translation (F=4.24, P=.05). There were also significant main effects for group. There was significantly more anterior displacement at day 3 (F=19.52, P=.001) and at week 8 (F=8.45, P=.010) in the injured group compared with the healthy group. There was also significantly more inversion rotation at day 3 (F=2.70, P=.002) and at week 8 (F=5.4, P=.033) in the injured group compared with the healthy group. The lack of significant differences in mechanical laxity over an 8-week period suggests that natural recovery of laxity takes longer than 8 weeks. Further research needs to be conducted to examine how long this laxity persists and the role ankle rehabilitation plays in mechanical stability restoration.

  6. Measurement and modelling of x-direction apparent mass of the seated human body-cushioned seat system.

    PubMed

    Stein, George Juraj; Múcka, Peter; Chmúrny, Rudolf; Hinz, Barbara; Blüthner, Ralph

    2007-01-01

    For modelling purposes and for evaluation of driver's seat performance in the vertical direction various mechano-mathematical models of the seated human body have been developed and standardized by the ISO. No such models exist hitherto for human body sitting in an upright position in a cushioned seat upper part, used in industrial environment, where the fore-and-aft vibrations play an important role. The interaction with the steering wheel has to be taken into consideration, as well as, the position of the human body upper torso with respect to the cushioned seat back as observed in real driving conditions. This complex problem has to be simplified first to arrive at manageable simpler models, which still reflect the main problem features. In a laboratory study accelerations and forces in x-direction were measured at the seat base during whole-body vibration in the fore-and-aft direction (random signal in the frequency range between 0.3 and 30 Hz, vibration magnitudes 0.28, 0.96, and 2.03 ms(-2) unweighted rms). Thirteen male subjects with body masses between 62.2 and 103.6 kg were chosen for the tests. They sat on a cushioned driver seat with hands on a support and backrest contact in the lumbar region only. Based on these laboratory measurements a linear model of the system-seated human body and cushioned seat in the fore-and-aft direction has been developed. The model accounts for the reaction from the steering wheel. Model parameters have been identified for each subject-measured apparent mass values (modulus and phase). The developed model structure and the averaged parameters can be used for further bio-dynamical research in this field.

  7. Vibrations transmitted from human hands to upper arm, shoulder, back, neck, and head.

    PubMed

    Xu, Xueyan S; Dong, Ren G; Welcome, Daniel E; Warren, Christopher; McDowell, Thomas W; Wu, John Z

    2017-12-01

    Some powered hand tools can generate significant vibration at frequencies below 25 Hz. It is not clear whether such vibration can be effectively transmitted to the upper arm, shoulder, neck, and head and cause adverse effects in these substructures. The objective of this study is to investigate the vibration transmission from the human hands to these substructures. Eight human subjects participated in the experiment, which was conducted on a 1-D vibration test system. Unlike many vibration transmission studies, both the right and left hand-arm systems were simultaneously exposed to the vibration to simulate a working posture in the experiment. A laser vibrometer and three accelerometers were used to measure the vibration transmitted to the substructures. The apparent mass at the palm of each hand was also measured to help in understanding the transmitted vibration and biodynamic response. This study found that the upper arm resonance frequency was 7-12 Hz, the shoulder resonance was 7-9 Hz, and the back and neck resonances were 6-7 Hz. The responses were affected by the hand-arm posture, applied hand force, and vibration magnitude. The transmissibility measured on the upper arm had a trend similar to that of the apparent mass measured at the palm in their major resonant frequency ranges. The implications of the results are discussed. Musculoskeletal disorders (MSDs) of the shoulder and neck are important issues among many workers. Many of these workers use heavy-duty powered hand tools. The combined mechanical loads and vibration exposures are among the major factors contributing to the development of MSDs. The vibration characteristics of the body segments examined in this study can be used to help understand MSDs and to help develop more effective intervention methods.

  8. Vibrations transmitted from human hands to upper arm, shoulder, back, neck, and head

    PubMed Central

    Xu, Xueyan S.; Dong, Ren G.; Welcome, Daniel E.; Warren, Christopher; McDowell, Thomas W.; Wu, John Z.

    2016-01-01

    Some powered hand tools can generate significant vibration at frequencies below 25 Hz. It is not clear whether such vibration can be effectively transmitted to the upper arm, shoulder, neck, and head and cause adverse effects in these substructures. The objective of this study is to investigate the vibration transmission from the human hands to these substructures. Eight human subjects participated in the experiment, which was conducted on a 1-D vibration test system. Unlike many vibration transmission studies, both the right and left hand-arm systems were simultaneously exposed to the vibration to simulate a working posture in the experiment. A laser vibrometer and three accelerometers were used to measure the vibration transmitted to the substructures. The apparent mass at the palm of each hand was also measured to help in understanding the transmitted vibration and biodynamic response. This study found that the upper arm resonance frequency was 7–12 Hz, the shoulder resonance was 7–9 Hz, and the back and neck resonances were 6–7 Hz. The responses were affected by the hand-arm posture, applied hand force, and vibration magnitude. The transmissibility measured on the upper arm had a trend similar to that of the apparent mass measured at the palm in their major resonant frequency ranges. The implications of the results are discussed. Relevance to industry Musculoskeletal disorders (MSDs) of the shoulder and neck are important issues among many workers. Many of these workers use heavy-duty powered hand tools. The combined mechanical loads and vibration exposures are among the major factors contributing to the development of MSDs. The vibration characteristics of the body segments examined in this study can be used to help understand MSDs and to help develop more effective intervention methods. PMID:29123326

  9. Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete: Part I: relative importance of water and sediment as exposure routes

    USGS Publications Warehouse

    Ramskov, Tina; Thit, Amalie; Croteau, Marie-Noele; Selck, Henriette

    2015-01-01

    Copper oxide (CuO) nanoparticles (NPs) are widely used, and likely released into the aquatic environment. Both aqueous (i.e., dissolved Cu) and particulate Cu can be taken up by organisms. However, how exposure routes influence the bioavailability and subsequent toxicity of Cu remains largely unknown. Here, we assess the importance of exposure routes (water and sediment) and Cu forms (aqueous and nanoparticulate) on Cu bioavailability and toxicity to the freshwater oligochaete, Lumbriculus variegatus, a head-down deposit-feeder. We characterize the bioaccumulation dynamics of Cu in L. variegatus across a range of exposure concentrations, covering both realistic and worst-case levels of Cu contamination in the environment. Both aqueous Cu (Cu-Aq; administered as Cu(NO3)2) and nanoparticulate Cu (CuO NPs), whether dispersed in artificial moderately hard freshwater or mixed into sediment, were weakly accumulated by L. variegatus. Once incorporated into tissues, Cu elimination was negligible, i.e., elimination rate constants were in general not different from zero for either exposure route or either Cu form. Toxicity was only observed after waterborne exposure to Cu-Aq at very high concentration (305 µgL-1), where all worms died. There was no relationship between exposure route, Cu form or Cu exposure concentration on either worm survival or growth. Slow feeding rates and low Cu assimilation efficiency (approximately 30%) characterized the uptake of Cu from the sediment for both Cu forms. In nature, L. variegatus is potentially exposed to Cu via both water and sediment. However, sediment progressively becomes the predominant exposure route for Cu in L. variegatus as Cu partitioning to sediment increases.

  10. Wild Grape-Associated Yeasts as Promising Biocontrol Agents against Vitis vinifera Fungal Pathogens

    PubMed Central

    Cordero-Bueso, Gustavo; Mangieri, Nicola; Maghradze, David; Foschino, Roberto; Valdetara, Federica; Cantoral, Jesús M.; Vigentini, Ileana

    2017-01-01

    The increasing level of hazardous residues in the environment and food chains has led the European Union to restrict the use of chemical fungicides. Thus, exploiting new natural antagonistic microorganisms against fungal diseases could serve the agricultural production to reduce pre- and post-harvest losses, to boost safer practices for workers and to protect the consumers' health. The main aim of this work was to evaluate the antagonistic potential of epiphytic yeasts against Botrytis cinerea, Aspergillus carbonarius, and Penicillium expansum pathogen species. In particular, yeast isolation was carried out from grape berries of Vitis vinifera ssp sylvestris populations, of the Eurasian area, and V. vinifera ssp vinifera cultivars from three different farming systems (organic, biodynamic, and conventional). Strains able to inhibit or slow the growth of pathogens were selected by in vitro and in vivo experiments. The most effective antagonist yeast strains were subsequently assayed for their capability to colonize the grape berries. Finally, possible modes of action, such as nutrients and space competition, iron depletion, cell wall degrading enzymes, diffusible and volatile antimicrobial compounds, and biofilm formation, were investigated as well. Two hundred and thirty-one yeast strains belonging to 26 different species were isolated; 20 of them, ascribed to eight species, showed antagonistic action against all molds. Yeasts isolated from V. vinifera ssp sylvestris were more effective (up to 50%) against B. cinerea rather than those isolated from V. vinifera ssp vinifera. Six strains, all isolated from wild vines, belonging to four species (Meyerozyma guilliermondii, Hanseniaspora uvarum, Hanseniaspora clermontiae, and Pichia kluyveri) revealed one or more phenotypical characteristics associated to the analyzed modes of antagonistic action. PMID:29163377

  11. Corneal Deformation Response and Ocular Geometry: A Noninvasive Diagnostic Strategy in Marfan Syndrome.

    PubMed

    Beene, Lauren C; Traboulsi, Elias I; Seven, Ibrahim; Ford, Matthew R; Sinha Roy, Abhijit; Butler, Robert S; Dupps, William J

    2016-01-01

    To evaluate corneal air-puff deformation responses and ocular geometry as predictors of Marfan syndrome. Prospective observational clinical study. Sixteen investigator-derived, 4 standard Ocular Response Analyzer (ORA), and geometric variables from corneal tomography and optical biometry using Oculus Pentacam and IOL Master were assessed for discriminative value in Marfan syndrome, measuring right eyes of 24 control and 13 Marfan syndrome subjects. Area under the receiver operating characteristic (AUROC) curve was assessed in univariate and multivariate analyses. Six investigator-derived ORA variables successfully discriminated Marfan syndrome. The best lone disease predictor was Concavity Min (Marfan syndrome 47.5 ± 20, control 69 ± 14, P = .003; AUROC = 0.80). Corneal hysteresis (CH) and corneal resistance factor (CRF) were decreased (Marfan syndrome CH 9.45 ± 1.62, control CH 11.24 ± 1.21, P = .01; Marfan syndrome CRF 9.77 ± 1.65, control CRF 11.03 ± 1.72, P = .01) and corneas were flatter in Marfan syndrome (Marfan syndrome Kmean 41.25 ± 2.09 diopter, control Kmean 42.70 ± 1.81 diopter, P = .046). No significant differences were observed in central corneal thickness, axial eye length, or intraocular pressure. A multivariate regression model incorporating corneal curvature and hysteresis loop area (HLA) provided the best predictive value for Marfan syndrome (AUROC = 0.85). This study describes novel biodynamic features of corneal deformation responses in Marfan syndrome, including increased deformation, decreased bending resistance, and decreased energy dissipation capacity. A predictive model incorporating HLA and corneal curvature shows greatest potential for noninvasive clinical diagnosis of Marfan syndrome. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Corneal Deformation Response and Ocular Geometry: A Non-invasive Diagnostic Strategy in Marfan Syndrome

    PubMed Central

    Beene, Lauren C.; Traboulsi, Elias I.; Seven, Ibrahim; Ford, Matthew R.; Roy, Abhijit Sinha; Butler, Robert S.; Dupps, William J.

    2015-01-01

    Purpose To evaluate corneal air-puff deformation responses and ocular geometry as predictors of Marfan syndrome. Design Prospective observational clinical study Methods Sixteen investigator-derived, 4 standard Ocular Response Analyzer (ORA), and geometric variables from corneal tomography and optical biometry using Oculus Pentacam and IOL Master were assessed for discriminative value in Marfan syndrome, measuring right eyes of 24 control and 13 Marfan syndrome subjects. Area under the receiver operating characteristic (AUROC) curve was assessed in univariate and multivariate analyses Results Six investigator-derived ORA variables successfully discriminated Marfan syndrome. The best lone disease predictor was Concavity Min (Marfan syndrome 47.5 ± 20, control 69 ± 14, p = 0.003; AUROC = 0.80). Corneal hysteresis and corneal resistance factor were decreased (Marfan syndrome CH 9.45 ± 1.62, control CH 11.24 ± 1.21, p = 0.01; Marfan syndrome CRF 9.77 ± 1.65, control CRF 11.03 ± 1.72, p = 0.01) and corneas were flatter in Marfan syndrome (Marfan syndrome Kmean 41.25 ± 2.09 D, control Kmean 42.70 ± 1.81 D, p = 0.046). No significant differences were observed in central corneal thickness, axial eye length, or intraocular pressure. A multivariate regression model incorporating corneal curvature and hysteresis loop area (HLA) provided the best predictive value for Marfan syndrome (AUROC = 0.85). Conclusions This study describes novel biodynamic features of corneal deformation responses in Marfan syndrome, including increased deformation, decreased bending resistance, and decreased energy dissipation capacity. A predictive model incorporating HLA and corneal curvature shows greatest potential for non-invasive clinical diagnosis of Marfan syndrome. PMID:26432567

  13. Biodynamics of copper oxide nanoparticles and copper ions in an oligochaete - Part II: Subcellular distribution following sediment exposure

    USGS Publications Warehouse

    Thit, Amalie; Ramskov, Tina; Croteau, Marie-Noele; Selck, Henriette

    2016-01-01

    The use and likely incidental release of metal nanoparticles (NPs) is steadily increasing. Despite the increasing amount of published literature on metal NP toxicity in the aquatic environment, very little is known about the biological fate of NPs after sediment exposures. Here, we compare the bioavailability and subcellular distribution of copper oxide (CuO) NPs and aqueous Cu (Cu-Aq) in the sediment-dwelling worm Lumbriculus variegatus. Ten days (d) sediment exposure resulted in marginal Cu bioaccumulation in L. variegatus for both forms of Cu. Bioaccumulation was detected because isotopically enriched 65Cu was used as a tracer. Neither burrowing behavior or survival was affected by the exposure. Once incorporated into tissue, Cu loss was negligible over 10 d of elimination in clean sediment (Cu elimination rate constants were not different from zero). With the exception of day 10, differences in bioaccumulation and subcellular distribution between Cu forms were either not detectable or marginal. After 10 d of exposure to Cu-Aq, the accumulated Cu was primarily partitioned in the subcellular fraction containing metallothionein-like proteins (MTLP, ≈40%) and cellular debris (CD, ≈30%). Cu concentrations in these fractions were significantly higher than in controls. For worms exposed to CuO NPs for 10 d, most of the accumulated Cu was partitioned in the CD fraction (≈40%), which was the only subcellular fraction where the Cu concentration was significantly higher than for the control group. Our results indicate that L. variegatus handle the two Cu forms differently. However, longer-term exposures are suggested in order to clearly highlight differences in the subcellular distribution of these two Cu forms.

  14. PCB-induced changes of a benthic community and expected ecosystem recovery following in situ sorbent amendment

    USGS Publications Warehouse

    Janssen, Elisabeth M.-L.; Thompson, Janet K.; Luoma, Samuel N.; Luthy, Richard G.

    2011-01-01

    The benthic community was analyzed to evaluate pollution-induced changes for the polychlorinated biphenyl (PCB)-contaminated site at Hunters Point (HP) relative to 30 reference sites in San Francisco Bay, California, USA. An analysis based on functional traits of feeding, reproduction, and position in the sediment shows that HP is depauperate in deposit feeders, subsurface carnivores, and species with no protective barrier. Sediment chemistry analysis shows that PCBs are the major risk drivers at HP (1,570 ppb) and that the reference sites contain very low levels of PCB contamination (9 ppb). Different feeding traits support the existence of direct pathways of exposure, which can be mechanistically linked to PCB bioaccumulation by biodynamic modeling. The model shows that the deposit feeder Neanthes arenaceodentata accumulates approximately 20 times more PCBs in its lipids than the facultative deposit feeder Macoma balthica and up to 130 times more than the filter feeder Mytilus edulis. The comparison of different exposure scenarios suggests that PCB tissue concentrations at HP are two orders of magnitude higher than at the reference sites. At full scale, in situ sorbent amendment with activated carbon may reduce PCB bioaccumulation at HP by up to 85 to 90% under favorable field and treatment conditions. The modeling framework further demonstrates that such expected remedial success corresponds to exposure conditions suggested as the cleanup goal for HP. However, concentrations remain slightly higher than at the reference sites. The present study demonstrates how the remedial success of a sorbent amendment, which lowers the PCB availability, can be compared to reference conditions and traditional cleanup goals, which are commonly based on bulk sediment concentrations.

  15. In vitro fabrication of a tissue engineered human cardiovascular patch for future use in cardiovascular surgery.

    PubMed

    Yang, Chao; Sodian, Ralf; Fu, Ping; Lüders, Cora; Lemke, Thees; Du, Jing; Hübler, Michael; Weng, Yuguo; Meyer, Rudolf; Hetzer, Roland

    2006-01-01

    One approach to tissue engineering has been the development of in vitro conditions for the fabrication of functional cardiovascular structures intended for implantation. In this experiment, we developed a pulsatile flow system that provides biochemical and biomechanical signals in order to regulate autologous, human patch-tissue development in vitro. We constructed a biodegradable patch scaffold from porous poly-4-hydroxy-butyrate (P4HB; pore size 80 to 150 microm). The scaffold was seeded with pediatric aortic cells. The cell-seeded patch constructs were placed in a self-developed bioreactor for 7 days to observe potential tissue formation under dynamic cell culture conditions. As a control, cell-seeded scaffolds were not conditioned in the bioreactor system. After maturation in vitro, the analysis of the tissue engineered constructs included biochemical, biomechanical, morphologic, and immunohistochemical examination. Macroscopically, all tissue engineered constructs were covered by cells. After conditioning in the bioreactor, the cells were mostly viable, had grown into the pores, and had formed tissue on the patch construct. Electron microscopy showed confluent smooth surfaces. Additionally, we demonstrated the capacity to generate collagen and elastin under in vitro pulsatile flow conditions in biochemical examination. Biomechanical testing showed mechanical properties of the tissue engineered human patch tissue without any statistical differences in strength or resistance to stretch between the static controls and the conditioned patches. Immunohistochemical examination stained positive for alpha smooth muscle actin, collagen type I, and fibronectin. There was minor tissue formation in the nonconditioned control samples. Porous P4HB may be used to fabricate a biodegradable patch scaffold. Human vascular cells attached themselves to the polymeric scaffold, and extracellular matrix formation was induced under controlled biomechanical and biodynamic stimuli in a self-developed pulsatile bioreactor system.

  16. Biodynamic constituents in the Mexican morning glories: purgative remedies transcending boundaries.

    PubMed

    Pereda-Miranda, Rogelio; Bah, Moustapha

    2003-01-01

    Jalap, a pre-Hispanic herbal remedy still considered a useful laxative, is an ingredient in some over-the-counter products sold by herbalists in contemporary Mexico. The purgative crude drugs are prepared from the roots of several morning glories species which all have been identified as members of the Ipomoea genus (Convolvulaceae). Their incorporation as therapeutical agents into Europe is an outstanding example of the assimilation of botanical drugs from the Americas as substitutes for traditional Old World remedies. Phytochemical investigations on the resin glycosides, main constituents of these drugs, were initiated during the second half of the XIX century; however, the structures of their active ingredients had remained poorly known, and still are for some members of these purgative root species. Modern analytical techniques with higher resolution capabilities (HPLC) for the isolation of the active principles of these crude drugs used in conjunction with powerful spectroscopic methods (high field NMR) have facilitated the investigation of these relevant, to the herbal product market, convolvulaceous species during the last decade. The advantages and limitations of theses techniques will be discussed. This review will also describe the ethnobotanical information associated with the Mexican morning glory species and how the traditional usages of these plants have played an important role in the selection of these materials for chemical studies. Little is as yet known about either the mechanism of purge action caused by the resin glycosides or the ecological significance of these same compounds for the producing plants. Over the five centuries of Mexican herbal medicine, one hundred years of phytochemistry has only partially elucidated the active ingredients of the jalap roots but has exemplified how to further contemporary drug discoveries through the investigation of those plants traditionally held to be economically and medicinally important in developing countries.

  17. Effects of Task-Specific Augmented Feedback on Deficit Modification During Performance of the Tuck-Jump Exercise

    PubMed Central

    Stroube, Benjamin W.; Myer, Gregory D.; Brent, Jensen L.; Ford, Kevin R.; Heidt, Robert S.; Hewett, Timothy E.

    2014-01-01

    Context Anterior cruciate ligament (ACL) injuries are prevalent in female athletes. Specific factors have possible links to increasing a female athlete’s chances of suffering an ACL injury. However, it is unclear if augmented feedback may be able to decrease possible risk factors. Objective To compare the effects of task-Specific feedback on a repeated tuck-jump maneuver. Design Double-blind randomized controlled trial. Setting Sports-medicine biodynamics center. Patients 37 female subjects (14.7 ± 1.5 y, 160.9 ± 6.8 cm, 54.5 ± 7.2 kg). Intervention All athletes received standard off-season training consisting of strength training, plyometrics, and conditioning. They were also videotaped during each session while running on a treadmill at a standardized speed (8 miles/h) and while performing a repeated tuck-jump maneuver for 10 s. The augmented feedback group (AF) received feedback on deficiencies present in a 10-s tuck jump, while the control group (CTRL) received feedback on 10-s treadmill running. Main Outcome Measures Outcome measurements of tuck-jump deficits were scored by a blinded rater to determine the effects of group (CTRL vs AF) and time (pre- vs posttesting) on changes in measured deficits. Results A significant interaction of time by group was noted with the task-Specific feedback training (P = .03). The AF group reduced deficits measured during the tuck-jump assessment by 23.6%, while the CTRL training reduced deficits by 10.6%. Conclusions The results of the current study indicate that task-Specific feedback is effective for reducing biomechanical risk factors associated with ACL injury. The data also indicate that Specific components of the tuck-jump assessment are potentially more modifiable than others. PMID:23238301

  18. Finite element modelling of the articular disc behaviour of the temporo-mandibular joint under dynamic loads.

    PubMed

    Jaisson, Maxime; Lestriez, Philippe; Taiar, Redha; Debray, Karl

    2011-01-01

    The proposed biodynamic model of the articular disc joint has the ability to affect directly the complete chewing mechanism process and its related muscles defining its kinematics. When subjected to stresses from the mastication muscles, the disc absorbs one part and redistributes the other to become completely distorted. To develop a realistic model of this intricate joint a CT scan and MRI images from a patient were obtained to create sections (layers) and MRI images to create an anatomical joint CAD model, and its corresponding mesh element using a finite element method. The boundary conditions are described by the external forces applied to the joint model through a decomposition of the maximum muscular force developed by the same individual. In this study, the maximum force was operating at frequencies close to the actual chewing frequency measured through a cyclic loading condition. The reaction force at the glenoid fossa was found to be around 1035 N and is directly related to the frequency of indentation. It is also shown that over the years the areas of maximum stresses are located at the lateral portion of the disc and on its posterior rim. These forces can reach 13.2 MPa after a period of 32 seconds (s) at a frequency of 0.5 Hz. An important part of this study is to highlight resilience and the areas where stresses are at their maximum. This study provides a novel approach to improve the understanding of this complex joint, as well as to assess the different pathologies associated with the disc disease that would be difficult to study otherwise.

  19. Occupant Protection at NASA

    NASA Technical Reports Server (NTRS)

    Somers, Jeffrey; Granderson, Brad; Scheuring, Rick

    2010-01-01

    This slide presentation reviews NASA's efforts to arrive at protection of occupants of the ORION space craft on landing. An Abbreviated Injury Scale (AIS) has been developed, it is an anatomically-based, consensus-derived, global severity scoring system that classifies each injury by body region according to its relative importance on a 6-point ordinal scale. It reviews an Operationmally Relevant Injury Scale (ORIS), a classification methodology, and shows charts that detail the results of applying this ORIS to the injury databases. One chart uses NASCAR injury classification. It discusses providing a context for the level of risk inherent in the Orion landings in terms that people understand and have a sense for. For example is the risk of injury during an Orion landing roughly the same, better or worse than: An aircraft carrier landing, a NASCAR crash, or a helicopter crash, etc? The data for NASCAR and Indy Racing league (IRL) racing crash and injury data was reviewed. The risk from the Air Force, Navy, and Army injury data was also reviewed. Past NASA and the Soyuz programs injury risks are also reviewed. The work is an attempt to formulate a recommendation to the Orion Project for an acceptable level of injury risk associated with Nominal and Off-Nominal landing cases. The presentation also discusses the data mining and use of the data to Validate NASA Operationally-Relevant Injury Scale (NORIS) / Military Operationally-Relevant Injury Scale (MORIS), developing injury risk criteria, the types of data that are required, NASCAR modeling techniques and crash data, and comparison with the Brinkley model. The development of injury risk curves for each biodynamic response parameter is discussed. One of the main outcomes of this work is to establish an accurate Automated Test Dummy (ATD) that can be used to measure human tolerances.

  20. On the Health Risk of the Lumbar Spine due to Whole-Body VIBRATION—THEORETICAL Approach, Experimental Data and Evaluation of Whole-Body Vibration

    NASA Astrophysics Data System (ADS)

    Seidel, H.; Blüthner, R.; Hinz, B.; Schust, M.

    1998-08-01

    The guidance on the effects of vibration on health in standards for whole-body vibration (WBV) does not provide quantitative relationships between WBV and health risk. The paper aims at the elucidation of exposure-response relationships. An analysis of published data on the static and dynamic strength of vertebrae and bone, loaded with various frequencies under different conditions, provided the basis for a theoretical approach to evaluate repetitive loads on the lumbar spine (“internal loads”). The approach enabled the calculation of “equivalent”—with respect to cumulative fatigue failure—combinations of amplitudes and numbers of internal cyclic stress. In order to discover the relation between external peak accelerations at the seat and internal peak loads, biodynamic data of experiments (36 subjects, three somatotypes, two different postures—relaxed and bent forward; random WBV,aw, r.m.s. 1·4 ms-2, containing high transients) were used as input to a biomechanical model. Internal pressure changes were calculated using individual areas of vertebral endplates. The assessment of WBV was based on the quantitative relations between peak accelerations at the seat and pressures predicted for the disk L5/S1. For identical exposures clearly higher rates of pressure rise in the bent forward compared to the relaxed posture were predicted. The risk assessment for internal forces considered the combined internal static and dynamic loads, in relation to the predicted individual strength, and Miner's hypothesis. For exposure durations between 1 min and 8 h, energy equivalent vibration magnitudes (formula B.1, ISO 2631-1, 1997) and equivalent vibration magnitudes according to formula B.2 (time dependence over-energetic) were compared with equivalent combinations of upward peak accelerations and exposure durations according to predicted cumulative fatigue failures of lumbar vertebrae. Formula B.1 seems to underestimate the health risk caused by high magnitudes, formula B.2 is recommended for the evaluation of such conditions.

  1. Grape microbiome as a reliable and persistent signature of field origin and environmental conditions in Cannonau wine production.

    PubMed

    Mezzasalma, Valerio; Sandionigi, Anna; Bruni, Ilaria; Bruno, Antonia; Lovicu, Gianni; Casiraghi, Maurizio; Labra, Massimo

    2017-01-01

    Grape berries harbor a wide range of microbes originating from the vineyard environment, many of which are recognized for their role in the must fermentation process shaping wine quality. To better clarify the contribution of the microbiome of grape fruits during wine fermentation, we used high-throughput sequencing to identify bacterial and fungi communities associated with berries and musts of Cannonau. This is the most important cultivar-wine of Sardinia (Italy) where most vineyards are cultivated without phytochemical treatments. Results suggested that microbiomes of berries collected at four different localities share a core composition characterized by Enterobacteriales, Pseudomonadales, Bacillales, and Rhodospirillales. However, any area seems to enrich berries microbiome with peculiar microbial traits. For example, berries belonging to the biodynamic vineyards of Mamoiada were rich in Bacillales typical of manure (i.e. Lysinibacillus, Bacillus, and Sporosarcina), whereas in the Santadi locality, berries showed soil bacteria such as Pasteurellales and Bacteroidales as well as Rhodospirillales and Lactobacillales which are commonly involved in wine fermentation. In the case of fungi, the most abundant taxa were Dothioraceae, Pleosporaceae, and Saccharomycodaceae, and although the proportion of these families varied among localities, they occurred ubiquitously in all vineyards. During vinification processes performed at the same wine cellar under controlled conditions and without using any yeast starter, more than 50% of bacteria groups of berries reached musts, and each locality had its own private bacteria signature, even if Saccharomyces cerevisiae represented the most abundant fungal species. This work suggests that natural berries microbiome could be influenced by pedoclimatic and anthropologic conditions (e.g., farming management), and the fruits' microorganisms persist during the fermentation process. For these reasons, a reliable wine genotyping should include the entire holobiont (plant and all its symbionts), and bioprospecting activities on grape microbiota could lead to improved viticulture yields and wine quality.

  2. Lessons from a transplantation of zebra mussels into a small urban river: An integrated ecotoxicological assessment.

    PubMed

    Bourgeault, A; Gourlay-Francé, C; Vincent-Hubert, F; Palais, F; Geffard, A; Biagianti-Risbourg, S; Pain-Devin, S; Tusseau-Vuillemin, M-H

    2010-10-01

    It is often difficult to evaluate the level of contamination in small urban rivers because pollution is mainly diffuse, with low levels of numerous substances. The use of a coupled approach using both chemical and biological measurements may provide an integrated evaluation of the impact of micro-pollution on the river. Zebra mussels were transplanted along a metal and organic pollution gradient in spring 2008. For two months, mussels and water samples were collected from two sites every two weeks and analyzed for metal and PAH content as well as water physicochemical parameters. Diffusive gradients in thin film (DGT) were also used to assess levels of labile metals. Exposure of mussels to contaminants and potential impact were evaluated using physiological indices and various biomarkers including condition index (CI), defense mechanisms (glutathione-S-transferase: GST), digestive enzymes (amylase and cellulase) and genotoxicity (micronucleus test: MN and comet assay: CA). For most contaminants, the water contamination was significantly higher downstream. Bioaccumulation in zebra mussels was related to water contamination in the framework of the biodynamic model, which allowed us to take into account the biological dilution that was caused by the growth of soft tissue downstream. Thus, metal influxes were on average two times higher downstream than upstream in particular for Zn, Cr, Cu and Cd. Significant differences in condition index were observed (final CI was 0.42 ± 0.03 downstream and 0.31 ± 0.03 upstream) reflecting a better food availability downstream. Moreover a significant decrease of GST activity and digestive enzymes activity in the cristalline style was observed downstream. Interpreting this decrease requires considering not only micro-pollution but also the trophic status related to the water's physicochemistry. The MN test and the CA on gill cells highlighted genotoxicity in mussels transplanted downstream compared to upstream. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2010.

  3. Trend of Body Compositions with Aging among Chinese Adolescents, Adults and Elders.

    PubMed

    Xu, T; Zhu, G; Han, S

    2015-12-01

    Rare reports can be found about sex- and age-specific body composition survey among Chinese population. The aim of this study is to explore the change of sex-specific body compositions with aging among Chinese adolescents, adults and elders. In a large-scale population survey about physiological constants and health conditions, 75,714 subjects who aged from 8 to 80 completed body composition array. Body mass index (BMI), percentage body fat (PBF), water percentage of body weight (WPBW), water percentage of lean body mass (WPLBM), fat-free mass index (FFMI) and basic metabolic rate were examined with Biodynamics BI-310 body composition analyzer. General obesity is defined as BMI equal to or greater than 28 kg/m2. The prevalence rates of general obesity were 9.4% for males and 7.7% for females respectively. With aging, PBF and FMI showed a U-shape curvilinear trend and WPBW showed a parabolic trend for males. At same age group: 18-19 age groups, PBF and FMI declined to the valley and WPBW rose to the peak. For females, PBF, WPBW and FMI changed in a linear trend. The values of WPLBM and FFMI showed same curvilinear trend for two genders. WPLBM changed in a U-shape trend and touched the valley in twenties for males and in 18-19 age groups for females. The value of FFMI was larger for older age groups in the younger generation but smaller in the older generation. A parabolic trend peaking was seen in the thirties for males and in the forties for females. Regression models with age as independent variable showed that the larger rate of increase of PBF and smaller rates of increase for WPBM and WPLBM with aging for males. This study presents detailed data about sex-specific body composition conditions. Different change trend with aging was found about body composition conditions.

  4. Sequence-based analysis of the Vitis vinifera L. cv Cabernet Sauvignon grape must mycobiome in three South African vineyards employing distinct agronomic systems

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

    Setati, Mathabatha E.; Jacobson, Daniel; Bauer, Florian F.

    Recent microbiomic research of agricultural habitats has highlighted tremendous microbial biodiversity associated with such ecosystems. In addition, data generated in vineyards have furthermore highlighted significant regional differences in vineyard biodiversity, hinting at the possibility that such differences might be responsible for regional differences in wine style and character, a hypothesis referred to as "microbial terroir." The current study further contributes to this body of work by comparing the mycobiome associated with South African (SA) Cabernet Sauvignon grapes in three neighboring vineyards that employ different agronomic approaches, and comparing the outcome with similar data sets from Californian vineyards. The aim ofmore » this study was to fully characterize the mycobiomes associated with the grapes from these vineyards. The data revealed approximately 10 times more fungal diversity than what is typically retrieved from culture-based studies. The Biodynamic vineyard was found to harbor a more diverse fungal community (H = 2.6) than the conventional (H = 2.1) and integrated (H = 1.8) vineyards. The data show that ascomycota are the most abundant phylum in the three vineyards, with Aureobasidium pullulans and its close relative Kabatiella microsticta being the most dominant fungi. This is the first report to reveal a high incidence of K. microsticta in the grape/wine ecosystem. Different common wine yeast species, such as Metschnikowia pulcherrima and Starmerella bacillaris dominated the mycobiome in the three vineyards. The data show that the filamentous fungi are the most abundant community in grape must although they are not regarded as relevant during wine fermentation. Comparison of metagenomic datasets from the three SA vineyards and previously published data from Californian vineyards revealed only 25% of the fungi in the SA dataset was also present in the Californian dataset, with greater variation evident amongst ubiquitous epiphytic fungi.« less

  5. Grape microbiome as a reliable and persistent signature of field origin and environmental conditions in Cannonau wine production

    PubMed Central

    Mezzasalma, Valerio; Sandionigi, Anna; Bruni, Ilaria; Bruno, Antonia; Lovicu, Gianni; Casiraghi, Maurizio

    2017-01-01

    Grape berries harbor a wide range of microbes originating from the vineyard environment, many of which are recognized for their role in the must fermentation process shaping wine quality. To better clarify the contribution of the microbiome of grape fruits during wine fermentation, we used high-throughput sequencing to identify bacterial and fungi communities associated with berries and musts of Cannonau. This is the most important cultivar-wine of Sardinia (Italy) where most vineyards are cultivated without phytochemical treatments. Results suggested that microbiomes of berries collected at four different localities share a core composition characterized by Enterobacteriales, Pseudomonadales, Bacillales, and Rhodospirillales. However, any area seems to enrich berries microbiome with peculiar microbial traits. For example, berries belonging to the biodynamic vineyards of Mamoiada were rich in Bacillales typical of manure (i.e. Lysinibacillus, Bacillus, and Sporosarcina), whereas in the Santadi locality, berries showed soil bacteria such as Pasteurellales and Bacteroidales as well as Rhodospirillales and Lactobacillales which are commonly involved in wine fermentation. In the case of fungi, the most abundant taxa were Dothioraceae, Pleosporaceae, and Saccharomycodaceae, and although the proportion of these families varied among localities, they occurred ubiquitously in all vineyards. During vinification processes performed at the same wine cellar under controlled conditions and without using any yeast starter, more than 50% of bacteria groups of berries reached musts, and each locality had its own private bacteria signature, even if Saccharomyces cerevisiae represented the most abundant fungal species. This work suggests that natural berries microbiome could be influenced by pedoclimatic and anthropologic conditions (e.g., farming management), and the fruits’ microorganisms persist during the fermentation process. For these reasons, a reliable wine genotyping should include the entire holobiont (plant and all its symbionts), and bioprospecting activities on grape microbiota could lead to improved viticulture yields and wine quality. PMID:28892512

  6. Sequence-based Analysis of the Vitis vinifera L. cv Cabernet Sauvignon Grape Must Mycobiome in Three South African Vineyards Employing Distinct Agronomic Systems

    PubMed Central

    Setati, Mathabatha E.; Jacobson, Daniel; Bauer, Florian F.

    2015-01-01

    Recent microbiomic research of agricultural habitats has highlighted tremendous microbial biodiversity associated with such ecosystems. Data generated in vineyards have furthermore highlighted significant regional differences in vineyard biodiversity, hinting at the possibility that such differences might be responsible for regional differences in wine style and character, a hypothesis referred to as “microbial terroir.” The current study further contributes to this body of work by comparing the mycobiome associated with South African (SA) Cabernet Sauvignon grapes in three neighboring vineyards that employ different agronomic approaches, and comparing the outcome with similar data sets from Californian vineyards. The aim of this study was to fully characterize the mycobiomes associated with the grapes from these vineyards. The data revealed approximately 10 times more fungal diversity than what is typically retrieved from culture-based studies. The Biodynamic vineyard was found to harbor a more diverse fungal community (H = 2.6) than the conventional (H = 2.1) and integrated (H = 1.8) vineyards. The data show that ascomycota are the most abundant phylum in the three vineyards, with Aureobasidium pullulans and its close relative Kabatiella microsticta being the most dominant fungi. This is the first report to reveal a high incidence of K. microsticta in the grape/wine ecosystem. Different common wine yeast species, such as Metschnikowia pulcherrima and Starmerella bacillaris dominated the mycobiome in the three vineyards. The data show that the filamentous fungi are the most abundant community in grape must although they are not regarded as relevant during wine fermentation. Comparison of metagenomic datasets from the three SA vineyards and previously published data from Californian vineyards revealed only 25% of the fungi in the SA dataset was also present in the Californian dataset, with greater variation evident amongst ubiquitous epiphytic fungi. PMID:26648930

  7. Sequence-based analysis of the Vitis vinifera L. cv Cabernet Sauvignon grape must mycobiome in three South African vineyards employing distinct agronomic systems

    DOE PAGES

    Setati, Mathabatha E.; Jacobson, Daniel; Bauer, Florian F.

    2015-11-30

    Recent microbiomic research of agricultural habitats has highlighted tremendous microbial biodiversity associated with such ecosystems. In addition, data generated in vineyards have furthermore highlighted significant regional differences in vineyard biodiversity, hinting at the possibility that such differences might be responsible for regional differences in wine style and character, a hypothesis referred to as "microbial terroir." The current study further contributes to this body of work by comparing the mycobiome associated with South African (SA) Cabernet Sauvignon grapes in three neighboring vineyards that employ different agronomic approaches, and comparing the outcome with similar data sets from Californian vineyards. The aim ofmore » this study was to fully characterize the mycobiomes associated with the grapes from these vineyards. The data revealed approximately 10 times more fungal diversity than what is typically retrieved from culture-based studies. The Biodynamic vineyard was found to harbor a more diverse fungal community (H = 2.6) than the conventional (H = 2.1) and integrated (H = 1.8) vineyards. The data show that ascomycota are the most abundant phylum in the three vineyards, with Aureobasidium pullulans and its close relative Kabatiella microsticta being the most dominant fungi. This is the first report to reveal a high incidence of K. microsticta in the grape/wine ecosystem. Different common wine yeast species, such as Metschnikowia pulcherrima and Starmerella bacillaris dominated the mycobiome in the three vineyards. The data show that the filamentous fungi are the most abundant community in grape must although they are not regarded as relevant during wine fermentation. Comparison of metagenomic datasets from the three SA vineyards and previously published data from Californian vineyards revealed only 25% of the fungi in the SA dataset was also present in the Californian dataset, with greater variation evident amongst ubiquitous epiphytic fungi.« less

  8. Yield and Economic Performance of Organic and Conventional Cotton-Based Farming Systems – Results from a Field Trial in India

    PubMed Central

    Forster, Dionys; Andres, Christian; Verma, Rajeev; Zundel, Christine; Messmer, Monika M.; Mäder, Paul

    2013-01-01

    The debate on the relative benefits of conventional and organic farming systems has in recent time gained significant interest. So far, global agricultural development has focused on increased productivity rather than on a holistic natural resource management for food security. Thus, developing more sustainable farming practices on a large scale is of utmost importance. However, information concerning the performance of farming systems under organic and conventional management in tropical and subtropical regions is scarce. This study presents agronomic and economic data from the conversion phase (2007–2010) of a farming systems comparison trial on a Vertisol soil in Madhya Pradesh, central India. A cotton-soybean-wheat crop rotation under biodynamic, organic and conventional (with and without Bt cotton) management was investigated. We observed a significant yield gap between organic and conventional farming systems in the 1st crop cycle (cycle 1: 2007–2008) for cotton (−29%) and wheat (−27%), whereas in the 2nd crop cycle (cycle 2: 2009–2010) cotton and wheat yields were similar in all farming systems due to lower yields in the conventional systems. In contrast, organic soybean (a nitrogen fixing leguminous plant) yields were marginally lower than conventional yields (−1% in cycle 1, −11% in cycle 2). Averaged across all crops, conventional farming systems achieved significantly higher gross margins in cycle 1 (+29%), whereas in cycle 2 gross margins in organic farming systems were significantly higher (+25%) due to lower variable production costs but similar yields. Soybean gross margin was significantly higher in the organic system (+11%) across the four harvest years compared to the conventional systems. Our results suggest that organic soybean production is a viable option for smallholder farmers under the prevailing semi-arid conditions in India. Future research needs to elucidate the long-term productivity and profitability, particularly of cotton and wheat, and the ecological impact of the different farming systems. PMID:24324659

  9. Yield and economic performance of organic and conventional cotton-based farming systems--results from a field trial in India.

    PubMed

    Forster, Dionys; Andres, Christian; Verma, Rajeev; Zundel, Christine; Messmer, Monika M; Mäder, Paul

    2013-01-01

    The debate on the relative benefits of conventional and organic farming systems has in recent time gained significant interest. So far, global agricultural development has focused on increased productivity rather than on a holistic natural resource management for food security. Thus, developing more sustainable farming practices on a large scale is of utmost importance. However, information concerning the performance of farming systems under organic and conventional management in tropical and subtropical regions is scarce. This study presents agronomic and economic data from the conversion phase (2007-2010) of a farming systems comparison trial on a Vertisol soil in Madhya Pradesh, central India. A cotton-soybean-wheat crop rotation under biodynamic, organic and conventional (with and without Bt cotton) management was investigated. We observed a significant yield gap between organic and conventional farming systems in the 1(st) crop cycle (cycle 1: 2007-2008) for cotton (-29%) and wheat (-27%), whereas in the 2(nd) crop cycle (cycle 2: 2009-2010) cotton and wheat yields were similar in all farming systems due to lower yields in the conventional systems. In contrast, organic soybean (a nitrogen fixing leguminous plant) yields were marginally lower than conventional yields (-1% in cycle 1, -11% in cycle 2). Averaged across all crops, conventional farming systems achieved significantly higher gross margins in cycle 1 (+29%), whereas in cycle 2 gross margins in organic farming systems were significantly higher (+25%) due to lower variable production costs but similar yields. Soybean gross margin was significantly higher in the organic system (+11%) across the four harvest years compared to the conventional systems. Our results suggest that organic soybean production is a viable option for smallholder farmers under the prevailing semi-arid conditions in India. Future research needs to elucidate the long-term productivity and profitability, particularly of cotton and wheat, and the ecological impact of the different farming systems.

  10. NASA Occupant Protection Standards Development

    NASA Technical Reports Server (NTRS)

    Somers, Jeffrey T.; Gernhardt, Michael A.; Lawrence, Charles

    2011-01-01

    Current National Aeronautics and Space Administration (NASA) occupant protection standards and requirements are based on extrapolations of biodynamic models, which were based on human tests performed under pre-Space Shuttle human flight programs where the occupants were in different suit and seat configurations than is expected for the Multi Purpose Crew Vehicle (MPCV) and Commercial Crew programs. As a result, there is limited statistical validity to the occupant protection standards. Furthermore, the current standards and requirements have not been validated in relevant spaceflight suit, seat configurations or loading conditions. The objectives of this study were to develop new standards and requirements for occupant protection and rigorously validate these new standards with sub-injurious human testing. To accomplish these objectives we began by determining which critical injuries NASA would like to protect for. We then defined the anthropomorphic test device (ATD) and the associated injury metrics of interest. Finally, we conducted a literature review of available data for the Test Device for Human Occupant Restraint New Technology (THOR-NT) ATD to determine injury assessment reference values (IARV) to serve as a baseline for further development. To better understand NASA s environment, we propose conducting sub-injurious human testing in spaceflight seat and suit configurations with spaceflight dynamic loads, with a sufficiently high number of subjects to validate no injury during nominal landing loads. In addition to validate nominal loads, the THOR-NT ATD will be tested in the same conditions as the human volunteers, allowing correlation between human and ATD responses covering the Orion nominal landing environment and commercial vehicle expected nominal environments. All testing will be conducted without the suit and with the suit to ascertain the contribution of the suit to human and ATD responses. In addition to the testing campaign proposed, additional data analysis is proposed to mine existing human injury and response data from other sources, including military volunteer testing, automotive Crash Injury Research Engineering Network (CIREN), and IndyCar impact and injury data. These data sources can allow a better extrapolation of the ATD responses to off-nominal conditions above the nominal range that can safely be tested. These elements will be used to develop injury risk functions for each of the injury metrics measured from the ATD. These risk functions would serve as the basis for the NASA standards. Finally, we propose defining standard test methodology for evaluating future spacecraft designs against the IARVs, including developing a star-rating system to allow crew safety comparisons between vehicles.

  11. Amyloid-β peptides act as allosteric modulators of cholinergic signalling through formation of soluble BAβACs

    PubMed Central

    Kumar, Rajnish; Nordberg, Agneta

    2016-01-01

    Abstract Amyloid-β peptides, through highly sophisticated enzymatic machinery, are universally produced and released in an action potential synchronized manner into the interstitial fluids in the brain. Yet no native functions are attributed to amyloid-β. The amyloid-β hypothesis ascribes just neurotoxicity properties through build-up of soluble homomeric amyloid-β oligomers or fibrillar deposits. Apolipoprotein-ε4 (APOE4) allele is the only confirmed genetic risk factor of sporadic Alzheimer’s disease; once more it is unclear how it increases the risk of Alzheimer’s disease. Similarly, central cholinergic signalling is affected selectively and early in the Alzheimer’s disease brain, again why cholinergic neurons show this sensitivity is still unclear. However, the three main known Alzheimer’s disease risk factors, advancing age, female gender and APOE4, have been linked to a high apolipoprotein-E and accumulation of the acetylcholine degrading enzyme, butyrylcholinesterase in cerebrospinal fluids of patients. Furthermore, numerous reports indicate that amyloid-β interacts with butyrylcholinesterase and apolipoprotein-E. We have proposed that this interaction leads to formation of soluble ultrareactive acetylcholine-hydrolyzing complexes termed BAβACs, to adjust at demand both synaptic and extracellular acetylcholine signalling. This hypothesis predicted presence of acetylcholine-synthesizing enzyme, choline acetyltransferase in extracellular fluids to allow maintenance of equilibrium between breakdown and synthesis of acetylcholine through continuous in situ syntheses. A recent proof-of-concept study led to the discovery of this enzyme in the human extracellular fluids. We report here that apolipoprotein-E, in particular ε4 isoprotein acts as one of the strongest endogenous anti-amyloid-β fibrillization agents reported in the literature. At biological concentrations, apolipoprotein-E prevented amyloid-β fibrillization for at least 65 h. We show that amyloid-β interacts readily in an apolipoprotein-facilitated manner with butyrylcholinesterase, forming highly stable and soluble complexes, BAβACs, which can be separated in their native states by sucrose density gradient technique. Enzymological analyses further evinced that amyloid-β concentration dependently increased the acetylcholine-hydrolyzing capacity of cholinesterases. In silico biomolecular analysis further deciphered the allosteric amino acid fingerprint of the amyloid-β-cholinesterase molecular interaction in formation of BAβACs. In the case of butyrylcholinesterase, the results indicated that amyloid-β interacts with a putative activation site at the mouth of its catalytic tunnel, most likely leading to increased acetylcholine influx into the catalytic site, and thereby increasing the intrinsic catalytic rate of butyrylcholinesterase. In conclusion, at least one of the native physiological functions of amyloid-β is allosteric modulation of the intrinsic catalytic efficiency of cholinesterases, and thereby regulation of synaptic and extrasynaptic cholinergic signalling. High apolipoprotein-E may pathologically alter the biodynamics of this amyloid-β function. PMID:26525916

  12. Conveyor belt biomantles: Centripetal bioturbation coupled with erosional downwasting -- an explanatory model

    NASA Astrophysics Data System (ADS)

    Johnson, D. L.; Johnson, D. N.

    2012-12-01

    Science advances on the strength of clarifying and unifying concepts, models, and methodologies that enhance and expand our explanatory paradigms. If valid, such structures allow us to accurately understand and appreciate how the world works. To aid in this task, new term-concepts must sometimes be coined and formalized. To understand certain ubiquitously occurring -- though as yet un-conceptualized -- surface processes that operate non-stop, and assessing their efficacies, is a desirable goal in landscape evolution studies. All near-surface processes are, of course, biological, chemical, and or physical in nature, and many if not most operate in combination. But of this triumvirate, biological processes, both biochemical and biomechanical (bioturbations), are perhaps least understood. Combinations of ubiquitously and semi-continuously occurring poorly understood processes that are both obscure and yet obvious have collectively produced Earth's biomantle. The biomantle occupies the uppermost Pedosphere, is a planet-wide layer, and unique to Earth. It thus functions as the biogenically habitable interface between the Atmosphere, Biosphere, Hydrosphere, and Lithosphere. The biomantle is defined as the organic-bearing bioturbated upper part of soil, including the topsoil, and of subaqueous substrates (lake, stream, ocean floor sediments) where most biota live, operate, move, wriggle, rest, sleep, estivate, seek food, eat, compete, fight, hide, reproduce, die, and assimilate. Its position and function in the uppermost soil layer of the Critical Zone must modulate and mediate much or most of what takes place above and below in ways yet to be established. In an attempt to increase understanding of this complicated biodynamic pedomembrane, and to identify the main processes that produce it, we present an iterative process model that pits ongoing cyclic bioturbation driven constructional processes against ongoing cyclic physically driven destructional processes. More specifically, and in summary, we present a model that displays how semi-continuous biomechanical and centripetally driven constructional soil-sediment biotransfers to raised animal-produced point centers are concomitantly leveled by physical-erosional centrifugally driven, lateral-radial downwasting processes. The model is analogous to a cyclical conveyor belt system of soil-sediment biotransfers to, then erosionally away, from innumerably raised point centers, the "activity centers" of burrowing animals. Career-spanning fieldwork across many tropical, subtropical, and mid-latitude environments strongly support the overall validity of the model. Apart from microbes, animals represent the most diverse organismic group on the planet, with plants and fungi distant seconds. Moreover, many if not most spend at least part of their existence living on and/or in soil and sediment, which includes both the subaerial and subaqueous realms of Earth (that is, all of it, except extreme polar areas). Animals bioturbate, vertically and laterally, and likely have done so since pre-Cambrian time. The fundamental conveyor belt process, where ongoing centripetal bioturbations are coupled with ongoing erosional wasting and spreading, joined by subsidiary processes, drives biomantle formation.

  13. The coastal oasis: ice age springs on emerged continental shelves

    NASA Astrophysics Data System (ADS)

    Faure, Hugues; Walter, Robert C.; Grant, Douglas R.

    2002-06-01

    As ice caps expanded during each of the last five glaciations, sea level fell at least 120 m below current levels, exposing continental shelves worldwide to create vast areas of new land. As a result of this exposure, the ecology, climate, pedology, and geology of global shorelines were dramatically transformed, which in turn altered the carbon cycle and biodynamics of this new landmass. In this paper, we focus on a little-known hydrogeological phenomenon that may have had profound influences on biodiversity, human evolution, and carbon storage during periods of severe climatic stress of the Pleistocene Ice Ages. We propose that freshwater springs appeared on emerged continental shelves because falling sea level not only drew down and steepened the coastal water table gradient, thus increasing the hydrostatic head on inland groundwater aquifers, but also removed up to 120 m of hydrostatic pressure on the shelf, further enhancing groundwater flow. We call this phenomenon the "coastal oasis", a model based on three well-established facts. (1) In all coastal areas of the world, continental aquifers discharge a continuous flow of fresh water to the oceans. (2) Many submarine sedimentary and morphological features, as well as seepages and flow of fresh water, are known on and below the shelves from petroleum explorations, deep-sea drilling programs, and mariners' observations. (3) Hydraulic principles (Darcy's law) predict increased groundwater flow at the coast when sea level drops because the piezometric head increases by the equivalent depth of sea-level lowering. Sea level is presently in a relatively high interglacial position. Direct observation and verification of our model is difficult and must rely on explorations of terrain that are now deeply submerged on continental shelves. For this reason, we draw parallels between our predicted model and simple, well-exposed terrestrial hydrological systems, such as present-day springs that appear on the exposed shores of lakes whose free-air water levels fell during periods of aridity. Such modern examples are seen in the Caspian Sea and Dead Sea, the Afar Depression, and the Sahara Desert. These modern analogues demonstrate the likelihood that underground water will be more abundant on emerged shelves during sea-level fall, causing springs, oases, and wetlands to appear. Our model creates an apparent paradox: in tropical and subtropical arid lands, such as most of Africa, sea-level fall during hyperarid glacial phases would produce abundant fresh water flow onto emerged continental shelves as the continental interior desiccated. Thus, emergent shoreline springs provided new habitats for terrestrial vegetation and animals displaced from the interior by increasingly arid conditions, shrinking ecosystems, and dwindling water supplies. Such a scenario would have had a profound influence on the vegetation that spreads naturally to colonize the emerged shelves during glacio-eustatic sea-level lowstands, as well as creating new habitats for terrestrial mammals, including early humans.

  14. Soil properties and not inputs control carbon : nitrogen : phosphorus ratios in cropped soils in the long term

    NASA Astrophysics Data System (ADS)

    Frossard, Emmanuel; Buchmann, Nina; Bünemann, Else K.; Kiba, Delwende I.; Lompo, François; Oberson, Astrid; Tamburini, Federica; Traoré, Ouakoltio Y. A.

    2016-02-01

    Stoichiometric approaches have been applied to understand the relationship between soil organic matter dynamics and biological nutrient transformations. However, very few studies have explicitly considered the effects of agricultural management practices on the soil C : N : P ratio. The aim of this study was to assess how different input types and rates would affect the C : N : P molar ratios of bulk soil, organic matter and microbial biomass in cropped soils in the long term. Thus, we analysed the C, N, and P inputs and budgets as well as soil properties in three long-term experiments established on different soil types: the Saria soil fertility trial (Burkina Faso), the Wagga Wagga rotation/stubble management/soil preparation trial (Australia), and the DOK (bio-Dynamic, bio-Organic, and "Konventionell") cropping system trial (Switzerland). In each of these trials, there was a large range of C, N, and P inputs which had a strong impact on element concentrations in soils. However, although C : N : P ratios of the inputs were highly variable, they had only weak effects on soil C : N : P ratios. At Saria, a positive correlation was found between the N : P ratio of inputs and microbial biomass, while no relation was observed between the nutrient ratios of inputs and soil organic matter. At Wagga Wagga, the C : P ratio of inputs was significantly correlated to total soil C : P, N : P, and C : N ratios, but had no impact on the elemental composition of microbial biomass. In the DOK trial, a positive correlation was found between the C budget and the C to organic P ratio in soils, while the nutrient ratios of inputs were not related to those in the microbial biomass. We argue that these responses are due to differences in soil properties among sites. At Saria, the soil is dominated by quartz and some kaolinite, has a coarse texture, a fragile structure, and a low nutrient content. Thus, microorganisms feed on inputs (plant residues, manure). In contrast, the soil at Wagga Wagga contains illite and haematite, is richer in clay and nutrients, and has a stable structure. Thus, organic matter is protected from mineralization and can therefore accumulate, allowing microorganisms to feed on soil nutrients and to keep a constant C : N : P ratio. The DOK soil represents an intermediate situation, with high nutrient concentrations, but a rather fragile soil structure, where organic matter does not accumulate. We conclude that the study of C, N, and P ratios is important to understand the functioning of cropped soils in the long term, but that it must be coupled with a precise assessment of element inputs and budgets in the system and a good understanding of the ability of soils to stabilize C, N, and P compounds.

  15. [The Omega "Omega" pulley plasty: a new technique for the surgical management of the De Quervain's disease].

    PubMed

    Bakhach, J; Sentucq-Rigal, J; Mouton, P; Boileau, R; Panconi, B; Guimberteau, J-C

    2006-02-01

    The Omega "Omega" pulley plasty: a new technique for the surgical management of the De Quervain's disease. The De Quervain tenosynovitis is an inadequacy into the first extensor compartment between the osteo-fibrous tunnel and the tendons. This mechanical conflict generates a tenosynovitis of the extensor pollicis brevis and the abductor pollicis longus tendons. This is generally expressed by a tenderness on the radial side of the wrist over the radial styloid process. The medical management consists on corticoids infiltrations of the first extensor compartment, the avoidance of repetitive and stress movements of the first ray with the use of a rest splint. The surgical approach is considered with the recurrence of the painful symptoms. This well-known pathology is reputated to require a simple section of the pulley. Our post-operative complications have been reported in the literature of this classical surgical solution. These complications concern an incomplete release of the extensor pollicis brevis and the abductor pollicis longus tendons particularly when an extensor sub-compartment exists and was overlooked, an irritation of the collateral branches of the sensitive radial nerve or the occurrence of a nevroma after a nerve injury and the most serious complication is a palmar subluxation of the extensor tendons which can occur with the thumb extended and the wrist flexed. In rare cases, this subluxation can be really painful and requires a surgical management with secondary reconstruction of the pulley. This reconstruction necessitates distal pedicle flaps from the dorsal retinaculum or the brachioradialis tendon. To prevent these complications, Codega and Kapandji described techniques of reconstruction of the pulley after its release. More recently, Le Viet reported a procedure using the anterior flap of the pulley; fixed to the dermis it will work as a barrier and maintain the tendons sliding on the radial styloid groove. These techniques require to divide the pulley and to reconstruct it suturing the different flaps. It can generate adherences between the extensor tendons, the overlying skin and the collateral branches of the radial nerve. The authors present a new and original plasty procedure of the first extensor compartment pulley, the "Omega" Omega plasty. It consists to liberate the anterior attachment of the pulley over the anterior lip of the styloïd process respecting its continuity with the periosteum flap. This conservative procedure is very interesting; it permits enough expansion of the tunnel volume decompressing the extensor tendons as a treatment of the De Quervain disease and respecting the anatomy and the continuity of the osteo-fibrous tunnel. This technique is simple, reliable and respects the first ray extensor tendons gliding physiology and biodynamic. In spite of our short clinical experience with only ten cases, all the patients retrieve a normal function of the thumb with complete disappearance of the first ray tenderness and pain without any complications. These preliminary results are encouraging and push us to consider the "Omega" plasty as a first choice for the surgical treatment of the De Quervain tenosynovitis.

  16. Detection of bacteriuria and pyuria by URISCREEN a rapid enzymatic screening test.

    PubMed Central

    Pezzlo, M T; Amsterdam, D; Anhalt, J P; Lawrence, T; Stratton, N J; Vetter, E A; Peterson, E M; de la Maza, L M

    1992-01-01

    A multicenter study was performed to evaluate the ability of the URISCREEN (Analytab Products, Plainview, N.Y.), a 2-min catalase tube test, to detect bacteriuria and pyuria. This test was compared with the Chemstrip LN (BioDynamics, Division of Boehringer Mannheim Diagnostics, Indianapolis, Ind.), a 2-min enzyme dipstick test; a semiquantitative plate culture method was used as the reference test for bacteriuria, and the Gram stain or a quantitative chamber count method was used as the reference test for pyuria. Each test was evaluated for its ability to detect probable pathogens at greater than or equal to 10(2) CFU/ml and/or greater than or equal to 1 leukocyte per oil immersion field, as determined by the Gram stain method, or greater than 10 leukocytes per microliter, as determined by the quantitative count method. A total of 1,500 urine specimens were included in this evaluation. There were 298 specimens with greater than or equal 10(2) CFU/ml and 451 specimens with pyuria. Of the 298 specimens with probable pathogens isolated at various colony counts, 219 specimens had colony counts of greater than or equal to 10(5) CFU/ml, 51 specimens had between 10(4) and 10(5) CFU/ml, and 28 specimens had between 10(2) and less than 10(4) CFU/ml. Both the URISCREEN and the Chemstrip LN detected 93% (204 of 219) of the specimens with probable pathogens at greater than or equal to 10(5) CFU/ml. For the specimens with probable pathogens at greater than or equal to 10(2) CFU/ml, the sensitivities of the URISCREEN and the Chemstrip LN were 86% (256 of 298) and 81% (241 of 298), respectively. Of the 451 specimens with pyuria, the URISCREEN detected 88% (398 of 451) and Chemstrip LN detected 78% (350 if 451). There were 204 specimens with both greater than or equal to 10(2) CFU/ml and pyuria; the sensitivities of both methods were 95% (193 of 204) for these specimens. Overall, there were 545 specimens with probable pathogens at greater than or equal to 10(2) CFU/ml and/or pyuria. The URISCREEN detected 85% (461 of 545), and the Chemstrip LN detected 73% (398 of 545). A majority (76%) of the false-negative results obtained with either method were for specimens without leukocytes in the urine. There were 955 specimens with no probable pathogens or leukocytes. Of these, 28% (270 of 955) were found positive by the URISCREEN and 13% (122 of 955) were found positive by the Chemstrip LN. A majority of the false-positive results were probably due, in part, to the detection of enzymes present in both bacterial and somatic cells by each of the test systems. Overall, the URISCREEN is rapid, manual, easy-to-perform enzymatic test that yields findings similar to those yielded by the Chemstrip LN for specimens with both greater than or equal to 10(2) CFU/ml and pyuria or for specimens with greater than or equal to 10(5) CFU/ml and with or without pyuria. However, when the data were analyzed for either probable pathogens at less 10(5) CFU/ml or pyuria, the sensitivity of the URISCREEN was higher (P less than 0.05). PMID:1551986

  17. Modular use of human body models of varying levels of complexity: Validation of head kinematics.

    PubMed

    Decker, William; Koya, Bharath; Davis, Matthew L; Gayzik, F Scott

    2017-05-29

    The significant computational resources required to execute detailed human body finite-element models has motivated the development of faster running, simplified models (e.g., GHBMC M50-OS). Previous studies have demonstrated the ability to modularly incorporate the validated GHBMC M50-O brain model into the simplified model (GHBMC M50-OS+B), which allows for localized analysis of the brain in a fraction of the computation time required for the detailed model. The objective of this study is to validate the head and neck kinematics of the GHBMC M50-O and M50-OS (detailed and simplified versions of the same model) against human volunteer test data in frontal and lateral loading. Furthermore, the effect of modular insertion of the detailed brain model into the M50-OS is quantified. Data from the Navy Biodynamics Laboratory (NBDL) human volunteer studies, including a 15g frontal, 8g frontal, and 7g lateral impact, were reconstructed and simulated using LS-DYNA. A five-point restraint system was used for all simulations, and initial positions of the models were matched with volunteer data using settling and positioning techniques. Both the frontal and lateral simulations were run with the M50-O, M50-OS, and M50-OS+B with active musculature for a total of nine runs. Normalized run times for the various models used in this study were 8.4 min/ms for the M50-O, 0.26 min/ms for the M50-OS, and 0.97 min/ms for the M50-OS+B, a 32- and 9-fold reduction in run time, respectively. Corridors were reanalyzed for head and T1 kinematics from the NBDL studies. Qualitative evaluation of head rotational accelerations and linear resultant acceleration, as well as linear resultant T1 acceleration, showed reasonable results between all models and the experimental data. Objective evaluation of the results for head center of gravity (CG) accelerations was completed via ISO TS 18571, and indicated scores of 0.673 (M50-O), 0.638 (M50-OS), and 0.656 (M50-OS+B) for the 15g frontal impact. Scores at lower g levels yielded similar results, 0.667 (M50-O), 0.675 (M50-OS), and 0.710 (M50-OS+B) for the 8g frontal impact. The 7g lateral simulations also compared fairly with an average ISO score of 0.565 for the M50-O, 0.634 for the M50-OS, and 0.606 for the M50-OS+B. The three HBMs experienced similar head and neck motion in the frontal simulations, but the M50-O predicted significantly greater head rotation in the lateral simulation. The greatest departure from the detailed occupant models were noted in lateral flexion, potentially indicating the need for further study. Precise modeling of the belt system however was limited by available data. A sensitivity study of these parameters in the frontal condition showed that belt slack and muscle activation have a modest effect on the ISO score. The reduction in computation time of the M50-OS+B reduces the burden of high computational requirements when handling detailed HBMs. Future work will focus on harmonizing the lateral head response of the models and studying localized injury criteria within the brain from the M50-O and M50-OS+B.

  18. Phosphorus (P) balances and P availability in a field trial comparing organic and conventional farming systems since 35 years

    NASA Astrophysics Data System (ADS)

    Jarosch, Klaus; Oberson, Astrid; Emmanuel, Frossard; Gunst, Lucie; Dubois, David; Mäder, Paul; Mayer, Jochen

    2017-04-01

    Background: The adequate supply with phosphorus (P) is crucial to maintain constant yields in all cropping systems. It remains yet unclear whether P in organic farming systems may become a limiting factor for plant nutrition in the long term. Material and Methods: The DOK long-term field trial was established in 1978 to compare different farming systems. The trial consists of two organic (biodynamic (DYN), bioorganic (ORG)) and two conventional treatments (using farmyard manure plus mineral fertilizer (KON) and mineral fertilizer only (MIN, established in 1985)). In a control treatment (NON) no fertilizer is applied. The fertilization for the organic treatments DYN and ORG is defined on manure production of 1.4 livestock units (since 1992), while before that 1.2 livestock units were used as reference. Fertilization on the conventional treatments KON and MIN is defined by Swiss fertilization guidelines. Treatments DYN, ORG and KON are maintained at full fertilization level (2) as well as halved fertilization level (1) while treatment MIN is only maintained at fertilization level 2. All treatments are maintained with the same crop rotation with a period of 7 years. An annual P-balance was calculated, based on the input factors 1) fertilization, 2) seeds and 3) deposition and the output factors 4) removal with crop yields and 5) leaching. The factors fertilization and removal with crop yields were based on documentation since trial establishment. Factor seeds was estimated based on documented quantity of used seeds per treatment and factors deposition and leaching were estimated by values available in literature. Additionally, P availability was determined via isotopic exchange kinetics (IEK) experiments after each crop rotation period (7 years). The IEK experiments allow to estimate the rate of P exchange from soil into soil solution and thus to estimate plant P availability over a cropping period. Results and Conclusions: Main influencing parameters of the P-balance were the factors fertilization and the removal with cropping products. Other inputs (deposition, seeds) and outputs (leaching) were of minor importance for the outcome of the balance for all treatments. For the treatments KON2 and M we observed a slightly positive P-balance of 3 and 6 kg ha-1 year-1, respectively. All other treatments showed a negative P-balance, even in the systems with high fertilization levels (DYN2 and ORG2). The deficit in the P-balance was even more pronounced in the farming systems with reduced fertilizer application rates DYN1, ORG1 and KON1 (-11 to -13 kg ha-1 year-1). The unfertilized control (NON) showed the highest deficit with -19 kg ha-1 year-1. The calculated P-balance suggests that the full fertilization level in treatments DYN2 and ORG2 is not sufficient to mitigate the entire P removal. This deficit is even more pronounced on treatments with less fertilization. In the long term, this fertilization practice may lead to P limitation, especially in the organic treatments. Phosphorus availability determined by IEK in the top soil (0-20 cm) declined with time in all treatments. This decline may currently already limit crop yield in some farming systems, yet, a redistribution of P from deeper soil layers seems to mitigate this limitation. Additionally, the relatively high P-status in the soil prior to initiation of the DOK trial may currently still buffer against P-limitation for plants. The results of this study will be discussed in regard to sustainable P use in different farming systems.

Top