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Sample records for biological effects experiments

  1. Correlation of microdosimetric measurements with relative biological effectiveness from clinical experience for two neutron therapy beams

    International Nuclear Information System (INIS)

    Stinchcomb, T.G.; Kuchnir, F.T.; Myrianthopoulos, L.C.; Horton, J.L. Jr.; Roberts, W.K.

    1986-01-01

    Microdosimetric measurements were made for the neutron therapy beams at the University of Chicago and at the Cleveland Clinic with the same geometry and phantom material using the same tissue-equivalent spherical proportional counter and standard techniques. The energy deposition spectra (dose distributions in lineal energy) are compared for these beams and for their scattered components (direct beam blocked). The model of dual radiation action (DRA) of Kellerer and Rossi is employed to interpret these data in terms of biological effectiveness over this limited range of radiation qualities. The site-diameter parameter of the DRA theory is determined for the Cleveland beam by setting the biological effectiveness (relative to 60 Co gamma radiation) equal to the relative biological effectiveness value deduced from radiobiology experiments and clinical experience. The resulting value of this site-diameter parameter is then used to predict the biological effectiveness of the Chicago beam. The prediction agrees with the value deduced from radiobiology and clinical experience. The biological effectiveness of the scattered components of both beams is also estimated using the model

  2. Biological effects

    International Nuclear Information System (INIS)

    Trott, K.R.

    1973-01-01

    Following an introduction into the field of cellular radiation effect considering the most important experimental results, the biological significance of the colony formation ability is brought out. The inactivation concept of stem cells does not only prove to be good, according to the present results, in the interpretation of the pathogenesis of acute radiation effects on moult tissue, it also enables chronicle radiation injuries to be interpreted through changes in the fibrous part of the organs. Radiation therapy of tumours can also be explained to a large extent by the radiation effect on the unlimited reproductiveness of tumour cells. The more or less similar dose effect curves for healthy and tumour tissue in practice lead to intermittent irradiation. The dependence of the intermittent doses and intervals on factors such as Elkind recovery, synchronisation, redistribution, reoxygenation, repopulation and regeneration are reviewed. (ORU/LH) [de

  3. Biological effects of radiation

    International Nuclear Information System (INIS)

    2013-01-01

    This fourth chapter presents: cell structure and metabolism; radiation interaction with biological tissues; steps of the production of biological effect of radiation; radiosensitivity of tissues; classification of biological effects; reversibility, transmissivity and influence factors; pre-natal biological effects; biological effects in therapy and syndrome of acute irradiation

  4. Biological effects of the hypomagnetic field: An analytical review of experiments and theories.

    Directory of Open Access Journals (Sweden)

    Vladimir N Binhi

    Full Text Available During interplanetary flights in the near future, a human organism will be exposed to prolonged periods of a hypomagnetic field that is 10,000 times weaker than that of Earth's. Attenuation of the geomagnetic field occurs in buildings with steel walls and in buildings with steel reinforcement. It cannot be ruled out also that a zero magnetic field might be interesting in biomedical studies and therapy. Further research in the area of hypomagnetic field effects, as shown in this article, is capable of shedding light on a fundamental problem in biophysics-the problem of primary magnetoreception. This review contains, currently, the most extensive bibliography on the biological effects of hypomagnetic field. This includes both a review of known experimental results and the putative mechanisms of magnetoreception and their explanatory power with respect to the hypomagnetic field effects. We show that the measured correlations of the HMF effect with HMF magnitude and inhomogeneity and type and duration of exposure are statistically absent. This suggests that there is no general biophysical MF target similar for different organisms. This also suggests that magnetoreception is not necessarily associated with evolutionary developed specific magnetoreceptors in migrating animals and magnetotactic bacteria. Independently, there is nonspecific magnetoreception that is common for all organisms, manifests itself in very different biological observables as mostly random reactions, and is a result of MF interaction with magnetic moments at a physical level-moments that are present everywhere in macromolecules and proteins and can sometimes transfer the magnetic signal at the level of downstream biochemical events. The corresponding universal mechanism of magnetoreception that has been given further theoretical analysis allows one to determine the parameters of magnetic moments involved in magnetoreception-their gyromagnetic ratio and thermal relaxation time

  5. Radiation, its biological effects and uses: past experiences and future perspectives

    International Nuclear Information System (INIS)

    Bharti, Neha; Pande, Nivedita

    2012-01-01

    Radiation refers to electromagnetic energy that travels through space in the form of particles or waves. It is energy such as heat, light, sound, radio waves and radar. It is everywhere including in the food we eat and the air that we breathe. Biological effects of radiation including cell killing, mutagenesis and carcinogenesis are all due to damage to DNA; Radiation releases OH ions from water molecules, which cause the cell damage due to their oxidizing effect. The mechanism by which radiation causes damage to human tissue, or any other material, is by ionization of atoms in the material. Genetic or heritable effects appear in the future generations of the exposed person as a result of radiation damage to the reproductive cells. Radiation may alter the DNA within any cell. Cell damage and death that result from mutations in somatic cells occur only in the organism in which the mutation occurred and are therefore termed somatic or no heritable effects. Acute radiation dose is defined as a large dose delivered during a short period of time. Genetic or heritable effects appear in the future generations of the exposed person as a result of radiation damage to the reproductive cells. The radiation used for cancer treatment may come from a machine outside the body, or it may come from radioactive material placed in the body near tumor cells or injected into the bloodstream. Radiation is used to help remove toxic pollutants, such as exhaust gases from coal-fired power stations and industry. For example, electron beam radiation can remove dangerous sulphur dioxides and nitrogen oxides from our environment and used to help remove toxic pollutants, such as exhaust gases from coal-fired power stations and industry. (author)

  6. Biological Effectiveness of Antiproton Annihilation

    DEFF Research Database (Denmark)

    Maggiore, C.; Agazaryan, N.; Bassler, N.

    2004-01-01

    from the annihilation of antiprotons produce an increase in ‘‘biological dose’’ in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct measurement of the biological effects of antiproton annihilation. The background, description, and status...

  7. Biological effectiveness of antiproton annihilation

    CERN Document Server

    Holzscheiter, Michael H.; Bassler, Niels; Beyer, Gerd; De Marco, John J.; Doser, Michael; Ichioka, Toshiyasu; Iwamoto, Keisuke S.; Knudsen, Helge V.; Landua, Rolf; Maggiore, Carl; McBride, William H.; Møller, Søren Pape; Petersen, Jorgen; Smathers, James B.; Skarsgard, Lloyd D.; Solberg, Timothy D.; Uggerhøj, Ulrik I.; Withers, H.Rodney; Vranjes, Sanja; Wong, Michelle; Wouters, Bradly G.

    2004-01-01

    We describe an experiment designed to determine whether or not the densely ionizing particles emanating from the annihilation of antiprotons produce an increase in “biological dose” in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct measurement of the biological effects of antiproton annihilation. The experiment has been approved by the CERN Research Board for running at the CERN Antiproton Decelerator (AD) as AD-4/ACE (Antiproton Cell Experiment) and has begun data taking in June of 2003. The background, description and the current status of the experiment are given.

  8. Biological effects of neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Ogiu, Toshiaki; Ohmachi, Yasushi; Ishida, Yuka [National Inst. of Radiological Sciences, Chiba (JP)] [and others

    2003-03-01

    Although the occasion to be exposed to neutrons is rare in our life, except for nuclear accidents like in the critical accident at Tokai-mura in 1999, countermeasures against accident should be always prepared. In the Tokai-mura accident, residents received less than 21 mSv of neutrons and gamma rays. The cancer risks and fetal effects of low doses of neutrons were matters of concern among residents. The purpose of this program is to investigate the relative biological effectiveness (RBE) for leukemias, and thereby to assess risks of neutrons. Animal experiments are planed to obtain the following RBEs: (1) RBE for the induction of leukemias in mice and (2) RBE for effects on fetuses. Cyclotron fast neutrons (10 MeV) and electrostatic accelerator-derived neutrons (2 MeV) are used for exposure in this program. Furthermore, cytological and cytogenetic analyses will be performed. (author)

  9. The effects of autonomy-supportive and controlling teaching behaviour in biology lessons with primary and secondary experiences on students' intrinsic motivation and flow-experience

    Science.gov (United States)

    Hofferber, Natalia; Basten, Melanie; Großmann, Nadine; Wilde, Matthias

    2016-09-01

    Self-Determination Theory and Flow Theory propose that perceived autonomy fosters the positive qualities of motivation and flow-experience. Autonomy-support can help to maintain students' motivation in very interesting learning activities and may lead to an increase in the positive qualities of motivation in less interesting learning activities. This paper investigates whether autonomy-supportive or controlling teaching behaviour influence students' motivation and flow-experience in biology class. In study 1, 158 students of grade six worked on the adaptations of Harvest Mice (Micromys minutus) with living animals. The 153 sixth graders of study 2 dealt with the same content but instead worked with short films on laptops. Previous studies have shown that students perceive film sequences as less interesting than working with living animals. Students' intrinsic motivation and flow-experience were measured at the end of the first and the third lesson. In study 1, autonomy-supportive teaching behaviour led to significant differences in students' intrinsic motivation and flow-experience when compared to controlling teaching behaviour. In study 2, motivation and flow-experience were not always in line with theory. The positive effects of autonomy-supportive and the non-beneficial effects of the controlling teaching behaviour seem to be dependent on the interestingness of the teaching material.

  10. Biological effectiveness of antiproton annihilation

    DEFF Research Database (Denmark)

    Holzscheiter, M.H.; Agazaryan, N.; Bassler, Niels

    2004-01-01

    We describe an experiment designed to determine whether or not the densely ionizing particles emanating from the annihilation of antiprotons produce an increase in ‘‘biological dose’’ in the vicinity of the narrow Bragg peak for antiprotons compared to protons. This experiment is the first direct...... measurement of the biological effects of antiproton annihilation. The experiment has been approved by the CERN Research Board for running at the CERN Antiproton Decelerator (AD) as AD-4/ACE (Antiproton Cell Experiment) and has begun data taking in June of 2003. The background, description and the current...

  11. Animal experiment studies on biological and chemical radiation protection - the combined effects of serotonin and erythropoletin

    International Nuclear Information System (INIS)

    Sasse, U.

    1975-01-01

    The influence of a prophylactic combination treatment with serotonin and erythropoietin on the inhibited erythropoiesis of whole-body irradiated mice (500 R) was studied. Both erythropoietin and serotonin turned out to compensate the radiation-induced inhibition of the formation rate for erythrocytes to a small extent. However, only the enhancement of erythropoiesis due to serotonin indicated significant values. Yet the combined application of the named substances yielded a distinct and significant effect in radiation protection which even exceeded the simple addition of the protective effect yielded by serotonin and erythropoietin alone. But despite of this considerable success the radiation damage in the erythropoietic system was not even half compensated for. (orig./MG) [de

  12. Biological effects like cancer formation due to inhalational exposure to plutonium. What are evident in animal experiments?

    International Nuclear Information System (INIS)

    Oghiso, Yoichi

    2013-01-01

    Literatures on the title subject are reviewed and problems to be solved are given. There are 2 reports of dog experiments of inhaled Pu by Pacific Northwest Laboratory (PNL), which have given results incompatible/compatible with risk assessments hitherto: one with the micro-particle of Pu-nitrate, 239 Pu(NO 3 ) 4 , in which the dog lung is compared with human's by histology and autoradiography, presenting findings that differ from the previous ICRP assumption of the homogeneous distribution in the lung; and the other with 239 PuO 2 , indicating that non-tumorous diseases are agreeable with the determinative effect defined by ICRP. Other literatures have shown that effects of Pu inhalation differ dependently on the solubility of its chemical form and on its isotope ( 239 Pu and 238 Pu). Size of the inhaled Pu particle affects its deposition and thereby its influence on the air tract and other tissues. Rats are also used in Pu inhalation experiments. The significant increase of malignant lung tumor incidence is shown with 239 PuO 2 inhalation at >1 Gy lung absorbed dose by PNL and Inhalation Toxicology Research Institute (ITRI) and by National Institute of Radiological Sciences (NIRS), at >0.7 Gy and not at 239 PuO 2 inhalation in dogs involves the long-term decrease of peripheral lymphocytes, acute radiation pneumonia and chronic fibroid lung at 10-20 Gy, which can be a cause of death. There are many studies of the lung tumor formation at various carcinogenic steps in rats. Problems to be solved for the inhaled Pu compound are the elucidation of accuracy and validity concerning the metabolic parameters, alpha-ray dose assessment, dose rate effects of particle size; the biological factors modifying the metabolism and effect; and the relationship of cancer formation with non-tumorous diseases. (T.T)

  13. Cell biology experiments conducted in space

    Science.gov (United States)

    Taylor, G. R.

    1977-01-01

    A review of cell biology experiments conducted during the first two decades of space flight is provided. References are tabulated for work done with six types of living test system: isolated viruses, bacteriophage-host, bacteria, yeasts and filamentous fungi, protozoans, and small groups of cells (such as hamster cell tissue and fertilized frog eggs). The general results of studies involving the survival of cells in space, the effect of space flight on growing cultures, the biological effects of multicharged high-energy particles, and the effects of space flight on the genetic apparatus of microorganisms are summarized. It is concluded that cell systems remain sufficiently stable during space flight to permit experimentation with models requiring a fixed cell line during the space shuttle era.

  14. Studies on the effects of cosmic HZE-particles on different biological systems in the Biostack experiments I and II flown on board of Apollo 16 and 17

    International Nuclear Information System (INIS)

    Bucker, H.; Horneck, G.

    1975-01-01

    The Biostack experiments are described and the effects of cosmic HZE-particles on different biological systems are discussed. The biological systems contained in the experimental packages include spores of Bacillus subtilis, cysts of Colpoda cucullus, seeds of Arabidopsis thaliana, radiculae of Vicia faba, and eggs of Artemia solina, Tribolium castaneum, and Carausius moresus. The physical characteristics of the particles are given and the implications for manned spaceflight are discussed

  15. Biological radiation effects

    International Nuclear Information System (INIS)

    Kiefer, J.

    1989-01-01

    The book covers all aspects of biological radiation effects. The physical basis is dealt with in some detail, and the effects at the subcellular and the cellular level are discussed, taking into account modern developments and techniques. The effects on the human organism are reviewed, both from the point of view of applications in medicine as well as with regard to radiation hazards (teratogenic, gonadal and carcinogenic effects)

  16. Biological Effects of Radiation

    International Nuclear Information System (INIS)

    Jatau, B.D.; Garba, N.N.; Yusuf, A.M.; Yamusa, Y. A.; Musa, Y.

    2013-01-01

    In earlier studies, researchers aimed a single particle at the nucleus of the cell where DNA is located. Eighty percent of the cells shot through the nucleus survived. This contradicts the belief that if radiation slams through the nucleus, the cell will die. But the bad news is that the surviving cells contained mutations. Cells have a great capacity to repair DNA, but they cannot do it perfectly. The damage left behind in these studies from a single particle of alpha radiation doubled the damage that is already there. This proved, beyond a shadow of doubt, those there biological effects occur as a result of exposure to radiation, Radiation is harmful to living tissue because of its ionizing power in matter. This ionization can damage living cells directly, by breaking the chemical bonds of important biological molecules (particularly DNA), or indirectly, by creating chemical radicals from water molecules in the cells, which can then attack the biological molecules chemically. At some extent these molecules are repaired by natural biological processes, however, the effectiveness of this repair depends on the extent of the damage. The interaction of ionizing with the human body, arising either from external sources outside the body or from internal contamination of the body by radioactive materials, leads to the biological effects which may later show up as a clinical symptoms. Basically, this formed the baseline of this research to serve as a yardstick for creating awareness about radiation and its resulting effects.

  17. Biological effects of hyperthermia

    International Nuclear Information System (INIS)

    Okumura, Hiroshi

    1980-01-01

    Biological effects of hyperthermia and application of hyperthermia to cancer therapy were outlined. As to independent effects of hyperthermia, heat sensitivity of cancer cells, targets of hyperthermia, thermal tolerance of cancer cells, effects of pH on hyperthermic cell survival, effects of hyperthermia on normal tissues, and possibility of clinical application of hyperthermia were described. Combined effect of hyperthermia and x-irradiation to enhance radiosensitivity of cancer cells, its mechanism, effects of oxygen on cancer cells treated with hyperthermia and irradiation, and therapeutic ratio of combined hyperthermia and irradiation were also described. Finally, sensitizers were mentioned. (Tsunoda, M.)

  18. Biological Effects of Ionizing Radiation

    Science.gov (United States)

    Ingram, M.; Mason, W. B.; Whipple, G. H.; Howland, J. W.

    1952-04-07

    This report presents a review of present knowledge and concepts of the biological effects of ionizing radiations. Among the topics discussed are the physical and chemical effects of ionizing radiation on biological systems, morphological and physiological changes observed in biological systems subjected to ionizing radiations, physiological changes in the intact animal, latent changes following exposure of biological systems to ionizing radiations, factors influencing the biological response to ionizing radiation, relative effects of various ionizing radiations, and biological dosimetry.

  19. Tritium biological effects and perspective of the biological study

    International Nuclear Information System (INIS)

    Komatsu, Kenshi

    1998-01-01

    Since tritium is an emitter of weak β-rays (5.7keV) and is able to bind to DNA, i.e., the most important genome component, the biological effects should be expected to be more profound than that of X-rays and γ-rays. When carcinogenesis, genetical effects and the detriments for fetus and embryo were used as a biological endpoint, most of tritium RBE (relative biological effectiveness) ranged from 1 to 2. The tritium risk in man could be calculated from these RBEs and γ-ray risk for human exposure, which are obtained mainly from the data on Atomic Bomb survivors. However, the exposure modality from environmental tritium should be a chronic irradiation with ultra low dose rate or a fractionated irradiation. We must estimate the tritium effect in man based on biological experiments alone, due to lack of such epidemiological data. Low dose rate experiment should be always accompanied by the statistical problem of data, since their biological effects are fairy low, and they should involve a possible repair system, such as adaptive response (or hormesis effect) and 'Kada effect' observed in bacteria. Here we discuss future works for the tritium assessment in man, such as (1) developing a high radiation sensitive assay system with rodent hybrid cells containing a single human chromosome and also (2) study on mammal DNA repair at molecular levels using a radiosensitive hereditary disease, Nijmegen Breakage Syndrome. (author)

  20. [Experience of the development special medical technical laboratory for studies of effects caused by potent electromagnetic radiation in biologic objects].

    Science.gov (United States)

    Gorodetsky, B N; Kalyada, T V; Petrov, S V

    2015-01-01

    This article covers topics of creating special medical technical laboratory for medial and biologic studies concerning influence of potent high-frequency elecromagnetic radiation on various biologic objects. The authors gave example of such laboratory, described its construction features, purpose and main characteristics of the included devices.

  1. Biological effects of tritium

    International Nuclear Information System (INIS)

    Nieto, M.

    1985-01-01

    The aim of this project is to study the thermal effects on proliferation activity in the intestinal epithelium of the goldfish acclimated at different temperatures (stationary state). The cell division occurs only at certain phases of the circadian cycle when the proliferative activity is synchronized or trained by an environmental factor such as light-dark cycle. Another aspect of the project is the study of the biological effects, non-stochastic, on cell kinetics in animals chronically exposed to low dose rates or tritium and gamma rays from 60 CO, used as a standard radiation. The influence on the accumulated dose per cell and cycle cell in function of the duration of the cell cycle at different acclimation temperatures should be considered. To calculate the risk of tritium contamination from nuclear power plants (radiation exposure), the organic tissue-bond is of decisive importance due to the long turnover of the organic tissue-bond in organisms favouring transport of tritium to other organisms of the ecosystem and to man. (author)

  2. Bodily experiences in secondary school biology

    Science.gov (United States)

    Orlander, Auli Arvola; Wickman, Per-Olof

    2011-09-01

    This is a study of teaching about the human body. It is based on transcribed material from interviews with 15-year-old students and teachers about their experiences of sex education and from recordings of classroom interactions during a dissection. The analysis is focused on the relationship between what students are supposed to learn about the biological body and their expressed experiences and meaning making of bodies in the schoolwork. The results indicate that the negotiations associated with the encounters between the bodies of the classroom (student, teacher, and animal bodies) are important for what directions meaning making takes and what students are afforded to learn about bodies, biologically as well as in terms of values. We suggest that these negotiations should be taken into account at schools, be regarded as an important part of the learning processes in science education and in that way open up for new possibilities for students' meaning making.

  3. Biological radiation effects

    International Nuclear Information System (INIS)

    Sejourne, Michele.

    1977-01-01

    This work examines ionizing radiations: what they are, where they come from, their actions and consequences, finally the norms and preventive measures necessary to avoid serious contamination, whether the individual or the population in general is involved. Man has always been exposed to natural irradiation, but owing to the growing use of ionizing radiations both in medicine and in industry, not to mention nuclear tests and their use as an argument of dissuasion, the irradiation of human beings is increasing daily. Radioactive contamination does remain latent, apart from acute cases, but this is where the danger lies since the consequences may not appear until long after the irradiation. Of all biological effects due to the action of radioelements the genetic risk is one of the most important, affecting the entire population and especially the generations to come. The risk of cancer and leukemia induction plays a substantial part also since a large number of people may be concerned, depending on the mode of contamination involved. All these long-term dangers do not of course exclude the various general or local effects to which the individual alone may be exposed and which sometimes constitute a threat to life. As a result the use of ionizing radiations must be limited and should only be involved if no other process can serve instead. The regulations governing radioelements must be stringent and their application strictly supervised for the better protection of man. This protection must be not only individual but also collective since pollution exists in air, water and land passes to plants and animals and finally reaches the last link in the food chain, man [fr

  4. Biological effects of electromagnetic fields

    International Nuclear Information System (INIS)

    Gabriel, C.

    1996-01-01

    The effects of electromagnetic (em) fields on biological systems were first observed and exploited well over a century ago. Concern over the possible health hazards of human exposure to such fields developed much later. It is now well known that excessive exposure to em fields may have in undesirable biological consequences. Standards were introduced to determine what constitute an excessive exposure and how to avoid it. Current concern over the issue of hazards stems mainly from recent epidemiological studies of exposed populations and also from the results of laboratory experiments in which whole animals are exposed in vivo or tissue and cell cultures exposed in vitro to low levels of irradiation. The underlying fear is the possibility of a causal relationship between chronic exposure to low field levels and some forms of cancer. So far the evidence does not add up to a firm statement on the matter. At present it is not known how and at what level, if at all, can these exposure be harmful to human health. This state of affair does not provide a basis for incorporating the outcome of such research in exposure standards. This paper will give a brief overview of the research in this field and how it is evaluated for the purpose of producing scientifically based standards. The emphasis will be on the physical, biophysical and biological mechanisms implicated in the interaction between em fields and biological systems. Understanding such mechanisms leads not only to a more accurate evaluation of their health implications but also to their optimal utilization, under controlled conditions, in biomedical applications. (author)

  5. Low-dose neutron dose response of zebrafish embryos obtained from the Neutron exposure Accelerator System for Biological Effect Experiments (NASBEE) facility

    International Nuclear Information System (INIS)

    Ng, C.Y.P.; Kong, E.Y.; Konishi, T.; Kobayashi, A.; Suya, N.; Cheng, S.H.; Yu, K.N.

    2015-01-01

    The dose response of embryos of the zebrafish, Danio rerio, irradiated at 5 h post fertilization (hpf) by 2-MeV neutrons with ≤100 mGy was determined. The neutron irradiations were made at the Neutron exposure Accelerator System for Biological Effect Experiments (NASBEE) facility in the National Institute of Radiological Sciences (NIRS), Chiba, Japan. A total of 10 neutron doses ranging from 0.6 to 100 mGy were employed (with a gamma-ray contribution of 14% to the total dose), and the biological effects were studied through quantification of apoptosis at 25 hpf. The responses for neutron doses of 10, 20, 25, and 50 mGy approximately fitted on a straight line, while those for neutron doses of 0.6, 1 and 2.5 mGy exhibited neutron hormetic effects. As such, hormetic responses were generically developed by different kinds of ionizing radiations with different linear energy transfer (LET) values. The responses for neutron doses of 70 and 100 mGy were significantly below the lower 95% confidence band of the best-fit line, which strongly suggested the presence of gamma-ray hormesis. - Highlights: • Neutron dose response was determined for embryos of the zebrafish, Danio rerio. • Neutron doses of 0.6, 1 and 2.5 mGy led to neutron hormetic effects. • Neutron doses of 70 and 100 mGy accompanied by gamma rays led to gamma-ray hormesis

  6. Biological radiation effects

    International Nuclear Information System (INIS)

    Koggl, D.; Dedenkov, A.N.

    1986-01-01

    All nowadays problems of radio biology are considered: types of ionizing radiations, their interaction with material; damage of molecular structures and their reparation; reaction of cells and their recovery from radiation damage; reaction of the whole organism and its separate systems. Particular attention is given to the problems of radiation carcinogenesis and radiation hazard for man

  7. Quantum Effects in Biological Systems

    CERN Document Server

    2016-01-01

    Since the last decade the study of quantum mechanical phenomena in biological systems has become a vibrant field of research. Initially sparked by evidence of quantum effects in energy transport that is instrumental for photosynthesis, quantum biology asks the question of how methods and models from quantum theory can help us to understand fundamental mechanisms in living organisms. This approach entails a paradigm change challenging the related disciplines: The successful framework of quantum theory is taken out of its low-temperature, microscopic regimes and applied to hot and dense macroscopic environments, thereby extending the toolbox of biology and biochemistry at the same time. The Quantum Effects in Biological Systems conference is a platform for researchers from biology, chemistry and physics to present and discuss the latest developments in the field of quantum biology. After meetings in Lisbon (2009), Harvard (2010), Ulm (2011), Berkeley (2012), Vienna (2013), Singapore (2014) and Florence (2015),...

  8. Biology of ionizing radiation effects

    International Nuclear Information System (INIS)

    Ferradini, C.; Pucheault, J.

    1983-01-01

    The present trends in biology of ionizing radiation are reviewed. The following topics are investigated: interaction of ionizing radiations with matter; the radiolysis of water and aqueous solutions; properties of the free radicals intervening in the couples O 2 /H 2 O and H 2 O/H 2 ; radiation chemistry of biological compounds; biological effects of ionizing radiations; biochemical mechanisms involving free radicals as intermediates; applications (biotechnological applications, origins of life) [fr

  9. Biological radiation effects

    International Nuclear Information System (INIS)

    Gomes, R.A.

    1976-01-01

    The stages of processes leading to radiation damage are studied, as well as, the direct and indirect mechanics of its production. The radiation effects on nucleic acid and protein macro moleculas are treated. The physical and chemical factors that modify radiosensibility are analysed, in particular the oxygen effects, the sensibilization by analogues of nitrogen bases, post-effects, chemical protection and inherent cell factors. Consideration is given to restoration processes by excision of injured fragments, the bloching of the excision restoration processes, the restoration of lesions caused by ionizing radiations and to the restoration by genetic recombination. Referring to somatic effects of radiation, the early ones and the acute syndrome of radiation are discussed. The difference of radiosensibility observed in mammalian cells and main observable alterations in tissues and organs are commented. Referring to delayed radiation effects, carcinogeneses, alterations of life span, effects on growth and development, as well as localized effects, are also discussed [pt

  10. Biological effects of particle radiation

    International Nuclear Information System (INIS)

    Sakamoto, Kiyohiko

    1988-01-01

    Conventional radiations such as photons, gamma rays or electrons show several physical or biological disadvantages to bring tumors to cure, therefore, more and more attentions is being paid to new modalitie such as fast neutrons, protons, negative pions and heavy ions, which are expected to overcome some of the defects of the conventional radiations. Except for fast neutrons, these particle radiations show excellet physical dose localization in tissue, moreover, in terms of biological effects, they demonstrate several features compared to conventional radiations, namely low oxygen enhancement ratio, high value of relative biological effectiveness, smaller cellular recovery, larger therapeutic gain factor and less cell cycle dependency in radiation sensitivity. In present paper the biological effects of particle radiations are shown comparing to the effects of conventional radiations. (author)

  11. The Effects of Autonomy-Supportive and Controlling Teaching Behaviour in Biology Lessons with Primary and Secondary Experiences on Students' Intrinsic Motivation and Flow-Experience

    Science.gov (United States)

    Hofferber, Natalia; Basten, Melanie; Großmann, Nadine; Wilde, Matthias

    2016-01-01

    Self-Determination Theory and Flow Theory propose that perceived autonomy fosters the positive qualities of motivation and flow-experience. Autonomy-support can help to maintain students' motivation in very interesting learning activities and may lead to an increase in the positive qualities of motivation in less interesting learning activities.…

  12. Biological and Medical Experiments on the Space Shuttle, 1981 - 1985

    Science.gov (United States)

    Halstead, Thora W. (Editor); Dufour, Patricia A. (Editor)

    1986-01-01

    This volume is the first in a planned series of reports intended to provide a comprehensive record of all the biological and medical experiments and samples flown on the Space Shuttle. Experiments described have been conducted over a five-year period, beginning with the first plant studies conducted on STS-2 in November 1981, and extending through STS 61-C, the last mission to fly before the tragic Challenger accident of January 1986. Experiments were sponsored within NASA not only by the Life Sciences Division of the Office of Space Science and Applications, but also by the Shuttle Student Involvement Program (SSIP) and the Get Away Special (GAS) Program. Independent medical studies were conducted as well on the Shuttle crew under the auspices of the Space Biomedical Research Institute at Johnson Space Center. In addition, cooperative agreements between NASA and foreign government agencies led to a number of independent experiments and also paved the way for the joint US/ESA Spacelab 1 mission and the German (DFVLR) Spacelab D-1. Experiments included: (1) medically oriented studies of the crew aimed at identifying, preventing, or treating health problems due to space travel; (2) projects to study morphological, physiological, or behavioral effects of microgravity on animals and plants; (3) studies of the effects of microgravity on cells and tissues; and (4) radiation experiments monitoring the spacecraft environment with chemical or biological dosimeters or testing radiation effects on simple organisms and seeds.

  13. In vitro biological effectiveness of JRR-4 epithermal neutron beam. Experiment under free air beam and in water phantom. Cooperative research

    International Nuclear Information System (INIS)

    Yamamoto, Tetsuya; Matsumura, Akira; Nose, Tadao; Yamamoto, Kazuyoshi; Kumada, Hiroaki; Kishi, Toshiaki; Hori, Naohiko; Torii, Yoshiya; Horiguchi, Yoji

    2002-05-01

    The surviving curve and the biological effectiveness factor of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at Japan Research Reactor No.4. Surviving fraction of V79 Chinese hamster cell with or without 10 B was obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal neutron beam (TNB-2), which were used or planned to use for BNCT clinical trial. The cell killing effect of these neutron beams with or without the presence of 10 B depended highly on the neutron beam used, according to the epithermal and fast neutron content in the beam. The biological effectiveness factor values of the boron capture reaction for ENB, TNB-1 and TNB-2 were 3.99±0.24, 3.04±0.19 and 1.43±0.08, respectively. The biological effectiveness factor values of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50±0.32, 2.34±0.30 and 2.17±0.28 for ENB, TNB-1 and TNB-2, respectively. The biological effectiveness factor values of the neutron and photon components were 1.22±0.16, 1.23±0.16 and 1.21±0.16, respectively. The depth function of biological effectiveness factor in water phantom and the difference in biological effectiveness factor among boron compounds were also determined. The experimental determination of biological effectiveness factor outlined in this paper is applicable to the dose calculation for each dose component of the neutron beams and contribute to an accurate biological effectiveness factor as comparison with a neutron beam at a different facility employed in ongoing and planned BNCT clinical trials. (author)

  14. Biological effects of radium

    International Nuclear Information System (INIS)

    Drosselmeyer, E.

    1982-12-01

    It is evident from a survey of the current literature that a problem exists in finding the correlation between the exposure of the human body to radiation, with the subsequent development of diseases, particularly for certain types of cancer. A brief history of the early experiences of radium incorporation into humans is given followed by data collected on some important polulation groups exposed to radium body burden, such as miners in rare metal and uranium mines, dial painters and some groups of patients. The medical and technical applications of radium are discussed. A summary is also given of the natural occurence of radium and the amounts in which it is present in the environment. Incorporation, retention and excretion pathways are outlined. In order to study the metabolism and the induction of diseases by radium several animal studies have been performed. The ICRP regards radium-226 as the best known and most studied radionuclide. It can thus serve as a guideline for setting limits for other radionuclides, e.g. plutonium. The valid limiting value for radium-226 of 0.1 μCi for whole body exposure is generally accepted and regarded as sufficiently safe. Finally, transfer factors have been collected as fas as they were available in the literature. (orig./MG) [de

  15. BIOLOGIC AND ECONOMIC EFFECTS OF INCLUDING DIFFERENT ...

    African Journals Online (AJOL)

    The biologic and economic effects of including three agro-industrial by-products as ingredients in turkey poult diets were investigated using 48 turkey poults in a completely randomised design experiment. Diets were formulated to contain the three by-products – wheat offal, rice husk and palm kernel meal, each at 20% level ...

  16. Biological radiation effects

    International Nuclear Information System (INIS)

    Russo, A.

    2000-01-01

    Everyone is exposed to a complex mix of electromagnetic fields (EMF) of different frequencies that permeate our environment. Exposures to these EMF are increasing significantly as technology advances unabated and new applications are found. Technological progress in the broadest sense of the word has always been associated with various hazards and risks, both perceived and real. The industrial, commercial and household application on EMF is no exception. Throughout the world, the general public is concerned that exposure to EMF from such sources as high voltage power lines, broadcasting networks, mobile telephones and their base stations could lead to adverse health consequences, especially in children. As a result, the construction of new power lines and broadcasting and mobile telephone network has met with considerable opposition in many countries. Public exposure to EMF is regulated by a variety of voluntary and legal limits, together with various national safety standards. Guidelines are designed to avoid all identified hazards, from short and long term exposure, recommended limits. The aim of this paper is to report the summary of the actual scientific knowledge about the potential health effects and hazards due to man made EMF and the new tendencies of the social and political choices [it

  17. Biological effects of nuclear weapons

    International Nuclear Information System (INIS)

    Frischauf, H.

    1983-01-01

    Prompt and delayed biological effects of nuclear weapons are discussed. The response to excess pressure on man is estimated, the acute radiation syndrome caused by different radiation doses and cancerogenous and genetic effects are described. Medical care after a nuclear explosion would be difficult and imperfect. (M.J.)

  18. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Heribanova, A.

    1995-01-01

    The basic principles and pathways of effects of ionizing radiation on living organisms and cells are outlined. The following topics are covered: effects of radiation on living matter (direct effects, radical or indirect effects, dual radiation action, and molecular biological theories); effects of radiation on cells and tissues (cell depletion, changes in the cytogenetic information, reparation mechanisms), dose-response relationship (deterministic effects, stochastic effects), and the effects of radiation on man (acute radiation sickness, acute local changes, fetus injuries, non-tumorous late injuries, malignant tumors, genetic changes). (P.A.). 3 tabs., 2 figs., 5 refs

  19. Biological effects of electromagnetic fields

    International Nuclear Information System (INIS)

    David, E.

    1993-01-01

    In this generally intelligible article, the author describes at first the physical fundamentals of electromagnetic fields and their basic biological significance and effects for animals and human beings before dealing with the discussion regarding limiting values and dangers. The article treats possible connections with leukaemia as well as ith melatonine production more detailed. (vhe) [de

  20. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Marko, A.M.

    1981-05-01

    In this review radiation produced by the nuclear industry is placed into context with other sources of radiation in our world. Human health effects of radiation, derivation of standards and risk estimates are reviewed in this document. The implications of exposing the worker and the general population to radiation generated by nuclear power are assessed. Effects of radiation are also reviewed. Finally, gaps in our knowledge concerning radiation are identified and current research on biological effects, on environmental aspects, and on dosimetry of radiation within AECL and Canada is documented in this report. (author)

  1. Estimation of Biological Effects of Tritium.

    Science.gov (United States)

    Umata, Toshiyuki

    2017-01-01

    Nuclear fusion technology is expected to create new energy in the future. However, nuclear fusion requires a large amount of tritium as a fuel, leading to concern about the exposure of radiation workers to tritium beta radiation. Furthermore, countermeasures for tritium-polluted water produced in decommissioning of the reactor at Fukushima Daiichi Nuclear Power Station may potentially cause health problems in radiation workers. Although, internal exposure to tritium at a low dose/low dose rate can be assumed, biological effect of tritium exposure is not negligible, because tritiated water (HTO) intake to the body via the mouth/inhalation/skin would lead to homogeneous distribution throughout the whole body. Furthermore, organically-bound tritium (OBT) stays in the body as parts of the molecules that comprise living organisms resulting in long-term exposure, and the chemical form of tritium should be considered. To evaluate the biological effect of tritium, the effect should be compared with that of other radiation types. Many studies have examined the relative biological effectiveness (RBE) of tritium. Hence, we report the RBE, which was obtained with radiation carcinogenesis classified as a stochastic effect, and serves as a reference for cancer risk. We also introduce the outline of the tritium experiment and the principle of a recently developed animal experimental system using transgenic mouse to detect the biological influence of radiation exposure at a low dose/low dose rate.

  2. MOTHERHOOD EXPERIENCE: ADOPTIVE AND BIOLOGICAL MOTHERS

    Directory of Open Access Journals (Sweden)

    Yulia F. Lakhvich

    2014-12-01

    Full Text Available To become a mother … To be a mother … What does it mean for a woman? And what else changes her life so irreversibly, allows to see the world in a different way and discovers new, earlier unknown features? Probably, nothing does. However, there is also a question how a woman bearing a child and carrying out motherhood responsibilities and a woman who has not given life to a child, but carrying out the same responsibilities, goes through the process of motherhood. It is one of the questions that was studied in a comparative research of the adaptation process in the Belarusian adoptive and biological families in case of a child appearing in the family. The study involved 64 adoptive and 62 biological mothers.

  3. Rotating biological contactors: the Canadian experience

    Energy Technology Data Exchange (ETDEWEB)

    Cuenca, Manuel A. [Ryerson Polytechnical Univ., Toronto, ON (Canada). Chemical Engineering Dept.; Smith, Tom [CMS Rotordisk Inc., Concord, ON (Canada); Vianna, Arlinda C. [Servico Nacional de Aprendizagem Industrial (SENAI), Salvador, BA (Brazil)

    1993-12-31

    In fifteen years, Rotating Biological Contactors (RBC) have become one of the most attractive technologies for secondary wastewater treatment. The present work is a review of the evolution of RBC technology in the last twenty years. In addition, the status of the technology in Canada is described, emphasizing industrial facilities and landfill leachate treatment. An enumeration of the most relevant development areas is included. (author). 34 refs., 3 figs., 7 tabs.

  4. Rotating biological contactors: the Canadian experience

    Energy Technology Data Exchange (ETDEWEB)

    Cuenca, Manuel A [Ryerson Polytechnical Univ., Toronto, ON (Canada). Chemical Engineering Dept.; Smith, Tom [CMS Rotordisk Inc., Concord, ON (Canada); Vianna, Arlinda C [Servico Nacional de Aprendizagem Industrial (SENAI), Salvador, BA (Brazil)

    1994-12-31

    In fifteen years, Rotating Biological Contactors (RBC) have become one of the most attractive technologies for secondary wastewater treatment. The present work is a review of the evolution of RBC technology in the last twenty years. In addition, the status of the technology in Canada is described, emphasizing industrial facilities and landfill leachate treatment. An enumeration of the most relevant development areas is included. (author). 34 refs., 3 figs., 7 tabs.

  5. The biological effects of radiation

    International Nuclear Information System (INIS)

    Sykes, D.A.

    1979-01-01

    The hazards of radiations to man are briefly covered in this paper. The natural background sources of radiations are stated and their resulting doses are compared to those received voluntarily by man. The basis of how radiations cause biological damage is given and the resulting somatic effects are shown for varying magnitude of dose. Risk estimates are given for cancer induction and genetic effects are briefly discussed. Finally four case studies of radiation damage to humans are examined exemplifying the symptoms of large doses of radiations [af

  6. Morphogenesis and pattern formation in biological systems experiments and models

    CERN Document Server

    Noji, Sumihare; Ueno, Naoto; Maini, Philip

    2003-01-01

    A central goal of current biology is to decode the mechanisms that underlie the processes of morphogenesis and pattern formation. Concerned with the analysis of those phenomena, this book covers a broad range of research fields, including developmental biology, molecular biology, plant morphogenesis, ecology, epidemiology, medicine, paleontology, evolutionary biology, mathematical biology, and computational biology. In Morphogenesis and Pattern Formation in Biological Systems: Experiments and Models, experimental and theoretical aspects of biology are integrated for the construction and investigation of models of complex processes. This collection of articles on the latest advances by leading researchers not only brings together work from a wide spectrum of disciplines, but also provides a stepping-stone to the creation of new areas of discovery.

  7. In vitro biological effectiveness of JRR-4 epithermal neutron beam. Experiment under free air beam and in water phantom. Cooperative research

    CERN Document Server

    Yamamoto, T; Horiguchi, Y; Kishi, T; Kumada, H; Matsumura, A; Nose, T; Torii, Y; Yamamoto, K

    2002-01-01

    The surviving curve and the biological effectiveness factor of dose components generated in boron neutron capture therapy (BNCT) were separately determined in neutron beams at Japan Research Reactor No.4. Surviving fraction of V79 Chinese hamster cell with or without sup 1 sup 0 B was obtained using an epithermal neutron beam (ENB), a mixed thermal-epithermal neutron beam (TNB-1), and a thermal neutron beam (TNB-2), which were used or planned to use for BNCT clinical trial. The cell killing effect of these neutron beams with or without the presence of sup 1 sup 0 B depended highly on the neutron beam used, according to the epithermal and fast neutron content in the beam. The biological effectiveness factor values of the boron capture reaction for ENB, TNB-1 and TNB-2 were 3.99+-0.24, 3.04+-0.19 and 1.43+-0.08, respectively. The biological effectiveness factor values of the high-LET dose components based on the hydrogen recoils and the nitrogen capture reaction were 2.50+-0.32, 2.34+-0.30 and 2.17+-0.28 for EN...

  8. Statistical analysis of joint toxicity in biological growth experiments

    DEFF Research Database (Denmark)

    Spliid, Henrik; Tørslev, J.

    1994-01-01

    The authors formulate a model for the analysis of designed biological growth experiments where a mixture of toxicants is applied to biological target organisms. The purpose of such experiments is to assess the toxicity of the mixture in comparison with the toxicity observed when the toxicants are...... is applied on data from an experiment where inhibition of the growth of the bacteria Pseudomonas fluorescens caused by different mixtures of pentachlorophenol and aniline was studied.......The authors formulate a model for the analysis of designed biological growth experiments where a mixture of toxicants is applied to biological target organisms. The purpose of such experiments is to assess the toxicity of the mixture in comparison with the toxicity observed when the toxicants...

  9. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    Experiments with small animals, tissue cultures, and inanimate materials help with understanding the effects of ionizing radiation that occur at the molecular level and cause the gross effects observed in man. Topics covered in this chapter include the following: Radiolysis of Water; Radiolysis of Organic Compounds; Radiolysis in Cells; Radiation Exposure and Dose Units; Dose Response Curves; Radiation Effects in Animals; Factors Affecting Health Risks. 8 refs., 3 figs., 5 tabs

  10. Biological effects of heavy particles

    International Nuclear Information System (INIS)

    Sabatier, L.; Martins, B.; Dutrillaux, B.

    1991-01-01

    The usual definitions of biological dose and biological dosimetry do not fit in case of particles with high linear energy transfer (LET). The dose corresponds to an average value which is not representative of the highly localized energy transfer due to heavy ions. Fortunately, up to now, a biological dosimetry following an exposure to high LET particles is necessary only for cosmonauts. In radiotherapy applications, one exactly knows the nature and energy of incident particle beams. The quality requirements for a good biodosimeter include reliable relation between dose and effect, weak sensitivity to individual variations, reliability and stability of acquired informations against the time delay between exposure and measurements. Nothing is better than the human lymphocyte to be used for measurements that fulfil these requirements. In the case of a manned spaceship, the irradiation dose corresponds to a wide range of radiation (protons, neutrons, heavy ions), and making a dosimetry as well as defining it are of current concern. As yet, there exist two possible definitions, which reduce the dose either to a proton or to a neutron equivalent one. However, such an approximation is not a faithful representation of the irradiation effects and in particular, the long-term effects may be quite different. In the future, it is reasonable to expect an evolution towards technics that enable identifying irradiated cells and quantifying precisely their radiation damage in order to reconstruct the spectrum of particles received by a given cosmonaut in a given time. Let us emphasize that the radiation hazards due to a short stay in space are quite minor, but in the case of a travel to Mars, they cannot be neglected [fr

  11. Physical basis for biological effect

    International Nuclear Information System (INIS)

    Goodhead, D.T.

    1987-01-01

    Absorbed dose, or particle fluence, alone, are poor predictors of the biological effectiveness of ionizing radiations. Various radiation 'quality' parameters have been proposed to account quantitatively for the differences due to type of radiation. These include LET, quality factor (Q), lineal energy, specific energy and Z 2 /β 2 . However, all of these have major shortcomings, largely because they fail to describe adequately the microscopic stochastic properties of radiation which are primarily responsible for their relative effectiveness. Most biophysical models of radiation action now agree that the biological effectiveness of radiations are to a large extent determined by their very localized spatial properties of energy deposition (perhaps DNA and associated structures) and that the probability of residual permanent cellular damage (after cellular repair) depends on the nature of this initial macromolecular damage. Common features of these models make it clear that major future advances in identifying critical physical parameters of radiations for general practical application, or to describe their fundamental mechanisms of action, require accurate knowledge of the spatial patterns of energy deposition down to distances of the order of nanometres. Therefore, adequate descriptions are required of the nature and spatial distribution of the initial charged particles and of the interaction-by-interaction structure of the ensuing charged particle tracks. Recent development and application of Monte Carlo track structure simulations have already made it possible to commence such analyses of radiobiological data. (author). 56 refs, 7 figs

  12. Low level radiation: biological effects

    International Nuclear Information System (INIS)

    Loken, M.K.

    1983-01-01

    It is imperative that physicians and scientists using radiations in health care delivery continue to assess the benefits derived, vs. potential risk, to patients and radiation workers being exposed to radiation in its various forms as part of our health delivery system. Insofar as possible we should assure our patients and ourselves that the benefits outweigh the potential hazards involved. Inferences as to the possible biological effects of low level radiation are generally based on extrapolations from those effects observed and measured following acute exposures to considerably higher doses of radiation. Thus, in order to shed light on the question of the possible biological effects of low level radiation, a wide variety of studies have been carried out using cells in culture and various species of plant and animal life. This manuscript makes reference to some of those studies with indications as to how and why the studies were done and the conclusions that might be drawn there from. In addition reference is made to the handling of this information by scientists, by environmentalists, and by the news media. Unfortunately, in many instances the public has been misled by what has been said and/or written. It is hoped that this presentation will provide an understandable and reasonable perspective on the various appropriate uses of radiation in our lives and how such uses do provide significant improvement in our health and in our quality of life

  13. Conjugate Meningococcal Vaccines Development: GSK Biologicals Experience

    Science.gov (United States)

    Miller, Jacqueline M.; Mesaros, Narcisa; Van Der Wielen, Marie; Baine, Yaela

    2011-01-01

    Meningococcal diseases are serious threats to global health, and new vaccines specifically tailored to meet the age-related needs of various geographical areas are required. This paper focuses on the meningococcal conjugate vaccines developed by GSK Biologicals. Two combined conjugate vaccines were developed to help protect infants and young children in countries where the incidence of meningococcal serogroup C or serogroup C and Y disease is important: Hib-MenC-TT vaccine, which offers protection against Haemophilus influenzae type b and Neisseria meningitidis serogroup C diseases, is approved in several countries; and Hib-MenCY-TT vaccine, which adds N. meningitidis serogroup Y antigen, is currently in the final stages of development. Additionally, a tetravalent conjugate vaccine (MenACWY-TT) designed to help protect against four meningococcal serogroups is presently being evaluated for global use in all age groups. All of these vaccines were shown to be highly immunogenic and to have clinically acceptable safety profiles. PMID:21991444

  14. Conjugate Meningococcal Vaccines Development: GSK Biologicals Experience

    Directory of Open Access Journals (Sweden)

    Jacqueline M. Miller

    2011-01-01

    Full Text Available Meningococcal diseases are serious threats to global health, and new vaccines specifically tailored to meet the age-related needs of various geographical areas are required. This paper focuses on the meningococcal conjugate vaccines developed by GSK Biologicals. Two combined conjugate vaccines were developed to help protect infants and young children in countries where the incidence of meningococcal serogroup C or serogroup C and Y disease is important: Hib-MenC-TT vaccine, which offers protection against Haemophilus influenzae type b and Neisseria meningitidis serogroup C diseases, is approved in several countries; and Hib-MenCY-TT vaccine, which adds N. meningitidis serogroup Y antigen, is currently in the final stages of development. Additionally, a tetravalent conjugate vaccine (MenACWY-TT designed to help protect against four meningococcal serogroups is presently being evaluated for global use in all age groups. All of these vaccines were shown to be highly immunogenic and to have clinically acceptable safety profiles.

  15. Infusing Outdoor Field Experiences into the Secondary Biology Curriculum.

    Science.gov (United States)

    Owens, Ginny

    1984-01-01

    To offer students biological field experiences, teachers should use their own basic skills, be enthusiastic motivators, participate in community programs/courses/workshops to acquire additional skills/knowledge for outdoor biological education, plan outdoor excursions with safety considerations in mind, and use available resources for classroom…

  16. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Gisone, Pablo; Perez, Maria R.

    2001-01-01

    It has been emphasised the importance of DNA as the main target for ionizing radiation, that can induce damage by its direct action on this molecule or by an indirect effect mediated by free-radicals generated by water radiolysis. Biological effects of ionizing radiation are influenced not only by the dose but also by the dose-rate and the radiation quality. Radiation induced damage, mainly DNA single and double strand breaks, is detected by molecular sensors which in turn trigger signalling cascades leading to cell cycle arrest to allow DNA repair or programmed cell death (apoptosis). Those effects related with cell death, named deterministic, exhibits a dose-threshold below which they are not observed. Acute radiation syndrome and radiological burns are examples of this kind of effects. Other radiation induced effects, called stochastic, are the consequence of cell transformation and do not exhibit a dose-threshold. This is the case of cancer induction and hereditary effects. The aim of this presentation is briefly describe the main aspects of deterministic and stochastic effects from the point of view of radiobiology and radio pathology. (author)

  17. The origins of radiotherapy: discovery of biological effects of X-rays by Freund in 1897, Kienböck's crucial experiments in 1900, and still it is the dose.

    Science.gov (United States)

    Widder, Joachim

    2014-07-01

    The discovery of X-rays by Wilhelm Conrad Röntgen (1845-1923) was triggered by pursuing an anomalous phenomenon: arousal of fluorescence at a distance from tubes in which cathode rays were elicited, a phenomenon which suggested the existence of a new kind of ray other than cathode rays. The discovery of biological effects of these X-rays by Leopold Freund (1868-1943) was triggered by pursuit of the purportedly useless phenomenon of epilation and dermatitis ensuing from X-ray-diagnostic experiments that others had reported. The crucial experiments performed by Robert Kienböck (1871-1953) entailed the proof that X-ray-dose, not electric phenomena, was the active agent of biological effects ensuing when illuminating the skin using Röntgen tubes. For both the discovery of X-rays and the discovery of their biological effectiveness, priority did not matter, but understanding the physical and medico-biological significance of phenomena that others had ignored as a nuisance. Present discussions about the clinical relevance of improving the dose distribution including protons and other charged particles resemble those around 1900 to a certain degree. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Experiences of Judeo-Christian Students in Undergraduate Biology

    Science.gov (United States)

    Barnes, M. Elizabeth; Truong, Jasmine M.; Brownell, Sara E.

    2017-01-01

    A major research thrust in science, technology, engineering, and mathematics (STEM) education is focused on how to retain students as STEM majors. The accumulation of seemingly insignificant negative experiences in STEM classes can, over time, lead STEM students to have a low sense of belonging in their disciplines, and this can lead to lower retention. In this paper, we explore how Judeo-Christian students in biology have experiences related to their religious identities that could impact their retention in biology. In 28 interviews with Judeo-Christian students taking undergraduate biology classes, students reported a religious identity that can conflict with the secular culture and content of biology. Some students felt that, because they are religious, they fall within a minority in their classes and would not be seen as credible within the biology community. Students reported adverse experiences when instructors had negative dispositions toward religion and when instructors were rigid in their instructional practices when teaching evolution. These data suggest that this may be a population susceptible to experiences of cultural conflict between their religious identities and their STEM identities, which could have implications for retention. We argue that more research should explore how Judeo-Christian students’ experiences in biology classes influence their sense of belonging and retention. PMID:28232586

  19. Reproducible computational biology experiments with SED-ML--the Simulation Experiment Description Markup Language.

    Science.gov (United States)

    Waltemath, Dagmar; Adams, Richard; Bergmann, Frank T; Hucka, Michael; Kolpakov, Fedor; Miller, Andrew K; Moraru, Ion I; Nickerson, David; Sahle, Sven; Snoep, Jacky L; Le Novère, Nicolas

    2011-12-15

    The increasing use of computational simulation experiments to inform modern biological research creates new challenges to annotate, archive, share and reproduce such experiments. The recently published Minimum Information About a Simulation Experiment (MIASE) proposes a minimal set of information that should be provided to allow the reproduction of simulation experiments among users and software tools. In this article, we present the Simulation Experiment Description Markup Language (SED-ML). SED-ML encodes in a computer-readable exchange format the information required by MIASE to enable reproduction of simulation experiments. It has been developed as a community project and it is defined in a detailed technical specification and additionally provides an XML schema. The version of SED-ML described in this publication is Level 1 Version 1. It covers the description of the most frequent type of simulation experiments in the area, namely time course simulations. SED-ML documents specify which models to use in an experiment, modifications to apply on the models before using them, which simulation procedures to run on each model, what analysis results to output, and how the results should be presented. These descriptions are independent of the underlying model implementation. SED-ML is a software-independent format for encoding the description of simulation experiments; it is not specific to particular simulation tools. Here, we demonstrate that with the growing software support for SED-ML we can effectively exchange executable simulation descriptions. With SED-ML, software can exchange simulation experiment descriptions, enabling the validation and reuse of simulation experiments in different tools. Authors of papers reporting simulation experiments can make their simulation protocols available for other scientists to reproduce the results. Because SED-ML is agnostic about exact modeling language(s) used, experiments covering models from different fields of research

  20. Reproducible computational biology experiments with SED-ML - The Simulation Experiment Description Markup Language

    Science.gov (United States)

    2011-01-01

    Background The increasing use of computational simulation experiments to inform modern biological research creates new challenges to annotate, archive, share and reproduce such experiments. The recently published Minimum Information About a Simulation Experiment (MIASE) proposes a minimal set of information that should be provided to allow the reproduction of simulation experiments among users and software tools. Results In this article, we present the Simulation Experiment Description Markup Language (SED-ML). SED-ML encodes in a computer-readable exchange format the information required by MIASE to enable reproduction of simulation experiments. It has been developed as a community project and it is defined in a detailed technical specification and additionally provides an XML schema. The version of SED-ML described in this publication is Level 1 Version 1. It covers the description of the most frequent type of simulation experiments in the area, namely time course simulations. SED-ML documents specify which models to use in an experiment, modifications to apply on the models before using them, which simulation procedures to run on each model, what analysis results to output, and how the results should be presented. These descriptions are independent of the underlying model implementation. SED-ML is a software-independent format for encoding the description of simulation experiments; it is not specific to particular simulation tools. Here, we demonstrate that with the growing software support for SED-ML we can effectively exchange executable simulation descriptions. Conclusions With SED-ML, software can exchange simulation experiment descriptions, enabling the validation and reuse of simulation experiments in different tools. Authors of papers reporting simulation experiments can make their simulation protocols available for other scientists to reproduce the results. Because SED-ML is agnostic about exact modeling language(s) used, experiments covering models from

  1. Biological effects of accelerated boron, carbon, and neon ions

    International Nuclear Information System (INIS)

    Grigoryev, Yu.G.; Ryzhov, N.I.; Popov, V.I.

    1975-01-01

    The biological effects of accelerated boron, carbon, and neon ions on various biological materials were determined. The accelerated ions included 10 B, 11 B, 12 C, 20 Ne, 22 Ne, and 40 Ar. Gamma radiation and x radiation were used as references in the experiments. Among the biological materials used were mammalian cells and tissues, yeasts, unicellular algae (chlorella), and hydrogen bacteria. The results of the investigation are given and the biophysical aspects of the problem are discussed

  2. Advancing Small Satellite Electronics Heritage for Microfluidic Biological Experiments

    Science.gov (United States)

    White, Bruce; Mazmanian, Edward; Tapio, Eric

    2016-01-01

    DLR's Eu:CROPIS (Euglena and Combined Regenerative Organic-Food Production in Space) mission, launching in 2017, will carry multiple biological payloads into a sun-synchronous orbit, including NASA Ames' PowerCell experiment. PowerCell will attempt to characterize the viability of synthetic biology at micro-g, Lunar, and Martian gravity levels. PowerCell experiment requirements demand an electronic system similar to previous microfluidic biology payloads, but with an expanded feature set. As such, the system was based on PharmaSat (Diaz-Aguado et al. 2009), a previous successful biology payload from NASA Ames, and improved upon. Newer, more miniaturized electronics allow for greater capability with a lower part count and smaller size. Two identical PowerCell enclosures will fly. Each enclosure contains two separate and identical experiments with a 48-segment optical density measurement system, grow light system, microfluidic system for nutrient delivery and waste flushing, plus thermal control and environmental sensing/housekeeping including temperature, pressure, humidity, and acceleration. Electronics consist of a single Master PCB that interfaces to the spacecraft bus and regulates power and communication, plus LED, Detector, and Valve Manifold PCBs for each experiment. To facilitate ease of reuse on future missions, experiment electronics were designed to be compatible with a standard 3U small sat form factor and power bus, or to interface with a Master power/comm PCB for use in a larger satellite as in the case of PowerCell's flight on Eu:CROPIS.

  3. The biological effectiveness of antiproton irradiation

    DEFF Research Database (Denmark)

    Holzscheiter, Michael H.; Bassler, Niels; Agazaryan, Nzhde

    2006-01-01

    ever measurements of the biological effectiveness of antiprotons. Materials and methods: V79 cells were suspended in a semi-solid matrix and irradiated with 46.7 MeV antiprotons, 48 MeV protons, or 60Co c-rays. Clonogenic survival was determined as a function of depth along the particle beams. Dose...... and particle fluence response relationships were constructed from data in the plateau and Bragg peak regions of the beams and used to assess the biological effectiveness. Results: Due to uncertainties in antiproton dosimetry we defined a new term, called the biologically effective dose ratio (BEDR), which...... has a higher relative biological effectiveness (RBE). Conclusion: We have produced the first measurements of the biological consequences of antiproton irradiation. These data substantiate theoretical predictions of the biological effects of antiproton annihilation within the Bragg peak, and suggest...

  4. Biological Effects Of Artificial Illumination

    Science.gov (United States)

    Corth, Richard

    1980-10-01

    We are increasingly being warned of the possible effects of so called "polluted" light, that is light that differs in spectral content from that of sunlight. We should be concerned, we are told, because all animals and plants have evolved under this natural daylight and therefore any difference between that illuminant and the artificial illuminants that are on the market today, is suspect. The usual presentation of the differences between the sunlight and the artificial illuminants are as shown in Figure 1. Here we are shown the spectral power distribution of sunlight and Cool White fluorescent light. The spectral power distributions of each have been normalized to some convenient wavelength so that each can be seen and easily compared on the same figure. But this presentation is misleading for one does not experience artificial illuminants at the same intensity as one experiences sunlight. Sunlight intensities are ordinarily found to be in the 8000 to 10,000 footcandle range whereas artificial illuminants are rarely experienced at intensity levels greater than 100 footcandles. Therefore a representative difference between the two types of illumination conditions is more accurately represented as in Figure 2. Thus if evolutionary adaptations require that humans and other animals be exposed to sunlight to ensure wellbeing, it is clear that one must be exposed to sunlight intensities. It is not feasible to expect that artificially illuminated environments will be lit to the same intensity as sunlight

  5. Standard reporting requirements for biological samples in metabolomics experiments: Microbial and in vitro biology experiments

    NARCIS (Netherlands)

    Werf, M.J. van der; Takors, R.; Smedsgaard, J.; Nielsen, J.; Ferenci, T.; Portais, J.C.; Wittmann, C.; Hooks, M.; Tomassini, A.; Oldiges, M.; Fostel, J.; Sauer, U.

    2007-01-01

    With the increasing use of metabolomics as a means to study a large number of different biological research questions, there is a need for a minimal set of reporting standards that allow the scientific community to evaluate, understand, repeat, compare and re-investigate metabolomics studies. Here

  6. Quantification of biologically effective environmental UV irradiance

    Science.gov (United States)

    Horneck, G.

    To determine the impact of environmental UV radiation on human health and ecosystems demands monitoring systems that weight the spectral irradiance according to the biological responses under consideration. In general, there are three different approaches to quantify a biologically effective solar irradiance: (i) weighted spectroradiometry where the biologically weighted radiometric quantities are derived from spectral data by multiplication with an action spectrum of a relevant photobiological reaction, e.g. erythema, DNA damage, skin cancer, reduced productivity of terrestrial plants and aquatic foodweb; (ii) wavelength integrating chemical-based or physical dosimetric systems with spectral sensitivities similar to a biological response curve; and (iii) biological dosimeters that directly weight the incident UV components of sunlight in relation to the effectiveness of the different wavelengths and to interactions between them. Most biological dosimeters, such as bacteria, bacteriophages, or biomolecules, are based on the UV sensitivity of DNA. If precisely characterized, biological dosimeters are applicable as field and personal dosimeters.

  7. Biological effects of prenatal irradiation

    International Nuclear Information System (INIS)

    Streffer, Christian

    1997-01-01

    After large releases of radionuclides, exposure of the embryo or fetus can take place by external irradiation or uptake of radionuclies. The embryo and fetus are radiosensitive throughout prenatal development. The quality and extent of radiation effects depend on the development stage. During the preimplantation period (one to 10 days postconception, p.c.) a radiation exposure of at least 0.2 Gy can cause the death of the embryo. Malformations are only observed in rare cases when genetic predisposition exist. Macroscopic, anatomical malformations are induced only after irradiation during the major organogenesis (two to eight weeks p.c.). A radiation dose of about 0.2 Gy is a doubling dose for the malformation risks as extrapolated from experiments with rodents. The human embryo may be more radioresistant. During early fetogenesis (8-15 weeks p.c.) a high radiosensitivity exists for the developmental of the brain. Radiation doses of 1.0 Gy cause severe mental retardation in about 40% of the exposed fetuses. It must be taken into account that a radiation exposure during the fetal period can also induce cancer. It is generally assumed that the risk exists at about the same level as for children. (Author)

  8. Biological effects of high LET radiations

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Masami [Nagasaki Univ. (Japan). Faculty of Pharmaceutical Sciences

    1997-03-01

    Biological effect of radiation is different by a kind of it greatly. Heavy ions were generally more effective in cell inactivation, chromosome aberration induction, mutation induction and neoplastic cell transformation induction than {gamma}-rays in SHE cells. (author)

  9. Qualitative reasoning for biological network inference from systematic perturbation experiments.

    Science.gov (United States)

    Badaloni, Silvana; Di Camillo, Barbara; Sambo, Francesco

    2012-01-01

    The systematic perturbation of the components of a biological system has been proven among the most informative experimental setups for the identification of causal relations between the components. In this paper, we present Systematic Perturbation-Qualitative Reasoning (SPQR), a novel Qualitative Reasoning approach to automate the interpretation of the results of systematic perturbation experiments. Our method is based on a qualitative abstraction of the experimental data: for each perturbation experiment, measured values of the observed variables are modeled as lower, equal or higher than the measurements in the wild type condition, when no perturbation is applied. The algorithm exploits a set of IF-THEN rules to infer causal relations between the variables, analyzing the patterns of propagation of the perturbation signals through the biological network, and is specifically designed to minimize the rate of false positives among the inferred relations. Tested on both simulated and real perturbation data, SPQR indeed exhibits a significantly higher precision than the state of the art.

  10. Magnetic resonance: safety measures and biological effects

    International Nuclear Information System (INIS)

    Gordillo, I.; Lafuente, J.; Fernandez, C.; Barbero, M.J.; Cascon, E.

    1997-01-01

    The biological effects of electromagnetic fields is currently a subject of great controversy. For this reason, magnetic resonance imaging (MRI) and spectroscopy are constantly under investigation. The source of the risk in MRI is associated with the three types of electromagnetic radiation to which the patient is exposed: the static magnetic field, variable (gradient) magnetic fields and radiofrequency fields. Each is capable of producing significant biological effects when employed at sufficient intensity. Patients exposed to risk sources are those situated within the lines of force of the magnetic field, ellipsoid lines that are arranged around the magnet, representing the strength of the surrounding field. To date, at the intensity normally utilized in MRI(<2T) and respecting the field limit recommendations established by the US Food and Drug Administration (FDA) for clinical use of this technique no adverse secondary biological effects have been reported. The known biological effects and other possible secondary effects are reviewed, and the recommended safety measures are discussed. (Author)

  11. A national comparison of biochemistry and molecular biology capstone experiences.

    Science.gov (United States)

    Aguanno, Ann; Mertz, Pamela; Martin, Debra; Bell, Ellis

    2015-01-01

    Recognizing the increasingly integrative nature of the molecular life sciences, the American Society for Biochemistry and Molecular Biology (ASBMB) recommends that Biochemistry and Molecular Biology (BMB) programs develop curricula based on concepts, content, topics, and expected student outcomes, rather than courses. To that end, ASBMB conducted a series of regional workshops to build a BMB Concept Inventory containing validated assessment tools, based on foundational and discipline-specific knowledge and essential skills, for the community to use. A culminating activity, which integrates the educational experience, is often part of undergraduate molecular life science programs. These "capstone" experiences are commonly defined as an attempt to measure student ability to synthesize and integrate acquired knowledge. However, the format, implementation, and approach to outcome assessment of these experiences are quite varied across the nation. Here we report the results of a nation-wide survey on BMB capstone experiences and discuss this in the context of published reports about capstones and the findings of the workshops driving the development of the BMB Concept Inventory. Both the survey results and the published reports reveal that, although capstone practices do vary, certain formats for the experience are used more frequently and similarities in learning objectives were identified. The use of rubrics to measure student learning is also regularly reported, but details about these assessment instruments are sparse in the literature and were not a focus of our survey. Finally, we outline commonalities in the current practice of capstones and suggest the next steps needed to elucidate best practices. © 2015 The International Union of Biochemistry and Molecular Biology.

  12. openBEB: open biological experiment browser for correlative measurements.

    Science.gov (United States)

    Ramakrishnan, Chandrasekhar; Bieri, Andrej; Sauter, Nora; Roizard, Sophie; Ringler, Philippe; Müller, Shirley A; Goldie, Kenneth N; Enimanev, Kaloyan; Stahlberg, Henning; Rinn, Bernd; Braun, Thomas

    2014-03-26

    New experimental methods must be developed to study interaction networks in systems biology. To reduce biological noise, individual subjects, such as single cells, should be analyzed using high throughput approaches. The measurement of several correlative physical properties would further improve data consistency. Accordingly, a considerable quantity of data must be acquired, correlated, catalogued and stored in a database for subsequent analysis. We have developed openBEB (open Biological Experiment Browser), a software framework for data acquisition, coordination, annotation and synchronization with database solutions such as openBIS. OpenBEB consists of two main parts: A core program and a plug-in manager. Whereas the data-type independent core of openBEB maintains a local container of raw-data and metadata and provides annotation and data management tools, all data-specific tasks are performed by plug-ins. The open architecture of openBEB enables the fast integration of plug-ins, e.g., for data acquisition or visualization. A macro-interpreter allows the automation and coordination of the different modules. An update and deployment mechanism keeps the core program, the plug-ins and the metadata definition files in sync with a central repository. The versatility, the simple deployment and update mechanism, and the scalability in terms of module integration offered by openBEB make this software interesting for a large scientific community. OpenBEB targets three types of researcher, ideally working closely together: (i) Engineers and scientists developing new methods and instruments, e.g., for systems-biology, (ii) scientists performing biological experiments, (iii) theoreticians and mathematicians analyzing data. The design of openBEB enables the rapid development of plug-ins, which will inherently benefit from the "house keeping" abilities of the core program. We report the use of openBEB to combine live cell microscopy, microfluidic control and visual

  13. Influence of the 192Ir source decay on biological effect

    International Nuclear Information System (INIS)

    Wang Shunbao; Feng Ningyuan; Niu Wenzhe; Yang Yuhui; Guo Lei

    1994-01-01

    Biological effect of the 192 Ir high activity source on LA 795 tumor of mice and HCT-8 cells have been investigated when decay of the source power from 340.4 GBq to 81.4 GBq no marked difference was found between the two cell survival curves of HCT-8 cells and both of them compared with that of the X-ray irradiation the value of relative biological effect (0.1 survival) was 0.43. On the experiment of tumor LA 795 of mice, when the source power was 293.3 GBq and 96.2 GBq, no different biological effect can be seen between the two series of figures. The relative biological effect was 0.55-0.60 (tumor growth delay) comparing with those of X-ray irradiation

  14. Biological Effects of Ionizing Radiation

    International Nuclear Information System (INIS)

    Durand, J.L.

    2000-01-01

    The aim of this work is to verify the existence of the adaptive response phenomenon induced by low doses of ionizing radiation in living cells.A wild-type yeast Saccharomyces cerevisiae (Baker's yeast) was chosen as the biological target.As a parameter to quantify the sensibility of the target to radiation, the Lethal Dose 50 (LD50 ) was observed. In our experimental condition a value of (60 ± 1) Gy was measured for LD50 with Dose Rate of (0.44 ± 0.03) Gy/min. The method employed to show up the adaptive response phenomenon consisted in exposing the sample to low ''conditioning'' doses, which would initiate these mechanisms. Later the samples with and without conditioning were exposed to higher ''challenging'' doses (such as LD50), and the surviving fractions were compared. In order to maximize the differences, the doses and the time between irradiations were varied. The best results were obtained with both a conditioning dose of (0.44 ± 0.03) Gy and a waiting time of 2 hs until the application of the challenging dose. Following this procedures the 80% of the conditioned samples has survived, after receiving the application of the LD50. The adaptive response phenomenon was also verified for a wide range of challenging doses

  15. Biological effects of radon in Drosophila

    International Nuclear Information System (INIS)

    Pimentel P, A.E.; Tavera D, L.; Cruces M, M.P.; Arceo M, C.; Rosa D, M.E. de la

    1992-04-01

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  16. Biological effects of nuclear radiation

    International Nuclear Information System (INIS)

    Hotz, G.

    1975-01-01

    After a brief survey about the main radiobiological effects caused by ionizing radiation, human symptoms after irradiation and incorporation are shown. The special radiotoxic effect of radionuclides which are chemically associated with metabolism-specific elements such as calcium and potassium is shown and methods of treatment are indicated. (ORU) [de

  17. The Climate Experiences of Students in Introductory Biology

    Directory of Open Access Journals (Sweden)

    Ramón S. Barthelemy

    2015-08-01

    Full Text Available Understanding course climate is important for improving students’ experiences and increasing the likelihood of their persistence in STEM fields. This study presents climate survey results from 523 students taking introductory biology at the University of Michigan. Principal component analysis revealed that a student’s climate experience is comprised of five main elements: comfort, school avoidance, relationship to course, academic stress, and discomfort. Of these climate factors, comfort, school avoidance, and relationship to course were significant predictors of course satisfaction, and academic stress was a significant predictor of persistence. The results indicated the importance of a positive climate that is facilitated by the instructor in order to promote a positive student experience. Climate may be an important metric for institutions to track across time and course.

  18. Biological effects of high-energy radiation

    International Nuclear Information System (INIS)

    Curtis, S.B.

    1976-01-01

    The biological effects of high-energy radiation are reviewed, with emphasis on the effects of the hadronic component. Proton and helium ion effects are similar to those of the more conventional and sparsely ionizing x- and γ-radiation. Heavy-ions are known to be more biologically effective, but the long term hazard from accumulated damage has yet to be assessed. Some evidence of widely varying but dramatically increased effectiveness of very high-energy (approximately 70 GeV) hadron beams is reviewed. Finally, the importance of the neutron component in many situations around high-energy accelerators is pointed out

  19. Biological effects of ionising radiation

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    The paper reports the proceedings of a conference organised jointly by Friends of the Earth (U.K.) and Greenpeace (International). The aim of the conference was to discuss the effects of low level radiation, particularly on man, within the terms of dose/risk relationships. The topics discussed included: sources of radiation, radiation discharges from nuclear establishments, predictive modelling of radiation hazards, radiation effects at Hiroshima, low dose effects and ICRP dose limits, variation in sensitivity to radiation, and the link between childhood cancer and nuclear power. (U.K.)

  20. [Side effects of biologic therapies in psoriasis].

    Science.gov (United States)

    Altenburg, A; Augustin, M; Zouboulis, C C

    2018-04-01

    The introduction of biologics has revolutionized the treatment of moderate to severe plaque psoriasis. Due to the continuous expansion of biological therapies for psoriasis, it is particularly important to acknowledge efficacy and safety of the compounds not only in clinical trials but also in long-term registry-based observational studies. Typical side effects and significant risks of antipsoriatic biologic therapies considering psoriatic control groups are presented. A selective literature search was conducted in PubMed and long-term safety studies of the psoriasis registries PsoBest, PSOLAR and BADBIR were evaluated. To assess the long-term safety of biologics, the evaluation of the course of large patient cohorts in long-term registries is of particular medical importance. Newer biologic drugs seem to exhibit a better safety profile than older ones.

  1. Biological effects of electromagnetic fields

    African Journals Online (AJOL)

    2012-02-28

    Feb 28, 2012 ... radiofrequency emitting sources are radars, mobile phones and their base stations, ... and industrial applications, could have effect on living organisms. ...... Hazards of Electromagnetic Pollution (Msc Thesis). Department of ...

  2. The biological effectiveness of antiproton irradiation

    International Nuclear Information System (INIS)

    Holzscheiter, Michael H.; Bassler, Niels; Agazaryan, Nzhde; Beyer, Gerd; Blackmore, Ewart; DeMarco, John J.; Doser, Michael; Durand, Ralph E.; Hartley, Oliver; Iwamoto, Keisuke S.; Knudsen, Helge V.; Landua, Rolf; Maggiore, Carl; McBride, William H.; Moller, Soren Pape; Petersen, Jorgen; Skarsgard, Lloyd D.; Smathers, James B.; Solberg, Timothy D.; Uggerhoj, Ulrik I.; Vranjes, Sanja; Withers, H. Rodney; Wong, Michelle; Wouters, Bradly G.

    2006-01-01

    Background and purpose: Antiprotons travel through tissue in a manner similar to that for protons until they reach the end of their range where they annihilate and deposit additional energy. This makes them potentially interesting for radiotherapy. The aim of this study was to conduct the first ever measurements of the biological effectiveness of antiprotons. Materials and methods: V79 cells were suspended in a semi-solid matrix and irradiated with 46.7 MeV antiprotons, 48 MeV protons, or 6 Co γ-rays. Clonogenic survival was determined as a function of depth along the particle beams. Dose and particle fluence response relationships were constructed from data in the plateau and Bragg peak regions of the beams and used to assess the biological effectiveness. Results: Due to uncertainties in antiproton dosimetry we defined a new term, called the biologically effective dose ratio (BEDR), which compares the response in a minimally spread out Bragg peak (SOBP) to that in the plateau as a function of particle fluence. This value was ∼3.75 times larger for antiprotons than for protons. This increase arises due to the increased dose deposited in the Bragg peak by annihilation and because this dose has a higher relative biological effectiveness (RBE). Conclusion: We have produced the first measurements of the biological consequences of antiproton irradiation. These data substantiate theoretical predictions of the biological effects of antiproton annihilation within the Bragg peak, and suggest antiprotons warrant further investigation

  3. Dosimetry and biological effects of fast neutrons

    International Nuclear Information System (INIS)

    Zoetelief, J.

    1981-01-01

    This thesis contains studies on two types of cellular damage: cell reproductive death and chromosome aberrations induced by irradiation with X rays, gamma rays and fast neutrons of different energies. A prerequisite for the performance of radiobiological experiments is the determination of the absorbed dose with a sufficient degree of accuracy and precision. Basic concepts of energy deposition by ionizing radiation and practical aspects of neutron dosimetry for biomedical purposes are discussed. Information on the relative neutron sensitivity of GM counters and on the effective point of measurement of ionization chambers for dosimetry of neutron and photon beams under free-in-air conditions and inside phantoms which are used to simulate the biological objects is presented. Different methods for neutron dosimetry are compared and the experimental techniques used for the investigations of cell reproductive death and chromosome aberrations induced by ionizing radiation of different qualities are presented. Dose-effect relations for induction cell inactivation and chromsome aberrations in three cultured cell lines for different radiation qualities are presented. (Auth.)

  4. Biological effects of proton radiation: an update

    International Nuclear Information System (INIS)

    Girdhani, S.; Hlatky, L.; Sachs, R.

    2015-01-01

    Proton radiation provides significant dosimetric advantages when compared with gamma radiation due to its superior energy deposition characteristics. Although the physical aspects of proton radiobiology are well understood, biological and clinical endpoints are understudied. The current practice to assume the relative biological effectiveness of low linear energy transfer (LET) protons to be a generic value of about 1.1 relative to photons likely obscures important unrecognised differentials in biological response between these radiation qualities. A deeper understanding of the biological properties induced by proton radiation would have both radiobiological and clinical impact. This article briefly points to some of the literature pertinent to the effects of protons on tissue-level processes that modify disease progression, such as angiogenesis, cell invasion and cancer metastasis. Recent findings hint that proton radiation may, in addition to offering improved radio-therapeutic targeting, be a means to provide a new dimension for increasing therapeutic benefits for patients by manipulating these tissue-level processes. (authors)

  5. Biological Effects of Electromagnetic Fields

    Science.gov (United States)

    2006-11-27

    Warning stimuli, as well as learning material, i.e. the numbers to recall, were presented binaurally via earphones at an intensity of 65dB sound...ensued in a remarkable increase in the yield of ES-derived spontaneously beating cardiomyocytes. Figure 3 Effect of MF on...move the mucus along a surface layer of saline. This is very likely that the cilia, beating with the frequency about few tenth of Hertz, generate some

  6. Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Pardo, M.E. [Instituto Nacional de Investigaciones Nucleares, Apdo. postal 18-1027, Col. Escandon 11801 Mexico DF (Mexico)], E-mail: memp@nuclear.inin.mx; Ley-Chavez, E. [ISSEMYM Toluca, Mexico DF (Mexico); Reyes-Frias, M.L. [Instituto Nacional de Investigaciones Nucleares, Apdo. postal 18-1027, Col. Escandon 11801 Mexico DF (Mexico); Rodriguez-Ferreyra, P. [Hospital ' Dr. Nicolas San Juan' , Toluca, Mexico DF (Mexico); Vazquez-Maya, L.; Salazar, M.A. [Hospital General de Mexico, Mexico DF (Mexico)

    2007-11-15

    Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is 'Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation'. At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders.

  7. Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

    Science.gov (United States)

    Martínez-Pardo, M. E.; Ley-Chávez, E.; Reyes-Frías, M. L.; Rodríguez-Ferreyra, P.; Vázquez-Maya, L.; Salazar, M. A.

    2007-11-01

    Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is "Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation". At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders.

  8. Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

    International Nuclear Information System (INIS)

    Martinez-Pardo, M.E.; Ley-Chavez, E.; Reyes-Frias, M.L.; Rodriguez-Ferreyra, P.; Vazquez-Maya, L.; Salazar, M.A.

    2007-01-01

    Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is 'Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation'. At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders

  9. National experience in radiosterelization or radiodescontamination of biological products

    International Nuclear Information System (INIS)

    Padron, E.; Romay, Z.; Otero, I.; Chavez, A.; Prieto, E.; Sainz, D.; Rodriguez, R.; Diaz, D.

    1997-01-01

    The ionizing radiations are especially important when other chemical and physical methods can't be used, or they don't give the result required, for which the employment of advanced technologies for the sterilization is found in ascent at world level. To such effect, the International Atomic Energy Agency has, sponsored a coordinated program for the radiosterilization of medical and biological products in Latin America, in which Cuba participates. (author) [es

  10. Lessons learned about spaceflight and cell biology experiments

    Science.gov (United States)

    Hughes-Fulford, Millie

    2004-01-01

    Conducting cell biology experiments in microgravity can be among the most technically challenging events in a biologist's life. Conflicting events of spaceflight include waiting to get manifested, delays in manifest schedules, training astronauts to not shake your cultures and to add reagents slowly, as shaking or quick injection can activate signaling cascades and give you erroneous results. It is important to select good hardware that is reliable. Possible conflicting environments in flight include g-force and vibration of launch, exposure of cells to microgravity for extended periods until hardware is turned on, changes in cabin gases and cosmic radiation. One should have an on-board 1-g control centrifuge in order to eliminate environmental differences. Other obstacles include getting your funding in a timely manner (it is not uncommon for two to three years to pass between notification of grant approval for funding and actually getting funded). That said, it is important to note that microgravity research is worthwhile since all terrestrial life evolved in a gravity field and secrets of biological function may only be answered by removing the constant of gravity. Finally, spaceflight experiments are rewarding and worth your effort and patience.

  11. The Picture Superiority Effect and Biological Education.

    Science.gov (United States)

    Reid, D. J.

    1984-01-01

    Discusses learning behaviors where the "picture superiority effect" (PSE) seems to be most effective in biology education. Also considers research methodology and suggests a new research model which allows a more direct examination of the strategies learners use when matching up picture and text in efforts to "understand"…

  12. Biological effects on the source of geoneutrinos

    DEFF Research Database (Denmark)

    Sleep, Norman H.; Bird, Dennis K.; Rosing, Minik Thorleif

    2013-01-01

    its bulk earth value of similar to 4; Pb isotope measurements on mantle-derived rocks yield low Th/U values, effectively averaged over geological time. The physics of the modern biological process is complicated, but the net effect is that much of the U in the mantle comes from subducted marine...

  13. Influencing attitudes toward science through field experiences in biology

    Science.gov (United States)

    Carpenter, Deborah Mcintyre

    The purpose of this study was to determine how student attitudes toward science are influenced by field experiences in undergraduate biology courses. The study was conducted using two institutions of higher education including a 2-year lower-level and a 2-year upper-level institution. Data were collected through interviews with student participants, focus group discussions, students' journal entries, and field notes recorded by the researcher during the field activities. Photographs and video recordings were also used as documentation sources. Data were collected over a period of 34 weeks. Themes that emerged from the qualitative data included students' beliefs that field experiences (a) positively influence student motivation to learn, (b) increase student ability to learn the concepts being taught, and (c) provide opportunities for building relationships and for personal growth. The findings of the study reinforce the importance of offering field-study programs at the undergraduate level to allow undergraduate students the opportunity to experience science activities in a field setting. The research study was framed by the behavioral and developmental theories of attitude and experience including the Theory of Planned Behavior (Ajzen, 1991) and the Theory of Experiential Learning (Kolb, 1984).

  14. The relative biological effectiveness of antiprotons

    DEFF Research Database (Denmark)

    Holzscheiter, Michael H.; Alsner, Jan; Bassler, Niels

    2016-01-01

    Background and purpose: Aside from the enhancement of physical dose deposited by antiprotons annihilating in tissue-like material compared to protons of the same range a further increase of biological effective dose has been demonstrated. This enhancement can be expressed in an increase of the re......Background and purpose: Aside from the enhancement of physical dose deposited by antiprotons annihilating in tissue-like material compared to protons of the same range a further increase of biological effective dose has been demonstrated. This enhancement can be expressed in an increase...... of the relative biological effectiveness (RBE) of antiprotons near the end of range. We have performed the first-ever direct measurement of the RBE of antiprotons both at rest and in flight. Materials and methods: Experimental data were generated on the RBE of an antiproton beam entering a tissue-like target...

  15. Biological Effects of Low-Dose Exposure

    CERN Document Server

    Komochkov, M M

    2000-01-01

    On the basis of the two-protection reaction model an analysis of stochastic radiobiological effects of low-dose exposure of different biological objects has been carried out. The stochastic effects are the results published in the last decade: epidemiological studies of human cancer mortality, the yield of thymocyte apoptosis of mice and different types of chromosomal aberrations. The results of the analysis show that as dependent upon the nature of biological object, spontanous effect, exposure conditions and radiation type one or another form dose - effect relationship is realized: downwards concave, near to linear and upwards concave with the effect of hormesis included. This result testifies to the incomplete conformity of studied effects of 1990 ICRP recomendations based on the linear no-threshold hypothesis about dose - effect relationship. Because of this the methodology of radiation risk estimation recomended by ICRP needs more precisian and such quantity as collective dose ought to be classified into...

  16. Biological effect of radionuclides on plants

    International Nuclear Information System (INIS)

    Prister, B.S.; Khal'chenko, V.A.; Polyakova, V.Y.; Shevchenko, V.A.; Shejn, G.P.; Aleksakhin, R.M.

    1979-01-01

    Stated are dosimetry principles and given is an analysis of biological radionuclide effect on plants in aerial and root intakes. A comparative barley radiosensitivity characteristic depending on plant development phases during irradiation is given using LD 50 criteria. Considered is a possibility for using generalized bioinformation parameters as sensitive indications for estimating biological effects due to the influence of low radiation doses. On the grounds of data obtained generalization are forecasted probable losses of crops when getting radionuclides into plants during various vegetation periods

  17. Ionising radiation - physical and biological effects

    International Nuclear Information System (INIS)

    Holter, Oe.; Ingebretsen, F.; Parr, H.

    1979-01-01

    The physics of ionising radiation is briefly presented. The effects of ionising radiation on biological cells, cell repair and radiosensitivity are briefly treated, where after the effects on man and mammals are discussed and related to radiation doses. Dose limits are briefly discussed. The genetic effects are discussed separately. Radioecology is also briefly treated and a table of radionuclides deriving from reactors, and their radiation is given. (JIW)

  18. Biological effectiveness of neutrons: Research needs

    Energy Technology Data Exchange (ETDEWEB)

    Casarett, G.W.; Braby, L.A.; Broerse, J.J.; Elkind, M.M.; Goodhead, D.T.; Oleinick, N.L.

    1994-02-01

    The goal of this report was to provide a conceptual plan for a research program that would provide a basis for determining more precisely the biological effectiveness of neutron radiation with emphasis on endpoints relevant to the protection of human health. This report presents the findings of the experts for seven particular categories of scientific information on neutron biological effectiveness. Chapter 2 examines the radiobiological mechanisms underlying the assumptions used to estimate human risk from neutrons and other radiations. Chapter 3 discusses the qualitative and quantitative models used to organize and evaluate experimental observations and to provide extrapolations where direct observations cannot be made. Chapter 4 discusses the physical principles governing the interaction of radiation with biological systems and the importance of accurate dosimetry in evaluating radiation risk and reducing the uncertainty in the biological data. Chapter 5 deals with the chemical and molecular changes underlying cellular responses and the LET dependence of these changes. Chapter 6, in turn, discusses those cellular and genetic changes which lead to mutation or neoplastic transformation. Chapters 7 and 8 examine deterministic and stochastic effects, respectively, and the data required for the prediction of such effects at different organizational levels and for the extrapolation from experimental results in animals to risks for man. Gaps and uncertainties in this data are examined relative to data required for establishing radiation protection standards for neutrons and procedures for the effective and safe use of neutron and other high-LET radiation therapy.

  19. Biological effectiveness of neutrons: Research needs

    International Nuclear Information System (INIS)

    Casarett, G.W.; Braby, L.A.; Broerse, J.J.; Elkind, M.M.; Goodhead, D.T.; Oleinick, N.L.

    1994-02-01

    The goal of this report was to provide a conceptual plan for a research program that would provide a basis for determining more precisely the biological effectiveness of neutron radiation with emphasis on endpoints relevant to the protection of human health. This report presents the findings of the experts for seven particular categories of scientific information on neutron biological effectiveness. Chapter 2 examines the radiobiological mechanisms underlying the assumptions used to estimate human risk from neutrons and other radiations. Chapter 3 discusses the qualitative and quantitative models used to organize and evaluate experimental observations and to provide extrapolations where direct observations cannot be made. Chapter 4 discusses the physical principles governing the interaction of radiation with biological systems and the importance of accurate dosimetry in evaluating radiation risk and reducing the uncertainty in the biological data. Chapter 5 deals with the chemical and molecular changes underlying cellular responses and the LET dependence of these changes. Chapter 6, in turn, discusses those cellular and genetic changes which lead to mutation or neoplastic transformation. Chapters 7 and 8 examine deterministic and stochastic effects, respectively, and the data required for the prediction of such effects at different organizational levels and for the extrapolation from experimental results in animals to risks for man. Gaps and uncertainties in this data are examined relative to data required for establishing radiation protection standards for neutrons and procedures for the effective and safe use of neutron and other high-LET radiation therapy

  20. Biologic effects of electromagnetic radiation and microwave

    International Nuclear Information System (INIS)

    Deng Hua

    2002-01-01

    Electromagnetic radiation and microwave exist mankind's environment widely. People realize they disserve authors' health when authors make use of them. Electromagnetic radiation is one of the major physic factors which injure people's health. A review of the biologic mechanism about electromagnetic radiation and microwave, their harmful effects to human body, problems in authors' research and the prospect

  1. Biological radiation effects and radioprotection standards

    International Nuclear Information System (INIS)

    Clerc, H.

    1991-03-01

    In this report, after recalling the mode of action of ionizing radiations, the notions of dose, dose equivalents and the values of natural irradiation, the author describes the biological radiation effects. Then he presents the ICRP recommendations and their applications to the french radioprotection system

  2. Study of biological effect of radiation

    International Nuclear Information System (INIS)

    Li Guisheng

    1992-01-01

    The some progress on the study of biological effect for protract exposure to low dose rate radiation is reported, and it is indicated that the potential risk of this exposure for the human health and the importance of the routine monitoring of radiation dose for various nuclear installations. The potential exposure to the low dose rate radiation would attract people's extra attention

  3. Nuclear energy: biological effects and environmental impact

    International Nuclear Information System (INIS)

    Boonefaes, M.

    1987-01-01

    This thesis is concerned with the large development of nuclear power plants and the recent nuclear catastrophe which has made clear how the hazards resulting from radioactivity affect public health and the environment. Environmental effects of nuclear power plants operating in normal conditions are small, but to obtain nuclear power plants of reduced radioactivity, optimization of their design, construction, operation and waste processing plays a decisive role. Biological effects of ionizing radiations and environmental impacts of Nuclear Power plants are developed [fr

  4. Biological Effects of Neutron and Proton Irradiations. Vol. II. Proceedings of the Symposium on Biological Effects of Neutron Irradiations

    International Nuclear Information System (INIS)

    1964-01-01

    the importance of radiobiological investigations with neutrons for applied sciences; the topics discussed in these papers were the use of neutron irradiation in agriculture, applied genetics and radiotherapy; some results of research work on the biological action of neutrons and protons were also presented. The two-volume Proceedings of this Symposium should assist in promoting research on the biological effect of neutron and proton irradiation and help countries where no biological experiments with neutrons are yet being carried out

  5. Lunar biological effects and the magnetosphere.

    Science.gov (United States)

    Bevington, Michael

    2015-12-01

    The debate about how far the Moon causes biological effects has continued for two millennia. Pliny the Elder argued for lunar power "penetrating all things", including plants, fish, animals and humans. He also linked the Moon with tides, confirmed mathematically by Newton. A review of modern studies of biological effects, especially from plants and animals, confirms the pervasive nature of this lunar force. However calculations from physics and other arguments refute the supposed mechanisms of gravity and light. Recent space exploration allows a new approach with evidence of electromagnetic fields associated with the Earth's magnetotail at full moon during the night, and similar, but more limited, effects from the Moon's wake on the magnetosphere at new moon during the day. The disturbance of the magnetotail is perhaps shown by measurements of electric fields of up to 16V/m compared with the usual lunar biological effects, such as acute myocardial infarction, could help the development of strategies to reduce adverse effects for people sensitive to geomagnetic disturbance. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  6. Progranulin and its biological effects in cancer.

    Science.gov (United States)

    Arechavaleta-Velasco, Fabian; Perez-Juarez, Carlos Eduardo; Gerton, George L; Diaz-Cueto, Laura

    2017-11-07

    Cancer cells have defects in regulatory mechanisms that usually control cell proliferation and homeostasis. Different cancer cells share crucial alterations in cell physiology, which lead to malignant growth. Tumorigenesis or tumor growth requires a series of events that include constant cell proliferation, promotion of metastasis and invasion, stimulation of angiogenesis, evasion of tumor suppressor factors, and avoidance of cell death pathways. All these events in tumor progression may be regulated by growth factors produced by normal or malignant cells. The growth factor progranulin has significant biological effects in different types of cancer. This protein is a regulator of tumorigenesis because it stimulates cell proliferation, migration, invasion, angiogenesis, malignant transformation, resistance to anticancer drugs, and immune evasion. This review focuses on the biological effects of progranulin in several cancer models and provides evidence that this growth factor should be considered as a potential biomarker and target in cancer treatment.

  7. THz waves: biological effects, industrial and medical

    International Nuclear Information System (INIS)

    Coutaz, J.L.; Garet, F.; Le Drean, Y.; Zhadobov, M.; Veyret, B.; Mounaix, P.; Caumes, J.P.; Gallot, G.; Gian Piero, Gallerano; Mouret, G.; Guilpin, J.C.

    2011-01-01

    Following the debates about body scanners installed in airports for passengers security control, the non-ionizing radiations (NIR) section of the French radiation protection society (SFR) has organized a conference day to take stock of the present day knowledge about the physical aspects and the biological effects of this frequency range as well as about their medical, and industrial applications (both civil and military). This document gathers the slides of the available presentations: 1 - introduction and general considerations about THz waves, the THz physical phenomenon among NIR (J.L. Coutaz); 2 - interaction of millimeter waves with living material: from dosimetry to biological impacts (Y. Le Drean and M. Zhadobov); 3 - Tera-Hertz: standards and recommendations (B. Veyret); 4 - THz spectro-imaging technique: status and perspectives (P. Mounaix); 5 - THz technology: seeing the invisible? (J.P. Caumes); 6 - Tera-Hertz: biological and medical applications (G. Gallot); 7 - Biological applications of THz radiation: a review of events and a glance to the future (G.P. Gallerano); 8 - Industrial and military applications - liquids and solids detection in the THz domain (F. Garet); 9 - THz radiation and its civil and military applications - gas detection and quantifying (G. Mouret); 10 - Body scanners and civil aviation security (J.C. Guilpin, presentation not available). (J.S.)

  8. Electromagnetic effects - From cell biology to medicine.

    Science.gov (United States)

    Funk, Richard H W; Monsees, Thomas; Ozkucur, Nurdan

    2009-01-01

    In this review we compile and discuss the published plethora of cell biological effects which are ascribed to electric fields (EF), magnetic fields (MF) and electromagnetic fields (EMF). In recent years, a change in paradigm took place concerning the endogenously produced static EF of cells and tissues. Here, modern molecular biology could link the action of ion transporters and ion channels to the "electric" action of cells and tissues. Also, sensing of these mainly EF could be demonstrated in studies of cell migration and wound healing. The triggers exerted by ion concentrations and concomitant electric field gradients have been traced along signaling cascades till gene expression changes in the nucleus. Far more enigmatic is the way of action of static MF which come in most cases from outside (e.g. earth magnetic field). All systems in an organism from the molecular to the organ level are more or less in motion. Thus, in living tissue we mostly find alternating fields as well as combination of EF and MF normally in the range of extremely low-frequency EMF. Because a bewildering array of model systems and clinical devices exits in the EMF field we concentrate on cell biological findings and look for basic principles in the EF, MF and EMF action. As an outlook for future research topics, this review tries to link areas of EF, MF and EMF research to thermodynamics and quantum physics, approaches that will produce novel insights into cell biology.

  9. Biological effect of aerospace environment on alfalfa

    International Nuclear Information System (INIS)

    Zhang Yuexue; Liu Jielin; Han Weibo; Tang Fenglan; Hao Ruochao; Shang Chen; DuYouying; Li Jikai; Wang Changshan

    2009-01-01

    The biological effect of aerospace environment on two varieties of Medicago sativa L. was studied. In M 1 germination results showed that aerospace environment increased cell division and the number of micronucleus, changed germination rate, caused seedling aberrations. Cytogenetical and seedling aberration of Zhaodong showed more sensitivity than Longmu 803. Branches and fresh weight of Zhaodong had shown more serious damage than control and Longmu 803. (authors)

  10. Experiences with effects specifications

    DEFF Research Database (Denmark)

    Simonsen, Jesper; Hertzum, Morten; Barlach, Anders

    2011-01-01

    We describe the effects-specification process from a project that was conducted during the fall 2010 and spring of 2011 in this chapter. The project configured and implemented an electronic patient record system at a maternity ward at a hospital located in a European region. The process comprised...... workshops with effects specification with management and end-users and an agile development process including prototypes configured from the effects specifications. We describe the project and the effects-specification process through which effects were related to the system design and instruments...... for measuring effects were designed. The project is analyzed and lessons learned are discussed....

  11. The Biological Effects of Bilirubin Photoisomers

    Science.gov (United States)

    Jasprova, Jana; Dal Ben, Matteo; Vianello, Eleonora; Goncharova, Iryna; Urbanova, Marie; Vyroubalova, Karolina; Gazzin, Silvia; Tiribelli, Claudio; Sticha, Martin; Cerna, Marcela; Vitek, Libor

    2016-01-01

    Although phototherapy was introduced as early as 1950’s, the potential biological effects of bilirubin photoisomers (PI) generated during phototherapy remain unclear. The aim of our study was to isolate bilirubin PI in their pure forms and to assess their biological effects in vitro. The three major bilirubin PI (ZE- and EZ-bilirubin and Z-lumirubin) were prepared by photo-irradiation of unconjugated bilirubin. The individual photoproducts were chromatographically separated (TLC, HPLC), and their identities verified by mass spectrometry. The role of Z-lumirubin (the principle bilirubin PI) on the dissociation of bilirubin from albumin was tested by several methods: peroxidase, fluorescence quenching, and circular dichroism. The biological effects of major bilirubin PI (cell viability, expression of selected genes, cell cycle progression) were tested on the SH-SY5Y human neuroblastoma cell line. Lumirubin was found to have a binding site on human serum albumin, in the subdomain IB (or at a close distance to it); and thus, different from that of bilirubin. Its binding constant to albumin was much lower when compared with bilirubin, and lumirubin did not affect the level of unbound bilirubin (Bf). Compared to unconjugated bilirubin, bilirubin PI did not have any effect on either SH-SY5Y cell viability, the expression of genes involved in bilirubin metabolism or cell cycle progression, nor in modulation of the cell cycle phase. The principle bilirubin PI do not interfere with bilirubin albumin binding, and do not exert any toxic effect on human neuroblastoma cells. PMID:26829016

  12. Microwave radiation - Biological effects and exposure standards

    Energy Technology Data Exchange (ETDEWEB)

    Lindsay, I.R.

    1980-06-01

    The thermal and nonthermal effects of exposure to microwave radiation are discussed and current standards for microwave exposure are examined in light of the proposed use of microwave power transmission from solar power satellites. Effects considered include cataractogenesis at levels above 100 mW/sq cm, and possible reversible disturbances such as headaches, sleeplessness, irritability, fatigue, memory loss, cardiovascular changes and circadian rhythm disturbances at levels less than 10 mW/sq cm. It is pointed out that while the United States and western Europe have adopted exposure standards of 10 mW/sq cm, those adopted in other countries are up to three orders of magnitude more restrictive, as they are based on different principles applied in determining safe limits. Various aspects of the biological effects of microwave transmissions from space are considered in the areas of the protection of personnel working in the vicinity of the rectenna, interactions of the transmitted radiation with cardiac pacemakers, and effects on birds. It is concluded that thresholds for biological effects from short-term microwave radiation are well above the maximal power density of 1 mW/sq cm projected at or beyond the area of exclusion of a rectenna.

  13. Bystander effect: Biological endpoints and microarray analysis

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhry, M. Ahmad [Department of Medical Laboratory and Radiation Sciences, College of Nursing and Health Sciences, University of Vermont, 302 Rowell Building, Burlington, VT 05405 (United States) and DNA Microarray Facility, University of Vermont, Burlington, VT 05405 (United States)]. E-mail: mchaudhr@uvm.edu

    2006-05-11

    In cell populations exposed to ionizing radiation, the biological effects occur in a much larger proportion of cells than are estimated to be traversed by radiation. It has been suggested that irradiated cells are capable of providing signals to the neighboring unirradiated cells resulting in damage to these cells. This phenomenon is termed the bystander effect. The bystander effect induces persistent, long-term, transmissible changes that result in delayed death and neoplastic transformation. Because the bystander effect is relevant to carcinogenesis, it could have significant implications for risk estimation for radiation exposure. The nature of the bystander effect signal and how it impacts the unirradiated cells remains to be elucidated. Examination of the changes in gene expression could provide clues to understanding the bystander effect and could define the signaling pathways involved in sustaining damage to these cells. The microarray technology serves as a tool to gain insight into the molecular pathways leading to bystander effect. Using medium from irradiated normal human diploid lung fibroblasts as a model system we examined gene expression alterations in bystander cells. The microarray data revealed that the radiation-induced gene expression profile in irradiated cells is different from unirradiated bystander cells suggesting that the pathways leading to biological effects in the bystander cells are different from the directly irradiated cells. The genes known to be responsive to ionizing radiation were observed in irradiated cells. Several genes were upregulated in cells receiving media from irradiated cells. Surprisingly no genes were found to be downregulated in these cells. A number of genes belonging to extracellular signaling, growth factors and several receptors were identified in bystander cells. Interestingly 15 genes involved in the cell communication processes were found to be upregulated. The induction of receptors and the cell

  14. Bystander effect: Biological endpoints and microarray analysis

    International Nuclear Information System (INIS)

    Chaudhry, M. Ahmad

    2006-01-01

    In cell populations exposed to ionizing radiation, the biological effects occur in a much larger proportion of cells than are estimated to be traversed by radiation. It has been suggested that irradiated cells are capable of providing signals to the neighboring unirradiated cells resulting in damage to these cells. This phenomenon is termed the bystander effect. The bystander effect induces persistent, long-term, transmissible changes that result in delayed death and neoplastic transformation. Because the bystander effect is relevant to carcinogenesis, it could have significant implications for risk estimation for radiation exposure. The nature of the bystander effect signal and how it impacts the unirradiated cells remains to be elucidated. Examination of the changes in gene expression could provide clues to understanding the bystander effect and could define the signaling pathways involved in sustaining damage to these cells. The microarray technology serves as a tool to gain insight into the molecular pathways leading to bystander effect. Using medium from irradiated normal human diploid lung fibroblasts as a model system we examined gene expression alterations in bystander cells. The microarray data revealed that the radiation-induced gene expression profile in irradiated cells is different from unirradiated bystander cells suggesting that the pathways leading to biological effects in the bystander cells are different from the directly irradiated cells. The genes known to be responsive to ionizing radiation were observed in irradiated cells. Several genes were upregulated in cells receiving media from irradiated cells. Surprisingly no genes were found to be downregulated in these cells. A number of genes belonging to extracellular signaling, growth factors and several receptors were identified in bystander cells. Interestingly 15 genes involved in the cell communication processes were found to be upregulated. The induction of receptors and the cell

  15. Biological effects of transuranium elements in experimental animals

    International Nuclear Information System (INIS)

    Bair, W.J.

    1975-01-01

    Results are reported from life span studies of the biological effects of the transuranium elements ( 238 Pu, 239 Pu, 241 Am, and 242 Cm) on laboratory animals following inhalation, skin absorption, or injection in various chemical forms. The dose levels at which major biological effects have been observed in experimental animals are discussed relative to the maximum permissible lung burden of 0.016 μCi for occupational exposures. Lung cancer has been observed at dose levels equivalent to about 100 times the maximum permissible lung burden. Current experiments directed towards determining whether health effects will occur at lower levels and the mechanisms by which α emitters induce cancer are reviewed. (U.S.)

  16. A National Comparison of Biochemistry and Molecular Biology Capstone Experiences

    Science.gov (United States)

    Aguanno, Ann; Mertz, Pamela; Martin, Debra; Bell, Ellis

    2015-01-01

    Recognizing the increasingly integrative nature of the molecular life sciences, the "American Society for Biochemistry and Molecular Biology" (ASBMB) recommends that Biochemistry and Molecular Biology (BMB) programs develop curricula based on concepts, content, topics, and expected student outcomes, rather than courses. To that end,…

  17. Single-molecule experiments in biological physics: methods and applications.

    Science.gov (United States)

    Ritort, F

    2006-08-16

    I review single-molecule experiments (SMEs) in biological physics. Recent technological developments have provided the tools to design and build scientific instruments of high enough sensitivity and precision to manipulate and visualize individual molecules and measure microscopic forces. Using SMEs it is possible to manipulate molecules one at a time and measure distributions describing molecular properties, characterize the kinetics of biomolecular reactions and detect molecular intermediates. SMEs provide additional information about thermodynamics and kinetics of biomolecular processes. This complements information obtained in traditional bulk assays. In SMEs it is also possible to measure small energies and detect large Brownian deviations in biomolecular reactions, thereby offering new methods and systems to scrutinize the basic foundations of statistical mechanics. This review is written at a very introductory level, emphasizing the importance of SMEs to scientists interested in knowing the common playground of ideas and the interdisciplinary topics accessible by these techniques. The review discusses SMEs from an experimental perspective, first exposing the most common experimental methodologies and later presenting various molecular systems where such techniques have been applied. I briefly discuss experimental techniques such as atomic-force microscopy (AFM), laser optical tweezers (LOTs), magnetic tweezers (MTs), biomembrane force probes (BFPs) and single-molecule fluorescence (SMF). I then present several applications of SME to the study of nucleic acids (DNA, RNA and DNA condensation) and proteins (protein-protein interactions, protein folding and molecular motors). Finally, I discuss applications of SMEs to the study of the nonequilibrium thermodynamics of small systems and the experimental verification of fluctuation theorems. I conclude with a discussion of open questions and future perspectives.

  18. Single-molecule experiments in biological physics: methods and applications

    International Nuclear Information System (INIS)

    Ritort, F

    2006-01-01

    I review single-molecule experiments (SMEs) in biological physics. Recent technological developments have provided the tools to design and build scientific instruments of high enough sensitivity and precision to manipulate and visualize individual molecules and measure microscopic forces. Using SMEs it is possible to manipulate molecules one at a time and measure distributions describing molecular properties, characterize the kinetics of biomolecular reactions and detect molecular intermediates. SMEs provide additional information about thermodynamics and kinetics of biomolecular processes. This complements information obtained in traditional bulk assays. In SMEs it is also possible to measure small energies and detect large Brownian deviations in biomolecular reactions, thereby offering new methods and systems to scrutinize the basic foundations of statistical mechanics. This review is written at a very introductory level, emphasizing the importance of SMEs to scientists interested in knowing the common playground of ideas and the interdisciplinary topics accessible by these techniques. The review discusses SMEs from an experimental perspective, first exposing the most common experimental methodologies and later presenting various molecular systems where such techniques have been applied. I briefly discuss experimental techniques such as atomic-force microscopy (AFM), laser optical tweezers (LOTs), magnetic tweezers (MTs), biomembrane force probes (BFPs) and single-molecule fluorescence (SMF). I then present several applications of SME to the study of nucleic acids (DNA, RNA and DNA condensation) and proteins (protein-protein interactions, protein folding and molecular motors). Finally, I discuss applications of SMEs to the study of the nonequilibrium thermodynamics of small systems and the experimental verification of fluctuation theorems. I conclude with a discussion of open questions and future perspectives. (topical review)

  19. Radiobiology: Biologic effects of ionizing radiations

    International Nuclear Information System (INIS)

    Held, K.D.

    1987-01-01

    The biologic effects after exposure to ionizing radiation, such as cell death or tissue injury, result from a chain of complex physical, chemical, metabolic, and histologic events. The time scale of these radiation actions spans many orders of magnitude. The physical absorption of ionizing radiation occurs in about 10 -18 s, while late carcinogenic and genetic effects are expressed years or even generations later. Collectively, these effects form the science of radiobiology. Many of the concepts discussed in this chapter have been developed through the study of effects generated in tissues by external radiation sources, but they apply generally and often specifically to internally distributed radiopharmaceuticals which form the central topic of this book

  20. The biological effects of low doses of radiation: medical, biological and ecological aspects

    International Nuclear Information System (INIS)

    Gun-Aajav, T.; Ajnai, L.; Manlaijav, G.

    2007-01-01

    Full text: The results of recent studies show that low doses of radiation make many different structural and functional changes in a cell and these changes are preserved for a long time. This phenomenon is called as effects of low doses of radiation in biophysics, radiation biology and radiation medicine. The structural and functional changes depend on doses and this dependence has non-linear and bimodal behaviour. More detail, the radiation effect goes up and reaches its maximum (Low doses maximum) in low doses region, then it goes down and takes its stationary means (there is a negative effect in a few cases). With increases in doses and with further increases it goes up. It is established that low dose's maximum depends on physiological state of a biological object, radiation quality and dose rate. During the experiments another special date was established. This specialty is that many different physical and chemical factors are mutually connected and have synergetic behaviour. At present, researches are concentrating their attention on the following three directions: 1. Direct and indirect interaction of radiation's low doses: 2. Interpretation of its molecular mechanism, regulation of the positive effects and elaboration of ways o removing negative effects: 3. Application of the objective research results into practice. In conclusion the authors mention the current concepts on interpretation of low doses effect mechanism, forward their own views and emphasize the importance of considering low doses effects in researches of environmental radiation pollution, radiation medicine and radiation protection. (author)

  1. Biological effects data: Fluoride and sulfur dioxide

    Energy Technology Data Exchange (ETDEWEB)

    McMechan, K.J. (ed.); Holton, R.L.; Ulbricht, R.J.; Morgan , J.B.

    1975-04-01

    The Alumax Pacific Aluminum Corporation has proposed construction of an aluminum reduction facility near Youngs Bay at Warrenton, Oregon. This report comprises one part of the final report to Alumax on a research project entitled, Physical, Chemical and Biological Studies of Youngs Bay.'' It presents data pertaining to the potential biological effects of fluoride and sulfur dioxide, two potentially hazardous plant-stack emissions, on selected aquatic species of the area. Companion volumes provide a description of the physical characteristics the geochemistry, and the aquatic animals present in Youngs Bay and adjacent ecosystems. An introductory volume provides general information and maps of the area, and summarizes the conclusions of all four studies. The data from the two phases of the experimental program are included in this report: lethal studies on the effects of selected levels of fluoride and sulfur dioxide on the survival rate of eleven Youngs Bay faunal species from four phyla, and sublethal studies on the effects of fluoride and sulfur dioxide on the rate of primary production of phytoplankton. 44 refs., 18 figs., 38 tabs.

  2. Xenon preconditioning: molecular mechanisms and biological effects

    Directory of Open Access Journals (Sweden)

    Liu Wenwu

    2013-01-01

    Full Text Available Abstract Xenon is one of noble gases and has been recognized as an anesthetic for more than 50 years. Xenon possesses many of the characteristics of an ideal anesthetic, but it is not widely applied in clinical practice mainly because of its high cost. In recent years, numerous studies have demonstrated that xenon as an anesthetic can exert neuroprotective and cardioprotective effects in different models. Moreover, xenon has been applied in the preconditioning, and the neuroprotective and cardioprotective effects of xenon preconditioning have been investigated in a lot of studies in which some mechanisms related to these protections are proposed. In this review, we summarized these mechanisms and the biological effects of xenon preconditioning.

  3. Radiobiological experiments with heavy ions: a comparison of the cross sections of different biological endpoints

    International Nuclear Information System (INIS)

    Kraft, G.

    1989-01-01

    Biological effect of heavy charged particles was studied in experiment at the Unilac on different physical, chemical and biological levels. On these experiments a large body of radiobiological data, cross sections for cell inactivation and mutation, induction of both, chromosome aberrations, and strand breaks, of DNA have been measured for different atomic numbers, from helium (z=2) to uranium (z=92), and at an LET range from 10 to 16000 keV/μm. At LET values below 100 keV/μm all data points to one specific effect form one single curve as a function of LET, independent of the atomic number of the ion. In this LET range the biological effects are independent of the particle energy or track structure and depend only on the energy transfer. Therefore LET is a good parameter in this regime. For LET values greater than 100 keV/μm this regime LET is no longer a good parameter and the physical parameters of the formation of particle track are important. The energy and angular distribution of the electrons in a solid target has to be measured. 28 refs.; 14 figs

  4. Crucible: A System for Space Synthetic Biology Experiments

    Data.gov (United States)

    National Aeronautics and Space Administration — The goal of this project is to expand the capability and methodologies in experimental extreme biology as a step towards Martian ecopoiesis. The objectives in...

  5. openBEB: open biological experiment browser for correlative measurements

    OpenAIRE

    Ramakrishnan, Chandrasekhar; Bieri, Andrej; Sauter, Nora; Roizard, Sophie; Ringler, Philippe; Müller, Shirley A; Goldie, Kenneth N; Enimanev, Kaloyan; Stahlberg, Henning; Rinn, Bernd; Braun, Thomas

    2014-01-01

    Background: New experimental methods must be developed to study interaction networks in systems biology. To reduce biological noise, individual subjects, such as single cells, should be analyzed using high throughput approaches. The measurement of several correlative physical properties would further improve data consistency. Accordingly, a considerable quantity of data must be acquired, correlated, catalogued and stored in a database for subsequent analysis. Results: We have developed openBE...

  6. Carbon loaded Teflon (CLT): a power density meter for biological experiments using millimeter waves.

    Science.gov (United States)

    Allen, Stewart J; Ross, James A

    2007-01-01

    The standard technique for measurement of millimeter wave fields utilizes an open-ended waveguide attached to a HP power meter. The alignment of the waveguide with the propagation (K) vector is critical to making accurate measurements. Using this technique, it is difficult and time consuming to make a detailed map of average incident power density over areas of biological interest and the spatial resolution of this instrument does not allow accurate measurements in non-uniform fields. For biological experiments, it is important to know the center field average incident power density and the distribution over the exposed area. Two 4 ft x 4 ft x 1/32 inch sheets of carbon loaded Teflon (CLT) (one 15% carbon and one 25% carbon) were procured and a series of tests to determine the usefulness of CLT in defining fields in the millimeter wavelength range was initiated. Since the CLT was to be used both in the laboratory, where the environment was well controlled, and in the field, where the environment could not be controlled, tests were made to determine effects of change in environmental conditions on ability to use CLT as a millimeter wave dosimeter. The empirical results of this study indicate CLT to be an effective dosimeter for biological experiments both in the laboratory and in the field.

  7. Biological radiation effects of Radon in Drosophila

    International Nuclear Information System (INIS)

    Pimentel P, A.E.

    1995-01-01

    In order to contribute to the knowledge on the effects of radon and its decay products, the aim of this investigation is to study the biological effects of radon using Drosophila melanogaster throught the somatic mutation and recombination test (SMART) and the analysis of some adaptative factors exposing larvaes to controlled radon atmosphers, considering that this insect could be used as biological monitor. Using the somatic mutation test a mutagenic effect was observed proportional to radon concentration, into an interval of 1 ± 0.3 to 111 ± 7.4 KBq/m 3 equivalent to doses under 0.0106 Gy. The correlation analysis gives a linear (r=0.80) relationship with a positive slope of 0.2217. The same happens when gamma rays are used in the interval of 1 to 20 Gy, given a linear dose-dependent effect (r=0.878) is obtained; nevetheless the slop is smaller (m=0.003) than for radon. Analysing the results of adaptative factors of the nine exposed generations, it was found that probably radon exposition induced dominant lethals during gametogenesis or/and a selection of the more component gamets of the treated individuals in larval state. It was reflected in the significant decrease on fecundity of the generation exposed. Nevertheless the laying eggs had an increase in egg-to-adult viability and the develop velocity was higher than in control for 3 KBq/m 3 , this suggest that radon concentrations used were able to induce repair mechanisms. These data agree with the Hormesis hypothesis that says: low doses have positive effects on health. It was not possible to obtain a dose-effect relationship except with the develop velocity where it was found a dose-effect inverse proportion. In conclusion, Drosophila melanogaster could be a good system to obtain in vivo damaged induction concentration dependent of radon and its decay products, as well as to study the effects in an exposed population by the analysis of adaptative factors. (Author)

  8. Biomedical Research Experiences for Biology Majors at a Small College

    Science.gov (United States)

    Stover, Shawn K.; Mabry, Michelle L.

    2010-01-01

    A program-level assessment of the biology curriculum at a small liberal arts college validates a previous study demonstrating success in achieving learning outcomes related to content knowledge and communication skills. Furthermore, research opportunities have been provided to complement pedagogical strategies and give students a more complete…

  9. Can Climate Change Enhance Biology Lessons? A Quasi-Experiment

    Science.gov (United States)

    Monroe, Martha C.; Hall, Stephanie; Li, Christine Jie

    2016-01-01

    Climate change is a highly charged topic that some adults prefer to ignore. If the same holds true for secondary students, teachers could be challenged to teach about climate change. We structured one activity about the biological concepts of carbon cycle and carbon sequestration in two ways: with and without mention of climate change. Results…

  10. Biological effects of deuterium - depleted water

    International Nuclear Information System (INIS)

    Stefanescu, I.; Titescu, Gh.; Croitoru, Cornelia; Saros-Rogobete, Irina

    2000-01-01

    Deuterium-depleted water (DDW) is represented by water that has an isotopic content smaller than 145 ppm D/(D + H). DDW production technique consists in the separation of deuterium from water by a continuous distillation process under pressure of about 133.3 mbar. The water used as raw material has a isotopic content of 145 ppm D/(D + H) and can be demineralized water, distillated water or condensed-steam. DDW results as a distillate with an isotopic deuterium content of 15-80 ppm, depending on the level we want to achieve. Beginning with 1996 the Institute of Cryogenics and Isotopic Technologies, DDW producer, co-operated with Romanian specialized institutes for studying the biological effects of DDW. The role of naturally occurring D in living organisms was examined by using DDW instead of natural water. These investigations led to the following conclusions: - DDW caused a tendency towards the increase of the basal tone, accompanied by the intensification of the vasoconstrictor effects of phenylefrine, noradrenaline and angiotensin; the increase of the basal tone and vascular reactivity produced by the DDW persists after the removal of the vascular endothelium; - Animals treated with DDW showed an increase of the resistance both to sublethal and lethal gamma radiation doses, suggesting a radioprotective action by the stimulation of non-specific immune defense mechanisms; - DDW stimulates immuno-defense reactions represented by the opsonic, bactericidal and phagocyte capacity of the immune system together with an increase in the number of poly-morphonuclear neutrophils; - Investigations regarding artificial reproduction of fish with DDW fecundated solutions confirmed favorable influence in embryo growth stage and resistance and following growth stages; - It was studied germination, growth and quantitative character variability in plants; one can remark the favorable influence of DDW on biological processes in plants in various ontogenetic stages. (authors)

  11. Food irradiation and its biological effects

    International Nuclear Information System (INIS)

    Shah, Alok; Nanjappa, C.; Chauhan, O.P.

    2014-01-01

    Irradiation of foods drew attention mostly in 1960s for disinfestation of food grains, spices and sprout inhibition in mainly potato and onion. γ-irradiation at 0.25 to 1 kGy dosage levels are usually used for irradiating grains, legumes, spices and sprout-prone vegetables. Irradiation of foods with in permissible dosage levels of 0.25 to 5 kGy is usually considered fairly safe from human consumption point of view not withstanding usual health concerns about its usage in foods. Irradiation of foods, in mostly solid or semi-solid form, at 5 kGy levels of γ-irradiation can achieve radicidation or, radiation equivalent of pasteurization and, if γ-irradiation is used at 10 kGy, it can achieve radappertization or, radiation equivalent of thermal commercial sterilization. However, the food industry uses γ-irradiation at 0.25 to 2 kGy only for mostly disinfestation of food grains/legumes, spices, sprout inhibition in potato and onion and, for surface sanitation of frozen fish, poultry and meat. Exposure to irradiation creates free radicals in foods that are capable of destroying some of the spoilage and pathogenic microflora but the same can also damage vitamins and enzymes besides creating some new harmful new chemical species, called unique radiolytic products (URPs), by combining with certain chemicals that a food may be laced with (like pesticides/fungicides). Exposure to high-energy electron beams are also known to create deleterious biological effects which may even lead to detection of trace amounts of radioactivity in the food. Some possible causes delineated for such harmful biological effects of irradiation include: irradiation induced vitamin deficiencies, the inactivity of enzymes in the foods, DNA damage and toxic radiolytic products in the foods. Irradiation, a non-thermal food preservation technique, has a role in salvaging enormous post harvest losses (25-30%) in developing economies to increase the per capita availability of foods. (author)

  12. Biological role of gravity: Hypotheses and results of experiments on ``Cosmos'' biosatellites

    Science.gov (United States)

    Alpatov, Alexey M.; Antipov, Vsevolod V.; Tairbekov, Murad G.

    In order to reveal the biological significance of gravity, microgravity effects have been studied at the cellular, organism and population levels. The following questions arise. Do any gravity - dependent processes exist in a cell? Is cell adaptation to weightlessness possible; if so, what role may cytoskeleton, the genetic apparatus play in it? What are the consequences of the lack of convection in weightlessness for the performance of morphogenesis? Do the integral characteristics of living beings change in weightlessness? Is there any change in ``biological capacity'' of space, its resistance to expansion of life? What are the direction and intensity of microgravity action as a factor of natural selection, the driving force of evolution? These problems are discussed from a theoretical point of view, and in the light of results obtained in experiments flown aboard biosatellites ``Cosmos''.

  13. Non-Chemical Distant Cellular Interactions as a potential confounder of Cell Biology Experiments

    Directory of Open Access Journals (Sweden)

    Ashkan eFarhadi

    2014-10-01

    Full Text Available Distant cells can communicate with each other through a variety of methods. Two such methods involve electrical and/or chemical mechanisms. Non-chemical, distant cellular interactions may be another method of communication that cells can use to modify the behavior of other cells that are mechanically separated. Moreover, non-chemical, distant cellular interactions may explain some cases of confounding effects in Cell Biology experiments. In this article, we review non-chemical, distant cellular interactions studies to try to shed light on the mechanisms in this highly unconventional field of cell biology. Despite the existence of several theories that try to explain the mechanism of non-chemical, distant cellular interactions, this phenomenon is still speculative. Among candidate mechanisms, electromagnetic waves appear to have the most experimental support. In this brief article, we try to answer a few key questions that may further clarify this mechanism.

  14. The prehistory of biology preprints: A forgotten experiment from the 1960s.

    Directory of Open Access Journals (Sweden)

    Matthew Cobb

    2017-11-01

    Full Text Available In 1961, the National Institutes of Health (NIH began to circulate biological preprints in a forgotten experiment called the Information Exchange Groups (IEGs. This system eventually attracted over 3,600 participants and saw the production of over 2,500 different documents, but by 1967, it was effectively shut down following the refusal of journals to accept articles that had been circulated as preprints. This article charts the rise and fall of the IEGs and explores the parallels with the 1990s and the biomedical preprint movement of today.

  15. The prehistory of biology preprints: A forgotten experiment from the 1960s.

    Science.gov (United States)

    Cobb, Matthew

    2017-11-01

    In 1961, the National Institutes of Health (NIH) began to circulate biological preprints in a forgotten experiment called the Information Exchange Groups (IEGs). This system eventually attracted over 3,600 participants and saw the production of over 2,500 different documents, but by 1967, it was effectively shut down following the refusal of journals to accept articles that had been circulated as preprints. This article charts the rise and fall of the IEGs and explores the parallels with the 1990s and the biomedical preprint movement of today.

  16. Complex fluids in biological systems experiment, theory, and computation

    CERN Document Server

    2015-01-01

    This book serves as an introduction to the continuum mechanics and mathematical modeling of complex fluids in living systems. The form and function of living systems are intimately tied to the nature of surrounding fluid environments, which commonly exhibit nonlinear and history dependent responses to forces and displacements. With ever-increasing capabilities in the visualization and manipulation of biological systems, research on the fundamental phenomena, models, measurements, and analysis of complex fluids has taken a number of exciting directions. In this book, many of the world’s foremost experts explore key topics such as: Macro- and micro-rheological techniques for measuring the material properties of complex biofluids and the subtleties of data interpretation Experimental observations and rheology of complex biological materials, including mucus, cell membranes, the cytoskeleton, and blood The motility of microorganisms in complex fluids and the dynamics of active suspensions Challenges and solut...

  17. Ultraviolet radiation and its biological effects

    International Nuclear Information System (INIS)

    Rames, J.; Bencko, V.

    1993-01-01

    In connexion with contamination of the atmosphere with freons, the interest is increasing in geophysical and health aspects of 'ozone holes' - the seasonal incidence of increased intensity of UV radiation. Its biological effects depend on the intensity of the radiation, the exposure time and the wavelength. There is a wide range of various sorts of damage, local as well as general. In addition to skin pigmentation and symptoms produced by an elevated histamine blood level, also changes are found which may have more serious and permanent consequences: changes in the number and structure of Langerhans islets, changes of the peripheral capillary walls, dimerization of pyrimidine and thymine in DNA. These changes demonstrably contribute to the development of skin malignancies. After exposure of the eye, changes in pigmentation are found, and depending on the dose, possibly also development of conjunctivitis or retinal damage. Recently the interaction of UV radiation with arsenic was investigated. On the other side, therapeutic effects of UV radiation combined with chemotherapy are used in dermatology, eg., for inhibition of contact sensitization. (author) 42 refs

  18. The effect of biological cohesion on current ripple development

    Science.gov (United States)

    Malarkey, Jonathan; Baas, Jaco H.; Hope, Julie

    2014-05-01

    Results are presented from laboratory experiments examining the role of biological cohesion, associated with Extra Polymeric Substances, on the development of current ripples. The results demonstrate the importance of biological cohesion compared to the effect of physical cohesion associated with clays in an otherwise sandy bed. FURTHER INFORMATION In fluvial and marine environments sediment transport is mainly dependent on the nature of the bed surface (rippled or flat) and the nature of cohesion in the bed. Cohesion can be either physical, as a result of the presence of clays, or biological as a result of the presence of organisms. In the case of the latter, biological cohesion occurs as a result of the presence of Extra Polymeric Substances (EPS) secreted by microorganisms. While it is known that EPS can dramatically increase the threshold of motion (Grant and Gust, 1987), comparatively little is known about the effect of EPS on ripple formation and development. The experiments described here seek to fill this gap. They also allow the effect of biological cohesion to be compared with that of physical cohesion from previous experiments (Baas et al., 2013). The experiments, which were conducted in a 10m flume at Bangor University, involved a current over a bed made of fine sand, with a median diameter of 0.148mm, and various amounts of xanthan gum, a proxy for naturally occurring EPS (Vardy et al., 2007). The hydrodynamic experimental conditions were matched very closely to those of Baas et al. (2013). The ripple dimensions were recorded through the glass side wall of the tank using time lapse photography. In the physical cohesion experiments of Baas et al. (2013) for clay contents up to 12%, the clay was very quickly winnowed out of the bed, leaving essentially clay-free ripples that developed at more or less the same rate as clean sand ripples. The resulting equilibrium ripples were essentially the same length as the clean sand ripples but reduced in height. By

  19. Biological effects of tritium and its behavior in the body. Ratio of biological effects (RBE)

    International Nuclear Information System (INIS)

    Takeda, Hiroshi

    1997-01-01

    Biological effects of radiation is known to depend not only on the radiation energy absorbed in the cells and the tissues of an organism, but also on ionization density. RBE, a biological effects ratio is used to correct the difference in absorbed dose due to the kind of nuclide. Determination of RBE has been carried out with end points of various biological effects as indicators for characterization of tritium effects. Recently, the tritium RBE was estimated from the indicators such as carcinogenesis, gene abnormalities, teratogenesis and gonadal abnormalities. The RBE values for HTO and 3 H-thymidine were in the range of 0.7-4.5 and 0.9-5.9. The varieties in RBE values were thought to be caused by the differences in the species or cell lines used, those in end points such as cell death, induction of mutagenesis and those in the kind of radiation as the control as well as the dose rate. Thus, there were various factors mediating RBE. (M.N.)

  20. E. Biological effects of radiation on man

    International Nuclear Information System (INIS)

    1976-01-01

    This report firstly summarises information on the biological hazards of radiation and their relation to radiation dose, and hence estimates the biological risks associated with nuclear power production. Secondly, it describes the basis and present status of radiation protection standards in the nuclear power industry

  1. Epigenesis by experience: Romantic empiricism and non-Kantian biology.

    Science.gov (United States)

    Goldstein, Amanda Jo

    2017-12-13

    Reconstructions of Romantic-era life science in general, and epigenesis in particular, frequently take the Kantian logic of autotelic "self-organization" as their primary reference point. I argue in this essay that the Kantian conceptual rubric hinders our historical and theoretical understanding of epigenesis, Romantic and otherwise. Neither a neutral gloss on epigenesis, nor separable from the epistemological deflation of biological knowledge that has received intensive scrutiny in the history and philosophy of science, Kant's heuristics of autonomous "self-organization" in the third Critique amount to the strategic capture of epigenesis from nature, for thought, in thought's critical transcendence of nature. This essay looks to Jean-Baptiste Lamarck and his English contemporary Erasmus Darwin to begin to reconstruct the rigorously materialist, naturalist, and empiricist theories of epigenesis (still) marginalized by Kantian argumentation. As theorists of environmental and social collaboration in the ontogeny of viable forms, Lamarck and Darwin illuminate features of our own epigenetic turn obscured by the rhetoric of "self-organization," allowing us to glimpse an alternative Romantic genealogy of the biological present.

  2. The late biological effects of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1978-06-15

    Full text: The principal objective of the symposium was to review the current status of understanding of the late biological effects of ionizing radiation from external and internal sources. A second objective was to critically evaluate information obtained from epidemiological studies of human population groups as well as from animal experimentation in order to provide a solid scientific basis upon which problems of current concern, such as radiation protection standards and risk-benefit analysis, could be deliberated. Eighty-one papers were presented in 10 sessions which covered epidemiological studies of late effects in human populations exposed to internal and/or external ionizing radiation; quantitative and qualitative data from animal experimentation of late effects; methodological problems and modern approaches; factors influencing susceptibility or expression of late radiation injury; comparative evaluation of late effects induced by radiation and other environmental pollutants, and problems of risk assessment. In addition, there were two evening sessions for free discussion of problems of interpreting animal data, and of the epidemiological studies of occupationally exposed populations. Reports on atomic bomb survivors showed that these epidemiological studies are providing dependable data, such as dose-related excess infant mortality. The reports also revealed the need for consensus in the method employed in the interpretation of data. That was also the case with studies on occupationally exposed populations at Hanford plant, where disparate results were presented on radiation-induced neoplasia among radiation workers. These data are, however, considered not so significant in relative terms when compared to risks involved in other industries. It was recommended that national registry systems for the dosimetry and medical records of radiation workers be established and co-ordinated internationally in order to facilitate reliable epidemiological

  3. Assessment of the biological effects of 'strange' radiation

    International Nuclear Information System (INIS)

    Pryakhin, E.A.; Tryapitsina, G.A.; Urutskoyev, L.I.; Akleyev, A.V.

    2006-01-01

    The results from studies of the effects produced by electrical explosions of foils made from super pure materials in water point to the emergence of new chemical elements. An additional finding was the discharge of 'strange' radiation accompanying the transformation of chemical elements. However, currently, the mechanism involved in the interaction between 'strange' radiation and a substance or a biological entity remains obscure. Therefore, the aim of the present research is to investigate the biological effects of the 'strange' radiation. Pilot studies were performed at the RECOM RRC 'Kurchatov Institute' in April-May of 2004. The animals used in the experiment were female mice of C57Bl/6 line aged 80 days with body weight 16-18 g. The animals were exposed to radiation discharged during explosions of Ti foils in water and aqueous solutions. The cages with animals were placed at 1 m from the epicenter of the explosion. Explosions were carried out on the 19. (3 explosions), 20. (4 explosions) and 22. (3 explosions) of April, 2004 (explosions No1373 - No1382, respectively). The animals were assigned to 4 experimental groups comprised of 17-20 mice per group. The animals received experimental exposure within 1, 2 and 3 days of the experiment. In total, the experimental groups were exposed to 3, 7 and 10 explosions, respectively. In order to identify the biological reactions, the following parameters were estimated: number of nucleated cells in the bone marrow, number of CFU in the spleen after additional gamma-irradiation (6 Gy), cell composition of the bone marrow, the rate of erythrocytes with the different level of maturation in the bone marrow, the rate of erythrocytes with the micronuclei in the bone marrow, the reaction of bone marrow cells to additional gamma-irradiation (2 Gy), number of leucocytes in the peripheral blood, and cell composition of the peripheral blood. The following conclusions were drawn from these studies: 1. 'strange' radiation resulting

  4. Accounting for biological effectiveness in radiological protection

    International Nuclear Information System (INIS)

    Dennis, J.A.

    1989-01-01

    Relative biological effectiveness (RBE) presents a practical problem to radiological protection when attempts are made to ensure that the assessed risks from different types of radiation and different modes of exposure to radiation are commensurate with one another. Unfortunately, the theoretical understanding of RBE is still in the stage of competing explanations and hypotheses. Furthermore, the division of the concept of dose equivalent into a set of concepts for risk assessment and another set for measurement and control has introduced conflicting requirements of a practical nature that are difficult to resolve. Many of those working in radiobiology and radiation protection have perceived the need to increase the quality factors for photon and neutron radiations. It may be more reasonable to change the quality factors for neutrons than for other radiations. The advantages and disadvantages of different methods for accommodating such changes within the dose-equivalent concepts are to be examined. The method of accommodating such a change that has the least practical disadvantages is to increase the quality factors for all secondary particles produced in tissue by neutron radiations by a constant factor. The only disadvantage would be the perception that the quality factors for these secondary particles were not treated in a consistent fashion for all types of ionising radiation. (author)

  5. Biologically based multistage modeling of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    William Hazelton; Suresh Moolgavkar; E. Georg Luebeck

    2005-08-30

    This past year we have made substantial progress in modeling the contribution of homeostatic regulation to low-dose radiation effects and carcinogenesis. We have worked to refine and apply our multistage carcinogenesis models to explicitly incorporate cell cycle states, simple and complex damage, checkpoint delay, slow and fast repair, differentiation, and apoptosis to study the effects of low-dose ionizing radiation in mouse intestinal crypts, as well as in other tissues. We have one paper accepted for publication in ''Advances in Space Research'', and another manuscript in preparation describing this work. I also wrote a chapter describing our combined cell-cycle and multistage carcinogenesis model that will be published in a book on stochastic carcinogenesis models edited by Wei-Yuan Tan. In addition, we organized and held a workshop on ''Biologically Based Modeling of Human Health Effects of Low dose Ionizing Radiation'', July 28-29, 2005 at Fred Hutchinson Cancer Research Center in Seattle, Washington. We had over 20 participants, including Mary Helen Barcellos-Hoff as keynote speaker, talks by most of the low-dose modelers in the DOE low-dose program, experimentalists including Les Redpath (and Mary Helen), Noelle Metting from DOE, and Tony Brooks. It appears that homeostatic regulation may be central to understanding low-dose radiation phenomena. The primary effects of ionizing radiation (IR) are cell killing, delayed cell cycling, and induction of mutations. However, homeostatic regulation causes cells that are killed or damaged by IR to eventually be replaced. Cells with an initiating mutation may have a replacement advantage, leading to clonal expansion of these initiated cells. Thus we have focused particularly on modeling effects that disturb homeostatic regulation as early steps in the carcinogenic process. There are two primary considerations that support our focus on homeostatic regulation. First, a number of

  6. Large-scale experience with biological treatment of contaminated soil

    International Nuclear Information System (INIS)

    Schulz-Berendt, V.; Poetzsch, E.

    1995-01-01

    The efficiency of biological methods for the cleanup of soil contaminated with total petroleum hydrocarbons (TPH) and polycyclic aromatic hydrocarbons (PAH) was demonstrated by a large-scale example in which 38,000 tons of TPH- and PAH-polluted soil was treated onsite with the TERRAFERM reg-sign degradation system to reach the target values of 300 mg/kg TPH and 5 mg/kg PAH. Detection of the ecotoxicological potential (Microtox reg-sign assay) showed a significant decrease during the remediation. Low concentrations of PAH in the ground were treated by an in situ technology. The in situ treatment was combined with mechanical measures (slurry wall) to prevent the contamination from dispersing from the site

  7. Biological applications of the Moessbauer effect

    International Nuclear Information System (INIS)

    Boulay, P.

    1968-12-01

    The applications of Moessbauer spectrometry in the fields of physics and chemistry have been increasing steadily since its discovery in 1958. Attempts have been made to find applications in biology. Two possibilities of investigation exist in this field: the study of mechanical or vibrational movements in certain animal organs, and the determination of the organic molecular structure in a biological context. An example is given of each of these possibilities. (author) [fr

  8. Experiment of decontamination of radioactive liquid by a biological method

    International Nuclear Information System (INIS)

    Wormser, G.

    1962-01-01

    The author reports experiments of treatment of radioactive liquid effluents by percolation on a bacterial bed like the one used for the treatment of sewer wastewaters. He also reports results obtained in other countries in terms of reduction of effluent radioactivity for various radioactive ions. The installation is described and results are presented in terms of variation of contamination of an effluent with respect to its recycling on a bacterial bed [fr

  9. Relative biological effectiveness of 160 MeV protons. II. Biological data and their interpretation in terms of microdosimetry

    International Nuclear Information System (INIS)

    Hall, E.J.; Kellerer, A.M.; Rossi, H.H.; Lam, Y.M.P.

    1978-01-01

    The radiobiological effectiveness of 160 MeV protons was measured relative to 60 Co γ rays using Chinese hamster cells cultured in vitro. Separate experiments were performed with cells irradiated in suspension, or attached to plastic tissue culture flasks. Proton irradiations were performed in the incident plateau of the depth dose profile and with the Bragg peak spread out to cover 10 cm. In all cases the relative biological effectiveness (RBE) for protons relative to gamma rays was 1.2 for doses in excess of about 200 rad. The attached cell experiments indicate an increasing RBE at low doses, which is consistent with the microdosimetric measurements

  10. Biology experiments at UNILAC. Reports from the biology user meeting, GSI, 3 October 1985

    International Nuclear Information System (INIS)

    1985-10-01

    On 3 Oct 1985, an internal Biology User Meeting of the groups working at GSI was arranged for the purpose of exchanging information and having discussions. It was found that the experimental data obtained so far are quite complex, and that the attempts at a theoretical treatment are still in a very early stage. To keep the discussion going, this report therefore presents the contributions of the various groups as far as these have been available. Most of the information was not in finished reports but in the form of diagrams and tables with explanations, sometimes even in the form of handwritten notes or sketches. Separate records are available for 13 contributions. (orig./MG) [de

  11. Biological effects of low-dose ionizing radiation exposure

    International Nuclear Information System (INIS)

    Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst

    2009-01-01

    The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

  12. A study on the ranges of low energy ions in biological samples and its mechanism of biological effects

    International Nuclear Information System (INIS)

    Lu Ting; Xie Liqing; Li Junping; Xia Ji

    1993-01-01

    The seeds of wheat and bean are irradiated by iron ion beam with energy 100 keV. The RBS spectra of the samples are observed and the ranges and distributions of the iron ions in the wheat and bean are calculated theoretically by means of Monte Carlo method. The results of theory and experiment are compared and the mechanism of biological effects induced by ion is discussed

  13. Modulation of mutagen-induced biological effects by inhibitors of DNA repair

    International Nuclear Information System (INIS)

    Natarajan, A.T.; Mullenders, L.F.H.; Zwanenburg, T.S.B.

    1986-01-01

    When lesions are induced in the DNA by mutagenic agents, they are subjected to cellular repair. Unrepaired and misrepaired lesions lead to biological effects, such as cell killing, point mutations and chromosomal alterations (aberrations and sister chromatid exchanges - SCEs). It is very difficult to directly correlate any particular type of lesion to a specific biological effect. However, in specific cases, this has been done. For example, short wave UV induced biological effects (cell killing, chromosomal alterations) result predominantly from induced cyclobutane dimers and by photoreactivation experiments, one can demonstrate that with the removal of dimers all types biological effects are diminished. In cases where many types of lesions are considered responsible for the observed biological effects other strategies have been employed to identify the possible lesion. The frequencies of induced chromosomal alterations and point mutations increase with the dose of the mutagen employed and an inhibition of DNA repair following treatment with the mutagen. Prevention of the cells from dividing following mutagen treatment allows them to repair premutational damage, thus reducing the biological effects induced. By comprehensive studies involving quantification of primary DNA lesions, their repair and biological effects will enable us to understand to some extent the complex processes involved in the manifestation of specific biological effects that follow the treatment of cells with mutagenic carcinogens

  14. Ecological aspects od electromagnetic irradiation effects of biological objects

    International Nuclear Information System (INIS)

    Volobuev, A.P.; Donnik, I.M.; Alekseenko, N.N.

    2005-01-01

    General description of electromagnetic field effects on biological objects depending on its frequency properties is stated in the paper. Basic principles of low frequency field effect (10 -1 -0 2 Hz) are detailed. General and specific regularities of biological objects response to a low frequency field on subcell, cell, and system levels were considered taking into account their functional state. (author)

  15. Studying of ion implantation effect on the biology in China

    International Nuclear Information System (INIS)

    Yu Zengliang

    1993-04-01

    Since low energy ion effect on the biology was observed, the ion implantation as a new mutagenic source has been widely used in improving crops and modifying microbes in China. The basic phenomenon of ion implantation effect on the biology and analytical results are reported, and the examples of its application and its further development are shown

  16. First biological experiments at a vertical proton beam

    Energy Technology Data Exchange (ETDEWEB)

    Distel, L; Distel, B; Roessner, B; Schwotzer, G; Sauer, R [Erlangen-Nuernberg Univ., Erlangen (Germany). Klinik fuer Strahlentherapie; Eyrich, W; Fritsch, M; Teufel, A [Erlangen-Nuernberg Univ., Erlangen (Germany). Physikalisches Inst.; Besserer, J; Boer, J de; Moosburger, M; Quicken, P [Muenchen Univ. (Germany). Sektion Physik

    1997-09-01

    At the tandem accelerator laboratories in Munich and Erlangen vertical beamlines were installed last year. The advantage of a vertical beamline is that cells can be irradiated in a medium at 37 C and with simultaneous gassing, therefore also in physiological conditions. First experiments were carried out at the accelerator in Munich with a proton energy of 25 MeV. Chinese Hamster cells B14 were irradiated in Petri dishes where the base was of 1 mm polystyrol or 2 {mu}m hostaphan foils. The cell survival was measured by the cell survival assay and the repopulation of the colonies by the total colony volume. A solution of DNA with protein was irradiated to study DNA double strand breaks by constant field gel electrophoresis and DNA protein crosslinks by the nitrocellulose filter assay. For cell survival, total colony volume and DNA double-strand breaks X-rays and protons gave corresponding results, while with protons, higher yields of DNA-protein crosslinks were observed than with X-rays. (orig.)

  17. First biological experiments at a vertical proton beam

    International Nuclear Information System (INIS)

    Distel, L.; Distel, B.; Roessner, B.; Schwotzer, G.; Sauer, R.; Eyrich, W.; Fritsch, M.; Teufel, A.; Besserer, J.; Boer, J. de; Moosburger, M.; Quicken, P.

    1997-01-01

    At the tandem accelerator laboratories in Munich and Erlangen vertical beamlines were installed last year. The advantage of a vertical beamline is that cells can be irradiated in a medium at 37 C and with simultaneous gassing, therefore also in physiological conditions. First experiments were carried out at the accelerator in Munich with a proton energy of 25 MeV. Chinese Hamster cells B14 were irradiated in Petri dishes where the base was of 1 mm polystyrol or 2 μm hostaphan foils. The cell survival was measured by the cell survival assay and the repopulation of the colonies by the total colony volume. A solution of DNA with protein was irradiated to study DNA double strand breaks by constant field gel electrophoresis and DNA protein crosslinks by the nitrocellulose filter assay. For cell survival, total colony volume and DNA double-strand breaks X-rays and protons gave corresponding results, while with protons, higher yields of DNA-protein crosslinks were observed than with X-rays. (orig.)

  18. Group processing in an undergraduate biology course for preservice teachers: Experiences and attitudes

    Science.gov (United States)

    Schellenberger, Lauren Brownback

    Group processing is a key principle of cooperative learning in which small groups discuss their strengths and weaknesses and set group goals or norms. However, group processing has not been well-studied at the post-secondary level or from a qualitative or mixed methods perspective. This mixed methods study uses a phenomenological framework to examine the experience of group processing for students in an undergraduate biology course for preservice teachers. The effect of group processing on students' attitudes toward future group work and group processing is also examined. Additionally, this research investigated preservice teachers' plans for incorporating group processing into future lessons. Students primarily experienced group processing as a time to reflect on past performance. Also, students experienced group processing as a time to increase communication among group members and become motivated for future group assignments. Three factors directly influenced students' experiences with group processing: (1) previous experience with group work, (2) instructor interaction, and (3) gender. Survey data indicated that group processing had a slight positive effect on students' attitudes toward future group work and group processing. Participants who were interviewed felt that group processing was an important part of group work and that it had increased their group's effectiveness as well as their ability to work effectively with other people. Participants held positive views on group work prior to engaging in group processing, and group processing did not alter their atittude toward group work. Preservice teachers who were interviewed planned to use group work and a modified group processing protocol in their future classrooms. They also felt that group processing had prepared them for their future professions by modeling effective collaboration and group skills. Based on this research, a new model for group processing has been created which includes extensive

  19. MOLNs: A CLOUD PLATFORM FOR INTERACTIVE, REPRODUCIBLE, AND SCALABLE SPATIAL STOCHASTIC COMPUTATIONAL EXPERIMENTS IN SYSTEMS BIOLOGY USING PyURDME.

    Science.gov (United States)

    Drawert, Brian; Trogdon, Michael; Toor, Salman; Petzold, Linda; Hellander, Andreas

    2016-01-01

    Computational experiments using spatial stochastic simulations have led to important new biological insights, but they require specialized tools and a complex software stack, as well as large and scalable compute and data analysis resources due to the large computational cost associated with Monte Carlo computational workflows. The complexity of setting up and managing a large-scale distributed computation environment to support productive and reproducible modeling can be prohibitive for practitioners in systems biology. This results in a barrier to the adoption of spatial stochastic simulation tools, effectively limiting the type of biological questions addressed by quantitative modeling. In this paper, we present PyURDME, a new, user-friendly spatial modeling and simulation package, and MOLNs, a cloud computing appliance for distributed simulation of stochastic reaction-diffusion models. MOLNs is based on IPython and provides an interactive programming platform for development of sharable and reproducible distributed parallel computational experiments.

  20. Experiences of mobility for people living with rheumatoid arthritis who are receiving biologic drug therapy: implications for podiatry services.

    Science.gov (United States)

    Sanders, Lucy; Donovan-Hall, Margaret; Borthwick, Alan; Bowen, Catherine J

    2017-01-01

    Despite significant advancements in new treatment modalities for rheumatoid arthritis with biological therapies, foot complications remain a disabling and common feature of the disease . In this study the aim was to explore and describe the personal experiences of people with rheumatoid arthritis in receipt of biologic treatments in a bid to understand the impact of this form of medication on their mobility. An interpretative phenomenological analysis (IPA) was undertaken to explore in depth the individual experience of rheumatoid disease through personal accounts of the patient journey spanning both 'before' and 'after' the instigation of biologic therapy. A purposive sampling strategy was adopted and in-depth semi structured interviews used to facilitate rich, detailed interview data exploring the lived experiences of individuals undertaking biological therapy and the changes to mobility experienced as a result. Thematic analysis was employed with an IPA framework to identify key meanings, and report patterns within the data. Five people with rheumatoid arthritis participated in the study. The mean disease duration was 20.2 years (range: 6 -32) and all were being treated with biologic therapies. Four key themes emerged from the data: 1) Life before biologic treatment, depicted in accounts as a negative experience characterised by painful and disabling symptoms and feelings of hopelessness. 2) Life with biologic treatment, often experienced as a life changing transition, restoring function and mobility and offering renewed hope. 3) Sense of self, in which the impact of rheumatoid disease and the subsequent changes arising from biologic therapy reveal a profound impact on feelings of personal identity both pre and post biologic therapy; an effect of footwear on self-image emerges as a dominant sub theme; 4) Unmet footcare needs were evident in the patient narrative, where the unrelenting if diminished impact of foot pain on mobility was viewed in the context of

  1. The Importance of Pupils' Interests and Out-of-School Experiences in Planning Biology Lessons

    Science.gov (United States)

    Uitto, Anna; Juuti, Kalle; Lavonen, Jari; Meisalo, Veijo

    2008-01-01

    How to make learning more interesting is a basic challenge for school education. In this Finnish study, the international ROSE questionnaire was used to survey, during spring of 2003, the relationship between interest in biology and out-of-school experiences for 3626 ninth-grade pupils. Interest and experience factors were extracted by using the…

  2. Learning More Effectively from Experience

    Directory of Open Access Journals (Sweden)

    Ioan Fazey

    2005-12-01

    Full Text Available Developing the capacity for individuals to learn effectively from their experiences is an important part of building the knowledge and skills in organizations to do good adaptive management. This paper reviews some of the research from cognitive psychology and phenomenography to present a way of thinking about learning to assist individuals to make better use of their personal experiences to develop understanding of environmental systems. We suggest that adaptive expertise (an individual's ability to deal flexibly with new situations is particularly relevant for environmental researchers and practitioners. To develop adaptive expertise, individuals need to: (1 vary and reflect on their experiences and become adept at seeking out and taking different perspectives; and (2 become proficient at making balanced judgements about how or if an experience will change their current perspective or working representation of a social, economic, and biophysical system by applying principles of "good thinking." Such principles include those that assist individuals to be open to the possibility of changing their current way of thinking (e.g., the disposition to be adventurous and those that reduce the likelihood of making erroneous interpretations (e.g., the disposition to be intellectually careful. An example of applying some of the principles to assist individuals develop their understanding of a dynamically complex wetland system (the Macquarie Marshes in Australia is provided. The broader implications of individual learning are also discussed in relation to organizational learning, the role of experiential knowledge for conservation, and for achieving greater awareness of the need for ecologically sustainable activity.

  3. Developing Effective Undergraduate Research Experience

    Science.gov (United States)

    Evans, Michael; Ilie, Carolina C.

    2011-03-01

    Undergraduate research is a valuable educational tool for students pursuing a degree in physics, but these experiences can become problematic and ineffective if not handled properly. Undergraduate research should be planned as an immersive learning experience in which the student has the opportunity to develop his/her skills in accordance with their interests. Effective undergraduate research experiences are marked by clear, measurable objectives and frequent student-professor collaboration. These objectives should reflect the long and short-term goals of the individual undergraduates, with a heightened focus on developing research skills for future use. 1. Seymour, E., Hunter, A.-B., Laursen, S. L. and DeAntoni, T. (2004), ``Establishing the benefits of research experiences for undergraduates in the sciences: First findings from a three-year study''. Science Education, 88: 493--534. 2. Behar-Horenstein, Linda S., Johnson, Melissa L. ``Enticing Students to Enter Into Undergraduate Research: The Instrumentality of an Undergraduate Course.'' Journal of College Science Teaching 39.3 (2010): 62-70.

  4. Survey of cell biology experiments in reduced gravity

    Science.gov (United States)

    Taylor, G. R.

    1977-01-01

    The effects of spaceflight on terrestrial cell systems are discussed. With some important exceptions, static cell systems carried aboard U.S.A. and U.S.S.R. space flights have failed to reveal space related anomalies. Some sophisticated devices which were developed for viewing directly, or continuously recording, the growth of cells, tissue cultures and eggs in flight, are described and the results summarized. The unique presence of high energy, multicharged (HZE) particles and full-range ultraviolet irradiation in space prompted evaluation of the response of single cells to these factors. Summary results and general conclusions are presented. Potential areas of research in future space flights are identified.

  5. Component effects in mixture experiments

    International Nuclear Information System (INIS)

    Piepel, G.F.

    1980-01-01

    In a mixture experiment, the response to a mixture of q components is a function of the proportions x 1 , x 2 , ..., x/sub q/ of components in the mixture. Experimental regions for mixture experiments are often defined by constraints on the proportions of the components forming the mixture. The usual (orthogonal direction) definition of a factor effect does not apply because of the dependence imposed by the mixture restriction, /sup q/Σ/sub i=1/ x/sub i/ = 1. A direction within the experimental region in which to compute a mixture component effect is presented and compared to previously suggested directions. This new direction has none of the inadequacies or errors of previous suggestions while having a more meaningful interpretation. The distinction between partial and total effects is made. The uses of partial and total effects (computed using the new direction) in modification and interpretation of mixture response prediction equations are considered. The suggestions of the paper are illustrated in an example from a glass development study in a waste vitrification program. 5 figures, 3 tables

  6. Immunomodulatory Effects of Macrolide Antibiotics - Part 1 : Biological Mechanisms

    NARCIS (Netherlands)

    Altenburg, J.; de Graaff, C. S.; van der Werf, T. S.; Boersma, W. G.

    2011-01-01

    Macrolide antibiotics are well known for their antibacterial and anti-inflammatory properties. This article provides an overview of the biological mechanisms through which macrolides exert this 'double effect'. Their antibacterial effect consists of the inhibition of bacterial protein synthesis,

  7. Late biological effects from internal and external exposure

    International Nuclear Information System (INIS)

    Adams, W.H.

    1985-01-01

    Information on late biological effects of radiation was obtained from the long-term medical followup of a small population of Marshallese accidentally exposed to radioactive fallout from a thermonuclear test in 1954. Endocrine data are compatible with a sequence of nonstochastic radiation effects. The ingestion of radioisotopes of iodine produced clinical thyroid hypofunction in children, biochemical evidence of thyroid dysfunction in some adults, thyroid adenomatous module formation, and, as a possible indirect effect of thyroid damage, at least two cases of pituitary adenoma. In contrast, the only evidence of a stochastic effect has been a real increase in thyroid cancers among the more highly exposed people of Rongelap, none of whom have evidence of residual disease. While three nonthyroidal cancers which are known to be inducible in humans by external irradiation have been documented in the exposed population, three similar cancers have occurred in an unexposed comparison population of Marshallese. Nonstochastic effects of radiation exposure may be common but subtle. In the Marshallese experience the morbidity of delayed nonstochastic effects far exceeds that of the stochastic. 20 refs., 5 figs., 1 tab

  8. Designing Effective Undergraduate Research Experiences

    Science.gov (United States)

    Severson, S.

    2010-12-01

    I present a model for designing student research internships that is informed by the best practices of the Center for Adaptive Optics (CfAO) Professional Development Program. The dual strands of the CfAO education program include: the preparation of early-career scientists and engineers in effective teaching; and changing the learning experiences of students (e.g., undergraduate interns) through inquiry-based "teaching laboratories." This paper will focus on the carry-over of these ideas into the design of laboratory research internships such as the CfAO Mainland internship program as well as NSF REU (Research Experiences for Undergraduates) and senior-thesis or "capstone" research programs. Key ideas in maximizing student learning outcomes and generating productive research during internships include: defining explicit content, scientific process, and attitudinal goals for the project; assessment of student prior knowledge and experience, then following up with formative assessment throughout the project; setting reasonable goals with timetables and addressing motivation; and giving students ownership of the research by implementing aspects of the inquiry process within the internship.

  9. Effectiveness of a biological control agent Palexorista gilvoides in ...

    African Journals Online (AJOL)

    ACSS

    Effectiveness of a biological control agent Palexorista gilvoides in controlling Gonometa podorcarpi in conifer ... gilvoides as a potential biological control agent for G. podocarpi. Field and laboratory studies further established that P. .... version for windows (SPSS, 2002). Results. Gonometa podocarpi was present in.

  10. A reverse engineering approach to optimize experiments for the construction of biological regulatory networks.

    Science.gov (United States)

    Zhang, Xiaomeng; Shao, Bin; Wu, Yangle; Qi, Ouyang

    2013-01-01

    One of the major objectives in systems biology is to understand the relation between the topological structures and the dynamics of biological regulatory networks. In this context, various mathematical tools have been developed to deduct structures of regulatory networks from microarray expression data. In general, from a single data set, one cannot deduct the whole network structure; additional expression data are usually needed. Thus how to design a microarray expression experiment in order to get the most information is a practical problem in systems biology. Here we propose three methods, namely, maximum distance method, trajectory entropy method, and sampling method, to derive the optimal initial conditions for experiments. The performance of these methods is tested and evaluated in three well-known regulatory networks (budding yeast cell cycle, fission yeast cell cycle, and E. coli. SOS network). Based on the evaluation, we propose an efficient strategy for the design of microarray expression experiments.

  11. Background study of absorbed dose in biological experiments at the Modane Underground Laboratory

    Directory of Open Access Journals (Sweden)

    Lampe Nathanael

    2016-01-01

    Full Text Available Aiming to explore how biological systems respond to ultra-low background environ-ments, we report here our background studies for biological experiments in the Modane Under-ground Laboratory. We find that the minimum radioactive background for biology experiments is limited by the potassium content of the biological sample itself, coming from its nutritive me-dium, which we find in our experimental set-up to be 26 nGy hr-1. Compared to our reference radiation environment in Clermont-Ferrand, biological experiments can be conducted in the Modane laboratory with a radiation background 8.2 times lower than the reference above-ground level. As the radiation background may be further reduced by using different nutritive media, we also provide measurements of the potassium concentration by gamma spectroscopy of yeast extract (63.3±1.2 mg g-1 and tryptone (2.5±0.2 mg g-1 in order to guide media selection in future experiments.

  12. Topical Day on Biological Effects of Radiation

    Energy Technology Data Exchange (ETDEWEB)

    Baatout, S.; Jacquet, P.

    1997-05-15

    The topical day has been focussed on the potential effects of ionizing radiation on human health. A general overview on molecular and biophysical aspects of radiation, its effects on cells and organisms, and the contribution of radiobiology to radiation protection and risk assessment is given. The genetic effects of radiation and its effects on the developing organism, the effects of radiation on the cell cycle and the mechanisms of radiation induced apoptosis were also discussed.

  13. Topical Day on Biological Effects of Radiation

    International Nuclear Information System (INIS)

    Baatout, S.; Jacquet, P.

    1997-01-01

    The topical day has been focussed on the potential effects of ionizing radiation on human health. A general overview on molecular and biophysical aspects of radiation, its effects on cells and organisms, and the contribution of radiobiology to radiation protection and risk assessment is given. The genetic effects of radiation and its effects on the developing organism, the effects of radiation on the cell cycle and the mechanisms of radiation induced apoptosis were also discussed

  14. Is Reintroduction Biology an Effective Applied Science?

    Science.gov (United States)

    Taylor, Gemma; Canessa, Stefano; Clarke, Rohan H; Ingwersen, Dean; Armstrong, Doug P; Seddon, Philip J; Ewen, John G

    2017-11-01

    Reintroduction biology is a field of scientific research that aims to inform translocations of endangered species. We review two decades of published literature to evaluate whether reintroduction science is evolving in its decision-support role, as called for by advocates of evidence-based conservation. Reintroduction research increasingly addresses a priori hypotheses, but remains largely focused on short-term population establishment. Similarly, studies that directly assist decisions by explicitly comparing alternative management actions remain a minority. A small set of case studies demonstrate full integration of research in the reintroduction decision process. We encourage the use of tools that embed research in decision-making, particularly the explicit consideration of multiple management alternatives because this is the crux of any management decisions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Solar ultraviolet radiation effects on biological systems

    International Nuclear Information System (INIS)

    Diffey, B.L.

    1991-01-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK)

  16. Solar ultraviolet radiation effects on biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Diffey, B.L. (Dryburn Hospital, Durham (UK). Regional Medical Physics Dept.)

    1991-03-01

    This extensive review discusses the topic under the following headings: ultraviolet climatology, molecular and cellular ultraviolet photobiology (absorption, photoproducts, repair), effects of solar UVR on aquatic life (phyto and zooplankton), plants and humans. The section on human effects includes tanning, photo-aging, non-melanoma and melanoma skin cancers and the effects of solar UVR on the eye. (UK).

  17. Experience Reverses the Red Effect among Chinese Stockbrokers

    OpenAIRE

    Zhang, Tengxiao; Han, Buxin

    2014-01-01

    Recent research has shown that the color red influences psychological functioning. Red is hypothesized to be linked to aggression and danger in evolution, and these links are enhanced by culture-specific uses of red. Thus, color meanings are thought to be grounded in biologically based proclivities and learned associations. However, to date, there has been no direct evidence for the influence of experience on the red effect. This study focused on whether experience could change the psychologi...

  18. Effects of marine reserves on the reproductive biology and ...

    African Journals Online (AJOL)

    Effects of marine reserves on the reproductive biology and recruitment rates of commonly and rarely exploited limpets. ... For recruitment, we hypothesised that if recruits are attracted to adults or survive better ... AJOL African Journals Online.

  19. Iron diminishes the in vitro biological effect of vanadium.

    Science.gov (United States)

    Mechanistic pathways underlying inflammatory injury following exposures to vanadium-containing compounds are not defined. We tested the postulate that the in vitro biological effect of vanadium results from its impact on iron homeostasis. Human bronchial epithelial (HBE) cells ex...

  20. Effect of Biological and Chemical Ripening Agents on the Nutritional ...

    African Journals Online (AJOL)

    Effect of Biological and Chemical Ripening Agents on the Nutritional and Metal Composition of Banana ( Musa spp ) ... Journal Home > Vol 18, No 2 (2014) > ... curcas leaf were used and compared with a control with no ripening agent.

  1. Biological effect of ultrasoft x-ray, 1

    International Nuclear Information System (INIS)

    Narita, Noboru

    1985-01-01

    Biological effect on Escherichia coli by ultrasoft X-ray have been studied by comparing with that by uv light (2537 A) and by soft X-ray (40 kVp, 5 mA). Ultrasoft X-ray is aluminium characteristic X-ray (about 1.5 keV) produced by low energy electron collision on aluminium foil target and is obtained from Lea-type transmission target discharge tube. Escherichia coli used here are AB1157, AB1886 (uvrA6), JC1569 (recA), AB2470 (recB) and AB2480 (uvr rec) for inactivation experiment and WP2, WP2uvrA, WP2pKM101 and WP2uvrApKM101 for mutation induction experiment. These strains are all irradiated in buffer. Results obtained are summerized as follows : (i) inactivation by ultrasoft X-ray is located between ones by uv light and by soft X-ray, or ultrasoft X-ray gives a lethal damage that uvrA6 gene seems to contribute, and (ii) ultrasoft X-ray does not show the remarkable mutation induction like that induced by low dose irradiation of uv light or soft X-ray. (author)

  2. Distinguishing between "function" and "effect" in genome biology.

    Science.gov (United States)

    Doolittle, W Ford; Brunet, Tyler D P; Linquist, Stefan; Gregory, T Ryan

    2014-05-09

    Much confusion in genome biology results from conflation of possible meanings of the word "function." We suggest that, in this connection, attention should be paid to evolutionary biologists and philosophers who have previously dealt with this problem. We need only decide that although all genomic structures have effects, only some of them should be said to have functions. Although it will very often be difficult or impossible to establish function (strictly defined), it should not automatically be assumed. We enjoin genomicists in particular to pay greater attention to parsing biological effects. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  3. Biological effects induced by low amounts of nuclear fission products

    International Nuclear Information System (INIS)

    Vasilenko, I.Ya.; Shishkin, V.F.; Khudyakova, N.V.

    1991-01-01

    The review deals with the problem of biological hazard of low radiation doses for animals and human beings taking into the danger of internal and external irradiation by nuclear fission products under conditions of enhancing anthropogenic radiation contamination of biosphere. An attention is paid to the estimation of life span carcinogenesis, genetic and delayed effects. A conclusion is made on a necessity of multiaspect investigation of biological importance of low radiation doses taking into account modifying effects of other environmental factors

  4. Current research in Canada on biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Marko, A.M.

    1980-05-01

    A survey of current research in Canada on the biological effects of ionizing radiation has been compiled. The list of projects has been classified according to structure (organizational state of the test system) as well as according to the type of effects. Using several assumptions, ballpark estimates of expenditures on these activities have been made. Agencies funding these research activities have been tabulated and the break-down of research in government laboratories and in academic institutions has been designated. Wherever possible, comparisons have been made outlining differences or similarities that exist between the United States and Canada concerning biological radiation research. It has been concluded that relevant research in this area in Canada is inadequate. Wherever possible, strengths and weaknesses in radiation biology programs have been indicated. The most promising course for Canada to follow is to support adequately fundamental studies of the biological effects of radiation. (auth)

  5. Biological effects of water reservoir radioactive contamination

    International Nuclear Information System (INIS)

    Mashneva, N.I.

    1983-01-01

    Radiation damage to fresh water fishes at early stages of ontogenesis is revealed only during the spawn incubation in a solution with 10 -5 to 10 -3 Cu/l radioactivity and at relatively high dosages exceeding 500-1000 rad. Damaging effect of a fission product mixture of 9, 30 and 100 day age as well as of several separate radionuclides on embryogenesis of freshwater fishes depends mainly on fish species, concentration, toxicity, chemical form of radionuclides in the residence medium, on peculiarities of metabolism between the aqueous medium and an organism, stage of the embryo development by the moment of radiation effect and duration of this effect

  6. Students' Interest in Biology and Their Out-of-School Experiences

    Science.gov (United States)

    Uitto, Anna; Juuti, Kalle; Lavonen, Jari; Meisalo, Veijo

    2006-01-01

    Interest in biology and the out-of-school experiences of Finnish secondary school pupils (n = 3626, median age 15) were surveyed in the spring of 2003 using the international ROSE questionnaire. Likert-scaled items were categorised with an explorative factor analysis. The scores of eight interest-context factors and seven out-of-school experience…

  7. Variability of Biological Degradation of Aromatic Hydrocarbons in an Aerobic Aquifer Determined by Laboratory Batch Experiments

    DEFF Research Database (Denmark)

    Nielsen, Per Henning; Christensen, Thomas Højlund

    1994-01-01

    The biological aerobic degradation of 7 aromatic hydrocarbons (benzene, toluene, o-xylene, p-dichlorobenzene, o-dichlorobenzene, naphthalene and biphenyl) was studied for 149 days in replicate laboratory batch experiments with groundwater and sediment from 8 localities representing a 15 m × 30 m...

  8. Gaining a Child: Comparing the Experiences of Biological Parents, Adoptive Parents, and Stepparents

    Science.gov (United States)

    Ceballo, Rosario; Lansford, Jennifer E.; Abbey, Antonia; Stewart, Abigail J.

    2004-01-01

    This study compares the experience of gaining a child through birth, adoption, or marriage, extending the focus of investigation beyond biological parenthood and the transition made by first-time parents. Using a subsample from the National Survey of Families and Households N=204, we compared reasons for having children, parental well-being,…

  9. Biological effects due to weak magnetic fields on plants

    Science.gov (United States)

    Belyavskaya, N.

    In the evolution process, living organisms have experienced the action of the Earth's magnetic field (MF) that is a natural component of our environment. It is known that a galactic MF induction does not exceed 0.1 nT, since investigations of weak magnetic field (WMF) effects on biological systems have attracted attention of biologists due to planning long-term space flights to other planets where the magnetizing force is near 10-5 Oe. However, the role of WMF and its influence on organisms' functioning are still insufficiently investigated. A large number of experiments with seedlings of different plant species placed in WMF has found that the growth of their primary roots is inhibited during the early terms of germination in comparison with control. The proliferation activity and cell reproduction are reduced in meristem of plant roots under WMF application. The prolongation of total cell reproductive cycle is registered due to the expansion of G phase in1 different plant species as well as of G phase in flax and lentil roots along with2 relative stability of time parameters of other phases of cell cycle. In plant cells exposed to WMF, the decrease in functional activity of genome at early prereplicate period is shown. WMF causes the intensification in the processes of proteins' synthesis and break-up in plant roots. Qualitative and quantitative changes in protein spectrum in growing and differentiated cells of plant roots exposed to WMF are revealed. At ultrastructural level, there are observed such ultrastructural peculiarities as changes in distribution of condensed chromatin and nucleolus compactization in nuclei, noticeable accumulation of lipid bodies, development of a lytic compartment (vacuoles, cytosegresomes and paramural bodies), and reduction of phytoferritin in plastids in meristem cells of pea roots exposed to WMF. Mitochondria are the most sensitive organelle to WMF application: their size and relative volume in cells increase, matrix is electron

  10. Biological effects and hazards of radiation exposure

    International Nuclear Information System (INIS)

    Boas, J.F.; Solomon, S.B.

    1990-01-01

    Radiation induced carcinogenesis and mutagenesis form the main risk to health from exposure to low levels of radiation. This risk effects can be at least qualitatively understood by considering the effects of radiation on cell DNA. Whilst exposure to high levels of radiation results in a number of identifiable effects, exposure to low levels of radiation may result in effects which only manifest themselves after many years. Risk estimates for low levels of radiation have been derived on the basis of a number of assumptions. In the case of uranium mine workers a major hazard arises from the inhalation of radon daughters. Whilst the correlation between radon daughter exposure and lung cancer incidence is well established, the numerical value of the risk factor is the subject of controversy. ICRP 50 gives a value of 10 cases per 10 6 person-years at risk per WLM (range 5-15 x 10 -6 PYR -1 WLM -1 ). The effect of smoking on lung cancer incidence rates amongst miners is also controversial. Nevertheless, smoking by miners should be discouraged

  11. On the mechanism of the biological effect of ionizing radiation

    International Nuclear Information System (INIS)

    Margulis, M.A.; Margulis, I.M.

    2005-01-01

    The mechanisms of the biological effects of ionizing radiation (IR) and ultrasound (US) were considered. The current views on the nature of toxicity of IR, which is usually assigned to the formation of radicals in living tissues and to the straight-line collision of an ionizing particle with the DNA molecule, were analyzed. It was established that the amount of radicals formed in biological tissues in conditions of ultrasonically induced cavitation can be as large as that for IR; however, the biological effect of US is much softer as compared to IR. It was shown that the contribution of the indirect mechanism to the total biological effect of IR can be estimated by comparing US and IR in their chemical action; the contribution of the indirect mechanism to the biological effect of IR was found to be negligibly small. An alternative mechanism was proposed to explain the biological effect of IR. In accordance with the proposed model, IR with a high linear energy transfer (LET) value breaks through cell walls and biological membranes and causes damage to them, such that the cell can lose its regenerative capacity. Moreover, high-energy heavy ionizing particles perforate cytoplasm to form channels. Ionizing radiation with a low LET value (γ- and X-rays) causes multiple damages to biological membranes. Ionizing particles can also cause damages to membranes of mitochondria thus affecting the mechanism of cellular respiration, which will cause neoplastic diseases. The straight-line collision of an ionizing particle with a DNA molecule was found to be 5-7 orders of magnitude less probable as compared to the collision with a wall or membrane. It was shown that multiple perforations of cell walls and damages to membranes are characteristic only of ionizing particles, which have sufficiently long tracks, and do not occur upon exposure to ultrasonic waves, microwaves, UV radiation, and magnetic fields [ru

  12. Biological Effects of Individual Alpha Particles

    International Nuclear Information System (INIS)

    L. A. Braby; R. R. Ford

    2002-01-01

    In order to provide quantitative data on the mechanisms of intercellular communication leading to bystander effects in irradiated cell populations, a positive ion microbeam irradiation system was set up at Texas A and M University and the rate at which photobleached and active fluorescent molecules are exchanged between irradiated and unirradiated cells was studied. AG1522 human fibroblast cells were chosen as one of the lines in this study because they had been shown to be proficient at bystander effects, and because they exhibited scrape loading response and lindane inhibition of effects which suggest that gap junction communication was involved. Surprisingly, detailed measurements of recovery from photobleaching suggested that gap junction communication did not occur in these cells. More detailed studies with gap junction inhibitors and with immunohistochemistry assays for gap junctions seem to confirm that these cells do not communicate in this way. A cell line which does communicate by gap junctions, Clone 9, shows no change in communication rates before and after irradiation. Other techniques, such as assessment of nuclear cross section were developed to determine if bystander effects alter cell progression through the cell cycle and the growth of individual cells

  13. Biological effects of fruit and vegetables

    DEFF Research Database (Denmark)

    Dragsted, L. O.; Krath, B.; Ravn-Haren, Gitte

    2006-01-01

    A strong and persistent effect of plant-derived foods on the prevention of lifestyle diseases has emerged from observational studies. Several groups of constituents in plants have been identified as potentially health promoting in animal studies, including cholesterol-lowering factors, antioxidan...

  14. Genelab: Scientific Partnerships and an Open-Access Database to Maximize Usage of Omics Data from Space Biology Experiments

    Science.gov (United States)

    Reinsch, S. S.; Galazka, J..; Berrios, D. C; Chakravarty, K.; Fogle, H.; Lai, S.; Bokyo, V.; Timucin, L. R.; Tran, P.; Skidmore, M.

    2016-01-01

    NASA's mission includes expanding our understanding of biological systems to improve life on Earth and to enable long-duration human exploration of space. The GeneLab Data System (GLDS) is NASA's premier open-access omics data platform for biological experiments. GLDS houses standards-compliant, high-throughput sequencing and other omics data from spaceflight-relevant experiments. The GeneLab project at NASA-Ames Research Center is developing the database, and also partnering with spaceflight projects through sharing or augmentation of experiment samples to expand omics analyses on precious spaceflight samples. The partnerships ensure that the maximum amount of data is garnered from spaceflight experiments and made publically available as rapidly as possible via the GLDS. GLDS Version 1.0, went online in April 2015. Software updates and new data releases occur at least quarterly. As of October 2016, the GLDS contains 80 datasets and has search and download capabilities. Version 2.0 is slated for release in September of 2017 and will have expanded, integrated search capabilities leveraging other public omics databases (NCBI GEO, PRIDE, MG-RAST). Future versions in this multi-phase project will provide a collaborative platform for omics data analysis. Data from experiments that explore the biological effects of the spaceflight environment on a wide variety of model organisms are housed in the GLDS including data from rodents, invertebrates, plants and microbes. Human datasets are currently limited to those with anonymized data (e.g., from cultured cell lines). GeneLab ensures prompt release and open access to high-throughput genomics, transcriptomics, proteomics, and metabolomics data from spaceflight and ground-based simulations of microgravity, radiation or other space environment factors. The data are meticulously curated to assure that accurate experimental and sample processing metadata are included with each data set. GLDS download volumes indicate strong

  15. Historical parallels of biological space experiments from Soyuz, Salyut and Mir to Shenzhou flights

    Science.gov (United States)

    Nechitailo, Galina S.; Kondyurin, Alexey

    2016-07-01

    Human exploitation of space is a great achievement of our civilization. After the first space flights a development of artificial biological environment in space systems is a second big step. First successful biological experiments on a board of space station were performed on Salyut and Mir stations in 70-90th of last century such as - first long time cultivation of plants in space (wheat, linen, lettuce, crepis); - first flowers in space (Arabidopsis); - first harvesting of seeds in space (Arabidopsis); - first harvesting of roots (radish); - first full life cycle from seeds to seeds in space (wheat), Guinness recorded; - first tissue culture experiments (Panax ginseng L, Crocus sativus L, Stevia rebaundiana B; - first tree growing in space for 2 years (Limonia acidissima), Guinness recorded. As a new wave, the modern experiments on a board of Shenzhou Chinese space ships are performed with plants and tissue culture. The space flight experiments are now focused on applications of the space biology results to Earth technologies. In particular, the tomato seeds exposed 6 years in space are used in pharmacy industry in more then 10 pharmaceutical products. Tissue culture experiments are performed on the board of Shenzhou spaceship for creation of new bioproducts including Space Panax ginseng, Space Spirulina, Space Stetatin, Space Tomato and others products with unique properties. Space investments come back.

  16. Tracer tests and image analysis of biological clogging in a two-dimentsional sandbox experiment

    DEFF Research Database (Denmark)

    Kildsgaard, J.; Engesgaard, Peter Knudegaard

    2002-01-01

    A two-dimensional flow experiment on biological clogging was carried out by biostimulating a sandbox packed with sand inoculated with bacteria. Biostimulation. consisted of continuously injecting nutrients (acetate and nitrate). Clogging was visualized by frequently carrying out colored tracer...... experiments using Brilliant Blue. The tracer experiments were recorded with a digital camera and converted to concentration maps using an image-analysis method that revealed in detail the complex spreading pattern surrounding clogged areas. Clogging resulted in a finger-like spreading of the tracer around...

  17. Biological effects of fruit and vegetables.

    Science.gov (United States)

    Dragsted, Lars O; Krath, Britta; Ravn-Haren, Gitte; Vogel, Ulla B; Vinggaard, Anne Marie; Bo Jensen, Per; Loft, Steffen; Rasmussen, Salka E; Sandstrom, The late BrittMarie; Pedersen, Anette

    2006-02-01

    A strong and persistent effect of plant-derived foods on the prevention of lifestyle diseases has emerged from observational studies. Several groups of constituents in plants have been identified as potentially health promoting in animal studies, including cholesterol-lowering factors, antioxidants, enzyme inducers, apoptosis inducers etc. In human intervention studies the dose levels achieved tend to be lower than the levels found to be effective in animals and sampling from target organs is often not possible. A controlled dietary human intervention study was performed with forty-three volunteers, providing 600 g fruit and vegetables/d or in the controls a carbohydrate-rich drink to balance energy intake. Surrogate markers of oxidative damage to DNA, protein and lipids, enzymic defence and lipid metabolism were determined in blood and urine. It was found that a high intake of fruit and vegetables tends to increase the stability of lipids towards oxidative damage. Markers of oxidative enzymes indicate a steady increase in glutathione peroxidase (GPX1) activity in erythrocytes during intervention with fruit and vegetables but there is no effect on GPX1 transcription levels in leucocytes. No change occurs in glutathione-conjugating or -reducing enzyme activities in erythrocytes or plasma, and there are no effects on the transcription of genes involved in phase 2 enzyme induction or DNA repair in leucocytes. Fruit and vegetable intake decreases the level of total cholesterol and LDL-cholesterol, but does not affect sex hormones. In conclusion, it has been shown that total cholesterol and LDL-cholesterol, markers of peripheral lipid oxidation, and erythrocyte GPX1 activity are affected by high intakes of fruit and vegetables. This finding provides support for a protective role of dietary fruit and vegetables against CVD.

  18. The beginning of Space Life Science in China exploration rockets for biological experiment during 1960's

    Science.gov (United States)

    Jiang, Peidong; Zhang, Jingxue

    The first step of space biological experiment in China was a set of five exploration rockets launched during 1964 to 1966, by Shanghai Institute of Machine and Electricity, and Institute of Biophysics of The Chinese Academy of Sciences. Three T-7AS1rockets for rats, mice and other samples in a biological cabin were launched and recovered safely in July of 1964 and June of 1965. Two T-7AS2rockets for dog, rats, mice and other samples in a biological cabin were launched and recovered safely in July of 1966. Institute of Biophysics in charged of the general design of biological experiments, telemetry of physiological parameters, and selection and training of experiment animals. The samples on-board were: rats, mice, dogs, and test tubes with fruit fly, enzyme, bacteria, E. Coli., lysozyme, bacteriaphage, RNAase, DNAase, crystals of enzyme, etc. Physiological, biochemical, bacte-riological, immunological, genetic, histochemical studies had been conducted, in cellular and sub cellular level. The postures of rat and dog were monitored during flight and under weight-lessness. Physiological parameters of ECG, blood pressure, respiration rate, body temperature were recorded. A dog named"Xiao Bao"was flight in 1966 with video monitor, life support system and conditioned reflex equipment. It flighted for more than 20 minutes and about 70km high. After 40 years, the experimental data recorded of its four physiological parameters during the flight process was reviewed. The change of 4 parameters during various phase of total flight process were compared, analyzed and discussed.

  19. Nanosilver – Harmful effects of biological activity

    Directory of Open Access Journals (Sweden)

    Anna Maria Świdwińska-Gajewska

    2014-12-01

    Full Text Available Nanosilver, also identified as colloidal silver, has been known and used for ages to combat diseases or prolong food freshness. It usually occurs in the form of a suspension consisting of particles of size < 100 nm. Due to its specific properties, silver nanoparticles are used in many technologies to produce medical devices, textiles, conductive materials or photovoltaic cells. The growing popularity of nanosilver applications increases the number of people occupationally exposed to this substance. Potential exposure routes for silver nanoparticles are through dermal, oral and inhalation pathways. Silver nanoparticles may be absorbed through the lungs, intestine, and through the skin into circulation and thus may reach such organs as the liver, kidney, spleen, brain, heart and testes. Nanosilver may cause mild eyes and skin irritations. It can also act as a mild skin allergen. Inhalation of silver nanoparticles mainly affects the lungs and liver. It has been demonstrated that silver nanoparticles may be genotoxic to mammalian cells. There are some alarming reports on the adverse effects of silver nanoparticles on reproduction of experimental animals. Exposure to silver nanoparticles may exert a neurotoxic effect and affect cognitive functions, causing the impairment of short-term and working memory. Maximum admissible concentration (MAC for the inhalable fraction of silver of 0.05 mg/m3 is currently binding in Poland. In light of toxicological studies of silver nanoparticles it seems reasonable to update the hygiene standards for silver with nanoparticles as a separate fraction. Med Pr 2014;65(6:831–845

  20. Facilitating Effects of Emotion on the Perception of Biological Motion: Evidence for a Happiness Superiority Effect.

    Science.gov (United States)

    Lee, Hannah; Kim, Jejoong

    2017-06-01

    It has been reported that visual perception can be influenced not only by the physical features of a stimulus but also by the emotional valence of the stimulus, even without explicit emotion recognition. Some previous studies reported an anger superiority effect while others found a happiness superiority effect during visual perception. It thus remains unclear as to which emotion is more influential. In the present study, we conducted two experiments using biological motion (BM) stimuli to examine whether emotional valence of the stimuli would affect BM perception; and if so, whether a specific type of emotion is associated with a superiority effect. Point-light walkers with three emotion types (anger, happiness, and neutral) were used, and the threshold to detect BM within noise was measured in Experiment 1. Participants showed higher performance in detecting happy walkers compared with the angry and neutral walkers. Follow-up motion velocity analysis revealed that physical difference among the stimuli was not the main factor causing the effect. The results of the emotion recognition task in Experiment 2 also showed a happiness superiority effect, as in Experiment 1. These results show that emotional valence (happiness) of the stimuli can facilitate the processing of BM.

  1. Electromagnetic field induced biological effects in humans.

    Science.gov (United States)

    Kaszuba-Zwoińska, Jolanta; Gremba, Jerzy; Gałdzińska-Calik, Barbara; Wójcik-Piotrowicz, Karolina; Thor, Piotr J

    2015-01-01

    Exposure to artificial radio frequency electromagnetic fields (EMFs) has increased significantly in recent decades. Therefore, there is a growing scientific and social interest in its influence on health, even upon exposure significantly below the applicable standards. The intensity of electromagnetic radiation in human environment is increasing and currently reaches astronomical levels that had never before experienced on our planet. The most influential process of EMF impact on living organisms, is its direct tissue penetration. The current established standards of exposure to EMFs in Poland and in the rest of the world are based on the thermal effect. It is well known that weak EMF could cause all sorts of dramatic non-thermal effects in body cells, tissues and organs. The observed symptoms are hardly to assign to other environmental factors occurring simultaneously in the human environment. Although, there are still ongoing discussions on non-thermal effects of EMF influence, on May 31, 2011--International Agency for Research on Cancer (IARC)--Agenda of World Health Organization (WHO) has classified radio electromagnetic fields, to a category 2B as potentially carcinogenic. Electromagnetic fields can be dangerous not only because of the risk of cancer, but also other health problems, including electromagnetic hypersensitivity (EHS). Electromagnetic hypersensitivity (EHS) is a phenomenon characterized by the appearance of symptoms after exposure of people to electromagnetic fields, generated by EHS is characterized as a syndrome with a broad spectrum of non-specific multiple organ symptoms including both acute and chronic inflammatory processes located mainly in the skin and nervous systems, as well as in respiratory, cardiovascular systems, and musculoskeletal system. WHO does not consider the EHS as a disease-- defined on the basis of medical diagnosis and symptoms associated with any known syndrome. The symptoms may be associated with a single source of EMF

  2. Biological effect of radiation on human

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yun Sil; Cho, Chul Koo; Lee, Su Jae [and others

    2000-04-01

    1. Adaptive response when 0.01 Gy was preirradiated before high challenging dose is induced in normal cell types such normal lymphocytes, primary keratinocytes, and L929 fibroblast cells but not in neoplastic cells such as L5178Y lymphoma cells, EL-4 lymphoma cells and 308 papilloma cells. 2. Heat shock protein (HSP) 25 and inducible HSP70 is responsible for the induction of adaptive response and radioresistance - cell cycle regulation, antiapoptotic molecule and PKC activation were involved. 3. Apoptosis was induced at most 5. hrs after irradiation in primary keratinocytes, in v-rasHa transformed keratinocytes, the maximum interval was 16 hrs, and in 308 papilloma cells, the maximum was 48 hrs. 4. PKC response by radiation is correlated with induction of apoptosis. 5. Rapid induction PKCdelta in primary keratinocytes and no response of PKC epsilon may involved in radiation induced apoptosis. 6. The rate of resorption was increased when radiation was given at 2.5 days after gestation. Early death including foetal death were highly expressed when radiation was given at 7.5 days after gestation. There are no difference in incidence of late death including embryonic death. 7. 2 Gy is the most effective dose in radiation induced teratogenesis in mouse model. 8. Growth retardation and small head was present when radiation was given at 5.5, 7.5, 11.5 and 15.5 days after gestation and small head showed high incidence at 11.5 days after gestation. 9. External malformation, internal malformation and skeletal malformation was induced when radiation was given at 7.5 days after gestation. 10. OGG1-mutated cells induced radiosensitive by G2/M cell cycle arrest. 11. Radiation induced G2/M phase cell cycle and correlated with radiosensitivity. 12. PKCalpha induced differentiation. 13. Radiation exposed cells showed carcinogenic effect. 14. Organ specific radiosensitivity was shown and protein expression was involved.

  3. Biological effect of radiation on human

    International Nuclear Information System (INIS)

    Lee, Yun Sil; Cho, Chul Koo; Lee, Su Jae

    2000-04-01

    1. Adaptive response when 0.01 Gy was preirradiated before high challenging dose is induced in normal cell types such normal lymphocytes, primary keratinocytes, and L929 fibroblast cells but not in neoplastic cells such as L5178Y lymphoma cells, EL-4 lymphoma cells and 308 papilloma cells. 2. Heat shock protein (HSP) 25 and inducible HSP70 is responsible for the induction of adaptive response and radioresistance - cell cycle regulation, antiapoptotic molecule and PKC activation were involved. 3. Apoptosis was induced at most 5. hrs after irradiation in primary keratinocytes, in v-rasHa transformed keratinocytes, the maximum interval was 16 hrs, and in 308 papilloma cells, the maximum was 48 hrs. 4. PKC response by radiation is correlated with induction of apoptosis. 5. Rapid induction PKCdelta in primary keratinocytes and no response of PKC epsilon may involved in radiation induced apoptosis. 6. The rate of resorption was increased when radiation was given at 2.5 days after gestation. Early death including foetal death were highly expressed when radiation was given at 7.5 days after gestation. There are no difference in incidence of late death including embryonic death. 7. 2 Gy is the most effective dose in radiation induced teratogenesis in mouse model. 8. Growth retardation and small head was present when radiation was given at 5.5, 7.5, 11.5 and 15.5 days after gestation and small head showed high incidence at 11.5 days after gestation. 9. External malformation, internal malformation and skeletal malformation was induced when radiation was given at 7.5 days after gestation. 10. OGG1-mutated cells induced radiosensitive by G2/M cell cycle arrest. 11. Radiation induced G2/M phase cell cycle and correlated with radiosensitivity. 12. PKCalpha induced differentiation. 13. Radiation exposed cells showed carcinogenic effect. 14. Organ specific radiosensitivity was shown and protein expression was involved

  4. Engineering aspects of the experiment and results of animal tests. [Apollo 17 Biological Cosmic Ray Experiment

    Science.gov (United States)

    Look, B. C.; Tremor, J. W.; Barrows, W. F.; Zabower, H. R.; Suri, K.; Park, E. G., Jr.; Durso, J. A.; Leon, H. A.; Haymaker, W.; Lindberg, R. G.

    1975-01-01

    A closed passive system independent of support from the spacecraft or its crew was developed to house five pocket mice for their flight on Apollo XVII. The reaction of potassium superoxide with carbon dioxide and water vapor to produce oxygen provided a habitable atmosphere within the experiment package. The performance of the system and the ability of the mice to survive the key preflight tests gave reasonable assurance that the mice would also withstand the Apollo flight.-

  5. The Biological Effects of Weak Electromagnetic Fields

    International Nuclear Information System (INIS)

    Algattawi, A.; Elshyrih, H.

    2010-01-01

    Many studies investigated that weak electromagnetic fields remove calcium ions bound to the membranes of living cells, making them more likely to tear,. There is an enzyme that destroys DNA this enzyme leaking through the membranes of lysosomes explains the fragmentation of DNA. This case was seen in cells exposed to mobile phone signals. When this occurs in the germ line it reduces fertility and predicts genetic damage in future generations. Although leakage of calcium ions into the cytosol (the main part of the cell) accelerates the growth, but it also promotes the growth of tumors. Leakage of calcium ions into neurons (brain cells) makes nerve impulses accounting for pain and other neurological symptoms in electro sensitive. It also reduces the signal to noise ratio of the brain making it less likely to respond. This may be partially responsible for the increased accident rate of drivers using mobile phones. More details for the molecular mechanisms to explain characteristics of electromagnetic exposure are needed, e.g. I) why weak fields are more effective than strong ones, II) why some frequencies such as 16 Hz are especially potent and III) why pulsed fields do more damage

  6. Air pollution. [Japan; man; biological effects

    Energy Technology Data Exchange (ETDEWEB)

    1975-01-01

    Air pollution levels in Japan are reported along with some resultant health effects. Photochemical smog first occurred in Tokyo during 1967. On July 18, 1970, more than 40 students at the Rissei Girl's High School were treated for eye irritation and throat pain caused by photochemical smog; during July 18 to August 5 of the same year, more than 10,000 injuries were reported. The proportion of the population in Yokkaichi with chronic bronchitis was extraordinarily high among those residents 40 yr or older. The 1-hour sulfur dioxide concentration was as high as 2.5 ppM in the early 1960's in the city. The carbon monoxide concentrations at busy intersections in Tokyo were 10 to 15 ppM. The average CO concentration at the Tokyo Municipal Office in 1969 was 10.6 ppM, and more than 50% of the measurements were higher than the environmental standard (1-hour average) of 10 ppM for 24 consecutive hr. Lead poisoning occurred at the Ushigome ward in Tokyo during the late 1960's and promoted the issuing of new regulations for lead-containing gasoline. (auth)

  7. Enhancements in biologically effective ultraviolet radiation following volcanic eruptions

    Science.gov (United States)

    Vogelmann, A. M.; Ackerman, T. P.; Turco, R. P.

    1992-01-01

    A radiative transfer model is used to estimate the changes in biologically effective radiation (UV-BE) at the earth's surface produced by the El Chichon (1982) and Mount Pinatubo (1991) eruptions. It is found that in both cases surface intensity can increase because the effect of ozone depletion outweighs the increased scattering.

  8. Biological effectiveness of neutron irradiation on animals and man

    Energy Technology Data Exchange (ETDEWEB)

    Straume, T.

    1982-11-01

    Neutron experiments on a highly radiosensitive in vivo system - oocytes in mice - provide new insight into the nature of the radiosensitive targets of these important cells. With the radiobiological literature as background, neutron data from animals and humans are integrated, and the controversial question of radiation protection standards for neutrons is addressed. Oocyte killing in juvenile mice by 0.43-MeV, /sup 252/Cf-fission, and 15 MeV neutrons, compared with that by /sup 60/Co gamma rays, yields unusually low neutron RBEs (relative biological effectiveness). At 0.1 rad of 0.43-MeV neutrons the RBE is only 1.8, contrasting greatly with values of 100 or more reported at low-doses for other endpoints. In mice just prior to birth, however, when oocytes are less radiosensitive, the neutron RBE is much higher, similar to values for most other mammalian endpoints. This dramatic change in neutron RBE with mouse age (occurring within 2 to 3 days) can be explained as the result of a shift from a less radiosensitive target (presumably nuclear DNA) to a much more radiosensitive one (probably the oocyte plasma membrane). Using various approaches, a value for the neutron Quality Factor (Q, a radiation protection standard) is estimated as 17 (+-100%), much lower than 100 which has been suggested. With the large uncertainty, 17 is not markedly different from the value of 10 presently in general use.

  9. Biological effectiveness of neutron irradiation on animals and man

    International Nuclear Information System (INIS)

    Straume, T.

    1982-11-01

    Neutron experiments on a highly radiosensitive in vivo system - oocytes in mice - provide new insight into the nature of the radiosensitive targets of these important cells. With the radiobiological literature as background, neutron data from animals and humans are integrated, and the controversial question of radiation protection standards for neutrons is addressed. Oocyte killing in juvenile mice by 0.43-MeV, 252 Cf-fission, and 15 MeV neutrons, compared with that by 60 Co gamma rays, yields unusually low neutron RBEs (relative biological effectiveness). At 0.1 rad of 0.43-MeV neutrons the RBE is only 1.8, contrasting greatly with values of 100 or more reported at low-doses for other endpoints. In mice just prior to birth, however, when oocytes are less radiosensitive, the neutron RBE is much higher, similar to values for most other mammalian endpoints. This dramatic change in neutron RBE with mouse age (occurring within 2 to 3 days) can be explained as the result of a shift from a less radiosensitive target (presumably nuclear DNA) to a much more radiosensitive one (probably the oocyte plasma membrane). Using various approaches, a value for the neutron Quality Factor (Q, a radiation protection standard) is estimated as 17 (+-100%), much lower than 100 which has been suggested. With the large uncertainty, 17 is not markedly different from the value of 10 presently in general use

  10. Bone effects of biologic drugs in rheumatoid arthritis.

    Science.gov (United States)

    Corrado, Addolorata; Neve, Anna; Maruotti, Nicola; Cantatore, Francesco Paolo

    2013-01-01

    Biologic agents used in the treatment of rheumatoid arthritis (RA) are able to reduce both disease activity and radiographic progression of joint disease. These drugs are directed against several proinflammatory cytokines (TNF α , IL-6, and IL-1) which are involved both in the pathogenesis of chronic inflammation and progression of joint structural damage and in systemic and local bone loss typically observed in RA. However, the role of biologic drugs in preventing bone loss in clinical practice has not yet clearly assessed. Many clinical studies showed a trend to a positive effect of biologic agents in preventing systemic bone loss observed in RA. Although the suppression of inflammation is the main goal in the treatment of RA and the anti-inflammatory effects of biologic drugs exert a positive effect on bone metabolism, the exact relationship between the prevention of bone loss and control of inflammation has not been clearly established, and if the available biologic drugs against TNF α , IL-1, and IL-6 can exert their effect on systemic and local bone loss also through a direct mechanism on bone cell metabolism is still to be clearly defined.

  11. Gene-environment interaction in Major Depression: focus on experience-dependent biological systems

    Directory of Open Access Journals (Sweden)

    Nicola eLopizzo

    2015-05-01

    Full Text Available Major Depressive Disorder (MDD is a multifactorial and polygenic disorder, where multiple and partially overlapping sets of susceptibility genes interact each other and with the environment, predisposing individuals to the development of the illness. Thus, MDD results from a complex interplay of vulnerability genes and environmental factors that act cumulatively throughout individual's lifetime. Among these environmental factors, stressful life experiences, especially those occurring early in life, have been suggested to exert a crucial impact on brain development, leading to permanent functional changes that may contribute to life long risk for mental health outcomes. In this review we will discuss how genetic variants (polymorphisms, SNPs within genes operating in neurobiological systems that mediate stress response and synaptic plasticity, can impact, by themselves, the vulnerability risk for MDD; we will also consider how this MDD risk can be further modulated when gene X environment interaction is taken into account. Finally, we will discuss the role of epigenetic mechanisms, and in particular of DNA methylation and miRNAs expression changes, in mediating the effect of the stress on the vulnerability risk to develop MDD. Taken together, in this review we aim to underlie the role of genetic and epigenetic processes involved in stress and neuroplasticity related biological systems on development of MDD after exposure to early life stress, thereby building the basis for future research and clinical interventions.

  12. The biologic effects of cigarette smoke on cancer cells.

    Science.gov (United States)

    Sobus, Samantha L; Warren, Graham W

    2014-12-01

    Smoking is one of the largest preventable risk factors for developing cancer, and continued smoking by cancer patients is associated with increased toxicity, recurrence, risk of second primary cancer, and mortality. Cigarette smoke (CS) contains thousands of chemicals, including many known carcinogens. The carcinogenic effects of CS are well established, but relatively little work has been done to evaluate the effects of CS on cancer cells. In this review of the literature, the authors demonstrate that CS induces a more malignant tumor phenotype by increasing proliferation, migration, invasion, and angiogenesis and by activating prosurvival cellular pathways. Significant work is needed to understand the biologic effect of CS on cancer biology, including the development of model systems and the identification of critical biologic mediators of CS-induced changes in cancer cell physiology. © 2014 American Cancer Society.

  13. Treatment planning for heavy ion radiotherapy: calculation and optimization of biologically effective dose

    International Nuclear Information System (INIS)

    Kraemer, M.; Scholz, M.

    2000-09-01

    We describe a novel approach to treatment planning for heavy ion radiotherapy based on the local effect model (LEM) which allows to calculate the biologically effective dose not only for the target region but for the entire irradiation volume. LEM is ideally suited to be used as an integral part of treatment planning code systems for active dose shaping devices like the GSI raster scan system. Thus, it has been incorporated into our standard treatment planning system for ion therapy (TRiP). Single intensity modulated fields can be optimized with respect to homogeneous biologically effective dose. The relative biological effectiveness (RBE) is calculated separately for each voxel of the patient CT. Our radiobiologically oriented code system is in use since 1995 for the planning of irradiation experiments with cell cultures and animals such as rats and minipigs. Since 1997 it is in regular and successful use for patient treatment planning. (orig.)

  14. Simulator experiments: effects of NPP operator experience on performance

    International Nuclear Information System (INIS)

    Beare, A.N.; Gray, L.H.

    1984-01-01

    During the FY83 research, a simulator experiment was conducted at the control room simulator for a GE Boiling Water Reactor (BWR) NPP. The research subjects were licensed operators undergoing requalification training and shift technical advisors (STAs). This experiment was designed to investigate the effects of senior reactor operator (SRO) experience, operating crew augmentation with an STA and practice, as a crew, upon crew and individual operator performance, in response to anticipated plant transients. Sixteen two-man crews of licensed operators were employed in a 2 x 2 factorial design. The SROs leading the crews were split into high and low experience groups on the basis of their years of experience as an SRO. One half of the high- and low-SRO experience groups were assisted by an STA. The crews responded to four simulated plant casualties. A five-variable set of content-referenced performance measures was derived from task analyses of the procedurally correct responses to the four casualties. System parameters and control manipulations were recorded by the computer controlling the simulator. Data on communications and procedure use were obtained from analysis of videotapes of the exercises. Questionnaires were used to collect subject biographical information and data on subjective workload during each simulated casualty. For four of the five performance measures, no significant differences were found between groups led by high (25 to 114 months) and low (1 to 17 months as an SRO) experience SROs. However, crews led by low experience SROs tended to have significantly shorter task performance times than crews led by high experience SROs. The presence of the STA had no significant effect on overall team performance in responding to the four simulated casualties. The FY84 experiments are a partial replication and extension of the FY83 experiment, but with PWR operators and simulator

  15. EFFECTS OF 5E LEARNING CYCLE ON STUDENTS ACHIEVEMENT IN BIOLOGY AND CHEMISTRY

    Directory of Open Access Journals (Sweden)

    Patrick Osawaru Ajaja,

    2012-01-01

    Full Text Available The major purpose of this study was to determine the effects of learning cycle as an instructional strategy on biology andchemistry students achievement. To guide this study, six research hypotheses were stated and tested at 0.05 level ofsignificance. The design of this study was 2x2x3x6 Pre-test Post-test non-equivalent control group quasi experimental design.These included two instructional groups (experimental and control groups, sex (male and female, repeated testing (Pre,Post and follow-up tests, and six weeks of experience. The samples of the study included six senior secondary schools, 112science students, and 12 biology and chemistry teachers. The instruments used for this study were: teacher’s questionnaireon knowledge and use of learning cycle (KULC; and Biology and Chemistry Achievement Test (BCAT. The data collected wereanalyzed with simple percentage, Analysis of Covariance (ANCOVA and student t-test statistics. The major findings of thestudy included that only 30.43% and 26.31% of biology and chemistry teachers have the knowledge that learning cycle is aninstructional method; all the biology and chemistry teachers sampled have never used learning cycle as an instructionalmethod; learning cycle had a significant effect on students achievement in biology and chemistry; students taught withlearning cycle significantly achieved better in biology/chemistry Post-test than those taught with lecture method; the posttestscores of students in the learning cycle group increased over the period of experience; non-significant difference in Posttestscores between males and females taught with learning cycle; non-significant interaction effect between method andsex on achievement; and a significant higher retention of biology and chemistry knowledge by students taught with learningcycle than those taught with lecture method. It was concluded that the method seems an appropriate instructional modelthat could be used to solve the problems of

  16. Third eye, the biological effects; 3. oeil, les effets biologiques

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2004-02-01

    The discovery of a third kind of photo-receptor cell in the human eye has permitted to better understand the biological effects of lighting, not only on the vision, but also on some nervous processes, like emotion, mood, stress, biological clock, etc.. This additional dimension has led the engineers of Philips Lighting company to launch a new indoor lighting concept named 'Carpe Diem'. This concept adapts both the illuminance and the color of a lighting system according to the type of work and to the expected stimulating effect. (J.S.)

  17. Biological effect of penetration controlled irradiation with ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Atsushi; Shimizu, Takashi; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Watanabe, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Yamashita, Takao

    1997-03-01

    To investigate the effect of local irradiation with ion beams on biological systems, technique for penetration controlled irradiation has been established. The range in a target was controlled by changing the distance from beam window in the atmosphere, and could be controlled linearly up to about 31 {mu}m in biological material. In addition, the effects of the penetration controlled irradiations with 1.5 MeV/u C and He ions were examined using tobacco pollen. The increased frequency of leaky pollen produced by ion beams suggests that the efficient pollen envelope damages would be induced at the range-end of ion beams. (author)

  18. Design of a Comprehensive Biochemistry and Molecular Biology Experiment: Phase Variation Caused by Recombinational Regulation of Bacterial Gene Expression

    Science.gov (United States)

    Sheng, Xiumei; Xu, Shungao; Lu, Renyun; Isaac, Dadzie; Zhang, Xueyi; Zhang, Haifang; Wang, Huifang; Qiao, Zheng; Huang, Xinxiang

    2014-01-01

    Scientific experiments are indispensable parts of Biochemistry and Molecular Biology. In this study, a comprehensive Biochemistry and Molecular Biology experiment about "Salmonella enterica" serovar Typhi Flagellar phase variation has been designed. It consisted of three parts, namely, inducement of bacterial Flagellar phase variation,…

  19. Biological isotopy. Introduction to the isotopic effects and to their applications in biology

    International Nuclear Information System (INIS)

    Tcherkez, G.

    2010-01-01

    Since their discovery in the beginning of the 20. century, the study of stable isotopes has considerably developed. This domain, which remained limited in its applications until the 1990's, has become particularly important thereafter thanks to its practical applications and in particular to its economical impacts. Many techniques used in fraud control, in drugs use control, in selection of high-yield plants etc are based on isotopic abundance measurements. This reference book gives a synthesis of our actual knowledge on the use of stable isotopes and of isotope fractionation in biology. It presents the basic notions of isotopic biochemistry and explains the origin of the isotopic effects. The application principles of these effects to metabolism, to organisms physiology, to environmental biology etc are explained and detailed using examples and exercises. The first chapters present the basic knowledge which defines, from a mathematical point-of-view, the isotopic effects of chemical reactions or of physical processes taking place in biology. The measurements principle of natural isotopes abundance is then synthesised. Finally, all these notions are applied at different scales: enzymes, physiology, metabolism, environment, ecosystems and fraud crackdown. (J.S.)

  20. The relative biological effectiveness of out-of-field dose

    International Nuclear Information System (INIS)

    Balderson, Michael; Koger, Brandon; Kirkby, Charles

    2016-01-01

    Purpose: using simulations and models derived from existing literature, this work investigates relative biological effectiveness (RBE) for out-of-field radiation and attempts to quantify the relative magnitudes of different contributing phenomena (spectral, bystander, and low dose hypersensitivity effects). Specific attention is paid to external beam radiotherapy treatments for prostate cancer. Materials and methods: using different biological models that account for spectral, bystander, and low dose hypersensitivity effects, the RBE was calculated for different points moving radially out from isocentre for a typical single arc VMAT prostate case. The RBE was found by taking the ratio of the equivalent dose with the physical dose. Equivalent doses were calculated by determining what physical dose would be necessary to produce the same overall biological effect as that predicted using the different biological models. Results: spectral effects changed the RBE out-of-field less than 2%, whereas response models incorporating low dose hypersensitivity and bystander effects resulted in a much more profound change of the RBE for out-of-field doses. The bystander effect had the largest RBE for points located just outside the edge of the primary radiation beam in the cranial caudal (z-direction) compared to low dose hypersensitivity and spectral effects. In the coplanar direction, bystander effect played the largest role in enhancing the RBE for points up to 8.75 cm from isocentre. Conclusions: spectral, bystander, and low dose hypersensitivity effects can all increase the RBE for out-of-field radiation doses. In most cases, bystander effects seem to play the largest role followed by low dose hypersensitivity. Spectral effects were unlikely to be of any clinical significance. Bystander, low dose hypersensitivity, and spectral effect increased the RBE much more in the cranial caudal direction (z-direction) compared with the coplanar directions. (paper)

  1. Interpretation of biological-rate coefficients derived from radionuclide content, radionuclide concentration and specific activity experiments

    International Nuclear Information System (INIS)

    Vanderploeg, H.A.; Booth, R.S.

    1976-01-01

    Rigorous expressions are derived for the biological-rate coefficients (BRCs) determined from time-dependent measurements of three different dependent variables of radionuclide tracer experiments. These variables, which apply to a single organism, are radionuclide content, radionuclide concentration and specific activity. The BRCs derived from these variables have different mathematical expressions and, for high growth rates, their numerical values can be quite different. The precise mathematical expressions for the BRCs are presented here to aid modelers in selecting the correct parameters for their models and to aid experiments in interpreting their results. The usefulness of these three variables in quantifying elemental uptakes and losses by organisms is discussed. (U.K.)

  2. Numerical analysis of biological clogging in two-dimensional sand box experiments

    DEFF Research Database (Denmark)

    Kildsgaard, J.; Engesgaard, Peter Knudegaard

    2001-01-01

    Two-dimensional models for biological clogging and sorptive tracer transport were used to study the progress of clogging in a sand box experiment. The sand box had been inoculated with a strip of bacteria and exposed to a continuous injection of nitrate and acetate. Brilliant Blue was regularly...... injected during the clogging experiment and digital images of the tracer movement had been converted to concentration maps using an image analysis. The calibration of the models to the Brilliant Blue observations shows that Brilliant Blue has a solid biomass dependent sorption that is not compliant...... with the assumed linear constant Kd behaviour. It is demonstrated that the dimensionality of sand box experiments in comparison to column experiments results in a much lower reduction in hydraulic conductivity Žfactor of 100. and that the bulk hydraulic conductivity of the sand box decreased only slightly. However...

  3. The mechanism for the primary biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    Byakov, Vsevolod M; Stepanov, Sergei V

    2006-01-01

    The primary biological response of living organisms to the passage of fast charged particles is traditionally believed to be dominated by the chemical reactions of the radical products from the radiolysis of cellular water (OH, H, e aq - , O 2 - , H 2 O 2 ) and by the bioradicals that they produce (and which can also result from the direct electronic activation of biomolecules). This understanding has provided insight into how ionizing radiations affect biological systems and, most importantly, what radioprotection and radiosensibilizing effects are produced by chemical compounds introduced into an organism. However, a number of key radiobiological facts remain unexplained by the current theory, stimulating a search for other biologically active factors that may be triggered by radiation. This review examines a fact that is usually ignored in discussing the biological impact of ionizing radiation: the local increase in acidity in the water solution along the track of a charged particle. The acidity in the track is very different from its value for cellular water in a living organism. Biological processes are well-known to be highly sensitive to changes in the environmental acidity. It seems that the biological impact of ionizing radiations is dominated not by the water radiolysis products (mostly radicals) listed above but particles of a different nature, hydroxonium ions H 3 O + , where the term hydroxonium refer to protonated water molecules. This modification of the mechanism of primary radiobiological effects is in good agreement with experimental data. In particular, the extremal dependence of the relative biological efficiency (RBE) of radiations on their ionizing energy losses is accounted for in quantitative terms, as is the increase in the RBE in the relativistic energy range. (reviews of topical problems)

  4. Physical and biological factors determining the effective proton range

    International Nuclear Information System (INIS)

    Grün, Rebecca; Friedrich, Thomas; Krämer, Michael; Scholz, Michael; Zink, Klemens; Durante, Marco; Engenhart-Cabillic, Rita

    2013-01-01

    Purpose: Proton radiotherapy is rapidly becoming a standard treatment option for cancer. However, even though experimental data show an increase of the relative biological effectiveness (RBE) with depth, particularly at the distal end of the treatment field, a generic RBE of 1.1 is currently used in proton radiotherapy. This discrepancy might affect the effective penetration depth of the proton beam and thus the dose to the surrounding tissue and organs at risk. The purpose of this study was thus to analyze the impact of a tissue and dose dependent RBE of protons on the effective range of the proton beam in comparison to the range based on a generic RBE of 1.1.Methods: Factors influencing the biologically effective proton range were systematically analyzed by means of treatment planning studies using the Local Effect Model (LEM IV) and the treatment planning software TRiP98. Special emphasis was put on the comparison of passive and active range modulation techniques.Results: Beam energy, tissue type, and dose level significantly affected the biological extension of the treatment field at the distal edge. Up to 4 mm increased penetration depth as compared to the depth based on a constant RBE of 1.1. The extension of the biologically effective range strongly depends on the initial proton energy used for the most distal layer of the field and correlates with the width of the distal penumbra. Thus, the range extension, in general, was more pronounced for passive as compared to active range modulation systems, whereas the maximum RBE was higher for active systems.Conclusions: The analysis showed that the physical characteristics of the proton beam in terms of the width of the distal penumbra have a great impact on the RBE gradient and thus also the biologically effective penetration depth of the beam

  5. Effects of hypervitaminosis of vitamin B3 on silkworm biology

    Indian Academy of Sciences (India)

    Unknown

    [Etebari K and Matindoost L 2004 Effects of hypervitaminosis of vitamin B3 on silkworm biology; J. Biosci. 29 417–422]. 1. ... ate growth of larvae and the reproduction in many insects and also mites has been ... were dried in air for 10 min.

  6. Nutrigenetic Effect of Moringa oleifera Seed Meal on the Biological ...

    African Journals Online (AJOL)

    Nutrigenetic Effect of Moringa oleifera Seed Meal on the Biological Growth Programme of Young Broiler Chickens. ... Asked Questions about PDFs. Alternatively, you can download the PDF file directly to your computer, from where it can be opened using a PDF reader. To download the PDF, click the Download link above.

  7. High school and college biology: A multi-level model of the effects of high school biology courses on student academic performance in introductory college biology courses

    Science.gov (United States)

    Loehr, John Francis

    The issue of student preparation for college study in science has been an ongoing concern for both college-bound students and educators of various levels. This study uses a national sample of college students enrolled in introductory biology courses to address the relationship between high school biology preparation and subsequent introductory college biology performance. Multi-Level Modeling was used to investigate the relationship between students' high school science and mathematics experiences and college biology performance. This analysis controls for student demographic and educational background factors along with factors associated with the college or university attended. The results indicated that high school course-taking and science instructional experiences have the largest impact on student achievement in the first introductory college biology course. In particular, enrollment in courses, such as high school Calculus and Advanced Placement (AP) Biology, along with biology course content that focuses on developing a deep understanding of the topics is found to be positively associated with student achievement in introductory college biology. On the other hand, experiencing high numbers of laboratory activities, demonstrations, and independent projects along with higher levels of laboratory freedom are associated with negative achievement. These findings are relevant to high school biology teachers, college students, their parents, and educators looking beyond the goal of high school graduation.

  8. Multichannel microformulators for massively parallel machine learning and automated design of biological experiments

    Science.gov (United States)

    Wikswo, John; Kolli, Aditya; Shankaran, Harish; Wagoner, Matthew; Mettetal, Jerome; Reiserer, Ronald; Gerken, Gregory; Britt, Clayton; Schaffer, David

    Genetic, proteomic, and metabolic networks describing biological signaling can have 102 to 103 nodes. Transcriptomics and mass spectrometry can quantify 104 different dynamical experimental variables recorded from in vitro experiments with a time resolution approaching 1 s. It is difficult to infer metabolic and signaling models from such massive data sets, and it is unlikely that causality can be determined simply from observed temporal correlations. There is a need to design and apply specific system perturbations, which will be difficult to perform manually with 10 to 102 externally controlled variables. Machine learning and optimal experimental design can select an experiment that best discriminates between multiple conflicting models, but a remaining problem is to control in real time multiple variables in the form of concentrations of growth factors, toxins, nutrients and other signaling molecules. With time-division multiplexing, a microfluidic MicroFormulator (μF) can create in real time complex mixtures of reagents in volumes suitable for biological experiments. Initial 96-channel μF implementations control the exposure profile of cells in a 96-well plate to different temporal profiles of drugs; future experiments will include challenge compounds. Funded in part by AstraZeneca, NIH/NCATS HHSN271201600009C and UH3TR000491, and VIIBRE.

  9. Radiation research contracts: Biological effects of small radiation doses

    Energy Technology Data Exchange (ETDEWEB)

    Hug, O [International Atomic Energy Agency, Division of Health, Safety and Waste Disposal, Vienna (Austria)

    1959-04-15

    To establish the maximum permissible radiation doses for occupational and other kinds of radiation exposure, it is necessary to know those biological effects which can be produced by very small radiation doses. This particular field of radiation biology has not yet been sufficiently explored. This holds true for possible delayed damage after occupational radiation exposure over a period of many years as well as for acute reactions of the organism to single low level exposures. We know that irradiation of less than 25 Roentgen units (r) is unlikely to produce symptoms of radiation sickness. We have, however, found indications that even smaller doses may produce certain instantaneous reactions which must not be neglected

  10. Simulator experiments: effects of NPP operator experience on performance

    International Nuclear Information System (INIS)

    Beare, A.N.; Gray, L.H.

    1985-01-01

    Experiments are being conducted on nuclear power plant (NPP) control room training simulators by the Oak Ridge National Laboratory, its subcontractor, General Physics Corporation, and participating utilities. The experiments are sponsored by the Nuclear Regulatory Commission's (NRC) Human Factors and Safeguards Branch, Division of Risk Analysis and Operations, and are a continuation of prior research using simulators, supported by field data collection, to provide a technical basis for NRC human factors regulatory issues concerned with the operational safety of nuclear power plants. During the FY83 research, a simulator experiment was conducted at the control room simulator for a GE boiling water reactor (BWR) NPP. The research subjects were licensed operators undergoing requalification training and shift technical advisors (STAs). This experiment was designed to investigate the effects of (a) senior reactor operator (SRO) experience, (b) operating crew augmentation with an STA and (c) practice, as a crew, upon crew and individual operator performance, in response to anticipated plant transients. The FY84 experiments are a partial replication and extension of the FY83 experiment, but with PWR operators and simulator. Methodology and results to date are reported

  11. Distribution and Biological Effects of Nanoparticles in the Reproductive System.

    Science.gov (United States)

    Liu, Ying; Li, Hongxia; Xiao, Kai

    2016-01-01

    Nanoparticles have shown great potential in biomedical applications such as imaging probes and drug delivery. However, the increasing use of nanoparticles has raised concerns about their adverse effects on human health and environment. Reproductive tissues and gametes represent highly delicate biological systems with the essential function of transmitting genetic information to the offspring, which is highly sensitive to environmental toxicants. This review aims to summarzie the penetration of physiological barriers (blood-testis barrier and placental barrier), distribution and biological effects of nanoparticles in the reproductive system, which is essential to control the beneficial effects of nanoparticles applications and to avoid their adverse effects on the reproductive system. We referred to a large number of relevant peer-reviewed research articles about the reproductive toxicity of nanoparticles. The comprehensive information was summarized into two parts: physiological barrier penetration and biological effects of nanoparticles in male or female reproductive system; distribution and metabolism of nanoparticles in the reproductive system. The representative examples were also presented in four tables. The in vitro and in vivo studies imply that some nanoparticles are able to cross the blood-testis barrier or placental barrier, and their penetration depends on the physicochemical characteristics of nanoparticles (e.g., composition, shape, particle size and surface coating). The toxicity assays indicate that nanoparticles might induce adverse physiological effects and impede fertility or embryogenesis. The barrier penetration, adverse physiological effects, distribution and metabolism are closely related to physicochemical characteristics of nanoparticles. Further systematic and mechanistic studies using well-characterized nanoparticles, relevant administration routes, and doses relevant to the expected exposure level are required to improve our

  12. Study of the effects of radon in three biological systems

    International Nuclear Information System (INIS)

    Tavera, L.; Balcazar, M.; Lopez, A.; Brena, M.; Rosa, M.E. De la; Villalobos P, R.

    2002-01-01

    The radon and its decay products are responsible of the 3/4 parts of the exposure of the persons to the environmental radiation. The discovery at the end of XIX Century of the illnesses, mainly of cancer, which appeared in the presence of radon, lead to an accelerated growing of the radon studies: monitoring, dosimetry, effects on the persons, etc. Several epidemiological studies of radon in miners and population in general have been realized; advancing in the knowledge about the concentration-lung cancer risk relationship, but with discrepancies in the results depending on the concentration levels. Therefor, studies which consuming time, efforts and money go on doing. The research of the radon effects in biological systems different to human, allows to realize studies in less time, in controlled conditions and generally at lower cost, generating information about the alpha radiation effects in the cellular field. Therefor it was decided to study the response of three biological systems exposed to radon: an unicellular bacteria Escherichia Coli which was exposed directly to alpha particles from an electrodeposited source for determining the sensitivity limit of the chose technique. A plant, Tradescantia, for studying the cytogenetic effect of the system exposed to controlled concentrations of radon. An insect, Drosophila Melanogaster, for studying the genetic effects and the accumulated effects in several generations exposed to radon. In this work the experimental settlements are presented for the expositions of the systems and the biological results commenting the importance of these. (Author)

  13. Using Zebrafish to Implement a Course-Based Undergraduate Research Experience to Study Teratogenesis in Two Biology Laboratory Courses

    Science.gov (United States)

    Chism, Grady W.; Vaughan, Martin A.; Muralidharan, Pooja; Marrs, Jim A.

    2016-01-01

    Abstract A course-based undergraduate research experience (CURE) spanning three semesters was introduced into freshman and sophomore biology classes, with the hypothesis that participation in a CURE affects skills in research, communication, and collaboration, which may help students persist in science. Student research projects were centered on the hypothesis that nicotine and caffeine exposure during early development affects gastrulation and heart development in zebrafish. First, freshmen generated original data showing distinct effects of embryonic nicotine and caffeine exposure on zebrafish heart development and function. Next, Cell Biology laboratory students continued the CURE studies and identified novel teratogenic effects of nicotine and caffeine during gastrulation. Finally, new freshmen continued the CURE research, examining additional toxicant effects on development. Students designed new protocols, made measurements, presented results, and generated high-quality preliminary data that were studied in successive semesters. By implementing this project, the CURE extended faculty research and provided a scalable model to address national goals to involve more undergraduates in authentic scientific research. In addition, student survey results support the hypothesis that CUREs provide significant gains in student ability to (1) design experiments, (2) analyze data, and (3) make scientific presentations, translating into high student satisfaction and enhanced learning. PMID:26829498

  14. Berkeley Experiments on Superfluid Macroscopic Quantum Effects

    International Nuclear Information System (INIS)

    Packard, Richard

    2006-01-01

    This paper provides a brief history of the evolution of the Berkeley experiments on macroscopic quantum effects in superfluid helium. The narrative follows the evolution of the experiments proceeding from the detection of single vortex lines to vortex photography to quantized circulation in 3He to Josephson effects and superfluid gyroscopes in both 4He and 3He

  15. Evaluation of radiobiological effects in 3 distinct biological models

    International Nuclear Information System (INIS)

    Lemos, J.; Costa, P.; Cunha, L.; Metello, L.F.; Carvalho, A.P.; Vasconcelos, V.; Genesio, P.; Ponte, F.; Costa, P.S.; Crespo, P.

    2015-01-01

    Full text of publication follows. The present work aims at sharing the process of development of advanced biological models to study radiobiological effects. Recognizing several known limitations and difficulties of the current monolayer cellular models, as well as the increasing difficulties to use advanced biological models, our group has been developing advanced biological alternative models, namely three-dimensional cell cultures and a less explored animal model (the Zebra fish - Danio rerio - which allows the access to inter-generational data, while characterized by a great genetic homology towards the humans). These 3 models (monolayer cellular model, three-dimensional cell cultures and zebra fish) were externally irradiated with 100 mGy, 500 mGy or 1 Gy. The consequences of that irradiation were studied using cellular and molecular tests. Our previous experimental studies with 100 mGy external gamma irradiation of HepG2 monolayer cells showed a slight increase in the proliferation rate 24 h, 48 h and 72 h post irradiation. These results also pointed into the presence of certain bystander effects 72 h post irradiation, constituting the starting point for the need of a more accurate analysis realized with this work. At this stage, we continue focused on the acute biological effects. Obtained results, namely MTT and clonogenic assays for evaluating cellular metabolic activity and proliferation in the in vitro models, as well as proteomics for the evaluation of in vivo effects will be presented, discussed and explained. Several hypotheses will be presented and defended based on the facts previously demonstrated. This work aims at sharing the actual state and the results already available from this medium-term project, building the proof of the added value on applying these advanced models, while demonstrating the strongest and weakest points from all of them (so allowing the comparison between them and to base the subsequent choice for research groups starting

  16. Healthy Foundations Study: a randomised controlled trial to evaluate biological embedding of early-life experiences.

    Science.gov (United States)

    Gonzalez, Andrea; Catherine, Nicole; Boyle, Michael; Jack, Susan M; Atkinson, Leslie; Kobor, Michael; Sheehan, Debbie; Tonmyr, Lil; Waddell, Charlotte; MacMillan, Harriet L

    2018-01-26

    Adverse early experiences are associated with long-lasting disruptions in physiology, development and health. These experiences may be 'biologically embedded' into molecular and genomic systems that determine later expressions of vulnerability. Most studies to date have not examined whether preventive interventions can potentially reverse biological embedding. The Nurse-Family Partnership (NFP) is an evidence-based intervention with demonstrated efficacy in improving prenatal health, parenting and child functioning. The Healthy Foundations Study is an innovative birth cohort which will evaluate the impact of the NFP on biological outcomes of mothers and their infants. Starting in 2013, up to 400 pregnant mothers and their newborns were recruited from the British Columbia Healthy Connections Project-a randomised controlled trial of the NFP, and will be followed to child aged 2 years. Women were recruited prior to 28 weeks' gestation and then individually randomised to receive existing services (comparison group) or NFP plus existing services (intervention group). Hair samples are collected from mothers at baseline and 2 months post partum to measure physiological stress. Saliva samples are collected from infants during all visits for analyses of stress and immune function. Buccal swabs are collected from infants at 2 and 24 months to assess DNA methylation. Biological samples will be related to child outcome measures at age 2 years. The study received ethical approval from seven research ethics boards. Findings from this study will be shared broadly with the research community through peer-reviewed publications, and conference presentations, as well as seminars with our policy partners and relevant healthcare providers. The outcomes of this study will provide all stakeholders with important information regarding how early adversity may lead to health and behavioural disparities and how these may be altered through early interventions. NCT01672060; Pre-results.

  17. Radiolabelled substrates for studying biological effects of trace contaminants

    International Nuclear Information System (INIS)

    1975-01-01

    A programme of coordinated isotopic tracer-aided investigations of the biological side-effects of foreign chemical residues in food and agriculture, initiated in 1973, was reviewed. The current status of representative investigations from the point of view of techniques and priorities was assessed. Such investigations involved radioactive substrates for studying DNA injury and its repair; 14 C-labelled acetylcholine as substrate for measuring enzyme inhibition due to the presence of, or exposure to, anticholinesteratic contaminants; radioactive substrates as indication of side-effects in non-target organisms and of their comparative susceptibilities; radioactive substrates as indicators of persistence or biodegradability of trace contaminants of soil or water; and labelled pools for studying the biological side-effects of trace contaminants. Priorities were identified

  18. Biological effects of single HZE-particles of the cosmic radiation: Free Flyer Biostack

    International Nuclear Information System (INIS)

    1989-01-01

    The Free Flyer Biostack is designed as a passive, longer term experiment for investigations into the dosimetry of cosmic HZE particles (high-charge energetic particles), the effects of single HZE particles on isolated biological samples, and the synergistic effects of conditions in space, as e.g. zero gravity and presence of a permanent, weakly ionizing component of the cosmic radiation. For the experiments summarized in this project report, the AgCl detector type developed in Frankfurt has been used, consisting of monocrystalline AgCl films, about 130-150 μm thick, and doped with 5000 ppm of Cd. (DG) With 9 figs [de

  19. Quantifying pCO2 in biological ocean acidification experiments: A comparison of four methods.

    Science.gov (United States)

    Watson, Sue-Ann; Fabricius, Katharina E; Munday, Philip L

    2017-01-01

    Quantifying the amount of carbon dioxide (CO2) in seawater is an essential component of ocean acidification research; however, equipment for measuring CO2 directly can be costly and involve complex, bulky apparatus. Consequently, other parameters of the carbonate system, such as pH and total alkalinity (AT), are often measured and used to calculate the partial pressure of CO2 (pCO2) in seawater, especially in biological CO2-manipulation studies, including large ecological experiments and those conducted at field sites. Here we compare four methods of pCO2 determination that have been used in biological ocean acidification experiments: 1) Versatile INstrument for the Determination of Total inorganic carbon and titration Alkalinity (VINDTA) measurement of dissolved inorganic carbon (CT) and AT, 2) spectrophotometric measurement of pHT and AT, 3) electrode measurement of pHNBS and AT, and 4) the direct measurement of CO2 using a portable CO2 equilibrator with a non-dispersive infrared (NDIR) gas analyser. In this study, we found these four methods can produce very similar pCO2 estimates, and the three methods often suited to field-based application (spectrophotometric pHT, electrode pHNBS and CO2 equilibrator) produced estimated measurement uncertainties of 3.5-4.6% for pCO2. Importantly, we are not advocating the replacement of established methods to measure seawater carbonate chemistry, particularly for high-accuracy quantification of carbonate parameters in seawater such as open ocean chemistry, for real-time measures of ocean change, nor for the measurement of small changes in seawater pCO2. However, for biological CO2-manipulation experiments measuring differences of over 100 μatm pCO2 among treatments, we find the four methods described here can produce similar results with careful use.

  20. [Biological effects of non-ionizing electromagnetic radiation].

    Science.gov (United States)

    Fedorowski, A; Steciwko, A

    1998-01-01

    Since the mid 1970's, when Adey discovered that extremely-low-frequency electromagnetic field (ELF EMF) may affect the calcium ions efflux from various cells, bioeffects of non-ionizing radiation (NIR) have become the subject of growing interest and numerous research projects. At present, the fact that NIR exerts both stimulatory and inhibitory effects on different physiological cellular parameters is rather unquestionable. At the same time, some epidemiological studies suggest that exposure to EMF is potentially harmful even if its intensity is very low. It has been proved that thermal factors are not responsible for these effects, therefore nowadays, they are called 'non-thermal effects'. Our paper deals with three different aspects of biological effects of non-ionizing radiation, bioelectromagnetism, electromagnetobiology and electromagnetic bioinformation. Firstly, we describe how EMF and photons can be produced within a living cell, how biological cycles are controlled, and what are the features of endogenous electromagnetic radiation. Secondly, we discuss various facets of external EMF interactions with living matter, focusing on extremely-low-frequencies, radio- and microwaves. Possible mechanisms of these interactions are also mentioned. Finally, we present a short overview of current theories which explain how electromagnetic couplings may control an open and dissipative structure, namely the living organism. The theory of electromagnetic bioinformation seems to explain how different physiological processes are triggered and controlled, as well as how long-range interactions may possibly occur within the complex biological system. The review points out that the presented research data must be assessed very carefully since its evaluation is crucial to set the proper limits of EMF exposure, both occupational and environmental. The study of biological effects of non-ioinizing radiation may also contribute to the development of new diagnostic and therapeutic

  1. Oxygen effect in radiation biology: caffeine and serendipity

    International Nuclear Information System (INIS)

    Kesavan, P.C.

    2005-01-01

    The 'hit theory' developed in 1920s to explain the actions of ionizing radiation on cells and organisms was purely physical, and its limitation was its inadequacy to address the contemporary findings such as the oxygen enhancement of radiobiological damage, and the increased radio- sensitivity of dividing compared to non-dividing cells. The textbooks written prior to 1970s did not either refer at all to oxygen as a radiosensitizer, or had mentioned it only in a passing manner; yet 'oxygen effect' was emerging as the central dogma in radiation biology. The oxygen effect in radiation biology is highly interdisciplinary encompassing atomic physics (i.e. interaction of photon with matter), radiation chemistry (formation of reactive oxygen species), molecular signalling, gene expression and genetic alterations in cells (mutation, cancer) or the cell death (apoptosis, necrosis, mitotic catastrophe, etc.). Cell death in higher organisms is now recognized as the precursor of possible error-free cell replacement repair. (author)

  2. Biological effect of nitrogen ion implantation on stevia

    International Nuclear Information System (INIS)

    Wang Cailian; Shen Mei; Chen Qiufang; Shu Shizhen

    1997-10-01

    Dry seed of stevia were implanted by 35∼150 keV nitrogen ions with various doses. The biological effect in M 1 was studied. The results showed that nitrogen ion beam was able to induce variation on chromosome structure in root tip cells. The rate of cells with chromosome aberration was increased with ion beam energy and dose added, but there was on significant linear regression relationship between ion dose and aberration rate. The results indicated the seedling height reduced with the increasing of dose for ion beam. The biological effect of nitrogen ion beam on M 1 stevia was lower than that of γ-rays. (6 refs., 1 fig., 4 tabs.)

  3. Advances in the biological effects of terahertz wave radiation.

    Science.gov (United States)

    Zhao, Li; Hao, Yan-Hui; Peng, Rui-Yun

    2014-01-01

    The terahertz (THz) band lies between microwave and infrared rays in wavelength and consists of non-ionizing radiation. Both domestic and foreign research institutions, including the army, have attached considerable importance to the research and development of THz technology because this radiation exhibits both photon-like and electron-like properties, which grant it considerable application value and potential. With the rapid development of THz technology and related applications, studies of the biological effects of THz radiation have become a major focus in the field of life sciences. Research in this field has only just begun, both at home and abroad. In this paper, research progress with respect to THz radiation, including its biological effects, mechanisms and methods of protection, will be reviewed.

  4. Determination of the Fatty Acid Content of Biological Membranes: A Highly Versatile GC-MS Experiment

    Science.gov (United States)

    Schultz, Emeric; Pugh, Michael Eugene

    2001-07-01

    The experiment involves the GC-MS of fatty acid methyl esters (FAMEs) obtained from bacterial membranes. It takes about 2 h, from cell harvest to injection. This experiment is done in a lab course for non-science majors and in biochemistry. For non-science majors the focus is on GC-MS as a technique for fingerprinting and on the underlying basis of that fingerprinting. In biochemistry the focus is on the composition of membranes and how this changes with temperature--specifically how the ratio of saturated to unsaturated fatty acids changes to maintain constant cell fluidity. Combined with a parallel DNA experiment, the two major types of intermolecular forces important for the structure and function of biomolecules are compared. How this versatile experiment could be adapted in other chemistry courses is presented. The experiment has obvious appeal to biology majors, can be used to develop several important chemistry concepts, involves teamwork, and employs an important instrument. It could be used in the laboratory portion of a course other than biochemistry to fulfill the new ACS biochemistry requirement.

  5. Biological effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    Gonzalez, A.J.

    1994-01-01

    Few weeks ago, when the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) submitted to the U.N. General Assembly the UNSCEAR 1994 report, the international community had at its disposal a broad view of the biological effects of low doses of ionizing radiation. The 1994 report (272 pages) specifically addressed the epidemiological studies of radiation carcinogenesis and the adaptive responses to radiation in cells and organisms. The report was aimed to supplement the UNSCEAR 1993 report to the U.N. General Assembly- an extensive document of 928 pages-which addressed the global levels of radiation exposing the world population, as well as some issues on the effects of ionizing radiation, including: mechanisms of radiation oncogenesis due to radiation exposure, influence of the level of dose and dose rate on stochastic effects of radiation, hereditary effects of radiation effects on the developing human brain, and the late deterministic effects in children. Those two UNSCEAR reports taken together provide an impressive overview of current knowledge on the biological effects of ionizing radiation. This article summarizes the essential issues of both reports, although it cannot cover all available information. (Author)

  6. Small-scale laser based electron accelerators for biology and medicine: a comparative study of the biological effectiveness

    Science.gov (United States)

    Labate, Luca; Andreassi, Maria Grazia; Baffigi, Federica; Basta, Giuseppina; Bizzarri, Ranieri; Borghini, Andrea; Candiano, Giuliana C.; Casarino, Carlo; Cresci, Monica; Di Martino, Fabio; Fulgentini, Lorenzo; Ghetti, Francesco; Gilardi, Maria Carla; Giulietti, Antonio; Köster, Petra; Lenci, Francesco; Levato, Tadzio; Oishi, Yuji; Russo, Giorgio; Sgarbossa, Antonella; Traino, Claudio; Gizzi, Leonida A.

    2013-05-01

    Laser-driven electron accelerators based on the Laser Wakefield Acceleration process has entered a mature phase to be considered as alternative devices to conventional radiofrequency linear accelerators used in medical applications. Before entering the medical practice, however, deep studies of the radiobiological effects of such short bunches as the ones produced by laser-driven accelerators have to be performed. Here we report on the setup, characterization and first test of a small-scale laser accelerator for radiobiology experiments. A brief description of the experimental setup will be given at first, followed by an overview of the electron bunch characterization, in particular in terms of dose delivered to the samples. Finally, the first results from the irradiation of biological samples will be briefly discussed.

  7. Effect of Ceramic Scaffold Architectural Parameters on Biological Response

    Directory of Open Access Journals (Sweden)

    Maria Isabella eGariboldi

    2015-10-01

    Full Text Available Numerous studies have focused on the optimization of ceramic architectures to fulfill a variety of scaffold functional requirements and improve biological response. Conventional fabrication techniques, however, do not allow for the production of geometrically controlled, reproducible structures and often fail to allow the independent variation of individual geometric parameters. Current developments in additive manufacturing technologies suggest that 3D printing will allow a more controlled and systematic exploration of scaffold architectures. This more direct translation of design into structure requires a pipeline for design-driven optimization. A theoretical framework for systematic design and evaluation of architectural parameters on biological response is presented. Four levels of architecture are considered, namely (1 surface topography, (2 pore size and geometry, (3 porous networks and (4 macroscopic pore arrangement, including the potential for spatially varied architectures. Studies exploring the effect of various parameters within these levels are reviewed. This framework will hopefully allow uncovering of new relationships between architecture and biological response in a more systematic way, as well as inform future refinement of fabrication techniques to fulfill architectural necessities with a consideration of biological implications.

  8. Dosimetric characteristics of biological effect of sulfur-35

    International Nuclear Information System (INIS)

    Borisova, V.V.

    1990-01-01

    Experimental materials related to evaluation of dosimetric characteristics of sulfur-35 are presented. Hemogenic organs are subjected to greatest influence especially in the first hours after radionuclide entry into the organism. Comparison is made of absorbed doses in blood with observed blastomogen effect of hemogenic organs. It is noted, that quantitative evaluation of relative biological efficiency of low energy beta-emitters should be performed with account of dosimetric peculiarities of the nuclides mentioned above. 10 refs.; 3 tabs

  9. Biological effects of the ionizing radiation. Press breakfast

    International Nuclear Information System (INIS)

    Flury-Herard, A.; Boiteux, S.; Dutrillaux, B.; Toledano, M.

    2000-06-01

    This document brings together the subjects discussed during the Press breakfast of 29 june 2000 on the biological effects of the ionizing radiations, with scientists of the CEA and the CNRS. It presents the research programs and provides inquiries on the NDA operating to introduce the NDA damages by ionizing radiations, the possible repairs and the repair efficiency facing the carcinogenesis. Those researches allow the scientists to define laws on radiation protection. (A.L.B.)

  10. Metabolism and biological effects of alpha-emitting radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Bair, W. J.

    1979-05-01

    The emphasis of much of the current and planned research on the toxicity of alpha-emitting radionuclides is directed toward the complexities of actual and potential conditions of occupational environmental exposures of human beings. These, as well as the more limited studies on mechanisms of biological transport and effects, should increase our ability to predict health risks more accurately and to deal more confidently with human exposures, if and when they occur.

  11. Behavioral and Biological Effects of Resonant Electromagnetic Absorption in Rats.

    Science.gov (United States)

    1976-11-01

    for 23-550 MHz, biological phantom materials to simulate tissue properties, monopole -above-ground radiation chamber, design of a waveguide slot array...Resonant Electromagnetic Power Absorption in Rats" L T OF FTCTIF S A,’L i .LIS SFigure Pa 1 A photograiph of the monopole -above-gruund radiation...and mice without ground effects (L/2b = 3.25 where 21Tb is the "average" circumference of the animals) ........ .................... ... 20 8

  12. Biological activity of selected plants with adaptogenic effect

    OpenAIRE

    Eva Ivanišová; Miroslava Kačániová; Jana Petrová; Radka Staňková; Lucia Godočíková; Tomáš Krajčovič; Štefan Dráb

    2016-01-01

    The aim of this study was to determine biological activity of plants with adaptogenic effect: Panax ginseng Mayer., Withania somnifera L., Eleuterococcus senticosus Rupr. et Maxim., Astragallus membranaceus Fisch. and Codonopsis pilosulae Franch. The antioxidant activity was detected by DPPH and phosphomolybdenum method, total polyphenol content with Folin – Ciocalteu reagent, flavonoids content by aluminium chloride method. The detection of antimicrobial activity was carried out by disc diff...

  13. SED-ED, a workflow editor for computational biology experiments written in SED-ML.

    Science.gov (United States)

    Adams, Richard R

    2012-04-15

    The simulation experiment description markup language (SED-ML) is a new community data standard to encode computational biology experiments in a computer-readable XML format. Its widespread adoption will require the development of software support to work with SED-ML files. Here, we describe a software tool, SED-ED, to view, edit, validate and annotate SED-ML documents while shielding end-users from the underlying XML representation. SED-ED supports modellers who wish to create, understand and further develop a simulation description provided in SED-ML format. SED-ED is available as a standalone Java application, as an Eclipse plug-in and as an SBSI (www.sbsi.ed.ac.uk) plug-in, all under an MIT open-source license. Source code is at https://sed-ed-sedmleditor.googlecode.com/svn. The application itself is available from https://sourceforge.net/projects/jlibsedml/files/SED-ED/.

  14. Comparison of ballistic impact effects between biological tissue and gelatin.

    Science.gov (United States)

    Jin, Yongxi; Mai, Ruimin; Wu, Cheng; Han, Ruiguo; Li, Bingcang

    2018-02-01

    Gelatin is commonly used in ballistic testing as substitute for biological tissue. Comparison of ballistic impact effects produced in the gelatin and living tissue is lacking. The work in this paper was aimed to compare the typical ballistic impact effects (penetration trajectory, energy transfer, temporary cavity) caused by 4.8mm steel ball penetrating the 60kg porcine hind limbs and 10wt% gelatin. The impact event in the biological tissue was recorded by high speed flash X-ray machine at different delay time, while the event in the gelatin continuously recorded by high speed video was compared to that in the biological tissue. The collected results clearly displayed that the ballistic impact effects in the muscle and gelatin were similar for the steel ball test; as for instance, the projectile trajectory in the two targets was basically similar, the process of energy transfer was highly coincident, and the expansion of temporary cavity followed the same pattern. This study fully demonstrated that choosing gelatin as muscle simulant was reasonable. However, the maximum temporary cavity diameter in the gelatin was a little larger than that in the muscle, and the expansion period of temporary cavity was longer in the gelatin. Additionally, the temporary cavity collapse process in the two targets followed different patterns, and the collapse period in the gelatin was two times as long as that in the muscle. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Biological effective dose studies in carcinoma of uterine cervix

    International Nuclear Information System (INIS)

    Yadav, Poonam; Ramasubramanian, V.

    2008-01-01

    Cancer of cervix is the second most common cancer worldwide among women. Several treatments related protocols of radiotherapy have been followed over few decades in its treatment for evaluating the response. These physical doses varying on the basics of fractionation size, dose rate and total dose needed to be indicated as biological effective dose (BED) to rationalize these treatments. The curative potential of radiation therapy in the management of carcinoma of the cervix is greatly enhanced by the use of intracavitary brachytherapy. Successful brachytherapy requires the high radiation dose to be delivered to the tumor where as minimum radiation dose reach to surrounding normal tissue. Present study is aimed to evaluate biologically effective dose in patients receiving high dose-rate brachytherapy plus external beam radiotherapy based on tumor cell proliferation values in cancer of the cervix patients. The study includes 30 patients' data as a retrospective analysis. In addition determine extent of a dose-response relationship existing between the biological effective dose at Point A and the bladder and rectum and the clinical outcomes

  16. The biological effectiveness of heavy ion radiations in the environment

    International Nuclear Information System (INIS)

    Craven, P.A.

    1996-03-01

    Although heavy ions are rarely encountered in the majority of terrestrial environments, the exposure of humans to this fascinating class of ionizing radiation is becoming more frequent. Long-duration spaceflight, new radiotherapeutic procedures and enhanced levels of radon, and other naturally-occurring alpha particle emitters, have all increased concern and stimulated interest recently within the radiological protection and radiobiological communities. Significant data concerning the long-term effects of low levels of heavy ions on mammalian systems are correspondingly scarce, leading to increased emphasis on modelling all aspects of the radiation-organism interaction. Contemporary radiation protection procedures reflect the need for a more fundamental understanding of the mechanisms responsible for the biological actions of such radiations. Major deficiencies exist in the current recommendations for assessment of relative effectiveness, the enhanced severity of the biological consequences instigated by heavy ions, over conventional sparsely ionizing radiations. In an attempt to remedy some of the inadequate concepts and assumptions presently employed and, simultaneously, to gain insight into the fundamental mechanisms behind the notion of radiation quality, a series of algorithms have been developed and executed as computer code, to evaluate the biological effectiveness of heavy ion radiation ''tracks'' according to a number of criteria. These include consideration of the spatial characteristics of physical energy deposition in idealised cellular structures (finite particle range, radial extension of tracks via δ-ray emission) and the likelihood of induction and mis-repair of severe molecular lesions (double-strand breaks, multiply-damaged sites). (author)

  17. The effect of cosmic rays on biological systems - an investigation during GLE events

    Science.gov (United States)

    Belisheva, N. K.; Lammer, H.; Biernat, H. K.; Vashenuyk, E. V.

    2012-01-01

    In this study, first direct and circumstantial evidences of the effects of cosmic rays (CR) on biological systems are presented. A direct evidence of biological effects of CR is demonstrated in experiments with three cellular lines growing in culture during three events of Ground Level Enhancement (GLEs) in the neutron count rate detected by ground-based neutron monitor in October 1989. Various phenomena associated with DNA lesion on the cellular level demonstrate coherent dynamics of radiation effects in all cellular lines coincident with the time of arrival of high-energy solar particles to the near-Earth space and with the main peak in GLE. These results were obtained in the course of six separate experiments, with partial overlapping of the time of previous and subsequent experiments, which started and finished in the quiet period of solar activity (SA). A significant difference between the values of multinuclear cells in all cellular lines in the quiet period and during GLE events indicates that the cause of radiation effects in the cell cultures is an exposure of cells to the secondary solar CR near the Earth's surface. The circumstantial evidence was obtained by statistical analysis of cases of congenital malformations (CM) at two sites in the Murmansk region. The number of cases of all classes of CM reveals a significant correlation with the number of GLE events. The number of cases of CM with pronounced chromosomal abnormalities clearly correlates with the GLE events that occurred a year before the birth of a child. We have found a significant correlation between modulations of the water properties and daily background variations of CR intensity. We believe that the effects of CR on biological systems can be also mediated by fluctuations in water properties, considered as one of possible mechanisms controlling the effects of CRs on biological systems.

  18. S.E.A. Lab. Science Experiments and Activities. Marine Science for High School Students in Chemistry, Biology and Physics.

    Science.gov (United States)

    Hart, Kathy, Ed.

    A series of science experiments and activities designed for secondary school students taking biology, chemistry, physics, physical science or marine science courses are outlined. Each of the three major sections--chemistry, biology, and physics--addresses concepts that are generally covered in those courses but incorporates aspects of marine…

  19. Effects of Emotional Experience in Lexical Decision

    Directory of Open Access Journals (Sweden)

    Paul D Siakaluk

    2016-08-01

    Full Text Available Previous research has examined the effects of emotional experience (i.e., the ease with which words evoke emotion information in semantic categorization, word naming, and Stroop tasks (Moffat, Siakaluk, Sidhu, & Pexman, 2015; Newcombe, Campbell, Siakaluk, & Pexman, 2012; Siakaluk, Knol, & Pexman, 2014. However, to date there are no published reports on whether emotional experience influences performance in the lexical decision task (LDT. In the present study, we examined the influence of emotional experience in LDT using three different stimulus sets. In Experiment 1 we used a stimulus set used by both Kousta, Vinson, and Vigliocco (2009; Experiment 1 and Yap and Seow (2014 that is comprised of 40 negative, 40 positive, and 40 neutral words; in Experiment 2 we used a stimulus set comprised of 150 abstract nouns; and in Experiment 3 we used a stimulus set comprised of 373 verbs. We observed facilitatory effects of emotional experience in each of the three experiments, such that words with higher emotional experience ratings were associated with faster response latencies. These results are important because the influence of emotional experience: (a is observed in stimulus sets comprised of different types of words, demonstrating the generalizability of the effect in LDT; (b accounts for LDT response latency variability above and beyond the influences of valence and arousal, and is thus a robust dimension of conceptual knowledge; (c suggests that a richer representation of emotional experience provides more reliable evidence that a stimulus is a word, which facilitates responding in LDT; and (d is consistent with grounded cognition frameworks that propose that emotion information may be grounded in bodily experience with the world (Barsalou, 2003, 2009; Vigliocco, Meteyard, Andrews, & Kousta, 2009.

  20. Benveniste’s Experiments Explained by a Non-Conventional Experimenter Effect

    Directory of Open Access Journals (Sweden)

    Francis Beauvais

    2018-03-01

    Full Text Available Background: Benveniste’s biology experiments suggested the existence of molecular-like effects without molecules (“memory of water”. In this article, it is proposed that these disputed experiments could have been the consequence of a previously unnoticed and non-conventional experimenter effect. Methods: A probabilistic modelling is built in order to describe an elementary laboratory experiment. A biological system is modelled with two possible states (“resting” and “activated” and exposed to two experimental conditions labelled “control” and “test”, but both are biologically inactive. The modelling takes into account not only the biological system, but also the experimenters. In addition, an outsider standpoint is adopted to describe the experimental situation. Results: A classical approach suggests that, after experiment completion, the “control” and “test” labels of biologically-inactive conditions should both be associated with the “resting” state (i.e., no significant relationship between labels and system states. However, if the fluctuations of the biological system are also considered, a quantum-like relationship emerges and connects labels and system states (analogous to a biological “effect” without molecules. Conclusions: No hypotheses about water properties or other exotic explanations are needed to describe Benveniste’s experiments, including their unusual features. This modelling could be extended to other experimental situations in biology, medicine, and psychology.

  1. Increasing sponsorship effectiveness through brand experience.

    NARCIS (Netherlands)

    Fransen, M.L.; van Rompay, T.J.L.; Muntinga, D.G.

    2013-01-01

    This quasi-experimental field study examines whether companies can improve the effectiveness of their sponsorship investments by creating a brand experience. Data were collected among participants of a sponsored marathon. During this event participants had the opportunity to engage in an experience

  2. A synchrotron-based X-ray exposure station for radiation biology experiments

    International Nuclear Information System (INIS)

    Thompson, A.C.; Blakely, E.A.; Bjornstad, K.A.; Chang, P.Y.; Rosen, C.J.; Schwarz, R.I.

    2007-01-01

    Synchrotron X-ray sources enable radiation biology experiments that are difficult with conventional sources. A synchrotron source can easily deliver a monochromatic, tunable energy, highly collimated X-ray beam of well-calibrated intensity. An exposure station at beamline 10.3.1 of the Advanced Light Source (ALS) has been developed which delivers a variable energy (5-20 keV) X-ray fan beam with very sharp edges (10-90% in less than 3 μm). A series of experiments have been done with a four-well slide where a stripe (100 μm widex18 mm long) of cells in each well has been irradiated and the dose varied from well to well. With this facility we have begun a series of experiments to study cells adjacent to irradiated cells and how they respond to the damage of their neighbors. Initial results have demonstrated the advantages of using synchrotron radiation for these experiments

  3. A synchrotron-based X-ray exposure station for radiation biology experiments

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, A.C. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States)], E-mail: acthompson@lbl.gov; Blakely, E.A.; Bjornstad, K.A. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States); Chang, P.Y. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States); SRI International, Menlo Park, CA (United States); Rosen, C.J.; Schwarz, R.I. [Division of Life Sciences, Lawrence Berkeley National Laboratory, Bld. 50A-6120, Berkeley, CA 94720 (United States)

    2007-11-11

    Synchrotron X-ray sources enable radiation biology experiments that are difficult with conventional sources. A synchrotron source can easily deliver a monochromatic, tunable energy, highly collimated X-ray beam of well-calibrated intensity. An exposure station at beamline 10.3.1 of the Advanced Light Source (ALS) has been developed which delivers a variable energy (5-20 keV) X-ray fan beam with very sharp edges (10-90% in less than 3 {mu}m). A series of experiments have been done with a four-well slide where a stripe (100 {mu}m widex18 mm long) of cells in each well has been irradiated and the dose varied from well to well. With this facility we have begun a series of experiments to study cells adjacent to irradiated cells and how they respond to the damage of their neighbors. Initial results have demonstrated the advantages of using synchrotron radiation for these experiments.

  4. Cytogenetic measurements of the relative biological effectiveness of tritium

    International Nuclear Information System (INIS)

    Chopra, C.; Heddle, J.A.

    1988-10-01

    Chromosome aberrations in peripheral blood lymphocytes, which are used to estimate radiation dose biologically, were induced by tritium 1.14 times as effectively as X-rays (95% confidence limits: 0.8 - 1.5). Chromosome translocations in spermatogonia, which are one component of genetic risk, were induced by tritium 1.21 times as effectively as X-rays (95% confidence limits: 0.8 -1.9). All experimental measurements were made in CBA/H mice injected with tritiated water or exposed to X-rays at a comparable dose rate

  5. Biological effects of ionizing radiation - changing worker attitudes

    International Nuclear Information System (INIS)

    Johnson, N.; Schenley, C.

    1989-01-01

    Training Resources and Data Exchange (TRADE) Radiation Protection Training Special Interest Group has taken an innovative approach to providing DOE contractors with radiation worker training material information. Newly-hired radiation workers may be afraid to work near radiation and long-term radiation workers may become indifferent to the biological hazard of radiation. Commercially available training material is often presented at an inappropriate technical level or in an uninteresting style. These training problems have been addressed in the DOE system through development of a training videotape and supporting material package entitled Understanding Ionizing Radiation and its Biological Effects. The training package, developed and distributed by TRADE specifically to meet the needs of DOE contractor facilities, contains the videotape and accompanying paper supporting materials designed to assist the instructor. Learning objectives, presentation suggestion for the instructor, trainee worksheets, guided discussion questions, and trainee self-evaluation sheets are included in the training package. DOE contractors have agreed that incorporating this training module into radiation worker training programs enhances the quality of the training and increase worker understanding of the biological effects of ionizing radiation

  6. Nuclear effects in neutrino oscillation experiments

    International Nuclear Information System (INIS)

    Chauhan, S.; Athar, M. Sajjad; Singh, S. K.

    2011-01-01

    We have studied the nuclear medium effects in the neutrino(antineutrino) induced interactions in nuclei which are relevant for present neutrino oscillation experiments in the few GeV energy region. The study is specially focused on calculating the cross sections and the event rates for atmospheric and accelerator neutrino experiments. The nuclear effects are found to be important for the quasielastic lepton production and the charged current incoherent and coherent pion production processes.

  7. Landing in the future: Biological experiments on Earth and in space orbit

    Science.gov (United States)

    Pokrovskiy, A.

    1980-01-01

    The development of an Earth biosatellite to duplicate the parameters of pressure, temperature, humidity and others in a space environment onboard Cosmos-1129 is discussed. Effects of a space environment on fruit flies, dogs, laboratory rats in procreation, behavior, stress, biorhythm, body composition, gravitation preference, and cell cultures are examined. The space environment for agricultural products is also studied. The effects of heavy nuclei of galactic space radiation on biological objects inside and outside the satellite is studied, and methods of electrostatic protection are developed.

  8. Landing in the future: Biological experiments on Earth and in space orbit

    Science.gov (United States)

    Pokrovskiy, A.

    1980-09-01

    The development of an Earth biosatellite to duplicate the parameters of pressure, temperature, humidity and others in a space environment onboard Cosmos-1129 is discussed. Effects of a space environment on fruit flies, dogs, laboratory rats in procreation, behavior, stress, biorhythm, body composition, gravitation preference, and cell cultures are examined. The space environment for agricultural products is also studied. The effects of heavy nuclei of galactic space radiation on biological objects inside and outside the satellite is studied, and methods of electrostatic protection are developed.

  9. Estimation of biological effects of phytocenosis radioactive contamination

    International Nuclear Information System (INIS)

    Suvorova, L.I.; Smirnov, E.G.; Shejn, G.N.

    1990-01-01

    Biological effects of argicultural field contamination in the Chernobyl NPP 30-km zone in the period of 1986-1988 are studies. Depth of some kings of herbs is noted in spite of natural phytocenosis high stability. It is revealed that increased mutageneous effect is observed for seeds from phytocenosis subjected to radiation factor effects. The genetic radiation effects at cell level will be observed in the nearest years as the radiation factor will not disappear in the 30-km zone (chronic irradiation of plants in the dose range from 0.1x10 -4 up to 0.1 Gy/day). These injuries visually will not effect greatly on natural populations

  10. Knudsen effects in a Scott effect experiment.

    Science.gov (United States)

    Wells, C. W.; Wood, L. T.; Hildebrandt, A. F.

    1973-01-01

    A thermal torque sometimes observed in Scott effect measurements has been studied experimentally and an explanation for the thermal torque proposed. The magnitude of the thermal torque can be comparable to the Scott torque depending on geometrical and thermal anisotropies. The thermal torque is predicted to decrease with application of an axial magnetic field.

  11. Seyle’s biological stressors influence dramatically skin physiology: our experiences with electrical admittance magnitude measurements

    Directory of Open Access Journals (Sweden)

    Lorenzo Martini

    2014-04-01

    Full Text Available Introduction: Abrupt changes of environmental temperatures and assault of chemical and physical assaults belong to the series of biological stresses recorded by the austro-canadian endocrinologist Seyle onto skin, phenomena that are progressively overset all natural events and anthropological lifestyles, are too often depreciated and underestimated by dermatologists and cosmetologists at all. Aims of our study is to evaluate by electrical admittance magnitude measurements the influence these two irrefutable afflictions, designed as stressors, influence negatively human skin and to do this we have selected, to conduct the study, peculiar individuals that, owing to their choice of living, may or not be injured by extreme changes of temperatures and aggressions by chemical and physical pollutants. Materials and Methods: We have recruited 20 nuns in a cloistered convent in Mid Italy: ten of these have been always accustomed to live inside the cloister and their life-style permits the good conservation of the intact skin physiology (that is living at air temperature and medium-low relative humidity and the other ten are accustomed to live and work outdoor and to be assaulted by abrupt and extreme changes of environmental temperature and pollutants. Cloistered nuns have the chance to choose where to live, indoor or aoutdoor. We measured the electrical admittance magnitude (in μmho at the beginning and at the end of the experiment that lasts 29 weeks, using an appropriate instrument based on the system developed by Feldman, working at a single frequency of 30kHz. Results and Conclusion: It is self evident that after the simulation of phyto-induced cortisol release onto the skins of all the 20 volunteers, the subjects that which live outdoor show an exaggerated value of dehydration with regard to the subjects that live indoor. Changes of environmental temperatures and chemical pollutants, is self evident, jeopardize human skin integrity and safety, but

  12. The Effects Of Physical And Biological Cohesion On Bedforms

    Science.gov (United States)

    Parsons, D. R.; Schindler, R.; Baas, J.; Hope, J. A.; Malarkey, J.; Paterson, D. M.; Peakall, J.; Manning, A. J.; Ye, L.; Aspden, R.; Alan, D.; Bass, S. J.

    2014-12-01

    Most coastal sediments consist of complex mixtures of cohesionless sands, physically-cohesive clays and extra cellular polymeric substances (EPS) that impart biological cohesion. Yet, our ability to predict bedform dimensions in these substrates is reliant on predictions based exclusively on cohesionless sand. We present findings from the COHBED project - which explicitly examines how bedform dynamics are modified by natural cohesion. Our experimental results show that for ripples, height and length are inversely proportional to initial clay content and bedforms take longer to appear, with no ripples when clay content exceeds 18%. When clay is replaced by EPS the development time and time of first appearance of ripples both increase by two orders of magnitude, with no bedforms above 0.125% EPS. For dunes, height and length are also inversely proportional to initial substrate clay content, resulting in a transition from dunes to ripples normally associated with velocity decreases. Addition of low EPS concentrations into the substrate results in yet smaller bedforms at the same clay contents and at high EPS concentrations, biological cohesion supersedes all electrostatic bonding, and bedform size is no longer related to mud content. The contrast in physical and biological cohesion effects on bedform development result from the disparity between inter-particle electrostatic bonding of clay particles and EPS grain coating and strands that physically link sediments together, which effects winnowing rates as bedforms evolve. These findings have wide ranging implications for bedform predictions in both modern and ancient environments. Coupling of biological and morphological processes not only requires an understanding of how bedform dimensions influence biota and habitat, but also how benthic species can modify bedform dimensions. Consideration of both aspects provides a means in which fluid dynamics, sediment transport and ecosystem energetics can be linked to yield

  13. The effect of teaching methods on cognitive achievement, retention, and attitude among in biology studying

    Directory of Open Access Journals (Sweden)

    Snezana Stavrova Veselinovskaa

    2011-12-01

    Full Text Available The purpose of this paper is to determine the effects of usage of sequential teaching method on the academic achievement and retention level of students. Three student groups of biology students in University “Goce Delcev”, Faculty of Natural and Technical Sciences, Institute of Biology, - Stip, R. Macedonia were offered a topic on general characteristics of Proteins: Their Biological Functions and Primary Structure with different sequences of 3 teaching methods. The teaching methods were Laboratory method (student experiment, slide demonstration and lecture method. The first group started to course with experiments in the laboratory, then the relevant theory of proteins was given lecture method, and then the slides was shown (Group I. The sequence of these three teaching methods used in the first group was changed in both second and third group as follow: The lecture methods, slide show and experiment in Group II, and slide show, experiment and lecture method in Group III, respectively. Laboratory method used in the study was focused on the topic of this diversity and abundance reflect the central role of proteins in virtually all aspects of cell structure and function. Achievement test contained 20 questions, testing the knowledge of facts as well as the ability to transfer the knowledge and problem solving ability. This test was used as pre-test before methods’ application, post-test after the methods’ application and retention test after 30 days from methods’ applied.

  14. Pilot scale experiment with MBR operated in intermittent aeration condition: analysis of biological performance.

    Science.gov (United States)

    Capodici, M; Di Bella, G; Di Trapani, D; Torregrossa, M

    2015-02-01

    The effect of intermittent aeration (IA) on a MBR system was investigated. The study was aimed at analyzing different working conditions and the influence of different IA cycles on the biological performance of the MBR pilot plant, in terms of organic carbon and ammonium removal as well as extracellular polymeric substances (EPSs) production. The membrane modules were placed in a separate compartment, continuously aerated. This configuration allowed to disconnect from the filtration stage the biological phenomena occurring into the IA bioreactor. The observed results highlighted good efficiencies, in terms of organic carbon and ammonium removal. It was noticed a significant soluble microbial products (SMPs) release, likely related to the higher metabolic stress that anoxic conditions exerted on the biomass. However, the proposed configuration, with the membranes in a separate compartment, allowed to reduce the EPSs in the membrane tank even during the non-aerated phase, thus lowering fouling development. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Biological effectiveness of high-energy protons - Target fragmentation

    International Nuclear Information System (INIS)

    Cucinotta, F.A.; Katz, R.; Wilson, J.W.; Townsend, L.W.; Shinn, J.; Hajnal, F.

    1991-01-01

    High-energy protons traversing tissue produce local sources of high-linear-energy-transfer ions through nuclear fragmentation. The contribution of these target fragments to the biological effectiveness of high-energy protons using the cellular track model is examined. The effects of secondary ions are treated in terms of the production collision density using energy-dependent parameters from a high-energy fragmentation model. Calculations for mammalian cell cultures show that at high dose, at which intertrack effects become important, protons deliver damage similar to that produced by gamma rays, and with fragmentation the relative biological effectiveness (RBE) of protons increases moderately from unity. At low dose, where sublethal damage is unimportant, the contribution from target fragments dominates, causing the proton effectiveness to be very different from that of gamma rays with a strongly fluence-dependent RBE. At high energies, the nuclear fragmentation cross sections become independent of energy. This leads to a plateau in the proton single-particle-action cross section, below 1 keV/micron, since the target fragments dominate. 29 refs

  16. Chemometric and biological validation of a capillary electrophoresis metabolomic experiment of Schistosoma mansoni infection in mice.

    Science.gov (United States)

    Garcia-Perez, Isabel; Angulo, Santiago; Utzinger, Jürg; Holmes, Elaine; Legido-Quigley, Cristina; Barbas, Coral

    2010-07-01

    Metabonomic and metabolomic studies are increasingly utilized for biomarker identification in different fields, including biology of infection. The confluence of improved analytical platforms and the availability of powerful multivariate analysis software have rendered the multiparameter profiles generated by these omics platforms a user-friendly alternative to the established analysis methods where the quality and practice of a procedure is well defined. However, unlike traditional assays, validation methods for these new multivariate profiling tools have yet to be established. We propose a validation for models obtained by CE fingerprinting of urine from mice infected with the blood fluke Schistosoma mansoni. We have analysed urine samples from two sets of mice infected in an inter-laboratory experiment where different infection methods and animal husbandry procedures were employed in order to establish the core biological response to a S. mansoni infection. CE data were analysed using principal component analysis. Validation of the scores consisted of permutation scrambling (100 repetitions) and a manual validation method, using a third of the samples (not included in the model) as a test or prediction set. The validation yielded 100% specificity and 100% sensitivity, demonstrating the robustness of these models with respect to deciphering metabolic perturbations in the mouse due to a S. mansoni infection. A total of 20 metabolites across the two experiments were identified that significantly discriminated between S. mansoni-infected and noninfected control samples. Only one of these metabolites, allantoin, was identified as manifesting different behaviour in the two experiments. This study shows the reproducibility of CE-based metabolic profiling methods for disease characterization and screening and highlights the importance of much needed validation strategies in the emerging field of metabolomics.

  17. Biological effects of high strength electric fields. Second interim progress report, September 1976--March 1977

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, R.D.; Kaune, W.T.

    1977-05-01

    This report describes progress made on the Project during the period of September 9, 1976 to March 31, 1977 towards the determination of the biological effects of high strength electric fields on small laboratory animals. The efforts to date can be divided into five categories: (1) the design, construction, and testing of a prototype and special studies exposure system; (2) the design and construction of exposure systems for rats and mice; (3) dosimetry; (4) experiments to determine the maximum field strength which does not produce corona discharge, ozone formation, shocks to the animal, hair stimulation, or a behavioral preference by rats to avoid exposure to the field; and (5) preparations for the biological screening experiments.

  18. Far infrared radiation (FIR): its biological effects and medical applications.

    Science.gov (United States)

    Vatansever, Fatma; Hamblin, Michael R

    2012-11-01

    Far infrared (FIR) radiation (λ = 3-100 μm) is a subdivision of the electromagnetic spectrum that has been investigated for biological effects. The goal of this review is to cover the use of a further sub-division (3- 12 μm) of this waveband, that has been observed in both in vitro and in vivo studies, to stimulate cells and tissue, and is considered a promising treatment modality for certain medical conditions. Technological advances have provided new techniques for delivering FIR radiation to the human body. Specialty lamps and saunas, delivering pure FIR radiation (eliminating completely the near and mid infrared bands), have became safe, effective, and widely used sources to generate therapeutic effects. Fibers impregnated with FIR emitting ceramic nanoparticles and woven into fabrics, are being used as garments and wraps to generate FIR radiation, and attain health benefits from its effects.

  19. Leveraging organismal biology to forecast the effects of climate change.

    Science.gov (United States)

    Buckley, Lauren B; Cannistra, Anthony F; John, Aji

    2018-04-26

    Despite the pressing need for accurate forecasts of ecological and evolutionary responses to environmental change, commonly used modelling approaches exhibit mixed performance because they omit many important aspects of how organisms respond to spatially and temporally variable environments. Integrating models based on organismal phenotypes at the physiological, performance and fitness levels can improve model performance. We summarize current limitations of environmental data and models and discuss potential remedies. The paper reviews emerging techniques for sensing environments at fine spatial and temporal scales, accounting for environmental extremes, and capturing how organisms experience the environment. Intertidal mussel data illustrate biologically important aspects of environmental variability. We then discuss key challenges in translating environmental conditions into organismal performance including accounting for the varied timescales of physiological processes, for responses to environmental fluctuations including the onset of stress and other thresholds, and for how environmental sensitivities vary across lifecycles. We call for the creation of phenotypic databases to parameterize forecasting models and advocate for improved sharing of model code and data for model testing. We conclude with challenges in organismal biology that must be solved to improve forecasts over the next decade.acclimation, biophysical models, ecological forecasting, extremes, microclimate, spatial and temporal variability.

  20. Health and biological effects of non-ionizing radiations

    International Nuclear Information System (INIS)

    De Seze, R.; Souques, M.; Aurengo, A.; Bach, V.; Burais, N.; Cesarini, J.P.; Cherin, A.; Decobert, V.; Dubois, G.; Hours, M.; Lagroye, I.; Leveque, Ph.; Libert, J.P.; Lombard, J.; Loos, N.; Mir, L.; Perrin, A.; Poulletier De Gannes, F.; Thuroczy, G.; Wiart, J.; Lehericy, St.; Pelletier, A.; Marc-Vergnes, J.P.; Douki, Th.; Guibal, F.; Tordjman, I.; Gaillot de Saintignon, J.; Collard, J.F.; Scoretti, R.; Magne, I.; Veyret, B.; Katrib, J.

    2011-01-01

    This document gathers the slides of the available presentations given during this conference day on the biological and health effects of non-ionizing radiations. Sixteen presentations out of 17 are assembled in the document and deal with: 1 - NMR: biological effects and implications of Directive 2004/40 on electromagnetic fields (S. Lehericy); 2 - impact of RF frequencies from mobile telephone antennas on body homeostasis (A. Pelletier); 3 - expression of stress markers in the brain and blood of rats exposed in-utero to a Wi-Fi signal (I. Lagroye); 4 - people exposure to electromagnetic waves: the challenge of variability and the contribution of statistics to dosimetry (J. Wiart); 5 - status of knowledge about electromagnetic fields hyper-sensitivity (J.P. Marc-Vergnes; 6 - geno-toxicity of UV radiation: respective impact of UVB and UVA (T. Douki); 7 - National day of prevention and screening for skin cancers (F. Guibal); 8 - UV tan devices: status of knowledge about cancer risks (I. Tordjman, and J. Gaillot de Saintignon); 9 - modulation of brain activity during a tapping task after exposure to a 3000 μT magnetic field at 60 Hz (M. Souques and A. Legros); 10 - calculation of ELF electromagnetic fields in the human body by the finite elements method (R. Scoretti); 11 - French population exposure to the 50 Hz magnetic field (I. Magne); 12 - LF and static fields, new ICNIRP recommendations: what has changed, what remains (B. Veyret); 13 - risk assessment of low energy lighting systems - DELs and CFLs (J.P. Cesarini); 14 - biological effects to the rat of a chronic exposure to high power microwaves (R. De Seze); 15 - theoretical and experimental electromagnetic compatibility approaches of active medical implants in the 10-50 Hz frequency range: the case of implantable cardiac defibrillators (J. Katrib); French physicians and electromagnetic fields (M. Souques). (J.S.)

  1. Micro-scale NMR Experiments for Monitoring the Optimization of Membrane Protein Solutions for Structural Biology.

    Science.gov (United States)

    Horst, Reto; Wüthrich, Kurt

    2015-07-20

    Reconstitution of integral membrane proteins (IMP) in aqueous solutions of detergent micelles has been extensively used in structural biology, using either X-ray crystallography or NMR in solution. Further progress could be achieved by establishing a rational basis for the selection of detergent and buffer conditions, since the stringent bottleneck that slows down the structural biology of IMPs is the preparation of diffracting crystals or concentrated solutions of stable isotope labeled IMPs. Here, we describe procedures to monitor the quality of aqueous solutions of [ 2 H, 15 N]-labeled IMPs reconstituted in detergent micelles. This approach has been developed for studies of β-barrel IMPs, where it was successfully applied for numerous NMR structure determinations, and it has also been adapted for use with α-helical IMPs, in particular GPCRs, in guiding crystallization trials and optimizing samples for NMR studies (Horst et al ., 2013). 2D [ 15 N, 1 H]-correlation maps are used as "fingerprints" to assess the foldedness of the IMP in solution. For promising samples, these "inexpensive" data are then supplemented with measurements of the translational and rotational diffusion coefficients, which give information on the shape and size of the IMP/detergent mixed micelles. Using microcoil equipment for these NMR experiments enables data collection with only micrograms of protein and detergent. This makes serial screens of variable solution conditions viable, enabling the optimization of parameters such as the detergent concentration, sample temperature, pH and the composition of the buffer.

  2. Experience of an inter-laboratory exercise for the determination of Carbon-14 in biological samples

    International Nuclear Information System (INIS)

    Baburajan, A.; Rajaram, S.; D'Souza, Renita Shiny; Nayak, Rasmi; Karunakara, N.; Ravi, P.M.; Tripathi, R.M.

    2018-01-01

    Carbon-14 is one of the naturally occurring cosmogenic nuclide with long half life of 5730 y and beta energy, E max : 156 keV produced continuously in the outer atmosphere. It is also produced by the anthropogenic activities like nuclear weapon test, nuclear power plant etc. contributing to the atmospheric inventory. The 14 CO 2 gets incorporated with the plant species during photosynthesis and ultimately reaches to man through food chain. It is important to accurately quantify the level of 14 C in different biological matrices for the computation of radiation dose due to ingestion. There are different methods available for the determination of 14 C in biological samples. The oxidation of the dried sample is one of the methods used for liberating the 14 CO 2 and which in turn re-absorbed using Carbo Sorb and subjected to Liquid scintillation analyses with Permaflour scintillator solution. The paper deals with the quality assurance programme initiated by ESL, Tarapur along with ESL, Kalpakkam and CARER, Mangalore University and share the experience of the inter-laboratory comparison exercise

  3. Semi-automated operation of Mars Climate Simulation chamber - MCSC modelled for biological experiments

    Science.gov (United States)

    Tarasashvili, M. V.; Sabashvili, Sh. A.; Tsereteli, S. L.; Aleksidze, N. D.; Dalakishvili, O.

    2017-10-01

    The Mars Climate Simulation Chamber (MCSC) (GEO PAT 12 522/01) is designed for the investigation of the possible past and present habitability of Mars, as well as for the solution of practical tasks necessary for the colonization and Terraformation of the Planet. There are specific tasks such as the experimental investigation of the biological parameters that allow many terrestrial organisms to adapt to the imitated Martian conditions: chemistry of the ground, atmosphere, temperature, radiation, etc. MCSC is set for the simulation of the conduction of various biological experiments, as well as the selection of extremophile microorganisms for the possible Settlement, Ecopoesis and/or Terraformation purposes and investigation of their physiological functions. For long-term purposes, it is possible to cultivate genetically modified organisms (e.g., plants) adapted to the Martian conditions for future Martian agriculture to sustain human Mars missions and permanent settlements. The size of the chamber allows preliminary testing of the functionality of space-station mini-models and personal protection devices such as space-suits, covering and building materials and other structures. The reliability of the experimental biotechnological materials can also be tested over a period of years. Complex and thorough research has been performed to acquire the most appropriate technical tools for the accurate engineering of the MCSC and precious programmed simulation of Martian environmental conditions. This paper describes the construction and technical details of the equipment of the MCSC, which allows its semi-automated, long-term operation.

  4. A Review: Some biological effects of high LET radiations

    Science.gov (United States)

    Wiley, A., Jr.

    1972-01-01

    There are qualitative and quantitative differences in the biological damage observed after exposure to high LET radiation as compared to that caused by low LET radiations. This review is concerned with these differences, which are ultimately reflected at the biochemical, cellular and even whole animal levels. In general, high LET radiations seem to produce biochemical damage which is more severe and possibly less repairable. Experimental data for those effects are presented in terms of biochemical RBE's with consideration of both early and late manifestations. An LET independent process by which significant biochemical damage may result from protons, neutrons and negative pion mesons is discussed.

  5. Effective Elastic Modulus of Structured Adhesives: From Biology to Biomimetics

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2017-06-01

    Full Text Available Micro- and nano-hierarchical structures (lamellae, setae, branches, and spatulae on the toe pads of many animals play key roles for generating strong but reversible adhesion for locomotion. The hierarchical structure possesses significantly reduced, effective elastic modulus (Eeff, as compared to the inherent elastic modulus (Einh of the corresponding biological material (and therefore contributes to a better compliance with the counterpart surface. Learning from nature, three types of hierarchical structures (namely self-similar pillar structure, lamella–pillar hybrid structure, and porous structure have been developed and investigated.

  6. Dynamic cell culture system: a new cell cultivation instrument for biological experiments in space

    Science.gov (United States)

    Gmunder, F. K.; Nordau, C. G.; Tschopp, A.; Huber, B.; Cogoli, A.

    1988-01-01

    The prototype of a miniaturized cell cultivation instrument for animal cell culture experiments aboard Spacelab is presented (Dynamic cell culture system: DCCS). The cell chamber is completely filled and has a working volume of 200 microliters. Medium exchange is achieved with a self-powered osmotic pump (flowrate 1 microliter h-1). The reservoir volume of culture medium is 230 microliters. The system is neither mechanically stirred nor equipped with sensors. Hamster kidney (Hak) cells growing on Cytodex 3 microcarriers were used to test the biological performance of the DCCS. Growth characteristics in the DCCS, as judged by maximal cell density, glucose consumption, lactic acid secretion and pH, were similar to those in cell culture tubes.

  7. Uranium: properties and biological effects after internal contamination

    International Nuclear Information System (INIS)

    Souidi, M.; Tissandie, E.; Racine, R.; Ben Soussan, H.; Rouas, C.; Grignard, E.; Dublineau, I.; Gourmelon, P.; Lestaevel, P.; Gueguen, Y.

    2009-01-01

    Uranium is a radionuclide present in the environment since the origin of the Earth. In addition to natural uranium, recent deposits from industrial or military activities are acknowledged. Uranium's toxicity is due to a combination of its chemical (heavy metal) and radiological properties (emission of ionizing radiations). Acute toxicity induces an important weight loss and signs of renal and cerebral impairment. Alterations of bone growth, modifications of the reproductive system and carcinogenic effects are also often seen. On the contrary, the biological effects of a chronic exposure to low doses are unwell known. However, results from different recent studies suggest that a chronic contamination with low levels of uranium induces subtle but significant levels. Indeed, an internal contamination of rats for several weeks leads to detection of uranium in many cerebral structures, in association with an alteration of short-term memory and an increase of anxiety level. Biological effects of uranium on the metabolisms of xenobiotics, steroid hormones and vitamin D were described in the liver, testis and kidneys. These recent scientific data suggest that uranium could participate to increase of health risks linked to environmental pollution. (authors)

  8. Biological effects and medical applications of infrared radiation.

    Science.gov (United States)

    Tsai, Shang-Ru; Hamblin, Michael R

    2017-05-01

    Infrared (IR) radiation is electromagnetic radiation with wavelengths between 760nm and 100,000nm. Low-level light therapy (LLLT) or photobiomodulation (PBM) therapy generally employs light at red and near-infrared wavelengths (600-100nm) to modulate biological activity. Many factors, conditions, and parameters influence the therapeutic effects of IR, including fluence, irradiance, treatment timing and repetition, pulsing, and wavelength. Increasing evidence suggests that IR can carry out photostimulation and photobiomodulation effects particularly benefiting neural stimulation, wound healing, and cancer treatment. Nerve cells respond particularly well to IR, which has been proposed for a range of neurostimulation and neuromodulation applications, and recent progress in neural stimulation and regeneration are discussed in this review. The applications of IR therapy have moved on rapidly in recent years. For example, IR therapy has been developed that does not actually require an external power source, such as IR-emitting materials, and garments that can be powered by body heat alone. Another area of interest is the possible involvement of solar IR radiation in photoaging or photorejuvenation as opposites sides of the coin, and whether sunscreens should protect against solar IR? A better understanding of new developments and biological implications of IR could help us to improve therapeutic effectiveness or develop new methods of PBM using IR wavelengths. Copyright © 2016. Published by Elsevier B.V.

  9. Review: Bioenergetic Fields and Their Biologic Effects Mechanism

    Directory of Open Access Journals (Sweden)

    Zahra Movaffaghi

    2007-04-01

    Full Text Available As interests in complementary and alternative medicine grows, the scientists are looking forward in researches which determine the mechanisms in which they exert their effectiveness. Some of these modalities like Yoga, Acupuncture, and especially other bio-field therapies such as none contact therapeutic touch, affects the bio-field which spreads throughout the body and into the space around it. According to physic’s law, when electricity flows throw the living tissues, like what happens in our heart and brain, biomagnetic fields are being induced in the surrounding space. Beside that moving charges like ions and free radicals which finally produce electromagnetic fields. Using very sensitive magnetometers, biomagnetic fields have been detected and get amplified up to 1000 times by meditation. This phenomenon could be the basis for most of most complementaty therapeutic approaches like therapeutic touch. On the other hand the electrical, magnetic and bio-magnetic fields have a well known application in conventional medicine. Modern research about bio-magnetism and magneto-biology suggests that in term of both aspects, the effects and the mechanisms for all the different looking modalities used in conventional medicine and complementary medicine which have commons in their fundamentals. This article reviews some of the recent works on biological effects of natural or artificial electromagnetic fields.

  10. Relative biological effectiveness and radiation weighting factors in the context of animals and plants

    International Nuclear Information System (INIS)

    Higley, K.A.; Kocher, D.C.; Real, A.G.; Chambers, D.B.

    2012-01-01

    Radiation weighting factors have long been employed to modify absorbed dose as part of the process of evaluating radiological impact to humans. Their use represents an acknowledgement of the fundamental difference in energy deposition patterns of charged and uncharged particles, and how this can translate into varying degrees of biological impact. Weighting factors used in human radiation protection are derived from a variety of endpoints taken from in-vitro experiments that include human and animal cell lines, as well as in-vivo experiments with animals. Nonetheless, the application of radiation weighting factors in the context of dose assessment of animals and plants is not without some controversy. Specifically, radiation protection of biota has largely focused on limiting deterministic effects, such as reduced reproductive fitness. Consequently, the application of conventional stochastic-based radiation weighting factors (when used for human protection) appears inappropriate. While based on research, radiation weighting factors represent the parsing of extensive laboratory studies on relative biological effectiveness. These studies demonstrate that the magnitude of a biological effect depends not just on dose, but also on other factors including the rate at which the dose is delivered, the type and energy of the radiation delivering the dose, and, most importantly, the endpoint under consideration. This article discusses the efforts taken to develop a logical, transparent, and defensible approach to establishing radiation weighting factors for use in assessing impact to non-human biota, and the challenges found in differentiating stochastic from deterministic impacts.

  11. The disposition effect and investor experience

    OpenAIRE

    Da Costa Jr, Newton; Goulart, Marco; Cupertino, Cesar; Macedo Jr, Jurandir; Da Silva, Sergio

    2013-01-01

    We examine whether investing experience can dampen the disposition effect, that is, the fact that investors seem to hold on to their losing stocks to a greater extent than they hold on to their winning stocks. To do so, we devise a computer program that simulates the stock market. We use the program in an experiment with two groups of subjects, namely experienced investors and undergraduate students (the inexperienced investors). As a control procedure, we consider random trade decisions made...

  12. ARADISH - Development of a Standardized Plant Growth Chamber for Experiments in Gravitational Biology Using Ground Based Facilities

    Science.gov (United States)

    Schüler, Oliver; Krause, Lars; Görög, Mark; Hauslage, Jens; Kesseler, Leona; Böhmer, Maik; Hemmersbach, Ruth

    2016-06-01

    Plant development strongly relies on environmental conditions. Growth of plants in Biological Life Support Systems (BLSS), which are a necessity to allow human survival during long-term space exploration missions, poses a particular problem for plant growth, as in addition to the traditional environmental factors, microgravity (or reduced gravity such as on Moon or Mars) and limited gas exchange hamper plant growth. Studying the effects of reduced gravity on plants requires real or simulated microgravity experiments under highly standardized conditions, in order to avoid the influence of other environmental factors. Analysis of a large number of biological replicates, which is necessary for the detection of subtle phenotypical differences, can so far only be achieved in Ground Based Facilities (GBF). Besides different experimental conditions, the usage of a variety of different plant growth chambers was a major factor that led to a lack of reproducibility and comparability in previous studies. We have developed a flexible and customizable plant growth chamber, called ARAbidopsis DISH (ARADISH), which allows plant growth from seed to seedling, being realized in a hydroponic system or on Agar. By developing a special holder, the ARADISH can be used for experiments with Arabidopsis thaliana or a plant with a similar habitus on common GBF hardware, including 2D clinostats and Random Positioning Machines (RPM). The ARADISH growth chamber has a controlled illumination system of red and blue light emitting diodes (LED), which allows the user to apply defined light conditions. As a proof of concept we tested a prototype in a proteomic experiment in which plants were exposed to simulated microgravity or a 90° stimulus. We optimized the design and performed viability tests after several days of growth in the hardware that underline the utility of ARADISH in microgravity research.

  13. Biological activity of selected plants with adaptogenic effect

    Directory of Open Access Journals (Sweden)

    Eva Ivanišová

    2016-05-01

    Full Text Available The aim of this study was to determine biological activity of plants with adaptogenic effect: Panax ginseng Mayer., Withania somnifera L., Eleuterococcus senticosus Rupr. et Maxim., Astragallus membranaceus Fisch. and Codonopsis pilosulae Franch. The antioxidant activity was detected by DPPH and phosphomolybdenum method, total polyphenol content with Folin – Ciocalteu reagent, flavonoids content by aluminium chloride method. The detection of antimicrobial activity was carried out by disc diffusion method against three species of Gram-negative bacteria: Escherichia coli CCM 3988, Salmonella enterica subsp. enterica CCM 3807, Yersinia enterocolitica CCM 5671 and two Gram-positive bacteria: Bacillus thuringiensis CCM 19, Stapylococcus aureus subsp. aureus CCM 2461. Results showed that plants with adaptogenic effect are rich for biologically active substances. The highest antioxidant activity by DPPH method was determined in the sample of Eleuterococcus senticosus (3.15 mg TEAC – Trolox equivalent antioxidant capacity per g of sample and by phosphomolybdenum method in the sample of Codonopsis pilosulae (188.79 mg TEAC per g of sample. In the sample of Panax ginseng was measured the highest content of total polyphenols (8.10 mg GAE – galic acid equivalent per g of sample and flavonoids (3.41 μg QE – quercetin equivalent per g of sample. All samples also showed strong antimicrobial activity with the best results in Panax ginseng and Withania somnifera in particular for species Yersinia enterocolitica CCM 5671 and Salmonella enterica subsp. enterica CCM 3807. The analyzed species of plant with high value of biological activity can be used more in the future, not only in food, but also in cosmetics and pharmaceutical industries.

  14. Biological effects induced by K photo-ionisation in and near constituent atoms of DNA

    International Nuclear Information System (INIS)

    Touati, A.; Herve du Penhoot, M.A.; Fayard, B.; Champion, C.; Abel, F.; Gobert, F.; Lamoureux, M.; Politis, M.F.; Martins, L.; Ricoul, M.; Sabatier, L.; Sage, E.; Chetioui, A.

    2002-01-01

    In order to assess the lethal efficiency and other biological effects of inner shell ionisations of constituent atoms of DNA ('K' events), experiments were developed at the LURE synchrotron facility using ultrasoft X rays as a probe of K events. The lethal efficiency of ultrasoft X rays above the carbon K threshold was especially investigated using V79 cells and compared with their efficiency to induce double strand breaks in dry plasmid-DNA. A correlation between the K event efficiencies for these processes is shown. Beams of 340 eV were found to be twice as efficient at killing cells than were beams at 250 eV. In addition, a rough two-fold increase of the relative biological effectiveness for dicentric+ring induction has also been observed between 250 and 340 eV radiations. (author)

  15. Biological effects of 137Cs, incorporated into organism of rats

    International Nuclear Information System (INIS)

    Monakhov, A.S.; Strekalov, S.A.; Sokolov, A.V.; Aver'yanova, T.K.

    1987-01-01

    Results of investigating mutagenous and hemotoxic effects of 137 Cs on blood lymphocytes of rats are presented. 137 Cs was orally administrated into organism of rats as 270 kBq/g chloride solution. 137 Cs mutagenous effect was studied on metaphase plates of rat blood lymphocytes in course of rats lifetime experiment. It is stated that 137 Cs inducing severe disturbances of genetic material in a great quantity of blood lymphocytes, causes their total killing

  16. Effects of temperature on biological activity of permafrost microorganisms.

    Science.gov (United States)

    Kalyonova, L F; Novikova, M A; Subbotin, A M; Bazhin, A S

    2015-04-01

    The number and viability of microorganism specimens Bacillus spp. isolated from permafrost soil remained unchanged after incubation at temperatures of -16-37°C. Experiments on F1 CBA/Black-6 mice showed that incubation of bacteria at -5°C for 72 h promotes a decrease in their toxicity and an increase in their immunostimulating effect.

  17. The biological effects of radium-224 injected into dogs

    International Nuclear Information System (INIS)

    Muggenburg, B.A.; Hahn, F.F.; Boecker, B.B.

    1996-01-01

    A life-span study was conducted in 128 beagle dogs to determine the biological effects of intravenously injected 224 Ra chloride. The 224 Ra chloride was prepared by the same method used for intravenous injections in humans who were treated for ankylosing spondylitis and tuberculosis. Thus the results obtained from dogs can be compared directly to the population of treated humans, both for the elucidation of the effect of exposure rate and for comparison with other radionuclides for which data for humans are unavailable. Using equal numbers of males and females, the dogs were injected with one of four levels of 224 Ra resulting in initial body burdens of approximately 13, 40, 120 or 350 kBq of 224 Ra kg -1 body mass. A control group of dogs was injected with diluent only. All dogs were divided further into three groups for which the amount of injected 224 Ra (half-life of 3.62 days) or diluent was given in a single injection or divided equally into 10 or 50 weekly injections. As a result of these three injection schedules, the accumulation of dose from the injected 224 Ra was distributed over approximately 1, 3 or 12 months. Each injection schedule included four different injection levels resulting in average absorbed α-particle doses to bone of 0.1, 0.3, 1 and 3 Gy, respectively. The primary early effect observed was a hematological dyscrasia in the dogs receiving either of the two highest injection levels. The effect was most severe in the dogs receiving a single injection of 224 Ra and resulted in the death of three dogs injected at the highest level. The late-occurring biological effects were tumors. Bone tumors were the most common followed by tumors in the nasal mucosa. 52 refs., 8 figs., 8 tabs

  18. BIOLOGICAL EFFECTS OF MICROWAVE RADIATION ON BRAIN TISSUE IN RATS

    Directory of Open Access Journals (Sweden)

    Boris Đinđić

    2003-04-01

    Full Text Available Exposure to microwave radiation induces multiple organ dysfunctions, especially in CNS.The aim of this work was investigation of biological effects of microwave radiation on rats' brain and determination of increased oxidative stress as a possible pathogenetic's mechanism.Wis tar rats 3 months old were divided in experimental (4 female and 4 male animal and control group (5 female and 4 male. This experimental group was constantly exposed to a magnetic field of 5 mG. We simulated using of mobile phones 30 min every day. The source of NIR emitted MF that was similar to mobile phones at 900 MHz. The rats were killed after 2 months. Biological effects were determined by observation of individual and collective behavior and body mass changes. Lipid per oxidation was determined by measuring quantity of malondialdehyde (MDA in brain homogenate.The animals in experimental group exposed to EMF showed les weight gain. The most important observations were changing of basic behavior models and expression of aggressive or panic behavior. The content of MDA in brain tissue is singificantly higher (1.42 times in rats exposed to electromagnetic fields (3,82±0.65 vs. control 2.69±0.42 nmol/mg proteins, p<0.01.Increased oxidative stress and lipid peroxidation after exposition in EM fields induced disorders of function and structure of brain.

  19. Hafnium oxide nanoparticles: toward an in vitro predictive biological effect?

    International Nuclear Information System (INIS)

    Marill, Julie; Anesary, Naeemunnisa Mohamed; Zhang, Ping; Vivet, Sonia; Borghi, Elsa; Levy, Laurent; Pottier, Agnes

    2014-01-01

    Hafnium oxide, NBTXR3 nanoparticles were designed for high dose energy deposition within cancer cells when exposed to ionizing radiation. The purpose of this study was to assess the possibility of predicting in vitro the biological effect of NBTXR3 nanoparticles when exposed to ionizing radiation. Cellular uptake of NBTXR3 nanoparticles was assessed in a panel of human cancer cell lines (radioresistant and radiosensitive) by transmission electron microscopy. The radioenhancement of NBTXR3 nanoparticles was measured by the clonogenic survival assay. NBTXR3 nanoparticles were taken up by cells in a concentration dependent manner, forming clusters in the cytoplasm. Differential nanoparticle uptake was observed between epithelial and mesenchymal or glioblastoma cell lines. The dose enhancement factor increased with increase NBTXR3 nanoparticle concentration and radiation dose. Beyond a minimum number of clusters per cell, the radioenhancement of NBTXR3 nanoparticles could be estimated from the radiation dose delivered and the radiosensitivity of the cancer cell lines. Our preliminary results suggest a predictable in vitro biological effect of NBTXR3 nanoparticles exposed to ionizing radiation

  20. Biological effects of ionizing radiation; Efectos biologicos de la radiacion

    Energy Technology Data Exchange (ETDEWEB)

    Gisone, Pablo; Perez, Maria R [Autoridad Regulatoria Nuclear, Buenos Aires (Argentina)

    2001-07-01

    It has been emphasised the importance of DNA as the main target for ionizing radiation, that can induce damage by its direct action on this molecule or by an indirect effect mediated by free-radicals generated by water radiolysis. Biological effects of ionizing radiation are influenced not only by the dose but also by the dose-rate and the radiation quality. Radiation induced damage, mainly DNA single and double strand breaks, is detected by molecular sensors which in turn trigger signalling cascades leading to cell cycle arrest to allow DNA repair or programmed cell death (apoptosis). Those effects related with cell death, named deterministic, exhibits a dose-threshold below which they are not observed. Acute radiation syndrome and radiological burns are examples of this kind of effects. Other radiation induced effects, called stochastic, are the consequence of cell transformation and do not exhibit a dose-threshold. This is the case of cancer induction and hereditary effects. The aim of this presentation is briefly describe the main aspects of deterministic and stochastic effects from the point of view of radiobiology and radio pathology. (author)

  1. Biological stress reactivity as an index of the two polarities of the experience model.

    Science.gov (United States)

    Silva, Jaime R; Vivanco-Carlevari, Anastassia; Barrientos, Mauricio; Martínez, Claudio; Salazar, Luis A; Krause, Mariane

    2017-10-01

    The two-polarities model of personality argues that experience is organized around two axes: interpersonal relatedness and self-definition. Differential emphasis on one of these poles defines adaptive and pathological experiences, generating anaclitic or introjective tendencies. The anaclitic pattern, on one hand, has been conceptually related with an exaggerated emphasis on interpersonal relatedness. On the other hand, the introjective pattern has been connected to high levels of self-criticism. The aim of this study was to investigate the psychophysiological basis for this relationship. Specifically, we hypothesized that the anaclitic individual should have a higher biological reactivity to stress (BRS), measured by the cortisol concentration in saliva, in an interpersonal stress induction protocol (Trier Social Stress Test). Contrary to what was expected, the results indicated that introjective participants presented a higher BSR than the anaclitic group. Interestingly, in contrast to their higher BSR, the introjective group reported a diminished subjective stress in relation to the average. In the anaclitic group, a tendency that goes in the opposite direction was found. Theoretical implications of these findings were discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Biological interactions and human health effects of static magnetic fields

    International Nuclear Information System (INIS)

    Tenforde, T.S.

    1994-09-01

    Mechanisms through which static magnetic fields interact with living systems will be described and illustrated by selected experimental observations. These mechanisms include electrodynamic interactions with moving ionic charges (blood flow and nerve impulse conduction), magnetomechanical interactions (orientation and translation of molecular structures and magnetic particles), and interactions with electronic spin states in charge transfer reactions (photo-induced electron transfer in photosynthesis). A general summary will also be presented of the biological effects of static magnetic fields studied in the laboratory and in natural settings. One aspect of magnetic field effects that merits special concern is their influence on implanted medical electronic devices such as cardiac pacemakers. Several extensive studies have demonstrated closure of the reed switch in pacemakers exposed to relatively weak static magnetic fields, thereby causing them to revert to an asynchronous mode of operation that is potentially hazardous. Recommendations for human exposure limits are provided

  3. Arsenic in the aquatic environment - speciation and biological effects

    Energy Technology Data Exchange (ETDEWEB)

    Landner, L [Swedish Environmental Research Group (MFG)

    1998-03-01

    The present report is a contribution to EC Commission`s undertaking to review existing EC provisions on the substances for which Sweden has been granted transitional provisions. The provisions imply that Sweden may maintain more stringent regulations on four substances until the end of 1998. The present report deals with speciation and biological effects of arsenic in three types of aquatic environments - marine water, estuarine or brackish water and freshwater. The similarity between arsenate and phosphate and the interference in phosphorylation reactions is discussed. It is clear that in Scandinavian inland waters the concentration of phosphorous is on average lower than in most inland waters in continental Europe. However, in most inland waters phosphorus is the limiting factor for phytoplankton development and eutrophication, which means that there is a clear risk for detrimental effects in the great majority of inland waters, also eutrophic waters 167 refs, 27 figs, 12 tabs. Exemption Substances Project (Directive 89/677/EEC)

  4. Relative biological effectiveness of protons and heavy particles

    International Nuclear Information System (INIS)

    Vyglenov, A.; Fedorenko, B.; Kabachenko, A.

    1986-01-01

    The genetic effectiveness was studied of protons (9 GeB/nuclon, 0,72 Gy/min), α-particles (4 GeB/nuclon, 0,9 Gy/min) and carbon ions (4 GeB/nuclon 0,36 Gy/min). The translocation yield in mouse spermatogonia was used as indicator of radiation-induced genetic injury. Reciprocal translocation were registered six months after the irradiation on spermatocytes in diakinesmetaphase I. Comparison was made with gamma-irradiated animals from 60 Co source with dose rate 1,44 Gy/min. The relative biological effectiveness (RBE) was determined by comparing the regression coefficients from the linear dose translocation yield dependency. The values of the RBE coefficients were 0.8, 0.9 and 1.2, accordingly for protons, α-particles and carbon ions

  5. Biological effects of static and low-frequency electromagnetic fields: an overview of United States literature

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, R.D.; Kaune, W.T.

    1977-04-12

    Results are reviewed from a number of studies on the biological effects of static and low frequency electromagnetic fields on animals. Based on a long history of experience with electric fields by the utility industry, it appears that intermittent and repeated exposures to strong 60-Hz electromagnetic fields from present power transmission systems have no obvious adverse effect on the health of man. It has been recognized recently that this belief must be tested by carefully designed and executed experiments under laboratory conditions where precise control can be exercised over coexisting environmental factors. A number of studies have been initiated in response to this need to evaluate possible effects from both acute and chronic exposures. 100 references.

  6. Enhanced Biological Phosphorus Removal : Metabolic Insights and Salinity Effects

    NARCIS (Netherlands)

    Welles, L.

    2015-01-01

    Enhanced biological phosphorus removal (EBPR) is a biological process for efficient phosphate removal from wastewaters through intracellular storage of polyphosphate by polyphosphate-accumulating organisms (PAO) and subsequent removal of PAO from the system through wastage of sludge. In comparison

  7. Simulated experiment for elimination of chemical and biological warfare agents by making use of microwave plasma torch

    International Nuclear Information System (INIS)

    Hong, Yong C.; Kim, Jeong H.; Uhm, Han S.

    2004-01-01

    The threat of chemical and biological warfare agents in a domestic terrorist attack and in military conflict is increasing worldwide. Elimination and decontamination of chemical and biological warfare (CBW) agents are immediately required after such an attack. Simulated experiment for elimination of CBW agents by making use of atmospheric-pressure microwave plasma torches is carried out. Elimination of biological warfare agents indicated by the vitrification or burnout of sewage sludge powders and decomposition of toluene gas as a chemical agent stimulant are presented. A detailed characterization for the elimination of the simulant chemicals using Fourier transform infrared and gas chromatography is also presented

  8. Simulated experiment for elimination of chemical and biological warfare agents by making use of microwave plasma torch

    Science.gov (United States)

    Hong, Yong C.; Kim, Jeong H.; Uhm, Han S.

    2004-02-01

    The threat of chemical and biological warfare agents in a domestic terrorist attack and in military conflict is increasing worldwide. Elimination and decontamination of chemical and biological warfare (CBW) agents are immediately required after such an attack. Simulated experiment for elimination of CBW agents by making use of atmospheric-pressure microwave plasma torches is carried out. Elimination of biological warfare agents indicated by the vitrification or burnout of sewage sludge powders and decomposition of toluene gas as a chemical agent stimulant are presented. A detailed characterization for the elimination of the simulant chemicals using Fourier transform infrared and gas chromatography is also presented.

  9. Experience Effect in E-Learning Research

    Science.gov (United States)

    Wu, Bing; Xu, WenXia; Ge, Jun

    This study is a productivity review on the literature gleaned from SSCI, SCIE databases concerning experience in E-Learning research. The result indicates that the number of literature productions on experience effect in ELearning research is still growing from 2005. The main research development country is Croatia, and from the analysis of the publication year, the number of papers is increasing to the peaking in 2010. And the main source title is British Journal of Educational Technology. In addition the subject area concentrated on Education & Educational Research. Moreover the research focuses on are mainly survey research and empirical research, in order to explore experience effect in E-Learning research. Also the limitations and future research of these research were discussed, so that the direction for further research work can be exploited

  10. Experience reverses the red effect among Chinese stockbrokers.

    Science.gov (United States)

    Zhang, Tengxiao; Han, Buxin

    2014-01-01

    Recent research has shown that the color red influences psychological functioning. Red is hypothesized to be linked to aggression and danger in evolution, and these links are enhanced by culture-specific uses of red. Thus, color meanings are thought to be grounded in biologically based proclivities and learned associations. However, to date, there has been no direct evidence for the influence of experience on the red effect. This study focused on whether experience could change the psychological effects of the color red. In the context of the Chinese stock market, contrary to the meaning generally associated with red as negative and green as positive, red represents a rise in stock price and green stands for a decrease. An experiment using a 2×2 between subjects factorial design demonstrated that red (compared with green) impaired Chinese college students' performance on an IQ test (in accordance with the red effect), but the opposite effect was found among stockbrokers. These results provide direct evidence of learned color meanings, in support of the general model of color effect.

  11. ASPIRE: An automated sample positioning and irradiation system for radiation biology experiments at Inter University Accelerator Centre, New Delhi

    International Nuclear Information System (INIS)

    Kothari, Ashok; Barua, P.; Archunan, M.; Rani, Kusum; Subramanian, E.T.; Pujari, Geetanjali; Kaur, Harminder; Satyanarayanan, V.V.V.; Sarma, Asitikantha; Avasthi, D.K.

    2015-01-01

    An automated irradiation setup for biology samples has been built at Inter University Accelerator Centre (IUAC), New Delhi, India. It can automatically load and unload 20 biology samples in a run of experiment. It takes about 20 min [2% of the cell doubling time] to irradiate all the 20 samples. Cell doubling time is the time taken by the cells (kept in the medium) to grow double in numbers. The cells in the samples keep growing during entire of the experiment. The fluence irradiated to the samples is measured with two silicon surface barrier detectors. Tests show that the uniformity of fluence and dose of heavy ions reaches to 2% at the sample area in diameter of 40 mm. The accuracy of mean fluence at the center of the target area is within 1%. The irradiation setup can be used to the studies of radiation therapy, radiation dosimetry and molecular biology at the heavy ion accelerator. - Highlights: • Automated positioning and irradiation setup for biology samples at IUAC is built. • Loading and unloading of 20 biology samples can be automatically carried out. • Biologicals cells keep growing during entire experiment. • Fluence and dose of heavy ions are measured by two silicon barrier detectors. • Uniformity of fluence and dose of heavy ions at sample position reaches to 2%

  12. Chemical and biological effects of radiation sterilization of medical products

    International Nuclear Information System (INIS)

    Gupta, B.L.

    1975-01-01

    Radiation is extensively used for the sterilization of plastic materials, pharmaceuticals and biological tissue grafts. The pharmaceuticals may be solid, liquid, or suspension in a liquid or a solution. Cobalt-60 gamma radiation, generally used for sterilization, primarily interacts with these materials through the Compton process. The resulting damage may be direct or indirect. In aqueous systems the primary species produced compete for interaction among themselves and the dissolved solutes. The nature, the G-values and the reactions of the primary species very much depend on the pH of the solution. The important chemical changes in plastic materials are gas liberation, change in concentration of double bonds, cross-linking, degradation and oxidation. These chemical changes lead to some physical changes like crystallinity, specific conductivity and permeability. The reactions in biological systems are very complex and are influenced by the presence or absence of water and oxygen. Water produces indirect damage and the radiation effect is generally more in the presence of oxygen. Most microorganisms are relatively radioresistant. Various tissues of an animal differ in their response to radiation. Catgut is not stable to irradiation. Lyophilized human serum is stable to irradiation whereas, when irradiated in aqueous solutions, several changes are observed. Generally, pharmaceuticals are considerably more stable in the dry solid state to ionizing radiations than in aqueous solutions or in any other form of molecular aggregation. (author)

  13. Biological vs. physical mixing effects on benthic food web dynamics.

    Directory of Open Access Journals (Sweden)

    Ulrike Braeckman

    Full Text Available Biological particle mixing (bioturbation and solute transfer (bio-irrigation contribute extensively to ecosystem functioning in sediments where physical mixing is low. Macrobenthos transports oxygen and organic matter deeper into the sediment, thereby likely providing favourable niches to lower trophic levels (i.e., smaller benthic animals such as meiofauna and bacteria and thus stimulating mineralisation. Whether this biological transport facilitates fresh organic matter assimilation by the metazoan lower part of the food web through niche establishment (i.e., ecosystem engineering or rather deprives them from food sources, is so far unclear. We investigated the effects of the ecosystem engineers Lanice conchilega (bio-irrigator and Abra alba (bioturbator compared to abiotic physical mixing events on survival and food uptake of nematodes after a simulated phytoplankton bloom. The (13C labelled diatom Skeletonema costatum was added to 4 treatments: (1 microcosms containing the bioturbator, (2 microcosms containing the bio-irrigator, (3 control microcosms and (4 microcosms with abiotic manual surface mixing. Nematode survival and subsurface peaks in nematode density profiles were most pronounced in the bio-irrigator treatment. However, nematode specific uptake (Δδ(13C of the added diatoms was highest in the physical mixing treatment, where macrobenthos was absent and the diatom (13C was homogenised. Overall, nematodes fed preferentially on bulk sedimentary organic material rather than the added diatoms. The total C budget (µg C m(-2, which included TO(13C remaining in the sediment, respiration, nematode and macrobenthic uptake, highlighted the limited assimilation by the metazoan benthos and the major role of bacterial respiration. In summary, bioturbation and especially bio-irrigation facilitated the lower trophic levels mainly over the long-term through niche establishment. Since the freshly added diatoms represented only a limited food

  14. Experiments to Demonstrate Piezoelectric and Pyroelectric Effects

    Science.gov (United States)

    Erhart, Jirí

    2013-01-01

    Piezoelectric and pyroelectric materials are used in many current applications. The purpose of this paper is to explain the basic properties of pyroelectric and piezoelectric effects and demonstrate them in simple experiments. Pyroelectricity is presented on lead zirconium titanate (PZT) ceramics as an electric charge generated by the temperature…

  15. Biological effects of particles from the paris subway system.

    Science.gov (United States)

    Bachoual, Rafik; Boczkowski, Jorge; Goven, Delphine; Amara, Nadia; Tabet, Lyes; On, Dinhill; Leçon-Malas, Véronique; Aubier, Michel; Lanone, Sophie

    2007-10-01

    Particulate matter (PM) from atmospheric pollution can easily deposit in the lungs and induce recruitment of inflammatory cells, a source of inflammatory cytokines, oxidants, and matrix metalloproteases (MMPs), which are important players in lung structural homeostasis. In many large cities, the subway system is a potent source of PM emission, but little is known about the biological effects of PM from this source. We performed a comprehensive study to evaluate the biological effects of PM sampled at two sites (RER and Metro) in the Paris subway system. Murine macrophages (RAW 264.7) and C57Bl/6 mice, respectively, were exposed to 0.01-10 microg/cm2 and 5-100 microg/mouse subway PM or reference materials [carbon black (CB), titanium dioxide (TiO2), or diesel exhaust particles (DEPs)]. We analyzed cell viability, production of cellular and lung proinflammatory cytokines [tumor necrosis factor alpha (TNFalpha), macrophage inflammatory protein (MIP-2), KC (the murin analog of interleukin-8), and granulocyte macrophage-colony stimulating factor (GM-CSF)], and mRNA or protein expression of MMP-2, -9, and -12 and heme oxygenase-1 (HO-1). Deferoxamine and polymixin B were used to evaluate the roles of iron and endotoxin, respectively. Noncytotoxic concentrations of subway PM (but not CB, TiO2, or DEPs) induced a time- and dose-dependent increase in TNFalpha and MIP-2 production by RAW 264.7 cells, in a manner involving, at least in part, PM iron content (34% inhibition of TNF production 8 h after stimulation of RAW 264.7 cells with 10 microg/cm2 RER particles pretreated with deferoxamine). Similar increased cytokine production was transiently observed in vivo in mice and was accompanied by an increased neutrophil cellularity of bronchoalveolar lavage (84.83+/-0.98% of polymorphonuclear neutrophils for RER-treated mice after 24 h vs 7.33+/-0.99% for vehicle-treated animals). Subway PM induced an increased expression of MMP-12 and HO-1 both in vitro and in vivo. PM from the

  16. A Conceptual Framework for Organizing Active Learning Experiences in Biology Instruction

    Science.gov (United States)

    Gardner, Joel; Belland, Brian R.

    2012-01-01

    Introductory biology courses form a cornerstone of undergraduate instruction. However, the predominantly used lecture approach fails to produce higher-order biology learning. Research shows that active learning strategies can increase student learning, yet few biology instructors use all identified active learning strategies. In this paper, we…

  17. The relative biological effectiveness of radiations of different quality

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This paper is a review of the literature relevant to the selection of relative biological effectiveness (RBE) values for use in arriving at values of the quality factor (Q). Emphasis is placed on response to small ( M . In a wide variety of systems, the RBE M for fast (fission) neutrons, with low doses and dose rates, appears to be of the order of 20 or more compared to moderately filtered 250 kVp x rays and 40 or more compared to higher energy gamma rays. These values, which are much larger than those observed with large doses delivered at high dose rates, are due mainly, but not entirely, to a decrease in the slope of the curve for the ow-LET reference radiation at low dose

  18. Interaction mechanisms and biological effects of static magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Tenforde, T.S.

    1994-06-01

    Mechanisms through which static magnetic fields interact with living systems are described and illustrated by selected experimental observations. These mechanisms include electrodynamic interactions with moving, ionic charges (blood flow and nerve impulse conduction), magnetomechanical interactions (orientation and translation of molecules structures and magnetic particles), and interactions with electronic spin states in charge transfer reactions (photo-induced electron transfer in photosynthesis). A general summary is also presented of the biological effects of static magnetic fields. There is convincing experimental evidence for magnetoreception mechanisms in several classes of lower organisms, including bacteria and marine organisms. However, in more highly evolved species of animals, there is no evidence that the interactions of static magnetic fields with flux densities up to 2 Tesla (1 Tesla [T] = 10{sup 4} Gauss) produce either behavioral or physiolocical alterations. These results, based on controlled studies with laboratory animals, are consistent with the outcome of recent epidemiological surveys on human populations exposed occupationally to static magnetic fields.

  19. Research program on the biological effects of oil pollution

    International Nuclear Information System (INIS)

    Barrett, R.T.

    1991-12-01

    A national research program on the biological effects of oil pollution (FOBO) was initiated by the Norwegian Ministry of Environment in October 1983 in the light of the increasing oil exploration and production activity in the North Sea and northern Norwegian waters. Ambitions were high and five main fields of research were suggested: Seabirds, fish (incl. salmon), marine mammals, the littoral zone and plankton. However, due to the lack of interest on the part of other potential financers, e.g. the Ministry of Fisheries and the oil companies, to participate, the four-year programme had to be limited to the following three topics: Seabirds around bruding colonies and at sea; Higher plants along the shoreline; The littoral zone. The program ran from the autumn of 1985 to the end of 1989 and this report summarizes the main results and conclusions of each project. 95 refs., 52 figs., 9 tabs

  20. Effects of biological sex on the pathophysiology of the heart.

    Science.gov (United States)

    Fazal, Loubina; Azibani, Feriel; Vodovar, Nicolas; Cohen Solal, Alain; Delcayre, Claude; Samuel, Jane-Lise

    2014-02-01

    Cardiovascular diseases are the leading causes of death in men and women in industrialized countries. While the effects of biological sex on cardiovascular pathophysiology have long been known, the sex-specific mechanisms mediating these processes have been further elucidated over recent years. This review aims at analysing the sex-based differences in cardiac structure and function in adult mammals, and the sex-based differences in the main molecular mechanisms involved in the response of the heart to pathological situations. It emerged from this review that the sex-based difference is a variable that should be dealt with, not only in basic science or clinical research, but also with regards to therapeutic approaches. © 2013 The British Pharmacological Society.

  1. Challenges in Analyzing the Biological Effects of Resveratrol

    DEFF Research Database (Denmark)

    Erdogan, Cihan Süleyman; Vang, Ole

    2016-01-01

    The suggested health effects (e.g., disease prevention) of dietary bioactive compounds such as resveratrol are challenging to prove in comparison to man-made drugs developed for therapeutic purposes. Dietary bioactive compounds have multiple cellular targets and therefore have a variety of biolog......The suggested health effects (e.g., disease prevention) of dietary bioactive compounds such as resveratrol are challenging to prove in comparison to man-made drugs developed for therapeutic purposes. Dietary bioactive compounds have multiple cellular targets and therefore have a variety...... research. Questions we address include: (1) Is the combinatorial effect of resveratrol and other compounds real? (2) What are the real and relevant doses of resveratrol after administration? and (3) Is it possible to estimate the preventive effect of resveratrol by clinical trials using standard...... experimental designs? The examples concerning resveratrol taken from the scientific literature are mainly from 2010 and later. The challenges pointed out in this review are similar to most naturally occurring bioactive compounds...

  2. Biological effects of carvacrol and cinnamaldehyde on Acinetobacter baumannii

    Directory of Open Access Journals (Sweden)

    Angélique Montagu

    2016-07-01

    Full Text Available Acinetobacter baumannii has emerged as a major cause of nosocomial infections. The ability of A. baumannii to display various resistance mechanisms against antibiotics has transformed it into a successful nosocomial pathogen. The limited number of antibiotics in development and the disengagement of the pharmaceutical industry have prompted the development of innovative strategies. One of these strategies is the use of essential oils, especially aromatic compounds that are potent antibacterial molecules. Among them, the combination of carvacrol and cinnamaldehyde has already demonstrated antibacterial efficacy against A. baumannii. The aim of this study was to determine the biological effects of these two compounds in A. baumannii, describing their effect on the rRNA and gene regulation under environmental stress conditions. Results demonstrated rRNA degradation by the carvacrol/cinnamaldehyde mixture, and this effect was due to carvacrol. Degradation was conserved after encapsulation of the mixture in lipid nanocapsules. Results showed an upregulation of the genes coding for heat shock proteins, such as groES, groEL, dnaK, clpB and the catalase katE, after exposure to carvacrol/cinnamaldehyde mixture. The catalase was upregulated after carvacrol exposure wich is related to an oxidative stress. The combination of thiourea (hydroxyl radical scavenger and carvacrol demonstrated a potent bactericidal effect. These results underline the development of defense strategies of the bacteria by synthesis of reactive oxygen species (ROS in response to environmental stress conditions, such as carvacrol.

  3. Biological Effects of Electromagnetic Radiation. Volume II, Number 4.

    Science.gov (United States)

    1975-12-01

    limb . Magnetotherapy proved superior to all of gain; total serum protein; Na+, and K~ ; and rectal the methods tested so far. These include electro...indicate that magnetotherapy has an crease. None of these changes exceeded normal limits, inhibitory effect on the CNS , a spasmolytic action on peripheral...are attributed to differences in the state of ascites fluid proteins during tumor develop— 0685 EXPERIENCE WITH MAGNETOTHERAPY FOR PAINFUL ment

  4. Are biological effects of desert shrubs more important than physical effects on soil microorganisms?

    Science.gov (United States)

    Berg, Naama; Steinberger, Yosef

    2010-01-01

    Vegetation cover plays a major role in providing organic matter and in acting as a physical barrier, with both together contributing to the formation of "fertile islands," which play an active role in prolonging biological activity in desert ecosystems. By undertaking this study, a longterm research, we designed an experiment to separate the two components-the physical and biotic parts of the perennial plants-and to identify the factor that contributes the most to the ecosystem. The study site was located in the northern Negev Desert, Israel, where 50 Hammada scoparia shrubs and 50 artificial plants were randomly marked. Soil samples were collected monthly over 3 years of research at three locations: under the canopy of H. scoparia shrubs, in the vicinity of the artificial plants, and between the shrubs (control). The contribution to microbial activity was measured by evaluation of the microbial community functions in soil. The functional aspects of the microbial community that were measured were CO2 evolution, microbial biomass, microbial functional diversity, and the physiological profile of the community. The results of this study are presented in two ways: (1) according to the three locations/treatments; and (2) according to the phenological situation of the vegetation (annual and perennial plants) in the research field: the growing phase, the drying process, and the absence of annual plants. The only parameters that were found to affect microbial activity were the contribution of the organic matter of perennial shrubs and the growth of vegetation (annual and perennial) during the growing seasons. The physical component was found to have no effect on soil microbial functional diversity, which elucidates the important contribution of the desert shrub in enhancing biological multiplicity and activity.

  5. Molecular gyroscopes and biological effects of weak extremely low-frequency magnetic fields

    International Nuclear Information System (INIS)

    Binhi, V.N.; Savin, A.V.

    2002-01-01

    Extremely low-frequency magnetic fields are known to affect biological systems. In many cases, biological effects display 'windows' in biologically effective parameters of the magnetic fields: most dramatic is the fact that the relatively intense magnetic fields sometimes do not cause appreciable effect, while smaller fields of the order of 10-100 μT do. Linear resonant physical processes do not explain the frequency windows in this case. Amplitude window phenomena suggest a nonlinear physical mechanism. Such a nonlinear mechanism has been proposed recently to explain those 'windows'. It considers the quantum-interference effects on the protein-bound substrate ions. Magnetic fields cause an interference of ion quantum states and change the probability of ion-protein dissociation. This ion-interference mechanism predicts specific magnetic-field frequency and amplitude windows within which the biological effects occur. It agrees with a lot of experiments. However, according to the mechanism, the lifetime Γ -1 of ion quantum states within a protein cavity should be of unrealistic value, more than 0.01 s for frequency band 10-100 Hz. In this paper, a biophysical mechanism has been proposed, which (i) retains the attractive features of the ion interference mechanism, i.e., predicts physical characteristics that might be experimentally examined and (ii) uses the principles of gyroscopic motion and removes the necessity to postulate large lifetimes. The mechanism considers the dynamics of the density matrix of the molecular groups, which are attached to the walls of protein cavities by two covalent bonds, i.e., molecular gyroscopes. Numerical computations have shown almost free rotations of the molecular gyroscopes. The relaxation time due to van der Waals forces was about 0.01 s for the cavity size of 28 Aa

  6. Biological mechanisms of radiation effects; Biologische Mechanismen der Strahlenwirkung

    Energy Technology Data Exchange (ETDEWEB)

    Gruber, S.; Doerr, W. [Medizinische Universitaet Wien, ATRAB - Angewandte und Translationale Radiobiologie, Univ.-Klinik fuer Strahlentherapie, Wien (Austria)

    2017-07-15

    Exposure to ionizing radiation for diagnostic purposes is inevitable in modern medicine. The therapeutic application of irradiation is highly effective against cancer; however, this implies exposure of normal tissue structures to significant doses of radiation. Diagnostic or therapeutic exposure to ionizing radiation can result in tissue changes and tumor induction in the long term. Knowledge of the biological mechanisms underlying these effects is essential for individualization of the application. This article examines the biological mechanisms at the tissue and molecular level, the clinical manifestation of radiation effects, dose-dependence of the risk and the temporal progression as well as influencing factors. The time course of the reaction of tissues to radiation exposure extends over wide ranges up to many decades. The effects of radiation on tissues are classified into early and late and their pathobiology is significantly different. Various factors (R) influencing the clinical manifestation of radiation effects have been identified related to the exposure pattern. The radiation tolerance of normal tissue structures regarding the induction of functional deficits shows great variation but always has a threshold value, which is usually not exceeded in diagnostic procedures. The risk of a radiation-induced fatal malignancy (total body exposure 5%/Gy) for a medical administration of radiation must be considered as very low in comparison to the natural risks. Informed consent of patients must reflect this in a balanced way. (orig.) [German] Eine Exposition mit ionisierender Strahlung fuer diagnostische Zwecke ist in der modernen Medizin unumgaenglich. Bei einer Tumorerkrankung ist die therapeutische Anwendung dieser Strahlung hoch effektiv. Dies impliziert immer eine Exposition normaler Gewebestrukturen mit signifikanten Strahlendosen. Die diagnostische oder therapeutische Exposition mit ionisierender Strahlung kann langfristig zu Gewebeveraenderungen und

  7. Radiation degradation of alginate and some results of biological effect of degraded alginate on plants

    International Nuclear Information System (INIS)

    Hien, N.Q.; Hai, L.; Luan, L.Q.; Hanh, T.T.; Nagasawa, Naotsugu; Yoshii, Fumio; Makuuchi, Keizo; Kume, Tamikazu

    2000-01-01

    Radiation degradation yields (Gd) of alginate in aqueous solution with different concentration were determined by viscometry method. The relationship between Gd and the alginate concentration was found out as: Gd=33.5 x C -0.68 , with C% (w/v) and dry alginate referred to C=100%. An empirical equation for preparing degraded alginate with the desired low viscometry average molecular weight (Mv) by radiation was proposed. Alginate extracted directly horn seaweed'Sagassum, degraded by radiation was used for field experiments and results of the biological effect on plants (tea, carrot, chrysanthemum) were presented. (author)

  8. Studies with encapsulated 125I sources: dosimetry for determination of relative biological effectiveness

    International Nuclear Information System (INIS)

    Goldhagen, P.; Freeman, M.L.; Hall, E.J.

    1981-01-01

    During the past year, members of this laboratory have measured the Relative Biological Effectiveness (RBE) of photons from encapsulated 125 I sources (mean energy = 28.33 keV) using 661.6 keV 137 Cs gamma rays as a standard for comparison. These experiments were performed at clinically relevant dose rates and used reduction of the reproductive viability of mammalian cells as an endpoint. This section will discuss how dosimetry problems special to 125 I influence the design of the apparatus and will describe the ionization chamber to be used for measuring dose rates from both 125 I and 137 Cs photons

  9. Radiation degradation of alginate and some results of biological effect of degraded alginate on plants

    Energy Technology Data Exchange (ETDEWEB)

    Hien, N.Q.; Hai, L.; Luan, L.Q.; Hanh, T.T. [Nuclear Research Institute, Dalat (Viet Nam); Nagasawa, Naotsugu; Yoshii, Fumio; Makuuchi, Keizo; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    Radiation degradation yields (Gd) of alginate in aqueous solution with different concentration were determined by viscometry method. The relationship between Gd and the alginate concentration was found out as: Gd=33.5 x C{sup -0.68}, with C% (w/v) and dry alginate referred to C=100%. An empirical equation for preparing degraded alginate with the desired low viscometry average molecular weight (Mv) by radiation was proposed. Alginate extracted directly horn seaweed'Sagassum, degraded by radiation was used for field experiments and results of the biological effect on plants (tea, carrot, chrysanthemum) were presented. (author)

  10. Biological effects of nuclear war. I. Impact on humans

    International Nuclear Information System (INIS)

    Harwell, M.A.; Grover, H.D.

    1985-01-01

    The studies of the effects of nuclear war over the last four decades have concentrated almost exclusively on immediate consequences like these, primarily because these were by far the dominant effects on humans and the environment in Hiroshima and Nagasaki. Long-term and indirect effects have not been obvious. Detailed studies of the individual detonations over Japan and of nuclear tests since then have characterized well the immediate direct effects of blast, ionizing radiation, and thermal radiation. Such studies form the bases decision makers rely on to develop nuclear policies for the major powers. But the consequences of a large-scale nuclear war cannot be so readily extrapolated from the limited experiences in Japan. In this paper the authors review how the indirect and longer-term consequences for humans and the environment are now becoming better understood. This information fundamentally changes the way a modern nuclear war should be perceived

  11. Determining environmental causes of biological effects: the need for a mechanistic physiological dimension in conservation biology.

    Science.gov (United States)

    Seebacher, Frank; Franklin, Craig E

    2012-06-19

    The emerging field of Conservation Physiology links environmental change and ecological success by the application of physiological theory, approaches and tools to elucidate and address conservation problems. Human activity has changed the natural environment to a point where the viability of many ecosystems is now under threat. There are already many descriptions of how changes in biological patterns are correlated with environmental changes. The next important step is to determine the causative relationship between environmental variability and biological systems. Physiology provides the mechanistic link between environmental change and ecological patterns. Physiological research, therefore, should be integrated into conservation to predict the biological consequences of human activity, and to identify those species or populations that are most vulnerable.

  12. The biological effects of exposure to ionising radiation

    International Nuclear Information System (INIS)

    Higson, D.J.

    2016-01-01

    Scenarios for exposure to ionising radiation range from natural background radiation (chronic) to the explosions of atomic bombs (acute), with some medical, industrial and research exposures lying between these extremes. Biological responses to radiation that predominate at high doses incurred at high dose rates are different from those that predominate at low doses and low dose rates. Single doses from bomb explosions ranged up to many thousand mGy. Acute doses greater than about 1000 mGy cause acute radiation syndrome (ARS). Below this threshold, radiation has a variety of potential latent health effects: Change to the incidence of cancer is the most usual subject of attention but change to longevity may be the best overall measure because decreased incidences of non-cancer mortality have been observed to coincide with increased incidence of cancer mortality. Acute doses greater than 500 mGy cause increased risks of cancer and decreased life expectancy. For doses less than 100 mGy, beneficial overall health effects ('radiation hormesis') have been observed. At the other end of the spectrum, chronic exposure to natural radiation has occurred throughout evolution and is necessary for the normal life and health of current species. Dose rates greater than the present global average of about 2 mGy per year have either no discernible health effect or beneficial health effects up to several hundred mGy per year. It is clearly not credible that a single health effects model -- such as the linear no-threshold (LNT) model of risk estimation -- could fit all latent health effects. A more realistic model is suggested.

  13. The relative biological effectiveness of I-125 and Pd-103

    International Nuclear Information System (INIS)

    Ling, C. Clifton; Li, William X.; Anderson, Lowell L.

    1995-01-01

    Purpose: To determine the relative biological effectiveness (RBE) of I-125 and Pd-103 relative to Co-60. Methods and Materials: A cell line REC:ras, derived from rat embryo cells, was used. Cells in exponential or plateau phase were irradiated at dose rates of about 0.07 Gy/h and 0.14 Gy/h. To circumvent the interface effect, cells were grown and irradiated on membranes made of cellulose acetate, which has an effective Z of 7.5. I-125 and Pd-103 seeds were placed in a custom designed template that yielded a homogeneous dose distribution in the plane of the cell culture. The dose rates of irradiation were measured by calibrated thermoluminescence dosimetry (TLD) chips. Results and Conclusions: Our measurements yielded an RBE of about 1.4 for I-125 at dose rates of about 0.07 Gy/h, and an RBE of about 1.9 for Pd-103 at dose rates of about 0.07 Gy/h and 0.14 Gy/h. The RBE of I-125 is similar to those measured by other investigators, the RBE for Pd-103 is being reported for the first time

  14. Hydrodynamic effects in laser cutting of biological tissue phantoms

    Science.gov (United States)

    Zhigarkov, V. S.; Yusupov, V. I.; Tsypina, S. I.; Bagratashvili, V. N.

    2017-11-01

    We study the thermal and transport processes that occur in the course of incision formation at the surface of a biological tissue phantom under the action of near-IR, moderate-power, continuous-wave laser radiation (λ = 1.94 μm) delivered by means of an optical fibre with an absorbing coating on its exit face. It is shown that in addition to the thermal effect, the laser-induced hydrodynamic effects caused by the explosive boiling of the interstitial water make a large contribution to the phantom destruction mechanism. These effects lead to the tissue rupture accompanied by the ejection of part of the fragmented substance from the site of laser impact and the formation of highly porous structure near the incision surface. We have found that the depth, the width and the relief of the laser incision wall in the case of using the optical fibre moving with a constant velocity, depend on the fibre tilt angle with respect to the phantom surface, as well as the direction of the fibre motion.

  15. A comprehensive experiment for molecular biology: Determination of single nucleotide polymorphism in human REV3 gene using PCR-RFLP.

    Science.gov (United States)

    Zhang, Xu; Shao, Meng; Gao, Lu; Zhao, Yuanyuan; Sun, Zixuan; Zhou, Liping; Yan, Yongmin; Shao, Qixiang; Xu, Wenrong; Qian, Hui

    2017-07-08

    Laboratory exercise is helpful for medical students to understand the basic principles of molecular biology and to learn about the practical applications of molecular biology. We have designed a lab course on molecular biology about the determination of single nucleotide polymorphism (SNP) in human REV3 gene, the product of which is a subunit of DNA polymerase ζ and SNPs in this gene are associated with altered susceptibility to cancer. This newly designed experiment is composed of three parts, including genomic DNA extraction, gene amplification by PCR, and genotyping by RFLP. By combining these activities, the students are not only able to learn a series of biotechniques in molecular biology, but also acquire the ability to link the learned knowledge with practical applications. This comprehensive experiment will help the medical students improve the conceptual understanding of SNP and the technical understanding of SNP detection. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(4):299-304, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

  16. Formamidopyrimidines in DNA: mechanisms of formation, repair, and biological effects.

    Science.gov (United States)

    Dizdaroglu, Miral; Kirkali, Güldal; Jaruga, Pawel

    2008-12-15

    Oxidatively induced damage to DNA results in a plethora of lesions comprising modified bases and sugars, DNA-protein cross-links, tandem lesions, strand breaks, and clustered lesions. Formamidopyrimidines, 4,6-diamino-5-formamidopyrimidine (FapyAde) and 2,6-diamino-4-hydroxy-5-formamidopyrimidine (FapyGua), are among the major lesions generated in DNA by hydroxyl radical attack, UV radiation, or photosensitization under numerous in vitro and in vivo conditions. They are formed by one-electron reduction of C8-OH-adduct radicals of purines and thus have a common precursor with 8-hydroxypurines generated upon one-electron oxidation. Methodologies using mass spectrometry exist to accurately measure FapyAde and FapyGua in vitro and in vivo. Formamidopyrimidines are repaired by base excision repair. Numerous prokaryotic and eukaryotic DNA glycosylases are highly specific for removal of these lesions from DNA in the first step of this repair pathway, indicating their biological importance. FapyAde and FapyGua are bypassed by DNA polymerases with the insertion of the wrong intact base opposite them, leading to mutagenesis. In mammalian cells, the mutagenicity of FapyGua exceeds that of 8-hydroxyguanine, which is thought to be the most mutagenic of the oxidatively induced lesions in DNA. The background and formation levels of the former in vitro and in vivo equal or exceed those of the latter under various conditions. FapyAde and FapyGua exist in living cells at significant background levels and are abundantly generated upon exposure to oxidative stress. Mice lacking the genes that encode specific DNA glycosylases accumulate these lesions in different organs and, in some cases, exhibit a series of pathological conditions including metabolic syndrome and cancer. Animals exposed to environmental toxins accumulate formamidopyrimidines in their organs. Here, we extensively review the mechanisms of formation, measurement, repair, and biological effects of formamidopyrimidines

  17. Enhanced Biological Phosphorus Removal: Metabolic Insights and Salinity Effects

    OpenAIRE

    Welles, L.

    2015-01-01

    Enhanced biological phosphorus removal (EBPR) is a biological process for efficient phosphate removal from wastewaters through intracellular storage of polyphosphate by polyphosphate-accumulating organisms (PAO) and subsequent removal of PAO from the system through wastage of sludge. In comparison to physical and chemical phosphorus removal processes, the biological process has several advantages such as high removal efficiency, low cost, and no chemical sludge production, but disturbances an...

  18. Relative biological efficiency of 592 MeV protons. Analysis of the biological effect of secondary radiation

    International Nuclear Information System (INIS)

    Legeay, G.; Baarli, J.

    1968-01-01

    The relative biological efficiency (RBE) of high energy protons is of importance because of their effects in the field of radioprotection around large accelerators and during space-flights. The nature of the interactions between 592 MeV protons and biological tissues makes it necessary to take into consideration the contribution of secondary radiation to the biological effect. Since it is not possible to obtain from a synchrotron a beam having a sufficiently large cross-section to irradiate large animals, one has to resort to certain devices concerning the mode of exposure when small laboratory animals are used. By irradiating rats individually and in groups, and by using the lethal test as a function of time, the authors show that the value of the RBE is different for animals of the same species having the same biological parameters. Thus there appears an increase in the biological effect due to secondary radiation produced in nuclear cascades which develop in a large volume, for example that of a human being. (author) [fr

  19. Relative biological effectiveness if alpha radiation for human lung exposure

    International Nuclear Information System (INIS)

    Yarmoshenko, I.; Kirdin, I.; Zhukovsky, M.

    2006-01-01

    Full text of publication follows: The concept of RBE, which introduced by ICRP and ICRU about 50 years ago to compare biological effects of ionizing radiation of different types, still continues to be the essential element of current and projected radiation protection systems in terms of deriving quantities (quality factor and radiation weighting factor). For example, RBE for the stochastic effects induction has to be considered for appropriate radiation weighting of the absorbed dose while estimating equivalent dose. Simulation of lung cancer radiation risk for the cases of inhalation of radon progeny and incorporation of plutonium in lung in comparison with external reference radiation allows assessment of RBE for alpha-radiation. Specific radiation risk models were developed by results of the direct epidemiological studies and used for such simulation. Simulation included published risk models for nuclear workers of the Mayak facilities in the former Soviet Union exposed to incorporated plutonium (Kreisheimer et al., 2003; Gilbert et al., 2004) and underground miners exposed to radon progenies (BEIR VI, 1999). Additionally lung cancer risk model was developed for a case of population indoor radon exposure. Lung cancer risk related to external exposure is estimated using the risk model develop ed using data of Life Span Study of Japanese atomic bomb survivors. By results of lifetime lung cancer risk simulation using Monte Carlo approach estimated median value of RBE in case of indoor radon exposure is 1.5 (with 90% range 0.4 to 7). In case of the two models developed by BEIR VI for lung cancer risk due to radon exposure in underground miners the median values of RBE are 2.1 and 4.4 (with 90% ranges 0.3 to 17 and 0.7 to 45) respectively.Two different models for lung cancer risk related to plutonium exposure resulted in close estimates of RBE: median value of 12 and 13 (with 90% range 4 to 104 and 4 to 136) respectively. Considerable discrepancy between RBE

  20. More Ideas for Monitoring Biological Experiments with the BBC Computer: Absorption Spectra, Yeast Growth, Enzyme Reactions and Animal Behaviour.

    Science.gov (United States)

    Openshaw, Peter

    1988-01-01

    Presented are five ideas for A-level biology experiments using a laboratory computer interface. Topics investigated include photosynthesis, yeast growth, animal movements, pulse rates, and oxygen consumption and production by organisms. Includes instructions specific to the BBC computer system. (CW)

  1. Scientific projection paper on biologic effects of ionizing radiation

    International Nuclear Information System (INIS)

    Matanoski, G.

    1980-01-01

    There is widespread knowledge about the effects of radiation in human populations but the studies have had some limitations which have left gaps in our knowledge. Most populations have had exposure to high doses with little information on the effect of dose rate. The characteristics of the populations have been restricted by the location of the disaster, the occupational limitations, or the basic risks associated with the under-lying disease for which radiation was given. All doses have been estimated and such values are subject to marked variability particularly when they rely on sources of data such as hospital records. The biological data although extensive have several deficits in information. Which are the sites in which cancer is produced by irradiation and what are the cell types which are produced. The sensitivity of various tissues and organs are not similar and it is important to rank them according to susceptibility. This has been done in the past but the results are not complete for all cell types and organs. The temporal patterns for tumor development, the latent period, the period of expressed excess, the life-time risks need to be defined more precisely for the cancers. Many populations have not been followed long enough to express the complete risk

  2. Biological and sanitary effects of non ionizing radiations

    International Nuclear Information System (INIS)

    Brugere, H.; Hours, M.; Seze, R. de; Bernier, M.; Letertre, Th.; Aurengo, A.; Burais, N.; Bedja, M.; Merckel, O.; Decat, G.; Lagroye, I.; Perrin, A.; Poulletier de Gannes, F.; Aurengo, A.; Souques, M.; Cesarini, J.P.; Lagroye, I.; Aurengo, A.; Cesarini, J.P.

    2008-01-01

    The objective of this day was to encourage the collaborations, especially multidisciplinary, on the biological, clinical, epidemiological and dosimetry aspects. The different presentations are as follow: the magneto reception among animals; the health and radio frequencies foundation; expo-metry to radio frequency fields: dosemeters evaluation; the electro-optical probes as tool of hyper frequency dosimetry; characterisation of emissions produced by the low consumption fluo-compact lamps in the perspective of persons exposure; strong and weak points of epidemiology; numerical dosimetry in low frequency magnetic and/or electric field; exposure of the French population to the 50 Hz magnetic field: first results for the Ile-de-france and Rhone alpes areas; characterisation of the exposure to the very low frequency magnetic fields in the town of Champlan; measurement of the residential exposure of children to the extremely low frequency, very low frequency and radiofrequency (E.L.F., V.L.F. and R.F.) fields and modeling of the high voltage magnetic field face to the child leukemia; effects of radiofrequency signals of wireless communications on the young animals; study of combined effects of 2.45 GHz microwaves and a known mutagen on DNA by two different approaches; effects on the oxidizing stress of nervous cells exposure to an (enhanced data rates for GSM evolution) E.D.G.E. signal; is environmental epidemiology still a science; cardiac implants and exposure to 50 Hz electromagnetic fields in occupational environment; the tanning by artificial UV radiation: norms and legislation; mobiles phones, Wi Fi and other wireless communications; effects on health of 50-60 Hz electromagnetic fields; natural and artificial ultraviolet radiations: a proved risk. (N.C.)

  3. Biological effects of radiation and health risks from exposure to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Kotian, Rahul P.; Kotian, Sahana Rahul; Sukumar, Suresh

    2013-01-01

    The very fact that ionizing radiation produces biological effects is known from many years. The first case of injury reported by Sir Roentgen was reported just after a few months after discovery of X-rays in 1895. As early as 1902, the first case of X-ray induced cancer was reported in the literature. Early human evidence of harmful effects as a result of exposure to radiation in large amounts existed in the 1920s and 1930s, based upon the experience of early radiologists, miners exposed to airborne radioactivity underground, persons working in the radium industry, and other special occupational groups. The long-term biological significance of smaller, repeated doses of radiation, however, was not widely appreciated until relatively recently, and most of our knowledge of the biological effects of radiation has been accumulated since World War II. The mechanisms that lead to adverse health effects after exposure to ionizing radiation are still not fully understood. Ionizing radiation has sufficient energy to change the structure of molecules, including DNA, within the cells of the body. Some of these molecular changes are so complex that it may be difficult for the body's repair mechanisms to mend them correctly. However, the evidence is that only a small fraction of such changes would be expected to result in cancer or other health effects. The most thoroughly studied individuals for the evaluation of health effects of ionizing radiation are the survivors of the Hiroshima and Nagasaki atomic bombings, a large population that includes all ages and both sexes.The Radiation Effects Research Foundation (RERF) in Japan has conducted followup studies on these survivors for more than 50 years. An important finding from these studies is that the occurrence of solid cancers increases in proportion to radiation dose. More than 60% of exposed survivors received a dose of radiation of less than 100 mSv (the definition of low dose used by the BEIR VII report). (author)

  4. Biological effects of radiation human health and safety

    International Nuclear Information System (INIS)

    1977-05-01

    The biological hazards of nuclear energy usage are a growing source of public concern. The medical profession may well be expected to contribute to public debate on the issue. This document, therefore, attempts a balanced review of the known and suspected human biological consequences of exposure to different types of ionizing radiation, emphasizing in particular the nuclear industry

  5. The biological effects of ionising radiation on Crustaceans: A review

    International Nuclear Information System (INIS)

    Fuller, Neil; Lerebours, Adélaïde; Smith, Jim T.; Ford, Alex T.

    2015-01-01

    Highlights: • We comprehensively review the effects of ionising radiation in crustaceans. • Current environmental radioprotection levels found to be inadequate in some cases. • Mutation is shown to be a sensitive endpoint of radiation exposure. • Lowest observed effect dose rate varies by orders of magnitude. - Abstract: Historic approaches to radiation protection are founded on the conjecture that measures to safeguard humans are adequate to protect non-human organisms. This view is disparate with other toxicants wherein well-developed frameworks exist to minimise exposure of biota. Significant data gaps for many organisms, coupled with high profile nuclear incidents such as Chernobyl and Fukushima, have prompted the re-evaluation of our approach toward environmental radioprotection. Elucidating the impacts of radiation on biota has been identified as priority area for future research within both scientific and regulatory communities. The crustaceans are ubiquitous in aquatic ecosystems, comprising greater than 66,000 species of ecological and commercial importance. This paper aims to assess the available literature of radiation-induced effects within this subphylum and identify knowledge gaps. A literature search was conducted pertaining to radiation effects on four endpoints as stipulated by a number of regulatory bodies: mortality, morbidity, reproduction and mutation. A major finding of this review was the paucity of data regarding the effects of environmentally relevant radiation doses on crustacean biology. Extremely few studies utilising chronic exposure durations or wild populations were found across all four endpoints. The dose levels at which effects occur was found to vary by orders of magnitude thus presenting difficulties in developing phyla-specific benchmark values and reference levels for radioprotection. Based on the limited data, mutation was found to be the most sensitive endpoint of radiation exposure, with mortality the least sensitive

  6. The biological effects of ionising radiation on Crustaceans: A review

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Neil; Lerebours, Adélaïde [Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Ferry Road, Portsmouth, Hampshire PO4 9LY (United Kingdom); Smith, Jim T. [School of Earth & Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth, Hampshire PO1 3QL (United Kingdom); Ford, Alex T., E-mail: alex.ford@port.ac.uk [Institute of Marine Sciences, School of Biological Sciences, University of Portsmouth, Ferry Road, Portsmouth, Hampshire PO4 9LY (United Kingdom)

    2015-10-15

    Highlights: • We comprehensively review the effects of ionising radiation in crustaceans. • Current environmental radioprotection levels found to be inadequate in some cases. • Mutation is shown to be a sensitive endpoint of radiation exposure. • Lowest observed effect dose rate varies by orders of magnitude. - Abstract: Historic approaches to radiation protection are founded on the conjecture that measures to safeguard humans are adequate to protect non-human organisms. This view is disparate with other toxicants wherein well-developed frameworks exist to minimise exposure of biota. Significant data gaps for many organisms, coupled with high profile nuclear incidents such as Chernobyl and Fukushima, have prompted the re-evaluation of our approach toward environmental radioprotection. Elucidating the impacts of radiation on biota has been identified as priority area for future research within both scientific and regulatory communities. The crustaceans are ubiquitous in aquatic ecosystems, comprising greater than 66,000 species of ecological and commercial importance. This paper aims to assess the available literature of radiation-induced effects within this subphylum and identify knowledge gaps. A literature search was conducted pertaining to radiation effects on four endpoints as stipulated by a number of regulatory bodies: mortality, morbidity, reproduction and mutation. A major finding of this review was the paucity of data regarding the effects of environmentally relevant radiation doses on crustacean biology. Extremely few studies utilising chronic exposure durations or wild populations were found across all four endpoints. The dose levels at which effects occur was found to vary by orders of magnitude thus presenting difficulties in developing phyla-specific benchmark values and reference levels for radioprotection. Based on the limited data, mutation was found to be the most sensitive endpoint of radiation exposure, with mortality the least sensitive

  7. Effect of Process-Oriented Guided-Inquiry Learning on Non-majors Biology Students' Understanding of Biological Classification

    Science.gov (United States)

    Wozniak, Breann M.

    The purpose of this study was to examine the effect of process-oriented guided-inquiry learning (POGIL) on non-majors college biology students' understanding of biological classification. This study addressed an area of science instruction, POGIL in the non-majors college biology laboratory, which has yet to be qualitatively and quantitatively researched. A concurrent triangulation mixed methods approach was used. Students' understanding of biological classification was measured in two areas: scores on pre and posttests (consisting of 11 multiple choice questions), and conceptions of classification as elicited in pre and post interviews and instructor reflections. Participants were Minnesota State University, Mankato students enrolled in BIOL 100 Summer Session. One section was taught with the traditional curriculum (n = 6) and the other section in the POGIL curriculum (n = 10) developed by the researcher. Three students from each section were selected to take part in pre and post interviews. There were no significant differences within each teaching method (p familiar animal categories and aquatic habitats, unfamiliar organisms, combining and subdividing initial groupings, and the hierarchical nature of classification. The POGIL students were the only group to surpass these challenges after the teaching intervention. This study shows that POGIL is an effective technique at eliciting students' misconceptions, and addressing these misconceptions, leading to an increase in student understanding of biological classification.

  8. The effect of network biology on drug toxicology

    DEFF Research Database (Denmark)

    Gautier, Laurent; Taboureau, Olivier; Audouze, Karine Marie Laure

    2013-01-01

    Introduction: The high failure rate of drug candidates due to toxicity, during clinical trials, is a critical issue in drug discovery. Network biology has become a promising approach, in this regard, using the increasingly large amount of biological and chemical data available and combining...... it with bioinformatics. With this approach, the assessment of chemical safety can be done across multiple scales of complexity from molecular to cellular and system levels in human health. Network biology can be used at several levels of complexity. Areas covered: This review describes the strengths and limitations...... of network biology. The authors specifically assess this approach across different biological scales when it is applied to toxicity. Expert opinion: There has been much progress made with the amount of data that is generated by various omics technologies. With this large amount of useful data, network...

  9. 4.2. Medico-biological investigations and experiments on animals

    International Nuclear Information System (INIS)

    Khalikov, D.Kh.

    2012-01-01

    The hemo compatibility of cross-linked polymers was studied. Experiments were carried out on 18 healthy dogs by means of hemo sorption through hydrogels. The diagram of change of erythrocytes, leucocytes, haemoglobin, erythrocyte sedimentation rate and hematocrit rate at hemo sorption of healthy dogs is presented. Changes of peripheral blood after its passing through sorbents were considered. Changes of peripheral blood at extra corporal detoxication were studied as well. The effectiveness of hemo sorption by means of ethynyl piperidol polymers at treatment of acute radiation sickness was studied. It was found that hemo sorption by cross-linked ethynyl piperidol polymers purify the animal blood from peptide toxins.

  10. TOPICAL REVIEW: Single-molecule experiments in biological physics: methods and applications

    Science.gov (United States)

    Ritort, F.

    2006-08-01

    I review single-molecule experiments (SMEs) in biological physics. Recent technological developments have provided the tools to design and build scientific instruments of high enough sensitivity and precision to manipulate and visualize individual molecules and measure microscopic forces. Using SMEs it is possible to manipulate molecules one at a time and measure distributions describing molecular properties, characterize the kinetics of biomolecular reactions and detect molecular intermediates. SMEs provide additional information about thermodynamics and kinetics of biomolecular processes. This complements information obtained in traditional bulk assays. In SMEs it is also possible to measure small energies and detect large Brownian deviations in biomolecular reactions, thereby offering new methods and systems to scrutinize the basic foundations of statistical mechanics. This review is written at a very introductory level, emphasizing the importance of SMEs to scientists interested in knowing the common playground of ideas and the interdisciplinary topics accessible by these techniques. The review discusses SMEs from an experimental perspective, first exposing the most common experimental methodologies and later presenting various molecular systems where such techniques have been applied. I briefly discuss experimental techniques such as atomic-force microscopy (AFM), laser optical tweezers (LOTs), magnetic tweezers (MTs), biomembrane force probes (BFPs) and single-molecule fluorescence (SMF). I then present several applications of SME to the study of nucleic acids (DNA, RNA and DNA condensation) and proteins (protein-protein interactions, protein folding and molecular motors). Finally, I discuss applications of SMEs to the study of the nonequilibrium thermodynamics of small systems and the experimental verification of fluctuation theorems. I conclude with a discussion of open questions and future perspectives.

  11. Effect of high linear energy transfer radiation on biological membranes

    International Nuclear Information System (INIS)

    Choudhary, D.; Srivastava, M.; Kale, R.K.; Sarma, A.

    1998-01-01

    Cellular membranes are vital elements, and their integrity is extremely essential for the viability of the cells. We studied the effects of high linear energy transfer (LET) radiation on the membranes. Rabbit erythrocytes (1 x 10 7 cells/ml) and microsomes (0.6 mg protein/ml) prepared from liver of rats were irradiated with 7 Li ions of energy 6.42 MeV/u and 16 O ions of energy 4.25 MeV/u having maximum LET values of 354 keV/μm and 1130 keV/μm, respectively. 7 Li- and 16 O-induced microsomal lipid peroxidation was found to increase with fluence. The 16 O ions were more effective than 7 Li ions, which could be due to the denser energy distribution in the track and the yield of free radicals. These findings suggested that the biological membranes could be peroxidized on exposure to high-LET radiation. Inhibition of the lipid peroxidation was observed in the presence of a membrane-active drug, chlorpromazine (CPZ), which could be due to scavenging of free radicals (mainly HO. and ROO.), electron donation, and hydrogen transfer reactions. The 7 Li and 16 O ions also induced hemolysis in erythrocytes. The extent of hemolysis was found to be a function of time and fluence, and showed a characteristic sigmoidal pattern. The 16 O ions were more effective in the lower fluence range than 7 Li ions. These results were compared with lipid peroxidation and hemolysis induced by gamma-radiation. (orig.)

  12. Nanogold – Biological effects and occupational exposure levels

    Directory of Open Access Journals (Sweden)

    Anna Maria Świdwińska-Gajewska

    2017-08-01

    Full Text Available Nanogold has different properties and biological activity compared to metallic gold. It can be applied in many fields, such as medicine, laboratory diagnostics and electronics. Studies on laboratory animals show that nanogold can be absorbed by inhalation and ingestion. It can penetrate deep into the epidermis and dermis, but there is no evidence that it is absorbed through the skin. Gold nanoobjects accumulate mainly in the liver and spleen, but they can also reach other internal organs. Nanogold can cross the blood–brain and blood–placenta barriers. Toxicokinetics of nanogold depends on the particle size, shape and surface charge. In animals exposure to gold nanoparticles via inhalation induces slight changes in the lungs. Exposure to nanogold by the oral route does not cause adverse health effects in rodents. In animals after injection of gold nanoobjects changes in the liver and lungs were observed. Nanogold induced genotoxic effects in cells, but not in animals. No adverse effects on the fetus or reproduction were found. There are no carcinogenicity studies on gold nanoparticles. The mechanism of toxicity may be related to the interaction of gold nanoobjects with proteins and DNA, and it leads to the induction of oxidative stress and genetic material damage. The impact of nanostructures on human health has not yet been fully understood. The person, who works with nanomaterials should exercise extreme caution and apply existing recommendations on the evaluation of nanoobjects exposure. The risk assessment should be the basis for taking appropriate measures to limit potential exposure to nanometals, including nanogold. Med Pr 2017;68(4:545–556

  13. Biological effects of space-induced mutation on robinia pseudoacacia

    International Nuclear Information System (INIS)

    Yuan Cunquan; Li Yun; Lu Chao; Yang Min; Zhang Yuyao

    2010-01-01

    Dry seeds of Robinia pseudoacacia were carried by Shijian No.8 breeding satellite for mutagenesis and the biological effect of space-induced mutation was studied. The parameters of Robinia pseudoacacia such as plant height, stem base, branch number, knot spacing, length of thorn and chlorophyll content were analyzed, and, at the same time, the genetic diversity was tested by SSR marker. The results showed that the plant height and stem base of 2-year-old seedlings which derived from space mutagenesis were 22.0% and 24.1% lower than those of control, and 3-year-old seedlings were 13.1% and 22.4% lower than those of control, respectively. While the inhibiting effect of plant height became undermined in the following growth years. However, the inhibiting effect in stem base existed all the time,the length of thorn of branch and stem were 15.6% and 28.6% shorter than the control,respectively. Compared with the control,the variation of the length of thorn from stem was extremely significant. The variation of chlorophyll a content from space mutagenesis compared with control was not remarkable, while the total chlorophyll and chlorophyll b contents were 18.7% and 9.7% lower than those of control, respectively, and the difference between space mutagenesis and control was significant. While the chlorophyll a/b was 25.6% higher than that of control, but the difference was not significant. The coefficient of variation of the relative traits was increased by the space mutagenesis. The extensively population genome mutation after space-induction were not detected by SSR (Simple Sequence Repeats). (authors)

  14. Physical grounds for biological effect of laser radiation

    International Nuclear Information System (INIS)

    Rubinov, A N

    2003-01-01

    A new approach to the understanding of biological activity caused by low-intensity laser radiation, in which coherence is a factor of paramount importance, has been developed. It is based on the dipole interaction of gradient laser fields with cells, organelles and membranes. The laser intensity gradients in an object arise due to the interference of the light scattered by the tissue with the incident light beam (speckle formation). Apart from speckles, different types of light spatial modulation can be created deliberately using different schemes for beam interference. It is shown that gradient laser fields may cause spatial modulation of the concentration of particles and increase their 'partial temperature'. This paper presents the results of experimental observation of trapping of different types of particles, including human lymphocytes, in the interference fields of the He-Ne laser. The sweep-net effect on particles of different sizes on moving the laser field is demonstrated and crystal-like self-organization of particles in the laser gradient field is observed. The influence of gradient laser fields on erythrocyte rouleaus, on the apoptosis of human lymphocytes as well as on their chromosome aberrations is demonstrated. It may be concluded from the experimental studies that the influence of an interference laser field with a rightly chosen period can stimulate the repair system of a cell, increasing its viability

  15. Biological effects of simple changes in functionality on rhodium metalloinsertors

    Science.gov (United States)

    Weidmann, Alyson G.; Komor, Alexis C.; Barton, Jacqueline K.

    2013-01-01

    DNA mismatch repair (MMR) is crucial to ensuring the fidelity of the genome. The inability to correct single base mismatches leads to elevated mutation rates and carcinogenesis. Using metalloinsertors–bulky metal complexes that bind with high specificity to mismatched sites in the DNA duplex–our laboratory has adopted a new chemotherapeutic strategy through the selective targeting of MMR-deficient cells, that is, those that have a propensity for cancerous transformation. Rhodium metalloinsertors display inhibitory effects selectively in cells that are deficient in the MMR machinery, consistent with this strategy. However, a highly sensitive structure–function relationship is emerging with the development of new complexes that highlights the importance of subcellular localization. We have found that small structural modifications, for example a hydroxyl versus a methyl functional group, can yield profound differences in biological function. Despite similar binding affinities and selectivities for DNA mismatches, only one metalloinsertor shows selective inhibition of cellular proliferation in MMR-deficient versus -proficient cells. Studies of whole-cell, nuclear and mitochondrial uptake reveal that this selectivity depends upon targeting DNA mismatches in the cell nucleus. PMID:23776288

  16. Relative Biological Effectiveness and Peripheral Damage of Antiproton Annihilation

    CERN Multimedia

    Kavanagh, J N; Kaiser, F; Tegami, S; Schettino, G; Kovacevic, S; Hajdukovic, D; Knudsen, H; Currell, F J; Toelli, H T; Doser, M; Holzscheiter, M; Herrmann, R; Timson, D J; Alsner, J; Landua, R; Comor, J; Moller, S P; Beyer, G

    2002-01-01

    The use of ions to deliver radiation to a body for therapeutic purposes has the potential to be significant improvement over the use of low linear energy transfer (LET) radiation because of the improved energy deposition profile and the enhanced biological effects of ions relative to photons. Proton therapy centers exist and are being used to treat patients. In addition, the initial use of heavy ions such as carbon is promising to the point that new treatment facilities are planned. Just as with protons or heavy ions, antiprotons can be used to deliver radiation to the body in a controlled way; however antiprotons will exhibit additional energy deposition due to annihilation of the antiprotons within the body. The slowing down of antiprotons in matter is similar to that of protons except at the very end of the range beyond the Bragg peak. Gray and Kalogeropoulos estimated the additional energy deposited by heavy nuclear fragments within a few millimeters of the annihilation vertex to be approximately 30 MeV (...

  17. Biological effect of hydrolyzed collagen on bone metabolism.

    Science.gov (United States)

    Daneault, Audrey; Prawitt, Janne; Fabien Soulé, Véronique; Coxam, Véronique; Wittrant, Yohann

    2017-06-13

    Osteoporosis is a chronic and asymptomatic disease characterized by low bone mass and skeletal microarchitectural deterioration, increased risk of fracture, and associated comorbidities most prevalent in the elderly. Due to an increasingly aging population, osteoporosis has become a major health issue requiring innovative disease management. Proteins are important for bone by providing building blocks and by exerting specific regulatory function. This is why adequate protein intake plays a considerable role in both bone development and bone maintenance. More specifically, since an increase in the overall metabolism of collagen can lead to severe dysfunctions and a more fragile bone matrix and because orally administered collagen can be digested in the gut, cross the intestinal barrier, enter the circulation, and become available for metabolic processes in the target tissues, one may speculate that a collagen-enriched diet provides benefits for the skeleton. Collagen-derived products such as gelatin or hydrolyzed collagen (HC) are well acknowledged for their safety from a nutritional point of view; however, what is their impact on bone biology? In this manuscript, we critically review the evidence from literature for an effect of HC on bone tissues in order to determine whether HC may represent a relevant alternative in the design of future nutritional approaches to manage osteoporosis prevention.

  18. Thorotrast: A Bibliography of its Diagnostic Use and Biological Effects

    International Nuclear Information System (INIS)

    1964-01-01

    This bibliography has been compiled primarily to support a study of Thorotrast toxicity which is being conducted in the Medical Section of the International Atomic Energy Agency. The limited resources of staff and time available for its compilation have dictated a practical compromise between completeness and freedom from error on the one hand and effort on the other. While neither complete nor free of error, it has been stencilled so as to be available to other groups with similar interests. Additions and corrections would be gratefully received. The chief concern of the bibliography is with the toxic effects of Thorotrast. Papers on the diagnostic use of Thorotrast have also been included, both because of their relevance to the subsequent toxic effects and because of the light they shed on the possible numbers and location of Thorotrast cases. Papers on various related topics such as ThX (Ra-224) and MsTh (Ra-228) have been included when found, but no special search for them has been made. Papers are classified under the topics shown in the Table of Contents. In many cases papers have been listed under two or more categories, but a unique classification is obviously impossible. Since a rather abrupt change in outlook on the biological significance of ionizing radiation took place with the advent of nuclear energy, papers are given separately under each topic according to publication dates 1945 and earlier, 1946 and later. Original titles (if available) are given along with their English translations. Authors' addresses are listed for papers of which reprints have been obtained by the Agency.

  19. Thorotrast: A Bibliography of its Diagnostic Use and Biological Effects

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1964-03-16

    This bibliography has been compiled primarily to support a study of Thorotrast toxicity which is being conducted in the Medical Section of the International Atomic Energy Agency. The limited resources of staff and time available for its compilation have dictated a practical compromise between completeness and freedom from error on the one hand and effort on the other. While neither complete nor free of error, it has been stencilled so as to be available to other groups with similar interests. Additions and corrections would be gratefully received. The chief concern of the bibliography is with the toxic effects of Thorotrast. Papers on the diagnostic use of Thorotrast have also been included, both because of their relevance to the subsequent toxic effects and because of the light they shed on the possible numbers and location of Thorotrast cases. Papers on various related topics such as ThX (Ra-224) and MsTh (Ra-228) have been included when found, but no special search for them has been made. Papers are classified under the topics shown in the Table of Contents. In many cases papers have been listed under two or more categories, but a unique classification is obviously impossible. Since a rather abrupt change in outlook on the biological significance of ionizing radiation took place with the advent of nuclear energy, papers are given separately under each topic according to publication dates 1945 and earlier, 1946 and later. Original titles (if available) are given along with their English translations. Authors' addresses are listed for papers of which reprints have been obtained by the Agency.

  20. Calculation of the biological effect of fractionated radiotherapy: the importance of radiation-induced apoptosis

    International Nuclear Information System (INIS)

    Olsen, D.R.

    1995-01-01

    The total effect (TE) has been calculated for two different fractionation formalisms: the consecutive and repetitive fractionation mechanism, using a modified linear quadratic (LQ) model which includes the effect of apoptosis. For a given total dose, an increase in TE is seen when increasing the dose per fraction as well as the apoptotic fraction (F a ). Also, the TE increases with increasing α/β ratio (of the modified LQ model). The ratio of TE for tumour tissue and TE for late reacting tissue is calculated assuming the absence of apoptosis in late reacting tissue and a common value of α/β (of the modified LQ model). The biological effect ratio (BR) is higher for a large F a and low doses per fraction, than for large doses per fraction and a small F a . Assuming a consecutive fractionation mechanism, the TE formalism is unable to predict a log cell kill of more than 3 for β values of 0.010-0.028. It is less dependent on dose per fraction and F a than the repetitive fractionation mechanism. The biological effect ratio is only slightly higher than 1, and is less influenced by F a , dose per fraction and α/β ratio. A repetitive fractionation mechanism is also consistent with the preliminary results of published fractionation experiments. The calculations indicate that designing fractionation regimes for optimization of biological effect is a process where the role of apoptotic cell inactivation must be maximized, and where the influence of mitotic cell inactivation may be of less importance. (author)

  1. Biological and technological effects of some mulberry varieties and ...

    African Journals Online (AJOL)

    egyptian hak

    The relatively new technique of outline-based geometric morphometrics was applied in a study of the variation in the .... Institute of Math Problems of Biology, Moscow Region, Russia (program). ... PhD Thesis, University of Montellier II. Orsini P ...

  2. Biological and technological effects of some mulberry varieties and ...

    African Journals Online (AJOL)

    egyptian hak

    The major sources of aluminum include air, food and water (Michel 1990), and ... Vitamin C is essential for the formation of collagen and intracellular material, ..... Packer L (1993) Vitamin E: biological activity and health benefits: Overview. p.

  3. Biological and technological effects of some mulberry varieties and ...

    African Journals Online (AJOL)

    egyptian hak

    These water blooms are of tremendous biological significance .... have long been known for their potential use in agriculture as biofertilizer, soil ... applications (e.g. in agriculture, industry, pharmaceuticals). Studies .... solanaceous vegetables.

  4. Sex matters: The effects of biological sex on adipose tissue biology and energy metabolism

    Directory of Open Access Journals (Sweden)

    Teresa G. Valencak

    2017-08-01

    Full Text Available Adipose tissue is a complex and multi-faceted organ. It responds dynamically to internal and external stimuli, depending on the developmental stage and activity of the organism. The most common functional subunits of adipose tissue, white and brown adipocytes, regulate and respond to endocrine processes, which then determine metabolic rate as well as adipose tissue functions. While the molecular aspects of white and brown adipose biology have become clearer in the recent past, much less is known about sex-specific differences in regulation and deposition of adipose tissue, and the specific role of the so-called pink adipocytes during lactation in females. This review summarises the current understanding of adipose tissue dynamics with a focus on sex-specific differences in adipose tissue energy metabolism and endocrine functions, focussing on mammalian model organisms as well as human-derived data. In females, pink adipocytes trans-differentiate during pregnancy from subcutaneous white adipocytes and are responsible for milk-secretion in mammary glands. Overlooking biological sex variation may ultimately hamper clinical treatments of many aspects of metabolic disorders. Keywords: Body fatness, Adipose tissue, Sex-specific differences, Adipokines, Adipocytes, Obesity, Energy metabolism

  5. THE EFFECTS OF USING EDMODO IN BIOLOGY EDUCATION ON STUDENTS’ ATTITUDES TOWARDS BIOLOGY AND ICT

    Directory of Open Access Journals (Sweden)

    Veronika Végh

    2017-10-01

    Full Text Available ICT has gained a vital role within education, helping to facilitate the teaching-learning process. This paper examines the efficacy of the Edmodo interface within biology education in high schools. Two 10th grade classes were studied for a one semester period. Both classes followed the same curriculum, however Edmodo usage was compulsory for the experimental class. Anonymous pre-and post-test questionnaires were filled out by the students and statistically analyzed. The research included 58 students; 34 females and 24 males. Over the course of the semester, the experimental group developed increased feelings of importance towards Biology, whereas no change was observed in the control group. At the end of the semester, the experimental group scores leant favorable towards the positive impact of Edmodo use in the classroom, in comparison to the control group. These results show a positive impact of using Edmodo in the classroom, as a facilitative tool, to improve student comprehension in the participating Hungarian students.

  6. Biological effects of combined resveratrol and vitamin D3 on ovarian tissue.

    Science.gov (United States)

    Uberti, Francesca; Morsanuto, Vera; Aprile, Silvio; Ghirlanda, Sabrina; Stoppa, Ian; Cochis, Andrea; Grosa, Giorgio; Rimondini, Lia; Molinari, Claudio

    2017-09-15

    Resveratrol (3,5,4'-trihydroxy-trans-stilbene) is a natural antioxidant polyphenol able to exert a wide range of biological effect on several tissues. Despite its important beneficial properties, it has a low water solubility, which limits its therapeutic applications in humans. Resveratrol also acts as a phytoestrogen that modulates estrogen receptor (ER)-mediated transcription. In addition, it has been shown that ovarian tissues benefit greatly from vitamin D3, which exerts its beneficial effects through VDR receptors. The aim was to evaluate the cooperative effects of resveratrol combined with vitamin D3 on ovarian cells and tissues and some other organs as well. Moreover, the modulation of specific intracellular pathways involving ER and VDR receptors has been studied. The experiments were performed both in vitro and in vivo, to analyze cell viability, radical oxygen species production, signal transductions through Western Blot, and resveratrol quantification by HPLC. Cell viability, radical oxygen species production, and intracellular pathways have been studied on CHO-K1 cells. Also, the relative mechanism activated following oral intake in female Wistar rats as animal model was investigated, evaluating bioavailability, biodistribution and signal transduction in heart, kidney, liver and ovarian tissues. Both in in vitro and in vivo experiments, resveratrol exerts more evident effects when administered in combination with vitD in ovarian cells, showing a common biphasic cooperative effect: The role of vitamin D3 in maintaining and supporting the biological activity of resveratrol has been clearly observed. Moreover, resveratrol plus vitamin D3 blood concentrations showed a biphasic absorption rate. Such results could be used as a fundamental data for the development of new therapies for gynecological conditions, such as hot-flashes.

  7. Experiment, theory and the Casimir effect

    International Nuclear Information System (INIS)

    Mostepanenko, V M

    2009-01-01

    Several problems at the interface between the field-theoretical description of the Casimir effect and experiments on measuring the Casimir force are discussed. One of these problems is connected with the definition of the Casimir free energy in ideal metal rectangular boxes satisfying the general physical requirements. It is shown that the consideration of rectangular boxes with a partition (piston) does not negate the previously known results obtained for boxes without a piston. Both sets of results are found to be in mutual agreement. Another problem is related to the use of the proximity force approximation for the interpretation of the experimental data and to the search of analytical results beyond the PFA based on the first principles of quantum field theory. Next, we discuss concepts of experimental precision and of the measure of agreement between experiment and theory. The fundamental difference between these two concepts is clarified. Finally, recent approach to the thermal Casimir force taking screening effects into account is applied to real metals. It is shown that this approach is thermodynamically and experimentally inconsistent. The physical reasons of this inconsistency are connected with the violation of thermal equilibrium which is the basic applicability condition of the Lifshitz theory.

  8. The Effects of Ultrasound on Biological Systems: Site

    Science.gov (United States)

    El-Karmi, Anan M.

    vs. 18 minutes). This demonstrates that the biological effects of ultrasound are influenced by Ca^ {2+}. The larger increases in G _{rm t} and the time constants confirm other studies addressing the role of Ca ^{2+} in potentiating lipid peroxidation by free radicals, and the role of calcium ions in the formation of tight junctions.

  9. Biological effect of Pulsed Dose Rate brachytherapy with stepping sources

    International Nuclear Information System (INIS)

    Limbergen, Erik F.M. van; Fowler, Jack F.

    1996-01-01

    Purpose: To explore the possible increase of radiation effect in tissues irradiated by pulsed brachytherapy (PDR), for local tissue dose-rates between those 'averaged over the whole pulse' and the instantaneous high dose rates close to the dwell positions. An earlier publication (Fowler and Mount 1992) had shown that, for dose rates (averaged for the duration of the pulse) up to 3 Gy/h, little change of isoeffect doses from continuous low dose rate (CLDR) are expected, unless larger doses per fraction than 1 Gy are used, and especially if components of very rapid repair are present with half-times of less than about 0.5 hours. However, local and transient dose rates close to stepping sources can be up to several Gy per minute. Methods: Calculations were done assuming the linear quadratic formula for radiation damage, in which only the dose-squared term is subject to repair, at a constant exponential rate. The formula developed by Dale for fractionated low-dose-rate radiotherapy was used. A constant overall time of 140 hours and constant total dose of 70 Gy were assumed throughout, the continuous low dose-rate of 0.5 Gy/h (CLDR) providing the unitary standard effects for each PDR condition. Effects of dose-rates ranging from 4 Gy/h to 120 Gy/h (HDR at 2 Gy/min) were studied, and T (1(2)) from 4 minutes to 1.5 hours. Results: Curves are presented relating the ratio of increased biological effect (proportional to log cell kill) calculated for PDR relative to CLDR. Ratios as high as 1.5 can be found for large doses per pulse (> 1 Gy) at high instantaneous dose-rates if T (1(2)) in tissues is as short as a few minutes. The major influences on effect are dose per pulse, half-time of repair in the tissue, and - when T (1(2)) is short - the instantaneous dose-rate. Maximum ratios of PDR/CLDR effect occur when the dose-rate is such that pulse duration is approximately equal to T (1(2)) of repair. Results are presented for late-responding tissues, the differences from CLDR

  10. Countermeasures for Space Radiation Induced Malignancies and Acute Biological Effects

    Science.gov (United States)

    Kennedy, Ann

    The hypothesis being evaluated in this research program is that control of radiation induced oxidative stress will reduce the risk of radiation induced adverse biological effects occurring as a result of exposure to the types of radiation encountered during space travel. As part of this grant work, we have evaluated the protective effects of several antioxidants and dietary supplements and observed that a mixture of antioxidants (AOX), containing L-selenomethionine, N-acetyl cysteine (NAC), ascorbic acid, vitamin E succinate, and alpha-lipoic acid, is highly effective at reducing space radiation induced oxidative stress in both in vivo and in vitro systems, space radiation induced cytotoxicity and malignant transformation in vitro [1-7]. In studies designed to determine whether the AOX formulation could affect radiation induced mortality [8], it was observed that the AOX dietary supplement increased the 30-day survival of ICR male mice following exposure to a potentially lethal dose (8 Gy) of X-rays when given prior to or after animal irradiation. Pretreatment of animals with antioxidants resulted in significantly higher total white blood cell and neutrophil counts in peripheral blood at 4 and 24 hours following exposure to doses of 1 Gy and 8 Gy. Antioxidant treatment also resulted in increased bone marrow cell counts following irradiation, and prevented peripheral lymphopenia following 1 Gy irradiation. Supplementation with antioxidants in irradiated animals resulted in several gene expression changes: the antioxidant treatment was associated with increased Bcl-2, and decreased Bax, caspase-9 and TGF-β1 mRNA expression in the bone marrow following irradiation. These results suggest that modulation of apoptosis may be mechanistically involved in hematopoietic system radioprotection by antioxidants. Maintenance of the antioxidant diet was associated with improved recovery of the bone marrow following sub-lethal or potentially lethal irradiation. Taken together

  11. Ionizing radiation biological effects and the proper protective measures against it's harmful effects

    International Nuclear Information System (INIS)

    Hhalel, A.M.

    1990-01-01

    This book intrduces a good knowledge in specifications of ionizing radiation biological effects and the proper protective measures againest harmful effectes. The book is devided in to five main sections, the first one introduces the hostorical bachground of the contributions of a number of scietists in the basic knolwledge of radiation and its biological effects. The second section deals with the physical and chemical principles of radiation the third one talks about radiation detection. While the fourth section talks (via seven chapter) about the effectes of ionizing radiation on living organisms molecules cells, tissues organs systems and the living organism the fifth section talks about the uses of radiation sources, the probability of radiation accidents, protective measures, international recommendations related to doses and safe use of ionizing radiation. (Abed Al-wali Al-ajlouni). 53 refs., 107 figs., 13 tabs

  12. Development of a filtered neutron field in KUR. In behalf of biological irradiation experiments

    International Nuclear Information System (INIS)

    Sato, Takashi; Utsuro, Masahiko; Utsumi, Hiroshi

    1995-07-01

    Very little direct measurements have been made of the biological effects of neutrons below 100keV. Recently, an iron-filtered 24keV neutron beam of Harwell Materials Testing Reactor, PLUTO, was reported to be highly efficient in inducing chromosome aberrations; the efficiency being comparable to that of fission neutrons. This results could have serious repercussions for radiation protection standards as the ICRP assume a decrease in neutron RBE below 100keV. The investigations reported here have as their primary purpose the production of neutron beams at the 24keV iron window energy, using the B-1 experimental facility of the Kyoto University Research Reactor (KUR) at the Research Reactor Institute, Kyoto University (KURRI). The filtered neutron filed for biomedical applications is designed to maximized the contributions of neutrons with other energies and gamma-rays. The characteristics of the radiation field were obtained by the simple transmission calculations for Fe(45cm) and Al(35cm) filters, by using the Monte Carlo code MCN P, and by the measurement of nuclear heating for Fe and Al filter pieces. The 24keV neutron flux and gamma-ray dose rate were measured using a proton recoil counter and TLDs, respectively. The measured findings are as follows: The 24keV neutron flux at the irradiation field was approximately 1x10 6 n/cm 2 /s, and the gamma-ray dose rate was 1.0Gy/h at the surface of the B-1 plug. Nuclear heating of the filter materials was 5.2mW/g for Fe and 4mW/g for Al, in maximum. (author)

  13. Multifactorial and microdosimetrical analysis of the biological influence of galactic cosmic rays on Bacillus subtilis spores in the biostack experiment

    International Nuclear Information System (INIS)

    Facius, R.

    1981-01-01

    In this paper a partial experiment is presented which has been performed during several years and several space flight missions. This experiment is part of a research program to study the radiation biological - and in particular the medical relevance of the 'hard' cosmic ray component. The identification of particles (Z, LET, E) was not hindered by the combination with biological objects and could be performed with sufficient accuracy. Refering to semi-empirical findings the distribution of LET values in the bacillus subtilis could be determined in agreement with other experimental results. The localisation and correlation of particle tracks with the individual cells of the target regions is significant. As a result the LET does not seem to be an important parameter for the biological activity within the parameter range studied here. The energy deposition in the spores by delta-electrons could be calculated on the basis of a microdosimetrical analysis. A more detailed analysis was essentially hampered by an insufficient accuracy for the measurement of the distance between particle tracks and the spores. Thus a dose-survival-curve could not be established. In spite of that the relative biological activity (RBW) has been estimated on the basis of density distributions. The failure of these experiments, a review of the relevant literature, and a detailed discussion contribute essentially to the problem of the existence of specific mechanisms for heavy ions and their radiation biological activity. According to the actual knowledge the existence of such a mechanism in addition to delta-electrons has to be considered as most probable. (orig./MG) [de

  14. The effect of workshop groups on achievement goals and performance in biology: An outcome evaluation

    Science.gov (United States)

    Born, Wendi Kay

    This two-year quasi-experiment evaluated the effect of peer-led workshop groups on performance of minority and majority undergraduate biology students in a three-course series and investigated motivational explanations for performance differences. The workshop intervention used was modeled after a program pioneered by Treisman (1992) at the University of California. Majority volunteers randomly assigned to workshops (n = 61) performed between 1/2 and 1 standard deviation better than those assigned to the control group (n = 60; p challenge interventions can be highly beneficial for both majority and minority participants and that institutions can promote excellence by incorporating workshop programs like the one described here. These interventions have been shown to be more effective and cost less than remedial interventions.

  15. Biological Effects and Biodistribution of Bufotenine on Mice

    Directory of Open Access Journals (Sweden)

    Hugo Vigerelli

    2018-01-01

    Full Text Available Bufotenine is an alkaloid derived from serotonin, structurally similar to LSD and psilocin. This molecule is able to inhibit the rabies virus infection in in vitro and in vivo models, increasing the survival rate of infected animals. Being a very promising molecule for an incurable disease and because of the fact that there is no consensus regarding its neurological effects, this study aimed to evaluate chronic treatment of bufotenine on behavior, pathophysiology, and pharmacokinetics of mice. Animals were daily treated for 21 consecutive days with 0.63, 1.05, and 2.1 mg/animal/day bufotenine and evaluated by open field test and physiological parameters during all the experiment. After this period, organs were collected for histopathological and biodistribution analysis. Animals treated with bufotenine had mild behavioral alterations compared to the control group, being dose-response relationship. On the other hand, animals showed normal physiological functions and no histological alterations in the organs. With high doses, an inflammatory reaction was observed in the site of injection, but with no cellular damage. The alkaloid could be found in the heart and kidney with all doses and in the lungs and brain with higher doses. These results show that the effective dose, 0.63 mg/day, is safe to be administered in mice, since it did not cause significant effects on the animals’ physiology and on the CNS. Higher doses were well tolerated, causing only mild behavioral effects. Thus, bufotenine might be a drug prototype for rabies treatment, an incurable disease.

  16. Some biological effects of one water based ferrofluid in cucurbita pepo

    International Nuclear Information System (INIS)

    Racuciu, M.; Creanga, D.; Olteanu, Z.; Horga, E. I.

    2005-01-01

    Full text: The biological interest in the ferrofluid effect in living organisms represents an important application field, mainly for biotechnological use, since the small ferrophase size allows the penetration through the biological membranes. Experiments have been designed to reveal the influences of an aqueous ferrofluid on the assimilatory pigments, the peroxide level, nucleic acid level and on the substance accumulation. Water based ferrofluid, stabilized with citric acid was added in various concentrations (10-50-100- 150-200-250 micro L/L) (after vigorous shaking) in the culture medium of Cucurbita pepo plantlets (pumpkin). Spectrophotometric standard assay methods have been applied in order to get experimental data regarding the levels of assimilatory pigments (chlorophyll a, chlorophyll b, carotenes), nucleic acids and peroxydase like enzymes. JASCO V350 spectrophotometer provided with. The stimulatory effect of relatively high ferrofluid concentrations have been observed in the ratio chlorophyll a/b, known as a measure of photosynthesis ratio. Non-significant changes in the nucleic acid level were noticed. Inhibitory effect upon the enzyme biosynthesis was assigned to the ferrofluid addition. The statistic analysis was accomplished by considering five repetitions of every measurement in ferrofluid samples and control ones. Average values of ferrofluid samples and control ones have been compared by means of t-test. Statistic significance was revealed in comparison to the significance threshold of 0.05. (Also one figure included.) References: [1] C. Gro , K.Buescher, E. Romanus, C,A, Helm, W.Weitschies, European cells and Materials, 2002, 3(2), 163. [2] M.M.Zamfirache, G. Capraru, D. Creanga, M. Racuciu, Gh. Calugaru, Ferrofluid experiment for simulating pollution effect on plant growth, The Annals of University Galati, 2004(XXVII), Fasc.II, 37. [3] A.Goodarzi, Y.Sahoo, M.T.Swihart, P.N. Prasad, Mat.Res.Soc.Symp.Proc., 2004,Vol.789, N6.6.1

  17. Essential Oils from Thyme (Thymus vulgaris): Chemical Composition and Biological Effects in Mouse Model.

    Science.gov (United States)

    Vetvicka, Vaclav; Vetvickova, Jana

    2016-12-01

    Thymus species are popular spices and contain volatile oils as main chemical constituents. Recently, plant-derived essential oils are gaining significant attention due to their significant biological activities. Seven different thymus-derived essential oils were compared in our study. First, we focused on their chemical composition, which was followed up by testing their effects on phagocytosis, cytokine production, chemotaxis, edema inhibition, and liver protection. We found limited biological activities among tested oils, with no correlation between composition and biological effects. Similarly, no oils were effective in every reaction. Based on our data, the tested biological use of these essential oils is questionable.

  18. Biological effectiveness and application of heavy ions in radiation therapy described by a physical and biological model

    International Nuclear Information System (INIS)

    Olsen, K.J.; Hansen, J.W.

    1982-12-01

    A description is given of the physical basis for applying track structure theory in the determination of the effectiveness of heavy-ion irradiation of single- and multi-hit target systems. It will be shown that for applying the theory to biological systems the effectiveness of heavy-ion irradiation is inadequately described by an RBE-factor, whereas the complete formulation of the probability of survival must be used, as survival depends on both radiation quality and dose. The theoretical model of track structure can be used in dose-effect calculations for neutron-, high-LET, and low-LET radiation applied simultaneously in therapy. (author)

  19. Radiation hazards and biological effects of ionising radiation on man

    International Nuclear Information System (INIS)

    Siti Najila Mohd Janib

    2004-01-01

    The contents of this chapter are follows - Mechanism of damage: direct action of radiation, indirect action of radiation. Classification of effects: somatic effect, induction of cancer, factors, affecting somatic effects, genetic effect, inherited abnormalities, induced effects, early effects, late effects, deterministic effect, stochastic effect. Effect of specific group: development abnormality, childhood Cancer, fertile women, risk and uncertainty, comparison of risk

  20. Biological effects of low-dose ionizing radiation exposure; Biologische Wirkungen niedriger Dosen ionisierender Strahlung

    Energy Technology Data Exchange (ETDEWEB)

    Reinoehl-Kompa, Sabine; Baldauf, Daniela; Heller, Horst (comps.)

    2009-07-01

    The report on the meeting of the Strahlenschutzkommission 2007 concerning biological effects of low-dose ionizing radiation exposure includes the following contributions: Adaptive response. The importance of DNA damage mechanisms for the biological efficiency of low-energy photons. Radiation effects in mammography: the relative biological radiation effects of low-energy photons. Radiation-induced cataracts. Carcinomas following prenatal radiation exposure. Intercellular apoptosis induction and low-dose irradiation: possible consequences for the oncogenesis control. Mechanistic models for the carcinogenesis with radiation-induced cell inactivation: application to all solid tumors in the Japanese atomic bomb survivors. Microarrays at low radiation doses. Mouse models for the analysis of biological effects of low-dose ionizing radiation. The bystander effect: observations, mechanisms and implications. Lung carcinoma risk of Majak workers - modeling of carcinogenesis and the bystander effect. Microbeam studies in radiation biology - an overview. Carcinogenesis models with radiation-induced genomic instability. Application to two epidemiological cohorts.

  1. Biological and technological effects of some mulberry varieties and ...

    African Journals Online (AJOL)

    egyptian hak

    environment. Evolution 50: 434-437. Mahmoud MAM, Zalat SM, El-Akkad SS & Gilbert F (2008) Genetic variability in the endemic bee Anthophora pauperata among wadis in St Katherine Protectorate. Egyptian Journal of Biology 10: 77-86. Marden JH (1989) Bodybuilding dragonflies: costs and benefits of maximizing flight ...

  2. Effect of gamma irradiation on biological activity of thyrotropin

    Energy Technology Data Exchange (ETDEWEB)

    Strbak, V; Macho, L; Sedlak, J; Hromadova, M

    1976-03-01

    The biological activity of thyrotropin (TSH) was tested after sterilization by 0.5 and 12.5 Mrad of gamma irradiation. It was found that the biological activity (McKenzie's assay) of TSH irradiated in dry state was not affected during the first month after sterilization by doses of 0.5 and 2.5 Mrad. However, substantial decrease of TSH biological activity was observed 3 to 5 months after the irradiation, the lower activity being after the former dose. The irradiation of TSH by 12.5 Mrad in dry state and by 0.5 and 2.5 Mrad in solution resulted in a decrease of biological activity already during first month. The structural changes in the molecule of TSH were apparently not very extensive, since a decrease of disulfide bonds from 0.96 to 0.77 M per 1M of TSH was found immediately after the irradiation, while uv absorbancy and electrophoretic mobility on polyacrylamide gel electrophoresis were unaffected. These changes were followed by the decrease of TSH stability during storage in dry state. It is hypothesized that TSH molecule may be affected in ..beta.. subunit or in its connection with ..cap alpha...

  3. Effects Of Advance Organizers On Students\\' Achievement In Biology ...

    African Journals Online (AJOL)

    Science Education is emphasized in school curriculum in order to meet the country\\'s socioeconomic needs by producing a scientifically literate populace and professionals in science and technology based careers. Biology as a science subject is expected to make a contribution towards these objective. However, the ...

  4. Effect of gamma irradiation on biological activity of thyrotropin

    International Nuclear Information System (INIS)

    Strbak, V.; Macho, L.; Sedlak, J.; Hromadova, M.

    1976-01-01

    The biological activity of thyrotropin (TSH) was tested after sterilization by 0.5 and 12.5 Mrad of gamma radiation. It was found that the biological activity (McKenzie's assay) of TSH irradiated in dry state was not affected during the first month after sterilization by doses of 0.5 and 2.5 Mrad. However, substantial decrease of TSH biological activity was observed 3 to 5 months after the irradiation, the lower activity after the 0.5 Mrad dose. The irradiation of TSH by 12.5 Mrad in dry state and by 0.5 and 2.5 Mrad in solution resulted in decreased biological activity already during the first month. The structural changes in the TSH molecule were apparently not very extensive, as a decrease of disulfide bonds from 0.96 to 0.77 M per 1 M of TSH was found immediately after the irradiation, while UV absorbancy and electrophoretic mobility on polyacrylamide gel electrophoresis were unaffected. These changes were followed by a decrease of TSH stability during storage in dry state. It is hypothesized that a TSH molecule may be affected in a β subunit or in its connection with α. (author)

  5. Filter media expansion during backwash: The effect of biological ...

    African Journals Online (AJOL)

    provided by the designer or that the mechanical behaviour of the media gradually changes after being placed in the filters. A number of media tests confirmed that the biological fraction of the specific deposit on the filter media (after backwashing) is relatively high – about 50% of the total specific deposit. This led to the ...

  6. Neuroimaging of the joint Simon effect with believed biological and non-biological co-actors

    Directory of Open Access Journals (Sweden)

    Tanya eWen

    2015-09-01

    Full Text Available Performing a task alone or together with another agent can produce different outcomes. The current study used event-related functional magnetic resonance imaging (fMRI to investigate the neural underpinnings when participants performed a Go/Nogo task alone or complementarily with another co-actor (unseen, whom was believed to be another human or a computer. During both complementary tasks, reaction time data suggested that participants integrated the potential action of their co-actor in their own action planning. Compared to the single-actor task, increased parietal and precentral activity during complementary tasks as shown in the fMRI data further suggested representation of the co-actor’s response. The superior frontal gyrus of the medial prefrontal cortex was differentially activated in the human co-actor condition compared to the computer co-actor condition. The medial prefrontal cortex, involved thinking about the beliefs and intentions of other people, possibly reflects a social-cognitive aspect or self-other discrimination during the joint task when believing a biological co-actor is present. Our results suggest that action co-representation can occur even offline with any agent type given a priori information that they are co-acting; however additional regions are recruited when participants believe they are task-sharing with another human.

  7. Neuroimaging of the joint Simon effect with believed biological and non-biological co-actors.

    Science.gov (United States)

    Wen, Tanya; Hsieh, Shulan

    2015-01-01

    Performing a task alone or together with another agent can produce different outcomes. The current study used event-related functional magnetic resonance imaging (fMRI) to investigate the neural underpinnings when participants performed a Go/Nogo task alone or complementarily with another co-actor (unseen), whom was believed to be another human or a computer. During both complementary tasks, reaction time data suggested that participants integrated the potential action of their co-actor in their own action planning. Compared to the single-actor task, increased parietal and precentral activity during complementary tasks as shown in the fMRI data further suggested representation of the co-actor's response. The superior frontal gyrus of the medial prefrontal cortex was differentially activated in the human co-actor condition compared to the computer co-actor condition. The medial prefrontal cortex, involved thinking about the beliefs and intentions of other people, possibly reflects a social-cognitive aspect or self-other discrimination during the joint task when believing a biological co-actor is present. Our results suggest that action co-representation can occur even offline with any agent type given a priori information that they are co-acting; however, additional regions are recruited when participants believe they are task-sharing with another human.

  8. Neuroimaging of the joint Simon effect with believed biological and non-biological co-actors

    Science.gov (United States)

    Wen, Tanya; Hsieh, Shulan

    2015-01-01

    Performing a task alone or together with another agent can produce different outcomes. The current study used event-related functional magnetic resonance imaging (fMRI) to investigate the neural underpinnings when participants performed a Go/Nogo task alone or complementarily with another co-actor (unseen), whom was believed to be another human or a computer. During both complementary tasks, reaction time data suggested that participants integrated the potential action of their co-actor in their own action planning. Compared to the single-actor task, increased parietal and precentral activity during complementary tasks as shown in the fMRI data further suggested representation of the co-actor’s response. The superior frontal gyrus of the medial prefrontal cortex was differentially activated in the human co-actor condition compared to the computer co-actor condition. The medial prefrontal cortex, involved thinking about the beliefs and intentions of other people, possibly reflects a social-cognitive aspect or self-other discrimination during the joint task when believing a biological co-actor is present. Our results suggest that action co-representation can occur even offline with any agent type given a priori information that they are co-acting; however, additional regions are recruited when participants believe they are task-sharing with another human. PMID:26388760

  9. Radioprotection, biological effects of the radiations and security in the handling of radioactive material

    CERN Document Server

    Teran, M

    2000-01-01

    The development of the philosophy of the radioprotection is dependent on the understanding of the effects of the radiation in the man. Behind the fact that the radiation is able to produce biological damages there are certain factors with regard to the biological effects of the radiations that determine the boarding of the radioprotection topics.

  10. Biological effects from discharge of cooling water from thermal power plants

    International Nuclear Information System (INIS)

    1976-12-01

    Results are reported for a Danish project on biological effects from discharge of cooling water from thermal power plants. The purpose of the project was to provide an up-to-date knowledge of biological effects of cooling water discharge and of organization and evaluation of recipient investigations in planned and established areas. (BP)

  11. Infusing Bioinformatics and Research-Like Experience into a Molecular Biology Laboratory Course

    Science.gov (United States)

    Nogaj, Luiza A.

    2014-01-01

    A nine-week laboratory project designed for a sophomore level molecular biology course is described. Small groups of students (3-4 per group) choose a tumor suppressor gene (TSG) or an oncogene for this project. Each group researches the role of their TSG/oncogene from primary literature articles and uses bioinformatics engines to find the gene…

  12. Biologic effects of fenbendazole in rats and mice: a review.

    Science.gov (United States)

    Villar, David; Cray, Carolyn; Zaias, Julia; Altman, Norman H

    2007-11-01

    This review summarizes findings from toxicologic, carcinogenic, immunologic, and metabolic studies on fenbendazole (FBZ). Currently, FBZ is used to treat or prevent pinworm outbreaks in laboratory rodents. Because antiparasitic treatments usually are not part of experimental designs, interactions from the medication on the outcomes of ongoing experiments are a concern. At therapeutic levels, FBZ does not alter the total content of cytochromes P450 but does induce certain hepatic cytochrome P450 isoforms, namely 1A1, 1A2, and 2B1. Although expressed constitutively at low or undetectable levels, these isoforms particularly are known for bioactivating a number of procarcinogens. Lifetime studies in rats have shown that FBZ is not a carcinogen but that it may behave as a tumor promoter when given after certain initiators. Unlike in other animal species, FBZ treatment-associated myelosuppression has not been reported to occur in rodents. The few currently available immunologic studies in mice, including an autoimmune model, have not shown effects on selected immune responses. However, data from other animal species suggest that the ability of B and T lymphocytes to proliferate in the secondary immune response may be suppressed during treatment with FBZ.

  13. Experiment of decontamination of radioactive liquid by a biological method; Experience de decontamination de liquides radioactifs far voie biologique

    Energy Technology Data Exchange (ETDEWEB)

    Wormser, G.

    1962-07-01

    The author reports experiments of treatment of radioactive liquid effluents by percolation on a bacterial bed like the one used for the treatment of sewer wastewaters. He also reports results obtained in other countries in terms of reduction of effluent radioactivity for various radioactive ions. The installation is described and results are presented in terms of variation of contamination of an effluent with respect to its recycling on a bacterial bed [French] Dans le monde entier, on se preoccupe des moyens de decontamination pour des liquides radioactifs. Les experiences de l'auteur ont confirme qu'un lit bacterien neuf peut donner de bons resultats: il est a noter que ce procede biologique se montre selectif a l'egard des divers ions radioactifs. (auteur)

  14. Qualities of effective secondary science teachers: Perspectives of university biology students

    Science.gov (United States)

    McCall, Madelon J.

    This research was an attempt to hear the student voice concerning secondary science teacher effectiveness and to share that voice with those who impact the educational process. It was a snapshot of university freshmen biology students' opinions of the qualities of effective secondary science teachers based on their high school science experiences. The purpose of this study was to compile a list of effective secondary science teacher qualities as determined through a purposeful sampling of university second semester biology students and determine the role of the secondary science teacher in promoting interest and achievement in science, as well as the teacher's influence on a students' choice of a science career. The research was a mixed methods design using both quantitative and qualitative data obtained through the use of a 24 question electronic survey. There were 125 participants who provided information concerning their high school science teachers. Respondents provided information concerning the qualities of effective secondary science teachers and influences on the students' present career choice. The quantitative data was used to construct a hierarchy of qualities of effective secondary science teachers, divided into personal, professional, and classroom management qualities. The qualitative data was used to examine individual student responses to questions concerning secondary science teacher effectiveness and student career choice. The results of the research indicated that students highly value teachers who are both passionate about the subject taught and passionate about their students. High school science students prefer teachers who teach science in a way that is both interesting and relevant to the student. It was determined that the greatest influence on a secondary student's career choice came from family members and not from teachers. The secondary teacher's role was to recognize the student's interest in the career and provide encouragement

  15. MSW effect and solar neutrino experiments

    International Nuclear Information System (INIS)

    Rosen, S.P.

    1986-01-01

    We describe the MSW solutions to the 37 Cl solar neutrino experiment, and their implications for the 71 Ga experiment. Measurement of the spectrum of electron-type neutrinos arriving at earth is emphasized. 8 refs., 2 figs., 1 tab

  16. CHEMICAL EFFECTS IN BIOLOGICAL SYSTEMS – DATA DICTIONARY (CEBS-DD): A COMPENDIUM OF TERMS FOR THE CAPTURE AND INTEGRATION OF BIOLOGICAL STUDY DESIGN DESCRIPTION, CONVENTIONAL PHENOTYPES AND ‘OMICS’ DATA

    Science.gov (United States)

    A critical component in the design of the Chemical Effects in Biological Systems (CEBS) Knowledgebase is a strategy to capture toxicogenomics study protocols and the toxicity endpoint data (clinical pathology and histopathology). A Study is generally an experiment carried out du...

  17. Sediment contaminants and biological effects in southern California: Use of a multivariate statistical approach to assess biological impact

    International Nuclear Information System (INIS)

    Maxon, C.L.; Barnett, A.M.; Diener, D.R.

    1997-01-01

    This study attempts to predict biological toxicity and benthic community impact in sediments collected from two southern California sites. Contaminant concentrations and grain size were evaluated as predictors using a two-step multivariate approach. The first step used principal component analysis (PCA) to describe contamination type and magnitude present at each site. Four dominant PC vectors, explaining 88% of the total variance, each corresponded to a unique physical and/or chemical signature. The four PC vectors, in decreasing order of importance, were: (1) high molecular weight polynuclear aromatic hydrocarbons (PAH), most likely from combusted or weathered petroleum; (2) low molecular weight alkylated PAH, primarily from weathered fuel product; (3) low molecular weight nonalkylated PAH, indicating a fresh petroleum-related origin; and (4) fine-grained sediments and metals. The second step used stepwise regression analysis to predict individual biological effects (dependent) variables using the four PC vectors as independent variables. Results showed that sediment grain size alone was the best predictor of amphipod mortality. Contaminant vectors showed discrete depositional areas independent of grain size. Neither contaminant concentrations nor PCA vectors were good predictors of biological effects, most likely due to the low concentrations in sediments

  18. Biological actions and effects of low-frequency fields

    International Nuclear Information System (INIS)

    Brix, J.

    1993-01-01

    Cell culture studies have shown that low-frequency electromagnetic fields may affect cell behaviour. The fact that the corresponding field strengths are too weak to affect membrane potential, suggests that these fields trigger enzymatic reactions at the outer face of the membrane, i.e. cell-intrinsic reaction cascades and a biological modification of the affected biological system take place. These are working models and hypotheses which need to substantiated by further studies in this field. Epidemiological studies suggest that electromagnetic fields influence cancer development in man. However there is no action model indicating exposure to fields to be a genotoxic agent possible triggering a direct genetic modification which precludesr any initialization. (orig.) [de

  19. Biological effects of exposure to low frequency electric and magnetic fields

    International Nuclear Information System (INIS)

    Ahnstroem, G.

    1992-10-01

    The biological effects of exposure to low frequency electric and magnetic fields are reviewed with the objective of summarizing effects directly relevant to considerations of the health and safety of exposed people

  20. Effective assimilation of global precipitation: simulation experiments

    Directory of Open Access Journals (Sweden)

    Guo-Yuan Lien

    2013-07-01

    Full Text Available Past attempts to assimilate precipitation by nudging or variational methods have succeeded in forcing the model precipitation to be close to the observed values. However, the model forecasts tend to lose their additional skill after a few forecast hours. In this study, a local ensemble transform Kalman filter (LETKF is used to effectively assimilate precipitation by allowing ensemble members with better precipitation to receive higher weights in the analysis. In addition, two other changes in the precipitation assimilation process are found to alleviate the problems related to the non-Gaussianity of the precipitation variable: (a transform the precipitation variable into a Gaussian distribution based on its climatological distribution (an approach that could also be used in the assimilation of other non-Gaussian observations and (b only assimilate precipitation at the location where at least some ensemble members have precipitation. Unlike many current approaches, both positive and zero rain observations are assimilated effectively. Observing system simulation experiments (OSSEs are conducted using the Simplified Parametrisations, primitivE-Equation DYnamics (SPEEDY model, a simplified but realistic general circulation model. When uniformly and globally distributed observations of precipitation are assimilated in addition to rawinsonde observations, both the analyses and the medium-range forecasts of all model variables, including precipitation, are significantly improved as compared to only assimilating rawinsonde observations. The effect of precipitation assimilation on the analyses is retained on the medium-range forecasts and is larger in the Southern Hemisphere (SH than that in the Northern Hemisphere (NH because the NH analyses are already made more accurate by the denser rawinsonde stations. These improvements are much reduced when only the moisture field is modified by the precipitation observations. Both the Gaussian transformation and

  1. Biological effects of transuranic elements in the environment: human effects and risk estimates

    International Nuclear Information System (INIS)

    Thompson, R.C.; Wachholz, B.W.

    1980-01-01

    The potential for human effects from environmentally dispersed transuranic elements is briefly reviewed. Inhalation of transuranics suspended in air and ingestion of transuranics deposited on or incorporated in foodstuffs are the significant routes of entry. Inhalation is probably the more important of these routes because gastrointestinal absorption of ingested transuranics is so inefficient. Major uncertainties are those concerned with substantially enhanced absorption by the very young and the possibility of increased availability as transuranics become incorporated in biological food chains

  2. Biological effects of anthropogenic chemical stress: Tools for the assessment of ecosystem health (BEAST)

    DEFF Research Database (Denmark)

    Lehtonen, Kari K.; Sundelin, Brita; Lang, Thomas

    : Tools for the Assessment of Ecosystem Health, 2009-2011), which is part of the Baltic Sea BONUS+ Programme funded jointly by national funding agencies and FP7 ERA-NET+ of the European Commission. The BEAST project consists of three workpackages (WP) with the following main tasks: WP1- Field studies...... and experiments in selected sub-regions of the Baltic Sea, WP2 - Application and validation of methods in monitoring and assessment in the Baltic Sea, and WP3 - Developing tools for ecosystem health assessment in the Baltic Sea. BEAST research activities are focused in the sub-regions of Gulf of Bothnia, Gulf...... of Finland, Gulf of Riga, Gulf of Gdansk and the Belt Sea, most of which are characterised by scarce data on biological effects of hazardous substances. The data acquired will be combined with previous data (e.g. national monitoring activities, case studies, EU BEEP project) to reach the goals of WP2 and WP3...

  3. Peer led team learning in introductory biology: effects on peer leader critical thinking skills.

    Science.gov (United States)

    Snyder, Julia J; Wiles, Jason R

    2015-01-01

    This study evaluated hypothesized effects of the Peer-Led Team Learning (PLTL) instructional model on undergraduate peer leaders' critical thinking skills. This investigation also explored peer leaders' perceptions of their critical thinking skills. A quasi-experimental pre-test/post-test with control group design was used to determine critical thinking gains in PLTL/non-PLTL groups. Critical thinking was assessed using the California Critical Thinking Skills Test (CCTST) among participants who had previously completed and been successful in a mixed-majors introductory biology course at a large, private research university in the American Northeast. Qualitative data from open-ended questionnaires confirmed that factors thought to improve critical thinking skills such as interaction with peers, problem solving, and discussion were perceived by participants to have an impact on critical thinking gains. However, no significant quantitative differences in peer leaders' critical thinking skills were found between pre- and post-experience CCTST measurements or between experimental and control groups.

  4. Spectral and spatial shaping of a laser-produced ion beam for radiation-biology experiments

    Directory of Open Access Journals (Sweden)

    L. Pommarel

    2017-03-01

    Full Text Available The study of radiation biology on laser-based accelerators is most interesting due to the unique irradiation conditions they can produce, in terms of peak current and duration of the irradiation. In this paper we present the implementation of a beam transport system to transport and shape the proton beam generated by laser-target interaction for in vitro irradiation of biological samples. A set of four permanent magnet quadrupoles is used to transport and focus the beam, efficiently shaping the spectrum and providing a large and relatively uniform irradiation surface. Real time, absolutely calibrated, dosimetry is installed on the beam line, to enable shot-to-shot control of dose deposition in the irradiated volume. Preliminary results of cell sample irradiation are presented to validate the robustness of the full system.

  5. Biologically mediated dissolution of volcanic glass in seawater

    NARCIS (Netherlands)

    Staudigel, H; Yayanos, A; Chastain, R; Davies, G.T.; Verdurmen, E.A Th; Schiffmann, P; Bourcier, R; de Baar, H.J.W.

    1998-01-01

    We studied the effects of biological mediation on the dissolution of basaltic glass in seawater. Experiments with typical seawater microbial populations were contrasted with a sterile control, and reactions were monitored chemically and isotopically. Biologically mediated experiments produce twice

  6. Exposures at low doses and biological effects of ionizing radiations

    International Nuclear Information System (INIS)

    Masse, R.

    2000-01-01

    Everyone is exposed to radiation from natural, man-made and medical sources, and world-wide average annual exposure can be set at about 3.5 mSv. Exposure to natural sources is characterised by very large fluctuations, not excluding a range covering two orders of magnitude. Millions of inhabitants are continuously exposed to external doses as high as 10 mSv per year, delivered at low dose rates, very few workers are exposed above the legal limit of 50 mSv/year, and referring to accidental exposures, only 5% of the 116 000 people evacuated following the Chernobyl disaster encountered doses above 100 mSv. Epidemiological survey of accidentally, occupationally or medically exposed groups have revealed radio-induced cancers, mostly following high dose-rate exposure levels, only above 100 mSv. Risk coefficients were derived from these studies and projected into linear models of risk (linear non-threshold hypothesis: LNT), for the purpose of risk management following exposures at low doses and low dose-rates. The legitimacy of this approach has been questioned, by the Academy of sciences and the Academy of medicine in France, arguing: that LNT was not supported by Hiroshima and Nagasaki studies when neutron dose was revisited; that linear modelling failed to explain why so many site-related cancers were obviously nonlinearly related to the dose, and especially when theory predicted they ought to be; that no evidence could be found of radio-induced cancers related to natural exposures or to low exposures at the work place; and that no evidence of genetic disease could be shown from any of the exposed groups. Arguments were provided from cellular and molecular biology helping to solve this issue, all resulting in dismissing the LNT hypothesis. These arguments included: different mechanisms of DNA repair at high and low dose rate; influence of inducible stress responses modifying mutagenesis and lethality; bystander effects allowing it to be considered that individual

  7. Fast neutron biological effects on normal and tumor chromatin

    International Nuclear Information System (INIS)

    Constantinescu, B.; Bugoi, Roxana; Paunica, Tatiana; Radu, Liliana

    1997-01-01

    Growing interest in neutron therapy and radioprotection requires complex studies on the mechanisms of neutron action on biological systems, especially on chromatin (the complex of deoxyribonucleic acid-DNA- with proteins in eukaryotic cells). Our study aims to investigate the fast neutrons induced damages in normal and tumor chromatin, studying thermal transition, intrinsic fluorescence and fluorescence of chromatin-ethidium bromide complexes behavior versus irradiation dose. The Bucharest U-120 variable energy Cyclotron was employed as an intense source of fast neutrons produced by 13.5 MeV deuterons on a thick beryllium target (166.5 mg/cm 2 ) placed at 20 angle against the incident beam. The average energy is 5.24 MeV. The total yield at 0 angle is 6.7 x 10 16 n/sr·C·MeV. To determine neutron and gamma irradiation doses, home made thermoluminescent detectors-TLD(γ) and TLD (γ + n) were used: for gamma MgF 2 : Mn mixed with Teflon pellets (φ 12.5 mm, 0.6±0.1 mm thick) and for gamma plus neutrons MgF 2 :Mn mixed with 6 LiF and Teflon pellets (same dimensions). Using a 8.022 x 10 -2 albedo factor value and the equivalence 1Gy (n)=2·10 10 fast neutron/cm 2 , the dose for the irradiation of 1.2 x 10 2 Gy/μC, with an estimated precision of 15% C for neutrons and 7.8 x 10 -4 Gy/μC for gamma, at 10 cm behind Be target, was found, respectively. A diminution of the negative fluorescence intensity for chromatin-ethidium bromide complexes with the increasing of neutron dose (from 0.98 at 5 Gy to 0.85 at 100 Gy) was observed for normal chromatin. This fact reflects chromatin DNA injuries, with the decrease of double helix DNA proportion. To study the influence of gyrostan, thyroxine and D3 vitamin treatments on fast neutron radiolysis in tumor chromatin,10 mg/kg of anticancer drug gyrostan, 40μg/kg of hormonal compound thyroxine and 30,000 IU/kg of D3 vitamin were administrated, separately or associated, to Wistar rats bearing Walker carcinosarcoma. Representing

  8. Effect of biological sprays on the incidence of grey mould, fruit yield and fruit quality in organic strawberry production

    Directory of Open Access Journals (Sweden)

    S. PROKKOLA

    2008-12-01

    Full Text Available Plant diseases, especially grey mould (Botrytis cinerea, may cause severe losses in organic strawberry production. In a two-year period, 2001–2002, the effects of different biological sprays on grey mould, the fruit yield and fruit quality of organically grown strawberry ‘Jonsok’ were studied in field trials at MTT Agrifood Research Finland in Ruukki and Mikkeli. In Experiment 1 the biological sprays were seaweed, garlic and compost extracts, silicon and Trichoderma spp. on both trial sites. In Experiment 2, compost extract, Trichoderma spp. and Gliocladium catenulatum sprays were studied in Ruukki. The treatment time was chosen to control grey mould. The effect of different biological sprays on the incidence of grey mould and total and marketable yield was insignificant compared to the untreated control. In both years and in all trials the incidence of grey mould was low and rot occurred mainly in the latter part of the harvesting period, which may partly explain the small differences between treatments. Anyhow, despite of feasible biological control cultural control methods will be important to manage the fungus in organic strawberry production.;

  9. Biological effects of petroleum hydrocarbons: Predictions of long-term effects and recovery

    International Nuclear Information System (INIS)

    Capuzzo, J.M.

    1990-01-01

    Biological effects of petroleum hydrocarbons on marine organisms and ecosystems are dependent on the persistence and bioavailability of specific hydrocarbons, the ability of organisms to accumulate and metabolize various hydrocarbons, the fate of metabolized products, and the interference of specific hydrocarbons with normal metabolic processes that may alter an organism's chances for survival and reproduction in the environment. In considering the long-term effects of petroleum hydrocarbons on marine ecosystems it is important to ascertain what biological effects may result in subtle ecological changes, changes in community structure and function, and possible impairment of fisheries resources. It is also important to understand which hydrocarbons persist in benthic environments and the sublethal effects that lead to reduced growth, delayed development and reduced reproductive effort, population decline and the loss of that population's function in marine communities. Only through a multi-disciplinary approach to the study of the fate, transport and effects of petroleum hydrocarbons on marine ecosystems will there be a significant improvement in the ability to predict the long-term effects of oil spills and to elucidate the mechanisms of recovery

  10. Behavior of oxyfluorfen in soils amended with different sources of organic matter. Effects on soil biology.

    Science.gov (United States)

    Gómez, Isidoro; Rodríguez-Morgado, Bruno; Parrado, Juan; García, Carlos; Hernández, Teresa; Tejada, Manuel

    2014-05-30

    We performed a laboratory study on the effect of oxyfluorfen at a rate of 4lha(-1) on biological properties of a soil amended with four organic wastes (two biostimulants/biofertilizers, obtained from rice bran, RB1 and RB2; municipal solid waste, MSW; and sheep manure, SM). Soil was mixed with SM at a rate of 1%, MSW at a rate of 0.52%, RB1 at a rate of 0.39% and RB2 at a rate of 0.30%, in order to apply the same amount of organic matter to the soil. The enzymatic activities and microbial community in the soil were determined during the incubation times. The application of RB1 and RB2 to soil without oxyfluorfen increased the enzymatic activities and biodiversity, peaking at day 10 of the incubation period. This stimulation was higher in the soil amended with RB2 than in that amended with RB1. In SM and CF-amended soils, the stimulation of enzymatic activities and soil biodiversity increased during the experiment. The application of herbicide in organic-amended soils decreased the inhibition of soil enzymatic activities and soil biodiversity. Possibly the low molecular weight protein content easily assimilated by soil microorganisms and the higher fat content in the biostimulants/biofertilizers are responsible for the lower inhibition of these soil biological properties. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Integrated Network Analysis and Effective Tools in Plant Systems Biology

    Directory of Open Access Journals (Sweden)

    Atsushi eFukushima

    2014-11-01

    Full Text Available One of the ultimate goals in plant systems biology is to elucidate the genotype-phenotype relationship in plant cellular systems. Integrated network analysis that combines omics data with mathematical models has received particular attention. Here we focus on the latest cutting-edge computational advances that facilitate their combination. We highlight (1 network visualization tools, (2 pathway analyses, (3 genome-scale metabolic reconstruction, and (4 the integration of high-throughput experimental data and mathematical models. Multi-omics data that contain the genome, transcriptome, proteome, and metabolome and mathematical models are expected to integrate and expand our knowledge of complex plant metabolisms.

  12. Data warehousing in molecular biology.

    Science.gov (United States)

    Schönbach, C; Kowalski-Saunders, P; Brusic, V

    2000-05-01

    In the business and healthcare sectors data warehousing has provided effective solutions for information usage and knowledge discovery from databases. However, data warehousing applications in the biological research and development (R&D) sector are lagging far behind. The fuzziness and complexity of biological data represent a major challenge in data warehousing for molecular biology. By combining experiences in other domains with our findings from building a model database, we have defined the requirements for data warehousing in molecular biology.

  13. Participation, representation, and shared experiences of women scholars in biological anthropology.

    Science.gov (United States)

    Turner, Trudy R; Bernstein, Robin M; Taylor, Andrea B; Asangba, Abigail; Bekelman, Traci; Cramer, Jennifer Danzy; Elton, Sarah; Harvati, Katarina; Williams-Hatala, Erin Marie; Kauffman, Laurie; Middleton, Emily; Richtsmeier, Joan; Szathmáry, Emőke; Torres-Rouff, Christina; Thayer, Zaneta; Villaseñor, Amelia; Vogel, Erin

    2018-01-01

    American Association of Physical Anthropologists (AAPA) membership surveys from 1996 and 1998 revealed significant gender disparities in academic status. A 2014 follow-up survey showed that gender equality had improved, particularly with respect to the number of women in tenure-stream positions. However, although women comprised 70% of AAPA membership at that time, the percentage of women full professors remained low. Here, we continue to consider the status of women in biological anthropology by examining the representation of women through a quantitative analysis of their participation in annual meetings of the AAPA during the past 20 years. We also review the programmatic goals of the AAPA Committee on Diversity Women's Initiative (COD-WIN) and provide survey results of women who participated in COD-WIN professional development workshops. Finally, we examine the diversity of women's career paths through the personal narratives of 14 women biological anthropologists spanning all ranks from graduate student to Professor Emeritus. We find that over the past 20 years, the percentage of women first authors of invited symposia talks has increased, particularly in the sub-disciplines of bioarchaeology, genetics, and paleoanthropology. The percentage of women first authors on contributed talks and posters has also increased. However, these observed increases are still lower than expected given the percentage of graduate student women and women at the rank of assistant and associate professor. The personal narratives highlight first-hand the impact of mentoring on career trajectory, the challenges of achieving work-life satisfaction, and resilience in the face of the unexpected. We end with some suggestions for how to continue to improve equality and equity for women in biological anthropology. © 2018 American Association of Physical Anthropologists.

  14. The effect of graphic organizers on students' attitudes and academic performance in undergraduate general biology

    Science.gov (United States)

    Cleveland, Lacy

    High attrition among undergraduate Science Technology Engineering and Mathematics (STEM) majors has led national and business leaders in the United States to call for both research and educational reform within the collegiate STEM classrooms. Included among suggestions for reform are ideas to improve retention of first-year students and to improve critical thinking and depth of knowledge, instead of covering large quantities of materials. Past research on graphic organizers suggest these tools assist students in learning information and facilitate conceptual and critical thinking. Despite their widespread use in high school science departments, collegiate humanities departments, and even medical schools, their use is considerably less prevalent in the undergraduate biology classroom. In addition to their lack of use, little research has been conducted on their academic benefits in the collegiate classroom. Based on national calls for improving retention among undergraduate STEM majors and research suggesting that academic success during an individual first major's related course highly determine if that individual will continue on in their intended major, the researcher of this dissertation chose to conduct research on an introductory general biology class. Using both quantitative and qualitative methods, the research in this dissertation examines the effectiveness of graphic organizers in promoting academic success and also examines their influence on student attitudes. This research is grounded in the theories of constructivism and cognitive load theory. Constructivism suggests that individuals must build their knowledge from their personal experiences, while the cognitive load theory recognizes the limited nature of one's working memory and suggests that instructional practices minimize cognitive overload. The results of this dissertation suggest that the use of graphic organizers in an undergraduate general biology classroom can increase students' academic

  15. Patients' experiences towards the donation of their residual biological samples and the impact of these experiences on the type of consent given for secondary use: A systematic review.

    Science.gov (United States)

    Wai, Chan Tuck; Mackey, Sandra Jane; Hegney, Desley Gail

    safeguards and controls in order to maintain privacy and confidentiality of the patients; (3) Healthcare professionals should be aware that the views on ownership and rights to the tissues will vary between individual patients; (4) Healthcare professionals, institutions and regulatory authorities should be aware that patients have different views on the commercial use of their tissues.Discussion Patients would prefer that institutions requesting donation of leftover tissues establish a good governance system for the collection and storage of tissues, as well as a system for protecting the rights and confidentiality of patients. Most patients prefer to have an ethical and effective system, which decides the future use of their tissues, especially when a full informed consent is not obtained from the patients at time of donation and subsequent use.Implications for Practice The results from this review can assist researchers and policy makers to understand the experiences of patients and their attitudes and preferences on the collection, storage, distribution and use of their leftover tissue for research. This is especially so when designing a prospective model of consent regimen, to respect patients' needs and make recommendations for the use of existing and previously collected biological samples with no consent taken.Implications for Research Further qualitative research can be undertaken to ascertain patients' expectations when they donate their tissues; the type of consent model to be used; the perceived risks of genetic and stem cells research; and the effects of culture, religion and age on patients' willingness to donate their leftover tissues for future research.

  16. Variability of Biological Degradation of Phenolic Hydrocarbons in an Aerobic Aquifer Determined by Laboratory Batch Experiments

    DEFF Research Database (Denmark)

    Nielsen, Per Henning; Christensen, Thomas Højlund

    1994-01-01

    The biological aerobic degradation of 7 phenolic hydrocarbons (phenol, o-cresol, o-nitrophenol, p-nitrophenol, 2,6-dichlorophenol, 2,4-dichlorophenol, 4,6-o-dichlorocresol) and 1 aromatic hydrocarbon (nitrobenzene) was studied for 149 days in replicate laboratory batch microcosms with sediment...... and groundwater from 8 localities representing a 15 m × 30 m section of an aerobic aquifer. Three patterns of variation were found: (1) phenol, o-cresol and in most cases p-nitrophenol showed very fast degradation with no or only short lag phases and with very little variation among localities; (2) 2...

  17. Multiple daily fractionation in radiotherapy: biological rationale and preliminary clinical experiences

    Energy Technology Data Exchange (ETDEWEB)

    Arcangeli, G [Instituto Medico Scientifico, Rome (Italy). Dept. of Oncology; Mauro, F; Morelli, D; Nervi, C

    1979-09-01

    The biological bases of radiation dose fractionation are reviewed and discussed with special emphasis on reassortment. Experimental data on animal model systems are presented to clarify that reassortment has to be added to sublethal damage repair and reoxygenation in the rationale for an optimized radiotherapy course according to tumor cell kinetics. Clinical results on several human tumors treated with twice or thrice daily fractions are described. These results show that some clinically radioresistant tumors (especially if not characterized by a relatively long clinical doubling line) can be satisfactorily dealt with using multiple daily fractionation. Clinical observations indicate that a relatively high cumulative daily dose (200 + 150 + 150 rad) can be safely administered.

  18. Adverse effects of biologics: a network meta-analysis and Cochrane overview

    DEFF Research Database (Denmark)

    Singh, J. A.; Wells, G. A.; Christensen, Robin Daniel Kjersgaard

    2011-01-01

    Background Biologics are used for the treatment of rheumatoid arthritis and many other conditions. While the efficacy of biologics has been established, there is uncertainty regarding the adverse effects of this treatment. Since serious risks such as tuberculosis (TB) reactivation, serious...

  19. Gender Inequality in Biology Classes in China and Its Effects on Students' Short-Term Outcomes

    Science.gov (United States)

    Liu, Ning; Neuhaus, Birgit

    2014-01-01

    This study investigated gender inequality in biology lessons and analysed the effects of the observed inequality on students' short-term knowledge achievement, situational interest and students' evaluation of teaching (SET). Twenty-two biology teachers and 803 7th-grade students from rural and urban classrooms in China participated in the study.…

  20. The Effects of 3D Computer Simulation on Biology Students' Achievement and Memory Retention

    Science.gov (United States)

    Elangovan, Tavasuria; Ismail, Zurida

    2014-01-01

    A quasi experimental study was conducted for six weeks to determine the effectiveness of two different 3D computer simulation based teaching methods, that is, realistic simulation and non-realistic simulation on Form Four Biology students' achievement and memory retention in Perak, Malaysia. A sample of 136 Form Four Biology students in Perak,…

  1. Floral biology and the effects of plant-pollinator interaction on ...

    African Journals Online (AJOL)

    Reproductive biology and patterns of plant-pollinator interaction are fundamental to gene flow, diversity and evolutionary success of plants. Consequently, we examined the magnitude of insect-plant interaction based on the dynamics of breeding systems and floral biology and their effects on pollination intensity, fruit and ...

  2. Biological effects of radiation in combination with other physical, chemical or biological agents. Annex L

    International Nuclear Information System (INIS)

    1982-01-01

    This Annex considers the combined action of radiation with potentially important environmental conditions. Since there is a scarcity of systematic data on which an analysis of combined effects can be based, this Annex will be more hypothetical and will attempt to suggest definitions, to identify suitable methods of analysis, to select from a large amount of diffuse information the conditions and the data of importance for further consideration and to provide suggestions for future research. For humans in environmental circumstances the UNSCEAR Committee has been unable to document any clear case of synergistic interaction between radiation and other agents, which could lead to substantial modifications of the risk estimates for significant sections of the population.

  3. Biological function evaluation and effects of laser micro-pore burn-denatured acellular dermal matrix.

    Science.gov (United States)

    Zhang, Youlai; Zeng, Yuanlin; Xin, Guohua; Zou, Lijin; Ding, Yuewei; Duyin, Jiang

    2018-03-01

    In the field of burns repairs, many problems exist in the shortage of donor skin, the expense of allograft or xenograft skin, temporary substitution and unsatisfactory extremity function after wound healing. Previous studies showed that burn-denatured skin could return to normal dermis formation and function. This study investigates the application of laser micro-pore burn-denatured acellular dermis matrix (DADM) from an escharotomy in the repair of burn wounds and evaluates the biological properties and wound repair effects of DADM in implantation experiments in Kunming mice. Specific-pathogen-free (SPF) Kunming mice were used in this study. A deep II° burn wound was created on the dorsum of the mice by an electric heated water bath. The full-thickness wound tissue was harvested. The necrotic tissue and subcutaneous tissue were removed. The denatured dermis was preserved and treated with 0.25% trypsin, 0.5% Triton X-100. The DADM was drilled by laser micro-pore. The biological properties and grafting effects of laser micro-pore burn-DADM were evaluated by morphology, cytokine expression levels and subcutaneous implantation experiments in Kunming mice. We found statistical significance (Ppore burn-DADM (experimental group) compared to the control group (no laser micro-pore burn-DADM). Cytokine expression level was different in the dermal matrixes harvested at various time points after burn (24h, 48h, 72h and infected wound group). Comparing the dermal matrix from 24h burn tissue to infected wound tissue, the expression level of IL-6, MMP-24, VE-cadherin and VEGF were decreased. We found no inflammatory cells infiltration in the dermal matrix were observed in both experimental and control groups (24h burn group), while the obviously vascular infiltration and fiber fusion were observed in the experimental group after subcutaneous implantation experiments. There was better bio-performance, low immunogenicity and better dermal incorporation after treated by laser

  4. A Case-Based Scenario with Interdisciplinary Guided-Inquiry in Chemistry and Biology: Experiences of First Year Forensic Science Students

    Science.gov (United States)

    Cresswell, Sarah L.; Loughlin, Wendy A.

    2017-01-01

    In this paper, insight into forensic science students' experiences of a case-based scenario with an interdisciplinary guided-inquiry experience in chemistry and biology is presented. Evaluation of student experiences and interest showed that the students were engaged with all aspects of the case-based scenario, including the curriculum theory…

  5. Effect of biological factors during functional scintigraphy of the heart

    Energy Technology Data Exchange (ETDEWEB)

    Breuel, H P; Emrich, D; Luig, H [Goettingen Univ. (F.R. Germany). Abt. fuer Nuklearmedizin

    1976-07-01

    The parameters relating to functional scintigraphy of the heart (average circulation time, peak time) depend not only on the method (injection technique, radiopharmaceutical), but also on biological factors. Failure to take these into consideration may result in an erroneous interpretation of the findings. Circulation time in normal children aged 6 to 14 years, as determined by isotope methods is significantly shorter than in normal adults. Patients with compensated heart disease, as well trained athletes, show significant increase in all portions of the circulation time, when compared with normals of similar ages. This indicates that deviation in the haemodynamics of the circulation as shown by functional scintigraphy, can only be interpreted in the light of clinical findings.

  6. Biological methanogenesis and the CO2 greenhouse effect

    Science.gov (United States)

    Guthrie, P. D.

    1986-01-01

    It is well established that plants tend to increase net photosynthesis under increased carbon dioxide. It is also well established that a large fraction of atmospheric methane is produced by microbial metabolism of organic sediments in paddies and freshwater wetlands, where a major source of organic debris is local plant growth. As CO2 increases, it may lead to increased methane production and a resulting enhancement of the expected greenhouse warming. A rough estimate of the present rate of this biologically mediated feedback on the climate system indicates that it might account for as much as 30 percent of the observed methane increase and speed up the greenhouse forcing by as much as 15 percent.

  7. Biological effects induced by K photoionization in the DNA atoms

    International Nuclear Information System (INIS)

    Gobert, F.; Herve, M.A.; Penhoat, H. du; Touati, A.; Abel, F.; Lamoureux, M.; Politis, M.F.; Sabatier, L.; Chetioui, A.

    2001-01-01

    An experiment has been made at the Lure using ultra soft X radiations (340 eV) to check the hypothesis that the K ionizations of DNA atoms could be the critical events at the origin of ionizing radiations lethality and then despite of a low probability. (N.C.)

  8. Antiprotons get biological

    CERN Multimedia

    2003-01-01

    After its final run in September, the first results of the Antiproton Cell Experiment (ACE) look very promising. It was the first experiment to take data on the biological effects of antiproton beams to evaluate the potential of antiprotons in radiation therapy.

  9. Meta-analysis reveals complex marine biological responses to the interactive effects of ocean acidification and warming

    Science.gov (United States)

    Harvey, Ben P; Gwynn-Jones, Dylan; Moore, Pippa J

    2013-01-01

    Ocean acidification and warming are considered two of the greatest threats to marine biodiversity, yet the combined effect of these stressors on marine organisms remains largely unclear. Using a meta-analytical approach, we assessed the biological responses of marine organisms to the effects of ocean acidification and warming in isolation and combination. As expected biological responses varied across taxonomic groups, life-history stages, and trophic levels, but importantly, combining stressors generally exhibited a stronger biological (either positive or negative) effect. Using a subset of orthogonal studies, we show that four of five of the biological responses measured (calcification, photosynthesis, reproduction, and survival, but not growth) interacted synergistically when warming and acidification were combined. The observed synergisms between interacting stressors suggest that care must be made in making inferences from single-stressor studies. Our findings clearly have implications for the development of adaptive management strategies particularly given that the frequency of stressors interacting in marine systems will be likely to intensify in the future. There is now an urgent need to move toward more robust, holistic, and ecologically realistic climate change experiments that incorporate interactions. Without them accurate predictions about the likely deleterious impacts to marine biodiversity and ecosystem functioning over the next century will not be possible. PMID:23610641

  10. Discrimination of Semi-Quantitative Models by Experiment Selection: Method Application in Population Biology

    NARCIS (Netherlands)

    Vatcheva, Ivayla; Bernard, Olivier; de Jong, Hidde; Gouze, Jean-Luc; Mars, Nicolaas; Nebel, B.

    2001-01-01

    Modeling an experimental system often results in a number of alternative models that are justified equally well by the experimental data. In order to discriminate between these models, additional experiments are needed. We present a method for the discrimination of models in the form of

  11. Does Teaching Experience Matter? Examining Biology Teachers' Prior Knowledge for Teaching in an Alternative Certification Program

    Science.gov (United States)

    Friedrichsen, Patricia J.; Abell, Sandra K.; Pareja, Enrique M.; Brown, Patrick L.; Lankford, Deanna M.; Volkmann, Mark J.

    2009-01-01

    Alternative certification programs (ACPs) have been proposed as a viable way to address teacher shortages, yet we know little about how teacher knowledge develops within such programs. The purpose of this study was to investigate prior knowledge for teaching among students entering an ACP, comparing individuals with teaching experience to those…

  12. Effect of biological activated carbon pre-treatment to control organic fouling in the microfiltration of biologically treated secondary effluent.

    Science.gov (United States)

    Pramanik, Biplob Kumar; Roddick, Felicity A; Fan, Linhua

    2014-10-15

    Biological activated carbon (BAC) filtration was investigated as a pre-treatment for reducing the organic fouling of a microfiltration membrane (0.1 μm polyvinylidene fluoride) in the treatment of a biologically treated secondary effluent (BTSE) from a municipal wastewater treatment plant. BAC treatment of the BTSE resulted in a marked improvement in permeate flux, which was attributed to the effective removal of organic foulants and particulates. Although the BAC removed significantly less dissolved organic carbon than the granular activated carbon (GAC) treatment which was used as a control for comparison, it led to a markedly greater flux. This was attributed to the effective removal of the very high molecular weight substances such as biopolymers by the BAC through biodegradation and adsorption of those molecules on the biofilm. Size exclusion chromatography showed the BAC treatment led to approximately 30% reduction in these substances, whereas the GAC did not greatly remove these molecules. The BAC treatment led to a greater reduction of loosely-attached and firmly-attached membrane surface foulant, and this was confirmed by attenuated total reflection-fourier transform infrared spectroscopy analysis. This study demonstrated the potential of BAC pre-treatment for reducing organic fouling and thus improving flux for the microfiltration of BTSE. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Practice as source of learning and knowledge that comes from experience: what science and biology teachers say about it

    Directory of Open Access Journals (Sweden)

    Luciana M. Lunardi Campos

    2001-01-01

    Full Text Available This paper is about the possible knowledge that Science and Biology teachers may acquire form their daily work. Fourth three teachers were considered in this research and all belong to the Public School of the city of Botucatu, S.P. All of them were unanimous in stressing the importance of their professional activity as a meaningful aspect. They learned more about themselves, their methods, their employed resources and their pupils through it. Three dimensions can be pointed out here: personal, professional and pedagogical and it can be named nine aspects of the knowledge from experience. An organized and active knowledge may be achieved by reckoning the teacher as the main producer of knowledge about his occupation and assuming as well how important his practice and knowledge from experience are.

  14. Investigating the Effect of Biological Crusts on Some Biological Properties of Soil (Case Study: Qare Qir Rangelands of Golestan Province

    Directory of Open Access Journals (Sweden)

    J. Kakeh

    2016-09-01

    Full Text Available Introduction: Physical and biological soil crusts are the principal types of soil crusts. Physical and biological soil crusts are distributed in arid, semi-arid and sub-humid regions which constitute over 40% of the earth terrestrial surface. Biological soil crusts (BSCs result from an intimate association between soil particles and cyanobacteria, algae, fungi, lichens and mosses in different proportions which live on the surface, or in the immediately uppermost millimeters of soil. Some of the functions that BSCs influences include: water absorption and retention, nutrient retention, Carbon and nitrogen fixation, biological activate and hydrologic Status. BSCs are important from the ecological view point and their effects on the environment, especially in rangeland, and desert ecosystems and this caused which researchers have a special attention to this component of the ecosystems more than before. Materials and Methods: This study carried out in the Qara Qir rangelands of Golestan province, northeast of Iran (37º15′ - 37º23′ N &54º33′ -54º39′ E, to investigate the effects of BSCs on some of soil biological properties. Four sites including with and without BSCs cover were selected. Soil biological properties such as microbial populations, soil respiration, microbial biomass carbon and nitrogen, as well as, other effective properties such asorganic carbon percent, total nitrogen, electrical conductivity, and available water content were measured in depths of 0-5 and 5-15 cm of soil with four replications. The gathered data were analyzed by nested plot, and the mean values were compared by Duncan test. Results and Discussion: The results showed that organic carbon and water content were higher at the surface under BSCs, followed by 5-15 cm soils under BSCs. Both soil depths of uncrusted soils showed substantially lower organic carbon and water content than the BSC-covered soils. Total nitrogen was far higher in BSC-encrusted surface

  15. Undergraduate Biology Lab Courses: Comparing the Impact of Traditionally Based "Cookbook" and Authentic Research-Based Courses on Student Lab Experiences

    Science.gov (United States)

    Brownell, Sara E.; Kloser, Matthew J.; Fukami, Tadishi; Shavelson, Rich

    2012-01-01

    Over the past decade, several reports have recommended a shift in undergraduate biology laboratory courses from traditionally structured, often described as "cookbook," to authentic research-based experiences. This study compares a cookbook-type laboratory course to a research-based undergraduate biology laboratory course at a Research 1…

  16. Disappearance of the inversion effect during memory-guided tracking of scrambled biological motion.

    Science.gov (United States)

    Jiang, Changhao; Yue, Guang H; Chen, Tingting; Ding, Jinhong

    2016-08-01

    The human visual system is highly sensitive to biological motion. Even when a point-light walker is temporarily occluded from view by other objects, our eyes are still able to maintain tracking continuity. To investigate how the visual system establishes a correspondence between the biological-motion stimuli visible before and after the disruption, we used the occlusion paradigm with biological-motion stimuli that were intact or scrambled. The results showed that during visually guided tracking, both the observers' predicted times and predictive smooth pursuit were more accurate for upright biological motion (intact and scrambled) than for inverted biological motion. During memory-guided tracking, however, the processing advantage for upright as compared with inverted biological motion was not found in the scrambled condition, but in the intact condition only. This suggests that spatial location information alone is not sufficient to build and maintain the representational continuity of the biological motion across the occlusion, and that the object identity may act as an important information source in visual tracking. The inversion effect disappeared when the scrambled biological motion was occluded, which indicates that when biological motion is temporarily occluded and there is a complete absence of visual feedback signals, an oculomotor prediction is executed to maintain the tracking continuity, which is established not only by updating the target's spatial location, but also by the retrieval of identity information stored in long-term memory.

  17. An integrated strategy for biological effects monitoring in Scottish coastal waters

    International Nuclear Information System (INIS)

    Park, R.A.; Dobson, J.; Richardson, L.; Hill, A.

    1999-01-01

    The paper summarises SEPA's current programme of water quality and biological effects monitoring and, using recent examples, discusses the current environmental issues affecting the condition of our coastal waters. (author)

  18. Biological effects of low doses of ionising radiation

    International Nuclear Information System (INIS)

    Osmak, M.

    1998-01-01

    A study was performed with the aim to examine whether the progeny of cells that had been repeatedly irradiated with low doses of gamma rays will change their sensitivity to cytotoxic agents. Four mammalian cell lines were used in the experiment. It was found that the progeny of cells irradiated in this way do not change their sensitivity to gamma rays but would change their sensitivity to various cytostatics drugs. (A.K.)

  19. Low dose effects of ionizing radiations in in vitro and in vivo biological systems: a multi-scale approach study

    International Nuclear Information System (INIS)

    Antoccia, A.; Berardinelli, F.; Argazzi, E.; Balata, M.; Bedogni, R.

    2011-01-01

    Long-term biological effects of low-dose radiation are little known nowadays and its carcinogenic risk is estimated on the assumption that risk remains linearly proportional to the radiation dose down to low-dose levels. However in the last 20 years this hypothesis has gradually begun to seem in contrast with a huge collection of experimental evidences, which has shown the presence of plethora of non-linear phenomena (including hypersensitivity and induced radioresistance, adaptive response, and non-targeted phenomena like bystander effect and genomic instability) occurring after low-dose irradiation. These phenomena might imply a non-linear behaviour of cancer risk curves in the low-dose region and question the validity of the Linear No-Threshold (LNT) model currently used for cancer risk assessment through extrapolation from existing high-dose data. Moreover only few information is available regarding the effects induced on cryo preserved cells by multi-year background radiation exposure, which might induce a radiation-damage accumulation, due to the inhibition of cellular repair mechanisms. In this framework, the multi-year Excalibur (Exposure effects at low doses of ionizing radiation in biological culture) experiment, funded by INFN-CNS5, has undertaken a multi-scale approach investigation on the biological effects induced in in vitro and in vivo biological systems, in culture and cryo preserved conditions, as a function of radiation quality (X/γ-rays, protons, He-4 ions of various energies) and dose, with particular emphasis on the low-dose region and non-linear phenomena, in terms of different biological endpoints.

  20. The effect of abstract versus concrete framing on judgments of biological and psychological bases of behavior.

    Science.gov (United States)

    Kim, Nancy S; Johnson, Samuel G B; Ahn, Woo-Kyoung; Knobe, Joshua

    2017-01-01

    Human behavior is frequently described both in abstract, general terms and in concrete, specific terms. We asked whether these two ways of framing equivalent behaviors shift the inferences people make about the biological and psychological bases of those behaviors. In five experiments, we manipulated whether behaviors are presented concretely (i.e. with reference to a specific person, instantiated in the particular context of that person's life) or abstractly (i.e. with reference to a category of people or behaviors across generalized contexts). People judged concretely framed behaviors to be less biologically based and, on some dimensions, more psychologically based than the same behaviors framed in the abstract. These findings held true for both mental disorders (Experiments 1 and 2) and everyday behaviors (Experiments 4 and 5), and yielded downstream consequences for the perceived efficacy of disorder treatments (Experiment 3). Implications for science educators, students of science, and members of the lay public are discussed.

  1. Implementation of a Collaborative Series of Classroom-Based Undergraduate Research Experiences Spanning Chemical Biology, Biochemistry, and Neurobiology

    Science.gov (United States)

    Kowalski, Jennifer R.; Hoops, Geoffrey C.; Johnson, R. Jeremy

    2016-01-01

    Classroom undergraduate research experiences (CUREs) provide students access to the measurable benefits of undergraduate research experiences (UREs). Herein, we describe the implementation and assessment of a novel model for cohesive CUREs focused on central research themes involving faculty research collaboration across departments. Specifically, we implemented three collaborative CUREs spanning chemical biology, biochemistry, and neurobiology that incorporated faculty members’ research interests and revolved around the central theme of visualizing biological processes like Mycobacterium tuberculosis enzyme activity and neural signaling using fluorescent molecules. Each CURE laboratory involved multiple experimental phases and culminated in novel, open-ended, and reiterative student-driven research projects. Course assessments showed CURE participation increased students’ experimental design skills, attitudes and confidence about research, perceived understanding of the scientific process, and interest in science, technology, engineering, and mathematics disciplines. More than 75% of CURE students also engaged in independent scientific research projects, and faculty CURE contributors saw substantial increases in research productivity, including increased undergraduate student involvement and academic outputs. Our collaborative CUREs demonstrate the advantages of multicourse CUREs for achieving increased faculty research productivity and traditional CURE-associated student learning and attitude gains. Our collaborative CURE design represents a novel CURE model for ongoing laboratory reform that benefits both faculty and students. PMID:27810870

  2. Minimal information: an urgent need to assess the functional reliability of recombinant proteins used in biological experiments

    Directory of Open Access Journals (Sweden)

    de Marco Ario

    2008-07-01

    Full Text Available Abstract Structural characterization of proteins used in biological experiments is largely neglected. In most publications, the information available is totally insufficient to judge the functionality of the proteins used and, therefore, the significance of identified protein-protein interactions (was the interaction specific or due to unspecific binding of misfolded protein regions? or reliability of kinetic and thermodynamic data (how much protein was in its native form?. As a consequence, the results of single experiments might not only become questionable, but the whole reliability of systems biology, built on these fundaments, would be weakened. The introduction of Minimal Information concerning purified proteins to add as metadata to the main body of a manuscript would render straightforward the assessment of their functional and structural qualities and, consequently, of results obtained using these proteins. Furthermore, accepted standards for protein annotation would simplify data comparison and exchange. This article has been envisaged as a proposal for aggregating scientists who share the opinion that the scientific community needs a platform for Minimum Information for Protein Functionality Evaluation (MIPFE.

  3. Importance of temperature control for HEFLEX, a biological experiment for Spacelab 1. [plant gravitational physiology study

    Science.gov (United States)

    Chapman, D. K.; Brown, A. H.

    1979-01-01

    The importance of temperature control to HEFLEX, a Spacelab experiment designed to measure kinetic properties of Helianthis nutation in a low-g environment, is discussed. It is argued that the development of the HEFLEX experiment has been severely hampered by the inadequate control of ambient air temperature provided by the spacecraft module design. A worst case calculation shows that delivery of only 69% of the maximum yield of useful data from the HEFLEX system is guaranteed; significant data losses from inadequate temperature control are expected. The magnitude of the expected data losses indicates that the cost reductions associated with imprecise temperature controls may prove to be a false economy in the long term.

  4. Relative biological effectiveness of tritium for induction of myeloid leukemia in CBA/H mice

    International Nuclear Information System (INIS)

    Johnson, J.R.; Myers, D.K.; Jackson, J.S.; Dunford, D.W.; Gragtmans, N.J.; Wyatt, H.M.; Jones, A.R.; Percy, D.H.

    1995-01-01

    To help resolve uncertainties as to the most appropriate weighting factor for tritium β rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of the CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 Gy both for tritiated water and for X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative mouse-days at risk. The calculated RBE values for tritium 13 rays compared to X rays ranged from 1.0 ± 0.5 to 1.3 ± 0.3. A best estimate of the RBE for this experiment was about 1.2 ± 0.3. A w R value of 1 would thus appear to be more appropriate than a W R of 2 for tritium β rays. (author)

  5. Relative biological effectiveness of tritium for induction of myeloid leukemia in CBA/H mice

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J.R. [Battelle Pacific Northwest Labs., Health Protection Branch, Health Div., Richland, WA (United States); Myers, D.K.; Jackson, J.S.; Dunford, D.W.; Gragtmans, N.J.; Wyatt, H.M.; Jones, A.R. [Atomic Energy of Canada Limited, Chalk River, Ontairo (Canada); Percy, D.H. [Univ. of Guelph, Ontario Veterinary College, Guelph, Ontario (Canada)

    1995-07-01

    To help resolve uncertainties as to the most appropriate weighting factor for tritium {beta} rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of the CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 Gy both for tritiated water and for X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative mouse-days at risk. The calculated RBE values for tritium 13 rays compared to X rays ranged from 1.0 {+-} 0.5 to 1.3 {+-} 0.3. A best estimate of the RBE for this experiment was about 1.2 {+-} 0.3. A w{sub R} value of 1 would thus appear to be more appropriate than a W{sub R} of 2 for tritium {beta} rays. (author)

  6. Relative biological effectiveness of tritium for induction of myeloid leukemia in CBA/H mice.

    Science.gov (United States)

    Johnson, J R; Myers, D K; Jackson, J S; Dunford, D W; Gragtmans, N J; Wyatt, H M; Jones, A R; Percy, D H

    1995-10-01

    To help resolve uncertainties as to the most appropriate weighting factor for tritium beta rays, a large experiment was carried out to measure the relative biological effectiveness (RBE) of tritiated water compared to X rays for the induction of myeloid leukemia in male mice of the CBA/H strain. The study was designed to estimate the lifetime incidence of myeloid leukemia in seven groups of about 750 mice each; radiation exposures were approximately 0, 1, 2 and 3 Gy both for tritiated water and for X rays. The lifetime incidence of leukemia in these mice increased from 0.13% in the control group to 6-8% in groups exposed to higher radiation doses. The results were fitted to various equations relating leukemia incidence to radiation dose, using both the raw data and data corrected for cumulative mouse-days at risk. The calculated RBE values for tritium beta rays compared to X rays ranged from 1.0 +/- 0.5 to 1.3 +/- 0.3. A best estimate of the RBE for this experiment was about 1.2 +/- 0.3. A wR value of 1 would thus appear to be more appropriate than a wR of 2 for tritium beta rays.

  7. Implementation of a Collaborative Series of Classroom-Based Undergraduate Research Experiences Spanning Chemical Biology, Biochemistry, and Neurobiology.

    Science.gov (United States)

    Kowalski, Jennifer R; Hoops, Geoffrey C; Johnson, R Jeremy

    2016-01-01

    Classroom undergraduate research experiences (CUREs) provide students access to the measurable benefits of undergraduate research experiences (UREs). Herein, we describe the implementation and assessment of a novel model for cohesive CUREs focused on central research themes involving faculty research collaboration across departments. Specifically, we implemented three collaborative CUREs spanning chemical biology, biochemistry, and neurobiology that incorporated faculty members' research interests and revolved around the central theme of visualizing biological processes like Mycobacterium tuberculosis enzyme activity and neural signaling using fluorescent molecules. Each CURE laboratory involved multiple experimental phases and culminated in novel, open-ended, and reiterative student-driven research projects. Course assessments showed CURE participation increased students' experimental design skills, attitudes and confidence about research, perceived understanding of the scientific process, and interest in science, technology, engineering, and mathematics disciplines. More than 75% of CURE students also engaged in independent scientific research projects, and faculty CURE contributors saw substantial increases in research productivity, including increased undergraduate student involvement and academic outputs. Our collaborative CUREs demonstrate the advantages of multicourse CUREs for achieving increased faculty research productivity and traditional CURE-associated student learning and attitude gains. Our collaborative CURE design represents a novel CURE model for ongoing laboratory reform that benefits both faculty and students. © 2016 J. R. Kowalski et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  8. Professional development strategies for teaching urban biology teachers to use concept maps effectively

    Science.gov (United States)

    McGregor Petgrave, Dahlia M.

    Many teachers are not adequately prepared to help urban students who have trouble understanding conceptual ideas in biology because these students have little connection to the natural world. This study explored potential professional development strategies to help urban biology teachers use concept maps effectively with various topics in the biology curriculum. A grounded theory approach was used to develop a substantive professional development model for urban biology teachers. Qualitative data were collected through 16 semi-structured interviews of professional developers experienced in working with concept maps in the urban context. An anonymous online survey was used to collect quantitative data from 56 professional developers and teachers to support the qualitative data. The participants were from New York City, recruited through the NY Biology-Chemistry Professional Development Mentor Network and the NY Biology Teachers' Association. According to the participants, map construction, classroom applications, lesson planning, action research, follow-up workshops, and the creation of learning communities are the most effective professional development strategies. The interviewees also proposed English language learning strategies such as picture maps, native word maps, and content reading materials with underlined words. This study contributes to social change by providing a professional development model to use in planning workshops for urban teachers. Urban teachers improve their own conceptual understanding of biology while learning how to implement concept mapping strategies in the classroom. Students whose teachers are better prepared to teach biology in a conceptual manner have the potential of growing into more scientifically literate citizens.

  9. Implementation of Animal Dissection to Brush the Skills of Biology Experiments Up Qualitatively and the Influence

    OpenAIRE

    Sato, Takayuki; Torigoe, Kenji

    2007-01-01

    Animal dissection is good teaching method to understand animal livings directly. But, almost all the science teachers don't have enough experiences and skills about it. Therefore, we caused students to do several animal dissections and compare the results on teacher training of graduate school of university.The results of this study are as follow: 1) Mouse and Frogs as typical animals of dissection are good teaching material for observing overview of inner organs.2) The other vertebrate anima...

  10. Biological effects of methyl and ethyl mercury compounds used as disinfectants for seed-grain on domestic and wild life

    Energy Technology Data Exchange (ETDEWEB)

    Tejning, S

    1971-01-01

    A short survey of the harmful effects of methyl and ethyl mercury on wild and domestic life and on man since the introduction of these compounds in plant protection is given. The biological effects of methyl mercury in birds are illustrated by experiments in hens concerning its accumulation in their organs and plumage, its elimination in eggs and excrements and its influence on the health of the birds, their laying habits and egg production including the occurrence of embryonic damages and the hatchability. Attention is drawn to the ability of methyl mercury to cause genetical disorders. 14 references, 1 figure, 1 table.

  11. Soil degradation effect on biological activity in Mediterranean calcareous soils

    Science.gov (United States)

    Roca-Pérez, L.; Alcover-Sáez, S.; Mormeneo, S.; Boluda, R.

    2009-04-01

    Soil degradation processes include erosion, organic matter decline, compaction, salinization, landslides, contamination, sealing and biodiversity decline. In the Mediterranean region the climatological and lithological conditions, together with relief on the landscape and anthropological activity are responsible for increasing desertification process. It is therefore considered to be extreme importance to be able to measure soil degradation quantitatively. We studied soil characteristics, microbiological and biochemical parameters in different calcareous soil sequences from Valencia Community (Easter Spain), in an attempt to assess the suitability of the parameters measured to reflect the state of soil degradation and the possibility of using the parameters to assess microbiological decline and soil quality. For this purpose, forest, scrubland and agricultural soil in three soil sequences were sampled in different areas. Several sensors of the soil biochemistry and microbiology related with total organic carbon, microbial biomass carbon, soil respiration, microorganism number and enzyme activities were determined. The results show that, except microorganism number, these parameters are good indicators of a soil biological activity and soil quality. The best enzymatic activities to use like indicators were phosphatases, esterases, amino-peptidases. Thus, the enzymes test can be used as indicators of soil degradation when this degradation is related with organic matter losses. There was a statistically significant difference in cumulative O2 uptake and extracellular enzymes among the soils with different degree of degradation. We would like to thank Spanish government-MICINN for funding and support (MICINN, project CGL2006-09776).

  12. Biological effect of focal alpha radiation on the hamster lung

    International Nuclear Information System (INIS)

    Smith, D.M.; Anderson, E.C.; Prine, J.R.; Holland, L.M.; Richmond, C.R.

    1975-11-01

    Monodispersed 10-μm diameter ZrO 2 ceramic microspheres, containing varying amounts of 239 PuO 2 or 238 PuO 2 , were injected into the jugular vein of 100-day-old Syrian hamsters. These biologically inert microspheres lodged subsequently in pulmonary capillaries and remained static in position throughout the life span of the animals with no discernible inflammatory response. The numbers of microspheres injected ranged from 2000 to 10,000 and the specific activity from 0 to 59 pCi/sphere so that the lung burdens were 0 to 354 nCi/animal. At these numbers, each plutonium-laden microsphere served as an independent, focal source of alpha radiation. No consistent alteration of life spans post-exposure was seen in the experimental hamsters compared to controls. Pulmonary tissue responses were minimal with only 0.5 percent of the animals given Pu/ZrO 2 microspheres ultimately developing primary tumors of the lung. No unexpected gross or histologic lesion were found in other major body tissues

  13. Physics fundamentals and biological effects of synchrotron radiation therapy

    International Nuclear Information System (INIS)

    Prezado, Y.

    2010-01-01

    The main goal of radiation therapy is to deposit a curative dose in the tumor without exceeding the tolerances in the nearby healthy tissues. For some radioresistant tumors, like gliomas, requiring high doses for complete sterilization, the major obstacle for curative treatment with ionizing radiation remains the limited tolerance of the surrounding healthy tissue. This limitation is particularly severe for brain tumors and, especially important in children, due to the high risk of complications in the development of the central nervous system. In addition, the treatment of tumors close to an organ at risk, like the spinal cord, is also restricted. One possible solution is the development of new radiation therapy techniques exploiting radically different irradiation modes and modifying, in this way, the biological equivalent doses. This is the case of synchrotron radiation therapy (SRT). In this work the three new radiation therapy techniques under development at the European Synchrotron Radiation Facility (ESRF), in Grenoble (France) will be described, namely: synchrotron stereotactic radiation therapy (SSRT), microbeam radiation therapy (MRT) and minibeam radiation therapy. The promising results in the treatment of the high grade brain tumors obtained in preclinical studies have paved the way to the clinical trials. The first patients are expected in the fall of 2010. (Author).

  14. Integrating fluid dynamic and biologic effects on staphylococci bacteria biofilms

    Science.gov (United States)

    Sherman, Erica; Endres, Jennifer; Bayles, Kenneth; Wei, Timothy

    2017-11-01

    Staphylococcus aureus bacteria are able to form biofilms and distinctive tower structures that facilitate their ability to tolerate treatment and to spread within the human body. The formation of towers, which break off, get carried downstream and serve to initiate biofilms in other parts of the body are of particular interest here. In previous work on biofilm growth and evolution in steady, laminar microchannel flows, it has been established that tower formation occurs around a very limited range of applied shear stresses centered on 0.6 dynes/cm2. Quantifying cell density characteristics as a function of time during biofilm formation reveals indicators of tower development hours before towers actually form and become visible. The next step in this research is to explore biological factors that might explain why this specific shear is so important. Additional studies with mutants, e.g. ica-A, that have been tied to tower formation have been conducted. The shear dependence of these mutants and their correlation to the behavior of wild type S. aureus is examined.

  15. Starting point anchoring effects in choice experiments

    DEFF Research Database (Denmark)

    Ladenburg, Jacob; Olsen, Søren Bøye

    of preferences in Choice Experiments resembles the Dichotomous Choice format, there is reason to suspect that Choice Experiments are equally vulnerable to anchoring bias. Employing different sets of price levels in a so-called Instruction Choice Set presented prior to the actual choice sets, the present study...... subjectivity in the present study is gender dependent, pointing towards, that female respondents are prone to be affected by the price levels employed. Male respondents, on the other hand, are not sensitive towards these prices levels. Overall, this implicates that female respondents, when employing a low......-priced Instruction Choice Set, tend to express lower willingness-to-pay than when higher prices are employed....

  16. Biological effects of radon in Drosophila; Efectos biologicos del radon en Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel P, A E; Tavera D, L; Cruces M, M P; Arceo M, C; Rosa D, M.E. de la

    1992-04-15

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  17. High voltage electric field effects on structure and biological characteristics of barley seeds

    Energy Technology Data Exchange (ETDEWEB)

    Khazaei, J. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Agrotechnology, Univ. College of Abouraihan; Aliabadi, E. [Tehran Univ., Tehran (Iran, Islamic Republic of). Dept. of Crop Production Horticulture, Univ. College of Aburaihan; Shayegani, A.A. [Tehran Univ., Tehran (Iran, Islamic Republic of). Univ. College of Engineering

    2010-07-01

    Electric biostimulation of seeds is a pre-sowing treatment in which an electric field is applied to seeds to increase germination of non standard seeds. This paper reported on a study that examined the effects of AC electric field and exposure time on the structure and biological characteristics of barley seeds. The objective was to determine the potential to accelerate seed germination, plant growth and root development by the electric field strength and exposure time. Makooei cultivar barley seeds were used in this study. The effect of electric field strength (at 2, 4, 9, and 14 kV/m) and exposure time (at 15, 45, 80, and 150 min) on seed germination was studied along with height of seedling, length or root, height of stem, length of leaves, earliness, dry weight and wet weight of seedling. The treated seeds were stored for a month in a refrigerator at 5 degrees C prior to the germination experiments. The initial germination percent of the seed was 81 per cent. The treatment of barley seeds in an AC electric field had a positive effect on all investigated parameters. The germination percent of the treated seed increased to 94.5 per cent . The seeds exposed for long periods of time (45 to 150 min) showed better germination than the seeds exposed to lower exposure times. Dry and wet weights of seedling increased 143.4 per cent and 45.7 per cent, respectively.

  18. Biological effects of radon in Drosophila; Efectos biologicos del radon en Drosophila

    Energy Technology Data Exchange (ETDEWEB)

    Pimentel P, A.E.; Tavera D, L.; Cruces M, M.P.; Arceo M, C.; Rosa D, M.E. de la

    1992-04-15

    The main objective of this investigation, is to study the biological effects of the Radon-222 at low dose in 'Drosophila melanogaster'. It is necessary to mention that these effects will analyze from the genetic point of view for: 1) To evaluate in which form the Radon-222 to low dose it influences in some genetic components of the adaptation in Drosophila, such as: fecundity, viability egg-adult and sex proportion. 2) To evaluate which is the genetic effect that induces the Radon to low dose by means of the SMART technique in Drosophila melanogaster, and this way to try of to identify which is the possible mechanism that causes the genetic damage to somatic level. The carried out investigation was divided in three stages: 1. Tests to the vacuum resistance. 2. Test of somatic mutation, and 3. Determination of the presence of radon daughters on the adult of Drosophila. It is necessary to point out that all the experiments were made by triplicate and in each one of them was placed detectors in preset places. Those obtained results are presented inside the 4 charts included in the present work. (Author)

  19. Theoretical description of protein field effects on electronic excitations of biological chromophores

    International Nuclear Information System (INIS)

    Varsano, Daniele; Caprasecca, Stefano; Coccia, Emanuele

    2017-01-01

    Photoinitiated phenomena play a crucial role in many living organisms. Plants, algae, and bacteria absorb sunlight to perform photosynthesis, and convert water and carbon dioxide into molecular oxygen and carbohydrates, thus forming the basis for life on Earth. The vision of vertebrates is accomplished in the eye by a protein called rhodopsin, which upon photon absorption performs an ultrafast isomerisation of the retinal chromophore, triggering the signal cascade. Many other biological functions start with the photoexcitation of a protein-embedded pigment, followed by complex processes comprising, for example, electron or excitation energy transfer in photosynthetic complexes. The optical properties of chromophores in living systems are strongly dependent on the interaction with the surrounding environment (nearby protein residues, membrane, water), and the complexity of such interplay is, in most cases, at the origin of the functional diversity of the photoactive proteins. The specific interactions with the environment often lead to a significant shift of the chromophore excitation energies, compared with their absorption in solution or gas phase. The investigation of the optical response of chromophores is generally not straightforward, from both experimental and theoretical standpoints; this is due to the difficulty in understanding diverse behaviours and effects, occurring at different scales, with a single technique. In particular, the role played by ab initio calculations in assisting and guiding experiments, as well as in understanding the physics of photoactive proteins, is fundamental. At the same time, owing to the large size of the systems, more approximate strategies which take into account the environmental effects on the absorption spectra are also of paramount importance. Here we review the recent advances in the first-principle description of electronic and optical properties of biological chromophores embedded in a protein environment. We show

  20. Theoretical description of protein field effects on electronic excitations of biological chromophores

    Science.gov (United States)

    Varsano, Daniele; Caprasecca, Stefano; Coccia, Emanuele

    2017-01-01

    Photoinitiated phenomena play a crucial role in many living organisms. Plants, algae, and bacteria absorb sunlight to perform photosynthesis, and convert water and carbon dioxide into molecular oxygen and carbohydrates, thus forming the basis for life on Earth. The vision of vertebrates is accomplished in the eye by a protein called rhodopsin, which upon photon absorption performs an ultrafast isomerisation of the retinal chromophore, triggering the signal cascade. Many other biological functions start with the photoexcitation of a protein-embedded pigment, followed by complex processes comprising, for example, electron or excitation energy transfer in photosynthetic complexes. The optical properties of chromophores in living systems are strongly dependent on the interaction with the surrounding environment (nearby protein residues, membrane, water), and the complexity of such interplay is, in most cases, at the origin of the functional diversity of the photoactive proteins. The specific interactions with the environment often lead to a significant shift of the chromophore excitation energies, compared with their absorption in solution or gas phase. The investigation of the optical response of chromophores is generally not straightforward, from both experimental and theoretical standpoints; this is due to the difficulty in understanding diverse behaviours and effects, occurring at different scales, with a single technique. In particular, the role played by ab initio calculations in assisting and guiding experiments, as well as in understanding the physics of photoactive proteins, is fundamental. At the same time, owing to the large size of the systems, more approximate strategies which take into account the environmental effects on the absorption spectra are also of paramount importance. Here we review the recent advances in the first-principle description of electronic and optical properties of biological chromophores embedded in a protein environment. We show

  1. History on the biological nitrogen fixation research in graminaceous plants: special emphasis on the Brazilian experience.

    Science.gov (United States)

    Baldani, José I; Baldani, Vera L D

    2005-09-01

    This review covers the history on Biological Nitrogen Fixation (BNF) in Graminaceous plants grown in Brazil, and describes research progress made over the last 40 years, most of which was coordinated by Johanna Döbereiner. One notable accomplishment during this period was the discovery of several nitrogen-fixing bacteria such as the rhizospheric (Beijerinckia fluminensis and Azotobacter paspali), associative (Azospirillum lipoferum, A. brasilense, A. amazonense) and the endophytic (Herbaspirillum seropedicae, H. rubrisubalbicans, Gluconacetobacter diazotrophicus, Burkholderia brasilensis and B. tropica). The role of these diazotrophs in association with grasses, mainly with cereal plants, has been studied and a lot of progress has been achieved in the ecological, physiological, biochemical, and genetic aspects. The mechanisms of colonization and infection of the plant tissues are better understood, and the BNF contribution to the soil/plant system has been determined. Inoculation studies with diazotrophs showed that endophytic bacteria have a much higher BNF contribution potential than associative diazotrophs. In addition, it was found that the plant genotype influences the plant/bacteria association. Recent data suggest that more studies should be conducted on the endophytic association to strengthen the BNF potential. The ongoing genome sequencing programs: RIOGENE (Gluconacetobacter diazotrophicus) and GENOPAR (Herbaspirillum seropedicae) reflect the commitment to the BNF study in Brazil and should allow the country to continue in the forefront of research related to the BNF process in Graminaceous plants.

  2. Biocinema: the experience of using popular movies with students of Biology

    Directory of Open Access Journals (Sweden)

    Josep-Eladi Baños Díez

    2008-10-01

    Full Text Available Popular movies may be successfully used as a teaching aid in health sciences studies. In the last three years we have been using popular movies in an activity called Biocinema during the first trimester with students of fifth year of Biology at the Universitat Pompeu Fabra. The activity was planned to help the students to consider the social aspects of their future professional career. Six different films were used: Outbreak, Lorenzo's oil, The Boys from Brazil, Frankenstein, Le maladie de Sachs and The Andromeda strain. The activity was organized in three steps. First, students watched the film after a brief introduction by one of the teachers who were responsible for the activity. Second, this teacher organized an open discussion with the students during the next hour. Third, students wrote a brief report on one of the topics portrayed in the film or mentioned in the open discussion. These reports were further evaluated and contributed a maximum extrabonus of 0.5 points over 10 in the scoring of the regular topics covered in the trimester.

  3. Bioaccumulation and biological effects in the earthworm Eisenia fetida exposed to natural and depleted uranium

    Energy Technology Data Exchange (ETDEWEB)

    Giovanetti, Anna, E-mail: anna.giovanetti@enea.i [ENEA, Institute of Radiation Protection, CR Casaccia Via Anguillarese 301, 00123 Rome (Italy); Fesenko, Sergey [International Atomic Energy Agency (IAEA), Agency' s Laboratories Seibersdorf, A-2444 Seibersdorf (Austria); Cozzella, Maria L. [ENEA, National Institute for Metrology of Ionizing Radiation, CR Casaccia Via Anguillarese 301, 00123 Rome (Italy); Asencio, Lisbet D. [Centro de Estudios Ambientales, Carretera a Castillo de Jagua, CP. 59350 C. Nuclear, Cienfuegos (Cuba); Sansone, Umberto [International Atomic Energy Agency (IAEA), Agency' s Laboratories Seibersdorf, A-2444 Seibersdorf (Austria)

    2010-06-15

    The accumulations of both natural (U) and depleted (DU) uranium in the earthworms (Eisenia fetida) were studied to evaluate corresponding biological effects. Concentrations of metals in the experimental soil ranged from 1.86 to 600 mg kg{sup -1}. Five biological endpoints: mortality, animals' weight increasing, lysosomal membrane stability by measuring the neutral red retention time (the NRRT), histological changes and genetic effects (Comet assay) were used to evaluate biological effects in the earthworms after 7 and 28 days of exposure. No effects have been observed in terms of mortality or weight reduction. Cytotoxic and genetic effects were identified at quite low U concentrations. For some of these endpoints, in particular for genetic effects, the dose (U concentration)-effect relationships have been found to be non-linear. The results have also shown a statistically significant higher level of impact on the earthworms exposed to natural U compared to depleted U.

  4. Bioaccumulation and biological effects in the earthworm Eisenia fetida exposed to natural and depleted uranium

    International Nuclear Information System (INIS)

    Giovanetti, Anna; Fesenko, Sergey; Cozzella, Maria L.; Asencio, Lisbet D.; Sansone, Umberto

    2010-01-01

    The accumulations of both natural (U) and depleted (DU) uranium in the earthworms (Eisenia fetida) were studied to evaluate corresponding biological effects. Concentrations of metals in the experimental soil ranged from 1.86 to 600 mg kg -1 . Five biological endpoints: mortality, animals' weight increasing, lysosomal membrane stability by measuring the neutral red retention time (the NRRT), histological changes and genetic effects (Comet assay) were used to evaluate biological effects in the earthworms after 7 and 28 days of exposure. No effects have been observed in terms of mortality or weight reduction. Cytotoxic and genetic effects were identified at quite low U concentrations. For some of these endpoints, in particular for genetic effects, the dose (U concentration)-effect relationships have been found to be non-linear. The results have also shown a statistically significant higher level of impact on the earthworms exposed to natural U compared to depleted U.

  5. Biological effects of extreme environmental conditions. [considering limits of biosphere

    Science.gov (United States)

    Imshenetskiy, A. A.

    1975-01-01

    Actions of extreme physical and chemical space factors on microorganisms and plants are elaborated in order to establish limits for the biosphere. Considered are effects of low and high temperatures; ionizing and ultraviolet radiation; various gases; and effects of vibration, desiccation and acceleration.

  6. Biological effects under combined action of radiation and chemical factors

    International Nuclear Information System (INIS)

    Malenchenko, A.F.

    1990-01-01

    The paper considers the manifoild factors of environmental pollution effect upon living organisms and their possible response manifested in additivity, synergism and anthogonism. Consideration is also given to the possible practical measures for improving ecological situation and decreasing the risk of anthropogenesis negative after-effects

  7. Radiations from GSM Base Stations and its Biological Effects

    African Journals Online (AJOL)

    Michael Horsfall

    All rights reserved ... radiofrequency radiations on albino mice placed in exposure cages and ... information in Nigeria on the possible effects of the .... The slides were left to dry on the hot plate ... potential health effect of the RF radiations. It is also a pointer to the need for .... The telecommunication industry is an essential.

  8. Some biological effects of high-voltage stationary electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Antipov, V.V.; Dobrov, N.N.; Drobyshev, V.I.; Koroleva, L.V.; Nikitin, M.D.; Petrukhin, S.V.; Semonova, L.A.; Fedorov, V.P.

    The experiments were carried out on 345 white mice using hematological and pathomorphological procedures. The constant electric field (CEF) was generated in a special laboratory device. The exposure to CEF of 50 and 100 kV/m for 20 s caused hematological and morphological changes typical of the anxiety stage of the adaptation syndrome. The exposure also produced morphological changes of reactive and destructive type in skeletal muscles and different segments of kinesthetic receptors. The level of the above changes appears to be directly related to the CEF strength. 6 references, 4 figures, 1 table.

  9. Medical-biological aspects of radiation effects in Daphnia magna

    International Nuclear Information System (INIS)

    Sarapultseva, E; Ustenko, K; Uskalova, D; Savina, N

    2017-01-01

    We have shown that γ-irradiation at doses of 100 and 1000 mGy significantly compromised fecundity and reproductive success of the directly exposed D. magna . These effects were also observed among the non-exposed first-generation progeny of irradiated parents, thus implying the manifestation of transgenerational effects in Daphnia . We have also shown that compromised viability of irradiated D. magna can be attributed cytotoxic effects of irradiation. It would therefore appear that the compromised viability may be attributed to the cytotoxic effects resulted from epigenetic changes affecting some metabolic pathways involved in detoxification of free-radicals. Additionally we have analyzed more distant progeny of irradiated at doses of 10, 100 and 1000 mGy Daphnia . Our data demonstrated that multicellular crustacean D. magna represent a very useful experimental model for analyse of long-term effects of ionising radiation at the organismal level. (paper)

  10. Effective Teamwork: The EVA NBL Experience

    Science.gov (United States)

    Crocker, Lori

    2007-01-01

    This viewgraph presentation reviews the experience of improving the operation of the ExtraVehiclar Activity (EVA) Neutral Buoyancy Laboratory as a team of NASA employees and contractors. It reviews specific recommendations to use in turning a struggling organization around as a NASA/contractor team

  11. Epigenetic Effects of Diet on Fruit Fly Lifespan: An Investigation to Teach Epigenetics to Biology Students

    Science.gov (United States)

    Billingsley, James; Carlson, Kimberly A.

    2010-01-01

    Do our genes exclusively control us, or are other factors at play? Epigenetics can provide a means for students to use inquiry-based methods to understand a complex biological concept. Students research and design an experiment testing whether dietary supplements affect the lifespan of Drosophila melanogaster over multiple generations.

  12. Effect of continuous addition of an organic substrate to the anoxic phase on biological phosphorus removal

    DEFF Research Database (Denmark)

    Meinhold, Jens; Pedersen, Heinz; Arnold, Eva

    1998-01-01

    The continuous introduction of a biological phosphorus removal (BPR) promoting organic substrate to the denitrifying reactor of a BPR process is examined through a series of batch experiments using acetate as model organic substrate. Several observations are made regarding the influence of substr...

  13. The effects of experience and attrition for novice high-school science and mathematics teachers.

    Science.gov (United States)

    Henry, Gary T; Fortner, C Kevin; Bastian, Kevin C

    2012-03-02

    Because of the current high proportion of novice high-school teachers, many students' mastery of science and mathematics depends on the effectiveness of early-career teachers. In this study, which used value-added models to analyze high-school teachers' effectiveness in raising test scores on 1.05 million end-of-course exams, we found that the effectiveness of high-school science and mathematics teachers increased substantially with experience but exhibited diminishing rates of return by their fourth year; that teachers of algebra 1, algebra 2, biology, and physical science who continued to teach for at least 5 years were more effective as novice teachers than those who left the profession earlier; and that novice teachers of physics, chemistry, physical science, geometry, and biology exhibited steeper growth in effectiveness than did novice non-science, technology, engineering, and mathematics teachers.

  14. Relative biological effectiveness (RBE) of proton beams in radiotherapy

    International Nuclear Information System (INIS)

    Calugaru, V.

    2011-01-01

    Treatment planning in proton therapy uses a generic value for the Relative Biological Efficiency (RBE) of 1.1 relative to 60 Co gamma-rays throughout the Spread Out Bragg Peak (SOBP). We have studied the variation of the RBE at three positions in the SOBP of the 76 and 201 MeV proton beams used for cancer treatment at the Institut Curie Proton Therapy in Orsay (ICPO) in two human tumor cell lines using clonogenic cell death and the incidence of DNA double-strand breaks (DSB) as measured by pulse-field gel electrophoresis without and with endonuclease treatment to reveal clustered lesions as endpoints.The RBE for induced cell killing by the 76 MeV beam increased with depth in the SOBP. However for the 201 MeV protons it was close to that for 137 Cs gamma-rays and did not vary significantly. The incidence of DSBs and clustered lesions was higher for protons than for 137 Cs g-rays, but did not depend on the proton energy or the position in the SOBP. In the second part of our work, we have shown using cell clones made deficient for known repair genes by stable or transient shRNA transfection, that the D-NHEJ pathway determine the response to protons. The response of DNA damages created in the distal part of the 76 MeV SOBP suggests that those damages belong to the class of DNA 'complex lesions' (LMDS). It also appears that the particle fluence is a major determinant of the outcome of treatment in the distal part of the SOBP. (author)

  15. Lung Deposition And Biological Effects Of Inhaled Radon Progenies

    International Nuclear Information System (INIS)

    Balashazy, I.; Farkas, A.; Szoke, I.; Moustafa, M.; Kudela, G.

    2010-01-01

    Inhaled radon progenies provide more than the half of natural radiation exposure. There is increasing evidence that the cellular distribution of radiation burden is an important factor regarding the biological response to ionisation radiation, thus, one of our tasks was the characterisation of the distribution of cellular exposure. Histological studies of former uranium miners presented strong correlation between primer deposition hot spots and neoplastic lesions. Most of these lesions were located along the carinal regions of the large bronchial airways. In the present work, computational fluid dynamics (CFD) approaches have been applied to simulate the deposition distribution of inhaled radon progenies along central human airways. The geometry and the cellular structure of epithelial lung tissue were numerically reconstructed based on anatomical and histological data. Single and multiple ha-hit and cellular dose distributions have been computed applying Monte Carlo modelling techniques at different breathing conditions. Figure 1. Deposition enhancement factor (EF) of inhaled radon progenies on a central airway bifurcation in airway generations 4-5 during light physical activity breathing condition. Size of scanning surface element is a 45μm side triangle. Left panel: EF max=1400,Dp=200 nm (attached). Right panel: EF max1290, Dp= 1 nm (unattached). Values of local per average deposition densities, that is, enhancement factors (Figure 1), hit probabilities and doses may be up to two-three orders of magnitude higher in the deposition hot spots than the average values. Dose calculations revealed that some cell clusters may receive high doses even at low exposure conditions. Applying the model to different radiation exposure conditions useful relations can be received regarding the linear-non threshold hypothesis

  16. Effect of ozonation on the biological treatability of a textile mill effluent.

    Science.gov (United States)

    Karahan, O; Dulkadiroglu, H; Kabdasli, I; Sozen, S; Babuna, F Germirli; Orhon, D

    2002-12-01

    Ozonation applied prior to biological processes, has proved to be a very effective chemical treatment step mostly for colour removal when soluble dyes are used in textile finishing operations. Its impact on biological treatability however has not been fully evaluated yet. This study evaluates the effect of ozonation on the quality of wastewater from a textile mill involving bleaching and reactive dyeing of cotton and synthetic knit fabric. The effect of ozonation on COD fractionation and kinetic coefficients defining major biological processes is emphasised. The results indicate that the extent of ozone applied greatly affects the remaining organic carbon composition in the wastewater. The relative magnitude of different COD fractions varies as a function of the ozone dose. Ozonation does not however exert a measurable impact on the rate of major biological processes.

  17. Biological Effects of Interaction between Radiation and Chemicals

    Energy Technology Data Exchange (ETDEWEB)

    Hyun, Kyung Man; Han, Min; Kim, Jin Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Nili, Mohammad [Dawnesh Radiation Research Institute, Barcelona (Spain)

    2009-05-15

    The organisms are exposed to natural radiations from cosmic or terrestrial origins. Radiation is known to cause cell death, mainly due to its ability to produce reactive oxygen species in cells. The combined action between radiation and various chemicals is a distinguishing feature of modern life. Mercury chloride is a widespread environmental pollutant that is known to have toxic effects. Synergistic effects of radiation and HgCl{sub 2} on human cells was previously reported. NAC is a well-known sulfhydryl-containing antioxidant whose role in radioprotection has been explored in several studies. There has been an increasing interest of studying the role of NAC as a radioprotective substance. The present study was designed not only to assess the synergistic effects between radiation and HgCl{sub 2}, but also to investigate protective effects of NAC on cells.

  18. Biological and medical effects of UV radiation on human health

    International Nuclear Information System (INIS)

    Piazena, H.

    1994-01-01

    Effecsts of UV radiation on human health are discussed. UV radiation is taken up through the skin and eyes. In the case of the eyes, the only known effects are damaging ones (e.g. cataracts). Irradiation of the skin, on the other hand, may either have a prophylactic and therapeutic effect or cause health problems if the exposure is too frequent and/or the dose too high. Positive effects are: Stimulation of the vitamin-D-3 synthesis and the autoimmune system, economisation of blood circulation, higher fitness, and the development of a UV protection system in the skin. Negative effects are: UV erythema, disturbances of the unspecific resistance and the immune system, and photocarcinogenesis. (orig.) [de

  19. Biological and technological effects of some mulberry varieties and ...

    African Journals Online (AJOL)

    egyptian hak

    synthesize different types of antioxidant compounds and activate key ... the nutrient uptake of rice plants, especially phosphorous and potassium (Wu et al ... agricultural products and cause detrimental effects to environment and human health.

  20. Effects of Biologic Agents in Patients with Rheumatoid Arthritis and Amyloidosis Treated with Hemodialysis.

    Science.gov (United States)

    Kuroda, Takeshi; Tanabe, Naohito; Nozawa, Yukiko; Sato, Hiroe; Nakatsue, Takeshi; Kobayashi, Daisuke; Wada, Yoko; Saeki, Takako; Nakano, Masaaki; Narita, Ichiei

    Objective Our objective was to examine the safety and effects of therapy with biologics on the prognosis of rheumatoid arthritis (RA) patients with reactive amyloid A (AA) amyloidosis on hemodialysis (HD). Methods Twenty-eight patients with an established diagnosis of reactive AA amyloidosis participated in the study. The survival was calculated from the date of HD initiation until the time of death, or up to end of June 2015 for the patients who were still alive. HD initiation was according to the program of HD initiation for systemic amyloidosis patients associated with RA. Results Ten patients had been treated with biologics before HD initiation for a mean of 28.2 months (biologic group), while 18 had not (non-biologic group). HD was initiated in patients with similar characteristics except for the tender joint count, swollen joint count, and disease activity score (DAS)28-C-reactive protein (CRP). History of biologics showed that etanercept was frequently used for 8 patients as the first biologic. There was no significant difference in the mortality rate according to a Kaplan-Meier analysis (p=0.939) and or associated risk of death in an age-adjusted Cox proportional hazards model (p=0.758) between both groups. Infections were significantly more frequent causes of death in the biologic group than in the non-biologic group (p=0.021). However, treatment with biologics improved the DAS28-CRP score (p=0.004). Conclusion Under the limited conditions of AA amyloidosis treated with HD, the use of biologics might affect infection and thus may not improve the prognosis. Strict infection control is necessary for the use of biologics with HD to improve the prognosis.

  1. Using counterfactuals to evaluate the cost-effectiveness of controlling biological invasions.

    Science.gov (United States)

    McConnachie, Matthew M; van Wilgen, Brian W; Ferraro, Paul J; Forsyth, Aurelia T; Richardson, David M; Gaertner, Mirijam; Cowling, Richard M

    2016-03-01

    Prioritizing limited conservation funds for controlling biological invasions requires accurate estimates of the effectiveness of interventions to remove invasive species and their cost-effectiveness (cost per unit area or individual). Despite billions of dollars spent controlling biological invasions worldwide, it is unclear whether those efforts are effective, and cost-effective. The paucity of evidence results from the difficulty in measuring the effect of invasive species removal: a researcher must estimate the difference in outcomes (e.g. invasive species cover) between where the removal program intervened and what might have been observed if the program had not intervened. In the program evaluation literature, this is called a counterfactual analysis, which formally compares what actually happened and what would have happened in the absence of an intervention. When program implementation is not randomized, estimating counterfactual outcomes is especially difficult. We show how a thorough understanding of program implementation, combined with a matching empirical design can improve the way counterfactual outcomes are estimated in nonexperimental contexts. As a practical demonstration, we estimated the cost-effectiveness of South Africa's Working for Water program, arguably the world's most ambitious invasive species control program, in removing invasive alien trees from different land use types, across a large area in the Cape Floristic Region. We estimated that the proportion of the treatment area covered by invasive trees would have been 49% higher (5.5% instead of 2.7% of the grid cells occupied) had the program not intervened. Our estimates of cost per hectare to remove invasive species, however, are three to five times higher than the predictions made when the program was initiated. Had there been no control (counter-factual), invasive trees would have spread on untransformed land, but not on land parcels containing plantations or land transformed by

  2. Biological effect of 60Co γ irradiation on Trichoderma

    International Nuclear Information System (INIS)

    Chen Jian'ai; Wang Weiming

    2003-01-01

    The mutagenic effect of 60 Co γ-ray on Trichoderma spp (T 32 ) was studied. The germination capacity of spores apparently declined after irradiation. The mutagenic effect curve model is S=e -λD , and the mutagenic curve is Y=-0.940e 1.29x , r=0.9533(r 0.01 =0.765). 130 variant strain which grew rapidly and produced more spores were chosen

  3. Psychological and Biological Validation of a Novel Digital Social Peer Evaluation Experiment (digi-SPEE)

    NARCIS (Netherlands)

    Menne-Lothmann, Claudia; Decoster, Jeroen; van Winkel, Ruud; Collip, Dina; Rutten, Bart P. F.; Delespaul, Philippe; De Hert, Marc; Derom, Catherine; Thiery, Evert; Jacobs, Nele; van Os, Jim; Wichers, Marieke

    Introduction: Negative social evaluation is associated with psychopathology. Given the frequency of evaluation through increasingly prevalent virtual social networks, increased understanding of the effects of this social evaluation is urgently required. Methods: A new digital social peer evaluation

  4. Psychological Effects towards Humans Living in the Environment Made of Biological Concrete in Malaysia at 2015

    Directory of Open Access Journals (Sweden)

    Amirreza Talaiekhozani

    2017-01-01

    Full Text Available In day-to-day life concrete become a compulsory material in the construction field as to make it a real concern among researchers for producing concrete with improved properties. Biological method is one of the new methods to improve concrete properties. Although, much research about biological concrete has been carried out, but till now nobody has not studied for the psychological effects of using a house or offices made up of biological concrete. The aim of this study is to investigate and find out the person's opinion about staying in a house or offices made up of biological concrete. In this study, a questionnaire containing eight questions was prepared and distributed among 21 persons in Malaysia University of Technology including students, academic and non-academic staffs among which few of them was an expert in the field of biological concrete and others did not have any knowledge about the bioconcrete. Finally, the results obtained from the questionnaires were analyzed. The results showed that 81% of participants in this study would like to stay in a house or office made up of biological concrete. However, 38% of participants believe that staying in a house or office made of biological concrete can cause health related problems. The current research paper can be considered significant for architects and civil engineers to have the insight to look into the psychological aspects of using biological concrete for various applications in the field of construction.

  5. Progress Toward a Thermal-Hydrological-Mechanical-Chemical-Biological (THMCB) Experiment in the Homestake Mine Deep Underground Science and Engineering Laboratory

    Science.gov (United States)

    Sonnenthal, E. L.; Maher, K.; Elsworth, D.; Lowell, R. P.; Uzunlar, N.; Mailloux, B. J.; Conrad, M. E.; Olsen, N. J.; Jones, T. L.; Cruz, M. F.; Torchinsky, A.

    2011-12-01

    The purpose of performing a long-term hydrothermal experiment in a deep mine is to gain a scientific understanding of the coupled physical, chemical, and biological processes taking place in fractured rock under the influence of mechanical stress, thermal effects, and fluid flow. Only in a controlled experiment in a well-characterized rock mass, can a fractured rock be probed in 3-D through geophysical imaging, in situ measurements, geochemical/biological sampling, and numerical modeling. Our project is focused on the feasibility of a THMCB experiment in the Homestake Mine, South Dakota to study the long-term evolution (10+ years) of a perturbed heterogeneous rock mass. In addition to the experiment as a laboratory for studying crustal processes, it has direct application to Enhanced Geothermal Systems, carbon sequestration, and contaminant transport. Field activities have focused on fracture and feature mapping, flux measurements from flowing fractures, and collection of water and rock samples for geochemical, biological, and isotopic analyses. Fracture mapping and seepage measurements are being used to develop estimates of permeability and fluxes at different length scales and design the location and orientation of the heater array. Fluxes measured up to several liters/minute indicate localized regions of very high fracture permeability, likely in excess of 10-10 m2. Isotopic measurements indicate heterogeneity in the fracture network on the scale of tens of meters in addition to the large-scale geochemical heterogeneity observed in the mine. New methods for sampling and filtering water samples were developed and tested with the goal of performing radiocarbon analyses in DNA and phospholipid fatty acids. Analytical and numerical models of the thermal perturbation have been used to design the heater orientation and spacing. Reaction path and THC simulations were performed to assess geochemical and porosity/permeability changes as a function of the heat input

  6. Hygienic aspects of biological effects of ultraviolet radiation in industry

    International Nuclear Information System (INIS)

    Zoz, N.I.; Taub, A.A.; Shafranov, B.V.

    1975-01-01

    This review is concerned with the positive and negative effects of UV-irradiation on the organism of humans and animals. UV-irradiation (200-300 nm) has been shown to cause inactivation of the principal cell compounds, destruction of nuclei, and cleavages in nucleic acid, protein and enzyme chains. In humans, UV-rays directly affect the skin and eyes. Some investigations have established a dependence between the wave length, absorbed quanta energies and morphological alterations in skin structures. These alterations have been revealed in erythema and sun tan. Evidence is cited on the unfavourable effect of ''hyperirradiation'' on the organism of test animals. ''Hyperirradiation'' has moreover been shown to intensify the negative effects of methyl mercaptophosis [ru

  7. Some features of irradiated chitosan and its biological effect

    Energy Technology Data Exchange (ETDEWEB)

    Hai, Le; Hien, Nguyen Quoc; Luan, Le Quang; Hanh, Truong Thi; Man, Nguyen Tan; Ha, Pham Thi Le; Thuy, Tran Thi [Nuclear Research Institute, VAEC, Dalat (Viet Nam); Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-03-01

    Preparation of chitosan oligomer by radiation degradation was carried out on the gamma Co-60 source. The radiation degradation yield (G{sub d}) of the chitosan was found to be of 1.03. The oligochitosan with 50% of dp>8 fraction was obtained by irradiating the 10% (w/v) chitosan solution in 5% acetic acid at 45 kGy for the chitosan having the initial viscometric average molecular weight, Mv=60,000. Irradiated chitosan showed higher antifungal effect than that of unirradiated one. Furthermore, the irradiated chitosan also showed the growth-promotion effect for plants. (author)

  8. Electrical and Biological Effects of Transmission Lines: A Review.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jack M.

    1989-06-01

    This review describes the electrical properties of a-c and d-c transmission lines and the resulting effects on plants, animals, and people. Methods used by BPA to mitigate undesirable effects are also discussed. Although much of the information in this review pertains to high-voltage transmission lines, information on distribution lines and electrical appliances is included. The electrical properties discussed are electric and magnetic fields and corona: first for alternating-current (a-c) lines, then for direct current (d-c).

  9. Some features of irradiated chitosan and its biological effect

    International Nuclear Information System (INIS)

    Hai, Le; Hien, Nguyen Quoc; Luan, Le Quang; Hanh, Truong Thi; Man, Nguyen Tan; Ha, Pham Thi Le; Thuy, Tran Thi; Yoshii, Fumio; Kume, Tamikazu

    2001-01-01

    Preparation of chitosan oligomer by radiation degradation was carried out on the gamma Co-60 source. The radiation degradation yield (G d ) of the chitosan was found to be of 1.03. The oligochitosan with 50% of dp>8 fraction was obtained by irradiating the 10% (w/v) chitosan solution in 5% acetic acid at 45 kGy for the chitosan having the initial viscometric average molecular weight, Mv=60,000. Irradiated chitosan showed higher antifungal effect than that of unirradiated one. Furthermore, the irradiated chitosan also showed the growth-promotion effect for plants. (author)

  10. Cytotoxic and biological effects of bulk fill composites on rat cortical neuron cells.

    Science.gov (United States)

    Kamalak, Hakan; Kamalak, Aliye; Taghizadehghalehjoughi, Ali; Hacımüftüoğlu, Ahmet; Nalcı, Kemal Alp

    2018-03-28

    The aim of this study was to investigate potential cellular responses and biological effects of new generation dental composites on cortical neuron cells in two different exposure times. The study group included five different bulk-fill flow able composites; Surefil SDR Flow, X-tra Base Flow, Venus Bulk Flow, Filtek Bulk Flow and Tetric-Evo Flow. They were filled in Teflon molds (Height: 4 mm, Width: 6 mm) and irradiated for 20 s. Cortical neuron cells were inoculated into 24-well plates. After 80% of the wells were coated, the 3 µm membrane was inserted and dental filling materials were added. The experiment was continued for 24 and 72 h. Cell viability measured by MTT assay test, total antioxidant and total oxidant status were examined using real assay diagnostic kits. The patterns of cell death (apoptosis) were analyzed using annexin V-FITC staining with flow cytometry. Β-defensins were quantitatively assessed by RT-PCR. IL-6, IL-8 and IL-10 cytokines were measured from the supernatants. All composites significantly affected analyses parameters during the exposure durations. Our data provide evidence that all dental materials tested are cytotoxic in acute phase and these effects are induced cellular death after different exposure periods. Significant cytotoxicity was detected in TE, XB, SS, FBF and VBF groups at 24 and 72 h, respectively.

  11. [Arbuscular mycorrhizal symbiosis influences the biological effects of nano-ZnO on maize].

    Science.gov (United States)

    Wang, Wei-Zhong; Wang, Fa-Yuan; Li, Shuai; Liu, Xue-Qin

    2014-08-01

    Engineered nanoparticles (ENPs) can be taken up and accumulated in plants, then enter human bodies via food chain, and thus cause potential health risk. Arbuscular mycorrhizal fungi form mutualistic symbioses with the majority of higher plants in terrestrial ecosystems, and potentially influence the biological effects of ENPs. The present greenhouse pot culture experiment studied the effects of inoculation with or without arbuscular mycorrhizal fungus Acaulospora mellea on growth and nutritional status of maize under different nano-ZnO levels (0, 500, 1 000, 2000 and 3 000 mg x kg(-1)) artificially added into soil. Results showed that with the increasing nano-ZnO levels in soil, mycorrhizal colonization rate and biomass of maize plants showed a decreasing trend, total root length, total surface area and total volume reduced, while Zn concentration and uptake in plants gradually increased, and P, N, K, Fe, and Cu uptake in shoots all decreased. Compared with the controls, arbuscular mycorrhizal inoculation improved the growth and P, N and K nutrition of maize, enhanced total root length, total surface area and total volume, and increased Zn allocation to roots when nano-ZnO was added. Our results firstly show that nano-ZnO in soil induces toxicity to arbuscular mycorrhizae, while arbuscular mycorrhizal inoculation can alleviate its toxicity and play a protective role in plants.

  12. Non-visual biological effects of light on human cognition, alertness, and mood

    Science.gov (United States)

    Li, Huaye; Wang, Huihui; Shen, Junfei; Sun, Peng; Xie, Ting; Zhang, Siman; Zheng, Zhenrong

    2017-09-01

    Light exerts non-visual effects on a wide range of biological functions and behavior apart from the visual effect. Light can regulate human circadian rhythms, like the secretion of melatonin and cortisol. Light also has influence on body's physiological parameters, such as blood pressure, heart rate and body temperature. However, human cognitive performance, alertness and mood under different lighting conditions have not been considered thoroughly especially for the complicated visual task like surgical operating procedure. In this paper, an experiment was conducted to investigate the cognition, alertness and mood of healthy participants in a simulated operating room (OR) in the hospital. A LED surgical lamp was used as the light source, which is mixed by three color LEDs (amber, green and blue). The surgical lamp is flexible on both spectrum and intensity. Exposed to different light settings, which are varied from color temperature and luminance, participants were asked to take psychomotor vigilance task (PVT) for alertness measurement, alphabet test for cognitive performance measurement, positive and negative affect schedule (PANAS) for mood measurement. The result showed the participants' cognitive performance, alertness and mood are related to the color temperature and luminance of the LED light. This research will have a guidance for the surgical lighting environment, which can not only enhance doctors' efficiency during the operations, but also create a positive and peaceful surgical lighting environment.

  13. Testing biological effects of hand-washing grey water for reuse in irrigation on an urban farm: a case study.

    Science.gov (United States)

    Khan, Mohammad Zain; Sim, Yei Lin; Lin, Yang Jian; Lai, Ka Man

    2013-01-01

    The feasibility of reusing hand-washing grey water contaminated with antibacterial hand-washing liquid for irrigation purposes in an urban farm is explored in this case study. Experiments are carried out to investigate if the quality of this grey water allows for its reuse in agriculture as per the guidelines established by the World Health Organization (WHO). However, there is no guideline to test the biological effect of grey water prior to agricultural use. It is plausible that the antibacterial property of the grey water can harm the soil microbial system and plants when applied to land, even if all other water quality parameters satisfy the WHO limit. We use algae (Chlorella vulgaris) and indigenous soil bacteria as initial plant and soil bacteria indicators, respectively, to test the potential inhibition of the water on plants and soil bacteria. Results show that the chemical oxygen demand (COD) of the grey water is 10% higher than the WHO permissible level, while all other water quality parameters are within the limits after four days of our experimental period. An inhibitory effect is observed in all of the biological tests. However, the inhibitory effect on algae and soil bacteria is not observed after the four-day period. The case study demonstrates a new approach for testing the biological effect of grey water, which can be used in conjunction with the WHO guideline, and provides data for this urban farm to set up a future water treatment system for grey-water reuse in irrigation.

  14. Biological and technological effects of some mulberry varieties and ...

    African Journals Online (AJOL)

    egyptian hak

    Rapid industrialization, increases in greenhouse gases in the atmosphere, ... entire agricultural production system through direct or indirect effects on crops, ... to India along with wheat grains under the PL 480 scheme from USA; it has .... water just before use; 1 N NaOH.0.5 grams fresh leaf material of Parthenium were.

  15. Effectiveness of a biological control agent Palexorista gilvoides in ...

    African Journals Online (AJOL)

    Widespread defoliation of plantation forests by insect pests causes economic losses worldwide. Successful pest outbreak management requires knowledge of effective pest management options. Currently, such knowledge is inadequate for Gonometa podocarpi an indigenous pest that has devastated conifer plantations in ...

  16. Biological and technological effects of some mulberry varieties and ...

    African Journals Online (AJOL)

    egyptian hak

    Maharashtra state of India. In order to manage this obnoxious weed in an ecologically safe and effective manner, therefore, we are searching for plants with an antagonistic potential via the mechanism of allelopathy. Here we evaluate the allelopathic potential of shoot leachates of selected plant species in order to assess ...

  17. Biological and technological effects of some mulberry varieties and ...

    African Journals Online (AJOL)

    egyptian hak

    However, 80% of these deaths occur in low-to-middle income countries of varying ... also involved in various cellular and subcellular functions, which include pro- ... substrate in most cells, this multifaceted amino acid is one of the principal free ..... Padma VV &Devi CS (2002) Effect of fish oil on mitochondrial respiration in ...

  18. Nanoscaled biological gated field effect transistors for cytogenetic analysis

    DEFF Research Database (Denmark)

    Kwasny, Dorota; Dimaki, Maria; Andersen, Karsten Brandt

    2014-01-01

    Cytogenetic analysis is the study of chromosome structure and function, and is often used in cancer diagnosis, as many chromosome abnormalities are linked to the onset of cancer. A novel label free detection method for chromosomal translocation analysis using nanoscaled field effect transistors...

  19. Linking exposure to environmental pollutants with biological effects

    DEFF Research Database (Denmark)

    Sørensen, Mette; Autrup, Herman; Møller, Peter

    2003-01-01

    Exposure to ambient air pollution has been associated with cancer. Ambient air contains a complex mixture of toxics, including particulate matter (PM) and benzene. Carcinogenic effects of PM may relate both to the content of PAH and to oxidative DNA damage generated by transition metals, benzene,...

  20. Biological Effects of Nonionizing Electromagnetic Radiation. Volume IV. Number 4.

    Science.gov (United States)

    1980-06-01

    absorbed power levels. The effect of EMR on CCAs will be evaluated using the following parameters: beat rate, maximum diastolic potential, action 0591...cerebral forma- superior olive were similar to those evoked by tions examined. The swelling of the cytoplasm was acoustic pulses presented binaurally at a