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Sample records for biological effects

  1. Biological effects

    International Nuclear Information System (INIS)

    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)

  2. Biological effects of radiation

    International Nuclear Information System (INIS)

    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

  3. 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.

  4. Quantum Effects in Biology

    Science.gov (United States)

    Mohseni, Masoud; Omar, Yasser; Engel, Gregory S.; Plenio, Martin B.

    2014-08-01

    List of contributors; Preface; Part I. Introduction: 1. Quantum biology: introduction Graham R. Fleming and Gregory D. Scholes; 2. Open quantum system approaches to biological systems Alireza Shabani, Masoud Mohseni, Seogjoo Jang, Akihito Ishizaki, Martin Plenio, Patrick Rebentrost, Alàn Aspuru-Guzik, Jianshu Cao, Seth Lloyd and Robert Silbey; 3. Generalized Förster resonance energy transfer Seogjoo Jang, Hoda Hossein-Nejad and Gregory D. Scholes; 4. Multidimensional electronic spectroscopy Tomáš Mančal; Part II. Quantum Effects in Bacterial Photosynthetic Energy Transfer: 5. Structure, function, and quantum dynamics of pigment protein complexes Ioan Kosztin and Klaus Schulten; 6. Direct observation of quantum coherence Gregory S. Engel; 7. Environment-assisted quantum transport Masoud Mohseni, Alàn Aspuru-Guzik, Patrick Rebentrost, Alireza Shabani, Seth Lloyd, Susana F. Huelga and Martin B. Plenio; Part III. Quantum Effects in Higher Organisms and Applications: 8. Excitation energy transfer in higher plants Elisabet Romero, Vladimir I. Novoderezhkin and Rienk van Grondelle; 9. Electron transfer in proteins Spiros S. Skourtis; 10. A chemical compass for bird navigation Ilia A. Solov'yov, Thorsten Ritz, Klaus Schulten and Peter J. Hore; 11. Quantum biology of retinal Klaus Schulten and Shigehiko Hayashi; 12. Quantum vibrational effects on sense of smell A. M. Stoneham, L. Turin, J. C. Brookes and A. P. Horsfield; 13. A perspective on possible manifestations of entanglement in biological systems Hans J. Briegel and Sandu Popescu; 14. Design and applications of bio-inspired quantum materials Mohan Sarovar, Dörthe M. Eisele and K. Birgitta Whaley; 15. Coherent excitons in carbon nanotubes Leonas Valkunas and Darius Abramavicius; Glossary; References; Index.

  5. Biological radiation effects

    International Nuclear Information System (INIS)

    The book covers all aspects of biological radiation effects and provides the fundamental basis for understanding the necessity of radiation protection as well as applications in radiotherapy. The physical basis is dealt with in some detail, and the effects at the subcellular and the cellular level are thoroughly 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). It can be used by graduate students as an introduction and as a source book for all who want to become acquainted with this important field. It is an extended version of the original German book containing updated information and new material. (orig.) With 273 figs

  6. Biological effects of neutrons

    International Nuclear Information System (INIS)

    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)

  7. Biological radiation effects

    International Nuclear Information System (INIS)

    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

  8. 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),...

  9. Biological radiation effects

    International Nuclear Information System (INIS)

    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

  10. Climatic and biological effects

    International Nuclear Information System (INIS)

    The ozone-climate problem has received considerable attention since concern was raised regarding possible threats to stratospheric ozone. Early climatic assessments of reduced ozone focused on the direct solar and longwave effects. Now a number of important feedback mechanisms are recognized as contributing significantly to indirect climatic effects. Although the focus in this chapter is on the climatic effect of reduced ozone, the discussion must include other trace gases as well. Many of the trace gases that interact photochemically to reduce ozone also have important radiative properties. Examples are chlorofluorocarbons (CFCl3 and CF2Cl2), nitrous oxide (N2O), and methane (CH4). Other gases, such as CO2, affect the temperature profile in the atmosphere, which can have an indirect effect on ozone through temperature-dependent reaction rates. The change in ozone, in turn, alters the change in temperature. The direct radiative effect of gases comes about through absorption of solar radiation and absorption and emission of longwave radiation (also referred to as thermal, terrestrial, or infrared radiation). The spectral distribution of solar and longwave radiation is shown. The principal gaseous absorbers of solar radiation are O2 and O3 in the stratosphere and H2O in the troposphere. As discussed in Chapter 2, ozone has absorption bands in the ultraviolet (uv) and visible regions of the solar spectrum. Water vapor absorbs primarily in the near-infrared spectral region

  11. Biological effects of inhaled radionuclides

    International Nuclear Information System (INIS)

    This report focuses on various types of radionuclides that may be inhaled and deposited in the respiratory tract. One of the primary goals of this ICRP Task Group is to assess specifically the biological implications of inhaled plutonium. Because other transuranics are becoming more abundant, information on americium, curium and einsteinium is included. Data are also included from studies of polonium and of several beta-gamma emitting isotopes. The Task Group evaluated most of the data on the biological effects of inhaled radionuclides in experimental animals to identify the tissues at risk and to assess possible dose-response relationships. Few data from human cases of inhaled radionuclides are available for this assessment. The biological effects of nonradioactive air pollutants were also considered to provide the perspective that all air pollutants can have a deleterious effect on human life and to emphasize the possibility for combined or synergistic effects of nonradioactive and radioactive substances on the respiratory tract. (orig./HP)

  12. Biological radiation effects

    International Nuclear Information System (INIS)

    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

  13. Biological effects of mutagenic agents

    International Nuclear Information System (INIS)

    There is an increasing body of evidence that mutagenic agents (biological, chemical and physical) play an important role in the etiology of human diseases. Mutations may occur in the germinal as well as in the somatic cells. Mutations of the germ cells may result on infertility or fertilization of damaged cells, the later leading to abortion or birth of a malformed fetus. Somatic-cells mutations may have various biological effects, depending on the period of the human life at which the mutation occurs. If it occurs during the prenatal life, a teratogenic or carcinogenic effect will be observed. If the somatic cell is damaged during the postnatal life, this will lead to neoplastic transformation. Therefore it is extremely important to know the mutagenic, teratogenic and carcinogenic effects of various biological, chemical and physical agents in order to eliminate them from our environment. (author). 13 refs, 4 figs, 1 tab

  14. 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.

  15. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    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)

  16. Quantum Effects in Biological Systems

    Science.gov (United States)

    Roy, Sisir

    2014-07-01

    The debates about the trivial and non-trivial effects in biological systems have drawn much attention during the last decade or so. What might these non-trivial sorts of quantum effects be? There is no consensus so far among the physicists and biologists regarding the meaning of "non-trivial quantum effects". However, there is no doubt about the implications of the challenging research into quantum effects relevant to biology such as coherent excitations of biomolecules and photosynthesis, quantum tunneling of protons, van der Waals forces, ultrafast dynamics through conical intersections, and phonon-assisted electron tunneling as the basis for our sense of smell, environment assisted transport of ions and entanglement in ion channels, role of quantum vacuum in consciousness. Several authors have discussed the non-trivial quantum effects and classified them into four broad categories: (a) Quantum life principle; (b) Quantum computing in the brain; (c) Quantum computing in genetics; and (d) Quantum consciousness. First, I will review the above developments. I will then discuss in detail the ion transport in the ion channel and the relevance of quantum theory in brain function. The ion transport in the ion channel plays a key role in information processing by the brain.

  17. Deuterium effects in cancer biology

    International Nuclear Information System (INIS)

    Since its discovery many experiments were conducted for explaining the effects of deuterium on biological systems. It was observed, in many studies, that by increasing the deuterium concentration, structural, metabolic and functional alterations at different extents are produced, which can lead to organism's death. On the other hand effects of concentration reduction are much less studied. Existing data in literature, with regard to intrinsic deuterium reduction effects on different carcinomas are rather scarce. In vitro studies of deuterium level reduction has evidenced an inhibiting effect upon the cellular proliferation in different tumoral cellular lines: M14 cellular lines (human melanoma), PC3 (prostate cancer) and MCF7 (breast cancer). In vivo researches made on experimental tumours, have shown that the deuterium level reduction determines partial or complete regressions in xenotransplanted tumours, while in veterinary oncological clinic, partial or total tumoral regression were observed in different spontaneous tumours in dogs and cats. (authors)

  18. Biological effects of electromagnetic fields

    International Nuclear Information System (INIS)

    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)

  19. Biological studies of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.H.

    1949-11-16

    This paper discusses procedures for research on biological effects of radiation, using mouse tissue: activation trace analysis including methods and proceedures for handling samples before during and after irradiation; methods and procedures for ion exchange study; method of separation and recovery of copper, iron, zinc, cobalt, pubidium and cesium. Also included are studies of trace elements with radioactive isotopes: the distribution of cobalt 60, zinc 65, and copper 64 in the cytoplasm and nuclei of normal mice and those with tumors. 16 figs., 2 tabs.

  20. Low level radiation: biological effects

    International Nuclear Information System (INIS)

    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

  1. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    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)

  2. Biological effect of fast neutrons

    International Nuclear Information System (INIS)

    The efficiency of fast neutrons of the energy range from 1.7 to 5 MeV in reducing the reticulocyte count and in diminishing the spleen weight was studied in male NMRI mice and compared with the effects of 250 kV X-rays. The neutron induced decrease of reticulocyte number in the peripheral blood is complete two days after irradiation. At this time even low doses cause a maximal effect. The relation between the rise of effect and the increase of exposure is great in the range of low doses and small in high doses. The relative biological effectiveness of neutrons in reducing the reticulocyte count is 2.5 after low doses and 1.2 after high doses. The spleen of irradiated mice shows a marked loss of weight, the lowest weight values are observed at the second day after irradiation. The relative effectiveness of neutrons in diminishing the spleen weight is 2.1 at low doses, the RBE decreases to 1.4 and rises again to 1.9 at higher doses. These results are compared with previous findings on mortality response and leucocyte and lymphocyte decrease in mice after neutron irradiation. Reticulocyte and lymphocyte count are found to be useful indicators for the detection and evaluation of neutron damage in the sublethal dose range. (orig.)

  3. Biological Effects after Prenatal Irradiation

    International Nuclear Information System (INIS)

    A Task Group of the International Commission on Radiological Protection (ICRP) has finished a report Biological Effects after Prenatal Irradiation (Embryo and Fetus) which has been approved by the Main Commission and Will be Published. Some new important scientific data shall be discussed in this contribution. During the preimplantation period lethality of the mammalian embryo is the dominating radiation effect. However, in mouse strains with genetic predispositions it has been shown that also malformations can be caused. This effect is genetically determined and its mechanisms is different from the induction of malformations during major organogenesis. Radiation exposures during this prenatal period leads ato an increase of genomic instability of cells in the normal appearing fetuses. These radiation effects can be transmitted to the next generation. A renewed analysis of individuals with severe mental retardation after exposures during the 8th to 15th week post conception in Hiroshima and Nagasaki gives evidence that a threshold dose exists for this effect around 300 mGy. This is supported by a number of experimental animal data which have been obtained from cellular and molecular investigations during the brain development. The data show the high radiosensitivity of the developing brain but also the various compensatory mechanisms and the enormous plasticity of these processes. The radiosensitivity varies strongly during the prenatal development. The highest sensitivity is found during the early and mid fetal period which is coinciding with weeks 8-15 post conception in humans. The lowest doses causing persistent damage are in the range of 100 to 300 mGy. For intelligence quotient scores a linear dose response model provides a satisfactory fit. From the experimental data it can be concluded that the fetal stage is most sensitive to the carcinogenic effect in comparison to the other prenatal stages. Such as clear situation cannot be obtained from the

  4. Biological effectiveness of fission neutrons

    International Nuclear Information System (INIS)

    Human peripheral blood lymphocytes were exposed to the uranium fission neutrons with different energy spectra, and the effects of changing pattern of energy spectrum on the relative biological effectiveness (RBE) were studied by analyzing dose-response relationship of chromosome aberrations. When the contribution of contaminated gamma-rays was subtracted, the efficiency of chromosomal response to the neutron dose was found to be refractory to the difference in the energy spectrum while the mean energy ranged from 2 MeV to 27 keV. This chromosomal refractoriness to energy spectrum may be explained by the similarity of energy spectrum for kerma contribution; most of the doses being given by neutrons with energy above 50 keV. Small doses given by short tracks may be less efficient. A comparison of these observations with chromosome aberration frequencies in lymphocytes of A-bomb survivors leads to somewhat higher estimate of neutron dose in Hiroshima than the estimate by the recently revised dosimetry system, DS86. (author)

  5. Biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    The efficient dose of ionizing radiation (I.R.), expressed in sievert is a weighting of the deposited energy (absorbed dose in grays) by factors that take into account the radiation hazard and tissues radiosensitivity. it is useful in radiation protection because it allows to add exposures to ionizing radiation of different nature. for low doses, it has no probabilistic value. The determinist effects of ionizing radiation are observed from thresholds of several hundred of milli sievert. The seriousness grows with the dose. The whole-body doses exceeding 8 Sv are always lethal. The radio-induced cancers are observed only for doses exceeding 100 to 200 mSv for adults, delivered at a self important dose rate. Their seriousness does not depend on the dose. Their appear fortuity (stochastic effect) with a various individual susceptibility, genetically determined. The number of eventual radio-induced cancers coming from the exposure of a high number of persons to low dose of ionizing radiation (<100 mSv) cannot be evaluated with a linear without threshold model. these models, however usually used, do not take into account the biological reality of cell defense mechanisms, tissues or whole body defense mechanisms, these one being different against low or high doses of ionizing radiation. Against low doses, the preponderant mechanism is the elimination of potentially dangerous damaged cells. Against high doses, the repair of damaged cells is imperative to preserve the tissue functions. It can lead to DNA repair errors (radio-induced mutations) and canceration. The radio-induced congenital malformations are effects with threshold. The radio-induced carcinogenesis in utero is a stochastic effect. The radio-induced hereditary congenital malformations have never been highlighted for man. (N.C.)

  6. 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...

  7. 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)

  8. Doses and biological effect of ionizing radiation

    International Nuclear Information System (INIS)

    Basic values and their symbols as well as units of physical dosimetry are given. The most important information about biological radiation effects is presented. Polish radiation protection standards are cited. (A.S.)

  9. Biological effect of radioprotectors. 2. Biological effect of aminothiol radioprotectors

    International Nuclear Information System (INIS)

    The section describes about radio-protective effects on cells and animals, and suppressive effects of mutagenesis and carcinogenesis of aminothiols. Amifostine, NH2-(CH2)3-NH-(CH2)2-SPO3H2 (WR-2721, prodrug), WR-1065 (amifostine-SH form, active principle of WR-2721) and WR-33278 (S-S oxidized form of WR-1065) are mainly discussed. In cells exposed in vitro to 4 mM WR-1065, their survival rates are usually elevated regardless of their types after radiation treatment. In vivo, the author employs the administration dose of 400 mg/kg, which is 2/3 LD50 of amifostine. The prodrug is less toxic than the active form in vivo and reduces the mortality by radiation. Amifostine is an FDA-registered medical for reduction of xerostomia during radiotherapy of head and neck cancer, and of renal toxicity of cisplatin during chemotherapy of advanced ovarian cancer. Hypoxanthine phosphoribosyl transferase (HPRT) mutagenic assay in vitro has revealed anti-mutagenic effect of WR-1065 at 40 M, and also in vivo, the effect is seen in mice after irradiation of X-ray and neutron beam at lower administration doses than that used for lethality test mentioned above. WR-2721 at 400 mg/kg and another aminothiol (WR-151327) have anti-caricinogenic effects in mice against lymphoreticular tumors induced by γ-ray or neutron beam and in rats, at 100 mg/kg WR-2721, against hepatoma development and at 50 mg/kg, against mammary cancer. The compounds are shown to suppress the tumor metastasis in animal models. In vitro, WR-1065 has been shown to reduce the frequency of cell transformation after X-ray or neutron exposure. (T.I.)

  10. Biological Effects of Ionizing Radiation

    International Nuclear Information System (INIS)

    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

  11. Biological effects of proton radiation: an update

    International Nuclear Information System (INIS)

    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)

  12. Biological Effects of Irradiated Fats

    International Nuclear Information System (INIS)

    Rats were fed with a diet containing 20% of irradiated oils. If the oils were irradiated with 2.5 Mrad, there was no indication of detrimental effects during the course of 80 weeks. Oils irradiated with 10 Mrad, however, caused an increase in lethality after a lag period of 9 to 12 months. Irradiation with 50 Mrad caused weight losses after 24 weeks, disturbed liver function, and hypoproteinaemia, with a relative increase in gamma globulins. No animal of this group exceeded a life-span of 75 weeks. Irradiation with 100 Mrad caused immediate toxic symptoms and a high lethality. There is no indication that peroxides are responsible for the toxicity of the irradiated oils. Because of the high content of dimeric products in the irradiated oils, it is assumed that dimerization of fatty acids is the cause of damage. (author)

  13. 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

  14. Biological effects of prenatal irradiation

    International Nuclear Information System (INIS)

    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)

  15. The biological effectiveness of antiproton irradiation

    DEFF Research Database (Denmark)

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

    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 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...

  16. Biological Effect of Magnetic Field in Mice

    Institute of Scientific and Technical Information of China (English)

    Zhao-Wei ZENG

    2005-01-01

    Objective: To study the biological effect of magnetic field in mice bodies. Method: With a piece of permanent magnet embeded in mice bodies beside the femoral artery and vein to measure the electrophoretic velocity(um/s). Result: The magnetic field in mice bodies on the experiment group that the electrophoretic velocity is faster more than control and free group.Conclusion:The magnetic field in animal's body can raise the negative electric charges on the surface of erythrocyte to improve the microcirculation, this is the biological effect of magnetic field.

  17. 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.

  18. Biological effectiveness of neutrons: Research needs

    International Nuclear Information System (INIS)

    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. RELATIVE BIOLOGICAL EFFECTIVENESS IN A PROTON SOBP

    Czech Academy of Sciences Publication Activity Database

    Vachelová, Jana; Michaelidesová, Anna; Litvinchuk, Alexandra; Vondráček, V.; Davídková, Marie

    Vol. 34. Bratislava : SMU - Faculty of Public Health, 2014. s. 121-121. ISBN 978-80-89384-08-2. [XXXVI.Dny radiační ochrany. 10.11.2014-14.11.2014, Poprad] Institutional support: RVO:61389005 Keywords : relative biological effectiveness * Spread-Out Bragg Peak * linear energy transfer Subject RIV: BO - Biophysics

  20. Biological radiation effects and radioprotection standards

    International Nuclear Information System (INIS)

    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

  1. Exploiting Allee effects for managing biological invasions

    Czech Academy of Sciences Publication Activity Database

    Tobin, P. C.; Berec, Luděk; Liebhold, A. M.

    2011-01-01

    Roč. 14, č. 6 (2011), s. 615-624. ISSN 1461-023X Grant ostatní: National Centre for Ecological Analysis and Synthesis(US) EF-0553768 Institutional research plan: CEZ:AV0Z50070508 Keywords : Allee dynamics * biological invasions * component Allee effect Subject RIV: EH - Ecology, Behaviour Impact factor: 17.557, year: 2011

  2. Nuclear energy: biological effects and environmental impact

    International Nuclear Information System (INIS)

    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

  3. II. Biological studies of radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Lawrence, J.H.

    1948-05-24

    With the completion of the 184 inch cyclotron in Berkeley and the successful construction of a deflector system, it was possible to bring the 190 Mev deuteron and the 380 Mev alpha beams out into the air and to begin a study of the effects of high-energy deuteron beams by direct irradiation of biological specimens. The direct biological use of deuteron beams was attempted earlier in Berkeley by Marshak, MacLeish, and Walker in 1940. These and other investigators have been aware for some time of the potential usefulness of high energy particle beams for radio-biological studies and their suitability for biological investigations. R.R. Wilson advanced the idea of using fast proton beams to deliver radiation and intervening tissues. R.E. Zirkle pointed out that such particle beams may be focused or screened until a cross-section of the beam is small enough to study effects of irradiation under the microscope on single cells or on parts of single cells. This article gives an overview of the radiological use of high energy deuteron beams, including the following topics: potential uses of high energy particle beams; experiments on the physical properties of the beam; lethal effect of the deuteron beam on mice.

  4. 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 electromagnetic radiation are known to affect animals and 10-20% of the human population. There is now evidence for mechanisms such as calcium flux, melatonin disruption, magnetite and cryptochromes. Both environmental and receptor variations explain confounding factors and inconsistencies in the evidence. Electromagnetic effects might also account for some evolutionary changes. Further research on lunar biological effects, such as acute myocardial infarction, could help the development of strategies to reduce adverse effects for people sensitive to geomagnetic disturbance. PMID:26462435

  5. Mechanistic Effects of Calcitriol in Cancer Biology

    Directory of Open Access Journals (Sweden)

    Lorenza Díaz

    2015-06-01

    Full Text Available Besides its classical biological effects on calcium and phosphorus homeostasis, calcitriol, the active vitamin D metabolite, has a broad variety of actions including anticancer effects that are mediated either transcriptionally and/or via non-genomic pathways. In the context of cancer, calcitriol regulates the cell cycle, induces apoptosis, promotes cell differentiation and acts as anti-inflammatory factor within the tumor microenvironment. In this review, we address the different mechanisms of action involved in the antineoplastic effects of calcitriol.

  6. THz waves: biological effects, industrial and medical

    International Nuclear Information System (INIS)

    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.)

  7. 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.

  8. Biological effect of low dose radiation

    International Nuclear Information System (INIS)

    This document describes the recent findings in studies of low dose radiation effect with those by authors' group. The low dose radiation must be considered in assessment of radiation effects because it induces the biological influence unexpected hitherto; i.e., the bystander effect and genetic instability. The former is a non-targeted effect that non-irradiated cells undergo the influence of directly irradiated cells nearby, which involves cell death, chromosome aberration, micronucleus formation, mutation and carcinogenesis through cellular gap junction and/or by signal factors released. Authors' group has found the radical(s) possessing as long life time as >20 hr released from the targeted cells, a possible mediator of the effect; the generation of aneuploid cells as an early carcinogenetic change; and at dose level <10 Gy, activation of MAPK signal pathway leading to relaxation of chromatin structure. The genetic instability means the loss of stability where replication and conservation of genome are normally maintained, and is also a cause of the late radiation effect. The group has revealed that active oxygen molecules can affect the late effect like delayed cell death, giant cell formation and chromosome aberration, all of which lead to the instability, and is investigating the hypothesis that the telomere instability resulted from the abnormal post-exposure interaction with its nuclear membrane or between chromatin and nuclear matrix, is enhanced by structural distortion of nuclear genes. As well, shown is the possible suppression of carcinogenesis by p53. The group, to elucidate the mechanism underlying the low dose radiation effect, is conducting their studies in consideration of the sequential bases of physical, chemical and biological processes. (R.T.)

  9. Biological Effects of Yeast β-Glucans

    Directory of Open Access Journals (Sweden)

    Vlatka Petravić-tominac

    2010-12-01

    Full Text Available β-Glucans are glucose polymers that naturally occur in yeasts, molds, algae, mushrooms, bacteria, oats and barley. Immunostimulation is one of the most important properties of β-glucans. They are classified as biological response modifiers and because of their biological activities they can be used in human and veterinary medicine and pharmacy. Additionally, β-glucans show interesting physicochemical properties and therefore could be applied in food and feed production as well as in cosmetic and chemical industries. Immunomodulation by β-glucan, both in vitro and in vivo, inhibits cancer cell growth and metastasis and prevents or reduces bacterial infection. In humans, dietary β-glucan lowers blood cholesterol, improves glucose utilization by body cells and also helps wound healing. β-Glucans work, in part, by stimulating the innate immune mechanism to fight a range of foreign challenges and could be used as an adjuvant, in combination with anti infective or antineoplastic agents, radiotherapy, and a range of topical agents and nutrients. The structure of β-glucans depends on the source they are isolated from. Native β-glucan molecules can be linked and branched in several ways. Biological properties of different β-glucan molecules are dependent on their molecular structure. Some authors claim that the β-(1→3, (1→6-glucan derived from yeast Saccharomyces cerevisiae produce the highest biological effects. Thus, in this review the β-glucans and their metabolic activity are discussed, with the special accent on those isolated from yeast. Other possible β-glucan applications, directed to cosmetic production, non-medical application in pharmaceutical and chemical industry, are also discussed.

  10. Effects of Pesticides on Biological Systems

    Directory of Open Access Journals (Sweden)

    Ergul Belge Kurutas

    2003-06-01

    Full Text Available The use of pesticid both in Turkey and other contries is widespread in order to combat against many pests which cause economical damages. However, pesticides in human pass through skin, respiratory or digestive systems and is metabolized by monooxygenase system dependent upon cytocrome P450 in liver. They also give rise to severe decreases cytochrome P450 and amount of "hem" enzyme activites of glucose-6-phosphatase, pyrophosphatase by stimulating lipid peroxidation on hepatic microsomes. In this study effects of pesticides on biological systems will be presented in genaral terms. [Archives Medical Review Journal 2003; 12(3.000: 215-228

  11. Biological effects of synchrotron radiation on crops

    Institute of Scientific and Technical Information of China (English)

    唐掌雄; 董保中; 等

    1996-01-01

    The sensitivity of germinating seeds of barley,winter wheat and spring one to synchrotron ultraviolet radiation is barley>winter wheat and spring one.But when dry seeds of the three crops are irradiated by 3.5-22keV X-rays,the sequence of their sensitivity to radiation can be changed.for irradiation of 0.6-3keV ultra soft X-rays,0.40-0.90 of the seedlings of the first generation appear mutation of striped chlorophyll defect.This biological effect has never been found for irradiation of other rays.

  12. 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.

  13. Ionizing radiation effects on biological macromolecules

    International Nuclear Information System (INIS)

    Ionizing radiation is one of the main environmental factors for life, particularly for human beings. The primary effects of ionizing radiation produce the perturbation of biomacromolecules functionality (DNA and proteins). This effect occurs by direct action and by the indirect way of water molecules radiolysis. These primary effects result in a cascade of biochemical and biological consequences that may finally influence the general functions of the organism. In the last five decades the research activity in this field was focused on the detailed description of the effects on DNA molecules and their biochemical and biological consequences. The reason for this is the importance of the integrity of DNA for the cell life evolution, especially for the cell recovery processes or for the programmed cell death after irradiation. These aspects have main applications in very important fields as radioprotection and radiotherapy. In the present paper the mechanisms of ionizing radiation action at the molecular level will be reviewed, with focus on the protein level effects. Although comparatively a lower number of results was reported concerning the effects of ionizing radiation on the proteins, during the last years this field was reconsidered in the context of a new research trend in the field of genomics and proteomics. The structural changes which occur most often in the proteins are the breaks of chemical links, the chemical moieties ionization (for instance, the oxidation of the proteins) and the inter - protein new links (cross-linking). These changes result in a gradual loss of protein functionality, influencing particularly the ionic transport, the signal transduction across the membrane or intermolecular recognition processes of antibody-antigen type. Some studies on the ion artificial channels (as gramicidin and amphotericin) incorporated in model membranes (BLM-s or liposomes) describe structural and functional changes of the peptides after the exposure to

  14. The biological effects of ozone depletion.

    Science.gov (United States)

    Young, A R

    1997-05-01

    Thinning of the ozone layer is predicted to result in increased levels of ultraviolet (UV) B radiation at the earth's surface. This effect has been confirmed by measurements made in relatively unpolluted areas such as Antarctica, the southern part of South America and at mid-to-high latitudes in the northern hemisphere. It has been harder to show in populated northern latitudes because of a number of confounding factors, notably weather systems and low level ozone pollution. Although UVB forms only a small proportion of the UV spectrum it has potent biological effects so that a small increase in penetration of UVB to the earth's surface has profound effects on a wide range of life forms. Most attention has been paid to the effects of an increase in UVB on human health, particularly the effects on skin cancer, resistance to infectious diseases and cataract formation. However, the effects of increased levels of UVB on other parts of the ecosystem, particularly on the primary producers in aquatic and terrestrial food chains, may be of even. PMID:9519507

  15. Biological radiation effects of Radon in Drosophila

    International Nuclear Information System (INIS)

    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/m3 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/m3, 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)

  16. Biological Effects of Yeast β-Glucans

    Directory of Open Access Journals (Sweden)

    Vlatka Petravić-Tominac

    2014-02-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0pt 5.4pt 0pt 5.4pt; mso-para-margin:0pt; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} β-Glucans are glucose polymers that naturally occur in yeasts, molds, algae, mushrooms, bacteria, oats and barley. Immunostimulation is one of the most important properties of β-glucans. They are classified as biological response modifiers and because of their biological activities they can be used in human and veterinary medicine and pharmacy. Additionally, β-glucans show interesting physicochemical properties and therefore could be applied in food and feed production as well as in cosmetic and chemical industries. Immunomodulation by β-glucan, both in vitro and in vivo, inhibits cancer cell growth and metastasis and prevents or reduces bacterial infection. In humans, dietary β-glucan lowers blood cholesterol, improves glucose utilization by body cells and also helps wound healing. β-Glucans work, in part, by stimulating the innate immune mechanism to fight a range of foreign challenges and could be used as an adjuvant, in combination with anti infective or antineoplastic agents, radiotherapy, and a range of topical agents and nutrients. The structure of β-glucans depends on the source they are isolated from. Native β-glucan molecules can be linked and branched in several ways. Biological properties of different β-glucan molecules are dependent on their molecular structure. Some authors claim that the β-(1→3, (1→6-glucan derived from yeast Saccharomyces cerevisiae produce the highest biological effects. Thus, in this review the β-glucans and their metabolic

  17. Biological effects of space radiation and development of effective countermeasures

    Science.gov (United States)

    Kennedy, Ann R.

    2014-04-01

    As part of a program to assess the adverse biological effects expected from astronauts' exposure to space radiation, numerous different biological effects relating to astronauts' health have been evaluated. There has been major focus recently on the assessment of risks related to exposure to solar particle event (SPE) radiation. The effects related to various types of space radiation exposure that have been evaluated are: gene expression changes (primarily associated with programmed cell death and extracellular matrix (ECM) remodeling), oxidative stress, gastrointestinal tract bacterial translocation and immune system activation, peripheral hematopoietic cell counts, emesis, blood coagulation, skin, behavior/fatigue (including social exploration, submaximal exercise treadmill and spontaneous locomotor activity), heart functions, alterations in biological endpoints related to astronauts' vision problems (lumbar puncture/intracranial pressure, ocular ultrasound and histopathology studies), and survival, as well as long-term effects such as cancer and cataract development. A number of different countermeasures have been identified that can potentially mitigate or prevent the adverse biological effects resulting from exposure to space radiation.

  18. Biological effects of progestins in breast cancer.

    Science.gov (United States)

    Pasqualini, J R; Ebert, C; Chetrite, G S

    2001-12-01

    The action of progestins is derived from many factors: structure, affinity for the progesterone receptor or for other steroid receptors, the target tissue considered, the biological response, the experimental conditions, the dose and metabolic transformation. The proliferative response to progestins in human breast cancer cells is contradictory: some progestins inhibit, others stimulate, have no effect at all, or have a dual action. For instance, medroxyprogesterone acetate has a stimulatory effect on breast cancer cells after a short period of treatment, but this effect becomes inhibitory when treatment is prolonged. It has been demonstrated that, in hormone-dependent breast cancer cells, various progestins (nomegestrol acetate, medrogestone, promegestone) are potent sulfatase inhibitory agents. The progestins can also involve the inhibition of the mRNA expression of this enzyme. In another series of studies it was also demonstrated that some progestins are very active in inhibiting 17beta-hydroxysteroid dehydrogenase for the conversion of estrone to estradiol. More recently it was observed that the progestins promegestone and medrogestone stimulate sulfotransferase for the formation of estrogen sulfates. Consequently, the action of progestins in blocking estradiol formation via sulfatase, or in stimulating the effect on sulfotransferase activity, can open interesting and new possibilities in clinical applications in breast cancer. PMID:12227886

  19. Microwave radiation: biological effects and exposure standards

    Energy Technology Data Exchange (ETDEWEB)

    Lindsay, I.R.

    1981-01-01

    The thermal effects of microwave radiation are well recognized and are discussed with particular reference to cataractogenesis; the possibility of an association cannot be questioned. Postulated nonthermal effects comprise an asthenic syndrome, and for the most part the disturbances lie within clinical norms and tolerances, and are reversible. World opinion on safe exposure levels for microwave radiation is varied, and this had led to national standards disparate by three to four orders of magnitude. The US and UK exposure standard of 10 mW/cm/sup 2/ was determined over two decades ago; the possibility of a change to a more restrictive level, in line with other countries, in the near future is examined. It is concluded that such a change, without scientific rationale, is not justified. Some biological implications of the microwave radiation from the solar power satellite are considered in terms of precautions to be taken by personnel working in the vicinity of the rectenna, effects on cardiac pacemakers, and any potential effects on birds. 14 references.

  20. Contrast media: Biologic effects and clinical application

    International Nuclear Information System (INIS)

    An overview is presented of the recent developments in contrast media and their clinical applications, plus the current state-of-the-art in computerized tomography, digital subtraction angiography, ultrasound and magnetic resonance imaging (MRI). Contents of these volumes include: an in-depth review of the historical development, modern perspectives in structure-function relationships, biologic effects on hemostats, gastrointestinal, cardiovascular systems and drug interactions. Critical and basic issues, including cellular toxicity, mutagenesis, synergism between radiation and contrast agents, mechanisms in contrast-induced reactions, and the management of such reactions in high-risk patients are also presented. Specific applications of paramagnetic compounds in MRI and the recent concept of liposome-encapsulated and particulate suspension of contrast materials in diagnostic imaging are thoroughly discussed

  1. Contrast media: Biologic effects and clinical application

    Energy Technology Data Exchange (ETDEWEB)

    Parvez, Z.; Moncada, R.; Sovak, M.

    1987-01-01

    An overview is presented of the recent developments in contrast media and their clinical applications, plus the current state-of-the-art in computerized tomography, digital subtraction angiography, ultrasound and magnetic resonance imaging (MRI). Contents of these volumes include: an in-depth review of the historical development, modern perspectives in structure-function relationships, biologic effects on hemostats, gastrointestinal, cardiovascular systems and drug interactions. Critical and basic issues, including cellular toxicity, mutagenesis, synergism between radiation and contrast agents, mechanisms in contrast-induced reactions, and the management of such reactions in high-risk patients are also presented. Specific applications of paramagnetic compounds in MRI and the recent concept of liposome-encapsulated and particulate suspension of contrast materials in diagnostic imaging are thoroughly discussed.

  2. Biological effects of deuterium - depleted water

    International Nuclear Information System (INIS)

    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)

  3. Food irradiation and its biological effects

    International Nuclear Information System (INIS)

    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)

  4. Biological effects of radon in Drosophila

    International Nuclear Information System (INIS)

    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)

  5. Dosimetry and biological effects of fast neutrons

    International Nuclear Information System (INIS)

    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.)

  6. E. Biological effects of radiation on man

    International Nuclear Information System (INIS)

    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

  7. What Makes Biology Learning Difficult and Effective: Students' Views

    Science.gov (United States)

    Cimer, Atilla

    2012-01-01

    The present study aims to determine the biological topics that students have difficulties learning, the reasons why secondary school students have difficulties in learning biology, and ways to improve the effectiveness of students' biology learning. For these purposes, a self-administered questionnaire including three open-ended questions was…

  8. The late biological effects of ionizing radiation

    International Nuclear Information System (INIS)

    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

  9. Accounting for biological effectiveness in radiological protection

    International Nuclear Information System (INIS)

    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)

  10. 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

  11. 2.3.1 Biological Effects of Ionizing Radiations

    Science.gov (United States)

    Kaul, A.

    This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Subsection '2.3.1 Biological Effects of Ionizing Radiations' of the Section '2.3 Biological Effects' of the Chapter '2 Radiation and Biological Effects' with the comtents:

  12. SIX2 Effects on Wilms Tumor Biology

    Directory of Open Access Journals (Sweden)

    Janene Pierce

    2014-12-01

    Full Text Available Wilms tumor (WT blastema retains gene expression profiles characteristic of the multipotent nephron progenitor pool, or cap mesenchyme (CM, in the developing kidney. As a result, WT blastema and the CM are believed to represent contextual analogues of one another. Sine oculis homeobox 2 (SIX2 is a transcription factor expressed specifically in the CM, provides a critical mechanism for CM self-renewal, and remains persistently active in WT blastema, although its purpose in this childhood malignancy remains unclear. We hypothesized that SIX2, analogous to its function in development, confers a survival pathway to blastema, the putative WT stem cell. To test its functional significance in WT biology, wild-type SIX2 was overexpressed in the human WT cell line, WiT49. After validating this model, SIX2 effects on anchorage-independent growth, proliferation, invasiveness, canonical WNT pathway signaling, and gene expression of specific WNT pathway participants were evaluated. Relative to controls, WiT49 cells overexpressing SIX2 showed significantly enhanced anchorage-independent growth and early-passage proliferation representing surrogates of cell survival. Interestingly, overexpression of SIX2 generally repressed TCF/LEF-dependent canonical WNT signaling, which activates and coordinates both differentiation and stem pathways, but significantly heightened canonical WNT signaling through the survivin promoter, a mechanism that exclusively maintains the stem state. In summary, when overexpressed in a human WT cell line, SIX2 enhances cell survival and appears to shift the balance in WNT/β-catenin signaling away from a differentiation path and toward a stem cell survival path.

  13. Biological effects of low-dose ionizing radiation exposure

    International Nuclear Information System (INIS)

    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.

  14. Biological effects of anthropogenic contaminants in the San Francisco Estuary

    Science.gov (United States)

    Thompson, B.; Adelsbach, T.; Brown, C.; Hunt, J.; Kuwabara, J.; Neale, J.; Ohlendorf, H.; Schwarzbach, S.; Spies, R.; Taberski, K.

    2007-01-01

    Concentrations of many anthropogenic contaminants in the San Francisco Estuary exist at levels that have been associated with biological effects elsewhere, so there is a potential for them to cause biological effects in the Estuary. The purpose of this paper is to summarize information about biological effects on the Estuary's plankton, benthos, fish, birds, and mammals, gathered since the early 1990s, focusing on key accomplishments. These studies have been conducted at all levels of biological organization (sub-cellular through communities), but have included only a small fraction of the organisms and contaminants of concern in the region. The studies summarized provide a body of evidence that some contaminants are causing biological impacts in some biological resources in the Estuary. However, no general patterns of effects were apparent in space and time, and no single contaminant was consistently related to effects among the biota considered. These conclusions reflect the difficulty in demonstrating biological effects due specifically to contamination because there is a wide range of sensitivity to contaminants among the Estuary's many organisms. Additionally, the spatial and temporal distribution of contamination in the Estuary is highly variable, and levels of contamination covary with other environmental factors, such as freshwater inflow or sediment-type. Federal and State regulatory agencies desire to develop biological criteria to protect the Estuary's biological resources. Future studies of biological effects in San Francisco Estuary should focus on the development of meaningful indicators of biological effects, and on key organism and contaminants of concern in long-term, multifaceted studies that include laboratory and field experiments to determine cause and effect to adequately inform management and regulatory decisions. ?? 2006 Elsevier Inc. All rights reserved.

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

    International Nuclear Information System (INIS)

    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. Ion irradiation and the biological effect of immune system

    International Nuclear Information System (INIS)

    Ion irradiation exists broadly in the people's life. It can induce a series of the biological effect in body depending on the different type and dose of ionization. This article expound the effect of ion irradiation on the biological function of immune system, affording the theorial guide in the appreciation, precaution and treatment of irradiation injury. (authors)

  17. Technology Rich Biology Labs: Effects of Misconceptions.

    Science.gov (United States)

    Kuech, Robert; Zogg, Gregory; Zeeman, Stephan; Johnson, Mark

    This paper describes a study conducted on the lab sections of the general biology course for non-science majors at the University of New England, and reports findings of student misconceptions about photosynthesis and the mass/carbon uptake during plant growth. The current study placed high technology analytic tools in the hands of introductory…

  18. Evolutionary Tradeoffs between Economy and Effectiveness in Biological Homeostasis Systems

    OpenAIRE

    Pablo Szekely; Hila Sheftel; Avi Mayo; Uri Alon

    2013-01-01

    Biological regulatory systems face a fundamental tradeoff: they must be effective but at the same time also economical. For example, regulatory systems that are designed to repair damage must be effective in reducing damage, but economical in not making too many repair proteins because making excessive proteins carries a fitness cost to the cell, called protein burden. In order to see how biological systems compromise between the two tasks of effectiveness and economy, we applied an approach ...

  19. Non-Thermal Effects Mobile Phones at Biological Objects

    OpenAIRE

    Ladislav Balogh

    2003-01-01

    The article deals with non-thermal effects of mobile phones on biological objects. Even though these effects are observed for longer period, there are not so far unequivocal results on obtained biological and biophysical results in this field. Biologicaleffects of electromagnetic field (EMF) depend on its character, its duration as well as on features of organism. As the receptors offield are not known (e.g. inputs of EMF into organism), its effects are judged only by non-specific reaction of...

  20. Topical Day on Biological Effects of Radiation

    International Nuclear Information System (INIS)

    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

  1. 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.

  2. SWEET CORN CULTIVAR INFLUENCES BIOLOGICALLY EFFECTIVE HERBICIDE DOSE [ABSTRACT

    Science.gov (United States)

    Competitive crop cultivars are considered a component of integrated weed management systems; however specific knowledge of interactions among crop cultivars and other management tactics, such as biologically effective herbicide dose, is limited. Observed variation in crop tolerance and weed supp...

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

    International Nuclear Information System (INIS)

    Biological effect of the 192Ir high activity source on LA795 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 LA795 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

  4. Biological Effects of the Great Oxidation Event

    Science.gov (United States)

    Schopf, J.

    2012-12-01

    Fossil evidence of photoautotrophy, documented in Precambrian sediments by stromatolites, stromatolitic microfossils, and carbon isotopic data consistent with autotrophic CO2-fixation, extends to ~3,500 Ma. Such data, however, are insufficient to establish the time of origin of O2-producing (cyanobacterial) photosynthesis from its anoxygenic, photosynthetic bacterial, evolutionary precursor. The oldest (Paleoarchean) stromatolites may have been formed by anoxygenic photoautotrophs, rather than the cyanobacteria that dominate Proterozoic and modern stromatolites. Unlike the cyanobacteria of Proterozoic microbial assemblages, the filamentous and coccoidal microfossils of Archean deposits may represent remnants of non-O2-producing prokaryotes. And although the chemistry of Archean organic matter shows it to be biogenic, its carbon isotopic composition is insufficient to differentiate between oxygenic and anoxygenic sources. Though it is well established that Earth's ecosystem has been based on autotrophy since its early stages and that O2-producing photosynthesis evolved earlier, perhaps much earlier, than the increase of atmospheric oxygen in the ~2,450 and ~2,320 Ma Great Oxidation Event (GOE), the time of origin of oxygenic photoautotrophy has yet to be established. Recent findings suggest that Earth's ecosystem responded more or less immediately to the GOE. The increase of atmospheric oxygen markedly affected ocean water chemistry, most notably by increasing the availability of biologically usable oxygen (which enabled the development of obligate aerobes, such as eukaryotes), and of nitrate, sulfate and hydrogen sulfide (the increase of H2S being a result of microbial reduction of sulfate), the three reactants that power the anaerobic basis of sulfur-cycling microbial sulfuretums. Fossil evidence of the earliest eukaryotes (widely accepted to date from ~1800 Ma and, arguably, ~2200 Ma) fit this scenario, but the most telling example of life's response to the GOE

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

    International Nuclear Information System (INIS)

    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)

  6. Biological effects at low irradiation doses

    International Nuclear Information System (INIS)

    Full text: The best scientific evidence of radiation effects in humans initially came from epidemiological studies of atomic bomb survivors in Hiroshima and Nagasaki. While no evidence of genetic effects has been found, these studies showed a roughly linear relationship between the induction of cancer and extremely high dose-rate of atomic bomb radiation. This was consistent with the knowledge that ionizing radiation can damage DNA in linear proportion to high-dose exposures and so produces gene mutations known to be associated with cancer. In the absence of comparable low dose effects it was prudent to propose tentatively the no-threshold hypothesis (LNT) that extrapolates linearly from effects observed at very high doses to the same effects at very low doses. It was accepted by the International Commission on Radiological Protection (ICRP) and afterwards adopted by national radiation protection organizations to guide regulations for the protection of occupationally exposed workers and the public. This hypothesis that all radiation is harmful in linear proportion to the dose is the principle used for collective dose calculations of the number of deaths produced by any radiation, natural of generated, no matter how small (BEIR-2000). The National Council of Radiation Protection and Measurements Report 121, summarizes the basis for adherence to linearity of radiation health effects. Confidence in LNT at low doses is based on our understanding of the basic mechanisms involved. Genetic effects may result from a gene mutation or a chromosome aberration. The activation of a dominant acting oncogene is frequently associated with leukemia and lymphomas, while the loss of suppressor genes appears to be more frequently associated with solid tumors. It is conceptually possible, but with a vanishing small probability, that any of these effects could result from the passage of a single charged particle, causing damage to DNA that could be expressed as a mutation or small

  7. Biological effects and hazards of radiation exposure

    International Nuclear Information System (INIS)

    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 106 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

  8. Titanium dioxide nanoparticles – Biological effects

    OpenAIRE

    Anna Maria Świdwińska-Gajewska; Sławomir Czerczak

    2014-01-01

    Titanium dioxide occurs as particles of various sizes. Particles of up to 100 nm, corresponding to nanoparticles, and in the size range of 0.1–3 mm are the most frequently used. Titanium dioxide in a bulk form is not classified as dangerous substance, nevertheless nanoparticles may cause adverse health effects. Inhalation exposure to nano-TiO2 causes pulmonary inflammation that may lead to fibrotic and proliferative changes in the lungs. Many studies confirm the genotoxic effect of TiO2, espe...

  9. Biological Effects of Neutron and Proton Irradiations. Vol. I. Proceedings of the Symposium on Biological Effects of Neutron Irradiations

    International Nuclear Information System (INIS)

    During recent years the interest in biological effects caused by neutrons has been increasing steadily as a result of the rapid development of neutron technology and the great number of neutron sources being used. Neutrons, because of their specific physical characteristics and biological effects, form a special type of radiation hazard but, at the same time, are a prospective tool for applied radiobiology. This Symposium, held in Brookhaven at the invitation of the United States Government from 7-11 October 1963, provided an opportunity for scientists to discuss the experimental information at present available on the biological action of neutrons and to evaluate future possibilities. It was a sequel to the Symposium on Neutron Detection, Dosimetry and Standardization, which was organized by the International Atomic Energy Agency in December 1962 at Harwell. The Symposium was attended by 128 participants from 17 countries and 6 international organizations. Fifty-four papers were presented. The following subjects were discussed in various sessions: (1) Dosimetry. Estimation of absorbed dose of neutrons in biological material. (2) Biological effects of high-energy protons. (3) Cellular and genetic effects. (4) Pathology of neutron irradiation, including acute and chronic radiation syndromes (mortality, anatomical and histological changes, biochemical and metabolic disturbances) and delayed consequences. (5) Relative biological effectiveness of neutrons evaluated by different biological tests. A Panel on Biophysical Considerations in Neutron Experimentation, with special emphasis on informal discussions, was organized during the Symposium. The views of the Panel are recorded in Volume II of the Proceedings. Many reports were presented on the important subject of the relative effectiveness of the biological action of neutrons, as well as on the general pathology of neutron irradiation and the cellular and genetic effects related to it. Three survey papers considered

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

    International Nuclear Information System (INIS)

    During recent years the interest in biological effects caused by neutrons has been increasing steadily as a result of the rapid development of neutron technology and the great number of neutron sources being used. Neutrons, because of their specific physical characteristics and biological effects, form a special type of radiation hazard but, at the same time, are a prospective tool for applied radiobiology. This Symposium, held in Brookhaven at the invitation of the United States Government from 7-11 October 1963, provided an opportunity for scientists to discuss the experimental information at present available on the biological action of neutrons and to evaluate future possibilities. It was a sequel to the Symposium on Neutron Detection, Dosimetry and Standardization, which was organized by the International Atomic Energy Agency in December 1962 at Harwell. The Symposium was attended by 128 participants from 17 countries and 6 international organizations. Fifty-four papers were presented. The following subjects were discussed in various sessions: (1) Dosimetry. Estimation of absorbed dose of neutrons in biological material. (2) Biological effects of high-energy protons. (3) Cellular and genetic effects. (4) Pathology of neutron irradiation, including acute and chronic radiation syndromes (mortality, anatomical and histological changes, biochemical and metabolic disturbances) and delayed consequences. (5) Relative biological effectiveness of neutrons evaluated by different biological tests. A Panel on Biophysical Considerations in Neutron Experimentation, with special emphasis on informal discussions, was organized during the Symposium. The views of the Panel are recorded in Volume II of the Proceedings. Many reports were presented on the important subject of the relative effectiveness of the biological action of neutrons, as well as on the general pathology of neutron irradiation and the cellular and genetic effects related to it. Three survey papers considered

  11. Predictive modeling of nanomaterial exposure effects in biological systems

    OpenAIRE

    Liu X; Tang K.; Harper S.; Harper B; Steevens JA; Xu R

    2013-01-01

    Xiong Liu,1 Kaizhi Tang,1 Stacey Harper,2 Bryan Harper,2 Jeffery A Steevens,3 Roger Xu1 1Intelligent Automation, Inc., Rockville, MD, USA; 2Department of Environmental and Molecular Toxicology, School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR, USA; 3ERDC Environmental Laboratory, Vicksburg, MS, USA Background: Predictive modeling of the biological effects of nanomaterials is critical for industry and policymakers to assess the potential ha...

  12. Biological and therapeutical effects of Radon

    Energy Technology Data Exchange (ETDEWEB)

    Deetjen, P. [Institute of Physiologie and Balneologie, University of Innsbruck (Austria)

    1998-12-31

    In spas with a somewhat elevated Radon{sup 222} (Rn) activity (between 300 and 3000 Bq/l), the empirical medicine ended - in all parts of the world - with the same list of indications. It mainly includes the more painful rheumatic diseases such as deformation or degeneration of the joints and non bacterial inflammation of muscles, tendons or joints; Morbus Bechterew and other diseases of the vertebral column like spondylosis, spondylarthrosis or osteochondrosis. While informer times these effects were seldom documented in an objective manner, in recent years several prospective randomized double-blind studies proved the pain reducing efficacy of Radon therapy in patients with cervical pain syndromes, with chronic polyarthritis or with Morbus Bechterew. Studies in experimental animal models have accumulated remarkable data in organs, tissue and cultured cells that provide a rationale to explain the observed effects of Radon therapy in patients. (author)

  13. Biological and therapeutical effects of Radon

    International Nuclear Information System (INIS)

    In spas with a somewhat elevated Radon222 (Rn) activity (between 300 and 3000 Bq/l), the empirical medicine ended - in all parts of the world - with the same list of indications. It mainly includes the more painful rheumatic diseases such as deformation or degeneration of the joints and non bacterial inflammation of muscles, tendons or joints; Morbus Bechterew and other diseases of the vertebral column like spondylosis, spondylarthrosis or osteochondrosis. While informer times these effects were seldom documented in an objective manner, in recent years several prospective randomized double-blind studies proved the pain reducing efficacy of Radon therapy in patients with cervical pain syndromes, with chronic polyarthritis or with Morbus Bechterew. Studies in experimental animal models have accumulated remarkable data in organs, tissue and cultured cells that provide a rationale to explain the observed effects of Radon therapy in patients. (author)

  14. Biological Effects of Low Level Laser Therapy

    OpenAIRE

    Farivar, Shirin; Malekshahabi, Talieh; Shiari, Reza

    2014-01-01

    The use of low level laser to reduce pain, inflammation and edema, to promote wound, deeper tissues and nerves healing, and to prevent tissue damage has been known for almost forty years since the invention of lasers. This review will cover some of the proposed cellular mechanisms responsible for the effect of visible light on mammalian cells, including cytochrome c oxidase (with absorption peaks in the Near Infrared (NIR)). Mitochondria are thought to be a likely site for the initia...

  15. Palytoxin and Analogs: Biological and Ecological Effects

    Directory of Open Access Journals (Sweden)

    Vítor Ramos

    2010-06-01

    Full Text Available Palytoxin (PTX is a potent marine toxin that was originally found in soft corals from tropical areas of the Pacific Ocean. Soon after, its occurrence was observed in numerous other marine organisms from the same ecological region. More recently, several analogs of PTX were discovered, remarkably all from species of the dinoflagellate genus Ostreopsis. Since these dinoflagellates are also found in other tropical and even in temperate regions, the formerly unsuspected broad distribution of these toxins was revealed. Toxicological studies with these compounds shows repeatedly low LD50 values in different mammals, revealing an acute toxic effect on several organs, as demonstrated by different routes of exposure. Bioassays tested for some marine invertebrates and evidences from environmental populations exposed to the toxins also give indications of the high impact that these compounds may have on natural food webs. The recognition of its wide distribution coupled with the poisoning effects that these toxins can have on animals and especially on humans have concerned the scientific community. In this paper, we review the current knowledge on the effects of PTX and its analogs on different organisms, exposing the impact that these toxins may have in coastal ecosystems.

  16. 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......, metabolism and inflammation. By means of personal monitoring and biomarkers of internal dose, biologically effective dose and susceptibility, it should be possible to characterize individual exposure and identify air pollution sources with relevant biological effects. In a series of studies, individual...... setting, biological effects of air pollutants appear mainly related to oxidative stress via personal exposure and not to urban background levels. Future developments include personal time-resolved monitors for exposure to ultrafine PM and PM(2.5,) use of GPS, as well as genomics and proteomics based...

  17. 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, antioxidants......-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...

  18. 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

  19. 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.

  20. Effects of saltcedar invasion and biological control on small mammals

    Science.gov (United States)

    Effects of invasive saltcedars (Tamarix spp.) on bird populations and communities have received considerable interest, but impacts on other vertebrate taxa have received less attention. Moreover, only one published study examined effects on vertebrates of biological control efforts directed at saltc...

  1. Electromagnetic field induced biological effects in humans.

    Science.gov (United States)

    Kaszuba-Zwolińska, 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. Rifaximin: An Antibiotic with Important Biologic Effects.

    Science.gov (United States)

    DuPont, H L

    2015-01-01

    Rifaximin is a poorly absorbed rifamycin drug with unique pharmacokinetic properties: bile solubility making it highly active against pathogenic and non-pathogenic bacterial flora in the bile-rich small bowel and low water solubility making it active only against highly susceptible bacteria, primarily anaerobes, in the aqueous colon. The drug has anti-inflammatory gut mucosal stabilization properties that are important to its sustained effects in non-infectious diseases. Rifaximin is used chronically or recurrently for hepatic encephalopathy and diarrhea-predominant irritable bowel syndrome. Monitoring of long-term use of rifaximin for development of resistance and then determining whether developed resistance is associated with reduced efficacy are needed. Studies of changes of intestinal flora during therapy and the health implications of these changes are also needed. PMID:26202192

  3. Biological effect of radiation on human

    International Nuclear Information System (INIS)

    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. 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.

  5. 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.)

  6. 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)

  7. Biologic

    CERN Document Server

    Kauffman, L H

    2002-01-01

    In this paper we explore the boundary between biology and the study of formal systems (logic). In the end, we arrive at a summary formalism, a chapter in "boundary mathematics" where there are not only containers but also extainers ><, entities open to interaction and distinguishing the space that they are not. The boundary algebra of containers and extainers is to biologic what boolean algebra is to classical logic. We show how this formalism encompasses significant parts of the logic of DNA replication, the Dirac formalism for quantum mechanics, formalisms for protein folding and the basic structure of the Temperley Lieb algebra at the foundations of topological invariants of knots and links.

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

    International Nuclear Information System (INIS)

    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.)

  9. Physical and biological factors determining the effective proton range

    Energy Technology Data Exchange (ETDEWEB)

    Grün, Rebecca [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291 (Germany); Institute of Medical Physics and Radiation Protection, University of Applied Sciences Gießen, Gießen 35390 (Germany); Medical Faculty of Philipps-University Marburg, Marburg 35032 (Germany); Friedrich, Thomas; Krämer, Michael; Scholz, Michael [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291 (Germany); Zink, Klemens [Institute of Medical Physics and Radiation Protection, University of Applied Sciences Gießen, Gießen 35390, Germany and Department of Radiotherapy and Radiation Oncology, University Medical Center Giessen and Marburg, Marburg 35043 (Germany); Durante, Marco [Department of Biophysics, GSI Helmholtzzentrum für Schwerionenforschung, Darmstadt 64291, Germany and Department of Condensed Matter Physics, Darmstadt University of Technology, Darmstadt 64289 (Germany); Engenhart-Cabillic, Rita [Medical Faculty of Philipps-University Marburg, Marburg 35032, Germany and Department of Radiotherapy and Radiation Oncology, University Medical Center Giessen and Marburg, Marburg 35043 (Germany)

    2013-11-15

    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.

  10. Biological effects in intramuscular 239Pu administration during chelatotherapy

    International Nuclear Information System (INIS)

    Durable (up to 64 days) application of complexones (Ca and Zn DTPA) in the case of intramuscular administration of 239Pu large amounts in rats is studied. The results of studying the biological effect proving considerable decrease of the average lifespan of rats are given

  11. Biological Effects and Chemical Measurements in Irish Marine Waters

    OpenAIRE

    Giltrap, Michelle, (Thesis); McHugh, Brendan; Ronan, Jenny; Wilson, James; MCGOVERN Evin

    2014-01-01

    The overall aim of this project was to increase Ireland’s capacity for the generation of integrated monitoring of biological effects and chemical measurement data and for the completion of a pilot scale assessment of the quality of the Irish marine environment at a number of selected locations.

  12. Thermal effects of laser radiation in biological tissue.

    OpenAIRE

    Cummins, L; Nauenberg, M.

    1983-01-01

    A theoretical model is presented that simulates the thermal effects of laser radiation incident on biological tissue. The multiple scattering and absorption of the laser beam and the thermal diffusion process in the tissue are evaluated by a numerical technique that is well suited for microcomputers. Results are compared with recent empirical observations.

  13. Biological potential of extraterrestrial materials - 1. Nutrients in carbonaceous meteorites, and effects on biological growth

    Science.gov (United States)

    Mautner, Michael N.

    1997-06-01

    Soil nutrient analysis of the Murchison C2 carbonaceous chondrite shows biologically available S, P, Ca, Mg, Na, K and Fe and cation exchange capacity (CEC) at levels comparable with terrestrial agricultural soils. Weathering, and aqueous, hydrothermal (121°C, 15 min) and high-temperature (550°C, 3 h) processing increase the extractable nutrients. Extractable phosphorus (by 0.3 M NH 4F + 0.1 M HCl) content, which may be growth-limiting, is 6.3 μg g -1 in the unprocessed meteorite, but increases to 81 μg g -1 by hydrothermal processing and weathering, and to 130 μg g -1 by high temperature processing. The cation exchange capacity (CEC), attributed mainly to the organic fraction, corresponds responds to 345 meq per 100 g of the polymer, suggesting one ionizable COOH or OH group per 3-4 aromatic rings. The Allende C3(V) meteorite has low extractable Ca, Mg and K, in parallel to its low organic content and CEC, but high extractable P levels (160 μg g -1). Biological effects are observed on growth of the soil microorganisms Flavobacterium oryzihabitans and Nocardia asteroides in meteorite extracts, and the population levels suggest that P is the limiting nutrient. Effects on plant growth are examined on Solanum tuberosum (potato), where extracts of the Murchison meteorite lead to enhanced growth and pigmentation. The biologically available organic and inorganic nutrients in carbonaceous chondrites can provide concentrated solutions for prebiotic and early life processes, and serve as soils and fertilizers for future space-based biological expansion.

  14. Effects of weak magnetic fields on biological systems: physical aspects

    International Nuclear Information System (INIS)

    The effect of weak magnetic fields on biosystems is the subject matter of the science of magnetobiology. There are objective factors, due to theory lagging far behind experiment, that are hindering the development of this science. Academic interest in the subject is restrained by the fact that experimental data lack a clear physical explanation. Besides, there is a strong imbalance in how physics and biology are involved in magnetobiology, the former being still in infancy in this respect. It is this imbalance which is currently the driving force for the development of the theory of magnetobiology. This brief analytical review focuses on the physical aspects of magnetobiological research. The task of magnetobiology is to explore the biological effects of weak magnetic fields and to understand mechanisms behind these effects. Magnetobiology is part of a more general issue of the biological impact of weak and hyperweak physico-chemical factors. It is believed that such factors operate even below the trigger threshold for protective biological mechanisms and are therefore capable of accumulating at the subcellular level. The so-called 'kT-problem' is discussed in detail, and the interference mechanisms of the molecular gyroscope and of molecular states in an idealized protein cavity are suggested as candidate solutions. (reviews of topical problems)

  15. Effect of biologic agents on radiographic progression of rheumatoid arthritis

    Directory of Open Access Journals (Sweden)

    Gabriel J Tobón

    2010-08-01

    Full Text Available Gabriel J Tobón1, Alain Saraux1,2, Valérie Devauchelle-Pensec1,21Immunology Laboratory, Morvan Hospital, Université de Bretagne Occidentale, Brest, France; 2Rheumatology Unit, Hôpital de la Cavale Blanche, CHU Brest, FranceAbstract: The treatment of rheumatoid arthritis (RA has benefited over the last few years from the introduction of biologic agents whose development was based on new insights into the immunological factors involved in the pathogenesis of RA and the development of joint damage. These biological agents have been proven effective in RA patients with inadequate responses to synthetic disease-modifying antirheumatic drugs (DMARDs. Preventing joint damage is now the primary goal of RA treatment, and guidelines exist for the follow-up of joint abnormalities. Most biologic agents produced high clinical and radiological response rates in patients with established or recent-onset RA. Thus, for the first time, obtaining a remission is a reasonable treatment goal in RA patients. Factors that are crucial to joint damage control are: early initiation of DMARDs, use of intensive treatments including biological agents, and close monitoring of clinical disease activity and radiographic progression. However, some patients remain unresponsive to all available treatments and continue to experience joint damage progression. A major objective now is to identify patients at high risk for severe joint damage, in order to tailor the treatment regimen to their specific needs.Keywords: rheumatoid arthritis, radiographic progression, biologics

  16. Predictive modeling of nanomaterial exposure effects in biological systems

    Directory of Open Access Journals (Sweden)

    Liu X

    2013-09-01

    Full Text Available Xiong Liu,1 Kaizhi Tang,1 Stacey Harper,2 Bryan Harper,2 Jeffery A Steevens,3 Roger Xu1 1Intelligent Automation, Inc., Rockville, MD, USA; 2Department of Environmental and Molecular Toxicology, School of Chemical, Biological, and Environmental Engineering, Oregon State University, Corvallis, OR, USA; 3ERDC Environmental Laboratory, Vicksburg, MS, USA Background: Predictive modeling of the biological effects of nanomaterials is critical for industry and policymakers to assess the potential hazards resulting from the application of engineered nanomaterials. Methods: We generated an experimental dataset on the toxic effects experienced by embryonic zebrafish due to exposure to nanomaterials. Several nanomaterials were studied, such as metal nanoparticles, dendrimer, metal oxide, and polymeric materials. The embryonic zebrafish metric (EZ Metric was used as a screening-level measurement representative of adverse effects. Using the dataset, we developed a data mining approach to model the toxic endpoints and the overall biological impact of nanomaterials. Data mining techniques, such as numerical prediction, can assist analysts in developing risk assessment models for nanomaterials. Results: We found several important attributes that contribute to the 24 hours post-fertilization (hpf mortality, such as dosage concentration, shell composition, and surface charge. These findings concur with previous studies on nanomaterial toxicity using embryonic zebrafish. We conducted case studies on modeling the overall effect/impact of nanomaterials and the specific toxic endpoints such as mortality, delayed development, and morphological malformations. The results show that we can achieve high prediction accuracy for certain biological effects, such as 24 hpf mortality, 120 hpf mortality, and 120 hpf heart malformation. The results also show that the weighting scheme for individual biological effects has a significant influence on modeling the overall impact of

  17. Evaluation of radiobiological effects in 3 distinct biological models

    International Nuclear Information System (INIS)

    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

  18. Radiolabelled substrates for studying biological effects of trace contaminants

    International Nuclear Information System (INIS)

    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; 14C-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

  19. Biological effects of exposure to magnetic resonance imaging: an overview

    Directory of Open Access Journals (Sweden)

    Formica Domenico

    2004-04-01

    Full Text Available Abstract The literature on biological effects of magnetic and electromagnetic fields commonly utilized in magnetic resonance imaging systems is surveyed here. After an introduction on the basic principles of magnetic resonance imaging and the electric and magnetic properties of biological tissues, the basic phenomena to understand the bio-effects are described in classical terms. Values of field strengths and frequencies commonly utilized in these diagnostic systems are reported in order to allow the integration of the specific literature on the bio-effects produced by magnetic resonance systems with the vast literature concerning the bio-effects produced by electromagnetic fields. This work gives an overview of the findings about the safety concerns of exposure to static magnetic fields, radio-frequency fields, and time varying magnetic field gradients, focusing primarily on the physics of the interactions between these electromagnetic fields and biological matter. The scientific literature is summarized, integrated, and critically analyzed with the help of authoritative reviews by recognized experts, international safety guidelines are also cited.

  20. Biological effects of low doses of ionizing radiation

    International Nuclear Information System (INIS)

    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)

  1. 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. PMID:25722878

  2. Advances in the biological effects of terahertz wave radiation

    Institute of Scientific and Technical Information of China (English)

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

    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.

  3. Oxygen effect in radiation biology: caffeine and serendipity

    International Nuclear Information System (INIS)

    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)

  4. Biological effect of nitrogen ion implantation on stevia

    International Nuclear Information System (INIS)

    Dry seed of stevia were implanted by 35∼150 keV nitrogen ions with various doses. The biological effect in M1 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 M1 stevia was lower than that of γ-rays. (6 refs., 1 fig., 4 tabs.)

  5. Biological effects of space loading on salvia miltiorrhiza

    International Nuclear Information System (INIS)

    To study the SP1 biological effects of space loading on Salvia miltiorrhiza seeds. Dry seeds were carried by breeding satellite-Shijian 8, and seeds were sowed in the field after returning the ground. Some parameters were measured, such as growth stage, seed vigor, plant traits above ground, root feature and seeding characteristics. Variation of DNA was tested by SRAP. The results showed that DNA variation happened, the rate of germination and emergence in SP1 generation increased significantly, the blooming date was advanced, rachis length and flower number of SP1 generation also increased compared with CK. At the same time, the root features and seeding characteristics were improved, the CV was increased in the relative traits, but leaf growth was inhibited significantly. The biological effects of space loading on dry seed of Salvia miltiorrhiza might be an important index for germplasm improvement and breeding. (authors)

  6. Effects of UV and microwave radiation on biological material

    International Nuclear Information System (INIS)

    For the present study, ten publications on the effect of UV radiation were analyzed. In vitro tests were carried out with one biological substance and seven different human or animal organs and biocytocultures. In vivo, three bacterial strains were irradiated and four irradiation experiments were carried out on mice. As to the effect of microwave radiation, eleven publications were analyzed. In vitro tests were carried out with one biological substance and three animal organs. In vivo, one bacterial strain was irradiated and eight irradiation experiments were carried out on different types of animals. The study's aim was to obtain a survey on biochemical changes of the organisms. Phenomenological changes were given only when the corresponding articles contained further investigation results. Behavioral changes were not taken into account. The results published by the authors of the original papers were compiled in a kind of dictionary. All relevant data are listed in a defined order. (orig.)

  7. Biological effects of low-intensity millimetric radiation

    Energy Technology Data Exchange (ETDEWEB)

    Betskiy, O.V.; Putvinskiy, A.V.

    1986-10-01

    The authors discuss a possible role of strong absorption of millimetric (MM) waves by water molecules in the primary mechanism of the reaction of biological systems to MM irradiation. Data are given on the interaction of MM radiation with simple aqueous systems. Primary attention is given to the phenomenon of convective mixing of aqueous solutions under the effect of low-intensity MM waves (1 ... 10 mW/cm/sup 2/). 12 references, 6 figures.

  8. On Quantum Effects in a Theory of Biological Evolution

    OpenAIRE

    Martin-Delgado M.A.

    2012-01-01

    We construct a descriptive toy model that considers quantum effects on biological evolution starting from Chaitin's classical framework. There are smart evolution scenarios in which a quantum world is as favorable as classical worlds for evolution to take place. However, in more natural scenarios, the rate of evolution depends on the degree of entanglement present in quantum organisms with respect to classical organisms. If the entanglement is maximal, classical evolution turns out to be more...

  9. BIOLOGICAL EFFECTS OF PULSED SHORT WAVE TREATMENT. AN EXPERIMENTAL STUDY

    OpenAIRE

    Dogaru Gabriela; Crăciun Constantin

    2015-01-01

    Pulsed short waves are short electromagnetic waves emitted as intermittent trains with a fixed duration, separated by free intervals of variable duration. The biological effects of pulsed short waves could be explained according to most of the authors by an activation of cellular enzymatic reactions, a stimulation of energy metabolism, a stimulation of liver function, of adrenal gland function and of the reticulocyte system, changes in cell permeability, by an increase of peripheral blood flo...

  10. Metabolism and biological effects of alpha-emitting radionuclides

    International Nuclear Information System (INIS)

    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. Biological effects of the ionizing radiation. Press breakfast

    International Nuclear Information System (INIS)

    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.)

  12. Biological Effects of Phosphate on Fibroblast-Like Synoviocytes

    OpenAIRE

    Yubo Sun; Mauerhan, David R.; Deepthi Chaturvedi; Hanley, Edward N; Gruber, Helen E.

    2012-01-01

    This study sought to examine the expression of genes implicated in phosphate transport and pathological calcification in osteoarthritis (OA) and rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) and investigate the biological effects of phosphate. Results revealed that several genes, which were implicated in phosphate transport and pathological calcification, were differentially expressed in OA FLS and RA FLS. Phosphate stimulated the expression of matrix metalloproteinse-1, matrix...

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

    OpenAIRE

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

    2014-01-01

    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 th...

  14. 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.

  15. Evolutionary tradeoffs between economy and effectiveness in biological homeostasis systems.

    Directory of Open Access Journals (Sweden)

    Pablo Szekely

    Full Text Available Biological regulatory systems face a fundamental tradeoff: they must be effective but at the same time also economical. For example, regulatory systems that are designed to repair damage must be effective in reducing damage, but economical in not making too many repair proteins because making excessive proteins carries a fitness cost to the cell, called protein burden. In order to see how biological systems compromise between the two tasks of effectiveness and economy, we applied an approach from economics and engineering called Pareto optimality. This approach allows calculating the best-compromise systems that optimally combine the two tasks. We used a simple and general model for regulation, known as integral feedback, and showed that best-compromise systems have particular combinations of biochemical parameters that control the response rate and basal level. We find that the optimal systems fall on a curve in parameter space. Due to this feature, even if one is able to measure only a small fraction of the system's parameters, one can infer the rest. We applied this approach to estimate parameters in three biological systems: response to heat shock and response to DNA damage in bacteria, and calcium homeostasis in mammals.

  16. Lung function, biological monitoring, and biological effect monitoring of gemstone cutters exposed to beryls

    Science.gov (United States)

    Wegner, R.; Heinrich-Ramm, R.; Nowak, D.; Olma, K.; Poschadel, B.; Szadkowski, D.

    2000-01-01

    OBJECTIVES—Gemstone cutters are potentially exposed to various carcinogenic and fibrogenic metals such as chromium, nickel, aluminium, and beryllium, as well as to lead. Increased beryllium concentrations had been reported in the air of workplaces of beryl cutters in Idar-Oberstein, Germany. The aim of the survey was to study the excretion of beryllium in cutters and grinders with occupational exposure to beryls—for example, aquamarines and emeralds—to examine the prevalence of beryllium sensitisation with the beryllium lymphocyte transformation test (BeLT), to examine the prevalence of lung disease induced by beryllium, to describe the internal load of the respective metals relative to work process, and to screen for genotoxic effects in this particular profession.
METHODS—In a cross sectional investigation, 57 out of 100 gemstone cutters working in 12 factories in Idar-Oberstein with occupational exposure to beryls underwent medical examinations, a chest radiograph, lung function testing (spirometry, airway resistance with the interrupter technique), and biological monitoring, including measurements of aluminium, chromium, and nickel in urine as well as lead in blood. Beryllium in urine was measured with a newly developed direct electrothermal atomic absorption spectroscopy technique with a measurement limit of 0.06 µg/l. Also, cytogenetic tests (rates of micronuclei and sister chromatid exchange), and a BeLT were performed. Airborne concentrations of beryllium were measured in three factories. As no adequate local control group was available, the cutters were categorised into those with an exposure to beryls of >4 hours/week (group A) and ⩽4 hours/week (group B).
RESULTS—Clinical, radiological, or spirometric abnormalities indicating pneumoconiosis were detected in none of the gemstone cutters. Metal concentrations in biological material were far below the respective biological limit values, and beryllium in urine was only measurable in

  17. 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

  18. Cytogenetic measurements of the relative biological effectiveness of tritium

    International Nuclear Information System (INIS)

    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

  19. Biological effects of low level exposures to chemicals and radiation

    International Nuclear Information System (INIS)

    In May 1990 a group of scientists representing several federal agencies, the International Society of Regulatory Toxicology and Pharmacology, the private sector, and academia met to develop a strategy to encourage the study of the biological effects of low level exposures (BELLE) to chemical agents and radioactivity. A workshop was held in 1991 with seven invited speakers focusing on the toxicological implications of biological adaptations. The selection of topics and speakers was designed to consider critically the concept of hormesis, not only in a broad, conceptual manner, but also at the molecular and biochemical levels. These presentations offered a complementary perspective on the diverse range of molecular mechanisms that can become activated at low levels of toxicant exposure. In addition to chemical toxicology research, an overview of current research on 'Effects of low-dose radiation on the immune response' was presented as well as 'Cellular adaptation as an important response during chemical carcinogenesis'. The final presentation was devoted to biostatistical considerations when designing studies that address issues associated with the biological responses to low doses of chemicals and radiation, as well as issues in interpretation of the findings from such studies

  20. Effective biological dose from occupational exposure during nanoparticle synthesis

    International Nuclear Information System (INIS)

    Nanomaterial and nanotechnology safety require the characterization of occupational exposure levels for completing a risk assessment. However, equally important is the estimation of the effective internal dose via lung deposition, transport and clearance mechanisms. An integrated source-to-biological dose assessment study is presented using real monitoring data collected during nanoparticle synthesis. Experimental monitoring data of airborne exposure levels during nanoparticle synthesis of CaSO4 and BiPO4 nanoparticles in a research laboratory is coupled with a human lung transport and deposition model, which solves in an Eulerian framework the general dynamic equation for polydisperse aerosols using particle specific physical-chemical properties. Subsequently, the lung deposition model is coupled with a mathematical particle clearance model providing the effective biological dose as well as the time course of the biological dose build-up after exposure. The results for the example of BiPO4 demonstrate that even short exposures throughout the day can lead to particle doses of 1.10·E+08/(kg-bw·8h-shift), with the majority accumulating in the pulmonary region. Clearance of particles is slow and is not completed within a working shift following a 1 hour exposure. It mostly occurs via macrophage activity in the alveolar region, with small amounts transported to the interstitium and less to the lymph nodes.

  1. Effective biological dose from occupational exposure during nanoparticle synthesis

    Science.gov (United States)

    Demou, Evangelia; Tran, Lang; Housiadas, Christos

    2009-02-01

    Nanomaterial and nanotechnology safety require the characterization of occupational exposure levels for completing a risk assessment. However, equally important is the estimation of the effective internal dose via lung deposition, transport and clearance mechanisms. An integrated source-to-biological dose assessment study is presented using real monitoring data collected during nanoparticle synthesis. Experimental monitoring data of airborne exposure levels during nanoparticle synthesis of CaSO4 and BiPO4 nanoparticles in a research laboratory is coupled with a human lung transport and deposition model, which solves in an Eulerian framework the general dynamic equation for polydisperse aerosols using particle specific physical-chemical properties. Subsequently, the lung deposition model is coupled with a mathematical particle clearance model providing the effective biological dose as well as the time course of the biological dose build-up after exposure. The results for the example of BiPO4 demonstrate that even short exposures throughout the day can lead to particle doses of 1.10·E+08#/(kg-bw·8h-shift), with the majority accumulating in the pulmonary region. Clearance of particles is slow and is not completed within a working shift following a 1 hour exposure. It mostly occurs via macrophage activity in the alveolar region, with small amounts transported to the interstitium and less to the lymph nodes.

  2. Sodium selenite and cancer related lymphedema: Biological and pharmacological effects.

    Science.gov (United States)

    Pfister, Christina; Dawzcynski, Horst; Schingale, Franz-Josef

    2016-09-01

    A significant percentage of cancer patients develop secondary lymphedema after surgery or radiotherapy. The preferred treatment of secondary lymphedema is complex physical therapy. Pharmacotherapy, for example with diuretics, has received little attention, because they were not effective and only offered short-term solutions. Sodium selenite showed promise as a cost-effective, nontoxic anti-inflammatory agent. Treatment with sodium selenite lowers reactive oxygen species (ROS) production, causes a spontaneous reduction in lymphedema volume, increases the efficacy of physical therapy for lymphedema, and reduces the incidence of erysipelas infections in patients with chronic lymphedema. Besides biological effects in reducing excessive production of ROS, sodium selenite also displays various pharmacological effects. So far the exact mechanisms of these pharmacological effects are mostly unknown, but probably include inhibition of adhesion protein expression. PMID:27267968

  3. Biological effects of pulsating magnetic fields: role of solitons

    CERN Document Server

    Brizhik, Larissa

    2014-01-01

    In this paper, we analyze biological effects produced by magnetic fields in order to elucidate the physical mechanisms, which can produce them. We show that there is a chierarchy of such mechanisms and that the mutual interplay between them can result in the synergetic outcome. In particular, we analyze the biological effects of magnetic fields on soliton mediated charge transport in the redox processes in living organisms. Such solitons are described by nonlinear systems of equations and represent electrons that are self-trapped in alpha-helical polypeptides due to the moderately strong electron-lattice interaction. They represent a particular type of disssipativeless large polarons in low-dimensional systems. We show that the effective mass of solitons in the is different from the mass of free electrons, and that there is a resonant effect of the magnetic fields on the dynamics of solitons, and, hence, on charge transport that accompanies photosynthesis and respiration. These effects can result in non-therm...

  4. 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

  5. Ionol [BHT]. Distribution in the organism, metabolism, and biological effect. II. Biological effects of ionol (survey)

    International Nuclear Information System (INIS)

    In these experiments, a 25 mg/kg dose of ionol, administered to mice immediately after transplantation of melanoma B-16 or injection of tumor cells, inhibited the growth of pigmented B-16 cells and somewhat decreased the number of metastases. Ionol inhibited the mutagenic effect of benz(a)pyrene in vitro and in a culture of Salmonella typhimurium. In a mix with butylhydroxyanisole and propyl gallate, it decreased the number of mutations induced by gamma irradiation in the same culture. It protected mice from dominant lethal mutations and hereditary translocations induced by ethyl methanesulfonate (EMS). When ionol was present in the feed in a dose of 0.75% it reduced the lethal effect in mice of dimethylnitrosamine, EMS, ethylene dibromide and cyclophosphamide

  6. Countermeasures for space radiation induced adverse biologic effects

    Science.gov (United States)

    Kennedy, A. R.; Wan, X. S.

    2011-11-01

    Radiation exposure in space is expected to increase the risk of cancer and other adverse biological effects in astronauts. The types of space radiation of particular concern for astronaut health are protons and heavy ions known as high atomic number and high energy (HZE) particles. Recent studies have indicated that carcinogenesis induced by protons and HZE particles may be modifiable. We have been evaluating the effects of proton and HZE particle radiation in cultured human cells and animals for nearly a decade. Our results indicate that exposure to proton and HZE particle radiation increases oxidative stress, cytotoxicity, cataract development and malignant transformation in in vivo and/or in vitro experimental systems. We have also shown that these adverse biological effects can be prevented, at least partially, by treatment with antioxidants and some dietary supplements that are readily available and have favorable safety profiles. Some of the antioxidants and dietary supplements are effective in preventing radiation induced malignant transformation in vitro even when applied several days after the radiation exposure. Our recent progress is reviewed and discussed in the context of the relevant literature.

  7. Health and biological effects of non-ionizing radiations

    International Nuclear Information System (INIS)

    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.)

  8. Biological effects of electromagnetic fields; Biologische Wirkungen elektromagnetischer Felder

    Energy Technology Data Exchange (ETDEWEB)

    David, E. [Inst. fuer Physiologie, Univ. Witten-Herdecke (Germany)

    1993-07-26

    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) [Deutsch] Der Autor beschreibt in seinem allgemeinverstaendlichen Artikel zuerst die physikalischen Grundlagen elektromagnetischer Felder und ihre grundsaetzliche biologische Bedeutung und Auswirkungen fuer Tiere und Menschen, bevor er auf die Diskussion um Grenzwerte und Gefahren eingeht. Ausfuehrlicher behandelt der Artikel moegliche Zusammenhaenge mit Leukaemie sowie mit der Melatoninproduktion. (vhe)

  9. Hydrodynamic collective effects of active proteins in biological membranes

    CERN Document Server

    Koyano, Yuki; Mikhailov, Alexander S

    2016-01-01

    Lipid bilayers forming biological membranes are known to behave as viscous 2D fluids on submicrometer scales; usually they contain a large number of active protein inclusions. Recently, it has been shown [Proc. Nat. Acad. Sci. USA 112, E3639 (2015)] that such active proteins should in- duce non-thermal fluctuating lipid flows leading to diffusion enhancement and chemotaxis-like drift for passive inclusions in biomembranes. Here, a detailed analytical and numerical investigation of such effects is performed. The attention is focused on the situations when proteins are concentrated within lipid rafts. We demonstrate that passive particles tend to become attracted by active rafts and are accumulated inside them.

  10. Inner-shell ionization and biological radiations effects

    International Nuclear Information System (INIS)

    Biological effects of K-ionizations followed by Auger cascades have been much studied to elucidate mechanisms of cell inactivation and DNA repair and to develop therapeutic applications. Experiments performed with incorporated radionuclides (125I) or incorporated elements (Br, I, P) photoionized in the K-shell using synchrotron radiation all displayed a K + Auger enhancement. The interest in K-ionization rose again when recent works suggested that K-ionizations in C, N, 0 atoms of DNA could be the primary physical events responsible for cell death induced by heavy ions. Photoabsorption experiments at the C-K threshold support this hypothesis. (authors)

  11. [Placebo effect: clinical, biological and therapeutical involvements in depression].

    Science.gov (United States)

    Gourion, D; Mouchabac, S

    2016-02-01

    The placebo effect is an excellent model for understanding the mechanisms underlying the interaction between a subjective and complex mental activity (beliefs, expectations, hopes, learning, patient-physician relationship, socio-cultural context .) with different neural and biological systems. Initially, research on the placebo effect has focused on the mechanisms of pain and analgesia. The cognitive processes of conditioning and reward anticipation (hope of a relief) were highlighted. The involvement of different neurobiological pathways has been clearly shown: endogenous opioids, CCK, dopaminergic pathways, endocannabinoids, immunological factors… More recently, the field has open towards new perspectives: depression and anxiety, motor disorders, immune system, endocrine system. Intensive research in the field emerges because of its fundamental implications in neuroscience research but also because of the ethical, clinical and therapeutical issues. Moreover, the placebo effect is considered as a main methodological mean issue in clinical trials that allows the demonstration of the efficacy and tolerance of new drugs. In the field of psychiatry, depression is a placebo highly-sensitive disorder: placebo response rates in clinical trials are of the order of 30 % to 40 %. The identification of biological markers of placebo response, such as neuroimaging and quantitative electroencephalography may lead to develop more efficient models in clinical research. PMID:26879253

  12. Spatial interpolation of biologically effective UV radiation over Poland

    Science.gov (United States)

    Walawender, J.; Ustrnul, Z.

    2010-09-01

    The ultraviolet(UV) radiation plays an important role in the Earth-Atmosphere System. It has a positive influence on both human health and natural environment but it may also be very harmful if UV exposure exceeds "safe" limits. For that reason knowledge about spatial distribution of biologically effective UV doses seems to be crucial in minimization or complete elimination of the negative UV effects. The main purpose of this study is to find the most appropriate interpolation method in order to create reliable maps of the biologically effective UV radiation over Poland. As the broadband UV measurement network in Poland is very sparse, erythemaly weighted UV radiation data reconstructed from homogeneous global solar radiation records were used. UV reconstruction model was developed in Centre of Aerology (Institute of Meteorology and Water Management) within COST Action 726 - ‘Long term changes and climatology of UV radiation over Europe'. The model made it possible to reconstruct daily erythemal UV doses for 21 solar radiation measurement stations in the period 1985 - 2008. Mapping methodology included the following processing steps: exploratory spatial data analysis, verification of additional variables, selection and parameterization of interpolation model, accuracy assessment and cartographic visualization. Several different stochastic and deterministic interpolation methods along with various empirical semivariogram models were tested. Multiple regression analysis was performed in order to examine statistical relationship between UV radiation and additional environmental variables such as: elevation, latitude, stratospheric ozone content and cloud cover. The data were integrated, processed and visualized within GIS environment.

  13. Effects of industrial chemicals and radioactive materials in biological systems

    International Nuclear Information System (INIS)

    Much has been written on the effects of radiation and toxic chemicals on biological systems. In this communication general considerations regarding these topics will be discussed very briefly; the major emphasis will be focused on the effects of chemicals, namely ethyl methane sulfonate (EMS) on Amoeba, Advantages to the use of amoeba for studying the effects of radiation and chemicals include the following: large mononucleate unicellular organisms having a long generation time; opportunity to study cellular organelles and biochemical and genetic alterations in a single cell system; and a long cell cycle, the stages of which can be synchronized without resorting to chemical treatment or temperature shock and thereby readily permitting study at defined stages of the cell's life cycle. This, in turn, is discussed in light of current disposal methods for this type of waste and how it might be safely disposed of

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

    International Nuclear Information System (INIS)

    A life-span study was conducted in 128 beagle dogs to determine the biological effects of intravenously injected 224Ra chloride. The 224Ra 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 224Ra resulting in initial body burdens of approximately 13, 40, 120 or 350 kBq of 224Ra 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 224Ra (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 224Ra 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 224Ra 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

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

    International Nuclear Information System (INIS)

    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

  16. Biological effect of carbon beams on cultured human cells

    International Nuclear Information System (INIS)

    This study was performed to determine the biological effect of carbon beams on 13 human tumor cells, in comparison with 200 KVp X-rays. Carbon beams were generated by the Riken Ring Cyclotron. The RBE (relative biological effectiveness) values were distributed from 1.46 to 2.20 for LET of 20 keV/μm, and 2.29-3.54 for 80 keV/μm. The RBEs were increased in all cell lines as the LET of carbon beams was increased from 20 to 80 keV/μm. There was no significant difference in radiosensitivity between cells from adenocarcinoma and those from squamous cell carcinoma. The relationship between the radiosensitivity of cells to X-rays and RBE was analyzed, but no significant correlation was suggested. Several survival curves of 20-40 keV/μm carbon beam irradiation showed the initial shoulders and the recovery ratios between two split doses were determined. Recovery was observed for LET of 2O keV/μm but not for that of 40 keV/μm. Furthermore, recovery ratios were 1.0-1.8, smaller than those for X-rays (1.5-2.4). (author)

  17. 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)

  18. Modeling of biological doses and mechanical effects on bone transduction

    CERN Document Server

    Rieger, Romain; Jennane, Rachid; 10.1016/j.jtbi.2011.01.003

    2012-01-01

    Shear stress, hormones like parathyroid and mineral elements like calcium mediate the amplitude of stimulus signal which affects the rate of bone remodeling. The current study investigates the theoretical effects of different metabolic doses in stimulus signal level on bone. The model was built considering the osteocyte as the sensing center mediated by coupled mechanical shear stress and some biological factors. The proposed enhanced model was developed based on previously published works dealing with different aspects of bone transduction. It describes the effects of physiological doses variations of Calcium, Parathyroid Hormone, Nitric Oxide and Prostaglandin E2 on the stimulus level sensed by osteocytes in response to applied shear stress generated by interstitial fluid flow. We retained the metabolic factors (Parathyroid Hormone, Nitric Oxide, and Prostaglandin E2) as parameters of bone cell mechanosensitivity because stimulation/inhibition of induced pathways stimulates osteogenic response in vivo. We t...

  19. Microwave Hall effect measurements on biological and organic semiconductors

    International Nuclear Information System (INIS)

    Microwave Hall effect measurements have been performed by improved 10 GHz bimodal cavity resonators with hybrid end walls used to avoid the background signal that obscures the measurements on low mobility materials. Hall mobility results on copper phthalocyanines CuPc and other organic semiconductors, in the range of 8 cm2/V s to 60 cm2/V s, provide evidence of acoustic phonon scattering as the dominant conduction mechanism. Presently, the microwave Hall effect seems to represent the only means available for quantitative measurements on biological substances like DNA and proteins, which yield mobility values lower than 10 cm2/V s, and are therefore consistent with conduction mechanism involving hopping of charge carriers between localized energy sites

  20. Late biological effects from internal and external exposure

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Late biological effects from internal and external exposure

    International Nuclear Information System (INIS)

    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

  2. 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

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

    Science.gov (United States)

    Braeckman, Ulrike; Provoost, Pieter; Moens, Tom; Soetaert, Karline; Middelburg, Jack J; Vincx, Magda; Vanaverbeke, Jan

    2011-01-01

    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 (13)C 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(13)C) of the added diatoms was highest in the physical mixing treatment, where macrobenthos was absent and the diatom (13)C 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(13)C 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 source

  4. Biological dosimetry by the radiation effects on the skin

    International Nuclear Information System (INIS)

    In cases of partial body over-exposure, the dose estimation with personal monitors or with reconstruction of exposed conditions is often impossible without considerable error. Clinical signs of irradiated skin, such as epilation or moist desquamation have been used as the indicators of doses in the radiological accidents, because each sign has the threshold dose. As hair growth is known to be sensitive to radiation, the dose-effect relationship of the delay of hair regrowth and the reduction in hair length of mice after irradiation were examined to investigate if they can be used as biological dosimeters. Hairs on the dorsal skin of 290 ICR mice (8 weeks old) were shaved and irradiated with a Sr-90/Y-90 β-ray source in the early anagen and the midanagen stages of the hair cycle. Skin doses were from 0.5 to 10 Gy. The time of hair regrowth and the hair length were examined with the scaling loupe. Dose-effect relationship of the delay of hair regrowth and reduction in hair length were both clearly dose dependent, fitting the L-Q or L function depending on the stage. Dose estimation functions were derived from the dose-effect relationship curves. The histological observations suggested that hair growth retardation caused by irradiation in midanagen might be due to the cell death and the depression of mitosis in the hair matrix cells. This dose estimation method was applied to the case who was over-exposed to X-ray on his hand and fingers. The findings showed that hair regrowth delay was a sensitive biological dosimeter in the case of partial body over-exposure, which could be applied as early as a few days after over-exposure. The method was simple and non-invasive to the exposed patient. (author)

  5. The non-haematopoietic biological effects of erythropoietin.

    Science.gov (United States)

    Arcasoy, Murat O

    2008-04-01

    In the haematopoietic system, the principal function of erythropoietin (Epo) is the regulation of red blood cell production, mediated by its specific cell surface receptor (EpoR). Following the cloning of the Epo gene (EPO) and characterization of the selective haematopoietic action of Epo in erythroid lineage cells, recombinant Epo forms (epoetin-alfa, epoetin-beta and the long-acting analogue darbepoetin-alfa) have been widely used for treatment of anaemia in chronic kidney disease and chemotherapy-induced anaemia in cancer patients. Ubiquitous EpoR expression in non-erythroid cells has been associated with the discovery of diverse biological functions for Epo in non-haematopoietic tissues. During development, Epo-EpoR signalling is required not only for fetal liver erythropoiesis, but also for embryonic angiogenesis and brain development. A series of recent studies suggest that endogenous Epo-EpoR signalling contributes to wound healing responses, physiological and pathological angiogenesis, and the body's innate response to injury in the brain and heart. Epo and its novel derivatives have emerged as major tissue-protective cytokines that are being investigated in the first human studies involving neurological and cardiovascular diseases. This review focuses on the scientific evidence documenting the biological effects of Epo in non-haematopoietic tissues and discusses potential future applications of Epo and its derivatives in the clinic. PMID:18324962

  6. Research on biological effects of radioactive ion beam

    International Nuclear Information System (INIS)

    The purpose of this study was to evaluate the potential importance of radioactive ion beams such as 9C, 8B and 8Li, representing double radiation sources coming from the external beams themselves and the delayed particles emitted internally, in medical use, cell radiobiological experiments using radioactive 8B beam and corresponding comparable 10B-ion beam were carried out in the secondary beam line (SBL) at Heavy Ion Medical Accelerator in Chiba (HIMAC). In these radiobiological experiments, biological endpoints such as survival fraction, micronucleus frequency and γ-H2AX focus induction at different penetration depths around the Bragg peaks along these beams were measured. Because human salivary gland (HSG) cancer cells were used in the experiments, it is hard to evaluate the biological effectiveness of the radioactive 8B beam exactly based on the results obtained in the radiobiological experiments. Therefore, normal cell line is expected to be employed in future experiments. In addition, a primary 10B beam of 100 MeV/u was used to produce radioactive 8Li beam under the conditions of 6 mm thick Beryllium target and 3.5 mm thick Aluminum degrader in the SBL at HIMAC. The lateral fluence distributions of the produced beam were measured at different penetration depths along the beam direction. To keep the uniformity of the irradiation field suitable for radiobiological experiments using the produced 8Li beam, a narrow momentum width has to be applied so that the beam intensity decreases. (author)

  7. Effect of column ozone on the variability of biologically effective UV radiation at high southern latitudes.

    Science.gov (United States)

    Sobolev, I

    2000-12-01

    Solar irradiance measurements from Ushuaia (Argentina) and Palmer and McMurdo Stations in Antarctica covering four seasons from mid-1993 through early 1997 have been analyzed and their variations compared with column ozone changes. UV irradiances were weighted for biological effectiveness using a published biological weighting function for dose-dependent inhibition of photosynthesis by phytoplankton from the Weddell Sea. All calculations involved integrated daily UV doses and visible exposures (weighted UV and unweighted visible irradiances, respectively). The results show that daily biologically effective total UV doses underwent large short-term variations at all three sites, with day-to-day increases up to 236% at Ushuaia, 285% at Palmer and 99% at McMurdo. Parallel changes in visible exposure indicated that the total UV changes were preponderantly due to variations in cloudiness. On a 12-month basis, daily biologically effective UV doses correlated strongly with visible exposures (R > or = 0.99). Anticorrelations of total UV with ozone, on the other hand, were poor (R > -0.11). The largest daily biologically effective UV doses, and their day-to-day increases, occurred as part of the normal variability related to cloud cover and were seldom associated with significant ozone depletion. UV dose/visible exposure ratios tended to reflect ozone depletion events somewhat more consistently than UV doses alone. With the Weddell Sea phytoplankton weighting function used in this study, antarctic ozone hole events were seldom readily discernible in the biologically effective UV record. The results suggest that, where the UV sensitivity of organisms was similar to that of the Weddell Sea phytoplankton, seasonal ozone depletion had no appreciable effect on annual primary productivity during the 1993-1997 period. Additional data on the geographical and seasonal variation of biological weighting functions are desirable for more comprehensive assessments of ozone depletion

  8. Biological Effects on Fruit Fly by N+ ion Beam Implantation

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Mutation induced by low energy ion beam implantation has beenapplied widely both in plants and microbes. However, due to the vacuum limitation, such ion implantation into animals was never studied except for silkworm. In this study, Pupae of fruit fly were irradiated with different dosage N+ ions at energy 20 KeV to study the biological effect of ion beam on animal. The results showed a saddle-like curve exists between incubate rate and dosage. Damage of pupae by ion beam implantation was observed using scanning electron microscope. Some individuals with incomplete wing were obtained after implantation but no similar character was observed in their offspring. Furthermore, about 5.47% mutants with wide variation appeared in M1 generation. Therefore, ion beam implantation could be widely used for mutation breeding.

  9. 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.

  10. Radiation effects on biological molecules: Influence of the local environment

    International Nuclear Information System (INIS)

    Because it crystallizes with several different molecular environments (e.g. hydrated, anhydrous, and HCl), and in several slightly modified molecular forms, the amino acid proline has been chosen as a probe of possible local effects on the radiation chemistry of biological molecules. In all systems studied so far (proline, proline/sup ./H/sub 2/O, proline /sup ./HCl, hydroxyl-proline, thioproline, and oxoproline), evidence for the ''deamination'' radical has been detected. This product, shown to arise from the primary carboxyl anion in hydroxyproline, is probably the result of electron attack in the other cases, also from the α-carbon. Evidence for the other products is currently under analysis and is discussed along with a summary of the results

  11. Research program on the biological effects of oil pollution

    International Nuclear Information System (INIS)

    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

  12. Biological effects and equivalent doses in radiotherapy: a software solution

    CERN Document Server

    Voyant, Cyril; Roustit, Rudy; Biffi, Katia; Marcovici, Celine Lantieri

    2013-01-01

    The limits of TDF (time, dose, and fractionation) and linear quadratic models have been known for a long time. Medical physicists and physicians are required to provide fast and reliable interpretations regarding the delivered doses or any future prescriptions relating to treatment changes. We therefore propose a calculation interface under the GNU license to be used for equivalent doses, biological doses, and normal tumor complication probability (Lyman model). The methodology used draws from several sources: the linear-quadratic-linear model of Astrahan, the repopulation effects of Dale, and the prediction of multi-fractionated treatments of Thames. The results are obtained from an algorithm that minimizes an ad-hoc cost function, and then compared to the equivalent dose computed using standard calculators in seven French radiotherapy centers.

  13. Behavioural biology: an effective and relevant conservation tool.

    Science.gov (United States)

    Buchholz, Richard

    2007-08-01

    'Conservation behaviour' is a young discipline that investigates how proximate and ultimate aspects of the behaviour of an animal can be of value in preventing the loss of biodiversity. Rumours of its demise are unfounded. Conservation behaviour is quickly building a capacity to positively influence environmental decision making. The theoretical framework used by animal behaviourists is uniquely valuable to elucidating integrative solutions to human-wildlife conflicts, efforts to reintroduce endangered species and reducing the deleterious effects of ecotourism. Conservation behaviourists must join with other scientists under the multidisciplinary umbrella of conservation biology without giving up on their focus: the mechanisms, development, function and evolutionary history of individual differences in behaviour. Conservation behaviour is an increasingly relevant tool in the preservation of nature. PMID:17590477

  14. 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

  15. Effect of a biological activated carbon filter on particle counts

    Institute of Scientific and Technical Information of China (English)

    Su-hua WU; Bing-zhi DONG; Tie-jun QIAO; Jin-song ZHANG

    2008-01-01

    Due to the importance of biological safety in drinking water quality and the disadvantages which exist in traditional methods of detecting typical microorganisms such as Cryptosporidium and Giardia,it is necessary to develop an alternative.Particle counts is a qualitative measurement of the amount of dissolved solids in water.The removal rate of particle counts was previously used as an indicator of the effectiveness of a biological activated carbon(BAC)filter in removing Cryptosporidium and Giardia.The particle counts in a BAC filter effluent over one operational period and the effects of BAC filter construction and operational parameters were investigated with a 10 m3/h pilot plant.The results indicated that the maximum particle count in backwash remnant water was as high as 1296 count/ml and it needed about 1.5 h to reduce from the maximum to less than 50 count/ml.During the standard filtration period,particle counts stay constant at less than 50 count/ml for 5 d except when influ-enced by sand filter backwash remnant water.The removal rates of particle counts in the BAC filter are related to characteristics of the carbon.For example,a columned carbon and a sand bed removed 33.3% and 8.5% of particles,respectively,while the particle counts in effluent from a cracked BAC filter was higher than that of the influent.There is no significant difference among particle removal rates with different filtration rates.High post-ozone dosage(>2 mg/L)plays an important role in particle count removal;when the dosage was 3 mg/L,the removal rates by carbon layers and sand beds decreased by 17.5% and increased by 9.5%,respectively,compared with a 2 mg/L dosage.

  16. Biological Effectiveness and Application of Heavy Ions in Radiation Therapy Described by a Physical and Biological Model

    DEFF Research Database (Denmark)

    Olsen, Kjeld J.; Hansen, Johnny W.

    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......-LET radiation applied simultaneously in therapy....

  17. The effect of green tea on radiation-induced late biological effect in mice

    International Nuclear Information System (INIS)

    This study was performed to determine the effect of Green tea on the late biological effect of mice irradiated with 3 Gy of gamma-radiation. There were various findings including hematopoietic and lymphoid tumor, lung cancer, ovarian cancer and cancer of other lesions. Further studies are needed to characterize better the protective nature of active compounds

  18. 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...

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

    International Nuclear Information System (INIS)

    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)

  20. Biological effects of positron emitters in thyroid cell cultures

    International Nuclear Information System (INIS)

    Full text of publication follows. Aim: Today, the use of 124I- (β+, half-life 4.2 d) is an increasing field in positron emission tomography (PET). In principle, positrons deposit their energy in the surrounding material like electrons. Therefore, we investigated the biological effects of positron emitters in comparison to electrons in vitro. Materials and Methods: two different thyroid cell lines (Fischer Rat Thyroid Cell Line No. 5 (FRTL5) and human papillary thyroid cancer cell line BCPAP) were investigated in vitro. While FRTL5 has been described to express a high level of sodium iodine transporter (NIS), the NIS expression of BCPAP is known to be low. Parallel cultures were incubated with either 50 -400 kBq/ml 124I- (IBA) or 50-400 kBq/ml 131I- (GE Health care). Cell count and radioiodine uptake were determined 24 h to 144 h after isotope application. Additionally, 4',6-diamidino-2-phenylindole (DAPI) staining of ethanol fixed cells was performed and induced apoptosis was determined by morphological analysis of the cell nucleus (condensation, fragmentation) by fluorescence microscopy. Results: BCPAP showed no significant uptake (<0.1 % per one million cells). The proliferation of BCPAP cells was not significantly influenced by radioiodine incubation. The uptake of NIS-expressing FRTL5 cells ranged between 0.6 % and 4 % per one million cells, independently of the isotope. In FRTL5 cells the incubation with 131I- induced a significant dose-dependent inhibition of proliferation (p<0.05). The positron emitter 124I- induced analogue effects on proliferation compared to the electron emitter 131I- (30-40 % inhibition, 144 h incubation with 400 kBq/ml). In parallel, in FRTL5 cell lines an isotope-independent increase of morphological changes in the cell nuclei (up to 5 fold) could be determined. In contrast, no significant changes could be verified in BCPAP cell nuclei. Conclusions: As expected from the physical point of view, the biological effects of positrons

  1. New Scientific Pearl about Biologic Effect of Ionizing Radiation

    Directory of Open Access Journals (Sweden)

    S. A. Alamdaran

    2008-01-01

    Full Text Available Soon after the discovery of X-ray by Rontgen in 1895, it became evident that radiation can cause some somatic damage to tissues. The hazards of X-ray exposure were clearly known when many large hospitals had radiology departments. The greatest increased in knowledge about X-ray risks had accrued from the dropping of the two atomic bombs in Japan in 1945 and some other atomic accident. For example, among the Japanese bomb survivors from Hiroshima and Nagasaki, there have been about 400 extra cancer deaths. These were the origin of radiology personnel and people fear from radiation exposure and resistant in against simple X-ray exam (radiophobia. However, new scientific data on the effects radiation on survivors, especially about biologic effect of ionizing rays, background radiation exposure, amount of endogenous radiation, hormosis phenomenon and comparison radiation risk with other risk over lifetime are still being continuously revised and risk estimates updated. Fundamentally, this risk is much"nlower than whatever already estimated and it is insignificant in diagnostic domain. Better perception of physician from these instances help to prevent of false radiophobia and to make proper use of diagnostic and therapeutic advantages of ionizing beam.

  2. Triclosan: A Widespread Environmental Toxicant with Many Biological Effects.

    Science.gov (United States)

    Yueh, Mei-Fei; Tukey, Robert H

    2016-01-01

    Triclosan (TCS) is a broad-spectrum antimicrobial agent that has been added to personal care products, including hand soaps and cosmetics, and impregnated in numerous different materials ranging from athletic clothing to food packaging. The constant disposal of TCS into the sewage system is creating a major environmental and public health hazard. Owing to its chemical properties of bioaccumulation and resistance to degradation, TCS is widely detected in various environmental compartments in concentrations ranging from nanograms to micrograms per liter. Epidemiology studies indicate that significant levels of TCS are detected in body fluids in all human age groups. We document here the emerging evidence--from in vitro and in vivo animal studies and environmental toxicology studies--demonstrating that TCS exerts adverse effects on different biological systems through various modes of action. Considering the fact that humans are simultaneously exposed to TCS and many TCS-like chemicals, we speculate that TCS-induced adverse effects may be relevant to human health. PMID:26738475

  3. Scientific projection paper on biologic effects of ionizing radiation

    International Nuclear Information System (INIS)

    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

  4. Biological effects of inhaled radionuclides: summary of ICRP report 31

    International Nuclear Information System (INIS)

    The ICRP Task Group charged with evaluating the hazards associated with inhalation of plutonium and other radionuclides, enumerated the biological responses to inhaled radionuclides, identified tissues and cells at risk, derived risk coefficients for inhaled radionuclides from animal experiments for comparison with human data, and determined an equal effectiveness ratio of alpha emitters relative to beta-gamma emitters. High lung burdens of inhaled radionuclides result in profound structural and functional changes in which the pulmonary capillary endothelial cells are the most prominent cells at risk. Linear and nonlinear models used to evaluate lung cancer data from animal experiments project to risk coefficients between 0.84 and 1600 cases/106 animals/rad. The report concludes that the animal data support the current ICRP lung cancer risk of 2 x 10-3 Sv-1 (400 x 10+H-+H6 rad-1). Comparison of risk coefficients for beta-gamma emitters with those for alpha emitters, obtained using the same models, gave an Equal Effectiveness Ratio of 30 for inhaled alpha-emitting radionuclides. Thus, the experimental data support the ICRP decision to change the quality factor from 10 to 20 for alpha radiation. (H.K.)

  5. Prescribed fire effects on biological control of leafy spurge

    Science.gov (United States)

    Fellows, D.P.; Newton, W.E.

    1999-01-01

    The flea beetle, Aphthona nigriscutis Foudras, is a potentially useful agent for biological control of leafy spurge (Euphorbia esula L.) in grasslands devoted to wildlife conservation. However, effects of other grassland management practices on the persistence and dynamics of flea beetle populations are not well understood. We conducted small plot tests to evaluate 1) the effect of prerelease burning on establishment of A. nigriscutis colonies, and 2) the ability of established A. nigriscutis colonies to survive prescribed fire. More colonies established on plots that were burned prior to beetle release (83% establishment) than on unburned plots (37% establishment), possibly due to litter reduction and baring of the soil surface. However, most colonies established with the aid of fire did not survive past the first generation unless the habitat was otherwise suitable for the species, and we conclude that the primary benefit of prerelease burning is increased recruitment of A. nigriscutis during the first few generations. Established colonies were not harmed by burns in October and May. Both spring and fall burns resulted in an increase in leafy spurge stem density during the first growing season, but stem density declined to the preburn level by the second growing season.

  6. Biological and sanitary effects of non ionizing radiations

    International Nuclear Information System (INIS)

    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.)

  7. Green light effects on biological systems: a new biophysical phenomenon.

    Science.gov (United States)

    Comorosan, Sorin; Kappel, Wilhelm; Constantinescu, Ileana; Gheorghe, Marin; Ionescu, Elena; Pîrvu, Cristian; Cinca, Sabin; Cristache, Ligia

    2009-08-01

    This paper reports a new phenomenon connected with the influence of green light (GL) on biological systems. Our experiments have revealed an antioxidant effect of GL on cells subjected to lethal doses of UV at the cellular level and a protective effect of GL on DNA denatured by UV, coupled with a structural modification of DNA macromolecules under GL irradiation, at the molecular level. Mouse melanocyte cultures are subjected to UV irradiations with L(50) fluxes of 16.0 J m(-2) s(-1). GL is obtained from a strontium aluminate pigment, which emits GL under UV activation. Cells grown in GL, prior to UV irradiation, present a clear surprising protective effect with surviving values close to the controls. A GL antioxidant effect is suggested to be mediated through GL influence on cellular water cluster dynamics. To test this hypothesis, reactive oxygen species (ROS) are determined in cell cultures. The results revealed a decrease of cellular ROS generation in the UV-irradiated samples protected by a previous 24 h of GL irradiation. At the DNA level, the same type of GL protection against UV damage is recorded by gel electrophoresis and by UV spectroscopy of the irradiated DNA molecules. Two physical methods, impedance spectroscopy and chronoamperometry, have revealed at the level of GL-irradiated DNA molecules spectral modifications that correlate with the UV spectroscopy results. The interaction between the chargeless photons and the field of water molecules from the cellular compartments is discussed in relation with the new field of macroscopic quantum coherence phenomena. PMID:19669578

  8. BIOLOGICAL EFFECTS OF PULSED SHORT WAVE TREATMENT. AN EXPERIMENTAL STUDY

    Directory of Open Access Journals (Sweden)

    Dogaru Gabriela

    2015-02-01

    Full Text Available Pulsed short waves are short electromagnetic waves emitted as intermittent trains with a fixed duration, separated by free intervals of variable duration. The biological effects of pulsed short waves could be explained according to most of the authors by an activation of cellular enzymatic reactions, a stimulation of energy metabolism, a stimulation of liver function, of adrenal gland function and of the reticulocyte system, changes in cell permeability, by an increase of peripheral blood flow through the enhancement of local vascularization. This research aimed to investigate the biological effects of exposure to pulsed short waves at different doses on the adrenal glands of experimental animals, by structural and ultrastructural studies. The study included 35 animals assigned to 4 groups. Group I included 10 experimental animals exposed to radiation at a dose of 1/80 impulses/sec, group II, 10 animals exposed to a dose of 4/400 impulses/sec, group III, 10 animals exposed to a dose of 6/600 impulses/sec, for 10 min/day, and the control group consisted of 5 unexposed animals. Structural and ultrastructural changes of adrenal glands induced by the dose of 4/400 impulses/sec, compared to the unexposed control group and the dose of 1/80 impulses/sec, include an intensification of protein synthesis processes, an enhancement of energy metabolism in providing the energy required for an increased production of hormones, an intensification of collagen fiber synthesis processes in the capsule, necessary for healing. It was demonstrated that this dose induced an intensification of hormone synthesis and secretion, a stimulation of adrenal function. At the dose of 6/600 cycles/sec, a slight diminution of hormone synthesis and secretion activity was found, which was not below the limits existing in the unexposed control group, but was comparable to group II. This dose is probably too strong for experimental animals, inducing them a state of stress. The

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

    International Nuclear Information System (INIS)

    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)

  10. Examining the Effect of Multiple Writing Tasks on Year 10 Biology Students' Understandings of Cell and Molecular Biology Concepts

    Science.gov (United States)

    Hand, Brian; Hohenshell, Liesl; Prain, Vaughan

    2007-01-01

    This paper reports on a study that examined the cumulative effects on students' learning of science, and perceptions of the role of writing in learning, when the students engaged in multiple writing tasks with planning strategy support. The study was conducted with Year 10 biology students who completed two consecutive units on Cells and Molecular…

  11. Biological effectiveness of mammalian cells exposed to heavy ion beams

    International Nuclear Information System (INIS)

    The LET-relative biological effectiveness (RBE) spectra were investigated using cultured V79 cells by accelerated heavy ions. Cells were exposed to ''3He-, ''1''2C-, and ''2''0Ne-ion beams at HIMAC, the Medical Cyclotron at NIRS, and RRC at RIKEN with an LET ranging over approximately 10-500 keV/μm under aerobic conditions. Cell-survival curves were fitted by equations from the linear-quadratic model to obtain survival parameters, and the RBE values were analyzed as a function of LET. The RBE increased with LET, reaching a maximum at around 200 keV/μm, then decreased with a further increase in LET. Clear splits of the LET-RBE spectrum were found among ion-spices. The LET-RBE spectra were fitted by a newly contrived equation that including three parameters: LP, A, and W. The parameters will indicate a LET that gives a maximum RBE, a related value to maximum RBE, and indicates the width of the peak of RBE, respectively. It is also found that the parameters can be defined as functions of atomic numbers of the accelerated ions. At a given LET, the RBE-value for lighter ions was higher than that for heavier ions at lower-LET region. The LET that gives maximum RBE shifts to higher LET for heavier-ions, and the maximum values of the peak of RBE decreased with the atomic number of the irradiated ions. (author)

  12. Relative Biological Effectiveness and Peripheral Damage of Antiproton Annihilation

    CERN Multimedia

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

  13. 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.

  14. Biological effectiveness of neutron irradiation on animals and man

    International Nuclear Information System (INIS)

    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, 252Cf-fission, and 15 MeV neutrons, compared with that by 60Co 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

  15. Effect of biological gas generation on oil sand fine tailings

    Energy Technology Data Exchange (ETDEWEB)

    Guo, C.; Chalaturnyk, R.J.; Scott, J.D. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering; MacKinnon, M. [Syncrude Canada Ltd., Edmonton, AB (Canada). Edmonton Research Centre

    2004-07-01

    A field study was conducted to examine the effect of microbial activity on densification of mature fine tailings (MFT) found at the Mildred Lake Settling Basin (MLSB). The MLSB has accumulated 216,000 cubic meters of MFT since Syncrude Canada Limited started production in 1978. Since 1997, there has been a significant change in the consolidation behaviour of the MFT. Methane-producing microorganisms have become very active and large amounts of biogas have been produced. In some regions, gas bubbles are released to the water surface of the tailings pond. Field monitoring of the MLSB has shown evidence of rapid water drainage from the tailings. This phenomenon contradicts the consolidation models for MFT developed over the past 20 years. Although this rapid water draining (or densification) can cause pumping challenges, it can also accelerate the reclamation of the oil sands fine tailings. This study examined the mechanism leading to the rapid densification phenomenon. Systematic field studies were conducted to determine the distribution and characteristics of the rapidly densified MFT. Gas bubble distribution on the water surface was mapped to identify zones of different biological activities in the pond. Several small-scale column tests were carried out to observe the gas evolution and to measure the changes of some geotechnical parameters under different microbial activity. 4 refs., 6 tabs., 12 figs.

  16. Stochastic Effects in Computational Biology of Space Radiation Cancer Risk

    Science.gov (United States)

    Cucinotta, Francis A.; Pluth, Janis; Harper, Jane; O'Neill, Peter

    2007-01-01

    Estimating risk from space radiation poses important questions on the radiobiology of protons and heavy ions. We are considering systems biology models to study radiation induced repair foci (RIRF) at low doses, in which less than one-track on average transverses the cell, and the subsequent DNA damage processing and signal transduction events. Computational approaches for describing protein regulatory networks coupled to DNA and oxidative damage sites include systems of differential equations, stochastic equations, and Monte-Carlo simulations. We review recent developments in the mathematical description of protein regulatory networks and possible approaches to radiation effects simulation. These include robustness, which states that regulatory networks maintain their functions against external and internal perturbations due to compensating properties of redundancy and molecular feedback controls, and modularity, which leads to general theorems for considering molecules that interact through a regulatory mechanism without exchange of matter leading to a block diagonal reduction of the connecting pathways. Identifying rate-limiting steps, robustness, and modularity in pathways perturbed by radiation damage are shown to be valid techniques for reducing large molecular systems to realistic computer simulations. Other techniques studied are the use of steady-state analysis, and the introduction of composite molecules or rate-constants to represent small collections of reactants. Applications of these techniques to describe spatial and temporal distributions of RIRF and cell populations following low dose irradiation are described.

  17. 2.3.2 Biological Effects of Non-Ionizing Radiations

    Science.gov (United States)

    Bernhardt, J. H.

    This document is part of Subvolume A 'Fundamentals and Data in Radiobiology, Radiation Biophysics, Dosimetry and Medical Radiological Protection' of Volume 7 'Medical Radiological Physics' of Landolt-Börnstein - Group VIII 'Advanced Materials and Technologies'. It contains the Subsection '2.3.2 Biological Effects of Non-Ionizing Radiations' of the Section '2.3 Biological Effects' of the Chapter '2 Radiation and Biological Effects' with the contents:

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

    International Nuclear Information System (INIS)

    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. The effect of network biology on drug toxicology

    DEFF Research Database (Denmark)

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

    2013-01-01

    biology has the opportunity to contribute to a better understanding of a drug's safety profile. The authors believe that considering a drug action and protein's function in a global physiological environment may benefit our understanding of the impact some chemicals have on human health and toxicity. The...... 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...

  20. Generic Biologic Drugs Seem as Effective as Originals

    Science.gov (United States)

    ... versions aren't interchangeable with their products. The patents of many brand-name biologics are expiring and ... He's an associate professor in the department of Epidemiology at the Bloomberg School of Public Health, and ...

  1. Effects of abiotic stress on plants: a systems biology perspective

    OpenAIRE

    Cramer Grant R; Urano Kaoru; Delrot Serge; Pezzotti Mario; Shinozaki Kazuo

    2011-01-01

    Abstract The natural environment for plants is composed of a complex set of abiotic stresses and biotic stresses. Plant responses to these stresses are equally complex. Systems biology approaches facilitate a multi-targeted approach by allowing one to identify regulatory hubs in complex networks. Systems biology takes the molecular parts (transcripts, proteins and metabolites) of an organism and attempts to fit them into functional networks or models designed to describe and predict the dynam...

  2. The Effect of Hypoxia on Mesenchymal Stem Cell Biology

    OpenAIRE

    Mostafa Ejtehadifar; Karim Shamsasenjan; Aliakbar Movassaghpour; Parvin Akbarzadehlaleh; Nima Dehdilani; Parvaneh Abbasi; Zahra Molaeipour; Mahshid Saleh

    2015-01-01

    Although physiological and pathological role of hypoxia have been appreciated in mammalians for decades however the cellular biology of hypoxia more clarified in the past 20 years. Discovery of the transcription factor hypoxia-inducible factor (HIF)-1, in the 1990s opened a new window to investigate the mechanisms behind hypoxia. In different cellular contexts HIF-1 activation show variable results by impacting various aspects of cell biology such as cell cycle, apoptosis, diff...

  3. Bone Effects of Biologic Drugs in Rheumatoid Arthritis

    OpenAIRE

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

    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 (TNFα, 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 pract...

  4. 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.

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

    International Nuclear Information System (INIS)

    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

  6. 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

  7. The Role of Non-Targeted Effects as Mediators in the Biological Effects of Proton Irradiation

    Science.gov (United States)

    Cucinotta, Francis A.; Dicello, John F.

    2006-01-01

    In recent years, the hypothesis that non-DNA targets are primary initiators and mediators of the biological effects of ionizing radiation, such as proton beams and heavy ions, has gained much interest. These phenomena have been denoted as non-targeted or bystander effects to distinguish them from the more traditionally studied model that focuses on direct damage to DNA causing chromosomal rearrangements and mutations as causative of most biological endpoints such as cell killing, tissue damage, and cancer. We review cellular and extra-cellular structures and signal transduction pathways that have been implemented in these recent studies. Non-targeted effects of interest include oxidative damage to the cytoplasm and mitochondria, disruption of the extra-cellular matrix, and modification of cytokine signaling including TGF-beta, and gap junction communication. We present an introduction to these targets and pathways, and contrast there role with DNA damage pathways.

  8. 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 vocabulary terms, physical characteristics, and types of evidence used to classify. Both groups extended their understanding, but only POGIL students could explain how molecular evidence is used in classification. 2) The challenges preventing students from understanding classification were: 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.

  9. Radon exposure of the skin: I. Biological effects

    Energy Technology Data Exchange (ETDEWEB)

    Charles, M W [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)

    2007-09-15

    Radon progeny can plate out on skin and give rise to exposure of the superficial epidermis from alpha emitters Po-218 (7.7 MeV, range {approx}66 {mu}m) and Po-214 (6 MeV, range {approx}44 {mu}m). Dose rates from beta/gamma emitters Pb-214 and Bi-214 are low and only predominate at depths in excess of the alpha range. This paper reviews the evidence for a causal link between exposure from radon and its progeny, and deterministic and stochastic biological effects in human skin. Radiation induced skin effects such as ulceration and dermal atrophy, which require irradiation of the dermis, are ruled out for alpha irradiation from radon progeny because the target cells are considerably deeper than the range of alpha particles. They have not been observed in man or animals. Effects such as erythema and acute epidermal necrosis have been observed in a few cases of very high dose alpha particle exposures in man and after acute high dose exposure in animals from low energy beta radiations with similar depth doses to radon progeny. The required skin surface absorbed doses are in excess of 100 Gy. Such effects would require extremely high levels of radon progeny. They would involve quite exceptional circumstances, way outside the normal range of radon exposures in man. There is no definitive identification of the target cells for skin cancer induction in animals or man. The stem cells in the basal layer which maintain the epidermis are the most plausible contenders for target cells. The majority of these cells are near the end of the range of radon progeny alpha particles, even on the thinnest body sites. The nominal depth of these cells, as recommended by the International Commission on Radiological Protection (ICRP), is 70 {mu}m. There is evidence however that some irradiation of the hair follicles and/or the deeper dermis, as well as the inter-follicular epidermis, is also necessary for skin cancer induction. Alpha irradiation of rodent skin that is restricted to the

  10. Radon exposure of the skin: I. Biological effects

    International Nuclear Information System (INIS)

    Radon progeny can plate out on skin and give rise to exposure of the superficial epidermis from alpha emitters Po-218 (7.7 MeV, range ∼66 μm) and Po-214 (6 MeV, range ∼44 μm). Dose rates from beta/gamma emitters Pb-214 and Bi-214 are low and only predominate at depths in excess of the alpha range. This paper reviews the evidence for a causal link between exposure from radon and its progeny, and deterministic and stochastic biological effects in human skin. Radiation induced skin effects such as ulceration and dermal atrophy, which require irradiation of the dermis, are ruled out for alpha irradiation from radon progeny because the target cells are considerably deeper than the range of alpha particles. They have not been observed in man or animals. Effects such as erythema and acute epidermal necrosis have been observed in a few cases of very high dose alpha particle exposures in man and after acute high dose exposure in animals from low energy beta radiations with similar depth doses to radon progeny. The required skin surface absorbed doses are in excess of 100 Gy. Such effects would require extremely high levels of radon progeny. They would involve quite exceptional circumstances, way outside the normal range of radon exposures in man. There is no definitive identification of the target cells for skin cancer induction in animals or man. The stem cells in the basal layer which maintain the epidermis are the most plausible contenders for target cells. The majority of these cells are near the end of the range of radon progeny alpha particles, even on the thinnest body sites. The nominal depth of these cells, as recommended by the International Commission on Radiological Protection (ICRP), is 70 μm. There is evidence however that some irradiation of the hair follicles and/or the deeper dermis, as well as the inter-follicular epidermis, is also necessary for skin cancer induction. Alpha irradiation of rodent skin that is restricted to the epidermis does not

  11. 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.

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

    International Nuclear Information System (INIS)

    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)

  13. Biological challenges to effective vaccines in the developing world.

    Science.gov (United States)

    Grassly, Nicholas C; Kang, Gagandeep; Kampmann, Beate

    2015-06-19

    The reason for holding a meeting to discuss biological challenges to vaccines is simple: not all vaccines work equally well in all settings. This special issue reviews the performance of vaccines in challenging environments, summarizes current thinking on the reasons why vaccines underperform and considers what approaches are necessary to understand the heterogeneity in responses and to improve vaccine immunogenicity and efficacy. PMID:25964451

  14. Biological challenges to effective vaccines in the developing world

    OpenAIRE

    Grassly, Nicholas C.; Kang, Gagandeep; Kampmann, Beate

    2015-01-01

    The reason for holding a meeting to discuss biological challenges to vaccines is simple: not all vaccines work equally well in all settings. This special issue reviews the performance of vaccines in challenging environments, summarizes current thinking on the reasons why vaccines underperform and considers what approaches are necessary to understand the heterogeneity in responses and to improve vaccine immunogenicity and efficacy.

  15. ICBEN review of research on the biological effects of noise 2011-2014

    OpenAIRE

    Mathias Basner; Mark Brink; Abigail Bristow; Yvonne de Kluizenaar; Lawrence Finegold; Jiyoung Hong; Sabine A Janssen; Ronny Klaeboe; Tony Leroux; Andreas Liebl; Toshihito Matsui; Dieter Schwela; Mariola Sliwinska-Kowalska; Patrik Sörqvist

    2015-01-01

    The mandate of the International Commission on Biological Effects of Noise (ICBEN) is to promote a high level of scientific research concerning all aspects of noise-induced effects on human beings and animals. In this review, ICBEN team chairs and co-chairs summarize relevant findings, publications, developments, and policies related to the biological effects of noise, with a focus on the period 2011-2014 and for the following topics: Noise-induced hearing loss; nonauditory effects of noise; ...

  16. Effectiveness and drug adherence of biologic monotherapy in routine care of patients with rheumatoid arthritis

    DEFF Research Database (Denmark)

    Jorgensen, Tanja Schjodt; Kristensen, Lars Erik; Christensen, Robin;

    2015-01-01

    OBJECTIVES: To estimate the prevalence of Danish RA patients currently on biologic monotherapy and compare the effectiveness and drug adherence of biologic therapies applied as monotherapy. METHODS: All RA patients registered in the Danish biologics database (DANBIO) as receiving biologic DMARD (b...... for prevalence, effectiveness and drug adherence of bDMARD monotherapy were calculated. RESULTS: Of the 775 patients on bDMARD monotherapy, adalimumab (21.3%), etanercept (36.6%) and tocilizumab (15.3%) were the most prevalent biologic agents administered. At the 6-month follow-up, the overall crude...... clinical disease activity index remission rate in patients still on a biologic drug was 22%, the 28-joint DAS remission rate was 41% and the response rate of those with a 50% improvement in ACR criteria was 28%. At the 6-month follow-up, the drug adherence rates were similar for the different bDMARDs, with...

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

    International Nuclear Information System (INIS)

    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. Effects on bone metabolism of new therapeutic strategies with standard chemotherapy and biologic drugs

    OpenAIRE

    Ciolli, Stefania

    2013-01-01

    Recent biological advances have provided the framework for novel therapeutic strategies in oncology. Many new treatments are now based on standard cytotoxic drugs plus biologic agents. In Multiple Myeloma, a plasma cell neoplasm characterized by a severe bone disease, biologic drugs such as proteasome inhibitors and immunomodulatory agents, above their antineoplastic efficacy have a beneficial effects on bone disease. Bortezomib, a clinically available proteasome inhibitor active against myel...

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

    OpenAIRE

    Snezana Stavrova Veselinovskaa

    2011-01-01

    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 Lab...

  20. Five task clusters that enable efficient and effective digitization of biological collections

    OpenAIRE

    Gil Nelson; Deborah Paul; Greg Riccardi; Austin Mast

    2012-01-01

    Abstract This paper describes and illustrates five major clusters of related tasks (herein referred to as task clusters) that are common to efficient and effective practices in the digitization of biological specimen data and media. Examples of these clusters come from the observation of diverse digitization processes. The staff of iDigBio (The U.S. National Science Foundation’s National Resource for Advancing Digitization of Biological Collections) visited active biological and paleontologic...

  1. The long-term fertilization effect on biological activity of different genesis soils

    OpenAIRE

    Grigaliūnienė, Kristina

    2006-01-01

    The effect of organic and mineral fertilizers on biological activity of different genesis soils in long-term crop rotation trials was determined. Biological activity was diverse in the soils of different genesis and it activity correlated with some soil chemical properties. Organic and mineral fertilizers and their combinations more increased biological activity in the soil than only mineral fertilizers. Mineral fertilizers suppressed dehydrogenase and alkaline phosphatase activity (180 kg ha...

  2. Effect of biologic agents on radiographic progression of rheumatoid arthritis

    OpenAIRE

    Devauchelle, Valerie

    2010-01-01

    Gabriel J Tobón1, Alain Saraux1,2, Valérie Devauchelle-Pensec1,21Immunology Laboratory, Morvan Hospital, Université de Bretagne Occidentale, Brest, France; 2Rheumatology Unit, Hôpital de la Cavale Blanche, CHU Brest, FranceAbstract: The treatment of rheumatoid arthritis (RA) has benefited over the last few years from the introduction of biologic agents whose development was based on new insights into the immunological factors involved in the pathogen...

  3. Resurrecting the body: Has portmodernism had any effect on biology?

    Science.gov (United States)

    Gilbert, S F

    1995-01-01

    While postmodernism has had very little influence in biology (for reasons discussed in the paper), it can provide a framework for discussing the context in which biology is done. Here, four biological views of the body/self are contrasted: the neural, immunological, genetic, and phenotypic bodies. Each physical view of the body extrapolates into a different model of the body politic, and each posits a different relationship between bodies of knowledge. The neural view of the body models a body politic wherein society is defined by its culture and laws. The genetic view privileges views of polities based on ethnicity and race. The immune body extrapolates into polities that can defend themselves against other such polities. The phenotypic view of the body politic stands in opposition to these three major perspectives and integrates them without giving any predominance. The view of science as a "neural" body of knowledge contends that science is aperspectival and objective. The perspective of the "immune" body is that science exists to defend the interests of its creataors. The genetic view of science is that science is the basis of all culture. The extrapolation of the phenotypic body to science insists upon the utilitarian rationale for scientific interprises. In all instances, the genetic view of the body/body politic/body of science is presently in ascendance. PMID:11613273

  4. Teachers' perceptions of the effects of a scientific literary course on subsequent learning in biology

    Science.gov (United States)

    Baker, Dale R.; Piburn, Michael D.; Piburn, Michael D.

    Five teachers were interviewed as to their perceptions of the effect of an intervention to teach scientific literacy on learning in subsequent biology courses. The sample consisted of 450 students who had a literacy course in ninth grade and had completed tenth-grade biology. At the end of the academic year the biology teachers were interviewed and asked to compare the biology students who had the literacy course to students they had taught in earlier years. The biology teachers concluded that the literacy course did have an effect on students' subsequent ability to learn biology. The strength of the effect varied according to level of biology. Students had a better understanding of the nature of science and better laboratory and process skills. They were also better at analyzing data. The advanced and intermediate biology students were more creative, more likely to take risks, and engage in hypothetical thinking than other groups of students that the teachers had taught. Although the purpose of the literacy course was to teach literacy skills the advanced students retained a substantial amount of content material that was applicable to biology.

  5. Size Matters: Molecular Weight Specificity of Hyaluronan Effects in Cell Biology

    OpenAIRE

    Jaime M. Cyphert; Trempus, Carol S.; Stavros Garantziotis

    2015-01-01

    Hyaluronan signaling properties are unique among other biologically active molecules, that they are apparently not influenced by postsynthetic molecular modification, but by hyaluronan fragment size. This review summarizes the current knowledge about the generation of hyaluronan fragments of different size and size-dependent differences in hyaluronan signaling as well as their downstream biological effects.

  6. 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,…

  7. Biological effects of air pollution in Sao Paulo and Cubatao

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, G.M.S.; Saldiva, P.H.; Pasqualucci, C.A.; Massad, E.; Martins M de, E.; Zin, W.A.; Cardoso, W.V.; Criado, P.M.; Komatsuzaki, M.; Sakae, R.S. (Instituto do Coracao, Faculdade de Medicina da USP, Sao Paulo (Brazil))

    1989-08-01

    Rats were used as biological indicators of air quality in two heavily polluted Brazilian towns: Sao Paulo and Cubatao. They were exposed for 6 months to ambient air in areas where the pollution was known to be severe. The following parameters were studied and compared to those of control animals: respiratory mechanics, mucociliary transport, morphometry of respiratory epithelium and distal air spaces, and general morphological alterations. The results showed lesions of the distal and upper airways in rats exposed in Cubatao, whereas the animals from Sao Paulo showed only alterations of the upper airways but of greater intensity than those observed in the Cubatao group. There are both qualitative and quantitative differences in the pollutants of these places: in Sao Paulo automobile exhaust gases dominate and in Cubatao the pollution is due mainly to particulates of industrial sources. The correlation of the pathological findings with the pollutants is discussed and it is concluded that biological indicators are useful to monitor air pollutions which reached dangerous levels in Sao Paulo and Cubatao.

  8. Biological effects of radiation in combination with other physical, chemical or biological agents. Annex L

    International Nuclear Information System (INIS)

    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

  9. 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.

  10. Dehydroepiandrosterone biosynthesis, metabolism, biological effects, and clinical use (analytical review

    Directory of Open Access Journals (Sweden)

    N. P. Goncharov

    2015-04-01

    Full Text Available The review presents the fundamental information on the metabolism of dehydroepiandrosterone (DHEA, its biological role and possibilities of its use for replacement therapy. There were studied species differences in the synthesis of DHEA in the adrenal cortex. It was found that DHEA and DHEA-sulfate are produced only by the adrenal glands of humans and monkeys, including lower monkeys. Their biosynthesis involves the following steps: cholesterol → pregnenolone → 17-hydroxypregnenolone → DHEA. The adrenal glands of other species, including rats and mice do not synthesize DHEA. At the same time, in certain brain structures not only in man and monkey, but also in other animals DHEA and its precursors are synthesized de novo which are denoted as neurosteroids. It was demonstrated that Purkinje cells which play an important role in memory formation and learning are mainly place neurosteroid formation in mammals and other vertebrates. To establish the relationship of age and the level of DHEA and other steroids we studied the dynamics of their levels at different periods of postnatal development of people. Peak concentration DHEA observed in aged 25–30 years. In the interval from 20 to 90 years in humans the level falls approximately for 90 %. Cortisol levels in blood does not vary with age, leading to an imbalance in the ratio of cortisol/DHEA. Proved a major role of DHEA as a source (precursor for the synthesis of biologically active sex steroids – testosterone, estradiol and estrone in peripheral tissues. This review presents the bioavailability of DHEA in various physiological and pathological processes in humans and animals. In animal experiments has shown a higher bioavailability of DHEA in transdermal administration as compared with oral administration as in this case there is no steroid rapid inactivation in the liver during its first passage. According to recent studies there is a pronounced dependence of bioavailability of DHEA

  11. An integrated strategy for biological effects monitoring in Scottish coastal waters

    International Nuclear Information System (INIS)

    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)

  12. Characterization of PAH-contaminated soils focusing on availability, chemical composition and biological effects

    OpenAIRE

    Bergknut, Magnus

    2006-01-01

    The risks associated with a soil contaminated by polycyclic aromatic hydrocarbons (PAHs) are generally assessed by measuring individual PAHs in the soil and correlating the obtained amounts to known adverse biological effects of the PAHs. The validity of such a risk estimation is dependent on the presence of additional compounds, the availability of the compounds (including the PAHs), and the methods used to correlate the measured chemical data and biological effects. In the work underlying t...

  13. Untangling the biological effects of cerium oxide nanoparticles: the role of surface valence states

    OpenAIRE

    Gerardo Pulido-Reyes; Ismael Rodea-Palomares; Soumen Das; Tamil Selvan Sakthivel; Francisco Leganes; Roberto Rosal; Sudipta Seal; Francisca Fernández-Piñas

    2015-01-01

    Cerium oxide nanoparticles (nanoceria; CNPs) have been found to have both pro-oxidant and anti-oxidant effects on different cell systems or organisms. In order to untangle the mechanisms which underlie the biological activity of nanoceria, we have studied the effect of five different CNPs on a model relevant aquatic microorganism. Neither shape, concentration, synthesis method, surface charge (ζ-potential), nor nominal size had any influence in the observed biological activity. The main drive...

  14. 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.

  15. 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.

  16. III. Biological effects of radiation from external and internal sources

    Energy Technology Data Exchange (ETDEWEB)

    Stone, R.S.

    1948-05-24

    This report focuses on the hemotological effects of total body irradiation from external and internal sources observed in patients treated for arthritis with radioactive phosphorus administered intravenously.

  17. Effects of membrane disruption on dielectric properties of biological cells

    International Nuclear Information System (INIS)

    Disruption of the plasma membrane causes serious changes in the dielectric properties of biological cells. The changes have been simulated with spherical cell models having holes in the plasma membrane. The complex permittivity of a cubic system including a cell model was calculated by a numerical technique based on the three-dimensional finite difference method. For a cell without hole, the complex permittivity showed dielectric relaxation (β-dispersion) as predicted from interfacial polarization theories for the single-shell model. When there is one hole in the membrane, the cell has anisotropic dielectric properties depending on whether the axis through the centres of the hole and the sphere is parallel (the parallel orientation) or perpendicular (the perpendicular orientation) to the electric field direction. In the parallel orientation, dielectric relaxation (called 'α-dispersion') appeared at lower frequencies in addition to the β-dispersion, whereas only the β-dispersion was found in the perpendicular orientation. When there were two holes at the opposite poles of the cell, the 'α-dispersion' did not appear and the intensity of the β-dispersion decreased with increasing size of the holes. When two holes located in the hemisphere of the cell, however, the 'α-dispersion' appeared again. These results suggest that the occurrence of the 'α-dispersion' requires either the presence of one hole or the localization of holes

  18. Solar activity, magnetic storms and their effects on biological systems

    International Nuclear Information System (INIS)

    Full text: In the present time much attention is spent on the electromagnetic waves, solar radiation and magnetic storms on biological systems, including on person. However, there are few publications describing the mechanism of these influences on human. First of all it is necessary to point out that electromagnetic waves, the flow of particles in space and magnetic storms, acting on person human-all is connected with biophysical processes. So approach to influence of these factors on organism follows the processes of influence of these waves on bio system. Magnetic storms are phenomena continuously connected with solar activity. Investigation of cosmic space has intensified the practical importance of the problem of interaction with natural factors of external ambience. Much attention deserves the cosmic radiation, geomagnetic field, elements of climate and weathers. However the mechanism of bio tropic action of these factors is not enough studied. Beginning XXI century was already signified the successes in investigation of Mars. The Space shuttles 'Spirit' and 'Opportunity' successfully have carried out some work on examining and finding of water on Mars. A flight of person to Mars is being considered. One of the important mechanisms of influence on human organism is, in our opinion, the rising of the resonance at coincidence of frequencies and their more important factor is a phenomena of electromagnetic induction and forming the radicals in the organism

  19. “The Biological Effects of Childhood Trauma”

    OpenAIRE

    De Bellis, Michael D.; A.B., Abigail Zisk

    2014-01-01

    Trauma in childhood is a grave psychosocial, medical, and public policy problem that has serious consequences for its victims and for society. Chronic interpersonal violence in children is common worldwide. Developmental traumatology, the systemic investigation of the psychiatric and psychobiological effects of chronic overwhelming stress on the developing child, provides a framework and principles when empirically examining the neurobiological effects of pediatric trauma.

  20. Lung Deposition And Biological Effects Of Inhaled Radon Progenies

    International Nuclear Information System (INIS)

    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

  1. Relative biological effectiveness (RBE) of proton beams in radiotherapy

    International Nuclear Information System (INIS)

    Treatment planning in proton therapy uses a generic value for the Relative Biological Efficiency (RBE) of 1.1 relative to 60Co 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 137Cs gamma-rays and did not vary significantly. The incidence of DSBs and clustered lesions was higher for protons than for 137Cs 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)

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

    International Nuclear Information System (INIS)

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

  3. Examining the effects of students' classroom expectations on undergraduate biology course reform

    Science.gov (United States)

    Hall, Kristi Lyn

    In this dissertation, I perform and compare three studies of introductory biology students' classroom expectations -- what students expect to be the nature of the knowledge that they are learning, what they think they should be (or are) doing in order to learn, and what they think they should be (or are) doing in order to be successful. Previous work has shown that expectations can impact how students approach learning, yet biology education researchers have been reluctant to acknowledge or address the effects of student expectations on curricular reform (NRC, 2012). Most research in biology education reform has focused on students' conceptual understandings of biology and the efficacy of specific changes to content and pedagogy. The current research is lacking a deeper understanding of how students perceive the classroom environment and how those perceptions can shape students' interactions with the content and pedagogy. For present and future reforms in biology to reach their full potential, I argue that biology education should actively address the different ways students think about and approach learning in biology classes. The first study uses a Likert-scale instrument, adapted from the Maryland Physics Expectations Survey (Redish, Saul, & Steinberg, 1998). This new survey, the Maryland Biology Expectations Survey (MBEX) documents two critical results in biology classrooms: (i) certain student-centered pedagogical contexts can produce favorable changes in students' expectations, and (ii) more traditional classroom contexts appear to produce negative epistemological effects. The second study utilizes a modified version of the MBEX and focuses on students' interdisciplinary views. This study documents that: (i) biology students have both discipline-specific and context-specific classroom expectations, (ii) students respond more favorably to interdisciplinary content in the biology courses we surveyed (as opposed to biology content introduced into the physics

  4. STUDENTS’ PERCEPTION AND PERCEIVED EFFECTIVENESS TOWARD e-AV BIOLOGY COURSEWARE FOR LEARNING ABOUT RENEWABLE ENERGY

    Directory of Open Access Journals (Sweden)

    Siti Hadiati Nugraini*

    2015-02-01

    Full Text Available The teaching media namely e-AV Biology, was developed with the main features of video lessons in supporting the students’ learning process. Some video lessons describe the production process of Bio-fuel or Renewable Energy on the field of Biotechnology Industrial, which is one of the subjects that students and teachers find it difficult to learn and explain. The design and development of a Courseware for Biology in senior high schools in Indonesia is described in this paper. The context of Biology education in Indonesia shows that the students’ motivation in learning this subject is considered low. Moreover, students have difficulties in learning Biology and have no interest in the lesson due to the subject irrelevant with the daily experiences, and Biology teachers in Indonesia were still using the monotonous teaching method, teachers are the focal point of learning in the classroom. The methodology used in this study was quasi experimental research. There were two groups involved in this experiment, namely: T0 and T1. The first group (T0 was assigned as the control group and the second group (T1 was assigned to the experiment group. Two objectives were identified, firstly to design and develop the e-AV Biology Courseware that can be used as a teaching medium. Secondly, it examined the impact on students’ perception and perceived effectiveness of high and low academic achievement when the e-AV Biology Courseware is used. The findings of study indicated that the eAV Biology Courseware was able to help students to understand more about the Biology subject compared to the conventional ways of teaching. The students who learn Biology using the e-AV Biology Courseware have more interest, better perception and perceived effectiveness toward the subject. Most of the students who participated in this experiment responded positively and suggested that the video lesson should be added to their Biology subject in their schools. The study suggested

  5. Biological effects of pesticides on rats treated with carbon tetrachloride

    International Nuclear Information System (INIS)

    The present study investigates the effect of repeated oral doses of the organophosphorus pesticide, cytrolane on normal and pretreated rate with different oral doses of carbon tetrachloride. For that purpose the effect of cytrolane, CCl4 and their potential interaction had been studied on brain and erythrocyte acetylcholinesterase (Ache), plasma cholinesterase (Ch E), liver succinic dehydrogenase (SDH), serum alkaline phosphatase (SAP), liver succinic dehydrogenas (SDH), serum alkaline phosphatase (SAP), glutamic oxaloacetic (GOT) and glutamic pyruvic (GPT) transaminases. It also investigates the effect of an acute oral dose of cytrolane at short time intervals (1/2-24 hours) on brain and blood ache of normal and pretreated rate with a single oral dose of CCl4. The distribution and excretion of 14cc14 at different time intervals (2,6 and 24 hours) in normal rats and in rats pretreated with o.89 mg cytrolane/kg/day for a week had been determined in different organs, expired air, urine and faeces

  6. Which chemicals drive biological effects in wastewater and recycled water?

    Science.gov (United States)

    Tang, Janet Y M; Busetti, Francesco; Charrois, Jeffrey W A; Escher, Beate I

    2014-09-01

    Removal of organic micropollutants from wastewater during secondary treatment followed by reverse osmosis and UV disinfection was evaluated by a combination of four in-vitro cell-based bioassays and chemical analysis of 299 organic compounds. Concentrations detected in recycled water were below the Australian Guidelines for Water Recycling. Thus the detected chemicals were considered not to pose any health risk. The detected pesticides in the wastewater treatment plant effluent and partially advanced treated water explained all observed effects on photosynthesis inhibition. In contrast, mixture toxicity experiments with designed mixtures containing all detected chemicals at their measured concentrations demonstrated that the known chemicals explained less than 3% of the observed cytotoxicity and less than 1% of the oxidative stress response. Pesticides followed by pharmaceuticals and personal care products dominated the observed mixture effects. The detected chemicals were not related to the observed genotoxicity. The large proportion of unknown toxicity calls for effect monitoring complementary to chemical monitoring. PMID:24874944

  7. Effect of solids retention time and wastewater characteristics on biological phosphorus removal

    DEFF Research Database (Denmark)

    Henze, Mogens; Aspegren, H.; Jansen, J.l.C.; Nielsen, P.H.; Lee, N.

    2002-01-01

    The paper deals with the effect of wastewater, plant design and operation in relation to biological nitrogen and phosphorus removal and the possibilities to model the processes. Two Bio-P pilot plants were operated for 2.5 years in parallel receiving identical wastewater. The plants had SRT of 4...... significant variations with time which has importance in relation to modelling. The overall conclusion of the comparison between the two plants is that the biological phosphorus removal efficiency under practical operating conditions is affected by the SRT in the plant and the wastewater composition. Thus...... valuable in verification of models for Nitrogen and Enhanced Biological Phosphorus Removal....

  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)

    Preparation of chitosan oligomer by radiation degradation was carried out on the gamma Co-60 source. The radiation degradation yield (Gd) 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. 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)

  11. 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...

  12. Encapsulation of clozapine in polymeric nanocapsules and its biological effects.

    Science.gov (United States)

    Łukasiewicz, Sylwia; Szczepanowicz, Krzysztof; Podgórna, Karolina; Błasiak, Ewa; Majeed, Nather; Ogren, Sven Ove Ögren; Nowak, Witold; Warszyński, Piotr; Dziedzicka-Wasylewska, Marta

    2016-04-01

    Clozapine is an effective atypical antipsychotic drug that unfortunately exhibits poor oral bioavailability. Moreover, the clinical use of the compound is limited because of its numerous unfavorable and unsafe side effects. Therefore, the aim of the present study was the development of a new nanocarrier for a more effective clozapine delivery. Here, clozapine was encapsulated into polymeric nanocapsules (NCs). Polyelectrolyte multilayer shells were constructed by the technique of sequential adsorption of polyelectrolytes (LbL) using biocompatible polyanion PGA (Poly-L-glutamic acid, sodium salt) and polycation PLL (poly-L-lysine) on clozapine-loaded nanoemulsion cores. Pegylated external layers were prepared using PGA-g-PEG (PGA grafted by PEG (polyethylene glycol)). Clozapine was successfully loaded into the PLL-PGA nanocarriers (CLO-NCs) with an average size of 100 nm. In vitro analysis of the interactions of the CLO-NCs with the cells of the mononuclear phagocytic system (MPS) was conducted. Cell biocompatibility, phagocytosis potential, and cellular uptake were studied. Additionally, the biodistribution and behavioral effects of the encapsulated clozapine were also studied. The results indicate that surface modified (by PEG grafting) polymeric PLL-PGA CLO-NCs are very promising nanovehicles for improving clozapine delivery. PMID:26774571

  13. 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...

  14. Biologically effective surface UV climatology at Rome and Aosta, Italy

    Science.gov (United States)

    Siani, Anna Maria; Modesti, Sarah; Casale, Giuseppe Rocco; Diemoz, Henri; Colosimo, Alfredo

    2013-05-01

    Given the beneficial and harmful effects of UV radiation on human health, our study aims to provide a characterization of erythemal and vitamin D dose rates at two Italian sites, Rome and Aosta, subject to quite different environmental conditions. Based on the respective UV climatologies, exposure times needed to induce erythema or vitamin D photoproduction are provided as a function of the UV index.

  15. Physical Effects of Buckwheat Extract on Biological Membrane In Vitro and Its Protective Properties

    OpenAIRE

    Włoch, Aleksandra; Strugała, Paulina; Pruchnik, Hanna; Żyłka, Romuald; Oszmiański, Jan; Kleszczyńska, Halina

    2015-01-01

    Buckwheat is a valuable source of many biologically active compounds and nutrients. It has properties that reduce blood cholesterol levels, and so reduces the risk of atherosclerosis, seals the capillaries, and lowers blood pressure. The aim of the study was to determine quantitative and qualitative characteristics of polyphenols contained in extracts from buckwheat husks and stalks, the biological activity of the extracts, and biophysical effects of their interaction with the erythrocyte mem...

  16. Effects of biologically produced surfactants on the mobility and biodegradation of petroleum hydrocarbons

    OpenAIRE

    Falatko, David M.

    1991-01-01

    A laboratory investigation was conducted to determine the effects of biologically produced surfactants (biosurfactants) on petroleum hydrocarbons and their potential for the removal of hydrocarbons from groundwater systems. Bioaurfactanta have been found to be produced by microorganisms during growth on insoluble substrates for the purpose of increasing substrate solubility so as to promote biological degradation. In this study, three types of biosurfactants were produced b...

  17. Heavy water effects on the structure, functions and behavior of biological systems

    International Nuclear Information System (INIS)

    The H2O substitution for D2O either in environment or in the culture medium of the living systems generates changes in their main functions and composition. In this paper some of the heavy water effects in biological systems such as structural and functional changes were reviewed: normal cell architecture alterations, cell division and membrane functions disturbance, muscular contractility and the perturbations of biological oscillators such as circadian rhythm, heart rate, respiratory cycle, tidal and ultradian rhythm. (authors)

  18. Biological effects from electromagnetic fields: Research progress and exposure measurements

    International Nuclear Information System (INIS)

    Although it is commonly accepted that exposure to high levels of electromagnetic, micro- and radiofrequency waves produces harmful effects to the health of man, the formulation of exposure limits is still an open process and dependent upon the evolving level of knowledge in this field. This paper surveys the current level of knowledge gained through 'in vitro' and 'in vivo' radiological and epidemiological studies on different types of electromagnetic radiation derived effects - chromosomal, mutagenic, carcinogenic. It then reviews efforts by international organizations, e. g., the International Radiation Protection Association, to establish exposure limits for radiofrequency electromagnetic fields. Brief notes are given on the electromagnetic radiation monitoring campaign being performed by public health authorities in the Lazio Region of Italy

  19. Biologic discussions augmenting radiation effects and model systems

    International Nuclear Information System (INIS)

    It appears that there is a great deal of indirect evidence that hypoxic cells exist in human tumors, and that they affect the dose of radiation required to control the tumor. Given a suitable method for decreasing the effect of hypoxic cells the way is open to the possible use of lower doses of radiation. This should decrease complication rates, or allow an increased volume to be treated and a consequent increase in control rates

  20. Radioactivity in the ocean: laws and biological effects

    Energy Technology Data Exchange (ETDEWEB)

    Hunsaker, C.T.

    1985-01-01

    This paper summarizes the literature on US laws and international agreements, experimental and monitoring data, and ongoing studies to provide background information for environmental assessment and regulatory compliance activities for ocean dumping of low-level radioactive waste. The Marine Protection, Research, and Sanctuaries Act is the major US legislation governing ocean disposal of radioactive waste. The major international agreement on ocean dumping is the Convention on the Prevention of Marine Pollution by Dumping of Wastes and other Matter. The United States ended its ocean dumping of radioactive wastes in 1970, but other countries have continued ocean dumping under international supervision in the northeast Atlantic. Monitoring of former US disposal sites has neither revealed significant effects on marine biota nor indicated a hazard to human health. Also, no effects on marine organisms have been found that could be attributed to routine discharges into the Irish Sea from the Windscale reprocessing plant. We must improve our ability to predict the oceanic carrying capacity and the fate and effects of ionizing radiation in the marine environment.

  1. Potential biological and ecological effects of flickering artificial light.

    Science.gov (United States)

    Inger, Richard; Bennie, Jonathan; Davies, Thomas W; Gaston, Kevin J

    2014-01-01

    Organisms have evolved under stable natural lighting regimes, employing cues from these to govern key ecological processes. However, the extent and density of artificial lighting within the environment has increased recently, causing widespread alteration of these regimes. Indeed, night-time electric lighting is known significantly to disrupt phenology, behaviour, and reproductive success, and thence community composition and ecosystem functioning. Until now, most attention has focussed on effects of the occurrence, timing, and spectral composition of artificial lighting. Little considered is that many types of lamp do not produce a constant stream of light but a series of pulses. This flickering light has been shown to have detrimental effects in humans and other species. Whether a species is likely to be affected will largely be determined by its visual temporal resolution, measured as the critical fusion frequency. That is the frequency at which a series of light pulses are perceived as a constant stream. Here we use the largest collation to date of critical fusion frequencies, across a broad range of taxa, to demonstrate that a significant proportion of species can detect such flicker in widely used lamps. Flickering artificial light thus has marked potential to produce ecological effects that have not previously been considered. PMID:24874801

  2. Radioactivity in the ocean: laws and biological effects

    International Nuclear Information System (INIS)

    This paper summarizes the literature on US laws and international agreements, experimental and monitoring data, and ongoing studies to provide background information for environmental assessment and regulatory compliance activities for ocean dumping of low-level radioactive waste. The Marine Protection, Research, and Sanctuaries Act is the major US legislation governing ocean disposal of radioactive waste. The major international agreement on ocean dumping is the Convention on the Prevention of Marine Pollution by Dumping of Wastes and other Matter. The United States ended its ocean dumping of radioactive wastes in 1970, but other countries have continued ocean dumping under international supervision in the northeast Atlantic. Monitoring of former US disposal sites has neither revealed significant effects on marine biota nor indicated a hazard to human health. Also, no effects on marine organisms have been found that could be attributed to routine discharges into the Irish Sea from the Windscale reprocessing plant. We must improve our ability to predict the oceanic carrying capacity and the fate and effects of ionizing radiation in the marine environment

  3. Potential biological and ecological effects of flickering artificial light.

    Directory of Open Access Journals (Sweden)

    Richard Inger

    Full Text Available Organisms have evolved under stable natural lighting regimes, employing cues from these to govern key ecological processes. However, the extent and density of artificial lighting within the environment has increased recently, causing widespread alteration of these regimes. Indeed, night-time electric lighting is known significantly to disrupt phenology, behaviour, and reproductive success, and thence community composition and ecosystem functioning. Until now, most attention has focussed on effects of the occurrence, timing, and spectral composition of artificial lighting. Little considered is that many types of lamp do not produce a constant stream of light but a series of pulses. This flickering light has been shown to have detrimental effects in humans and other species. Whether a species is likely to be affected will largely be determined by its visual temporal resolution, measured as the critical fusion frequency. That is the frequency at which a series of light pulses are perceived as a constant stream. Here we use the largest collation to date of critical fusion frequencies, across a broad range of taxa, to demonstrate that a significant proportion of species can detect such flicker in widely used lamps. Flickering artificial light thus has marked potential to produce ecological effects that have not previously been considered.

  4. Biological effects of electromagnetic radiations - 7. International Conference, La Valette, Malta, 8-12 October 2012

    International Nuclear Information System (INIS)

    This document proposes a synthesis of a conference on the biological effects of electromagnetic radiations. With reference to epidemiological studies, different issues have been addressed: pathological effects (either of static fields, or of extremely low frequencies, or of radio-frequencies), biological effects (methodological issues, case of extremely low frequencies and of radio-frequencies), medical applications of electromagnetic fields (tumour removal, neurological disorders, consolidation, wound healing and recovery), assessment of electromagnetic fields (existing directives and regulations, case of electric lines and of radio-frequencies), exposure to electromagnetic fields (occupational exposure in medical or industrial applications, specific devices such as telephones, regulation)

  5. Recent advances in biological effect and molecular mechanism of arabidopsis thaliana irradiated by ion beams

    International Nuclear Information System (INIS)

    Newly research progresses were summarized in effect of ion beams on seed surface, biological effect, growth, development, gravitropism and so on. Furthermore, mutation molecular mechanism of Arabidopsis thaliana was discussed, for example, alteration of DNA bases, DNA damage, chromosomal recombination, characteristics of mutant transmissibility, etc. Meanwhile, the achievements of transfer- ring extraneous gene to Arabidopsis thaliana by ion beams were reviewed in the paper. At last, the future prospective are also discussed here in mutation molecular mechanism and the potential application of biological effect of heavy ion beams. (authors)

  6. Effect of biologic therapy on radiological progression in rheumatoid arthritis: what does it add to methotrexate?

    Directory of Open Access Journals (Sweden)

    Jones G

    2012-07-01

    Full Text Available Graeme Jones, Erica Darian-Smith, Michael Kwok, Tania WinzenbergMenzies Research Institute, University of Tasmania, Tasmania, AustraliaAbstract: There have been substantial advances in the treatment of rheumatoid arthritis in recent years. Traditional disease-modifying antirheumatic drugs (DMARDs have been shown to have small effects on the progression of radiographic damage. This quantitative overview summarizes the evidence for biologic DMARDS and radiographic damage either alone or in combination with methotrexate. Two outcomes were used (standardized mean difference and odds of progression. A total of 21 trials were identified of which 18 had useable data. For biologic monotherapy, tocilizumab, adalimumab, and etanercept were significantly better than methotrexate, with tocilizumab ranking first in both outcomes while golimumab was ineffective in both outcomes. For a biologic in combination with methotrexate compared with methotrexate alone, most therapies studied (etanercept, adalimumab, infliximab, certolizumab, tocilizumab, and rituximab were effective at slowing X-ray progression using either outcome, with infliximab ranking first in both outcomes. The exceptions to this were golimumab (no effect on standardized mean difference and abatacept (no effect on odds of progression. This effect was additional to methotrexate; thus, the overall benefit is moderate to large in magnitude, which is clearly of major clinical significance for sufferers of rheumatoid arthritis and supports the use of biologic DMARDs in those with a poor disease prognosis.Keywords: rheumatoid, trials, meta-analysis, radiographs, biologic, disease-modifying antirheumatic drugs, DMARDs

  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. 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

  9. Studies on the biological effects of deuteriated organic compounds

    International Nuclear Information System (INIS)

    In order to visualise the morphological changes of Epidermophyton floccosum associated with exposure to perdeuteriated n-hendecanoic acid, the architecture of the dermatophyte was investigated by means of interference contrast and scanning electron microscopy. The mortphology of mycelia grown on substrate containing perdeuteriated n-hendecnoic acid, or the unlabelled analogue, was compared. The perdeuteriated n-hendecanoic acid produced a characteristic undulant effect of the hyphae. The characteristic wave-lake appearance of the mycelia looked similar to the curling effect occurring after treatment of dermatophytes with griseofulvin, but was not so pronounced. Perdeuteriated n-hendecanoic acid, unlike the unlabelled analogue, also seems to cause a reduction of the number of chlamydospores perforations of the macroconidia. The changes in the morphological structure of Epidermophyton floccosum exposed to perdeuteriated n-hendecanoic acid have been investigated. Morphological examination of mycelia exposed to this substance by interference contrast microscopy demonstrated a picture of defect hyphae and macroconidia. By the aid of scanning electron microscopy an attempt was made to obtain a better visualization of these changes at ultrastructural level

  10. Low power laser therapy — an introduction and a review of some biological effects

    OpenAIRE

    Thiel, Haymo

    1986-01-01

    This report gives a brief introduction to the characteristics of therapeutic low power laser devices. Absorption, tissue penetration and physiological mechanisms of laser irradiation are discussed. The biological effects of low power laser light are reviewed in the areas of collagen metabolism, woundhealing, inflammation and pain control. Contraindications, precautions and side effects of low power laser irradiation are discussed.

  11. Low doses of ionizing radiation: Biological effects and regulatory control. Contributed papers

    International Nuclear Information System (INIS)

    The International Atomic Energy Agency and the World Health Organization, in cooperation with the United Nations Scientific Committee on the Effects of Atomic Radiation, organized an international conference on Low Doses of Ionizing Radiation: Biological Effects and Regulatory Control, held in seville, Spain, from 17 to 21 November 1997. This technical document contains concise papers submitted to the conference

  12. The College Student and Marijuana: Research Findings Concerning Adverse Biological and Psychological Effects.

    Science.gov (United States)

    Nicholi, Armand M., Jr.

    1983-01-01

    This paper focuses on current knowledge about adverse biological and psychological affects of marijuana use, with special reference to risks for college students. Short-term effects on intellectual functioning and perceptual-motor coordination and long-term effects on reproduction and motivation are highlighted. (PP)

  13. Mindmapping: Its effects on student achievement in high school biology

    Science.gov (United States)

    Cunningham, Glennis Edge

    The primary goal of schools is to promote the highest degree of learning possible. Yet teachers spend the majority of their time engaged in lecturing while students spend the majority of their time passively present (Cawelti, 1997, Grinder, 1991; Jackson & Davis, 2000; Jenkins, 1996). Helping students develop proficiency in learning, which translates into using that expertise to construct knowledge in subject domains, is a crucial goal of education. Students need exposure to teaching and learning practices that prepare them for both the classroom and their places in the future workforce (Ettinger, 1998; Longley, Goodchild, Maguire, & Rhind, 2001; NRC, 1996; Texley & Wild, 1996). The purpose of this study was to determine if achievement in high school science courses could be enhanced utilizing mindmapping. The subjects were primarily 9th and 10th graders (n = 147) at a suburban South Texas high school. A pretest-posttest control group design was selected to determine the effects of mindmapping on student achievement as measured by a teacher-developed, panel-validated instrument. Follow-up interviews were conducted with the teacher and a purposive sample of students (n = 7) to determine their perceptions of mindmapping and its effects on teaching and learning. Mindmapping is a strategy for visually displaying large amounts of conceptual, hierarchical information in a concise, organized, and accessible format. Mindmaps arrange information similar to that found on the traditional topic outline into colorful spatial displays that offer the user a view of the "forest" as well as the "trees" (Hyerle, 1996; Wandersee, 1990b). An independent samples t-test and a one-way analysis of covariance (ANCOVA) determined no significant difference in achievement between the groups. The experimental group improved in achievement at least as much as the control group. Several factors may have played a role in the lack of statistically significant results. These factors include the

  14. Vital tooth bleaching: biologic adverse effects-a review.

    Science.gov (United States)

    Minoux, Maryline; Serfaty, Rene

    2008-09-01

    Depending on etiology, the esthetic treatment of dyschromia may involve vital tooth- bleaching techniques. Hydrogen peroxide is the active molecule used for such procedures; however, its action mechanism is not clearly understood. Moreover, a variety of contradictory studies make difficult the evaluation of the safety of bleaching techniques. The purpose of this article is therefore to review the available literature (1) to describe the physicochemical properties of hydrogen peroxide and (2) to assess the safety of its use as a vital tooth-bleaching agent. Indeed, based on hydrogen peroxide's capacity to generate free radicals that diffuse throughout the dental hard tissues, concerns have been addressed regarding the adverse effects that bleaching products can induce on the enamel and dentin structures, pulp, and bonding to a composite resin system. Moreover, during self-application of home bleaching products, hydrogen peroxide is released into the oral cavity and ingested. Some questions have therefore arisen concerning its toxicity and its possible carcinogenicity. PMID:19107251

  15. Biological effects of irradiation on skin and recommended dose limits

    International Nuclear Information System (INIS)

    The range of radiation responses of the skin are reviewed in terms of the time course over which damage is expressed and the likely underlying pathogenesis. Responses of specific concern in radiological protection have been identified; these include acute necrosis/ulceration after exposure to radioactive 'hot' particles, and moist desquamation, late dermal atrophy or telangiectasia after more generalised exposures from intermediate and high energy β emitters. Acute epidermal necrosis is the only endpoint of concern after exposure to low energy β emitters. Dose-effect relationships have been established for each of these responses and on this basis recommendations for dose limitation for the skin can be made along with proposals for the depths at which dose should be assessed in routine monitoring procedures. (author)

  16. Studies on the biological effects of deuteriated organic compounds

    International Nuclear Information System (INIS)

    The antifungal activity of some perdeuterated fatty acids with a normal chain of 11 to 18 carbon atoms was investigated on common dermatophytes Epidermophyton floccosum, Microsporum canis, Trichophyton mentagrophytes and T. rubrum under in vitro conditions. A perdeuterated compound is one in which most of the hydrogen atoms in the molecule are replaced by deuterium. These studies were performed by the dilution technique with respiratory measurements. Perdeuteration of of some fatty acids increases their inhibitory effect on the dermatophyte growth. Perdeuterated n-hendecanoic acid proved to be the most active of the substances tested. Possible mechanisms behind the enhanced antifungal activity due to the perdeuteration of fatty acids are discussed. The present study investigates the antifungal properties of some perdeuterated fatty acids on dermatophytes in vitro

  17. Iodine Oxide Thermite Reactions: Physical and Biological Effects

    Science.gov (United States)

    Russell, Rod; Pantoya, Michelle; Bless, Stephan; Clark, William

    2009-06-01

    We investigated the potential for some thermite-like material reactions to kill bacteria spores. Iodine oxides and silver oxides react vigorously with metals like aluminum, tantalum, and neodymium. These reactions theoretically produce temperatures as high as 8000K, leading to vaporization of the reactants, producing very hot iodine and/or silver gases. We performed a series of computations and experiments to characterize these reactions under both quasi-static and ballistic impact conditions. Criteria for impact reaction were established. Measurements of temperature and pressure changes and chemical evolution will be reported. Basic combustion characterizations of these reactions, such as thermal equilibrium analysis and reaction propagation rates as well as ignition sensitivity, will be discussed. Additionally, testing protocols were developed to characterize the biocidal effects of these reactive materials on B. subtilis spores. The evidence from these tests indicates that these reactions produce heat, pressure, and highly biocidal gases.

  18. Effect of HRT on CSTR converting starch into biological hydrogen

    International Nuclear Information System (INIS)

    There are few reports on continuous bio hydrogen production from biopolymers like starch, because most previous studies on continuous operation were performed using simple hydrolysates such as glucose and sucrose. This study was, therefore, carried out to investigate the effect of hydraulic retention time (HRT) on continuous bio hydrogen production in a continuous stirred-tank reactor (CSTR) using corn starch as a substrate for 158 days. Volatile fatty acids (VFA) profile supported the fact that butyrate to acetate (B/A) ratio was the most important parameter to justify hydrogen yield at various HRTs. Maximum hydrogen yield of 0.92 mol H/sub 2/mol, glucose/sub added/ was observed at 12 hr HRT with the highest B/A ratio of 4.3. Also, estimation modeling to quantify homoacetogenism was conducted and H/sub 2/-consuming acetate production, at various HRTs was estimated. (author)

  19. Effects of low-level radiation on biologic systems: a literature review

    International Nuclear Information System (INIS)

    This review presents an organized survey of scientific literature dealing with the biologic effects of low-level radiation. It includes brief discussions of topics of particular interest, a listing of useful review articles, an extensive bibliography, and listings of sources that can be used to update this document in the future. The topics discussed include experimental studies, the linear hypothesis, medical effects, occupational effects, effects of exposure to naturally occurring radiation, consumer products, and laws and regulations

  20. Bioaccumulation and biological effects of cigarette litter in marine worms.

    Science.gov (United States)

    Wright, Stephanie L; Rowe, Darren; Reid, Malcolm J; Thomas, Kevin V; Galloway, Tamara S

    2015-01-01

    Marine debris is a global environmental issue. Smoked cigarette filters are the predominant coastal litter item; 4.5 trillion are littered annually, presenting a source of bioplastic microfibres (cellulose acetate) and harmful toxicants to marine environments. Despite the human health risks associated with smoking, little is known of the hazards cigarette filters present to marine life. Here we studied the impacts of smoked cigarette filter toxicants and microfibres on the polychaete worm Hediste diversicolor (ragworm), a widespread inhabitant of coastal sediments. Ragworms exposed to smoked cigarette filter toxicants in seawater at concentrations 60 fold lower than those reported for urban run-off exhibited significantly longer burrowing times, >30% weight loss, and >2-fold increase in DNA damage compared to ragworms maintained in control conditions. In contrast, ragworms exposed to smoked cigarette filter microfibres in marine sediment showed no significant effects. Bioconcentration factors for nicotine were 500 fold higher from seawater than from sediment. Our results illustrate the vulnerability of organisms in the water column to smoking debris and associated toxicants, and highlight the risks posed by smoked cigarette filter debris to aquatic life. PMID:26369692

  1. Cardiometabolic risk in psoriasis: differential effects of biologic agents

    Directory of Open Access Journals (Sweden)

    Mariana J Kaplan

    2008-08-01

    Full Text Available Mariana J KaplanDepartment of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, USAAbstract: Psoriasis is associated to an increased risk of cardiovascular (CV complications. Overall, the pathogenic mechanisms involved in premature CV complications in psoriasis appear to be complex and multifactorial, with traditional and nontraditional risk factors possibly contributing to the increased risk. Based on what is known about the pathogenesis of psoriasis and extrapolating the current knowledge on CV complications in other inflammatory diseases, studies are needed to investigate if appropriate control of the inflammatory, immunologic and metabolic disturbances present in psoriasis can prevent the development of this potentially lethal complication. It is clear that there is a great need for heightened awareness of the increased risk for vascular damage in patients with psoriasis. It is also crucial to closely monitor patients with psoriasis for CV risk factors including obesity, hypertension, diabetes, and hyperlipidemia. Whether treatment regimens that effectively manage systemic inflammation will lead to prevention of CV complications in psoriasis needs to be investigated. Clearly, studies should focus on establishing the exact mechanisms that determine CV risk in psoriasis so that appropriate preventive strategies and treatment guidelines can be established.Keywords: psoriasis, atherosclerosis, inflammation, vascular

  2. Biological effects of laser-induced stress waves

    International Nuclear Information System (INIS)

    Laser-induced stress waves can be generated by one of the following mechanisms: Optical breakdown, ablation or rapid heating of an absorbing medium. These three modes of laser interaction with matter allow the investigation of cellular and tissue responses to stress waves with different characteristics and under different conditions. The most widely studied phenomena are those of the collateral damage seen in photodisruption in the eye and in 193 run ablation of cornea and skin. On the other hand, the therapeutic application of laser-induced stress waves has been limited to the disruption of noncellular material such as renal stones, atheromatous plaque and vitreous strands. The effects of stress waves to cells and tissues can be quite disparate. Stress waves can fracture tissue, damage cells, and increase the permeability of the plasma membrane. The viability of cell cultures exposed to stress waves increases with the peak stress and the number of pulses applied. The rise time of the stress wave also influences the degree of cell injury. In fact, cell viability, as measured by thymidine incorporation, correlates better with the stress gradient than peak stress. Recent studies have also established that stress waves induce a transient increase of the permeability of the plasma membrane in vitro. In addition, if the stress gradient is below the damage threshhold, the cells remain viable. Thus, stress waves can be useful as a means of drug delivery, increasing the intracellular drug concentration and allowing the use of drugs which are impermeable to the cell membrane. The present studies show that it is important to create controllable stress waves. The wavelength tunability and the micropulse structure of the free electron laser is ideal for generating stress waves with independently adjustable parameters, such as rise time, duration and peak stress

  3. Effects of Magnetic Field on Biological Cells and Applications

    Science.gov (United States)

    Chen, Ching-Jen

    2001-03-01

    While there has been extensive research performed in the physics of magnetic fields and the physics and chemistry in life sciences, independent of each other, there has been a paucity of scientific research and development investigating the possible applications of magnetic fields in life sciences. The focus of this presentation is to present the stimulation mechanism by which magnetic fields affect (a) yeast cells (b) plant cells and (c) mammalian normal and cancer cells. Recently we have found that the Saccharomyces Cerevsa yeast growth increases by about 30to a 1 tesla field and the production of CO2 increases by about 30of yeast metabolism may be due to an increase in intercellular interaction and protein channel alignment, the introduction of an alteration in the DNA from the magnetic field exposure or a combination of these mechanisms. We also have found that the application of high magnetic fields (1 tesla and above) can have marked effects on the germination and growth of plants, especially corn, beans and peas. This finding has opened up the possibility of technology developments in botanical growth systems to accelerate seed germination and crop harvesting. Most recently we have investigated the application of high magnetic fields on leukemia, CaCoII and HEP G2 cancer cell lines. We found that when leukemia are exposed to a 12 tesla field for 2 hours has an increase in cell death by about 30that were not exposed to the magnetic field. Viability of CaCoII cells sandwiched between permanent magnets of maximum strength of 1.2 tesla was measured. A decrease in viable cells by 33unexposed cells. HSP 70 was measured for HEPG2 cells that were exposed to permanent magnetic field of 1.2 tesla for 40 minutes and for unexposed cells. It was found that the exposed cells produce 19 times more HSP70 compared to unexposed cells. Our results together with other investigators report suggest a strong evidence of a reduction in the cell growth rate for cancer cells when

  4. Biological effects of neutrons, mechanisms and applications; Effets biologiques des neutrons: mecanismes et applications

    Energy Technology Data Exchange (ETDEWEB)

    Voisin, Ph. [CEA/Fontenay-aux-Roses, Inst. de Protection et de Surete Nucleaire (IPSN), 92 (France)

    1999-12-01

    The interest to study the ionizing radiations effects on the biological structures concern not only the fundamental comprehension of the mechanisms leading to the radiation damage but also much more pragmatic problems such as the accidental overexposure or radiotherapy treatment. Among these fundamental or applied studies, the neutrons effects take an important part, because of their particular mode of indirect ionization effect and their applications, as well civil as military ones. The purpose of this review is to point out some specific biological effects of neutrons and to describe biological methods to measure them. It clearly appears that neutrons biological effects are more deleterious than those caused by the radiations of lower TEL(X- and {gamma}-rays) taken as reference, for all the measurement levels used, genes mutations, chromosome aberrations, cellular survival or carcinogenesis. This difference is probably related to the density of the energy deposit in the vital cell targets, and to the absence of significant variations related to oxygenation, dose rate or dose fractionation. Such toxic effects, when considered in the course of a criticality accident, can paradoxically become an advantage in the follow-up of therapeutic treatment. (author)

  5. Nonlinear effects of the finite amplitude ultrasound wave in biological tissues

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Nonlinear effects will occur during the transmission of the finite amplitude wave in biological tissues.The theoretical prediction and experimental demonstration of the nonlinear effects on the propagation of the finite amplitude wave at the range of biomedical ultrasound frequency and intensity are studied.Results show that the efficiency factor and effective propagation distance will decrease while the attenuation coefficient increases due to the existence of nonlinear effects.The experimental results coincided quite well with the theory.This shows that the effective propagation distance and efficiency factor can be used to describe quantitatively the influence of nonlinear effects on the propagation of the finite amplitude sound wave in biological tissues.

  6. Effective identification of conserved pathways in biological networks using hidden Markov models.

    Directory of Open Access Journals (Sweden)

    Xiaoning Qian

    Full Text Available BACKGROUND: The advent of various high-throughput experimental techniques for measuring molecular interactions has enabled the systematic study of biological interactions on a global scale. Since biological processes are carried out by elaborate collaborations of numerous molecules that give rise to a complex network of molecular interactions, comparative analysis of these biological networks can bring important insights into the functional organization and regulatory mechanisms of biological systems. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we present an effective framework for identifying common interaction patterns in the biological networks of different organisms based on hidden Markov models (HMMs. Given two or more networks, our method efficiently finds the top matching paths in the respective networks, where the matching paths may contain a flexible number of consecutive insertions and deletions. CONCLUSIONS/SIGNIFICANCE: Based on several protein-protein interaction (PPI networks obtained from the Database of Interacting Proteins (DIP and other public databases, we demonstrate that our method is able to detect biologically significant pathways that are conserved across different organisms. Our algorithm has a polynomial complexity that grows linearly with the size of the aligned paths. This enables the search for very long paths with more than 10 nodes within a few minutes on a desktop computer. The software program that implements this algorithm is available upon request from the authors.

  7. Effects of 3 biologic dressings on healing of cutaneous wounds on the limbs of horses

    OpenAIRE

    Gomez, Jorge H.; Schumacher, Jim; Lauten, Susan D.; Sartin, Eva A.; Hathcock, Terri L.; Swaim, Steven F.

    2004-01-01

    Three biologic dressings [split-thickness allogeneic skin (STS)], allogeneic peritoneum (P), and xenogenic porcine small intestinal submucosa (PSIS)] were studied to determine their effects on bacterial proliferation, inflammatory reaction, vascularization, and overall healing and to compare the effects of these dressings with the effects of a nonbiologic dressing, a nonadherent synthetic pad (NASP). A medial wound (3 cm in diameter) and 2 lateral wounds (2 cm in diameter) were created at the...

  8. Methods for studying and criteria for evaluating the biological effects of electric fields of industrial frequency

    Energy Technology Data Exchange (ETDEWEB)

    Savin, B.M.; Shandala, M.G.; Nikonova, K.V.; Morozov, Yu.A.

    1978-10-01

    Data are reviewed from a number of USSR research studies on the biological effects of electric power transmission lines of 1150 Kv and above. Effects on man, plants, animals, and terrestrial ecosystems are reported. Existing health standards in the USSR for the exposure of personnel working in electric fields are included. It is concluded that high-voltage electric fields have a harmful effect on man and his environment.

  9. 'K' contribution to the biological effect of ionizing radiations

    International Nuclear Information System (INIS)

    The aim of this work is to determine the importance of 'K' ionizations on DNA as critical physical events initiating the biological effects of ionizing radiation, in particular in human cells. Ultra-soft X-rays are used as a probe of core ionization events. A decisive test consists in comparing the biological effects at 250 eV and 350 eV (before and after the carbon K - threshold). The results show a sharp increase of the biological efficiency for both cellular inactivation and chromosomal exchange aberration above the carbon K-threshold, correlated with the one of core events occurring in DNA atoms. The heavy ion irradiation displays again the paradoxical behaviour of cellular inactivation cross sections as a function of LET. Finally, the 'K' event contribution to cellular inactivation of usual low LET radiation is estimated to be about 75%. (author)

  10. Comparative SPR study on the effect of nanomaterials on the biological activity of adsorbed proteins

    International Nuclear Information System (INIS)

    Bioactivity of proteins is evaluated to test the adverse effects of nanoparticles interjected into biological systems. Surface plasmon resonance (SPR) spectroscopy detects binding affinity that is normally related to biological activity. Utilizing SPR spectroscopy, a concise testing matrix is established by investigating the adsorption level of bovine serum albumin (BSA) and anti-BSA on the surface covered with 11-mercaptoundecanoic acid (MUA); magnetic nanoparticles (MNPs) and single-walled carbon nanotubes (SWCNTs), respectively. The immunoactivity of BSA on MNPs and SWCNT decreased by 18 % and 5 %, respectively, compared to that on the gold film modified with MUA. This indicates that MNPs cause a considerable loss of biological activity of adsorbed protein. This effect can be utilized for practical applications on detailed biophysical research and nanotoxicity studies. (author)

  11. Insight into Biological Effects of Zinc Oxide Nanoflowers on Bacteria: Why Morphology Matters.

    Science.gov (United States)

    Cai, Qian; Gao, Yangyang; Gao, Tianyi; Lan, Shi; Simalou, Oudjaniyobi; Zhou, Xinyue; Zhang, Yanling; Harnoode, Chokto; Gao, Ge; Dong, Alideertu

    2016-04-27

    Zinc oxides have gained exciting achievements in antimicrobial fields because of their advantageous properties, whereas their biological effects on bacteria are currently underexplored. In this study, biological effects of flower-shaped nano zinc oxides on bacteria were systematically investigated. Zinc oxide nanoflowers with controllable morphologies (viz., rod flowers, fusiform flowers, and petal flowers) were synthesized by modulating merely base type and concentration using the hydrothermal process. Their antibacterial power is in an order of petal flowers > fusiform flowers > rod flowers because of their differences in microscopic parameters such as specific surface area, pore size, and Zn-polar plane, etc. More importantly, the role of morphology in influencing biological effect on bacteria was examined, focusing on the morphology-induced effect on integrality of cell wall, permeability of cell membrane, DNA cleavage, etc. As for cytotoxicity, all petal flowers, fusiform flowers, and rod flowers show trivial cytotoxicity to the Hela cells. This work provides a guide for enhancing biological effect of the biocides on pathogenic bacteria by the morphological modulation. PMID:27042940

  12. Biologically effective doses of postoperative radiotherapy in the prevention of keloids. Dose-effect relationship

    International Nuclear Information System (INIS)

    Purpose: To review the recurrence rates of keloids after surgical excision followed by radiotherapy, and to answer the question whether after normalization of the dose, a dose-effect relationship could be derived. Material and Methods: A literature search was performed to identify studies dealing with the efficacy of various irradiation regimes for the prevention of keloids after surgery. Biologically effective doses (BEDs) of the various irradiation regimens were calculated using the linear-quadratic concept. A distinction between recurrence rates of keloids in the face and neck region and those in other parts of the body was made. Results: 31 reports were identified with PubMed with the search terms keloids, surgery, radiation therapy, radiotherapy. 13 reports were excluded, because no link could be found between recurrence rate and dose, or if less than ten patients per dose group. The recurrence rate for surgery only was 50-80%. For BED values >10 Gy the recurrence rate decreased as a function of BED. For BED values >30 Gy the recurrence rate was <10%. For a given dose, the recurrence rates of keloids in the sites with high stretch tension were not significantly higher than in sites without stretch tension. Conclusion: The results of this study indicate that for effectively treating keloids postoperatively, a relatively high dose must be applied in a short overall treatment time. The optimal treatment probably is an irradiation scheme resulting in a BED value of at least 30 Gy. A BED value of 30 Gy can be obtained with, for instance, a single acute dose of 13 Gy, two fractions of 8 Gy two fractions of 8 Gy or three fractions of 6 Gy, or a single dose of 27 Gy at low dose rate. The radiation treatment should be administered within 2 days after surgery. (orig.)

  13. A Novel Biological Dosimetry Method for Monitoring Occupational Radiation Exposure in Diagnostic and Therapeutic Wards: From Radiation Dosimetry to Biological Effects

    OpenAIRE

    Heydarheydari, S.; Haghparast, A.; Eivazi, M.T.

    2016-01-01

    Background and Objective Professional radiation workers are occupationally exposed to long-term low levels of ionizing radiation. Occupational health hazards from radiation exposure, in a large occupational segment of the population, are of special concern. Biological dosimetry can be performed in addition to physical dosimetry with the aim of individual dose assessment and biological effects. Methods In this biodosimetry study, some hematological parameters have been examined in 40 exposed a...

  14. Sensorless adaptive optics and the effect of field of view in biological second harmonic generation microscopy

    Science.gov (United States)

    Vandendriessche, Stefaan; Vanbel, Maarten K.; Verbiest, Thierry

    2014-05-01

    In light of the population aging in many developed countries, there is a great economical interest in improving the speed and cost-efficiency of healthcare. Clinical diagnosis tools are key to these improvements, with biophotonics providing a means to achieve them. Standard optical microscopy of in vitro biological samples has been an important diagnosis tool since the invention of the microscope, with well known resolution limits. Nonlinear optical imaging improves on the resolution limits of linear microscopy, while providing higher contrast images and a greater penetration depth due to the red-shifted incident light compared to standard optical microscopy. It also provides information on molecular orientation and chirality. Adaptive optics can improve the quality of nonlinear optical images. We analyzed the effect of sensorless adaptive optics on the quality of the nonlinear optical images of biological samples. We demonstrate that care needs to be taken when using a large field of view. Our findings provide information on how to improve the quality of nonlinear optical imaging, and can be generalized to other in vitro biological samples. The image quality improvements achieved by adaptive optics should help speed up clinical diagnostics in vitro, while increasing their accuracy and helping decrease detection limits. The same principles apply to in vivo biological samples, and in the future it may be possible to extend these findings to other nonlinear optical effects used in biological imaging.

  15. The study of biological effects of electromagnetic mobile phone radiation on experimental animals by combining numerical modeling and experimental research

    OpenAIRE

    Dejan Krstić; Darko Zigar; Dušan Sokolović; Boris Đinđić; Branka Đorđević; Momir Dunjić; Goran Ristić

    2012-01-01

    In order to study biological effects of electromagneticradiation, it is essential to know the real values of field componentsthat penetrated the tissue. The study of biological effects is usuallyperformed on experimental animals. The biological effects observedon experimental animals should be linked with penetrating field inthe tissue. The penetrating electromagnetic field is almost impossibleto measure; therefore, modeling process must be carried out and thefield components in models of exp...

  16. Effectiveness of the Biology PTechLS Module in a Felda Science Centre

    Science.gov (United States)

    Alias, Norlidah; DeWitt, Dorothy; Rahman, Mohd Nazri Abdul; Gelamdin, Rashidah Begum; Rauf, Rose Amnah Abd; Siraj, Saedah

    2014-01-01

    The PTechLS module combines learning styles with the use of technology to increase students' learning experience, especially in learning abstract concepts. The PTechLS module prototype was developed by Norlidah Alias (2010). The aim of this study is to evaluate the implementation effectiveness of the Biology PTechLS module in a Felda Learning…

  17. Fertility among HIV-infected Indian women Indian women : the biological effect and its implications

    NARCIS (Netherlands)

    Darak, Shrinivas; Janssen, Fanny; Hutter, Inge

    2011-01-01

    In India, nearly one million women of childbearing age are infected with HIV. This study sought to examine the biological effect of HIV on the fertility of HIV-infected Indian women. This is relevant for the provision of pregnancy-related counselling and care to the infected women, and for estimatin

  18. Effects of Conceptual Change Text Based Instruction on Ecology, Attitudes toward Biology and Environment

    Science.gov (United States)

    Çetin, Gülcan; Ertepinar, Hamide; Geban, Ömer

    2015-01-01

    The purpose of this study is to investigate the effects of the conceptual change text based instruction on ninth grade students' understanding of ecological concepts, and attitudes toward biology and environment. Participants were 82 ninth grade students in a public high school in the Northwestern Turkey. A treatment was employed over a…

  19. Effects of Scoring by Section and Independent Scorers' Patterns on Scorer Reliability in Biology Essay Tests

    Science.gov (United States)

    Ebuoh, Casmir N.; Ezeudu, S. A.

    2015-01-01

    The study investigated the effects of scoring by section, use of independent scorers and conventional patterns on scorer reliability in Biology essay tests. It was revealed from literature review that conventional pattern of scoring all items at a time in essay tests had been criticized for not being reliable. The study was true experimental study…

  20. Adaptive evolution of a generalist parasitoid: implications for the effectiveness of biological control agents

    OpenAIRE

    Zepeda-Paulo, Francisca A; Ortiz-Martínez, Sebastián A; Figueroa, Christian C.; Lavandero, Blas

    2013-01-01

    The use of alternative hosts imposes divergent selection pressures on parasitoid populations. In response to selective pressures, these populations may follow different evolutionary trajectories. Divergent natural selection could promote local host adaptation in populations, translating into direct benefits for biological control, thereby increasing their effectiveness on the target host. Alternatively, adaptive phenotypic plasticity could be favored over local adaptation in temporal and spat...

  1. Effects of biological pit additives on microbial ecology of stored pig manure

    Science.gov (United States)

    The effects of biological pit additives on microbial ecology in stored pig manure were investigated using a dynamic manure storage system, which allowed for continual addition of swine feces and urine. After 13 weeks of manure collection and storage, four treatments were added to tanks (900 L capaci...

  2. EFFECTS OF MYCOTOXINS, KOJIC ACID AND OXALIC ACID, ON BIOLOGICAL FITNESS OF LYGUS HESPERUS (HETEROPTERA: MIRIDAE)

    Science.gov (United States)

    Mycotoxins kojic acid and oxalic acid are produced by many species of fungi, including Aspergillus niger, a common contaminant in insectaries. It has been previously shown by this laboratory to have detrimental effects on the biological fitness of Lygus hesperus Knight (Heteroptera: Miridae). We e...

  3. Static magnetic fields: A summary of biological interactions, potential health effects, and exposure guidelines

    Energy Technology Data Exchange (ETDEWEB)

    Tenforde, T.S.

    1992-05-01

    Interest in the mechanisms of interaction and the biological effects of static magnetic fields has increased significantly during the past two decades as a result of the growing number of applications of these fields in research, industry and medicine. A major stimulus for research on the bioeffects of static magnetic fields has been the effort to develop new technologies for energy production and storage that utilize intense magnetic fields (e.g., thermonuclear fusion reactors and superconducting magnet energy storage devices). Interest in the possible biological interactions and health effects of static magnetic fields has also been increased as a result of recent developments in magnetic levitation as a mode of public transportation. In addition, the rapid emergence of magnetic resonance imaging as a new clinical diagnostic procedure has, in recent years, provided a strong rationale for defining the possible biological effects of magnetic fields with high flux densities. In this review, the principal interaction mechanisms of static magnetic fields will be described, and a summary will be given of the present state of knowledge of the biological, environmental, and human health effects of these fields.

  4. Wood smoke particle sequesters cell iron to impact a biological effect.

    Science.gov (United States)

    The biological effect of an inorganic particle (i.e., silica) can be associated with a disruption in cell iron homeostasis. Organic compounds included in particles originating from combustion processes can also complex sources of host cell iron to disrupt metal homeostasis. We te...

  5. Effect of temperature on the biology of Paracoccus marginatus Williams and Granara de Willink (Homoptera: Pseudococcidae).

    Science.gov (United States)

    Abstract: Effect of temperature on the biology of Paracoccus marginatus was investigated. P. marginatus was able to develop and complete its life cycle at 18°, 20°, 25° and 30°C. At 15°, 34° and 35°C eggs hatched, but further development was arrested. Approximately 80 -90% of the eggs survived betw...

  6. Functionalization and microfluidic integration of silicon nanowire biologically gated field effect transistors

    DEFF Research Database (Denmark)

    Pfreundt, Andrea

    This thesis deals with the development of a novel biosensor for the detection of biomolecules based on a silicon nanowire biologically gated field-effect transistor and its integration into a point-of-care device. The sensor and electrical on-chip integration was developed in a different project...

  7. Compost and Biological Amendment Effects on Soilborne Disease and Soil Microbial Communities

    Science.gov (United States)

    Effects of compost and biological amendments on soilborne diseases and microorganisms were assessed in field trials in northern Maine under both conventional and organic potato production practices. Three different biocontrol amendments, hypovirulent Rhizoctonia solani Rhs 1A1 (HvRs), Bacillus subti...

  8. The biological effect of arc discharge plasma combined with gradual magnetic field on tomato seeds

    International Nuclear Information System (INIS)

    Using arc discharge plasma combined with gradual magnetic field to treat seeds is a new plasma biological technology. The biological effect and drought resistance of tomato seeds treated with different plasma parameters were compared. The increasing of proline content indicates that the drought resistance of tomato seedlings could be increased due to reduction of penetration potential of plant cell. Increased SOD, POD activity, root activity and ATP content show that water stress could be alleviated by eliminating the free radicle and increasing metabolism. (authors)

  9. The Relative Biologic Effectiveness versus Linear Energy Transfer Curve as a Cell Trait

    OpenAIRE

    Quoc T. Luu; Paul DuChateau

    2013-01-01

    The magnitude of biological response varies with different radiation types. Using Linear Energy Transfer (LET) to differentiate types of incident radiation beam, the Relative Biologic Effectiveness (RBE) as a function of LET (RBE-LET) was found to have a characteristic shape with a peak around LET values 100 - 200 eV/nm. This general feature is believed to be a property of the incident beam. Our systems engineering model, however, suggests that the shape of the RBE-LET curve is a cell tr...

  10. STUDY ON THE RELATIONSHIP OF ARSENIC TRIOXIDE-INDUCED BIOLOGICAL EFFECTS AND DEGRADATIONOF PML PROTEINS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective To understand whether arsenic trioxide (As2O3)-induced biological effects are associated with degradation of PML proteins. Methods Acute promyelocytic leukemia (APL) cell line NB4, acute T-lymphocytic leukemia cell line Jurkat, acute myeloid leukemia cell line U937, and chronic myelocytic leukemia blast crisis cell line K562 were used as in vitro models. In different cell lines, the As2O3-induced bio- logical effects were determined by cell growth, cell viability, cell morphology, and flow cytometry assay on sub- G1 cell content. The alteration of PML proteins was analyzed by immunofluorescence. Results In terms of growth inhibition and apoptosis induction, 1.0μmol/L As2O3 had different effects on different cell lines. However, degradation of PML proteins occurred in all the cell lines with As2O3 treatment. Conclusion As2O3-induced biological effects may be independent of PML protein degradation.

  11. Some Results of the Research Work on the Biological Effect of Neutrons and Protons

    International Nuclear Information System (INIS)

    The author correlates and analyses the experimental data obtained over the past two or three years regarding the biological effects of neutrons and high-energy protons, and shows that it is a matter of prime concern for present-day radiobiology to investigate the relative biological effectiveness of the various types of radiation under various irradiation conditions and the reasons for the qualitative differences in their effect on the animal organism. Attention is drawn to the need for more research into the combined effect of various types of radiation and other agents. Specific examples are cited to demonstrate the main progress achieved in studying the prophylaxis of radiation injury induced by neutrons or high-energy protons and to show the contribution such research can make towards understanding the specific way in which various types of radiation act. (author)

  12. Information on biological health effects of ionizing radiation and radionuclides: the rule of a web site

    International Nuclear Information System (INIS)

    The purpose of this project is to provide a source of information on biological and health effects of radionuclides and ionizing radiation in an easy to use format. Reported work is made up of two distinct parts: data sheets for selected radionuclides and a web file. Data sheets: Specific radiation data sheets provide an overview of the properties, the environmental behaviour, the different pathways of human exposure and the biological and health consequences of selected radionuclides. Radionuclides that have been selected are those commonly dealt with in nuclear industry (and in other areas such as medicine) and released to the environment or naturally occurring (plutonium, tritium, carbon 14). Data sheets corresponding to the different radionuclides are based on the main sources of scientific information in dosimetry, epidemiology, radiobiology and radiation protection. These data sheets are intended for radiation protection specialists and physicians. They include: main physical and chemical characteristics, main radiation protection data: dose coefficients (public, workers), dose limits sources, total released estimate (nuclear industry, atmospheric tests, main pathway of human exposure and biological behaviour, biological and health effects, medical supervision, treatment a list of the main references, appendix providing accurate information. Web file: http://www-dsv.cea.fr/doc/carmin_ext/fond.php This web file provides a source of information on biological and health effects of ionizing radiation and biological basic knowledge of radiation protection. Available for consultation via Internet, compiled information provides, in a same file, subjects as varied as biological mechanisms, ionizing radiations action, biological and health effects, risk assessment This file is mainly intended to assist in informing and training of non-specialist readership (students, teaching on radiation protection basic knowledge. This electronic document is divided in three

  13. Inquiry-based training improves teaching effectiveness of biology teaching assistants

    OpenAIRE

    Hughes, P William; Ellefson, Michelle R.

    2013-01-01

    Graduate teaching assistants (GTAs) are used extensively as undergraduate science lab instructors at universities, yet they often have having minimal instructional training and little is known about effective training methods. This blind randomized control trial study assessed the impact of two training regimens on GTA teaching effectiveness. GTAs teaching undergraduate biology labs (n = 52) completed five hours of training in either inquiry-based learning pedagogy or general instructional “b...

  14. A Simpler Energy Transfer Efficiency Model to Predict Relative Biological Effect for Protons and Heavier Ions

    OpenAIRE

    Jones, Bleddyn

    2015-01-01

    The aim of this work is to predict relative biological effectiveness (RBE) for protons and clinically relevant heavier ions, by using a simplified semi-empirical process based on rational expectations and published experimental results using different ion species. The model input parameters are: Z (effective nuclear charge) and radiosensitivity parameters αL and βL of the control low linear energy transfer (LET) radiation. Sequential saturation processes are assumed for: (a) the position of t...

  15. Status of study on biological and toxicological effects of nanoscale materials

    Institute of Scientific and Technical Information of China (English)

    WANG Bing; FENG Weiyue; ZHAO Yuliang; XING Gengmei; CHAI Zhifang; WANG Haifang; JIA Guang

    2005-01-01

    Because the physical and chemical properties of nanosized materials mostly differ from the existing microsized materials, their potential impacts on human health and the environment will be topics under the serious discussions in press and in a number of international scientific journals. We analyze and summarize the existing data of the experimental study on the biological activities and adverse effects of nanoscale materials/particles including single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron powders. Though some biological behaviors of nanoscale materials observed cannot be understood on the basis of the current knowledge, as the existing data are mostly preliminary, it is too early to make some exclusive conclusions on biological activities (or the toxicity) of any of nanoscale materials. The experimental techniques, the current topics, and the future research directions for this new research field are also discussed.

  16. Is ground cover vegetation an effective biological control enhancement strategy against olive pests?

    Directory of Open Access Journals (Sweden)

    Daniel Paredes

    Full Text Available Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history, the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard, or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae in 2,528 olive groves in Andalusia (Spain from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.

  17. Quenching effect of iron on uranium concentration measurements by fluorimetry in biological samples

    International Nuclear Information System (INIS)

    Iron is considered as a strong quencher that reduce the uranium fluorescence in biological sample. This effect was studied by two methods. In the first method iron concentration was fixed to study the effect on different uranium standard solutions. In the second method the concentration of uranium standard solutions were fixed while different amounts of iron were added if has been found that the quenching effect of iron is the same in low concentration of uranium, while in high concentration of uranium the quenching effect is greater. (author). 1 ref., 4 tabs

  18. Distinct biological effects of different nanoparticles commonly used in cosmetics and medicine coatings

    Directory of Open Access Journals (Sweden)

    Yu Julia X

    2011-05-01

    Full Text Available Abstract Background Metal oxides in nanoparticle form such as zinc oxide and titanium dioxide now appear on the ingredient lists of household products as common and diverse as cosmetics, sunscreens, toothpaste, and medicine. Previous studies of zinc oxide and titanium dioxide in non-nanoparticle format using animals have found few adverse effects. This has led the FDA to classify zinc oxide as GRAS (generally recognized as safe for use as a food additive. However, there is no regulation specific for the use of these chemicals in nanoparticle format. Recent studies, however, have begun to raise concerns over the pervasive use of these compounds in nanoparticle forms. Unfortunately, there is a lack of easily-adaptable screening methods that would allow for the detection of their biological effects. Results We adapted two image-based assays, a fluorescence resonance energy transfer-based caspase activation assay and a green fluorescent protein coupled-LC3 assay, to test for the biological effects of different nanoparticles in a high-throughput format. We show that zinc oxide nanoparticles are cytotoxic. We also show that titanium dioxide nanoparticles are highly effective in inducing autophagy, a cellular disposal mechanism that is often activated when the cell is under stress. Conclusion We suggest that these image-based assays provide a method of screening for the biological effects of similar compounds that is both efficient and sensitive as well as do not involve the use of animals.

  19. State-of-the-art exposure chamber for highly controlled and reproducible THz biological effects studies

    Science.gov (United States)

    Cerna, Cesario Z.; Elam, David P.; Echchgadda, Ibtissam; Sloan, Mark A.; Wilmink, Gerald J.

    2014-03-01

    Terahertz (THz) imaging and sensing technologies are increasingly being used at international airports for security screening purposes and at major medical centers for cancer and burn diagnosis. The emergence of new THz applications has directly resulted in an increased interest regarding the biological effects associated with this frequency range. Knowledge of THz biological effects is also desired for the safe use of THz systems, identification of health hazards, and development of empirically-based safety standards. In this study, we developed a state-of-the-art exposure chamber that allowed for highly controlled and reproducible studies of THz biological effects. This innovative system incorporated an industry grade cell incubator system that permitted a highly controlled exposure environment, where temperatures could be maintained at 37 °C +/- 0.1 °C, carbon dioxide (CO2) levels at 5% +/- 0.1%, and relative humidity (RH) levels at 95% +/- 1%. To maximize the THz power transmitted to the cell culture region inside the humid incubator, a secondary custom micro-chamber was fabricated and incorporated into the system. This micro-chamber shields the THz beam from the incubator environment and could be nitrogen-purged to eliminate water absorption effects. Additionally, a microscope that allowed for real-time visualization of the live cells before, during, and after THz exposure was integrated into the exposure system.

  20. Matrix effects in biological SIMS using cluster ion beams of different chemical composition.

    Science.gov (United States)

    Alnajeebi, Afnan M; Vickerman, John C; Lockyer, Nicholas P

    2016-06-01

    The influence of the matrix effect on secondary ion yield presents a very significant challenge in quantitative secondary ion mass spectrometry (SIMS) analysis, for example, in determining the relative concentrations of metabolites that characterize normal biological activities or disease progression. Not only the sample itself but also the choice of primary ion beam may influence the extent of ionization suppression/enhancement due to the local chemical environment. In this study, an assessment of ionization matrix effects was carried out on model systems using C60 (+), Arn (+), and (H2O)n (+) cluster ion beams. The analytes are pure and binary mixtures of amino acids arginine and histidine biological standards. Ion beams of 20 keV were compared with a range of cluster sizes n = 1000-10 000. The component secondary ion yields were assessed for matrix effects using different primary ion beams and sample composition. The presence of water in the cluster beam is associated with a reduction in the observed matrix effects, suggesting that chemically reactive ion beams may provide a route to more quantitative SIMS analysis of complex biological systems. PMID:26825287

  1. Biological effects of technetium-99 m and technetium 99 in Escherichia Coli and Salmonella typhimurium cultures

    International Nuclear Information System (INIS)

    The biological effects of the 99m Tc of the 99m Tc and 99 Tc and 99m Tc and 99 Tc on Escherichia coli (K12S, BW 9091 and AB 2463) and Salmonella typhimurium (TA 97, TA 98, TA 100 and TA 102) cultures are studied. The suggest that: Auger and or internal conversion electrons are very relevant to the 99m Tc induced inactivation effects, the pre-treatment with metal ion chelator or Sn Cl2 confers cells protection against the lethal effects of 99m Tc and the 99 Tc is a weak genotoxic and it is not mutagenic agent. (author). 25 refs, 3 figs, 3 tabs

  2. Genomic instability and bystander effects: a paradigm shift in radiation biology?

    Science.gov (United States)

    Morgan, William F.

    2002-01-01

    A basic paradigm in radiobiology is that, following exposure to ionizing radiation, the deposition of energy in the cell nucleus and the resulting damage to DNA, the principal target, are responsible for the radiation's deleterious biological effects. Findings in two rapidly expanding fields of research--radiation-induced genomic instability and bystander effects--have caused us to reevaluate these central tenets. In this article, the potential influence of induced genomic instability and bystander effects on cellular injury after exposure to low-level radiation will be reviewed.

  3. Effective and sustainable biologic treatment of psoriasis: what can we learn from new clinical data?

    Science.gov (United States)

    Langley, R G

    2012-03-01

    The introduction of the biologic agents, adalimumab, etanercept, infliximab and ustekinumab, has provided more options for the short- and long-term treatment of patients with psoriasis. Physicians are now able to achieve and maintain effective disease control in more patients using biologic therapies. Newly published clinical data support the introduction of novel optimization strategies to further improve outcomes in patients with psoriasis. Recent randomized controlled clinical trials have provided data on the efficacy of conventional therapies, including systemic agents, and biologics at specific time points. Switching from methotrexate to a tumour necrosis factor (TNF)-α antagonist after 16 weeks can improve response rates, as demonstrated in a study of patients with moderate-to-severe psoriasis, while the benefit of long-term methotrexate use remains unclear. In a separate study, psoriasis area and severity index (PASI) ≥ 75 response rates were maintained over time (>3 years for adalimumab), suggesting that long-term biologic therapy is an effective and sustainable treatment option for psoriasis. For each individual patient, the benefit of a particular treatment needs to be balanced with the risks. The lack of head-to-head trials of antipsoriatic therapies, particularly biologic therapies, does not help with making individualized treatment decisions. However, a benefit-risk assessment of TNF-α antagonists calculated from an integrated analysis of published literature in moderate-to-severe psoriasis can be used to aid clinical practice. The number needed to treat, number needed to harm and number of patient years of observation to detect an adverse event have been determined for adalimumab, etanercept and infliximab. The benefit-risk profiles generated demonstrated that, during the initial year of treatment, likelihood of success with TNF-α antagonists was several orders of magnitude greater than the likelihood of serious toxicity. PMID:22356632

  4. 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

    Library, MEDLINE, and EMBASE (to January 2010). Identifying search results and data extraction were performed independently and in duplicate. For the network meta-analysis, we performed mixed-effects logistic regression using an arm-based, random-effects model within an empirical Bayes framework. Main...... results We included 163 RCTs with 50,010 participants and 46 extension studies with 11,954 participants. The median duration of RCTs was six months and 13 months for OLEs. Data were limited for tuberculosis (TB) reactivation, lymphoma, and congestive heart failure. Adjusted for dose, biologics as a group...... increased risk of TB reactivation (OR 4.68, 95% CI 1.18 to 18.60; NNTH = 681, 95% CI 143 to 14706) compared to control. The rate of serious adverse events, serious infections, lymphoma, and congestive heart failure were not statistically significantly different between biologics and control treatment...

  5. Characterization of the angular memory effect of scattered light in biological tissues

    CERN Document Server

    Schott, Sam; Léger, Jean-Francois; Bourdieu, Laurent; Gigan, Sylvain

    2015-01-01

    High resolution optical microscopy is essential in neuroscience but suffers from scattering in biological tissues. It therefore grants access to superficial layers only. Recently developed techniques use scattered photons for imaging by exploiting angular correlations in transmitted light and could potentially increase imaging depths. But those correlations (`angular memory effect') are of very short range and, in theory, only present behind and not inside scattering media. From measurements on neural tissues and complementary simulations, we find that strong forward scattering in biological tissues can enhance the memory effect range (and thus the possible field-of-view) by more than an order of magnitude compared to isotropic scattering for $\\sim$1\\,mm thick tissue layers.

  6. 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;

    In the Baltic Sea Action Plan the urgent need to develop biological effects monitoring of hazardous substances and the assessment of ecosystem health has been clearly indicated. These goals will be tackled in the newly launched BEAST project (Biological Effects of Anthropogenic Chemical Stress......: 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...

  7. Effects of prednisone, aspirin, and acetaminophen on an in vivo biologic response to interferon in humans.

    Science.gov (United States)

    Witter, F R; Woods, A S; Griffin, M D; Smith, C R; Nadler, P; Lietman, P S

    1988-08-01

    In healthy volunteers receiving a single intramuscular dose of 18 X 10(6) U interferon alone or after 24 hours of an 8-day course of prednisone (40 mg/day), aspirin (650 mg every 4 hours), or acetaminophen (650 mg every 4 hours), the magnitude of the biologic response to interferon was quantified by measuring the time course of the induction of 2'-5'-oligoadenylate synthetase and resistance to vesicular stomatitis virus infection in human peripheral blood mononuclear cells. Prednisone decreased the AUC of 2'-5'-oligoadenylate synthetase activity (p less than 0.05), whereas administration of aspirin or acetaminophen did not affect this biologic response. No measurable effect was seen during administration of prednisone, aspirin, or acetaminophen on the duration or intensity of vesicular stomatitis virus yield reduction. The side effects seen with interferon administration at the dose tested were not altered in a clinically meaningful manner by prednisone, aspirin, or acetaminophen. PMID:2456175

  8. Effect of host and food availability on the biological characteristics of Trichogramma galloi Zucchi (Hymenoptera, Trichogrammatidae)

    International Nuclear Information System (INIS)

    Effect of host and food availability on the biological characteristics of Trichogramma galloi Zucchi (Hymenoptera, Trichogrammatidae). Biological characteristics of Trichogramma galloi Zucchi, 1988 were evaluated in laboratory where these parasitoids were reared on eggs of Diatraea saccharalis (Lepidoptera, Pyralidae) with or without honey, and exposed to eggs of the host after 0, 6, 12, 24, 36, 48, 60, 72 and 84 hours of emergence. The parasitism rate and viability showed higher for individuals that received food. The sex ratio was not influenced by food. The number of individuals per egg only showed difference for those adults that did not receive food and stayed six hours without the host eggs. Checking the effect of the availability of eggs, only the sex ratio, with or without honey, did not show differences. The results show that T. galloi needs a carbohydrate supply and the time can influence the reproductive capacity. (author)

  9. Effects of fumonisin B1 on selected biological responses and performance of broiler chickens

    OpenAIRE

    Ricardo H. Rauber; Maurício S. Oliveira; Adriano O. Mallmann; Paulo Dilkin; Carlos A. Mallmann; Leandro Z. Giacomini; Vladimir P. Nascimento

    2013-01-01

    The objective of this study was to determine the effects of three doses of fumonisin B1 (0, 100, and 200mg/kg of feed) on biological variables (relative weight of liver [RWL], total plasma protein [TPP], albumin [Alb], calcium [Ca], phosphorus [P], uric acid [UA], alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma glutamyltransferase [GGT], alkaline phosphatase [AP], total cholesterol [Chol], triglycerides [Tri], sphinganine-to-sphingosine ratio [SA:SO], and C-reactive pr...

  10. Relative Biological Effectiveness of HZE Particles for Chromosomal Exchanges and Other Surrogate Cancer Risk Endpoints

    OpenAIRE

    Cacao, Eliedonna; Hada, Megumi; Saganti, Premkumar B.; George, Kerry A.; Francis A Cucinotta

    2016-01-01

    The biological effects of high charge and energy (HZE) particle exposures are of interest in space radiation protection of astronauts and cosmonauts, and estimating secondary cancer risks for patients undergoing Hadron therapy for primary cancers. The large number of particles types and energies that makeup primary or secondary radiation in HZE particle exposures precludes tumor induction studies in animal models for all but a few particle types and energies, thus leading to the use of surrog...

  11. The effect of key process operational conditions on enhanced biological phosphorus removal from wastewater

    OpenAIRE

    Carvalheira, Mónica Isabel Gonçalves

    2014-01-01

    Enhanced biological phosphorus removal (EBPR) is the most economic and sustainable option used in wastewater treatment plants (WWTPs) for phosphorus removal. In this process it is important to control the competition between polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs), since EBPR deterioration or failure can be related with the proliferation of GAOs over PAOs. This thesis is focused on the effect of operational conditions (volatile fatty acid (VFA) c...

  12. Biological effects monitoring of the discharge water from the Ormen Lange gas facility, Norway

    OpenAIRE

    Brooks, S.; C. Harman

    2009-01-01

    The mussel, Mytilus edulis has been used to assess the biological effects of produced water (PW) discharged from the Ormen Lange gas processing plant on the West coast of Norway. An integrated monitoring approach was applied, using a combination of sensitive health index parameters in the mussel including lysosomal membrane stability (LMS) and micronuclei (MN) formation in haemocytes of live mussels, cell type composition, lysosomal membrane stability and peroxisome proliferators in mussel di...

  13. Effect of Hydraulic Retention Time on Nitrification in an AirLift Biological Reactor

    OpenAIRE

    Furtado A.A.L.; Albuquerque R.T.; Leite S.G.F.; Peçanha R.P.

    1998-01-01

    The occurrence of nitrogenous compounds in industrial effluents at concentration levels above legal limits, is a well-known and serious pollution problem for the receiving body. The biological process for the removal of these substances, commonly referred to as ammoniacal nitrogen, is known as nitrification. Bacteria involved are mainly of the genuses Nitrosomonas and Nitrobacter. The aim of the present work was to study the effect of the hydraulic retention time (HRT) on the efficiency of am...

  14. Biological effects of a disposable, canisterless negative pressure wound therapy system.

    OpenAIRE

    Malmsjö, Malin; Huddleston, Elizabeth; Martin, Robin

    2014-01-01

    Objective: Recent developments of negative pressure wound therapy (NPWT) systems have focused on making pumps smaller, lighter, and more portable. The recently introduced PICO system manages wound fluid through a highly breathable film within the dressing, thereby negating the need for a canister, which allows greater mobility and patient concordance. The aim of this study is to compare the biological effects of this system compared to a traditional NPWT system. Methods: Laboratory tests were...

  15. Negative Pressure Wound Therapy. Therapy Settings and Biological Effects in Peripheral Wounds

    OpenAIRE

    Borgquist, Ola

    2013-01-01

    Negative pressure wound therapy (NPWT) promotes wound healing through several mechanisms, e.g., altered periwound blood flow, mechanical deformation of the wound edge tissue, and drainage of excess fluid and debris. The general aim of this thesis was to study the impact of different levels of negative pressure, different wound filling materials (foam or gauze), and different ways of applying the negative pressure (continuously, intermittently or variably) on the biological effects of NPWT in ...

  16. Biological effects of bioactive components and extracts derived from edible plants commonly used in human nutrition

    OpenAIRE

    Danesi, Francesca

    2009-01-01

    The main aim of this PhD research project was the evaluation of the biological effects of bioactive compounds derived from edible plants, with particular attention on their possibility to counteract oxidative damage and inflammation. After a preliminary study of in vitro antioxidant activity, regarding the modification eventually occurring after home freezing and cooking of edible vegetables, cultured mammalian cells were used as experimental model systems. Soluble extract and essenti...

  17. Effects of organic amendment on soil quality as assessed by biological indicators

    OpenAIRE

    Sultana, Salma

    2011-01-01

    Soil quality decline is one of the most predominant effect deriving from human activities. In particular, intensive agricultural management can affect negatively soils, principally due to rapid depletion of soil organic matter, that affects, in turn, soil physical, chemical and biological properties. The declining trend of soil quality coupled with mismanagement of agricultural production is pose a serious threat to sustainability of intensive agriculture. Sustainable intensive agriculture is...

  18. Biological Effects of Green Tea Capsule Supplementation in Pre-Surgery Postmenopausal Breast Cancer Patients

    OpenAIRE

    StevenSYu; DarcyVSpicer; DebraHawes; Chiu-ChenTseng; ChungSYang; MalcolmCPike

    2013-01-01

    Regular green tea intake has been associated with an inverse risk of breast cancer. There is compelling experimental evidence that green tea, particularly, epigallocatechin gallate, the most potent green tea catechin, possesses a range of anti-cancer properties. We conducted a pre-surgical study of green tea capsules versus no green tea in women with primary breast cancer to determine the effects of green tea supplementation on markers of biological response. Postmenopausal women with duct...

  19. Physical Activity and Gastrointestinal Cancers: Primary and Tertiary Preventive Effects and Possible Biological Mechanisms

    OpenAIRE

    Karen Steindorf; Dorothea Clauss; Joachim Wiskemann; Schmidt, Martina E

    2015-01-01

    Gastrointestinal cancers account for 37% of all cancer deaths worldwide, underlining the need to further investigate modifiable factors for gastrointestinal cancer risk and prognosis. This review summarizes the corresponding evidence for physical activity (PA), including, briefly, possible biological mechanisms. Despite high public health relevance, there is still a scarcity of studies, especially for tertiary prevention. Besides the convincing evidence of beneficial effects of PA on colon ca...

  20. Numerical study of the electroporation pulse shape effect on molecular uptake of biological cells

    OpenAIRE

    Miklavčič, Damijan; Towhidi, Leila

    2010-01-01

    Background In order to reduce the side-effects of chemotherapy, combined chemotherapy-electroporation (electrochemotherapy) has been suggested. Electroporation, application of appropriate electric pulses to biological cells, can significantly enhance molecular uptake of cells due to formation of transient pores in the cell membrane. It was experimentally demonstrated that the efficiency of electroporation is under the control of electric pulse parameters. However, the theoretical basis for th...

  1. Biological effects of climate change: An introduction to the field and a survey of current research

    OpenAIRE

    Kristiansen, Gørill

    1993-01-01

    This report presents a survey of international (Chapter 2) as well as national research activities within 13 selected countries (Chapter 3) in the field of biological effects of climate change. In addition, a brief overview of potential changes within natural ecosystems in response to climate change is given (Chapter 1). This part is intended to serve as a quick introduction for biologists who lack previous experience with the whole or parts of the field of climate change impact studies. The ...

  2. The Biological Effects of Sex Hormones on Rabbit Articular Chondrocytes from Different Genders

    OpenAIRE

    Shwu Jen Chang; Shyh Ming Kuo; Yen Ting Lin; Shan-Wei Yang

    2014-01-01

    The aim of this study was to investigate the biological effects of sex hormones (17 β -estradiol and testosterone) on rabbit articular chondrocytes from different genders. We cultured primary rabbit articular chondrocytes from both genders with varying concentration of sex hormones. We evaluate cell proliferation and biochemical functions by MTT and GAG assay. The chondrocyte function and phenotypes were analyzed by mRNA level using RT-PCR. Immunocytochemical staining was also used to evaluat...

  3. Study of cardiovascular disease biomarkers among tobacco consumers, part 2: biomarkers of biological effect

    OpenAIRE

    Nordskog, Brian K.; Brown, Buddy G.; Marano, Kristin M.; Campell, Leanne R.; Jones, Bobbette A.; Borgerding, Michael F.

    2015-01-01

    Abstract An age-stratified, cross-sectional study was conducted in the US among healthy adult male cigarette smokers, moist snuff consumers, and non-tobacco consumers to evaluate cardiovascular biomarkers of biological effect (BoBE). Physiological assessments included flow-mediated dilation, ankle-brachial index, carotid intima-media thickness and expired carbon monoxide. Approximately one-half of the measured serum BoBE showed statistically significant differences; IL-12(p70), sICAM-1 and IL...

  4. Effect of the flavonoid rutin on the biology of Spodoptera frugiperda (Lepidoptera: Noctuidae

    Directory of Open Access Journals (Sweden)

    Talita Roberta Ferreira Borges Silva

    2016-04-01

    Full Text Available The fall armyworm Spodoptera frugiperda (J.E. Smith (Lepidoptera: Noctuidae is a major pest of maize crops in Brazil. The effects of plant metabolites on the biology and behavior of insects is little studied. The aim of the study was to evaluate the activity of rutin on the biology of the S. frugiperda by using artificial diets containing rutin. The study evaluated four treatments: regular diet (control group and diets containing 1.0, 2.0 and 3.0 mg g-1 of rutin. The following biological variables parameters of the larvae were evaluated daily: development time (days, larval and pupal weight (g and viability (%, adult longevity and total life cycle (days. A completely randomized experimental design was used with 25 replication. The rutin flavonoid negatively affected the biology of S. frugiperda by prolonging the larval development time, reducing the weight of larvae and pupae and decreasing the viability of the pupae. The addition of different concentrations of rutin prolonged the S. frugiperda life cycle. The use of plant with insecticidal activity has the potential with strategy in IPM.

  5. The effect of initial density and parasitoid intergenerational survival rate on classical biological control

    International Nuclear Information System (INIS)

    Models of biological control have a long history of theoretical development that have focused on the interaction of a parasitoid and its host. The host-parasitoid systems have identified several important and general factors affecting the long-term dynamics of interacting populations. However, much less is known about how the initial densities of host-parasitoid populations affect the biological control as well as the stability of host-parasitoid systems. To do this, the classical Nicholson-Bailey model with host self-regulation and parasitoid intergenerational survival rate is used to uncover the effect of initial densities on the successful biological control. The results indicate that the simplest Nicholson-Bailey model has various coexistence with a wide range of parameters, including boundary attractors where the parasitoid population is absent and interior attractors where host-parasitoid coexists. The final stable states of host-parasitoid populations depend on their initial densities as well as their ratios, and those results are confirmed by basins of attraction of initial densities. The results also indicate that the parasitoid intergenerational survival rate increases the stability of the host-parasitoid systems. Therefore, the present research can help us to further understand the dynamical behavior of host-parasitoid interactions, to improve the classical biological control and to make management decisions

  6. Five task clusters that enable efficient and effective digitization of biological collections.

    Science.gov (United States)

    Nelson, Gil; Paul, Deborah; Riccardi, Gregory; Mast, Austin R

    2012-01-01

    This paper describes and illustrates five major clusters of related tasks (herein referred to as task clusters) that are common to efficient and effective practices in the digitization of biological specimen data and media. Examples of these clusters come from the observation of diverse digitization processes. The staff of iDigBio (The U.S. National Science Foundation's National Resource for Advancing Digitization of Biological Collections) visited active biological and paleontological collections digitization programs for the purpose of documenting and assessing current digitization practices and tools. These observations identified five task clusters that comprise the digitization process leading up to data publication: (1) pre-digitization curation and staging, (2) specimen image capture, (3) specimen image processing, (4) electronic data capture, and (5) georeferencing locality descriptions. While not all institutions are completing each of these task clusters for each specimen, these clusters describe a composite picture of digitization of biological and paleontological specimens across the programs that were observed. We describe these clusters, three workflow patterns that dominate the implemention of these clusters, and offer a set of workflow recommendations for digitization programs. PMID:22859876

  7. Five task clusters that enable efficient and effective digitization of biological collections

    Directory of Open Access Journals (Sweden)

    Gil Nelson

    2012-07-01

    Full Text Available This paper describes and illustrates five major clusters of related tasks (herein referred to as task clusters that are common to efficient and effective practices in the digitization of biological specimen data and media. Examples of these clusters come from the observation of diverse digitization processes. The staff of iDigBio (The U.S. National Science Foundation’s National Resource for Advancing Digitization of Biological Collections visited active biological and paleontological collections digitization programs for the purpose of documenting and assessing current digitization practices and tools. These observations identified five task clusters that comprise the digitization process leading up to data publication: (1 pre-digitization curation and staging, (2 specimen image capture, (3 specimen image processing, (4 electronic data capture, and (5 georeferencing locality descriptions. While not all institutions are completing each of these task clusters for each specimen, these clusters describe a composite picture of digitization of biological and paleontological specimens across the programs that were observed. We describe these clusters, three workflow patterns that dominate the implemention of these clusters, and offer a set of workflow recommendations for digitization programs.

  8. The Experimental Measurement of the Relative Biological Effectiveness of Carbon Ions with Different Qualities

    Institute of Scientific and Technical Information of China (English)

    WANG Jufang; LI Wenjian

    2008-01-01

    The relative biological effectiveness (RBE) of carbon ions with linear energy transfer (LET) of 172 keV/μm and 13.7 keV/μm were determined in this study. The clonogenic survival and premature terminal differentiation were measured on normal human fibroblasts AG01522C and NHDF after exposure of the cells to 250 kV X-rays and carbon ions with different qualities. RBE was determined for these two biological end points. The results showed that the measured RBE10 with a survival fraction of 10% was 3.2 for LET 172 keV/μm, and 1.33 for LET 13.7 keV/μm carbon ions. RBE for a doubling of post-mitotic fibroblasts (PMF) in the population was 2.8 for LET 172 keV/μm, and 1 for LET 13.7 keV/μm carbon ions. For the carbon ion therapy, a high RBE value on the Bragg peak results in a high biological dose on the tumour. The tumour cells can be killed effectively. At the same time, the dose on healthy tissue would be reduced accordingly. This will lighten the late effect such as fibrosis on normal tissue.

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

    International Nuclear Information System (INIS)

    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.

  10. Analysis of MIR-18 results for physical and biological dosimetry: radiation shielding effectiveness in LEO

    International Nuclear Information System (INIS)

    We compare models of radiation transport and biological response to physical and biological dosimetry results from astronauts on the Mir space station. Transport models are shown to be in good agreement with physical measurements and indicate that the ratio of equivalent dose from the Galactic Cosmic Rays (GCR) to protons is about 3/2:1 and that this ratio will increase for exposures to internal organs. Two biological response models are used to compare to the Mir biodosimetry for chromosome aberration in lymphocyte cells; a track-structure model and the linear-quadratic model with linear energy transfer (LET) dependent weighting coefficients. These models are fit to in vitro data for aberration formation in human lymphocytes by photons and charged particles. Both models are found to be in reasonable agreement with data for aberrations in lymphocytes of Mir crew members: however there are differences between the use of LET dependent weighting factors and track structure models for assigning radiation quality factors. The major difference in the models is the increased effectiveness predicted by the track model for low charge and energy ions with LET near 10 keV/μm. The results of our calculations indicate that aluminum shielding, although providing important mitigation of the effects of trapped radiation, provides no protective effect from the galactic cosmic rays (GCR) in low-earth orbit (LEO) using either equivalent dose or the number of chromosome aberrations as a measure until about 100 g/cm2 of material is used

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

    International Nuclear Information System (INIS)

    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)

  12. New insight into the molecular mechanisms of the biological effects of DNA minor groove binders.

    Directory of Open Access Journals (Sweden)

    Xinbo Zhang

    Full Text Available BACKGROUND: Bisbenzimides, or Hoechst 33258 (H258, and its derivative Hoechst 33342 (H342 are archetypal molecules for designing minor groove binders, and widely used as tools for staining DNA and analyzing side population cells. They are supravital DNA minor groove binders with AT selectivity. H342 and H258 share similar biological effects based on the similarity of their chemical structures, but also have their unique biological effects. For example, H342, but not H258, is a potent apoptotic inducer and both H342 and H258 can induce transgene overexpression in in vitro studies. However, the molecular mechanisms by which Hoechst dyes induce apoptosis and enhance transgene overexpression are unclear. METHODOLOGY/PRINCIPAL FINDINGS: To determine the molecular mechanisms underlying different biological effects between H342 and H258, microarray technique coupled with bioinformatics analyses and multiple other techniques has been utilized to detect differential global gene expression profiles, Hoechst dye-specific gene expression signatures, and changes in cell morphology and levels of apoptosis-associated proteins in malignant mesothelioma cells. H342-induced apoptosis occurs in a dose-dependent fashion and is associated with morphological changes, caspase-3 activation, cytochrome c mitochondrial translocation, and cleavage of apoptosis-associated proteins. The antagonistic effect of H258 on H342-induced apoptosis indicates a pharmacokinetic basis for the two dyes' different biological effects. Differential global gene expression profiles induced by H258 and H342 are accompanied by unique gene expression signatures determined by DNA microarray and bioinformatics software, indicating a genetic basis for their different biological effects. CONCLUSIONS/SIGNIFICANCE: A unique gene expression signature associated with H342-induced apoptosis provides a new avenue to predict and classify the therapeutic class of minor groove binders in the drug

  13. Metastatic renal cell carcinoma: can it be palliated with radiotherapy? Do higher biologically effective doses help?

    International Nuclear Information System (INIS)

    BACKGROUND: Renal cell carcinoma (RCC) has traditionally been regarded as a 'radioresistant cancer'. Yet controversy exists as to whether dose escalation can overcome the inherent resistance of such tumors when they metastasize. Using a Tumor Dose Factor (TDF) model, Onuffrey et al. (IJROB 11:2007, 1985) showed that TDF >70 was predictive of higher palliative response rates. In contrast, Halperin et al (Cancer 51:614, 1983) could not establish a correlation between TDF equivalent dose and frequency of palliative response. Since that time, the linear quadratic model has emerged as an alternative paradigm for biologically effective dose (BED). The current project was undertaken to determine the ability of radiotherapy to palliate focally metastatic RCC and to assess whether the delivery of higher biologically effective dose was more likely to bring about complete palliative response (CR). METHODS: Between 1966 and 1995, 107 patients with renal cell metastases at 150 sites were irradiated with palliative intent. Sites irradiated included bone (n=89), soft tissue (n=16), brain (n=20), spinal cord (n=9), and pulmonary (n=16). To determine dose effectiveness, the biological effective dose (BED) was calculated according to the following formula Gy10 = Total Dose (1 + fractional dose/α-β) using an α-β of 10. The above table presents univariate comparisons. For the entire series, 94% of patients derived a palliative response after treatment with irradiation. The median duration of palliation was 4 months (range, 2-80 months). With respect to overall response, only patients with metastases to the spinal cord were significantly less likely to derive palliation in multivariate analysis (p70) and the rate of CR (p=0.03). When entered as a dichotomous variable (e.g., relative to 39 Gy 10) increasing biologically effective dose was not associated with an increased rate of complete palliation; however, when entered as a continuous variable, increasing BED was strongly

  14. Effectiveness of Biologic and Conventional Systemic Therapies in Adults with Chronic Plaque Psoriasis in Daily Practice: A Systematic Review.

    Science.gov (United States)

    Zweegers, Jeffrey; Otero, Marisol E; van den Reek, Juul M P A; van Lümig, Paula P; Driessen, Rieke J; Kievit, Wietske; Seyger, Marieke M B; van de Kerkhof, Peter C M; de Jong, Elke M G J

    2016-04-12

    The efficacy of biologic or conventional systemic therapies for psoriasis has been shown in randomized controlled trials. Effectiveness, however, has been studied in daily practice cohorts, and no aggregation of effectiveness data is available. This systematic review searched PubMed and EMBASE and summarized the real-world evidence on effectiveness of biologics (adalimumab, etanercept, infliximab and ustekinumab) and conventional systemic therapies (acitretin, cyclosporine, fumarates and methotrexate) for the treatment of plaque psoriasis in adults. Thirty-two studies were included. Few data were available on infliximab, ustekinumab and conventional systemics. Results show that biologics and conventional systemics were effective in real-life treatment of psoriasis, with large ranges in the percentage of patients reaching 75% improvement in psoriasis area and severity index score compared with baseline, especially for etanercept and adalimumab treatment. Combination therapies of biologics with conventional systemics, and dose adjustments of biologics were frequently applied strategies and may explain the large range in improvements between cohorts. PMID:26537336

  15. Novel biological approaches for testing the contributions of single-DSBs and DSB-clusters to the biological effects of high-LET-radiation

    Directory of Open Access Journals (Sweden)

    Veronika eMladenova

    2016-06-01

    Full Text Available The adverse biological effects of ionizing radiation (IR are commonly attributed to the generation of DNA double-strand-breaks (DSBs. IR-induced DSBs are generated by clusters of ionizations, bear damaged terminal nucleotides and frequently comprise base damages and single strand breaks in the vicinity generating a unique DNA damage-clustering effect that increases DSB complexity. The number of ionizations in clusters of different radiation modalities increases with increasing linear-energy-transfer (LET, and is thought to determine the long-known LET-dependence of the relative biological effectiveness (RBE. Multiple ionizations may also lead to the formation of DSB-clusters comprising two or more DSBs that destabilize chromatin further and compromise overall processing. DSB complexity and DSB-cluster formation are increasingly considered in the development of mathematical models of radiation action, which are then tested by fitting available experimental data. Despite a plethora of such mathematical models the ultimate goal, i.e. the a-priori prediction of the radiation effect, has not yet been achieved. The difficulty partly arises from unsurmountable difficulties in testing the fundamental assumptions of such mathematical models in defined biological model systems capable of providing conclusive answers. Recently, revolutionary advances in methods allowing the generation of enzymatic DSBs at random or in well-defined locations in the genome, generate unique testing opportunities for several key assumptions frequently fed into mathematical modeling – including the role of DSB-clusters in the overall effect. Here, we review the problematic of DSB-cluster formation in radiation action and present novel biological technologies that promise to revolutionize the way we address the biological consequences of such lesions. We describe new ways of exploiting the I-SceI endonuclease to generate DSB-clusters at random locations in the genome and

  16. Biological Effects of Gamma-Ray Bursts: Critical distances for severe damage on the biota

    CERN Document Server

    Galante, D; Galante, Douglas; Horvath, Jorge Ernesto

    2005-01-01

    We present in this work a unified, quantitative synthesis of analytical and numerical calculations of the effects caused on an Earth-like planet by a Gamma-Ray Burst (GRB), considering atmospheric and biological implications. The main effects of the illumination by a GRB are classified in four distinct ones and analyzed separately, namely the direct gamma radiation transmission, UV flash, ozone layer depletion and cosmic rays. The effectiveness of each of these effects is compared and lethal distances for significant biological damage are given for each one. We find that the first three effects have potential to cause global environmental changes and biospheric damages, even if the source is located at great distances (perhaps up to ~ 100 kpc). Instead, cosmic rays would only be a serious threat for very close sources. As a concrete example of a recorded similar event, the effects of the giant flare from SGR1806-20 of Dec 27, 2004 could cause on the biosphere are addressed. In spite of not belonging to the so...

  17. The study of biological effects of electromagnetic mobile phone radiation on experimental animals by combining numerical modeling and experimental research

    Directory of Open Access Journals (Sweden)

    Dejan Krstić

    2012-12-01

    Full Text Available In order to study biological effects of electromagneticradiation, it is essential to know the real values of field componentsthat penetrated the tissue. The study of biological effects is usuallyperformed on experimental animals. The biological effects observedon experimental animals should be linked with penetrating field inthe tissue. The penetrating electromagnetic field is almost impossibleto measure; therefore, modeling process must be carried out and thefield components in models of experimental animals could becalculated. This paper presents an approach to modeling of fieldpenetration and gives contribution to understanding the real effects of the fields and the sensitivity of tissues to electromagnetic radiation generated by mobile phone.

  18. Biological and morphological effects on the reproductive organ of rats after exposure to electromagnetic field

    International Nuclear Information System (INIS)

    The biological effect of electromagnetic field (EMF) emitted from mobile phones is a current debate and still a controversial issue. Therefore, little is known on the possible adverse effects on reproduction as mobile phone bio-effects are only a very recent concern. The aim of this experimental study was to determine the biological and morphological effects of 900 MHz radiofrequency (RF) EMF on rat testes. The study was performed in the Physiology and Histology Research Laboratories of Suleyman Demirel University, Faculty of Medicine, Isparta, Turkey in May 2004. Twenty adult male Sprague-Dawley rats weighing 270-320 gm were randomized into two groups of 10 animals: Group I (control group) was not exposed to EMF and group II (EMF group) was exposed to 30 minutes per day, 5 days a week for 4 weeks to 900 MHz EMF. Testicular biopsy score count and the percentage of interstitial tissue to the entire testicular tissue were registered. Serum testosterone, plasma luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels were assayed biochemically. The weight of testes testicular biopsy score count and the percentage of interstitial tissue to the entire testicular tissue were not significantly different in EMF group compared to the control group. However, the diameter of the seminiferous tubules and the mean height of the germinal epithelium were significantly decreased in EMF group (p0.05). The biological and morphological effects resulting from 900 MHz RF EMF exposure lends no support to suggestions of adverse effect on the spermatogenesis, and on germinal epithelium. Therefore, testicular morphologic alterations may possibly be due to the hormonal changes. (author)

  19. Comparing Effects of Biologic Agents in Treating Patients with Rheumatoid Arthritis: A Multiple Treatment Comparison Regression Analysis.

    Directory of Open Access Journals (Sweden)

    Ingunn Fride Tvete

    Full Text Available Rheumatoid arthritis patients have been treated with disease modifying anti-rheumatic drugs (DMARDs and the newer biologic drugs. We sought to compare and rank the biologics with respect to efficacy. We performed a literature search identifying 54 publications encompassing 9 biologics. We conducted a multiple treatment comparison regression analysis letting the number experiencing a 50% improvement on the ACR score be dependent upon dose level and disease duration for assessing the comparable relative effect between biologics and placebo or DMARD. The analysis embraced all treatment and comparator arms over all publications. Hence, all measured effects of any biologic agent contributed to the comparison of all biologic agents relative to each other either given alone or combined with DMARD. We found the drug effect to be dependent on dose level, but not on disease duration, and the impact of a high versus low dose level was the same for all drugs (higher doses indicated a higher frequency of ACR50 scores. The ranking of the drugs when given without DMARD was certolizumab (ranked highest, etanercept, tocilizumab/ abatacept and adalimumab. The ranking of the drugs when given with DMARD was certolizumab (ranked highest, tocilizumab, anakinra/rituximab, golimumab/ infliximab/ abatacept, adalimumab/ etanercept [corrected]. Still, all drugs were effective. All biologic agents were effective compared to placebo, with certolizumab the most effective and adalimumab (without DMARD treatment and adalimumab/ etanercept (combined with DMARD treatment the least effective. The drugs were in general more effective, except for etanercept, when given together with DMARDs.

  20. Cost-effective management alternatives for Snake river chinook salmon: A biological-economic synthesis

    Science.gov (United States)

    Halsing, D.L.; Moore, M.R.

    2008-01-01

    The mandate to increase endangered salmon populations in the Columbia River Basin of North America has created a complex, controversial resource-management issue. We constructed an integrated assessment model as a tool for analyzing biological-economic trade-offs in recovery of Snake River spring- and summer-run chinook salmon (Oncorhynchus tshawytscha). We merged 3 frameworks: a salmon-passage model to predict migration and survival of smolts; an age-structured matrix model to predict long-term population growth rates of salmon stocks; and a cost-effectiveness analysis to determine a set of least-cost management alternatives for achieving particular population growth rates. We assessed 6 individual salmon-management measures and 76 management alternatives composed of one or more measures. To reflect uncertainty, results were derived for different assumptions of effectiveness of smolt transport around dams. Removal of an estuarine predator, the Caspian Tern (Sterna caspia), was cost-effective and generally increased long-term population growth rates regardless of transport effectiveness. Elimination of adult salmon harvest had a similar effect over a range of its cost estimates. The specific management alternatives in the cost-effective set depended on assumptions about transport effectiveness. On the basis of recent estimates of smolt transport effectiveness, alternatives that discontinued transportation or breached dams were prevalent in the cost-effective set, whereas alternatives that maximized transportation dominated if transport effectiveness was relatively high. More generally, the analysis eliminated 80-90% of management alternatives from the cost-effective set. Application of our results to salmon management is limited by data availability and model assumptions, but these limitations can help guide research that addresses critical uncertainties and information. Our results thus demonstrate that linking biology and economics through integrated models can

  1. Lethal and Sublethal Effects of Fenpropathrin on the Biological Performance of Scolothrips longicornis (Thysanoptera: Thripidae)

    DEFF Research Database (Denmark)

    Pakyari, Hajar; Enkegaard, Annie

    2013-01-01

    affected the biological characteristics of treated females of S. longicornis, the most noticeable effects being a shortening of female life span by >70% accompanied by large reductions in oviposition period and fecundity. The offspring of females treated with low-lethal concentrations of fenpropathrin...... likewise had significantly reduced longevity, oviposition period, and fecundity, although not to the same extent as experienced by their mothers. Their juvenile development time was, however, not affected. These effects on the offspring were reflected in reduced rates of population increase and increased...

  2. Effects of temperature and relative humidity on biological indicators used for ethylene oxide sterilization.

    OpenAIRE

    Oxborrow, G. S.; Placencia, A M; Danielson, J W

    1983-01-01

    A study was made to determine the effects of temperature and moisture on the D-value of a common biological indicator. Relative humidity (RH) was varied between 10 and 70% in increments of 10%, and temperature was varied between 30 and 70 degrees C in increments of 10 degrees C. Temperature was found to have a pronounced effect on the D-value. At 60% RH, the D-value varied from 15.0 min at 30 degrees C to 1.1 min at 70 degrees C. When RH was plotted against the average D-value at the various ...

  3. A study of biological effect on plants caused by ion implantation

    International Nuclear Information System (INIS)

    Seeds of maize, rice, wheat, rye etc were implanted by nitrogen or phosphorus ions with energy of 35 to 180 keV. The effects on germination percentage, growth speed and plant type were investigated. In the observation of chromosomes, the characters of chromosomes were found normal in mitoses, but abnormal in some meioses. The distributions of implanted ions in seeds were measured by RBS and calculated with TRIM program. The mechanism of biological effects induced by ion implantation and the prospect for application were discussed

  4. Carryover effect of postpartum inflammatory diseases on developmental biology and fertility in lactating dairy cows.

    Science.gov (United States)

    Ribeiro, E S; Gomes, G; Greco, L F; Cerri, R L A; Vieira-Neto, A; Monteiro, P L J; Lima, F S; Bisinotto, R S; Thatcher, W W; Santos, J E P

    2016-03-01

    The objective of this series of studies was to investigate the effects of inflammatory diseases occurring before breeding on the developmental biology and reproductive responses in dairy cows. Data from 5 studies were used to investigate different questions associating health status before breeding and reproductive responses. Health information for all studies was composed of the incidence of retained fetal membranes, metritis, mastitis, lameness, and respiratory and digestive problems from parturition until the day of breeding. Retained placenta and metritis were grouped as uterine disease (UTD). Mastitis, lameness, digestive and respiratory problems were grouped as nonuterine diseases (NUTD). Study 1 evaluated the effect of disease before artificial insemination (AI), anovulation before synchronization of the estrous cycle, and low body condition score at AI on pregnancy per AI, as well as their potential interactions or additive effects. Study 2 investigated the effect of site of inflammation (UTD vs. NUTD) and time of occurrence relative to preantral or antral stages of ovulatory follicle development, and the effect of UTD and NUTD on fertility responses of cows bred by AI or by embryo transfer. Study 3 evaluated the effect of disease on fertilization and embryonic development to the morula stage. Study 4 evaluated the effect of disease on preimplantation conceptus development as well as secretion of IFN-τ and transcriptome. Study 5 investigated the effect of diseases before AI on the transcript expression of interferon-stimulated genes in peripheral blood leukocytes during peri-implantation stages of conceptus development after first AI postpartum. Altogether, these studies demonstrated that inflammatory disease before breeding reduced fertilization of oocytes and development to morula, and impaired early conceptus development to elongation stages and secretion of IFN-τ in the uterine lumen. Diseases caused inflammation-like changes in transcriptome of

  5. Effects of physical therapy for the management of patients with ankylosing spondylitis in the biological era.

    Science.gov (United States)

    Giannotti, Erika; Trainito, Sabina; Arioli, Giovanni; Rucco, Vincenzo; Masiero, Stefano

    2014-09-01

    Exercise is considered a fundamental tool for the management of ankylosing spondylitis (AS), in combination with pharmacological therapy that with the advent of biological therapy has improved dramatically the control of signs and symptoms of this challenging disease. Current evidence shows that a specific exercise protocol has not been validated yet. The purpose of this review is to update the most recent evidence (July 2010-November 2013) about physiotherapy in AS, analyzing the possible role and synergistic interactions between exercise and biological drugs. From 117 studies initially considered, only 15 were included in the review. The results support a multimodal approach, including educational sessions, conducted in a group setting, supervised by a physiotherapist and followed by a maintaining home-based regimen. Spa exercise and McKenzie, Heckscher, and Pilates methods seem promising in AS rehabilitation, but their effectiveness should be further investigated in future randomized controlled trials (RCTs). When performed in accordance with the American College of Sports Medicine guidelines, cardiovascular training has been proven safe and effective and should be included in AS rehabilitation protocols. Exercise training plays an important role in the biological era, being now applicable to stabilized patients, leading ultimately to a better management of AS by physiatrists and rheumatologists throughout the world. On the basis of the current evidence, further research should aim to determine which exercise protocols should be recommended. PMID:24797772

  6. High school teachers' perspectives on effective approaches for teaching biology to students with special needs

    Science.gov (United States)

    Kos, Agnieszka

    The demands of national educational reforms require high school biology teachers to provide high quality instruction to students with and without special needs. The reforms, however, do not provide teachers with adequate teaching strategies to meet the needs of all students in the same context. The purpose of this grounded theory study was to understand high school biology teachers' perspectives, practices, and challenges in relation to teaching students with special needs. This approach was used to develop a substantive model for high school biology teachers who are challenged with teaching students with and without special needs. Data were collected via in-depth interviews with 15 high school teachers in a Midwestern school district. The data were analyzed using open coding, axial coding, and selective coding procedures in accordance with the grounded theory approach. Essential model components included skills and training for teachers, classroom management strategies, teaching strategies, and student skills. The emergent substantive theory indicated that that teacher preparation and acquired skills greatly influence the effectiveness of inclusion implementation. Key findings also indicated the importance of using of a variety of instructional strategies and classroom management strategies that address students' special needs and their learning styles. This study contributes to social change by providing a model for teaching students and effectively implementing inclusion in regular science classrooms. Following further study, this model may be used to support teacher professional development and improve teaching practices that in turn may improve science literacy supported by the national educational reforms.

  7. The Effect of Peat and Vermicompost Cavitation Products on the Soil Biological Activity

    Directory of Open Access Journals (Sweden)

    Steinberga Vilhelmine

    2014-12-01

    Full Text Available Commercial products with humic substances have often been recommended for plant growth stimulation and yield improvement. The aim of this study was to clarify the effects of two products, containing cavited peat and vermicompost respectively on the soil biological activity. Vegetation experiments with garden cress and cucumbers were arranged in pots with a peat substratum in the greenhouses of the Latvia University of Agriculture. The plants were treated with the preparations once a month. The first treatment was done at sowing. Dose of 20, 2, 0.2 mL per m2 during each treatment time were used. A control variant was without peat or vermicompost preparation. Field experiments with onions were carried out in the organic farming experimental field of the Latvia State Institute of Cereal Breeding. Plant growth and soil (substratum biological activity (respiration and enzymatic activity were tested. Plant growth and response to the different preparations depended on the plant species and its development stage. The effect of preparations decreases during plant development. The impact of peat or vermicompost preparation on soil biological activity depended not only on the concentration of preparation, but was influenced by the soil or growth media type. The decrease of onion yield in field conditions as a result of preparations was observed.

  8. Untangling the biological effects of cerium oxide nanoparticles: the role of surface valence states

    Science.gov (United States)

    Pulido-Reyes, Gerardo; Rodea-Palomares, Ismael; Das, Soumen; Sakthivel, Tamil Selvan; Leganes, Francisco; Rosal, Roberto; Seal, Sudipta; Fernández-Piñas, Francisca

    2015-10-01

    Cerium oxide nanoparticles (nanoceria; CNPs) have been found to have both pro-oxidant and anti-oxidant effects on different cell systems or organisms. In order to untangle the mechanisms which underlie the biological activity of nanoceria, we have studied the effect of five different CNPs on a model relevant aquatic microorganism. Neither shape, concentration, synthesis method, surface charge (ζ-potential), nor nominal size had any influence in the observed biological activity. The main driver of toxicity was found to be the percentage of surface content of Ce3+ sites: CNP1 (58%) and CNP5 (40%) were found to be toxic whereas CNP2 (28%), CNP3 (36%) and CNP4 (26%) were found to be non-toxic. The colloidal stability and redox chemistry of the most and least toxic CNPs, CNP1 and CNP2, respectively, were modified by incubation with iron and phosphate buffers. Blocking surface Ce3+ sites of the most toxic CNP, CNP1, with phosphate treatment reverted toxicity and stimulated growth. Colloidal destabilization with Fe treatment only increased toxicity of CNP1. The results of this study are relevant in the understanding of the main drivers of biological activity of nanoceria and to define global descriptors of engineered nanoparticles (ENPs) bioactivity which may be useful in safer-by-design strategies of nanomaterials.

  9. Investigation of biological effects of some Mannich Bases containing Bis-1,2,4- Triazole.

    Science.gov (United States)

    Parlak, A E; Celik, S; Karatepe, M; Turkoglu, S; Alayunt, N O; Dastan, S D; Ulas, M; Sandal, S; Tekin, S; Koparir, M

    2016-01-01

    In this study, the effects of Mannich bases containing bis-1,2,4-triazole on the levels of in vivo malondialdehyde (MDA) and antioxidant vitamins (A, E, C) were examined in serum, livers and kidneys of rats. DA and vitamin (A, E, C) levels were determined by high performance liquid chromatography (HPLC). Antioxidant effect was investigated by determining the MDA levels in Saccharomyces cerevisiae cells as in vitro. Furthermore, the antitumor effects of compounds were investigated against MCF-7 human breast cancer cells. Interrelations of results among control and compound groups were evaluated using SPSS statistical software package. As a result, some of the compounds showed effective biological activity when compared to control conditions. The test compounds used in this study may be effective for utilization in the selection and design of model compounds for further studies. PMID:27453272

  10. Cellular burdens and biological effects on tissue level caused by inhaled radon progenies

    CERN Document Server

    Madas, Balázs G; Farkas, Árpád; Szőke, István

    2014-01-01

    In the case of radon exposure, the spatial distribution of deposited radioactive particles is highly inhomogeneous in the central airways. The objective of this research is to investigate the consequences of this heterogeneity regarding cellular burdens in the bronchial epithelium and to study the possible biological effects on tissue level. Applying a computational fluid dynamics program, the deposition distribution of inhaled radon daughters has been determined in a bronchial airway model for 23 minutes of work in the New Mexico uranium mine corresponding to 0.0129 WLM exposure. A numerical epithelium model based on experimental data has been utilized in order to quantify cellular hits and doses. Finally, a carcinogenesis model considering cell death induced cell cycle shortening has been applied to assess the biological responses. Computations present, that cellular dose may reach 1.5 Gy, which is several orders of magnitude higher than tissue dose. The results are in agreement with the histological findin...

  11. 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.

  12. Effects of mussel shell addition on the chemical and biological properties of a Cambisol.

    Science.gov (United States)

    Paz-Ferreiro, J; Baez-Bernal, D; Castro Insúa, J; García Pomar, M I

    2012-03-01

    The use of a by-product of the fisheries industry (mussel shell) combined with cattle slurry was evaluated as soil amendment, with special attention to the biological component of soil. A wide number of properties related to soil quality were measured: microbial biomass, soil respiration, net N mineralization, dissolved organic carbon, dissolved organic nitrogen, dissolved inorganic nitrogen, dehydrogenase, β-glucosidase, urease and phosphomonoesterase activities. The amendments showed an enhancement of soil biological activity and a decrease of aluminium held in the cation exchange complex. No adverse effects were observed on soil properties. Given that mussel shells are produced in coastal areas as a by-product and have to be managed as a waste and the fertility constraints in the local soils due to their low pH, our research suggest that there is an opportunity for disposing a residue into the soil and improving soil fertility. PMID:22209299

  13. Effect of solids retention time and wastewater characteristics on biological phosphorus removal

    DEFF Research Database (Denmark)

    Henze, Mogens; Aspegren, H.; Jansen, J.l.C.;

    2002-01-01

    The paper deals with the effect of wastewater, plant design and operation in relation to biological nitrogen and phosphorus removal and the possibilities to model the processes. Two Bio-P pilot plants were operated for 2.5 years in parallel receiving identical wastewater. The plants had SRT of 4...... in the wastewater, and less by the plant lay-out. The phosphorus removal is mainly dependent on availability in the wastewater of fatty acids but also by the suspended solids in the effluent, which is higher in the plant with nitrificationdenitrification, probably due to a higher SVI or denitrification...... with time which has importance in relation to modelling. The overall conclusion of the comparison between the two plants is that the biological phosphorus removal efficiency under practical operating conditions is affected by the SRT in the plant and the wastewater composition. Thus great care should...

  14. Analytical and compositional aspects of isoflavones in food and their biological effects

    DEFF Research Database (Denmark)

    Mortensen, Alicja; Kulling, Sabine E.; Schwartz, Heidi; Rowland, Ian; Rueler, Corinna E.; Rimbach, Gerald; Cassidy, Aedin; Magee, Pamela; Millar, Julie; Hall, Wendy L.; Birkved, Franziska Kramer; Sontag, Gerhard; Sørensen, Ilona Kryspin

    2009-01-01

    This paper provides an overview of analytical techniques used to determine isoflavones (IFs) in foods and biological fluids with main emphasis on sample preparation methods. Factors influencing the content of IFs in food including processing and natural variability are summarized and an insight...... into IF databases is given. Comparisons of dietary intake of IFs in Asian and Western populations, in special subgroups like vegetarians, vegans, and infants are made and our knowledge on their absorption, distribution, metabolism, and excretion by the human body is presented. The influences of the gut...... microflora, age, gender, background diet, food matrix, and the chemical nature of the IFs on the metabolism of IFs are described. Potential mechanisms by which IFs may exert their actions are reviewed, and genetic polymorphism as determinants of biological response to soy IFs is discussed. The effects of IFs...

  15. Across the Great Divide: The Effects of Technology in Secondary Biology Classrooms

    Science.gov (United States)

    Worley, Johnny Howard, II

    This study investigates the relationship between technology use and student achievement in public high school across North Carolina. The purpose of this study was to determine whether a digital divide (differences in technology utilization based on student demographics of race/ethnicity, gender, socioeconomic status, and municipality) exists among schools and whether those differences relate to student achievement in high school biology classrooms. The study uses North Carolina end-of-course (EOC) data for biology to analyze student demographic data and assessment results from the 2010-2011 school year from the North Carolina Department of Public Instruction. The data analyses use descriptive and factorial univariate statistics to determine the existence of digital divides and their effects on biology achievement. Analysis of these data described patterns of technology use to determine whether potential variances resulted in a digital divide. Specific technology uses were identified in the data and then their impact on biology achievement scores within various demographic groups was examined. Research findings revealed statistically significant variations of use within different population groups. Despite being statistically significant, the relevance of the association in the variations was minimal at best -- based on the effect scale established by Cohen (1988). Additional factorial univariate analyses were employed to determine potential relationships between technology use and student achievement. The data revealed that technology use did not influence the variation of student achievement scale scores as much as race/ethnicity and socioeconomic status. White students outperformed Hispanic students by an average of three scale score points and Black students by an average of six scale score points. Technology use alone averaged less than a one point difference in mean scale scores, and only when interacting with race, gender, and/or SES did the mean difference

  16. Biological effects of heavy ions on small animals in soil and plants

    International Nuclear Information System (INIS)

    We have studied the biological effects of low linear energy transfer (LET) radiation on small animals in soil and plants, which are recognized to play an important role in maintenance of terrestrial ecosystem. However, the effects of high LET radiation must be also considered because many radiation sources in environment could be alpha and beta emitters as well as gamma emitters. As the pilot study, the effect of high LET radiation on Enchytraeus japonensis, a terrestrial earthworm was evaluated with heavy ions at NIRS-HIMAC. The earthworm was exposed to C, Ne, Si, Ar or Fe ion with the energy of 290, 400, 490, 500 and 500 MeV/u, respectively. The earthworm was then reared on plain agar medium in disposable Petri dishes, and the number of worms was enumerated 3 weeks after irradiation. Unfortunately a significant part of HIMAC machine time initially allocated for this study had to be cancelled due to unexpected long-term closing of an experimental facility where the earthworm was reared. Therefore, more than two times of experiments were achieved only in irradiation with Ar ion. The inhibitory effect of Ar ion on the growth of the earthworm was larger than low LET radiation. The relative biological effectiveness (RBE) was approximately 3. (author)

  17. Drug side-effect prediction based on the integration of chemical and biological spaces.

    Science.gov (United States)

    Yamanishi, Yoshihiro; Pauwels, Edouard; Kotera, Masaaki

    2012-12-21

    Drug side-effects, or adverse drug reactions, have become a major public health concern and remain one of the main causes of drug failure and of drug withdrawal once they have reached the market. Therefore, the identification of potential severe side-effects is a challenging issue. In this paper, we develop a new method to predict potential side-effect profiles of drug candidate molecules based on their chemical structures and target protein information on a large scale. We propose several extensions of kernel regression model for multiple responses to deal with heterogeneous data sources. The originality lies in the integration of the chemical space of drug chemical structures and the biological space of drug target proteins in a unified framework. As a result, we demonstrate the usefulness of the proposed method on the simultaneous prediction of 969 side-effects for approved drugs from their chemical substructure and target protein profiles and show that the prediction accuracy consistently improves owing to the proposed regression model and integration of chemical and biological information. We also conduct a comprehensive side-effect prediction for uncharacterized drug molecules stored in DrugBank and confirm interesting predictions using independent information sources. The proposed method is expected to be useful at many stages of the drug development process. PMID:23157436

  18. Leishmania tropica: the effect of darkness and light on biological activities in vitro.

    Science.gov (United States)

    Allahverdiyev, Adil M; Koc, Rabia Cakir; Ates, Sezen Canim; Bagirova, Malahat; Elcicek, Serhat; Oztel, Olga Nehir

    2011-08-01

    Leishmania parasites can be exposed to effects of light in their vectors and hosts, at various periods. However, there is no information about the effects of light on Leishmania parasites. The aim of this study is to investigate the effects of light on various cell parameters of Leishmania tropica, in vitro. All experiments were conducted on L. tropica promastigotes and amastigote-macrophage cultures, using flow cytometric analysis, MTT and phenol-sulfuric acid assay, DAPI and Giemsa. The results showed that the morphology of parasites has changed; the cell cycle has been affected and this caused parasites to remain at G0/G1 phase. Furthermore the proliferation, infectivity, glucose consumption and mitochondrial dehydrogenase activities of parasites were decreased. Thus, for the first time, in this study, the effects of light on biological activities of Leishmania parasites were shown. These new information about parasites' biology, would be very important to investigate the effects of light on the parasites in infected vectors and hosts. PMID:21510933

  19. Heavy-ion radiobiology: new approaches to delineate mechanisms underlying enhanced biological effectiveness.

    Science.gov (United States)

    Blakely, E A; Kronenberg, A

    1998-11-01

    Shortly after the discovery of polonium and radium by Marie Curie and her husband and colleague, Pierre Curie, it was learned that exposure to these alpha-particle emitters produced deleterious biological effects. The mechanisms underlying the increased biological effectiveness of densely ionizing radiations, including alpha particles, neutrons and highly energetic heavy charged particles, remain an active area of investigation. In this paper, we review recent advances in several areas of the radiobiology of these densely ionizing radiations, also known as heavy ions. Advances are described in the areas of DNA damage and repair, chromosome aberrations, mutagenesis, neoplastic transformation in vitro, genomic instability, normal tissue radiobiology and carcinogenesis in vivo. We focus on technical innovations, including novel applications of pulsed-field gel electrophoresis, fluorescence in situ hybridization (FISH), linkage analysis, and studies of gene expression and protein expression. We also highlight the use of new cellular and animal systems, including those with defined DNA repair deficiencies, as well as epithelial cell model systems to assess neoplastic transformation both in vitro and in vivo. The studies reviewed herein have had a substantial impact on our understanding of the genotoxic effects of heavy ions as well as their distinct effects on tissue homeostasis. The use of these radiations in cancer therapy is also discussed. The use of both heavy-ion and proton therapy is on the upswing in several centers around the world, due to their unique energy deposition characteristics that enhance the therapeutic effect and help reduce damage to normal tissue. PMID:9806616

  20. Heavy-ion radiobiology: new approaches to delineate mechanisms underlying enhanced biological effectiveness

    Science.gov (United States)

    Blakely, E. A.; Kronenberg, A.; Chatterjee, A. (Principal Investigator)

    1998-01-01

    Shortly after the discovery of polonium and radium by Marie Curie and her husband and colleague, Pierre Curie, it was learned that exposure to these alpha-particle emitters produced deleterious biological effects. The mechanisms underlying the increased biological effectiveness of densely ionizing radiations, including alpha particles, neutrons and highly energetic heavy charged particles, remain an active area of investigation. In this paper, we review recent advances in several areas of the radiobiology of these densely ionizing radiations, also known as heavy ions. Advances are described in the areas of DNA damage and repair, chromosome aberrations, mutagenesis, neoplastic transformation in vitro, genomic instability, normal tissue radiobiology and carcinogenesis in vivo. We focus on technical innovations, including novel applications of pulsed-field gel electrophoresis, fluorescence in situ hybridization (FISH), linkage analysis, and studies of gene expression and protein expression. We also highlight the use of new cellular and animal systems, including those with defined DNA repair deficiencies, as well as epithelial cell model systems to assess neoplastic transformation both in vitro and in vivo. The studies reviewed herein have had a substantial impact on our understanding of the genotoxic effects of heavy ions as well as their distinct effects on tissue homeostasis. The use of these radiations in cancer therapy is also discussed. The use of both heavy-ion and proton therapy is on the upswing in several centers around the world, due to their unique energy deposition characteristics that enhance the therapeutic effect and help reduce damage to normal tissue.

  1. X-ray imaging and the skin: Radiation biology, patient dosimetry and observed effects

    International Nuclear Information System (INIS)

    A wide variety of radiation-induced deterministic skin effects have been observed after X-ray guided interventions ranging from mild effects, such as transient erythema or temporary epilation, to severe effects, such as desquamation and necrosis. Radiation biologists have identified, in addition to absorbed dose to the skin, other factors that strongly influence the type and severity of a skin reaction, including exposure-related factors (dose rate, fractionation, the size of the exposed area and its site), biological factors (age, oxygen status, capillary density, hormonal status and genetic factors) and ethnic differences. A peak entrance skin dose of 2 Gy is an arbitrary, but pragmatic, threshold for radiation-induced skin effects after X-ray guided interventions. Transient skin injury originating in the epidermis is not expected in the average patient population at peak entrance skin doses up to 6 Gy. Serious skin effects are not likely to occur in clinical practice when optimised X-ray equipment is used in combination with good techniques for fluoroscopy and imaging. However, this might not be true for patients with biological factors that are associated with an increased sensitivity for radiation-induced skin reactions. (authors)

  2. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    International Nuclear Information System (INIS)

    Highlights: ► We analyzed biological effects of N+ implantation on dry Jatropha curcas seed. ► N+ implantation greatly decreased seedling survival rate. ► At doses beyond 15 × 1016 ion cm−2, biological repair took place. ► CAT was essential for H2O2 removal. POD mainly functioned as seed was severely hurt. ► HAsA–GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N+ with energy of 25 keV was applied to treat the dry seed at six different doses. N+ beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 1016 to 15 × 1016 ions cm−2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 1016 ion cm−2, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 1016 ions cm−2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA–GSH cycle appeared to be for regeneration of HAsA.

  3. 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…

  4. Effective automated feature construction and selection for classification of biological sequences.

    Directory of Open Access Journals (Sweden)

    Uday Kamath

    Full Text Available Many open problems in bioinformatics involve elucidating underlying functional signals in biological sequences. DNA sequences, in particular, are characterized by rich architectures in which functional signals are increasingly found to combine local and distal interactions at the nucleotide level. Problems of interest include detection of regulatory regions, splice sites, exons, hypersensitive sites, and more. These problems naturally lend themselves to formulation as classification problems in machine learning. When classification is based on features extracted from the sequences under investigation, success is critically dependent on the chosen set of features.We present an algorithmic framework (EFFECT for automated detection of functional signals in biological sequences. We focus here on classification problems involving DNA sequences which state-of-the-art work in machine learning shows to be challenging and involve complex combinations of local and distal features. EFFECT uses a two-stage process to first construct a set of candidate sequence-based features and then select a most effective subset for the classification task at hand. Both stages make heavy use of evolutionary algorithms to efficiently guide the search towards informative features capable of discriminating between sequences that contain a particular functional signal and those that do not.To demonstrate its generality, EFFECT is applied to three separate problems of importance in DNA research: the recognition of hypersensitive sites, splice sites, and ALU sites. Comparisons with state-of-the-art algorithms show that the framework is both general and powerful. In addition, a detailed analysis of the constructed features shows that they contain valuable biological information about DNA architecture, allowing biologists and other researchers to directly inspect the features and potentially use the insights obtained to assist wet-laboratory studies on retainment or modification

  5. A study of the biological effects of rare earth elements at cellular level using nuclear techniques

    International Nuclear Information System (INIS)

    Objective: To investigate the biological effects and the effecting mechanisms of rare earth elements La, Gd and Ce on cultured rat cells. Methods: The biological effects of La3+ on cultured rat cells and the subcellular distribution of La and Gd and Ce, and the inflow of 45Ca2+ into the cells and total cellular calcium were measured by isotopic tracing, Proton Induced X Ray Emission Analysis (PIXE) and the techniques of biochemistry and cellular biology. Results: La3+ at the concentration of 10-10(or 10-9) - 10-6 mol/L significantly increased quantity of incorporation of 3H-TdR into DNA, total cellular protein and the activity of succinic dehydrogenase of mitochondria. The cell cycle analysis showed that the proportions of cells in S phase were accordingly increased acted by La3+ at above range of concentration. But these values were significantly decreased when concentration of La3+ raised to 10-4 - 10-3 mol/L. It was further discovered that La, Gd and Ce distributed mostly in the nuclei, and then in membranes. Gd and Ce also promoted the inflow of 45Ca2+ into the cells and increased the total calcium content in cells. Conclusions: 1) La3+ at a wide concentration range of 10-10( or 10-9) - 10-6 mol/L promotes proliferation of cultured rat cells, but at even higher concentration (10-4 - 10-3 mol/L) shows cellular toxicity, and there is a striking dose-effect relationship. 2) La, Gd and Ce can enter the cells and mainly distribute in the nuclei. 3) Gd and Ce can promote the inflow of extracellular Ca2+ into the cells and increase total cellular calcium

  6. Effect of host plant on gypsy moth diet and biological efficacy of Btk preparations

    Directory of Open Access Journals (Sweden)

    Milanović Slobodan

    2006-01-01

    Full Text Available The effect of two host plants, Turkey oak (Quercus cerris L and black poplar (Populus nigra L on gypsy moth (Lymantria dispar L development was researched. The effect of host plant was determined based on the parameters which characterize the diet, growth and efficacy of conversion of ingested food of the third instar caterpillars. Along with the effect on development, the effect of host plant on the efficacy of biological preparation based on the bacterium Bacillus thuringiensis var. kurstaki in gypsy moth caterpillar suppression was also researched. The differences in parameters characterizing the diet, growth, and efficacy of ingested food between experimental groups of caterpillars grown on poplar and Turkey oak leaves are explained by the differences in the chemical composition of the leaves of these tree species. The efficacy of Btk preparation is conditioned by the mechanism and content of different groups of defense substances in the leaves of the applied tree species.

  7. Relative Biological Effectiveness of HZE Particles for Chromosomal Exchanges and Other Surrogate Cancer Risk Endpoints.

    Science.gov (United States)

    Cacao, Eliedonna; Hada, Megumi; Saganti, Premkumar B; George, Kerry A; Cucinotta, Francis A

    2016-01-01

    The biological effects of high charge and energy (HZE) particle exposures are of interest in space radiation protection of astronauts and cosmonauts, and estimating secondary cancer risks for patients undergoing Hadron therapy for primary cancers. The large number of particles types and energies that makeup primary or secondary radiation in HZE particle exposures precludes tumor induction studies in animal models for all but a few particle types and energies, thus leading to the use of surrogate endpoints to investigate the details of the radiation quality dependence of relative biological effectiveness (RBE) factors. In this report we make detailed RBE predictions of the charge number and energy dependence of RBE's using a parametric track structure model to represent experimental results for the low dose response for chromosomal exchanges in normal human lymphocyte and fibroblast cells with comparison to published data for neoplastic transformation and gene mutation. RBE's are evaluated against acute doses of γ-rays for doses near 1 Gy. Models that assume linear or non-targeted effects at low dose are considered. Modest values of RBE (10) are predicted at low doses <0.1 Gy. The radiation quality dependence of RBE's against the effects of acute doses γ-rays found for neoplastic transformation and gene mutation studies are similar to those found for simple exchanges if a linear response is assumed at low HZE particle doses. Comparisons of the resulting model parameters to those used in the NASA radiation quality factor function are discussed. PMID:27111667

  8. Relative Biological Effectiveness of HZE Particles for Chromosomal Exchanges and Other Surrogate Cancer Risk Endpoints

    Science.gov (United States)

    Cacao, Eliedonna; Hada, Megumi; Saganti, Premkumar B.; George, Kerry A.; Cucinotta, Francis A.

    2016-01-01

    The biological effects of high charge and energy (HZE) particle exposures are of interest in space radiation protection of astronauts and cosmonauts, and estimating secondary cancer risks for patients undergoing Hadron therapy for primary cancers. The large number of particles types and energies that makeup primary or secondary radiation in HZE particle exposures precludes tumor induction studies in animal models for all but a few particle types and energies, thus leading to the use of surrogate endpoints to investigate the details of the radiation quality dependence of relative biological effectiveness (RBE) factors. In this report we make detailed RBE predictions of the charge number and energy dependence of RBE’s using a parametric track structure model to represent experimental results for the low dose response for chromosomal exchanges in normal human lymphocyte and fibroblast cells with comparison to published data for neoplastic transformation and gene mutation. RBE’s are evaluated against acute doses of γ-rays for doses near 1 Gy. Models that assume linear or non-targeted effects at low dose are considered. Modest values of RBE (10) are predicted at low doses <0.1 Gy. The radiation quality dependence of RBE’s against the effects of acute doses γ-rays found for neoplastic transformation and gene mutation studies are similar to those found for simple exchanges if a linear response is assumed at low HZE particle doses. Comparisons of the resulting model parameters to those used in the NASA radiation quality factor function are discussed. PMID:27111667

  9. Biokinetics of nuclear fuel compounds and biological effects of nonuniform radiation

    International Nuclear Information System (INIS)

    Environmental releases of insoluble nuclear fuel compounds may occur at nuclear power plants during normal operation, after nuclear power plant accidents, and as a consequence of nuclear weapons testing. For example, the Chernobyl fallout contained extensive amounts of pulverized nuclear fuel composed of uranium and its nonvolatile fission products. The effects of these highly radioactive particles, also called hot particles, on humans are not well known due to lack of reliable data on the extent of the exposure. However, the biokinetics and biological effects of nuclear fuel compounds have been investigated in a number of experimental studies using various cellular systems and laboratory animals. In this article, we review the biokinetic properties and effects of insoluble nuclear fuel compounds, with special reference to UO2, PuO2, and nonvolatile, long-lived β-emitters Zr, Nb, Ru, and Ce. First, the data on hot particles, including sources, dosimetry, and human exposure are discussed. Second, the biokinetics of insoluble nuclear fuel compounds in the gastrointestinal tract and respiratory tract are reviewed. Finally, short- and long-term biological effects of nonuniform α- and β-irradiation on the gastrointestinal tract, lungs, and skin are discussed. 191 refs., 1 fig., 3 tabs

  10. Relative Biological Effectiveness of HZE Particles for Chromosomal Exchanges and Other Surrogate Cancer Risk Endpoints.

    Directory of Open Access Journals (Sweden)

    Eliedonna Cacao

    Full Text Available The biological effects of high charge and energy (HZE particle exposures are of interest in space radiation protection of astronauts and cosmonauts, and estimating secondary cancer risks for patients undergoing Hadron therapy for primary cancers. The large number of particles types and energies that makeup primary or secondary radiation in HZE particle exposures precludes tumor induction studies in animal models for all but a few particle types and energies, thus leading to the use of surrogate endpoints to investigate the details of the radiation quality dependence of relative biological effectiveness (RBE factors. In this report we make detailed RBE predictions of the charge number and energy dependence of RBE's using a parametric track structure model to represent experimental results for the low dose response for chromosomal exchanges in normal human lymphocyte and fibroblast cells with comparison to published data for neoplastic transformation and gene mutation. RBE's are evaluated against acute doses of γ-rays for doses near 1 Gy. Models that assume linear or non-targeted effects at low dose are considered. Modest values of RBE (10 are predicted at low doses <0.1 Gy. The radiation quality dependence of RBE's against the effects of acute doses γ-rays found for neoplastic transformation and gene mutation studies are similar to those found for simple exchanges if a linear response is assumed at low HZE particle doses. Comparisons of the resulting model parameters to those used in the NASA radiation quality factor function are discussed.

  11. 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.

  12. Protective Effect of Selected Medicinal Plants against Hydrogen Peroxide Induced Oxidative Damage on Biological Substrates.

    Science.gov (United States)

    Pai Kotebagilu, Namratha; Reddy Palvai, Vanitha; Urooj, Asna

    2014-01-01

    Oxidative stress is developed due to susceptibility of biological substrates to oxidation by generation of free radicals. In degenerative diseases, oxidative stress level can be reduced by antioxidants which neutralize free radicals. Primary objective of this work was to screen four medicinal plants, namely, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, for their antioxidant property using two biological substrates-RBC and microsomes. The antioxidative ability of three solvent extracts, methanol (100% and 80%) and aqueous leaf extracts, was studied at different concentrations by thiobarbituric acid reactive substances method using Fenton's reagent to induce oxidation in the substrates. The polyphenol and flavonoid content were analyzed to relate with the observed antioxidant effect of the extracts. The phytochemical screening indicated the presence of flavonoids, polyphenols, tannins, and β-carotene in the samples. In microsomes, 80% methanol extract of Canthium and Costus and, in RBC, 80% methanol extract of Costus showed highest inhibition of oxidation and correlated well with the polyphenol and flavonoid content. From the results it can be concluded that antioxidants from medicinal plants are capable of inhibiting oxidation in biological systems, suggesting scope for their use as nutraceuticals. PMID:25436152

  13. Protective Effect of Selected Medicinal Plants against Hydrogen Peroxide Induced Oxidative Damage on Biological Substrates

    Directory of Open Access Journals (Sweden)

    Namratha Pai Kotebagilu

    2014-01-01

    Full Text Available Oxidative stress is developed due to susceptibility of biological substrates to oxidation by generation of free radicals. In degenerative diseases, oxidative stress level can be reduced by antioxidants which neutralize free radicals. Primary objective of this work was to screen four medicinal plants, namely, Andrographis paniculata, Costus speciosus, Canthium parviflorum, and Abrus precatorius, for their antioxidant property using two biological substrates—RBC and microsomes. The antioxidative ability of three solvent extracts, methanol (100% and 80% and aqueous leaf extracts, was studied at different concentrations by thiobarbituric acid reactive substances method using Fenton’s reagent to induce oxidation in the substrates. The polyphenol and flavonoid content were analyzed to relate with the observed antioxidant effect of the extracts. The phytochemical screening indicated the presence of flavonoids, polyphenols, tannins, and β-carotene in the samples. In microsomes, 80% methanol extract of Canthium and Costus and, in RBC, 80% methanol extract of Costus showed highest inhibition of oxidation and correlated well with the polyphenol and flavonoid content. From the results it can be concluded that antioxidants from medicinal plants are capable of inhibiting oxidation in biological systems, suggesting scope for their use as nutraceuticals.

  14. Biological Effects of Naturally Occurring Sphingolipids, Uncommon Variants, and Their Analogs.

    Science.gov (United States)

    Lai, Mitchell K P; Chew, Wee Siong; Torta, Federico; Rao, Angad; Harris, Greg L; Chun, Jerold; Herr, Deron R

    2016-09-01

    Sphingolipids (SPs) comprise a highly diverse class of lipids that serve biological roles both as structural components of cell membranes and as mediators of cell signaling. Pharmacologic and genetic manipulation of SPs and their signaling systems have underscored their importance in most biological processes, including central nervous system development and function. Likewise, perturbations of SP accumulation or signaling have been associated with a number of disease states, such as neural tube defects, neuroinflammation, stroke, and dementia. SPs can be endogenously synthesized de novo, and their metabolism is a well-regulated process, so their value as nutraceuticals has not been scrutinized. However, there is evidence that sphingolipid-rich diets can affect lipid homeostasis, and several mycotoxins are SP analogs that are known to cause profound derangement of SP metabolism or signaling. Furthermore, plants and invertebrates have SP species that are not present in mammals. Several of these have been shown to induce biological responses in mammalian cells. These findings suggest that dietary intake of SPs or SP analogs may have significant effects on human health or disease outcome. This manuscript provides an overview of SP metabolism and signaling, their perturbations in neurological diseases, as well as potential impacts of modulating this system in the brain. PMID:27393119

  15. Effects of gentle remediation technologies on soil biological and biochemical activities - a review.

    Science.gov (United States)

    Marschner, B.; Haag, R.; Renella, G.

    2009-04-01

    Remediation technologies for contaminated sites are generally designed to reduce risks for human health, groundwater or plant quality. While some drastic remediation measures such as soil excavation, thermal treatment or soil washing eliminate or strongly reduce soil life, in-situ treatments involving plants or immobilizing additives may also restore soil functionality by establishing or promoting a well structured and active community of soil organisms. Biological parameters that are sensitive to contaminants and other pedo-environmental conditions and which contribute to biogeochemical nutrient cycles, can be used as synthetic indicators of the progress and also the efficiency of given remediation approaches. Data from long-term studies on re-vegetated mine spoils show that biological and biochemical activity is enhanced with increasing plant density and diversity. Among the soil amendments, most measures that introduce organic matter or alkalinity to the contaminated soils also improve microbial or faunal parameters. Only few amendments, such as phosphates and chelators have deleterious effects on soil biota. In this review, soil microbial biomass and the activity of the enzymes phosphatase and arylsulphatase are identified as suitable and sensitive biological indicators for soil health. The results and future research needs are are summarized.

  16. Effects of timber harvest on river food webs: physical, chemical and biological responses.

    Directory of Open Access Journals (Sweden)

    J Timothy Wootton

    Full Text Available I compared physical, chemical and biological characteristics of nine rivers running through three timber harvest regimes to investigate the effects of land use on river ecosystems, to determine whether these corresponded to changes linked with downstream location, and to compare the response of different types of indicator variables. Physical variables changed with downstream location, but varied little with timber harvest. Most chemical variables increased strongly with timber harvest, but not with downstream location. Most biological variables did not vary systematically with either timber harvest or downstream location. Dissolved organic carbon did not vary with timber harvest or downstream location, but correlated positively with salmonid abundance. Nutrient manipulations revealed no general pattern of nutrient limitation with timber harvest or downstream location. The results suggest that chemical variables most reliably indicate timber harvest impact in these systems. The biological variables most relevant to human stakeholders were surprisingly insensitive to timber harvest, however, apparently because of decoupling from nutrient responses and unexpectedly weak responses by physical variables.

  17. Early biological effects of low doses of ionizing radiation on yeast cells

    International Nuclear Information System (INIS)

    The biological effectiveness of different radiation types for variety organisms requires further study. For fundamental studies of this problem it is worthwhile to use the most thoroughly investigated biological objects, for example, yeasts. The yeast Saccharomyces cerevisiae was used as the test eukaryotic organism which gives the experimenter complete control over its chemical and physical environment. The aim of the study consisted in comparative analysis of early effects induced by low doses of low LET (60Co and 137Cs) and high LET ( α-particles 239Pu, neutrons) radiation on eukaryotic cells (cell survival about 100%). Biological effects of low doses of ionizing radiation were studied by two criteria: 1.delay of cell division and kinetics of yeast cells micro-colonies formation; 2.morphology of micro-colonies at different temperature. The results have shown that only small part of irradiated cell population (∼10%) divided at the same rate as unirradiated cells. Other part of cells had a delayed division. Unirradiated control cells formed typical micro-colonies at the solid nutrient media (YEPD) after 10 15 h of incubation. The fraction of cells population (20- 25%) exposed to low doses of?-particles or neutrons formed spectrum of untypical micro-colonies for the same incubation time, which consisted of small number of larger and more elongated cells. Some of these micro-colonies had 10 50 cells were of exotic forms ('spider'), differed from other micro-colonies in population. Using this method we can reveal an early response of cells at very low doses (survival about 100%) and determine the number non-lethally damaged cells. (author)

  18. Physico-chemical properties and biological effects of diesel and biomass particles.

    Science.gov (United States)

    Longhin, Eleonora; Gualtieri, Maurizio; Capasso, Laura; Bengalli, Rossella; Mollerup, Steen; Holme, Jørn A; Øvrevik, Johan; Casadei, Simone; Di Benedetto, Cristiano; Parenti, Paolo; Camatini, Marina

    2016-08-01

    Diesel combustion and solid biomass burning are the major sources of ultrafine particles (UFP) in urbanized areas. Cardiovascular and pulmonary diseases, including lung cancer, are possible outcomes of combustion particles exposure, but differences in particles properties seem to influence their biological effects. Here the physico-chemical properties and biological effects of diesel and biomass particles, produced under controlled laboratory conditions, have been characterized. Diesel UFP were sampled from a Euro 4 light duty vehicle without DPF fuelled by commercial diesel and run over a chassis dyno. Biomass UFP were collected from a modern automatic 25 kW boiler propelled by prime quality spruce pellet. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of both diesel and biomass samples showed aggregates of soot particles, but in biomass samples ash particles were also present. Chemical characterization showed that metals and PAHs total content was higher in diesel samples compared to biomass ones. Human bronchial epithelial (HBEC3) cells were exposed to particles for up to 2 weeks. Changes in the expression of genes involved in xenobiotic metabolism were observed after exposure to both UFP already after 24 h. However, only diesel particles modulated the expression of genes involved in inflammation, oxidative stress and epithelial-to-mesenchymal transition (EMT), increased the release of inflammatory mediators and caused phenotypical alterations, mostly after two weeks of exposure. These results show that diesel UFP affected cellular processes involved in lung and cardiovascular diseases and cancer. Biomass particles exerted low biological activity compared to diesel UFP. This evidence emphasizes that the study of different emission sources contribution to ambient PM toxicity may have a fundamental role in the development of more effective strategies for air quality improvement. PMID:27194366

  19. Biological modelling of the radiation dose escalation effect of regional hyperthermia in cervical cancer

    International Nuclear Information System (INIS)

    Locoregional hyperthermia combined with radiotherapy significantly improves locoregional control and overall survival for cervical tumors compared to radiotherapy alone. In this study biological modelling is applied to quantify the effect of radiosensitization for three cervical cancer patients to evaluate the improvement in equivalent dose for the combination treatment with radiotherapy and hyperthermia. The Linear-Quadratic (LQ) model extended with temperature-dependent LQ-parameters α and β was used to model radiosensitization by hyperthermia and to calculate the conventional radiation dose that is equivalent in biological effect to the combined radiotherapy and hyperthermia treatment. External beam radiotherapy planning was performed based on a prescription dose of 46Gy in 23 fractions of 2Gy. Hyperthermia treatment using the AMC-4 system was simulated based on the actual optimized system settings used during treatment. The simulated hyperthermia treatments for the 3 patients yielded a T50 of 40.1 °C, 40.5 °C, 41.1 °C and a T90 of 39.2 °C, 39.7 °C, 40.4 °C, respectively. The combined radiotherapy and hyperthermia treatment resulted in a D95 of 52.5Gy, 55.5Gy, 56.9Gy in the GTV, a dose escalation of 7.3–11.9Gy compared to radiotherapy alone (D95 = 45.0–45.5Gy). This study applied biological modelling to evaluate radiosensitization by hyperthermia as a radiation-dose escalation for cervical cancer patients. This model is very useful to compare the effectiveness of different treatment schedules for combined radiotherapy and hyperthermia treatments and to guide the design of clinical studies on dose escalation using hyperthermia in a multi-modality setting

  20. Effects of Solid Retention Time (SRT) on Sludge Characteristics in Enhanced Biological Phosphorus Removal (EBPR) Reactor

    OpenAIRE

    Li, N.; X Wang; N Ren; Zhang, K.; Kang, H; You, S.

    2008-01-01

    This study investigated the effects of solid retention time (SRT) on sludge characteristics and operational performance in enhanced biological phosphorus removal (EBPR) reactor. The results showed that the reactor operated at SRT of τ = 8.3 d could achieve phosphate removal efficiency η > 90 % and SVI < 100 mL g–1. In comparison, increasing SRT to τ = 16.6 d led to a decrease of phosphate removal (η < 85 %) and an increase of SVI value (160 mL g–1), implying a performance degradation and wors...

  1. Relative biological effectiveness for protons of energies up to 31 MeV

    International Nuclear Information System (INIS)

    The relative biological effectiveness (RBE) was determined for proton beams of 31,12, and 8 MeV produced at the Milano University Cyclotron. Survival curves for human cells grown in monolayer at different proton energies and for γ rays from 60Co were determined. The minimum clone size to be chosen for definition of true survivors was examined. RBE values of 1.0 +- 0.1, 1.4 +- 0.2, and 1.5 +- 0.2, respectively, were found and compared with the results of other experiments in this energy range

  2. Indium arsenide nanowire field-effect transistors for pH and biological sensing

    International Nuclear Information System (INIS)

    Indium Arsenide is a high mobility semiconductor with a surface electron accumulation layer that allows ohmic electrical contact to metals. Here, we present nanowire devices based on this material as a platform for chemical and biological sensing. The sensing principle involves the binding of a charged species at the sensor surface transduced via field effect into a change in current flowing through the sensor. We show the sensitivity of the platform to the H+ ion concentration in solution as proof of principle and demonstrate the sensitivity to larger charged protein species. The sensors are highly reproducible and reach a detection limit of 10 pM for Avidin.

  3. Multiwalled carbon nanotubes for dielectric sensing of biological systems: An effective treatment of polarization

    Science.gov (United States)

    Picaud, F.; Girardet, C.

    We determine the efficiency of semi-conducting multiwalled carbon nanotubes in resonator configuration acting as sensors of biological systems. The resonance frequency shifts due to the dielectric changes of the resonator upon adsorption of highly idealized micelles schematized by a set of concentric shells of polarizable centers surrounded by a water shell to mimic the solvent are calculated on the basis of an effective polarizability distribution in the tube and the sensed system. Cylindrical and spherical geometries including different sizes are considered for the micelles to show that size and geometry selectivity could be reached with such an approach.

  4. Effects of heat on the biological activity of wild Cordyceps sinensis

    OpenAIRE

    Pengkai Wu; Zhi Tao; Huafeng Liu; Guixiang Jiang; Changhua Ma; Chunmei Wang; Di Geng

    2015-01-01

    Background: Current methods of extending the storage time of wild Cordyceps sinensis adversely affect the nutritive and medicinal value of the product. Thus, this study was designed to investigate the effects of heat treatment, a relatively safe storage extension method, on the biological activity of wild C. sinensis. Methods: Samples were heated to 60, 80, or 100°C for 15, 30, or 60 minutes. SOD activity in wild C. sinensis before and after heating was assayed using a standard colorimetri...

  5. Progress of transcription factor Twist expression in breast cancer and its biological effect

    Institute of Scientific and Technical Information of China (English)

    Tian Qian

    2016-01-01

    Breast cancer is the most common malignant tumor in women and the pathogenesis is not fully elucidated. Proliferation, invasion, epithelial-mesenchymal transition and angiogenesis are the links closely related to the occurrence and development of breast cancer. Twist is a type of basic helix-loop-helix transcription factor that can affect cell proliferation and invasion process, epithelial-mesenchymal transition process and angiogenesis process through regulating the transcription of downstream target genes. In the research, the study of transcription factor Twist expression in breast cancer and its biological effect is reviewed.

  6. Exergames: neuroplastic hypothesis about cognitive improvement and biological effects on physical function of institutionalized older persons

    Science.gov (United States)

    Monteiro-Junior, Renato Sobral; Vaghetti, César Augusto Otero; Nascimento, Osvaldo José M.; Laks, Jerson; Deslandes, Andrea Camaz

    2016-01-01

    Exergames can be considered a dual task because the games are performed by a man-videogame interface, requiring cognitive and motor functions simultaneously. Although the literature has shown improvements of cognitive and physical functions due to exergames, the intrinsic mechanisms involved in these functional changes have still not been elucidated. The aims of the present study were (1) to demonstrate the known biological mechanisms of physical exercise regarding muscle adaptation and establish a relationship with exergames; and (2) to present a neurobiological hypothesis about the neuroplastic effects of exergames on the cognitive function of institutionalized older persons. These hypotheses are discussed. PMID:27073355

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

    International Nuclear Information System (INIS)

    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. [Experimental studies on possible biological effects of ultrasonic diagnosis: ultrastructural analysis of rat embryo].

    Science.gov (United States)

    Cardinale, A; Lagalla, R; De Maria, M; Valentino, B; Laconi, A

    1985-01-01

    Within the limits of a systematic research on the biological effects of the ultrasounds, the authors refer on their personal experience on rat's embrions treated, for 120 seconds, with a ultrasonic beam having the common characteristics used in diagnostic investigations. The ultra-structural studies on the hepatic parenchyma substantially confirm the previous results obtained in the adult cavy, exposed for the same period of time, i.e. a diffuse cytoplasmic vacuolization and an unstable mitochondrial damage. Various suggestions are advanced on the particular sensibility that the mitocondria show because of the ultrasonic action. The authors explain the limits of their experimentation in this specific sector of the scientific research. PMID:3909243

  9. Relative biological effectiveness of neutrons and conventional values of quality factors

    International Nuclear Information System (INIS)

    The radiation hygiene system of irradiation control among other hypotheses and conventions also uses the agreed values of the factors of radiation quality, accepted mainly on the basis of extrapolation and generalization of comparative experiments and irradiation of small experimental animals and cell cultures. There are practically no data on the relative biological effectiveness of the irradiation of man with small doses. The justification is discussed of the extrapolation of RBE of neutrons determined at higher doses and small non-uniformities of irradiation. Also discussed are the frequently appearing views of the necessity of reviewing the recommended values of quality factors. (author)

  10. The Effect of Fasting Pattern on Biological Performance of Quail at Early Production Period

    OpenAIRE

    Efka Tugiyanti

    2005-01-01

    The objective of this research was to find out the effect of fasting pattern on biological performance of quail at early production period. 50 kg commercial feed, vitamins and medicine were applied on 140 heads of seven old day quail. Four different fasting pattern were employed as treatment, i.e. ad libitum diet (Po); every two days fasting (P1); every three days fasting (P2); every four days fasting (P3); and every five days fasting (P4). Ad libitum amount of corn and water were offered...

  11. 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)

  12. Adverse effect of agroecosystem pond water on biological endpoints of common toad (Rhinella arenarum) tadpoles.

    Science.gov (United States)

    Babini, María Selene; Bionda, Clarisa de Lourdes; Salas, Nancy Edith; Martino, Adolfo Ludovico

    2016-08-01

    Chemical prroducts used in farming and wastes from livestock can contaminate pond water in agroecosystems due to runoff. Amphibians using these ponds for breeding are probably exposed to pollutants, and serious consequences might be observed afterward at the population level. Assessment biological endpoints of anuran to water quality give a realistic estimate of the probability of occurrence of adverse effects and provide an early warning signal. In this study, the ecotoxicity of agroecosystem ponds from the south of Córdoba province, Argentina, was investigated. Ponds in four sites with different degrees of human disturbance were selected: three agroecosystems (A1, A2, A3) and a site without crops or livestock (SM). The effect of pond water quality on the biological endpoint of Rhinella arenarum tadpoles was examined using microcosms with pond water from sites. Biological endpoints assessed were as follows: mortality, growth, development, morphological abnormalities (in body shape, gut, and labial tooth row formula), behavior, and blood cell parameters (micronucleus and nuclear abnormalities). Results indicated that water from agroecosystems has adverse effect on early life stage of R. arenarum. High mortality and fewer metamorphs were recorded in the A1 and A3 treatments. Tadpoles and metamorphs from A1 and A2 treatments had lower body condition. Tadpoles from A1 and A3 showed the highest prevalence of morphological abnormalities. The lowest amount of tadpoles feeding and the highest percentage of tadpoles swimming on the surface were observed in treatments with agroecosystem pond water. The higher frequencies of micronuclei and nuclear abnormalities were recorded in tadpoles from A1, A2, and A3 treatments. We check the sensitivity of the biological endpoints of R. arenarum tadpoles like early warning indicators of water quality. We found that the poor water quality of agroecosystem ponds has impact on the health of the tadpoles, and this could affect the

  13. Exergames: neuroplastic hypothesis about cognitive improvement and biological effects on physical function of institutionalized older persons.

    Science.gov (United States)

    Monteiro-Junior, Renato Sobral; Vaghetti, César Augusto Otero; Nascimento, Osvaldo José M; Laks, Jerson; Deslandes, Andrea Camaz

    2016-02-01

    Exergames can be considered a dual task because the games are performed by a man-videogame interface, requiring cognitive and motor functions simultaneously. Although the literature has shown improvements of cognitive and physical functions due to exergames, the intrinsic mechanisms involved in these functional changes have still not been elucidated. The aims of the present study were (1) to demonstrate the known biological mechanisms of physical exercise regarding muscle adaptation and establish a relationship with exergames; and (2) to present a neurobiological hypothesis about the neuroplastic effects of exergames on the cognitive function of institutionalized older persons. These hypotheses are discussed. PMID:27073355

  14. Relative biological effectiveness (RBE) of fission neutrons and gamma rays at occupational exposure levels

    International Nuclear Information System (INIS)

    The pathologic consequences of exposure to 60 equal once-weekly doses of fission neutron or 60Co gamma rays have been subjected to dose-response analyses for the purposes of generating relative biological effectiveness (RBE) values for the major causes of death of for tumor occurrences. Cumulative probabilities of death or occurrence were generated for 15 categories of neoplastic disease for the time interval of 800--999 days since first exposure. These probabilities were developed for each dose, sex, and radiation quality, and a dose-response analysis was applied to derive linear risk coefficients of death or occurrence. 40 refs., 16 figs., 9 tabs

  15. Effects of fumonisin B1 on selected biological responses and performance of broiler chickens

    Directory of Open Access Journals (Sweden)

    Ricardo H. Rauber

    2013-09-01

    Full Text Available The objective of this study was to determine the effects of three doses of fumonisin B1 (0, 100, and 200mg/kg of feed on biological variables (relative weight of liver [RWL], total plasma protein [TPP], albumin [Alb], calcium [Ca], phosphorus [P], uric acid [UA], alanine aminotransferase [ALT], aspartate aminotransferase [AST], gamma glutamyltransferase [GGT], alkaline phosphatase [AP], total cholesterol [Chol], triglycerides [Tri], sphinganine-to-sphingosine ratio [SA:SO], and C-reactive protein [CRP], morphological evaluation of the small intestine (villus height [VH], crypt depth [CD], and villus-to-crypt ratio [V:C], histological evaluation, and on performance (body weight [BW], feed intake [FI], and feed conversion rate [FCR] of broiler chickens. Significant effects of FB were observed on BW and FI (reduced, on RWL, TPP, Ca, ALT, AST, GGT, Chol, and Tri (increased at both 14 and 28 days evaluations. In addition, significant increase was observed on FCR, Alb, P, SA:SO, and CRP and significant reduction in UA, VH, and V:C only at the 28 days evaluation. Significant histological lesions were observed on liver and kidney of FB inoculated broilers at 14 and 28 days. Those results show that FB has a significant effect on biological and histological variables and on performance of broiler chickens.

  16. Is anaerobic digestion effective for the removal of organic micropollutants and biological activities from sewage sludge?

    Science.gov (United States)

    Gonzalez-Gil, L; Papa, M; Feretti, D; Ceretti, E; Mazzoleni, G; Steimberg, N; Pedrazzani, R; Bertanza, G; Lema, J M; Carballa, M

    2016-10-01

    The occurrence of emerging organic micropollutants (OMPs) in sewage sludge has been widely reported; nevertheless, their fate during sludge treatment remains unclear. The objective of this work was to study the fate of OMPs during mesophilic and thermophilic anaerobic digestion (AD), the most common processes used for sludge stabilization, by using raw sewage sludge without spiking OMPs. Moreover, the results of analytical chemistry were complemented with biological assays in order to verify the possible adverse effects (estrogenic and genotoxic) on the environment and human health in view of an agricultural (re)use of digested sludge. Musk fragrances (AHTN, HHCB), ibuprofen (IBP) and triclosan (TCS) were the most abundant compounds detected in sewage sludge. In general, the efficiency of the AD process was not dependent on operational parameters but compound-specific: some OMPs were highly biotransformed (e.g. sulfamethoxazole and naproxen), while others were only slightly affected (e.g. IBP and TCS) or even unaltered (e.g. AHTN and HHCB). The MCF-7 assay evidenced that estrogenicity removal was driven by temperature. The Ames test did not show point mutation in Salmonella typhimurium while the Comet test exhibited a genotoxic effect on human leukocytes attenuated by AD. This study highlights the importance of combining chemical analysis and biological activities in order to establish appropriate operational strategies for a safer disposal of sewage sludge. Actually, it was demonstrated that temperature has an insignificant effect on the disappearance of the parent compounds while it is crucial to decrease estrogenicity. PMID:27344252

  17. The Effectiveness of an Online Curriculum on High School Students' Understanding of Biological Evolution

    Science.gov (United States)

    Marsteller, Robert B.; Bodzin, Alec M.

    2015-01-01

    An online curriculum about biological evolution was designed to promote increased student content knowledge and evidentiary reasoning. A feasibility study was conducted with 77 rural high school biology students who learned with the online biological evolution unit. Data sources included the Biological Evolution Assessment Measure (BEAM), an…

  18. Environmental parameters of the Tennessee River in Alabama. 2: Physical, chemical, and biological parameters. [biological and chemical effects of thermal pollution from nuclear power plants on water quality

    Science.gov (United States)

    Rosing, L. M.

    1976-01-01

    Physical, chemical and biological water quality data from five sites in the Tennessee River, two in Guntersville Reservoir and three in Wheeler Reservoir were correlated with climatological data for three annual cycles. Two of the annual cycles are for the years prior to the Browns Ferry Nuclear Power Plant operations and one is for the first 14 months of Plant operations. A comparison of the results of the annual cycles indicates that two distinct physical conditions in the reservoirs occur, one during the warm months when the reservoirs are at capacity and one during the colder winter months when the reservoirs have been drawn-down for water storage during the rainy months and for weed control. The wide variations of physical and chemical parameters to which the biological organisms are subjected on an annual basis control the biological organisms and their population levels. A comparison of the parameters of the site below the Power plant indicates that the heated effluent from the plant operating with two of the three reactors has not had any effect on the organisms at this site. Recommendations given include the development of prediction mathematical models (statistical analysis) for the physical and chemical parameters under specific climatological conditions which affect biological organisms. Tabulated data of chemical analysis of water and organism populations studied is given.

  19. 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.

  20. New derivation method and simulation of skin effect in biological tissue.

    Science.gov (United States)

    Fan, Xiaoli; Zhou, Qianxiang; Liu, Zhongqi; Xie, Fang

    2015-01-01

    Based on the electrical properties of biological tissues, bioimpedance measurement technology can be employed to collect physiologic and pathologic information by measuring changes in human bioimpedance. When an alternating current (AC) is applied as a detection signal to a tissue, the current field distribution, which is affected by skin effect, is related to both the bioimpedance of the tissue and the AC frequency. These relations would possibly reduce the accuracy and reliability of the measurement. In this study, an electromagnetic theory-based method, in which cylindrical conductor were divided into layers, was used to obtain current field distribution models of human limbs. Model simulations were conducted in MATLAB. The skin effect phenomenon and its characteristics in human tissues at different frequencies were observed, thus providing essential data on skin effect, which are useful in the development of bioimpedance measurement technology. PMID:26406033

  1. Status of research on biological effects and safety of electromagnetic radiation: telecommunications frequencies

    International Nuclear Information System (INIS)

    The possible adverse effects on human health of exposure to radiofrequency (RF) and microwave electromagnetic fields and radiation are of public concern. As the ambient electromagnetic environment continues to intensify (e.g. cellular and portable phones, wireless communications, LANs, PCNs) the effects of exposure from cumulative sources and prolonged exposure to low levels needs to be addressed. This review considers RF and microwave radiation above 100 kHz. It is acknowledged that there are several possible areas of biological interaction which have health implications and about which current knowledge is limited. Advice is based on the assessment of risks to health resulting from these exposures as derived from studies on the effects of RF radiation on animals and volunteers and from epidemiological studies of exposed populations. 360 refs., 9 tabs., 1 fig

  2. Biological effects of 224Ra. Benefit and risk of therapeutic application

    International Nuclear Information System (INIS)

    The Second Symposium on the Biological effects of 224Ra, held at Neuherberg, was focused on two topical aspects of radiation protection. One aspect was the long-term effects of high-LET ionizing radiations on man and the quantitative data involved in risk assessment at low doses. The evaluation of epidemiological studies and experimental research was discussed in order to provide facts and figures contributing to an objective assessment of the radiation hazard from incorporated radionuclides. The other aspect was that of radiation protection in medicine. In the case of 224Ra treatment of ankylosing spondylitis the questions of benefit and risk of this therapeutic use of ionizing radiations were discussed, the aim being to achieve the therapeutic effect while reducing radiation exposure - and therefore the hazard - to a minimum. The proceedings contain the complete texts of 23 papers as well as the final round table discussions

  3. Biological effects of cesium-137 injected in beagle dogs of different ages

    Energy Technology Data Exchange (ETDEWEB)

    Nikula, K.J.; Muggenburg, B.A.; Griffith, W.C. [and others

    1995-12-01

    The toxicity of cesium-137 ({sup 137}Cs) in the Beagle dog was investigated at the Argonne National Laboratory (ANL) as part of a program to evaluate the biological effects of internally deposited radionuclides. The toxicity and health effects of {sup 137}Cs are important to understand because {sup 137}Cs is produced in large amounts in light-water nuclear reactors. Large quantities of cesium radioisotopes have entered the human food chain as a result of atmospheric nuclear weapons test, and additional cesium radioisotopes were released during the Chernobyl accident. Although the final analyses are not complete, three findings are significant: older dogs dies significantly earlier than juvenile and young adult dogs; greater occurrence of sarcomas in the cesium-137 injected dogs; the major nonneoplastic effect in dogs surviving beyond 52 d appears to be testicular atrophy.

  4. Effect of fast electrons on the reproductive biology of the grain mite Acarus siro (Acari: Acaridae)

    International Nuclear Information System (INIS)

    The effect of fast electrons on the reproductive biology of the grain mite Acarus siro was investigated in the laboratory at 25±1°C and 85% RH. Irradiation of adults with substerilizing doses of fast electrons significantly reduced fecundity and egg viability of the mite. The number of spermatophores found in the bursa of treated females was also considerably reduced. However, no change in the shape of the spermatophores was observed. It was not known whether the decrease in fecundity and egg viability was the result of the drop in spermatophore production or to the death of sperm cells. Fast electrons had less effect upon fecundity than the same dose of gamma radiation. However, irradiation by fast electrons had a similar effect on egg viability (expressed in percentage), number of spermatophores produced per individual, and number of adult F1 progeny. Fast-electron doses above 0.4 kGy caused sterility of the mite

  5. Carbon Heavy-ion Radiation Induced Biological effects on Oryza sativa L.

    Science.gov (United States)

    Zhang, Meng; Sun, Yeqing; Li, Xishan; Gong, Ning; Meng, Qingmei; Liu, Jiawei; Wang, Ting

    2016-07-01

    Large number of researches on rice after spaceflights indicated that rice was a favorable model organism to study biological effects induced by space radiation. The stimulative effect could often be found on rice seedlings after irradiation by low-dose energetic heavy-ion radiation. Spaceflight also could induce stimulative effect on kinds of seeds. To further understand the mechanism of low-dose radiation biological effects and the dose range, the germinated rice seeds which were irradiated by different doses of carbon heavy-ion (0, 0.02, 0.1, 0.2, 1, 2, 5, 10, 15 and 20Gy, LET=27.3keV/µm) were used as materials to study. By investigating the variation of rice phenotype under different doses, we found that 2Gy radiation dose was a dividing point of the phenotypic variation. Transmission electron microscopy was used to observe the variation of mitochondria, chloroplast, endoplasmic reticulum, ribosome and nucleus in mesophyll cell of rice apical meristem at 24 hours after radiation with different doses. The cells were not apparently physiologically damaged when the dose of radiation was less than 2Gy. The number of chloroplast did not change significantly, but the number of mitochondria was significantly increased, and gathered around in the chloroplast and endoplasmic reticulum; the obvious lesion of chloroplast and mitochondria were found at the mesophyll cells when radiation dose was higher than 2Gy. The mitochondria were swelling and appearing blurred crest. The chloroplast and mitochondrial mutation rate increased significantly (pplant. Keywords: Heavy-ion radiation; Low dose; Stimulation effect; Inhibition effect; Rice.

  6. The conflict between the biological effects of ultrasoft X-rays and microdosimetric measurements and application

    International Nuclear Information System (INIS)

    Approximate calculated microdosimetric spectra for these ultrasoft X-rays and other radiations will be presented. These will be compared with their observed biological effectiveness in cultured mammalian cells (inactivation and mutation to thioguanine resistance). The ultrasoft X-rays are found to be considerably more effective than 60Co γ-rays. These observed results are contrary to the usual predictions of microdosimetry which are based on the fact that the average event size (and zeta) of γ-rays is similar to that of aluminium X-rays and much greater than that of carbon X-rays. A well defined 'LET' cannot be assigned to the short tracks of such slow electrons but it is clear that they are at least as effective as long tracks ('track intersections') of helium ions of 'comparable' LET. This implies that the sites of damage are <=0.007μm and that radiation events of only about 14 ionizations (0.28 keV) are highly effective in producing biological effects. Since most types of radiation produce slow electrons and other short tracks (e.g. secondary electrons in γ-ray irradiations, delta-rays in heavy ion and neutron irradiations and very short recoils in neutron irradiation), the effectiveness of damage on this small scale has major implications for models of radiation action and for the relevance of those microdosimetric measurements which are based on total ionization in large simulated spheres of approximately 1μm. Some of these implications will be discussed and alternative approaches considered

  7. The effects of an interdisciplinary undergraduate human biology program on socioscientific reasoning, content learning, and understanding of inquiry

    Science.gov (United States)

    Eastwood, Jennifer L.

    Preparing students to take informed positions on complex problems through critical evaluation is a primary goal of university education. Socioscientific issues (SSI) have been established as effective contexts for students to develop this competency, as well as reasoning skills and content knowledge. This mixed-methods study investigates the effects of an interdisciplinary undergraduate human biology program focused on the development of evidence-based reasoning to form personal commitments on SSI. Specifically, the study investigates how human biology majors differ from traditional biology majors in their reasoning with SSI, their perceptions of experiences with SSI, their understanding of scientific inquiry, their levels and perceptions of science content knowledge, and their general program perceptions. These outcomes were assessed through open-ended questionnaires on SSI and scientific inquiry and a basic biology concept test administered to 95 participants representing both programs and 16 semi-structured student interviews. Although the two groups did not differ significantly in their decisions or factors influencing their decisions in SSI, human biology majors showed higher levels of socioscientific reasoning, suggesting that learning contextualized in SSI helped them understand and reason with similar issues. While biology majors reported few experiences with socioscientific reasoning, human biology majors felt well equipped to reason with SSI and more likely to consider alternative perspectives in their decision making. Human biology majors also were more likely to view social science research as a form of inquiry and less likely to view scientific inquiry as purely experimental. No difference was found between groups in basic biology content knowledge, although human biology majors felt they were exposed to less detailed biology content. This exploratory study illustrates a novel approach to interdisciplinary, SSI-based science education at the college

  8. Some biological side effects in laboratories of the plasma physics and nuclear fusion research school of Iran

    OpenAIRE

    Shervin Goudarzi; Mina Jafarabadi; Fatemeh Nejad

    2010-01-01

    Objective: Reporting some biological side effects with special attention to reproductive points which were seen after different experiments in laboratories of the Plasma Physics & Nuclear Fusion in atomic energy organization of Iran.Materials and methods: Dosimeter analysis and interpretation of biological side effects of research studies in nuclear fusion laboratories.Results: In the last 3 decades, neglecting the principles of the radiation protection has been confirmed in laboratories ...

  9. The effect of oxytocin on biological motion perception in dogs (Canis familiaris).

    Science.gov (United States)

    Kovács, Krisztina; Kis, Anna; Kanizsár, Orsolya; Hernádi, Anna; Gácsi, Márta; Topál, József

    2016-05-01

    Recent studies have shown that the neuropeptide oxytocin is involved in the regulation of several complex human social behaviours. There is, however, little research on the effect of oxytocin on basic mechanisms underlying human sociality, such as the perception of biological motion. In the present study, we investigated the effect of oxytocin on biological motion perception in dogs (Canis familiaris), a species adapted to the human social environment and thus widely used to model many aspects of human social behaviour. In a within-subjects design, dogs (N = 39), after having received either oxytocin or placebo treatment, were presented with 2D projection of a moving point-light human figure and the inverted and scrambled version of the same movie. Heart rate (HR) and heart rate variability (HRV) were measured as physiological responses, and behavioural response was evaluated by observing dogs' looking time. Subjects were also rated on the personality traits of Neuroticism and Agreeableness by their owners. As expected, placebo-pretreated (control) dogs showed a spontaneous preference for the biological motion pattern; however, there was no such preference after oxytocin pretreatment. Furthermore, following the oxytocin pretreatment female subjects looked more at the moving point-light figure than males. The individual variations along the dimensions of Agreeableness and Neuroticism also modulated dogs' behaviour. Furthermore, HR and HRV measures were affected by oxytocin treatment and in turn played a role in subjects' looking behaviour. We discuss how these findings contribute to our understanding of the neurohormonal regulatory mechanisms of human (and non-human) social skills. PMID:26742930

  10. Comment on ``Constraints on biological effects of weak extremely-low-frequency electromagnetic fields''

    Science.gov (United States)

    Kirschvink, Joseph L.

    1992-08-01

    In a recent paper, Adair [Phys. Rev. A 43, 1039 (1991)] concludes that weak extremely-low-frequency (ELF) electromagnetic fields cannot affect biology on the cell level. However, Adair's assertion that few cells of higher organisms contain magnetite (Fe3O4) and his blanket denial of reproducible ELF effects on animals are both wrong. Large numbers of single-domain magnetite particles are present in a variety of animal tissues, including up to a hundred million per gram in human brain tissues, organized in clusters of tens to hundreds of thousand per gram. This is far more than a ``few cells.'' Similarly, a series of reproducible behavioral experiments on honeybees, Apis mellifera, have shown that they are capable of responding to weak ELF magnetic fields that are well within the bounds of Adair's criteria. A biologically plausible model of the interaction of single-domain magnetosomes with a mechanically activated transmembrane ion channel shows that ELF fields on the order of 0.1 to 1 mT are capable of perturbing the open-closed state by an energy of kT. As up to several hundred thousand such structures could fit within a eukaryotic cell, and the noise should go as the square root of the number of independent channels, much smaller ELF sensitivities at the cellular level are possible. Hence, the credibility of weak ELF magnetic effects on living systems must stand or fall mainly on the merits and reproducibility of the biological or epidemiological experiments that suggest them, rather than on dogma about physical implausibility.

  11. Radiation effects analysis in a group of interventional radiologists using biological and physical dosimetry methods

    Energy Technology Data Exchange (ETDEWEB)

    Ramos, M., E-mail: WEMLmirapas@iqn.upv.e [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Montoro, A.; Almonacid, M. [Radiation Protection Service, Hospital Universitario La Fe Valencia (Spain); Ferrer, S. [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Barquinero, J.F. [Biological Dosimetry Service, Unit of Anthropology, Department of Animal and Vegetable Biology and Ecology, Universitat Autonoma de Barcelona (UAB) (Spain); Tortosa, R. [Radiation Protection Service, Hospital Universitario La Fe Valencia (Spain); Verdu, G. [Department of Chemical and Nuclear Engineering, Polytechnic University of Valencia, Camino de Vera s/n, 46022 Valencia (Spain); Rodriguez, P. [Biological Dosimetry Service, Unit of Anthropology, Department of Animal and Vegetable Biology and Ecology, Universitat Autonoma de Barcelona (UAB) (Spain); Barrios, L.L. [Department of Physiology and Cellular Biology, Unit of Cellular Biology (UAB) (Spain); Villaescusa, J.I. [Radiation Protection Service, Hospital Universitario La Fe Valencia (Spain)

    2010-08-15

    Interventional radiologists and staff members are frequently exposed to protracted and fractionated low doses of ionizing radiation, which extend during all their professional activities. These exposures can derive, due to the effects of direct and scattered radiation, in deterministic effects (radiodermitis, aged skin, cataracts, telangiectasia in nasal region, vasocellular epitelioms, hands depilation) and/or stochastic ones (cancer incidence). A methodology has been proposed for estimating the radiation risk or detriment from a group of six exposed interventional radiologists of the Hospital Universitario La Fe (Valencia, Spain), which had developed general exposition symptoms attributable to deterministic effects of ionizing radiation. Equivalent doses have been periodically registered using TLD's and wrist dosimeters, H{sub p}(10) and H{sub p}(0.07), respectively, and estimated through the observation of translocations in lymphocytes of peripheral blood (biological methods), by extrapolating the yield of translocations to their respective dose-effect curves. The software RADRISK has been applied for estimating radiation risks in these occupational radiation exposures. This software is based on transport models from epidemiological studies of population exposed to external sources of ionizing radiation, such as Hiroshima and Nagasaki atomic bomb survivors [UNSCEAR, Sources and effects of ionizing radiation: 2006 report to the general assembly, with scientific annexes. New York: United Nations; 2006]. The minimum and maximum average excess ratio for skin cancer has been, using wrist physical doses, of [1.03x10{sup -3}, 5.06x10{sup -2}], concluding that there is not an increased risk of skin cancer incidence. The minimum and maximum average excess ratio for leukemia has been, using TLD physical doses, of [7.84x10{sup -2}, 3.36x10{sup -1}], and using biological doses, of [1.40x10{sup -1}, 1.51], which is considerably higher than incidence rates, showing an

  12. Biological effects of pramipexole on dopaminergic neuron-associated genes: relevance to neuroprotection.

    Science.gov (United States)

    Pan, Tianhong; Xie, Wenjie; Jankovic, Joseph; Le, Weidong

    2005-03-29

    Pramipexole (PRX) is a non-ergot dopamine (DA) D2/D3 receptor agonist. Experimental studies have provided evidence that PRX may exert neuroprotective effects on the nigro-striatal system. Recent studies have demonstrated a slower decline of DAT density in Parkinson's disease patients treated with PRX as measured by SPECT. The aim of this study is to determine whether PRX has direct biological effects on DAergic neuron-associated genes expression, including DAT, VMAT2, and Nurr1. The human neuroblastoma SH-SY5Y cells were treated with PRX for various time periods and harvested to measure the mRNA and protein products of these genes. Treatment with PRX at 10 microM significantly increased DAT mRNA levels by 54-130% in 4-8 h, VMAT2 mRNA levels by 34% in 4 h, and Nurr1 mRNA levels by 31-39% in 2-4 h, which was the earliest induction among these three genes. The protein levels of DAT, VMAT2, and Nurr1 were markedly increased after PRX treatment, among which the increase of Nurr1 protein level was the highest at first 2 h treatment of PRX. Nafadotride, a D3 DA receptor antagonist, blocked the increase of Nurr1 gene expression induced by PRX, while eticlopride, a D2 DA receptor antagonist, didn't show this effect. Our findings that PRX has biological regulatory effects on DAergic neuron-associated genes may explain both the slower decline of imaged DAT and the neuroprotective effect of PRX. Furthermore, our results suggest that the induction of Nurr1 gene expression by PRX may be mediated by D3 DA receptor. PMID:15740846

  13. Effect of contrast agent administration on consequences of dosimetry and biology in radiotherapy planning

    Energy Technology Data Exchange (ETDEWEB)

    Lo, Ching-Jung [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Department of Radiation Oncology, Chang Gung Memorial Hospital, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Yang, Pei-Ying [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Chao, Tsi-Chian, E-mail: chaot@mail.cgu.edu.tw [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China); Tu, Shu-Ju, E-mail: sjtu@mail.cgu.edu.tw [Department of Medical Imaging and Radiological Sciences, College of Medicine, Chang Gung University, 259 Wen-Hua 1st Road, Kwei-Shan, Tao-Yuan 333 Taiwan (China)

    2015-06-01

    In the treatment planning of radiation therapy, patients may be administrated with contrast media in CT scanning to assist physicians for accurate delineation of the target or organs. However, contrast media are not used in patients during the treatment delivery. In particular, contrast media contain materials with high atomic numbers and dosimetric variations may occur between scenarios where contrast media are present in treatment planning and absent in treatment delivery. In this study we evaluate the effect of contrast media on the dosimetry and biological consequence. An analytical phantom based on AAPM TG 119 and five sets of CT images from clinical patients are included. Different techniques of treatment planning are considered, including 1-field AP, 2-field AP+PA, 4-field box, 7-field IMRT, and RapidArc. RapidArc is a recent technique of volumetric modulated arc therapy and is used in our study of contrast media in clinical scenarios. The effect of RapidArc on dosimetry and biological consequence for administration of contrast media in radiotherapy is not discussed previously in literature. It is shown that dose difference is reduced as the number of external beams is increased, suggesting RapidArc may be favored to be used in the treatment planning enhanced by contrast media. Linear trend lines are fitted for assessment of percent dose differences in the planning target volume versus concentrations of contrast media between plans where contrast media are present and absent, respectively.

  14. Biologically sensitive field-effect transistors: from ISFETs to NanoFETs.

    Science.gov (United States)

    Pachauri, Vivek; Ingebrandt, Sven

    2016-06-30

    Biologically sensitive field-effect transistors (BioFETs) are one of the most abundant classes of electronic sensors for biomolecular detection. Most of the time these sensors are realized as classical ion-sensitive field-effect transistors (ISFETs) having non-metallized gate dielectrics facing an electrolyte solution. In ISFETs, a semiconductor material is used as the active transducer element covered by a gate dielectric layer which is electronically sensitive to the (bio-)chemical changes that occur on its surface. This review will provide a brief overview of the history of ISFET biosensors with general operation concepts and sensing mechanisms. We also discuss silicon nanowire-based ISFETs (SiNW FETs) as the modern nanoscale version of classical ISFETs, as well as strategies to functionalize them with biologically sensitive layers. We include in our discussion other ISFET types based on nanomaterials such as carbon nanotubes, metal oxides and so on. The latest examples of highly sensitive label-free detection of deoxyribonucleic acid (DNA) molecules using SiNW FETs and single-cell recordings for drug screening and other applications of ISFETs will be highlighted. Finally, we suggest new device platforms and newly developed, miniaturized read-out tools with multichannel potentiometric and impedimetric measurement capabilities for future biomedical applications. PMID:27365038

  15. Physical Effects of Buckwheat Extract on Biological Membrane In Vitro and Its Protective Properties.

    Science.gov (United States)

    Włoch, Aleksandra; Strugała, Paulina; Pruchnik, Hanna; Żyłka, Romuald; Oszmiański, Jan; Kleszczyńska, Halina

    2016-04-01

    Buckwheat is a valuable source of many biologically active compounds and nutrients. It has properties that reduce blood cholesterol levels, and so reduces the risk of atherosclerosis, seals the capillaries, and lowers blood pressure. The aim of the study was to determine quantitative and qualitative characteristics of polyphenols contained in extracts from buckwheat husks and stalks, the biological activity of the extracts, and biophysical effects of their interaction with the erythrocyte membrane, treated as a model of the cell. An analysis of the extract's composition has shown that buckwheat husk and stalk extracts are a rich source of polyphenolic compounds, the stalk extracts showing more compounds than the husk extract. The study allowed to determine the location which incorporated polyphenols occupy in the erythrocyte membrane and changes in the membrane properties caused by them. It was found that the extracts do not induce hemolysis of red blood cells, causing an increase in osmotic resistance of erythrocytes. They affect mainly the hydrophilic region by changing the degree of order of the polar heads of lipids, but do little to change the fluidity of the membrane and its hydration. The results showed also that polyphenolic substances included in the extracts well protect the membranes of red blood cells against oxidation and exhibit anti-inflammatory effect. PMID:26581904

  16. Delayed biological effects of radiotherapy in 500 patients treated for cervical cancer

    International Nuclear Information System (INIS)

    The incidence of cancer of the uterine cervix is high in Ecuador, accounting for 45% of all cancer cases and 60% of cancer cases in women. This study considers the delayed biological effects of radiotherapy in 500 patients out of 3200 treated between 1957 and 1972. In spite of the large number of patients treated, it was possible to follow up only 500 cases because a large proportion were in stage IV of the disease and many did not return for clinical check-up. Therefore a report is made on a study of 500 cases, considering a survival of at least five years. The study shows what were the delayed biological effects of radiation treatment and also the frequency and chronology of the appearance of lesions. The following sequelae are studied: severe sclerosis of the skin and subcutaneous cell tissue, whether or not followed by necrosis; chronic oedema of the lower extremities which is conducive to the recurring phenomena of infection in those organs; damage to the pelvic girdle; coxo-femoral osteoarthrosis and necrosis of the femur head; fracture of the neck of the femur and the pubis; serious lesions in the bladder and in the rectosigmoid; radiation cancer. The patients in question were treated regularly and always by the same technique; it is therefore possible to know the relation between these lesions and the following factors: tumour dose administered; radiation quality; mode of treatment (radiation therapy, alone or associated, before or after surgery); age of the patients treated. (author)

  17. Gamma radiation effect on biological activity and enzymatic properties of snake venoms

    International Nuclear Information System (INIS)

    The effect of gamma radiation, from Co-60, on the biological activity and on some enzymatic activities, present in the venoms of Lachesis muta and Bothrops atrox, using samples of dried venom that had been irradiated at a dose of 0.1, 0.5 and 1.0 Mrad have been studied. Variations in the degree of hemorrhage and local necrosis were observed in albino mice injected subcutaneously with venoms of both types. The reduction of the biological activity was greater for the local hemorrhagic effect and was dependent on the doses of irradiation. The specific activity of various enzymes, present in both venoms, is affected by the gamma radiation, at a dose of 0.1 Mrad the order of increasing inactivation being: exonuclease (4%), phospholipase (24%), caseinolytic enzyme (20%), tamesterase (33%), a thrombine-like enzyme (40%), fibrinolytic enzyme (41%), 5'-nucleotidase (50%) and endonuclease (55%). The enzymatic inactivation was augmented by 0.5 and 1.0 Mrad, without maintaining an arithmetic relation. The enzyme of major resistance to the radiation was exonuclease, whereas 5'-nucleotidase and endonuclease were the most sensitive. No significant changes were observed in the spectrum of UV absorbtion (range 260 to 290 nm) nor in the contents of L-tyrosine in the irradiated venoms

  18. Biological Effects of Osteoblast-Like Cells on Nanohydroxyapatite Particles at a Low Concentration Range

    Directory of Open Access Journals (Sweden)

    Xiaochen Liu

    2011-01-01

    Full Text Available The biological effects of osteoblast-like MG-63 cells on nanohydroxyapatite (n-HA at the low concentration range (5–25 g/mL for 5 days was investigated. The results showed the viability and actin cytoskeleton of the cells descended with the increase of the concentration of n-HA, and the actin cytoskeleton of cells was depolymerised and became more disordered. Apoptotic rate of cells (1.85%, 1.99%, and 2.29% increased with the increase of n-HA concentration (5, 15, and 25 g/mL and become significantly higher than the control. Total intracellular protein content decreased with n-HA concentration increase, showing significant difference between 25 g/mL and the control, and no significant change of ALP activity was observed at the 5th day. The results revealed that the cell growth was inhibited by n-HA in a concentration-dependent manner, and the obvious biological effects of MG-63 cells on n-HA existed at the low concentration range from 5 to 25 g/mL.

  19. A perspective on dose limits and biological effects of radiation on the foetus

    International Nuclear Information System (INIS)

    The potential biological effects of radiation doses to pregnant workers consistent with Canadian regulations and ICRP recommendations are reviewed. These hazards are in general very small compared to the normal hazards associated with human development. Potential carcinogenic effects may well be the major biological problem associated with foetal exposures. Radiation hazards to the embryo are essentially zero for exposures occurring during the first four weeks after conception. The new ICRP recommendations on exposures of pregnant women suggest a number of problems to be solved. These include (a) improvements in current methods of measuring both external radiation doses and intakes of certain radionuclides in Canada, (b) further research on the metabolism of radionuclides in pregnant women, including concentrations of certain radionuclides in foetal/embryonic tissues and also in adjacent tissues of the mother; and (c) socio-economic problems that may be involved in the implementation of the recommendations on exposures of pregnant workers, particularly in small facilities such as nuclear medicine departments in hospitals. (Author) 3 tabs., 21 refs

  20. Emphasizing Malleability in the biology of depression: Durable effects on perceived agency and prognostic pessimism.

    Science.gov (United States)

    Lebowitz, Matthew S; Ahn, Woo-kyoung

    2015-08-01

    Biological attributions for depression, which are currently ascendant, can lead to prognostic pessimism-the perception that symptoms are relatively immutable and unlikely to abate (Kvaale, Haslam, & Gottdiener, 2013; Lebowitz, Ahn, & Nolen-Hoeksema, 2013). Among symptomatic individuals, this may have important clinical ramifications, as reduced confidence in one's own ability to overcome depression carries the risk of becoming a self-fulfilling prophecy. Previous research (Lebowitz, Ahn, et al., 2013) has demonstrated that educational interventions teaching symptomatic individuals about how the effects of genetic and neurobiological factors involved in depression are malleable and can be modified by experiences and environmental factors can reduce prognostic pessimism. While previous research demonstrated such effects only in the immediate term, the present research extends these findings by testing whether such benefits persist six weeks after the intervention. Indeed, among individuals who initially considered biological factors to play a major role in influencing their levels of depression, exposure to malleability-focused psychoeducation reduced levels of depression-related prognostic pessimism and stronger belief in their ability to regulate their moods. Critically, this benefit persisted six weeks after the intervention. Clinical implications of the findings are discussed. PMID:26112398

  1. Effect of non-crop vegetation types on conservation biological control of pests in olive groves

    Directory of Open Access Journals (Sweden)

    Daniel Paredes

    2013-07-01

    Full Text Available Conservation biological control (CBC is an environmentally sound potential alternative to the use of chemical insecticides. It involves modifications of the environment to promote natural enemy activity on pests. Despite many CBC studies increasing abundance of natural enemies, there are far fewer demonstrations of reduced pest density and very little work has been conducted in olive crops. In this study we investigated the effects of four forms of non-crop vegetation on the abundance of two important pests: the olive psyllid (Euphyllura olivina and the olive moth (Prays oleae. Areas of herbaceous vegetation and areas of woody vegetation near olive crops, and smaller patches of woody vegetation within olive groves, decreased pest abundance in the crop. Inter-row ground covers that are known to increase the abundance of some predators and parasitoids had no effect on the pests, possibly as a result of lack of synchrony between pests and natural enemies, lack of specificity or intra-guild predation. This study identifies examples of the right types of diversity for use in conservation biological control in olive production systems.

  2. Gender Inequality in Biology Classes in China and Its Effects on Students' Short-Term Outcomes

    Science.gov (United States)

    Liu, Ning; Neuhaus, Birgit

    2014-07-01

    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. Each teacher was videotaped for 1 lesson on the topic blood and circulatory system. Before and after the lessons, the students completed tests and questionnaires. Chi-square analysis was conducted to compare the boys' and girls' participation rates of answering teachers' questions in the lessons. The findings revealed that in the urban classrooms the boys had a significantly higher rate of participation than did the girls, and hence also a higher situational interest. However, no such gender inequity was found among the rural students. The study also revealed that urban students answered more complicated questions compared with the rural students in general. The findings of this study suggest that the teachers should try to balance boys' and girls' participation and involve more students in answering questions in their lessons. The study also raises questions about long-term effects of students' participation in answering teachers' questions on their outcomes-knowledge achievement, situational interest and SET.

  3. Comparison of the biological effects of {sup 18}F at different intracellular levels

    Energy Technology Data Exchange (ETDEWEB)

    Kashino, Genro, E-mail: kashino@oita-u.ac.jp [Advanced Molecular Imaging Center, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593 (Japan); Hayashi, Kazutaka; Douhara, Kazumasa [Advanced Molecular Imaging Center, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593 (Japan); Kobashigawa, Shinko; Mori, Hiromu [Department of Radiology, Faculty of Medicine, Oita University, 1-1 Idaigaoka, Hasama-machi, Yufu City, Oita 879-5593 (Japan)

    2014-11-07

    Highlights: • We estimated the inductions of DNA DSB in cell treated with {sup 18}F-FDG. • We found that inductions of DNA DSB are dependent on accumulation of {sup 18}F in cell. • Accumulation of {sup 18}F in cell may be indispensable for risk estimation of PET. - Abstract: We herein examined the biological effects of cells treated with {sup 18}F labeled drugs for positron emission tomography (PET). The relationship between the intracellular distribution of {sup 18}F and levels of damaged DNA has yet to be clarified in detail. We used culture cells (Chinese Hamster Ovary cells) treated with two types of {sup 18}F labeled drugs, fluorodeoxyglucose (FDG) and fluorine ion (HF). FDG efficiently accumulated in cells, whereas HF did not. To examine the induction of DNA double strand breaks (DSB), we measured the number of foci for 53BP1 that formed at the site of DNA DSB. The results revealed that although radioactivity levels were the same, the induction of 53BP1 foci was stronger in cells treated with {sup 18}F-FDG than in those treated with {sup 18}F-HF. The clonogenic survival of cells was significantly lower with {sup 18}F-FDG than with {sup 18}F-HF. We concluded that the efficient accumulation of {sup 18}F in cells led to stronger biological effects due to more severe cellular lethality via the induction of DNA DSB.

  4. Effect of contrast agent administration on consequences of dosimetry and biology in radiotherapy planning

    International Nuclear Information System (INIS)

    In the treatment planning of radiation therapy, patients may be administrated with contrast media in CT scanning to assist physicians for accurate delineation of the target or organs. However, contrast media are not used in patients during the treatment delivery. In particular, contrast media contain materials with high atomic numbers and dosimetric variations may occur between scenarios where contrast media are present in treatment planning and absent in treatment delivery. In this study we evaluate the effect of contrast media on the dosimetry and biological consequence. An analytical phantom based on AAPM TG 119 and five sets of CT images from clinical patients are included. Different techniques of treatment planning are considered, including 1-field AP, 2-field AP+PA, 4-field box, 7-field IMRT, and RapidArc. RapidArc is a recent technique of volumetric modulated arc therapy and is used in our study of contrast media in clinical scenarios. The effect of RapidArc on dosimetry and biological consequence for administration of contrast media in radiotherapy is not discussed previously in literature. It is shown that dose difference is reduced as the number of external beams is increased, suggesting RapidArc may be favored to be used in the treatment planning enhanced by contrast media. Linear trend lines are fitted for assessment of percent dose differences in the planning target volume versus concentrations of contrast media between plans where contrast media are present and absent, respectively

  5. Biological effects induced by low-density heavy ions of space radiation in medaka

    International Nuclear Information System (INIS)

    Starting Japanese astronauts staying in the International Space Station (ISS), influences of the radiation on human is becoming one of the important risks during space flight. Although the biological effect with high-dose acute irradiation has been examined by epidemiological studies for many years, the risks either acute or chronic with low-dose or low-fluence irradiation equivalent of space environment can only be estimated based on the data with high-dose or high-fluence at present. Our aim is to understand biological influences on living organisms induced by low-dose and low-fluence chronic irradiation (1 mGy/7-8 h) that assumes the space radiation in ISS. So that we focused on the gene and protein expression, and the possibility on carcinogenesis induced by low-dose and -fluence radiation, and planed the experiments to irradiate medaka carbon ions using Heavy Ion Medical Accelerator in Chiba (HIMAC) in National Institute of Radiological Sciences (NIRS). This year, we established the irradiation method to treat medaka with low-dose and -fluence (1 mGy/7-8 h) carbon ions. Also we extracted total RNA from medaka scales and skins to evaluate the effect of irradiation. (author)

  6. Characterization and biological effect of Buenos Aires urban air particles on mice lungs

    International Nuclear Information System (INIS)

    Exposure to increased levels of ambient air particulate matter (PM) is associated with increased cardiopulmonary morbidity and mortality. Its association with adverse health effects and the still unclear mechanisms of action are of concern worldwide. Our objective was to analyze air PM from downtown Buenos Aires (UAP-BA), and evaluate its biological impact on normal airways. We studied the inflammatory response to intranasal instillation of UAP-BA in a short-term-exposure mouse model. We analyzed UAP-BA morphology by scanning electron microscopy and characterized particle chemical composition by energy dispersive X-ray analysis and capillary gas chromatography. We evaluated lung changes by histomorphometry and histochemical methods. Regarding size, surface area and distribution, UAP-BA proved to be small spherical ultrafine particles: free, in clusters and associated to a matrix. The particles contained polycyclic aromatic hydrocarbons, polychlorinated biphenyls and almost no metal traces. Histologically, UAP-BA induced the recruitment of phagocytes, a reduction in air spaces, an increase in mucous PAS positive cells and weak incomplete elastic fiber network. Our results demonstrate that UAP-BA causes adverse biological effects on the respiratory tract generating inflammation that, in turn, may cause tissue injury or organ dysfunction and may contribute to the pathogenesis of lung diseases

  7. The effects of a formal notebook on learning achievement of tenth grade biology students

    Science.gov (United States)

    Hirst, Sabine Korpus

    Despite the national agenda for achieving scientific literacy for all American students, there appears to be a paucity of research on the role of writing and, more specifically, on the organization of students' notes. The use of student notebooks as an ongoing record of both the process function and product function of notetaking has received little attention in the American research literature reviewed. The purposes of this study were to investigate if (a) the use of a formal notebook has a positive effect on learning achievement by high school biology students, (b) the gender of the biology student makes a difference with regard to the effect of keeping a formal notebook, (c) students perceive notetaking skills as an important set of study skills, and (d) students regard keeping a formal notebook as a valuable tool for improving learning outcomes. A quasi-experimental study was conducted, using a matching-only posttest control group design. A purposive cluster sample of four intact tenth grade biology classes with a total of 126 students from two Brevard County public high schools was used. The design resulted in two experimental conditions for the independent variable: (a) notebook treatment and (b) no notebook control. In each school, one class was randomly assigned to either the treatment or control group. A Study Skills Questionnaire was pilot-tested, revised, and administered to all students as a pre-assessment to determine if notetaking was regarded as important. One teacher-made posttest was used to measure learning achievement in biology as a consequence of the experimental conditions. A researcher-developed six-item postquestionnaire was only administered to the students of the treatment groups to determine if students perceive the requirement of keeping a formal notebook as a valuable learning tool. A factorial independent measures analysis of variance (2 x 2 x 2 ANOVA) was used to determine the effects of experimental group, school, gender, and their

  8. Development and effectiveness of an educational card game as supplementary material in understanding selected topics in biology.

    Science.gov (United States)

    Gutierrez, Arnel F

    2014-01-01

    The complex concepts and vocabulary of biology classes discourage many students. In this study, a pretest-posttest model was used to test the effectiveness of an educational card game in reinforcing biological concepts in comparison with traditional teaching methods. The subjects of this study were two biology classes at Bulacan State University-Sarmiento Campus. Both classes received conventional instruction; however, the experimental group's instruction was supplemented with the card game, while the control group's instruction was reinforced with traditional exercises and assignments. The score increases from pretest to posttest showed that both methods effectively reinforced biological concepts, but a t test showed that the card game is more effective than traditional teaching methods. Additionally, students from the experimental group evaluated the card game using five criteria: goals, design, organization, playability, and usefulness. The students rated the material very satisfactory. PMID:24591506

  9. The central effect of biological Amines on immunosuppressive effect of restraint stress in rat

    OpenAIRE

    Zeraati F; Ghafghazi T.; Adib M; Rezaei A

    2000-01-01

    The effects of some histaminergic agents were evaluated on stress- induced immunosuppression in immunized nale rats. In rat immunized with sheep red blood cells ( SRBCs). Restraint stress (RS) prevented the booster-induced rise in anti-SRBC antibody titre and cell immunity response. Intracerebroventicular (I.C>V) injection of histamine (150 µg/rat) induced a similar effect with RS. Pretreatment with chlorpheniramine (50 µg/rat) reduced the inhibitory effect of Ras on immune function. Also ...

  10. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Xu Gang, E-mail: xg335300@yahoo.com.cn [Center for Research and Development of Fine Chemicals, Guizhou University, Guiyang 550025 (China); Institute of Entomology, Guizhou University, Guiyang 550025 (China); Wang Xiaoteng [Department of Agricultural Resources and Environment, College of Agricultural, Guizhou University, Guiyang 550025 (China); Gan Cailing; Fang Yanqiong; Zhang Meng [College of Life Sciences, Guizhou University, Guiyang 550025 (China)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer We analyzed biological effects of N{sup +} implantation on dry Jatropha curcas seed. Black-Right-Pointing-Pointer N{sup +} implantation greatly decreased seedling survival rate. Black-Right-Pointing-Pointer At doses beyond 15 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place. Black-Right-Pointing-Pointer CAT was essential for H{sub 2}O{sub 2} removal. POD mainly functioned as seed was severely hurt. Black-Right-Pointing-Pointer HAsA-GSH cycle mainly contributed to the regeneration of HAsA. - Abstract: To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N{sup +} with energy of 25 keV was applied to treat the dry seed at six different doses. N{sup +} beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 Multiplication-Sign 10{sup 16} to 15 Multiplication-Sign 10{sup 16} ions cm{sup -2} severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 Multiplication-Sign 10{sup 16} ion cm{sup -2}, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 Multiplication-Sign 10{sup 16} ions cm{sup -2} may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  11. The central effect of biological Amines on immunosuppressive effect of restraint stress in rat

    Directory of Open Access Journals (Sweden)

    Zeraati F

    2000-10-01

    Full Text Available The effects of some histaminergic agents were evaluated on stress- induced immunosuppression in immunized nale rats. In rat immunized with sheep red blood cells ( SRBCs. Restraint stress (RS prevented the booster-induced rise in anti-SRBC antibody titre and cell immunity response. Intracerebroventicular (I.C>V injection of histamine (150 µg/rat induced a similar effect with RS. Pretreatment with chlorpheniramine (50 µg/rat reduced the inhibitory effect of Ras on immune function. Also histamine could inhibit the effect of RS on immune function. Also histamine could inhibitory the effect of chlorpheniramine when injected simultaneously. Pretreatment with ranidine (10 µg/rat had not a significant effect. Serotonin (3 µg/rat and dopamine (0.2 µg/rat could reverse the effects of chlorpheniromine when injected with chlorpheniramine (P<0.05. Epinephrine (0.2 µg/rat had not a significant effect. The results indicate that histamine mediates the immunosuppression of restraint stress by influencing the histamine H1 receptor in the brain and this effects of histamine may be modulated by serotoninergic and dopaminergic system.

  12. Effects of added ZnTCP on mechanical and biological properties of apatite cement

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, K.; Suzuki, K. [Okayama Univ. Dental School (Japan). Dept. of Biomaterials; Miyamoto, Y.; Toh, T.; Yuasa, T.; Nagayama, M. [Tokushima Univ. (Japan). First Dept. of Oral and Maxillofacial Surgery; Ito, A. [National Inst. for Advanced Interdisciplinary Research, MITT, Ibaragi (Japan)

    2001-07-01

    Effects of added Zn doped {beta}-tricalcium phosphate (ZnTCP) on mechanical and biological properties of apatite cement (AC) was studied. Powder X-ray diffractometer revealed that ZnTCP shows no reactivity with AC. The mechanical strength of AC decreased increasing amounts of added ZnTCP. We observed no effect on the setting time of AC when the amount of ZnTCP was 10% or less. Proliferation of the osteoblastic cells was significantly increased on the surface of AC containing 5% ZnTCP when compared with that containing no ZnTCP. In contrast, proliferation of the cells decreased on the surface of AC containing 10% ZnTCP when compared with that free from ZnTCP; indicating cytotoxity. We concluded therefore, that addition of ZnTCP to AC might be useful to enhance the osteoconductivity of AC when release of Zn{sup 2+} can be carefully regulated. (orig.)

  13. Effects of exercise on knee joints with osteoarthritis: a pilot study of biologic markers

    Science.gov (United States)

    Bautch, J. C.; Malone, D. G.; Vailas, A. C.

    1997-01-01

    OBJECTIVE: To determine the effects of low intensity weight-bearing exercise on osteoarthritis (OA) of the knee. METHODS: Synovial fluid keratan sulfate (KS) and hydroxyproline were measured as markers of cartilage degradation. The Arthritis Impact Measurement Scales (AIMS) were used to measure health status, and a visual analog scale for pain assessment was used before and after intervention. An exercise (EX) group (n = 15) received a thrice-weekly 12-week low intensity exercise program and a weekly educational program, and a minimal treatment (Min RX) group (n = 15) received only the education program. RESULTS: Pain levels declined in the EX group, and the Min RX group showed improvement on the AIMS. Synovial fluid was obtained in 11 subjects before and after the intervention. Levels of KS and hydroxyproline did not change. CONCLUSION: Further study of exercise effects should include both clinical and biologic parameters to examine the outcome of exercise as a therapeutic intervention in OA of the knee.

  14. Effect of Emodin on Biological Behavior of Fibroblasts in Lupus Nephritis

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To observe the effect of emodin on the biological behavior of human fibroblasts (FB) in culture of kidney in patients with lupus nephritis (LN). Methods: FB were isolated from kidney culture of LN patients, and the effect of emodin on 3 H-TdR incorporated rate of FB was observed. The apoptosis and c-myc gene expression were detected in the same way by flow cytometry. Results: Emodin could markedly inhibit the proliferation of human kidney FB, and inducing cell apoptosis through up-regulating c-myc gene expression in human renal FB. Conclusion: Emodin can inhibit proliferation and promote apoptosis of FB, which may be important in ameliorating interstitial fibrosis, and thus improve prognosis of LN.

  15. Effect of three biological response modifiers on chemical carcinogenesis in mice.

    Science.gov (United States)

    Bogdanović, Z; Culo, F; Marusić, M

    1993-01-01

    The modulation of chemical carcinogenesis by three biological response modifiers was assessed in a mouse model. CBA mice given 20-methylcholanthrene s.c. were treated with peptidoglycan monomer, azure B and indomethacin for one month, either from day 0 or 75 after methylcholanthrene injection to assess their effects on tumor incidence (on days 150 and 300), time of tumor appearance, time of death, and duration and dynamics of tumor growth. All three agents significantly influenced some of the parameters of tumor growth, except tumor incidence on day 300. Highly significant sex differences in tumor appearance and growth were observed. Tumors with late appearance grew faster in comparison to tumors with early appearance. The data presented indicate that the effectiveness of anti-cancer body defense mechanisms can be best defined by the time of tumor appearance. PMID:8272149

  16. [New data on pumice's structure and biological effects among miners and millers].

    Science.gov (United States)

    Spatari, G; Barbaro, M; Pira, E; Rossi, F; Massiccio, M; Romano, C

    2011-01-01

    Pleural plaques among pumice workers on Lipari Island have been described and the Authors have suggested the hypothesis that such biological effect could be related to the particles' morphology characterized by the presence of elements similar to fibers. Analysis on compact bulk materials and on dust samples from different sites of the Island have been performed to obtain information on the chemical composition of such materials. The Scan Electron Microscopy (SEM) analyses confirm the presence of fibrous particles with a chemical structure similar to the Refractory Ceramic Fibers (RCF) composition. These results could explain the presence of plural plaques among the workers and new clinical and epidemiological evaluations of the potential effects associated to this exposure are needed. PMID:23393860

  17. Expected time-invariant effects of biological traits on mammal species duration.

    Science.gov (United States)

    Smits, Peter D

    2015-10-20

    Determining which biological traits influence differences in extinction risk is vital for understanding the differential diversification of life and for making predictions about species' vulnerability to anthropogenic impacts. Here I present a hierarchical Bayesian survival model of North American Cenozoic mammal species durations in relation to species-level ecological factors, time of origination, and phylogenetic relationships. I find support for the survival of the unspecialized as a time-invariant generalization of trait-based extinction risk. Furthermore, I find that phylogenetic and temporal effects are both substantial factors associated with differences in species durations. Finally, I find that the estimated effects of these factors are partially incongruous with how these factors are correlated with extinction risk of the extant species. These findings parallel previous observations that background extinction is a poor predictor of mass extinction events and suggest that attention should be focused on mass extinctions to gain insight into modern species loss. PMID:26438873

  18. Characteristics of the Biological Effects and the RBE of High Energy Protons

    International Nuclear Information System (INIS)

    The characteristics of the biological effects of high-energy protons (120, 240 and 510 MeV) were studied in experiments on mice, rats and dogs. It was shown that together with a certain resemblance or identity in radiation damage due to the effects of X-rays and protons, there were certain differences in the case of proton irradiation. In the proton irradiation of dogs the haemorrhagic syndrome was more pronounced. Haemorrhage appeared earlier in the animals and was more abundant. A difference was found in proton RBE levels for small animals (rats, mice) and large animals (dogs). This difference is quite large and equals respectively 0.7 and 1.0 * 1.15. Some considerations are presented in the report on the cause of these differences. (author)

  19. Presence and biological effects of emerging contaminants in Llobregat River basin: A review

    International Nuclear Information System (INIS)

    Llobregat River (North-East Spain) is the most important drinking water source for Barcelona and its surrounding area. As one of the only water sources in the area the river water have been overexploited and effluents from more than 30 urban wastewater treatment plants, industries and agriculture runoffs have been discharged into the river. This article reviews the presence of emerging contaminants published during the last decades, emphasizing on the observed effects on ecosystems caused by the contamination. Pesticides, surfactants, estrogens, pharmaceuticals and personal care products and even abuse drugs are the main groups detected in different studies, reporting alterations in species composition, abundance or biomass and endocrine disruption measured by alterations in enzymatic activity or specific protein production. The information available provides an overview of the river status according to the Water Framework Directive. - The presence of different pollutants (mainly pesticides, pharmaceuticals, surfactants and estrogens) and their biological effects in the Llobregat River are reviewed.

  20. Biological effects of long term fine limestone tailings discharge in a fjord ecosystem.

    Science.gov (United States)

    Brooks, Lucy; Melsom, Fredrik; Glette, Tormod

    2015-07-15

    Benthic infaunal data collected from 1993 to 2010 were analysed to examine the effect of long term discharge of fine limestone tailings on macrofaunal species assemblages in a fjord. Relative distance from the outfall and proportion of fine tailings in the sediment were correlated with benthic community structure. Diversity decreased with increasing proportion of fine tailings. Biological Traits Analysis (BTA) was used to explore the temporal and spatial effects of the tailings gradient on macrofaunal functional attributes. BTA revealed that all stations along a pressure gradient of fine limestone tailings were dominated by free-living species. As the proportion of fine tailings in the sediment increased, there was an increase in fauna that were smaller, highly mobile, living on or nearer the surface sediment, with shorter lifespans. There was a decrease in permanent tube dwellers, those fauna with low or no mobility, that live deeper in the sediment and have longer lifespans (>5 yrs). PMID:25960275

  1. Study of cardiovascular disease biomarkers among tobacco consumers, part 2: biomarkers of biological effect.

    Science.gov (United States)

    Nordskog, Brian K; Brown, Buddy G; Marano, Kristin M; Campell, Leanne R; Jones, Bobbette A; Borgerding, Michael F

    2015-02-01

    An age-stratified, cross-sectional study was conducted in the US among healthy adult male cigarette smokers, moist snuff consumers, and non-tobacco consumers to evaluate cardiovascular biomarkers of biological effect (BoBE). Physiological assessments included flow-mediated dilation, ankle-brachial index, carotid intima-media thickness and expired carbon monoxide. Approximately one-half of the measured serum BoBE showed statistically significant differences; IL-12(p70), sICAM-1 and IL-8 were the BoBE that best differentiated among the three groups. A significant difference in ABI was observed between the cigarette smokers and non-tobacco consumer groups. Significant group and age effect differences in select biomarkers were identified. PMID:25787701

  2. Study of cardiovascular disease biomarkers among tobacco consumers, part 2: biomarkers of biological effect

    Science.gov (United States)

    Nordskog, Brian K.; Brown, Buddy G.; Marano, Kristin M.; Campell, Leanne R.; Jones, Bobbette A.; Borgerding, Michael F.

    2015-01-01

    Abstract An age-stratified, cross-sectional study was conducted in the US among healthy adult male cigarette smokers, moist snuff consumers, and non-tobacco consumers to evaluate cardiovascular biomarkers of biological effect (BoBE). Physiological assessments included flow-mediated dilation, ankle-brachial index, carotid intima-media thickness and expired carbon monoxide. Approximately one-half of the measured serum BoBE showed statistically significant differences; IL-12(p70), sICAM-1 and IL-8 were the BoBE that best differentiated among the three groups. A significant difference in ABI was observed between the cigarette smokers and non-tobacco consumer groups. Significant group and age effect differences in select biomarkers were identified. PMID:25787701

  3. Molecular Signaling Pathways Behind the Biological Effects of Salvia Species Diterpenes in Neuropharmacology and Cardiology.

    Science.gov (United States)

    Akaberi, M; Iranshahi, M; Mehri, S

    2016-06-01

    The genus Salvia, from the Lamiaceae family, has diverse biological properties that are primarily attributable to their diterpene contents. There is no comprehensive review on the molecular signaling pathways of these active components. In this review, we investigated the molecular targets of bioactive Salvia diterpenes responsible for the treatment of nervous and cardiovascular diseases. The effects on different pathways, including apoptosis signaling, oxidative stress phenomena, the accumulation of amyloid beta plaques, and tau phosphorylation, have all been considered to be mechanisms of the anti-Alzheimer properties of Salvia diterpenes. Additionally, effects on the benzodiazepine and kappa opioid receptors and neuroprotective effects are noted as neuropharmacological properties of Salvia diterpenes, including tanshinone IIA, salvinorin A, cryptotanshinone, and miltirone. Tanshinone IIA, as the primary diterpene of Salvia miltiorrhiza, has beneficial activities in heart diseases because of its ability to scavenge free radicals and its effects on transcription factors, such as nuclear transcription factor-kappa B (NF-κB) and the mitogen-activated protein kinases (MAPKs). Additionally, tanshinone IIA has also been proposed to have cardioprotective properties including antiarrhythmic activities and effects on myocardial infarction. With respect to the potential therapeutic effects of Salvia diterpenes, comprehensive clinical trials are warranted to evaluate these valuable molecules as lead compounds. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26988179

  4. The biological effect of large single doses: a possible role for non-targeted effects in cell inactivation.

    Directory of Open Access Journals (Sweden)

    Marlon R Veldwijk

    Full Text Available BACKGROUND AND PURPOSE: Novel radiotherapy techniques increasingly use very large dose fractions. It has been argued that the biological effect of large dose fractions may differ from that of conventional fraction sizes. The purpose was to study the biological effect of large single doses. MATERIAL AND METHODS: Clonogenic cell survival of MCF7 and MDA-MB-231 cells was determined after direct X-ray irradiation, irradiation of feeder cells, or transfer of conditioned medium (CM. Cell-cycle distributions and the apoptotic sub-G1 fraction were measured by flow cytometry. Cytokines in CM were quantified by a cytokine antibody array. γH2AX foci were detected by immunofluorescence microscopy. RESULTS: The surviving fraction of MCF7 cells irradiated in vitro with 12 Gy showed an 8.5-fold decrease (95% c.i.: 4.4-16.3; P<0.0001 when the density of irradiated cells was increased from 10 to 50×10(3 cells per flask. Part of this effect was due to a dose-dependent transferrable factor as shown in CM experiments in the dose range 5-15 Gy. While no effect on apoptosis and cell cycle distribution was observed, and no differentially expressed cytokine could be identified, the transferable factor induced prolonged expression of γH2AX DNA repair foci at 1-12 h. CONCLUSIONS: A dose-dependent non-targeted effect on clonogenic cell survival was found in the dose range 5-15 Gy. The dependence of SF on cell numbers at high doses would represent a "cohort effect" in vivo. These results support the hypothesis that non-targeted effects may contribute to the efficacy of very large dose fractions in radiotherapy.

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

    International Nuclear Information System (INIS)

    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

  6. Relative biological effectiveness in canine osteosarcoma cells irradiated with accelerated charged particles

    Science.gov (United States)

    Maeda, Junko; Cartwright, Ian M.; Haskins, Jeremy S.; Fujii, Yoshihiro; Fujisawa, Hiroshi; Hirakawa, Hirokazu; Uesaka, Mitsuru; Kitamura, Hisashi; Fujimori, Akira; Thamm, Douglas H.; Kato, Takamitsu A.

    2016-01-01

    Heavy ions, characterized by high linear energy transfer (LET) radiation, have advantages compared with low LET protons and photons in their biological effects. The application of heavy ions within veterinary clinics requires additional background information to determine heavy ion efficacy. In the present study, comparison of the cell-killing effects of photons, protons and heavy ions was investigated in canine osteosarcoma (OSA) cells in vitro. A total of four canine OSA cell lines with various radiosensitivities were irradiated with 137Cs gamma-rays, monoenergetic proton beams, 50 keV/µm carbon ion spread out Bragg peak beams and 200 keV/µm iron ion monoenergetic beams. Clonogenic survival was examined using colony-forming as says, and relative biological effectiveness (RBE) values were calculated relative to gamma-rays using the D10 value, which is determined as the dose (Gy) resulting in 10% survival. For proton irradiation, the RBE values for all four cell lines were 1.0–1.1. For all four cell lines, exposure to carbon ions yielded a decreased cell survival compared with gamma-rays, with the RBE values ranging from 1.56–2.10. Iron ions yielded the lowest cell survival among tested radiation types, with RBE values ranging from 3.51–3.69 observed in the three radioresistant cell lines. The radiosensitive cell line investigated demonstrated similar cell survival for carbon and iron ion irradiation. The results of the present study suggest that heavy ions are more effective for killing radioresistant canine OSA cells when compared with gamma-rays and protons. This markedly increased efficiency of cell killing is an attractive reason for utilizing heavy ions for radioresistant canine OSA. PMID:27446477

  7. Research into the biological effects of ionizing radiation somatic effects II: non-cancer

    International Nuclear Information System (INIS)

    Somatic effects of radiation can be considered in two categories: low and high level effects. In the low level exposure region (defined here arbitrarily as a single dose of the order of 10 rads or less, or higher doses at very low dose rates), the only somatic effects other than cancer known definitely at present to have health significance are those on fertiltiy and on the developing individual from conception to near birth. Knowledge of these effects is inadequate at present, and the bulk of this report will be devoted to discussing the types of additional investigations required. With respect to non-cancer somatic effects of radiation at intermediate to high doses and dose rates, enough is known to describe in general the course of early (over the first days to perhaps six weeks) effects, following different doses of external radiation. In particular, the non-cancer late effects of intermediate to high doses of internal and external radiation need better definition. The distinction between non-cancer and cancer-related somatic effects is blurred, at least at high dose levels

  8. 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

  9. Effect of grain size on mechanical, surface and biological properties of microwave sintered hydroxyapatite

    Energy Technology Data Exchange (ETDEWEB)

    Dasgupta, Sudip; Tarafder, Solaiman; Bandyopadhyay, Amit; Bose, Susmita, E-mail: sbose@wsu.edu

    2013-07-01

    Hydroxyapatite (HA) compacts having average grain sizes of 168 ± 0.086 nm, 1.48 ± 0.627 μm and 5.01 ± 1.02 μm are processed from synthesized HA powder by microwave sintering at varying sintering temperature for different times. Superior mechanical and biological properties are shown by nano-grain HA compacts as compared to their micron grained counterparts. Compressive strength, indentation hardness, and indentation fracture toughness are increased with the decrease in HA grain size. The highest surface energy and maximum wettability are exhibited by nano-grain HA. HA compacts are assessed for cell–material interaction by SEM, MTT and immunochemistry assays using human osteoblast cell line for 1, 5 and 11 days. MTT assays showed higher number of living cells and faster proliferation on nano-grain HA surface. Osteoblast cells on nano-grain HA surface expressed significantly higher amount of vinculin and alkaline phosphatase (ALP) protein markers for cell adhesion and differentiation respectively. This study shows the effect of grain size on physical, mechanical and in vitro biological properties of microwave sintered HA compacts. - Highlights: • Nano- and micro-grain HA compacts are prepared by microwave sintering. • Uniform heating and shorter time by microwave sintering result in finer grains. • Grain size significantly affected physical, mechanical and biological properties. • Nano-grain HA also exhibited the highest surface energy and maximum wettability. • Significantly higher amounts of vinculin and ALP were expressed on nano-grain HA.

  10. The complicated effects of cross-age tutoring on biology students

    Science.gov (United States)

    Merrill, Marcy Ellen

    When traditional modes of instruction are unsuccessful with low-level students, and bad habits in school are routine, alternate methods provide a more effective educational experience. Cross-age tutoring is one intervention that has demonstrated success. This study was designed to help high school students who read at least 3 grades below grade level to succeed in biology. Seventy-four ninth grade biology students, taught to use reading strategies, were randomly selected into four groups. One group acted as tutees, with support from tutors from a nearby university; one group tutored at an urban elementary school; one group was the control and received no treatment; and one group had both treatments. The experiment examined if membership in one group affected scores on the state test; grades; word recognition abilities, timed and untimed; days present in school; and/or behavior. It also explored how tutoring contributed over and above the demographic factors of race and gender. To test tutoring effects, analyses were comprised of two components: a descriptive piece using ANOVAs, and a predictive piece using a step-wise regression. Results showed that tutors of elementary students did improve significantly in word recognition scores, untimed. No significant differences among groups on the other five measures existed, although the interaction effects showed significant differences for tutors in biology grades and attendance. White tutors had significantly higher grades than African American tutors. Male tutors missed more days from school, and white students missed more days than African American students. A significant gender effect was found in the behavior measure; males received a significantly greater number of discipline referrals than females. Four recommendations are suggested for further study, and two conclusions were drawn. It is possible that students, even when they resist school regimens, are still able to improve their reading when they have one or more

  11. What are the Effects of Implementing Learning-Focused Strategies in Biology and Physical Science Classrooms?

    Science.gov (United States)

    Simmons, Robin

    The objective of this study was to determine if Learning-Focused Strategies (LFS) implemented in high school science courses would affect student achievement and the pass rate of biology and physical science Common District Assessments (CDAs). The LFS, specific teaching strategies contained in the Learning-Focused Strategies Model (LFSM) Program were researched in this study. The LFSM Program provided a framework for comprehensive school improvement to those schools that implemented the program. The LFSM Program provided schools with consistent training in the utilization of exemplary practices and instruction. A high school located in the suburbs of Atlanta, Georgia was the focus of this investigation. Twelve high school science classrooms participated in the study: six biology and six physical science classes. Up-to-date research discovered that the strategies contained in the LFSM Program were research-based and highly effective for elementary and middle school instruction. Research on its effectiveness in high school instruction was the main focus of this study. This investigation utilized a mixed methods approach, in which data were examined qualitatively and quantitatively. Common District Assessment (CDA) quantitative data were collected and compared between those science classrooms that utilized LFS and those using traditional instructional strategies. Qualitative data were generated through classroom observations, student surveys, and teacher interviews. Individual data points were triangulated to determine trends of information reflecting the effects of implementing LFS. Based on the data collected in the research study, classrooms utilizing LFS were more successful academically than the classrooms using traditional instructional methods. Derived from the quantitative data, students in LFS classrooms were more proficient on both the biology and physical science Unit 1 CDAs, illustrating the effectiveness of LFS in the science classroom. Key terms

  12. Quantum Biology

    Directory of Open Access Journals (Sweden)

    Alessandro Sergi

    2009-06-01

    Full Text Available A critical assessment of the recent developmentsof molecular biology is presented.The thesis that they do not lead to a conceptualunderstanding of life and biological systems is defended.Maturana and Varela's concept of autopoiesis is briefly sketchedand its logical circularity avoided by postulatingthe existence of underlying living processes,entailing amplification from the microscopic to the macroscopic scale,with increasing complexity in the passage from one scale to the other.Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces,is criticized. It is suggested that the correct interpretationof quantum dispersion forces (van der Waals, hydrogen bonding, and so onas quantum coherence effects hints at the necessity of includinglong-ranged forces (or mechanisms for them incondensed matter theories of biological processes.Some quantum effects in biology are reviewedand quantum mechanics is acknowledged as conceptually important to biology since withoutit most (if not all of the biological structuresand signalling processes would not even exist. Moreover, it is suggested that long-rangequantum coherent dynamics, including electron polarization,may be invoked to explain signal amplificationprocess in biological systems in general.

  13. Quantum Biology

    CERN Document Server

    Sergi, Alessandro

    2009-01-01

    A critical assessment of the recent developments of molecular biology is presented. The thesis that they do not lead to a conceptual understanding of life and biological systems is defended. Maturana and Varela's concept of autopoiesis is briefly sketched and its logical circularity avoided by postulating the existence of underlying {\\it living processes}, entailing amplification from the microscopic to the macroscopic scale, with increasing complexity in the passage from one scale to the other. Following such a line of thought, the currently accepted model of condensed matter, which is based on electrostatics and short-ranged forces, is criticized. It is suggested that the correct interpretation of quantum dispersion forces (van der Waals, hydrogen bonding, and so on) as quantum coherence effects hints at the necessity of including long-ranged forces (or mechanisms for them) in condensed matter theories of biological processes. Some quantum effects in biology are reviewed and quantum mechanics is acknowledge...

  14. Action spectra affect variability of the climatology of biologically effective ultraviolet radiation on cloud-free days

    International Nuclear Information System (INIS)

    Action spectrum (AS) describes the relative effectiveness of ultraviolet (UV) radiation in producing biological effects and allows spectral UV irradiance to be weighted in order to compute biologically effective UV radiation (UVBE). The aim of this research was to study the seasonal and latitudinal distribution over Europe of daily UVBE doses responsible for various biological effects on humans and plants. Clear sky UV radiation spectra were computed at 30-min time intervals for the first day of each month of the year for Rome, Potsdam and Trondheim using a radiative transfer model fed with climatological data. Spectral data were weighted using AS for erythema, vitamin D synthesis, cataract and photo-keratitis for humans, while the generalised plant damage and the plant damage AS were used for plants. The daily UVBE doses for the above-mentioned biological processes were computed and are analysed in this study. The patterns of variation due to season (for each location) and latitude (for each date) resulted as being specific for each adopted AS. The biological implications of these results are briefly discussed highlighting the importance of a specific UVBE climatology for each biological process. (authors)

  15. Calcium effect on the metabolic pathway of phosphorus accumulating organisms in enhanced biological phosphorus removal systems.

    Science.gov (United States)

    Zhang, Hai-Ling; Sheng, Guo-Ping; Fang, Wei; Wang, Yong-Peng; Fang, Cai-Yun; Shao, Li-Min; Yu, Han-Qing

    2015-11-01

    Phosphorus accumulating organisms (PAOs) have been found to act as glycogen-accumulating organisms (GAOs) under certain conditions, thus, the deterioration in the performance of enhanced biological phosphorus removal systems is not always attributed to the proliferation of GAOs. In this work, the effects of calcium on the metabolic pathway of PAOs were explored. It was found that when the influent Ca(2+) concentration was elevated, the tendency and extent of extracellular calcium phosphate precipitation increased, and the intracellular inert Ca-bound polyphosphate was synthesized, while the microbial population remained almost unchanged. The changes in the ratios of phosphorus released/acetate uptaken, the glycogen degraded/acetate uptaken and the poly-β-hydroxyalkanoates synthesized/acetate uptaken during the anaerobic period confirm that, as the influent Ca(2+) concentration was increased, the polyphosphate-accumulating metabolism was partially shifted to the glycogen-accumulating metabolism. At an influent Ca(2+) around 50 mg/L, in addition to the extracellular calcium phosphate precipitation, the intracellular inert Ca-bound polyphosphate synthesis might also be involved in the metabolic change of PAOs. The results of the present work would be beneficial to better understand the biochemical metabolism of PAOs in enhanced biological phosphorus removal systems. PMID:26233656

  16. Effects of idle time on biological phosphorus removal by sequencing batch reactors.

    Science.gov (United States)

    Gao, Dawen; Yin, Hang; Liu, Lin; Li, Xing; Liang, Hong

    2013-12-01

    Three identical sequencing batch reactors (SBRs) were operated to investigate the effects of various idle times on the biological phosphorus (P) removal. The idle times were set to 3 hr (R1), 10 hr (R2) and 17 hr (R3). The results showed that the idle time of a SBR had potential impact on biological phosphorus removal, especially when the influent phosphorus concentration increased. The phosphorus removal efficiencies of the R2 and R3 systems declined dramatically compared with the stable R1 system, and the P-release and P-uptake rates of the R3 system in particular decreased dramatically. The PCR-DGGE analysis showed that uncultured Pseudomonas sp. (GQ183242.1) and beta-Proteobacteria (AY823971) were the dominant phosphorus removal bacteria for the R1 and R2 systems, while uncultured gamma-Proteobacteria were the dominant phosphorus removal bacteria for the R3 system. Glycogen-accumulating organisms (GAOs), such as uncultured Sphingomonas sp. (AM889077), were found in the R2 and R3 systems. Overall, the R1 system was the most stable and exhibited the best phosphorus removal efficiency. It was found that although the idle time can be prolonged to allow the formation of intracellular polymers when the phosphorus concentration of the influent is low, systems with a long idle time can become unstable when the influent phosphorus concentration is increased. PMID:24649669

  17. Effective use of Latent Semantic Indexing and Computational Linguistics in Biological and Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Hongyu eChen

    2013-01-01

    Full Text Available Text mining is rapidly becoming an essential technique for the annotation and analysis of large biological data sets. Biomedical literature currently increases at a rate of several thousand papers per week, making automated information retrieval methods the only feasible method of managing this expanding corpus. With the increasing prevalence of open-access journals and constant growth of publicly-available repositories of biomedical literature, literature mining has become much more effective with respect to the extraction of biomedically-relevant data. In recent years, text mining of popular databases such as MEDLINE has evolved from basic term-searches to more sophisticated natural language processing techniques, indexing and retrieval methods, structural analysis and integration of literature with associated metadata. In this review, we will focus on Latent Semantic Indexing (LSI, a computational linguistics technique increasingly used for a variety of biological purposes. It is noted for its ability to consistently outperform benchmark Boolean text searches and co-occurrence models at information retrieval and its power to extract indirect relationships within a data set. LSI has been used successfully to formulate new hypotheses, generate novel connections from existing data, and validate empirical data.

  18. Biologically inspired hexapedal robot using field-effect electroactive elastomer artificial muscles

    Science.gov (United States)

    Eckerle, Joseph; Stanford, Scott; Marlow, John; Schmidt, Roger; Oh, Seajin; Low, Thomas; Shastri, Subramanian V.

    2001-06-01

    Small, autonomous mobile robots are needed for applications such as reconnaissance over difficult terrain or internal inspection of large industrial systems. Previous work in experimental biology and with legged robots has revealed the advantages of using leg actuators with inherent compliance for robust, autonomous locomotion over uneven terrain. Recently developed field-effect electroactive elastomer artificial muscle actuators offer such compliance as well as attractive performance parameters such as force/weight and efficiency, so we developed a small (670 g) six-legged robot, FLEX, using AM actuators. Electrically, AM actuators are a capacitive, high-impedance load similar to piezoelectrics, which makes them difficult to rive optimally with conventional circuitry. Still, we were able to devise a modular, microprocessor-based control system capable of driving 12 muscles with up to 5,000 V, operating form an on- board battery. The artificial muscle actuators had excellent compliance and peak performance, but suffered from poor uniformity and degradation over time. FLEX is the first robot of its kind. While there is room for improvement in some of the robot systems such as actuators and their drivers, this work has validated the idea of using artificial muscle actuators in biologically inspired walking robots.

  19. Effect of pea intercropping on biological efficiencies and economics of some non-legume winter vegetables

    International Nuclear Information System (INIS)

    Intercropping with legumes makes effective use of land and other resources and results in reduced cost of production. Increased agricultural production through intercropping with minimal cost is need of time to feed increasing population. The reported work evaluates the biological efficiencies and economics of pea, garlic, turnip and cauliflower grown as sole crops and when pea intercropped in garlic, turnip and cauliflower during 2010-12. All the vegetables generally yielded more when grown as single crop compared with when pea was intercropped in these vegetables. In peas in garlic intercropping, pea yield was not significantly affected; however, garlic yield was significantly reduced (65.8%). Pea intercropping in turnip or cauliflower resulted in significantly lower yields of both crops (29.1 and 28.0%, respectively) as compared with their sole cropping. All other characteristics (plant growth and yield components) of all the four crops which indicate biological efficiency generally were greater when grown as single crops and decreased in intercropping combinations. Analysis of intercropping treatments revealed that pea intercropping in turnip resulted in the highest marginal rate of return (8,875%), followed by pea intercropping in cauliflower (6,977%), due to lower input costs incurred per hectare. However, net benefit to the growers was higher (Rs. 327,925) in case of pea intercropping in cauliflower, followed by pea intercropping in garlic (Rs. 213,425). (author)

  20. Biological effects of low energy nitrogen ion implantation on Jatropha curcas L. seed germination

    Science.gov (United States)

    Xu, Gang; Wang, Xiao-teng; Gan, Cai-ling; Fang, Yan-qiong; Zhang, Meng

    2012-09-01

    To explore the biological effects of nitrogen ion beam implantation on dry Jatropha curcas seed, a beam of N+ with energy of 25 keV was applied to treat the dry seed at six different doses. N+ beam implantation greatly decreased germination rate and seedling survival rate. The doses within the range of 12 × 1016 to 15 × 1016 ions cm-2 severely damaged the seeds: total antioxidant capacity (TAC), germination rate, seedling survival rate, reduced ascorbate acid (HAsA) and reduced glutathione (GSH) contents, and most of the tested antioxidases activity (i.e. catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD)) reached their lowest levels. At a dose of 18 × 1016 ion cm-2, biological repair took place: moderate increases were found in TAC, germination rate, seedling survival rate, HAsA and GSH contents, and some antioxidant enzyme activities (i.e. CAT, APX, SOD and GPX). The dose of 18 × 1016 ions cm-2 may be the optimum dose for use in dry J. curcas seed mutation breeding. CAT, HAsA and GSH contributed to the increase of TAC, but CAT was the most important. POD performed its important role as seed was severely damaged. The main role of the HAsA-GSH cycle appeared to be for regeneration of HAsA.

  1. Investigation of human exposure to triclocarban after showering and preliminary evaluation of its biological effects.

    Science.gov (United States)

    Schebb, Nils Helge; Inceoglu, Bora; Ahn, Ki Chang; Morisseau, Christophe; Gee, Shirley J; Hammock, Bruce D

    2011-04-01

    The antibacterial soap additive triclocarban (TCC) is widely used in personal care products. TCC has a high environmental persistence. We developed and validated a sensitive online solid-phase extraction-LC-MS/MS method to rapidly analyze TCC and its major metabolites in urine and other biological samples to assess human exposure. We measured human urine concentrations 0-72 h after showering with a commercial bar soap containing 0.6% TCC. The major route of renal elimination was excretion as N-glucuronides. The absorption was estimated at 0.6% of the 70±15 mg of TCC in the soap used. The TCC-N-glucuronide urine concentration varied widely among the subjects, and continuous daily use of the soap led to steady state levels of excretion. In order to assess potential biological effects arising from this exposure, we screened TCC for the inhibition of human enzymes in vitro. We demonstrate that TCC is a potent inhibitor of the enzyme soluble epoxide hydrolase (sEH), whereas TCC's major metabolites lack strong inhibitory activity. Topical administration of TCC at similar levels to rats in a preliminary in vivo study, however, failed to alter plasma biomarkers of sEH activity. Overall the analytical strategy described here revealed that use of TCC soap causes exposure levels that warrant further evaluation. PMID:21381656

  2. Effects of interlinker sequences on the biological properties of bispecific single-chain antibodies

    Institute of Scientific and Technical Information of China (English)

    FANG Min; JIANG Xin; YANG Zhi; YIN Changcheng; LI Hua; ZHAO Rui; ZHANG Zhong; LIN Qing; HUANG Hualiang

    2003-01-01

    Single-chain bispecific antibody (scBsAb) is one of the promising genetic engineering antibody formats for clinical application. But the effects of interlinker sequences on the biological properties of bispecific single-chain antibodies have not been studied in detail. Three interlinker sequences were designed and synthesized, and denominated as Fc, HSA, 205C′, respectively. Universal vectors with these different interlinker sequences for scBsAb expression in E. coli were constructed. A model scBsAb based on a reshaped single-chain antibody (scFv) against human CD3 and a scFv directed against human ovarian carcinoma were generated and expressed in E. coli. The results of SDS-PAGE and Western blot showed that the different interlinker sequences did not affect the expression levelof scBsAb. However, as demonstrated by ELISA and pharmacokinetics studies performed in mice, scBsAbs with different interlinker sequences had difference in the antigen-binding activities and terminal half-life time (T1/2β) in vivo, the interlinker HSA could remarkably prolong the retention time of scBsAb in blood. These results indicated that the peptide sequence of interlinker could affect important biological properties of scBsAb, such as antigen-binding properties and stability in vivo. So, selection of an appropriate interlinker sequence is very important for scBsAb construction. Optimal interlinker can bring scBsAb biologicalproperties more suitable for clinical application.

  3. Comparison of breast sequential and simultaneous integrated boost using the biologically effective dose volume histogram (BEDVH)

    International Nuclear Information System (INIS)

    A method is presented to radiobiologically compare sequential (SEQ) and simultaneously integrated boost (SIB) breast radiotherapy. The method is based on identically prescribed biologically effective dose (iso-BED) which was achieved by different prescribed doses due to different fractionation schemes. It is performed by converting the calculated three-dimensional dose distribution to the corresponding BED distribution taking into consideration the different number of fractions for generic α/β ratios. A cumulative BED volume histogram (BEDVH) is then derived from the BED distribution and is compared for the two delivery schemes. Ten breast cancer patients (4 right-sided and 6 left-sided) were investigated. Two tangential intensity modulated whole breast beams with two other oblique (with different gantry angles) beams for the boost volume were used. The boost and the breast target volumes with either α/β = 10 or 3 Gy, and ipsi-lateral and contra-lateral lungs, heart, and contra-lateral breast as organs at risk (OARs) with α/β = 3 Gy were compared. Based on the BEDVH comparisons, the use of SIB reduced the biological breast mean dose by about 3 %, the ipsi-lateral lung and heart by about 10 %, and contra-lateral breast and lung by about 7 %. BED based comparisons should always be used in comparing plans that have different fraction sizes. SIB schemes are dosimetrically more advantageous than SEQ in breast target volume and OARs for equal prescribed BEDs for breast and boost

  4. Biological sulfate removal from construction and demolition debris leachate: Effect of bioreactor configuration

    International Nuclear Information System (INIS)

    Highlights: • Novel biological technique for gypsum removal from CDD. • CDDS leachate treatment performed using different sulfate reducing bioreactors. • Gypsum in CDD can be used as a source of sulfate for sulfate reducing bacteria. • High calcium concentration (1000 mg L−1) did not affect the bioreactor performance. - Abstract: Due to the contamination of construction and demolition debris (CDD) by gypsum drywall, especially, its sand fraction (CDD sand, CDDS), the sulfate content in CDDS exceeds the posed limit of the maximum amount of sulfate present in building sand (1.73 g sulfate per kg of sand for the Netherlands). Therefore, the CDDS cannot be reused for construction. The CDDS has to be washed in order to remove most of the impurities and to obtain the right sulfate content, thus generating a leachate, containing high sulfate and calcium concentrations. This study aimed at developing a biological sulfate reduction system for CDDS leachate treatment and compared three different reactor configurations for the sulfate reduction step: the upflow anaerobic sludge blanket (UASB) reactor, inverse fluidized bed (IFB) reactor and gas lift anaerobic membrane bioreactor (GL-AnMBR). This investigation demonstrated that all three systems can be applied for the treatment of CDDS leachate. The highest sulfate removal efficiency of 75–85% was achieved at a hydraulic retention time (HRT) of 15.5 h. A high calcium concentration up to 1000 mg L−1 did not give any adverse effect on the sulfate removal efficiency of the IFB and GL-AnMBR systems

  5. 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. PMID:24742665

  6. Biological effects of clustered DNA damage produced by heavy ion beams with its complexity

    International Nuclear Information System (INIS)

    Heavy ion beams produce denser ionized region around their track, and cause accumulated damage cluster in the target DNA molecule, termed ''clustered DNA damage.'' Although any ionizing radiations can generate clustered DNA damage with respective degree, heavy ion beam might very effectively produce clustered DNA damage for a reason as mentioned thereinbefore. However, we have less knowledge about molecular mechanism how clustered DNA damage is involved in the degree of biological consequence, and relationship between the species of ionizing radiation and the result. Our previous in vitro study showed that the yields of clustered DNA damage in the target DNA was in inverse proportion to the linear energy transfer (LET) of irradiated radiation (J. Radiat. Res., 49; 133-146, 2008). This result suggests that the yield is not simply responsible to the biological consequence. Therefore, we focused on the structure of clustered DNA damage induced by heavy ion beams in this study. We evaluated the number of damaged site in the designed target oligonucleotides irradiated by gamma-rays, carbon ions and iron ions beams. Also, we estimated the intracellular yields of clustered DNA damage consisted of oxidative base lesions (clustered base damage), because we investigated only DSB not clustered base damage in the previous study. (author)

  7. Effects of addictive substances during pregnancy and infancy and their analysis in biological materials.

    Science.gov (United States)

    Płotka, Justyna; Narkowicz, Sylwia; Polkowska, Zaneta; Biziuk, Marek; Namieśnik, Jacek

    2014-01-01

    The use of addictive substances during pregnancy is a serious social problem, not only because of effects on the health of the woman and child, but also because drug or alcohol dependency detracts from child care and enhances the prospect of child neglect and family breakdown. Developing additive substance abuse treatment programs for pregnant women is socially important and can help ensure the health of babies, prevent subsequent developmental and behavioral problems (i.e., from intake of alcohol or other additive substances such as methamphetamine, cocaine,or heroine) and can reduce addiction costs to society. Because women of childbearing age often abuse controlled substances during their pregnancy, it is important to undertake biomonitoring of these substances in biological samples taken from the pregnant or nursing mother (e.g., blood, urine,hair, breast milk, sweat, oral fluids, etc.), from the fetus and newborn (e.g., meconium,cord blood, neonatal hair and urine) and from both the mother and fetus (i.e.,amniotic fluids and placenta). The choice of specimens to be analyzed is determined by many factors; however, the most important is knowledge of the chemical and physical characteristics of a substance and the route of it administration. Maternal and neonatal biological materials reflect exposures that occur over a specific time period, and each of these biological specimens has different advantages and disadvantages,in terms of accuracy, time window of exposure and cost/benefit ratio.Sampling the placenta may be the most important biomonitoring choice for assessing in utero exposure to addictive substances. The use of the placenta in scientific research causes a minimum of ethical problems, partly because its sampling is noninvasive, causes no harm to mother or child, and partly because, in any case,placentas are discarded and incinerated after birth. Such samples, when properly analyzed, may provide key essential information about fetal exposure to toxic

  8. Final report on 'biological effects of tritium as a basis of research and development in nuclear fusion'

    International Nuclear Information System (INIS)

    The National Institute of Radiological Sciences, Japan, has undertaken a special study of ''biological effects of tritium as a basis of research and development in nuclear fusion'' over a 5-year period from April 1981 through March 1986. This is a final report, covering incorporation and metabolism of tritium, physical, chemical, and cellular effects of tritium, tritium damage to the mammalian tissue, and human exposure to tritium. The report is organized into five chapters, including ''Study of incorporation of tritium into the living body and its in vivo behavior''; ''Physical and chemical studies for the determination of relative biological effectiveness''; ''Analytical study on biological effects of tritium in cultured mammalian cells''; ''Study of tritium effects on the mammalian tissue, germ cells, and cell transformation''; and ''Changes in the hemopoietic stem cells and lymphocyte subsets in humans after exposure to some internal emitters''. (Namekawa, K.)

  9. Improved biological properties and hypouricemic effects of uricase from Candida utilis loaded in novel alkaline enzymosomes

    Directory of Open Access Journals (Sweden)

    Tan QY

    2012-07-01

    Full Text Available Qun-You Tan,1,* Jing-Qing Zhang,2,* Na Wang,3,* Hong Yang,4 Xiaoling Li,5 Hua-Rong Xiong,2 Jian-Yong Wu,2 Chun-Jing Zhao,3 Hong Wang,2 Hua-Feng Yin2 1Department of Thoracic Surgery, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, 2Medicine Engineering Research Center, Chongqing Key Laboratory of Biochemical & Molecular Pharmacology, Chongqing Medical University, Chongqing, 3School of Pharmacy, Second Affiliated Hospital, Chongqing Medical University, Chongqing, 4School of Pharmacy, Medical College of Soochow University, Soochow, People's Republic of China; 5TJ Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, CA, USA*These authors contributed equally to this workObjective: Previous studies on various enzymosomes (functional lipid vesicles encapsulating an enzyme have been mostly carried out in vitro and have focused on preserving catalytic activity and improving the stability of the enzyme. Until now, few studies have focused on their in vivo fate. Similarly, although we have previously reported the increased in vitro uricolytic activity (about 2.2 times higher than that of free uricase, or three times higher than that of PEGylated uricase, Puricase®, under physiological pH and temperature and improved stability of the novel alkaline enzymosomes (functional lipid vesicles encapsulating uricase from Candida utilis: uricase-containing lipid vesicles, UOXLVs, it is still necessary to study the biological properties and hypouricemic effects of UOXLVs in vivo.Methods: The enzyme kinetics, pharmacokinetics, pharmacodynamics, immunogenicity, and preliminary safety of UOXLVs were evaluated.Results: The Michaelis constant (Km value of the UOXLVs was slightly lower than that of the free enzyme. The enzyme release from the UOXLVs lasted over 12 hours and their circulation half-life was about sevenfold longer than that of the free uricase. Meanwhile, the UOXLVs had a 22-fold

  10. Relative Biological Effectiveness of Fast Neutrons for Late Somatic Effects in Mice

    International Nuclear Information System (INIS)

    Female RF mice were exposed to whole-body 250 kVp X-rays, Co60 γ-rays, and fast neutrons from a cyclotron (∼1 MeV mean energy) and a Po-Be source (∼5 MeV mean energy), beginning at ten weeks of age. Doses of <1.0 to <5000 rad were accumulated at dose rates ranging from ∼100 rad /min to less than 0.00007 rad/min (0.1 rad/23 h), and the resulting effects on survival and on the incidence of various diseases (neoplasms, lens opacities, senile and other degenerative changes) were recorded. The life expectancy of 30-d survivors was shortened ∼0.83 d /rad of fast neutrons, irrespective of the dose rate, whereas the life-shortening effectiveness of X-rays and γ-rays was ∼0.24 d/rad at the highest dose rate and only ∼0.10 d/rad at the lowest dose rate. The effectiveness of y-rays was similarly dependent on dose rate for other late somatic effects; hence the RBE of fast neutrons generally increased with decreasing dose rate for these effects. Only in cataract - induction did the RBE exceed 10. In the induction of ovarian tumours, it was unusually low, i.e. less than 1.0. Our results imply that ''multi-hit'' radiobiological events are important in the pathogenesis of most late effects of radiation and that protection guides for human exposure to radiation must be interpreted in the light of time-intensity variations in the effectiveness of X-rays and y-rays. (author)

  11. Effect of the flavonoid rutin on the biology of Spodoptera frugiperda (Lepidoptera: Noctuidae)

    OpenAIRE

    Talita Roberta Ferreira Borges Silva; André Cirilo de Sousa Almeida; Tony de Lima Moura; Anderson Rodrigo da Silva; Silvia de Sousa Freitas; Flávio Gonçalves de Jesus

    2016-01-01

    The fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is a major pest of maize crops in Brazil. The effects of plant metabolites on the biology and behavior of insects is little studied. The aim of the study was to evaluate the activity of rutin on the biology of the S. frugiperda by using artificial diets containing rutin. The study evaluated four treatments: regular diet (control group) and diets containing 1.0, 2.0 and 3.0 mg g-1 of rutin. The following biological v...

  12. The Effect of Knowledge Linking Levels in Biology Lessons upon Students' Knowledge Structure

    Science.gov (United States)

    Wadouh, Julia; Liu, Ning; Sandmann, Angela; Neuhaus, Birgit J.

    2014-01-01

    Knowledge structure is an important aspect for defining students' competency in biology learning, but how knowledge structure is influenced by the teaching process in naturalistic biology classroom settings has scarcely been empirically investigated. In this study, 49 biology lessons in the teaching unit "blood and circulatory…

  13. Anthropogenic Noise and its Effect on Animal Communication: An Interface Between Comparative Psychology and Conservation Biology

    OpenAIRE

    Rabin, Lawrence A.; McCowan, Brenda; Hooper, Stacie L.; Owings, Donald H

    2003-01-01

    Conservation biology and comparative psychology rarely intersect, in part because conservation biology typically emphasizes populations whereas comparative psychology concentrates on individual organisms. However, both fields could benefit from their integration. Conservation biology can profit from an enhanced understanding of individual-level impacts of habitat alteration and the resulting implications for conservation mitigation strategies. Comparative psychology can gain from increased at...

  14. Assessment of the Effects of Student Response Systems on Student Learning and Attitudes over a Broad Range of Biology Courses

    OpenAIRE

    Preszler, Ralph W.; Dawe, Angus; Shuster, Charles B.; Shuster, Michèle

    2007-01-01

    With the advent of wireless technology, new tools are available that are intended to enhance students' learning and attitudes. To assess the effectiveness of wireless student response systems in the biology curriculum at New Mexico State University, a combined study of student attitudes and performance was undertaken. A survey of students in six biology courses showed that strong majorities of students had favorable overall impressions of the use of student response systems and also thought t...

  15. Quality of Early Family Relationships and the Timing and Tempo of Puberty: Effects Depend on Biological Sensitivity to Context

    OpenAIRE

    Ellis, Bruce J.; Shirtcliff, Elizabeth A.; Boyce, W. Thomas; Deardorff, Julianna; Essex, Marilyn J.

    2011-01-01

    Guided by evolutionary-developmental theories of biological sensitivity to context and reproductive development, the current research examined the interactive effects of early family environments and psychobiologic reactivity to stress on the subsequent timing and tempo of puberty. As predicted by the theory, among children displaying heightened biological sensitivity to context (i.e., higher stress reactivity), higher quality parent-child relationships forecast slower initial pubertal tempo ...

  16. Radon as a medicine. Therapeutic effectiveness, biological mechanism and comparative risk assessment

    International Nuclear Information System (INIS)

    Proofs of the therapeutic efficiency of balneological radon applications administered to patients suffering from rheumatic diseases, investigations into the biological action mechanism associated with the alpha particles emitted by radon and its radioactive daughter products, and the comparative risk assessment of radon treatment and medicinal pain therapy have been the research projects whose results are summarized in this book. Controlled clinical studies, if possible performed as prospective, randomized and placebo-controlled double blind studies, have given evidence that the therapeutic effects of balneological radon applications - long-lasting pain reduction and reduced consumption of medicines compared with controls - are significantly persisting over many post-treatment months. The molecular and cellular mechanism of action underlying these long-lasting therapeutic effects has been identified as the down-regulation of cellular immune responses, initiated by cellular apoptosis sequential to low alpha particle doses and by the subsequent release of anti-inflammatory cytokines. The unwanted side-effects of non-steroidal anti-rheumatic drug treatments have to be compared with the absence of side effects from the balneological radon applications which merely involve radiation doses well below the mean value and the fluctuation width of the annual doses attributable to everybody's natural radiation exposure.

  17. International and National Expert Group Evaluations: Biological/Health Effects of Radiofrequency Fields

    Directory of Open Access Journals (Sweden)

    Vijayalaxmi

    2014-09-01

    Full Text Available The escalated use of various wireless communication devices, which emit non-ionizing radiofrequency (RF fields, have raised concerns among the general public regarding the potential adverse effects on human health. During the last six decades, researchers have used different parameters to investigate the effects of in vitro and in vivo exposures of animals and humans or their cells to RF fields. Data reported in peer-reviewed scientific publications were contradictory: some indicated effects while others did not. International organizations have considered all of these data as well as the observations reported in human epidemiological investigations to set-up the guidelines or standards (based on the quality of published studies and the “weight of scientific evidence” approach for RF exposures in occupationally exposed individuals and the general public. Scientists with relevant expertise in various countries have also considered the published data to provide the required scientific information for policy-makers to develop and disseminate authoritative health information to the general public regarding RF exposures. This paper is a compilation of the conclusions, on the biological effects of RF exposures, from various national and international expert groups, based on their analyses. In general, the expert groups suggested a reduction in exposure levels, precautionary approach, and further research.

  18. Radon as a medicine. Therapeutic effectiveness, biological mechanism and comparative risk assessment

    Energy Technology Data Exchange (ETDEWEB)

    Deetjen, Peter; Falkenbach, Albrecht; Harder, Dietrich; Joeckel, Hans; Kaul, Alexander; Philipsborn, Henning von

    2014-07-01

    Proofs of the therapeutic efficiency of balneological radon applications administered to patients suffering from rheumatic diseases, investigations into the biological action mechanism associated with the alpha particles emitted by radon and its radioactive daughter products, and the comparative risk assessment of radon treatment and medicinal pain therapy have been the research projects whose results are summarized in this book. Controlled clinical studies, if possible performed as prospective, randomized and placebo-controlled double blind studies, have given evidence that the therapeutic effects of balneological radon applications - long-lasting pain reduction and reduced consumption of medicines compared with controls - are significantly persisting over many post-treatment months. The molecular and cellular mechanism of action underlying these long-lasting therapeutic effects has been identified as the down-regulation of cellular immune responses, initiated by cellular apoptosis sequential to low alpha particle doses and by the subsequent release of anti-inflammatory cytokines. The unwanted side-effects of non-steroidal anti-rheumatic drug treatments have to be compared with the absence of side effects from the balneological radon applications which merely involve radiation doses well below the mean value and the fluctuation width of the annual doses attributable to everybody's natural radiation exposure.

  19. An overview of the safety and biological effects of Bacillus thuringiensis Cry toxins in mammals.

    Science.gov (United States)

    Rubio-Infante, Néstor; Moreno-Fierros, Leticia

    2016-05-01

    Crystal proteins (Cry) produced during the growth and sporulation phases of Bacillus thuringiensis (Bt) bacterium are known as delta endotoxins. These toxins are being used worldwide as bioinsecticides to control pests in agriculture, and some Cry toxins are used against mosquitoes to control vector transmission. This review summarizes the relevant information currently available regarding the biosafety and biological effects that Bt and its insecticidal Cry proteins elicit in mammals. This work was performed because of concerns regarding the possible health impact of Cry toxins on vertebrates, particularly because Bt toxins might be associated with immune-activating or allergic responses. The controversial data published to date are discussed in this review considering earlier toxicological studies of B. thuringiensis, spores, toxins and Bt crops. We discussed the experimental studies performed in humans, mice, rats and sheep as well as in diverse mammalian cell lines. Although the term 'toxic' is not appropriate for defining the effects these toxins have on mammals, they cannot be considered innocuous, as they have some physiological effects that may become pathological; thus, trials that are more comprehensive are necessary to determine their effects on mammals because knowledge in this field remains limited. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26537666

  20. Biological UV-doses and the effect on an ozone layer depletion

    International Nuclear Information System (INIS)

    Effective UV-doses were calculated based on the integrated product of the biological action spectrum and the solar radiation. The calculations included absorption and scattering of UV-radiation in the atmosphere, both for normal ozone conditions as well as for a depleted ozone layer. The effective annual UV-dose increases by approximately 4% per degree of latitude towards the equator. An ozone depletion of 1% increases the annual UV-dose by approximately 1% at 60o N. A large depletion of 50% over Scandinavia (60o N) would give this region an effective UV-dose similar to that obtained, with normal ozone conditions, at a latitude of 40o N (California or the Mediterranean countries). The Antarctic ozone hole increases the annual UV-dose by 20 to 25% which is a similar increase as that attained by moving 5 to 6 degrees of latitude nearer the equator. The annual UV-dose on higher latitudes is mainly determined by the summer values of ozone. Both the ozone values and the effective UV-doses vary from one year to another (within ±4%). No positive or negative trend is observed for Scandinavia from 1978 to 1988