WorldWideScience

Sample records for sublethal irradiation pretreatment

  1. Functional modifications of macrophage activity after sublethal irradiation. [Toxoplasma gondii

    Energy Technology Data Exchange (ETDEWEB)

    Swartz, R.P.

    1982-01-01

    The modifications of macrophage activity following sublethal irradiation, both in vivo and in vitro, were studied using spreading and C3b-receptor-mediated ingestion assays. Nonelicited peritoneal washout cells were examined for changes in activity and selected population characteristics. The cells from irradiated mice were from a resident peritoneal population and not immigrating cells. The macrophage population showed enhanced activity early with a refractory period (24-48) when the macrophages were unresponsive to stimulation by irradiated lymphocytes. The enhanced activity was inversely dose dependent on macrophage. The lymphocytes showed a regulatory function(s) on the time post irradiation at which they were examined. Early lymphocytes exhibited the ability to enhance the activity of normal macrophages while lymphocytes removed 24 hours post irradiation could suppress the activity of already activated macrophages. The effect(s) of the various lymphocyte populations were reproduced with cell-free supernatants which was indicative of the production of lymphokines. Separation on nylon wool columns indicated that the activity resided primarily in the T-cell population of lymphocytes. In vitro irradiation indicated that stimulation of the lymphocytes is macrophage dependent. Additional work indicated that sublethally irradiated macrophages did not inhibit replication of the coccidian protozoon Toxoplasma gondii although they did show increased phagocytosis. Examination of the serum from whole body irradiated mice showed the presence of a postirradiation substance which enhanced the phagocytosis of normal macrophages. It was not present in the serum of normal mice and was not endotoxin.

  2. Irradiation pretreatment for coal desulfurization

    Science.gov (United States)

    Hsu, G. C.

    1979-01-01

    Process using highly-penetrating nuclear radiation (Beta and Gamma radiation) from nuclear power plant radioactive waste to irradiate coal prior to conventional desulfurization procedures increases total extraction of sulfur.

  3. Avoidance behaviour and anxiety in rats irradiated with a sublethal dose of gamma-rays.

    Science.gov (United States)

    Tomášová, Lenka; Smajda, B; Bona, M

    2011-12-01

    The aim of this study was to assess, whether a sublethal dose of gamma-rays will influence the avoidance behaviour and anxiety in rats and whether the response to radiation depends on time of day of its application. Adult male Wistar rats were tested in elevated plus-maze, in hot plate test and in the light/dark box in 4 regular intervals during a day. After two weeks the animals were irradiated with a whole-body dose 6 Gy of gamma-rays. One day after irradiation the animals were repeatedly tested in the same way, as before irradiation. In the plus-maze test an increased level of anxiety was established. The irradiation significantly decreased the locomotor activity of rats, but the extent of exploratory and comfortable behaviour were not altered. After irradiation, an elevated aversion to the thermal stimulus was observed in the hot plate test. The effects of radiation were more pronounced in the light period of the day, than in the dark one. No significant differences in aversion to light were detected after irradiation. The obtained results indicate, that sublethal doses of ionizing radiation can markedly influence the reactivity of animals to adverse stimuli, their motoric activity and emotional status, as well.

  4. Enhancement of committed hematopoietic stem cell colony formation by nandrolone decanoate after sublethal whole body irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Gallicchio, V.S.; Chen, M.G.; Watts, T.D.

    1984-11-01

    The ability of an anabolic steroid, nandrolone decanoate, to increase committed topoietic stem cell (CFU-gm, CFU-e, and BFU-e) colony formation after sublethal irradiation was evaluated. Immediately after receiving whole body irradiation and on the next two days, each mouse was injected intraperitoneally with nandrolone decanoate (1.25 mg) in propylene glycol. Irradiated control mice received only propylene glycol. Compared to controls, drug-treated mice showed marked peripheral blood leukocytosis and more stable packed red cell volume. Drug-treated mice also demonstrated increased erythropoiesis, as CFU-e/BFU-e concentrations from both marrow (9% to 581%) and spleen (15% to 797%) were elevated. Granulopoiesis was increased similarly, as CFU-gm concentrations from marrow (38% to 685%) and spleen (9% to 373%) were elevated. These results demonstrate that nandrolone decanoate enhances hematopoietic stem cell recovery after sublethal whole body irradiation. This suggests that following hematopoietic suppression, nandrolone decanoate may stimulate the recovery of hematopoiesis at the stem cell level and in peripheral blood.

  5. Sublethal gamma irradiation affects reproductive impairment and elevates antioxidant enzyme and DNA repair activities in the monogonont rotifer Brachionus koreanus

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jeonghoon; Won, Eun-Ji [Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Kim, Il-Chan; Yim, Joung Han [Division of Life Sciences, Korea Polar Research Institute, Incheon 406-840 (Korea, Republic of); Lee, Su-Jae [Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 133-791 (Korea, Republic of); Lee, Jae-Seong, E-mail: jslee2@skku.edu [Department of Biological Sciences, College of Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of)

    2014-10-15

    Highlights: • No mortality within 96 h even at a high intensity (1200 Gy). • A reduced fecundity of Brachionus koreanus at over 150 Gy with a decrease in lifespan. • Dose-dependent ROS increase with GST enzyme activity at sub-lethal doses. • Significant impact on life table parameters, particularly fecundity. • Significant up-regulation of DNA repair-associated genes at sublethal doses. - Abstract: To examine the effects of gamma radiation on marine organisms, we irradiated several doses of gamma ray to the microzooplankton Brachionus koreanus, and measured in vivo and in vitro endpoints including the survival rate, lifespan, fecundity, population growth, gamma ray-induced oxidative stress, and modulated patterns of enzyme activities and gene expressions after DNA damage. After gamma radiation, no individuals showed any mortality within 96 h even at a high intensity (1200 Gy). However, a reduced fecundity (e.g. cumulated number of offspring) of B. koreanus at over 150 Gy was observed along with a slight decrease in lifespan. At 150 Gy and 200 Gy, the reduced fecundity of the rotifers led to a significant decrease in population growth, although in the second generation the population growth pattern was not affected even at 200 Gy when compared to the control group. At sub-lethal doses, reactive oxygen species (ROS) levels dose-dependently increased with GST enzyme activity. In addition, up-regulations of the antioxidant and chaperoning genes in response to gamma radiation were able to recover cellular damages, and life table parameters were significantly influenced, particularly with regard to fecundity. DNA repair-associated genes showed significantly up-regulated expression patterns in response to sublethal doses (150 and 200 Gy), as shown in the expression of the gamma-irradiated B. koreanus p53 gene, suggesting that these sublethal doses were not significantly fatal to B. koreanus but induced DNA damages leading to a decrease of the population size.

  6. Critical care of sub-lethal irradiated transgenic mice using a complete soft food formula-DietGel76A™.

    Science.gov (United States)

    Jumanca, Ovidiu I; Palmer, Jay

    2015-01-01

    The objective of this research is to determine whether the administration of a complete soft food formula to sub-lethal irradiated animals from three different transgenic mouse strains over a period of 21 consecutive days will have a significant impact on the clinical signs, and the general survival rate of the animals. Our hypothesis is that using DietGel76A™, along with an antibiotic treatment, strict handling and manipulation procedures, the general mortality rate, as well as the onset of the clinical signs between the treated animals and the control animals, will be significantly lower. This hypothesis was confirmed for the C57BL/6 mice. However, the treatment with DietGel76A™ had only a very limited impact on the recovery of more irradiation sensitive strains (CD45.1 and mostly NRG). Further studies must be conducted on mice from these strains in order to assess whether mice belonging to more sensitive strains should be on DietGel76A™ for a longer period of time (at least 42days post irradiation). Copyright © 2014 Elsevier Inc. All rights reserved.

  7. The Effect of Pretreatment by using Electron Beam Irradiation on Oil Palm Empty Fruit Bunch

    Directory of Open Access Journals (Sweden)

    A. Kristiani

    2016-04-01

    Full Text Available Oil palm empty fruit bunch (OPEFB is a potential type of lignocellulosic biomass for second-generation bioethanol production. The pretreatment process is an important process in the series of processes to produce bioethanol. This research aims to study the effects of pretreatment process by using electron beam irradiation to OPEFB’s characterization as raw materials for the hydrolysis reaction to produce monomer sugars which will be fermented into ethanol. The untreated and treated OPEFB are characterized in terms of their physical and chemical properties. Analysis results of the compositional analysis by using NREL/TP-510-42618 method show that after pretreatment by using electron beam irradiation, OPEFB's total lignin content is changed little while its cellulose and hemicellulose contents tend to decrease with increasing irradiation dose. X-ray diffraction (XRD analysis shows that there is a decrease of crystallinity compared to untreated OPEFB, except for 200-kGy irradiated OPEFB. The highest decrease of crystallinity was shown by 300-kGy irradiated OPEFB. Further, crystallite sizes of treated OPEFBs are not significantly different from the untreated, except for the 200-kGy irradiated OPEFB. Irradiation pretreatment also increases specific surface area, pore volume, and pore size. The IR spectra analysis show the absorption of cellulose, hemicellulose, and lignin.

  8. Pretreatment with Fish Oil-Based Lipid Emulsion Modulates Muscle Leukocyte Chemotaxis in Murine Model of Sublethal Lower Limb Ischemia

    Directory of Open Access Journals (Sweden)

    Yao-Ming Shih

    2017-01-01

    Full Text Available This study investigated the effects of a fish oil- (FO- based lipid emulsion on muscle leukocyte chemotaxis and inflammatory responses in a murine model of limb ischemia-reperfusion (IR injury. Mice were assigned randomly to 1 sham (sham group, 2 ischemic groups, and 2 IR groups. The sham group did not undergo the ischemic procedure. The mice assigned to the ischemic or IR groups were pretreated intraperitoneally with either saline or FO-based lipid emulsion for 3 consecutive days. The IR procedure was induced by applying a 4.5 oz orthodontic rubber band to the left thigh above the greater trochanter for 120 min and then cutting the band to allow reperfusion. The ischemic groups were sacrificed immediately while the IR groups were sacrificed 24 h after reperfusion. Blood, IR-injured gastrocnemius, and lung tissues were collected for analysis. The results showed that FO pretreatment suppressed the local and systemic expression of several IR-induced proinflammatory mediators. Also, the FO-pretreated group had lower blood Ly6ChiCCR2hi monocyte percentage and muscle M1/M2 ratio than the saline group at 24 h after reperfusion. These findings suggest that FO pretreatment may have a protective role in limb IR injury by modulating the expression of proinflammatory mediators and regulating the polarization of macrophage.

  9. The effect of ribose pre-treatment of cortical bone on γ-irradiation sterilization effectiveness.

    Science.gov (United States)

    Attia, Tarik; Tupy, Jindra; Asker, Dalal; Hatton, Benjamin; Grynpas, Marc; Willett, Thomas

    2017-10-14

    Reconstruction of large skeletal defects is a significant and challenging issue. Tissue banks often use γ-irradiation (15-35 kGy) to sterilize bone allografts, which, however, drastically impairs the post-yield mechanical properties. In previous studies, we reported the development of a method that protects human bone collagen connectivity through ribose crosslinking while still undergoing γ-irradiation. Given these promising results, the next step was to determine if the presence of ribose within the bone tissue would interfere with the effectiveness of the γ-irradiation sterilization against bacteria. This study had two stages. The aim of the first stage was to assess the protective effect of ribose in solution using a Bacillus pumilus spore strip model. The aim of the second stage was to assess the protective effect of ribose (R) on spores within a human cortical bone model in comparison to conventionally irradiated bone (I). Treatment of B. pumilus spore strips with ribose in solution led to temperature-dependent effects on spore viability versus spore strips treated with PBS alone. Ribose solution at 60 °C led to a notable two logs decrease in spore count relative to PBS at 60 °C. In the human bone model, the number of spores in the I and R groups were greatly decreased in comparison to the non-irradiated N group. No spore colonies were detected in the R group (n = 4) whereas two of the four plates of group I formed colonies. This study provides evidence that the method of pre-treating bone with ribose crosslinking prior to irradiation sterilization, while improving irradiation sterilized bone allograft quality, also may improve the effectiveness of the sterilization process.

  10. Vitrification of bovine blastocysts pretreated with sublethal hydrostatic pressure stress: evaluation of post-thaw in vitro development and gene expression.

    Science.gov (United States)

    Siqueira Filho, E; Caixeta, E S; Pribenszky, C; Molnar, M; Horvath, A; Harnos, A; Franco, M M; Rumpf, R

    2011-01-01

    Sublethal stress treatment has been reported to enhance gametes' performance in subsequent procedures, such as cryopreservation. The aim of the present study was to evaluate the effect of different equilibration times between the termination of a sublethal hydrostatic pressure (HP) stress treatment and the initiation of vitrification on the post-thaw survival, continued in vitro development, hatching rate and gene expression of selected candidate genes of in vitro-produced (IVP) expanded bovine blastocysts. Day 7 IVP blastocysts were subjected to 600 bar pressure for 60 min at 32°C. Immediately after pressure treatment (HP0h) or after 1 or 2h incubation (HP1h and HP2h groups, respectively), embryos were either vitrified and warmed using the open pulled straw method, followed by 72 h in vitro culture or were stored at -80°C until gene expression analysis. Re-expansion and hatching rates after vitrification-warming were significantly (Pbovine embryos.

  11. Effect of gamma irradiation on pre-treatment on the drying characteristics and qualities of wheat

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Yong; Wang, Jun [Zhejiang University (China). Dept. of Biosystems Engineering

    2008-07-01

    Wheat, pretreated by {sup 60}Co gamma irradiation, was dried by hot-air with irradiation dosage 0-3 kGy, drying temperature 40-60 deg C, and initial moisture contents 19-25% (drying basis). The drying characteristics and dried qualities of wheat were evaluated based on drying time, average dehydration rate, wet gluten content (WGC), moisture content of wet gluten (MCWG)and titratable acidity (TA). A quadratic rotation-orthogonal composite experimental design, with three variables (at five levels) and five response functions, and analysis method were employed to study the effect of three variables on the individual response functions. The five response functions (drying time, average dehydration rate, WGC, MCWG, TA) correlated with these variables by second order polynomials consisting of linear, quadratic and interaction terms. A high correlation coefficient indicated the suitability of the second order polynomial to predict these response functions. The linear, interaction and quadratic effects of three variables on the five response functions were all studied. (author)

  12. Hydrogenolysis of lignins: influence of the pretreatment using microwave and ultrasound irradiations.

    Science.gov (United States)

    Gonçalves, Adilson R; Schuchardt, Ulf

    2002-01-01

    Hydrolytic eucalyptus lignin was converted to oils by hydrogenolysis. The lignin was obtained by acid hydrolysis of eucalyptus chips from two semi-industrial sources in Brazil: FTI and Coalbra. Hydrogenolysis was performed in an 1-L reactor using lignin/water ratio 1/4 (w/v), pH 9 (adjusted with NaOH), 0.1 g sodium formate/g lignin, 20 MPa (argon pressure) at 280 degrees C for 15 min. After reaction, the products were filtered and the solids extracted with chloroform/ethanol 3/1 (v/v). The solvent was evaporated from the organic phase and a dark oil was obtained. The solid remaining after extraction was weighed to calculate the conversion. Without pretreatment conversions were 41.3 and 47.9% for Coalbra and FTI, respectively. The oil yields were 22.7-27.6% for Coalbra and FTI, respectively. Using microwave pretreatment (30 min of irradiation at 490 W) the conversions were 41.6-50.5% and the oil yields increased slightly to 25.2-31.4%. The polymeric chains in the lignin breakdown due to the action of water near the boiling point under microwave irraditation. On the other hand, by using ultrasound (30 min at 50 degrees C in a ultrasound bath of 25 kHz and 0.8 W/cm2) the conversions were 35.2-46.9% and oil yields were 22.0-27.1%. Ultrasound favors the formation of radicals that probably caused the reticulation of lignins, decreasing the conversion and yield. Oils analyzed by infrared spectroscopy showed an increase in C=O bond intensities, compared with the original lignins.

  13. Effects of irradiation as a pretreatment in enzymatic hydrolysis of cellulose materials. [Electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, K.; Miyake, S.; Uda, I. (Sumitomo Electric Industries Ltd., Osaka (Japan))

    1983-01-01

    A flowchart shows the various processes investigated. Using rice straw and chaff as the materials, irradiation was carried out by an electron beam accelerator. After irradiation, some samples were milled and others treated by alkali and then hydrolized by an enzyme. Other samples were simultaneously milled and hydrolyzed by enzyme. The amount of glucose generated by saccharification was measured for each process. Results are shown for (a) effect of irradiation on particle size, (b) effect of irradiation on glucose yield, (c) effect of irradiation dose on lignin extraction by alkali treatment, (d) effects of NaOH concentration and irradiation dose on lignin extraction, (e) effects of temperature and irradiation dose on lignin extraction.

  14. Effects of low-temperature pretreatment on enhancing properties of refuse-derived fuel via microwave irradiation.

    Science.gov (United States)

    Liu, Zhen; Wang, Han-Qing; Zhou, Yue-Yun; Zhang, Xiao-Dong; Liu, Jian-Wen

    2017-07-01

    The present study focuses on pretreatment of enhancing the properties of refuse-derived fuel (RDF) via low-temperature microwave irradiation. These improved properties include lower chlorine content, a more porous surface structure and better combustion characteristics. In this study, low-temperature microwave irradiation was carried out in a modified microwave apparatus and the range of temperature was set to be 220-300℃. We found that the microwave absorbability of RDF was enhanced after being partly carbonized. Moreover, with the increasing of the final temperature, the organochlorine removal ratio was greatly increased to 80% and the content of chlorine was dramatically decreased to an extremely low level. It was also interesting to find that the chlorine of RDF was mainly released as HCl rather than organic chloride volatiles. The finding is just the same as the polyvinyl chloride pyrolysis process. In addition, pores and channels emerged during the modifying operation and the modified RDF has better combustibility and combustion stability than traditional RDF. This work revealed that low-temperature modification of RDF via microwave irradiation is significant for enhancing the quality of RDF and avoiding HCl erosion of equipment substantially.

  15. Effect of irradiation, as a pretreatment, on bioconversion of corn stover into protein-rich mycelial biomass of Pleurotus sajor-caju

    Science.gov (United States)

    Awafo, V. A.; Chahal, D. S.; Charbonneau, R.

    1995-09-01

    Application of irradiation for food preservation, for pretreatment of lignocellulosic materials for their hydrolysis and to increase the digestibility of lignocellulosic materials for rumen animals have been reported in the literature. In the present study, irradiation (100 KGy to 1.7 MGy) of corn stover as a pretreatment to make it susceptible for its bioconversion into protein-rich mycelial biomass of Pleurotus sajor-caju NRRL 18757 has been compared with that of mild alkali treatment (0.01 to 0.15 g NaOH/g corn stover), the most commonly used pretreatment. Protein synthesis increased with the increase in doses of irradiation as well as with the increase in concentration of NaOH. Combination pretreatment with NaOH and γ-irradiation reduced the quantity of NaOH and doses of irradiation required to get optimum yields of protein indicating a strong synergistic effect. The highest protein content of the final product, mycelial biomass, was about 45% on dry weight basis. More than 90% utilization of corn stover polysaccharides for the synthesis of protein-rich mycelial biomass of P. sajor-caju was recorded

  16. Effect of irradiation, as a pretreatment, on bioconversion of corn stover into protein-rich mycelial biomass of Pleurotus sajor-caju

    Energy Technology Data Exchange (ETDEWEB)

    Awafo, V.A.; Chahal, D.S.; Charbonneau, R. [Universite du Quebec (Canada). Applied Microbiology Research Center

    1995-10-01

    Application of irradiation for food preservation, for pretreatment of lignocellulosic materials for their hydrolysis and to increase the digestibility of lignocellulosic materials for rumen animals have been reported in the literature. In the present study, irradiation (100 KGy to 1.7 MGy) of corn stover as a pretreatment to make it susceptible for its bioconversion into protein-rich mycelial biomass of Pleurotus sajor-caju NRRL 18757 has been compared with that of mild alkali treatment (0.01 to 0.15 g NaOH/g corn stover), the most commonly used pretreatment. Protein synthesis increased with the increase in doses of irradiation as well as with the increase in concentration of NaOH. Combination pretreatment with NaOH and {gamma}-irradiation reduced the quantity of NaOH and doses of irradiation required to get optimum yields of protein indicating a strong synergistic effect. The highest protein content of the final product, mycelial biomass, was about 45% on dry weight basis. More than 90% utilization of corn stover polysaccharides for the synthesis of protein-rich mycelial biomass of P. sajor-caju was recorded. (author).

  17. Radio-induced neuropathology: from early effects to late sequelae. Rat behavioural and metabolic studies after sublethal total body irradiation; Neuropathologie radio-induite: des effets precoces aux sequelles tardives. Etudes comportementales et metaboliques chez le rat apres irradiation globale subletale

    Energy Technology Data Exchange (ETDEWEB)

    Martigne, A.P.

    2010-05-15

    The radioresistance dogma of Central Nervous System (CNS) is now obsolete. Recent progress in neuroscience allow us to reconsider the radiation-induced cognitive dysfunctions observed after radiation therapy or after a nuclear accident, and to devise appropriate diagnostic and therapeutic means. We have developed a Rat model to study the effects of total body irradiation at a sublethal dose (4.5 Gy). This leads to impaired learning and memory of a task being acquired during the first month - which is prevented by administration of a radioprotector (amifostine) - while it does not appear to affect retrograde memory. Early, an apoptotic wave occurs in the sub-ventricular zone, 5 to 9 hours after exposure, while neuro-genesis is suppressed. Two days after irradiation, the metabolic study conducted by NMR HRMAS (High Resolution Magic Angle Spinning) suggests the presence of cerebral oedema and the study of brain lipids in liquid NMR confirms the membrane damages (elevated cholesterol and phospholipids). The lipid profile is then normalized while a gliosis appears. Finally, 1 month post-irradiation, the elevation of GABA, an inhibitory neurotransmitter, in 2 separate brain structures, occurs simultaneously with a taurine decrease in the hippocampus that lasts 6 months. Our integrated model allows validating bio-markers measurable in vivo NMR spectroscopy - the next experimental stage - and testing new radiation-protective agents. (author)

  18. Immunological and clinical observations in diabetic kidney graft recipients pretreated with total-lymphoid irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Waer, M.; Vanrenterghem, Y.; Roels, L.; Ang, K.K.; Bouillon, R.; Lerut, T.; Gruwez, J.; van der Schueren, E.; Vandeputte, M.; Michielsen, P.

    1987-03-01

    In a feasibility study, twenty patients with end-stage diabetic nephropathy were treated with fractionated total-lymphoid irradiation (TLI, mean dose 25 Gy), before transplantation of a first cadaveric kidney. During radiotherapy, only one patient had a serious side effect (bone marrow depression). After transplantation four patients died (one of a myocardial infarction, one of ketoacidosis, and two of infections occurring during treatment of rejection crises). One graft was lost because of chronic rejection. The other 15 patients have a functioning graft (mean follow-up 24 months) and receive low-dose prednisone alone (less than 10 mg/day, n = 11) or in conjunction with cyclosporine (n = 4) as maintenance immunosuppressive therapy. A favorable clinical outcome after TLI (no, or only one, steroid-sensitive rejection crisis) was significantly correlated with a high pre-TLI helper/suppressor lymphocyte ratio, a short interval between TLI and the time of transplantation, and the occurrence of functional suppressor cells early after TLI. The most striking immunological changes provoked by TLI consisted of a long-term depression of the mixed lymphocyte reaction and of the phytohemagglutinin, and Concanavalin A or pokeweed-mitogen-induced blastogenesis. A rapid and complete recovery of the natural killer cell activity was observed after TLI. A permanent inversion of the OKT4+ (T helper/inducer) over OKT8+ (T suppressor/cytotoxic) lymphocyte ratio was provoked by a decrease of the OTK4+ subpopulation, together with a supranormal recovery of the OKT8+ lymphocytes. A majority of the latter lymphocytes did also express the Leu 7 and the Leu 15 phenotype.

  19. Increased formation of halomethanes during chlorination of chloramphenicol in drinking water by UV irradiation, persulfate oxidation, and combined UV/persulfate pre-treatments.

    Science.gov (United States)

    Wenhai, Chu; Tengfei, Chu; Erdeng, Du; Deng, Yang; Yingqing, Guo; Naiyun, Gao

    2016-02-01

    Ultraviolet/persulfate (UV/PS) has been widely used to generate sulfate radicals for degradation of water organic pollutants in previous studies. However, its impacts on disinfection byproduct formation during post-chlorination of degraded compounds is unclear. The objective of this study was to evaluate the impacts of UV irradiation, PS oxidation, and the combined UV/PS advanced oxidation process (AOP) pre-treatments on halomethane formation during the following chlorination of chloramphenicol (CAP), a model antibiotic commonly found in wastewater-impacted water. Results showed that CAP could be transformed to more trichloromethane (TCM) than monochloromethane (MCM) and dichloromethane (DCM) in the presence of excess chlorine. UV photolysis, PS oxidation and UV/PS AOP all directly decomposed CAP to produce halomethanes (HMs) before post-chlorination. Moreover, UV and UV/PS pre-treatments both enhanced the formation of all the HMs in the subsequent chlorination. PS pre-oxidation decreased the TCM formation during post-chlorination, but increased the yields of MCM, DCM and total HMs. UV pre-irradiation significantly increased the bromide utilization of HMs, whereas UV/PS pre-oxidation decreased the bromine incorporation and utilization of HMs from the chlorination of CAP in a low-bromide water. UV irradiation, PS oxidation, and UV/PS AOP can inactivate pathogens and degrade organic pollutants, but this benefit should be weighed against a potential risk of the increased halomethane formation from degraded organic pollutants with and without post-chlorination. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Effect of Nd:YAG Laser Irradiation Pretreatment on the Long-Term Bond Strength of Etch-and-Rinse Adhesive to Dentin.

    Science.gov (United States)

    Gan, J; Liu, S; Zhou, L; Wang, Y; Guo, J; Huang, C

    To investigate the effect of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiation pretreatment on the long-term bond strength of an etch-and-rinse adhesive to dentin. Fifty molars were sectioned parallel to the occlusal plane and randomly divided into two groups (n=25 per group): control group (no treatment) and laser group (dentin surfaces were treated with Nd:YAG laser at a setting of 100 mJ/10 Hz). Afterward, resin was bonded to the dentin surface using a two-step etch-and-rinse adhesive (Adper SingleBond 2), and then 150 beams of each group were produced. Each group was divided into three subgroups (n=50 each group): 24 hours of water storage, thermocycling, and NaOCl storage. The microtensile bond strength (MTBS), failure modes, nanoleakage expression, and Masson's trichrome staining were evaluated. An additional 20 molars were sectioned to obtain 2-mm-thick flat dentin slices. These slices were randomly divided into control and laser-treated groups as mentioned previously. Then slices of each group were examined by scanning electron microscopy, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), and the Knoop hardness test. The results of ATR-FTIR and Masson's trichrome verified that laser irradiation partly removed collagen fibers from the dentin surface; however, no significant difference was found in the Knoop hardness (p>0.05). The XRD result showed similar crystalline structure regardless of laser pretreatment. There is no significant difference in short-term MTBS between control and laser-treated groups (p>0.05); however, long-term MTBS differed between the groups (p>0.05). Furthermore, the laser-treated group showed less silver deposition than the control group after aging (padhesive-dentin bonding in vitro test, and the bonding effectiveness could be preserved after aging.

  1. Sublethal Photothermal Stimulation with a Micropulse Laser Induces Heat Shock Protein Expression in ARPE-19 Cells

    Directory of Open Access Journals (Sweden)

    Keiji Inagaki

    2015-01-01

    Full Text Available Purpose/Aim of the Study. Subthreshold micropulse diode laser photocoagulation is an effective treatment for macular edema. The molecular mechanisms underlying treatment success are poorly understood. Therefore, we investigated the effects of sublethal laser energy doses on a single layer of densely cultured ARPE-19 cells as a model of the human retinal pigment epithelium (RPE. Materials and Methods. A single layer of densely cultured human ARPE-19 cells was perpendicularly irradiated with a micropulse diode laser. Nonirradiated cells served as controls. Sublethal laser energy was applied to form a photocoagulation-like area in the cultured cell layers. Hsp70 expression was evaluated using quantitative polymerase chain reaction and immunocytochemistry. Results. Photocoagulation-like areas were successfully created in cultured ARPE-19 cell layers using sublethal laser energy with our laser irradiation system. Hsp70 mRNA expression in cell layers was induced within 30 min of laser irradiation, peaking at 3 h after irradiation. This increase was dependent on the number of laser pulses. Hsp70 upregulation was not observed in untreated cell layers. Immunostaining indicated that Hsp70 expression occurred concentrically around laser irradiation sites and persisted for 24 h following irradiation. Conclusion. Sublethal photothermal stimulation with a micropulse laser may facilitate Hsp70 expression in the RPE without inducing cellular damage.

  2. Comparative study on gamma irradiation and cold plasma pretreatment for a cellulosic substrate modification with phenolic compounds

    Science.gov (United States)

    Irimia, Anamaria; Ioanid, Ghiocel Emil; Zaharescu, Traian; Coroabă, Adina; Doroftei, Florica; Safrany, Agnes; Vasile, Cornelia

    2017-01-01

    The efficiency of the activation of the cellulose/chitin mix substrate by cold plasma or γ-radiation exposure in order to modify it with bioactive compounds was studied. The eugenol or vegetable oils such as grape seed oil and rosehip seed oil have been grafted onto activated substrate. The examination of modified cellulose/chitin mix substrate by ATR-FTIR spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy confirms that the structural and morphological changes took place in both cases. The grafting degrees of the surface layer estimated from XPS data varied from 31.1% to 58.7% for air cold plasma activation and from 9.7% to 22.8% for γ-irradiation treatment. They depend both on bioactive compound used and procedure of substrate activation. Higher grafting degree are obtain by using vegetable oils than in the case of modification with eugenol and the air cold plasma activation seems to be much efficient than γ-irradiation. By grafting the polymeric substrate with bioactive compounds, antimicrobial and antioxidant properties have been conferred. Such materials can be considered promising for food packaging applications and medical textiles and also the applied procedures are environmental friendly ones.

  3. The use of microwave irradiation as a pretreatment to in situ hybridization for the detection of measles virus and chicken anaemia virus in formalin-fixed paraffin-embedded tissue

    Energy Technology Data Exchange (ETDEWEB)

    McMahon, J.; McQuaid, S. [Royal Group of Hospitals, Belfast (United Kingdom). Neuropathology Lab.]|[Queen`s Univ., Belfast, Northern Ireland (United Kingdom)

    1996-03-01

    Microwave irradiation was investigated as a pretreatment to in situ hybridization on formalin-fixed, paraffin-embedded tissue. Two probe/tissue systems were used: a single-stranded RNA probe for the detection of measles virus nucleocapsid genome in subacute sclerosing panencephalitis brain tissue, and a double stranded DNA probe for chicken anaemia virus in thymus of chicken infected with the virus. Microwaving, when used as sold pretreatment, was not as effective as the more traditional enzyme pretreatments for in situ hybridization. However, when used in combination with existing pretreatments, a significant increase was found in hybridization signal in both brain and thymus tissue. This was emphasized when combination enzyme/microwave pretreatments were used prior to detection of measles virus by in situ hybridization in a series of five archival subacute sclerosing panencephalitis cases. The use of microwave irradiation would be recommended as a means of supplementing in situ hybridization methods, especially when using long-term formalin fixed paraffin-embedded tissue. (Author).

  4. Effect of surface pretreatment of TiO2 films on interfacial processes leading to bacterial inactivation in the dark and under light irradiation

    Science.gov (United States)

    Rtimi, Sami; Nesic, Jelena; Pulgarin, Cesar; Sanjines, Rosendo; Bensimon, Michael; Kiwi, John

    2015-01-01

    Evidence is presented for radio-frequency plasma pretreatment enhancing the amount and adhesion of TiO2 sputtered on polyester (PES) and on polyethylene (PE) films. Pretreatment is necessary to attain a suitable TiO2 loading leading to an acceptable Escherichia coli reduction kinetics in the dark or under light irradiation for PES–TiO2 and PE–TiO2 samples. The amount of TiO2 on the films was monitored by diffuse reflectance spectroscopy and X-ray fluorescence. X-ray electron spectroscopy shows the lack of accumulation of bacterial residues such as C, N and S during bacterial inactivation since they seem to be rapidly destroyed by TiO2 photocatalysis. Evidence was found for Ti4+/Ti3+ redox catalysis occurring on PES–TiO2 and PE–TiO2 during the bacterial inactivation process. On PE–TiO2 surfaces, Fourier transform infrared spectroscopy (ATR-FTIR) provides evidence for a systematic shift of the na(CH2) stretching vibrations preceding bacterial inactivation within 60 min. The discontinuous IR-peak shifts reflect the increase in the C–H inter-bond distance leading to bond scission. The mechanism leading to E. coli loss of viability on PES–TiO2 was investigated in the dark up to complete bacterial inactivation by monitoring the damage in the bacterial outer cell by transmission electron microscopy. After 30 min, the critical step during the E. coli inactivation commences for dark disinfection on 0.1–5% wt PES–TiO2 samples. The interactions between the TiO2 aggregates and the outer lipopolysaccharide cell wall involve electrostatic effects competing with the van der Waals forces. PMID:25657831

  5. Resistance to the induction of EAE in AO rats: its prevention by the pre-treatment with cyclophosphamide or low dose of irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Mostarica-Stojkovic, M.; Petrovic, M.; Lukic, M.L. (Belgrade Univ. (Yugoslavia). Medicinski Fakultet; Inst. for Biological Research, Belgrade (Yu). Lab. for Cellular Immunology)

    1982-11-01

    Susceptibility to the induction of experimental allergic encephalomyelitis (EAE) was compared in AO, DA and Lewis strain of rats. As evaluated by clinical and histological criteria, AO rats exhibited significantly lower susceptibility to EAE induced with guinea-pig spinal cord (GPSC) tissue and complete resistance to the encephalitogenic challenge with rat myelin basic protein (BP) irrespective of antigen dose and adjuvant used. AO rats pre-treated with BP + Freund's incomplete adjuvant became completely unresponsive to the induction of EAE with GPSC + Freund's complete adjuvant (FCA) indicating that they do possess cells sensitive to some antigenic determinants of rat BP. In order to test whether the resistance to EAE is due to an active suppression, low dose of irradiation (300 rad) and cyclophosphamide (20 mg/kg) was applied prior to the induction of EAE. Selective depletion of radiosensitive cells facilitated the induction of EAE. Similarly cyclophosphamide given 2 days prior to BP + FCA completely abrogated the resistance to EAE induction. Thus, it appears that the inability of BP + FCA to produce EAE in AO rats is due to the disproportionate activation of suppressor cells.

  6. Increased viability and resilience of haemolymph cells in blue mussels following pre-treatment with acute high-dose gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Jaeschke, B. [Stockholm University (Sweden)

    2014-07-01

    In an initial experiment, blue mussels (Mytilus edulis) were exposed to a range of acute high doses of gamma radiation in the laboratory. Haemolymph was extracted and the haemocytes (blood cells) were scored for cell viability (% living cells) under a microscope, directly after irradiation (0.04, 0.4 or 4 Gy) and again after a subsequent treatment with hydrogen peroxide in vitro (final H{sub 2}O{sub 2} conc.: 0.2 μM). Cell viability in controls (0 Gy) was approximately 100% and no cell death was observable from radiation exposure alone. When treated with H{sub 2}O{sub 2} a decrease in cell viability was seen across all treatments, however this decrease in viability was reduced with increasing radiation pre-treatment (0 Gy = 53%; 0.04 Gy = 66%; 0.4 Gy = 75%; 4 Gy = 83%). To investigate the mechanism for this therapeutic effect observed, the experiment was repeated. Using mussels from a different location, the same, but more extensive method of irradiation (0[control], 0.04, 0.4 Gy, 5 or 40 Gy) and H{sub 2}O{sub 2} treatment was used. Additional haemolymph sub-samples were taken for analysis of catalase concentration. In this second experiment, viability of cells from controls was only 62%, indicating the mussels were in a poorer condition than those of the previous experiment. The lowest level of radiation exposure (0.04 Gy) further decreased the viability (56%). However, at higher doses the viability was increased compared to control, which then gradually declined with increasing dose (0.4 Gy = 75%; 5 Gy = 72%; 40 Gy = 65%). Catalase analysis demonstrated a complimentary pattern of activity of the antioxidant in the haemolymph, directly correlating with radiation dose (0 Gy = 0.2 U; 0.04 Gy = 0.1 U; 0.4 Gy = 1.3 U; 5 Gy = 0.9 U; 40 Gy = 0.1 Gy). Treatment with H{sub 2}O{sub 2} decreased cell viability across all treatments, but no pattern between radiation treatments was discernable. The results indicate that an acute dose of radiation not only has negligible

  7. Biomass pretreatment

    Science.gov (United States)

    Hennessey, Susan Marie; Friend, Julie; Elander, Richard T; Tucker, III, Melvin P

    2013-05-21

    A method is provided for producing an improved pretreated biomass product for use in saccharification followed by fermentation to produce a target chemical that includes removal of saccharification and or fermentation inhibitors from the pretreated biomass product. Specifically, the pretreated biomass product derived from using the present method has fewer inhibitors of saccharification and/or fermentation without a loss in sugar content.

  8. Response to and recovery from acute sublethal gamma radiation in the Amazon molly, Poecilia formosa

    Energy Technology Data Exchange (ETDEWEB)

    Woodhead, A.D.; Setlow, R.B.

    1979-05-01

    Acute irradiation of the Amazon molly with a sublethal dose of 1,000 rad caused some damage to the intestinal tract and to the haematopoietic system. Histologically, the intestine appeared to have regenerated by the end of a week; damage to the haematopoietic tissue appeared more slowly, but repair was almost complete some two months later. Nevertheless, recovery to the intestine cannot have been entirely completed in seven days, since the fish did not feed well for the following two weeks. After this, there were no obvious deleterious effects upon the survival and viability of the fish, although irradiated fish weighed less at the termination of the experiment.

  9. Skin tumor development after UV irradiation and photodynamic therapy is unaffected by short-term pretreatment with 5-fluorouracil, imiquimod and calcipotriol

    DEFF Research Database (Denmark)

    Bay, Christiane; Togsverd-Bo, Katrine; Lerche, Catharina M

    2016-01-01

    Background Photodynamic therapy (PDT) delays ultraviolet (UV) radiation-induced squamous cell carcinomas (SCCs) in hairless mice. Efficacy may be enhanced by combining PDT with antineoplastic or pro-differentiating agents. We investigated if pretreatment with 5-fluorouracil (5FU), imiquimod (IMIQ......) or calcipotriol (CAL) before PDT further delays tumor onset. Methods Hairless mice (n = 224) were exposed 3 times weekly to 3 standard erythema doses (SED) of UV radiation. Methyl-aminolevulinate (MAL)-PDT sessions were given on days 45 and 90 before SCC development. Three applications of topical 5FU, IMIQ or CAL...... were given before each PDT session. Fluorescence photography quantified protoporphyrin IX (PpIX) formation. Results PDT delayed UV-induced SCC development by 59 days (212 days UV-MAL-PDT vs. 153 days UV-control, P PDT did not further delay SCC onset...

  10. Photoorientation of a liquid-crystalline polyester with azobenzene side groups: Effects of irradiation with linearly polarized red light after photochemical pretreatment

    DEFF Research Database (Denmark)

    Zebger, Ingo; Rutloh, Michael; Hoffmann, Uwe

    2003-01-01

    of this two-step process is the angular-selective transformation of the bulky Z-isomers to the rodlike E-isomeric formed by the red light. The aligned E-azobenzene side groups become strongly J-aggregated. Very high values of dichroism of about 0.8 and birefringence of about 0.3 were generated as a result......-isomer, which destroys any initial orientational order and J-aggregates. The orientation process is cooperative, whereas the light-induced orientation of the photochromic moiety causes an ordering of the alkylene spacers and even of the main-chain segments into the same direction. The most probable mechanism...... of this combination of the photoinduced orientation process and the thermotropic self-organization, which take place simultaneously under the irradiation conditions. The process results in a uniaxial prolate order of the film, whereas conventional photoorientation leads to a biaxial oblate order. These two different...

  11. Sublethal effects of manganese on the carbohydrate metabolism of ...

    African Journals Online (AJOL)

    Carbohydrate metabolism variables of Oreochromis mossambicuswere investigated after acute and chronic sublethal manganese exposure. The sublethal concentrations were determined from the LC50 value of manganese. After the exposures, the fish were carefully netted and blood was drawn from the caudal aorta.

  12. Protective effect of a laser-induced sub-lethal temperature rise on RPE cells from oxidative stress.

    Science.gov (United States)

    Iwami, Hisashi; Pruessner, Joachim; Shiraki, Kunihiko; Brinkmann, Ralf; Miura, Yoko

    2014-07-01

    Recently introduced new technologies that enable temperature-controlled laser irradiation on the RPE allowed us to investigate temperature-resolved RPE cell responses. In this study we aimed primarily to establish an experimental setup that can realize laser irradiation on RPE cell culture with the similar temperature distribution as in the clinical application, with a precise time/temperature history. With this setup, we conducted investigations to elucidate the temperature-dependent RPE cell biochemical responses and the effect of transient hyperthermia on the responses of RPE cells to the secondary-exposed oxidative stress. Porcine RPE cells cultivated in a culture dish (inner diameter = 30 mm) with culture medium were used, on which laser radiation (λ = 1940 nm, spot diameter = 30 mm) over 10 s was applied as a heat source. The irradiation provides a radially decreasing temperature profile which is close to a Gaussian shape with the highest temperature in the center. Power setting for irradiation was determined such that the peak temperature (Tmax) in the center of the laser spot at the cells reaches from 40 °C to 58 °C (40, 43, 46, 50, 58 °C). Cell viability was investigated with ethidium homodimer III staining at the time points of 3 and 24 h following laser irradiation. Twenty four hours after laser irradiation the cells were exposed to hydrogen peroxide (H2O2) for 5 h, followed by the measurement of intracellular glutathione, intracellular 4-hydroxynonenal (HNE) protein adducts, and secreted vascular endothelial growth factor (VEGF). The mean temperature threshold for RPE cell death after 3 h was found to be around 52 °C, and for 24 h around 50 °C with the current irradiation setting. A sub-lethal preconditioning on Tmax = 43 °C significantly induced the reduced glutathione (GSH)/oxidized glutathione (GSSG) ratio, and decreased H2O2-induced increase of intracellular 4-HNE protein adducts. Although sub-lethal hyperthermia (Tmax

  13. Sublethal consequences of urban life for wild vertebrates

    National Research Council Canada - National Science Library

    Gallagher, Austin J; Peiman, Kathryn S; de Bruijn, Robert; Cooke, Steven J; Birnie-Gauvin, Kim

    2016-01-01

    ... — while others have not. Here we present a review of the sublethal consequences of life in the city for wild vertebrates, and demonstrate that urban animals face an almost completely different set of physiological...

  14. [Repair mechanism of frozen sublethally damaged Staphylococcus aureus].

    Science.gov (United States)

    Huang, Zhongmin; Lv, Haipeng; Ai, Zhilu; Wang, Na; Xie, Xinhua; Fan, Huiping; Pan, Zhili; Suo, Biao

    2015-11-04

    To study the repair mechanisms of frozen sublethally damaged Staphylococcus aurous cells. We resuscitated frozen sublethally damaged S. aureus at 37 degrees C for different time within 3 h. Meanwhile, we compared the morphological changes of the frozen sublethally damaged cells after 1 h of resuscitation using transmission electron microscopy assay (TEM). The expressions of the transcriptional attenuator MsrR (msrR), iron (Fe3+) ABC transporter ATP-binding protein (fhuC), and cytochrome b (cytB) genes were quantitatively analyzed by real-time fluorescence quantitative PCR (Real-time PCR) method. The content of cells outside leakage, active oxygen (ROS), and superoxide dismutase (SOD) activity were also determined by ultraviolet spectrophotometry. More than 99% of the frozen sublethally damaged S. aureus repaired after 3 h. The resuscitated cells expressed an equal resistance to high concentration of NaCl. Real-time PCR results showed that the msrR and fhuC genes expressions were down-regulated, whereas the cytB gene expression was up-regulated significantly. The frozen sublethally damaged S. aureus cellar surface ultrastructure significant changed during resuscitation. The cell surface became compact and sturdy from smooth and transparent. The cell leakage rate of ultraviolet absorption material gradually decreased. Meanwhile, the intracellular ROS level declined along with the decrease of SOD activity. Frozen sublethally damaged cells may regain the capability of resistance to high salt stress by repairing cell membrane integrity, reducing the content of ROS through gene regulation, inhibiting the toxicity of active oxygen to the cells. Meanwhile, the regulation of metabolism related genes (cytB) provides the energy for the requirement of cells, therefore, the frozen sublethally damaged cells were repaired finally.

  15. The growth and development of Schistosoma mansoni in mice exposed to sublethal doses of radiation

    Energy Technology Data Exchange (ETDEWEB)

    Aitken, R.; Wilson, R.A. (Univ. of York, Heslington (England))

    1989-12-01

    The maturation of Schistosoma mansoni was studied in mice exposed to various sublethal doses of radiation. Although the treatment of mice with 500 rads of radiation prior to infection did not alter parasite maturation, doses in excess of 500 rads led to a reduction in worm burden. This could not be attributed to a delay in the arrival of parasites in the hepatic portal system. Worms developing in mice treated with 800 rads commenced egg-laying about 1 wk later than worms in intact mice, and the rate of egg deposition appeared to be lower in irradiated hosts. The data demonstrate that exposure of C57BL/6 mice to doses of radiation in excess of 500 rads impairs their ability to carry infections of S. mansoni. The findings do not support the hypothesis that primary worm burdens in the mouse are controlled by a host immune response.

  16. Lethal and sub-lethal effects of UVB on juvenile Biomphalaria glabrata (Mollusca: Pulmonata).

    Science.gov (United States)

    Ruelas, Debbie S; Karentz, Deneb; Sullivan, John T

    2006-11-01

    Although Schistosoma mansoni occurs mainly in the tropics, where intense levels of solar radiation are present, the impact of ultraviolet (UV) light on schistosome transmission is not known. The purpose of this study was to investigate potential effects of UVB (290-320nm) on juvenile Biomphalaria glabrata, the snail intermediate host of S. mansoni. Albino and wild-type snails were exposed to doses of UVB from UV-fluorescent lamps, and the following were measured: survival, photoreactivation (light-mediated DNA repair), effects on feeding behavior, and morphological tissue abnormalities. Irradiation with UVB is lethal to B. glabrata in a dose-dependent manner. Exposure to white light subsequent to UVB irradiation enhances survival, probably by photoreactivation. The shell offers some, but not complete, protection. Experiments in which UVB transmittance through the shell was blocked with black nail polish suggest that injury to both exposed (headfoot) and shell-enclosed (mantle and visceral mass) tissues contributes to mortality in lethally irradiated snails. Wild-type (pigmented) snails are less susceptible to lethal effects of UVB than albino snails, and they may be more capable of photoreactivation. UVB exposure inhibits snail feeding behavior, and causes tentacle forks and growths on the headfoot. Thus, UVB may influence the life cycle of S. mansoni by both lethal and sub-lethal damage to the snail intermediate host. However, the ability of snails to photoreactivate may mitigate these effects.

  17. Effect of ultrasonic pretreatment on emulsion polymerization of styrene.

    Science.gov (United States)

    Nagatomo, Daichi; Horie, Takafumi; Hongo, Chizuru; Ohmura, Naoto

    2016-07-01

    This study investigated the effect of pretreatment of ultrasonic irradiation on emulsion polymerization of styrene to propose a process intensification method which gives high conversion, high reaction rate, and high energy efficiency. The solution containing styrene monomer was irradiated by a horn mounted on the ultrasonic transducer with the diameter of 5mm diameter and the frequency of 28 kHz before starting polymerization. The pretreatment of ultrasound irradiation as short as 1 min drastically improved monomer dispersion and increased reaction rate even under the agitation condition with low rotational speed of impeller. Furthermore, the ultrasonic pretreatment resulted in higher monomer concentration in polymer particles and produced larger polymer particles than conventional polymerization without ultrasonic pretreatment. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. UV-irradiation and leaching in water reduce the toxicity of imidacloprid-contaminated leaves to the aquatic leaf-shredding amphipod Gammarus fossarum.

    Science.gov (United States)

    Englert, Dominic; Zubrod, Jochen P; Neubauer, Christoph; Schulz, Ralf; Bundschuh, Mirco

    2018-01-27

    Systemic neonicotinoid insecticides such as imidacloprid are increasingly applied against insect pest infestations on forest trees. However, leaves falling from treated trees may reach nearby surface waters and potentially represent a neonicotinoid exposure source for aquatic invertebrates. Given imidacloprid's susceptibility towards photolysis and high water solubility, it was hypothesized that the leaves' toxicity might be modulated by UV-irradiation during decay on the forest floor, or by leaching and re-mobilization of the insecticide from leaves within the aquatic ecosystem. To test these hypotheses, the amphipod shredder Gammarus fossarum was fed (over 7 d; n = 30) with imidacloprid-contaminated black alder (Alnus glutinosa) leaves that had either been pre-treated (i.e., leached) in water for up to 7 d or UV-irradiated for 1 d (at intensities relevant during autumn in Central Europe) followed by a leaching duration of 1 d. Gammarids' feeding rate, serving as sublethal response variable, was reduced by up to 80% when consuming non-pretreated imidacloprid-contaminated leaves compared to imidacloprid-free leaves. Moreover, both leaching of imidacloprid from leaves (for 7 d) as well as UV-irradiation reduced the leaves' imidacloprid load (by 46 and 90%) thereby mitigating the effects on gammarids' feeding rate to levels comparable to the respective imidacloprid-free controls. Therefore, natural processes, such as UV-irradiation and re-mobilization of foliar insecticide residues in water, might be considered when evaluating the risks systemic insecticide applications in forests might pose for aquatic organisms in nearby streams. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Sublethal effects of manganese on the haematology and ...

    African Journals Online (AJOL)

    Information concerning the sublethal effects of pollutants, such as metals, forms an integral part of ecosystem health assessment programmes and of procedures followed to develop water quality guidelines for environmetal protection. The data from this study were incorporated into a water quality index (RAUWaterz) ...

  20. Sublethal haematological effects of zinc on the freshwater fish ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... industrial and domestic wastes water discharges and animals where it ... that zinc could cause sub-acute effects that change fish behaviours. ... These include the sublethal effects of concentrations of water extracts of akee apple on C. gariepinus (Onusiriuka and Ufodike, 1998). Toxicity of cas- sava leaf ...

  1. Effects of sublethal doses of chlorfluazuron on the ovarian ...

    African Journals Online (AJOL)

    Therefore, it is concluded that sublethal doses of chlorfluazuron reduced the amounts of ovarian constituents during ovarian development and oogenesis in S. litura. These reductions increased with an increase in dose from LD10 to LD30. The effects of chlorfluazuron on the amounts of ovarian constituents are presumed to ...

  2. Histopathological effects of lethal and sub-lethal concentrations of ...

    African Journals Online (AJOL)

    The histopathological effects of lethal and sub-lethal concentrations of glyphosate on African catfish Clarias gariepinus were investigated. C. gariepinus juveniles were assessed in a static renewal bioassay for 96 hours (acute toxicity) and 28 days (chronic toxicity) using varying concentrations (0.0 mg/l 20.0 mg/l, 30.0 mg/l, ...

  3. Review: Sublethal effects of temperature on freshwater organisms ...

    African Journals Online (AJOL)

    Review: Sublethal effects of temperature on freshwater organisms, with special reference to aquatic insects. HF Dallas, V Ross-Gillespie. Abstract. Water temperature is a key variable affecting aquatic organisms. Understanding their response to elevated water temperatures is important for estimating upper thermal limits, ...

  4. Impact of sublethal concentration of triazophos on regulation of ...

    African Journals Online (AJOL)

    Exposure to sublethal doses of triazophos extract caused significant (p < 0.05) time and dose dependent reduction in the levels of total protein, acetylcholinesterase (AchE) and significant enhancement in the levels of total free amino acids, glutamine, adenosine monophosphate (AMP) deaminases, adenosine deaminases, ...

  5. Sublethal effects of industrial chemicals on fish fingerlings ( Tilapia ...

    African Journals Online (AJOL)

    Tilapia guineensis commonly found in the Niger Delta ecological zone of Nigeria was exposed to sublethal concentrations (1.56, 3.13 mg/l) of neatex (industrial detergent) and norust CR 486 (corrosion inhibitor) using the Organisation for Economic Cooperation and Development (OECD) # 203 protocol. At test termination ...

  6. Sublethal effects of carbaryl on embryonic and gonadal ...

    African Journals Online (AJOL)

    Sex reversal was delayed in the experimental groups, with a sex ratio of 13 females to 0 males, but the control group recorded 6 females to 8 males. These results suggest that sublethal doses of carbaryl in the environment, similar to those used in the current study, may have an adverse effect on the reproductive success of ...

  7. Effects Of Exposure To Sublethal Concentrations Of Azadirachta ...

    African Journals Online (AJOL)

    The physiological impairment on the fingerlings of Clarias gariepinus when exposed to sublethal concentrations of Azadirachta Indica was investigated. The fish were exposed to concentrations of 1.25, 2.50, 5.0, 10.0, 20.0 ML -1 for the period of 12 weeks. The crude protein content decreased with increased concentration ...

  8. Effects of sub-lethal doses of photo-activated disinfection against Porphyromonas gingivalis for pharmaceutical treatment of periodontal-endodontic lesions.

    Science.gov (United States)

    Pourhajibagher, Maryam; Chiniforush, Nasim; Raoofian, Reza; Ghorbanzadeh, Roghayeh; Shahabi, Sima; Bahador, Abbas

    2016-12-01

    Microorganisms treated by photo-activated disinfection (PAD) in combined periodontal-endodontic (perio-endo) lesions would be exposed to sub-lethal doses of PAD (sPAD). This study evaluated the effect of sPAD using toluidine blue O (TBO) in combination with diode laser irradiation on the growth and biofilm-formation ability of Porphyromonas gingivalis as an endo-periodontal pathogen. The antibacterial and antibiofilm potential of sPAD against P. gingivalis was analyzed at sub-lethal doses of TBO and irradiation time of diode laser on a colony-forming unit and crystal violet assays, respectively. TBO-mediated PAD, using 6.25-100μg/mL at a fluency of 171.87J/cm(2) and 12.5-100μg/mL at a fluency of 137.5J/cm(2), showed a significant dose-dependent reduction in P. gingivalis growth when compared to the control. TBO-mediated PAD showed a significantly inhibitory effect on biofilm formation in P. gingivalis than TBO-PAD at sub-lethal levels. High doses of sPAD revealed antibacterial and antibiofilm potential activity, whereas lower doses of sPAD had conflicting results. Therefore, when PAD is prescribed in combined perio-endo lesions treatment, the dose of PAD used in vivo should be taken into account. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Pesticides and Arthropods: Sublethal Effects and Demographic Toxicology

    Directory of Open Access Journals (Sweden)

    Dejan Marčić

    2007-01-01

    Full Text Available Insecticides and acaricides designed to control primary harmful insects and mites may also variously affect some other arthopods present in an (agroecosystem (e.g. secondary pests, predators, parasitoids, saprophytes, bioindicators, pollinators. Apart from insecticides and acaricides, arthropods may also be affected by the activity of other pesticides (fungicides, herbicides, etc.. Regardless of whether they are deemed desirable or not, the effects that pesticides have on arthopods need to be quantified as closely as possible through appropriate experimental procedures. Data acquired in tests designed to determined LD50/LC50 values are inadequate for evaluation of pesticide effectiveness in the field as pesticidesalso cause various sublethal effects, generally disregarded in such investigations. The sublethal effects of pesticides refer to any altered behaviour and/or physiology of individuals that have survived exposure to pesticides at doses/concentrations that can be lethal(within range causing mortality in an experimental population that exceeds mortality in an untreated population or sublethal (below that range. Pesticides affect locomotion and mobility, stimulate dispersion of arthropods from treated areas, complicate or prevent their navigation, orientation and ability to locate hosts, and cause changes in their feeding, mating and egg-laying patterns. Sublethal pesticide effects on arthropod physiology reflect on the life span, rate of development, fecundity and/or fertility, sex ratio and immunity of surviving individuals. Different parameters are being used in arthropod bioassays to determine sublethal effects (ED50/EC50, LOEC, NOEC, total effect index. Compared to acute toxicity tests, these parameters improve the quality of evaluation and create a more accurate view of the effects of a pesticide. However, such approach covers mainly fecundity/fertility alone, while all other sublethal effects remain unaccounted for. Besides, it

  10. Sublethal Heavy Metal Stress Stimulates Innate Immunity in Tomato

    Directory of Open Access Journals (Sweden)

    Nilanjan Chakraborty

    2015-01-01

    Full Text Available Effect of sublethal heavy metal stress as plant biotic elicitor for triggering innate immunity in tomato plant was investigated. Copper in in vivo condition induced accumulation of defense enzymes like peroxidase (PO, polyphenol oxidase (PPO, phenylalanine ammonia-lyase (PAL, and β-1,3 glucanase along with higher accumulation of total phenol, antioxidative enzymes (catalase and ascorbate peroxidase, and total chlorophyll content. Furthermore, the treatment also induced nitric oxide (NO production which was confirmed by realtime visualization of NO burst using a fluorescent probe 4,5-diaminofluorescein diacetate (DAF-2DA and spectrophotometric analysis. The result suggested that the sublethal dose of heavy metal can induce an array of plant defense responses that lead to the improvement of innate immunity in plants.

  11. Methods for pretreating biomass

    Energy Technology Data Exchange (ETDEWEB)

    Balan, Venkatesh; Dale, Bruce E; Chundawat, Shishir; Sousa, Leonardo

    2017-05-09

    A method for pretreating biomass is provided, which includes, in a reactor, allowing gaseous ammonia to condense on the biomass and react with water present in the biomass to produce pretreated biomass, wherein reactivity of polysaccharides in the biomass is increased during subsequent biological conversion as compared to the reactivity of polysaccharides in biomass which has not been pretreated. A method for pretreating biomass with a liquid ammonia and recovering the liquid ammonia is also provided. Related systems which include a biochemical or biofuel production facility are also disclosed.

  12. Recovery capacity of glial progenitors after in vivo fission-neutron or X irradiation: age dependence, fractionation and low-dose-rate irradiations.

    NARCIS (Netherlands)

    Philippo, H.; Winter, E.A.M.; Kogel, A.J. van der; Huiskamp, R.

    2005-01-01

    Previous experiments on the radiosensitivity of O-2A glial progenitors determined for single-dose fission-neutron and X irradiation showed log-linear survival curves, suggesting a lack of accumulation of recovery of sublethal damage. In the present study, we addressed this question and further

  13. The repair of sub-lethal damage and the stimulated repair of potentially lethal damage in Saintpaulia.

    Science.gov (United States)

    Leenhouts, H P; Sijsma, M J; Litwiniszyn, M; Chadwick, K H

    1981-10-01

    The repair of sublethal and potentially lethal damage in stationary resting epidermal cells of Saintpaulia has been investigated. Fractionation experiments reveal an efficient repair of sublethal damage with a half-life of 1.9 hours. No repair of potentially lethal damage was noted when cultivation of the leaves was delayed for 24 hours after irradiation. At delay times of 2, 3 and 4 days some repair of potentially lethal damage has been found. A small pre-dose given 24 hours before a challenging dose improved the cells' chance to regenerate and the improvement has been shown to be compatible with an improved repair of potentially lethal damage induced by X-rays and fast neutrons. It hs been shown that the stimulated repair process takes 12 to 24 hours to develop, is dependent on the size of the pre-dose, has single-hit dose kinetics, and an r.b.e. of 1 for neutrons. With delayed cultivation of 2 days the stimulated repair process leads to an alteration in the shape of the regeneration (survival)-dose relationship which increases the low dose r.b.e. for neutrons from 10 to 35.

  14. Impacts of Sublethal Mercury Exposure on Birds: A Detailed Review.

    Science.gov (United States)

    Whitney, Margaret C; Cristol, Daniel A

    Mercury is a ubiquitous environmental contaminant known to accumulate in, and negatively affect, fish-eating and oceanic bird species, and recently demonstrated to impact some terrestrial songbirds to a comparable extent. It can bioaccumulate to concentrations of >1 μg/g in tissues of prey organisms such as fish and insects. At high enough concentrations, exposure to mercury is lethal to birds. However, environmental exposures are usually far below the lethal concentrations established by dosing studies.The objective of this review is to better understand the effects of sublethal exposure to mercury in birds. We restricted our survey of the literature to studies with at least some exposures >5 μg/g. The majority of sublethal effects were subtle and some studies of similar endpoints reached different conclusions. Strong support exists in the literature for the conclusion that mercury exposure reduces reproductive output, compromises immune function, and causes avoidance of high-energy behaviors. For some endpoints, notably certain measures of reproductive success, endocrine and neurological function, and body condition, there is weak or contradictory evidence of adverse effects and further study is required. There was no evidence that environmentally relevant mercury exposure affects longevity, but several of the sublethal effects identified likely do result in fitness reductions that could adversely impact populations. Overall, 72% of field studies and 91% of laboratory studies found evidence of deleterious effects of mercury on some endpoint, and thus we can conclude that mercury is harmful to birds, and the many effects on reproduction indicate that bird population declines may already be resulting from environmental mercury pollution.

  15. Sublethal effect of neem extract on mediterranean fruit fly adults

    Directory of Open Access Journals (Sweden)

    Márcio Alves Silva

    2013-03-01

    Full Text Available The sublethal effect of extracts of Azadirachta indica on Ceratitis capitata was evaluated. Two pairs of flies were treated in plastic tubes with cotton placed in plastic cages. An artificial diet (hydrolyzed protein + sugar was provided ad libitum. The extracts affected significantly the longevity of C. capitata. The pre-oviposition period were not significantly affected by the extracts. The A. indica branches extracted with dichloromethane (888 ppm affected significantly the fecundity and fertility, reducing the number of eggs laid to approximately 80 % and the egg hatching by 30 % at the 8th day. Therefore, the neem branches extracted with dichloromethane affected the reproduction of C. capitata.

  16. Comparison of Ultrasonic and CO2 Laser Pretreatment Methods on Enzyme Digestibility of Corn Stover

    Directory of Open Access Journals (Sweden)

    Li-Li Zuo

    2012-03-01

    Full Text Available To decrease the cost of bioethanol production, biomass recalcitrance needs to be overcome so that the conversion of biomass to bioethanol becomes more efficient. CO2 laser irradiation can disrupt the lignocellulosic physical structure and reduce the average size of fiber. Analyses with Fourier transform infrared spectroscopy, specific surface area, and the microstructure of corn stover were used to elucidate the enhancement mechanism of the pretreatment process by CO2 laser irradiation. The present work demonstrated that the CO2 laser had potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable bioethanol. The saccharification rate of the CO2 laser pretreatment was significantly higher than ultrasonic pretreatment, and reached 27.75% which was 1.34-fold of that of ultrasonic pretreatment. The results showed the impact of CO2 laser pretreatment on corn stover to be more effective than ultrasonic pretreatment.

  17. Food irradiation

    Energy Technology Data Exchange (ETDEWEB)

    1987-02-28

    A brief article examines the controversy over food irradiation regarding the wholesomeness of irradiated food, its microbiological safety, loss of vitamins and changes in flavour. The benefits of food irradiation are also outlined including the destruction of certain food-borne pathogens and the prolongation of the shelf-life of food by killing pests and delaying the deterioration process.

  18. Sublethal effect of imidacloprid on Solenopsis invicta (Hymenoptera: Formicidae) feeding, digging, and foraging behavior

    Science.gov (United States)

    There is increasing evidence that exposure to neonicotinoid insecticides at sublethal levels impairs colonies of honeybee and other pollinators. Recently, it was found that sublethal contamination with neonicotinoids also affect growth and behavior of ants. In this study, we exposed red imported fi...

  19. Survival rate of honeybee (Apis mellifera) workers after exposure to sublethal concentrations of imidacloprid

    NARCIS (Netherlands)

    Blacquiere, T.

    2010-01-01

    Imidacloprid is a commonly used systemic insecticide which can induce several sublethal effects. Previous research has not shown any increased mortality in bees that were fed with sublethal doses. However, there is very little research conducted with the focus on survival rate of honeybees in the

  20. Toxicokinetic-toxicodynamic modeling of quantal and graded sublethal endpoints: a brief discussion of concepts

    NARCIS (Netherlands)

    Ashauer, R.; Agatz, A.; Albert, C.; Ducrot, V.; Galic, N.G.; Hendriks, J.; Jager, T.; Kretschmann, A.; O'Connor, I.; Rubach, M.N.; Nyman, M.; Schmitt, W.; Stadnicka, J.; Brink, van den P.J.

    2011-01-01

    We report on the advantages and problems of using toxicokinetic-toxicodynamic (TKTD) models for the analysis, understanding, and simulation of sublethal effects. Only a few toxicodynamic approaches for sublethal effects are available. These differ in their effect mechanism and emphasis on linkages

  1. Sublethal effects of cadmium, manganese, lead, zinc and iron on the ...

    African Journals Online (AJOL)

    This study also evaluated the sublethal effects of cadmium, manganese, lead, zinc and iron in plasma samples utilising plasma electrolyte parameters as a biomarker using an albino mice model, M. musculus. Mice were subjected to sublethal concentrations of the selected heavy metals (1/10th of 96 hrLC50). Blood plasma ...

  2. Sublethal Total Body Irradiation Leads to Early Cerebellar Damage and Oxidative Stress

    Science.gov (United States)

    2010-01-01

    1] Diener HC, Ehninger G, Schmidt H, Stab U, Majer K, Marquardt B. Neurologic complications after bone marrow transplantation. Nervenarzt 1991; 62(4...radiation injury and radioprotection. In: Cellular Antioxidant Defense. Chow CK, Ed . Cellular Antioxidant Defense. USA: CRC Press 1988; pp. 163- 189

  3. GREET Pretreatment Module

    Energy Technology Data Exchange (ETDEWEB)

    Adom, Felix K. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Han, Jeongwoo [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division

    2014-09-01

    A wide range of biofuels and biochemicals can be produced from cellulosic biomass via different pretreatment technologies that yield sugars. Process simulations of dilute acid and ammonia fiber expansion pretreatment processes and subsequent hydrolysis were developed in Aspen Plus for four lignocellulosic feedstocks (corn stover, miscanthus, switchgrass, and poplar). This processing yields sugars that can be subsequently converted to biofuels or biochemical. Material and energy consumption data from Aspen Plus were then compiled in a new Greenhouses Gases, Regulated Emissions, and Energy Use in Transportation (GREETTM) pretreatment module. The module estimates the cradle-to-gate fossil energy consumption (FEC) and greenhouse gas (GHG) emissions associated with producing fermentable sugars. This report documents the data and methodology used to develop this module and the cradle-to-gate FEC and GHG emissions that result from producing fermentable sugars.

  4. Microwave and thermal pretreatment as methods for increasing the biogas potential of secondary sludge from municipal wastewater treatment plants

    DEFF Research Database (Denmark)

    Kuglarz, Mariusz; Karakashev, Dimitar Borisov; Angelidaki, Irini

    2013-01-01

    In the present study, the sludge was pretreated with microwave irradiation and low-temperature thermal method, both conducted under the same temperature range (30–100°C). Microwave pretreatment was found to be superior over the thermal treatment with respect to sludge solubilization and biogas...... experiments indicated that pre-treated sludge (microwave irradiation: 900W, temperature: 60–70°C) gave 35% more methane, compared to untreated sludge. Moreover, the results of this study clearly demonstrated that microwave pretreated sludge showed better degree of sanitation....

  5. Sublethal effects of waterborne herbicides in tropical freshwater fish.

    Science.gov (United States)

    Rossi, Stéfani Cibele; Dreyer da Silva, Manuela; Piancini, Laercio Dante Stein; Oliveira Ribeiro, Ciro Alberto; Cestari, Marta Margarete; Silva de Assis, Helena Cristina

    2011-12-01

    The study evaluated the sublethal effects of the herbicides glyphosate (Roundup) and diuron (Hexaron) and the mixture of them, used extremely in agriculture, through biomarkers in fish. The glutathione S-transferase activity increased (74%) and catalase activity decreased (37%) at the higher exposure concentration of Hexaron in comparison to the control group, suggesting an activation of this metabolism route. Membrane damage was observed at the higher exposure of Roundup and in the mixture group compared to the control group, which can be related to the nuclear alterations observed in these exposed groups. The cholinesterase activity was also inhibited (37%) in mixture group compared to the control group and no gill morphology damage was found. The results suggested a potential synergic effect in some analysed parameters.

  6. Fungal pretreatment of lignocellulosic biomass.

    Science.gov (United States)

    Wan, Caixia; Li, Yebo

    2012-01-01

    Pretreatment is a crucial step in the conversion of lignocellulosic biomass to fermentable sugars and biofuels. Compared to thermal/chemical pretreatment, fungal pretreatment reduces the recalcitrance of lignocellulosic biomass by lignin-degrading microorganisms and thus potentially provides an environmentally-friendly and energy-efficient pretreatment technology for biofuel production. This paper provides an overview of the current state of fungal pretreatment by white rot fungi for biofuel production. The specific topics discussed are: 1) enzymes involved in biodegradation during the fungal pretreatment; 2) operating parameters governing performance of the fungal pretreatment; 3) the effect of fungal pretreatment on enzymatic hydrolysis and ethanol production; 4) efforts for improving enzymatic hydrolysis and ethanol production through combinations of fungal pretreatment and physical/chemical pretreatment; 5) the treatment of lignocellulosic biomass with lignin-degrading enzymes isolated from fungal pretreatment, with a comparison to fungal pretreatment; 6) modeling, reactor design, and scale-up of solid state fungal pretreatment; and 7) the limitations and future perspective of this technology. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Equivalency of the quality of sublethal lesions after photons and high-linear energy transfer ion beams.

    Science.gov (United States)

    Furusawa, Yoshiya; Nakano-Aoki, Mizuho; Matsumoto, Yoshitaka; Hirayama, Ryoichi; Kobayashi, Alisa; Konishi, Teruaki

    2017-11-01

    The quality of the sublethal damage (SLD) after irradiation with high-linear energy transfer (LET) ion beams was investigated with low-LET photons. Chinese hamster V79 cells and human squamous carcinoma SAS cells were first exposed to a priming dose of different ion beams at different LETs at the Heavy Ion Medical Accelerator in the Chiba facility. The cells were kept at room temperature and then exposed to a secondary test dose of X-rays. Based on the repair kinetics study, the surviving fraction of cells quickly increased with the repair time, and reached a plateau in 2-3 h, even when cells had received priming monoenergetic high-LET beams or spread-out Bragg peak beams as well as X-ray irradiation. The shapes of the cell survival curves from the secondary test X-rays, after repair of the damage caused by the high-LET irradiation, were similar to those obtained from cells exposed to primary X-rays only. Complete SLD repairs were observed, even when the LET of the primary ion beams was very high. These results suggest that the SLD caused by high-LET irradiation was repaired well, and likewise, the damage caused by the X-rays. In cells where the ion beam had made a direct hit in the core region in an ion track, lethal damage to the domain was produced, resulting in cell death. On the other hand, in domains that had received a glancing hit in the low-LET penumbra region, the SLD produced was completely repaired. © The Author 2017. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

  8. Combination of alkaline and microwave pretreatment for disintegration of meat processing wastewater sludge.

    Science.gov (United States)

    Erden, G

    2013-01-01

    Meat processing wastewater sludge has high organic content but it is very slow to degrade in biological processes. Anaerobic digestion may be a good alternative for this type of sludge when the hydrolysis, known to be the rate-limiting step of biological sludge anaerobic degradation, could be eliminated by disintegration. This investigation deals with disintegration of meat processing wastewater sludge. Microwave (MW) irradiation and combined alkaline pretreatment and MW irradiation were applied to sludge for disintegration purposes. Disintegration performance of the methods was evaluated with disintegration degree based on total and dissolved organic carbon calculations (DD(TOC)), and the solubilization of volatile solids (S(VS)) in the pretreated sludge. Optimum conditions were found to be 140 degrees C and 30 min for MW irradiation using response surface methodology (RSM) and pH = 13 for combined pretreatment. While DD(TOC) was observed as 24.6% and 54.9, S(VS) was determined as 8.54% and 42.5% for MW pretreated and combined pretreated sludge, respectively. The results clearly show that pre-conditioning of sludge with alkaline pretreatment played an important role in enhancing the disintegration efficiency of subsequent MW irradiation. Disintegration methods also affected the anaerobic biodegradability and dewaterability of sludge. An increase of 23.6% in biogas production in MW irradiated sludge was obtained, comparing to the raw sludge at the end of the 35 days of incubation. This increase was observed as 44.5% combined pretreatment application. While MW pretreatment led to a little improvement of the dewatering performance of sludge, in combined pretreatment NaOH deteriorates the sludge dewaterability.

  9. Salidroside protects against premature senescence induced by ultraviolet B irradiation in human dermal fibroblasts.

    Science.gov (United States)

    Mao, G-X; Xing, W-M; Wen, X-L; Jia, B-B; Yang, Z-X; Wang, Y-Z; Jin, X-Q; Wang, G-F; Yan, J

    2015-06-01

    Salidroside, the predominant component of a Chinese herbal medicine, Rhodiola rosea L., becomes an attractive bio-agent due to its multifunction. Although it is well proposed that this herbal medicine may have photoprotective effect according to the folk hearsay, the direct supportive experimental evidences linking the drug with skin ageing have rarely been reported so far. The study was conducted to investigate the photoprotective role of salidrosdie and its related mechanisms in vitro. First, a premature senescence model induced by UVB irradiation (250 mJ cm(-2)) in human dermal fibroblasts (HDFs) was established, and senescent phenotypes were evaluated by cell morphology, cell proliferation, senescence-associated beta-galactosidase (SA-β-gal) activity and cell cycle distribution. Then the photoprotective effect of salidroside was investigated. Cells were pre-treated with various doses of salidroside (1, 5 and 10 μM) followed by the sublethal dosage of UVB exposure and then were harvested for various detections, including senescence-associated phenotypes and molecules, alteration of oxidative stress, matrix metalloproteinase-1 (MMP-1) secretion and inflammatory response. Pre-treatment of salidroside dose dependently reversed the senescent state of HDFs induced by UVB as evidenced by elevated cell viability, decreased SA-β-gal activity and relieving of G1/G0 cell cycle arrest. UVB-induced increased protein expression of cyclin-dependent kinase (CDK) inhibitors p21(WAF) (1) and p16(INK) (4) was also repressed by salidrosdie treatment in a dose-dependent manner. Meanwhile, the increment of malondialdehyde (MDA) level in UVB-irradiated HDFs was inhibited upon salidroside treatment. Additionally, salidroside significantly attenuated UVB-induced synthesis of MMP-1 as well as the production of IL-6 and TNF-α in HDFs. Our data provided the evidences for the protective role of salidroside against UVB-induced premature senescence in HDFs probably via its anti

  10. Irradiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Howe, L.M

    2000-07-01

    There is considerable interest in irradiation effects in intermetallic compounds from both the applied and fundamental aspects. Initially, this interest was associated mainly with nuclear reactor programs but it now extends to the fields of ion-beam modification of metals, behaviour of amorphous materials, ion-beam processing of electronic materials, and ion-beam simulations of various kinds. The field of irradiation damage in intermetallic compounds is rapidly expanding, and no attempt will be made in this chapter to cover all of the various aspects. Instead, attention will be focused on some specific areas and, hopefully, through these, some insight will be given into the physical processes involved, the present state of our knowledge, and the challenge of obtaining more comprehensive understanding in the future. The specific areas that will be covered are: point defects in intermetallic compounds; irradiation-enhanced ordering and irradiation-induced disordering of ordered alloys; irradiation-induced amorphization.

  11. Effects of Sublethal Doses of Imidacloprid on Young Adult Honeybee Behaviour: e0140814

    National Research Council Canada - National Science Library

    Gonalons, Carolina Mengoni; Farina, Walter Marcelo

    2015-01-01

    .... As young adult workers perform in-hive duties that are crucial for colony maintenance and survival, we aimed to assess the effect of sublethal IMI doses on honeybee behaviour during this period...

  12. Effects of Sublethal Doses of Imidacloprid on Young Adult Honeybee Behaviour

    National Research Council Canada - National Science Library

    Mengoni Goñalons, Carolina; Farina, Walter Marcelo

    2015-01-01

    .... As young adult workers perform in-hive duties that are crucial for colony maintenance and survival, we aimed to assess the effect of sublethal IMI doses on honeybee behaviour during this period...

  13. Prospects for Irradiation in Cellulosic Ethanol Production

    Directory of Open Access Journals (Sweden)

    Anita Saini

    2015-01-01

    Full Text Available Second generation bioethanol production technology relies on lignocellulosic biomass composed of hemicelluloses, celluloses, and lignin components. Cellulose and hemicellulose are sources of fermentable sugars. But the structural characteristics of lignocelluloses pose hindrance to the conversion of these sugar polysaccharides into ethanol. The process of ethanol production, therefore, involves an expensive and energy intensive step of pretreatment, which reduces the recalcitrance of lignocellulose and makes feedstock more susceptible to saccharification. Various physical, chemical, biological, or combined methods are employed to pretreat lignocelluloses. Irradiation is one of the common and promising physical methods of pretreatment, which involves ultrasonic waves, microwaves, γ-rays, and electron beam. Irradiation is also known to enhance the effect of saccharification. This review explains the role of different radiations in the production of cellulosic ethanol.

  14. Biomass shock pretreatment

    Science.gov (United States)

    Holtzapple, Mark T.; Madison, Maxine Jones; Ramirez, Rocio Sierra; Deimund, Mark A.; Falls, Matthew; Dunkelman, John J.

    2014-07-01

    Methods and apparatus for treating biomass that may include introducing a biomass to a chamber; exposing the biomass in the chamber to a shock event to produce a shocked biomass; and transferring the shocked biomass from the chamber. In some aspects, the method may include pretreating the biomass with a chemical before introducing the biomass to the chamber and/or after transferring shocked biomass from the chamber.

  15. Impacts of microwave pretreatments on the semi-continuous anaerobic digestion of dairy waste activated sludge.

    Science.gov (United States)

    Uma Rani, R; Adish Kumar, S; Kaliappan, S; Yeom, Icktae; Rajesh Banu, J

    2013-05-01

    Microwave (MW) irradiation is one of the new and possible methods used for pretreating the sludge. Following its use in different fields, this MW irradiation method has proved to be more appropriate in the field of environmental research. In this paper, we focused on the effects of MW irradiation at different intensities on solubilization, biodegradation and anaerobic digestion of sludge from the dairy sludge. The changes in the soluble fractions of the organic matter, the biogas yield, the methane content in the biogas were used as control parameters for evaluating the efficiency of the MW pretreatment. Additionally, the energetic efficiency was also examined. In terms of an energetic aspect, the most economical pretreatment of sludge was at 70% intensity for 12 min irradiation time. At this, COD solubilization, SS reduction and biogas production were found to be 18.6%, 14% and 35% higher than the control, respectively. Not only the increase in biogas production was investigated, excluding protein and carbohydrate hydrolysis was also performed successfully by this microwave pretreatment even at low irradiation energy input. Also, experiments were carried out in semi continuous anaerobic digesters, with 3.5L working volume. Combining microwave pretreatment with anaerobic digestion led to 67%, 64% and 57% of SS reduction, VS reduction and biogas production higher than the control, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Sublethal RNA Oxidation as a Mechanism for Neurodegenerative Disease

    Directory of Open Access Journals (Sweden)

    Mark A. Smith

    2008-05-01

    Full Text Available Although cellular RNA is subjected to the same oxidative insults as DNA and other cellular macromolecules, oxidative damage to RNA has not been a major focus in investigations of the biological consequences of free radical damage. In fact, because it is largely single-stranded and its bases lack the protection of hydrogen bonding and binding by specific proteins, RNA may be more susceptible to oxidative insults than is DNA. Oxidative damage to protein-coding RNA or non-coding RNA will, in turn, potentially cause errors in proteins and/or dysregulation of gene expression. While less lethal than mutations in the genome, such sublethal insults to cells might be associated with underlying mechanisms of several chronic diseases, including neurodegenerative disease. Recently, oxidative RNA damage has been described in several neurodegenerative diseases including Alzheimer disease, Parkinson disease, dementia with Lewy bodies, and prion diseases. Of particular interest, oxidative RNA damage can be demonstrated in vulnerable neurons early in disease, suggesting that RNA oxidation may actively contribute to the onset of the disease. An increasing body of evidence suggests that, mechanistically speaking, the detrimental effects of oxidative RNA damage to protein synthesis are attenuated, at least in part, by the existence of protective mechanisms that prevent the incorporation of the damaged ribonucleotides into the translational machinery. Further investigations aimed at understanding the processing mechanisms related to oxidative RNA damage and its consequences may provide significant insights into the pathogenesis of neurodegenerative and other degenerative diseases and lead to better therapeutic strategies.

  17. Sublethal toxicity and biotransformation of pyrene in Lumbriculus variegatus (Oligochaeta)

    Energy Technology Data Exchange (ETDEWEB)

    Maeenpaeae, K. [Faculty of Biosciences, University of Joensuu, FIN-80101 Joensuu (Finland)], E-mail: kimmo.maenpaa@joensuu.fi; Leppaenen, M.T.; Kukkonen, J.V.K. [Faculty of Biosciences, University of Joensuu, FIN-80101 Joensuu (Finland)

    2009-04-01

    The aim of this work was to study the toxicity and biotransformation of polyaromatic hydrocarbon (PAH) pyrene in the oligochaete aquatic worm, Lumbriculus variegatus. PAHs are ubiquitous environmental pollutants that pose a hazard to aquatic organisms, and metabolizing capability is poorly known in the case of many invertebrate species. To study the toxicity and biotransformation of pyrene, the worm was exposed for 15 days to various concentrations of water-borne pyrene. The dorsal blood vessel pulse rate was used as a sublethal endpoint. Pyrene biotransformation by L. variegatus was studied and the critical body residues (CBR) were estimated for pyrene toxicity. The toxicokinetics of pyrene uptake was evaluated. A combination of radiolabeled ({sup 14}C) and nonlabeled pyrene was used in the exposures, and liquid scintillation counting (LSC) and high-pressure liquid chromatography were employed in both water and tissue residue analyses. The results showed that L. variegatus was moderately able to metabolize pyrene to 1-hydroxypyrene (1-HP), thus demonstrating that the phase-I-like oxidizing enzyme system metabolizes pyrene in L. variegatus. The amount of the 1-HP was 1-2% of the amount of pyrene in the worm tissues. The exposure to pyrene reduced the blood vessel pulse rate significantly (p < 0.05), showing that pyrene had a narcotic effect. The estimated CBRs remained constant during the exposure time, varying from 0.120 to 0.174 mmol pyrene/kg worm wet weight. The bioconcentration factors (BCF) decreased as exposure concentration increased. It was suggested that the increased toxicity of pyrene accounted for the decrease in BCFs by lowering the activity of the organism.

  18. Lignocellulosic Biomass Pretreatment Using AFEX

    Science.gov (United States)

    Balan, Venkatesh; Bals, Bryan; Chundawat, Shishir P. S.; Marshall, Derek; Dale, Bruce E.

    Although cellulose is the most abundant organic molecule, its susceptibility to hydrolysis is restricted due to the rigid lignin and hemicellulose protection surrounding the cellulose micro fibrils. Therefore, an effective pretreatment is necessary to liberate the cellulose from the lignin-hemicellulose seal and also reduce cellulosic crystallinity. Some of the available pretreatment techniques include acid hydrolysis, steam explosion, ammonia fiber expansion (AFEX), alkaline wet oxidation, and hot water pretreatment. Besides reducing lignocellulosic recalcitrance, an ideal pretreatment must also minimize formation of degradation products that inhibit subsequent hydrolysis and fermentation. AFEX is an important pretreatment technology that utilizes both physical (high temperature and pressure) and chemical (ammonia) processes to achieve effective pretreatment. Besides increasing the surface accessibility for hydrolysis, AFEX promotes cellulose decrystallization and partial hemicellulose depolymerization and reduces the lignin recalcitrance in the treated biomass. Theoretical glucose yield upon optimal enzymatic hydrolysis on AFEX-treated corn stover is approximately 98%. Furthermore, AFEX offers several unique advantages over other pretreatments, which include near complete recovery of the pretreatment chemical (ammonia), nutrient addition for microbial growth through the remaining ammonia on pretreated biomass, and not requiring a washing step during the process which facilitates high solid loading hydrolysis. This chapter provides a detailed practical procedure to perform AFEX, design the reactor, determine the mass balances, and conduct the process safely.

  19. Irradiation subassembly

    Science.gov (United States)

    Seim, O.S.; Filewicz, E.C.; Hutter, E.

    1973-10-23

    An irradiation subassembly for use in a nuclear reactor is described which includes a bundle of slender elongated irradiation -capsules or fuel elements enclosed by a coolant tube and having yieldable retaining liner between the irradiation capsules and the coolant tube. For a hexagonal bundle surrounded by a hexagonal tube the yieldable retaining liner may consist either of six segments corresponding to the six sides of the tube or three angular segments each corresponding in two adjacent sides of the tube. The sides of adjacent segments abut and are so cut that metal-tometal contact is retained when the volume enclosed by the retaining liner is varied and Springs are provided for urging the segments toward the center of the tube to hold the capsules in a closely packed configuration. (Official Gazette)

  20. Detection of low numbers of healthy and sub-lethally injured Salmonella enterica in chocolate.

    Science.gov (United States)

    Jasson, Vicky; Baert, Leen; Uyttendaele, Mieke

    2011-02-28

    The capacity to detect low levels of healthy and sub-lethally injured Salmonella enterica cells in chocolate by two alternative rapid detection methods iQ-Check(TM)Salmonella II real-time PCR (Bio-Rad) and VIDAS® Easy SLM (BioMérieux) was assessed and compared with ISO 6579:2005. Chocolate, a low moisture food known to support the survival of Salmonella, was challenged as food matrix. Buffered peptone water (BPW) did not support the recovery of low levels of sub-lethally injured S. enterica independent of the detection method, while BPW supplemented with milk powder enabled detection by the three examined methods. However, inhibition of real-time PCR was observed since for one out of three repetitions of chocolate inoculated with a low number of sub-lethally injured S. enterica cells, no PCR signal was obtained. Therefore, attention should be paid to the enrichment step to avoid false negative results due to the presence of especially sub-lethally injured Salmonella cells in chocolate. An appropriate sample preparation (such as enrichment media and conditions for incubation) remains the key factor for reliable detection including sub-lethally injured cells and should be evaluated, if necessary optimized, for each detection assay. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Effect of melatonin and time of administration on irradiation-induced damage to rat testes

    Directory of Open Access Journals (Sweden)

    G. Take

    2009-07-01

    Full Text Available The effect of ionizing irradiation on testes and the protective effects of melatonin were investigated by immunohistochemical and electron microscopic methods. Eighty-two adult male Wistar rats were divided into 10 groups. The rats in the irradiated groups were exposed to a sublethal irradiation dose of 8 Gy, either to the total body or abdominopelvic region using a 60Co source at a focus of 80 cm away from the skin in the morning or evening together with vehicle (20% ethanol or melatonin administered 24 h before (10 mg/kg, immediately before (20 mg/kg and 24 h after irradiation (10 mg/kg, all ip. Caspace-3 immunoreactivity was increased in the irradiated group compared to control (P < 0.05. Melatonin-treated groups showed less apoptosis as indicated by a considerable decrease in caspace-3 immunoreactivity (P < 0.05. Electron microscopic examination showed that all spermatogenic cells, especially primary spermatocytes, displayed prominent degeneration in the groups submitted to total body and abdominopelvic irradiation. However, melatonin administration considerably inhibited these degenerative changes, especially in rats who received abdominopelvic irradiation. Total body and abdominopelvic irradiation induced identical apoptosis and testicular damage. Chronobiological assessment revealed that biologic rhythm does not alter the inductive effect of irradiation. These data indicate that melatonin protects against total body and abdominopelvic irradiation. Melatonin was more effective in the evening abdominopelvic irradiation and melatonin-treated group than in the total body irradiation and melatonin-treated group.

  2. The radiobiology of laser-driven particle beams: focus on sub-lethal responses of normal human cells

    Science.gov (United States)

    Manti, L.; Perozziello, F. M.; Borghesi, M.; Candiano, G.; Chaudhary, P.; Cirrone, G. A. P.; Doria, D.; Gwynne, D.; Leanza, R.; Prise, K. M.; Romagnani, L.; Romano, F.; Scuderi, V.; Tramontana, A.

    2017-03-01

    Accelerated proton beams have become increasingly common for treating cancer. The need for cost and size reduction of particle accelerating machines has led to the pioneering investigation of optical ion acceleration techniques based on laser-plasma interactions as a possible alternative. Laser-matter interaction can produce extremely pulsed particle bursts of ultra-high dose rates (>= 109 Gy/s), largely exceeding those currently used in conventional proton therapy. Since biological effects of ionizing radiation are strongly affected by the spatio-temporal distribution of DNA-damaging events, the unprecedented physical features of such beams may modify cellular and tissue radiosensitivity to unexplored extents. Hence, clinical applications of laser-generated particles need thorough assessment of their radiobiological effectiveness. To date, the majority of studies have either used rodent cell lines or have focussed on cancer cell killing being local tumour control the main objective of radiotherapy. Conversely, very little data exist on sub-lethal cellular effects, of relevance to normal tissue integrity and secondary cancers, such as premature cellular senescence. Here, we discuss ultra-high dose rate radiobiology and present preliminary data obtained in normal human cells following irradiation by laser-accelerated protons at the LULI PICO2000 facility at Laser Lab Europe, France.

  3. Sublethal effects of some synthetic and botanical insecticides on Bemisia tabaci (Hemiptera: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Esmaeily Saeideh

    2014-07-01

    Full Text Available In addition to direct mortality caused by insecticides, some biological traits of insects may also be affected by sublethal insecticide doses. In this study, we used the age-stage, two-sex life table method to evaluate the sublethal effects of the four synthetic insecticides: abamectin, imidacloprid, diazinon, and pymetrozin as well as the botanical insecticide taken from Calotropis procera (Asclepiadaceae extract, on eggs of the cotton whitefly, Bemisia tabaci (Hem.: Aleyrodidae. The lowest and highest survival rates and oviposition periods were observed in whiteflies treated by diazinon and imidacloprid, respectively. We found significant differences in the net reproductive rate (R0, the intrinsic rate of increase (r, the finite rate of increase (?, and the gross reproductive rate (GRR among different insecticides. Altogether, our results showed that pymetrozin and C. procera induced the most sublethal effects, thus they may be suitable candidates for use in integrated pest management programs of B. tabaci.

  4. Sublethal Dosage of Imidacloprid Reduces the Microglomerular Density of Honey Bee Mushroom Bodies

    Science.gov (United States)

    Peng, Yi-Chan; Yang, En-Cheng

    2016-01-01

    The dramatic loss of honey bees is a major concern worldwide. Previous studies have indicated that neonicotinoid insecticides cause behavioural abnormalities and have proven that exposure to sublethal doses of imidacloprid during the larval stage decreases the olfactory learning ability of adults. The present study shows the effect of sublethal doses of imidacloprid on the neural development of the honey bee brain by immunolabelling synaptic units in the calyces of mushroom bodies. We found that the density of the synaptic units in the region of the calyces, which are responsible for olfactory and visual functions, decreased after being exposed to a sublethal dose of imidacloprid. This not only links a decrease in olfactory learning ability to abnormal neural connectivity but also provides evidence that imidacloprid damages the development of the nervous system in regions responsible for both olfaction and vision during the larval stage of the honey bee. PMID:26757950

  5. Sub-lethal antibiotic treatment leads to multidrug resistance via radical-induced mutagenesis

    Science.gov (United States)

    Kohanski, Michael A.; DePristo, Mark A.; Collins, James J.

    2010-01-01

    Summary Antibiotic resistance arises through mechanisms such as selection of naturally occurring resistant mutants and horizontal gene transfer. Recently, oxidative stress has been implicated as one of the mechanisms whereby bactericidal antibiotics kill bacteria. Here we show that sub-lethal levels of bactericidal antibiotics induce mutagenesis, resulting in heterogeneous increases in the minimum inhibitory concentration for a range of antibiotics, irrespective of the drug target. This increase in mutagenesis correlates with an increase in ROS, and is prevented by the ROS scavenger thiourea and by anaerobic conditions, indicating that sub-lethal concentrations of antibiotics induce mutagenesis by stimulating the production of ROS. We demonstrate that these effects can lead to mutant strains that are sensitive to the applied antibiotic but resistant to other antibiotics. This work establishes a radical-based molecular mechanism whereby sub-lethal levels of antibiotics can lead to multidrug resistance, which has important implications for the widespread use and misuse of antibiotics. PMID:20159551

  6. Sublethal concentrations of ichthyotoxic alga Prymnesium parvum affect rainbow trout susceptibility to viral haemorrhagic septicaemia virus

    DEFF Research Database (Denmark)

    Andersen, Nikolaj Gedsted; Lorenzen, Ellen; Boutrup, Torsten Snogdal

    2016-01-01

    concentrations of the ichthyotoxic alga Prymnesium parvum affect the susceptibility of rainbow trout Oncorhynchus mykiss to viral haemorrhagic septicaemia virus (VHSV). During exposure to sublethal algal concentrations, the fish increased production of mucus on their gills. When fish were exposed to the algae......Ichthyotoxic algal blooms are normally considered a threat to maricultured fish only when blooms reach lethal cell concentrations. The degree to which sublethal algal concentrations challenge the health of the fish during blooms is practically unknown. In this study, we analysed whether sublethal...... for 12 h prior to the addition of virus, a marginal decrease in the susceptibility to VHSV was observed compared to fish exposed to VHSV without algae. If virus and algae were added simultaneously, inclusion of the algae increased mortality by 50% compared to fish exposed to virus only, depending...

  7. Sublethal dietary effects of Microcystis on Sacramento splittail, Pogonichthys macrolepidotus.

    Science.gov (United States)

    Acuña, Shawn; Deng, Dong-Fang; Lehman, Peggy; Teh, Swee

    2012-04-01

    The presence of the toxic cyanobacterium Microcystis in the upper San Francisco Estuary (SFE) since 1999 is a potential but to date an unquantified threat to the health and survival of aquatic organisms, such as fish and zooplankton. The microcystins (MCs) predominantly in the LR-form (MC-LR) contained in Microcystis is hepatotoxic and a potential threat to the fishery. This study was conducted to determine the effects of dietary exposure of the endemic Sacramento splittail, Pogonichthys macrolepidotus in SFE to Microcystis and its toxin, MC-LR. Juvenile splittail (12.59 ± 0.7 g fish(-1)) were exposed to five diets for 28 d with MC-LR obtained from: (1) Microcystis harvested from the SFE and (2) a synthetic purified form of MC-LR. Three of the test diets contained 3.55 (D5), 9.14 (D10) and 17.13 (D20)mg MC-LR kg(-1) from Microcystis. The other two diets contained either purified MC-LR at 3.89 mg MC-LR kg(-1) (D5R) or no MC-LR (D0). The RNA/DNA ratio of fish muscle was significantly lower for all treatments fed test diets containing MC-LR compared to the control diet D0, suggesting Microcystis adversely affected nutritional status. Protein phosphatase 2A expression in the fish from the D5, D10 and D20 treatments were inversely affected by increasing concentrations of MC-LR. Cytoplasmic inclusion bodies and single cell necrosis were more prevalent and greater in severity in the fish exposed to the diets D10 and D20 compared to fish from the D0 treatment and indicate severe liver toxicity in splittail exposed to MC-LR. The sublethal effects on splittail characterized by this study suggest cyanobacterial blooms have the potential to affect splittail nutritional status and health in SFE. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Premature induction of aging in sublethally H2O2-treated young MRC5 fibroblasts correlates with increased glutathione peroxidase levels and resistance to DNA breakage.

    Science.gov (United States)

    Caldini, R; Chevanne, M; Mocali, A; Tombaccini, D; Paoletti, F

    1998-09-15

    Human MRC5 fibroblasts, at different passages in cultures, were used as an in vitro model to assess variations and/or induction of aging parameters under basal conditions or following sublethal oxidative stress by H2O2. DNA sensitivities to oxidatively-induced breakage, rather than basal levels of damaged DNA, were significantly different between cultures at low and high population doubling level (PDL): old cells maintained most of their DNA integrity even at high concentrations of H2O2, while young cells showed more extensive DNA damage which developed in a dose-dependent fashion. However, young cells pretreated with low doses of H2O2 exhibited increased resistance against further oxidative damage to DNA thus reproducing a senescent-like profile of sensitivity. In turn, DNA from old cultures incubated in a NAD precursor-free medium was more prone to H2O2-induced strand breaks mimicking DNA sensitivity of young cells. The extent of oxidatively-induced DNA damage in MRC5 populations correlated inversely with the levels of glutathione peroxidase (GPx) activity that almost doubled when cells passed from the young to the senescent stage. In addition, H2O2-pretreatment of young cells induced an increase in GPx expression approaching old cell values and promoted also the premature appearance of neutral beta-galactosidase activity and decreased c-fos expression upon serum stimulation, both of which were assumed to be characteristic traits of the senescent phenotype.

  9. Vertical transmission of sublethal granulovirus infection in the Indian meal moth, Plodia interpunctella.

    Science.gov (United States)

    Burden, J P; Griffiths, C M; Cory, J S; Smith, P; Sait, S M

    2002-03-01

    Knowledge of the mechanisms of pathogen persistence in relation to fluctuations in host density is crucial to our understanding of disease dynamics. In the case of insect baculoviruses, which are typically transmitted horizontally via a lifestage that can persist outside the host, a key issue that remains to be elucidated is whether the virus can also be transmitted vertically as a sublethal infection. We show that RNA transcripts for the Plodia interpunctella GV granulin gene are present in a high proportion of P. interpunctella insects that survive virus challenge. Granulin is a late-expressed gene that is only transcribed after viral genome replication, its presence thus strongly indicates that viral genome replication has occurred. Almost all insects surviving the virus challenge tested positive for viral RNA in the larval and pupal stage. However, this proportion declined in the emerging adults. Granulin mRNA was also detected in both the ovaries and testes, which may represent a putative mechanism by which reduced fecundity in sublethally affected hosts might be manifested. RNA transcripts were also detected in 60-80% of second-generation larvae that were derived from mating surviving adults, but there was no difference between the sexes, with both males and females capable of transmitting a sublethal infection to their offspring. The data indicate that low-level persistent infection, with at least limited gene expression, can occur in P. interpunctella following survival of a granulovirus challenge. We believe that this is the first demonstration of a persistent, sublethal infection by a baculovirus to be initiated by a sublethal virus dose. We hypothesize that the 'latent' baculovirus infections frequently referred to in the literature may also be low level persistent, sublethal infections resulting from survival from initial baculovirus exposure.

  10. Sublethal Effects of Thiamethoxam on the Demographic Parameters of Myzus persicae (Hemiptera: Aphididae).

    Science.gov (United States)

    Wang, Pan; Zhou, Li-Lin; Yang, Fan; Li, Mang; Liu, Xiao-Ming; Wang, Yong; Lei, Chao-Liang; Si, Sheng-Yun

    2017-08-01

    The green peach aphid, Myzus persicae Sulzer (Hemiptera: Aphididae), is an important sap-sucking pest of many crops, including Chinese cabbage, Brassinca oleracea L. The neonicotinoid insecticide thiamethoxam has been used as an effective insecticide to control M. persicae in cabbage fields. In this study, we assessed the effects of sublethal concentrations of thiamethoxam on demographic parameters of M. persicae. In leaf-dip bioassays, thiamethoxam showed a relatively high toxicity against M. persicae with an LC50 of 6.80 mg liter-1. The duration of the preadult stage was not significantly affected in the sublethal bioassay. Additionally, the longevity and adult preoviposition period were not significantly affected by sublethal thiamethoxam. However, sublethal thiamethoxam significantly increased fecundity (LC10) and prolonged the total preoviposition period (LC40). Consequently, the finite rate of increase (λ) and the intrinsic rate of increase (rm) of aphids exposed to the LC40 were significantly lower than those of control aphids, whereas the net reproductive rate (R0) was higher, and the generation time (T) and the population doubling time (DT) were longer in the treated group. Based on these results, hormesis was induced by sublethal thiamethoxam in M. persicae, with the population growth of M. persicae negatively affected at higher sublethal concentrations of thiamethoxam. Therefore, our study indicated that the possible effects of thiamethoxam on aphids require further study to develop optimized integrated pest management strategies. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Bulk Cutting of Carbon Nanotubes Using Electron Beam Irradiation

    Science.gov (United States)

    Ziegler, Kirk J. (Inventor); Rauwald, Urs (Inventor); Hauge, Robert H. (Inventor); Schmidt, Howard K. (Inventor); Smalley, Richard E. (Inventor); Kittrell, W. Carter (Inventor); Gu, Zhenning (Inventor)

    2013-01-01

    According to some embodiments, the present invention provides a method for attaining short carbon nanotubes utilizing electron beam irradiation, for example, of a carbon nanotube sample. The sample may be pretreated, for example by oxonation. The pretreatment may introduce defects to the sidewalls of the nanotubes. The method is shown to produces nanotubes with a distribution of lengths, with the majority of lengths shorter than 100 tun. Further, the median length of the nanotubes is between about 20 nm and about 100 nm.

  12. Toxicity bioassay and effects of sub-lethal exposure of malathion on ...

    African Journals Online (AJOL)

    Clarias gariepinus were exposed to different concentrations of malathion to determine the 96 h LC50 value and its sub-lethal effects on haematological parameters and biochemical composition were also investigated. The 96 h LC50 value concluded was 8.22 mg/L. Specimens of C. gariepinus were exposed to sub-lethal ...

  13. Sublethal effects of imidacloprid on interactions in a tritrophic system of non-target species.

    Science.gov (United States)

    Uhl, Philipp; Bucher, Roman; Schäfer, Ralf B; Entling, Martin H

    2015-08-01

    Imidacloprid is one of the most used insecticides worldwide, but is highly toxic to non-target arthropods. Effects of sublethal imidacloprid intoxication can potentially propagate in food webs, yet little is known about the impact on non-target populations and communities. We investigated short-term sublethal toxicity of imidacloprid in a tritrophic model system of wild strawberry Fragaria vesca, wood cricket Nemobius sylvestris and nursery web spider Pisaura mirabilis. Strawberries were treated two times with 0mg (control), 1mg (low rate) and 10mg (high rate) of Confidor® WG 70 and crickets were allowed to feed on them. In four lab experiments, we quantified the impact of imidacloprid on leaf damage, growth, behaviour and survival of crickets. The high imidacloprid rate reduced feeding, mass gain, thorax growth and mobility in crickets compared to the control, while mortality was similarly low in all treatments. The low rate reduced mass gain only. Cricket survival of spider predation was higher in the low rate treatment than in the control. Overall, herbivory and predation were reduced at sublethal imidacloprid rates in a non-target organism, three-level food chain, which demonstrates possible propagation of sublethal effects through trophic interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Assessment of chronic sublethal effects of imidacloprid on honey bee colony health

    Science.gov (United States)

    Here we present results of a three-year study to determine the fate of imidacloprid residues in hive matrices and to assess chronic sublethal effects on whole honey bee colonies fed supplemental pollen diet containing imidacloprid at 5, 20 and 100 µg/kg over multiple brood cycles. Various endpoints ...

  15. Effect of sublethal preculturing on the survival of probiotics and metabolite formation in set-yoghurt

    NARCIS (Netherlands)

    Settachaimongkon, S.; Valenberg, van H.J.F.; Winata, V.; Wang, X.; Nout, M.J.R.; Hooijdonk, van A.C.M.; Zwietering, M.H.; Smid, E.J.

    2015-01-01

    The objective of this study was to investigate the effect of preculturing of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp. lactis BB12 under sublethal stress conditions on their survival and metabolite formation in set-yoghurt. Prior to co-cultivation with yoghurt starters in milk,

  16. Sub-lethal effects of neonicitinoids on the alfalfa leafcutter bee, Megachile rotundata

    Science.gov (United States)

    Neonicotinoids are commonly used pesticides in U.S. agriculture. For many beneficial insect species, lethal effects of neonicotinoids are well-documented; however, much less is known about sublethal exposure. The alfalfa leaf cutter bee Megachile rotundata is a managed pollinator that constructs com...

  17. Monitoring colony-level effects of sublethal pesticide exposure on honey bees

    Science.gov (United States)

    The effects of sublethal pesticide exposure to honey bee colonies may be significant but difficult to detect in the field using standard visual assessment methods. Here we describe methods to measure the quantities of adult bees, brood and food resources by weighing hives and hive parts, by photogra...

  18. Physiological stress and ethanol accumulation in tree stems and woody tissues at sublethal temperatures from fire

    Science.gov (United States)

    Rick G. Kelsey; Douglas J. Westlind

    2017-01-01

    The lethal temperature limit is 60 degrees Celsius (°C) for plant tissues, including trees, with lower temperatures causing heat stress. As fire injury increases on tree stems, there is an accompanying rise in tissue ethanol concentrations, physiologically linked to impaired mitochondrial oxidative phosphorylation energy production. We theorize that sublethal tissue...

  19. Sublethal Triclosan Exposure Decreases Susceptibility to Gentamicin and Other Aminoglycosides in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Christensen, Ellen Gerd; Gram, Lone; Kastbjerg, Vicky Gaedt

    2011-01-01

    The human food-borne pathogen Listeria monocytogenes is capable of persisting in food processing plants despite cleaning and sanitation and is likely exposed to sublethal biocide concentrations. This could potentially affect susceptibility of the bacterium to biocides and other antimicrobial agents...

  20. Lethal and sublethal effects of an insect growth regulator, pyriproxyfen, on obliquebanded leafroller (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Sial, Ashfaq A; Brunner, Jay F

    2010-04-01

    The obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae), is one of the most destructive pests of tree fruit in Washington. The development of insecticide resistance in C. rosaceana has led us to explore new management tactics. The use of very low doses of insecticides that have strong sublethal effects represents an environmentally friendly option to improve existing integrated pest management (IPM) strategies. We tested the insect growth regulator pyriproxyfen to determine its lethal and sublethal effects on growth and development of C. rosaceana. A leaf-disk bioassay was used to test seven concentrations of pyriproxyfen ranging from 0 to 30 ppm on fifth-instar C. rosaceana. Male and female larvae were assessed separately for mortality as well as other parameters of growth and development. The LC, values for males and females were 2.4 and 4.8 ppm, respectively. The response to pyriproxyfen was concentration-dependent: only 5-6% of the larvae treated with the highest concentration emerged as morphologically normal adults compared with 86% emergence in the controls. The pupation and adult emergence was significantly delayed at concentrations higher than 1 ppm. The weights of C. rosaceana pupae and adults were significantly increased, whereas fecundity and fertility were significantly reduced at a sublethal concentration of 0.3 ppm. We conclude that both lethal and sublethal effects might exhibit significant impacts on the population dynamics of C. rosaceana in tree fruit orchards treated with low concentrations of pyriproxyfen.

  1. Effects of sub-lethal concentrations of a vegetable oil mill effluent on ...

    African Journals Online (AJOL)

    Effects of sub-lethal concentrations of a vegetable oil mill effluent on growth of Clarius gariepinus. JA Adakole, E Alabi. Abstract. No Abstract. Nigerian Journal of Fisheries Vol. 4 (2) 2007: pp. 182-189. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  2. Effects of IL-10 on systemic inflammatory responses during sublethal primate endotoxemia

    NARCIS (Netherlands)

    van der Poll, T.; Jansen, P. M.; Montegut, W. J.; Braxton, C. C.; Calvano, S. E.; Stackpole, S. A.; Smith, S. R.; Swanson, S. W.; Hack, C. E.; Lowry, S. F.; Moldawer, L. L.

    1997-01-01

    IL-10 protects mice from LPS-induced lethality. To determine the effects of IL-10 on LPS-induced inflammatory responses, six Papio anubis baboons were i.v. injected with a sublethal dose of LPS (Salmonella typhimurium; 500 microg/kg) directly preceded by either human rIL-10 (n = 3, 500 microg/kg) or

  3. Effects of sublethal concentrations of formalin on weight gain in the ...

    African Journals Online (AJOL)

    The African Catfish, Clarias gariepinus, was exposed to various sublethal concentrations (25.0, 12.50, 6.25, 3.125, 1.56 and 0.0 mgl-1) of formalin to investigate their effects on the weight gain of the fish. Decrease in weight gain, directly proportional to the toxicant concentration, was observed in fish exposed to ...

  4. Sublethal effects of chronic lead ingestion in mallard ducks

    Science.gov (United States)

    Finley, M.T.; Dieter, M.P.; Locke, L.N.

    1976-01-01

    Mallard drakes (Anas platyrhynchos) fed 1, 5, or 25 ppm lead nitrate were bled and sacrificed at 3-wk intervals. No mortality occurred, and the pathologic lesions usually associated with lead poisoning were not found. Changes in hematocrit and hemoglobin concentration did not occur. After 3-wk ducks fed 25 ppm lead exhibited a 40% inhibition of blood delta-aminolevulinic acid dehydratase activity that persisted through 12 wk exposure. After 12 wk treatment similar enzyme inhibition was present in the ducks fed 5 ppm lead. At 3 wk there was a small accumulation of lead (less than 1 ppm) in the liver and kidneys of ducks fed 25ppm lead; no further increases occurred throughout the exposure. No significant accumulation of lead occurred the the tibiae or wing bones. Groups of ducks fed 5 and 25 ppm diets for 12 wk were placed on clean feed and examined through a 12 wk posttreatment period. After 3 wk on clean diet delta-aminolevulinic acid dehydratase activity and lead concentrations in the blood had returned to pretreatment levels. Even though lead concentrations in the blood, soft organs and bone were low, a highly significant negative correlation between blood lead and blood enzyme activity was obtained. This enzyme bioassay should provide a sensitive and precise estimate for monitoring lead in the blood for waterflow.

  5. Improving enzymatic hydrolysis of corn stover pretreated by ethylene glycol-perchloric acid-water mixture.

    Science.gov (United States)

    He, Yu-Cai; Liu, Feng; Gong, Lei; Lu, Ting; Ding, Yun; Zhang, Dan-Ping; Qing, Qing; Zhang, Yue

    2015-02-01

    To improve the enzymatic saccharification of lignocellulosic biomass, a mixture of ethylene glycol-HClO4-water (88.8:1.2:10, w/w/w) was used for pretreating corn stover in this study. After the optimization in oil-bath system, the optimum pretreatment temperature and time were 130 °C and 30 min, respectively. After the saccharification of 10 g/L pretreated corn stover for 48 h, the saccharification rate was obtained in the yield of 77.4 %. To decrease pretreatment temperature and shorten pretreatment time, ethylene glycol-HClO4-water (88.8:1.2:10, w/w/w) media under microwave irradiation was employed to pretreat corn stover effectively at 100 °C and 200 W for 5 min. Finally, the recovered hydrolyzates containing glucose obtained from the enzymatic hydrolysis of pretreated corn stovers could be fermented into ethanol efficiently. These results would be helpful for developing a cost-effective pretreatment combined with enzymatic saccharification of cellulosic materials for the production of lignocellulosic ethanol.

  6. Wet autoclave pretreatment for immunohistochemical demonstration of oestrogen receptors in routinely processed breast carcinoma tissue.

    Science.gov (United States)

    Bier, B; Bankfalvi, A; Grote, L; Blasius, S; Ofner, D; Böcker, W; Jasani, B; Schmid, K W

    1995-02-01

    The immunohistochemical demonstration of oestrogen receptor (OR) was performed on 32 randomly selected and routinely processed breast carcinomas after wet autoclave pretreatment of sections. The autoclave method was compared to the OR status found on frozen sections as well as to alternative pretreatment methods such as enzymatic predigestion and microwave irradiation. Using four different monoclonal antibody clones (H222, LH1, CC4-5, 1D5.26), the OR status was evaluated for each of the various pretreatment methods applied. All cases with a high OR content on frozen sections (n = 11) also showed a high OR status on wet autoclave-pretreated paraffin tissues using antibody clones 1D5.26 and CC4-5; in cases with low OR content on frozen sections, no false-negative cases were recorded using only the antibody 1D5.26 neither after wet autoclave nor microwave pretreatment. In addition, with this antibody, OR was detectable after autoclave pretreatment in two cases which were considered to be OR-negative even on frozen sections. When the primary antibody was omitted, no false-positive cases were observed after wet autoclave pretreatment. Thus, in our hands, wet autoclave pretreatment, in combination with the antibody 1D5.26, offers a highly sensitive method for the immunohistochemical demonstration of OR in routinely formalin-fixed, paraffin-embedded sections of breast carcinomas.

  7. RFID tracking of sublethal effects of two neonicotinoid insecticides on the foraging behavior of Apis mellifera.

    Directory of Open Access Journals (Sweden)

    Christof W Schneider

    Full Text Available The development of insecticides requires valid risk assessment procedures to avoid causing harm to beneficial insects and especially to pollinators such as the honeybee Apis mellifera. In addition to testing according to current guidelines designed to detect bee mortality, tests are needed to determine possible sublethal effects interfering with the animal's vitality and behavioral performance. Several methods have been used to detect sublethal effects of different insecticides under laboratory conditions using olfactory conditioning. Furthermore, studies have been conducted on the influence insecticides have on foraging activity and homing ability which require time-consuming visual observation. We tested an experimental design using the radiofrequency identification (RFID method to monitor the influence of sublethal doses of insecticides on individual honeybee foragers on an automated basis. With electronic readers positioned at the hive entrance and at an artificial food source, we obtained quantifiable data on honeybee foraging behavior. This enabled us to efficiently retrieve detailed information on flight parameters. We compared several groups of bees, fed simultaneously with different dosages of a tested substance. With this experimental approach we monitored the acute effects of sublethal doses of the neonicotinoids imidacloprid (0.15-6 ng/bee and clothianidin (0.05-2 ng/bee under field-like circumstances. At field-relevant doses for nectar and pollen no adverse effects were observed for either substance. Both substances led to a significant reduction of foraging activity and to longer foraging flights at doses of ≥0.5 ng/bee (clothianidin and ≥1.5 ng/bee (imidacloprid during the first three hours after treatment. This study demonstrates that the RFID-method is an effective way to record short-term alterations in foraging activity after insecticides have been administered once, orally, to individual bees. We contribute further

  8. TiO2/UV based photocatalytic pretreatment of wheat straw for biogas production

    DEFF Research Database (Denmark)

    Alvarado-Morales, Merlin; Tsapekos, Panagiotis; Awais, Muhammad

    2017-01-01

    The present study deals with the application of an advanced oxidation process combining UV irradiation in the presence of the photocatalyst titanium dioxide (TiO2), as an effective pretreatment method of wheat straw as means for increasing its biodegradability for increased biogas production...

  9. TiO2/UV based photocatalytic pretreatment of wheat straw for biogas production

    DEFF Research Database (Denmark)

    Alvarado-Morales, Merlin; Tsapekos, Panagiotis; Awais, Muhammad

    2017-01-01

    The present study deals with the application of an advanced oxidation process combining UV irradiation in the presence of the photocatalyst titanium dioxide (TiO2), as an effective pretreatment method of wheat straw as means for increasing its biodegradability for increased biogas production by a...

  10. Processes for pretreating lignocellulosic biomass: A review

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, J.D.

    1992-11-01

    This paper reviews existing and proposed pretreatment processes for biomass. The focus is on the mechanisms by which the various pretreatments act and the influence of biomass structure and composition on the efficacy of particular pretreatment techniques. This analysis is used to identify pretreatment technologies and issues that warrant further research.

  11. Pre-treatment technologies for dark fermentative hydrogen production: Current advances and future directions.

    Science.gov (United States)

    Rafieenia, Razieh; Lavagnolo, Maria Cristina; Pivato, Alberto

    2017-05-18

    Hydrogen is regarded as a clean and non-carbon fuel and it has a higher energy content compared to carbon fuels. Dark fermentative hydrogen production from organic wastes is the most promising technology for commercialization among chemical and biological methods. Using mixed microflora is favored in terms of easier process control and substrate conversion efficiencies instead of pure cultures. However, mixed cultures should be first pre-treated in order to select sporulating hydrogen producing bacteria and suppress non-spore forming hydrogen consumers. Various inoculum pre-treatments have been used to enhance hydrogen production by dark fermentation including heat shock, acid or alkaline treatment, chemical inhibition, aeration, irradiation and inhibition by long chain fatty acids. Regarding substrate pre-treatment, that is performed with the aim of enhanced substrate biodegradability, thermal pre-treatment, pH adjustment using acid or base, microwave irradiation, sonication and biological treatment are the most commonly studied technologies. This article reviews the most investigated pre-treatment technologies applied for either inoculum or substrate prior to dark fermentation, the long-term effects of varying pre-treatment methods and the subsequently feasibility of each method for commercialization. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Digestibility of Betung Bamboo Fiber Following Fungal Pretreatment

    Directory of Open Access Journals (Sweden)

    Widya Fatriasari

    2014-10-01

    Full Text Available This research evaluated the effect of fungal pretreatment of betung bamboo fibers and enzymatic- and microwave-assisted hydrolysis on the reducing sugar yield. The enzymatic hydrolysis of the pretreated biomass was carried out with cellulase and 10 and 20 FPU/g of substrate in a shaking incubator at 50 °C and 150 rpm for 48 h. The sulfuric acid concentration used in the microwave-assisted acid hydrolysis was 1.0, 2.5, and 5%, either with or without the addition of activated carbon. Microwave irradiation (330 Watt was applied for 5–12.5 min. The yield of reducing sugar was better with the microwave-assisted acid hydrolysis, and the yield tended to increase with an increase in the irradiation time. Based on the dry weight of the initial biomass (bamboo, pretreatment with 5% inoculum loading resulted in a higher reducing sugar yield (17.06% than with 10% inoculum loading (14.54%. At a 1% acid concentration, the formation of brown compounds decreased, followed by a reduction in the reducing sugar yield. The addition of activated carbon at a 1% acid concentration seemed to be of no benefit with respect to the yield in the microwave-assisted acid hydrolysis. The pretreatment with the 5% inoculum loading for 12.5 min at 1% acid concentration resulted in the highest reducing sugar yield. Under these conditions, the yield was 6.3-fold that of the reducing sugar yield using 20 FPU/g of cellulase. The rate of bamboo hollocellulose hydrolysis reached 22.75% of the maximum theoretical reducing sugar reducing sugar of dry biomass.

  13. Enhanced enzymatic hydrolysis of kenaf core using irradiation and dilute acid

    Science.gov (United States)

    Lee, Byoung-Min; Jeun, Joon-Pyo; Kang, Phil-Hyun

    2017-01-01

    This study was performed to determine the effect of electron beam dose and enzymatic hydrolysis time for production of sugar such as glucose and xylose. After kenaf core was exposed to an irradiation dose that ranged from 0 to 500 kGy, the irradiated kenaf core was treated with a 3% (v/v) sulfuric acid solution using an autoclave for 5 h at 120 °C. The pretreated kenaf core was subsequently subjected to enzymatic hydrolysis at 50 °C in a shaking water bath at 150 rpm for 12, 24, 48, and 72 h. The determined enzyme activity rates were 70 FPU (Celluclast 1.5 L) and 40 CBU (Novozyme-188). The crystallinity index decreased from 50.6% in a non-pretreated kenaf core to 27.7% in kenaf core that was subjected to the two-stage pretreatment at dose of 500 kGy. The sugar yield of the two-stage pretreated kenaf core increased with an increase in irradiation dose. The sugar yield after 72 h of enzymatic hydrolysis was 73.6% at its highest with an irradiation dose of 500 kGy. The enhancement of enzymatic hydrolysis by two-stage pretreatment was more effective than non- and single pretreatment (36.9%, 40.6% and 44.0% in non-pretreatment, electron beam and dilute acid, respectively).

  14. Phytosanitary Irradiation

    Directory of Open Access Journals (Sweden)

    Guy J. Hallman

    2016-01-01

    Full Text Available Phytosanitary treatments disinfest traded commodities of potential quarantine pests. Phytosanitary irradiation (PI treatments use ionizing radiation to accomplish this, and, since their international commercial debut in 2004, the use of this technology has increased by ~10% annually. Generic PI treatments (one dose is used for a group of pests and/or commodities, although not all have been tested for efficacy are used in virtually all commercial PI treatments, and new generic PI doses are proposed, such as 300 Gy, for all insects except pupae and adult Lepidoptera (moths. Fresh fruits and vegetables tolerate PI better than any other broadly used treatment. Advances that would help facilitate the use of PI include streamlining the approval process, making the technology more accessible to potential users, lowering doses and broadening their coverage, and solving potential issues related to factors that might affect efficacy.

  15. Neutron irradiation creep in stainless steel alloys

    Energy Technology Data Exchange (ETDEWEB)

    Schuele, Wolfgang (Commission of the European Union, Institute for Advanced Materials, I-21020 Ispra (Vatican City State, Holy See) (Italy)); Hausen, Hermann (Commission of the European Union, Institute for Advanced Materials, I-21020 Ispra (Vatican City State, Holy See) (Italy))

    1994-09-01

    Irradiation creep elongations were measured in the HFR at Petten on AMCR steels, on 316 CE-reference steels, and on US-316 and US-PCA steels varying the irradiation temperature between 300 C and 500 C and the stress between 25 and 300 MPa. At the beginning of an irradiation a type of primary'' creep stage is observed for doses up to 3-5 dpa after which dose the secondary'' creep stage begins. The primary'' creep strain decreases in cold-worked steel materials with decreasing stress and decreasing irradiation temperature achieving also negative creep strains depending also on the pre-treatment of the materials. These primary'' creep strains are mainly attributed to volume changes due to the formation of radiation-induced phases, e.g. to the formation of [alpha]-ferrite below about 400 C and of carbides below about 700 C, and not to irradiation creep. The secondary'' creep stage is found for doses larger than 3 to 5 dpa and is attributed mainly to irradiation creep. The irradiation creep rate is almost independent of the irradiation temperature (Q[sub irr]=0.132 eV) and linearly dependent on the stress. The total creep elongations normalized to about 8 dpa are equal for almost every type of steel irradiated in the HFR at Petten or in ORR or in EBR II. The negative creep elongations are more pronounced in PCA- and in AMCR-steels and for this reason the total creep elongation is slightly smaller at 8 dpa for these two steels than for the other steels. ((orig.))

  16. Microwave heating: A potential pretreating method for bamboo fiber extraction

    Directory of Open Access Journals (Sweden)

    Fu Jia-Jia

    2017-01-01

    Full Text Available Microwave heating is proposed as a kind of pretreating methods for bamboo fiber extraction. Effect of various processing parameters, e. g. microwave initial-setting power, reaction temperature, irradiation time, and bath ratio (bamboo to water on bamboo powders was studied. Analysis of chemical components indicates that microwave assisted extraction is a mild treating method without obvious change of main constitutes of bamboo. The removal of polysaccharide by microwave treating resulted in loosening the structure and thus benefits hydrolysis of bamboo in subsequent.

  17. A comparative study of the hydrolysis of gamma irradiated lignocelluloses

    Directory of Open Access Journals (Sweden)

    E. Betiku

    2009-06-01

    Full Text Available The effect of high-dose irradiation as a pretreatment method on two common lignocellulosic materials; hardwood (Khaya senegalensis and softwood (Triplochiton scleroxylon were investigated by assessing the potential of cellulase enzyme derived from Aspergillus flavus Linn isolate NSPR 101 to hydrolyse the materials. The irradiation strongly affected the materials, causing the enzymatic hydrolysis to increase by more than 3 fold. Maximum digestibility occurred in softwood at 40kGy dosage of irradiation, while in hardwood it was at 90kGy dosage. The results also showed that, at the same dosage levels (p < 0.05, hardwood was hydrolysed significantly better compared to the softwood.

  18. Preparation of electrodes on cfrp composites with low contact resistance comprising laser-based surface pre-treatment

    KAUST Repository

    Almuhammadi, Khaled Hamdan

    2016-12-29

    Various examples are provided related to the preparation of electrodes on carbon fiber reinforced polymer (CFRP) composites with low contact resistance. Laser-based surface preparation can be used for bonding to CFRP composites. In one example, a method includes preparing a pretreated target area on a CFRP composite surface using laser pulsed irradiation and bonding an electrode to exposed fibers in the pretreated target area. The surface preparation can allow the electrode to have a low contact resistance with the CFRP composite.

  19. Locomotion Inhibition of Cimex lectularius L. Following Topical, Sublethal Dose Application of the Chitin Synthesis Inhibitor Lufenuron

    Directory of Open Access Journals (Sweden)

    Brittany Campbell

    2017-09-01

    Full Text Available To date, few studies have evaluated chitin synthesis inhibitors against bed bugs, although they would provide an alternative mode of action to circumvent insecticide resistance. Acute and sublethal effects of lufenuron were evaluated against two strains of the common bed bug. Combined acute and sublethal effects were used to calculate effective doses. The dose that was effective against 50% of Harlan strain bed bugs was 0.0081% (w/v, and was much higher against Bradenton strain bed bugs (1.11% w/v. Sublethal doses were chosen to determine the effect that leg abnormalities had on pulling force. Both Harlan and Bradenton strain bed bugs had significantly lower locomotion ability (p < 0.0001 following topical application of lufenuron. The observed sublethal effects that limit locomotion could prevent bed bugs from moving within a domicile and taking a blood meal, subsequently reducing a bed bug population over time.

  20. Effects of sublethal exposure to metofluthrin on the fitness of Aedes aegypti in a domestic setting in Cairns, Queensland

    OpenAIRE

    Buhagiar, Tamara S.; Gregor J Devine; Scott A. Ritchie

    2017-01-01

    Background Metofluthrin is highly effective at reducing biting activity in Aedes aegypti. Its efficacy lies in the rapid onset of confusion, knockdown, and subsequent kill of a mosquito. In the field, there are a variety of scenarios that might result in sublethal exposure to metofluthrin, including mosquitoes that are active at the margins of the chemical?s lethal range, brief exposure as mosquitoes fly in and out of treated spaces or decreasing efficacy of the emanators with time. Sublethal...

  1. Sublethal doses of imidacloprid disrupt sexual communication and host finding in a parasitoid wasp

    Science.gov (United States)

    Tappert, Lars; Pokorny, Tamara; Hofferberth, John; Ruther, Joachim

    2017-02-01

    Neonicotinoids are widely used insecticides, but their use is subject of debate because of their detrimental effects on pollinators. Little is known about the effect of neonicotinoids on other beneficial insects such as parasitoid wasps, which serve as natural enemies and are crucial for ecosystem functioning. Here we show that sublethal doses of the neonicotinoid imidacloprid impair sexual communication and host finding in the parasitoid wasp Nasonia vitripennis. Depending on the dose, treated females were less responsive to the male sex pheromone or unable to use it as a cue at all. Courtship behaviour of treated couples was also impeded resulting in a reduction of mating rates by up to 80%. Moreover, treated females were no longer able to locate hosts by using olfactory cues. Olfaction is crucial for the reproductive success of parasitoid wasps. Hence, sublethal doses of neonicotinoids might compromise the function of parasitoid wasps as natural enemies with potentially dire consequences for ecosystem services.

  2. Both genome and cytosol dynamics change in E. coli challenged with sublethal rifampicin

    Science.gov (United States)

    Wlodarski, Michal; Raciti, Bianca; Kotar, Jurij; Cosentino Lagomarsino, Marco; Fraser, Gillian M.; Cicuta, Pietro

    2017-02-01

    While the action of many antimicrobial drugs is well understood at the molecular level, a systems-level physiological response to antibiotics remains largely unexplored. This work considers fluctuation dynamics of both the chromosome and cytosol in Escherichia coli, and their response to sublethal treatments of a clinically important antibiotic, rifampicin. We precisely quantify the changes in dynamics of chromosomal loci and cytosolic aggregates (a rheovirus nonstructural protein known as μNS-GFP), measuring short time-scale displacements across several hours of drug exposure. To achieve this we develop an empirical method correcting for photo-bleaching and loci size effects. This procedure allows us to characterize the dynamic response to rifampicin in different growth conditions, including a customised microfluidic device. We find that sub-lethal doses of rifampicin cause a small but consistent increase in motility of both the chromosomal loci and cytosolic aggregates. Chromosomal and cytosolic responses are consistent with each other and between different growth conditions.

  3. Sublethal effects of spinetoram on the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae).

    Science.gov (United States)

    Wang, Ling; Zhang, Youjun; Xie, Wen; Wu, Qingjun; Wang, Shaoli

    2016-09-01

    The two-spotted spider mite Tetranychus urticae is a serious pest of many agricultural crops and ornamental plants. The sublethal effects of a new chemical, spinetoram, on T. urticae were investigated by treating adult females and eggs with LC10 and LC20 in the laboratory. The data were assessed based on age-stage, two-sex life table analysis. The results showed that T. urticae developmental time from egg to adult was reduced and that fecundity was increased by treatment with LC10 and LC20 of spinetoram. The LC10 and LC20 of spinetoram also increased the intrinsic and finite rate of increase and the net reproductive rate and reduced the mean generation time, egg duration, and larval duration whether eggs or adult females were treated. These laboratory results suggest that sublethal or lethal doses of spinetoram may cause outbreaks of T. urticae. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Sublethal effect of nanosilver on the structure of gill of Caspian roach (Rutilus rutilus caspicus fingerlings

    Directory of Open Access Journals (Sweden)

    Maryam Sharifian

    2013-04-01

    Full Text Available Widespread use of nanosilver can be led the contamination of aquatic environment and impact on living organisms such as fishes. We investigated histopathological changes in the gills tissue of Caspian roach fingerlings after two weeks exposure to sublethal concentrations of nanosilver. Following one and two weeks exposure, necrosis, shortening of secondary lamellae, edema, destruction of epithelial lamella, shortening of secondary lamellae, epithelial lifting and curling of secondary lamellae were observed in gill tissues. This observation showed that exposure to sub-lethal concentrations of nanosilver is caused damages in the gill tissues of Caspian roach. The results demonstrated direct correlation of gill tissue damage and toxin exposure i.e. increasing nanosilver concentration is caused more tissue damage. Hence, histopathological changes of gill can considered as a proper indicator for nanosilver contamination of aquatic environments.

  5. Antioxidant properties of natural substances in irradiated fresh poultry

    Science.gov (United States)

    Mahrour, A.; Lacroix, M.; Nketsa-Tabiri, J.; Calderon, N.; Calderon, R.; Gagnon, M.

    1998-06-01

    This study was undertaken to determine if a combined treatment (marinating in natural plant extracts or vacuum) with irradiation could have a synergistic effect, in order to prevent the lipid oxidation resulting in the development of undesirable flavours. The fresh chicken legs were irradiated at 0,3 and 5 kGy. The fatty acids composition of lipids was identified using gas liquid chromatography. The effect of irradiation treatment combined with a pre-treatment on the fatty acids composition was followed. The day after irradiation, ten panallists were asked to evaluate, using the instruction scaling, the overall appearance, the odor, the flavor and the overall acceptability of the samples. The major fatty acids identified in lipids were oleic acid, palmitic acid, palmitoleic acid and stearic acid. Pre-treatments have a significant effect on linoleic acid (C18:2) and higher fatty acids. The unsaturated fatty acids derived from phospholipids appeared to be more affected by the irradiation dose: however, marinating have better protection on C18:2 derived from phospholipids. The results of sensory evaluation have shown a significant better odor and flavor for the irradiated chicken at 5 kGy than the control. No significant difference have been found between the marinated chicken, the chicken irradiated under vacuum and the control.

  6. Sublethal triclosan exposure decreases susceptibility to gentamicin and other aminoglycosides in Listeria monocytogenes.

    Science.gov (United States)

    Christensen, Ellen G; Gram, Lone; Kastbjerg, Vicky G

    2011-09-01

    The human food-borne pathogen Listeria monocytogenes is capable of persisting in food processing plants despite cleaning and sanitation and is likely exposed to sublethal biocide concentrations. This could potentially affect susceptibility of the bacterium to biocides and other antimicrobial agents. The purpose of the present study was to determine if sublethal biocide concentrations affected antibiotic susceptibility in L. monocytogenes. Exposure of L. monocytogenes strains EGD and N53-1 to sublethal concentrations of Incimaxx DES (containing peroxy acids and hydrogen peroxide) and Triquart Super (containing quaternary ammonium compound) in four consecutive cultures did not alter the frequency of antibiotic-tolerant isolates, as determined by plating on 2× the MIC for a range of antibiotics. Exposure of eight strains of L. monocytogenes to 1 and 4 μg/ml triclosan did not alter triclosan sensitivity. However, all eight strains became resistant to gentamicin (up to 16-fold increase in MIC) after exposure to sublethal triclosan concentrations. Gentamicin-resistant isolates of strains N53-1 and 4446 were also resistant to other aminoglycosides, such as kanamycin, streptomycin, and tobramycin. Gentamicin resistance remained at a high level also after five subcultures without triclosan or gentamicin. Aminoglycoside resistance can be caused by mutations in the target site, the 16S rRNA gene. However, such mutations were not detected in the N53-1-resistant isolates. A combination of gentamicin and ampicillin is commonly used in listeriosis treatment. The triclosan-induced resistance is, hence, of great concern. Further investigations are needed to determine the molecular mechanisms underlying the effect of triclosan.

  7. Sublethal Triclosan Exposure Decreases Susceptibility to Gentamicin and Other Aminoglycosides in Listeria monocytogenes▿

    Science.gov (United States)

    Christensen, Ellen G.; Gram, Lone; Kastbjerg, Vicky G.

    2011-01-01

    The human food-borne pathogen Listeria monocytogenes is capable of persisting in food processing plants despite cleaning and sanitation and is likely exposed to sublethal biocide concentrations. This could potentially affect susceptibility of the bacterium to biocides and other antimicrobial agents. The purpose of the present study was to determine if sublethal biocide concentrations affected antibiotic susceptibility in L. monocytogenes. Exposure of L. monocytogenes strains EGD and N53-1 to sublethal concentrations of Incimaxx DES (containing peroxy acids and hydrogen peroxide) and Triquart Super (containing quaternary ammonium compound) in four consecutive cultures did not alter the frequency of antibiotic-tolerant isolates, as determined by plating on 2× the MIC for a range of antibiotics. Exposure of eight strains of L. monocytogenes to 1 and 4 μg/ml triclosan did not alter triclosan sensitivity. However, all eight strains became resistant to gentamicin (up to 16-fold increase in MIC) after exposure to sublethal triclosan concentrations. Gentamicin-resistant isolates of strains N53-1 and 4446 were also resistant to other aminoglycosides, such as kanamycin, streptomycin, and tobramycin. Gentamicin resistance remained at a high level also after five subcultures without triclosan or gentamicin. Aminoglycoside resistance can be caused by mutations in the target site, the 16S rRNA gene. However, such mutations were not detected in the N53-1-resistant isolates. A combination of gentamicin and ampicillin is commonly used in listeriosis treatment. The triclosan-induced resistance is, hence, of great concern. Further investigations are needed to determine the molecular mechanisms underlying the effect of triclosan. PMID:21746948

  8. Assessment of sublethal effects of methoxyfenozide on oriental fruit Moth (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Borchert, Daniel M; Walgenbach, James F; Kennedy, George G

    2005-06-01

    Sublethal effects of the insect growth regulator methoxyfenozide were examined in oriental fruit moth, Grapholita molesta (Busck), in laboratory and field studies. In laboratory studies, oriental fruit moth larvae reared on diet amended with 0.1 ppm methoxyfenozide developed at the same rate as larvae reared on untreated diet, and paired moths reared as larvae from the same treated or untreated diets exhibited similar fecundity and fertility. Population growth differences over multiple generations were used to examine sublethal effects of methoxyfenozide on population dynamics in the field. Multiple single-tree cages were placed over apple (Malus spp.) trees treated with two applications of methoxyfenozide (70 g [AI] /ha) and nontreated trees. Cages were infested at a single time point with virgin male and female oriental fruit moth adults, and population growth was evaluated by egg counts, shoot infestation, fruit damage, and larval counts over a 12-wk period. Significantly fewer eggs, larvae, and damaged fruit were found on methoxyfenozide-treated compared with nontreated trees in 2001. Observed population differences may have been a result of direct mortality to eggs and larvae of the first generation rather than sublethal effects. In 2002, no differences were observed between treatments, but a heavy rain event shortly after the early infestation impacted the experiment. A late moth release treatment was tested in 2002 to examine the effects of residual methoxyfenozide 55 d after initial application. Significantly fewer eggs were found in the methoxyfenozide treatment compared with the control, but no differences existed among treatments in shoot infestation, percentage of damaged fruit, or larval populations. It was concluded direct mortality of eggs and larvae exposed to methoxyfenozide rather than sublethal effects were most important in reduction of subsequent generations.

  9. Lethal and sub-lethal effects of copper to the african catfish ( clarias ...

    African Journals Online (AJOL)

    Lethal and sub-lethal effects of copper on Clarias gariepinus were studied using a 96-hour static bioassay. Copper (as copper chloride, CuCl2 . H2O) was used to prepare the stock solution from which five standard concentrations 0.0, 1.8, 3.2, 5.6, and 10.0 mg/L were prepared (coded A – E). 15 juvenile C. gariepinus fish ...

  10. Sublethal dose of phoxim and Bombyx mori nucleopolyhedrovirus interact to elevate silkworm mortality.

    Science.gov (United States)

    Gu, ZhiYa; Li, FanChi; Hu, JingSheng; Ding, Chao; Wang, Chaoqian; Tian, JiangHai; Xue, Bin; Xu, KaiZun; Shen, WeiDe; Li, Bing

    2017-03-01

    Silkworm (Bombyx mori) is an economically important insect. It is relatively less resistant to certain chemicals and environment exposures such as pesticides and pathogens. After pesticide exposures, the silkworms are more susceptible to microbial infections. The mechanism underlying the susceptibility might be related to immune response and oxidative stress. A sublethal dose of phoxim combined with Bombyx mori nucleopolyhedrovirus (BmNPV) elevated the silkworm mortality at 96 h. We found a higher content of H2 O2 and increased levels of genes related to oxidative stress and immune response after treatment with a sublethal dose of phoxim for 24 h or 48 h. However, such response decreased with longer pesticide treatment. Mortality increased by 44% when B. mori was exposed to combined treatment with BmNPV and phoxim rather than BmNPV alone. The level of examined immune-related and oxidative-stress-related genes significantly decreased in the combined treatment group compared with the BmNPV group. Our results indicated that, with long-term exposure to pesticides such as OPs, even at sublethal dose, the oxidative stress response and immune responses in silkworm were inhibited, which may lead to further immune impairment and accumulation of oxidative stress, resulting in susceptibility to the virus and harm to the silkworm. Our study provided insights for understanding the susceptibility to pathogen after pesticide exposures, which may promote the development of better pesticide controls to avoid significant economic losses. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  11. Acute toxicity and sublethal effects of fipronil on detoxification enzymes in juvenile zebrafish (Danio rerio).

    Science.gov (United States)

    Wu, Haihua; Gao, Cuie; Guo, Yaping; Zhang, Yuping; Zhang, Jianzhen; Ma, Enbo

    2014-10-01

    The acute toxicity of fipronil and its sublethal effects on detoxification enzymes (carboxylesterases (CarEs), glutathione S-transferases (GSTs), and 7-ethoxycoumarin O-deethylase (ECOD)) in zebrafish (Danio rerio) were investigated. The results indicated that the 24-h LC50 of fipronil for zebrafish was 220.4 μg/L (95% CI: 173.7-272.4 μg/L). Sublethal concentrations of fipronil did not cause significant changes in CarEs activities. In the liver and muscle tissues, GST activities at the tested concentrations did not significantly differ from those in the control. In the brain and gill tissues, GST activities at a concentration of 4 μg/L were significantly lower than those at a concentration of 2 μg/L. The results suggest that CarEs and GSTs were not suitable biomarkers for fipronil effects in D. rerio. A significant induction in the ECOD activities in the brain, gill, liver, and muscle tissues was observed compared with the control. Moreover, the dose-dependent responses of the ECOD activity were observed after treatment with sublethal concentrations of fipronil in the range of 2-20 μg/L. The results suggested that ECOD could be a suitable biomarker of fipronil effects in D. rerio. Copyright © 2014. Published by Elsevier Inc.

  12. Fumigant Toxicity and Sublethal Effects of Artemisia khorassanica and Artemisia sieberi on Sitotroga cerealella (Lepidoptera: Gelechiidae).

    Science.gov (United States)

    Naseri, B; Abedi, Z; Abdolmaleki, A; Jafary-Jahed, M; Borzoui, E; Mozaffar Mansouri, Seyed

    2017-09-01

    Fumigant toxicity and sublethal effects of essential oils from Artemisia khorassanica Podl. and Artemisia sieberi Bess were investigated against adults of Sitotroga cerealella Olivier. To assess the sublethal effects, adult moths were exposed to the LC30 of each essential oil, and life table parameters of the surviving S. cerealella were studied. Higher fumigant toxicity of A. khorassanica (LC50: 7.38 µl/liter air) than A. sieberi (LC50: 9.26 µl/liter air) was observed against S. cerealella. Also, the insecticidal effects of A. khorassanica (LT50: 9.01 h) were faster than A. sieberi (LT50: 14.37 h). A significant extension was observed in the developmental time (egg to adult) of S. cerealella treated with the essential oils. In addition, fecundity of S. cerealella reduced by 25.29 and 35.78% following exposure to sublethal concentrations of A. sieberi and A. khorassanica, respectively. Both tested essential oils caused a significant reduction in the gross and net reproductive rates, intrinsic rate of increase (rm), and finite rate of increase of S. cerealella. The rm values following exposure to A. sieberi, A. khorassanica, and control were 0.098, 0.094, and 0.107 d-1, respectively. The results of this study suggest that tested essential oils have a good potential to apply in integrated pest management of S. cerealella. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  13. Fumigant Toxicity and Sublethal Effects of Artemisia khorassanica and Artemisia sieberi on Sitotroga cerealella (Lepidoptera: Gelechiidae)

    Science.gov (United States)

    Abedi, Z; Abdolmaleki, A; Jafary-Jahed, M; Borzoui, E; Mozaffar Mansouri, Seyed

    2017-01-01

    Abstract Fumigant toxicity and sublethal effects of essential oils from Artemisia khorassanica Podl. and Artemisia sieberi Bess were investigated against adults of Sitotroga cerealella Olivier. To assess the sublethal effects, adult moths were exposed to the LC30 of each essential oil, and life table parameters of the surviving S. cerealella were studied. Higher fumigant toxicity of A. khorassanica (LC50: 7.38 µl/liter air) than A. sieberi (LC50: 9.26 µl/liter air) was observed against S. cerealella. Also, the insecticidal effects of A. khorassanica (LT50: 9.01 h) were faster than A. sieberi (LT50: 14.37 h). A significant extension was observed in the developmental time (egg to adult) of S. cerealella treated with the essential oils. In addition, fecundity of S. cerealella reduced by 25.29 and 35.78% following exposure to sublethal concentrations of A. sieberi and A. khorassanica, respectively. Both tested essential oils caused a significant reduction in the gross and net reproductive rates, intrinsic rate of increase (rm), and finite rate of increase of S. cerealella. The rm values following exposure to A. sieberi, A. khorassanica, and control were 0.098, 0.094, and 0.107 d−1, respectively. The results of this study suggest that tested essential oils have a good potential to apply in integrated pest management of S. cerealella. PMID:29117375

  14. Effect of non-homogenous thermal stress during sub-lethal photodynamic antimicrobial chemotherapy

    Science.gov (United States)

    Gadura, N.; Kokkinos, D.; Dehipawala, S.; Cheung, E.; Sullivan, R.; Subramaniam, R.; Schneider, P.; Tremberger, G., Jr.; Holden, T.; Lieberman, D.; Cheung, T.

    2012-03-01

    Pathogens could be inactivated via a light source coupled with a photosensitizing agent in photodynamic antimicrobial chemotherapy (PACT). This project studied the effect of non-homogenous substrate on cell colony. The non-homogeneity could be controlled by iron oxide nano-particles doping in porous glassy substrates such that each cell would experience tens of hot spots when illuminated with additional light source. The substrate non-homogeneity was characterized by Atomic Force Microscopy, Transmission Electron Microscopy and Extended X-Ray Absorption Fine Structure at Brookhaven Synchrotron Light Source. Microscopy images of cell motion were used to study the motility. Laboratory cell colonies on non-homogenous substrates exhibit reduced motility similar to those observed with sub-lethal PCAT treatment. Such motility reduction on non-homogenous substrate is interpreted as the presence of thermal stress. The studied pathogens included E. coli and Pseudomonas aeruginosa. Non-pathogenic microbes Bacillus subtilis was also studied for comparison. The results show that sub-lethal PACT could be effective with additional non-homogenous thermal stress. The use of non-uniform illumination on a homogeneous substrate to create thermal stress in sub-micron length scale is discussed via light correlation in propagation through random medium. Extension to sub-lethal PACT application complemented with thermal stress would be an appropriate application.

  15. Sublethal effects of some botanical and chemical insecticides on the cotton whitefly, Bemisia tabaci (Hem: Aleyrodidae

    Directory of Open Access Journals (Sweden)

    Fatemeh Jafarbeigi

    2014-09-01

    Full Text Available In addition to direct mortalities caused by acute concentrations of insecticides, some biological traits of target pests may be also affected by sublethal doses. The cotton whitefly, Bemisia tabaci (Hem: Aleyrodidae is an important pest of a wide variety of agricultural crops across the world. The control of B. tabaci largely relies on wide application of chemical insecticides. In this study, we analyzed the life table parameters to evaluate the sublethal effect of three plant-derived insecticides (Fumaria parviflora (Fumariaceae, Teucrium polium (Lamiaceae, and Thymus vulgaris (Lamiaceae and two chemical insecticides (pymetrozin and neemarin on B. tabaci. The whiteflies were allowed to oviposit on plants infected with each of the five insecticides using leaf-dip method. The data were analyzed using the age-stage two-sex life table. We found significant differences in the gross reproductive rate (GRR, the net reproductive rat (R0, the intrinsic rate of increase (r and the finite rate of increase (λ of treated whiteflies compared to control. Our results showed that some biological traits of B. tabaci are affected by sub-lethal doses of the plant-derived extracts and that these effects are comparable to those of chemical insecticides. Given the detrimental effects of chemical insecticides on human, environment and non-target organisms, plant-derived insecticides may provide valuable environmentally friendly tools for pest management programs.

  16. Genetic regulation of allolysis in response to sub-lethal antibiotic stress in Streptococcus pneumoniae

    Directory of Open Access Journals (Sweden)

    MANISHA DASH

    2014-11-01

    Full Text Available Dash M, Dash HR, Das S. 2014. Genetic regulation of allolysis in response to sub-lethal antibiotic stress in Streptococcus pneumoniae. Nusantara Bioscience 6: 111-117. Allolysis is the phenomenon of cell lysis induced by other cells of the same species. Gram-positive bacterium Streptococcus pneumoniae, a major human pathogen exhibits competence induced allolysis that increases the genetic recombination and enhances the virulence. During allolysis, a group of non-competent bacterial cells are lysed by another group of competent cells in the same culture. This process is regulated by com operon as well as bacteriocin. In this study, allolysis was induced in Streptococcus pneumoniae MTCC655 by sub-lethal dose of antibiotic (chloramphenicol and the mechanism of allolysis has been deduced by amplification of lytA, lytC and cbpD genes in the bacterium. The strain was found to be resistant to a number of antibiotics including amoxicillin, cefpodoxime, erythromycin and vancomycin. The early onset of allolysis induction from 7-9 h under normal conditions to 2-3 h by sub-lethal dose of chloramphenicol was observed.

  17. Irradiation Facilities at CERN

    CERN Document Server

    Gkotse, Blerina; Carbonez, Pierre; Danzeca, Salvatore; Fabich, Adrian; Garcia, Alia, Ruben; Glaser, Maurice; Gorine, Georgi; Jaekel, Martin, Richard; Mateu,Suau, Isidre; Pezzullo, Giuseppe; Pozzi, Fabio; Ravotti, Federico; Silari, Marco; Tali, Maris

    2017-01-01

    CERN provides unique irradiation facilities for applications in many scientific fields. This paper summarizes the facilities currently operating for proton, gamma, mixed-field and electron irradiations, including their main usage, characteristics and information about their operation. The new CERN irradiation facilities database is also presented. This includes not only CERN facilities but also irradiation facilities available worldwide.

  18. Irradiation dose detection of irradiated milk powder using visible and near-infrared spectroscopy and chemometrics.

    Science.gov (United States)

    Kong, W W; Zhang, C; Liu, F; Gong, A P; He, Y

    2013-08-01

    The objective of this study was to examine the possibility of applying visible and near-infrared spectroscopy to the quantitative detection of irradiation dose of irradiated milk powder. A total of 150 samples were used: 100 for the calibration set and 50 for the validation set. The samples were irradiated at 5 different dose levels in the dose range 0 to 6.0 kGy. Six different pretreatment methods were compared. The prediction results of full spectra given by linear and nonlinear calibration methods suggested that Savitzky-Golay smoothing and first derivative were suitable pretreatment methods in this study. Regression coefficient analysis was applied to select effective wavelengths (EW). Less than 10 EW were selected and they were useful for portable detection instrument or sensor development. Partial least squares, extreme learning machine, and least squares support vector machine were used. The best prediction performance was achieved by the EW-extreme learning machine model with first-derivative spectra, and correlation coefficients=0.97 and root mean square error of prediction=0.844. This study provided a new approach for the fast detection of irradiation dose of milk powder. The results could be helpful for quality detection and safety monitoring of milk powder. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  19. Relationship between Sublethal Injury and Inactivation of Yeast Cells by the Combination of Sorbic Acid and Pulsed Electric Fields▿

    Science.gov (United States)

    Somolinos, M.; García, D.; Condón, S.; Mañas, P.; Pagán, R.

    2007-01-01

    The objective of this study was to investigate the occurrence of sublethal injury after the pulsed-electric-field (PEF) treatment of two yeasts, Dekkera bruxellensis and Saccharomyces cerevisiae, as well as the relation of sublethal injury to the inactivating effect of the combination of PEF and sorbic acid. PEF caused sublethal injury in both yeasts: more than 90% of surviving D. bruxellensis cells and 99% of surviving S. cerevisiae cells were sublethally injured after 50 pulses at 12 kV/cm in buffer at pHs of both 7.0 and 4.0. The proportion of sublethally injured cells reached a maximum after 50 pulses at 12.0 kV/cm (S. cerevisiae) or 16.5 kV/cm (D. bruxellensis), and it kept constant or progressively decreased at greater electric field strengths and with longer PEF treatments. Sublethally PEF-injured cells showed sensitivity to the presence of sorbic acid at a concentration of 2,000 ppm. A synergistic inactivating effect of the combination of PEF and sorbic acid was observed. Survivors of the PEF treatment were progressively inactivated in the presence of 2,000 ppm of sorbic acid at pH 3.8, with the combined treatments achieving more than log10 5 cycles of dead cells under the conditions investigated. This study has demonstrated the occurrence of sublethal injury after exposure to PEF, so yeast inactivation by PEF is not an all-or-nothing event. The combination of PEF and sorbic acid has proven to be an effective method to achieve a higher level of yeast inactivation. This work contributes to the knowledge of the mechanism of microbial inactivation by PEF, and it may be useful for improving food preservation by PEF technology. PMID:17468278

  20. Relationship between sublethal injury and inactivation of yeast cells by the combination of sorbic acid and pulsed electric fields.

    Science.gov (United States)

    Somolinos, M; García, D; Condón, S; Mañas, P; Pagán, R

    2007-06-01

    The objective of this study was to investigate the occurrence of sublethal injury after the pulsed-electric-field (PEF) treatment of two yeasts, Dekkera bruxellensis and Saccharomyces cerevisiae, as well as the relation of sublethal injury to the inactivating effect of the combination of PEF and sorbic acid. PEF caused sublethal injury in both yeasts: more than 90% of surviving D. bruxellensis cells and 99% of surviving S. cerevisiae cells were sublethally injured after 50 pulses at 12 kV/cm in buffer at pHs of both 7.0 and 4.0. The proportion of sublethally injured cells reached a maximum after 50 pulses at 12.0 kV/cm (S. cerevisiae) or 16.5 kV/cm (D. bruxellensis), and it kept constant or progressively decreased at greater electric field strengths and with longer PEF treatments. Sublethally PEF-injured cells showed sensitivity to the presence of sorbic acid at a concentration of 2,000 ppm. A synergistic inactivating effect of the combination of PEF and sorbic acid was observed. Survivors of the PEF treatment were progressively inactivated in the presence of 2,000 ppm of sorbic acid at pH 3.8, with the combined treatments achieving more than log10 5 cycles of dead cells under the conditions investigated. This study has demonstrated the occurrence of sublethal injury after exposure to PEF, so yeast inactivation by PEF is not an all-or-nothing event. The combination of PEF and sorbic acid has proven to be an effective method to achieve a higher level of yeast inactivation. This work contributes to the knowledge of the mechanism of microbial inactivation by PEF, and it may be useful for improving food preservation by PEF technology.

  1. Pretreatment of Lignocellulosic Wastes to Improve Ethanol and Biogas Production: A Review

    Directory of Open Access Journals (Sweden)

    Keikhosro Karimi

    2008-09-01

    Full Text Available Lignocelluloses are often a major or sometimes the sole components of different waste streams from various industries, forestry, agriculture and municipalities. Hydrolysis of these materials is the first step for either digestion to biogas (methane or fermentation to ethanol. However, enzymatic hydrolysis of lignocelluloses with no pretreatment is usually not so effective because of high stability of the materials to enzymatic or bacterial attacks. The present work is dedicated to reviewing the methods that have been studied for pretreatment of lignocellulosic wastes for conversion to ethanol or biogas. Effective parameters in pretreatment of lignocelluloses, such as crystallinity, accessible surface area, and protection by lignin and hemicellulose are described first. Then, several pretreatment methods are discussed and their effects on improvement in ethanol and/or biogas production are described. They include milling, irradiation, microwave, steam explosion, ammonia fiber explosion (AFEX, supercritical CO2 and its explosion, alkaline hydrolysis, liquid hot-water pretreatment, organosolv processes, wet oxidation, ozonolysis, dilute- and concentrated-acid hydrolyses, and biological pretreatments.

  2. Regulatory T cells in γ irradiation-induced immune suppression.

    Directory of Open Access Journals (Sweden)

    Hugh I McFarland

    Full Text Available Sublethal total body γ irradiation (TBI of mammals causes generalized immunosuppression, in part by induction of lymphocyte apoptosis. Here, we provide evidence that a part of this immune suppression may be attributable to dysfunction of immune regulation. We investigated the effects of sublethal TBI on T cell memory responses to gain insight into the potential for loss of vaccine immunity following such exposure. We show that in mice primed to an MHC class I alloantigen, the accelerated graft rejection T memory response is specifically lost several weeks following TBI, whereas identically treated naïve mice at the same time point had completely recovered normal rejection kinetics. Depletion in vivo with anti-CD4 or anti-CD25 showed that the mechanism involved cells consistent with a regulatory T cell (T reg phenotype. The loss of the T memory response following TBI was associated with a relative increase of CD4+CD25+ Foxp3+ expressing T regs, as compared to the CD8+ T effector cells requisite for skin graft rejection. The radiation-induced T memory suppression was shown to be antigen-specific in that a third party ipsilateral graft rejected with normal kinetics. Remarkably, following the eventual rejection of the first MHC class I disparate skin graft, the suppressive environment was maintained, with markedly prolonged survival of a second identical allograft. These findings have potential importance as regards the immunologic status of T memory responses in victims of ionizing radiation exposure and apoptosis-inducing therapies.

  3. Contact irritant responses of Aedes aegypti Using sublethal concentration and focal application of pyrethroid chemicals.

    Directory of Open Access Journals (Sweden)

    Hortance Manda

    Full Text Available BACKGROUND: Previous studies have demonstrated contact irritant and spatial repellent behaviors in Aedes aegypti following exposure to sublethal concentrations of chemicals. These sublethal actions are currently being evaluated in the development of a push-pull strategy for Ae. aegypti control. This study reports on mosquito escape responses after exposure to candidate chemicals for a contact irritant focused push-pull strategy using varying concentrations and focal application. METHODS: Contact irritancy (escape behavior, knockdown and 24 hour mortality rates were quantified in populations of female Ae. aegypti under laboratory conditions and validated in the field (Thailand and Peru using experimental huts. Evaluations were conducted using varying concentrations and treatment surface area coverage (SAC of three pyrethroid insecticides: alphacypermethrin, lambacyhalothrin and deltamethrin. RESULTS: Under laboratory conditions, exposure of Ae. aegypti to alphacypermethrin using the standard field application rate (FAR resulted in escape responses at 25% and 50% SAC that were comparable with escape responses at 100% SAC. Significant escape responses were also observed at <100% SAC using ½FAR of all test compounds. In most trials, KD and 24 hour mortality rates were higher in mosquitoes that did not escape than in those that escaped. In Thailand, field validation studies indicated an early time of exit (by four hours and 40% increase in escape using ½FAR of alphacypermethrin at 75% SAC compared to a matched chemical-free control. In Peru, however, the maximum increase in Ae. aegypti escape from alphacypermethrin-treated huts was 11%. CONCLUSIONS/SIGNIFICANCE: Results presented here suggest a potential role for sublethal and focal application of contact irritant chemicals in an Ae. aegypti push-pull strategy to reduce human-vector contact inside treated homes. However, the impact of an increase in escape response on dengue virus transmission is

  4. Identification of sublethal toxicants in a BC coastal pulp and paper mill effluent

    Energy Technology Data Exchange (ETDEWEB)

    Eickhoff, C.V.; Pickard, J.; Kinnee, K. [BC Research Inc., Vancouver, BC (Canada); Dwernychuk, W. [Hatfield Consultants Ltd., West Vancouver, BC (Canada); Birkholz, D. [EnviroTest Lab., Edmonton, AB (Canada); Kilback, D. [Pacifica Papers, Powell River, BC (Canada)

    2001-06-01

    BC Research Inc. conducted a toxicity identification evaluation to identify the different compounds comprised in the mill Outfall number 1 effluent. The Environmental Effects Monitoring program had determined that these compounds were responsible for sublethal effects to organisms. Echinoderm species like the sand dollar, Dendraster excentricus Eshscholtz, the purple sea urchin, Stronglyocentrotus purpuratus Stimpson, and the marine algae, Champia parvula had suffered toxicity caused by the mill effluent. The last several Environmental Effects Monitoring testing periods had shown the sublethal toxicity of the Outfall number 1 effluent to echinoderms was very consistent. Based on the high cost and shipping associated with the Champia bioassays, toxicity tests conducted during the peak spawning season of the sea urchin and the non significant difference between the sensitivity of the sand dollar and the purple sea urchin, the purple sea urchin was selected to evaluate the toxicity of the manipulated samples for the tests. The tests conducted were: a baseline toxicity test performed immediately upon receipt of the effluent sample, the pH adjustment filtration test to determine if the toxic compound can be removed using filtration, the pH adjustment aeration test to determine if volatile compounds in the sample are toxic, the pH adjustment solid phase extraction test to determine the level of toxicity from organic compounds and metal chelates that can be removed by solid phase extraction. The results indicated that it seems high molecular weight molecules were responsible for the sublethal toxicity observed. Two different sources could be responsible: lignin derived macromolecules, and polymer compounds used as flocculants and sizing agents. Further testing of the pulp mill effluent to identify the source of the toxic high molecular weight compounds was recommended. 22 refs., 4 tabs., 6 figs.

  5. Manure source and age affect survival of zoonotic pathogens during aerobic composting at sublethal temperatures.

    Science.gov (United States)

    Erickson, Marilyn C; Smith, Chris; Jiang, Xiuping; Flitcroft, Ian D; Doyle, Michael P

    2015-02-01

    Heat is the primary mechanism by which aerobic composting inactivates zoonotic bacterial pathogens residing within animal manures, but at sublethal temperatures, the time necessary to hold the compost materials to ensure pathogen inactivation is uncertain. To determine the influence of the type of nitrogen amendment on inactivation of Salmonella, Listeria monocytogenes, and Escherichia coli O157:H7 in compost mixtures stored at sublethal temperatures, specific variables investigated in these studies included the animal source of the manure, the initial carbon/nitrogen (C:N) ratio of the compost mixture, and the age of the manure. Salmonella and L. monocytogenes were both inactivated more rapidly in chicken and swine compost mixtures stored at 20°C when formulated to an initial C:N ratio of 20:1 compared with 40:1, whereas a C:N ratio did not have an effect on inactivation of these pathogens in cow compost mixtures. Pathogen inactivation was related to the elevated pH of the samples that likely arises from ammonia produced by the indigenous microflora in the compost mixtures. Indigenous microbial activity was reduced when compost mixtures were stored at 30°C and drier conditions (compost mixtures prepared with aged chicken litter compared with fresh chicken litter, whereas E. coli O157:H7 survived to similar extents in compost mixtures prepared with either fresh or aged cow manure. The different responses observed when different sources of manure were used in compost mixtures reveal that guidelines with times required for pathogen inactivation in compost mixtures stored at sublethal temperatures should be dependent on the source of nitrogen, i.e., type of animal manure, present.

  6. Toxicity and Sublethal Effects of Cantharidin on Musca domestica (Diptera: Muscidae).

    Science.gov (United States)

    Yasoob, Hassan; Ali Khan, Hafiz Azhar; Zhang, Yalin

    2017-09-27

    The house fly, Musca domestica L. (Diptera: Muscidae), is a major pest of medical and veterinary importance all over the world. Management efforts for house flies are usually compromised owing to their resistance to many groups of conventional insecticides. Cantharidin, a natural toxin produced by meloid beetles, is a biopesticide with a reported toxicity to some insect pests including house flies. However, the effects of cantharidin on biological and fitness parameters of house flies have not yet been investigated. In the present study, we investigated the toxicity and sublethal effects of cantharidin on biological parameters of house flies for two consecutive generations. The results revealed that the values of LC50, LC25, LC10, and LC2 against house flies were to be 2.45, 1.23, 0.66, and 0.30 mg/liter, respectively. Sublethal effects of these concentrations on the development and reproduction parameters of house flies revealed that cantharidin reduced population growth by affecting pupation rate, adult emergence, and by lengthening developmental time. The female ratio, fecundity, egg hatching, and survival of adult flies were significantly reduced at LC2, LC10, LC25, and LC50 of cantharidin when compared with the control group. Furthermore, the increase in concentration of cantharidin had a significant effect on reducing the mean values of mean relative growth rate, net reproductive rate (Ro), intrinsic rate of natural increase (rm), and biotic potential (bp). In conclusion, the results of this study revealed the toxicity of cantharidin against house flies and the adverse effects of sublethal concentrations on biological parameters which may have positive implications for effective management of house flies. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Sublethal effects on wood frogs chronically exposed to environmentally relevant concentrations of two neonicotinoid insecticides.

    Science.gov (United States)

    Robinson, Stacey A; Richardson, Sarah D; Dalton, Rebecca L; Maisonneuve, France; Trudeau, Vance L; Pauli, Bruce D; Lee-Jenkins, Stacey S Y

    2017-04-01

    Neonicotinoids are prophylactically used globally on a variety of crops, and there is concern for the potential impacts of neonicotinoids on aquatic ecosystems. The intensive use of pesticides on crops has been identified as a contributor to population declines of amphibians, but currently little is known regarding the sublethal effects of chronic neonicotinoid exposure on amphibians. The objective of the present study was to characterize the sublethal effect(s) of exposure to 3 environmentally relevant concentrations (1 μg/L, 10 μg/L, and 100 μg/L) of 2 neonicotinoids on larval wood frogs (Lithobates sylvaticus) using outdoor mesocosms. We exposed tadpoles to solutions of 2 commercial formulations containing imidacloprid and thiamethoxam, and assessed survival, growth, and development. Exposure to imidacloprid at 10 μg/L and 100 μg/L increased survival and delayed completion of metamorphosis compared with controls. Exposure to thiamethoxam did not influence amphibian responses. There was no significant effect of any treatment on body mass or size of the metamorphs. The results suggest that current usage of imidacloprid and thiamethoxam does not pose a threat to wood frogs. However, further assessment of both direct and indirect effects on subtle sublethal endpoints, and the influence of multiple interacting stressors at various life stages, is needed to fully understand the effects of neonicotinoids on amphibians. Environ Toxicol Chem 2017;36:1101-1109. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC. © 2017 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

  8. Busulfan administration produces sublethal effects on somatic tissues and inhibits gametogenesis in Senegalese sole juveniles.

    Science.gov (United States)

    Pacchiarini, T; Olague, E; Sarasquete, C; Cabrita, E

    2014-05-01

    Busulfan, a cytotoxic alkylating agent used for treatment of chronic myeloid leukemia has effects in mammalian germ cells. In fish species, the use of this compound is of special interest in intra and interspecies germ cell transplants. To determine the effects of busulfan in fish a previous range finding experiment was designed. Survival and growth rate of 150-days after hatching (150DAH) Senegalese sole (Solea senegalensis) juveniles was determined. In a second experiment, the effects of a sublethal busulfan dose in fish germ cell depletion and in somatic tissues were analysed. Sublethal effects of several busulfan treatments (B10-10 days after injection, B20-20 days after injection, B20÷-20 days after injection with double injection) were determined in somatic and gonadal tissues. Alterations were registered through histopathological techniques, TUNEL (cell apoptosis) and quantified at molecular level (Q-PCR analyses) using the vasa mRNAs (Ssvasa1-2 and Ssvasa3-4 mRNAs) as molecular markers for germinal cells in Senegalese sole juveniles. Several sublethal effects were observed with 40 mg kg⁻¹ busulfan, a non-lethal dose, such as: pyknosis in liver, increase of melanomacrophage centres and blood stagnation in spleen and interruption of gonadal development. Females were more affected by busulfan treatments than males in terms of germ cell disruption, since a significant decrease in the expression of both Ssvasa1-2 and Ssvasa3-4 markers was found in the gonad of treated females rather than males. At 10 days post-treatment (B10), females already presented a decrease in germ cell proliferation, as confirmed by Q-PCR. Ssvasa expression proved to be a reliable tool for the direct evaluation of the effects of busulfan on Senegalese sole gonadal development, proving that busulfan can be a suitable treatment for causing transient sterility in recipient gonads for germ cell transplantation.

  9. Effect of hydrocolloids and pretreatments on the keeping quality of minced fillets of whiting and cod during frozen storage

    NARCIS (Netherlands)

    Ponte, da D.J.B.

    1986-01-01

    The present study examines the effects of additions of hydrocolloids and pretreatments (precooking and irradiation) on the stability of minced fillets of whiting and cod during frozen storage (-18°C).

    Some hydrocolloids (Xanthan gum, alginates, carboxymethyl celluloses and Iota and Lambda

  10. Ginsan activated the antioxidant defense systems in irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Song, Jie Young; Son, Soo Jung; Ahn, Ji Yeon; Shim, Ji Young; Han, Young Soo; Jung, In Sung; Yun, Yeon Sook [KIRMS Daegu (Korea, Republic of)

    2003-07-01

    Ginsan, a polysaccharide extracted from Panax ginseng, has hematopoietic activity and is also known as a good biological-response modifier. In this investigation, we studied the effects of ginsan on the {gamma}-radiation induced alterations of some antioxidant systems in spleen of Balb/c mice. There are many data that irradiation induces Reactive Oxygen Species (ROS), which plays an important causative role in radiation damage of cell. The level of ROS in cells is regulated by enzymatic and nonenzymatic antioxidant systems. The most powerful ones among them are superoxide dismutases (SODs) catalyzing the dismutation of superoxide anion radical o{sub 2} to H{sub 2}O{sub 2}, catalase deactivating h-2O{sub 2} and reduced glutathion (GSH) detoxifying H{sub 2}O{sub 2} and other ROS> At the 5{sub th} day after sublethal whole body irradiation, splenocytes of irradiated mice expressed only marginally increased levels of Mn-SOD, however, Cu/Zn-SOD, catalase, thioredoxine reductase (TR) and thioredoxine (TRX) mRNA (135% increase compared to control), however, the combination of irradiation with ginsan increased the SODs and GPX production more effectively. In addition to the above results, we obtained the similar data of protein expression. The enzyme activities of SOD, catalase, and GPX of ginsan-treated and irradiated mice were significantly enhanced by 140, 115, 126% respectively, compared with those of irradiated mice. Based on these results, we propose that the induction of antioxidant enzymes of ginsan is at least in part due to its capacity to protect against radiation.

  11. Combination Treatment with Sublethal Ionizing Radiation and the Proteasome Inhibitor, Bortezomib, Enhances Death-Receptor Mediated Apoptosis and Anti-Tumor Immune Attack

    Directory of Open Access Journals (Sweden)

    Ercan Cacan

    2015-12-01

    Full Text Available Sub-lethal doses of radiation can modulate gene expression, making tumor cells more susceptible to T-cell-mediated immune attack. Proteasome inhibitors demonstrate broad anti-tumor activity in clinical and pre-clinical cancer models. Here, we use a combination treatment of proteasome inhibition and irradiation to further induce immunomodulation of tumor cells that could enhance tumor-specific immune responses. We investigate the effects of the 26S proteasome inhibitor, bortezomib, alone or in combination with radiotherapy, on the expression of immunogenic genes in normal colon and colorectal cancer cell lines. We examined cells for changes in the expression of several death receptors (DR4, DR5 and Fas commonly used by T cells for killing of target cells. Our results indicate that the combination treatment resulted in increased cell surface expression of death receptors by increasing their transcript levels. The combination treatment further increases the sensitivity of carcinoma cells to apoptosis through FAS and TRAIL receptors but does not change the sensitivity of normal non-malignant epithelial cells. Furthermore, the combination treatment significantly enhances tumor cell killing by tumor specific CD8+ T cells. This study suggests that combining radiotherapy and proteasome inhibition may simultaneously enhance tumor immunogenicity and the induction of antitumor immunity by enhancing tumor-specific T-cell activity.

  12. Opportunities for utilization of non-conventional energy sources for biomass pretreatment.

    Science.gov (United States)

    Singh, Rawel; Krishna, Bhavya B; Kumar, Jitendra; Bhaskar, Thallada

    2016-01-01

    The increasing concerns over the depletion of fossil resources and its associated geo-political issues have driven the entire world to move toward sustainable forms of energy. Pretreatment is the first step in any biochemical conversion process for the production of valuable fuels/chemicals from lignocellulosic biomass to eliminate the lignin and produce fermentable sugars by hydrolysis. Conventional techniques have several limitations which can be addressed by using them in tandem with non-conventional methods for biomass pretreatment. Electron beam and γ (gamma)-irradiation, microwave and ultrasound energies have certain advantages over conventional source of energy and there is an opportunity that these energies can be exploited for biomass pretreatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Method for pretreating lignocellulosic biomass

    Science.gov (United States)

    Kuzhiyil, Najeeb M.; Brown, Robert C.; Dalluge, Dustin Lee

    2015-08-18

    The present invention relates to a method for pretreating lignocellulosic biomass containing alkali and/or alkaline earth metal (AAEM). The method comprises providing a lignocellulosic biomass containing AAEM; determining the amount of the AAEM present in the lignocellulosic biomass; identifying, based on said determining, the amount of a mineral acid sufficient to completely convert the AAEM in the lignocellulosic biomass to thermally-stable, catalytically-inert salts; and treating the lignocellulosic biomass with the identified amount of the mineral acid, wherein the treated lignocellulosic biomass contains thermally-stable, catalytically inert AAEM salts.

  14. DETECTION OF THERMAL SUBLETHAL INJURY IN ESCHERICHIA COLI VIA THE SELECTIVE MEDIUM PLATING TECHNIQUE: MECHANISMS AND IMPROVEMENTS

    Directory of Open Access Journals (Sweden)

    Laura Espina

    2016-08-01

    Full Text Available In food preservation, the selective medium plating technique (SMPT is commonly used in order to detect and quantify the amount of sublethally injured cells in their bacterial cytoplasmic membranes after inimical treatments. From an applicative point of view, this information is of use in the synergistic combination of different preservation technologies, so that cells that are sublethally injured after one or more processes can end up being entirely inactivated by other hurdle(s. However, little work has been done to explain the reasons for the inability of sublethally injured cells to outgrow in selective agar media (containing the osmolyte NaCl as a selective agent, whereas they are able to grow in non-selective agar media. This research could contribute to explain this technique’s limits. In the present paper, the performance of SMPT on Escherichia coli cells after heat treatments is explored by applying different selective agents in the recovery media, using several mutants lacking factors involved in osmoregulation, and also by examining the integrity of the cytoplasmic membrane. In view of the results, the possibility of a specific toxic effect of Na+ as the main mechanism under SMPT is discarded, and the same level of sublethal injury is detected using KCl instead of NaCl. The synthesis of the osmoprotectant trehalose determined the maximum osmotolerance of intact cells to the selective agents, but was not crucial in the quantification of sublethal injury. Moreover, the extent of sublethal injury detected via SMPT was directly correlated with the physical loss of integrity of the cell membrane as measured with the propidium iodide-exclusion technique when that dye was added before thermal treatments. The present work confirms the adequacy of SMPT as a tool for detecting the occurrence and quantity of sublethally injured cells and thus, for efficiently designing combined preservation treatments. Additionally, we propose the combination

  15. Sublethal and hormesis effects of imidacloprid on the soybean aphid Aphis glycines.

    Science.gov (United States)

    Qu, Yanyan; Xiao, Da; Li, Jinyu; Chen, Zhou; Biondi, Antonio; Desneux, Nicolas; Gao, Xiwu; Song, Dunlun

    2015-04-01

    The soybean aphid, Aphis glycines Matsumura, is a major pest in soybean crop. Current management of this pest relies mainly on insecticides applications, and the neonicotinoid imidacloprid has been proposed as an effective insecticide to control A. glycines in soybean field. Imidacloprid at lethal concentrations not only exerts acute toxicity to A. glycines, but also cause various biological changes when aphids are chronically exposed to lower concentrations. In this study, we assessed the effects of a low-lethal (0.20 mg L(-1)) and two sublethal (0.05 and 0.10 mg L(-1)) imidacloprid concentrations on various A. glycines life history traits. Aphid exposure to 0.20 mg L(-1) imidacloprid caused slower juvenile development, shorter reproductive period, and reduced adult longevity, fecundity and total lifespan. Stimulatory effects, i.e. hormesis, on reproduction and immature development duration were observed in aphids exposed to the lower sublethal imidacloprid concentrations. Consequently, the net reproduction rate (R 0) was significantly higher than in the control aphids. These findings stress the importance of the actual imidacloprid concentration in its toxicological properties on A. glycines. Therefore, our results would be useful for assessing the overall effects of imidacloprid on A. glycines and for optimizing integrated pest management programs targeting this pest.

  16. Gene expression changes in honey bees induced by sublethal imidacloprid exposure during the larval stage.

    Science.gov (United States)

    Wu, Ming-Cheng; Chang, Yu-Wen; Lu, Kuang-Hui; Yang, En-Cheng

    2017-09-01

    Honey bee larvae exposed to sublethal doses of imidacloprid show behavioural abnormalities as adult insects. Previous studies have demonstrated that this phenomenon originates from abnormal neural development in response to imidacloprid exposure. Here, we further investigated the global gene expression changes in the heads of newly emerged adults and observed that 578 genes showed more than 2-fold changes in gene expression after imidacloprid exposure. This information might aid in understanding the effects of pesticides on the health of pollinators. For example, the genes encoding major royal jelly proteins (MRJPs), a group of multifunctional proteins with significant roles in the sustainable development of bee colonies, were strongly downregulated. These downregulation patterns were further confirmed through analyses using quantitative reverse transcription-polymerase chain reaction on the heads of 6-day-old nurse bees. To our knowledge, this study is the first to demonstrate that sublethal doses of imidacloprid affect mrjp expression and likely weaken bee colonies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Macroalgal extracts induce bacterial assemblage shifts and sublethal tissue stress in Caribbean corals.

    Science.gov (United States)

    Morrow, Kathleen M; Ritson-Williams, Raphael; Ross, Cliff; Liles, Mark R; Paul, Valerie J

    2012-01-01

    Benthic macroalgae can be abundant on present-day coral reefs, especially where rates of herbivory are low and/or dissolved nutrients are high. This study investigated the impact of macroalgal extracts on both coral-associated bacterial assemblages and sublethal stress response of corals. Crude extracts and live algal thalli from common Caribbean macroalgae were applied onto the surface of Montastraea faveolata and Porites astreoides corals on reefs in both Florida and Belize. Denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene amplicons was used to examine changes in the surface mucus layer (SML) bacteria in both coral species. Some of the extracts and live algae induced detectable shifts in coral-associated bacterial assemblages. However, one aqueous extract caused the bacterial assemblages to shift to an entirely new state (Lobophora variegata), whereas other organic extracts had little to no impact (e.g. Dictyota sp.). Macroalgal extracts more frequently induced sublethal stress responses in M. faveolata than in P. astreoides corals, suggesting that cellular integrity can be negatively impacted in selected corals when comparing co-occurring species. As modern reefs experience phase-shifts to a higher abundance of macroalgae with potent chemical defenses, these macroalgae are likely impacting the composition of microbial assemblages associated with corals and affecting overall reef health in unpredicted and unprecedented ways.

  18. Histopathological effect of sub-lethal concentration of aluminum phosphide (phostoxin on Clarias gariepinus juveniles

    Directory of Open Access Journals (Sweden)

    Kayode B. Olurin

    Full Text Available Abtsract: The study evaluated the effect of sub-lethal concentration of phostoxin on Clarias gariepinus juveniles. C. gariepinus juveniles belonging to the same cohort (40.1±1.2g; 18.1±1.1cm from a commercial fish farm were randomly placed ten in each of 15 plastic tanks containing 15 liters of water. They were exposed for 96 hrs to three sub-lethal concentrations (treatments of phostoxin (0.125, 0.250, 0.5mg L-1 and a phostoxin free control. At the end of 96 hrs exposure, they were dissected and the tissues need for histopathology removed and fixed in Bouin's fluid. The gill filament exhibited fusion at the secondary lamella that was progressive with concentration. At the highest concentration of exposure, the secondary lamellae showed marked pyknotic and necrotic changes characterized by epithelia detachment. The hepatic tissue showed mild inflammatory changes at lower concentrations while at the highest concentration of exposure there was marked inflammation with observed hydropic degeneration. In the kidney, an inflammatory change was only observed in the interstices at the highest dose of exposure with the convoluted tubules showing partial shrinkage. Phostoxin showed to have significantly caused alterations in cyto-architecture of the gills and to a considerable extent liver and kidney of C. gariepinus.

  19. Effects of Sublethal Concentrations of Insecticides on the Functional Response of Two Mirid Generalist Predators.

    Directory of Open Access Journals (Sweden)

    Angeliki F Martinou

    Full Text Available The use of agrochemicals particularly pesticides, can hamper the effectiveness of natural enemies, causing disruption in the ecosystem service of biological control. In the current study, the effects of the insecticides thiacloprid and chlorantraniliprole on the functional response curves were assessed for two mirid predator nymphs, Macrolophus pygmaeus Rambur and Nesidiocoris tenuis Reuter. In the absence of insecticides, both predators exhibited a type II functional response when feeding on eggs of the moth Ephestia kuehniella. N. tenuis seems to be a more efficient predator than M. pygmaeus, as model estimated handling time was significantly lower for the former than for the latter. Residual exposure of M. pygmaeus to sublethal concentrations of either insecticide was associated with a change in the asymptote but not the type of the functional response curve. Thiacloprid seems to be the least compatible with M. pygmaeus, as it led to both a significant reduction of the attack rate and an increase in handling time. In contrast, chlorantraniliprole exposure significantly increased the handling time, but not the attack rate of the predator. Residual exposure of N. tenuis to sublethal concentrations of either insecticide did not have a significant effect on the type nor the parameters of the functional response model. The results show that pesticide residues that do not have lethal effects on beneficial arthropods can reduce prey consumption depending on predator species and on likely risks associated with toxicity.

  20. Gene expression in Listeria monocytogenes exposed to sublethal concentration of benzalkonium chloride.

    Science.gov (United States)

    Tamburro, Manuela; Ripabelli, Giancarlo; Vitullo, Monia; Dallman, Timothy James; Pontello, Mirella; Amar, Corinne Francoise Laurence; Sammarco, Michela Lucia

    2015-06-01

    In this study, tolerance at sublethal concentration of benzalkonium chloride and transcription levels of mdrL, ladR, lde, sigB and bcrABC genes in Listeria monocytogenes strains were evaluated. Viable cells reduction occurred in 45% of strains and clinical isolates showed lower sensitivity than isolates from foods. An increased transcription of an efflux system encoding gene was found in 60% of strains, and simultaneous mdrL overexpression and ladR underexpression occurred in 30% of isolates. A significant association between reduced benzalkonium chloride activity and both mdrL and sigB overexpression was observed; sigB expression also correlated with both mdrL and ladR genes. The bcrABC gene was only found in six strains, all isolated from foods and sensitive to benzalkonium chloride, and in four strains an underexpression was observed. Disinfection at sublethal concentration was less effective in clinical isolates, and mdrL and sigB expression was significantly affected by disinfection. Further insights are needed to understand the adaptation to benzalkonium chloride and to evaluate whether changes in gene expression could affect the L. monocytogenes virulence traits and persistence in the environment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Using photopigment biomarkers to quantify sub-lethal effects of petroleum pollution on natural phytoplankton assemblages

    Energy Technology Data Exchange (ETDEWEB)

    Swistak, J.; Pinckney, J.; Piehler, M.; Paerl, H. [Univ. of North Carolina, Morehead City, NC (United States). Inst. of Marine Sciences

    1995-12-31

    Although much work has been undertaken to determine the toxicity of petroleum pollutants to phytoplankton, most studies have used pure cultures to monitor growth of selected phytoplankton species. Fewer have considered the net effect on entire microalgal communities. Using high performance liquid chromatography (HPLC) to characterize diagnostic microalgal pigments, the authors were able to simultaneously assess sub-lethal pollutant effects on entire communities as well as on individual phytoplankton functional groups. Incubations of natural water samples with diesel fuel, an important contributor to coastal petroleum pollution, revealed significant changes in photopigments and relative abundance of taxonomic groups at sub-lethal concentrations. Differential rates of change of indicator pigment concentrations suggest a range of sensitivity among phytoplankton groups. In preliminary experiments, cyanobacteria exhibited the greatest overall tolerance to the diesel fuel concentrations tested, while cryptomonads displayed the most sensitivity. The authors are currently evaluating the responses of seasonal phytoplankton populations from 3 sites exposed to varied levels of petroleum pollution. HPLC will be used to characterize phytoplankton populations and to determine if the most abundant groups are also the most tolerant of diesel fuel. Preliminary experiments indicate that diesel fuel pollution may modify the structure and function of phytoplankton communities and subsequently alter the trophodynamics of impacted systems.

  2. Chronic exposure of corals to fine sediments: lethal and sub-lethal impacts.

    Science.gov (United States)

    Flores, Florita; Hoogenboom, Mia O; Smith, Luke D; Cooper, Timothy F; Abrego, David; Negri, Andrew P

    2012-01-01

    Understanding the sedimentation and turbidity thresholds for corals is critical in assessing the potential impacts of dredging projects in tropical marine systems. In this study, we exposed two species of coral sampled from offshore locations to six levels of total suspended solids (TSS) for 16 weeks in the laboratory, including a 4 week recovery period. Dose-response relationships were developed to quantify the lethal and sub-lethal thresholds of sedimentation and turbidity for the corals. The sediment treatments affected the horizontal foliaceous species (Montipora aequituberculata) more than the upright branching species (Acropora millepora). The lowest sediment treatments that caused full colony mortality were 30 mg l(-1) TSS (25 mg cm(-2) day(-1)) for M. aequituberculata and 100 mg l(-1) TSS (83 mg cm(-2) day(-1)) for A. millepora after 12 weeks. Coral mortality generally took longer than 4 weeks and was closely related to sediment accumulation on the surface of the corals. While measurements of damage to photosystem II in the symbionts and reductions in lipid content and growth indicated sub-lethal responses in surviving corals, the most reliable predictor of coral mortality in this experiment was long-term sediment accumulation on coral tissue.

  3. Chronic exposure of corals to fine sediments: lethal and sub-lethal impacts.

    Directory of Open Access Journals (Sweden)

    Florita Flores

    Full Text Available Understanding the sedimentation and turbidity thresholds for corals is critical in assessing the potential impacts of dredging projects in tropical marine systems. In this study, we exposed two species of coral sampled from offshore locations to six levels of total suspended solids (TSS for 16 weeks in the laboratory, including a 4 week recovery period. Dose-response relationships were developed to quantify the lethal and sub-lethal thresholds of sedimentation and turbidity for the corals. The sediment treatments affected the horizontal foliaceous species (Montipora aequituberculata more than the upright branching species (Acropora millepora. The lowest sediment treatments that caused full colony mortality were 30 mg l(-1 TSS (25 mg cm(-2 day(-1 for M. aequituberculata and 100 mg l(-1 TSS (83 mg cm(-2 day(-1 for A. millepora after 12 weeks. Coral mortality generally took longer than 4 weeks and was closely related to sediment accumulation on the surface of the corals. While measurements of damage to photosystem II in the symbionts and reductions in lipid content and growth indicated sub-lethal responses in surviving corals, the most reliable predictor of coral mortality in this experiment was long-term sediment accumulation on coral tissue.

  4. Lethal and sublethal effects of cyantraniliprole on Bactrocera dorsalis (Hendel) (Diptera: Tephritidae).

    Science.gov (United States)

    Zhang, Ruimin; Jang, Eric B; He, Shiyu; Chen, Jiahua

    2015-02-01

    The oriental fruit fly, Bactrocera dorsalis (Hendel), is one of the most globally important insect pests. Studies were conducted with the novel anthranilic diamide insecticide cyantraniliprole to determine its lethal and sublethal effects on B. dorsalis. An ingestion toxicity bioassay showed that cyantraniliprole was active against B. dorsalis, and the 72 h feeding LC50 was 3.22 µg g(-1) in adult diet for a susceptible strain. Sublethal doses of cyantraniliprole (1.30 µg g(-1) adult diet) induced a hormesis effect on B. dorsalis. The mating competitiveness of B. dorsalis treated with cyantraniliprole at 3.27 µg g(-1) adult diet was significantly lower when compared with the controls. The lower dose (1.30 µg g(-1) adult diet) of cyantraniliprole improved the total mating times of both mating pairs in treated groups and also the mating competitiveness of the treated males when compared with the higher dose and controls. Cyantraniliprole-treated females of the mated pairs with the lower dose laid more eggs. On the fifth day, female receptivity in the treated group was significantly reduced when compared with the controls. These results indicate that cyantraniliprole is effective against B. dorsalis. The inhibition and stimulation effect of cyantraniliprole on the adult's mating performance at different concentrations was proved. © 2014 Society of Chemical Industry.

  5. Sublethal Dose of Diazinon Induces Pulmonary Toxicity in Rat: Histopathological Evidence

    Directory of Open Access Journals (Sweden)

    Gholamreza Najafi

    2014-02-01

    Full Text Available Objective: Diazinon (DZ is a widely used contact organophosphorous pesticide with broad spectrum insecticide activity. The extensive use of DZ has caused great concern due to the hazardous side effects on human beings as well as wild and domestic animals. The aim of this study was to investigate the effect of sublethal dose of DZ on rat lung. Material and methods: Seven groups of male Wistar rats were used comprising control and test groups. The control group received corn oil (0.3 ml/day for 60 days by oral gavages. The test groups received DZ at a dose of 60 mg/kg body weight orally for 2, 10, 24, 30, 54 and 60 days, respectively. Results: The histopathological analysis of the lungs in DZ-treated groups revealed congestion on day 2, pulmonary edema and emphysema on day 10, congestion and atelectasia on day 24, infiltration of mononuclear cells on day 30 and pulmonary hemorrhage along with bronchial glands hyperplasia on days 54 and 60. DZ administration also caused a significant decrease in serum cholinesterase activity in a time-dependent manner. Conclusion: These findings indicate that sublethal dose of DZ can induce severe lesions in the lung of rat. [J Interdiscipl Histopathol 2014; 2(1.000: 26-31

  6. Development and application of a sublethal toxicity test to PAH using marine harpacticoid copepods. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fleeger, J.W.; Lotufo, G.R.

    1999-01-01

    This research project was designed to improve the understanding of the acute and sublethal effects of PAHs to benthic invertebrates. Sublethal bioassay protocols for benthic harpacticoid copepods were developed, and two species of harpacticoids were exposed to a range of concentrations of sediment-amended PAHs; the single compounds fluoranthene and phenanthrene as well as a complex mixture (diesel fuel). The harpacticoid copepods Schizopera knabeni and Nitocra lacustris were tested using several bioassay approaches. Reproductive assays, feeding assays and avoidance tests were conducted in addition to lethal tests for S. knabeni. Species-specific differences in sensitivity were detected. Early life history stages were much more sensitive than adults in one species but not in the other. Concentrations of PAH as low as 26 micrograms PAH decreased copepod offspring production, egg hatching success, and embryonic and early-stage development, demonstrating the high sensitivity of life history-related endpoints. In addition, grazing on microalgae was significantly impaired at concentrations as low as 20 micrograms/g PAH after short exposures (<30 h). Finally it was demonstrated that harpacticoids can actively avoid contamination.

  7. Effects of Sublethal Doses of Imidacloprid on Young Adult Honeybee Behaviour

    Science.gov (United States)

    Mengoni Goñalons, Carolina; Farina, Walter Marcelo

    2015-01-01

    Imidacloprid (IMI), a neonicotinoid used for its high selective toxicity to insects, is one of the most commonly used pesticides. However, its effect on beneficial insects such as the honeybee Apis mellifera L is still controversial. As young adult workers perform in-hive duties that are crucial for colony maintenance and survival, we aimed to assess the effect of sublethal IMI doses on honeybee behaviour during this period. Also, because this insecticide acts as a cholinergic-nicotinic agonist and these pathways take part in insect learning and memory processes; we used IMI to assess their role and the changes they suffer along early adulthood. We focused on appetitive behaviours based on the proboscis extension response. Laboratory reared adults of 2 to 10 days of age were exposed to sublethal IMI doses (0.25 or 0.50ng) administered orally or topically prior to behavioural assessment. Modification of gustatory responsiveness and impairment of learning and memory were found as a result of IMI exposure. These outcomes differed depending on age of evaluation, type of exposure and IMI dose, being the youngest bees more sensitive and the highest oral dose more toxic. Altogether, these results imply that IMI administered at levels found in agroecosystems can reduce sensitivity to reward and impair associative learning in young honeybees. Therefore, once a nectar inflow with IMI traces is distributed within the hive, it could impair in-door duties with negative consequences on colony performance. PMID:26488410

  8. Sub-lethal toxicity of chlorpyrifos on Common carp, Cyprinus carpio (Linnaeus, 1758: Biochemical response

    Directory of Open Access Journals (Sweden)

    Mahdi Banaee

    2014-01-01

    Full Text Available Chlorpyrifos, an organophosphate pesticide, is widely used to control pests in agriculture farms and orchards of fruit trees. In this study, the fish were exposed to sub-lethal concentrations of chlorpyrifos which were determined based on numerical value of 96 h LC50. Blood was sampled after 10, 20 and 30 days and biochemical parameters including glucose, total protein, albumin, globulin, triglyceride and cholesterol levels, and aspartate aminotransferase (AST, alanine aminotransferase (ALT, lactate dehydrogenase (LDH, creatine kinase (CK, alkaline phosphatase (ALP and acetylcholinsetrase (AChE activities were measured. Behavioral changes in the fish were also recorded during the experiment. Unbalanced swimming, swimming in the surface water and hyperglycemia, increased blood triglyceride, and increased levels of AST, LDH and CK activities as well as decreased levels of AChE activity were important changes that were observed in the specimens exposed to chlorpyrifos during experimental periods. The most important alterations in the blood biochemical parameters were measured in the specimens exposed to 40 µg/L chlorpyrifos on the 20th and 30th day of the trial. In conclusion, results of the present study indicated that exposure to sub-lethal concentrations of chlorpyrifos as low as 40 µg/L may cause biochemical and behavioral changes in Cyprinus carpio.

  9. Molecular Genetic Analysis of Human Endometrial Mesenchymal Stem Cells That Survived Sublethal Heat Shock

    Directory of Open Access Journals (Sweden)

    A. E. Vinogradov

    2017-01-01

    Full Text Available High temperature is a critical environmental and personal factor. Although heat shock is a well-studied biological phenomenon, hyperthermia response of stem cells is poorly understood. Previously, we demonstrated that sublethal heat shock induced premature senescence in human endometrial mesenchymal stem cells (eMSC. This study aimed to investigate the fate of eMSC-survived sublethal heat shock (SHS with special emphasis on their genetic stability and possible malignant transformation using methods of classic and molecular karyotyping, next-generation sequencing, and transcriptome functional analysis. G-banding revealed random chromosome breakages and aneuploidy in the SHS-treated eMSC. Molecular karyotyping found no genomic imbalance in these cells. Gene module and protein interaction network analysis of mRNA sequencing data showed that compared to untreated cells, SHS-survived progeny revealed some difference in gene expression. However, no hallmarks of cancer were found. Our data identified downregulation of oncogenic signaling, upregulation of tumor-suppressing and prosenescence signaling, induction of mismatch, and excision DNA repair. The common feature of heated eMSC is the silence of MYC, AKT1/PKB oncogenes, and hTERT telomerase. Overall, our data indicate that despite genetic instability, SHS-survived eMSC do not undergo transformation. After long-term cultivation, these cells like their unheated counterparts enter replicative senescence and die.

  10. The role of sublethal effects in evaluating earthworm responses to soil contamination

    Energy Technology Data Exchange (ETDEWEB)

    Wilborn, D.; Bollman, M.; Linder, G. [ManTech Environmental Technology, Inc., Corvallis, OR (United States)

    1994-12-31

    Frequently, standard test methods rely upon relatively straightforward, easily interpreted endpoints to evaluate biological effects, like growth inhibition, gross morbidity or death. In soil contamination evaluations, for example, earthworm toxicity tests are routinely completed in order to consider adverse biological effects associated with exposures to soil samples in the laboratory or field. Here, the toxicity endpoint measured in the standard test using Eisenia foetida is death; however, if chronic effects are more appropriate to the questions being asked within a risk assessment context, then alternative test endpoints must be developed and standardized. Prior evaluations have relied upon sublethal endpoints, most frequently behavioral and morphological observations, for evaluating chronic effects associated with contaminant exposures. The authors applied these behavioral and morphological endpoints in analyzing potential chronic effects in earthworms exposed to heavy metal-contaminated soils in both the laboratory and field. In using a relatively standard set of these sublethal endpoints the authors found that these endpoints could be used to evaluate chronic effects associated with soil exposures, but that selection of the specific end-points had to be adequately standardized and that observer bias had to be adequately characterized in order for these measures of chronic effects to be unequivocally applied within an ecological risk assessment.

  11. Lethal and sublethal effects of four essential oils on the egg parasitoids Trissolcus basalis.

    Science.gov (United States)

    Werdin González, Jorge Omar; Laumann, Raúl Alberto; da Silveira, Samantha; Moraes, Maria Carolina Blassioli; Borges, Miguel; Ferrero, Adriana Alicia

    2013-07-01

    The essential oils from leaves of Schinus molle var. areira, Aloysia citriodora, Origanum vulgare and Thymus vulgaris have showed potential as phytoinsecticides against the green stink bug, Nezara viridula. In this work were evaluated their toxicological and behavioral effects on the parasitoid Trissolcus basalis, a biological control agent of this pest insect. Essential oils were obtained via hydrodestillation from fresh leaves. Insecticide activity in T. basalis females was evaluated in direct contact and fumigation bioassays. Behavioral effects were evaluated in olfactometer bioassays. To evaluate the residual toxicity, females of the parasitoids were exposed to oil residues; in these insects, the sublethal effects were evaluated (potential parasitism and survivorship of immature stages). The essential oils from O. vulgare and T. vulgaris proved to be highly selective when used as fumigant and did not change parasitoid behavior. After one week, the residues of these oils were harmless and did not show sublethal effects against T. basalis. According with these results, essential oils have potential applications for the integrated management of N. viridula. Published by Elsevier Ltd.

  12. Immunotherapy with BCG cell wall plus irradiated tumor cells

    Energy Technology Data Exchange (ETDEWEB)

    Mizukuro, Tomoyuki (Kyoto Prefectural Univ. of Medicine (Japan))

    1983-04-01

    Two different fibrosarcomas (MCB-I, MCB-II) were induced by methylcholcholanthrene in syngeneic Balb/C mice were used. The tumor cells irradiated with 5,000 to 30,000 rads did not growth in mice on 30 days after inoculation. The viable tumor cells were challenged intradermally to mice on 7 days after inoculation of the tumor cells irradiated with 5,000 to 30,000 rads. The challenged tumor cells were all rejected at 30 days after inoculation. Mice were challenged with 5 x 10/sup 5/ viable tumor cells on 7 days after inoculation of 10/sup 3/ to 10/sup 8/ irradiated tumor cells. Mice pretreated with 10/sup 5/ or 10/sup 6/ irradiated tumor cells rejected the tumor cells completely. The viable tumor cells were challenged to mice on 7 days after inoculation of BCG-CW emulsion plus 10/sup 6/ irradiated tumor cells. 0, 50, 100, 200, and 400 mu g of BCG-CW emulsion were mixed in 10/sup 6/ irradiated tumor cells. Optimal dosage of BCG-CW emulsion was 50 or 100 mu g. BCG-CW emulsion plus irradiated tumor cells were injected subcutaneously to the mice after tumor cells inoculation. Three injections of the vaccine significantly suppressed the tumor outgrowth, but not one or two injections in no-treated mice. However, in the mice pretreated with BCG-CW emulsion, the tumor growth was significantly suppressed by one or two injections of the vaccine. Especially, the three injections of the vaccine significantly suppressed the tumor growth and the 25% of the mice were completely cured. The effect of the vaccine was almost the same grade by contralateral or ipsilateral treatment. The irradiated MCB-II tumor cells plus BCG-CW emulsion were not effective to the MCB-1 tumor bearing mice, suggesting the anti-tumor effect of this vaccine was immunologically specific.

  13. Hydrolysis of Straw in Ionic Liquids with Acid as Catalyst under Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Yuanjing Zhang

    2015-01-01

    Full Text Available With ionic liquids as solvents and corn straw as raw material, different processes of lignocellulose pretreatment with acid as catalyst were studied under conventional heating/microwave irradiation and the reducing sugar was measured. The results indicated that acid can accelerate hydrolysis reaction of corn straw into reducing sugar with ionic liquids as solvent, and microwave irradiation was more efficient in pretreatment of corn straw than conventional heating. The influences of different acid catalysts, the concentration of acid, temperature, mass ratio of straw/[Bmim]Cl, and the amount of refill water were mainly tested, and the optimum experimental conditions are thus determined.

  14. Influence of amino acids Shiff bases on irradiated DNA stability in vivo.

    Science.gov (United States)

    Karapetyan, N H; Malakyan, M H; Bajinyan, S A; Torosyan, A L; Grigoryan, I E; Haroutiunian, S G

    2013-01-01

    To reveal protective role of the new Mn(II) complexes with Nicotinyl-L-Tyrosinate and Nicotinyl-L-Tryptophanate Schiff Bases against ionizing radiation. The DNA of the rats liver was isolated on 7, 14, and 30 days after X-ray irradiation. The differences between the DNA of irradiated rats and rats pre-treated with Mn(II) complexes were studied using the melting, microcalorimetry, and electrophoresis methods. The melting parameters and the melting enthalpy of rats livers DNA were changed after the X-ray irradiation: melting temperature and melting enthalpy were decreased and melting interval was increased. These results can be explained by destruction of DNA molecules. It was shown that pre-treatment of rats with Mn(II) complexes approximates the melting parameters to norm. Agarose gel electrophoresis data confirmed the results of melting studies. The separate DNA fragments were revealed in DNA samples isolated from irradiated animals. The DNA isolated from animals pre-treated with the Mn(II) chelates had better electrophoretic characteristics, which correspond to healthy DNA. Pre-treatment of the irradiated rats with Mn(II)(Nicotinil-L-Tyrosinate) and Mn(II)(Nicotinil-L-Tryptophanate)2 improves the DNA characteristics.

  15. Pretreatment and Membrane Hydrophilic Modification to Reduce Membrane Fouling

    Directory of Open Access Journals (Sweden)

    Huaqiang Chu

    2013-09-01

    Full Text Available The application of low pressure membranes (microfiltration/ultrafiltration has undergone accelerated development for drinking water production. However, the major obstacle encountered in its popularization is membrane fouling caused by natural organic matter (NOM. This paper firstly summarizes the two factors causing the organic membrane fouling, including molecular weight (MW and hydrophilicity/hydrophobicity of NOM, and then presents a brief introduction of the methods which can prevent membrane fouling such as pretreatment of the feed water (e.g., coagulation, adsorption, and pre-oxidation and membrane hydrophilic modification (e.g., plasma modification, irradiation grafting modification, surface coating modification, blend modification, etc.. Perspectives of further research are also discussed.

  16. Pretreatment of the macroalgae Chaetomorpha linum for the production of bioethanol - Comparison of five pretreatment technologies

    DEFF Research Database (Denmark)

    Schultz-Jensen, Nadja; Thygesen, Anders; Thomsen, Sune Tjalfe

    2013-01-01

    A qualified estimate for pretreatment of the macroalgae Chaetomorpha linum for ethanol production was given, based on the experience of pretreatment of land-based biomass. C. linum was subjected to hydrothermal pretreatment (HTT), wet oxidation (WO), steam explosion (STEX), plasma-assisted pretre...

  17. Comparison of the Effects of Thermal Pretreatment, Steam Explosion and Ultrasonic Disintegration on Digestibility of Corn Stover

    Directory of Open Access Journals (Sweden)

    Andras Dallos

    2016-06-01

    Full Text Available The energy demand of the corn-based bioethanol production could be reduced using the agricultural byproducts as bioenergy feedstock for biogas digesters. The release of lignocellulosic material and therefore the acceleration of degradation processes can be achieved using thermal and mechanical pretreatments, which assist to hydrolyze the cell walls and speed the solubilization of biopolymers in biogas feedstock. This study is focused on liquid hot water, steam explosion and ultrasonic pretreatments of corn stover. The scientific contribution of this paper is a comprehensive comparison of the performance of the pretreatments by fast analytical, biochemical, anaerobic digestibility and biomethane potential tests, extended by energy consumptions and energy balance calculations.The effectiveness of pretreatments was evaluated by means of soluble chemical oxygen demand, biochemical oxygen demand and by the biogas and methane productivities. The results have shown that the thermal pretreatment, steam explosion and ultrasonic irradiation of biogas feedstock disintegrated the lignocellulosic structure, increased and accelerated the methane production and increased the cumulative biogas and methane productivity of corn stover in reference to the control during mesophilic anaerobic digestion.The energy balance demonstrated that there is an economical basis of the application of the liquid hot-compressed water pretreatments in a biogas plant. However, the steam explosion and ultrasonication are energetically not profitable for corn stover pretreatment.

  18. In vitro antimicrobial activity of LED irradiation on Pseudomonas aeruginosa.

    Science.gov (United States)

    Petrini, Morena; Trentini, Paolo; Tripodi, Domenico; Spoto, Giuseppe; D'Ercole, Simonetta

    2017-03-01

    Pseudomonas aeruginosa is an opportunistic pathogen responsible of many deaths due to nosocomial pneumonia each year. It is particularly resistant to many different classes of antibiotics and disinfectants. For all these reasons, there is the necessity to find novel approaches of treatment. The aim of this study was to evaluate the effect of 880nm light emitting diodes (LED) irradiation on P. aeruginosa, in vitro. Different LED irradiation parameters (time, energy output and the addition of methylene blue and chlorhexidine) have been tested in order to evaluate the effects on this bacterium. After treatment, the colony forming units per milliliter (CFU mL-1) were recorded and the data were submitted to ANOVA and Bonferroni post hoc tests at a level of significance of 5%. A statistical significant reduction of bacterial count has been registered after 5min of LED irradiation. The antibacterial effect was directly proportional to irradiation time and the output energy. The pre-treatment with methylene blue, seems to be not effective against P. aeruginosa, independently from irradiation parameters. On the contrary, the contemporary action of LED and chlorhexidine has shown a great reduction of bacterial count that was statistical significant respect chlorhexidine and LED alone. The effect of LED irradiation was visible also after 24h, when a lower bacterial count characterized all irradiated samples respect controls. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Toxicity, sublethal effects, and potential modes of action of select fungicides on freshwater fish and invertebrates

    Science.gov (United States)

    Elskus, Adria A.

    2012-01-01

    Despite decades of agricultural and urban use of fungicides and widespread detection of these pesticides in surface waters, relatively few data are available on the effects of fungicides on fish and invertebrates in the aquatic environment. Nine fungicides are reviewed in this report: azoxystrobin, boscalid, chlorothalonil, fludioxonil, myclobutanil, fenarimol, pyraclostrobin, pyrimethanil, and zoxamide. These fungicides were identified as emerging chemicals of concern because of their high or increasing global use rates, detection frequency in surface waters, or likely persistence in the environment. A review of the literature revealed significant sublethal effects of fungicides on fish, aquatic invertebrates, and ecosystems, including zooplankton and fish reproduction, fish immune function, zooplankton community composition, metabolic enzymes, and ecosystem processes, such as leaf decomposition in streams, among other biological effects. Some of these effects can occur at fungicide concentrations well below single-species acute lethality values (48- or 96-hour concentration that effects a response in 50 percent of the organisms, that is, effective concentration killing 50 percent of the organisms in 48 or 96 hours) and chronic sublethal values (for example, 21-day no observed adverse effects concentration), indicating that single-species toxicity values may dramatically underestimate the toxic potency of some fungicides. Fungicide modes of toxic action in fungi can sometimes reflect the biochemical and (or) physiological effects of fungicides observed in vertebrates and invertebrates; however, far more studies are needed to explore the potential to predict effects in nontarget organisms based on specific fungicide modes of toxic action. Fungicides can also have additive and (or) synergistic effects when used with other fungicides and insecticides, highlighting the need to study pesticide mixtures that occur in surface waters. For fungicides that partition to

  20. A fish of many scales: extrapolating sublethal pesticide exposures to the productivity of wild salmon populations.

    Science.gov (United States)

    Baldwin, David H; Spromberg, Julann A; Collier, Tracy K; Scholz, Nathaniel L

    2009-12-01

    For more than a decade, numerous pesticides have been detected in river systems of the western United States that support anadromous species of Pacific salmon and steelhead. Over the same interval, several declining wild salmon populations have been listed as either threatened or endangered under the U.S. Endangered Species Act (ESA). Because pesticides occur in surface waters that provide critical habitat for ESA-listed stocks, they are an ongoing concern for salmon conservation and recovery throughout California and the Pacific Northwest. Because pesticide exposures are typically sublethal, a key question is whether toxicological effects at (or below) the scale of the individual animal ultimately reduce the productivity and recovery potential of wild populations. In this study we evaluate how the sublethal impacts of pesticides on physiology and behavior can reduce the somatic growth of juvenile chinook salmon (Oncorhynchus tshawytscha) and, by extension, subsequent size-dependent survival when animals migrate to the ocean and overwinter in their first year. Our analyses focused on the organophosphate and carbamate classes of insecticides. These neurotoxic chemicals have been widely detected in aquatic environments. They inhibit acetylcholinesterase, an enzyme in the salmon nervous system that regulates neurotransmitter-mediated signaling at synapses. Based on empirical data, we developed a model that explicitly links sublethal reductions in acetylcholinesterase activity to reductions in feeding behavior, food ration, growth, and size at migration. Individual size was then used to estimate size-dependent survival during migration and transition to the sea. Individual survival estimates were then integrated into a life-history population projection matrix and used to calculate population productivity and growth rate. Our results indicate that short-term (i.e., four-day) exposures that are representative of seasonal pesticide use may be sufficient to reduce the

  1. A comparison of the sublethal and lethal toxicity of four pesticides in Hyalella azteca and Chironomus dilutus.

    Science.gov (United States)

    Hasenbein, Simone; Connon, Richard E; Lawler, Sharon P; Geist, Juergen

    2015-08-01

    Laboratory toxicity testing is the primary tool used for surface water environmental risk assessment; however, there are critical information gaps regarding the sublethal effects of pesticides. In 10-day exposures, we assessed the lethal and sublethal (motility and growth) toxicities of four commonly used pesticides, bifenthrin, permethrin, cyfluthrin, and chlorpyrifos, on two freshwater invertebrates, Chironomus dilutus and Hyalella azteca. Pyrethroids were more toxic than the organophosphate chlorpyrifos in both species. Bifenthrin was most toxic to H. azteca survival and growth. Cyfluthrin was most toxic to C. dilutus. However, cyfluthrin had the greatest effect on motility on both H. azteca and C. dilutus. The evaluated concentrations of chlorpyrifos did not affect C. dilutus motility or growth, but significantly impacted H. azteca growth. Motility served as the most sensitive endpoint in assessing sublethal effects at low concentrations for both species, while growth was a good indicator of toxicity for all four pesticides for H. azteca. The integration of sublethal endpoints in ambient water monitoring and pesticide regulation efforts could improve identification of low-level pesticide concentrations that may eventually cause negative effects on food webs and community structure in aquatic environments.

  2. Evaluating sub-lethal effects of orchard-applied pyrethroids using video-tracking software to quantify honey bee behaviors.

    Science.gov (United States)

    Ingram, Erin M; Augustin, Julie; Ellis, Marion D; Siegfried, Blair D

    2015-09-01

    Managed honey bee, Apis mellifera L., colonies are contracted to pollinate fruit and nut orchards improving crop quality and yield. Colonies placed in orchards are potentially exposed to pyrethroid insecticides used for broad-spectrum pest control. Pyrethroids have been reported to pose minimal risk to bees due to their low application rates in the field and putative repellent properties. This repellency is believed to alter foraging behavior with the benefit of preventing bees from encountering a lethal dose in the field. However, sub-lethal exposure to pyrethroids may adversely impact bee behavior potentially resulting in social dysfunction or disruption of foraging. This study quantified behaviors associated with sub-lethal exposure to orchard-applied pyrethroids including, lambda-cyhalothrin, esfenvalerate, and permethrin, using video tracking software, Ethovision XT (Noldus Information Technologies). Bee locomotion, social interaction, and time spent near a food source were measured over a 24-h period. Bees treated with a pyrethroid traveled 30-71% less than control bees. Social interaction time decreased by 43% for bees treated with a high sub-lethal dose of esfenvalerate. Bees exposed to a high sub-lethal dose of permethrin spent 67% less time in social interaction and spent more than 5 times as long in the food zone compared to control bees. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Lethal and sub-lethal responses of native freshwater mussels exposed to granular Bayluscide®, a sea lamprey larvicide

    Science.gov (United States)

    Newton, Teresa; Boogaard, Michael A.; Gray, Brian R.; Hubert, Terrance D.; Schloesser, Nicholas

    2017-01-01

    The invasive sea lamprey (Petromyzon marinus) poses a substantial threat to fish communities in the Great Lakes. Efforts to control sea lamprey populations typically involve treating tributary streams with lampricides on a recurring cycle. The presence of a substantial population of larval sea lampreys in the aquatic corridor between Lakes Huron and Erie prompted managers to propose a treatment using the granular formulation of Bayluscide® that targets larval sea lampreys that reside in sediments. However, these treatments could cause adverse effects on native freshwater mussels—imperiled animals that also reside in sediments. We estimated the risk of mortality and sub-lethal effects among eight species of adult and sub-adult mussels exposed to Bayluscide® for durations up to 8 h to mimic field applications. Mortality was appreciable in some species, especially in sub-adults (range, 23–51%). The lethal and sub-lethal effects were positively associated with the duration of exposure in most species and life stage combinations. Estimates of the median time of exposure that resulted in lethal and sub-lethal effects suggest that sub-adults were often affected by Bayluscide® earlier than adults. Siphoning activity and burrowing position of mussels during exposure may have moderated the uptake of Bayluscide® and may have influenced lethal and sub-lethal responses. Given that the various species and life stages were differentially affected, it will be difficult to predict the effects of Bayluscide® treatments on mussels.

  4. Transmission electron microscopy study of Listeria monocytogenes serotype 1/2a cells exposed to sublethal heat stress and carvacrol

    Science.gov (United States)

    The objective of this study was to investigate the morphological changes that occurred in Listeria monocytogenes serotype 1/2a cells as visualized by transmission electron microscopy (TEM) after exposure to sublethal heat stress at 48°C for 60 min and in combination with lethal concentration of carv...

  5. Toxicity and sub-lethal effect of endemic plants from family Anacardiaceae on oviposition behavior of Aedes albopictus

    Directory of Open Access Journals (Sweden)

    Wan Fatma Zuharah

    2015-08-01

    Conclusions: These results clearly indicate that the acetone extract of G. renghas could be served as potential larvicide, whereas M. fasciculiflora has better sub-lethal effect for oviposition deterrence and against Ae. albopictus as an oviciding agent.

  6. Uptake and elimination of 1,2,4-trichlorobenzene in the guppy (Poecilia reticulata) at sublethal and lethal aqueous concentrations.

    NARCIS (Netherlands)

    Eck, van J.M.C.; Koelmans, A.A.; Deneer, J.W.

    1997-01-01

    The kinetics of 1,2,4-trichlorobenzene in guppies (Poecilia reticulata) have been studied in an accumulation and elimination experiment. At a sublethal exposure, uptake and elimination rate constants of 1,2,4-trichlorobenzene were determined, employing a first-order one-compartment model. The

  7. (1)H NMR-based metabolomics of Daphnia magna responses after sub-lethal exposure to triclosan, carbamazepine and ibuprofen.

    Science.gov (United States)

    Kovacevic, Vera; Simpson, André J; Simpson, Myrna J

    2016-09-01

    Pharmaceuticals and personal care products are a class of emerging contaminants that are present in wastewater effluents, surface water, and groundwater around the world. There is a need to determine rapid and reliable bioindicators of exposure and the toxic mode of action of these contaminants to aquatic organisms. (1)H nuclear magnetic resonance (NMR)-based metabolomics in combination with multivariate statistical analysis was used to determine the metabolic profile of Daphnia magna after exposure to a range of sub-lethal concentrations of triclosan (6.25-100μg/L), carbamazepine (1.75-14mg/L) and ibuprofen (1.75-14mg/L) for 48h. Sub-lethal triclosan exposure suggested a general oxidative stress condition and the branched-chain amino acids, glutamine, glutamate, and methionine emerged as potential bioindicators. The aromatic amino acids, serine, glycine and alanine are potential bioindicators for sub-lethal carbamazepine exposure that may have altered energy metabolism. The potential bioindicators for sub-lethal ibuprofen exposure are serine, methionine, lysine, arginine and leucine, which showed a concentration-dependent response. The differences in the metabolic changes were related to the dissimilar modes of toxicity of triclosan, carbamazepine and ibuprofen. (1)H NMR-based metabolomics gave an improved understanding of how these emerging contaminants impact the keystone species D. magna. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Lethal and sub-lethal effects of five pesticides used in rice farming on the earthworm Eisenia fetida

    NARCIS (Netherlands)

    Rico, Andreu; Sabater, Consuelo; Castillo, María Ángeles

    2016-01-01

    The toxicity of five pesticides typically used in rice farming (trichlorfon, dimethoate, carbendazim, tebuconazole and prochloraz) was evaluated on different lethal and sub-lethal endpoints of the earthworm Eisenia fetida. The evaluated endpoints included: avoidance behaviour after an exposure

  9. Sublethal effects of Imidacloprid on honey bee colony growth and activity at three sites in the U.S.

    Science.gov (United States)

    Field experiments in southern Arizona, central Arkansas and southern Mississippi were conducted to evaluate the effects of sublethal concentrations (0, 5, 20 and 100 ppb) of imidacloprid in sugar syrup on honey bee colony growth and activity. Response variables included discrete data from hive inspe...

  10. Innovative pretreatment strategies for biogas production.

    Science.gov (United States)

    Patinvoh, Regina J; Osadolor, Osagie A; Chandolias, Konstantinos; Sárvári Horváth, Ilona; Taherzadeh, Mohammad J

    2017-01-01

    Biogas or biomethane is traditionally produced via anaerobic digestion, or recently by thermochemical or a combination of thermochemical and biological processes via syngas (CO and H2) fermentation. However, many of the feedstocks have recalcitrant structure and are difficult to digest (e.g., lignocelluloses or keratins), or they have toxic compounds (such as fruit flavors or high ammonia content), or not digestible at all (e.g., plastics). To overcome these challenges, innovative strategies for enhanced and economically favorable biogas production were proposed in this review. The strategies considered are commonly known physical pretreatment, rapid decompression, autohydrolysis, acid- or alkali pretreatments, solvents (e.g. for lignin or cellulose) pretreatments or leaching, supercritical, oxidative or biological pretreatments, as well as combined gasification and fermentation, integrated biogas production and pretreatment, innovative biogas digester design, co-digestion, and bio-augmentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Reinitialization of evolutionary clocks during sublethal environmental stress in some invertebrates

    Science.gov (United States)

    Guex, Jean

    2006-02-01

    This paper describes the influence of high environmental stress on evolutionary trends in some selected Mesozoic ammonite lineages and some protists. During extinction periods, many ammonoids are affected by drastic simplifications of their shell geometry, ornamentation and suture line. We observe that relatively tightly coiled ammonites can give rise to highly evolute forms or uncoiled heteromorphs with simple ornamentation and almost ceratitic suture line—a phenomenon called "proteromorphosis". Such simplifications often correspond to a reappearance of ancestral geometries (primitive ornamentation, evolute coiling or uncoiling) which suggest that the evolutionary clock of these organisms can be reinitialized by extreme, sublethal, environmental stress such as giant volcanism (including its consequences on diverse pollutions and on climatic changes) and major regressive events.

  12. Feeding Inhibition: the Ups and Downs of Sublethal Effects on Grazers and Detritivores

    Science.gov (United States)

    Alexander, A.; Culp, J.; Liber, K.; Baird, D.

    2005-05-01

    Sublethal impacts are likely the primary mechanism of exposure for the aquatic community in the case of soluble agricultural pesticides. This study examines the effects of pulsed exposures of the common insecticide, imidacloprid, on the feeding and growth of the mayfly Epeorus longimanus, and the oligochaete, Lumbriculus variegatus. Examining the effects of pulsed exposures of imidacloprid is particularly relevant due to the soluble (0.51g/L) nature of this compound. Recovery experiments were conducted by exposing mayflies and oligochaetes to an environmentally realistic range (0, 0.1, 0.5, 1, 5, 10 ppb) of concentrations for a short period. Effects on feeding were measured by quantifying the foodstuffs consumed by mayflies and egested by oligochaetes. In tandem with the feeding experiments, a series of artificial stream experiments were undertaken that demonstrate the changes in growth and abundance of adult mayflies in response to this common insecticide stressor.

  13. Effects of Glyphosate-Based Herbicide Sub-Lethal Concentrations on Fish Feeding Behavior.

    Science.gov (United States)

    Giaquinto, Percilia Cardoso; de Sá, Marina Borges; Sugihara, Vanessa Seiko; Gonçalves, Bruno Bastos; Delício, Helton Carlos; Barki, Assaf

    2017-04-01

    Glyphosate-based herbicides are widely used in agricultural systems. Although the target organism are particularly plant organisms, there are numerous studies showing adverse effects in aquatic animals, such as inhibition of acetyl cholinesterase, effects on kidney, liver, and gill and stressors effects. This study analyzed the effects of commercial formulation of glyphosate on feeding behavior in Pacu (Piaractus mesopotamicus). Fish were exposed to three glyphosate concentrations (0.2, 0.6, and 1.8 ppm) for 15 days. At concentrations of 0.2 and 0.6 ppm, food intake decreased on day 13 and then returned to normal on day 15. At the highest glyphosate-based herbicide concentration, 1.8 ppm, food consumption decreased dramatically and did not recover on day 15. This study showed that glyphosate-based herbicide at sub-lethal concentrations can affect feed intake in pacu and consequently inhibits its growth.

  14. Influence of biorhythms on sensitivity of Nerita to pollutants at Sublethal levels

    Energy Technology Data Exchange (ETDEWEB)

    Battershill, C.N.; Bergquist, P.R.

    1984-01-01

    Intrinsic rhythmic activity of Nerita (Melanerita) atramentosa melanotragus was assessed under constant laboratory conditions. Activity proved to be a sensitive indicator of toxicity, and was affected by low levels of a relatively new oil dispersing agent, Shell SD LTX. How the state of activity influenced animal sensitivity to Shell SD LTX and to an oil, Maui Condensate, was investigated using short-term recovery experiments. Nerita were most sensitive during their active phase, and results during this period differed significantly from tests carried out during the inactive phase of the animal. Dispersant/oil mixture proved to be highly toxic. These findings have ecological implications and permit comment relating to the design of sublethal toxicity tests. These subjects are discussed. 37 references, 3 figures, 2 tables.

  15. Response of larval fish, Leiostomus xanthurus, to environmental stress following sublethal cadmium exposure

    Energy Technology Data Exchange (ETDEWEB)

    Middaugh, D.P.; Davis, W.R.; Yoakum, R.L.

    1975-08-01

    The toxicity of cadmium to larval fish, Leiostomus xanthurus, was studied. An incipient LC/sub 50/ concentration of approximately 0.2 to 0.3 mg/l cadmium was first estimated. Subsequent short-term sublethal tests were conducted to determine the relationship of cadmium exposure and accumulated whole body residues of the metal on the response of larvae to thermal stress and low dissolved oxygen. Results of this study indicated a significant decrease (..cap alpha.. = 0.05, t-Test) in the critical thermal maximum (CTM) for larvae exposed to 0.5 and 0.8 mg/l cadmium for 96 hours at 20/sup 0/C. Significant decreases (..cap alpha.. = 0.05, chi/sup 2/) in survival of larvae subjected to a dissolved oxygen (DO) level of 1.6 mg/l after exposure to 0.5 and 0.8 mg/l cadmium were also observed.

  16. Effects of sublethal entrainment stresses on the vulnerability of juvenile bluegill sunfish to predation

    Energy Technology Data Exchange (ETDEWEB)

    Cada, G.F.; Solomon, J.A.; Loar, J.M.

    1981-07-01

    This report provides a review of literature concerning the effects of sublethal stresses on predator-prey interactions in aquatic systems. In addition, the results of a preliminary laboratory study of the susceptibility of entrainment-stressed juvenile bluegill to striped bass predation are presented. Juvenile bluegill were exposed to thermal and physical entrainment stresses in the ORNL Power Plant Simulator and subsequently to predation by juvenile striped bass in a susceptibility to predation experimental design. None of the entrainment stresses tested (thermal shock, physical effects of pump and condenser passage, and combination of thermal and physical shock) was found to significantly increase predation rates as compared to controls, and no significant interactions between thermal and physical stresses were detected. The validity of laboratory predator-prey studies and the application of indirect mortality information for setting protective standards and predicting environmental impacts are discussed.

  17. Field-level sublethal effects of approved bee hive chemicals on Honey Bees (Apis mellifera L).

    Science.gov (United States)

    Berry, Jennifer A; Hood, W Michael; Pietravalle, Stéphane; Delaplane, Keith S

    2013-01-01

    In a study replicated across two states and two years, we tested the sublethal effects on honey bees of the miticides Apistan (tau fluvalinate) and Check Mite+ (coumaphos) and the wood preservative copper naphthenate applied at label rates in field conditions. A continuous covariate, a colony Varroa mite index, helped us disambiguate the effects of the chemicals on bees while adjusting for a presumed benefit of controlling mites. Mite levels in colonies treated with Apistan or Check Mite+ were not different from levels in non-treated controls. Experimental chemicals significantly decreased 3-day brood survivorship and increased construction of queen supercedure cells compared to non-treated controls. Bees exposed to Check Mite+ as immatures had higher legacy mortality as adults relative to non-treated controls, whereas bees exposed to Apistan had improved legacy mortality relative to non-treated controls. Relative to non-treated controls, Check Mite+ increased adult emergence weight. Although there was a treatment effect on a test of associative learning, it was not possible to statistically separate the treatment means, but bees treated with Apistan performed comparatively well. And finally, there were no detected effects of bee hive chemical on colony bee population, amount of brood, amount of honey, foraging rate, time required for marked released bees to return to their nest, percentage of released bees that return to the nest, and colony Nosema spore loads. To our knowledge, this is the first study to examine sublethal effects of bee hive chemicals applied at label rates under field conditions while disambiguating the results from mite control benefits realized from the chemicals. Given the poor performance of the miticides at reducing mites and their inconsistent effects on the host, these results defend the use of bee health management practices that minimize use of exotic hive chemicals.

  18. Stability of sublethal acid stress adaptation and induced cross protection against lauric arginate in Listeria monocytogenes.

    Science.gov (United States)

    Shen, Qian; Soni, Kamlesh A; Nannapaneni, Ramakrishna

    2015-06-16

    The stability of acid stress adaptation in Listeria monocytogenes and its induced cross protection effect against GRAS (generally recognized as safe) antimicrobial compounds has never been investigated before. In the present study, the acid stress adaptation in L. monocytogenes was initially induced in pH 5.0 tryptic soy broth supplemented with 0.6% yeast extract (TSB-YE) at 37 °C. Subsequently, the stability of acid stress adaptation, which was defined as the capacity to maintain its acquired acid adaptation after induction in the absence of sublethal acid stress, was determined at 37 °C, 22 °C or 4 °C in broth and in different food substrates. Then, the acid stress adaptation induced cross protection against lauric arginate (LAE) and its stability was investigated in TSB-YE, milk and carrot juice. Our findings show that the acid stress adaptation was stable at 4 °C up to 24h but was reversed at 37 °C or 22 °C within 2h. In the cross protection assay with LAE, the acid stress adapted cells had approximately 2 log CFU/ml greater survival than non-adapted cells in broth at 22 °C or in milk and carrot juice at 4 °C. The acid adaptation induced cross protection against LAE in L. monocytogenes was reversible within 1h at 4 °C in the absence of sublethal acid stress. Our findings suggest that the stability of acid adaptation in L. monocytogenes under cold conditions should be taken into account when the risk analysis is performed during food processing. Copyright © 2015. Published by Elsevier B.V.

  19. Mortality, Temporary Sterilization, and Maternal Effects of Sublethal Heat in Bed Bugs

    Science.gov (United States)

    Rukke, Bjørn Arne; Aak, Anders; Edgar, Kristin Skarsfjord

    2015-01-01

    Adult bed bugs were exposed to the sublethal temperatures 34.0°C, 35.5°C, 37.0°C, 38.5°C, or 40.0°C for 3, 6, or 9 days. The two uppermost temperatures induced 100% mortality within 9 and 2 days, respectively, whereas 34.0°C had no observable effect. The intermediate temperatures interacted with time to induce a limited level of mortality but had distinct effects on fecundity, reflected by decreases in the number of eggs produced and hatching success. Adult fecundity remained low for up to 40 days after heat exposure, and the time until fertility was restored correlated with the temperature-sum experienced during heat exposure. Three or 6 days of parental exposure to 38.5°C significantly lowered their offspring’s feeding and moulting ability, which consequently led to a failure to continue beyond the third instar. Eggs that were deposited at 22.0°C before being exposed to 37.0°C for 3 or 6 days died, whereas eggs that were exposed to lower temperatures were not significantly affected. Eggs that were deposited during heat treatment exhibited high levels of mortality also at 34.0°C and 35.5°C. The observed negative effects of temperatures between 34.0°C and 40.0°C may be utilized in pest management, and sublethal temperature exposure ought to be further investigated as an additional tool to decimate or potentially eradicate bed bug populations. The effect of parental heat exposure on progeny demonstrates the importance of including maternal considerations when studying bed bug environmental stress reactions. PMID:25996999

  20. Use of sublethal endpoints in sediment toxicity tests with the amphipod Hyalella azteca

    Science.gov (United States)

    Ingersoll, Chris G.; Brunson, Eric L.; Dwyer, F. James; Hardesty, Douglas K.; Kemble, Nile E.

    1998-01-01

    Short-term sediment toxicity tests that only measure effects on survival can be used to identify high levels of contamination but may not be able to identify marginally contaminated sediments. The objective of the present study was to develop a method for determining the potential sublethal effects of contaminants associated with sediment on the amphipod Hyalella azteca (e.g., reproduction). Exposures to sediment were started with 7- to 8-d-old amphipods. On day 28, amphipods were isolated from the sediment and placed in water-only chambers where reproduction was measured on day 35 and 42. Typically, amphipods were first in amplexus at about day 21 to 28 with release of the first brood between day 28 to 42. Endpoints measured included survival (day 28, 35, and 42), growth (as length and weight on day 28 and 42), and reproduction (number of young/female produced from day 28 to 42). This method was used to evaluate a formulated sediment and field-collected sediments with low to moderate concentrations of contaminants. Survival of amphipods in these sediments was typically >85% after the 28-d sediment exposures and the 14-d holding period in water to measure reproduction. Reproduction was more variable than growth; hence, more replicates might be needed to establish statistical differences among treatments. Previous studies have demonstrated that growth of H. azteca in sediment tests often provides unique information that can be used to discriminate toxic effects of exposure to contaminants. Either length or weight can be measured in sediment tests with H. azteca. However, additional statistical options are available if length is measured on individual amphipods, such as nested analysis of variance that can account for variance in length within replicates. Ongoing water-only studies testing select contaminants will provide additional data on the relative sensitivity and variability of sublethal endpoints in toxicity tests with H. azteca.

  1. Field-level sublethal effects of approved bee hive chemicals on Honey Bees (Apis mellifera L.

    Directory of Open Access Journals (Sweden)

    Jennifer A Berry

    Full Text Available In a study replicated across two states and two years, we tested the sublethal effects on honey bees of the miticides Apistan (tau fluvalinate and Check Mite+ (coumaphos and the wood preservative copper naphthenate applied at label rates in field conditions. A continuous covariate, a colony Varroa mite index, helped us disambiguate the effects of the chemicals on bees while adjusting for a presumed benefit of controlling mites. Mite levels in colonies treated with Apistan or Check Mite+ were not different from levels in non-treated controls. Experimental chemicals significantly decreased 3-day brood survivorship and increased construction of queen supercedure cells compared to non-treated controls. Bees exposed to Check Mite+ as immatures had higher legacy mortality as adults relative to non-treated controls, whereas bees exposed to Apistan had improved legacy mortality relative to non-treated controls. Relative to non-treated controls, Check Mite+ increased adult emergence weight. Although there was a treatment effect on a test of associative learning, it was not possible to statistically separate the treatment means, but bees treated with Apistan performed comparatively well. And finally, there were no detected effects of bee hive chemical on colony bee population, amount of brood, amount of honey, foraging rate, time required for marked released bees to return to their nest, percentage of released bees that return to the nest, and colony Nosema spore loads. To our knowledge, this is the first study to examine sublethal effects of bee hive chemicals applied at label rates under field conditions while disambiguating the results from mite control benefits realized from the chemicals. Given the poor performance of the miticides at reducing mites and their inconsistent effects on the host, these results defend the use of bee health management practices that minimize use of exotic hive chemicals.

  2. Using a sequential regimen to eliminate bacteria at sublethal antibiotic dosages.

    Directory of Open Access Journals (Sweden)

    Ayari Fuentes-Hernandez

    2015-04-01

    Full Text Available We need to find ways of enhancing the potency of existing antibiotics, and, with this in mind, we begin with an unusual question: how low can antibiotic dosages be and yet bacterial clearance still be observed? Seeking to optimise the simultaneous use of two antibiotics, we use the minimal dose at which clearance is observed in an in vitro experimental model of antibiotic treatment as a criterion to distinguish the best and worst treatments of a bacterium, Escherichia coli. Our aim is to compare a combination treatment consisting of two synergistic antibiotics to so-called sequential treatments in which the choice of antibiotic to administer can change with each round of treatment. Using mathematical predictions validated by the E. coli treatment model, we show that clearance of the bacterium can be achieved using sequential treatments at antibiotic dosages so low that the equivalent two-drug combination treatments are ineffective. Seeking to treat the bacterium in testing circumstances, we purposefully study an E. coli strain that has a multidrug pump encoded in its chromosome that effluxes both antibiotics. Genomic amplifications that increase the number of pumps expressed per cell can cause the failure of high-dose combination treatments, yet, as we show, sequentially treated populations can still collapse. However, dual resistance due to the pump means that the antibiotics must be carefully deployed and not all sublethal sequential treatments succeed. A screen of 136 96-h-long sequential treatments determined five of these that could clear the bacterium at sublethal dosages in all replicate populations, even though none had done so by 24 h. These successes can be attributed to a collateral sensitivity whereby cross-resistance due to the duplicated pump proves insufficient to stop a reduction in E. coli growth rate following drug exchanges, a reduction that proves large enough for appropriately chosen drug switches to clear the bacterium.

  3. Mechanisms of an increased level of serum iron in gamma-irradiated mice

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Li-hua; Zhang, Xiao-hong; Hu, Xiao-dan; Min, Xuan-yu [Nanjing University of Aeronautics and Astronautics, Department of Nuclear Science and Engineering, Nanjing (China); Zhou, Qi-fu [Nanjing University of Aeronautics and Astronautics, Department of Nuclear Science and Engineering, Nanjing (China); Nuclear and Radiation Safety Center, Beijing (China); Zhang, Hai-qian [Nanjing University of Aeronautics and Astronautics, Department of Nuclear Science and Engineering, Nanjing (China); Southeast University, Jiangsu Laboratory for Biomaterials and Devices, Nanjing (China)

    2016-03-15

    The potential mechanisms underlying the increase in serum iron concentration in gamma-irradiated mice were studied. The gamma irradiation dose used was 4 Gy, and cobalt-60 ({sup 60}Co) source was used for the irradiation. The dose rate was 0.25 Gy/min. In the serum of irradiated mice, the concentration of ferrous ions decreased, whereas the serum iron concentration increased. The concentration of ferrous ions in irradiated mice returned to normal at 21 day post-exposure. The concentration of reactive oxygen species in irradiated mice increased immediately following irradiation but returned to normal at 7 day post-exposure. Serum iron concentration in gamma-irradiated mice that were pretreated with reduced glutathione was significant lower (p < 0.01) than that in mice exposed to gamma radiation only. However, the serum iron concentration was still higher than that in normal mice (p < 0.01). This change was biphasic, characterized by a maximal decrease phase occurring immediately after gamma irradiation (relative to the irradiated mice) and a recovery plateau observed during the 7th and 21st day post-irradiation, but serum iron recovery was still less than that in the gamma-irradiated mice (4 Gy). In gamma-irradiated mice, ceruloplasmin activity increased and serum copper concentration decreased immediately after irradiation, and both of them were constant during the 7th and 21st day post-irradiation. It was concluded that ferrous ions in irradiated mice were oxidized to ferric ions by ionizing radiation. Free radicals induced by gamma radiation and ceruloplasmin mutually participated in this oxidation process. The ferroxidase effect of ceruloplasmin was achieved by transfer of electrons from ferrous ions to cupric ions. (orig.)

  4. Intra- and intergenerational persistence of an insect nucleopolyhedrovirus: adverse effects of sublethal disease on host development, reproduction, and susceptibility to superinfection.

    Science.gov (United States)

    Cabodevilla, Oihana; Villar, Eduardo; Virto, Cristina; Murillo, Rosa; Williams, Trevor; Caballero, Primitivo

    2011-05-01

    Sublethal infections by Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) are common in field populations of the beet armyworm (S. exigua, Hübner) in the Almerian horticultural region of Spain. Inoculation of second, third, and fourth instars with occlusion bodies (OBs) of an isolate (VT-SeAl1) associated with vertically transmitted infections resulted in 15 to 100% of sublethal infection in adult survivors, as determined by reverse transcription-PCR (RT-PCR) detection of viral DNA polymerase transcripts, and quantitative PCR (qPCR) targeted at the DNA polymerase gene. The prevalence of adult sublethal infection was positively related to the inoculum OB concentration consumed during the larval stage. Sublethal infections persisted in OB-treated insects for at least five generations. Viral transcripts were more frequently detected in adult insects than in third instars. qPCR analysis indicated a consistently higher prevalence of sublethal infection than RT-PCR. Sublethal infection was associated with significant reductions in pupal weight, adult emergence, fecundity, and fertility (egg hatch) and significant increases in larval development time and duration of the preoviposition period. Insects taken from a persistently infected experimental population were significantly more susceptible to the OB inoculum than control insects that originated from the same virus-free colony as the persistently infected insects. We conclude that OB treatment results in rapid establishment of sublethal infections that persist between generations and which incur costs in the development and reproductive capacity of the host insect.

  5. Induction and stability of oxidative stress adaptation in Listeria monocytogenes EGD (Bug600) and F1057 in sublethal concentrations of H2O2 and NaOH.

    Science.gov (United States)

    De Abrew Abeysundara, Piumi; Nannapaneni, Ramakrishna; Soni, Kamlesh A; Sharma, Chander S; Mahmoud, Barakat

    2016-12-05

    Food processing and food handling environments may contain residual levels of sanitizers or cleaners which may trigger oxidative stress adaptation in Listeria monocytogenes. The aim of this study was to determine the induction and stability of oxidative stress adaptation in L. monocytogenes EGD (Bug600) (serotype 1/2a) and F1057 (serotype 4b) at different concentrations and times of sublethal oxidative stress induced by H2O2 or sublethal alkali stress induced by NaOH at 37°C. Both L. monocytogenes Bug600 and F1057 strains showed significantly higher survival in lethal oxidative stress (1000ppm H2O2) after pre-exposure to 50ppm H2O2 for 30min compared to control cells (no pre-exposure to H2O2). When the cells were pre-exposed to sublethal alkali stress by NaOH, the oxidative stress adaptation was induced within 5min in L. monocytogenes. The survival of both L. monocytogenes strains was increased by 2 to 4.5 logs in lethal oxidative stress when the cells were pre-exposed to sublethal alkali stress at pH9 from 5 to 120min by NaOH compared to control cells (no pre-exposure to sublethal alkali pH). Two other alkali reagents tested (KOH and NH4OH) also induced oxidative stress adaptation in L. monocytogenes. For both L. monocytogenes strains, the oxidative stress adaptation induced by sublethal H2O2 was reversible in 30min and that induced by sublethal alkali stress was reversible within 60min at 37°C in the absence of such sublethal stress. These findings show that sublethal oxidative or alkali stress conditions can induce oxidative stress adaptation that may increase the risk of survival of L. monocytogenes cells in lethal oxidative stress. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. [Comparison of different G-CSF treatment effectiveness in experiments on irradiated mice].

    Science.gov (United States)

    Rozhdestvenskiĭ, L M; Shchegoleva, R A; Deshevoĭ, Iu B; Lisina, N I; Titov, B A

    2012-01-01

    In the experiments on F1 (CBA x C57BL) and BALB mice irradiated by 137Cs gamma-rays, preparations of unglycosilated G-SCF such as Neupogen and their domestic analogs Leucostim and Neupomax were investigated. The tests such as 9-day bone marrow cellularity (BMC) and endogenous CFUs, the neutrophile number restoration, the 30-day survival index have shown that all three preparations have an approximately equal effectiveness relating to acute radiation disease treatment and granulopoiesis stimulation after a 5-10 day consecutive administration following irradiation of mice at lethal and sublethal doses. We have come to the conclusion that Leucostim and Neupomax can be regarded as adequate substitutes for Neupogen.

  7. Influence of He-Ne laser irradiation of soybean seeds on seed mycoflora, growth, nodulation, and resistance to Fusarium solani.

    Science.gov (United States)

    Ouf, S A; abdel-Hady, N F

    1999-01-01

    Laser irradiation of soybean seeds for 3 min caused a clear reduction in the number of seed-borne fungi which became more pronounced as the irradiation time was extended. Pretreatment of the seeds with methylene blue, methyl red and carmine enhanced the effect of laser. Rhizoctonia solani, Alternaria tenuissima, Cercospora kikuchii and Colletotrichum truncatum were completely eliminated when the seeds were pretreated with a dye and irradiated for 10 min. Seed germination was stimulated on exposure of the seed to 1-min irradiation. At such dose, most of the dyes were accelerators while the higher doses were inhibitory to seed germination. Chlorophyll a, chlorophyll b and carotenoid content of developed plants differed, depending on the irradiation dose and dye treatment of the seeds. In seeds irradiated for 1 or 3 min, chlorophyll a formation was less affected than chlorophyll b formation. In seeds irradiated for 10 min, both the chlorophyll contents were decreased especially in the presence of some applied dyes. On the other hand, there was an increase in carotenoid content of soybean leaves when the laser dose increased. The number and dry mass of nodules were mostly greater (as compared to the corresponding control), when the seeds irradiated for 1 or 3 min were pretreated with methyl red, chlorophenol red, crystal violet and methylene blue. Irradiation of pre-sowing seeds greatly protected soybean stands against F. solani. The disease incidence differed somewhat when the irradiated seeds were pretreated with dyes. The reduction in disease incidence was accompanied by accumulation of high proline and phenol levels in the infected root tissues of soybean, suggesting that these compounds have a certain role in the prevention of disease development.

  8. Modelling property changes in graphite irradiated at changing irradiation temperature

    CSIR Research Space (South Africa)

    Kok, S

    2011-01-01

    Full Text Available A new method is proposed to predict the irradiation induced property changes in nuclear; graphite, including the effect of a change in irradiation temperature. The currently used method; to account for changes in irradiation temperature, the scaled...

  9. Structural Analysis of Alkaline Pretreated Rice Straw for Ethanol Production

    National Research Council Canada - National Science Library

    Paripok Phitsuwan; Chutidet Permsriburasuk; Sirilak Baramee; Thitiporn Teeravivattanakit; Khanok Ratanakhanokchai

    2017-01-01

    ...) at two pretreatment temperatures: room temperature and 60°C. Statistical analysis indicated similarity of enzymatic glucose production at both pretreatment temperatures after 3-day incubation...

  10. Integrated analysis of hydrothermal flow through pretreatment

    Directory of Open Access Journals (Sweden)

    Archambault-Leger Veronique

    2012-07-01

    Full Text Available Abstract Background The impact of hydrothermal flowthrough (FT pretreatment severity on pretreatment and solubilization performance metrics was evaluated for three milled feedstocks (corn stover, bagasse, and poplar and two conversion systems (simultaneous saccharification and fermentation using yeast and fungal cellulase, and fermentation by Clostridium thermocellum. Results Compared to batch pretreatment, FT pretreatment consistently resulted in higher XMG recovery, higher removal of non-carbohydrate carbon and higher glucan solubilization by simultaneous saccharification and fermentation (SSF. XMG recovery was above 90% for FT pretreatment below 4.1 severity but decreased at higher severities, particularly for bagasse. Removal of non-carbohydrate carbon during FT pretreatment increased from 65% at low severity to 80% at high severity for corn stover, and from 40% to 70% for bagasse and poplar. Solids obtained by FT pretreatment were amenable to high conversion for all of the feedstocks and conversion systems examined. The optimal time and temperature for FT pretreatment on poplar were found to be 16 min and 210°C. At these conditions, SSF glucan conversion was about 85%, 94% of the XMG was removed, and 62% of the non carbohydrate mass was solubilized. Solubilization of FT-pretreated poplar was compared for C. thermocellum fermentation (10% inoculum, and for yeast-fungal cellulase SSF (5% inoculum, cellulase loading of 5 and 10 FPU/g glucan supplemented with β-glucosidase at 15 and 30 U/g glucan. Under the conditions tested, which featured low solids concentration, C. thermocellum fermentation achieved faster rates and more complete conversion of FT-pretreated poplar than did SSF. Compared to SSF, solubilization by C. thermocellum was 30% higher after 4 days, and was over twice as fast on ball-milled FT-pretreated poplar. Conclusions XMG removal trends were similar between feedstocks whereas glucan conversion trends were significantly

  11. Anaerobic digestion of organic fraction of municipal solid waste combining two pretreatment modalities, high temperature microwave and hydrogen peroxide.

    Science.gov (United States)

    Shahriari, Haleh; Warith, Mostafa; Hamoda, Mohamed; Kennedy, Kevin J

    2012-01-01

    In order to enhance anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW), pretreatment combining two modalities, microwave (MW) heating in presence or absence of hydrogen peroxide (H(2)O(2)) were investigated. The main pretreatment variables affecting the characteristics of the OFMSW were temperature (T) via MW irradiation and supplemental water additions of 20% and 30% (SWA20 and SW30). Subsequently, the focus of this study was to evaluate mesophilic batch AD performance in terms of biogas production, as well as changes in the characteristics of the OFMSW post digestion. A high MW induced temperature range (115-175°C) was applied, using sealed vessels and a bench scale MW unit equipped with temperature and pressure controls. Biochemical methane potential (BMP) tests were conducted on the whole OFMSW as well as the liquid fractions. The whole OFMSW pretreated at 115°C and 145°C showed 4-7% improvement in biogas production over untreated OFMSW (control). When pretreated at 175°C, biogas production decreased due to formation of refractory compounds, inhibiting the digestion. For the liquid fraction of OFMSW, the effect of pretreatment on the cumulative biogas production (CBP) was more pronounced for SWA20 at 145°C, with a 26% increase in biogas production after 8days of digestion, compared to the control. When considering the increased substrate availability in the liquid fraction after MW pretreatment, a 78% improvement in biogas production vs. the control was achieved. Combining MW and H(2)O(2) modalities did not have a positive impact on OFMSW stabilization and enhanced biogas production. In general, all samples pretreated with H(2)O(2) displayed a long lag phase and the CBP was usually lower than MW irradiated only samples. First order rate constant was calculated. Copyright © 2011 Elsevier Ltd. All rights reserved.

  12. Irradiation Creep in Graphite

    Energy Technology Data Exchange (ETDEWEB)

    Ubic, Rick; Butt, Darryl; Windes, William

    2014-03-13

    An understanding of the underlying mechanisms of irradiation creep in graphite material is required to correctly interpret experimental data, explain micromechanical modeling results, and predict whole-core behavior. This project will focus on experimental microscopic data to demonstrate the mechanism of irradiation creep. High-resolution transmission electron microscopy should be able to image both the dislocations in graphite and the irradiation-induced interstitial clusters that pin those dislocations. The team will first prepare and characterize nanoscale samples of virgin nuclear graphite in a transmission electron microscope. Additional samples will be irradiated to varying degrees at the Advanced Test Reactor (ATR) facility and similarly characterized. Researchers will record microstructures and crystal defects and suggest a mechanism for irradiation creep based on the results. In addition, the purchase of a tensile holder for a transmission electron microscope will allow, for the first time, in situ observation of creep behavior on the microstructure and crystallographic defects.

  13. Cold storage enhances the efficacy and margin of security in postharvest irradiation treatments against fruit flies (Diptera: Tephritidae).

    Science.gov (United States)

    Follett, Peter A; Snook, Kirsten

    2013-10-01

    Cold storage is used to preserve fruit quality after harvest during transportation in marketing channels. Low temperature can be a stressor for insects that reduces survivorship, and cold storage may contribute to the efficacy of postharvest quarantine treatments such as irradiation against quarantine insect pests. The combined effect of irradiation and cold storage was examined in a radiation-tolerant fruit fly, Bactrocera cucurbitae Coquillet (melon fly), and a radiation-intolerant fruit fly, Ceratitis capitata (Wiedemann) (Mediterranean fruit fly) (Diptera: Tephritidae). Third instars on diet or in papaya were treated with a sublethal radiation dose of 30 Gy and stored at 4 or 11 degrees C for 3-13 d and held for adult emergence. For both fruit fly species, survival of third instars to the adult stage generally decreased with increasing cold storage duration at 4 or 11 degrees C in diet or papaya. Survivorship differences were highly significant for the effects of substrate (diet > papaya), temperature (11 > 4 degrees C),and irradiation (0 > 30 Gy). Few Mediterranean fruit flies survived in any cold storage treatment after receiving a radiation dose of 30 Gy. No melon fly larvae survived to the adult stage after irradiation and 11 d cold storage at 4 or 11 degrees C in papayas. Cold storage enhances the efficacy and widens the margin of security in postharvest irradiation treatments. Potentially irradiation and cold storage can be used in combination to reduce the irradiation exposure requirements of quarantine treatments.

  14. Stimulation of Hepatoma Cell Invasiveness and Metastatic Potential by Proteins Secreted From Irradiated Nonparenchymal Cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Leyuan [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Wang Zhiming [Department of Medical Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Gao Yabo [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Wang Lingyan [Experimental Research Center, Zhongshan Hospital, Fudan University, Shanghai (China); Zeng Zhaochong, E-mail: zeng.zhaochong@zs-hospital.sh.cn [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China)

    2012-11-01

    Purpose: To determine whether factors secreted by irradiated liver nonparenchymal cells (NPCs) may influence invasiveness and/or metastatic potential of hepatocellular carcinoma (HCC) cells and to elucidate a possible mechanism for such effect. Methods and Materials: Primary rat NPCs were cultured and divided into irradiated (10-Gy X-ray) and nonirradiated groups. Forty-eight hours after irradiation, conditioned medium from irradiated (SR) or nonirradiated (SnonR) cultures were collected and added to sublethally irradiated cultures of the hepatoma McA-RH7777 cell line. Then, hepatoma cells were continuously passaged for eight generations (RH10Gy-SR and RH10Gy-SnonR). The invasiveness and metastatic potential of McA-RH7777, RH10Gy-SnonR, and RH10Gy-SR cells were evaluated using an in vitro gelatinous protein (Matrigel) invasion and an in vivo metastasis assay. In addition, SR and SnonR were tested using rat cytokine antibody arrays and enzyme-linked immunosorbent assay (ELISA). Results: In vitro gelatinous protein invasion assay indicated that the numbers of invading cells was significantly higher in RH10Gy-SR (40 {+-} 4.74) than in RH10Gy-SnonR (30.6 {+-} 3.85) cells, and lowest in McA-RH7777 (11.4 {+-} 3.56) cells. The same pattern was observed in vivo in a lung metastasis assay, as evaluated by number of metastatic lung nodules seen with RH10Gy-SR (28.83 {+-} 5.38), RH10Gy-SnonR (22.17 {+-} 4.26), and McA-RH7777 (8.3 {+-} 3.8) cells. Rat cytokine antibody arrays and ELISA demonstrated that metastasis-promoting cytokines (tumor necrosis factor-{alpha} and interleukin-6), circulating growth factors (vascular endothelial growth factor and epidermal growth factor), and metalloproteinases (MMP-2 and MMP-9) were upregulated in SR compared with SnonR. Conclusions: Radiation can increase invasiveness and metastatic potential of sublethally irradiated hepatoma cells, and soluble mediators released from irradiated NPCs promote this potential. Increased secretion of

  15. Gastroprotective effect of kefir on ulcer induced in irradiated rats.

    Science.gov (United States)

    Fahmy, Hanan A; Ismail, Amel F M

    2015-03-01

    The current study was designed to investigate the protective effect of kefir milk on ethanol-induced gastric ulcers in γ-irradiated rats. The results of the present study revealed that treatment with γ-irradiation and/or ethanol showed a significant increase in ulcers number, total acidity, peptic, H(+)K(+)ATPase, MMP-2 and MMP-9 activities and MDA level, which were accompanied by a significant decrease in the mucus content, the stomach GSH level, the GSH-Px activity and DNA damage. Pre-treatment with kefir milk exert significant improvement in all the tested parameters. Kefir milk exerts comparable effect to that of the antiulcer drug ranitidine. In conclusion, the present study revealed that oral administration of kefir milk prevents ethanol-induced gastric ulcer in γ-irradiated rats that could attribute to its antioxidant, anti-apoptotic and radio-protective activities. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Evaluation of Ion Irradiation Behavior of ODS Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jin Sung; Kim, Min Chul; Hong, Jun Hwa; Han, Chang Hee; Chang, Young Mun; Bae, Chang Soo; Bae, Yoon Young; Chang, Moon Hee

    2006-08-15

    FM steel (Grade 92) and ODS alloy(MA956) specimens were ion irradiated with 122 MeV Ne ions. Irradiation temperatures were about 450 and 550 .deg. C and the peak dose was 1, 5, and 10 dpa. Cross-sectional TEM samples were prepared by the electrolytic Ni-plating after pre-treatment of the irradiated specimens. Irradiation cavities in FM steel and ODS alloy specimens were not much different in size; about 20 nm in diameter in both specimens irradiated at around 450 .deg. C. However, the size distribution of cavities in FM steel specimens was broader than that in ODS alloy specimen, indicating that the cavity growth probably via coalescence). It was noticeable that the location and the preferential growth of the cavities in FM steel specimens: cavities on the PAGB (prior austenite grain boundary) was significantly larger than those within the grains. This could be an important issue for the mechanical properties, especially high temperature creep, fracture toughness, and so on. The dependency of the dose threshold and swelling on the ratio of the inert gas concentration/dpa was analysed for the various irradiation source, including He, Ne, Fe/He, and fast neutron, and the empirical correlation was established.

  17. Development and Establishment of Detection Method of Irradiated Foods

    Energy Technology Data Exchange (ETDEWEB)

    Byun, Myung Woo; Lee, Ju Woon; Kim, Dong Ho; Jo, Cheo Run; Kim, Jang Ho; Kim, Kyong Su

    2004-12-15

    The present project was related to the development and establishment of the detection techniques for the safety management of gamma-irradiated food and particularly conducted for the establishment of standard detection method for gamma-irradiated dried spices and raw materials, dried meat and fish powder for processed foods, bean paste powder, red pepper paste powder, soy sauce powder, and starch for flavoring ingredients described in 3, 6, 7 section of Korean Food Standard. Since the approvement of gamma-irradiated food items will be enlarged due to the international tendency for gamma-irradiated food, it was concluded that the establishment of detailed detection methods for each food group is not efficient for the enactment and enforcement of related regulations. For this reason, in order to establish the standard detection method, a detection system for gamma-irradiated food suitable for domestic operation was studied using comparative analysis of domestic and foreign research data classified by items and methods and European Standard as a reference. According to the comparative analyses of domestic and foreign research data and regulations of detection for gamma-irradiated food, it was concluded to be desirable that the optimal detection method should be decided after principal detection tests such as physical, chemical, and biological detection methods are established as standard methods and that the specific descriptions such as pre-treatment of raw materials, test methods, and the evaluation of results should be separately prescribed.

  18. Development of a New Technique to Assess Susceptibility to Predation Resulting from Sublethal Stresses (Indirect Mortality)

    Energy Technology Data Exchange (ETDEWEB)

    Cada, G.F.

    2003-08-25

    Fish that pass through a hydroelectric turbine may not be killed directly, but may nonetheless experience sublethal stresses that will increase their susceptibility to predators (indirect mortality). There is a need to develop reliable tests for indirect mortality so that the full consequences of passage through turbines (and other routes around a hydroelectric dam) can be assessed. We evaluated a new technique for assessing indirect mortality, based on a behavioral response to a startling stimulus (akin to perceiving an approaching predator). We compare this technique to the standard predator preference test. The behavioral response is a rapid movement commonly referred to as a startle response, escape response, or C-shape, based on the characteristic body position assumed by the fish. When viewed from above, a startled fish bends into a C-shape, then springs back and swims away in a direction different from its original orientation. This predator avoidance (escape) behavior can be compromised by sublethal stresses that temporarily stun or disorient the fish. We subjected striped shiners and fathead minnows to varying intensities of either turbulence (10-, 20- or 30-min) or 2-min exposures to a fish anesthetic (100 or 200 mg/L of tricaine methanesulfonate), and evaluated their subsequent behavior. Individual fish were given a startle stimulus and filmed with a high-speed video camera. Each fish was startled and filmed twice before being stressed, and then at 1-, 5-, 15-, and 30-min post-exposure. The resulting image files were analyzed for a variety of behavioral measures including: presence of a response, time to first reaction, duration of reaction, time to formation of maximum C-shape, time to completion of C-shape, and completeness of C-shape. The most immediate measure of potential changes in fish behavior was whether stressed fish exhibited a startle response. For striped shiners, the number of fish not responding to the stimulus was significantly different

  19. Hydrolysis of alkaline pretreated banana peel

    Science.gov (United States)

    Fatmawati, A.; Gunawan, K. Y.; Hadiwijaya, F. A.

    2017-11-01

    Banana peel is one of food wastes that are rich in carbohydrate. This shows its potential as fermentation substrate including bio-ethanol. This paper presented banana peel alkaline pretreatment and enzymatic hydrolysis. The pretreatment was intended to prepare banana peel in order to increase hydrolysis performance. The alkaline pretreatment used 10, 20, and 30% w/v NaOH solution and was done at 60, 70 and 80°C for 1 hour. The hydrolysis reaction was conducted using two commercial cellulose enzymes. The reaction time was varied for 3, 5, and 7 days. The best condition for pretreatment process was one conducted using 30% NaOH solution and at 80°C. This condition resulted in cellulose content of 90.27% and acid insoluble lignin content of 2.88%. Seven-day hydrolysis time had exhibited the highest reducing sugar concentration, which was7.2869 g/L.

  20. Understanding Ionic Liquid Pretreatment of Lignocellulosic Biomasses

    Science.gov (United States)

    Pretreatment of biomass is essential for breaking apart highly ordered and crystalline plant cell walls and loosening the lignin and hemicellulose conjugation to cellulose microfibrills, thereby facilitating enzyme accessibility and adsorption and reducing costs of downstream saccharification proces...

  1. Extrusion Pretreatment of Lignocellulosic Biomass: A Review

    Directory of Open Access Journals (Sweden)

    Jun Zheng

    2014-10-01

    Full Text Available Bioconversion of lignocellulosic biomass to bioethanol has shown environmental, economic and energetic advantages in comparison to bioethanol produced from sugar or starch. However, the pretreatment process for increasing the enzymatic accessibility and improving the digestibility of cellulose is hindered by many physical-chemical, structural and compositional factors, which make these materials difficult to be used as feedstocks for ethanol production. A wide range of pretreatment methods has been developed to alter or remove structural and compositional impediments to (enzymatic hydrolysis over the last few decades; however, only a few of them can be used at commercial scale due to economic feasibility. This paper will give an overview of extrusion pretreatment for bioethanol production with a special focus on twin-screw extruders. An economic assessment of this pretreatment is also discussed to determine its feasibility for future industrial cellulosic ethanol plant designs.

  2. Industrial Pretreatment Program for New England

    Science.gov (United States)

    The Industrial Pretreatment Program prevents the discharge of pollutants to Publicly-Owned Treatment Works (POTWs) which will interfere with the operations of the POTW or its use and disposal of municipal biosolids.

  3. Effects of Surfactants and Microwave-assisted Pretreatment of Orange Peel on Extracellular Enzymes Production by Aspergillus japonicus PJ01.

    Science.gov (United States)

    Li, Pei-jun; Xia, Jin-lan; Shan, Yang; Nie, Zhen-yuan; Wang, Fei-ran

    2015-06-01

    The effects of surfactants and microwave pretreatment of orange peel powder (OPP) on the production of pectinase, cellulase, and xylanase by Aspergillus japonicus PJ01 in submerged fermentation were investigated. The results showed that when OPP was pretreated only by microwave (630 W, 9 min, and liquid/solid ratio 5), the activities of exo-pectinase, carboxymethyl cellulase (CMCase), xylanase, and filter paper cellulase (FPase) were increased by 11.8, 20.6, 16.2, and 24.0 %, respectively, and when OPP was pretreated by microwave at the same conditions cited above plus PEG 4000 at the concentration of 3 g/L, the activities of the above four enzymes were enhanced by 40.2, 30.3, 40.4, and 40.0 % after 84-h cultivation, respectively. It is suggested a synergistic effect between microwave and surfactant treatment in enhancing the multiextracellular enzymes production by OPP fermentation of A. japonicus PJ01. Chemical composition and Fourier transform infrared spectroscopy (FTIR) analysis displayed that the microwave pretreatment of OPP led to the decrease of hemicellulose and essential oil contents. Scanning electron microscope (SEM) showed that OPP surface after microwave pretreatment became porous and more susceptible to be invaded by A. japonicus. The results demonstrated that pretreatment of OPP by surfactant PEG 4000 and microwave irradiation as environment-friendly way was cost-effective in enhancing the multienzyme production from agricultural waste orange peel.

  4. Pretreatment techniques for biofuels and biorefineries

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhen (ed.) [Chinese Academy of Sciences, Kunming, YN (China). Xishuangbanna Tropical Botonical Garden

    2013-02-01

    The first book focused on pretreatment techniques for biofuels contributed by the world's leading experts. Extensively covers the different types of biomass, various pretreatment approaches and methods that show the subsequent production of biofuels and chemicals. In addition to traditional pretreatment methods, novel techniques are also introduced and discussed. An accessible reference work for students, researchers, academicians and industrialists in biorefineries. This book includes 19 chapters contributed by the world's leading experts on pretreatment methods for biomass. It extensively covers the different types of biomass (e.g. molasses, sugar beet pulp, cheese whey, sugarcane residues, palm waste, vegetable oil, straws, stalks and wood), various pretreatment approaches (e.g. physical, thermal, chemical, physicochemical and biological) and methods that show the subsequent production of biofuels and chemicals such as sugars, ethanol, extracellular polysaccharides, biodiesel, gas and oil. In addition to traditional methods such as steam, hot-water, hydrothermal, diluted-acid, organosolv, ozonolysis, sulfite, milling, fungal and bacterial, microwave, ultrasonic, plasma, torrefaction, pelletization, gasification (including biogas) and liquefaction pretreatments, it also introduces and discusses novel techniques such as nano and solid catalysts, organic electrolyte solutions and ionic liquids. This book offers a review of state-of-the-art research and provides guidance for the future paths of developing pretreatment techniques of biomass for biofuels, especially in the fields of biotechnology, microbiology, chemistry, materials science and engineering. It intends to provide a systematic introduction of pretreatment techniques. It is an accessible reference work for students, researchers, academicians and industrialists in biorefineries.

  5. Effect of particle irradiation on cell cycle progression

    Energy Technology Data Exchange (ETDEWEB)

    Eguchi, Kiyomi [National Inst. of Radiological Sciences, Chiba (Japan); Ohara, Hiroshi

    1997-02-01

    We studied effects of fractionated exposure of heavy ion beams with high linear energy transfer (LET). Asynchronous V79 cells were irradiated by He-3 or C ion beam at cyclotron at NIRS (12 MeV/u, LET{approx_equal} 20-250 keV/{mu}m). Extent of recovery of sublethal damage (SLDR) decreased with increasing LET. At the highest LET tested, the enhancement of cell killing (potentiation) was observed. Flow cytometry data showed the more efficient accumulation of cells at a G2/M phase at 4 h after irradiation by high LET particle beams than by X-rays. This potentiation might be caused by partial synchronization at a cell cycle position (s) where cells are sensitive to heavy ion exposure. When carbon ion beam with spread-out Bragg peak (SBP) at the RIKEN Ring Cyclotron (initial energy=135 MeV/u) were split into 2 equal exposure at 12-hr-interval, SLDR was observed at the entrance of the beam. In contrast, little recovery was observed at middle or distal peak positions. These results showed the benefits of carbon ion beam for cancer therapy, because we can expect some recovery in normal tissue at entrance of the beam, whereas no recovery in tumor at SBP. (author)

  6. Lignocellulosic biomass-Thermal pretreatment with steam: Pretreatment techniques for biofuels and biorefineries

    DEFF Research Database (Denmark)

    Toor, Saqib; Rosendahl, Lasse; Hoffmann, Jessica

    2013-01-01

    With the ever rising demand for more energy and the limited availability of depleted world resources, many are beginning to look for alternatives to fossil fuels. Liquid biofuel, in particular, is of key interest to decrease our dependency on fuels produced from imported petroleum. Biomass pre...... of different pretreatment methods are known to enhance the digestibility of lingo-cellulosic biomass by affecting these limiting factors. Some of them are: milling, thermal pretreatment with steam or hot water, acid pre-treatment and alkaline pre-treatment. This chapter will focus on one of the more promising...

  7. Sublethal pesticide doses negatively affect survival and the cellular responses in American foulbrood-infected honeybee larvae

    Science.gov (United States)

    López, Javier Hernández; Krainer, Sophie; Engert, Antonia; Schuehly, Wolfgang; Riessberger-Gallé, Ulrike; Crailsheim, Karl

    2017-02-01

    Disclosing interactions between pesticides and bee infections is of most interest to understand challenges that pollinators are facing and to which extent bee health is compromised. Here, we address the individual and combined effect that three different pesticides (dimethoate, clothianidin and fluvalinate) and an American foulbrood (AFB) infection have on mortality and the cellular immune response of honeybee larvae. We demonstrate for the first time a synergistic interaction when larvae are exposed to sublethal doses of dimethoate or clothianidin in combination with Paenibacillus larvae, the causative agent of AFB. A significantly higher mortality than the expected sum of the effects of each individual stressor was observed in co-exposed larvae, which was in parallel with a drastic reduction of the total and differential hemocyte counts. Our results underline that characterizing the cellular response of larvae to individual and combined stressors allows unmasking previously undetected sublethal effects of pesticides in colony health.

  8. Evaluation of Pyrethrin Formulations on Dengue/Dengue Haemorrhagic Fever Vectors in the Laboratory and Sublethal Effects

    Directory of Open Access Journals (Sweden)

    S Sulaiman

    2007-12-01

    Full Text Available In Southeast Asia, Aedes aegypti (L. has been incriminated as principal vector of dengue viruses and Ae. albopictus as the secondary vector of dengue fever. Therefore, the aim of this study was to investigate the effectiveness of three for-mula¬tions of pyrethrin derived from Tanacetum cinerariaefolium against the dengue/dengue haemorrhagic fever vectors Aedes aegypti and Ae. albopictus in the laboratory. The testings employed 2 methodologies: the WHO Larval Bioassay and WHO Adult Bioassay. The results showed that all the three pyrethrin formulations had larvicidal and adulticidal activi-ties. The impact of the sublethal doses of pyrethrin formulations on Aedes spp. larvae resulted in 4-6% of alive adult emergence compared to 90% of Ae. aegypti emerging adults and 96% Ae. albopictus alive adult emergence in the control. The impact of sublethal doses of the pyrethrin formulations caused very low fecundity on both Aedes spp. compared to the control (P< 0.05.

  9. Physicochemical Evidence on Sublethal Neonicotinoid Imidacloprid Interacting with an Odorant-Binding Protein from the Tea Geometrid Moth, Ectropis obliqua.

    Science.gov (United States)

    Li, Hongliang; Zhao, Lei; Fu, Xiaobin; Song, Xinmi; Wu, Fan; Tang, Mingzhu; Cui, Hongchun; Yu, Jizhong

    2017-04-26

    Nowadays the excessive usage of neonicotinoid insecticides always results in residues in Chinese tea fields. It is not clear whether the insecticide residue at the sublethal level influences the physiological processes of tea pests. Here, we provide evidence of interaction between the neonicotinoid imidacloprid and a general odorant-binding protein, EoblGOBP2, from the tea geometrid moth, Ectropis obliqua. The interacting process was demonstrated through multiple fluorescence spectra, UV absorption spectra, circular dichroism (CD) spectra, molecular docking, etc. The binding mode was determined to be static (from 300 to 310 K) and dynamic quenching (from 290 to 300 K). The binding distance was calculated to be 6.9 nm on the basis of FRET theory. According to the thermodynamic analysis, the process was mainly driven by enthalpy (ΔH neonicotinoid insecticide at sublethal level may still affect the olfactory cognition of the tea geometrid moth to volatile compounds from tea leaves.

  10. Effects of Sublethal Fungicides on Mutation Rates and Genomic Variation in Fungal Plant Pathogen, Sclerotinia sclerotiorum.

    Science.gov (United States)

    Amaradasa, B Sajeewa; Everhart, Sydney E

    2016-01-01

    Pathogen exposure to sublethal doses of fungicides may result in mutations that may represent an important and largely overlooked mechanism of introducing new genetic variation into strictly clonal populations, including acquisition of fungicide resistance. We tested this hypothesis using the clonal plant pathogen, Sclerotinia sclerotiorum. Nine susceptible isolates were exposed independently to five commercial fungicides with different modes of action: boscalid (respiration inhibitor), iprodione (unclear mode of action), thiophanate methyl (inhibition of microtubulin synthesis) and azoxystrobin and pyraclostrobin (quinone outside inhibitors). Mycelium of each isolate was inoculated onto a fungicide gradient and sub-cultured from the 50-100% inhibition zone for 12 generations and experiment repeated. Mutational changes were assessed for all isolates at six neutral microsatellite (SSR) loci and for a subset of isolates using amplified fragment length polymorphisms (AFLPs). SSR analysis showed 12 of 85 fungicide-exposed isolates had a total of 127 stepwise mutations with 42 insertions and 85 deletions. Most stepwise deletions were in iprodione- and azoxystrobin-exposed isolates (n = 40/85 each). Estimated mutation rates were 1.7 to 60-fold higher for mutated loci compared to that expected under neutral conditions. AFLP genotyping of 33 isolates (16 non-exposed control and 17 fungicide exposed) generated 602 polymorphic alleles. Cluster analysis with principal coordinate analysis (PCoA) and discriminant analysis of principal components (DAPC) identified fungicide-exposed isolates as a distinct group from non-exposed control isolates (PhiPT = 0.15, P = 0.001). Dendrograms based on neighbor-joining also supported allelic variation associated with fungicide-exposure. Fungicide sensitivity of isolates measured throughout both experiments did not show consistent trends. For example, eight isolates exposed to boscalid had higher EC50 values at the end of the experiment, and

  11. Effects of Sublethal Fungicides on Mutation Rates and Genomic Variation in Fungal Plant Pathogen, Sclerotinia sclerotiorum.

    Directory of Open Access Journals (Sweden)

    B Sajeewa Amaradasa

    Full Text Available Pathogen exposure to sublethal doses of fungicides may result in mutations that may represent an important and largely overlooked mechanism of introducing new genetic variation into strictly clonal populations, including acquisition of fungicide resistance. We tested this hypothesis using the clonal plant pathogen, Sclerotinia sclerotiorum. Nine susceptible isolates were exposed independently to five commercial fungicides with different modes of action: boscalid (respiration inhibitor, iprodione (unclear mode of action, thiophanate methyl (inhibition of microtubulin synthesis and azoxystrobin and pyraclostrobin (quinone outside inhibitors. Mycelium of each isolate was inoculated onto a fungicide gradient and sub-cultured from the 50-100% inhibition zone for 12 generations and experiment repeated. Mutational changes were assessed for all isolates at six neutral microsatellite (SSR loci and for a subset of isolates using amplified fragment length polymorphisms (AFLPs. SSR analysis showed 12 of 85 fungicide-exposed isolates had a total of 127 stepwise mutations with 42 insertions and 85 deletions. Most stepwise deletions were in iprodione- and azoxystrobin-exposed isolates (n = 40/85 each. Estimated mutation rates were 1.7 to 60-fold higher for mutated loci compared to that expected under neutral conditions. AFLP genotyping of 33 isolates (16 non-exposed control and 17 fungicide exposed generated 602 polymorphic alleles. Cluster analysis with principal coordinate analysis (PCoA and discriminant analysis of principal components (DAPC identified fungicide-exposed isolates as a distinct group from non-exposed control isolates (PhiPT = 0.15, P = 0.001. Dendrograms based on neighbor-joining also supported allelic variation associated with fungicide-exposure. Fungicide sensitivity of isolates measured throughout both experiments did not show consistent trends. For example, eight isolates exposed to boscalid had higher EC50 values at the end of the

  12. Effects of Sublethal Fungicides on Mutation Rates and Genomic Variation in Fungal Plant Pathogen, Sclerotinia sclerotiorum

    Science.gov (United States)

    Amaradasa, B. Sajeewa

    2016-01-01

    Pathogen exposure to sublethal doses of fungicides may result in mutations that may represent an important and largely overlooked mechanism of introducing new genetic variation into strictly clonal populations, including acquisition of fungicide resistance. We tested this hypothesis using the clonal plant pathogen, Sclerotinia sclerotiorum. Nine susceptible isolates were exposed independently to five commercial fungicides with different modes of action: boscalid (respiration inhibitor), iprodione (unclear mode of action), thiophanate methyl (inhibition of microtubulin synthesis) and azoxystrobin and pyraclostrobin (quinone outside inhibitors). Mycelium of each isolate was inoculated onto a fungicide gradient and sub-cultured from the 50–100% inhibition zone for 12 generations and experiment repeated. Mutational changes were assessed for all isolates at six neutral microsatellite (SSR) loci and for a subset of isolates using amplified fragment length polymorphisms (AFLPs). SSR analysis showed 12 of 85 fungicide-exposed isolates had a total of 127 stepwise mutations with 42 insertions and 85 deletions. Most stepwise deletions were in iprodione- and azoxystrobin-exposed isolates (n = 40/85 each). Estimated mutation rates were 1.7 to 60-fold higher for mutated loci compared to that expected under neutral conditions. AFLP genotyping of 33 isolates (16 non-exposed control and 17 fungicide exposed) generated 602 polymorphic alleles. Cluster analysis with principal coordinate analysis (PCoA) and discriminant analysis of principal components (DAPC) identified fungicide-exposed isolates as a distinct group from non-exposed control isolates (PhiPT = 0.15, P = 0.001). Dendrograms based on neighbor-joining also supported allelic variation associated with fungicide-exposure. Fungicide sensitivity of isolates measured throughout both experiments did not show consistent trends. For example, eight isolates exposed to boscalid had higher EC50 values at the end of the experiment

  13. Exposure to sublethal blast overpressure reduces the food intake and exercise performance of rats.

    Science.gov (United States)

    Bauman, R A; Elsayed, N; Petras, J M; Widholm, J

    1997-07-25

    Exposure to blast overpressure can typically inflict generalized damage on major organ systems, especially gas-containing organs such as the lungs and the gastrointestinal tract. The purpose of the present study was to use rat's food intake and exercise wheel running as behavioral correlates of the perhaps more subtle damage to these organ systems induced by sublethal blast overpressure. Toward this end, all rats were exposed to a 12-h light/dark cycle and food was available only in the dark period. Prior to exposure, rats in the (E)xercise group were required to execute five rotations of an activity wheel for a food pellet; wheel turns that occurred at times other than when a rat was feeding were recorded separately and labeled exercise running. In the (S)edentary and (A)nesthesia groups, wheel running was not possible and rats were required to execute five leverpresses for a single pellet. A compressed air-driven shock tube was used to expose rats to a supra-atmospheric wave of air pressure. The tube was separated into two sections by a polyester membrane, the thickness of which determined peak and duration of overpressure. All rats were anesthetized with 50 mg/kg of phenobarbital. After reaching a deep plane of anesthesia, they were individually tied in a stockinet across one end of the shock tube. In preliminary tests, the membrane thickness was 1000 (A)ngstroms and rats in Group L(ethality) were exposed to a 129 kPa (peak amplitude) wave of overpressure. Three of six rats survived exposure to this peak pressure; pathology was evident in the lungs and gastrointestinal tract of all non-survivors. Rats in Groups E and S were tested with a 500 A membrane, which resulted in an 83 kPa peak amplitude. All rats survived exposure to this lower peak pressure. On the day of exposure to blast, the relative reduction of intake during the first 3 h of the dark period was significantly greater for Group E than for Groups S and A; the intake of Groups E and S remained reduced

  14. Effect of UV irradiation on the proportion of organic chloramines in total chlorine in subsequent chlorination.

    Science.gov (United States)

    Zhang, Tian-Yang; Lin, Yi-Li; Xu, Bin; Xia, Sheng-Ji; Tian, Fu-Xiang; Gao, Nai-Yun

    2016-02-01

    This study investigated the changes of chlorine species and proportion of organic chloramines during the chlorination process after UV irradiation pretreatment in drinking water. It was found that the UV pretreatment could enhance the percentage of organic chloramines by increasing free chlorine consumption in the chlorination of raw waters. The percentage of organic chloramines in total chlorine increased with UV intensity and irradiation time in raw waters. However, for the humic acid synthesized water, the percentage of organic chloramines increased first and then decreased with the increase of UV irradiation time. The value of SUVA declined in both raw and humic acid synthesized waters over the UV irradiation time, which indicated that the decomposition of aromatic organic matter by UV could be a contributor to the increase of free chlorine consumption and organic chloramine proportion. The percentage of organic chloramines during chlorination of raw waters after 30-min UV irradiation pretreatment varied from 20.2% to 41.8%. Total chlorine decreased obviously with the increase of nitrate concentration, but the percentage of organic chloramines increased and was linearly correlated to nitrate concentration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Kinetic analysis of the swimming behavior of the goldfish, Carassius auratus, exposed to nickel: Hypoactivity induced by sublethal concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Ellgaard, E.G.; Ashley, S.E.; Langford, A.E. [Tulane Univ., New Orleans, LA (United States)] [and others

    1995-12-01

    The discharge of nickel into aquatic environments from numerous industries poses a threat to fish populations because of its toxcity. Although little is known, however, about the precise mechanism of its toxicity in freshwater fish, it produces some of the symptoms associated with heavy-metal poisoning in general; it accumulates in fish tissues and results in alterations in gill structure, including hypertrophy of respiratory and mucous cells, separation of the epithelial layer from the pillar cell system, cauterization and sloughing, and necrosis of the epithelium. The destruction of the gill lamellae decreases the ventilation rate and if severe, as after acute exposure, may cause blood hypoxia and death. The effects of short-term exposure of fish to sublethal concentrations of nickel and not as well defined. The kinetic method of Ellgaard et al., which uses locomotor activity to assess the general health of fish, is ideally suited to examine whether sublethal concentrations of nickel adversely affect fish. In previous studies, the measured changes in locomotor activity observed when fish are exposed to pollutants correlate with more specific changes, e.g., physiological, biochemical, histological or neurosensory changes, which occur under the same conditions. Thus, the kinetic method also meets the criterial for pollution early warning systems as discussed by Cairns and van der Schale. This method has previously been used to demonstrate that short-term exposure to sublethal concentrations of the heavy metals cadmium, chromium, and zinc and copper are detrimental to the health of bluegills. The present study examines the effects of short-term exposures of sublethal concentrations of nickel on the locomotor activity of the goldfish, Carassius auratus. 11 refs., 1 fig., 2 tabs.

  16. Do biopesticides affect the demographic traits of a parasitoid wasp and its biocontrol services through sublethal effects?

    Directory of Open Access Journals (Sweden)

    Antonio Biondi

    Full Text Available Pesticide risk assessments are usually based on short-term acute toxicity tests, while longer-term population dynamic related traits, critical to the success of biological control and Integrated Pest Management (IPM programs, are often overlooked. This is increasingly important with respect to new biopesticides that frequently cause no short-term acute effects, but that can induce multiple physiological and behavioral sublethal effects, leading to a decrease in population growth and ecosystem services. In this study we assessed the lethal and sublethal effects of six biopesticides [abamectin, azadirachtin, Bacillus thuringiensis, borax plus citrus oil (Prev-Am®, emamectin benzoate, and spinosad], used in tomato crops to control the invasive pest Tuta absoluta (Lepidoptera: Gelechiidae, on adults and pupae of the parasitoid Bracon nigricans (Hymenoptera: Braconidae. Data on female survival and production of female offspring were used to calculate population growth indexes as a measure of population recovery after pesticide exposure. Spinosad caused 100% and 80% mortality in exposed adults (even 10 d after the treatment and pupae, respectively. Although most of the biopesticides had low levels of acute toxicity, multiple sublethal effects were observed. The biocontrol activity of both females that survived 1-h and 10-d old residues, and females that emerged from topically treated pupae was significantly affected by the application of the neurotoxic insecticides emamectin benzoate and abamectin. Furthermore, very low B. nigricans demographic growth indices were estimated for these two insecticides, indicating potential local extinction of the wasp populations. Among the tested products, Bt proved to be the safest for B. nigricans adults and pupae. Our findings emphasize that acute toxicity assessment alone cannot fully predict the actual impact of pesticides on non-target parasitoids. Thus, sublethal effects related to the species specific life

  17. Do Biopesticides Affect the Demographic Traits of a Parasitoid Wasp and Its Biocontrol Services through Sublethal Effects?

    Science.gov (United States)

    Biondi, Antonio; Zappalà, Lucia; Stark, John D.; Desneux, Nicolas

    2013-01-01

    Pesticide risk assessments are usually based on short-term acute toxicity tests, while longer-term population dynamic related traits, critical to the success of biological control and Integrated Pest Management (IPM) programs, are often overlooked. This is increasingly important with respect to new biopesticides that frequently cause no short-term acute effects, but that can induce multiple physiological and behavioral sublethal effects, leading to a decrease in population growth and ecosystem services. In this study we assessed the lethal and sublethal effects of six biopesticides [abamectin, azadirachtin, Bacillus thuringiensis, borax plus citrus oil (Prev-Am®), emamectin benzoate, and spinosad], used in tomato crops to control the invasive pest Tuta absoluta (Lepidoptera: Gelechiidae), on adults and pupae of the parasitoid Bracon nigricans (Hymenoptera: Braconidae). Data on female survival and production of female offspring were used to calculate population growth indexes as a measure of population recovery after pesticide exposure. Spinosad caused 100% and 80% mortality in exposed adults (even 10 d after the treatment) and pupae, respectively. Although most of the biopesticides had low levels of acute toxicity, multiple sublethal effects were observed. The biocontrol activity of both females that survived 1-h and 10-d old residues, and females that emerged from topically treated pupae was significantly affected by the application of the neurotoxic insecticides emamectin benzoate and abamectin. Furthermore, very low B. nigricans demographic growth indices were estimated for these two insecticides, indicating potential local extinction of the wasp populations. Among the tested products, Bt proved to be the safest for B. nigricans adults and pupae. Our findings emphasize that acute toxicity assessment alone cannot fully predict the actual impact of pesticides on non-target parasitoids. Thus, sublethal effects related to the species specific life-history variables

  18. Sublethal doses of the pesticide imidacloprid alter honey bee (Apis mellifera) response threshold and navigation, potentially affecting colony health

    OpenAIRE

    Eiri, Daren

    2011-01-01

    Much attention on honey bee declines has focused on the sublethal effects the pesticide, imidacloprid, has on honey bee behavior. How it affects individual foragers and their preference for nectar or their ability to navigate to communicated food sources is unknown. We use the proboscis extension reflex (PER) assay to test an individual's response threshold. Bees treated with the pesticide have higher response thresholds and respond less often to high concentrations of sucrose than control be...

  19. Thermal inactivation and sublethal injury kinetics of Salmonella enterica and Listeria monocytogenes in broth versus agar surface.

    Science.gov (United States)

    Wang, Xiang; Devlieghere, Frank; Geeraerd, Annemie; Uyttendaele, Mieke

    2017-02-21

    The objective of the present study was to compare the thermal inactivation and sublethal injury kinetics of Salmonella enterica and Listeria monocytogenes in broth (suspended cells) and on solid surface (agar-seeded cells). A 3-strain cocktail of S. enterica or L. monocytogenes inoculated in broth or on agar was subjected to heating in a water bath at various set temperatures (55.0, 57.5 and 60.0°C for S. enterica and 60.0, 62.5 and 65°C for L. monocytogenes). The occurrence of sublethally injured cells was determined by comparing enumerations on nonselective (TSAYE) and selective (XLD or ALOA) media. Results showed that the inactivation curves obtained from selective media were log-linear, and significant shoulders (pagar surface exhibited higher heat resistance than those in broth. For S. enterica, cell injury increased with the exposure time, no difference was observed when treated at temperatures from 55.0 to 60.0°C, while for L. monocytogenes, cell injury increased significantly with heating time and treatment temperature (from 60.0 to 65°C). Moreover, the degree of sublethal injury affected by thermal treatment in broth or on agar surface depended upon the target microorganism. Higher proportions of injured S. enterica cells were observed for treatment in broth than on agar surface, while the opposite was found for L. monocytogenes. The provided information may be used to assess the efficacy of thermal treatment processes on surfaces for inactivation of S. enterica and L. monocytogenes, and it provides insight into the sublethally injured survival state of S. enterica and L. monocytogenes treated in liquid or on solid food. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Sub-lethal doses of photodynamic therapy affect biofilm formation ability and metabolic activity of Enterococcus faecalis.

    Science.gov (United States)

    Pourhajibagher, M; Chiniforush, N; Shahabi, S; Ghorbanzadeh, R; Bahador, A

    2016-09-01

    During photodynamic therapy (PDT) in the treatment of a primary endodontic infection, it is extremely likely that microorganisms would be exposed to sub-lethal doses of PDT (sPDT). Although sPDT cannot kill microorganisms, it can considerably influence microbial virulence. This study was conducted to characterize the effect of sPDT using toluidine blue O (TBO), methylene blue (MB), and indocyanine green (ICG) on biofilm formation ability and metabolic activity of Enterococcus faecalis. The antimetabolic and antibiofilm potential of ICG-, TBO-, and MB-sPDT against E. faecalis was analyzed at sub-lethal doses (1/2-1/64 minimum inhibitory concentration) using the XTT reduction assay, crystal violet assay, and scanning electron microscopy. Higher doses of sPDT adversely affected biofilm formation ability and metabolic activity. ICG-, TBO-, and MB-PDT at a maximum sub-lethal dose markedly reduced the formation of biofilm up to 42.8%, 22.6%, and 19.5%, respectively. ICG-, TBO-, and MB-sPDT showed a marked reduction in bacterial metabolic activity by 98%, 94%, and 82%, respectively. ICG-PDT showed a stronger inhibitory effect on biofilm formation in E. faecalis than MB- and TBO-PDT at sub-lethal levels. Interestingly, a gradual increase in metabolic activity and biofilm formation upon exposure to a lower dose of test sPDT were observed. sPDT showed dual effect on biofilm formation ability and metabolic activity of E. faecalis. High doses revealed antimetabolic and antibiofilm potential activity, whereas lower doses had conflicting results. Hence, when PDT is prescribed in clinical settings, the dose of PDT used in vivo should be taken into consideration. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Sublethal Exposure to Diatomaceous Earth Increases Net Fecundity of Flour Beetles (Tribolium confusum) by Inhibiting Egg Cannibalism

    OpenAIRE

    Shostak, Allen W.

    2014-01-01

    Population regulation results from an interplay of numerous intrinsic and external factors, and for many insects cannibalism is such a factor. This study confirms a previously-reported observation that sublethal exposure to the fossilized remains of diatoms (i.e. diatomaceous earth) increases net fecundity (eggs produced minus eggs destroyed/day) of flour beetles, Tribolium confusum. The aim was to experimentally test two non-mutually-exclusive ecological mechanisms potentially responsible fo...

  2. CXCL12 expression in hematopoietic tissues of mice exposed to sublethal dose of ionizing radiation in the presence od iNOS inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Perez Vieira, Daniel [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Lab. de Biologia Molecular; Hermida, Felipe Pessoa de Melo; Andrade Junior, Heitor Franco de [Instituto de Medicina Tropical de Sao Paulo, SP (Brazil). Lab. de Protozoologia

    2005-07-01

    Full text of publication follows: We study the production of CXCL12, a stem cell homing chemokine, in spleen and bone marrow of mice exposed at LD50% of {gamma}-radiation, w/wo a iNOS blocker, aminoguanidine, to test if inflammatory nitric oxide is involved in necrotic processes of stem cell death after ionizing radiation exposure. Groups of 10 male 6-week old C57Bl/6j mice were killed at specific time points after a 8Gy dose irradiation ({sup 60}Co source; 4,22kGy/h dose rate) and spleen and bone marrow samples were immersed and stored in TriZOL for total mRNA extraction. RT-PCR assays were performed to determine the production of CXCL12 as compared to murine {beta}-actin at days 2nd, 5th, 7th, 9th and 15th days after radiation in a semiquantitative way. PCR was performed after cDNA synthesis using Oligo-dT primers and specific primers for CXCL12 and {beta}-actin. Artificial optical density was determined in silver-stained PAGE resolved specific amplification products of CXCL12, using amplification of murine {beta}-actin as standard, and measurements obtained by the Image J freeware. CXCL12 production in spleen samples reached its maximum at 5th day after radiation exposure in animals not treated with aminoguanidine, but this peak was extended to at 7th day in treated animals. Non treated animals presented a decrease of CXCL12 expression up to 15th day of experiment, and aminoguanidine treated animals showed sustained increase of expression levels between 9th and 15th days. In bone marrow samples, the main difference among the two different experimental groups was a maintenance of CXCL12 mRNA expression between 7th and 9th days, persisting until the end of the experiment. Our data demonstrates that the effect of aminoguanidine appears to sustain the CXCL12 mRNA synthesis in hematopoietic tissues of irradiated mice, providing some evidences that the axis iNOS -NO - inflammation must be involved in stem cell death, aside to the direct radiation effect, suggesting

  3. Sub-Lethal Dose of Shiga toxin 2 from Enterohemorrhagic Escherichia coli Affects Balance and Cerebellar Cythoarquitecture.

    Directory of Open Access Journals (Sweden)

    Luciana eD’Alessio

    2016-02-01

    Full Text Available Shiga toxin producing Escherichia coli may damage the central nervous system before or concomitantly to manifested hemolytic uremic syndrome symptoms. The cerebellum is frequently damaged during this syndrome, however the deleterious effects of Shiga toxin 2 has never been integrally reported by ultrastructural, physiological and behavioral means. The aim of this study was to determine the cerebellar compromise after intravenous administration of a sub-lethal dose of Shiga toxin 2 by measuring the cerebellar blood brain barrier permeability, behavioral task of cerebellar functionality (inclined plane test, and ultrastructural analysis (transmission electron microscope. Intravenous administration of vehicle (control group, sub-lethal dose of 0.5 ηg and 1 ηg of Stx2 per mouse were tested for behavioral and ultrastructural studies. A set of three independent experiments were performed for each study (n=6. Blood–Brain Barrier resulted damaged and consequently its permeability was significantly increased. Lower scores obtained in the inclined plane task denoted poor cerebellar functionality in comparison to their controls. The most significant lower score was obtained after 5 days of 1ηg of toxin administration. Transmission electron microscope micrographs from the Stx2-treated groups showed neurons with a progressive neurodegenerative condition in a dose dependent manner. As sub-lethal intravenous Shiga toxin 2 altered the blood brain barrier permeability in the cerebellum the toxin penetrated the cerebellar parenchyma and produced cell damaged with significant functional implications in the test balance.

  4. Protective effect of milk constituents and sublethal injuries limiting process effectiveness during PEF inactivation of Lb. rhamnosus.

    Science.gov (United States)

    Jaeger, H; Schulz, A; Karapetkov, N; Knorr, D

    2009-08-31

    The inactivation of Lb. rhamnosus by pulsed electric field treatment (PEF) was studied in different fractions of raw milk and Ringer solution in order to evaluate the protective effect of nutrient rich media in comparison to aqueous buffer solutions. Apart from monitoring of culturability, analysis of the physiological fitness of Lb. rhamnosus was conducted aiming to identify sublethally damaged cells. Therefore, flow cytometry and a selective medium plating technique were used and compared to each other. The goal of the study was to apply three different parameters describing the physiological fitness of the model organism Lb. rhamnosus after PEF treatment such as culturability, membrane permeability and metabolic activity depending on treatment media and parameters. A concentration dependent protective effect of the milk protein fraction could be shown and allocated to micellar casein as the major milk protein. Increasing the concentration of whey proteins up to 2% showed a similar impact on limiting the PEF inactivation of Lb. rhamnosus. The evaluation of physiological fitness of cells was based on a determination of structural and functional characteristics by rapid cellular staining using carboxyfluorescein diacetate and propidium iodide. This approach showed good accordance to the conventional selective medium plating technique for the enumeration of sublethally-injured bacteria but flow cytometry provided additional information for the characterisation of this fraction. The extent of occurrence of dead, sublethal and vital fractions of cells was found dependent on the PEF treatment parameters such as electrical field strength and energy input as well as the different milk fractions used as treatment media.

  5. Acute Toxicity and Sublethal Effects of Terpenoids and Essential Oils on the Predator Chrysoperla externa (Neuroptera: Chrysopidae).

    Science.gov (United States)

    Castilhos, R V; Grützmacher, A D; Coats, J R

    2017-07-31

    The search for new safer insecticides has increased in recent agriculture. Botanical compounds such as terpenoids and plant essential oils with insecticidal activity could represent important tools in pest management, and their risk assessment against non-target organisms is necessary since they may serve as a precursor for the synthesis of new insecticide active ingredients. For this study, the acute toxicity and sublethal effects of seven terpenoids and three essential oils with recognized insecticidal activity were evaluated on the predator Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) in laboratory bioassays. Results indicate that these compounds feature relative selectivity to the predator C. externa; however, sublethal effects on reproduction were recorded for some compounds. The phenolic monoterpenoids carvacrol and thymol were more acutely toxic than other terpenoids screened, with LD 50 <20,000 μg/g; however, they were less toxic than natural pyrethrins (toxicity standard) in these bioassays. Sublethal effects on fecundity and fertility were observed for R-(+)-limonene, while oregano oil only affected fecundity. The compounds evaluated here have potential to be used as insecticides and can serve as backbone for future synthesis of selective active ingredients; however, a complete risk assessment to C. externa and other non-target organisms is necessary for their incorporation in future crop protection paradigms.

  6. Lethal and Sublethal Effects of Some Chemical and Biological Insecticides on Tuta absoluta (Lepidoptera: Gelechiidae) Eggs and Neonates.

    Science.gov (United States)

    Nozad-Bonab, Z; Hejazi, M J; Iranipour, Sh; Arzanlou, M

    2017-06-01

    Tuta absoluta (Meyrick) is one of the serious pests of tomatoes. This study was conducted to evaluate the effects of some chemical and biological insecticides on T. absoluta. The insecticides tested were diazinon, dichlorvos, chlorantraniliprole, deltamethrin, acetamiprid, imidacloprid, spinosad, abamectin, indoxacarb, Bacillus thuringiensis Berliner, Beauveria bassiana (Balsamo) Vuillemin, and Metarhizium anisopliae (Metschnikoff) Sorokin. Sublethal effects for the most effective insecticides tested, namely, abamectin, spinosad, chlorantraniliprole, and indoxacarb were assessed, and life table parameters were calculated. Chlorantraniliprole had the highest lethal effect on T. absoluta followed by spinosad, abamectin, and indoxacarb. On the other hand, imidacloprid was not considerably effective on T. absoluta eggs. Metarhizium anisopliae was 11 and 518 times more effective on the eggs and newly hatched larvae than B. bassiana and B. thuringiensis, respectively. Chlorantraniliprole, spinosad, abamectin, and indoxacarb affected life table parameters of T. absoluta significantly (α = 0.05). Spinosad had the highest sublethal effect on T. absoluta followed by abamectin, chlorantraniliprole, and indoxacarb. The results revealed that chlorantraniliprole, spinosad, abamectin, and indoxacarb had considerable lethal and sublethal effects on T. absoluta, and if they perform similarly in commercial greenhouses and fields, they would be suitable candidates to be considered in IPM programs for this pest. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. The Wiggle Index: An Open Source Bioassay to Assess Sub-Lethal Insecticide Response in Drosophila melanogaster.

    Science.gov (United States)

    Denecke, Shane; Nowell, Cameron J; Fournier-Level, Alexandre; Perry, Trent; Batterham, Phil

    2015-01-01

    Toxicological assays measuring mortality are routinely used to describe insecticide response, but sub-lethal exposures to insecticides can select for resistance and yield additional biological information describing the ways in which an insecticide impacts the insect. Here we present the Wiggle Index (WI), a high-throughput method to quantify insecticide response by measuring the reduction in motility during sub-lethal exposures in larvae of the vinegar fly Drosophila melanogaster. A susceptible wild type strain was exposed to the insecticides chlorantraniliprole, imidacloprid, spinosad, and ivermectin. Each insecticide reduced larval motility, but response times and profiles differed among insecticides. Two sets of target site mutants previously identified in mortality studies on the basis of imidacloprid or spinosad resistance phenotypes were tested. In each case the resistant mutant responded significantly less than the control. The WI was also able to detect a spinosad response in the absence of the primary spinosad target site. This response was not detected in mortality assays suggesting that spinosad, like many other insecticides, may have secondary targets affecting behaviour. The ability of the WI to detect changes in insecticide metabolism was confirmed by overexpressing the imidacloprid metabolizing Cyp6g1 gene in digestive tissues or the central nervous system. The data presented here validate the WI as an inexpensive, generic, sub-lethal assay that can complement information gained from mortality assays, extending our understanding of the genetic basis of insecticide response in D. melanogaster.

  8. Does selective logging stress tropical forest invertebrates? Using fat stores to examine sublethal responses in dung beetles.

    Science.gov (United States)

    França, Filipe; Barlow, Jos; Araújo, Bárbara; Louzada, Julio

    2016-12-01

    The increased global demand for tropical timber has driven vast expanses of tropical forests to be selectively logged worldwide. While logging impacts on wildlife are predicted to change species distribution and abundance, the underlying physiological responses are poorly understood. Although there is a growing consensus that selective logging impacts on natural populations start with individual stress-induced sublethal responses, this literature is dominated by investigations conducted with vertebrates from temperate zones. Moreover, the sublethal effects of human-induced forest disturbance on tropical invertebrates have never been examined. To help address this knowledge gap, we examined the body fat content and relative abundance of three dung beetle species (Coleoptera: Scarabaeinae) with minimum abundance of 40 individuals within each examined treatment level. These were sampled across 34 plots in a before-after control-impact design (BACI) in a timber concession area of the Brazilian Amazon. For the first time, we present evidence of logging-induced physiological stress responses in tropical invertebrates. Selective logging increased the individual levels of fat storage and reduced the relative abundance of two dung beetle species. Given this qualitative similarity, we support the measurement of body fat content as reliable biomarker to assess stress-induced sublethal effects on dung beetles. Understanding how environmental modification impacts the wildlife has never been more important. Our novel approach provides new insights into the mechanisms through which forest disturbances impose population-level impacts on tropical invertebrates.

  9. {sup 1}H NMR metabolomics of earthworm exposure to sub-lethal concentrations of phenanthrene in soil

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Sarah A.E.; McKelvie, Jennifer R.; Simpson, Andre J. [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail Toronto, Ontario, M1C 1A4 (Canada); Simpson, Myrna J., E-mail: myrna.simpson@utoronto.c [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail Toronto, Ontario, M1C 1A4 (Canada)

    2010-06-15

    {sup 1}H NMR metabolomics was used to monitor earthworm responses to sub-lethal (50-1500 mg/kg) phenanthrene exposure in soil. Total phenanthrene was analyzed via soxhlet extraction, bioavailable phenanthrene was estimated by hydroxypropyl-beta-cyclodextrin (HPCD) and 1-butanol extractions and sorption to soil was assessed by batch equilibration. Bioavailable phenanthrene (HPCD-extracted) comprised approx65-97% of total phenanthrene added to the soil. Principal component analysis (PCA) showed differences in responses between exposed earthworms and controls after 48 h exposure. The metabolites that varied with exposure included amino acids (isoleucine, alanine and glutamine) and maltose. PLS models indicated that earthworm response is positively correlated to both total phenanthrene concentration and bioavailable (HPCD-extracted) phenanthrene in a freshly spiked, unaged soil. These results show that metabolomics is a powerful, direct technique that may be used to monitor contaminant bioavailability and toxicity of sub-lethal concentrations of contaminants in the environment. These initial findings warrant further metabolomic studies with aged contaminated soils. - {sup 1}H NMR metabolomics is used to directly monitor metabolic responses of Eisenia fetida after 48 h of exposure to sub-lethal concentrations of phenanthrene in soil.

  10. Sub-Lethal Dose of Shiga Toxin 2 from Enterohemorrhagic Escherichia coli Affects Balance and Cerebellar Cytoarchitecture

    Science.gov (United States)

    Pinto, Alipio; Cangelosi, Adriana; Geoghegan, Patricia A.; Tironi-Farinati, Carla; Brener, Gabriela J.; Goldstein, Jorge

    2016-01-01

    Shiga toxin producing Escherichia coli may damage the central nervous system before or concomitantly to manifested hemolytic–uremic syndrome symptoms. The cerebellum is frequently damaged during this syndrome, however, the deleterious effects of Shiga toxin 2 has never been integrally reported by ultrastructural, physiological and behavioral means. The aim of this study was to determine the cerebellar compromise after intravenous administration of a sub-lethal dose of Shiga toxin 2 by measuring the cerebellar blood–brain barrier permeability, behavioral task of cerebellar functionality (inclined plane test), and ultrastructural analysis (transmission electron microscope). Intravenous administration of vehicle (control group), sub-lethal dose of 0.5 and 1 ηg of Stx2 per mouse were tested for behavioral and ultrastructural studies. A set of three independent experiments were performed for each study (n = 6). Blood–brain barrier resulted damaged and consequently its permeability was significantly increased. Lower scores obtained in the inclined plane task denoted poor cerebellar functionality in comparison to their controls. The most significant lower score was obtained after 5 days of 1 ηg of toxin administration. Transmission electron microscope micrographs from the Stx2-treated groups showed neurons with a progressive neurodegenerative condition in a dose dependent manner. As sub-lethal intravenous Shiga toxin 2 altered the blood brain barrier permeability in the cerebellum the toxin penetrated the cerebellar parenchyma and produced cell damaged with significant functional implications in the test balance. PMID:26904009

  11. The Effect of Acclimation to Sublethal Temperature on Subsequent Susceptibility of Sitophilus zeamais Mostchulsky (Coleoptera: Curculionidae) to High Temperatures.

    Science.gov (United States)

    Lü, Jianhua; Zhang, Huina

    2016-01-01

    Heat treatment is a popular alternative to synthetic pesticides in disinfesting food-processing facilities and empty grain storages. Sitophilus zeamais Mostchulsky is one of the most cosmopolitan and destructive insects found in empty grain storage facilities and processing facilities. The effect of acclimation in S. zeamais adults to sublethal high temperature on their subsequent susceptibility to high temperatures was investigated. S. zeamais adults were acclimated to 36°C for 0 (as a control), 1, 3, and 5 h, and then were exposed at 43, 47, 51, and 55°C for different time intervals respectively. Acclimation to sublethal high temperature significantly reduced subsequent susceptibility of S. zeamais adults to lethal high temperatures of 43, 47, 51, and 55°C, although the mortality of S. zeamais adults significantly increased with increasing exposure time at lethal high temperatures. The mortality of S. zeamais adults with 1, 3, and 5 h of acclimation to 36°C was significantly lower than that of S. zeamais adults without acclimation when exposed to the same lethal high temperatures. The present results suggest that the whole facility should be heated to target lethal high temperature as soon as possible, avoiding decreasing the control effectiveness of heat treatment due to the acclimation in stored product insects to sublethal temperature.

  12. Strengths, challenges, and opportunities for hydrothermal pretreatment in lignocellulosic biorefineries: Hydrothermal Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bin [Bioproducts, Sciences, and Engineering Laboratory, Department of Biological Systems Engineering, Washington State University, Richland WA USA; Tao, Ling [National Bioenergy Center, National Renewable Energy Laboratory, Golden CO USA; Wyman, Charles E. [Chemical and Environmental Engineering Department and Center for Environmental Research and Technology, Bourns College of Engineering, University of California at Riverside, CA, USA, BioEnergy Science Center (BESC), Oak Ridge National Laboratory, TN USA

    2017-10-11

    Pretreatment prior to or during biological conversion is required to achieve high sugar yields essential to economic production of fuels and chemicals from low cost, abundant lignocellulosic biomass. Aqueous thermochemical pretreatments achieve this performance objective from pretreatment coupled with subsequent enzymatic hydrolysis, but chemical pretreatment can also suffer from additional costs for exotic materials of construction, the need to recover or neutralize the chemicals, introduction of compounds that inhibit downstream operations, and waste disposal, as well as for the chemicals themselves. The simplicity of hydrothermal pretreatment with just hot water offers the potential to greatly improve the cost of the entire conversion process if sugar degradation during pretreatment, production of un-fermentable oligomers, and the amount of expensive enzymes needed to obtain satisfactory yields from hydrothermally pretreated solids can be reduced. Biorefinery economics would also benefit if value could be generated from lignin and other components that are currently fated to be burned for power. However, achieving these goals will no doubt require development of advanced hydrothermal pretreatment configurations. For example, passing water through a stationary bed of lignocellulosic biomass in a flowthrough configuration achieves very high yields of hemicellulose sugars, removes more than 75% of the lignin for potential valorization, and improves sugar release from the pretreated solids with lower enzyme loadings. Unfortunately, the large quantities of water needed to achieve this performance result in very dilute sugars, high energy costs for pretreatment and product recover, and large amounts of oligomers. Thus, improving our understanding of hydrothermal pretreatment fundamentals is needed to gain insights into R&D opportunities to improve performance, and help identify novel configurations that lower capital and operating costs and achieve higher yields.

  13. AGC-2 Irradiation Report

    Energy Technology Data Exchange (ETDEWEB)

    Rohrbaugh, David Thomas [Idaho National Lab. (INL), Idaho Falls, ID (United States); Windes, William [Idaho National Lab. (INL), Idaho Falls, ID (United States); Swank, W. David [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-06-01

    The Next Generation Nuclear Plant (NGNP) will be a helium-cooled, very high temperature reactor (VHTR) with a large graphite core. In past applications, graphite has been used effectively as a structural and moderator material in both research and commercial high temperature gas cooled reactor (HTGR) designs.[ , ] Nuclear graphite H 451, used previously in the United States for nuclear reactor graphite components, is no longer available. New nuclear graphites have been developed and are considered suitable candidates for the new NGNP reactor design. To support the design and licensing of NGNP core components within a commercial reactor, a complete properties database must be developed for these current grades of graphite. Quantitative data on in service material performance are required for the physical, mechanical, and thermal properties of each graphite grade with a specific emphasis on data related to the life limiting effects of irradiation creep on key physical properties of the NGNP candidate graphites. Based on experience with previous graphite core components, the phenomenon of irradiation induced creep within the graphite has been shown to be critical to the total useful lifetime of graphite components. Irradiation induced creep occurs under the simultaneous application of high temperatures, neutron irradiation, and applied stresses within the graphite components. Significant internal stresses within the graphite components can result from a second phenomenon—irradiation induced dimensional change. In this case, the graphite physically changes i.e., first shrinking and then expanding with increasing neutron dose. This disparity in material volume change can induce significant internal stresses within graphite components. Irradiation induced creep relaxes these large internal stresses, thus reducing the risk of crack formation and component failure. Obviously, higher irradiation creep levels tend to relieve more internal stress, thus allowing the

  14. Sublethal effects of atrazine on embryo-larval development of Rhinella arenarum (Anura: Bufonidae).

    Science.gov (United States)

    Svartz, Gabriela V; Herkovits, Jorge; Pérez-Coll, Cristina S

    2012-05-01

    Atrazine (ATR), one of the most widely used herbicides in the world, affects not only target organisms but also the biota in general. Here, the teratogenic and neurotoxic effects of ATR on Rhinella arenarum (South American toad) embryos, and larvae were evaluated by means of standardized bioassays during acute and chronic exposures. The herbicide had a significant incidence of malformations, with a Teratogenic Index (TI) of 3.28. The main effects were delayed development, reduced body size, microcephaly, axial flexures, wavy tail and edema. In addition, delayed development, reduced development of forelimbs, and edema were recorded at metamorphosis stages. Scanning electron microscopy allowed observing different degrees of cellular dissociation and persistent cilliar cells in specific regions like the adhesive structure and tail fin. Results obtained by ATR 24 h pulse exposures at six developmental stages pointed out blastula as the most susceptible developmental stage both for immediate and delayed adverse effects. A noteworthy recovery capacity from acute toxic effects was recorded from the neural plate stage onwards. Regarding neurotoxic effects, abnormal, and erratic swimming and spasmodic contractions were recorded. Both the teratogenic and neurotoxic effects reported in this study demonstrate the importance of evaluating sublethal effects in non-target organisms as they could imply reduced fitness of individuals and eventually a population decline. The Hazard Quotients (HQ) for ATR ranged from 0.14 to 10.80, and the fact that some of these values are above USEPA's level of concern indicate that ATR is likely a risk to R. arenarum.

  15. Haematological, blood biochemical and histopathological effects of sublethal cadmium and lead concentrations in common carp

    Directory of Open Access Journals (Sweden)

    M.K.Khalesi

    2017-06-01

    Full Text Available The present research aimed at examining the effects of common carp (Cyprinus carpio exposure to sublethal concentrations of two non-essential heavy metals: cadmium (Cd: 8.4 mg/L and lead (Pb: 6.2 mg/L for 15 days to evaluate occurring biochemical and haematological effects. The examined parameters included haematocrit (Hct, haemoglobin (Hb, lymphocytes (Lym, neutrophils (Neu, total protein (TP, albumin (Alb, immunoglobulin M (IgM, glucose, red and white blood cells counts (RBC & WBC, mean corpuscular volume (MCV, mean corpuscular haemoglobin (MCH, and mean corpuscular haemoglobin concentration (MCHC. Exposure to both metals significantly (P<0.05 reduced the amounts of WBC and MCHC. MCV values decreased (P<0.05 after the Pb treatment but MCV estimates with Cd exposure showed no differences. MCH levels increased in both treatments (P<0.05 whereas Hct, Hb, RBC, Lym, and Neu following both metal exposures were almost similar to those in the control. IgM values were elevated in fish contaminated with both Pb and Cd (P<0.05. The exposed fish showed fusion of gill lamellae, vessel dilatation, hyperaemia, and hyperplasia of gill epithelial cells whereas muscle histology remained unchanged. The observed responses can be secondary to low heavy metals concentrations reflecting the trigger of stress reactions in affected fish

  16. The sub-lethal effects of repeated freezing in the woolly bear caterpillar Pyrrharctia isabella.

    Science.gov (United States)

    Marshall, Katie E; Sinclair, Brent J

    2011-04-01

    Repeated freeze-thaw cycles are common and are increasing in frequency with climate change in many temperate locations, yet understanding of their impact on freeze-tolerant insects is extremely limited. We investigated the effects of repeated freezing and thawing on the freeze-tolerant final instar caterpillars of the moth Pyrrharctia isabella (Lepidoptera: Arctiidae) by subjecting individuals to either a single sustained 35 h freeze or five 7 h freezes. Sub-lethal effects were quantified with changes in three broad groups of measures: (1) cold hardiness, (2) metabolic rate and energy reserves and (3) survival after challenge with fungal spores. Repeated freeze-thaw cycles increased mortality to almost 30% and increased tissue damage in Malpighian tubules and hemocytes. Repeated freezing increased caterpillar glycerol concentration by 0.82 mol l(-1). There were no changes in metabolic rate or energy reserves with repeated freezing. For the first time, we report increased survival after immune challenge in caterpillars after freezing and suggest that this may be linked to wounding during freezing. We suggest that little repair of freezing damage is possible in P. isabella caterpillars and repeated freeze-thaw cycles may present significant challenges to survival in this species.

  17. Sublethal Effects of Spirodiclofen on Tetranychus urticae Koch_Pre-Ovipositional Females After Different Exposure Times

    Directory of Open Access Journals (Sweden)

    Dejan Marčić

    2006-01-01

    Full Text Available Sublethal effect of spirodiclofen on Tetranychus urticae females that survived different exposure times in the pre-ovipositional period was evaluated calculating two parameters - instantaneous rate of increase and net fertility - after six days of reproduction. The females were exposed to four concentrations/doses of the acaricide: 96 mg /L (0.24 μg/cm2, 48 mg/L(0.12 μg/cm2, 24 mg/L (0.06 μg/cm2 and 12 mg./L (0.03 μg/cm2 for 2, 6 and 24h in a leaf disc bioassay. After 24h exposure to 12 mg/L, instantaneous rate of increase was significantlyreduced (0.545; 0.634 in control, while significant reduction in net fertility (20.61; 28.57 in the control was recorded even after 2h exposure to the same concentration. The effect of all tested concentrations of spirodiclofen on both parameters increased with exposure time. The lowest values of instantaneous rate of increase (0.268 and net fertility (2.58 were recorded after 24h exposure to 96 mg/L. After 24h exposure, the concentration increase from 12 to 24 mg/L significantly reduced both parameters, while a further increase from 24 to 96 mg/L significantly reduced instantaneous rate of increase, but not net-fertility. The results regarding T. urticae population management are discussed.

  18. Haematological changes in Bufo maculatus treated with sublethal concentrations of Cadmium

    Directory of Open Access Journals (Sweden)

    Lawrence Ikechukwu Ezemonye

    2011-12-01

    Full Text Available Adult Bufo maculatus was exposed to sublethal cadmium concentrations of 0.25, 0.50, 1.00 and 2.00 mg/L. The toxicant from which the cadmium concentrations were prepared was cadmium chloride (CdCl2.H2O. There were three replicate tanks per treatment and three individuals per tank including control groups. The hematologic alterations based on the examination of blood indices during the 28 days of exposure showed that total erythrocyte count (TEC, hematocrit (Hct and hemoglobin (Hb concentration decreased (P<0.05 relative to controls. The decline was concentration- dependent as concentration of cadmium increased. The decline in hemoglobin and hematocrit in the experimental organism could be due to a decrease in the synthesis or release of erythrocytes into the circulation or an increase in the rate of erythrocyte destruction inflicted by cadmium toxicity. There was significant (P<0.05 elevation in total leuko- leukocyte count (TLC with increase in the concen- cyte concentration of cadmium. The increase in total leukocyte count observed in this study could be attributed to a stimulation of the immune system in response to tissue damage caused by cadmium toxicity. The study has shown that the exposure of the Bufo maculatus toad to cadmium can inflict alterations in the hematologic indices, which could induce unfavorable physiological changes in the amphibian, which may lead to death. There is, therefore, the need to protect amphibians in order to sustain the biodiversity in the Nigerian Niger Delta ecological zone.

  19. Sublethal Effects of Neonicotinoid Insecticide on Calling Behavior and Pheromone Production of Tortricid Moths.

    Science.gov (United States)

    Navarro-Roldán, Miguel A; Gemeno, César

    2017-09-01

    In moths, sexual behavior combines female sex pheromone production and calling behavior. The normal functioning of these periodic events requires an intact nervous system. Neurotoxic insecticide residues in the agroecosystem could impact the normal functioning of pheromone communication through alteration of the nervous system. In this study we assess whether sublethal concentrations of the neonicotinoid insecticide thiacloprid, that competitively modulates nicotinic acetylcholine receptors at the dendrite, affect pheromone production and calling behavior in adults of three economically important tortricid moth pests; Cydia pomonella (L.), Grapholita molesta (Busck), and Lobesia botrana (Denis & Schiffermüller). Thiacloprid significantly reduced the amount of calling in C. pomonella females at LC 0.001 (a lethal concentration that kills only 1 in 10 5 individuals), and altered its calling period at LC 1 , and in both cases the effect was dose-dependent. In the other two species the effect was similar but started at higher LCs, and the effect was relatively small in L. botrana. Pheromone production was altered only in C. pomonella, with a reduction of the major compound, codlemone, and one minor component, starting at LC 10 . Since sex pheromones and neonicotinoids are used together in the management of these three species, our results could have implications regarding the interaction between these two pest control methods.

  20. Sublethal Effects of the Neonicotinoid Insecticide Thiamethoxam on the Transcriptome of the Honey Bees (Hymenoptera: Apidae).

    Science.gov (United States)

    Shi, Teng-Fei; Wang, Yu-Fei; Liu, Fang; Qi, Lei; Yu, Lin-Sheng

    2017-12-05

    Neonicotinoid insecticides are now the most widely used insecticides in the world. Previous studies have indicated that sublethal doses of neonicotinoids impair learning, memory capacity, foraging, and immunocompetence in honey bees (Apis mellifera, Linnaeus) (Hymenoptera: Apidae). Despite these, few studies have been carried out on the molecular effects of neonicotinoids. In this study, we focus on the second-generation neonicotinoid thiamethoxam, which is currently widely used in agriculture to protect crops. Using high-throughput RNA-Seq, we investigated the transcriptome profile of honey bees after subchronic exposure to 10 ppb thiamethoxam over 10 d. In total, 609 differentially expressed genes (DEGs) were identified, of which 225 were upregulated and 384 were downregulated. Several genes, including vitellogenin, CSP3, defensin-1, Mrjp1, and Cyp6as5 were selected and further validated using real-time quantitative polymerase chain reaction assays. The functions of some DEGs were identified, and Gene Ontology-enrichment analysis showed that the enriched DEGs were mainly linked to metabolism, biosynthesis, and translation. Kyoto Encyclopedia of Genes and Genomes pathway analysis showed that thiamethoxam affected biological processes including ribosomes, the oxidative phosphorylation pathway, tyrosine metabolism pathway, pentose and glucuronate interconversions, and drug metabolism. Overall, our results provide a basis for understanding the molecular mechanisms of the complex interactions between neonicotinoid insecticides and honey bees. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Sublethal Effects in Pest Management: A Surrogate Species Perspective on Fruit Fly Control

    Directory of Open Access Journals (Sweden)

    John E. Banks

    2017-07-01

    Full Text Available Tephritid fruit flies are economically important orchard pests globally. While much effort has focused on controlling individual species with a combination of pesticides and biological control, less attention has been paid to managing assemblages of species. Although several tephritid species may co-occur in orchards/cultivated areas, especially in mixed-cropping schemes, their responses to pesticides may be highly variable. Furthermore, predictive efforts about toxicant effects are generally based on acute toxicity, with little or no regard to long-term population effects. Using a simple matrix model parameterized with life history data, we quantified the responses of several tephritid species to the sublethal effects of a toxicant acting on fecundity. Using a critical threshold to determine levels of fecundity reduction below which species are driven to local extinction, we determined that threshold levels vary widely for the three tephritid species. In particular, Bactrocera dorsalis was the most robust of the three species, followed by Ceratitis capitata, and then B. cucurbitae, suggesting individual species responses should be taken into account when planning for area-wide pest control. The rank-order of susceptibility contrasts with results from several field/lab studies testing the same species, suggesting that considering a combination of life history traits and individual species susceptibility is necessary for understanding population responses of species assemblages to toxicant exposure.

  2. Assessment of Mercury Bioaccumulation in Zebra Cichlid (Cichlasoma Nigrofasciatum Exposed to Sublethal Concentrations of Permethrin

    Directory of Open Access Journals (Sweden)

    Mahdi Banaee

    2014-12-01

    Full Text Available Background: Aquatic ecosystems are frequently subjected to contamination by toxic heavy metals and pesticides, yet very little is known about the influence of pesticides on bioaccumulation of heavy metals in aquatic organisms. Mercury is a toxic metal with no known biological benefit to organisms. Bioavailability of mercury in aquatic environments depends on biological and non-biological parameters including other pollutants. Therefore, the objectives of this research were to determine the effects of permethrin on bioaccumulation of mercury in zebra cichlid. Methods: Acute toxicity (LC50 of permethrin and mercury chloride was evaluated by estimating mortality in Probit Model in SPSS (version 19.0 IBM. In sub-lethal toxicity, zebra cichlid (Cichlasoma nigrofasciatum was exposed to various concentrations of permethrin (0.0, 0.40, 0.80, 1.20 and 1.60 µg.L-1 combined with 20 µg.L-1 mercury chloride for 15 days. At the end of the experiment, mercury concentrations were measured using ICP-OES-Perkin elmer (optima 7300-DV. Results: 96 h LC50 values of permethrin and mercury for C. nigrofasciatum were calculated to be 17.55 µg.L-1 and 140.38 µg.L-1, respectively. Our results clearly showed that the bioaccumulation of mercury in the specimens increased with increasing concentrations of permethrin to 1.20 and 1.60 µg.L-1. Conclusion: Increasing the concentration of permethrin had synergistic effects on the bioaccumulation of mercury in fish.

  3. Evaluating sublethal indicators of stress in Asiatic clams (Corbicula fluminea) caged in an urban stream

    Energy Technology Data Exchange (ETDEWEB)

    Black, M.C.; Belin, J.I. [Univ. of Georgia, Athens, GA (United States). College of Agricultural and Environmental Sciences

    1998-12-31

    Freshwater bivalves have been used extensively to monitor chemical accumulation in field exposures, although little information is available on the use of biomarker measurements in field exposures with bivalves. DNA strand breakage, growth rate, condition index and percentage tissue water were measured in freshwater Asiatic clams (Corbicula fluminea) exposed in-situ in a stream that receives urban and industrial stormwater runoff and in a non-impacted reference stream. After 4 weeks exposure, DNA strand lengths in foot tissue from Trail Creek-exposed clams were significantly shorter than DNA from reference clams. These results suggest a reduction in DNA integrity in Trail Creek-exposed clams, possibly indicating exposure to genotoxic chemicals. No significant differences were observed in the growth rates of clams. However, a significant inverse relationship was detected between condition index and % tissue water for all clams. Furthermore, site-specific differences in percentage tissue water and condition indices were observed after 2 and 10 weeks exposure. For this study DNA strand breakage, condition indices, and tissue hydration appear to be more sensitive indicators of sublethal toxicity than growth.

  4. Integrated microfluidic technology for sub-lethal and behavioral marine ecotoxicity biotests

    Science.gov (United States)

    Huang, Yushi; Reyes Aldasoro, Constantino Carlos; Persoone, Guido; Wlodkowic, Donald

    2015-06-01

    Changes in behavioral traits exhibited by small aquatic invertebrates are increasingly postulated as ethically acceptable and more sensitive endpoints for detection of water-born ecotoxicity than conventional mortality assays. Despite importance of such behavioral biotests, their implementation is profoundly limited by the lack of appropriate biocompatible automation, integrated optoelectronic sensors, and the associated electronics and analysis algorithms. This work outlines development of a proof-of-concept miniaturized Lab-on-a-Chip (LOC) platform for rapid water toxicity tests based on changes in swimming patterns exhibited by Artemia franciscana (Artoxkit M™) nauplii. In contrast to conventionally performed end-point analysis based on counting numbers of dead/immobile specimens we performed a time-resolved video data analysis to dynamically assess impact of a reference toxicant on swimming pattern of A. franciscana. Our system design combined: (i) innovative microfluidic device keeping free swimming Artemia sp. nauplii under continuous microperfusion as a mean of toxin delivery; (ii) mechatronic interface for user-friendly fluidic actuation of the chip; and (iii) miniaturized video acquisition for movement analysis of test specimens. The system was capable of performing fully programmable time-lapse and video-microscopy of multiple samples for rapid ecotoxicity analysis. It enabled development of a user-friendly and inexpensive test protocol to dynamically detect sub-lethal behavioral end-points such as changes in speed of movement or distance traveled by each animal.

  5. The concerted action of lactoferrin and bacteriophages in the clearance of bacteria in sublethally infected mice.

    Science.gov (United States)

    Zimecki, Michał; Artym, Jolanta; Kocieba, Maja; Weber-Dabrowska, Beata; Lusiak-Szelachowska, Marzena; Górski, Andrzej

    2008-02-07

    Both lactoferrin (LF) and bacteriophages are potent antibacterial agents. LF is contained in the secretory fluids of mammals and bacteriophages are specific bacterial viruses. The aim of this investigation was to determine whether combined treatment of infected mice may allow lowering the therapeutic dose of specific bacteriophages for Escherichia coli and Staphylococcus aureus. CBA mice were infected intravenously (i.v.) with sublethal doses of E. coli or S. aureus and the specific T4 or A5 bacteriophages, respectively, were administered intraperitoneally (i.p.) or per os one hour following infection. The numbers of colony-forming units (CFUs) were determined in the livers after 24 hours. Comparative administration of bacteriophages i.p. or per os showed that both routes of administration were equally efficacious in the protective action of bacteriophages. The bacteriophages were still very potent in reducing CFU numbers in the liver at a dose of 10(5)/mouse. Application of bovine lactoferrin (LF), 10 mg i.v., 24 h before infection, was also very effective in reducing CFU numbers. Using suboptimal (10(3)-10(4)) doses of bacteriophages and administration of LF, a more potent protective effect in reducing the CFU numbers in the infected mice was demonstrated. The combined effect of LF and bacteriophages in reducing CFU numbers was significantly higher than the effects of either agent alone. The study demonstrated that the combined application of LF and bacteriophages can significantly lower (1000 times) the effective dose of bacteriophages in reducing CFU numbers in infected mice.

  6. Inhibition of acetylcholinesterase in guppies (Poecilia reticulata) by chlorpyrifos at sublethal concentrations: Methodological aspects

    Energy Technology Data Exchange (ETDEWEB)

    van der Wel, H.; Welling, W.

    1989-04-01

    Acetylcholinesterase activity is a potential biochemical indicator of toxic stress in fish and a sensitive parameter for testing water for the presence of organophosphates. A number of methodological aspects regarding the determination of the in vivo effect of chlorpyrifos on acetylcholinesterase in guppies have been investigated. It was found that with acetylthiocholine as a substrate, the contribution of pseudocholinesterase to the total cholinesterase activity can be neglected. Protection of acetylcholinesterase of guppies exposed to chlorpyrifos from additional, artifactual in vitro enzyme inhibition during homogenization is necessary. Very low concentrations of acetone in the exposure medium, resulting from dilution of the stock solution of chlorpyrifos in acetone, can result in large decreases in the oxygen content of this medium. This may affect the uptake rate of the toxic compound and, thereby, cholinesterase inhibition. Very low, sublethal concentrations of chlorpyrifos result in high inhibition levels of acetylcholinesterase (80-90%) in guppies within 2 weeks of continuous exposure. Recovery of the enzyme activity occurs after the exposed animals are kept in clean medium for 4 days, but the rate of recovery is considerably lower than the rate of inhibition.

  7. Sub-lethal effects of herbicides penoxsulam, imazamox, fluridone and glyphosate on Delta Smelt (Hypomesus transpacificus).

    Science.gov (United States)

    Jin, Jiali; Kurobe, Tomofumi; Ramírez-Duarte, Wilson F; Bolotaolo, Melissa B; Lam, Chelsea H; Pandey, Pramod K; Hung, Tien-Chieh; Stillway, Marie E; Zweig, Leanna; Caudill, Jeffrey; Lin, Li; Teh, Swee J

    2018-02-01

    Concerns regarding non-target toxicity of new herbicides used to control invasive aquatic weeds in the San Francisco Estuary led us to compare sub-lethal toxicity of four herbicides (penoxsulam, imazamox, fluridone, and glyphosate) on an endangered fish species Delta Smelt (Hypomesus transpacificus). We measured 17β-estradiol (E2) and glutathione (GSH) concentrations in liver, and acetylcholinesterase (AChE) activity in brain of female and male fish after 6 h of exposure to each of the four herbicides. Our results indicate that fluridone and glyphosate disrupted the E2 concentration and decreased glutathione concentration in liver, whereas penoxsulam, imazamox, and fluridone inhibited brain AChE activity. E2 concentrations were significantly increased in female and male fish exposed to 0.21 μM of fluridone and in male fish exposed to 0.46, 4.2, and 5300 μM of glyphosate. GSH concentrations decreased in males exposed to fluridone at 2.8 μM and higher, and glyphosate at 4.2 μM. AChE activity was significantly inhibited in both sexes exposed to penoxsulam, imazamox, and fluridone, and more pronounced inhibition was observed in females. The present study demonstrates the potential detrimental effects of these commonly used herbicides on Delta Smelt. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Sublethal toxicity of quinalphos on oxidative stress and antioxidant responses in a freshwater fish Cyprinus carpio.

    Science.gov (United States)

    Hemalatha, Devan; Amala, Antony; Rangasamy, Basuvannan; Nataraj, Bojan; Ramesh, Mathan

    2016-11-01

    Extensive use of quinalphos, an organophosphorus pesticide, is likely to reach the aquatic environment and thereby posing a health concern for aquatic organisms. Oxidative stress and antioxidant responses may be good indicators of pesticide contamination in aquatic organisms. The data on quinalphos induced oxidative stress and antioxidant responses in carps are scanty. This study is aimed to assess the two sublethal concentrations of quinalphos (1.09 and 2.18 μL L -1 ) on oxidative stress and antioxidant responses of Cyprinus carpio for a period of 20 days. In liver, the malondialdehyde level was found to be significantly increased in both the concentrations. The results of the antioxidant parameters obtained show a significant increase in superoxide dismutase, catalase, and glutathione-S-transferase activity in liver of fish. These results demonstrate that environmentally relevant levels of the insecticide quinalphos can cause oxidative damage and increase the antioxidant scavenging capacity in C. carpio. This may reflect the potential role of these parameters as useful biomarkers for the assessment of pesticide contamination. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1399-1406, 2016. © 2015 Wiley Periodicals, Inc.

  9. Analysis of lethal and sublethal impacts of environmental disasters on sperm whales using stochastic modeling.

    Science.gov (United States)

    Ackleh, Azmy S; Chiquet, Ross A; Ma, Baoling; Tang, Tingting; Caswell, Hal; Veprauskas, Amy; Sidorovskaia, Natalia

    2017-08-01

    Mathematical models are essential for combining data from multiple sources to quantify population endpoints. This is especially true for species, such as marine mammals, for which data on vital rates are difficult to obtain. Since the effects of an environmental disaster are not fixed, we develop time-varying (nonautonomous) matrix population models that account for the eventual recovery of the environment to the pre-disaster state. We use these models to investigate how lethal and sublethal impacts (in the form of reductions in the survival and fecundity, respectively) affect the population's recovery process. We explore two scenarios of the environmental recovery process and include the effect of demographic stochasticity. Our results provide insights into the relationship between the magnitude of the disaster, the duration of the disaster, and the probability that the population recovers to pre-disaster levels or a biologically relevant threshold level. To illustrate this modeling methodology, we provide an application to a sperm whale population. This application was motivated by the 2010 Deepwater Horizon oil rig explosion in the Gulf of Mexico that has impacted a wide variety of species populations including oysters, fish, corals, and whales.

  10. Sub-lethal cadmium exposure increases phytochelatin concentrations in the aquatic snail Lymnaea stagnalis

    Energy Technology Data Exchange (ETDEWEB)

    SF, Gonçalves [Department of Biology & CESAM, Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro (Portugal); SK, Davies [Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ (United Kingdom); Bennett, M. [Department of Life Sciences, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ (United Kingdom); Raab, A.; Feldmann, J. [TESLA, Department of Chemistry, University of Aberdeen, Meston Walk, Aberdeen AB24 3UE, Scotland (United Kingdom); Kille, P. [Cardiff School of Biosciences, Cardiff University, Park Place, Cardiff CF10 3US (United Kingdom); Loureiro, S. [Department of Biology & CESAM, Centre for Environmental and Marine Studies, University of Aveiro, 3810-193 Aveiro (Portugal); DJ, Spurgeon [Centre for Ecology and Hydrology, Maclean Building, Benson Lane, Wallingford OX10 8BB (United Kingdom); JG, Bundy, E-mail: j.bundy@imperial.ac.uk [Department of Surgery and Cancer, Imperial College London, Sir Alexander Fleming Building, London SW7 2AZ (United Kingdom)

    2016-10-15

    Phytochelatins are metal-binding metabolites found in almost all plant species and some animal groups, including nematodes and annelids, where they can play an important role in detoxifying metals such as cadmium. Species from several other taxa contain a phytochelatin synthase (PCS) gene orthologue, including molluscs, indicating they may have the potential to synthesize phytochelatins. However, the presence of a gene alone does not demonstrate that it plays a functional role in metal detoxification. In the present study, we show that the aquatic snail Lymnaea stagnalis produced both penta- and heptapeptide phytochelatins (i.e. phytochelatin-2 and phytochelatin-3), and their levels increased in response to sub-lethal levels of cadmium. - Highlights: • Little is known about the role of phytochelatins in metal detoxification in animals. • We detected phytochelatins (PC{sub 2} and PC{sub 3}) in a mollusc species, Lymnaea stagnalis. • Phytochelatins increased in Lymnaea stagnalis when exposed to cadmium. • Future research on phytochelatin responses in molluscs would be valuable.

  11. New pentose dimers with bicyclic moieties from pretreated biomass

    DEFF Research Database (Denmark)

    Rasmussen, H.; Sørensen, Henrik Rokkjær; Tanner, David Ackland

    2017-01-01

    oligophenolic compounds from pilot scale pretreated wheat straw was assessed at two different pretreatment severities. An increase in severity of the pretreatment led to more oligophenol compounds and in turn the total overall cellulase inhibition increased. When the xylooligosaccharides were enzymatically...... from either xylose or glucose reacting with glyceraldehyde during pretreatment. The data show that the main cellulase inhibition from hydrothermally pretreated wheat straw liquors is due to xylooligosaccharides followed by oligophenolic compounds and the newly discovered dipentose with bicyclic...

  12. Enhancement of anaerobic digestibility of waste activated sludge using photo-Fenton pretreatment.

    Science.gov (United States)

    Heng, Gan Chin; Isa, Mohamed Hasnain; Lim, Jun-Wei; Ho, Yeek-Chia; Zinatizadeh, Ali Akbar Lorestani

    2017-12-01

    Biological treatments, such as activated sludge process, are common methods to treat municipal and industrial wastewaters. However, they produce huge amounts of waste activated sludge (WAS). The excess sludge treatment and disposal are a challenge for wastewater treatment plants due to economic, environmental, and regulatory factors. In this study, photo-Fenton pretreatment (oxidation using hydrogen peroxide and iron catalyst aided with UV light) was optimized using response surface methodology (RSM) and central composite design (CCD) to determine the effects of three operating parameters (H2O2 dosage, H2O2/Fe2+ molar ratio, and irradiation time) on disintegration and dewaterability of WAS. MLVSS removal, capillary suction time (CST) reduction, sCOD, and EPS were obtained as 70%, 25%, 12,000 mg/L, and 500 mg/L, respectively, at the optimal conditions, i.e., 725 g H2O2/kg TS, H2O2/Fe2+ molar ratio 80, and irradiation time 40 min. Two batch-fed completely mixed mesophilic anaerobic digesters were then operated at 15-day solid retention time (SRT) and 37 ± 0.5 °C to compare the digestibility of untreated and photo-Fenton pretreated sludge in terms of volatile solids (VS) reduction, COD removal, and biogas production at steady-state operations. Photo-Fenton pretreatment followed by anaerobic digestion of WAS was very effective and yielded 75.7% total VS reduction, 81.5% COD removal, and 0.29-0.31 m3/kg VSfed·d biogas production rate, compared to 40.7% total VS solid reduction, 54.7% COD removal, and 0.12-0.17 m3/kg VSfed·d biogas production rate for control. Thus, photo-Fenton can be a useful pretreatment step in sludge management.

  13. Microwave pretreatment of switchgrass for bioethanol production

    Science.gov (United States)

    Keshwani, Deepak Radhakrishin

    Lignocellulosic materials are promising alternative feedstocks for bioethanol production. These materials include agricultural residues, cellulosic waste such as newsprint and office paper, logging residues, and herbaceous and woody crops. However, the recalcitrant nature of lignocellulosic biomass necessitates a pretreatment step to improve the yield of fermentable sugars. The overall goal of this dissertation is to expand the current state of knowledge on microwave-based pretreatment of lignocellulosic biomass. Existing research on bioenergy and value-added applications of switchgrass is reviewed in Chapter 2. Switchgrass is an herbaceous energy crop native to North America and has high biomass productivity, potentially low requirements for agricultural inputs and positive environmental impacts. Based on results from test plots, yields in excess of 20 Mg/ha have been reported. Environmental benefits associated with switchgrass include the potential for carbon sequestration, nutrient recovery from run-off, soil remediation and provision of habitats for grassland birds. Published research on pretreatment of switchgrass reported glucose yields ranging from 70-90% and xylose yields ranging from 70-100% after hydrolysis and ethanol yields ranging from 72-92% after fermentation. Other potential value-added uses of switchgrass include gasification, bio-oil production, newsprint production and fiber reinforcement in thermoplastic composites. Research on microwave-based pretreatment of switchgrass and coastal bermudagrass is presented in Chapter 3. Pretreatments were carried out by immersing the biomass in dilute chemical reagents and exposing the slurry to microwave radiation at 250 watts for residence times ranging from 5 to 20 minutes. Preliminary experiments identified alkalis as suitable chemical reagents for microwave-based pretreatment. An evaluation of different alkalis identified sodium hydroxide as the most effective alkali reagent. Under optimum pretreatment

  14. Effects of irradiation and cold storage on rooting and growth of chrysanthemum cuttings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. K.; No, S. A.; Sin, H. S.; Song, H. S. [KAERI, Taejon (Korea, Republic of); Choi, B. J. [Catholic University of Daegu, Gyeongsan (Korea, Republic of)

    2002-10-01

    This study was carried out to investigate the combined effect of cold storage with irradiation on rooting of chrysanthemum cuttings. Each cutting had three real leaves and was 6 cm in length. Groups of the cuttings were irradiated with 0 to 70 Gy of gamma-ray after cold storage, while another groups were irradiated with the same doses and then stored at 4 .deg. C for four weeks. Root and shoot growth was observed at 15 and 20 days after planting of the cuttings in a plug tray. Accelerated root formation was observed in 30 Gy irradiated group, and root growth was also enhanced in 20 and 30 Gy irradiated groups 20 days after planting. In case of irradiation combined with pre-treatment of cold storage, survival rate of cuttings was the highest (80%) in 30 Gy irradiated group. The groups treated with cold storage after irradiation were generally better in root formation, among which 50 Gy irradiated group showed the highest rate of root growth.

  15. Temperature Modelling of the Biomass Pretreatment Process

    DEFF Research Database (Denmark)

    Prunescu, Remus Mihail; Blanke, Mogens; Jensen, Jakob M.

    2012-01-01

    that captures the environmental temperature differences inside the reactor using distributed parameters. A Kalman filter is then added to account for any missing dynamics and the overall model is embedded into a temperature soft sensor. The operator of the plant will be able to observe the temperature in any......In a second generation biorefinery, the biomass pretreatment stage has an important contribution to the efficiency of the downstream processing units involved in biofuel production. Most of the pretreatment process occurs in a large pressurized thermal reactor that presents an irregular temperature...... distribution. Therefore, an accurate temperature model is critical for observing the biomass pretreatment. More than that, the biomass is also pushed with a constant horizontal speed along the reactor in order to ensure a continuous throughput. The goal of this paper is to derive a temperature model...

  16. Induction of acute brain injury in mice by irradiation with high-LET charged particles

    Science.gov (United States)

    Liu, Yang; Zhang, Hong

    The present study was performed to evaluate the induction of acute brain injury in mice after 235 Mev/u carbon ion irradiation. In our study, young outbred Kunming mice were divided into four treatment groups according to the penetration depth of carbon ions. Animals were irradiated with a sublethal dose of carbon ion beams prior to the Bragg curve. An experiment was performed to evaluate the acute alterations in histology, DNA double-strand breaks (DNA DSBs) as well as p53and Bax expression in the brain 96 h post-irradiation. The results demonstrated that various histopathological changes, a significant number of DNA DSBs and elevated p53 and Bax protein expression were induced in the brain following exposure to carbon ions. This was particularly true for mice irradiated with ions having a 9.1 cm-pentration depth, indicating that carbon ions can led to deleterious lesions in the brain of young animals within 96 h. Moreover, there was a remarkable increase in DNA DSBs and in the severity of histopathological changes as the penetration depths of ions increased, which may be associated with the complex track structure of heavy ions. These data reveal that carbon ions can promote serious neuropathological degeneration in the cerebral cortex of young mice. Given that damaged neurons cannot regenerate, these findings warrant further investigation of the adverse effects of the space radiation and the passage of a therapeutic heavy ion beam in the plateau region of the Bragg curve through healthy brain tissue.

  17. Modification of graphene oxide by laser irradiation: a new route to enhance antibacterial activity

    Science.gov (United States)

    Buccheri, Maria A.; D'Angelo, Daniele; Scalese, Silvia; Spanò, Simon F.; Filice, Simona; Fazio, Enza; Compagnini, Giuseppe; Zimbone, Massimo; Brundo, Maria V.; Pecoraro, Roberta; Alba, Anna; Sinatra, Fulvia; Rappazzo, Giancarlo; Privitera, Vittorio

    2016-06-01

    The antibacterial activity and possible toxicity of graphene oxide and laser-irradiated graphene oxide (iGO) were investigated. Antibacterial activity was tested on Escherichia coli and shown to be higher for GO irradiated for at least three hours, which seems to be correlated to the resulting morphology of laser-treated GO and independent of the kind and amount of oxygen functionalities. X-ray photoelectron spectroscopy, Raman spectroscopy, dynamic light scattering and scanning electron microscopy (SEM) show a reduction of the GO flakes size after visible laser irradiation, preserving considerable oxygen content and degree of hydrophilicity. SEM images of the bacteria after the exposure to the iGO flakes confirm membrane damage after interaction with the laser-modified morphology of GO. In addition, a fish embryo toxicity test on zebrafish displayed that neither mortality nor sublethal effects were caused by the different iGO solutions, even when the concentration was increased up to four times higher than the one effective in reducing the bacteria survival. The antibacterial properties and the absence of toxicity make the visible laser irradiation of GO a promising option for water purification applications.

  18. Extrusion pretreatment of pine wood chips.

    Science.gov (United States)

    Karunanithy, C; Muthukumarappan, K; Gibbons, W R

    2012-05-01

    Pretreatment is the first step to open up lignocellulose structure in the conversion of biomass to biofuels. Extrusion can be a viable pretreatment method due to its ability to simultaneously expose biomass to a range of disruptive conditions in a continuous flow process. Extruder screw speed, barrel temperature, and feedstock moisture content are important factors that can influence sugar recovery from biomass. Hence, the current study was undertaken to investigate the effects of these parameters on extrusion pretreatment of pine wood chips. Pine wood chip at 25, 35, and 45 % wb moisture content were pretreated at various barrel temperatures (100, 140, and 180 °C) and screw speeds (100, 150, and 200 rpm) using a screw with compression ratios of 3:1. The pretreated pine wood chips were subjected to standard enzymatic hydrolysis followed by sugar and byproducts quantification. Statistical analyses revealed the existence of significant differences in sugar recovery due to independent variables based on comparing the mean of main effects and interaction effects. Pine wood chips pretreated at a screw speed of 150 rpm and a barrel temperature of 180 °C with a moisture content of 25 % resulted in a maximum cellulose, hemicellulose, and total sugar recoveries of 65.8, 65.6, and 66.1 %, respectively, which was about 6.7, 7.9, and 6.8 fold higher than the control (unpretreated pine chips). Furthermore, potential fermentation inhibitors such as furfural, hydroxyl methyl furfural, and acetic acid were not found in any of the treatment combinations.

  19. Behavioral, Morphological, and Gene Expression Changes Induced by 60Co-γ Ray Irradiation in Bactrocera tau (Walker

    Directory of Open Access Journals (Sweden)

    Jun Cai

    2018-02-01

    Full Text Available The sterile insect technique (SIT may reduce pest populations by allowing sufficient amount of irradiation-induced sterile males to mate with wild females whilst maintaining mating ability comparable to wild males. Although the SIT methods are well understood, the optimal sterilizing dose and processing development stage for application vary among species. To ensure effective pest control programs, effects of irradiation on physiology, behavior, and gene function in the target species should be defined, however, little is known about irradiation effects in Bactrocera tau. Here, the effects of irradiation on rates of fecundity, egg hatch, eclosion, mating competitiveness, flight capability, morphology of reproductive organs, and yolk protein (YP gene expression were studied. The results showed that rates of female fecundity and egg hatch decreased significantly (51 ± 19 to 0.06 ± 0.06 and 98.90 ± 1.01 to 0, respectively when pupae were treated with >150 Gy irradiation. Flight capability and mating competitiveness were not significantly influenced at doses <250 Gy. Ovaries and fallopian tubes became smaller after irradiation, but there was no change in testes size. Finally, we found that expression of the YP gene was up-regulated by irradiation at 30 and 45 days post-emergence, but the mechanisms were unclear. Our study provides information on the determination of the optimal irradiation sterilizing dose in B. tau, and the effects of irradiation on physiology, morphology and gene expression that will facilitate an understanding of sub-lethal impacts of the SIT and expand its use to the control of other species.

  20. Comparative proteomic analysis of Listeria monocytogenes ATCC 7644 exposed to a sublethal concentration of nisin.

    Science.gov (United States)

    Miyamoto, Kendi Nishino; Monteiro, Karina Mariante; da Silva Caumo, Karin; Lorenzatto, Karina Rodrigues; Ferreira, Henrique Bunselmeyer; Brandelli, Adriano

    2015-04-24

    Listeria monocytogenes infections have been frequently reported in many food poisoning outbreaks around the world. In this work, the protein repertoires of L. monocytogenes ATCC 7644 cells treated or not with a 10(-3)mg/mL nisin sublethal concentration, established by antimicrobial susceptibility tests, were analyzed by LC-MS/MS. Overall, 179 proteins were identified, 9 of them more abundant in nisin-treated samples, and 4 more abundant in non-treated control samples. In nisin treated cells, proteins associated to oxidative stress response showed higher abundance. Also, the higher abundance of an enzyme related to the production of cell membrane lipids upon nisin exposure is suggestive of both a failure in conventional cell division mechanism and the activation of an alternative L-form mediated division mechanism. Finally, flagellar and motility proteins' overexpression upon nisin exposure is indicative of increased bacterial motility in response to the bacteriocin. Taken together, these results provide new insights on nisin effects on L. monocytogenes cells and on how this bacterium may overcome a bacteriocin-containing environment. The antimicrobial mechanism of nisin on target bacterial cells has been extensively studied since discovery of this bacteriocin. The nisin pore-forming mechanism is mediated by its binding to the pyrophosphate portion of membrane lipid II [1], but some evidences point out to alternative mechanisms. Results from assays with mutacin 1140 hybrids [2] showed that the portion of nisin that is not involved with lipid II binding could damage the bacterial cell, independently of pore formation [3,4]. Moreover, there are insufficient data to explain how nisin affects the bacterial survival. In this scenario, proteomics is an interesting approach, as a comparison between treated and untreated cells may provide insights of both antimicrobial mechanisms of action and bacterial response mechanisms [5]. Copyright © 2015 Elsevier B.V. All rights

  1. Sub-lethal levels of electric current elicit the biosynthesis of plant secondary metabolites.

    Science.gov (United States)

    Kaimoyo, Evans; Farag, Mohamed A; Sumner, Lloyd W; Wasmann, Catherine; Cuello, Joel L; VanEtten, Hans

    2008-01-01

    Many secondary metabolites that are normally undetectable or in low amounts in healthy plant tissue are synthesized in high amounts in response to microbial infection. Various abiotic and biotic agents have been shown to mimic microorganisms and act as elicitors of the synthesis of these plant compounds. In the present study, sub-lethal levels of electric current are shown to elicit the biosynthesis of secondary metabolites in transgenic and non-transgenic plant tissue. The production of the phytoalexin (+)-pisatin by pea was used as the main model system. Non-transgenic pea hairy roots treated with 30-100 mA of electric current produced 13 times higher amounts of (+)-pisatin than did the non-elicited controls. Electrically elicited transgenic pea hairy root cultures blocked at various enzymatic steps in the (+)-pisatin biosynthetic pathway also accumulated intermediates preceding the blocked enzymatic step. Secondary metabolites not usually produced by pea accumulated in some of the transgenic root cultures after electric elicitation due to the diversion of the intermediates into new pathways. The amount of pisatin in the medium bathing the roots of electro-elicited roots of hydroponically cultivated pea plants was 10 times higher 24 h after elicitation than in the medium surrounding the roots of non-elicited control plants, showing not only that the electric current elicited (+)-pisatin biosynthesis but also that the (+)-pisatin was released from the roots. Seedlings, intact roots or cell suspension cultures of fenugreek (Trigonella foenum-graecum), barrel medic, (Medicago truncatula), Arabidopsis thaliana, red clover (Trifolium pratense) and chickpea (Cicer arietinum) also produced increased levels of secondary metabolites in response to electro-elicitation. On the basis of our results, electric current would appear to be a general elicitor of plant secondary metabolites and to have potential for application in both basic and commercial research.

  2. Responses of bay anchovy (Anchoa mitchilli) larvae under lethal and sublethal scenarios of crude oil exposure.

    Science.gov (United States)

    Duffy, Tara A; Childress, William; Portier, Ralph; Chesney, Edward J

    2016-12-01

    Bay anchovy (Anchoa mitchilli) is an ecologically important zooplanktivorous fish inhabiting estuaries of the Gulf of Mexico and eastern North America from Maine to Florida. Because they have a protracted spawning season (spring through fall) and are abundant at all life stages in coastal estuaries, their eggs and larvae likely encountered oil that reached the coast during the Deepwater Horizon oil spill. We compared responses to oil exposure at different life stages and at lethal and sublethal conditions using acute, 24h exposures. In a series of experiments, bay anchovy larvae were exposed to high energy water accommodated fractions (HEWAF) and chemically-enhanced WAF (CEWAF) at two stages of larval development (5 and 21 days post hatch, dph). HEWAF oil exposures induced significantly greater life stage dependent sensitivity at 5 dph than at 21 dph but chemically dispersed (CEWAF) exposure mortality was more variable and LC50s were not significantly different between 5 and 21dph larvae. Acute exposure to two low-level concentrations of CEWAF did not result in significant mortality over 24h, but resulted in a 25-77% reduction in larval survival and a 12-34% reduction in weight specific growth after six days of post-exposure growth following the initial 24h exposure. These results show that younger (5 dph) bay anchovy larvae are more vulnerable to acute oil exposure than older (21 dph) larvae, and that acute responses do not accurately reflect potential population level mortality and impacts to growth and development. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Sublethal concentrations of silver nanoparticles affect the mechanical stability of biofilms.

    Science.gov (United States)

    Grün, Alexandra Y; Meier, Jutta; Metreveli, George; Schaumann, Gabriele E; Manz, Werner

    2016-12-01

    Bacterial biofilms are most likely confronted with silver nanoparticles (Ag NPs) as a pollutant stressor in aquatic systems. In this study, biofilms of Aquabacterium citratiphilum were exposed for 20 h to 30 and 70 nm citrate stabilized Ag NPs in low-dose concentrations ranging from 600 to 2400 μg l(-1), and the Ag NP-mediated effects on descriptive, structural, and functional biofilm characteristics, including viability, protein content, architecture, and mechanical stability, were investigated. Viability, based on the bacterial cell membrane integrity of A. citratiphilum, as determined by epifluorescence microscopy, remained unaffected after Ag NP exposure. Moreover, in contrast to information in the current literature, protein contents of cells and extracellular polymeric substances (EPS) and biofilm architecture, including dry mass, thickness, and density, were not significantly impacted by exposure to Ag NPs. However, the biofilms themselves served as effective sinks for Ag NPs, exhibiting enrichment factors from 5 to 8. Biofilms showed a greater capacity to accumulate 30 nm sized Ag NPs than 70 nm Ag NPs. Furthermore, Ag NPs significantly threatened the mechanical stability of biofilms, as determined by a newly developed assay. For 30 nm Ag NPs, the mechanical stability of biofilms decreased as the Ag NP concentrations applied to them increased. In contrast, 70 nm Ag NPs produced a similar decrease in mechanical stability for each applied concentration. Overall, this finding demonstrates that exposure to Ag NPs triggers remarkable changes in biofilm adhesion and/or cohesiveness. Because of biofilm-mediated ecological services, this response raises environmental concerns regarding Ag NP release into freshwater systems, even in sublethal concentrations.

  4. Intramuscular Cobinamide Sulfite in a Rabbit Model of Sub-Lethal Cyanide Toxicity

    Science.gov (United States)

    Brenner, Matthew; Kim, Jae G.; Mahon, Sari B.; Lee, Jangwoen; Kreuter, Kelly A.; Blackledge, William; Mukai, David; Patterson, Steve; Mohammad, Othman; Sharma, Vijay S.; Boss, Gerry R.

    2009-01-01

    Objective To determine the ability of an intramuscular cobinamide sulfite injection to rapidly reverse the physiologic effects of cyanide toxicity. Background Exposure to cyanide in fires and industrial exposures and intentional cyanide poisoning by terrorists leading to mass casualties is an ongoing threat. Current treatments for cyanide poisoning must be administered intravenously, and no rapid treatment methods are available for mass casualty cyanide exposures. Cobinamide is a cobalamin (vitamin B12) analog with an extraordinarily high affinity for cyanide that is more water-soluble than cobalamin. We investigated the use of intramuscular cobinamide sulfite to reverse cyanide toxicity induced physiologic changes in a sublethal cyanide exposure animal model. Methods New Zealand white rabbits were given 10 mg sodium cyanide intravenously over 60 minutes. Quantitative diffuse optical spectroscopy and continuous wave near infrared spectroscopy monitoring of tissue oxy- and deoxyhemoglobin concentrations were performed concurrently with blood cyanide level measurements and cobinamide levels. Immediately after completion of the cyanide infusion, the rabbits were injected intramuscularly with cobinamide sulfite (n=6) or inactive vehicle (controls, n=5). Results Intramuscular administration led to rapid mobilization of cobinamide and was extremely effective at reversing the physiologic effects of cyanide on oxyhemoglobin and deoxyhemoglobin extraction. Recovery time to 63% of their baseline values in the central nervous system was in a mean of 1032 minutes in the control group and 9 minutes in the cobinamide group with a difference of 1023 minutes (95% confidence interval [CI] 116, 1874 minutes). In muscle tissue, recovery times were 76 and 24 minutes with a difference of 52 minutes (95% CI 7, 98min). Red blood cell cyanide levels returned towards normal significantly faster in cobinamide sulfite-treated animals than in control animals. Conclusions Intramuscular

  5. Lethal and Sublethal Effects of Insecticides Used on Citrus, on the Ectoparasitoid Tamarixia radiata.

    Science.gov (United States)

    Beloti, Vitor Hugo; Alves, Gustavo Rodrigues; Araújo, Diogo Feliciano Dias; Picoli, Mateus Manara; Moral, Rafael de Andrade; Demétrio, Clarice Garcia Borges; Yamamoto, Pedro Takao

    2015-01-01

    Huanglongbing (HLB) is a disease associated with the bacteria "Candidatus Liberibacter spp." and has been devastating citrus orchards around the world. Its management involves control of the insect vector, the Asian citrus psyllid Diaphorina citri Kuwayama. However, the indiscriminate use of chemicals has caused pest outbreaks and eliminated the natural enemies of the vector, such as the parasitoid Tamarixia radiata (Waterston), the main agent for biological control of D. citri. This study assessed the lethal and sublethal effects of insecticides recommended for integrated production of citrus on the parasitoid T. radiata. When adult parasitoids were exposed to residues of 25 insecticides, 20% of them, i.e., gamma-cyhalothrin, etofenprox, azadirachtin, tebufenozide and pyriproxyfen, were considered as harmless (Class 1), 12% as slightly harmful (Class 2), 12% as moderately harmful (Class 3) and 56% as harmful (Class 4), according to the classification proposed by the IOBC/WPRS. Afterward, 14 insecticides (5 harmless and 9 harmful) were sprayed on the parasitoid pupae. Of the 14 insecticides tested, only the organophosphates dimethoate and chlorpyrifos affected the parasitoid emergence. The effects of insecticides on the parasitism capacity of adults exposed to residues of azadirachtin, etofenprox, gamma-cyhalothrin, pyriproxyfen and tebufenozide (harmless) were also evaluated. Tebufenozide and gamma-cyhalothrin affected the parasitism of the F0 generation, but did not affect the emergence of the F1 and F2 generations. Therefore, for an effective IPM program, selective insecticides or harmful pesticides to adult parasitoids could be used in the field, provided that the adults do not occur naturally and the chemical applications do not coincide with parasitoid releases.

  6. Metalloporphyrin Co(III)TMPyP ameliorates acute, sublethal cyanide toxicity in mice.

    Science.gov (United States)

    Benz, Oscar S; Yuan, Quan; Amoscato, Andrew A; Pearce, Linda L; Peterson, Jim

    2012-12-17

    The formation of Co(III)TMPyP(CN)(2) at pH 7.4 has been shown to be completely cooperative (α(H) = 2) with an association constant of 2.1 (±0.2) × 10(11). The kinetics were investigated by stopped-flow spectrophotometry and revealed a complicated net reaction exhibiting 4 phases at pH 7.4 under conditions where cyanide was in excess. The data suggest molecular HCN (rather than CN(-)) to be the attacking nucleophile around neutrality. The two slower phases do not seem to be present when cyanide is not in excess, and the other two phases have rates comparable to that observed for cobalamin, a known effective cyanide scavenger. Addition of bovine serum albumin (BSA) did not affect the cooperativity of cyanide binding to Co(III)TMPyP, only lowered the equilibrium constant slightly to 1.2 (±0.2) × 10(11) and had an insignificant effect on the observed rate. A sublethal mouse model was used to assess the effectiveness of Co(III)TMPyP as a potential cyanide antidote. The administration of Co(III)TMPyP to sodium cyanide intoxicated mice resulted in the time required for the surviving mice to right themselves from a supine position being significantly decreased (9 ± 2 min) compared to that of the controls (33 ± 2 min). All observations were consistent with the demonstrated antidotal activity of Co(III)TMPyP operating through a cyanide-binding (i.e., scavenging) mechanism.

  7. Sublethal effects of insecticide seed treatments on two nearctic lady beetles (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Moscardini, Valéria Fonseca; Gontijo, Pablo Costa; Michaud, J P; Carvalho, Geraldo Andrade

    2015-07-01

    Predatory insects often feed on plants or use plant products to supplement their diet, creating a potential route of exposure to systemic insecticides used as seed treatments. This study examined whether chlorantraniliprole or thiamethoxam might negatively impact Coleomegilla maculata and Hippodamia convergens when the beetles consumed the extrafloral nectar of sunflowers grown from treated seed. We reared both species on eggs of Ephestia kuehniella and then switched adult H. convergens to a diet of greenbugs, Schizaphis graminum, in order to induce oviposition in this species. Excised sunflower stems, either treated or control and refreshed every 48 h, were provided throughout larval development, or for the first week of adult life. Exposure of C. maculata larvae to chlorantraniliprole and thiamethoxam applied as seed treatments delayed adult emergence by prolonging the pupal period. When adults were exposed, thiamethoxam reduced the preoviposition period compared to chlorantraniliprole, whereas the latter treatment cause females to produce fewer clutches during the observation period. Larvae of C. maculata did not appear to obtain sufficient hydration from the sunflower stems and their subsequent fecundity and fertility were compromised in comparison to the adult exposure experiment where larvae received supplemental water during development. Exposure of H. convergens larvae to thiamethoxam skewed the sex ratio in favor of females; both materials reduced the egg viability of resulting adults and increased the period required for eclosion. Exposure of H. convergens adults to chlorantraniliprole reduced egg eclosion times compared to thiamethoxam and exposure to both insecticides reduced pupation times in progeny. The results indicate that both insecticides have negative, sublethal impacts on the biology of these predators when they feed on extrafloral nectar of sunflower plants grown from treated seed.

  8. Lethal and Sublethal Effects of Insecticides Used on Citrus, on the Ectoparasitoid Tamarixia radiata.

    Directory of Open Access Journals (Sweden)

    Vitor Hugo Beloti

    Full Text Available Huanglongbing (HLB is a disease associated with the bacteria "Candidatus Liberibacter spp." and has been devastating citrus orchards around the world. Its management involves control of the insect vector, the Asian citrus psyllid Diaphorina citri Kuwayama. However, the indiscriminate use of chemicals has caused pest outbreaks and eliminated the natural enemies of the vector, such as the parasitoid Tamarixia radiata (Waterston, the main agent for biological control of D. citri. This study assessed the lethal and sublethal effects of insecticides recommended for integrated production of citrus on the parasitoid T. radiata. When adult parasitoids were exposed to residues of 25 insecticides, 20% of them, i.e., gamma-cyhalothrin, etofenprox, azadirachtin, tebufenozide and pyriproxyfen, were considered as harmless (Class 1, 12% as slightly harmful (Class 2, 12% as moderately harmful (Class 3 and 56% as harmful (Class 4, according to the classification proposed by the IOBC/WPRS. Afterward, 14 insecticides (5 harmless and 9 harmful were sprayed on the parasitoid pupae. Of the 14 insecticides tested, only the organophosphates dimethoate and chlorpyrifos affected the parasitoid emergence. The effects of insecticides on the parasitism capacity of adults exposed to residues of azadirachtin, etofenprox, gamma-cyhalothrin, pyriproxyfen and tebufenozide (harmless were also evaluated. Tebufenozide and gamma-cyhalothrin affected the parasitism of the F0 generation, but did not affect the emergence of the F1 and F2 generations. Therefore, for an effective IPM program, selective insecticides or harmful pesticides to adult parasitoids could be used in the field, provided that the adults do not occur naturally and the chemical applications do not coincide with parasitoid releases.

  9. The Birmingham Irradiation Facility

    CERN Document Server

    Dervan, P; Hodgson, P; Marin-Reyes, H; Wilson, J

    2013-01-01

    At the end of 2012 the proton irradiation facility at the CERN PS [1] will shut down for two years. With this in mind, we have been developing a new ATLAS scanning facility at the University of Birmingham Medical Physics cyclotron. With proton beams of energy approximately 30 MeV, fluences corresponding to those of the upgraded Large Hadron Collider (HL-LHC) can be reached conveniently. The facility can be used to irradiate silicon sensors, optical components and mechanical structures (e.g. carbon fibre sandwiches) for the LHC upgrade programme. Irradiations of silicon sensors can be carried out in a temperature controlled cold box that can be scanned through the beam. The facility is described in detail along with the first tests carried out with mini (1 x 1 cm^2 ) silicon sensors.

  10. Pretreatment on Corn Stover with Low Concentration of Formic Acid

    DEFF Research Database (Denmark)

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2009-01-01

    the cellulose easily degraded into sugars and further fermented to ethanol. In this work, hydrothermal pretreatment on corn stover at 195 degrees for 15 min with and without lower concentration of formic acid was compared in terms of sugar recoveries and ethanol fermentation. For pretreatment with formic acid...... pretreatment without formic acid. Toxicity tests of liquor parts showed that there were no inhibitions found for both pretreatment conditions. After simultaneous saccharification and fermentation (SSF) of the pretreated corn stover with Baker's yeast, the highest ethanol yield of 76.5% of the theoretical...... was observed from corn stover pretreated at 195 degrees for 15min with formic acid....

  11. Fuel or irradiation subassembly

    Science.gov (United States)

    Seim, O.S.; Hutter, E.

    1975-12-23

    A subassembly for use in a nuclear reactor is described which incorporates a loose bundle of fuel or irradiation pins enclosed within an inner tube which in turn is enclosed within an outer coolant tube and includes a locking comb consisting of a head extending through one side of the inner sleeve and a plurality of teeth which extend through the other side of the inner sleeve while engaging annular undercut portions in the bottom portion of the fuel or irradiation pins to prevent movement of the pins.

  12. Curcumin Mitigates Accelerated Aging after Irradiation in Drosophila by Reducing Oxidative Stress

    Directory of Open Access Journals (Sweden)

    Ki Moon Seong

    2015-01-01

    Full Text Available Curcumin, belonging to a class of natural phenol compounds, has been extensively studied due to its antioxidative, anticancer, anti-inflammatory, and antineurodegenerative effects. Recently, it has been shown to exert dual activities after irradiation, radioprotection, and radiosensitization. Here, we investigated the protective effect of curcumin against radiation damage using D. melanogaster. Pretreatment with curcumin (100 μM recovered the shortened lifespan caused by irradiation and increased eclosion rate. Flies subjected to high-dose irradiation showed a mutant phenotype of outstretched wings, whereas curcumin pretreatment reduced incidence of the mutant phenotype. Protein carbonylation and formation of γH2Ax foci both increased following high-dose irradiation most likely due to generation of reactive oxygen species. Curcumin pretreatment reduced the amount of protein carbonylation as well as formation of γH2Ax foci. Therefore, we suggest that curcumin acts as an oxidative stress reducer as well as an effective protective agent against radiation damage.

  13. Pb2+ Biosorption by Pretreated Fungal Biomass

    OpenAIRE

    Çabuk,Ahmet; İLHAN, Semra; FİLİK, Cansu; ÇALIŞKAN, Figen

    2005-01-01

    The effect of pretreatment on the Pb2+ biosorption capacity of fungal biomasses, Aspergillus versicolor, Metarrhizium anisopliae var. anisopliae, and Penicillium verrucosum, was investigated. For this purpose, the biomasses were subjected to physical treatments such as heat and autoclaving, and chemical treatments such as sodium hydroxide, formaldehyde, gluteraldehyde, acetic acid, hydrogen peroxide, commercial laundry detergent, orthophosphoric acid and dimethyl sulfoxide. Dimethyl sulfoxid...

  14. Fermentation of pretreated corncob hemicellulose hydrolysate to ...

    African Journals Online (AJOL)

    To investigate the effect of unknown fermentation inhibitors in corncob hemicellulose acid hydrolysate processed by pretreatment and detoxification on fermentation, corncob hemicellulose acid hydrolysate and artificially prepared hydrolysate were fermented in parallel by Candida shehatae YHFK-2. The results show that ...

  15. Dissolved organic nitrogen measurement using dialysis pretreatment.

    Science.gov (United States)

    Lee, Wontae; Westerhoff, Paul

    2005-02-01

    Dissolved organic nitrogen (DON) is important for ecological and engineering researches. Quantification of low DON concentrations in waters with elevated dissolved inorganic nitrogen (DIN) using existing methods is inaccurate. In this study, a dialysis-based pretreatment technique was optimized and adopted to reduce the interference from DIN to the quantification of DON in natural water. A cellulose ester dialysis tube (nominal molecular weight cutoff = 100 Da) was used in batch and continuous-flow dialysis steps with model compounds, natural organic matter isolates, and bulk waters to develop a dialysis pretreatment approach that selectively reduces DIN from solutions containing DON. By reducing DIN concentrations, propagation of analytical variance in total dissolved nitrogen (TDN) and DIN species concentrations allows more accurate determination of DON (DON = TDN - NO3 - NO2- - NH3/NH4+). Dialysis for 24 h against continuously flowing distilled water reduced DIN species by 70%. With dialysis pretreatment, DON recoveries of more than 95% were obtained for surface water and finished drinking water, but wastewater experienced a slight loss (approximately 10%) of DON possibly due to the adsorption of organics onto the dialysis membrane, permeation of low molecular weight fractions, or biodegradation. Dialysis experiments using surface water spiked with different DIN/TDN ratios concluded that dialysis pretreatment leads to more accurate DON determination than no dialysis when DIN/TDN ratios exceed 0.6 mg of N/mg of N.

  16. Fipronil promotes motor and behavioral changes in honey bees (Apis mellifera) and affects the development of colonies exposed to sublethal doses.

    Science.gov (United States)

    Zaluski, Rodrigo; Kadri, Samir Moura; Alonso, Diego Peres; Martins Ribolla, Paulo Eduardo; de Oliveira Orsi, Ricardo

    2015-05-01

    Bees play a crucial role in pollination and generate honey and other hive products; therefore, their worldwide decline is cause for concern. New broad-spectrum systemic insecticides such as fipronil can harm bees and their use has been discussed as a potential threat to bees' survival. In the present study, the authors evaluate the in vitro toxicity of fipronil and note behavioral and motor activity changes in Africanized adult Apis mellifera that ingest or come into contact with lethal or sublethal doses of fipronil. The effects of sublethal doses on brood viability, population growth, behavior, and the expression of the defensin 1 gene in adult bees were studied in colonies fed with contaminated sugar syrup (8 µg fipronil L(-1) ). Fipronil is highly toxic to bees triggering agitation, seizures, tremors, and paralysis. Bees that are exposed to a lethal or sublethal doses showed reduced motor activity. The number of eggs that hatched, the area occupied by worker eggs, and the number of larvae and pupae that developed were reduced, adult bees showed lethargy, and colonies were abandoned when they were exposed to sublethal doses of fipronil. No change was seen in the bees' expression of defensin 1. The authors conclude that fipronil is highly toxic to honey bees and even sublethal doses may negatively affect the development and maintenance of colonies. © 2015 SETAC.

  17. Assessment of the lethal and sublethal effects of 20 environmental chemicals in zebrafish embryos and larvae by using OECD TG 212.

    Science.gov (United States)

    Horie, Yoshifumi; Yamagishi, Takahiro; Takahashi, Hiroko; Shintaku, Youko; Iguchi, Taisen; Tatarazako, Norihisa

    2017-10-01

    Fish embryo toxicity tests are used to assess the lethal and sublethal effects of environmental chemicals in aquatic organisms. Previously, we used a short-term toxicity test published by the Organization for Economic Co-operation and Development (test no. 212: Fish, Short-term Toxicity Test on Embryo and Sac-Fry Stages [OECD TG 212]) to assess the lethal and sublethal effects of aniline and several chlorinated anilines in zebrafish embryos and larvae. To expand upon this previous study, we used OECD TG 212 in zebrafish embryos and larvae to assess the lethal and sublethal effects of 20 additional environmental chemicals that included active pharmaceutical ingredients, pesticides, metals, aromatic compounds or chlorinated anilines. Zebrafish embryos (Danio rerio) were exposed to the test chemicals until 8 days post-fertilization. A delayed lethal effect was induced by 16 of the 20 test chemicals, and a positive correlation was found between heart rate turbulence and mortality. We also found that exposure to the test chemicals at concentrations lower than the lethal concentration induced the sublethal effects of edema, body curvature and absence of swim-bladder inflation. In conclusion, the environmental chemicals assessed in the present study induced both lethal and sublethal effects in zebrafish embryos and larvae, as assessed by using OECD TG 212. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  18. The change of transforming growth factor {beta} 1 (TGF- {beta} 1) expression by melatonin in irradiated lung

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Seong Soon; Choi, Ihl Bohng [College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2005-09-15

    The changed expressions of TGF- {beta} 1, as a key cytokine in the fibrotic process, due to melatonin with potent antioxidative effects, were investigated in the irradiated lung using fibrosis-sensitive C57BL/6 mice. Female C57BL/6 mice were divided into control irradiation-only, and melatonin (300 mg/kg i.p. 1 hr before irradiation) pretreatment groups. The thoraces of the mice were irradiated with a single dose of 12 Gy. The mRNA expressions of TGF-{beta} 1 in the lung tissue 2 and 4 weeks after irradiation were quantified using semiquantitive RT-PCR, and the cellular origin and expression levels of TGF- {beta} 1 protein were identified using immunohistochemical staining. The relative mRNA expression levels in the irradiation-only and melatonin pretreatment group 2 and 4 weeks after irradiation were 1.92- and 1.80-fold ({rho} = 0.064) and 2.38- and 1.94-fold ({rho} = 0.004) increased, respectively compared to those in the control group. Increased expressions of TGF- {beta} 1 protein were prominently detected in regions of histopathological radiation injury, with alveolar macrophages and septal epithelial cells serving as important sources of TGF- {beta} 1 expression. At 2 and 4 weeks after irradiation, the expression levels of protein were 15.8% vs. 16.9% ({rho} = 0.565) and 36.1% vs. 25.7% ({rho} = 0.009), respectively. The mRNA and protein expressions of TGF- {beta} 1 in the lung tissue following thoracic irradiation with 12 Gy were significantly decreased by melatonin pretreatment at 4 weeks. These results indicate that melatonin may have a possible application as an antifibrotic agent in radiation-induced lung injury.

  19. Lethal and Sublethal Effects of Essential Oils From Artemisia khorassanica and Vitex pseudo-negundo Against Plodia interpunctella (Lepidoptera: Pyralidae).

    Science.gov (United States)

    Borzoui, Ehsan; Naseri, Bahram; Abedi, Zahra; Karimi-Pormehr, Mohammad Sadegh

    2016-10-01

    Plodia interpunctella (Hübner, 1813) is a polyphagous and key pest of different stored products worldwide. The lethal and sublethal effects of essential oils of Artemisia khorassanica Podl. and Vitex pseudo-negundo (Hausskn) were studied on P. interpunctella The chemical constituents of the essential oils were also assessed using gas chromatography-mass spectrometry. Assays showed that the fumigant toxicity of A. khorassanica (LC50: 9.60 µl/liter air) was higher than V. pseudo-negundo (LC50: 23.05 µl/liter air). Moreover, the speed of mortality caused by A. khorassanica oil (LT50: 2.07 h) was higher than V. pseudo-negundo (LT50: 3.11 h). To assess the sublethal effects of the essential oils, adult moths were exposed to the LC30 of each essential oil, and life table parameters and energy contents of the surviving P. interpunctella were studied. Exposure to sublethal concentration of A. khorassanica negatively affected the life table of P. interpunctella, and also the protein, lipid, and glycogen contents of the larvae that came from treated adults. Vitex pseudo-negundo also affected lipid, protein, and glycogen contents of P. interpunctella The intrinsic rate of increase (rm), finite rate of increase ([Formula: see text]), and doubling time (DT) were not significantly different between control and V. pseudo-negundo treatment. According with these results, both tested essential oils, especially one extracted from A. khorassanica, have potential applications for the integrated management of P. interpunctella. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Lethal and sublethal toxicity of the industrial chemical epichlorohydrin on Rhinella arenarum (Anura, Bufonidae) embryos and larvae.

    Science.gov (United States)

    Hutler Wolkowicz, Ianina R; Aronzon, Carolina M; Pérez Coll, Cristina S

    2013-12-15

    Lethal and sublethal toxicity of the major chemical used in epoxide compounds, epichlorohydrin (ECH) was evaluated on the early life cycle of the common South American toad, Rhinella arenarum (Anura, Bufonidae). The stages evaluated were (according to Del Conte and Sirlin): early blastula (S.3-S.4), gastrula (S.10-S.12), rotation (S.15), tail bud (S.17), muscular response (S.18), gill circulation (S.20), open mouth (S.21), opercular folds (S.23) and complete operculum (S.25). The LC50 and EC50 values for lethal and sublethal effects were calculated. The early blastula was the most sensitive stage to ECH both for continuously and pulse-exposures (LC50-24h=50.9 mg L(-1)), while S.20 was the most resistant (LC50-24h=104.9 mg L(-1)). Among sublethal effects, early blastula was also the most sensitive stage (LOEC-48 h=20 mg L(-1)) and it has a Teratogenic Index of 2.5, which indicates the teratogenic potential of the substance. The main abnormalities were persistent yolk plugs, cell dissociation, tumors, hydropsy, oral malformations, axial/tail flexures, delayed development and reduced body size. ECH also caused neurotoxicity including scarce response to stimuli, reduction in the food intake, general weakness, spasms and shortening, erratic or circular swimming. Industrial contamination is considered an important factor on the decline of amphibian populations. Considering the available information about ECH's toxicity and its potential hazard to the environment, this work shows the first results of its developmental toxicity on a native amphibian species, Rhinella arenarum. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Exposure to Sublethal Doses of Fipronil and Thiacloprid Highly Increases Mortality of Honeybees Previously Infected by Nosema ceranae

    Science.gov (United States)

    Vidau, Cyril; Diogon, Marie; Aufauvre, Julie; Fontbonne, Régis; Viguès, Bernard; Brunet, Jean-Luc; Texier, Catherine; Biron, David G.; Blot, Nicolas; El Alaoui, Hicham; Belzunces, Luc P.; Delbac, Frédéric

    2011-01-01

    Background The honeybee, Apis mellifera, is undergoing a worldwide decline whose origin is still in debate. Studies performed for twenty years suggest that this decline may involve both infectious diseases and exposure to pesticides. Joint action of pathogens and chemicals are known to threaten several organisms but the combined effects of these stressors were poorly investigated in honeybees. Our study was designed to explore the effect of Nosema ceranae infection on honeybee sensitivity to sublethal doses of the insecticides fipronil and thiacloprid. Methodology/Finding Five days after their emergence, honeybees were divided in 6 experimental groups: (i) uninfected controls, (ii) infected with N. ceranae, (iii) uninfected and exposed to fipronil, (iv) uninfected and exposed to thiacloprid, (v) infected with N. ceranae and exposed 10 days post-infection (p.i.) to fipronil, and (vi) infected with N. ceranae and exposed 10 days p.i. to thiacloprid. Honeybee mortality and insecticide consumption were analyzed daily and the intestinal spore content was evaluated 20 days after infection. A significant increase in honeybee mortality was observed when N. ceranae-infected honeybees were exposed to sublethal doses of insecticides. Surprisingly, exposures to fipronil and thiacloprid had opposite effects on microsporidian spore production. Analysis of the honeybee detoxification system 10 days p.i. showed that N. ceranae infection induced an increase in glutathione-S-transferase activity in midgut and fat body but not in 7-ethoxycoumarin-O-deethylase activity. Conclusions/Significance After exposure to sublethal doses of fipronil or thiacloprid a higher mortality was observed in N. ceranae-infected honeybees than in uninfected ones. The synergistic effect of N. ceranae and insecticide on honeybee mortality, however, did not appear strongly linked to a decrease of the insect detoxification system. These data support the hypothesis that the combination of the increasing

  2. Sublethal Exposure to Diatomaceous Earth Increases Net Fecundity of Flour Beetles (Tribolium confusum) by Inhibiting Egg Cannibalism

    Science.gov (United States)

    Shostak, Allen W.

    2014-01-01

    Population regulation results from an interplay of numerous intrinsic and external factors, and for many insects cannibalism is such a factor. This study confirms a previously-reported observation that sublethal exposure to the fossilized remains of diatoms (i.e. diatomaceous earth) increases net fecundity (eggs produced minus eggs destroyed/day) of flour beetles, Tribolium confusum. The aim was to experimentally test two non-mutually-exclusive ecological mechanisms potentially responsible for the increased net fecundity: higher egg production and lower egg cannibalism. Adult T. confusum were maintained at low or high density in medium containing sublethal (0–4%) diatomaceous earth. Net fecundity increased up to 2.1× control values during diatomaceous earth exposure, and returned to control levels following removal from diatomaceous earth. Cannibalism assays on adults showed that diatomaceous earth reduced the number of eggs produced to 0.7× control values at low density and to 0.8× controls at high density, and also reduced egg cannibalism rates of adults to as little as 0.4× control values, but at high density only. Diatomaceous earth also reduced cannibalism by larvae on eggs to 0.3× control values. So, while the presence of diatomaceous earth reduced egg production, net fecundity increased as a result of strong suppression of the normal egg cannibalism by adults and larvae that occurs at high beetle density. Undisturbed cultures containing sublethal diatomaceous earth concentrations reached higher population densities than diatomaceous earth-free controls. Cohort studies on survival from egg to adult indicated that this population increase was due largely to decreased egg cannibalism by adult females. This is the first report of inhibition of egg cannibalism by diatomaceous earth on larval or adult insects. The ability of diatomaceous earth to alter cannibalism behavior without causing mortality makes it an ideal investigative tool for cannibalism

  3. Sublethal exposure to diatomaceous earth increases net fecundity of flour beetles (Tribolium confusum by inhibiting egg cannibalism.

    Directory of Open Access Journals (Sweden)

    Allen W Shostak

    Full Text Available Population regulation results from an interplay of numerous intrinsic and external factors, and for many insects cannibalism is such a factor. This study confirms a previously-reported observation that sublethal exposure to the fossilized remains of diatoms (i.e. diatomaceous earth increases net fecundity (eggs produced minus eggs destroyed/day of flour beetles, Tribolium confusum. The aim was to experimentally test two non-mutually-exclusive ecological mechanisms potentially responsible for the increased net fecundity: higher egg production and lower egg cannibalism. Adult T. confusum were maintained at low or high density in medium containing sublethal (0-4% diatomaceous earth. Net fecundity increased up to 2.1× control values during diatomaceous earth exposure, and returned to control levels following removal from diatomaceous earth. Cannibalism assays on adults showed that diatomaceous earth reduced the number of eggs produced to 0.7× control values at low density and to 0.8× controls at high density, and also reduced egg cannibalism rates of adults to as little as 0.4× control values, but at high density only. Diatomaceous earth also reduced cannibalism by larvae on eggs to 0.3× control values. So, while the presence of diatomaceous earth reduced egg production, net fecundity increased as a result of strong suppression of the normal egg cannibalism by adults and larvae that occurs at high beetle density. Undisturbed cultures containing sublethal diatomaceous earth concentrations reached higher population densities than diatomaceous earth-free controls. Cohort studies on survival from egg to adult indicated that this population increase was due largely to decreased egg cannibalism by adult females. This is the first report of inhibition of egg cannibalism by diatomaceous earth on larval or adult insects. The ability of diatomaceous earth to alter cannibalism behavior without causing mortality makes it an ideal investigative tool for

  4. Sublethal doses of neonicotinoid imidacloprid can interact with honey bee chemosensory protein 1 (CSP1) and inhibit its function.

    Science.gov (United States)

    Li, Hongliang; Tan, Jing; Song, Xinmi; Wu, Fan; Tang, Mingzhu; Hua, Qiyun; Zheng, Huoqing; Hu, Fuliang

    2017-04-29

    As a frequently used neonicotinoid insecticide, imidacloprid can impair the chemoreceptive behavior of honey bees even at sublethal doses, while the physiochemical mechanism has not been further revealed. Here, multiple fluorescence spectra, thermodynamic method, and molecular docking were used to study the interaction and the functional inhibition of imidacloprid to the recombinant CSP1 protein in Asian honey bee, Apis cerana. The results showed that the fluorescence intensity (λ em  = 332 nm) of CSP1 could be significantly quenched by imidacloprid in a dynamic mode. During the quenching process, ΔH > 0, ΔS > 0, indicating that the acting forces of imidacloprid with CSP1 are mainly hydrophobic interactions. Synchronous fluorescence showed that the fluorescence of CSP1 was mainly derived from tryptophan, and the hydrophobicity of tryptophan decreased with the increase of imidacloprid concentration. Molecular docking predicted the optimal pose and the amino acid composition of the binding process. Circular dichroism (CD) spectra showed that imidacloprid reduced the α-helix of CSP1 and caused the extension of the CSP1 peptide chain. In addition, the binding of CSP1 to floral scent β-ionone was inhibited by nearly 50% of the apparent association constant (K A ) in the presence of 0.28-2.53 ng/bee of imidacloprid, and the inhibition rate of nearly 95% at 3.75 ng/bee of imidacloprid at sublethal dose level. This study initially revealed the molecular physiochemical mechanism that sublethal doses of neonicotinoid still interact and inhibit the physiological function of the honey bees' chemoreceptive system. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Lethal and Sub-lethal Effects of Four Insecticides on the Aphidophagous Coccinellid Adalia bipunctata (Coleoptera: Coccinellidae).

    Science.gov (United States)

    Depalo, Laura; Lanzoni, Alberto; Masetti, Antonio; Pasqualini, Edison; Burgio, Giovanni

    2017-12-05

    Conventional insecticide assays, which measure the effects of insecticide exposure on short-term mortality, overlook important traits, including persistence of toxicity or sub-lethal effects. Therefore, such approaches are especially inadequate for prediction of the overall impact of insecticides on beneficial arthropods. In this study, the side effects of four modern insecticides (chlorantraniliprole, emamectin benzoate, spinosad, and spirotetramat) on Adalia bipunctata (L.) (Coleoptera: Coccinellidae) were evaluated under laboratory conditions by exposition on treated potted plants. In addition to investigation of acute toxicity and persistence of harmful activity in both larvae and adults of A. bipunctata, demographic parameters were evaluated, to provide a comprehensive picture of the nontarget effects of these products. Field doses of the four insecticides caused detrimental effects to A. bipunctata; but in different ways. Overall, spinosad showed the best toxicological profile among the products tested. Emamectin benzoate could be considered a low-risk insecticide, but had high persistence. Chlorantraniliprole exhibited lethal effects on early instar larvae and adults, along with a long-lasting activity, instead spirotetramat showed a low impact on larval and adult mortality and can be considered a short-lived insecticide. However, demographic analysis demonstrated that chlorantraniliprole and spirotetramat caused sub-lethal effects. Our findings highlight that sole assessment of mortality can lead to underestimation of the full impact of pesticides on nontarget insects. Demographic analysis was demonstrated to be a sensitive method for detection of the sub-lethal effects of insecticides on A. bipunctata, and this approach should be considered for evaluation of insecticide selectivity. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. Sub-lethal radiation enhances anti-tumor immunotherapy in a transgenic mouse model of pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Hanahan Douglas

    2002-05-01

    Full Text Available Abstract Background It is not uncommon to observe circulating tumor antigen-specific T lymphocytes in cancer patients despite a lack of significant infiltration and destruction of their tumors. Thus, an important goal for tumor immunotherapy is to identify ways to modulate in vivo anti-tumor immunity to achieve clinical efficacy. We investigate this proposition in a spontaneous mouse tumor model, Rip1-Tag2. Methods Experimental therapies were carried out in two distinctive trial designs, intended to either intervene in the explosive growth of small tumors, or regress bulky end-stage tumors. Rip1-Tag2 mice received a single transfer of splenocytes from Tag-specific, CD4+ T cell receptor transgenic mice, a single sub-lethal radiation, or a combination therapy in which the lymphocyte transfer was preceded by the sub-lethal radiation. Tumor burden, the extent of lymphocyte infiltration into solid tumors and host survival were used to assess the efficacy of these therapeutic approaches. Results In either intervention or regression, the transfer of Tag-specific T cells alone did not result in significant lymphocyte infiltration into solid tumors, not did it affect tumor growth or host survival. In contrast, the combination therapy resulted in significant reduction in tumor burden, increase in lymphocyte infiltration into solid tumors, and extension of survival. Conclusions The results indicate that certain types of solid tumors may be intrinsically resistant to infiltration and destruction by tumor-specific T lymphocytes. Our data suggest that such resistance can be disrupted by sub-lethal radiation. The combinatorial approach presented here merits consideration in the design of clinical trials aimed to achieve T cell-mediated anti-tumor immunity.

  7. Arsenic-induced sub-lethal stress reprograms human bronchial epithelial cells to CD61¯ cancer stem cells.

    Science.gov (United States)

    Chang, Qingshan; Chen, Bailing; Thakur, Chitra; Lu, Yongju; Chen, Fei

    2014-03-15

    In the present report, we demonstrate that sub-lethal stress induced by consecutive exposure to 0.25 µM arsenic (As3+) for six months can trigger reprogramming of the human bronchial epithelial cell (BEAS-2B) to form cancer stem cells (CSCs) without forced introduction of the stemness transcription factors. These CSCs formed from As3+-induced sub-lethal stress featured with an increased expression of the endogenous stemness genes, including Oct4, Sox2, Klf4, Myc, and others that are associated with the pluripotency and self-renewal of the CSCs. Flow cytometry analysis indicated that 90% of the CSC cells are CD61¯, whereas 100% of the parental cells are CD61+. These CD61¯ CSCs are highly tumorigenic and metastatic to the lung in xenotransplantation tests in NOD/SCID Il2rγ-/- mice. Additional tests also revealed that the CD61¯ CSCs showed a significant decrease in the expression of the genes important for DNA repair and oxidative phosphorylation. To determine the clinical relevance of the above findings, we stratified human lung cancers based on the level of CD61 protein and found that CD61low cancer correlates with poorer survival of the patients. Such a correlation was also observed in human breast cancer and ovarian cancer. Taken together, our findings suggest that in addition to the traditional approaches of enforced introduction of the exogenous stemness circuit transcription factors, sub-lethal stress induced by consecutive low dose As3+ is also able to convert non-stem cells to the CSCs.

  8. Effect of sub-lethal exposure to ultraviolet radiation on the escape performance of Atlantic cod larvae (Gadus morhua.

    Directory of Open Access Journals (Sweden)

    Yuichi Fukunishi

    Full Text Available The amount of ultraviolet (UV radiation reaching the earth's surface has increased due to depletion of the ozone layer. Several studies have reported that UV radiation reduces survival of fish larvae. However, indirect and sub-lethal impacts of UV radiation on fish behavior have been given little consideration. We observed the escape performance of larval cod (24 dph, SL: 7.6±0.2 mm; 29 dph, SL: 8.2±0.3 mm that had been exposed to sub-lethal levels of UV radiation vs. unexposed controls. Two predators were used (in separate experiments: two-spotted goby (Gobiusculus flavescens; a suction predator and lion's mane jellyfish (Cyanea capillata; a "passive" ambush predator. Ten cod larvae were observed in the presence of a predator for 20 minutes using a digital video camera. Trials were replicated 4 times for goby and 5 times for jellyfish. Escape rate (total number of escapes/total number of attacks ×100, escape distance and the number of larvae remaining at the end of the experiment were measured. In the experiment with gobies, in the UV-treated larvae, both escape rate and escape distance (36%, 38±7.5 mm respectively were significantly lower than those of control larvae (75%, 69±4.7 mm respectively. There was a significant difference in survival as well (UV: 35%,63%. No apparent escape response was observed, and survival rate was not significantly different, between treatments (UV: 66%,74% in the experiment with jellyfish. We conclude that the effect and impact of exposure to sub-lethal levels of UV radiation on the escape performance of cod larvae depends on the type of predator. Our results also suggest that prediction of UV impacts on fish larvae based only on direct effects are underestimations.

  9. Low salinity enhances NI-mediated oxidative stress and sub-lethal toxicity to the green shore crab (Carcinus maenas).

    Science.gov (United States)

    Blewett, Tamzin A; Wood, Chris M

    2015-12-01

    Nickel (Ni) is a metal of environmental concern, known to cause toxicity to freshwater organisms by impairing ionoregulation and/or respiratory gas exchange, and by inducing oxidative stress. However, little is known regarding how nickel toxicity is influenced by salinity. In the current study we investigated the salinity-dependence and mechanisms of sub-lethal Ni toxicity in a euryhaline crab (Carcinus maenas). Crabs were acclimated to three experimental salinities--20, 60 and 100% seawater (SW)--and exposed to 3mg/L Ni for 24h or 96 h. Tissues were dissected for analysis of Ni accumulation, gills were taken for oxidative stress analysis (catalase activity and protein carbonyl content), haemolymph ions were analysed for ionoregulatory disturbance, and oxygen consumption was determined in exercised crabs after 96 h of Ni exposure. Total Ni accumulation was strongly dependant on salinity, with crabs from 20% SW displaying the highest tissue Ni burdens after both 24 and 96-h exposures. After 96 h of exposure, the highest accumulation of Ni occurred in the posterior (ionoregulatory) gills at the lowest salinity, 20% SW. Posterior gill 8 exhibited elevated protein carbonyl levels and decreased catalase activity after Ni exposure, but only in 20% SW. Similarly, decreased levels of haemolymph Mg and K and an increased level of Ca were recorded but only in crabs exposed to Ni for 96 h in 20% SW. Oxygen consumption after exercise was also inhibited in crabs exposed to Ni in 20% SW. These data show for the first time the simultaneous presence of all three modes of sub-lethal Ni toxicity in exposed animals, and indicate a strong salinity dependence of sub-lethal Ni toxicity to the euryhaline crab, C. maenas, a pattern that corresponded to tissue Ni accumulation. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Sublethal exposure to diatomaceous earth increases net fecundity of flour beetles (Tribolium confusum) by inhibiting egg cannibalism.

    Science.gov (United States)

    Shostak, Allen W

    2014-01-01

    Population regulation results from an interplay of numerous intrinsic and external factors, and for many insects cannibalism is such a factor. This study confirms a previously-reported observation that sublethal exposure to the fossilized remains of diatoms (i.e. diatomaceous earth) increases net fecundity (eggs produced minus eggs destroyed/day) of flour beetles, Tribolium confusum. The aim was to experimentally test two non-mutually-exclusive ecological mechanisms potentially responsible for the increased net fecundity: higher egg production and lower egg cannibalism. Adult T. confusum were maintained at low or high density in medium containing sublethal (0-4%) diatomaceous earth. Net fecundity increased up to 2.1× control values during diatomaceous earth exposure, and returned to control levels following removal from diatomaceous earth. Cannibalism assays on adults showed that diatomaceous earth reduced the number of eggs produced to 0.7× control values at low density and to 0.8× controls at high density, and also reduced egg cannibalism rates of adults to as little as 0.4× control values, but at high density only. Diatomaceous earth also reduced cannibalism by larvae on eggs to 0.3× control values. So, while the presence of diatomaceous earth reduced egg production, net fecundity increased as a result of strong suppression of the normal egg cannibalism by adults and larvae that occurs at high beetle density. Undisturbed cultures containing sublethal diatomaceous earth concentrations reached higher population densities than diatomaceous earth-free controls. Cohort studies on survival from egg to adult indicated that this population increase was due largely to decreased egg cannibalism by adult females. This is the first report of inhibition of egg cannibalism by diatomaceous earth on larval or adult insects. The ability of diatomaceous earth to alter cannibalism behavior without causing mortality makes it an ideal investigative tool for cannibalism studies.

  11. NSUF Irradiated Materials Library

    Energy Technology Data Exchange (ETDEWEB)

    Cole, James Irvin [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    The Nuclear Science User Facilities has been in the process of establishing an innovative Irradiated Materials Library concept for maximizing the value of previous and on-going materials and nuclear fuels irradiation test campaigns, including utilization of real-world components retrieved from current and decommissioned reactors. When the ATR national scientific user facility was established in 2007 one of the goals of the program was to establish a library of irradiated samples for users to access and conduct research through competitively reviewed proposal process. As part of the initial effort, staff at the user facility identified legacy materials from previous programs that are still being stored in laboratories and hot-cell facilities at the INL. In addition other materials of interest were identified that are being stored outside the INL that the current owners have volunteered to enter into the library. Finally, over the course of the last several years, the ATR NSUF has irradiated more than 3500 specimens as part of NSUF competitively awarded research projects. The Logistics of managing this large inventory of highly radioactive poses unique challenges. This document will describe materials in the library, outline the policy for accessing these materials and put forth a strategy for making new additions to the library as well as establishing guidelines for minimum pedigree needed to be included in the library to limit the amount of material stored indefinitely without identified value.

  12. Childhood Head and Neck Irradiation

    Science.gov (United States)

    ... Thyroid Association ® www.thyroid.org Childhood Head & Neck Irradiation What is the thyroid gland? The thyroid gland ... Thyroid Association ® www.thyroid.org Childhood Head & Neck Irradiation Thyroid nodules (see Thyroid Nodule brochure) • Thyroid nodules ...

  13. Protective Effects of Hong Shan Capsule against Lethal Total-Body Irradiation-Induced Damage in Wistar Rats

    Directory of Open Access Journals (Sweden)

    Jianzhong Li

    2015-08-01

    Full Text Available Hong Shan Capsule (HSC, a crude drug of 11 medicinal herbs, was used in clinical practice for the treatment of radiation injuries in China. In this study, we investigated its protection in rats against acute lethal total-body irradiation (TBI. Pre-administration of HSC reduced the radiation sickness characteristics, while increasing the 30-day survival of the irradiated rats. Administration of HSC also reduced the radiation sickness characteristics and increased the 30-day survival of mice after exposure to lethal TBI. Ultrastructural observation illustrated that the pretreatment of rats with HSC significantly attenuated the TBI-induced morphological changes in the different organs of irradiated rats. Gene expression profiles revealed the dramatic effect of HSC on alterations of gene expression caused by lethal TBI. Pretreatment with HSC prevented differential expression of 66% (1398 genes of 2126 genes differentially expressed in response to TBI. Pathway enrichment analysis indicated that these genes were mainly involved in a total of 32 pathways, such as pathways in cancer and the mitogen-activated protein kinase (MAPK signaling pathway. Our analysis indicated that the pretreatment of rats with HSC modulated these pathways induced by lethal TBI, such as multiple MAPK pathways, suggesting that pretreatment with HSC might provide protective effects on lethal TBI mainly or partially through the modulation of these pathways. Our data suggest that HSC has the potential to be used as an effective therapeutic or radio-protective agent to minimize irradiation damage.

  14. Pretreatment of Reed by Wet Oxidation and Subsequent Utilization of the Pretreated Fibers for Ethanol Production

    DEFF Research Database (Denmark)

    Szijarto, Nora; Kádár, Zsófia; Varga, Eniko

    2009-01-01

    lignocelluloses usually do. In the present study, wet oxidation was investigated as the pretreatment method to enhance the enzymatic digestibility of reed cellulose to soluble sugars and thus improve the convertibility of reed to ethanol. The most effective treatment increased the digestibility of reed cellulose...... of cellulose to glucose was 82.4%. Simultaneous saccharification and fermentation of pretreated solids resulted in a final ethanol concentration as high as 8.7 g/L, yielding 73% of the theoretical....

  15. Investigations into the effect of immunostimulating drugs on the immune system of irradiated experimental animals. Final report. Untersuchung ueber den Einfluss von Immunmediatoren auf das Immunsystem bei bestrahlten Versuchstieren. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Buschmann, H.; Kleinschmidt, A.; Koeppel, P.; Winter, M.

    1989-01-01

    In experiments with mice and pigs a sublethal irradiation before vaccination proved to be by far more efficient than an irradiation with the same dose following vaccination. In the irradiated animals a retarded beginning of the immune response compared with the controls was observed. In the experiments with mice positive effects of the adjuvant azimexon and levamisol on the radiation induced immunosuppression was seen. In the experiments with pigs the radiation iduced immunosuppression was completely abolished by addition of incomplete Freund adjuvant to the antigen. Azimexon as adjuvant was efficient both when given before or after exposition. Post-endotoxic serum from BCG-infected animals (BCG/ET) had only a weak effect in animals immunized before exposition. Serum immunoglobulin levels of pigs were stable against irradiation and application of immunomodulating agents. Stimulation effects of the irradiation on the antibody response were observed in mice and pigs if the animals were first immunized and irradiated afterwards. In the irradiated pigs the mitogenic stimulation of T and B cells was depressed. After application of azimexon the stimulation of T cells was significantly increased in irradiated pigs; the impaired B cell stimulation, however, remained unaltered. By using the monoclonal antibody technique functionally distinct subpopulations of peripherals lymphocytes in swine were detected, each showing a different sensibility towards in vivo irradiation. (orig.) With 10 refs., 21 figs.

  16. Evolution of biochemical parameters in irradiated fishes: Serum proteins and intestinal nucleic acids; Evolucion de parametros bioquimicos en peces irradiados: Proteinas en suero y acidos nucleicos en intestino

    Energy Technology Data Exchange (ETDEWEB)

    Garces, F.; Andres, P.; Davila, C. A.

    1976-07-01

    In sublethal gamma-irradiated C. auratus, a sudden decrease of total serum protein concentration and a preferential descent of the low molecular weight gamma-globulin fraction have been observed. These effects are transient and after different latent periods dependent on doses, normal values are recovered, A temporal failure of a vascular permeability regulation system is probably implied. The DMA depolymerization. observed in the intestine indicates the action of radio-induced DNA degradation mechanisms since this effect is independent on doses. (Author) 29 refs.

  17. Influence of pretreatment polarographically measured oxygenation levels in spontaneous canine tumors treated with radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Bley, C.R.; Ohlerth, S.; Wergin, M.; Achermann, R.; Kaser-Hotz, B. [Section of Diagnostic Imaging and Radiation Oncology, Vetsuisse Faculty, Univ. of Zurich (Switzerland); Roos, M. [Biostatistics, ISPM, Univ. of Zurich (Switzerland)

    2006-09-15

    Background and purpose: the level of hypoxia in primary tumors has been described to influence response to treatment. The aim of the present study was to investigate the impact of pretreatment oxygen level measurements in spontaneous canine tumors on treatment outcome. Material and methods: data of pretreatment tumor oxygenation status and local tumor response after primary radiation therapy in a group of spontaneously occurring tumors in dogs (n = 52) was collected. Radiation therapy was given with curative (14-17 x 3-3.5 Gy) or palliative intent (3 x 8 Gy or 4-5 x 6 Gy). Progression-free interval and overall survival were correlated to polarographically measured tumor oxygenation status. Results: in the curatively irradiated group, tumors with median p0{sub 2} values {<=} 10 mmHg tended to have shorter median progression-free interval compared to better oxygenated tumors (246 vs. 739 days). The same trend could be shown for overall survival (330 vs. 745 days), indicating a cutoff value in this region. In the group treated with lower doses of radiation, the level of oxygen was no longer found to be of prognostic value; however, in this group hemoglobin had a significant impact on outcome. Conclusion: in curatively irradiated spontaneous canine tumors, tumor hypoxia was found to be a prognostic indicator, independent of tumor histologies and volume. (orig.)

  18. Enhanced biohydrogen and subsequent biomethane production from sugarcane bagasse using nano-titanium dioxide pretreatment.

    Science.gov (United States)

    Jafari, Omid; Zilouei, Hamid

    2016-08-01

    Nano-titanium dioxide (nanoTiO2) under ultraviolet irradiation (UV) followed by dilute sulfuric acid hydrolysis of sugarcane bagasse was used to enhance the production of biohydrogen and biomethane in a consecutive dark fermentation and anaerobic digestion. Different concentrations of 0.001, 0.01, 0.1 and 1g nanoTiO2/L under different UV times of 30, 60, 90 and 120min were used. Sulfuric acid (2%v/v) at 121°C was used for 15, 30 and 60min to hydrolyze the pretreated bagasse. For acidic hydrolysis times of 15, 30 and 60min, the highest total free sugar values were enhanced by 260%, 107%, and 189%, respectively, compared to samples without nanoTiO2 pretreatment. The highest hydrogen production samples for the same acidic hydrolysis times showed 88%, 127%, and 25% enhancement. The maximum hydrogen production of 101.5ml/g VS (volatile solids) was obtained at 1g nanoTiO2/L and 120min UV irradiation followed by 30min acid hydrolysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Improving enzymatic hydrolysis of industrial hemp (Cannabis sativa L.) by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Soo-Jeong [Chungbuk National University, Cheongju, Chungbuk 361-763 (Korea, Republic of); Sung, Yong Joo [KT and G Central Research Institute, 302 Shinseong-Dong, Yuseong-Gu, Daejeon 305-805 (Korea, Republic of)], E-mail: yosung17@yahoo.co.kr

    2008-09-15

    The electron beam irradiation was applied as a pretreatment of the enzymatic hydrolysis of hemp biomass with doses of 150, 300 and 450 kGy. The higher irradiation dose resulted in the more extraction with hot-water extraction or 1% sodium hydroxide solution extraction. The higher solubility of the treated sample was originated from the chains scission during irradiation, which was indirectly demonstrated by the increase of carbonyl groups as shown in diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) spectra. The changes in the micro-structure of hemp resulted in the better response to enzymatic hydrolysis with commercial cellulases (Celluclast 1.5L and Novozym 342). The improvement in enzymatic hydrolysis by the irradiation was more evident in the hydrolysis of the xylan than in that of the cellulose.

  20. Selection of a multidrug resistance plasmid by sublethal levels of antibiotics and heavy metals.

    Science.gov (United States)

    Gullberg, Erik; Albrecht, Lisa M; Karlsson, Christoffer; Sandegren, Linus; Andersson, Dan I

    2014-10-07

    How sublethal levels of antibiotics and heavy metals select for clinically important multidrug resistance plasmids is largely unknown. Carriage of plasmids generally confers substantial fitness costs, implying that for the plasmid-carrying bacteria to be maintained in the population, the plasmid cost needs to be balanced by a selective pressure conferred by, for example, antibiotics or heavy metals. We studied the effects of low levels of antibiotics and heavy metals on the selective maintenance of a 220-kbp extended-spectrum β-lactamase (ESBL) plasmid identified in a hospital outbreak of Klebsiella pneumoniae and Escherichia coli. The concentrations of antibiotics and heavy metals required to maintain plasmid-carrying bacteria, the minimal selective concentrations (MSCs), were in all cases below (almost up to 140-fold) the MIC of the plasmid-free susceptible bacteria. This finding indicates that the very low antibiotic and heavy metal levels found in polluted environments and in treated humans and animals might be sufficiently high to maintain multiresistance plasmids. When resistance genes were moved from the plasmid to the chromosome, the MSC decreased, showing that MSC for a specific resistance conditionally depends on genetic context. This finding suggests that a cost-free resistance could be maintained in a population by an infinitesimally low concentration of antibiotic. By studying the effect of combinations of several compounds, it was observed that for certain combinations of drugs each new compound added lowered the minimal selective concentration of the others. This combination effect could be a significant factor in the selection of multidrug resistance plasmids/bacterial clones in complex multidrug environments. Importance: Antibiotic resistance is in many pathogenic bacteria caused by genes that are carried on large conjugative plasmids. These plasmids typically contain multiple antibiotic resistance genes as well as genes that confer resistance to

  1. Assessment of chronic sublethal effects of imidacloprid on honey bee colony health.

    Directory of Open Access Journals (Sweden)

    Galen P Dively

    Full Text Available Here we present results of a three-year study to determine the fate of imidacloprid residues in hive matrices and to assess chronic sublethal effects on whole honey bee colonies fed supplemental pollen diet containing imidacloprid at 5, 20 and 100 μg/kg over multiple brood cycles. Various endpoints of colony performance and foraging behavior were measured during and after exposure, including winter survival. Imidacloprid residues became diluted or non-detectable within colonies due to the processing of beebread and honey and the rapid metabolism of the chemical. Imidacloprid exposure doses up to 100 μg/kg had no significant effects on foraging activity or other colony performance indicators during and shortly after exposure. Diseases and pest species did not affect colony health but infestations of Varroa mites were significantly higher in exposed colonies. Honey stores indicated that exposed colonies may have avoided the contaminated food. Imidacloprid dose effects was delayed later in the summer, when colonies exposed to 20 and 100 μg/kg experienced higher rates of queen failure and broodless periods, which led to weaker colonies going into the winter. Pooled over two years, winter survival of colonies averaged 85.7, 72.4, 61.2 and 59.2% in the control, 5, 20 and 100 μg/kg treatment groups, respectively. Analysis of colony survival data showed a significant dose effect, and all contrast tests comparing survival between control and treatment groups were significant, except for colonies exposed to 5 μg/kg. Given the weight of evidence, chronic exposure to imidacloprid at the higher range of field doses (20 to 100 μg/kg in pollen of certain treated crops could cause negative impacts on honey bee colony health and reduced overwintering success, but the most likely encountered high range of field doses relevant for seed-treated crops (5 μg/kg had negligible effects on colony health and are unlikely a sole cause of colony declines.

  2. The sensitive hare: sublethal effects of predator stress on reproduction in snowshoe hares.

    Science.gov (United States)

    Sheriff, Michael J; Krebs, Charles J; Boonstra, Rudy

    2009-11-01

    1. Prey responses to high predation risk can be morphological or behavioural and ultimately come at the cost of survival, growth, body condition, or reproduction. These sub-lethal predator effects have been shown to be mediated by physiological stress. We tested the hypothesis that elevated glucocorticoid concentrations directly cause a decline in reproduction in individual free-ranging female snowshoe hares, Lepus americanus. We measured the cortisol concentration from each dam (using a faecal analysis enzyme immunoassay) and her reproductive output (litter size, offspring birth mass, offspring right hind foot (RHF) length) 30 h after birth. 2. In a natural monitoring study, we monitored hares during the first and second litter from the population peak (2006) to the second year of the decline (2008). We found that faecal cortisol metabolite (FCM) concentration in dams decreased 52% from the first to the second litter. From the first to the second litter, litter size increased 122%, offspring body mass increased 130%, and offspring RHF length increased 112%. Dam FCM concentrations were inversely related to litter size (r(2) = 0.19), to offspring birth mass (r(2) = 0.32), and to offspring RHF length (r(2) = 0.64). 3. In an experimental manipulation, we assigned wild-caught, pregnant hares to a control and a stressed group and held them in pens. Hares in the stressed group were exposed to a dog 1-2 min every other day before parturition to simulate high predation risk. At parturition, unsuccessful-stressed dams (those that failed to give birth to live young) and stressed dams had 837% and 214%, respectively, higher FCM concentrations than control dams. Of those females that gave birth, litter size was similar between control and stressed dams. However, offspring from stressed dams were 37% lighter and 16% smaller than offspring from control dams. Increasing FCM concentration in dams caused the decline of offspring body mass (r(2) = 0.57) and RHF (r(2) = 0.52). 4

  3. TiO2-Based Photocatalytic Treatment of Raw and Constructed-Wetland Pretreated Textile Wastewater

    Directory of Open Access Journals (Sweden)

    Dunja Mahne

    2012-01-01

    Full Text Available Approximately, 15% of the total textile colorant production is estimated to be lost during dyeing and processing of textile fibres. If left untreated, these wastewaters can represent a serious environmental threat. In the present paper a combination of photocatalytic and biological degradation of prepared textile wastewaters (simulation of real textile effluent is presented. Samples have been monitored through the course of photocatalytic experiments: change in UV-VIS absorbance spectra and complete decolouration were achieved for all three tested dyed wastewaters; however, only partial COD removal was achieved with photocatalytic oxidation (PCOx and photocatalytic ozonation (PCOz. Toxicity test (Vibrio fischeri of untreated and pretreated (constructed wetland, CW samples showed a decrease in toxicity values only for the red-dyed wastewater. Comparison of efficiency of PCOx and PCOz for decolouration and mineralization of three structurally different dyes (anthraquinone and two azo dyes has been done. CW pretreatment caused faster decolouration and substantial COD removal in PCOx (up to 45%. Pretreatment also accelerated decolouration during PCOz, but it accelerated COD removal only in the case of red-dyed wastewater due to short irradiation times applied.

  4. Growth hormone mitigates against lethal irradiation and enhances hematologic and immune recovery in mice and nonhuman primates.

    Directory of Open Access Journals (Sweden)

    Benny J Chen

    Full Text Available Medications that can mitigate against radiation injury are limited. In this study, we investigated the ability of recombinant human growth hormone (rhGH to mitigate against radiation injury in mice and nonhuman primates. BALB/c mice were irradiated with 7.5 Gy and treated post-irradiation with rhGH intravenously at a once daily dose of 20 microg/dose for 35 days. rhGH protected 17 out of 28 mice (60.7% from lethal irradiation while only 3 out of 28 mice (10.7% survived in the saline control group. A shorter course of 5 days of rhGH post-irradiation produced similar results. Compared with the saline control group, treatment with rhGH on irradiated BALB/c mice significantly accelerated overall hematopoietic recovery. Specifically, the recovery of total white cells, CD4 and CD8 T cell subsets, B cells, NK cells and especially platelets post radiation exposure were significantly accelerated in the rhGH-treated mice. Moreover, treatment with rhGH increased the frequency of hematopoietic stem/progenitor cells as measured by flow cytometry and colony forming unit assays in bone marrow harvested at day 14 after irradiation, suggesting the effects of rhGH are at the hematopoietic stem/progenitor level. rhGH mediated the hematopoietic effects primarily through their niches. Similar data with rhGH were also observed following 2 Gy sublethal irradiation of nonhuman primates. Our data demonstrate that rhGH promotes hematopoietic engraftment and immune recovery post the exposure of ionizing radiation and mitigates against the mortality from lethal irradiation even when administered after exposure.

  5. Relationship between Sublethal Injury and Microbial Inactivation by the Combination of High Hydrostatic Pressure and Citral or tert-Butyl Hydroquinone ▿

    Science.gov (United States)

    Somolinos, Maria; García, Diego; Pagán, Rafael; Mackey, Bernard

    2008-01-01

    The aim was to investigate (i) the occurrence of sublethal injury in Listeria monocytogenes, Escherichia coli, and Saccharomyces cerevisiae after high hydrostatic pressure (HHP) treatment as a function of the treatment medium pH and composition and (ii) the relationship between the occurrence of sublethal injury and the inactivating effect of a combination of HHP and two antimicrobial compounds, tert-butyl hydroquinone (TBHQ) and citral. The three microorganisms showed a high proportion of sublethally injured cells (up to 99.99% of the surviving population) after HHP. In E. coli and L. monocytogenes, the extent of inactivation and sublethal injury depended on the pH and the composition of the treatment medium, whereas in S. cerevisiae, inactivation and sublethal injury were independent of medium pH or composition under the conditions tested. TBHQ alone was not lethal to E. coli or L. monocytogenes but acted synergistically with HHP and 24-h refrigeration, resulting in a viability decrease of >5 log10 cycles of both organisms. The antimicrobial effect of citral depended on the microorganism and the treatment medium pH. Acting alone for 24 h under refrigeration, 1,000 ppm of citral caused a reduction of 5 log10 cycles of E. coli at pH 7.0 and almost 3 log10 cycles of L. monocytogenes at pH 4.0. The combination of citral and HHP also showed a synergistic effect. Our results have confirmed that the detection of sublethal injury after HHP may contribute to the identification of those treatment conditions under which HHP may act synergistically with other preserving processes. PMID:18952869

  6. A single exposure to a sublethal pediocin concentration initiates a resistance-associated temporal cell envelope and general stress response in Listeria monocytogenes

    DEFF Research Database (Denmark)

    Laursen, Martin Frederik; Bahl, Martin Iain; Licht, Tine Rask

    2015-01-01

    was to determine if exposure to sublethal concentrations of pediocin-containing Lactobacillus plantarum WHE 92 supernatant could prime L. monocytogenes for resistance. By transcriptomic analysis, we found two, 55 and 539 genes differentially expressed after 10, 60 and 180 min of exposure to L. plantarum WHE 92...... resistant than wild types to L. plantarum WHE 92 supernatant. LisRK, SigB and SigL regulation and genes associated with resistance are involved in the temporal adaptive response to pediocin and all three regulatory systems affect pediocin resistance. Thus, a single exposure to a sublethal pediocin...

  7. Sublethal impact of short term exposure to the organophosphate pesticide azamethiphos in the marine mollusc Mytilus edulis.

    Science.gov (United States)

    Canty, M N; Hagger, J A; Moore, R T B; Cooper, L; Galloway, T S

    2007-04-01

    Concern has been raised that the increased use of pesticides in intensive aquaculture practices may cause adverse sublethal effects to non-target aquatic species. Azamethiphos is an organophosphate (OP) pesticide used to combat sea lice infestations in farmed salmonids. Here, the sublethal impact on the blue mussel, Mytilus edulis, of short term exposure to azamethiphos was determined. The testing regime included biomarkers of exposure (acetylcholinesterase activity), cytotoxicity (neutral red retention), immune function (phagocytic index) and physiological condition (feeding rate). The distribution and sensitivity of M. edulis acetylcholinesterase to inhibition by azamethiphos was first determined, yielding IC(50) values of 0.736 and 1.30 mg l(-1) for gill and haemolymph, respectively. Exposure of mussels to 0.1 mg l(-1) azamethiphos for periods of up to 24h caused a significant reduction in acetylcholinesterase activity in both the haemolymph (Pgill (P<0.002), alteration in cell viability (P<0.02) and decrease in phagocytic index (P<0.03). The feeding rate remained unaffected. The results support the hypothesis that, in addition to its neurotoxic effects, azamethiphos can modulate haemocyte function and immune defence in M. edulis at environmentally relevant concentrations after only a few hours.

  8. Sub-lethal effects of essential oil of Lippia sidoides on drywood termite Cryptotermes brevis (Blattodea: Termitoidea).

    Science.gov (United States)

    Santos, Abraão Almeida; de Oliveira, Bruna Maria Santos; Melo, Carlisson Ramos; Lima, Ana Paula Santana; Santana, Emile Dayara Rabelo; Blank, Arie Fitzgerald; Picanço, Marcelo Coutinho; Araújo, Ana Paula Albano; Cristaldo, Paulo Fellipe; Bacci, Leandro

    2017-11-01

    The drywood termite Cryptotermes brevis (Walker, 1853) (Kalotermitidae) is one of the most important wood structural pest in the world. Substances from the secondary metabolism of plants (e.g., essential oils) have been considered an environmentally safer form of control for urban pests, such as termites. In the present study, we analyzed the lethal and sub-lethal effects of essential oil of Lippia sidoides and its major components on C. brevis pseudergates in two routes of exposure (contact and fumigation). The essential oil of L. sidoides and thymol were more toxic to C. brevis pseudergates when applied by contact (LD50 = 9.33 and 8.20µgmg(-1), respectively) and by fumigation (LC50 = 9.10 and 23.6µLL(-1), respectively). In general, treatments changed the individual and collective behaviors of C. brevis pseudergates, as well as the displacement and walking speed. The essential oil of L. sidoides and its major components showed a high potential to control C. brevis pseudergates, due to the bioactivity in the two routes of exposure and the sub-lethal effects on the behavior and walking, important activities for the cohesion of C. brevis colonies. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. In Vitro Evaluation of Sub-Lethal Concentrations of Plant-Derived Antifungal Compounds on FUSARIA Growth and Mycotoxin Production

    Directory of Open Access Journals (Sweden)

    Caterina Morcia

    2017-07-01

    Full Text Available Phytopathogenic fungi can lead to significant cereal yield losses, also producing mycotoxins dangerous for human and animal health. The fungal control based on the use of synthetic fungicides can be complemented by "green" methods for crop protection, based on the use of natural products. In this frame, the antifungal activities of bergamot and lemon essential oils and of five natural compounds recurrent in essential oils (citronellal, citral, cinnamaldehyde, cuminaldehyde and limonene have been evaluated against three species of mycotoxigenic fungi (Fusarium sporotrichioides, F. graminearum and F. langsethiae responsible for Fusarium Head Blight in small-grain cereals. The natural products concentrations effective for reducing or inhibiting the in vitro fungal growth were determined for each fungal species and the following scale of potency was found: cinnamaldehyde > cuminaldehyde > citral > citronellal > bergamot oil > limonene > lemon oil. Moreover, the in vitro mycotoxin productions of the three Fusaria strains exposed to sub-lethal concentrations of the seven products was evaluated. The three fungal species showed variability in response to the treatments, both in terms of inhibition of mycelial growth and in terms of modulation of mycotoxin production that can be enhanced by sub-lethal concentrations of some natural products. This last finding must be taken into account in the frame of an open field application of some plant-derived fungicides.

  10. Acute and sub-lethal exposure to copper oxide nanoparticles causes oxidative stress and teratogenicity in zebrafish embryos.

    Science.gov (United States)

    Ganesan, Santhanamari; Anaimalai Thirumurthi, Naveenkumar; Raghunath, Azhwar; Vijayakumar, Savitha; Perumal, Ekambaram

    2016-04-01

    Nano-copper oxides are a versatile inorganic material. As a result of their versatility, the immense applications and usage end up in the environment causing a concern for the lifespan of various beings. The ambiguities surround globally on the toxic effects of copper oxide nanoparticles (CuO-NPs). Hence, the present study endeavored to study the sub-lethal acute exposure effects on the developing zebrafish embryos. The 48 hpf LC50 value was about 64 ppm. Therefore, we have chosen the sub-lethal dose of 40 and 60 ppm for the study. Accumulation of CuO-NPs was evidenced from the SEM-EDS and AAS analyzes. The alterations in the AChE and Na(+)/K(+)-ATPase activities disrupted the development process. An increment in the levels of oxidants with a concomitant decrease in the antioxidant enzymes confirmed the induction of oxidative stress. Oxidative stress triggered apoptosis in the exposed embryos. Developmental anomalies were observed with CuO-NPs exposure in addition to oxidative stress in the developing embryos. Decreased heart rate and hatching delay hindered the normal developmental processes. Our work has offered valuable data on the connection between oxidative stress and teratogenicity leading to lethality caused by CuO-NPs. A further molecular mechanism unraveling the uncharted connection between oxidative stress and teratogenicity will aid in the safe use of CuO-NPs. Copyright © 2015 John Wiley & Sons, Ltd.

  11. Metabolic responses of Eisenia fetida after sub-lethal exposure to organic contaminants with different toxic modes of action

    Energy Technology Data Exchange (ETDEWEB)

    McKelvie, Jennifer R.; Wolfe, David M.; Celejewski, Magda A. [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail Toronto, ON M1C 1A4 (Canada); Alaee, Mehran [Environment Canada, 867 Lakeshore Rd., P.O. Box 5050, Burlington, ON L7R 4A6 (Canada); Simpson, Andre J. [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail Toronto, ON M1C 1A4 (Canada); Simpson, Myrna J., E-mail: myrna.simpson@utoronto.ca [Department of Physical and Environmental Sciences, University of Toronto, 1265 Military Trail Toronto, ON M1C 1A4 (Canada)

    2011-12-15

    Nuclear magnetic resonance (NMR) - based metabolomics has the potential to identify toxic responses of contaminants within a mixture in contaminated soil. This study evaluated the metabolic response of Eisenia fetida after exposure to an array of organic compounds to determine whether contaminant-specific responses could be identified. The compounds investigated in contact tests included: two pesticides (carbaryl and chlorpyrifos), three pharmaceuticals (carbamazephine, estrone and caffeine), two persistent organohalogens (Aroclor 1254 and PBDE 209) and two industrial compounds (nonylphenol and dimethyl phthalate). Control and contaminant-exposed metabolic profiles were distinguished using principal component analysis and potential contaminant-specific biomarkers of exposure were found for several contaminants. These results suggest that NMR-based metabolomics offers considerable promise for differentiating between the different toxic modes of action (MOA) associated with sub-lethal toxicity to earthworms. - Highlights: > NMR-based earthworm metabolomic analysis of the toxic mode of action of various environmental contaminants. > Organic chemicals with different toxic modes of action resulted in varied metabolomic responses for E. fetida. > NMR-based metabolomics differentiates between the different modes of action associated with sub-lethal toxicity. - {sup 1}H NMR metabolomics was used to identify potential biomarkers of organic contaminant exposure in Eisenia fetida earthworms.

  12. Sublethal effect of pyriproxyfen released from a fumigant formulation on fecundity, fertility, and ovicidal action in Aedes aegypti (Diptera: Culicidae).

    Science.gov (United States)

    Harburguer, Laura; Zerba, Eduardo; Licastro, Susana

    2014-03-01

    Dengue and dengue hemorrhagic fever are mosquito-borne viral diseases that coincide with the distribution of Aedes aegypti (L.), the primary vector in the tropical and semitropical world. With no available vaccine, controlling the dengue vector is essential to prevent epidemics. The effects of the insect growth regulator pyriproxyfen on Ae. aegypti adults that survived a treatment with a sublethal dose were investigated in the laboratory, including effects on their reproductive potential. Pyriproxyfen was released from a fumigant formulation at a dose causing 20 or 40% emergence inhibition (%EI). Females were dissected before and after blood feeding and the basal follicle number was counted. There were no differences between the control and treated group on the basal follicle number for both doses used. Fertility and fecundity were reduced at a concentration of EI40 but no at EI20. There was no ovicidal effect of pyriproxyfen by immersion of eggs in treated water neither when the females laid their eggs on a pyriproxyfen-treated surface. This work shows that sublethal doses of pyriproxyfen can have effects on fertility and fecundity ofAe. aegypti females, which together with its larvicidal activity could contribute to an overall decrease in a given population.

  13. Investigation of irradiated rats DNA in the presence of Cu(II) chelates of amino acids Schiff bases.

    Science.gov (United States)

    Karapetyan, N H; Torosyan, A L; Malakyan, M; Bajinyan, S A; Haroutiunian, S G

    2016-01-01

    The new synthesized Cu(II) chelates of amino acids Schiff bases were studied as a potential radioprotectors. Male albino rats of Wistar strain were exposed to X-ray whole-body irradiation at 4.8 Gy. This dose caused 30% mortality of the animals (LD30). The survival of animals exposed to radiation after preliminary administration of 10 mg/kg Cu(II)(Nicotinyl-L-Tyrosinate)2 or Cu(II)(Nicotinyl-L-Tryptophanate)2 prior to irradiation was registered about 80 and 100% correspondingly. Using spectrophotometric melting and agarose gel electrophoresis methods, the differences between the DNA isolated from irradiated rats and rats pretreated with Cu(II) chelates were studied. The fragments of DNA with different breaks were revealed in DNA samples isolated from irradiated animals. While, the repair of the DNA structure was observed for animals pretreated with the Cu(II) chelates. The results suggested that pretreatment of the irradiated rats with Cu(II)(Nicotinyl-L-Tyrosinate)2 and Cu(II)(Nicotinyl-L-Tryptophanate)2 compounds improves the liver DNA characteristics.

  14. Possibilities and evaluation of straw pretreatment

    DEFF Research Database (Denmark)

    Knudsen, Niels Ole; Jensen, Peter Arendt; Sander, Bo

    1998-01-01

    Biomass utilisation by cofiring of straw in a pulverised coal fire boiler is economically attractive compared to dedicated straw fired plants. However, the high content of potassium and chloride impedes utilisation of the fly ash, deactivates the de NOx catalysts in the flue gas cleaning system...... and may also lead to increased deposit formation. A pretreatment process is required to solve the problems. In this paper two pretreatment processes are considred, one based on straw wash and another based on pyrolysis and char wash. To evaluate and compare the processes, laboratory and technical...... invetsigations were performed. The economy of both processes are favourable compared with seperate straw fired boilers, however, the removal efficiency of potassium of the pyrolysi based process is relatively low. At the present level of invetsigations the straw wash process looks promising and commercially...

  15. Pretreatment of Latent Prints for Laser Development.

    Science.gov (United States)

    Menzel, E R

    1989-06-01

    The pretreatment procedures for laser detection of latent fingerprints is reviewed. The general features of laser detection and the operational aspects of the examination of physical evidence for laser fingerprint detection are enumerated in the initial sections. The literature review is divided into various pretreatment approaches. Cited studies prior to 1981 are primarily concerned with the demonstration of the viability of laser fingerprint detection, whereas work post-1981 addresses issues of compatibility with the traditional methods of fingerprint development, examination of difficult surfaces, and the routine implementation of laser detection by law enforcement agencies. Related topics of research, review articles, conference reports, case examinations, the research support climate, and future trends are also briefly addressed. Copyright © 1989 Central Police University.

  16. L-carnitine protects against testicular dysfunction caused by gamma irradiation in mice.

    Science.gov (United States)

    Ahmed, Mohamed Mohamed; Ibrahim, Zein Shaban; Alkafafy, Mohamed; El-Shazly, Samir Ahmed

    2014-07-01

    This study was conducted on mice to evaluate the radioprotective role of L-carnitine against γ-ray irradiation-induced testicular damage. Adult male mice were exposed to whole body irradiation at a total dose of 1 Gy. Radiation exposure was continued 24 h a day (0.1 Gy/day) throughout the 10 days exposure period either in the absence and/or presence of L-carnitine at an i.p. dose of 10 mg/kg body weight/day. Results revealed that γ-rays irradiation suppressed the expression of ABP and CYP450SCC mRNA, whereas treatment with L-carnitine prior and throughout γ-rays irradiation exposure inhibited this suppression. Treatment with γ-ray irradiation or L-carnitine down-regulated expression of aromatase mRNA. With combined treatment, L-carnitine significantly normalized aromatase expression. γ-Ray irradiation up-regulated expression of FasL and Cyclin D2 mRNA, while L-carnitine inhibited these up-regulations. Results also showed that γ-ray-irradiation up-regulated TNF-α, IL1-β and IFN-γ mRNA expressions compared to either controls or the L-carnitine treated group. Moreover, γ-irradiation greatly reduced serum testosterone levels, while L-carnitine, either alone or in combination with irradiation, significantly increased serum testosterone levels compared to controls. In addition, γ-irradiation induced high levels of sperm abnormalities (43%) which were decreased to 12% in the presence of L-carnitine. In parallel with these findings, histological examination showed that γ-irradiation induced severe tubular degenerative changes, which were reduced by L-carnitine pre-treatment. These results clarified the immunostimulatory effects of L-carnitine and its radioprotective role against testicular injury. Copyright © 2014 Elsevier GmbH. All rights reserved.

  17. Immune Cell Activation and Co-X-irradiation Effect of Eleutherococcus senticosus Maxim Root

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyoung Cheol [Chonbuk National University, Jeonju (Korea, Republic of); Park, Jeong Seob [Iksan National College, Iksan (Korea, Republic of); Choi, Dong Seong [Woosuk University, Samrye (Korea, Republic of)

    2007-09-15

    Purpose: This study was performed to investigate the effects of immune cell activation and the antitumor effect for the combination of treatment with X-irradiation and Eleutherococcus senticosus Maxim Root (ESMR) on mouse tumor cells. Materials and Methods: ESMR (250g) was extracted with 80% methanol, concentrated under decompression and lyophilized. To determine whether ESMR is able to activate the immune cells or not, the proliferation of splenocytes in vitro and the number of B cells and T cells in splenic lymphocytes in ESMR-pretreated mice were evaluated. X-irradiation was given to the mouse fibrosarcoma tumor cells (FSa II) by 250 kv X-irradiation machine. The cytotoxicity of ESMR was evaluated from its ability to reduce the clonogenecity of FSa II cells. In X-irradiation alone group, each 2, 4, 6 and 8 Gy was given to FSa II cells. In X-irradiation with ESMR group, 0.2 mg/ml of ESMR was exposed to FSa II cells for 1 hour before X-irradiation. Results: The proliferation of cultured mouse splenocytes and thymocytes were enhanced by the addition of ESMR in vitro. The number of B cells and T cells in mouse splenic lymphocytes was significantly increased in ESMR pretreated mice in vivo. In FSa II cells that received a combination of 0.2 mg/ml of ESMR with X-irradiation exposure, the survival fraction with a dose of 2, 4 and 6 Gy was 0.39{+-}0.005, 0.22{+-}0.005 and 0.06{+-}0.007, respectively. For FSa II cells treated with X-irradiation alone, the survival fraction with a dose of 2, 4 and 6 Gy was 0.76{+-}0.02, 0.47{+-}0.008 and 0.37{+-}0.01. The difference in the survival fraction of the mouse FSa II cells treated with and without ESMR was statistically significant (p<0.05). Conclusion: Treatment with ESMR increased cell viability of mouse splenocytes in vitro and especially the subpopulation of B cells and T cells in splenocytes in ESMR-pretreated mice. However, treatment with ESMR did not increase the level of Th and Tc subpopulations in the thymocytes

  18. Waste Separations and Pretreatment Workshop report

    Energy Technology Data Exchange (ETDEWEB)

    Cruse, J.M. [Westinghouse Hanford Co., Richland, WA (United States); Harrington, R.A. [Kaiser Engineers Hanford Co., Richland, WA (United States); Quadrel, M.J. [Battelle Pacific Northwest Lab., Richland, WA (United States)

    1994-01-01

    This document provides the minutes from the Waste Separations and Pretreatment Workshop sponsored by the Underground Storage Tank-Integrated Demonstration in Salt Lake City, Utah, February 3--5, 1993. The Efficient Separations and Processing-Integrated Program and the Hanford Site Tank Waste Remediation System were joint participants. This document provides the detailed minutes, including responses to questions asked, an attendance list, reproductions of the workshop presentations, and a revised chart showing technology development activities.

  19. SEM analysis of weathered grains: Pretreatment effects

    Science.gov (United States)

    Cremeens, D. L.; Darmody, R. G.; Jansen, I. J.

    1987-05-01

    Fresh microcline, albite, and almandine, along with soil grains, were treated with various traditional pretreatments prior to observation with scanning electron microscopy (SEM). The grains were observed with SEM and given ratings for each of several surface properties to determine which pretreatments produced clean surfaces on soil grains without laboratory-induced damage on the fresh mineral grains. Gentle overnight shaking in 2% sodium bicarbonate at pH 9.5 produced the most effective cleaning of soil grains with the least amount of induced damage to fresh mineral samples. This pretreatment was equivalent to that given the control samples (shaken overnight in distilled water) for observations of etch pits on fresh mineral samples within a 25% equivalence (or negligible difference) interval. Ultrasonification, hydrogen peroxide, and boiling hydrochloric acid caused the most damage to mineral samples, mainly in the form of 0.5-μm etch pits. Boiling hydrochloric acid, boiling nitric acid, and stannous chloride resulted in increased coated surfaces on soil grains.

  20. Safety of irradiated foods

    Energy Technology Data Exchange (ETDEWEB)

    Iwahara, Shigeo (Foods Medicines Safety Center (Japan)); Kobayashi, Kazuo

    1983-01-01

    The safety of 7 irradiated foods (potato, onion, rice, wheat, vienna sausage, fish paste and mandarine orange), in terms of 2-year long-term toxic effect, reproductive physiology and possible teratogenesis, was studied using 3 generations of rats, mice and monkeys. The genetic toxicity was studied by means of various mutagenicity tests. The details of the studies conducted by the authors to date and some overseas data were reported. The available data showed no toxic effect.

  1. Hydrothermal pretreatment of palm oil empty fruit bunch

    Science.gov (United States)

    Simanungkalit, Sabar Pangihutan; Mansur, Dieni; Nurhakim, Boby; Agustin, Astrid; Rinaldi, Nino; Muryanto, Fitriady, Muhammad Ariffudin

    2017-01-01

    Hydrothermal pretreatment methods in 2nd generation bioethanol production more profitable to be developed, since the conventional pretreatment, by using acids or alkalis, is associated with the serious economic and environmental constraints. The current studies investigate hydrothermal pretreatment of palm oil empty fruit bunch (EFB) in a batch tube reactor system with temperature and time range from 160 to 240 C and 15 to 30 min, respectively. The EFB were grinded and separated into 3 different particles sizes i.e. 10 mesh, 18 mesh and 40 mesh, prior to hydrothermal pretreatment. Solid yield and pH of the treated EFB slurries changed over treatment severities. The chemical composition of EFB was greatly affected by the hydrothermal pretreatment especially hemicellulose which decreased at higher severity factor as determined by HPLC. Both partial removal of hemicellulose and migration of lignin during hydrothermal pretreatment caused negatively affect for enzymatic hydrolysis. This studies provided important factors for maximizing hydrothermal pretreatment of EFB.

  2. Pretreatment of the macroalgae Chaetomorpha linum for the production of bioethanol–Comparison of five pretreatment technologies

    DEFF Research Database (Denmark)

    Thomsen, Sune Tjalfe

    2013-01-01

    A qualified estimate for pretreatment of the macroalgae Chaetomorpha linum for ethanol production was given, based on the experience of pretreatment of land-based biomass. C. linum was subjected to hydrothermal pretreatment (HTT), wet oxidation (WO), steam explosion (STEX), plasma...... yield of 57. g ethanol/100. g glucan. A 64% higher ethanol yield, based on raw material, was reached after pretreatment with WO and BM compared with unpretreated C. linum, however 50% of the biomass was lost during WO. Results indicated that the right combination of pretreatment and marine macroalgae...

  3. ATF Neutron Irradiation Program Irradiation Vehicle Design Concepts

    Energy Technology Data Exchange (ETDEWEB)

    Geringer, J. W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Howard, Richard H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Cetiner, N. O. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Petrie, Christian M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; Smith, Kurt R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division; McDuffee, J. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Materials Science and Technology Division

    2016-03-01

    The Japan Atomic Energy Agency (JAEA) under the Civil Nuclear Energy Working Group (CNWG) is engaged in a cooperative research effort with the U.S. Department of Energy (DOE) to explore issues related to nuclear energy, including research on accident-tolerant fuels and materials for use in light water reactors. This work develops a draft technical plan for a neutron irradiation program on the candidate accident-tolerant fuel cladding materials and elements using the High Flux Isotope Reactor (HFIR). The research program requires the design of a detailed experiment, development of test vehicles, irradiation of test specimens, possible post irradiation examination and characterization of irradiated materials and the shipment of irradiated materials to Japan. This report discusses the conceptual design, the development and irradiation of the test vehicles.

  4. Lethal and Sublethal Effects of Glyphosate (Roundup® Active to Embryos of Colombian Anurans

    Directory of Open Access Journals (Sweden)

    Teófila María Triana Velásquez

    2013-05-01

    Full Text Available Glyphosate is an herbicide widely used in agriculture, which may affect non-target species. The aim of this study was to determine the lethal (Median lethal concentration - LC50 and sublethal effects (changes on body size and development of glyphosate (Roundup® Active to embryos of four anuran species, exposed during 96 hours under laboratory and microcosm tests. Under laboratory conditions, Engystomops pustulosus was the most tolerant species (LC50 = 3033,18 μg a.e./L and Rhinella marina was the most sensitive (LC50 = 1421,46 μg a.e./L, which also showed a delayed development and significantly reduced body size. The other species had an intermediate LC50 (Rhinella humboldti = 2899,54 μg a.e./L; Hypsiboas crepitans = 2151,88 μg a.e./L. In all cases, the laboratory LC50 was lower than the concentration used in field (5392,92 μg a.e./L, indicating a high toxic effect. In the microcosm tests, embryos of E. pustulosus were the most tolerant (LC50 = 19,41 kg a.e./ha, while R. humboldti were the most sensitive (LC50 = 10,61 kg a.e./ha. In this case, all four study species had a higher LC50 than the concentration sprayed in field (3,69 kg a.e./ ha, so a lower lethal effect, and there were no significant differences in body size and development. This result shows that the glyphosate, as the commercial presentation Roundup® Active, produce a moderate mortality on anuran embryos.EFECTOS LETALES Y SUBLETALES DEL GLIFOSATO (ROUNDUP® ACTIVO EN EMBRIONES DE ANUROS COLOMBIANOS.El glifosato es un herbicida usado en la agricultura que puede afectar especies no blanco. El objetivo del trabajo fue determinar los efectos letales (concentración letal media - CL50 y subletales (cambios en el tamaño corporal y desarrollo del glifosato (Roundup® Activo sobre embriones de cuatro especies de anuros expuestos durante 96 horas en pruebas de laboratorio y microcosmos. En laboratorio, la especie más tolerante fue Engystomops pustulosus (CL50 = 3033,18 μg a

  5. Impact of gamma-irradiation on some mass transfer driven operations in food processing

    Energy Technology Data Exchange (ETDEWEB)

    Rastogi, N.K. [Department of Food Engineering, Central Food Technological Research Institute, Mysore 570 020 (India)]. E-mail: nkrastogi@cftri.com

    2005-08-01

    The effect of gamma-irradiation pretreatment on some mass transfer driven operations such as dehydration, osmotic dehydration and rehydration, commonly used in food processing, was studied. Applied irradiation up to 12.0 kGy resulted in decrease in hardness of the samples, as indicated by texture analysis. The effective diffusion coefficients of water and solute determined for dehydration, osmotic dehydration as well as for rehydration using a Fickian diffusion model. The effective diffusion coefficients for water (in case of osmotic dehydration and dehydration) and solid diffusion (in case of osmotic dehydration) were found to increase exponentially with doses of gamma-irradiation (G) according to an equation of the form D=A exp(-B/G), where A and B are constants. Microstructures of irradiated-carrot samples revealed that the exposure of carrot to gamma irradiation resulted in the breakage of cell wall structure, thereby causing softening of irradiated samples and facilitating mass transfer during dehydration and osmotic dehydration. The rehydration characteristics showed that gamma-irradiated sample did not absorb as much water as control, probably due to loss of cell integrity.

  6. Impact of gamma-irradiation on some mass transfer driven operations in food processing

    Science.gov (United States)

    Rastogi, N. K.

    2005-08-01

    The effect of gamma-irradiation pretreatment on some mass transfer driven operations such as dehydration, osmotic dehydration and rehydration, commonly used in food processing, was studied. Applied irradiation up to 12.0 kGy resulted in decrease in hardness of the samples, as indicated by texture analysis. The effective diffusion coefficients of water and solute determined for dehydration, osmotic dehydration as well as for rehydration using a Fickian diffusion model. The effective diffusion coefficients for water (in case of osmotic dehydration and dehydration) and solid diffusion (in case of osmotic dehydration) were found to increase exponentially with doses of gamma-irradiation ( G) according to an equation of the form D= A exp(- B/ G), where A and B are constants. Microstructures of irradiated-carrot samples revealed that the exposure of carrot to gamma irradiation resulted in the breakage of cell wall structure, thereby causing softening of irradiated samples and facilitating mass transfer during dehydration and osmotic dehydration. The rehydration characteristics showed that gamma-irradiated sample did not absorb as much water as control, probably due to loss of cell integrity.

  7. Induced disease resistance of satsuma mandarings against penicillium digitatum by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Rae Dong [Dept. of Applied Biology, Institute of Environmentally Friendly Agriculture, Chonnam National University, Gwangju (Korea, Republic of)

    2017-06-15

    Gamma irradiation, which is a type of ionizing radiation, can be used as a fruit inducible factor. In the present study, the effects of gamma irradiation on the resistance of mandarin fruits against Penicillium digitatum, the causal agent of postharvest green mold disease, were investigated. Pretreatment of a low dose of gamma irradiation effectively reduced the disease incidence and lesion diameter of mandarin fruits inoculated with P. digatatum during storage for 14 d. Interestingly, exposed to 400 Gy of gamma irradiation significantly maintained firmness and stimulated the synthesis of defense-related enzymes, (e.g., β-1,3-glucanase, phenylalanine, peroxidase, and polyphenol oxidase) and pathogenesis-related (PR) genes (e.g., PR-1 and PR-2). Therefore, the gamma irradiation-induced resistance against P. digatatum involves both changes of phenolic compounds and the induction of expression of defense-related genes. In addition, scanning electron microscopy analysis revealed that induced disease resistance by gamma irradiation signifcantly inhibits the growth of P. digatatum in mandarin fruits. These results suggest that the exposure of gamma irradiation is a potential methods for inducing the disease resistance of fruit to postharvest fungal pathogens and for extending the postharvest life of mandarin fruit.

  8. Long-term anaerobic digestion of microalgae grown in HRAP for wastewater treatment. Effect of microwave pretreatment.

    Science.gov (United States)

    Passos, Fabiana; Hernández-Mariné, Mariona; García, Joan; Ferrer, Ivet

    2014-02-01

    This paper describes the anaerobic digestion of microalgal biomass from high rate ponds in continuous anaerobic reactors for biogas production. With hydraulic retention times (HRT) of 15 and 20 days, the volatile solids (VS) removal did not exceed 30%, and the methane production rate ranged between 0.12 and 0.14 L CH4/L day. To improve process performance, microwave irradiation at 900 W for 3 min (specific energy ∼70,000 kJ/kg VS) was applied as a pretreatment step. The VS removal increased to 40 and 45% at 15 and 20 days HRT, respectively. Consequently, the methane production rate increased to 0.16 and 0.20 L CH4/L day at 15 and 20 days HRT, respectively. Microscopic analysis confirmed cell wall damage, although generally without lysis, after irradiating microalgal biomass. However, the energy consumption was much higher than the extra energy production of the process. Indeed, microalgal biomass should not only be thickened but also dewatered if microwave irradiation was to be applied as a pretreatment to anaerobic digestion for biogas production. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Adhesion between glass fiber posts and resin cement: evaluation of bond strength after various pre-treatments.

    Science.gov (United States)

    Sipahi, Cumhur; Piskin, Bulent; Akin, Gulsah E; Bektas, Ozden Ozel; Akin, Hakan

    2014-10-01

    To evaluate surface roughness and bond strength of glass fiber posts to a resin cement after various surface treatments. Sixty individually formed glass fiber posts with a diameter of 1.5 mm and a length of 20 mm were used for this study. They were randomly assigned to six groups of pre-treatment (n = 10/group): Group C, untreated (control); Group SB, sandblasted; Group SC, silica coated; Group HF, hydrofluoric acid-etched; Group N, Nd:YAG laser irradiated; Group E, Er:YAG laser irradiated. Surface roughness of the posts was measured before and after pre-treatment. The posts were then bonded to resin cement and tensile bond strengths were determined in a universal testing machine. For statistical analysis, two-way ANOVA and post-hoc comparison tests (α = 0.05) were performed. The highest bond strength value was observed in group HF, followed by group SC. There was a statistically significant difference in bond strength between group C and groups HF, SC and E (p Posts of group SB and group N showed the highest surface roughness. The findings of the present study reveal that hydrofluoric acid-etching, silica coating and Er:YAG laser irradiation provided a significant increase in bond strength between glass fiber posts and resin cement.

  10. Evaluation of surface roughness and bond strength of quartz fiber posts after various pre-treatments.

    Science.gov (United States)

    Akin, Gulsah E; Akin, Hakan; Sipahi, Cumhur; Piskin, Bulent; Kirmali, Omer

    2014-11-01

    Debonding at the post-adhesive interface is a major problem for quartz fiber posts. The objective of this study was to evaluate surface roughness and bond strength of quartz fiber posts after various surface treatments. Sixty-six quartz fiber posts were randomly divided into six experimental groups (n = 11) including group C, untreated (control); group SB, sandblasted; group SC, silica coated; group HF, hydrofluoric acid-etched; group N, Nd:YAG laser irradiated; group E, Er:YAG laser irradiated. Surface roughness of the posts was measured before and after pre-treatment. They were then bonded to resin cement and tensile bond strength was determined in a universal testing machine. Furthermore, two-way ANOVA and post hoc comparison tests (α = 0.05) were performed on all data. The highest mean force value was observed in group SB and followed by group E. Tukey's HSD test showed that there was no statistical difference between group SB and group E (p = 0.673). The highest mean roughness value was observed in group SB and a significant difference was found between group SB and all other groups (p quartz fiber posts and resin cement. Sandblasting or Er:YAG laser-irradiation of the surface of the quartz fiber post before cementation is recommended for increasing retention.

  11. Chloride and sulphate toxicity to Hydropsyche exocellata (Trichoptera, Hydropsychidae): Exploring intraspecific variation and sub-lethal endpoints

    Energy Technology Data Exchange (ETDEWEB)

    Sala, Miquel [Centre Tecnològic Forestal de Catalunya - CTFC, Solsona, Catalunya (Spain); Faria, Melissa [CESAM, Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro (Portugal); Sarasúa, Ignacio [Technische Universität München, Munich, Bayern (Germany); Barata, Carlos [Institute of Environmental Assessment and Water Research (IDAEA-CSIC), Barcelona (Spain); Bonada, Núria [Grup de Recerca Freshwater Ecology and Management (FEM), Departament d' Ecologia, Facultat de Biologia, Universitat de Barcelona (UB), Diagonal 643, 08028 Barcelona, Catalonia (Spain); Grup de Recerca Freshwater Ecology and Management (FEM), Departament d' Ecologia, Facultat de Biologia, Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona - UB, Diagonal 643, 08028 Barcelona, Catalonia (Spain); Brucet, Sandra [Aquatic Ecology Group, BETA Tecnio Centre, University of Vic - Central University of Catalonia, Vic, Catalonia (Spain); Catalan Institution for Research and Advanced Studies, ICREA, Barcelona 08010 (Spain); Llenas, Laia; Ponsá, Sergio [Aquatic Ecology Group, BETA Tecnio Centre, University of Vic - Central University of Catalonia, Vic, Catalonia (Spain); Prat, Narcís [Grup de Recerca Freshwater Ecology and Management (FEM), Departament d' Ecologia, Facultat de Biologia, Universitat de Barcelona (UB), Diagonal 643, 08028 Barcelona, Catalonia (Spain); Soares, Amadeu M.V.M. [CESAM, Departamento de Biologia, Universidade de Aveiro, 3810-193 Aveiro (Portugal); and others

    2016-10-01

    The rivers and streams of the world are becoming saltier due to human activities. In spite of the potential damage that salt pollution can cause on freshwater ecosystems, this is an issue that is currently poorly managed. Here we explored intraspecific differences in the sensitivity of freshwater fauna to two major ions (Cl{sup −} and SO{sub 4}{sup 2−}) using the net-spinning caddisfly Hydropsyche exocellata Dufour 1841 (Trichoptera, Hydropsychidae) as a model organism. We exposed H. exocellata to saline solutions (reaching a conductivity of 2.5 mS cm{sup −1}) with Cl{sup −}:SO{sub 4}{sup 2−} ratios similar to those occurring in effluents coming from the meat, mining and paper industries, which release dissolved salts to rivers and streams in Spain. We used two different populations, coming from low and high conductivity streams. To assess toxicity, we measured sub-lethal endpoints: locomotion, symmetry of the food-capturing nets and oxidative stress biomarkers. According to biomarkers and net building, the population historically exposed to lower conductivities (B10) showed higher levels of stress than the population historically exposed to higher conductivities (L102). However, the differences between populations were not strong. For example, net symmetry was lower in the B10 than in the L102 only 48 h after treatment was applied, and biomarkers showed a variety of responses, with no discernable pattern. Also, treatment effects were rather weak, i.e. only some endpoints, and in most cases only in the B10 population, showed a significant response to treatment. The lack of consistent differences between populations and treatments could be related to the high salt tolerance of H. exocellata, since both populations were collected from streams with relatively high conductivities. The sub-lethal effects tested in this study can offer an interesting and promising tool to monitor freshwater salinization by combining physiological and behavioural bioindicators

  12. Sublethal amounts of Origanum vulgare L. essential oil and carvacrol cause injury and changes in membrane fatty acid of Salmonella Typhimurium cultivated in a meat broth.

    Science.gov (United States)

    Luz, Isabelle da Silva; de Melo, Adma Nadja Ferreira; Bezerra, Taliana Kênia Alves; Madruga, Marta Suely; Magnani, Marciane; de Souza, Evandro Leite

    2014-05-01

    This study aimed to evaluate whether sublethal concentrations of the essential oil of Origanum vulgare L. (OVEO) and its major compound carvacrol (CAR) cause injury to the cell membrane and outer membrane of Salmonella enterica serovar Typhimurium ATCC 14028 grown in a meat broth and to assess the effect of these substances on membrane fatty acid (FA) composition. Exposure of Salmonella Typhimurium ATCC 14028 to sublethal concentrations of OVEO or CAR caused damage to the cytoplasmic membrane and outer membrane. OVEO- and CAR-treated cells showed lower amounts of saturated FA than nontreated cells. Changes in membrane FA composition were mainly related to an increase of C16:1ω7c, C16:1ω7t, and C18:2ω6c, and to a decrease of C16:0, C17:0 cyclo, and C19:0 cyclo. These results indicate that exposure to sublethal concentrations of OVEO or CAR caused sublethal injury Salmonella Typhimurium ATCC 14028 and suggest that an adaptive response to these stresses is related to increased synthesis of unsaturated FA and cis-trans isomerization.

  13. Sublethal effects of chlorantraniliprole on development, reproduction and vitellogenin gene (CsVg) expression in the rice stem borer, Chilo suppressalis.

    Science.gov (United States)

    Huang, Li; Lu, Mingxing; Han, Guangjie; Du, Yuzhou; Wang, Jianjun

    2016-12-01

    The rice stem borer, Chilo suppressalis (Walker), is one of the most damaging rice pests in the world. The sublethal effects of chlorantraniliprole on development,reproduction and mRNA expression levels of vitellogenin gene (CsVg) in C. suppressalis were investigated. Exposure of third-instar larvae to sublethal concentrations of chlorantraniliprole (LC10 and LC30 ) significantly extended larval duration, lowered the mean weight of male pupae and shortened male adult longevity. Pupal duration was significantly prolonged and the mean weight of female pupae was significantly lowered in the LC30 treatment group. While there were no significant sublethal effects on either the adult emergence rate or the egg hatch, the pupation rates in the LC10 treatment group (41.30%) and in the LC30 treatment group (23.98%) were significantly lower than the pupation rate of the control (71.86%), and LC10 and LC30 chlorantraniliprole significantly reduced fecundity, by 32.18 and 52.94% respectively. Furthermore, the expression levels of CsVg mRNA after exposure to LC10 and LC30 chlorantraniliprole significantly decreased, by 42.52 and 47.84% respectively, in 12-h-old female adults. Sublethal concentrations of chlorantraniliprole adversely affect the development and reproduction of C. suppressalis. The downregulation of CsVg by chlorantraniliprole might have negative impacts on the fecundity of C. suppressalis. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. Physiochemical Characterization of Lignocellulosic Biomass Dissolution by Flowthrough Pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Lishi; Pu, Yunqiao; Bowden, Mark; Ragauskas, Arthur J.; Yang, Bin

    2016-01-04

    Comprehensive understanding of biomass solubilization chemistry in aqueous pretreatment such as water-only and dilute acid flowthrough pretreatment is of fundamental importance to achieve the goal of valorizing biomass to fermentable sugars and lignin for biofuels production. In this study, poplar wood was flowthrough pretreated by water-only or 0.05% (w/w) sulfuric acid at different temperatures (220-270 °C), flow rate (25 mL/min), and reaction times (8-90 min), resulting in significant disruption of the lignocellulosic biomass. Ion chromatography (IC), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) analysis, and solid state cross-polarization/magic angle spinning (CP/MAS) 13C nuclear magnetic resonance (NMR) spectroscopy were applied to characterize the pretreated biomass whole slurries in order to reveal depolymerization as well as solubilization mechanism and identify unique dissolution structural features during these pretreatments. Results showed temperature-dependent cellulose decrystallization in flowthrough pretreatment. Crystalline cellulose was completely disrupted, and mostly converted to amorphous cellulose and oligomers by water-only operation at 270 °C for 10 min and by 0.05 wt % H2SO4 flowthrough pretreatment at 220 °C for 12 min. Flowthrough pretreatment with 0.05% (w/w) H2SO4 led to a greater disruption of structures in pretreated poplar at a lower temperature compared to water-only pretreatment.

  15. Craniospinal irradiation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Scarlatescu, Ioana, E-mail: scarlatescuioana@gmail.com; Avram, Calin N. [Faculty of Physics, West University of Timisoara, Bd. V. Parvan 4, 300223 Timisoara (Romania); Virag, Vasile [County Hospital “Gavril Curteanu” - Oradea (Romania)

    2015-12-07

    In this paper we present one treatment plan for irradiation cases which involve a complex technique with multiple beams, using the 3D conformational technique. As the main purpose of radiotherapy is to administrate a precise dose into the tumor volume and protect as much as possible all the healthy tissues around it, for a case diagnosed with a primitive neuro ectoderm tumor, we have developed a new treatment plan, by controlling one of the two adjacent fields used at spinal field, in a way that avoids the fields superposition. Therefore, the risk of overdose is reduced by eliminating the field divergence.

  16. Energy consumption modeling during dairy sewage pretreatment

    Science.gov (United States)

    Dąbrowski, Wojciech; Żyłka, Radosław; Malinowski, Paweł; Boruszko, Dariusz

    2017-11-01

    The research was conducted in a dairy WWTP located in north-eastern Poland with the average flow of 546 m3d-1 and PE 11500 in 2016. Energy consumption was measured with the help of Lumel 3-phase network parameter transducers installed within the plant. The modeling was conducted based on the quantity and quality of raw sewage, after its screening, averaging and dissolved air flotation. The following parameters were determined: BOD5, COD. N-total and P-total. During the research period. 15 measurement series were carried out. Pollution loads removed in primary treatment varied from 167.0 to 803.5 kgO2d-1 and 1205.9 to 10032 kgO2d-1 for BOD5 and COD respectively. The energy consumption share during dairy pretreatment in relation to the total energy consumption was in the range from 13.8 to 28.5% with the mean value of 18.7% during the research period. Energy consumption indicators relating to removed pollution loads for primary treatment were established with the mean values of 0.74 and 0.83 kWhkg-1d-1 for BOD5 and COD respectively. An attempt was made to determine the influence of raw sewage characteristics and pretreatment efficiency on energy consumption of the object. A model of energy consumption during pretreatment was estimated according to the experimental data obtained in the research period. It was modeled using the linear regression model and principal component analysis.

  17. Rheological evaluation of pretreated cladding removal waste

    Energy Technology Data Exchange (ETDEWEB)

    McCarthy, D.; Chan, M.K.C.; Lokken, R.O.

    1986-01-01

    Cladding removal waste (CRW) contains concentrations of transuranic (TRU) elements in the 80 to 350 nCi/g range. This waste will require pretreatment before it can be disposed of as glass or grout at Hanford. The CRW will be pretreated with a rare earth strike and solids removal by centrifugation to segregate the TRU fraction from the non-TRU fraction of the waste. The centrifuge centrate will be neutralized with sodium hydroxide. This neutralized cladding removal waste (NCRW) is expected to be suitable for grouting. The TRU solids removed by centrifugation will be vitrified. The goal of the Rheological Evaluation of Pretreated Cladding Removal Waste Program was to evaluate those rheological and transport properties critical to assuring successful handling of the NCRW and TRU solids streams and to demonstrate transfers in a semi-prototypic pumping environment. This goal was achieved by a combination of laboratory and pilot-scale evaluations. The results obtained during these evaluations were correlated with classical rheological models and scaled-up to predict the performance that is likely to occur in the full-scale system. The Program used simulated NCRW and TRU solid slurries. Rockwell Hanford Operations (Rockwell) provided 150 gallons of simulated CRW and 5 gallons of simulated TRU solid slurry. The simulated CRW was neutralized by Pacific Northwest Laboratory (PNL). The physical and rheological properties of the NCRW and TRU solid slurries were evaluated in the laboratory. The properties displayed by NCRW allowed it to be classified as a pseudoplastic or yield-pseudoplastic non-Newtonian fluid. The TRU solids slurry contained very few solids. This slurry exhibited the properties associated with a pseudoplastic non-Newtonian fluid.

  18. Plasma-Assisted Pretreatment of Wheat Straw

    DEFF Research Database (Denmark)

    Schultz-Jensen, Nadja; Leipold, Frank; Bindslev, Henrik

    2011-01-01

    and milled particle size (the extent to which the wheat straw was milled) were investigated and optimized. The developed methodology offered the advantage of a simple and relatively fast (0.5–2 h) pretreatment allowing a dry matter concentration of 45–60%. FTIR measurements did not suggest any structural...... straw with desired lignin content because of the online analysis. The O3 consumption of wheat straw and its polymeric components, i.e., cellulose, hemicellulose, and lignin, as well as a mixture of these, dry as well as with 50% water, were studied. Furthermore, the process parameters dry matter content...

  19. Pretreatment and enzymatic hydrolysis of lignocellulosic biomass

    Science.gov (United States)

    Corredor, Deisy Y.

    The performance of soybean hulls and forage sorghum as feedstocks for ethanol production was studied. The main goal of this research was to increase fermentable sugars' yield through high-efficiency pretreatment technology. Soybean hulls are a potential feedstock for production of bio-ethanol due to their high carbohydrate content (≈50%) of nearly 37% cellulose. Soybean hulls could be the ideal feedstock for fuel ethanol production, because they are abundant and require no special harvesting and additional transportation costs as they are already in the plant. Dilute acid and modified steam-explosion were used as pretreatment technologies to increase fermentable sugars yields. Effects of reaction time, temperature, acid concentration and type of acid on hydrolysis of hemicellulose in soybean hulls and total sugar yields were studied. Optimum pretreatment parameters and enzymatic hydrolysis conditions for converting soybean hulls into fermentable sugars were identified. The combination of acid (H2SO4, 2% w/v) and steam (140°C, 30 min) efficiently solubilized the hemicellulose, giving a pentose yield of 96%. Sorghum is a tropical grass grown primarily in semiarid and dry parts of the world, especially in areas too dry for corn. The production of sorghum results in about 30 million tons of byproducts mainly composed of cellulose, hemicellulose, and lignin. Forage sorghum such as brown midrib (BMR) sorghum for ethanol production has generated much interest since this trait is characterized genetically by lower lignin concentrations in the plant compared with conventional types. Three varieties of forage sorghum and one variety of regular sorghum were characterized and evaluated as feedstock for fermentable sugar production. Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and X-Ray diffraction were used to determine changes in structure and chemical composition of forage sorghum before and after pretreatment and enzymatic hydrolysis

  20. Corn-milling pretreatment with anhydrous ammonia.

    Science.gov (United States)

    Taylor, Frank; Craig, James C; Kurantz, M J; Singh, Vijay

    2003-02-01

    Exposure to anhydrous ammonia has been suggested as a pretreatment for corn milling. Batches of corn were exposed to ammonia under controlled conditions. The amounts of ammonia absorbed and reacted with the corn were measured. The amounts were not more than are needed as nutritional supplement for yeast fermentation to ethanol. Loosening of the hull was observed qualitatively, and subsequent shearing in a disk mill followed by steeping for 2, 4, 6, or 8 h showed that germ could be recovered at higher yield and after a shorter steeping time compared to untreated control batches. Quality of oil was not affected by treatment with ammonia.

  1. International Developments of Food Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Loaharanu, P. [Head, Food Preservation Section, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Wagramerstr. 5, A-1400, Vienna (Austria)

    1997-12-31

    Food irradiation is increasingly accepted and applied in many countries in the past decade. Through its use, food losses and food-borne diseases can be reduced significantly, and wider trade in many food items can be facilitated. The past five decades have witnessed a positive evolution on food irradiation according to the following: 1940`s: discovery of principles of food irradiation; 1950`s: initiation of research in advanced countries; 1960`s: research and development were intensified in some advanced and developing countries; 1970`s: proof of wholesomeness of irradiated foods; 1980`s: establishment of national regulations; 1990`s: commercialization and international trade. (Author)

  2. Food irradiation and the consumer

    Science.gov (United States)

    A Thomas, P.

    The poster presents a review of research work undertaken on the perception and understanding that consumers have of food irradiation. Food irradiation is not a revolutionary new food processing technique, in fact it is probably one of the most investigated methods presently available. Many countries such as Belgium, France, Denmark, Italy, Spain, the Netherlands and the United States of America permit food irradiation. In Britain it is presently banned although this is currently under review. Awareness of food irradiation by the general public in Britain, although not extensively researched would appear to be increasing, especially in the light of recent media coverage. New quantitative and qualitative work indicates that the general public are concerned about the safety and effectiveness of food irradiation. Research has shown that a large proportion of consumers in Britain, if given the opportunity to purchase irradiated food, would not do so. Further exploration into this response revealed the fact that consumers are confused over what food irradiation is. In addition, there is concern over the detection of irradiated food. The views presented in this paper, of the consumer reaction to irradiated food are of great importance to those involved in the food industry and industries allied to it, which are ultimately dependent on the consumer for their commercial survival.

  3. Sublethal Concentrations of Antibiotics Cause Shift to Anaerobic Metabolism in Listeria monocytogenes and Induce Phenotypes Linked to Antibiotic Tolerance

    DEFF Research Database (Denmark)

    Knudsen, Gitte Maegaard; Fromberg, Arvid; Ng, Yin

    2016-01-01

    The human pathogenic bacterium Listeria monocytogenes is exposed to antibiotics both during clinical treatment and in its saprophytic lifestyle. As one of the keys to successful treatment is continued antibiotic sensitivity, the purpose of this study was to determine if exposure to sublethal...... antibiotic concentrations would affect the bacterial physiology and induce antibiotic tolerance. Transcriptomic analyses demonstrated that each of the four antibiotics tested caused an antibiotic-specific gene expression pattern related to mode-of-action of the particular antibiotic. All four antibiotics...... caused the same changes in expression of several metabolic genes indicating a shift from aerobic to anaerobic metabolism and higher ethanol production. A mutant in the bifunctional acetaldehyde-CoA/alcohol dehydrogenase encoded by Imo1634 did not have altered antibiotic tolerance. However, a mutant...

  4. Exploring sub-lethal effects of exposure to a nucleopolyhedrovirus in the speckled wood (Pararge aegeria) butterfly.

    Science.gov (United States)

    Hesketh, Helen; Gibbs, Melanie; Breuker, Casper J; Van Dyck, Hans; Turner, Emma; Hails, Rosemary S

    2012-01-01

    This study investigated the sub-lethal effects of larval exposure to baculovirus on host life history and wing morphological traits using a model system, the speckled wood butterfly Pararge aegeria (L.) and the virus Autographa californica nucleopolyhedrovirus. Males and females showed similar responses to the viral infection. Infection significantly reduced larval growth rate, whilst an increase in development time allowed the critical mass for pupation to be attained. There was no direct effect of viral infection on the wing morphological traits examined. There was, however, an indirect effect of resisting infection; larvae that took longer to develop had reduced resource investment in adult flight muscle mass. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

  5. Supporting data for comparative proteomic analysis of Listeria monocytogenes ATCC 7644 exposed to a sublethal concentration of nisin

    Directory of Open Access Journals (Sweden)

    Kendi Nishino Miyamoto

    2015-06-01

    Full Text Available Here we provide the LC–MS/MS data from a comparative analysis of Listeria monocytogenes ATCC 7644 treated and non-treated with a sublethal concentration of nisin (10−3 mg/mL. Protein samples were analyzed by multidimensional protein identification technology (MudPIT approach, in an off-line configuration. The raw MS/MS data allowed the detection of 49,591 spectra which resulted in 576 protein identifications. After Scaffold validation, 179 proteins were identified with high confidence. A label-free quantitative analysis based of normalized spectral abundance factor (NSAF was used and 13 proteins were found differentially expressed between nisin-treated and non-treated cells. Gene ontology analysis of differentially expressed proteins revealed that most of them are correlated to metabolic process, oxidative stress response mechanisms and molecular binding. A detailed analysis and discussion of these data may be found in Miyamoto et al. [1].

  6. Experimental assessment of the effects of sublethal salinities on growth performance and stress in cultured tra catfish (Pangasianodon hypophthalmus).

    Science.gov (United States)

    Nguyen, Phuc Trong Hong; Do, Huong Thi Thanh; Mather, Peter B; Hurwood, David A

    2014-12-01

    The effects of a range of different sublethal salinities were assessed on physiological processes and growth performance in the freshwater 'tra' catfish (Pangasianodon hypophthalmus) juveniles over an 8-week experiment. Fish were distributed randomly among 6 salinity treatments [2, 6, 10, 14 and 18 g/L of salinity and a control (0 g/L)] with a subsequent 13-day period of acclimation. Low salinity conditions from 2 to 10 g/L provided optimal conditions with high survival and good growth performance, while 0 g/L and salinities >14 g/L gave poorer survival rates (p Tra catfish do not appear to be efficient osmoregulators when salinity levels exceed 10 g/L, and at raised salinity levels, growth performance is compromised. In general, results of this study confirm that providing culture environments in the Mekong River Basin do not exceed 10 g/L salinity and that cultured tra catfish can continue to perform well.

  7. Sublethal exposure to crude oil during embryonic development alters cardiac morphology and reduces aerobic capacity in adult fish.

    Science.gov (United States)

    Hicken, Corinne E; Linbo, Tiffany L; Baldwin, David H; Willis, Maryjean L; Myers, Mark S; Holland, Larry; Larsen, Marie; Stekoll, Michael S; Rice, Stanley D; Collier, Tracy K; Scholz, Nathaniel L; Incardona, John P

    2011-04-26

    Exposure to high concentrations of crude oil produces a lethal syndrome of heart failure in fish embryos. Mortality is caused by cardiotoxic polycyclic aromatic hydrocarbons (PAHs), ubiquitous components of petroleum. Here, we show that transient embryonic exposure to very low concentrations of oil causes toxicity that is sublethal, delayed, and not counteracted by the protective effects of cytochrome P450 induction. Nearly a year after embryonic oil exposure, adult zebrafish showed subtle changes in heart shape and a significant reduction in swimming performance, indicative of reduced cardiac output. These delayed physiological impacts on cardiovascular performance at later life stages provide a potential mechanism linking reduced individual survival to population-level ecosystem responses of fish species to chronic, low-level oil pollution.

  8. Acute exposure to a sublethal dose of imidacloprid and coumaphos enhances olfactory learning and memory in the honeybee Apis mellifera.

    Science.gov (United States)

    Williamson, Sally M; Baker, Daniel D; Wright, Geraldine A

    2013-06-01

    The decline of honeybees and other pollinating insects is a current cause for concern. A major factor implicated in their decline is exposure to agricultural chemicals, in particular the neonicotinoid insecticides such as imidacloprid. Honeybees are also subjected to additional chemical exposure when beekeepers treat hives with acaricides to combat the mite Varroa destructor. Here, we assess the effects of acute sublethal doses of the neonicotinoid imidacloprid, and the organophosphate acaricide coumaphos, on honey bee learning and memory. Imidacloprid had little effect on performance in a six-trial olfactory conditioning assay, while coumaphos caused a modest impairment. We report a surprising lack of additive adverse effects when both compounds were administered simultaneously, which instead produced a modest improvement in learning and memory.

  9. Sublethal responses of the common mussel (Mytilus galloprovincialis) exposed to sodium hypochlorite and Mexel432 used as antifoulants.

    Science.gov (United States)

    López-Galindo, Cristina; Vargas-Chacoff, Luis; Nebot, Enrique; Casanueva, José F; Rubio, Daniel; Mancera, Juan M; Solé, Montserrat

    2010-07-01

    The sublethal effects of two antifoulants currently used in power plant cooling systems were assessed in the common mussel Mytilus galloprovincialis. The concentrations of sodium hypochlorite (NaClO) and an alkyl amine surfactant (Mexel432) assayed, were within the range of those currently discharged by power plants into receiving waters. Enzymatic activities and oxidative stress responses were measured in digestive gland and gill of mussels after 1, 3, 7 and 14 days of exposure, as well as histopathology in gill tissue. Both antifoulants caused a pathological response in gills and the activities of the enzymes glutathione S-transferase, catalase, acetylcholinesterase and the lipid peroxidation levels were also affected. Exposure to NaClO caused a greater toxicological response than Mexel432. In both treatments, gills appeared to be the most affected tissue, although Mexel432 also significantly affected digestive gland parameters. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  10. Supporting data for comparative proteomic analysis of Listeria monocytogenes ATCC 7644 exposed to a sublethal concentration of nisin

    Science.gov (United States)

    Miyamoto, Kendi Nishino; Mariante Monteiro, Karina; da Silva Caumo, Karin; Rodrigues Lorenzatto, Karina; Bunselmeyer Ferreira, Henrique; Brandelli, Adriano

    2015-01-01

    Here we provide the LC–MS/MS data from a comparative analysis of Listeria monocytogenes ATCC 7644 treated and non-treated with a sublethal concentration of nisin (10−3 mg/mL). Protein samples were analyzed by multidimensional protein identification technology (MudPIT) approach, in an off-line configuration. The raw MS/MS data allowed the detection of 49,591 spectra which resulted in 576 protein identifications. After Scaffold validation, 179 proteins were identified with high confidence. A label-free quantitative analysis based of normalized spectral abundance factor (NSAF) was used and 13 proteins were found differentially expressed between nisin-treated and non-treated cells. Gene ontology analysis of differentially expressed proteins revealed that most of them are correlated to metabolic process, oxidative stress response mechanisms and molecular binding. A detailed analysis and discussion of these data may be found in Miyamoto et al. [1]. PMID:26217729

  11. Sublethal Exposure to Clove and Cinnamon Essential Oils Induces Hormetic-Like Responses and Disturbs Behavioral and Respiratory Responses in Sitophilus zeamais (Coleoptera: Curculionidae).

    Science.gov (United States)

    Haddi, Khalid; Oliveira, Eugênio E; Faroni, Lêda R A; Guedes, Daniela C; Miranda, Natalie N S

    2015-12-01

    Essential oils have been suggested as suitable alternatives for controlling insect pests. However, the potential adaptive responses elicited in insects for mitigating the actions of these compounds have not received adequate attention. Furthermore, as is widely reported with traditional insecticides, sublethal exposure to essential oils might induce stimulatory responses or contribute to the development of resistance strategies that can compromise the management of insect pests. The current study evaluated the locomotory and respiratory responses as well as the number of larvae per grain produced by the maize weevil, Sitophilus zeamais Motschulsky, after being sublethally exposed to the essential oils of clove, Syzygium aromaticum L., and cinnamon, Cinnamomum zeylanicum L. The essential oils showed similar insecticidal toxicity (exposure route: contact with dried residues; Clove LC95 = 3.96 [2.78-6.75] µl/cm(2); Cinnamon LC95 = 3.47 [2.75-4.73] µl/cm(2)). A stimulatory effect on the median survival time (TL50) was observed when insects were exposed to low concentrations of each oil. Moreover, a higher number of larvae per grain was produced under sublethal exposure to clove essential oil. S. zeamais avoided the treated areas (in free-choice experiments) and altered their mobility when sublethally exposed to both essential oils. The respiratory rates of S. zeamais (i.e., CO2 production) were significantly reduced under low concentrations of the essential oils. We recommend the consideration of the potential sublethal effects elicited by botanical pesticides during the development of integrated pest management programs aiming to control S. zeamais. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Effect of titanium tetrafluoride and amine fluoride treatment combined with carbon dioxide laser irradiation on enamel and dentin erosion.

    Science.gov (United States)

    Wiegand, Annette; Magalhães, Ana Carolina; Navarro, Ricardo Scarparo; Schmidlin, Patrick Roger; Rios, Daniela; Buzalaf, Marilia Afonso Ribeiro; Attin, Thomas

    2010-04-01

    This in vitro study aimed to analyze the influence of carbon dioxide (CO(2)) laser irradiation on the efficacy of titanium tetrafluoride (TiF(4)) and amine fluoride (AmF) in protecting enamel and dentin against erosion. Bovine enamel and dentin samples were pretreated with carbon dioxide (CO(2)) laser irradiation only (group I), TiF(4) only (1% F, group II), CO(2) laser irradiation before (group III) or through (group IV) TiF(4) application, AmF only (1% F, group V), or CO(2) laser irradiation before (group VI) or through (group VII) AmF application. Controls remained untreated. Ten samples of each group were then subjected to an erosive demineralization and remineralization cycling for 5 days. Enamel and dentin loss were measured profilometrically after pretreatment, 4 cycles (1 day), and 20 cycles (5 days) and statistically analyzed using analysis of variance and Scheffe's post hoc tests. Scanning electron microscopy (SEM) analysis was performed in pretreated but not cycled samples (two samples each group). After 20 cycles, there was significantly less enamel loss in groups V and IV and significantly less dentin loss in group V only. All other groups were not significantly different from the controls. Lased surfaces (group I) appeared unchanged in the SEM images, although SEM images of enamel but not of dentin showed that CO(2) laser irradiation affected the formation of fluoride precipitates. AmF decreased enamel and dentin erosion, but CO(2) laser irradiation did not improve its efficacy. TiF(4) showed only a limited capacity to prevent erosion, but CO(2) laser irradiation significantly enhanced its ability to reduce enamel erosion.

  13. Food irradiation and sterilization

    Science.gov (United States)

    Josephson, Edward S.

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25-70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning is achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70-80°C (bacon to 53°C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-40°C to -20°C). Radappertozed foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for "wholesomeness" (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effecys of radappertization on the "wholesomeness" characteristics of these foods.

  14. Sublethal mechanisms of Pb and Zn toxicity to the purple sea urchin (Strongylocentrotus purpuratus) during early development.

    Science.gov (United States)

    Tellis, Margaret S; Lauer, Mariana M; Nadella, Sunita; Bianchini, Adalto; Wood, Chris M

    2014-01-01

    In order to understand sublethal mechanisms of lead (Pb) and zinc (Zn) toxicity, developing sea urchins were exposed continuously from 3h post-fertilization (eggs) to 96 h (pluteus larvae) to 55 (±2.4) μgPb/L or 117 (±11)μgZn/L, representing ~ 70% of the EC50 for normal 72 h development. Growth, unidirectional Ca uptake rates, whole body ion concentrations (Na, K, Ca, Mg), Ca(2+) ATPase activity, and metal bioaccumulation were monitored every 12h over this period. Pb exhibited marked bioaccumulation whereas Zn was well-regulated, and both metals had little effect on growth, measured as larval dry weight, or on Na, K, or Mg concentrations. Unidirectional Ca uptake rates (measured by (45)Ca incorporation) were severely inhibited by both metals, resulting in lower levels of whole body Ca accumulation. The greatest disruption occurred at gastrulation. Ca(2+) ATPase activity was also significantly inhibited by Zn but not by Pb. Interestingly, embryos exposed to Pb showed some capacity for recovery, as Ca(2+)ATPase activities increased, Ca uptake rates returned to normal intermittently, and whole body Ca levels were restored to control values by 72-96 h of development. This did not occur with Zn exposure. Both Pb and Zn rendered their toxic effects through disruption of Ca homeostasis, though likely through different proximate mechanisms. We recommend studying the toxicity of these contaminants periodically throughout development as an effective way to detect sublethal effects, which may not be displayed at the traditional toxicity test endpoint of 72 h. Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Assessment of acute sublethal effects of clothianidin on motor function of honeybee workers using video-tracking analysis.

    Science.gov (United States)

    Alkassab, Abdulrahim T; Kirchner, Wolfgang H

    2018-01-01

    Sublethal impacts of pesticides on the locomotor activity might occur to different degrees and could escape visual observation. Therefore, our objective is the utilization of video-tracking to quantify how the acute oral exposure to different doses (0.1-2ng/bee) of the neonicotinoid "clothianidin" influences the locomotor activity of honeybees in a time course experiment. The total distance moved, resting time as well as the duration and frequency of bouts of laying upside down are measured. Our results show that bees exposed to acute sublethal doses of clothianidin exhibit a significant increase in the total distance moved after 30 and 60min of the treatment at the highest dose (2ng/bee). Nevertheless, a reduction of the total distance is observed at this dose 90min post-treatment compared to the distance of the same group after 30min, where the treated bees show an arched abdomen and start to lose their postural control. The treated bees with 1ng clothianidin show a significant increase in total distance moved over the experimental period. Moreover, a reduction in the resting time and increase of the duration and frequency of bouts of laying upside down at these doses are found. Furthermore, significant effects on the tested parameters are observed at the dose (0.5ng/bee) first at 60min post-treatment compared to untreated bees. The lowest dose (0.1ng/bee) has non-significant effects on the motor activity of honeybees compared to untreated bees over the experimental period. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Lethal and sub-lethal effects of elevated CO2 concentrations on marine benthic invertebrates and fish.

    Science.gov (United States)

    Lee, Changkeun; Hong, Seongjin; Kwon, Bong-Oh; Lee, Jung-Ho; Ryu, Jongseong; Park, Young-Gyu; Kang, Seong-Gil; Khim, Jong Seong

    2016-08-01

    Concern about leakage of carbon dioxide (CO2) from deep-sea storage in geological reservoirs is increasing because of its possible adverse effects on marine organisms locally or at nearby coastal areas both in sediment and water column. In the present study, we examined how elevated CO2 affects various intertidal epibenthic (benthic copepod), intertidal endobenthic (Manila clam and Venus clam), sub-tidal benthic (brittle starfish), and free-living (marine medaka) organisms in areas expected to be impacted by leakage. Acute lethal and sub-lethal effects were detected in the adult stage of all test organisms exposed to varying concentrations of CO2, due to the associated decline in pH (8.3 to 5.2) during 96-h exposure. However, intertidal organisms (such as benthic copepods and clams) showed remarkable resistance to elevated CO2, with the Venus clam being the most tolerant (LpH50 = 5.45). Sub-tidal species (such as brittle starfish [LpH50 = 6.16] and marine medaka [LpH50 = 5.91]) were more sensitive to elevated CO2 compared to intertidal species, possibly because they have fewer defensive capabilities. Of note, the exposure duration might regulate the degree of acute sub-lethal effects, as evidenced by the Venus clam, which showed a time-dependent effect to elevated CO2. Finally, copper was chosen as a model toxic element to find out the synergistic or antagonistic effects between ocean acidification and metal pollution. Combination of CO2 and Cu exposure enhances the adverse effects to organisms, generally supporting a synergistic effect scenario. Overall, the significant variation in the degree to which CO2 adversely affected organisms (viz., working range and strength) was clearly observed, supporting the general concept of species-dependent effects of elevated CO2.

  17. Sublethal Staphylococcal Enterotoxin B Challenge Model in Pigs To Evaluate Protection following Immunization with a Soybean-Derived Vaccine

    Science.gov (United States)

    Hudson, Laura C.; Seabolt, Brynn S.; Odle, Jack; Stahl, Chad H.; Piller, Kenneth J.

    2013-01-01

    In an effort to develop a sustainable platform for manufacturing protein-based vaccine candidates, we expressed a triple mutant of staphylococcal enterotoxin B carrying the L45R, Y89A, and Y94A modifications in transgenic soybean seeds (soy-mSEB). Soy-mSEB possessed no detectable superantigen activity in vitro. We found that this soybean-derived, nontoxic mutant of SEB could be stably expressed, stored in seeds for extended periods at room temperature without degradation, and easily purified from contaminating soy proteins. Vaccination of pigs with purified soy-mSEB, or the identical triple mutant expressed in Escherichia coli (E. coli-mSEB), resulted in high antibody titers against the native toxin in immunized animals. In fact, titers were indistinguishable regardless of the immunogen used, demonstrating the equivalence of soy-mSEB and E. coli-mSEB vaccinations. Antisera from either immunized group were able to block native SEB superantigen activity in an in vitro neutralization assay. Similar results were obtained when immunized animals were challenged with a sublethal dose of native toxin. Significant reductions in toxin-induced serum cytokine levels were observed in soy-mSEB- and E. coli-mSEB-immunized pigs compared to control animals. The reductions in SEB-induced cytokine responses were similar regardless of the immunogen used for vaccination. Surprisingly, however, some clinical symptoms, such as prostration, lethargy, emesis, and/or diarrhea, were still observed in all immunized animals. These studies demonstrate the potential for soybean-derived proteins as a platform technology for sustainable vaccine manufacturing and the usefulness of a sublethal challenge model in pigs for evaluating the efficacy of potential SEB vaccine candidates. PMID:23114702

  18. Extended hypoxia in the alfalfa leafcutting bee, Megachile rotundata, increases survival but causes sub-lethal effects.

    Science.gov (United States)

    Abdelrahman, H; Rinehart, J P; Yocum, G D; Greenlee, K J; Helm, B R; Kemp, W P; Schulz, C H; Bowsher, J H

    2014-05-01

    Many insects are tolerant of hypoxic conditions, but survival may come at a cost to long-term health. The alfalfa leaf-cutting bee, Megachile rotundata, develops in brood cells inside natural cavities, and may be exposed to hypoxic conditions for extended periods of time. Whether M. rotundata is tolerant of hypoxia, and whether exposure results in sub-lethal effects, has never been investigated. Overwintering M. rotundata prepupae were exposed to 10%, 13%, 17%, 21% and 24% O2 for 11 months. Once adults emerged, five indicators of quality - emergence weight, body size, feeding activity, flight performance, and adult longevity, - were measured to determine whether adult bees that survived past exposure to hypoxia were competent pollinators. M. rotundata prepupae are tolerant of hypoxic condition and have higher survival rates in hypoxia, than in normoxia. Under hypoxia, adult emergence rates did not decrease over the 11 months of the experiment. In contrast, bees reared in normoxia had decreased emergence rates by 8 months, and were dead by 11 months. M. rotundata prepupae exposed to extended hypoxic conditions had similar emergence weight, head width, and cross-thorax distance compared to bees reared in standard 21% oxygen. Despite no significant morphological differences, hypoxia-exposed bees had lower feeding rates and shorter adult lifespans. Hypoxia may play a role in post-diapause physiology of M. rotundata, with prepupae showing better survival under hypoxic conditions. Extended exposure to hypoxia, while not fatal, causes sub-lethal effects in feeding rates and longevity in the adults, indicating that hypoxia tolerance comes at a cost. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  19. Lethal and Sublethal Toxicity Comparison of BFRs to Three Marine Planktonic Copepods: Effects on Survival, Metabolism and Ingestion.

    Directory of Open Access Journals (Sweden)

    Wenjing Gong

    Full Text Available The estuarine planktonic copepods have a wide geographical distribution and commendable tolerance to various kinds of contaminants. The primary aim of the present study was to contrast the impacts of model POPs (TBBPA and HBCD on three common estuarine planktonic copepods (Oithona similis, Acartia pacifica and Pseudodiaptomus inopinus and establish a protocol for the assessment of acute toxicity of marine organic pollutants. We first quantified the 96h-LC50 (0.566, 0.04 and 0.257 mg/L of TBBPA to the three subjects above respectively and 0.314 mg/L of HBCD to P. inopinus; all reported concentrations are nominal values. In the sub-lethal toxicity tests, it was turned out that the effects of copepods exposed to TBBPA could product different influences on the energy ingestion and metabolism. Different type of pollutions, meanwhile, could also bring varying degree effect on the target copepods. In general, the indicators (the rate of oxygen consumption, ammonia excretion, food ingestion and filtration in higher concentration groups showed marked significant difference compared with controls as well a dose-effect relationship. The study also extended the research on the joint toxicity of TBBPA and HBCD based on the survival rate of P.inopinus. Whether 1:1 concentration or 1:1 toxic level, the research showed synergy effect relative to single exposure conditions. The result indicated that current single ecological testing used for environmental protection activities may underestimate the risk for copepods. It was also demonstrated that short-term sub-lethal experiment could be a standard to evaluate the sensitivity of copepods to POPs.

  20. Sublethal Effects of Cyantraniliprole and Imidacloprid on Feeding Behavior and Life Table Parameters of Myzus persicae (Hemiptera: Aphididae).

    Science.gov (United States)

    Zeng, Xianyi; He, Yingqin; Wu, Jiaxing; Tang, Yuanman; Gu, Jitao; Ding, Wei; Zhang, Yongqiang

    2016-08-01

    The green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), is an agricultural pest that seriously infests many crops worldwide. This study used electrical penetration graphs (EPGs) and life table parameters to estimate the sublethal effects of cyantraniliprole and imidacloprid on the feeding behavior and hormesis of M. persicae The sublethal concentrations (LC30) of cyantraniliprole and imidacloprid against adult M. persicae were 4.933 and 0.541 mg L(-1), respectively. The feeding data obtained from EPG analysis indicated that the count probes and number of short probes (<3 min) were significantly increased when aphids were exposed to LC30 of imidacloprid-treated plants. In addition, the phloem-feeding behavior of M persicae was significantly impaired on fed tobacco plants treated with cyantraniliprole and imidacloprid at LC30 Analysis of life table parameters indicated that the growth and reproduction of F1 generation aphids were significantly affected when initial adults were exposed to LC30 of cyantraniliprole and imidacloprid. The nymphal period, female longevity, total preoviposition period, and mean generation time were significantly prolonged when initial adults were exposed to LC30 of imidacloprid. By comparison, these parameters were prolonged but not significantly in the cyantraniliprole treatment. The fecundity and gross reproductive rate were significantly increased in the treated groups. Similarly, the net reproductive rate was greater in the treated group than the control group. Our results indicate that treatment with LC30 of imidacloprid and cyantraniliprole would lead to a hormetic response of M. persicae, with higher likelihood of occurrence when initial adults were exposed to LC30 of cyantraniliprole. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Sub-lethal effects of pesticide residues in brood comb on worker honey bee (Apis mellifera development and longevity.

    Directory of Open Access Journals (Sweden)

    Judy Y Wu

    Full Text Available BACKGROUND: Numerous surveys reveal high levels of pesticide residue contamination in honey bee comb. We conducted studies to examine possible direct and indirect effects of pesticide exposure from contaminated brood comb on developing worker bees and adult worker lifespan. METHODOLOGY/PRINCIPAL FINDINGS: Worker bees were reared in brood comb containing high levels of known pesticide residues (treatment or in relatively uncontaminated brood comb (control. Delayed development was observed in bees reared in treatment combs containing high levels of pesticides particularly in the early stages (day 4 and 8 of worker bee development. Adult longevity was reduced by 4 days in bees exposed to pesticide residues in contaminated brood comb during development. Pesticide residue migration from comb containing high pesticide residues caused contamination of control comb after multiple brood cycles and provided insight on how quickly residues move through wax. Higher brood mortality and delayed adult emergence occurred after multiple brood cycles in contaminated control combs. In contrast, survivability increased in bees reared in treatment comb after multiple brood cycles when pesticide residues had been reduced in treatment combs due to residue migration into uncontaminated control combs, supporting comb replacement efforts. Chemical analysis after the experiment confirmed the migration of pesticide residues from treatment combs into previously uncontaminated control comb. CONCLUSIONS/SIGNIFICANCE: This study is the first to demonstrate sub-lethal effects on worker honey bees from pesticide residue exposure from contaminated brood comb. Sub-lethal effects, including delayed larval development and adult emergence or shortened adult longevity, can have indirect effects on the colony such as premature shifts in hive roles and foraging activity. In addition, longer development time for bees may provide a reproductive advantage for parasitic Varroa destructor

  2. Stress response of the black coral Leiopathes glaberrima when exposed to sub-lethal amounts of crude oil and dispersant

    Directory of Open Access Journals (Sweden)

    Dannise V. Ruiz-Ramos

    2017-12-01

    Full Text Available The 2010 Deep Water Horizon oil well failure released billions of gallons of crude oil into the deep Gulf of Mexico, and, combined with chemical dispersants, this oil caused significant coral mortality. However, the mechanisms by which oil and dispersed oil impact deep marine fauna are not well understood. Here, we investigate the effects of oil and dispersed oil on a black coral common in the deep Gulf of Mexico, 'Leiopathes glaberrima. 'This coral occurs in several color morphs that show ecological and genetic differences. We hypothesized that dispersed oil would be more detrimental to coral health than oil alone and that this difference would be detectable in the gene expression response of the colonies even at sub-lethal concentrations. In two experiments, four and six colonies of red and white color morphs were exposed to oil, dispersant, and dispersed oil for a minimum of 96 hours. Visual assessment indicated that indeed dispersant and dispersed oil treatments were more damaging than oil alone, for target concentrations of 25 mg L–1. Decline in health was observed for all treatments, independently of color morphotype, but the decline was faster in the white colonies exposed to dispersant. The responses to the treatments were also investigated by monitoring gene expression after 24 hours of sub-lethal chemical exposure. Coral gene expression differed by chemical stressor. Interestingly, the polycyclic aromatic hydrocarbon biomarker gene, cytochrome P450, was only up-regulated in dispersed oil but not oil alone, suggesting that the dispersant increased the availability of such hydrocarbons in the tissue. The gene expression response was apparent at 24 hours when visual impacts were not (yet detectable. The use of chemical dispersants in oil-spill remediation may cause health declines in deep-water corals and deserves further study.

  3. Melatonin may play a role in modulation of bax and bcl-2 expression levels to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Mohseni, Mehran [Department of Radiology and Medical Physics, Faculty of Paramedicine, Kashan University of Medical Sciences, Kashan (Iran, Islamic Republic of); Mihandoost, Ehsan, E-mail: mihandoost.e@gmail.com [Department of Medical Radiation Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Shirazi, Alireza [Department of Medical Physics and Biomedical Engineering, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Sepehrizadeh, Zargham [Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Bazzaz, Javad Tavakkoly [Department of Medical Genetics, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ghazi-khansari, Mahmoud [Department of Pharmacology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2012-10-15

    The close relationship between free radicals effects and apoptosis process has been proved. Melatonin has been reported as a direct free radical scavenger. We investigated the capability of melatonin in the modification of radiation-induced apoptosis and apoptosis-associated upstream regulators expression in rat peripheral blood lymphocytes. Rats were irradiated with a single whole body Cobalt 60-gamma radiation dose of 8 Gy at a dose rate of 101 cGy/min with or without melatonin pretreatments at different concentrations of 10 and 100 mg/kg body weight. The rats were divided into eight groups of control, irradiation-only, vehicle-only, vehicle plus irradiation, 10 mg/kg melatonin alone, 10 mg/kg melatonin plus irradiation, 100 mg/kg melatonin alone and 100 mg/kg melatonin plus irradiation. Rats were given an intraperitoneal (IP) injection of melatonin or the same volume of vehicle alone 1 h prior to irradiation. Blood samples were taken 4, 24, 48 and 72 h after irradiation for evaluation of flow cytometric analysis of apoptotic lymphocytes using Annexin V/PI assay and measurement of bax and bcl-2 expression using quantitative real-time PCR (RT{sup 2}qPCR). Irradiation-only and vehicle plus irradiation showed an increase in the percentage of apoptotic lymphocytes significantly different from control group (P < 0.01), while melatonin pretreatments in a dose-dependent manner reduced it as compared with the irradiation-only and vehicle plus irradiation groups (P < 0.01) in all time points. This reduced apoptosis by melatonin was related to the downregulation of bax, upregulation of bcl-2, and therefore reduction of bax/bcl-2 ratio. Our results suggest that melatonin in these doses may provide modulation of bax and bcl-2 expression as well as bax/bcl-2 ratio to protect rat peripheral blood lymphocytes from gamma irradiation-induced apoptosis.

  4. The characteristic changes of betung bamboo (Dendrocalamus asper pretreated by fungal pretreatment

    Directory of Open Access Journals (Sweden)

    Widya Fatriasari

    2014-05-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE MicrosoftInternetExplorer4 The fungal pretreatment effect on chemical structural and morphological changes of Betung Bamboo was evaluated based on its biomass components after being cultivated by white rot fungi, Trametes versicolor. Betung bamboo powder (15 g was exposed to liquid inoculum of white rot fungi and incubated at 270C for 15, 30 and 45 days. The treated samples were then characterized by FT-IR spectroscopy, X-Ray diffraction and SEM-EDS analyses. Cultivation for 30 days with 5 and 10% loadings retained greater selectivity compared to that of the other treatments. FTIR spectra demonstrated that the fungus affected the decreasing of functional group quantities without changing the functional groups. The decrease in intensity at wave number of 1246 cm-1 (guaiacyl of lignin was greater than that at wave number of 1328 cm-1 (deformation combination of syringyl and xylan after fungal treatment. X-ray analysis showed the pretreated samples had a higher crystallinity than the untreated ones which might be due to the cleavage of amorphous fractions of cellulose. The pretreated samples have more fragile than the untreated ones confirmed by SEM. Crystalline allomorph calculated by XRD analysis showed that fungus pretreatment for 30 days has transformed triclinic structure of cellulose to monoclinic structure.

  5. Microbial Lipid Production from Enzymatic Hydrolysate of Pecan Nutshell Pretreated by Combined Pretreatment.

    Science.gov (United States)

    Qin, Lizhen; Qian, Hanyu; He, Yucai

    2017-12-01

    Biodiesel is a fuel composed of monoalkyl esters of long-chain fatty acids derived from renewable biomass sources. In this study, biomass waste pecan nutshell (PS) was attempted to be converted into microbial oil. For effective utilization of PS, sequential pretreatment with ethylene glycol-H2SO4-water (78:2:20, wt:wt:wt) at 130 °C for 30 min and aqueous ammonia (25 wt%) at 50 °C for 24 h was used to enhance its enzymatic saccharification. Significant linear correlation was obtained about delignification-saccharification (R 2 = 0.9507). SEM and FTIR results indicated that combination pretreatment could effectively remove lignin and xylan in PS for promoting its enzymatic saccharification. After 72 h, the reducing sugars from the hydrolysis of 50 g/L pretreated PS by combination pretreatment could be obtained at 73.6% yield. Using the recovered PS hydrolysates containing 20 g/L glucose as carbon source, microbial lipids produced from the PS hydrolysates by Rhodococcus opacus ACCC41043. Four fatty acids including palmitic acid (C16:0; 23.1%), palmitoleic acid (C16:1; 22.4%), stearic acid (C18:0; 15.3%), and oleic acid (C18:1; 23.9%) were distributed in total fatty acids. In conclusion, this strategy has potential application in the future.

  6. Acetic acid pretreatment improves the hardness of cooked potato slices.

    Science.gov (United States)

    Zhao, Wenlin; Shehzad, Hussain; Yan, Shoulei; Li, Jie; Wang, Qingzhang

    2017-08-01

    The effects of acetic acid pretreatment on the texture of cooked potato slices were investigated in this work. Potato slices were pretreated with acetic acid immersion (AAI), distilled water immersion (DWI), or no immersion (NI). Subsequently, the cell wall material of the pretreated samples was isolated and fractioned to evaluate changes in the monosaccharide content and molar mass (MM), and the hardness and microscopic structure of the potato slices in different pretreatments before and after cooking were determined. The results showed that the highest firmness was obtained with more intact structure of the cell wall for cooked potato slices with AAI pretreatment. Furthermore, the MM and sugar ratio demonstrated that the AAI pretreated potato slices contained a higher content of the small molecular polysaccharides of cell walls, especially in the hemicellulose fraction. This work may provide a reference for potato processing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Impact of pretreatment on colour and texture of watermelon rind

    Science.gov (United States)

    Athmaselvi, K.; Alagusundaram, K.; Kavitha, C.; Arumuganathan, T.

    2012-07-01

    The effect of osmotic dehydration pretreatment on water loss, solid gain, colour and textural change was investigated. Watermelon rind 1 x 1 cm size was immersed in sucrose solution of 40, 50 and 60° Brix after pretreatment with microwave and conventional boiling in water for 1, 3, and 5 min, respectively. Water loss and solid gain increased with the time of cooking and sugar concentration. Microwave pretreated samples showed higher water loss and solid gain. Increase in the time of cooking decreased the brightness of all the samples. Microwave pretreated samples showed higher `b' values than conventionally pretreated ones. There was no significant difference (P≤0.05) in texture profile analysis parameters except for hardness. Hardness decreased with increase in time of cooking and sugar concentration. Second order regression model was developed for water loss and solid gain of microwave and conventional pretreated watermelon rind.

  8. EFFECT OF AQUEOUS PRETREATMENT ON PYROLYSIS CHARACTERISTICS OF NAPIER GRASS

    Directory of Open Access Journals (Sweden)

    ISAH YAKUB MOHAMMED

    2015-11-01

    Full Text Available Effect of non-catalytic aqueous pretretment on pyrolysis characteristics of Napier grass was investigated using thermogravimetric analyser. Increasing pretreatment severity (0.0-2.0 improved pyrolysis process. The residual mass at the end of pyrolysis for the pretreated sample was about 50% less compared to the untreated sample. Kinetics of the process was evaluated using order based model and both pretreated and untreated samples followed first order reaction. The activation energy of the pretreated samples was similar and higher than that of the raw sample which was attributed to faster rate of decomposition due removal of hetromaterials (ash, extractives and some hemicellulose in the pretreatment stage. Finally, this pretreatment method has demonstrated effectiveness for the removal of pyrolysis retardants and will improve the quantity and quality of bio-oil yield.

  9. Dilute acid pretreatment of corncob for efficient sugar production

    Science.gov (United States)

    G.S. Wang; Jae-Won Lee; Junyong Zhu; Thomas W. Jeffries

    2011-01-01

    Aqueous dilute acid pretreatments of corncob were conducted using cylindrical pressure vessels in an oil bath. Pretreatments were conducted in a temperature range of 160–190 °C with acid-solution-to-solid-corncob ratio of 2. The acid concentration (v/v) in the pretreatment solution was varied from 0% to 0.7%, depending on temperature. This gives acid charge on ovendry-...

  10. K basins sludge removal sludge pretreatment system

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H.L.

    1997-06-12

    The Spent Nuclear Fuels Program is in the process of planning activities to remove spent nuclear fuel and other materials from the 100-K Basins as a remediation effort for clean closure. The 105 K- East and K-West Basins store spent fuel, sludge, and debris. Sludge has accumulated in the 1 00 K Basins as a result of fuel oxidation and a slight amount of general debris being deposited, by settling, in the basin water. The ultimate intent in removing the sludge and fuel is to eliminate the environmental risk posed by storing fuel at the K Basins. The task for this project is to disposition specific constituents of sludge (metallic fuel) to produce a product stream through a pretreatment process that will meet the requirements, including a final particle size acceptable to the Tank Waste Remediation System (TWRS). The purpose of this task is to develop a preconceptual design package for the K Basin sludge pretreatment system. The process equipment/system is at a preconceptual stage, as shown in sketch ES-SNF-01 , while a more refined process system and material/energy balances are ongoing (all sketches are shown in Appendix C). Thus, the overall process and 0535 associated equipment have been conservatively selected and sized, respectively, to establish the cost basis and equipment layout as shown in sketches ES- SNF-02 through 08.

  11. Biologically Pre-Treated Habitation Waste Water as a Sustainable Green Urine Pre-Treat Solution

    Science.gov (United States)

    Jackson, W. Andrew; Thompson, Bret; Sevanthi, Ritesh; Morse, Audra; Meyer, Caitlin; Callahan, Michael

    2017-01-01

    The ability to recover water from urine and flush water is a critical process to allow long term sustainable human habitation in space or bases on the moon or mars. Organic N present as urea or similar compounds can hydrolyze producing free ammonia. This reaction results in an increase in the pH converting ammonium to ammonia which is volatile and not removed by distillation. The increase in pH will also cause precipitation reactions to occur. In order to prevent this, urine on ISS is combined with a pretreat solution. While use of a pretreatment solution has been successful, there are numerous draw backs including: storage and use of highly hazardous solutions, limitations on water recovery (less than 85%), and production of brine with pore dewatering characteristics. We evaluated the use of biologically treated habitation wastewaters (ISS and early planetary base) to replace the current pretreat solution. We evaluated both amended and un-amended bioreactor effluent. For the amended effluent, we evaluated "green" pretreat chemicals including citric acid and citric acid amended with benzoic acid. We used a mock urine/air separator modeled after the urine collection assembly on ISS. The urine/air separator was challenged continually for >6 months. Depending on the test point, the separator was challenged daily with donated urine and flushed with amended or un-amended reactor effluent. We monitored the pH of the urine, flush solution and residual pH in the urine/air separator after each urine event. We also evaluated solids production and biological growth. Our results support the use of both un-amended and amended bioreactor effluent to maintain the operability of the urine /air separator. The ability to use bioreactor effluent could decrease consumable cost, reduce hazards associated with current pre-treat chemicals, allow other membrane based desalination processes to be utilized, and improve brine characteristics.

  12. Optimal pretreatment determination of kiwifruit drying via online monitoring.

    Science.gov (United States)

    Nadian, Mohammad Hossein; Abbaspour-Fard, Mohammad Hossein; Sadrnia, Hassan; Golzarian, Mahmood Reza; Tabasizadeh, Mohammad

    2016-11-01

    Pre-treating is a crucial stage of drying process. The best pretreatment for hot air drying of kiwifruit was investigated using a computer vision system (CVS), for online monitoring of drying attributes including drying time, colour changes and shrinkage, as decision criteria and using clustering method. Slices were dried at 70 °C with hot water blanching (HWB), steam blanching (SB), infrared blanching (IR) and acid ascorbic 1% w/w (AA) as pretreatments each with three durations of 5, 10 and 15 min. The results showed that the cells in HWB-pretreated samples stretched without any cell wall rupture, while the highest damage was observed in AA-pretreated kiwifruit microstructure. Increasing duration of AA and HWB significantly lengthened the drying time while SB showed opposite results. The drying rate had a profound effect on the progression of the shrinkage. The total colour change of pretreated samples was higher than those with no pretreatment except for AA and HWB. The AA could well prevent colour change during the initial stage of drying. Among all pretreatments, SB and IR had the highest colour changes. HWB with a duration of 5 min is the optimum pretreatment method for kiwifruit drying. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  13. Feasibility of Hydrothermal Pretreatment on Maize Silage for Bioethanol Production

    DEFF Research Database (Denmark)

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2010-01-01

    The potential of maize silage as a feedstock to produce bioethanol was evaluated in the present study. The hydrothermal pretreatment with five different pretreatment severity factors (PSF) was employed to pretreat the maize silage and compared in terms of sugar recovery, toxic test, and ethanol...... the liquors from the five conditions were not toxic to the Baker’s yeast. Pretreatment under 195°C for 7 min had the similar PSF with that of 185°C for 15 min, and both gave the higher ethanol concentration of 19.92 and 19.98 g/L, respectively. The ethanol concentration from untreated maize silage was only 7...

  14. Nonhazardous Urine Pretreatment Method for Future Exploration Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A nonhazardous urine pretreatment system prototype is proposed that will stabilize urine against biological growth or chemical instabilities without using hazardous...

  15. Value added liquid products from waste biomass pyrolysis using pretreatments.

    Science.gov (United States)

    Das, Oisik; Sarmah, Ajit K

    2015-12-15

    Douglas fir wood, a forestry waste, was attempted to be converted into value added products by pretreatments followed by pyrolysis. Four different types of pretreatments were employed, namely, hot water treatment, torrefaction, sulphuric acid and ammonium phosphate doping. Subsequently, pyrolysis was done at 500°C and the resulting bio-oils were analysed for their chemical composition using Karl Fischer titration, thermogravimetry, ion exchange, and gas chromatography. Pretreatment with acid resulted in the highest yield of bio-oil (~60%). The acid and salt pretreatments were responsible for drastic reduction in the lignin oligomers and enhancement of water content in the pyrolytic liquid. The quantity of xylose/mannose reduced as a result of pretreatments. Although, the content of fermentable sugars remained similar across all the pretreatments, the yield of levoglucosan increased. Pretreatment of the biomass with acid yielded the highest amount of levoglucosan in the bio-oil (13.21%). The acid and salt pretreatments also elevated the amount of acetic acid in the bio-oils. Addition of acid and salt to the biomass altered the interaction of cellulose-lignin in the pyrolysis regime. Application of pretreatments should be based on the intended end use of the liquid product having a desired chemical composition. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Nonhazardous Urine Pretreatment Method for Future Exploration Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A novel urine pretreatment that will prevent biological growth or chemical instabilities in urine without using hazardous chemicals is proposed. Untreated urine...

  17. Influence of dentin pretreatment on bond strength of universal adhesives.

    Science.gov (United States)

    Poggio, Claudio; Beltrami, Riccardo; Colombo, Marco; Chiesa, Marco; Scribante, Andrea

    2017-01-01

    Objective: The purpose of the present study was to compare bond strength of different universal adhesives under three different testing conditions: when no pretreatment was applied, after 37% phosphoric acid etching and after glycine application. Materials and methods: One hundred and fifty bovine permanent mandibular incisors were used as a substitute for human teeth. Five different universal adhesives were tested: Futurabond M+, Scotchbond Universal, Clearfil Universal Bond, G-Premio BOND, Peak Universal Bond. The adhesive systems were applied following each manufacturer's instructions. The teeth were randomly assigned to three different dentin surface pretreatments: no pretreatment agent (control), 37% phosphoric acid etching, glycine pretreatment. The specimens were placed in a universal testing machine in order to measure and compare bond strength values. Results: The Kruskal-Wallis analysis of variance and the Mann-Whitney test were applied to assess significant differences among the groups. Dentin pretreatments provided different bond strength values for the adhesives tested, while similar values were registered in groups without dentin pretreatment. Conclusions: In the present report, dentin surface pretreatment did not provide significant differences in shear bond strength values of almost all groups. Acid pretreatment lowered bond strength values of Futurabond and Peak Universal Adhesives, whereas glycine pretreatment increased bond strength values of G Praemio Bond adhesive system.

  18. CO.sub.2 Pretreatment prevents calcium carbonate formation

    Science.gov (United States)

    Neavel, Richard C.; Brunson, Roy J.; Chaback, Joseph J.

    1980-01-01

    Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with carbon dioxide. The carbon dioxide pretreatment is believed to convert the scale-forming components to the corresponding carbonate prior to liquefaction. The pretreatment is accomplished at a total pressure within the range from about 14 to about 68 atmospheres and a carbon dioxide partial pressure within the range from about 14 to about 34 atmospheres. Temperature during pretreatment will generally be within the range from about 100.degree. to about 200.degree. C.

  19. 40 CFR 417.84 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Soaps Subcategory § 417.84 Pretreatment standards for existing sources. Any existing source...

  20. Enhanced mass transfer during solid-liquid extraction of gamma-irradiated red beetroot

    Energy Technology Data Exchange (ETDEWEB)

    Nayak, Chetan A. [Department of Food Engineering, Central Food Technological Research Institute, Mysore 570 020 (India); Chethana, S. [Department of Food Engineering, Central Food Technological Research Institute, Mysore 570 020 (India); Rastogi, N.K. [Department of Food Engineering, Central Food Technological Research Institute, Mysore 570 020 (India)]. E-mail: nkrastogi@cftri.com; Raghavarao, K.S.M.S. [Department of Food Engineering, Central Food Technological Research Institute, Mysore 570 020 (India)

    2006-01-15

    The exposure to gamma-irradiation pretreatment increases cell wall permeabilization, resulting in loss of turgor pressure, which led to the increase of extractability of betanin from red beetroot. The degree of extraction of betanin was investigated using gamma irradiation as a pretreatment prior to the solid-liquid extraction process and compared with control beetroot samples. The beetroot subjected to different doses of gamma irradiation (2.5, 5.0, 7.5, 10.0 kGy) and control was dipped in an acetic acid medium (1% v/v) to extract the betanin. The diffusion coefficients for betanin as well as ionic component were estimated considering Fickian diffusion. The results indicated an increase in the diffusion coefficient of betanin (0.302x10{sup -9}-0.463x10{sup -9} m{sup 2}/s) and ionic component (0.248x10{sup -9}-0.453x10{sup -9} m{sup 2}/s) as the dose rate increased (from 2.5 to 10.0 kGy). The degradation constant was found to increase (0.050-0.079 min{sup -1}) with an increase gamma-irradiation doses (2.5-10.0 kGy), indicating lower stability of the betanin as compared to control sample at 65 deg. C.

  1. Sensorial evaluation of irradiated mangoes

    Energy Technology Data Exchange (ETDEWEB)

    Broisler, Paula Olhe; Cruz, Juliana Nunes da; Sabato, Susy Frey [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mails: paulabroisler@hotmail.com; juliananc@ig.com.br; sfsabato@ipen.br

    2007-07-01

    Mango (Mangifera indica L.) is a tropical fruit of great economical relevance in the world, mainly for tropical countries like Brazil. It consists in the second tropical fruit more important grown in the world. On the other hand it is a very perishable fruit and its delivery to distant points is restricted due to short shelf life at environmental temperature. Food irradiation process is applied to fruits for their preservation, once it promotes disinfestation and even maturation retard, among other mechanisms. The Brazilian legislation permits the food irradiation and does not restrict the doses to be delivered. In order to verify eventual changes, sensorial evaluation is very important to study how irradiation affects the quality of the fruit and its acceptability. Mangoes were irradiated in a Cobalto-60 source, from the Radiation Technology Center, CTR, of IPEN/CNEN-SP at doses 0,5 kGy e 0,75 kGy. The sensorial evaluation was measured through Acceptance Test where irradiated samples were offered together with control sample to the tasters who answered their perception through hedonic scale. The parameters Color, Odor, Flavor and Texture were analyzed. Statistical analysis showed that only Odor parameter was different from control (sample irradiated at 0.5 kGy). Few tasters indicated that irradiated mangoes had fewer odors in relation to non-irradiated samples. (author)

  2. MASM, a Matrine Derivative, Offers Radioprotection by Modulating Lethal Total-Body Irradiation-Induced Multiple Signaling Pathways in Wistar Rats

    Directory of Open Access Journals (Sweden)

    Jianzhong Li

    2016-05-01

    Full Text Available Matrine is an alkaloid extracted from Sophora flavescens Ait and has many biological activities, such as anti-inflammatory, antitumor, anti-fibrosis, and immunosuppressive properties. In our previous studies, the matrine derivative MASM was synthesized and exhibited potent inhibitory activity against liver fibrosis. In this study, we mainly investigated its protection against lethal total-body irradiation (TBI in rats. Administration of MASM reduced the radiation sickness characteristics and increased the 30-day survival of rats before or after lethal TBI. Ultrastructural observation illustrated that pretreatment of rats with MASM significantly attenuated the TBI-induced morphological changes in the different organs of irradiated rats. Gene expression profiles revealed that pretreatment with MASM had a dramatic effect on gene expression changes caused by TBI. Pretreatment with MASM prevented differential expression of 53% (765 genes of 1445 differentially expressed genes induced by TBI. Pathway enrichment analysis indicated that these genes were mainly involved in a total of 21 pathways, such as metabolic pathways, pathways in cancer, and mitogen-activated protein kinase (MAPK pathways. Our data indicated that pretreatment of rats with MASM modulated these pathways induced by TBI, suggesting that the pretreatment with MASM might provide the protective effects on lethal TBI mainly or partially through the modulation of these pathways, such as multiple MAPK pathways. Therefore, MASM has the potential to be used as an effective therapeutic or radioprotective agent to minimize irradiation damages and in combination with radiotherapy to improve the efficacy of cancer therapy.

  3. Consumer acceptance of irradiated food

    Energy Technology Data Exchange (ETDEWEB)

    Loaharanu, P. [Head, Food Preservation Section, Joint FAO/ IAEA Division of Nuclear Techniques in Food and Agriculture, Wagramerstr. 5, A-1400, Vienna (Austria)

    1997-12-31

    There was a widely held opinion during the 1970`s and 1980`s that consumers would be reluctant to purchase irradiated food, as it was perceived that consumers would confuse irradiated food with food contaminated by radionuclides. Indeed, a number of consumer attitude surveys conducted in several western countries during these two decades demonstrated that the concerns of consumers on irradiated food varied from very concerned to seriously concerned.This paper attempts to review parameters conducting in measuring consumer acceptance of irradiated food during the past three decades and to project the trends on this subject. It is believed that important lessons learned from past studies will guide further efforts to market irradiated food with wide consumer acceptance in the future. (Author)

  4. Irradiation of fresh fish

    Science.gov (United States)

    Yueh-jen, Yen; Jin-lai, Zhou; Shao-chun, Lai

    Occasionally, in China, marine products can not be provided for the markets in good quality, for during the time when they are being transported from the sea port to inland towns or even at the time when they are unloaded from the ship, they are beginning to spoil. Obviously, it is very important that appropiate measures should be taken to prevent them from decay. Our study has proved that the shelf life of fresh Flatfish (Cynoglossue robustus) and Silvery pomfret (stromateoides argenteus), which, packed in sealed containers, are irradiated by 1.5 kGy, 2.2 kGy and 3.0 kGy, can be stored for about 13-26 days at 3° - 5° C.

  5. Preliminary investigations into the bioconversion of gamma irradiated agricultural waste by Pleurotus spp.

    Science.gov (United States)

    Gbedemah, C. M.; Obodai, M.; Sawyerr, L. C.

    1998-06-01

    The application of gamma irradiation for pretreatment of lignocellulosic materials for their hydrolysis and to increase their digestibility for rumen animal have been reported in the literature. Gamma irradiation of corn stover in combination with sodium hydroxide for bioconversion of polysaccharide into protein by Pleurotus spp has also been reported. In this study experiments were designed to find out whether gamma radiation could serve both as a decontaminating agent as well as hydrolytic agent of sawdust for the bioconversion of four varieties of Pleurotus spp. Preliminary results indicate that a dose of 20kGy of gamma irradiation increase the yield of Pleurotus eous var ET-8 whilst decreasing the yield of other varieties.

  6. Irradiation for xenogeneic transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Halperin, E.C.; Knechtle, S.J.; Harland, R.C.; Yamaguchi, Yasua; Sontag, M.; Bollinger, R.R. (Duke Univ., Durham, NC (USA). Dept. of Radiology Duke Univ., Durham, NC (USA). Dept. of Microbiology and Immunology)

    1990-05-01

    Xenogeneic transplantation (XT) is the transplantation of organs or tissues from a member of one species to a member of another. Mammalian species frequently have circulating antibody which is directed against the foreign organ irrespective of known prior antigen exposure. This antibody may lead to hyperacute rejection once it ensues so efforts must be directed towards eliminating the pre-existing antibody. In those species in which hyperacute rejection of xenografts does not occur, cell-mediated refection, similar to allograft rejection, may occur. It is in the prevention of this latter form of refection that radiation is most likely to be beneficial in XT. Both total lymphoid irradiation (TLI) and selective lyphoid irradiation (LSI) have been investigated for use in conjunction with XT. TLI has contributed to the prolongation of pancreatic islet-cell xenografts from hamsters to rats. TLI has also markedly prolonged the survival of cardiac transplants from hamsters to rats. A more modest prolongation of graft survival has been seen with the use of TLI in rabbit-to-rat exchanges. Therapy with TLI, cyclosporine, and splenectomy has markedly prolonged the survival of liver transplants from hamsters to rats, and preliminary data suggest that TLI may contribute to the prolongation of graft survival in the transplantation of hearts from monkeys to baboons. SLI appears to have prolonged graft survival, when used in conjunction with anti-lymphocyte globulin, in hamster-to-rat cardiac graft exchanges. The current state of knowledge of the use of irradiaiton in experimental XT is reviewed. (author). 38 refs.; 1 fig.; 5 tabs.

  7. Understanding of alkaline pretreatment parameters for corn stover enzymatic saccharification

    Directory of Open Access Journals (Sweden)

    Chen Ye

    2013-01-01

    Full Text Available Abstract Background Previous research on alkaline pretreatment has mainly focused on optimization of the process parameters to improve substrate digestibility. To achieve satisfactory sugar yield, extremely high chemical loading and enzyme dosages were typically used. Relatively little attention has been paid to reduction of chemical consumption and process waste management, which has proven to be an indispensable component of the bio-refineries. To indicate alkali strength, both alkali concentration in pretreatment solution (g alkali/g pretreatment liquor or g alkali/L pretreatment liquor and alkali loading based on biomass solids (g alkali/g dry biomass have been widely used. The dual approaches make it difficult to compare the chemical consumption in different process scenarios while evaluating the cost effectiveness of this pretreatment technology. The current work addresses these issues through pretreatment of corn stover at various combinations of pretreatment conditions. Enzymatic hydrolysis with different enzyme blends was subsequently performed to identify the effects of pretreatment parameters on substrate digestibility as well as process operational and capital costs. Results The results showed that sodium hydroxide loading is the most dominant variable for enzymatic digestibility. To reach 70% glucan conversion while avoiding extensive degradation of hemicellulose, approximately 0.08 g NaOH/g corn stover was required. It was also concluded that alkali loading based on total solids (g NaOH/g dry biomass governs the pretreatment efficiency. Supplementing cellulase with accessory enzymes such as α-arabinofuranosidase and β-xylosidase significantly improved the conversion of the hemicellulose by 6–17%. Conclusions The current work presents the impact of alkaline pretreatment parameters on the enzymatic hydrolysis of corn stover as well as the process operational and capital investment costs. The high chemical consumption for alkaline

  8. Gamma irradiation of sun-dried apricots (Prunus armeniaca L.) for quality maintenance and quarantine purposes

    Energy Technology Data Exchange (ETDEWEB)

    Hussain, Peerzada R., E-mail: hussainpr@rediffmail.co [Astrophysical Science Division, Nuclear Research Laboratory, Bhabha Atomic Research Centre, Zakura, Srinagar, Kashmir-190006 (India); Meena, Raghuveer S.; Dar, Mohd A.; Wani, Ali M. [Astrophysical Science Division, Nuclear Research Laboratory, Bhabha Atomic Research Centre, Zakura, Srinagar, Kashmir-190006 (India)

    2011-07-15

    The study is aimed at the optimization of gamma irradiation treatment of sun-dried apricots for quality maintenance and quarantine purposes. Sun-dried apricots pre-treated with potassium meta-bisulphite (KMS) at 2.5% w/v were procured from progressive apricot grower of district Kargil, Ladakh region of Jammu and Kashmir state. The sun-dried apricots were packed in 250 gauge polyethylene packs and gamma irradiated in the dose range 1.0-3.0 kGy. The gamma irradiated fruit including control was stored under ambient (15{+-}2-25{+-}2 {sup o}C, RH 70-80%) conditions and periodically evaluated for physico-chemical, sensory and microbial quality parameters. Radiation treatment at dose levels of 2.5 and 3.0 kGy proved significantly (p{<=}0.05) beneficial in retention of higher levels of {beta}-carotene, ascorbic acid, total sugars and color values without impairing the taste as perceived by the sensory panel analysists. The above optimized doses retained the {beta}-carotene content of sun-dried apricots to the extent of 71.2% and 72.6% compared to 63.9% in control samples after 18 months of storage. Irradiation treatment facilitated the release of residual sulfur dioxide in KMS pre-treated sun-dried apricots significantly (p{<=}0.05) below the prescribed limit for dried products. During storage, two-fold decrease in sulfur dioxide content was recorded in irradiated samples (3.0 kGy) as compared to 16.9% in control. The above optimized doses besides maintaining the higher overall acceptability of sun-dried apricots resulted in 5 log reductions in microbial load just after irradiation and 1.0 and 1.3 log reductions in yeast and mold and bacterial count after 18 months of ambient storage.

  9. Techno-economic analysis of organosolv pretreatment process from lignocellulosic biomass

    DEFF Research Database (Denmark)

    Rodrigues Gurgel da Silva, Andrè; Errico, Massimiliano; Rong, Ben-Guang

    2018-01-01

    data, we propose a feasible process flowsheet for organosolv pretreatment. Simulation of the pretreatment process provided mass and energy balances for a techno-economic analysis, and the values were compared with the most prevalent and mature pretreatment method: diluted acid. Organosolv pretreatment...... in the sensitivity analysis turned into possible savings of 42.8% in the minimum ethanol selling price for organosolv pretreatment....

  10. Optimization of the dilute maleic acid pretreatment of wheat straw

    NARCIS (Netherlands)

    Kootstra, A.M.J.; Beeftink, H.H.; Scott, E.L.; Sanders, J.P.M.

    2009-01-01

    Background - In this study, the dilute maleic acid pretreatment of wheat straw is optimized, using pretreatment time, temperature and maleic acid concentration as design variables. A central composite design was applied to the experimental set up. The response factors used in this study are: (1)

  11. Coagulation pretreatment for ultrafiltration of deinking effluents containing flexographic inks

    Science.gov (United States)

    Bruno Chabot; Gopal A. Krishnagopalan; Said Abubakr

    1999-01-01

    This study was carried out to determine the potential of coagulation pretreatment with organic or inorganic coagulants to improve ultrafiltration performance during processing of wash deinking effluents containing flexographic inks. Wash filtrate effluents generated from mixtures of old flexographic and offset newspapers and old magazines were pretreated with a...

  12. 40 CFR 408.336 - Pretreatment standards for new sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for new sources. 408.336 Section 408.336 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT... Subcategory § 408.336 Pretreatment standards for new sources. Any new source subject to this subpart that...

  13. 40 CFR 421.336 - Pretreatment standards for new sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for new sources. 421.336 Section 421.336 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT... Subcategory § 421.336 Pretreatment standards for new sources. Except as provided in 40 CFR 403.7, any new...

  14. Synergistic Effect of Trehalose and Saccharose Pretreatment on ...

    African Journals Online (AJOL)

    Purpose: To investigate the synergistic effect of trehalose and saccharose pretreatment on maintenance of lyophilized human red blood cell (RBC) quality. Methods: RBCs were pre-treated with trehalose and saccharose, and then lyophilized and re-hydrated. Prior to lyophilization and after re hydration, RBC parameters, ...

  15. Quality evaluation of beverage produced from pre-treated tigernut ...

    African Journals Online (AJOL)

    Beverage samples from pretreated and untreated tigernut were evaluated for physical and chemical properties. Sensory evaluation of the beverage samples were carried out and the best preferred tigernutbeverage was compared with a popularly consumed beverage, soymilk. All the pre-treatments, except germination, ...

  16. Influence of pre-treatment on torrefaction of Phyllostachys edulis.

    Science.gov (United States)

    Xu, Xiwei; Jiang, Enchen; Lan, Xiang

    2017-09-01

    This study investigated the effects of different pre-treatments on structural changes in Phyllostachys edulis. Samples were pretreated with water, 15% ammonia water, 2% sulfuric acid, hydrothermal carbonization, and ball milling. Moreover, ultrasound was introduced. The influence of pre-treatment on the physiochemical property and composition of P. edulis were studied. Moreover, torrefaction characterization was performed and the distribution of torrefaction products of pretreated samples was determined. Results showed that pre-treatment effectively modified physiochemical structure and the torrefaction property of P. edulis. The pretreatment reduced the ash content and increased the bio-oil content of the torrefaction products. Compared with that of the raw material, the residual bio-char content of the pretreated samples decreased by 2-8%, and degradation temperature of bio-char fluctuated between 365°C and 321°C. The distribution of bio-oil contents, bio-char, and bio-gas in the torrefaction products significantly varied with pretreatments methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Structural Analysis of Alkaline Pretreated Rice Straw for Ethanol Production

    Directory of Open Access Journals (Sweden)

    Paripok Phitsuwan

    2017-01-01

    Full Text Available Rice straw (RS is an abundant, readily available agricultural waste, which shows promise as a potential feedstock for Asian ethanol production. To enhance release of glucose by enzymatic hydrolysis, RS was pretreated with aqueous ammonia (27% w/w at two pretreatment temperatures: room temperature and 60°C. Statistical analysis indicated similarity of enzymatic glucose production at both pretreatment temperatures after 3-day incubation. Chemical composition, FTIR, and EDX analyses confirmed the retention of glucan and xylan in the pretreated solid, but significant reduction of lignin (60.7% removal and silica. SEM analysis showed the disorganized surfaces and porosity of the pretreated RS fibers, thus improving cellulose accessibility for cellulase. The crystallinity index increased from 40.5 to 52.3%, indicating the higher exposure of cellulose. With 10% (w/v solid loadings of pretreated RS, simultaneous saccharification and fermentation yielded a final ethanol concentration of 24.6 g/L, corresponding to 98% of maximum theoretical yield. Taken together, aqueous ammonia pretreatment is an effective method to generate highly digestible pretreated RS for bioethanol production and demonstrates potential application in biorefinery industry.

  18. Effect of chemical pretreatment of some lignocellulosic wastes on ...

    African Journals Online (AJOL)

    Highest cellulase activity (0.06777 IU/ml/min) was display d by the organism grown on bagasse substrate pretreated with 2M NaOH for one hour. The proximate analysis of the cellulosic residues differed from one substrate to another, with the bagasse being the best. Pulverized substrates syndicated with alkali pretreatment ...

  19. Development of pretreatment of empty fruit bunches for enhanced ...

    African Journals Online (AJOL)

    Heating, boiling and steaming are among the physical agents and different concentrations of nitric acid, sulfuric acid and sodium hydroxide (NaOH) were the chemical agents used for the pretreatment of EFB to enhance the enzymatic saccharification of EFB. NaOH was proved to be the best among all the pretreatment ...

  20. 40 CFR 408.184 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for existing sources. 408.184 Section 408.184 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Hand-Butchered Salmon Processing Subcategory § 408.184 Pretreatment standards for existing sources. Any...

  1. 40 CFR 463.15 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Pretreatment standards for existing sources. 463.15 Section 463.15 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Heating Water Subcategory § 463.15 Pretreatment standards for existing sources. (a) PSES for bis(2...

  2. Influence of Chemical Pretreatment on the Quality of Dried Whole ...

    African Journals Online (AJOL)

    Chemical pretreatment of vegetables prior to drying is widely used to improve colour, texture and overall acceptability. Thus, this study investigated the effect of chemical pretreatment on some physico-chemical properties, colour and rehydration properties of dried red bell pepper. Fresh samples of whole red bell peppers ...

  3. Effect of combination pre-treatment on physicochemical, sensory ...

    African Journals Online (AJOL)

    Effect of combination pre-treatment on physicochemical, sensory and microbial characteristics of fresh aerobically stored minced goat (Black Bengal) meat organs. ... African Journal of Biotechnology ... However, acetic acid and glucose pretreatment controlled the fungal growth in meat samples most effectively. The

  4. Survival and growth of juvenile lost river suckers (Deltistes luxatus) challenged with a bacterial pathogen (Flavobacterium columnaris) during exposure to sublethal ammonia concentrations at pH 9.5

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — From 30 September to 1 December 1999, we tested survival and growth of Lost River suckers (Deltistes luxatus) that were exposed for 62 days to sublethal ammonia...

  5. Influence of LBE long term exposure and simultaneous fast neutron irradiation on the mechanical properties of T91 and 316L

    Energy Technology Data Exchange (ETDEWEB)

    Stergar, E., E-mail: estergar@sckcen.be [SCK-CEN, Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol (Belgium); Eremin, S.G. [RIAR, Research Institute of Atomic Reactors, Dimitrovgrad (Russian Federation); Gavrilov, S.; Lambrecht, M. [SCK-CEN, Belgian Nuclear Research Centre, Boeretang 200, 2400 Mol (Belgium); Makarov, O.; Iakovlev, V. [RIAR, Research Institute of Atomic Reactors, Dimitrovgrad (Russian Federation)

    2016-05-15

    The LEXUR–II–LBE irradiation campaign was conducted from 2011 to 2012 and was aimed to investigate the combined influence of irradiation and LBE environment. In this irradiation campaign tensile test samples, pressurized tubes and corrosion samples were irradiated in LBE filled capsules. To separate the effect of exposure to LBE and neutron irradiation a parallel furnace experiment where the samples were exposed to LBE at the irradiation temperature for the corresponding time was conducted. Here we report results of the first extracted capsule which was irradiated about 6 months and dismantled after a cooling phase to decrease activity. The results of SSRT tests for irradiated T91 show that the exposure to LBE at 350 °C for a long time leads to the appearance of liquid metal embrittlement without any pre-treatment which is usually necessary to promote LME. Irradiation increases the effect of LME on the ductility of T91. In contrast to the findings for T91 the gained results also show that tensile tests on irradiated austenitic stainless steel 316L show no influence of LBE environment on the tensile properties.

  6. Electrohydrolysis pretreatment of water hyacinth for enhanced hydrolysis.

    Science.gov (United States)

    Barua, Visva Bharati; Raju, V Wilson; Lippold, Sophia; Kalamdhad, Ajay S

    2017-08-01

    This study investigates the use of electrohydrolysis pretreatment on water hyacinth to cut short the hydrolysis step and increase biogas production at the same time. Electrohydrolysis pretreatment of water hyacinth at 20V for 60min exhibited improved solubilisation (42.9%). Therefore, bio-chemical methane potential (BMP) test was carried out between water hyacinth pretreated at 20V for 60min and untreated water hyacinth. By the end of 30days, cumulative methane production of 2455±17mL CH4/g VS for electrohydrolysis pretreated substrate and 1936±27mL CH4/g VS for the untreated substrate was achieved. Compositional analysis and characterization study revealed the efficiency of electrohydrolysis pretreatment in melting the lignin and lowering the cellulose crystallinity of water hyacinth. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Bioethanol from lignocellulose - pretreatment, enzyme immobilization and hydrolysis kinetics

    DEFF Research Database (Denmark)

    Tsai, Chien Tai

    , the cost of enzyme is still the bottle neck, re-using the enzyme is apossible way to reduce the input of enzyme in the process. In the point view of engineering, the prediction of enzymatic hydrolysis kinetics under different substrate loading, enzyme combination is usful for process design. Therefore....... Ionic liquid had been reported to be able to dissolve lignocellulose. However, as our knowledge, in all published researches, the concentration of lignocellulose in ionic liquid were low (5~10%). Besides, pretreatment time were long (from 1 hr to 1 day). Based on the hypothesis that the amount of ionic...... liquid and pretreatment time can be reduced, the influence of substrate concentration, pretreatment time and temperature were investigated and optimized. Pretreatment of barley straw by [EMIM]Ac, correlative models were constructed using 3 different pretreatment parameters (temperature, time...

  8. Dielectric barrier discharge plasma pretreatment on hydrolysis of microcrystalline cellulose

    Science.gov (United States)

    Huang, Fangmin; Long, Zhouyang; Liu, Sa; Qin, Zhenglong

    2017-04-01

    Dielectric barrier discharge (DBD) plasma was used as a pretreatment method for downstream hydrolysis of microcrystalline cellulose (MCC). The degree of polymerization (DP) of MCC decreased after it was pretreated by DBD plasma under a carrier gas of air/argon. The effectiveness of depolymerization was found to be influenced by the crystallinity of MCC when under the pretreatment of DBD plasma. With the addition of tert-butyl alcohol in the treated MCC water suspension solution, depolymerization effectiveness of MCC was inhibited. When MCC was pretreated by DBD plasma for 30 min, the total reducing sugar concentration (TRSC) and liquefaction yield (LY) of pretreated-MCC (PMCC) increased by 82.98% and 34.18% respectively compared with those for raw MCC.

  9. AFIP-4 Irradiation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Danielle M Perez; Misti A Lillo; Gray S. Chang; Glenn A Roth; Nicolas Woolstenhulme; Daniel M Wachs

    2011-09-01

    The Advanced Test Reactor (ATR) Full size plate In center flux trap Position (AFIP) experiment AFIP-4 was designed to evaluate the performance of monolithic uranium-molybdenum (U-Mo) fuels at a scale prototypic of research reactor fuel plates. The AFIP-4 test further examine the fuel/clad interface and its behavior under extreme conditions. After irradiation, fission gas retention measurements will be performed during post irradiation (PIE). The following report summarizes the life of the AFIP-4 experiment through end of irradiation, including a brief description of the safety analysis, as-run neutronic analysis results, hydraulic testing results, and thermal analysis results.

  10. AFIP-4 Irradiation Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Danielle M Perez; Misti A Lillo; Gray S. Chang; Glenn A Roth; Nicolas Woolstenhulme; Daniel M Wachs

    2012-01-01

    The Advanced Test Reactor (ATR) Full size plate In center flux trap Position (AFIP) experiment AFIP-4 was designed to evaluate the performance of monolithic uranium-molybdenum (U-Mo) fuels at a scale prototypic of research reactor fuel plates. The AFIP-4 test further examine the fuel/clad interface and its behavior under extreme conditions. After irradiation, fission gas retention measurements will be performed during post irradiation (PIE)1,2. The following report summarizes the life of the AFIP-4 experiment through end of irradiation, including a brief description of the safety analysis, as-run neutronic analysis results, hydraulic testing results, and thermal analysis results.

  11. Craniospinal Irradiation for Trilateral Retinoblastoma Following Ocular Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Marks, Lawrence B.; Bentel, Gunilla; Sherouse, George W.; Spencer, David P.; Light, Kim

    2015-01-15

    A case study is presented. Craniospinal radiotherapy and a three-field pineal boost for trilateral retinoblastoma were delivered to a patient previously irradiated for ocular retinoblastoma. The availability of CT-based three-dimensional treatment planning provided the capability of identifying the previously irradiated volume as a three-dimensional anatomic structure and of designing a highly customized set of treatment beams that minimized reirradiation of that volume.

  12. Quantifying sublethal effects of glyphosate and Roundup® to Daphnia magna using a fluorescence based enzyme activity assay and video tracking

    DEFF Research Database (Denmark)

    Roslev, Peter; R. Hansen, Lone; Ørsted, Michael

    Glyphosate (N-(phosphonomethyl)glycine) is the active ingredient in a range of popular broad-spectrum, non-selective herbicide formulations. The toxicity of this herbicide to non-target aquatic organisms such as Daphnia magna is often evaluated using conventional toxicity assays that focus...... on endpoints such as immobility and mortality. In this study, we investigated sublethal effects of glyphosate and Roundup® to D. magna using video tracking for quantifying behavioral changes, and a novel fluorescence based assay for measuring in vivo hydrolytic enzyme activity (FLEA assay). Roundup® exposure...... resulted in concentration-dependent inhibition of alkaline phosphatase activity in D. magna. The inhibition of alkaline phosphatase by Roundup® was temperature-dependent with lowest inhibition at 14 °C and greater inhibition at 20 and 26 °C. Exposure of D. magna to sublethal concentrations of glyphosate...

  13. Expression of liver functions following sub-lethal and non-lethal doses of allyl alcohol and acetaminophen in the rat

    DEFF Research Database (Denmark)

    Tygstrup, N; Jensen, S A; Krog, B

    1997-01-01

    synthesis, and for proteins related to liver regeneration. RESULTS: After allyl alcohol, mRNA of "positive" acute phase proteins was higher than after acetaminophen and increased with the dose, whereas after acetaminophen it decreased with the dose. The mRNA of the urea cycle enzymes and glutamine...... cycle enzymes, whereas that of the rate limiting enzymes carbamoylphosphate synthase and argininosuccinate synthetase was increased by the non-lethal but not by the sub-lethal dose of acetaminophen. The expression of the cell-cycle dependent proteins was more suppressed after the sub-lethal than after......BACKGROUND/AIMS: To relate severity of intoxication with allyl alcohol and acetaminophen to modulated hepatic gene expression of liver functions and regeneration. METHODS: Rats fasted for 12 h received acetaminophen 3.5 or 5.6 g per kg body weight, or allyl alcohol 100 or 125 microl by gastric tube...

  14. Unbiased high-throughput characterization of mussel transcriptomic responses to sublethal concentrations of the biotoxin okadaic acid

    Science.gov (United States)

    Suarez-Ulloa, Victoria; Fernandez-Tajes, Juan; Aguiar-Pulido, Vanessa; Prego-Faraldo, M. Veronica; Florez-Barros, Fernanda; Sexto-Iglesias, Alexia; Mendez, Josefina

    2015-01-01

    Background. Harmful Algal Blooms (HABs) responsible for Diarrhetic Shellfish Poisoning (DSP) represent a major threat for human consumers of shellfish. The biotoxin Okadaic Acid (OA), a well-known phosphatase inhibitor and tumor promoter, is the primary cause of acute DSP intoxications. Although several studies have described the molecular effects of high OA concentrations on sentinel organisms (e.g., bivalve molluscs), the effect of prolonged exposures to low (sublethal) OA concentrations is still unknown. In order to fill this gap, this work combines Next-Generation sequencing and custom-made microarray technologies to develop an unbiased characterization of the transcriptomic response of mussels during early stages of a DSP bloom. Methods. Mussel specimens were exposed to a HAB episode simulating an early stage DSP bloom (200 cells/L of the dinoflagellate Prorocentrum lima for 24 h). The unbiased characterization of the transcriptomic responses triggered by OA was carried out using two complementary methods of cDNA library preparation: normalized and Suppression Subtractive Hybridization (SSH). Libraries were sequenced and read datasets were mapped to Gene Ontology and KEGG databases. A custom-made oligonucleotide microarray was developed based on these data, completing the expression analysis of digestive gland and gill tissues. Results. Our findings show that exposure to sublethal concentrations of OA is enough to induce gene expression modifications in the mussel Mytilus. Transcriptomic analyses revealed an increase in proteasomal activity, molecular transport, cell cycle regulation, energy production and immune activity in mussels. Oppositely, a number of transcripts hypothesized to be responsive to OA (notably the Serine/Threonine phosphatases PP1 and PP2A) failed to show substantial modifications. Both digestive gland and gill tissues responded similarly to OA, although expression modifications were more dramatic in the former, supporting the choice of

  15. Unbiased high-throughput characterization of mussel transcriptomic responses to sublethal concentrations of the biotoxin okadaic acid

    Directory of Open Access Journals (Sweden)

    Victoria Suarez-Ulloa

    2015-11-01

    Full Text Available Background. Harmful Algal Blooms (HABs responsible for Diarrhetic Shellfish Poisoning (DSP represent a major threat for human consumers of shellfish. The biotoxin Okadaic Acid (OA, a well-known phosphatase inhibitor and tumor promoter, is the primary cause of acute DSP intoxications. Although several studies have described the molecular effects of high OA concentrations on sentinel organisms (e.g., bivalve molluscs, the effect of prolonged exposures to low (sublethal OA concentrations is still unknown. In order to fill this gap, this work combines Next-Generation sequencing and custom-made microarray technologies to develop an unbiased characterization of the transcriptomic response of mussels during early stages of a DSP bloom.Methods. Mussel specimens were exposed to a HAB episode simulating an early stage DSP bloom (200 cells/L of the dinoflagellate Prorocentrum lima for 24 h. The unbiased characterization of the transcriptomic responses triggered by OA was carried out using two complementary methods of cDNA library preparation: normalized and Suppression Subtractive Hybridization (SSH. Libraries were sequenced and read datasets were mapped to Gene Ontology and KEGG databases. A custom-made oligonucleotide microarray was developed based on these data, completing the expression analysis of digestive gland and gill tissues.Results. Our findings show that exposure to sublethal concentrations of OA is enough to induce gene expression modifications in the mussel Mytilus. Transcriptomic analyses revealed an increase in proteasomal activity, molecular transport, cell cycle regulation, energy production and immune activity in mussels. Oppositely, a number of transcripts hypothesized to be responsive to OA (notably the Serine/Threonine phosphatases PP1 and PP2A failed to show substantial modifications. Both digestive gland and gill tissues responded similarly to OA, although expression modifications were more dramatic in the former, supporting the

  16. Behavioral responses of the estuarine calanoid copepod Eurytemora affinis to sub-lethal concentrations of waterborne pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Michalec, François-Gaël [Université Lille Nord de France, F-59000 Lille (France); USTL, LOG, Station Marine de Wimereux, F-62930 Wimereux (France); CNRS, UMR 8187, F-62930 Wimereux (France); National Taiwan Ocean University, Institute of Marine Biology, Keelung, Taiwan, ROC (China); Holzner, Markus [Institute of Environmental Engineering, ETH Zürich (Switzerland); Menu, Dominique [Université Lille Nord de France, F-59000 Lille (France); USTL, LOG, Station Marine de Wimereux, F-62930 Wimereux (France); CNRS, UMR 8187, F-62930 Wimereux (France); Hwang, Jiang-Shiou [National Taiwan Ocean University, Institute of Marine Biology, Keelung, Taiwan, ROC (China); Souissi, Sami, E-mail: sami.souissi@univ-lille1.fr [Université Lille Nord de France, F-59000 Lille (France); USTL, LOG, Station Marine de Wimereux, F-62930 Wimereux (France); CNRS, UMR 8187, F-62930 Wimereux (France)

    2013-08-15

    Highlights: •We studied the effects of sub-lethal exposure to pollutants on Eurytemora affinis swimming behavior. •Nonylphenol, cadmium and polycyclic aromatic hydrocarbons caused hyperactivity. •Effects were observable within 30 min of exposure and persisted during a depuration period. •The response resembles an escape reaction allowing copepods to evade stressful conditions. -- Abstract: Estuarine waters contain a variety of chemicals which affect to various extents the behavior of aquatic organisms. Little is known, however, on the behavioral response of copepods. The present study shows the results of laboratory experiments investigating the immediate effects of sub-lethal concentrations of three commonly found contaminants on the three-dimensional swimming behavior of the estuarine calanoid copepod Eurytemora affinis. Nonylphenol at 2 μg L{sup −1}, cadmium at 45 ng L{sup −1} and a mixture of low to medium molecular weight polycyclic aromatic hydrocarbons at 40 ng L{sup −1} all affected the swimming behavior of E. affinis adults, increasing both swimming speed and activity. In most cases, effects were observable within 30 min of exposure and persisted or faded during a period of depuration in uncontaminated water of similar duration. In ovigerous females exposed to Cd and PAHs, effects appeared to be more pronounced during the depuration period, suggesting that carrying ovisacs may impair recovery. We quantified differences in the distribution of swimming speed values by considering the relative frequencies of periods of break, slow and fast swimming and we observed a trend toward faster movements in the presence of pollutants. The degree of trajectory complexity, estimated through their fractal dimension, was unaffected by pollutants. Since both narcotic and non-narcotic pollutants induced hyperactivity, our results suggest that changes in behavior after a short-term exposure may be independent of the general mode of action of the chemicals. The

  17. Maternal transfer and sublethal immune system effects of brevetoxin exposure in nesting loggerhead sea turtles (Caretta caretta) from western Florida.

    Science.gov (United States)

    Perrault, Justin R; Bauman, Katherine D; Greenan, Taylor M; Blum, Patricia C; Henry, Michael S; Walsh, Catherine J

    2016-11-01

    Blooms of Karenia brevis (also called red tides) occur almost annually in the Gulf of Mexico. The health effects of the neurotoxins (i.e., brevetoxins) produced by this toxic dinoflagellate on marine turtles are poorly understood. Florida's Gulf Coast represents an important foraging and nesting area for a number of marine turtle species. Most studies investigating brevetoxin exposure in marine turtles thus far focus on dead and/or stranded individuals and rarely examine the effects in apparently "healthy" free-ranging individuals. From May-July 2014, one year after the last red tide bloom, we collected blood from nesting loggerhead sea turtles (Caretta caretta) on Casey Key, Florida USA. These organisms show both strong nesting and foraging site fidelity. The plasma was analyzed for brevetoxin concentrations in addition to a number of health and immune-related parameters in an effort to establish sublethal effects of this toxin. Lastly, from July-September 2014, we collected unhatched eggs and liver and yolk sacs from dead-in-nest hatchlings from nests laid by the sampled females and tested these samples for brevetoxin concentrations to determine maternal transfer and effects on reproductive success. Using a competitive enzyme-linked immunosorbent assay (ELISA), all plasma samples from nesting females tested positive for brevetoxin (reported as ng brevetoxin-3[PbTx-3] equivalents [eq]/mL) exposure (2.1-26.7ng PbTx-3eq/mL). Additionally, 100% of livers (1.4-13.3ng PbTx-3eq/mL) and yolk sacs (1.7-6.6ng PbTx-3eq/mL) from dead-in-nest hatchlings and 70% of eggs (<1.0-24.4ng PbTx-3eq/mL) tested positive for brevetoxin exposure with the ELISA. We found that plasma brevetoxin concentrations determined by an ELISA in nesting females positively correlated with gamma-globulins, indicating a potential for immunomodulation as a result of brevetoxin exposure. While the sample sizes were small, we also found that plasma brevetoxin concentrations determined by an ELISA in

  18. (Irradiation creep of graphite)

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, C.R.

    1990-12-21

    The traveler attended the Conference, International Symposium on Carbon, to present an invited paper, Irradiation Creep of Graphite,'' and chair one of the technical sessions. There were many papers of particular interest to ORNL and HTGR technology presented by the Japanese since they do not have a particular technology embargo and are quite open in describing their work and results. In particular, a paper describing the failure of Minor's law to predict the fatigue life of graphite was presented. Although the conference had an international flavor, it was dominated by the Japanese. This was primarily a result of geography; however, the work presented by the Japanese illustrated an internal program that is very comprehensive. This conference, a result of this program, was better than all other carbon conferences attended by the traveler. This conference emphasizes the need for US participation in international conferences in order to stay abreast of the rapidly expanding HTGR and graphite technology throughout the world. The United States is no longer a leader in some emerging technologies. The traveler was surprised by the Japanese position in their HTGR development. Their reactor is licensed and the major problem in their graphite program is how to eliminate it with the least perturbation now that most of the work has been done.

  19. Stillbirths and male irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Boice, John D. Jr. [International Epidemiology Institute, Rockville, MD (United States)]. E-mail: boicej@compuserve.com; Robison, Leslie L. [University of Minnesota, Minneapolis, MN (United States); Mertens, Ann [University of Texas M D Anderson Cancer Center, Houston, TX (United States); Stovall, Marilyn; Green, Daniel M.; Mulvihill, John J.; ); Roswell Park Cancer Institute, Buffalo, NY (United States); University of Oklahoma, Oklahoma City, OK (US))

    2000-09-01

    Little (1999) recently reviewed the evidence that paternal preconception irradiation in the Sellafield workforce (Parker et al 1999) and among Japanese atomic bomb survivors (Otake et al 1990) might be associated with an increased risk of stillbirth. He concluded that the association reported for radiation workers was statistically incompatible with the absence of an association seen among the exposed Japanese parents. These studies and analyses illustrate the considerable difficulty in assessing stillbirths conceived by men exposed to ionising radiation at work. For example, occupational doses may not be sufficiently large to result in a detectable effect and maternal factors that are associated with stillbirths and important to adjust for may not be available. These papers also bring to focus a relevant but not well-studied public health issue, namely, what are the reproductive risks for men and women exposed to potential mutagens? We wish to emphasise here the theoretical and practical advantages of addressing this issue in persons not with low dose occupational or acute atomic bomb exposures, but with higher dose medical experiences; in particular, in survivors of cancers of childhood, adolescents, and young adulthood (Blatt 1999, Bryne et al 1998, Sankila et al 1998, Green et al 1997, Hawkins and Stevens 1996). Letter-to-the-editor.

  20. Delignification of Sawdust White Teak (Gmelina arborea Roxb. by Fungi Phanerochaete chrysosporium Irradiated Gamma Ray

    Directory of Open Access Journals (Sweden)

    Nurhasni Nurhasni

    2016-12-01

    Full Text Available Abstrak Biomassa lignoselulosa yang merupakan limbah pemanenan kayu harus dilakukan proses untuk memisahkan selulosa, hemiselulosa dan lignin sehingga dapat termanfaatkan. Penelitian ini bertujuan untuk mengetahui efektivitas inokulan fungi Phanerochaete chrysosporium iradiasi gamma dan pretreatment kimia terhadap percepatan delignifikasi serbuk kayu jati putih (Gmelina arborea Roxb. sehingga dapat dimanfaatkan dalam proses pulping. Pada penelitian ini dilakukan pretreatment substrat kayu jati putih (Gmelina arborea Roxb. menggunakan larutan NaOH 1% dan H2SO4 1% serta iradiasi gamma Co-60, yang mempunyai daya ionisasi kecil, daya tembus yang tinggi serta Co-60 dapat memancarkan sinar gamma dengan waktu paruh pendek. Penelitian ini dilakukan dalam dua tahap, tahap pertama penentuan dosis optimum iradiasi gamma terhadap fungi Phanerochaete chrysosporium (0 Gy, 200 Gy, 400 Gy, 600 Gy, 800 Gy, dan 1000 Gy dan tahap kedua analisis karakteristik substrat kayu jati putih yang telah di pretreatment dengan metode Solid State Fermentation (SSF selama 21 hari. Hasil penelitian menunjukkan bahwa dosis optimum pemberian iradiasi gamma pada fungi Phanerochaete chrysosporium yaitu pada dosis 600 Gy yang dapat meningkatkan aktivitas enzim lignin peroksidase (LiP sebesar 22.18 U/mL. Proses pretreatment kimia dengan menggunakan H2SO4 1% dapat mempercepat proses biodelignifikasi yang menghasilkan efisiensi degradasi lignin tertinggi yaitu sebesar 25.65%.   Kata kunci: Lignoselulosa, delignifikasi, Solid State Fermentation (SSF, Phanerochaete chrysosporium,iradiasi gamma.   Abstract   Lignocellulose biomass is waste wood harvesting should be a process for separating cellulose, hemicellulose and lignin that can be utilized. This study aims to determine the effectiveness of the inoculant fungi Phanerochaete chrysosphorium gamma irradiation and chemical pretreatment to accelerate delignification powder white teak (Gmelina arborea Roxb.. In this research

  1. Synergistic effect of UV pretreated Fe-ZSM-5 catalysts for heterogeneous catalytic complete oxidation of VOC: A technology development for sustainable use.

    Science.gov (United States)

    Aziz, Abdul; Kim, Kwang Soo

    2017-10-15

    In this work, the performance of benzene, toluene, ethylbenzene, and xylene (BTEX) removal and degradation from gas, air streams on UV pretreated Fe-ZSM-5 in a batch reactor at room temperature were studied. The Fe-ZSM-5 zeolite catalyst was prepared by hydrothermal reaction method. The influence of UV pre-irradiation time on the removal of BTEX were assessed by varying the time, ranging from 15min to 60smin. Then, sustainability of the activation of the catalyst resulted by UV pretreatment was studied by the four-cycle experiment with one time UV irradiation and after each cycle irradiation followed by BTEX removal after every cycle respectively. The results of BTEX removal depicted that 30min of UV pretreatment was sufficient for complete organics removal. The UV pretreatment effect on the catalytic oxidation and the stability of the catalyst were studied by modern instrumental techniques. The novelty of the process was the sustainable reuse of catalyst with persistent VOC removal, which works on the -adsorption-oxidation-regeneration-adsorption- cycle, which was confirmed by the characterization studies of the catalyst after four runs. The results revealed that the change in the structure, stability, morphology, and removal efficiency of the catalyst during the experiments was negligible. The VOC degradation mechanism studies showed that the oxidation occurs due to the formation of free radicals as well as hydroxyl ions, so named it heterogeneous photo-Fenton oxidation. The residual materials analysis showed the complete mineralization of VOC except small amount of acetone as oxidation product. Lastly, the kinetics of the VOC removal was studied. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Sublethal red tide toxin exposure in free-ranging manatees (Trichechus manatus) affects the immune system through reduced lymphocyte proliferation responses, inflammation, and oxidative stress

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Catherine J., E-mail: cjwalsh@mote.org [Marine Immunology Program, Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236 (United States); Butawan, Matthew, E-mail: mattbutawan@outlook.com [Marine Immunology Program, Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236 (United States); Yordy, Jennifer, E-mail: jennifer.e.balmer@gmail.com [Marine Immunology Program, Mote Marine Laboratory, 1600 Ken Thompson Parkway, Sarasota, FL 34236 (United States); Ball, Ray, E-mail: Ray.Ball@lowryparkzoo.com [Lowry Park Zoo, 1101 W Sligh Ave, Tampa, FL 33604 (United States); Flewelling, Leanne, E-mail: Leanne.Flewelling@MyFWC.com [Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, 100 8th Ave SE, St. Petersburg, FL 33701 (United States); Wit, Martine de, E-mail: Martine.deWit@MyFWC.com [Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, 100 8th Ave SE, St. Petersburg, FL 33701 (United States); Bonde, Robert K., E-mail: rbonde@usgs.gov [U.S. Geological Survey, Sirenia Project, 7920 NE 71st Street, Gainesville, FL 32653 (United States)

    2015-04-15

    Highlights: • Sublethal brevetoxin exposure affects manatee immune function. • Plasma brevetoxin levels correlate with oxidative stress in rescued manatees. • Brevetoxin exposure affects lymphocyte proliferation in rescued manatees. • Plasma brevetoxin concentrations ranged from 0 to 19 ng PbTx-3 eq/mL. - Abstract: The health of many Florida manatees (Trichechus manatus latirostris) is adversely affected by exposure to blooms of the toxic dinoflagellate, Karenia brevis. K. brevis blooms are common in manatee habitats of Florida’s southwestern coast and produce a group of cyclic polyether toxins collectively referred to as red tide toxins, or brevetoxins. Although a large number of manatees exposed to significant levels of red tide toxins die, several manatees are rescued from sublethal exposure and are successfully treated and returned to the wild. Sublethal brevetoxin exposure may potentially impact the manatee immune system. Lymphocyte proliferative responses and a suite of immune function parameters in the plasma were used to evaluate effects of brevetoxin exposure on health of manatees rescued from natural exposure to red tide toxins in their habitat. Blood samples were collected from rescued manatees at Lowry Park Zoo in Tampa, FL and from healthy, unexposed manatees in Crystal River, FL. Peripheral blood leukocytes (PBL) isolated from whole blood were stimulated with T-cell mitogens, ConA and PHA. A suite of plasma parameters, including plasma protein electrophoresis profiles, lysozyme activity, superoxide dismutase (SOD) activity, and reactive oxygen/nitrogen (ROS/RNS) species, was also used to assess manatee health. Significant decreases (p < 0.05) in lymphocyte proliferation were observed in ConA and PHA stimulated lymphocytes from rescued animals compared to non-exposed animals. Significant correlations were observed between oxidative stress markers (SOD, ROS/RNS) and plasma brevetoxin concentrations. Sublethal exposure to brevetoxins in the

  3. Effects of whole body x-irradiation and cyclophosphamide treatment on induction of macrophage tumoricidal function in mice

    Energy Technology Data Exchange (ETDEWEB)

    Schultz, R.M.; Pavlidis, N.A.; Chirigos, M.A.; Weiss, J.F.

    1978-07-01

    The influence of whole-body x irradiation (200 to 800 R) and subcutaneous cyclophosphamide (CY) treatment (150 to 500 mg/kg) was studied on the ability of adjuvants to induce cytotoxic macrophages in vivo. Surprisingly, radiation or CY therapy alone produced growth inhibitory macrophages whose function peaked within 2 days after treatment. When adjuvants such as Bacillus Calmette Guerin (BCG), pyran copolymer, or glucan were administered ip within 2 hr after sublethal (600 R) x irradiation, adjuvant-induced cytotoxic function was depressed but not ablated. In addition, when noninduced peritoneal macrophages were obtained 6 days after lethal (800 R) x irradiation, their ability to be activated in vitro by lymphokine or fibroblast-derived interferon preparations was only slightly depressed at all concentrations of inducer tested. When BCG, pyran, or glucan was administered ip concurrently with sc CY treatment, only the ability of BCG to activate macrophages was markedly reduced, indicating separate mechanisms for the induction of tumoricidal macrophages. A better understanding of the interaction of chemotherapeutic and/or radiation regimens with adjuvants which affect macrophage function may be instrumental to rationalized immunotherapy protocols.

  4. UV irradiance radiometers calibration procedure

    OpenAIRE

    Doctorovich I. V.; Butenko V. K.; Hodovaniouk V. N.; Fodchuk I. M.; Yuriev V. G.

    2008-01-01

    The paper deals with the problems arising at calibration of narrow-band spectral-sensitive radiometers. The procedure of irradiance unit transfer to UV radiometers — UV radiometers calibration procedure — is presented.

  5. URAM-2 Cryogenic Irradiation Facility

    CERN Document Server

    Shabalin, E P; Kulikov, S A; Kulagin, E N; Melihov, V V; Belyakov, A A; Golovanov, L B; Borzunov, Yu T; Konstantinov, V I; Androsov, A V

    2002-01-01

    The URAM-2 irradiation facility has been built and mounted at the channel No. 3 of the IBR-2 reactor. It was constructed for study of radiolysis effects by fast neutron irradiation in some suitable for effective cold neutron production materials (namely: solid methane, methane hydrate, water ice, etc.). The facility cooling system is based on using liquid helium as a coolant material. The original charging block of the rig allows the samples to be loaded by condensing gas into irradiation cavity or by charging beads of ice prepared before. Preliminary tests for each facility block and assembling them at the working position were carried out. Use of the facility for study accumulation of chemical energy under irradiation at low temperature in materials mentioned above and its spontaneous release was started.

  6. Culture of the green microalga Botryococcus braunii Showa with LED irradiation eliminating violet light enhances hydrocarbon production and recovery.

    Science.gov (United States)

    Atobe, Sueko; Saga, Kiyotaka; Maeyama, Haruko; Fujiwara, Kazuhiro; Okada, Shigeru; Imou, Kenji

    2014-01-01

    The green microalga Botryococcus braunii (B. braunii), race B, was cultured under light-emitting diode (LED) irradiation with and without violet light. This study examined the effect of violet light on hydrocarbon recovery and production in B. braunii. C34 botryococcene hydrocarbons were efficiently extracted by thermal pretreatments at lower temperatures when the alga was cultured without violet light. The hydrocarbon content was also higher (approximately 3%) in samples cultured without violet light. To elucidate the mechanism of effective hydrocarbon recovery and production, we examined structural components of the extracellular matrix (ECM). The amounts of extracellular carotenoids and water-soluble polymers extracted by thermal pretreatment from the ECM were decreased when the alga was cultured without violet light. These results indicate that LED irradiation without violet light is more effective for hydrocarbon recovery and production in B. braunii. Furthermore, structural ECM components are closely involved in hydrocarbon recovery and production in B. braunii.

  7. Development and application of long-term sublethal whole sediment tests with Arenicola marina and Corophium volutator using Ivermectin as the test compound

    Energy Technology Data Exchange (ETDEWEB)

    Allen, Yvonne T. [Centre for Environment, Fisheries and Aquaculture Science, Burnham Laboratory, Remembrance Avenue, Burnham-on-Crouch, Essex, CM0 8HA (United Kingdom)]. E-mail: yvonne.allen@cefas.co.uk; Thain, John E. [Centre for Environment, Fisheries and Aquaculture Science, Burnham Laboratory, Remembrance Avenue, Burnham-on-Crouch, Essex, CM0 8HA (United Kingdom); Haworth, Sarah [Centre for Environment, Fisheries and Aquaculture Science, Burnham Laboratory, Remembrance Avenue, Burnham-on-Crouch, Essex, CM0 8HA (United Kingdom); Barry, Jon [Centre for Environment, Fisheries and Aquaculture Science, Burnham Laboratory, Remembrance Avenue, Burnham-on-Crouch, Essex, CM0 8HA (United Kingdom)

    2007-03-15

    Short-term whole sediment tests using the amphipod Corophium volutator and the polychaete Arenicola marina are now routinely used in Europe to assess the acute toxicity of marine sediments. However, there is still a need to develop longer-term assays which measure effects on sublethal endpoints that are more relevant to predicting impacts at the population level. The effect of increasing exposure times and measuring additional endpoints such as growth, on the sensitivity of these assays was investigated. The test compound used was the chemotherapeutant Ivermectin (IVM), used in aquaculture to treat sea lice infestations. IVM was found to be acutely toxic to both test organisms. Extending the lugworm test to 100 days increased sensitivity of survival by a factor of three; a significant reduction in casting rate was observed at concentrations an order of magnitude lower. This assay shows potential for detecting the sublethal effects of low concentrations of sediment contaminants. Increasing the exposure time did not seem to affect the sensitivity of the amphipod, but further method development is required. - Long-term sublethal sediment tests are more sensitive than standard acute tests when assessing the toxic effects of Ivermectin.

  8. Investigation into the potential of sub-lethal photodynamic antimicrobial chemotherapy (PACT) to reduce susceptibility of meticillin-resistant Staphylococcus aureus (MRSA) to antibiotics

    Science.gov (United States)

    Cassidy, C. M.; Donnelly, R. F.; Tunney, M. M.

    2009-06-01

    In PACT, a combination of a sensitising drug and visible light cause the selective destruction of microbial cells via singlet oxygen production. As singlet oxygen is a non-specific oxidizing agent and is only present during illumination, development of resistance to this treatment is thought to be unlikely. However, in response to oxidative stress, bacteria can up-regulate oxidative stress genes and associated antibiotic resistance genes. The up-regulation of these genes and potential transfer of genetic material may result in a resistant bacterial population. This study determined whether treatment of clinically isolated meticillin resistant Staphylococcus aureus (MRSA) strains with sub-lethal doses of methylene blue (MB) and meso-tetra (N-methyl-4-pyridyl) porphine tetra tosylate (TMP)-PACT resulted in reduced susceptibility to antibiotics and previously lethal PACT. Exposure of strains to sub-lethal doses of photosensitizer in combination with light had no effect on susceptibility to previously lethal photosensitization. Furthermore, exposure to sub-lethal concentrations of both photosensitizers caused no significant changes in the minimum inhibitory concentration (MIC) for each strain tested. Any differences in susceptibility were not significant as they did not cross breakpoints between resistant and susceptible for any organism or antibiotic tested. Therefore, PACT remains an attractive alternative option for treatment of MRSA infections.

  9. Chronic sublethal effects of San Francisco Bay sediments on nereis (neanthes) arenaceodentata; effect of food ration on sediment toxicity. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Moore, D.W.; Dillon, T.M.

    1993-09-01

    This report is designed to address concerns regarding the effect of food ration on toxicity during chronic sublethal sediment bioassays. To this end, a contaminated San Francisco Bay sediment and a clean control sediment were evaluated in a chronic sublethal test under a series of different food rations, with the marine polychaete worm Nereis (Neanthes) arenaceodentata. Animals were exposed from early juvenile stage through the onset of gametogenesis. Treatments were 2.OX, 1.OX, 0.5X, and 0.25X where X is the recommended food ration for laboratory cultures. Test end points were survival, growth, and reproduction. The contaminated sediment was a composite of several cores taken to project depth (38 ft (11.6 m) below mean low water mark) from an area in Oakland Inner Harbor known to be contaminated with polycyclic aromatic hydrocarbons and metals. Comparisons were made with a clean control sediment. The control sediment is used in the laboratory cultures of N. arenaceodentata and was collected from Sequim, WA. Mean percent survival of Neanthes was high (>90 percent) in both the contaminated and control sediment across all food ration treatments. Individual wet weights were significantly reduced with decreasing food ration in both contaminated and control sediments. Significant differences in wet weight between sediment types were observed at the 1.OX, 0.5X, and 0.25X rations. Reproduction (fecundity and emergent juvenile (EJ) production) was also Chronic sublethal, Neanthes, Dredged material, San Francisco Bay, Food ration, Sediment.

  10. Reduction of erythema in hairless guinea pigs after cutaneous sulfur mustard vapor exposure by pretreatment with niacinamide, promethazine and indomethacin

    Energy Technology Data Exchange (ETDEWEB)

    Yourick, J.J.; Dawson, J.S.; Mitcheltree, L.W.

    1995-12-31

    Erythema is the initial symptom that occurs after sulfur mustard (HD) cutaneous exposure. The time course of HD-induced erythema is similar to that observed after UV irradiation, which can be reduced by indomethacin. Sulfur mustard lethality is decreased by using promethazine, which is an antihistamine. Niacinamide can reduce microvesication after HD vapor exposure in hairless guinea pig (HGP) skin. The present study examines the effect of the combined administration of niacinamide, indomethacin and promethazine used alone or in all possible combinations on the degree of erythema and histopathologic skin damage after HD exposure in HGP. Niacinamide (750 mg kg%`, i.p.), promethazine (12.5 mg kg%1, i.m.) or indomethacin (4 mg kg%1, p.o.) used singly or in combination was given as a 30-min pretreatment before an 8-min HD vapor cup skin exposure. Using a combination pretreatment of niacinamide, promethazine and indomethacin, erythema was reduced at 4 (91%) and 6 (55%) h, but not 24 h after HD. The incidence of histopathological skin changes (microvesicles, follicular involvement, epidermal necrosis, intracellular edema and pustular epidermatitis) 24 h after HD was not reduced. This study indicates that HD (induced erythema) may result from several different mechanisms, including inflammation, histamine release and DNA damage. It is suggested that two phases of inflammation may occur: an early phase sensitive to antihistamines and non-steroidal antiinflammatory drugs and a late phase of extensive cell damage that was not sensitive to these drug pretreatments.

  11. Comparison of different dentin pretreatment protocols on the bond strength of glass fiber post using self-etching adhesive.

    Science.gov (United States)

    Martinho, Frederico C; Carvalho, Claudio Antonio Talge; Oliveira, Luciane D; de Lacerda, Ana Júlia Farias; Xavier, Ana Cláudia Carvalho; Augusto, Marina Gullo; Zanatta, Rayssa Ferreira; Pucci, Cesar Rogerio

    2015-01-01

    This study compared the influence of different irrigants with and without ultrasound or laser irradiation on the bond strength of glass fiber posts using a self-etching adhesive in a supplementary dentin pretreatment. Ninety bovine incisor roots were divided into 3 groups according to the irrigant tested: 2% chlorhexidine (CHX) (n = 30); 2.5% sodium hypochlorite (NaOCl) (n = 30), and saline solution (control) (n = 30). Each group was randomly divided into 3 subgroups according to the supplementary dentin pretreatment: ultrasound, Nd:YAG laser, and nonsupplemented (control). A self-etching adhesive system (Futurabond DC; VOCO GmbH, Cuxhaven, Germany) was used, and the glass fiber posts were cemented with dual-cure epoxy-based luting agent (Bifix QM, VOCO GmbH). All roots were sectioned transversely, and the push-out test was performed. Failure mode analysis was also evaluated. Bond strength decreased significantly after the use of 2.5% NaOCl in all root thirds (P .05). The supplementary dentin pretreatment using the Nd:YAG laser or ultrasound did not improve the bond strength values for both NaOCl and CHX (P > .05). Moreover, the apical third exhibited the lowest mean bond strength values (P fiber posts using a self-etching adhesive system, whereas CHX preserved it. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. Sublethal and Transgenerational Effects of Abamectin on the Biological Performance of the Predatory Thrips Scolothrips longicornis (Thysanoptera: Thripidae).

    Science.gov (United States)

    Pakyari, Hajar; Enkegaard, Annie

    2015-04-01

    Determination of sublethal and transgenerational effects of pesticides on natural enemies is necessary for successful implementation of biocontrol in integrated pest management programs. In this study, these effects of abamectin on the predatory thrips Scolothrips longicornis Priesner fed on Tetranychus urticae Koch were estimated under laboratory conditions in which adult predators were exposed to pesticide residues on bean leaves. The estimated values of LC50 for female and male predators were 0.091 and 0.067 µg a.i./ml, respectively. Low-lethal concentrations (LC10, LC20 and LC30) of abamectin severely affected fecundity and longevity of treated females of S. longicornis. In addition, transgenerational effects on reproductive and life table parameters of the subsequent generation were observed. The results from this research can be used to develop guidelines for the use of abamectin to minimize the impact on S. longicornis. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Single-cell analysis of S. cerevisiae growth recovery after a sublethal heat-stress applied during an alcoholic fermentation.

    Science.gov (United States)

    Tibayrenc, Pierre; Preziosi-Belloy, Laurence; Ghommidh, Charles

    2011-06-01

    Interest in bioethanol production has experienced a resurgence in the last few years. Poor temperature control in industrial fermentation tanks exposes the yeast cells used for this production to intermittent heat stress which impairs fermentation efficiency. Therefore, there is a need for yeast strains with improved tolerance, able to recover from such temperature variations. Accordingly, this paper reports the development of methods for the characterization of Saccharomyces cerevisiae growth recovery after a sublethal heat stress. Single-cell measurements were carried out in order to detect cell-to-cell variability. Alcoholic batch fermentations were performed on a defined medium in a 2 l instrumented bioreactor. A rapid temperature shift from 33 to 43 °C was applied when ethanol concentration reached 50 g l⁻¹. Samples were collected at different times after the temperature shift. Single cell growth capability, lag-time and initial growth rate were determined by monitoring the growth of a statistically significant number of cells after agar medium plating. The rapid temperature shift resulted in an immediate arrest of growth and triggered a progressive loss of cultivability from 100 to 0.0001% within 8 h. Heat-injured cells were able to recover their growth capability on agar medium after a lag phase. Lag-time was longer and more widely distributed as the time of heat exposure increased. Thus, lag-time distribution gives an insight into strain sensitivity to heat-stress, and could be helpful for the selection of yeast strains of technological interest.

  14. Sublethal effects of subzero temperatures on the light brown apple moth, Epiphyas postvittana: fitness costs in response to partial freezing.

    Science.gov (United States)

    Morey, Amy C; Venette, Robert C; Hutchison, William D

    2017-11-28

    Population responses to environmental extremes often dictate the bounds to species' distributions. However, population dynamics at, or near, those range limits may also be affected by sublethal effects. We exposed late instars and pupae of an invasive leafroller, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), to cold temperatures and measured the effects of exposure on subsequent survivorship, development, and reproduction. Cold temperature was applied as acute exposure to -10 °C (a low, but not immediately lethal temperature for this species) or the onset of freezing (the peak of the supercooling point exotherm). Survival was defined as the ability to successfully eclose as an adult. We measured immature development times, pupal mass, and adult longevity as proxies of fitness in survivors. Additionally, surviving insects were mated with individuals that had not been exposed to cold to measure fertility. There was no difference between the proportion of larvae or pupae that survived acute exposure to -10 °C and those exposed to the control temperature. Approximately 17% of larvae and 8% of pupae survived brief periods with internal ice formation and continued development to become reproductively viable adults. Importantly, surviving the onset of freezing came with significant fitness costs but not to exposure to -10 °C; most insects that survived partial freezing had lower fertility and shorter adult lifespans than either the -10 °C or control group. These results are discussed within the context of forecasting invasive insect distributions. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  15. Lethal and sub-lethal effects of the fungicide chlorothalonil on three life stages of the grass shrimp, Palaemonetes pugio.

    Science.gov (United States)

    Key, Peter B; Meyer, Shelli L; Chung, Katy W

    2003-09-01

    Chlorothalonil (2,4,5,6-tetrachloroisophthalonitrile) is the second most widely used fungicide in the United States. Due to the widespread use of chlorothalonil, it is important to investigate the effects chlorothalonil may have on estuarine species such as the grass shrimp, Palaemonetes pugio. This study examined the toxicity of chlorothalonil to three life-history stages (embryo, larvae, adult) of the grass shrimp. Also, molting frequency, growth response and metamorphosis from a larval life cycle pulsed exposure assay were examined as sub-lethal indicators of chlorothalonil exposure. Results showed embryos were the least sensitive with a 96-h Median Lethal Concentration (LC50) of 396.0 microg/L (95% Confidence Interval [CI] 331.3-472.4 microg/L). The adult 96-h LC50 was 152.9 microg/L (95% CI 120.3-194.5 microg/L). Larvae were the most sensitive to chlorothalonil exposure with a 96-h LC50 of 49.5 microg/L (95% CI 44.4-55.27 microg/L). In the life cycle pulsed exposure assay, all surviving larvae in the treatments required significantly more molts to reach postlarvae than the control. Other measured parameters showed differences between treatments and control but there was no statistical significance. This research demonstrated that chlorothalonil is highly toxic to grass shrimp and that larval grass shrimp would be the most appropriate life stage to use for chlorothalonil risk assessments since that stage is the most sensitive.

  16. Sublethal injury and virulence changes in Listeria monocytogenes and Listeria innocua treated with antimicrobials carvacrol and citral.

    Science.gov (United States)

    Silva, A; Genovés, S; Martorell, P; Zanini, S F; Rodrigo, D; Martinez, A

    2015-09-01

    The aim of this study was to evaluate the effect of two antimicrobial substances, carvacrol and citral, on Listeria monocytogenes and Listeria innocua cells, as well as possible virulence changes in injured cells, using Caenorhabditis elegans as a model test. The results indicated that the percentage of sublethal damage was higher in L. monocytogenes than in L. innocua. The results of the study carried out by using C. elegans indicated that C. elegans fed in a lawn of L. monocytogenes previously treated with carvacrol showed a loss in life span (p ≤ 0.05) as compared with L. monocytogenes treated with citral, Escherichia coli OP50 as a negative control, and treated and untreated L. innocua. Egg laying was also affected: worms fed in a lawn of treated and untreated L. monocytogenes laid fewer eggs than those fed in a lawn of treated and untreated L. innocua or fed with OP50 as a negative control. Worms fed in a lawn of treated and untreated L. innocua also laid fewer eggs than those fed with OP50 as a negative control. A phenotype named bag of worms and an undescribed new one, "vulva inflammation", were also observed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Inactivation and sublethal injury of Escherichia coli and Listeria innocua by high hydrostatic pressure in model suspensions and beetroot juice

    Science.gov (United States)

    Sokołowska, Barbara; Skąpska, Sylwia; Niezgoda, Jolanta; Rutkowska, Małgorzata; Dekowska, Agnieszka; Rzoska, Sylwester J.

    2014-01-01

    Cells exposed to different physical and chemical treatments, including high hydrostatic pressure (HHP), suffer from injuries that could be reversible in food materials when stored. Escherichia coli and Listeria innocua cells suspended in phosphate-buffered saline (PBS) (model suspensions), and acidified beetroot juice were subjected to a pressure of 400 MPa at a temperature of 20°C for up to 10 min. The difference between the viable and non-injured cells was used to estimate the number of injured survivors. The reduction in E. coli cell number was 3.4-4.1 log after 10 min pressurization in model suspensions and 6.2 log in beetroot juice. Sublethally injured cells in PBS accounted for up to 2.7 log after 10 min HHP treatment and 0.8 log in beetroot juice. The reduction in L. innocua cell number after 10 min pressure treatment reached from 3.8 to 4.8 log, depending on the initial concentration in model suspensions. Among the surviving L. innocua cells, even up to 100% were injured. L. innocua cells were completely inactivated after 1 min HHP treatment in beetroot juice.

  18. Sublethal effects of copper on some biological traits of the amphipod Gammarus aequicauda reared under laboratory conditions.

    Science.gov (United States)

    Prato, E; Parlapiano, I; Biandolino, F

    2013-10-01

    The common and widespread copper contamination in marine coastal environments make toxicity data necessary to assess the aquatic hazard and risk of this metal. In the present study, the sublethal effects of copper on survival, growth and reproduction of Gammarus aequicauda were investigated. Amphipods were exposed for 77d to 2 nominal copper concentrations (50, 100 μg L(-1)). Survival was the most sensitive measure of effect and was significantly reduced, especially during early life stage (juveniles). Growth of amphipods was also negatively affected by copper and the growth impairment in G. aequicauda increases with increasing metal concentration. The reproductive traits were impaired by each of the copper concentrations, even if there were not any significant differences between control and copper treatments. The size at maturity increased with increasing copper, so the smallest ovigerous females in the control and copper treatments were 0.83 mm and 1.35 mm head length, respectively. There was a positive correlation between the brood size and the body size of the female in all treatments, whilst the fecundity (n°juveniles/female) decreased in the order control, 50 and 100 μg Cu L(-1). Copper demonstrates chronic toxicity to G. aequicauda at realistic environmental concentrations. The results of this study entail that the understanding of chronic toxicity of a substance, especially on population level effects, is crucial to assess the long-term effect of the substance in the ecosystem. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Larval Red Drum (Sciaenops ocellatus) Sublethal Exposure to Weathered Deepwater Horizon Crude Oil: Developmental and Transcriptomic Consequences.

    Science.gov (United States)

    Xu, Elvis Genbo; Khursigara, Alex J; Magnuson, Jason; Hazard, E Starr; Hardiman, Gary; Esbaugh, Andrew J; Roberts, Aaron P; Schlenk, Daniel

    2017-09-05

    The Deepwater Horizon (DWH) incident resulted in extensive oiling of the pelagic zone and shoreline habitats of many commercially important fish species. Exposure to the water-accommodated fraction (WAF) of oil from the spill causes developmental toxicity through cardiac defects in pelagic fish species. However, few studies have evaluated the effects of the oil on near-shore estuarine fish species such as red drum (Sciaenops ocellatus). Following exposure to a certified weathered slick oil (4.74 μg/L ∑PAH50) from the DWH event, significant sublethal impacts were observed ranging from impaired nervous system development [average 17 and 22% reductions in brain and eye area at 48 h postfertilization (hpf), respectively] to abnormal cardiac morphology (100% incidence at 24, 48, and 72 hpf) in red drum larvae. Consistent with the phenotypic responses, significantly differentially expressed transcripts, enriched gene ontology, and altered functions and canonical pathways predicted adverse outcomes in nervous and cardiovascular systems, with more pronounced changes at later larval stages. Our study demonstrated that the WAF of weathered slick oil of DWH caused morphological abnormalities predicted by a suite of advanced bioinformatic tools in early developing red drum and also provided the basis for a better understanding of molecular mechanisms of crude oil toxicity in fish.

  20. Chronic exposure to sublethal hexavalent chromium affects organ histopathology and serum cortisol profile of a teleost, Channa punctatus (Bloch)

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, Ashish K. [Department of Zoology, University of Allahabad, Allahabad-211002 (India); Mohanty, Banalata, E-mail: drbana_mohanty@rediffmail.com [Department of Zoology, University of Allahabad, Allahabad-211002 (India)

    2009-09-01

    Effects of chronic exposures (one and two months) to sublethal doses of hexavalent chromium (2 and 4 mg/L potassium dichromate) on organ histopathology and serum cortisol profile were investigated and their overall impact on growth and behavior of a teleost fish, Channa punctatus was elucidated. Histopathological lesions were distinct in the vital organs gill, kidney and liver. The gill lamellae became lifted, fused, and showed oedema. Hyperplasia and hypertrophy of lamellar epithelial cells were distinct with desquamation. Hypertrophy of epithelial cells of renal tubules and reduction in tubular lumens were observed in the trunk kidney. The atrophy of the head kidney interrenal cells and decreased serum cortisol level indicated exhaustion of interrenal activity. Hepatocyte vacuolization and shrinkage, nuclear pyknosis and increase of sinusoidal spaces were observed in the liver. Abnormal behavioral patterns and reduced growth rate were also noticed in the exposed fish. The chronic hexavalent chromium exposure thus by affecting histopathology of gill, kidney (including interrenal tissue) and liver could impair the vital functions of respiration, excretion, metabolic regulation and maintenance of stress homeostasis which in the long-run may pose serious threat to fish health and affect their population.

  1. Glyphosate sub-lethal toxicity to non-target organisms occurring in Jatropha curcas plantations in Brazil.

    Science.gov (United States)

    de Saraiva, Althiéris Souza; Sarmento, Renato Almeida; Pedro-Neto, Marçal; Teodoro, Adenir Vieira; Erasmo, Eduardo Andrea Lemus; Belchior, Diana Cléssia Vieira; de Azevedo, Emiliano Brandão

    2016-10-01

    Weed management in physic nut plantations has generally been performed by spraying the herbicide glyphosate. However, the effects of glyphosate on non-target organisms present in the crop system are unknown. Here, we evaluated the toxicity of glyphosate (Roundup Transorb(®)) against the pest species Polyphagotarsonemus latus (Acari: Tarsonemidae) and Tetranychus bastosi (Acari: Tetranychidae) which can be exposed by drift. These mites are considered pests of the physic nut; however, they can also feed and reside on weeds associated with the crop, serving as food sources for predatory mites. When subjected to residue (by ingestion of sap of treated plants), and direct contact to glyphosate, P. latus reproduction was affected but T. bastosi was affected only by the residual effect. Although the herbicide caused a reduction in the number of eggs laid by the females of both pest mites, it is suggested that sublethal effects of glyphosate stimulates oviposition of P. latus and T. bastosi: both species displayed higher reproductive rates when exposed to 0.36 kg ha(-1) of the herbicide. We conclude that glyphosate negatively affects the arthropod herbivores studied and we discuss possible implications on their biological control in Jatropha curcas plantations.

  2. Radiosensitivity and capacity for radiation-induced sublethal damage repair of canine transitional cell carcinoma (TCC) cell lines.

    Science.gov (United States)

    Parfitt, S L; Milner, R J; Salute, M E; Hintenlang, D E; Farese, J P; Bacon, N J; Bova, F J; Rajon, D A; Lurie, D M

    2011-09-01

    Understanding the inherent radiosensitivity and repair capacity of canine transitional cell carcinoma (TCC) can aid in optimizing radiation protocols to treat this disease. The objective of this study was to evaluate the parameters surviving fraction at 2 Gy (SF(2) ), α/β ratio and capacity for sublethal damage repair (SLDR) in response to radiation. Dose-response and split-dose studies were performed using the clonogenic assay. The mean SF(2) for three established TCC cell lines was high at 0.61. All the three cell lines exhibited a low to moderate α/β ratio, with the mean being 3.27. Two cell lines exhibited statistically increased survival at 4 and 24 h in the dose-response assay. Overall, our results indicate that the cell lines are moderately radioresistant, have a high repair capacity and behave similarly to a late-responding normal tissue. These findings indicate that the radiation protocols utilizing higher doses with less fractionation may be more effective for treating TCC. © 2011 Blackwell Publishing Ltd.

  3. Sub-lethal effects of fenbutatin oxide on prey location by the predatory mite Iphiseiodes zuluagai (Acari: Phytoseiidae).

    Science.gov (United States)

    Teodoro, Adenir V; Pallini, Angelo; Oliveira, Claudinei

    2009-04-01

    We used a Y-tube olfactometer to assess the sub-lethal effects of the acaricide fenbutatin oxide on the olfactory response of the predatory mite Iphiseiodes zuluagai towards odours from: (1) air or undamaged coffee plants; (2) undamaged or red spider mite Oligonychus ilicis-infested coffee plants; (3) undamaged or false spider mite Brevipalpus phoenicis-infested coffee plants. Predatory mite adult females were exposed to residues of fenbutatin oxide or distilled water on leaf discs during a period of 72 h prior experiments. When exposed to distilled water (control treatments), predatory mites significantly preferred undamaged plants over air, O. ilicis-infested plants over undamaged plants, and they did not prefer B. phoenicis-infested plants over undamaged plants. However, predatory mites that had been exposed to residues of fenbutatin oxide were neither attracted towards undamaged plants nor to O. ilicis-infested plants. Thus, fenbutatin oxide affected negatively the olfactory response of I. zuluagai. We conclude that sub-lethal-effect studies should be considered in pesticide selectivity programs since the ability of predatory mites to locate their prey may be negatively affected by non-lethal concentrations of pesticides.

  4. Further tests of changes in fish escape behavior resulting from sublethal stresses associated with hydroelectric turbine passage

    Energy Technology Data Exchange (ETDEWEB)

    Ryon, Michael G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cada, Glenn F. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Smith, John G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2004-04-01

    Fish that pass through a hydroelectric turbine may not be killed directly, but may nonetheless experience sublethal stresses that will increase their susceptibility to predators (indirect mortality). There is a need to develop reliable tests for indirect mortality so that the full consequences of passage through turbines (and other routes around a hydroelectric dam) can be assessed. The most commonly used laboratory technique for assessing susceptibility to predation is the predator preference test. This report evaluates the field application of a new technique that may be valuable for assessing indirect mortality, based on changes in a behavioral response to a startling stimulus (akin to perceiving an approaching predator). The study compared the behaviors of 70 fish passed through the turbine and another 70 under control conditions (either transferred from the holding tank or injected into the Alden loop downstream of turbine). The resulting image files were analyzed for a variety of behavioral measures including: presence of a startle response, time to first reaction, duration of reaction, time to formation of the maximum C-shape, time to completion of the C-shape, completeness of the C-shape, direction of turn, and degree of turn. The data were evaluated for statistical significance and patterns of response were identified.

  5. The Protective Role of Thiourea on Leuciscus cephalus Exposed to Sublethal Doses of Pendigan 330EC (Pendimethalin) Herbicide.

    Science.gov (United States)

    Paunescu, Alina; Zgurschi, Gabriela; Soare, Liliana Cristina; Man, George Mihail; Brinzea, Gheorghita; Fierascu, Radu Claudiu; Fierascu, Irina; Ponepal, Maria Cristina

    2016-08-01

    The aim of the study was to investigate the protective role of thiourea on the physiological, hematological, biochemical and histopathological parameters of Leuciscus cephalus exposed to sublethal concentration of Pendigan 330 EC herbicide. The animals were divided in four experimental groups (control, animals subjected to 1 ‰ thiourea, animals subjected to 4 × 10(-4) mL/L herbicide and, respectively, animals subjected to 4 × 10(-4) mL/L herbicide and 1 ‰ thiourea). Exposure of European chub to herbicide administered in water for 2 weeks determined installation of pathological changes in the liver and gills tissues. Also, were observed a decrease in the number of white blood cells and oxygen consumption, breathing frequency, and an increase in the number of red blood cells and glycaemia values. Thiourea counteracts the toxic action, describing itself as normal liver parenchyma and normal gills in animals intoxicated with herbicide, without lesion, and a return to normal values of the studied markers.

  6. Dilute alkali pretreatment of softwood pine: A biorefinery approach.

    Science.gov (United States)

    Safari, Ali; Karimi, Keikhosro; Shafiei, Marzieh

    2017-06-01

    Dilute alkali pretreatment was performed on softwood pine to maximize ethanol and biogas production via a biorefinery approach. Alkali pretreatments were performed with 0-2% w/v NaOH at 100-180°C for 1-5h. The liquid fraction of the pretreated substrates was subjected to anaerobic digestion. The solid fraction of the pretreatment was used for separate enzymatic hydrolysis and fermentation. High ethanol yields of 76.9‒78.0% were achieved by pretreatment with 2% (w/v) NaOH at 180°C. The highest biogas yield of 244mL/g volatile solid (at 25°C, 1bar) was achieved by the pretreatment with 1% (w/v) NaOH at 180°C. The highest gasoline equivalent (sum of ethanol and methane) of 197L per ton of pinewood and the lowest ethanol manufacturing cost of 0.75€/L was obtained after pretreatment with 1% NaOH at 180°C for 5h. The manufacturing cost of ethanol from untreated wood was 4.12€/L. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Understanding the impact of ionic liquid pretreatment on eucalyptus

    Energy Technology Data Exchange (ETDEWEB)

    Centikol, Ozgul [Joint Bioenergy Institute; Dibble, Dean [Joint Bioenergy Institute; Cheng, Gang [Joint Bioenergy Institute; Kent, Michael S [ORNL; Knierim, Manfred [Joint Bioenergy Institute; Melnichenko, Yuri B [ORNL

    2010-01-01

    The development of cost-competitive biofuels necessitates the realization of advanced biomass pretreatment technologies. Ionic liquids provide a basis for one of the most promising pretreatment technologies and are known to allow effective processing of cellulose and some biomass species. Here, we demonstrate that the ionic liquid 1-ethyl-3-methyl imidazolium acetate, [C2mim][OAc], induces structural changes at the molecular level in the cell wall of Eucalyptus globulus. Deacetylation of xylan, acetylation of the lignin units, selective removal of guaiacyl units (increasing the syringyl:guaiacyl ratio) and decreased {beta}-ether content were the most prominent changes observed. Scanning electron microscopy images of the plant cell wall sections reveal extensive swelling during [C2mim][OAc] pretreatment. X-ray diffraction measurements indicate a change in cellulose crystal structure from cellulose I to cellulose II after [C2mim][OAc] pretreatment. Enzymatic saccharification of the pretreated material produced increased sugar yields and improved hydrolysis kinetics after [C2mim][OAc] pretreatment. These results provide new insight into the mechanism of ionic liquid pretreatment and reaffirm that this approach may be promising for the production of cellulosic biofuels from woody biomass.

  8. Effects of Pretreatment Methods on Electrodes and SOFC Performance

    Directory of Open Access Journals (Sweden)

    Guo-Bin Jung

    2014-06-01

    Full Text Available Commercially available tapes (anode, electrolyte and paste (cathode were choosen to prepare anode-supported cells for solid oxide fuel cell applications. For both anode-supported cells or electrolyte-supported cells, the anode needs pretreatment to reduce NiO/YSZ to Ni/YSZ to increase its conductivity as well as its catalytic characteristics. In this study, the effects of different pretreatments (open-circuit, closed-circuit on cathode and anodes as well as SOFC performance are investigated. To investigate the influence of closed-circuit pretreatment on the NiO/YSZ anode alone, a Pt cathode is utilized as reference for comparison with the LSM cathode. The characterization of the electrical resistance, AC impedance, and SOFC performance of the resulting electrodes and/or anode-supported cell were carried out. It’s found that the influence of open-circuit pretreatment on the LSM cathode is limited. However, the influence of closed-circuit pretreatment on both the LSM cathode and NiO/YSZ anode and the resulting SOFC performance is profound. The effect of closed-circuit pretreatment on the NiO/YSZ anode is attributed to its change of electronic/pore structure as well as catalytic characteristics. With closed-circuit pretreatment, the SOFC performance improved greatly from the change of LSM cathode (and Pt reference compared to the Ni/YSZ anode.

  9. Enhanced enzymatic conversion with freeze pretreatment of rice straw

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ken-Lin; Thitikorn-amorn, Jitladda; Ou, Bay-Ming; Chen, Shan-He; Huang, Po-Jung [Institute of Biological Chemistry and Genomics Research Center Academia Sinica, Nankang, Taipei 115 (China); Hsieh, Jung-Feng [Department of Food Science, Fu Jen Catholic University, Xin Zhuang, Taipei 242 (China); Ratanakhanokchai, Khanok [School of Bioresources and Technology, King Mongkut' s University of Technology Thonburi, Bangkok 10150 (Thailand); Chen, Shui-Tein [Institute of Biological Chemistry and Genomics Research Center Academia Sinica, Nankang, Taipei 115 (China); Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei 106 (China)

    2011-01-15

    Production of bioethanol by the conversion of lignocellulosic waste has attracted much interest in recent years, because of its low cost and great potential availability. The pretreatment process is important for increasing the enzymatic digestibility of lignocellulosic materials. Enzymatic conversion with freeze pretreatment of rice straw was evaluated in this study. The freeze pretreatment was found to significantly increase the enzyme digestibility of rice straw from 48% to 84%. According to the results, enzymatic hydrolysis of unpretreated rice straw with 150 U cellulase and 100 U xylanase for 48 h yielded 226.77 g kg{sup -1} and 93.84 g kg{sup -1} substrate-reducing sugars respectively. However, the reducing sugar yields from freeze pretreatment under the same conditions were 417.27 g kg{sup -1} and 138.77 g kg{sup -1} substrate, respectively. In addition, hydrolyzates analysis showed that the highest glucose yield obtained during the enzymatic hydrolysis step in the present study was 371.91 g kg{sup -1} of dry rice straw, following pretreatment. Therefore, the enhanced enzymatic conversion with freeze pretreatment of rice straw was observed in this study. This indicated that freeze pretreatment was highly effective for enzymatic hydrolysis and low environmental impact. (author)

  10. Breakdown of hierarchical architecture in cellulose during dilute acid pretreatments

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yan [Northeastern Univ., Boston, MA (United States); Inouye, Hideyo [Northeastern Univ., Boston, MA (United States); Yang, Lin [Brookhaven National Lab. (BNL), Upton, NY (United States); Himmel, Michael E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tucker, Melvin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Makowski, Lee [Northeastern Univ., Boston, MA (United States)

    2015-02-28

    Cellulose can work as a feedstock for sustainable bioenergy because of its global abundance. Pretreatment of biomass has significant influence on the chemical availability of cellulose locked in recalcitrant microfibrils. Optimizing pretreatment depends on an understanding of its impact on the microscale and nanoscale molecular architecture. X-ray scattering experiments have been performed on native and pre-treated maize stover and models of cellulose architecture have been derived from these data. Ultra small-angle, very small-angle and small-angle X-ray scattering (USAXS, VSAXS and SAXS) probe three different levels of architectural scale. USAXS and SAXS have been used to study cellulose at two distinct length scales, modeling the fibrils as ~30 Å diameter rods packed into ~0.14 μm diameter bundles. VSAXS is sensitive to structural features at length scales between these two extremes. Detailed analysis of diffraction patterns from untreated and pretreated maize using cylindrical Guinier plots and the derivatives of these plots reveals the presence of substructures within the ~0.14 μm diameter bundles that correspond to grouping of cellulose approximately 30 nm in diameter. These sub-structures are resilient to dilute acid pretreatments but are sensitive to pretreatment when iron sulfate is added. Our results provide evidence of the hierarchical arrangement of cellulose at three length scales and the evolution of these arrangements during pre-treatments.

  11. Targeted increase in cerebral blood flow by transcranial near-infrared laser irradiation.

    Science.gov (United States)

    Uozumi, Yoichi; Nawashiro, Hiroshi; Sato, Shunichi; Kawauchi, Satoko; Shima, Katsuji; Kikuchi, Makoto

    2010-08-01

    Brain function is highly dependent on cerebral blood flow (CBF). The precise mechanisms by which blood flow is controlled by NIR laser irradiation on the central nervous system (CNS) have not been elucidated. In this study, we examined the effect of 808 nm laser diode irradiation on CBF in mice. We examined the effect of NIR irradiation on CBF at three different power densities (0.8, 1.6 and 3.2 W/cm(2)) and directly measured nitric oxide (NO) in brain tissue during NIR laser irradiation using an amperometric NO-selective electrode. We also examined the contribution of NO and a neurotransmitter, glutamate, to the regulation of CBF by using a nitric oxide synthase (NOS) inhibitor, N(g)-nitro-L-arginine methyl ester hydrochloride (L-NAME), and an N-methyl-D-aspartate (NMDA) receptor blocker, MK-801, respectively. We examined the change in brain tissue temperature during NIR laser irradiation. We also investigated the protection effect of NIR laser irradiation on transient cerebral ischemia using transient bilateral common carotid artery occlusion (BCCAO) in mice. We showed that NIR laser irradiation (1.6 W/cm(2) for 15-45 minutes) increased local CBF by 30% compared to that in control mice. NIR laser irradiation also induced a significant increase in cerebral NO concentration. In mice that received L-NAME, NIR laser irradiation did not induce any increase in CBF. Mice administered MK-801 showed an immediate increase but did not show a delayed additional increase in local CBF. The increase in brain tissue temperature induced by laser irradiation was estimated to be as low as 0.8 degrees C at 1.6 W/cm(2), indicating that the heating effect is not a main mechanism of the CBF increase in this condition. Pretreatment with NIR laser irradiation improved residual CBF and reduced the numbers of apoptotic cells in the hippocampus. Our data suggest that NIR laser irradiation is a promising experimental and therapeutic tool in the field of cerebral circulation research. (c

  12. Investigation of Pleurotus ostreatus pretreatment on switchgrass for ethanol production

    Science.gov (United States)

    Slavens, Shelyn Gehle

    Fungal pretreatment using the white-rot fungus Pleurotus ostreatus on switchgrass for ethanol production was studied. In a small-scale storage study, small switchgrass bales were inoculated with fungal spawn and automatically watered to maintain moisture. Sampled at 25, 53, and 81 d, the switchgrass composition was determined and liquid hot water (LHW) pretreatment was conducted. Fungal pretreatment significantly decreased the xylan and lignin content; glucan was not significantly affected by fungal loading. The glucan, xylan, and lignin contents significantly decreased with increased fungal pretreatment time. The effects of the fungal pretreatment were not highly evident after the LHW pretreatment, showing only changes based on sampling time. Although other biological activity within the bales increased cellulose degradation, the fungal pretreatment successfully reduced the switchgrass lignin and hemicellulose contents. In a laboratory-scale nutrient supplementation study, copper, manganese, glucose, or water was added to switchgrass to induce production of ligninolytic enzymes by P. ostreatus. After 40 d, ligninolytic enzyme activities and biomass composition were determined and simultaneous saccharification and fermentation (SSF) was conducted to determine ethanol yield. Laccase activity was similar for all supplements and manganese peroxidase (MnP) activity was significantly less in copper-treated samples than in the other fungal-inoculated samples. The fungal pretreatment reduced glucan, xylan, and lignin content, while increasing extractable sugars content. The lowest lignin contents occurred in the water-fungal treated samples and produced the greatest ethanol yields. The greatest lignin contents occurred in the copper-fungal treated samples and produced the lowest ethanol yields. Manganese-fungal and glucose-fungal treated samples had similar, intermediate lignin contents and produced similar, intermediate ethanol yields. Ethanol yields from switchgrass

  13. Influence of ultrasound pretreatment on wood physiochemical structure.

    Science.gov (United States)

    He, Zhengbin; Wang, Zhenyu; Zhao, Zijian; Yi, Songlin; Mu, Jun; Wang, Xiaoxu

    2017-01-01

    As an initial step to increase the use of renewable biomass resources, this study was aimed at investigating the effects of ultrasound pretreatment on structural changes of wood. Samples were pretreated by ultrasound with the power of 300W and frequency of 28kHz in aqueous soda solution, aqueous acetic acid, or distilled water, then pretreated and control samples were characterized via X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The results shown that ultrasound pretreatment is indeed effective in modifying the physiochemical structure of eucalyptus wood; the pretreatment decreased the quantity of alkali metals (e.g., potassium, calcium and magnesium) in the resulting material. Compared to the control group, the residual char content of samples pretreated in aqueous soda solution increased by 10.08%-20.12% and the reaction temperature decreased from 361°C to 341°C, however, in samples pretreated by ultrasound in acetic solution or distilled water, the residual char content decreased by 12.40%-21.45% and there were no significant differences in reactivity apart from a slightly higher maximum reaction rate. Ultrasound pretreatment increased the samples' crystallinity up to 35.5% and successfully removed cellulose, hemicellulose, and lignin from the samples; the pretreatment also increased the exposure of the sample to the treatment solutions, broke down sample pits, and generated collapses and microchannels on sample pits, and removed attachments in the samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. The effect of 648 nm diode laser irradiation on second messengers in senescent human keratinocytes

    Science.gov (United States)

    Hawkins Evans, D.; Abrahamse, H.

    2009-02-01

    Background/purpose: Stress induced premature senescence (SIPS) is defined as the long-term effect of subcytotoxic stress on proliferative cell types. Cells in SIPS display differences at the level of protein expression which affect energy metabolism, defense systems, redox potential, cell morphology and transduction pathways. This study aimed to determine the effect of laser irradiation on second messengers in senescent cells and to establish if that effect can be directly linked to changes in cellular function such as cell viability or proliferation. Materials and Methods: Human keratinocyte cell cultures were modified to induce premature senescence using repeated sub-lethal stresses of 200 uM H2O2 or 5% OH every day for four days with two days recovery. SIPS was confirmed by senescence-associated β-galactosidase staining. Control conditions included normal, repeated stress of 500 uM H2O2 to induce apoptosis and 200 uM PBN as an anti-oxidant or free radical scavenger. Cells were irradiated with 1.5 J/cm2 on day 1 and 4 using a 648 nm diode laser (3.3 mW/cm2) and cellular responses were measured 1 h post irradiation. The affect on second messengers was assessed by measuring cAMP, cGMP, nitric oxide and intracellular calcium (Ca2+) while functional changes were assessed using cell morphology, ATP cell viability, LDH membrane integrity and WST-1 cell proliferation. Results: Results indicate an increase in NO and a decrease in cGMP and Ca2+ in 200 uM H2O2 irradiated cells while PBN irradiated cells showed a decrease in cAMP and an increase in ATP viability and cell proliferation. Conclusion: Laser irradiation influences cell signaling which ultimately changes the biological function of senescent cells. If laser therapy can stimulate the biological function of senescent cells it may be beneficial to conditions such as immune senescence, skin ageing, muscle atrophy, premature ageing of arteries in patients with advanced heart disease, neurodegenerative disorders and

  15. Evaluation of wet oxidation pretreatment for enzymatic hydrolysis of softwood

    DEFF Research Database (Denmark)

    Palonen, H.; Thomsen, A.B.; Tenkanen, M.

    2004-01-01

    The wet oxidation pretreatment (water, oxygen, elevated temperature, and pressure) of softwood (Picea abies) was investigated for enhancing enzymatic hydrolysis. The pretreatment was preliminarily optimized. Six different combinations of reaction time, temperature, and pH were applied......, and the compositions of solid and liquid fractions were analyzed. The solid fraction after wet oxidation contained 58-64% cellulose, 2-16% hemicellulose, and 24-30% lignin. The pretreatment series gave information about the roles of lignin and hemicellulose in the enzymatic hydrolysis. The temperature...

  16. PROJECT W-551 INTERIM PRETREATMENT SYSTEM PRECONCEPTUAL CANDIDATE TECHNOLOGY DESCRIPTIONS

    Energy Technology Data Exchange (ETDEWEB)

    MAY TH

    2008-08-12

    The Office of River Protection (ORP) has authorized a study to recommend and select options for interim pretreatment of tank waste and support Waste Treatment Plant (WTP) low activity waste (LAW) operations prior to startup of all the WTP facilities. The Interim Pretreatment System (IPS) is to be a moderately sized system which separates entrained solids and 137Cs from tank waste for an interim time period while WTP high level waste vitrification and pretreatment facilities are completed. This study's objective is to prepare pre-conceptual technology descriptions that expand the technical detail for selected solid and cesium separation technologies. This revision includes information on additional feed tanks.

  17. Combination of biological pretreatment with mild acid pretreatment for enzymatic hydrolysis and ethanol production from water hyacinth.

    Science.gov (United States)

    Ma, Fuying; Yang, Na; Xu, Chunyan; Yu, Hongbo; Wu, Jianguo; Zhang, Xiaoyu

    2010-12-01

    The mild acid pretreatment and the combination of biological pretreatment by a white rot fungus Echinodontium taxodii or a brown rot fungus Antrodia sp. 5898 with mild acid pretreatment were evaluated under different pretreatment conditions for enzymatic hydrolysis and ethanol production from water hyacinth. The combined pretreatment with E. taxodii (10 days) and 0.25% H(2)SO(4) was proved to be more effective than the sole acid pretreatment. The reducing sugar yield from enzymatic hydrolysis of co-treated water hyacinth increased 1.13-2.11 fold than that of acid-treated water hyacinth at the same conditions. The following study on separate hydrolysis and fermentation with Saccharomyces cerevisiae indicated that the ethanol yield from co-treated water hyacinth achieved 0.192 g/g of dry matter, which increased 1.34-fold than that from acid-treated water hyacinth (0.146 g/g of dry matter). This suggested that the combination of biological and mild acid pretreatment is a promising method to improve enzymatic hydrolysis and ethanol production from water hyacinth with low lignin content. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  18. Treatment of opium alkaloid containing wastewater in sequencing batch reactor (SBR)-Effect of gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bural, Cavit B.; Demirer, Goksel N. [Middle East Technical University, Department of Environmental Engineering, 06531 Ankara (Turkey); Kantoglu, Omer [Turkish Atomic Energy Authority, Saraykoy Nuclear Research and Training Center, 06982, Kazan, Ankara (Turkey); Dilek, Filiz B., E-mail: fdilek@metu.edu.t [Middle East Technical University, Department of Environmental Engineering, 06531 Ankara (Turkey)

    2010-04-15

    Aerobic biological treatment of opium alkaloid containing wastewater as well as the effect of gamma irradiation as pre-treatment was investigated. Biodegradability of raw wastewater was assessed in aerobic batch reactors and was found highly biodegradable (83-90% degradation). The effect of irradiation (40 and 140 kGy) on biodegradability was also evaluated in terms of BOD{sub 5}/COD values and results revealed that irradiation imparted no further enhancement in the biodegradability. Despite the highly biodegradable nature of wastewater, further experiments in sequencing batch reactors (SBR) revealed that the treatment operation was not possible due to sludge settleability problem observed beyond an influent COD value of 2000 mg dm{sup -3}. Possible reasons for this problem were investigated, and the high molecular weight, large size and aromatic structure of the organic pollutants present in wastewater was thought to contribute to poor settleability. Initial efforts to solve this problem by modifying the operational conditions, such as SRT reduction, failed. However, further operational modifications including addition of phosphate buffer cured the settleability problem and influent COD was increased up to 5000 mg dm{sup -3}. Significant COD removal efficiencies (>70%) were obtained in both SBRs fed with original and irradiated wastewaters (by 40 kGy). However, pre-irradiated wastewater provided complete thebain removal and a better settling sludge, which was thought due to degradation of complex structure by radiation application. Degradation of the structure was observed by GC/MS analyses and enhancement in filterability tests.

  19. Comparison of aqueous ammonia and dilute acid pretreatment of bamboo fractions: Structure properties and enzymatic hydrolysis.

    Science.gov (United States)

    Xin, Donglin; Yang, Zhong; Liu, Feng; Xu, Xueru; Zhang, Junhua

    2015-01-01

    The effect of two pretreatments methods, aqueous ammonia (SAA) and dilute acid (DA), on the chemical compositions, cellulose crystallinity, morphologic change, and enzymatic hydrolysis of bamboo fractions (bamboo yellow, timber, green, and knot) was compared. Bamboo fractions with SAA pretreatment had better hydrolysability than those with DA pretreatment. High crystallinity index resulted in low hydrolysis yield in the conversion of SAA pretreated bamboo fractions, not DA pretreated fractions. The increase of cellulase loading had modestly positive effect in the hydrolysis of both SAA and DA pretreated bamboo fractions, while supplement of xylanase significantly increased the hydrolysis of the pretreated bamboo fractions, especially after SAA pretreatment. The results indicated that SAA pretreatment was more effective than DA pretreatment in conversion of bamboo fractions, and supplementation of xylanase was necessary in effective conversion of the SAA pretreated fractions into fermentable sugars. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Pretreatment of microalgae to improve biogas production: a review.

    Science.gov (United States)

    Passos, Fabiana; Uggetti, Enrica; Carrère, Hélène; Ferrer, Ivet

    2014-11-01

    Microalgae have been intensively studied as a source of biomass for replacing conventional fossil fuels in the last decade. The optimization of biomass production, harvesting and downstream processing is necessary for enabling its full-scale application. Regarding biofuels, biogas production is limited by the characteristics of microalgae, in particular the complex cell wall structure of most algae species. Therefore, pretreatment methods have been investigated for microalgae cell wall disruption and biomass solubilization before undergoing anaerobic digestion. This paper summarises the state of the art of different pretreatment techniques used for improving microalgae anaerobic biodegradability. Pretreatments were divided into 4 categories: (i) thermal; (ii) mechanical; (iii) chemical and (iv) biological methods. According to experimental results, all of them are effective at increasing biomass solubilization and methane yield, pretreatment effect being species dependent. Pilot-scale research is still missing and would help evaluating the feasibility of full-scale implementation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Effects of Pretreatments in Convective Dehydration of Rosehip (Rosa eglanteria

    Directory of Open Access Journals (Sweden)

    Alejandra Mabellini

    2012-04-01

    Full Text Available The aim of this work was to experimentally determine drying curves for thin layer and bed drying of rosehip fruits, with and without pretreatments, to reduce processing times as a function of drying air operating variables, to propose dehydration kinetics of fruits and to determine its kinetic parameters for further use within drying simulation software. Fruits were pre-treated both chemically and mechanically, which included dipping the fruits in NaOH and ethyl oleate solutions; and cutting or perforating the fruit cuticle, respectively. Simulation models were then adopted to fit the kinetics drying data considering fruit volume shrinkage. These simple models minimized the calculation time during the simulation of deep-bed driers. Results show that pre-treatments reduced processing times up to 57%, and evaluated models satisfactorily predicted the drying of rosehip fruit. Effective mass diffusion coefficients were up to 4-fold greater when fruit was submitted to mechanical pretreatments.

  2. Optimization of microwave pretreatment on wheat straw for ethanol production

    DEFF Research Database (Denmark)

    Xu, Jian; Chen, Hongzhang; Kádár, Zsófia

    2011-01-01

    An orthogonal design (L9(34)) was used to optimize the microwave pretreatment on wheat straw for ethanol production. The orthogonal analysis was done based on the results obtained from the nine pretreatments. The effect of four factors including the ratio of biomass to NaOH solution, pretreatment...... time, microwave power, and the concentration of NaOH solution with three different levels on the chemical composition, cellulose/hemicellulose recoveries and ethanol concentration was investigated. According to the orthogonal analysis, pretreatment with the ratio of biomass to liquid at 80 g kg−1......, the NaOH concentration of 10 kg m−3, the microwave power of 1000 W for 15 min was confirmed to be the optimal condition. The ethanol yield was 148.93 g kg−1 wheat straw at this condition, much higher than that from the untreated material which was only 26.78 g kg−1....

  3. Ensiling as pretreatment of grass for lignocellulosic biomass conversion

    DEFF Research Database (Denmark)

    Ambye-Jensen, Morten

    Development of sound technologies of biomass conversion will be increasingly important for many years to come as planetary bounderies drive the development towards a biobased society. Pretreatment of lignocellulosic biomass is, in this regard, an essential technology. Current pretreatment methods......, based on severe physio-chemical processes, are effective, however, they are also costly and energy demanding. An alternative biological pretreatment method, based on the well-known biomass preservation of ensiling, has been proposed. Ensiling holds potential as an integrated storage and pretreatment...... was devoted to method development. This resulted in the development of a simple and flexible standard method forlaboratory ensilingwith a high reproducibility,which is well suited for high-throughput experiments.   A comprehensive study on important parameters in ensiling was conducted to find optimal...

  4. Pretreatments to enhance the digestibility of lignocellulosic biomass

    NARCIS (Netherlands)

    Hendriks, A.T.W.M.; Zeeman, G.

    2009-01-01

    Lignocellulosic biomass represents a rather unused source for biogas and ethanol production. Many factors, like lignin content, crystallinity of cellulose, and particle size, limit the digestibility of the hemicellulose and cellulose present in the lignocellulosic biomass. Pretreatments have as a

  5. 40 CFR 417.64 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Soap Flakes and Powders Subcategory § 417.64 Pretreatment standards for existing sources. Any existing...

  6. 40 CFR 417.24 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Fatty Acid Manufacturing by Fat Splitting Subcategory § 417.24 Pretreatment standards for existing sources. Any existing...

  7. 40 CFR 417.74 - Pretreatment standards for existing sources.

    Science.gov (United States)

    2010-07-01

    ...) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Bar Soaps Subcategory § 417.74 Pretreatment standards for existing sources. Any existing source subject to...

  8. Pretreatment of bituminous coal for hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Hupfer, H.

    1943-03-29

    Bituminous coal became plastic at certain temperature ranges and swelled, causing plugging of preheater tubes. With few exceptions, this problem was encountered only when hydrogenating bituminous coal. This swelling often appeared in the coking of coals, and for the majority of the cases it was found that efforts to reduce the baking ability of bituminous coal also reduced the swelling of coal paste in the preheater tubes. Three methods of pretreatment to reduce swelling were preheating, oxidation (anoxidation), and sulfur treatment. The preheating by hot nitrogen at 250 atm for 3 hours showed no improvement in swelling characteristics, but produced a greater asphalt content and a lower amount of gasification. Absorption of oxygen was shown to increase the viscosity of the coal paste, while preheating in a vacuum showed no effects. Oxidation (anoxidation) increased the splitting and gasification and gave higher asphalt content. The baking ability of Saar coal could be destroyed by addition of 2.5% sulfur and heating for 1/sup 1///sub 2/ hours at 110/sup 0/C, in a stream of H/sub 2/S. The volatile content dropped significantly when the same coal was heated to 200/sup 0/ to 250/sup 0/C. When neutralized Saar coal was dried under a stream of H/sub 2/S, only slight deterioration of the yield was noted with equal degree of gasification. It was concluded that a more or less distinct improvement would be observed from the absorption of sulfur, but that residue processing would have to be altered to account for the sulfur content.

  9. Pretreatment seizure semiology in childhood absence epilepsy.

    Science.gov (United States)

    Kessler, Sudha Kilaru; Shinnar, Shlomo; Cnaan, Avital; Dlugos, Dennis; Conry, Joan; Hirtz, Deborah G; Hu, Fengming; Liu, Chunyan; Mizrahi, Eli M; Moshé, Solomon L; Clark, Peggy; Glauser, Tracy A

    2017-08-15

    To determine seizure semiology in children with newly diagnosed childhood absence epilepsy and to evaluate associations with short-term treatment outcomes. For participants enrolled in a multicenter, randomized, double-blind, comparative-effectiveness trial, semiologic features of pretreatment seizures were analyzed as predictors of treatment outcome at the week 16 to 20 visit. Video of 1,932 electrographic absence seizures from 416 participants was evaluated. Median seizure duration was 10.2 seconds; median time between electrographic seizure onset and clinical manifestation onset was 1.5 seconds. For individual seizures and by participant, the most common semiology features were pause/stare (seizure 95.5%, participant 99.3%), motor automatisms (60.6%, 86.1%), and eye involvement (54.9%, 76.5%). The interrater agreement for motor automatisms and eye involvement was good (72%-84%). Variability of semiology features between seizures even within participants was high. Clustering analyses revealed 4 patterns (involving the presence/absence of eye involvement and motor automatisms superimposed on the nearly ubiquitous pause/stare). Most participants experienced more than one seizure cluster pattern. No individual semiologic feature was individually predictive of short-term outcome. Seizure freedom was half as likely in participants with one or more seizure having the pattern of eye involvement without motor automatisms than in participants without this pattern. Almost all absence seizures are characterized by a pause in activity or staring, but rarely is this the only feature. Semiologic features tend to cluster, resulting in identifiable absence seizure subtypes with significant intraparticipant seizure phenomenologic heterogeneity. One seizure subtype, pause/stare and eye involvement but no motor automatisms, is specifically associated with a worse treatment outcome. © 2017 American Academy of Neurology.

  10. Food irradiation: Gamma processing facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kunstadt, P. [MDS Nordion International, 447 March Road. Kanata, Ontario, K2K148 (Canada)

    1997-12-31

    The number of products being radiation processed is constantly increasing and today include such diverse items as medical disposable, fruits and vegetables, bulk spices, meats, sea foods and waste effluents. Not only do the products differ but also many products, even those within the same groupings, require different minimum and maximum radiation doses. These variations create many different requirements in the irradiator design. The design of Cobalt-60 radiation processing facilities is well established for a number of commercial applications. Installations in over 40 countries, with some in operation since the early 1960s, are testimony to the fact that irradiator design, manufacture, installation and operation is a well established technology. However, in order to design gamma irradiators for the preservation of foods one must recognize those parameters typical to the food irradiation process as well as those systems and methods already well established in the food industry. This paper discusses the basic design concepts for gamma food irradiators. They are most efficient when designed to handle a limited product density range at an established dose. Safety of Cobalt-60 transport, safe facility operation principles and the effect of various processing parameters on economics, will also be discussed. (Author)

  11. Proton irradiation for hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Matsuzaki, Yasushi; Chiba, Shunya [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine; Tanaka, Naomi

    1999-02-01

    A curative effect of high dose proton irradiation for hepatoma was investigated. In cases of single nodular type HCC, radiation field was limited to tumor, and in cases of multi nodular type HCC, irradiation was also fractionated. An average dose of radiation was 4 Gy/time, average times were 16, and an average total dose was 72 Gy. Tumor size reduction rate at 6 months after proton irradiation (123 cases) was CR (17.9%), PR (52.0%), NC (29.3%) and PD (0.8%). And the reduction rate of tumor size in monotherapy cases was 100% (after 3 weeks), 96% (after 1 year) and 88% (after 2 years). The local control rate was 99.1% (after 1 year) and 91.4% (after 3-5 years). AFP value significantly decreased from 571.0{+-}1266.6 ng/ml before radiation to 145.4{+-}346.3 ng/ml after radiation (p<0.0005). The recurrence after radiation occurred more at outside of radiation field, significantly. Indication basis of proton irradiation was showed in this article. Because selective radiation is possible, the proton irradiation should be optimum therapy in specific carcinomas of deep organ. (K.H.)

  12. Elective ilioingunial lymph node irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Henderson, R.H.; Parsons, J.T.; Morgan, L.; Million, R.R.

    1984-06-01

    Most radiologists accept that modest doses of irradiation (4500-5000 rad/4 1/2-5 weeks) can control subclinical regional lymph node metastases from squamous cell carcinomas of the head and neck and adenocarcinomas of the breast. There have been few reports concerning elective irradiation of the ilioinguinal region. Between October 1964 and March 1980, 91 patients whose primary cancers placed the ilioinguinal lymph nodes at risk received elective irradiation at the University of Florida. Included are patients with cancers of the vulva, penis, urethra, anus and lower anal canal, and cervix or vaginal cancers that involved the distal one-third of the vagina. In 81 patients, both inguinal areas were clinically negative; in 10 patients, one inguinal area was positive and the other negative by clinical examination. The single significant complication was a bilateral femoral neck fracture. The inguinal areas of four patients developed mild to moderate fibrosis. One patient with moderate fibrosis had bilateral mild leg edema that was questionably related to irradiation. Complications were dose-related. The advantages and dis-advantages of elective ilioinguinal node irradiation versus elective inguinal lymph node dissection or no elective treatment are discussed.

  13. Currently developing opportunities in food irradiation and modern irradiation facilities

    Energy Technology Data Exchange (ETDEWEB)

    Wanke, R. [Director Business Development. SteriGenics International Inc. 17901 East Warren Avenue No. 4, Detroit, Michigan 48224-1333 (United States)

    1997-12-31

    I. Factor currently influencing advancing opportunities for food irradiation include: heightened incidence and awareness of food borne illnesses and