Characterization of terpenoid volatiles from cultivars of eastern hemlock (Tsuga canadensis).

Science.gov (United States)

Lagalante, Anthony F; Montgomery, Michael E; Calvosa, Frank C; Mirzabeigi, Michael N

2007-12-26

The volatile terpenoid fraction from needles in 13 cultivars of Tsuga canadensis L. (Carriere) was analyzed by gas chromatography with mass spectrometry (GC-MS). The results of this study are considered along with previously reported results for foliar terpenoid levels of the Asian (T. sieboldii, T. chinensis, T. diversifolia), western North American (T. mertensiana, T. heterophylla), and eastern North American species (T. canadensis, T. caroliniana) of hemlock to draw conclusions about the potential of cultivar host resistance to the hemlock woolly adelgid (Adelges tsugae Annand). It is suggested that hemlocks in eastern North America have adapted their terpenoid chemistry for protection against endemic defoliators and that this has made them vulnerable to non-native, sucking pests such as adelgids and scales. Some cultivars of T. canadensis have a terpenoid profile that resembles that of the resistant noneastern North American species and are candidates for biological screening for resistance. Among the cultivars, the variation in terpenoid chemistry did not absolutely correspond with the considerable differences in morphological characters observed, indicating that the terpenoid chemistry is not definitively coupled with hemlock morphology.

Tsuga canadensis (L.) Carr, mortality will impact hydrologic processes in southern Appalachian forest ecosystems

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Chelcy R. Ford; James M. Vose

2007-01-01

Eastern hemlock (Tsuga canadensis (L.) Carr.) is one of the principal riparian and cove canopy species in the southern Appalachian Mountains. Throughout its range, eastern hemlock is facing potential widespread mortality from the hemlock woolly adelgid (HWA). If HWA-induced eastern hemlock mortality alters hydrologic function, land managers...

The range and response of Neonicotinoids on hemlock woolly adelgid, Adelges tsugae (Hemiptera: Adelgidae)

Science.gov (United States)

Shimat V. Joseph; S. Kristine Braman; Jim Quick; James L. Hanula

2011-01-01

Hemlock woolly adelgid (HWA), Adelges tsugae Annand is a serious pest of eastern and Carolina hemlock in the eastern United States. A series of experiments compared commercially available and experimental insecticides, rates, application methods and timing for HWA control in Georgia and North Carolina. Safari 20 SG (dinotefuran) provided an average of 79 to 87%...

Projected Future Distribution of Tsuga canadensis across Alternative Climate Scenarios in Maine, U.S

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Kathleen Dunckel

2017-08-01

Full Text Available Climate change is having an impact on forest ecosystems around the world and is expected to alter the suitable habitat of individual tree species. Forest managers require resources about potential impacts of climate change at the regional scale to aid in climate mitigation efforts. By understanding the geographic distribution of changes in suitable habitat, migration corridors can be identified for conservation and active management. With the increased availability of climate projection data, ancillary Geographic Information Systems data, and field observations, modeling efforts at the regional scale are now possible. Here, we modeled and mapped the continuous distribution of Tsuga canadensis throughout the state of Maine at the regional scale(30 m with high precision (89% of pixels had a coefficient of variation ≤ 4.0%. The random forest algorithm was used to create a strong prediction of suitable habitat for the years 2050 and 2100 from both high and low emission climate projections. The results clearly suggest a significant gain in suitable habitat for Tsuga canadensis range with a general northwest expansion.

Triterpenoids and Polysaccharide Fractions of Ganoderma tsugae Exert Different Effects on Antiallergic Activities

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Miaw-Ling Chen

2015-01-01

Full Text Available This study was to investigate antiallergic effects of triterpenoids (Gt-TRE and polysaccharide (Gt-PS extracts from Ganoderma tsugae, using mast cell line RBL-2H3, T cell line EL4, primary T cells, and transfected RAW264.7 macrophage cells. The results showed that histamine secreted from activated RBL-2H3 mast cells was significantly suppressed by Gt-TRE but not Gt-PS. Interleukin- (IL- 4 secreted from activated EL4 cells was significantly suppressed by Gt-TRE but not Gt-PS. Further primary CD4+ T cells cultures also confirmed that Gt-TRE (5~50 µg/mL significantly suppressed Th2 cytokines IL-4 and IL-5 secretions but had no effect on Th1 cytokines IL-2 and interferon (IFN-γ. Gt-PS did not affect IL-4 and IL-5 secretions until higher doses (400, 500 µg/mL and significantly suppressed IFNγ secretions but enhanced IL-2 at these high doses. The reporter gene assay indicated that Gt-TRE inhibited but Gt-PS enhanced the transcriptional activity of NF-κB in activated transfected RAW264.7 cells and transfected EL4 cells. IL-4 secreted by this transfected EL-4 cells was also significantly decreased by Gt-TRE but not by Gt-PS, suggesting that these two fractions may exert different effects on NF-κB related cytokines expression. These data suggested that triterpenoids fraction of Ganoderma tsugae might be the main constituents to alleviate allergic asthma.

Feeding by Leucopis argenticollis and Leucopis piniperda (Diptera: Chamaemyiidae) from the western USA on Adelges tsugae (Hemiptera: Adelgidae) in the eastern USA

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K. Motley; N.P. Havill; A.L. Arsenault-Benoit; A.E. Mayfield; D.S. Ott; D. Ross; M.C. Whitmore; K.F. Wallin

2017-01-01

Leucopis argenticollis (Zetterstedt) and Leucopis piniperda (Malloch) are known to feed on the lineage of Adelges tsugae Annand that is native to western North America, but it is not known if they will survive on the lineage that was introduced from Japan to the eastern USA. In 2014, western ...

Chemical characteristics and anti-proliferation activities of Ganoderma tsugae polysaccharides.

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Chien, Rao-Chi; Yen, Ming-Tsung; Tseng, Yu-Hsiu; Mau, Jeng-Leun

2015-09-05

Polysaccharides were extracted by hot-water and hot-alkali from four forms of Ganoderma tsugae including mature and baby Ling chih, mycelium and filtrate. Different profiles of proximate composition and monosaccharide constituents, and element contents were found in the extracted polysaccharides from different extractions and different forms. The molecular weight distributions of polysaccharides were 2.8×10(4)-6.5×10(5)Da and their infrared spectra were comparable. The hot-alkali extracted polysaccharides exhibited better anti-proliferation on IMR32 cells than the hot-water extracted polysaccharides, which were in turn more effective than the hot-water extracts. Besides, most hot-water extracts and both extracted polysaccharides exhibited an anti-proliferation effect on Hep G2 cells. However, the hot-water extracts showed less effective in anti-proliferation of IMR32 and Hep G2 cells. Based on the anti-tumor effects, both polysaccharides could be prepared for use in the formulation of nutraceuticals and functional foods. Copyright © 2015 Elsevier Ltd. All rights reserved.

Macro-scale assessment of demographic and environmental variation within genetically derived evolutionary lineages of eastern hemlock (Tsuga canadensis), an imperiled conifer of the eastern United States

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Anantha M. Prasad; Kevin M. Potter

2017-01-01

Eastern hemlock (Tsuga canadensis) occupies a large swath of eastern North America and has historically undergone range expansion and contraction resulting in several genetically separate lineages. This conifer is currently experiencing mortality across most of its range following infestation of a non-native insect. With the goal of better...

Influence of eastern hemlock (Tsuga canadensis L.) on fish community structure and function in headwater streams of the Delaware River basin

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Ross, R.M.; Bennett, R.M.; Snyder, C.D.; Young, J.A.; Smith, D.R.; Lemarie, D.P.

2003-01-01

Hemlock (Tsuga canadensis) forest of the eastern U.S. are in decline due to invasion by the exotic insect hemlock woolly adelgid (Adelges tsugae). Aquatic biodiversity in hemlock ecosystems has not been documented; thus the true impact of the infestation cannot be assessed. We compared ichthyofaunal assemblages and trophic structure of streams draining hemlock and hardwood forests by sampling first- and second-order streams draining 14 paired hemlock and hardwood stands during base flows in July 1997 at the Delaware Water Gap National Recreation Area of Pennsylvania and New Jersey. Over 1400 fish of 15 species and 7 families were collected, but hemlock and hardwood streams individually harbored only one to four species. Brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) were two to three times as prevalent in hemlock than hardwood streams. Insectivorous fishes occurred in significantly higher proportion in streams of hardwood (0.90) than hemlock (0.46) stands, while piscivores occurred more often in hemlock (0.85) than hardwood (0.54) stands. Functional (trophic) diversity of fishes in hemlock and second-order streams was numerically greater than that of hardwood and first-order streams. Species composition also differed by stream order and terrain type. Biodiversity is threatened at several levels within hemlock ecosystems at risk to the hemlock woolly adelgid in eastern U.S. forests.

Ganoderma tsugae Hepatoprotection against Exhaustive Exercise-Induced Liver Injury in Rats

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Wan-Teng Lin

2013-01-01

Full Text Available Several studies have been shown that accelerated apoptosis is involved in post-exercise lymphocytopenia and tissue damage after high-intensity exercise. Ganoderma tsugae (GT is one of the well-known medicinal mushrooms that possess various pharmacological functions. This mushroom has traditionally been used for health promotion purposes. This study investigates the hepatoprotective effects of GT on exhaustive exercise-induced liver damage. Twenty-four male Sprague-Dawley rats were randomly divided into four groups and designated as exhaustive exercise only (E, exhaustive exercise with low dosage (EL, medium dosage (EM and high dosage (EH GT at 0, 0.1875, 0.9375 and 1.875 g/kg/day, respectively. After 30 days all rats were euthanized immediately after an exhaustive running challenge on a motorized treadmill. The rat livers were immediately harvested. Evidence of apoptotic liver cell death was revealed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL assay and caspases mediated cascade events. DNA fragmentation, an apoptosis process, can be examined using TUNEL assay. A few TUNEL-positive hepatocytes, compared to the exercise only group, were observed in the livers from exhaustive animals supplemented with GT. Immunoblot analysis also showed that caspase-6-mediated specific cleavage of lamin A/C was increased significantly in the livers of group E, but was significantly decreased in the EM and EH groups. Our observations demonstrate that GT possesses anti-apoptotic and hepatoprotective potential after exhaustive exercise.

Ganoderma tsugae hepatoprotection against exhaustive exercise-induced liver injury in rats.

Science.gov (United States)

Huang, Chi-Chang; Huang, Wen-Ching; Yang, Suh-Ching; Chan, Chih-Chi; Lin, Wan-Teng

2013-01-29

Several studies have been shown that accelerated apoptosis is involved in post-exercise lymphocytopenia and tissue damage after high-intensity exercise. Ganoderma tsugae (GT) is one of the well-known medicinal mushrooms that possess various pharmacological functions. This mushroom has traditionally been used for health promotion purposes. This study investigates the hepatoprotective effects of GT on exhaustive exercise-induced liver damage. Twenty-four male Sprague-Dawley rats were randomly divided into four groups and designated as exhaustive exercise only (E), exhaustive exercise with low dosage (EL), medium dosage (EM) and high dosage (EH) GT at 0, 0.1875, 0.9375 and 1.875 g/kg/day, respectively. After 30 days all rats were euthanized immediately after an exhaustive running challenge on a motorized treadmill. The rat livers were immediately harvested. Evidence of apoptotic liver cell death was revealed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and caspases mediated cascade events. DNA fragmentation, an apoptosis process, can be examined using TUNEL assay. A few TUNEL-positive hepatocytes, compared to the exercise only group, were observed in the livers from exhaustive animals supplemented with GT. Immunoblot analysis also showed that caspase-6-mediated specific cleavage of lamin A/C was increased significantly in the livers of group E, but was significantly decreased in the EM and EH groups. Our observations demonstrate that GT possesses anti-apoptotic and hepatoprotective potential after exhaustive exercise.

Assessment of Imidacloprid and Its Metabolites in Foliage of Eastern Hemlock Multiple Years Following Treatment for Hemlock Woolly Adelgid, Adelges tsugae (Hemiptera: Adelgidae), in Forested Conditions.

Science.gov (United States)

Benton, E P; Grant, J F; Webster, R J; Nichols, R J; Cowles, R S; Lagalante, A F; Coots, C I

2015-12-01

Widespread decline and mortality of eastern hemlock, Tsuga canadensis (L.) Carrière, have been caused by hemlock woolly adelgid, Adelges tsugae (Annand) (HWA) (Hemiptera: Adelgidae). The current study is a retrospective analysis conducted in collaboration with Great Smoky Mountains National Park (GRSM) to determine longevity of imidacloprid and its insecticidal metabolites (imidacloprid olefin, 5-hydroxy, and dihydroxy) in GRSM's HWA integrated pest management (IPM) program. Foliage samples were collected from three canopy strata of hemlocks that were given imidacloprid basal drench treatments 4-7 yr prior to sampling. Foliage was analyzed to assess concentrations in parts per billion (ppb) of imidacloprid and its metabolites. Imidacloprid and its olefin metabolite were present in most, 95 and 65%, respectively, branchlets 4-7 yr post-treatment, but the 5-hydroxy and dihydroxy metabolites were present in only 1.3 and 11.7%, respectively, of the branchlets. Imidacloprid and olefin concentrations significantly decreased between 4 and 7 yr post-treatment. Concentrations of both imidacloprid and olefin were below the LC50 for HWA 5-7 yr post-treatment. Knowledge of the longevity of imidacloprid treatments and its metabolite olefin can help maximize the use of imidacloprid in HWA IPM programs. © 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.

Focusing of high-current electron beams and generation of superhard x radiation pulses; Fokusirovka sil`notochnykh puchkov ehlektronov i generatsiya impul`sov sverkhzhestkogo rentgenovskogo izlucheniya

Energy Technology Data Exchange (ETDEWEB)

Zinchenko, V F; Timofeev, V V; Shiyan, V D

1994-12-31

Diode geometry and target parameters necessary for optimization of fluence of photons from an X ray source with 1 MeV maximum electron energy are calculated. The basic parameters of the proposed X radiation source of a larger area are presented.

Variation in plant defense against invasive herbivores: evidence for a hypersensitive response in eastern hemlocks (Tsuga canadensis).

Science.gov (United States)

Radville, Laura; Chaves, Arielle; Preisser, Evan L

2011-06-01

Herbivores can trigger a wide array of morphological and chemical changes in their host plants. Feeding by some insects induces a defensive hypersensitive response, a defense mechanism consisting of elevated H(2)O(2) levels and tissue death at the site of herbivore feeding. The invasive hemlock woolly adelgid Adelges tsugae ('HWA') and elongate hemlock scale Fiorinia externa ('EHS') feed on eastern hemlocks; although both are sessile sap feeders, HWA causes more damage than EHS. The rapid rate of tree death following HWA infestation has led to the suggestion that feeding induces a hypersensitive response in hemlock trees. We assessed the potential for an herbivore-induced hypersensitive response in eastern hemlocks by measuring H(2)O(2) levels in foliage from HWA-infested, EHS-infested, and uninfested trees. Needles with settled HWA or EHS had higher H(2)O(2) levels than control needles, suggesting a localized hypersensitive plant response. Needles with no direct contact to settled HWA also had high H(2)O(2) levels, suggesting that HWA infestation may induce a systemic defense response in eastern hemlocks. There was no similar systemic defensive response in the EHS treatment. Our results showed that two herbivores in the same feeding guild had dramatically different outcomes on the health of their shared host.

Resonance absorption of nuclear gamma radiation; Absorption par resonance des rayons gamma; Rezonansnaya absorbtsiya i rasseyanie yadernogo gamma-izlucheniya; Absorcion por resonancia de las radiaciones gamma en los nucleos

Energy Technology Data Exchange (ETDEWEB)

Hanna, S S; Perlow, G J [Argonne National Laboratory, Argonne, IL (United States)

1962-01-15

radiacion do resonancia con y sin polarizacion. Estos estudios les han conducido a una interpretacion de la estructura hiperfina en funcion de las propiedades de los estados nucleares y de la interaccion hiperfina en el hierro. Tambien han investigado los efectos de un campo magnetico externo sobre la estructura hiperfina. Por otra parte, la absorcion por resonancia en el {sup 57}Fe permitio estudiar la relacion entre la cronologia de la desintegracion de im estado nuclear y el espectro de la radiacion observada. Se realizaron observaciones detalladas sobre el espectro de las radiaciones de resonancia filtradas, en funcion del tiempo, en condiciones muy diversas. (author) [Russian] Kak pokazal Messbauehr, ispuskanie i pogloshchenie yadernogo izlucheniya bez otdachi yadra obespechivaet prostoj metod izucheniya vzaimodejstviya yader s ehlektromagnitnym izlucheniem i, chto ochen' vazhno, yavlyaetsya chrezvychajno chuvstvitel'nym sredstvom issledovaniya bol'shogo kolichestva fizicheskikh zadach. V sluchae yader zheleza-57 sozdaetsya ves'ma blagopriyatnoe polozhenie, tak kak v ehtom sluchae rezonansnoe pogloshchenie mozhet ispol'zovat'sya v kachestve ochen' chuvstvitel'nogo detektora izmeneniya chastoty ehlektromagnitnogo izlucheniya. Detal'no izuchalos' rezonansnoe pogloshchenie v zheleze-57. Intensivnost' pogloshcheniya, forma i liniya sdviga nablyudalis' v zavisimosti ot temperatury. Polyarizatsiya radioaktivnogo izlucheniya nablyudalas' posredstvom ehksperimentov s namagnichennymi istochnikami i poglotitelyami. Sverkhtonkij spektr rezonansnoj radiatsii analizirovalsya s polyarizatsiej i bez nee. EHti issledovaniya priveli k tolkovaniyu sverkhtonkoj struktury v otnoshenii svojstv yadernykh sostoyanij i sverkhtonkogo vzaimodejstviya v zheleze. Bylo rassmotreno takzhe vliyanie vneshnego magnitnogo polya na sverkhtonkuyu strukturu. Rezonansnoe pogloshchenie v zheleze-57 bylo ispol'zovano dlya izucheniya svyazi mezhdu razvitiem raspada yadernogo sostoyaniya vo vremeni i spektrom

Disinfestation of Dried Figs by Gamma Radiation; Desinsectation des figues seches par les rayons gamma; Dezinfestatsiya sushenogo inzhira s pomoshch'yu gamma-izlucheniya'; Desinfestacion de higos secos mediante rayos gamma

Energy Technology Data Exchange (ETDEWEB)

Papadopoulou, C. P. [Department of Biology, Democritus Nuclear Research Centre, Aghia Paraskevi, Attica (Greece)

1963-09-15

efectuando investigaciones sobre la desinfestacion de los productos agricolas almacenados. En esas investigaciones se han utilizado recientemente con exito los rayos gamma. Los higos secos constituyen uno de los principales productos de exportacion de Grecia y los insectos ocasionan perdidas importantes. Las investigaciones tenian las siguientes finalidades: a) determinar las dosis de radiacion necesarias para destruir ciertas especies de insectos que atacan los higos en diversas fases de su desarrollo, o destruir sus huevos impidiendo asi que se reproduzcan; b) determinar las modificaciones fisicas y quimicas que las radiaciones producen en la contextura de los higos secos. Se han estudiado las especies siguientes: Plodia interpunctella, Ephestia cautella, Carpophilushemipterous, Oryzaephilus surinamensis y Lasioderma serricorne. En la memoria se estudian las dosis optimas de radiacion que no producen dafios aparentes en la contextura de los higos. (author) [Russian] V techenie mnogikh let provodyatsya issledovaniya to voprosam dezinfestatsii sel'skokhozyajstvennykh produktov v khranilishchakh. Nedavno gamma-izluchechie bylo uspeshno primeneno pri provedenii takikh issledovanij. Sushenyj inzhir sostavlyaet odin iz osnovnykh produktov ehksporta Gretsii. Ezhegodno nasekomye nanosyat ser'eznyj ushcherb ehtomu produktu. Tsel' issledovaniya: 1) opredelenie doz izlucheniya, neobkhodimykh dlya unichtozheniya nekotorykh vidov nasekomykh, porazhayushchikh sushenyj inzhir, na razlichnykh stadiyakh ikh razvitiya, i dlya unichtozheniya ikh yaits i predotvrashcheniya takim obrazom ikh razmnozheniya; i 2) opredelenie fiziko-khimicheskikh izmenenij tekstury sushenogo inzhira pod dejstviem izlucheniya. Issledovaniya provodilis' so sleduyushchimi vidami: Plodia Interpunctella, Ephestia coutella, Carpophilus hemipterous, Gryzaephllus surinamensis i Lasioderma serricorne. Obsuzhdayutsya neobkhodimye optimal'nye dozy. Pri ehtikh dozakh ne nablyudaetsya vidimogo narusheniya tekstury inzhira pod

Post-disturbance plant community dynamics following a rare natural-origin fire in a Tsuga canadensis forest.

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Bryan D Murray

Full Text Available Opportunities to directly study infrequent forest disturbance events often lead to valuable information about vegetation dynamics. In mesic temperate forests of North America, stand-replacing crown fire occurs infrequently, with a return interval of 2000-3000 years. Rare chance events, however, may have profound impacts on the developmental trajectories of forest ecosystems. For example, it has been postulated that stand-replacing fire may have been an important factor in the establishment of eastern hemlock (Tsuga canadensis stands in the northern Great Lakes region. Nevertheless, experimental evidence linking hemlock regeneration to non-anthropogenic fire is limited. To clarify this potential relationship, we monitored vegetation dynamics following a rare lightning-origin crown fire in a Wisconsin hemlock-hardwood forest. We also studied vegetation in bulldozer-created fire breaks and adjacent undisturbed forest. Our results indicate that hemlock establishment was rare in the burned area but moderately common in the scarified bulldozer lines compared to the reference area. Early-successional, non-arboreal species including Rubus spp., Vaccinium angustifolium, sedges (Carex spp., grasses, Epilobium ciliatum, and Pteridium aquilinium were the most abundant post-fire species. Collectively, our results suggest that competing vegetation and moisture stress resulting from drought may reduce the efficacy of scarification treatments as well as the usefulness of fire for preparing a suitable seedbed for hemlock. The increasing prevalence of growing-season drought suggests that silvicultural strategies based on historic disturbance regimes may need to be reevaluated for mesic species.

Ganoderma tsugae Extract Inhibits Growth of HER2-Overexpressing Cancer Cells via Modulation of HER2/PI3K/Akt Signaling Pathway

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Han-Peng Kuo

2013-01-01

Full Text Available Ganoderma, also known as Lingzhi or Reishi, has been used for medicinal purposes in Asian countries for centuries. It is a medicinal fungus with a variety of biological properties including immunomodulatory and antitumor activities. In this study, we investigated the molecular mechanisms by which Ganoderma tsugae (GT, one of the most common species of Ganoderma, inhibits the proliferation of HER2-overexpressing cancer cells. Here, we show that a quality assured extract of GT (GTE inhibited the growth of HER2-overexpressing cancer cells in vitro and in vivo and enhanced the growth-inhibitory effect of antitumor drugs (e.g., taxol and cisplatin in these cells. We also demonstrate that GTE induced cell cycle arrest by interfering with the HER2/PI3K/Akt signaling pathway. Furthermore, GTE curtailed the expression of the HER2 protein by modulating the transcriptional activity of the HER2 gene and the stability/degradation of the HER2 protein. In conclusion, this study suggests that GTE may be a useful adjuvant therapeutic agent in the treatment of cancer cells that highly express HER2.

DNA and Flavonoids Leach out from Active Nuclei of Taxus and Tsuga after Extreme Climate Stresses

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Walter Feucht

2015-09-01

Full Text Available Severe over-stresses of climate caused dramatic changes in the intracellular distribution of the flavonoids. This was studied in needles from the current year’s growth of the following species and varieties: Tsuga canadensis, Taxus baccata, T. aurea, T. repens, T. nana, and T. compacta. The mode of steady changes in flavonoids was evaluated by microscopic techniques. Most of the flavonoids stain visibly yellow by themselves. The colorless flavanol subgroup can be stained blue by the DMACA reagent. In mid-summer 2013, outstanding high temperatures and intense photo-oxidative irradiation caused in a free-standing tree of Taxus baccata dramatic heat damage in a limited number of cells of the palisade layers. In these cells, the cytoplasm was burned brown. However, the nucleus maintained its healthy “blue” colored appearance which apparently was a result of antioxidant barrier effects by these flavanols. In late May 2014, excessive rainfall greatly affected all study trees. Collectively, in all study trees, a limited number of the mesophyll nuclei from the needless grown in 2013 and 2014 became overly turgid, enlarged in size and the flavanols leached outward through the damaged nuclear membranes. This diffusive stress event was followed one to three days later by a similar efflux of DNA. Such a complete dissolution of the nuclei in young tissues was the most spectacular phenomenon of the present study. As a common feature, leaching of both flavanols and DNA was markedly enhanced with increasing size and age of the cells. There is evidence that signalling flavonoids are sensitized to provide in nuclei and cytoplasm multiple mutual protective mechanisms. However, this well-orchestrated flavonoid system is broken down by extreme climate events.

Growth and Its Relationship to Individual Genetic Diversity of Mountain Hemlock (Tsuga mertensiana at Alpine Treeline in Alaska: Combining Dendrochronology and Genomics

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Jeremy S. Johnson

2017-11-01

Full Text Available Globally, alpine treelines are characterized as temperature-limited environments with strong controls on tree growth. However, at local scales spatially heterogeneous environments generally have more variable impacts on individual patterns of tree growth. In addition to the landscape spatial heterogeneity there is local variability in individual tree genetic diversity (level of individual heterozygosity. It has been hypothesized that higher individual heterozygosity will result in more consistent patterns of growth. In this article, we combine genomics and dendrochronology to explore the relationship between individual genetic diversity and tree growth at a mountain hemlock (Tsuga mertensiana Bong. Carr alpine treeline on the Kenai Peninsula, Alaska, USA. We correlated average observed individual heterozygosity with average tree-ring width and variance in tree-ring width within individuals to test the hypothesis that trees with higher individual heterozygosity will also have more consistent growth patterns, suggesting that they may be more resilient to climate and environmental fluctuations at the alpine treeline. Our results showed that there was no significant relationship between tree growth and individual heterozygosity. However, there was a significant positive relationship between average tree-ring width and variance in tree-ring width implying that overall, fast growing trees in stressful environments, such as the alpine treeline, grow unstably regardless of the level of individual heterozygosity.

Ganoderma tsugae Induces S Phase Arrest and Apoptosis in Doxorubicin-Resistant Lung Adenocarcinoma H23/0.3 Cells via Modulation of the PI3K/Akt Signaling Pathway

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Yang-Hao Yu

2012-01-01

Full Text Available Ganoderma tsugae (GT is a traditional Chinese medicine that exhibits significant antitumor activities against many types of cancer. This study investigated the molecular mechanism by which GT suppresses the growth of doxorubicin-resistant lung adenocarcinoma H23/0.3 cells. Our results reveal that GT inhibits the viability of H23/0.3 cells in vitro and in vivo and sensitizes the growth suppression effect of doxorubicin on H23/0.3 cells. The data also show that GT induces S phase arrest by interfering with the protein expression of cyclin A, cyclin E, CDK2, and CDC25A. Furthermore, GT induces cellular apoptosis via induction of a mitochondria/caspase pathway. In addition, we also demonstrate that the suppression of cell proliferation by GT is through down-regulation of the PI3K/Akt signaling pathway. In conclusion, this study suggests that GT may be a useful adjuvant therapeutic agent in the treatment of lung cancer.

A new species of Laricobius (Coleoptera: Derodontidae) from Japan with phylogeny and a key for native and introduced congeners in North America

Science.gov (United States)

Montgomery Michael E.; S. Shiyake; Nathan P. Havill

2011-01-01

Laricobius osakensis Montgomery and Shiyake sp. nov., collected from Adelges tsugae Annand on hemlock [Tsuga sieboldii Carr. and Tsuga diversifolia (Maxim.) Mast.] in Japan, is described and illustrated. The new species was collected from several localities on Honshu, Shikokou, and Kyushu...

Response of Red-Backed Salamanders (Plethodon Cinereus to Changes in Hemlock Forest Soil Driven by Invasive Hemlock Woolly Adelgid (Adelges Tsugae

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Alison Ochs

2017-01-01

Full Text Available Hemlock forests of the northeastern United States are declining due to the invasive hemlock woolly adelgid (HWA (Adelges tsugae. Hardwood species replace these forests, which affects soil properties that may influence other communities, such as red-backed salamanders (red-backs (Plethodon cinereus. This study examined the effects of HWA invasion on soil properties and how this affects red-backs at the Hemlock Removal Experiment at Harvard Forest, which consists of eight 0.8 ha plots treated with girdling to simulate HWA invasion, logging to simulate common management practices, or hemlock- or hardwood-dominated controls. Coverboard surveys were used to determine the relative abundance of red-backs between plots during June and July 2014 and soil cores were collected from which the bulk density, moisture, pH, temperature, leaf litter, and carbon-nitrogen ratio were measured. Ordination provided a soil quality index based on temperature, pH, and carbon-to-nitrogen ratio, which was significantly different between plot treatments (p < 0.05 and showed a significant negative correlation with the red-back relative abundance (p < 0.05. The findings support the hypothesis that red-backs are affected by soil quality, which is affected by plot treatment and thus HWA invasion. Further studies should explore how salamanders react in the long term towards changing environments and consider the use of red-backs as indicator species.

Stylet bundle morphology and trophically related enzymes of the hemlock woolly adelgid (Hemiptera: Adelgidae)

Science.gov (United States)

Kelly L.F. Oten; Allen C. Cohen; Fred P. Hain

2014-01-01

The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is a pest of eastern and Carolina hemlocks (Tsuga canadensis (L.) Carriere and Tsuga caroliniana Engelmann, respectively) in the eastern United States and has already caused catastrophic changes to eastern forests. As one of the significant...

Maintenance of eastern hemlock forests: Factors associated with hemlock vulnerability to hemlock woolly adelgid

Science.gov (United States)

Mary Ann Fajvan; Petra Bohall Wood

2010-01-01

Eastern hemlock (Tsuga canadensis [L.]) is the most shade-tolerant and long-lived tree species in eastern North America. The hemlock woolly adelgid (Adelges tsugae) (HWA), is a nonnative invasive insect that feeds on eastern hemlock and Carolina hemlock (Tsuga caroliniana Engelm.). HWA currently is established in...

Prioritizing conservation seed banking locations for imperiled hemlock species using multi-attribute frontier mapping

Science.gov (United States)

John M. Hastings; Kevin M. Potter; Frank H. Koch; Mark Megalos; Robert M. Jetton

2017-01-01

Hemlock woolly adelgid (Adelges tsugae Annand) (HWA) is an invasive forest insect sweeping across the native range of eastern (Tsuga canadensis [L.] Carr.) and Carolina (Tsuga caroliniana Engelm.) hemlocks, threatening to severely reduce eastern hemlock extent and to push Carolina hemlock to extirpation. HWA poses a significant threat to these eastern US natives, now...

Hemlock woolly adelgid in the southern Appalachians: Control strategies, ecological impacts, and potential management responses

Science.gov (United States)

James M. Vose; David N. Wear; Albert E. Mayfield; C. Dana Nelson

2013-01-01

Hemlock woolly adelgid (Adelges tsugae Annad; or HWA) is a non-native invasive pest that attacks and kills eastern hemlock (Tsuga canadensis (L.) Carrière) and Carolina hemlock (Tsuga caroliniana Engelm.). Hemlock is a ‘‘foundation species’’ due to its strong influence on ecosystem structure and function,...

Prey suitability and phenology of Leucopis spp. (Diptera: Chamaemyiidae) associated with hemlock woolly adelgid (Hemiptera: Adelgidae) in the Pacific Northwest

Science.gov (United States)

Sarah M. Grubin; Darrell W. Ross; Kimberly F. Wallin

2011-01-01

Leucopis spp. (Diptera: Chamaemyiidae) from the Pacific Northwest previously were identified as potential biological control agents for the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), in the eastern United States. We collected Leucopis spp. larvae from A. tsugae...

Silvicultural and integrated pest management strategies for restoring eastern hemlock to degraded southern Appalachian mountain ecosystems.

Science.gov (United States)

W.A. Whittier; A.E. Mayfield III; R.M. Jetton

2017-01-01

The ecologically foundational species eastern hemlock, Tsuga canadensis, is being functionally eliminated from southern Appalachian forests by the hemlock woolly adelgid (HWA, Adelges tsugae). The management of HWA has focused on chemical and biological control, conservation of hemlock genetic resources, and host resistance...

Orientation behavior of the predator Laricobius nigrinus (Coleoptera: Derodontidae) to hemlock woolly adelgid and host tree odors in a multi-chambered olfactometer

Science.gov (United States)

Kimberly F. Wallin; Tanya M. Latty; Darrell W. Ross

2011-01-01

We studied the adult ambulatory response of the predator, Laricobius nigrinus Fender (Coleoptera: Derodontidae), to odors from its prey, Adelges tsugae Annand, the hemlock woolly adelgid, and foliage of hemlock woolly adelgid, host hemlocks (Tsuga spp.), and other conifers. Both the predator and hemlock woolly...

Using dendrochronology to model hemlock woolly adelgid effects on eastern hemlock growth and vulnerability

Science.gov (United States)

James Rentch; Mary Ann Fajvan; Richard Evans; Brad. Onken

2008-01-01

This study examined the relationship between eastern hemlock (Tsuga canadensis (L.) Carr.) crown condition and changes in radial growth associated with infestation by hemlock woolly adelgid (HWA), Adelges tsugae (Hemiptera: Adelgidae). Tree-ring chronologies of eastern hemlock were used to develop a binomial decline index based on...

Allozyme Variation in Hemlock Woolly Adelgid (Hemiptera: Adelgidae) from the United States and China

Science.gov (United States)

V. S& #225; nchez; M.A. Keena; M.A. Keena

2009-01-01

The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is a major introduced pest of eastern hemlock, Tsuga canadensis (L.) Carriere. Hemlock woolly adelgid in the United States is anholocyclic and an obligate parthenogen, because no suitable primary host (on which sexual reproduction occurs in Asia) is...

Vascular plant propagule banks of six eastern hemlock stands and potential response to the hemlock woolly adelgid in the Catskill Mountains of New York

Science.gov (United States)

Thad E. Yorks; Donald J. Leopold; Dudley J. Raynal

2000-01-01

We examined propagule banks in six eastern hemlock (Tsuga canadensis (L.) Carriere) stands in the Catskill Mountains of New York. These stands are at risk of mortality due to the hemlock woolly adelgid (Adelges tsugae Annand), but potential effects of mortality on species composition are uncertain.

Vegetation and invertebrate community response to eastern hemlock decline in southern new England

Science.gov (United States)

Laura L. Ingwell; Mailea Miller-Pierce; R. Talbot Trotter; Evan L. Preisser

2012-01-01

The introduction of Adelges tsugae (Hemlock Woolly Adelgid [HWA]) to the eastern United States has had a devastating impact on Tsuga canadensis (Eastern Hemlock). Although much research has been done to assess HWA impacts on ecosystem processes and vegetation structure, few researchers have examined community-level changes in...

Impacts of Hemlock Loss on Nitrogen Retention Vary with Soil Nitrogen Availability in the Southern Appalachian Mountains

Science.gov (United States)

Corinne E. Block; Jennifer D. Knoepp; Katherine J. Elliott; Jennifer M. Fraterrigo

2012-01-01

The impacts of exotic insects and pathogens on forest ecosystems are increasingly recognized, yet the factors influencing the magnitude of effects remain poorly understood. Eastern hemlock (Tsuga canadensis) exerts strong control on nitrogen (N) dynamics, and its loss due to infestation by the hemlock woolly adelgid (Adelges tsugae...

Imidacloprid movement in soils and impacts on soil microarthropods in southern Appalachian eastern hemlock stands

Science.gov (United States)

Jennifer D. Knoepp; James M. Vose; Jerry L. Michael; Barbara C. Reynolds

2012-01-01

Imidacloprid is a systemic insecticide effective in controlling the exotic pest Adelges tsugae (hemlock woolly adelgid) in eastern hemlock (Tsuga canadensis) trees. Concerns over imidacloprid impacts on nontarget species have limited its application in southern Appalachian ecosystems. We quantified the movement and adsorption of imidacloprid in forest soils after soil...

A landscape-scale remote sensing/GIS tool to assess eastern hemlock vulnerability to hemlock woolly adelgid-induced decline

Science.gov (United States)

Jennifer Pontius; Richard Hallett; Mary Martin; Lucie. Plourde

2010-01-01

The hemlock woolly adelgid (Adelges tsugae Annand) (HWA) is an invasive insect pest that is causing widespread mortality of eastern hemlock (Tsuga canadensis (L.) Carr.). However, some stands remain living more than a decade after infestation. The ability to target management efforts in locations where hemlock is most likely to...

Use of water by eastern hemlock: implications for systemic insecticide application

Science.gov (United States)

Chelcy R. Ford; James M. Vose; Michael Daley; Nathan Phillips

2007-01-01

The hemlock woolly adelgid (HWA, Adelges tsugae Annand) is causing widespread decline and mortality of eastern hemlock (Tsuga canadensis (L.) Carr.) throughout most of the range of eastern hemlock. Stem injection of insecticide is widely used as a chemical control measure, but the effectiveness of this method depends on the...

Hemlock woolly adelgid (Homoptera: Adelgidae): stylet bundle insertion and feeding sites

Science.gov (United States)

Rebecca F. Young; Kathleen S. Shields; Graeme P. Berlyn

1995-01-01

Stylet bundle insertion site, path traveled, and feeding site were examined for the hemlock woolly adelgid, Adelges tsugae Annand, on needles from current and previous years of eastern hemlock, Tsuga canadensis Carriere. The stylet bundle is composed of 4 individual stylets--2 outer mandibular stylets and 2 inner maxillary stylets...

Long-term structural and biomass dynamics of virgin Tsuga canadensis-Pinus strobus forests after hurricane disturbance.

Science.gov (United States)

D'Amato, Anthony W; Orwig, David A; Foster, David R; Barker Plotkin, Audrey; Schoonmaker, Peter K; Wagner, Maggie R

2017-03-01

The development of old-growth forests in northeastern North America has largely been within the context of gap-scale disturbances given the rarity of stand-replacing disturbances. Using the 10-ha old-growth Harvard Tract and its associated 90-year history of measurements, including detailed surveys in 1989 and 2009, we document the long-term structural and biomass development of an old-growth Tsuga canadensis-Pinus strobus forest in southern New Hampshire, USA following a stand-replacing hurricane in 1938. Measurements of aboveground biomass pools were integrated with data from second- and old-growth T. canadensis forests to evaluate long-term patterns in biomass development following this disturbance. Ecosystem structure across the Tract prior to the hurricane exhibited a high degree of spatial heterogeneity with the greatest levels of live tree basal area (70-129 m 2 /ha) on upper west-facing slopes where P. strobus was dominant and intermixed with T. canadensis. Live-tree biomass estimates for these stratified mixtures ranged from 159 to 503 Mg/ha at the localized, plot scale (100 m 2 ) and averaged 367 Mg/ha across these portions of the landscape approaching the upper bounds for eastern forests. Live-tree biomass 71 years after the hurricane is more uniform and lower in magnitude, with T. canadensis currently the dominant overstory tree species throughout much of the landscape. Despite only one living P. strobus stem in the 2009 plots (and fewer than five stems known across the entire 10-ha area), the detrital legacy of this species is pronounced with localized accumulations of coarse woody debris exceeding 237.7-404.2 m 3 /ha where this species once dominated the canopy. These patterns underscore the great sizes P. strobus attained in pre-European landscapes and its great decay resistance relative to its forest associates. Total aboveground biomass pools in this 71-year-old forest (255 Mg/ha) are comparable to those in modern old-growth ecosystems

Phenology of the Hemlock Woolly Adelgid (Hemiptera: Adelgidae) in Northern Georgia

Science.gov (United States)

Shimar V. Joseph; Albert E. Mayfield; Mark J. Dalusky; Christopher Asaro; C. Wayne. Berisford

2011-01-01

Understanding the seasonal phenology of an insect pest in a specific geographic region is essential for optimizing the timing of management actions or research activities. We examined the phenology of hemlock woolly adelgid, Adelges tsugae Annand, near the southern limit of the range of eastern hemlock, Tsuga canadensis (L.) Carriere, in the Appalachians of northern...

Variation in winter survival of the invasive hemlock woolly adelgid (Hemiptera: Adelgidae) across the eastern United States

Science.gov (United States)

R. Talbot, III Trotter; Kathleen S. Shields

2009-01-01

The hemlock woolly adelgid (Adelges tsugae Annand) is a small, aphid-like insect native to East Asia and western North America. First documented in the eastern United States in Richmond, VA, in 1951, it has spread to at least 17 states, where it causes increased mortality among both eastern and Carolina hemlocks (Tsuga canadensis...

Influences of eastern hemlock mortality on nutrient cycling

Science.gov (United States)

Thad E. Yorks; Jennifer C. Jenkins; Donald J. Leopold; Dudley J. Raynal; David A. Orwig

2000-01-01

Mortality of eastern hemlock (Tsuga canadensis (L.) Carriere) may be caused by a variety of agents, but hemlock trees of all sizes over a large geographic area are currently threatened by an outbreak of the hemlock woolly adelgid (HWA: Adelges tsugae Annand) in the eastern United States. In this paper, we review what is currently...

Abundance of Armillaria within old-growth eastern hemlock stands in South-Central Pennsylvania

Science.gov (United States)

Matthew S. Fromm; Donald D. Davis

2007-01-01

Abstract—In early summer 2002, 329 soil-sampling pits were dug within an old-growth, eastern hemlock (Tsuga canadensis [L.] Carrière) stand in south-central Pennsylvania recently infested with the hemlock woolly adelgid (Adelges tsugae Annand). For comparison, 199 similar pits were dug in an adjacent hardwood stand. Rhizomorphs of...

Using climate and genetic diversity data to prioritize conservation seed banking for imperiled hemlock species

Science.gov (United States)

J.M. Hastings; K.M. Potter; F.H. Koch; M.A. Megalos; R.M. Jetton

2017-01-01

Hemlock woolly adelgid (HWA, Adelges tsugae) is an invasive forest insect that has caused mortality of eastern (Tsuga canadensis) and Carolina hemlock (T. caroliniana) at an alarming rate. Now infesting 19 states and over 400 counties of the eastern United States, HWA poses a significant threat to native host species. The current biological and chemical methods for...

Host Range Specificity of Scymnus camptodromus (Coleoptera: Coccinellidae), A Predator of Hemlock Woolly Adelgid (Hemiptera: Adelgidae).

Science.gov (United States)

Limbu, Samita; Cassidy, Katie; Keena, Melody; Tobin, Patrick; Hoover, Kelli

2016-02-01

Scymnus (Neopullus) camptodromus Yu and Liu (Coleoptera: Coccinellidae) was brought to the United States from China as a potential biological control agent for hemlock woolly adelgid (Adelges tsugae Annand) (Hemiptera: Adelgidae). Scymnus camptodromus phenology is closely synchronized with that of A. tsugae and has several characteristics of a promising biological control agent. As a prerequisite to field release, S. camptodromus was evaluated for potential nontarget impacts. In host range studies, the predator was given the choice of sympatric adelgid and nonadelgid prey items. Nontarget testing showed that S. camptodromus will feed to some degree on other adelgid species, but highly prefers A. tsugae. We also evaluated larval development of S. camptodromus on pine bark adelgid (Pineus strobi (Hartig)) (Hemiptera: Adelgidae) and larch adelgid (Adelges laricis Vallot) (Hemiptera: Adelgidae); a small proportion of predator larvae was able to develop to adulthood on P. strobi or A. laricis alone. Scymnus camptodromus showed no interest in feeding on woolly alder aphid (Paraprociphilus tessellatus Fitch) (Hemiptera: Aphididae) or woolly apple aphid (Eriosoma lanigerum (Hausmann)) (Hemiptera: Aphididae), and minimal interest in cotton aphid (Aphis gossypii Glover) (Hemiptera: Aphididae) in choice and no-choice experiments. Scymnus camptodromus females did not oviposit on any host material other than A. tsugae-infested hemlock. Under the circumstances of the study, S. camptodromus appears to be a specific predator of A. tsugae, with minimal risk to nontarget species. Although the predator can develop on P. strobi, the likelihood that S. camptodromus would oviposit on pine hosts of this adelgid is small.

Expansion of Protected Areas under Climate Change: An Example of Mountainous Tree Species in Taiwan

Directory of Open Access Journals (Sweden)

Wei-Chih Lin

2014-11-01

Full Text Available Tree species in mountainous areas are expected to shift their distribution upward in elevation in response to climate change, calling for a potential redesign of existing protected areas. This study aims to predict whether or not the distributions of two high-mountain tree species, Abies (Abies kawakamii and Tsuga (Tsuga chinensis var. formosana, will significantly shift upward due to temperature change, and whether current protected areas will be suitable for conserving these species. Future temperature change was projected for 15 different future scenarios produced from five global climate models. Shifts in Abies and Tsuga distributions were then predicted through the use of species distribution models (SDMs which included occurrence data of Abies and Tsuga, as well as seasonal temperature, and elevation. The 25 km × 25 km downscaled General Circulation Model (GCMs data for 2020–2039 produced by the Taiwan Climate Change Projection and Information Platform was adopted in this study. Habitat suitability in the study area was calculated using maximum entropy model under different climatic scenarios. A bootstrap method was applied to assess the parameter uncertainty of the maximum entropy model. In comparison to the baseline projection, we found that there are significant differences in suitable habitat distributions for Abies and Tsuga under seven of the 15 scenarios. The results suggest that mountainous ecosystems will be substantially impacted by climate change. We also found that the uncertainty originating from GCMs and the parameters of the SDM contribute most to the overall level of variability in species distributions. Finally, based on the uncertainty analysis and the shift in habitat suitability, we applied systematic conservation planning approaches to identify suitable areas to add to Taiwan’s protected area network.

Autofluorography with an X-Ray Image Amplifier; Autofluorographie a l'Aide d'un Amplificateur d'Images a Rayons X; Avtofl u orografiya s pomoshch'yu usilitelya rentgenovskogo izobrazheniya; Autofluorografia con un Amplificador de Imagen de Rayos X

Energy Technology Data Exchange (ETDEWEB)

Ter-Pogossian, M. M.; Eichling, J. O. [Washington University School of Medicine, St. Louis, MO (United States)

1964-10-15

traitent de l'utilite de ce dispositif pour la visualisation des tumeurs du cerveau, des reins et de la thyroide. (author) [Spanish] La visualizacion de organos que contienen isotopos radiactivos emisores de fotones (rayos X o gamma) de energia comprendida entre 20 y 100 keV aproximadamente, puede lograrse convirtiendo en luz, mediante un amplificador de imagen de rayos X de tipo corriente, la radiacion emitida por el organo. El aparato construido con esta finalidad esta constituido por los siguientes elementos: 1. Un colimador, cuyas caracteristicas vienen determinadas por el poder de resolucion y la distancia a que debe operar. 2. Un amplificador de imagen de rayos X de enfoque electrostatico, que convierte los rayos X o gamma colimados en una imagen optica muy brillante. 3. Un sistema de lentes de gran apertura que proyecta la imagen en la camara mencionada a continuacion. 4. Una camara 'Polaroid' cargada con pelicula rapida (10 000 ASA) de gran contraste. El rendimiento de este aparato para fotones de baja energia es superior al de los exploradores centelleograficos de tipo tradicional. Los autores examinan su utilidad para visualizar tumores cerebrales, renales y tiroideos. (author) [Russian] Vizual'noe nabljudenie organov, soderzhashhih radioaktivnye izotopy, kotorye i z luchajut rentgenovskie kvanty ili gamma-kvanty s jenergijami v predelah ot 20 do 100 kjev, do stiga et sja za schet prevrashhenija radiacii organa v svechenie s pomoshh'ju usilitelja rentgenovskogo izobrazhenija obychnogo tipa. Skonstruirovannyj dlja jetoj celi apparat sostoit iz sledujushhih jelementov: 1 . Kollimatora, harakteristiki kotorogo opredeljajutsja razreshajushhej sposobnost'ju i zh e laemym rabochim rasstojaniem. 2 . Jelektrostaticheskogo fokusirujushhego usilitelja r ent genov skogo izobrazhenija, kotoryj prevrashhaet kollimirovannye rentgenovskie kvanty ili gamma-kvanty v opticheskoe izobrazhenie, imejushhee bol'shuju jarkost'. 3 . Ob{sup e}ktiva s bol'shoj diafragmoj, kotoryj

Using the hot carrier injection into sub gate oxide and the x-radiation effect for forecasting the working capacity of MOS-technology microcircuits; Ispol`zovanie inzhektsii goryachikh nositelej v podzatvornyj okisel i vozdejstvii rentgenovskogo izlucheniya dlya prognozirovaniya mikroskhem, izgotovlennykh po MOP-tekhnologii

Energy Technology Data Exchange (ETDEWEB)

Pershenkov, V S; Cheredko, S V

1994-12-31

Analysis of the method of forecasting the threshold strain degradation during active functioning of MOST using ionizing radiation is conducted. Problems of practical application of the method and its modification for determining the MOST working capacity under low-intensity radiation effect are discussed.

New developments in the analysis and measurement of thicknesses by {beta}-particle excitation of X fluorescent rays; Nouveaux developpements de l'analyse et de la mesure des epaisseurs par excitation des raies de fluorescence X au moyen de particules {beta}; Novye usovershenstvovaniya analiza i izmereniya plotnosti putem vozbuzhdeniya fluorestsiruyushchikh spektrov rentgenovskogo lucha beta-chastitsami; Nuevos adelantos en el analisis y la medicion de espesores mediante la excitacion de rayos X por particulas beta

Energy Technology Data Exchange (ETDEWEB)

Martinelli, P [Commissariat a l' Energie Atomique, Saclay (France); Seibel, G [Institut de Recherches de la Siderurgie, St-Germain-en-Laye (France)

1962-01-15

kriptona-85 daet vozmozhnost' umen'shit' fon, kotoryj nablyudaetsya pri ispol'zovanii strontsiya-90. Privodyatsya dannye, poluchennye dlya razlichnykh izmerenij plotnosti metallicheskikh sloev, analiz rastvorov i nepreryvnoe izmerenie kal'tsiya i zheleza v rudnykh porodakh. Daetsya opisanie opytov, provedennykh s tsel'yu analiza rentgenovskogo oblucheniya s pomoshch'yu kristalla. (author)

Difference in photosynthetic performance among three peach ...

African Journals Online (AJOL)

Administrator

2011-02-21

Feb 21, 2011 ... Difference in photosynthesis rate (Pn) and stoma morphology among ... At 80% PPFD, the variation pattern of ribulose bisphosphate carboxylase ..... frequency and size during elongation of tsuga heterophylla needles.

Radioinitiation of Chain Branched Reactions and its Sensitization; Amorcage sous rayonnement des reactions par ramification en chaine; sensibilisation du processus; Radiatsionnoe initsiirovanie tsennykh razvetvlennykh reaktsij i ego sensibilizatsiya; Radioiniciacion de reacciones en cadena ramificadas y medios para aumentar su sensibilidad

Energy Technology Data Exchange (ETDEWEB)

Barelko, E V; Kartashova, L I; Komarov, P N; Proskurnin, M A [Karpov Physico-Chemical Institute, Moscow, Union of Soviet Socialist Republics (Russian Federation)

1960-07-15

fondamentales de la reaction d'oxydation par radiolyse du benzene : accumulation des divers produits de la reaction, action de la temperature, de la pression, de la puissance et de la dose d'irradiation sur le processus d'accumulation des produits de la reaction. Quelques conclusions sont exposees sur le mecanisme de la reaction. Les auteurs decrivent la construction de l'installation qui fonctionne en circuit ferme. (author) [Spanish] Figuran en esta memoria los resultados de los trabajos efectuados por los autores sobre la radioiniciacion de las reacciones de oxidacion de compuestos organicos en cadenas ramificadas. Se demuestra el papel que desempenan las radiaciones como agente de iniciacion, tomando como ejemplo la oxidacion del butanol y de varios hidrocarburos no saturados. La reaccion tiene caracter autoacelerador y prosigue espontaneamente al cesar la irradiacion. Se ha estudiado detalladamente el proceso de oxidacion del benceno, compuesto que se caracteriza por una elevada resistencia a las radiaciones. Los autores han ideado un metodo para sensibilizar la radioiniciacion de la oxidacion de compuestos radioresistentes por sustancias quimicamente inertes, pero inestables frente a las radiaciones. En la memoria se examinan los principales factores de que depende la radiooxidacion del benceno, a saber, concentracion de los distintos productos de reaccion e influencia de la temperatura, de la presion, de la energia y de la dosis de radiacion en el proceso de acumulacion de esos productos. Los autores formulan tambien algunas conclusiones sobre el mecanismo del proceso y describen la construccion de la instalacion de circulacion. (author) [Russian] V doklade predstavleny rezul'taty issledovanij avtorov po radiatsionnomu initsiirovaniyu tsepnykh razvetvlennykh reaktsij okisleniya organicheskikh soedinenij. Na primere okisleniya nekotorykh nenasyshchennykh uglevodorodov i butanola pokazana rol' izlucheniya kak initsiiruyushchego agenta. Reaktsiya imeet

NCRN Hemlock Inventory Data

Data.gov (United States)

Department of the Interior — ​Data associated with the 2015 hemlock inventory project in NCR. Eastern hemlock (Tsuga canadensis) is a coniferous tree native to the NE and Appalachian regions of...

Responses of southeast Alaska understory species to variation in light and soil environments

Science.gov (United States)

Thomas A. Hanley; Bernard T. Bormann; Jeffrey C. Barnard; S. Mark Nay

2014-01-01

Aboveground growth rates of seedlings of bunchberry (Cornus canadensis L.), oval-leaf blueberry (Vaccinium ovalifolium Sm.), salmonberry (Rubus spectabilis Pursh), devilsclub (Oplopanax horridus (Sm.) Miq.), and western hemlock (Tsuga heterophylla (Raf.) Sarg.) were...

Scymnus camptodromus (Coleoptera: Coccinellidae) larval development and predation of hemlock woolly adelgid (Hemiptera: Adelgidae)

Science.gov (United States)

Samita Limbu; Melody A. Keena; David Long; Nancy Ostiguy; Kelli. Hoover

2015-01-01

Development time and prey consumption of Scymnus (Neopullus) camptodromus Yu and Liu (Coleoptera: Coccinellidae) larvae by instar, strain, and temperature were evaluated. S. camptodromus, a specialist predator of hemlock woolly adelgid Adelges tsugae (Annand) (Hemiptera:...

Spatial and population characteristics of dwarf mistletoe infected trees in an old-growth Douglas-fir - western hemlock forest.

Science.gov (United States)

David C. Shaw; Jiquan Chen; Elizabeth A. Freeman; David M. Braun

2005-01-01

We investigated the distribution and severity of trees infected with western hemlock dwarf mistletoe (Arceuthobium tsugense (Rosendahl) G.N. Jones subsp. tsugense) in an old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) - western hemlock (Tsuga heterophylla (Raf.) Sarg.)...

Silicon-lithium nuclear radiation detectors. Kremnii-litievye detektory yadernogo izlucheniya

Energy Technology Data Exchange (ETDEWEB)

Azimov, S.A.; Muminov, R.A.; Shamirzaev, S.Kh.; Yafasov, A.Ya.

1981-01-01

A presentation is made of the physical principles underlying the design, building, and technology of silicon-lithium detectors and ways of improving them. Criteria of nuclear radiation control and selection and the connection between radiation and detector properties are discussed. A study is made of the effect that various defects have on the process of charge collection and formation of amplitude spectra during the recording of various types of particles. A detailed examination is made of the optimal technological systems for making detectors with high energy and time resolutions, and features of producing high-quality detectors which employ the use of ion-laser and other methods of modern semiconductor technology. 322 references, 102 figures, 2 tables.

Assessment of the potential for hybridisation between Laricobius nigrinus (Coleoptera: Derodontidae) and Laricobius osakensis, predators of the hemlock woolly adelgid (Hemiptera: Adelgidae)

Science.gov (United States)

Melissa J. Fischer; Carlyle C. Brewster; Nathan P. Havill; Scott M. Salom; Loke T. Kok

2015-01-01

In 2003, Laricobius nigrinus Fender was introduced into the eastern United States as a biological control agent of the hemlock woolly adelgid (Adelges tsugae Annand). Following its release, it was discovered that L. nigrinus was hybridising and producing viable progeny with Laricobius rubidus...

Preliminary test of two stump surface protectants against Fomes annosus.

Science.gov (United States)

E.E. Nelson; C.Y. Li

1980-01-01

Two materials, monolaurin (at two concentrations) and an unidentified species of the genus Streptomyces, were tested along with borax for ability to protect freshly cut stump surfaces of western hemlock (Tsuga heterophylla (Raf.) Sarg.) from colonization by Fomes annosus. Protectants were significantly (P...

Nuclei of plants as a sink for flavanols.

Science.gov (United States)

Feucht, W; Polster, J

2001-01-01

Onion cepa (L.) and Tsuga canadensis (L.) Carr. were investigated histochemically on the association of flavanols to nuclei. The young roots of Onion cepa are totally devoid of flavanol structures. Therefore, the excised roots tips were directly incubated into different solutions of flavanols. After 3 h of incubation a flavanol binding on the nuclei was recognizable, as seen by a yellowish-brown tanning reaction. Still to ensure the presence of flavanols on the nuclei, subsequent staining with the p-dimethylaminocinnamaldehyde reagent (DMACA) resulted in an intense blue colouration. Tsuga canadensis has significant amounts of vacuolar flavanol deposits in all parts of the tree as indicated by the DMACA reagent. It is obvious that also the nuclei were associated strongly with flavanols which can be demonstrated particularly elegant in the cells of the seed wings by histochemical methods. However, the mode of flavanol release from the original deposits is not yet clear.

Ethylene Polymerization by Gamma Irradiation; Polymerisation de l'ethylene par irradiation; Polimerizatsiya ehtilen a pod vliyaniem gamma-izlucheniya; Polimerizacion del etileno por irradiacion gamma

Energy Technology Data Exchange (ETDEWEB)

Medvedev, S S; Abkin, A D; Khomikovsky, P M [Fiziko-khimicheskij institut im. Karpova, SSSR, Moscow, Union of Soviet Socialist Republics (Russian Federation)

1960-07-15

presion del etileno (50-300 atmosferas), la dosis especifica (20-160 roentgens/segundo) y la temperatura (0-50{sup o}C). La velocidad del proceso, el rendimiento quimico obtenido por radioinduccion y el peso molecular medio de los polimeros aumentan considerablement e con la presion (entre 50 y 200 atmosferas, la velocidad de polimerizacion es proporcional a la cuarta potencia de la concentracion de etileno). La velocidad de polimerizacion depende poco de la dosis especifica, siendo proporcional a la intensidad de irradiacion elevada a la potencia 0,3, en tanto que el rendimiento quimico obtenido por radioinduccion y el peso molecular medio de los polimeros aumentan a medida que la dosis especifica disminuye. La velocidad del proceso y el peso molecular aumentan ligeramente al crecer la temperatura. Los autores estudian las posibles explicaciones de las leyes cineticas observadas. El polietileno obtenido por irradiacion se distingue del polimero producido a presiones elevadas por su mayor densidad y grado de cristalizacion. En lo que se refiere a sus propiedades mecanicas, el polimero de viscosidad intrinseca superior a la unidad (obtenido a presiones comprendidas entre 100 y 200 atmosferas) se asemeja al polietileno producido a presiones elevadas. (author) [Russian] Issledovan protsess radiatsionnoj polimerizatsii ehtilena. S tsel'yu uvelicheniya skorosti initsiirovaniya provedeno izuchenie polimerizatsii ztilena v rastvorakh organicheskikh veshchestv (spirty, atseton, alifaticheskie uglevodorody) i pokazano, chto pri postoyannom davlenii (50 atm) i komnatnoj temperature skorost' protsessa v rastvore v 10-15 raz vyshe, chem v gazovoj faze. Detal'no izuchen protsess polimerizatsii ehtilena pod vliyaniem izlucheniya kobal'ta{sup -60} v gaze v zavisimosti ot davleniya ehtilena (50-300 atm), moshchnosti dozy (20-160 rentg/sek) i temperatury (0-50{sup o}C). Skorost' protsessa, radiatsionno-khimicheskij vykhod i srednij molekulyarnyj ves polimerov rezko vozrastayut s davleniem

Weyerhaeuser Export Facility at DuPont. Volume I.

Science.gov (United States)

1982-05-01

exists on the DuPont site, in which the most common trees are lodgepole pine ( Pinus contorta) and western hemlock (Tsuga heterophtlla). Bog birch (Betula...Weyerhaeuser production facilities and storage at the proposed export facility. Tropolone methyl ethers have also been mentioned as potential contam

Aluminum solubility and mobility in relation to organic carbon in surface soils affected by six tree species of the northeastern United States

NARCIS (Netherlands)

Dijkstra, F.A.; Fitzhugh, R.D.

2003-01-01

We compared Al solubility and mobility in surface soils among six tree species (sugar maple [Acer saccharum], white ash [Fraxinus americana], red maple [Acer rubrum, L.], American beech [Fagus grandifolia, Ehrh.], red oak [Quercus rubra, L.], and hemlock [Tsuga canadensis, Carr.]) in a mixed

Developing Biomass Equations for Western Hemlock and Red Alder Trees in Western Oregon Forests

Science.gov (United States)

Krishna Poudel; Hailemariam Temesgen

2016-01-01

Biomass estimates are required for reporting carbon, assessing feedstock availability, and assessing forest fire threat. We developed diameter- and height-based biomass equations for Western hemlock (Tsuga heterophylla (Raf.) Sarg.) and red alder (Alnus rubra Bong.) trees in Western Oregon. A system of component biomass...

Cryptic east-west divergence and molecular diagnostics for two species of silver flies (Diptera: Chamaemyiidae: Leucopis ) from North America being evaluated for biological control of hemlock woolly adelgid

Science.gov (United States)

Nathan P. Havill; Stephen D. Gaimari; Adalgisa. Caccone

2018-01-01

Exploring genetic diversity within species of biological control agents can expose previously overlooked beneficial genotypes. This may be the case for two species of silver flies, Leucopis argenticollis and L. piniperda, predators of the hemlock woolly adelgid (Adelges tsugae) in the Pacific Northwest of...

Seasonal food selection and digestibility by tame white-tailed deer in central Maine

Science.gov (United States)

Hewlette S. Crawford

1982-01-01

Seasonal food selection and digestibility by tame white-tailed deer (Odocoileus virginianus) were studied in the white pine (Pinus strobus)–Canada hemlock (Tsuga canadensis) and lowland conifer types, areas representative of important deer habitat in the northeastern United States. Deer selected highly...

Effect of Gamma Radiation on Polyethyl Acrylate; Effet des rayons gamma sur le polyethylacrylate; Dejstvie gamma-izlucheniya na akrilat poliehtila; Efectos de las radiaciones gamma sobre el poliacrilato de etilo

Energy Technology Data Exchange (ETDEWEB)

Heyns, H; Desreux, V [Laboratory of Physical Chemistry, University of Liege (Belgium)

1960-07-15

polymere. L'influence de l'oxygene ou d'inhibiteurs est etudiee. Des irradiations ont ete egalement faites a l'etat solide. Elles montrent que dans ce cas il y a reticulation que ce soit en presence ou en absence d'oxygene. Cette reticulation est accompagnee d'une degradation plus ou moins importante suivant les cas. Enfin des essais faits en solutions concentrees dans le tetrachlorure de carbone montrent que dans ce cas il y a competition entre la degradation et la reticulation. (author) [Spanish] Los autores estudiaron los efectos ejercidos por las radiaciones emitidas por el cobalto-60 sobre muestras de poliacrilato de etilo de diferentes pesos moleculares, en estado solido y disueltas en benceno y tetracloruro de carbono; los ensayos se realizaron a la temperatura ambiente en ausencia y en presencia de aire. Los autores no observaron efecto de postirradiacion alguno. Al irradiar soluciones diluidas con dosis crecientes de rayos gamma en presencia de aire, comprobaron que la viscosidad intrinseca y la constante de sedimentacion experimentan una disminucion. Los resultados obtenidos pueden interpretarse admitiendo que se produce una degradacion de las moleculas de poliacrilato de etilo. Tanto el efecto directo como el indirecto son proporcionales a la dosis y varian segun el disolvente. Ambos son directamente proporcionales al peso molecular inicial del polimero. Los autores estudieron la influencia oxigeno y de algunos agentes inhibidores. Tambien han sometido a irradiacion muestras en estado solido. En este caso, la reticulacion se produce tanto en presencia como en ausencia de oxigeno. Esta reticulacion va acompanada de una degradacion de importancia variable. Por otra parte, los ensayos realizados con soluciones concentradas de poliacrilato de etilo en tetracloruro de carbono demuestran que el proceso de degradacion compite con el de reticulacion. (author) [Russian] Avtory izuchayut dejstvie izlucheniya kobal'ta-60 na obraztsy akrilata poliehtila s razlichnym

Predators collected from balsam woolly adelgid and Cooley spruce gall adelgid in western Oregon and Washington, U.S.A., with reference to biological control of hemlock woolly adelgid (Hemiptera: Adelgidae)

Science.gov (United States)

Darrell W. Ross; Glenn R. Kohler; Kimberly F. Wallin

2017-01-01

As part of a comprehensive study to survey predators associated with hemlock woolly adelgid, Adelges tsugae Annand, 1928 in the Pacific Northwest (PNW), U.S.A. (Kohler et al. 2008), predators of balsam woolly adelgid, Adelges piceae (Ratzeburg, 1844) and Cooley spruce gall adelgid, Adelges cooleyi (Gillette...

Previsual detection of two conifer-infesting adelgid species in North American forest

Science.gov (United States)

Stephen Cook; Karen Humes; Ryan Hruska; Christopher Williams; Grant Fraley

2010-01-01

The balsam woolly adelgid, Adelges piceae, and hemlock woolly adelgid, A. tsugae (Homoptera: Adelgidae), are invasive pests of coniferous forests in both the Eastern and Western United States. Balsam woolly adelgid is capable of attacking and killing native North American firs, with Fraser fir (Abies fraseri...

Tree species effects on calcium cycling: The role of calcium uptake in deep soils

NARCIS (Netherlands)

Dijkstra, F.A.; Smits, M.M.

2002-01-01

Soil acidity and calcium (Ca) availability in the surface soil differ substantially beneath sugar maple (Acer saccharum) and eastern hemlock (Tsuga canadensis) trees in a mixed forest in northwestern Connecticut. We determined the effect of pumping of Ca from deep soil (rooting zone below 20-cm

Growth and yield of all-aged Douglas-fir -- western hemlock forest stands: a matrix model with stand diversity effects.

Science.gov (United States)

Jingjing Liang; Joseph Buonglorno; Robert A. Monserud

2005-01-01

A density-dependent matrix model was developed for Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) -- western hemlock (Tsuga heterophylla (Raf.) Sarg.) forest stands in the Pacific Northwest of the United States. The model predicted the number and volume of trees for 4 species groups and 19 diameter classes. The parameters...

Residual densities affect growth of overstory trees and planted Douglas-fir, western hemlock, and western redcedar: results from the first decade

Science.gov (United States)

Leslie Chandler Brodie; Dean S. DeBell

2013-01-01

In recent years, interest has increased in silvicultural systems and harvest cuts that retain partial overstories, but there are few data available on the growth of the understory trees in such stands. We studied the response of overstory trees and underplanted seedlings, Douglas-fir (Pseudotsuga menziesii), western hemlock (Tsuga...

Gypsy moth IPM

Science.gov (United States)

Michael L. McManus; Andrew M. Liebhold

2009-01-01

Over the last 50 years, North American forests have been inundated by a multitude of alien pest invasions. Among these, noteworthy invaders include the hemlock woolly adelgid (Adelges tsugae), emerald ash borer (Agrilus planipennis), chestnut blight and Dutch elm disease. These species have greatly altered both the ecological and...

Changes to southern Appalachian water yield and stormflow after loss of a foundation species

Science.gov (United States)

Steven T. Brantley; Chelcy Ford Miniat; Katherine J. Elliott; Stephanie H. Laseter; James M. Vose

2014-01-01

Few studies have examined how insect outbreaks affect landscape-level hydrologic processes. We report the hydrologic effects of the invasive, exotic hemlock woolly adelgid (HWA) in a headwater catchment in the southern Appalachian Mountains. The study watershed experienced complete mortality of an evergreen tree species, Tsuga canadensis (L.) Carr. (...

Development of Sirococcus shoot blight following thinning in western hemlock regeneration.

Science.gov (United States)

Charles G. Shaw; Thomas H. Laurent; Spencer. Israelson

1981-01-01

Shoot mortality from Sirococcus strobilinus Preuss. and other causes was recorded by crown position from April 1978 through October 1979 in younggrowth western hemlock (Tsuga heterophylla (Raf.) Sarg.) crop trees released in a 1977 thinning at Thomas Bay, Alaska. All study trees contained some infected shoots, but no terminal...

Multi-decadal establishment for single-cohort Douglas-fir forests

Science.gov (United States)

James A. Freund; Jerry F. Franklin; Andrew J. Larson; James A. Lutz

2014-01-01

The rate at which trees regenerate following stand-replacing wildfire is an important but poorly understood process in the multi-century development of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) forests. Temporal patterns of Douglas-fir establishment reconstructed from old-growth forests (>450 year) have...

Height development of shade-tolerant conifer saplings in multiaged Acadian forest stands

Science.gov (United States)

Andrew R. Moores; Robert S. Seymour; Laura S. Kenefic

2007-01-01

Understory growth dynamics of northern conifer species were studied in four stands managed under multiaged silvicultural systems in eastern Maine. Height growth of Picea rubens Sarg., Abies balsamea (L.) Mill., and Tsuga canadensis (L.) Carr. saplings between 0.5 and 6.0 m in height was related to the proportion...

Use of satellite image data to identify changes in hemlock health over space and time

Science.gov (United States)

Laurent R. Bonneau; Kathleen S. Shields; Daniel L. Civco; David R. Mikus

2000-01-01

Eastern hemlock (Tsuga canadensis (L.) Carriere), is an important component of ecosystems in the northeastern United States and is the primary coniferous species in southern Connecticut. Hemlocks play a unique role in the region by providing spatial and structural habitat diversity that supports many wildlife and fish populations. Widespread damage...

Eastern hemlock response to even- and uneven-age management in the Acadian forest: results from the Penobscot Experimental Forest long-term silviculture study

Science.gov (United States)

John C. Brissette; Laura S. Kenefic

2000-01-01

Eastern hemlock (Tsuga canadensis (L.) Carr.) is an important tree species in the mixed-species conifer forests of northern New England and adjacent Canada. Hemlock is very tolerant of understory conditions; consequently, it responds differently to various silvicultural treatments. In a long-term study at the Penobscot Experimental Forest in east-...

Cherry Creek Research Natural Area: guidebook supplement 41

Science.gov (United States)

Reid Schuller; Jennie Sperling; Tim Rodenkirk

2011-01-01

This guidebook describes Cherry Creek Research Natural Area, a 239-ha (590-ac) area that supports old-growth Douglas-fir-western hemlock (Pseudotsuga menziesii- Tsuga heterophylla) forest occurring on sedimentary materials in the southern Oregon Coast Range. Major plant associations present within the area include the western hemlock/Oregon oxalis...

Landscape- vs gap-level controls on the abundance of a fire-sensitive, late-successional tree species.

Science.gov (United States)

Michael C. Wimberly; Thomas A. Spies

2002-01-01

Tsuga heterophylla (western hemlock), a fire-sensitive, late-successional tree species, is an important component of old-growth forests in the Pacific Northwest, USA. In the Oregon Coast Range, however, T. heterophylla occurs at low densities in or is completely absent from many conifer stands. We used a cellular automata-based...

Behavioral responses of Laricobius spp.and hybrids (Coleoptera: Derodontidae) to hemlock woolly adelgid and adelgid host tree odors in an olfactometer

Science.gov (United States)

Arielle L. Arsenault; Nathan P. Havill; Albert E. Mayfield; Kimberly F. Wallin

2015-01-01

The predatory species Laricobius nigrinus (Fender) and Laricobius osakensis (Shiyake and Montgomery) (Coleoptera: Derodontidae) have been released for biological control of hemlock woolly adelgid (Adelges tsugae; Hemiptera: Adelgidae) in eastern North America. L. osakensis is native to Japan, whereas L. nigrinus is endemic to the Pacific Northwest of the United States...

Initial survey of predacious diptera on hemlocks in Japan

Science.gov (United States)

Hisashi Ohishi; Shigehiko Shiyake; Yorio Miyatake; Ashley Lamb; Michael E. Montgomery

2011-01-01

Some species of Coleoptera and Diptera are specialist predators of adelgids. Previously, we reported our survey of predacious Coleoptera on hemlocks in Japan (Shiyake et al. 2008). Two of these beetles, Sasajiscymnus tsugae and Laricobius sp. nov., have been exported to the U.S. for biological control. Here, we provide the first...

Invasions by two non-native insects alter regional forest species composition and successional trajectories

Science.gov (United States)

Randall S. Morin; Andrew M. Liebhold

2015-01-01

While invasions of individual non-native phytophagous insect species are known to affect growth and mortality of host trees, little is known about how multiple invasions combine to alter forest dynamics over large regions. In this study we integrate geographical data describing historical invasion spread of the hemlock woolly adelgid, Adelges tsugae...

Comparison of fecundity and survival of hemlock woolly adelgid (Hemiptera: Adelgidae) in northern and southern populations

Science.gov (United States)

Artemis Roehrig; Joseph. Elkinton

2011-01-01

The hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae), is an introduced species first reported in the eastern United States in 1951. The infestation has since spread in all directions from its initial sighting in Virginia, to its current range from northern Georgia, to southern Maine, and westward into Tennessee, causing...

Impact of Imidacloprid for control of Hemlock Woolly Adelgid on nearby aquatic macroinvertebrate asseblages.

Science.gov (United States)

Melissa Churchel; James Hanula; C. Wayne Berisford; James Vose; Mark Dalusky

2011-01-01

Imidacloprid, a systemic insecticide that acts on the nervous system, is currently being used to control hemlock woolly adelgid (Adelges tsugae Annand), which is damaging hemlock trees. The objective of this study was to determine whether soil injection with imidacloprid for hemlock woolly adelgid control near streams adversely affects aquatic invertebrates. Eastern...

Restoring pine barrens for avian conservation

Science.gov (United States)

Greg Corace

2001-01-01

At first glance, many visitors to Michigan's Upper Peninsula (U.P.) see a fairly uniform forested region. Although northern hardwood forests comprised of sugar maple (Acer saccharum), American basswood (Tilia americana), yellow birch (Betula alleghaniensis) and eastern hemlock (Tsuga canadensis) predominate, the U.P. is a fact a mosaic of forest cover types...

Classification and spatial analysis of eastern hemlock health using remote sensing and GIS

Science.gov (United States)

Laurent R. Bonneau; Kathleen S. Shields; Daniel L. Civco; David R. Mikus

2000-01-01

Over the past decade hemlock stands in southern Connecticut have undergone significant decline coincident with the arrival in 1985 of an exotic insect pest, the hemlock woolly adelgid (Adelges tsugae Annand). The objective of this study was to evaluate image enhancement techniques for rating the health of hemlocks at the landscape level using...

Understanding Federal regulations as guidelines for classical biological control programs

Science.gov (United States)

Michael E. Montgomery

2011-01-01

This chapter reviews the legislation and rules that provide the foundation for federal regulation of the introduction of natural enemies of insects as biological control agents. It also outlines the steps for complying with regulatory requirements, using biological control of Adelges tsugae Annand, the hemlock woolly adelgid (HWA), as an example. The...

Pennsylvania boreal conifer forests and their bird communities: past, present, and potential

Science.gov (United States)

Douglas A. Gross

2010-01-01

Pennsylvania spruce (Picea spp.)- and eastern hemlock (Tsuga canadensis)-dominated forests, found primarily on glaciated parts of the Allegheny Plateau, are relicts of boreal forest that covered the region following glacial retreat. The timber era of the late 1800s and early 1900s (as late as 1942) destroyed most of the boreal...

Bedrock type significantly affects individual tree mortality for various conifers in the inland Northwest, U.S.A

Science.gov (United States)

James A. Moore; David A Hamilton; Yu Xiao; John Byrne

2004-01-01

Individual tree mortality models for western white pine (Pinus monticola Dougl. ex D. Don), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), grand fir (Abies grandis (Dougl. ex D. Don) Lindl.), western redcedar (Thuja plicata Donn ex. D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western larch (Larix occidentalis Nutt.) were developed using data...

Hemlock woolly adelgid and its natural enemies in Sichuan Province, China, 2005

Science.gov (United States)

Jianhua Zhou; Yinbo Xiao; Yugui Xiao; Wenhua Lu; Michael Montgomery; Roy Van Driesche; Scott Salom

2007-01-01

A partnership of Chinese and American institutions was formed in 2005 to obtain natural enemies for biological control of Adelges tsugae Annand, the hemlock woolly adelgid (HWA), in the eastern United States. We report here the first 6 months (June-November) of studies done at three sites in Kangding and Baoxing Counties in Sichuan Province.

Vegetation Sampling for Wetland Delineation: A Review and Synthesis of Methods and Sampling Issues

Science.gov (United States)

2010-07-01

which trees are sampled via use of an angle gauge or basal area prism (Husch et al. 2003; Packard and Radtke 2007). Basal area data can be used to...refuges from fungal pathogens for seeds of eastern hemlock (Tsuga canadensis). Ecology 85(1): 284– 289. Packard, K. C., and P. J. Radtke . 2007. Forest

Flavanol binding of nuclei from tree species.

Science.gov (United States)

Feucht, W; Treutter, D; Polster, J

2004-01-01

Light microscopy was used to examine the nuclei of five tree species with respect to the presence of flavanols. Flavanols develop a blue colouration in the presence of a special p-dimethylaminocinnamaldehyde (DMACA) reagent that enables those nuclei loaded with flavanols to be recognized. Staining of the nuclei was most pronounced in both Tsuga canadensis and Taxus baccata, variable in Metasequoia glyptostroboides, faint in Coffea arabica and minimal in Prunus avium. HPLC analysis showed that the five species contained substantial amounts of different flavanols such as catechin, epicatechin and proanthocyanidins. Quantitatively, total flavanols were quite different among the species. The nuclei themselves, as studied in Tsuga seed wings, were found to contain mainly catechin, much lower amounts of epicatechin and traces of proanthocyanidins. Blue-coloured nuclei located centrally in small cells were often found to maximally occupy up to 90% of a cell's radius, and the surrounding small rim of cytoplasm was visibly free of flavanols. A survey of 34 gymnosperm and angiosperm species indicated that the first group has much higher nuclear binding capacities for flavanols than the second group.

Influence of Hemlock Woolly Adelgid Infestation Levels on Water Stress in Eastern Hemlocks within the Great Smoky Mountains National Park, U.S.A.

Directory of Open Access Journals (Sweden)

Carla Coots

2015-01-01

Full Text Available Extensive mortality of eastern hemlock, Tsuga canadensis (L. Carrière, resulting from infestation by hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae, has occurred throughout the eastern United States. Although imidacloprid treatment can reduce tree mortality, its effectiveness can be influenced by several factors including tree water stress. The relationship between water stress and infestation rates is unknown, and an understanding of these could greatly increase the efficiency of management for this invasive insect. The primary objective of this study was to assess water stress at three levels of hemlock woolly adelgid infestations. Water stress was measured monthly for 13 months in eastern hemlocks classified as <25%, 25%–75%, and >75% infested. The highest level of water stress was found in those trees with hemlock woolly adelgid infestation levels greater than 75%. The lowest level of water stress was found in those trees with less than 25% hemlock woolly adelgid infestation levels. Knowledge of these effects can contribute to development of more effective chemical management strategies.

Hemlock resources at risk in the Great Smoky Mountains National Park

Science.gov (United States)

Kristine D. Johnson; Fred P. Hain; Katherine S. Johnson; Felton Hastings

2000-01-01

Eastern hemlock (Tsuga canadensis (L.) Carr) is the dominant species in a variety of sites in Great Smoky Mountains National Park. Hemlock covers approximately 3820 acres (1528 hectares) or one percent of the Park, which at 524,856 acres is the largest area managed as wilderness in the eastern United States. Since timber was never harvested in about...

Dynamics of Connecticut hemlock stands

Science.gov (United States)

Jeffrey S. Ward; David M. Smith

2000-01-01

The stand dynamics and production of two one-acre plots of eastern hemlock (Tsuga canadensis L) in Connecticut have been followed for more than six decades. Data were recorded for all individual trees. One plot (Saltonstall) was established in 1924 after the removal of a hardwood overstory. This stand had a nearly pure, almost fully closed understory...

Horse Rock Ridge Research Natural Area: guidebook supplement 27.

Science.gov (United States)

Alan B. Curtis

2003-01-01

Horse Rock Ridge Research Natural Area (HRR RNA) was established in June 1995 to protect the best remaining example of a grassy “bald” (treeless area) on the western margin of the Cascade Range and its associated botanical, wildlife, and scenic values. This bald is surrounded by old-growth Pseudotsuga menziesii/Tsuga heterophylla...

Impacts of hemlock decline and ecological considerations for hemlock stand restoration following hemlock woolly adelgid outbreaks

Science.gov (United States)

Sarah Z. Jonas; Weimin Xi; John D. Waldron; Robert N. Coulson

2012-01-01

We present a synthesis of current knowledge and information of hemlock woolly adelgid (HWA, Adelges tsugae Annand) impact on hemlock forests and conceptual framework of restoring damaged hemlock stands by HWA infestation. Native to Asia, HWA has been thriving in the eastern United States since the early 1950s and has become a serious pathological agent of both eastern...

Development of epicormic sprouts in Sitka spruce following thinning and pruning in south-east Alaska.

Science.gov (United States)

Robert L. Deal; R. James Barbour; Michael H. McClellan; Dean L. Parry

2003-01-01

The frequency and size of epicormic sprouts in Sitka spruce (Picea sitchensis (Bong.) Carr.) were assessed in five 23-29 year-old mixed Sitka spruce-western hemlock (Tsuga heterophylla (Raf.) Sarg.) stands that were uniformly thinned and pruned to 2.4, 3.7 and 5.2 m lift heights. Six to nine years after treatment sprouts were...

Chinese Coccinellidae for biological control of the hemlock woolly adelgid: description of native habitat

Science.gov (United States)

Michael E. Montgomery; Defu Yao; Hongbin Wang

2000-01-01

The hemlock woolly adelgid, Adelges tsugae Annand, is generally believed to be native to Asia and is known to occur in India, Japan, and China. In China, there are approximately four species of hemlock that grow in 14 provinces. We explored regions of the Southwestern Plateau in Yunnan, Sichuan, and Shaanxi Provinces for the adelgid and its natural...

Enhancement of foreign collection and quarantine evaluation of hemlock woolly adelgid natural enemies

Science.gov (United States)

Mike Montgomery; Roy Van Driesche; Scott Salom; Wenhua Lu; Guoyue Yu; Jianhua Zhou; Li Li; Shigehiko Shiyake

2007-01-01

The objectives of this newly funded Forest Service activity are to promote the biological control of hemlock woolly adelgid (Adelges tsugae Annand) by (1) hiring an entomologist to work in Asia; (2) revisit known collecting sites and find promising new ones; (3) study the life history and phenology of HWA and its predators; (4) establish protocols...

Induction of cold hardiness in an invasive herbivore: The case of hemlock woolly adelgid (Hemiptera: Adelgidae)

Science.gov (United States)

Joseph S. Elkinton; Jeffrey A. Lombardo; Artemis D. Roehrig; Thomas J. McAvoy; Albert Mayfield; Mark Whitmore

2017-01-01

As a measure of cold hardiness, we tested the supercooling points or freezing temperatures of individual hemlock woolly adelgids (Adelges tsugae Annand) collected from 15 locations across the north to south range of the adelgid in eastern North America at different times during two winters. Adelgids from the northern interior locations with USDA hardiness zones of 5B–...

Multivariate statistical analysis of hemlock (Tsuga) volatiles by SPME/GC/MS: insights into the phytochemistry of the hemlock woolly adelgid (Adelges tsugae Annand)

Science.gov (United States)

Anthony Lagalante; Frank Calvosa; Michael Mirzabeigi; Vikram Iyengar; Michael Montgomery; Kathleen Shields

2007-01-01

A previously developed single-needle, SPME/GC/MS technique was used to measure the terpenoid content of T. canadensis growing in a hemlock forest at Lake Scranton, PA (Lagalante and Montgomery 2003). The volatile terpenoid composition was measured over a 1-year period from June 2003 to May 2004 to follow the annual cycle of foliage development from...

Postglacial vegetation history of Mitkof Island, Alexander Archipelago, southeastern Alaska

Science.gov (United States)

Ager, Thomas A.; Carrara, Paul E.; Smith, Jane L.; Anne, Victoria; Johnson, Joni

2010-03-01

An AMS radiocarbon-dated pollen record from a peat deposit on Mitkof Island, southeastern Alaska provides a vegetation history spanning ˜12,900 cal yr BP to the present. Late Wisconsin glaciers covered the entire island; deglaciation occurred > 15,400 cal yr BP. The earliest known vegetation to develop on the island (˜12,900 cal yr BP) was pine woodland ( Pinus contorta) with alder ( Alnus), sedges (Cyperaceae) and ferns (Polypodiaceae type). By ˜12,240 cal yr BP, Sitka spruce ( Picea sitchensis) began to colonize the island while pine woodland declined. By ˜11,200 cal yr BP, mountain hemlock ( Tsuga mertensiana) began to spread across the island. Sitka spruce-mountain hemlock forests dominated the lowland landscapes of the island until ˜10,180 cal yr BP, when western hemlock ( Tsuga heterophylla) began to colonize, and soon became the dominant tree species. Rising percentages of pine, sedge, and sphagnum after ˜7100 cal yr BP may reflect an expansion of peat bog habitats as regional climate began to shift to cooler, wetter conditions. A decline in alders at that time suggests that coastal forests had spread into the island's uplands, replacing large areas of alder thickets. Cedars ( Chamaecyparis nootkatensis, Thuja plicata) appeared on Mitkof Island during the late Holocene.

Interim Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region

Science.gov (United States)

2008-04-01

elevations in the local area dominated by conifers (e.g., spruce (Picea), fir (Abies), hemlock (Tsuga), Douglas-fir (Pseudotsuga), coast redwood...annual temperature is 33 to 62 ºF (1 to 17 ºC) (USDA Natural Resources Conservation Service 2006a). Low-elevation mixed conifer forests are...redox concentrations and those that do not, for hue 10YR, to meet the definition of a depleted matrix. Due to inaccurate color reproduction , do not use

Late-glacial and Holocene Vegetation and Climate Variability, Including Major Droughts, in the Sky Lakes Region of Southeastern New York State

Science.gov (United States)

Menking, Kirsten M.; Peteet, Dorothy M.; Anderson, Roger Y.

2012-01-01

Sediment cores from Lakes Minnewaska and Mohonk in the Shawangunk Mountains of southeastern New York were analyzed for pollen, plantmacrofossils, macroscopic charcoal, organic carbon content, carbon isotopic composition, carbon/nitrogen ratio, and lithologic changes to determine the vegetation and landscape history of the greater Catskill Mountain region since deglaciation. Pollen stratigraphy generally matches the New England pollen zones identified by Deevey (1939) and Davis (1969), with boreal genera (Picea, Abies) present during the late Pleistocene yielding to a mixed Pinus, Quercus and Tsuga forest in the early Holocene. Lake Minnewaska sediments record the Younger Dryas and possibly the 8.2 cal kyr BP climatic events in pollen and sediment chemistry along with an 1400 cal yr interval of wet conditions (increasing Tsuga and declining Quercus) centered about 6400 cal yr BP. BothMinnewaska andMohonk reveal a protracted drought interval in themiddle Holocene, 5700-4100 cal yr BP, during which Pinus rigida colonized the watershed, lake levels fell, and frequent fires led to enhanced hillslope erosion. Together, the records show at least three wet-dry cycles throughout the Holocene and both similarities and differences to climate records in New England and central New York. Drought intervals raise concerns for water resources in the New York City metropolitan area and may reflect a combination of enhanced La Niña, negative phase NAO, and positive phase PNA climatic patterns and/or northward shifts of storm tracks.

The potential to characterize ecological data with terrestrial laser scanning in Harvard Forest, MA

Science.gov (United States)

Boucher, P.; Saenz, E.; Li, Z.

2018-01-01

Contemporary terrestrial laser scanning (TLS) is being used widely in forest ecology applications to examine ecosystem properties at increasing spatial and temporal scales. Harvard Forest (HF) in Petersham, MA, USA, is a long-term ecological research (LTER) site, a National Ecological Observatory Network (NEON) location and contains a 35 ha plot which is part of Smithsonian Institution's Forest Global Earth Observatory (ForestGEO). The combination of long-term field plots, eddy flux towers and the detailed past historical records has made HF very appealing for a variety of remote sensing studies. Terrestrial laser scanners, including three pioneering research instruments: the Echidna Validation Instrument, the Dual-Wavelength Echidna Lidar and the Compact Biomass Lidar, have already been used both independently and in conjunction with airborne laser scanning data and forest census data to characterize forest dynamics. TLS approaches include three-dimensional reconstructions of a plot over time, establishing the impact of ice storm damage on forest canopy structure, and characterizing eastern hemlock (Tsuga canadensis) canopy health affected by an invasive insect, the hemlock woolly adelgid (Adelges tsugae). Efforts such as those deployed at HF are demonstrating the power of TLS as a tool for monitoring ecological dynamics, identifying emerging forest health issues, measuring forest biomass and capturing ecological data relevant to other disciplines. This paper highlights various aspects of the ForestGEO plot that are important to current TLS work, the potential for exchange between forest ecology and TLS, and emphasizes the strength of combining TLS data with long-term ecological field data to create emerging opportunities for scientific study. PMID:29503723

The potential to characterize ecological data with terrestrial laser scanning in Harvard Forest, MA.

Science.gov (United States)

Orwig, D A; Boucher, P; Paynter, I; Saenz, E; Li, Z; Schaaf, C

2018-04-06

Contemporary terrestrial laser scanning (TLS) is being used widely in forest ecology applications to examine ecosystem properties at increasing spatial and temporal scales. Harvard Forest (HF) in Petersham, MA, USA, is a long-term ecological research (LTER) site, a National Ecological Observatory Network (NEON) location and contains a 35 ha plot which is part of Smithsonian Institution's Forest Global Earth Observatory (ForestGEO). The combination of long-term field plots, eddy flux towers and the detailed past historical records has made HF very appealing for a variety of remote sensing studies. Terrestrial laser scanners, including three pioneering research instruments: the Echidna Validation Instrument, the Dual-Wavelength Echidna Lidar and the Compact Biomass Lidar, have already been used both independently and in conjunction with airborne laser scanning data and forest census data to characterize forest dynamics. TLS approaches include three-dimensional reconstructions of a plot over time, establishing the impact of ice storm damage on forest canopy structure, and characterizing eastern hemlock ( Tsuga canadensis ) canopy health affected by an invasive insect, the hemlock woolly adelgid ( Adelges tsugae ). Efforts such as those deployed at HF are demonstrating the power of TLS as a tool for monitoring ecological dynamics, identifying emerging forest health issues, measuring forest biomass and capturing ecological data relevant to other disciplines. This paper highlights various aspects of the ForestGEO plot that are important to current TLS work, the potential for exchange between forest ecology and TLS, and emphasizes the strength of combining TLS data with long-term ecological field data to create emerging opportunities for scientific study.

Influence of Imidacloprid and Horticultural Oil on Spider Abundance on Eastern Hemlock in the Southern Appalachians.

Science.gov (United States)

Hakeem, A; Grant, J F; Lambdin, P L; Hale, F A; Rhea, J R; Wiggins, G J; Coots, C

2018-05-08

Hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is an exotic pest of eastern hemlock, Tsuga canadensis (L.) Carrière (Pinales: Pinaceae), in the eastern United States. Two commonly used insecticides to manage adelgid are imidacloprid, a systemic neonicotinoid insecticide, and horticultural oil, a refined petroleum oil foliar spray. We have investigated the influence of imidacloprid and horticultural oil on spider abundance at different canopy strata in eastern hemlock. In total, 2,084 spiders representing 11 families were collected from the canopies of eastern hemlock. In beat-sheet and direct observation samples, the families Theridiidae, Araneidae, Salticidae, and Anyphaenidae were the most abundant. Significantly higher numbers of spiders were recorded on untreated control trees compared with trees treated with imidacloprid using soil drench and soil injection applications. Spider abundance in trees injected with imidacloprid and horticultural oil applications did not significantly differ from control trees. Spider abundance was significantly greater in the top and middle strata of the canopy than in the bottom stratum, where imidacloprid concentrations were the highest. Regression analysis showed that spider abundance was inversely associated with imidacloprid concentration. This research demonstrates that imidacloprid, when applied with selected methods, has the potential to result in reductions of spider densities at different strata. However, slight reductions in spider abundance may be an acceptable short-term ecological impact compared with the loss of an untreated hemlock and all the associated ecological benefits that it provides. Future studies should include investigations of long-term impact of imidacloprid on spiders associated with eastern hemlock.

Nuclear geophysics in prospecting for ore and coal deposits; Geophysique nucleaire et prospection des gisements de charbon et autres mineraux; Yadernaya geofizika pri razvedke rudnykh i ugol'nykh mestorozhdenij; Geofisica nuclear u prospeccion de yacimientos de carbon y otros minerales

Energy Technology Data Exchange (ETDEWEB)

Bulashevich, Yu P; Voskobojnikov, G M; Muzyukin, L V

1962-01-15

captura de neutrones termicos del boro hace posible determinar estratos boriferos en la zona del sondeo empleando los metodos E.G.N. y E.N.N. La influencia del agua se elimina mediante sondeos inversos. Este metodo, asi como otros sistemas de exploracion por activacion neutronica, han sido aplicados tambien en diversos yacimientos de cobre, manganeso, aluminio y otros minerales. La exploracion por activacion continua esta indicada cuando el periodo de semi [Russian] Na rudnykh i ugol'nykh mestorozhdeniyakh metody yadernoj geofiziki primenyayutsya glavnym obrazom pri karotazhe razvedochnykh skvazhin. Na rudnykh i ugol'nykh mestorozhdeniyakh Sovetskogo Soyuza nakhodyat shirokoe proizvodstvennoe primenenie sleduyushchie vidy radioaktivnogo ili yadernogo karotazha (RK): plotnostnoj ili gamma-gamma karotazh (GGK) s istochnikom izlucheniya Co{sup 60}, selektivnyj gamma-gamma karotazh (SGGK) s istochnikom myagkogo izlucheniya tipa S75, nejtron-nejtronnyj karotazh (NNK) i nejtronnyj gamma karotazh s Ro-Ve istochnikom nejtronov, akti- vatsionnyj, v chastnosti nepreryvnyj, karotazh s tem zhe istochnikom, a takzhe foto-nej- tronnyj karotazh s gamma-izluchatelem Sb{sup 124}. Osnovnaya zadacha RK na rudnykh mestorozhdeniyakh - vydelenie rudnykh zon v razreze skvazhin, chto sokrashchaet intervaly oprobovaniya, i orientirovochnaya otsenka soderzhaniya poleznogo komponenta in situ. Na ugol'nykh mestorozhdeniyakh RK reshaet zadachu opredeleniya glubiny zaleganiya, moshchnosti i stroeniya ugol'nykh plastov. ' Metody GGK i SGGK osnovany na registratsii rasseyannogo gamma-izlucheniya istochnika. Pri dostatochnoj zhestkosti izlucheniya istochnika i slaboj chuvstvitel'nosti indikatora intensivnost' rasseyannogo izlucheniya zavisit tol'ko ot plotnosti porody i rasstoyaniya mezhdu istochnikom i indikatorom. EHto sluchaj GGK, kotorym ugol'nye plasty vydelyayutsya po maksimumam rasseyannogo izlucheniya. V SGGK sushchestvenna registratsiya myagkoj chasti spektra rasseyannogo izlucheniya

Study on pulsed radiation generation in the accelerator AKVAGEN; Issledovanie po generatsii impul`sa izlucheniya uskoritelya AKVAGEN

Energy Technology Data Exchange (ETDEWEB)

Bakulin, Yu P [and others

1994-12-31

The pulse accelerator AKVAGEN is created according to a circuit of as single forming line, charged from two pulse transformers up to 1.5 voltage. Typical irradiation levels are presented. The accelerator x radiation efficiency calculated makes up for Si and SiC, SiO{sub 2}, GaAs compounds.

Acceleration of exotic plant invasion in a forested ecosystem by a generalist herbivore.

Science.gov (United States)

Eschtruth, Anne K; Battles, John J

2009-04-01

The successful invasion of exotic plants is often attributed to the absence of coevolved enemies in the introduced range (i.e., the enemy release hypothesis). Nevertheless, several components of this hypothesis, including the role of generalist herbivores, remain relatively unexplored. We used repeated censuses of exclosures and paired controls to investigate the role of a generalist herbivore, white-tailed deer (Odocoileus virginianus), in the invasion of 3 exotic plant species (Microstegium vimineum, Alliaria petiolata, and Berberis thunbergii) in eastern hemlock (Tsuga canadensis) forests in New Jersey and Pennsylvania (U.S.A.). This work was conducted in 10 eastern hemlock (T. canadensis) forests that spanned gradients in deer density and in the severity of canopy disturbance caused by an introduced insect pest, the hemlock woolly adelgid (Adelges tsugae). We used maximum likelihood estimation and information theoretics to quantify the strength of evidence for alternative models of the influence of deer density and its interaction with the severity of canopy disturbance on exotic plant abundance. Our results were consistent with the enemy release hypothesis in that exotic plants gained a competitive advantage in the presence of generalist herbivores in the introduced range. The abundance of all 3 exotic plants increased significantly more in the control plots than in the paired exclosures. For all species, the inclusion of canopy disturbance parameters resulted in models with substantially greater support than the deer density only models. Our results suggest that white-tailed deer herbivory can accelerate the invasion of exotic plants and that canopy disturbance can interact with herbivory to magnify the impact. In addition, our results provide compelling evidence of nonlinear relationships between deer density and the impact of herbivory on exotic species abundance. These findings highlight the important role of herbivore density in determining impacts on

Invasive insect effects on nitrogen cycling and host physiology are not tightly linked.

Science.gov (United States)

Rubino, Lucy; Charles, Sherley; Sirulnik, Abby G; Tuininga, Amy R; Lewis, James D

2015-02-01

Invasive insects may dramatically alter resource cycling and productivity in forest ecosystems. Yet, although responses of individual trees should both reflect and affect ecosystem-scale responses, relationships between physiological- and ecosystem-scale responses to invasive insects have not been extensively studied. To address this issue, we examined changes in soil nitrogen (N) cycling, N uptake and allocation, and needle biochemistry and physiology in eastern hemlock (Tsuga canadensis (L) Carr) saplings, associated with infestation by the hemlock woolly adelgid (HWA) (Adelges tsugae Annand), an invasive insect causing widespread decline of eastern hemlock in the eastern USA. Compared with uninfested saplings, infested saplings had soils that exhibited faster nitrification rates, and more needle (15)N uptake, N and total protein concentrations. However, these variables did not clearly covary. Further, within infested saplings, needle N concentration did not vary with HWA density. Light-saturated net photosynthetic rates (Asat) declined by 42% as HWA density increased from 0 to 3 adelgids per needle, but did not vary with needle N concentration. Rather, Asat varied with stomatal conductance, which was highest at the lowest HWA density and accounted for 79% of the variation in Asat. Photosynthetic light response did not differ among HWA densities. Our results suggest that the effects of HWA infestation on soil N pools and fluxes, (15)N uptake, needle N and protein concentrations, and needle physiology may not be tightly coupled under at least some conditions. This pattern may reflect direct effects of the HWA on N uptake by host trees, as well as effects of other scale-dependent factors, such as tree hydrology, affected by HWA activity. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Experimental Evidence that Hemlock Mortality Enhances Carbon Stabilization in Southern Appalachian Forest Soils

Science.gov (United States)

Fraterrigo, J.; Ream, K.; Knoepp, J.

2017-12-01

Forest insects and pathogens (FIPs) can cause uncertain changes in forest carbon balance, potentially influencing global atmospheric carbon dioxide (CO2) concentrations. We quantified the effects of hemlock (Tsuga canadensis L. Carr.) mortality on soil carbon fluxes and pools for a decade following either girdling or natural infestation by hemlock woolly adelgid (HWA; Adelges tsugae) to improve mechanistic understanding of soil carbon cycling response to FIPs. Although soil respiration (Rsoil) was similar among reference plots and plots with hemlock mortality, both girdled and HWA-infested plots had greater activities of β-glucosidase, a cellulose-hydrolyzing extracellular enzyme, and decreased O-horizon mass and fine root biomass from 2005 to 2013. During this period, total mineral soil carbon accumulated at a higher rate in disturbed plots than in reference plots in both the surface (0-10 cm) and subsurface (10-30 cm); increases were predominantly in the mineral-associated fraction of the soil organic matter. In contrast, particulate organic matter carbon accrued slowly in surface soils and declined in the subsurface of girdled plots. δ13C values of this fraction demonstrate that particulate organic matter carbon in the surface soil has become more microbially processed over time, suggesting enhanced decomposition of organic matter in this pool. Together, these findings indicate that hemlock mortality and subsequent forest regrowth has led to enhanced soil carbon stabilization in southern Appalachian forests through the translocation of carbon from detritus and particulate soil organic matter pools to the mineral-associated organic matter pool. These findings have implications for ecosystem management and modeling, demonstrating that forests may tolerate moderate disturbance without diminishing soil carbon storage when there is a compensatory growth response by non-host trees.

Early pleistocene sediments at Great Blakenham, Suffolk, England

Science.gov (United States)

Gibbard, P. L.; Allen, P.; Field, M. H.; Hallam, D. F.

Detailed investigation of a fine sediment sequence, the College Farm Silty Clay Member, that overlies the Creeting Sands (Early Pleistocene) in Suffolk, is presented. The sedimentary sequence is thought to represent a freshwater pool accumulation in a small coastal embayment. Palaeobotanical investigation of the sediment indicates that it accumulated during the late temperate substage of a temperate (interglacial) event. The occurrence of Tsuga pollen, associated with abundant remains of the water fern Azolla tegeliensis indicate that the deposits are of Early Pleistocene age and are correlated with a later part of the Antian-Bramertonian Stage. Correlation with Tiglian TO substage in The Netherlands' sequence is most likely. The sediments' normal palaeomagnetic polarity reinforces the biostratigraphical correlation.

Manufacture of Wood-Plastic Combinations by Use of Gamma Radiation; Fabrication de combinaisons bois-matiere plastique a l'aide des rayons gamma; Proizvodstvo drevesno-plastmassovykh sostavov s pomoshch'yu gamma-izlucheniya; Impregnacion de maderas con materiales plasticos en presencia de radiaciones gamma

Energy Technology Data Exchange (ETDEWEB)

Kent, J. A.; Winston, A.; Boyle, W.; Updyke, L. [Engineering Experiment Station, West Virginia University, Morgantown, West Virginia (United States)

1963-11-15

maderas de pino albar, encina blanca, encina roja, alamo, abedul, haya, abeto y arce sacarino. Se indica el efecto de la intensidad de dosis sobre las velocidades de polimerizacion en esas combinaciones, algunas de las cuales son incompatibles. Por ejemplo, la secoya no permite la polimerizacion del acetato de vinilo o del metacrilato de metilo, en tanto que el pino albar imposibilita la polimerizacion del acetato de vinilo. Los autores estudiaron diversos agentes de reticulacion con miras a determinar su eficacia para acelerar la polimerizacion y, con ello, conseguir ciclos mas breves, y exponen los resultados obtenidos para el acrilato de alilo, el dimetacrilato de etilenglicol, el dimetacrilato de polietilenglicol, el titanato de tetra-isopropilo, el metacrilato de alilo y (en el caso del estireno) el divinilbenceno. Los ensayos mecanicos realizados con maderas impregnadas ponen de manifiesto una mejora de propiedades tales como la dureza, el limite de elasticidad en la compresion y la estabilidad dimensional. Por lo general, se registra un aurpento de la fragilidad respecto de la madera natural. En la memoria se incluyen datos sobre la dureza, el limite de elasticidad en la compresion, la estabilidad en la compresion, la estabilidad dimensional, asi como la resistencia a la flexion y al cizallamiento. (author) [Russian] Opisan promyshlennyj metod polucheniya drevesno-plastmassovykh ''splavov'' s pomoshch'yu gamma-izlucheniya. Protsess sostoit iz dvukh chastej: propitki otobrannoj drevesiny neobkhodimym monomerom i polimerizatsii monomera v meste nakhozhdeniya .s pomoshch'yu gamma-luchej. Izucheno vliyanie razlichnykh faktorov na proniknovenie monomera v drevesinu. Provedennye ispytaniya pokazali, chto na praktike osushchestvimo khoroshee raspredelenie polimera v konechnom produkte. Odnu chast' obraztsov tolshchinoj 10 cm i dlinoj 150 cm podvergli propitke i issledovali na pronikanie monomera, v to vremya kak druguyu chast' obraztsov takoj zhe tolshchiny uspeshno

Late Glacial-Holocene Pollen-Based Vegetation History from Pass Lake, Prince of Wales Island, Southeastern Alaska

Science.gov (United States)

Ager, Thomas A.; Rosenbaum, Joseph G.

2009-01-01

A radiocarbon-dated history of vegetation development since late Wisconsin deglaciation has been reconstructed from pollen evidence preserved in a sediment core from Pass Lake on Prince of Wales Island, southeastern Alaska. The shallow lake is in the south-central part of the island and occupies a low pass that was filled by glacial ice of local origin during the late Wisconsin glaciation. The oldest pollen assemblages indicate that pine woodland (Pinus contorta) had developed in the area by ~13,715 cal yr B.P. An abrupt decline in the pine population, coinciding with expansion of alder (Alnus) and ferns (mostly Polypodiaceae) began ~12,875 yr B.P., and may have been a response to colder, drier climates during the Younger Dryas climatic interval. Mountain hemlock (Tsuga mertensiana) began to colonize central Prince of Wales Island by ~11,920 yr B.P. and was soon followed by Sitka spruce (Picea sitchensis). Pollen of western hemlock (Tsuga heterophylla) began to appear in Pass Lake sediments soon after 11,200 yr B.P. The abundance of western hemlock pollen in the Pass Lake core during most of the Holocene appears to be the result of wind transport from trees growing at lower altitudes on the island. The late Holocene pollen record from Pass Lake is incomplete because of one or more unconformities, but the available record suggests that a vegetation change occurred during the late Holocene. Increases in pollen percentages of pine, cedar (probably yellow cedar, Chamaecyparis nootkatensis), and heaths (Ericales) suggest an expansion of muskeg vegetation occurred in the area during the late Holocene. This vegetation change may be related to the onset of cooler, wetter climates that began as early as ~3,774 yr B.P. in the region. This vegetation history provides the first radiocarbon-dated Late Glacial-Holocene terrestrial paleoecological framework for Prince of Wales Island. An analysis of magnetic properties of core sediments from Pass Lake suggests that unconformities

The greening of the Himalayas and Tibetan Plateau under climate change

Science.gov (United States)

Lamsal, Pramod; Kumar, Lalit; Shabani, Farzin; Atreya, Kishor

2017-12-01

The possible disruption of climate change (CC) on the ecological, economic and social segments of human interest has made this phenomenon a major issue over the last couple of decades. Mountains are fragile ecosystems, projected to endure a higher impact from the increased warming. This study presents modelled CC projections with respect to the suitability for the growth of nine near-treeline plant species of the Himalayas and Tibetan Plateau through niche modelling technique using CLIMEX and estimates their potential future distribution and the extent of greening in the region. Two global climate models, CSIRO-MK 3.0 (CS) and MIROCH-H (MR) were used under IPCC A1B and A2 emission scenarios for the year 2050 and 2100. The results indicate that climatic suitability of the nine species expands towards higher elevations into areas that are currently unsuitable while currently suitable areas in many regions become climatically unsuitable in the future. The total climatically suitable area for the nine species at current time is around 1.09 million km2, with an additional 0.68 and 0.35 million km2 becoming suitable by 2050 and 2100 respectively. High elevation belts, especially those lying above 3500 m, will see more climatically suitable areas for the nine species in the future. Cold stress is the main factor limiting current distribution and its decrease will affect the overall expansion of climatic suitability in the region. Impacts on nature conservation and water and food security could be expected from such shift of climatic suitability in the region. The species includes (i) Abies spectabilis, (ii) Acer campbellii, (iii) Betula utilis, (iv) Juniperus indica, (v) Quercus semecarpifolia, (vi) Tsuga dumosa, (vii) Rhododendron campanulatum, (viii) Ephedra gerardiana, and (ix) Cassiope fastigiata. The species list from top to bottom are (i) Abies spectabilis, (ii) Acer campbellii, (iii) Betula utilis, (iv) Juniperus indica, (v) Quercus semecarpifolia, (vi) Tsuga

Effects of potentially acidic air pollutants on the intracellular distribution and transport of plant growth regulators in mesophyll cells of leaves. Consequences on stress- and developmental physiology

Energy Technology Data Exchange (ETDEWEB)

Kremer, H.; Pfanz, H.; Hartung, W.

1987-07-11

The influence of SO/sub 2/ on the intracellular distribution of abscisic acid (ABA) and indole-acetic acid (IAA) in mesophyll cells of Picea abies, Tsuga americana and Hordeum vulgare was investigated. The compartmentation of ABA and IAA depends on intracellular pH-gradients. The hydrophilic anions ABA and IAA are accumulated in the alkaline cell compartments cytosol and chloroplasts, which act as anion traps for weak acids. Uptake of sulfur dioxide into leaves leads to an acidification of alkaline cell compartments, thus decreasing intracellular pH-gradients. Consequently this results in an increased release of plant growth regulators from the cell interior into the apoplast. Therefore the target cells of plant hormones i.e. meristems and stomates are exposed to altered hormone concentrations. Obviously this influences the regulation of cellular metabolism plant development and growth.

AMS radiocarbon dating of wood trunks in the pumiceous deposits of the Kikai-Akahoya eruption in Yakushima Island, SW Japan

Science.gov (United States)

Okuno, Mitsuru; Nakamura, Toshio; Geshi, Nobuo; Kimura, Katsuhiko; Saito-Kokubu, Yoko; Kobayashi, Tetsuo

2013-01-01

Radiocarbon dating using accelerator mass spectrometry (AMS) was performed on numerous wood trunks from pumiceous deposits along the Nagata, Isso and Miyanoura rivers on the northern side of Yakushima Island, 60 km south of Kyushu Island. The obtained 14C dates were around 6.5 ka BP, which, in combination with the geological characteristics of the pumiceous deposits indicates that these specimens were buried during the Kikai-Akahoya (K-Ah) eruption from the Kikai caldera. However, the fact that they are not charred suggests that the origin of these deposits are not pyroclastic flows. Fourteen taxa (Pinus subgen. Diploxylon, Tsuga, Cryptomeria, Chamaecyparis, Myrica, Castanea, Castanopsis, Quercus subgen. Cyclobalanopsis, Trochodendron, Phellodendron, Lagerstroemia, Rhododendron, Myrsine and Symplocos) were identified through anatomical characteristics. This is the first discovery of forest species on the Yakushima Island before the devastating eruption.

AMS radiocarbon dating of wood trunks in the pumiceous deposits of the Kikai-Akahoya eruption in Yakushima Island, SW Japan

Energy Technology Data Exchange (ETDEWEB)

Okuno, Mitsuru, E-mail: okuno@fukuoka-u.ac.jp [Department of Earth System Science, Faculty of Science, Fukuoka University, 814-0180 Fukuoka (Japan); AIG Collaborative Research Institute for International Study on Eruptive History and Informatics, Fukuoka University, 814-0180 Fukuoka (Japan); Nakamura, Toshio [Center for Chronological Research, Nagoya University, 464-8602 Nagoya (Japan); Geshi, Nobuo [Geological Survey of Japan, National Institute of Advanced Science and Technology, 305-8567 Tsukuba (Japan); Kimura, Katsuhiko [Division of Environment System Management, Faculty of Symbiotic System Science, Fukushima University, 960-1296 Fukushima (Japan); Saito-Kokubu, Yoko [Tono Geoscience Center, Japan Atomic Energy Agency (JAEA), 959-31 Jorinji, Toki, Gifu 509-5102 (Japan); Kobayashi, Tetsuo [Department of Earth and Environmental Sciences, Graduate School of Science and Engineering, Kagoshima University, 890-0065 Kagoshima (Japan)

2013-01-15

Radiocarbon dating using accelerator mass spectrometry (AMS) was performed on numerous wood trunks from pumiceous deposits along the Nagata, Isso and Miyanoura rivers on the northern side of Yakushima Island, 60 km south of Kyushu Island. The obtained {sup 14}C dates were around 6.5 ka BP, which, in combination with the geological characteristics of the pumiceous deposits indicates that these specimens were buried during the Kikai-Akahoya (K-Ah) eruption from the Kikai caldera. However, the fact that they are not charred suggests that the origin of these deposits are not pyroclastic flows. Fourteen taxa (Pinus subgen. Diploxylon, Tsuga, Cryptomeria, Chamaecyparis, Myrica, Castanea, Castanopsis, Quercus subgen. Cyclobalanopsis, Trochodendron, Phellodendron, Lagerstroemia, Rhododendron, Myrsine and Symplocos) were identified through anatomical characteristics. This is the first discovery of forest species on the Yakushima Island before the devastating eruption.

Theory of isotope scanning; Theorie de l'Exploration par les Radioisotopes; Teoriya meditsinskikh issledovanij s primeneniem izotopov; Teoria de la exploracion mediante radioisotopos

Energy Technology Data Exchange (ETDEWEB)

Brownell, G L [Physics Research Laboratory, Massachusetts General Hospital, Boston, MA (United States)

1959-07-01

aspecto del empleo de los radioisotopos en la medicina. El autor compara los esquemas de sensibilidad de diversos sistemas de colimacion y calcula su eficacia y su poder de resolucion. Los sistemas de coliminacion de que se trata se componen de orificios cilindricos y cenicos, de colimadores de enfoque y de dispositivos que permitan detectar por coincidencia las radiaciones de aniquilacion. Formula una teoria general con miras a establecer la concentracion optima de isotopos para cada uno de los sistemas. El autor enuncia una teoria analoga con respecto a la camara de centelleo, y compara la concentracion optima de isotopos para este dispositivo en relacion con los resultados logrados con ayuda de los distintos metodos de exploracion. Estudia tambien la posibilidad de modificar el principio de la camara a fin de utilizarla en la deteccion de las radiaciones de aniquilacion. Para terminar, compara diversos sistemas de registre desde el punto de vista de su eficacia y de la presentacion de los datos. (author) [Russian] Vozmozhnost' tochno ustanovit' raspredelenie izotopov yavlyaetsya vazhnym aspektom ispol'zovaniya ikh v meditsine. Sravnivaetsya stepen' chuvstvitel'nosti razlichnykh sistem kollimirovaniya, ustanavlivaetsya ikh ehffektivnost' i razreshayushchaya sposobnost'. Rassmatrivaemye kollimiruyushchie sistemy sostoyat iz tsilindricheskikh i konusnykh otverstij, fokusiruyushchikh kollimatorov i prispo-soblenij dlya obnaruzheniya annigilyatsionnogo izlucheniya metodom sovpadenij. Vyrabatyvaetsya obshchaya teoriya s tsel'yu ustanovit' optimal'nuyu kontsentratsiyu izotopov dlya kazhdoj iz ehtikh sistem. Podobnaya zhe teoriya razrabatyvaetsya i dlya stsintillyatsionnoj kamery; pro voditsya sravnenie optimal'noj kontsentratsii izotopov ehtogo pribora v svyazi s primenyaemymi metodami issledovaniya. Obsuzhdaetsya vopros ob izmenenii printsipa dejstviya kamery v tselyakh ispol'zovaniya ee pri nalichii annigilya-tsionnogo izlucheniya. Sravnivayutsya razlichnye sistemy

Present Status of Nitrogen Fixation by Reactor Radiation; Etat Actuel des Recherches sur l'oxydation directe de l'azote sous irradiation dans des reacteurs; Sovremennoe sostoyani opytov po okisleniyu azota izlucheniem iz reaktorov; Estado actual de las investigaciones sobre fijacion del nitrogeno por irradiacion en reactores

Energy Technology Data Exchange (ETDEWEB)

Harteck, P; Dondes, S [Rensselaer Polytechnic Institute, Troy, NY (United States)

1960-07-15

fision liberada en las fibras de vidrio y de la resistencia termica del circuito. Otro circuito, que habra de funcionar a 50 - 75 atmosferas y 600{sup o}C se encuentra en curso de construccion. Estos circuitos permitiran evaluar las caracteristicas de un sistema continuo, incluido el comportamient o de los productos de fision liberados en la corriente gaseosa. Los autores distinguen tres fases en la cinetica compleja de la oxidacion del nitrogeno: reacciones iniciales en el sistema;, reacciones subsiguientes a la fijacion de cierta cantidad de nitrogeno y, por ultimo, cinetica del equilibrio alcanzado en presencia de radiaciones. Se estudian las condiciones necesarias para la formacion de N{sub 2}0{sub 5}, N{sub 2}0{sub 4} y O{sub 3}, asi como los efectos que ejercen sobre el proceso en conjunto. (author) [Russian] Pri issledovaniyakh okisleniya azota izlucheniem iz reaktorov, kotorye proizvodilis ' v Rensselerovskom institute i v Brukkhejvenskoj natsional'noj laboratorii v techenie ryada let, byla ispol'zovana, v kachestve neposredstvennogo ioniziruyushchego izlucheniya, ehnergiya otdachi oskolkov deleniya putem rasseyaniya urana-235 v steklyannom volokne diametrom priblizitel'no v 5 mikronov. Bylo opredeleno vliyanie temperatury, davleniya i sootnosheniya mezhdu kolichestvom azota i kolichestvom kisloroda na velichinu radiatsionno-khimicheskogo vykhoda G na okislenie azota i rezul'taty byli soobshcheny v tekhnicheskoj literature. Nizhe daetsya kratkaya svodka ehtoj raboty. Upomyanutaya vyshe rabota proizvodilas' nad staticheskimi sistemami ; nedavno proizvedennaya rabota okhvatyvala kak staticheskie, tak i tsiklicheskie sistemy. V staticheskikh sistemakh glavnoe vnimanie obrashchalos' na vliyanie intensivnosti izlucheniya, v osobennosti v sostoyanii kineticheskogo ravnovesiya izlucheniya. Bylo ustanovleno, chto obrazovanie N0{sub 2}. i N{sub 2}0 V smesyakh azota i kisloroda v proportsiyakh 4:1 i 2: 1 proiskhodit do polnogo istoshcheniya yusloroda. TSiklicheskaya

The Heidelberg Basin Drilling Project - Sedimentology and Stratigraphy of the Quaternary succession

Science.gov (United States)

Ellwanger, Dietrich; Gabriel, Gerald; Hahne, Jürgen; Hoselmann, Christian; Menzies, John; Simon, Theo; Weidenfeller, Michael; Wielandt-Schuster, Ulrike

2010-05-01

Within the context of the Heidelberg Basin Drilling Project (Gabriel et al. 2008), a detailed sediment succession is presented here based upon deep drillings taken at Heidelberg UniNord and Mannheim Käfertal. Sediment structures, and micromorphological and pollen analyses were conducted and used to reconsider some of the climate transitions within the lower Pleistocene. A new and novel scenario is postulated regarding the preservation of Quaternary sediment packages within the Cenozoic Graben environment of the Heidelberg basin. The palynological evidence comprises the periods of warm climate of the Holsteinian (mainly Abies (fir), some Fagus (beech), Pterocarya & Azolla); the Cromerian (Pinus-Picea-QM (pine-spruce-QM)); the Bavelian (Abies, Tsuga (hemlock fir), QM & phases of increased NAP including Pinus); the Waalian (Abies, Tsuga, QM); and the Tiglian (Fagus & early Pleistocene taxa especially Sciadopytis, downward increasing Tertiary taxa). The sediment package was studied both macroscopically and microscopically. Both techniques provide evidence of fluvial, lacustrine and mass movement sedimentary processes. Some include evidence of periglacial processes (silt droplets within fine grained sands indicative of frozen ground conditions). The periglacial structures are often, not always, accompanied by pollen spectra dominated by pine and NAP. E.g. the Tiglian part of the succession shows periglacial sediment structures at its base and top but not in its middle sections. I.e. it appears not as a series of warm and cold phases but rather as a constant warm period with warm-cold-alternations at its bottom and top. All results illustrate sediment preservation in the Heidelberg basin almost throughout the Quaternary. This may be due to tectonic subsidence, but also to compaction by sediment loading of underlying fine sediments (Oligocene to Quaternary) leading to incomplete but virtually continuous sediment preservation (Tanner et al. 2009). References Gabriel, G

Chronic impacts of invasive herbivores on a foundational forest species: a whole-tree perspective.

Science.gov (United States)

Wilson, Claire M; Schaeffer, Robert N; Hickin, Mauri L; Rigsby, Chad M; Sommi, Amanda F; Thornber, Carol S; Orians, Colin M; Preisser, Evan L

2018-05-05

Forests make up a large portion of terrestrial plant biomass, and the long-lived woody plants that dominate them possess an array of traits that deter consumption by forest pests. Although often extremely effective against native consumers, invasive species that avoid or overcome these defenses can wreak havoc on trees and surrounding ecosystems. This is especially true when multiple invasive species co-occur, since interactions between invasive herbivores may yield non-additive effects on the host. While the threat posed by invasive forest pests is well known, long-term field experiments are necessary to explore these consumer-host interactions at appropriate spatial and temporal scales. Moreover, it is important to measure multiple variables to get a 'whole-plant' picture of their combined impact. We report the results of a four-year field experiment addressing the individual and combined impacts of two invasive herbivores, the hemlock woolly adelgid (Adelges tsugae) and elongate hemlock scale (Fiorinia externa), on native eastern hemlock (Tsuga canadensis) in southern New England. In 2011, we planted 200 hemlock saplings into a temperate forest understory and experimentally manipulated the presence/absence of both herbivore species; in 2015, we harvested the 88 remaining saplings and assessed plant physiology, growth, and resource allocation. Adelgids strongly affected hemlock growth: infested saplings had lower above/belowground biomass ratios, more needle loss, and produced fewer new needles than control saplings. Hemlock scale did not alter plant biomass allocation or growth, and its co-occurrence did not alter the impact of adelgid. While both adelgid and scale impacted the concentrations of primary metabolites, adelgid effects were more pronounced. Adelgid feeding simultaneously increased free amino acids local to feeding sites and a ~30% reduction in starch. The cumulative impact of adelgid-induced needle loss, manipulation of nitrogen pools, and the loss

Recominant Pinoresino-Lariciresinol Reductase, Recombinant Dirigent Protein And Methods Of Use

Science.gov (United States)

Lewis, Norman G.; Davin, Laurence B.; Dinkova-Kostova, Albena T.; Fujita, Masayuki , Gang; David R. , Sarkanen; Simo , Ford; Joshua D.

2003-10-21

Dirigent proteins and pinoresinol/lariciresinol reductases have been isolated, together with cDNAs encoding dirigent proteins and pinoresinol/lariciresinol reductases. Accordingly, isolated DNA sequences are provided from source species Forsythia intermedia, Thuja plicata, Tsuga heterophylla, Eucommia ulmoides, Linum usitatissimum, and Schisandra chinensis, which code for the expression of dirigent proteins and pinoresinol/lariciresinol reductases. In other aspects, replicable recombinant cloning vehicles are provided which code for dirigent proteins or pinoresinol/lariciresinol reductases or for a base sequence sufficiently complementary to at least a portion of dirigent protein or pinoresinol/lariciresinol reductase DNA or RNA to enable hybridization therewith. In yet other aspects, modified host cells are provided that have been transformed, transfected, infected and/or injected with a recombinant cloning vehicle and/or DNA sequence encoding dirigent protein or pinoresinol/lariciresinol reductase. Thus, systems and methods are provided for the recombinant expression of dirigent proteins and/or pinoresinol/lariciresinol reductases.

Measurement of imidacloprid in xylem fluid from eastern hemlock (Tsuga canadensis) by derivitization/GC/MS and ELISA

Science.gov (United States)

Anthony Lagalante; Peter Greenbacker; Jonathan Jones; Richard Turcotte; Bradley Onken

2007-01-01

Imidacloprid is a nonvolatile insecticide and its direct quantification is not possible by gas chromatography. In order to ascertain imidacloprid levels in soil and trunk injection treated trees, a sensitive and selective method has been developed using GC/MS to measure the imidacloprid levels in xylem fluid exudates. In May 2005, a stand of hemlock trees in West...

Vegetation Response to Upper Pliocene Glacial/Interglacial Cyclicity in the Central Mediterranean

Science.gov (United States)

Combourieu-Nebout, Nathalie

1993-09-01

New detailed pollen analysis of the lower part of the Upper Pliocene Semaforo section (Crotone, Italy) documents cyclic behavior of vegetation at the beginning of the Northern Hemisphere glaciations. The competition between four vegetation units (subtropical humid forest, deciduous temperate forest, altitudinal coniferous forest, and open xeric assemblage) probably reflects modifications of vegetation belts at this montane site. Several increases in herbaceous open vegetation regularly alternate with subtropical humid forest, which expresses rapid climatic oscillations. The complete temporal succession—deciduous forest (rich in Quercus), followed by subtropical humid forest (Taxodiaceae and Cathaya), then altitudinal coniferous forest ( Tsuga, Cedrus, Abies, and Picea), and finally herbaceous open vegetation (Graminae, Compositae, and Artemisia )—displays the climatic evolution from warm and humid interglaciation to cold and dry glaciation. It also suggests an independent variation of temperature and humidity, the two main climatic parameters. The vegetation history of southern Calabria recorded in the Semaforo section have been correlated with the ∂ 18O signal established in the Atlantic Ocean.

The Main Technological Characteristics of Apparatus for Industrial Radiochemical Processes, in Particular Ethylene Polymerization; Caracteristique techniques fondamentals des appareils pour l'application industrielle de reactions chimiques sous rayonnement (notamment la polymerisation de l'ethylene ); Osnovnye tekhnologicheskie kharakteristiki apparatov dlya provedeniya radiatsionno-khimi-cheskikh protsessov (v chastnosti, dlya polimerizatsii ehtilena) v promyshlennom masshtabe; Principales caracteristicas tecnologicas de los aparatos para la aplicacion industrial de reacciones radioquimicas

Energy Technology Data Exchange (ETDEWEB)

Syrkus, N P; Breger, A K; Weinstein, B I [Karpov Physicochemical Institute, Moscow, USSR (Russian Federation)

1960-07-15

, Q {approx} W{sub 0}{sup 0'5}. (author) [Spanish] Se propone un metodo de evaluacion de la efectividad de los aparatos, cualquiera que sea su construccion, comparandola con la productividad de un aparato infinitamente grande que tenga la misma fuente de radiaciones. Se indican las caracteristicas tecnologicas de un aparato destinado a la polimerizacion del etileno mediante radiaciones (a presion de 200 atmosferas y temperatura de 25{sup o} C{sup 4} empleando como fuente principal radiaciones gamma de cobalto-60 a distintas actividades. Se pueden calcular los datos tecnicos de tal aparato segun el valor medio de la intensidad de las dosis, fijado segun la magnitud del coeficiente de rendimiento energetico del aparato. Se indica en el trabajo que, siendo las demas condiciones iguales, la productividad (Q) del aparato es funcion exponencial de la intensidad (W{sub 0}) de las radiaciones gamma del mismo. Para el aparato que se estudia en el trabajo la formula es: Q{approx}W{sub 0}{sup 0'5}. (author) [Russian] V doklade rassmotreny v obshchem vide otdel'nye naibolee vazhnye tekhnologicheskie kharakteristiki apparatov (na primere sfericheskogo apparata) dlya provedeniya radiatsionno-khimicheskikh protsessov v promyshlennom masshtabe. Predlozhen metod otsenki ehffektivnosti apparata lyuboj konstruktsii putem sravneniya s proizvoditel'nost' yu beskonechno bol'shogo apparata, imeyushchego tot zhe istochnik izlucheniya. Priveden raschet tekhnologicheskoj kharakteristiki apparata dlya radiatsionnoj polimerizatsii ehtilena (davlenie 200 atm, temperatura 25{sup o} C{sup 3} so sterzhnevym istochnikom gamma-izlucheni ya Co{sup 60} razlichnoj aktivnosti. Takoj apparat mozhno rasschityvat' po srednim znacheniyam moshchnostej doz, opredelyaemym po velichine ehnergeticheskogo KPD apparata. Pokazano, chto proizvoditel'nost'apparata (Q), pri prochikh ravnykh usloviyakh, yavlyaetsya stepennoj funktsiej moshchnosti (W{sub 0}) gamma-izlucheniya apparata. Dlya rassmotrennogo apparata : Q

Tree host range and world distribution of the extomycorrhizal fungus Pisolithus tinctorius.

Science.gov (United States)

Marx, D H

1977-03-01

The natural occurrence of Pisolithus tinctorius has been confirmed in 33 countries of the world and in 38 states in the United States. This ectomycorrhizal fungus is found associated with various tree species in nurseries, urban areas, orchards, forests, and strip-mined spoils. Experiments have proved that this fungal symbiont forms ectomycorrhizae with Abies procera, Betula pendula, Carya illnoensis, 11 species of Eucalyptus, 30 species of Pinus, Pseudotsuga menziesii var. meniziesii, 2 species of Quercus, and Tsuga heterophylla. Pisolithus has also been reported growing under natural conditions in association with three additional species of Betula, two species of Eucalyptus, nine species of Pinus, and eight species of Quercus, Populus tremuloides, Pseudotsuga grandidenta, and Salix humilis. This fungal symbiont has great potential in forestation efforts because of (1) the availability of practical techniques for artificially introducing in into nursery soils; (2) its ability to improve tree survival and growth in the nursery and the field; (3) its near worldwide distribution on a variety of sites; and (4) its broad host range encompassing many of the world's most important tree species.

Reproductive state of health as a criterion for deterministic effects of low radiation doses; Sostoyanie reproduktivnogo zdorovya kak kriterij determinirovannykh effecktov malykh doz izlucheniya

Energy Technology Data Exchange (ETDEWEB)

Buldakov, L A; Vasilenko, I Ya; Demin, S I; Lyaginskaya, A M; Saurov, M M [Russian Federation State Science Centre, Biophysics Inst., Moscow (Russian Federation)

1997-09-01

Changes of such indicators of reproductive health like stillbirth, neonates sick rate, frequency of genetic malformations, neonate mortality immediately after the Chernobyl catastrophe as well as after a long period (Southern Ural) after irradiation, show a positive correlation with the radiation dose. The reproductive health is the most important social indicator of the well being of individuals or population. Deterioration of the reproductive health indicators in Central Russia was proved to depend very significantly on on the degree of soil contamination by cesium-137, and on radiation doses received by the population. 1 tab.

Characteristics of background radiation behind one-dimensional radiation shielding of high-energy particle beams; Kharakteristiki fonovogo izlucheniya za odnomernymi radiatsionnymi zashchitami puchkov vysokoehnergeticheskikh chastits

Energy Technology Data Exchange (ETDEWEB)

Gorbatkov, D V; Kryuchkov, V P

1994-12-31

The calculational investigations of component, spatial and energy distributions of background radiation behind radiation shielding of high-energy hadron beams were carried out. The relations between different ingredients of radiation have been obtained. The numerous data of spatial and energy distribution of protons, neutrons, pions and photons in homogeneous and heterogeneous shielding from concrete and iron, presented in the paper, can be used as a reference data. 23 refs., 50 figs.

Influences of Forest Tree Species and Early Spring Temperature on Surface-Atmosphere Transfers of Water and Carbon in the Northeastern U.S.

Science.gov (United States)

Hadley, J. L.; Kuzeja, P.; Mulcahy, T.; Singh, S.

2008-12-01

Influences of Forest Tree Species and Early Spring Temperature on Surface-Atmosphere Transfers of Water and Carbon in the Northeastern U.S. Julian Hadley, Paul Kuzeja, Safina Singh and Thomas Mulcahy Transfers of water vapor from terrestrial ecosystems to the atmosphere affect regional hydrology, weather and climate over short time scales, and forest-atmosphere CO2 exchange affects global climate over long timescales. To better understand these effects for forests dominated by two very different tree species, we measured forest-atmosphere water vapor and CO2 transfers by the eddy flux technique to at two sites in central Massachusetts USA for three years. Average annual evapotranspiration (ET) for a young deciduous forest dominated by red oak (Quercus rubra L., the most abundant tree species in the area), was about 430 mm or 25 percent greater than for a coniferous forest dominated by 100 to 230 year old eastern hemlock (Tsuga canadensis L.). The difference in ET was most pronounced in July and August when the deciduous forest lost about 50 percent more water by ET in the average year (192 mm for oak forest versus 130 mm for hemlock). These data indicate that if deciduous trees with similar physiology to red oak replace hemlocks, summertime ET will increase while summer streamflow, soil water content and the extent of year- round wetlands will decrease. Increased summertime ET should also lead to slightly higher regional atmospheric humidity and precipitation. Hemlock-to-deciduous forest conversion has occurred from North Carolina to southern New England and is continuing northward as a lethal insect pest, the hemlock woolly adelgid (Adelges tsugae Annand) continues to kill hemlocks. Average annual carbon storage for the old hemlock forest in our study was about 3.3 Mg C/ha, nearly equal to the average for the deciduous forest, 3.5 Mg C/ha. This calls into question ecological theory that predicts large declines in the rate of carbon uptake for old forests, and

The distribution of a pure beta-emitter in the human body. Problems and preliminary results of Bremsstrahlung measurements in vivo; La repartition d'un emetteur beta pur dans l'organisme humain. Problemes poses par les mesures in vivo du rayonnement de freinage et premiers resultats obtenus; Raspredelenie chistogo beta-izluchatel ya v chelovecheskom organizme Problemy i predvaritel'ny e rezul'taty izmerenij tormoznogo izlucheniya v zhivom organizme; Distribucion de un emisor beta puro en el organisme humano. Problemas planteados por las mediciones in vivo de la radiacion de frenado y resultados preliminares obtenidos

Energy Technology Data Exchange (ETDEWEB)

Mehl, H G [Strahleninstitut der Freien Universitaet, Berlin (Germany)

1959-07-01

la profondeur a laquelle l'organe examine se trouve situe. L'examen des resultats deja publies de ces mesures permettra de reconnaitre la situation actuelle et de determiner la nature des problemes qui restent a resoudre. (author) [Spanish] Las mediciones in vivo de la distribucion de un emisor beta puro en el organismo humano se limitaban antes a localizar la radiactividad en los tejidos superficiales unicamente, a causa del reducido alcance de las particules beta en los tejidos. En los ultimos anos, gracias a las mediciones de la radiacion de frenado se ha podido analizar la actividad en los tejidos profundos. El autor estudia los problemas planteados por esta nueva tecnica y los resultados que permite obtener. Describe la construccien de detectores apropiados, basandose en un analisis de las caracteristicas fisicas de esta radiacion. Examina la labor teorica y experimental realizada en este campo. Para poder interpretar acertadamente los resultados obtenidos, es necesario analizar los diversos factores que entran en juego, especialmente el area por el detector, la actividad especifica del tejido observado y la profundidad del organo objeto de examen. Un estudio de los resultados de esas mediciones ya publicadas permitira evaluar la situacion actual y la naturaleza de los problemas que aun no se han resuelto. (author) [Russian] Izmereniya raspredeleniya chistogo beta-izluchatel ya v chelovecheskom organizme do sikh por ogranichivalis', vvidu malogo puti proniknoveniya beta-chastits v tkani, ustanovleniem nalichiya radioaktivnost i tol'ko v poverkhnostny kh tkanyakh. Za poslednie neskol'ko let primenenie izmerenij tormoznogo izlucheniya pozvolilo rasprostranit' ehtot metod na analiz aktivnosti gluboko zalegayushchikh tkanej. V nastoyashchem dokumente rassmatrivayuts ya problemy i rezul'taty ispol'zovaniya ehtogo novogo priema raboty. Na osnovanii analiza fizicheskogo kharaktera ehtoj radiatsii v dokumente rassmatrivaets ya takzhe konstruktsiya

Testing Methods for Challenging the National Wetland Plant List: Using Tsuga canadensis (L.) Carr. (Eastern Hemlock) as a Case Study

Science.gov (United States)

2017-07-01

frame were constructed based on GIS data (Table 1) and habitat descriptions of areas where T. canadensis was likely to occur, such as wooded swamps...6 2.1 Small study areas (100 km2) ......................................................................................... 6 2.1.1 Constructing a...Western Ecology Division are thanked for their procedural reviews and recommendations for improving the study design. Ms. Lindsey Lefebvre, Ms

Asymmetric biotic interactions and abiotic niche differences revealed by a dynamic joint species distribution model.

Science.gov (United States)

Lany, Nina K; Zarnetske, Phoebe L; Schliep, Erin M; Schaeffer, Robert N; Orians, Colin M; Orwig, David A; Preisser, Evan L

2018-05-01

A species' distribution and abundance are determined by abiotic conditions and biotic interactions with other species in the community. Most species distribution models correlate the occurrence of a single species with environmental variables only, and leave out biotic interactions. To test the importance of biotic interactions on occurrence and abundance, we compared a multivariate spatiotemporal model of the joint abundance of two invasive insects that share a host plant, hemlock woolly adelgid (HWA; Adelges tsugae) and elongate hemlock scale (EHS; Fiorina externa), to independent models that do not account for dependence among co-occurring species. The joint model revealed that HWA responded more strongly to abiotic conditions than EHS. Additionally, HWA appeared to predispose stands to subsequent increase of EHS, but HWA abundance was not strongly dependent on EHS abundance. This study demonstrates how incorporating spatial and temporal dependence into a species distribution model can reveal the dependence of a species' abundance on other species in the community. Accounting for dependence among co-occurring species with a joint distribution model can also improve estimation of the abiotic niche for species affected by interspecific interactions. © 2018 by the Ecological Society of America.

Multi-decade biomass dynamics in an old-growth hemlock-northern hardwood forest, Michigan, USA

Directory of Open Access Journals (Sweden)

Kerry D. Woods

2014-09-01

Full Text Available Trends in living aboveground biomass and inputs to the pool of coarse woody debris (CWD in an undisturbed, old-growth hemlock-northern hardwood forest in northern MI were estimated from multi-decade observations of permanent plots. Growth and demographic data from seven plot censuses over 47 years (1962–2009, combined with one-time measurement of CWD pools, help assess biomass/carbon status of this landscape. Are trends consistent with traditional notions of late-successional forests as equilibrial ecosystems? Specifically, do biomass pools and CWD inputs show consistent long-term trends and relationships, and can living and dead biomass pools and trends be related to forest composition and history? Aboveground living biomass densities, estimated using standard allometric relationships, range from 360–450 Mg/ha among sampled stands and types; these values are among the highest recorded for northeastern North American forests. Biomass densities showed significant decade-scale variation, but no consistent trends over the full study period (one stand, originating following an 1830 fire, showed an aggrading trend during the first 25 years of the study. Even though total above-ground biomass pools are neither increasing nor decreasing, they have been increasingly dominated, over the full study period, by very large (>70 cm dbh stems and by the most shade-tolerant species (Acer saccharum and Tsuga canadensis.CWD pools measured in 2007 averaged 151 m3/ha, with highest values in Acer-dominated stands. Snag densities averaged 27/ha, but varied nearly ten-fold with canopy composition (highest in Tsuga-dominated stands, lowest in Acer-dominated; snags constituted 10–50% of CWD biomass. Annualized CWD inputs from tree mortality over the full study period averaged 1.9–3.2 Mg/ha/yr, depending on stand and species composition. CWD input rates tended to increase over the course of the study. Input rates may be expected to increase over longer

Effects of Gamma Radiation on Three Species of Philippine Insect Pests; Effets des rayons gamma sur trois especes d'insectes nuisibles des Philippines; Dejstvie gamma-izlucheniya na tri raznovidnosti nasekomykh-vreditelej na Filippinakh; Efectos de las radiaciones gamma sobre tres plagas insectiles de las Filipinas

Energy Technology Data Exchange (ETDEWEB)

Viado, G. B.; Manoto, E. C. [Philippine Atomic Energy Commission, National Science Development Board, Manila (Philippines)

1963-09-15

, el porcentaje de huevos hueros de Epilachna fue aproximadamente del 10%. La dosis de.5 kr no provoco un aumento proporcional de la mortalidad, pero con 10 kr la letalidad fue el triple que la correspondiente a 5 kr. Con una dosis de 20 kr, el indice de mortalidad alcanzo aproximadamente el 90%. Al parecer, la dosis umbral esta comprendida entre 5 y 10 kr. En los huevos sin abrir, el embrion dejo de desarrollarse. Con 1 kr, murieron mas del 20% de las larvas, aunque algunas de ellas llegaron a formar ninfas. La mayor parte de las larvas alcanzaron el estado adulto. Las larvas que sobrevinieron a dosis de mas de 1 kr, algunas durante hasta cuatro semanas, murieron sin llegar a formar ninfas. Las ninfas resultaron mas resistentes que las larvas y los insectos adultos, pues la mortalidad completa no se alcanzo ni siquiera con dosis de 20 kr. Algunos de los adultos que surgieron de los grupos que habian sido expuestos a dosis de 5 y 10 kr tenian alas y/o patas anormales. Las dosis de 10 kr matan aproximadamente al 75% d e los adultos a las tres semanas de haberlos irradiado, y 20 kr bastan para matar a todos al cabo del mismo tiempo. No se registraron diferencias importantes entre los sexos en cuanto a la sensibilidad. Aproximadamente el 40% de los S. oryzae que habian recibido dosis de 60 y 80 kr murieron una semana despues de la irradiacion; en cambio, las dosis de 20 kr solo mataron a un 10% y las de 40 kr al 20%. La mortalidad con dosis de 40, 60 y 80 kr aumento hasta un 75% a las dos semanas de haber comenzado el ensayo. La mortalidad con 10 kr correspondiente a este periodo resulto inferior al 10%, y con 20 kr alcanzo aproximadamente el 25%. Al parecer, la dosis umbral parece encontrarse entre 20 y 40 kr. La mortalidad en el caso del T. castaneum resulto similar que para el S. oryzae, con la salvedad de que la dosis umbral parece encontrarse hacia los 40 kr. (author) [Russian] Izuchalos' dejstvie gamma-izlucheniya ot istochnika Co{sup 60} na trekh sel

High-Elevation Sierra Nevada Conifers Reveal Increasing Reliance on Snow Water with Changing Climate

Science.gov (United States)

Lepley, K. S.; Meko, D. M.; Touchan, R.; Shamir, E.; Graham, R.

2017-12-01

Snowpack in the Sierra Nevada Mountains accounts for around one third of California's water supply. Melting snow can provide water into dry summer months characteristic of the region's Mediterranean climate. As climate changes, understanding patterns of snowpack, snowmelt, and biological response are critical in this region of agricultural, recreational, and ecological value. Tree rings can act as proxy records to inform scientists and resource managers of past climate variability where instrumental data is unavailable. Here we investigate relationships between tree rings of high-elevation, snow-adapted conifer trees (Tsuga mertensiana, Abies magnifica) and April 1st snow-water equivalent (SWE) in the northern Sierra Nevada Mountains. The 1st principal component of 29 highly correlated regional SWE time series was modeled using multiple linear regression of four tree-ring chronologies including two lagged chronologies. Split-period verification analysis of this model revealed poor predictive skill in the early half (1929 - 1966) of the calibration period (1929 - 2003). Further analysis revealed a significant (p time. Snow water is becoming a more limiting resource to tree growth as average temperatures rise and the hydrologic regime shifts. These results highlight the need for resource managers and policy makers to consider that biological response to climate is not static.

Laser incising of wood: Impregnation of columns with water-soluble dye

International Nuclear Information System (INIS)

Hattori, N.; Ando, K.; Kitayama, S.; Nakamura, Y.

1994-01-01

To know whether or not laser incising is a useful pre-treatment technique in impregnating a chemical fluid into lumber, pin holes were made in columns of hinoki (Chamaecyparis obtusa Endl.), sugi (Cryptomeria japonica D. Don), karamatsu (Larix leptolepis Gordon) and douglas-fir (Pseudo-tsuga menziesii Franco) with 1.7 kW CO2 laser, and a water-soluble dye was impregnated into these columns with a local pressure impregnation device. Retentions, and lengths and widths of penetrations from each hole were measured quantitatively. Referring to the results of the preparatory experiment mentioned above, incising patterns for sugi and douglas-fir were designed, and the same water-soluble dye was impregnated into the laser-incised columns as well as into non-incised ones with the vacuum-pressure method to obtain penetrated layers with the target depths completely. As a result, a retention of 200 kg/m3 of dye could be achieved for a column of douglas-fir even if it is a species difficult to impregnate. The penetrated layer also could be formed completely at the depth of the laser incision. Therefore, it is concluded that laser incising can be used for the pre-treatment before impregnation of wood columns. (author)

Secondary metabolites from Ganoderma.

Science.gov (United States)

Baby, Sabulal; Johnson, Anil John; Govindan, Balaji

2015-06-01

Ganoderma is a genus of medicinal mushrooms. This review deals with secondary metabolites isolated from Ganoderma and their biological significance. Phytochemical studies over the last 40years led to the isolation of 431 secondary metabolites from various Ganoderma species. The major secondary compounds isolated are (a) C30 lanostanes (ganoderic acids), (b) C30 lanostanes (aldehydes, alcohols, esters, glycosides, lactones, ketones), (c) C27 lanostanes (lucidenic acids), (d) C27 lanostanes (alcohols, lactones, esters), (e) C24, C25 lanostanes (f) C30 pentacyclic triterpenes, (g) meroterpenoids, (h) farnesyl hydroquinones (meroterpenoids), (i) C15 sesquiterpenoids, (j) steroids, (k) alkaloids, (l) prenyl hydroquinone (m) benzofurans, (n) benzopyran-4-one derivatives and (o) benzenoid derivatives. Ganoderma lucidum is the species extensively studied for its secondary metabolites and biological activities. Ganoderma applanatum, Ganoderma colossum, Ganoderma sinense, Ganoderma cochlear, Ganoderma tsugae, Ganoderma amboinense, Ganoderma orbiforme, Ganoderma resinaceum, Ganoderma hainanense, Ganoderma concinna, Ganoderma pfeifferi, Ganoderma neo-japonicum, Ganoderma tropicum, Ganoderma australe, Ganoderma carnosum, Ganoderma fornicatum, Ganoderma lipsiense (synonym G. applanatum), Ganoderma mastoporum, Ganoderma theaecolum, Ganoderma boninense, Ganoderma capense and Ganoderma annulare are the other Ganoderma species subjected to phytochemical studies. Further phytochemical studies on Ganoderma could lead to the discovery of hitherto unknown biologically active secondary metabolites. Copyright © 2015 Elsevier Ltd. All rights reserved.

A comparative toxicity assessment of materials used in aquatic construction.

Science.gov (United States)

Lalonde, Benoit A; Ernst, William; Julien, Gary; Jackman, Paula; Doe, Ken; Schaefer, Rebecca

2011-10-01

Comparative toxicity testing was performed on selected materials that may be used in aquatic construction projects. The tests were conducted on the following materials: (1) untreated wood species (hemlock [Tsuga ssp], Western red cedar (Thuja plicata), red oak [Quercus rubra], Douglas fir [Pseudotsuga menziesii], red pine [Pinus resinosa], and tamarack [Larix ssp]); (2) plastic wood; (3) Ecothermo wood hemlock stakes treated with preservatives (e.g., chromated copper arsenate [CCA], creosote, alkaline copper quaternary [ACQ], zinc naphthenate, copper naphthenate, and Lifetime Wood Treatment); (4) epoxy-coated steel; (5) hot-rolled steel; (6) zinc-coated steel; and (7) concrete. Those materials were used in acute lethality tests with rainbow trout, Daphnia magna, Vibrio fischeri and threespine stickleback. The results indicated the following general ranking of the materials (from the lowest to highest LC(50) values); ACQ > creosote > zinc naphthenate > copper naphthenate > CCA (treated at 22.4 kg/m(3)) > concrete > red pine > western red cedar > red oak > zinc-coated steel > epoxy-coated steel > CCA (6.4 kg/m(3)). Furthermore, the toxicity results indicated that plastic wood, certain untreated wood species (hemlock, tamarack, Douglas fir, and red oak), hot-rolled steel, Ecothermo wood, and wood treated with Lifetime Wood Treatment were generally nontoxic to the test species. © Springer Science+Business Media, LLC 2011

Impacts of dwarf mistletoe on the physiology of host Tsuga heterophylla trees as recorded in tree-ring C and O stable isotopes

Science.gov (United States)

D. E. Marias; F. C. Meinzer; D. R. Woodruff; D. C. Shaw; S. L. Voelker; Steven W. Oak; William J. Otrosina; William D. Smith; Kamal J.K. Gandhi

2014-01-01

Dwarf mistletoes, obligate, parasitic plants with diminutive aerial shoots, have long-term effects on host tree water relations, hydraulic architecture and photosynthetic gas exchange and can eventually induce tree death. To investigate the long-term (1886–2010) impacts of dwarf mistletoe on the growth and gas exchange characteristics of host western hemlock, we...

Impacts of dwarf mistletoe on the physiology of host Tsuga heterophylla trees as recorded in tree ring C and O stable isotopes

Science.gov (United States)

• Dwarf mistletoes, obligate, parasitic plants with diminutive aerial shoots, have long-term effects on host tree water relations, hydraulic architecture, and photosynthetic gas exchange and can eventually induce tree death. • To investigate long-term impacts of dwarf mistletoe...

Low-Level {beta} and {gamma} Counting in the Region 0-10 Disintegrations Per Minute; Comptage {beta} et {gamma} d'echantillons de faible activite (0 a 10 desintegrations par minute); Izmerenie {beta}- i {gamma}-izlucheniya maloj moshchnosti (0-10 raspadov v minutu); Recuento {beta} y {gamma} de muestras de baja actividad (0 a 10 desintegraciones por minuto)

Energy Technology Data Exchange (ETDEWEB)

Manov, George G [Tracerlab Inc. (United States)

1960-06-15

(antisovpadenij) dlya umen'sheniya fona. Izmereniya proizvodilis' s pomoshch'yu sleduyushchikh tipov schetchikov: a) toptsevym, b) tsilindricheskim, s) stsitillyatsionnym 4 {pi}. V dokumente udelyaetsya nekotoroe vnimanie trudnostyam polucheniya svobodnogo ot aktivnosti materiala, ispol'zuemogo dlya proizvodstva schetchikov. V nem privodyatsya dannye o materialakh s razlichnym soderzhaniem aktivnosti, kotorye mozhno svobodno priobresti. Nakoplenie takikh materialov, poluchennykh preimushchestvenn o eshche do vtoroj mirovoj vojny, bystro prevrashchaetsya v neobkhodimost'. Nadezhnost' ehlektronnoj sistemy yavlyaetsya neobkhodimoj dlya izmerenij izlucheniya maloj moshchnosti, v chastnosti, dlya togo, chtoby isklyuchit' podschet pobochnykh impul'sov. V dokumente daetsya opisanie sistemy, v kotoroj redkie impul'sy, posle izmereniya ikh skorosti, napravlyayutsya v ehlektronnuyu tsep', prokhodyat cherez usilitel' i vyvodyatsya cherez osnovnoj vykhodnoj kanal schetnogo mekhanizma. V osnovnom tranzistornaya skhema, vklyuchayushchaya predvaritel'noe usilenie i (ehlektro)pitanie , yavlyaetsya bolee udovletvoritel'noj, chem skhema, ispol'zuyushchaya vakuumnuyu lampu. (author)

Method to calculating an internal electromagnetic pulse generated in a system under gamma radiation effect; Metod rascheta vnutrennego ehlektromagnitnogo impul`sa, generiruemogo v sisteme pri vozdejstvii gamma-izlucheniya

Energy Technology Data Exchange (ETDEWEB)

Ogorodnikov, S N

1994-12-31

A method of calculating internal electromagnetic pulse, generated in the system under effect of gamma radiation is developed. Ratios for basic electron flux characteristics and components of electric and magnetic fields generated by gamma radiation, are indicated for a cylindrical cavity under gamma radiation effect on its surface. To illustrate this a case is considered when a single flux velocity component is present.

Tree-ring stable isotopes record the impact of a foliar fungal pathogen on CO(2) assimilation and growth in Douglas-fir.

Science.gov (United States)

Saffell, Brandy J; Meinzer, Frederick C; Voelker, Steven L; Shaw, David C; Brooks, J Renée; Lachenbruch, Barbara; McKay, Jennifer

2014-07-01

Swiss needle cast (SNC) is a fungal disease of Douglas-fir (Pseudotsuga menziesii) that has recently become prevalent in coastal areas of the Pacific Northwest. We used growth measurements and stable isotopes of carbon and oxygen in tree-rings of Douglas-fir and a non-susceptible reference species (western hemlock, Tsuga heterophylla) to evaluate their use as proxies for variation in past SNC infection, particularly in relation to potential explanatory climate factors. We sampled trees from an Oregon site where a fungicide trial took place from 1996 to 2000, which enabled the comparison of stable isotope values between trees with and without disease. Carbon stable isotope discrimination (Δ(13)C) of treated Douglas-fir tree-rings was greater than that of untreated Douglas-fir tree-rings during the fungicide treatment period. Both annual growth and tree-ring Δ(13)C increased with treatment such that treated Douglas-fir had values similar to co-occurring western hemlock during the treatment period. There was no difference in the tree-ring oxygen stable isotope ratio between treated and untreated Douglas-fir. Tree-ring Δ(13)C of diseased Douglas-fir was negatively correlated with relative humidity during the two previous summers, consistent with increased leaf colonization by SNC under high humidity conditions that leads to greater disease severity in following years. © 2013 John Wiley & Sons Ltd.

Tree species and soil nutrient profiles in old-growth forests of the Oregon Coast Range

Science.gov (United States)

Cross, Alison; Perakis, Steven S.

2011-01-01

Old-growth forests of the Pacific Northwest provide a unique opportunity to examine tree species – soil relationships in ecosystems that have developed without significant human disturbance. We characterized foliage, forest floor, and mineral soil nutrients associated with four canopy tree species (Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), western redcedar (Thuja plicata Donn ex D. Don), and bigleaf maple (Acer macrophyllum Pursh)) in eight old-growth forests of the Oregon Coast Range. The greatest forest floor accumulations of C, N, P, Ca, Mg, and K occurred under Douglas-fir, primarily due to greater forest floor mass. In mineral soil, western hemlock exhibited significantly lower Ca concentration and sum of cations (Ca + Mg + K) than bigleaf maple, with intermediate values for Douglas-fir and western redcedar. Bigleaf maple explained most species-based differences in foliar nutrients, displaying high concentrations of N, P, Ca, Mg, and K. Foliar P and N:P variations largely reflected soil P variation across sites. The four tree species that we examined exhibited a number of individualistic effects on soil nutrient levels that contribute to biogeochemical heterogeneity in these ecosystems. Where fire suppression and long-term succession favor dominance by highly shade-tolerant western hemlock, our results suggest a potential for declines in both soil Ca availability and soil biogeochemical heterogeneity in old-growth forests.

Age class, longevity and growth rate relationships: protracted growth increases in old trees in the eastern United States.

Science.gov (United States)

Johnson, Sarah E; Abrams, Marc D

2009-11-01

This study uses data from the International Tree-Ring Data Bank website and tree cores collected in the field to explore growth rate (basal area increment, BAI) relationships across age classes (from young to old) for eight tree species in the eastern US. These species represent a variety of ecological traits and include those in the genera Populus, Quercus, Pinus, Tsuga and Nyssa. We found that most trees in all age classes and species exhibit an increasing BAI throughout their lives. This is particularly unusual for trees in the older age classes that we expected to have declining growth in the later years, as predicted by physiological growth models. There exists an inverse relationship between growth rate and increasing age class. The oldest trees within each species have consistently slow growth throughout their lives, implying an inverse relationship between growth rate and longevity. Younger trees (trees when they are of the same age resulting from a higher proportion of fast-growing trees in these young age classes. Slow, but increasing, BAI in the oldest trees in recent decades is a continuation of their growth pattern established in previous centuries. The fact that they have not shown a decreasing growth rate in their old age contradicts physiological growth models and may be related to the stimulatory effects of global change phenomenon (climate and land-use history).

Paleoecology of a Northern Michigan Lake and the relationship among climate, vegetation, and Great Lakes water levels

Science.gov (United States)

Booth, R.K.; Jackson, S.T.; Thompson, T.A.

2002-01-01

We reconstructed Holocene water-level and vegetation dynamics based on pollen and plant macrofossils from a coastal lake in Upper Michigan. Our primary objective was to test the hypothesis that major fluctuations in Great Lakes water levels resulted in part from climatic changes. We also used our data to provide temporal constraints to the mid-Holocene dry period in Upper Michigan. From 9600 to 8600 cal yr B.P. a shallow, lacustrine environment characterized the Mud Lake basin. A Sphagnum-dominated wetland occupied the basin during the mid-Holocene dry period (???8600 to 6600 cal yr B.P.). The basin flooded at 6600 cal yr B.P. as a result of rising water levels associated with the onset of the Nipissing I phase of ancestral Lake Superior. This flooding event occured contemporaneously with a well-documented regional expansion of Tsuga. Betula pollen increased during the Nipissing II phase (4500 cal yr B.P.). Macrofossil evidence from Mud Lake suggests that Betula alleghaniensis expansion was primarily responsible for the rising Betula pollen percentages. Major regional and local vegetational changes were associated with all the major Holocene highstands of the western Great Lakes (Nipissing I, Nipissing II, and Algoma). Traditional interpretations of Great Lakes water-level history should be revised to include a major role of climate. ?? 2002 University of Washington.

Effects of rhododendron removal on the water use of hardwood species following eastern hemlock mortality

Science.gov (United States)

Hawthorne, S. N.; Miniat, C.; Elliott, K.

2017-12-01

Forest disturbance that alters vegetation species composition can affect ecosystem productivity and function. The loss of eastern hemlock (Tsuga canadensis) to hemlock woolly adelgid infestations in southern Appalachian Mountains has resulted in more than a two-fold increase in growth of co-occurring rhododendron (Rhododendron maximum) understory, evergreen shrubs. In contrast, the growth of hardwood species increased by 1.2 fold during the same 5 year period following infestation. This study examines the effects of mechanically removing the rhododendron shrub layer on water use and growth of hardwood species. The treatment—hypothesized to speed ecosystem recovery of structure and function—involved cutting, spreading and burning rhododendron stems to remove both rhododendron and soil O-horizon. Sap flow, soil moisture and micro-climate (humidity, temperature) were measured in a pair of reference and treated plots. Preliminary results from the relatively dry summer/fall 2016 have shown that the mean daily transpiration (Et) of the treated plot was 24% greater than the mean daily Et of hardwood trees in the reference plot (t-test, p treatment plots compared to the reference plots. This suggests that the removal of the shrub layer reduced competition for resources for the canopy and seedling trees, which may increase tree growth and recruitment. Thus, in the wake of hemlock loss, recovery of riparian forest structure and function may be aided with shrub layer removal.

Evidence for millennial-scale climate change during marine isotope stages 2 and 3 at Little Lake, Western Oregon, U.S.A.

Science.gov (United States)

Grigg, L.D.; Whitlock, C.; Dean, W.E.

2001-01-01

Pollen and geochemical data from Little Lake, western Oregon, suggest several patterns of millennial-scale environmental change during marine isotope stage (MIS) 2 (14,100-27,600 cal yr B.P.) and the latter part of MIS 3 (27,600-42,500 cal yr B.P.). During MIS 3, a series of transitions between warm- and cold-adapted taxa indicate that temperatures oscillated by ca. 2??-4??C every 1000-3000 yr. Highs and lows in summer insolation during MIS 3 are generally associated with the warmest and coldest intervals. Warm periods at Little Lake correlate with warm sea-surface temperatures in the Santa Barbara Basin. Changes in the strength of the subtropical high and the jet stream may account for synchronous changes at the two sites. During MIS 2, shifts between mesic and xeric subalpine forests suggest changes in precipitation every 1000-3000 yr. Increases in Tsuga heterophylla pollen at 25,000 and 22,000 cal yr B.P. imply brief warmings. Minimum summer insolation and maximum global ice-volumes during MIS 2 correspond to cold and dry conditions. Fluctuations in precipitation at Little Lake do not correlate with changes in the Santa Barbara Basin and may be explained by variations in the strength of the glacial anticyclone and the position of the jet stream. ?? 2001 University of Washington.

Building Resilience into Sitka Spruce (Picea sitchensis (Bong. Carr. Forests in Scotland in Response to the Threat of Climate Change

Directory of Open Access Journals (Sweden)

Andrew D. Cameron

2015-02-01

Full Text Available It is expected that a warming climate will have an impact on the future productivity of European spruce forests. In Scotland, Sitka spruce (Picea sitchensis (Bong. Carr. dominates the commercial forestry sector and there is growing pressure to develop alternative management strategies to limit potential economic losses through climate change. This review considers management options to increase the resilience of Sitka spruce dominated forests in Scotland. Given the considerable uncertainty over the potential long-term impacts of climate change, it is recommended that Sitka spruce should continue to be planted where it already grows well. However, new planting and restocking should be established in mixtures where silviculturally practicable, even if no-thin regimes are adopted, to spread future risks of damage. Three potentially compatible species with Sitka spruce are western hemlock (Tsuga heterophylla (Raf. Sarg., grand fir (Abies grandis (Lamb. Lindl. and Douglas fir (Pseudotsuga menziesii (Mirb. Franco and all form natural mixtures in its native range in North America. The predicted windier climate will require a range of management inputs, such as early cutting of extraction racks and early selective thinning, to improve stability. The potential to improve resilience to particularly abiotic damage through transforming even-aged stands into irregular structures and limiting the overall size of the growing stock is discussed.

Global diversity of the Ganoderma lucidum complex (Ganodermataceae, Polyporales) inferred from morphology and multilocus phylogeny.

Science.gov (United States)

Zhou, Li-Wei; Cao, Yun; Wu, Sheng-Hua; Vlasák, Josef; Li, De-Wei; Li, Meng-Jie; Dai, Yu-Cheng

2015-06-01

Species of the Ganoderma lucidum complex are used in many types of health products. However, the taxonomy of this complex has long been chaotic, thus limiting its uses. In the present study, 32 collections of the complex from Asia, Europe and North America were analyzed from both morphological and molecular phylogenetic perspectives. The combined dataset, including an outgroup, comprised 33 ITS, 24 tef1α, 24 rpb1 and 21 rpb2 sequences, of which 19 ITS, 20 tef1α, 20 rpb1 and 17 rpb2 sequences were newly generated. A total of 13 species of the complex were recovered in the multilocus phylogeny. These 13 species were not strongly supported as a single monophyletic lineage, and were further grouped into three lineages that cannot be defined by their geographic distributions. Clade A comprised Ganoderma curtisii, Ganoderma flexipes, Ganoderma lingzhi, Ganoderma multipileum, Ganoderma resinaceum, Ganoderma sessile, Ganoderma sichuanense and Ganoderma tropicum, Clade B comprised G. lucidum, Ganoderma oregonense and Ganoderma tsugae, and Clade C comprised Ganoderma boninense and Ganoderma zonatum. A dichotomous key to the 13 species is provided, and their key morphological characters from context, pores, cuticle cells and basidiospores are presented in a table. The taxonomic positions of these species are briefly discussed. Noteworthy, the epitypification of G. sichuanense is rejected. Copyright © 2014 Elsevier Ltd. All rights reserved.

Basic principles of scintillation counting; Principes de Base du Comptage par Scintillations; Osnovnye printsipy stsintillyatsij; Principios fundamentales del recuento con aparatos de centelleo

Energy Technology Data Exchange (ETDEWEB)

Johns, H E; Cederlund, J F [Ontario Cancer Institute, Toronto (Canada)

1959-07-01

The effect of the energy of radiation, the crystal size, the collimation of the beam and scattering on the pulse-height distribution produced by monoenergetic radiation will be discussed. These aspects will be related to scintillation scanning. The effects of voltage on the operation of photomultiplier s and so-called plateaus will be dealt with. Glow-transfer tubes for counting will be dealt with and a useful substraction circuit for comparing the counting rate from two separate scintillation counters will be presented. (author) [French] Les auteurs examineront l'effet de l'energie du rayonnement, de la dimension du cristal, de la collimation du faisceau et de la diffusion sur la repartition de l'amplitude des impulsions dues au rayonnement monoenergetique, en rattachant l'etude de ces questions a l'exploration par scintillations. Ils etudieront egalement les effets de la tension sur le fonctionnement des photomultiplicateurs et des , ainsi que l'utilisation de pour le comptage; ils presenteront enfin un circuit de soustraction utile servant a comparer le taux de comptage de deux scintillometres distincts. (author) [Spanish] Los autores estudiaran el efecto que la energia de la radiacion, el tamano del cristal, la colimacion del haz y la dispersion ejercen sobre la distribucion de la amplitud de los impulsos debida a la radiacion monoenergetica, relacionando todas estas cuestiones con la exploracion mediante aparatos de centelleo. Examinaran tambien la influencia de las variaciones de tension sobre el funcionamiento de los fotomultiplicadores y sobre las denominadas , asi como los tubos luminiscentes de transmision para el recuento; por ultimo, presentaran un circuito de sustraccion que sirve para comparar el indice de recuento de dos contadores de centelleo distintos. (author) [Russian] Budet obsuzhdat'sya vliyanie ehnergii izlucheniya, velichiny kristalla, kollimirovaniya lucha i, nakonets, rasseyaniya na amplitudnoe

The foliar chemistry dynamic in eastern hemlock and how it relates to the competitive mechanism between two invasive herbivores: Adelges tsugae and Fiorinia externa.

Science.gov (United States)

Mailea R. Miller-Pierce; Evan L. Preisser; Dave A. Orwig

2009-01-01

While invasive species themselves have been examined, little work has addressed the question of competition between two invasive specialists on a shared host. An example of this situation exists in the eastern United States, where...

Risk assessment of imidacloprid use in forest settings on the aquatic macroinvertebrate community.

Science.gov (United States)

Benton, Elizabeth P; Grant, Jerome F; Nichols, Rebecca J; Webster, R Jesse; Schwartz, John S; Bailey, Joseph K

2017-11-01

The isolated effects of a single insecticide can be difficult to assess in natural settings because of the presence of numerous pollutants in many watersheds. Imidacloprid use for suppressing hemlock woolly adelgid, Adelges tsugae (Annand) (Hemiptera: Adelgidae), in forests offers a rare opportunity to assess potential impacts on aquatic macroinvertebrates in relatively pristine landscapes. Aquatic macroinvertebrate communities were assessed in 9 streams in Great Smoky Mountains National Park (southern Appalachian Mountains, USA). The streams flow through hemlock conservation areas where imidacloprid soil drench treatments were applied for hemlock woolly adelgid suppression. Sites were located upstream and downstream of the imidacloprid treatments. Baseline species presence data (pre-imidacloprid treatment) were available from previous sample collections at downstream sites. Downstream and upstream sites did not vary in numerous community measures. Although comparisons of paired upstream and downstream sites showed differences in diversity in 7 streams, higher diversity was found more often in downstream sites. Macroinvertebrate functional feeding groups and life habits were similar between downstream and upstream sites. Downstream and baseline stream samples were similar. While some functional feeding group and life habit species richness categories varied, variations did not indicate poorer quality downstream communities. Imidacloprid treatments applied according to US Environmental Protection Agency federal restrictions did not result in negative effects to aquatic macroinvertebrate communities, which indicates that risks of imidacloprid use in forest settings are low. Environ Toxicol Chem 2017;36:3108-3119. © 2017 SETAC. © 2017 SETAC.

Quantifying the Eocene to Pleistocene topographic evolution of the southwestern Alps, France and Italy

Science.gov (United States)

Fauquette, Séverine; Bernet, Matthias; Suc, Jean-Pierre; Grosjean, Anne-Sabine; Guillot, Stéphane; van der Beek, Peter; Jourdan, Sébastien; Popescu, Speranta-Maria; Jiménez-Moreno, Gonzalo; Bertini, Adele; Pittet, Bernard; Tricart, Pierre; Dumont, Thierry; Schwartz, Stéphane; Zheng, Zhuo; Roche, Emile; Pavia, Giulio; Gardien, Véronique

2015-02-01

We evaluate the topographic evolution of the southwestern Alps using Eocene to Pleistocene pollen data combined with existing sedimentological, petrographic and detrital geo- and thermochronological data. We report 32 new pollen analyses from 10 sites completed by an existing dataset of 83 samples from 14 localities situated across the southwestern Alps, including both the pro- and the retro-foreland basins. The presence of microthermic tree pollen (mainly Abies, Picea) indicates that this part of the mountain belt attained elevations over 1900 m as early as the Oligocene. Inferred rapid surface uplift during the mid-Oligocene coincided with a previously documented brief phase of rapid erosional exhumation, when maximum erosion rates may have reached values of up to 1.5-2 km/Myr. Slower long-term average exhumation rates of ∼0.3 km/Myr since the Late Oligocene helped maintaining the high Alpine topography of the southwestern Alps until today. The relative abundances of meso-microthermic tree pollen (Cathaya, Cedrus and Tsuga) and microthermic tree pollen (Abies, Picea) in the pro- and retro-foreland basin deposits, indicate that the present-day asymmetric topography, with a relatively gentle western flank and steeper eastern flank, was established early in the southwestern Alps, at least since the Early Miocene, and possibly since the Oligocene or Late Eocene. Therefore, the high topography and asymmetric morphology of this part of the Alps has been maintained throughout the past ∼30 Ma.

Technique of forecasting the working capacity of horizontal p-n-p transistor for a given radiation level; Metodika prognozirovaniya rabotosposobnosti gorizontal`nogo p-n-p tranzistora na zadannyj uroven` izlucheniya

Energy Technology Data Exchange (ETDEWEB)

Pershenkov, V S; Sevast` yanov, A V

1994-12-31

Methods of forecasting the degradation of horizontal p-n-p transistors under the effect of ionizing radiation based on the principles of invariant topological approach are presented. Results are presented and analysis of experimental investigations into the real test structures performed in the same process cycle as the integral circuit under development is given.

Examining Wetland Frequency Discrepancies Produced by Data Collected at Wetland Boundaries and across the Landscape: Using Tsuga canadensis (L.) Carr. (Eastern Hemlock) as a Case Study

Science.gov (United States)

2017-08-01

Continental Canada. The Bryologist 98:218–227. Wiens, J. A. 1989. Spatial Scaling in Ecology . Functional Ecology 3:385–397. REPORT DOCUMENTATION...EPA U.S. Environmental Protection Agency FAC Facultative FACU Facultative Upland FACW Facultative Wetland FWS U.S. Fish and Wildlife Service...National and Regional Panel members from four cooperat- ing federal agencies: the Corps, the U.S. Environmental Protection Agency (EPA), the U.S. Fish and

Plant recolonization in the Himalaya from the southeastern Qinghai-Tibetan Plateau: Geographical isolation contributed to high population differentiation.

Science.gov (United States)

Cun, Yu-Zhi; Wang, Xiao-Quan

2010-09-01

The Himalaya-Hengduan Mountains region (HHM) in the southern and southeastern Qinghai-Tibetan Plateau (QTP) is considered an important reservoir and a differentiation center for temperate and alpine plants in the Cenozoic. To reveal how plants responded to the Quaternary climatic oscillations in the QTP, the phylogeographical histories of a few subalpine and alpine plants have been investigated, but nearly all studies used only uniparentally inherited cytoplasmic DNA markers, and only a couple of them included sampling from the Himalaya. In this study, range-wide genetic variation of the Himalayan hemlock (Tsuga dumosa), an important forest species in the HHM, was surveyed using DNA markers from three genomes. All markers revealed genetic depauperation in the Himalaya and richness in the Hengduan Mountains populations. Surprisingly, population differentiation of this wind-pollinated conifer is very high in all three genomes, with few common and many private nuclear gene alleles. These results, together with fossil evidence, clearly indicate that T. dumosa recolonized the Himalaya from the Hengduan Mountains before the Last Glacial Maximum (LGM), accompanied with strong founder effects, and the influence of the earlier glaciations on demographic histories of the QTP plants could be much stronger than that of the LGM. The strong population differentiation in T. dumosa could be attributed to restricted gene flow caused by the complicated topography in the HHM that formed during the uplift of the QTP, and thus sheds lights on the importance of geographical isolation in the development of high plant species diversity in this biodiversity hotspot. Copyright 2010 Elsevier Inc. All rights reserved.

Development and testing of a snow interceptometer to quantify canopy water storage and interception processes in the rain/snow transition zone of the North Cascades, Washington, USA

Science.gov (United States)

Martin, Kael A.; Van Stan, John T.; Dickerson-Lange, Susan E.; Lutz, James A.; Berman, Jeffrey W.; Gersonde, Rolf; Lundquist, Jessica D.

2013-06-01

Tree canopy snow interception is a significant hydrological process, capable of removing up to 60% of snow from the ground snowpack. Our understanding of canopy interception has been limited by our ability to measure whole canopy water storage in an undisturbed forest setting. This study presents a relatively inexpensive technique for directly measuring snow canopy water storage using an interceptometer, adapted from Friesen et al. (2008). The interceptometer is composed of four linear motion position sensors distributed evenly around the tree trunk. We incorporate a trunk laser-mapping installation method for precise sensor placement to reduce signal error due to sensor misalignment. Through calibration techniques, the amount of canopy snow required to produce the measured displacements can be calculated. We demonstrate instrument performance on a western hemlock (Tsuga heterophylla) for a snow interception event in November 2011. We find a snow capture efficiency of 83 ± 15% of accumulated ground snowfall with a maximum storage capacity of 50 ± 8 mm snow water equivalent (SWE). The observed interception event is compared to simulated interception, represented by the variable infiltration capacity (VIC) hydrologic model. The model generally underreported interception magnitude by 33% using a leaf area index (LAI) of 5 and 16% using an LAI of 10. The interceptometer captured intrastorm accumulation and melt rates up to 3 and 0.75 mm SWE h-1, respectively, which the model failed to represent. While further implementation and validation is necessary, our preliminary results indicate that forest interception magnitude may be underestimated in maritime areas.

Influence of ionizing radiation on synthesis and molecular heterogeneity of catalase in tissue culture of Rauwolfia serpentina; Vliyanie ioniziruyushchego izlucheniya na biosintez i molekulyarnuyu geterogennost' katalazy v kul'ture tkani Rauwolfia serpentina

Energy Technology Data Exchange (ETDEWEB)

Komov, V P; Bespalova, E V; Strelkova, M A [Sankt-Peterburgskaya Khimiko-Farmatsevticheskaya Akademiya, Kafedra Biologii, S.-Peterburg (Russian Federation)

1998-12-01

Changes in activity and molecular heterogeneity of catalase in tissue culture of Rauwolfia serpentina following irradiation in early growth period at the doses of 8 and 50 Gy has been studied. Ionizing radiation accelerate the synthesis and degradation rates of catalase and total protein. A comparative study of changes in enzyme and protein turnover during growth on irradiated and non-irradiated medium has been made.

Plants promote mating and dispersal of the human pathogenic fungus Cryptococcus.

Directory of Open Access Journals (Sweden)

Deborah J Springer

Full Text Available Infections due to Cryptococcus are a leading cause of fungal infections worldwide and are acquired as a result of environmental exposure to desiccated yeast or spores. The ability of Cryptococcus to grow, mate, and produce infectious propagules in association with plants is important for the maintenance of the genetic diversity and virulence factors important for infection of animals and humans. In the Western United States and Canada, Cryptococcus has been associated with conifers and tree species other than Eucalyptus; however, to date Cryptococcus has only been studied on live Arabidopsis thaliana, Eucalyptus sp., and Terminalia catappa (almond seedlings. Previous research has demonstrated the ability of Cryptococcus to colonize live plants, leaves, and vasculature. We investigated the ability of Cryptococcus to grow on live seedlings of the angiosperms, A. thaliana, Eucalyptus camaldulensis, Colophospermum mopane, and the gymnosperms, Pseudotsuga menziesii (Douglas fir, and Tsuga heterophylla (Western hemlock. We observed a broad-range ability of Cryptococcus to colonize both traditional infection models as well as newly tested conifer species. Furthermore, C. neoformans, C. deneoformans, C. gattii (VGI, C. deuterogattii (VGII and C. bacillisporus (VGIII were able to colonize live plant leaves and needles but also undergo filamentation and mating on agar seeded with plant materials or in saprobic association with dead plant materials. The ability of Cryptococcus to grow and undergo filamentation and reproduction in saprobic association with both angiosperms and gymnosperms highlights an important role of plant debris in the sexual cycle and exposure to infectious propagules. This study highlights the broad importance of plants (and plant debris as the ecological niche and reservoirs of infectious propagules of Cryptococcus in the environment.

Miocene fossil plants from Bukpyeong Formation of Bukpyeong Basin in Donghae City, Gangwon-do Province, Korea and their palaeoenvironmental implications

Science.gov (United States)

Jeong, Eun Kyoung; Kim, Hyun Joo; Uemura, Kazuhiko; Kim, Kyungsik

2016-04-01

The Tertiary sedimentary basins are distributed along the eastern coast of Korean Peninsula. The northernmost Bukpyeong Basin is located in Donghae City, Gangwon-do Province, Korea. The Bukpyeong Basin consists of Bukpyeong Formation and Dogyeongri Conglomerate in ascending order. The geologic age of Bukpyeong Formation has been suggested as from Early Miocene to Pliocene, In particular, Lee & Jacobs (2010) suggested the age of the Bukpyeong Formation as late Early Miocene to early Middle Miocene based on the fossils of rodent teeth. Sedimentary environment has been thought as mainly fresh water lake and/or swamp partly influenced by marine water. Lately, new outcrops of Bukpyeong Formation were exposed during the road construction and abundant fossil plants were yielded from the newly exposed outcrops. As a result of palaeobotanical studies 47 genera of 23 families have been found. This fossil plant assemblage is composed of gymnosperms and dicotyledons. Gymnosperms were Pinaceae (e.g., Pinus, Tsuga), Sciadopityaceae (e.g., Sciadopitys) and Cupressaceae with well-preserved Metasequoia cones. Dicotyledons were deciduous trees such as Betulaceae (e.g., Alnus, Carpinus) and Sapindaceae (e.g., Acer, Aesculus, Sapindus), and evergreen trees such as evergreen Fagaceae (e.g., Castanopsis, Cyclobalanopsis, Pasania) and Lauraceae (e.g., Cinnamomum, Machilus). In addition, fresh water plants such as Hemitrapa (Lytraceae) and Ceratophyllum (Ceratophyllaceae) were also found. The fossil plant assemblage of the Bukpyeong Formation supported the freshwater environment implied by previous studies. It can be suggested that the palaeoflora of Bukpyeong Formation was oak-laurel forest with broad-leaved evergreen and deciduous trees accompanying commonly by conifers of Pinaceae and Cupressaceae under warm-temperate climate.

Elevated Annual Runoff Ratios in Pacific Northwest Catchments Impacted by Epidemic Foliage Disease of Douglas-fir

Science.gov (United States)

Bladon, K. D.; Bywater-Reyes, S.; LeBoldus, J. M.; Segura, C.; Ritokova, G.; Shaw, D. C.

2017-12-01

Catchments in the Western United States are undergoing unprecedented levels of tree die-off and/or reduced vigor due to increased severity of wildfire, drought, insect outbreaks, and disease. In the U.S. Pacific Northwest, Swiss needle cast (SNC) is the most damaging foliar disease of Douglas-fir (Pseudotsuga menziesii), physically obstructing stomata and preventing CO2 uptake and transpiration. A recent analysis in coastal Oregon indicated a substantial increase in area affected by the disease, from 530.5 km2 in 1996 to 2,387.1 km2 in 2015. Deforestation or reduced tree vigor can have profound impacts on catchment hydrology, in theory, producing increased streamflow due to reduced interception and transpiration. However, these increases have not always been detectable as impacts also depend on factors such as climate and vegetation composition. Moreover, press disturbances, such as insect outbreaks or disease, often do not result in complete removal of understorey or canopy vegetation. We analyzed trends in annual runoff ratios (quotient of discharge divided by precipitation) from 1990-2015 in 12 catchments (183-1,744 km2) in western Oregon. In general, runoff ratios increased by 10-27% in catchments with a total area of SNC >10%, with the most substantial runoff increases in catchments with SNC impacting >25% of the area. Interestingly, the most severely impacted catchment ( 90.5% SNC) showed a decrease in runoff. This is consistent with a potential compensatory response from understory western hemlock (Tsuga heterophylla) trees, a phenomenon observed in the most severely impacted sites. Findings from this study are important for assessing the impacts of biotic forest disturbances on water supply and aquatic ecosystem health.

Survival and development of Lymantria monacha (Lepidoptera: Lymantriidae) on North American and introduced Eurasian tree species.

Science.gov (United States)

Keena, M A

2003-02-01

Lymantria monacha (L.) (Lepidoptera: Lymantriidae), the nun moth, is a Eurasian pest of conifers that has potential for accidental introduction into North America. To project the potential host range of this insect if introduced into North America, survival and development of L. monacha on 26 North American and eight introduced Eurasian tree species were examined. Seven conifer species (Abies concolor, Picea abies, P. glauca, P. pungens, Pinus sylvestris with male cones, P. menziesii variety glance, and Tsuga canadensis) and six broadleaf species (Betula populifolia, Malus x domestica, Prunus serotiaa, Quercus lobata, Q. rubra, and Q. velutina) were suitable for L. monacha survival and development. Eleven of the host species tested were rated as intermediate in suitability, four conifer species (Larix occidentalis, P. nigra, P. ponderosa, P. strobus, and Pseudotsuga menziesii variety menziesii) and six broadleaf species (Carpinus caroliniana, Carya ovata, Fagus grandifolia, Populus grandidentata, Q. alba, and Tilia cordata) and the remaining 10 species tested were rated as poor (Acer rubrum, A. platanoidies, A. saccharum, F. americana, Juniperus virginiana, Larix kaempferi, Liriodendron tulipfera, Morus alba, P. taeda, and P. deltoides). The phenological state of the trees had a major impact on establishment, survival, and development of L. monacha on many of the tree species tested. Several of the deciduous tree species that are suitable for L. monacha also are suitable for L. dispar (L.) and L. mathura Moore. Establishment of L. monacha in North America would be catastrophic because of the large number of economically important tree species on which it can survive and develop, and the ability of mated females to fly and colonize new areas.

Dendrogeomorphic Assessment of the Rattlesnake Gulf Landslide in the Tully Valley, Onondaga County, New York

Science.gov (United States)

Tamulonis, Kathryn L.; Kappel, William M.

2009-01-01

Dendrogeomorphic techniques were used to assess soil movement within the Rattlesnake Gulf landslide in the Tully Valley of central New York during the last century. This landslide is a postglacial, slow-moving earth slide that covers 23 acres and consists primarily of rotated, laminated, glaciolacustrine silt and clay. Sixty-two increment cores were obtained from 30 hemlock (Tsuga canadensis) trees across the active part of the landslide and from 3 control sites to interpret the soil-displacement history. Annual growth rings were measured and reaction wood was identified to indicate years in which ring growth changed from concentric to eccentric, on the premise that soil movement triggered compensatory growth in displaced trees. These data provided a basis for an 'event index' to identify years of landslide activity over the 108 years of record represented by the oldest trees. Event-index values and total annual precipitation increased during this time, but years with sudden event-index increases did not necessarily correspond to years with above-average precipitation. Multiple-regression and residual-values analyses indicated a possible correlation between precipitation and movement within the landslide and a possible cyclic (decades-long) tree-ring response to displacement within the landslide area from the toe upward to, and possibly beyond, previously formed landslide features. The soil movement is triggered by a sequence of factors that include (1) periods of several months with below-average precipitation followed by persistent above-average precipitation, (2) the attendant increase in streamflow, which erodes the landslide toe and results in an upslope propagation of slumping, and (3) the harvesting of mature trees within this landslide during the last century and continuing to the present.

Incorporating interspecific competition into species-distribution mapping by upward scaling of small-scale model projections to the landscape.

Directory of Open Access Journals (Sweden)

Mark Baah-Acheamfour

Full Text Available There are a number of overarching questions and debate in the scientific community concerning the importance of biotic interactions in species distribution models at large spatial scales. In this paper, we present a framework for revising the potential distribution of tree species native to the Western Ecoregion of Nova Scotia, Canada, by integrating the long-term effects of interspecific competition into an existing abiotic-factor-based definition of potential species distribution (PSD. The PSD model is developed by combining spatially explicit data of individualistic species' response to normalized incident photosynthetically active radiation, soil water content, and growing degree days. A revised PSD model adds biomass output simulated over a 100-year timeframe with a robust forest gap model and scaled up to the landscape using a forestland classification technique. To demonstrate the method, we applied the calculation to the natural range of 16 target tree species as found in 1,240 provincial forest-inventory plots. The revised PSD model, with the long-term effects of interspecific competition accounted for, predicted that eastern hemlock (Tsuga canadensis, American beech (Fagus grandifolia, white birch (Betula papyrifera, red oak (Quercus rubra, sugar maple (Acer saccharum, and trembling aspen (Populus tremuloides would experience a significant decline in their original distribution compared with balsam fir (Abies balsamea, black spruce (Picea mariana, red spruce (Picea rubens, red maple (Acer rubrum L., and yellow birch (Betula alleghaniensis. True model accuracy improved from 64.2% with original PSD evaluations to 81.7% with revised PSD. Kappa statistics slightly increased from 0.26 (fair to 0.41 (moderate for original and revised PSDs, respectively.

Recognizing Non-Stationary Climate Response in Tree Growth for Southern Coastal Alaska, USA

Science.gov (United States)

Wiles, G. C.; Jarvis, S. K.; D'Arrigo, R.; Vargo, L. J.; Appleton, S. N.

2012-12-01

Stationarity in growth response of trees to climate over time is assumed in dendroclimatic studies. Recent studies of Alaskan yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach) have identified warming-induced early loss of insulating snowpack and frost damage as a mechanism that can lead to decline in tree growth, which for this species is documented over the last century. A similar stress may be put on temperature-sensitive mountain hemlock (Tsuga mertensiana (Bong.) Carrière) trees at low elevations, which in some cases show a decline in tree growth with warming temperatures. One of the challenges of using tree-ring based SAT, SST, PDO and PNA-related reconstructions for southern coastal Alaska has been understanding the response of tree-ring chronologies to the warming temperatures over the past 50 years. Comparisons of tree growth with long meteorological records from Sitka Alaska that extend back to 1830 suggest many mountain hemlock sites at low elevations are showing decreasing ring-widths, at mid elevations most sites show a steady increasing growth tracking warming, and at treeline a release is documented. The recognition of this recent divergence or decoupling of tree-ring and temperature trends allows for divergence-free temperature reconstructions using trees from moderate elevations. These reconstructions now provide a better perspective for comparing recent warming to Medieval warming and a better understanding of forest dynamics as biomes shift in response to the transition from the Little Ice Age to contemporary warming. Reconstructed temperatures are consistent with well-established, entirely independent tree-ring dated ice advances of land-terminating glaciers along the Gulf of Alaska providing an additional check for stationarity in the reconstructed interval.

Universal energy-dispersive EXAFS spectrometer based on SR beam of `Kurchatovskij Institute` and scientific program of investigations; Universal`nyj ehnergodispersionnyj EXAFS-spektrometr v Natsional`nom tsentre sinkhrotronnogo izlucheniya (`Kurchatovskij institut`) i nauchnaya programma issledovanij

Energy Technology Data Exchange (ETDEWEB)

Aksenov, V L; Ivanov, I N [Laboratory of Particle Physics, Joint Institute for Nuclear Research, Dubna (Russian Federation); Koval` chuk, M V [Institut Kristallografii, RAN, Moscow (Russian Federation); and others

1997-12-31

The scheme of the energy-dispersive EXAFS spectrometer is discussed. The spectrometer will be used for the solid state investigations on the Kurchatov Synchrotron Radiation Source KSRS. The main elements of the universal station are described, including the results of the positive-sensitive X-ray detector testing. The experimental investigations are presented which are supposed to be carried out with this EXAFS spectrometer. (author). 4 refs., 14 figs., 1 tab. Submitted to Poverkhnost`. Rentgenovskie, Sinkhrotronnye i Nejtronnye Issledovaniya.

Determination on Mice and other Organisms of the RBE of High-Energy Protons and Electrons; Efficacite Biologique Relative sur la Souris et d'Autres Organismes des Protons et des Electrons De Haute Energie; Opredelenie obeh pri obluchenii myshej i drugikh organizmov protonami i ehlektronami vysokikh ehnergij; Determinacion de la Eficacia Biologica Relativa de los Protones y de los Electrones de Elevada Emergia en el Raton y en Otros Organismos

Energy Technology Data Exchange (ETDEWEB)

Bonet-Maury, P.; Baarli, J.; Kahn, T.; Dardenne, G.; Frilley, M.; Deysine, A. [Institut du Radium, Paris (France)

1964-03-15

{sub 50}, supervivencia media, reduccion del timo y de los testiculos) es proxima a 1; esta EBR corresponde al valor medio de la transferencia lineal de energia (TLE) de las particulas y, en el caso de los protones, no parece que sufra aumento alguno por efecto del valor local mas elevado del TLE de las 'estrellas' de espalacion. (author) [Russian] Izuchalis' obshhie jeffekty pri obluchenii myshej letal'nymi dozami protonov s jenergiej 157 i 592 Mjev i jelektronov s jenergiej 150 i 950 Mjev. {gamma} obluchennyh zhivotnyh nabljudalis te zhe obshhie simptomy, chto i posle rentgenovskogo i gamma-obluchenija. S pomoshh'ju primenennyh biologicheskih testov ne bylo o b naruzheno nikakih fenomenov, specifichnyh dlja chastic vysokih jenergij. Ustanovlennaja po chetyrem pokazateljam OBJe (LD-50, srednjaja vyzhivaemost', umen'shenie zobnoj zhelezy i semennikov) malo otklonjaetsja ot 1 ; jeta OBJe so o tvetstvue t srednej LPE chastic, i dlja protonov ne kazhetsja uvelichennoj za schet povyshenija mestnogo LPE zvezd raspada. (author). (author)

Mobile carbohydrates in Himalayan treeline trees I. Evidence for carbon gain limitation but not for growth limitation.

Science.gov (United States)

Li, Mai-He; Xiao, Wen-Fa; Wang, San-Gen; Cheng, Gen-Wei; Cherubini, Paolo; Cai, Xaio-Hu; Liu, Xing-Liang; Wang, Xiao-Dan; Zhu, Wan-Ze

2008-08-01

To test whether the altitudinal distribution of trees is determined by a carbon shortage or an insufficient sugar fraction (sugar:starch ratio) in treeline trees, we studied the status of nonstructural carbohydrates (NSC) and their components (total soluble sugars and starch) in Abies fabri (Mast.) Craib and Picea balfouriana var. hirtella Rehd. et Wils. trees along three elevational gradients, ranging from lower elevations to the alpine treeline, on the eastern edge of the Tibetan Plateau. For comparison, we investigated a low-altitude species (Tsuga yunnanensis (Franch.) Pritz.) which served as a warm-climate reference because it is distributed in closed montane forests below 3100 m a.s.l. in the study area. The carbon status of T. yunnanensis responded to altitude differently from that of the treeline species. At the species level, total NSC was not consistently more abundant in treeline trees than in trees of the same species growing at lower elevations. Thus there was no consistent evidence for carbon limitation of growth in treeline trees. For the three treeline species studied (P. balfouriana and A. fabri in the Kang-Ding Valley and A. fabri in the Mo-Xi Valley), winter NSC concentrations in treeline trees were significantly lower than in lower-elevation trees of the same species, suggesting that, in winter, carbon is limited in treeline trees. However, in no case was there total overwinter depletion of NSC or its components in treeline trees. Treeline and low-altitude species had similar sugar:starch ratios of about three at their upper-elevational limits in April. We conclude that survival and growth of trees at the elevational or latitudinal climate limit depend not only on NSC concentration in perennial tissues, but also on the maintenance of an overwintering sugar:starch ratio greater than three.

Broadening the ecological context of ungulate-ecosystem interactions: the importance of space, seasonality, and nitrogen.

Science.gov (United States)

Murray, Bryan D; Webster, Christopher R; Bump, Joseph K

2013-06-01

Spatial heterogeneity of soil resources, particularly nitrogen availability, affects herbaceous-layer cover and diversity in temperate forest ecosystems. Current hypotheses predict that ungulate herbivores influence nitrogen availability at the stand scale, but how ungulates affect nitrogen availability at finer spatial scales that are relevant to the herb layer is less understood. We tested the hypothesis that ungulate exclusion reduces the spatial complexity of nitrogen availability at neighborhood scales (1-26 m) apart from mean stand scale effects. This outcome was expected due to a lack of ungulate nitrogenous waste deposition within exclosures and seasonally variable ungulate habitat use. To test this hypothesis we examined spatial patterning of ammonium and nitrate availability, herb-layer cover and diversity, and under-canopy solar radiation using geostatistical models. Our study sites included six stands of eastern hemlock (Tsuga canadensis) forest: three where white-tailed deer (Odocoileus virginianus) were excluded and three that were accessible to deer. Where deer were present, patch sizes of ammonium availability, cover, and diversity were smaller compared to deer exclosures, whereas mean site-level effects were not significant. Within deer exclosures cover and solar radiation were more similar in patch size than were cover and nitrogen availability. Our results suggest that browsing ungulates affect spatial patterns of herb-layer cover and diversity through the excretion of nitrogenous wastes in small, discrete patches. Ungulate-excreted nitrogen deposition and herbivory were concentrated in the dormant season, allowing herb-layer plants a greater opportunity to benefit from nitrogen additions. Therefore, the impact of ungulates on nitrogen cycling in forest ecosystems varies with spatial scale and the seasonal timing of ungulate impacts. In this way, ungulates may function as a seasonally dependent link between fine-scale and landscape

Effects of dams and geomorphic context on riparian forests of the Elwha River, Washington

Science.gov (United States)

Shafroth, Patrick B.; Perry, Laura G; Rose, Chanoane A; Braatne, Jeffrey H

2016-01-01

Understanding how dams affect the shifting habitat mosaic of river bottomlands is key for protecting the many ecological functions and related goods and services that riparian forests provide and for informing approaches to riparian ecosystem restoration. We examined the downstream effects of two large dams on patterns of forest composition, structure, and dynamics within different geomorphic contexts and compared them to upstream reference conditions along the Elwha River, Washington, USA. Patterns of riparian vegetation in river segments downstream of the dams were driven largely by channel and bottomland geomorphic responses to a dramatically reduced sediment supply. The river segment upstream of both dams was the most geomorphically dynamic, whereas the segment between the dams was the least dynamic due to substantial channel armoring, and the segment downstream of both dams was intermediate due to some local sediment supply. These geomorphic differences were linked to altered characteristics of the shifting habitat mosaic, including older forest age structure and fewer young Populus balsamifera subsp. trichocarpa stands in the relatively static segment between the dams compared to more extensive early-successional forests (dominated by Alnus rubra and Salix spp.) and pioneer seedling recruitment upstream of the dams. Species composition of later-successional forest communities varied among river segments as well, with greater Pseudotsuga menziesii and Tsuga heterophylla abundance upstream of both dams, Acer spp. abundance between the dams, and P. balsamifera subsp. trichocarpa and Thuja plicata abundance below both dams. Riparian forest responses to the recent removal of the two dams on the Elwha River will depend largely on channel and geomorphic adjustments to the release, transport, and deposition of the large volume of sediment formerly stored in the reservoirs, together with changes in large wood dynamics.

Windthrow and salvage logging in an old-growth hemlock-northern hardwoods forest

Science.gov (United States)

Lang, K.D.; Schulte, L.A.; Guntenspergen, G.R.

2009-01-01

Although the initial response to salvage (also known as, post-disturbance or sanitary) logging is known to vary among system components, little is known about longer term forest recovery. We examine forest overstory, understory, soil, and microtopographic response 25 years after a 1977 severe wind disturbance on the Flambeau River State Forest in Wisconsin, USA, a portion of which was salvage logged. Within this former old-growth hemlock-northern hardwoods forest, tree dominance has shifted from Eastern hemlock (Tsuga canadensis) to broad-leaf deciduous species (Ulmus americana, Acer saccharum, Tilia americana, Populus tremuloides, and Betula alleghaniensis) in both the salvaged and unsalvaged areas. While the biological legacies of pre-disturbance seedlings, saplings, and mature trees were initially more abundant in the unsalvaged area, regeneration through root suckers and stump sprouts was common in both areas. After 25 years, tree basal area, sapling density, shrub layer density, and seedling cover had converged between unsalvaged and salvaged areas. In contrast, understory herb communities differed between salvaged and unsalvaged forest, with salvaged forest containing significantly higher understory herb richness and cover, and greater dominance of species benefiting from disturbance, especially Solidago species. Soil bulk density, pH, organic carbon content, and organic nitrogen content were also significantly higher in the salvaged area. The structural legacy of tip-up microtopography remains more pronounced in the unsalvaged area, with significantly taller tip-up mounds and deeper pits. Mosses and some forest herbs, including Athyrium filix-femina and Hydrophyllum virginianum, showed strong positive responses to this tip-up microrelief, highlighting the importance of these structural legacies for understory biodiversity. In sum, although the pathways of recovery differed, this forest appeared to be as resilient to the compound disturbances of windthrow

Determination of parameters of the Gummel-Pun model of bipolar transistors with account of Kirk effect and ionizing radiation effects; Opredelenie parametrov modeli Gummelya-Puna bipolyarnykh tranzistiorov s uchetom ehffekta Kirka i vozdejstviya ioniziruyushchego izlucheniya

Energy Technology Data Exchange (ETDEWEB)

Ragozin, A Yu [and others

1994-12-31

Gamma radiation effect on the parameters Gummel-Pun model n-p-n transistors with different resistance of the collector layer is investigated. A method for their determination on the base of vol-ampere characteristics is proposed.

Calculation of comparators of analog-to-digital converters with account of electric regime of transistor operation and ionizing radiation effect; Raschet komparatov analogo-tsifrovykh preobrazovatelej s uchetom ehlektricheskogo rezhima raboty tranzistorov i vozdejstviya ioniziruyushchego izlucheniya

Energy Technology Data Exchange (ETDEWEB)

Ragozin, A Yu

1994-12-31

Zero shift voltage in comparators of analog-to-digital converters under gamma irradiation with regard to electric mode effect on bipolar transistor degradation is calculated. It is shown that the input range of comparators such weak units are represented by comparators of bipolar and lower grades.

Separation of Graphitic Line in Debyegram of the Reactor Graphite; Separation de la raie graphitique dans le debyegramme du graphite nucleaire; Otdelenie linii grafita v debaiegramme reaktornogo grafita; Separacion de la linea grafitica en el diagrama de debye del grafito nuclear

Energy Technology Data Exchange (ETDEWEB)

Pandic, B. [Institut Rudjer Boskovio, Zagreb, Yugoslavia (Croatia)

1963-11-15

apertura quedan eliminados todos los errores excepto el de absorcion en las muestras, que se corrige matematicamente. Estos perfiles corregidos permiten separar analiticamente las lineas de difraccion de alto grado de simetria de las fases grafitica y no grafitica. El error de medicion de la amplitud media de estas lineas es inferior a 5%. (author) [Russian] Razrabotan metod opredeleniya srednego razmera L{sub c} kristallitov reaktornogo grafita. Metod osnovan na matematicheskoj korrektsii (002) difraktsionnogo kontura, poluchennogo na diffraktometre Filshsa so stsintillyatsionnym schetchikom. Obsuzhdayutsya preimushchestva izlucheniya CuK{sub {beta}} pered dubletom CuK{sub {alpha}}. Vybor sootvetstvuyushchikh shchelej pozvolil ustranit' vse pogreshnosti pribora, za isklyucheniem oshibki, vyzvannoj pogloshcheniem v obraztse, na kotoruyu delalas' popravka matematicheskim sposobom. Yasnye i vpolne simmetrichnye diffraktsionnye linii grafitnoj i negrafitnoj fazy ispravlennogo takim obrazom kontura legko razlichaemy. Ehksperimental'naya oshibka opredeleniya polushiriny ehtikh linij ne prevyshaet 5%. (author)

Application of Nuclear Radiation to Textile Materials and Processes. Radiation-induced graft copolymerization of vinyl monomers and fibrous polymers; Applications des rayonnements aux textiles. Formation radiochimique de copolymeres ''greffes'' par l'action de monomeres vinyliques sur des polymeres en fibre; Primenenie yadernogo izlucheniya v tekstil'noj promyshlennosti. Obrazovanie privitykh sopolimerov iz vinilovykh monomerov i voloknistykh polimerov pod dejstviem izlucheniya; Aplicaciones de las radiaciones nucleares a los procesos y materiales textiles. Copolimerizacion por injerto radioinducida de monomeros vinilicos y de polimeros fibrosos

Energy Technology Data Exchange (ETDEWEB)

Armstrong, Jr., A. A.; Rutherford, H. A. [University of North Carolina at Raleigh, NC (United States)

1963-11-15

A technique has been developed that permits the radiation grafting of volatile vinyl monomers to fibrous polymers in a uniform manner. It involves the addition of the organic compound from the vapour phase, and the process may be done by either a mutual or a pre-irradiation process using cobalt-60. Systems that accelerate the rate of graft copolymerization have been studied, and it is possible to add significant amounts of several of the monomers without radiation damage to the fibre substrate. The fibrous materials that are relatively unstable toward radiation are the ones that add the vinyl compounds the most readily. These are the celluloses, celluloseesters, polyamides, and polypropylene. The addition of the monomer to the fibre substrate apparently takes place by a free-radical mechanism and, as already indicated above, it is possible to irradiate the material first and subsequently obtain grafting by exposure of the irradiated material to the monomer vapour. Attempts have been made to determine the life of the free-radicals and while it has been difficult to obtain exact figures, it has been demonstrated that they may continue to exist in some fibres for15 to 20 hr after irradiation, even at room temperature. Preliminary experimental evidence has also suggested that the diffusion time of the monomer to free-radical sites in post-irradiation grafting proceeds at different rates in the different fibres. The modification of cotton by the addition of polyacrylonitrile results in a fibre almost completely resistant to micro-organisms. Only 3.5% deposition is required and the material retains the appearance and feel of untreated cotton. The product is superior to that made by the addition of acrylonitrile using the ironperoxide catalyst system. Polypropylene may be grafted with several different monomers to produce a fibre that is dyeable by commonly-used dyeing procedures. At the present stage of development, however, the wash fastness of the grafted and dyed materials is not good enough for commercial acceptance. The strength of cellulose acetate yam, as well as the modulus, can be materially increased by the addition of polyacrylonitrile. Other monomers do not behave in this manner. There is some indication that the fibre may be improved with one compound, especially with respect to its behaviour in the wet state. Fibre modification by the procedure described might be practical commercially if techniques that will increase the rate of diffusion of the monomer into the fibre structure can be developed. (author) [French] Les auteurs ont mis au point une methode qui permet de realiser par les rayonnements un greffage homogene de monomeres vinyliques volatils sur des polymeres en fibres. Elle consiste a ajouter le compose organique en phase vapeur; on procede, soit par irradiation de l'ensemble, soit par irradiation prealable des polymeres, aux rayons du cobalt-60. Les auteurs ont etudie des systemes qui accelerent la formation des copolymeres ''greffes''; ils ont constate qu'il est possible d'ajouter des quantites significatives de plusieurs des monomeres sans qu'il en resulte de dommages radioinduits dans le substrat fibreux. Les polymeres en fibres relativement instables en presence des rayonnements sont ceux qui fixent le plus facilement les composes vinyliques. C'est le cas des matieres cellulosiques, des esters de cellulose, des polyamides et du polypropylene. Le monomere s'ajoute au substrat fibreux par un mecanisme de radicaux libres, et, comme on l'a indique plus haut, on peut irradier d'abord les polymeres et ensuite provoquer le greffage par exposition de la matiere irradiee S la vapeur du monomere. On a tente de determiner la duree de vie des radicaux libres; il est difficile de donner des chiffres exacts, mais on a demontre qu'ils peuvent subsister dans certaines fibres 15 a 20 heures apres l'irradiation, meme a la temperature ambiante. Des resultats experimentaux preliminaires donnent egalement a penser que le temps de diffusion du monomere vers les sites des radicaux libres au cours du greffage apres irradiation prealable varie selon la nature des fibres. En traitant la fibre de coton par du polyacrylonitrile, on obtient une fibre ayant une resistance aux micro-organismes presque absolue. Un depot de 3,5% suffit et le tissu conserve l'apparence et la consistance de coton non traite. Ce produit est superieur a celui que l'on obtient par traitement a l'acrylonitrile en utilisant du peroxyde de fer comme catalyseur. Sur le polypropylene, on peut ''greffer'' plusieurs monomeres differents et obtenir une fibre susceptible d'etre teinte par les procedes courants. Mais en l'etat actuel des recherches, les tissus ainsi greffes et teints ne sont pas encore assez solides au lavage, pour une production industrielle. La resistance d'un fil d'acetate de cellulose ainsi que son module d'elasticite peuvent etre nettement augmentes par l'addition de polyacrylonitrile. D'autres monomeres ne se component pas de la meme facon. On a des raisons de penser que la fibre peut etre amelioree avec un certain compose, notamment en ce qui concerne sa resistance a l'etat humide. Les fibres modifiees par les procedes qui viennent d'etre decrits seraient susceptibles d'etre produites industriellement si l'on pouvait mettre au point des methodes permettant d'accelerer la diffusion du monomere dans la structure de la fibre. (author) [Spanish] Los autores describen un procedimiento nuevo que permite radioinjertar homogeneamente monomeros vinueicos volatiles en polimeros fibrosos. El proceso entrana la adicion del compuesto organico en la fase vapor, y puede llevarse a cabo de una manera simultanea o mediante una irradiacion previa, utilizando {sup 60}Co. Se han estudiado sistemas que aceleran la velocidad de copolimerizacion por injerto, y se ha comprobado que es posible adicionar cantidades significativas de varios monomeros sin que el substrato de la fibra resulte danado por la irradiacion. Los materiales fibrosos que son relativamente inestables frente a las radiaciones son los que con mayor facilidad adicionan los compuestos vinflicos. Esos materiales son los celulosicos, los esteres de celulosa, las poliamidas y el polipropileno. La adicion del monomero al substrato fibroso tiene lugar, al parecer, por accion de radicales libres y, como ya se ha indicado, es posible irradiar primero el material y conseguir despues el injerto exponiendo el material irradiado al vapor del monomero. Se ha procurado determinar la vida de los radicales libres, y aunque ha resultado dificil obtener cifras exactas, se ha podido comprobar que pueden subsistir en algunas fibras por espacio de 15 a 20 h despues de la irradiacion, incluso a la temperatura ambiente. Las pruebas experimentales parecen indicar tambien que el tiempo de difusion del monomero en los puntos correspondientes a los radicales libres, en el injerto subsiguiente a la irradiacion, varia segun la fibra. El algodon modificado por adicion de poliacrilonitrilo constituye una fibra que presenta una resistencia casi perfecta a la accion de los microorganismos. Solo se precisa un deposito de un 3,5% y el material conserva el aspecto y el tacto del algodon no tratado. El producto obtenido es de calidad superior al que se consigue con la adicion de acrilonitrilo en presencia de peroxido de hierro como catalizador. El polipropeno puede ser injertado en distintos monomeros, dando una fibra que puede ser teSida por los procedimientos usuales. No obstante, por el momento la solidez al lavado de los materiales injertados y tenidos no es satisfactoria para un producto comercial. La resistencia del hilo de acetato de celulosa, asi como su modulo de elasticidad pueden incrementarse por adicion de poliacrilonitrilo, pero otros monomeros no dan resultados comparables. Existen indicios de que la calidad de la fibra puede ser mejorada mediante un compuesto, en particular por lo que se refiere a su resistencia en estado humedo. Los autores estiman que la modificacion de las propiedades de la fibra mediante el procedimiento descrito podria aprovecharse en el terreno comerical de encontrarse procedimientos que permitan aumentar la velocidad de difusion del monomero en la estructura de la fibra. (author) [Russian] Razrabotana standartnaya metodika radiatsionnoj privivki letuchikh vinilovykh monomerov k voloknistym polimeram. Ehta metodika sostoit v vvedenii organicheskogo soedineniya v parovoj faze; protsess osushchestvlyaetsya ili putem odnovremennogo oblucheniya ili predvaritel'nym oblucheniem ot istochnika Co''6''0. Issledovany sistemy, povyshayushchie skorost' privitoj sopolimeriehatsii. Ustanovleno, chto mozhno vvodit' znachitel'nye kolichestva nekotorykh monomerov, ne vyzyvaya radiatsionnogo povrezhdeniya voloknistogo substrata. Imenno te voloknistye materialy, kotorye sravnitel'no neustojchivo reagiruyut na radiatsiyu naibolee legko prisoedinyayut vinilovye soedineniya. K takim materialam otnosyatsya tsellyulozy, slozhnye ehfiry tsellyulozy, poliamidy i polipropilen. Prisoedinenie monomera k voloknistomu substratu, ochevidno, proiskhodit po svobodno-radikal'nomu mekhanizmu, i, kak uzhe ukazyvalos' vyshe, mozhno snachala obluchit' volokno a zatem provodit' privivku, podvergaya obluchennyj material vozdejstviyu parov mono- mera. Predprinimalis' popytki vyyasnit' dlitel'nost' sushchestvovaniya svobodnykh radikalov i, khotya dovol'no trudno poluchit' tochnye dannye, bylo pokazano, chto svobodnye radikaly prodolzhayut sokhranyat'sya v nekotorykh voloknakh spustya 15 - 20 chasov posle oblucheniya, dazhe pri komnatnoj temperature. Predvaritel'nye opytnye dannye takzhe navodyat na mysl' o tom,chto pri posleradiatsionnom privivanii monomer diffundiruet k svobodno-radikal'nym tsentram s razlichnymi skorostyami v raznykh voloknakh. Volokno khlopka, modifitsirovannoe vvedeniem v ego sostav poliakrilonitrila, ustojchivo k dejstviyu mikroorganizmov. Vvedenie 3,5%-nogo poliakrilonitrila pozvolyaet materialu sokhranyat' vneshnij vid i grif, kak u neobrabotannogo khlopka. Po svoim svojstvam ehtot produkt luchshe produkta, poluchennogo vvedeniem akrilonitrila i primeneniem kataliehatsionnoj sistemy zhelezo - perekis'. K polipropilenu mozhno privit' ryad razlichnykh monomerov, poluchaya volokna, kotorye mozhno okrashivat', primenyaya standartnye metody okraski. Tem ne menee na nastoyashchej stadii razrabotki prochnost' privitykh i okrashennykh materialov vo vlazhnom sostoyanii eshche nedostatochno vysoka, chtoby mozhno bylo ehti materialy pustit' v proizvodstvo. Krepost' atsetattsellyuloznoj pryazhi, takzhe kak i ee modul' uprugosti, mozhno zametno povysit' vvedeniem poliakrilonitrila. Drugie monomery vedut sebya inache. Imeyutsya nekotorye ukazaniya na to, chto kachestvo volokna mozhno uluchshit', vvedya v ego sostav opredelennoe soedinenie, osobenno ehto otnositsya k svojstvam volokna vo vlazhnom sostoyanii. Modifikatsiya volokon sposobom, opisannym vyshe, mozhet stat' ehkonomicheski vygodnoj, esli budet razrabotana metodika, pozvolyayushchaya uvelichit' skorost' diffuzii monomera v voloknistuyu strukturu. (author)

Change of electric parameters of power cables for nuclear installations under separated and combined effect of radiation and humidity; Izmenenie ehlektricheskikh parametrov silovykh kabelej dlya yadernykh ustano vok pri razdel`nom i sovmestnom vozdejstvii izlucheniya i povyshennoj vlazhnosti

Energy Technology Data Exchange (ETDEWEB)

Filatov, N I

1994-12-31

Results of an experimental investigation into the changes of insulation resistance, capacitance and tangent of force cable dielectric loss angle under separate and combined action of gamma radiation and increased humidity of the environment are presented.

Holocene temperature variability revealed by brGDGTs in subtropical southwestern China

Science.gov (United States)

Feng, X.; Zhao, C.

2017-12-01

Subtropical areas are important source region of moisture and heat in global climate system. Paleoclimate reconstructions from these regions, especially quantitative records, would not only help to better understand the nature of climate system through time, but also provide important constraining dataset for long-term ecosystem variations in these ecological important areas. To date, quantitative climate records with reliable chronological controls are still limited from terrestrial archives in subtropical areas. Here we present a 50-year-resolution quantitative temperature record throughout the Holocene based on branched GDGTs at a small alpine lake, Tiancai Lake (26°38'E, 99°43'N, 3898 m.a.s.l) in southwestern China. The record is based on a temporal calibration between instrumental mean annual air temperature (MAAT) and brGDGT compounds (GDGT-IIIa, GDGT-IIa', GDGT-IIb, GDGT-Ia and GDGT-Ic). The MAAT was relatively low -0.6 ° between 11 and 7.5 ka, then abruptly increased 1 ° to 4 °until 7 ka. The MAAT was relatively warm 2° between 7 and 1 ka, then decreased to 1° over the last 1 ka. The Middle to Late Holocene was 3 ° warmer than the Early Holocene. The MAAT variation at Lake Tiancai is supported by changes in evergreen oaks and Tsuga from the same sediment core, suggesting that the growth of cold-tolerant forest in place of subtropical evergreen broadleaved forest has been driven by the decrease in MAAT. The early Holocene cold interval revealed by our record and pollen data is different with the chironomid-based summer temperature reconstruction from the same lake, the latter has been driven by summer insolation. This difference suggests that a pronounced winter contribution to the mean annual temperature during the early Holocene, which was probably caused by a low winter insolation, and strengthened by a sparse vegetation cover and influences of winter ice/snow cover in tropical high latitude regions.

Vegetation change and pollen geochronology from the Atlantic Coast of the United States during the last Millennium

Science.gov (United States)

Christie, M.; Bernhardt, C. E.; Clear, J.; Corbett, D. R.; Horton, B.

2017-12-01

Vegetation changes related to anthropogenic and climatic change have been reconstructed at many locations. Synthesizing observations from multiple locations improves our understanding of the regionality of these impacts and drivers. Human alterations to the plant communities vary spatially in timing and impact. For example, deforestation occurred at different times, rates, and magnitudes along the Atlantic Coast of the United States, while of the introduction of non-native plants into ecosystems varies by region. Gradual climate shifts cause the appearance of migration in sensitive plants, so climate-related transitions can be traced from one location to another. Here, we combine new and published pollen data from Florida to Connecticut to produce a regional synthesis of vegetation changes for the last 1000 years. We have produced detailed reconstructions of vegetation changes in response to anthropogenic and climatic forcing. Our database contains pollen assemblages from more than 10 locations along the Atlantic coast of the United States, including new reconstructions from the Florida Keys, Delaware Estuary, and northern New Jersey. All pollen assemblages are placed in a geochronological framework with as fine as decadal resolution using composite chronologies of radiocarbon, pollution histories and cesium isotopes. Anthropogenic impacts, including deforestation from European settlement and the introduction of non-native plants, are observed in the pollen record and serve as useful markers of time. For example, the abrupt increase in Ambrosia pollen in the mid-Atlantic corresponds to 18th Century deforestation. Climate transitions that can be seen in the pollen record during the last millennium include the Medieval Climate Optimum, Little Ice Age, and human-induced warming following industrialization in the 20th century. Plant communities of the United States Atlantic Coast adapted to the evolving climate. For example, Picea and Tsuga are indicative of cooler

Late Miocene (Pannonian) Vegetation from the Northern Part of Central Paratethys

Science.gov (United States)

Kováčová, M.; Doláková, N.

2009-04-01

During Late Miocene, the Western Carpathian paleogeography started to change. The Lake Pannon retreated southwards, and the northern coast of the back arc basin was slightly elevated due to progradation of deltaic and alluvial facies, especially in the lowlands. The studied „Pannonian lake" sediments come from the Czech and Slovak parts of Central Paratethys. Changes of the sedimentary environment from deep to shallow lake and deltaic environment, followed by development of alluvial plains were noticed. Salinity crisis due to Paratethys isolation led to development of total freshwater environment to the end of this period. Samples from 3 surficial localities and 15 boreholes were palynologically studied. Occasional occurences of Dinoflagellates indicate a slightly higher salinity, whereas green algae Pediastrum, aquatic ferns Azolla, and aquatic and coastal plants (Nelumbo, Nymphaea, Myriophyllum, Sparganium, Potamogeton, Cyperaceae etc.) represent a freshwater environment. Due to paleogeographic changes and climatic oscillations the number of thermophilous taxa decreased and some of them disappeared completely from this area (f. e. Sapotaceae, Palmae). Mostly broad-leaved deciduous elements of mixed mesophytic forests (Quercus, Celtis, Carya, Tilia, Carpinus, Betula, Juglans) with some thermophilous elements admixture of Engelhardia, Castanea, Trigonobalanopsis, Symplocos, Cornaceaepollis satzveyensis generally dominate. Variously high relief of the uplifted mountainy chains created ideal conditions for higher presence of extrazonal vegetation (Cedrus, Tsuga, Picea, Cathaya) in the investigated area. Zonal type of vegetation including marshes, riparian forests with Alnus, Salix, Pterocarya, Liquidambar, Betula, Fraxinus, shrubs and lianas on dryer substrates associated riparian forest (Buxus, Ericaceae, Vitaceae, Lonicera, Rosaceae type Rubus), and coastal swamps with Taxodiaceae, Nyssa, Myrica, Sciadopitys were growing in the floodplain lowlands of Vienna Basin

Holocene Paleohydrological Changes in Northern Michigan: Interpretations of Biomarker Distributions and Compound Specific Stable Isotope Analysis from Peatlands

Science.gov (United States)

Nichols, J. E.; Booth, R. K.; Jackson, S. T.; Pendall, E. G.; Huang, Y.

2006-12-01

Sediments of ombrotrophic peatlands are excellent archives for reconstructing past changes in precipitation/evaporation (P/E) balance. Multiproxy analysis of these sediments is critical for better understanding of climatic events experienced by these highly sensitive systems, as each proxy may respond to different climate parameters. In this study, we use distributions of n-alkanes and δD of Sphagnum biomarkers to interpret paleohydrology from sediments of Irwin Smith Bog, northern Michigan. We then integrate these data with pollen data and testate amoebae-inferred water table depth. Sphagnum moss is the dominant peat former in ombrotrophic bogs, but vascular plants become abundant when water tables are drawn down. Thus, the abundance of Sphagnum relative to vascular plants is indicative of peatland hydrology. The n-alkanes produced by Sphagnum differ from vascular plants in the relative abundance of the different homologues, with the former having excess amounts of shorter chain C23 n-alkane. We use several measures (compound ratios, PCA) to show changes in then-alkane distributions in the sediments, and thus changes in the peatland plant community. Our data provide high- resolution, quantitative paleohydrological records for the study region that are consistent with other records. We also show that the relative abundance of a newly identified Sphagnum biomarker, 2-heptacosanone, can be used to reconstruct changing plant communities. Because ombrotrophic systems lose water by evaporation, drier/warmer conditions cause hydrogen isotopic enrichment of bog water and Sphagnum biomarkers. We measured the δD of C23 n-alkane and 2-heptacosanone to provide additional paleoclimate information. Our multiproxy approach allows us to better understand the climate changes during key intervals of the Holocene. For example, a sharp decrease in the abundance of Tsuga canadensis (hemlock) pollen has been previously identified in records from many places throughout eastern North

Reinvestigation of the Miocene palynoflora from the Daotaiqiao Formation of north-eastern China using SEM

Science.gov (United States)

Akyurt, Elvan; Grímsson, Friðgeir; Zetter, Reinhard; Leng, Qin; Bouchal, Johannes Martin

2016-04-01

Here we report the first results of an ongoing study on the Miocene palynoflora from the Daotaiqiao Formation of north-eastern China. Using the single grain technique, we examined individual pollen and spores using both light and scanning electron microscopy. A previous study by Grímsson et al. (2012) on Onagraceae pollen grains from this locality, using the same technique identified five different species. Such a variety of Onagraceae from a single palynoflora is unknown elsewhere. The ongoing study suggests a remarkably rich pollen and spore flora with at least 15 different types of spores, one Ginkgo and one Ephedra type pollen, 11 conifer pollen types and approximately 145 angiosperm pollen types. Spores are very rare in the samples (≤1%). Conifer pollen grains are regularly observed but are not a dominant component (ca. 16 %). The samples yield a high quantity and diversity of angiosperm pollen (ca. 80%). The conifers include representatives of Cupressaceae (2 spp.), Pinaceae (Larix, Picea, Pinus, Tsuga) and Sciadopityaceae. The angiosperm pollen cover at least 40 families. Prominent elements are pollen of the Betulaceae (Alnus, Betula, Carpinus, Corylus), Cercidiphyllaceae (Cercidiphyllum), Ericaceae (8 spp.), Eucommiaceae (Eucommia), Fagaceae (Fagus, Quercus spp., Castaneoideae), Juglandaceae (Carya, Cyclocarya, Juglans, Pterocarya), Rosaceae (11 spp.), Sapindaceae (Acer, Aesculus) and Ulmaceae (Hemiptelia, Ulmus, Zelkova). The high angiosperm pollen diversity indicates a varying landscape with a relatively high variety of niches including riparian, dry and mesic forests. Most of the potential modern analogues of the fossil taxa are currently thriving under humid temperate (Cfa- and Cwa)-climates, pointing to paleoclimate conditions not unlike those found today in the lowlands and adjacent mountain regions of the (south-) eastern United States, the humid-meridional region of western Eurasia, and central and southern China, and Honshu (Japan). References

Grafting to Polymethylmethacrylate by the Radiation-Peroxidation Method; Greffage sur le polymethacrylate de methyle par la methode de la radioperoxydation radiochimique; Privivanie k polimetilmetakripatu po metodu radiatsionnogo peroksidirovaniya; Injertos en el polimetilmetacrilato por el metodo de peroxidacion radioinducida

Energy Technology Data Exchange (ETDEWEB)

Kircher, J. F.; Markle, R. A.; Lieberman, R.; Sleimers, F. A.; Leininger, R. I. [Batelle Memorial Institute, Columbus, OH (United States)

1963-11-15

e injerta con mayor facilidad que un polimero de peso molecular relativamente elevado. Se observa tambien que al elevar la temperatura hasta alcanzar al punto de transicion de la fase vidriosa aumenta el grado de peroxidacion y de injerto. Los autores proponen una explicacion de los resultados, basada en los efectos de la temperatura y del peso molecular sobre la movilidad del polimero y de los radicales. (author) [Russian] Issledovano radiatsionnoe okislenie polimetilmetakrilata (RMMA) v perekisnoe soedinenie v svyazi s posleduyushchim privivaniem pirrolidonvinila k perekisnomu polimeru. Peroksidirovanie issledovano v zavisimosti ot velichiny dozy, molekulyarnogo vesa RMMA i temperatury izlucheniya. Pokazano, chto RMMA s malym molekulyarnym vesom bolee ehffektivno okislyaetsya do perekisi i privivaetsya pri obluchenii dozami v neskol'ko megarad, chem polimer so sravnitel'no bol'shim molekulyarnym vesom. Otmecheno takzhe, chto povyshenie temperatury primerno do temperatury perekhoda stekla v zhidkoe sostoyanie intensifitsiruet protsessy okisleniya do perekisej i privivaniya. Rezul'taty ob{sup y}asneny, iskhodya iz vliyaniya temperatury i molekulyarnogo vesa na podvizhnost' polimera i oskolochnye radikaly. (author)

On the Conversion of UF{sub 6} to UO{sub 2}; Conversion de UF{sub 6} en UO{sub 2}; O prevrashchenii UF{sub 6} v UO{sub 2}; Transformacion del UF{sub 6} en UO{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Kolar, D.; Slivnik, J.; Volavsek, B. [Jozef Stefan Nuclear Institute, Ljubljana, Yugoslavia (Slovenia)

1963-11-15

reduccion del hexafluoruro de uranio con amoniaco en fase gaseosa a 40 deg. C. Mediante una pirohidrolisis con vapor de agua e hidrogeno entre 500 y 600 deg. C, transformaron en dioxido de uranio el producto de grano muy fino retenido en precipitadores electricos. Por analisis termodiferencial y termogravimetrico observaron el desarrollo de la reaccion. Determinaron el fluor y el oxigeno contenidos en el dioxido de uranio y examinaron su estructura cristalina por analisis roentgenografico. Evaluaron diversas caracteristicas fisicoquimicas tales como el area superficial especifica, las dimensiones de las particulas y la densidad del polvo vibrado. A partir del polvo, prepararon pastillas prensadas y sinterizadas a 1350 deg. C. Obtuvieron densidades, variables segun las diversas condiciones de preparacion, que alcanzaron hasta el 94% del valor teorico. (author) [Russian] Vosstanovleniem geksaftorida urana ammiakom v gazovoj faze pri 40 deg. C byl poluchen kompleksnyj ammonij ftorid urana. Ehtot melkij poroshok uderzhivalsya v ehlektroosaditelyakh i perevodilsya v dvuokis' urana metodom pirogidrolieha vodyanymi parami i vodorodom pri temperature ot 500 do 600 deg. C. Khod reaktsii kontrolirovalsya metodom termicheskogo i termogravimetricheskogo analizov. V dvuokisi urana analiticheski opredelyalos' soderzhanie ftora i kisloroda, a kristallicheskaya struktura proveryalas' metodom rentgenovskogo analiza. Opredeleny nekotorye fiziko- khimicheskie' kharakteristiki , kak udel'naya poverkhnost', razmer chastits i konechnaya plotnost' poroshka. Iz poroshka pressovalis' tabletki, kotorye spekalis' pri 1350 deg. C. V zavisimosti ot razlichnykh uslovij izgotovleniya byli dostignuty plotnosti do 94% teoreticheskoj. (author)

Twentieth-century decline of large-diameter trees in Yosemite National Park, California, USA

Science.gov (United States)

Lutz, J.A.; van Wagtendonk, J.W.; Franklin, J.F.

2009-01-01

Studies of forest change in western North America often focus on increased densities of small-diameter trees rather than on changes in the large tree component. Large trees generally have lower rates of mortality than small trees and are more resilient to climate change, but these assumptions have rarely been examined in long-term studies. We combined data from 655 historical (1932-1936) and 210 modern (1988-1999) vegetation plots to examine changes in density of large-diameter trees in Yosemite National Park (3027 km2). We tested the assumption of stability for large-diameter trees, as both individual species and communities of large-diameter trees. Between the 1930s and 1990s, large-diameter tree density in Yosemite declined 24%. Although the decrease was apparent in all forest types, declines were greatest in subalpine and upper montane forests (57.0% of park area), and least in lower montane forests (15.3% of park area). Large-diameter tree densities of 11 species declined while only 3 species increased. Four general patterns emerged: (1) Pinus albicaulis, Quercus chrysolepis, and Quercus kelloggii had increases in density of large-diameter trees occur throughout their ranges; (2) Pinus jeffreyi, Pinus lambertiana, and Pinus ponderosa, had disproportionately larger decreases in large-diameter tree densities in lower-elevation portions of their ranges; (3) Abies concolor and Pinus contorta, had approximately uniform decreases in large-diameter trees throughout their elevational ranges; and (4) Abies magnifica, Calocedrus decurrens, Juniperus occidentalis, Pinus monticola, Pseudotsuga menziesii, and Tsuga mertensiana displayed little or no change in large-diameter tree densities. In Pinus ponderosa-Calocedrus decurrens forests, modern large-diameter tree densities were equivalent whether or not plots had burned since 1936. However, in unburned plots, the large-diameter trees were predominantly A. concolor, C. decurrens, and Q. chrysolepis, whereas P. ponderosa

Copolymerization of Ethylene Induced by Cobalt-60 Gamma Radiation; Copolymerisation de l'ethylene induite par des rayons gamma du cobalt-60; Sopolimerizatsiya ehtilena pod dejstviem gamma-izlucheniya ot istochnika ks'yali-60; Copolimerizacion del etileno inducida por las radiaciones gamma del cobalto-60

Energy Technology Data Exchange (ETDEWEB)

Steinberg, M.; Colombo, P. [Brookhaven National Laboratory, Long Island, NY (United States)

1963-11-15

The gamma radiation initiated copolymerization of ethylene with a number of different monomers was studied at 20{sup o}C and initial pressures up to 680 atm. The experiments were conducted statically in two-phase systems with the exception of the ethylene-carbon monoxide system. Isolation of the copolymers was effected by solvent extraction and fractional precipitation techniques. Infra-red spectroscopy was used for identification. The composition was determined by elemental analysis. A partial evaluation of some of the reaction products including crystalline melting points, densities, solubility characteristics, and molecular weights are given. Evidence of ethylene copolymerization was established with each of the following monomers: styrene, methyl methacrylate, vinyl acetate, acrylonitrile, allyl acetate, isobutylene, chlorotrifluoroethylene, trans 2-butene, methyl acrylate, isoprene, propylene, vinyl chloride, 1-butene, cis 2-butene, carbon monoxide, vinyl pyrrolidone, methyl vinyl ketone, and divinyl benzene. The experimental data obtained in the study of the ethylene-carbon monoxide system were found to obey a linear form of the copolymer composition equation. The ratio of specific rate constants for carbon monoxide and ethylene ({alpha}) was found to have a value of 22.0, indicating that carbon monoxide as a monomer, is activated to the extent that it adds 22 times as fast as an ethylene monomer to an ethylene free-radical chain end. Explosive decomposition was observed to occur during irradiation of ethylene arid chlorotrifluoroethylene under certain irradiation conditions. There is an indication that a threshold radiation intensity exists which induces this violent reaction. The unique advantage of cobalt-60 gamma radiation is that it can be used to induce and control ethylene copolymerization reactions at low temperatures. (author) [French] La copolymerisation de l'ethylene avec divers monomeres provoquee avec des rayons gamma a ete etudiee a 20{sup o}C et a des pressions initiales allant jusqu'a 680 atm. On a procede aux experiences, en milieu statique, dans des systemes a deux phases, a l'exception du systeme ethylene-oxyde de carbone. La separation des copolymeres a ete obtenue par des methodes d'extraction par solvant et de precipitation fractionnee. L'identification a ete faite au moyen de la spectroscopic aux infrarouges. La composition a ete determinee par analyse elementaire. Les auteurs donnent une evaluation partielle de certains produits de la reaction, y compris les points de fusion cristalline, les densites, les caracteristiques de solubilite et les poids moleculaires. La copolymerisation de l'ethylene a ete etablie avec chacun des monomeres suivants : styrene, methacrylate de methyle, acetate de vinyle, acrylonitrile, acetate d'allyle, isobutylene, chlorotiifluoroethylene, transbutene-2, acrylate de methyle, isoprene, propylene, chlorure de vinyle, butene-1, cis-butene-2, oxyde de carbone, pyrrolidone de vinyle, methyle- vinyle-cetone et divinyle-benzene. Les auteurs ont trouve que les donnees experimentales obtenues dans l'etude du systeme ethylene-oxyde de carbone suivaient une forme lineaire de l'equation de composition du copolymere. Pour le rapport {alpha} des constantes de vitesse specifiques de l'oxyde de carbone et de l'ethylene, ils ont determine la valeur 22,0, ce qui montre que l'oxyde de carbone en tant que monomere est active a tel point qu'il se fixe a l'extremite d'une chaftie de radicaux libres d'ethylene 22 fois plus vite que ne le fait un monomere d'ethylene. (author) [Spanish] Los autores estudiaron la copolimerizacion del etileno, inducida por las radiaciones gamma, con una serie de diversos monometos, a 20{sup o}C y presiones iniciales de hasta 680 atm. Los experimentos se llevaron a cabo estaticamente en sistemas bifasicos, salvo en el caso del etileno-oxido de carbono. La separacion de los copolimeros se llevo a cabo por extraccion mediante disolventes y por precipitacion fraccionada. La identificacion se efectuo por espectroscopia infrarroja y la composicion se determino por analisis elemental. Para algunos de los productos de reaccion, los autores indican los puntos de fusion cristalinos, las densidades, las caracteristicas de solubilidad y los pesos moleculares. Obtuvieron pruebas de la copolimerizacion del etileno con cada uno de los siguientes monomeros: estireno, metacrilato de metilo, acetato de vinilo, acrilonitrilo, acetato de alilo, isobuteno, clorotrifluoretileno, trans 2-buteno, acrilato de metilo, isopreno, propeno, cloruro de vinilo, 1-buteno, cis 2-buteno, oxido de carbono, vinilpirrolidona, metilvinilcetona y divinilbenceno. Comprobaron que los datos experimentales obtenidos en el estudio del sistema etileno-oxido de carbono responden a una forma lineal de la ecuacion de composicion del copolimero. Encontraron el valor 22,0 para la razon ({alpha}) de las constantes de velocidad especificas correspondientes al oxido de carbono y al etileno, respectivamente, lo que indica que en calidad de monomero el oxido de carbono se activa en tal medida que se fija al extremo de una cadena de radical etilenico libre con una velocidad 22 veces mayor que un monomero etilenico. (author) [Russian] Byla izuchen vyzvannaya gamma-izlucheniem sopolimerizatsiya ehtilena s ryadom razlichnykh monomerov pri temperature 20{sup o}C i pri nachal'nykh davleniyakh do 680 atm. Ehksperimenty provodilis' staticheski v dvukhfaznykh sistemakh, za isklyucheniem sistemy ehtilen-okis' ugleroda. Razdelenie sopolimerov proizvodilos' metodami ehkstraktsii rastvoritelem i fraktsionirovannogo osazhdeniya. Dlya identifikatsii ispol'zovali infrakrasnuyu spektroskopiyu, a dlya opredeleniya sostava - ehlementarnyj analiz. Privedeny kharakte- ristiki nekotorykh produktov reaktsii, vklyuchayushchie ikh temperaturu plavleniya, plotnost', rastvorimost' i molekulyarnyj ves. Ustanovlena sopolimerizatsiya ehtilena s kazhdym iz sleduyushchikh monomerov: stirolom, metilmetakrilatom, venilatsetatom, akrilonitrilom, allilatsetatom, izobutilenom, khlorotriftoroehtilenom, trans-2-butenom, metilakrilatom, izoprenom, propilenom, khloristym vinilom, 1-butenom, tsis-2-butenom, okis'yu ugleroda, vinilpirrolidonom, metilvinilketonom i divinilbenzolom. Ustanovleno, chto dannye,-poluchennye ehksperimental'nym putem pri izuchenii, sistemy ehtilen-okis' ugleroda, udovletvoryayut linejnoj forme uravneniya sostava sopolimera. Ustanovleno, chto otnoshenie konstant udel'nykh skorostej dlya okisi ugleroda i ehtilena ({alpha}) sostavlyaet 22,0, chto oznachaet, chto okis' uglerode kak monomer aktivirovana v takop stepeni, chto ona prisoedinyaetsya k kontsu tsepochki svobodnykh radikalov ehtilena v 22 raza bystree chem ehtilenovyj monomer. (author)

Use of Neutron Irradiations in the Brookhaven Mutations Programme; Irradiation Neutronique dans le Cadre du Programme de Mutations Radioinduites de Brookhaven; Primenenie nejtronnogo izlucheniya v brukkhejvenskoj programme po ispol'zovaniyu mutatsij; La Irradiacion Neutronica en el Marco del Programa de Mutaciones Radioinducidas de Brookhaven

Energy Technology Data Exchange (ETDEWEB)

Miksche, J. P.; Shapiro, S. [Biology Department, Brookhaven National Laboratory, Upton, NY (United States)

1964-03-15

The Co-operative Radiation-Mutations Programme was established at Brookhaven National Laboratory approximately ten years ago to enable plant breeders and agriculturalists to make use of irradiation techniques in plant improvement programmes. The radiation facilities used in the programme are the thermal neutron column at the BGRR reactor, the 250-kVp X-ray machine in the Biology Department, the kilocurie gamma-sources in the Nuclear Engineering Department, a 12 c Co{sup 60} gamma-source in the greenhouse, and a 4000 c Co{sup 60} source located in a 13-acre field. The development of facilities, techniques, and theory represent Brookhaven's role in this cooperative project whereas the plant material and seed are provided by agricultural experts who are responsible for growing the irradiated material and screening for mutations. More than 150 scientists in 45 states and Puerto Rico are availing themselves of the programme's facilities. Projects have also initiated with Australia, Belgium, Chile, Costa Rica, Denmark, Ecuador, Formosa, Greece, Guatemala, India, Ireland, Italy, Japan, Kenya, Mexico, the Netherlands, Pakistan, Peru, the Philippines, Romania, South Africa.Thailand, Venezuela, West Germany and Yugoslavia. A review of the above cc-operative projects is presented with emphasis on the use of neutrons in mutation induction. (author) [French] Le programme commun de mutations radioinduites a ete mis en oeuvre, il y a une dizaine d'annees, au Laboratoire national de Brookhaven pour permettre aux phytogeneticiens et aux agronomes d'ameliorer les cultures a l 'aide des rayonnements. Les installations utilisees dans le cadre de ce programme sont les suivantes: colonne thermique du reacteur BGRR, appareil a rayons X de 250 kV-crete du Departement de biologie, sources de rayons gamma de 1000 c du Departement du genie nucleaire, source au {sup 60}Co de 12 c dans la serre et source au {sup 60}Co de 4000 c dans un champ experimental de 5 ha. Le role du Laboratoire deBrookhaven consiste a fournir les installations, a elaborer des methodes de travail-et a proceder a des etudes theoriques; les plantes et les semences sont fournies par les experts, qui sont charges de surveiller la croissance des plantes irradiees et d'etudier les mutations. Plus de 150 specialistes, venus de 45 Etats et de Porto-Rico, travaillent dans le cadre du programme. Des projets ont ete mis en oeuvre avec des specialistes des pays ciapres: Afrique du Sud, Allemagne occidentale, Australie, Belgique, Chili, Costa Rica, Danemark, Equateur, Formose, Grece, Guatemala, Inde, Irlande, Italie, Japon, Kenya, Mexique, Pakistan, Pays-Bas, Perou, Philippines, Roumanie, Thailande, Venezuela, et Yougoslavie. Les auteurs exposent brievement les projets communs, en decrivant notamment l'emploi des neutrons pour provoquer des mutations. (author) [Spanish] La ejecucion del programa cooperativo de mutaciones radioinducidas se inicio have unos diez aflos en el Brookhaven National Laboratory a fin de permitir a los fitogenetistas y agronomos de mejorar los cultivos con ayuda de las tecnicas de irradiacion. Las instalaciones utilizadas en el cumplimiento del programa cooperativo son las siguientes: la columna termica del reactor BGRR, el aparato de rayos X de 250 kVp del Departamento de Biologia, las fuentes de rayos gamma del orden del kilocurie del Departamento de Ingenieria Nuclear, una fuente de rayos gamma de {sup 60}Co o de 12 c instalada en el invernadero y una fuente de {sup 60}Co de 4000 c situada en un terreno experimental de 5 ha. La funcion del Laboratorio de Brookhaven consiste en proporcionar las instalaciones, elaborar metodos de trabajo y proceder a estudios teoricos, mientras que las plantas y semillas son facilitadas por los agronomos que estan encargados del cultivo de las plantas irradiadas y de la seleccion de las mutaciones. Mas de 150 especialistas de 45 Estados y de Puerto Rico recurren a los servicios ofrecidos por el programa. Tambien se han emprendido proyectos en colaboracion con expertos de Australia, Belgica, Costa Rica, Chile, Dinamarca, Ecuador, Formosa, Grecia, Guatemala, India, Irlanda, Italia, japon, Kenia, Mexico, Paises Bajos, Pakistan, Peru, Filipinas, Rumania, Sudafrica, Tailandia, Venezuela, Alemania Occidental y Yugoeslavia. Los autores presentaran una resefla de los proyectos precitados, deteniendose ante todo en el uso de los neutrones para inducir mutaciones. EBR, por ejemplo, la capacidad de restablecimiento y la manifestacion del efecto oxigeno, principalmente para dosis correspondientes a valores reducidos de la TLE. Si bien esta interpretacion debe considerarse provisional, la distribucion de la dosis en funcion de la TLE proporciona una base para la realizacion de nuevos experimentos sobre la relacion existente entre la EBR y la TLE. (author) [Russian] Programma sotrudnichestva po ispol'zovaniju radiomutacij byla razrabotana v Brukhejvenskoj nacional'noj laboratorii primerno desjat' let nazad, chtoby predostavit' vozmozhnost' rastenievodam i agronomam primenjat' metody obluchenija po programme uluchshenija sortov rastenija. V kachestve ustanovki dlja obluchenija po programme ispol'zovalis' teplovaja kolonna v Brukhejvenskom grafitovom jeksperimental'nom reaktore, rentgenovskij apparat (pikovoe naprjazhenie 250 kv) biologicheskogo otdela jadernoj tehniki, gamma-istochnik moshhnost'ju 12 kjuri v teplicah i istochnik Co{sup 60}, raspolozhennyj v pole ploshhad'ju 13 akrov. V jetoj programme sotrudnichestva na dolju Brukhejvenskoj laboratorii prihoditsja razrabotka oborudovanija metodov i teoreticheskih polozhenij, v to vremja kak rastitel'nyj material i semena predostavljajutsja jekspertami po sel'skomu hozjajstvu, o t vetstvennymi za vyrashhivanie obluchennogo materiala i otbor mutacij. Bo le e 150 uchenyh iz 45 shtatov i Pujerto-Riko uchastvujut v vypolnenii programmy. Nachato takzhe vypolnenie proektov s Avstraliej, Bel'giej, Chili, Ko sta'Rika, Daniej, Jekvadorom, Tajvanem, Greciej, G vatem a loj, Indiej, Iralandiej, Italiej, Japoniej, Keniej, Niderlandami, Pakistanom, Peru, Filippinami, Rumyniej, Juzhnoj Afrikoj, Tailandom, Venesujeloj, Zapadnoj Germaniej i Jugoslaviej. Predstavlen obzor ukazannyh proektov sotrudnichestva, osoboe vnimanie udeljaetsja ispol'zovaniju nejtronov dlja poluchenija mutacij. (author)

The Effects of Gamma Radiation on the Ovaries of Dacus Oleae Gmel; Effet des rayons gamma sur les ovaires de la Dacus Oleae Gmel; Vozdejstvie gamma-izlucheniya na yaichniki Dacus Oleae; Efecto de las radiaciones gamma sobre los ovarios de la Dacus Oleae Gmel

Energy Technology Data Exchange (ETDEWEB)

Baccetti, Baccio [Agricultural Entomology Station, Florence and Raffaella de Dominicis Radiological Institute, University of Florence (Italy)

1963-09-15

The authors have studied by cytological and ultramicroscopio techniques the ovaries of unfertilized adult females of Dacus oleae irradiated in the middle period of the pupal stage with several doses (2-30 kr) of gamma rays. In all cases the treatment inhibits the normal development of the ovary. Nurse cells and egg cells are very small and few in number and show abnormal stricture and ultrastructure, particularly as regards the cytoplasmic organelles. (author) [French] Les auteurs ont fait appel aux techniques cytologiques et ultramicroscopiques pour etudier les ovaires de femelles adultes de Dacus oleae non fecondees, qui avaient ete irradiees au milieu du stade pupaire par plusieurs doses (2-30 kr) de rayons gamma. Dans tous les cas, l'irradiation a empeche un developpement normal de l'ovaire. Les cellules nourricieres et les ovules etaient tres petits et rares, avec une structure anormale, surtout pour les organites du cytoplasme. (author) [Spanish] Los autores de la memoria han estudiado con tecnicas citologicas y ultramicroscopicas los ovarios de hembras adultas, no fertilizadas, de la Dacus oleae irradiadas durante el periodo medio de la fase ninfal con varias dosis de rayos gamma (de 2 a 30 kr). El tratamiento inhibe el desarrollo normal del ovario. Los oocitos, en todas sus fases, son muy pequenos, aparecen en escaso numero y muestran una estructura y ultraestructuca anormales, sobre todo por lo que respecta a los organulos citoplasmicos. (author) [Russian] Avtory izuchili s pomoshch'yu tsitologicheskikh i ul'tramikroskopicheskikh metodov yaichniki neollodotvorennykh khenskikh osobej Dacus oleae, obluchennykh, v seredine fazy okuklivaniya razlichnymi dozami (ot 2000 do 30 000 r) gamma-luchej. V kazhdom sluchae ehto tormozilo normal'noe razvitie yaichnikov. Pitayushchie i yajtsevye kletki byli ochen' malen'kimi, kolichestvo ikh neznachitel'no, struktura i ul'trastruktura nenormal'nye, prezhde vsego v otnoshenii. (author)

Some Problems of Calculation and Design of High-Activity Gamma Units; Quelques aspects du calcul et de l'etablissement de projets d'installations puissantes emettrices de rayonnement gamma; Nekotorye voprosy rascheta i proektirovaniya moshchnykh gamma-ustanovok; Algunos aspectos del calculo y construccion de instalaciones de irradiacion gamma de elevada intensidad

Energy Technology Data Exchange (ETDEWEB)

Bibergal, A V; Leshchinsky, N I; Margulis, U Ya; Khrushev, V G [Academy of Sciences of the USSR, Moscow, Union of Soviet Socialist Republics (Russian Federation)

1960-07-15

radiatsionnogo vozdejstviya (koehffitsient ispol'zovaniya izlucheniya, ravnomernost' doznogo polya i dr.). Privodyatsya nekotorye ratsional'nye skhemy zashchity, uproshchayushchie protsess oblucheniya i metody perezaryadki ustanovok, a takzhe udeshevlyayushchie konstruktsiyu i ehkspluatatsiyu ustanovok. (author)

Magnox Fuel Cycles; Cycles des combustibles gaines de magnox; Toplivnye tsikly magnoks; Ciclos de combustible magnox

Energy Technology Data Exchange (ETDEWEB)

Johnson, A. [United Kingdom Atomic Energy Authority, Risley, Warrington, Lancs (United Kingdom)

1963-10-15

esquemas de irradiacion que se producen segun los diversos programas de carga del combustible, y describe someramente los metodos de calculo utilizados en la actualidad. Compara diversos programas de carga continua o intermitente del combustible. Estudia el problema de la irradiacion eficiente de la primera carga, junto con los metodos de reabastecimiento retardado y de transposicion de los elementos combustibles. Discute las ventajas economicas y los problemas que plantea la utilizacion de uranio, no natural en reactores de flujo nivelado. Formula consideraciones de orden practico sobre la carga de combustible durante la marcha en reactores nuevos y hace referencia a la experiencia adquirida en Bradwell y en Berkeley. Describe someramente el efecto que ejercen las variaciones del costo del combustible y de su resistencia sobre los aspectos economicos del ciclo de combustible. (author) [Russian] Rassmatrivaetsya vzaim o zavisimost' mezhdu potokom izlucheniya i temperaturnym raspredeleniem i kharakteristikami oblucheniya, vyzvannaya razlichnoj praktikoj zameny topliva, opisyvayutsya sushchestvuyushchie metody rascheta. Provoditsya sravnenie razlichnykh skhem zameny topliva, vklyuchaya kak sistemu vygruzki topliva portsiyami, tak i sistemu nepreryvnoj vygruzki. Problema ehffektivnogo oblucheniya pervoj zagruzki rassmatrivaetsya vmeste so skhemami zapazdyvayushchej nachal'noj zameny topliva i ego peremeshcheniya. Rassmatrivayutsya ehkonomicheskie preimushchestva i trudnosti ispol'zovaniya neprirodnogo urana v vyrovnennykh reaktorakh. Rassmatrivaetsya prakticheskoe reshenie skhemy zameny topliva na novykh reaktorakh i delaetsya ssylka na opyt, priobretennyj v Braduehlle i Berkli. Opisyvaetsya vliyani razlichnoj stoimosti topliva i prodolzhitel'nosti kampanii za ehkonomichnost' toplivnogo tsikla. (author)

Extensions of the techniques for the accelerated unspecific isotopic labelling of organic compounds; Applications nouvelles des techniques accelererees du marquage non specifique de composes organiques; Rasprostranenie metodov uskoreniya mecheniya nespetsifichnymi izotopami organicheskikh slozhnykh soedinenij; Nuevas aplicaciones de las tecnicas de marcacion inespecifica acelerada de compuestos organicos

Energy Technology Data Exchange (ETDEWEB)

Ghanem, N A [National Research Centre, El-Dokki, Cairo (Egypt); Westermark, T [Division of Physical Chemistry, Royal Institute of Technology, Stockholm 70 (Sweden)

1962-03-15

marcar, y citar ejemplos en los que este procedimiento se ha empleado con exito. Las diversas tecnicas se basan en el uso de descargas de microondas y de ondas hertzianas, descargas luminiscentes producidas por corriente continua, o alterna, o sencillamente rayos ultravioleta. Se han obtenido cantidades considerables de productos purificados con actividades superiores a 100 mcuries/g. Los tiempos de exposicion a las descargas son del orden de un minuto, y en la mayoria de los casos se observo poca descomposicion. Los autores calcularon el rendimiento energetico alcanzado en estos metodos de marcacion y lo comparan con el correspondiente a las radiaciones ionizantes empleadas por Wilzbach y otros investigadores; tambien dan los valores de G para la sustitucion isotopica. Existen pruebas de que la marcacion del poliestireno se produce en virtud de una reaccion atomo-molecula. (author) [Russian] Tsel'yu nastoyashchego doklada yavlyaetsya rassmotrenie novykh sposobov uskoreniya reaktsii mezhdu radioaktivnym gazom i materialom misheni, podlezhashchim mecheniyu, a takzhe privedenie primerov uspeshnykh sluchaev. Ehti metody vklyuchayut ispol'zovanie razryadov mikrovoln i radiovoln, tleyushchikh razryadov pod vozdejstviem istochnikov postoyannogo ili peremennogo tokov, ili prosto radiatsii ul'trafioletovykh luchej. Byla dostignuta udel'naya aktivnost', dokhodyashchaya do 100 mikrokyuri na gramm, v znachitel'nykh kolichestvakh ochishchennogo produkta. Vremya vozdejstviya razryada bylo poryadka odnoj minuty, i vo mnogikh sluchayakh razlozhenie bylo chrezvychajno ogranichennym. Dayutsya podschety ehffektivnosti ispol'zovaniya ehnergii dlya proizvodstva mecheniya ehtimi metodami po sravneniyu s zatratoj dlya toj zhe tseli ehnergii ioniziruyushchego izlucheniya, ispol'zuemoj Vil'tsbakhom i dr. ; krome togo, ukazyvayutsya znacheniya radiatsionnokhimicheskogo vykhoda G dlya zameny izotopov. Est' ukazaniya na to, chto pri mechenii polistirola mekhanizm opredelyaetsya reaktsiej atom

Fluctuations in the East Asian monsoon recorded by pollen assemblages in sediments from the Japan Sea off the southwestern coast of Hokkaido, Japan, from 4.3 Ma to the present

Science.gov (United States)

Igarashi, Yaeko; Irino, Tomohisa; Sawada, Ken; Song, Lu; Furota, Satoshi

2018-04-01

We reconstructed fluctuations in the East Asian monsoon and vegetation in the Japan Sea region since the middle Pliocene based on pollen data obtained from sediments collected by the Integrated Ocean Drilling Program off the southwestern coast of northern Japan. Taxodiaceae conifers Metasequoia and Cryptomeria and Sciadopityacere conifer Sciadopitys are excellent indicators of a humid climate during the monsoon. The pollen temperature index (Tp) can be used as a proxy for relative air temperature. Based on changes in vegetation and reconstructed climate over a period of 4.3 Ma, we classified the sediment sequence into six pollen zones. From 4.3 to 3.8 Ma (Zone 1), the climate fluctuated between cool/moist and warm/moist climatic conditions. Vegetation changed between warm temperate mixed forest and cool temperate conifer forest. The Neogene type tree Carya recovered under a warm/moist climate. The period from 3.8 to 2.5 Ma (Zone 2) was characterized by increased Metasequoia pollen concentration. Warm temperate mixed forest vegetation developed under a cool/moist climate. The period from 2.5 to 2.2 Ma (Zone 3) was characterized by an abrupt increase in Metasequoia and/or Cryptomeria pollen and a decrease in warm broadleaf tree pollen, indicating a cool/humid climate. The Zone 4 period (2.2-1.7 Ma) was characterized by a decrease in Metasequoia and/or Cryptomeria pollen and an increase in cool temperate conifer Picea and Tsuga pollen, indicating a cool/moist climate. The period from 1.7 to 0.3 Ma (Zone 5) was characterized by orbital-scale climate fluctuations. Cycles of abrupt increases and decreases in Cryptomeria and Picea pollen and in Tp values indicated changes between warm/humid and cold/dry climates. The alpine fern Selaginella selaginoides appeared as of 1.6 Ma. Vegetation alternated among warm mixed, cool mixed, and cool temperate conifer forests. Zone 6 (0.3 Ma to present) was characterized by a decrease in Cryptomeria pollen. The warm temperate broadleaf

Experiments based on blue intensity for reconstructing North Pacific temperatures along the Gulf of Alaska

Science.gov (United States)

Wilson, Rob; D'Arrigo, Rosanne; Andreu-Hayles, Laia; Oelkers, Rose; Wiles, Greg; Anchukaitis, Kevin; Davi, Nicole

2017-08-01

Ring-width (RW) records from the Gulf of Alaska (GOA) have yielded a valuable long-term perspective for North Pacific changes on decadal to longer timescales in prior studies but contain a broad winter to late summer seasonal climate response. Similar to the highly climate-sensitive maximum latewood density (MXD) proxy, the blue intensity (BI) parameter has recently been shown to correlate well with year-to-year warm-season temperatures for a number of sites at northern latitudes. Since BI records are much less labour intensive and expensive to generate than MXD, such data hold great potential value for future tree-ring studies in the GOA and other regions in mid- to high latitudes. Here we explore the potential for improving tree-ring-based reconstructions using combinations of RW- and BI-related parameters (latewood BI and delta BI) from an experimental subset of samples at eight mountain hemlock (Tsuga mertensiana) sites along the GOA. This is the first study for the hemlock genus using BI data. We find that using either inverted latewood BI (LWBinv) or delta BI (DB) can improve the amount of explained temperature variance by > 10 % compared to RW alone, although the optimal target season shrinks to June-September, which may have implications for studying ocean-atmosphere variability in the region. One challenge in building these BI records is that resin extraction did not remove colour differences between the heartwood and sapwood; thus, long term trend biases, expressed as relatively warm temperatures in the 18th century, were noted when using the LWBinv data. Using DB appeared to overcome these trend biases, resulting in a reconstruction expressing 18th-19th century temperatures ca. 0.5 °C cooler than the 20th-21st centuries. This cool period agrees well with previous dendroclimatic studies and the glacial advance record in the region. Continuing BI measurement in the GOA region must focus on sampling and measuring more trees per site (> 20) and compiling

Converter for pulsed Bremsstrahlung generation on the basis of he linear electron accelerator EhLU-4 and the results of bipolar integrated circuits irradiation; Konvertur dlya generatsii impul`snogo tormoznogo izlucheniya na baze linejnogo uskoritelya ehlekutronov EhLU-4 i rezul`taty oblucheniya bipolyarnykh integral`nykh skhem

Energy Technology Data Exchange (ETDEWEB)

Korshunov, F P; Lazar` , A P; Gurinovich, N I

1994-12-31

Description and parameters of a converter produced on the base of EhLU-4 linear electron accelerators allowing one to obtain an intensive flux of pulsed Bremsstrahlung for radiation investigation are presented.

After-Ripening of Red Pepper (Capsicum Annuum) as Affected by Ionizing Radiation; Effets des Rayonnements Ionisants sur le Murissement du Piment (Capsicum Annuum) Apres la Recolte; Vliyanie ioniziruyushchego izlucheniya na dozrevanie krasnogo pertsa (Capsicum Annuum); Efecto de las Radiaciones Ionizantes en la Postmaturacion del Pimiento Rojo (Capsicum Annuum)

Energy Technology Data Exchange (ETDEWEB)

Farkas, J.; Kiss, I.; Andrassy, Eva [Central Food Research Institute, Budapest (Hungary)

1966-11-15

The direct effect of X-rays on freshly picked, sweet red pepper at dose levels of between 0 and 800 krad, and on the after-ripening of red pepper at dose levels of between 0 and 100 krad, was investigated. As an effect of the irradiation of between 400 and 800 krad, the pericarps softened; the carotenoid content, however, was not substantially reduced, even at a dose of 800 krad. During the nine weeks' storage period at room temperature, subsequent to irradiation, an increase of about 90% of the total pigment content, expressed as capsanthin, was observed in the samples not treated. The formation of the carotenoid pigments was accelerated, to some extent, by 80 rad, and substantially accelerated by treatment of 2 krad. The samples treated at the 2-krad level reached the same pigment content in three weeks as the control samples in eight weeks. In the radiation-treated samples, however, the pigment content decreased after the fourth to fifth week of storage. Dose levels above 10 krad slowed down or inhibited the formation of carotenoids during storage (after ripening). The reducing sugar content and the rate of drying were not affected by 0 to 100-krad doses. Since the several hundred kilorad irradiation doses needed to destroy, or substantially inhibit, the growth of moulds causing the deterioration of red pepper of high moisture content have a deleterious effect, the application of irradiation to decrease storage losses in fresh, picked red pepper does not seem to be advisable. The application, however, of the very low doses stimulating carotenoid formation does seem to be promising in view of shortening the after-ripening period and increasing the pigment content. Further investigations are needed to establish the most suitable storage conditions for the after-ripening of red peppers and the causes responsible for decrease in the carotenoid content of irradiated fruits in the second half of the storage period. (author) [French] Les auteurs ont etudie l'effet direct des rayons X a des doses comprises entre 0 et 800 krad sur le piment doux fraichement cueilli et a des doses comprises entre 0 et 100 krad sur le murissement du piment apres la recolte. Sous l'effet de l'exposition a une dose comprise entre 400 et 800 krad, les pericarpes se-sont amollis; toutefois, la teneur en carotenoides n'a pas ete sensiblement reduite, meme apres exposition a une dose de 800 krad. Au cours de la periode de neuf semaines consecutives a l'irradiation, pendant laquelle les piments ont ete emmagasines a la temperature ambiante, on a constate que la teneur totale en pigments, sous forme de capsanthine avait augmente d'environ 90% dans les echantillons non traites. La formation des pigments a base de carotenoides a ete acceleree dans une certaine mesure par l'exposition a une dose de 80 rad et sensiblement acceleree par l'exposition a une dose de 2 krad. Les echantillons soumis a une dose de 2 krad avaient au bout de trois semaines la meme teneur en pigments que les echantillons temoins au bout de huit semaines. Toutefois, la teneur en pigments des echantillons irradies a diminue apres une periode d'emmagasinage de quatre a cinq semaines. L'exposition a des doses superieures a 10 krad a ralenti ou inhibe la formation des carotenoides pendant la periode d'emmagasinage (apres maturation). La reduction de la teneur en sucres et la vitesse de dessiccation n'ont pas ete affectees par l'exposition a des doses de 0 a 100 krad. Etant donne les effets nefastes de l'exposition aux doses de rayonnements de plusieurs centaines de krad necessaires pour detruire les moisissures qui provoquent l'alteration du piment a forte teneur en eau, ou pour inhiber fortement le developpement de ces organismes, il ne semble pas souhaitable d'utiliser les rayonnements pour reduire les pertes de piments fraichement cueillis. Neanmoins, l'application des doses tres faibles qui stimulent la formation des carotenoides semble devoir donner de bons resultats, car elle abrege la duree de la maturation apres la recolte et augmente la teneur en pigments. Il serait necessaire de poursuivre les recherches afin de determiner les conditions d'emmagasinage les plus favorables a La maturation du piment apres la recolte ainsi que les causes de la diminution de la teneur en carotenoiedes de fruits irradies au cours de la deuxieme moitie de la periode de stockage. (author) [Spanish] Se ha investigado el efecto directo de los rayos X, en dosis de 0 a 800 krad, sobre pimientos rojos dulces iecien recolectados, y sobre la postmaturacion de estos pimientos, en dosis de 0 a 100 krad. La irradiacion entre 400 y 800 krad causo el ablandamiento del pericarpo, pero el contenido de carotenoides no disminuyo apreciablemente incluso a dosis de 800 krad. Durante un periodo de almacenamiento de nueve semanas a la temperatura ambiente y despues de la irradiacion, se observo en las muestras no tratadas un aumento de un 90fy del contenido total de pigmentos, expresado en capsantina. La formacion de pigmentos carotenoides presento una ligera aceleracion para dosis de 80 rad y una fuerte aceleracion para dosis de 2 krad. Las muestras tratadas con 2 krad alcanzaron en tres semanas el mismo contenido de pigmentos que las muestras testigo en ocho semanas. En cambio, el contenido de pigmentos de las muestras irradiadas disminuyo al cabo de la cuarta o quinta semana de almacenamiento. Las dosis superiores a 10 krad frenaron o impidieron la formacion de carotenoides durante el almacenamiento (postmaturacion). La disminucion del contenido de.azucares y el ritmo de desecacion permanecieron invariables para dosis de 0 a 100 krad. Como las dosis de radiaciones (varios centenares de kilorad) necesarias para impedir o inhibir en medida apreciable el desarrollo de los mohos causantes de la deterioracion del pimiento rojo de gran contenido de agua tienen efectos perjudiciales, no parece aconsejable el empleo de las radiaciones para reducir las perdidas por almacenamiento en los pimientos rojos recien recolectados. En cambio, la aplicacion de dosis muy bajas, que estimulan la formacion de carotenoides, parece un metodo interesante para reducir el periodo de postmaturacion y elevar el contenido de pigmentos. Se precisan nuevas investigaciones para determinar las condiciones optimas de almacenamiento de los pimientos rojos en periodo de postmaturacion, y las causas de la disminucion del contenido de carotenoides de los fiutos irradiados en la segunda mitad del periodo de almacenamiento. (author) [Russian] Bylo issledovano neposredstvennoe vlijanie rentgenovskih luchej na tol'ko chto sorvannyj sladkij krasnyj perec dozami moshhnost'ju ot 0 do 800'krad i vlijanie na dozrevanie krasnogo perca doz moshhnost'ju ot 0 do 100 krad. Vlijanie obluchenija dozami moshhnost'ju ot 400 do 800 krad projavilos' v smjagchenii okoloplodnikov, i soderzhanie karotinoida umen'shilos' neznachitel'no dazhe pod vlijaniem dozy moshhnost'ju v 800 krad. V techenie devjatinedel'nogo perioda hranenija pri komnatnoj temperature, sledovavshego za oblucheniem, v neobrabotannyh obrazcah nabljudalos' pochti 90% uvelichenie obshhego soderzhanija pigmenta, vyrazhennogo v vide capsantine. Obrazovanie karotinoidnyh pigmentov uskorjalos' do nekotoroj stepeni pri obrabotke dozami moshhnost'ju v 80 rad i znachitel'no uskorjalos' pri obrabotke dozami moshhnost'ju v 2 krad. Obrazcy, obrabotannye dozami v 2 krad v techenie 3 nedel' dostigali takogo soderzhanija pigmenta, kotoroe dostigalos' kontrol'nymi obrazcami za 8 nedel'. Tem ne menee, soderzhanie pigmenta v obrabotannyh posredstvom obluchenija obrazcah umen'shalos' posle chetvertoj-pjatoj nedeli hranenija. Dozy moshhnost'ju v 10 krad zamedljajut ili tormozjat obrazovanie karotinoidov v period hranenija (posle dozrevanija). Dozy ot 0 do 100 krad ne okazyvali vlijanija na umen'shenie soderzhanija sahara i skorost' vysyhanija. Tak kak dozy obluchenija v neskol'ko sot kilorad, neobhodimye dlja razrushenija ili sushhestvennogo tormozhenija rosta pleseni, vyzyvajushhej porchu krasnogo perca s vysokim soderzhaniem vlazhnosti, javljajutsja pagubnymi, primenenie obluchenija s cel'ju sokrashhenija poter' pri hranenii svezhesorvaniogo perca kazhetsja celesoobraznym. Odnako s tochki zrenija sokrashhenija perioda dozrevanija i uvelichenija soderzhanija pigmenta ispol'zovanie ochen' nizkih doz, stimulirujushhih obrazovanie karotinoida, predstavljaetsja mnogoobeshhajushhim. Dal'nejshie issledovanija neobhodimy s cel'ju opredelenija naibolee podhodjashhih uslovij hranenija dlja dozrevanija krasnogo perca i ustanovlenija prichin, vyzyvajushhih umen'shenie karotinoidnogo soderzhanija v obluchennyh fruktah vo vtoroj polovine perioda hranenija. (author)

Experiments based on blue intensity for reconstructing North Pacific temperatures along the Gulf of Alaska

Directory of Open Access Journals (Sweden)

R. Wilson

2017-08-01

Full Text Available Ring-width (RW records from the Gulf of Alaska (GOA have yielded a valuable long-term perspective for North Pacific changes on decadal to longer timescales in prior studies but contain a broad winter to late summer seasonal climate response. Similar to the highly climate-sensitive maximum latewood density (MXD proxy, the blue intensity (BI parameter has recently been shown to correlate well with year-to-year warm-season temperatures for a number of sites at northern latitudes. Since BI records are much less labour intensive and expensive to generate than MXD, such data hold great potential value for future tree-ring studies in the GOA and other regions in mid- to high latitudes. Here we explore the potential for improving tree-ring-based reconstructions using combinations of RW- and BI-related parameters (latewood BI and delta BI from an experimental subset of samples at eight mountain hemlock (Tsuga mertensiana sites along the GOA. This is the first study for the hemlock genus using BI data. We find that using either inverted latewood BI (LWBinv or delta BI (DB can improve the amount of explained temperature variance by > 10 % compared to RW alone, although the optimal target season shrinks to June–September, which may have implications for studying ocean–atmosphere variability in the region. One challenge in building these BI records is that resin extraction did not remove colour differences between the heartwood and sapwood; thus, long term trend biases, expressed as relatively warm temperatures in the 18th century, were noted when using the LWBinv data. Using DB appeared to overcome these trend biases, resulting in a reconstruction expressing 18th–19th century temperatures ca. 0.5 °C cooler than the 20th–21st centuries. This cool period agrees well with previous dendroclimatic studies and the glacial advance record in the region. Continuing BI measurement in the GOA region must focus on sampling and measuring more trees per

Low Tree-Growth Elasticity of Forest Biomass Indicated by an Individual-Based Model

Directory of Open Access Journals (Sweden)

Robbie A. Hember

2018-01-01

Full Text Available Environmental conditions and silviculture fundamentally alter the metabolism of individual trees and, therefore, need to be studied at that scale. However, changes in forest biomass density (Mg C ha−1 may be decoupled from changes in growth (kg C year−1 when the latter also accelerates the life cycle of trees and strains access to light, nutrients, and water. In this study, we refer to an individual-based model of forest biomass dynamics to constrain the magnitude of system feedbacks associated with ontogeny and competition and estimate the scaling relationship between changes in tree growth and forest biomass density. The model was driven by fitted equations of annual aboveground biomass growth (Gag, probability of recruitment (Pr, and probability of mortality (Pm parameterized against field observations of black spruce (Picea mariana (Mill. BSP, interior Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn. Franco, and western hemlock (Tsuga heterophylla (Raf. Sarg.. A hypothetical positive step-change in mean tree growth was imposed half way through the simulations and landscape-scale responses were then evaluated by comparing pre- and post-stimulus periods. Imposing a 100% increase in tree growth above calibrated predictions (i.e., contemporary rates only translated into 36% to 41% increases in forest biomass density. This corresponded with a tree-growth elasticity of forest biomass (εG,SB ranging from 0.33 to 0.55. The inelastic nature of stand biomass density was attributed to the dependence of mortality on intensity of competition and tree size, which decreased stand density by 353 to 495 trees ha−1, and decreased biomass residence time by 10 to 23 years. Values of εG,SB depended on the magnitude of the stimulus. For example, a retrospective scenario in which tree growth increased from 50% below contemporary rates up to contemporary rates indicated values of εG,SB ranging from 0.66 to 0.75. We conclude that: (1 effects of

The First Two Years of Operating Experience of the Kahl Nuclear Power Station; Experience acquise pendant les deux premieres annees de fonctionnement de la centrale nucleaire de Kahl; Opyt pervykh dvukh let ehkspluatatsii atomnoj ehlektrostantsii v Kale; Experiencia adquirida en los primeros cuatro anos de funcionamiento de la central nucleoelectrica de Kahl

Energy Technology Data Exchange (ETDEWEB)

Bruchner, H. J. [Aeg-Kernenergieanlagen, Frankfurt-am-Main (Germany); Weckesser, A. [Versuchs-Atomkraftwerk Kahl Gmbh, Kahl (Germany)

1963-10-15

, une boucle experimentale destinee a l'etude de la surchauffe nucleaire. (author) [Spanish] La central de Kahl constituye la primera central nucleoelectrica europea de propiedad privada, y funciona en carga desde junio de 1961. Esta equipada con un reactor de agua hi que trabaja en ciclo indirecto por circulacion natural. Su capacidad electrica neta asciende a 15 MW y hasta febrero de 1963 habia producido 140 millones de kWh. La memoria revisara la experiencia adquirida durante su funcionamiento, ante todo con el extenso programa de ensayos sobre el comportamiento transitorio y la exploracion gamma. Presentara datos acerca del resultado que han dado en funcionamiento ciertas partes de la central, tales como el dispositivo de accionamiento de las barras de control, el sistema de purificacion de los gases de escape y la turbina. Una vez terminado el programa de ensayos, la planta se exploto en carga basica durante algun tiempo a fin de reunir datos sobre el rendimiento del combustible en la ptactica. Una vez completada esta fase, se instalara en el reactor de Kahl un circuito experimental de sobrecalentamiento nuclear. (author) [Russian] Atomnaya ehlektrostantsiya v Kale, pervaya v Evrope chastnaya atomnaya ehlektrostantsiya, ehkspluatiruetsya pod nagruzkoj s iyunya 1961 goda. Na ehlektrostantsii ustanovlen reaktor s kipyashchej vodoj, kosvennym tsiklom i estestvennoj tsirkulyatsiej. Chistaya ehlektricheskaya moshchnost' reaktora sostavlyaet 15 mgvt. Do fevralya 1963 goda kolichestvo poluchennoj ehnergii sostavilo 140 mln. kvt.ch. Rassmotren opyt ehkspluatatsii, v chastnosti rasshirennaya programma ispytanij: naprimer,povedenie reaktora pri perekhodnom protsesse i kontrol' gamma-izlucheniya. Budut predstavleny rezul'taty izucheniya ehkspluatatsionnoj kharakteristiki nekotorykh komponentov ustanovki, naprimer sistemy privoda reguliruptsikh sterzhnej, sistemy udaleniya gaza i turbiny. Posle osushchestvleniya ehtoj programmy ispytanij ustanovka v techenie nekotorogo vremeni

Cobalt-60 and Caesium-137 Gamma Sources; Sources de rayonnement gamma au cobalt-60 et au cesium-137; Gamma-istochniki iz kobal'ta-605 i tseziya-137; Fuentes gamma de cobalto-60 y de cesio-137

Energy Technology Data Exchange (ETDEWEB)

Kulish, E E; Fradkin, G M [Academy of Sciences of the USSR, Moscow, Union of Soviet Socialits Republics (Russian Federation)

1960-07-15

cobalto-60 y cesio-137 producidas en la Union Sovietica y se examinan algunos problemas de orden tecnologico planteados por su fabricacion. En el informe figuran una serie de datos sobre las propiedades de las radiaciones emitidas por las fuentes de {sup 60}Co y {sup 137}Cs y del material con que estas se fabrican. Se facilitan informaciones sobre la influencia que la magnitud del flujo neutronico y las caracteristicas geometricas de la muestra ejercen sobre la actividad de la fuente; el informe tambien contiene datos sobre el rendimiento de los distintos isotopos de cesio obtenidos por fision de los nucleos de uranio. Se examinan los procedimientos para encerrar hermeticament e las fuentes y se facilita una lista completa de las fuentes utilizadas en la Union Sovietica, con indicacion de sus caracteristicas geometricas y de su actividad. Por ultimo, se hace un estudio comparativo de las fuentes de {sup 60}Co y {sup 137}Cs. (author) [Russian] V doklade privodyatsya osnovnye tekhnicheskie kharakteristiki vypuska- emykh v SSSR gamma-istochnikov na osnove kobal'ta-60 i tseziya-137, a takzhe rassmatrivayutsya nekotorye voprosy tekhnologii ikh proizvodstva. Doklad soderzhit svedeniya o sostave izlucheniya izotopov Co{sup 60} i Cs{sup 137} i syr'ya, iz kotorogo oni izgotavlivayutsya . Privodyatsya dannye o zavisimosti aktivnosti kobal'tovykh istochnikov ot velichiny potoka nejtronov i geometricheskikh razmerov obraztsa, a takzhe dannye o velichine vykhoda izotopov tseziya pri delenii yader urana. Dalee rassmatrivaetsya vopros o germetizatsii istochnikov i privoditsya polnaya nomenklatura vypuskaemykh v SSSR istochnikov s ukazaniem ikh geometricheskikh razmerov i velichiny aktivnosti. V kontse provoditsya nekotoroe sravnenie istochnikov Co{sup 60} i Cs{sup 137}. (author)

Theoretical and Applied Aspects of Radiation D-Values for Spores of Clostridium Botulinum; Aspects Theoriques et Pratiques des Valeurs D de Rayonnement Appliquees aux Spores de Clostridium Botulinum; Teoreticheskie i prikladnye aspekty koehffitsienta izlucheniya odlya spor Clostridium Botulinum; Aspectos Teoricos y Practicos de los Valores D para Esporas del Clostridium Botulinum

Energy Technology Data Exchange (ETDEWEB)

Grecz, N. [Biophysics Laboratory, Illinois Institute Of Technology, Chicago, IL (United States)

1966-11-15

Spores of C. botulinum have been found to have equal or greater resistance to ionizing radiations than spores of other non-toxic food spoilage organisms. For this reason the microbiological processing standards for radiation preservation of foods were invariably related to radiation resistance of spores of C. bonilinum. The index of radioresistance is the D{sub 10}-value defined as the dose necessary to inactivate one log cycle (90%) of a given spore population and 12 XD has been arbitrarily defined as the safe radiation preservation dose for food products. Extensive data from the author's laboratory revealed that (a) the D{sub 10} -value of a particular strain depended on temperature, medium and size of spore inoculum and (b) substantially different D-values may be obtained depending on the method of calculation and unknown variations from experiment to experiment. This information provides a basis for reappraisal of the 12D concept. The temperature during radiation can be shown to influence indirect effects of radicals: (a) their formation, (b) chemical reactivity, (c) extent of annealment and (d) diffusion, especially during liquid-solid transition of the medium around 0 Degree-Sign C. A combination of these temperature-dependent effects explains why spores are most sensitive when irradiated at 0 Degree-Sign C as compared with higher or lower temperatures. In addition to its effect on radicals, the temperature also affects the essential targets (DNA) directly. This involves the vibrational state as well as the extent of hydration of the DNA molecules. The apparent hydration of DNA is related to the range of action of indirect effects which can be calculated for C. botulinum 33A to add an additional 30A to the radius of DNA (10.5A), i.e. almost triple the effect of radiation. This change in radiosensitive volume is reflected by a corresponding change in D{sub 37} value from 1.6 x 10{sup 5} rad for the dry spore to 6.6 x 10{sup 4} rad for the wet spore. The suspending medium may either compete for radicals, e.g. most foods and microbiological media are radical scavengers, or it may promote formation of harmful radicals, e. g. phosphate buffer forms phosphinic acid, oxygen forms peroxy and perhydroxye radicals. Changes of D{sub 10}-values of an individual strain caused by various environmental conditions can be related to indirect effects, while changes of D{sub 10} values from strain to strain under standardized conditions relate to the amount and structure of nucleoid DNA in spores. In this respect all strains of C. botulinum studied to date can be tentatively divided into three groups: Group 1 includes strains (A, B and E) with D values around 0.13 Mrad or less. These spores exhibit single-hit inactivation curves and have probably one chromosome with a low repair probability. Group 2 includes strains 12885 A, 62A, 77A, 9B clustering around D{sub 10} =0.23 Mrad. Available target data suggest that these spores possess one chromosome of 900 {mu} with a repair multiplicity of 13. Group 3 includes the highly-resistant strains 33A, 36A, 40B, 41B, and 53B clustering around D{sub 10} = 0.33 Mrad. Available target data suggest that these spores possess two chromosomes of 900{mu} each with a repair multiplicity (N) between 80 and 90, i.e. N = 13{sup 2}/2. (author) [French] Il a ete constate que les spores de C. botulinum offrent aux rayonnements ionisants une resistance qui est egale ou superieure a celle des spores d'autres organismes non toxiques provoquant l'alterration des denrees alimentaires. Pour cette raison, les normes de traitement microbiologique appliquees pour la conservation des aliments par les rayonnements sont toujours fonction de la radioresistance des spores de C. botulinum. L'indice de cette radioreistance est la valeur Dio definie comme la dose necessaire pour inactiver un cycle logarithmique (90%) d'une population de spores donnee, tandis que le terme 12 x D a ete arbitrairement defini comme la dose sure pour la conservation des aliments par irradiation. Il ressort des donnees detaillees fournies par le Laboratoire de biophysique de Chicago que a) la valeur D{sub 10} pour une souche donnee est fonction de la temperature, du milieu et de la quantite de spores inoculee, et b) on peut obtenir des valeurs D sensiblement diffeentes selon la methode de calcul appliquee et a cause de certains facteurs inconnus qui varient d'une experience a l'autre. Ces renseignements fournissent la base d'une reevaluation du concept 12D. Il est possible de demontrer que la temperature qui regne pendant l'irradiation influe sur les effets indirects sur les radicaux, savoir: a) formation, b) reactivite chimique, c) degre d'attenuation, d) diffusion, notamment pendant la transition liquide/solide du milieu aux environs de 0 Degree-Sign C. Une combinaison de ces divers effets de la temperature explique pourquoi les spores sont plus sensibles a l'irradiation a 0 Degree-Sign C qu'a des temperatures superieures ou inferieures. Outre l'effet qu'elle exerce sur les radicaux, la temperature influe directement sur les cibles essentielles (ADN). En l'occurrence, il s'agit aussi bien de l'etat vibrationnel que du degre d'hydratation des molecules d'ADN. L'hydratation apparente de l'ADN est en rapport avec les effets indirects et l'on peut calculer que, pour C. botulinum 33A, il en resulte une augmentation de 30A du rayon de l'ADN (10, 5A), ce qui triple presque l'effet des rayonnements. Cette modification du volume radiosensible se traduit par une modification correspondante de la valeur D{sub 37}, qui passe de 1,6 x 10{sup 5} rad pour la spore seche a 6,6 x 10{sup 4} rad pour la spore humide. Le milieu de suspension peut, soit rechercher les radicaux (comme c'est le cas de la plupart des aliments et des milieux microbiologiques qui sont des absorbeurs de radicaux), soit favoriser la formation de radicaux nuisibles: ainsi, le phosphate tampon forme de l'acide phosphinique et l'oxygene forme des radicaux peroxy- et perhydroxy-. ' Les modifications des valeurs D{sub 10}-d'une souche donnee qui resultent de diverses conditions ambiantes peuvent etre rapportees a des effets indirects, tandis que les modifications des valeurs D{sub 10} d'une souche a l'autre dans des conditions normalisees se rapportent a la quantite et a la structure de l'ADN contenu dans le noyau des spores. A cet egard, toutes les souches de C. botulinum etudiees jusqu'ici pourraient, a titre provisoire, etre classees en trois groupes. Le groupe l comprend les souches A, B et E qui correspondent a des valeurs de D se situant aux environs de 0,13 Mrad ou au-dessous; ces spores donnent des courbes d'inactivation apres une seule irradiation et comportent, semble-t-il,- un seul chromosome a faible probabilite de restauration. Le groupe 2 comprend les souches 12885A, 62A, 77A, 9B groupees autour de D io = 0,23 Mrad; les donnees sur les cibles dont on dispose indiqueraient que ces spores possedent un chromosome de 900{mu} avec un indice de restauration de 13. Le groupe 3 comprend les souches tres resistantes 33A, 36A, 40B, 41B et 53B groupees autour de D{sup 10} = 0,33 Mrad; ici, les donnees sur les cibles dont on dispose indiqueraient que ces spores possedent deux chromosomes de 900{mu} chacun, avec un indice de restauration (N) compris entre 80 et 90, soit N = 13{sup 2}/2. (author) [Spanish] Se ha comprobado que las esporas del C. botulinum ofrecen una resistencia a las radiaciones ionizantes igual o superior a la de las esporas de otros organismos atoxicos'que estropean los.alimentos. Por esta razon, las normas de tratamiento microbiologico para la conservacion de alimentos se han relacionado siempre con la radiorresistencia de las esporas del C. botulinum. El indice de radiorresistencia es el valor D{sub 10}, definido como la dosis necesaria para inactivar un ciclo de desarrollo logaritmico (90%) de lina poblacion dada de esporas, habiendose, fijado arbitrariamente en 12 x D la dosis para la conservacion sin ' riesgos de los alimentos por irradiacion. La copiosa informacion obtenida por los autores en su laboratorio ha puesto de manifiesto: a) que el valor D{sup 10} de una determinada cepa depende de la temperatura, del medio y de la cantidad de inoculo de esporas, y b) que segun el metodo de calculo empleado y como consecuencia de variaciones desconocidas entre un experimento y otro, pueden obtenerse valores D fundamentalmente distintos. Esta informacion justifica una reevaluacion del concepto de 12 X D. Puede demostrarse que la temperatura empleada durante la irradiacion influye indirectamente, de distintas formas, sobre los radicales: a) su formacion;, b) reactividad quimica; c) duracion del recocido y d) difusion, particularmente durante la transicion de lfquido a solido del medio en torno a los 0 Degree-Sign C. La combinacion de estos efectos, que son funcion de la temperatura, explica por que las esporas son mas sensibles cuando se las irradia a 0 Degree-Sign C que cuando se emplean temperaturas mas altas o mas bajas. Ademas de sus efectos sobre los radicales, la temperatura afecta tambien, directamente, a los blancos esenciales (ADN). En esto interviene el estado vibracional asf como el grado de hidratacion de las moleculas de ADN. La hidratacion aparente del.ADN esta relacionada con el intervalo de accion de los efectos indirectos, que para el C. botulinum 33A puede calcularse que anade 30 A al radio del ADN (10, 5A), es decir, casi se, triplica el efecto de la radiacion. Esta variacion del volumen radiosensible se refleja en-un cambio correspondiente del valor D{sub 37}, que pasa de 1,6 x 10{sup 5} rad para las esporas secas a 6,6 x 10{sup 4} rad para las esporas humedas. El medio de suspension puede competir por los radicales (por ejemplo: la mayoria de los alimentos y de los medios microbiologicos son depuradores de radicales), o facilitar la formacion de radicales per judiciales (por ejemplo: el fosfato amortiguador forma acido fosffnico y el oxfgeno forma radicales peroxilo y perhidroxilo). Las variaciones de los valores D{sub 10} de una determinada cepa motivadas por diversas condiciones ambientales pueden relacionarse con los efectos indirectos, en tanto que las variaciones en los valores Dio entre una cepa y otra en condiciones normalizadas se relacionan con la cantidad y la estructura del ADN nucleoide de las esporas. A este respecto, todas las cepas del C. botulinum estudiadas hasta la fecha pueden ser clasificadas provisionalmente en tres grupos. El grupo 1 comprende las cepas (A, B y E); con valores D de 0,13 Mrad aproximadamente o menores. Estas esporas proporcionan curvas de activacion de impacto unico, y probablemente tienen un solo cromosoma, con una probabilidad muy baja de autorregeneracion. El grupo 2 comprende las cepas 12885A, 62A, 77A y 9B, cuyo valor D{sub 10} es del orden de 0,23 Mrad. Los datos de que se dispone sobre los blancos sugieren que esas esporas poseen un solo cromosoma de 900 {mu}m con un factor de autorregeneracion de 13. El grupo 3 comprende las cepas sumamente resistentes 33A, 36A, 40B, 41B y 53B, siendo el correspondiente valor D{sub 10} =0,33 Mrad. Los datos de que se dispone sobre los blancos sugieren que estas esporas poseen dos cromosomas de 900 {mu} cada una, con un factor de autorregeneracion (N) comprendido entre 80 y 90, es decir, N = 13{sup 2}/2. (author) [Russian] Ustanovleno, chto spory iClostridium botulinum. imejut ravnuju ili bol'shuju stojkost' k vozdejstviju ionizirujushhih izluchenij, chem spory drugih netoksichnyh organizmov, portjashhih produkty. Po jetoj prichine standarty mikrobiologicheskoj obrabotki v celjah konservacii produktov s pomoshh'ju izluchenij neizmenno svjazyvalis' so stojkost'ju spor S. botulinum k vozdejstviju izluchenij. Kojefficient radiostojkosti predstavljaet soboj znachenie D{sub 10} , opredeljaemoe kak doza, neobhodimaja dlja odnogo cikla 90% inaktivacii odnoj populjacii, i 12-D bylo proizvol'no opredeleno, kak bezopasnaja doza obluchenija dlja sohranenija pishhevyh produktov. Obshirnye dannye, imejushhiesja v laboratorii, pokazali, chto: 1) znachenie kojefficienta D{sub 10} opredelennogo vida zavisit ot temperatury, sredy i razmera spor i 2) sushhestvenno razlichnye znachenija kojefficienta D mogut byt' polucheny v zavisimosti ot metoda rascheta i neizvestnyh variacij v razlichnyh jeksperimentah. Jeta informacija obespechivaet osnovu dlja pereocenki koncepcii 12 x D. Pokazano, chto temperatura'vo vremja obluchenija mozhet vozdejstvovat' na kosvennye vlijanija radikalov: 1) na obrazovanie, 2) na himicheskuju reaktivnost', 3) na stepen' razrushenija i 4) na diffuziju, osobenno vo vremja perehoda sredy iz zhidkogo sostojanija v tverdoe pri temperature primerno 0 Degree-Sign S. Kombinacija jetih vlijanij v zavisimosti ot temperatury ob'jasnjaet, pochemu spory naibolee chuvstvitel'ny, kogda oni obluchajutsja pri temperature 0 Degree-Sign S, po sravneniju s bolee vysokimi ili nizkimi temperaturami. Krome ee vlijanija na radikaly, temperatura takzhe vlijaet neposredstvenno na osnovnye, misheni (DNK). Jeto zatragivaet vibracionnoe sostojanie, a takzhe i stepen' gidratacii molekul DNK. Ochevidnaja gidratacija DNK svja zana s diapazonom dejstvija kosvennyh vlijanij, kotoryj mozhet byt' vychislen dlja C.botulinum 33 A, chtoby dobavit' 30 A k radiusu DNK (10,5 A), t.e. pochti v tri raza bol'she vlijanija obluchenija. Jeto izmenenie v radiochuvstvitel'nom ob'eme otrazhaetsja sootvetstvujushhim izmeneniem v znachenii D{sub 37} ot 1,6 x 10{sup 5} rad dlja suhoj spory do 6,6 x 10{sup 4} rad dlja vlazhnoj spory. Suspenzirujushhaja sreda mozhet byt' libo okonchatel'noj dlja radikalov, tak, naprimer, bol'shinstvo produktov i mikrobiologicheskih sred javljajutsja raskisliteljami radikalov, libo ona mozhet sposobstvovat' obrazovaniju vrednyh radikalov, tak naprimer, fosfatnyj buffer obrazuet fosfatnuju kislotu, kislorod obrazuet perekisnye i pergidridnye radikaly. Izmenenie znachenij D{sub 10} otdel'nogo vida, vyzvannye razlichnymi okruzhajushhimi uslovijami, mogut byt' svjazany s kosvennym vlijaniem, v to vremja, kak izmenenija Dio U razlichnyh vidov pri ravnyh uslovijah svjazany s kolichestvom i strukturoj nuklida DNK v sporah. V jetom otnoshenii vse vidy S. botulinum, izuchennye v nastojashhee vremja, mogut byt' jeksperimental'no razdeleny na tri gruppy: gruppa 1 vkljuchaet vidy (A, V i E) so znachenijami D primerno 0,13 Mrad ili menee. Jeti spory dajut krivye odinochnoj inaktivacii soudarenij i imejut verojatno odnu hromosomu s nizkoj stepen'ju vosstanovlenija. Gruppa 2 vkljuchaet vidy 12 885 A, 62 A, 77 A i 9 V, gruppirujushhiesja okolo D{sup 10} = 0,23 Mrad. Imejushhiesja dannye o mishenjah pokazyvajut, chto jeti spory imejut odnu hromosomu 900 mikron s kojefficientom vosstanovlenija 13. Gruppa 3 vkljuchaet vysokostojkie vidy 33 A, 36 A, 40 V, 41 V i 53 3, gruppirujushhiesja okolo D{sub 10} =0,33 Mrad. Imejushhiesja dannye o mishenjah pokazyvajut, chto jeti spory imejut dve hromosomy po 90 mikron kazhdaja c kojefficientom vosstanovlenija (N) mezhdu 80 i 90, t.e. N = 13{sup 2}/2 . (author)

Structural and compositional controls on transpiration in 40- and 450-year-old riparian forests in western Oregon, USA.

Science.gov (United States)

Moore, Georgianne W; Bond, Barbara J; Jones, Julia A; Phillips, Nathan; Meinzer, Federick C

2004-05-01

Large areas of forests in the Pacific Northwest are being transformed to younger forests, yet little is known about the impact this may have on hydrological cycles. Previous work suggests that old trees use less water per unit leaf area or sapwood area than young mature trees of the same species in similar environments. Do old forests, therefore, use less water than young mature forests in similar environments, or are there other structural or compositional components in the forests that compensate for tree-level differences? We investigated the impacts of tree age, species composition and sapwood basal area on stand-level transpiration in adjacent watersheds at the H.J. Andrews Forest in the western Cascades of Oregon, one containing a young, mature (about 40 years since disturbance) conifer forest and the other an old growth (about 450 years since disturbance) forest. Sap flow measurements were used to evaluate the degree to which differences in age and species composition affect water use. Stand sapwood basal area was evaluated based on a vegetation survey for species, basal area and sapwood basal area in the riparian area of two watersheds. A simple scaling exercise derived from estimated differences in water use as a result of differences in age, species composition and stand sapwood area was used to estimate transpiration from late June through October within the entire riparian area of these watersheds. Transpiration was higher in the young stand because of greater sap flux density (sap flow per unit sapwood area) by age class and species, and greater total stand sapwood area. During the measurement period, mean daily sap flux density was 2.30 times higher in young compared with old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees. Sap flux density was 1.41 times higher in young red alder (Alnus rubra Bong.) compared with young P. menziesii trees, and was 1.45 times higher in old P. menziesii compared with old western hemlock (Tsuga heterophylla (Raf

Radiation Synthesis of Stannous Dibromodibutyl; Synthese radiochimique de l'etain dibromopibutyle; Radiatsionno-khimicheskij sintez dibromdibutilolova; Sintesis radioquimica del dffiromodibutilestano

Energy Technology Data Exchange (ETDEWEB)

Abramova, L. V.; Vereshchinskij, I. V.; Kocheshkov, K. A.; Miretskij, V. Yu.; Pozdneev, V. V.; Ryabukhin, Yu. S.; Sheverdina, N. I.

1963-11-15

dosimetro de sulfato de hierro es de {approx}50 rad/s. Se utilizaron diversas proporciones de estafio metalico en polvo y bromuro de butilo de distintos grados de pureza. Se comprobo que en tales condiciones se desarrolla una reaccion radioquimica orientada en virtud de la cual se produce basicamente dibromodibutilestaflo con elevado rendimiento. Se demostro que el proceso tiene un periodo de induccion cuya duracion depende de la pureza del bromuro de butilo inicial. Este mismo factor influye tambien notablemente en la velocidad de formacion del producto final. Se comprobo que el estafio que no interviene en la reaccion puede volver a utilizarse para obtener dibromodibutilestaflo, pero en ese caso se anula por completo el periodo de induccion. Estas propiedades satisfacen los requisitos para la realizacion de un proceso continuo. Los autores proponen un mecanismo de reaccion, para explicar las leyes de este proceso que se desarrolla con un elevado rendimiento radioquimico. (author) [Russian] Printsipial'naya vozmozhnost' sinteza olovoorganicheskikh soedinenij pri dejstvii {gamma}-izlucheniya Co{sup 60} na smesi metallicheskogo olova i sootvetstvuyushchikh galoidalkilov vpervye byla ustanovlena Abramovoj, Kocheshkovym i SHeverdinoj v 1956 g. Usloviya provedeniya opytov v steklyannoj apparature bez peremeshivaniya ne pozvolyali vyyavit' kineticheskie zakonomernosti obrazovaniya ehtogo klassa metalloorganicheskikh soedinenij. Nastoyashchaya rabota byla postavlena dlya vyyasneniya vliyaniya ryada faktorov na skorost' radiatsionno-khimicheskogo sinteza olovoorganicheskikh soedinenij na primere dibromdibutilolova. S ehtoj tsel'yu byla skonstruirovana i izgotovlena spetsial'naya ustanovka s periodicheskoj zagruzkoj komponentov i vygruzkoj produktov reaktsii. Otlichitel'nymi osobennostyami ustanovki yavlyalis' vozmozhnost' ee termostatirovaniya, osushchestvlenie ehffektivnogo peremeshivaniya i periodicheskogo otbora prob dlya analizov. Osnovnoj uzel ustanovki (reaktsionnyj sosud iz

Effects of Ionizing Radiation on Insects and Other Arthropods; Effet des rayonnements ionisants sur les insectes et autres arthropodes; Vozdejstvie ioniziruntsej radiatsii na nasekomykh i drugikh chlenistonogikh; Efectos de las radiaciones ionizantes sobre los insectos y otros artropodos

Energy Technology Data Exchange (ETDEWEB)

Stone, William E. [United States Department of Agriculture Laboratories, Mexico City, D.F (Mexico)

1963-09-15

razvedeniya nasekomykh v massovykh kolichestva. S drugoj storony, nekotorye vidy nasekomykh yavlyayutsya nastol'ko mnogochislennymi, chto primenenie ehtogo metoda mozhet okazat'sya neosushchestvimym bez predvaritel'noj obrabotki zarazhennogo rajona drugimi sredstvami istrebleniya dlya privlecheniya na dostupnoe rasstoyanie populyatsij nasekomykh. Nesmotrya na ehti zatrudneniya, pri blagopriyatnykh obstoyatel'stvakh vryad li kakie-libo drugie metody istrebleniya vrednykh nasekomykh predstavlyayutsya stol' zhe perspektivnymi. Metod sterilizatsii pri pomoshchi radiatsii mozhet sluzhit' sposobom otdaleniya invazii do okonchaniya sbora urozhaya. V doklade soobshchaetsya o vozdejstvii gamma-izlucheniya na potentsial razmnozheniya, polovuyu agressivnost', silu i zhivuchest' vostochnoj plodovoj mukhi Rasiv dorsalis (Hendel), dynnoj mukhi Dacus cucurbltae (Coq.), sredizemnomorskoj plodovoj mukhi Ceratltla capitata (Wied.), meksikanskoj plodovoj mukhi Anastrepha ludens (Loew) i malyarijnogo komara Anopheles quadrlmaculatus (Say); v doklade privodyatsya takzhe rezul'taty prakticheskikh ispytanij vypuske sterilizovannykh samtsov na opytnoe pole dlya istrebleniya populyatsij. Daetsya opisanie dal'nejshego khoda kampanii po istrebleniyu bych'ego ovoda Cochliomyla homlnlvorax (Cqrl.) v Soedinennykh Shtatakh Ameriki i izucheniya razvedeniya sil'nykh, geneticheski markirovannykh osobej, kotorye pozvolyat legko vyyavlyat' vypushchennykh na votgyu sterilizovannykh ovodov. Obsuzhdayutsya takzhe rezul'taty issledovanij po oblucheniyu 6 dopolnitel'nykh vidov vreditelej, porazhayushchikh frukty, ovoshchi, polevye i lesnye kul'tury, 3 vidov, porazhaptsikh skot, i 3 vidov, napadayushchikh glavnym obrazom na cheloveka, a takzhe vozdejstvie oblucheniya ka skorpionov Centruroides limpidus (Karsch), odnozvezdchatogo kleshcha AshYuovdaa americanum (L.); dalee obsuzhdaetsya vozmozhnost' ispol'zovaniya ioniziruitsego izlucheniya v kachestve vozmozhnogo garantijnogo sredstva dlya dezinfestatsii ovoshchej i

Root phenology at Harvard Forest and beyond

Science.gov (United States)

Abramoff, R. Z.; Finzi, A.

2013-12-01

Roots are hidden from view and heterogeneously distributed making them difficult to study in situ. As a result, the causes and timing of root production are not well understood. Researchers have long assumed that above and belowground phenology is synchronous; for example, most parameterizations of belowground carbon allocation in terrestrial biosphere models are based on allometry and represent a fixed fraction of net C uptake. However, using results from metaanalysis as well as empirical data from oak and hemlock stands at Harvard Forest, we show that synchronous root and shoot growth is the exception rather than the rule. We collected root and shoot phenology measurements from studies across four biomes (boreal, temperate, Mediterranean, and subtropical). General patterns of root phenology varied widely with 1-5 production peaks in a growing season. Surprisingly, in 9 out of the 15 studies, the first root production peak was not the largest peak. In the majority of cases maximum shoot production occurred before root production (Offset>0 in 32 out of 47 plant sample means). The number of days offset between maximum root and shoot growth was negatively correlated with median annual temperature and therefore differs significantly across biomes (ANOVA, F3,43=9.47, pGrowth form (woody or herbaceous) also influenced the relative timing of root and shoot growth. Woody plants had a larger range of days between root and shoot growth peaks as well as a greater number of growth peaks. To explore the range of phenological relationships within woody plants in the temperate biome, we focused on above and belowground phenology in two common northeastern tree species, Quercus rubra and Tsuga canadensis. Greenness index, rate of stem growth, root production and nonstructural carbohydrate content were measured beginning in April 2012 through August 2013 at the Harvard Forest in Petersham, MA, USA. Greenness and stem growth were highest in late May and early June with one clear

Development of Radiation-Sterilized Sea Food Products. I. Enzyme-Inactivated Cod and Halibut Patties; Essais de Radiosterilisation des Produits Alimentaires d'Origine Marine. I. Pates de Morue et de Fletan a Enzymes Inactives; Primenenie izlucheniya dlya sterilizatsii morskikh pishchevykh produktov; Preparacion de Alimentos de Origen Marino Esterilizados por Irradiacion. I. Pastelillos de Bacalao y de Hipogloso con Enzimas Inactivadas

Energy Technology Data Exchange (ETDEWEB)

Sinnhuber, R. O.; Landers, Mary K.; Yu, T. C. [Department of Food Science And Technology, Oregon State University, Corvallis, OR (United States); Simon, M.; Heiligman, F. [United States Army Natick Laboratories, Natick, MA (United States)

1966-11-15

Radiation-sterilized enzyme-inactivated cod (Gadus macrocephalus) and halibut (Hippoglossus stenolepsis) patties or cakes were developed which show promise as commercial products. They were prepared by incorporating the comminuted fish with white corn meal, gelatin, and salt and forming the mixture into sausages. Enzymes were inactivated by heating the sausages in a boiling water-bath. After cooling overnight to set the protein, the sausages were sliced into 3/8-in-thick patties, packed in cans and given a radiation dose of 4.5 Mrad. The radiation sterilized products were stored for 12 months at 72 Degree-Sign F with periodic evaluations to assess the quality and the effect of various treatments. The treatments included vacuum packing, the addition of various antioxidants, and the use of charcoal packets. The products just prior to serving were dipped in batter and breading and deep-fried. The fish patties were evaluated by flavorpanels and objective measurements, such as total volatile bases, 2-thiobarbituric acid number, pH and colorrreflectance values. The products received acceptable flavor scores from preference panels (140 to 170 judges) during twelve months of storage at 72 Degree-Sign F. Although the panels preferred the non-irradiated control samples to the irradiated samples after 12 months, all stored irradiated patties scored on the ''like'' side of the 9-point hedonic scale. The color-reflectance values of radiation-sterilized seafood products can be used as a measure of the radiation-induced browning and seemed to correlate with length of storage. (author) [French] Les auteurs ont mis au point des pates ou hachis de morue (Gadus macrocephalus) et de fletan (Hippoglossus stenolepsis) a enzymes inactives, sterilises par rayonnement, qui semblent pouvoir etre commercialises. Ils ont ete prepares par malaxage du poisson finement hache avec de la farine de mais blanche, de la gelatine et du sel, le melange etant debite sous forme de saucisses. Les enzymes ont ete inactives par Inverted-Exclamation-Mark immersion des saucisses dans un bain d'eau bouillante. Apres refroidissement pour laisser prendre les proteines, les saucisses ont ete debitees en tranches de 1 cm d'epaisseur, puis mises en boites et irradiees a 4,5 Mrad. Le produit radiosterilise a ete emmagasine pendant 12 mois a une temperature de 22 Degree-Sign C; il- a ete procede periodiquement a une evaluation de la qualite et de l'effet des divers traitements. Ces traitements comportaient l'emballage sous vide, l'addition de divers anti-oxydants et l'emploi de paquets de charbon de bois. Pour la consommation, les produits ont ete trempes dans de la pate a frire, roules dans de la chapelure et passes a la friture. Le produit a ete evalue par des groupes de degustateurs; on a egalement fait des mesures objectives sur le total des bases volatiles, l'indice d'acide 2-thiobarbiturique, le pH et le coefficient de reflexion des couleurs. Les groupes de degustateurs (composes de 140 a 170 membres) ont donne des cotes satisfaisantes aux produits pendant 12 mois de stockage a 22 Degree-Sign C. Bien que ces groupes aient prefere les echantillons temoins non irradies aux echantillons irradies, apres 12 mois, tous les pates irradies conserves ont ete classes du cote positif de l'echelle hedonistique des qualites (neuf degres). Le coefficient de reflexion des couleurs des produits alimentaires d'origine marine radiosterilises peut servir a evaluer le brunissement produit par l'action des rayonnements et parait etre en rapport avec la duree de conservation. (author) [Spanish] Se han preparado pastelillos o tortas de bacalao (Gadus macrocephalus) e hipogloso (Hippoglossus stenolepsis) esterilizados por irradiacion, con inactivacion de enzimas, productos que ofrecen interes desde el punto de vista comercial. Se prepararon mezclando el pescado picado con harina de maiz, gelatina y sal y dando a la masa forma de salchicha. Las enzimas se inactivaron calentando las salchichas en un baflo de agua hirviente. Despues de dejarlas enfriar durante un dfa, para que las proteinas se asentasen, se cortaron en pastelillos de 3/8 pulg. de espesor, se envasaron en latas y se sometieron a una dosis de irradiacion de 4,5 Mrad. Los productos radioesterilizados se almacenaron durante 12 meses a 72 Degree-Sign F, y se sometieron a examenes periodicos para evaluar la calidad y el efecto de varios tratamientos. Los tratamientos que se aplicaron fueron: envasado al vacfo, adicion de varios antioxidantes y empleo de paquetes de carbon vegetal. Antes de servirlos, los pastelillos fueron rebozados en besamela y empanados, y se frieron bien. La coniestibilidad de los pastelillos se estudio por medio de grupos de catadores y de mediciones objetivas, tales como contenido total de bases volatiles, fndice de acido 2-tiobarbiturico, pH e indice de reflectancia cromatica. El sabor de los productos recibio puntuaciones aceptables de grupos de catadores (140 a 170 personas) durante 12 meses'de almacenamiento a 72 Degree-Sign F. Aunque los catadores prefirieron las muestras testigo no irradiadas a los productos irradiados, todos los pastelillos irradiados almacenados puntuaron en la parte positiva de la escala hedonfstica de 9 puntos. Los indices de reflectancia cromatica de los productos alimenticios marinos radioesterilizados pueden utilizarse para medir el dorado producido por la irradiacion y parecen guardar correlacion con la duracion del almacenamiento. (author) [Russian] Byli prigotovleny lepeshki iz treski (Gadus macrocephalus) i paltusa (Hippoglossus steno- lepsis), sterilizovannye s pomoshh'ju obluchenija i inaktivirovannye v otnoshenii dejstvija jenzimov, kotorye javljajutsja perspektivnymi s kommercheskoj tochki zrenija. Oni prigotavlivajutsja putem smeshenija razmel'chennoj ryby s beloj kukuruznoj mukoj, zhelatinom i sol'ju, posle chego jetoj smesi pridaetsja forma kolbasok. Inaktivacija jenzimov dostigaetsja posredstvom nagrevanija kolbasok v vanne s kipjashhej vodoj. Posle togo, kak kolbaski v techenie nochi ostyli i protein zatverdel, ih razrezali na lepeshki tolshhinoj 3/8 djujma, pomestili v banki i obluchili dozoj v 4,5 Mrad. Sterilizovannye oblucheniem produkty hranilis' v techenie 12 mesjacev pri temperature 72 Degree-Sign F, pri jetom periodicheski proizvodilas' ocenka kachestva, a takzhe posledstvij razlichnoj obrabotki. Jeta obrabotka vkljuchala upakovku v vakuume, vkljuchenie razlichnyh antiokislitelej i ispol'zovanie paketov dlja drevesnogo uglja. Neposredstvenno pered potrebleniem produkty pokryvalis' vzbitym testom i panirovochnymi suharjami i kak sleduet prozharivalis. Ocenka rybnyh pirozhkov proizvodilas' degustatorami, a takzhe putem izmerenija ob{sup e}ktivnyh pokazatelej, takih kak obshhie letuchie osnovanija, 2-tiobarbiturovoe kislotnoe chislo, pH i cvetnaja otrazhatel'naja sposobnost. Gruppy degustatorov (140- 170 chelovek) dali udovletvoritel'nuju ocenku vkusovyh kachestv produktov v.techenie 12 mesjacev hranenija pri temperature 72 Degree-Sign F. Hotja posle 12 mesjacev degustatory otdali predpochtenie neobluchennym kontrol'nym obrazcam, vse hranivshiesja obluchennye pirozhki poluchili polozhitel'nuju ocenku,po 9-ti bal'noj gedonicheskoj sisteme. Cvetnaja otrazhatel'naja sposobnost' sterilizovannyh oblucheniem morskih pishhevyh produktov ispol'zovalas' v kachestve merila, vyzvannogo oblucheniem potemnenija produktov i, kazhetsja, zavisit ot prodolzhitel'nosti hranenija. (author)

Construction and Operation of a Commercial Gamma-Ray Package-Sterilizing Plant; Construction et fonctionnement d'une installation industrielle pour la sterilisation d'articles sous emballage par les rayons gamma; Razrabotka i ehkspluatatsiya sbornoj ustanovki gamma-izlucheniya promyshlennogo tipa dlya sterilizatsii meditsinskikh materialov; Construccion y funcionamiento de una instalacion industrial para la esterilizacion gamma de articulos medicos empaquetados

Energy Technology Data Exchange (ETDEWEB)

Crawford, C. G. [Johnson' s Ethical Plastics Ltd., Slough (United Kingdom)

1963-11-15

The purpose of the paper is to describe the Co{sup 60} sterilizing plant now being operated commercially by Johnson's Ethical Plastics Limited, at Slough, England. This is a continuous process plant with a source of 72000 c and completely automatic operation. Based on experience gained by U.K.A.E.A. in their Package Irradiation Plant at Wantage, the present plant was designed specifically for sterilization of disposable plastic syringes and other medical products of similar bulk density. The plant has been in operation since November 1962. A description is given of the main features of its construction, including personnel safety devices, and method of loading the source rods. Operating experience is described including dosimetry, integration of the plant into a commercial undertaking as a production process, and bacteriological results. A short discussion on the economics of sterilizing by gamma radiation is given and an assessment of possible future applications of a plant of this type. (author) [French] Le memoire est consacre a la description de l'installation de sterilisation au cobalt-60, actuellement exploitee industriellement par la Johnson Ethical Plastics Ltd., a Slough (Angleterre). Cette installation, equipee d'une source de 72 000 c, fonctionne en continu et toutes les operations y sont automatiques. Fondee sur l'experience acquise par l'Autorite de l'energie atomique du Royaume-Uni dans son installation d'irradiation d'articles sous emballage, de Wantage, l'installation decrite est specialement destinee a la sterilisation de seringues en matieres plastiques et d'autres instruments medicaux non recuperables de densite apparente analogue. L'installation est en service depuis novembre 1962. Le memoire decrit ses principales caracteristiques, y compris les appareils de protection du personnel et les dispositifs de chargement des barreaux utilises comme sources. L'auteur fournit des donnees d'ordre pratique, notamment sur la dosimetrie, l'integration de l'installation dans une unite d e production exploitee par une entreprise commerciale et la bacteriologie. Il etudie brievement la rentabilite de la sterilisation par les rayons gamma et examine quelles sont les autres possibilites d'utilisation d'une installation de cette nature. (author) [Spanish] En la memoria se describe una instalacion de esterilizacion a base de {sup 60}Co, explotada comercialmente por la Johnson's Ethical Plastics Limited en Slough (Reino Unido). Se trata de una instalacion de tratamiento continuo totalmente automatica equipada con una fuente de 72 000 c. Aprovechando la experiencia adquirida por la Junta de Energfa Atomica del Reino Unido en su Package Irradiation Plant de Wantage, dicha instalacion fue concebida para esterilizar jeringas de material plastico y otros articulos medicos no recuperables de analoga densidad aparente. La instalacion viene funcionando desde noviembre de 1962. En la memoria se indican las principales caracteristicas de construccion, en especial los dispositivos para la seguridad del personal, y el metodo de carga de las varillas de cobalto. Se describe la experiencia adquirida, en particular en lo que atauee a la dosimetria, la integracion de la instalacion en el proceso productivo de una empresa comercial y los resultados bacteriologicos. Por ultimo, se examinan brevemente los aspectos economicos de la esterilizacion por irradiacion gamma y se evaluan las posibles aplicaciones de una instalacion de este tipo en el futuro. (author) [Russian] Tsel' nastoyashchej stat'i - opisanie ustanovki dlya oblucheniya s pomoshch'yu Co{sup 60}, na kotoroj v nastoyashchee vremya proizvoditsya v promyshlennykh masshtabakh sterilizatsiya meditsinskikh materialov (firma ''Dzhonsons ehtikal plastike'' v Slou, Angliya). Ustanovka nepreryvnogo dejstviya snabzhena istochnikom v 72 000 kyuri; vse operatsii polnost'yu avtomatizirovany. Na osnove opyta, poluchennogo v ehtoj oblasti pri ehkspluatatsii sbornoj radiatsionnoj ustanovki v Uontidzhe (pri Upravlenii po atomnoj ehnergii Soedinennogo Korolevstva), nastoyashchaya ustanovka byla sproektirovana spetsial'no dlya sterilizatsii plastmassovykh shpritsev i drugikh meditsinskikh materialov analogichnoj plotnosti. Ustanovka nachala funktsionirovat' s noyabrya 1962 goda. Dano opisanie osnovnykh kharakteristik i osobennostej e konstruktsii, priborov, obespechivayushchikh zashchitu obsluzhivayushchego personala, i metoda zagruzki sterzhnej. Opisan opyt ehkspluatatsii, vklyuchaya dozimetriyu, vklyuchenie ustanovki v edinyj tekhnologicheskij tsikl; privedeny rezul'taty bakteriologicheskikh issledovanij. Kratko obsuzhdeny ehkonomicheskie pokazateli pri sterilizatsii gamma-izlucheniem; dana otsenka vozmozhnosti primeneniya ustanovok podobnogo tipa v budushchem. (author)

Polymerization of Ethylene in Aqueous Silver-Salt Solution by Cobalt-60 Gamma Radiation; Polymerisation de l'ethylene dans une solution aqueuse de sel d'argent par des rayons gamma du cobalt-60; Polimerizatsiya ehtilena v vodnom rastvore serebryanoj soli pod dejstviem gamma-izlucheniya kobal'ta-60; Polimerizacion del etileno en solucion acuosa de sales de plata por los rayos gamma del cobalto-60.

Energy Technology Data Exchange (ETDEWEB)

Rosinger, S.; Mullner, S. [Farbwerke Hoechst AG, Hoechst (Germany)

1963-11-15

Ethylene, ethylene-propylene mixtures and propylene polymerize on irradiation in an aqueous silver-salt solution under moderate pressures. While oils or waxes are formed from propylene, ethylene yields solid polymers of high molecular weight. The yields obtained exceeded 25 g of polyethylene per litre per hour. With a dose rate of 7.1 x l0{sup 3} rad/hr this corresponds to a G-value (number of molecules reacted per 100 eV of energy absorbed) of 0.6 x 10{sup 5} in terms of the overall system and above 0.5 x 10{sup 6} in terms of dissolved ethylene. The polymer formation goes up with increasing ethylene pressure and increasing silver salt concentration. The silver salt solution can be re-used without a decrease in yield. The reaction is inhibited by traces of oxygen. The polymer yield is proportional to the absorbed dose if the dose rate is kept constant. The variation of yield with dose rate (J) equals J{sup 0,5-0.6}. The optimum temperature range is between 20 and 30{sup o}C. Below 0{sup o}C there is almost no reaction. The stirring velocity does not influence the yield. The specific gravity of the products is about 0.94g/cm{sup 3}; melting points between 126 and 131{sup o}C were observed. Infra-red absorption studies gave no evidence for C=C double bonds, C-O-H or C=0 groupings; a small number of C-O-C bonds were detected. There is a methyl-group content of 0.3%. The polymers are probably long branched chains and have viscosities between 5 and 10. (author) [French] L'ethylene, les melanges d'ethylene et de propylene et le propylene se polymerisent sous rayonnement dans une solution aqueuse de sel d'argent a des pressions moderees. Le propylene donne naissance a des produits a consistance d'huiles ou de cires alors que l'ethylene produit des polymeres solides de poids moleculaire eleve. Les rendements obtenus depassaient 25g de polyethylene par litre et par heure. Pour un debit de dose de 7,1 x 10{sup 3} rad/h, ceci correspond a une valeur de G (nombre de molecules reagissant pour 100 eV d'energie absorbee) de 0,6 x 10{sup 5} pour le systeme global et superieure a 0,5 x 10{sup 6} pour l'ethylene dissoute. La formation de polymeres augmente lorsque la pression de l'ethylene et la concentration du sel d'argent croissent. La solution de sel d'argent peut etre reutilisee sans que le rendement diminue. La reaction est inhibee par des traces d'oxygene. Le rendement en polymere est proportionnel a la dose absorbee si l e debit de dose est constant. La variation du rendement en fonction du debit de dose J est egale a J{sup 0,5-0,6}. La temperature optimum se situe entre 20 et 30{sup o}C, Au-dessous de 0{sup o}C, la reaction ne se produit pas. La vitesse d'agitation n'a aucune influence sur le rendement. Le poids specifique des produits est d'environ 0,94g /cm{sup 3}; les points de fusion se situent entre 126 et 131{sup o}C. Des etudes sur l'absorption infrarouge n'ont revele aucune double liaison C-C ni aucun groupe C-O-H ou C=O; on a decele un petit nombre de liaisons C-O-C. La proportion de groupes methyles est de 0,3%; les polymeres ont probablement de longues chaines ramifiees et leur vicsocite varie entre 5 et 10. (author) [Spanish] El etileno, las mezclas de etileno y propeno y el propeno polimerizan por irradiacion en solucion acuosa de sales de plata a presiones moderadas. Mientras que el propeno forma aceites y ceras, el etileno da origen a polimeros solidos de elevado peso molecular. Los rendimientos obtenidos fueron superiores a 25g de polietileno por litro y hora. Para una intensidad de dosis de 7,1 x 10{sup 3} rad/h, esto corresponde a un valor G (numero de moleculas que reaccionan por 100 eV de energia absorbida) de 0,6 x 10{sup 5} por el sistema global y superior a 0,5 x 10{sup 6} para el etileno disuelto. La formacion del polimero aumenta con la presion del etileno y la concentracion de las sales de plata. La solucion de sales de plata puede volverse a utilizar sin disminucion del rendimiento. La reaccion es inhibida por vestigios de oxigeno. La cantidad de polimero formada es proporcional a la dosis absorbida, para una intensidad de dosis constante. La variacion del rendimiento en funcion de l a intensidad de dosis, o sea J, es igual a J{sup 0,5-0,6}. Eliintervalo optimo de temperaturas es el comprendido entre 20 y 30{sup o}C. Por debajo de 0{sup o}C, la reaccion deja de verificarse. La velocidad de agitacion no influye en el rendimiento. El peso especifico de los productos es del orden de 0,94g/cm{sup 3}; se han observado puntos de fusion que oscilan entre 126 y 131{sup o}C. El analisis por absorcion de rayos infrarrojos no indica la existencia de dobles enlaces C=C ni de grupos C-O-H o C=O; se ha detectado un pequeno numero de enlaces C-O-C. El contenido de grupos metilo es del 0,3%. Los polimeros estan probablemente constituidos por largas cadenas ramificadas y presentan viscosidades comprendidas entre 5 y 10. (author) [Russian] Ehtilen, ehtilen-propilenovye smesi i propilen polimerizovali pod oblucheniem v vodnykh rastvorakh serebryanykh solej pri umerennom davlenii. V to vremya kak iz propilena poluchali masla ili voski, ehtilen daval tverdye polimery s vysokim molekulyarnym vesom. Vykhod prevysil 25 g poliehtilena na 1 litr v chas. Pri moshchnosti dozy 7,1 x 10{sup 3} rad/chas ehto sootvetstvuet znacheniyu G (chislo molekul, proreagirovavshikh na kazhdye 100 ehv pogloshchennoj ehnergii), ravnomu 0,6 x 10{sup 5} pri uchete vsej sistemy i prevyshaet 0,5 x 10{sup 6} pri uchete rastvorennogo ehtilena. Obrazovanie polimera rastet pri uvelichenii davleniya i kontsentratsii serebryanoj soli. Rastvor serebryanoj soli mozhno ispol'zovat' povtorno, ne umen'shaya vykhoda polimera. Reaktsiyu ingibiruyut sledy kisloroda. Vykhod polimera proportsionalen pogloshchennoj doze pri postoyanstve moshchnosti dozy. Izmenenie vykhoda v za- visimosti ot moshchnosti dozy (J) ravno J{sup o,5-o,6}. Optimum temperatury lezhit v intervale 20 - 30{sup o}C. Nizhe 0{sup o}C reaktsiya pochti ne idet. Skorost' peremeshivaniya ne vliyaet na vykhod. Udel'nyj ves produkta raven pochti 0,94g/cm{sup 3}, tochki plavleniya lezhat mezhdu 126 i 131{sup o}C. Infrakrasnye spektry pogloshcheniya ne pokazali nalichiya dvojnykh svyazej C=C i grupp C-O-H ili C=0; byli obnaruzheny v ne- bol'shom kolichestve svyazi C-O-C. Soderzhanie metil'nykh grupp sostavlyaet 0,3%. Polimery, po-vidimomu, sostoyat iz dlinnykh razvetvlennykh tsepej, i znacheniya vyazkosti lezhat mezhdu 5 i 10. (author)

The Northern Apennines palynological record as a contribute for the reconstruction of the Messinian palaeoenvironments

Science.gov (United States)

Bertini, Adele

2006-06-01

and eustatism). In contrast organic-walled dinoflagellate cysts exclude significant modifications in aquatic settings (insaturation of either open marine or brackish conditions). In the latter, a later change is marked by the arrival of Impagidinium (?) sp. 1., a species here referred instead to Caspidinium rugosum, about 7 m below the first colombaccio. This occurrence together with the spread of Pediastrum indicates a freshwater dilution i.e. the "Lago-Mare" event during wetter climatic conditions on the adjacent landmass (increase of Tsuga and Cedrus). The successive arrival and/or dominance of other "Paratethyan" taxa such as I. (?) sp. 2, I. (?) sp. 3 and Galeacysta etrusca indicate highly variable water environments (marine vs. continental water inputs) during the deposition of the uppermost post-evaporitic deposits. The Lago-Mare is stratigraphically sandwiched between an ash layer (130 m below) dated at 5.5 Ma and the beginning of the Pliocene where a peak of Impagidinium patulum marks the onset of open marine conditions. The dominant humid, subtropical to warm temperate climate indicates differences in both temperature and moisture values with respect to the coeval southern sections, revealing climatic gradients within the Mediterranean, at least from the Messinian. No dramatic vegetation and climate changes have been recorded during the MSC; major changes occurred later as indicated by the palynological record from 2.6 Ma. This palynostratigraphic record is a good reference for more recent models of the development of the MSC and for establishing time-relationships between the Apennine and Sicilian successions.

The Technology and Applications of Large Fission Product Beta Sources; Technologie et applications des grandes sources beta de fission; Tekhnologiya i primenenie krupnykh istochnikov beta-izluchenij, ispuskaemykh produktami deleniya; Tecnologia y utilizacion de los productos de fision como fuentes de irradiacion beta de elevada intensidad

Energy Technology Data Exchange (ETDEWEB)

Silverman, Joseph [Radiation Applications Incorporated (United States)

1960-07-15

) [Russian] Beta-izluchatel i ne vkhodili ran'she v raschet v kachestve krupnykh istochnikov izlucheniya, tak kak v proshlom predstavlyayushchie interes protsessy oblucheniya osnovyvalis' na ispol'zovanii chastits, obladayushchikh sposobnost'yu glubokogo proniknoveniya; poehtomu glavnoe vnimanie sosredotochivalos' na ispol'zovanii gamma-izluchenij i iskusstvenno uskorennykh ehlektronov. Okolo chetyrekh let tomu nazad stalo ochevidnym, chto otkryvaetsya shirokaya oblast' vozmozhnykh primenenij, svyazannykh s poverkhnostnym oblucheniem, kak naprimer, izmenenie poverkhnosti obrazovavshegos ya sloya plastmassy putem sopolimerizatsionnogo narashchivaniya i poverkhnostnoj pasterizatsii pishchevykh produktov. Dlya ehtikh primenenij proniknovenie v glubinu yavlyaetsya neehkonomnym, a vozmozhno i vrednym. Est'eshche dve drugie oblasti, v kotorykh proizvedennye mekhanicheskim putem ehlektrony ne ochen' podkhodyat: khimicheskij sintez v nakhodyashchikhsya pod davleniem sosudakh s primeneniem oblucheniya i nekotorye vidy tsepnykh reaktsij so svobodnymi radikalami, dlya kotorykh proizvoditel'nost ' na kilovatt umen'shaetsya proportsional'no kvadratnomu kornyu moshchnosti dozy. Istochniki beta-izluchenij s shirokim polem pokazali ochevidnye potentsial'ny e preimushchestva dlya vsekh ehtikh operatsij i poskol'ku oni poluchayutsya v bol'shikh kolichestvakh za schet protsessov deleniya, to predstavlyalos ' tselesoobrazny m sdelat' tshchatel'nuyu pereotsenku vozmozhnostej ikh primeneniya. Vvidu ehtogo pod pokrovitel'stvom Komissii po atomnoj ehnergii SSHA bylo proizvedeno issledovanie primenenij i tekhnologii istochnikov beta-izluchenij, ispuskaemykh produktami deleniya. EHto issledovanie privelo k sleduyushchim rezul'tatam: 1. Otkryvayutsya perspektivny e vozmozhnosti primeneniya v kommercheskom masshtabe istochnikov beta-izluchenij, ispuskaemykh produktami deleniya, v oblasti oblucheniya produktov, v osobennosti dlya izmeneniya putem sopolimerizatsionnogo narashchivaniya obrazovavshikhsya

X-Ray Equipment for Food Irradiation; Appareil a Rayons X pour Lirradiation des Denrees Alimentaires; Rentgenovskoe oborudovanie dlya oblucheniya pishchevykh produktov; Equipo de Rayos X para Irradiacion de Alimentos

Energy Technology Data Exchange (ETDEWEB)

Rajewsky, B. [Max Planck Institut fuer Biophysik, Frankfurt A. M., Federal Republic of Germany (Germany)

1966-11-15

con una intensidad de 2 A y una tension de 100 kV como maximo. La.dosis de irradiacion asciende a 10{sup 7} R/min. Utilizando una cinta transportadora continua ios tubos permiten irradiar una gran cantidad de material. Se describe el correspondiente equipo industrial realizado hasta la fecha. (author) [Russian] Neobhodimost' razrabotki oborudovanija s ochen' vysokim vyhodom rentgenovskih luchej dlja issledovanij razlichnyh problem radiacionnoj biofiziki i radiacionnoj biologii stala ochevidnoj uzhe v nachale sorokovyh godov. Jeto oborudovanie pozvolilo poluchat' bolee vysokuju dozu, chem mogli dat' sushhestvovavshie v to vremja tehnicheskie konstrukcii. Takoe oborudovanie bylo razrabotano v 1950- 1953 godah avtorom i ego kollegami v Institute biofiziki Maksa Planka i s togo vremeni ispol'zovalos' dlja nauchnyh issledovanij. Pozdnee stalo jasno, chto jeti rentgenovskie mashiny ochen' podhodjat takzhe dlja celej sterilizacii i dezinfekcii medikamentov, produktov pitanija i drugih materialov. V Institute biofiziki Maksa Planka ispol'zujutsja tri vida takogo oborudovanija. Posle sozdanija rentgenovskogo oborudovanija AEG na 120 kv i 500 ma promyshlennost' vosprinjala jeti idei i v nastojashhee vremja postepenno pretvorjaet ih v zhizn'. Oborudovanie, sozdannoe avtorom i ego kollegami, imeet tri razlichnyh vida rentgenovskih trubok, kotorye mozhno soedinjat' s transformatorom vysokogo naprjazhenija 240 kv/a. Cherez jeti trubki nepreryvnr ili v techenie korotkogo vremeni propuskaetsja tok v 2 a pri naprjazhenii do 100 kv. Doza radiacii sostavljaet do 10{sup 7} rentgen/min. Vidy trubok pozvoljajut nepreryvno obluchat' bol'shie kolichestva materiala. Daetsja opisanie sootvetstvujushhego promyshlennogo oborudovanija, sozdannogo do sih por. (author)

Difference in Injury Mode, Dose-Rate Dependence and RBE of 730-Mev Protons, 100-KVp X-Rays and 250-KVp X-Rays; Differences dans le Type de Lesion, l'Importance du Debit de Dose et l'EBR entre les Protons de 730 Mev, les Rayons X de 100 Kv-Crete et les Rayons X de 250 Kv-Crete; Razlichiya kharaktera porazheniya, zavisimosti ot moshchnosti dozy i obeh protonov s ehnergiej 730 mehv i rentgenovskikh luchej s pikovym napryazheniem 100 i 250 kv; Diferencias en la Modalidad de La Lesion, la Relacion con la Intensidad de Dosis y la EBR de los Protones de 730 Mev, y los Rayos X de 100 Kvp Y de 250 Kvp

Energy Technology Data Exchange (ETDEWEB)

Sondhaus, C. A.; Wallace, R. W.; Lyman, J. T.; Kase, K. W.; Steward, P. G. [University of California Lawrence Radiation Laboratory Berkeley (United States)

1964-03-15

meme effet du debit de doee que dans l'exposition a bas TLE. Les auteurs examinent les consequences pratiques de la distribution de la dose et du debit de dose. (author) [Spanish] Los autores estudiaron la mortalidad a los 6, 12 y 30 d en ratones blancos machos de la variedad Swiss Webster expuestos a protones de 730 MeV, a rayos X de 250 kVp y a rayos X de 100 kVp, con diferentes intensidades de dosis. En los ratones irradiados con protones, predomino la muerte por sindrome gastrointestinal, a los 6 a 8 d, con dosis de 100 y 1000 rad/min, y el efecto letal fue mas intenso con la intensidad de dosis mayor. En la exposicion a los rayos X, predomino la muerte por sindrome hematopoyetico, a los 12 a 14 d, con efectos de la intensidad de dosis semejantes a los del caso anterior. Comprobaron los autores que la EBR de los protones para la DL{sub 50} a los 30 d, comparada con la de los rayos X de 250 kVp, asciende a 0,8; en cuanto a la EBR para la DL{sub 50} a los 6 d, es 1,2, con igual intensidad de dosis (100 rad/min). Atribuyen la diferencia de modalidad de la lesion a las distintas distribuciones de la dosis en los tejidos. En la EBR de los protones para la muerte por sindrome intestinal a los 6 d , que asume un valor elevado pero variable, se manifiesta al parecer el efecto de intensidad de doeis caracteristico de las exposiciones de baja TLE. Los autores examinan las consecuencias practicas de los factores de distribucion de dosis y de la intensidad de dosis senalados. (author) [Russian] Izuchalas' smertnost' samcov belyh myshej linii Sviss Vebster, podvergnutyh oblucheniju protonami s jenergiej 730 Mjev, rentgenovskimi luchami s pikovym naprjazheniem 250 i 100 kv pri razlichnyh moshhnostjah dozy. Myshi, obluchennye protonami, pogibali na shestoj- vos'moj den', glavnym obrazom v rezul'tate zheludochno-kishechnyh porazhenij posle obluchenija 100 i 1000 rad/min, prichem smertnost' povyshalas' s povysheniem moshhnosti dozy. Posle rentgenovskogo obluchenija zhivotnye

A Procedure for the Determination of Alpha-Emitting Plutonium in Urine Using a Solid-State Counter; Methode de Determination du Plutonium Emetteur Alpha Present dans l'Urine, au Moyen d'un Compteur a Semi-Conducteurs; Metod opredeleniya al'fa-izlucheniya plutoniya v moche s pomoshch'yu poluprovodnikovogo schetchika; Procedimiento para Determinar la Actividad Alfa del Plutonio en la Orina con Ayuda de un Contador de Estado Solido

Energy Technology Data Exchange (ETDEWEB)

Sandalls, F. J.; Morgan, A. [Health Physics and Medical Division, Atomic Energy Research Establishment, Harwell (United Kingdom)

1964-10-15

A method for the routine determination of alpha-emitting plutonium in urine is described. In evolving this procedure various techniques for concentrating, purifying and electro depositing plutonium were compared, and these investigations are summarized. In the procedure finally adopted, urine is wet-ashed and the residue dissolved in hydrochloric acid. Plutonium (IV) is co-precipitated with iron cupferride from this solution and extracted into chloroform. After evaporation of the chloroform, the residue is oxidized, dissolved in hydrochloric acid and the iron extracted into di-isopropyl ether. The aqueous phase containing the plutonium is evaporated and dissolved in an acid ammonium sulphate solution from which the plutonium is electrodeposited onto stainless steel. Quantitative recoveries are obtained over the electrodeposition stage and on overall recovery of 84 {+-} 7%. The electrodeposited plutonium is counted with a solid-state (silicon junction diode) detector in a counter developed for this purpose. The low inherent background of this type of counter is effectively reduced still further by counting only those alpha particles with energy in the 4.2 - 5.4 MeV range. The good resolution which can be obtained with thin electrodeposited sources of plutonium enables this narrow channel to be used with only small losses in counting efficiency. By counting over this restricted energy range, the blank activity arising from reagents and incomplete removal of alpha-emitting contaminants in urine is also reduced by a factor of two, to just over 0.01 pc/24-h sample. The limit of detection with this method is about 0.025 pc of Pu{sup 239}. (author) [French] Les auteurs exposent une methode pour la determination courante du plutonium emetteur alpha present dans l'urine. Pour mettre au point cette methode, ils ont compare diverse procedes de concentration, de purification et de depot electrolytique du plutonium; les resultats de ces recherches sont resumes dans le memoire. La methpde qu'ils ont finalement adoptee consiste a incinerer l'urine et a dissoudre le residu dans de l'acide chlorhydrique. A partir de cette solution,' le plutonium (IV) est coprecipite avec du cupferrate de fer et extrait au moyen de chloroforme. Apres evaporation de celui-ci, le residu est oxyde et dissous dans l'acide chlorhydrique, puis le fer est extrait au moyen d'ether di-isopropy- lique. La phase aqueuse contenant le plutonium est evaporee et dissoute dans une solution de sulfate acide d'ammonium, d'ou le plutonium est depose par electrolyse sur de l'acier inoxydable. Au stade du depot . electrolytique, on recueille dans l'ensemble 84 {+-} 7% du plutonium contenu. Le plutonium depose par electrolyse est mesure au moyen d'un detecteur a semi-conducteur (diode a jonction au silicium) dans un compteur concu a cette fin. Le faible mouvement propre de ce type de compteur est encore efficacement reduit si l'on ne compte que les particules alpha ayant des energies comprises entre 4,2 et 5,4 MeV. La bonne resolution que l'on peut obtenir avec de minces couches de plutonium deposees par electrolyse permet d'utiliser ce canal etroit en ne faisant que de faibles pertes de rendement de comptage. En ne comptant que dans cette gamma d'energies peu etendue, l'activite due a la presence de reactifs et d'autres agents de contamination emetteurs alpha residuels dans l'urine, qui n'est pas entierement decontaminee, se trouve egalement reduite de moitie et atteint un peu plus de 0,01 pc par echantillon preleve sur les urines recueillies pendant 24 h. La limite de detection a l'aide de cette methode est d'environ 0, 025 pc de {sup 239}Pu. (author) [Spanish] La memoria describe un metodo para determinaciones corrientes de plutonio en la orina. Tambien resume las investigaciones que llevaron a establecer este procedimiento y en las que se compararon diversas tecnicas de concentracion, purificacion y deposito electrolitico del plutonio. Con arreglo al procedimiento adoptado en definitiva, la orina se calcina en humedo y el residuo se disuelve con acido clorhidrico. El plutonio (IV) presente en la solucion asi obtenida se coprecipita con cupferrato de hierro y se extrae con cloroformo. Una vez evaporado este,, se oxida el residuo, se disuelve en acido clorhidrico y el hierro se extrae con eter diisopropflico. Seguidamente se evapora a sequedad la fase acuosa que contiene, al plutonio y se disuelve en una solucion acida de sulfato amonico desde la cual se separa el plutonio por deposito electrolitico sobre acero inoxidable. El rendimiento de esta ultima etapa es cuantitativo, siendo de 84 {+-} 7% para el proceso en conjunto. . El plutonio electrodepositado se recuenta con un detector de estado solido (diode de union de silicio) en un contador especialmente construido para este fin. La baja actividad de fondo inherente de este tipo de contadores puede disminuirse aun mas contando solamente las particulas alfa de energia comprendida entre 4.2 y 5,4 MeV. El buen poder de resolucion que se obtiene con capas delgadas de plutonio electrodepositado permite emplear un canal tan estrecho sin que la eficacia de recuento disminuya apreciablemente. Al efectuar el recuento en este intervalo restringido, la actividad de fondo debida a los reactivos y a la eliminacion incompleta de las impurezas de emisores alfa de la orina queda reducida tambien a la mitad, esto es, a un valor del orden de 0,01 pcuries por muestra de 24 horas. El limite de deteccion mediante este metodo es aproximadamente de 0,025 pc de {sup 239}Pu. (author) [Russian] Opisan metod prakticheskogo'opredelenija al'fa-izluchenija plutonija v moche. Pri razrabotke jetogo metoda sravnivalis' razlichnye metody koncentrirovanija, ochistki i jelektroliticheskogo osazhdenija plutonija ; podvoditsja itog jetih issledovanij. Soglasno prinjatomu v konechnom itoge metodu mochu podvergajut vlazhnomu ozoleniju, osadok rastvorjajut v soljanoj kislote. Plutonij (IV) podvergajut sovmestnomu osazhdeniju s kupferronatom zheleza iz jetogo rastvora i jekstragirujut hloroformom. Posle vyparivanija hloroformom osadok okisljajut, rastvorjajut v soljanoj kislote i jekstragirujut zhelezo di- izopropilovym jefirom. Vodnuju fazu, soderzhashhuju plutonij, vyparivajut i rastvorjajut v kislom sul'fate ammonija, iz kotorogo plutonij osazhdajut jelektroliticheski na nerzhavejushhej stali. Kolichestvennye vosstanovlenija na stadii jelektroliticheskogo osazhdenija dali 84 {+-} 7% Osazhdennyj plutonij podschityvali s pomoshh'ju diodnogo (tverdogo s kremnevym soedineniem) schetchika,sozdannogo dlja jetoj celi. Nizkij estestvennyj fon schetchika jetogo tipa byl jeffektivno snizhen putem podscheta lish' teh al'fa-chastic, kotor''ge imejut jenergiju 4.2 - 5,4 Mjev. Horoshee razreshenie, poluchaemoe s pomoshh'ju tonkogo jelektroosazhdennogo istochnika plutonija3obespechivaet vozmozhnost' ochen' malyh poter' jeffektivnosti scheta v jetom uzkom kanale. Pri schete vne'jetoj ogranichennoj oblasti jenergii kontrol'naja aktivnost', sozdavaemaja reaktivami i nepolnoj ochistkoj ot drugih al'fa-izluchatelej v moche, takzhe snizhaetsja na faktor porjadka 2, nemnogo vyshe 0,01 mkmkkjuri v-techenie 24 chasov. Predel obnaruzhenija s pomoshh'ju jetogo metoda sostavljaet okolo 0,025 mkmkkjuri plutonija-239. (author)

Meteorites as space probes for cosmic rays; Les meteorites en tant que sondes spatiales pour les rayons cosmiques; Meteority v kachestve prob mezhplanetnogo prostranstva dlya izucheniya kosmicheskikh luchej; Los meteoritos como sondas espaciales para evaluar la actividad inducida por los rayos cosmicos

Energy Technology Data Exchange (ETDEWEB)

Schaeffer, O A; Stoenner, R W; Davis, R Jr [Chemistry Department, Brookhaven National Laboratory, Upton, L. I., NY (United States)

1962-01-15

'activite imputable a l'argon-37 (periode: 35 jours) et a l'argon-39 (periode: 325 ans). Ils comparent ces activites relatives aux taux de production de ces isotopes que l'on obtient en bombardant un echantillon de la meteorite avec des protons ayant une energie de 3 GeV. Les auteurs concluent que, dans les limites d'erreur, le flux de rayons cosmiques est le meme dans la ceinture asteroide que dans le voisinage de l'orbite terrestre. (author) [Spanish] Para determinar la constancia espacial de la radiacion cosmica de elevada energia en el interior del sistema solar, los autores midieron la radiactividad, inducida por los rayos cosmicos, de un elemento de periodo corto y de un elemento de periodo largo en un meteorito caido recientemente. El experimento se basa en el hecho de que los meteoritos siguen orbitas muy excetricas y, por ello, pueden ser utilizados como sondas espaciales en la region situada entre la orbita terrestre y el cinturon de asteroides. La actividad de periodo corto se produce mientras el meteorito se encuentra en las proximidades de la orbita terrestre, en tanto que la actividad de periodo largo es inducida en toda la orbita descrita por el meteorito. Los autores efectuaron las mediciones en el condrito Hamlet que cayo en Indiana el 13 de octubre de 1.959. Evaluaron las actividades astribuibles al argon-37 (periodo: 35 dias) y al argon-39 (periodo: 325 anos). Compararon los valores relativos de estas actividades con los indices de produccion de esos isotopos que se alcanzan bombardeando una muestra del meteorito con protones de 3 GeV. Se llega a la conclusion de que la intensidad de la radiacion cosmica es igual, dentro de los limites de error, en el cinturon de asteroides que en las proximidades de la orbita terrestre. (author) [Russian] Byl proizveden opyt ispytaniya prostranstvennogo postoyanstva kosmicheskogo izlucheniya vysokikh ehnergij v solnechnoj sisteme putem zamera iskusstvennoj korotkozhivushchej i dol- gozhivushchej radioaktivnosti kosmicheskikh

Neutron activation analysis of ancient silver coins; Analyse d'anciennes pieces d'argent par activation neutronique; Nejtronozyj aktivatsionnyj analiz starinnykh serebryanykh monet; Analisis de antiguas monedas de plata por activacion neutronica

Energy Technology Data Exchange (ETDEWEB)

Aitken, Martin J; Emeleus, Vera M; Hall, Edward T [Research Laboratory for Archaeology and the History of Art, University of Oxford (United Kingdom); Kraay, Colin M [Heberden Coin Room, Ashmolean Museum, University of Oxford (United Kingdom)

1962-01-15

ehry bylo opredeleno pri pomoshchi gamma-spektrometra posle nejtronnoj aktivatsii monet. Byli izucheny monety vos'mi gorodov i korolevstv. V razlichnykh gruppakh monet v srednem soderzhalos' zolota ot 0,02 % do 0,3 % i medi 0,1 % do 10 %. Byli polucheny dokazatel'stva torgovykh svyazej, prednamerennogo obestsenivaniya monet, a takzhe bylo obnaruzheno neskol'ko poserebrennykh monet, o chem ranee ne podozrevali. Soderzhanie zolota v monetakh opredelyalos' posredstvom izmereniya intensivnosti gamma-luchej (0,411 mehv) ot zolota-198 (2,96 dnej), soderzhanie medi - s pomoshch'yu izmereniya izlucheniya pozitronnoj annigilyatsii (0,511 mehv) ot medi-64 (12,8 chasov), a soderzhanie serebra - posredstvom izmereniya intensivnosti gamma-luchej (0,884 mehv) ot serebra- 110t (253 dnya). Dlya proverki identichnosti provodilis' izmereniya radioaktivnogo raspada. Metod ispol'zovaniya krivykh obshchego gamma-aktivnogo raspada sam po sebe yavlyaetsya nedostatochno chuvstvitel'nym. Dlya bolee tochnoj raboty podcherkivaetsya vazhnost' primeneniya priblizitel'no tochnykh standartov. (author)

Use of radioisotopes in the systematic analysis of impurities in metals of very high purity; Application des radioisotopes a l'analyse systematique des impuretes dans les metaux de tres haute purete; Primenenie radioizotopov v sistematicheskom analize primesej v vysokochistykh metallakh; Aplicacion de los radioelementos al analisis sistematico de las impurezas en los metales muy puros

Energy Technology Data Exchange (ETDEWEB)

Albert, Philippe; Gaittet, Jean [Centre d' Etudes de Chimie Metallurgique (C.N.R.S.), Vitry (France)

1962-01-15

insistiran especialmente en los resultados y en las consecuencias de los analisis por ellos realizados. (author) [Russian] tsentratsiya primesej dostigaet poryadka 10{sup -6} - 10{sup -8}. EHti metally izgotovlyayutsya v nebol'shikh kolichestvakh, i ochen' vazhno umet' tochno opredelyat' kolichestvennym analizom ochen' bol'shoe chislo ehlementov v odnoj probe. Sistematicheskij analiz alyuminiya i zheleza pri pomoshchi nejtronnogo oblucheniya pozvolil nam proizvesti kolichestvennyj analiz 45 ehlementov v odnoj probe poryadka odnogo gramma. EHtot analiz bol'shogo chisla primesej stal vozmozhnym lish' blagodarya kaskadnomu razdeleniyu poluchivshikhsya vo vremya oblucheniya radioizotopov na bolee chem 40 analiticheskikh fraktsij. Zatem bol'shinstvo radioizotopov izoliruetsya v chistom vide radiokhimicheskim putem, a ikh identifikatsiya dostigaetsya putem odnovremennogo izucheniya perioda ikh radioaktivnogo raspada i spektra ikh gamma-izlucheniya. Odnako, dopolnyaya ehtot sistematicheskij analiz k olichestvennym analizom nekotorykh ehlementov v otdel'noj probe, mozhno opredelyat' a Ktivatsionnym metodom okolo 60 ehlementov, libo obluchaya ikh nejtronami (sera, fosfor, khlor, barij...), libo pri pomoshchi reaktsij, vyzvannykh nejtronami (uglerod i bor). V nashem doklade my namereny osobo ostanovit'sya na rezul'tatakh i posledstviyakh nashikh analizov. (author)

The production of radioisotopes with a betatron using an internal bombarding technique; Production de radioisotopes par bombardement interne dans un betatron; Proizvodstvo radioizotopov s pomoshch'yu betatrona s ispol'zovaniem metoda vnutrennej bombardirovki; Obtencion de radioisotopos por bombardeo interno en el betatron

Energy Technology Data Exchange (ETDEWEB)

Morinaga, H [Department of Physics, Tohoku University, Sendai (Japan)

1962-01-15

pueden servir para la obtencion de isotopos. Con frecuencia es conveniente emplear isotopos de periodo corto debido a su rapida desintegracion, al hecho de que emitan radiaciones de alta energia y a la facilidad con que pueden obtenerse incluso sin necesidad de poseer conocimientos especiales. (author) [Russian] Razrabotan i uspeshno ispol'zuetsya novyj metod proizvodstva radioizotopov s vysokoj udel'noj aktivnost'yu s pomoshch'yu betatrona. Podvergaemye aktivatsii materialy pomeshchayutsya vnutr' vakuumnoj kamery betatrona v kontse slepogo tsilindra, ustanovlennogo izvne; takim obrazom, proby podvergayutsya bombardirovke pri odnoj atmosfere neposredstvenno za mishen'yu tormoznogo izlucheniya, gde intensivnost' radiatsii chrezvychajno vysoka. Aktivnost' pri nasyshchenii Cu{sup 62}, vyzvannaya v nebol'shoj chastitse medi, prevyshala 1 millikyuri, i poluchaemaya naivysshaya udel'naya aktivnost' priblizitel'no v 500 raz prevyshala aktivnost', vyzvannuyu v obychnom ustrojstve. Do sikh por ehtot metod vnutrennej misheni ispol'zuetsya tol'ko dlya rabot v oblasti yadernoj spektroskopii; bylo ustanovleno vosem' novykh vidov radioaktivnykh izotopov (Co{sup 63}, Ga{sup 75}, As{sup 81}, In{sup 121}, In{sup 123}, Tm{sup 173}, Tm{sup 175} i Ac{sup 231}). Gibkost' takogo metoda bombardirovki otkryvaet novye vozmozhnosti, t.k. meditsinskij, promyshlennyj, a takzhe issledovatel'skij betatrony mogut ispol'zovat'sya dlya proizvodstva izotopov. Korotkozhivushchie izotopy, kotorye chasto yavlyayutsya bolee udobnymi pri razlichnykh vidakh primeneniya vsledstvie ikh bystrogo raspada i obychno vysokoj ehnergii radiatsii, mogut byt' bystro polucheny bez kakogo-libo dopolnitel'nogo umeniya. (author)

The Use of Ionizing Radiation in the Vulcanization of Silicon Rubber; Utilisation des radiations ionisantes pour la vulcanisation du caoutchouc au silicone; Ispol'zovanie ioniziruyushchikh izluchenij dlya vulkanizatsii silikonovogo kauchuka; Empleo de las radiaciones ionizantes en la vulcanizacion del caucho de siliconas

Energy Technology Data Exchange (ETDEWEB)

Kuzminsky, A S; Nikitina, T S; Oksentevich, L A [Rubber Research Institute, Moscow, Union of Soviet Socialist Republics (Russian Federation)

1960-07-15

temperaturas (150{sup o}, 200{sup o} y 250{sup o}). La irradiacion permite disminuir la temperatura de vulcanizacion y prescindir de un almacenamiento prolongado a temperatura regulada, que de otro modo es necesario despues de la vulcanizacion. El negro de humo puede utilizarse como material de carga para el caucho vulcanizado con arreglo al nuevo metodo. Los autores llegan a la conclusion de que el empleo de las radiaciones ionizantes se traduce en una simplificacion de la tecnologia de la vulcanizacion del caucho de siliconas y en un mejoramiento de las propiedades de los productos obtenidos. (author) [Russian] Osnovnaya tsel' raboty - podrobnoe izuchenie svojstv materialov, poluchaemykh v rezul'tate oblucheniya smesej polidimetil-siloksanovogo kauchuka s razlichnymi napolnitelyami (spetsial'naya kremnekislota, dvuokis' titana, kanal'naya, pechnaya i lampovaya sazha). Obluchenie provodilos' na moshchnoj rentgenovskoj ustanovke i na istochnike {gamma}-izlucheniya So{sup 60} aktivnost'yu 20 000 g-ehkv. radiya. Otsenena otnositel'naya skorost' obrazovaniya prostranstvennoj setki vulkanizatov (po velichine ravnovesnogo modulya i maksimal'noj stepeni nabukhaniya v benzole). Rassmotreno izmenenie soprotivleniya razryvu i otnositel'nogo udlineniya v protsesse oblucheniya. Vybrany optimal'nye rezhimy vulkanizatsii i opredeleny osnovnye fiziko-mekhanicheskie pokazateli vulkanizatov. Issledovano izmenenie svojstv radiatsionnykh vulkanizatov v protsesse teplovogo stareniya pri razlichnykh temperaturakh (150, 200 i 250{sup o}). Radiatsionnaya vulkanizatsiya isklyuchaet neobkhodimost ' provedeniya protsessa pri vysokikh temperaturakh i dlitel'noe termostatirovanie posle vulkanizatsii . Novyj sposob vulkanizatsii pozvolyaet primenyat' v kachestve napolnitelej uglerodnye sazhi. Ispol'zovanie ioniziruyushchikh izluchenij pozvolyaet uprostit' tekhnologiyu vulkanizatsii silikonovogo kauchuka i uluchshit' svojstva vulkanizatov. (author)

Radioactive apparatus for measuring the thickness of hot sheet-metal; Jauge d'epaisseur radioactive pour la mesure a chaud de plaques metalliques; Radioaktivnyj izmeritel' tolshchiny goryachego listovogo prokata; Calibrador radiactivo para la medicion en caliente de chapas

Energy Technology Data Exchange (ETDEWEB)

Vasichev, B N; Latyshev, V K; Pliskin, Yu S; Felinger, A K

1962-01-15

}Cs de actividad equivalente a la de 9,2 g de radio, es posible medir el espesor de chapas calientes del espesor mencionado con un margen de aproximacion de {+-} 0,1 mm. El aparato efectua las mediciones a razon de una por segundo y funciona satisfactoriamente en las condiciones que exigen las operaciones de laminado. (author) [Russian] Dlya polucheniya vysokoj tochnosti izmerenij v usloviyakh prokatnogo proizvodstva vybran dinamicheskij metod kompensatsii, pri kotorom parametr sravneniya prokhodit vse znacheniya v izmeryaemoj oblasti, a nul'-organ otmechaet lish' moment ravenstva izmeryaemogo parametra i parametra sravneniya. Ispol'zovanie ehtogo metoda dalo vozmozhnost' osvobodit'sya ot mekhanicheskikh obratnykh svyazej i peremennykh po svoemu kharakteru peremeshchenij, svojstvennykh metodu staticheskoj kompensatsii, i sozdat' pribor, udovletvoryayushchij kak trebovaniyam tochnosti, tak i bystrodejstviya v slozhnykh usloviyakh prokatnogo proizvodstva. V doklade izlagaetsya printsipial'naya skhema pribora dlya kontrolya tolshchiny lista v protsesse prokatki, rassmatrivayutsya faktory, vliyayushchie na tochnost' izmereniya tolshchiny goryachego lista (temperatura, volnistost', nalichie vody na poverkhnosti lista, material lista i ego polozhenie na rol'gange). Opisyvaetsya konstruktivnoe vypolnenie opytno-promyshlennogo obraztsa pribora na diapazone tolshchin ot 14 mm do 44 mm. Promyshlennye ispytaniya pribora pokazali, chto pri istochnike izlucheniya Cs{sup 137} aktivnost'yu 9,2 g-ehkv. radiya tochnost' izmereniya tolshchiny goryachego lista v ukazannom vyshe diapazone sostavlyaet {+-}0,1 mm. Bystrodejstvie pribora - odno izmerenie v sekundu. Pribor nadezhno rabotaet v usloviyakh prokatnogo tsekha. (author)

The use of radioactive inserts in the study of metal deformation during tube-making processes; Emploi de fils metalliques radioactifs pour l'etude des deformations des metaux pendant la fabrication de tubes; Ispol'zovanie radioaktivnykh vtulok dlya izucheniya deformatsii metallov pri protsesse izgotovleniya trub; Empleo de insertos radiactivos en el estudio de la deformacion de los metales durante la fabricacion de tubos

Energy Technology Data Exchange (ETDEWEB)

Davison, W H.T. [Tube Investments Research Laboratories, Cambridge (United Kingdom)

1962-01-15

ot ehnergii gamma-izlucheniya, konstruk- tsii kollimatora i diskriminatsii ehnergii. (author)

Electronic methods for discriminating scintillation shapes; Methodes electroniques de discrimination des formes des impulsions issues de scintillateurs; Ehlektronnye metody diskriminatsii form stsintillyatsii; Metodos electronicos de discriminacion de forma de impulsos de centelleo

Energy Technology Data Exchange (ETDEWEB)

Forte, M; Konsta, A; Maranzana, C [European Atomic Energy Community, CCR, ISPRA (Italy)

1962-04-15

hasta impulsos debiles, de unas cuantas decenas de fotoelectrones, y la discriminacion de fragmentos emitidos por captura neutronica en liquidos conteniendo boro. Algunas de estas redes fueron capaces de operar con impulsos de la misma polaridad emitidos por dos de los ultimos dinodos, incluso con la salida de un solo electrodo. Ello puede ser util cuando conviene emplear el anodo independientemente, por ejemplo, para sincronizacion. (author) [Russian] Kak uzhe soobshchalos' ran'she, forma stsintillyatsionnogo impul'sa, kharakterizuyushchaya tip vozbuzhdayushchej chastitsy (ehlektron, proton, al'fa i t.d.), mozhet byt' prevrashchena v nezavisimyj ot amplitudy impul'sa parametr. EHto pozvolyaet vyyavit' posredstvom mnogokanal'nogo analizatora sostav vozbuzhdayushchego stsintillyator puchka so smeshannymi chastitsami. EHtot metod byl uspeshno primenen k neskol'kim stsintillyatoram kak organicheskogo, tak i neorganicheskogo tipa. Privodyatsya detali ehlektronnykh metodik, ispol'zovannykh dlya preobrazovaniya formy impul'sov. Dlya bolee prostykh sluchaev diskriminatsii tol'ko mezhdu dvumya vidami impul'sov (naprimer, diskriminatsiya nejtronov ot gamma-izluchenij) rassmatrivalas' takzhe vozmozhnost' ispol'zovaniya passivnykh skhem, predstavlyayushchikhsya perspektivnymi dlya dal'nejshikh usovershenstvovanij i uproshchenij. Bylo isprobovano neskol'ko skhem, glavnym rezul'tatom chego bylo to, chto pri nalichii fona gamma-izlucheniya udalos' rasprostranit' diskriminatsiyu protonov otdachi v zhidkikh stsintillyatorakh na malye impul'sy vsego lish' v neskol'ko desyatkov fotoehlektronov, a takzhe dobit'sya diskriminatsii oskolkov zakhvata nejtronov v soderzhashchikh bor zhidkostyakh. Nekotorye iz ehtikh skhem byli prednaznacheny dlya raboty s impul'sami odinakovoj polyarnosti, podavaemymi dvumya poslednimi ehlektrodami umnozhitelya, ili dazhe s vykhodnymi impul'sami odnogo lish' ehlektroda. EHto mozhet okazat'sya poleznym pri nezavisimom ispol'zovanii anoda, naprimer, dlya

The Role of Free-Radicals in the Radiation Vulcanizing of Elastomers; Role des radicaux libres dans la vulcanisation radiochimique des elastomeres; O roli svobodnykh radikalov v protsesse radiatsionnoj vulkanizatsii ehlastomerov; Papel de los radicales libres en la radiovulcanizacion de los elastomeros

Energy Technology Data Exchange (ETDEWEB)

Kuz' minskij, A. S.; Fedoseeva, T. E.; Chertkova, V. F.

1963-11-15

izlucheniya v poslednee vremya ispol'zuetsya dlya sozdaniya promyshlennykh protsessov vulkanizatsii rezinovykh izdelij. Issledovateli udelyayut dostatochno bol'shoe vnimanie voprosam mekhanizma obrazovaniya trekhmernoj setki pod dejstviem izlucheniya; odnako do sikh por nedostatochno izucheny nachal'nye i promezhutochnye stadii radiatsionno-khimicheskikh reaktsij, vedushchikh k zashivaniyu molekulyarnykh tsepej, kotorye svyazany s obrazovaniem i gibel'yu svobodnykh radikalov, ion-radikalov i vozbuzhdennykh molekul. Izuchenie struktury i svojstv ehtikh chastits stalo vozmozhnym tol'ko s razrabotkoj i shirokim ispol'zovaniem metoda ehlektronnogo paramagnitnogo rezonansa (EHPR), pozvolyayushchego poluchit' neposredstvennuyu informatsiyu o strukture i svojstvakh paramagnitnykh chastits. Issledovanie protsessov rekombinatsii svobodnykh radikalov v linejnykh polimerakh daet vozmozhnost' podojti neposredstvenno k mekhanizmu radiatsionnoj vulkanizatsii. V poslednee vremya poyavilas' tendentsiya ispol'zovat' ioniziruyushchee izluchenie dlya vulkanizatsii sernykh vulkanizatov, tak kak sochetanie sernykh i uglerodnykh poperechnykh svyazej daet maksimal'noe uluchshenie fiziko-mekhanicheskikh svojstv izdelij. V svyaz'i s ehtoj novoj problemoj predstavlyalo interes izuchenie kineticheskikh svojstv svobodnykh radikalov v polimerakh s razvitoj prostranstvennoj strukturoj. Podrobno isledovalis' protsessy rekombinatsii svobodnykh radikalov, poluchennykh u-oblucheniem, v svyazi so strukturnymi osobennostyami linejnykh i sshitykh polimerov, a imenno - orientatsiej i vnutrennej podvizhnost'yu molekulyarnykh tsepej. V vysokoehlasticheskikh polimerakh tipa kauchukov, kharakterizukhshchikhsya bol'shoj vnutrennej podvizhnost'yu tsepej i maloj ehnergiej mezhmolekulyarnykh svyazej, pri temperaturakh vyshe T akty rekombinatsii svobodnykh radikalov osushchestvlyayutsya s ochen' bol'shimi skorostyami. Kontsentratsiya radikalov v obraztsakh kauchukov, obluchennykh v zhidkom azote, umen'shaetsya pri

Plasma Equilibrium in a Torus with High-Frequency Fields and Plasma Heating Resulting from the Development of a Powerful Beam of ''Escaping Electrons''; Plasma Torique: Stabilisation au Moyen de Champs de Haute Frequence et Chauffage par Formation d'un Flux Intense d'Electrons 'Emballes'; Ehksperimental'noe issledovanie ravnovesiya plazmy v tore pri nalichii vysokochastotnykh polej i nagreva plazmy za schet razvitiya moshchnogo puchka ''ubegayushchikh ehlektronov''; Equilibrio del Plasma en un Toro, en Presencia de Campos de Alta Frecuencia, y Calentamiento del Plasma por el Desarrollo de un Haz Potente de 'Electrones Desbocados '

Energy Technology Data Exchange (ETDEWEB)

Demirkhanov, R. A.; Kirov, A. G.; Stotland, M. A.; Malykh, N. I.; Horasanov, G. L.; Vishnevskij, N. K.; Gutkin, T. I.; Jampol' skij, I. R. [Fiziko-Tehnicheskij Institut Gosudarstvennogo Komiteta po Ispol' zovaniju Atomnoj Ehnergii SSSR, Sukhumi, SSSR (Russian Federation)

1966-04-15

razvertka svechenija plazmy vo vremeni s pomoshh'ju jelektronno- opticheskogo preobrazovatelja; v) izmerenija povedenija (polnoj intensivnosti rentgenovskogo izluchenija vo vremeni s pomoshh'ju scintilljacionnogo schetchika; g) izmerenie toka v plazme i naprjazhenija na obhode. Rezul'taty jeksperimentov pokazyvajut, chto podzhigajushhee vysokochastotnoe pole s chastotoj f = 8,3 Mgc), sozdaet plazmu, kasajushhujusja stenok, so srednej plotnost'ju P{sub e} = 5 * 10{sup 12} * 10{sup 13} sm{sup -3} i jelektronnoj temperaturoj porjadka neskol'kih jelektronvol't. Pri nalozhenii na jetu plazmu vrashhajushhegosja kvadrupol'nogo vysokochastotnogo polja plazma otzhimaetsja ot stenok, lokalizuetsja v centre i temperatura ee uvelichivaetsja. Issledovalsja rezhim nagreva'sil'nym jelektricheskim polem v otsutstvie vrashhajushhegosja vysokochastotnogo kvadrupol'nogo polja. V jetom sluchae, kogda jelektricheskoe pole ravno E{sub z} = 100 * 200 v/sm v plazme razvivaetsja tok Jp =3 * 5 ka, kotoryj imeet sushhestvenno omicheskij harakter pri sil'nom zatuhanii. V to zhe vremja naprjazhenie na obhode takzhe ves'ma sil'no zatuhaet po sravneniju s holostym hodom, chto ukazyvaet na jeffektivnoe pogloshhenie jEhnergii kontura plazmoj. Velichina jEhnergii, pogloshhennoj plazmoj v techenie pervogo poluperioda toka, t.e. za vremja okolo 1 mksek, sostavljaet primerno 20 dzh; pri jetom okazyvaetsja, chto provodimost' plazmy anomal'no mala. V rezhime nagreva sil'nym jelektricheskim polem nabljudaetsja intensivnaja vspyshka rentgenovskogo izluchenija s jenergiej porjadka 100 kjev, a takzhe izluchenie mikrovolnovyh shumov na chastotah blizkih k plazmennoj. (author)

An Assessment of those Metabolites Considered to be of Value in the Diagnosis of Exposure to Radiation; Evaluation des Metabolites Consideres Comme Utiles dans le Diagnostic des Expositions aux Rayonnements; 041e 0426 0414 ; Evaluacion de los Metabolitos Considerados Utiles para Diagnosticar la Exposicion a las Radiaciones

Energy Technology Data Exchange (ETDEWEB)

Smith, H.; Bates, T. H. [United Kingdom Atomic Energy Authority, Chapelcross, Annan, Scotland (United Kingdom)

1965-06-15

-oblucheniju v terapevticheskih celjah. Jeti pacienty poluchili dozy do 5000 r za period ot treh do pjati nedel'. Vydelenie s mochej kreatina, kreatinina, obshhego {alpha}-amidnogo azota, {beta} aminoizom asljanoj kisloty, pirolle-2- karbonovoj kisloty, 5-oksiindoleaciticheskoj kisloty i indoksil-sul'fata soprovozhdalis' kolichestvenno v techenie vsego hoda lechenija. Nikto iz pacientov ne podvergalsja oblucheniju vsego organizma, no ochevidno, chto izmenenija v metabolicheskoj funkcii v rezul'tate povrezhdenija, vyzvannogo izlucheniem, mozhet skazat'sja na mochevom vydelenii. Obsuzhdaetsja biohimicheskaja ocenka i interpretacija jetih obrazcov vydelenija v otnoshenii toj chasti obluchennogo organizma, no na jetoj stadii issledovanija delaetsja vyvod, chto kolichestvennaja ocenka biologicheskogo povrezhdenija ne vozmozhna. Odnako takie opyty mogut byt' poleznymi v kachestve rukovodstva dlja klinicista otnositel'no jetogo vida terapii. Predvaritel'nye opyty na osnove izmenenij v nekotoryh metabolitah plazmy u krys, obluchennyh edinymi subletal'nymi dozami rentgenovskogo obluchenija, dostojny jekstrapoljacii dlja izuchenija chelovecheskogo organizma. Izmerjalis' koncentracii plazmy 5-oksitrip- taminovoj mochevoj kisloty, SGOT, SGPT, frakcii globulina proteina, fosfokinaza kreatina, aminopeptidaza lejcina, aminopeptidaza lizila, kalikreina, kallidina, cinka i marganca. Nabljudalis vse zhe znachitel'nye kolichestvennye izmenenija v urovnjah plazmy mochevoj kisloty, aminopeptidaza lejcina, aminopeptidaza lizila i marganca posle obluchenija. O b suzhdaetsja znachenie jetih dannyh. Vnimanie koncentriruetsja na prostyh i bystryh metodah. (author)

The Prompt Gamma-Ray, Prompt Electron and Prompt X-Ray Spectra Associated with Fission Fragments of Specific Mass; Spectres de Rayons Gamma Instantanes, d'Electrons Instantanes et de Rayons X Instantanes Associes a des Fragments de Fission de Masse Donnee; 041c 0413 041d 041e 0414 ; Espectros de Rayos Gamma. Electrones y Rayos X Inmediatos, Vinculados a Fragmentos de Fision de Masa Determinada

Energy Technology Data Exchange (ETDEWEB)

Bowman, H. R.; Thompson, S. G.; Watson, R. L.; Kapoor, S. S.; Rasmussen, J. O. [Lawrence Radiation Laboratory, University of California, Berkeley, CA (United States)

1965-07-15

jenergij, a jadernye zarjady byli opredeleny putem izmerenija jenergij rentgenovskogo K-izluchenija, svjazannyh s razlichnymi massami. Velichina i otmetka Dopplerovskogo smeshenija v jenergii gamma-kvanta pozvolili prichislit' linii gamma-kvantov k otdel'nym chlenam oskolochnyh par. Dopplerovskoe smeshhenie obespechivaet takzhe nezavisimoe izmerenie skorosti oskolka i, sledovatel'no, massy oskolka posle ispuskanija nejtronov. Rezul'taty izmerenij rentgenovskih luchej soglasujutsja s mneniem, chto bol'shinstvo mgnovennyh rentgenovskih luchej, izluchaemyh vo vremja spontannogo delenija kalifornija-252, javljaetsja rezul'tatom vnutrennej konversii v hode vysvechivanija sovokupnyh sostojanij nizkoj jenergii pervichnyh oskolkov delenija . Avtory polagajut, chto pomimo obsuzhdennyh vyshe konkretnyh rezul'tatov naibolee vazhnym sledstviem ih jeksperimentov javilas' demonstracija togo, chto imeetsja vozmozhnost' izuchenija svojstv otdel'nyh oskolkov delenija, ustanovlennyh harakteristikami iz izluchenij (vmesto togo, chtoby izuchat' svojstva srednego oskolka delenija s pomoshh'ju srednej massy i zarjada). Raskryvajutsja preimushhestva jetogo usovershenstvovanija v metode izuchenija oskolkov delenija. (author)

Profile counting; Comptage suivant l'axe principal du corps; Issledovanie schetchikom vdol' vsego tela; Recuento segun el eje principal del cuerpo

Energy Technology Data Exchange (ETDEWEB)

Pochin, E E [Medical Research Council, Department of Clinical Research, University College Hospital Medical School, University Street, London, W. C. 1 (United Kingdom)

1959-07-01

izmereniyakh, a issledovanie schetchikom prodolzhaetsya s tsel'yu sledit' za peremeshniem ili izmeneniem kontsentratsii v ehtikh organakh. EHtot metod byl ispol'zovan pri izuchenii kontsentratsii I{sup 131} i obmena veshchestv v rakovykh opukholyakh shchitovidnoj zhelezy, i predstoit obsudit' ego tsennost' dlya lecheniya takikh opukholej radioaktivny m iodom. On primenyalsya takzhe dlya izucheniya raspredeleniya mechenogo tiroksina i tijodotronina posle ikh vvedeniya v venu i chastits okisi ittriya{sup 90} posle vnutrilegochnoj arterial'noj infektsii, a takzhe drugikh izotopov s pomoshch'yu gamma i tormoznogo izlucheniya. EHtot metod uproshchaet, v udobnykh v klinicheskom otnoshenii usloviyakh, sostavlenie skhemy vsego tela, kotoraya, v chastnosti, pozvolyaet provesti kolichestvennoe sravnenie raspredeleniya izotopov v razlichnye promezhutki vremeni posle vvedeniya odnoj ili neskol'kikh posleduyushchikh doz radioizotopa. (author)

A Low-Background Liquid-Scintlllation Counter for the Assay of Low-Specific Activity Tritiated Water; Compteur a scintillations a liquides, a faible mouvement propre, pour le dosage d'eau tritiee en faible activite specifique; ZHidkostnyj stsintillyatsionnyi schetchik s nizkim fonom dlya analiza nasyshchennoj tritiem vody s nizkoj udel'noj aktivnost'yu; Contador de centelleador liquido de reducida actividad de fondo para el analisis de agua pritiada de baja actividad especifica

Energy Technology Data Exchange (ETDEWEB)

Boyce, I S; Cameron, J F [Wantage Research Laboratory, Wantage (United Kingdom)

1962-01-15

emana del fotocatodo del fotomultiplicador. Utilizando dos fotomultiplicadores con fotocatodos de pyrex en contacto, encerrados en un blindaje de hierro de 20 cm de espesor, hicieron experimentos para determinar la importancia relativa de las siguientes posibles causas de la actividad de fondo: a) Ionizacion y excitacion del gas residual y de las superficies del dinodo semiconductor, especialmente en las regiones en que la densidad de corriente es maxima; b) Formacion de chispas, electroluminiscencia y emision de campo; c) Realimentacion de iones positivos al fotocatodo, que provoca una emision de electrones, secundarios ; d) Funcionamiento de la propia ventana fotocatodica en caracter de ''fosforo'' para la radiacion cosmica, las particulas del {sup 40}K o las radiaciones de los productos de filiacion del uranio. Los autores comprobaron que, en particular, el factor c) interviene en una proporcion mucho menor que lo que se habia supuesto. Estudiaron metodos para reducir a un minimo estos efectos, incluyendo el uso de fotocatodos de cuarzo y fotomultiplicadores especiales. Con el dispositivo disenado por los autores, la minima actividad especifica detectable, con un tiempo de recuento de 30 min, asciende a 6 x 10{sup 7}{mu}c/ml. (author) [Russian] Pri schege zhidkostnykh stsintillyatsij nasytsennoj tritiem vody schetchiki s odnim fotoumnozhitelem i sistemy sovpadenij dayut pokazaniya sravnitel'noj chuvstvitel'nosti. Dlya issledovaniya scheta izlucheniya maloj intensivnosti byla primenena sistema sovpadenij dlya togo, chtoby izbezhat' neopredelennosti v fone, vyzyvaemom izmeneniemi odnogo fotona v rezul'tate fosforestsentsii i khimicheskoj lyuminestsentsii v rastvore. Bylo obnaruzheno, chto vozniknovenie fona v ehtoj sisteme ob{sup y}asnyaetsya glavnym obrazom dejstviem sveta, iskhodyashchego iz fotokatoda fotoumnozhitelya. Byli provedeny ksperimenty s primeneniem dvukh fotoumnozhitelej s fotokatodami Pireks v kontakte s zheleznym ehkranom tolshchinoj v 8 dyujmov dlv

Catalytic Activity and Nuclear Radiation; L'activite catalytique et les rayonnements nucleaires; Kataliticheskaya aktivnost' i yadernoe izluchenie; La actividad catalitica y las radiaciones nucleares

Energy Technology Data Exchange (ETDEWEB)

Turkevich, J.; Ikawa, T.; Nozaki, F.; Stamires, D. [Princeton University, N.J (United States)

1963-11-15

que se crean sitios desprovistos de cationes en el tamiz. Se ha preparado una serie graduada de estos catalizadores que poseen numeros regularmente crecientes de tales sitios desde cero hasta un ciento por ciento con respecto al contenido original de sodio. Los autores determinaron la actividad catalitica de esas dos series de catalizadores antes y despues de someterlos a irradiacion gamma, estudiando la cinetica de la descomposicion del eumeno en benceno y propileno, la isomerizacion del butano-1 en butano-2 por desplazamiento del doble enlace y la reaccion de intercambio hydrogenodeuterio. Se determino el numero de sitios activos recurriendo al envenenamiento progresivo por medio de quinolei'na, lo que permite establecer la actividad por cada sitio. Tambien se estudiaron los materiales midiendo la resonancia del espin electronico de agentes de transferencia de electrones adsorbidos tales como la trifenilamina, el perileno y el difeniletileno simetrico. Se comprobo que la capacidad de transferencia de electrones era paralela a la actividad catalitica. Para determinar la naturaleza de los sitios cataliticos, se utilizo la resonancia protonica del agua adsorbida. (author) [Russian] Predstavlena' novaya rabota po issledovaniyu dejstviya gamma-izlucheniya na kataliticheskuyu aktivnost' alyumosilikagelya i dekationirovannykh molekulyarnykh sit .gida Linde Y. Metodom sooavzhdeniya prigotovlen rnd obraztsov katalizatorov alyumosilikagelya, prichem atomnoe otnoshenie alyuminiya k kremniyu v kazhdom iz okisnykh katalizatorov bylo raznym, i takim obrazom poluchilos' desyat' razlichnykh obraztsov razlichnykh sostavov. Drugaya seriya obraztsov katalizatorov poluchena pri nepolnom zameshchenii natriya v molekulyarnom site tipa Linde Y (Na{sub 56}(AlO{sub 2}){sub 56}(SiO{sub 2} ){sub 126} na ion ammoniya) i pri posleduyushchem razlozhenii ego dlya udaleniya kak ammiaka, tak i vody. Pri ehtom v site obrazovyvalis' vakansii kationov. Prigotovlena tselaya seriya takikh katalizatorov

Technical Developments in the USAEC Process Radiation Development Program; Etudes technologiques dans le cadre du programme de mise au point d'applications industrielles des rayonnements de la CEA-EU; Issledovaniya v oblasti promyshlennogo primeneniya izluchenij, vkhodyashchie v programmu komissii po atomnoj ehnergii USAEC; Progresos tecnicos en el programa de la USAEC para el fomento de la irradiacion industrial

Energy Technology Data Exchange (ETDEWEB)

Machurek, J. E.; Stein, M. H. [Division of Isotopes Development, USAEC, Washington, DC (United States)

1963-11-15

ispol'zovanie ioniziruyushchikh izluchenij v promyshlennosti. Provedeno chetyrnadtsat' takikh issledovanij, rezul'taty nekotorykh iz nikh izlozheny v obshchikh chertakh v dannoj rabote, ostal'nye izlagayutsya bolee podrobno - v drugikh stat'yakh trudov. Temy issledovanij vklyuchayut: 1. Prigotovlenie kombinatsij derevo-plastik, ispol'zuya gamma-izluchenie dlya indutsirovaniya polimerizatsii. 2. Ispol'zovanie beta-izlucheniya produktov deleniya dlya gidrogenizatsii uglya, i ego produktov s tsel'yu polucheniya zhidkogo uglevodorodnogo topliva. 3. Poluchenie poluprovodnikovykh priborov s formirovaniem zadannogo prostranstvennogo raspredeleniya primesej v zavisimosti ot legirovaniya putem nejtronnykh prevrashchenij. 4. Vyzvannaya izlucheniem polimerizatsiya ehtilena i sopolimerov. 5. Osnovnye issledovaniya mekhanizmov i kinetiki reaktsij, vyzvannykh izlucheniem. 6. Radiatsionno-khimicheskie protsessy pri ftorirovanii razlichnykh aromaticheskikh soedinenij. 7. Ispol'zovanie polifunktsional'nykh monomerov dlya intensifikatsii radiatsionnogo sshivaniya poliehtilena, polipropilena, poliizobutilena i atsetattsellyulozy. 8. Vliyanie nabukhaniya, deformatsii i temperatury na fizicheskie i khimicheskie svojstva polimerov, poluchennykh s pomoshch'yu radiatsii. 9. Vliyanie strukturnykh faktorov na radiatsionnye izmeneniya v polimerakh, privodyashchie k graftsopolimerizatsii. 10. Ispol'zovanie yadernykh izluchenij dlya modifikatstsii tekstil'nykh materialov. 11. Reaktsii, vyzvannye izlucheniem kriptona-85. 12. Podgotovka ''Spravochnika po radiatsii''. 13. Ispol'zovanie metalloorganicheskoj svyazi dlya gamma-dozimetrii pri bol'shikh moshchnostyakh dozy. 14. Razrabotka dozimetra s solnechnym ehlementom. (author)

High-voltage-powered transistorized preamplifier; Pre-amplificateur transistorise avec alimentation haute tension; Vysokovol'tnyj ehnergeticheskij predvaritel'nyj usilitel' na tranzistorakh; Preamplificador transistorizado alimentado con alta tension

Energy Technology Data Exchange (ETDEWEB)

Wilson, Jr, W E; Wakefield, A W [University of Washington, Seattle, WA (United States)

1962-04-15

transistorizado unico en su genero utilizado con gran exito en la Universidad de Washington. El circuito en cuestion tiene la particularidad de que el transistor esta alimentado con la alta tension suministrada al detector de radiaciones. Con los dos transistores de union PNP empleados en el preamplificador se obtiene una ganancia de tension unidad en un intervalo dinamico de 1 mV a 5 V. La tension de trabajo del transistor con carga en el emisor se estabiliza mediante un pequeno diodo Zener. El consumo de corriente de detector de centelleo distante que utiliza el circuito esta comprendido entre 0,35 y 0.65 mA cuando la alta tension suministrada varia entre 800 y 1500 V. El dispositivo alimenta 500 pies de cable coaxial de 52 {Omega} con una perdida de un 25% en la amplitud del impulso. Se ha utilizado con excelentes resultados, con detectores de centelleo alejados y detectores neutronicos de BF{sub 3}. (author) [Russian] Odnoj iz problem, chasto vstrechayushchikhsya v oblasti yadernoj ehlektroniki, yavlyaetsya problema svyazi signala, idushchego s impul'nogo detektora izluchenij vysokogo soprotivleniya, s liniej peredachi nizkogo soprotivleniya. Inymi slovami detektory izluchenij i svyazannoe s nimi schetnoe oborudovanie chasto razdelyayutsya znachitel'nym rasstoyaniem, poehtomu sleduet predusmatrivat' nadezhnye sredstva peredachi signala iz detektora v schetnuyu sistemu. Prakticheski dlya linii peredachi ispol'zuetsya koaksial'nyj kabel' s nizkim soprotivleniem, a dlya polucheniya trebuemoj soglasovannosti impedansov ispol'zuetsya skhema s katodnym vykhodom ili skhema s ehmitternym vykhodom. V dannom doklade daetsya opisanie unikal'noj skhemy s ehmitternym vykhodom, kotoraya uspeshno primenyalas' v Vashingtonskom universitete. Skhema ehmitternogo vykhoda yavlyaetsya unikal'noj v tom smysle, chto istochnikom ehnergii tranzistornoj skhemy sluzhit vysokoe napryazhenie, podavaemoe detektoru izlucheniya. Primenenie v predvaritel'nom usilitele dvukh splavlennykh tranzistorov s

Perspectives for the Use of Ionizing Radiation in the Decontamination (Salmonella Radicidation) of Some Frozen Proteinaceous Foods and Dry Mixed Feed Ingredients; Perspectives de l'Emploi des Rayonnements pour la Decontamination (Radicidation de Salmonella) de Certains Aliments Proteiques Congeles et des Constituants de Melanges Alimentaires Secs pour Animaux; Perspektivy ispol'zovaniya ioniziruyushchego izlucheniya dlya unichtozheniya bakterij (Gruppy Salmonella) nekotorykh zamorozhennykh belkovykh osnovnykh pishchevykh produktov i sukhikh komponentov smeshannogo'fura; Radiodescontaminacion (Radicidacion de la Salmonella) de Algunos Alimentos Proteicos Basicos Congelados y de Componentes de Alimentos Secos para Animales

Energy Technology Data Exchange (ETDEWEB)

Mossel, D. A.A. [Central Institute for Nutrition and Food Research T.N.O., Zeist (Netherlands)

1966-11-15

Radiation decontamination, particularly of proteinaceous staple foods of low water activity, seemed to be promising, as one of the first applications of ionizing energy in food ancieed processing because of (a) restricted radiochemical damage to the commodities concerned; (b) absence of microbial proliferation subsequent to irradiation; and (c) some, often unique, technological advantages, such as applicability to materials already packaged, e.g. mixed feed ingredients, and effective decontamination without simultaneously- losing freshness, as in the case of red meats and poultry. As a first step, laboratory-scale dose range-finding experiments in this area were carried out earlier with, at the same time, sub-acute testing for wholesomeness. The results of these experiments were very promising. Pilot-plant-scale tests were next carried out, while concurrently research on wholesomeness was extended to a full two years/three generations assay with rats. In these tests it was confirmed that a dose of the order of 0.7 {+-} 0.1 Mrad suffices for the elimination of Salmonellae from frozen and dried proteinaceous products, such as chickens, fish meal and mixed feed. If, for reasons of analytical facility, a negative Enterobacteriaceae test for representative numbers of samples of the order of 10 g of radicidized material were preferred, the radiation dose would have to be slightly raised; the strict maximum would then amount to 1.0 Mrad, e.g. when mixed feeds, initially containing higher numbers of relatively radiation-resistant, pigmented Enterobacter strains were to be treated. No consistent, radiation-dependent, untoward effects on the experimental animals used, i.e. rats and, to a lesser extent, piglets, was detected at any of the irradiation levels tested. It is, therefore, concluded that the third evaluation step can now be undertaken, that is: tentative commercial-scale decontamination experiments in the region of production. Latin American countries like Argentina and Peru might be the most promising areas for the first tests of this sort, as they are amongst the greatest exporters of some of the commodities that are most frequently found contaminated with Salmonellae (frozen boneless horse meat, and fish and cottonseed meals), while having generally well- equipped laboratories and reasonably well-trained graduate staff available. A 50 000-Ci source of {sup 60}Co, or an X-ray machine of a similar output, may be successfully used in such test runs. Microbiological evaluation techniques for routinely controlling the efficacy of such irradiation treatments have already been worked out and tested under pilot plant conditions. Finally, wherever possible, the merits of these radicidation treatments should be experimentally compared with those of competitive, conventional processing methods, such as pelleting in the decontamination of feed ingredients; this approach would make it possible for the industries concerned to take their decisions at the completion of the first commercial-scale tests. (author) [French] La decontamination par les rayonnements, notamment celle des denrees proteiques de base a faible activite chimique de la teneur en eau est apparue comme une des premieres applications prometteuses de l'energie ionisante au traitement des denrees alimentaires destinees a la consommation humaine ou animale; les raisons en sont les suivantes: a) alteration radio chimique limitee des denrees en question; b) absence de toute proliferation microbienne apres irradiation; c) avantages techniques souvent exceptionnels, telle la possibilite d'application a des produits deja empaquetes, par exemple aux constituants de melanges alimentaires pour animaux, et la decontamination efficace sans alteration simultanee de la fraicheur, notamment dans le cas des viandes rouges et de la volaille. Comme premiere etape, on a procede anterieurement a des experiences en laboratoire en vue de determiner les diverses doses necessaires et de verifier simultanement la comestibilite apres irradiation a des doses sous-critiques. Les donnees obtenues etant fort prometteuses, on a procede ensuite a des essais dans des installations pilotes en entreprenant en meme temps une etude de la comestibilite sur des rats pendant deux annees entieres (trois generations). Ces essais ont confirme qu'une dose de l'ordre de 0,7 i 0,1 Mrad suffisait amplement pour detruire les Salmonellae dans les produits proteiques congeles ou deshydrates tels que poulets, farines de poisson ou melanges alimentaires pour animaux. Lorsque, pour des raisons de facilite d'analyse, on etait amene a preferer un test entero-bacterien negatif pour un nombre representatif d'echantillons de l'ordre de 10 g de matieres traitees par radicidation, il fallait augmenter l'egerement la dose de rayonnement; la dose maximale strictement necessaire s'elevait alors a 1,0 Mrad, par exemple lorsqu'il s'agissait de traiter des melanges alimentaires pour animaux, contenant initialement un grand nombre de souches de bacteries intestinales pigmentees a radioresistance relativement elevee. Quel que fut le niveau d'irradiation, aucun des essais n'a permis de detecter un effet radioinduit defavorable se reproduisant regulierement chez les rats et encore moins chez les jeunes potes utilises pour les experiences. On peut donc conclure qu'il est desormais possible de passer a la troisieme etape d'evaluation, c'est-a-dire aux essais de decontamination a l'echelle industrielle dans les regions productrices. Les pays d'Amerique latine, tels que l'Argentine et le Perou, peuvent presenter un grand interet pour les premiers essais de ce genre du fait qu'ils figurent parmi les plus grands exportateurs de plusieurs des produits frequemment contamines de Salmonellae (viande de cheval desossee congelee et produits a base de poisson et de grains de coton), et qu'ils disposent generalement de laboratoires bien equipes et d'un personnel diplome suffisamment competent. Au cours de ces essais on pourrait utiliser avec succes des sources de 50 000 Ci au cobalt-60 ou un appareil a rayons X d'une puissance analogue. On a d'ores et deja elabore et verifie dans des installations-pilotes des methodes d'evaluation microbiologiques permettant de controler regulierement l'efficacite de ces traitements par irradiation. Enfin, toutes les fois ou cela se revele possible, les avantages de ces traitements par radicidation devraient faire l'objet de comparaisons experimentales avec les methodes de traitement classiques competitives telles que rechauffement par agglomeration dans le'cas de la decontamination des constituants de produits alimentaires pour animaux; cette maniere de proceder permettra en outre aux industries interessees de prendre leurs decisions apres achevement des premiers essais a l'echelle commerciale. (author) [Spanish] La radiodescontaminacion de los alimentos proteicos basicos de escaso contenido de agua residual parece ser una de las primeras aplicaciones interesantes de las radiaciones al tratamiento de los alimentos del hombre y de los animales debido a las pocas alteraciones radioquimicas producidas en los alimentos tratados, a la ausencia de una proliferacion microbiana subsiguiente a la irradiacion, y a ciertasiventajas tecnologicas inherentes a ese procedimiento: la posibilidad de tratar productos ya empaquetados (mezclas de ingredientes de alimentos para animales) y la eficacia de la decontaminacion sin que los alimentos dejen de ser frescos, como en el caso de la carne roja y de la carne blanca. Para empezar se efectuaron experimentos de laboratorio con objeto de determinar la escala de las dosis y se llevaron a cabo algunos ensayos sobre comestibilidad. Como los resultados experimentales fueron muy prometedores, se hicieron ensayos en planta piloto y los estudios sobre comestibilidad se extendieron a dos anos utilizando tres generaciones de ratas. Estos ensayos confirmaron que una dosis del orden de 0,7 {+-} 0,1 Mrad basta para eliminar las Salmonellae de los productos proteicos congelados y deshidratados: pollos, harina de pescado, mezclas de alimentos para animales. Si por razones de comodidad analitica, se prefiriese un ensayo negativo de Enterobacteriaciae para un numero representativo de muestras del orden de 10 g de sustancias radicidadas, habria que aumentar algo la dosis, que seria entonces de 1,0 Mrad como maximo, para las mezclas de alimentos destinados a los animales, que en principio contienen un numero mas elevado de cepas pigmentadas de Enterobacteriaciae relativamente radiorresistentes. Con las dosis ensayadas no se ha observado ningun efecto perjudicial de las radiaciones en los animales de laboratorio utilizados (ratas y, en menor medida, cerdos jovenes). Puede iniciarse ya la tercera etapa, que consistira en experimentos de descontaminacion en escala comercial efectuados en las zonas de produccion. Algunos paises latinoamericanos tales como la Argentina y el Peru podrian ser las regiones mas adecuadas para efectuar los primeros ensayos de esta indole, pues figuran entre los mayores exportadores de algunos de los productos que con frecuencia estan contaminados por las Salmonellae (carne de caballo congelada y desosada, harinas de pescado y de semilla de algodon), y al mismo tiempo disponen de laboratorios bien equipados y de personal competente. Para estos ensayos puede utilizarse con exito una fuente de {sup 60}Co de 50 000 Ci o un aparato de rayos X de capacidad analoga. Se han elaborado ya, o se estan ensayando en planta piloto, algunas techicas de evaluacion microbiologica para controlar la eficacia de este tipo de irradiacion. Por ultimo, siempre que sea posible, habra que comparar experimentalmente las ventajas de esta radicidacion con otros metodos tradicionales de tratamiento, por ejemplo, la descontaminacion por el calor al fabricar aglomerados con ingredientes de los alimentos de animales. Esto permitira que las industrias interesadas tomen sus decisiones al terminar los primeros ensayos en escala comercial. (author) [Russian] Radiacionnaja dezaktivacija, osobenno belkovyh osnovnyh pishhevyh produktov nizkoj vodnoj aktivnosti, kak predstavljalos', dolzhna byla ispol'zovat'sja v kachestve odnogo iz pervyh primenenij ionizirujushhej jenergii v obrabotke pishhevyh produktov i furazha v silu a) ogranichennogo radiohimicheskogo povrezhdenija sootvetstvujushhih predmetov potreblenija; b) otsutstvija mikrobnoj proliferacii posle obluchenija; v) nekotoryh, chasto edinstvennyh v svoem rode, tehnologicheskih preimushhestv, kak, naprimer, primenimosti k uzhe upakovannym materialam, naprimer, k komponentam smeshannogo furazha, i jeffektivnoj dezaktivacii bez odnovremennoj poteri svezhesti, chto imeet mesto v sluchae s obychnym mjasom i mjasom domashnej pticy. V kachestve pervogo shaga byli provedeny laboratornye opyty po opredeleniju diapazona doz v jetoj oblasti odnovremenno s pochti maksimal'nym ispytaniem na sohranenie vkusovyh i pitatel'nyh kachestv. Poskol'ku rezul'taty jetih opytov javljalis' ves'ma obnadezhivajushhimi, byli provedeny opytnye ispytanija, hotja odnovremenno nauchnye issledovanija na sohranenie vkusovyh i pitatel'nyh kachestv byli prodleny na polnye dva goda, i prove- . deny opyty na treh pokolenijah krys. V hode jetih opytov bylo podtverzhdeno, chto doza porjadka 0,7{+-}0,1 megarad ves'ma dostatochna dlja udalenija salmonelly iz zamorozhennyh i zasushennyh belkovyh produktov, kak, naprimer, kurjatiny, rybnoj muki i smeshannogo furazha. Esli po prichinam analiticheskogo haraktera nuzhno bylo otdat' predpochtenie otricatel'nomu jenterobakterial'nomu ispytaniju dlja znachitel'nogo chisla obrazcov porjadka 10 g materiala, podvergnutogo dejstviju ionizirujushhego izluchenija, doza izluchenija dolzhna byla byt' neskol'ko uvelichena; strogaja maksimal'naja doza dolzhna sostavljat' v takom sluchae 1,0 megarad, naprimer, esli nuzhno obrabotat' smeshannyj furazh, pervonachal'no soderzhavshij bol'shoe chislo otnositel'no ustojchivyh k izlucheniju, pigmentirovannyh jenterobakterial'nyh vidov. Ni na odnom iz ispytannyh urovnej obluchenija ne bylo zafiksirovano postojannoe, radiacionno zavisimoe, neblagoprijatnoe'vozdejstvie na'po'dopytnyhzhivotnyh, naprimer,krysah i v men'shej stepeni - na porosjatah. Pojetomu delaetsja vyvod, chto teper' mozhno osushhestvit' tret'ju stupen' ocenki, kak-to: (probnye opyty po dezaktivacii na kommercheskoj osnove v rajone proizvodstva. Vozmozhno, chto latinoamerikanskie strany, kak, naprimer, Argentina i Peru, javljajutsja naibolee podhodjashhimi rajonami dlja provedenija pervyh ispytanij takogo roda, poskol'ku oni vhodjat v chislo samyh krupnyh jeksporterov nekotoryh predmetov potreblenija, kotorye chasto byvajut zarazheny salmonelloj (zamorozhennoe konskoe mjaso bez kostej, a takzhe rybnaja muka i muka iz semjan hlopka), i raspolagajut, kak pravilo, horosho oborudovannymi laboratorijami i otnositel'no horosho podgotovlennymi kadrami. Istochnik kobal't-60 v 50 000 kjuri ili rentgenovskaja ustanovka analogichnoj moshhnosti mogut uspeshno primenjat'sja pri provedenii takih ispytanij. Metody mikrobiologicheskoj ocenki dlja obychnogo kontrolja za dejstvennost'ju takoj obrabotki posredstvom obluchenija uzhe razrabotany i ispytany v opytnyh uslovijah. Nakonec, tam, gde jeto vozmozhno, v jeksperimental'nom porjadke sleduet sravnit' preimushhestva takoj obrabotki s preimushhestvami konkurentosposobnyh, obychnyh metodov obrabotki, kak, naprimer, granulirovaniem v sluchae dezaktivacii furazha; takoj podhod dast vozmozhnost' sootvetstvujushhim otrasljam promyshlennosti sdelat' svoi vyvody uzhe pri zavershenii pervyh ispytanij na kommercheskoj osnove. (author)

Evaluation of Dose: Comparative Effect of Fast Neutrons and other Types of Radiation on the Survival of E. Coli and S. Cerevisiae; Evaluation de la Dose Delivree et Actions Comparees des Neutrons Rapides et d'Autres Radiations sur la Survie de E. Coli et S. Cerevisiae; Otsenka dozy i sravnitel'noe vliyanie bystrykh nejtronov i drugikh vidov izlucheniya na vyzhivaemost' E. Coli i S. Cerevisiae; Evaluacion de la Dosis Suministrada y Comparacion de la Accion de los Neutrones Rapidos sobre la Supervivencia del E. Coli y del S. Cerevisiae con la de Otras Radiaciones

Energy Technology Data Exchange (ETDEWEB)

Arnaud, Y.; Bocquet, C. [Centre d' Etudes Nucleaires de Saclay (France)

1964-05-15

The EL-3 reactor is equipped with auranium converter by means of which fast neutrons can be obtained. A bank of fission chambers measures the flux and spectral distribution of the fast neutrons. These miniature detectors are placed at various points in the target zone and make possible the experimental evaluation of the absorbed tissue-dose. This apparatus and dosimetric technique can be used to compare the effect of fast neutrons and other types of ionizing radiation (e.g. X-rays) on unicellular organisms. The authors study the percentage of survivals and the frequency of a mutation in Saccharomyces cerevisiae. The survival curve for Escherichia coli is also determined for X-rays and neutrons. It is found that the RBE's of these various types of radiation depend not only on the species and the biological criterion adopted, but also on the irradiation dose-level at which the comparison is made. These experiments show the RBE to be also a function of dose. The effects of fast neutrons and X-rays are often brought about by differing radiobiological processes. It is arbitrary to establish linear relationships between the doses for these various types of radiation. (author) [French] Nous disposons aupres du reacteur EL3 d'un convertisseur a uranium permettant d'obtenir des neutrons rapides. Une batterie de chambres a fission mesure le flux et la repartition spectrale des neutrons rapides. Ces detecteurs miniatures sont places en divers points du volume a irradier et permettent d'evaluer experimentalement la dose absorbee dans les tissus. Ce dispositif et cette dosimetrie nous servent a comparer l'action des neutrons rapides et d'autres radiations ionisantes (X, {gamma}) sur des organismes monocellulaires. Nous etudions ici le pourcentage de survie et la frequence d'une mutation morphologique chez Saccharomyces cerevisiae. La courbe de survie d'Escherichia coli est aussi etablie pour les rayons X et les neutrons. On observe que les effets biologiques relatifs de ces diverses radiations dependent de l'organisme vivant etudie, du critere biologique choisi, mais aussi de la dose d'irradiation avec laquelle on fait la comparaison. L'efficacite biologique relative apparait dans ces experiences comme etant egalement une fonction de la dose. L'action des neutrons rapides et des rayons X releve souvent de processus radiobiologique differents. Il est arbitraire de relier entre elles les doses de ces diverses radiations par des relations lineaires. (author) [Spanish] Junto al reactor EL3 se encuentra un convertidor de uranio que permite obtener neutrones rapidos. Con una bateria de camaras de fision se mide el flujo y la distribucion espectral de los neutrones rapidos. Estos micro- detectores estan colocados en diversos puntos del volumen que se ha de irradiar y permiten evaluar experimentalmente la dosis absorbida en los tejidos. Gracias a este dispositivo y a este sistema de dosimetria, los autores han podido comparar la accion de los neutrones rapidos con las de otras radiaciones ionizantes (rayos X, rayos y) sobre organismos unicelulares. En este trabajo, estudian el porcentaje de supervivencia y la frecuencia de una mutacion morfologica en el Saccharomyces cerevisiae. Tambien han trazado la curva de supervivencia del Escherichia coli, expuesto a rayos X y a neutrones. La observacion de los resultados indica que los efectos biologicos relativos de estas diversas radiaciones dependen del organismo vivo estudiado, del criterio biologico elegido y, ademas, de la dosis de irradiacion con que se realiza la comparacion. Tambien se deduce de estos experimentos que la eficacia biologica relativa es funcion de la dosis. A menudo, la accion de los neutrones rapidos y de los rayos X depende de diferentes procesos radiobiologicos. Seria arbitrario establecer relaciones lineales entre las dosis de dichas radiaciones. (author) [Russian] Na reaktore EL-3 imeetsja uranovyj preobrazovatel, pozvoljajushhij poluchat' bystrye nejtrony. Batareja kamer delenija proizvodit izmerenie potoka i spektral'nogo raspredelenija bystryh nejtronov. Jeti miniatjurnye detektory razmeshhajutsja v razlichnyh tochkah obluchaemogo obrazca i pozvoljajut jeksperimental'no ocenivat' pogloshhaemuju tkanjami dozu. Takaja ustanovka i dozimetrija dali vozmozhnost' sravnit' vlijanie bystryh nejtronov i drugih vidov ionizirujushhego izluchenija (rentgenovy luchi) na odnokletochnye organizmy. Izuchalsja procent vyzhivaemosti i chastota morfologicheskih mutacij u Saccharo- myces cerevisiae. Ustanovlena takzhe krivaja vyzhivaemosti Escherichia coli v otnoshenii rentgenovyh luchej i nejtronov. Otmechaetsja, chto OBJe jetih razlichnyh vidov izluchenija zavisit ot issleduemogo zhivogo organizma, ot izbrannogo biologicheskogo kriterija, a takzhe ot dozy obluchenija, pri kotoroj proizvoditsja sravnenie. V jetih uslovijah OBJe javljaetsja funkciej dozy. Dejstvie bystryh nejtronov i rentgenovyh luchej chasto zavisit ot razlichnyh radiobiologicheskih processov. Bylo by proizvol'no svjazyvat' mezhdu soboj dozy jetih razlichnyh izluchenij linejnymi otnoshenijami. (author)

RBE of some Sodium, Water and Bioelectric Parameters of Gastro-Intestinal Absorption; L'EBR pour le Transport du Sodium et de l'Eau et pour Certains Parametre Bioelectriques dans l'Absorption Gastro-Intestinale; Obeh v otnoshenii nekotorykh natrievykh, vodnykh i bioehlektricheskikh parametrov vsasyvaniya v zheludochno-kishechnom trakte; La EBR Para el Transporte del Sodio y del Agua y Para Ciertos Parametros Bioelectricos en la Absorcion Gastrointestinal

Energy Technology Data Exchange (ETDEWEB)

Vaughan, B. E.; Davis, A. K.; Cummins, J. T.; Alpen, E. L. [US Naval Radiological Defense Laboratory, San Francisco, CA (United States)

1964-05-15

permeabilidad decrece al aumentar las dosis de irradiacion. (author) [Russian] Ranee soobshhalos' o biojelektricheskih izmerenijah i izmerenii potoka v odnom napravlenii. Krys i sobak pod- vergali rentgenovskomu oblucheniju pri pikovym naprjazhenii 250 kv (krysy) ili 1000 kv (sobaki) i oblucheniju bystrymi nejtronami. Obluchenie bylo obshhim, dvustoronnim, v kazhdom sluchae proizvodilas' glubinnaja dozimetrija. U hrys cherez 7 dnej posle obluchenija biojelektricheskaja aktivnost' zheludka znachitel'no snizhalas' po sravneniju s normoj, no v nizhnih otdelah zheludochno-kishechnogo trakta takogo snizhenija ne bylo. Dlja pozdnego snizhenija biojelektricheskoj aktivnosti zheludka ustanovlena velichina OBJe porjadka 2-3, jetot jeffekt otchetlivo zameten pri doze nejtronov v 160 rad (1-e stolknovenie). U sobak cherez tri dnja posle obluchenija skorost' odnostoronnego perehoda natrija i vody iz plazmy v prosvet kishechnika snizhalas'. Jeto nabljudaetsja posle rentgenovskogo obluchenija pri 1200 rentgen (doza v vozduhe) i posle nejtronnogo obluchenija pri 300 rad ili 600 rad (1-e stolknovenie). Odnako pri doze rentgenovyh luchej 600 rad (v vozduhe) jeti skorosti perehoda ne izmenjajutsja i imejut drugoe napravlenie. Velichina OBJe dlja pozdnego snizhenija perehoda iz plazmy v prosvet kishechnika budet ravnjat'sja 2 - 6. Izuchenie jelektrogennogo mehanizma na zheludke krysy ukazyvaet na specifichnost' iona natrija v otlichie ot dannyh, poluchennyh na zheludke ljagushki. Velichiny potencialov, poluchennye in vitro, sootvetstvujut velichinam, poluchennym in vivo, i menjajutsja lish' pod vlijaniem metabolicheskogo otravlenija ili zameshhanija natrija. V protivopolozhnost' biojelektricheskim parametram opredelenija potoka javljajutsja bolee specifichnymi; odnako znachitel'naja biologicheskaja variabil'nost' ogranichivaet ih ispol'zovanie. Odnostoronnie toki iz plazmy v prosvet kishechnika obnaruzhivajut znachitel'nye izmenenija pod vlijaniem radiacii, chto ukazyvaet na snizhenie

Effects of Monoenergetic Neutron Radiation on Human Cells in Tissue Culture; Effets des Neutrons Monoenergetiques sur des Cellules de Tissus Humains en Culture; Dejstvie oblucheniya monoehnergeticheskimi nejtronami na kletki kul'tury tkanej cheloveka; Efectos de la Radiacion Neutronica Monoenergetica sobre las Celulas Humanas en Cultivos de Tejidos

Energy Technology Data Exchange (ETDEWEB)

Broerse, J. J.; Barendsen, G. W. [Radiobiological Institute of the Organization for Health Research TNO, Rijswijk (Z.H.) (Netherlands)

1964-03-15

sharikov, pomeshhennyh sootvetstvenno mezhdu chashkami i trubkami. R a sche t dozy nejtronnogo potoka predstavljal rjad problem, kotorye obsuzhdajutsja. Poskol'ku ne sushhestvuet ravnomernogo obluchenija kletok, izuchajutsja rezul'tirujushhie netochnosti pri opredelenijah dozy. Privodjatsja krivye zavisimosti vyzhivanija ot dozy dlja oboih tipov nejtronov. Dlja nejtronov s jenergiej 3 Mjev otnositel'naja biologicheskaja jeffektivnost' sostavljala ot 6,5 pri malyh dozah do primerno 3,1 pri vysokih d o zah , v to vremja kak dlja nejtronov s jenergiej 15 Mjev velichiny OBJe ko lebalas' ot 1,9 do 1,6. Putem sravnenija jetih velichin OBJe s s o otnosheniem O B Je-LP Je , poluchennym v predydushhih jeksperimentah s dejtronami i al'f a - chasticami, mozhno opredelit' jeffektivnoe LPJe dlja nejtronov, ispol'zovannyh v jeksperimente. Dlja reshenija nekotoryh problem, svjazannyh so smert'ju jeksperimental'nyh zhivotnyh posle rentgenovskogo ili nejtronnogo obluchenija, byl razrabotan metod, s pomoshh'ju kotorogo kletki, soderzhashhiesja v nebol'shih trubkah, ispol'zujutsja dlja izmerenija jeffektivnoj dozy (t.e. dozy, dlja kotoroj vneseny popravki na OBJe) v uchastkah fantomov ili t el zhivotnyh, predstavljajushhih interes. (author)

Radioautography in the Study of Radioisotopically-Tagged Substances in Insect Control; L'autoradiographie dans l'etude de substances marquees au moy en de radioisotopes utilisees dans la lutte contre les insectes; Primenenie radioavtografii pri izuchenii substantsij, mechennykh radioizotopami, v bor'be s nasekomymi; La autorradiografia en el estudio de las sustancias marcadas con radioisotopos utilizadas en la lucha contra los insectos

Energy Technology Data Exchange (ETDEWEB)

Joftes, D. L. [New England Deaconess Hospital, Boston, MA (United States)

1963-09-15

histologicos corrientes. Un ligero desplazamiento ascendente del foco pone de relieve los detalles de la autorradiografia que, de este modo, se puede estudiar en relacion con el tejido. En la memoria se describen en detalle las tecnicas recomendadas y el sencillo equipo necesario, que suele encontrarse en todos los laboratorios. (author) [Russian] Pri otnositel'no nebol'shikh zatratakh truda bolee novye,uproshchenie metody radioavtografii obespechivayut bol'shuyu chuvstvitel'nost' i tochnost' na mikroskopicheskom urovne vo mnogikh fazakh issledovanij odnokratno i dvukhkratno mechennykh radioizotopami insektitsidov, naprimer pri issledovanii pogloshcheniya, peremeshcheniya, metabolizma i opredelenii ostatkov insektitsidov v rasteniyakh, u nasekomykh i tavotnykh. Fiziologiya i biokhimiya obluchennykh nasekomykh yavlyayutsya drugimi oblastyami primeneniya radioavtografii. Vozdejstvie oblucheniya, osobenno na generativnye organy, izuchaetsya s pomoshch'yu mechennogo tritiem timidina. V to vremya kak metody scheta dayut mnogo informatsii o nalichii i kolichestve radioizotopov, s pomoshch'yu radioavtografii mozhno poluchit' dannye o fakticheskikh mestakh ikh otlozheniya v tkanyakh ili dazhe v chastyakh kletok. Poluchenie takoj razreshayushchej sposobnosti vozmozhno na obychnykh postoyannykh gistologicheskikh preparatakh, v to vremya kak pri primenenii metodov scheta dlya polucheniya tochnogo rezul'tata trebuetsya razrushenie obraztsa. Standartnaya radioavtografiya osobenno udobna dlya proslezhivaniya malykh kolichestv izotopov, sostavlyayushchikh doli mikrokyuri, ochen' slabykh izluchatelej, takikh, kak radioaktivnyj uglerod (C{sup 14}) i tritij (H{sup 3}), togda kak dlya rabot s ochen' slabymi izluchatelyami s primeneniem metodov scheta trebuyutsya ochen' dorogie i slozhnye pribory. Metod ne imeet ogranichenij v otnoshenii izotopov, primenyaemykh dlya mecheniya, tak kak dazhe izlucheniya tritiya i C''1''4 budut fiksirovat'sya na yadernoj fotoehmul'sii. Dejstvitel'no, tritij i C''1

Effects of Incorporated Radioactivity and External Radiation on Heterogeneous Catalysis; Effets de la radioactivite incorporee et des rayonnements externes sur la catalyse heterogene; Vliyanie vvedennoj radioaktivnosti i vneshnego oblucheniya na geterogennyj kataliz; Efectos de la radiactividad incorporada y de la irradiacion externa sobre la catalisis heterogenea

Energy Technology Data Exchange (ETDEWEB)

Krohn, N. A.; Wymer, R. G. [Oak Ridge National Laboratory, Oak Ridge and University of Tennessee, Knoxville, Tennessee (United States)

1963-11-15

aktivirovannykh alyumokhromovykh katalizatorakh. Izucheny ehffekty vvedeniya v katalizator radioaktivnykh izotopov i predvaritel'nogo gamma-oblucheniya ot istochnika Co''6''0. Sud'fatmagnievyj katalizator i katalizator smeshannogo tipa sul'fat magniya + sul'fat natriya, soderzhashchie do 45,5 mkkyuri (S''3''5)/r, pri raschete na edinitsu poverkhnosti menee aktivny, chem katalizatory togo zhe sostava, no ne soderzhashchie radioaktivnykh izotopov. Oslablenie kataliticheskoj aktivnosti sokhranyalos' dazhe posle togo, kak radioaktivnost' sushchestvenno pala, dalee, pri obluchenii rentgenovskimi luchami, kotoroe provodilos' v protsesse reaktsii, nikakikh izmenenij v kataliticheskoj aktivnosti ne nablyudalos'. Na osnovanii ehtikh dannykh sdelan vyvod, chto ehmissiya beta-chastits iz katalizatora v protsesse ego ispol'zovaniya ne okazyvaet nikakogo vliyaniya. Soobshcheniya ob usilenii kataliticheskoj aktivnosti sleduet otnesti za schet togo, chto pri prigotovlenii katalizatorov u tekh iz nikh, kotorye soderzhali radioaktivnye izotopy, vozmozhno poluchalas' bol'shaya ploshchad' poverkh- nosti, chem u tekh, kotorye ne soderzhali radioaktivnykh izotopov. Ehto obstoyatel'stvo ne bylo prinyato vo vnimanie. Predvaritel'noe gamma-obluchenie ot istochnika Co''6''0 dozoj 10''1''1 erg/g ne okazalo vliyaniya na kataliticheskuyu aktivnost'. S drugoj storony, predvaritel'noe obluchenie gamma-luchami ot istochnika Co{sup 60} alyumokhromovykh katalizatorov dozoj 4,2 x 10{sup 11} erg/g usililo kataliticheskuyu aktivnost' pochti na 34%, pri 485{sup o}C. V to zhe vremya vvedenie v katalizator do 148 mkkyuri (Pm{sup 147} )/g katalizatora ne okazyvalo pochti nikakogo vozdejstviya. V ehtom sluchae ne nablyudalos' skol'ko-nibud' zametnogo vliyaniya izlucheniya na ploshchad' poverkhnosti ili na kazhushchuyusya ehnergiyu aktivatsii. (author)

Effects of Radiation on Germ Cells of Insects: Dominant Lethals, Gamete Inactivation and Gonial-Cell Killing; Effets des rayonnements sur les cellules germinales des insectes: letalite dominante, inactivation des gametes et destruction des cellules des gonades; Vozdejstvie radiatsii na polovye kletki nasekomykh: dominantnye letali, inaktivatsiya gamet i umershchvlenie polovykh kletok; Efectos de las radiaciones sobre las celulas germinales de los insectos: elementos letales dominantes, inactivacion de los gametos y exterminacion de las celulas gonadicas

Energy Technology Data Exchange (ETDEWEB)

Von Borstel, R. C. [Biology Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

1963-09-15

esterilizacion que alcanzan su maxima eficacia solo en las especies que copulan una vez. Para que la lucha contra los insectos sea eficaz hay que aplicar dosis que produzcan un factor letal dominante maximo, una inactivacion minima de la esperma y una exterminacion completa de las celulas gonadicas. Estos parametros se pueden determinar facilmente con la medicion de la viabilidad de los gametos, los experimentos con poblaciones irradiadas y no irradiadas y el examen histologico de las gonias. (author) [Russian] Izlucheniya i khimicheskie mutagennye veshchestva umershchvlyayut kletki razlichnymi putyami:odnim iz vidov obrazovaniya dominantnykh letalej, neposredstvennoj inaktivatsiej funktsii, kak, naprimer, v otnoshenii spermy, i geneticheski neopredelimymi vidami smerti, kotorye mogut byt' svyazany ili ne svyazany s dominantnoj letal'nost'yu. Khimicheskie mutageny proizvodyat, po-vidimomu, neobychajnoe usilenie oplodotvoryaptsej sposobnosti spermy. Razlichnye stadii oogeneza i spermatogeneza reagiruyut s neodinakovoj chuvstvitel'nost'yu na obluchenie, i raznitsa v chuvstvitel'nosti otdel'nykh kletok na nekotorykh stadiyakh razvitiya dostigaet 50 raz. Razlichnye stadii oogeneza i spermatogeneza reagiruyut s neodinakovoj chuvstvitel'nost'yu na obluchenie, i raznitsa v chuvstvitel'nosti otdel'nykh kletok na nekotorykh stadiyakh razvitiya dostigaet 50 raz. Tam, gde predstavlyaetsya vozmozhnym sravnivat' dvukrylykh, pereponchatokrylykh i zhestkokrylykh nasekomykh, mozhno nablyudat' zamechatel'noe edinoobrazie reaktsii ka obluchenie kak po urovnyu radiochuvstvitel'nosti na opredelennoj stadii, tak i po zavisimosti stepeni reaktsii ot dozy. Shelkopryad, Bombyx mori (otryad cheshuekrylykh), predstavlyaetsya pokhozhim v bol'shinstve otnoshenij na predstavitelej drugikh otryadov po reaktsii polovykh kletok na radiatsiyu, no rezko otlichaetsya po tipam indutsirovannykh dominantnykh letalej. Vidy s atipichnym geneticheskim mekhanizmom (naprimer, lekanoidnaya sistema Planococcus citri

Quantitative Evaluation of Dose-Response Relationships in Human Beings with Skeletal Burdens of Radium-226 and Radium-228; Evaluation Quantitative de la Relation entre Dose et Reponse chez des Sujets Ayant une Charge Squelettique de Radium 226 et Radium 228; 041a 041e 041b 0414 ; Evaluacion Cuantitativa de las Relaciones Dosis-Respuesta en Seres Humanos con Cargas de Radio-226 y Radio-228 en el Esqueleto

Energy Technology Data Exchange (ETDEWEB)

Maletskos, C. J.; Braun, A. G.; Shanahan, M. M.; Evans, R. D. [Radioactivity Center, Department of Physics. Massachusetts Institute of Technology, Cambridge, MA (United States)

1964-11-15

izucheny na osnove dannyh klinicheskih obsledovanij, takih kak: rentgenoskopija, obsledovanie opuholej, perelomov, analizy mochi, gematologicheskie izmenenija, himicheskij analiz krovi i jelektroforez belkov. Doza vnutrennego obluchenija podschityvaetsja i vyrazhaetsja v sledujushhih edinicah; mikrokjuri jekvivalenta minimal'no chistogo radija-226 (MPRE) dlja podscheta sodeozhanija radioaktivnosti, zaderzhannoj v organizme, kumuljativnye rady i kumuljativnye rady-gody. Na pervom jetape analiza opredeljajut, sushhestvuet li svjaz' mezhdu kakim-libo klinicheskim parametrom i dozoj radiacii. Jeto opredelenie provoditsja pri pomoshhi sluchajnogo analiza, na osnovanii kotorogo fakticheskie dannye sravnivajutsja s zaranee sostavlennoj model'ju nezavisimosti mezhdu jetimi dvumja peremennymi. Esli nezavisimost' ne obnaruzhivaetsja, to dopuskaetsja sushhestvovanie nekotoroj svjazi i poluchajut kolichestvennuju harakteristiku jetoj zavisimosti. Dlja vyvedenija kojefficientov i standartnyh otklonenij ot jetih kojefficientov stepennogo rjada primenjaetsja metod krivoj naimen'shih kvadratov. Podobnoe vyrazhenie daet impericheskuju kolichestvennuju harakteristiku rezul'tatov narjadu so stepen'ju ih izmenchivosti, ono prigodno dlja provedenija bespristrastnogo sravnenija s rezul'tatami drugih laboratorij, no ne oznachaet nikakogo biofizicheskogo mehanizma. S cel'ju orpedelenija zavisimosti dozy ot obluchenija klinicheskie dannye, poluchennye u jetih pacientov,sravnivajutsja s dannymi, poluchennymi u zdorovyh ljudej s normal'nym soderzhaniem radija. Predvaritel'nye rezul'taty pokazyvajut, chto opredelenie dozy rentgenovskogo izluchenija demonstriruet jasno vyrazhennoe sootnoshenie s dozoj vnutrennego obluchenija . Polucheny opredelennye dannye o porazhenii drugih uchastkov, krome kostnoj tkani, pri vysokom soderzhanii izotopov v organizme, osobenno dannye o chisle limfocitov i skorosti osedanija jeritrocitov, chto sovpadaet s dannymi, poluchennymi na sobakah v laboratorii v Jute

Effect of {alpha}-Particle and X-Ray Irradiation on DNA Synthesis in Tissue Cultures; Effet de l'Irradiation par les Particules a et par les Rayons X sur la Synthese de l'ADN dans des Cultures de Tissus; 0412 043b 0438 044f 0414 ; Efectos de la Irradiacion con Particulas Alfa y con Rayos X sobre la Sintesis de ADN en Cultivos de Tejidos

Energy Technology Data Exchange (ETDEWEB)

Smith, C. L. [Department of Radiotherapeutics, University of Cambridge, Cambridge (United Kingdom)

1962-02-15

hipotesis de que el blanco representa la estructura tipo del ADN (o quiza del ADNP dado el elevado peso molecular en uno de los casos). Si los efectos descritos constituyen indices de los danos ocasionados a la estructura tipo del ADN (o del ADNP) durante la fase exponencial de la sintesis, los resultados 1), 2) y 3) serian los' corolarios logicos de este hecho. (author) [Russian] Daetsja opisanie vlijanija kak al'fa-chastic, tak i rentgenovskogo obluchenija na skorost' sinteza DNK v fibr.oblaste myshej v kletkah Hela v kul'tirovannoj tkani. Byla ispol'zovana tritirovannaja timidinom mikroavtografija s celbju opredelenija skorosti sinteza v odnom spoe kul'tivirovannoj tkani. Rezul'taty jeksperimentov pokazali, chto: 1. Na zhrakciju kletok v kulbtivirovannoj, sintezirujushhej DNK, ne vlijajut al'fa-chasticy i rentgenovskie luchi v teh dozah, kotorye ispol'zovanlis' pri jeksperimente. 2. Vlijanie kazhdogo tipa obluchenija zakljuchaetsja v umen'shenii skorosti sinteza DNK obluchennyh v processe sinteza kletok. 3. Vlijanie dannoj dozy ljubogo vida radiacii zakljuchaetsja v sokrashhenii sko- rosti sinteza vseh kletok do postojannoj frakcii, kotoraja imela mesto v neobluchennyh kletkah. 4. Skorost' sinteza DNK sokrashhaetsja do 37 % (1/e) s pomoshh'ju dozy sa. 25 al'fa//gg ili dozy rentgenovskih luchej moshhnost'ju v 14,000 rad dlja rosta fibroblasta u myshi. V kul'turah Hela dlja sokrashhenija skorosti sinteza DNK do 37 % pervonachal'nogo znachenija neobhodima doza sa. 90,000 rad. 5. Umen'shenie sinteza imeet mesto ne bolee chem polchasa posle obluchenija i mozhet projavit'sja nemedlenno. Iz punkta 4 vyshe mozhno pribliziteln'o podschitat' konfiguraciju misheni, i esli predpolozhit' ee cilindricheskoj, to ona dolzhna imet' razmery sa. 16 A v odnom napravpenii i 16 000 A-v drugom, t. e. dlinnuju tonkuju nit' s mole- kuljarnym vesom porjadka 5 * 10{sup 7} pri jeksperimentah s fibroblastom myshi. Pri provedenii jeksperimenta s kletkoj Hela ob{sup e}m soderzhimogo misheni pozvoljaet

Radioisotope Power Sources; Sources d'energie utilisant les radiobotopes; Radioizotopnye istochniki ehnergii; Fuentes radio isotopicas de energia

Energy Technology Data Exchange (ETDEWEB)

Culwell, J. P. [USAEC, Washington, D.C (United States)

1963-11-15

realizando investigaciones con generadores alimentados por mezclas de productos de fision. Estas seran menos costosas que los radioisotopos puros, pues se suprimen los gastos de separacion y purificacion de isotopos. En la actualidad funcionan o estan a punto de funcionar generadores termoelectricos prototipo, alimentados con estroncio-90 y cesio-137, en estaciones meteorologicas, dispositivos auxiliares de navegacion y aparatos de vigilancia de las profundidades del mar. En el espacio funcionan generadores termoelectricos de plutonio-238 como fuentes de energia electrica del satelite TRANSIT de la Marina de los Estados Unidos. Se estan construyendo asimismo generadores para los proyectos espaciales de la National Aeronautics and Space Administration de dicho pais. La elevada radiactividad inherente a las fuentes radioisotopicas de energia exige que se preste especial atencion a la seguridad de las mismas. Se han establecido rigurosas normas de proteccion y se han ejecutado ensayos muy avanzados para poder emplear estos dispositivos sin originar riesgos inaceptables. (author) [Russian] Programma ispol'zovaniya radioaktivnykh izotopov v kachestve ehnergeticheskogo syr'ya, razrabotannaya Komissiej po atomnoj ehnergii SSHA, privela k sozdaniyu sovershenno novoj tekhnologii primeneniya radioizotopov v kachestve istochnikov ehnergii v generatorakh ehlektroehnergii. Sistema radioizotopnykh ehnergeticheskikh stantsij osobenno nuzhna tam, gde vvidu krajnej otdalennosti trebuyutsya dolgovechnye, nadezhnye i malogabaritnye silovye ustanovki. Sposobnye udovletvoritel'no funktsionirovat' v tyazhelykh usloviyakh, naprimer pri dejstvii temperatur, solnechnogo sveta i ehlektromagnitnogo izlucheniya, takie ''atomnye batarei'' yavlyayutsya zamanchivymi istochnikami ehnergii dlya ustanovok, sobirayushchikh informatsiyu na rasstoyanii, dlya upravlyayushchikh sistem, dlya iskustvennykh sputnikov i drugikh kosmicheskikh ob{sup e}ktov. Radioizotopy, primenyayushchiesya v kachestve goryuchego

100-Mc counting system; Ensemble de comptage a 100 megacycles; Schetnaya sistema na 100 megatsiklov; Sistema contador de 100 megaciclos

Energy Technology Data Exchange (ETDEWEB)

Sugarman, R; Higinbotham, W A; Yonda, A H [Brookhaven National Laboratory, Upton, Long Island, NY (United States)

1962-04-15

zaderzhki; maksimal'nyj rabochij tsikl na vykhode raven 50% pri 95% vosstanovleniya na vkhode. Razbros vremeni ot porogovogo izlucheniya do velichiny v tri raza bol'shej sostavlyaet 2 nanosekundy i menee. CHuvstvitel'nost' bolee slozhnogo varianta v 10 raz bol'she. EHtot variant imeet rasprostranennyj usilitel' i vklyuchayushchuyu tsep' iz dvukh tunnel'nykh diodov. Vykhodnye kharakteristiki te zhe samye. Budut takzhe rassmotreny drugie logicheskie sistemy dlya diskriminatorov. SHkala na 8 delenij imeet dvoichnyj tunnel'nyj diod. Pervyj iz nikh (nestandartno) napravlyaetsya s pomoshch'yu obychnykh diodov. Bolee pozdnie stadii predstavlyayut soboj bolee ili menee tipichnuyu tunnel'nuyu diodnuyu logicheskuyu sistemu. (author)

High-Dose Ionizing Radiation Photographic Dosimetry; Mesure, par des Methodes Photogra Phiques, de Doses Elevees de Rayonnements Ionisants; 0424 041e 0422 041e 0413 0420 0414 ; Dosimetria Fotografica de Dosis Elevadas de Radiaciones Ionizantes

Energy Technology Data Exchange (ETDEWEB)

Trousil, J.; Bucina, I. [Institute for Research Production and Application of Radioisotopes Prague, Czechoslovakia (Czech Republic)

1965-06-15

potemnenija fotoplenki. Blagodarja tomu, chto ne byl ispol'zovan fotouvelichitel', minimal'no sokrashhena vozmozhnaja perederzhka pribora, chto udobno dlja obychnyh standartnyh izmerenij. Krome togo, privodjatsja parametry, kotorye dolzhny imet' dozimetricheskie plenki, chtoby byt' prigodnymi dlja obnaruzhenija bol'shih doz, a takzhe proizvoditsja sravnenie mezhdu kachestvom dozimetricheskih plenok FOMA i ORWO pri sluchajnom obluchenii. Dlja izmerenija doz bol'shoj moshhnosti uspeshno primenjalsja metod zatormozhennogo projavlenija, kotoryj opisyvaetsja v dal'nejshem i pri kotorom v projavitele byli ispol'zovany veshhestva tipa nitrobenzimida- zola i benztriazola v sootvetstvujushhih koncentracijah. V sluchae ispol'zovanija jemul'sii nebol'shoj chuvstvitel'nosti s bol'shim soderzhaniem serebra jetot metod pozvoljaet proizvodit' izmerenie doz gamma-izluchenija (rentgenovskogo izluchenija bolee vysokoj jenergii) vplot' do 10{sup 3} rad, a esli net neobhodimosti v opredelenii dozy - s tochnost'ju do 100 rad, to i vyshe. Pokazyvaetsja zatormazhivajushhee dejstvie himikaliev, dobavljaemyh v projavitel', na jemul'siju vysokoj i nizkoj chuvstvitel'nosti s bol'shim soderzhaniem serebra, kotorye ispol'zujutsja v dozimetrii. V jemul'sijah, kotorye ispol'zujutsja dlja izmerenija doz bol'shoj moshhnosti i kotorye projavljajut v projavitele s dobavleniem zatormazhivajushhih himikaliev, ustanovleno vlijanie zavisimosti ot jenergii i obescvechivanija skrytogo izobrazhenija na tochnost' izmerjaemyh doz. V zakljuchenie opisyvajutsja pogreshnosti fotograficheskoj dozimetrii bol'shih doz, kotorye obnaruzheny na osnove principa jeksperimental'nyh rabot posredstvom matematicheskoj statistiki. Uchityvaetsja uvelichenie pogreshnostej v diapazone neznachitel'nogo i bol'shogo potemnenija plenki. Uchityvajutsja takzhe pogreshnosti, obuslovlennye kalibrovkoj, zavisimost'ju ot jenergii, obescvechivaniem skrytogo izobrazhenija, himicheskoj obrabotkoj i izmereniem potemnenija. Ne uchityvaetsja pogreshnost

Shippingport Atomic Power Station Operating Experience, Developments and Future Plans; La centrale nucleaire de Shippingport, experience de son fonctionnement et plans pour l'avenir; Shippingportskaya atomnaya ehlektrostantsij, opyt ehkspluatatsii, usovershenstvovaniya i plany na budushchee; Central nucleoelectrica de Shippingport; experiencia adquirida con su explotacton y programa de desarrollo

Energy Technology Data Exchange (ETDEWEB)

Feinroth, H. [Division of Reactor Development, United States Atomic Energy Commission, Washington, DC (United States); Oldham, G. M. [Shippingport Atomic Power Station, Duquesne Light Company, Pittsburgh, PA (United States); Stiefel, J. T. [Bettis Atomic Power.Labora Tory, Westinghouse Electric Corporation, Pittsburgh, PA (United States)

1963-10-15

'mennykh administrativnykh instruktsij, rukovodstv po ehnergeticheskoj ustanovke i t.d., chto yavilos' ochen' vazhnym faktorom v uspeshnom osushchestvlenii programmy ispytanij SHippingportskoj ehlektrostantsii. Rezul'taty ispytanij khorosho sovpadayut s raschetnymi dannymi. Rassmatrivayutsya rabota aktivnoj zony reaktora, stabil'nost' ustanovki, chuvstvitel'nost' k izmeneniyam nagruzki, rabota toplivnykh ehlementov i reguliruyushchikh sterzhnej, povyshenie takikh dlitel'nykh ehffektov, kak korroziya i intensivnost' izlucheniya, rabota komponentov i t.d. Rassmatrivaetsya osnovnaya tsel' tekushchej i budushchej programm Shippingportskogo proekta v otnoshenii usovershenstvovaniya osnovnoj tekhnologii reaktorov s vodyanym okhlazhdeniem. Ehta programma vklyuchaet prodolzhenie ehkspluatatsii Shippingportskoj ustanovki, razrabotku, konstruirovanie, izgotovlenie i opytnuyu ehkspluatatsiyu vtoroj aktivnoj zony (aktivnaya zona 2), imeyushchej dlitel'nyj srok sluzhby i vysokuyu plotnost' ehnergovydeleniya. Imeya proektnuyu ehlektricheskuyu moshchnost' brutto 150 mgvt i prodolzhitel'nost' sluzhby pervoj zapal'noj sborki 10 tys. chasov raboty na polnoj moshchnosti, aktivnaya zona 2 budet v pyat' s polovinoj raz moshchnee aktivnoj zony 1 i obladat' v dva raza bol'shej plotnost'yu ehnergovydeleniya, chem poslednyaya. Daetsya opisanie konstruktsii aktivnoj zony 2 i svyazannykh s nej osnovnykh usovershenstvovanij v fizike reaktora, metallurgii, teploperedache, podache teplonositelya i izgotovlenii toplivnykh ehlementov. Izlozheny plany v otnoshenii dezaktivatsii reaktornoj ustanovki i osushchestvleniya ee modifikatsii v svyazi s ustanovkoj bolee moshchnoj aktivnoj zony 2. (author)

Radiation-pulse transmission via a long cable without a preamplifier and/or a pulse transformer; Transmission d'impulsions de rayonnement par cable long sans l'adjonction d'un preamplificateur ou d'un transformateur d'impulsions; Peredacha impul'snykh izluchenij no kabelyu na dal'nie rasstoyaniya bez predvaritel'nogo usileniya i/ili bez preobrazovaniya impul'sov; Transmision de impulsos por cables de gran longitud sin preamplificador y/o transformador de impulsos

Energy Technology Data Exchange (ETDEWEB)

Miwa, H; Tohyama, T [Kobe Kogyo Corporation, Okubo, Akashi, Hyogo (Japan)

1962-04-15

vkhodnym konturam malogo vkhodnogo kompleksnogo soprotivleniya, prikhoditsya neskol'ko peresmatrivat' ehti kontury. Rassmatrivayutsya i sravnivayutsya drug s drugom tri vkhodnykh kontura, a imenno (No. 1) po vidu napryazheniya, (No. 1) po vidu napryazheniya i toka i (No. 3) po vidu toka. Kontur No. 1 ochen' pokhozh na obychnyj kontur s ehlektronnymi lampami. Byl postroen chuvstvitel'nyj sledyashchij mekhanizm izlucheniya al'fa-luchej s katodnoj nagruzkoj i so smeshcheniem obratnoj svyazi; on byl uspeshno ispol'zovan bez ushcherba dlya ustojchivosti postoyannogo toka v kachestve kontura s bol'shim vkhodnym kompleksnym soprotivleniem svyshe 10 megaomov. Bol'shaya chast' radiatsionnykh detektorov mozhet rassmatrivat'sya kak generatory toka. Takim obrazom, vykhodnye signaly detektorov mogut napravlyat'sya v usilitel' toka s malym vkhodnym kompleksnym soprotivleniem. EHto ustrojstvo sootvetstvuet vidu No. 3, i ono daet velikolepnuyu amplitudu impul'sa, no vvidu bystrogo toka impul'sov i maloj vkhodnoj integriruyushchej konstanty vremeni verkhnij predel chastoty usilitelya dolzhen prevyshat' 10 megagerts. Ustrojstvo No. 2 yavlyaetsya kombinatsiej vidov No. 1 i No. 3. Signaly detektora napravlyayutsya cherez soprotivlenie priblizitel'no v 100 kiloomov v usilitel' toka s malym vkhodnym kompleksnym soprotivleniem. Soprotivlenie izmenyaet vkhodyashchuyu integriruyushchuyu konstantu vremeni do nuzhnoj velichiny i snizhaet trebovaniya, pred{sup y}avlyaemye k verkhnemu predelu chastoty ehlektronnogo kontura priblizitel'no do 2 megagerts. Bolee togo, ehto ustrojstvo pozvolyaet sokhranit' proportsional'noe sootnoshenie mezhdu amplitudoj impul'sa i ehnergiej radiatsii. Omicheskoe soprotivlenie sluzhit takzhe predokhranitel'nym ustrojstvom dlya gazovykh detektorov. Kabel', soedinyayushchij soprotivlenie s usilitelem toka, mozhet byt' prolozhen na rasstoyanie bolee 500 metrov bez iskazheniya formy impul'sa, pri uslovii ispol'zovaniya koaksial'nogo kabelya i pri uslovii, chto vkhodnoe

Distribution of Aerially Applied Malathion-S{sup 35} in a Forest Ecosystem; Distribution du malathion- {sup 35}S pulverise par avion dans un ensemble ecologique forestier; Raspredelenie malationa, mechennogo S35 i raspylyaemogo s vozdukha dlya izucheniya ehkologicheskoj sistemy lesnykh massivov; Distribucion en un sistema ecologico forestal de malation- 35S pulverizado desde el aire

Energy Technology Data Exchange (ETDEWEB)

Giles, Jr., R. H.; Peterle, T. J. [Ohio Co-Operative Wildlife Research Unit, Columbus, OH (United States)

1963-09-15

insecticida pulverizado. Por toma de muestras de tierra y recuento de zonas delimitadas se estudio la distribucion bajo la superficie del suelo. Las muestras de agua tomadas en arroyos intermitentes y los ensayos realizados con insectos, mamiferos, reptiles y aves indicaron la distribucion inicial y subsiguiente del insecticida y sus metabolitos en el sistema ecologico. Los estudios de la poblacion animal siguieron durante los veranos de 1961 y 1962; en el verano de 1963 se reuniran todavia algunos datos. Los resultados preliminares indican que la poblacion de insectos vuelve a la normalidad unas tres semanas despues del tratamiento; no se observo efecto alguno en los animales vertebrados de la zona tratada. (author) [Russian] Raspredelenie malationa (0,0-dimetilditiofosfat diehtilmerkaptoyantarnoj kisloty) v lesnom massive vostochnoj chasti Tsentral'nogo Ogajo, SSHA, izuchalos' vesnoj 1962 goda. Ehtot insektitsid shirokogo dejstviya byl vybran dlya izucheniya v svyazi s ego vozrastayushchej rol'yu v bor'be s mnogimi vazhnymi nasekokymi-vreditelyami listvennykh i khvojnykh lesov Soedinennykh Shtatov. Dlya rasshireniya znanij po ehkologii lesnykh massivov, a takzhe bolee polnogo ponimaniya vliyaniya insektitsidov na faunu byla ispol'zovana svoeobraznaya vozmozhnost' izucheniya ehtikh problem odnovremenno posredstvom primeneniya mechennykh izotopami insektitsidov. S{sup 35} byla vybrana vvidu nizkoj ehnergii beta-izlucheniya (0,167 Mehv) i dostatochno korotkogo perioda poluraspada (87,1 dnya). Predvaritel'noe issledovanie uchastka zemli 0,1 akra letom 1961 goda pokazalo stepen' vozmozhnogo' primeneniya v usloviyakh obshchej radiatsii, a takzhe vozmozhnost' razrabotat' podgotovitel'nye metody dlya vzyatiya prob. Letom 1961 goda byl proveden obzor fauny dvukh bassejnov reki ploshchad'yu v 20 akrov kazhdyj. V mae 1962 goda odin iz nikh byl obrabotan tekhnicheski-chistym malationom v kolichestve 2 funtov na 1 akr v smesi s ksilolom, tritonom X-155 (ehmul'gator) i vodoj. Malation

Turbulent Heating of Plasma by a Direct-Current Discharge; Chauffage Turbulent du Plasma par le Courant d'une Decharge Directe; ТУРБУЛЕНТНЫЙ НАГРЕВ ПЛАЗМЫ ТОКОМ ПРЯМОГО РАЗРЯДА; Calentamiento Turbulento del Plasma por una Corriente de Descarga Directa

Energy Technology Data Exchange (ETDEWEB)

Babykin, M. V.; Gavrin, P. P.; Zavojskij, E. K.; Rudakov, L. I.; Skorjupin, V. A. [Institut Atomnoj Ehnergii Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

1966-04-15

'naja chast' jEhnergii kondensatora prjamogo razrjada. Nabljudalos' sil'noe shumovoe izluchenie ot 10{sup 6} d o 4 * 10{sup 10} gerc. SVCh shumy dljatsja dol'she, chem nizkochastotnye shumy na oscillogrammah toka. Jeto svidetel'stvuet, chto neustojchivost' sushhestvuet i posle perehoda v kolebatel'nyj rezhim. Temperatura plazmy opredeljalas' po zhestkosti tormoznogo rentgenovskogo izluchenija i ravna 5 - 10 kjev. Plotnost' opredeljalas' mikrovolnovym interferometrom. Davlenie plazmy ocenivalos' po diamagnitnomu jeffektu i okazalos' Tilde-Operator 10{sup 17} jev sm{sup -3} . Otsjuda pri p Greater-Than-Or-Equivalent-To 2 * 10{sup 13} sm{sup -3} poluchaetsja temperatura Tilde-Operator 5 kjev, chto soglasuetsja s drugimi izmerenijami. Pri plotnosti nagretoj plazmy menee 10{sup 13} sm{sup -3} plazma adiabaticheski szhimaetsja, ostavajas' ustojchivoj. Temperatura jelektronov posle szhatija dostigaet 200 kjev. Pri uvelichenii nachal'noj plotnosti plazmy temperatura posle nagreva nizhe i szhatie ne proishodit. Issledovano prohozhdenie signala s chastotoj 3 * 10{sup 8} gerc cherez plazmu vo vremja neustojchivosti toka. Pokazano, chto v plazme s sil'noj turbulentnost'ju tolshhina skin-sloja znachitel'no bol'she c/{omega}{rho}. Daetsja ob'jasnenie jetomu javleniju. Obsuzhdaetsja mehanizm nagreva plazmy pri neustojchivosti toka. Podobnaja teorija jetogo javlenija daetsja v otdel'nom doklade. (author)

Radioisotopes and Radiation in Animal and Plant Insect Pest Control; Emploi des radioisotopes et des rayonnements dans la lutte contre les insectes nuisibles aux plantes et aux animaux; Ispol'zovanie radioizotopov i radiashchi v bor'be s nasekomymi-vreditelyami rastenij i zhivotnykh; Utilizacion de los radioisotopos y de las radiaciones en la lucha contra los insectos nocivos para las plantas y los animales

Energy Technology Data Exchange (ETDEWEB)

Andreev, S. V.; Martens, B. K.; Samojlova, V. A.; Molchanova, Z. I. [Vsesoyuznyj Institut Zashchity Rastenij, Leningrad, SSSR (Russian Federation)

1963-09-15

plagas de insectos. La accion esterilizadora y letal de las radiaciones ionizantes puede ser muy eficaz en la lucha contra las plagas de insectos. Utilizando rayos gamma se han establecido las dosis esterilizadoras para toda una serie de insectos nocivos para los productos agricolas almacenados (Calandra granaria L., Acanthoscelides Obtectus Say, Pectinophora Malvella Hb., Leptinotarsa decemlineota Say, Chloridea obsoleta F.) y los cultivos. Los datos obtenidos con esas investigaciones serviran de base para elaborar y perfeccionar los metodos de lucha contra los insectos daninos para la agricultura. (author) [Russian] Problema bor'by s vreditelyami sel'skokhozyajstvennykh kul'tur imeet krupnoe narodnokhozyajstvennoe znachenie. Pri razreshenii ehtoj problemy osoboe znachenie priobretaet ispol'zovanie poslednikh dostizhenij nauki. V tselyakh ratsionalizatsii i povysheniya ehffektivnosti sushchestvuyushchikh metodov bor'by s vrednymi nasekomymi byli ispol'zovany radioaktivnye izotopy i izlucheniya. Ispol'zovanie radioaktivnykh izotopov i izluchenij yavlyaetsya moguchim sredstvom ratsionalizatsii i'povysheniya ehffektivnosti sushchestvuyushchikh metodov bor'by s vrednymi nasekomymi. Razrabotka ehtikh metodov vyzyvaet neobkhodimost' detal'nogo izucheniya voprosov bioehkologii, toksikologii i t.d. V oblasti bioehkologii ves'ma perspektivnym yavlyaetsya metod radiomarkirovki nasekomykh. Primenenie radioizotopov dlya markirovki nasekomykh vreditelej zernovykh kul'tur (Eurygaster integriceps Put, Hadena sordida Skh.) i ikh parazitov (Meniscus agriatus Crow, Psendogonia cinerascens Rond.) pozvolilo ustanovit' razmery migratsij ikh, opredelit' mesta rezervatsij, chislennost' populyatsij i izuchit' voprosy pitaniya ukazannykh parazitov vrednykh nasekomykh. Ehtim khe metodom byla ustanovlena dinamika rasprostraneniya karantinnogo ob{sup e}kta kartofel'nogo khuka (Leptinotarsa decemlineota Say), chto pozvolilo poluchit' neobkhodimye dannye dlya provedeniya istrebitel'nykh meropriyatij