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Sample records for tierra lumbricus terrestris

  1. Incorporation of microplastics from litter into burrows of Lumbricus terrestris

    NARCIS (Netherlands)

    Huerta Lwanga, Esperanza; Gertsen, H.F.; Gooren, H.; Peters, P.; Salanki, T.E.; Ploeg, van der M.; Besseling, E.; Koelmans, A.A.; Geissen, V.

    2017-01-01

    Pollution caused by plastic debris is an urgent environmental problem. Here, we assessed the effects of microplastics in the soil surface litter on the formation and characterization of burrows built by the anecic earthworm Lumbricus terrestris in soil and quantified the amount of microplastics that

  2. Microplastics in the terrestrial ecosystem: Implications for Lumbricus terrestris (Oligochaeta, Lumbricidae)

    NARCIS (Netherlands)

    Huerta Lwanga, Esperanza; Gertsen, H.F.; Gooren, H.; Peters, P.D.; Salanki, T.E.; Ploeg, van der M.J.C.; Besseling, E.; Koelmans, A.A.; Geissen, V.

    2016-01-01

    Plastic debris is widespread in the environment, but information on the effects of microplastics on terrestrial fauna is completely lacking. Here, we studied the survival and fitness of the earthworm Lumbricus terrestris (Oligochaeta, Lumbricidae) exposed to microplastics (Polyethylene, <150 μm)

  3. Microplastics in the Terrestrial Ecosystem: Implications for Lumbricus terrestris (Oligochaeta, Lumbricidae).

    Science.gov (United States)

    Huerta Lwanga, Esperanza; Gertsen, Hennie; Gooren, Harm; Peters, Piet; Salánki, Tamás; van der Ploeg, Martine; Besseling, Ellen; Koelmans, Albert A; Geissen, Violette

    2016-03-01

    Plastic debris is widespread in the environment, but information on the effects of microplastics on terrestrial fauna is completely lacking. Here, we studied the survival and fitness of the earthworm Lumbricus terrestris (Oligochaeta, Lumbricidae) exposed to microplastics (Polyethylene, digestion of ingested organic matter, microplastic was concentrated in cast, especially at the lowest dose (i.e., 7% in litter) because that dose had the highest proportion of digestible organic matter. Whereas 50 percent of the microplastics had a size of earthworms. These concentration-transport and size-selection mechanisms may have important implications for fate and risk of microplastic in terrestrial ecosystems.

  4. Incorporation of microplastics from litter into burrows of Lumbricus terrestris.

    Science.gov (United States)

    Huerta Lwanga, Esperanza; Gertsen, Hennie; Gooren, Harm; Peters, Piet; Salánki, Tamás; van der Ploeg, Martine; Besseling, Ellen; Koelmans, Albert A; Geissen, Violette

    2017-01-01

    Pollution caused by plastic debris is an urgent environmental problem. Here, we assessed the effects of microplastics in the soil surface litter on the formation and characterization of burrows built by the anecic earthworm Lumbricus terrestris in soil and quantified the amount of microplastics that was transported and deposited in L. terrestris burrows. Worms were exposed to soil surface litter treatments containing microplastics (Low Density Polyethylene) for 2 weeks at concentrations of 0%, 7%, 28%, 45% and 60%. The latter representing environmentally realistic concentrations found in hot spot soil locations. There were significantly more burrows found when soil was exposed to the surface treatment composed of 7% microplastics than in all other treatments. The highest amount of organic matter in the walls of the burrows was observed after using the treatments containing 28 and 45% microplastics. The highest microplastic bioturbation efficiency ratio (total microplastics (mg) in burrow walls/initial total surface litter microplastics (mg)) was found using the concentration of 7% microplastics, where L. terrestris introduced 73.5% of the surface microplastics into the burrow walls. The highest burrow wall microplastic content per unit weight of soil (11.8 ± 4.8 g kg- 1 ) was found using a concentration of 60% microplastics. L. terrestris was responsible for size-selective downward transport when exposed to concentrations of 7, 28 and 45% microplastics in the surface litter, as the fraction ≤50 μm microplastics in burrow walls increased by 65% compared to this fraction in the original surface litter plastic. We conclude that the high biogenic incorporation rate of the small-fraction microplastics from surface litter into burrow walls causes a risk of leaching through preferential flow into groundwater bodies. Furthermore, this leaching may have implications for the subsequent availability of microplastics to terrestrial organisms or for the transport

  5. Lumbricus terrestris L. activity increases the availability of metals and their accumulation in maize and barley

    International Nuclear Information System (INIS)

    Ruiz, E.; Alonso-Azcarate, J.; Rodriguez, L.

    2011-01-01

    The effect of the earthworm Lumbricus terrestris L. on metal availability in two mining soils was assessed by means of chemical extraction methods and a pot experiment using crop plants. Results from single and sequential extractions showed that L. terrestris had a slight effect on metal fractionation in the studied soils: only metals bound to the soil organic matter were significantly increased in some cases. However, we found that L. terrestris significantly increased root, shoot and total Pb and Zn concentrations in maize and barley for the soil with the highest concentrations of total and available metals. Specifically, shoot Pb concentration was increased by a factor of 7.5 and 3.9 for maize and barley, respectively, while shoot Zn concentration was increased by a factor of 3.7 and 1.7 for maize and barley, respectively. Our results demonstrated that earthworm activity increases the bioavailability of metals in soils. - Research highlights: → Lumbricus terrestris L. activity increases the bioavailability of metals in soils. → Earthworm activity can significantly increase total, shoot and root metal concentrations for crop plants. → Both bioassays and chemical extraction methods are necessary for assessing the bioavailability of metals in contaminated soils. - Lumbricus terrestris L. activity increases the bioavailability of metals in soils and total, shoot and root metal concentrations for maize and barley.

  6. On a specimen of Lumbricus terrestris, L. with bifurcated tail

    NARCIS (Netherlands)

    Horst, R.

    1886-01-01

    In the last number of the »Annals and Magazine of Nat. History” (Dec. 1885), I find a notice of Prof. Jeffrey Bell about two Lumbrici with bifid hinder ends, one specimen belonging to L. terrestris, the other to L. foetidus; moreover he mentions a specimen, presenting a similar remarquable

  7. Effect of time and mode of depuration on tissue copper concentrations of the earthworms Eisenia andrei, Lumbricus rubellus and Lumbricus terrestris

    International Nuclear Information System (INIS)

    Arnold, R.E.; Hodson, M.E.

    2007-01-01

    Eisenia andrei, Lumbricus rubellus and Lumbricus terrestris were exposed to 250, 250 and 350 mg kg -1 Cu respectively in Cu(NO 3 ) 2(aq) amended soil for 28 d. Earthworms were then depurated for 24 to 72 h, digested and analysed for Cu and Ti or, subsequent to depuration were dissected to remove any remaining soil particles from the alimentary canal and then digested and analysed. This latter treatment proved impossible for E. andrei due to its small size. Regardless of depuration time, soil particles were retained in the alimentary canal of L. rubellus and L. terrestris. Tissue concentration determinations indicate that E. andrei should be depurated for 24 h, L. rubellus for 48 h and L. terrestris should be dissected. Ti was bioaccumulated and therefore could not be used as an inert tracer to determine mass of retained soil. Calculations indicate that after 28 d earthworms were still absorbing Cu from soil. - Even after 72 h depuration earthworms retain soil particles in their alimentary canal that can bias tissue concentration determinations

  8. Effect of time and mode of depuration on tissue copper concentrations of the earthworms Eisenia andrei, Lumbricus rubellus and Lumbricus terrestris

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R.E. [Department of Soil Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom)]. E-mail: biogas@greenfinch.co.uk; Hodson, M.E. [Department of Soil Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom)]. E-mail: m.e.hodson@reading.ac.uk

    2007-07-15

    Eisenia andrei, Lumbricus rubellus and Lumbricus terrestris were exposed to 250, 250 and 350 mg kg{sup -1} Cu respectively in Cu(NO{sub 3}){sub 2(aq)} amended soil for 28 d. Earthworms were then depurated for 24 to 72 h, digested and analysed for Cu and Ti or, subsequent to depuration were dissected to remove any remaining soil particles from the alimentary canal and then digested and analysed. This latter treatment proved impossible for E. andrei due to its small size. Regardless of depuration time, soil particles were retained in the alimentary canal of L. rubellus and L. terrestris. Tissue concentration determinations indicate that E. andrei should be depurated for 24 h, L. rubellus for 48 h and L. terrestris should be dissected. Ti was bioaccumulated and therefore could not be used as an inert tracer to determine mass of retained soil. Calculations indicate that after 28 d earthworms were still absorbing Cu from soil. - Even after 72 h depuration earthworms retain soil particles in their alimentary canal that can bias tissue concentration determinations.

  9. Biophysical Properties of Lumbricus terrestris Erythrocruorin and Its Potential Use as a Red Blood Cell Substitute

    Directory of Open Access Journals (Sweden)

    Jacob Elmer

    2012-01-01

    Full Text Available Previous generations of hemoglobin (Hb-based oxygen carriers (HBOCs have been plagued by key biophysical limitations that result in severe side-effects once transfused in vivo, including protein instability, high heme oxidation rates, and nitric oxide (NO scavenging. All of these problems emerge after mammalian Hbs are removed from red blood cells (RBCs and used for HBOC synthesis/formulation. Therefore, extracellular Hbs (erythrocruorins from organisms which lack RBCs might serve as better HBOCs. This review focuses on the erythrocruorin of Lumbricus terrestris (LtEc, which has been shown to be extremely stable, resistant to oxidation, and may interact with NO differently than mammalian Hbs. All of these beneficial properties show that LtEc is a promising new HBOC which warrants further investigation.

  10. Effect of heavy metal exposure on blood haemoglobin concentration and methemoglobin percentage in Lumbricus terrestris.

    Science.gov (United States)

    Calisi, A; Lionetto, M G; Sanchez-Hernandez, J C; Schettino, T

    2011-06-01

    The earthworm haemoglobin (Hb) is a large extracellular hemoprotein flowing in a closed circulatory system. In spite of the fundamental role of this respiratory pigment in earthworm physiology, little is known about its sensitivity to environmental pollutants. The aim of the present work was to investigate the possible effect of heavy metal (cadmium, copper, mercury) exposure on Hb concentration and oxidation state (methemoglobin formation) in the earthworm Lumbricus terrestris. In addition, the tissue concentration of metallothioneins, a well-known biomarker of heavy metal exposure, was determined as an indicator of metal uptake. The animals were exposed to increasing concentrations of Cd, Cu and Hg utilizing the standard acute toxicity test, "Filter paper test" for 48 h. Exposure to heavy metals (10(-5)-10(-3) M for Cd, 10(-4)-10(-3) M for Hg, and 10(-4)-10(-2) M for Cu) was found to increase haemoglobin concentration in L. terrestris, although the magnitude of such an increase was dependent on the metal. In addition, metal exposure led to the formation of methemoglobin. Compared to other known biological responses to heavy metals, such as metallothionein induction, methemoglobin increase showed a higher sensitivity and a higher percentage variation in exposed organisms, showing to be a possible suitable biomarker of exposure/effect to be included in a multi biomarker strategy in earthworm in soil monitoring assessment.

  11. Measurement and simulation of unmyelinated nerve electrostimulation: Lumbricus terrestris experiment and numerical model.

    Science.gov (United States)

    Šarolić, A; Živković, Z; Reilly, J P

    2016-06-21

    The electrostimulation excitation threshold of a nerve depends on temporal and frequency parameters of the stimulus. These dependences were investigated in terms of: (1) strength-duration (SD) curve for a single monophasic rectangular pulse, and (2) frequency dependence of the excitation threshold for a continuous sinusoidal current. Experiments were performed on the single-axon measurement setup based on Lumbricus terrestris having unmyelinated nerve fibers. The simulations were performed using the well-established SENN model for a myelinated nerve. Although the unmyelinated experimental model differs from the myelinated simulation model, both refer to a single axon. Thus we hypothesized that the dependence on temporal and frequency parameters should be very similar. The comparison was made possible by normalizing each set of results to the SD time constant and the rheobase current of each model, yielding the curves that show the temporal and frequency dependencies regardless of the model differences. The results reasonably agree, suggesting that this experimental setup and method of comparison with SENN model can be used for further studies of waveform effect on nerve excitability, including unmyelinated neurons.

  12. Biomarker response in the earthworm Lumbricus terrestris exposed to chemical pollutants.

    Science.gov (United States)

    Calisi, A; Lionetto, M G; Schettino, T

    2011-09-15

    Earthworms are important organisms for the soil ecosystem. They are sensitive to toxic chemicals and represent useful bioindicator organisms for soil biomonitoring. Recently the use of biomarkers in earthworms has been increasingly investigated for soil monitoring and assessment purpose. The aim of the preset paper was to analyze the pollutant-induced response of a suite of cellular and biochemical biomarkers in the earthworm Lumbricus terrestris exposed to copper sulphate or methiocarb in OECD soil at the maximal concentrations recommended in agriculture. These responses were compared to lifecycle parameters such as survival, growth and reproduction. Granulocyte morphometric alteration, lysosomal membrane stability, metallothionein concentration, and acetylcholinesterase activity were considered. In either copper sulphate or methiocarb exposure conditions the mean percentage variation of the pollutant-induced molecular and cellular biomarkers was consistent with the whole organism end-point responses. In particular pollutant-induced granulocyte enlargement, detected in either copper sulphate or methiocarb exposed organisms, showed to be a potential general biomarker that may be directly linked to organism health. Compared to the other biological responses to pollutants, it showed high sensitivity to pollutant exposure suggesting its possible applications as a sensitive, simple, and quick general biomarker for monitoring and assessment applications. Copyright © 2011 Elsevier B.V. All rights reserved.

  13. Bioavailability and cellular effects of metals on Lumbricus terrestris inhabiting volcanic soils

    International Nuclear Information System (INIS)

    Amaral, Andre; Soto, Manu; Cunha, Regina; Marigomez, Ionan; Rodrigues, Armindo

    2006-01-01

    Whether the radial thickness (RT) of the chloragogenous tissue and intestinal epithelium of earthworms (Lumbricus terrestris) reflects the bioavailability of metals in soils was investigated in two areas, one with active volcanism (Furnas) and another with no volcanic activity since 3 million years ago (Santa Maria), in the Azores. Metal contents in soil samples and earthworms from the two areas were analyzed. Autometallography and measurements of the RT were performed in the chloragogenous tissue and intestinal epithelium. Earthworms from the active volcanic area demonstrated lower RT of chloragogenous tissue and intestinal epithelium as well as higher levels of bioavailable metals, especially Zn and Cd. Comparison of bioavailable metal contents between both areas suggests a higher risk for uptake of potentially toxic metals in the active volcanic area than in the non-active volcanic area, which is reflected by the lower RT of the chloragogenous tissue and intestinal epithelium in the former. - In earthworms, differences in the chloragogenous tissue morphometry may be related to the bioavailability of metals in soils

  14. Bioavailability and cellular effects of metals on Lumbricus terrestris inhabiting volcanic soils

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Andre [Departamento de Biologia, Universidade dos Acores, R. Mae de Deus, APT 1422, PT-9501-855 Ponta Delgada (Portugal)]. E-mail: aamaral@notes.uac.pt; Soto, Manu [Biologia Zelularra eta Histologia Laborategia, Zoologia eta Biologia Zelularra Saila, Zientzi Fakultatea, Euskal Herriko Unibertsitatea, 644 PK E-48080 Bilbao (Spain); Cunha, Regina [Departamento de Biologia, Universidade dos Acores, R. Mae de Deus, APT 1422, PT-9501-855 Ponta Delgada (Portugal); Marigomez, Ionan [Biologia Zelularra eta Histologia Laborategia, Zoologia eta Biologia Zelularra Saila, Zientzi Fakultatea, Euskal Herriko Unibertsitatea, 644 PK E-48080 Bilbao (Spain); Rodrigues, Armindo [Departamento de Biologia, Universidade dos Acores, R. Mae de Deus, APT 1422, PT-9501-855 Ponta Delgada (Portugal)

    2006-07-15

    Whether the radial thickness (RT) of the chloragogenous tissue and intestinal epithelium of earthworms (Lumbricus terrestris) reflects the bioavailability of metals in soils was investigated in two areas, one with active volcanism (Furnas) and another with no volcanic activity since 3 million years ago (Santa Maria), in the Azores. Metal contents in soil samples and earthworms from the two areas were analyzed. Autometallography and measurements of the RT were performed in the chloragogenous tissue and intestinal epithelium. Earthworms from the active volcanic area demonstrated lower RT of chloragogenous tissue and intestinal epithelium as well as higher levels of bioavailable metals, especially Zn and Cd. Comparison of bioavailable metal contents between both areas suggests a higher risk for uptake of potentially toxic metals in the active volcanic area than in the non-active volcanic area, which is reflected by the lower RT of the chloragogenous tissue and intestinal epithelium in the former. - In earthworms, differences in the chloragogenous tissue morphometry may be related to the bioavailability of metals in soils.

  15. Direct detection of a single evoked action potential with MRS in Lumbricus terrestris.

    Science.gov (United States)

    Poplawsky, Alexander J; Dingledine, Raymond; Hu, Xiaoping P

    2012-01-01

    Functional MRI (fMRI) measures neural activity indirectly by detecting the signal change associated with the hemodynamic response following brain activation. In order to alleviate the temporal and spatial specificity problems associated with fMRI, a number of attempts have been made to detect neural magnetic fields (NMFs) with MRI directly, but have thus far provided conflicting results. In this study, we used MR to detect axonal NMFs in the median giant fiber of the earthworm, Lumbricus terrestris, by examining the free induction decay (FID) with a sampling interval of 0.32 ms. The earthworm nerve cords were isolated from the vasculature and stimulated at the threshold of action potential generation. FIDs were acquired shortly after the stimulation, and simultaneous field potential recordings identified the presence or absence of single evoked action potentials. FIDs acquired when the stimulus did not evoke an action potential were summed as background. The phase of the background-subtracted FID exhibited a systematic change, with a peak phase difference of (-1.2 ± 0.3) × 10(-5) radians occurring at a time corresponding to the timing of the action potential. In addition, we calculated the possible changes in the FID magnitude and phase caused by a simulated action potential using a volume conductor model. The measured phase difference matched the theoretical prediction well in both amplitude and temporal characteristics. This study provides the first evidence for the direct detection of a magnetic field from an evoked action potential using MR. Copyright © 2011 John Wiley & Sons, Ltd.

  16. Impact of the earthworm Lumbricus terrestris (L.) on As, Cu, Pb and Zn mobility and speciation in contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Sizmur, Tom, E-mail: t.p.sizmur@reading.ac.uk [Soil Research Centre, Department of Geography and Environmental Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom); Palumbo-Roe, Barbara; Watts, Michael J. [British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham NG12 5GG (United Kingdom); Hodson, Mark E. [Soil Research Centre, Department of Geography and Environmental Science, School of Human and Environmental Sciences, University of Reading, Whiteknights, Reading RG6 6DW (United Kingdom)

    2011-03-15

    To assess the risks that contaminated soils pose to the environment properly a greater understanding of how soil biota influence the mobility of metal(loid)s in soils is required. Lumbricus terrestris L. were incubated in three soils contaminated with As, Cu, Pb and Zn. The concentration and speciation of metal(loid)s in pore waters and the mobility and partitioning in casts were compared with earthworm-free soil. Generally the concentrations of water extractable metal(loid)s in earthworm casts were greater than in earthworm-free soil. The impact of the earthworms on concentration and speciation in pore waters was soil and metal specific and could be explained either by earthworm induced changes in soil pH or soluble organic carbon. The mobilisation of metal(loid)s in the environment by earthworm activity may allow for leaching or uptake into biota. - Research highlights: > Earthworms increase the mobility and availability of metals and metalloids in soils. > We incubated L. terrestris in three soils contaminated with As, Cu, Pb and Zn. > Earthworms increased the mobility of As, Cu, Pb and Zn in their casts. > The mechanisms for this could be explained by changes in pH or organic carbon. - Lumbricus terrestris change the partitioning of metal(loid)s between soil constituents and increase the mobility of metal(loid)s in casts and pore water.

  17. Impact of the earthworm Lumbricus terrestris (L.) on As, Cu, Pb and Zn mobility and speciation in contaminated soils

    International Nuclear Information System (INIS)

    Sizmur, Tom; Palumbo-Roe, Barbara; Watts, Michael J.; Hodson, Mark E.

    2011-01-01

    To assess the risks that contaminated soils pose to the environment properly a greater understanding of how soil biota influence the mobility of metal(loid)s in soils is required. Lumbricus terrestris L. were incubated in three soils contaminated with As, Cu, Pb and Zn. The concentration and speciation of metal(loid)s in pore waters and the mobility and partitioning in casts were compared with earthworm-free soil. Generally the concentrations of water extractable metal(loid)s in earthworm casts were greater than in earthworm-free soil. The impact of the earthworms on concentration and speciation in pore waters was soil and metal specific and could be explained either by earthworm induced changes in soil pH or soluble organic carbon. The mobilisation of metal(loid)s in the environment by earthworm activity may allow for leaching or uptake into biota. - Research highlights: → Earthworms increase the mobility and availability of metals and metalloids in soils. → We incubated L. terrestris in three soils contaminated with As, Cu, Pb and Zn. → Earthworms increased the mobility of As, Cu, Pb and Zn in their casts. → The mechanisms for this could be explained by changes in pH or organic carbon. - Lumbricus terrestris change the partitioning of metal(loid)s between soil constituents and increase the mobility of metal(loid)s in casts and pore water.

  18. Effect of temperature on heavy metal toxicity to earthworm Lumbricus terrestris (Annelida: Oligochaeta).

    Science.gov (United States)

    Khan, M A Q; Ahmed, S A; Salazar, A; Gurumendi, J; Khan, A; Vargas, M; von Catalin, B

    2007-10-01

    Earthworms (Lumbricus terrestris) acclimated at 2 degrees C above their habitat temperature (10-12 degrees C) showed about 5% increase in basal rate of oxygen consumption, which increased to about 38% in 14-16 degrees C- and 40% in 16-18 degrees C-, but decreased by 84% in 20-22 degrees C-acclimated worms. Temperature also increased the blood hemoglobin (Hb) concentration, which decreased slightly in 20-22 degrees C-acclimated worms. The worms acclimated at 20-22 degrees C showed their blood to be hypovolemic than that of 10-12 degrees C worms indicating dehydration. Pre-exposure of 10-14 degrees C-acclimated worms to sublethal concentrations of zinc, copper, and lead did not significantly affect the rate of respiration. However, at higher temperatures all these metals inhibited oxygen consumption; zinc, lead, and cadmium by approximately 11% and copper by approximately 18% of that at 14-16 degrees C. At 20-22 degrees C, the respiration was further inhibited, 36% by copper, 18% by cadmium, and approximately 10% by lead and zinc. Copper, lead, and zinc decreased the temperature-enhanced increase in blood Hb concentration at all temperatures. In 20-22 degrees C-acclimated worms heavy metal exposure slightly lowered the oxygen affinity of Hb as well as caused shifts in carbon monoxide difference spectra. The acute toxicity of these metals was not affected by a 2 degrees C rise in acclimation temperature but increased by 17% (lead), 33% (copper), and 5% (zinc) in 14-16 degrees C- and by 40% (lead), 149% (copper), and 132% (zinc) in 20-22 degrees C-acclimated worms. The increase in toxicity of metals caused by high temperatures may be due to limiting the scope of aerobic metabolism (oxygen extraction, transport, and utilization) via quantitative and qualitative effects on Hb. This terrestrial species appears to be tolerant of slight increases in habitat temperature, such as that expected with current global climate change. 2007 Wiley Periodicals, Inc.

  19. DNA barcoding reveals cryptic diversity in Lumbricus terrestris L., 1758 (Clitellata: resurrection of L. herculeus (Savigny, 1826.

    Directory of Open Access Journals (Sweden)

    Samuel W James

    Full Text Available The widely studied and invasive earthworm, Lumbricus terrestris L., 1758 has been the subject of nomenclatural debate for many years. However these disputes were not based on suspicions of heterogeneity, but rather on the descriptions and nomenclatural acts associated with the species name. Large numbers of DNA barcode sequences of the cytochrome oxidase I obtained for nominal L. terrestris and six congeneric species reveal that there are two distinct lineages within nominal L. terrestris. One of those lineages contains the Swedish population from which the name-bearing specimen of L. terrestris was obtained. The other contains the population from which the syntype series of Enterion herculeum Savigny, 1826 was collected. In both cases modern and old representatives yielded barcode sequences allowing us to clearly establish that these are two distinct species, as different from one another as any other pair of congeners in our data set. The two are morphologically indistinguishable, except by overlapping size-related characters. We have designated a new neotype for L. terrestris. The newly designated neotype and a syntype of L. herculeus yielded DNA adequate for sequencing part of the cytochrome oxidase I gene (COI. The sequence data make possible the objective determination of the identities of earthworms morphologically identical to L. terrestris and L. herculeus, regardless of body size and segment number. Past work on nominal L. terrestris could have been on either or both species, although L. herculeus has yet to be found outside of Europe.

  20. DNA barcoding reveals cryptic diversity in Lumbricus terrestris L., 1758 (Clitellata): resurrection of L. herculeus (Savigny, 1826).

    Science.gov (United States)

    James, Samuel W; Porco, David; Decaëns, Thibaud; Richard, Benoit; Rougerie, Rodolphe; Erséus, Christer

    2010-12-29

    The widely studied and invasive earthworm, Lumbricus terrestris L., 1758 has been the subject of nomenclatural debate for many years. However these disputes were not based on suspicions of heterogeneity, but rather on the descriptions and nomenclatural acts associated with the species name. Large numbers of DNA barcode sequences of the cytochrome oxidase I obtained for nominal L. terrestris and six congeneric species reveal that there are two distinct lineages within nominal L. terrestris. One of those lineages contains the Swedish population from which the name-bearing specimen of L. terrestris was obtained. The other contains the population from which the syntype series of Enterion herculeum Savigny, 1826 was collected. In both cases modern and old representatives yielded barcode sequences allowing us to clearly establish that these are two distinct species, as different from one another as any other pair of congeners in our data set. The two are morphologically indistinguishable, except by overlapping size-related characters. We have designated a new neotype for L. terrestris. The newly designated neotype and a syntype of L. herculeus yielded DNA adequate for sequencing part of the cytochrome oxidase I gene (COI). The sequence data make possible the objective determination of the identities of earthworms morphologically identical to L. terrestris and L. herculeus, regardless of body size and segment number. Past work on nominal L. terrestris could have been on either or both species, although L. herculeus has yet to be found outside of Europe.

  1. Effects of tree leaf litter, deer fecal pellets, and soil properties on growth of an introduced earthworm (Lumbricus terrestris): Implications for invasion dynamics

    Science.gov (United States)

    Kassidy N. Yatso; Erik A. Lilleskov

    2016-01-01

    Invasive earthworm communities are expanding into previously earthworm-free forests of North America, producing profound ecosystem changes. Lumbricus terrestris is an invasive anecic earthworm that consumes a large portion of the detritus on the soil surface, eliminating forest floor organic horizons and reducing soil organic matter. Two mesocosm...

  2. Impact of earthworm Lumbricus terrestris living sites on the greenhouse gas balance of no-till arable soil

    Science.gov (United States)

    Nieminen, M.; Hurme, T.; Mikola, J.; Regina, K.; Nuutinen, V.

    2015-09-01

    We studied the effect of the deep-burrowing earthworm Lumbricus terrestris on the greenhouse gas (GHG) fluxes and global warming potential (GWP) of arable no-till soil using both field measurements and a controlled 15-week laboratory experiment. In the field, the emissions of nitrous oxide (N2O) and carbon dioxide (CO2) were on average 43 and 32 % higher in areas occupied by L. terrestris (the presence judged by the surface midden) than in adjacent, unoccupied areas (with no midden). The fluxes of methane (CH4) were variable and had no consistent difference between the midden and non-midden areas. Removing the midden did not affect soil N2O and CO2 emissions. The laboratory results were consistent with the field observations in that the emissions of N2O and CO2 were on average 27 and 13 % higher in mesocosms with than without L. terrestris. Higher emissions of N2O were most likely due to the higher content of mineral nitrogen and soil moisture under the middens, whereas L. terrestris respiration fully explained the observed increase in CO2 emissions in the laboratory. In the field, the significantly elevated macrofaunal densities in the vicinity of middens likely contributed to the higher emissions from areas occupied by L. terrestris. The activity of L. terrestris increased the GWP of field and laboratory soil by 50 and 18 %, but only 6 and 2 % of this increase was due to the enhanced N2O emission. Our results suggest that high N2O emissions commonly observed in no-till soils can partly be explained by the abundance of L. terrestris under no-till management and that L. terrestris can markedly regulate the climatic effects of different cultivation practises.

  3. Metallothionein Induction in the Coelomic Fluid of the Earthworm Lumbricus terrestris following Heavy Metal Exposure: A Short Report

    Directory of Open Access Journals (Sweden)

    A. Calisi

    2014-01-01

    Full Text Available Earthworms are useful bioindicator organisms for soil biomonitoring. Recently the use of pollution biomarkers in earthworms has been increasingly investigated for soil monitoring and assessment. Earthworm coelomic fluid is particularly interesting from a toxicological perspective, because it is responsible for pollutant disposition and tissue distribution to the whole organism. The aim of the present work was to study the effect of heavy metal exposure on metallothionein (Mt induction in the coelomic fluid of Lumbricus terrestris in view of future use as sensitive biomarker suitable for application to metal polluted soil monitoring and assessment. L. terrestris coelomic fluid showed a detectable Mt concentration of about 4.0±0.6 μg/mL (mean ± SEM, n=10 in basal physiological condition. When the animals were exposed to CuSO4 or CdCl2 or to a mixture of the two metals in OECD soils for 72 h, the Mt specific concentration significantly (P<0.001 increased. The Mt response in the coelomic fluid perfectly reflected the commonly used Mt response in the whole organism when the two responses were compared on the same specimens. These findings indicate the suitability of Mt determination in L. terrestris coelomic fluid as a sensitive biomarker for application to metal polluted soil monitoring and assessment.

  4. Comparative toxicity in earthworms Eisenia fetida and Lumbricus terrestris exposed to cadmium nitrate using artificial soil and filter paper protocols

    Energy Technology Data Exchange (ETDEWEB)

    Fitzpatrick, L.C.; Goven, A.J. [Univ. of North Texas, Denton, TX (United States); Muratti-Ortiz, J.F. [City of Denton Water/Wastewater Laboratory, TX (United States); Venables, B.J. [TRAC Laboratories Inc., Denton, TX (United States)

    1996-07-01

    Earthworms are ideal soil organisms for use in terrestrial ecotoxicology. As such, several earthworm protocols have been developed for testing toxic potential of chemicals and contaminated soils. Of these, the 48-h filter paper contact (FP) and the 14-d artificial soil exposure (AS) protocols, using mortality (LC50) as the toxic endpoint and Eisenia fetida as the test species, have received the most attention, with the latter being adopted by both OECD and EEC in Europe and the Environmental Protection Agency (USEPA) in the United States. Although the FP technique, adopted by EEC, provides for inexpensive reproducible toxicity screening for chemicals (i.e. establishing relative toxicities), it has been criticized for lacking the ecotoxicological relevance of the AS protocol. Choice of earthworm species for laboratory testing also has been controversial. The manure worm, E. fetida, is criticized for not being sufficiently sensitive to chemicals or representative of {open_quotes}typical{close_quotes} earthworms. Lumbricus terrestris and Apporectodea caliginosa have been suggested as more sensitive and ecologically relevant earthworms by Dean-Ross and Martin, respectively. This paper compares the AS and FP protocols in assessing toxicity of cadminum to L. terrestris and E. fetida using LC50s and LC50s. 19 refs., 2 tabs.

  5. Histopathological and biochemical alterations of the earthworm (Lumbricus Terrestris) as biomarker of soil pollution along Porsuk River Basin (Turkey).

    Science.gov (United States)

    Kılıç, Gözde Aydoğan

    2011-05-01

    This study investigated biomarker responses of the earthworm Lumbricus terrestris in order to evaluate the soil pollution along Porsuk River Basin. Samples consisted of animals from six sites that are agricultural regions and a forested control. Histopathological and biochemical alterations were examined. Significant histopathological alterations were observed in animals from three of the sampling sites. There was an enlargement of epithelial cell lining, mucus cell hyperplasia and increase in mucus secretion. Circular and longitudinal muscles lost their structural integrity. Chloragogenous tissue was dilated and vocuolized. Necrosis was observed in the cells and tissues of some affected worms. A load of heavy metals in tissues of animals was determined. Heavy metals were found to be accumulated particularly in longitudinal muscles of animals. CAT activity was found to be increased in animals from three of the experimental sites. GST activity was also increased in five sites while it was stable in one site. The results have shown that animals from locations particularly that are close to urbanized and industrialized regions were seriously affected from the soil pollution around the basin. These results are reflecting the biological effects of soil pollution around Porsuk River Basin on the indicator organism L. terrestris and constitute an early warning of ecological change in relation to human health. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Tissue distribution, isozyme abundance and sensitivity to chlorpyrifos-oxon of carboxylesterases in the earthworm Lumbricus terrestris

    International Nuclear Information System (INIS)

    Sanchez-Hernandez, Juan C.; Wheelock, Craig E.

    2009-01-01

    A laboratory-based study was conducted to determine the basal carboxylesterase (CbE) activity in different tissues of the earthworm Lumbricus terrestris, and its sensitivity to the organophosphate (OP) pesticide chlorpyrifos-oxon (CPx). Carboxylesterase activity was found in the pharynx, crop, gizzard, anterior intestine, wall muscle and reproductive tissues of L. terrestris, and multiple tissue-specific isozymes were observed by native gel electrophoresis. Esterase activity and sensitivity to CPx inhibition varied on a tissue- and substrate-specific basis, suggesting isoforms-specific selectivity to OP-mediated inhibition. Three practical issues are recommended for the use of earthworm CbE activity as a biomarker of pesticide exposure: (i) CbE should be measured using several routine substrates, (ii) it should be determined in selected tissues instead of whole organism homogenate, and (iii) earthworm CbE activity should be used in conjuncture with other common biomarkers (e.g., ChE) within a multibiomarker approach to assess field exposure of OPs, and potentially other agrochemicals. - The measurement of carboxylesterase inhibition in earthworm is a sensitive and complementary biomarker of pesticide exposure

  7. Tissue distribution, isozyme abundance and sensitivity to chlorpyrifos-oxon of carboxylesterases in the earthworm Lumbricus terrestris

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Hernandez, Juan C. [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, Avda. Carlos III, 45071 Toledo (Spain)], E-mail: juancarlos.sanchez@uclm.es; Wheelock, Craig E. [Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE 171 77, Stockholm (Sweden)

    2009-01-15

    A laboratory-based study was conducted to determine the basal carboxylesterase (CbE) activity in different tissues of the earthworm Lumbricus terrestris, and its sensitivity to the organophosphate (OP) pesticide chlorpyrifos-oxon (CPx). Carboxylesterase activity was found in the pharynx, crop, gizzard, anterior intestine, wall muscle and reproductive tissues of L. terrestris, and multiple tissue-specific isozymes were observed by native gel electrophoresis. Esterase activity and sensitivity to CPx inhibition varied on a tissue- and substrate-specific basis, suggesting isoforms-specific selectivity to OP-mediated inhibition. Three practical issues are recommended for the use of earthworm CbE activity as a biomarker of pesticide exposure: (i) CbE should be measured using several routine substrates, (ii) it should be determined in selected tissues instead of whole organism homogenate, and (iii) earthworm CbE activity should be used in conjuncture with other common biomarkers (e.g., ChE) within a multibiomarker approach to assess field exposure of OPs, and potentially other agrochemicals. - The measurement of carboxylesterase inhibition in earthworm is a sensitive and complementary biomarker of pesticide exposure.

  8. Interactions of juvenile Lumbricus terrestris with adults and their burrow systems in a two-dimensional microcosm Interações de juvenis de Lumbricus terrestris com adultos e seus sistemas de galerias em um microcosmo bidimensional

    Directory of Open Access Journals (Sweden)

    Niki Grigoropoulou

    2009-08-01

    Full Text Available The objective of this work was to evaluate interactions of Lumbricus terrestris juveniles with adults and with inherited burrow systems. An experiment was set up using a two dimensional Evans' boxes microcosm. Adult L. terrestris were added to 16 boxes (one individual per box and kept in darkness at 17ºC along with eight unoccupied boxes for two months. The adult L. terrestris were removed from eight randomly selected boxes, and L. terrestris juveniles were added (one juvenile per box, composing three treatments with eight replicates: 1, with an adult in an inherited burrow (ABJ; 2, alone in an inherited burrow (BJ; and 3, alone in a previously uninhabited box (J. The proportion of juveniles occupying adult burrows observed was significantly different in treatments ABJ (48% and BJ (75%. The mean mass of juveniles at experimental termination differed significantly among treatments and was greater in treatment J (4.04±0.39 g in comparison to the BJ (3.09±0.93 g and ABJ treatments (2.13±0.64 g. Results suggest a negative influence of both the presence of an adult and its burrow system on juvenile growth. Intraspecific competition partially explained this, but further investigation is required to examine how an inherited environment (i.e. burrow could negatively affect the growth of juveniles.O objetivo deste trabalho foi avaliar as interações de juvenis de Lumbricus terrestris com indivíduos adultos e com sistemas de galerias herdados. O experimento foi realizado usando microcosmos bidimensionais de Evans como unidades experimentais. Adultos de L. terrestris foram colocados em 16 unidades experimentais (um indivíduo por unidade e mantidos no escuro a 17ºC juntamente com oito unidades experimentais inabitadas, por dois meses. Os adultos foram removidos de oito unidades selecionadas aleatoriamente e juvenis foram adicionados a todas as unidades experimentais (um indivíduo por unidade, em três tratamentos, com oito repetições: 1, com um

  9. Food-chain transfer of cadmium and zinc from contaminated Urtica dioica to Helix aspersa and Lumbricus terrestris.

    Science.gov (United States)

    Sinnett, Danielle E; Hodson, Mark E; Hutchings, Tony R

    2009-08-01

    The present study examines the potential of Urtica dioica as an ecologically relevant species for use in ecotoxicological testing. It is prevalent in degraded ecosystems and is a food source for invertebrates. Urtica dioica grown in hydroponic solutions containing from less than 0.003 to 5.7 mg Cd/L or from 0.02 to 41.9 mg Zn/L accumulated metals resulting in leaf tissue concentrations in the range of 0.10 to 24.9 mg Cd/kg or 22.5 to 2,772.0 mg Zn/kg. No toxicological effects were apparent except at the highest concentrations tested, suggesting that this species may be an important pathway for transfer of metals to primary plant consumers. Helix aspersa and Lumbricus terrestris were fed the Cd- and Zn-rich leaves of U. dioica for six and four weeks, respectively. Cadmium and Zn body load increased with increasing metal concentration in the leaves (p dioica and suggest that reasonably reproducible results can be obtained using these species for ecotoxicological testing.

  10. Inhibition, recovery and oxime-induced reactivation of muscle esterases following chlorpyrifos exposure in the earthworm Lumbricus terrestris

    International Nuclear Information System (INIS)

    Collange, B.; Wheelock, C.E.; Rault, M.; Mazzia, C.; Capowiez, Y.; Sanchez-Hernandez, J.C.

    2010-01-01

    Assessment of wildlife exposure to organophosphorus (OP) pesticides generally involves the measurement of cholinesterase (ChE) inhibition, and complementary biomarkers (or related endpoints) are rarely included. Herein, we investigated the time course inhibition and recovery of ChE and carboxylesterase (CE) activities in the earthworm Lumbricus terrestris exposed to chlorpyrifos, and the ability of oximes to reactivate the phosphorylated ChE activity. Results indicated that these esterase activities are a suitable multibiomarker scheme for monitoring OP exposure due to their high sensitivity to OP inhibition and slow recovery to full activity levels following pesticide exposure. Moreover, oximes reactivated the inhibited ChE activity of the earthworms exposed to 12 and 48 mg kg -1 chlorpyrifos during the first week following pesticide exposure. This methodology is useful for providing evidence for OP-mediated ChE inhibition in individuals with a short history of OP exposure (≤1 week); resulting a valuable approach for assessing multiple OP exposure episodes in the field. - Esterase inhibition combined with oxime reactivation methods is a suitable approach for monitoring organophosphate contamination

  11. Inhibition, recovery and oxime-induced reactivation of muscle esterases following chlorpyrifos exposure in the earthworm Lumbricus terrestris

    Energy Technology Data Exchange (ETDEWEB)

    Collange, B. [Universite d' Avignon et des Pays de Vaucluse, UMR 406 Abeilles et Environnement, Site AGROPARC, F-84914, Avignon Cede 09 (France); Wheelock, C.E. [Division of Physiological Chemistry II, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE 171 77, Stockholm (Sweden); Rault, M.; Mazzia, C. [Universite d' Avignon et des Pays de Vaucluse, UMR 406 Abeilles et Environnement, Site AGROPARC, F-84914, Avignon Cede 09 (France); Capowiez, Y. [INRA, Unite PSH, Site AGROPARC, F-84914 Avignon Cedex 09 (France); Sanchez-Hernandez, J.C., E-mail: juancarlos.sanchez@uclm.e [Laboratory of Ecotoxicology, Faculty of Environmental Science, University of Castilla-La Mancha, Avda. Carlos III s/n, 45071, Toledo (Spain)

    2010-06-15

    Assessment of wildlife exposure to organophosphorus (OP) pesticides generally involves the measurement of cholinesterase (ChE) inhibition, and complementary biomarkers (or related endpoints) are rarely included. Herein, we investigated the time course inhibition and recovery of ChE and carboxylesterase (CE) activities in the earthworm Lumbricus terrestris exposed to chlorpyrifos, and the ability of oximes to reactivate the phosphorylated ChE activity. Results indicated that these esterase activities are a suitable multibiomarker scheme for monitoring OP exposure due to their high sensitivity to OP inhibition and slow recovery to full activity levels following pesticide exposure. Moreover, oximes reactivated the inhibited ChE activity of the earthworms exposed to 12 and 48 mg kg{sup -1} chlorpyrifos during the first week following pesticide exposure. This methodology is useful for providing evidence for OP-mediated ChE inhibition in individuals with a short history of OP exposure (<=1 week); resulting a valuable approach for assessing multiple OP exposure episodes in the field. - Esterase inhibition combined with oxime reactivation methods is a suitable approach for monitoring organophosphate contamination

  12. Assessing ecotoxicity and uptake of metals and metalloids in relation to two different earthworm species (Eiseina hortensis and Lumbricus terrestris)

    International Nuclear Information System (INIS)

    Leveque, Thibaut; Capowiez, Yvan; Schreck, Eva; Mazzia, Christophe; Auffan, Mélanie; Foucault, Yann; Austruy, Annabelle; Dumat, Camille

    2013-01-01

    Due to diffuse atmospheric fallouts of process particles enriched by metals and metalloids, polluted soils concern large areas at the global scale. Useful tools to assess ecotoxicity induced by these polluted soils are therefore needed. Earthworms are currently used as biotest, however the influence of specie and earthworm behaviour, soil characteristics are poorly highlighted. Our aim was therefore to assess the toxicity of various polluted soils with process particles enriches by metals and metalloids (Pb, Cd, Cu, Zn, As and Sb) collected from a lead recycling facility on two earthworm species belonging to different ecological types and thus likely to have contrasted behavioural responses (Eiseina hortensis and Lumbricus terrestris). The combination of behavioural factors measurements (cast production and biomass) and physico-chemical parameters such as metal absorption, bioaccumulation by earthworms and their localization in invertebrate tissues provided a valuable indication of pollutant bioavailability and ecotoxicity. Soil characteristics influenced ecotoxicity and metal uptake by earthworms, as well as their soil bioturbation. -- Highlights: •Historically polluted soils collected from a lead recycling facility were studied. •Cast production is a sensitive parameter to assess ecotoxicity on earthworms. •Both soil parameters, like organic matter content and pH and earthworm specie influence metal uptake and ecotoxicity. -- Behavioural factors and inorganic pollutant uptake by earthworms provide a valuable indication of bioavailability and ecotoxicity

  13. An enriched stable isotope technique to estimate the availability of soil zinc to Lumbricus terrestris (L.) across a salinization gradient.

    Science.gov (United States)

    Rodgers, Derek W; Lev, Steven M; Snodgrass, Joel W; Ownby, David R; Prince, Lisa M; Casey, Ryan E

    2011-03-01

    An enriched stable isotope approach was developed to evaluate Zn bioavailability to Lumbricus terrestris. The decrease in (68)Zn/(66) Zn in organ tissues was used to assess the relative magnitude of the bioavailable soil Zn pool. This tool was then used to specifically evaluate bioavailability as a function of soil cation distribution. Storm-water pond soils were modified using two treatment regimens whereby H(2)O-extractable Zn was varied either by different ZnCl(2) amendments or by constant ZnCl(2) amendment followed by varying the soil cation distribution through salt amendments (NaCl or CaCl(2)). Earthworms previously equilibrated in (68) Zn-spiked soil were introduced to experimental soils, and after 2 d, removed for analysis of isotopic ratios in specific tissues. Despite a wide range of H(2)O-extractable Zn values produced by the salt treatments (0.007-24.3 mg/kg), a significant relationship between Zn turnover rate in earthworm tissues and H(2)O-extractable Zn in the salt-treated soils was not observed. Rather, considering both treatment regimens, turnover rate better correlated with Zn present in broader pools, such as that extracted by 6M HNO(3). The bioavailability of trace metals to earthworms may be poorly characterized by loosely bound fractions such as the pore water. Additionally, the turnover rate of (68)Zn in anterior organ tissues may be an effective tool to evaluate the relative magnitude of the bioavailable soil Zn pool. Copyright © 2010 SETAC.

  14. {sup 32}P-postlabeling determination of DNA adducts in the earthworm Lumbricus terrestris exposed to PAH-contaminated soils

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, P. [Laval Univ. Research Center, Quebec (Canada)]|[Ministere de l`Environnement et de la Faune du Quebec (Canada); El Adlouni, C.; Mukhopadhyay, M.J.; Nadeau, D.; Poirier, G.G. [Laval Univ. Research Center, Quebec (Canada); Viel, G. [CreaLab., Quebec (Canada)

    1995-05-01

    The importance of the search for reliable biomarkers of DNA damage in environmental health assessment is well recognized by the scientific community and regulatory agencies. Among the major biomarkers of DNA damage is the measurement of DNA adducts in target cells or tissues. Up to now, DNA adduct determinations have been directed mostly toward human exposure to toxic substances from the workplace and environment. Moreover, techniques for measuring DNA adducts, and in particular the {sup 32}P-postlabelling technique, presented also the possibility of determining DNA adduct levels in endogenous animal populations exposed to polluted environments as early warning monitors of ecotoxicity. Soil contamination is becoming a major environmental issue. Therefore, numerous contaminated sites must now be remediated to protect human health and to permit new uses of these sites as agricultural, residential, or industrial areas. Fulfillment of this task requires standardized and sensitive bioassays to carry out site evaluations and to establish scientifically defensible soil quality criteria. To that effect, the earthworm appears to be one of the best organisms for use in soil toxicity evaluation. Earthworms are probably the most relevant soil species, representing 60 to 80% of the total animal biomass in soil. Present soil bioassays focus mostly on plant species with end points like seed germination, root elongation, seedling growth and seedling emergence, and on acute toxicity evaluation (re: LC 50) on the earthworm Eisenia fetida. As yet, a standardized soil invertebrate test for teratogenic or mutagenic end points has not been developed. In this paper, we report the feasibility of DNA adduct determination by {sup 32}P-postlabelling in the earthworm Lumbricus terrestris as a way to detect the presence of genotoxic substances in soils. 20 refs., 1 fig., 1 tab.

  15. Lytic activities in coelomic fluid of Eisenia foetida and Lumbricus terrestris.

    Science.gov (United States)

    Tucková, L; Rejnek, J; Síma, P; Ondrejová, R

    1986-01-01

    Coelomic fluids of the two earthworm species E.foetida (E.F.) and L.terrestris (L.T.) have not only the ability to lyse various vertebrate erythrocytes but also to digest vertebrate serum proteins. Both activities are carried by different molecules since hemolysis but not proteolysis was inhibited by simple sugars. In contrary, proteolysis was blocked by PMSF which did not influence hemolysis. Coelomic fluids of E.F. digest effectively vertebrate serum proteins (PIgG, HSA) but not the proteins of L.T. coelomic fluids. The proteolytic activity was detected in approximately 40 000 mol. wt. fraction. After digestion proteolytic fragments were analyzed by immunoelectrophoresis, SDS-PAGE and TCA precipitation. Two of the fragments reacting with PIgG antisera remained intact even after 120 h digestion.

  16. Effects of chronic exposure to clothianidin on the earthworm Lumbricus terrestris.

    Science.gov (United States)

    Basley, Kate; Goulson, Dave

    2017-01-01

    Although neonicotinoids are targeted at insects, their predominant use as a seed dressing and their long persistence in soils mean that non-target soil organisms such as earthworms are likely to be chronically exposed to them. Chronic exposure may pose risks that are not evaluated in most toxicity tests. We experimentally tested the effect of field-realistic concentrations of a commonly used neonicotinoid, clothianidin, on mortality, weight gain, and food consumption to assess the impacts of chronic exposure over four months on fitness of L. terrestris individuals. We undertook three separate experiments, each with different exposure routes: treated soil only (experiment A), treated food and soil combined (experiment B) and treated food only (experiment C). Mortality was negatively affected by exposure from treated soil only with greatest mortality observed in the groups exposed to the two highest concentrations (20 ppb and 100 ppb), but no clear effect on mortality was found in the other two experiments. When clothianidin was present in the food, an anti-feedant effect was present in months one and two which subsequently disappeared; if this occurs in the field, it could result in reduced rates of decomposition of treated crop foliage. We found no significant effects of any treatment on worm body mass. We cannot rule out stronger adverse effects if worms come into close proximity to treated seeds, or if other aspects of fitness were examined. Overall, our data suggest that field-realistic exposure to clothianidin has a significant but temporary effect on food consumption and can have weak but significant impacts on mortality of L. terrestris.

  17. Effects of chronic exposure to clothianidin on the earthworm Lumbricus terrestris

    Directory of Open Access Journals (Sweden)

    Kate Basley

    2017-04-01

    Full Text Available Although neonicotinoids are targeted at insects, their predominant use as a seed dressing and their long persistence in soils mean that non-target soil organisms such as earthworms are likely to be chronically exposed to them. Chronic exposure may pose risks that are not evaluated in most toxicity tests. We experimentally tested the effect of field-realistic concentrations of a commonly used neonicotinoid, clothianidin, on mortality, weight gain, and food consumption to assess the impacts of chronic exposure over four months on fitness of L. terrestris individuals. We undertook three separate experiments, each with different exposure routes: treated soil only (experiment A, treated food and soil combined (experiment B and treated food only (experiment C. Mortality was negatively affected by exposure from treated soil only with greatest mortality observed in the groups exposed to the two highest concentrations (20 ppb and 100 ppb, but no clear effect on mortality was found in the other two experiments. When clothianidin was present in the food, an anti-feedant effect was present in months one and two which subsequently disappeared; if this occurs in the field, it could result in reduced rates of decomposition of treated crop foliage. We found no significant effects of any treatment on worm body mass. We cannot rule out stronger adverse effects if worms come into close proximity to treated seeds, or if other aspects of fitness were examined. Overall, our data suggest that field-realistic exposure to clothianidin has a significant but temporary effect on food consumption and can have weak but significant impacts on mortality of L. terrestris.

  18. Combining µXANES and µXRD mapping to analyse the heterogeneity in calcium carbonate granules excreted by the earthworm Lumbricus terrestris

    International Nuclear Information System (INIS)

    Brinza, Loredana; Schofield, Paul F.; Hodson, Mark E.; Weller, Sophie; Ignatyev, Konstantin; Geraki, Kalotina; Quinn, Paul D.; Mosselmans, J. Frederick W.

    2014-01-01

    A new experimental set-up enabling microfocus fluorescence XANES mapping and microfocus XRD mapping on the same sample at beamline I18 at Diamond Light Source is described. To demonstrate this set-up the heterogeneous mineralogy in calcium carbonate granules excreted by the earthworm Lumbricus terrestris has been analysed. Data analysis methods have been developed which enable µXRD and µXANES two-dimensional maps to be compared. The use of fluorescence full spectral micro-X-ray absorption near-edge structure (µXANES) mapping is becoming more widespread in the hard energy regime. This experimental method using the Ca K-edge combined with micro-X-ray diffraction (µXRD) mapping of the same sample has been enabled on beamline I18 at Diamond Light Source. This combined approach has been used to probe both long- and short-range order in calcium carbonate granules produced by the earthworm Lumbricus terrestris. In granules produced by earthworms cultured in a control artificial soil, calcite and vaterite are observed in the granules. However, granules produced by earthworms cultivated in the same artificial soil amended with 500 p.p.m. Mg also contain an aragonite. The two techniques, µXRD and µXANES, probe different sample volumes but there is good agreement in the phase maps produced

  19. Combining µXANES and µXRD mapping to analyse the heterogeneity in calcium carbonate granules excreted by the earthworm Lumbricus terrestris

    Energy Technology Data Exchange (ETDEWEB)

    Brinza, Loredana [Diamond Light Source, Harwell Campus, Didcot, Oxon OX11 0DE (United Kingdom); Schofield, Paul F. [Natural History Museum, Cromwell Road, London SW7 5BD (United Kingdom); Hodson, Mark E. [University of York, York YO10 5DD (United Kingdom); Weller, Sophie [University of Oxford, South Parks Road, Oxford OX1 3QR (United Kingdom); Ignatyev, Konstantin; Geraki, Kalotina; Quinn, Paul D.; Mosselmans, J. Frederick W., E-mail: fred.mosselmans@diamond.ac.uk [Diamond Light Source, Harwell Campus, Didcot, Oxon OX11 0DE (United Kingdom)

    2014-01-01

    A new experimental set-up enabling microfocus fluorescence XANES mapping and microfocus XRD mapping on the same sample at beamline I18 at Diamond Light Source is described. To demonstrate this set-up the heterogeneous mineralogy in calcium carbonate granules excreted by the earthworm Lumbricus terrestris has been analysed. Data analysis methods have been developed which enable µXRD and µXANES two-dimensional maps to be compared. The use of fluorescence full spectral micro-X-ray absorption near-edge structure (µXANES) mapping is becoming more widespread in the hard energy regime. This experimental method using the Ca K-edge combined with micro-X-ray diffraction (µXRD) mapping of the same sample has been enabled on beamline I18 at Diamond Light Source. This combined approach has been used to probe both long- and short-range order in calcium carbonate granules produced by the earthworm Lumbricus terrestris. In granules produced by earthworms cultured in a control artificial soil, calcite and vaterite are observed in the granules. However, granules produced by earthworms cultivated in the same artificial soil amended with 500 p.p.m. Mg also contain an aragonite. The two techniques, µXRD and µXANES, probe different sample volumes but there is good agreement in the phase maps produced.

  20. Dew-worms in white nights: High latitude light constrains earthworm (Lumbricus terrestris) behaviour at the soil surface

    Science.gov (United States)

    Soil is an effective barrier to light penetration that limits the direct influence of light on belowground organisms. Variation in aboveground light conditions, however, is important to soil-dwelling animals that are periodically active on the soil surface. A prime example is the earthworm Lumbricus...

  1. Combining µXANES and µXRD mapping to analyse the heterogeneity in calcium carbonate granules excreted by the earthworm Lumbricus terrestris.

    Science.gov (United States)

    Brinza, Loredana; Schofield, Paul F; Hodson, Mark E; Weller, Sophie; Ignatyev, Konstantin; Geraki, Kalotina; Quinn, Paul D; Mosselmans, J Frederick W

    2014-01-01

    The use of fluorescence full spectral micro-X-ray absorption near-edge structure (µXANES) mapping is becoming more widespread in the hard energy regime. This experimental method using the Ca K-edge combined with micro-X-ray diffraction (µXRD) mapping of the same sample has been enabled on beamline I18 at Diamond Light Source. This combined approach has been used to probe both long- and short-range order in calcium carbonate granules produced by the earthworm Lumbricus terrestris. In granules produced by earthworms cultured in a control artificial soil, calcite and vaterite are observed in the granules. However, granules produced by earthworms cultivated in the same artificial soil amended with 500 p.p.m. Mg also contain an aragonite. The two techniques, µXRD and µXANES, probe different sample volumes but there is good agreement in the phase maps produced.

  2. Distribution of heavy metals in Lumbricus terrestris, Aporrectodea longa and A. rosea measured by atomic absorption and X-ray fluorescence spectrometry

    International Nuclear Information System (INIS)

    Andersen, C.; Laursen, J.

    1982-01-01

    Distribution of Ca, Pb, Cd, Zn, Fe and Mn has been investigated in the earthworm species Lumbricus terrestris, Aporectodea longa and A. rosea by atomic absorption and X-ray fluorescence spectrometry measurements. The material of L. terrestris originated from the garden of the Royal Veterinary and Agricultural University in central Copenhagen. Material of the other two species was sampled in sewage sludge treated plots. It was found that lead and cadmium are accumulated in the gut wall and from here transferred to waste nodules (brown bodies). In L. terrestris more lead was transferred to waste nodules than cadmium. Also large amounts of zinc were accumulated in the gut wall. Analyses of L. terrestris calciferous glands showed that these take part in regulation and excretion of a number of heavy metals. Lead and cadmium content was low in the ventral nerve chord and seminal vesicles. A. longa with poorly developed calciferous glands seems to rely more on waste nodule formation in the ultimate immobilization of lead. (author)

  3. Differences in p,p'-DDE bioaccumulation from compost and soil by the plants Cucurbita pepo and Cucurbita maxima and the earthworms Eisenia fetida and Lumbricus terrestris

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Richard [Program in Environmental Science and Department of Chemistry, Muhlenberg College, 2400 Chew Street, Allentown, PA 18104 (United States)]. E-mail: rp232604@muhlenberg.edu; Kelsey, Jason W. [Program in Environmental Science and Department of Chemistry, Muhlenberg College, 2400 Chew Street, Allentown, PA 18104 (United States)]. E-mail: kelsey@muhlenberg.edu; White, Jason C. [Department of Soil and Water, The Connecticut Agricultural Experiment Station, 123 Huntington Street, New Haven, CT 06504 (United States)]. E-mail: jason.white@po.state.ct.us

    2007-07-15

    Two plant species, Cucurbita pepo and Cucurbita maxima, and two earthworm species, Eisenia fetida and Lumbricus terrestris, were exposed to soil and compost with equivalent p,p'-DDE contamination. Pollutant bioconcentration was equal in plant roots in both media, but translocation was higher in C. pepo. Bioaccumulation by E. fetida was approximately 6- and 3-fold higher than that by L. terrestris in the soil and compost, respectively. For all species, p,p'-DDE uptake was significantly greater from soil than from compost; 7- to 8-fold higher for plant roots and 3- to 7-fold higher for worms. Abiotic desorption from soil was approximately twice that from the compost. When all the data are normalized for organic-carbon content of the media, the contaminant is more tightly bound by soil than compost. Although the risk associated with p,p'-DDE is higher in soil than compost, important mechanistic differences exist in contaminant binding to organic carbon in the two media. - Availability of p,p'-DDE to earthworms and plants was dramatically different in soil and compost.

  4. Differences in p,p'-DDE bioaccumulation from compost and soil by the plants Cucurbita pepo and Cucurbita maxima and the earthworms Eisenia fetida and Lumbricus terrestris.

    Science.gov (United States)

    Peters, Richard; Kelsey, Jason W; White, Jason C

    2007-07-01

    Two plant species, Cucurbita pepo and Cucurbita maxima, and two earthworm species, Eisenia fetida and Lumbricus terrestris, were exposed to soil and compost with equivalent p,p'-DDE contamination. Pollutant bioconcentration was equal in plant roots in both media, but translocation was higher in C. pepo. Bioaccumulation by E. fetida was approximately 6- and 3-fold higher than that by L. terrestris in the soil and compost, respectively. For all species, p,p'-DDE uptake was significantly greater from soil than from compost; 7- to 8-fold higher for plant roots and 3- to 7-fold higher for worms. Abiotic desorption from soil was approximately twice that from the compost. When all the data are normalized for organic-carbon content of the media, the contaminant is more tightly bound by soil than compost. Although the risk associated with p,p'-DDE is higher in soil than compost, important mechanistic differences exist in contaminant binding to organic carbon in the two media.

  5. Differences in p,p'-DDE bioaccumulation from compost and soil by the plants Cucurbita pepo and Cucurbita maxima and the earthworms Eisenia fetida and Lumbricus terrestris

    International Nuclear Information System (INIS)

    Peters, Richard; Kelsey, Jason W.; White, Jason C.

    2007-01-01

    Two plant species, Cucurbita pepo and Cucurbita maxima, and two earthworm species, Eisenia fetida and Lumbricus terrestris, were exposed to soil and compost with equivalent p,p'-DDE contamination. Pollutant bioconcentration was equal in plant roots in both media, but translocation was higher in C. pepo. Bioaccumulation by E. fetida was approximately 6- and 3-fold higher than that by L. terrestris in the soil and compost, respectively. For all species, p,p'-DDE uptake was significantly greater from soil than from compost; 7- to 8-fold higher for plant roots and 3- to 7-fold higher for worms. Abiotic desorption from soil was approximately twice that from the compost. When all the data are normalized for organic-carbon content of the media, the contaminant is more tightly bound by soil than compost. Although the risk associated with p,p'-DDE is higher in soil than compost, important mechanistic differences exist in contaminant binding to organic carbon in the two media. - Availability of p,p'-DDE to earthworms and plants was dramatically different in soil and compost

  6. Long-term efficiency of soil stabilization with apatite and Slovakite: the impact of two earthworm species (Lumbricus terrestris and Dendrobaena veneta) on lead bioaccessibility and soil functioning.

    Science.gov (United States)

    Tica, D; Udovic, M; Lestan, D

    2013-03-01

    Remediation soil is exposed to various environmental factors over time that can affect the final success of the operation. In the present study, we assessed Pb bioaccessibility and microbial activity in industrially polluted soil (Arnoldstein, Austria) stabilized with 5% (w/w) of Slovakite and 5% (w/w) of apatite soil after exposure to two earthworm species, Lumbricus terrestris and Dendrobaena veneta, used as model environmental biotic soil factors. Stabilization resulted in reduced Pb bioaccessibility, as assessed with one-step extraction tests and six-step sequential extraction, and improved soil functioning, mirrored in reduced β-glucosidase activity in soil. Both earthworm species increased Pb bioaccessibility, thus decreasing the initial stabilization efficacy and indicating the importance of considering the long-term fate of remediated soil. The earthworm species had different effects on soil enzyme activity, which can be attributed to species-specific microbial populations in earthworm gut acting on the ingested soil. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Mitigating N2O emissions from clover residues by 3,4-dimethylpyrazole phosphate (DMPP) without adverse effects on the earthworm Lumbricus terrestris

    DEFF Research Database (Denmark)

    Kong, Xianwang; Duan, YunFeng; Schramm, Andreas

    2017-01-01

    in a 28-d mesocosm experiment, where DMPP spraying prior to tillage was simulated. Above-ground parts of 15N-labelled clover residues were treated with DMPP and either placed at 10 cm depth to simulate ploughing (PL), or mixed with soil at 0–10 cm depth to simulate rotovation (RO). Earthworms (Lumbricus...... terrestris) were introduced to study their role in residue decomposition and N2O emissions. Fluxes and isotopic composition of N2O were determined with dynamic chambers using laser spectroscopy. A gradual increase in 15N-enrichment of N2O indicated that denitrification was the main source. DMPP reduced...... cumulative N2O emissions in PL from 241 to 146 mg N m−2; the reduction in RO was smaller, from 103 to 94 mg N m−2, and not significant, possibly due to higher oxygen and soil NO3− availability. After 28 d incubation, on average > 90% of the earthworms were recovered, and in vivo N2O production from L...

  8. Depuration and uptake kinetics of I, CS, MN, ZN and CD by the earthworm (lumbricus terrestris) in radiotracer-spiked litter

    International Nuclear Information System (INIS)

    Sheppard, S.C.; Evenden, W.G.; Cornwell, T.C.

    1997-01-01

    The relative depuration and uptake kinetics of contaminants should be known to interpret appropriately the use of organisms such as earthworms in environmental bioassays and monitoring. For example, 14-d earthworm bioassays should be interpreted with the knowledge that some contaminants will continue to accumulate in tissues for months. The radiotracers 125 I, 134 Cs, 54 Mn, 65 Zn, and 109 Cd were applied to deciduous litter and specimens of Lumbricus terrestris were exposed, either to litter alone or to litter on the top of soil columns. Depuration was monitored for 120 d and uptake, in a separate experiment, for 20 d. Both depuration and uptake were described using two-phase, first-order statistical models. Gut clearance had a mean half-time of 1.4 d. The mean half-time for physiological depuration decreased from I (210 d) > Cd (150 d) > Zn (69 d) > Mn (40 d) > Cs (24 d). Both the deputation and the uptake experiments were necessary to resolve even partially the multiphase processes. Earthworm/soil dry weight concentration ratios decreased from Cd > Zn > I ≥ Cs ≥ Mn. The very slow kinetics indicate that tissue concentrations will increase continuously for a long time, with important implications for subsequent food-chain transfers. (author)

  9. The Effect of Earthworm (Lumbricus terrestris L.) Population Density and Soil Water Content Interactions on Nitrous Oxide Emissions from Agricultural Soils

    International Nuclear Information System (INIS)

    Evers, A.K.; Gordon, A.M.; Thevathasan, N.V.; Demers, T.A.

    2010-01-01

    Earthworms may have an influence on the production of N 2 O, a greenhouse gas, as a result of the ideal environment contained in their gut and casts for denitrifier bacteria. The objective of this study was to determine the relationship between earthworm (Lumbricus terrestris L.) population density, soil water content and N 2 O emissions in a controlled greenhouse experiment based on population densities (90 to 270 individuals m-2) found at the Guelph Agroforestry Research Station (GARS) from 1997 to 1998. An experiment conducted at considerably higher than normal densities of earthworms revealed a significant relationship between earthworm density, soil water content and N 2 O emissions, with mean emissions increasing to 43.5 g ha-1day-1 at 30 earthworms 0.0333 m-2 at 35% soil water content. However, a second experiment, based on the density of earthworms at GARS, found no significant difference in N 2 O emissions (5.49 to 6.99 g ha-1day-1) aa a result of density and 31% soil water content

  10. 'Systems toxicology' approach identifies coordinated metabolic responses to copper in a terrestrial non-model invertebrate, the earthworm Lumbricus rubellus.

    Science.gov (United States)

    Bundy, Jacob G; Sidhu, Jasmin K; Rana, Faisal; Spurgeon, David J; Svendsen, Claus; Wren, Jodie F; Stürzenbaum, Stephen R; Morgan, A John; Kille, Peter

    2008-06-03

    New methods are needed for research into non-model organisms, to monitor the effects of toxic disruption at both the molecular and functional organism level. We exposed earthworms (Lumbricus rubellus Hoffmeister) to sub-lethal levels of copper (10-480 mg/kg soil) for 70 days as a real-world situation, and monitored both molecular (cDNA transcript microarrays and nuclear magnetic resonance-based metabolic profiling: metabolomics) and ecological/functional endpoints (reproduction rate and weight change, which have direct relevance to population-level impacts). Both of the molecular endpoints, metabolomics and transcriptomics, were highly sensitive, with clear copper-induced differences even at levels below those that caused a reduction in reproductive parameters. The microarray and metabolomic data provided evidence that the copper exposure led to a disruption of energy metabolism: transcripts of enzymes from oxidative phosphorylation were significantly over-represented, and increases in transcripts of carbohydrate metabolising enzymes (maltase-glucoamylase, mannosidase) had corresponding decreases in small-molecule metabolites (glucose, mannose). Treating both enzymes and metabolites as functional cohorts led to clear inferences about changes in energetic metabolism (carbohydrate use and oxidative phosphorylation), which would not have been possible by taking a 'biomarker' approach to data analysis. Multiple post-genomic techniques can be combined to provide mechanistic information about the toxic effects of chemical contaminants, even for non-model organisms with few additional mechanistic toxicological data. With 70-day no-observed-effect and lowest-observed-effect concentrations (NOEC and LOEC) of 10 and 40 mg kg-1 for metabolomic and microarray profiles, copper is shown to interfere with energy metabolism in an important soil organism at an ecologically and functionally relevant level.

  11. 'Systems toxicology' approach identifies coordinated metabolic responses to copper in a terrestrial non-model invertebrate, the earthworm Lumbricus rubellus

    Directory of Open Access Journals (Sweden)

    Stürzenbaum Stephen R

    2008-06-01

    Full Text Available Abstract Background New methods are needed for research into non-model organisms, to monitor the effects of toxic disruption at both the molecular and functional organism level. We exposed earthworms (Lumbricus rubellus Hoffmeister to sub-lethal levels of copper (10–480 mg/kg soil for 70 days as a real-world situation, and monitored both molecular (cDNA transcript microarrays and nuclear magnetic resonance-based metabolic profiling: metabolomics and ecological/functional endpoints (reproduction rate and weight change, which have direct relevance to population-level impacts. Results Both of the molecular endpoints, metabolomics and transcriptomics, were highly sensitive, with clear copper-induced differences even at levels below those that caused a reduction in reproductive parameters. The microarray and metabolomic data provided evidence that the copper exposure led to a disruption of energy metabolism: transcripts of enzymes from oxidative phosphorylation were significantly over-represented, and increases in transcripts of carbohydrate metabolising enzymes (maltase-glucoamylase, mannosidase had corresponding decreases in small-molecule metabolites (glucose, mannose. Treating both enzymes and metabolites as functional cohorts led to clear inferences about changes in energetic metabolism (carbohydrate use and oxidative phosphorylation, which would not have been possible by taking a 'biomarker' approach to data analysis. Conclusion Multiple post-genomic techniques can be combined to provide mechanistic information about the toxic effects of chemical contaminants, even for non-model organisms with few additional mechanistic toxicological data. With 70-day no-observed-effect and lowest-observed-effect concentrations (NOEC and LOEC of 10 and 40 mg kg-1 for metabolomic and microarray profiles, copper is shown to interfere with energy metabolism in an important soil organism at an ecologically and functionally relevant level.

  12. Incorporation of 13C labelled root-shoot residues in soil in the presence of Lumbricus terrestris: An isotopic and molecular approach

    Science.gov (United States)

    Vidal, Alix; Alexis, Marie; Nguyen Tu, Thanh Tu; Anquetil, Christelle; Vaury, Véronique; Derenne, Sylvie; Quenea, Katell

    2016-04-01

    Litter from plant biomass deposited on soil surface can either be mineralized; releasing CO2 to the atmosphere, or transferred into the soil as organic compounds. Both pathways depend on biotic factors such as litter characteristics and the of soil organism activity. During the last decades, many studies have focused on the origin of organic matter, with a particular attention to the fate of root and shoot litter. It is generally admitted that roots decompose at a slower rate than shoots, resulting in a higher carbon sequestration in soil for compounds originating from roots. Earthworms play a central role in litter decomposition and carbon cycling, ingesting both organic and mineral compounds which are mixed, complexed and dejected in the form of casts at the soil surface or along earthworm burrows. The simultaneous impact of earthworms and root-shoot on soil carbon cycling is still poorly understood. This study aimed at (1) defining the rate of incorporation of root and shoot litter with or without earthworms and (2) characterizing the molecular composition of soil organic matter upon litter decomposition, after one year of experimentation. A mesocosm experiment was set up to follow the incorporation of 13C labelled Ryegrass root and shoot litter in the soil, in the presence of anecic earthworms (Lumbricus terrestris). Soil samples were collected at 0-20 and 40-60 cm, as well as surface casts, at the beginning and after 1, 2, 4, 8, 24 and 54 weeks of experiment. Organic carbon content and δ13C values were determined for all the samples with Elemental Analysis - Isotope Ratio Mass Spectrometry. Lipid-free soil and cast samples after 54 weeks of incubation were analyzed with Pyrolysis-Gas Chromatography-Mass Spectrometry. Pyrolysis products were grouped into six classes: polysaccharides, lignin derived compounds, phenols, N-compounds, aliphatic compounds and sterols. Each pyrolysis product was quantified thanks to its peak area, relative to the total area of the

  13. Assessment of short and long-term effects of imidacloprid on the burrowing behaviour of two earthworm species (Aporrectodea caliginosa and Lumbricus terrestris) by using 2D and 3D post-exposure techniques.

    Science.gov (United States)

    Dittbrenner, Nils; Moser, Isabelle; Triebskorn, Rita; Capowiez, Yvan

    2011-09-01

    Adverse effects of agrochemicals on earthworms' burrowing behaviour can have crucial impacts on the entire ecosystem. In the present study, we have therefore assessed short- and long-term effects on burrowing behaviour in the earthworm species Aporrectodea caliginosa and Lumbricus terrestris after exposure to a range of imidacloprid concentrations (0.2-4 mg kg(-1) dry weight (DW)) for different exposure times (1, 7, 14 d). 2D-terraria were used for the examination of post-exposure short-term effects (24-96 h), while post-exposure long-term effects were assessed by means of X-ray burrow reconstruction in three dimensional soil cores (6 weeks). For the latter each core was incubated with two specimens of L. terrestris and four of A. calignosa. Short-term effects on the burrowing behaviour (2D) of A. caliginosa were already detected at the lowest test concentration (0.2 mg kg(-1) DW), whereas such effects in L. terrestris were not observed until exposure to concentrations 10 times higher (2 mg kg(-1) DW). For both species tested in the 2D-terraria, "total burrow length after 24 h" and "maximal burrow depth after 24 h" were the most sensitive endpoints. 3D reconstructions of the burrow systems made by both earthworm species in the repacked soil cores revealed a significant linear decrease in burrow volume with increasing imidacloprid concentration. Since many of the observed effects occurred at imidacloprid concentrations relevant to natural conditions and since reduced activities of earthworms in soils can have crucial impacts on the ecosystem level, our results are of environmental concern. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. The Nitrogen Excretory Metabolism of Lumbricus Terrestris

    Science.gov (United States)

    Teal, A. R.

    1977-01-01

    The use of the earthworm as a laboratory animal for studying the effect of starvation on nitrogen metabolism is discussed. Simple techniques and methods are presented allowing in vivo physiological responses to be compared with changes in the enzyme potential of gut tissue. (Author/MA)

  15. Polo a Tierra

    OpenAIRE

    Betancur, Ángela; Rojas, Juliana; Garcés, Daniela

    2017-01-01

    Polo a Tierra es un proyecto que busca reactivar el parque de bolsillo como lugar de encuentro de los ciudadanos a través de acciones Ecoartísticas. Estas acciones serán realizadas con los niños y sus núcleos familiares, para mejorar el aspecto del parque que actualmente se encuentra deterioro y fomentar la generación de vínculos con la comunidad para que este se mantenga activo como sitio de encuentro y como espacio de apropiación de prácticas ecológicas y culturales.

  16. Bocadillos de Mi Tierra Ltda.

    OpenAIRE

    2011-01-01

    Bocadillos de mi Tierra Ltda. es una empresa del sector alimenticio desarrollada con el fin de transformar los conocimientos en beneficios tales como la elaboración de bocadillo de distintos sabores mostrando nuevos estilos, diseños y presentaciones que ayude a ampliar el mercado a nivel nacional e internacional. La presente tesis da a conocer el plan de negocios de la empresa Bocadillos de mi Tierra Ltda. que tiene como objetivo la producción y comercialización de bocadillos a base de fruta...

  17. La Nueva Sociedad de la Tierra Plana

    OpenAIRE

    Bartlett, Albert A.

    2014-01-01

    Hubo un tiempo, hace mucho, en el que la gente pensaba que la Tierra era plana, pero ahora, durante algunos siglos, la gente ha creído que la Tierra es redonda... como una pelota. Pero hay problemas con una Tierra redonda, y por ello está emergiendo un nuevo y actual paradigma, que parece un regreso a la sabiduría de los antiguos.Una esfera es curva y por lo tanto es finita, lo que implica que hay límites, y en particular hay límites al crecimiento de cosas que consuman partes de la Tierra y ...

  18. La Memoria De Nuestra Tierra: Colorado

    Science.gov (United States)

    Baca, Judy

    2005-01-01

    La Memoria de Nuestra Tierra combines a meticulously hand-painted landscape with historic photographs in a seamless blend imprinted on the holographic-like surface of a metallic coated substrate. The mural for the Denver International Airport, entitled La Memoria de Nuestra Tierra is a breakthrough in digital murals, printed digitally on a…

  19. Construcciones a base de tierra

    Directory of Open Access Journals (Sweden)

    Alvarez Alonso, Marina

    1984-11-01

    oriented towards dissipating possible prejudices which exist with regard to earthen constructions.Trabajo realizado y basado en las nuevas posibilidades de las construcciones con tierra, una vez considerado su interés en épocas anteriores y las nuevas posibilidades que ofrece ante la crítica impuesta por la crisis de la energía. Se hacen consideraciones sobre las necesidades de vivienda previstas hasta el año 2000 y otros parámetros que vuelven a ser importantes al confrontarlos económicamente con los materiales industrializados, sistemas de construcción, soluciones orientadas a los países en vías de desarrollo, etc. Continúa el trabajo con las primeras vías de experimentación práctica desarrolladas por el equipo de trabajo de viviendas de bajo coste orientadas a la búsqueda y promoción de recursos locales y abundantes como el material tierra, vías de experimentación que comienzan con el conocimiento por el equipo de técnicas y materiales durante el curso realizado en Ciadueña (Soria. Se describen aspectos técnicos del material tierra desarrollados paralelamente a la experiencia práctica inicial y orientada a la elección idónea de los componentes, una vez confrontada la información bibliográfica relacionada con el tema. Entre las consideraciones técnicas se llega a una exposición más exhaustiva sobre: 1 Las técnicas existentes: ladrillos de adobe, tierra apisonada (tapial, etc. 2 Porcentajes idóneos de los componentes para la elección de los materiales preferibles en cada una de las técnicas anteriores. 3 Consideraciones de los aspectos físicos y mecánicos de la maquinaria existente y en experimentación, así como de las posibilidades respecto a su puesta en obra, costes comparativos, etc. 4 Estudio de las posibilidades para mejorar las características del material tierra mediante diferentes técnicas de estabilización (compactación y correcciones granulométricas, estabilizantes fisicoquímicos, betunes, productos

  20. Bloque de tierra comprimida como material constructivo

    Directory of Open Access Journals (Sweden)

    Óscar Javier Gutiérrez Junco

    2011-07-01

    Full Text Available La construcción con tierra es poco usada en la actualidad debido a la falta de difusión e investigación, y a que es relacionada con la pobreza; por ende, se desaprovechan muchas de sus ventajas, como la abundancia demateria prima, la localización, la disponibilidad, el reciclaje, la producción sin consumo de energía (calorífica, el bajo costo y la resistencia –con un adecuado estudio del material tierra, de la estructuración y del suelo de fundación–; otras de sus ventajas son el aislamiento térmico y acústico. Con el paso del tiempo se han mejorado las técnicas constructivas con tierra, realizando estabilizaciones e implementando el uso de maquinaria y herramienta mecánica para elaborar bloques de tierra comprimida, y así facilitar el trabajo y obtener mayor rendimiento. Este artículo presenta la tierra como material constructivo, las técnicas o sistemas constructivos, los bloques de tierra comprimida (BTC y algunos ensayos realizados a estos bloques.

  1. Glutathione transferase (GST) as a candidate molecular-based biomarker for soil toxin exposure in the earthworm Lumbricus rubellus

    Energy Technology Data Exchange (ETDEWEB)

    LaCourse, E. James, E-mail: james.la-course@liverpool.ac.u [Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA (United Kingdom); Hernandez-Viadel, Mariluz; Jefferies, James R. [Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA (United Kingdom); Svendsen, Claus; Spurgeon, David J. [Centre for Ecology and Hydrology, Huntingdon PE28 2LS (United Kingdom); Barrett, John [Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA (United Kingdom); John Morgan, A.; Kille, Peter [Biosciences, University of Cardiff, Cardiff CF10 3TL (United Kingdom); Brophy, Peter M. [Institute of Biological, Environmental, and Rural Sciences, Aberystwyth University, Aberystwyth SY23 3DA (United Kingdom)

    2009-08-15

    The earthworm Lumbricus rubellus (Hoffmeister, 1843) is a terrestrial pollution sentinel. Enzyme activity and transcription of phase II detoxification superfamily glutathione transferases (GST) is known to respond in earthworms after soil toxin exposure, suggesting GST as a candidate molecular-based pollution biomarker. This study combined sub-proteomics, bioinformatics and biochemical assay to characterise the L. rubellus GST complement as pre-requisite to initialise assessment of the applicability of GST as a biomarker. L. rubellus possesses a range of GSTs related to known classes, with evidence of tissue-specific synthesis. Two affinity-purified GSTs dominating GST protein synthesis (Sigma and Pi class) were cloned, expressed and characterised for enzyme activity with various substrates. Electrospray ionisation mass spectrometry (ESI-MS) and tandem mass spectrometry (MS/MS) following SDS-PAGE were superior in retaining subunit stability relative to two-dimensional gel electrophoresis (2-DE). This study provides greater understanding of Phase II detoxification GST superfamily status of an important environmental pollution sentinel organism. - This study currently provides the most comprehensive view of the Phase II detoxification enzyme superfamily of glutathione transferases within the important environmental pollution sentinel earthworm Lumbricus rubellus.

  2. Glutathione transferase (GST) as a candidate molecular-based biomarker for soil toxin exposure in the earthworm Lumbricus rubellus

    International Nuclear Information System (INIS)

    LaCourse, E. James; Hernandez-Viadel, Mariluz; Jefferies, James R.; Svendsen, Claus; Spurgeon, David J.; Barrett, John; John Morgan, A.; Kille, Peter; Brophy, Peter M.

    2009-01-01

    The earthworm Lumbricus rubellus (Hoffmeister, 1843) is a terrestrial pollution sentinel. Enzyme activity and transcription of phase II detoxification superfamily glutathione transferases (GST) is known to respond in earthworms after soil toxin exposure, suggesting GST as a candidate molecular-based pollution biomarker. This study combined sub-proteomics, bioinformatics and biochemical assay to characterise the L. rubellus GST complement as pre-requisite to initialise assessment of the applicability of GST as a biomarker. L. rubellus possesses a range of GSTs related to known classes, with evidence of tissue-specific synthesis. Two affinity-purified GSTs dominating GST protein synthesis (Sigma and Pi class) were cloned, expressed and characterised for enzyme activity with various substrates. Electrospray ionisation mass spectrometry (ESI-MS) and tandem mass spectrometry (MS/MS) following SDS-PAGE were superior in retaining subunit stability relative to two-dimensional gel electrophoresis (2-DE). This study provides greater understanding of Phase II detoxification GST superfamily status of an important environmental pollution sentinel organism. - This study currently provides the most comprehensive view of the Phase II detoxification enzyme superfamily of glutathione transferases within the important environmental pollution sentinel earthworm Lumbricus rubellus.

  3. Ecologia de las lombrices de tierra

    Science.gov (United States)

    Grizelle Gonzalez

    2014-01-01

    De los organismos de suelo, las lombrices de tierra son las mas conocidas y a menudo son consideradas las mas importantes por su influencia en el funcionamiento de ecosistemas de suelo (Hendriz y Bohlen, 2002). Tienen un efecto significativo en la estructura del suelo, el ciclo de nutrimentos y ls productividad de las cosechas. En terminos de biomasa, generalmente...

  4. Comparative transcriptomic responses to chronic cadmium, fluoranthene, and atrazine exposure in Lumbricus rubellus

    NARCIS (Netherlands)

    Svendsen, C.; Owen, J.; Kille, P.; Wren, J.; Jonker, M.J.; Headley, B.A.; Morgan, A.J.; Blaxter, M.; Stürzenbaum, S.R.; Hankard, P.K.; Lister, L.J.; Spurgeon, D.J.

    2008-01-01

    Transcriptional responses of a soil-dwelling organism (the earthworm Lumbricus rubellus) to three chemicals, cadmium (Cd), fluoranthene (FA), and atrazine (AZ), were measured following chronic exposure, with the aim of identifying the nature of any shared transcriptional response. Principal

  5. Exploraciones Micológicas en Tierra del Fuego Mycological explorations in Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    Irma J. Gamundí

    2007-07-01

    Full Text Available Se narran las expediciones marítimas y terrestres en Tierra del Fuego durante los siglos XIX y XX, desde el punto de vista de la exploración micológica cuyos resultados han sido vertidos en publicaciones, destacando las expediciones argentinas. Contiene mapas con las principales expediciones argentinas. Se hace una evaluación de la diversidad fúngica de acuerdo con los datos previamente analizados, comparando los registros de colección en ambos períodos que indican una duplicación del número total de taxones de 647 especies descriptas en el siglo XIX hasta 1269 en el siglo XX. Simultáneamente se observa una disminución del 50,4 % al 19.7 % en el número de especies nuevas publicadas. Se agrega una lista de coleccionistas y otra del estado de conservación ex situ de especies seleccionadas. Se hace un breve comentario sobre la conservación de hábitats colonizados por hongos que están perturbados por la explotación no sustentable de los recursos naturales.A narration of the leading maritime and terrestrial expeditions in Fuegia during the XIX and XX centuries is approached from the point of view of the mycological exploration and published results on the mycobiota, emphazising the Argentine expeditions. Maps with the itinerary of main Argentine expeditions is given. An evaluation of the fungal diversity according to the previous review is presented, comparing the fungal records during both periods that shows duplication of the total number of taxa from 647 species described in XIX century to 1269 in the XX century. Simultaneously there is a decrease from 50.4 % to 19.7 % in the number of new species published. A list of collectors and a table with the state of ex-situ conservation of selected species is presented. A brief comment is given on conservation of habitats supporting fungal population that are disturbed by unsustainable exploitation of natural resources.

  6. Miniature excitatory synaptic ion currents in the earthworm Lumbricus terrestris body wall muscles

    Czech Academy of Sciences Publication Activity Database

    Volkov, E. M.; Nurullin, L. F.; Nikolsky, E.; Vyskočil, František

    2007-01-01

    Roč. 56, č. 5 (2007), s. 655-658 ISSN 0862-8408 R&D Projects: GA AV ČR(CZ) IAA5011411 Grant - others:RFBR(RU) 06-04-48458; Nsh(RU) 4444.2006.4 Institutional research plan: CEZ:AV0Z50110509 Keywords : ion currents * muscle cells * acetylcholine receptor Subject RIV: ED - Physiology Impact factor: 1.505, year: 2007

  7. Tierra Caliente, Michoacán

    Directory of Open Access Journals (Sweden)

    C. I. Villa

    2008-01-01

    Full Text Available Los sistemas de producción ganaderos de la región de Tierra Caliente están vinculados al manejo agrosilvopastoril, aprovechando una amplia gama de recursos forrajeros naturales, siendo las familias quienes conducen la administración y aprovechamiento de dichos recursos. Se buscó definir las características, recursos forrajeros aprovechables e insumos alimenticios, estimando su calidad nutricional, con el fin de encontrar estrategias de alimentación de ganado que reduzcan al mínimo el uso de insumos externos al interior de las unidades productivas. Se trabajó en comunidades del municipio de Tuzantla, en la región de Tierra Caliente del estado de Michoacán. El método incluye la recolección de información por medio de encuestas aplicadas a productores campesinos, durante el ciclo productivo 2007. Se analizaron de 200 a 300 g de 41 muestras de alimentos con el método de Wendee, para analizar su composición química. Se encontró que para la región de Tierra Caliente existe un sistema de producción bovina de mediana escala, semi-estabulado y trashumante que, en promedio, tiene 250 a 260 ha y 86 cabezas de ganado destinado a la producción de carne y pie de cría, y que producen 9.2 l/vaca/día; con esta leche se elabora queso a razón de 1kg de queso por cada 10 litros de leche. Se identificó, también, el uso de seis ingredientes fundamentales que componen dos dietas básicas, cuya composición química detectada fue de 10.2- 13.9% (PC, 7.9-11.8% (FC, 62.8-67.9% (ELN, 1.4-5% (EE y 1.9-8.8% (cenizas. Por tanto, se concluye que los ganaderos cubren los requerimientos nutricionales con base en el alto uso de concentrados, dejando los forrajes para satisfacer las necesidades de consumo de su ganado. Por esto, se requiere establecer un sistema de balanceo de raciones que permita optimizar los recursos

  8. El recurso tierra en Costa Rica

    Directory of Open Access Journals (Sweden)

    Floria Bertsch

    2006-01-01

    Full Text Available En este artículo se presenta un análisis sistemático de la evolución del recurso tierra durante los últimos 10 años, desde diferentes perspectivas: las instituciones involucradas en su manejo, su uso actual y potencial, la actividad agropecuaria que sustenta dicho recurso a través de diferentes mundos agrícolas, y algunas otras opciones de agricultura sostenible que han surgido recientemente como es la agricultura orgánica. También se analiza el urbanismo, como aquella presión que efectúa la población sobre el recurso, y se discuten algunas alternativas de conservación planteadas a nivel nacional. Como conclusiones de la autora, en términos generales, el tema adolece de falta de información confiable desde hace 20 años, hay una clara tendencia al paso de la tierra de pequeños a más grandes propietarios y un incremento en la “peonización” a partir de la pérdida de la propiedad. El país se dirige hacia una clara dependencia de la compra en mercados extranjeros para la alimentación básica, a pesar de la existencia de nuevas opciones tecnológicas. Existen avances importantes en legislación pero aún están a nivel de papel y en términos urbanísticos, la presión social vence el ordenamiento territorial.

  9. C60 exposure induced tissue damage and gene expression alterations in the earthworm Lumbricus rubellus

    NARCIS (Netherlands)

    Ploeg, van der M.J.C.; Handy, R.D.; Heckmann, L.H.; Hout, van der A.; Brink, van den N.W.

    2013-01-01

    Effects of C60 exposure (0, 15 or 154 mg/kg soil) on the earthworm Lumbricus rubellus were assessed at the tissue and molecular level, in two experiments. In the first experiment, earthworms were exposed for four weeks, and in the second lifelong. In both experiments, gene expression of heat shock

  10. Bioavailability pathways underlying zinc-induced avoidance behavior and reproduction toxicity in Lumbricus rubellus earthworms.

    NARCIS (Netherlands)

    Ma, W.C.; Bonten, L.T.C.

    2011-01-01

    We investigated possible bioavailability pathways underlying zinc-induced avoidance behavior and sublethal reproduction impairment in Lumbricus rubellus. Clay-loam (pH 7.3) and sandy soil (three pH values of 4.3–6.0) were amended with zinc sulfate at six soil concentrations of total Zn ranging from

  11. In vitro nanoparticle toxicity to rat alveolar cells and coelomocytes from the earthworm Lumbricus rubelles

    NARCIS (Netherlands)

    Ploeg, van der M.J.C.; Berg, van den J.H.J.; Bhattacharjee, S.; Haan, de L.H.J.; Ershov, D.S.; Fokkink, R.G.; Zuilhof, H.; Rietjens, I.M.C.M.; Brink, van den N.W.

    2014-01-01

    Sensitivity of immune cells (coelomocytes) of Lumbricus rubellus earthworms was investigated for exposure to selected nanoparticles, in order to obtain further insight in mechanisms of effects observed after in vivo C60 exposure. In the in vivo study, tissue damage appeared to occur without

  12. Flooding responses of three earthworm species, Allolobophora chlorotica, Aporrectodea caliginosa and Lumbricus rubellus, in a laboratory-controlled environment.

    NARCIS (Netherlands)

    Zorn, M.I.; van Gestel, C.A.M.; Morrien, E.; Wagenaar, M.; Eijsackers, H.J.P.

    2008-01-01

    To get a better understanding of earthworm' responses towards flooding, three laboratory experiments were performed with the species Allolobophora chlorotica, Aporrectodea caliginosa and Lumbricus rubellus. Flooding response was determined in a pot experiment, in which the earthworms were incubated

  13. Flooding responses of three earthworm species, Allolobophora chlorotica, Aporrectodea caliginosa and Lumbricus rubellus, in a laboratory-controlled environment

    NARCIS (Netherlands)

    Zorn, M.I.; Gestel, van C.A.M.; Morriën, W.E.; Wagenaar, M.; Eijsackers, H.J.P.

    2008-01-01

    To get a better understanding of earthworm' responses towards flooding, three laboratory experiments were performed with the species Allolobophora chlorotica, Aporrectodea caliginosa and Lumbricus rubellus. Flooding response was determined in a pot experiment, in which the earthworms were incubated

  14. PENAMBAHAN CACING TANAH Lumbricus rubellus DAN KEONG MAS Pomacea canaliculata PADA PAKAN AYAM PETELUR DALAM PENINGKATAN KANDUNGAN OMEGA 3 PADA TELUR

    OpenAIRE

    Farmansyah, Muarif

    2015-01-01

    ABSTRAK Penelitian tentang Penambahan Cacing Tanah Lumbricus rubellus dan Keong mas Pomacea canaliculata Pada Pakan Ayam Petelur Dalam Peningkatan Kandungan Omega 3 Pada Telur bertujuan untuk mengetahui hubungan penambahan Cacing tanah Lumbricus rubellus dan Keong mas Pomaceacanaliculata L pada ayam petelur dalam meningkatkan kandungan omega 3. Komposisi pakan yang digunakan antara lain P1 = Pakan standar 80% + 15% cacing tanah lumbricus rubellus+ 5%keong mas Pomacea canaliculata L, P2 =...

  15. La temperatura del interior de la tierra

    Directory of Open Access Journals (Sweden)

    Eslava R. Jesús A.

    1993-10-01

    Full Text Available The problem of defining the Earth interior temperature is analized from Heat Flow observations and the acceptance of convection processes in the mantle. Comparative analyses of thermal, adiabatic, and melting point profiles, allow to obtain the optimum temperature profile, wich fits the seismic model of a liquid external core.

    EI problema de definir la temperatura del interior de la Tierra, se analiza a partir de las observaciones del flujo térmico y la aceptación de procesos de convección en el manto.

    Análisis comparativos de perfiles térmicos, adiabáticos y de puntos de fusión, permiten obtener un perfil óptimo de distribución de temperaturas, que además satisface la observación sísmica de un núcleo externo líquido.

  16. La ofensiva hacia las tierras comunales indígenas.

    OpenAIRE

    Bonnet Vélez, Diana

    2014-01-01

    El artículo se concentra en el estudio de las luchas de poder ejercida por algunos actores sociales, especialmente curas, corregidores, "vecinos" y hacendados en relación con la reforma de las tierras comunales indígenas en la segunda mitad del siglo XVIII. La investigación ofrece un panorama general de la actuación de cada uno de estos sujetos sociales, especificando en cada caso el impacto causado en el proceso de reducción de tierras de resguardo y en la conformación de una nueva organizac...

  17. Single-particle cryo-EM using alignment by classification (ABC): the structure ofLumbricus terrestrishaemoglobin.

    Science.gov (United States)

    Afanasyev, Pavel; Seer-Linnemayr, Charlotte; Ravelli, Raimond B G; Matadeen, Rishi; De Carlo, Sacha; Alewijnse, Bart; Portugal, Rodrigo V; Pannu, Navraj S; Schatz, Michael; van Heel, Marin

    2017-09-01

    Single-particle cryogenic electron microscopy (cryo-EM) can now yield near-atomic resolution structures of biological complexes. However, the reference-based alignment algorithms commonly used in cryo-EM suffer from reference bias, limiting their applicability (also known as the 'Einstein from random noise' problem). Low-dose cryo-EM therefore requires robust and objective approaches to reveal the structural information contained in the extremely noisy data, especially when dealing with small structures. A reference-free pipeline is presented for obtaining near-atomic resolution three-dimensional reconstructions from heterogeneous ('four-dimensional') cryo-EM data sets. The methodologies integrated in this pipeline include a posteriori camera correction, movie-based full-data-set contrast transfer function determination, movie-alignment algorithms, (Fourier-space) multivariate statistical data compression and unsupervised classification, 'random-startup' three-dimensional reconstructions, four-dimensional structural refinements and Fourier shell correlation criteria for evaluating anisotropic resolution. The procedures exclusively use information emerging from the data set itself, without external 'starting models'. Euler-angle assignments are performed by angular reconstitution rather than by the inherently slower projection-matching approaches. The comprehensive 'ABC-4D' pipeline is based on the two-dimensional reference-free 'alignment by classification' (ABC) approach, where similar images in similar orientations are grouped by unsupervised classification. Some fundamental differences between X-ray crystallography versus single-particle cryo-EM data collection and data processing are discussed. The structure of the giant haemoglobin from Lumbricus terrestris at a global resolution of ∼3.8 Å is presented as an example of the use of the ABC-4D procedure.

  18. Organic Fertilizer Production From Cattle Waste Vermicomposting Assisted by Lumbricus Rubellus

    OpenAIRE

    Sumardiono, Siswo; Murwono, R.P. Djoko; Nugroho, Amin

    2011-01-01

    Composting is decomposition of compound in organic waste by specific treatment using microorganism aerobically. Natural composting for producing organic fertilizer from manure and market waste utilize long time processing and less equal to the market demand. Vermicomposting is a technique to produce high quality compos fertilizer from biodegradable garbage and mixture of red worm (Lumbricus Rubellus). In conventional compos production took 8 weeks of processing time, in vermicomposting only t...

  19. Bryophyte-cyanobacteria associations during primary succession in recently Deglaciated areas of Tierra del Fuego (Chile).

    Science.gov (United States)

    Arróniz-Crespo, María; Pérez-Ortega, Sergio; De Los Ríos, Asunción; Green, T G Allan; Ochoa-Hueso, Raúl; Casermeiro, Miguel Ángel; de la Cruz, María Teresa; Pintado, Ana; Palacios, David; Rozzi, Ricardo; Tysklind, Niklas; Sancho, Leopoldo G

    2014-01-01

    Bryophyte establishment represents a positive feedback process that enhances soil development in newly exposed terrain. Further, biological nitrogen (N) fixation by cyanobacteria in association with mosses can be an important supply of N to terrestrial ecosystems, however the role of these associations during post-glacial primary succession is not yet fully understood. Here, we analyzed chronosequences in front of two receding glaciers with contrasting climatic conditions (wetter vs drier) at Cordillera Darwin (Tierra del Fuego) and found that most mosses had the capacity to support an epiphytic flora of cyanobacteria and exhibited high rates of N2 fixation. Pioneer moss-cyanobacteria associations showed the highest N2 fixation rates (4.60 and 4.96 µg N g-1 bryo. d-1) very early after glacier retreat (4 and 7 years) which may help accelerate soil development under wetter conditions. In drier climate, N2 fixation on bryophyte-cyanobacteria associations was also high (0.94 and 1.42 µg N g-1 bryo. d-1) but peaked at intermediate-aged sites (26 and 66 years). N2 fixation capacity on bryophytes was primarily driven by epiphytic cyanobacteria abundance rather than community composition. Most liverworts showed low colonization and N2 fixation rates, and mosses did not exhibit consistent differences across life forms and habitat (saxicolous vs terricolous). We also found a clear relationship between cyanobacteria genera and the stages of ecological succession, but no relationship was found with host species identity. Glacier forelands in Tierra del Fuego show fast rates of soil transformation which imply large quantities of N inputs. Our results highlight the potential contribution of bryophyte-cyanobacteria associations to N accumulation during post-glacial primary succession and further describe the factors that drive N2-fixation rates in post-glacial areas with very low N deposition.

  20. Bryophyte-Cyanobacteria Associations during Primary Succession in Recently Deglaciated Areas of Tierra del Fuego (Chile)

    Science.gov (United States)

    Arróniz-Crespo, María; Pérez-Ortega, Sergio; De los Ríos, Asunción; Green, T. G. Allan; Ochoa-Hueso, Raúl; Casermeiro, Miguel Ángel; de la Cruz, María Teresa; Pintado, Ana; Palacios, David; Rozzi, Ricardo; Tysklind, Niklas; Sancho, Leopoldo G.

    2014-01-01

    Bryophyte establishment represents a positive feedback process that enhances soil development in newly exposed terrain. Further, biological nitrogen (N) fixation by cyanobacteria in association with mosses can be an important supply of N to terrestrial ecosystems, however the role of these associations during post-glacial primary succession is not yet fully understood. Here, we analyzed chronosequences in front of two receding glaciers with contrasting climatic conditions (wetter vs drier) at Cordillera Darwin (Tierra del Fuego) and found that most mosses had the capacity to support an epiphytic flora of cyanobacteria and exhibited high rates of N2 fixation. Pioneer moss-cyanobacteria associations showed the highest N2 fixation rates (4.60 and 4.96 µg N g−1 bryo. d−1) very early after glacier retreat (4 and 7 years) which may help accelerate soil development under wetter conditions. In drier climate, N2 fixation on bryophyte-cyanobacteria associations was also high (0.94 and 1.42 µg N g−1 bryo. d−1) but peaked at intermediate-aged sites (26 and 66 years). N2 fixation capacity on bryophytes was primarily driven by epiphytic cyanobacteria abundance rather than community composition. Most liverworts showed low colonization and N2 fixation rates, and mosses did not exhibit consistent differences across life forms and habitat (saxicolous vs terricolous). We also found a clear relationship between cyanobacteria genera and the stages of ecological succession, but no relationship was found with host species identity. Glacier forelands in Tierra del Fuego show fast rates of soil transformation which imply large quantities of N inputs. Our results highlight the potential contribution of bryophyte-cyanobacteria associations to N accumulation during post-glacial primary succession and further describe the factors that drive N2-fixation rates in post-glacial areas with very low N deposition. PMID:24819926

  1. Bryophyte-cyanobacteria associations during primary succession in recently Deglaciated areas of Tierra del Fuego (Chile.

    Directory of Open Access Journals (Sweden)

    María Arróniz-Crespo

    Full Text Available Bryophyte establishment represents a positive feedback process that enhances soil development in newly exposed terrain. Further, biological nitrogen (N fixation by cyanobacteria in association with mosses can be an important supply of N to terrestrial ecosystems, however the role of these associations during post-glacial primary succession is not yet fully understood. Here, we analyzed chronosequences in front of two receding glaciers with contrasting climatic conditions (wetter vs drier at Cordillera Darwin (Tierra del Fuego and found that most mosses had the capacity to support an epiphytic flora of cyanobacteria and exhibited high rates of N2 fixation. Pioneer moss-cyanobacteria associations showed the highest N2 fixation rates (4.60 and 4.96 µg N g-1 bryo. d-1 very early after glacier retreat (4 and 7 years which may help accelerate soil development under wetter conditions. In drier climate, N2 fixation on bryophyte-cyanobacteria associations was also high (0.94 and 1.42 µg N g-1 bryo. d-1 but peaked at intermediate-aged sites (26 and 66 years. N2 fixation capacity on bryophytes was primarily driven by epiphytic cyanobacteria abundance rather than community composition. Most liverworts showed low colonization and N2 fixation rates, and mosses did not exhibit consistent differences across life forms and habitat (saxicolous vs terricolous. We also found a clear relationship between cyanobacteria genera and the stages of ecological succession, but no relationship was found with host species identity. Glacier forelands in Tierra del Fuego show fast rates of soil transformation which imply large quantities of N inputs. Our results highlight the potential contribution of bryophyte-cyanobacteria associations to N accumulation during post-glacial primary succession and further describe the factors that drive N2-fixation rates in post-glacial areas with very low N deposition.

  2. Estado, mercado de tierra urbana e inundaciones en ciudades argentinas

    Directory of Open Access Journals (Sweden)

    Clichevsky Nora

    2006-10-01

    Full Text Available En este trabajo se presentan los resultados de una investigación sobre las relaciones que se establecen entre los mercados de tierra urbana y las inundaciones en ciudades argentinas, en el marco más amplio de la vulnerabilidad urbana. Se pretende despejar incógnitas acerca del papel jugado por el Estado como regulador del mercado en áreas urbanas con vulnerabilidad natural a la inundación y como constructor de defensas contra las inundaciones y acerca de los impactos que han tenido las inundaciones y las obras de defensa contra ellas sobre el mercado de tierra y, por lo tanto, sobre el acceso al suelo urbano por parte de los distintos sectores de la población.

  3. Saber tradicional, ética de la tierra y sustentabilidad

    Directory of Open Access Journals (Sweden)

    Heyd, Thomas

    2005-06-01

    Full Text Available This is the crucial moment to take on sustainable forms of life, and hence it is now of primary importance to adopt a land ethic that takes into account not only the use value but also the intrinsic value of the beings that make up our natural environment. In this essay I begin by focusing on the obstacles that the development of a land ethic has to face, obstacles that are due to limitations in knowledge and to mistaken assumptions. As a way to resolve these practical difficulties I first point out the existence of our natural inclinations toward the land and life. Furthermore, I propose that the traditional knowledge of those peoples that have lived for extended periods with their environments can serve us as models for the development of a culture of appreciation for the earth and its inhabitants.

    Éste ese! momento crucial para emprender formas de vida sustentables, por lo que resulta esencial adoptar una ética de la tierra que reconozca el valor intrínseco además del valor útil de los seres que pueblan nuestro medio ambiente natural. En este ensayo empiezo enfocando los obstáculos a que se enfrenta el desarrollo de una ética de la tierra, obstáculos que resultan ser el producto de conocimientos limitados y suposiciones equivocadas. En resolución de esas problemáticas prácticas apunto, primero, la existencia de inclinaciones naturales hacia la tierra y la vida. Además propongo que en el saber tradicional de los pueblos que han convivido mucho tiempo con sus espacios tenemos modelos de formas del conocer que nos pueden servir de modelo para llegar a desarrollar una cultura de aprecio de la tierra y de sus habitantes.

  4. Charles Darwin's Observations on the Behaviour of Earthworms and the Evolutionary History of a Giant Endemic Species from Germany, Lumbricus badensis (Oligochaeta: Lumbricidae)

    International Nuclear Information System (INIS)

    Kutschera, U.; Elliott, M.

    2010-01-01

    The British naturalist Charles Darwin (1809/1882) began and ended his almost 45-year-long career with observations, experiments, and theories related to earthworms. About six months before his death, Darwin published his book on The Formation of Vegetable Mould, through the Actions of Worms, With Observations on their Habits (1881). Here we describe the origin, content, and impact of Darwin's last publication on earthworms (subclass Oligochaeta, family Lumbricidae) and the role of these annelids as global ecosystem re workers (concept of bioturbation). In addition, we summarize our current knowledge on the reproductive behaviour of the common European species Lumbricus terrestris. In the second part of our account we describe the biology and evolution of the giant endemic species L. badensis from south western Germany with reference to the principle of niche construction. Bio geographic studies have shown that the last common ancestor of L. badensis, and the much smaller sister-taxon, the Atlantic-Mediterranean L. friendi, lived less than 10000 years ago. Allopatric speciation occurred via geographically isolated founder populations that were separated by the river Rhine so that today two earthworm species exist in different areas.

  5. Charles Darwin's Observations on the Behaviour of Earthworms and the Evolutionary History of a Giant Endemic Species from Germany, Lumbricus badensis (Oligochaeta: Lumbricidae

    Directory of Open Access Journals (Sweden)

    U. Kutschera

    2010-01-01

    Full Text Available The British naturalist Charles Darwin (1809–1882 began and ended his almost 45-year-long career with observations, experiments, and theories related to earthworms. About six months before his death, Darwin published his book on The Formation of Vegetable Mould, through the Actions of Worms, With Observations on their Habits (1881. Here we describe the origin, content, and impact of Darwin's last publication on earthworms (subclass Oligochaeta, family Lumbricidae and the role of these annelids as global “ecosystem reworkers” (concept of bioturbation. In addition, we summarize our current knowledge on the reproductive behaviour of the common European species Lumbricus terrestris. In the second part of our account we describe the biology and evolution of the giant endemic species L. badensis from south western Germany with reference to the principle of niche construction. Biogeographic studies have shown that the last common ancestor of L. badensis, and the much smaller sister-taxon, the Atlantic-Mediterranean L. friendi, lived less than 10 000 years ago. Allopatric speciation occurred via geographically isolated founder populations that were separated by the river Rhine so that today two earthworm species exist in different areas.

  6. MORPHOMETRIC PARAMETERS AND MICRORELIEF OF THE LUMBRICUS CELOMOCYTES IN THE CONDITIONS OF THE OSMOTIC PRESSURE

    Directory of Open Access Journals (Sweden)

    Andrey Andreevich Prisnyi

    2017-10-01

    Full Text Available Background: Study the morphometric parameters and microrelief of the coelomocytes membrane of the Lumbricus representatives in normal and under osmotic pressure. Materials and methods: In the experiments, representatives of three species belonging to the genus Lumbricus were used. To conduct each series of experiments a coelomic liquid of 15 representatives of each species was used. From the circulation system of each individual examined, at least 250 cells were processed. The study of morphometric parameters of coelomocytes was carried out in isotonic conditions, and also with the use of osmotic tests in vitro. The features of the surface topography of coelomocytes were study using the “Integra Vita Probe Nanaboratorium” (NT-MDT, Russia. The analysis of amplitude and functional average statistical parameters of membrane roughness is carried out. The results of the research were processed using statistics methods using the Microsoft Excel 7.0 analysis package. Results: The Lumbricus representatives of revealed differences in the responses of amoebocytes and eleocytes to the effect of osmotic stress. Under the conditions of osmotic pressure, several morphologically different forms were found among the cells of each type. This indicates the potential ability of coelomocytes to spread out on the substrate for any type of osmotic pressure. The change in the topography of the cell membrane of coelomocytes under the hypoosmotic pressure is characterized by a smoothing of the microrelief structures with a decrease in the size of the microvysings and microinvaginations. Conclusion: The microrelief of the coelomocytes membrane reflects the features of their functional status changing under the influence of environmental factors.

  7. Uji in Vitro Penghambatan Aktivitas Escherichia Coli Dengan Tepung Cacing Tanah (Lumbricus Rubellus)

    OpenAIRE

    Julendra, H; Sofyan, A

    2007-01-01

    This research was conducted to study the inhibition growth of E. coli by using earthworm (Lumbricus rubellus) meal. The earthworm meal was used in various concentrations, i.e. 0, 25, 50, 75 and 100 mg of earthworm meal in 100 ml DMSO for 0%, 25%, 50%, 75% and 100% (w/v) as treatments respectively. Data were analyzed by ANOVA in Randomized Complete Block Design. Duncan's multiple range test and polynomials orthogonal were used. Inhibition effects were measured through agar well diffusion test....

  8. Uji in Vitro Penghambatan Aktivitas Escherichia coli dengan Tepung Cacing Tanah (Lumbricus rubellus)

    OpenAIRE

    H. Julendra; A. Sofyan

    2007-01-01

    This research was conducted to study the inhibition growth of E. coli by using earthworm (Lumbricus rubellus) meal. The earthworm meal was used in various concentrations, i.e. 0, 25, 50, 75 and 100 mg of earthworm meal in 100 ml DMSO for 0%, 25%, 50%, 75% and 100% (w/v) as treatments respectively. Data were analyzed by ANOVA in Randomized Complete Block Design. Duncan’s multiple range test and polynomials orthogonal were used. Inhibition effects were measured through agar well diffusion test....

  9. Terrestrial magnetosphere

    International Nuclear Information System (INIS)

    Pande, D.C.; Agarwal, D.C.

    1982-01-01

    This paper presents a review about terrestrial magnetosphere. During the last few years considerable investigation have been carried out about the properties of Solar Wind and its interaction with planetary magnetic fields. It is therefore of high importance to accumulate all the investigations in a comprehensive form. The paper reviews the property of earth's magnetosphere, magnetosheath, magneto pause, polar cusps, bow shook and plasma sheath. (author)

  10. Construcción con tierra en el siglo XXI

    Directory of Open Access Journals (Sweden)

    Bestraten, S.

    2011-09-01

    Full Text Available Earthen construction during the 21rst century first decade has resurfaced worldwide as a sustainable, low environmental impact and great expressive material. The research and the number of projects has been increased related to the growth of the associations, institutions, universities and events surrounding this sector. These projects have managed to modernize the traditional techniques of building with earth in order to adapt them to today’s projecting needs, and have been widely recognized for its quality. The aim of this article is to provide a global view on earth construction internationally, providing technical data of its utilization in contemporary architectural projects.

    La construcción con tierra durante la primera década del siglo XXI ha resurgido en todo el mundo como un material con propiedades sostenibles, de bajo impacto ambiental y de gran capacidad expresiva. Se ha experimentado un crecimiento a nivel de proyectos e investigaciones sobre el material relacionado con el aumento de número de asociaciones, instituciones, universidades y eventos alrededor de este sector. Los proyectos actuales han sabido modernizar las técnicas tradicionales de construcción con tierra para adaptarlas a las necesidades proyectuales y constructivas, siendo ampliamente reconocidos por su calidad. El objetivo de este artículo es ofrecer una visión actual sobre la construcción con tierra a nivel internacional, aportando datos técnicos de su utilización en proyectos arquitectónicos contemporáneos.

  11. Elementos traza, tierras raras y boro en sistemas hidrotermales de alta temperatura de México /

    OpenAIRE

    Bernard Romero, Ruben Alejandro

    2012-01-01

     tesis que para obtener el grado de Doctorado en Ciencias de la Tierra, presenta Ruben Alejandro Bernard Romero ; asesor Iouri Taran201 páginas : ilustracionesDoctorado en Ciencias de la Tierra UNAM, Instituto de Geofísica, 2012

  12. Guatemala cafetalera: tierra, trabajo y política

    OpenAIRE

    Gudmundson K, Lowell

    2012-01-01

    IntroducciónHace ya casi una década, el historiador guatemalteco Julio Castellanos Cambranes presentó el primer volumen de lo que se anunciaba como una trilogía sobre la historia agraria de su país. A partir de 1992 nos ofrece una compilación en dos volúmenes de historia agraria guatemalteca en donde se destacan los temas del café y de sus sistemas de trabajo y tenencia de tierra. Pero fuera del trabajo incansable de Cambranes es relativamente poco lo que se ha publicado recientemente en Guat...

  13. Sol, Tierra y Luna. Movimientos relativos y sus consecuencias

    Directory of Open Access Journals (Sweden)

    Sebastián Cardenete García

    2011-01-01

    Full Text Available Cuando se pregunta a los estudiantes por la causa de las estaciones suelen responder: "en verano estamos más próximos al Sol y en invierno estamos más lejos del Sol". La persistencia de esta idea y el hecho de su generalización entre los estudiantes y muchos adultos me ha inducido a escribir este artículo, en el cual se trata de explicar, de una forma clara y simple, el motivo de este y otros fenómenos debidos al movimiento de la Luna alrededor de la Tierra y de ésta alrededor del Sol.

  14. Enhanced bioremoval of lead by earthworm-Lumbricus terrestris co-cultivated with bacteria-Klebsiella variicola.

    Science.gov (United States)

    Das, Anamika; Osborne, Jabez W

    2017-10-01

    Lead is a toxic heavy metal having devastating effects on the environment. The current study was focussed on bioremoval of lead using earthworm and lead resistant bacteria. Earthworms were subjected to various concentrations of lead in the soil bioaugmented with lead resistant bacteria (VITMVCJ1) to enhance the uptake of lead from the contaminated soil. Significant increase was observed in the length and body weight of the earthworms supplemented with lead resistant bacteria. Similarly, there was a substantial increase in the locomotion rate of the earthworms treated with lead resistant bacteria in comparison with the control. The gut micro flora of bacterial treated earthworms had increased number of bacterial cells than the untreated earthworms. The histopathological studies revealed the toxic effects of lead on the gut of earthworms indicating severe damage in lead resistant bacteria untreated worms, whereas the cells were intact in lead resistant bacteria treated worms. COMET assay showed increased DNA damage with higher tail DNA percent in the untreated earthworms. Further, the colonisation of the bacteria supplemented, onto the gut region of earthworms was observed by scanning electron microscopy. Atomic absorption spectrophotometry indicated a fair 50% uptake of lead within the biomass of earthworm treated with lead resistant bacteria. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Quantifying copper and cadmium impacts on intrinsic rate of population increase in the terrestrial oligochaete lumbricus rubellus

    NARCIS (Netherlands)

    Spurgeon, D.J.; Svendsen, C.; Weeks, J.M.; Hankard, P.K.; Stubberud, H.E.; Kammenga, J.E.

    2003-01-01

    Demographic methods can translate toxicant effects on individuals into consequences for populations. To date few such studies have been conducted with longer-lived invertebrates. This is because full life-cycle experiments are difficult with such species. Here we report the effects of copper and

  16. 1904 : rebelión en la Tierra de Campos

    Directory of Open Access Journals (Sweden)

    Jesús-Ángel Redondo Cardeñoso

    2010-01-01

    Full Text Available En este trabajo intentamos explicar el porqué de la oleada de huelgas agrícolas que tuvo lugar en Castilla durante el año 1904, y para ello, nos centraremos en el estudio de lo acontecido en la comarca castellano-leonesa de Tierra de Campos, centro neurálgico de la conflictividad que protagonizó el campesino castellano durante ese año. La investigación se basa en el estudio, aparte de la usada Memoria de Adolfo A. Buylla, de la prensa provincial y documentación militar y judicial.In this paper, we try to explain the reason for the spate of farming strikes, that it took place in Castile during the 1904, and for it, we focus our research in the region of Old Castile called Tierra de Campos, that it was the principal area of the disputes were led by the Castilian peasant during that year. The research is based on the study, besides of the trite Memoria of Adolfo A. Buylla, the provincial press and the military and judicial papers.

  17. Terrestrial radioecology

    International Nuclear Information System (INIS)

    Ohmomo, Yoichiro

    1992-01-01

    Environmental radioecology is a science of studying radionuclide transfer and distribution in the environmental ecosystem and the effects of radiation of the ecosystem. This review highlights radionuclide transfer to crops. There is, however, limited data available on this field in Japan. Therefore, a history of environmental radioecological study in Japan is briefly mentioned: radioecological study has been reflected by social backgrounds, including nuclear explosion and peaceful application of radionuclides. In view of the relationship between siting of nuclear installations and dietary habits for Japanese, research on hydrological radioecology has actually preceded that of terrestrial radioecology. Transfer parameters are discussed in terms of deposition velosity, interception fraction, environmental halftimes, and transfer coefficients from soils to crops. (N.K.) 50 refs

  18. Metal accumulation in the earthworm Lumbricus rubellus. Model predictions compared to field data

    International Nuclear Information System (INIS)

    Veltman, Karin; Huijbregts, Mark A.J.; Vijver, Martina G.; Peijnenburg, Willie J.G.M.; Hobbelen, Peter H.F.; Koolhaas, Josee E.; Gestel, Cornelis A.M. van; Vliet, Petra C.J. van; Jan Hendriks, A.

    2007-01-01

    The mechanistic bioaccumulation model OMEGA (Optimal Modeling for Ecotoxicological Applications) is used to estimate accumulation of zinc (Zn), copper (Cu), cadmium (Cd) and lead (Pb) in the earthworm Lumbricus rubellus. Our validation to field accumulation data shows that the model accurately predicts internal cadmium concentrations. In addition, our results show that internal metal concentrations in the earthworm are less than linearly (slope < 1) related to the total concentration in soil, while risk assessment procedures often assume the biota-soil accumulation factor (BSAF) to be constant. Although predicted internal concentrations of all metals are generally within a factor 5 compared to field data, incorporation of regulation in the model is necessary to improve predictability of the essential metals such as zinc and copper. - Earthworm metal concentrations are less than linearly related to total soil concentrations and predicted pore water concentrations

  19. Uji in Vitro Penghambatan Aktivitas Escherichia coli dengan Tepung Cacing Tanah (Lumbricus rubellus

    Directory of Open Access Journals (Sweden)

    H. Julendra

    2007-04-01

    Full Text Available This research was conducted to study the inhibition growth of E. coli by using earthworm (Lumbricus rubellus meal. The earthworm meal was used in various concentrations, i.e. 0, 25, 50, 75 and 100 mg of earthworm meal in 100 ml DMSO for 0%, 25%, 50%, 75% and 100% (w/v as treatments respectively. Data were analyzed by ANOVA in Randomized Complete Block Design. Duncan’s multiple range test and polynomials orthogonal were used. Inhibition effects were measured through agar well diffusion test. Results showed that earthworm meal contain antibacterial compound which inhibit E. coli activity. There was a significant difference (P0.05 with 75% (w/v. It is concluded that earthworm meal is capable to inhibit E. coli in-vitro at the optimum level of 50% (w/v.

  20. Synergism of Lumbricus rubellus and Pseudomonas putida Pf-20 in Inducing Resistance to Cucumber Mosaic Virus

    Directory of Open Access Journals (Sweden)

    WIWIEK SRI WAHYUNI

    2006-09-01

    Full Text Available Both Lumbricus rubellus and Pseudomonas putida decompose soil organic matters. The population of P. putida Pf-20 increased if L. rubellus was introduced to the cucumber growth medium. The process of organic decomposition was much better if the medium was introduced with both L. rubellus and P. putida Pf-20, compared to the medium contained only either one of those organisms. The activity of L. rubellus may serve to provide nutrients for both the cucumber and P. putida. The role of P. putida to reduce disease severity was increased if L. rubellus was introduced to the growth medium. The synergism of these two organisms, reduced either the level of disease severity to CMV-48 and C/N ratio of medium, but increased the content of available phosphor and potassium.

  1. Terrestrial ecology

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The main effort of the Terrestrial Ecology Division has been redirected to a comprehensive study of the Espiritu Santo Drainage Basin located in northeastern Puerto Rico. The general objective are to provide baseline ecological data for future environmental assessment studies at the local and regional levels, and to provide through an ecosystem approach data for the development of management alternatives for the wise utilization of energy, water, and land resources. The interrelationships among climate, vegetation, soils, and man, and their combined influence upon the hydrologic cycle will be described and evaluated. Environmental management involves planning and decision making, and both require an adequate data base. At present, little is known about the interworkings of a complete, integrated system such as a drainage basin. A literature survey of the main research areas confirmed that, although many individual ecologically oriented studies have been carried out in a tropical environment, few if any provide the data base required for environmental management. In view of rapidly changing socio-economic conditions and natural resources limitations, management urgently requires data from these systems: physical (climatological), biological, and cultural. This integrated drainage basin study has been designed to provide such data. The scope of this program covers the hydrologic cycle as it is affected by the interactions of the physical, biological, and cultural systems

  2. La arquitectura en tierra: Una alternativa para la construcción sostenible

    Directory of Open Access Journals (Sweden)

    Gloria Zuleta Roa

    2011-12-01

    Full Text Available La inquietud sobre la sostenibilidad de la arquitectura hecha con tierra se convierte en el punto de partida para escribir este artículo sobre el uso de la tierra como alternativa para realizar construcciones sostenibles. Se inicia con una mirada histórica del uso de la tierra como material de construcción en el mundo y en Colombia; sus características en relación con la sostenibilidad en los procesos constructivos y finalmente su contextualización dentro de las normas que regulan la construcción.

  3. Effects of silver nanoparticles (NM-300K) on Lumbricus rubellus earthworms and particle characterization in relevant test matrices including soil

    NARCIS (Netherlands)

    Ploeg, M.J.C. van der; Handy, R.D.; Waalewijn-Kool, P.L.; Berg, J.H.J. van den; Herrera Rivera, Z.E.; Bovenschen, J.; Molleman, B.; Baveco, J.M.; Tromp, P.; Peters, R.J.B.; Koopmans, G.F.; Rietjens, I.M.C.M.; Brink, N.W. van den

    2014-01-01

    The impact of silver nanoparticles (AgNP; at 0mg Ag/kg, 1.5mg Ag/kg, 15.4mg Ag/kg, and 154mg Ag/kg soil) and silver nitrate (AgNO3; 15.4mg Ag/kg soil) on earthworms, Lumbricus rubellus, was assessed. A 4-wk exposure to the highest AgNP treatment reduced growth and reproduction compared with the

  4. Effectivity of the Earthworms Pheretima hupiensis, Eudrellus sp. and Lumbricus sp. on the Organic Matter Decomposition Process

    Directory of Open Access Journals (Sweden)

    Ea Kosman Anwar

    2009-05-01

    Full Text Available The earthworms are the one of soil fauna component in soil ecosystem have an important role in organic matter decomposition procces. The earthworm feed plant leaf and plant matter up to apart and dissolved. Earthworm metabolisms produce like faeces that mixed with decomposed organic matter mean vermicompost. The vermicompost fertility varies because of some kind of earthworm differ in “niche” and attitude. The experiment was to study the effectivity of earthworm on organic matter decomposition which has been conducted in Soil Biological and Healthy Laboratory and Green House of Soil Research Institute Bogor, during 2006 Budget Year. The three kind of earthworms i.e Pheretima hupiensis, Lumbricus sp. and Eudrellus sp. combined with three kind of organic matter sources i.e rice straw, trash and palm oil plant waste (compost heap. The result shows that the Lumbricus sp. are the most effective decomposer compared to Pheretima hupiensis and Eudrellus sp. and the organic matter decomposed by Lumbricus sp. as followed: market waste was decomposed of 100%, palm oil empty fruit bunch (compost heap 95.8 % and rice straw 84.9%, respectively. Earthworm effectively decreased Fe, Al, Mn, Cu dan Zn.

  5. CO2 and CH4 fluxes of contrasting pristine bogs in southern Patagonia (Tierra del Fuego, Argentina)

    Science.gov (United States)

    Münchberger, Wiebke; Blodau, Christian; Kleinebecker, Till; Pancotto, Veronica

    2015-04-01

    South Patagonian peatlands cover a wide range of the southern terrestrial area and thus are an important component of the terrestrial global carbon cycle. These extremely southern ecosystems have been accumulating organic material since the last glaciation up to now and are - in contrast to northern hemisphere bogs - virtually unaffected by human activities. So far, little attention has been given to these pristine ecosystems and great carbon reservoirs which will potentially be affected by climate change. We aim to fill the knowledge gap in the quantity of carbon released from these bogs and in what controls their fluxes. We study the temporal and spatial variability of carbon fluxes in two contrasting bog ecosystems in southern Patagonia, Tierra del Fuego. Sphagnum-dominated bog ecosystems in Tierra del Fuego are similar to the ones on the northern hemisphere, while cushion plant-dominated bogs can almost exclusively be found in southern Patagonia. These unique cushion plant-dominated bogs are found close to the coast and their occurrence changes gradually to Sphagnum-dominated bogs with increasing distance from the coast. We conduct closed chamber measurements and record relevant environmental variables for CO2 and CH4 fluxes during two austral vegetation periods from December to April. Chamber measurements are performed on microforms representing the main vegetation units of the studied bogs. Gas concentrations are measured with a fast analyzer (Los Gatos Ultraportable Greenhouse Gas Analyzer) allowing to accurately record CH4 fluxes in the ppm range. We present preliminary results of the carbon flux variability from south Patagonian peat bogs and give insights into their environmental controls. Carbon fluxes of these two bog types appear to be highly different. In contrast to Sphagnum-dominated bogs, cushion plant-dominated bogs release almost no CH4 while their CO2 flux in both, photosynthesis and respiration, can be twice as high as for Sphagnum

  6. El nuevo acaparamiento de tierras y las cambiantes dinamicas de la agricultura en el sur de Africa

    OpenAIRE

    Hall, Ruth

    2011-01-01

    El termino 'acaparamiento con fuerza en los ultimos anos para describir el renovado interes de las empresas por la tierra agraria, que se materializado en forma de cerramientos y privatizaciones de tierras a gran escala. Sin embargo, este termino esconde importantes diferencias respecto a la legalidad, la estructura y los resultados de los acuerdos comerciales sobre la tierra, de manera que desvia la atencion respecto al papel desempenado por las elites y los gobernos locales como socios, int...

  7. Earthworm Lumbricus rubellus MT-2: Metal Binding and Protein Folding of a True Cadmium-MT

    Directory of Open Access Journals (Sweden)

    Gregory R. Kowald

    2016-01-01

    Full Text Available Earthworms express, as most animals, metallothioneins (MTs—small, cysteine-rich proteins that bind d10 metal ions (Zn(II, Cd(II, or Cu(I in clusters. Three MT homologues are known for Lumbricus rubellus, the common red earthworm, one of which, wMT-2, is strongly induced by exposure of worms to cadmium. This study concerns composition, metal binding affinity and metal-dependent protein folding of wMT-2 expressed recombinantly and purified in the presence of Cd(II and Zn(II. Crucially, whilst a single Cd7wMT-2 species was isolated from wMT-2-expressing E. coli cultures supplemented with Cd(II, expressions in the presence of Zn(II yielded mixtures. The average affinities of wMT-2 determined for either Cd(II or Zn(II are both within normal ranges for MTs; hence, differential behaviour cannot be explained on the basis of overall affinity. Therefore, the protein folding properties of Cd- and Zn-wMT-2 were compared by 1H NMR spectroscopy. This comparison revealed that the protein fold is better defined in the presence of cadmium than in the presence of zinc. These differences in folding and dynamics may be at the root of the differential behaviour of the cadmium- and zinc-bound protein in vitro, and may ultimately also help in distinguishing zinc and cadmium in the earthworm in vivo.

  8. Acaparamiento de tierras y acumulación global capitalista: aspectos clave en América Latina.

    OpenAIRE

    Landívar, Natalia

    2013-01-01

    El análisis del acaparamiento de la tierra en América Latina está centrado básicamente en dos conceptos: la extranjerización y concentración de la tierra. Por un lado, en varios países como Argentina, Brasil, Uruguay, Paraguay y Guatemala la discusión se ha centrado en la extranjerización de la propiedad de la tierra. Esta se refiere a la adquisición de tierra por actores extranjeros, como gobiernos y corporaciones, así como de individuos, para una variedad de propósitos y de diferentes escal...

  9. Effects of silver nanoparticles (NM-300K) on Lumbricus rubellus earthworms and particle characerization in relevant test matrices including soil

    NARCIS (Netherlands)

    Ploeg, van der M.J.C.; Handy, R.D.; Waalewijn-Kool, P.; Berg, van den J.H.J.; Herrera Rivera, Z.E.; Bovenschen, J.; Molleman, B.; Baveco, J.M.; Tromp, P.; Peters, R.J.B.; Koopmans, G.F.; Rietjens, I.; Brink, van den N.W.

    2014-01-01

    The impact of silver nanoparticles (AgNP; at 0¿mg Ag/kg, 1.5¿mg Ag/kg, 15.4¿mg Ag/kg, and 154¿mg Ag/kg soil) and silver nitrate (AgNO3; 15.4¿mg Ag/kg soil) on earthworms, Lumbricus rubellus, was assessed. A 4-wk exposure to the highest AgNP treatment reduced growth and reproduction compared with the

  10. Organic Fertilizer Production From Cattle Waste Vermicomposting Assisted By Lumbricus Rubellus

    Directory of Open Access Journals (Sweden)

    Siswo Sumardiono

    2011-07-01

    Full Text Available Composting is decomposition of compound in organic waste by specific treatment using microorganism aerobically. Natural composting for producing organic fertilizer from manure and market waste utilize long time processing and less equal to the market demand. Vermicomposting is a technique to produce high quality compos fertilizer from biodegradable garbage and mixture of red worm (Lumbricus Rubellus. In conventional compos production took 8 weeks of processing time, in vermicomposting only took half processing time of conventional technique. It is occurred by red worm additional ease cellulose degradation contain in manure which is could not decomposed with composting bacteria. The purposes of this research are to investigate the effect of manure comparison to red worm growth and to evaluate the effect of comparison between manure and market waste to red worm growth. This research was conducted by vary the weight of red worm (100 gr, 200 gr, 300 gr, 400 gr, 500 gr and market waste addition (50 gr, 100 gr, 150 gr, 200 gr, 300 gr. Moreover, 3 kg of manure was mixed by various weight of red worm, while variation of market waste addition was involved 500 gr red worm and 3 kg manure mixture. Optimum increasing weight of red worm that was obtained by 100 gr red worm addition is 160 gr within 2 weeks. In added market waste variation, the highest increasing of red worm was resulted by 50 gr market waste addition, with 60 gr increasing weight of red worm. Production of casting fertilizer was highly effected by composition of used materials such as medium, manure and red worm comparison as well as market waste additional

  11. Assessment of avoidance behaviour by earthworms (Lumbricus rubellus and Octolasion cyaneum) in linear pollution gradients.

    Science.gov (United States)

    Lowe, Christopher N; Butt, Kevin R; Cheynier, Kevin Yves-Marie

    2016-02-01

    Avoidance behaviour by earthworms is recognised as a valuable endpoint in soil quality assessment and has resulted in the development of a standardised test (ISO 17512-1, 2008) providing epigeic earthworms with a choice between test and control soils. This study sought to develop and evaluate an avoidance test utilising soil-dwelling earthworms in linear pollution gradients with Visible Implant Elastomer (VIE) tags used to identify individual organisms. Sequential experiments were established in laboratory-based mesocosms (0.6m×0.13m×0.1m) that determined the relative sensitivities (in terms of associated avoidance behaviour) of Octolasion cyaneum and Lumbricus rubellus at varying levels of polluted soil and also assessed the influence of introduction point on recorded movement within gradients. In an initial gradient (0%, 25%, 50%, 75%, 100% polluted soil), both species exhibited a clear avoidance response with all surviving earthworms retrieved (after 7 days) from the unpolluted soil. In a less polluted gradient (0%, 6.25%, 12.5%, 18.75%, 25%) L. rubellus were retrieved throughout the gradient while O. cyaneum were located within the 0% and 6.25% divisions, suggesting a species-specific response to polluted soil. Results also showed that the use of a linear pollution gradient system has the potential to assess earthworm avoidance behaviour and could provide a more ecologically relevant alternative to the ISO 17512: 2008 avoidance test. However, further work is required to establish the effectiveness of this procedure, specifically in initial chemical screening and assessment of single contaminant bioavailability, where uptake of pollutants by earthworms could be measured and directly related to the point of introduction and retrieval. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Acceso a la tierra y derechos de propiedad campesinos: recorriendo los laberintos

    Directory of Open Access Journals (Sweden)

    Francisco Gutiérrez Sanín

    2016-01-01

    Full Text Available En este artículo analizamos dos modalidades diferentes de debilitamiento y fluidez de los derechos de propiedad sobre la tierra de los campesi­nos: despojo y transacciones entre campesinos, con base en el estudio de los casos de Chivolo y Montes de María en la costa atlántica colombiana. Para ello, esbozamos las líneas de análisis clave en la literatura relevante, en particular en lo relativo a reformas agrarias inclusivas y redistributivas; mostramos los rasgos generales de la trayectoria de la lucha por la tierra en la región; presentamos las limitaciones a la propiedad de la tierra dentro del régimen parcelario, y observamos cómo operaron en los casos analizados. Concluimos que tales limitaciones crean una situación de vulnerabilidad endémica de los derechos de los campesinos.

  13. Trichomycetes living in the guts of aquatic insects of Misiones and Tierra del Fuego, Argentina.

    Science.gov (United States)

    López Lastra, Claudia C; Scorsetti, Ana C; Marti, Gerardo A; Coscarón, Sixto

    2005-01-01

    Fourteen species of Trichomycetes living in the guts of aquatic insects are reported from two provinces of Argentina, Misiones and Tierra del Fuego. Twelve of the species belong to the Harpellales and two are Amoebidiales. Five harpellid species are reported from Misiones in the extreme northeast of the country (Genistellospora homothallica, Harpella tica, Smittium culisetae, Smittium sp., Stachylina sp.) and seven are from Tierra del Fuego, the southern tip of South America (H. meridianalis, Glotzia sp., S. culicis, S. cellaspora, S. imitatum, Stachylina minima, Penella simulii). Insect hosts all were immature stages of Culicidae, Simuliidae, Chironomidae, Ceratopogonidae (Insecta: Diptera), and Ephemeroptera and Plecoptera. The lower diversity of Trichomycetes found at Misiones, which has a subtropical climate and rainforest vegetation, was due possibly to the warmer temperatures of the water (15-24 C), compared to the colder streams of Tierra del Fuego (9-15 C), with forests and steppes as typical vegetation.

  14. Toxicokinetics of metals in the earthworm Lumbricus rubellus exposed to natural polluted soils – relevance of laboratory tests to the field situation

    NARCIS (Netherlands)

    Giska, I.; van Gestel, C.A.M.; Skip, B.; Laskowski, R.

    2014-01-01

    The aim of this study was to estimate the bioavailability of essential (Zn, Cu) and non-essential metals (Cd, Pb) to the earthworm Lumbricus rubellus exposed to soils originating from a gradient of metal pollution in Southern Poland. Metal uptake and elimination kinetics were determined and related

  15. A Geochemical and Sedimentary Record of High Southern Latitude Holocene Climate Evolution from Lago Fagnano, Tierra del Fuego

    Energy Technology Data Exchange (ETDEWEB)

    Moy, C M; Dunbar, R B; Guilderson, T P; Waldmann, N; Mucciarone, D A; Recasens, C; Austin, J A; Anselmetti, F S

    2010-11-19

    Situated at the southern margin of the hemispheric westerly wind belt and immediately north of the Antarctic Polar Frontal zone, Tierra del Fuego is well-positioned to monitor coupled changes in the ocean-atmosphere system of the high southern latitudes. Here we describe a Holocene paleoclimate record from sediment cores obtained from Lago Fagnano, a large lake in southern Tierra del Fuego at 55{sup o}S, to investigate past changes in climate related to these two important features of the global climate system. We use an AMS radiocarbon chronology for the last 8,000 years based on pollen concentrates, thereby avoiding contamination from bedrock-derived lignite. Our chronology is consistent with a tephrochronologic age date for deposits from the middle Holocene Volcan Hudson eruption. Combining bulk organic isotopic ({delta}{sup 13}C and {delta}{sup 15}N) and elemental (C and N) parameters with physical sediment properties allow us to better understand sediment provenance and transport mechanisms and to interpret Holocene climate and tectonic change during the last 8,000 years. Co-variability and long-term trends in C/N ratio, carbon accumulation rate, and magnetic susceptibility reflect an overall Holocene increase in the delivery of terrestrial organic and lithogenic material to the deep eastern basin. We attribute this variability to westerly wind-derived precipitation. Increased wind strength and precipitation in the late Holocene drives the Nothofagus forest eastward and enhances run-off and terrigenous inputs to the lake. Superimposed on the long-term trend are a series of abrupt 9 negative departures in C/N ratio, which constrain the presence of seismically-driven mass flow events in the record. We identify an increase in bulk {delta}{sup 13}C between 7,000 and 5,000 cal yr BP that we attribute to enhanced aquatic productivity driven by warmer summer temperatures. The Lago Fagnano {delta}{sup 13}C record shows similarities with Holocene records of sea surface

  16. Effects of C{sub 60} nanoparticle exposure on earthworms (Lumbricus rubellus) and implications for population dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Ploeg, M.J.C. van der, E-mail: merel.vanderploeg@wur.n [Alterra, Wageningen UR, Droevendaalssesteeg 3, 6700 AA, Wageningen (Netherlands); Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE, Wageningen (Netherlands); Baveco, J.M.; Hout, A. van der [Alterra, Wageningen UR, Droevendaalssesteeg 3, 6700 AA, Wageningen (Netherlands); Bakker, R. [RIKILT, Wageningen UR, Akkermaalsbos 2, 6708 WB, Wageningen (Netherlands); Rietjens, I.M.C.M. [Division of Toxicology, Wageningen University, Tuinlaan 5, 6703 HE, Wageningen (Netherlands); Brink, N.W. van den [Alterra, Wageningen UR, Droevendaalssesteeg 3, 6700 AA, Wageningen (Netherlands)

    2011-01-15

    Effects of C{sub 60} nanoparticles (nominal concentrations 0, 15.4 and 154 mg/kg soil) on mortality, growth and reproduction of Lumbricus rubellus earthworms were assessed. C{sub 60} exposure had a significant effect on cocoon production, juvenile growth rate and mortality. These endpoints were used to model effects on the population level. This demonstrated reduced population growth rate with increasing C{sub 60} concentrations. Furthermore, a shift in stage structure was shown for C{sub 60} exposed populations, i.e. a larger proportion of juveniles. This result implies that the lower juvenile growth rate due to exposure to C{sub 60} resulted in a larger proportion of juveniles, despite increased mortality among juveniles. Overall, this study indicates that C{sub 60} exposure may seriously affect earthworm populations. Furthermore, it was demonstrated that juveniles were more sensitive to C{sub 60} exposure than adults. - C{sub 60} nanoparticle exposure can affect Lumbricus rubellus populations.

  17. Resistance to copper toxicity in populations of the earthworms Lumbricus rubellus and Dendrodrilus rubidus from contaminated mine wastes.

    Science.gov (United States)

    Langdon, C J; Piearce, T G; Meharg, A A; Semple, K T

    2001-10-01

    Two arsenic and heavy metal-contaminated mine spoil sites, at Carrock Fell, Cumbria, United Kingdom, and Devon Great Consols Mine, Devon, United Kingdom, have been found to support populations of the earthworms Lumbricus rubellus Hoffmeister and Dendrodrilus rubidus (Savigny). Lumbricus rubellus and D. rubidus collected from the Devon site and an uncontaminated site were kept for 28 d in uncontaminated soil and in soil containing 750 mg/kg CuCl2, the state of the specimens being recorded using a semiquantitative assessment of earthworm health (condition index). The condition index remained high for all specimens except those of L. rubellus and D. rubidus from uncontaminated sites, which displayed 100% mortality. Bioavailability of Cu in the soils from one uncontaminated and two contaminated sites and in the uncontaminated soil treated with CuCl2 was determined using sequential extraction. Soils from Devon Great Consols had the greatest availability of Cu, Carrock Fell the lowest. Total tissue Cu for L. rubellus and D. rubidus from the contaminated sites did not change significantly for each species during the experiment. Total tissue concentrations of Cu for L. rubellus and D. rubidus from uncontaminated sites increased significantly during the first 7 d, after which mortality was 90%, making it impossible to continue the analysis.

  18. The architecture of the extremes cultural landscapes in Tierra del Fuego

    OpenAIRE

    Garcés Feliú, Eugenio

    2010-01-01

    This paper aims to analyze the relevance of applying the notion of extreme cultural landscape to Tierra del Fuego, as a complementary category to those defined by Unesco. It states that in Chile there are anumber of territories at the margins –in the end, along the border– that have been built as landscapes, specifics and concretes, where the exploitation of natural resources has proved profitable and the building of human settlements as been allowed. This is the case of Tierra del Fuego, con...

  19. La tierra comunal en Andalucía durante la Edad Moderna

    OpenAIRE

    Antonio Miguel BERNAL

    2009-01-01

    RESUMEN: A partir de la ambigüedad conceptual que define a las tierras comunales en Andalucía se estudian, para los siglos XV al XVIII, tres aspectos fundamentales: cómo se llega a formar la propiedad comunal; a través de qué mecanismos —jurídicos y económicos— se van reduciendo las tierras comunales a propiedad privada; y, por último, qué funcionalidad económica habían tenido los comunales en el contexto del sistema agrario andaluz. La escasa población andaluza en la Edad Moderna y la gran d...

  20. Mires and mire types of Peninsula Mitre, Tierra del Fuego, Argentina

    NARCIS (Netherlands)

    Grootjans, A.; Iturraspe, R.; Fritz, C.; Moen, A.; Joosten, H.

    2014-01-01

    In 2007, a field visit by members of the International Mire Conservation Group (IMCG) to the Atlantic coast of Peninsula Mitre (the easternmost part of Isla Grande de Tierra del Fuego, Argentina) gathered information on mire diversity in this remote wild area with largely pristine mires. Our

  1. IMPACTOS DEL CAMBIO DE USO DE LA TIERRA EN LA MICROCUENCA MEMBRILLO, MANABÍ, ECUADOR

    Directory of Open Access Journals (Sweden)

    Alberto Hernández Jiménez

    2013-12-01

    Full Text Available El cambio de uso de la tierra, sobre todo el cambio de tierras forestales a tierras cultivadas, es una de las prácticas que mayor impacto ha tenido en la degradación de los suelos en el mundo y que ha provocado, en gran parte, la emisión de CO2 a la atmósfera. Por esto se hace necesario evaluar los cambios que han tenido las propiedades de los suelos por los diferentes ecosistemas, para de esta forma, tomar las medidas de mejoramiento y conservación de los suelos. En este trabajo, se estudia por primera vez, el cambio de algunas propiedades de los suelos de las partes medias y bajas de la microcuenca Membrillo (provincia de Manabí, Ecuador. Esta microcuenca presenta un relieve alomado, premontañoso, en la cual predominan bosques primarios y secundarios y plantaciones de cacao, pastizales y cultivos como el maíz en su parte baja. Los suelos son Feozems, Cambisoles y Fluvisoles y se presentan los resultados sobre cambios en sus características morfológicas (color, tipo de estructura, espesor de los horizontes A y B, las pérdidas de carbono orgánico y el cambio en la densidad aparente del suelo, provocado por el cambio de uso de la tierra.

  2. Campesinos contra campesinos: conflictos agrarios y lucha por la tierra en Comoapan, Veracruz (1925-1942

    Directory of Open Access Journals (Sweden)

    Rogelio Jiménez Marce

    2013-01-01

    Full Text Available El objetivo del trabajo es mostrar las gestiones que los campesinos de Comoapan, Veracruz, una congregación dependiente en ese momento de San Andrés Tuxtla, hicieron ante las autoridades agrarias para tratar de que les dotara de las fértiles tierras que se dedicaban al cultivo del tabaco, situación que generó un enfrentamiento contra la familia Carrión, misma que era una de las principales productoras de la hoja en la región de los Tuxtlas. Para conservar sus tierras, los Carrión apoyaron la formación de una agrupación campesina, conformada por sus peones y campesinos que no tenían derecho a obtener tierra ejidal, y que se convirtió en antagonista de la que pedía las tierras. Se busca entender los complejos procesos que se vivieron en Comoapan y las interrelaciones que se establecieron entre ejidatarios y no ejidatarios, a fin de mostrar que el reparto agrario no constituyó un proceso carente de problemáticas.

  3. Medidas de resistividad de terrenos e impedancias de puesta a tierra

    OpenAIRE

    Castellanos Domínguez, César Germán

    1993-01-01

    Este libro consta de ocho capítulos: Resistividad del suelo, Medida de impedancia de puesta a tierra, Aspectos prácticos de medidas, Características de los elementos de medición, Seguridad y precauciones en medidas, Potenciales y gradientes, Efectos fisiológicos de la corriente eléctrica e Intensidades de falla.

  4. Un congreso de fisica estudia la composicion de las capas de la tierra

    CERN Multimedia

    2003-01-01

    "El Congreso de Internacional de Neutrinos, que ayer comenzo en el Jardin Botanico de Valencia, aborda, entre otros aspectos, la composicion y el perfil tomografico de las distintas capas de estratos del interior de la Tierra, segun informo a Efe el profesor Jose Furtado Valle" (1/2 page).

  5. Plastic Bag Derived-Microplastics as a Vector for Metal Exposure in Terrestrial Invertebrates.

    Science.gov (United States)

    Hodson, Mark E; Duffus-Hodson, Calum A; Clark, Andy; Prendergast-Miller, Miranda T; Thorpe, Karen L

    2017-04-18

    Microplastics are widespread contaminants in terrestrial environments but comparatively little is known about interactions between microplastics and common terrestrial contaminants such as zinc (Zn). In adsorption experiments fragmented HDPE bags c. one mm 2 in size showed similar sorption characteristics to soil. However, when present in combination with soil, concentrations of adsorbed Zn on a per mass basis were over an order of magnitude lower on microplastics. Desorption of the Zn was minimal from both microplastics and soil in synthetic soil solution (0.01 M CaCl 2 ), but in synthetic earthworm guts desorption was higher from microplastics (40-60%) than soil (2-15%), suggesting microplastics could increase Zn bioavailability. Individual Lumbricus terrestris earthworms exposed for 28 days in mesocosms of 260 g moist soil containing 0.35 wt % of Zn-bearing microplastic (236-4505 mg kg -1 ) ingested the microplastics, but there was no evidence of Zn accumulation, mortality, or weight change. Digestion of the earthworms showed that they did not retain microplastics in their gut. These findings indicate that microplastics could act as vectors to increase metal exposure in earthworms, but that the associated risk is unlikely to be significant for essential metals such as Zn that are well regulated by metabolic processes.

  6. Capitalismo, crisis y naturaleza: Un análisis del acaparamiento de tierras dentro y desde el Sur Global

    OpenAIRE

    Mora, Sol

    2016-01-01

    El acaparamiento de tierras (land grabbing) refiere al proceso de adquisiciones a gran escala de tierras agrícolas en otros estados, desatado en el contexto de la convergencia de crisis internacionales —alimentaria, energética, financiera y climática— de 2008. Este artículo analiza las razones que convirtieron al acaparamiento de tierras en un fenómeno global, irreductible a la lógica Norte-Sur. Adicionalmente, indaga sus implicaciones sobre la posición internacional y definici...

  7. Dispersión-depositación del polen actual en Tierra del Fuego, Argentina Dispersion-depositation of current polen in Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Matilde E. Trivi de Mandri

    2006-06-01

    Full Text Available La estrecha relación existente entre la vegetación y el polen que ésta produce favorece el estudio de las comunidades vegetales desde un punto de vista palinológico. De esta manera es posible obtener información sobre la distribución de la vegetación por medio de la dispersión y depositación de los granos de polen. La caracterización polínica de las comunidades vegetales permite investigar la historia de la vegetación desde la perspectiva actualista. El objetivo de este trabajo es caracterizar la dispersión-depositación del polen actual en relación con la distribución de la vegetación utilizando análisis estadísticos multivariados (clasificación y correspondencia como un paso esencial para futuros estudios de la historia ambiental del Holoceno de la Isla Grande de Tierra del Fuego. El área de estudio está localizada en el sector argentino de la Isla Grande de Tierra del Fuego a 52°40'S-55°7'S; 65°05'O-68°40'O. El resultado de los métodos numéricos y su asociación con los parámetros ambientales ha permitido la diferenciación de un continuum de comunidades que pertenecen a diferentes unidades fisonómicas: bosque y estepa graminosa.The close relationship existing between vegetation and the pollen it produces favours the study of plant communities from a palynological point of view. Therefore, it is possible to have information about the distribution of vegetation by means of the dispersal and deposition of pollen grains. The pollen characterisation of the vegetation communities allows us to investigate the vegetation history from an actualistic point of view. The aim of this work is to characterise the modern pollen dispersal-deposition in relation to the vegetation distribution by using multivariate statistical analysis (cluster and correspondence analyses as an essential step for future studies on the Holocene environmental history of Isla Grande de Tierra del Fuego. The study area is located in the Argentine

  8. Visión de la Concentración de la Tierra en América Latina

    NARCIS (Netherlands)

    C. Kay (Cristóbal)

    2012-01-01

    textabstractEn este breve artículo presento de manera muy general y esquemática algunos aspectos sobre la concentración de la tierra en América Latina. No pretendo hacer un análisis detallado y completo sobre la problemática de la tierra en la región. Pero espero poder resaltar algunos factores que

  9. Introduced Terrestrial Species (Future)

    Data.gov (United States)

    U.S. Environmental Protection Agency — These data represent predicted future potential distributions of terrestrial plants, animals, and pathogens non-native to the Middle-Atlantic region. These data are...

  10. Solar-Terrestrial Interactions

    National Research Council Canada - National Science Library

    Kahler, Stephen W

    2008-01-01

    This report covers a basic research (6.1 level) task on solar-terrestrial interactions carried out in the Space Weather Center of Excellence over an 11-year period for the Air Force Office of Scientific Research...

  11. Las tomas de tierra en el origen y desarrollo del Movimiento de Trabajadores Desocupados del Chaco

    Directory of Open Access Journals (Sweden)

    Maximiliano Román

    2012-01-01

    Full Text Available El Movimiento de Trabajadores Desocupados, en cuanto fenómeno reciente en la sociedad argentina, se vincula de diversas maneras con las formas precedentes de lucha popular. Una de ellas es la “toma” de tierras fiscales o privadas con el objetivo de construir viviendas o emprendimientos productivos.El presente trabajo pretende esclarecer el proceso de génesis y desarrollo de tres organizaciones pertenecientes al Movimiento de Trabajadores Desocupados de la provincia del Chaco y su relación con las tomas de tierra: en primera instancia, como antecedentes de organización territorial que derivaron en la conformación de agrupaciones específicamente “piqueteras”, y posteriormente, como acciones puntuales impulsadas con objetivos preestablecidos por grupos ya constituidos como “piqueteros”.

  12. Design of earth network in electric substations; Diseno de redes de tierra en subestaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Raull-Martin, J. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    2000-09-01

    The purpose of this paper is to present a summarized version of the different types of construction of grounding systems, as web as their materials and formulas, which are necessary and useful for the design and building of a grounding network for medium to high voltage facilities. A description is also made of how to determine the electrical resistivity of subsoil layers with different physical characteristics. Several illustrative examples are also solved in the paper. [Spanish] El proposito de este articulo es presentar de manera resumida los diferentes tipos de construccion de los sistemas de tierra, asi como sus materiales y formulas, los cuales son necesarios y utiles para el diseno y edificacion de una red de tierra para instalaciones de mediana y alta tension. Se describe tambien la obtencion de las diferentes resistividades que presentan los terrenos con diversas caracteristicas fisicas. Asi mismo, se solucionan ejercicios ilustrativos a lo largo del articulo.

  13. Cultural Tourism In Fragile Institutional Contexts Project For Cultural Routes In Tierra Del Fuego

    Directory of Open Access Journals (Sweden)

    Eugenio Garcés Feliú

    2012-12-01

    Full Text Available The following paper presents a project of Cultural Routes designed for the Chilean Tierra del Fuego, linked to promoting tourism and boosting the economy, through the development of a specific high standard tourism offer, linked to its natural and cultural heritage, with the purpose of capturing the potential income generation for Chile. The project had as main goal to enhance the competitiveness of the tourism sector of special interests in Tierra del Fuego, a key sector of Southern Patagonia, through the dissemination and transfer of technologies and knowledge, acquired in over 10 years of research and projects, onto the territory and local agents. These Cultural Routes build an innovative offer, capable of structuring the diverse touristic resources and strengthening the basis for the development of a new stage of national and international tourism market, located on the southern extreme of Chile and America.

  14. La esfera de la tierra plana medieval como invención del siglo XIX

    OpenAIRE

    Páez-Kano, José R.

    2003-01-01

    Contrario a lo aprendido de libros y maestros a lo largo de los años escolares, en la Edad Media no se consideraba a la Tierra plana, sino esférica. Del encuentro de esta información se deriva la presente tesis, en la cual se intenta descifrar por qué los historiadores aseguraban que en el medievo se creía que el mundo era plano. La investigación se desarrolla alrededor de varias preguntas: ¿desde cuándo se sabe de la esfericidad de la Tierra?, ¿qué decían acerca de esto los textos medievales...

  15. Efecto de la impermeabilidad del Mucílago de Nopal en bloques de tierra comprimidos

    Directory of Open Access Journals (Sweden)

    Yolanda Guadalupe Aranda Jiménez

    2013-01-01

    Full Text Available La arquitectura de tierra1 es conocida desde hace siglos, sin embargo, actualmente es poco utilizada comparado con los sistemas constructivos comunes. Los bloques de tierra comprimido (BTC son elementos constructivos con un potencial elevado para ser utilizado en las construcciones de vivienda en México, principalmente por su similitud con los bloques tradicionales, siendo conveniente mejorar sus características a partir de un estabilizante. Se realizó el estudio de BTC estabilizados con cemento y una sustancia proveniente de las pencas maduras de nopal. Se encontró que al añadir mucílago de nopal se observa un incremento significativo de la resistencia a la compresión húmeda y seca, lo cual estar relacionado con una disminución de la porosidad; se ofrecen algunas relaciones del efecto del mucílago en el sólido analizado.

  16. Desplazamiento forzado y propiedad de la tierra en Antioquia, 1996-2004

    Directory of Open Access Journals (Sweden)

    Carlos Felipe Gaviria

    2007-06-01

    Full Text Available El desplazamiento forzoso es un fenómeno mundial que ha acompañado crisis políticas y sociales, relacionado, además, con el dominio del territorio por parte de los grupos inmersos en el conflicto. En Colombia, este fenómeno social se ha incrementado en los últimos años, junto con problemas agrarios, sociales y productivos. El objetivo de este artículo es analizar la relación existente entre el desplazamiento forzado y los procesos de concentración de la tierra en Antioquia entre 1996-2004. Se encuentra que existe una relación positiva entre propiedad de la tierra y desplazamiento forzado; en especial en Urabá y Oriente, subregiones antioqueñas con la producción agrícola más importante.

  17. Soil-water retention curve and beginning of monitoring in Tierra Blanca Joven (TBJ)

    OpenAIRE

    Chávez, José A.; López, Reynaldo; Kopecky, Lubomir; Landaverde, José

    2011-01-01

    In El Salvador during the rainy season or when major earthquakes occur, the areas covered by the volcanic tephras Tierra Blanca Joven (TBJ) suffer mass movements, liquefaction and erosion; causing important en- vironmental, social and economic losses. To start the characterization of these unsaturated soils, suction values of a fall unit of TBJ were obtained using pressure plate, centrifuge and filter paper to build a Soil-Water Retention Curve. The use of this curve into finite elements soft...

  18. La adecuación de tierras en el departamento de Antioquia.

    Directory of Open Access Journals (Sweden)

    Arango T. Julio César

    1999-06-01

    Full Text Available Los programas estatales de adecuación de tierras en Colombia comenzaron a partir de la década del 50, durante la cual se emprendió la construcción de infraestructuras básicas para el riego, el drenaje y el control de inundaciones. Las inversiones efectuadas por distintas entidades que en el país han tenido que ver con el Sector de la Adecuación de Tierras han sido cuantiosas y con ellas, se beneficiaron durante muchos años, los agricultores situados en distintas zonas planas de los departamentos del Tolima, Boyacá, Magdalena, Valle del Cauca entre otros. Antioquia durante este mismo tiempo, no se favoreció de esos recursos, por la carencia de políticas estatales en el Sector de la Adecuación de Tierras, solamente a partir de 1983, con el montaje por parte del HIMAT del Programa Nacional de Pequeña Irrigación, comienzan a solucionarse los problemas de manejo del agua para el riego de los cultivos en distintas veredas de Antioquia. Hoy se dispone de 29 distritos de riego en pequeña escala, los cuales corresponden a una superficie total de 3.759 ha, en las cuales, se benefician 1.510 familias campesinas.

  19. Las Tierras Indígenas en la Ley 19.253

    Directory of Open Access Journals (Sweden)

    Jaime López Allendes

    Full Text Available Desde el año 1993 rige en Chile una ley que reconoce a las étnias indígenas y señala que la tierra es para estas el fundamento principal de sus existencia y de su cultura. Tal declaración del legislador chileno es el basamento donde se levanta un régimen jurídico especial. Si bien con anterioridad se habían dictado varias leyes que regían las tierras indígenas, aquellas tuvieron por objeto, primero la radicación de los indígenas en comunidades, y luego la división para el ingreso de tales inmuebles al régimen común de propiedad prinvada, y más tarde al mercado. La mayor innovación de la ley en comento se refiere a que reconoce el valor de la tierra como hábitat cultural, y no como una nueva mercancía.

  20. The potential role of earthworms in toxicity assessment of terrestrial hazardous waste sites

    Energy Technology Data Exchange (ETDEWEB)

    Goven, A.J.; Fitzpatrick, L.C. [Univ. of North Texas, Denton, TX (United States); Venables, B.J. [TRAC Labs., Inc., Denton, TX (United States)

    1994-12-31

    Understanding the toxic potential and mechanisms of action of environmental xenobiotics is fundamental for assessing risk to public and environmental health. Current established protocols with earthworms focus primarily on defining the lethal effects of chemicals associated with soil contamination. Development of sublethal assays, until recently, has been largely ignored. Here the authors develop rationale for use of earthworms as a model organism for comprehensive assessment of risks to higher wildlife from contaminated soils and hazardous waste sites. They present a panel of lethal (LC/LD50`s) and sublethal measurement endpoint biomarkers, developed within the framework of the National Toxicology Program`s tiered immunotoxicity protocol for mice and according to published criteria for good measurement endpoints, that represent sensitive phylogenetically-conserved processes. Specifically the authors discuss immunosuppressive effects of terrestrial heavy metal and organic contamination on the innate, nonspecific and specific immune responses of earthworm, Lumbricus terrestris, coelomocytes in terms of total and differential cell counts, lysozyme activity, nitroblue tetrazolium dye reduction, phagocytic activity and secretary rosette formation. Findings indicate that sensitive phylogenetically conserved immune responses present in invertebrates can be used to assess or predict risk to wildlife from contaminated soils.

  1. Terrestrial Analogs to Mars

    Science.gov (United States)

    Farr, T. G.; Arcone, S.; Arvidson, R. W.; Baker, V.; Barlow, N. G.; Beaty, D.; Bell, M. S.; Blankenship, D. D.; Bridges, N.; Briggs, G.; Bulmer, M.; Carsey, F.; Clifford, S. M.; Craddock, R. A.; Dickerson, P. W.; Duxbury, N.; Galford, G. L.; Garvin, J.; Grant, J.; Green, J. R.; Gregg, T. K. P.; Guinness, E.; Hansen, V. L.; Hecht, M. H.; Holt, J.; Howard, A.; Keszthelyi, L. P.; Lee, P.; Lanagan, P. D.; Lentz, R. C. F.; Leverington, D. W.; Marinangeli, L.; Moersch, J. E.; Morris-Smith, P. A.; Mouginis-Mark, P.; Olhoeft, G. R.; Ori, G. G.; Paillou, P.; Reilly, J. F., II; Rice, J. W., Jr.; Robinson, C. A.; Sheridan, M.; Snook, K.; Thomson, B. J.; Watson, K.; Williams, K.; Yoshikawa, K.

    2002-08-01

    It is well recognized that interpretations of Mars must begin with the Earth as a reference. The most successful comparisons have focused on understanding geologic processes on the Earth well enough to extrapolate to Mars' environment. Several facets of terrestrial analog studies have been pursued and are continuing. These studies include field workshops, characterization of terrestrial analog sites, instrument tests, laboratory measurements (including analysis of Martian meteorites), and computer and laboratory modeling. The combination of all these activities allows scientists to constrain the processes operating in specific terrestrial environments and extrapolate how similar processes could affect Mars. The Terrestrial Analogs for Mars Community Panel has considered the following two key questions: (1) How do terrestrial analog studies tie in to the Mars Exploration Payload Assessment Group science questions about life, past climate, and geologic evolution of Mars, and (2) How can future instrumentation be used to address these questions. The panel has considered the issues of data collection, value of field workshops, data archiving, laboratory measurements and modeling, human exploration issues, association with other areas of solar system exploration, and education and public outreach activities.

  2. TECNOLOGÍAS DE TRATAMIENTO PARA LA TIERRA FULLER CONTAMINADA CON ACEITE DIELÉCTRICO

    Directory of Open Access Journals (Sweden)

    Óscar Darío Beltrán Pérez

    Full Text Available Desde hace algunos años en Colombia se vienen implementando convenios y normas para el adecuado manejo y disposición final de los residuos peligrosos, debido a que la cantidad generada cada vez va en aumento y al impacto adverso que estos residuos presentan en el ser humano y el medio ambiente. La tierra Fuller es un material inorgánico adsorbente (mineral de aluminosilicatos principalmente, utilizado en la industria eléctrica para la regeneración del aceite dieléctrico, un derivado del petróleo empleado como aislante eléctrico y térmico en los transformadores de potencia. Después del proceso de regeneración del aceite, el contenido de hidrocarburos del tipo poliaromáticos (o los PAH por sus siglas en inglés que presenta la tierra Fuller la convierten en un residuo peligroso que requiere de un adecuado tratamiento, para que reduzca su contaminación y permita su reutilización o segura disposición final en un relleno sanitario. Por esto, en este artículo se revisan las tecnologías disponibles para el tratamiento de este tipo de residuo peligroso (tierra Fuller contaminada con aceite dieléctrico, dividiendo los tratamientos en dos corrientes, las tecnologías fisicoquímicas y las biológicas, explorando las alternativas más apropiadas y eficientes para su tratamiento. La escasa información acerca de los tratamientos existentes para la tierra Fuller contaminada con aceite dieléctrico han orientado la revisión en términos de las tecnologías implementadas en suelos contaminados con hidrocarburos siendo válida la analogía debido a las similares características físicas que presenta la tierra Fuller con respecto a un suelo de bajo contenido de carbono.

  3. Can plastic bag derived-microplastics act as vectors for metal exposure in terrestrial invertebrates?

    Science.gov (United States)

    E Hodson, Mark; Duffus-Hodson, Calum A.; Prendergast-Miller, Miranda; Thorpe, Karen

    2017-04-01

    Microplastics are widely reported contaminants in marine and freshwater ecosystems and studies have shown that they can be ingested by aquatic organisms and lead to potential negative effects on health. The effects can arise from the physical effects of the plastics (e.g. food displacement and blockages of the digestive tract) and from their potential to adsorb contaminants, primarily organic compounds, resulting in an increased exposure of the organism to toxic contaminants. Studies are beginning to emerge that also show a high abundance of microplastics in the terrestrial environment but there remains a lack of data on the impacts of these terrestrial microplastics or their interaction with other terrestrial pollutants. We conducted Zn adsorption experiments using HDPE microplastics, derived from plastic bags. Zinc adsorption to microplastics was similar to that observed in soils, but in the presence of both soil and microplastics, preferential adsorption onto the soil was observed. In desorption experiments, desorption of Zn from microplastics and soils was minimal (earthworm guts desorption of 40 - 60% was observed for the microplastics compared to 2 - 15 % for the soils. In earthworm exposure experiments Lumbricus terrestris earthworms cultivated in soils containing 0.35% by mass of Zn-bearing plastic (236 - 4505 mg kg-1) ingested the microplastics with no evidence for either preferential feeding or avoidance. There was no evidence for an accumulation of the microplastics in the earthworm gut or for signs of toxicity. Our experiments demonstrate that earthworms will ingest microplastics and that microplastics can adsorb metals and act as vectors for metal exposure in soil invertebrates. However, for Zn, the risk associated with this exposure appears to be minimal.

  4. Mechanisms of carbacholine and GABA action on resting membrane potential and Na+/K+-ATPase of Lumbricus terrestris body wall muscles

    Czech Academy of Sciences Publication Activity Database

    Volkov, E. M.; Nurullin, L. F.; Volkov, M. E.; Nikolsky, E. E.; Vyskočil, František

    2011-01-01

    Roč. 158, č. 4 (2011), s. 520-524 ISSN 1095-6433 R&D Projects: GA AV ČR(CZ) IAA500110905; GA ČR GA202/09/0806 Institutional research plan: CEZ:AV0Z50110509 Keywords : GABA * acetylcholine * atropine Subject RIV: ED - Physiology Impact factor: 2.235, year: 2011

  5. Terrestrial Gravity Fluctuations

    Directory of Open Access Journals (Sweden)

    Jan Harms

    2015-12-01

    Full Text Available Different forms of fluctuations of the terrestrial gravity field are observed by gravity experiments. For example, atmospheric pressure fluctuations generate a gravity-noise foreground in measurements with super-conducting gravimeters. Gravity changes caused by high-magnitude earthquakes have been detected with the satellite gravity experiment GRACE, and we expect high-frequency terrestrial gravity fluctuations produced by ambient seismic fields to limit the sensitivity of ground-based gravitational-wave (GW detectors. Accordingly, terrestrial gravity fluctuations are considered noise and signal depending on the experiment. Here, we will focus on ground-based gravimetry. This field is rapidly progressing through the development of GW detectors. The technology is pushed to its current limits in the advanced generation of the LIGO and Virgo detectors, targeting gravity strain sensitivities better than 10^–23 Hz^–1/2 above a few tens of a Hz. Alternative designs for GW detectors evolving from traditional gravity gradiometers such as torsion bars, atom interferometers, and superconducting gradiometers are currently being developed to extend the detection band to frequencies below 1 Hz. The goal of this article is to provide the analytical framework to describe terrestrial gravity perturbations in these experiments. Models of terrestrial gravity perturbations related to seismic fields, atmospheric disturbances, and vibrating, rotating or moving objects, are derived and analyzed. The models are then used to evaluate passive and active gravity noise mitigation strategies in GW detectors, or alternatively, to describe their potential use in geophysics. The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our

  6. Terrestrial Gravity Fluctuations

    Science.gov (United States)

    Harms, Jan

    2015-12-01

    Different forms of fluctuations of the terrestrial gravity field are observed by gravity experiments. For example, atmospheric pressure fluctuations generate a gravity-noise foreground in measurements with super-conducting gravimeters. Gravity changes caused by high-magnitude earthquakes have been detected with the satellite gravity experiment GRACE, and we expect high-frequency terrestrial gravity fluctuations produced by ambient seismic fields to limit the sensitivity of ground-based gravitational-wave (GW) detectors. Accordingly, terrestrial gravity fluctuations are considered noise and signal depending on the experiment. Here, we will focus on ground-based gravimetry. This field is rapidly progressing through the development of GW detectors. The technology is pushed to its current limits in the advanced generation of the LIGO and Virgo detectors, targeting gravity strain sensitivities better than 10-23 Hz-1/2 above a few tens of a Hz. Alternative designs for GW detectors evolving from traditional gravity gradiometers such as torsion bars, atom interferometers, and superconducting gradiometers are currently being developed to extend the detection band to frequencies below 1 Hz. The goal of this article is to provide the analytical framework to describe terrestrial gravity perturbations in these experiments. Models of terrestrial gravity perturbations related to seismic fields, atmospheric disturbances, and vibrating, rotating or moving objects, are derived and analyzed. The models are then used to evaluate passive and active gravity noise mitigation strategies in GW detectors, or alternatively, to describe their potential use in geophysics. The article reviews the current state of the field, and also presents new analyses especially with respect to the impact of seismic scattering on gravity perturbations, active gravity noise cancellation, and time-domain models of gravity perturbations from atmospheric and seismic point sources. Our understanding of

  7. Terrestrial and extraterrestrial fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Heymann, D.; Jenneskens, L.W.; Jehlicka, J; Koper, C.; Vlietstra, E. [Rice Univ, Houston, TX (United States). Dept. of Earth Science

    2003-07-01

    This paper reviews reports of occurrences of fullerenes in circumstellar media, interstellar media, meteorites, interplanetary dust particles (IDPs), lunar rocks, hard terrestrial rocks from Shunga (Russia), Sudbury (Canada) and Mitov (Czech Republic), coal, terrestrial sediments from the Cretaceous-Tertiary-Boundary and Pennian-Triassic-Boundary, fulgurite, ink sticks, dinosaur eggs, and a tree char. The occurrences are discussed in the context of known and postulated processes of fullerene formation, including the suggestion that some natural fullerenes might have formed from biological (algal) remains.

  8. The terrestrial silica pump.

    Directory of Open Access Journals (Sweden)

    Joanna C Carey

    Full Text Available Silicon (Si cycling controls atmospheric CO(2 concentrations and thus, the global climate, through three well-recognized means: chemical weathering of mineral silicates, occlusion of carbon (C to soil phytoliths, and the oceanic biological Si pump. In the latter, oceanic diatoms directly sequester 25.8 Gton C yr(-1, accounting for 43% of the total oceanic net primary production (NPP. However, another important link between C and Si cycling remains largely ignored, specifically the role of Si in terrestrial NPP. Here we show that 55% of terrestrial NPP (33 Gton C yr(-1 is due to active Si-accumulating vegetation, on par with the amount of C sequestered annually via marine diatoms. Our results suggest that similar to oceanic diatoms, the biological Si cycle of land plants also controls atmospheric CO(2 levels. In addition, we provide the first estimates of Si fixed in terrestrial vegetation by major global biome type, highlighting the ecosystems of most dynamic Si fixation. Projected global land use change will convert forests to agricultural lands, increasing the fixation of Si by land plants, and the magnitude of the terrestrial Si pump.

  9. Radionuclides in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Bocock, K.L.

    1981-01-01

    This report summarizes information on the distribution and movement of radionuclides in semi-natural terrestrial ecosystems in north-west England with particular emphasis on inputs to, and outputs from ecosystems; on plant and soil aspects; and on radionuclides in fallout and in discharges by the nuclear industry. (author)

  10. Histories of terrestrial planets

    International Nuclear Information System (INIS)

    Benes, K.

    1981-01-01

    The uneven historical development of terrestrial planets - Mercury, Venus, Earth, Moon and Mars - is probably due to the differences in their size, weight and rotational dynamics in association with the internal planet structure, their distance from the Sun, etc. A systematic study of extraterrestrial planets showed that the time span of internal activity was not the same for all bodies. It is assumed that the initial history of all terrestrial planets was marked with catastrophic events connected with the overall dynamic development of the solar system. In view of the fact that the cores of small terrestrial bodies cooled quicker, their geological development almost stagnated after two or three thousand million years. This is what probably happened to the Mercury and the Moon as well as the Mars. Therefore, traces of previous catastrophic events were preserved on the surface of the planets. On the other hand, the Earth is the most metamorphosed terrestrial planet and compared to the other planets appears to be atypical. Its biosphere is significantly developed as well as the other shell components, its hydrosphere and atmosphere, and its crust is considerably differentiated. (J.P.)

  11. Terrestrial planet formation.

    Science.gov (United States)

    Righter, K; O'Brien, D P

    2011-11-29

    Advances in our understanding of terrestrial planet formation have come from a multidisciplinary approach. Studies of the ages and compositions of primitive meteorites with compositions similar to the Sun have helped to constrain the nature of the building blocks of planets. This information helps to guide numerical models for the three stages of planet formation from dust to planetesimals (~10(6) y), followed by planetesimals to embryos (lunar to Mars-sized objects; few 10(6) y), and finally embryos to planets (10(7)-10(8) y). Defining the role of turbulence in the early nebula is a key to understanding the growth of solids larger than meter size. The initiation of runaway growth of embryos from planetesimals ultimately leads to the growth of large terrestrial planets via large impacts. Dynamical models can produce inner Solar System configurations that closely resemble our Solar System, especially when the orbital effects of large planets (Jupiter and Saturn) and damping mechanisms, such as gas drag, are included. Experimental studies of terrestrial planet interiors provide additional constraints on the conditions of differentiation and, therefore, origin. A more complete understanding of terrestrial planet formation might be possible via a combination of chemical and physical modeling, as well as obtaining samples and new geophysical data from other planets (Venus, Mars, or Mercury) and asteroids.

  12. Epidemiología de las lesiones por mordedura de perro en Tierra del Fuego, Argentina Epidemiology of dog bite lesions in Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Fabián Zanini

    2008-02-01

    Full Text Available La convivencia del hombre y el perro ha resultado en beneficios mutuos durante miles de años, si bien en el último tiempo han surgido una serie de inconvenientes donde las lesiones por mordeduras ocupan un lugar destacado. El objetivo del presente trabajo fue describir las características epidemiológicas de las lesiones por mordedura de perro ocurridas a lo largo de un año en Tierra del Fuego. Se realizó un estudio observacional descriptivo, transversal, de los pacientes que ingresaron con lesiones por mordedura de perro al Servicio de Guardia Clínica y Pediátrica de los Hospitales y Centros de Salud desde el 1/3/05 hasta el 1/3/06. Se confeccionaron 382 planillas. El 49.5% fueron niños resultando más afectado el grupo de 5-9 años (44.4%; IC95% 37.2-51.8. En adultos correspondió al grupo de 15-24 años (29.5%; IC95% 23.2-36.5. Se registraron más lesiones en varones (57.6% que en mujeres (42.4% (x² = 8.6, p= 0.003. En los meses primavera y verano se registró el 56.5% de las lesiones, en la vía pública el 72.8% de ellas. Los perros de tamaño grande causaron el 49.7% (IC95% 44.6-54.9 de las lesiones. El 89.8% de los ataques fueron causados por perros ajenos. El 55.8% (IC95% 50.6-60.8 se registró en miembros inferiores y el 11% (IC95% 8.1-14.7 en cabeza y cuello. Los datos obtenidos demuestran que en Tierra del Fuego las lesiones por mordedura de perro afectan en forma permanente la salud e impactan en la calidad de vida de la población.The coexistence between man and dog has resulted in mutual benefits during thousands of years, nevertheless some problems have recently arisen where bite injuries have an important role. The aim of this work was to describe the epidemiological characteristics of dog bite lesions which occurred during a year in Tierra del Fuego. A descriptive observational, transversal study of patients who were admitted with dog bite injuries to clinic and pediatric emergency services of hospitals and health

  13. Bioconversion of biomass residue from the cultivation of pea sprouts on spent Pleurotus sajor-caju compost employing Lumbricus rubellus

    Directory of Open Access Journals (Sweden)

    Azizi Abu Bakar

    2012-11-01

    Full Text Available Vermicomposting is a green technology for the purpose of nutrient enrichment from a variety of organic waste products. In this study, saw dust-based spent mushroom compost (SMC, an organic waste and biomass residue, was used as a medium for the cultivation of pea sprouts. After harvesting the pea sprouts, the growth medium was reused to culture earthworms, Lumbricus rubellus. The culturing activity was conducted for 50 days without any pre-composting or thermocomposting. Thus duration of vermicomposting process was shortened as opposed to previous work on vermicomposting of saw dust-based SMC (no amendment for 70 days. The culturing treatments were conducted in triplicate, including one treatment without earthworms as the control. The analysis showed that concentrations of macronutrients in vermicompost were higher compared to controls, in which N = 4.12%, P = 2.07% and K = 1.56%. The C:N ratio was 11.77, which indicates a stabilisation and maturity of the organic waste compost, compared with the C:N ratio for the control, which was 59.34. At the end of the experiment, increment of total biomass and number of earthworms were observed and no mortality was recorded. The results suggested that vermicomposting could be used as an environmentally valuable technology to convert saw dust used for mushroom and pea sprouts cultivation into vermicompost or bio-fertiliser by employing L. rubellus.

  14. La tierra comunal en Andalucía durante la Edad Moderna

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    Antonio Miguel BERNAL

    2009-12-01

    Full Text Available RESUMEN: A partir de la ambigüedad conceptual que define a las tierras comunales en Andalucía se estudian, para los siglos XV al XVIII, tres aspectos fundamentales: cómo se llega a formar la propiedad comunal; a través de qué mecanismos —jurídicos y económicos— se van reduciendo las tierras comunales a propiedad privada; y, por último, qué funcionalidad económica habían tenido los comunales en el contexto del sistema agrario andaluz. La escasa población andaluza en la Edad Moderna y la gran disponibilidad de tierras incultas favorecieron, en el inicio, la aparición de comunales, bajo diversas modalidades, si bien la presión señorial y de las oligarquías urbanas consiguieron privatizarlos; en tales procesos se fundamentan las luchas agrarias andaluzas.ABSTRACT: Taking into account the conceptual ambiguity defining communal lands in Andalusia, we studied three fundamental aspects with regard to the 15th- 18th centuries: how communal property was formed, the mechanisms (legal and economic that led to the converting of communal lands into prívate property and, finally, the economic functionality that communal lands had in the context of the Andalusian agricultural system. The sparse Andalusian population during the early modern age and the availability of a large quantity of uncultivated land favoured, at the beginning, the formation of different kinds of communal land, althought it was the pressure form the upper classes and the urban oligarchies that led to its privatization; such processes are the basis of Andalusian agricultural disputes.

  15. Mapa de usos potenciales de la tierra de Galicia. Una perspectiva arqueológica

    Directory of Open Access Journals (Sweden)

    Currás Refojos, Brais X.

    2014-06-01

    Full Text Available A digital version of the map of potential land use of Galicia is here presented, adapted to a reclassification of three types of potential land use, established using historical criteria. An analytical procedure is developed to select the land-types and the system used for their digitalisation. In the final part the map is used to critically revise the possibilities of using this record for territorial characterisation in archaeological research.La cartografía de usos potenciales de la tierra es una herramienta de gran utilidad en el estudio de las formas de poblamiento y su relación con la explotación de los recursos agrícolas desde el enfoque de la arqueología del paisaje. La digitalización de esta información permite su aplicación sistemática en el análisis del territorio mediante SIG. En este trabajo se presenta el Mapa de usos potenciales de la tierra de Galicia, reclasificado en tres tipos establecidos en función de criterios históricos. Se muestra el procedimiento analítico desarrollado para la selección y clasificación de los tipos de tierra y su sistema de digitalización. Se examina la validez de esta fuente para la investigación arqueológica de las formas agrícolas en la antigu.edad desde el punto de vista del análisis del territorio y se ofrece una visión crítica sobre sus ventajas y limitaciones.

  16. Gobernancia y gestión de la tierra. Institución comunal de uso y propiedad de la tierra en la Comunidad Campesina Vista Alegre–Yanahuaylla. Estudio de caso

    OpenAIRE

    Alvarez del Castillo, Juan Alex

    2003-01-01

    La compleja historia y desarrollo de la institución comunal de uso y propiedad de la tierra en las comunidades campesinas del Ande peruano hoy vuelven a tomar un nuevo rumbo. Los cambios recientes en las normas que la gobiernan, especialmente en la Nueva Ley de Tierras 26505, ponen en preocupación el destino que les espera a las comunidades campesinas y su medio ambiente. Las reflexiones presentadas en esta investigación, a partir de la percepción de los actores locales, muestran las posibles...

  17. [Tierra del Fuego: the scientific-political construction of exclusion and counter-image of the ideal city dweller].

    Science.gov (United States)

    Nacach, Gabriela

    2012-01-01

    Due to its late incorporation into the national State, the social, economic and political setting of the Argentine province Tierra del Fuego differed from that of the rest of the national territory. In the construction of dependent otherness, objectifications and representations were imposed by state-related and non-state-related institutions, among other agencies. In this context, the Salesian mission of La Candelaria and Ushuaia's Jail for recidivists stand out as spaces in which biopolitics was concretised. The native population and criminals in Tierra del Fuego were those to be subjugated. The thesis of the extinction of the Indian and the simultaneous exaltation of the criminal as the subject of progress identified the scientific and political mechanisms by which the exclusion of certain social groups (Tierra del Fuego's indigenous population) and the inclusion of others (criminals) were regulated.

  18. La tierra en la construcción de cerramientos cons materiales de reciclaje

    OpenAIRE

    Blanco Martín, Javier; Arias Madero, Javier

    2014-01-01

    El material más sostenible en construcción, es aquel que necesita menos manipulación tanto industrial como humana en su utilización y que se encuentra lo más cerca posible de la obra. Cuanto menos se manipula y menos hay que transportarlo, menos energía se consume, menos residuos se generan y menos emisiones de CO2 a la atmosfera se desprenden. En este sentido la utilización de la tierra cruda obtenida de modo local, como material constructivo, se sitúa en la...

  19. Culturas de protesta y violencia de los campesinos de Tierra de Campos (1900-1923)

    OpenAIRE

    Redondo Cardeñoso, Jesús Ángel

    2010-01-01

    El texto presentado es un estudio de las distintas manifestaciones de protesta y acciones violentas que ejecutó el campesinado de la comarca castellano-leonesa de Tierra de Campos, durante las primeras décadas del siglo XX. En este sentido el texto se divide en dos partes: la primera dedicada al estudio de la protesta; y la segunda dedicada al estudio de la violencia. La primera parte, a su vez, se divide en otras dos, una dedicada al análisis de las distintas expresiones de protesta de carác...

  20. Las normativas de construcción con tierra en el mundo

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    Cid, J.

    2011-09-01

    Full Text Available For centuries, earth has been used as a construction material. Nevertheless, the normative in this matter is very scattered, and in the most developed countries, carrying out a construction with this material implies a variety of technical and legal problems. This article analyzes, in an international level, the normative panorama about constructions with earth, analyzing fifty five standards and regulations of countries all around the five continents; these represent the state of art that normalizes the earth as a construction material. It is a study indexed on the actual procedures and regulations developed by the national organisms of normalization or correspondent authorities. The standards and the organisms that produce them appear, analyzing the structure and the content of each one. We have studied and analyzed the most relevant aspects, such as stabilization, soil selections, the requisites of the products and the existent test, comparing the diverse normative. The knowledge from this study could be very useful for the development of future standards and as a reference for architects and engineers that work with earth.

    La tierra ha sido utilizada como material de construcción desde hace siglos. No obstante, la normativa al respecto está muy dispersa, y en la mayoría de países desarrollados surgen numerosos problemas técnicos y legales para llevar a cabo una construcción con este material. Este artículo estudia el panorama normativo para las construcciones con tierra cruda a nivel internacional, analizando cincuenta y cinco normas y reglamentos de países repartidos por los cinco continentes, que representan el estado del arte de la normalización de la tierra cruda como material de construcción. Es un estudio referenciado sobre las normas y reglamentos vigentes desarrollados por los organismos nacionales de normalización o autoridades correspondientes. Se presentan las normativas y los organismos que las emiten

  1. El surgimiento del Orden Internacional Moderno según Tierra y Mar de Carl Schmitt

    OpenAIRE

    Solano Palacio, Carlos Alberto

    2014-01-01

    El propósito de esta disertación es rescatar las interpretaciones de Tierra y Mar en lo que se refiere al surgimiento del Orden Internacional Moderno, con el objetivo de explicar la percepción de los acontecimientos por parte de Carl Schmitt y su aporte filosófico-jurídico a la comprensión de la historia y teoría de las Relaciones Internacionales. La particularidad de esta obra de Schmitt es su estilo profundo: la variedad y amplitud de temas que abarca, que contrasta con la brevedad del tex...

  2. An ecological basis for Nothofagus pumilio Forest management in Tierra del Fuego

    OpenAIRE

    Richter, Laura; Frangi, Jorge Luis

    1992-01-01

    Tradicionalmente en la Argentina, la ecología forestal y la silvicultura han marchado en general por caminos separados. La información ecológica apropiada puede ser aprovechada para un mejor manejo del bosque. La especie nativa Nothofagus pumilio (n.v. lenga) y los bosques que forma en la Tierra del Fuego poseen características biológicas y ecológicas favorables y desfavorables para la producción de madera que pueden diferir si son otros los objetivos del manejo. Estas características estruct...

  3. Working group 4: Terrestrial

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    A working group at a Canada/USA symposium on climate change and the Arctic identified major concerns and issues related to terrestrial resources. The group examined the need for, and the means of, involving resource managers and users at local and territorial levels in the process of identifying and examining the impacts and consequences of climatic change. Climatic change will be important to the Arctic because of the magnitude of the change projected for northern latitudes; the apparent sensitivity of its terrestrial ecosystems, natural resources, and human support systems; and the dependence of the social, cultural, and economic welfare of Arctic communities, businesses, and industries on the health and quality of their environment. Impacts of climatic change on the physical, biological, and associated socio-economic environment are outlined. Gaps in knowledge needed to quantify these impacts are listed along with their relationships with resource management. Finally, potential actions for response and adaptation are presented

  4. Phytopharmacology of Tribulus terrestris.

    Science.gov (United States)

    Shahid, M; Riaz, M; Talpur, M M A; Pirzada, T

    2016-01-01

    Tribulus terrestris is an annual herb which belongs to the Zygophyllaceae family. This plant has been used in traditional medicine for the treatment of various diseases for hundreds of decades. The main active phytoconstituents of this plant include flavonoids, alkaloids, saponins, lignin, amides, and glycosides. The plant parts have different pharmacological activities including aphrodisiac, antiinflammatory, antimicrobial and antioxidant potential. T. terrestris is most often used for infertility and loss of libido. It has potential application as immunomodulatory, hepatoprotective, hypolipidemic, anthelmintic and anticarcinogenic activities. The aim of the present article is to create a database for further investigation of the phytopharmacological properties of this plant to promote research. This study will definitely help to confirm its traditional use along with its value-added utility, eventually leading to higher revenues from the plant.

  5. Tierras, montes y aguas: Apuntes sobre energía, medio ambiente y justicia en las Américas

    OpenAIRE

    Soluri, John

    2012-01-01

    Resumen El título de este ensayo adopta las palabras del Plan de Ayala (1911) por medio del cual las fuerzas de Emiliano Zapata declararon su concepto de justicia durante la Revolución Mexicana. Desde la revolución hasta la actualidad, distintos historiadores se han dedicado al estudio de conflictos sobre la tierra en América Latina, pero han prestado mucho menos atención a la problemática de las aguas y montes.1 No cabe duda que la tierra ha sido al centro de muchos conflictos históricos y ...

  6. Terrestrial plant methane production

    DEFF Research Database (Denmark)

    Mikkelsen, Teis Nørgaard; Bruhn, Dan; Møller, Ian M.

    We evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants. We conclude that the phenomenon is true. Four stimulating factors have been observed to induce aerobic plant CH4 production, i.e. cutting injuries, increasing temperature...... the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

  7. Ecohydrological features of some contrasting mires in Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    A. Grootjans

    2010-01-01

    Full Text Available In November 2005, Tierra del Fuego (Argentina hosted the biennial conference and field excursion of the International Mire Conservation Group (IMCG. The group considered the vegetation, hydrology, peat stratigraphy and possible management options for about 20 mires which were visited during a seven-day excursion. We report here some field observations and measurements of electrical conductivity (EC25 in five mires which have been selected to encompass the most important ecohydrological features of the mires of Tierra del Fuego. Existing and new data on landscape topography and vegetation were combined in three-dimensional drawings. These drawings are actually conceptual models which could underpin further ecohydrological research, and proved to be very useful as a basis for discussions amongst conference participants about possible ecohydrological relationships. The mires that were studied developed under a wide range of climatic conditions and included fens and bogs. The bogs typically developed from lakes or fens and most are now dominated by Sphagnum magellanicum. This species forms large hummocks, and can invade weakly-buffered fens. Most of the mires were well preserved, but effects of human impact - such as road building and peat extraction - were also noticeable.

  8. State of knowledge of the Corallinales (Rhodophyta of Tierra del Fuego and the Antarctic Peninsula

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    María Laura Mendoza

    1999-12-01

    Full Text Available Corallinales (Rhodophyta in Tierra del Fuego are abundant, with 9 genera, 17 species and 1 subspecies. Pseudolithophyllum with 1 species (P. fueguianum, which represents 35.8% of the coralline algae, is dominant. The genera Parahydrolithon with 4 species (P. consociatum, P. discoideum, P. falklandicum, P. subantarcticum and 20%, Lithothamnion with 3 species (Lt. heterocladum, Lt. rugosum, Lt. granuliferum and 17.5%, and Synarthrophyton with 3 species (S. neglectum, S. patena, S. schmitzii and 12% share are abundant. Clathromorphum with 4 species (Cl. annulatum, Cl. lemoineanum, Cl. obtectulum, Cl. Variabile and a share of 5.8%, and Mesophyllum with 1 species (M. fueguianum and a share of 4.9% are frequent. The remaining three genera, Bossiella with 1 subspecies (B. orbigniana ssp. orbigniana, Corallina with 2 species (C. elongata, C. officinalis (1.1%, and Titanoderna with 1 species (T. conspectum (1% are scarce. C. officinalis is a cosmopolitan, and the other geniculate corallines are found in both hemispheres, whereas the crustose coralline occur only in the southern hemisphere. The characteristic vertical distribution of the species in the intertidal and subtidal zone of Tierra del Fuego is given. The Corallinales in the Antarctic Region are poorly known and need further investigation.

  9. La industria textil en Tierra de Campos afines de la Edad Media

    Directory of Open Access Journals (Sweden)

    Hipólito Rafael OLIVA HERRER

    2009-12-01

    Full Text Available RESUMEN: El presente articulo trata de analizar el desarrollo de la industria textil rural en la región de Tierra de Campos, en torno al tradicional centro de producción textil de Palencia, a fines del XV y comienzos del XVI. La producción en el entorno rural conoció un amplio desarrollo basado en la producción de paños de calidad media-baja destinados al consumo interno, y dio lugar a formas organizativas complejas que se constituyeron en una alternativa frente al sistema gremial imperante en la urbe palentina, implicando intereses de un amplio espectro de grupos sociales.ABSTRACT: The present article aims to analyze the spreading of the rural textile industry in the region of Tierra de Campos in the late fifteenth and the early sixteenth centuries, around the traditional productive centre of Palencia. Here rural clothing experienced an important development based on the production of low and medium quality cloth under a putting-out system directed to interregional trade. The interests around rural industry involved a wide range of social groups, giving rise to complex organization forms and arising as an alternative to the traditional gudd stmcture.

  10. Isolation of Sphaerotilus-Leptothrix strains from iron bacteria communities in Tierra del Fuego wetlands.

    Science.gov (United States)

    Schmidt, Bertram; Sánchez, Leandro A; Fretschner, Till; Kreps, Gastón; Ferrero, Marcela A; Siñeriz, Faustino; Szewzyk, Ulrich

    2014-11-01

    Sheath-forming iron- and manganese-depositing bacteria belonging to the Sphaerotilus-Leptothrix group (SLG) are widespread in natural and artificial water systems. Known requirements for their growth include the presence of organic substrates and molecular oxygen. High concentrations of reduced iron or manganese, although not necessary for most species, make their growth a noticeable phenomenon. Such microbial communities have been studied mostly in the Northern Hemisphere. Here, we present descriptions of diverse ochre-depositing microbial communities in Tierra del Fuego, Argentina, using a combined approach of microscopical examination, clone library construction and cultivation focused on SLG bacteria. To date, only few SLG type strains are available. The present work increases the number and diversity of cultivated SLG bacteria by obtaining isolates from biofilms and sediment samples of wetlands in Tierra del Fuego. Thirty isolates were selected based on morphological features such as sheath formation and iron/manganese deposition. Five operational taxonomic units (OTUs) were deduced. Sequencing of 16S rRNA genes showed that one OTU is identical to the Leptothrix mobilis Feox-1(T) -sequence while the four remaining OTUs show similarity values related to previously described type strains. Similarity values ranged from 96.5% to 98.8%, indicating possible new species and subspecies. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  11. Transcriptome profiling of developmental and xenobiotic responses in a keystone soil animal, the oligochaete annelid Lumbricus rubellus

    Directory of Open Access Journals (Sweden)

    Morgan A John

    2008-06-01

    Full Text Available Abstract Background Natural contamination and anthropogenic pollution of soils are likely to be major determinants of functioning and survival of keystone invertebrate taxa. Soil animals will have both evolutionary adaptation and genetically programmed responses to these toxic chemicals, but mechanistic understanding of such is sparse. The clitellate annelid Lumbricus rubellus is a model organism for soil health testing, but genetic data have been lacking. Results We generated a 17,000 sequence expressed sequence tag dataset, defining ~8,100 different putative genes, and built an 8,000-element transcriptome microarray for L. rubellus. Strikingly, less than half the putative genes (43% were assigned annotations from the gene ontology (GO system; this reflects the phylogenetic uniqueness of earthworms compared to the well-annotated model animals. The microarray was used to identify adult- and juvenile-specific transcript profiles in untreated animals and to determine dose-response transcription profiles following exposure to three xenobiotics from different chemical classes: inorganic (the metal cadmium, organic (the polycyclic aromatic hydrocarbon fluoranthene, and agrochemical (the herbicide atrazine. Analysis of these profiles revealed compound-specific fingerprints which identify the molecular responses of this annelid to each contaminant. The data and analyses are available in an integrated database, LumbriBASE. Conclusion L. rubellus has a complex response to contaminant exposure, but this can be efficiently analysed using molecular methods, revealing unique response profiles for different classes of effector. These profiles may assist in the development of novel monitoring or bioremediation protocols, as well as in understanding the ecosystem effects of exposure.

  12. EVALUACIÓN DEL PATRIMONIO ARQUEOLÓGICO EN LA COSTA DEL LAGO FAGNANO, PARQUE NACIONAL TIERRA DEL FUEGO, ARGENTINA (Assessment of the Archaeological Heritage on the Coast of Lake Fagnano, Tierra del Fuego National Park, Argentina

    Directory of Open Access Journals (Sweden)

    María Celina Alvarez Soncini

    2017-09-01

    Full Text Available El presente trabajo se refiere a las prospecciones y análisis de materiales recuperados en la costa sur del lago Fagnano, dentro del Parque Nacional Tierra del Fuego, durante las campañas del año 2016. Los trabajos de campo permitieron efectuar un registro del patrimonio cultural del área prospectada, en la que se detectaron importantes evidencias arqueológicas. Los resultados de esta primera aproximación permiten ampliar nuestros conocimientos sobre la dinámica de ocupación humana en el área central de la Isla Grande de Tierra del Fuego, al incorporar una nueva zona en el tramo occidental del lago Fagnano. ENGLISH: This article presents the results of surveys and analysis of archaeological materials discovered on the southern coast of Lake Fagnano within the Tierra del Fuego National Park, during the 2016 field season. The fieldwork allowed us to register cultural heritage in the survey area in which important archaeological evidence was detected. The results of this first approach allow us to expand our knowledge about the dynamics of human occupation in the central region of the Great Island of Tierra del Fuego by incorporating a new zone in the western section of Lake Fagnano.

  13. Terrestrial Steering Group. 2014. Arctic Terrestrial Biodiversity Monitoring Plan

    DEFF Research Database (Denmark)

    Aastrup, Peter; Aronsson, Mora; Barry, Tom

    implementation of the Arctic Terrestrial Biodiversity Monitoring Plan for the next two years. Identify expert networks required for successful implementation of the plan. Identify key gaps and opportunities for the TSG related to plan implementation and identify near-term next steps to address gaps.......The Terrestrial Steering Group (TSG), has initiated the implementation phase of the CBMP Terrestrial Plan. The CBMP Terrestrial Steering Group, along with a set of invited experts (see Appendix A for a participants list), met in Iceland from February 25-27th to develop a three year work plan...... to guide implementation of the CBMP-Terrestrial Plan. This report describes the outcome of that workshop. The aim of the workshop was to develop a three year work plan to guide implementation of the CBMP-Terrestrial Plan. The participants were tasked with devising an approach to both (a) determine what...

  14. As-resistance in laboratory-reared F1, F2 and F3 generation offspring of the earthworm Lumbricus rubellus inhabiting an As-contaminated mine soil

    International Nuclear Information System (INIS)

    Langdon, C.J.; Morgan, A.J.; Charnock, J.M.; Semple, K.T.; Lowe, C.N.

    2009-01-01

    Previous studies provided no unequivocal evidence demonstrating that field populations of Lumbricus rubellus Hoffmeister (1843), exhibit genetically inherited resistance to As-toxicity. In this study F1, F2 and F3 generation offspring derived from adults inhabiting As-contaminated field soil were resistant when exposed to 2000 mg kg -1 sodium arsenate. The offspring of uncontaminated adults were not As-resistant. Cocoon viability was 80% for F1 and 82% for F2 offspring from As-contaminated adults and 59% in the F1 control population. High energy synchrotron analysis was used to determine whether ligand complexation of As differed in samples of: resistant mine-site adults, the resistant F1 and F2 offspring of the mine-site earthworms exposed to the LC 25 sodium arsenate (700 mg kg -1 ) of the F1 parental generation; and adult L. rubellus from an uncontaminated site exposed to LC 25 concentrations of sodium arsenate (50 mg kg -1 ). XANES and EXAFS indicated that As was present as a sulfur-coordinated species. - As-resistance in F1, F2 and F3 offspring of the earthworm Lumbricus rubellus.

  15. Tierra vacante y proceso de expansión urbana en las periferias del Partido de La Plata

    Directory of Open Access Journals (Sweden)

    Daniela Cortizo

    2017-12-01

    Full Text Available El objetivo del presente artículo es aportar una visión integral de la problemática de la tierra vacante en el Partido de La Plata, introduciendo variables de análisis que den cuenta de las características del proceso de expansión urbana en las periferias de la ciudad. La metodología adoptada identifica las tierras vacantes del caso de estudio, para analizarlas según dos variables: las intensidades y formas de ocupación del territorio dominantes, y el marco legal normativo que rige el uso potencial futuro de esas tierras. En función de este análisis, los resultados obtenidos sintetizan aspectos relevantes del actual proceso de expansión de las periferias urbanas, identificando las características del eje de crecimiento en donde se encuentran localizadas, en relación a las formas de ocupación del suelo y a las tierras vacantes intersticiales.

  16. Modelo matemático para la descripción de la transferencia de calor para tierra vertida

    Directory of Open Access Journals (Sweden)

    Edgardo Jonathan Suárez-Domínguez

    2014-01-01

    Full Text Available La arquitectura de tierra implica procesos constructivos sustentables ya que utiliza materiales vernáculos duraderos cuyos residuos son de bajo impacto al ambiente. La tierra vertida es una técnica a partir de la cual pueden tenerse muros resistentes dentro de la edificación de viviendas pero cuyas propiedades han sido poco evaluadas y representadas a partir de modelos. La transferencia de calor es una de las características más importantes cuando se edifica en zonas calurosas pues implica ciertos niveles de confort para los usuarios. El presente trabajo propone un modelo para determinar la difusividad térmica de tierra vertida con uso potencial para otras determinaciones a diversas temperaturas, algunas implicaciones también son presentadas. Se encontró que el coeficiente de difusividad térmica de muestras de tierra vertida fue de   4.319  10 8 m 2 s 1 , mientras que su calor específico es de 1.1030 kJkg-1K 1 .

  17. Taenia saginata Goeze, 1872 (Platyhelminthes: Cestoda: Taeniidae en un indígena de Tierra del Fuego, Chile

    Directory of Open Access Journals (Sweden)

    Eduardo I. Faúndez

    2015-06-01

    Full Text Available Se entrega el primer registro del céstodo Taenia saginata en un indígena de Tierra del Fuego (Patagonia chilena, correspondiente al año 1902. Se discute la importancia del registro y se entregan ilustraciones del ejemplar.

  18. Arctic Terrestrial Biodiversity Monitoring Plan

    DEFF Research Database (Denmark)

    Christensen, Tom; Payne, J.; Doyle, M.

    The Conservation of Arctic Flora and Fauna (CAFF), the biodiversity working group of the Arctic Council, established the Circumpolar Biodiversity Monitoring Program (CBMP) to address the need for coordinated and standardized monitoring of Arctic environments. The CBMP includes an international...... on developing and implementing long-term plans for monitoring the integrity of Arctic biomes: terrestrial, marine, freshwater, and coastal (under development) environments. The CBMP Terrestrial Expert Monitoring Group (CBMP-TEMG) has developed the Arctic Terrestrial Biodiversity Monitoring Plan (CBMP......-Terrestrial Plan/the Plan) as the framework for coordinated, long-term Arctic terrestrial biodiversity monitoring. The goal of the CBMP-Terrestrial Plan is to improve the collective ability of Arctic traditional knowledge (TK) holders, northern communities, and scientists to detect, understand and report on long...

  19. Respuesta transitoria de las puestas a tierra en la protección contra rayos. Software GTIERRAS

    Directory of Open Access Journals (Sweden)

    Héctor David Gómez Montoya

    2006-01-01

    Full Text Available Se usa un programa computacional desarrollado en Matlab (GTIERRAS que implementa un modelo de base electromagnética, para determinar la impedancia de puesta a tierra de configuraciones arbitrarias y su comportamiento ante excitaciones tipo impulso. Impedancia, corrientes y voltajes, u otras variables eléctricas de sistemas de puesta a tierra se pueden presentar en el dominio de la frecuencia o del tiempo usando la transformada rápida de Fourier. La base general del modelo considerado se usa para valorar no sólo sobretensiones por descargas atmosféricas, sino también, otros transitorios típicos asociados con problemas de compatibilidad electromagnética. Los resultados muestran la influencia de algunas variables en la respuesta del sistema de puesta a tierra y revelan algunas diferencias que se deben tener en cuenta cuando se aplican criterios basados en el desempeño a baja frecuencia, para esfuerzos impulsivos de puestas a tierra. Adicionalmente, se presentan ejemplos de cálculo y comparaciones con resultados de otros autores para ilustrar algunos comportamientos que de ninguna manera son evidentes. Se investiga además, el efecto de la geometría de los electrodos y la resistividad del suelo, así como del frente de onda y el número de puntos de inyección. También se presentan resultados de tensiones de contacto y de paso, así como, el estudio de un sistema de protección contra rayos como ampliación de las aplicaciones del modelo. Finalmente, se derivan algunas conclusiones útiles para el diseño de sistemas de puesta a tierra.

  20. Revestimientos y acabados superficiales en construcciones con tierra contemporáneas

    Directory of Open Access Journals (Sweden)

    Castilla, F. J.

    2011-09-01

    Full Text Available Earth construction is in increasing demand in some areas of building activity, which means a need for technical solutions to maintain and preserve the properties of earth walls. Like earth wall construction techniques themselves, materials used for rendering (plastering, painting, panelling, etc have evolved in a way that allows us to find formal solutions suitable for every architectural situation. This paper deals with the special features of each rendering technique available in contemporary construction, from renderings permitting earth wall textures and finish to be appreciated, to plasters from different materials. Special attention will be focused on clay plasters, which are more appreciated due to its natural characteristics and compatibility with the base wall. The explanations are supported by different examples of buildings where these techniques have been used during the last two decades.

    La creciente demanda para la construcción de muros de tierra en algunos ámbitos del sector de la edificación conlleva la necesidad de plantear soluciones constructivas que permitan el adecuado mantenimiento de las prestaciones de dichos muros. Al igual que las propias técnicas para la construcción de los muros, los materiales utilizados para su revestimiento y protección han evolucionado permitiendo una gran variedad de soluciones formales acordes a cada situación. En este artículo se pretende hacer una revisión sobre las particularidades de las diferentes posibilidades que se presentan en el panorama de la construcción actual: desde los revestimientos que permitan mantener a la vista los acabados de los muros de tierra a los revocos de distinta naturaleza, con especial incidencia en aquellos que utilizan la propia tierra como material base, siendo los más apropiados a priori por su natural compatibilidad con el soporte. La explicación se acompañará de ejemplos ilustrativos de la aplicación de dichas técnicas en edificios

  1. La tierra en armas de Dávalos-Serrano (o las armas del teatro

    Directory of Open Access Journals (Sweden)

    Marcela Beatriz Sosa

    2003-01-01

    Full Text Available La tierra en armas (1926 constituye un texto enigmático por diversas cuestiones, a pesar de su celebridad –es la obra teatral más famosa de la literatura salteña- y de su aparente transparencia al representar hechos históricos relativos a la gesta de Güemes. El primer enigma es el problema de la autoría, ya que La tierra en armas surge de la escritura en colaboración de Juan Carlos Dávalos y Ramón Serrano, pero en el momento de publicación del texto (1935 aparecerá en la portada sólo el nombre de Dávalos. El gesto editorial de borrar el nombre del segundo autor en esa primera publicación es decisivo para el futuro teatral de Serrano, quien desaparece posteriormente de la escena salteña. La segunda cuestión deriva de la categoría de teatro histórico a la cual pertenece La tierra en armas La ficcionalización de un personaje histórico implica plantear las complejas relaciones que se establecen entre discurso dramático y discurso histórico. Luego de trazar someramente la trayectoria épica de Güemes, se realiza una descripción de la acción dramática y de los fundamentales procedimientos discursivos, como el encadenamiento entre la intriga principal (histórica y la secundaria (sentimental, la mise en abyme de la leyenda de la flor del Ilolay y la visualización escénica del texto. La tercera cuestión incluye el contexto de producción, circulación y recepción del teatro de la época, así como el nivel ideológico, sin los cuales sería imposible postular una interpretación del texto de Dávalos y Serrano como estrategia individual y colectiva de afianzamiento de la identidad.

  2. Contaminant exposure in terrestrial vertebrates

    International Nuclear Information System (INIS)

    Smith, Philip N.; Cobb, George P.; Godard-Codding, Celine; Hoff, Dale; McMurry, Scott T.; Rainwater, Thomas R.; Reynolds, Kevin D.

    2007-01-01

    Here we review mechanisms and factors influencing contaminant exposure among terrestrial vertebrate wildlife. There exists a complex mixture of biotic and abiotic factors that dictate potential for contaminant exposure among terrestrial and semi-terrestrial vertebrates. Chemical fate and transport in the environment determine contaminant bioaccessibility. Species-specific natural history characteristics and behavioral traits then play significant roles in the likelihood that exposure pathways, from source to receptor, are complete. Detailed knowledge of natural history traits of receptors considered in conjunction with the knowledge of contaminant behavior and distribution on a site are critical when assessing and quantifying exposure. We review limitations in our understanding of elements of exposure and the unique aspects of exposure associated with terrestrial and semi-terrestrial taxa. We provide insight on taxa-specific traits that contribute, or limit exposure to, transport phenomenon that influence exposure throughout terrestrial systems, novel contaminants, bioavailability, exposure data analysis, and uncertainty associated with exposure in wildlife risk assessments. Lastly, we identify areas related to exposure among terrestrial and semi-terrestrial organisms that warrant additional research. - Both biotic and abiotic factors determine chemical exposure for terrestrial vertebrates

  3. Terrestrial Plume Impingement Testbed Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Masten Space Systems proposes to create a terrestrial plume impingement testbed for generating novel datasets for extraterrestrial robotic missions. This testbed...

  4. Terrestrial Carbon Cycle Variability.

    Science.gov (United States)

    Baldocchi, Dennis; Ryu, Youngryel; Keenan, Trevor

    2016-01-01

    A growing literature is reporting on how the terrestrial carbon cycle is experiencing year-to-year variability because of climate anomalies and trends caused by global change. As CO 2 concentration records in the atmosphere exceed 50 years and as satellite records reach over 30 years in length, we are becoming better able to address carbon cycle variability and trends. Here we review how variable the carbon cycle is, how large the trends in its gross and net fluxes are, and how well the signal can be separated from noise. We explore mechanisms that explain year-to-year variability and trends by deconstructing the global carbon budget. The CO 2 concentration record is detecting a significant increase in the seasonal amplitude between 1958 and now. Inferential methods provide a variety of explanations for this result, but a conclusive attribution remains elusive. Scientists have reported that this trend is a consequence of the greening of the biosphere, stronger northern latitude photosynthesis, more photosynthesis by semi-arid ecosystems, agriculture and the green revolution, tropical temperature anomalies, or increased winter respiration. At the global scale, variability in the terrestrial carbon cycle can be due to changes in constituent fluxes, gross primary productivity, plant respiration and heterotrophic (microbial) respiration, and losses due to fire, land use change, soil erosion, or harvesting. It remains controversial whether or not there is a significant trend in global primary productivity (due to rising CO 2 , temperature, nitrogen deposition, changing land use, and preponderance of wet and dry regions). The degree to which year-to-year variability in temperature and precipitation anomalies affect global primary productivity also remains uncertain. For perspective, interannual variability in global gross primary productivity is relatively small (on the order of 2 Pg-C y -1 ) with respect to a large and uncertain background (123 +/- 4 Pg-C y -1 ), and

  5. La tierra entre derecho y cultura indígena en Argentina

    Directory of Open Access Journals (Sweden)

    Marzia Rosti

    2009-12-01

    Full Text Available The paper considers the relationships between the indigenous peoples and the Argentinian State since the XIX century until 1994, when it was introduced in the Constitution the provision acknowledging to the indigenous peoples “la posesión y propiedad comunitarias de las tierras que tradicionalmente ocupan”, “la entrega de otras aptas y suficientes para el desarrollo humano” and granting them “la parcipación en la gestión referida a sus recursos naturales y a los demás intereses que los afecten” (art. 75, inc. 17. The paper describes then the issue concerning the claim for indigenous land – raised by the new constitutional provision – and focuses on some significant cases and the more recent jurisprudence on that issue.

  6. Parábola existencial de la primera Residencia en la Tierra

    Directory of Open Access Journals (Sweden)

    Eduardo Gómez

    1979-12-01

    Full Text Available Como sucede con muchos artistas, es el amor el que hace de Neruda un gran poeta. Su iniciación en la literatura universal data, sin duda, de los "Veinte poemas de amor y una canción desesperada" pero es a partír de "Residencia en la tierra" que logra afianzarse, en profundidad, como uno de los grandes poetas de la lengua castellana y uno de los más extraordinarios líricos de la historia de la literatura. En "Veinte poemas... ", el amor lo hace compenetrarse, estremecido, con la Naturaleza, lo desnuda de convenciones y prejuicios, lo embriaga de gozos dolorosos y le descubre todo el vasto mundo popular del drama sentim ental, depurado y abierto a la profundidad cósmica.

  7. RIESGOS CLIMÁTICOS EN LAS TIERRAS VALENCIANAS. INCIDENCIA EN LA ACTIVIDAD AGRARIA

    Directory of Open Access Journals (Sweden)

    Jorge Olcina Cantos

    1995-01-01

    Full Text Available La actividad agraria es el sector económico que, con mayor frecuencia, sufre los efectos de episodios atmosféricos excepcionales que ocasionan graves pérdi- das de cosecha y daños en campos de cultivo e infraestructura agraria (caminos, redes de riego. El campo valenciano no es ajeno a estos eventos, por lo demás condignos a sus condiciones climáticas (lluvias torrenciales, heladas, tormentas de granizo, temporales de viento y sequías, que precisan estudio de causas, consecuencias económicas y localización territorial de sectores de riesgo, para la posterior propuesta de medidas de actuación. La relación de prácticas de defensa puestas en práctica en tierras valencianas ante estos sucesos atmosféri- cos completa el presente estudio.

  8. Violence in Tierra Caliente: Inequality, Development and Education Rates in Drug War

    Directory of Open Access Journals (Sweden)

    Raúl Zepeda Gil

    2017-10-01

    Full Text Available The following article presents the effects of social and economic variables on the increment of violence in regional areas of Mexico, upon the intensification of drug prohibitions policies established by former President Felipe Calderon’s administration. This study involved using a data panel of homicides rates with firearms in 31 municipalities of the region of Tierra Caliente for the time period between 2006 to 2012. The results from the study help indicate that agroindustrial development, income inequality, and education rates have been effected in correlation with the increasing of homicidal rates. Also, based on the relevance of the inequality indicators of the study, it can be argued that there is a possible coincidence between the literature of civil wars and sociology of crime in that can be used to explain such cases of violence.

  9. Substations grounding systems design; Diseno de sistemas de conexion a tierra en subestaciones

    Energy Technology Data Exchange (ETDEWEB)

    Velazquez Sanchez, Raul [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1986-12-31

    The grounding systems have been the object of a great number of analytical and experimental studies in the past 15 years, that have given rise to research reports on the several aspects involved in this technique. In this work are briefly reviewed various aspects that is necessary to take into account for its design, analysis and put in operation. [Espanol] Los sistemas de conexion a tierra han sido objeto de gran cantidad de estudios analiticos y experimentales en los pasados quince anos, que han dado origen a informes de investigacion sobre los diversos aspectos que involucra esta tecnica. En este trabajo se revisan brevemente diversos aspectos que es necesario considerar para su diseno, analisis y puesta en operacion.

  10. El regreso de los judíos hispanos a Tierra Santa

    Directory of Open Access Journals (Sweden)

    Enrique Cantera Montenegro

    2004-01-01

    Full Text Available Tras un breve análisis acerca del lugar que la ciudad de Jerusalén y la Tierra Prometida ocupan en el judaismo y en la conciencia colectiva del pueblo judío, y del papel que la Ciudad Santa desempeña como meta de los peregrinos judíos, se estudian los movimientos de migración de los judíos hispanos hacia Palestina, a lo largo de la Edad Media y hasta el siglo XVII.After a brief analysis about the importance of Jerusalem and the Promised Land in the Judaism and in the collective consciousness of the Jewish people, and the role played by the Holy City as a destination for the Jewish pilgrims, the migration movements of the Spanish Jewish to Palestine are studied, along the Middle Ages, until the 17th century.

  11. Atmospheric electric discharges and grounding systems; Descargas atmosfericas y sistemas de conexion a tierra

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, Elena [ed.] [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

    1999-07-01

    In this article the work made by the Institute of Investigaciones Electricas (IIE), in the area of atmospheric electric discharges and grounding connections at Comision Federal de Electricidad (CFE) is presented. The work consisted of the revision of the procedures for the design of transmission lines and substations of CFE from which high indexes of interruptions are reported, from this, a program was defined that allowed to improve the existing designs in CFE. [Spanish] En este articulo se presenta el trabajo realizado por el Instituto de Investigaciones Electricas (IIE), en el area de descargas atmosfericas y conexiones a tierra en Comision Federal de Electricidad (CFE). El trabajo consistio en la revision de los procedimientos de diseno de las areas de transmision y subestaciones de la CFE para los que se reportan altos indices de salidas, a partir de esto se definio un programa que permitio mejorar los disenos existentes en la CFE.

  12. Guanaco’s diet and forage preferences in Nothofagus forest environments of Tierra del Fuego, Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Quinteros, C.P.; Bava, J.; Gobbi, M.E.; Defossé, G.E.

    2017-11-01

    Aim of study: Guanaco (Lama guanicoe Müller), is a South American native ungulate widely distributed in Patagonia, which in the island of Tierra del Fuego (TF), extends its habitat into Nothofagus spp. forests. Within these forests, guanacos consume lenga (Nothofagus pumilio) leaves and twigs, and other understory species. The aim of this work was to determine: 1) the spring and summer diet of free ranging guanacos, and 2) which plants, grown in the forest understory, guanacos do prefer, or avoid, in these seasons of great forage abundance. Area of study: Tierra del Fuego (Argentina), on three representative areas which combined Nothofagus forests and adjacent meadows (vegas). Material and Methods: uanacos’ diet was determined by comparing epidermal and non-epidermal plant fragments with micro-histological analyses of feces. The analysis was made from composite samples of fresh feces, collected at the seasons of maximum forage productivity (spring and summer). Main results: During spring, 48% of guanacos’ diet was composed of lenga leaves, 30% of grass-like species, 15% of grasses, and less than 7% of herbs, shrubs, and lichens. In summer, 40% of the diet was composed of grasses, 30% of lenga leaves, 25% of grass-like species and the rest corresponded to herbs, shrubs, and lichens. Within the forest understory, guanaco selected lenga leaves and twigs, grass species were consumed according to their availability (or sometimes rejected), while other herbs were not consumed at all. Research highlights: Guanacos’ consumption preference for lenga, even considering the high availability of other forages, could adversely affect forest regeneration.

  13. El antiguo cementerio de la mision de Río Grande, Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    García Laborde, Pamela

    2010-01-01

    Full Text Available En el marco del proceso de contacto interétnico ocurrido hacia fines del siglo XIX y principios del XX en Tierra del Fuego, lo acontecido específicamente en la misión salesiana La Candelaria (Rio Grande cobra relevancia por la variedad de registros y fuentes que dicho escenario ofrece. La aproximación historiográfica permitió generar información acerca de la presencia de tuberculosis como causa principal de muerte entre los aborígenes que vivieron en la misión y sobre la dieta, la actividad física y las condiciones en las que vivieron aquellos. Paralelamente tres campañas de excavación realizadas hasta el momento permitieron exhumar restos óseos humanos de once individuos integrantes de la comunidad Selk'nam del cementerio de la misión. El objetivo de este trabajo es presentar los primeros resultados sobre el relevamiento de patologías nutricionales-metabólicas e infecciosas surgidos de los trabajos de campo realizados por todo el equipo de investigación en dicho cementerio. Los resultados hallados muestran hasta el momento una alta frecuencia de indicadores de stress metabólico-nutricional, mayor a la observada en general en restos de aborígenes de Tierra del Fuego en otros contextos arqueológicos. Además, se observaron lesiones infecciosas inespecíficas que también están presentes en frecuencias altas en casos de tuberculosis

  14. Knowing for controlling: ecological effects of invasive vertebrates in Tierra del Fuego Conocer para controlar: efectos ecológicos de vertebrados invasores en Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    CLAUDIA A SILVA

    2008-03-01

    Full Text Available The Tierra del Fuego (TDF archipelago is recognized as part o the last places on Earth that may still be considered wild. However, this condition may be threatened by the large number of invasive species present on the archipelago. These species can have significant effects on the ecology of the invaded ecosystems, at the genetic as well as at population, community and ecosystem levels. The aim of this study is to, by a bibliographic review, systematize existing information on the ecological impacts these species would be having on the TDF archipelago and detect information gaps in order to orient future research and effective management programs on these species. We restricted our review to vertebrate, non-marine invaders. We determined which species have invaded TDF, described their impacts on the archipelago and evaluated their potential impacts; this last issue was determined by reviewing some of the impacts these species have had in other geographic areas. Our findings indicate that at least nine vertebrate species (Salmo trutta, Salvelinus fontinalis, Oncorhynchus mykiss, Castor canadensis, Ondatra zibethicus, Oryctolagus cuniculus, Pseudalopex griseus, Mustela vison and Sus seroja have wild populations established away from human settlements in TDF. There is some scientific evidence on ecological impacts on the area for only five of these invaders, with the American beaver (Castor canadensis being the species monopolizing the greatest number of studies. These results contrast with the recognition, both in TDF and worldwide, of the potential of most of these species to cause significant ecological impacts, which makes it unlikely that the lack of verified impacts on TDF reflects an absence of significant effects of these invaders on the archipelago. We suggest that future research should focus on determining population density and distribution of these and other (i.e., feral species invasive vertebrates, as well as their impacts mainly on

  15. Ecological transfer mechanisms - Terrestrial

    International Nuclear Information System (INIS)

    Martin, W.E.; Raines, Gilbert E.; Bloom, S.G.; Levin, A.A.

    1969-01-01

    Radionuclides produced by nuclear excavation detonations and released to the environment may enter a variety of biogeochemical cycles and follow essentially the same transfer pathways as their stable-element counterparts. Estimation of potential internal radiation doses to individuals and/or populations living in or near fallout-contaminated areas requires analysis of the food-chain and other ecological pathways by which radionuclides released to the environment may be returned to man. A generalized materials transfer diagram, applicable to the forest, agricultural, freshwater and marine ecosystems providing food and water to the indigenous population of Panama and Colombia in regions that could be affected by nuclear excavation of a sea-level canal between the Atlantic and Pacific Oceans, is presented. Transfer mechanisms effecting the movement of stable elements and radionuclides in terrestrial ecosystems are discussed, and methods used to simulate these processes by means of mathematical models are described to show how intake values are calculated for different radionuclides in the major ecological pathways leading to man. These data provide a basis for estimating potential internal radiation doses for comparison with the radiation protection criteria established by recognized authorities; and this, in turn, provides a basis for recommending measures to insure the radiological safety of the nuclear operation plan. (author)

  16. Implementación de una empacadora de mango en el valle de tierra caliente de Michoacán

    OpenAIRE

    Sánchez Castañeda, Maximiliano

    2011-01-01

    El presente estudio, de alguna manera plasma y evalúa la inquietud de un grupo de productores de mango en el valle de tierra caliente de Michoacán. Después de haber tenido pláticas formales e informales con productores, empacadores y trabajadores de esta cadena productiva, así como haber aplicado cuestionarios y llevado a cabo una investigación de campo.

  17. A new genus and new species of felt scales (Homoptera: Coccinea: Eriococcidae from Tierra del Fuego (Chile

    Directory of Open Access Journals (Sweden)

    Ilya A. Gavrilov-Zimin

    2016-10-01

    Full Text Available Telmatococcus igniumterrae gen. nov. et sp. nov. is described and illustrated based on the material collected from a sphagnum bog in the extreme southern part of South America (Tierra del Fuego. The new monotypic genus differs from all known genera of Eriococcidae in having short cylindrical truncated setae of the anal apparatus and pouches with numerous quinquelocular pores near the anal apparatus. The habitat of the new taxon is characterized.

  18. Centro de Control de Tierra para Colaboración de Vehículos Autónomos Marinos

    Directory of Open Access Journals (Sweden)

    J.A. Bonache Seco

    2017-12-01

    donde la incorporación del operador en la supervisión y control de las maniobras de los vehículos es un requisito imprescindible para dar seguridad y confianza a la operación realizada. Finalmente, se presenta un caso de uso del Centro de Control de Tierra donde se realiza una maniobra de seguimiento entre dos vehículos autónomos de superficie.

  19. Use of ATLANTIS TIERRA 2.0 in mapping the biodiversity (invertebrates and bryophytes) of caves in the Azorean archipelago

    OpenAIRE

    Borges, Paulo A. V.; Gabriel, Rosalina; Pereira, Fernando E. A. P.; Mendonça, Enésima; Sousa, Eva

    2008-01-01

    XII International Symposium on vulcanospeleology. Tepoztlan, Morelos, Mexico, July 2-7, 2006. In this contribution the software ATLANTIS Tierra 2.0 is described as a promising tool to be used in the conservation management of the animal and plant biodiversity of caves in Macaronesia. In the Azores, the importance of cave entrances to bryophytes is twofold: i) since these are particularly humid, sheltered habitats, they support a diverse assemblage of bryophyte species and circa 25% of the ...

  20. Seguimiento al comportamiento del mercado de tierras rurales a través de un GIS, Santander Colombia

    Directory of Open Access Journals (Sweden)

    Ricardo Lozano-Botache

    2016-01-01

    Full Text Available A pesar de los marcos legales y políticas públicas, en algunos países, los derechos de propiedad sobre la tierra siguen siendo usurpados o impedidos con métodos violentos. Este trabajo de investigación, desde el marco de referencia de la Administración de Tierras, el Neoinstitucionalismo y las herramientas computacionales –conocidas genéricamente como Sistemas de Información Geográfica (GIS, por sus siglas en inglés– presenta un modelo de observación regional de precios que, por la secuencia de datos y su proceso informático, puede mantenerse a través del tiempo como referente en procesos agrarios de restitución de tierras a víctimas del despojo, así como en la ejecución de proyectos de desarrollo social o económico.

  1. The perceived image of Tierra del Fuego (Argentina in travel stories published by “TravelPod”

    Directory of Open Access Journals (Sweden)

    Patricia Andrea Mosti

    2017-07-01

    environmental conditions, with inhospitable landscapes and, by all appearances, a pristine ecosystem. Together these things form a constitutive part the territorial identity of southern Patagonia. The cartography, the scientific expeditions, the religious missions, the journalism and the literature played an important role in the diffusion and permanency of these representations. In modern Western societies, companies have positioned the concept as a powerful tourist resource, capable of motivating travelers coming to Tierra del Fuego. The present communication proposes an approximation to the perceived image of Tierra del Fuego, according to tourists’ statements in trip blogs, taking these chronicles from sources posted on the site Travelpod. The aim is to examine the contents of the perceived image and to investigate the ways that the concept “End of the World” is resignified. The tourists’ testimonies appeal always to the idea of the End of the World; these representations can be condensed to two dimensions, the one linked to physical – geographical aspects and another that recreates symbolic contents. In the perceived images of Tierra del Fuego, there is an intermingling of the archaic, the legend and the distance, the impregnable vastness of the nature and the recollection of heroic expeditions.

  2. Negociando la tierra: empresas extranjeras, minería a gran escala y derechos humanos en Colombia

    Directory of Open Access Journals (Sweden)

    Juan David Velasco

    2014-01-01

    Full Text Available La adquisición masiva de tierras por parte de empresas extranjeras en países africanos, asiáticos y latinoamericanos refleja una nueva fase del capitalismo global (Sassen, 2013. Colombia no ha escapado a esta lógica mundial del capitalismo, pues en la última década la influencia de las empresas extranjeras en el mercado de tierras ha sido notoria. En esa lógica, este artículo compara, desde un enfoque de Derechos Humanos, las prácticas de adquisición de tierras de tres compañías extranjeras que han explotado carbón a cielo abierto en La Guajira y Cesar. Los resultados indican que la formalidad de la propiedad agraria y las restricciones institucionales de las empresas —asociadas al gobierno corporativo, la participación en bolsa de valores y el veto de compradores internacionales—influyen significativamente en el respeto a los derechos humanos.

  3. Capacidad de uso de la tierra en la cuenca de la Corriente del Lobo, Itatinga, São Paulo, Brasil

    Directory of Open Access Journals (Sweden)

    Sérgio Campos

    2011-12-01

    Full Text Available El objetivo del trabajo fue definir las clases de capacidad de uso de 2.403,25 ha de la cuenca de la Corriente del Lobo - Itatinga (SP (22° 03' 56" - 22° 59' 12" de latitud S y 48° 38' 47" - 48° 41' 25" de longitud O. La capacidad de uso de la tierra se obtuvo mediante el SIG-IDRISI 32 del cruzamiento de las cartas clinográfica y de suelos y de la Tabla de juzgamiento de clases de capacidad de uso de la tierra y del levantamiento utilitario del medio físico. Las áreas de las clases y subclases de capacidad de uso presentaron los siguientes valores: IIIa - 68.60 ha (2.85%, IIIe,s - 1919.15 ha (79.86%; IIIe - 210.60 ha (8.76%; IVe - 3.38 ha (0.14%; IVe,s - 157.42 ha (6.55% y VIe,s - 44.10 ha (1.84%. Las tierras de la cuenca se distribuyeron en tres clases (III, IV y VI y seis subclases, pero la mayor extensión (79.9% pertenece a la subclase IIIe,s. Los módulos del IDRISI permitieron discriminar, mapear y cuantificar rápidamente la capacidad de uso de las áreas de las clases y subclases de la cuenca.

  4. PERSPECTIVAS DEL PROCESO DE TITULACIÓN DE TIERRAS EN LA COMUNIDAD CAMPESINA SAN JUAN DE MIRAFLORES, 2011

    Directory of Open Access Journals (Sweden)

    Roger Ricardo Ríos Ramirez

    2014-12-01

    Full Text Available El objetivo del trabajo fue evaluar las perspectivas hacia la titulación de tierras en la Comunidad Campesina San Juan de Miraflores (CCSJM.El estudio fue de tipo descriptivo, con un diseño no experimental transversal. Se aplicó un cuestionario estructurado para evaluar perspectivas a una muestra de 353 comuneros seleccionados de manera aleatoria, estratificada y proporcional, previa validación de expertos y con una confiabilidad alfa de Cronbach α =  0.944.En la CCSJM, las parcelas no tienen las características necesarias para que la agricultura o ganadería se desarrollen, asimismo la actividad campesina no es la principal actividad económica. Asimismo, los comuneros de la CCSJM muestran una perspectiva favorable hacia la titulación de tierras.Por lo tanto, consideramos imperante el proceso de titulación de tierras y la promoción de opciones laborales distintas a las que usualmente realiza un campesino.

  5. Rock Magnetic Properties of Laguna Carmen (Tierra del Fuego, Argentina): Implications for Paleomagnetic Reconstruction

    Science.gov (United States)

    Gogorza, C. G.; Orgeira, M. J.; Ponce, F.; Fernández, M.; Laprida, C.; Coronato, A.

    2013-05-01

    We report preliminary results obtained from a multi-proxy analysis including paleomagnetic and rock-magnetic studies of two sediment cores of Laguna Carmen (53°40'60" S 68°19'0" W, ~83m asl) in the semiarid steppe in northern Tierra del Fuego island, Southernmost Patagonia, Argentina. Two short cores (115 cm) were sampled using a Livingstone piston corer during the 2011 southern fall. Sediments are massive green clays (115 to 70 cm depth) with irregularly spaced thin sandy strata and lens. Massive yellow clay with thin sandy strata continues up to 30 cm depth; from here up to 10 cm yellow massive clays domain. The topmost 10 cm are mixed yellow and green clays with fine sand. Measurements of intensity and directions of Natural Remanent Magnetization (NRM), magnetic susceptibility, isothermal remanent magnetization, saturation isothermal remanent magnetization (SIRM), back field and anhysteretic remanent magnetization at 100 mT (ARM100mT) were performed and several associated parameters calculated (ARM100mT/k and SIRM/ ARM100mT). Also, as a first estimate of relative magnetic grain-size variations, the median destructive field of the NRM (MDFNRM), was determined. Additionally, we present results of magnetic parameters measured with vibrating sample magnetometer (VSM). The stability of the NRM was analyzed by alternating field demagnetization. The magnetic properties have shown variable values, showing changes in both grain size and concentration of magnetic minerals. It was found that the main carrier of remanence is magnetite with the presence of hematite in very low percentages. This is the first paleomagnetic study performed in lakes located in the northern, semiarid fuegian steppe, where humid-dry cycles have been interpreted all along the Holocene from an aeolian paleosoil sequence (Orgeira et el, 2012). Comparison between paleomagnetic records of Laguna Carmen and results obtained in earlier studies carried out at Laguna Potrok Aike (Gogorza et al., 2012

  6. ANÁLISIS PRELIMINAR DEL TRATAMIENTO FISICOQUÍMICO Y BIOLÓGICO DEL ACEITE DIELÉCTRICO PRESENTE EN TIERRA FULLER

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    EDISON ALEXANDER AGUDELO

    2011-01-01

    Full Text Available Este estudio evalúa dos tecnologías: una físico-química y otra biológica, que buscan eliminar la contaminación por el aceite dieléctrico presente en la tierra Fuller, Buscando con ello gestionar de forma ambientalmente adecuada este residuo peligroso. Para la Tecnología físico-química, se usó hexano como solvente y se alcanzó de manera preliminar remociones del aceite dieléctrico del orden del 87% en la tierra Fuller tratada, con una relación tierra Fuller: solvente de 1:8 p/v, una velocidad de agitación de 100 rpm y un tiempo de contacto de 30 minutos. La calidad del aceite dieléctrico recuperado no es apta para su uso en equipos eléctricos, por su baja rigidez dieléctrica, baja densidad y color desfavorable. La tierra Fuller recuperada alcanzó una densidad aparente de 0.623 gr/ml, una densidad real de 2.231 gr/ml y una porosidad de 72.075 %, lo que indica al menos preliminarmente que dicha tierra está muycercana en sus características físicas a la tierra fuller limpia. Para la tecnología biológica se trató la tierra contaminada en un reactor biológico de tierra activada, evaluando la velocidad de agitación y el tiempo de degradación necesario para alcanzar niveles de contaminación adecuados que permitan disponer el residuo en un relleno sanitario convencional sin riesgo para la salud de los ecosistemas y el ser humano, esta fase aún se encuentra en experimentación y los resultados dependen del análisis cromatográfi co del aceite dieléctrico que permanece en la tierra Fuller tratada, en el cual se hará el seguimiento de 10 especies que son clave dentro de este producto, debido a su cantidad y/o toxicidad , falta comprobar la calidad química de la tierra fuller y del aceite dieléctrico recuperados en el tratamiento físico-químico, y validar el proceso biológico para degradar el aceite dieléctrico.

  7. Tierras estatales y desigualdad de género en Uruguay=State lands and gender inequality in Uruguay

    Directory of Open Access Journals (Sweden)

    Paula Florit O`Neill

    2017-06-01

    Full Text Available Resumen En Uruguay, el Instituto Nacional de Colonización (INC es la institución encargada de la adjudicación de tierra por parte del Estado, orientado a la distribución racional de la tierra y su acceso por parte de la población rural más vulnerable. A partir del año 2005, atravesó una reforma que jerarquizó su rol en las políticas de Estado y gestó un nuevo modelo de adjudicación de tierras: las experiencias asociativas. Ese mismo año, el nuevo gobierno impulsó la transversalización de género en el Estado, impulso que anclara en el INC a partir del 2013. Este artículo analiza desde una perspectiva de género la reforma refundacional y la nueva política de tierras, develando la ceguera de género de la reforma y evidenciando desafíos pendientes para la transversalización de género en el diseño de la principal modalidad de adjudicación de tierras públicas.      Abstract In Uruguay, the National Institute of Colonization is the institution resposible for the adjudication of land by the State, aimed at the rational distribution of land and its access by the most vulnerable rural population. Since 2005, the INC went through a reform that prioritized its role in the policies of the State and created a new model of land adjudication: associative experiences of colonization. In that same year, the new government promoted gender mainstreaming in the State, impulse that took roots in the INC from 2013 onwards. This article analyzes from a gender perspective the refounding reform and the new land policy, unveiling the gender blindness of the reform and highlighting pending challenges for gender mainstreaming in the design of the main public land adjudication modality.

  8. Análisis de nuevos estándares para reducir datos de gravedad: aplicación en Tierra del Fuego

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    Ana Carolina Pedraza De Marchi

    2011-12-01

    reducing gravity data in order to improve the precision, accuracy, and usefulness of geophysical gravity anomalies. The new standards take into account the increased current computing power, the modern satellite technology to determine the height and positioning of the gravity stations, the improved topographic / bathymetric databases, and new mathematical algorithms. They are based on internationally accepted procedures, protocols, equations and parameters, and in many cases differ from those presented in current geophysical textbooks and existing gravity databases. The most important change that the new standards suggest, due to the greater use of Global Positioning System (GPS for field gravimetric work, is the use of terrestrial reference ellipsoid adopted internationally to define the vertical datum. The anomalies calculated with the new standards could be modified by the adjective "ellipsoidal" to differentiate them from the anomalies calculated by conventional elevations referred to the geoid. Gravity reductions, following the traditional and new recommendations and standards were calculated in the province of Tierra del Fuego. We used digital elevation models and geopotential models to assess the effectiveness of its use in gravity reductions. The land gravimetric data were integrated with free air anomalies derived from satellite altimetry in the sea, in order to compute an ellipsoidal isostatic anomaly map.

  9. Tierras de la microcuenca potrerillo (Cauca, Colombia: Clasificación local en relación con propiedades edáficas.

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    Cerón Rengifo Carmen Patricia

    2003-12-01

    Full Text Available Este estudio se realizó con el objetivo de relacionar la clasificación local de tierras con propiedades físicas, químicas y biológicas del suelo. Se hicieron entrevistas a 36 agricultores de la microcuenca, Potrerillo, Cauca, Colombia, para considerar criterios culturales de clasificación local; se tomaron muestras de suelo en 8 tierras, de 0 a 5 y 0 a 20 cm, con 5 repeticiones. Se determinó color, textura, N y P disponible, C total, fracción liviana de materia orgánica (LL, PH, Ca, K, Mg y Al. Los datos se trabajaron estadísticamente a partir de análisis de varianza, prueba Duncan y análisis de clasificación de datos. La información sugiere que los agricultores diferencias las tierras a partir de la ubicación, características físicas del suelo y de categorías culturales llamadas tierra buena, mala, brava y cansada. Las tierras consideradas buenas se relacionan con colores pardos oscuros, contenidos más altos de N, C y fracción LL, mayor densidad de miriápodos en tierras con vegetación arbórea y mayor biomasa de lombrices en barbecho de la parte baja de la colina. Entre las tierras de menor calidad, disminuye N, C fracción LL y Al y aumenta el pH; en aquellas que no son utilizadas son frecuentes los colores amarillos o rojos, decrecen los valores de N, C, LL, Ph y se incrementa el Al.

  10. Arriendo y desigualdad en las tierras altas de Jujuy (Argentina a fines del siglo XIX

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    Cecilia A. Fandos

    2016-01-01

    Full Text Available Las estructuras agrarias originadas en los procesos más generales de desarrollo capitalista y de redefinición de los derechos de propiedad del siglo XIX en la provincia argentina de Jujuy, resultaron favorables a la formación de importantes latifundios. La contracara de esa fuerte concentración de tierras fue la existencia de un amplio sector de la sociedad que compartía la condición de arrendatarios. De ahí que en este artículo nos proponemos estudiar a los arrendatarios como productores –la riqueza y los ingresos brutos procedentes de la explotación rural que tenían a su cargo– a fin de indagar su capacidad de remuneración, contrastándolos entre sí y con otras situaciones sociales. Para ello, analizamos dos casos que tratan el asunto de sus relaciones de producción en el arriendo. A partir de fuentes fiscales y censales de la década de 1890 que contienen datos de la actividad agropecuaria y de informes sobre la rentabilidad de los distintos productos de origen agrícola o ganaderos de la misma época, reconstruimos el ingreso bruto de esas unidades para cada uno de los actores involucrados en ellas y analizamos los niveles de desigualdad para ese conjunto social.

  11. Tierras, encomiendas y élites. El caso de Jujuy en el siglo XVII

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    Ferreiro, Juan Pablo

    1995-06-01

    Full Text Available Not available.

    Este artículo describe y analiza los rasgos característicos y principales del grupo de encomenderos que componían el sector nuclear de la élite jujeña a principios del siglo XVII. Para esto se utilizaron fuentes de diversa índole procedentes del Archivo de Tribunales de Jujuy, entre ellas sobresalen testamentos, dotes, obligaciones de pago y poderes; documentación que por su contenido permite analizar la forma en la que esta élite se constituyó, así como los mecanismos utilizados para acceder y/o conservar un puesto privilegiado en la naciente sociedad jujeña. Desde esta perspectiva se presta particular atención a la dinámica establecida por las redes familiares que sustentan esas posiciones a través de la propiedad o posesión de tierras trabajadas por indios de encomienda, y a su participación activa en el Cabildo local.

  12. Justificación curricular de la asignatura Arquitectura de tierra. Caso: Tamaulipas, México

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    Dora Luisa Roux Oropeza

    2016-08-01

    Full Text Available La globalización y los organismos internacionales hanrevolucionado el funcionamiento de las instituciones de educación superior. Las exigencias actualesimplican, entre otras,la gestión deestudios curriculares bajo paradigmas emergentes que justifiquen programas y planes encaminados a la solución de las problemáticas sociales globales. Tomando como referencia lo anterior, se presentan los resultados del análisis curricular que fundamentó la inclusión de la asignatura Arquitectura de Tierra, en la Facultad de Arquitectura Diseño y Urbanismo en Tamaulipas, México. AbstractGlobalization and international agencies have revolutionized the functioning of institutions of higher education; the requirements to them, involving among others, managing curriculum studies on emerging paradigms that justify programs and planswith responsibility for solving global social problems. With reference to the above, the results of the curriculum analysis that informed the inclusion of the subject Earthen Architecture in the Faculty of Architecture and Urban Design in Tamaulipas, Mexico.

  13. EVALUATION OF INSECTICIDES FOR PEST CONTROL IN MANGO (Mangifera indica L. IN TIERRA CALIENTE, GUERRERO, MEXICO

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    Yuridia Duran

    2017-12-01

    Full Text Available The mango crop is attacked by various pests, in Arcelia, Tierra Caliente, Guerrero, Mexico. Scale insects (Hemiptera and thrips (Thysanoptera were identified, the pesticides imidacloprid, spinosad, sulfur and mineral oil were tested against them, as well as their effect on fruit quality, using pest action thresholds. The thrips Frankliniella invasor appeared in the highest populations, but F. difficilis, F. occidentalis, F. fortissima, F. cephalica, Leptothrips macconnelli, L. bifurcatus and L. theobromae were also found. It was observed that mineral oil maintained the lowest populations and least damage in fruit; thrips species did not cause significant damage because they were seasonal pests that only occur when soft tissue is available in plants and once this tissue becomes unavailable populations diminish without the need of insecticides.  The mite Cisaberoptus kenyae was identified, which in high populations can cause crop damage; for its control sulfur yielded better results. The scale Milviscutulus mangiferae was present in very low populations. Treatment with mineral oil resulted in the highest quality fruits.

  14. EL SITIO HESHKAIA 35: NUEVOS DATOS SOBRE LA ARQUEOLOGÍA DE MOAT (TIERRA DEL FUEGO, ARGENTINA / Heshkaia 35 site: new data on the archaeology of Moat (Tierra del Fuego, Argentina

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    Atilio Francisco Zangrando

    2014-11-01

    Full Text Available arqueológicos recuperados en el sitio Heshkaia 35 (costa sur de Tierra del Fuego, Argentina. Este sitio se ubica en un ámbito costero en la sección media de la cuenca del río Moat y registra ocupaciones durante el Holoceno Tardío (ca. 800-500 AP. La diversidad tecnológica y el registro zooarqueológico señalan el desarrollo de actividades múltiples. Los artefactos líticos dominan el conjunto tecnológico. Los desechos líticos indican un fuerte énfasis hacia los estadios finales de talla, puesto de manifiesto en la baja presencia de artefactos con corteza y la elevada frecuencia de lascas de formatización y de reactivación de filos. El conjunto zooarqueológico se compone mayormente de restos óseos de guanacos. Los moluscos también habrían cumplido un rol significativo en la dieta. Restos óseos de mamíferos marinos, zorros, aves y peces están representados por frecuencias bajas. La composición artefactual y arqueofaunística estaría indicando que el aprovisionamiento de recursos se habría articulado principalmente desde el ámbito costero y no necesariamente en el mar. Se discuten las implicaciones de esta evidencia para las pautas conductuales de cazadores-recolectores en la costa sur de Tierra del Fuego. Palabras Clave: Arqueología de costas, Cazadores-recolectores, Tierra del Fuego, Holoceno Tardío   Abstract This paper presents and discusses the archaeological evidence from Heshkaia 35 site (southern coast of Tierra del Fuego, Argentina. This site is located in a coastal setting in the middle section of the Moat River Basin and records occupations during the Late Holocene (ca. 800-500 BP. Technological diversity and the zooarchaeological record point to the development of multiple activities. Lithic artifacts dominate the technological assemblage. Lithic debitage indicates a strong emphasis towards final stages of reduction, shown by the lower occurrence of artifacts with cortex and the high frequency resharpening

  15. El escritor, las sombras y la Patria: En esta dulce tierra de Andrés Rivera The writer, the shadows and the homeland in Andrés Rivera's "La dulce tierra"

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    Carmen Perilli

    2007-12-01

    Full Text Available La novela En esta dulce tierra arma un simulacro histórico que se desintegra en una narración de finales múltiples. Parodia su nombre "en esta dulce tierra" ya que el circunstancial anuncia sucesos terribles que hacen estallar el adjetivo. Remite a la literatura decimonónica, en especial a los romances fundacionales como Amalia de José Mármol. La nación se imagina como espacio cerrado, clausurado por el despotismo en el asilo, la morgue, la cárcel, el sótano. Los protagonistas se mueven ilusoriamente de Sur a Norte. Si Sarmiento invoca la sombra de Facundo, Rivera evoca en Cufré otras propias sombras, dobles en tiempos y lugares otros. La narración de la historia argentina es la narración de una derrota, la de la civilización. La imagen histórica es disfórica: el mundo está enfermo, ebrio de sangre y violencia. Facundo es la sombra de la barbarie, cifra de la naturaleza americana, producto de los llanos riojanos. Cufré es la sombra de una clase "culta" que dibuja en su trayectoria una figura paradojal. Las dos son víctimas de una tierra concebida como naturaleza bárbara en un caso y de una tierra construida como patria siniestra en el otro. El Poder actúa como una segunda naturaleza que, en esta tierra, tiene el sabor de la muerte.The novel En esta dulce tierra sets up a historical pretense that disintegrates into several endings. The title is an irony, since terrible events take place in this "sweet land." It refers to the literature of the XIX century, especially to the founding romances such as that of José Mármol's Amalia. The nation is envisioned as a closed space relegated by despotism to the asylum, the morgue, the jail, the basement. The characters live an illusion moving from north to south. If Sarmiento invokes the shadow of Facundo, Rivera evokes some of his own shadows in Cufré, doubles in different times and spaces. The narration of the Argentine history is a story of defeat: civilizarion's. The historical

  16. Soil and terrestrial biology studies

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    Soil and terrestrial biology studies focused on developing an understanding of the uptake of gaseous substances from the atmosphere by plants, biodegradation of oil, and the movement of Pu in the terrestrial ecosystems of the southeastern United States. Mathematical models were developed for SO 2 and tritium uptake from the atmosphere by plants; the uptake of tritium by soil microorganisms was measured; and the relationships among the Pu content of soil, plants, and animals of the Savannah River Plant area were studied. Preliminary results are reported for studies on the biodegradation of waste oil on soil surfaces

  17. Priapism caused by 'Tribulus terrestris'.

    Science.gov (United States)

    Campanelli, M; De Thomasis, R; Tenaglia, R L

    2016-01-01

    A 36-year-old Caucasian man was diagnosed with a 72-h-lasting priapism that occurred after the assumption of a Herbal supplement based on Tribulus terrestris, which is becoming increasingly popular for the treatment of sexual dysfunction. The patient underwent a cavernoglandular shunt (Ebbehoj shunt) in order to obtain complete detumescence, from which derived negative post-episode outcomes on sexual function. All patients consuming non-FDA-approved alternative supplements such as Tribulus terrestris should be warned about the possible serious side effects.

  18. La ganadería lanar en Madrid y su tierra durante la Edad Media

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    Tomás Puñal Fernández

    1998-01-01

    Full Text Available El estudio de la ganadería en general y ovina en particular ofrece un campo muy generoso de investigación porque permite conocer muchas de las estructuras socioeconómicas regionales y locales de un país o territorio. En el caso de Madrid dicho estudio es importante por cuanto en el conjunto de las labores agropecuarias del concejo, las ganaderas fueron las que mejor marcaron su desarrollo económico. La tierra madrileña es tierra de ganado, sobre todo lanar, y ello fue el punto de referencia de diversas actividades económicas que iban desde el abastecimiento de carne para la alimentación hasta la obtención de materia prima, lana y pieles, para las industrias textil y del cuero. Para tener una visión más amplia e interdisciplinar el presente estudio se ha hecho desde una doble perspectiva económica y social. Desde la ganadería estante y local a la trashumante, con especial mención a la Mesta y toda su problemática, así como los aspectos cuantitativos derivados del número de ovejas y el tamaño y tipo de los rebaños y sus aspectos fiscales concomitantes. En relación a ello toda la infraestructura de pastos y cañadas. Los aspectos sociales se refieren a los propietarios de ovejas como una oligarquía rural de labradores enriquecidos, así como a los trabajadores del ganado, es decir los pastores, sus contratos, salarios y condiciones de vida. En conjunto el panorama que se ofrece es muy significativo y permite acercarnos un poco más a la realidad socioeconómica del Madrid medieval.The study of the livestock in general and sheep in particular, offers a huge field to research as it allows to know many of the local and regional socioeconomíc structures of a city or country. In the case of Madrid, that study is important because the sheep livestock is, among the rest of the agricultural activities, the main one for its contribution to the economic development. Madrid is a livestock área, mainly for sheep, as the point of

  19. Mires and mire types of Peninsula Mitre, Tierra del Fuego, Argentina

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    A. Grootjans

    2014-01-01

    Full Text Available In 2007, a field visit by members of the International Mire Conservation Group (IMCG to the Atlantic coast of Peninsula Mitre (the easternmost part of Isla Grande de Tierra del Fuego, Argentina gathered information on mire diversity in this remote wild area with largely pristine mires. Our expedition showed that Peninsula Mitre hosts a wide variety of habitats across two exciting ecological gradients: (i a regional west–east gradient from Sphagnum magellanicum dominated mires in the west to Astelia pumila dominated mires in the east; and (ii a gradient from extremely acid to extremely carbonate rich mire types induced by local bedrock. The large variety of hydromorphological mire types comprises raised bogs, blanket bogs, sloping fens, string fens, flat fens and calcareous spring fens. In the Atlantic coastal area, the abundance of Sphagnum magellanicum in the ombrogenic systems decreases conspicuously from west to east with the species being almost absent in the east. However, the fossil record shows thick layers of Sphagnum peat close beneath mire surfaces everywhere, indicating that substantial hydrological and ecological changes have taken place in the recent past. We observed large scale erosion in the mires along the Atlantic coast. Locally, well-developed fen systems are present, including calcareous spring fens with active travertine (tufa deposition. The regional vegetation can be regarded as a parallel to that of boreal oceanic regions in the northern hemisphere. The mires and peatlands of the peninsula are of global significance. They are impressive, peculiar, extensive and largely pristine mires in a globally very rare climatic and biogeographical context embedded in a landscape with significant natural dynamics. The damaging impact of free-roaming cattle on the mires and upland vegetation is, however, conspicuous and needs urgent attention. Peninsula Mitre deserves the highest possible protection, e.g. as a provincial protected

  20. EL TURISMO COMO FACTOR DIFERENCIADOR EN EL MERCADO DE LA TIERRA: LOS MODELOS DE EL VERGER Y ELS POBLETS.

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    Salvador Salort Vives

    1989-01-01

    Full Text Available El presente artículo pretende analizar los cambios recientes ocurridos en el mercado de la tierra en dos municipios del litoral de la provincia de Alacant, EL VERGER y ELS POBLETS cuyos rasgos definitorios son: un índice de movilidad moderado; un predominio de los jubilados y pensionistas en cuanto a los agentes vendedores y una mayor divers ificación en los agentes compradores. Los móviles de los primeros obedecen a una crecien te incertidumbre sobre el futuro de sus explotaciones agrarias, la escasez y grado de salinidad del agua y en el cas o de ELS POBLETS los altos precios que rigen los intercambios de la tierra para uso no agrícola. Ello está generando un cambio en la mentalidad de los agricultores, ahora más proclives a desprenderse de las tierras. Los móviles de los agentes compradores se orientan a conservar o ampliar el patrimonio familiar o invertir en un sector considerado “seguro”. En definitiva, aunque subsiste un con tinuado proceso de fragmentación del suelo agrícola, se constata la formación de propiedades de dimensiones superiores a 2 Ha cuyos propietarios son no agricultores; por otra parte la presión residencia l en ELS POBLETS está produciendo un fuerte impacto en la organización del espacio rural por la vía de la diversificación de los usos del suelo.

  1. Geoprocesamiento aplicado al analisis del uso de la tierra en el municipio de San Pedro de Ycuamandyyú, Paraguay.

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    Oscar Agustín Torres Figueredo

    2010-08-01

    Full Text Available El municipio de San Pedro de Ycuamandyyú está ubicado en el noroeste de la región oriental del Paraguay. Los objetivos de este trabajo constituyen la elaboración y el análisis del mapa del uso de la tierra para la planificación de actividades forestales en la zona, para los cuales se utilizaron técnicas de cartografía, sensores remotos y (SIG Sistemas de Informaciones Geográficas, que posibilitaron el análisis de informaciones provenientes de imágenes satelitales LANDSAT TM 5, de cartas topográficas y de (GPS Sistema de Posicionamiento Global, que permitió el procesamiento de datos en el programa Idrisi 2.0 para la confección de un mapa que posibilitó el análisis sobre la situación del uso de la tierra en el municipio. Se distinguió categorías predominantes como praderas altas o campos naturales, uso agropecuario y praderas bajas o bañados, siendo la cobertura forestal con valor inferior al 25%. Se concluyó que el municipio presenta bastantes áreas de campos naturales y uso agropecuario que podrían utilizarse para actividades de reforestación, sea con especies nativas o exóticas de rápido crecimiento con la finalidad de obtener valores de cobertura forestal en equilibrio con las demás categorías de uso de la tierra.

  2. GEOPROCESAMIENTO APLICADO AL ANALISIS DEL USO DE LA TIERRA EN EL MUNICIPIO DE SAN PEDRO DE YCUAMANDYYÚ, PARAGUAY

    Directory of Open Access Journals (Sweden)

    Oscar Agustín Torres Figueredo

    2002-10-01

    Full Text Available El municipio de San Pedro de Ycuamandyyú está ubicado en el noroeste de la región oriental del Paraguay. Los objetivos de este trabajo constituyen la elaboración y el análisis del mapa del uso de la tierra para la planificación de actividades forestales en la zona, para los cuales se utilizaron técnicas de cartografía, sensores remotos y (SIG Sistemas de Informaciones Geográficas, que posibilitaron el análisis de informaciones provenientes de imágenes satelitales LANDSAT TM 5, de cartas topográficas y de (GPS Sistema de Posicionamiento Global, que permitió el procesamiento de datos en el programa Idrisi 2.0 para la confección de un mapa que posibilitó el análisis sobre la situación del uso de la tierra en el municipio. Se distinguió categorías predominantes como praderas altas o campos naturales, uso agropecuario y praderas bajas o bañados, siendo la cobertura forestal con valor inferior al 25%. Se concluyó que el municipio presenta bastantes áreas de campos naturales y uso agropecuario que podrían utilizarse para actividades de reforestación, sea con especies nativas o exóticas de rápido crecimiento con la finalidad de obtener valores de cobertura forestal en equilibrio con las demás categorías de uso de la tierra.

  3. Geoprocesamiento aplicado al analisis del uso de la tierra en el municipio de San Pedro de Ycuamandyyú , Paraguay

    Directory of Open Access Journals (Sweden)

    Oscar Agustín Figueredo Torres

    2002-01-01

    Full Text Available El municipio de San Pedro de Ycuamandyyú está ubicado en el noroeste de la región oriental del Paraguay. Los objetivos de este trabajo constituyen la elaboración y el análisis del mapa del uso de la tierra para la planificación de actividades forestales en la zona, para los cuales se utilizaron técnicas de cartografía, sensores remotos y (SIG Sistemas de Informaciones Geográficas, que posibilitaron el análisis de informaciones provenientes de imágenes satelitales LANDSAT TM 5, de cartas topográficas y de (GPS Sistema de Posicionamiento Global, que permitió el procesamiento de datos en el programa Idrisi 2.0 para la confección de un mapa que posibilitó el análisis sobre la situación del uso de la tierra en el municipio. Se distinguió categorías predominantes como praderas altas o campos naturales, uso agropecuario y praderas bajas o bañados, siendo la cobertura forestal con valor inferior al 25%. Se concluyó que el municipio presenta bastantes áreas de campos naturales y uso agropecuario que podrían utilizarse para actividades de reforestación, sea con especies nativas o exóticas de rápido crecimiento con la finalidad de obtener valores de cobertura forestal en equilibrio con las demás categorías de uso de la tierra.

  4. Entendiendo un programa de reparación: reconstrucción del proceso de creación e implementación de familias en su tierra – FEST– El caso del municipio de La Palma, Cundinamarca

    OpenAIRE

    García Cadavid, Laura Andrea

    2016-01-01

    A partir de la reconstrucción del proceso de creación e implementación del programa presidencial para la reparación a población desplazada Familias En Su Tierra, se exploran las dificultades y retos que enfrenta la Ley de Víctimas y Restitución de Tierras.

  5. El acaparamiento de tierras como proceso dinámico. Las estrategias de los actores en contextos de estancamiento económico

    Directory of Open Access Journals (Sweden)

    Carla Gras

    2017-01-01

    Full Text Available Este artículo pretende contribuir a la comprensión de los procesos de acaparamiento de tierras. A partir de un análisis realizado en el norte de Córdoba (Argentina, se sugiere que dicho fenómeno: (a no es lineal, uniforme ni se incrementa de manera sostenida en el tiempo; y (b no se limita a la concentración de tierras sino que integra recursos estratégicos (financieros, tecnológicos, gerenciales que convergen en el objetivo más general de acaparamiento de capital. Analizamos una dinámica específica, la “ralentización” o disminución en la cantidad de tierra controlada por las empresas, bajo la hipótesis que ella no constituye necesariamente una retracción del acaparamiento.

  6. SAFEGUARD OF TRADITIONAL MUSIC IN TIERRA CALIENTE Preservation and development programs of cultural patrimony of a region

    Directory of Open Access Journals (Sweden)

    Alejandro Martínez de la Rosa

    2010-05-01

    Full Text Available Traditional music of Mexico is in process of change andmuch of its wealth still is unknown, and so is necessary toinvestigate and to spread the variants, moreoverestablishing development cultural programs, therefore inthis article we revise three initiatives promoted for differentcultural organizations in last year’s, creates for preservingand revitalizing the musical patrimony of Tierra Caliente ofMichoacan region, and we developed a critical analysisfrom results of every one programs. The reflection aboutcultural problem force to continue the relationship betweenall culture agents of these projects, as soon as to increasethe promotion and spread in local ambit where the musicaltradition arises.

  7. La Carta de la Tierra: experiencias internacionales de innovación en educación superior

    OpenAIRE

    Arenas Ortiz, María; Hinojosa Pareja, Eva Francisca; López López, María Carmen

    2013-01-01

    La Carta de la Tierra es una iniciativa de la sociedad civil que pretende reforzar el valor de la sostenibilidad y la interdependencia entre las personas y sus contextos (Gorvachev, 2006). Esta declaración, avalada por la unesco, es considerada un instrumento de gran valor educativo en proyectos internacionales como el Decenio de la Educación para el Desarrollo Sostenible (2005-2014) promovido por Naciones Unidas. Este trabajo se centra en el estudio, a través de una tetodología basada en el ...

  8. Forestaciones en tierras agrarias de la Región de Murcia : cambios medioambientales y paisajísticos

    OpenAIRE

    González Botía, Miguel Ángel

    2017-01-01

    El objetivo principal de esta tesis ha sido el estudio de las consecuencias derivadas de las forestaciones de tierras agrarias abandonadas en la Región de Murcia (FOTARM), considerada una medida agroambiental de la PAC, que pretende paliar los graves problemas de erosión, degradación y desertificación, derivados de dicho abandono. Primeramente se ha realizado un minucioso análisis de las forestaciones, que se llevaron a cabo en dos periodos: el primero (y principal) de 1994 a 1999, (llegando ...

  9. Género, propiedad y empoderamiento: tierra, Estado y mercado en América Latina [Reseña

    OpenAIRE

    García Núñez, Luis Fernando; León, Magdalena; Deere, Carmen Diana

    2001-01-01

    Es un texto de una gran importancia para el momento actual. Un documento que trabaja el problema de género desde otras perspectivas. Integra el conflicto alrededor de las fronteras de lo social, lo político, lo cultural y lo económico. "Desde nuestra investigación inicial en los años setenta y ochenta se habían realizado relativamente pocos estudios sobre género y derecho a la tierra, y casi no se había prestado atención a las implicaciones de género de la contrarreforma agraria neoliberal". ...

  10. Modelos del planeta Tierra en escolares rurales de Chile / Planet Earth models about students in rural schools from Chile

    Directory of Open Access Journals (Sweden)

    Paula Alonqueo Boudon

    2015-12-01

    Full Text Available RESUMEN El presente estudio tuvo como objetivo identificar los modelos del planeta Tierra en escolares mapuches y no mapuches de procedencia rural. Los participantes fueron 40 escolares distribuidos en dos grupos de edad, quienes respondieron a una tarea cognitiva que indaga la representación de la forma del planeta Tierra. En base al grado de acuerdo con la representación científica, cada participante fue categorizado en uno de cuatro modelos del planeta Tierra. El modelo 4, concordante con el conocimiento científico, no fue observado, pues la mayoría de los participantes se concentra en el modelo 3 en el que coexisten conocimientos previos con algunos elementos científicos. En los niños no mapuches se aprecia que el modelo del planeta Tierra se ajusta a los significados científicos a medida que aumenta el conocimiento escolar. Por el contrario, en los niños mapuches no se observa esta tendencia. Se discute el papel de la cultura y la enseñanza en el aprendizaje del modelo científico del planeta. ABSTRACT The aim of this study was to identify planet Earth models in mapuches and non mapuches students of rural origin. The participants were 40 students divided into two age groups who responded to a cognitive task which explores the representation of the shape of the planet Earth. Based on the degree of agreement with the scientific representation, each participant was categorized into one of four models of planet Earth. Model 4, consistent with the scientific knowledge was not observed because the majority of the participants were concentrated in Model 3. In non mapuche children, it is observed that the model of the planet Earth is adjusted to the scientific meaning in accordance with the increase of school knowledge. On the other hand, this trend is not observed in mapuche children. The role of culture and teaching is discussed in the learning of planet scientific model.

  11. Difference fractal surfaces poured earth floors Tamaulipas / Diferencia fractal en superficies de tierra vertida con suelo de Tamaulipas

    Directory of Open Access Journals (Sweden)

    Edgardo Jonathan Suárez Dominguez

    2013-09-01

    Full Text Available Poured earth is a sustainable construction and economically feasible technique to develop in Tamaulipas, by the materials availability and traditional manufacturing procedures uses. There are several variables to be considered in these elements for their properties, among them it can be found roughness and porosity analysis which are important because they are related to material mechanical resistance and durability. This study aimed to characterize solid surfaces using fractal dimension to know its uniformity and porosity, compared with a concrete surface. Solids were obtained from poured earth of two combinations of soils stabilized with cement from the state of Tamaulipas. We found that a surface of a sample, obtained with ground, is more uniform than poured concrete surface, and that fractal dimension is higher while porosity increases; results suggest that this is because of the presence of clay in the poured earth mixtures. La tierra vertida es una técnica constructiva sustentable y económicamente viable para desarrollarse en Tamaulipas, por la disponibilidad de materiales y procedimientos de fabricación similares a los tradicionales. Son diversas las variables que deben estudiarse en estos elementos para conocer sus propiedades, entre las que se encuentran la rugosidad y la porosidad, las cuales son importantes debido a su estrecha relación con la resistencia mecánica y durabilidad del material estudiado. El presente trabajo tuvo por objetivo caracterizar superficies sólidas a partir de la dimensión fractal para conocer su uniformidad y porosidad, comparándola con una superficie de concreto. Los sólidos fueron obtenidos a partir de tierra vertida conformada de dos combinaciones de suelos estabilizadas con cemento provenientes del estado de Tamaulipas. Se encontró que una superficie de tierra vertida es menos irregular que una superficie de concreto además de tener una menor porosidad reflejada en una menor dimensión fractal

  12. Curva de retención suelo-agua e inicio de monitoreo en Tierra Blanca Joven (TBJ)

    OpenAIRE

    José A. Chávez; Reynaldo López; Lubomir Kopecky; José Landaverde

    2013-01-01

    En El Salvador durante la época de lluvias o cuando ocurren terremotos, las áreas cubiertas por las tefras volcánicas Tierra Blanca Joven (TBJ) sufren movimientos de ladera, licuefacción y erosión provocando pérdidas ambientales, sociales y económicas importantes. Para iniciar la caracterización de estos suelos parcialmente saturados, valores de succión de una unidad de caída de TBJ fueron obtenidos con la olla de presión, centrífuga y papel filtro para construir la Curva de Retención Suelo-A...

  13. Evaluación de tierras por capacidad de uso urbano en la zona periurbana de Villahermosa Tabasco.

    OpenAIRE

    Morales Garduza, Marcos Antonio

    2012-01-01

    En planicies tropicales húmedas del Sureste de México, varias ciudades se asientan en tierras bajas sujetas a inundación, y como alternativa para la planeación de asentamientos humanos, se desarrolló una metodología que evalúa la capacidad de uso del suelo urbano. Mediante revisión bibliográfica se seleccionaron los factores ambientales que presentan mayores restricciones para el uso urbano como inundación, relieve, pendiente, suelo y uso del suelo. Se diseñó un modelo matemático que determin...

  14. Tierra y negocios en Salta a fines del siglo XIX y principios del XX. Estudio de casos

    OpenAIRE

    del Valle Michel, Azucena; Parrón, Mario Gustavo; Corregidor, Blanca Esther

    2017-01-01

    El trabajo analiza las estrategias desarrolladas por Vicente Arquati y Paulino Echazú en diferentes espacios socioeconómicos de la provincia de Salta, entre fines del siglo XIX y principios del XX. Las mismas, posibilitaron la concentración de tierras, la comercialización de productos y otras actividades lucrativas. Sobre estas cuestiones se plantean interrogantes para identificar los factores explicativos de la imposibilidad de esos sujetos de mantener sus logros económicos, a pesar de haber...

  15. Estudio de la estructura cortical en la Isla de Tierra del Fuego a partir de datos sismológicos

    OpenAIRE

    Buffoni, C.; Schimmel, Martin; Sabbione, N.C.; Rosa, M.L.

    2012-01-01

    La Isla de Tierra del Fuego (TdF) se encuentra ubicada en el extremo sur de la Cuenca de Magallanes, donde el borde transformante entre la Placa de Scotia y la Sudamericana define el Sistema de Fallas Magallanes-Fagnano (MFS), cuya falla principal tiene un movimiento sinestral. Con el fin de obtener información de la corteza, se realizó un análisis de funciones receptoras (FR) a partir de datos registrados en cinco estaciones sismológicas instaladas en la Isla. Una FR es el resultado de un pr...

  16. Medición de la resistencia de la tierra en los circuitos eléctricos

    OpenAIRE

    Vásquez Novoa, Gustavo Enríque

    2008-01-01

    La mayoría de las personas que conectan un toma corriente para una Pc, saben que esta debe ser polarizada pero el problema que enfrentan es: ¿cómo puede verificarse que el valor de la resistencia eléctrica de la tierra en la conexión de polarización que se ha realizado en el circuito eléctrico está de acuerdo a lo normado? En este articulo se presenta una comparación entre tres alternativas para realizar esta verificación: 1. un probador desarrollado en ITCA-FEPADE, que se conecta directament...

  17. «En tierra de hombres» (2005). El acoso psicológico en el trabajo

    OpenAIRE

    Carmen María VIZOSO GÓMEZ

    2016-01-01

    El acoso psicológico en el trabajo está considerado un grave problema en el entorno laboral debido a los efectos negativos que provoca no solo en la convivencia dentro de la empresa y en la productividad de los trabajadores sino también en la salud de la víctima y en el bienestar de su familia. La película En tierra de hombres está inspirada en un caso real de acoso en el trabajo, concretamente de acoso sexual, sufrido por las mujeres que trabajaban en una mina de hierro. Esta situación desem...

  18. Tierras Bajas de Bolivia: II Jornadas de Antropología, Historia y Arqueología

    OpenAIRE

    Combès, Isabelle

    2016-01-01

    Las II Jornadas de Antropología, Historia y Arqueología de las tierras bajas de Bolivia y áreas adyacentes se desarrollaron del 14 al 16 de octubre en Santa Cruz de la Sierra, en los locales del Museo de Historia de la Universidad Autónoma Gabriel René Moreno (UAGRM). Este encuentro fue organizado por el Museo de Historia a través del Centro de Investigaciones Históricas y Antropológicas (CIHA), del Instituto Francés de Estudios Andinos, del programa de posgrado en Historia de la Universidad...

  19. Terrestrial ecosystems and their change

    Science.gov (United States)

    Anatoly Z. Shvidenko; Eric Gustafson; A. David McGuire; Vjacheslav I. Kharuk; Dmitry G. Schepaschenko; Herman H. Shugart; Nadezhda M. Tchebakova; Natalia N. Vygodskaya; Alexander A. Onuchin; Daniel J. Hayes; Ian McCallum; Shamil Maksyutov; Ludmila V. Mukhortova; Amber J. Soja; Luca Belelli-Marchesini; Julia A. Kurbatova; Alexander V. Oltchev; Elena I. Parfenova; Jacquelyn K. Shuman

    2012-01-01

    This chapter considers the current state of Siberian terrestrial ecosystems, their spatial distribution, and major biometric characteristics. Ongoing climate change and the dramatic increase of accompanying anthropogenic pressure provide different but mostly negative impacts on Siberian ecosystems. Future climates of the region may lead to substantial drying on large...

  20. Provenance of the terrestrial planets.

    Science.gov (United States)

    Wetherill, G W

    1994-01-01

    Earlier work on the simultaneous accumulation of the asteroid belt and the terrestrial planets is extended to investigate the relative contribution to the final planets made by material from different heliocentric distances. As before, stochastic variations intrinsic to the accumulation processes lead to a variety of final planetary configurations, but include systems having a number of features similar to our solar system. Fifty-nine new simulations are presented, from which thirteen are selected as more similar to our solar system than the others. It is found that the concept of "local feeding zones" for each final terrestrial planet has no validity for this model. Instead, the final terrestrial planets receive major contributions from bodies ranging from 0.5 to at least 2.5 AU, and often to greater distances. Nevertheless, there is a correlation between the final heliocentric distance of a planet and its average provenance. Together with the effect of stochastic fluctuations, this permits variation in the composition of the terrestrial planets, such as the difference in the decompressed density of Earth and Mars. Biologically important light elements, derived from the asteroidal region, are likely to have been significant constituents of the Earth during its formation.

  1. Aquatic and Terrestrial Environment 2004

    DEFF Research Database (Denmark)

    Andersen, J. M.; Boutrup, S.; Bijl, L. van der

    , watercourses, lakes and marine waters and the pressures upon them and reviews the monitoring of terrestrial natural habitats and selected plants and animals. The report is based on the annual reports prepared for each subprogramme by the Topic Centres. The latter reports are mainly based on data collected...

  2. Cambio del uso de la tierra y pérdida de la cobertura boscosa, comunidades agrarias Sechina, La Ensenada y Cerro San Gil, Izabal Guatemala

    Directory of Open Access Journals (Sweden)

    Eddi Alejandro Vanegas Chacón

    2016-07-01

    Full Text Available En Guatemala, pocas temáticas son abordadas con tanta pasión como el acceso a la tierra y sus relaciones de productividad. Ante el juicio histórico y la evidencia de las estadísticas se deslumbra que las políticas agrarias de los últimos cincuenta años, si bien mitigaron la pobreza en el agro rural conllevaron con ellas daños ambientales irreversibles y deudas agrarias millonarias. Se estudió la dinámica del cambio de uso de la tierra y la pérdida de la cobertura boscosa en las comunidades agrarias beneficiadas por la Ley de Transformación Agraria, Sechina, La Ensenada y Cerro San Gil ubicadas en el departamento de Izabal. Se utilizó fotointerpretación y se realizaron estudios semidetallados de la intensidad de la tierra para el periodo 1958 a 2010. Se concluyó que bajo las premisas de “mejora a la tierra” de la Ley de Transformación Agraria ocurrió cambio de uso y cobertura de la tierra, de forestal a agropecuaria, en las comunidades agrarias Sechina 42%, La Ensenada 46,2% y Cerro San Gil 48,6%, donde se promovieron sistemas de aprovechamiento agrícola que conllevaron al sobre-uso de las tierras en 42%, 78% y 30%, respectivamente. Esto sugiere, que la adquisición de la tierra no es el fin, más bien es el medio, para promover desarrollo rural sostenible, a través de acompañamiento técnico agropecuario, monitoreo y evaluación tanto económica como ambiental.

  3. Estudios florísticos y ecológicos sobre las algas de agua dulce de turberas de Tierra del Fuego

    OpenAIRE

    Mataloni, María Gabriela

    1994-01-01

    En esta Tesis Doctoral se realizan diversas investigaciones florísticas y ecológicas sobre las algas de turberas de Sphagnum de la provincia de Tierra Fuego. Para ello se condijeron básicamente dos trabajos. en la primera parte se estudiaron ocho ojos de agua pertenecientes a siete turberas ubicadas en el sur de Tierra del Fuego. En cada una de ellas se muestrearon tanto el fitoplancton del agua libre como las algas que viven asociadas a Sphagnum a lo largo de un gradiente ambiental caracteri...

  4. El Límite a la Protección de las Tierras Indígenas de la Ley 19.253

    Directory of Open Access Journals (Sweden)

    Mario Salamanca Huenchullán

    Full Text Available Este trabajo aborda el tema del límite a la protección de las tierras indígenas, que como una exigencia del interés nacional introduce en la legislación chilena la Ley Indígena 19.253, en su relación con la expropiación para la construcción de obras públicas, que en virtud de la utilidad pública se construyen sobre estas mismas tierras.

  5. Del discurso poblador a la praxis latifundista: la distribución de la tierra pública en la Patagonia

    OpenAIRE

    Bandieri, Susana

    2005-01-01

    Una de las tareas fundamentales cumplidas por el Estado nacional consolidado a partir de 1880 fue la de continuar con las prácticas de los anteriores gobiernos de aplicar una política sistemática de transferencia de tierras públicas a manos privadas a través de la donación, la venta o la recompensa por servicios prestados a la Nación. La concentración de la tierra en pocas manos y la expansión de las grandes propiedades fueron las consecuencias más conocidas de estas políticas, incrementadas ...

  6. El acaparamiento de tierras como proceso dinámico. Las estrategias de los actores en contextos de estancamiento económico

    OpenAIRE

    Carla Gras; Daniel M. Cáceres

    2017-01-01

    Este artículo pretende contribuir a la comprensión de los procesos de acaparamiento de tierras. A partir de un análisis realizado en el norte de Córdoba (Argentina), se sugiere que dicho fenómeno: (a) no es lineal, uniforme ni se incrementa de manera sostenida en el tiempo; y (b) no se limita a la concentración de tierras sino que integra recursos estratégicos (financieros, tecnológicos, gerenciales) que convergen en el objetivo más general de acaparamiento de capital. Analizamos una dinámica...

  7. Bioaccumulation of heavy metals in the earthworms Lumbricus rubellus and Aporrectodea caliginosa in relation to total and available metal concentrations in field soils

    International Nuclear Information System (INIS)

    Hobbelen, P.H.F.; Koolhaas, J.E.; Gestel, C.A.M. van

    2006-01-01

    The aim of this study was to determine important metal pools for bioaccumulation by the earthworms Lumbricus rubellus and Aporrectodea caliginosa in soils with high binding capacity. Cd, Cu and Zn concentrations in soil, pore water and CaCl 2 extracts of soil, in leaves of the plant species Urtica dioica and in earthworms were determined at 15 field sites constituting a gradient in metal pollution. Variations in the Cu and Cd concentrations in L. rubellus and Cu concentrations in A. caliginosa were best explained by total soil concentrations, while variation in Cd concentration in A. caliginosa was best explained by pore water concentrations. Zn concentrations in L. rubellus and A. caliginosa were not significantly correlated to any determined variable. It is concluded that despite low availability, earthworms in floodplain soils contain elevated concentrations of Cu and Cd, suggesting that uptake takes place not only from the soluble metal concentrations. - Earthworms in floodplain soils not only accumulate heavy metals from soluble metal pools

  8. Bioaccumulation of heavy metals in the earthworms Lumbricus rubellus and Aporrectodea caliginosa in relation to total and available metal concentrations in field soils

    Energy Technology Data Exchange (ETDEWEB)

    Hobbelen, P.H.F. [Department of Animal Ecology, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)]. E-mail: phobbelen@usgs.gov; Koolhaas, J.E. [Department of Animal Ecology, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands); Gestel, C.A.M. van [Department of Animal Ecology, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1085, 1081 HV Amsterdam (Netherlands)

    2006-11-15

    The aim of this study was to determine important metal pools for bioaccumulation by the earthworms Lumbricus rubellus and Aporrectodea caliginosa in soils with high binding capacity. Cd, Cu and Zn concentrations in soil, pore water and CaCl{sub 2} extracts of soil, in leaves of the plant species Urtica dioica and in earthworms were determined at 15 field sites constituting a gradient in metal pollution. Variations in the Cu and Cd concentrations in L. rubellus and Cu concentrations in A. caliginosa were best explained by total soil concentrations, while variation in Cd concentration in A. caliginosa was best explained by pore water concentrations. Zn concentrations in L. rubellus and A. caliginosa were not significantly correlated to any determined variable. It is concluded that despite low availability, earthworms in floodplain soils contain elevated concentrations of Cu and Cd, suggesting that uptake takes place not only from the soluble metal concentrations. - Earthworms in floodplain soils not only accumulate heavy metals from soluble metal pools.

  9. Toxicokinetics of metals in the earthworm Lumbricus rubellus exposed to natural polluted soils – relevance of laboratory tests to the field situation

    International Nuclear Information System (INIS)

    Giska, Iwona; Gestel, Cornelis A.M. van; Skip, Borys; Laskowski, Ryszard

    2014-01-01

    The aim of this study was to estimate the bioavailability of essential (Zn, Cu) and non-essential metals (Cd, Pb) to the earthworm Lumbricus rubellus exposed to soils originating from a gradient of metal pollution in Southern Poland. Metal uptake and elimination kinetics were determined and related to soils properties. Experimental results were compared with tissue metal concentrations observed in earthworms from the studied transect. Cd and Pb were intensively accumulated by the earthworms, with very slow or no elimination. Their uptake rate constants, based on 0.01 M CaCl 2 -extractable concentrations in the soils, increased with soil pH. Internal concentrations of Cu and Zn were maintained by the earthworms at a stable level, suggesting efficient regulation of these metals by the animals. The estimated uptake and elimination kinetics parameters enabled fairly accurate prediction of metal concentrations reached within a life span of L. rubellus in nature. - Highlights: • We estimated bioavailability of Cd, Pb, Cu and Zn to the earthworm L. rubellus. • Earthworms intensively accumulated Cd and Pb. • Uptake rate constants of Cd and Pb increased with soil pH. • Earthworms showed efficient regulation of Cu and Zn internal concentrations. • Toxicokinetics was predictive of metal accumulation by earthworms in the field. - Toxicokinetics tests with earthworms are indicative of metal bioavailability in the field

  10. Responses of earthworms (Lumbricus rubellus) to copper and cadmium as determined by measurement of juvenile traits in a specifically designed test system.

    Science.gov (United States)

    Spurgeon, D J; Svendsen, C; Kille, P; Morgan, A J; Weeks, J M

    2004-01-01

    In this study, the effects of two metals, copper and cadmium, on the growth and development of juvenile Lumbricus rubellus were measured in a toxicity test in which individuals were grown in isolation. This design had a number of advantages over traditional test systems for earthworms. Importantly, the test is specifically designed to measure two juvenile traits (survival over and length of the juvenile period) that have been shown to have a high sensitivity for determining population growth rate. The test system also maximizes replication, while allowing time-series-based monitoring of individual growth. For both metals, significant exposure-dependent effects on survival, growth, development time, and (less certainly) maturation weight were observed. Comparisons of the relative toxicity of the two metals indicated different concentration-response relationships. For copper, hormesis was found at low levels, while only at the highest soil concentration tested (10.07 micromol g(-1)) were (severe) toxic effects present. For cadmium, hormesis was also evident at the lowest concentration tested; however, at soil levels above this, a graded concentration-dependent toxic effect was apparent. These differences in the exposure response patterns can be (tentatively) explained in terms of the mechanisms for handling copper (an essential metal for earthworms) and cadmium (a putative nonessential element). The applicability of the test for routine measurement of chemical effects on ecologically relevant juvenile traits is also outlined and future developments are discussed.

  11. Evaluación del efecto insecticida de tierra de diatomeas sobre Triatoma infestans (Hemíptera, Reduviidae

    Directory of Open Access Journals (Sweden)

    Mariana L Bilbao

    2007-04-01

    Full Text Available El Triatoma infestans es el principal vector de la enfermedad de Chagas en Argentina. La tierra de diatomeas (TD es un producto natural que se comercializa actualmente con fines insecticidas y que produce la muerte por deshidratación. Se evaluó la eficacia insecticida de TD al 60% de pureza, proveniente del yacimiento La Iglesiana (San Juan, Argentina sobre ninfas V y adultos de T.infestans. Se ensayaron dos dosis: 112,5 g/m2 (T1 y 225 g/m2 (T2, con cuatro réplicas por tratamiento, con cinco ejemplares, incluyendo los controles (TC en el laboratorio. Se contaron los individuos vivos y muertos durante cinco días. No se encontró diferencias en la mortalidad (ANOVA, p>0,05 en los adultos (T1: 40%, T2: 25% y TC: 30% ni en las ninfas V (T1: 10%, T2: 15% y TC: 10%. Se concluye que la tierra de diatomeas del yacimiento La Iglesiana, en las condiciones de laboratorio evaluadas, no posee capacidad insecticida sobre T.infestans.

  12. Plan de manejo sostenible de tierra para la producción de leche en la UBPC Aguadita, Cienfuegos, Cuba

    Directory of Open Access Journals (Sweden)

    Eligia de la C Cuellar

    Full Text Available Se realizó un estudio en la UBPC Aguadita, del municipio Rodas _provincia Cienfuegos, Cuba_, con el objetivo de elaborar un plan de manejo sostenible del suelo para incrementar la producción de leche. Se utilizó la guía contenida en el manual de procedimientos para la implementación del manejo sostenible de tierra. Los pasos de la guía permitieron concebir una investigación no experimental, de tipo correlacional/múltiple, en la que se utilizaron métodos teóricos y prácticos con sus correspondientes técnicas (entrevistas, encuestas, revisión documental, observación directa; y se realizaron mediciones en el lugar, con la aplicación de diez herramientas metodológicas. Se demostró que la baja producción de leche en la UBPC es causada fundamentalmente por la degradación de los suelos, la mala calidad de los pastos y la deficiente gestión del conocimiento, lo que coincide con la principal barrera para la aplicación del manejo sostenible de tierra. A partir de estos resultados se elaboró el plan de manejo sostenible, como herramienta que contribuye a desarrollar acciones que mitiguen el impacto negativo de la degradación de suelos en el rendimiento lechero de la unidad.

  13. «Propiedad Común de la Tierra», Derechos Humanos y Justicia Global

    Directory of Open Access Journals (Sweden)

    Álvarez, David

    2010-12-01

    Full Text Available After comparing Risse’s conception of Common Property of the Earth (PCT with other theories of global redistribution (Steiner, Pogge or with conceptions of human rights in terms of membership (Cohen, Benhabib, we conclude that PCT as theory of distributive justice defends an unnecessarily low threshold; and as human rights conception doesn’t provide robustness in socioeconomic measures. Finally, the specification of human rights out of global membership cannot be translated into a «right not to be excluded from the new public property» (Sachar. This is so because the mere subsistence condition in human rights does not necessarily imply the condition of independence in the original status of co-owner. Therefore, this contingent derivation of human rights does not meet the transitivity required by its own justification requirements.

    Tras comparar la concepción de Risse de Propiedad Común de la Tierra (PCT con otras alternativas teóricas de redistribución global (Steiner, Pogge o de reformulación de los derechos humanos en términos de membrecía (Cohen, Benhabib, concluimos que PCT, como teoría de justicia distributiva global, defiende un umbral innecesariamente bajo; y como concepción de derechos humanos no fundamenta con robustez las garantías socioeconómicas. Finalmente, la especificación de los derechos humanos a partir de la membrecía global no es traducible a términos de «derecho a no-exclusión de la nueva propiedad pública» (Sachar, ya que la condición de subsistencia de los derechos humanos no implica necesariamente la condición de independencia del estatus de co-propietario original. Así pues, esta derivación contingente de los derechos humanos no cumple la condición de transitividad exigida por sus requisitos internos de justificación.

  14. Mars : a small terrestrial planet

    OpenAIRE

    Mangold, N.; Baratoux, David; Witasse, O.; Encrenaz, T.; Sotin, C.

    2016-01-01

    Mars is characterized by geological landforms familiar to terrestrial geologists. It has a tenuous atmosphere that evolved differently from that of Earth and Venus and a differentiated inner structure. Our knowledge of the structure and evolution of Mars has strongly improved thanks to a huge amount of data of various types (visible and infrared imagery, altimetry, radar, chemistry, etc) acquired by a dozen of missions over the last two decades. In situ data have provided ground truth for rem...

  15. Modelo para evaluar la calidad de las tierras: caso del cultivo de papa

    Directory of Open Access Journals (Sweden)

    Martínez Luis Joel

    2006-06-01

    Hidden="false" UnhideWhenUsed="false" QFormat="true" Name="Intense Emphasis" />

    Dentro de la busqueda de la sostenibilidad y la competitividad de la agricultura, la evaluacion de la calidad de las tierras es un aspecto basico que permite tomar decisiones sobre  las areas mas apropiadas para ubicar los cultivos y sobre los procesos de degradación de las tierras, con el fin de tomar medidas para su manejo y conservacion. En esta investigacion se

  16. Checklist of the Discomycetes (Fungi of Patagonia, Tierra del Fuego and adjacent antarctic areas

    Directory of Open Access Journals (Sweden)

    Irma J. Gamundí

    2004-01-01

    Full Text Available La información brindada en este catálogo consiste en registrar las especies de hongos pertenecientes a los órdenes Cyttariales, Helotiales, Ostropales, Pezizales, Rhytismatales y Thelebolales (Discomycetes coleccionadas en Patagonia, Tierra del Fuego y áreas adyacentes antárticas (Patagonia. Además datos sobre sus organismos asociados fueron localizados, resumidos, validados y editados. Las fuentes de información fueron las exsiccatae depositadas en colecciones de Argentina y otros países y de las publicaciones listadas en la bibliografía. Otros registros derivaron de observaciones de campo sobre material fresco y colecciones de referencia. La información fue acumulada en un sistema computarizado relacional de datos taxonómicos, nomenclaturales, bibliográficos, de distribución geográfica y de observaciones biológicas. Este sistema permite la acumulación de datos paralelos en diferentes idiomas, y distingue la información original de la opinión corriente de lo que puede significar esa información. En la Biological Records Database, 5029 registros fueron creados para observaciones sobre la ocurrencia temporal y espacial de los organismos vivos de la región. De éstos, 2613 corresponden a registros de colecciones de Discomycetes de la Patagonia y Tierra del Fuego, con la siguiente distribución: 1854 para a la Argentina, 687 para Chile y 72 para áreas adyacentes antárticas. Excluyendo los sinónimos, los Discomycetes están representados por 361 especies y taxones subespecíficos (160 géneros, 22 familias y 7 órdenes. Los registros remanentes fueron de organismos asociados con los Discomycetes: 163 animales (8 especies, 8 géneros, 6 familias y 5 órdenes; 2 Chromista; 223 hongos (52 especies, 54 géneros, 26 familias y 13 ódenes; 2028 plantas (159 especies, 122 géneros, 59 familias y 39 órdenes. Cada uno de estos taxones (y cada sinónimo conocido está representado por un registro separado en la Base de Datos Taxon

  17. Organización territorial y distribución de la tierra en la comunidad de San Felipe Otlaltepec, Puebla, México

    Directory of Open Access Journals (Sweden)

    Jesús García Maceda

    2014-01-01

    Full Text Available San Felipe Otlaltepec, una comunidad indígena Popoloca del estado de Puebla, organiza su territorio en secciones, una unidad territorial colonial. Esta organización es la base de la apropiación del territorio urbano y de las tierras agrícolas. Con entrevistas y fotografías aéreas, se construyó un modelo de la conformación original y actual de las viviendas de las secciones y de la apropiación de la tierra, para su comparación. Actualmente, se observa una mezcla de viviendas de diferentes secciones, que no corresponde al arreglo original de las mismas. Situación similar se observó en la distribución de las tierras agrícolas. Estos cambios se deben principalmente a casamientos entre miembros de diferentes secciones, los cuales cambian la posesión de la tierra y la pertenencia a una sección determinada. A pesar de la mezcla de viviendas de diferentes secciones, los entrevistados manifestaron un sentido profundo de pertenencia a la sección a la que pertenecen formalmente.

  18. Preparativos del viaje de Diego de Nicuesa para poblar la Tierra Firme. Sevilla y los mercaderes del comercio atlántico (1509

    Directory of Open Access Journals (Sweden)

    Mena García, Carmen

    2012-12-01

    Full Text Available On these pages we reveal absolutely new aspects of Alonso de Ojeda and Diego de Nicuesa’s expedition to the Tierra Firme. In particular, we pay attention to the preparations carried out by Nicuesa in Seville, whose expenses and mishaps were reflected both in the accounts of Matienzo’s Treasury book and Seville’s notary records. In our research, a trading network emerges with a noticeable predominance of Basque and Genovese merchants interested in the Atlantic trade and who actively participated in the service of the flotilla of Tierra Firme.

    Desvelamos en estas páginas aspectos absolutamente novedosos de la expedición de Alonso de Ojeda y Diego de Nicuesa a la Tierra Firme. En especial, nos preocupamos por investigar los preparativos realizados en solitario por Nicuesa en Sevilla, cuyos gastos y vicisitudes quedaron reflejados tanto en el libro de cuentas del tesorero Matienzo como en los registros notariales hispalenses. Todo un entramado mercantil aflora en nuestra pesquisa con un notorio predominio de los comerciantes vascos y genoveses interesados en el comercio atlántico, que ahora participan activamente al servicio de la flotilla de Tierra Firme.

  19. Profeta en su tierra. Hernando Arias de Ugarte. Vº Arzobispo de Santafé de Bogotá. [Reseña

    OpenAIRE

    Luque-Alcaide, E. (Elisa)

    2009-01-01

    Reseña de: Luis Carlos Mantilla, Profeta en su tierra. Hernando Arias de Ugarte. Vº Arzobispo de Santafé de Bogotá, Academia Colombiana de Historia [Biblioteca de Historia Nacional, Vol. 165] - Universidad San Buenaventura de Medellín, Bogotá 2008, 288 pp.

  20. Representations of Mexican American Migrant Childhood in Rivera's "...y no se lo trago la tierra" and Viramontes's "Under the Feet of Jesus"

    Science.gov (United States)

    Beck, Scott A.; Rangel, Dolores E.

    2009-01-01

    This article gives an analysis of two books: Thomas Rivera's "...y no se lo trago la tierra" and Helena Maria Viramontes's "Under the Feet of Jesus". The two books are strong and important literary texts that stand in close relation to each other. Both texts treat the subject of migrant childhood by affirming central themes of Chicano literature.…

  1. Expansión estatal, política de tierras y desarrollo de la repartición topográfica en Buenos Aires, siglo XIX

    Directory of Open Access Journals (Sweden)

    Valeria Araceli D'Agostino

    2014-11-01

    Full Text Available Este artículo aborda la política de tierras del Estado provincial bonaerensey su relación con el proceso de conformación de la repartición topográfi ca,tomando como punto de partida el contexto de expansión territorial y deincorporación de tierras a la economía provincial abierto luego de la rupturadel vínculo colonial. Se considera que la centralidad de la problemática dela tierra en este contexto impulsó la temprana organización de la reparticióndestinada a: realizar las tareas de reconocimiento, mensura y delimitación delos territorios de dominio público y privado, elaborar un catastro territorial,controlar el traspaso de tierras públicas a particulares, perfeccionar el trazadode pueblos y ejidos y regular las actividades de los agentes encargados de lasmismas, entre otras.

  2. Mauricio Onetto Pavez (2017. Temblores de tierra en el jardín del Edén. Desastre, memoria e identidad. Chile, siglos XVI-XVIII

    Directory of Open Access Journals (Sweden)

    Melina López Calvo

    2017-12-01

    Full Text Available Reseña bibliográfica: Mauricio Onetto Pavez (2017. Temblores de tierra en el jardín del Edén. Desastre, memoria e identidad. Chile, siglos XVI-XVIII. Ediciones de la Dirección de Bibliotecas, Archivos y Museos. 2017. Santiago, Chile. El patrimonio de Chile. Centro de investigaciones Diego Barros Arana

  3. CONFLICTOS POR TIERRAS EN LOS "PUEBLOS DE INDIOS" DE CÓRDOBA. EL PUEBLO DE SAN MARCOS ENTRE FINES DEL SIGLO XVII Y PRINCIPIOS DEL SIGLO XIX

    Directory of Open Access Journals (Sweden)

    Sonia Tell

    2012-01-01

    Full Text Available En este trabajo se abordan los conflictos por tierras de “pueblos de indios” de Córdoba en el siglo XVIII a partir de un estudio de caso: el del pueblo de San Marcos. En base a un pleito que se prolongó por cuatro décadas (entre 1769 y 1809, se reconstruyen las estrategias de la elite local para legalizar la usurpación de tierras de los pueblos de indios y las estrategias indígenas para recuperarlas, basándose en el título de la demarcación y asignación de tierras de reducción realizada en 1694 por orden del visitador Luján de Vargas y en el apoyo de los funcionarios de la Real Audiencia de Buenos Aires. Asimismo, se reconstruyen algunas características de la tenencia de la tierra, del sistema de autoridades y de la organización comunitaria de las actividades productivas, a fin de reevaluar los planteos realizados en estudios previos sobre la desestructuración avanzada de los pueblos de indios de la jurisdicción de Córdoba a fines de la colonia.

  4. La usurpación de tierras comunales y baldíos en Guadalajara durante la segunda mitad del siglo XV

    OpenAIRE

    Plaza de Agustín, Javier

    2015-01-01

    La ciudad de Guadalajara, desde su incorporación a la corona castellana, se constituyó como cabeza de un amplio territorio de realengo sobre el que ejercía su jurisdicción. Este alfoz se componía de considerables extensiones de tierras de uso comu

  5. Conflictos en torno a las tierras comunales en el término de Plasencia hacia finales de la Edad Media

    OpenAIRE

    García Oliva, María Dolores

    2017-01-01

    En este trabajo se analizan los conflictos surgidos en torno a las tierras comunales en el término de Plasencia a finales del Medievo. Para entonces, los avances realizados en la colonización del espacio y la extensión de las dehesas de propiedad parti

  6. Regulación en el uso de la tierra con fines preventivos en los alrededores del cuadrante de la antigua comunidad de Cinchona, Alajuela, Costa Rica

    Directory of Open Access Journals (Sweden)

    Esquivel Valverde, Lidier

    2011-07-01

    Full Text Available La regulación del uso de la tierra permite establecer cuales lugares son aptas para el establecimiento de zonas habitacionales, comercios, industria, actividades agrícolas, actividades turísticas, entre otras, evitando incrementar la vulnerabilidad física o ambiental. El presente artículo se basa en un estudio realizado a la comunidad de Cinchona a raíz del sismo del año 2009, el cual, por las características topográficas y geológicas de la región, generó una cantidad alta de daños a la infraestructura y pérdida de vidas humanas, lo que propició la elaboración de una herramienta técnica normativa que regulara el uso de la tierra en esa zona. La investigación consideró aspectos como el uso de la tierra antes del sismo, tenencia de la tierra, producción agropecuaria, valor de la tierra, pendientes de terreno, geomorfología, capacidad de uso de la tierra, aguas subterráneas, zonas de vida y áreas silvestres y por último las amenazas más relevantes. Como resultado del estudio se presenta en el artículo un resumen de la regulación de tierra propuesta, la cual comprende el sector de Vieja Cinchona (zona devastada por el sismo y las microcuencas cercanas Land use regulations allow to identify suitable places to establish housing, commerce, industry, agricultural activities, and tourism, among others, avoiding to increase physical or environmental vulnerability. This article is based on a study developed at the Cinchona community after the 2009 earthquake, which due to the topographic and geological characteristics generated a lot of damages to infrastructures and losses of human lives. In this context, a normative technical tool was developed to regulate the land use in the zone. The investigation considered aspects such as land use before the earthquake, land possession, farming production, land value, land slopes, geomorphology, land use capacity, underground water, wild life areas and most relevant threats. As a result of

  7. Historia y memoria campesina: silencios y representaciones sobre la lucha por la tierra y la represión en Ongoy

    Directory of Open Access Journals (Sweden)

    Guido Chati

    2015-01-01

    Full Text Available Este artículo sostiene que hay espacios sociales en Perú donde se producen memorias alternativas sobre la violencia política que tuvo lugar entre 1980 y 2000. En Andahuaylas, Apurímac, las narrativas recurrentes hablan acerca de la servidumbre en la hacienda, de la movilización campesina por la restitución de sus tierras, la ocupación de tierras y sobre su violenta represión. Existe esta memoria victoriosa respecto de la ocupación de la tierra, al lado de una memoria de victimización respecto de la guerra interna. Sin embargo, esas representaciones han sido silenciadas a través de estudios oficiales sobre la memoria, que están tan de moda. En Ongoy, Andahuaylas, bajo la apariencia de un conflicto entre las comunidades y hacienda, se encuentran prácticas políticas campesinas en relación con el Estado. Los campesinos desarrollan redes con las instituciones del Estado, sindicatos, estudiantes, inmigrantes, partidos políticos y otros en busca de la restitución de sus tierras. Reúnen documentos que utilizan como apoyo de su memoria y de su precedencia en el territorio. Ellos muestran que la lucha por la tierra que relativamente termina en 1963 con la ocupación de la tierra, la masacre de los campesinos y la represión, tiene orígenes coloniales. Son historias y recuerdos que reconstruyen la lucha por la tierra como un acto heroico y se superponen con otras representaciones más recientes de la violencia política. Para analizar el proceso, reconstruyo lo ocurrido en Ongoy entre 1960 y 1969 en diálogo con los documentos que los campesinos reunieron y con los testimonios de los actores sobre la forma en que se da una lectura posterior a la violencia política.

  8. Evaluación de la tasa de infiltración en tierras agrícolas, forestales y de pastoreo en la subcuenca del río Shullcas

    Directory of Open Access Journals (Sweden)

    Guillermo Carlos Gómez

    2014-06-01

    Full Text Available Objetivos: Evaluar y determinar el uso del suelo con mayor tasa de infiltración en la subcuenca del río Shullcas en Huancayo. Métodos: Se desarrolló una investigación básica con diseño correlacional. Los usos actuales de la tierra fueron identificadas y demarcadas, según la normativa peruana de clasificación de tierras por su capacidad de uso mayor; en estas zonas se seleccionó 31 puntos de muestreo al azar usando las herramientas de software ArcGIS, en los que se midieron la infiltración empleando infiltrómetros de doble anillo, se registraron los tipos de cobertura vegetal y se tomaron muestras de suelo para analizar sus contenidos de arcilla, arena, limo y humedad; asimismo densidad aparente y porosidad en laboratorio. Resultados: Las tasas de infiltración promedio, según el tipo de uso de tierras, fueron: 14,04 cm/h para las tierras forestales; 12,42 cm/h para las tierras agrícolas y 2,07 cm/h para las tierras de pastoreo; además, solo el 12,63% de la subcuenca del río Shullcas tiene infiltración mayor a 0,2 cm/h. Conclusiones: No existe diferencia estadística significativa entre la tasa de infiltración de tierras forestales y agrícolas, pero si existe diferencias de la tasa de infiltración de tierras forestales y agrícolas respecto a la tasa de infiltración de tierras de pastoreo.

  9. El movimiento de los trabajadores rurales sin tierra y la reforma agraria en Brasil

    Directory of Open Access Journals (Sweden)

    Lorenzo FERNÁNDEZ FRANCO

    2009-11-01

    Full Text Available RESUMEN: Este artículo, es un primer avance, de carácter exploratorio, de una investigación más amplia que el autor está llevando a cabo sobre el mismo tema. Centrado en el "Movimiento de los Trabajadores Rurales sin Tierra", habitualmente identificado en Brasil por las siglas MST, se contempla dicho movimiento social desde sus orígenes más remotos, al final de los años 50, hasta nuestros días situándolo, por un lado, en las transformaciones políticas y en parte sociales, y en el largo y lento proceso de una reforma agraria inconclusa, por otro. De forma descriptiva, se desarrollan, en un primer paso, los antecedentes, proceso de constitución, etapas y estructura agraria brasileña, se plantea de forma suscinta la problemática de la reforma agraria. Con estas consideraciones preliminares, siguiendo casi literalmente la formulación del propio MST, se exponen, con mayor amplitud, los objetivos y características de la Reforma Agraria desde la perspectiva de los propios trabajadores rurales. Asimismo, aunque de forma más esquemática y en base a los datos oficiales, se plantean las directrices, metas y algunas de las realizaciones del Gobierno de Fernando H. Cardoso sobre dicha reforma. En definitiva, con este artículo, se pretenden establecer las bases y los ejes analíticos necesarios para una investigación más amplia y comprensiva de este fenómeno social de masas que va más allá de la propia realidad de injusticia que se está viviendo en el mundo rural brasileño y que está contando también con un amplio y sorprendente apoyo de sectores urbanos de la población brasileña.ABSTRACT: This article is an introductory and exploratory advance of a more extensive investigation that the author is carrying out on the same subject. The research is centred on the "Movement of the Rural Workers without Land", which is ussually identified in Brazil with the initials MST. This social movement is analyzed since its remotest origins, the

  10. Terrestrial ecosystems under warmer and drier climates

    Science.gov (United States)

    Pan, Y.

    2016-12-01

    Future warmer and drier climates will likely affect many of the world's terrestrial ecosystems. These changes will fundamentally reshape terrestrial systems through their components and across organization levels. However, it is unclear to what extent terrestrial ecosystems would be resilient enough to stay put to increased temperature and water stress by only adjusting carbon fluxes and water balances? And to what extent it would reach the thresholds at which terrestrial ecosystems were forced to alter species compositions and ecosystem structures for adapting to newer climates? The energy balance of terrestrial ecosystems link thermal and water conditions to defines terrestrial carbon processes and feedbacks to climate, which will inevitably change under warmer and drier climates. Recent theoretical studies provide a new framework, suggesting that terrestrial ecosystems were capable of balancing costs of carbon gain and water transport to achieve optimums for functioning and distribution. Such a paradigm is critical for understanding the dynamics of future terrestrial ecosystems under climate changes, and facilitate modeling terrestrial ecosystems which needs generalized principles for formulating ecosystem behaviors. This study aims to review some recent studies that explore responses of terrestrial ecosystems to rather novel climate conditions, such as heat-induced droughts, intending to provide better comprehension of complex carbon-water interactions through plants to an ecosystem, and relevant factors that may alleviate or worsen already deteriorated climates such as elevated CO2 and soil conditions.

  11. Groundwater and Terrestrial Water Storage

    Science.gov (United States)

    Rodell, Matthew; Chambers, Don P.; Famiglietti, James S.

    2014-01-01

    Terrestrial water storage (TWS) comprises groundwater, soil moisture, surface water, snow,and ice. Groundwater typically varies more slowly than the other TWS components because itis not in direct contact with the atmosphere, but often it has a larger range of variability onmultiannual timescales (Rodell and Famiglietti, 2001; Alley et al., 2002). In situ groundwaterdata are only archived and made available by a few countries. However, monthly TWSvariations observed by the Gravity Recovery and Climate Experiment (GRACE; Tapley et al.,2004) satellite mission, which launched in 2002, are a reasonable proxy for unconfinedgroundwater at climatic scales.

  12. La villa de Benavente y su tierra a fines del siglo XV y durante la primera mitad del siglo XVI

    Directory of Open Access Journals (Sweden)

    Severiano HERNÁNDEZ

    2009-12-01

    Full Text Available El estudio de los núcleos urbanos se ha constituido como una de las cuestiones clave de la formación social feudal y ello en un entorno social con un marcado cariz rural, en el que la tierra aparece como una realidad omnipresente. En relación con estos planteamientos —indicios de una problemática amplia y sugestiva— el objetivo del presente artículo es, únicamente, el de acercarnos al conocimiento general de algunos aspectos de la organización y de la vida cotidiana de un concejo castellano-leonés de señorío: el concejo de Benavente a fines del siglo XV y durante los primeros años del siglo XVI.

  13. Structural and functional changes in Nothofagus pumilio forests along an altitudinal gradient in Tierra del Fuego, Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Barrera, M.D.; Frangi, J.L.; Perdomo, M.H. [Univ. Nacional de La Plata (Argentina). Facultad de Ciencias Agrarias y Forestales; Richter, L.L.; Pinedo, L.B. [CADIC, Ushuaia (Argentina)

    2000-04-01

    Structural (density, height, basal area, above-ground tree biomass, leaf area index) and functional (leaf phenology, growth rate, fine litter fall, leaf decomposition) traits were quantified in four mature forests of Notofagus pumilio (lenga) along an altitudinal sequence in Tierra del Fuego, Argentina. Three erect forest stands at 220, 440 and 540 m and a krummholz stand at 640 m a.s.l. were selected. Along the altitudinal sequence, stem density increased while DBH, height, biomass, leaf-size and growth period, mean growth rate and decay rate decreased. Dead stems increased and basal area and fine-litter fall decreased with an increase in elevation among erect forests, but these trends inverted at krummholz. We suggest that krummholz is not only a morphological response to the adverse climate but is also a life form with functional advantages.

  14. Los carteles del periódico Tierra: construcción de la identidad del obrero colombiano

    Directory of Open Access Journals (Sweden)

    Victoria Eugenia Peters

    2014-01-01

    Full Text Available Este trabajo pretende hacer una revisión del periódico Tierra, órgano central del Partido Comunista, en el periodo comprendido entre 1932 y 1939. Esta publicación se configuró como dispositivo de enunciación articulado con las actividades de un proyecto político que empezó a surgir en la década de 1930. La revisión incorpora una mirada analítica de algunas de las imágenes de dicho periódico, realizadas en xilografía y aplicadas a carteles políticos.

  15. El acaparamiento de las tierras a gran escala en el mundo. El papel de las firmas multinacionales (Internacional)

    OpenAIRE

    Perdriault, Mathieu

    2011-01-01

    En los años 2007 y 2008, los medios de comunicación se hicieron eco, de manera creciente, de la adquisición –por intereses públicos o privados–, de los derechos de propiedad sobre grandes extensiones de tierra, especialmente en África, América y Europa del Este. Los miembros de la ONG GRAIN están entre los primeros que han observado la proliferación de artículos de prensa sobre este tema. Se los presentó ante los ojos de la opinión pública mundial, en octubre del 2008, mediante una recopilac...

  16. Effect of resource spatial correlation and hunter-fisher-gatherer mobility on social cooperation in Tierra del Fuego.

    Directory of Open Access Journals (Sweden)

    José Ignacio Santos

    Full Text Available This article presents an agent-based model designed to explore the development of cooperation in hunter-fisher-gatherer societies that face a dilemma of sharing an unpredictable resource that is randomly distributed in space. The model is a stylised abstraction of the Yamana society, which inhabited the channels and islands of the southernmost part of Tierra del Fuego (Argentina-Chile. According to ethnographic sources, the Yamana developed cooperative behaviour supported by an indirect reciprocity mechanism: whenever someone found an extraordinary confluence of resources, such as a beached whale, they would use smoke signals to announce their find, bringing people together to share food and exchange different types of social capital. The model provides insight on how the spatial concentration of beachings and agents' movements in the space can influence cooperation. We conclude that the emergence of informal and dynamic communities that operate as a vigilance network preserves cooperation and makes defection very costly.

  17. Comparative Climatology of Terrestrial Planets

    Science.gov (United States)

    Mackwell, Stephen J.; Simon-Miller, Amy A.; Harder, Jerald W.; Bullock, Mark A.

    Public awareness of climate change on Earth is currently very high, promoting significant interest in atmospheric processes. We are fortunate to live in an era where it is possible to study the climates of many planets, including our own, using spacecraft and groundbased observations as well as advanced computational power that allows detailed modeling. Planetary atmospheric dynamics and structure are all governed by the same basic physics. Thus differences in the input variables (such as composition, internal structure, and solar radiation) among the known planets provide a broad suite of natural laboratory settings for gaining new understanding of these physical processes and their outcomes. Diverse planetary settings provide insightful comparisons to atmospheric processes and feedbacks on Earth, allowing a greater understanding of the driving forces and external influences on our own planetary climate. They also inform us in our search for habitable environments on planets orbiting distant stars, a topic that was a focus of Exoplanets, the preceding book in the University of Arizona Press Space Sciences Series. Quite naturally, and perhaps inevitably, our fascination with climate is largely driven toward investigating the interplay between the early development of life and the presence of a suitable planetary climate. Our understanding of how habitable planets come to be begins with the worlds closest to home. Venus, Earth, and Mars differ only modestly in their mass and distance from the Sun, yet their current climates could scarcely be more divergent. Our purpose for this book is to set forth the foundations for this emerging science and to bring to the forefront our current understanding of atmospheric formation and climate evolution. Although there is significant comparison to be made to atmospheric processes on nonterrestrial planets in our solar system — the gas and ice giants — here we focus on the terrestrial planets, leaving even broader comparisons

  18. Estado y territorio: aportes, desafíos y tensiones en torno a los problemas de tierra en San Juan

    Directory of Open Access Journals (Sweden)

    Margarita Moscheni Bustos

    2015-06-01

    Full Text Available RESUMEN La disputa por la tierra se ha convertido en un tema relevante para la política argentina en el siglo XX. Poseedores históricos, propietarios y desposeídos son los actores que participan en la trama. Atravesando el juego, se encuentra el Estado en sus distintos niveles, que con cierta autonomía relativa, regula a favor de unos y en detrimento de otros. Este trabajo se propone aportar datos empíricos sobre algunas tensiones territoriales en la provincia de San Juan y el rol del Estado y sus contradicciones en los distintos niveles. El caso gira en torno a la disputa por la tierra, generando tensiones políticas entre propiedad privada y propiedad comunitaria, o entre el derecho civil y los derechos emanados de la Constitución Nacional, los Tratados Internacionales y la Ley de Bosques Nativos N° 26.331. ABSTRACT The fight about lands has been became in a relevant situation for the argentine politics in the 20th century, the historic owners, and dispossessed are the most important actors. The state through its different levels has a certain kind of autonomy and regulate and take actions which tend to favor some social groups and damage others. In this work is proposed give some empirical facts about territorial tensions in the province of San Juan, its role and contradictions in its different levels. The case revolves around the land dispute, generating political tensions between private property and communal property, or between civil law and rights arising out of the National Constitution, international treaties and Native Forest Law, No. 26.331.

  19. Long-range Receiver Function Profile of Crustal and Mantle Discontinuities From the Aleutian Arc to Tierra del Fuego

    Science.gov (United States)

    Spieker, Kathrin; Rondenay, Stéphane; Sawade, Lucas

    2016-04-01

    The Circum-Pacific belt, also called the Pacific Ring of Fire, is the most seismically active region on Earth. Multiple plate boundaries form a zone characterized by frequent volcanic eruptions and seismicity. While convergent plate boundaries such as the Peru-Chile trench dominate the Circum-Pacific belt, divergent and transform boundaries are present as well. The eastern section of the Circum-Pacific belt extends from the Aleutian arc, through the Cascadia subduction zone, San Andreas Fault, middle America trench and the Andean margin down to Tierra del Fuego. Due to the significant hazards posed by this tectonic activity, the region has been densely instrumented by thousands of seismic stations deployed across fifteen countries, over a distance of more than 15000 km. Various seismological studies, including receiver function analyses, have been carried out to investigate the crustal and mantle structure beneath local segments of the eastern Circum-Pacific belt (i.e., at ~100-500 km scale). However, to the best of our knowledge, no study to date has ever attempted to combine all available seismic data from the eastern Circum-Pacific belt to generate a continuous profile of seismic discontinuities extending from the Aleutians to Tierra del Fuego. Here, we use results from the "Global Imaging using Earthquake Records" (GLImER) P-wave receiver function database to create a long-range profile of crustal and upper mantle discontinuities across the entire eastern portion of the Circum-Pacific belt. We image intermittent crustal and mantle discontinuities along the profile, and examine them with regard to their behaviour and properties across transitions between different tectonic regimes.

  20. [Distribution patterns of canopy and understory tree species at local scale in a Tierra Firme forest, the Colombian Amazonia].

    Science.gov (United States)

    Barreto-Silva, Juan Sebastian; López, Dairon Cárdenas; Montoya, Alvaro Javier Duque

    2014-03-01

    The effect of environmental variation on the structure of tree communities in tropical forests is still under debate. There is evidence that in landscapes like Tierra Firme forest, where the environmental gradient decreases at a local level, the effect of soil on the distribution patterns of plant species is minimal, happens to be random or is due to biological processes. In contrast, in studies with different kinds of plants from tropical forests, a greater effect on floristic composition of varying soil and topography has been reported. To assess this, the current study was carried out in a permanent plot of ten hectares in the Amacayacu National Park, Colombian Amazonia. To run the analysis, floristic and environmental variations were obtained according to tree species abundance categories and growth forms. In order to quantify the role played by both environmental filtering and dispersal limitation, the variation of the spatial configuration was included. We used Detrended Correspondence Analysis and Canonical Correspondence Analysis, followed by a variation partitioning, to analyze the species distribution patterns. The spatial template was evaluated using the Principal Coordinates of Neighbor Matrix method. We recorded 14 074 individuals from 1 053 species and 80 families. The most abundant families were Myristicaceae, Moraceae, Meliaceae, Arecaceae and Lecythidaceae, coinciding with other studies from Northwest Amazonia. Beta diversity was relatively low within the plot. Soils were very poor, had high aluminum concentration and were predominantly clayey. The floristic differences explained along the ten hectares plot were mainly associated to biological processes, such as dispersal limitation. The largest proportion of community variation in our dataset was unexplained by either environmental or spatial data. In conclusion, these results support random processes as the major drivers of the spatial variation of tree species at a local scale on Tierra Firme

  1. Inferencias paleodietarias mediante isótopos estables en restos óseos humanos provenientes de Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Schinder, Gala

    2003-01-01

    Full Text Available Las actuales lineas de acción vinculadas al uso de isótopos estables en la Isla Grande de Tierra del Fuego están orientándose a acotar factores de variación (especialmente la variación espacial y temporal y al cruce con otras lineas de evidencias como los estilos de vida. A partir de la ocupación europea en el Siglo XVIII se modificó el estilo de vida de las poblaciones históricas de la región. El presente trabajo tiene como objetivos explorar la variabilidad en cuanto al tipo de recursos consurnidos por hombres y mujeres a partir de la información isotópica obtenida de huesos de individuos provenientes de diferentes sectores geográficos (Norte, Sudeste y Beagle y la determinación de la composición de la dieta en términos de contenido proteico. Los datos isotópicos se complementaron con información etnográfica. El análisis Kruskal-Wallis sugiere que existen diferencias significativas entre los diferentes sectores geográficos, pero no se registraron diferencias significativas entre hombres y mujeres. Asimismo, los isótopos indican que los individuos del Sudeste consumían preferentemente dietas más ricas en proteínas que sus vecinos del norte de la Isla. En los últimos años, ha crecido el interé por los estudios orientados al análisis de la división sexual del trabajo en sociedades cazadoras recolectoras. Este trabajo constituye un primer aporte para evaluar la variabilidad en cuanto a las diferencias en la obtención de recursos entre sexos y el tipo de dieta en individuos históricos de Tierra del Fuego.

  2. El Hidróxido de Calcio y los bloques de tierra comprimida, alternativa sostenible de construcción

    Directory of Open Access Journals (Sweden)

    Rubén Salvador Roux Gutiérrez

    2012-01-01

    Full Text Available En la actualidad, en nuestro país se hace mención a que existen una serie de problemas con los programas de vivienda, aún cuando se ha reducido el déficit de vivienda o que se han construido c ada año más viviendas en beneficio de las personas de bajos ingresos. Topelson (2011 el presente artículo describe un estudio sobre una alternativa sustentable de edificación y a la vez pretende demostrar las ventajas del uso del hidróxido de cal y los bl oques de tierra comprimida (BTC, para la edificación de vivienda y así poder reducir las emisones de CO 2 emitidas por los procesos constructivos convenci o nales El presente artículo trata dos materiales elementales en los procesos constructivos de las viv iendas, por un lado se realizá el estudio químico de los morteros cal – arena que se utilizán para el pegado de los mampuestos y los revoques, con la finalidad de determinar la absorción de CO 2 y por otra parte se hace el estudio mecánicos de un materia l alternativo para el uso de muros de carga como son los Bloques de Tierra Comprimida estabilizados con cal, por último se hace un comparativo entre estos materiales alternativos y los convencionales con relación a las emisones de CO2.

  3. Los pueblos originarios y la lucha por la tierra. Límites y posibilidades para resistir desde el derecho

    Directory of Open Access Journals (Sweden)

    Gabriela Álvarez

    2015-03-01

    Full Text Available La profundización del “modelo agroindustrial” en nuestro país tiene serias implicancias socio-económicas en diversas regiones. Una de las más importantes, y la que nos interesa resaltar en este trabajo, es la expulsión de las comunidades originarias de sus territorios como consecuencia de la concentración de la tierra en manos de quienes desarrollan determinadas actividades productivas. Frente a esta situación, las comunidades originarias despliegan distintas estrategias de resistencia entre las cuales se encuentra la exigencia de la implementación de aquellas normativas específicas que garantizan sus derechos fundamentales. En este trabajo, nos proponemos abordar el lugar que ocupa el derecho en las estrategias de resistencia de las comunidades indígenas desde una perspectiva socio-jurídica crítica. En este sentido, nos interesa enmarcar nuestro análisis en un debate teórico más amplio sobre la relación entre derecho y cambio social. Para ello revisaremos algunas perspectivas teóricas que reflexionan sobre los orígenes del derecho moderno y su rol como instrumento de dominación y control social, buscando comprender cuáles son las posibilidades y los límites que tienen las comunidades originarias para vehiculizar sus demandas a través del derecho oficial. Asimismo, analizamos un caso empírico a través del cual buscamos operacionalizar los debates teóricos, y comprender cuál es el rol del derecho en la judicialización de la problemática de la tierra.

  4. Terrestrial Zone Exoplanets and Life

    Science.gov (United States)

    Matthews, Brenda

    2018-01-01

    One of the most exciting results from ALMA has been the detection of significant substructure within protoplanetary disks that can be linked to planet formation processes. For the first time, we are able to observe the process of assembly of material into larger bodies within such disks. It is not possible, however, for ALMA to probe the growth of planets in protoplanetary disks at small radii, i.e., in the terrestrial zone, where we expect rocky terrestrial planets to form. In this regime, the optical depths prohibit observation at the high frequencies observed by ALMA. To probe the effects of planet building processes and detect telltale gaps and signatures of planetary mass bodies at such small separations from the parent star, we require a facility of superior resolution and sensitivity at lower frequencies. The ngVLA is just such a facility. We will present the fundamental science that will be enabled by the ngVLA in protoplanetary disk structure and the formation of planets. In addition, we will discuss the potential for an ngVLA facility to detect the molecules that are the building blocks of life, reaching limits well beyond those reachable with the current generation of telescopes, and also to determine whether such planets will be habitable based on studies of the impact of stars on their nearest planetary neighbours.

  5. Riparian vegetation in the alpine connectome: Terrestrial-aquatic and terrestrial-terrestrial interactions.

    Science.gov (United States)

    Zaharescu, Dragos G; Palanca-Soler, Antonio; Hooda, Peter S; Tanase, Catalin; Burghelea, Carmen I; Lester, Richard N

    2017-12-01

    Alpine regions are under increased attention worldwide for their critical role in early biogeochemical cycles, their high sensitivity to environmental change, and as repositories of natural resources of high quality. Their riparian ecosystems, at the interface between aquatic and terrestrial environments, play important geochemical functions in the watershed and are biodiversity hotspots, despite a harsh climate and topographic setting. With climate change rapidly affecting the alpine biome, we still lack a comprehensive understanding of the extent of interactions between riparian surface, lake and catchment environments. A total of 189 glacial - origin lakes were surveyed in the Central Pyrenees to test how key elements of the lake and terrestrial environments interact at different scales to shape riparian plant composition. Secondly, we evaluated how underlying ecotope features drive the formation of natural communities potentially sensitive to environmental change and assessed their habitat distribution. At the macroscale, vegetation composition responded to pan-climatic gradients altitude and latitude, which captured in a narrow geographic area the transition between large European climatic zones. Hydrodynamics was the main catchment-scale factor connecting riparian vegetation with major water fluxes, followed by topography and geomorphology. Lake sediment Mg and Pb, and water Mn and Fe contents reflected local influences from mafic bedrock and soil water saturation. Community analysis identified four keystone ecosystems: (i) damp ecotone, (ii) snow bed-silicate bedrock, (iii) wet heath, and (iv) calcareous substrate. These communities and their connections with ecotope elements could be at risk from a number of environmental change factors including warmer seasons, snow line and lowland species advancement, increased nutrient/metal input and water level fluctuations. The results imply important natural terrestrial-aquatic linkages in the riparian environment

  6. Construcción sismorresistente en tierra: la gran experiencia contemporánea de la Pontificia Universidad Católica del Perú

    Directory of Open Access Journals (Sweden)

    Blondet, M.

    2011-09-01

    Full Text Available In many developing countries the most common alternative for dwelling construction is building with earth because the material is abundant and cheap. The quality of most traditional earthen construction is very low, because it is done informally, with little or no technical assistance. In seismic areas where earthen construction is common, every time an earthquake occurs, many dwellings collapse, causing considerable economic losses and tragic injuries and deaths. The professional and academic communities in some seismic countries have not remained indifferent to this important problem. Researchers at the Catholic University of Peru (PUCP have been investigating on the construction of earthen buildings in seismic areas for about 40 years and have obtained invaluable results. This article describes the evolution of the knowledge generated at PUCP of reinforced earth, a material composed of earth and compatible reinforcements, with which it is possible to build seismic-resistant constructions.

    En muchos países en vías de desarrollo la alternativa de vivienda más común es la construcción con tierra, pues el material es abundante y barato. La construcción tradicional de viviendas de tierra se realiza informalmente, sin asesoría técnica. Por ello, la calidad de estas construcciones es generalmente muy baja. En zonas sísmicas donde se construye con tierra, cada vez que ocurre un terremoto colapsan muchas construcciones de este material, causando considerables pérdidas económicas y lamentables pérdidas de vidas. Las comunidades académicas y profesionales de algunos países sísmicos no han permanecido impasibles frente a esta grave situación. En el Perú, investigadores de la Pontificia Universidad Católica del Perú (PUCP han venido investigando la construcción con tierra en áreas sísmicas desde hace cerca 40 años y han obtenido invalorables resultados. Este artículo describe la evolución del conocimiento generado en la

  7. El proyecto de restitución de tierras en Colombia: ¿ilustración de la fuerza civilizadora de la hipocresía?

    Directory of Open Access Journals (Sweden)

    Maria Paula Saffon

    2010-12-01

    Full Text Available El presente artículo ofrece una interpretación teórica acerca de las disposiciones sobre restitución de tierras contenidas en la famosa “Ley de Víctimas”, la cual fue debatida en el Congreso colombiano en el año 2008. El proyecto de ley preveía mecanismos específicos encaminados a garantizar la restitución de tierras a las víctimas del conflicto armado colombiano. En su momento, el proyecto de ley fue respaldado por los principales actores políticos del país, incluyendo el gobierno y las élites que lo apoyaban, por un lado, y las organizaciones de víctimas y de derechos humanos y los grupos de oposición, por el otro. El hecho de que todos los actores políticos del país estuviesen considerando seriamente la posibilidad de restituir las tierras a las víctimas del conflicto armado colombiano parecía indicar la existencia de un consenso entre actores políticos cuyas posiciones normalmente están enfrentadas, sobre un tema que tradicionalmente ha generado altos niveles de polarización. Le existencia de dicho consenso es desconcertante porque no parece corresponder ni a los intereses ni a la visión de justicia de dichos actores políticos, y además porque la restitución de tierras enfrenta enormes dificultades tanto prácticas como normativas, lo que indica que posiblemente no sea la mejor alternativa para enfrentar la problemática de distribución de tierras en Colombia. El artículo concluye que el respaldo dado por todos los actores al principio de justicia restaurativa podría llevar a su efectiva realización, y consiguientemente generar un resultado que a pesar de (o quizás por no ser intencional, podría contribuir sustancialmente a resolver el problema de la desigual distribución de tierras en Colombia

  8. Terrestrial atmosphere, water and astrobiology

    Directory of Open Access Journals (Sweden)

    Coradini M.

    2010-12-01

    Full Text Available Primitive life, defined as a chemical system capable to transfer its molecular information via self-replication and also capable to evolve, originated about 4 billion years ago from the processing of organic molecules by liquid water. Terrestrial atmosphere played a key role in the process by allowing the permanent presence of liquid water and by participating in the production of carbon-based molecules. Water molecules exhibit specific properties mainly due to a dense network of hydrogen bonds. The carbon-based molecules were either home made in the atmosphere and/or in submarine hydrothermal systems or delivered by meteorites and micrometeorites. The search for possible places beyond the earth where the trilogy atmosphere/water/life could exist is the main objective of astrobiology. Within the Solar System, exploration missions are dedicated to Mars, Europa, Titan and the icy bodies. The discovery of several hundreds of extrasolar planets opens the quest to the whole Milky Way.

  9. Extreme solar-terrestrial events

    Science.gov (United States)

    Dal Lago, A.; Antunes Vieira, L. E.; Echer, E.; Balmaceda, L. A.; Rockenbach, M.; Gonzalez, W. D.

    2017-10-01

    Extreme solar-terrestrial events are those in which very energetic solar ejections hit the earth?s magnetosphere, causing intense energization of the earth?s ring current. Statistically, their occurrence is approximately once per Gleissberg solar cycle (70-100yrs). The solar transient occurred on July, 23rd (2012) was potentially one of such extreme events. The associated coronal mass ejection (CME), however, was not ejected towards the earth. Instead, it hit the STEREO A spacecraft, located 120 degrees away from the Sun-Earth line. Estimates of the geoeffectiveness of such a CME point to a scenario of extreme Space Weather conditions. In terms of the ring current energization, as measured by the Disturbance Storm-Time index (Dst), had this CME hit the Earth, it would have caused the strongest geomagnetic storm in space era.

  10. Traumatic insemination in terrestrial arthropods.

    Science.gov (United States)

    Tatarnic, Nikolai J; Cassis, Gerasimos; Siva-Jothy, Michael T

    2014-01-01

    Traumatic insemination is a bizarre form of mating practiced by some invertebrates in which males use hypodermic genitalia to penetrate their partner's body wall during copulation, frequently bypassing the female genital tract and ejaculating into their blood system. The requirements for traumatic insemination to evolve are stringent, yet surprisingly it has arisen multiple times within invertebrates. In terrestrial arthropods traumatic insemination is most prevalent in the true bug infraorder Cimicomorpha, where it has evolved independently at least three times. Traumatic insemination is thought to occur in the Strepsiptera and has recently been recorded in fruit fly and spider lineages. We review the putative selective pressures that may have led to the evolution of traumatic insemination across these lineages, as well as the pressures that continue to drive divergence in male and female reproductive morphology and behavior. Traumatic insemination mechanisms and attributes are compared across independent lineages.

  11. Radionuclide transfer in terrestrial animals

    International Nuclear Information System (INIS)

    DiGregorio, D.; Kitchings, T.; Van Voris, P.

    1978-01-01

    The analysis of dispersion of radionuclides in terrestrial food chains, generally, is a series of equations identifying the fractional input and outflow rates from trophic level to trophic level. Data that are prerequisite inputs for these food chain transport models include: (1) identification of specific transport pathway, (2) assimilation at each pathway link, and (3) the turnover rate or retention function by successive receptor species in the appropriate food chain. In this report, assimilation coefficients, biological half-lives, and excretion rates for a wide variety of vertebrate and invertebrate species and radionuclides have been compiled from an extensive search of the available literature. Using the information accumulated from the literature, correlations of nuclide metabolism and body weight are also discussed. (author)

  12. Terrestrial pathways of radionuclide particulates

    International Nuclear Information System (INIS)

    Boone, F.W.; Ng, Y.C.

    1981-01-01

    Formulations are developed for computing potential human intake of 13 radionuclides via the terrestrial food chains. The formulations are an extension of the NRC methodology. Specific regional crop and livestock transfer and fractional distribution data from the southern part of the U.S.A. are provided and used in the computation of comparative values with those computed by means of USNRC Regulatory Guide 1.109 formulations. In the development of the model, emphasis was also placed on identifying the various time-delay compartments of the food chains and accounting for all of the activity initially deposited. For all radionuclides considered, except 137 Cs, the new formulations predict lower potential intakes from the total of all food chains combined than do the comparable Regulatory Guide formulations by as much as a factor of 40. For 137 Cs the new formulations predict 10% higher potential intakes. (author)

  13. Phytopharmacological overview of Tribulus terrestris

    Science.gov (United States)

    Chhatre, Saurabh; Nesari, Tanuja; Somani, Gauresh; Kanchan, Divya; Sathaye, Sadhana

    2014-01-01

    Tribulus terrestris (family Zygophyllaceae), commonly known as Gokshur or Gokharu or puncture vine, has been used for a long time in both the Indian and Chinese systems of medicine for treatment of various kinds of diseases. Its various parts contain a variety of chemical constituents which are medicinally important, such as flavonoids, flavonol glycosides, steroidal saponins, and alkaloids. It has diuretic, aphrodisiac, antiurolithic, immunomodulatory, antidiabetic, absorption enhancing, hypolipidemic, cardiotonic, central nervous system, hepatoprotective, anti-inflammatory, analgesic, antispasmodic, anticancer, antibacterial, anthelmintic, larvicidal, and anticariogenic activities. For the last few decades or so, extensive research work has been done to prove its biological activities and the pharmacology of its extracts. The aim of this review is to create a database for further investigations of the discovered phytochemical and pharmacological properties of this plant to promote research. This will help in confirmation of its traditional use along with its value-added utility, eventually leading to higher revenues from the plant. PMID:24600195

  14. A Spherical Aerial Terrestrial Robot

    Science.gov (United States)

    Dudley, Christopher J.

    This thesis focuses on the design of a novel, ultra-lightweight spherical aerial terrestrial robot (ATR). The ATR has the ability to fly through the air or roll on the ground, for applications that include search and rescue, mapping, surveillance, environmental sensing, and entertainment. The design centers around a micro-quadcopter encased in a lightweight spherical exoskeleton that can rotate about the quadcopter. The spherical exoskeleton offers agile ground locomotion while maintaining characteristics of a basic aerial robot in flying mode. A model of the system dynamics for both modes of locomotion is presented and utilized in simulations to generate potential trajectories for aerial and terrestrial locomotion. Details of the quadcopter and exoskeleton design and fabrication are discussed, including the robot's turning characteristic over ground and the spring-steel exoskeleton with carbon fiber axle. The capabilities of the ATR are experimentally tested and are in good agreement with model-simulated performance. An energy analysis is presented to validate the overall efficiency of the robot in both modes of locomotion. Experimentally-supported estimates show that the ATR can roll along the ground for over 12 minutes and cover the distance of 1.7 km, or it can fly for 4.82 minutes and travel 469 m, on a single 350 mAh battery. Compared to a traditional flying-only robot, the ATR traveling over the same distance in rolling mode is 2.63-times more efficient, and in flying mode the system is only 39 percent less efficient. Experimental results also demonstrate the ATR's transition from rolling to flying mode.

  15. Hepatoprotective and Antioxidant Activities of Tribulus Terrestris

    NARCIS (Netherlands)

    Harraz, Fathalla M; Ghazy, Nabila M; Hammoda, Hala M; Nafeaa, Abeer A.; Abdallah, Ingy I.

    2015-01-01

    Tribulus terrestris L. has been used in folk medicine throughout history. The present study examined the acute toxicity of the total ethanolic extract of T. Terrestris followed by investigation of the hepatoprotective activity of the total ethanolic extract and different fractions of the aerial

  16. Design of a grounding network in electrical substations. Materials and formulas the most used; Diseno de redes de tierra en subestaciones electricas. Materiales y formulas mas utilizadas

    Energy Technology Data Exchange (ETDEWEB)

    Raull Martin, J. [Facultad de Ingenieria, UNAM, Mexico, D.F. (Mexico)

    2000-09-01

    The purpose of this paper is to present a summarized version of the different types of construction of grounding systems, as well as their materials and formulas, which are necessary and useful for the design and building of a grounding network for medium to high voltage facilities. A description is also made of how to determine the electrical resistivity of subsoil layers with different physical characteristics. Several illustrative examples are also solved in the paper. [Spanish] El proposito de este articulo es presentar de manera resumida los diferentes tipos de construccion de los sistemas de tierra, asi como sus materiales y formulas, los cuales son necesarios y utiles para el diseno y edificacion de una red de tierra para instalaciones de mediana y alta tension. Se describe tambien la obtencion de las diferentes resistividades que presenta los terrenos con diversas caracteristicas fisicas. Asimismo, se solucionan ejercicios ilustrativos a lo largo del articulo.

  17. Transient analysis for grounding systems considering the ground ionization; Analisis transitorio de sistemas de puesta a tierra considerando la ionizacion del suelo

    Energy Technology Data Exchange (ETDEWEB)

    Salgado Salgado, Luis Alberto

    2008-06-15

    All electrical installation must have an effective grounding system. The purpose of this grounding system is to provide a low impedance path for draining electric currents generated by faults, switching operations or atmospheric discharges to earth, avoiding damage to people, equipment or installations. High currents drained to ground leads to an electric field which can be capable of breaking down the dielectric strength of the ground. When this happens, the ionization phenomena takes place, which reduce the grounding system impedance and modify its performance. In this thesis, a computational model for evaluating the transient performance of grounding systems subjected to high magnitude and frequency currents is presented. The model is based in a transmission line approach and the grounding system transient analysis is carried out in the frequency domain. The time domain translation is performed by means of the Fast Fourier Inverse Transform (FFIT). The computer model is capable of simulating soil ionization. The computer model developed is used to study the performance of vertical rods and grounding grids of different sizes. In every case, different electric field magnitudes and soil's resistivity were used, currents of different frequency components and magnitude values where used as well. The obtained results presented were compared and validated with other computer model results and measurements published in the literature. [Spanish] Toda instalacion electrica debe contar con un sistema de puesta a tierra efectivo. La finalidad de este sistema es proporcionar un camino de baja impedancia para drenar a tierra las corrientes generadas por fallas, maniobras o fenomenos naturales como las descargas atmosfericas, evitando de esta manera danos a las personas, equipos o instalaciones. Cuando las corrientes drenadas a tierra son de gran magnitud se origina un campo electrico critico capaz de romper la rigidez dielectrica del suelo que rodea los conductores del

  18. The circumpolar biodiversity monitoring program - Terrestrial plan

    DEFF Research Database (Denmark)

    Christensen, Tom; Payne, J.; Doyle, M.

    The Circumpolar Biodiversity Monitoring Program, CBMP, Terrestrial Plan, www.caff.is/terrestrial, is a framework to focus and coordinate monitoring of terrestrial biodiversity across the Arctic. The goal of the plan is to improve the collective ability of Arctic traditional knowledge (TK) holders......, northern communities, and scientists to detect, understand and report on long-term change in Arctic terrestrial ecosystems and biodiversity. This presentation will outline the key management questions the plan aims to address and the proposed nested, multi-scaled approach linking targeted, research based...... monitoring with survey-based monitoring and remotely sensed data. The CBMP Terrestrial Plan intends to build upon and expand existing monitoring networks, engaging participants across a range of capacity and interests. The presentation will summarize the recommended focal soil ecosystem components...

  19. A la conquista de la tierra y del cielo: Rascacielos y poder tecno-económico A la conquista de la tierra y del cielo: Rascacielos y poder tecno-económico

    Directory of Open Access Journals (Sweden)

    Juan A. Roche Cárcel

    2008-04-01

    Full Text Available Along this work we have analyzed the way skyscrapers build a representation of the reality and of the economical world, how the will of power –particularly economic– is expressed and which is the nature of that power. And we conclude that the will of power reiterated by skyscrapers can be seen as uncontrollable, unsatisfied and insatiable of life and deeply irrational, so we can say that the Schopenhauer, Nietzsche and Freud programs have been completed as far as for them, power means the absolute and unlimited, irrational and blind will to live. But, at the same time, skyscrapers compliment the weberian program because they search for legitimacy and exemplify a certain visible configuration of power, individual and collective, personal and impersonal. In a few words, although skyscrapers from an horizontal point of view look close to the city and earth, vertically seem move away form earth which denotes, finally that they pretend not only triumph over earth but over the sky.Este artículo analiza qué determinada representación de la realidad y del mundo económico construyen los rascacielos, cómo expresan la voluntad de poder, especialmente la económica, y de qué tipo es. Y concluye que la voluntad de poder que reiteran es irrefrenable, insatisfecha e insaciable de vida y profundamente irracional, con lo que se cumple en ellos el programa de Shopenhauer, de Nietzsche y de Freud, según el cual el poder es voluntad de vivir absoluta e ilimitada, irracional y ciega. Y, al mismo tiempo, los rascacielos cumplimentan el programa weberiano porque buscan la legitimidad y ejemplifican una estructuración del poder visible e individual, colectivo y personal e impersonal. En definitiva, aunque el rascacielos en su plano horizontal se acerca a la ciudad y a la tierra, en el vertical parece alejarse cada vez más de ella, lo que denota, en último extremo, que no sólo pretende conquistar la tierra sino también el cielo.

  20. Efecto del cierre de las escuelas sobre el brote de influenza A H1N1 en Tierra del Fuego, Argentina Impact of school closings on the influenza A (H1N1 outbreak in Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Pablo Wenceslao Orellano

    2010-03-01

    Full Text Available Se evaluó el efecto del cierre de las escuelas en la reducción del número de casos de enfermedades del tipo influenza durante un brote de influenza A por el virus H1N1, de características pandémicas, en las dos principales ciudades de la provincia de Tierra del Fuego, en la región austral de Argentina, en conjunto con otras medidas de control. Se comparó la incidencia antes y después del cierre de las escuelas en 2009 mediante la prueba de la t para muestras relacionadas. Hasta la semana 40 se detectaron 6 901 casos de enfermedades del tipo influenza, de ellos 281 se confirmaron como influenza A H1N1 mediante pruebas de laboratorio; 38 pacientes recibieron hospitalización. Se observó una reducción de cerca de 10 veces en la incidencia promedio registrada en los centros de salud después de la intervención. Los resultados indican que el cierre de las escuelas durante el brote de influenza A H1N1 se acompañó de una reducción significativa de la incidencia de enfermedades tipo influenza, aunque no se debe descartar el efecto de otras acciones, como el tratamiento de los casos y la profilaxis de sus contactos. Esta intervención, aplicada oportunamente, junto con otras medidas, puede contribuir a reducir la propagación de los brotes de influenza."The impact of school closings on reducing the number of cases of influenza-like illness during an outbreak of influenza A (H1N1, which reached pandemic proportions, was assessed, along with other control measures, in the two main cities of Tierra del Fuego Province in southern Argentina. The incidence before and after the school closings in 2009 was compared by means of the t-test for related samples. By week 40, 6 901 cases of influenza-like illness had been detected, 281 of which were confirmed as influenza A (H1N1 through laboratory tests; 38 patients were hospitalized. After the intervention, there were nearly 10 times fewer cases than the average recorded in the health centers. The

  1. Determinación de las características de la tierra utilizando el método de inclinación de la onda

    OpenAIRE

    Cevallos Villacreses, Mario; Sánchez Almeida, Tarquino

    2007-01-01

    Se describe un método alternativo para la determinación de las características eléctricas de la tierra, empleando el método de la INCLINACIÓN DE LA ONDA, el mismo que a diferencia de otros métodos, permite la medición directa de la permitividad y conductividad. Para este efecto se desarrolló un equipamiento especial cuyas características y funciones se detallan.

  2. El acaparamiento de tierras en América Latina y el Caribe visto desde una perspectiva internacional más amplia

    NARCIS (Netherlands)

    S.M. Borras jr. (Saturnino); J.C. Franco (Jennifer); C. Kay (Cristóbal); M. Spoor (Monique)

    2012-01-01

    markdownabstractEste volumen continúa la discusión surgida de los antecedentes recogidos en la investigación presentada en el libro “Dinámicas del mercado de la tierra en América Latina y el Caribe: concentración y extranjerización”, publicado por la Oficina Regional de la FAO en junio de

  3. Producción de biomasa aérea y uso equivalente de la tierra en intercultivos de alfalfa (Medicago sativa L.

    Directory of Open Access Journals (Sweden)

    T. W Pereyra

    Full Text Available Tradicionalmente, el incremento de la productividad se ha asociado al aumento del rendimiento a través del mejoramiento genético y las prácticas de manejo del cultivo. Sin embargo, si se considera la producción por unidad de área y de tiempo, el sistema de intercultivos puede ser otra forma de mejorar la rentabilidad. El objetivo del experimento fue determinar la biomasa producida y el uso equivalente de la tierra en monocultivo e intercultivos de alfalfa (Medicago sativa L. con sorgo sudán (Sorghum sudanense L. y avena (Avena sativa L.. Se determinó la biomasa aérea de todos los tratamientos (expresada por unidad de superficie y el uso equivalente de la tierra. El diseño fue completamente aleatorizado, dispuesto en bloques con dos repeticiones. Los resultados se sometieron a un ANOVA y las medias se compararon mediante la prueba de Duncan, a través del paquete estadístico INFOSTAT. El intercultivo alfalfa-sorgo triplicó la producción de alfalfa en relación con el monocultivo, mientras que alfalfa-avena no superó la producción de alfalfa pura en los meses de invierno. El intercultivo alfalfa-sorgo fue un 57 % más eficiente en el uso de la tierra que sus respectivos monocultivos, mientras que alfalfa-avena no logró superar la unidad.

  4. A new form of land concentration in Colombia Una nueva forma de concentración de la tierra en Colombia:la ley 1448 de 2011

    Directory of Open Access Journals (Sweden)

    Juan Pablo Henao Guzmán

    2012-06-01

    Full Text Available This article aims to show how the Law 1448 of 2011, which explains reparation and restitution of victims, and the National Development Plan (NDP 2011-2014 generate land concentration in Colombia. This is due to how the NDP objectives disintegrate the Law 1448 objectives; this phenomenon could be explained using an agency model and the subsequent moral risk issue formed between the State and the victims. Regarding these results, a game-theory model was built, and this effectively concludes that the Law 1448 and the NDP generate land concentration in ColombiaEn este artículo se pretende mostrar, mediante un análisis económico, cómo la Ley 1448 de 2011 (o Ley de Víctimas y Restitución de Tierras, junto al Plan Nacional de Desarrollo (PND 2011-2014, generan concentración de la tierra en Colombia. Esto se debe a que los objetivos del PND terminan disgregando los que busca la Ley 1448, lo cual se explica con el uso de un modelo de agencia y el subsecuente problema de riesgo moral para el Estado y las víctimas del conflicto. A partir de los resultados anteriores se construye un modelo de teoría de juegos, del que se concluye que, efectivamente, la Ley 1448 y el PND generan concentración de la tierra en Colombia.

  5. Cruzada, herejía e inquisición en las tierras de la Corona de Aragón (siglos XII-XIII

    Directory of Open Access Journals (Sweden)

    Smith, Damian

    2013-06-01

    Full Text Available This study explores three interconnected subjects concerning the general theme of heterodoxy in the Thirteenth Century: the Albigensian Crusade; the increase of heresy in the lands of the Crown of Aragón, and the development of the Inquisition. Firstly, we ask if the decisions taken by James I were the necessary consequence of the defeat of the battle of Muret in order to avoid a direct conflict with the papacy and France. Second, we examine where heresy as present and absent in the lands of the Crown. Third, we suggest reasons why the inquisition took a distinctive form in the lands of the Crown.Este estudio explora tres asuntos conectados con el tema general de la heterodoxia en el siglo XIII: la Cruzada contra los Albigenses, el aumento de la herejía en las tierras de la Corona de Aragón y el desarrollo de la Inquisición. Nos preguntamos, primero, si las decisiones tomadas por Jaime I fueron la consecuencia necesaria de la derrota en la batalla de Muret para evitar un conflicto directo con el Papado y Francia. Segundo, examinamos dónde estuvo presente y dónde ausente la herejía en las tierras de la Corona de Aragón. Tercero, sugerimos las razones por las qué la Inquisición adoptó una forma distintiva en las tierras catalano-aragonesas.

  6. Los ocupantes de tierras en la Norpatagonia. Los Inspectores nacionales, el colono ideal y el poblador real al comenzar el siglo XX

    Directory of Open Access Journals (Sweden)

    Blanco, Graciela

    2016-12-01

    Full Text Available El presente trabajo realiza una aproximación a los pobladores que se asentaron en el norte de la Patagonia Argentina, particularmente en el Territorio de Río Negro, a partir de los informes de inspección realizados por funcionarios de la Dirección Nacional de Tierras en los años 1904, 1910 y 1920-21. Estos informes no abarcan la totalidad del territorio, inspeccionándose en esos años distintas zonas, particularmente las destinadas a funcionar como colonias o reservas –Conesa, Choele Choel, Frias, El Cuy, Valcheta-. Los mismos dan cuenta de los pobladores, la forma de tenencia de la tierra, la producción y las inversiones realizadas, clasificando y calificando a los pobladores de acuerdo a diferentes variables. El relato construido por estos inspectores resultaba el insumo más importante a la hora de decidir el acceso a la tierra. Se estudian los informes que estos agentes estatales producían, caracterizando las condiciones del poblamiento y puesta en producción de la región por parte de los pequeños productores de ganado menor o crianceros, complementando esas fuentes con la prensa regional y la producción existente sobre el tema.

  7. “Más ganados que frutos”. La evolución de la tenencia de la tierra en Hatoviejo (Bello, Antioquia, siglos XVII a XVIII

    Directory of Open Access Journals (Sweden)

    Rodrigo de Jesús García Estrada

    2011-07-01

    Full Text Available Este artículo es una aproximación histórica a la evolución en la tenencia de la tierra en Hatoviejo (Bello, Antioquia, Colombia durante los siglos XVII y XVIII. En él se estudia el proceso de fragmentación de la merced de tierras entregada por el cabildo de la ciudad de Antioquia al conquistador Gaspar de Rodas en el siglo XVI, quien lo cedió a sus hijos. Brevemente se muestra como aquellas inmensas propiedades se subdividieron hasta conformar varios hatos y estancias donde se producían muchos de los alimentos que se consumían en la provincia. A partir de los protocolos notariales se reconstruye el proceso subsiguiente de fragmentación de aquellas haciendas hasta la aparición de pequeñas y medianas propiedades en manos de mestizos, indígenas y pardos libres, para concluir con el análisis de la estructura tenencial de la tierra al final del periodo estudiado.

  8. Persuasión lingüística para la defensa de la tierra: El Título Primordial de Santiago Sula

    Directory of Open Access Journals (Sweden)

    Marta Puente González

    2016-07-01

    Full Text Available Los pueblos de indios de la Nueva España crearon, a fines de la época colonial, una forma de  defender sus territorios ante la amenaza de colonos españoles, criollos y otros indios que usurpaban ilegalmente terrenos e intentaban rentabilizar el control de las tierras. Empezaron a producir un tipo de textos, sus Títulos Primordiales, que presentaban en los juicios para demostrar la titularidad de sus posesiones. No son textos del tipo administrativo, sino que insertan narraciones con los acontecimientos pasados más importantes para la comunidad. Pero principalmente son escritos que fueron pensados para persuadir a los receptores de la veracidad de sus argumentos. Buscaban convencer, en lo lingüístico y textual, para tener efecto en la vida real: que no se les arrebatase sus tierras. En este trabajo se abordará la aproximación a este tipo textual mediante el estudio, desde la pragmática lingüística y el análisis del discurso, del Título Primordial de Santiago Sula, un documento paradigmático del género. Con ello se quiere demostrar que el Título Primordial de Santiago Sulase caracteriza por una estructura argumentativa con un narrador que dispone de distintos tipos de argumentos y otras estrategias textuales para reforzar la única conclusión final: la defensa dela tierra.

  9. La tierra pública periurbana: Arrendamiento, enfiteusis y ventas en el entorno agrario de Buenos Aires [San José de Flores, 1800-1862

    Directory of Open Access Journals (Sweden)

    María Valeria Ciliberto

    2009-04-01

    Full Text Available Las distintas cuestiones vinculadas al traspaso de las tierras públicas a manos particulares [en usufructo y en propiedad plena] en la campaña bonaerense del siglo XIX han suscitado el interés de diversos investigadores que, a partir de estudios de casos mayoritariamente vinculados a la dinámica de expansión de la frontera sur, delinearon las modalidades generales del proceso. Abordando el estudio de los distintos modos de acceso a la tenencia y propiedad de la tierra, en el contexto de la venta de los terrenos fiscales situados en el entorno agrario de la ciudad de Buenos Aires, pretendemos sumar al conocimiento de esta dinámica las particularidades de un área de muy antiguo asentamiento y ocupación productiva, con una larga tradición de arrendamiento de tierras de 'pan llevar' de antigua propiedad eclesiástica y una agricultura mercantil de pequeños y medianos productores orientada al abasto urbano

  10. «Le Domaine de la Terre», un conjunto de realizaciones-piloto a base de tierra, en L'isle D'abeau (Francia

    Directory of Open Access Journals (Sweden)

    Salas, J.

    1986-02-01

    Full Text Available In this work, some of the experimental housing works (blocks, formwork, mud and straw... built on the outskirts of Lyon (France are presented in a systematic way. The ensemble is called «Le Domaine de la Terre», and eleven different projects are concerned, where a number of institutions and teams of professionals have worked. In its whole it is an excelent exposition at natural scale of the possibilities of mud construction, even though the results are of a great diversity -formal and conceptually- between those diverse projects.Se presentan en el trabajo de forma sistematizada algunas de las realizaciones de viviendas experimentales a base de tierra (bloques, tapial, bloques compactados, tierra-paja.... realizadas en las cercanías de Lyon (Francia y que constituyen el conjunto «Le Domaine de la Terre». Se trata de una realización a base de once proyectos distintos en los que han intervenido un buen número de instituciones, equipos de proyecto y profesionales franceses. Globalmente constituyen una excelente exposición a escala natural de las posibilidades de las construcciones de tierra, aunque los resultados son muy diversos -formal y conceptualmente- entre los distintos proyectos.

  11. De la tierra al suelo: la transformación del paisaje y el nuevo turismo residencial

    Directory of Open Access Journals (Sweden)

    Aledo Tur, Antonio

    2008-02-01

    Full Text Available Residential Tourism has had a main role of speeding up the social and environmental processes of change that took place in Spain during the second half of the last century. This article begins with the description of its main characteristics, its effects at a local level and the different phases of its evolution. A special reference will be made with regard to last phase (2002-2007 which has been nomitaded New Residential Tourism (NRT. NRT is characterized by the appearance of urban megaprojects of thousands of households, with several golf courses and all the services needed. Its goal is to build privatized units of residential leisure, which are autonomous and independent from the territory where they are settled. In this paper there is an underlying reflection about the socio-cultural consequences of the transformation of agricultural land into urban land. A land that is definitely denatured and transformed into urban space for tourism consumption.El turismo residencial ha sido un agente acelerador de los procesos de transformación social y ambiental acaecidos en la España mediterránea durante la segunda mitad del siglo pasado. Este trabajo se inicia con la descripción de sus principales características, sus efectos a escala local y sus diferentes fases evolutivas. Se hará una especial referencia al último período que se ha iniciado en 2002 y que se ha denominado Nuevo Turismo Residencia (NTR. El NTR se caracteriza por la aparición de megaproyectos urbanísticos de miles de viviendas, con varios campos de golf y todos los servicios necesarios para convertirlo en una unidad de ocio residencial privatizada, autónoma e independiente del territorio en el que se instale. En última instancia, en este artículo subyace una reflexión en torno a las consecuencias socioculturales de la transformación de la tierra en suelo ya que éste es el principal recurso del turismo residencial. La tierra ha pasado de entenderse como un espacio para la

  12. HACIA UNA POÉTICA DE SOLEDAD FARIÑA: PROTOTEXTO Y ESCRITURA CIFRADA EN LA VOCAL DE LA TIERRA

    Directory of Open Access Journals (Sweden)

    Javier Bello

    2009-11-01

    Full Text Available Este trabajo pretende atender al carácter mitogenésico de la narración "Al alba", perteneciente al libro Otro cuento de pájaros (Santiago: Las Dos Fridas, 1999 de Soledad Fariña, como prototexto y paralelo de la "escritura" del Libro que fragmentariamente -desde el cuestiona-miento constante de los medios de representación y la capacidad perceptiva del poema- se realizará en la trilogía La vocal de la tierra (Santiago: Cuarto Propio, 1999, que incluye los poemarios El Primer Libro (Santiago: Amaranto, 1985, Albricia (Santiago: Archivo, 1988 y En Amarillo Oscuro (Santiago: Surada, 1994, constituyéndose como una nueva escritura sagrada -alternativa al libro judeocristiano patriarcal- de identificación prehispánica, de epicentro genérico femenino, que constituye a la sujeto en relación protolésbica con la Madre, ofrendante con respecto a la Diosa iniciadora, e integrante de la pareja de Amazonas amantes.This paper examines the mythogenesic character ofthe story "Al alba " from the book Otro cuento de pájaros (Santiago: Las Dos Fridas, 1999 by Soledad Fariña, seen as aprototext and a paralel to the "writing " ofthe Book that in afragmentary way -under the constant questioning ofthe means of representation and the perceptive capacity to be found in this poem- is realizedin the trilogy entitled La vocal de la tierra (Santiago: Cuarto Propio, 1999, a book that includes the collections ofpoems El Primer Libro (Santiago: Amaranto, 1985, Albricia (Santiago: Archivo, 1988 and En amarillo oscuro (Santiago: Surada, 1994; the trilogy thus becomes a new Holy Scripture -an alternative to the judeo-christian and patriar-chal Book- which can be identifiedwith the prehispanic culture and is focused in the female gender that constitutes the subject in a protolesbic relation with the Mother, as an offering to the iniciating Goddess, and as a member ofthe couple ofAmazon lovers.

  13. EN LA RESIDENCIA EN LA TIERRA, UN “CABALLERO SOLO” VIVE POSEÍDO POR EL DESEO

    Directory of Open Access Journals (Sweden)

    Luis Alfonso Castro Sotelo

    2011-09-01

    Full Text Available A través del análisis textual, palabras clave, estructura, tema y perspectiva de la voz lírica, se pretende rescatar los elementos estéticos e ideológicos del poema "Caballero solo" del libro Residencia en la tierra. Se asume tal poema como evidencia de la transformación en el sistema nerudiano, un poema donde los elementos de lo social conviven y se enfrentan contra el sujeto individual que escribe y padece. En cierto modo, este poema propone una explicación tipo tesis sobre el funcionamiento del deseo, origen y tránsito, y la vida sexual del mundo social que rodea al poeta y que provoca el retorno posible al espacio primigenio del bosque, la naturaleza y los monstruos de la fantasía: después de percibir el sexo en todas partes, el poeta se protege y rodea por los elementos que lo acompañaron en la infancia y, tal vez, formaron parte del paisaje de todos los hombres a la hora del deseo y del sexo.In these pages, the poem "Caballero solo" is seen as a particularly rich discourse for textual analysis. The poem is built up around key words and concepts, an evocative structure, an attractive issue, and a thought provoking perspective, following an undoubtedly Nerudian lyric voice. The focus lies on the aesthetic and ideological elements in "Caballero solo", included in Residencia en la tierra. The poem is seen as evidence of a transformation in the Nerudian system, where the social elements coexist along with and confront the subject who writes and suffers. Emphasis is paid to the way the poem states a thesis regarding the functioning of desires, their origins and evolution, and sexuality in the social world of the poet, the subject. This world provides a possibility of returning to the primitive spaces of nature, the woods, and the monsters of fantasy. After having perceived sexuality everywhere, the poet shelters himself amongst the elements of his infancy, which can be taken as a common human landscape alluding to sex and desire.

  14. A molecular palaeobiological exploration of arthropod terrestrialization

    Science.gov (United States)

    Carton, Robert; Edgecombe, Gregory D.

    2016-01-01

    Understanding animal terrestrialization, the process through which animals colonized the land, is crucial to clarify extant biodiversity and biological adaptation. Arthropoda (insects, spiders, centipedes and their allies) represent the largest majority of terrestrial biodiversity. Here we implemented a molecular palaeobiological approach, merging molecular and fossil evidence, to elucidate the deepest history of the terrestrial arthropods. We focused on the three independent, Palaeozoic arthropod terrestrialization events (those of Myriapoda, Hexapoda and Arachnida) and showed that a marine route to the colonization of land is the most likely scenario. Molecular clock analyses confirmed an origin for the three terrestrial lineages bracketed between the Cambrian and the Silurian. While molecular divergence times for Arachnida are consistent with the fossil record, Myriapoda are inferred to have colonized land earlier, substantially predating trace or body fossil evidence. An estimated origin of myriapods by the Early Cambrian precedes the appearance of embryophytes and perhaps even terrestrial fungi, raising the possibility that terrestrialization had independent origins in crown-group myriapod lineages, consistent with morphological arguments for convergence in tracheal systems. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’. PMID:27325830

  15. Steroidal saponins from Tribulus terrestris.

    Science.gov (United States)

    Kang, Li-Ping; Wu, Ke-Lei; Yu, He-Shui; Pang, Xu; Liu, Jie; Han, Li-Feng; Zhang, Jie; Zhao, Yang; Xiong, Cheng-Qi; Song, Xin-Bo; Liu, Chao; Cong, Yu-Wen; Ma, Bai-Ping

    2014-11-01

    Sixteen steroidal saponins, including seven previously unreported compounds, were isolated from Tribulus terrestris. The structures of the saponins were established using 1D and 2D NMR spectroscopy, mass spectrometry, and chemical methods. They were identified as: 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-2α,3β,22α,26-tetrol-12-one (terrestrinin C), 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-22α,26-diol-3,12-dione (terrestrinin D), 26-O-β-d-glucopyranosyl-(25S)-furost-4-en-22α,26-diol-3,6,12-trione (terrestrinin E), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-3β,22α,26-triol-12-one (terrestrinin F), 26-O-β-d-glucopyranosyl-(25R)-furost-4-en-12β,22α,26-triol-3-one (terrestrinin G), 26-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranosyl-(25R)-furost-4-en-22α,26-diol-3,12-dione (terrestrinin H), and 24-O-β-d-glucopyranosyl-(25S)-5α-spirostan-3β,24β-diol-12-one-3-O-β-d-glucopyranosyl-(1→4)-β-d-galactopyranoside (terrestrinin I). The isolated compounds were evaluated for their platelet aggregation activities. Three of the known saponins exhibited strong effects on the induction of platelet aggregation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. The Circumpolar Biodiversity Monitoring Program Terrestrial Plan

    DEFF Research Database (Denmark)

    Christensen, Tom; Payne, J.; Doyle, M.

    and coastal environments. The CBMP Terrestrial Plan is a framework to focus and coordinate monitoring of terrestrial biodiversity across the Arctic. The goal of the plan is to improve the collective ability of Arctic traditional knowledge (TK) holders, northern communities, and scientists to detect......The Conservation of Arctic Flora and Fauna (CAFF), the biodiversity working group of the Arctic Council, established the Circumpolar Biodiversity Monitoring Program (CBMP) to address the need for coordinated and standardized monitoring of Arctic environments in terrestrial, marine, freshwater...

  17. «En tierra de hombres» (2005. El acoso psicológico en el trabajo

    Directory of Open Access Journals (Sweden)

    Carmen María VIZOSO GÓMEZ

    2016-10-01

    Full Text Available El acoso psicológico en el trabajo está considerado un grave problema en el entorno laboral debido a los efectos negativos que provoca no solo en la convivencia dentro de la empresa y en la productividad de los trabajadores sino también en la salud de la víctima y en el bienestar de su familia. La película En tierra de hombres está inspirada en un caso real de acoso en el trabajo, concretamente de acoso sexual, sufrido por las mujeres que trabajaban en una mina de hierro. Esta situación desembocó en la primera demanda colectiva sobre discriminación sexual. En el presente artículo se analizan las escenas, los diálogos y las características de los personajes para explicar en qué consiste este tipo de acoso. Así, se describe el clima laboral en la empresa, las conductas vejatorias de los acosadores, el proceso de desarrollo del problema hasta que la víctima abandona la empresa, las consecuencias del acoso en diversos ámbitos y también una posible forma de solucionarlo. Por último, se defiende el valor que tiene este film como recurso didáctico para la formación de estudiantes y trabajadores y para la prevención del acoso en el ámbito laboral.

  18. La restitución de la tierra y la prevención del desplazamiento forzado en Colombia

    Directory of Open Access Journals (Sweden)

    Felipe Gómez-Isa

    2010-12-01

    Full Text Available El conflicto armado interno en Colombia se caracteriza por la generación de más de tres millones de desplazados internos, con consecuencias dramáticas desde el punto de vista humanitario y desde la óptica de la protección de sus derechos. En ocasiones, las razones fundamentales de dicho desplazamiento descansan en una dinámica de control y apropiación territorial con fines tanto estratégico-militares como puramente económicos. Los estándares jurídicos de orden interno e internacional establecen el derecho de las víctimas a la restitución de sus viviendas y patrimonio como el “medio preferente” de reparación en casos de desplazamiento, algo que no se está teniendo en cuenta suficientemente por parte de las políticas de atención al desplazamiento del Gobierno colombiano y de diversas instituciones internacionales. Cualquier política integral de reparación a las víctimas debe pasar necesariamente por la reversión del despojo de tierras, territorios y bienes que se ha producido en Colombia al amparo del conflicto armado interno.

  19. El arbitrio de tierras de 1622 y el debate sobre las propiedades y los derechos coloniales de los indios

    Directory of Open Access Journals (Sweden)

    Glave, Luis Miguel

    2014-06-01

    Full Text Available This article analyses the 1622 tax on the sale of lands within the context of the broad debate regarding the lawfulness of the sale and composition of properties, initiated at the end of the sixteenth century. The opportunity to press upon the natives’ resources is studied, as well as the defensive measures available to them, while striving to call attention to the dialogue between metropolitan policy – which sought to increase monetary resources in times of need – and discrepancies within the Andean kingdom at a time of legal and administrative changes that attempted to respond to imperial demands.Este artículo analiza un arbitrio sobre la venta de tierras de 1622, situándolo en el extenso debate acerca de la licitud de la enajenación y composición de propiedades comenzado a finales del siglo XVI. Se estudia la coyuntura de presión sobre los recursos de los naturales y las opciones de defensa de los mismos, procurando resaltar el diálogo entre la política metropolitana, que buscaba ampliar recursos monetarios en tiempo de necesidad, y las discrepancias internas del reino andino en pleno proceso de cambios administrativos y legales que intentaban responder a esa demanda imperial.

  20. Martín Sancho (siglos XIV-XVI un despoblado bajomedieval en la tierra de Medellín

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    Julián Clemente Ramos

    2006-08-01

    Full Text Available The Extremaduran village of Martin Sancho is documented for the first time in 1374. In the second half of the fourteenth century, something that may initially have been an individual appropriation has given rise to a concentrated settlement. Its population seems never to have been more than twenty-five. This village had its own district and council, whose only official was the mayor. Its inhabitants were parishioners of the church of San Martin de Medellín. Around the middle of the fifteenth century, Martin Sancho experienced a certain demographic decline, its population no more than 15-20, of whom only a part resided there permanently. This situation appears to have increased the importance of cattle raising, in the context of the relative abundance of grasses and perhaps also the accumulation of properties on the part of qualified members of the village. The violence of the governor of the tierra and future landlord Rodrigo Portocarrero, who appropriates the district, produces rapid depopulation. In the first quarter of the sixteenth century, Medellín manages through a judicial process to integrate it in its public land.

  1. Terrestrial teleconnections link global rivers

    Science.gov (United States)

    O'Loughlin, F.; Howden, N. J.; Woods, R. A.; Bates, P. D.

    2013-12-01

    . Aside from these practical applications, the results also suggest teleconnections exist between terrestrial, as well as ocean and atmospheric water systems.

  2. Durable terrestrial bedrock predicts submarine canyon formation

    Science.gov (United States)

    Smith, Elliot; Finnegan, Noah J.; Mueller, Erich R.; Best, Rebecca J.

    2017-01-01

    Though submarine canyons are first-order topographic features of Earth, the processes responsible for their occurrence remain poorly understood. Potentially analogous studies of terrestrial rivers show that the flux and caliber of transported bedload are significant controls on bedrock incision. Here we hypothesize that coarse sediment load could exert a similar role in the formation of submarine canyons. We conducted a comprehensive empirical analysis of canyon occurrence along the West Coast of the contiguous United States which indicates that submarine canyon occurrence is best predicted by the occurrence of durable crystalline bedrock in adjacent terrestrial catchments. Canyon occurrence is also predicted by the flux of bed sediment to shore from terrestrial streams. Surprisingly, no significant correlation was observed between canyon occurrence and the slope or width of the continental shelf. These findings suggest that canyon incision is promoted by greater yields of durable terrestrial clasts to the shore.

  3. Durable Terrestrial Bedrock Predicts Submarine Canyon Formation

    Science.gov (United States)

    Smith, M. Elliot; Finnegan, Noah J.; Mueller, Erich R.; Best, Rebecca J.

    2017-10-01

    Though submarine canyons are first-order topographic features of Earth, the processes responsible for their occurrence remain poorly understood. Potentially analogous studies of terrestrial rivers show that the flux and caliber of transported bedload are significant controls on bedrock incision. Here we hypothesize that coarse sediment load could exert a similar role in the formation of submarine canyons. We conducted a comprehensive empirical analysis of canyon occurrence along the West Coast of the contiguous United States which indicates that submarine canyon occurrence is best predicted by the occurrence of durable crystalline bedrock in adjacent terrestrial catchments. Canyon occurrence is also predicted by the flux of bed sediment to shore from terrestrial streams. Surprisingly, no significant correlation was observed between canyon occurrence and the slope or width of the continental shelf. These findings suggest that canyon incision is promoted by greater yields of durable terrestrial clasts to the shore.

  4. Parallel Computing for Terrestrial Ecosystem Carbon Modeling

    International Nuclear Information System (INIS)

    Wang, Dali; Post, Wilfred M.; Ricciuto, Daniel M.; Berry, Michael

    2011-01-01

    Terrestrial ecosystems are a primary component of research on global environmental change. Observational and modeling research on terrestrial ecosystems at the global scale, however, has lagged behind their counterparts for oceanic and atmospheric systems, largely because the unique challenges associated with the tremendous diversity and complexity of terrestrial ecosystems. There are 8 major types of terrestrial ecosystem: tropical rain forest, savannas, deserts, temperate grassland, deciduous forest, coniferous forest, tundra, and chaparral. The carbon cycle is an important mechanism in the coupling of terrestrial ecosystems with climate through biological fluxes of CO 2 . The influence of terrestrial ecosystems on atmospheric CO 2 can be modeled via several means at different timescales. Important processes include plant dynamics, change in land use, as well as ecosystem biogeography. Over the past several decades, many terrestrial ecosystem models (see the 'Model developments' section) have been developed to understand the interactions between terrestrial carbon storage and CO 2 concentration in the atmosphere, as well as the consequences of these interactions. Early TECMs generally adapted simple box-flow exchange models, in which photosynthetic CO 2 uptake and respiratory CO 2 release are simulated in an empirical manner with a small number of vegetation and soil carbon pools. Demands on kinds and amount of information required from global TECMs have grown. Recently, along with the rapid development of parallel computing, spatially explicit TECMs with detailed process based representations of carbon dynamics become attractive, because those models can readily incorporate a variety of additional ecosystem processes (such as dispersal, establishment, growth, mortality etc.) and environmental factors (such as landscape position, pest populations, disturbances, resource manipulations, etc.), and provide information to frame policy options for climate change

  5. Anthropogenic transformation of the terrestrial biosphere.

    Science.gov (United States)

    Ellis, Erle C

    2011-03-13

    Human populations and their use of land have transformed most of the terrestrial biosphere into anthropogenic biomes (anthromes), causing a variety of novel ecological patterns and processes to emerge. To assess whether human populations and their use of land have directly altered the terrestrial biosphere sufficiently to indicate that the Earth system has entered a new geological epoch, spatially explicit global estimates of human populations and their use of land were analysed across the Holocene for their potential to induce irreversible novel transformation of the terrestrial biosphere. Human alteration of the terrestrial biosphere has been significant for more than 8000 years. However, only in the past century has the majority of the terrestrial biosphere been transformed into intensively used anthromes with predominantly novel anthropogenic ecological processes. At present, even were human populations to decline substantially or use of land become far more efficient, the current global extent, duration, type and intensity of human transformation of ecosystems have already irreversibly altered the terrestrial biosphere at levels sufficient to leave an unambiguous geological record differing substantially from that of the Holocene or any prior epoch. It remains to be seen whether the anthropogenic biosphere will be sustained and continue to evolve.

  6. Linking animals aloft with the terrestrial landscape

    Science.gov (United States)

    Buler, Jeffrey J.; Barrow, Wylie; Boone, Matthew; Dawson, Deanna K.; Diehl, Robert H.; Moore, Frank R.; Randall, Lori A.; Schreckengost, Timothy; Smolinsky, Jaclyn A.

    2018-01-01

    Despite using the aerosphere for many facets of their life, most flying animals (i.e., birds, bats, some insects) are still bound to terrestrial habitats for resting, feeding, and reproduction. Comprehensive broad-scale observations by weather surveillance radars of animals as they leave terrestrial habitats for migration or feeding flights can be used to map their terrestrial distributions either as point locations (e.g., communal roosts) or as continuous surface layers (e.g., animal densities in habitats across a landscape). We discuss some of the technical challenges to reducing measurement biases related to how radars sample the aerosphere and the flight behavior of animals. We highlight a recently developed methodological approach that precisely and quantitatively links the horizontal spatial structure of birds aloft to their terrestrial distributions and provides novel insights into avian ecology and conservation across broad landscapes. Specifically, we present case studies that (1) elucidate how migrating birds contend with crossing ecological barriers and extreme weather events, (2) identify important stopover areas and habitat use patterns of birds along their migration routes, and (3) assess waterfowl response to wetland habitat management and restoration. These studies aid our understanding of how anthropogenic modification of the terrestrial landscape (e.g., urbanization, habitat management), natural geographic features, and weather (e.g., hurricanes) can affect the terrestrial distributions of flying animals.

  7. Caracterización de suelos bajo bosques de Nothofagus betuloides (Mirb Blume, en Tierra del Fuego, Chile Characterization of soils of Nothofagus betuloides (Mirb Blume forests, in Tierra del Fuego, Chile

    Directory of Open Access Journals (Sweden)

    VÍCTOR GERDING

    2002-12-01

    Full Text Available En tres sectores de la parte occidental de Tierra del Fuego (54º45'-54º15' S, 68º40'-70º10' O se caracterizó morfológica, física y químicamente los suelos bajo bosques de coigüe de Magallanes (Nothofagus betuloides (Mirb Blume y sus especies asociadas lenga (Nothofagus pumilio (P. et E. Krasser y canelo (Drimys winteri Forst.. Se describieron 85 perfiles de suelo y aproximadamente 250 observaciones con bastón pedológico. Los suelos bajo coigüe de Magallanes eran jóvenes, muy influidos por la actividad volcánica, topografía y clima. Se observó la presencia de los órdenes Spodosol e Iceptisol, principalmente. En general los suelos eran delgados a muy delgados (mayoritariamente entre 10 y 40 cm, con un alto volumen de esqueleto, textura franca, estructura masiva a granular, capacidad de agua aprovechable baja y drenaje externo e interno moderado a lento. Además, presentan una alta acidez (pH 4-5,5, una baja oferta nutricional y muy altos niveles de saturación de aluminio (promedio > 60 %. El mantillo (Oe/Oa presentó condiciones adecuadas para el desarrollo radicular. Existe comúnmente un horizonte blanco (frecuentemente 10 YR 5/1-2 inmediatamente debajo del mantillo, con textura franco limosa y estructura masiva, con arraigamiento muy bajo. Se plantea como hipótesis que este horizonte se originó por depósitos de cenizas volcánicas y procesos de podzolización. Se concluye que la fertilidad de estos suelos es baja debido a limitantes físicas (dificultades de arraigamiento y químicas (acidez, toxicidad de aluminio, baja oferta de basesSoils under coigüe de Magallanes (Nothofagus betuloides (Mirb Blume forests, located in the oriental part of Tierra del Fuego (54º45'-54º15' S, 68º40'-70º10' W, were characterized morphologically, physically and chemically. Associated tree species were lenga (Nothofagus pumilio (P. et E. Krasser and canelo (Drimys winterii Forst.. A total of 85 soil profiles and approximately 250 soil

  8. Groundwater and Terrestrial Water Storage

    Science.gov (United States)

    Rodell, Matthew; Chambers, Don P.; Famiglietti, James S.

    2011-01-01

    Most people think of groundwater as a resource, but it is also a useful indicator of climate variability and human impacts on the environment. Groundwater storage varies slowly relative to other non-frozen components of the water cycle, encapsulating long period variations and trends in surface meteorology. On seasonal to interannual timescales, groundwater is as dynamic as soil moisture, and it has been shown that groundwater storage changes have contributed to sea level variations. Groundwater monitoring well measurements are too sporadic and poorly assembled outside of the United States and a few other nations to permit direct global assessment of groundwater variability. However, observational estimates of terrestrial water storage (TWS) variations from the GRACE satellites largely represent groundwater storage variations on an interannual basis, save for high latitude/altitude (dominated by snow and ice) and wet tropical (surface water) regions. A figure maps changes in mean annual TWS from 2009 to 2010, based on GRACE, reflecting hydroclimatic conditions in 2010. Severe droughts impacted Russia and the Amazon, and drier than normal weather also affected the Indochinese peninsula, parts of central and southern Africa, and western Australia. Groundwater depletion continued in northern India, while heavy rains in California helped to replenish aquifers that have been depleted by drought and withdrawals for irrigation, though they are still below normal levels. Droughts in northern Argentina and western China similarly abated. Wet weather raised aquifer levels broadly across western Europe. Rains in eastern Australia caused flooding to the north and helped to mitigate a decade long drought in the south. Significant reductions in TWS seen in the coast of Alaska and the Patagonian Andes represent ongoing glacier melt, not groundwater depletion. Figures plot time series of zonal mean and global GRACE derived non-seasonal TWS anomalies (deviation from the mean of

  9. Taking the trophic bypass: aquatic-terrestrial linkage reduces methylmercury in a terrestrial food web.

    Science.gov (United States)

    Bartrons, Mireia; Gratton, Claudio; Spiesman, Brian J; Vander Zanden, M Jake

    2015-01-01

    Ecosystems can be linked by the movement of matter and nutrients across habitat boundaries via aquatic insect emergence. Aquatic organisms tend to have higher concentrations of certain toxic contaminants such as methylmercury (MeHg) compared to their terrestrial counterparts. If aquatic organisms come to land, terrestrial organisms that consume them are expected to have elevated MeHg concentrations. But emergent aquatic insects could have other impacts as well, such as altering consumer trophic position or increasing ecosystem productivity as a result of nutrient inputs from insect carcasses. We measure MeHg in terrestrial arthropods at two lakes in northeastern Iceland and use carbon and nitrogen stable isotopes to quantify aquatic reliance and trophic position. Across all terrestrial focal arthropod taxa (Lycosidae, Linyphiidae, Acari, Opiliones), aquatic reliance had significant direct and indirect (via changes in trophic position) effects on terrestrial consumer MeHg. However, contrary to our expectations, terrestrial consumers that consumed aquatic prey had lower MeHg concentrations than consumers that ate mostly terrestrial prey. We hypothesize that this is due to the lower trophic position of consumers feeding directly on midges relative to those that fed mostly on terrestrial prey and that had, on average, higher trophic positions. Thus, direct consumption of aquatic inputs results in a trophic bypass that creates a shorter terrestrial food web and reduced biomagnification of MeHg across the food web. Our finding that MeHg was lower at terrestrial sites with aquatic inputs runs counter to the conventional wisdom that aquatic systems are a source of MeHg contamination to surrounding terrestrial ecosystems.

  10. Comportamiento de comunidades de lombrices de tierra en dos sistemas ganaderos Behavior of earthworm communities in two livestock production systems

    Directory of Open Access Journals (Sweden)

    Saray Sánchez

    2011-09-01

    Full Text Available Con el objetivo de evaluar el comportamiento de comunidades de lombrices de tierra en dos sistemas ganaderos (pastizal de gramíneas y sistema silvopastoril, los cuales se manejaron para la ceba de animales vacunos y la producción de semillas, se realizó una investigación en la Estación Experimental de Pastos y Forrajes «Indio Hatuey», Matanzas. Para el estudio de las comunidades de lombrices se hicieron seis colectas. En cada una de las áreas descritas se tomaron 40 muestras de suelo, según la Metodología del Programa de Investigación Internacional «Biología y Fertilidad del Suelo Tropical». Se encontraron 297 y 740 organismos en el pastizal de gramíneas y en el sistema silvopastoril, respectivamente. La especie Onychochaeta elegans mostró una mayor abundancia proporcional en el pastizal de gramíneas; mientras que en el sistema silvopastoril se encontraron tres especies, de ellas dos típicas de zonas boscosas: Polypheretima elongata y Onychochaeta windlei; la primera tuvo un mayor valor, con diferencias significativas respecto a las especies halladas del género Onychochaeta. Se concluye que la presencia de árboles en pastizales de gramíneas contribuye a estimular los organismos del suelo, en especial las lombrices de tierra, las que desempeñan un papel importante al mejorar no solo los indicadores físicos y químicos de este, sino también como estimuladoras de otros organismos.In order to evaluate the behavior of earthworm communities in two livestock production systems (grassland and silvopastoral system, which were managed for cattle fattening and seed production, a study was conducted at the Experimental Station of Pastures and Forages «Indio Hatuey», Matanzas. For the study of the earthworm communities six collections were made. In each of the described areas 40 soil samples were taken, according to the Methodology of the International Research Program «Tropical Soil Biology and Fertility». In the grassland and

  11. Pathogenic and enzyme activities of the entomopathogenic fungus Tolypocladium cylindrosporum (Ascomycota: Hypocreales from Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Ana C Scorsetti

    2012-06-01

    Full Text Available Tolypocladium cylindrosporum is an entomopathogenic fungi that has been studied as a biological control agent against insects of several orders. The fungus has been isolated from the soil as well as from insects of the orders Coleoptera, Lepidoptera, Diptera and Hymenoptera. In this study, we analyzed the ability of a strain of T. cylindrosporum, isolated from soil samples taken in Tierra del Fuego, Argentina, to produce hydrolytic enzymes, and to study the relationship of those activities to the fungus pathogenicity against pest aphids. We have made the traditional and molecular characterization of this strain of T. cylindrosporum. The expression of hydrolase activity in the fungal strain was estimated at three incubation temperatures (4ºC, 12ºC and 24ºC, on different agar media supplemented with the following specific substrates: chitin azure, Tween ® 20, casein, and urea for chitinase, lipase, protease, and urease activity, respectively. The hydrolytic-enzyme activity was estimated qualitatively according to the presence of a halo of clarification through hydrolase action, besides was expressed semi-quantitatively as the ratio between the hydrolytic-halo and colony diameters. The pathogenicity of the fungus was tested on adults of the aphid Rhopalosiphum padi at three temperatures of incubation (4ºC, 12ºC and 24ºC. The suspension was adjusted to a concentration of 1x10 7 conidia/ml. In pathogenicity assays at seven days post-inoculation, the fungus caused the mortality of adults of Ropalosiphum padi at different temperatures also showed a broad ability to grow on several agar-culture media, supplemented with different carbon sources at the three incubation temperatures tested. Although, the growth was greater with higher incubation temperatures (with maximum levels at 24°C, the fungus reached similar colony diameters after 15 days of incubation on the medium supplemented with Tween® 20 at the lower two incubation temperatures of 4

  12. Perfil epidemiológico del accidente ofídico en las tierras bajas de Guatemala

    Directory of Open Access Journals (Sweden)

    Dennis Guerra-Centeno

    2017-03-01

    Full Text Available Se describe el perfil epidemiológico del accidente ofídico en las tierras bajas de Guatemala a partir del análisis de 305 expedientes de casos atendidos en los hospitales regionales de Escuintla y San Benito, Petén, entre 2008 y 2013. De los 305 casos, 169 correspondieron al Hospital Regional de Escuintla y 136 al Hospital Regional de San Benito Petén. Los casos del Hospital Regional de Escuintla correspondieron a pacientes provenientes de los departamentos de Escuintla, Santa Rosa, Chimaltenango, Retalhuleu, Suchitepéquez, Sacatepéquez, Sololá y Guatemala. Los casos del Hospital Regional de San Benito Petén correspondieron a pacientes provenientes del área centro y norte de Petén, y algunos referidos del área sur. La edad media de la víctima fue 25.2 años. La enfermedad afectó más a hombres (61.3% que a mujeres (38.7%. La mayoría de los afectados (28.3% eran agricultores. Las especies de serpiente que se consignaron en los expedientes con mayor frecuencia fueron Bothrops asper (serpiente barba amarilla en la región norte y Crotalus simus (serpiente cascabel en la región sur. La mayoría de las mordeduras ocurrieron en los miembros inferiores. Los eventos de mordedura ocurrieron durante el día y durante la noche en proporciones similares. El tiempo medio que tarda la víctima en llegar al hospital fue de 5.6 horas. Se describen también otros aspectos epidemiológicos y se discuten las implicaciones ecológicas y sociales de los datos generados.

  13. MIRAR, ESCOLTAR, TOCAR. POLÍTIQUES I POÈTIQUES D'ARXIU EN 'TIERRA SOLA' (2017 DE TIZIANA PANIZZA

    Directory of Open Access Journals (Sweden)

    Irene Depetris Chauvin

    2018-01-01

    Full Text Available Després d'un ardu treball d'investigació, rescat i recopilació, la cineasta xilena Tiziana Panizza va construir un arxiu conformat per 32 documentals de diferents països que van ser realitzats a l'illa de Pasqua entre 1933 i 1970. En aquestes filmacions hi ha imatges dels moai, les característiques escultures de pedra de la cultura rapanui, però amb prou feines apareixen els seus habitants, que durant més de 60 anys van ser confinats a un sector del territori i se'ls va impedir circular o abandonar la seva pròpia terra. El documental Tierra Sola (2017 explica aquesta història de subjecció tot establint vincles entre fragments dels documentals, testimonis de gent gran i el registre observacional de l'única presó que existeix avui a l'illa. Aquest article analitza les maneres en què la pel·lícula de Panizza construeix i deconstrueix l'arxiu fílmic, mitjançant una operació de muntatge que posa en evidència el caràcter colonial de la mirada etnogràfica, així com recupera la dimensió afectiva de l'arxiu i l'estatut expressiu dels seus documents, reorganitzant una escena de memòria que inclou les dimensions visuals, aurals i texturals de la cultura.

  14. Construcción e impacto sobre el ambiente: el caso de la tierra y otros materiales

    Directory of Open Access Journals (Sweden)

    Vázquez Espí, Mariano

    2001-02-01

    Full Text Available The assessment of the impact on the environment of the diverse human activities becomes more unavoidable as the signs of the ecological damage become more evident. Here, the relative merit of several formulations for the physical cost of building (embodied energy, exergy cost and matter cost of materials is analysed; it is also analysed the structure of the aggregate physical cost, including the relative evaluation of its more meaningful items. As a way of concrete examples, the energy and matter embodied into different building functions is evaluated depending on the material used (earth, steel, concrete, brick. Lastly, some conclusions about the attributes of a future, "sustainable" building are taken out.Conforme los indicios del deterioro ecológico se hacen más evidentes, la evaluación del impacto sobre el ambiente de las distintas actividades humanas se vuelve más insoslayable. Aquí se analiza el relativo mérito de distintas formulaciones del coste físico de la construcción: energía incorporada, coste exergético y coste material; también la estructura del coste físico agregado, incluyendo la valoración relativa de sus términos más significativos. Como ejemplos concretos, se evalúa la energía y la materia incorporada por distintas funciones constructivas según el material empleado (tierra, acero, ladrillo, hormigón. Finalmente, se extraen algunas conclusiones acerca de las características de una futura construcción "sostenible ".

  15. Le concept de « tierra » espagnole et le néo-wisigothisme dans le Liber regum

    Directory of Open Access Journals (Sweden)

    Gaël LE MORVAN

    2010-06-01

    Full Text Available Alors que les chroniques chrétiennes du Nord péninsulaire développent le mythe néo-wisigothique afin de légitimer le pouvoir des rois castillano-léonais et la reconquête contre les Maures, défendant ainsi une continuité ethnique et dynastique entre les Wisigoths, les Léonais et les Castillans, le Liber regum s’éloigne de cette idéologie proprement léonaise et assoit le pouvoir de la dynastie du Restaurateur navarrais García Ramírez sur une continuité de la terre et de la gent qui l’occupe. À partir de l’étude du concept de terre, le sens politique du Liber regum semble défendre les restaurateurs, et la terre navarraise se fait ainsi le creuset du territoire hispanique.Mientras que las crónicas cristianas del norte peninsular desarrollan el mito neo-visigótico para legitimar el poder de los reyes castellano-leoneses y la reconquista contra los moros, defendiendo así una continuidad étnica y dinástica entre los godos, los leoneses y los castellanos, el Liber regum se aparta de esta ideología propiamente leonesa y asienta el poder de la dinastía del Restaurador navarro García Ramírez en una continuidad de la tierra y de la gente que la ocupa. Partiendo del estudio del concepto de tierra, el sentido político del Liber regum parece defender a los restauradores, y la tierra navarra se vuelve así el crisol del territorio hispánico.

  16. Predictability of the terrestrial carbon cycle.

    Science.gov (United States)

    Luo, Yiqi; Keenan, Trevor F; Smith, Matthew

    2015-05-01

    Terrestrial ecosystems sequester roughly 30% of anthropogenic carbon emission. However this estimate has not been directly deduced from studies of terrestrial ecosystems themselves, but inferred from atmospheric and oceanic data. This raises a question: to what extent is the terrestrial carbon cycle intrinsically predictable? In this paper, we investigated fundamental properties of the terrestrial carbon cycle, examined its intrinsic predictability, and proposed a suite of future research directions to improve empirical understanding and model predictive ability. Specifically, we isolated endogenous internal processes of the terrestrial carbon cycle from exogenous forcing variables. The internal processes share five fundamental properties (i.e., compartmentalization, carbon input through photosynthesis, partitioning among pools, donor pool-dominant transfers, and the first-order decay) among all types of ecosystems on the Earth. The five properties together result in an emergent constraint on predictability of various carbon cycle components in response to five classes of exogenous forcing. Future observational and experimental research should be focused on those less predictive components while modeling research needs to improve model predictive ability for those highly predictive components. We argue that an understanding of predictability should provide guidance on future observational, experimental and modeling research. © 2014 John Wiley & Sons Ltd.

  17. Numerical simulations for terrestrial planets formation

    Directory of Open Access Journals (Sweden)

    Ji J.

    2011-07-01

    Full Text Available We investigate the formation of terrestrial planets in the late stage of planetary formation using two-planet model. At that time, the protostar has formed for about 3 Myr and the gas disk has dissipated. In the model, the perturbations from Jupiter and Saturn are considered. We also consider variations of the mass of outer planet, and the initial eccentricities and inclinations of embryos and planetesimals. Our results show that, terrestrial planets are formed in 50 Myr, and the accretion rate is about 60%–80%. In each simulation, 3–4 terrestrial planets are formed inside “Jupiter” with masses of 0.15–3.6 M⊕. In the 0.5–4 AU, when the eccentricities of planetesimals are excited, planetesimals are able to accrete material from wide radial direction. The plenty of water material of the terrestrial planet in the Habitable Zone may be transferred from the farther places by this mechanism. Accretion may also happen a few times between two giant planets only if the outer planet has a moderate mass and the small terrestrial planet could survive at some resonances over time scale of 108 yr.

  18. El río Duratón, un río de frontera en la Reconquista. Repoblación y colonización de Sepúlveda y sus tierras

    OpenAIRE

    Bermejo de Frutos, José María

    2012-01-01

    El río Duratón y sus tierras, en especial la Comunidad de Villa y Tierra de Sepúlveda, son un espacio reducido en la geografía de España y en su historia. Sin embargo, su importancia en el devenir de la reconquista y de la historia peninsular ha sido relevante dando mucho que hablar a los historiadores. Estamos ante un río muy pequeño, río de “frontera entre fronteras”: la del Duero y la del sistema Central. Las aguas del Duratón a su paso por las comarcas de su entorno han regado sus tierras...

  19. Caracterización de los sistemas de producción de ganado bovino en tierra caliente del estado de Michoacán

    OpenAIRE

    Molina Mercado, Víctor Manuel

    2011-01-01

    El objetivo del presente trabajo fue determinar cuales son los principales sistemas de producción bovina en la Región de Tierra en el estado de Michoacán. El trabajo fue realizado en los municipios de Caracúaro, Nocupetaro, Huetamo, San Lucas, Tiquicheo y Tuzantla, pertenecientes al Distrito de Desarrollo Rural 093. Se utilizó de metodología la técnica rural de investigación participativa donde de manera interactiva se trabajo con un total de 400 productores de los seis municipios, y a los...

  20. Mujeres de todos los colores de la tierra: En defensa del territorio, los derechos étnicos y de género

    Directory of Open Access Journals (Sweden)

    Georgina Aimé Tapia González

    2010-05-01

    Full Text Available Desde las condiciones de pobreza, discriminación y despojo en que han sido marginados los pueblos originarios, se levantan voces de mujeres que, junto a las demandas de autonomía, salud, educación, derecho a la tierra y preservación de los recursos naturales compartidas con los varones, plantean reivindicaciones de género. Aquí me referiré específicamente al movimiento neozapatista en México, el cual propone prácticas feministas y ecológicas alternativas ante el desarrollismo racista, sexista y ecocida de la globalización neoliberal.

  1. Agua y tierras secas. Lecturas críticas sobre la escasez hídrica en el departamento Lavalle (Mendoza)

    OpenAIRE

    María Virginia Grosso Cepparo

    2017-01-01

    La escasez de agua constituye un problema de Estado en las tierras secas de la provincia de Mendoza, Argentina. Sin embargo, mientras el gobierno local naturaliza y difunde la escasez como un problema “de todos”, los contrastes en el acceso al agua plantean interrogantes respecto de su universalidad. Por ello, este trabajo busca repensar la escasez hídrica desde una perspectiva multidimensional que amplíe el abordaje biofísico. Específicamente, se busca analizar la mirada oficial respecto de ...

  2. CAPACIDAD DE LAS TIERRAS PARA USO AGRÍCOLA EN LA SUBCUENCA MEDIA-ALTA DEL RÍO PIRRÍS, LOS SANTOS, COSTA RICA

    Directory of Open Access Journals (Sweden)

    Miguel Chinchilla

    2011-01-01

    Full Text Available El uso de la tierra en la subcuenca mediaalta del río Pirrís, está diferenciado por la altitud sobre el nivel del mar. Entre los 1075 y 1700 m de elevación, la principal actividad agrícola es el cultivo del café, desarrollado sobre suelos arcillosos del orden de los Ultisoles con importantes manifestaciones de erosión. Por encima de los 1700 m y hasta los 3100 m dominan los Andisoles, Inceptisoles y Entisoles, utilizados con bosques, pastos, frutales de altura, algo de hortalizas, floricultura, piscicultura, hoteles de montaña, producción de carbón en trincheras y donde existe menor pérdida de suelo. En general, el área se caracteriza por las tierras montañosas con fuerte pendiente (30 a 60% y unos pocos relieves suaves que ocupan valles profundos con terrazas recientes. Rasgos visibles permitieron estimar que en suelos agropecuarios hay un 60% de erosión moderada (laminar y en surcos y un 18% de severa a muy severa, sin considerar una erosión lineal que se presenta por caminos mal diseñados, ausencia de cunetas, excavaciones para infraestructura y deslizamientos activos que provocan remociones de suelo en grandes proporciones. En cuanto a profundidad efectiva, los suelos profundos significan el 44% del área, mientras que un 38% son moderadamente profundos y el 17% son poco profundos a superficiales. Las calicatas localizadas en la parte media alta de la subcuenca señalan un 33% de suelos con fertilidad baja y 52% de fertilidad muy baja. Considerando los factores pendiente, erosión actual visible, fertilidad y profundidad de suelos, la capacidad de uso de las tierras agrícolas en el área estudiada, revela que 1% de las tierras son clase III; 2% clase V; 8% clase VIII; 26% clase VII y 63% de clases IV y VI

  3. Protesta y movilización legal contra megaproyectos en México: El Frente de Pueblos en Defensa de la Tierra (2001-2002)

    OpenAIRE

    Martínez, Carlos Ramón Meza; Guzmán, Jesús Carlos Morales

    2017-01-01

    Resumen En México, algunos movimientos sociales han incorporado la movilización legal como parte de sus repertorios de contención con el objeto de que sus demandas sean atendidas. El artículo analiza las oportunidades y límites que brindan las Estructuras de Oportunidad Política y Legal del Frente de Pueblos en Defensa de la Tierra que se opuso al megaproyecto del Nuevo Aeropuerto de la Ciudad de México (2001-2002). Abstract In México some social movements have incorporated the legal mobil...

  4. CARACTERÍSTICAS DEL QUESO TEPEQUE DE LA TIERRA CALIENTE DE MICHOACÁN: UN QUESO PRODUCIDO EN UN SISTEMA SILVOPASTORIL INTENSIVO

    OpenAIRE

    Alejandra Donají Solís Méndez

    2013-01-01

    El objetivo del presente estudio fue describir las características del Queso Tepeque de la Tierra Caliente del Estado de Michoacán en términos de su región de origen, proceso de manufactura, características fisicoquímicas y microbiológicas, y documentar los cambios atribuibles a la implementación de un sistema silvopastoril intensivo (SSPi) para la alimentación del ganado. La metodología consintió en visitar la zona de estudio para recolectar información sobre el territorio donde se produce e...

  5. Modelación de sistemas de puesta a tierra para evaluación de sobretensiones transitorias; Modelling large grounding systems to evaluate transient voltages

    Directory of Open Access Journals (Sweden)

    Yandi Anibal Gallego Landera

    2015-04-01

    Full Text Available En plantas generadoras y en subestaciones se requieren sistemas de puesta a tierra (SPT espaciosos, con configuraciones complejas como parte del sistema de protección contra rayos. Las corrientes provocadas por una descarga atmosférica pueden causar altas tensiones en los cables de señales ubicados cerca de los SPT. Estas tensiones transitorias pueden causar falsas señales, las cuales provocan un mal funcionamiento de la instrumentación electrónica. Determinar medidas de protección contra rayos requiere del conocimiento de la máxima elevación de la tensión entre el SPT y la tierra remota. El presente trabajo propone una metodología para analizar el comportamiento transitorio de redes de tierra. La técnica se basa en considerar los diferentes segmentos de la malla de tierra como elementos de líneas de transmisión. Para desarrollar esta metodología se utilizó el software MATLAB-Simulink. Los resultados se validan por comparación con modelos basados en la teoría del campo electromagnético publicados en la literatura. In generating plants and substations spacious grounding systems with complex configuration as part of the protection system against lighting, are required. The current caused by an atmospheric discharge can cause high voltages in the signal cables located near the grounding systems. These transient voltages may be the reason for the occurrence of false signals, which can cause malfunctioning and of electronic instruments. The knowledge of maximum elevation of voltage between the grounding systems and the remote ground is required to determine protection against lightning. This paper proposes a methodology to analyze the transient behavior of grounding grid. The technique is based on considering the different segments of the ground grid as elements of transmission lines. For modeling the grounding systems behavior in its transient state faster, the MATLAB-Simulink software was used. The results were validated by

  6. A molecular palaeobiological exploration of arthropod terrestrialization

    DEFF Research Database (Denmark)

    Lozano-Fernandez, Jesus; Carton, Robert; Tanner, Alastair R.

    2016-01-01

    to the colonization of land is the most likely scenario.Molecular clock analyses confirmed an origin for the three terrestrial lineages bracketed between the Cambrian and the Silurian. While molecular divergence times for Arachnida are consistent with the fossil record,Myriapoda are inferred to have colonized land...... earlier, substantially predating trace or body fossil evidence. An estimated origin of myriapods by the Early Cambrian precedes the appearance of embryophytes and perhaps even terrestrial fungi, raising the possibility that terrestrialization had independent origins in crown-group myriapod lineages......, consistent with morphological arguments for convergence in tracheal systems. This article is part of the themed issue ‘Dating species divergences using rocks and clocks’....

  7. UN MÉTODO DE GESTIÓN AMBIENTAL PARA EL TRATAMIENTO Y LA DISPOSICIÓN FINAL ADECUADA DE UN RESIDUO PELIGROSO. CASO: TIERRA FULLER CONTAMINADA CON ACEITE DIELÉCTRICO

    Directory of Open Access Journals (Sweden)

    AGUDELO EDISON ALEXANDER

    2012-11-01

    Full Text Available La gestión ambiental de un residuo peligroso comprende diferentes etapas: generación, minimización, transporte, valorización, tratamiento y disposición. Este trabajo explora dos tecnologías para el tratamiento y disposición final de un residuo peligroso (RESPEL o tierra Fuller contaminada con aceite dieléctrico: una físico-química y otra biológica. Para la tecnología físico-química se usó hexano como solvente y se alcanzaron remociones del aceite dieléctrico del orden del 87% en la tierra Fuller contaminada, con una relación tierra Fuller: solvente de 1:8 p/v, una velocidad de agitación de 100 rpm y un tiempo de contacto de 30 min. La calidad del aceite dieléctrico recuperado no es apta para su uso nuevamente en equipos eléctricos, por su baja rigidez dieléctrica, baja densidad y color desfavorable. La tierra Fuller recuperada registró una densidad aparente de 0.641 gr/ml, una densidad real de 2.231 gr/ml y una porosidad de 72.075 %, lo que indica que dicha tierra esta muy cercana en sus características físicas a la tierra Fuller limpia.Para la tecnología biológica se trató la tierra contaminada en un biorreactor biológico de tierra activada, evaluando la velocidad de agitación y el tiempo de degradación necesario para alcanzar los niveles de descontaminación adecuados que permitan disponer el residuo en un relleno sanitario convencional o una escombrera sin riesgo alguno para la salud de los ecosistemas y el ser humano. Se alcanzaron remociones en este sistema del orden de 49.68%, aunque no se alcanzó los niveles de limpieza exigidos por la Resolución 1170 de 1997 del DAMA. El resultado es importante en cuanto se creía que altas concentraciones de hidrocarburos (superiores al 10% son inhibitorias de la actividad biológica. Se hizo el seguimiento cromatográfico a 10 especies de hidrocarburos presentes en el aceite dieléctrico que son importantes dentro de este producto.

  8. Elementos para volver a pensar lo comunal: nuevas formas de acceso a la tierra y presión sobre el recurso en las comunidades campesinas de Colán y Catacaos

    OpenAIRE

    María Luisa Burneo

    2013-01-01

    El presente artículo plantea que viene ocurriendo una transformación de la relación entre la tierra, los comuneros y las comunidades que, en el caso de la costa norte peruana, se vincula con una doble dinámica: (i) la creciente presión externa sobre el recurso por capitales privados nacionales y trasnacionales, y (ii) el surgimiento de nuevas formas y motivaciones de acceso a la tierra por los comuneros. En este escenario, las comunidades buscan desarrollar mecanismos de contención que, sin e...

  9. Análisis de las concepciones que sostienen las políticas de tenencia de la tierra del gobierno local en el Cantón Pimampiro a partir el año 2001

    OpenAIRE

    Hidalgo Mantilla, Elbio

    2006-01-01

    En la actualidad dentro del país dos son las instituciones que regulan la tenencia de la tierra: El Instituto Nacional de Desarrollo Agrario (INDA) y el Ministerio del Ambiente. Cada una de estas dos instituciones tiene su propia jurisdicción y competencia, así, la competencia del Ministerio del Ambiente se refiere a la adjudicación de tierras bajo el patrimonio Forestal del Estado a empresas forestales, y a grupos que se organicen con una finalidad forestal; mientras que el INDA puede adjudi...

  10. Como campesinos comuneros se convierten en dueños de tierras de exlatifundio: el caso del fundo puerto oscuro en el semiárido Norte Chico de Chile

    OpenAIRE

    GALLARDO FERNÁNDEZ, GLORIA L.

    2011-01-01

    Los procesos de reforma agraria (1965-1973) y de “contra reforma” (1973-1981) de la dictadura de PINOCHET tuvieron consecuencias imprevistas sobre la estructura predominantemente bimodal de tenencia de la tierra del semiárido Norte Chico de Chile. Creando una fórmula legal cuyo central elemento consiste en la indivisibilidad de la tierra como forma de manejo de este recurso natural, mediante las sociedades de secano, el estado juega un rol central en la nueva estructura agraria local, confirm...

  11. El descubrimiento de las proporciones establecidas por Vitrubio y Alberti en las tierras del maestrazgo de montesa gracias a los levantamientos gráficos arquitectónicos

    OpenAIRE

    Máñez Pitarch, María Jesús; Garfella Rubio, José Teodoro

    2013-01-01

    La orden de Montesa fue una orden religiosa militar creada en el siglo XlV. Una amplia zona del norte de la provincia de Castellón se denominó Maestrazgo de Montesa. Y es en estas tierras donde se encuentra una de las iglesias renacentistas más importantes de las tierras valencianas: la parroquial de Vistabella del Maestrazgo, construida a principios del siglo XVII. Un exhaustivo levantamiento gráfico arquitectónico realizado tanto con métodos tradicionales, como con modernas t...

  12. Dinámica reciente de la concentración de la propiedad y uso de la tierra en Colombia. Algunas reflexiones a propósito de la especialización productiva

    OpenAIRE

    Suescún, Carlos Alberto

    2011-01-01

    La dinámica histórica de desigualdad rural en Colombia, ha estado caracterizada principalmente por una persistente concentración de la propiedad de la tierra, que en tiempo reciente ha estado impulsada por factores como el despojo de tierras y la profundización de las desigualdades en el sector rural en un contexto de violencia y narcotráfico. A estos factores estructurales, en las últimas dos décadas se han sumado dos adicionales que han profundizado las desigualdades: la especialización pro...

  13. Terrestrial propagation of long electromagnetic waves

    CERN Document Server

    Galejs, Janis; Fock, V A

    2013-01-01

    Terrestrial Propagation of Long Electromagnetic Waves deals with the propagation of long electromagnetic waves confined principally to the shell between the earth and the ionosphere, known as the terrestrial waveguide. The discussion is limited to steady-state solutions in a waveguide that is uniform in the direction of propagation. Wave propagation is characterized almost exclusively by mode theory. The mathematics are developed only for sources at the ground surface or within the waveguide, including artificial sources as well as lightning discharges. This volume is comprised of nine chapte

  14. Evolutionary tracks of the terrestrial planets

    International Nuclear Information System (INIS)

    Matsui, Takafumi; Abe, Yutaka

    1987-01-01

    On the basis of the model proposed by Matsui and Abe, the authors show that two major factors - distance from the Sun and the efficiency of retention of accretional energy - control the early evolution of the terrestrial planets. A diagram of accretional energy versus the optical depth of a proto-atmosphere provides a means to follow the evolutionary track of surface temperature of the terrestrial planets and an explanation for why the third planet in our solar system is an 'aqua'-planet. 15 refs; 3 figs

  15. Constraining the Late Mesozoic and Early Tertiary Tectonic Evolution of Southern Mexico: Structure and Deformation History of the Tierra Caliente Region.

    Science.gov (United States)

    Cabral-Cano; Draper; Lang; Harrison

    2000-07-01

    We analyze the structure and assess the deformation history of the Tierra Caliente Metamorphic Complex (TCMC) of southern Mexico, where Laramide accretion of exotic terranes is in debate. The TCMC consists of a south-plunging antiform fault that is bounded on both its eastern and western flanks. Tierra Caliente Metamorphic Complex rocks show at least two phases of compressional deformation. The first and most prominent records a mean tectonic transport direction of 068 degrees. This phase is responsible for east-verging asymmetrical folding and thrusting of both metamorphic and superjacent sedimentary rocks. The second phase has an average transport direction of 232 degrees and is restricted to the western portion of the TCMC. A third phase is responsible for normal faulting. Lack of discernible deformation before Late Cretaceous time indicates that the main deformation phase is coincident with Laramide orogenesis elsewhere in the North American Cordillera. The stratigraphy, structure, and deformational history of the TCMC do not require accretion of exotic terranes. We explain the Mesozoic tectonostratigraphic evolution of the TCMC in terms of deposition and deformation of Mesozoic volcanic and sedimentary strata over the attenuated continental crust of the North American plate.

  16. Influencia de la litología en las consecuencias del abandono de tierras de cultivo en medios mediterráneos semiáridos

    Directory of Open Access Journals (Sweden)

    Asunción Romero Díaz

    2003-01-01

    Full Text Available Se analiza la importancia que el abandono de tierras ha tenido en la Región de Murcia en los últimos años, los efectos que ocasiona el abandono y los ensayos de actuaciones que se han realizado en campos abandonados y degradados para su recuperación. En las dos últimas décadas, posiblemente, se han abandonado en la Región de Murcia mas de 100.000 has, y estas tierras se localizan en áreas de suelos muy degradados y que pueden ser muy afectadas por procesos de erosión. Las experiencias realizadas en campos abandonados muestran respuestas muy diferentes en suelos con substrato calizo o margoso. Mientras que el abandono en suelos calizos, desde un punto de vista erosivo, puede ser positivo; en suelos margosos es muy negativo. En estos últimos suelos, en el mejor de los casos, es necesario un periodo muy dilatado de años para su recuperación; siendo lo más frecuente la aparición y extensión de importantes procesos y formas de erosión. Se ha demostrado como la adición de residuos sólidos urbanos es una forma muy efectiva de regeneración de suelos y cubierta vegetal en condiciones mediterráneas semiáridas.

  17. The certainty of existence according to the deconstruction of past time in Tierra de nadie by Ángel García López

    Directory of Open Access Journals (Sweden)

    Maria Teresa Navarrete Navarrete

    2012-12-01

    Full Text Available The Spanish poet Ángel García López began writing in the 1960’s and continues to write today. Although his poetical corpus is extensive, this article focuses on a specifi c book of poetry, Tierra de nadie, which is his second one. Tierra de nadie turns on the paradox of writing both from and into past experience. García López attempts to describe that experience using the feeling of terrible bereavement. However, the past time turns into a creative space where memory becomes the focal point of the poetry, which in García López is always a form of displacement and recognition. The poetic is subsumed in the domain of memory. Thus the poet is able to travel through the rooms of childhood, the landscapes of southern Andalusia and reproduce the sounds of the speech of Western Andalusia. Aft er capturing in this a memory of the past, the poet lays it bare to reveal the origin of its being. The memories of the past go beyond their traditional sense and acquire a transcendental meaning. Only when the lost past is integrated into present time, can the lyric voice take a step towards full maturity and act out new scenes in the stage of life.

  18. Poder y centros de representación: castros y castillos en la Toscana y Tierra de Campos (siglos X-XII

    Directory of Open Access Journals (Sweden)

    Pérez Rodríguez, María

    2015-12-01

    Full Text Available Since Toubert published his research on Lazio, the concept of incastellamento has become an important starting point to explain Feudalism in good part of Medieval Mediterranean Europe. Far from to trying to validate the viability of this explanatory model for the Iberian Peninsula, we have conducted an analysis of the role of fortresses and the nature of bonds between monarchy and the aristocracies from the Toscana and the Cea’s bank, in the Tierra de Campos region. Our main purpose is to observe the existence of similarities and differences between both areas and their incidence in the development of Feudal logics.Desde que Pierre Toubert publicara su estudio sobre el Lazio, el incastellamento se convirtió en un importante punto de partida a la hora de explicar el feudalismo en buena parte del mundo mediterráneo. Lejos de intentar validar su viabilidad en la Península Ibérica, se ha llevado a cabo un estudio sobre el papel ejercido por las fortificaciones y la naturaleza de los vínculos entre monarquía y aristocracias en la región de la Toscana y la ribera del Cea, en Tierra de Campos. El objetivo principal es observar las semejanzas y diferencias existentes entre ambas zonas y su incidencia en el desarrollo del feudalismo.

  19. Reciente invasión del Archipiélago de Tierra del Fuego por la avispa Vespula germanica (Hymenoptera: Vespidae

    Directory of Open Access Journals (Sweden)

    Francisco J. SOLA

    2015-01-01

    Full Text Available Vespula germanica es una especie invasora de nivel mundial que ha sido detectada en la Patagonia continental de la Argentina y Chile. En este trabajo, ampliamos el rango de distribución de este véspido de la Patagonia, al Archipiélago de Tierra del Fuego. Indicamos ubicación, año y ambiente de cada avistamiento y/o captura. El patrón de expansión indicaría que esta especie está bien establecida tanto en áreas naturales como antrópicas, y probablemente ha dependido del transporte humano para llegar desde el continente. Esta comunicación breve sirve también para tomar medidas prácticas de mitigación y control de esta especie, incluyendo información básica para que la ciudadanía tome conciencia sobre su presencia y esto ayude a evitar su transporte a nuevos lugares. Finalmente, se recomienda mayor investigación para el manejo y control de esta especie invasora en Tierra del Fuego.

  20. Tierra y revolución. La campaña salteña en las primeras décadas del siglo XIX

    Directory of Open Access Journals (Sweden)

    Sara Emilia Mata

    2016-09-01

    Full Text Available La formación de la Junta de Gobierno en Buenos Aires en 1810 dio inicio a un proceso político que adquirió derroteros diversos en el interior del extenso territorio perteneciente al Virreinato del Río de la Plata. Al igual que en las provincias del Alto Perú,  la jurisdicción de Salta fue escenario  de una guerra de recursos de la cual participó la población rural integrando las milicias provinciales o “Escuadrones Gauchos”.  Interesa entonces observar en qué medida el conflicto bélico agudizó y puso en evidencia las tensiones existentes por los derechos de propiedad y usufructo de la tierra ya manifestadas a fines del siglo XVIII, particularmente en el valle de Lerma, y su incidencia en las disputas en torno a la tierra que tuvieron lugar luego de concluida la guerra en la provincia de Salta.

  1. Entre el reconocimiento y el abandono. La situación del Camino Real de Tierra Adentro en el norte de Guanajuato.

    Directory of Open Access Journals (Sweden)

    Miguel Santos Salinas Ramos

    2016-01-01

    Full Text Available El Camino Real de Tierra Adentro fue la ruta principal que por más de tres siglos permitió la comunicación, el comercio y el movimiento de personas entre el centro de la Nueva España y el norte del virreinato. Esta ruta ha sido estudiada por historiadores, arqueólogos y personas interesadas en la conservación, protección y divulgación del patrimonio cultural de México. El objetivo del presente texto es analizar el proceso por el cual el Camino Real de Tierra Adentro dejó de ser solo un tema de interés histórico, para ser considerado Patrimonio de la Humanidad. Para ello revisaré una serie de publicaciones que nos permitan conocer los diferentes puntos de vista desde los cuales se ha analizado este tema y se examinarán una serie de documentos emitidos por UNESCO e ICOMOS que muestran el interés de algunas organizaciones respecto al Camino Real.

  2. EFICACIA EN LA RESTITUCIÓN DE TIERRAS A VÍCTIMAS DE DESPLAZAMIENTO FORZADO DE OCAÑA NORTE DE SANTANDER

    Directory of Open Access Journals (Sweden)

    Fidencio Suarez Vargas

    2016-02-01

    Full Text Available RESUMEN En este trabajo investigativo desarrollamos el tema referente a la eficacia en la restitución de tierras a las víctimas de desplazamiento forzado de la ciudad de Ocaña, Norte de Santander, durante el año 2014. A través del mismo nos propusimos compendia y analizar los distintos componentes jurídicos referentes al tema de estudio, con el objeto de establecer su funcionalidad en el municipio de Ocaña. Por medio del análisis cuantitativo de las cifras que reportan los juzgados de restitución de tierras respecto al número de reclamaciones realizadas a partir de la expedición de la ley, número de sentencias y número de restituciones llevadas a cabo, establecimos el nivel de eficacia del estado en lo que respecta al cumplimiento de este derecho principalísimo a las víctimas del conflicto armado colombiano. Finalmente, conoceremos que el grado de cumplimiento por parte del estado a las víctimas de desplazamiento del municipio de Ocaña es inexistente.

  3. Modelado, Simulación y Control de Satélites en los Puntos de Lagrange del Sistema Tierra - Luna

    Directory of Open Access Journals (Sweden)

    F. Alonso Zotes

    2011-07-01

    Full Text Available Resumen: El objetivo de este artículo es modelar, analizar y controlar una constelación de cinco satélites, situados en los puntos de Lagrange del sistema Tierra – Luna. El modelo se ha desarrollado incluyendo efectos complejos no considerados habitualmente, como el viento solar, la no esfericidad de los planetas y la deriva de la órbita lunar, para hacerlo más realista. Sobre los satélites se ejerce una propulsión continua, calculada por medio de controladores tipo PD, tanto convencionales como borrosos, y cuya finalidad es situar y mantener a cada satélite en su punto de Lagrange frente a las inestabilidades y derivas inherentes al sistema. El sistema completo se ha implementado en el lenguaje de modelado Modelica, para el que se han creado una serie de elementos aeroespaciales, y las simulaciones se han desarrollado con el software Dymola. Tanto con los controladores clásicos como con los borrosos se han obtenido muy buenos resultados. Palabras clave: modelado, simulación, control borroso, satélites, puntos de Lagrange, sistema Tierra-Luna

  4. LA MEMORIA DE LAS TIERRAS ANTIGUAS TOCANDO A LAS PUERTAS DEL DERECHO. POLÍTICAS DE LA MEMORIA MAPUCHE EN LA TRANSICIÓN CHILENA

    Directory of Open Access Journals (Sweden)

    VICTOR TOLEDO LLANCAQUEO

    2011-06-01

    Full Text Available Las reclamaciones colectivas de los pueblos indígenas de una justicia histórica, tienen una doble dimensión, de reconocimiento y reparación. Reconocimiento de su preexistencia como pueblos y de sus derechos, reconocimiento de una historia de atropellos y del memorial de agravios, y de las obligaciones de reparación. Reparación que tiene como una de sus exigencias centrales la restitución de sus territorios ancestrales, esos que están en la memoria y que forman parte de su identidad cultural. Restitución que constituye la precondición de una reconciliación. ¿Qué ha ocurrido con el derecho a la memoria de los pueblos indígenas en las transiciones en América Latina?, ¿Ha habido justicias restaurativas en estos casos?, En el presente ensayo solo haremos referencia al caso mapuche, bajo jurisdicción del estado de Chile, y a las políticas de la memoria indígena en la transición democrática. Acotando aún más, nos referiremos solo a la memoria de las tierras, al nütram de las tierras antiguas, a su dramática puesta al centro de la plaza pública.

  5. Aproximación a la patología presentada en las construcciones de tierra. Algunas recomendaciones de intervención

    Directory of Open Access Journals (Sweden)

    Rodríguez, M. A.

    2011-09-01

    Full Text Available This article shows several points to consider in the study and conservation of the heritage of earth. We show the most characteristic damages of these buildings and we propose some recommendations for the correct diagnostic of their pathology. Finally, some recommendations for the conservation of this heritage are given.

    En el presente artículo se ponen de manifiesto una serie de aspectos que es necesario tener presente a la hora de acometer un estudio sobre la patología presentada en las construcciones de tierra en general, y patrimoniales en particular. Para ello, y tras proponer una serie de recomendaciones que contribuyan a un correcto diagnóstico de la patología presentada, se identifican las lesiones más características de este tipo de construcciones. Por último, se proponen algunas pautas de intervención en función de la patología presentada, así como recomendaciones de carácter general para la conservación del patrimonio de estructuras de tierra.

  6. Información molecular obtenida a partir de pieles de la colección del Museo Regional Fagnano, Río Grande, Tierra del Fuego

    Directory of Open Access Journals (Sweden)

    Petrigh, Romi

    2014-10-01

    Full Text Available En el presente trabajo se aplicaron técnicas moleculares sobre muestras poco conservadas de pieles depositadas en la colección del Museo Regional Monseñor Fagnano, Tierra del Fuego, Argentina, con el objetivo de identificar la especie con la que fueron confeccionadas. Se extrajeron pelos de mantas realizadas con pieles de guanaco (Lama guanicoe por Selk’nam y de una piel de puma (Puma concolor procedente de la provincia de Santa Cruz. Ambas muestras se encontraban almacenadas en el Museo Regional Monseñor Fagnano y en la Misión Salesiana Candelaria en Rio Grande, Tierra del Fuego, Argentina. La extracción de ADN de los fragmentos de pelos de 5mm de longitud se realizó en un buffer de lisis PCR-compatible. Se amplificaron por PCR fragmentos específicos de ADN mitocondrial y se secuenciaron. Las secuencias fueron comparadas con las depositadas en la base de secuencias de nucleótidos del National Center for Biotechnology Information (NCBI de Estados Unidos. La aplicación de técnicas moleculares permitió recuperar secuencias de ADN de muestras de pieles con un estado de conservación poco óptimo para análisis genéticos, pudiendo extenderse a otras fuentes de pelos como las fibras textiles de origen arqueológico de la región.

  7. Ejércitos irregulares y organización campesina: Guáimaro, el camino hacia la restitución del derecho a la tierra

    Directory of Open Access Journals (Sweden)

    Patricia Stella Jaramillo Guerra

    2010-07-01

    Full Text Available Este artículo recoge los resultados preliminares del proyecto de Extensión “Estructura Agraria, soberanía alimentaria y mujer rural”, donde se relaciona el impacto del paramilitarismo en un corregimiento ribereño del departamento del Magdalena. En el decurso del proceso investigativo se encontró que, luego de un dramático capítulo de violencia y desplazamiento paramilitar, mediante el cual se evidenció empíricamente la concreción de estos grupos irregulares como empresas armadas, generaron procesos de apropiación forzosa de la tierra, robusteciendo aún más el esquema de concentración que históricamente se ha consolidado. Justamente en este contexto se ha presentado un interesante proceso de movilización campesina que busca desarticular el curso de su descomposición descendente, al colocar la tierra, en primer lugar, como fin esencial en sus dimensiones productivas pero identitarias, por sobre todo.

  8. LA CONSERVACIÓN DE LA TIERRA ¿PUEDE SER UNA RELACIÓN ENTRE CAMPESINOS, PLANIFICADORES AGROPECUARIOS Y EXTENSIONISTAS?

    Directory of Open Access Journals (Sweden)

    Elko Bergsma

    2003-12-01

    Full Text Available En los trabajos de extensión, realizados en Tailandia en 1983, se produce un cambio en el enfoque de los mismos que pasa de la actitud de los trabajadores rurales hacia la actitud de los expertos. Upayokin et. al. (12 en un estudio realizado en el noreste de Tailandia, llegan a la conclusión que la motivación para incrementar la conservación debe ser puesta en los valores culturales, sociales e ideológicos de la gente, y que los conservacionistas del suelo deben descubrir como motivar a los campesinos en estas prácticas. El experto debe ampliar y no limitar su relación con el productor experimentado. Es sabido que el riesgo de erosión de los sistemas de cultivo, la capacidad y la tenencia de la tierra afectan a las políticas de conservación. Sin embargo el principal factor es el acercamiento de los extensionistas a los productores (Fig. 1. La actitud de los asesores tiene una importante influencia en la creación e implementación de prácticas de conservación, en la perspectiva para la protección a largo plazo y en el uso sustentable de la tierra (1.

  9. USOS DE LA TIERRA, CONFLICTO Y PODER POLÍTICO EN LA FRONTERA AGRÍCOLA DEL ALTO SINÚ 1940-1970

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    Ruth Esther Gutierrez

    2016-08-01

    Full Text Available El presente artículo presenta un recorrido histórico, a partir del cual aborda las perspectivas historiográficas desde donde se ha estudiado la manera cómo la subregión del alto Sinú se convirtió en una frontera agrícola, que a mediados del siglo XX y más específicamente entre 1940 y 1970, despertó un profundo interés en las élites económicas y políticas nacionales y regionales, quienes abiertamente iniciaron un proceso de acaparamiento de las tierras e instauración de sistemas laborales que incluían la sujeción de la mano de obra a las corrientes bipartidistas liberales y conservadoras. Así mismo, se presentan las formas contestatarias que adoptaron los campesinos del alto Sinú frente al monopolio de la tierra ostentado por gamonales y funcionarios públicos.

  10. 3D modelling of the Salesian mission Nuestra Señora de la Candelaria cemetery (Río Grande, Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Melisa A. Salerno

    2017-07-01

    Full Text Available The Salesian mission Nuestra Señora de La Candelaria operated between the late 19th and the mid-20th centuries in Río Grande (Tierra del Fuego, Argentina. Its cemetery still holds the remains of indigenous and religious people who lived in the institution, and settlers who lived nearby. For some years, the place has received the attention of a research project interested in discussing the dynamics of colonial relationships in Tierra del Fuego. The cemetery has a long history of changes, and even though it was declared part of the national and provincial heritage, its preservation conditions are relatively poor. In this article we present the work carried out to produce a 3D model of the cemetery, combining information obtained by planialtimetric and photographic survey. The result represents a detailed and photorealistic record of the materiality of the cemetery at present. Therefore, it does not only provide a relevant tool to colaborate in the promotion and protection of the archaeological heritage. It also provides a platform for future 3D modelling of historical images of the cemetery, with different research goals.

  11. Pathogenic and enzyme activities of the entomopathogenic fungus Tolypocladium cylindrosporum (Ascomycota: Hypocreales from Tierra del Fuego, Argentina

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    Ana C Scorsetti

    2012-06-01

    Full Text Available Tolypocladium cylindrosporum is an entomopathogenic fungi that has been studied as a biological control agent against insects of several orders. The fungus has been isolated from the soil as well as from insects of the orders Coleoptera, Lepidoptera, Diptera and Hymenoptera. In this study, we analyzed the ability of a strain of T. cylindrosporum, isolated from soil samples taken in Tierra del Fuego, Argentina, to produce hydrolytic enzymes, and to study the relationship of those activities to the fungus pathogenicity against pest aphids. We have made the traditional and molecular characterization of this strain of T. cylindrosporum. The expression of hydrolase activity in the fungal strain was estimated at three incubation temperatures (4ºC, 12ºC and 24ºC, on different agar media supplemented with the following specific substrates: chitin azure, Tween ® 20, casein, and urea for chitinase, lipase, protease, and urease activity, respectively. The hydrolytic-enzyme activity was estimated qualitatively according to the presence of a halo of clarification through hydrolase action, besides was expressed semi-quantitatively as the ratio between the hydrolytic-halo and colony diameters. The pathogenicity of the fungus was tested on adults of the aphid Rhopalosiphum padi at three temperatures of incubation (4ºC, 12ºC and 24ºC. The suspension was adjusted to a concentration of 1x10 7 conidia/ml. In pathogenicity assays at seven days post-inoculation, the fungus caused the mortality of adults of Ropalosiphum padi at different temperatures also showed a broad ability to grow on several agar-culture media, supplemented with different carbon sources at the three incubation temperatures tested. Although, the growth was greater with higher incubation temperatures (with maximum levels at 24°C, the fungus reached similar colony diameters after 15 days of incubation on the medium supplemented with Tween® 20 at the lower two incubation temperatures of 4

  12. Tierras indígenas, demarcaciones territoriales y gubernamentalización: El caso Huarpe, Pcia de Mendoza

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    Leticia Katzer

    2010-07-01

    Full Text Available El objetivo de este trabajo es analizar, a través del acercamiento a una etnografía de los procesos administrativos, la trama de dispositivos estatales que han operado en la asignación de tierras a los indígenas adscriptos como Huarpes y que operan contemporáneamente en la definición de sus derechos territoriales. Se trata de explicitar las representaciones, intereses y saberes que han guiado las propuestas de intervención, recuperándolos como componentes constitutivos de un proceso social e histórico. A diferencia de las narrativas administrativas -que mediante la adopción de un lenguaje tecnicista y de nociones como la de hábitat, terminan por naturalizar, neutralizar y deshistorizar los conflictos políticos implícitos en la construcción de territorios étnicos- enfocamos los mecanismos de intervención sobre los indígenas como una forma de territorialización, revisando críticamente la pretendida mirada neutra y objetiva del aparato administrativo-judicial, apoyada en representaciones atemporales.The objective of this work is to analyze, through approach to one ethnography of the administrative processes, the plot of state devices that have operated in the allocation of earth to the adscript indigenous like Huarpes and that operate contemporarily in the definition of their territorial rights. It is tried to specify the representations, interests and learnings that they have guided the intervention proposals, recovering them like constituent components of a social and historical process. Unlike the administrative narratives - that by means of the adoption of a technicist language and slight knowledge like the one of habitat, they finish naturalizing, neutralizing and unhistoring the conflicts implicit politicians in the construction of ethnic territories we focused the intervention mechanisms on the natives like one territorialization form, reviewing critically the tried neutral and objective glance of the administrative

  13. LA DEGRADACIÓN DE TIERRAS COMO EJE EN LA ORGANIZACIÓN DE LOS CONTENIDOS EN GEOGRAFÍA

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    María Elena Chiementon

    2008-12-01

    Full Text Available El deterioro ambiental no es un fenómeno reciente, pero la magnitud de los cambios que se observan actualmente no tiene precedentes. En este sentido, la degradación de tierras es una de las problemáticas que alcanza niveles alarmantes a escala mundial, poniéndose de manifiesto a través de una disminución significativa de la capacidad productiva del territorio. Esta problemática también está presente en la región patagónica y en particular en la Provincia de Neuquén afectando especialmente a los productores de menores recursos. Los procesos degradatorios son producto de las transformaciones que se introducen en el sistema natural, asociadas sobre todo a la aceleración de la erosión hídrica y eólica, que modifican el equilibrio y la dinámica de las relaciones entre todos sus componentes. Si bien se trata de un problema que se expresa fundamentalmente en la alteración de procesos naturales, su raíz es política, social y económica. En este marco la riqueza que ofrece este tema como eje de trabajo, propicia numerosas posibilidades en el vínculo entre el proceso de enseñanza aprendizaje con la actualidad. De esta manera se presenta como una forma diferente de trabajo áulico en la construcción de conceptos, procedimientos y valores, favoreciendo el tratamiento y la reflexión de temas tradicionales como la erosión, los circuitos productivos, etc. y aprovechando el uso cada vez más masivo de las imágenes satelitales que permiten mostrar la dimensión del problema. El presente trabajo intenta generar aportes para su abordaje conceptual y metodológico en la enseñanza de la Geografía, reconociendo la gravedad de la situación, por sus alcances a mediano y largo plazo en las distintas escalas. Analizarlo desde una perspectiva geográfica permite comprenderlo y explicarlo a partir de la articulación Sociedad-Naturaleza, organizando un amplio abanico de temas y pudiendo ser utilizado como hilo conductor en la organización de

  14. Terrestrial water fluxes dominated by transpiration: Comment

    Science.gov (United States)

    Daniel R. Schlaepfer; Brent E. Ewers; Bryan N. Shuman; David G. Williams; John M. Frank; William J. Massman; William K. Lauenroth

    2014-01-01

    The fraction of evapotranspiration (ET) attributed to plant transpiration (T) is an important source of uncertainty in terrestrial water fluxes and land surface modeling (Lawrence et al. 2007, Miralles et al. 2011). Jasechko et al. (2013) used stable oxygen and hydrogen isotope ratios from 73 large lakes to investigate the relative roles of evaporation (E) and T in ET...

  15. South African red data book - Terrestrial mammals

    CSIR Research Space (South Africa)

    Smithers, RHN

    1986-01-01

    Full Text Available Currently, 243 species of terrestrial wild mammals are known to occur in the Republic of South Africa. Using the well established IUCN definitions, 42 of these may be considered as exposed to some level of threat of extinction. Three species...

  16. Strategies for monitoring terrestrial animals and habitats

    Science.gov (United States)

    Richard Holthausen; Raymond L. Czaplewski; Don DeLorenzo; Greg Hayward; Winifred B. Kessler; Pat Manley; Kevin S. McKelvey; Douglas S. Powell; Leonard F. Ruggiero; Michael K. Schwartz; Bea Van Horne; Christina D. Vojta

    2005-01-01

    This General Technical Report (GTR) addresses monitoring strategies for terrestrial animals and habitats. It focuses on monitoring associated with National Forest Management Act planning and is intended to apply primarily to monitoring efforts that are broader than individual National Forests. Primary topics covered in the GTR are monitoring requirements; ongoing...

  17. High efficiency, long life terrestrial solar panel

    Science.gov (United States)

    Chao, T.; Khemthong, S.; Ling, R.; Olah, S.

    1977-01-01

    The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.

  18. Cepstrum Analysis of Terrestrial Impact Crater Records

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    Heon-Young Chang

    2008-06-01

    Full Text Available Study of terrestrial impact craters is important not only in the field of the solar system formation and evolution but also of the Galactic astronomy. The terrestrial impact cratering record recently has been examined, providing short- and intermediate-term periodicities, such as, Myrs, Myrs. The existence of such a periodicity has an implication in the Galactic dynamics, since the terrestrial impact cratering is usually interpreted as a result of the environmental variation during solar orbiting in the Galactic plane. The aim of this paper is to search for a long-term periodicity with a novel method since no attempt has been made so far in searching a long-term periodicity in this research field in spite of its great importance. We apply the cepstrum analysis method to the terrestrial impact cratering record for the first time. As a result of the analysis we have found noticeable peaks in the Fourier power spectrum appear ing at periods of Myrs and Myrs, which seem in a simple resonance with the revolution period of the Sun around the Galactic center. Finally we briefly discuss its implications and suggest theoretical study be pursued to explain such a long-term periodicity.

  19. Furostanol and Spirostanol Saponins from Tribulus terrestris.

    Science.gov (United States)

    Wang, Zhen-Fang; Wang, Bing-Bing; Zhao, Yang; Wang, Fang-Xu; Sun, Yan; Guo, Rui-Jie; Song, Xin-Bo; Xin, Hai-Li; Sun, Xin-Guang

    2016-03-30

    Twelve new steroidal saponins, including eleven furostanol saponins, terrestrinin J-T (1-11), and one spirostanol saponin, terrestrinin U (12), together with seven known steroidal saponins 13-19 were isolated from T. terrestris. The structures of the new compounds were established on the basis of spectroscopic data, including 1D and 2D NMR and HRESIMS, and comparisons with published data.

  20. Ethnopharmacological Studies of Tribulus Terrestris (Linn). in ...

    African Journals Online (AJOL)

    Synergism and antagonism impact of different plant metabolites present in crude fruit extract of Tribulus terrestris 'the herbal Viagra' have been studied. Variability in plant composition, biomass and metabolites concentration in different modules was significantly contributed by spatial factor. However the edhaphic ...

  1. Louisiana ESI: T_MAMMAL (Terrestrial Mammal Polygons)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for terrestrial mammals in Louisiana. Vector polygons in this data set represent terrestrial mammal...

  2. 76 FR 50274 - Terrestrial Environmental Studies for Nuclear Power Stations

    Science.gov (United States)

    2011-08-12

    ... NUCLEAR REGULATORY COMMISSION [NRC-2011-0182] Terrestrial Environmental Studies for Nuclear Power... draft regulatory guide (DG), DG-4016, ``Terrestrial Environmental Studies for Nuclear Power Stations... environmental studies and analyses supporting licensing decisions for nuclear power reactors. DATES: Submit...

  3. Terrestrial forest management plan for Palmyra Atoll

    Science.gov (United States)

    Hathaway, Stacie A.; McEachern, Kathryn; Fisher, Robert N.

    2011-01-01

    This 'Terrestrial Forest Management Plan for Palmyra Atoll' was developed by the U.S. Geological Survey (USGS) for The Nature Conservancy (TNC) Palmyra Program to refine and expand goals and objectives developed through the Conservation Action Plan process. It is one in a series of adaptive management plans designed to achieve TNC's mission toward the protection and enhancement of native wildlife and habitat. The 'Terrestrial Forest Management Plan for Palmyra Atoll' focuses on ecosystem integrity and specifically identifies and addresses issues related to assessing the status and distribution of resources, as well as the pressures acting upon them, most specifically nonnative and potentially invasive species. The plan, which presents strategies for increasing ecosystem integrity, provides a framework to implement and track the progress of conservation and restoration goals related to terrestrial resources on Palmyra Atoll. The report in its present form is intended to be an overview of what is known about historical and current forest resources; it is not an exhaustive review of all available literature relevant to forest management but an attempt to assemble as much information specific to Palmyra Atoll as possible. Palmyra Atoll is one of the Northern Line Islands in the Pacific Ocean southwest of the Hawai`ian Islands. It consists of many heavily vegetated islets arranged in a horseshoe pattern around four lagoons and surrounded by a coral reef. The terrestrial ecosystem consists of three primary native vegetation types: Pisonia grandis forest, coastal strand forest, and grassland. Among these vegetation types, the health and extent of Pisonia grandis forest is of particular concern. Overall, the three vegetation types support 25 native plant species (two of which may be extirpated), 14 species of sea birds, six shore birds, at least one native reptile, at least seven native insects, and six native land crabs. Green and hawksbill turtles forage at Palmyra Atoll

  4. Sin Tierras No Hay Paraíso: Turismo, organizaciones agrarias y apropiación territorial en México. Gustavo Marín Guardado (Coordinador. El Sauzal, Tenerife.

    Directory of Open Access Journals (Sweden)

    Maximiliano E Korstanje

    2016-08-01

    Full Text Available Sin Tierras No Hay Paraíso se sitúa como un trabajo editado por el profesor Marín Guardado que convoca 10 excelentes capítulos donde queda en evidencia esa tensión primigenia entre tierras orientadas al trabajo, y esta suerte de centros ejemplares ideológicamente orquestados para reforzar la superioridad de una clase sobre el resto de la sociedad.  En dicho proceso, y lejos de generar un crecimiento sustentable, el turismo monopoliza el uso de ciertas tierras creando serios efectos indeseados en zonas enteramente dedicadas a la agricultura. La lucha de las organizaciones agrarias en México por permanecer en las tierras que históricamente les pertenecían es inversamente proporcional a la voracidad empresaria del capitalismo moderno. Una de las grandes falencias de los estudios turísticos consiste en la sobrevaloración del turismo como un organizador social y geográfico, ciertamente con fallas que deben ser corregidas pero trivializando los alcances de los estudios postmarxistas los cuales han denunciado como los procesos de re-territorialización esconden una lógica de la “expropiación” y/o transferencia de riqueza.

  5. ALGUNAS CONSIDERACIONES GENERALES EN TORNO A LA DINÁMICA AGRARIA Y A LA POLÍTICA DE TENENCIA DE TIERRAS, EN EL PERÍODO 1974-1984.

    Directory of Open Access Journals (Sweden)

    José Daniel Cazanga

    2012-11-01

    Full Text Available Acorde con los objetivos y actividades· de discusión y reflexión auspiciado por este seminario, la presente comunicación pretende proporcionar un marco referencial con las coordenadas teóricas e históricas básicas para comprender la dinámica experimentada por el sector agrario, así como el comportamiento estatal en estos últimos años, respecto del acceso y utilización de las tierras agrícolas. En primer lugar, se entregan algunos antecedentes en torno a la naturaleza de las transformaciones y modernización experimentadas en el agro costarricense desde 1950 hasta fines de los años setenta. Se establece, además, un panorama contextual general para situar el carácter y significación de las políticas de tierras desplegadas en el período 1974-1984. En particular se hace una breve caracterización del sector agropecuario por medio del examen de algunas variables significativas, como es la producción, el empleo, las condiciones de vida, la distribución de la tierra, etc. Finalmente se concluye estableciendo algunos rasgos fundamentales que contribuyen a perfilar el carácter y alcances de la política de tierras desplegada en el período.

  6. Space and Terrestrial Photovoltaics: Synergy and Diversity

    Science.gov (United States)

    Bailey, Sheila; Raffaelle, Ryne; Emery, Keith

    2002-01-01

    A historical view of the research and development in photovoltaics from the perspective of both the terrestrial and the space communities is presented from the early days through the '70s and '80s and the '90s and beyond. The synergy of both communities in the beginning and once again in the present and hopefully future are highlighted, with examples of the important features in each program. The space community which was impressed by the light-weight and reliability of photovoltaics drove much of the early development. Even up to today, nearly every satellites and other scientific space probe that has been launched has included some solar power. However, since the cost of these power systems were only a small fraction of the satellite and launch cost, the use of much of this technology for the terrestrial marketplace was not feasible. It was clear that the focus of the terrestrial community would be best served by reducing costs. This would include addressing a variety of manufacturing issues and raising the rate of production. Success in these programs and a resulting globalization of effort resulted in major strides in the reduction of PV module costs and increased production. Although, the space community derived benefit from some of these advancements, its focus was on pushing the envelope with regard to cell efficiency. The gap between theoretical efficiencies and experimental efficiencies for silicon, gallium arsenide and indium phosphide became almost non-existent. Recent work by both communities have focused on the development thin film cells of amorphous silicon, CuInSe2 and CdTe. These cells hold the promise of lower costs for the terrestrial community as well as possible flexible substrates, better radiation resistance, and higher specific power for the space community. It is predicted that future trends in both communities will be directed toward advances through the application of nanotechnology. A picture is emerging in which the space and

  7. Linkages between terrestrial ecosystems and the atmosphere

    Science.gov (United States)

    Bretherton, Francis; Dickinson, Robert E.; Fung, Inez; Moore, Berrien, III; Prather, Michael; Running, Steven W.; Tiessen, Holm

    1992-01-01

    The primary research issue in understanding the role of terrestrial ecosystems in global change is analyzing the coupling between processes with vastly differing rates of change, from photosynthesis to community change. Representing this coupling in models is the central challenge to modeling the terrestrial biosphere as part of the earth system. Terrestrial ecosystems participate in climate and in the biogeochemical cycles on several temporal scales. Some of the carbon fixed by photosynthesis is incorporated into plant tissue and is delayed from returning to the atmosphere until it is oxidized by decomposition or fire. This slower (i.e., days to months) carbon loop through the terrestrial component of the carbon cycle, which is matched by cycles of nutrients required by plants and decomposers, affects the increasing trend in atmospheric CO2 concentration and imposes a seasonal cycle on that trend. Moreover, this cycle includes key controls over biogenic trace gas production. The structure of terrestrial ecosystems, which responds on even longer time scales (annual to century), is the integrated response to the biogeochemical and environmental constraints that develop over the intermediate time scale. The loop is closed back to the climate system since it is the structure of ecosystems, including species composition, that sets the terrestrial boundary condition in the climate system through modification of surface roughness, albedo, and, to a great extent, latent heat exchange. These separate temporal scales contain explicit feedback loops which may modify ecosystem dynamics and linkages between ecosystems and the atmosphere. The long-term change in climate, resulting from increased atmospheric concentrations of greenhouse gases (e.g., CO2, CH4, and nitrous oxide (N2O)) will further modify the global environment and potentially induce further ecosystem change. Modeling these interactions requires coupling successional models to biogeochemical models to

  8. Especiación de tierras raras en las soluciones ácidas y neutras del sistema de drenaje del Arroyo del Val (Zaragoza

    Directory of Open Access Journals (Sweden)

    Zamora, A.

    1994-08-01

    -90 % of LREE and for 100 % of HREE. LnPO04 and Ln(PO43-2 complexes are quite significant compared to carbonate complexes, mainly in the speciation of HREE. These results il1ustrate the importance of phosphate ion concentration and REE phosphate complexation reactions in REEs speciation calculations.Las soluciones de la cuenca de drenaje del Arroyo del Val (Zaragoza presentan unas características geoquímicas muy diferenciadas, lo que las hace especialmente apropiadas para el estudio de diferentes aspectos acerca del comportamiento de los elementos de las Tierras Raras. Esta cuenca está constituida por un curso principal (Arroyo del Val de aguas ácidas (con valores de pH entre 3 y 4.5 e importantes concentraciones de sulfato, Al, Fe y distintos metales pesados al que desaguan varios afluentes de aguas bicarbonatadas (sulfatadas cálcicas (con valores de pH de hasta 7.5, alcalinidad apreciable y notables concentraciones de fosfato. En los puntos de confluencia del Arroyo del Val con los afluentes se producen espectaculares procesos de floculación de coloides ricos en aluminio, hierro y sulfato que tapizan el fondo del curso principal. Los elementos de las Tierras Raras fueron analizados en distintas muestras de aguas ácidas tomadas a lo largo de la cabecera del Arroyo del Val y en dos muestras de aguas neutras correspondientes a dos de los afluentes del sistema. Las concentraciones de estos elementos determinadas en las soluciones ácidas son, cuando menos, dos órdenes de magnitud superiores a las de las soluciones neutras y sus pautas de distribución (normalizadas frente a NASC muestran un marcado enriquecimiento en las Tierras Raras Intermedias (IREE; Eu-Tb. Los cálculos de especiación de REE realizados en las aguas ácidas muestran que estos elementos se encuentran de forma dominante como especies iónicas libres (Ln3+ ≈ 35 % y especialmente formando complejos con sulfato (LnSO+4 ≈ 60% y en menor proporción como Ln(SO4-2 ≈ 5%. Estos porcentajes

  9. Dustbathing and intra-sexual communication of social degus, Octodon degus (Rodentia:Octodontidae Baños de tierra y comunicación intra-sexual en el degu social, Octodon degus (Rodentia: Octodontidae

    Directory of Open Access Journals (Sweden)

    LUIS A. EBENSPERGER

    2000-06-01

    Full Text Available I observed the behavior of captive male and female Octodon degus to assess if dustbathing behavior plays a role in social communication among unfamiliar, same-sex conspecifics. Degus of a first group (control responders were individually exposed during 10-min tests to an arena containing loose, clean soil. I compared the latency to first dustbathing as well as the overall frequency of dustbathing events recorded to control responders with the corresponding figures recorded to a second group of degus (experimental responders after they were individually introduced into the same arena but with soil previously used for dustbathing by a same-sex conspecific (depositor. I also compared the location of dustbathing events by experimental responders with that of depositor individuals. Although male degus tended to exhibit shorter latencies to first dustbathing event when in clean soil, this variable was not significantly influenced by sex of responders or the type of soil (clean or used. In contrast, a significant interaction between both factors revealed that males dustbathe at a higher rate than females when on clean soil, but similarly so when in a substratum previously dustbathed by a same-sex conspecific. The place chosen by both male and female responders to conduct their dustbathing behavior was unrelated to the presence of previous marks left by a depositor degu. I conclude that dustbathing is involved in communication during male-male, but not during female-female, interactions in the degu. I suggest that such male-male interactions represent competition for matesObservé el comportamiento de machos y hembras en cautiverio del roedor social Octodon degus para evaluar si la conducta de bañarse en tierra es parte de un mecanismo de comunicación social entre conespecíficos del mismo sexo, desconocidos entre sí. Un primer grupo de degus (respondientes controles fueron introducidos individualmente durante ensayos de 10 min a un terrario con

  10. Application of Terrestrial Environments in Orion Assessments

    Science.gov (United States)

    Barbre, Robert E.

    2016-01-01

    This presentation summarizes the Marshall Space Flight Center Natural Environments Terrestrial and Planetary Environments (TPE) Team support to the NASA Orion space vehicle. The TPE utilizes meteorological data to assess the sensitivities of the vehicle due to the terrestrial environment. The Orion vehicle, part of the Multi-Purpose Crew Vehicle Program, is designed to carry astronauts beyond low-earth orbit and is currently undergoing a series of tests including Exploration Test Flight (EFT) - 1. The presentation describes examples of TPE support for vehicle design and several tests, as well as support for EFT-1 and planning for upcoming Exploration Missions while emphasizing the importance of accounting for the natural environment's impact to the vehicle early in the vehicle's program.

  11. Evolution of Herbivory in Terrestrial Vertebrates

    Science.gov (United States)

    Sues, Hans-Dieter

    2000-08-01

    Although herbivory probably first appeared over 300 million years ago, it only became established as a common feeding strategy during Late Permian times. Subsequently, herbivory evolved in numerous lineages of terrestrial vertebrates, and the acquisition of this mode of feeding was frequently associated with considerable evolutionary diversification in those lineages. This book represents a comprehensive overview of the evolution of herbivory in land-dwelling amniote tetrapods in recent years. In Evolution of Herbivory in Terrestrial Vertebrates, leading experts review the evolutionary history and structural adaptations required for feeding on plants in the major groups of land-dwelling vertebrates, especially dinosaurs and ungulate mammals. As such, this volume will be the definitive reference source on this topic for evolutionary biologists and vertebrate paleontologists.

  12. The overlooked terrestrial impacts of mountaintop mining

    Science.gov (United States)

    Wickham, James; Wood, Petra Bohall; Nicholson, Matthew C.; Jenkins, William; Druckenbrod, Daniel; Suter, Glenn W.; Strager, Michael P.; Mazzarella, Christine; Galloway, Walter; Amos, John

    2013-01-01

    Ecological research on mountaintop mining has been focused on aquatic impacts because the overburden (i.e., the mountaintop) is disposed of in nearby valleys, which leads to a wide range of water-quality impacts on streams. There are also numerous impacts on the terrestrial environment from mountaintop mining that have been largely overlooked, even though they are no less wide ranging, severe, and multifaceted. We review the impacts of mountaintop mining on the terrestrial environment by exploring six broad themes: (1) the loss of topographic complexity, (2) forest loss and fragmentation, (3) forest succession and soil loss, (4) forest loss and carbon sequestration, (5) biodiversity, and (6) human health and well-being.

  13. Del discurso poblador a la praxis latifundista: la distribución de la tierra pública en la Patagonia

    Directory of Open Access Journals (Sweden)

    Susana Bandieri

    2005-01-01

    Full Text Available One of the main task get done by the national State consolidatted in 1880 was to continue with the previous governments' practice of applying a systematic policy of transffering public lands to private hands through donation, selling or reward for services to the Nation. The concentration of the land in few hands and the expanssion of the great proprierties were the most known consequences of these policies, incremented with the expanssion of the internal borders through occupational military campaigns on the indigenous space. In this work it is studied the characteristics of the great landowners' accumulation process, throghout land-buyings to the State during the border's expansion process that got rid of the pre-existent society and consolidatted the great landowners' proprierties without giving place to massive process of half and little rural landowners sector, nor effective poblational center on the new borders, as the official discourse seemed to suggest.Una de las tareas fundamentales cumplidas por el Estado nacional consolidado a partir de 1880 fue la de continuar con las prácticas de los anteriores gobiernos de aplicar una política sistemática de transferencia de tierras públicas a manos privadas a través de la donación, la venta o la recompensa por servicios prestados a la Nación. La concentración de la tierra en pocas manos y la expansión de las grandes propiedades fueron las consecuencias más conocidas de estas políticas, incrementadas a partir del avance de las fronteras internas por las campañas militares de ocupación de los espacios indígenas. En este trabajo se estudian las características del proceso de acumulación terrateniente en la Patagonia, mediante compras de tierras al Estado durante el proceso de expansión de las fronteras que desalojó a la sociedad preexistente y consolidó la propiedad terrateniente sin generar un proceso masivo de aparición de sectores de medianos y pequeños propietarios rurales

  14. MAFF monitoring of the terrestrial environment

    International Nuclear Information System (INIS)

    Sherlock, J.C.

    1993-01-01

    This paper addresses the food surveillance programme of the Ministry of Agriculture, Fisheries and Food (MAFF), in particular the Terrestrial Radioactivity Monitoring Programme (TRAMP) and the estimation of dietary intake of radionuclides. To define the surveillance programme the following issues need to be decided upon: 1) the type of food which should be analysed; 2) the nature of the contaminants which should be analysed; and 3) the geographical location from which the food samples should be taken. (author)

  15. Astrophysical and terrestrial neutrinos in Supernova detectors

    International Nuclear Information System (INIS)

    Lagage, P.O.

    1985-09-01

    Supernova (SN) explosions are the place of very fundamental phenomena, whose privileged messengers are neutrinos. But such events are very rare. Then, SN detection has to be combined with other purposes. The recent developments of SN detectors have been associated with developments of underground particle physics (proton decay, monopoles ...). But here, I will restrict myself to discuss the possibilities for a supernova detector to be sensitive to other sources of neutrinos, astrophysical or terrestrial

  16. Documentation of Bridges by Terrestrial Laser Scanner

    OpenAIRE

    Truong-Hong, Linh; Laefer, Debra F.

    2015-01-01

    Bridge structures are subjected to deterioration due to excessive usage, overloading, and aging material. For the last two decades, a significant amount research has been developed for collecting data for structural health monitoring. Yet, visual investigation with an on-site inspector remains the predominant method. This is true despite the highly subjective and time consuming aspects of this approach. Alternatively, terrestrial laser scanning can acquire surface details of structures quickl...

  17. Interferometer Designs for the Terrestrial Planet Finder

    Science.gov (United States)

    Lawson, P. R.; Dumont, P. J.; Colavita, M. M.

    2000-01-01

    The Terrestrial Planet Finder (TPF) is a space-based infrared interferometer that will combine high sensitivity and spatial resolution to detect and characterize planetary systems within 15 pc of our sun. TPF is a key element in NASA's Origins Program and is currently un- der study in its Pre-Project Phase. We review some of the interferometer designs that have been considered for starlight nulling, with particular attention to the architecture and subsystems of the central beam-combiner.

  18. Global change and terrestrial hydrology - A review

    Science.gov (United States)

    Dickinson, Robert E.

    1991-01-01

    This paper reviews the role of terrestrial hydrology in determining the coupling between the surface and atmosphere. Present experience with interactive numerical simulation is discussed and approaches to the inclusion of land hydrology in global climate models ae considered. At present, a wide range of answers as to expected changes in surface hydrology is given by nominally similar models. Studies of the effects of tropical deforestation and global warming illustrate this point.

  19. Furostanol and Spirostanol Saponins from Tribulus terrestris

    Directory of Open Access Journals (Sweden)

    Zhen-Fang Wang

    2016-03-01

    Full Text Available Twelve new steroidal saponins, including eleven furostanol saponins, terrestrinin J–T (1–11, and one spirostanol saponin, terrestrinin U (12, together with seven known steroidal saponins 13–19 were isolated from T. terrestris. The structures of the new compounds were established on the basis of spectroscopic data, including 1D and 2D NMR and HRESIMS, and comparisons with published data.

  20. ESTRUCTURA POBLACIONAL DE LA PALMA IRIARTEA DELTOIDEA, EN UN BOSQUE DE TIERRA FIRME DE LA AMAZONIA COLOMBIANA

    Directory of Open Access Journals (Sweden)

    Gonzalez Roy

    2012-06-01

    Full Text Available El objetivo de esta investigación fue caracterizar la densidad y la estructura poblacional de la palma bombona Iriartea deltoidea en un bosque de tierra firme de la zona sur del Parque Nacional Natural Amacayacu, en la Amazonia Colombiana. En seis parcelas de 1 ha y 90 transectos de 50 x 1 m, se censaron todos los individuos de la especie. Para cada individuo, se registró la altura del tallo, el estado morfológico de las hojas (i.e. hojas enteras, hojas divididas, forma de las pinnas, la formación de raíz fúlcrea, la altura del cono de la raíz y el estado fenol��gico (brácteas, inflorescencias e infrutescencias. Se encontraron 2819 individuos (376±58 ind/ha que se agruparon en tres grandes categorías de edad significativamente diferentes (e.g. plántulas, juveniles y adultos. La gran categoría Plántulas se caracterizó por individuos con hojas no divididas, sin formación de raíces fúlcreas y comprendió el 96.6% de los individuos muestreados. Esta se subdividió en seis categorías de plántulas estadísticamente significativas dadas por cambios en la altura, número y morfología de las hojas. La gran categoría Juvenil consistió en individuos con hojas divididas en pinnas, formación de raíces fúlcreas con altura de cono radicular menor a 1 m, sin estructuras reproductivas y con 1.5% (42 de los individuos totales. Esta se subdividió en dos categorías de juveniles (I y II. La categoría Adultos incluyó todos los individuos con hojas divididas en pinnas, formación de raíces fúlcreas con altura del cono radicular mayor a 1 m y con presencia de estructuras reproductivas. Estos correspondieron al 1.9% (54 de los individuos y se subdividieron en dos categorías: Adultos I y Adultos II, dadas principalmente por diferencias significativas en la altura. La densidad de la población presentó una distribución típica de poblaciones naturales de plantas tropicales, siguiendo un modelo de Poisson en donde abundan individuos de

  1. Evaluación de la degradación de tierras a nivel nacional. Herramienta metodológica de soporte a la integración y ampliación del manejo sostenible de tierras y al apoyo a la toma de decisiones.

    OpenAIRE

    de la Colina Rodriguez, Armando Jesus; Luis Machin, Angel

    2017-01-01

    La degradación y el manejo sostenible de tierras son un desafío ambiental priorizado a nivel global que converge y hace sinergia con las tres Convenciones de Río. Problema identificado y abordado en las metas al 2020 de Aichi y en la Agenda Global 2030 de Desarrollo Sostenible. Sin embargo la efectividad de herramientas y metodologías que apoyen a tomadores de decisiones y grupos multidisciplinarios a trabajar de forma conjunta en su implementación y despliegue a nivel global, regional, naci...

  2. Hydrolytic microbial communities in terrestrial ecosystems

    Science.gov (United States)

    Manucharova, Natalia; Chernov, Timofey; Kolcova, Ekaterina; Zelezova, Alena; Lukacheva, Euhenia; Zenova, Galina

    2014-05-01

    Hydrolytic microbial communities in terrestrial ecosystems Manucharova N.A., Chernov T.I., Kolcova E.M., Zelezova A.D., Lukacheva E.G. Lomonosov Moscow State University, Russia Vertical differentiation of terrestrial biogeocenoses is conditioned by the formation of vertical tiers that differ considerably in the composition and structure of microbial communities. All the three tiers, phylloplane, litter and soil, are united by a single flow of organic matter, and are spatially separated successional stages of decomposition of organic substances. Decomposition of organic matter is mainly due to the activity of microorganisms producing enzymes - hydrolase and lyase - which destroy complex organic compounds. Application of molecular biological techniques (FISH) in environmental studies provides a more complete information concerning the taxonomic diversity and potential hydrolytic activity of microbial complexes of terrestrial ecosystems that exist in a wide range of environmental factors (moisture, temperature, redox potential, organic matter). The combination of two molecular biological techniques (FISH and DGGE-analysis of fragments of gene 16S rRNA total amplificate) enables an informative assessment of the differences in the structure of dominant and minor components of hydrolytic complexes formed in different tiers of terrestrial ecosystems. The functional activity of hydrolytic microbial complexes of terrestrial ecosystems is determined by the activity of dominant and minor components, which also have a high gross enzymatic activity. Degradation of biopolymers in the phylloplane is mainly due to the representatives of the Proteobacteria phylogenetic group (classes alpha and beta). In mineral soil horizons, the role of hydrolytic representatives of Firmicutes and Actinobacteria increases. Among the key environmental parameters that determine the functional activity of the hydrolytic (chitinolytic) complex of soil layer (moisture, nutrient supply, successional

  3. Localización de hipocentros y determinación de su magnitud en Tierra del Fuego y zonas aledañas

    Directory of Open Access Journals (Sweden)

    Carolina Buffoni

    2009-12-01

    Full Text Available Nuevos hipocentros de sismos de baja a mediana magnitud han sido calculados con el fin de estudiar la sismicidad en la Isla de Tierra del Fuego y zonas aledañas. La región presenta un complejo escenario tectónico: la isla es atravesada por una falla transformante conocida como Falla de Magallanes-Fagnano la cual divide a Tierra del Fuego en dos bloques continentales. Esta falla constituye el mayor segmento continental del borde de las placas de Scotia y Sudamericana. La isla tiene una importante historia sismológica que incluye un evento de carácter destructivo ocurrido en diciembre de 1949 el cual alcanzó una magnitud de 7.8 en la escala de Richter. De un análisis de sismicidad histórica, se conocen reportes de sismos en los años 1929, 1930, 1944, 1949 y 1970. En el presente trabajo se ha realizado la localización de los hipocentros y el análisis de los errores en la determinación. A tal efecto se analizaron los registros de 5 estaciones sismológicas para el período enero 2007 - diciembre 2007. Más de 180 sismos fueron localizados y algunos de ellos comparados con los cinco eventos registrados por el NEIC (National Earthquake Information Center y el ISC (Internacional Seismological Centre para el mismo período. El cálculo de magnitud fue realizado a partir de la amplitud del primer arribo. La mayoría de los sismos tienen un valor de magnitud mb que se concentra entre 2 y 4 grados. Con respecto a la profundidad hipocentral, más del 50% de los eventos localizados tienen profundidades en los primeros 10 km. El mapa de sismicidad obtenido muestra una distribución de sismos sobre y en las cercanías de la falla Magallanes-Fagnano, una concentración de epicentros en el área de la Cordillera de Darwin y en los alrededores de la placa de Scotia, manifestando indicios de una correlación con el ambiente geotectónico del área de estudio.New hypocentre locations of earthquakes with low to medium magnitude have been calculated in

  4. Las ciencias de la tierra y la biblia. Una aproximación desde la razón científica

    OpenAIRE

    Francisco J. Ayala

    2004-01-01

    El desarrollo de la Ciencia, Natural e Histórica, ha ido aportando nuevos elementos que permiten una aproximación a los relatos bíblicos desde la perspectiva de la razón científica. En este sentido, se presenta una aproximación científica, básicamente desde las Ciencias de la Tierra y teniendo en cuenta la realidad histórica del pueblo hebreo y la propia Biblia, al relato de la Creación, y los posibles núcleos histórico-científicos de los relatos del Diluvio Universal y la dest...

  5. Las ciencias de la tierra y la Biblia. Una aproximación desde la razón científica

    OpenAIRE

    Ayala-Carcedo, Francisco Javier

    2004-01-01

    El desarrollo de la Ciencia, Natural e Histórica, ha ido aportando nuevos elementos que permiten una aproximación a los relatos bíblicos desde la perspectiva de la razón científica. En este sentido, se presenta una aproximación científica, básicamente desde las Ciencias de la Tierra y teniendo en cuenta la realidad histórica del pueblo hebreo y la propia Biblia, al relato de la Creación, y los posibles núcleos histórico-científicos de los relatos del Diluvio Universal y la destrucció...

  6. CONFLICTOS DE INTERESES EN LA ORDENACIÓN DE UN TERRITORIO DE MONTAÑA: EL TURISMO RURAL EN LA TIERRA PINARIEGA SORIANA

    Directory of Open Access Journals (Sweden)

    Jesús María Bachiller Martínez

    2012-01-01

    Full Text Available El auge del uso público en los espacios rurales es un componente más de las crecientes relaciones campo-ciudad. Los conflictos se multiplican, no solo en la relación entre desarrollo turístico y conservación, sino también en el trato con los propietarios rústicos, públicos y privados, que tienden a organizarse y plantear sus reivindicaciones en la ordenación y gestión de los territorios implicados. Se expone, como ejemplo, un propietario de excepción, la Mancomunidad de los 150 pueblos de la Tierra de Soria/ayuntamiento de Soria, que ha tenido que hacer frente al cambio de función que ha supuesto el aumento del uso público en sus montes.

  7. Study of the thermal behaviour of traditional wine cellars: the case of the area of ''Tierras Sorianas del Cid'' (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero, I.C.; Ocana, S.M. [Universidad Politecnica de Madrid (Spain). Dpto. de Construccion y Vias Rurales

    2005-01-01

    This article studies the hygro-thermal behaviour of two traditional underground wine cellars from Morcuera (Soria, Spain). The differences between them are analyzed and our hypothesis is that one of these constructions is better than the other for the ageing of wines. The hypothesis takes into consideration the existence of a temperature difference of over 20{sup o}C between them as a basis for reaching the aforementioned conclusion. However, the relative humidity inside both of them is 100%, which could pose problems if the presence of mould is not controlled. This study is based on fieldwork for the inventory and cataloguing of traditional agrarian constructions in the ''Tierras Sorianas'' area. The objective of this investigation is to highlight some advantages of traditional building techniques over modern construction practices from the energy-saving viewpoint. (author)

  8. Entre la Jatropha y la pobreza: reflexiones sobre la producción de agrocombustibles en tierras de temporal en Yucatán

    Directory of Open Access Journals (Sweden)

    Armando Rucoba García

    2013-01-01

    Full Text Available Se analizan las relaciones dominantes del mercado que impulsan los agrocombustibles en tierras agrícolas de baja productividad en el estado de Yucatán. Según el estudio, el rendimiento de Jatropha curcas es variable en función de las condiciones ambientales y sociotécnicas de los agroecosistemas. En función de los principios agroecológicos, la asociación de piñón a otros cultivos puede ser una alternativa de aprovechamiento local y recomendable su establecimiento mientras no compita con la agricultura de subsistencia para no agravar la escasez de alimentos en el medio rural. Desde la perspectiva ecológica, no se recomienda mantener el monocultivo en el largo plazo a pesar de su alta rentabilidad.

  9. En una tierra inmensa y sin clérigos. La fundación del seminario del Tucumán, 1587-1611

    Directory of Open Access Journals (Sweden)

    Leticia Pérez Puente

    2016-01-01

    Full Text Available En este trabajo se estudia la creación del seminario conciliar de la diócesis del Tucumán. Un colegio muy distinto a los ordenados en el concilio de Trento, tanto por sus características, como porque su fundación formal tuvo por objetivo que la Compañía de Jesús se arraigara en el territorio tucumano y se hiciera cargo de la evangelización. Se trata de un ejemplo de cómo los mandatos del Concilio de Trento debieron modificarse al implantarse en Indias, pues, al igual que cualquier otra norma, los decretos canónicos tuvieron que adaptarse para responder a las necesidades de cada una de las diócesis, a las características de la tierra y a la forma en que en ella se organizaban los poderes.

  10. Propiedades magnéticas y micromorfología de suelos en el sitio arqueológico Marazzi 2, Isla Grande de Tierra del Fuego, Chile

    OpenAIRE

    Ozán, Ivana Laura; Orgeira, Maria Julia

    2017-01-01

    El objetivo del presente trabajo es investigar el origen de la señal magnética (natural y/o antrópica) y su vinculación con la micromorfología de suelos, en dos perfiles del sitio arqueológico Marazzi 2, perteneciente al Holoceno tardío y ubicado en el noroeste de la Isla Grande de Tierra del Fuego (Chile). Los resultados muestran que el perfil P1 presenta un pico de la señal magnética (presencia de magnetita y/o titanomagnetita) entre los 30 - 70 cm, que coincide con un horizonte Ab y ABb en...

  11. Influencia de informalidad en titulación de tierras y planificación productiva, en cadenas agroexportadoras del Valle del Mantaro, Perú

    Directory of Open Access Journals (Sweden)

    William Rodríguez Giráldez

    2015-06-01

    Full Text Available El objetivo fue determinar la influencia de la informalidad en la titulación de tierras sobre la planificación productiva en cadenas agroexportadoras del Valle del Mantaro. Investigación de alcance descriptivo-correlacional, no experimental, transeccional. Fueron encuestados 383 productores agrícolas de las provincias que comprenden el Valle del Mantaro: Huancayo, Concepción, Jauja y Chupaca. Se utilizaron estadísticos descriptivos como, distribución de frecuencias, tablas de contingencia, y ji al cuadrado para prueba de hipótesis. Entre los resultados se tiene que, 1 En informalidad en titulación de tierras, 61 % de productores tienen título de propiedad y 2 % en trámite; 95,7 % saben de beneficios del título de propiedad; 55 % manifiestan que terrenos son de su propiedad; 45 % consideran que parte de sus terrenos los alquilan; 2 En planificación productiva, 52 % de productores deciden qué sembrar en función a la demanda y mejor precio de mercado, 62 % mejoraron resultados gracias a la planificación, 23 % lograron metas de producción entre el 75 % y 100 %, solo 19 % mejoraron su productividad esperada y 47 % mejoraron rangos inferiores a 25 %; además el 87 % consideran que en la planificación de la producción deben participar productores y empresas. En conclusión, participar en cadenas productivas no depende de la tenencia de terrenos con título de propiedad. El trabajo asociativo no depende de la decisión de sembrar, de la planificación, de mejoras de productividad, ni de participación en procesos de planificación.

  12. Tierra, palma africana y conflicto armado en el Bajo Atrato chocoano, Colombia. Una lectura desde el cambio en los órdenes de extracción

    Directory of Open Access Journals (Sweden)

    Paola García Reyes

    2014-01-01

    Full Text Available Desde la década de 1990 la región del Pacífico colombiano vive un proceso inédito de agudización del conflicto armado interno. Algunos estudios han descrito este hecho como una consecuencia no intencionada del reconocimiento de las poblaciones negras de la región como grupos étnicos propietarios de los territorios en los que habitan. En este artículo me pregunto de qué forma resultaron modificadas las dinámicas de conflicto en la subregión del Bajo Atrato chocoano (1985-2005 en Colombia, si esto se vincula con la explotación de sus recursos naturales, en particular la palma de aceite y cuál fue el papel que jugó en estas dinámicas el cambio en el régimen de propiedad de la tierra. Para responder a estas preguntas me baso en los estudios sobre la economía política de los conflictos armados e introduzco el concepto de órdenes de extracción con el fin de analizar las acciones de los actores del conflicto, los empresarios de la palma, el Estado como agente regulador y las poblaciones negras. Mi conclusión principal es que el cambio en la estructura de propiedad de la tierra no fue causa del conflicto y que el tipo de actor involucrado es una variable relevante.

  13. Methodology for evaluating the grounding system in electrical substations; Metodologia para la evaluacion del sistema de puesta a tierra en subestaciones electricas

    Energy Technology Data Exchange (ETDEWEB)

    Torrelles Rivas, L.F [Universidad Nacional Experimental Politecnica: Antonio Jose de Sucre (UNEXPO), Guayana, Bolivar (Venezuela)]. E-mail: torrellesluis@gmail.com; Alvarez, P. [Petroleos de Venezuela S.A (PDVSA), Maturin, Monagas (Venezuela)]. E-mail: alvarezph@pdvsa.com

    2013-03-15

    The present work proposes a methodology for evaluating grounding systems in electrical substations from medium and high voltage, in order to diagnose the state of the elements of the grounding system and the corresponding electrical variables. The assessment methodology developed includes a visual inspection phase to the elements of the substation. Then, by performing measurements and data analysis, the electrical continuity between the components of the substation and the mesh ground is verified, the soil resistivity and resistance of the mesh. Also included in the methodology the calculation of the step and touch voltage of the substation, based on the criteria of the International IEEE standards. We study the case of the 115 kV Pirital Substation belonging to PDVSA Oriente Transmission Network. [Spanish] En el presente trabajo se plantea una metodologia para la evaluacion de sistemas de puesta a tierra en subestaciones electricas de media y alta tension, con la finalidad de diagnosticar el estado de los elementos que conforman dicho sistema y las variables electricas correspondientes. La metodologia de evaluacion desarrollada incluye una fase de inspeccion visual de los elementos que conforman la subestacion. Luego, mediante la ejecucion de mediciones y analisis de datos, se verifica la continuidad electrica entre los componentes de la subestacion y la malla de puesta a tierra, la resistividad del suelo y resistencia de la malla. Se incluye tambien en la metodologia el calculo de las tensiones de paso y de toque de la subestacion, segun lo fundamentado en los criterios de los estandares Internacionales IEEE. Se estudia el caso de la Subestacion Pirital 115 kV perteneciente a la Red de Transmision de PDVSA Oriente.

  14. Teppeki, selective insecticide about Bombus terrestris.

    Science.gov (United States)

    Fanigliulo, Angela; Filì, Vittorio; Pacella, Rosa; Comes, Soccorsa; Crescenzi, Aniello

    2009-01-01

    At a time when a highly controversial debate about the causes of the widespread deaths of bees is taking place all over Europe, which accused the agriculture and its practices with particular reference to the harmful effects of some insecticides, it seems important to point out as another insecticide, the Teppeki, can be selective about bumble and have a good compatibility with the activity of the apiaries. This insecticide has the active ingredient flonicamid (500 g/kg) belonging to a new chemical class, called pyridinecarboxamides: the product works systemic and is known as having a long lasting efficacy against all important aphid species. Bioagritest test facility of Pignola (PZ, Italy) has conducted in two successive production cycles an experimental trial on a tomato hydroponic cultivation within the Agricola Bonsai farm in Sibari (CS, Italy), whose objective was to measure the selectivity of flonicamid on Bombus terrestris, insects playing an important role in the pollination of certain species grown in greenhouse such as Tomato, Eggplant, Pepper and Cucumber. On the pollinated flower B. terrestris leaves some trace of its visit, a typical dark trademark: on the detection of the marking of flowers was based the testing program conducted by Bioagritest. Two thesis were compared: A, standard) treatment with a foliar insecticide, the neonicotinoide acetamiprid, normally used for control of aphids and whiteflies (unlike other neonicotinoides--imidacloprid and thiametoxam--quite selective about B. terrestris) and B, Teppeki) foliar treatment with Teppeki, to the maximum dose indicated on the label. The experimental design included the use of randomized blocks with 4 repetitions (4 plots/thesis with 100 plants each). In every thesis six B. terrestris hives were placed 2 days before treatment: the respective holes remained closed during the treatment and the 12 following hours. In order to verify the pollination, by the detection of the flower marking, 2 flowers

  15. VARIABILIDAD ESPACIAL E INTENSIDAD DE OCUPACIÓN EN SITIOS CAZADORES-RECOLECTORES DE LA COSTA ATLÁNTICA DE TIERRA DEL FUEGO (ARGENTINA (Spatial Variability and Occupation Intensity in Hunter-Gatherer Sites from the Atlantic Coast of Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Joan Negre

    2016-12-01

    Full Text Available Este trabajo explora la variabilidad espacial del registro arqueológico en asentamientos cazadores-recolectores del litoral atlántico de Tierra del Fuego (Argentina, mediante el desarrollo teórico y metodológico de un conjunto de herramientas de carácter cuantitativo. El objetivo es evaluar la intensidad de ocupación a partir de tres casos de estudio, mediante la aplicación de distintos enfoques provenientes de la estadística espacial, el análisis de la diversidad del registro arqueológico y el estudio de rastros de uso en artefactos líticos. Los resultados de esta propuesta han permitido relacionar el grado de complejidad entre la organización social del espacio, la variabilidad del registro material y los niveles de intensidad de ocupación. ENGLISH: This work focuses on the spatial variability of the archaeological record at hunter-gatherer sites on the Atlantic coast of Tierra del Fuego, Argentina. The theoretical and methodological approach was developed using a quantitative toolset. The main goal is to evaluate occupation intensity based on three case studies and using three different approaches: spatial statistics, archaeological record diversity, and use-wear analysis. The results show relationships among the respective levels of complexity seen in the social organization of space, material record variability, and occupation intensity.

  16. Evolution of ore deposits on terrestrial planets

    Science.gov (United States)

    Burns, R. G.

    1991-01-01

    Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Core formation removed most of the siderophilic and chalcophilic elements, leaving mantles depleted in many of the strategic and noble metals relative to their chondritic abundances. Basaltic magma derived from partial melting of the mantle transported to the surface several metals contained in immiscible silicate and sulfide melts. Magmatic ore deposits were formed during cooling, fractional crystallization and density stratification from the basaltic melts. Such ore deposits found in earth's Archean rocks were probably generated during early histories of all terrestrial planets and may be the only types of igneous ores on Mars. Where plate tectonic activity was prevalent on a terrestrial planet, temporal evolution of ore deposits took place. Repetitive episodes of subduction modified the chemical compositions of the crust and upper mantles, leading to porphyry copper and molybdenum ores in calc-alkaline igneous rocks and granite-hosted tin and tungsten deposits. Such plate tectonic-induced mineralization in relatively young igneous rocks on earth may also have produced hydrothermal ore deposits on Venus in addition to the massive sulfide and cumulate chromite ores associated with Venusian mafic igneous rock. Sedimentary ore deposits resulting from mechanical and chemical weathering in reducing atmospheres in Archean earth included placer deposits (e.g., uraninite, gold, pyrite ores). Chromite, ilmenite, and other dense unreactive minerals could also be present on channel floors and in valley networks on Mars, while banded iron formations might underlie the Martian northern plains regions. As oxygen evolved in earth's atmosphere, so too did oxide ores. By analogy, gossans above sulfide ores probably occur on Mars

  17. Global analytic treatment of terrestrial photogrammetric networks

    CERN Document Server

    Mayoud, M

    1980-01-01

    In order to solve certain special CERN metrology problems, analytical terrestrial photogrammetry may have some advantages which are first discussed along with their drawbacks and limitations. In this application, it is necessary to carry out a rigorous and global adjustment of the observations and simultaneously process all the perspective ray bundles. The basic principles, the least squares solution and the stochastic analysis of the results are presented. However, for the CERN project, one wonders if the production of digital theodolites is going to reduce the advantages of the photogrammetric method. (12 refs).

  18. MAFF monitoring of the terrestrial environment

    International Nuclear Information System (INIS)

    Sherlock, J.C.

    1991-01-01

    This paper addresses the MAFF food surveillance programme, in particular our Terrestrial Radioactivity Monitoring Programme (TRAMP), and the estimation of dietary intake of radionuclides. The MAFF programme exists primarily to demonstrate that authorized discharges of radioactivity to the environment do not result in individuals receiving doses of radiation in excess of accepted limits. The estimation radionuclide intake ensures over estimation rather than underestimation of dose. Improvements in detection limits and absorption level research could lower the calculated dose to man from radionuclides in food without losing their validity. (author)

  19. Accelerated stress testing of terrestrial solar cells

    Science.gov (United States)

    Prince, J. L.; Lathrop, J. W.

    1979-01-01

    A program to investigate the reliability characteristics of unencapsulated low-cost terrestrial solar cells using accelerated stress testing is described. Reliability (or parametric degradation) factors appropriate to the cell technologies and use conditions were studied and a series of accelerated stress tests was synthesized. An electrical measurement procedure and a data analysis and management system was derived, and stress test fixturing and material flow procedures were set up after consideration was given to the number of cells to be stress tested and measured and the nature of the information to be obtained from the process. Selected results and conclusions are presented.

  20. Late accretion to the terrestrial planets

    Science.gov (United States)

    Brasser, Ramon; Mojzsis, Stephen; Werner, Stephanie; Matsumura, Soko; Ida, Shigeru

    2017-10-01

    IntroductionIt is generally accepted that silicate-metal (`rocky') planet formation relies on coagulation from a mixture of sub-Mars sized planetary embryos and (smaller) planetesimals that dynamically emerge from the evolving circum-solar disc in the first few million years of our Solar System. Once the planets have, for the most part, assembled after a giant impact phase, they continue to be bombarded by a multitude of planetesimals left over from accretion. Here we place limits on the mass and evolution of these planetesimals based on constraints from the highly siderophile element (HSE) budget of the Moon. The terrestrial and lunar HSE budgets indicate that Earth’s and Moon’s additions through late accretion were 0.7 wt% and 0.02 wt% respectively. The disproportionate high accretion between the Earth and Moon could be explained by stochastic accretion of a few remaining Ceres-sized bodies that preferentially targeted the Earth.ResultsFrom a combination of N-body and Monte Carlo simulations of planet formation we conclude:1) matching the terrestrial to lunar HSE ratio requires that late accretion on Earth mostly consisted of a single lunar-size impactor striking the Earth before 4.45 Ga2) the flux of terrestrial impactors must have been low avoid wholesale melting of Earth's crust after 4.4 Ga[6], and to simultaneously match the number of observed lunar basins3) after the terrestrial planets have fully formed, the mass in remnant planetesimals was ~0.001 Earth mass, lower than most previous models suggest.4) Mars' HSE budget also requires a colossal impact with a Ceres-sized object before 4.43 Ga, whose visible remnant could be the hemispherical dichotomy.These conclusions lead to an Hadean eon which is more clement than assumed previously. In addition, our dynamically and geochemically self-consistent scenario requires that future N-body simulations of rocky planet formation either directly incorporate collisional grinding or rely on pebble accretion.

  1. Terrestrial plant methane production and emission

    DEFF Research Database (Denmark)

    Bruhn, Dan; Møller, Ian M.; Mikkelsen, Teis Nørgaard

    2012-01-01

    In this minireview, we evaluate all experimental work published on the phenomenon of aerobic methane (CH4) generation in terrestrial plants and plant. Clearly, despite much uncertainty and skepticism, we conclude that the phenomenon is true. Four stimulating factors have been observed to induce...... aerobic CH4 into a global budget is inadequate. Thus it is too early to draw the line under the aerobic methane emission in plants. Future work is needed for establishing the relative contribution of several proven potential CH4 precursors in plant material....

  2. Digital terrestrial television broadcasting technology and system

    CERN Document Server

    2015-01-01

    Now under massive deployment worldwide, digital terrestrial television broadcasting (DTTB) offers one of the most attractive ways to deliver digital TV over the VHF/UHF band. Written by a team of experts for specialists and non-specialists alike, this book serves as a comprehensive guide to DTTB. It covers the fundamentals of channel coding and modulation technologies used in DTTB, as well as receiver technology for synchronization, channel estimation, and equalization. It also covers the recently introduced Chinese DTTB standard, using the SFN network in Hong Kong as an example.

  3. A New Furostanol Glycoside from Tribulus terrestris

    Directory of Open Access Journals (Sweden)

    Tonghua Liu

    2010-01-01

    Full Text Available Besides two known glycosides, a new furostanol glycoside was isolated from the Fruits of Tribulus terrestris L. The structure of the new furostanol glycoside was established as 26-O-β-D-glucopyranosyl-(25S-5α-furostane-20(22-en-12-one-3β, 26-diol-3-O-α-L-rhamnopyranosyl-(1→2-[β-D-glucopyranosyl-(1→4]-β-D-galactopyranoside (1 on the basis of 1D and 2D-NMR techniques, including COSY, HMBC, and HMQC correlations.

  4. Two new furostanol saponins from Tribulus terrestris.

    Science.gov (United States)

    Xu, Ya-Juan; Xu, Tun-Hai; Zhou, Hai-Ou; Li, Bo; Xie, Sheng-Xu; Si, Yun-Shan; Liu, Yue; Liu, Tong-Hua; Xu, Dong-Ming

    2010-05-01

    Two new furostanol saponins were isolated from the fruits of Tribulus terrestris L. Their structures were established as 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furost-20(22)-en-3beta,26-diol-3-O-alpha-L-rhamnopyranosyl-(1 --> 2)-[beta-D-glucopyranosyl-(1 --> 4)]-beta-D-galactopyranoside (1) and 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furost-20(22)-en-12-one-3beta,26-diol-3-O-beta-D-galactopyranosyl-(1 --> 2)-beta-D-glucopyranosyl-(1 --> 4)-beta-D-galactopyranoside (2) on the basis of spectroscopic data as well as chemical evidence.

  5. A new furostanol glycoside from Tribulus terrestris.

    Science.gov (United States)

    Xu, Yajuan; Liu, Yonghong; Xu, Tunhai; Xie, Shengxu; Si, Yunshan; Liu, Yue; Zhou, Haiou; Liu, Tonghua; Xu, Dongming

    2010-01-27

    Besides two known glycosides, a new furostanol glycoside was isolated from the Fruits of Tribulus terrestris L. The structure of the new furostanol glycoside was established as 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furostane-20(22)-en-12-one-3beta, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-beta-D-galactopyranoside (1) on the basis of 1D and 2D-NMR techniques, including COSY, HMBC, and HMQC correlations.

  6. Elementos para volver a pensar lo comunal: nuevas formas de acceso a la tierra y presión sobre el recurso en las comunidades campesinas de Colán y Catacaos

    Directory of Open Access Journals (Sweden)

    María Luisa Burneo

    2013-12-01

    Full Text Available El presente artículo plantea que viene ocurriendo una transformación de la relación entre la tierra, los comuneros y las comunidades que, en el caso de la costa norte peruana, se vincula con una doble dinámica: (i la creciente presión externa sobre el recurso por capitales privados nacionales y trasnacionales, y (ii el surgimiento de nuevas formas y motivaciones de acceso a la tierra por los comuneros. En este escenario, las comunidades buscan desarrollar mecanismos de contención que, sin embargo, escapan a las lógicas de control propias del ámbito comunal e implican, de manera paradójica, el riesgo de un progresivo desmembramiento de porciones del territorio comunal. Para sustentar lo anterior, el texto analiza los nuevos usos (y usos potenciales de la tierra que generan expectativas entre los comuneros, así como las nuevas estrategias de acceso al recurso que se disputan diversos actores. Para ello, toma como referencia el estudio de dos comunidades de la costa norte peruana: San Lucas de Colán y San Juan Bautista de Catacaos. Retomar elementos de su historia de conformación permitirá observar cómo varían las formas de acceso a la tierra a lo largo del tiempo y qué nuevas lógicas aparecen en las últimas décadas. Finalmente, a manera de hipótesis, el artículo sugiere que estas nuevas lógicas cambian el sentido de lo comunal y la naturaleza del vínculo entre comunidad y comuneros: estos últimos buscan, de manera creciente, acceder a nuevas tierras sin que ello implique necesariamente su permanencia en el territorio comunal ni un uso productivo de sus parcelas. De esta manera, las comunidades de la costa norte se encuentran frente al reto de una posible transformación como referente principal de acceso y defensa de la tierra.

  7. Identificación de los mecanismos subyacentes a la invasión de Castor canadensis (Rodentia en el archipiélago de Tierra del Fuego, Chile Identifying the mechanisms underlying the invasion of Castor canadensis (Rodentia into Tierra del Fuego archipelago, Chile

    Directory of Open Access Journals (Sweden)

    PETRA K WALLEM

    2007-09-01

    Full Text Available Castor canadensis es considerado un ingeniero ecosistémico arquetípico, ya que altera el estado de factores bióticos y abióticos, mediante interacciones no tróficas, modificando sustancialmente los ecosistemas que habita. Esta especie fue introducida en la Isla Grande de Tierra del Fuego en 1946 por el gobierno argentino, con el fin de estimular la industria peletera. Actualmente se encuentra presente en las principales islas del archipiélago, incluyendo Tierra del Fuego, Navarino, Dawson y Hoste y ocupando habitat tan contrastantes como los bosques subpolares magallánicos, el matorral y la estepa patagónica. Su éxito en estos habitat sugiere que su expansión solo se verá limitada por la disponibilidad de recursos hídricos. De acuerdo a lo observado en Tierra del Fuego, en ausencia de un programa de control poblacional, los castores amenazan con establecerse en todos los bosques templados nativos del continente (entre los 35 y 55° S y ocupar los habitat de matorral y pastizal circundantes a los mismos. El presente artículo propone tres hipótesis referentes a los mecanismos subyacentes al éxito de esta invasión: el escape de enemigos naturales, la oportunidad de recursos, y la autofacilitación mediante interacciones no tróficas. Los antecedentes disponibles develan patrones conductuales (e.g., el establecimiento de colonias en forma independiente de la cercanía de recursos maderables, un aparente crecimiento poblacional irruptivo, así como una explotación centrada en Nothofagus pumilio, especie dominante en los bosques magallánicos que sugieren la operación de los mecanismos de escape de enemigos naturales y oportunidad de recursos. También se observa una mayor densidad de colonias activas en habitat que presentan mayor extensión de modificación ambiental, sugiriendo el accionar del mecanismo de autofacilitación. Si bien la información reunida no permite poner a prueba las hipótesis propuestas, sí entrega un marco

  8. International collaboration in Arctic terrestrial research

    Science.gov (United States)

    Walsh, J. E.

    2008-12-01

    The Arctic terrestrial region spans international borders in both North America and Eurasia, making internal collaboration essential to the monitoring and understanding of system-scale changes. Permafrost and hydrologic research in the Arctic are both benefiting from international coordination during the period of the International Polar Year. The Thermal State of Permafrost (TSP) is an IPY program that has mobilized researchers from more than 20 countries to make standardized temperature measurements in existing and new boreholes throughout the permafrost regions of both hemispheres. TSP builds on the Global Terrestrial Network on Permafrost (GTP-N), which includes the Circumarctic Active Layer Monitoring (CALM) project. This synoptic snapshot will provide a baseline for diagnoses of ongoing changes and assessments of future change on a pan-Arctic scale. Because permafrost changes affect hydrology, a relevant program is Arctic- HYDRA, for which the objectives include a characterization of the variability in the Arctic Hydrological Cycle (AHC), an examination of the linkages between atmospheric forcing and continental discharge to the ocean; and incorporation of hydrologic information into the attribution of recent variability of the Arctic system. Results presented here will focus on an assessment of the permafrost-hydrologic linkages as presently understood, with an emphasis on the key research needs to which programs such as TSP and Arctic-HYDRA can be brought to bear.

  9. Lunar apatite with terrestrial volatile abundances.

    Science.gov (United States)

    Boyce, Jeremy W; Liu, Yang; Rossman, George R; Guan, Yunbin; Eiler, John M; Stolper, Edward M; Taylor, Lawrence A

    2010-07-22

    The Moon is thought to be depleted relative to the Earth in volatile elements such as H, Cl and the alkalis. Nevertheless, evidence for lunar explosive volcanism has been used to infer that some lunar magmas exsolved a CO-rich and CO(2)-rich vapour phase before or during eruption. Although there is also evidence for other volatile species on glass spherules, until recently there had been no unambiguous reports of indigenous H in lunar rocks. Here we report quantitative ion microprobe measurements of late-stage apatite from lunar basalt 14053 that document concentrations of H, Cl and S that are indistinguishable from apatites in common terrestrial igneous rocks. These volatile contents could reflect post-magmatic metamorphic volatile addition or growth from a late-stage, interstitial, sulphide-saturated melt that contained approximately 1,600 parts per million H(2)O and approximately 3,500 parts per million Cl. Both metamorphic and igneous models of apatite formation suggest a volatile inventory for at least some lunar materials that is similar to comparable terrestrial materials. One possible implication is that portions of the lunar mantle or crust are more volatile-rich than previously thought.

  10. Equilibration of the terrestrial water, nitrogen, and carbon cycles

    OpenAIRE

    Schimel, David S.; Braswell, B. H.; Parton, W. J.

    1997-01-01

    Recent advances in biologically based ecosystem models of the coupled terrestrial, hydrological, carbon, and nutrient cycles have provided new perspectives on the terrestrial biosphere’s behavior globally, over a range of time scales. We used the terrestrial ecosystem model Century to examine relationships between carbon, nitrogen, and water dynamics. The model, run to a quasi-steady-state, shows strong correlations between carbon, water, and nitrogen fluxes that l...

  11. Distribución de tierras raras en soluciones y coloides de un sistema natural de aguas ácidas (Arroyo del Val, Zaragoza

    Directory of Open Access Journals (Sweden)

    López Julián, P. L.

    1993-04-01

    presentan los primeros resultados obtenidos sobre las concentraciones de tierras raras (REE de estas aguas ácidas (en muestras filtradas a través de mallas de 0,1 I-tm y en los coloides asociados. Las pautas de tierras raras (normalizadas frente a NASC de las aguas ácidas analizadas presentan globalmente un enriquecimiento relativo de las tierras taras pesadas (HREE respecto a las ligeras (LREE, con relaciones Lun/Lan ≈ 2. No obstante, lo más llamativo de estas pautas es el considerable enriquecimiento en las tierras raras intermedias (IREE representadas por Eu, Gd y Tb. Ello provoca que, en detalle, las pautas obtenidas para estas aguas puedan caracterizarse por un enriquecimiento en las tierras raras más pesadas desde La a Gd y por un empobrecimiento, también respecto a las más pesadas, entre Gd y Lu. Los contenidos de REE de los geles analizados son considerablemente superiores a los determinados en las aguas, presentando enriquecimientos de hasta tres y cuatro órdenes de magnitud. Las pautas de REE obtenidas para estos geles, tomados en distintos puntos del curso del Arroyo del Val, son considerablemente diferentes. La del coloide muestreado en el mismo punto que las aguas analizadas es similar a la de las soluciones, con una marcada convexidad para los IREE; la del otro gel, tomado aguas abajo respecto al anterior, presenta un perfil mucho más plano aunque todavía ligeramente convexo para los IREE. Aparentemente, el proceso de floculación coloidal observado en la primera confluencia del Arroyo del Val con un afluente de aguas neutras provoca una considerable disminución de las REE transportadas por las aguas ácidas (hasta un SO %. Yen ese punto, el coloide floculado presenta un enriquecimiento relativo en HREE respecto al observado en las aguas antes y en el punto de floculación.

  12. Conversation with Lara about the Earth and Land. (Spanish Title: Conversando con Lara sobre la Tierra y la Teirra.) Conversando com Lara sobre a Terra e a Terra

    Science.gov (United States)

    da Conceição Barbosa-Lima, Maria

    2010-12-01

    The present article is the analysis of a conversation between the author and Lara, a four-yearold- girl, enrolled in nursery school, while she makes a drawing of the Earth. It took place outside school environment and without any other person around to avoid interference during the interview. According to Ferreira & Silva (2004), a researcher can only comprehend a child's drawing, or form, by listening to him/her while he/she is creating it. Lara presented the traditional flat drawing, picturing the sky parallel to the ground, as reported by Nardi & Carvalho (1996). However, when asked to draw the World - term used by Butterworth et al. (2002), in order to avoid unnecessary confusion - she represented it by a circle, with herself on the surface. Her drawings led to the conclusion that such girl does not know yet the World in which she lives is the Earth, and probably because of that, within her age and consequent maturity, she accurately differentiates the concepts of land and Earth. El presente artículo analiza una entrevista libre, mientras una niña de 4 años y 4 meses, matriculada en el pregrado, dibuja la Tierra. Esta entrevista se realizó fuera del ambiente escolar y sin otra persona alrededor que pudiera interferir. De acuerdo con Ferreira Silva (2004), para quien investiga es posible conocer realmente lo que un niño o una niña pone en el papel a través de grafismos y/o dibujos si se lo escucha durante el proceso de creación de la escritura con imágenes. La niña, en este caso, representa la Tierra con el tradicional dibujo plano y el "cielo" paralelo al suelo, conforme analizaron Nardi & Carvalho (1996). Pero, cuando se Le solicita dibujar el "Mundo" - palabra empleada en un trabajo de Butterworth et al. (2002), con intención de no provocar "confusiones" innecesarias a sus sujetos de investigación- lo representa de forma circular, poniéndose sobre su superficie. Sus dibujos llevan a concluir que esta niña aún no tiene conocimiento que el mundo

  13. Commercialization of terrestrial applications of aerospace power technology

    International Nuclear Information System (INIS)

    Landsberg, D.R.

    1992-01-01

    The potential for commercialization of terrestrial energy systems based upon aerospace power technology's explored. Threats to the aerospace power technology industry, caused by the end of the cold war and weak world economy are described. There are also new opportunities caused by increasing terrestrial energy needs and world-wide concern for the environment. In this paper, the strengths and weaknesses of the aerospace power industry in commercializing terrestrial energy technologies are reviewed. Finally, actions which will enable the aerospace power technology industry to commercialize products into terrestrial energy markets are described

  14. Advanced Li batteries for terrestrial balloons, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — For future advanced terrestrial balloon missions, NASA requires energy dense and power dense energy storage solutions significantly exceeding the performance of...

  15. Diseño y Aplicación de Métodos para Evaluar Patologías Constructivas en el Hábitat Rural. Arquitectura de Tierra en el Noroeste Argentino

    Directory of Open Access Journals (Sweden)

    Rodolfo Rotondaro

    2004-01-01

    Full Text Available Se proponen una serie de instrumentos y procedimientos simples de gabinete y laboratorio para monitorear cuantitativa y cualitativamente los deterioros constructivos de edificios de tierra en ámbitos rurales. Los edificios elegidos son patrimoniales, materialmente similares y pertenecen al impulso constructivo colonial, valores que incentivan el estudio pormenorizado de la interacción ambiente-edificio. Esta investigación arroja interesantes resultados sobre la durabilidad de las construcciones de tierra. Además permite comparar patrones de comportamiento de este tipo de construcciones en distintos ambientes. También se evalúan los métodos empleados y se interpretan los deterioros cronológicamente, en el marco de un estudio de tipo comparativo de patologías constructivas.

  16. Workshop on Oxygen in the Terrestrial Planets

    Science.gov (United States)

    2004-01-01

    This volume contains abstracts that have been accepted for presentation at the Workshop on Oxygen in the Terrestrial Planets, July 20-23,2004, Santa Fe, New Mexico. The contents include: 1) Experimental Constraints on Oxygen and Other Light Element Partitioning During Planetary Core Formation; 2) In Situ Determination of Fe(3+)/SigmaFe of Spinels by Electron Microprobe: An Evaluation of the Flank Method; 3) The Effect of Oxygen Fugacity on Large-Strain Deformation and Recrystallization of Olivine; 4) Plagioclase-Liquid Trace Element Oxygen Barometry and Oxygen Behaviour in Closed and Open System Magmatic Processes; 5) Core Formation in the Earth: Constraints from Ni and Co; 6) Oxygen Isotopic Compositions of the Terrestrial Planets; 7) The Effect of Oxygen Fugacity on Electrical Conduction of Olivine and Implications for Earth s Mantle; 8) Redox Chemical Diffusion in Silicate Melts: The Impact of the Semiconductor Condition; 9) Ultra-High Temperature Effects in Earth s Magma Ocean: Pt and W Partitioning; 10) Terrestrial Oxygen and Hydrogen Isotope Variations: Primordial Values, Systematics, Subsolidus Effects, Planetary Comparisons, and the Role of Water; 11) Redox State of the Moon s Interior; 12) How did the Terrestrial Planets Acquire Their Water?; 13) Molecular Oxygen Mixing Ratio and Its Seasonal Variability in the Martian Atmosphere; 14) Exchange Between the Atmosphere and the Regolith of Mars: Discussion of Oxygen and Sulfur Isotope Evidence; 15) Oxygen and Hydrogen Isotope Systematics of Atmospheric Water Vapor and Meteoric Waters: Evidence from North Texas; 16) Implications of Isotopic and Redox Heterogeneities in Silicate Reservoirs on Mars; 17) Oxygen Isotopic Variation of the Terrestrial Planets; 18) Redox Exchanges in Hydrous Magma; 19) Hydrothermal Systems on Terrestrial Planets: Lessons from Earth; 20) Oxygen in Martian Meteorites: A Review of Results from Mineral Equilibria Oxybarometers; 21) Non-Linear Fractionation of Oxygen Isotopes Implanted in

  17. Informes de la construcción, Nº 523 monográfico La tierra material de construcción : una aproximación contemporánea

    OpenAIRE

    Bestraten Castells, Sandra Cinta; Hormias Laperal, Emilio

    2011-01-01

    Este documento recoge la actualidad de la arquitectura en tierra, incorporndo las novedades tecnológicas del sector, las últimas investigaciones en universidades de varios paises y los principales centros de referencia en el estudio de este campo. La publicación ha sido coordinada desde la Universidad Poltitécnica de Cataluña por los autores de la presente comunicación

  18. EL ACCESO A LA TIERRA ASUNTO CLAVE PARA LAS MUJERES CAMPESINAS EN ANTIOQUIA, COLOMBIA ACCESS TO LAND KEY ISSUE FOR FARMERS WOMEN IN ANTIOQUIA, COLOMBIA

    Directory of Open Access Journals (Sweden)

    Gloria Patricia Zuluaga Sánchez

    2011-06-01

    Full Text Available Se recogen los principales resultados de la investigación sobre la tenencia de la tierra y sus implicaciones en la vida de las mujeres de dos organizaciones campesinas ubicadas en el Departamento de Antioquia - Colombia, las cuales se desenvuelven en un contexto de agricultura campesina, donde se presenta una tendencia a la feminización de la pequeña agricultura, debido a que los hombres emigran a otras actividades económicas y/o se vinculan a grupos armados. Los objetivos fueron documentar y analizar los efectos que generan el acceso y control de la tierra por parte de las mujeres campesinas de dichas organizaciones. La metodología utilizada fue cualitativa, usando como herramientas entrevistas, talleres y recorridos en campo. Se destaca que el acceso a la tierra tiene efectos multidimensionales (ecológicos, económicos y políticos, a través de los que se expresan una serie de relaciones de género, que conllevan a una limitada distribución, acceso y uso de los recursos por parte de las mujeres. Esta problemática, requiere un reconocimiento de ellas como sujetos de derechos agrarios, de no ser así la economía campesina se hará más vulnerable de lo que actualmente es, aumentando los riesgos socioeconómicos, políticos y ambientales, no solo de las zonas rurales sino también de las ciudades, que se ven presionadas por masas de población migrante altamente empobrecida. Por todo lo anterior, es fundamental, desde una perspectiva de los derechos humanos, la disponibilidad y el acceso de los recursos productivos para las mujeres.The findings from a research project on land ownership and its implications on women’s lives are presented. The information was collected among women from two small farmer’s associations, both located in the province of Antioquia, Colombia. In these communities there is tendency toward the feminization of small scale farming, due to the fact that men migrate to other economic opportunities and/or get

  19. Accelerated stress testing of terrestrial solar cells

    Science.gov (United States)

    Lathrop, J. W.; Hawkins, D. C.; Prince, J. L.; Walker, H. A.

    1982-01-01

    The development of an accelerated test schedule for terrestrial solar cells is described. This schedule, based on anticipated failure modes deduced from a consideration of IC failure mechanisms, involves bias-temperature testing, humidity testing (including both 85-85 and pressure cooker stress), and thermal-cycle thermal-shock testing. Results are described for 12 different unencapsulated cell types. Both gradual electrical degradation and sudden catastrophic mechanical change were observed. These effects can be used to discriminate between cell types and technologies relative to their reliability attributes. Consideration is given to identifying laboratory failure modes which might lead to severe degradation in the field through second quadrant operation. Test results indicate that the ability of most cell types to withstand accelerated stress testing depends more on the manufacturer's design, processing, and worksmanship than on the particular metallization system. Preliminary tests comparing accelerated test results on encapsulated and unencapsulated cells are described.

  20. Actinide elements in aquatic and terrestrial environments

    International Nuclear Information System (INIS)

    Bondietti, E.A.

    1978-01-01

    Progress is reported in terrestrial ecology studies with regard to plutonium in biota from the White Oak Creek forest; comparative distribution of plutonium in two forest ecosystems; an ecosystem model of plutonium dynamics; actinide element metabolism in cotton rats; and crayfish studies. Progress is reported in aquatic studies with regard to transuranics in surface waters, frogs, benthic algae, and invertebrates from pond 3513; and radioecology of transuranic elements in cotton rats bordering waste pond 3513. Progress is also reported in stability of trivalent plutonium in White Oak Lake water; chemistry of plutonium, americium, curium, and uranium in pond water; uranium, thorium, and plutonium in small mammals; and effect of soil pretreatment on the distribution of plutonium

  1. The Digital Dividend of Terrestrial Broadcasting

    CERN Document Server

    Beutler, Roland

    2012-01-01

    The “digital revolution” of the last two decades has pervaded innumerable aspects of our daily lives and changed our planet irreversibly. The shift from analog to digital broadcasting has facilitated a seemingly infinite variety of new applications—audience interactivity being but one example. The greater efficiency and compression of digital media have endowed broadcasters with a “digital dividend” of spare transmission capacity over and above the requirements of terrestrial broadcasting. The question is, who will use it, and how? Comparing the European experience with that of broadcasters elsewhere in the world, the author sketches the current status of international frequency management, quantifies the value of the “dividend” itself, analyzes the details of the analog-to-digital switchovers already completed, and posits what the future holds for the sector. As we grapple with new devices, inconceivable a mere generation ago, that allow us to access digital media instantly, anywhere and at any...

  2. Solar terrestrial coupling through space plasma processes

    International Nuclear Information System (INIS)

    Birn, J.

    2000-01-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The project investigates plasma processes that govern the interaction between the solar wind, charged particles ejected from the sun, and the earth's magnetosphere, the region above the ionosphere governed by the terrestrial magnetic field. Primary regions of interest are the regions where different plasma populations interact with each other. These are regions of particularly dynamic plasma behavior, associated with magnetic flux and energy transfer and dynamic energy release. The investigations concerned charged particle transport and energization, and microscopic and macroscopic instabilities in the magnetosphere and adjacent regions. The approaches combined space data analysis with theory and computer simulations

  3. Geology and Habitability of Terrestrial Planets

    CERN Document Server

    Fishbaugh, Kathryn E; Raulin, François; Marais, David J; Korablev, Oleg

    2007-01-01

    Given the fundamental importance of and universal interest in whether extraterrestrial life has developed or could eventually develop in our solar system and beyond, it is vital that an examination of planetary habitability goes beyond simple assumptions such as, "Where there is water, there is life." This book has resulted from a workshop at the International Space Science Institute (ISSI) in Bern, Switzerland (5-9 September 2005) that brought together planetary geologists, geophysicists, atmospheric scientists, and biologists to discuss the multi-faceted problem of how the habitability of a planet co-evolves with the geology of the surface and interior, the atmosphere, and the magnetosphere. Each of the six chapters has been written by authors with a range of expertise so that each chapter is itself multi-disciplinary, comprehensive, and accessible to scientists in all disciplines. These chapters delve into what life needs to exist and ultimately to thrive, the early environments of the young terrestrial pl...

  4. Radionuclide transport processes in terrestrial ecosystems

    International Nuclear Information System (INIS)

    Whicker, F.W.

    1983-01-01

    Some major principles and the status of knowledge concerning the transport of radionuclides through terrestrial ecosystems are reviewed. Fundamental processes which control the flow of radionuclides between ecosystem components such as air, soil, plants, and animals are described, with emphasis on deposition, resuspension, plant uptake, ingestion, and assimilation. Properties of radionuclides, organisms, and ecosystems are examined in relation to their influence on the accumulation of radioactive materials by plants and animals. The effects of the physicochemical nature of the radionuclide; morphology, physiology, and behavior of the organism; and soil, nutrient, and trophic characteristics of the ecosystem are highlighted. Observations in natural ecosystems on radionuclides such as 137 Cs, 90 Sr, 131 I, 3 H, and 239 Pu are used to illustrate current concepts. An assessment of the degree to which the processes controlling radionuclide behavior are understood and of our ability to simulate and predict such behavior with computerized models is offered. Finally, brief comments are made on research needs

  5. Terrestrial nitrogen cycles: Some unanswered questions

    Science.gov (United States)

    Vitousek, P.

    1984-01-01

    Nitrogen is generally considered to be the element which most often limits the growth of plants in both natural and agricultural ecosystems. It regulates plant growth because photosynthetic rates are strongly dependent on the concentration of nitrogen in leaves, and because relatively large mounts of protein are required for cell division and growth. Yet nitrogen is abundant in the biosphere - the well-mixed pool in the atmosphere is considered inexhaustible compared to biotic demand, and the amount of already fixed organic nitrogen in soils far exceeds annual plant uptake in terrestrial ecosystems. In regions where natural vegetation is not nitrogen limited, continuous cultivation induces nitrogen deficiency. Nitrogen loss from cultivated lands is more rapid than that of other elements, and nitrogen fertilization is generally required to maintain crop yield under any continuous system. The pervasiveness of nitrogen deficiency in many natural and most managed sites is discussed.

  6. Photovoltaic design optimization for terrestrial applications

    Science.gov (United States)

    Ross, R. G., Jr.

    1978-01-01

    As part of the Jet Propulsion Laboratory's Low-Cost Solar Array Project, a comprehensive program of module cost-optimization has been carried out. The objective of these studies has been to define means of reducing the cost and improving the utility and reliability of photovoltaic modules for the broad spectrum of terrestrial applications. This paper describes one of the methods being used for module optimization, including the derivation of specific equations which allow the optimization of various module design features. The method is based on minimizing the life-cycle cost of energy for the complete system. Comparison of the life-cycle energy cost with the marginal cost of energy each year allows the logical plant lifetime to be determined. The equations derived allow the explicit inclusion of design parameters such as tracking, site variability, and module degradation with time. An example problem involving the selection of an optimum module glass substrate is presented.

  7. The origin of modern terrestrial life

    Science.gov (United States)

    Forterre, Patrick; Gribaldo, Simonetta

    2007-01-01

    The study of the origin of life covers many areas of expertise and requires the input of various scientific communities. In recent years, this research field has often been viewed as part of a broader agenda under the name of “exobiology” or “astrobiology.” In this review, we have somewhat narrowed this agenda, focusing on the origin of modern terrestrial life. The adjective “modern” here means that we did not speculate on different forms of life that could have possibly appeared on our planet, but instead focus on the existing forms (cells and viruses). We try to briefly present the state of the art about alternative hypotheses discussing not only the origin of life per se, but also how life evolved to produce the modern biosphere through a succession of steps that we would like to characterize as much as possible. PMID:19404443

  8. Effect factors for terrestrial acidification in Brazil

    DEFF Research Database (Denmark)

    Crespo Mendes, Natalia; Laurent, Alexis; Hauschild, Michael Zwicky

    To support the increased use of existing Life Cycle Impact Assessment (LCIA) methodologies across the world, new methodological elements have been developed towards spatially resolved impact assessment. Spatially resolved methods could better capture the differences of regional envir onmental...... conditions, which is an essential approach considering countries like Brazil, with high biodiversity. Previous studies have assessed the impacts of terrestrial acidification from the estimations of the potential losses of vascular plants species richness as a result of exposure to acidifying substances...... of species richness and soil pH were developed. The species richness in each ecoregion were transformed into an empirical potentially not occurring fraction, which is a zero-to-one measure used to represent the presence or absence of species. The set of data consists of 976345 records of plants occurrences...

  9. New steroidal glycosides from Tribulus terrestris L.

    Science.gov (United States)

    Chen, Gang; Liu, Tao; Lu, Xuan; Wang, Hai-Feng; Hua, Hui-Ming; Pei, Yue-Hu

    2012-01-01

    Two new steroidal glycosides were isolated from Tribulus terrestris L. Their structures were elucidated as 26-O-β-D-glucopyranosyl-5α-furostan-12-one-20(22)-ene-3β,23,26-triol-3-O-β-D-xylopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl-(1 → 4)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-galactopyranoside (1) and 26-O-β-D-glucopyranosyl-5α-furostan-20(22)-ene-3β,23,26-triol-3-O-β-D-xylopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 3)]-β-D-glucopyranosyl-(1 → 4)-[α-L-rhamnopyranosyl-(1 → 2)]-β-D-galactopyranoside (2) by spectroscopic methods including 1D and 2D NMR experiments.

  10. TERRESTRIAL PLANET FORMATION FROM AN ANNULUS

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, Kevin J.; Levison, Harold F., E-mail: kwalsh@boulder.swri.edu [Southwest Research Institute, 1050 Walnut St. Suite 300, Boulder, CO 80302 (United States)

    2016-09-01

    It has been shown that some aspects of the terrestrial planets can be explained, particularly the Earth/Mars mass ratio, when they form from a truncated disk with an outer edge near 1.0 au. This has been previously modeled starting from an intermediate stage of growth utilizing pre-formed planetary embryos. We present simulations that were designed to test this idea by following the growth process from km-sized objects located between 0.7 and 1.0 au up to terrestrial planets. The simulations explore initial conditions where the solids in the disk are planetesimals with radii initially between 3 and 300 km, alternately including effects from a dissipating gaseous solar nebula and collisional fragmentation. We use a new Lagrangian code known as LIPAD, which is a particle-based code that models the fragmentation, accretion, and dynamical evolution of a large number of planetesimals, and can model the entire growth process from km-sizes up to planets. A suite of large (∼ Mars mass) planetary embryos is complete in only ∼1 Myr, containing most of the system mass. A quiescent period then persists for 10–20 Myr characterized by slow diffusion of the orbits and continued accretion of the remaining planetesimals. This is interrupted by an instability that leads to embryos crossing orbits and embryo–embryo impacts that eventually produce the final set of planets. While this evolution is different than that found in other works exploring an annulus, the final planetary systems are similar, with roughly the correct number of planets and good Mars-analogs.

  11. The terrestrial record of Late Heavy Bombardment

    Science.gov (United States)

    Lowe, Donald R.; Byerly, Gary R.

    2018-04-01

    Until recently, the known impact record of the early Solar System lay exclusively on the surfaces of the Moon, Mars, and other bodies where it has not been erased by later weathering, erosion, impact gardening, and/or tectonism. Study of the cratered surfaces of these bodies led to the concept of the Late Heavy Bombardment (LHB), an interval from about 4.1 to 3.8 billion years ago (Ga) during which the surfaces of the planets and moons in the inner Solar System were subject to unusually high rates of bombardment followed by a decline to present low impact rates by about 3.5 Ga. Over the past 30 years, however, it has become apparent that there is a terrestrial record of large impacts from at least 3.47 to 3.22 Ga and from 2.63 to 2.49 Ga. The present paper explores the earlier of these impact records, providing details about the nature of the 8 known ejecta layers that constitute the evidence for large terrestrial impacts during the earlier of these intervals, the inferred size of the impactors, and the potential effects of these impacts on crustal development and life. The existence of this record implies that LHB did not end abruptly at 3.8-3.7 Ga but rather that high impact rates, either continuous or as impact clusters, persisted until at least the close of the Archean at 2.5 Ga. It implies that the shift from external, impact-related controls on the long-term development of the surface system on the Earth to more internal, geodynamic controls may have occurred much later in geologic history than has been supposed previously.

  12. Organización y descripción documental del Programa de Adquisición de Tierras (Antioquia, INCORA 1964-2002

    Directory of Open Access Journals (Sweden)

    Jaime A. Gómez Espinosa

    2016-05-01

    Full Text Available El siguiente texto tiene como propósito presentar los resultados del proceso de organización y descripción archivística del Programa Adquisición de Tierras del INCORA entre los años de 1964 a 2002 para el departamento de Antioquia; el cual fue financiado con recursos del Centro de Investigaciones de la Escuela Interamericana de Bibliotecología en el 2013. Inicialmente se había propuesto y aprobado la realización de una ''Historia Institucional y organización archivística de la documentación producida por el Programa de Adquisición de Tierras del INCORA: Antioquia 1961-2003'', pero por razones administrativas del proyecto –traslado de la documentación a la ciudad de Bogotá– no fue posible realizar la historia institucional. La entrega de la totalidad de la documentación de archivo correspondiente a este programa, fue recibida a satisfacción por el INCODER luego del proceso archivístico de organización y descripción bajo los parámetros que ordena el Archivo General de la Nación al INCODER, para efectos de investigaciones internas de control y por razones de las transferencias documentales periódicas. The purpose of this paper is to present the results of the archival organization and description process of the 1964-2002 INCORA Antioquia Land Acquisition Program. The Research Center at Escuela Interamericana de Bibliotecología (the Inter-American School of Library Science provided resources to fund the process in 2013. At first, the program had proposed and approved the writing of an ''institutional and organizational archival history of the 1961-2003 INCORA Antioquia land acquisition program documentation has produced '', but because of administrative reasons of the project and they transferred the documentation to the city of Bogota. Therefore, it was impossible to write the history of the Institution. INCODER received all of the documentation of the archive corresponding to this program satisfactorily, and INCODER

  13. Efecto de diferentes usos de la tierra en la composición y la abundancia de la macrofauna edáfica, en la provincia de Matanzas

    Directory of Open Access Journals (Sweden)

    Y García

    Full Text Available Se evaluó el efecto de cuatro sistemas de uso de la tierra en la riqueza y la abundancia de la macrofauna edáfica, durante el periodo lluvioso (junio-octubre del año 2011, en los municipios de Colón, Calimete y Perico (provincia de Matanzas, Cuba. El muestreo de la macrofauna se realizó según la Metodología del Programa de Investigación Internacional Biología y Fertilidad del Suelo Tropical (TSBF. Los sistemas evaluados fueron: cultivos varios (suelos con 10 años -o más- de explotación intensiva, fincas agropecuarias (suelos con más de cinco años de explotación, con laboreo mínimo y con fertilización orgánica e inorgánica, silvopastoril (suelos con más de 10 años de explotación y con una carga global de ganado vacuno entre 1,7 y 1,8 UGM/ha y pastizal (suelos con más de 10 años de explotación y con una carga global de ganado vacuno entre 1,3 y 1,5 UGM/ha. Los mayores valores de densidad y biomasa se obtuvieron en los sistemas menos perturbados, siguiendo el gradiente: silvopastoril-pastizal-fincas agropecuarias-cultivos varios. La densidad solo fue sensible en los sistemas donde hubo un contraste en cuanto a la diversidad y los estratos de vegetación. La biomasa reflejó los cambios en los diferentes usos y en el manejo de los suelos. Se demostró que los distintos usos de la tierra, así como el grado de perturbación e intensidad del manejo, influyeron en la composición y la abundancia de la macrofauna edáfica.

  14. DOMINANCIA FLORÍSTICA Y VARIABILIDAD ESTRUCTURAL EN BOSQUES DE TIERRA FIRME EN EL NOROCCIDENTE DE LA AMAZONÍA COLOMBIANA

    Directory of Open Access Journals (Sweden)

    DUQUE ÁLVARO

    2003-06-01

    Full Text Available Se presenta un estudio de la vegetación en 3.1 ha de bosque distribuidos en 3 unidadesfisiográficas: coluvios derivados de superficies de areniscas, superficies terciarias y superficiesaluviales de origen de ríos amazonenses, en un área ubicada entre el río Yarí y el sectorsuroriental de la serranía de Chiribiquete, departamento de Caquetá, Amazonía colombiana.El número de especies de plantas vasculares con DAP > 10 cm en parcelasde 0.1 ha osciló entre 25 y 60, mientras que la diversidad (número de especies/número deindividuos varió entre 0.31 y 0.94. Mediante un análisis de componentes principales se identificarontres tipos estructurales de bosque, pero sin una clara relación con la variabilidadfisiográfica en el área. Oenocarpus bataua y Clathrotropis macrocarpa fueron las especiesmás abundantes en todas las unidades fisiográficas. De acuerdo con el análisis de coordenadaspolares, las superficies terciarias y las superficies aluviales de ríos de aguas oscuras,fueron entre sí similares florísticamente, mientras que los coluvios de las mesas deareniscas muestran una ligera tendencia hacia una mayor disimilitud florística. Seconcluye que los bosques de la Amazonía colombiana son tan ricos en especiescomo los registrados en la Amazonía ecuatoriana y peruana, aunque se aprecia unaclara diferencia florística entre los bosques de tierra firme del piedemonte amazónicoen Ecuador y Perú, y los bosques del norte de la Amazonía colombiana. Los resultadosde este estudio apoyan la idea de que la especialización edáfica de las especiesarbóreas en bosques de tierra firme bien drenada en la Amazonía noroccidental es muy baja.

  15. The terrestrial biosphere in the SFR region

    Energy Technology Data Exchange (ETDEWEB)

    Jerling, L.; Isaeus, M. [Stockholm Univ. (Sweden). Dept. of Botany; Lanneck, J. [Stockholm Univ. (Sweden). Dept. of Physical Geography; Lindborg, T.; Schueldt, R. [Danish Nature Council, Copenhagen (Denmark)

    2001-03-01

    This report is a part of the SKB project 'SAFE' (Safety Assessment of the Final Repository of Radioactive Operational Waste). The aim of project SAFE is to update the previous safety analysis of SFR-1.SFR-1 is a facility for disposal of low and intermediate level radioactive waste, which is situated in bedrock beneath the Baltic Sea, one km off the coast near the Forsmark nuclear power plant in Northern Uppland. A part of the SAFE-analysis aims at analysing the transport of radionuclides in the ecosystems.To do so one has to build a model that includes a large amount of information concerning the biosphere.The first step is to collect and compile descriptions of the biosphere.This report is a first attempt to characterise the terrestrial environment of the SFR area of Forsmark. In the first part of the report the terrestrial environment, land class distribution and production of the area is described. The primary production in different terrestrial ecosystems is estimated for a model area in the Forsmark region. The estimations are based on the actual land class distribution and the values for the total primary production (d.w. above ground biomass)and the amount carbon produced, presented as g/m{sup 2} for each land class respectively. An important aspect of the biosphere is the vegetation and its development. The future development of vegetation is of interest since production,decomposition and thus storage of organic material, vary strongly among vegetation types and this has strong implications for the transport of radionuclides.Therefore an attempt to describe the development of terrestrial vegetation has been made in the second part. Any prediction of future vegetation is based on knowledge of the past together with premises for the future development.The predictions made, thus, becomes marred with errors enforced by the assumptions and incomplete information of the past. The assumptions made for the predictions in this report are crude and results

  16. The terrestrial biosphere in the SFR region

    International Nuclear Information System (INIS)

    Jerling, L.; Isaeus, M.

    2001-03-01

    This report is a part of the SKB project 'SAFE' (Safety Assessment of the Final Repository of Radioactive Operational Waste). The aim of project SAFE is to update the previous safety analysis of SFR-1.SFR-1 is a facility for disposal of low and intermediate level radioactive waste, which is situated in bedrock beneath the Baltic Sea, one km off the coast near the Forsmark nuclear power plant in Northern Uppland. A part of the SAFE-analysis aims at analysing the transport of radionuclides in the ecosystems.To do so one has to build a model that includes a large amount of information concerning the biosphere.The first step is to collect and compile descriptions of the biosphere.This report is a first attempt to characterise the terrestrial environment of the SFR area of Forsmark. In the first part of the report the terrestrial environment, land class distribution and production of the area is described. The primary production in different terrestrial ecosystems is estimated for a model area in the Forsmark region. The estimations are based on the actual land class distribution and the values for the total primary production (d.w. above ground biomass)and the amount carbon produced, presented as g/m 2 for each land class respectively. An important aspect of the biosphere is the vegetation and its development. The future development of vegetation is of interest since production,decomposition and thus storage of organic material, vary strongly among vegetation types and this has strong implications for the transport of radionuclides.Therefore an attempt to describe the development of terrestrial vegetation has been made in the second part. Any prediction of future vegetation is based on knowledge of the past together with premises for the future development.The predictions made, thus, becomes marred with errors enforced by the assumptions and incomplete information of the past. The assumptions made for the predictions in this report are crude and results in a coarse

  17. Climate control of terrestrial carbon exchange across biomes and continents

    Science.gov (United States)

    Chuixiang Yi; Daniel Ricciuto; Runze Li; John Wolbeck; Xiyan Xu; Mats Nilsson; John Frank; William J. Massman

    2010-01-01

    Understanding the relationships between climate and carbon exchange by terrestrial ecosystems is critical to predict future levels of atmospheric carbon dioxide because of the potential accelerating effects of positive climate-carbon cycle feedbacks. However, directly observed relationships between climate and terrestrial CO2 exchange with the atmosphere across biomes...

  18. Divergent apparent temperature sensitivity of terrestrial ecosystem respiration

    Science.gov (United States)

    Bing Song; Shuli Niu; Ruise Luo; Yiqi Luo; Jiquan Chen; Guirui Yu; Janusz Olejnik; Georg Wohlfahrt; Gerard Kiely; Ako Noormets; Leonardo Montagnani; Alessandro Cescatti; Vincenzo Magliulo; Beverly Elizabeth Law; Magnus Lund; Andrej Varlagin; Antonio Raschi; Matthias Peichl; Mats B. Nilsson; Lutz Merbold

    2014-01-01

    Recent studies revealed convergent temperature sensitivity of ecosystem respiration (Re) within aquatic ecosystems and between terrestrial and aquatic ecosystems. We do not know yet whether various terrestrial ecosystems have consistent or divergent temperature sensitivity. Here, we synthesized 163 eddy covariance flux sites across the world and...

  19. The terrestrial invertebrate fauna of a temporary stream in southern ...

    African Journals Online (AJOL)

    The terrestrial invertebrate fauna of an intermittent stream was examined in the absence of surface flows within the context of the flood pulse concept. Terrestrial invertebrates were collected from three sites on the Kruis River in theWestern Cape Province, South Africa, using pitfall traps within the dry stream bed over ...

  20. Plant reproductive organs and the origin of terrestrial insects

    Science.gov (United States)

    Georgy V. Stadnitsky

    1991-01-01

    It is widely believed that plants facilitated the evolution of terrestrial insects (Southwood 1973). However, the mechanisms by which this evolution occurred are not yet fully understood. I therefore propose a hypothesis about one possible mode of formation of terrestrial insects and fauna. The soil, warm shallow lagoons, tidal zones, and accumulations of detritus are...

  1. The decadal state of the terrestrial carbon cycle

    NARCIS (Netherlands)

    Velde, van der I.R.; Bloom, J.; Exbrayat, J.; Feng, L.; Williams, M.

    2016-01-01

    The terrestrial carbon cycle is currently the least constrained component of the global carbon budget. Large uncertainties stem from a poor understanding of plant carbon allocation, stocks, residence times, and carbon use efficiency. Imposing observational constraints on the terrestrial carbon cycle

  2. Growing technology earthy Tribulus terrestris (Tribulus terrestris L.) and its use

    OpenAIRE

    HUDSKÁ, Miluše

    2015-01-01

    This bachelor thesis deals with Puncturevine (Tribulus terrestris) as for planting, content substances, pharmacological use and with influences of planting technology or elicitors upon the active substance contents. Saponines, flavonoids, and phytosterols are the main active substances of Puncturevine. The saponines act as aphrodisiacs, the flavonoids treat with heart diseases and the phytosterols decrease the cholesterol concentration in blood plasma. The active substance contents depend on ...

  3. Tribulus terrestris Extract Improves Human Sperm Parameters In Vitro

    Science.gov (United States)

    Khaleghi, Sara; Bakhtiari, Mitra; Asadmobini, Atefeh; Esmaeili, Farzane

    2016-01-01

    Objective. The object of present study was to investigate the effects of direct addition of Tribulus terrestris extract on human sperm parameters. Design. Semen specimens from 40 healthy men volunteers were divided into 4 groups: one group received no treatment (control group) while the others were incubated with 20, 40, and 50 µg/mL of T terrestris extract (experimental groups). Motility, viability, and DNA fragmentation were assessed in all groups. Results. The incubation of human semen with 40 and 50 μg/mL of T terrestris extract significantly enhanced total sperm motility, number of progressive motile spermatozoa, and curvilinear velocity over 60 to 120 minutes’ holding time (P terrestris extract (P terrestris extract to human sperm could affect male fertility capacity. PMID:27694560

  4. The early evolution of the atmospheres of terrestrial planets

    CERN Document Server

    Raulin, François; Muller, Christian; Nixon, Conor; Astrophysics and Space Science Proceedings : Volume 35

    2013-01-01

    “The Early Evolution of the Atmospheres of Terrestrial Planets” presents the main processes participating in the atmospheric evolution of terrestrial planets. A group of experts in the different fields provide an update of our current knowledge on this topic. Several papers in this book discuss the key role of nitrogen in the atmospheric evolution of terrestrial planets. The earliest setting and evolution of planetary atmospheres of terrestrial planets is directly associated with accretion, chemical differentiation, outgassing, stochastic impacts, and extremely high energy fluxes from their host stars. This book provides an overview of the present knowledge of the initial atmospheric composition of the terrestrial planets. Additionally it includes some papers about the current exoplanet discoveries and provides additional clues to our understanding of Earth’s transition from a hot accretionary phase into a habitable world. All papers included were reviewed by experts in their respective fields. We are ...

  5. Tribulus terrestris Extract Improves Human Sperm Parameters In Vitro.

    Science.gov (United States)

    Khaleghi, Sara; Bakhtiari, Mitra; Asadmobini, Atefeh; Esmaeili, Farzane

    2016-09-30

    The object of present study was to investigate the effects of direct addition of Tribulus terrestris extract on human sperm parameters. Semen specimens from 40 healthy men volunteers were divided into 4 groups: one group received no treatment (control group) while the others were incubated with 20, 40, and 50 µg/mL of T terrestris extract (experimental groups). Motility, viability, and DNA fragmentation were assessed in all groups. The incubation of human semen with 40 and 50 μg/mL of T terrestris extract significantly enhanced total sperm motility, number of progressive motile spermatozoa, and curvilinear velocity over 60 to 120 minutes' holding time (P terrestris extract (P terrestris extract to human sperm could affect male fertility capacity. © The Author(s) 2016.

  6. Variación florística de especies arbóreas a escala local en un bosque de tierra firme en la Amazonia colombiana Floristic variation of canopy tree species at a local scale on tierra firme forests in colombian Amazonia

    Directory of Open Access Journals (Sweden)

    Juan Sebastian Barreto Silva

    2010-03-01

    Full Text Available El presente estudio se llevó a cabo en cinco hectáreas de una parcela permanente establecida en el Parque Nacional Amacayacu, Amazonia colombiana. En éste, se evaluó el efecto de la variación ambiental y la configuración espacial sobre los patrones florísticos de las especies arbóreas (DAP>10 cm a escala local en un bosque de tierra firme. Se estudió la variación florística y ambiental en cuadrantes de 20x20 m. Adicionalmente, se consideraron diferentes categorías de abundancia (total, alta, media y baja. Se utilizó el Análisis de Correspondencia Linealizado y el Análisis de Correspondencia Canónica, seguido de una partición de la variación, para cuantificar la magnitud a la cual el ambiente y la limitación en dispersión determinan la variación florística. La fracción espacial, representando procesos de autocorrelación como la limitación en dispersión, se analizó mediante dos métodos: Asumiendo un polinomio de tercer grado y por el método de Coordenadas Principales de Matrices Vecinas (PCNM. La diversidad beta de la parcela fue baja. El PCNM aparece como el método de análisis más apropiado para estudios a esta escala. Las diferencias florísticas explicadas a lo largo de la parcela de 5-ha fueron principalmente asociadas con procesos biológicos como la limitación en dispersión. La mayor parte de la variación florística, no obstante, no fue explicada por las variables ambientales o espaciales consideradas. En conclusión, estos resultados sugieren que procesos aleatorios son determinantes esenciales de la variación espacial de las especies arbóreas a escala local en tierra firme en los bosques en el Parque Nacional Amacayacu.This study was carried out in a 5-ha permanent plot established in the Amacayacu National Park, Colombian Amazonia. We assessed the extent at which floristic patterns of tree species were determined by either the environmental variation or the spatial configuration in tierra firme

  7. Mitología grecolatina y rock. El mito de Prometeo en letras de Extremoduro, Tierra Santa y Kutxi Romero & Ja ta Ja / Greek-latin mythology and rock. The myth of Prometheus in lyrics of Extremoduro, Tierra Santa and Kutxi Romero & Ja ta Ja

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    http://iesgtballester.juntaextremadura.net/web/profesores/tejuelo/vinculos/articulos/r17/04.pdf

    2013-06-01

    Full Text Available Resumen: A pesar de la creencia de que las letras de la música rock española actual están llenas de mensajes vacíos y de tópicos repetidos, podemos encontrar grupos y solistas cuyas composiciones se alejan de ese cliché para servir de vehículo de transmisión de cuestiones culturales como pueda ser la mitología clásica. Además, esta transmisión no siempre se queda en la mera anécdota de la cita culturalista, sino que en ocasiones va más allá, haciendo que el mito sirva como elemento de comparación o, incluso, recreándolo.Las siguientes páginas pasarán revista a la aparición del mito de Prometeo en las letras de tres grupos de rock nacional contemporáneos: Extremoduro, Tierra Santa y la colaboración entre el cantante y letrista de Marea, Kutxi Romero, con Ja ta Ja.Abstract: In spite of the belief that the lyrics of current Spanish rock music are full of empty messages and repeated topics, we can find groups and soloist whose compositions move away from that chiclé to serve as a transmission vehicle of cultural questions such as classical mythology. Besides, this transmission is not always just a mere anecdote of the culturalist quote, but on some occasions it goes further, making the myth an element of comparison, or even recreating it.The following pages will review the appearance of the Prometheus myth in the lyrics of three contemporary national rock groups: Extremoduro, Tierra Santa and the collaboration between the singer and composer of Marea, Kutxi Romero, with Ja ta Ja.

  8. The decadal state of the terrestrial carbon cycle : Global retrievals of terrestrial carbon allocation, pools, and residence times

    NARCIS (Netherlands)

    Bloom, A Anthony; Exbrayat, Jean-François; van der Velde, Ivar R; Feng, Liang; Williams, Mathew

    2016-01-01

    The terrestrial carbon cycle is currently the least constrained component of the global carbon budget. Large uncertainties stem from a poor understanding of plant carbon allocation, stocks, residence times, and carbon use efficiency. Imposing observational constraints on the terrestrial carbon cycle

  9. Primer registro de Dasypsyllus (Avesopsylla lasius lasius (Siphonaptera: Ceratophyllidae en nidos de golondrina chilena, Tachycineta meyeni (Passeriformes: Hirundinidae, en Ushuaia (Tierra del Fuego, Argentina

    Directory of Open Access Journals (Sweden)

    Rosana ARAMBURÚ

    2009-01-01

    Full Text Available La golondrina chilena, Tachycineta meyeni (Cabanis, nidifica en el centro de Chile y suroeste de Argentina. En invierno migra a Bolivia, Paraguay y al sureste de Brasil. Estas golondrinas ocuparon una serie de cajas-nido en Ushuaia, Tierra del Fuego. Luego de la temporada de cría, tratamos los nidos con acetato de etilo y los revisamos en búsqueda de artrópodos hematófagos. Encontramos pulgas adultas, que fueron fijadas, aclaradas, deshidratadas, diafanizadas y montadas en un derivado de clavo de olor para su observación al microsocopio óptico. Identificamos machos y hembras de Dasypsyllus (Avesopsylla lasius lasius (Rothschild. En Argentina, esta pulga es conocida solamente en Sierra de la Ventana (Buenos Aires, donde se la halló parasitando la golondrina barranquera, Notiochelidon cyanoleuca patagonica (Vieillot. La información disponible debería complementarse con prospecciones en localidades intermedias. Otras aves relacionadas con ambas golondrinas por la ocupación de nidos, como el rayadito (Aphrastura spinicauda (Gmelin, ratona común (Troglodytes aedon Vieillot, caminera común (Geositta cunicularia (Vieillot, hornero (Furnarius rufus (Gmelin, podrían contribuir a la dispersión de la pulga entre las dos localidades registradas.

  10. Rasgos climáticos, relieve y vegetación en tierras valencianas a través de la mirada de Cavanilles

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    Marco Molina, Juan Antonio

    2006-06-01

    Full Text Available It is focused in this report an interpretation on the bioclimatic content in the Observaciones of Cavanilles (1795-1797, which permit us to brig up a characterization of the valencian lands in different temperatures and its shades. This differentiation is a result of the use in vegetable species (carob tree and olive tree as a sign of the thermal conditions. Tempers and alive thermometers make up a binomial comparable to thermoclimates and bio-indicator plants. This parallelism has much more significant when the reflections of Cavanilles about the mountains are inclusive as well as where the native species are the ones which show the temperatures.

    Se aborda una interpretación del contenido bioclimático de las Observaciones de Cavanilles (1795-1797 que permite plantear una caracterización de las tierras valencianas en diferentes temples y sus matices. Esta diferenciación resulta de la utilización de especies vegetales (algarrobo y olivo como indicadores de las condiciones térmicas. Temples y termómetros vivos constituyen un binomio equiparable a termoclimas y plantas bioindicadoras. Paralelismo que adquiere mayor significación cuando se incluyen las reflexiones de Cavanilles sobre los montes, donde son las especies nativas las que indican el temple.

  11. MEMORIA SOCIAL Y TERRIOTORIO EN LA CONFLICTIVIDAD POR TIERRAS EN UNA COMUNIDAD INDÍGENA. UN ACERCAMIENTO DESDE LA TRADICIÓN ORAL POLITIZADA

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    DAVID FIGUEROA SERRANO

    2015-01-01

    Full Text Available El conflicto por tierras entre pueblos nahuas y mestizos en Michoacán ha sido una constante desde el siglo XIX. En ese contexto, las comunidades nahuas han sustentado la continuidad de ciertas percepciones sobre el entorno y la otredad desde la tradición oral, la cual está envuelta en dinámicas interétnicas y de poder. El objetivo de este texto es ir más allá de la visión común de la tradición oral como reminiscencias cosmogónicas; sobre todo, se busca mostrar algunas formas en que los nahuas de la comunidad de Pómaro, Michoacán, han generado memorias sociales ante los diferentes conflictos en los que se han enfrascado históricamente. En ese sentido, la tradición oral adquiere otra fisonomía desde la politización, que resignifica la realidad y las relaciones con la alteridad, donde están implícitos diversos recursos y actores sociales.

  12. Life on earth: to reduce egotism and increase cooperaation La vida en la tierra: mermarl al egoísmo y aumentar la cooperación

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    Jorge Eliécer Ossa Londoño

    2002-04-01

    Full Text Available This short essay collects the thoughts of the author stimulated by some preliminary readings on the sujet of environmental ethics. The concept of life on earth is proposed as the fundamental basis for an ethics of the inviromental. Egotism as an ontogenetc principle for the construction of the individuality of the living being: and cooperation, as a necessary organizing axis, are recognized in this context and it is proposed that a rule of thumb to manage the very complex relatinships with the environment could lay on the capacity of the human being to increase cooperation and reduce his egotism. Este corto ensayo recoge las reflexiones del autor, estimuladas por algunas lecturas preliminares sobre el tema de ética ambiental. Se propone el concepto de la vida en la tierra como base fundamental de una ética planetaria y se rescata el egoísmo ontogénico como una función necesaria para la construcción del individuo vivo y la cooperación como principio organizador necesario. Se sugiere que la capacidad del ser humano para incrementar su sentido de cooperación y para reducir su egoísmo, podrá ser la regla de oro para manejar las complejas relaciones con el entorno.

  13. Cambios en el uso de la tierra y de la infraestructura en la región de San Miguel Paulo (Sao Paulo, Brasil durante 1968-1999

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    Vanessa Meloni Massara

    2012-10-01

    Full Text Available El artículo tiene como objetivo el estudio de una zona periférica de São Paulo, en términos de cambios en el uso del suelo en paralelo con el despliegue de infraestructura de red en un intento de vincular la ocupación urbana a las mejoras en los servicios prioritarios como el abastecimiento de agua y recogida de aguas residuales. Es posible concluir que las primeras áreas ocupadas como el centro histórico y se expandió la ciudad, recibió los servicios más rápidamente, lo que indica que no sólo los factores como la densidad de población puede influir en las redes de distribución.Palabras clave: Sao Paulo (Brasil; el uso de la tierra; infraestructura___________________________AbstractThe paper aims to study a peripheral area of São Paulo in terms of changes in land use in parallel with the deployment of network infrastructure in an attempt to link the urban occupation to improvements in priority services such as water supply and sewage collection. It is possible to conclude that first occupied areas as the historical center and expanded the city, received services more quickly, indicating that not only factors such as density population can influence the distribution networks.Keywords: city of São Paulo (Brasil; land use; infrastructure.

  14. Hacia una Poética de Soledad Fariña. Prototexto y escritura cifrada en La Vocal de la Tierra

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    Javier Bello

    2009-01-01

    Full Text Available Este trabajo pretende atender al carácter mitogenésico de la narración "Al alba", pertenecienteal libro Otro cuento de pájaros (Santiago: Las Dos Fridas, 1999 de Soledad Fariña, como prototexto y paralelo de la "escritura" del Libro que fragmentariamente -desde el cuestionamiento constante de los medios de representación y la capacidad perceptiva del poema- se realizará en la trilogía La vocal de la tierra (Santiago: Cuarto Propio, 1999, que incluye los poemarios El Primer Libro (Santiago: Amaranto, 1985, Albricia (Santiago: Archivo, 1988 y En Amarillo Oscuro (Santiago: Surada, 1994, constituyéndose como una nueva escritura sagrada -alternativa al libro judeocristiano patriarcal- de identifi cación prehispánica, de epicentro genérico femenino, que constituye a la sujeto en relación protolésbica con la Madre, ofrendante con respecto a la Diosa iniciadora, e integrante de la pareja de Amazonas amantes.

  15. Agua y tierras secas. Lecturas críticas sobre la escasez hídrica en el departamento Lavalle (Mendoza

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    María Virginia Grosso Cepparo

    2017-12-01

    Full Text Available La escasez de agua constituye un problema de Estado en las tierras secas de la provincia de Mendoza, Argentina. Sin embargo, mientras el gobierno local naturaliza y difunde la escasez como un problema “de todos”, los contrastes en el acceso al agua plantean interrogantes respecto de su universalidad. Por ello, este trabajo busca repensar la escasez hídrica desde una perspectiva multidimensional que amplíe el abordaje biofísico. Específicamente, se busca analizar la mirada oficial respecto de esta problemática para, a partir de allí, comprender la manera en la que esta concepción refuerza y legitima desigualdades hídricas y territoriales en Mendoza. Se recurre a la producción de datos primarios a través de la realización de entrevistas en profundidad a funcionarios y pobladores, al análisis de documentos oficiales y de artículos periodísticos locales.

  16. La cuestión de la tierra: el despojo y la posesión en el trabajo etnográfico

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    Meghan L. Morris

    2017-01-01

    Full Text Available En Colombia, el concepto de despojo ha ido tomando fuerza en espacios sociales, burocráticos y académicos. En este artícu - lo atiendo el llamado de Gillian Hart (2006 a mantener un compromiso con la com - prensión del despojo, que considere con - juntamente sus significados dispares y sus hechos materiales mediante la etnografía, a fin de construir conceptos que ayuden a entender la complejidad. Con base en el trabajo etnográfico llevado a cabo en Urabá, un sitio a menudo considerado como "em - blemático" del despojo, tomo las posibilida - des y límites del despojo como herramienta conceptual para entender las complejidades del conflicto en la región. Sugiero que com - plementar el despojo con otras herramientas conceptuales, como la posesión, podría llevar a una comprensión más profunda de la cuestión de la tierra en una región como Urabá y a la construcción de soluciones políticas más duraderas.

  17. Los judíos de Peñafiel : una minoría confesional en tierras de señorío

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    Efrén de la Peña Barroso

    2009-01-01

    Full Text Available La comunidad judía de Peñafiel se configuró como una aljama de pequeño tamaño dentro de la provincia de Valladolid. Los préstamos y las deudas, el arrendamiento de rentas y la actividad inquisitorial reflejan que la evolución de esta comunidad no se diferenció de la del resto de juderías y aljamas castellanas, a pesar de estar ubicada en tierras de señorío. Sin embargo, es interesante destacar que algunos de sus miembros gozaron de una posición acomodada en materia económica, y que varios judíos de Peñafiel controlaron buena parte de los molinos de grano de la ribera del Duratón.The Jewish community of Peñafiel grew as a small Jewry in the province of Valladolid. Loans and debts, taxes, and Inquisition inquiries reveal that the evolution of this community does not differ from other Castilian Jewries although they were inside lordship lands. Furthermore, it has to be highlighted that some of the Jews of the Jewry had considerable wealth, and even owned most of the watermills on the banks of the Duratón river.

  18. Species richness and faunistic affinities of the Gammaridea and Corophiidea (Amphipoda from shallow waters of southern Tierra del Fuego, Argentina: preliminary results

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    Ignacio Luis Chiesa

    2005-12-01

    Full Text Available Species richness and faunistic affinities of gammaridean and corophiidean amphipods from southern Tierra del Fuego were studied. The material was collected with dredges and grabs at 7 locations (15 sampling stations in a range of 5 to 35 m depth. A total of 61 species belonging to 20 families and 43 genera were identified. The genera Cephalophoxoides, Ceradocopsis and Photis are reported for the first time from the Magellan region and 3 species belonging to Atylus, Ischyrocerus and Photis appear to be new to science. Most of the species collected belong to Phoxocephalidae, whereas most individuals were contained in the Stenothoidae and Lysianassidae s.l. The analysis of the faunistic affinities showed that 16 species (39% are endemic to the Magellan region, 9 species (22% extend to the south, 5 species (12.2% to the north and 5 other species (12.2% to both the north and south. In addition, 6 species extend beyond the Magellan region as far as Oceania.

  19. Las ciencias de la tierra y la biblia. Una aproximación desde la razón científica

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    Francisco J. Ayala

    2004-01-01

    Full Text Available El desarrollo de la Ciencia, Natural e Histórica, ha ido aportando nuevos elementos que permiten una aproximación a los relatos bíblicos desde la perspectiva de la razón científica. En este sentido, se presenta una aproximación científica, básicamente desde las Ciencias de la Tierra y teniendo en cuenta la realidad histórica del pueblo hebreo y la propia Biblia, al relato de la Creación, y los posibles núcleos histórico-científicos de los relatos del Diluvio Universal y la destrucción de Sodoma y Gomorra, de acuerdo con los últimos conocimientos disponibles. Por otra parte, se analizan los condicionamientos que los relatos bíblicos, especialmente la Creación y el Diluvio, impusieron históricamente al surgimiento de las Ciencias Geológicas.

  20. Teorías de la tierra y sistemas geológicos: un largo debate en la historia de la geología

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    Pelayo, Francisco

    1996-12-01

    Full Text Available During the second half of the XVIIIth century, the first theories about the origin and history of the Earth were issued. The interpretation that considered Deluge as a decisive factor in the modeling of land surface was the most debated until the issue of the Catastrophism and Actualism geological systems in the XIXth century. Norwadays, the polemics about methods and systems in the History of Geology is still open between geologists and historians of science.

    Durante la segunda mitad del siglo XVIII se emitieron las primeras teorías del origen e historia de la Tierra. La interpretación que consideraba al Diluvio como el factor geológico decisivo en el modelado de la superficie terrestre fue la más debatida hasta el surgimiento de los sistemas geológicos catastrofista y actualista en el siglo XIX. En la actualidad, continua abierta la polémica entre geólogos e historiadores de la ciencia sobre métodos y sistemas en la Historia de la Geología.

  1. Responsabilidad Social Matriz de indicadores sustentables que refleja el impacto de la forestación en tierras marginales del Partido de Bahía Blanca, Argentina

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    Regina del Carmen Durán Durán

    2009-01-01

    Full Text Available Actualmente, se han empezado a considerar otras obligaciones que tienen las empresas para con su comunidad; se trata de aspectos vinculados con las dimensiones sociales y ambientales. Desde este contexto, nuestro trabajo tiene como punto de partida el concepto de responsabilidad social desde la noción de sustentabilidad. El objetivo es evaluar la forestación como instrumento para mejorar la sostenibilidad de los sistemas productivos tradicionales en tierras marginales del Partido de Bahía Blanca, mitigando los impactos del desarrollo no responsable de la producción primaria. Para ello, se han identificado técnicas de manejo generadoras de externalidades positivas en otras actividades agropecuarias complementarias, donde existen limitantes edafológicas, apoyándose en las tres dimensiones del concepto de sustentabilidad: ecológica, económica, sociopolítica y cultural. De igual forma, se diseñó una matriz de evaluación y ponderación de impactos, que contempla indicadores cuantitativos y cualitativos, de cuya aplicación surge la forestación como una alternativa sustentable

  2. Características tecnológicas de la madera de palo morado (Peltogyne mexicana Martínez de tierra colorada, Guerrero, México

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    J. Navarro-Martínez

    2005-01-01

    Full Text Available El presente trabajo contribuye al conocimiento de las características y propiedades tecnológicas de la madera de Palo morado (Peltogyne mexicana Martínez, mediante la caracterización anatómica, porcentaje de elementos y determinación de las propiedades físicas y tres mecánicas. Se colectaron dos árboles en Tierra Colorada Guerrero. El material se obtuvo de trozas a 1.30 m de altura. Para el estudio macroscópico se usaron muestras de 7 x 15 x 1 cm y para el microscópico se elaboraron preparaciones fijas de cortes y de material disociado. La madera presenta un color violeta intenso, porosidad difusa, parénquima en bandas y aliforme confluente con cristales, los elementos de vaso son cortos de diámetro medio, con inclusiones, rayos uniseriados, biseriados, triseriados y raramente multiseriados; las fibras son de tipo libriforme de longitud media, diámetro fino y pared gruesa, presenta densidad básica, contracciones y dureza alta.

  3. La informalidad en la tenencia de la tierra y la producción de vivienda urbana en Facatativá (Cundinamarca 1995-2009

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    Ruth Marina Solano Diaz

    2012-06-01

    Full Text Available La apropiación informal del espacio urbano para construir vivienda es un fenómeno que se genera como respuesta a la insatisfacción del derecho fundamental a la vivienda. Dicho suceso se sustenta como producto de unas lógicas de acción social, que se alimentan de tres factores: la pobreza, el precio de la tierra urbana y los programas de formalización de la tenencia. El presente estudio pudo comprobar la hipótesis según la cual los citados factores –que para efectos de este trabajo fueron analizados durante el periodo 1995–2009- han propiciado la informalidad en el sector urbano del municipio de Facatativá, Cundinamarca. Igualmente, se explica por qué aun después de implementar los programas de formalización y los planes de ordenamiento territorial, el fenómeno persiste. Por último, con fundamento en los resultados obtenidos, se proponen alternativas que, se espera, pueden contribuir a prevenir este comportamiento.

  4. COLONIA Y EMANCIPACIÓN: PROCESOS CENTRALES RELACIONADOS CON LA PROPIEDAD DE LA TIERRA Y LOS MEDIOS DE PRODUCCIÓN EN COLOMBIA

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    Álvaro Albán Moreno

    2010-01-01

    Full Text Available La actual estructura social y económica del país está determinada por los procesos históricos que se llevaron a cabo en el territorio que hoy ocupa Colombia, tanto durante su vida colonial como durante el siglo XIX. Estos procesos determinaron la existencia de una sociedad inequitativa, en la cual la lucha por la posesión de la tierra se constituyó en el epicentro de los conflictos sociales y que ante la ausencia histórica de un proyecto político de corte liberal en el sentido filosófico (democracia, igualdad, inclusión terminó dando lugar a la génesis y reproducción de una élite que ha detentado el poder político y económico a lo largo de nuestra historia. Los aspectos anteriores son fundamentales para explicar las dificultades asociadas a las posibilidades que ha tenido nuestra nación para iniciar un verdadero despegue en el camino hacia el desarrollo.

  5. La recaudación de tributos ordinarios por la mesa arzobispal compostelana en la tierra de Santiago: alcabalas, diezmos de la mar y alfolíes

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    Rubio Martínez, Amparo

    2008-12-01

    Full Text Available The present article analyzes the perception of real tributes of ordinary character by the compostelana archiepiscopal property by the end of century XV. In him three types of taxes study: alcabalas, tithes of the sea and public granaries, although also analyze other procedures of detracción of the real rents such as the rights of perpetual ownership of you inherit that the compostelana archiepiscopal table had in some cities, villas and Earth places of Santiago.

    El presente artículo analiza la percepción de tributos reales de carácter ordinario por la hacienda arzobispal compostelana a fines del siglo XV. En él se estudian tres tipos de impuestos: alcabalas, diezmos de la mar y alfolíes, aunque también se analizan otros procedimientos de detracción de las rentas reales tales como los juros de heredad que la mesa arzobispal compostelana poseía en algunas ciudades, villas y lugares de la tierra de Santiago.

  6. Male degus, Octodon degus, modify their dustbathing behavior in response to social familiarity of previous dustbathing marks Machos de Octodon degus modifican su conducta de baños de tierra en respuesta a la familiaridad social de marcas previas

    Directory of Open Access Journals (Sweden)

    Luis A. Ebensperger

    2002-03-01

    Full Text Available A previous experiment suggested that male degus, Octodon degus, use dustbathing during intrasexual communication. Herein, we assessed whether dustbathing by male and female degus is influenced by the social familiarity of previous marks. During 15-min tests, we contrasted the behavior of degus individually exposed during to an arena containing loose, previously dustbathed sand by a same-sex and socially familiar individual with that of degus exposed to an arena with soil previously dustbathed by a same-sex but socially unfamiliar conspecific. We measured the number of dusbathing eventts per min, the latency of first dusbathing event, and the location of dusbathing events by depositor and responser individuals. Both male and female degus dusbathe at a higher rate when subjected to soil previously used by a familiar conspecific tha when exposed to a substratum previously dusbathed by an unfamiliar degu. The latency of first dusbathing event by responser male or female degu was unaffected by the social familiarity of previous marks left by depositors. Similary, the place chosen by male and female responders to conduct their dusbathing behavior was unrelated to the micro-location of previous marks left by a familiar or an unfamiliar depositor degu. We conclude that degus are capable of discriminating socially familiar fron unfamiliar scents of conspecifics and deposited in the substratum during dusbathing . We discuss the implications of such ability in the context of degu social bahavior.Un experimento previo reveló que machos del roedor Octodon degus modifican su conducta de baños de tierra en respuesta a marcas previas de otros individuos del mismo sexo. En este estudio evaluamos si los baños de tierra de machos y hembras de este roedor son o no afectados por la familiaridad social de marcas previas. Para ello, comparamos el comportamiento de degus expuestos individualmente durante experimentos de 15 min a una arena experimental marcada

  7. Estimating Exposure of Terrestrial Wildlife to Contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Sample, B.E.

    1994-01-01

    This report presents a general model for exposure of terrestrial wildlife to contaminants (Sect. 2), methods for estimating parameters of the model (Sect. 3), species specific parameters for endpoint species on the Oak Ridge Reservation (ORR) (Sect. 4), and a sample application (Sect. 5). Exposure can be defined as the coincidence in both space and time of a receptor and a stressor, such that the receptor and stressor come into contact and interact (Risk Assessment Forum 1992). In the context of ecological risk assessment, receptors include all endpoint species or communities identified for a site [see Suter (1989) and Suter et al. (1994) for discussions of ecological endpoints for waste sites]. In the context of waste site assessments, stressors are chemical contaminations, and the contact and interaction are uptake of the contaminant by the receptor. Without sufficient exposure of the receptor to the contaminants, there is no ecological risk. Unlike some other endpoint assemblages, terrestrial wildlife are significantly exposed to contaminants in multiple media. They may drink or swim in contaminated water, ingest contaminated food and soil, and breath contaminated air. In addition, because most wildlife are mobile, moving among and within habitats, exposure is not restricted to a single location. They may integrate contamination from several spatially discrete sources. Therefore, exposure models for terrestrial wildlife must include multiple media. This document provides models and parameters for estimating exposure of birds and mammals. Reptiles and amphibians are not considered because few data exist with which to assess exposure to these organisms. In addition, because toxicological data are scarce for both classes, evaluation of the significance of exposure estimates is problematic. However, the general exposure estimation procedure developed herein for birds and mammals is applicable to reptiles and amphibians. Exposure models must be appropriate to the

  8. THE COMPOSITIONAL DIVERSITY OF EXTRASOLAR TERRESTRIAL PLANETS. II. MIGRATION SIMULATIONS

    International Nuclear Information System (INIS)

    Carter-Bond, Jade C.; O'Brien, David P.; Raymond, Sean N.

    2012-01-01

    Prior work has found that a variety of terrestrial planetary compositions are expected to occur within known extrasolar planetary systems. However, such studies ignored the effects of giant planet migration, which is thought to be very common in extrasolar systems. Here we present calculations of the compositions of terrestrial planets that formed in dynamical simulations incorporating varying degrees of giant planet migration. We used chemical equilibrium models of the solid material present in the disks of five known planetary host stars: the Sun, GJ 777, HD4203, HD19994, and HD213240. Giant planet migration has a strong effect on the compositions of simulated terrestrial planets as the migration results in large-scale mixing between terrestrial planet building blocks that condensed at a range of temperatures. This mixing acts to (1) increase the typical abundance of Mg-rich silicates in the terrestrial planets' feeding zones and thus increase the frequency of planets with Earth-like compositions compared with simulations with static giant planet orbits, and (2) drastically increase the efficiency of the delivery of hydrous phases (water and serpentine) to terrestrial planets and thus produce waterworlds and/or wet Earths. Our results demonstrate that although a wide variety of terrestrial planet compositions can still be produced, planets with Earth-like compositions should be common within extrasolar planetary systems.

  9. Terrestrial ecology of semi-aquatic giant gartersnakes (Thamnophis gigas)

    Science.gov (United States)

    Halstead, Brian J.; Skalos, Shannon M.; Wylie, Glenn D.; Casazza, Michael L.

    2015-01-01

    Wetlands are a vital component of habitat for semiaquatic herpetofauna, but for most species adjacent terrestrial habitats are also essential. We examined the use of terrestrial environments by Giant Gartersnakes (Thamnophis gigas) to provide behavioral information relevant to conservation of this state and federally listed threatened species. We used radio telemetry data collected 1995–2011 from adults at several sites throughout the Sacramento Valley, California, USA, to examine Giant Gartersnake use of the terrestrial environment. We found Giant Gartersnakes in terrestrial environments more than half the time during the summer, with the use of terrestrial habitats increasing to nearly 100% during brumation. While in terrestrial habitats, we found Giant Gartersnakes underground more than half the time in the early afternoon during summer, and the probability of being underground increased to nearly 100% of the time at all hours during brumation. Extreme temperatures also increased the probability that we would find Giant Gartersnakes underground. Under most conditions, we found Giant Gartersnakes to be within 10 m of water at 95% of observations. For females during brumation and individuals that we found underground, however, the average individual had a 10% probability of being located > 20 m from water. Individual variation in each of the response variables was extensive; therefore, predicting the behavior of an individual was fraught with uncertainty. Nonetheless, our estimates provide resource managers with valuable information about the importance of protecting and carefully managing terrestrial habitats for conserving a rare semiaquatic snake.

  10. Crustal development in the terrestrial planets

    Science.gov (United States)

    Taylor, S. R.

    1985-01-01

    The development of planetary crusts may be divided into primary, resulting from melting during accretion, and secondary crusts developed by partial melting from planetary mantles. The Mercurian crust is probably primary with no compelling evidence of later basaltic extrusions. Reflectance spectral evidence for the existence Fe2(+) is equivocal. The Viking Lander XRF data on Mars indicate basaltic material at both sites 4,000 km apart. Surface aeolian processes would be expected to provide a homogeneous average of the crust, but no evidence of more siliceous material is present. This conclusion is weakly supported by the Russian gamma ray data. No evidence for granite appears from the Russian Venera XRF data which indicates MORB-type and alkali basalt (4% K2O) surface compositions. The highlands of Ishtar Terra and Aphrodite probably owe their elevation to tectonic processes rather than compositional effects. Venus may thus resemble the early Archean Earth. The terrestrial granitic continental crust is a product of episodic multiple partial melting events, probably a consequence of the presence of surface water.

  11. Some Studies of Terrestrial Impact Cratering Rate

    Directory of Open Access Journals (Sweden)

    Jetsu L.

    2011-06-01

    Full Text Available In 1984, a 28.4 Myr periodicity was detected in the ages of terrestrial impact craters and a 26 Myr periodicity in the epochs of mass extinctions of species. Periodic comet showers from the Oort cloud seemed to cause catastrophic events linked to mass extinctions of species. Our first study revealed that the only significant detected periodicity is the “human signal” caused by the rounding of these data into integer numbers. The second study confirmed that the original 28.4 Myr periodicity detection was not significant. The third study revealed that the quality and the quantity of the currently available data would allow detection of real periodicity only if all impacts have been periodic, which cannot be the case. The detection of a periodic signal, if present, requires that more craters should be discovered and the accuracy of age estimates improved. If we sometimes will be able to find the difference between the craters caused by asteroid and comet impacts, the aperiodic component could be removed. The lunar impact craters may eventually provide the required supplementary data.

  12. Dinosaurs and the Cretaceous Terrestrial Revolution

    Science.gov (United States)

    Lloyd, Graeme T; Davis, Katie E; Pisani, Davide; Tarver, James E; Ruta, Marcello; Sakamoto, Manabu; Hone, David W.E; Jennings, Rachel; Benton, Michael J

    2008-01-01

    The observed diversity of dinosaurs reached its highest peak during the mid- and Late Cretaceous, the 50 Myr that preceded their extinction, and yet this explosion of dinosaur diversity may be explained largely by sampling bias. It has long been debated whether dinosaurs were part of the Cretaceous Terrestrial Revolution (KTR), from 125–80 Myr ago, when flowering plants, herbivorous and social insects, squamates, birds and mammals all underwent a rapid expansion. Although an apparent explosion of dinosaur diversity occurred in the mid-Cretaceous, coinciding with the emergence of new groups (e.g. neoceratopsians, ankylosaurid ankylosaurs, hadrosaurids and pachycephalosaurs), results from the first quantitative study of diversification applied to a new supertree of dinosaurs show that this apparent burst in dinosaurian diversity in the last 18 Myr of the Cretaceous is a sampling artefact. Indeed, major diversification shifts occurred largely in the first one-third of the group's history. Despite the appearance of new clades of medium to large herbivores and carnivores later in dinosaur history, these new originations do not correspond to significant diversification shifts. Instead, the overall geometry of the Cretaceous part of the dinosaur tree does not depart from the null hypothesis of an equal rates model of lineage branching. Furthermore, we conclude that dinosaurs did not experience a progressive decline at the end of the Cretaceous, nor was their evolution driven directly by the KTR. PMID:18647715

  13. Mapping and Quantifying Terrestrial Vertebrate Biodiversity at ...

    Science.gov (United States)

    The ability to assess, report, map, and forecast functions of ecosystems is critical to our capacity to make informed decisions to maintain the sustainable nature of our environment. Because of the variability among living organisms and levels of organization (e.g. genetic, species, ecosystem), biodiversity has always been difficult to measure precisely, especially within a systematic manner and over multiple scales. In answer to this challenge, the U.S. Environmental Protection Agency has created a partnership with other Federal agencies, academic institutions, and Non-Governmental Organizations to develop the EnviroAtlas (https://www.epa.gov/enviroatlas), an online national Decision Support Tool that allows users to view and analyze the geographical description of the supply and demand for ecosystem services, as well as the drivers of change. As part of the EnviroAtlas, an approach has been developed that uses deductive habitat models for all terrestrial vertebrates of the conterminous United States and clusters them into biodiversity metrics that relate to ecosystem service-relevant categories. Metrics, such as species and taxon richness, have been developed and integrated with other measures of biodiversity. Collectively, these metrics provide a consistent scalable process from which to make geographic comparisons, provide thematic assessments, and to monitor status and trends in biodiversity. The national biodiversity component operates across approximatel

  14. Global habitat suitability models of terrestrial mammals.

    Science.gov (United States)

    Rondinini, Carlo; Di Marco, Moreno; Chiozza, Federica; Santulli, Giulia; Baisero, Daniele; Visconti, Piero; Hoffmann, Michael; Schipper, Jan; Stuart, Simon N; Tognelli, Marcelo F; Amori, Giovanni; Falcucci, Alessandra; Maiorano, Luigi; Boitani, Luigi

    2011-09-27

    Detailed large-scale information on mammal distribution has often been lacking, hindering conservation efforts. We used the information from the 2009 IUCN Red List of Threatened Species as a baseline for developing habitat suitability models for 5027 out of 5330 known terrestrial mammal species, based on their habitat relationships. We focused on the following environmental variables: land cover, elevation and hydrological features. Models were developed at 300 m resolution and limited to within species' known geographical ranges. A subset of the models was validated using points of known species occurrence. We conducted a global, fine-scale analysis of patterns of species richness. The richness of mammal species estimated by the overlap of their suitable habitat is on average one-third less than that estimated by the overlap of their geographical ranges. The highest absolute difference is found in tropical and subtropical regions in South America, Africa and Southeast Asia that are not covered by dense forest. The proportion of suitable habitat within mammal geographical ranges correlates with the IUCN Red List category to which they have been assigned, decreasing monotonically from Least Concern to Endangered. These results demonstrate the importance of fine-resolution distribution data for the development of global conservation strategies for mammals.

  15. Global change and terrestrial plant community dynamics.

    Science.gov (United States)

    Franklin, Janet; Serra-Diaz, Josep M; Syphard, Alexandra D; Regan, Helen M

    2016-04-05

    Anthropogenic drivers of global change include rising atmospheric concentrations of carbon dioxide and other greenhouse gasses and resulting changes in the climate, as well as nitrogen deposition, biotic invasions, altered disturbance regimes, and land-use change. Predicting the effects of global change on terrestrial plant communities is crucial because of the ecosystem services vegetation provides, from climate regulation to forest products. In this paper, we present a framework for detecting vegetation changes and attributing them to global change drivers that incorporates multiple lines of evidence from spatially extensive monitoring networks, distributed experiments, remotely sensed data, and historical records. Based on a literature review, we summarize observed changes and then describe modeling tools that can forecast the impacts of multiple drivers on plant communities in an era of rapid change. Observed responses to changes in temperature, water, nutrients, land use, and disturbance show strong sensitivity of ecosystem productivity and plant population dynamics to water balance and long-lasting effects of disturbance on plant community dynamics. Persistent effects of land-use change and human-altered fire regimes on vegetation can overshadow or interact with climate change impacts. Models forecasting plant community responses to global change incorporate shifting ecological niches, population dynamics, species interactions, spatially explicit disturbance, ecosystem processes, and plant functional responses. Monitoring, experiments, and models evaluating multiple change drivers are needed to detect and predict vegetation changes in response to 21st century global change.

  16. Biomass allocation patterns across China's terrestrial biomes.

    Directory of Open Access Journals (Sweden)

    Limei Wang

    Full Text Available Root to shoot ratio (RS is commonly used to describe the biomass allocation between below- and aboveground parts of plants. Determining the key factors influencing RS and interpreting the relationship between RS and environmental factors is important for biological and ecological research. In this study, we compiled 2088 pairs of root and shoot biomass data across China's terrestrial biomes to examine variations in the RS and its responses to biotic and abiotic factors including vegetation type, soil texture, climatic variables, and stand age. The median value of RS (RSm for grasslands, shrublands, and forests was 6.0, 0.73, and 0.23, respectively. The range of RS was considerably wide for each vegetation type. RS values for all three major vegetation types were found to be significantly correlated to mean annual precipitation (MAP and potential water deficit index (PWDI. Mean annual temperature (MAT also significantly affect the RS for forests and grasslands. Soil texture and forest origin altered the response of RS to climatic factors as well. An allometric formula could be used to well quantify the relationship between aboveground and belowground biomass, although each vegetation type had its own inherent allometric relationship.

  17. Redox Conditions Among the Terrestrial Planets

    Science.gov (United States)

    Jones, J. H.

    2004-01-01

    Early solar system conditions should have been extremely reducing. The redox state of the early solar nebula was determined by the H2O/H2 of the gas, which is calculated (based on solar composition) to have been about IW-5. At high temperature under such conditions, ferrous iron would exist only as a trace element in silicates and the most common type of chondritic material should have been enstatite chondrites. The observation that E-chondrites form only a subset of the chondrite suite and that the terrestrial planets (Earth, Moon, Mars, Venus, 4 Vesta) contain ferrous and ferric iron as major and minor elements, respectively, implies that either most chondritic materials formed under conditions that were not solar or that early-formed metals oxidized at low temperature, producing FeO. For example, equilibrated ordinary chondrites (by definition, common chondritic materials), by their phase assemblage of olivine, orthopyroxene and metal, must fall not far from the QFI (Quartz-Fayalite-Iron) oxygen buffer. The QFI buffer is about IW-0.5 and, as we shall see, this fo2 is close to that inferred for many materials in the inner solar system.

  18. Isotope powered Stirling generator for terrestrial applications

    International Nuclear Information System (INIS)

    Tingey, G.L.; Sorensen, G.C.; Ross, B.A.

    1995-01-01

    An electric power supply, small enough to be man-portable, is being developed for remote, terrestrial applications. This system is designed for an operating lifetime of five years without maintenance or refueling. A small Radioisotope Stirling Generator (RSG) has been developed. The energy source of the generator is a 60 watt plutonium-238 fuel clad used in the General Purpose Heat Sources (GPHS) developed for space applications. A free piston Stirling Engine drives a linear alternator to convert the heat to power. The system weighs about 7.5 kg and produces 11 watts AC power with a conversion efficiency of 18.5%. Two engine models have been designed, fabricated, and tested to date: (a) a developmental model instrumented to confirm and test parameters, and (b) an electrically heated model with an electrical heater equipped power input leads. Critical components have been tested for 10,000 to 20,000 hours. One complete generator has been operating for over 11,000 hours. Radioisotope heated prototypes are expected to be fabricated and tested in late 1995

  19. Isotope powered stirling generator for terrestrial applications

    International Nuclear Information System (INIS)

    Tingey, G.L.; Sorensen, G.C.; Ross, B.A.

    1995-01-01

    An electric power supply, small enough to be man-portable, is being developed for remote, terrestrial applications. This system is designed for an operating lifetime of five years without maintenance or refueling. A small Radioisotope Stirling Generator (RSG) has been developed. The energy source of the generator is a 60 watt plutonium-238 fuel clad used in the General Purpose Heat Sources (GPHS) developed for space applications. A free piston Stirling ENgine drives a linear alternator to convert the heat to power. The system weighs about 7.5 kg and produces 11 watts AC power with a conversion efficiency of 18.5%. Two engine models have been designed, fabricated, and tested to data: (a) a development model instrumented to confirm and test parameters, and (b) an electrically heated model with an electrical heater equipped power input leads. Critical components have been tested for 10,000 to 20,000 hours. One complete generator has been operating for over 11,000 hours. Radioisotope heated prototypes are expected to be fabricated and tested in late 1995. copyright 1995 American Institute of Physics

  20. Terrestrial nitrogen-carbon cycle interactions at the global scale.

    Science.gov (United States)

    Zaehle, S

    2013-07-05

    Interactions between the terrestrial nitrogen (N) and carbon (C) cycles shape the response of ecosystems to global change. However, the global distribution of nitrogen availability and its importance in global biogeochemistry and biogeochemical interactions with the climate system remain uncertain. Based on projections of a terrestrial biosphere model scaling ecological understanding of nitrogen-carbon cycle interactions to global scales, anthropogenic nitrogen additions since 1860 are estimated to have enriched the terrestrial biosphere by 1.3 Pg N, supporting the sequestration of 11.2 Pg C. Over the same time period, CO2 fertilization has increased terrestrial carbon storage by 134.0 Pg C, increasing the terrestrial nitrogen stock by 1.2 Pg N. In 2001-2010, terrestrial ecosystems sequestered an estimated total of 27 Tg N yr(-1) (1.9 Pg C yr(-1)), of which 10 Tg N yr(-1) (0.2 Pg C yr(-1)) are due to anthropogenic nitrogen deposition. Nitrogen availability already limits terrestrial carbon sequestration in the boreal and temperate zone, and will constrain future carbon sequestration in response to CO2 fertilization (regionally by up to 70% compared with an estimate without considering nitrogen-carbon interactions). This reduced terrestrial carbon uptake will probably dominate the role of the terrestrial nitrogen cycle in the climate system, as it accelerates the accumulation of anthropogenic CO2 in the atmosphere. However, increases of N2O emissions owing to anthropogenic nitrogen and climate change (at a rate of approx. 0.5 Tg N yr(-1) per 1°C degree climate warming) will add an important long-term climate forcing.