First results from an experiment excluding three sizes classes of herbivores from tundra vegetation in southern Yamal, Russia

2016 ◽  
Vol 6 (2) ◽  
pp. 132-140
Author(s):  
Capucine Baubin ◽  
Dorothée Ehrich ◽  
Virve Ravolainen ◽  
Svetlana Sokovina Abdulmanova ◽  
Svetlana Ektova ◽  
...  
Keyword(s):  
Grazing Pressure ◽  
Yamal Peninsula ◽  
Exclosure Experiment ◽  
Plant Groups ◽  
Tundra Vegetation ◽  
First Results ◽  
Herbivore Faeces ◽  
Growing Conditions ◽  
Plant Herbivore ◽  
The Impact

Plant-herbivore relationships are important for the functioning of tundra ecosystems. Here, we report the first results from an exclosure experiment that, something very few studies have done, separated the impact of three sizes of herbivores (small, medium and large) on nine functional groups of plants in the low arctic tundra of the Yamal Peninsula (Russia). Herbivore faeces counts in the exclosures and pictures from automatic cameras proved that the experimental setup worked. The majority of plant groups did not respond to exclusion of herbivores, supporting our expectation that vegetation responses in tundra are generally too slow to be measured during one growing season. The plant groups with highest growth rates and palatability (forbs and grasses) increased their biomass in meadows associated to tall willow shrubs when reindeer were excluded. This result was expected based on studies from other arctic regions. Our results also suggested that willow meadows and forb tundra, which are focal habitat for herbivores, are resilient and have the capacity to increase their biomass over a short term. We expect this experiment to provide valuable information on how different plant functional types and habitats with different growing conditions and importance to herbivores respond to relaxed grazing pressure from a variety of tundra herbivores.

scholarly journals Mixed NNLO QCD×electroweak corrections of $$ \mathcal{O} $$(Nfαsα) to single-W/Z production at the LHC

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Stefan Dittmaier ◽  
Timo Schmidt ◽  
Jan Schwarz
Keyword(s):  
Z Bosons ◽  
Leading Order ◽  
Current Standard ◽  
Gauge Invariant ◽  
Mass Distributions ◽  
Self Energy ◽  
Electroweak Gauge Boson ◽  
First Results ◽  
Invariant Part ◽  
The Impact

Abstract First results on the radiative corrections of order $$ \mathcal{O} $$ O (Nfαsα) are presented for the off-shell production of W or Z bosons at the LHC, where Nf is the number of fermion flavours. These corrections comprise all diagrams at $$ \mathcal{O} $$ O (αsα) with closed fermion loops, form a gauge-invariant part of the next-to-next-to-leading-order corrections of mixed QCD×electroweak type, and are the ones that concern the issue of mass renormalization of the W and Z resonances. The occurring irreducible two-loop diagrams, which involve only self-energy insertions, are calculated with current standard techniques, and explicit analytical results on the electroweak gauge-boson self-energies at $$ \mathcal{O} $$ O (αsα) are given. Moreover, the generalization of the complex-mass scheme for a gauge-invariant treatment of the W/Z resonances is described for the order $$ \mathcal{O} $$ O (αsα). While the corrections, which are implemented in the Monte Carlo program Rady, are negligible for observables that are dominated by resonant W/Z bosons, they affect invariant-mass distributions at the level of up to 2% for invariant masses of ≳ 500 GeV and are, thus, phenomenologically relevant. The impact on transverse-momentum distributions is similar, taking into account that leading-order predictions to those distributions underestimate the spectrum.

Cooling Efficiencies of a NiTi-Based Cooling Process

2013 ◽  
Author(s):  
Marvin Schmidt ◽  
Andreas Schütze ◽  
Stefan Seelecke
Keyword(s):  
Solid State ◽  
Thermodynamic Analysis ◽  
Cooling System ◽  
Analysis Method ◽  
Efficiency Ratio ◽  
Cooling Process ◽  
First Results ◽  
Work Input ◽  
Underlying Mechanisms ◽  
The Impact

Energy saving and environmental protection are topics of growing interest. In the light of these aspects alternative refrigeration principles become increasingly important. Shape memory alloys (SMA), especially NiTi alloys, generate a large amount of latent heat during solid state phase transformations, which can lead to a significant cooling effect in the material. These materials do not only provide the potential for an energy-efficient cooling process, they also minimize the impact on the environment by reducing the need for conventional ozone-depleting refrigerants. Our paper, presenting first results obtained in a project within the DFG Priority Program SPP 1599 “Ferroic Cooling”, focuses on the thermodynamic analysis of a NiTi-based cooling system. We first introduce a suitable cooling process and subsequently illustrate the underlying mechanisms of the process in comparison with the conventional compression refrigeration system. We further introduce a graphical solution to calculate the energy efficiency ratio of the system. This thermodynamic analysis method shows the necessary work input and the heat absorption of the SMA in stress/strain- or temperature/entropy-diagrams, respectively. The results of the calculations underline the high potential of this solid-state cooling methodology.

Fungi Associated with Garlic During the Cropping Season, with Focus on Fusarium proliferatum and F. oxysporum

2021 ◽  
Author(s):  
Letizia Mondani ◽  
Giorgio Chiusa ◽  
Paola Battilani
Keyword(s):  
Seed Transmission ◽  
Fusarium Proliferatum ◽  
Growth Stages ◽  
Sowing Time ◽  
Dry Rot ◽  
Cropping Season ◽  
Rainy Weather ◽  
Crop Growth Stage ◽  
Growing Conditions ◽  
The Impact

Fusarium proliferatum has been reported as the main causal agent of garlic dry rot during the postharvest stage, but information on this fungus during the crop growth stage is lacking. We focused on the cropping season of garlic (Allium sativum L.) in the field, until its harvest, with the aim of clarifying the role of F. proliferatum in bulb infection as well as the impact of crop growing conditions on pathogen-plant interaction. Studies were conducted in Piacenza (northern Italy) for three seasons from 2016 to 2019. Six garlic farms were sampled. A different field was sampled every year. Soil samples were recovered at sowing time for the counting of fungal colony forming units (CFU). Plant samples were collected at three growth stages, from BBCH 15 (fifth leaf visible) to BBCH 49 (ripening), for which disease severity assessment and fungi isolations were performed. Fusarium was the most frequently isolated genus, of which F. proliferatum and F. oxysporum were the dominant species. F. proliferatum registered the highest incidence in all the farms tested, but F. oxysporum was dominant in the first year of the study. F. oxysporum incidence was correlated with dry weather, whereas F. proliferatum was correlated with rainy weather. In conclusion, our result confirms the association of F. proliferatum with garlic bulbs from the crop’s early growth stages, suggesting potential seed transmission as a source of this fungal pathogen. Further studies should investigate the link between fusaria occurrence in the field and dry rot outbreaks occurring postharvest and during storage of garlic.

scholarly journals Response of Sensitive and Resistant Snap Bean Genotypes to Nighttime Ozone Concentration

2020 ◽  
Vol 145 (6) ◽  
pp. 331-339
Author(s):  
Kirsten L. Lloyd ◽  
Donald D. Davis ◽  
Richard P. Marini ◽  
Dennis R. Decoteau
Keyword(s):  
Leaf Age ◽  
Acute Injury ◽  
Yield Response ◽  
Yield Losses ◽  
Foliar Injury ◽  
Snap Bean ◽  
Stirred Tank Reactors ◽  
First Results ◽  
Significant Yield ◽  
The Impact

Effects of nighttime (2000 to 0700 hr) O3 on the pod mass of sensitive (S156) and resistant (R123) snap bean (Phaseolus vulgaris) genotypes were assessed using continuous stirred tank reactors located within a greenhouse. Two concentration-response relationship trials were designed to evaluate yield response to nighttime O3 exposure (10 to 265 ppb) in combination with daytime exposure at background levels (44 and 62 ppb). Three replicated trials tested the impact of nighttime O3 treatment at means of 145, 144, and 145 ppb on yields. In addition, stomatal conductance (gS) measurements documented diurnal variations and assessed the effects of genotype and leaf age. During the concentration-response experiments, pod mass had a significant linear relationship with the nighttime O3 concentration across genotypes. Yield losses of 15% and 50% occurred at nighttime exposure levels of ≈45 and 145 ppb, respectively, for S156, whereas R123 yields decreased by 15% at ≈150 ppb. At low nighttime O3 levels of ≈100 ppb, R123 yields initially increased up to 116% of the treatment that received no added nighttime O3, suggesting a potential hormesis effect for R123, but not for S156. Results from replicated trials revealed significant yield losses in both genotypes following combined day and night exposure, whereas night-only exposure caused significant decreases only for S156. The gS rates ranged from less than 100 mmol·m−2·s−1 in the evening to midday levels more than 1000 mmol·m−2·s−1. At sunrise and sunset, S156 had significantly higher gS rates than R123, suggesting a greater potential O3 flux into leaves. Across genotypes, younger rapidly growing leaves had higher gS rates than mature fully expanded leaves when evaluated at four different times during the day. Although these were long-term trials, gS measurements and observations of foliar injury development suggest that acute injury, occurring at approximately the time of sunrise, also may have contributed to yield losses. To our knowledge, these are the first results to confirm that the relative O3 sensitivity of the S156/R123 genotypes is valid for nighttime exposure.

scholarly journals Macro and microeconomic analysis of the impact of the covid-19 pandemic in Chile and the projections of the central bank's

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Rodrigo Barra Novoa
Keyword(s):  
Central Bank ◽  
Medium Term ◽  
Social Growth ◽  
Representative Data ◽  
First Approximation ◽  
Microeconomic Analysis ◽  
The Social ◽  
First Results ◽  
Business Profitability ◽  
The Impact

This article offers a first approximation of the impacts of the COVID-19 pandemic on the Chilean macro and microeconomic environment, using representative data from the latest formal surveys in the country. Here, the number of active firms plummeted in part due to the social crisis that began on October 18, 2019, and losses were felt in most industries due to the pandemic crisis that continues to generate job losses and low business profitability. These first results have implications for central bank policies and can predict medium and medium-term projections, especially for the country's economic and social growth.

scholarly journals Seismostratigraphic Interpretation of Upper Cretaceous Reservoir from the Carpathian Foreland, Southern Poland

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7776
Author(s):  
Andrzej Urbaniec ◽  
Anna Łaba-Biel ◽  
Anna Kwietniak ◽  
Imoleayo Fashagba
Keyword(s):  
Late Cretaceous ◽  
Upper Cretaceous ◽  
Tectonic Setting ◽  
Small Scale ◽  
Reservoir Properties ◽  
Southern Poland ◽  
Seismic Sequence Stratigraphy ◽  
First Results ◽  
Depositional Architecture ◽  
The Impact

The Upper Cretaceous complex in the central part of the Carpathian Foreland (southern Poland) is relatively poorly recognized and described. Its formations can be classified as unconventional reservoir due to poor reservoir properties as well as a low recovery factor. The main aim of the article is to expand knowledge with conclusions resulting from the analysis of the latest seismic data with the application of seismic sequence stratigraphy. Moreover, the seismic attributes analysis was utilized. The depositional architecture recognition based on both chronostratigraphic horizons and Wheeler diagram interpretations was of paramount importance. A further result was the possibility of using the chronostratigraphic image for tectonostratigraphic interpretation. Two distinguished tectonostratigraphic units corresponding to megasequences were recognized. A tectonic setting of the analyzed interval is associated with global processes noticed by other authors in other parts of the central European Late Cretaceous basin, but also locally accompanied by evidence of small-scale tectonics. This study fills the gap on the issue of paleogeography in the Late Cretaceous sedimentary basin of the Carpathian Foreland. It presents the first results of detailed reconstruction of the basin paleogeography and an attempt to determine the impact of both eustatic and tectonic factors on sedimentation processes.

scholarly journals Effects of reindeer grazing and recovery after cessation of grazing on the ground-dwelling spider assemblage in Finnish Lapland

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7330
Author(s):  
Teemu Saikkonen ◽  
Varpu Vahtera ◽  
Seppo Koponen ◽  
Otso Suominen
Keyword(s):  
Species Richness ◽  
Rangifer Tarandus ◽  
Forest Ecosystems ◽  
Grazing Pressure ◽  
Ground Vegetation ◽  
Total Abundance ◽  
Finnish Lapland ◽  
Species Specific ◽  
The Impact

The effect of reindeer Rangifer tarandus L. grazing on the ground-dwelling spider assemblage in Northern Finland was studied. Changes in species richness, abundance and evenness of spider assemblages were analyzed in relation to changes in vegetation and environmental factors in long term grazed and ungrazed sites as well as sites that had recently switched from grazed to ungrazed and vice versa. Grazing was found to have a significant impact on height and biomass of lichens and other ground vegetation. However, it seemed not to have an impact on the total abundance of spiders. This is likely caused by opposing family and species level responses of spiders to the grazing regime. Lycosid numbers were highest in grazed and linyphiid numbers in ungrazed areas. Lycosidae species richness was highest in ungrazed areas whereas Linyphiidae richness showed no response to grazing. Four Linyphiidae, one Thomisidae and one Lycosidae species showed strong preference for specific treatments. Sites that had recovered from grazing for nine years and the sites that were grazed for the last nine years but were previously ungrazed resembled the long term grazed sites. The results emphasize the importance of reindeer as a modifier of boreal forest ecosystems but the impact of reindeer grazing on spiders seems to be family and species specific. The sites with reversed grazing treatment demonstrate that recovery from strong grazing pressure at these high latitudes is a slow process whereas reindeer can rapidly change the conditions in previously ungrazed sites similar to long term heavily grazed conditions.

Understanding the impact of growing conditions on oysters: a study of their sensory and biochemical characteristics

2013 ◽  
Vol 46 (3) ◽  
pp. 637-646 ◽  
Author(s):  
Maëva Cochet ◽  
Malcolm Brown ◽  
Peter Kube ◽  
Nick Elliott ◽  
Conor Delahunty
Keyword(s):  
Biochemical Characteristics ◽  
Growing Conditions ◽  
The Impact

Towards SI-traceable Isotope Ratios of Greenhouse Gases

2021 ◽  
Author(s):  
Lukas Flierl ◽  
Javis Nwaboh ◽  
Olaf Rienitz ◽  
Olav Werhahn ◽  
Volker Ebert
Keyword(s):  
Carbon Dioxide ◽  
Greenhouse Gases ◽  
Isotope Ratio ◽  
Isotope Ratio Mass Spectrometry ◽  
Isotope Ratios ◽  
Oxygen Isotope Ratios ◽  
Carbon And Oxygen Isotope ◽  
First Results ◽  
Buoyancy Correction ◽  
The Impact

<p>The emission of greenhouse gases and the resulting global warming is one of the most important and challenging issues of the 21<sup>st</sup> century. Carbon dioxide is one of the major contributors to the greenhouse effect and its atmospheric abundance has growing constantly since the beginning of the industrialization. The isotope ratios n(<sup>13</sup>C)/n(<sup>12</sup>C) and n(<sup>18</sup>O)/n(<sup>16</sup>O) are important tools for studying the impact of anthropogenic CO<sub>2</sub>. Usually, isotopic compositions of CO<sub>2</sub> are reported as δ-values, that express isotope ratios relative to an artifact based on a fossil calcite called VPDB. This relative VPDB scale was necessary, since absolute and SI-traceable isotope ratios of CO<sub>2</sub> are currently not available, neither by isotope ratio mass spectrometry (IRMS) nor by optical isotope ratio spectroscopy (OIRS). In this study we present a potential way of deriving absolute carbon and oxygen isotope ratios of carbon dioxide via IRMS based on the gravimetric mixture approach. Besides practical improvements like an air buoyancy correction scheme for masses of gases, we show first results applying our method which demonstrate its feasibility, limitations, and achievable uncertainties. Also, we show the mathematics behind our approach and discuss further improvements and applications. Furthermore, we show how these absolute ratios can be used in field applications by OIRS methods including a new approach on OIRS uncertainty assessments according to the GUM. For this contribution we report on our recent results within in the European metrology research projects SIRS (16ENV06). and STELLAR (19ENV05).</p>

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