Effect of Artificial Regime Shifts and Biotic Factors on the Intensity of Foraging of Planktivorous Fish

It is still to be confirmed whether global warming with its predicted elevated water temperature will cause an increase in predation and alter phenological and physiological processes leading to changes in the size of aquatic organisms. In an experimental system of water column stratification simulating a natural combination of field conditions, we created artificial abiotic factors that mimicked the natural environment, i.e., light intensity, oxygen conditions, and thermal stratification. Subsequently, we added biotic factors such as algae, Daphnia, and planktivorous fish. We studied the intensity of foraging of planktivorous fish on individuals of Daphnia per min in different conditions of biotic and abiotic gradients. We demonstrated a possible scenario involving the risk of elimination of large prey within macrocladocera communities by predatory pressure as a result of climate change. A higher intensity of foraging of planktivorous fish caused or increased the occurrence of larger groups of planktonic animals with a smaller body size. The mechanisms of a future scenario were discovered at a higher trophic level in the aquatic environment.

Growth and toxin production of phomopsin A and ochratoxin A forming fungi under different storage conditions in a pea (Pisum sativum) model system

Phomopsins are mycotoxins mainly infesting lupines, with phomopsin A (PHOA) being the main mycotoxin. PHOA is produced by Diaporthe toxica, formerly assigned as toxigenic Phomopsis leptostromiformis, causing infections in lupine plants and harvested seeds. However, Diaporthe species may also grow on other grain legumes, similar to Aspergillus westerdijkiae as an especially potent ochratoxin A (OTA) producer. Formation of PHOA and OTA was investigated on whole field peas as model system to assess fungal growth and toxin production at adverse storage conditions. Field pea samples were inoculated with the two fungal strains at two water activity (aw) values of 0.94 and 0.98 and three different levels of 30, 50, and 80% relative air humidity.After 14 days at an aw value of 0.98, the fungi produced 4.49 to 34.3 mg/kg PHOA and 1.44 to 3.35 g/kg OTA, respectively. Strains of D. toxica also tested showed higher PHOA concentrations of 28.3 to 32.4 mg/kg.D. toxica strains did not grow or produce PHOA at an aw values of 0.94, while A. westerdijkiae still showed growth and OTA production.Elevated water activity has a major impact both on OTA and, even more pronouncedly, on PHOA formation and thus, proper drying and storage of lupins as well as other grain legumes is crucial for product safety.

New Evidence for Wet Accretion of Inner Solar System Planetesimals from Meteorites Chelyabinsk and Benenitra

We investigated the hydrogen isotopic compositions and water contents of pyroxenes in two recent ordinary chondrite falls, namely, Chelyabinsk (2013 fall) and Benenitra (2018 fall), and compared them to three ordinary chondrite Antarctic finds, namely, Graves Nunataks GRA 06179, Larkman Nunatak LAR 12241, and Dominion Range DOM 10035. The pyroxene minerals in Benenitra and Chelyabinsk are hydrated (∼0.018–0.087 wt.% H2O) and show D-poor isotopic signatures (δDSMOW from −444‰ to −49‰). On the contrary, the ordinary chondrite finds exhibit evidence of terrestrial contamination with elevated water contents (∼0.039–0.174 wt.%) and δDSMOW values (from −199‰ to −14‰). We evaluated several small parent-body processes that are likely to alter the measured compositions in Benenitra and Chelyabinsk and inferred that water loss in S-type planetesimals is minimal during thermal metamorphism. Benenitra and Chelyabinsk hydrogen compositions reflect a mixed component of D-poor nebular hydrogen and water from the D-rich mesostases. A total of 45%–95% of water in the minerals characterized by low δDSMOW values was contributed by nebular hydrogen. S-type asteroids dominantly composed of nominally anhydrous minerals can hold 254–518 ppm of water. Addition of a nebular water component to nominally dry inner solar system bodies during accretion suggests a reduced need of volatile delivery to the terrestrial planets during late accretion.

Eolian stratigraphic record of environmental change through geological time

The terrestrial sedimentary record provides a valuable archive of how ancient depositional systems responded to and recorded changes in Earth’s atmosphere, biosphere, and geosphere. However, the record of these environmental changes in eolian sedimentary successions is poorly constrained and largely unquantified. Our study presents the first global-scale, quantitative investigation of the architecture of eolian systems through geological time via analysis of 55 case studies of eolian successions. Eolian deposits accumulating (1) under greenhouse conditions, (2) in the presence of vascular plants and grasses, and (3) in rapidly subsiding basins associated with the rifting of supercontinents are represented by significantly thicker eolian dune-set, sand-sheet, and interdune architectural elements. Pre-vegetation eolian systems are also associated with more frequent interactions with non-eolian environments. The interplay of these forcings has resulted in dune-set thicknesses that tend to be smallest and largest in Proterozoic and Mesozoic successions, respectively. In the Proterozoic, the absence of sediment-binding plant roots rendered eolian deposits susceptible to post-depositional wind deflation and reworking by fluvial systems, whereby highly mobile channels reworked contiguous eolian deposits. During the Mesozoic, humid greenhouse conditions (associated with relatively elevated water tables) and high rates of basin subsidence (associated with the breakup of Pangea) favored the rapid transfer of eolian sediment beneath the erosional baseline. The common presence of vegetation promoted accumulation of stabilizing eolian systems. These factors acted to limit post-depositional reworking. Eolian sedimentary deposits record a fingerprint of major environmental changes in Earth history: climate, continental configuration, tectonics, and land-plant evolution.

Microwave Limb Sounder (MLS) observations of biomass burning products in the stratosphere from Canadian forest fires in August 2017

Forest fires in British Columbia in August 2017 caused a pyrocumulonimbus event that injected a polluted air mass into the lower stratosphere. The Microwave Limb Sounder (MLS) on the Aura satellite first observed the polluted air mass on 14 August 2017 and continued to observe it for 60 d (100 d in water vapour). We estimate the mass of CO injected into the stratosphere to be 2400 Gg. Events in which a fire injects its burning products directly into the stratosphere are rare: this is the third of four such events in the 16 years since the launch of Aura, the second largest of the four events, and the only one in the Northern Hemisphere. The other three events occurred in Australia in December 2006, February 2009 and from December 2019 to January 2020. Unlike the 2006 and 2009 events, but like the 2019–2020 event, the polluted air mass described here had a clearly elevated water vapour content: between 2.5 and 5 times greater than that in the surrounding atmosphere. We describe the evolution of the polluted air mass, showing that it rose to an altitude of about 24 km (31 hPa) and divided into several identifiable parts. In addition to CO and H2O, we observe enhanced amounts of HCN, CH3CN, CH3Cl and CH3OH with mixing ratios in the range to be expected from a variety of measurements in other biomass burning plumes. We use back trajectories and plume-dispersion modelling to demonstrate that the pollutants observed by MLS originated in the British Columbia fires, the likeliest source being at 53.2∘ N, 121.8∘ W at 05:20 UTC on 13 August 2017.

Seismic Response Control of Elevated Water Tank using Base Isolation: A Review

Earthquake events are not something which can be avoidable. The Indian subcontinent has a background marked by devasting quakes. Quakes are generally caused when the stone underground out of nowhere breaks along an issue. Ground shake is caused by seismic waves due to sudden release of energy. The Centre of earthquake vibration is known as epicentre. Due to earthquake millions of lives are lost which can never be affordable. Most of the structures are subjected to vibrations; it causes destruction of country’s infrastructure. In the recent earthquakes many well designed concrete structures have been severely damaged or collapsed. To protect structures from response reduction of structures and important harm under such serious earthquakes has become a vital theme in structural engineering. In this investigation, we evaluated seismic performance of staging system of elevated water storage tank with or without Base Isolation by using SAP2000. From this examination the powers following up on elevated water tank because of seismic powers are determined for zone IV.

Seismic Analysis of Circular Elevated Water Tank Designed by Indian Standard and European Standard Code

Elevated water tank is used for storage of water which is used for distribution to the public at certain pressure head. In high seismic zones the safety of water tank becomes point of great concern which in case of failure becomes very hazardous for public because of deficiency of water for public use and difficulty in putting fire away caused by earthquake. The water tank must be designed as much strong so that it can perform during and after earthquake without failing. The aim of this study is to design the elevated water tank as per Indian standard code and European standard code on ETABS software. In this study an elevated circular water tank of 35 m3 capacity is being designed in seismic zone III as per IS code and spectrum zone II as per Euro code for hard soil, medium soil and soft soil conditions. During analysis of tank the values of base moment, base shear, storey displacement and storey drift is being obtained and compared in both seismic zones for hard soil, medium soil and soft soil. Keywords: base shear, base moment, ETABS, elevated water tank.