The climates of Earth's next supercontinent: effects of tectonics, rotation rate, and insolation

Author(s):  
Michael Way ◽  
Hannah Davies ◽  
Joao Duarte ◽  
Mattias Green

<div>We investigate two possible deep future Earth climate scenarios using a 3-D GCM [1], 200 and 250 million years into the future when the next supercontinent phase is expect to take place. We use knowledge of the evolution of plate tectonics, solar luminosity, and rotation rate over this time period.  In one scenario, a supercontinent forms at low latitudes. In the other scenario it forms at high northerly latitudes with an Antarctic subcontinent remaining at the south pole.  The climates differences between these two scenarios are dramatic, with differences in mean surface temperatures approaching 4 degrees. The fractional habitability (where mean surface temperatures are between 0<T<100C year round) on land surfaces (as opposed to the ocean) is shown to differ up to 40% between the two simulations. We believe these demonstrate that the community needs to consider alternative boundary conditions when simulating Earth-like exoplanetary climates.</div><div>[1] Way et al. 2017, ApJS, 231, 21.</div>

2019 ◽  
Vol 14 (2) ◽  
Author(s):  
Kjell Hausken ◽  
Mthuli Ncube

We consider revolutions and civil war involving an incumbent, a challenger, and the population. Revolutions are classified into eight outcomes. In four outcomes incumbent repression occurs (viewed as providing sub-threshold benefits such as public goods to the population). Accommodation occurs in the other four outcomes (benefits provision above a threshold). The incumbent and challenger fight each other. The incumbent may win and retain power or else lose, thereby causing standoff or coalition. In a standoff, which is costly, no one backs down and uncertainty exists about who is in power. In a coalition, which is less costly, the incumbent and challenger cooperate, compromise, and negotiate their differences. If the population successfully revolts against the incumbent, the challenger replaces the incumbent. Eighty-seven revolutions during 1961–2011, including the recent Arab spring revolutions, are classified into the eight outcomes. When repressive, the incumbent loses 46 revolutions, remains in power through 21 revolutions, and builds a coalition after 12 revolutions. When accommodative, the incumbent loses seven revolutions and builds a coalition after one revolution. The 87 revolutions are classified across geographic regions and by time-period.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Manfred Berres ◽  
Andreas U. Monsch ◽  
René Spiegel

Abstract Background The Placebo Group Simulation Approach (PGSA) aims at partially replacing randomized placebo-controlled trials (RPCTs), making use of data from historical control groups in order to decrease the needed number of study participants exposed to lengthy placebo treatment. PGSA algorithms to create virtual control groups were originally derived from mild cognitive impairment (MCI) data of the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database. To produce more generalizable algorithms, we aimed to compile five different MCI databases in a heuristic manner to create a “standard control algorithm” for use in future clinical trials. Methods We compared data from two North American cohort studies (n=395 and 4328, respectively), one company-sponsored international clinical drug trial (n=831) and two convenience patient samples, one from Germany (n=726), and one from Switzerland (n=1558). Results Despite differences between the five MCI samples regarding inclusion and exclusion criteria, their baseline demographic and cognitive performance data varied less than expected. However, the five samples differed markedly with regard to their subsequent cognitive performance and clinical development: (1) MCI patients from the drug trial did not deteriorate on verbal fluency over 3 years, whereas patients in the other samples did; (2) relatively few patients from the drug trial progressed from MCI to dementia (about 10% after 4 years), in contrast to the other four samples with progression rates over 30%. Conclusion Conventional MCI criteria were insufficient to allow for the creation of well-defined and internationally comparable samples of MCI patients. More recently published criteria for MCI or “MCI due to AD” are unlikely to remedy this situation. The Alzheimer scientific community needs to agree on a standard set of neuropsychological tests including appropriate selection criteria to make MCI a scientifically more useful concept. Patient data from different sources would then be comparable, and the scientific merits of algorithm-based study designs such as the PGSA could be properly assessed.


2003 ◽  
Vol 83 (1) ◽  
pp. 7-14 ◽  
Author(s):  
Slavoljub Dragicevic ◽  
Predrag Manojlovic ◽  
Sanja Mustafic

Based on the research of the chemical erosion intensity in the upper course of Tamnava, the appearance of its negative value has been found. Further researches, that enclose the lower course, confirmed this fact. This research opened the important question about the causes of this phenomena. Analytical method eliminated all expected causes and led to conclusion that the reason for this should be found by using the more precise research of the mineralisation of the precipitations. It was necessary to continue the measurings of the precipitation mineralisation in the greater number of locations and in the wider time period, as well as in the different meteorological conditions, and after that to establish the subordination between the amount of precipitations and the entered TDS. Only after these additive researches we could be able to find out the relation between ''entry'' and ''exit'' and to find out the intensity of the chemical erosion in this, and in the other river basins. For now, we are able only to find out the carrying of TDS, as well as the reduction of the chemical evacuation for the non - carbonated part of the basin (corrected value).


2019 ◽  
Author(s):  
Lewis Robert Anderson ◽  
Christiaan Willem Simon Monden ◽  
Erzsebet Bukodi

Individuals exposed to both job loss and marital dissolution are likely to be highly disadvantaged, having experienced stresses and losses in the two primary domains of life. Moreover, recent literature finds that exposure to one event tends to increase risk of the other. However, next to nothing is known about the size or composition – or changes therein – of the divorced/separated and unemployed (DSU) subpopulation. Using large, nationally representative, repeated cross-sectional datasets extending back to 1984, we aim to fill this gap for the UK. We give a descriptive account of the prevalence and social distribution of DSU, and of the cross-sectional association between its two component states: among which groups, by education and gender, does being either divorced/separated or unemployed most strongly imply a heightened risk of also being the other, and how has this changed over time? We find stable and strong educational inequality in DSU, while the gender gap has narrowed and recently closed. The association between the two states is stronger among men; has weakened strikingly over the time period we consider, for both men and, especially, women; and is educationally stratified among men but not women. Contrary to expectations, higher-educated men in one of the two states are most likely to also be in the other. Possible explanations and further questions are discussed. In particular, we highlight the possibility that over this time period the divorced/separated have become more like the general population, rather than a negatively selected subgroup among whom unemployment is a particular risk.


2017 ◽  
Vol 1 (16) ◽  
Author(s):  
Neđo Đurić

Railway route from entity border to Maglaj is on corridor V of railways that connects Adriatic seawith European Union countries. More precisely, it is on the railway Samac – Sarajevo that was builtduring the fifties. From Doboj to Zenica exist two tracks, one built in 1947. and the other thirty yearslater. In time, the railway worn out, since it was not maintained properly during its exploitation, soallowed train speed is 40 km/h. Reconstruction of railway had previously started on sections with aimto achieve the level of train speed to 120 km/h.Terrain research in order to overview quality of material on which the railway is laid, and immediateenvironment that has effect on railway route, were conducted by sections, from which section km103+500 – Maglaj is one of the most important considering characteristics of the terrain on which theroute passes. Research along railway route were conducted by using research trial pits from both sidesand in between tracks, to depth of entry in basic soil. Depth of research works is different for old andnew track, considering the way of construction in time period of 30 years. Beyond narrow corridor ofrailway route research of characteristics of the terrain were not conducted, because of inability toaccess due to mining. Results of terrain and laboratory tests showed geotechnical characteristics ofmaterial, based on which were given quality improvement measures for deposited materials, and basefor reconstruction of railway.


2020 ◽  
Vol 8 (2) ◽  
pp. 383
Author(s):  
Mukhaila Iryani ◽  
Yusnita Yusnita ◽  
Dwi Hapsoro ◽  
Kukuh Setiawan ◽  
Agus Karyanto

Hybrid moth orchid (genus Phalaenopsis) is one of the most popular ornamentals in Indonesia. It has beautiful and long-lasting flowers, but cultivating this orchid is still become a challenging issues due to the need of specific condition to grow and long time period to re-blooming. Plant growth regulators (PGR) (i.e. Benzyladenine (BA)) has been widely documented as a flower-inducing substance in several orchids. However, the optimal concentration and its mechanism in inducing flower-stalk bud and re-blooming is still unclear. This research aimed to study the effects of BA application in the form of lanolin paste on hybrid Phalaenopsis flower-stalk buds. We conducted this study using completely randomized design with four replications at the greenhouse laboratory Faculty of Agriculture University of Lampung on August to December 2018. We divided the orchid into 5 group of BA concentration (0, 1000, 1500, 3000, or 6000 ppm). The sheath of the fourth or fifth buds of the flowers were carefully opened, then it smeared with BA. The percentage of bud break into flower spike or keiki, length of shoots or spike and number of open flowers were recorded until 10 weeks of observation. The results showed that, neither of the buds under the control treatment (without BA), 1000 ppm nor 1500 ppm BA broke and grew into keiki or spike. On the other hand, application of BA at 3000 ppm or 6000 ppm successfully induced 100% flower spikes on the buds treated. No keiki was formed in all buds treated. In addition, treatment of the buds with 6000 ppm BA produced longer flower spikes as well as more open flowers. We conclude that the application of BA (minimal 3000 ppm) successfully induced flower spike of  hybrid Phalaenopsis.


Author(s):  
Maya Bielinski

The art manifesto, a written political, social, and artistic proclamation of an artistic movement, surged in popularity among avant‐garde art groups in the first half of the twentieth century. Many of the manifestos featured declarations for the synthesis of art and life as well as a call for social and political power for artists of both 'high' and 'low' art forms. Concurrently, new artistic interpretations of the humble teapot became suddenly ubiquitous. This inquiry explores how the teapot emerged as a dominant symbol for the goals of Modern Art movements, and includes an analysis of the teapot's socio‐political history, its ambiguous status between high and low art, and its role in the commercial sphere. By examining the teapots of Suprematism's Kazimir Malevich, Constructivism's Mariane Brandt,and Surrealism's Meret Oppenheim, this presentation will track ideas of functionality, the teapot as symbol, and aesthetics from 1923 to 1936. This small window in time offers an analysis of the extraordinary developments in teapots, and perhaps a glimpse of the paralleled momentum that occurred more generally in design, architecture, and the other arts in this time period.


2021 ◽  
Author(s):  
Konstantin Gregor ◽  
Thomas Knoke ◽  
Andreas Krause ◽  
Mats Lindeskog ◽  
Anja Rammig

<p>Forests are considered a major player in climate change mitigation since they influence local and global climate through biogeochemical and biogeophysical feedbacks. However, they are themselves vulnerable to future environmental changes. Thus, forest management needs to focus on both mitigation and adaptation. The special challenge is that decisions on management strategies must be taken today while still a broad range of emission pathways is possible, and a good decision regarding one assumed pathway might turn out to be a bad decision when a different one materializes.</p><p>With our study we try to aid this decision-making process by finding management portfolios that provide relevant ecosystem functions such as local and global climate regulation, water availability, flood protection, and timber production for a wide range of future climate scenarios. To simulate according ecosystem processes and functions, we run the dynamic vegetation model LPJ-GUESS for the most relevant forest types across Europe for four different RCPs and five different management options. We analyze our simulation outputs using robust optimization techniques to determine optimal forest management portfolios for each 0.5° grid cell in Europe that ensure a balanced provision of all considered ecosystem functions in the future under any of the four RCPs.</p><p>Generally, our simulations and optimizations show that diversified management portfolios are most suitable to provide the set of considered ecosystem functions in all climate scenarios everywhere in Europe. While the portfolios show different compositions in different regions, they are quite similar in adjacent grid cells. The suggested future forest composition in Europe tends to be fairly close to present day values except for Northern Europe where a much higher proportion of deciduous types is proposed.</p><p>Management as high forest (trees emerging from seeds) remains the most important form of management. The proposed share of coppice management is much higher in Central and Northern Europe (~20%) than in Southern Europe, where its disadvantages (e.g., high water consumption and its non-suitability to provide long-lived wood products) are more pronounced.</p><p>A succession of ~30% of managed forest to natural forest is proposed by the optimization as it provides highest carbon storage and surface roughness values. However, this infeasibly high share is reduced if the provision of wood harvest is valued higher in the optimization compared to the other ecosystem functions.</p><p>Current public focus on forests lies often on their potential for carbon sequestration, but future forest management must also address the other services that they provide. This work gives insights on how this may be done.</p>


Author(s):  
David Beerling

By arriving at the South Pole on 14 December 1911, the Norwegian explorer Roald Amundsen (1872–1928) reached his destination over a month ahead of the British effort led by Captain Robert Falcon Scott (1868–1912). As Scott’s party approached the South Pole on 17 January 1912, they were devastated to see from afar the Norwegian’s black flag. On arrival, they discovered the remains of his camp with ski and sledge tracks, and numerous dog footprints. Amundsen, it turned out, had used dogs and diversionary tactics to secure victory while the British team had man-hauled their sledges. These differences were not lost on The Times in London, which marked the achievement with muted praise, declaring it ‘not quite in accordance with the spirit of fair and open competition which hitherto marked Antarctic exploration’. Exhausted, Scott and his men spent time the following day making scientific observations around the Pole, erected ‘our poor slighted Union Jack’, and photographed themselves in front of it (Plate 11). Lieutenant Bowers took the picture by pulling a string to activate the shutter. It is perhaps the most well known, and at the same time the saddest picture, of the entire expedition—a poignant image of the doomed party, all of whom look utterly fed up as if somehow sensing the fate awaiting them. The cold weather, icy wind, and dismal circumstances led Scott to acerbically remark in his diary: ‘Great god! This is an awful place and terrible enough to have laboured to it without the reward of priority.’ By this time, the party had been hauling their sledges for weeks, and all the men were suffering from dehydration, owing to fatigue and altitude sickness from being on the Antarctic plateau that sits nearly 3000m above sea level. Three of them, Captain Oates, Seaman Evans, and Bowers, were badly afflicted with frostbitten noses and cheeks. Ahead lay the return leg, made all the more unbearable by the crippling psychological blow of knowing they had been second to the Pole. After a gruelling 21-day trek in bitterly cold summit winds, the team reached their first cache of food and fuel, covering the distance six days faster than it had taken them to do the leg in the other direction.


Author(s):  
Glennda Chui

In August 1999, I stood in the ruins of a collapsed apartment building near Izmit, Turkey—one of 60,000 buildings destroyed in 40 seconds by the most powerful earthquake to strike a major city in nearly a century. It was a modern building surrounded by trees and greenery. A couch and a table stood intact in a room bright with potted flowers, now open to the air. A woman's coat had been carefully draped over the remains of a wall. As the stench of death rose around us, I wondered if the coat's owner was buried in the rubble beneath my feet. I was sent to Turkey to chase the science—to bring home lessons for readers who live near a strikingly similar fault system in California. But as I surveyed the damage with a team of scientists and engineers, there was no separating the science from the politics. Covered with a fine film of sweat mixed with dust from crumbled buildings and lime that had been scattered to prevent the spread of disease, we saw firsthand how corruption and greed had conspired with the forces of nature to kill more than 17,000 people. Some buildings were constructed right on the North Anatolian Fault. Its mole-like tracks plowed through barracks that had collapsed on 120 military officers, a highway overpass that fell on a bus, a bridge whose failure cut off access and aid to four villages. Researchers found concrete that was crumbly with seashells, chunks of Styrofoam where reinforcing metal bars should have been. Yet some well-reinforced buildings nicked or even pierced by the fault came through just fine, including an apartment building that moved 10 feet and had its front steps sliced off. Another home was cut in two; half collapsed, the other survived with windows intact. “How the hell?” marveled one engineer. “There's no way that building should stand in an earthquake.” That blend of science, politics, and human nature is just part of what makes earth science so compelling. It goes far beyond the academics of geology and plate tectonics to embrace earthquakes, floods, hurricanes, volcanoes, landslides—natural hazards that affect thousands of people and change the course of civilization.


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