1,161 research outputs found
Do Proto-Jovian Planets Drive Outflows?
We discuss the possibility that gaseous giant planets drive strong outflows
during early phases of their formation. We consider the range of parameters
appropriate for magneto-centrifugally driven stellar and disk outflow models
and find that if the proto-Jovian planet or accretion disk had a magnetic field
of >~ 10 Gauss and moderate mass inflow rates through the disk of less than
10^-7 M_J/yr that it is possible to drive an outflow. Estimates based both on
scaling from empirical laws observed in proto-stellar outflows and the
magneto-centrigugal disk and stellar+disk wind models suggest that winds with
mass outflow rates of 10^-8 M_J/yr and velocities of order ~ 20 km/s could be
driven from proto-Jovian planets. Prospects for detection and some implications
for the formation of the solar system are briefly discussed.Comment: AAS Latex, accepted for Ap
Compared to conventional, ecological intensive management promotes beneficial proteolytic soil microbial communities for agro-ecosystem functioning under climate change-induced rain regimes
Projected climate change and rainfall variability will affect soil microbial communities, biogeochemical cycling and agriculture. Nitrogen (N) is the most limiting nutrient in agroecosystems and its cycling and availability is highly dependent on microbial driven processes. In agroecosystems, hydrolysis of organic nitrogen (N) is an important step in controlling soil N availability. We analyzed the effect of management (ecological intensive vs. conventional intensive) on N-cycling processes and involved microbial communities under climate change-induced rain regimes. Terrestrial model ecosystems originating from agroecosystems across Europe were subjected to four different rain regimes for 263 days. Using structural equation modelling we identified direct impacts of rain regimes on N-cycling processes, whereas N-related microbial communities were more resistant. In addition to rain regimes, management indirectly affected N-cycling processes via modifications of N-related microbial community composition. Ecological intensive management promoted a beneficial N-related microbial community composition involved in N-cycling processes under climate change-induced rain regimes. Exploratory analyses identified phosphorus-associated litter properties as possible drivers for the observed management effects on N-related microbial community composition. This work provides novel insights into mechanisms controlling agro-ecosystem functioning under climate change
Majoritarian Blotto contests with asymmetric battlefields: an experiment on apex games
We investigate a version of the classic Colonel Blotto game in which individual battlefields may have different values. Two players allocate a fixed discrete budget across battlefields. Each battlefield is won by the player who allocates the most to that battlefield. The player who wins the battlefields with highest total value receives a constant winner payoff, while the other player receives a constant loser payoff. We focus on apex games, in which there is one large and several small battlefields. A player wins if he wins the large and any one small battlefield, or all the small battlefields. For each of the games we study, we compute an equilibrium and we show that certain properties of equilibrium play are the same in any equilibrium. In particular, the expected share of the budget allocated to the large battlefield exceeds its value relative to the total value of all battlefields, and with a high probability (exceeding 90% in our treatments) resources are spread over more battlefields than are needed to win the game. In a laboratory experiment, we find that strategies that spread resources widely are played frequently, consistent with equilibrium predictions. In the treatment where the asymmetry between battlefields is strongest, we also find that the large battlefield receives on average more than a proportional share of resources. In a control treatment, all battlefields have the same value and our findings are consistent with previous experimental findings on Colonel Blotto games
Soft quantification in statistical relational learning
We present a new statistical relational learning (SRL) framework that supports reasoning with soft quantifiers, such as "most" and "a few." We define the syntax and the semantics of this language, which we call , and present a most probable explanation inference algorithm for it. To the best of our knowledge, is the first SRL framework that combines soft quantifiers with first-order logic rules for modelling uncertain relational data. Our experimental results for two real-world applications, link prediction in social trust networks and user profiling in social networks, demonstrate that the use of soft quantifiers not only allows for a natural and intuitive formulation of domain knowledge, but also improves inference accuracy
Area minimizing discs in metric spaces
We solve the classical problem of Plateau in the setting of proper metric spaces. Precisely, we prove that among all disc-type surfaces with prescribed Jordan boundary in a proper metric space there exists an area minimizing disc which moreover has a quasi-conformal parametrization. If the space supports a local quadratic isoperimetric inequality for curves we prove that such a solution is locally Hölder continuous in the interior and continuous up to the boundary. Our results generalize corresponding results of Douglas Radò and Morrey from the setting of Euclidean space and Riemannian manifolds to that of proper metric spaces
Seasonal effects on reconciliation in Macaca Fuscata Yakui
Dietary composition may have profound effects on the activity budgets, levelof food competition, and social behavior of a species. Similarly, in seasonally breeding species, the mating season is a period in which competition for mating partners increases, affecting amicable social interactions among group members. We analyzed the importance of the mating season and of seasonal variations in dietary composition and food competition on econciliation
in wild female Japanese macaques (Macaca fuscata yakui) on Yakushima Island, Japan. Yakushima macaques are appropriate subjects because they are seasonal breeders and their dietary composition significantly changes among the seasons. Though large differences occurred between the summer months and the winter and early spring months in activity budgets and the consumption of the main food sources, i.e., fruits, seeds, and leaves, the level
of food competition and conciliatory tendency remained unaffected. Conversely,conciliatory tendency is significantly lower during the mating season than in the nonmating season. Moreover, conciliatory tendency is lower when 1 or both female opponents is in estrous than when they are not. Thus the mating season has profound effects on reconciliation, whereas seasonal changes in activity budgets and dietary composition do not. The detrimental effects of the mating season on female social relationships and reconciliation may be due to the importance of female competition for access to male partners in multimale, multifemale societies
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Costing conservation: an expert appraisal of the pollinator habitat benefits of England’s entry level stewardship
Pollination services provided by insects play a key role in English crop production and wider ecology. Despite growing evidence of the negative effects of habitat loss on pollinator populations, limited policy support is available to reverse this pressure. One measure that may provide beneficial habitat to pollinators is England’s entry level stewardship agri-environment scheme. This study uses a novel expert survey to develop weights for a range of models which adjust the balance of Entry Level Stewardship options within the current area of spending. The annual costs of establishing and maintaining these option compositions were estimated at £59.3–£12.4 M above current expenditure. Although this produced substantial reduction in private cost:benefit ratios, the benefits of the scheme to pollinator habitat rose by 7–140 %; significantly increasing the public cost:benefit ratio. This study demonstrates that the scheme has significant untapped potential to provide good quality habitat for pollinators across England, even within existing expenditure. The findings should open debate on the costs and benefits of specific entry level stewardship management options and how these can be enhanced to benefit both participants and biodiversity more equitably
Middle Permian U-Pb Zircon Ages of the Glacial Deposits of the Atkan Formation, Ayan-Yuryakh Anticlinorium, Magadan Province, NE Russia: Their Significance for Global Climatic Interpretations
The Atkan Formation in the Ayan-Yuryakh anticlinorium, Magadan province, northeastern Russia, is of great interest because of the occurrence of deposits of apparent “dropstones” and “ice rafted debris” that have been previously interpreted as glacial. Two high-precision U-Pb zircon ages, one for an intercalated volcanic tuff (262.5 ± 0.2 Ma) and the other for a boulder clast (269.8 ± 0.1 Ma) within a diamictite of the Atkan Formation, constrain the age of the Atkan Formation as Guadalupian (middle Permian). Sedimentologic study of the Atkan Formation casts doubt on the glacial nature of the diamictites. Deposition of rocks of the Atkan Formation temporally correlates with the Capitanian interglacial event in the southern hemisphere that recently was calibrated with high precision CA-TIMS. The previously proposed climate proxy record based upon warm-water foraminifera, which corresponds closely to global climate fluctuations, is compared with the glacial record of eastern Australia and indicates that the Capitanian was a time of globally warm climate. The sedimentology of Atkan Formation, the record of diversification of both fusulinids and rugosa corals, global sea-water temperature, and sea-level fluctuations agree well with high latitude paleoclimate records in northeastern Russia and eastern Australia. Major components of the Atkan Formation, the volcanic rocks, are syngenetic with the sedimentation process. The volcanic activity in the nearby regions during middle-late Permian was quite extensive
Demography and Life Histories of Sympatric Patas Monkeys, Erythrocebus patas, and Vervets, Cercopithecus aethiops, in Laikipia, Kenya
Mortality patterns are thought to be strong selective forces on life history traits, with high adult mortality and low immature mortality favoring early and rapid reproduction. Patas monkeys (Erythrocebus patas) have the highest potential rates of population increase for their body size of any haplorhine primate because they reproduce both earlier and more often. We report here 10 yr of comparative demographic data on a population of patas monkeys and a sympatric population of vervet monkeys (Cercopithecus aethiops), a closely related species differing in aspects of social system, ecology, and life history. The data reveal that 1) adult female patas monkeys have significantly higher mortality than adult female vervets; 2) infant mortality in patas monkeys is relatively low compared to the norm for mammals because it is not significantly different from that of adult female patas monkeys; and 3) infant mortality is significantly higher than adult female mortality in vervets. For both species, much of the mortality could be attributed to predation. An epidemic illness was also a major contributor to the mortality of adult female patas monkeys whereas chronic exposure to pathogens in a cold and damp microenvironment may have contributed to the mortality of infant vervets. Both populations experienced large fluctuations during the study period. Our results support the prediction from demographic models of life history evolution that high adult mortality relative to immature mortality selects for early maturation
Detrital zircon geochronology and sedimentology of glaciogenic strata of the middle Carboniferous San Eduardo Formation, Calingasta-Uspallata Basin, NW Argentina
The Calingasta-Uspallata Basin preserves a near continuous sequence of glaciomarine deposition from themiddle to late Carboniferous, represented by five separate formations. Correlation between theseformations have been achieved using index marine invertebrates, which also provides some implicationsfor max-depositional ages. However, no isotopic dating analyses have been sought in this basin to furtherconstrain the age of deposition or provide a source of provenance for sediments. The San Eduardoformation near the El Leoncito Astronomical Complex, San Juan Province, Argentina, was deposited withinthe Calingasta?Uspallata Basin on the western margin of the proto-Precordillera during the lateMississippian to early Pennsylvanian. This succession preserves a complete sequence of proximalglaciomarine, nearshore, and fluvial systems deposited at the beginning of the late Paleozoic ice age.Samples were collected from various stages throughout the sequence for detrital zircon U-Pbgeochronology to determine sediment provenance as a way of isolating different glacier sources. Resultsindicate multiple stages of glaciation, with at least three distinct source areas. The lowermost stageincludes locally sourced basement and recycled underlying Silurian, represented by similar Famatinian(500-460 Ma) and Sunsas peaks (1450-1000 Ma) peaks, with the Sunsas source likely originating from theWestern Sierras Pampeans, which would represent a breaching of the proto-Precordillera from the east.The middle stage shows a population distinct unto itself, with a peak during the Mississippian (330-360Ma). A volcanic island arc was situated along the Andean margin during the late Paleozoic, likely resultingin the influx of Carboniferous aged volcanic sediments. The lower most stage shows relations based on K-Sresults to formations within the Paganzo basin to the northeast, likely serving as the outwash of thesedistant glaciers through braided fluvial systems. This study will expand upon current chronologicknowledge within the Calingasta-Uspallata basin and will be supported by sandstone petrology andmineralogic composition, pebble counts and composition of dropstones.Fil: Malone, John E.. University of Wisconsin; Estados UnidosFil: Isbell, John L.. University of Wisconsin; Estados UnidosFil: Bowles, Julie A.. University of Wisconsin; Estados UnidosFil: Pagani, María Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Taboada, Arturo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagóica. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel. Centro de Investigación Esquel de Montaña y Estepa Patagónica; ArgentinaGSA 2019PhoenixEstados UnidosGeological Society of Americ
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