Lee Y.-N.,Korea Institute of Geoscience and Mineral Resources |
Barsbold R.,Mongolian Academy of science |
Currie P.J.,University of Alberta |
Kobayashi Y.,Hokkaido University |
And 4 more authors.
Nature | Year: 2014
The holotype of Deinocheirus mirificus was collected by the 1965 Polish-Mongolian Palaeontological Expedition at Altan Uul III in the southern Gobi of Mongolia. Because the holotype consists mostly of giant forelimbs (2.4 m in length) with scapulocoracoids, for almost 50 years Deinocheirus has remained one of the most mysterious dinosaurs. The mosaic of ornithomimosaur and non-ornithomimosaur characters in the holotype has made it difficult to resolve the phylogenetic status of Deinocheirus. Here we describe two new specimens of Deinocheirus that were discovered in the Nemegt Formation of Altan Uul IV in 2006 and Bugiin Tsav in 2009. The Bugiin Tsav specimen (MPC-D 100/127) includes a left forelimb clearly identifiable as Deinocheirus and is 6% longer than the holotype. The Altan Uul IV specimen (MPC-D 100/128) is approximately 74% the size of MPC-D 100/127. Cladistic analysis indicates that Deinocheirus is the largest member of the Ornithomimosauria; however, it has many unique skeletal features unknown in other ornithomimosaurs, indicating that Deinocheirus was a heavily built, non-cursorial animal with an elongate snout, a deep jaw, tall neural spines, a pygostyle, a U-shaped furcula, an expanded pelvis for strong muscle attachments, a relatively short hind limb and broad-tipped pedal unguals. Ecomorphological features in the skull, more than a thousand gastroliths, and stomach contents (fish remains) suggest that Deinocheirus was a megaomnivore that lived in mesic environments. © 2014 Macmillan Publishers Limited. All rights reserved.
Bishop C.M.,Bangor University |
Spivey R.J.,Bangor University |
Hawkes L.A.,Bangor University |
Hawkes L.A.,University of Exeter |
And 10 more authors.
Science | Year: 2015
The physiological and biomechanical requirements of flight at high altitude have been the subject of much interest. Here, we uncover a steep relation between heart rate and wingbeat frequency (raised to the exponent 3.5) and estimated metabolic power and wingbeat frequency (exponent 7) of migratory bar-headed geese. Flight costs increase more rapidly than anticipated as air density declines, which overturns prevailing expectations that this species should maintain high-altitude flight when traversing the Himalayas. Instead, a "roller coaster" strategy, of tracking the underlying terrain and discarding large altitude gains only to recoup them later in the flight with occasional benefits from orographic lift, is shown to be energetically advantageous for flights over the Himalayas. © 2015, American Association for the Advancement of Science. All rights reserved.
Enkhbat T.,Mongolian Academy of science |
Enkhbat T.,National Taiwan University
Journal of High Energy Physics | Year: 2014
The presence of colored particles can affect both the single and the pair Higgs productions substantially. For scalar particles, this happens if their portal couplings to the Standard Model Higgs are large and their masses are not too high. In the present work these processes are studied in the case of several leptoquarks which may appear in many beyond Standard Model theories. It is found that the constraints on the portal couplings from the single Higgs production and the decays to various channels measured by the LHC experiments still allow increased Higgs pair production rate. For the masses in the range from 180 GeV to 300 GeV, depending on the strength of such portal couplings, the Higgs pair production may reach an order to several hundred in magnitude larger rate than the Standard Model case for the 8 TeV run. Therefore, combined with the on going searches for leptoquarks by both the CMS and ATLAS, this is one of the possible scenarios to be probed directly by the current data. The current study demonstrates that if colored scalars modify scalar potentials through portal couplings, which has been studied for variety of motivations such as playing a potentially important role in electroweak phase transition, composite models or radiative neutrino masses, this fact may appear as the modified Higgs pair production. © 2014 The Author(s).
Haba N.,The University of Shimane |
Kaneta K.,University of Tokyo |
Mimura Y.,National Taiwan University |
Enkhbat T.,National Taiwan University |
Enkhbat T.,Mongolian Academy of science
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2014
Higgs cubic coupling plays a crucial role in probing an origin of electroweak symmetry breaking. It is expected that the cubic coupling is measured by Higgs pair production at the LHC and ILC, and the deviations from the standard model can be extracted from the Higgs pair production process, and those can give us a hint of new physics beyond the standard model. We consider a general potential that achieves the suitable electroweak symmetry breaking. As one of the interesting models, we suggest a nonperturbative Higgs model in which a runaway type of potential is used. In the model, the cross sections of pair production at the LHC are enlarged compared to the standard model. We also study the Higgs pair production induced by a noncanonical kinetic term of Higgs fields which will be important for searching the pair production at the ILC. © 2014 American Physical Society.
Battogtokh D.,Mongolian Academy of science |
Battogtokh D.,University of Virginia
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2015
We report a mechanism of pattern formation in growing bistable systems coupled indirectly. A modified Fujita et al. model is studied as an example of a reaction-diffusion system of nondiffusive activator and inhibitor molecules immersed in the medium of a fast diffusive agent. Here we show that, as the system grows, a new domain nucleates spontaneously in the area where the local level of the agent becomes critical. Newly nucleated domains are stable and the pattern formation is different from Turing's mechanism in monostable systems. Domains are spatially confined by the agent even if the activator and inhibitor molecules diffuse. With the spatial extension of the system, a larger domain may undergo a wave number instability, and the concentrations of active molecules within the neighboring elements of a domain can become sharply different. The mechanism reported in this work could be generic for pattern formation systems involving multistability, growth, and indirect coupling. © 2015 American Physical Society.
Free C.M.,Rutgers University |
Jensen O.P.,Rutgers University |
Mendsaikhan B.,Mongolian Academy of science
PLoS ONE | Year: 2015
Illegal harvest is recognized as a widespread problem in natural resource management. The use of multiple methods for quantifying illegal harvest has been widely recommended yet infrequently applied.We used a mixed-method approach to evaluate the extent, character, and motivations of illegal gillnet fishing in Lake Hovsgol National Park, Mongolia and its impact on the lake's fish populations, especially that of the endangered endemic Hovsgol grayling (Thymallus nigrescens). Surveys for derelict fishing gear indicate that gillnet fishing is widespread and increasing and that fishers generally use 3-4 cm mesh gillnet. Interviews with resident herders and park rangers suggest that many residents fish for subsistence during the spring grayling spawning migration and that some residents fish commercially year-round. Interviewed herders and rangers generally agree that fish population sizes are decreasing but are divided on the causes and solutions. Biological monitoring indicates that the gillnet mesh sizes used by fishers efficiently target Hovsgol grayling. Of the five species sampled in the monitoring program, only burbot (Lota lota) showed a significant decrease in population abundance from 2009-2013. However, grayling, burbot, and roach (Rutilus rutilus) all showed significant declines in average body size, suggesting a negative fishing impact. Data-poor stock assessment methods suggest that the fishing effort equivalent to each resident family fishing 50-m of gillnet 11-15 nights per year would be sufficient to overexploit the grayling population. Results from the derelict fishing gear survey and interviews suggest that this level of effort is not implausible. Overall, we demonstrate the ability for a mixed-method approach to effectively describe an illegal fishery and suggest that these methods be used to assess illegal fishing and its impacts in other protected areas. © 2015 Free et al.This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Lkhagvadorj D.,Mongolian State University of Agriculture |
Hauck M.,University of Gottingen |
Dulamsuren C.,University of Gottingen |
Tsogtbaatar J.,Mongolian Academy of science
Journal of Arid Environments | Year: 2013
The population structure, educational level and the livelihoods of 82 households of pastoral nomads, the organization of livestock husbandry and its impact on the grassland and forest ecosystems of the Dayan high valley (>2000 m a.s.l.) in the Mongolian Altai, western Mongolia, were surveyed using interviews and secondary information from official sources. Changes following the transition from centrally planned (before 1990) to market economy were analyzed. Two thirds of the monthly mean income of ca. 310 USD per nomad household is cash (ca. 55 USD) or non-cash (ca. 165 USD) income from livestock husbandry. Cashmere sale accounts for 70% of the cash income from livestock husbandry, which has led to a strong increase of goat numbers after 1990. Forests are used for livestock grazing, fuel wood collection, logging, and fruit collection. Livestock breeding and the seasonal migration of the nomad households are no longer organized by the government. To avoid transportation costs, two thirds of the families have reduced their seasonal migrations. This trend was favored by rising temperatures and earlier snowmelt during the last few decades, but resulted in a shortage of fodder and intensified forest use. Therefore, the use of grasslands and forests in the Mongolian Altai is no longer considered to be sustainable. © 2012 Elsevier Ltd.
Fanti F.,University of Bologna |
Currie P.J.,University of Alberta |
Badamgarav D.,Mongolian Academy of science
PLoS ONE | Year: 2012
Two new specimens of the oviraptorid theropod Nemegtomaia barsboldi from the Nemegt Basin of southern Mongolia are described. Specimen MPC-D 107/15 was collected from the upper beds of the Baruungoyot Formation (Campanian-Maastrichtian), and is a nest of eggs with the skeleton of the assumed parent of Nemegtomaia on top in brooding position. Much of the skeleton was damaged by colonies of dermestid coleopterans prior to its complete burial. However, diagnostic characters are recovered from the parts preserved, including the skull, partial forelimbs (including the left hand), legs, and distal portions of both feet. Nemegtomaia represents the fourth known genus of oviraptorid for which individuals have been found on nests of eggs. The second new specimen, MPC-D 107/16, was collected a few kilometers to the east in basal deposits of the Nemegt Formation, and includes both hands and femora of a smaller Nemegtomaia individual. The two formations and their diverse fossil assemblages have been considered to represent sequential time periods and different environments, but data presented here indicate partial overlap across the Baruungoyot-Nemegt transition. All other known oviraptorids from Mongolia and China are known exclusively from xeric or semi-arid environments. However, this study documents that Nemegtomaia is found in both arid/aeolian (Baruungoyot Formation) and more humid/fluvial (Nemegt Formation) facies. © 2012 Fanti et al.
Arbour V.M.,University of Alberta |
Currie P.J.,University of Alberta |
Badamgarav D.,Mongolian Academy of science
Zoological Journal of the Linnean Society | Year: 2014
The discovery of a new ankylosaurid skull with some unusual features from the Baruungoyot Formation of Mongolia prompted a systematic review of ankylosaurid specimens from the Baruungoyot and Nemegt formations. Dyoplosaurus giganteus was found to possess no diagnostic features and is regarded as a nomen dubium. The holotype of Tarchia kielanae (previously synonymized with Tarchia gigantea) has one autapomorphy, an accessory postorbital ossification with surrounding furrow, and Tar.kielanae is here considered a valid species, making the combination Tar.gigantea unnecessary. An accessory postorbital ossification is also found in the holotype of Minotaurasaurus ramachandrani, and this species is here considered a junior synonym of Tar.kielanae. The newly described skull from the Baruungoyot Formation forms the holotype of a new genus and species, Zaraapelta nomadis gen. et sp. nov., diagnosed by unusual bilayered ornamentation on the squamosal horn and extensive postocular ornamentation. Two distinct tail club handle morphotypes are present in the Nemegt Formation and probably represent two different species. However, it is impossible to assign either tail club morphotype to the single valid species from the formation, Saichania chulsanensis, because of a lack of overlapping material. A revised phylogenetic analysis including newly identified characters found Zaraapelta nomadis to be most closely related to Tar.kielanae. © 2014 The Linnean Society of London.
Zhao L.,Chinese Academy of Sciences |
Wu Q.,Chinese Academy of Sciences |
Marchenko S.S.,University of Alaska Fairbanks |
Sharkhuu N.,Mongolian Academy of science
Permafrost and Periglacial Processes | Year: 2010
Permafrost in Central Asian is present in the Qinghai-Tibet Plateau in China, the Tien Shan Mountain regions in China, Kazakhstan and Kyrgyzstan, the Pamirs in Tajikistan, and in Mongolia. Monitoring of the ground thermal regime in these regions over the past several decades has shown that the permafrost has been undergoing significant changes caused by climate warming and increasing human activities. During the International Polar Year, measured mean annual ground temperature (MAGT) at a depth of 6 m ranged from -3.2°C to 0.2°C on the Qinghai-Tibet Plateau and the active-layer thickness (ALT) varied between 105 and 322 cm at different sites. Ground temperatures at the bottom of the active layer (TTOP) warmed on average by 0.06°C yr-1 over the past decade. In Mongolia, MAGT at 10-15 m depth increased by up to 0.02-0.03°C yr-1 in the Hovsgol Mountain region, but by 0.01-0.02°C yr-1 in the Hangai and Hentei Mountain regions. The increase in permafrost temperatures in the northern Tien Shan from 1974 to 2009 ranged from 0.3°C to 0.6°C At present measured permafrost temperatures vary from -0.5°C to -0.1°C. The ALT increased from 3.2 to 4 m in the 1970s to a maximum of 5.2 m between 1995 and 2009. © 2010 John Wiley & Sons, Ltd.