269 research outputs found
Territorial Behaviour of Kiang (\u3ci\u3eEquus kiang\u3c/i\u3e Moorcroft, 1841) in Ladakh (India)
The observations of kiang behavior were made in Navokar Valley northeast of Tso Kar Lake (Ladakh, India) between July 30 and November 22, 2001. In the breeding season (end of July until the end of August) adult kiang males kept not overlapping, protected territories (about 10 km2), and marked by single defecation and urination marks. There were adult females with and without offspring on the territories (up to 12 animals, including the male). The distance between male and females on the territories was usually hundred times bigger, then a distance between stallion and his harem in horses. Females with foals didn’t take part in mating, but stood on territories approximately until mid September, when foals became 1.5 - 2 months old. From this time adult females started to join in bigger groups and bachelor groups came down to the valley from the plateau. In October - November we registered groups of adult females with offspring (up to 37 animals), accompanied by one adult male; bachelor groups of different age males, including old ones (up to 25 animals) and groups of young (2 - 3 years old) females (up to 9 animals). The number of kiangs in Navokar Valley increased by two times in autumn in comparison with the breeding season and reached 78 animals. The maximal numbers of kiangs sighted in one day in the surrounding of Tso Kar was recorded in October (151 animals)
Numbers, Distribution and Social Structure of Kiang (\u3ci\u3eEquus kiang\u3c/i\u3e Moorcroft 1841) Population in the Southwestern Part of Tibet, China
In September - October 1998 we made an extensive survey in southwest Tibet to study numbers, distribution and social structure of the kiang population in this remote part of its range. Kiangs were sighted between 29º 40’ and 32º 50’ N, and 81º- 86º E. They preferred broad flat valleys with lakes at an altitude from 4,000 up to 5,000 m. Small kiang groups and solitary animals were sighted in Transhimalaya. There were no kiangs in Tsangpo (Brahmaputra) River valley, in the sand desert near Ali and in the Clay Mountains near Tsada. Seven old kiang corpses were found along the road, and five of them near Pryang. Main exterior measurements were taken from an adult male, shot by military personnel a day before we found it.
About 90% of all animals were concentrated on three territories. The density of the population on these territories ranged from 0.6 up to 4.2/km², but the average density was 0.15/km². The social structure of the population included solitary individuals, pairs and groups.
The kiang population on the studied territory (190,000 km²), which does not have any protection status, was estimated between 28,000-29,000 exemplars. This must represent a considerable part of the whole population of the Tibetan Plateau.
All three big kiang herds (from 91 up to 591) were found along the main road, and only one of them had natural protection in winter. The others two kiang herds are very vulnerable in winter, when snow did not allow them to run fast and they were easily shot from cars. The information about the exact location of kiang winter territories can be very useful for the correct planning of kiang protection in southwest Tibet
Kiangs (\u3ci\u3eEquus kiang\u3c/i\u3e, Moorcroft 1841) in Sikkim, India
Between the 5th and 10th of March 2001 we completed a 450 km route by car in Northern Sikkim. During the trip along the southern slopes of the Himalayas and Sikkim Plateau we didn’t see a single kiang. According to the local people and military personnel in Sikkim, kiangs are known only in the outer limits of the Sikkim Plateau, where wild animals have a possibility to migrate free over the Chinese-Indian border. In winter only small groups of kiang incidentally come to the Sikkim Plateau from South Tibet. But in May more of them come there and stay approximately until October-November, especially in the eastern part of the plateau near the lakes. The Sikkim Plateau is a breeding territory for kiangs, which spend winters in South Tibet. Local people and military personnel do not hunt or catch kiang on the Sikkim Plateau. Kiang migrations over the Chinese-Indian border are dependent on the movements of the nomadic yak herders of Sikkim, who spend winter on the plateau and go to the southern slopes of the Himalayas in spring. Nowhere in other parts of the great range of this species do kiangs breed at such an altitude (5,100 - 5,500 m above sea level). We suggest that this may be due to the small size of the southern kiang (Equus kiang polyodon). The best time for kiang surveys in Sikkim is usually the end of August to the beginning of September
Kiangs (\u3ci\u3eEquus kiang\u3c/i\u3e, Moorcroft 1841) in Sikkim, India
Between the 5th and 10th of March 2001 we completed a 450 km route by car in Northern Sikkim. During the trip along the southern slopes of the Himalayas and Sikkim Plateau we didn’t see a single kiang. According to the local people and military personnel in Sikkim, kiangs are known only in the outer limits of the Sikkim Plateau, where wild animals have a possibility to migrate free over the Chinese-Indian border. In winter only small groups of kiang incidentally come to the Sikkim Plateau from South Tibet. But in May more of them come there and stay approximately until October-November, especially in the eastern part of the plateau near the lakes. The Sikkim Plateau is a breeding territory for kiangs, which spend winters in South Tibet. Local people and military personnel do not hunt or catch kiang on the Sikkim Plateau. Kiang migrations over the Chinese-Indian border are dependent on the movements of the nomadic yak herders of Sikkim, who spend winter on the plateau and go to the southern slopes of the Himalayas in spring. Nowhere in other parts of the great range of this species do kiangs breed at such an altitude (5,100 - 5,500 m above sea level). We suggest that this may be due to the small size of the southern kiang (Equus kiang polyodon). The best time for kiang surveys in Sikkim is usually the end of August to the beginning of September
Modeling quark-hadron duality in polarization observables
We apply a model for the study of quark-hadron duality in inclusive electron
scattering to the calculation of spin observables. The model is based on
solving the Dirac equation numerically for a scalar confining linear potential
and a vector color Coulomb potential. We qualitatively reproduce the features
of quark-hadron duality for all potentials considered, and discuss the onset of
scaling and duality for the responses, spin structure functions, and
polarization asymmetries. Duality may be applied to gain access to kinematic
regions which are hard to access in deep inelastic scattering, namely for
, and we discuss which observables are most suitable for this
application of duality
Gauging the spectator equations
We show how to derive relativistic, unitary, gauge invariant, and charge
conserving three-dimensional scattering equations for a system of hadrons
interacting with an electromagnetic field. In the method proposed, the
spectator equations describing the strong interactions of the hadrons are
gauged using our recently introduced gauging of equations method. A key
ingredient in our model is the on-mass-shell particle propagator. We discuss
how to gauge this on-mass-shell propagator so that both the Ward-Takahashi and
Ward identities are satisfied. We then demonstrate our gauging procedure by
deriving the gauge-invariant three-dimensional expression for the deuteron
photodisintegration amplitude within the spectator approach.Comment: 17 pages, REVTeX, epsf, 1 Postscript figur
Two-nucleon knockout contributions to the C reaction in the dip and {}(1232) regions
The contributions from C and C to the
semi-exclusive C cross section have been calculated in an
unfactorized model for two-nucleon emission. We assume direct two-nucleon
knockout after virtual photon coupling with the two-body pion-exchange currents
in the target nucleus. Results are presented at several kinematical conditions
in the dip and (1232) regions. The calculated two-nucleon knockout
strength is observed to account for a large fraction of the measured
strength above the two-nucleon emission threshold.Comment: 12 Revtex pages, 4 postscript figures (available upon request),
University of Gent preprint SSF94-02-0
Scaling of Dirac Fermions and the WKB approximation
We discuss a new method for obtaining the WKB approximation to the Dirac
equation with a scalar potential and a time-like vector potential. We use the
WKB solutions to investigate the scaling behavior of a confining model for
quark-hadron duality. In this model, a light quark is bound to a heavy di-quark
by a linear scalar potential. Absorption of virtual photons promotes the quark
to bound states. The analog of the parton model for this case is for a virtual
photon to eject the bound, ground-state quark directly into free continuum
states. We compare the scaling limits of the response functions for these two
transitions
Gauging the three-nucleon spectator equation
We derive relativistic three-dimensional integral equations describing the
interaction of the three-nucleon system with an external electromagnetic field.
Our equations are unitary, gauge invariant, and they conserve charge. This has
been achieved by applying the recently introduced gauging of equations method
to the three-nucleon spectator equations where spectator nucleons are always on
mass shell. As a result, the external photon is attached to all possible places
in the strong interaction model, so that current and charge conservation are
implemented in the theoretically correct fashion. Explicit expressions are
given for the three-nucleon bound state electromagnetic current, as well as the
transition currents for the scattering processes
\gamma He3 -> NNN, Nd -> \gamma Nd, and \gamma He3 -> Nd. As a result, a
unified covariant three-dimensional description of the NNN-\gamma NNN system is
achieved.Comment: 23 pages, REVTeX, epsf, 4 Postscript figure
Herding model and 1/f noise
We provide evidence that for some values of the parameters a simple agent
based model, describing herding behavior, yields signals with 1/f power
spectral density. We derive a non-linear stochastic differential equation for
the ratio of number of agents and show, that it has the form proposed earlier
for modeling of 1/f^beta noise with different exponents beta. The non-linear
terms in the transition probabilities, quantifying the herding behavior, are
crucial to the appearance of 1/f noise. Thus, the herding dynamics can be seen
as a microscopic explanation of the proposed non-linear stochastic differential
equations generating signals with 1/f^beta spectrum. We also consider the
possible feedback of macroscopic state on microscopic transition probabilities
strengthening the non-linearity of equations and providing more opportunities
in the modeling of processes exhibiting power-law statistics
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