460 research outputs found
Perspectives of Tribal Communities on NTFP Resource Use in a Global Hotspot: Implications for Adaptive Management
Tribal communities depend on a large variety of Non-timber forest products (NTFPs) for their diverse needs, which has attracted high interest in recent years in view of increasing rural incomes and stimulating the forest management. This study investigates forest dependent (NTFPs based) livelihood in an ethnically diverse area in Northeast India, a global hotspot. We addressed two research questions: (1) what is the diversity of NTFPs resources that communities extract from the forest reserves to supplement their home needs? and (2) what are the perceptions of communities about sustainable development of NTFPs resources? We recorded 343 plant species that were used to fulfill varied needs of five tribal communities. Of them, 32% species harvested for their leaves and 27% for fruits. Dependence on NTFPs was more at high mountains. The seasonal use of NTFPs revealed that 79% species collected during lean period. Community perception on use of NTFPs revealed that 11% species consumed most frequently and 53% commonly. It was interesting to note that community residents sell as many as 76 species in the local markets to earn cash. All households collect NTFPs for sustenance while 31-41% households involved in commercial collection of species, viz. Taxus wallichiana, Aconitum fletcherianum, Ophiocordyceps sinensis, Swertia chirayita, Illicium griffithii, and Thalictrum foliolosum. There was a gradual decrease in use of NTFPs with young age because of high labour and availability of other options. The communities perceived that unscientific and excessive harvesting may threatened these species in near future. For adaptive management of NTFPs, communities suggested that capacity building on maximum allowable harvests and yield regulation measures, tenure improvement, domestication and plantations of selected species along with access to markets for NTFPs products will create better economic gains for communities at the same time it will lead to sustainable management of NTFPs. Keywords: Northeast India; global hotspot; NTFPs; sustainable use; consumption pattern; enterprises; livelihoods; adaptive managemen
Perspectives of Tribal Communities on NTFP Resource Use in a Global Hotspot: Implications for Adaptive Management
Tribal communities depend on a large variety of Non-timber forest products (NTFPs) for their diverse needs, which has attracted high interest in recent years in view of increasing rural incomes and stimulating the forest management. This study investigates forest dependent (NTFPs based) livelihood in an ethnically diverse area in Northeast India, a global hotspot. We addressed two research questions: (1) what is the diversity of NTFPs resources that communities extract from the forest reserves to supplement their home needs? and (2) what are the perceptions of communities about sustainable development of NTFPs resources? We recorded 343 plant species that were used to fulfill varied needs of five tribal communities. Of them, 32% species harvested for their leaves and 27% for fruits. Dependence on NTFPs was more at high mountains. The seasonal use of NTFPs revealed that 79% species collected during lean period. Community perception on use of NTFPs revealed that 11% species consumed most frequently and 53% commonly. It was interesting to note that community residents sell as many as 76 species in the local markets to earn cash. All households collect NTFPs for sustenance while 31-41% households involved in commercial collection of species, viz. Taxus wallichiana, Aconitum fletcherianum, Ophiocordyceps sinensis, Swertia chirayita, Illicium griffithii, and Thalictrum foliolosum. There was a gradual decrease in use of NTFPs with young age because of high labour and availability of other options. The communities perceived that unscientific and excessive harvesting may threatened these species in near future. For adaptive management of NTFPs, communities suggested that capacity building on maximum allowable harvests and yield regulation measures, tenure improvement, domestication and plantations of selected species along with access to markets for NTFPs products will create better economic gains for communities at the same time it will lead to sustainable management of NTFPs. Keywords: Northeast India; global hotspot; NTFPs; sustainable use; consumption pattern; enterprises; livelihoods; adaptive managemen
Nonlinear Spinor Fields and its role in Cosmology
Different characteristic of matter influencing the evolution of the Universe
has been simulated by means of a nonlinear spinor field. Exploiting the spinor
description of perfect fluid and dark energy evolution of the Universe given by
an anisotropic Bianchi type-VI, VI, V, III, I or isotropic
Friedmann-Robertson-Walker (FRW) one has been studied. It is shown that due to
some restrictions on metric functions, initial anisotropy in the models Bianchi
type-VI, VI, V and III does not die away, while the anisotropic Bianchi
type-I models evolves into the isotropic one.Comment: 22 pages, 12 Figure
Scalar field in cosmology: Potential for isotropization and inflation
The important role of scalar field in cosmology was noticed by a number of
authors. Due to the fact that the scalar field possesses zero spin, it was
basically considered in isotropic cosmological models. If considered in an
anisotropic model, the linear scalar field does not lead to isotropization of
expansion process. One needs to introduce scalar field with nonlinear potential
for the isotropization process to take place. In this paper the general form of
scalar field potentials leading to the asymptotic isotropization in case of
Bianchi type-I cosmological model, and inflationary regime in case of isotropic
space-time is obtained. In doing so we solved both direct and inverse problem,
where by direct problem we mean to find metric functions and scalar field for
the given potential, whereas, the inverse problem means to find the potential
and scalar field for the given metric function. The scalar field potentials
leading to the inflation and isotropization were found both for harmonic and
proper synchronic time.Comment: 10 page
Spinor model of a perfect fluid and their applications in Bianchi type-I and FRW models
Different characteristic of matter influencing the evolution of the Universe
has been simulated by means of a nonlinear spinor field. Exploiting the spinor
description of perfect fluid and dark energy evolution of the Universe given by
an anisotropic Bianchi type-I (BI) or isotropic Friedmann-Robertson-Walker
(FRW) one has been studied.Comment: 10 pages, 8 Figure
Ultra Long Period Cepheids: a primary standard candle out to the Hubble flow
The cosmological distance ladder crucially depends on classical Cepheids
(with P=3-80 days), which are primary distance indicators up to 33 Mpc. Within
this volume, very few SNe Ia have been calibrated through classical Cepheids,
with uncertainty related to the non-linearity and the metallicity dependence of
their period-luminosity (PL) relation. Although a general consensus on these
effects is still not achieved, classical Cepheids remain the most used primary
distance indicators. A possible extension of these standard candles to further
distances would be important. In this context, a very promising new tool is
represented by the ultra-long period (ULP) Cepheids (P \geq 80 days), recently
identified in star-forming galaxies. Only a small number of ULP Cepheids have
been discovered so far. Here we present and analyse the properties of an
updated sample of 37 ULP Cepheids observed in galaxies within a very large
metallicity range of 12+log(O/H) from ~7.2 to 9.2 dex. We find that their
location in the colour(V-I)-magnitude diagram as well as their Wesenheit (V-I)
index-period (WP) relation suggests that they are the counterparts at high
luminosity of the shorter-period (P \leq 80 days) classical Cepheids. However,
a complete pulsation and evolutionary theoretical scenario is needed to
properly interpret the true nature of these objects. We do not confirm the
flattening in the studied WP relation suggested by Bird et al. (2009). Using
the whole sample, we find that ULP Cepheids lie around a relation similar to
that of the LMC, although with a large spread (~0.4 mag).Comment: 8 pages, 4 figures, accepted for publication in Astrophysics & Space
Scienc
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
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