89 research outputs found
The data not collected on community forestry
Conservation and development practitioners increasingly promote community forestry as a way to conserve ecosystem services, consolidate resource rights, and reduce poverty. However, outcomes of community forestry have been mixed; many initiatives failed to achieve intended objectives. There is a rich literature on institutional arrangements of community forestry, but there has been little effort to examine the role of socioeconomic, market, and biophysical factors in shaping both land-cover change dynamics and individual and collective livelihood outcomes. We systematically reviewed the peer-reviewed literature on community forestry to examine and quantify existing knowledge gaps in the community-forestry literature relative to these factors. In examining 697 cases of community forest management (CFM), extracted from 267 peer-reviewed publications, we found 3 key trends that limit understanding of community forestry. First, we found substantial data gaps linking population dynamics, market forces, and biophysical characteristics to both environmental and livelihood outcomes. Second, most studies focused on environmental outcomes, and the majority of studies that assessed socioeconomic outcomes relied on qualitative data, making comparisons across cases difficult. Finally, there was a heavy bias toward studies on South Asian forests, indicating that the literature on community forestry may not be representative of decentralization policies and CFM globally
Metallo-dielectric diamond and zinc-blende photonic crystals
It is shown that small inclusions of a low absorbing metal can have a
dramatic effect on the photonic band structure. In the case of diamond and
zinc-blende photonic crystals, several complete photonic band gaps (CPBG's) can
open in the spectrum, between the 2nd-3rd, 5th-6th, and 8th-9th bands. Unlike
in the purely dielectric case, in the presence of small inclusions of a low
absorbing metal the largest CPBG for a moderate dielectric constant
(epsilon<=10) turns out to be the 2nd-3rd CPBG. The 2nd-3rd CPBG is the most
important CPBG, because it is the most stable against disorder. For a diamond
and zinc-blende structure of nonoverlapping dielectric and metallo-dielectric
spheres, a CPBG begins to decrease with an increasing dielectric contrast
roughly at the point where another CPBG starts to open--a kind of gap
competition. A CPBG can even shrink to zero when the dielectric contrast
increases further. Metal inclusions have the biggest effect for the dielectric
constant 2<=epsilon<=12, which is a typical dielectric constant at near
infrared and in the visible for many materials, including semiconductors and
polymers. It is shown that one can create a sizeable and robust 2nd-3rd CPBG at
near infrared and visible wavelengths even for a photonic crystal which is
composed of more than 97% low refractive index materials (n<=1.45, i.e., that
of silica glass or a polymer). These findings open the door for any
semiconductor and polymer material to be used as genuine building blocks for
the creation of photonic crystals with a CPBG and significantly increase the
possibilities for experimentalists to realize a sizeable and robust CPBG in the
near infrared and in the visible. One possibility is a construction method
using optical tweezers, which is analyzed here.Comment: 25 pp, 23 figs, RevTex, to appear in Phys Rev B. For more information
look at
http://www.amolf.nl/research/photonic_materials_theory/moroz/moroz.htm
Cosmology, Particle Physics and Superfluid 3He
Many direct parallels connect superfluid 3He with the field theories
describing the physical vacuum, gauge fields and elementary fermions.
Superfluid He exhibits a variety of topological defects which can be
detected with single-defect sensitivity. Modern scenarios of defect-mediated
baryogenesis can be simulated by the interaction of the 3He vortices and domain
walls with fermionic quasiparticles. Formation of defects in a
symmetry-breaking phase transition in the early Universe, which could be
responsible for large-scale structure formation and for microwave-background
anisotropy, also may be modelled in the laboratory. This is supported by the
recent observation of vortex formation in neutron-irradiated 3He-B where the
"primordial fireball" is formed in an exothermic nuclear reaction.Comment: Invited talk at LT-21 Conference, 20 pages, 3 figures available at
request, compressed ps file of the camera-ready format with 3 figures is at
ftp://boojum.hut.fi/pub/publications/lowtemp/LTL-96006.ps.g
Between Governance-Driven Democratisation and Democracy-Driven Governance: explaining changes in Participatory Governance in the Case of Barcelona
Scholars of participatory democracy have long noted dynamic interactions and transformations within and between political spaces that can foster (de)democratisation. At the heart of this dynamism lie (a) the processes through which topâdown âclosedâ spaces can create opportunities for rupture and democratic challenges and (b) viceâversa, the mechanisms through which bottomâup, open spaces can be coâopted through institutionalisation. This paper seeks to unpick dynamic interactions between different spaces of participation by looking specifically at two forms of participatory governance, or participatory forms of political decision making used to improve the quality of democracy. First, Mark Warren's concept of âgovernanceâdriven democratizationâ describes topâdown and technocratic participatory governance aiming to produce better policies in response to bureaucratic rationales. Second, we introduce a new concept, democracyâdriven governance, to refer to efforts by social movements to invent new, and reclaim and transform existing, spaces of participatory governance and shape them to respond to citizensâ demands. The paper defines these concepts and argues that they coâexist and interact in dynamic fashion; it draws on an analysis of case study literature on participatory governance in Barcelona to illuminate this relationship. Finally, the paper relates the theoretical framework to the case study by making propositions as to the structural and agential drivers of shifts in participatory governance
Soybean meal or cotton by-products associated with urea as source of nitrogen in the diet of lactating goats
Ganho compensatório em cordeiras na fase de recria: desempenho e medidas biométricas
Three three-letter words in three recent novels in three different languages: God, sex and joy
Perfil energĂ©tico e hormonal de ovelhas Santa InĂȘs do terço mĂ©dio da gestação ao pĂłs-parto
Produção de proteĂna microbiana e estimativas das excreçÔes de derivados de purinas e de urĂ©ia em vacas lactantes alimentadas com raçÔes isoprotĂ©icas contendo diferentes nĂveis de compostos nitrogenados nĂŁo-protĂ©icos
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