6,122 research outputs found
The role of traditional land use systems in the well-being of rural Timor-Leste
Natural ecosystems and traditional land use systems have an important role in the life and well being of the rural population of Timor-Leste. The land itself is the support of natural ecosystems and subsistence agriculture of rural populations of East Timor and is the main focus of this research. This paper is part of work in progress. Our research, located in rural Timor-Leste focuses on land tenure, rural family income and the mechanisms that will induce changes in the rules of traditional society organisation. The main objectives of this paper are: 1) to identify the different land use patterns of Timor-Leste; 2) to identify the goods and services produced by them and 3) to relate the services produced by land use patterns with the well-being of Timor-Leste rural population. This paper is based on a multidisciplinary approach incorporating contributions from several fields of knowledge, and uses documentary sources, direct observations made in various periods in the field and interviews conducted in 2003, 2009 and 2010. We identify as the main land use patterns in Timor-Leste the following ones: natural and semi-natural ecosystems, subsistence agriculture, sacred, housing and basic infrastructures and Industries and services. For Timor-Leste rural communities the above land use patterns produce a set of goods and services, which can be classified as supporting, provisioning, regulating and cultural goods and services, and those are essential for their survival and well-being. The conceptual framework used to examine the above mentioned issues is the human rights approach to development within which human rights are considered as means and objectives of development as much as economic purposes.Timor-Leste, land use patterns, ecosystems goods and services, well-being.
Fractional regression models for second stage DEA efficiency analyses
Data envelopment analysis (DEA) is commonly used to measure the relative efficiency of decision-making units. Often, in a second stage, a regression model is estimated to relate DEA efficiency scores to exogenous factors. In this paper, we argue that the traditional linear or tobit approaches to second-stage DEA analysis do not constitute a reasonable data-generating process for DEA scores. Under the assumption that DEA scores can be treated as descriptive measures of the relative performance of units in the sample, we show that using fractional regression models are the most natural way of modeling bounded, proportional response variables such as DEA scores. We also propose generalizations of these models and, given that DEA scores take frequently the value of unity, examine the use of two-part models in this framework. Several tests suitable for assessing the specification of each alternative model are also discussed.Second-stage DEA; Fractional data; Specification tests; One outcomes; Two-part models.
Primary interoceptive cortex activity during simulated experiences of the body
Studies of the classic exteroceptive sensory systems (e.g., vision, touch) consistently demonstrate that
vividly imagining a sensory experience of the world â simulating it â is associated with increased
activity in the corresponding primary sensory cortex. We hypothesized, analogously, that simulating
internal bodily sensations would be associated with increased neural activity in primary interoceptive
cortex. An immersive, language-based mental imagery paradigm was used to test this hypothesis (e.g.,
imagine your heart pounding during a roller coaster ride, your face drenched in sweat during a
workout). During two neuroimaging experiments, participants listened to vividly described situations
and imagined âbeing thereâ in each scenario. In Study 1, we observed significantly heightened activity
in primary interoceptive cortex (of dorsal posterior insula) during imagined experiences involving
vivid internal sensations. This effect was specific to interoceptive simulation: it was not observed
during a separate affect focus condition in Study 1, nor during an independent Study 2 that did not
involve detailed simulation of internal sensations (instead involving simulation of other sensory
experiences). These findings underscore the large-scale predictive architecture of the brain and reveal
that words can be powerful drivers of bodily experiences
Diluted Random Fields in Mixed Cyanide Crystals
A percolation argument and a dilute compressible random field Ising model are
used to present a simple model for mixed cyanide crystals. The model reproduces
quantitatively several features of the phase diagrams altough some crude
approximations are made. In particular critical thresholds x_c at which
ferroelastic first order transitions disappear, are calculated. Moreover,
transitions are found to remain first order down to x_c for all mixtures except
for bromine, for which the transition becomes continuous. All the results are
in full agreement with experimental data.Comment: 8 pages, late
Stable Umbral Chromospheric Structures
Aims. To understand the morphology of the chromosphere in sunspot umbra. We
investigate if the horizontal structures observed in the spectral core of the
Ca II H line are ephemeral visuals caused by the shock dynamics of more stable
structures, and examine their relationship with observables in the H-alpha
line. Methods. Filtergrams in the core of the Ca II H and H-alpha lines as
observed with the Swedish 1-m Solar Telescope are employed. We utilise a
technique that creates composite images and tracks the flash propagation
horizontally. Results. We find 0"15 wide horizontal structures, in all of the
three target sunspots, for every flash where the seeing was moderate to good.
Discrete dark structures are identified that are stable for at least two umbral
flashes, as well as systems of structures that live for up to 24 minutes. We
find cases of extremely extended structures with similar stability, with one
such structure showing an extent of 5". Some of these structures have a
correspondence in H-alpha but we were unable to find a one to one
correspondence for every occurrence. If the dark streaks are formed at the same
heights as umbral flashes then there are systems of structures with strong
departures from the vertical for all three analysed sunspots. Conclusions.
Long-lived Ca II H filamentary horizontal structures are a common and likely
ever-present feature in the umbra of sunspots. If the magnetic field in the
chromosphere of the umbra is indeed aligned with the structures, then the
present theoretical understanding of the typical umbra needs to be revisited.Comment: Accepted to Astronomy and Astrophysics. Online material (Fig3.mov and
Fig4.mov) will be available at A&
Optimal escape from circular orbits around black holes
Using the theory of optimal rocket trajectories in general relativity,
recently developed in arXiv:1105.5235, we show that the "obvious" manoeuvre of
using a tangential instantaneous acceleration to escape a stable circular orbit
in the Schwarzschild spacetime satisfies the optimality conditions if and only
if the magnitude of the acceleration is smaller than a certain bound.Comment: 7 page
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