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1.
Social Capital,Collective Action and Group Formation: Developmental Trajectories in Post-socialist Mongolia 总被引:2,自引:1,他引:1
Caroline Upton 《Human ecology: an interdisciplinary journal》2008,36(2):175-188
Group formation, social capital and collective action have been the focus of much recent attention amongst donors and policy
makers. Optimistic scenarios highlight their contributions to poverty reduction and effective natural resource management.
However, recent critiques have focused on the exclusionary potential or ‘dark side’ of groups and social capital. Not only
are their longer term livelihood impacts unclear, but lacunae persist in our understanding of how social capital, especially
trust, is built. This paper presents a longitudinal evaluation of trust, collective action and cooperation among herders in
post-Soviet Mongolia in the context of recent donor projects. Results highlight the important catalytic effect of external
interventions in overcoming a lack of trust and promoting formalised collective action, but only in the context of a particular
conjunction of circumstances. Indications for livelihood outcomes confirm the differentiated benefits, exclusionary potential
and fragility of social capital and new institutional forms.
相似文献
Caroline UptonEmail: |
2.
The recent contribution by Jarmila Kukalová-Peck on Hennigian phylogenetics and hexapod limb evolution is critically evaluated.
相似文献
Michael S. Engel (Corresponding author)Email: |
3.
The Freshwater Animal Diversity Assessment (FADA) project aims at compiling an overview of genus- and species-level diversity
of animals in the continental, aquatic ecosystems of the world. It is a collective effort of 163 experts, and presents 59
articles treating the diversity and endemism of different animal taxa, ranging from microscopic worms to mammals, at global
and regional scales. Given their structural importance, an article on macrophytes is also added. Here, we give an overview
of the project’s history, and outline the common framework of the various articles, as well as the conventions the experts
agreed to adhere to in their treatises. Furthermore, we briefly introduce future prospects.
相似文献
E. V. BalianEmail: |
4.
5.
Information,complexity and generative replication 总被引:3,自引:0,他引:3
The established definition of replication in terms of the conditions of causality, similarity and information transfer is
very broad. We draw inspiration from the literature on self-reproducing automata to strengthen the notion of information transfer
in replication processes. To the triple conditions of causality, similarity and information transfer, we add a fourth condition
that defines a “generative replicator” as a conditional generative mechanism, which can turn input signals from an environment into developmental instructions. Generative replication must have the potential to enhance complexity, which in turn requires that developmental instructions are part
of the information that is transmitted in replication. Demonstrating the usefulness of the generative replicator concept in
the social domain, we identify social generative replicators that satisfy all of the four proposed conditions.
相似文献
Geoffrey M. HodgsonEmail: |
6.
Sub-Antarctic Marion Island has had a permanent research station for 50 years and the islands Wandering Albatrosses have been intensively studied for 20 years. The reactions of breeding birds to approaches by a human on foot were recorded. Three response variables were calculated: intensity of vocal reaction (IVR), intensity of non-vocal reaction (INR) and overall response index (ORI). At 5 m from the nest, twice as many birds stood and/or vocalised as at 15 m. Nearest neighbour distance, age and gender did not explain individual variability of responses. Study colony birds had higher IVR scores than non-study colony birds; birds at colonies closest to the station had the highest ORI scores. A better breeding record was associated with lower IVR and ORI scores, but a causative relationship remains to be demonstrated. A minimum viewing distance of 25 m is recommended for breeding Wandering Albatrosses.
相似文献
Marienne S. de VilliersEmail: Fax: +27-21-6503434 |
John CooperEmail: |
Peter G. RyanEmail: |
7.
8.
Smallholders and the ‘Household Responsibility System’: Adapting to Institutional Change in Chinese Agriculture 总被引:1,自引:0,他引:1
During the last quarter century, China’s agricultural sector has undergone a dramatic transformation from collective to private
production under the so-called “Household Responsibility System.” This incentive system, designed to increase yields, reallocated
communal land to peasant households, creating hundreds of millions of smallholders with relative autonomy over land use decisions
and crop selection. Based on recent ethnographic research, this paper discusses the smallholder farming system of a mixed-ethnic
community that intensively cultivates small land plots for subsistence and market exchange in China’s populous southwestern
province of Sichuan. The paper characterizes the smallholder system in terms of biodiversity of plant and animal species,
market distribution of crops, multiple cropping systems, and labor and technology inputs. The paper also describes how smallholders
adapt their agricultural practices and decisions to changing market conditions and agricultural policies. Significantly, these
adaptive strategies focus on shifting to the production of various cash crops, including melons and mangoes. Implications
for the long-term viability of China’s smallholders, particularly in ecologically and economically marginal areas, are also
discussed.
相似文献
Bryan TiltEmail: |
9.
10.
Pete Beckman Kamil Iskra Kazutomo Yoshii Susan Coghlan Aroon Nataraj 《Cluster computing》2008,11(1):3-16
We investigate operating system noise, which we identify as one of the main reasons for a lack of synchronicity in parallel
applications. Using a microbenchmark, we measure the noise on several contemporary platforms and find that, even with a general-purpose
operating system, noise can be limited if certain precautions are taken. We then inject artificially generated noise into
a massively parallel system and measure its influence on the performance of collective operations. Our experiments indicate
that on extreme-scale platforms, the performance is correlated with the largest interruption to the application, even if the
probability of such an interruption on a single process is extremely small. We demonstrate that synchronizing the noise can
significantly reduce its negative influence.
相似文献
Aroon NatarajEmail: |
11.
Peter Godfrey-Smith 《Biology & philosophy》2007,22(3):429-437
Jablonka and Lamb's claim that evolutionary biology is undergoing a ‘revolution’ is queried. But the very concept of revolutionary
change has uncertain application to a field organized in the manner of contemporary biology. The explanatory primacy of sequence
properties is also discussed.
相似文献
Peter Godfrey-SmithEmail: |
12.
Natalia V. Ivanova Aron J. Fazekas Paul D. N. Hebert 《Plant Molecular Biology Reporter》2008,26(3):186-198
Many plant species are considered difficult for DNA isolation due to their high concentrations of secondary metabolites such
as polysaccharides and polyphenols. Several protocols have been developed to overcome this problem, but they are typically
time-consuming, not scalable for high throughput and not compatible with automation. Although a variety of commercial kits
are available for plant DNA isolation, their cost is high and these kits usually have limited taxonomic applicability. In
a previous study we developed an inexpensive automation-friendly protocol for DNA extraction from animal tissues. Here we
demonstrate that a similar protocol allows DNA isolation from plants.
相似文献
Natalia V. IvanovaEmail: |
13.
Terry Harmer 《Cluster computing》2007,10(3):277-285
Gridcast is an R&D project investigating grid ideas and technologies in the broadcasting technical infrastructure. In this
paper I discuss the business and technical issues in building infrastructures to support broadcasters and outline the structure
of the Gridcast grid-based service oriented architecture for broadcasting playout support.
相似文献
Terry HarmerEmail: |
14.
Gérard Battail 《Biosemiotics》2008,1(2):221-238
This paper is intended to complement our previous works on the necessary existence of error-correcting codes endowing genomes
with the ability of being regenerated, not merely copied. It sketchily recalls some fundamental definitions and results of
information theory and error-correcting codes; provides an overview of our research; shows that the disjunction of replication
and regeneration enlightens the divide between germinal and somatic cells; suggests that some phenomena referred to as epigenetic
may possibly find an explanation within the framework of error-correcting codes; points out some difficulties, especially
those related to sexual reproduction; criticizes the template-replication paradigm, and prompts geneticists to become familiar
with information theory.
相似文献
Gérard BattailEmail: |
15.
James Carney 《Biosemiotics》2008,1(3):313-327
The basic premise of biosemiotics as a discipline is that there are elementary processes linking signifying strategies in
all forms of animate life. Correspondingly, the discoveries of biosemiotics should, in principle, be capable of revealing
new insights about human signification. In the present article, I show that this is in fact the case by constructing a biosemiotic
model that links advertising strategies with corresponding structures in animal predation. The methodological framework for
this model is the catastrophe theory of René Thom. The end result is a revised understanding of an ostensibly cultural phenomenon
that demonstrates its continuity with signalling processes conventionally associated with the natural world.
相似文献
James CarneyEmail: |
16.
Roswitha Wiltschko Ursula Munro Hugh Ford Wolfgang Wiltschko 《Journal of Ornithology》2008,149(4):607-614
Experiments with migrating birds on the interaction between magnetic and celestial cues have produced heterogeneous results.
A recent study claimed that the magnetic compass in passerine migrants is calibrated by the pattern of polarized light at
sunset and sunrise and that the area just above the horizon is crucial for this calibration. To test the latter hypothesis,
we performed a similar experiment with Australian Silvereyes. It produced contrary results, however, the birds, in spite of
observing the natural polarization pattern at sunrise and sunset down to the horizon in an altered magnetic field, continued
in their normal southerly magnetic direction when subsequently tested in the local geomagnetic field—the conflict between
magnetic and polarized light cues had not caused them to recalibrate their magnetic compass. This contradicts the assumption
that skylight polarization patterns generally serve as a primary calibration reference for migratory songbirds.
相似文献
Roswitha WiltschkoEmail: |
17.
Roger Sansom 《Biology & philosophy》2008,23(4):475-491
I show that gene regulation networks are qualitatively consistent and therefore sufficiently similar to linearly seperable
connectionist networks to warrant that the connectionist framework be applied to gene regulation. On this view, natural selection
designs gene regulation networks to overcome the difficulty of development. I offer some general lessons about their evolvability
that can be learned by examining the generic features of connectionist networks.
相似文献
Roger SansomEmail: |
18.
It is known that the relationship between humans and their animals is important for understanding many aspects of nomadic
pastoralist systems, including nomadic movement. However, to date, these complex human–animal relations have not been analyzed
in a way that has led to an explanatory model of nomadic movement capable of producing testable hypotheses. Based on ethnographic
material collected amongst Komi and Nenets nomadic reindeer herders of the Russian Arctic, we argue that nomadic movements
can be best understood as a product of the interplay that exists between animal behaviour and the herders’ skilful actions
to (a) maintain herd cohesion and (b) avoid hazards, whilst deploying the minimum amount of resources (i.e., human/animal
effort and use of equipment) on rounding up the herd, stopping and turning it. Ecological factors affect movement through
their influence on animal behaviour, whereas non-ecological factors do so by influencing the herders’ skilful actions. We
demonstrate that, based on these assumptions, it is possible to build a testable model explaining the movement of some nomadic
groups.
相似文献
K. V. IstominEmail: |
19.
A key point in the analysis of dynamical models of biological systems is to handle systems of relatively high dimensions.
In the present paper we propose a method to hierarchically organize a certain type of piecewise affine (PWA) differential
systems. This specific class of systems has been extensively studied for the past few years, as it provides a good framework
to model gene regulatory networks. The method, shown on several examples, allows a qualitative analysis of the asymptotic
behavior of a PWA system, decomposing it into several smaller subsystems. This technique, based on the well-known strongly
connected components decomposition, is not new. However, its adaptation to the non-smooth PWA differential equations turns
out to be quite relevant because of the strong discrete structure underlying these equations. Its biological relevance is
shown on a 7-dimensional PWA system modeling the gene network responsible for the carbon starvation response in Escherichia coli.
相似文献
Laurent Tournier (Corresponding author)Email: |
Jean-Luc GouzéEmail: |
20.
Philip Richard Sullivan 《Biology & philosophy》2009,24(1):65-79
This paper demonstrates that the human visual system, the primary sensory conduit for primates, processes ambient energy in
a way that obligatorily constructs the objects that we ineluctably perceive. And since our perceptual apparatus processes
information only in terms of objects (along with the properties and movements of objects), we are limited in our ability to comprehend ‘what
is’ when we move beyond our ordinary world of midsize objects—as, for example, when we address the micro microworld of quantum
physics.
相似文献
Philip Richard SullivanEmail: |