231 research outputs found
The effect of the diffusion of new agricultural and related technologies on income distribution among rural people in Kenya
Equitable development is one of Kenya's current objectives, and will increasingly be emphasized in the next plan period. Yet, there is considerable evidence to suggest that development is far equitable at present, partly for political reasons, and partly because of autonomous development processes tend to foster inequity.
This paper concentrates on such autonomous processes in rural development and proposes research to uncover present trends in equity differentials in rural areas -which result from the diffusion of new income generating technologies in agriculture. The proposed research also hopes to identify likely forces which accelerate inequitable development and which can be manipulated to produce greater equity.
The proposed research will be a panel study. That is, a sample of Tetu farmers who were interviewed in 1970 on adoption behaviors, will be interviewed again on similar variables to produce insights in trends and processes. In addition, more detailed information will be gathered on variables describing levels of living, consolidation of economic as well as political power, etc.
The study forms part of the Tetu Special Rural Development Programme's (S.R.D.P) extension pilot project which aims at developing replicable methods for equitable rural development through the dissemination of new technology to farmers who have remained or lagged behind in the scramble "to make it"
Nonlinear Ionic Conductivity of Thin Solid Electrolyte Samples: Comparison between Theory and Experiment
Nonlinear conductivity effects are studied experimentally and theoretically
for thin samples of disordered ionic conductors. Following previous work in
this field the {\it experimental nonlinear conductivity} of sodium ion
conducting glasses is analyzed in terms of apparent hopping distances. Values
up to 43 \AA are obtained. Due to higher-order harmonic current density
detection, any undesired effects arising from Joule heating can be excluded.
Additionally, the influence of temperature and sample thickness on the
nonlinearity is explored. From the {\it theoretical side} the nonlinear
conductivity in a disordered hopping model is analyzed numerically. For the 1D
case the nonlinearity can be even handled analytically. Surprisingly, for this
model the apparent hopping distance scales with the system size. This result
shows that in general the nonlinear conductivity cannot be interpreted in terms
of apparent hopping distances. Possible extensions of the model are discussed.Comment: 7 pages, 6 figure
Matrix controlled channel diffusion of sodium in amorphous silica
To find the origin of the diffusion channels observed in sodium-silicate
glasses, we have performed classical molecular dynamics simulations of
NaO--4SiO during which the mass of the Si and O atoms has been
multiplied by a tuning coefficient. We observe that the channels disappear and
that the diffusive motion of the sodium atoms vanishes if this coefficient is
larger than a threshold value. Above this threshold the vibrational states of
the matrix are not compatible with those of the sodium ions. We interpret hence
the decrease of the diffusion by the absence of resonance conditions.Comment: 5 pages, 4 figure
Factors Affecting European FarmersâParticipation in Biodiversity Policies
This article reports the major findings from an interdisciplinary research project that synthesises key insights into farmersâ willingness and ability to co-operate with biodiversity policies. The results of the study are based on an assessment of about 160
publications and research reports from six EU member states and from international comparative research.We developed a conceptual framework to systematically review the
existent literature relevant for our purposes. This framework provides a common structure for analysing farmersâ perspectives regarding the introduction into farming practices of measures relevant to biodiversity. The analysis is coupled and contrasted with a survey of experts. The results presented above suggest that it is important to view support for practices oriented towards biodiversity protection not in a static sense â as a situation determined by one or several influencing factors â but rather as a process marked by interaction. Financial compensation and incentives function as a necessary, though
clearly not sufficient condition in this process
Channel diffusion of sodium in a silicate glass
We use classical molecular dynamics simulations to study the dynamics of
sodium atoms in amorphous NaO-4SiO. We find that the sodium
trajectories form a well connected network of pockets and channels. Inside
these channels the motion of the atoms is not cooperative but rather given by
independent thermally activated hops of individual atoms between the pockets.
By determining the probability that an atom returns to a given starting site,
we show that such events are not important for the dynamics of this system.Comment: 10 pages of Latex, 5 figures, one figure added, text expande
The uptake of different tillage practices in England
Reduced tillage systems have been argued to provide several potential benefits to soil, environment and to farm incomes. In England, while many farms have partially adopted such practices, a large proportion of arable farmers do not undertake reduced tillage in any form. This paper analyses the rationale for and uptake of different cultivation techniques, including analysis of the barriers to adoption of reduced tillage, aiming to benefit policy makers and researchers and increase the spread of smart agricultural practices. Based on a postal questionnaire, we estimated that 47.6% of English arable land is cultivated using minimumâtillage and 7% under noâtillage. As farm size increased, so did the probability of reduced tillage uptake. Furthermore, farms growing combinable crops were more likely to utilise reduced tillage approaches than other farm types. Soil type, weed control and weather conditions were noted as the main drivers for âstrategic' and ârotational' ploughing, constraining continuous reduced tillage use. To effect greater reduced tillage uptake, greater communication between researchers and farmers is needed to facilitate the implementation of sustainable soil management solutions, supported by current legislation permitting responsible herbicide use in arable production. Financial support to access reduced tillage machinery may also be required for farmers operating smaller holdings. Adopting reduced tillage is a continuous learning process requiring ongoing training and informationâgathering; supporting a network of reduced tillage âfarmer champions' would facilitate practical knowledge exchange, allow farmers to observe soil improvements, understand transition phase barriers, and ultimately encourage increased reduced tillage uptake
The electric double layer has a life of its own
Using molecular dynamics simulations with recently developed importance
sampling methods, we show that the differential capacitance of a model ionic
liquid based double-layer capacitor exhibits an anomalous dependence on the
applied electrical potential. Such behavior is qualitatively incompatible with
standard mean-field theories of the electrical double layer, but is consistent
with observations made in experiment. The anomalous response results from
structural changes induced in the interfacial region of the ionic liquid as it
develops a charge density to screen the charge induced on the electrode
surface. These structural changes are strongly influenced by the out-of-plane
layering of the electrolyte and are multifaceted, including an abrupt local
ordering of the ions adsorbed in the plane of the electrode surface,
reorientation of molecular ions, and the spontaneous exchange of ions between
different layers of the electrolyte close to the electrode surface. The local
ordering exhibits signatures of a first-order phase transition, which would
indicate a singular charge-density transition in a macroscopic limit
Farmer-Scientist Knowledge Exchange
The last 25 years has seen a paradigm shift in the understanding of the nature of knowledge and how it is
exchanged in the agricultural context. A changing backdrop, with the move towards multi-functional land
management, persistent environmental problems and the search for sustainable agricultural approaches, has
brought new challenges. At the same time the research agenda on knowledge has changed as an era of
positivism, during which science and scientific experts were given unrivalled authority, was challenged by
social studies of science that began to question the superiority of scientific knowledge, and value alternative
forms of knowledge such as those held by farmers. Theory and practice of knowledge exchange in agriculture
has evolved in line with this, shifting from a linear model of knowledge transfer to a perspective that
integrates knowledge from multiple actors through facilitation and participation and emphasises learning in a
social context
Training Programmes Can Change Behaviour and Encourage the Cultivation of Over-Harvested Plant Species
Cultivation of wild-harvested plant species has been proposed as a way of reducing over-exploitation of wild populations but lack of technical knowledge is thought to be a barrier preventing people from cultivating a new species. Training programmes are therefore used to increase technical knowledge to encourage people to adopt cultivation. We assessed the impact of a training programme aiming to encourage cultivation of xaté (Chamaedorea ernesti-augusti), an over-harvested palm from Central America. Five years after the training programme ended, we surveyed untrained and trained individuals focusing on four potential predictors of behaviour: technical knowledge, attitudes (what individuals think about a behaviour), subjective norms (what individuals perceive others to think of a behaviour) and perceived behavioural control (self assessment of whether individuals can enact the behaviour successfully). Whilst accounting for socioeconomic variables, we investigate the influence of training upon these behavioural predictors and examine the factors that determine whether people adopt cultivation of a novel species. Those who had been trained had higher levels of technical knowledge about xaté cultivation and higher belief in their ability to cultivate it while training was not associated with differences in attitudes or subjective norms. Technical knowledge and perceived behavioural control (along with socio-economic variables such as forest ownership and age) were predictors of whether individuals cultivate xaté. We suggest that training programmes can have a long lasting effect on individuals and can change behaviour. However, in many situations other barriers to cultivation, such as access to seeds or appropriate markets, will need to be addressed
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