900 resultados para Joint Ventures


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Forest managers in developing countries enforce extraction restrictions to limit forest degradation. In response, villagers may displace some of their extraction to other forests, which generates “leakage” of degradation. Managers also implement poverty alleviation projects to compensate for lost resource access or to induce conservation. We develop a model of spatial joint production of bees and fuelwood that is based on forest-compatible projects such as beekeeping in Thailand, Tanzania, and Mexico. We demonstrate that managers can better determine the amount and pattern of degradation by choosing the location of both enforcement and the forest-based activity.

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Hydrogen sulfide (H(2)S) has recently been proposed as an endogenous mediator of inflammation and is present in human synovial fluid. This study determined whether primary human articular chondrocytes (HACs) and mesenchymal progenitor cells (MPCs) could synthesize H(2)S in response to pro-inflammatory cytokines relevant to human arthropathies, and to determine the cellular responses to endogenous and pharmacological H(2)S. HACs and MPCs were exposed to IL-1β, IL-6, TNF-α and lipopolysaccharide (LPS). The expression and enzymatic activity of the H(2)S synthesizing enzymes cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE) were determined by Western blot and zinc-trap spectrophotometry, respectively. Cellular oxidative stress was induced by H(2)O(2), the peroxynitrite donor SIN-1 and 4-hydroxynonenal (4-HNE). Cell death was assessed by 3-(4,5-dimethyl-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. Mitochondrial membrane potential (DCm) was determined in situ by flow cytometry. Endogenous H(2) S synthesis was inhibited by siRNA-mediated knockdown of CSE and CBS and pharmacological inhibitors D,L-propargylglycine and aminoxyacetate, respectively. Exogenous H(2)S was generated using GYY4137. Under basal conditions HACs and MPCs expressed CBS and CSE and synthesized H(2)S in a CBS-dependent manner, whereas CSE expression and activity was induced by treatment of cells with IL-1β, TNF-α, IL-6 or LPS. Oxidative stress-induced cell death was significantly inhibited by GYY4137 treatment but increased by pharmacological inhibition of H(2)S synthesis or by CBS/CSE-siRNA treatment. These data suggest CSE is an inducible source of H(2)S in cultured HACs and MPCs. H(2)S may represent a novel endogenous mechanism of cytoprotection in the inflamed joint, suggesting a potential opportunity for therapeutic intervention.

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The doctrine of joint criminal enterprise is in disarray. Despite repeated judicial scrutiny at the highest level, the doctrine's scope, proper doctrinal basis and function in relation to other modes of complicity remain uncertain. This article examines the doctrine's elements and underlying principles. It argues that while joint criminal enterprise is largely used to make individuals liable for offences committed by their associates in excess of the common criminal purpose, its proper function is to police the limits of associate liability and thus to exculpate rather than inculpate. The doctrine governs not only instances of accessorial liability; it also applies where the parties involved are joint principal offenders. As this puts into question the prevalent view that joint criminal enterprise is a form of secondary participation that results in accessorial liability, the article concludes that it is best seen as a doctrine sui generis.

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In this paper we address three challenges. First, we discuss how international new ventures (INVs) are probably not explained by the Uppsala model as there is no time for learning about foreign markets in newly born and small firms. Only in the longer term can INVs develop experiential learning to overcome the liability of foreignness as they expand abroad. Second, we advance theoretically on previous research demonstrating that the multinationality−performance relationship of INVs follows a traditional S-shaped relationship, but they first experience a ‘born global illusion’ which leads to a non-traditional M curve. Third, using a panel data analysis for the period 1994–2008 we find empirically that Spanish INVs follow an inverted U curve in the very short term, where no learning takes place, but that experience gained over time yields an M-curve relationship once learning takes place.

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In this paper, we propose a compensation method for the joint effect of high-power amplifier (HPA) nonlinearity, in-phase/quadrature-phase (I/Q) imbalance and crosstalk in multiple-input multiple-output (MIMO) orthogonal space-time block coding (OSTBC) systems. The performance of the MIMO OSTBC equipped with the proposed compensation mechanism is evaluated in terms of average symbol error probability and system capacity, in Rayleigh fading channels. Numerical results are provided and show the effects on performance of several system parameters, namely, the HPA parameters, image-leakage ratio, crosstalk, numbers of antennas, and phase-shift keying modulation order.

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In this paper, we investigate the joint effects of high-power amplifier (HPA) nonlinearity, in-phase/quadrature-phase (I/Q) imbalance and crosstalk, on the performance of multiple-input multiple-output (MIMO) transmit beamforming (TB) systems, and propose a compensation method for the three impairments together. The performance of the MIMO TB system equipped with the proposed compensation scheme is evaluated in terms of average symbol error probability and capacity when transmissions are performed over uncorrelated Rayleigh fading channels. Numerical results are provided and show the effects on performance of several system parameters, namely, the HPA parameters, image-leakage ratio, crosstalk, numbers of antennas, length of pilot symbols and phase-shift keying modulation order.

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This manuscript describes the energy and water components of a new community land surface model called the Joint UK Land Environment Simulator (JULES). This is developed from the Met Office Surface Exchange Scheme (MOSES). It can be used as a stand alone land surface model driven by observed forcing data, or coupled to an atmospheric global circulation model. The JULES model has been coupled to the Met Office Unified Model (UM) and as such provides a unique opportunity for the research community to contribute their research to improve both world-leading operational weather forecasting and climate change prediction systems. In addition JULES, and its forerunner MOSES, have been the basis for a number of very high-profile papers concerning the land-surface and climate over the last decade. JULES has a modular structure aligned to physical processes, providing the basis for a flexible modelling platform.

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The authors provide an analytic framework for studying the joint influence of personal achievement goals and classroom goal structures on achievement-relevant outcomes. This framework encompasses 3 models (the direct effect model, indirect effect model, and interaction effect model), each of which addresses a different aspect of the joint influence of the 2 goal levels. These 3 models were examined together with a sample of 1,578 Japanese junior high and high school students from 47 classrooms. Results provided support for each of the 3 models: Classroom goal structures were not only direct, but also indirect predictors of intrinsic motivation and academic self-concept, and some cross-level interactions between personal achievement goals and classroom goal structures were observed (indicating both goal match and goal mismatch effects). A call is made for more research that takes into consideration achievement goals at both personal and structural levels of representation. (PsycINFO Database Record (c) 2012 APA, all rights reserved)(journal abstract)

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Objectives. The overarching aim of this paper is to consider the relationship between social entrepreneurship and rural development, and as a mechanism to address social exclusion in the Global South, with specific reference to Sub-Saharan Africa. Drawing upon a number of case examples of social purpose ventures in Kenya, Mozambique and Zambia the objectives of this paper are: - To provide a synthesis of existing literature on the interaction between social purpose ventures and rural BoP communities in the developing world; - To explore extant social exclusion literature including economic, political and international development dimensions; and - To analyse the case study examples to consider the channels through which social purpose ventures contribute to tackling social exclusion amongst the rural BoP. Prior Work. There is growing interest in the role that social enterprises and wider social purpose ventures can play in sustainable development in the Global South. In many developing countries the majority of the population still reside in rural areas with these areas often particularly marginalised and underdeveloped. Previous studies have provided anecdotal examples where social purpose ventures have the potential to provide innovative solutions to the development challenges faced by rural households and communities. Yet research in this area remains relatively nascent and fragmented. In depth empirical studies examining social purpose ventures and rural development in the Global South are furthermore limited. Approach. Data was collected during in-depth case study research with social purpose ventures in Zambia, Kenya and Mozambique. Cases were selected through a purposive sample with access negotiated to rural BoP communities through gatekeeper partners. Qualitative research methods were primarily employed including interviews, stakeholder focus groups and observational research. Results Six channels through which social purpose ventures contribute to tackling social exclusion amongst rural BoP communities are identified. These include ventures with the BoP as employees, producers, consumers, entrepreneurs, service users and shareholders. A number of shared characteristics for successful social purpose ventures are also outlined. Finally implications for policy, practice and research are discussed. Implications. Despite the increasing attention being given to social purpose ventures as a mechanism for global sustainable development many questions remain unanswered. Limited empirical work has been undertaken on such ventures operating in rural settings in the developing world, particularly Africa. The paper will add to academic and practitioner knowledge in this area especially in relation to up-scaling impact, the long term sustainability and viability of social purpose enterprise ventures, and effective supporting interventions. This paper adds to knowledge in the field of social purpose venturing in the developing world. It identifies various channels through which such ventures help tackle rural social exclusion and also factors influencing their success. The paper provides insights for practitioners and policy makers, particularly in relation to facilitating successful social purpose venturing. Value This paper will provide insights relevant to both academic and practitioner audiences. It addresses a subject area and geographical region that has received limited research attention to date. The paper adds to knowledge on social purpose ventures and social entrepreneurship in Africa and wider developing world environments, and contributes to debates on its potential and present limitations as a vehicle for development and societal transformation

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The analysis step of the (ensemble) Kalman filter is optimal when (1) the distribution of the background is Gaussian, (2) state variables and observations are related via a linear operator, and (3) the observational error is of additive nature and has Gaussian distribution. When these conditions are largely violated, a pre-processing step known as Gaussian anamorphosis (GA) can be applied. The objective of this procedure is to obtain state variables and observations that better fulfil the Gaussianity conditions in some sense. In this work we analyse GA from a joint perspective, paying attention to the effects of transformations in the joint state variable/observation space. First, we study transformations for state variables and observations that are independent from each other. Then, we introduce a targeted joint transformation with the objective to obtain joint Gaussianity in the transformed space. We focus primarily in the univariate case, and briefly comment on the multivariate one. A key point of this paper is that, when (1)-(3) are violated, using the analysis step of the EnKF will not recover the exact posterior density in spite of any transformations one may perform. These transformations, however, provide approximations of different quality to the Bayesian solution of the problem. Using an example in which the Bayesian posterior can be analytically computed, we assess the quality of the analysis distributions generated after applying the EnKF analysis step in conjunction with different GA options. The value of the targeted joint transformation is particularly clear for the case when the prior is Gaussian, the marginal density for the observations is close to Gaussian, and the likelihood is a Gaussian mixture.

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In this article, the authors develop a new measurement scale (the RELQUAL scale) to assess the degree of relationship quality between the exporting firm and the importer. Relationship quality is presented as a high-order concept. Findings reveal that a better quality of the relationship results in a greater (1) amount of information sharing, (2) communication quality, (3) long-term orientation, as well as (4) satisfaction with the relationship. The four multi-item scales show strong evidence of reliability as well as convergent, discriminant and nomological validity in a sample of British exporters. Findings also reveal that relationship quality is positively and significantly associated with export performance. Suggestions for applying the measure in future research are presented.

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Traditional dictionary learning algorithms are used for finding a sparse representation on high dimensional data by transforming samples into a one-dimensional (1D) vector. This 1D model loses the inherent spatial structure property of data. An alternative solution is to employ Tensor Decomposition for dictionary learning on their original structural form —a tensor— by learning multiple dictionaries along each mode and the corresponding sparse representation in respect to the Kronecker product of these dictionaries. To learn tensor dictionaries along each mode, all the existing methods update each dictionary iteratively in an alternating manner. Because atoms from each mode dictionary jointly make contributions to the sparsity of tensor, existing works ignore atoms correlations between different mode dictionaries by treating each mode dictionary independently. In this paper, we propose a joint multiple dictionary learning method for tensor sparse coding, which explores atom correlations for sparse representation and updates multiple atoms from each mode dictionary simultaneously. In this algorithm, the Frequent-Pattern Tree (FP-tree) mining algorithm is employed to exploit frequent atom patterns in the sparse representation. Inspired by the idea of K-SVD, we develop a new dictionary update method that jointly updates elements in each pattern. Experimental results demonstrate our method outperforms other tensor based dictionary learning algorithms.

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Studies of climate change impacts on the terrestrial biosphere have been completed without recognition of the integrated nature of the biosphere. Improved assessment of the impacts of climate change on food and water security requires the development and use of models not only representing each component but also their interactions. To meet this requirement the Joint UK Land Environment Simulator (JULES) land surface model has been modified to include a generic parametrisation of annual crops. The new model, JULES-crop, is described and evaluation at global and site levels for the four globally important crops; wheat, soybean, maize and rice. JULES-crop demonstrates skill in simulating the inter-annual variations of yield for maize and soybean at the global and country levels, and for wheat for major spring wheat producing countries. The impact of the new parametrisation, compared to the standard configuration, on the simulation of surface heat fluxes is largely an alteration of the partitioning between latent and sensible heat fluxes during the later part of the growing season. Further evaluation at the site level shows the model captures the seasonality of leaf area index, gross primary production and canopy height better than in the standard JULES. However, this does not lead to an improvement in the simulation of sensible and latent heat fluxes. The performance of JULES-crop from both an Earth system and crop yield model perspective is encouraging. However, more effort is needed to develop the parametrisation of the model for specific applications. Key future model developments identified include the introduction of processes such as irrigation and nitrogen limitation which will enable better representation of the spatial variability in yield.