Dairy Cow Ownership and Child Nutritional Status in Kenya

This study examines the hypothesis that dairy cow ownership improves child nutritional status. Using household data from coastal and highland Kenya, three econometric model formulations are estimated. Positive impacts on chronic malnutrition are observed for coastal Kenya. No negative effects on acute or chronic malnutrition are found for either region.Food Consumption/Nutrition/Food Safety, Livestock Production/Industries,

Will Small-Scale Dairy Producers in Kenya Disappear Due to Economies of Scale in Production?

There is growing policy concern regarding the competitiveness of small-scale livestock production in the wake of the contemporary livestock revolution in many developing countries. In Kenya, this debate has focused on economies of scale and the undue influence of policy distortions on promoting the scaling up of dairy farms. This paper seeks to investigate economies of scale in Kenyan dairy in terms of relative profit efficiency at different levels of output, and identify policy and technology options to help small-scale farmers develop solutions to the challenges of competition. Data were collected from 204 dairy producers of different farm sizes in rural Kiambu and Thika, and urban Nairobi districts and a stochastic frontier model approach was used to analyze the determinants of profitability and inefficiency. Unit profitability per farm ranged between US$0.13 - US$0.16 per liter of milk with no significant variation across scales of farm. However, at all given levels of scale of farm, inefficiency significantly contributed to variability in profitability across farms. Scale had no significant effect on efficiency, confirming the relative competitiveness of small-scale dairy producers. Dairy farmers with commercial poultry achieved higher relative profit efficiency as poultry waste was fed to cattle. Rural location relative to Nairobi also increased efficiency. Linking rural areas and major market centre with good roads, strengthening of farmers' co-operative societies and exploring use of cheaper raw materials in the manufacture of concentrate feeds may strengthen the competitive position small dairy farms versus large ones.Dairy Production, Stochastic Production Frontier, Efficiency, Profitability, Livestock Production/Industries, C21, Q12,

How motifs condition critical thresholds for tipping cascades in complex networks: Linking Micro- to Macro-scales

In this study, we investigate how specific micro interaction structures (motifs) affect the occurrence of tipping cascades on networks of stylized tipping elements. We compare the properties of cascades in Erd\"os-R\'enyi networks and an exemplary moisture recycling network of the Amazon rainforest. Within these networks, decisive small-scale motifs are the feed forward loop, the secondary feed forward loop, the zero loop and the neighboring loop. Of all motifs, the feed forward loop motif stands out in tipping cascades since it decreases the critical coupling strength necessary to initiate a cascade more than the other motifs. We find that for this motif, the reduction of critical coupling strength is 11% less than the critical coupling of a pair of tipping elements. For highly connected networks, our analysis reveals that coupled feed forward loops coincide with a strong 90% decrease of the critical coupling strength. For the highly clustered moisture recycling network in the Amazon, we observe regions of very high motif occurrence for each of the four investigated motifs suggesting that these regions are more vulnerable. The occurrence of motifs is found to be one order of magnitude higher than in a random Erd\"os-R\'enyi network. This emphasizes the importance of local interaction structures for the emergence of global cascades and the stability of the network as a whole

Agroindustrialization through institutional innovation

Some small-holders are able to generate reliable and substantial income flows through small-scale dairy production for the local market; for others, a set of unique transactions costs hinders participation. Cooperative selling institutions are potential catalysts for mitigating these costs, stimulating entry into the market, and precipitating growth in rural communities. Trends in cooperative organization in East-African dairy are evaluated. Empirical work focuses on alternative techniques for effecting participation among a representative sample of peri-urban milk producers in the Ethiopian highlands. The techniques considered are a modern production practice (cross-bred cow use), a traditional production practice (indigenous-cow use), three intellectual-capital-forming variables (experience, education, extension), and the provision of infrastructure (as measured by time to transport milk to market). A Tobit analysis of marketable surplus generates precise estimates of non-participants' ‘distances' to market and their reservation levels of the covariates—measures of the inputs necessary to sustain and enhance the market. Policy implications focus on the availability of cross-bred stock and the level of market infrastructure, both of which have marked effects on participation, the velocity of transactions in the local community and, inevitably, the social returns to agroindustrialization.Dairy farming Ethiopia. ,Collective farms Ethiopia. ,

The Generosity of Artificial Languages

A revolution in language heralded the birth of modern science. Latin was replaced by formal languages, such as algebra, born of artificial notations and practical devices like new numerals. Frits Staal argues that some of the roots of that revolution lie in Asia

Dynamics of Tipping Cascades on Complex Networks

Tipping points occur in diverse systems in various disciplines such as ecology, climate science, economy or engineering. Tipping points are critical thresholds in system parameters or state variables at which a tiny perturbation can lead to a qualitative change of the system. Many systems with tipping points can be modeled as networks of coupled multistable subsystems, e.g. coupled patches of vegetation, connected lakes, interacting climate tipping elements or multiscale infrastructure systems. In such networks, tipping events in one subsystem are able to induce tipping cascades via domino effects. Here, we investigate the effects of network topology on the occurrence of such cascades. Numerical cascade simulations with a conceptual dynamical model for tipping points are conducted on Erd\H{o}s-R\'enyi, Watts-Strogatz and Barab\'asi-Albert networks. Additionally, we generate more realistic networks using data from moisture-recycling simulations of the Amazon rainforest and compare the results to those obtained for the model networks. We furthermore use a directed configuration model and a stochastic block model which preserve certain topological properties of the Amazon network to understand which of these properties are responsible for its increased vulnerability. We find that clustering and spatial organization increase the vulnerability of networks and can lead to tipping of the whole network. These results could be useful to evaluate which systems are vulnerable or robust due to their network topology and might help to design or manage systems accordingly.Comment: 22 pages, 12 figure

Targeting HCV Entry For Development of Therapeutics

Recent progress in defining the molecular mechanisms of Hepatitis C Virus (HCV) entry affords the opportunity to exploit new viral and host targets for therapeutic intervention. Entry inhibitors would limit the expansion of the infected cell reservoir, and would complement the many replication inhibitors now under development. The current model for the pathway of entry involves the initial docking of the virus onto the cell surface through interactions of virion envelope and associated low density lipoproteins (LDL) with cell surface glycosaminoglycans and lipoprotein receptors, followed by more specific utilization with other hepatocyte membrane proteins: Scavenger Receptor Class B type 1 (SR-BI), CD81, Claudin 1 (CLDN1) and Occludin (OCLN). The use of blockers of these interactions, e.g. specific antibodies, suggests that inhibition of any one step in the entry pathway can inhibit infection. Despite this knowledge base, the tools for compound screening, HCV pseudoparticles (HCVpp) and cell culture virus (HCVcc), and the ability to adapt them to industrial use are only recently available and as a result drug discovery initiatives are in their infancy. Several therapies aiming at modulating the virus envelope to prevent host cell binding are in early clinical testing. The first test case for blocking a cellular co-receptor is an SR-BI modulator. ITX 5061, an orally active small molecule, targets SR-BI and has shown potent antiviral activity against HCVpp and HCVcc. ITX 5061 has exhibited good safety in previous clinical studies, and is being evaluated in the clinic in chronic HCV patients and patients undergoing liver transplantation. Entry inhibitors promise to be valuable players in the future development of curative therapy against HCV

Reliability of the Multidimensional Pain Inventory and stability of the MPI classification system in chronic back pain

Contains fulltext : 109346.pdf (publisher's version ) (Open Access)ABSTRACT: BACKGROUND: This cross validation study examined the reliability of the Multidimensional Pain Inventory (MPI) and the stability of the Multidimensional Pain Inventory Classification System of the empirically derived subgroup classification obtained by cluster analysis in chronic musculoskeletal pain. Reliability of the German Multidimensional Pain Inventory was only examined once in the past in a small sample. Previous international studies mainly involving fibromyalgia patients showed that retest resulted in 33-38% of patients being assigned to a different Multidimensional Pain Inventory subgroup classification. METHODS: Participants were 204 persons with chronic musculoskeletal pain (82% chronic non-specific back pain). Subgroup classification was conducted by cluster analysis at 4 weeks before entry (=test) and at entry into the pain management program (=retest) using Multidimensional Pain Inventory scale scores. No therapeutic interventions in this period were conducted. Reliability was quantified by intraclass correlation coefficients (ICC) and stability by kappa coefficients (kappa). RESULTS: Reliability of the Multidimensional Pain Inventory scales was least with ICC = 0.57 for the scale life control and further ranged from ICC = 0.72 (negative mood) to 0.87 (solicitous responses) in the other scales. At retest, 82% of the patients in the Multidimensional Pain Inventory cluster interpersonally distressed (kappa = 0.69), 80% of the adaptive copers (kappa = 0.58), and 75% of the dysfunctional patients (kappa = 0.70) did not change classification. In total, 22% of the patients changed Multidimensional Pain Inventory cluster group, mainly into the adaptive copers subgroup. CONCLUSION: Test-retest reliability of the German Multidimensional Pain Inventory was moderate to good and comparable to other language versions. Multidimensional Pain Inventory subgroup classification is substantially stable in chronic back pain patients when compared to other diagnostic groups and other examiner-based subgroup Classification Systems. The MPI Classification System can be recommended for reliable and stable specification of subgroups in observational and interventional studies in patients with chronic musculoskeletal pain