Recognizing and realizing the potential of organic agriculture in Kenya

Formal organic agriculture in Kenya dates back to the early eighties when the first pioneer organic training institutions were established. During the same period, a few horticultural companies started growing organic vegetables for export. Initial efforts to promote organic agriculture in Kenya were made by rural development non-governmental organizations (NGOs), faith based organizations and community based organizations (CBOs). They seek to help rural farmers in addressing the issue of declining agricultural productivity (especially the degradation of soils and natural resource base), high poverty incidences, food insecurity and low incomes which pre-vented farmers from assessing high costs inputs. Currently Kenya has five major players in organic agriculture namely Kitale-based Manor House Agricultural Center, Baraka College in Molo, the Sustainable Agriculture Community Development Pro-gram in Thika, the Kenya Institute of Organic Farming (KIOF), a training center on the outskirts Kenya’s capital Nairobi, and the Association for Better Land Husbandry (ABLH), headquartered in Nairobi. The organic sector is relatively small; however, it is growing very fast, led mainly by NGOs and private sector (companies growing organic produce for export). Exports of organic products have been taking place for the last two decades, mainly with vegetables and fruits produced on large scale farms. Over the years exports have developed beyond vegetables and fruits to include other prod-ucts such as essential oils, dried herbs and spices as well as products for the cos-metic and pharmaceutical industries which are more often produced by smallholders. Currently, there are five international certifiers operating in Kenya, namely: the Soil Association (SA), EcoCert International; IMO (Institute for Market Ecology); USDA’s (United States Department of Agriculture) National Organic Programme (NOP) and Bio Suisse

Ökologischer Kreislauf Moorbad Harbach: Life Cycle Assessment (LCA) for Agricultural Plant Production and Transportation

In 1992 the community of Moorbad Harbach (Austria), located near the border of the Czech Republic and dominated by extensive agricultural practice on small scale farms, decided to initiate activities for regional devolopment. About 40 farms (27 %) converted to organic farming, a local marketing service as well as regional food processing businesses (slaughterhouse, dairy), operating as linkages between regional agriculture and the local spa hotel were founded. The basic idea for the work presented here was to evaluate the – especially ecological – consequences of such a regional conversion. One part of this attempt of evaluation was carried out as a LCA for the agricultural production in Moorbad Harbach. The emphasis of the study was to compare plant production before and after the regional conversion to organic farming. In another step changes in transportation distances and quantities with special regard to transport of raw milk and milk products were quantified

Conditional and constitutive expression of a Tbx1-GFP fusion protein in mice.

BACKGROUND: Velo-cardio-facial syndrome/DiGeorge syndrome (VCFS/DGS) is caused by a 1.5-3 Mb microdeletion of chromosome 22q11.2, frequently referred to as 22q11.2 deletion syndrome (22q11DS). This region includes TBX1, a T-box transcription factor gene that contributes to the etiology of 22q11DS. The requirement for TBX1 in mammalian development is dosage-sensitive, such that loss-of-function (LOF) and gain-of-function (GOF) of TBX1 in both mice and humans results in disease relevant congenital malformations. RESULTS: To further gain insight into the role of Tbx1 in development, we have targeted the Rosa26 locus to generate a new GOF mouse model in which a Tbx1-GFP fusion protein is expressed conditionally using the Cre/LoxP system. Tbx1-GFP expression is driven by the endogenous Rosa26 promoter resulting in ectopic and persistent expression. Tbx1 is pivotal for proper ear and heart development; ectopic activation of Tbx1-GFP in the otic vesicle by Pax2-Cre and Foxg1-Cre represses neurogenesis and produces morphological defects of the inner ear. Overexpression of a single copy of Tbx1-GFP using Tbx1Cre/+ was viable, while overexpression of both copies resulted in neonatal lethality with cardiac outflow tract defects. We have partially rescued inner ear and heart anomalies in Tbx1Cre/- null embryos by expression of Tbx1-GFP. CONCLUSIONS: We have generated a new mouse model to conditionally overexpress a GFP-tagged Tbx1 protein in vivo. This provides a useful tool to investigate in vivo direct downstream targets and protein binding partners of Tbx1

Dusty Wind-Blown Bubbles

Spurred by recent observations of 24 micron emission within wind-blown bubbles, we study the role that dust can play in such environments, and build an approximate model of a particular wind-blown bubble, `N49.' First, we model the observations with a dusty wind-blown bubble, and then ask whether dust could survive within N49 to its present age (estimated to be 5x10^5 to 10^6 years). We find that dust sputtering and especially dust-gas friction would imply relatively short timescales (t ~ 10^4 years) for dust survival in the wind-shocked region of the bubble. To explain the 24 micron emission, we postulate that the grains are replenished within the wind-blown bubble by destruction of embedded, dense cloudlets of ISM gas that have been over-run by the expanding wind-blown bubble. We calculate the ablation timescales for cloudlets within N49 and find approximate parameters for the embedded cloudlets that can replenish the dust; the parameters for the cloudlets are roughly similar to those observed in other nebula. Such dust will have an important effect on the bubble: including simple dust cooling in a wind-blown bubble model for N49, we find that the luminosity is higher by approximately a factor of six at a bubble age of about 10^4 years. At ages of 10^7 years, the energy contained in the bubble is lower by about a factor of eight if dust is included; if dust must be replenished within the bubble, the associated accompanying gas mass will also be very important to wind-blown bubble cooling and evolution. While more detailed models are certainly called for, this work illustrates the possible strong importance of dust in wind-blown bubbles, and is a first step toward models of dusty, wind-blown bubbles.Comment: 13 pages, 14 figures, Accepted to Ap

Child Sexual Abuse Prevention Programs: What Makes Them Effective in Protecting Children?

Child sexual abuse prevention programs have proliferated over the past several years. Many of these program approaches, which include plays, games and videos, are visually appealing and highly entertaining, and parents and teachers have widely embraced them. However, despite the popularity of such programs, little effort has been made to evaluate their effectiveness in changing children's behavior. As a result of participation in a sexual abuse prevention program, has a child's vulnerability to abuse been reduced, for example, or has his or her sense of personal safety been enhanced

Auswirkungen unterschiedlicher Vorfruchtkombinationen aus Haupt- und Zwischenfrucht auf Ertrag und Auftreten von Schaderregern im ökologischen Kartoffelbau

Durch einen geeigneten Hauptfrucht-/Zwischenfruchtanbau kann über die Anreicherung von Stickstoff und Pflanzenbiomasse im Boden als wesentliche Komponenten des vorbeugenden Pflanzenschutzes neben dem Ertrag auch die Kartoffelgesundheit und damit die Knollenqualität beeinflusst werden. Das Hauptziel des Projekts ist es demnach festzustellen, welche Vorfruchtkombination aus Haupt- und Zwischenfrüchten geeignet ist, gesunde und qualitativ wie quantitativ ansprechende Kartoffelerträge, zu erzielen. Es werden in einem Feldversuch auf Flächen der Fachschule Edelhof im Waldviertel insgesamt vier Hauptfrucht-Zwischenfruchtvarianten hinsichtlich ihrer Wirkung auf den Schaderregerbefall, die Qualität und den Ertrag von Kartoffel (1. Nachfrucht) und auf den Ertrag und die Qualität von Winterweizen (2. Nachfrucht) in jeweils vierfacher Wiederholung geprüft. Je Fruchtfolgevariante werden drei Kartoffelsorten angebaut. Es werden die Stickstoffdynamik und die bodenbiologische Aktivität bestimmt, und die Wirtschaftlichkeit der verschiedenen Verfahren bewertet

Interplay between distribution of live cells and growth dynamics of solid tumours

Experiments show that simple diffusion of nutrients and waste molecules is not sufficient to explain the typical multilayered structure of solid tumours, where an outer rim of proliferating cells surrounds a layer of quiescent but viable cells and a central necrotic region. These experiments challenge models of tumour growth based exclusively on diffusion. Here we propose a model of tumour growth that incorporates the volume dynamics and the distribution of cells within the viable cell rim. The model is suggested by in silico experiments and is validated using in vitro data. The results correlate with in vivo data as well, and the model can be used to support experimental and clinical oncology

When the optimal is not the best: parameter estimation in complex biological models

Background: The vast computational resources that became available during the past decade enabled the development and simulation of increasingly complex mathematical models of cancer growth. These models typically involve many free parameters whose determination is a substantial obstacle to model development. Direct measurement of biochemical parameters in vivo is often difficult and sometimes impracticable, while fitting them under data-poor conditions may result in biologically implausible values. Results: We discuss different methodological approaches to estimate parameters in complex biological models. We make use of the high computational power of the Blue Gene technology to perform an extensive study of the parameter space in a model of avascular tumor growth. We explicitly show that the landscape of the cost function used to optimize the model to the data has a very rugged surface in parameter space. This cost function has many local minima with unrealistic solutions, including the global minimum corresponding to the best fit. Conclusions: The case studied in this paper shows one example in which model parameters that optimally fit the data are not necessarily the best ones from a biological point of view. To avoid force-fitting a model to a dataset, we propose that the best model parameters should be found by choosing, among suboptimal parameters, those that match criteria other than the ones used to fit the model. We also conclude that the model, data and optimization approach form a new complex system, and point to the need of a theory that addresses this problem more generally

Enrollment of adolescents and young adults onto SWOG cancer research network clinical trials: A comparative analysis by treatment site and era.

BackgroundFew adolescents and young adults (AYAs, 15-39 years old) enroll onto cancer clinical trials, which hinders research otherwise having the potential to improve outcomes in this unique population. Prior studies have reported that AYAs are more likely to receive cancer care in community settings. The National Cancer Institute (NCI) has led efforts to increase trial enrollment through its network of NCI-designated cancer centers (NCICC) combined with community outreach through its Community Clinical Oncology Program (CCOP; replaced by the NCI Community Oncology Research Program in 2014).MethodsUsing AYA proportional enrollment (the proportion of total enrollments who were AYAs) as the primary outcome, we examined enrollment of AYAs onto SWOG therapeutic trials at NCICC, CCOP, and non-NCICC/non-CCOP sites from 2004 to 2013 by type of site, study period (2004-08 vs 2009-13), and patient demographics.ResultsOverall, AYA proportional enrollment was 10.1%. AYA proportional enrollment decreased between 2004-2008 and 2009-2013 (13.1% vs 8.5%, P < .001), and was higher at NCICCs than at CCOPs and non-NCICC/non-CCOPs (14.1% vs 8.3% and 9.2%, respectively; P < .001). AYA proportional enrollment declined significantly at all three site types. Proportional enrollment of AYAs who were Black or Hispanic was significantly higher at NCICCs compared with CCOPs or non-NCICC/non-CCOPs (11.5% vs 8.8, P = .048 and 11.5% vs 8.6%, P = .03, respectively).ConclusionNot only did community sites enroll a lower proportion of AYAs onto cancer clinical trials, but AYA enrollment decreased in all study settings. Initiatives aimed at increasing AYA enrollment, particularly in the community setting with attention to minority status, are needed