Improving Kenya's Domestic Horticultural Production and Marketing System: Current Competitiveness, Forces of Change, and Challenges for the Future (Volume II: Horticultural Marketing)

The specific objectives of this Volume are to: estimate the share of domestic FFV production going to international and domestic markets; determine the share of imports from Tanzania and Uganda in Kenya’s horticultural markets; investigate the competitiveness of Kenya’s horticultural produce in local and regional markets; determine the current and likely future share of key marketing channels in Kenya’s domestic FFV marketing system, especially “modern” channels such as supermarkets and more traditional channels such as open air markets and kiosks; and recommend steps that should be taken to place Kenya’s domestic horticulture in a position to compete favorably in local and regional markets.Food Security, Food Policy, Horticultural Marketing, Kenya, Crop Production/Industries, Q18,

Continuous, Pulsed and Disrupted Nutrient Subsidy Effects on Ecosystem Productivity, Stability, and Energy Flow

Resource pulses and subsidies can supply ecosystems with an important source of nutrients that supports additional productivity at multiple trophic levels. Common carp Cyprinus carpio provide ecosystems with a continuous nutrient subsidy through bioturbation and excretion but may also initiate a nutrient pulse through carcass decomposition. We examined how continuous (common carp foraging and excretion), pulsed (carcass decomposition) and disrupted (carp introduced and then removed) nutrient subsidies differed in their ability to alter nutrient availability, ecosystem productivity and stability and energy flow. Nitrogen and phosphorus availability and primary production were highest in pulsed, intermediate in continuous and lowest for disrupted and control systems. Continuous, and to a lesser extent pulsed, systems were associated with decreased water clarity and macrophyte coverage. Nutrient pulses ascended to higher trophic levels and supported greater densities of consumers (i.e., zooplankton and macroinvertebrates). Biotic and abiotic responses in disrupted systems quickly returned to control levels and water quality improved. Light penetration and Daphnia spp. dynamics were more stable in systems with pulses whereas stability of other variables was similar across treatments. Biotic materials collected from pulsed and continuous subsidy systems were typically enriched in δ15N suggesting common carp-derived nutrients supported increased productivity whereas δ13C signatures were depleted suggesting a transition to more pelagic energy pathways, likely due to enhanced phytoplankton production. Our results suggest that continuous and pulsed nutrient subsidies vary in their ability to support and sustain ecosystem productivity with resulting variation in food web structure and ecosystem stability

Representative Characteristics of Rural Households in Areas of Central and Southern Mozambique Affected by the 2000 Floods

Ministry of Agriculture and Rural Development, Directorate of Economics, Republic of Mozambiquefood security, food policy, Mozambique, rural households, Food Security and Poverty, Q18,

Representative Characteristics of Rural Households in Areas of Central and Southern Mozambique Affected by the 2000 Floods

Research Results from the Department of Policy Analysis MADR-Directorate of Economicsfood security, food policy, Mozambique, rural household, Community/Rural/Urban Development, Q18,

Where Do Consumers in Nairobi Purchase their Food and Why Does this Matter? The Need for Investment to Improve Kenya's "Traditional" Food Marketing System

Published by Tegemeo Institute for Agricultural Policy and Developmentfood security, food policy, Kenya, food marketing system, Food Consumption/Nutrition/Food Safety, Q18,

Notes and Discussion Piece: Status of the Topeka Shiner in Iowa

The Topeka shiner Notropis topeka is native to Iowa, Kansas, Minnesota, Missouri, Nebraska, and South Dakota and has been federally listed as endangered since 1998. Our goals were to determine the present distribution and qualitative status of Topeka shiners throughout its current range in Iowa and characterize the extent of decline in relation to its historic distribution. We compared the current (2016–2017) distribution to distributions portrayed in three earlier time periods. In 2016–2017 Topeka shiners were found in 12 of 20 HUC10 watersheds where they occurred historically. Their status was classified as stable in 21% of the HUC10 watersheds, possibly stable in 25%, possibly recovering in 8%, at risk in 33%, and possibly extirpated in 13% of the watersheds. The increasing trend in percent decline evident in earlier time periods reversed, going from 68% in 2010–11 to 40% in the most recent surveys. Following decades of decline, the status of Topeka shiners in Iowa appears to be improving. One potential reason for the reversal in the distributional decline of Topeka shiners in Iowa is the increasing number of oxbow restorations. Until a standardized monitoring program is established for Iowa, periodic status assessments such as this will be necessary to chronicle progress toward conserving this endangered fish species

The host galaxies of strong CaII QSO absorption systems at z<0.5

We present new imaging and spectroscopic observations of the fields of five QSOs with very strong intervening CaII absorption systems at redshifts z<0.5 selected from the Sloan Digital Sky Survey. Recent studies of these very rare absorbers indicate that they may be related to damped Lyman alpha systems (DLAs). In all five cases we identify a galaxy at the redshift of the CaII system with impact parameters up to ~24 kpc. In four out of five cases the galaxies are luminous (L ~L*), metal-rich (Z ~Zsun), massive (velocity dispersion, sigma ~100 km/s) spirals. Their star formation rates, deduced from Halpha emission, are high, in the range SFR = 0.3 - 30 Msun/yr. In our analysis, we paid particular attention to correcting the observed emission line fluxes for stellar absorption and dust extinction. We show that these effects are important for a correct SFR estimate; their neglect in previous low-z studies of DLA-selected galaxies has probably led to an underestimate of the star formation activity in at least some DLA hosts. We discuss possible links between CaII-selected galaxies and DLAs and outline future observations which will help clarify the relationship between these different classes of QSO absorbers.Comment: Accepted for publication in MNRAS, 14 pages, 9 figures. Version with full resolution images available at http://www.ast.cam.ac.uk/~bjz/papers/Zych_etal_2007a.pd

Complementarity of Resonant Scalar, Vector-Like Quark and Superpartner Searches in Elucidating New Phenomena

The elucidation of the nature of new phenomena requires a multi-pronged approach to understand the essential physics that underlies it. As an example, we study the simplified model containing a new scalar singlet accompanied by vector-like quarks, as motivated by the recent diphoton excess at the LHC. To be specific, we investigate three models with $SU(2)_L$-doublet, vector-like quarks with Yukawa couplings to a new scalar singlet and which also couple off-diagonally to corresponding Standard Model fermions of the first or third generation through the usual Higgs boson. We demonstrate that three classes of searches can play important and complementary roles in constraining this model. In particular, we find that missing energy searches designed for superparticle production, supply superior sensitivity for vector-like quarks than the dedicated new quark searches themselves.Comment: References added; small bug found in model and analysis implementation, numerical results slightly modified, conclusions unchange