Carsey Perspectives: Meeting Farmers Where They Are, Increasing Agricultural Sustainability in Malawi Through Business Format Franchising

In this perspectives brief, authors Ilona Drew, Abraham DeMaio, Bill Maddocks, and Fiona Wilson discuss a case study that was examined as part of the Social Sector Franchise Initiative (SSFI), a project of the Center for Social Innovation and Enterprise at the University of New Hampshire. This case study profiles Ziweto Enterprises, a social venture in Malawi using franchising methodology to scale its growth. Ziweto’s Agrovet Shops are “one-stop” franchised shops run by recent graduates of veterinary medicine and agricultural colleges that offer diverse veterinary and agricultural products and services. Ziweto’s products and services provide key support to the nation’s smallholder farmers, supporting animal husbandry as well as crop output

Which Chessboards have a Closed Knight\u27s Tour within the Cube?

A closed knight\u27s tour of a chessboard uses legal moves of the knight to visit every square exactly once and return to its starting position. When the chessboard is translated into graph theoretic terms the question is transformed into the existence of a Hamiltonian cycle. There are two common tours to consider on the cube. One is to tour the six exterior n x n boards that form the cube. The other is to tour within the n stacked copies of the n x n board that form the cube. This paper is concerned with the latter. In this paper necessary and sufficient conditions for the existence of a closed knight\u27s tour for the cube are proven

Using Dendrochronology to Understand the Response of Eastern Hemlock to Past Stresses and its Current Status in Southern Maine

Eastern hemlock (Tsuga canadensis (L.) Carr.) is an ecologically important species that is threatened across its range by the non-native hemlock woolly adelgid (HWA, Adelges tsugae (Annand) (Hemiptera: Adelgidae)). In order to understand potential impacts of HWA in southern Maine, we conducted a treering study of 36 sites in southern Maine (York and Cumberland counties) to evaluate how stress events affected eastern hemlock increments, especially after the 1999-2002 drought. The primary objectives were to: 1) create a master chronology and identify reduced growth events 2) model abiotic factors associated with differences in drought response among plots and 3) evaluate the impact of the 1999-2002 drought on growth trends across the southern Maine hemlock population. Reduced growth events coincided with records of drought and defoliation by hemlock looper (Lambdina fiscellaria (GUEN.) and gypsy moth Lymantria dispar (L.). Hemlock growth for the master chronology was also associated with 1) previous year’s June and July temperatures, 2) both previous and current summer precipitation, and 3) both maximum and minimum February temperatures. A predictive model for the 2003 drought year showed that plots with higher expressed population signals (and adjustment of interseries correlation for sample size), shallower O soil horizons, lower average February maximum temperatures, higher B soil horizon aluminum saturation, and greater stand densities had the largest decreases in mean growth, as expressed by the percent growth change of increments over a 3 year period. The plots with the most negative percent growth change in 2003 had the most positive percent growth change in 2005. The 2005 recovery was positively related to average plot age and calcium in the B soil horizon. The low number of trees (59 of 503) experiencing decreased growth in 2005 supports the observation from the master chronology that hemlock trees in this study are typically healthy and able to quickly recover following drought stress. These findings support the consideration of management strategies that increase hemlock vigor leading to greater growth potential and enhanced ability of trees to recover from stres

Diversity and composition of cactus species along an altitudinal gradient in the Sierras del Norte Mountains (Córdoba, Argentina)

Cacti are important elements of the flora in many ecosystems of the Americas. However, the factors that determine their richness and composition are not well known, particularly at the regional scale. The aim of this work was to study the patterns of cactus richness (both species and growth forms) and composition in the Sierras del Norte mountain range (Córdoba Province, Argentina). Species presence was recorded at 55 sites covering an altitudinal gradient from 203 to 970 m. Twenty four species from eight genera were recorded in the area. Total species richness and growth form richness decreased with increasing altitude. The richness of columnar and short columnar species decreased with increasing altitude, whereas richness of globose species increased. Opuntioid richness did not respond to altitude. Species composition was strongly related to altitude. Gymnocalycium bruchii and Parodia erinacea occurred at sites located at higher altitudes, whereas at sites at lower altitudes, Gymnocalycium schickendantzii, Stetsonia coryne and Cleistocactus baumannii, among other species, were present. Our results highlight the importance of altitude in shaping the distribution of species and growth forms in the Sierras del Norte Mountains.Fil: Gurvich, Diego Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Zeballos, Sebastián Rodolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Demaio, Pablo Horacio. NGO Ecosistemas Argentinos; Argentin