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OALib Journal期刊

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Assessment of Soil Nutrients Limiting Sustainable Potato Production in the Highlands of South-Western Uganda  [PDF]
Robert Muzira, Twaha Basamba, John Steven Tenywa
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104440
Abstract:
Soil fertility management is one of the major strategies for improving potato productivity in the highlands of south-western Uganda. Land belonging to potato farmers is highly fragmented hindering sustainable potato production under small-holder farming systems. Land fragmentation brings a major challenge to small-scale farmers in soil fertility management, increasing costs of production. However, identifying major soil nutrients limiting potato production in the highlands of south-western Uganda is an avenue of applying appropriate soil nutrients to improve potato productivity without degrading the soils. It also assists farmers in investing in the necessary soil nutrients and, hence reducing the costs of production while improving potato productivity. The study indicated that soil potassium was the most single significant soil nutrient limiting potato productivity especially in the fields located on hilltops and far from homesteads. Hence, it was imperative that farmers apply potassium containing fertilizers to minimize potassium depletion but also increase potato productivity. It was also important for farmers to always integrate disease management with soil nutrient management for improved potato productivity.
Linking Soil Conservation in Potato Production Systems in the Highlands of Southwestern Uganda to Gender and Farmer-Market Types  [PDF]
Robert Muzira, John Steven Tenywa, Twaha Basamba
Open Access Library Journal (OALib Journal) , 2018, DOI: 10.4236/oalib.1104422
Abstract:
Rural communities in sub-Saharan Africa develop different livelihood strategies driven by opportunities and constraints encountered in existing biophysical and socioeconomic environments. A study on gender effects under two market linkages on investments in soil conservation innovations in potato production systems was conducted in the highlands of southwestern Uganda. There were significant differences in land size under fallow belonging to Male Headed Households (MHHs) and Female Headed Households (FHHs) with urban and non-urban market linkages (p < 0.05). None the less both FHHs and MHHs had more land under fallow. This was attributed to the trainings farmers obtained in the control of bacterial wilt of potato through integrating fallow period in the potato cropping systems. Under urban and non-urban market linkages, there were no significant differences in percentage distribution of potato fields for MHHs and FHHs without soil conservation structure (p > 0.05). This was attributed to limited land holdings owned by farmers that are intensively cultivated.
Facilitating Farmer-Market Linkages Increased Adoption of Maize Technology in Chahi, Southwestern Uganda
Moses Tenywa,Bernard Fungo
Agricultural Journal , 2013, DOI: 10.3923/aj.2011.201.206
Abstract: This study was carried out to establish the impact of facilitating farmers access to market on adoption of maize cultivation, associated land management practices, identify the major constraints to and socio-economic determinants of adoption in Chahi sub county, Kisoro district, Southwestern Uganda. An Innovation Platform (IP) established to facilitate stakeholder participation in overcoming critical constraints of a potato value-chain was used to promote maize cultivation following exciting experience from potatoes. Data were collected from 180 households in ten participating villages of Chahi sub county. Results show that the number of maize farmers increased from 10-35% while the average maize acreage per household increased from 1.3-2.7 ha. There is also increased use or inorganic fertilizers and more careful treatment of household refuse as manure to improve soil fertility in the maize gardens. The difficulty of acquiring seed, long distance to the maize collection center and lack of knowledge of quality seed are the major constraints facing the maize farmers. Membership to IP, land holding and education level are the household characteristics that influence adoption of the maize technology in Chahi sub county. It is recommended that the IP facilitates linkages with suppliers of quality seed for farmers. Establishing several collection centers for harvested maize would reduce the burden of farmers having to transport maize to the far-off market areas.
Electronic Commerce: A Taxing Dilemma
Steven John Simon
Informing Science The International Journal of an Emerging Transdiscipline , 2002,
Abstract: In the last five years, remote selling-led by online organizations - has surged. The resulting growth has created concern among both traditional and remote sellers as they jockey for improved competitive position and governmental entities, in particular US states, over the erosion of their tax revenues as sales are diverted to remote sellers. This paper explores the issues and potential solutions surrounding the e-commerce tax dilemma. It provides a current assessment of the taxation environment for individuals and organizations impacted by the tax debate. Those individuals and organizations might include online business customers, remote sellers both traditional (mail order) and online, tax equity organizations, and governmental bodies. Current tax obligations are explored based on landmark legal decisions. Potential short and long -term solutions are assessed.
Neonatology Specialty Grand Challenge
John Steven Torday
Frontiers in Pediatrics , 2013, DOI: 10.3389/fped.2013.00013
Abstract:
Chordal Coxeter Groups
John Ratcliffe,Steven Tschantz
Mathematics , 2006,
Abstract: A solution of the isomorphism problem is presented for the class of Coxeter groups W that have a finite set of Coxeter generators S such that the underlying graph of the presentation diagram of the system (W,S) has the property that every cycle of length at least four has a cord. As an application, we construct counterexamples to two main conjectures concerning the isomorphism problem for Coxeter groups.
JSJ decompositions of Coxeter groups over FA subgroups
John Ratcliffe,Steven Tschantz
Mathematics , 2009,
Abstract: A group G has property FA if G fixes a point of every tree on which G acts without inversions. We prove that every Coxeter system of finite rank has a visual JSJ decomposition over subgroups with property FA. As an application, we reduce the twist conjecture to Coxeter systems that are indecomposable with respect to amalgamated products over visual subgroups with property FA.
Computing zeta functions of sparse nondegenerate hypersurfaces
Steven Sperber,John Voight
Computer Science , 2011, DOI: 10.1112/S1461157012001179
Abstract: Using the cohomology theory of Dwork, as developed by Adolphson and Sperber, we exhibit a deterministic algorithm to compute the zeta function of a nondegenerate hypersurface defined over a finite field. This algorithm is particularly well-suited to work with polynomials in small characteristic that have few monomials (relative to their dimension). Our method covers toric, affine, and projective hypersurfaces and also can be used to compute the L-function of an exponential sum.
Warm C2H2 toward NGC 7538 IRS9: Grain Surface Origin  [PDF]
Steven D. Doty, Sandra L. Doty, Jeff Cochran, John Lacy, John Barentine, Richard Field
International Journal of Astronomy and Astrophysics (IJAA) , 2014, DOI: 10.4236/ijaa.2014.43044
Abstract:

We consider models for the observed ro-vibrational absorption lines of acetylene toward NGC 7538 IRS9. The data are fit with multiple screens, each having separate column densities, rotational and vibrational excitation temperatures, and filling factors. The best fit was determined using a chi-squared minimization scheme. We find that only one screen is necessary—multiple screens gave rise to either making one of the screens transparent, or very occasionally making the two screens the same. As a result, we can place constraints on Trot, Tvib, NC2H2, and the filling factor, f. In particular we find 0.03 < f < 0.3 with a best fit of f ~ 0.1. We also find Tvib < 200 K, with a best fit of Tvib < 20 K. We find NC2H2 = 2.4 +/- 0.6 × 1016 cm-2, or that N × f ~ 2 × 1015

The Unique Structural Parameters of the Underlying Host Galaxies in Blue Compact Dwarfs
Steven Janowiecki,John J. Salzer
Physics , 2014, DOI: 10.1088/0004-637X/793/2/109
Abstract: The nature of possible evolutionary pathways between various types of dwarf galaxies is still not fully understood. Blue compact dwarf galaxies (BCDs) provide a unique window into dwarf galaxy formation and evolution and are often thought of as an evolutionary stage between different classes of dwarf galaxies. In this study we use deep optical and near-infrared observations of the underlying hosts of BCDs in order to study the structural differences between different types of dwarf galaxies. When compared with dwarf irregular galaxies of similar luminosities, we find that the underlying hosts of BCDs have significantly more concentrated light distributions, with smaller scale lengths and brighter central surface brightnesses. We demonstrate here that the underlying hosts of BCDs are distinct from the broad continuum of typical dwarf irregular galaxies, and that it is unlikely that most dwarf irregular galaxies can transform into a BCD or vice versa. Furthermore, we find that the starburst in a BCD only brightens it on average by ~0.8 mag (factor of two), in agreement with other studies. It appears that a BCD is a long-lived and distinct type of dwarf galaxy that exhibits an exceptionally concentrated matter distribution. We suggest that it is this compact mass distribution that enables the strong star formation events that characterize this class of dwarf galaxy, that the compactness of the underlying host can be used as a distinguishing parameter between BCDs and other dwarf galaxies, and that it can also be used to identify BCDs which are not currently experiencing an intense starburst event.
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