557 research outputs found
Factors influencing adoption of agroforestry among smallholder farmers in Zambia
Agroforestry technologies have been extensively researched and introduced to smallholder farmers in Zambia for over two decades. Despite the research and extension effort over this period, not many farmers have adopted these technologies. The purpose of this paper is to determine why agroforestry technologies are not being taken up by examining factors that influence the adoption of agroforestry practices. Based on data obtained from 388 farming households, statistical analysis show an association between adoption of both improved fallows and biomass transfer technologies with knowledge of the technology, availability of seed, and having the appropriate skills. In addition some household characteristics are found to be linked to the incidence of adoption. However, the strength of association between these variables is low, giving an indication that there might be other factors at play limiting agroforestry adoption. It is anticipated that these findings will point to other areas beyond the household and community level that need further exploration in order to understand factors limiting agroforestry adoption.Agroforestry adoption, smallholder farmers, limitations to adoption, chi-square tests of independence analysis, Zambia, Agricultural and Food Policy, Community/Rural/Urban Development, Crop Production/Industries, Environmental Economics and Policy, Land Economics/Use,
Cellular and Molecular Studies on the Mechanistic Basis of Clinical Radioresistance in Human Glioma
Human malignant glioma exhibits considerable clinical radioresistance. It has been postulated that the phenomenon of intrinsic cellular radioresistance might underlie treatment failure in these tumours. The phenomena of cellular radioresistance has been investigated in this thesis, using as models both continuous human glioma-derived cell lines, and primary cultures. The cellular radiosensitivity of five continuous glioma lines has been evaluated by clonogenic assay; this has been compared with results obtained in eight other human tumour cell lines, derived from a range of human tumour types of varying clinical radiocurability, including embryonic tumours and carcinomas. Parameters of cellular radiosensitivity were derived by fitting multitarget, and linear-quadratic models of radiation action to survival data; the model-free parameter of cellular radiosensitivity, the surviving fraction of clonogenic cells at the clinically relevant dose of 2Gy (SF2), was also measured. Considerable heterogeneity of intrinsic cellular radiosensitivity was observed in the thirteen human tumour lines studied. All five continuous glioma lines displayed values of cellular radiosensitivity within the ranges previously observed in radioresistant human cell lines. By comparison, cell lines derived from three embryonic tumours exhibited marked cellular radiosensitivity. Considerable overlap in cellular radiosensitivity was noted between five carcinoma-derived lines, and the human glioma lines.Cellular radiosensitivity of 9 primary human glioma cultures was also assessed by soft agar cloning. The intrinsic cellular radiosensitivity of both primary cultures, and continuous cell lines derived from human malignant glioma were observed to fall within the range of values previously reported for radioresistant human tumours; it is therefore suggested that intrinsic cellular radioresistance might contribute to the profound clinical radioresistance observed in human glioma. Cellular recovery from ionising radiation damage has been proposed as a determinant of intrinsic radiosensitivity. The ability of human tumour cell lines of differing intrinsic radiosensitivity to recover from sublethal radiation damage (SLD) was investigated by clonogenic cell survival following split dose irradiation. Five glioma lines exhibited an ability to recover from sublethal radiation damage, which increased with radiation dose, as predicted by the linear-quadratic model of radiation action. SLD recovery was assessed in three radiosensitive human cell lines, derived from a teratoma, SUSA, a neuroblastoma, IMR32, and an ovarian carcinoma A2780. All three lines exhibited cellular recovery, but the extent of recovery at iso-effective radiation dose levels producing 90% cell kill were lower than observed in the glioma lines.Values for recovery half-times obtained in the glioma cell lines did not differ significantly from those obtained in the three radiosensitive cell lines. Proficient recovery from sublethal damage may therefore contribute to the cellular radioresistance observed in human glioma cell lines. The molecular basis of the differences in radiosensitivity observed in human tumours remains unclear A body of evidence supports the notion that DNA double strand breaks (dsb) are a class of radiation-induced lesions which can lead to both chromosomal aberrations, and cell death. An in vitro assay has been established to assess the ability of nuclear protein extracts derived from human cells to rejoin dsb. The model dsb substrate was pIC2OH, a 2.7Kb recombinant plasmid DNA molecule bearing two bacterial genes encoding ampicillin resistance and ?-galactosidase activity; dsb of defined end-structure were produced by restriction endonuclease digestion to yield both cohesive and noncohesive termini for rejoining reactions. Rejoining activity was assessed both qualitatively, and quantitatively. Conformation of the plasmid substrate molecule was evaluated following rejoining reactions by electron microscopy, and Southern blotting. Accurate dsb rejoining enabled the plasmid molecule to confer both ampicillin resistance and beta-galactosidase activity on JM83 E.coli transformants. A protein concentration-dependent increase in rejoining of cohesive dsb (EcoR I) was detected in nuclear extracts from 4 human tumour lines studied; no significant rejoining activity for a noncohesive terminus (Nru I) was observed in any extracts. No significant difference has been detected in maximal rejoining or rejoin fidelity of cohesive dsb mediated by extracts derived from 2 radiosensitive and 2 radioresistant human tumour cell lines. Such an in vitro system provides a powerful tool for the further analysis of the molecular mechanisms involved in the recognition, and repair of ionising radiation-induced DNA lesions
Are Communities In The Triangle Ready To Do Their Fair Share? Developing a Regional Affordable Housing Strategy
Like many areas in the United States, North Carolina's Research Triangle region faces a growing and seemingly intractable scarcity of affordable housing. A suitable home, whether owned or rented, is out of reach for an increasing number of families. Even those families that are able to find housing are devoting a larger share of their financial resources toward their rent or mortgage. The problem is particularly acute near employment centers, such as Raleigh, Durham, and Chapel Hill. Many employees who work in these locations are unable to afford housing in the vicinity of their jobs and are forced to move to the fringes of the metropolitan area. This not only impacts their quality of life but also affects other Triangle residents in the form of increased traffic congestion, air pollution, and urban sprawl. The purpose of this paper is to explore whether implementing a fair share housing program might be an effective strategy for responding to the shortage of affordable housing in the Triangle. It argues that housing policies must be formulated at the regional level in order to overcome the parochialism of local governments in developing land use policies and ensure that the interests of the entire region are addressed. In contrast to other policies for increasing affordable housing, fair share programs emphasize the regional nature of the problem and specifically work to increase the distribution of affordable housing throughout a region. Thus, they have the potential to provide a solution to the spatial mismatch between jobs and housing that is a fundamental problem in the Triangle. In order to determine whether a fair share approach is right for the Triangle, the analysis begins with an evaluation of the experiences that other communities have had with fair share programs and summarizes some of the lessons learned about successful program design and implementation. The next section looks at whether the essential elements needed to support an effective fair share program currently exist in the Triangle. It concludes with an assessment of the region's readiness for a fair share program and suggestions for the next steps to take to move in the direction of increased regional cooperation in developing affordable housing policies in the Triangle.Master of City and Regional Plannin
Development and Validation of a Novel and Cost-Effective Animal Tissue Model for Training Transurethral Resection of the Prostate
The Dodd-Frank Wall Street Reform and Consumer Protection Act: unresolved issues of regulatory culture and mindset
The Dodd-Frank Act constitutes the most significant reform of financial regulation in the United States since the 1930s. Some of its provisions are bold, particularly in the areas of consumer protection and derivative trading. However, the political challenges for law reformers and regulators in the wake of the global financial crisis are far from over. The Act is inchoate. The full scope and nature of the new financial regulatory system will take several years to evolve as the mandated studies and rule making are completed and implemented. We argue that the extent to which the reforms achieve their stated objectives will depend most critically on three factors: (i) the competency, integrity and forcefulness of the federal regulators, (ii) their ability and willingness to supervise the finance industry on an integrated basis, and (iii) a fundamental change in the regulatory culture and mindset
Device-measured Desk-based Occupational Sitting Patterns and Stress (hair cortisol and perceived stress)
Background: Stress and poor mental health are significant issues in the workplace and are a major cause of absenteeism and reduce productivity. Understanding what might contribute towards employee stress is important for managing mental health in this setting. Physical activity has been shown to be beneficial to stress but less research has addressed the potential negative impact of sedentary behaviour such as sitting. Therefore, the aim of this study was to assess the relationship between device-measured occupational desk-based sitting patterns and stress (hair cortisol levels (HCL), as a marker of chronic stress and self-reported perceived stress (PS)). Methods: Employees were recruited from four workplaces located in Central Scotland with large numbers of desk-based occupations. Seventy-seven participants provided desk-based sitting pattern data (desk-based sitting time/day and desk-based sit-to-stand transitions/day), a hair sample and self-reported perceived stress. HCL were measured using enzyme-linked immunosorbent assay and PS using the Cohen Self-Perceived Stress Scale. Linear regression models were used to test associations between desk-based sitting time/day, desk-based sit-to-stand transitions/day, HCL and PS. Results: There were no associations between any of the desk-based sitting measures and either HCL or PS. Conclusion. Desk-based sitting patterns in the workplace may not be related to stress when using HCL as a biomarker or PS. The relationship between sitting patterns and stress therefore requires further investigation
- …