Community Management of Natural Resources in Africa: Impacts, Experiences and Future Directions

More than twenty years have passed since community-based natural resource management (CBNRM) rose to prominence in different parts of Africa as a strategy for rural development, local empowerment, and conservation. Led by new ideas about the merits of decentralized, collective resource governance regimes, and creative field experiments such as Zimbabwe's CAMPFIRE, these community-based approaches evolved in a wide range of ecological, political, and social contexts across Africa. This review provides an unprecedented pan-African synthesis of CBNRM, drawing on multiple authors and a wide range of documented experiences from Southern, Eastern, Western and Central Africa. The review discusses the degree to which CBNRM has met poverty alleviation, economic development and nature conservation objectives. In its concluding chapter, the report suggests a way forward for strengthening CBNRM and addressing key challenges in the years ahead

Field trip guide to Oligocene Limestones and Caves in the Waitomo District

The field guide runs from Hamilton to Waitomo to Te Anga and return in limestone-dominated country developed in transgressive sedimentary deposits of the Oligocene Te Kuiti Group – a world class example of a temperate shelf carbonate depositional system. Attention focuses on the nature, distribution and paleoenvironmental controls of the main limestone facies and some of the mixed terrigenous-carbonate facies in the Group. Along the way features of the Waitomo karst landscape are noted and the trip concludes by going underground in the Ruakuri Cave to discuss cave origins and the evidence for paleoenvironmental changes locked up in speleothems

African Trade Policy in the 1990s: Political Economy or Technocratic Reforms?

The majority of African countries implemented import liberalisation in the 1990s. This paper explores factors that may explain the pattern of protection and of tariff reform. We consider political economy explanations, motivated specifically by the Grossman and Helpman (1994) model of protection in response to industry lobbies, and the possibility that reforms are technocratic. Using industry-level data for a sample of six African countries, we find limited evidence that political economy factors have influenced the pattern of tariffs or tariff reductions since the early 1990s. One result does appear frequently: relative sector size (measured by the number of employees or establishments) appears to be associated with the relative level of protection. We then explore various descriptive statistics for tariff changes in seven African countries. The analysis suggests that the pattern of tariff reductions was essentially technocratic in structure - across the board reduction in average tariffs and in the dispersion of rates, with larger proportional reductions for higher tariffs – consistent with policy reforms being guided by the World Bank. While political economy factors may have influenced the initial pattern of protection, the technocratic reforms since the early 1990s have diluted political economy influences on average and relative protection.Pattern of Protection, Tariff Reform, Political Economy, Africa

Carbon Nanotube Cluster Based Micro-Fluidic System for Bacteria Capture, Concentration, and Separation

Disease-causing pathogens continue presenting enormous global health problems, especially due to their easy transmittance to people via water supply systems. The detection, filtration, and purification of bacteria-contaminated water samples are complex activities, ones subject to considerable error. Here we present a new and highly effective micro-fluidic system with carbon nanotube (CNT) clusters for effective and efficient detection, filtration, and purification of bacteria-contaminated medium. The developed system is based upon two unique properties of CNT clusters: high bacterial affinity and magnetic susceptibility. The CNTs \u27high affinity to bacteria cells makes them a key candidate for the bacteria adsorption. The magnetic susceptibility of their clusters allows an effective way of separating as well as containing them in the system. Inthis study, we designed and tested a prototype CNT-cluster based micro-fluidic system by uniquely combining the two excellent properties of CNTs. The CNT-based micro-system consisted of a micro-channel, which positions CNT clusters evenly on the bottom surface using a strong Neodymium block (1 X 1 X 1 ) rare-earth magnet (surface magnetic field strength= 0.684 Testa). When bacteria suspensions were introduced, the CNT clusters in the micro-fluidic system were shown to effectively serve as bacterial adsorbing centers, which led to spontaneous adsorption and concentration of bacteria to the clusters. This was shown to happen for both types of microorganisms, i.e., Gram-positive and Gram-negative bacteria. The results demonstrate the excellent potential of the CNT based micro-fluidic system for bacteria capture, concentration, and separation

Deep-water turbidites as Holocene earthquake proxies: the Cascadia subduction zone and Northern San Andreas Fault systems

New stratigraphic evidence from the Cascadia margin demonstrates that 13 earthquakes ruptured the margin from Vancouver Island to at least the California border following the catastrophic eruption of Mount Mazama. These 13 events have occurred with an average repeat time of ?? 600 years since the first post-Mazama event ?? 7500 years ago. The youngest event ?? 300 years ago probably coincides with widespread evidence of coastal subsidence and tsunami inundation in buried marshes along the Cascadia coast. We can extend the Holocene record to at least 9850 years, during which 18 events correlate along the same region. The pattern of repeat times is consistent with the pattern observed at most (but not all) localities onshore, strengthening the contention that both were produced by plate-wide earthquakes. We also observe that the sequence of Holocene events in Cascadia may contain a repeating pattern, a tantalizing look at what may be the long-term behavior of a major fault system. Over the last ?? 7500 years, the pattern appears to have repeated at least three times, with the most recent A.D. 1700 event being the third of three events following a long interval of 845 years between events T4 and T5. This long interval is one that is also recognized in many of the coastal records, and may serve as an anchor point between the offshore and onshore records. Similar stratigraphic records are found in two piston cores and one box core from Noyo Channel, adjacent to the Northern San Andreas Fault, which show a cyclic record of turbidite beds, with thirty- one turbidite beds above a Holocene/.Pleistocene faunal «datum». Thus far, we have determined ages for 20 events including the uppermost 5 events from these cores. The uppermost event returns a «modern» age, which we interpret is likely the 1906 San Andreas earthquake. The penultimate event returns an intercept age of A.D. 1664 (2 ?? range 1505- 1822). The third event and fourth event are lumped together, as there is no hemipelagic sediment between them. The age of this event is A.D. 1524 (1445-1664), though we are not certain whether this event represents one event or two. The fifth event age is A.D. 1204 (1057-1319), and the sixth event age is A.D. 1049 (981-1188). These results are in relatively good agreement with the onshore work to date, which indicates an age for the penultimate event in the mid-1600 s, the most likely age for the third event of ?? 1500-1600, and a fourth event ?? 1300. We presently do not have the spatial sampling needed to test for synchroneity of events along the Northern San Andreas, and thus cannot determine with confidence that the observed turbidite record is earthquake generated. However, the good agreement in number of events between the onshore and offshore records suggests that, as in Cascadia, turbidite triggers other than earthquakes appear not to have added significantly to the turbidite record along the northernmost San Andreas margin during the last ?? 2000 years

Carbon Nanotube Cluster Based Micro-Fluidic System for Bacteria Capture, Concentration, and Separation

Disease-causing pathogens continue presenting enormous global health problems, especially due to their easy transmittance to people via water supply systems. The detection, filtration, and purification of bacteria-contaminated water samples are complex activities, ones subject to considerable error. Here we present a new and highly effective micro-fluidic system with carbon nanotube (CNT) clusters for effective and efficient detection, filtration, and purification of bacteria-contaminated medium. The developed system is based upon two unique properties of CNT clusters: high bacterial affinity and magnetic susceptibility. The CNTs \u27high affinity to bacteria cells makes them a key candidate for the bacteria adsorption. The magnetic susceptibility of their clusters allows an effective way of separating as well as containing them in the system. Inthis study, we designed and tested a prototype CNT-cluster based micro-fluidic system by uniquely combining the two excellent properties of CNTs. The CNT-based micro-system consisted of a micro-channel, which positions CNT clusters evenly on the bottom surface using a strong Neodymium block (1 X 1 X 1 ) rare-earth magnet (surface magnetic field strength= 0.684 Testa). When bacteria suspensions were introduced, the CNT clusters in the micro-fluidic system were shown to effectively serve as bacterial adsorbing centers, which led to spontaneous adsorption and concentration of bacteria to the clusters. This was shown to happen for both types of microorganisms, i.e., Gram-positive and Gram-negative bacteria. The results demonstrate the excellent potential of the CNT based micro-fluidic system for bacteria capture, concentration, and separation

Extracting 3D parametric curves from 2D images of Helical objects

Helical objects occur in medicine, biology, cosmetics, nanotechnology, and engineering. Extracting a 3D parametric curve from a 2D image of a helical object has many practical applications, in particular being able to extract metrics such as tortuosity, frequency, and pitch. We present a method that is able to straighten the image object and derive a robust 3D helical curve from peaks in the object boundary. The algorithm has a small number of stable parameters that require little tuning, and the curve is validated against both synthetic and real-world data. The results show that the extracted 3D curve comes within close Hausdorff distance to the ground truth, and has near identical tortuosity for helical objects with a circular profile. Parameter insensitivity and robustness against high levels of image noise are demonstrated thoroughly and quantitatively

Las Vegas X 3 @ 2030-Part 1 & 2

Part 1, 12 PowerPoint slide