Metamorphic Petrology, Engineering Geology: GLG 322
- Authors: Jia, H , Gunter, C J , Huizenga, J M
- Date: 2009-10
- Subjects: Geology
- Language: English
- Type: Examination paper
- Identifier: vital:17885 , http://hdl.handle.net/10353/d1011014
- Description: Metamorphic Petrology, Engineering Geology: GLG 322, degree examination October/November 2009.
- Full Text: false
- Date Issued: 2009-10
English: ECL 120
- Authors: Wood, F , Blatchford, M , Formson, C , Mndebele, A T , Morkel, N
- Date: 2009-06
- Language: English
- Type: Examination paper
- Identifier: vital:18300 , http://hdl.handle.net/10353/d1011308
- Description: English: ECL 120, main examinations June 2009.
- Full Text: false
- Date Issued: 2009-06
A tetrapod fauna from within the Devonian Antarctic Circle
- Authors: Gess, Robert W , Ahlberg, Per Erik Ahlberg
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/72690 , vital:30100 , https://doi.org/10.1126/science.aaq1645 , https://www.sciencemag.org/content/360/6393/1120/suppl/DC1
- Description: Until now, all known fossils of tetrapods (limbed vertebrates with digits) and near-tetrapods (such as Elpistostege, Tiktaalik, and Panderichthys) from the Devonian period have come from localities in tropical to subtropical paleolatitudes. Most are from Laurussia, a continent incorporating Europe, Greenland, and North America, with only one body fossil and one footprint locality from Australia representing the southern supercontinent Gondwana. Here we describe two previously unknown tetrapods from the Late Devonian (late Famennian) Gondwana locality of Waterloo Farm in South Africa, then located within the Antarctic Circle, which demonstrate that Devonian tetrapods were not restricted to warm environments and suggest that they may have been global in distribution.
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- Date Issued: 2009
Apis florea in Jordan: source of the founder population
- Authors: Haddad, N , Fuchs, S , Hepburn, H Randall , Radloff, Sarah E
- Date: 2009
- Language: English
- Type: text , Article
- Identifier: vital:6844 , http://hdl.handle.net/10962/d1011047
- Description: A recent isolated population of Apis florea has been reported from Aqaba in Jordan at the Red Sea, consisting of numerous colonies within a still limited range which apparently is expanding. This region is about 1500 km apart from its next occurrences in Sudan where it had been introduced and first detected in 1985 and about 2000 km apart from its next natural occurrences in Iran and Oman. These bees apparently have been imported by human transport, most likely by ship. This new location thus represents a major jump in the progression of the species still to fill a wide area of possible locations offering adequate living conditions. Here we attempt to track the possible origin of this new population by morphometric methods. This analysis indicated closest relation to A. florea from Oman, thus being the most likely source of this population.
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- Date Issued: 2009
Augmenting an e-Commerce service for Marginalized Communities: A Rewards Based Marketing Approach
- Authors: Jere, Norbert R , Thinyane, Mamello , Terzoli, Alfredo
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428463 , vital:72513 , https://www.researchgate.net/profile/Alfredo-Terzoli/publication/228968666_Augmenting_an_e-Com-merce_service_for_Marginalized_Communities_A_Rewards_Based_Marketing_Approach/links/09e4151344c1f615f7000000/Augmenting-an-e-Commerce-service-for-Marginalized-Communities-A-Rewards-Based-Marketing-Approach.pdf
- Description: Information and Communication technologies (ICTs) have been widely deployed in developmental programmes and this has lead to the crea-tion of a new field–ICT for development (ICT4D). Many e-Commerce platforms now exist in many rural areas in developing countries. ICT4D allows Small, Medium and Micro Enterprises (SMMEs) in rural areas to increase sales and gain the market share on the global market. Howev-er, many of these ICT4D projects in marginalized areas fail as a result of lacking the required resources to support ICTs. SMMEs in rural areas face problems in marketing their products on the global market. There-fore, ensuring sustainability of such systems in marginalized areas is important. This paper explains an e-Marketing strategy through a re-ward based negotiation application, aimed at improving the existing e-Commerce platform. The e-Commerce platform has been deployed for the Dwesa community. Dwesa is a rural area in the Eastern Cape prov-ince of South Africa.
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- Date Issued: 2009
Drought, change and resilience in South Africa's arid and semi-arid rangelands
- Authors: Vetter, Susan M
- Date: 2009
- Language: English
- Type: Article
- Identifier: vital:6557 , http://hdl.handle.net/10962/d1006017
- Description: Droughts can have serious ecological and economic consequences and will pose an increasing challenge to rangeiand users as the global climate is changing. Finding ways to reduce ecological and economic impacts of drought should thus be a major research thrust. Resilience, defined as the amount of perturbation a social or ecological system can absorb without shifting to a qualitatively different state, has emerged as a prominent concept in ecosystem ecology and more recently as a conceptual framework for understanding and managing complex social-ecological systems. This paper discusses the application and relevance of resilience to understanding and managing ecosystem change, and enhancing the capacity of land users to adapt to droughts. Drought can trigger vegetation change and factors such as grazing management can influence the likelihood of such transitions. Drought can cause differential mortality of perennial plants and this could provide an opportunity for rangeland restoration by opening up establishment sites for desirable species. The capacity of land users to cope with drought is influenced by the resilience of their agro-ecosystems, the diversity of livelihood options, access to resources and institutional support. By these criteria, current agricultural development approaches in South Africa, particularly in communal rangelands and areas of land reform, are unlikely to enhance land users' resilience to drought and other perturbations.
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- Date Issued: 2009
Rhodes University 2009 Graduation Ceremonies Address
- Authors: Badat, Saleem
- Date: 2009
- Language: English
- Type: text
- Identifier: vital:7585 , http://hdl.handle.net/10962/d1006575
- Description: From introduction: To be awarded a degree or diploma from Rhodes University entails dedicated endeavour. When you joined us you were told that at Rhodes learning and education is a partnership, a relationship of mutual commitment to the pursuit of knowledge and understanding, to the development of expertise and skills, and to the embrace of appropriate values and attitudes. Your graduation is testimony that you have fulfilled your side of the partnership. You have displayed the necessary commitment and willingness to learn, to acquire knowledge and to develop expertise. Your achievement, the fruits of many months and years of toil, is,ultimately, your own great accomplishment.
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- Date Issued: 2009
Simulating crowd phenomena in african markets
- Authors: Tasse, Flora P , Glass, Kevin R , Bangay, Shaun D
- Date: 2009
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433285 , vital:72959 , https://doi.org/10.1145/1503454.1503463
- Description: Crowd simulation is an important feature in the computer graphics field. Typical implementations simulate battle scenes, emergency situations, safety issues or add content to virtual environments. The problem stated in this paper falls in the last category. We present a crowd simulation behavioural model which allows us to simulate identified phenomena in popular local African markets such as narrow street flows and crowd formation around street performances. We propose a three-tier architecture model enable to produce intentions, perform path planning and control movement. We demonstrate that this approach produces the desired behaviour associated with crowds in an African market, which includes navigation, flow formation and circle creation.
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- Date Issued: 2009
The willingness to pay for dusky kob (Argyrosomus japonicus) restocking: using recreational linefishing licence fees to fund stock enhancement in South Africa
- Authors: Palmer, Ryan M , Snowball, Jeanette D
- Date: 2009
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/71322 , vital:29833 , https://doi.org/10.1093/icesjms/fsp075
- Description: The economic feasibility of stock enhancement of Argyrosomus japonicus in South Africa was investigated using a willingness-to-pay (WTP) survey. The pilot study provides a unique example of the use of the contingent valuation method as a valuation tool for a proposed stock enhancement programme. An increase in the cost of a recreational fishing permit is used as a potential vehicle of payment. The median value of the maximum that fishers were willing to pay for a recreational fishing permit was R155 (South African Rand) for frequent fishers and R100 for non-frequent fishers. Analysis showed that a fee of more than R100 excluded up to 50% of anglers from the fishery, but that a fee of R100 excluded only 28% of recreational anglers and would generate an additional R12 million annually from the sale of recreational fishing permits. The estimated costs of set-up and running of a stock enhancement programme are substantially lower than this, suggesting that stock enhancement may be an economically feasible management option that deserves more investigation. The WTP method itself produces robust results and is likely to be an effective tool in the management of the marine environment.
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- Date Issued: 2009
An Investigation into the Performance of General Sorting on Graphics Processing Units
- Authors: Pilkington, Nick , Irwin, Barry V W
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/429881 , vital:72648 , https://doi.org/10.1007/978-1-4020-8741-7_65
- Description: Sorting is a fundamental operation in computing and there is a constant need to push the boundaries of performance with different sorting algo-rithms. With the advent of the programmable graphics pipeline, the par-allel nature of graphics processing units has been exposed allowing programmers to take advantage of it. By transforming the way that data is represented and operated on parallel sorting algorithms can be im-plemented on graphics processing units where previously only graphics processing could be performed. This paradigm of programming exhibits potentially large speedups for algorithms.
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- Date Issued: 2008
Flock inspired area coverage using wireless boid-like sensor agents
- Authors: Chibaya, Colin , Bangay, Shaun D
- Date: 2008
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/433440 , vital:72970 , 10.1109/UKSIM.2008.102
- Description: Simulated flocking is achievable using three boid rules [13]. We propose an area coverage model inspired by Reynolds’ flocking algorithm, investigating strategies for achieving quality coverage using flocking rules. Our agents are identical and autonomous, using only local sensory information for indirect communication. Upon deployment, agents are in the default separation mode. The cohesion rule would then guarantee that agents remain within the swarm, covering spaces with explored neighbour spaces. Four experiments are conducted to evaluate our model in terms of coverage quality achieved. We firstly investigate agents’ separation speed before the speed with which isolated agents re-organizes is investigated. The third experiment compares coverage quality achieved using our model with coverage quality achieved using random guessing. Finally, we investigate fault tolerance in the event of agents’ failures. Our model exhibits good separation and cohesion speed, achieving high quality coverage. Additionally, the model is fault tolerant and adaptive to agents’ failures.
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- Date Issued: 2008
AfrOBIS: a marine biogeographic information system for sub-Saharan Africa
- Authors: Grundlingh, M L , St Ange, U B , Bolton, John J
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:7137 , http://hdl.handle.net/10962/d1011813
- Description: AfrOBIS is one of 11 global nodes of the Ocean Biogeographic Information System (OBIS), a freely accessible network of databases collating marine data in support of the Census of Marine Life.Versatile graphic products, provided by OBIS, can be used to display the data. To date, AfrOBIS has loaded about 3.2 million records of more than 23 000 species located mainly in the seas around southern Africa. This forms part of the 13.2 million records of more than 80 000 species currently stored in OBIS. Scouting for South African data has been successful, whereas locating records in other African countries has been much less so.
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- Date Issued: 2007
Bee-hawking by the wasp, Vespa velutina, on the honeybees Apis cerana and A. mellifera
- Authors: Tan, K , Radloff, Sarah E , Li, J J , Hepburn, H Randall , Yang, Ming-Xian , Zhang, L J , Neumann, Peter
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6941 , http://hdl.handle.net/10962/d1011965
- Description: The vespine wasps, Vespa velutina, specialise in hawking honeybee foragers returning to their nests. We studied their behaviour in China using native Apis cerana and introduced A. mellifera colonies. When the wasps are hawking, A. cerana recruits threefold more guard bees to stave off predation than A. mellifera. The former also utilises wing shimmering as a visual pattern disruption mechanism, which is not shown by A. mellifera. A. cerana foragers halve the time of normal flight needed to dart into the nest entrance, while A. mellifera actually slows down in sashaying flight manoeuvres. V. velutina preferentially hawks A. mellifera foragers when both A. mellifera and A. cerana occur in the same apiary. The pace of wasp-hawking was highest in mid-summer but the frequency of hawking wasps was three times higher at A. mellifera colonies than at the A. cerana colonies. The wasps were taking A. mellifera foragers at a frequency eightfold greater than A. cerana foragers. The final hawking success rates of the wasps were about three times higher for A. mellifera foragers than for A. cerana. The relative success of native A. cerana over European A. mellifera in thwarting predation by the wasp V. velutina is interpreted as the result of co-evolution between the Asian wasp and honeybee, respectively.
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- Date Issued: 2007
Bridging the gap for Next Generation Services: Presence Services on Legacy Devices
- Authors: Moyo, Thamsanqa , Thinyane, Mamello , Wright, Madeleine , Irwin, Barry V W , Clayton, Peter G , Terzoli, Alfredo
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428177 , vital:72491 , https://d1wqtxts1xzle7.cloudfront.net/49665432/Paper_2063_20-_20Moyo-libre.pdf?1476717366=andresponse-content-disposi-tion=inline%3B+filename%3DBridging_the_gap_for_Next_Generation_Ser.pdfandEx-pires=1714737455andSignature=RRbr9pzIYSYX8v7FG6FzV4tu3dFXm9qmmqq5WirOhuYdt--mjOfcDHQNLPYZHCmtgYZWdVk6bVFxfGOVJxgXrvkTe2QN2AZV3XfFTZ3mi1s3A5gw2jIXOVHrYUnaf~POgdijdY85mqWhco3vL6Qk3sOZgYjIlTF5ZGAKg1S54W978Nom01cT2~oqRA0Et6mTNmydWfF5MhFxQIq~LNmYqEqmEESKkkWQFwg6xJJUu0uGffbaZXXBA6oDI2cpfkz1FleKyKaRDRJvdfnuTHPoJJ4TzfO6DDVCWKvJ45jaxIzaGmK-03Ai29I-DPyy-c557kZh~kF3rmDg3zrXVNaL8A__andKey-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: Next generation services are provided by applications that leverage packet-based domains. A challenge faced by such services is the support for multiple devices, including legacy devices. Our paper examines a strategy for the pro-vision of next generation services on legacy cellular network devices. We ad-vocate that the provision of next generation services via applications on the SIM card allows for the deployment of such services on legacy devices. We demonstrate this assertion through a proof of concept application, SIMPre, that resides on a SIM card. SIMPre implements a presence service by leveraging Java Card, the SIM Application Toolkit and the OMA IMPS standard. We show that it is possible to provide a next generation service on the SIM card such that it ubiquitously integrates with the functionality of a legacy device. We con-clude through this demonstration that the SIM card is a viable option for provid-ing backward compatibility to legacy devices in the implementation of next generation services.
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- Date Issued: 2007
Bridging the gap for Next Generation Services: Presence Services on Legacy Devices
- Authors: Moyo, Thamsanqa , Thinyane, Mamello , Wright, Madeleine , Irwin, Barry V W , Clayton, Peter G , Terzoli, Alfredo
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428176 , vital:72492 , https://d1wqtxts1xzle7.cloudfront.net/49665432/Paper_2063_20-_20Moyo-libre.pdf?1476717366=andresponse-content-disposi-tion=inline%3B+filename%3DBridging_the_gap_for_Next_Generation_Ser.pdfandEx-pires=1714737455andSignature=RRbr9pzIYSYX8v7FG6FzV4tu3dFXm9qmmqq5WirOhuYdt--mjOfcDHQNLPYZHCmtgYZWdVk6bVFxfGOVJxgXrvkTe2QN2AZV3XfFTZ3mi1s3A5gw2jIXOVHrYUnaf~POgdijdY85mqWhco3vL6Qk3sOZgYjIlTF5ZGAKg1S54W978Nom01cT2~oqRA0Et6mTNmydWfF5MhFxQIq~LNmYqEqmEESKkkWQFwg6xJJUu0uGffbaZXXBA6oDI2cpfkz1FleKyKaRDRJvdfnuTHPoJJ4TzfO6DDVCWKvJ45jaxIzaGmK-03Ai29I-DPyy-c557kZh~kF3rmDg3zrXVNaL8A__andKey-Pair-Id=APKAJLOHF5GGSLRBV4ZA
- Description: Next generation services are provided by applications that leverage packet-based domains. A challenge faced by such services is the support for multiple devices, including legacy devices. Our paper examines a strategy for the pro-vision of next generation services on legacy cellular network devices. We ad-vocate that the provision of next generation services via applications on the SIM card allows for the deployment of such services on legacy devices. We demonstrate this assertion through a proof of concept application, SIMPre, that resides on a SIM card. SIMPre implements a presence service by leveraging Java Card, the SIM Application Toolkit and the OMA IMPS standard. We show that it is possible to provide a next generation service on the SIM card such that it ubiquitously integrates with the functionality of a legacy device. We con-clude through this demonstration that the SIM card is a viable option for provid-ing backward compatibility to legacy devices in the implementation of next generation services.
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- Date Issued: 2007
Climate change, genetics or human choice: why were the shells of mankind’s earliest ornament larger in the Pleistocene than in the Holocene?
- Authors: Teske, Peter R , Papadopoulos, Isabelle , McQuaid, Christopher D , Newman, Brent K , Barker, Nigel P
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6952 , http://hdl.handle.net/10962/d1011984
- Description: The southern African tick shell, Nassarius kraussianus (Dunker, 1846), has been identified as being the earliest known ornamental object used by human beings. Shell beads dated from ~75,000 years ago (Pleistocene era) were found in a cave located on South Africa's south coast. Beads made from N. kraussianus shells have also been found in deposits in this region dating from the beginning of the Holocene era (<10,000 years ago). These younger shells were significantly smaller, a phenomenon that has been attributed to a change in human preference. We investigated two alternative hypotheses explaining the difference in shell size: a) N. kraussianus comprises at least two genetic lineages that differ in size; b) the difference in shell size is due to phenotypic plasticity and is a function of environmental conditions. To test these hypotheses, we first reconstructed the species' phylogeographic history, and second, we measured the shell sizes of extant individuals throughout South Africa. Although two genetic lineages were identified, the sharing of haplotypes between these suggests that there is no genetic basis for the size differences. Extant individuals from the cool temperate west coast had significantly larger shells than populations in the remainder of the country, suggesting that N. kraussianus grows to a larger size in colder water. The decrease in fossil shell size from Pleistocene to Holocene was likely due to increased temperatures as a result of climate change at the beginning of the present interglacial period. We hypothesise that the sizes of N. kraussianus fossil shells can therefore serve as indicators of the climatic conditions that were prevalent in a particular region at the time when they were deposited. Moreover, N. kraussianus could serve as a biomonitor to study the impacts of future climate change on coastal biota in southern Africa.
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- Date Issued: 2007
Evaluating compression as an enabler for centralised monitoring in a Next Generation Network
- Authors: Otten, Fred , Irwin, Barry V W , Slay, Hannah
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/428226 , vital:72495 , https://citeseerx.ist.psu.edu/document?repid=rep1andtype=pdfanddoi=f9ed69db7da44c168082934cd4ea5a413b2bf7f5
- Description: With the emergence of Next Generation Networks and a large number of next generation services, the volume and diversity of information is on the rise. These networks are often large, distributed and consist of het-erogeneous devices. In order to provide effective centralised monitoring and control we need to be able to assemble the relevant data at a cen-tral point. This becomes difficult because of the large quantity of data. We also would like to achieve this using the least amount of bandwidth, and minimise the latency. This paper investigates using compression to enable centralised monitoring and control. It presents the results of ex-periments showing that compression is an effective method of data re-duction, resulting in up to 93.3 percent reduction in bandwidth usage for point-to-point transmission. This paper also describes an architecture that incorporates compression and provides centralised monitoring and control.
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- Date Issued: 2007
The effects of buffer molarity, agitation rate and mesh size on verapamil release from modified release mini-tablets using USP Apparatus 3
- Authors: Khamanga, Sandile M , Walker, Roderick B
- Date: 2007
- Language: English
- Type: text , Article
- Identifier: vital:6386 , http://hdl.handle.net/10962/d1006307
- Description: The effects of agitation rate, buffer molarity,and mesh size on the dissolution rate of verapamil hydrochloride from sustained release matrix tablets were studied using USP Apparatus 3. Eudragit® and Carbopol® were used as rate-retarding polymers in tablets prepared by wet granulation.The study was conducted to determine whether the drugs exhibit similar release characteristics when tested under the same dissolution conditions. It was found that the dissolution rate of verapamil hydrochloride was affected by the variables assessed in these studies.
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- Date Issued: 2007
Towards continental transformation: understanding sustainable peace agreements in Africa
- Authors: Bischoff, Paul, 1954-
- Date: 2007
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/161409 , vital:40624 , https://0-hdl.handle.net.wam.seals.ac.za/10520/EJC15983
- Description: There are social and political questions to be asked about the new continent-wide institutions in and around what is still a young African Union (AU). These include questions such as whether the AU and its institutions can be built in ways that will allow this body to transform Africa's international relations, and how this is to be done. What are the norms and values that will inform this change and the African renewal promoted by the AU? Is the multilateral architecture of the AU able to encourage democracy and people-centredness, for instance? Will it, in the end, be able to deliver on the hoped-for "pan-African transnational democratic revolution"?.
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- Date Issued: 2007
Wi-Fi as a last mile access technology and The Tragedy of the Commons
- Authors: Brandt, Ingrid , Terzoli, Alfredo , Hodgkinson-Williams, Cheryl
- Date: 2007
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/431106 , vital:72744 , https://doi.org/10.1007/978-1-4020-6266-7_33
- Description: With an alarmingly low teledensity in South Africa, just 12%, and not much hope of further wired infrastructure at the local loop level, as the costs incurred are high compared to potential revenue, wireless con-nectivity could be a great asset and service in South Africa. However, the use of unlicensed spectrum in building wireless networks can be comparable to “The Tragedy of the Commons”, the result of selfish be-haviour towards common and limited resources. This paper evaluates the use of 802.11 wireless technologies in building a broadband wire-less network and the effects of high amounts of interference on such a network. The paper concludes that for urban areas 802.11 technologies using unlicensed spectrum is not advisable, unless used in point-to-point links, while its use in rapid rural development (where there is less interference) is very promising.
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- Date Issued: 2007