| 1. |
- Zoric, Neven, et al.
(författare)
-
Quantitative PCR: A promising technique investigating the early bone-implant interface
- 2007
-
Ingår i: Abstract, European Association for Osseointegration (EAO), 16th Annual Scientific Meeting, Barcelona, Spain. ; 25-27 October
-
Konferensbidrag (refereegranskat)abstract
- Objectives: Studies on the early tissue response to materials are difficult due to the inaccessibility of the interface zone and lack of sensitive techniques. The purpose of the present study was to apply quantitative PCR (qPCR) in combination with LM and SEM for the evaluation of early gene expression response as well as cellular reactions close to titanium implants. Experimental methods: Anodically oxidized titanium (TiUniteTM; Nobel Biocare AB) and machined titanium implants (2mm×2mm) were inserted in the rat tibia. After 1,3, and 6 days, implants were unscrewed and surrounding bone was retrieved. Both the implants and bone were analyzed with qPCR, routine histology and SEM. The amount of mRNA was normalized to 18S protein subunit. Results: After the initial inflammatory response, the tissue located inside the threads became rapidly organized. SEM analysis showed mesenchymal-like cells extending their processes into the pores of the anodically oxidized surface. qPCR demonstrated significantly higher 18S around anodically oxidized screws and in the surrounding tissues. Alkaline phosphatase (osteoblast marker), TRAP and Cathepsin K (osteoclast markers) mRNA, but not the inflammatory markers (TNF-alpha and IL-1beta) were expressed at different levels around the two surfaces. Conclusions: The results demonstrate that the experimental model and qPCR provide interesting possibilities to analyze the mechanisms of osseointegration. Furthermore, remodelling and in particular the molecular processes occur at implant surfaces in vivo already 3 days after implantation. Support: Swedish Research Council and the Institute for Biomaterials and Cell Therapy, Göteborg, Sweden
|
|
| 2. |
|
|
| 3. |
- al-Askary, Omar, et al.
(författare)
-
Effect of error in CSI on the capacity of Rayleigh fading channels with QAM signalling and the design of robust signal constellations
- 2007
-
Ingår i: IET Communications. - : Institution of Engineering and Technology (IET). - 1751-8628 .- 1751-8636. ; 1:6, s. 1118-1125
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of channel estimation errors on the channel capacity of a discrete time, discrete input, infinite output Rayleigh fading channel are investigated. The case of conventional modulation methods such as phase shift keying (PSK) and quatrature amplitude modulation (QAM) is investigated at first where it was observed that the capacity degrades rapidly with increasing channel estimation errors. The effect of error in the channel estimation is similar to the effect of higher noise in the channel that depends on the transmitted signal. A genetic algorithm is used to optimise the signal constellation in order to maximise the capacity for a given finite number of signal points. The aim of trying to maximise the capacity is to estimate the remaining gap in performance between a traditional modulation scheme such as QAM and the best possible constellation that is optimised for the channel. The constellations obtained from the genetic algorithm are, in general, not directly implementable. A method to design practical robust signal constellations that overcome the effect of channel state information (CSI) error is presented. The robust signal constellations obtained show a performance that is very close to the optimal constellations. In this work, the probability distribution of the error in CSI is assumed to be known.
|
|
| 4. |
- Al-Shalabi, Ammar, et al.
(författare)
-
Outsourcing and organizing of NPD : A Survey of Malaysian industry
- 2007
-
Ingår i: Proceedings from EIASM 14th IPDMC. - : European Institute for Advanced Studies in Management (EIASM). ; , s. 12-
-
Konferensbidrag (populärvet., debatt m.m.)abstract
- Malaysian manufacturing firms are interested in New Product Development (NPD) methods, due to the fact that they are competitive tools for survival. The purpose of the present study is to investigate NPD practices in Malaysia, in particular the outsourcing of NPD and the organizing of NPD. We achieved our objectives by conducting a survey of 72 companies in the automotive, chemical, and electrical industries and analyzing the results. Managers involved in NPD will benefit from the findings presented in this paper. The results indicate that the NPD practices used in Malaysian firms focus more on production cost and manufacturability, whereas the need for increased knowledge receives lower priority.
|
|
| 5. |
- Ali, Magdi M. M., et al.
(författare)
-
Fc gamma RIIa (CD32) polymorphism and onchocercal skin disease : implications for the development of severe reactive onchodermatitis (ROD)
- 2007
-
Ingår i: American Journal of Tropical Medicine and Hygiene. - Lawrence, Kans. : American society of tropical medicine and hygiene. - 0002-9637 .- 1476-1645. ; 77:6, s. 1074-8
-
Tidskriftsartikel (refereegranskat)abstract
- The pathologic manifestations of Onchocerca volvulus infection depend on the interplay between the host and the parasite. A genetic single nucleotide polymorphism in the Fc gamma RIIa gene, resulting in arginine (R) or histidine (H) at position 131, affects the binding to the different IgG subclasses and may influence the clinical variations seen in onchocerciasis. This study investigated the relationship between this polymorphism and disease outcome. Fc gamma RIIa genotyping was performed on clinically characterized onchocerciasis patients (N = 100) and healthy controls (N = 74). Fc gamma RIIa genotype R/R131 frequencies were significantly higher among patients with severe dermatopathology (P < 0.001). Increased risk of developing this form was mostly associated with one tribe (Masalit) (OR = 3.2, 95% CI 1-9.9, P = 0.042). The H131 allele was found to be significantly associated with a reduced risk of having the severe form of the disease (adjusted OR = 0.26, 95% CI = 0.13-0.46, P < 0.001). Our findings suggest that the polymorphism influences the clinical outcome of onchocerciasis.
|
|
| 6. |
- Berggren, Per, et al.
(författare)
-
Sustainable Dolphin Tourism in East Africa
- 2007
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The MASMA sustainable dolphin tourism project was a collaborative research effort conducted between 2003 and 2006 with participants from Mozambique, South Africa, Sweden and Zanzibar. The objectives were to build the capacity for sustainable dolphin tourism in the East African region. Both basic and applied research was conducted to assess status and promote effective conservation and management of dolphin populations and tourism activities while accounting for local socio-economic aspects. In order to implement this, an interdisciplinary approach provided scientific information on the animals’ distribution, abundance, mortality, genetic population structure, biology, ecology, behaviour, and information on human social and socio-economic structure. The project was conducted in two geographical areas where dolphin tourism activities are ongoing in East Africa; south coast of Zanzibar and Ponta do Ouro, Mozambique. Additional studies were also conducted at Inhaca Island, Mozambique. Questionnaires were used to collect data from stake-holders and local communities, boat based surveys to collect data and samples on local dolphin populations and observer programmes to investigate fisheries mortalities. The Indo-Pacific bottlenose dolphin (Tursiops aduncus) was the focal species in the studies because it is the target species for the tourism, however Indo-Pacific humpback dolphins (Sousa chinensis) were also considered in the research conducted.Photographic identification data of individual dolphins showed limited distribution of small resident populations of Indo-Pacific bottlenose and humpback dolphins off the south coast of Zanzibar, and humpback dolphins at Inhaca. Residency was determined based on high percentages of within and between year resightings. The latest population size estimates were: 136 Indo-Pacific bottlenose and 63 humpback dolphins off the south coast of Zanzibar, and 165 Indo-Pacific humpback dolphins off Inhaca. No estimate of population size is available for the Indo-Pacific bottlenose dolphins off Ponta do Ouro. Both Indo-Pacific bottlenose and humpback dolphins off the South coast of Zanzibar had very restricted distributions and only used limited parts of the 26 km2 study area. The results also showed that the bottlenose dolphins were socializing and foraging to a larger extent in particular areas. This indicates that these higher density areas may be important to the population, particularly for breeding and foraging activities.Genetic analyses showed a clear indication of a genetic break in the mtDNA sequence data which isolated Indo-Pacific bottlenose dolphins sampled off the north and south coasts of Zanzibar. This result was also supported by preliminary microsatellite analyses of a sub-set of the samples available from Zanzibar. Therefore, until additional data from nuclear DNA are available, it is appropriate to treat the Indo-Pacific bottlenose dolphins found off northern and southern Zanzibar as separate management units when assessing the impact from bycatch, dolphin tourism and other anthropogenic threats.The life history characteristics of the Indo-Pacific bottlenose dolphins off Zanzibar were similar to that of bottlenose dolphins from other geographical areas. This indicates that the annual population growth is limited and based on results from other geographical areas likely less than 4%. Sexual maturity, as judged by ovarian activity, developed in females older then 6 years of age and at a body length of about 200 cm. Males exhibited testicular activity when they reached an age of 13 years and at a body length of about 202 cm. Both females and males may live longer than 36 years, based on counts of growth layer groups in teeth. The observed maximum body length for females and males were 233 and 238 cm, respectively.Investigation of fisheries bycatch showed that dolphins were caught in gillnets at sites all round Unguja Island, in the Zanzibar Channel and along the coast of northern Tanzania. Six species of dolphins were recorded from 187 specimens retrieved from bycatch in drift- and bottom set gillnets between 2000 and 2006. Of these, 87 (48%) were Indo-Pacific bottlenose dolphins (Tursiops aduncus), 57 (31%) spinner dolphins (Stenella longirostris), 15 (8%) Risso’s dolphins (Grampus griseus), 15 (8%) Indo-Pacific humpback dolphins (Sousa chinensis), 7 (4%) pan-tropical spotted dolphins (Stenella attenuata), and 2 (1%) common bottlenose dolphins (Tursiops truncatus). Indo-Pacific bottlenose dolphins and Indo-Pacific humpback dolphins were caught primarily in the inshore waters of all areas. Spinner and Risso’s dolphins were caught in areas of deeper waters (depth >100m). Two species not previously recorded in the area were also present in the bycatch, the pan-tropical spotted dolphin and common bottlenose dolphin.Observer programmes conducted onboard fishing boats were used to estimate and assess bycatch of dolphins in drift- and bottom set gill net fisheries operating in Menai Bay, Zanzibar. Six observers were randomly placed on 14 fishing vessels from Kizimkazi Mkunguni and Kizimkazi Dimbani. The observed effort represented 23.6% and 25% of the total annual effort in the driftnet and bottom set gillnet fisheries in the area, respectively. The total annual bycatch for the fisheries was estimated to 13 Indo-Pacific bottlenose dolphins in the driftnet fishery and 4 humpback dolphins in the bottom set gillnet fishery. The estimated annual bycatch represent an annual mortality of 9.6% of the estimated number (136) of Indo-Pacific bottlenose dolphins in the area and 6.3% of the estimated number (63) of humpback dolphins (4/63). These levels of anthropogenic mortalities are not considered sustainable.An investigation of the behaviour of female dolphins off the south coast of Zanzibar in relation to different levels of tourism activity showed that they spent more time travelling with tourist boats present. Further, the results showed that movement and dive patterns of dolphins were affected by the presence of many boats and swimmers and that the presence of a few (1-2) tourist boats (without swimmers) resulted in no detectable changes in movement or dive patterns, providing that the boats were driven with care and not interfering with the heading of the animals i.e. followed issued guidelines. These behavioural changes may be short-term responses to the tourism activities which, if continued, may lead to the long-term consequence that the dolphins leave the area where the dolphin tourism takes place. The apparent changes in dolphin behaviour due to the increased levels of tourism activities may reduce the available time for important behaviours such as foraging and nursing which ultimately may reduce fitness on both individual and population level. It is therefore important to stress the need for a precautionary approach and encourage that the already introduced guidelines, issued by the Department of Fisheries and Marine Products, Zanzibar, are implemented.A socio-economic survey of the dolphin tourism in Kizimkazi, Zanzibar, was conducted by interviewing 50 boat operators, 6 restaurant managers/hoteliers, 50 local residents, 3 diving business managers and 270 tourists. The survey showed that 6735 tourists were involved with dolphin-tourism activities in 2003 representing 10% of the total number of tourists who visited Zanzibar in that particular year. A large proportion of the tourists were Europeans predominantly from the United Kingdom and Italy. The operators were aware of the guidelines for the dolphin tourism, although only 60% said they followed the guidelines. They further admitted that they did not follow the guidelines all the time because when there were many boats on the same group of dolphins, some boat operators ignored the guidelines. About 165 jobs have been created from the dolphin tourism activity in Kizmkazi making it an important contributor to the local economy. However, a large portion (up to 80%) of the income generated was profiting tour companies and/or tourist guides outside the villages.A socio-economy survey was also conducted at Ponta do Ouro, Mozambique. Fifty workers, 50 tourists and 10 tourist resort owners/managers of tourist resorts (including those offering marine recreational services) were interviewed using questionnaires. Workers included those employed at the marine recreational resorts, managers of marine recreational resorts and other people living at Ponta do Ouro. The results showed that only half of jobs at the tourist resorts at Ponta do Ouro were held by native people, and most of these were trained locally by the employers. The majority of tourists frequenting Ponta do Ouro come from inland cities of South Africa and a small proportion where from overseas. A large number of tourists believed that the swim with dolphin activity was good for various reasons, but some recognized the existence of potential negative aspects of the activity. The workers perceived the social impact of marine recreational activities differently, although the majority of workers believed that the recreational activities may affect the environment negatively. The swim with dolphin tourism provided salaries at similar levels to the diving companies, but their contribution to the local economy was low because of the small number of operators.In both Ponta do Ouro and in Menai Bay guidelines have been issued to make the dolphin tourism activities less invasive to the dolphins. The guidelines in the two areas differ in the way that they were issued and how they were formulated. The guidelines in Ponta do Ouro were issued by the tourist operator and address how the activity should be conducted. In Menai Bay the guidelines were issued by the Department of Fisheries and Marine Products, Zanzibar, and these give instructions for how boats and swimmers should behave when interacting with the dolphins. The guidelines in Ponta do Ouro is in a way stricter
|
|
| 7. |
- Duh, Camilla, et al.
(författare)
-
A Scheduling Heuristic For Enhancing Effectiveness Of Machining-Centers With A Multiple APC: Case Study
- 2007
-
Ingår i: The 2nd International Conference on Operations and Supply Chain Management (OSCM), 18 – 20 May, 2007, Bangkok THAILAND. - : New UM Ad. Co. Ltd.. - 9746776371
-
Konferensbidrag (refereegranskat)abstract
- The paper presents a heuristic for scheduling jobs on a machining-center with a multiple-pallets automatic pallet charger (APC). The model is aimed at enhancing the effectiveness of the machining-center through minimizing the total weighted-tardiness of jobs. The multiple-pallet APC allows multiple-setups and a more flexible sequencing of jobs. The proposed heuristic is tested on scheduling jobs on various horizontal machining-centers for manufacturing pump castings at Växjöfabriken Company located in Växjö, Sweden. Machining-centers include MAZAK H400, MAZAK H500, and OKUMA MA600. Results obtained from the study show a 23% to 100% reduction in expected tardiness of jobs compared to that obtained using the company’s scheduling policy. The proposed model is flexible, adjustable, and expandable. Effective scheduling ensures high availability, high level of utilization, and increased productivity.
|
|
| 8. |
- Innabi, Hanan, 1962, et al.
(författare)
-
The change in mathematics teachers' perceptions of critical thinking after 15 years of educational reform in Jordan
- 2007
-
Ingår i: Educational Studies in Mathematics. - : Springer Science and Business Media LLC. - 0013-1954 .- 1573-0816. ; 64:1
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigates how mathematics secondary schools' teachers in \hbox{Jordan} perceive critical thinking and compares teachers' perceptions before and after educational reform. Data were collected from 12 schools twice: in 1988 and in 2004 by interviewing 47 Mathematics teachers. The interview included questions related to teachers' understanding of critical thinking, its role and importance in learning Mathematics, and instructional strategies that could help improve students' critical thinking skills. Results found no improvement in secondary Mathematics teachers' perceptions of critical thinking despite 15 years of educational reform. The majority of Mathematics teachers seemed not to have a clear and adequate understanding of critical thinking. Though most of the teachers claimed they have to teach critical thinking, more than half of them could not suggest any learning situation that could help in fostering critical thinking in Mathematics classes. Also most of the teachers claimed that critical thinking would help students in learning Mathematics; yet less than half were able to give a convincing justification for that. A small percentage of the secondary Mathematics teachers believed they can help all students to foster their critical thinking. It is thus recommended that the concept of critical thinking be transferred from the realm of rhetoric to the field of practice. The paper ends with some recommendations related to the Mathematics teachers training programs in view of the results of this study.
|
|
| 9. |
|
|
| 10. |
|
|
