4 pp. / Regular physical activity is essential for healthy aging, and most adults aged 65 years and older can safely participate in regular physical activity. This article reviews the benefits of physical activity in older adults and provides updated physical activity recommendations and tips for how to start and how to stay active for life.

Bumblebees are a group of valuable pollinators that are declining all over the world. The main reason is believed to be habitat loss due to the changes in agriculture. The changes in agriculture influence the structure of the vegetation and flower abundance, which are of great importance to the abundance of bumblebees. The aims of this study were to get a better understanding of bumblebees and what preferences they might have regarding vegetation height and flower abundance in semi-natural grasslands. This study is based on data collected by a Swedish national environmental monitoring program in 2006-2010. Data on twelve bumblebee species were analysed using a generalized linear model based on the dependent variables of occurrence/ non-occurrence. The target variables used in the analysis were flower abundance, vegetation height and standard deviation of vegetation height. The species-wise analyses mostly showed no or weak positive relationships between the bumblebee occurrence and the three target variables. Grouping the species-wise results into ecologically meaningful guilds and analysing them did not increase the explanatory power of flower abundance or vegetation characteristic, but vegetation height showed significant (positive) results in relation for the forest dwelling species and the species group non-parasite and parasite. The results of this study were considerably weaker than expected. Flower abundance and variation in vegetation height could not explain the occurrence of bumblebees. However, the results of this study show that vegetation height is of importance to the occurrence of bumblebees. Bumblebees in general seem to prefer a higher vegetation height. Based on the findings of this study I would recommend a low intensity of grazing in semi-natural grasslands.

At the bottom tip of the African continent lies South Africa – the economic powerhouse of the continent complimented by its rainbow nation with a myriad of cultures and even more opportunities, but an equal number of pressing challenges: Poverty, inequality, the prevalence of HIV/AIDS, a shortage of skilled people (or rather a surplus of unskilled people), poor quality of basic education, unemployment, and of particular importance for this study, youth unemployment. In September 2011 more than 1.3 million young South Africans aged 15 to 24 years were unemployed, and 1.85 million aged 25 to 34 years were without jobs. Combined these figures represented 71 percent of total unemployment in the third quarter of 2011. As a result, the problem statement central to this study is the expectation that the poor quality of general (basic) education and the lack of purposive entrepreneurship education and training in South African schools will continue to contribute towards high levels of youth unemployment and poverty, as well as the proliferation of dysfunctional communities and increased levels of state dependency among a large part of the country’s population. This study set out in search of answers – answers to questions regarding the impact of entrepreneurship training on the youth in South Africa as the primary objective and the potential for entrepreneurship to serve as the panacea for many of the country’s ills. The end result is a rendering of more than three years of intensive research culminating in valid conclusions and practical, attainable recommendations to promote entrepreneurial activity in the country. The study examines the theories and definitions of entrepreneurship and concludes that entrepreneurship is a combination of opportunity and risk in the presence of extraordinary levels of ‘want’ (desire) to promote self-interest, whether it being monetary reward or the attainment of personal fulfilment, as the main motivational factor driving entrepreneurial behaviour (Schumpeterian theory). The contemporary challenges facing South Africa are expounded to create a platform for the presentment of entrepreneurship as the ‘magical genie’, captured in the ‘bottle’ that is mainly the small and medium sized enterprise (SME) sector in the country, and capable of redressing many of the country’s ills by empowering the youth to take both charge of and responsibility for their own future. The concomitant discussion shows that the ‘genie’ is held firmly in the confines of its ‘bottle’ by barriers obstructing the free flow of an enterprising spirit, confirming that the release of an enterprising spirit among South Africans faces many obstacles to be overcome before the ‘genie’ can be released successfully to work its ‘magic’. The concept of entrepreneurship education is examined to determine whether it is a reality or a myth. The discussion concludes that entrepreneurship is indeed a learnt phenomenon – it can be taught successfully. It is put forward that it can only be deemed a reality to the extent in which measurable evidence of its positive impact on learners exists. This conclusion sets the tone for the empirical research in later chapters by questioning the capacity for effective entrepreneurship education in South Africa. The empirical research conducted for this study includes a pilot study and a national main study focused on examining the impact of entrepreneurship training on young learners in South African secondary schools. It is based upon the attitudinal and intentional approaches to entrepreneurship research and employs six validated entrepreneurship surveys suitable for use with young individuals to respectively measure entrepreneurial attitudes, entrepreneurial intentions, general enterprising tendencies, subjective personal wellbeing, adaptive cognition and innovation skills. A total of 342 learners from secondary schools in the Harrismith region (Free State province) participated in the pilot study, followed by 898 respondents in the pre-testing phase and 751 in the post test phase of the AEG-3 main study and 910 respondents in the pre-testing phase and 749 in the post test phase of the PMY-3 main study. Participants in the main study originated from seven of the nine provinces of South Africa and were mainly female black Africans aged 15 to 17 years attending grades 10 and 11 at secondary schools. The datasets gathered from both the AEG-3 and PMY-3 studies were subjected to extensive statistical analyses by Statistical Consultation Services of the North-West University (Potchefstroom campus). The results lead to the conclusion that the Mini-Enterprise Programme (MEP) of Junior Achievement South Africa (JASA) did not have any visible or practically significant impact on the entrepreneurial attitudes, entrepreneurial intentions, subjective personal wellbeing, adaptive cognition and innovation skills of learners in either of the two samples examined in the empirical research project. This conclusion reaffirms the challenges and barriers associated with releasing the spirit of enterprise among the South African youth. Although entrepreneurship can be taught effectively, it is dependent on long-term strategies providing adequate support to learners with the attitude and aptitude to become competent entrepreneurs, as well as suitable methods for continuous assessment and improvement. It further demands entrepreneurial learning enhanced by an extended period of deliberate practice (the ‘Eureka’-factor proposed in this study) flowing from ‘want’ (desire) on the part of the learner to have any chance of being truly effective. The study concludes that content and methodology borrowed from other countries may not be suited for the South African context. This conclusion exclaims the need for purposive South African entrepreneurship education and training programmes assessed with purposive South African entrepreneurship measuring scales. These conclusions are subsequently used to formulate practical and attainable recommendations for the promotion of effective youth entrepreneurship education and training in the country, including the need to get rid of high expectations, to never give up, stricter selection of learners for enrolment in entrepreneurship education and training programmes (other than those included in basic education), the need for continuous research, embracing the ‘power of one’, and finally, adopting an entrepreneurial solution for what is evidently an entrepreneurial problem. The outcome of this study brings forward the message that the challenge in South Africa is to create entrepreneurs, not young people with the capacity to perform entrepreneurial tricks. True entrepreneurs are not ordinary people, regardless of whether they are born or ‘made’. Although entrepreneurship can be learnt by any person, it takes a very special kind of ‘want’ (desire), determination and practise to become a successful entrepreneur, and even more ‘want’, determination and practise to become an expert entrepreneur. / Thesis (PhD (Business Administration))--North-West University, Potchefstroom Campus, 2013.

At the bottom tip of the African continent lies South Africa – the economic powerhouse of the continent complimented by its rainbow nation with a myriad of cultures and even more opportunities, but an equal number of pressing challenges: Poverty, inequality, the prevalence of HIV/AIDS, a shortage of skilled people (or rather a surplus of unskilled people), poor quality of basic education, unemployment, and of particular importance for this study, youth unemployment. In September 2011 more than 1.3 million young South Africans aged 15 to 24 years were unemployed, and 1.85 million aged 25 to 34 years were without jobs. Combined these figures represented 71 percent of total unemployment in the third quarter of 2011. As a result, the problem statement central to this study is the expectation that the poor quality of general (basic) education and the lack of purposive entrepreneurship education and training in South African schools will continue to contribute towards high levels of youth unemployment and poverty, as well as the proliferation of dysfunctional communities and increased levels of state dependency among a large part of the country’s population. This study set out in search of answers – answers to questions regarding the impact of entrepreneurship training on the youth in South Africa as the primary objective and the potential for entrepreneurship to serve as the panacea for many of the country’s ills. The end result is a rendering of more than three years of intensive research culminating in valid conclusions and practical, attainable recommendations to promote entrepreneurial activity in the country. The study examines the theories and definitions of entrepreneurship and concludes that entrepreneurship is a combination of opportunity and risk in the presence of extraordinary levels of ‘want’ (desire) to promote self-interest, whether it being monetary reward or the attainment of personal fulfilment, as the main motivational factor driving entrepreneurial behaviour (Schumpeterian theory). The contemporary challenges facing South Africa are expounded to create a platform for the presentment of entrepreneurship as the ‘magical genie’, captured in the ‘bottle’ that is mainly the small and medium sized enterprise (SME) sector in the country, and capable of redressing many of the country’s ills by empowering the youth to take both charge of and responsibility for their own future. The concomitant discussion shows that the ‘genie’ is held firmly in the confines of its ‘bottle’ by barriers obstructing the free flow of an enterprising spirit, confirming that the release of an enterprising spirit among South Africans faces many obstacles to be overcome before the ‘genie’ can be released successfully to work its ‘magic’. The concept of entrepreneurship education is examined to determine whether it is a reality or a myth. The discussion concludes that entrepreneurship is indeed a learnt phenomenon – it can be taught successfully. It is put forward that it can only be deemed a reality to the extent in which measurable evidence of its positive impact on learners exists. This conclusion sets the tone for the empirical research in later chapters by questioning the capacity for effective entrepreneurship education in South Africa. The empirical research conducted for this study includes a pilot study and a national main study focused on examining the impact of entrepreneurship training on young learners in South African secondary schools. It is based upon the attitudinal and intentional approaches to entrepreneurship research and employs six validated entrepreneurship surveys suitable for use with young individuals to respectively measure entrepreneurial attitudes, entrepreneurial intentions, general enterprising tendencies, subjective personal wellbeing, adaptive cognition and innovation skills. A total of 342 learners from secondary schools in the Harrismith region (Free State province) participated in the pilot study, followed by 898 respondents in the pre-testing phase and 751 in the post test phase of the AEG-3 main study and 910 respondents in the pre-testing phase and 749 in the post test phase of the PMY-3 main study. Participants in the main study originated from seven of the nine provinces of South Africa and were mainly female black Africans aged 15 to 17 years attending grades 10 and 11 at secondary schools. The datasets gathered from both the AEG-3 and PMY-3 studies were subjected to extensive statistical analyses by Statistical Consultation Services of the North-West University (Potchefstroom campus). The results lead to the conclusion that the Mini-Enterprise Programme (MEP) of Junior Achievement South Africa (JASA) did not have any visible or practically significant impact on the entrepreneurial attitudes, entrepreneurial intentions, subjective personal wellbeing, adaptive cognition and innovation skills of learners in either of the two samples examined in the empirical research project. This conclusion reaffirms the challenges and barriers associated with releasing the spirit of enterprise among the South African youth. Although entrepreneurship can be taught effectively, it is dependent on long-term strategies providing adequate support to learners with the attitude and aptitude to become competent entrepreneurs, as well as suitable methods for continuous assessment and improvement. It further demands entrepreneurial learning enhanced by an extended period of deliberate practice (the ‘Eureka’-factor proposed in this study) flowing from ‘want’ (desire) on the part of the learner to have any chance of being truly effective. The study concludes that content and methodology borrowed from other countries may not be suited for the South African context. This conclusion exclaims the need for purposive South African entrepreneurship education and training programmes assessed with purposive South African entrepreneurship measuring scales. These conclusions are subsequently used to formulate practical and attainable recommendations for the promotion of effective youth entrepreneurship education and training in the country, including the need to get rid of high expectations, to never give up, stricter selection of learners for enrolment in entrepreneurship education and training programmes (other than those included in basic education), the need for continuous research, embracing the ‘power of one’, and finally, adopting an entrepreneurial solution for what is evidently an entrepreneurial problem. The outcome of this study brings forward the message that the challenge in South Africa is to create entrepreneurs, not young people with the capacity to perform entrepreneurial tricks. True entrepreneurs are not ordinary people, regardless of whether they are born or ‘made’. Although entrepreneurship can be learnt by any person, it takes a very special kind of ‘want’ (desire), determination and practise to become a successful entrepreneur, and even more ‘want’, determination and practise to become an expert entrepreneur. / Thesis (PhD (Business Administration))--North-West University, Potchefstroom Campus, 2013.

Η κινητή τηλεφωνία και το διαδίκτυο έχουν φέρει επανάσταση στην επικοινωνία και τον τρόπο ζωής των ανθρώπων. Ένας ολοένα αυξανόμενος αριθμός κινητών τηλεφώνων και άλλων κινητών συσκευών επιτρέπουν στους ανθρώπους να έχουν πρόσβαση στο διαδίκτυο οπουδήποτε βρίσκονται και όποτε θέλουν. Οι υπηρεσίες αυτές εστιάζουν στην αξιοποίηση της γεωγραφικής θέσης που παρέχει το σύστημα GPS παρέχοντας επιπλέον στον χρήστη πληροφορίες για τις υπηρεσίες που αφορούν την γεωγραφική θέση του και την περιοχή γύρω του. Στην εργασία αυτή οι βασισμένες στη θέση υπηρεσίες συνδυάζονται με τεχνικές παροχής συστάσεων και υλοποιείται μια πρότυπη εφαρμογή παροχής συστάσεων για χρήστες κινητών τηλεφώνων σχετικά με φωτογραφίες περιοχών του ενδιαφέροντος τους. Ο χρήστης θεωρείται μέλος ενός κοινωνικού δικτύου και οι συστάσεις που του παρέχονται βασίζονται στην ομοιότητα του χρήστη με τα μέλη του δικτύου του. Οι συστάσεις προκύπτουν από τον υπολογισμό της ομοιότητας του χρήστη με κάθε φίλο του, βάσει ενός συνόλου φωτογραφιών που έχουν βαθμολογήσει και οι δύο. Ο βαθμός ομοιότητας του χρήστη υπολογίζεται με το συντελεστή συσχέτισης του Pearson. Τα άτομα που ικανοποιούν μια καθορισμένη τιμή ομοιότητας αποτελούν τους συμβούλους του χρήστη. Οι φωτογραφίες που παρουσιάζει η εφαρμογή στους χρήστες καθορίζονται από τις βαθμολογίες των συμβούλων για τις φωτογραφίες που δεν έχει βαθμολογήσει ο χρήστης. Στο πλαίσιο της εργασίας περιγράφεται η αρχιτεκτονική που εξυπηρετεί εφαρμογές αυτού του είδους. Επίσης υλοποιείται μια πρότυπη εφαρμογή με την οποία συστήνονται στο χρήστη φωτογραφίες που έχουν βαθμολογήσει οι φίλοι του. / Telecommunications and network technologies have made a revolution in communication and the way people live. The growing number of mobile phones and other mobile devices allows people have access to internet whenever and wherever they are. These services are concentrated in the utilization of geographic position provided by GPS system giving also information about services related with user’s position and the area around him. In this work location based services are combined with recommendation techniques to implement a standard application which provides recommendations to mobile devices users related to photographs from areas which may users are interested in. User is considered as a member of a social network and recommendations provided to him are based on the similarity the user has with other members of his network. Recommendations derive from user to user similarity calculation, on basis of photographs that both users have rate. User’s degree of similarity is calculated with Pearson’s correlation coefficient. Users that satisfy a certain value of similarity constitute the consultants of a user. The photographs presented to users by the application are specified by consultants’ ratings for the photographs that user has not rated. In the context of this work the architecture that serves such applications is described. It is also implemented a standard application which recommends users with photographs that his fellows have rated.

The e-commerce revolution in business can help African countries expand their tourism industry. Africa, with its great wealth in wildlife and unique resorts, can benefit from the ever increasing user population of the Internet, particularly in the USA and Western Europe where most of the tourists to Africa come from (Internet World Stats, 2004). E-commerce which runs on the backbone of the Internet can help the African tourism industry break into international tourism, thus increasing the flows of the much needed foreign currency. As there was little empirical data on the e-commerce activities in the African tourism industry the researcher first and foremost examined a large number of websites in order to paint a picture of the nature and extent of the e-commerce activities in four -African countries. For comparison, websites of tourism organisations from USA and Western Europe were also examined. The surveys revealed that few of the African organisations are embracing e-commerce and that although some websites were comparable to those of their western counterparts the majority had room for considerable improvement. After examining the websites another survey was carried out to find the current progress of e-commerce adoption and usage from the perspective of the African tourism organisations. Analysis of the data collected showed that e-commerce adoption among the tourism organisations was slow. This led to more surveys being carried out to find the barriers to e-commerce among tourism organisations with information-only websites and those whose websites had limited interactive facilities. These surveys revealed that tourism organisations with information-only websites faced more barriers than those with websites which had limited interactive features. They also revealed that the most common barriers were technological and security and legal barriers. The ultimate survey involved finding out from tourism organisations with fully-fledged e-commerce websites how they overcame the e-commerce barriers. The methods used by these organisations to overcome e-commerce barriers together with recommendations made in the surveys carried out earlier were used to formulate recommendations and guidelines for those organisations intending to adopt and e-commerce. The recommendations and guidelines were tested and results showed that they are helpful and easy to follow.

Context. Global Software Development is software work undertaken at geographically separated locations across national boundaries in a coordinated fashion involving real time or asynchronous interaction. Distributed Agile Development aims at the benefits of both Agile Software Development and Global Software Development aiding the distributed teams to overcome the challenges brought by the distribution. Objectives. In this study the author investigates whether a globally distributed company is prepared to be agile, determining hindrances for agile and providing recommendations to mitigate or overcome the detected hindrances. Methods. In this case study, surveys and interviews were used to study the hindrances for agile and literature was used to provide the recommendations towards the detected hindrances. Results. 4 hindrances were detected. Only 1 was justified as necessary for the good performance of the distributed company. Several recommendations to overcome the hindrances were proposed. Both hindrances and proposed solutions were validated by the company representative. Conclusions. We conclude that the studied individuals are willing to be agile. As agile is built bottom-up, the company is prepared to be agile. However, they will not be able to be agile until they overcome or mitigate the detected challenges. In the study, several solutions for it are proposed.

Class of 2017 Abstract / Objectives: To assess the clinical evidence that supports recommendations made on The Dr. Oz Show Methods: This descriptive, retrospective study determined if recommendations made during the first 30 episodes from season 5 of The Dr. Oz Show were supported, not supported, or no literature evidence could be found. The 30 episodes chosen were aired between 4/25/2014 and 7/29/2014. The literature evaluated was from among three databases: PubMed, Embase and Natural Medicines. A total of 82 specific recommendations were assessed. The recommendations included those concerning medications, dietary supplements, medical devices, food and cosmetic products. Two investigators independently researched the literature evidence for each recommendation using a point-grading system. A consensus of agreement was reached for the evaluation of the accuracy for each recommendation. Results: A total of 77 recommendations from among the 30 chosen episodes met inclusion criteria and were therefore analyzed. Among the 77 analyzed recommendations, 30 (38.9%) of them were supported by evidence, 6 (7.7%) of them were not supported by evidence and 41 (53.4%) of them had no evidence found. Conclusions: Overall, less than half of the recommendations in the first 30 episodes of season 5 on The Dr. Oz Show were supported by evidence.

Collaboration and sharing of information are the basis of modern social web system. Users in the social web systems are establishing and joining online communities, in order to collectively share their content with a group of people having common topic of interest. Group or community activities have increased exponentially in modern social Web systems. With the explosive growth of social communities, users of social Web systems have experienced considerable difficulty with discovering communities relevant to their interests. In this study, we address the problem of recommending communities to individual users. Recommender techniques that are based solely on community affiliation, may fail to find a wide range of proper communities for users when their available data are insufficient. We regard this problem as tag-based personalized searches. Based on social tags used by members of communities, we first represent communities in a low-dimensional space, the so-called latent semantic space, by using Latent Semantic Analysis. Then, for recommending communities to a given user, we capture how each community is relevant to both user’s personal tag usage and other community members’ tagging patterns in the latent space. We specially focus on the challenging problem of recommending communities to users who have joined very few communities or having no prior community membership. Our evaluation on two heterogeneous datasets shows that our approach can significantly improve the recommendation quality.

In general, recommender systems attempt to estimate user preference based on historical data. A context-aware recommender system attempts to generate better recommendations using contextual information. However, generating recommendations for specific contexts has been challenging because of the difficulties in using contextual information to enhance the capabilities of recommender systems. Several methods have been used to incorporate contextual information into traditional recommendation algorithms. These methods focus on incorporating contextual information to improve general recommendations for users rather than identifying the different context applicable to the user and providing recommendations geared towards those specific contexts. In this thesis, we explore different context-aware recommendation techniques and present our context-aware coupled matrix factorization methods that use matrix factorization for estimating user preference and features in a specific contextual condition. We develop two methods: the first method attaches user preference across multiple contextual conditions, making the assumption that user preference remains the same, but the suitability of items differs across different contextual conditions; i.e., an item might not be suitable for certain conditions. The second method assumes that item suitability remains the same across different contextual conditions but user preference changes. We perform a number of experiments on the last.fm dataset to evaluate our methods. We also compared our work to other context-aware recommendation approaches. Our results show that grouping ratings by context and jointly factorizing with common factors improves prediction accuracy.