5,900 research outputs found
Occurrence and Control of Plant-parasitic Nematodes in Irrigation Water â A Review
A literature study was carried out to determine what is currently known about the contamination of irrigation water withplant-parasitic nematodes, and what control measures are currently available. Contamination sources of irrigation waterwith plant-parasitic nematodes were investigated, including wells, boreholes, collected rainwater, ponds, lakes, dams,rivers, municipal water, runoff water, irrigation canals and drainage water in soilless culture. Only when the origin ofirrigation water was a capped borehole was the risk of contamination with plant-parasitic nematodes low. The plantparasiticnematodes of economic importance to grapevine reported to be found in irrigation water were Meloidogynespp., Xiphinema spp., Tylenchulus semipenetrans, Trichodorus sp., Criconemoides xenoplax and Pratylenchus spp. Thedifferent sampling techniques used for the detection and monitoring of plant-parasitic nematodes and the sampling timeand location are listed. The survival and infection potential reported for each species of plant-parasitic nematode found inirrigation water was noted. Serious nematode parasites of grapevines, such as Meloidogyne javanica, can survive for 16 to32 days, M. incognita, for up to 14 days, Pratylenchus, for up to 70 days, T. semipenetrans, for up to 128 days, and X. index,for up to 13 days in irrigation water. All reported techniques used for the management of nematodes in irrigation water arelisted and possible future research into the control of plant-parasitic nematodes in irrigation water is discussed. From thisreview, substantial evidence was obtained of the danger of introducing plant-parasitic nematodes to grapevine productionsites by means of irrigation water
CREATION OF A DIGITAL AFRICAN ARCHIVE
Sabinet Gateway, a non-profit organization that promotes and supports library and information services in Africa, has been awarded a $1,8 million grant from the Carnegie Corporation New York to create an African Online Journal Archive. This archive, the first of its kind to contain purely African content, will make academic inputs from all over Africa available for research purposes to local and international organisations and academic institutions. The aim is to create for the first time a central full-text repository of retrospective journal content that contains important African research across a number of fields, including the medical, social sciences and environmental arenas. These materials have unique value, providing not only the vital groundwork for further or related research but assisting to preserve the heritage of the African continent. Stretching over four years, this project includes the sourcing of African journal content, the negotiation of publisher agreements, digitization and indexing of the journal content and the creation of a front end that will make the journal content easily accessible to end users online. As a result the project aims for the archive to contain approximately 90 000 articles
Cultural diversity: impact on the doctoral candidate-supervisor relationship
A number of aspects influencing the relationship between the doctoral candidate and the supervisor have been identified as impacting on the success of postgraduate research supervision, but the influence of the cultural diversity of doctoral candidates and supervisors on this relationship has not been addressed. Australian universities attract a large percentage of international doctoral candidates and many of these candidates relocate to Australia for the duration of their candidature and have to face the challenges of settling temporarily in a foreign country and working closely with a supervisor from a different cultural background. Through a comparative case study approach, this exploratory study investigated the influence of cultural dimensions on the doctoral candidate-supervisor relationship. Qualitative data obtained through interviews with six cases from various cultural clusters were analysed and compared based on four dimensions of national culture values (Hofstede, 2001). The findings suggest that cultural diversity impacts significantly on the social environment of doctoral candidates, but there is no significant impact on the supervisory relationship due to the acculturation of postgraduate students into the university culture. Cultural diversity is identified as a potential factor influencing the doctoral candidateâsupervisor relationship and this study suggests the development of measures to ensure that cultural misunderstandings in the supervisory relationship are avoided
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Grading Qualitatively with Tablet PCs in CS 50
CS 50 is Harvard Collegeâs introduction to Computer Science for majors and non-majors alike. Each week, our 330 students submit programming assignments comprising hundreds of lines of code that must then be graded. Although we can assess the correctness of some code automatically, some measures of quality require human attention. In Fall 2008, we equipped the courseâs 27 teaching fellows (TFs) with Tablet PCs in order to grade more efïŹciently but no less qualitatively. By blurring the lines between ïŹles and paper, we hoped to facilitate typed and handwritten feedback alike so that grading itself would be not only evaluative but instructive as well. At termâs end, most TFs (63%) reported that grading took less time with a Tablet PC, and nearly half (48%) also reported that they provided students with more feedback because of the same. We present in this paper CS 50âs experience with Tablet PCs along with pedagogical beneïŹts thereof.Engineering and Applied Science
Podcasting Computer Science E-1
In recent months [teachers have] become publishers of content and students subscribers thereof by way of podcasts, feeds of audio, video, and other content that can be downloaded to clients like iTunes and devices like iPods. In the fall of 2005, we ourselves began to podcast Harvard Extension School's Computer Science E-1 in both audio and video formats, the first course within Harvard University to do so. Our goals were to provide students with more portable access to educational content and to involve them in technology itself.To evaluate this experiment, we have analyzed logs and surveys of students. We find that our students valued E-1's podcast more as a vehicle for review (45%) than as an alternative to attendance (18%). We also find that most students (71%) tended to listen to or watch lectures on their computers, with far fewer relying upon audio-only (19%) or video (10%) iPods. We argue, meanwhile, that podcasting, despite its widespread popularity, is but a marginal improvement on trends long in progress. It is this technology's reach that we claim is significant, not the technology itself. Logs suggest that E-1's own podcast, available not only to students but to the public at large, has acquired (as of September 2006) between 6,000 and 10,000 subscribers from over 50 countries. We argue, then, that podcasting offers to extend universities' educational reach more than it offers to improve education itself.Engineering and Applied Science
Die Q1 gemeenskap as een van die grondtipes van die kerk in die Nuwe Testament
The New Testament bears witness to a wide variety of communities, representing a spectrum of ideas and teachings about Jesus and the meaning of his life. In this article these communities are regarded as prototypes of churches which have a certain bearing on
churches and their teachings today. The article aims to investigate communities behind Q as prototypes. It focuses on the community responsible for the first layer of Q material, with the intention of asking whether they might have constituted such a prototype of the
church. To achieve this, the âkingdom of Godâ is studied as their symbolic universe. The result is that, while the Q1 community cannot be called âChristianâ or âchurchâ in the strict sense of the word, it challenges the church by representing the kingdom of God
in a world of uncertainty, danger, and misuse of power. HTS Theological Studies Vol. 63 (2) 2007: pp. 699-71
Die funksie en boodskap van die âvoorwoordâ in 1 KorintiĂ«rs
The function and message of the âprefaceâ in 1 Corinthians Paulâs thanksgiving and confession of faith in 1 Corinthians 1:4-9 fulfil the role of the classical preface to arrest the attention of his audience, to seek their goodwill, and to prepare them for instruction in a delicate matter through insinuation. The Corinthians, who boast of their own excellence and privileges, are confronted with Godâs abundant and undeserved grace which will unite them to the Christ as the beginning, the continuation and the end of their whole life.
A National Union Catalog for Shared Cataloging and Resource Sharing by Southern African Libraries
The Andrew W. Mellon Foundation and the National Library of Estonia organized a Conference on Union Catalogs which took place in Tallinn, in the National Library of Estonia on October 17â19, 2002. The Conference presented and discussed analytical papers dealing with various aspects of designing and implementing union catalogs and shared cataloging systems as revealed through the experiences of Eastern European, Baltic and South African research libraries. Here you can find the texts of the conference papers and the list of contributors and participants.The Andrew W. Mellon Foundation and the National Library of Estonia organized a Conference on Union Catalogs which took place in Tallinn, in the National Library of Estonia on October 17â19, 2002. The Conference presented and discussed analytical papers dealing with various aspects of designing and implementing union catalogs and shared cataloging systems as revealed through the experiences of Eastern European, Baltic and South African research libraries. Here you can find the texts of the conference papers and the list of contributors and participants
CREATION OF A DIGITAL AFRICAN ARCHIVE THROUGH COLLABORATION
Sabinet facilitates collaboration between various role players in the African region in an effort to create the most comprehensive collection of African research content in the world. By collaborating with publishers, libraries and faculty at institutions, Sabinet is bringing together full-text content published in journals and institutional repositories, on a single and easily accessible platform.
The initiative was started in 1998 with a project to collect and make available African journal content online. The aim was, for the first time, to create a central full-text collection of journal content containing important African research across a number of fields, including medical, social sciences and environmental. In 2007, the project was boosted further when Sabinet was awarded a grant from the Carnegie Corporation of New York to retrospectively digitize and make available an archive of the content of journals that was published prior to the start of the initiative. There are now more than 340 journals available online, containing more than 200 000 articles. Recently, Sabinet has extended collaboration with academic institutions by harvesting and incorporating content published in institutional repositories into the central platform. This collection of unique African research content is now available to local and international organisations. The result of this collaboration has a unique value, providing not only the vital groundwork for further or related research but assisting to preserve the heritage of the African continent whilst at the same time providing valuable world-wide exposure to African publishers
Factors Associated with Orthodontically Induced Apical Root Resorption of Maxillary Incisors
Introduction: Resorption of root apices is a ubiquitous occurrence in orthodontic treatment. Although most occurrence of resorption during orthodontic treatment is clinically inconsequential, a small percentage of patients have a severe amount of root structure that is lost. There are factors that are widely accepted as responsible for apical root resorption (RR), such as heavy compressive forces on the periodontal ligament (PDL). Unfortunately, it is still largely unpredictable if one patient will experience more root loss than what is considered normal. Thus, it is of clinical interest to further study what factors play a role in RR. Purpose: The purpose of this study was to utilize Cone Beam Computed Tomography (CBCT) to evaluate whether certain treatment-related and patient-related factors are associated with increased severity of orthodontically induced apical root resorption. Methods: Initial (T1) and final (T2) Digital Imaging and Communications in Medicine (DICOM) CBCT images of patients orthodontically treated at Loma Linda University were imported into OsiriX MD software (version 7.5.1, Pimeo, Bernex, Switzerland) for measuring RR of right and left maxillary central incisors. Using
fiduciary markers at the anterior nasal spine (ANS), posterior nasal spine (PNS), and nasion (Na), movement of the incisors were assessed at three dental landmarks, the incisal edge (I), the center of resistance (C), and the apex (A). Patient treatment records were reviewed for information regarding patient age, gender, ethnicity, medical history, expander appliances used, whether teeth were extracted, and time in treatment. Non-parametric Spearman-Rho correlation tests were performed to determine whether correlations existed between specific directions of tooth movement, time in treatment, or age of the patient and the severity of RR. Kruskal-Wallis and Mann-Whitney U tests were also used to determine differences in RR among groups of ethnicity, gender, expansion treatment, extraction treatment and asthmatics. Results: A total of 291 patients (582 teeth) were included in this study. Total movement at A, intrusion at A and retraction at I were directions of movement that had the highest correlations with RR at 0.344, 0.343, and 0.328 respectively. Time in treatment had a significant but weak correlation with RR of 0.213. There was no correlation with the patient age and amount of resorption. Males had statistically more RR than females. However, males also had statistically more total movement of the root apex. Incisors treated with extraction of two premolars also had more RR but also more total movement at the apex compared to non-extraction treatment. Patients treated with a rapid maxillary expansion appliance or a quad helix had more RR than those treated non-expansion. There were no differences in RR among ethnicities or between asthmatics and non-asthmatics. Conclusions: In our sample, total movement at the apex, intrusion at the apex, and retraction at the incisal edge had the highest correlation with root resorption. Treatment involving rapid palatal expansion and extractions had higher means of resorption. Additionally, there were no differences in severity of resorption among ethnicities or asthmatics and non-asthmatics
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