16 research outputs found
The Effects of Sugar Alcohols on The Growth of Cariogenic Bacteria
No full textThe purpose of this study was to examine the potential of sugar alcohols, commonly used as sugar substitutes to reduce the activity of dental caries causing bacteria. Specifically, the sugar alcohols xylitol, erythritol, sorbitol, and mannitol were placed into the growth media of Streptococcus mutans and Lactobacillus acidophilus. The effects on their bacterial growth were observed. 10% xylitol, 10% erythritol, 10% sorbitol, 10% mannitol, 5% xylitol + 5% erythritol, and 3.3% erythritol + 3.3% xylitol + 3.3% sorbitol combinations were compared to the control groups for differences in bacterial growth. S. mutans samples were significantly inhibited by all groups except sorbitol and mannitol. L. acidophilus samples were significantly inhibited by all groups. 10% erythritol reduced bacterial growth the most amongst all of the single sugar alcohol solutions for both bacterial groups. The xylitol + erythritol combination reduced S. mutans growth the most amongst all groups. This suggests that S. mutans may be vulnerable to the synergistic effects of more than one sugar alcohol and further research should be conducted to analyze their usefulness
A case study in the evaluation of English training courses using a version of the CIPP model as an evaluative tool
No full textThis thesis presents an evaluative case study of the 20 English training courses offered in the Applied English Department (AED) of an Institute, given the pseudonym W.G, in southern Taiwan. No evaluation had been done since the AED had been set up and using Stufflebeam’s CIPP (Context, Input, Process and Product) evaluation model this research was carried out. The purpose of the research was to attempt, through the gathering of qualitative data from a variety of sources and using a variety of research instruments, an evaluation of the 20 English training courses which were designed for and taken by students who hoped, mainly, to become children's English language teachers. The courses were examined through four key components, namely, "course aims and objectives", "course contents and materials", "course conduct and teaching-learning process" and "assessment and student performance". Data were gathered through questionnaires, interviews and the review of existing documents and was obtained from current students, directors of the AED, instructors, alumni and employers of alumni. The resultant data served to present a comprehensive overview of the AED and the 20 English training courses and furnished evidence sufficient to allow for a number of recommendations for improvement and change to emerge. Fundamentally it is not clear that there is sufficient congruence of students needs and the courses offered. It emerged that the AED would probably benefit from a refocusing of student needs, a review of AED structures and governance, uniform syllabus design and presentation, a review of student feedback on instructor performance and a number of fundamental adjustments to the courses, in particular, their content, teaching methodology and assessment. Overall the AED had many positive aspects all of which could be built on and added to as the results of the data suggested. It emerged that the CIPP evaluation model has, in the educational context, a lot to commend it and this has been illustrated in this research. If followed carefully it covers all aspects and features of a program and provides a methodical, all-embracing design which can produce useful material for exploration and adoption if appropriate. It is in most cases a positive program enhancing exercise designed to develop rather than close existing programs
A case study of a policy decision: anonymous marking with special reference to the university of Durham in 1994
No full textBroken down into four separate Chapters, this thesis presents a study of anonymous marking, with special reference to the experience of the University of Durham which introduced a policy of anonymous marking in 1994. It is a study of a single university, and of a very recent change. The thesis adopts a range of different approaches. Chapter One identifies the principles underlying anonymous marking and examines them in the context of the mission, aims and objectives of a university. Chapter Two reviews the literature which has sought various explanations for women achieving a lower proportion of first and third class degrees compared to men, suggesting that more attention should be paid to investigating the differential performance of men and women in individual subjects rather than for degrees as a whole; the pattern of results in the one not being the same as the pattern of results in the other. The hypothesis that sex bias in marking lies behind this pattern is shown to be inconclusive. As a result, the positions of a number of high profile individuals and educational organisations, which advocate the widespread introduction of anonymous marking based on the fact that sex bias in marking has been proven to exist, are shown to be misplaced and possibly premature. In Chapter Three, the practical operation of a newly implemented system of anonymous marking, and the processes involved in the run up to, and after, the policy decision to introduce the system at the University of Durham, are viewed in a case study. The university is analysed as a political system in which the policy process is understood by identifying the different interests involved. The practical implications - in terms of costs, time, administration, anonymity and morale - for all members of the university are considered against the criteria for anonymous marking, and the aims and objectives of the university. In the concluding Chapter it is recommended that higher education institutions contemplating introducing anonymous marking take a close look at the practicability and desirability of such a system, particularly in the light of other developments in higher education, and the feelings of some of the academic staff and of the student community who did not like to feel anonymous. If a system of anonymous assessment is to be introduced it should be done carefully, with wide consultation and with a clear view as to what the system is being designed to achieve, heeding the lessons and the practical recommendations of this study. Otherwise good objectives will be poorly served by poor policy changes
Author Correction: Comprehensive analysis of chromothripsis in 2,658 human cancers using whole-genome sequencing
No full textauthor correctio
The female protective effect in autism spectrum disorder is not mediated by a single genetic locus
No full textBackground: A 4:1 male to female sex bias has consistently been observed in autism spectrum disorder (ASD). Epidemiological and genetic studies suggest a female protective effect (FPE) may account for part of this bias; however, the mechanism of such protection is unknown. Quantitative assessment of ASD symptoms using the Social Responsiveness Scale (SRS) shows a bimodal distribution unique to females in multiplex families. This leads to the hypothesis that a single, common genetic locus on chromosome X might mediate the FPE and produce the ASD sex bias. Such a locus would represent a major therapeutic target and is likely to have been missed by conventional genome-wide association study (GWAS) analysis. Methods: To explore this possibility, we performed an association study in affected versus unaffected females, considering three tiers of single nucleotide polymorphisms (SNPs) as follows: 1) regions of chromosome X that escape X-inactivation, 2) all of chromosome X, and 3) genome-wide. Results: No evidence of a SNP meeting the criteria for a single FPE locus was observed, despite the analysis being well powered to detect this effect. Conclusions: The results do not support the hypothesis that the FPE is mediated by a single genetic locus; however, this does not exclude the possibility of multiple genetic loci playing a role in the FPE.Intellectual and Developmental Disabilities Research Center at Washington University (NIH/NICHD) [P30 HD062171]; Simons Foundation (SFARI) [307705]; Canadian Institutes of Health Research; [R01 HD042541]SCI(E)[email protected]; [email protected]
Author Correction: A multiplexed, paired-pooled droplet digital PCR assay for detection of SARS-CoV-2 in saliva
No full textAuthor Correction: Pan-cancer analysis of whole genomes
No full textCell adhesion molecules are ubiquitous in multicellular organisms, specifying precise cell-cell interactions in processes as diverse as tissue development, immune cell trafficking and the wiring of the nervous system(1-4). Here we show that a wide array of synthetic cell adhesion molecules can be generated by combining orthogonal extracellular interactions with intracellular domains from native adhesion molecules, such as cadherins and integrins. The resulting molecules yield customized cell-cell interactions with adhesion properties that are similar to native interactions. The identity of the intracellular domain of the synthetic cell adhesion molecules specifies interface morphology and mechanics, whereas diverse homotypic or heterotypic extracellular interaction domains independently specify the connectivity between cells. This toolkit of orthogonal adhesion molecules enables the rationally programmed assembly of multicellular architectures, as well as systematic remodelling of native tissues. The modularity of synthetic cell adhesion molecules provides fundamental insights into how distinct classes of cell-cell interfaces may have evolved. Overall, these tools offer powerful abilities for cell and tissue engineering and for systematically studying multicellular organization. Synthetic cell adhesion molecules yield customized cell-cell interactions with adhesion properties that are similar to native interactions, and offer abilities for cell and tissue engineering and for systematically studying multicellular organization
Author Correction: Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples
No full text: Correction to this paper has been published: https://doi.org/10.1038/s41467-020-20128-w
Apocalypticisim in the fiction of William S. Burroughs, J.G. Ballard, and Thomas Pynchon.
No full textApocalypse should not be thought of as merely a synonym for chaos or disaster or cataclysmic upheaval; more properly we should think of disclosure, unveiling and revelation. The exact status of literary apocalyptic is the subject of some debate, and in an attempt to help clarify matters an introductory historical survey examines both the formal characteristics of apocalypse and the various critical positions taken in regard to the genre's social influence. Texts considered in the chapter include the Revelation of John and Thomas Pynchon's short story Entropy (1959); theoretical works by Frank Kermode, John Barth, and Jean Baudrillard (amongst others) are also discussed. Chapter One traces the development of William S. Burroughs's apocalyptic sensibility through readings of his correspondence with Allen Ginsberg and the novel The Naked Lunch (1959); the latter's apocalyptic title referring to the "frozen moment when everyone sees what is on the end of every fork". Chapter Two considers Burroughs's experiments with the "cut-ups" and their application in a number of texts, most notably Nova Express (1964). Chapter Three is concerned with Burroughs's work in the 1970s and 80s, and specifically his concept of Here to Go, a theory of mutability presented as a transcendental antidote to the threat of nuclear annihilation (the author's alleged misogyny and the views of radical US feminists are also taken into account). Chapters Four and Five explore the apocalyptic fiction of J. G. Ballard; topics covered include Ballard's concept of inner space, his debt to Surrealism, and the coded landscapes of his more experimental texts; in particular the "condensed novels" which comprise The Atrocity Exhibition (1970). A concluding chapter returns to the work of Thomas Pynchon, offering a reading of Gravity's Rainbow (1973) which allows us to consider his treatment of such related themes as Paranoia, Holocaust, Apocalypse, and finally, Counterforce
