942 resultados para Gauß Numbers
Resumo:
Forty-six bottled water samples representing 16 brands from Dhaka, Bangladesh were tested for the numbers of total coliforms, fecal indicator bacteria (i.e., thermotolerant Escherichia coli and Enterococcus spp.) and potential bacterial pathogens (i.e., Aeromonas hydrophil, Pseudomonas aeruginos, Salmonella spp., and Shigella spp.). Among the 16 brands tested, 14 (86%), ten (63%) and seven (44%) were positive for total coliforms, E. coil and Enterococcus spp., respectively. Additionally, a further nine (56%), eight (50%), six (37%), and four (25%) brands were PCR positive for A. hydrophila lip, P. aeruginosa ETA, Salmonella spp. invA, and Shigella spp. ipaH genes, respectively. The numbers of bacterial pathogens in bottled water samples ranged from 28 ± 12 to 600 ± 45 (A. hydrophila lip gene), 180 ± 40 to 900 ± 200 (Salmonella spp. invA gene), 180 ± 40 to 1,300 ± 400 (P. aeruginosa ETA gene) genomic units per L of water. Shigella spp. ipaH gene was not quantifiable. Discrepancies were observed in terms of the occurrence of fecal indicators and bacterial pathogens. No correlations were observed between fecal indicators numbers and presence/absence of A. hydrophila lip (p = 0.245), Salmonella spp. invA (p = 0.433), Shigella spp. ipaH gene (p = 0.078), and P. aeruginosa ETA (p = 0.059) genes. Our results suggest that microbiological quality of bottled waters sold in Dhaka, Bangladesh is highly variable. To protect public health, stringent quality control is recommended for the bottled water industry in Bangladesh. Key words: bottled water, fecal indicator bacteria, quantitative PCR, bacterial pathogens, public health risk.
Resumo:
Introduction: The motivation for developing megavoltage (and kilovoltage) cone beam CT (MV CBCT) capabilities in the radiotherapy treatment room was primarily based on the need to improve patient set-up accuracy. There has recently been an interest in using the cone beam CT data for treatment planning. Accurate treatment planning, however, requires knowledge of the electron density of the tissues receiving radiation in order to calculate dose distributions. This is obtained from CT, utilising a conversion between CT number and electron density of various tissues. The use of MV CBCT has particular advantages compared to treatment planning with kilovoltage CT in the presence of high atomic number materials and requires the conversion of pixel values from the image sets to electron density. Therefore, a study was undertaken to characterise the pixel value to electron density relationship for the Siemens MV CBCT system, MVision, and determine the effect, if any, of differing the number of monitor units used for acquisition. If a significant difference with number of monitor units was seen then pixel value to ED conversions may be required for each of the clinical settings. The calibration of the MV CT images for electron density offers the possibility for a daily recalculation of the dose distribution and the introduction of new adaptive radiotherapy treatment strategies. Methods: A Gammex Electron Density CT Phantom was imaged with the MVCB CT system. The pixel value for each of the sixteen inserts, which ranged from 0.292 to 1.707 relative electron density to the background solid water, was determined by taking the mean value from within a region of interest centred on the insert, over 5 slices within the centre of the phantom. These results were averaged and plotted against the relative electron densities of each insert with a linear least squares fit was preformed. This procedure was performed for images acquired with 5, 8, 15 and 60 monitor units. Results: The linear relationship between MVCT pixel value and ED was demonstrated for all monitor unit settings and over a range of electron densities. The number of monitor units utilised was found to have no significant impact on this relationship. Discussion: It was found that the number of MU utilised does not significantly alter the pixel value obtained for different ED materials. However, to ensure the most accurate and reproducible MV to ED calibration, one MU setting should be chosen and used routinely. To ensure accuracy for the clinical situation this MU setting should correspond to that which is used clinically. If more than one MU setting is used clinically then an average of the CT values acquired with different numbers of MU could be utilized without loss in accuracy. Conclusions: No significant differences have been shown between the pixel value to ED conversion for the Siemens MV CT cone beam unit with change in monitor units. Thus as single conversion curve could be utilised for MV CT treatment planning. To fully utilise MV CT imaging for radiotherapy treatment planning further work will be undertaken to ensure all corrections have been made and dose calculations verified. These dose calculations may be either for treatment planning purposes or for reconstructing the delivered dose distribution from transit dosimetry measurements made using electronic portal imaging devices. This will potentially allow the cumulative dose distribution to be determined through the patient’s multi-fraction treatment and adaptive treatment strategies developed to optimize the tumour response.
Resumo:
The degree of diversity or similarity detected in comets depends primarily on the lifetimes of the individual cometary nuclei at the time of analysis. It is inherent in our understanding of cometary orbital dynamics and the seminal model of comet origins that cometary evolution is the natural order of events in our Solar System. Thus, predictions of cometary behaviour in terms of bulk physical, mineralogical or chemical parameters should contain an appreciation of temporal variation(s). Previously, Rietmeijer and Mackinnon [1987] developed mineralogical bases for the chemical evolution of cometary nuclei primarily with regard to the predominantly silicate fraction of comet nuclei. We suggested that alteration of solids in cometary nuclei should be expected and that indications of likely reactants and products can be derived from judicious comparison with terrestrial diagenetic environments which include hydrocryogenic and low-temperature aqueous alterations. In a further development of this concept, Rietmeijer [1988] provides indirect evidence for the formation of sulfides and oxides in comet nuclei. Furthermore, Rietmeijer [1988] noted that timescales for hydrocryogenic and low-temperature reactions involving liquid water are probably adequate for relatively mature comets, e.g. P/comet Halley. In this paper, we will address the evolution of comet nuclei physical parameters such as solid particle grain size, porosity and density. In natural environments, chemical evolution (e.g. mineral reactions) is often accompanied by changes in physical properties. These concurrent changes are well-documented in the terrestrial geological literature, especially in studies of sediment diagenesis and we suggest that similar basic principles apply within the upper few meters of active comet nuclei. The database for prediction of comet nuclei physical parameters is, in principle, the same as used for the proposition of chemical evolution. We use detailed mineralogical studies of chondritic interplanetary dust particles (IDPS) as a guide to the likely constitution of mature comets traversing the inner Solar System. While there is, as yet, no direct proof that a specific sub-group or type of chondritic IDP is derived from a specific comet, it is clear that these particles are extraterrestrial in origin and that a certain portion of the interplanetary flux received by the Earth is cometary in origin. Two chondritic porous (CP) IDPS, sample numbers W701OA2 and W7029CI, from the Johnson Space Center Cosmic Dust Collection have been selected for this study of putative cometary physical parameters. This particular type of particle is considered a likely candidate for a cometary origin on the basis of mineralogy, bulk composition and morphology. While many IDPs have been subjected to intensive study over the past decade, we can develop a physical parameter model on only these two CP IDPs because few others have been studied in sufficient detail.
Resumo:
To overcome the challenge of finding placements for large student numbers, QUT has partnered with community organisations to enable students to work on community-based projects addressing a community need. Students work in interdisciplinary teams with the community organisation to resolve issues and identify solutions to suit the organisation and client base. This paper will describe the community engaged learning pedagogy that is employed in the subject and will consider the benefits and challenges to law students of working collaboratively and developing community relationships. Critical appraisal of the legal system and the role of lawyers and analysis of the professional and ethical responsibilities legal practitioners is a focus of the subject. Explicit emphasis is placed on developing a sense of social responsibility and inculcating a pro bono ethos. Students attend workshops on topics such as reflective practice, cultural competencies, client solutions, collaborative practice and ethical obligations. This paper will discuss the challenges in creating the new legal clinic subject, benefits to students and community partners, and the results of initial student evaluation of the subject.
Resumo:
Detailed mechanisms for the formation of hydroxyl or alkoxyl radicals in the reactions between tetrachloro-p-benzoquinone (TCBQ) and organic hydroperoxides are crucial for better understanding the potential carcinogenicity of polyhalogenated quinones. Herein, the mechanism of the reaction between TCBQ and H2O2 has been systematically investigated at the B3LYP/6-311++G** level of theory in the presence of different numbers of water molecules. We report that the whole reaction can easily take place with the assistance of explicit water molecules. Namely, an initial intermediate is formed first. After that, a nucleophilic attack of H2O2 onto TCBQ occurs, which results in the formation of a second intermediate that contains an OOH group. Subsequently, this second intermediate decomposes homolytically through cleavage of the O-O bond to produce a hydroxyl radical. Energy analyses suggest that the nucleophilic attack is the rate-determining step in the whole reaction. The participation of explicit water molecules promotes the reaction significantly, which can be used to explain the experimental phenomena. In addition, the effects of F, Br, and CH3 substituents on this reaction have also been studied.
Resumo:
OBJECTIVE: To identify chromosomal copy numbers of frequent genetic aberrations within squamous cell carcinomas (SCCs) and solar keratoses (SKs), and provide further evidence to support or challenge current dogma concerning the relationship between these lesions. DESIGN: Retrospective analysis of genetic aberrations in DNA from SK and SCC biopsy specimens by comparative genomic hybridization. SETTING: University-based research laboratory in Queensland, Australia. PATIENTS: Twenty-two biopsy specimens from patients with diagnosed SKs (n = 7), cutaneous SCCs (n = 10), or adjoining lesions (n = 5). MAIN OUTCOME MEASURES: Identification of frequent genetic aberrations both specific to SK and SCC and shared by these lesions to investigate their clonal relationship. RESULTS: Shared genomic imbalances were identified in SK and SCC. Frequent gains were located at chromosome arms 3q, 17q, 4p, 14q, Xq, 5p, 9q, 8q, 17p, and 20q, whereas shared regional losses were observed at 9p, 3p, 13q, 17p, 11p, 8q, and 18p. Significant loss of 18q was observed only in SCC lesions. CONCLUSIONS: Our results demonstrate that numerous chromosomal aberrations are shared by the 2 lesions, suggesting a clonal relationship between SK and SCC. Additionally, the genomic loss of 18q may be a significant event in SK progression to SCC. Finally, the type and frequency of aberrations suggests a common mode of tumorigenesis in SCC-derived tumors.
Resumo:
A polymorphism of the angiotensin I converting enzyme (ACE) gene has recently been reported and analysis of this polymorphism has indicated that it is associated with several cardiovascular diseases. However, the results are still controversial and such association has not yet been established conclusively. To determine whether the ACE gene may be responsible for essential hypertension in a Japanese population, we also compared the distribution of genotypes and the allele frequency of this polymorphism in our findings of a Japanese population with these features in other countries. Eighty-seven hypertensive patients with a family history of essential hypertension and 95 normotensive patients whose parents had no such history were enrolled in the study. Polymorphism of the ACE gene was determined by using the polymerase chain reaction. Homozygotes for this polymorphism had either a 490-bp band (II) or a 190-bp band (DD) and heterozygotes had both bands (ID). In hypertensive subjects, the numbers and frequency of the ACE genotypes were: II, 44 (0.51); ID, 26 (0.30); DD, 17 (0.19). In normotensive subjects these were: II, 35 (0.37); ID, 43 (0.45); DD, 17 (0.18). There were no significant differences between the two groups in derived allele frequencies (chi 2 = 1.41). The difference between the overall allelic frequency in Japan and that reported in several other countries was significant. We did not find any association between ACE gene polymorphism and essential hypertension in Japan. However, there were significant differences in derived allele frequencies between our findings in a Japanese population and those reported from Europe and Australia.
Resumo:
Acoustic sensors can be used to estimate species richness for vocal species such as birds. They can continuously and passively record large volumes of data over extended periods. These data must subsequently be analyzed to detect the presence of vocal species. Automated analysis of acoustic data for large numbers of species is complex and can be subject to high levels of false positive and false negative results. Manual analysis by experienced surveyors can produce accurate results; however the time and effort required to process even small volumes of data can make manual analysis prohibitive. This study examined the use of sampling methods to reduce the cost of analyzing large volumes of acoustic sensor data, while retaining high levels of species detection accuracy. Utilizing five days of manually analyzed acoustic sensor data from four sites, we examined a range of sampling frequencies and methods including random, stratified, and biologically informed. We found that randomly selecting 120 one-minute samples from the three hours immediately following dawn over five days of recordings, detected the highest number of species. On average, this method detected 62% of total species from 120 one-minute samples, compared to 34% of total species detected from traditional area search methods. Our results demonstrate that targeted sampling methods can provide an effective means for analyzing large volumes of acoustic sensor data efficiently and accurately. Development of automated and semi-automated techniques is required to assist in analyzing large volumes of acoustic sensor data. Read More: http://www.esajournals.org/doi/abs/10.1890/12-2088.1
Resumo:
Spokes-characters are ‘...animated beings or objects, created to promote a product, service or idea’ (Phillips 1996, p.155). They were first used in the late 1800s when they emerged as registered trademarks, but the use of spokes-characters for marketing communications has since grown, owing to their ability to remind consumers about a product, transfer positive associations to a brand, and give a corporate company a more ‘personal’ face (Callcott and Lee 1995). One example is the Michelin Man, who has served as spokes-character for Michelin tyres since 1898, after starting out in print advertising. Spokes-characters have become important brand representatives, no longer seen as simply entertaining cartoons featured in television and magazine advertisements. Corporations have now extended their use to interactive, social media platforms, where a consumer can be ‘friends’ with a spokes-character via Facebook, read their comments on the latest iPhone release through Twitter, and watch their family histories being documented on YouTube (see Figure 1). The interactions that consumers once had with two-dimensional spokes-characters have undergone significant transformation in the digital space. With spokes-character Facebook pages achieving significant numbers of ‘likes’ and interactions with consumers, one question concerns whether this strategy is creating characters that are more engaging than the brands they represent, and what impact this has on brand outcomes.
Resumo:
Cytogenetic analysis is a powerful tool that allows analysis of chromosomal aberrations associated with diseased states. In particular, a combination of cytogenetic techniques has allowed the identification of aberrations associated with cancer development, including cancers of the skin. This chapter provides a comprehensive overview of cytogenetic alterations in basal and squamous cell carcinomas of the skin. These two distinct lesions have altered karyotypes that are consistent with their malignant potential. Basal cell carcinomas, although relatively stable lesions, are highly associated with recurrent aberrations of chromosomes 6, 7, 9 and X, as detected by a number of cytogenetic techniques. Squamous cell carcinomas, on the other hand are associated with a much higher degree of instability, involving aberrations of chromosomes 3, 7, 8, 11, 13, 17 and 18, as detected using a number of cytogenetic techniques. Overall, the numbers and types of aberrations associated with basal and squamous cell carcinoma, define the characteristic behaviour associated with these lesions and identification of these aberrations may aid in the understanding of malignant potential, prognosis and treatment of these skin cancers.
Resumo:
Australia is currently experiencing a resources boom and jobs in the male dominated fields of construction and engineering are at a premium. Employment in the construction industry, historically and today, is overwhelmingly male and, with an ageing population this predominately older male workforce will be retiring in greater numbers in the coming decade. Despite more that 25 years of anti- discrimination legislation and equal opportunity legislation these industries still employ few women in operational roles. This paper investigates the issue of the low representation of women in the construction industry. Our investigation involves the analysis of 95 organisation progress reports on the equal opportunity strategic programs in the construction industry. Findings indicate that this industry is not engaging with equal employment opportunity programs and further that equity outcomes for women in the industry are not evident.
Resumo:
This article argues that a semantic shift in the crowd in Vietnam over the last decade has allowed public space to become a site through which transgressive ideologies and desires may have an outlet. At a time of accelerating social change, the state has effectively delimited public criticism yet a fragile but assertive form of Vietnamese democratic practice has arisen in public space, at the margins of official society, in sites previously equated with state control. Official state functions attract only small audiences, and rather than celebrating the dominance of the party, reveal the disengagement of the populace in the party's activities. Where crowds were always a component of state (stage)-managed events, now public spaces are attracting large numbers of people for supposedly non-political activities which may become transgressive acts condemned by the regime. In support of the notion that crowding is an opening up of the possibility of more subversive political actions, the paper presents an analysis of recent crowd formations and the state's reaction to them. The analysis reveals the modalities through which popular culture has provided the public with the means to transcend the constraints of official, authorized, and legitimate codes of behaviour in public space. Changes in the use of public space, it is argued, map the sets of relations between the public and the state, making these transforming relationships visible, although fraught with contradictions and anomalies.