Usefulness of social tagging in organizing and providing access to the web: An analysis of indexing consistency and quality

This dissertation research points out major challenging problems with current Knowledge Organization (KO) systems, such as subject gateways or web directories: (1) the current systems use traditional knowledge organization systems based on controlled vocabulary which is not very well suited to web resources, and (2) information is organized by professionals not by users, which means it does not reflect intuitively and instantaneously expressed users’ current needs. In order to explore users’ needs, I examined social tags which are user-generated uncontrolled vocabulary. As investment in professionally-developed subject gateways and web directories diminishes (support for both BUBL and Intute, examined in this study, is being discontinued), understanding characteristics of social tagging becomes even more critical. Several researchers have discussed social tagging behavior and its usefulness for classification or retrieval; however, further research is needed to qualitatively and quantitatively investigate social tagging in order to verify its quality and benefit. This research particularly examined the indexing consistency of social tagging in comparison to professional indexing to examine the quality and efficacy of tagging. The data analysis was divided into three phases: analysis of indexing consistency, analysis of tagging effectiveness, and analysis of tag attributes. Most indexing consistency studies have been conducted with a small number of professional indexers, and they tended to exclude users. Furthermore, the studies mainly have focused on physical library collections. This dissertation research bridged these gaps by (1) extending the scope of resources to various web documents indexed by users and (2) employing the Information Retrieval (IR) Vector Space Model (VSM) - based indexing consistency method since it is suitable for dealing with a large number of indexers. As a second phase, an analysis of tagging effectiveness with tagging exhaustivity and tag specificity was conducted to ameliorate the drawbacks of consistency analysis based on only the quantitative measures of vocabulary matching. Finally, to investigate tagging pattern and behaviors, a content analysis on tag attributes was conducted based on the FRBR model. The findings revealed that there was greater consistency over all subjects among taggers compared to that for two groups of professionals. The analysis of tagging exhaustivity and tag specificity in relation to tagging effectiveness was conducted to ameliorate difficulties associated with limitations in the analysis of indexing consistency based on only the quantitative measures of vocabulary matching. Examination of exhaustivity and specificity of social tags provided insights into particular characteristics of tagging behavior and its variation across subjects. To further investigate the quality of tags, a Latent Semantic Analysis (LSA) was conducted to determine to what extent tags are conceptually related to professionals’ keywords and it was found that tags of higher specificity tended to have a higher semantic relatedness to professionals’ keywords. This leads to the conclusion that the term’s power as a differentiator is related to its semantic relatedness to documents. The findings on tag attributes identified the important bibliographic attributes of tags beyond describing subjects or topics of a document. The findings also showed that tags have essential attributes matching those defined in FRBR. Furthermore, in terms of specific subject areas, the findings originally identified that taggers exhibited different tagging behaviors representing distinctive features and tendencies on web documents characterizing digital heterogeneous media resources. These results have led to the conclusion that there should be an increased awareness of diverse user needs by subject in order to improve metadata in practical applications. This dissertation research is the first necessary step to utilize social tagging in digital information organization by verifying the quality and efficacy of social tagging. This dissertation research combined both quantitative (statistics) and qualitative (content analysis using FRBR) approaches to vocabulary analysis of tags which provided a more complete examination of the quality of tags. Through the detailed analysis of tag properties undertaken in this dissertation, we have a clearer understanding of the extent to which social tagging can be used to replace (and in some cases to improve upon) professional indexing.

Relationship between religiosity, religious coping and socio-demographic variables among out-patients with depression or diabetes mellitus in Enugu, Nigeria.

Background: Religion is a powerful coping strategy. Diabetes and depression are common conditions in our environment that induce psychological distress, thus requiring coping for better outcome. Studies indicate that increased religiosity is associated with better outcome in clinical and general populations. Therefore, studies of the distribution of religiosity and religious coping among these populations are essential to improve outcome. Objectives: To assess the association between religiosity, religious coping in depression and diabetes mellitus, and selected sociodemographic variables (age, gender and occupational status). Methods:Using simple random sampling we recruited 112 participants with diabetes and an equal number with depression consecutively, matching for gender. Religiosity was determined using religious orientation scale (revised), religious coping with brief religious coping scale and socio-demographic variables with a socio-demographic questionnaire. Results: Intrinsic religiosity was greater among older people with depression than among older people with diabetes(t=5.02,p<0.001); no significant difference among young people with depression and diabetes(t=1.47,p=0.15).Positive religious coping was greater among older people with depression than among older people with diabetes(t=2.31,p=0.02); no difference among young people with depression and diabetes(t=0.80,p=0.43). Females with depression had higher intrinsic religiosity scores than males with depression(t=3.85,p<0.001); no difference in intrinsic religiosity between females and males with diabetes(t=0.99,p=0.32).Positive religious coping was greater among participants with diabetes in the low occupational status(t=2.96,p<0.001) than those in the high occupational status. Conclusion: Religion is indeed a reliable coping method, most commonly used by the elderly and females with depression. Positive religious coping is more common among diabetic patients who are in the low occupational status.

Medial and lateral hamstrings and quadriceps co-activation affects knee joint kinematics and ACL elongation : a pilot study

Selective enumeration of dairy based strains of probiotic and lactic acid bacteria

Reliable methods for selective enumeration of probiotic and lactic acid bacteria (LAB) are required for improving the functional food quality of probiotics. Various methods were evaluated for selective enumeration of seventeen LAB and probiotic strains. Tested sugars failed to select any species however, improved recovery of total LAB count. The strains were viable and physiologically active within a range of oxygen tension levels, temperature and acidic conditions. Prior methods showed varied results such as De Man Rogosa Sharpe containing bile (MRSB), MRS containing nalidixic acid, paromomycin, neomycin sulphate and lithium chloride (MRS-NPNL), M17 and L. casei (LC) agar failed to select Lactobacillus acidophilus, Bifidobacterium, starter LAB and L. casei strains respectively. However, LC agar appears appropriate for L. paracasei and MRSB for yoghurt starter bacteria in the absence of L. reuteri and L. rhamnosus. The study suggests selective potential of culture media largely depends on target species.

The effect of sliding speed on the wear of steel-tool steel pairs

This study examines the effect of sliding speed and surface temperature on the wear behavior of an unlubricated mild steel-tool steel contact pair using the pin-on-disc test. The operating conditions and contact pair are of interest to the automotive sheet metal stamping industry and the broader metal forming community, where high contact pressures and moderate forming speeds can result in significant frictional heating and thus affect tool life. It will be shown that, while adhesive wear is dominant at the tool steel surface for all sliding speeds examined, the adhesive wear rate is very sensitive to sliding speed during slow speed conditions but relatively insensitive to sliding speed during higher speed conditions. These higher sliding speeds result in high frictional heating, however, the effect of increasing bulk temperature results in a transition from adhesive wear to material removal-dominated mechanisms. It is concluded that there is a distinct difference in the wear response for comparable surface temperature and bulk temperature conditions, at the low to moderate sliding speeds and temperatures examined in this study. The SEM and profilometry analysis show that the technique of increasing sliding speed to replicate bulk temperature conditions (or vice versa), may not result in equivalent wear rates and mechanisms.

A preventative approach to oral health for children in a regional/rural community in south-west Victoria Australia

Abstract Dental caries is a major health problem in most industrialised countries. Childhood dental disease can cause acute pain, difficulty eating resulting in reduced self-esteem and sleep deprivation. The treatment of oral disease using traditional methods is costly and in industrialized countries currently rates the fourth most expensive disease to treat. Dental professionals are currently facing an unfathomable task of how to manage the large burden of consequences associated with caries progression across the world. The Barwon South-West Region of Victoria, Australia is a diverse regional/rural area. Some communities are quite remote. Barwon Health and Colac Area Health Oral Health Services developed an outreach program to improve access to dental services for children. A Minimal Intervention Dentistry approach was incorporated and includes early diagnosis, risk assessment, early detection of mineral loss, non-surgical treatment and preservation of the tooth structure. Kindergartens throughout the region and children in the first year of Primary School are visited by Oral Health Therapists. Teeth are scored according to the International Caries Detection Assessment System and any early 'white spot' lesions identified have fluoride varnish applied. Children receive up to three dental check-ups during the year and given a toothbrush and toothpaste at each visit. Parent engagement sessions are conducted during Visit 2. Examinations and fluoride application take only 3 - 6 minutes for each child, compared with the usual 30 minute appointments in dental clinics. Two virtual chairs have been created as two dental teams visit Kindergartens throughout the Barwon Region, significantly easing pressure at Community dental clinics. The Kinder Wide Smiles program successfully intervened in the oral health of 5,305 children in the region. Most importantly, one of the barriers for children not presenting to static dental clinics for screening has been eliminated.

Population genetic structure of serotine bats (Eptesicus serotinus) across Europe and implications for the potential spread of bat rabies (European bat lyssavirus EBLV-1).

Understanding of the movements of species at multiple scales is essential to appreciate patterns of population connectivity and in some cases, the potential for pathogen transmission. The serotine bat (Eptesicus serotinus) is a common and widely distributed species in Europe where it frequently harbours European bat lyssavirus type 1 (EBLV-1), a virus causing rabies and transmissible to humans. In the United Kingdom, it is rare, with a distribution restricted to south of the country and so far the virus has never been found there. We investigated the genetic structure and gene flow of E. serotinus across the England and continental Europe. Greater genetic structuring was found in England compared with continental Europe. Nuclear data suggest a single population on the continent, although further work with more intensive sampling is required to confirm this, while mitochondrial sequences indicate an east-west substructure. In contrast, three distinct populations were found in England using microsatellite markers, and mitochondrial diversity was very low. Evidence of nuclear admixture indicated strong male-mediated gene flow among populations. Differences in connectivity could contribute to the high viral prevalence on the continent in contrast with the United Kingdom. Although the English Channel was previously thought to restrict gene flow, our data indicate relatively frequent movement from the continent to England highlighting the potential for movement of EBLV-1 into the United Kingdom.

Population genetic structure of the red fox (Vulpes vulpes) in the UK

The red fox (Vulpes vulpes) is common and widely distributed within the UK. It is a carrier or potential carrier of numerous zoonotic diseases. Despite this, there are no published reports on the population genetics of foxes in Britain. In this study, we aim to provide an insight into recent historical movement of foxes within Britain, as well as a current assessment of the genetic diversity and gene flow within British populations. We used 14 microsatellite markers to analyse 501 red fox samples originating from England, southern Scotland and northern France. High genetic diversity was evident within the sample set as a whole and limited population genetic structure was present in British samples analysed. Notably, STRUCTURE analysis found support of four population clusters, one of which grouped two southern England sampling areas with the nearby French samples from Calais, indicating recent (post-formation of the Channel) mixing of British and French populations. This may coincide with reports of large-scale translocations of foxes into Britain during the nineteenth century for sport hunting. Other STRUCTURE populations may be related to geographic features or to cultural practices such as fox hunting. In addition, the two British urban populations analysed showed some degree of differentiation from their local rural counterparts.

Use of micro-algae concentrates for hatchery culture of sandfish, Holothuria scabra

Three Instant Algae® (Reed Mariculture Inc., Campbell, CA, USA, 95008) products: (1) mono-cultured Isochrysis sp. (Haptophyceae) (Isochrysis 1800®); (2) mono-cultured Pavlova sp. (Haptophyceae) (Pavlova 1800®); and (3) mono-cultured Thalassiosira weissflogii (Bacillariophyceae) (TW 1200®) were used to feed sandfish (Holothuria scabra) larvae both singly and in ternary combination to assess their nutritional efficacy. Two-day auriculariae were held at a starting density of 0.3 mL-1 and were initially fed a daily ration equivalent to the dry weight of 10,000 cells mL-1 of Isochrysis 1800®. This ration was increased by the dry weight equivalent of 1000 cells mL-1 of Isochrysis 1800® per day as larval development proceeded. Post-settled larvae fed TW 1200® were significantly larger than those fed the ternary diet, Isochrysis 1800® or Pavlova 1800®. There were significant differences in the mean (±SE) survival of auriculariae and post-settled larvae between treatments and survival to settlement was significantly higher (P < 0.05) for larvae fed TW 1200® (13.7 ± 0.7%) alone. Laval development, competency and survival were significantly correlated with dietary levels of total protein, lipid and nitrogen-free extract (NFE), and with total polyunsaturated fatty acid (PUFA) content of the diets, and the levels of some specific fatty acids (FA). The proportion of late auriculariae with hyaline spheres (day 13), numbers of competent doliolariae (day 15) and the total length of post-settled larvae (day 21) were all positively correlated with dietary NFE and palmitic acid (16:0) contents, as well as dietary EPA: DHA ratio. This study is the first comprehensive assessment of the nutritional value of micro-algae concentrates for sandfish larvae based on their nutrient compositions. Our study confirms the feasibility of using commercially available microalgae concentrates as a sole food source for hatchery culture of sandfish, and is the first to report successful hatchery culture of H. scabra without using live micro-algae. All micro-algae concentrates used in this study proved nutritious for H. scabra larvae and supported normal growth and development and relatively high survival, through settlement. Use of commercially available micro-algae concentrates as a replacement for live micro-algae in sandfish hatcheries supports development of cheaper, simpler larval rearing protocols for this species. Statement of relevance: Hatchery culture of sandfish using micro-algae concentrates, without the use of live micro-algae, is a significant finding that supports development of cheaper, simpler larval rearing protocols for this species. Our study provides detailed nutritional compositional data for the products used and on this basis we were able to deduce new information relating to key nutrients for sea cucumber larvae.

Predicting Successful Aging at One Hundred Years of Age

The present study is based upon a multidimensional model of successful aging. It aims to identify subgroups of centenarians sharing communalities in successful aging profiles, and determine the role of sociodemographic factors and psychological, social, and economic resources on successful aging.

Isolating the photovoltaic junction: atomic layer deposited TiO2-RuO2 alloy Schottky contacts for silicon photoanodes

We synthesized nanoscale TiO2-RuO2 alloys by atomic layer deposition (ALD) that possess a high work function and are highly conductive. As such, they function as good Schottky contacts to extract photogenerated holes from n-type silicon while simultaneously interfacing with water oxidation catalysts. The ratio of TiO2 to RuO2 can be precisely controlled by the number of ALD cycles for each precursor. Increasing the composition above 16% Ru sets the electronic conductivity and the metal work function. No significant Ohmic loss for hole transport is measured as film thickness increases from 3 to 45 nm for alloy compositions >= 16% Ru. Silicon photoanodes with a 2 nm SiO2 layer that are coated by these alloy Schottky contacts having compositions in the range of 13-46% Ru exhibit average photovoltages of 525 mV, with a maximum photovoltage of 570 mV achieved. Depositing TiO2-RuO2 alloys on nSi sets a high effective work function for the Schottky junction with the semiconductor substrate, thus generating a large photovoltage that is isolated from the properties of an overlying oxygen evolution catalyst or protection layer.

Design principles for maximizing photovoltage in metal-oxide-protected water-splitting photoanodes

Metal oxide protection layers for photoanodes may enable the development of large-scale solar fuel and solar chemical synthesis, but the poor photovoltages often reported so far will severely limit their performance. Here we report a novel observation of photovoltage loss associated with a charge extraction barrier imposed by the protection layer, and, by eliminating it, achieve photovoltages as high as 630mV, the maximum reported so far for water-splitting silicon photoanodes. The loss mechanism is systematically probed in metal-insulator-semiconductor Schottky junction cells compared to buried junction p(+) n cells, revealing the need to maintain a characteristic hole density at the semiconductor/insulator interface. A leaky-capacitor model related to the dielectric properties of the protective oxide explains this loss, achieving excellent agreement with the data. From these findings, we formulate design principles for simultaneous optimization of built-in field, interface quality, and hole extraction to maximize the photovoltage of oxide-protected water-splitting anodes.

Engineering interfacial silicon dioxide for improved metal-insulator-semiconductor silicon photoanode water splitting performance

Silicon photoanodes protected by atomic layer deposited (ALD) TiO2 show promise as components of water splitting devices that may enable the large-scale production of solar fuels and chemicals. Minimizing the resistance of the oxide corrosion protection layer is essential for fabricating efficient devices with good fill factor. Recent literature reports have shown that the interfacial SiO2 layer, interposed between the protective ALD-TiO2 and the Si anode, acts as a tunnel oxide that limits hole conduction from the photoabsorbing substrate to the surface oxygen evolution catalyst. Herein, we report a significant reduction of bilayer resistance, achieved by forming stable, ultrathin (<1.3 nm) SiO2 layers, allowing fabrication of water splitting photoanodes with hole conductances near the maximum achievable with the given catalyst and Si substrate. Three methods for controlling the SiO2 interlayer thickness on the Si(100) surface for ALD-TiO2 protected anodes were employed: (1) TiO2 deposition directly on an HF-etched Si(100) surface, (2) TiO2 deposition after SiO2 atomic layer deposition on an HF-etched Si(100) surface, and (3) oxygen scavenging, post-TiO2 deposition to decompose the SiO2 layer using a Ti overlayer. Each of these methods provides a progressively superior means of reliably thinning the interfacial SiO2 layer, enabling the fabrication of efficient and stable water oxidation silicon anodes.

Development of hyaline spheres in late auriculariae of sandfish, Holothuria scabra : is it a reliable indicator of subsequent performance?

This study assessed the influence of diet composition on hyaline sphere (HS) development in auricularia larvae of the sandfish, Holothuria scabra, and the subsequent relationships between the presence and size of hyaline spheres and competency through settlement and early juvenile performance. Two-day old larvae were fed one of three commercially available micro-algae diets that varied in their nutrient compositions: (1) Isochrysis sp. (Haptophyceae); (2) Pavlova sp. (Haptophyceae); and (3) Thalassiosira weissflogii (Bacillariophyceae) or a ternary combination of the three. There were positive significant correlations between HS development in late auriculariae on days 10, 11, 12 and 13 post-fertilisation, and the proportion of competent doliolariae on day 15, post-settlement size (day 21) and post-settlement survival (day 25). The dietary components that most strongly influenced these relationships were carbohydrates and the n-3 polyunsaturated fatty acids arachidonic acid (ARA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Our result confirm the strong relationship between HS formation in late auriculariae of sandfish and subsequent larval competency through settlement. As such, the presence and size of HS is a reliable indicator of subsequent performance for sandfish. Given that HS development was influenced by the nutrients available to sandfish auriculariae, there is clear opportunity for development of more appropriate diets for hatchery culture of this species that will improve HS formation and larval performance supporting improved hatchery production. Statement of relevance Our results have confirmed that for sandfish larvae, the presence and size of HS at the end of the auricularia stage, is indeed a reliable indicator of subsequent performance. Our results have also confirmed that HS formation and size is significantly influenced by the nutrient composition of the auricularia diet, and that there are significant positive correlations between HS formation and dietary levels of carbohydrate, EPA:DHA and EPA:ARA ratios. This information provides a strong basis for development of more appropriate diets for sandfish larvae that will improve HS formation and larval performance during hatchery culture and in turn improve hatchery production of this species.