The role of background knowledge in reading comprehension of subject-specific texts

This thesis investigates the impact of background knowledge in L2 reading comprehension of subject-specific texts, in particular its interaction with grammar knowledge. It explores how different levels of discipline-related background knowledge, grammar knowledge, and self-reported familiarity affect individual differences in L2 reading comprehension in terms of its outcomes and process. A number of studies made assumptions about readers’ knowledge based on their study disciplines or reports by readers themselves, and thus this study also explores the difference between two operationalizations: tested background knowledge and self-reported familiarity. A mixed-methods approach was used by combining two studies: a testing study and a think-aloud study. Altogether 404 students of the School of Economics and Business, University of Ljubljana, Slovenia took part in the study; 22 in the piloting study and 382 in the main study, out of which 358 were engaged in the testing study and 24 in the think-aloud study. The quantitative and qualitative datasets were obtained from five research instruments: a grammar test, a test of discipline-related background knowledge, a reading comprehension test based on three finance texts, a post-reading questionnaire, and think-aloud verbal protocols. The results of multiple regression revealed that tested background knowledge was a significant medium strength predictor of reading comprehension, slightly stronger than grammar knowledge. In contrast, self-reported familiarity was not found to impact reading comprehension and was not its predictor. This evidence casts doubt over self-reporting as an operationalization of knowledge in L2 reading. Apart from having a facilitative effect on L2 reading comprehension, background knowledge was found to have compensatory and additive roles when interacting with grammar knowledge. The findings showed that readers with higher discipline-related background knowledge could use it to make up for lower grammar knowledge and vice versa, thus suggesting the compensation effect between the two variables. In addition, the results revealed that readers were able to use their background knowledge regardless of their level of grammar knowledge, albeit slightly less at higher levels of grammar knowledge. This finding suggests that the threshold hypothesis could not be supported. Finally, the group of students with both high background knowledge and high grammar knowledge outperformed other groups in reading comprehension, which suggests that the two variables affect reading comprehension in an additive way. The qualitative data from verbal protocols in the think-aloud study and readers’ scores from the testing study were obtained to compare the processing patterns and strategies used by readers with high and low background knowledge. Although both groups were found to use the same types of strategies, they differed in the frequency of their use. While the high background knowledge group used more correct paraphrases, elaboration, inferences, and evaluating, the low knowledge group adopted a more local-level approach by paying more attention to individual words, phrases, and sentences and reporting on various comprehension problems and inability to see the bigger picture. The results suggest differences between the groups with different levels of background knowledge with regard to semantic and pragmatic processing at the local and global level. Analysis of the verbal protocol and post-questionnaire data revealed that specialist vocabulary was the main source of difficulty in L2 reading comprehension of subject-specific texts

An Application of Subgroup Discovery Algorithm on the Case of Decentralization and Quality of Governance in EU

This paper analyses a statistical relationship between the decentralization of the EU countries and the quality of their governance. The degree of decentralization is measured from a fiscal and political point of view, and the quality of governance by multiple indicators and citizen opinions. The paper presents a subgroup discovery algorithm which is capable of analysing two sets of several variables, and uses it for the analysis of EU countries. The paper is one of the first to use the data mining methods from the social sciences domain. The used algorithm has discovered some interesting patterns which show a desired relationship. We have discovered that the proportion of public sector employees is one of the most important indicators, which strongly correlates with the degree of trust in the European and national institutions, the government effectiveness and the perception of corruption

The Ecology of Signal Crayfish in Two Large Ultra-Oligotrophic Ecosystems: Crater Lake and Lake Tahoe

Invasive species have become an increasing problem in the Western United States particularly when there are multiple stressors (e.g., invasive species and eutrophication) occurring to ecosystems. Invasive omnivores can present unique problems for aquatic ecosystems by having both direct and indirect impacts on native benthic invertebrates and vertebrates. Omnivorous crayfish, for example, strongly influence littoral habitats and biota with their foraging habits, creating both direct and indirect effects on trophic interactions in aquatic systems. Once they invade, these crayfish can ultimately dominate freshwater ecosystems. This dissertation investigates the distribution, density changes, and the direct and indirect impacts of the invasive signal crayfish (Pacifastacus leniusculus) in two oligotrophic lentic ecosystems in the western United States; Lake Tahoe (CA-NV) and Crater Lake (OR). In chapter 1, I investigate the distribution, movement, and feeding behavior of invasive signal crayfish in Crater Lake. This lake population presents a unique opportunity to understand the movement of crayfish in a recently expanding population. I used minnow traps and snorkeling to determine crayfish distribution and stable isotope ratios of δ13C and δ15N to determine the flow of organic matter through the food web, trophic position, and percent benthic reliance. Depth gradient minnow traps demonstrate that crayfish densities can live as deep as 250 m. Trap and snorkel surveys from 2008 to 2013 indicate an expansion of crayfish from 44% to 78% of the littoral zone. Summer water temperature in Crater Lake has been warming, which may increase the recruitment of individuals and expand habitat availability for growth. Between 1965 and 2014 the nearshore surface temperature increased by 3.5°C. Principal component analysis revealed a positive relationship between crayfish occupation and cobble and boulder habitats of the lake. Crayfish in the littoral zone rely heavily (97.4%) on littoral-benthic carbon sources indicating their potential for impacting native invertebrate communities and the overall dynamics of Crater Lake’s ecosystem. Our findings indicate, however, that deeper water crayfish also may rely on littoral benthic energy resources. Crayfish movement to deeper waters may be subsidizing generally nutrient poor, deep-water habitats with littoral energy through excretion and egestion, where physical conditions are stable and natural perturbation is low.In Chapter 2, I quantify the influence of this early, expanding invasion in Crater Lake to littoral zone ecology by evaluating their influence on zoobenthic consumer biomass and basal algal biomass. Benthic invertebrate biomass was 77% lower in hard substrate and 78% lower in soft substrate areas with crayfish present than in crayfish-absent locations. Using Bayesian, stable isotope mixing models, dietary preferences of crayfish at three locations with varying crayfish densities were quantified. Only slight variations in crayfish diet were detected between the three locations where crayfish have been established, the outer boundary of crayfish expansion, and the middle of the crayfish population indicating that crayfish. Despite differing densities, crayfish are feeding on similar food sources, particularly benthic invertebrates. At low crayfish densities (0 to 10), benthic invertebrate numbers were 222.3±36.6 individuals m-2, while chlorophyll a was 16.8±5.8 mg m-2. At high densities of crayfish (>50), benthic invertebrates had low mean density 3.0±4.2 individuals m-2, while chlorophyll a biomass was high 226.7±48.1 mg m-2. Crayfish are impacting native invertebrate communities and periphyton biomass in Crater Lake by changing trophic interactions in the lake’s littoral zone and altering the lake’s food web.In Chapter 3, I focus on the benthic environment and biodiversity of Lake Tahoe and regional lakes (Donner Lake, Marlette Lake, and Fallen Leaf Lake. Signal crayfish were introduced into the Central Sierra Nevada region of the United States in the late 19th to early 20th century. I used a long-term data set to document highly variable crayfish densities in the littoral zone of Lake Tahoe, showing an increase during the summer months linked to an increase in water temperature (R2 = 0.69, P<0.001). Crayfish responded to site-specific characteristics of the nearshore rather than to lake-wide characteristics; local stream discharge was the only factor that explained a positive increase in lake densities (P< 0.04). Trophic niche models developed from stable isotope measurements of crayfish and nongame fish indicate that crayfish influence the dietary breadth (e.g. niche area) of nongame fish consumers. Crayfish feeding behavior may be forcing nongame fish to feed on a broader set of food resources when crayfish are present. Stable isotope analysis also indicates an overlap of crayfish niche area with other nongame fish and amphibians, indicating interspecific competition between organisms. Our study highlights that local factors influence cold-water crayfish movement and densities in large lakes, as well as potential direct and indirect influences on nongame fish consumers in the littoral region, potentially affecting native biota and ecosystem function. This research has significant implications for understanding the direct and indirect impacts of signal crayfish in oligotrophic food webs, particularly on benthic invertebrate densities. It expands on the current understanding of expansion of signal crayfish and the factors that influence crayfish density. Future research will need to focus on better understanding the life history and mechanisms controlling this species if they are to be controlled in lakes of the Western United States

Confini nel tempo. Un viaggio nella storia dell’Alto Adriatico attraverso le carte geografiche (secoli XVI-XX)/Borders through Time. A Journey through the History of the Upper Adriatic with Geographical Maps (XVI-XX Century)

Lo scopo di questo lavoro è quello di presentare – lungo un percorso iconico/grafico – la storia e l’evoluzione dei confini alto adriatici dal secolo XVI al XX, utilizzando come filo conduttore i prodotti cartografici delle epoche in cui il confine veniva pensato, tracciato, modificato o semplicemente percepito in modo diverso. Le cartografie antiche e quelle moderne risultano essere fonti e strumenti insostituibili nello studio delle dinamiche territoriali, soprattutto in aree geografiche contrassegnate dalla storia come realtà confinarie d’incontro e di compresenza, dove per secoli si sono intrecciate culture, politiche ed economie di popoli e lingue diverse. Ragionare sui confini attraverso la cartografia, significa affrontare la storia degli stati, delle identità e delle culture politiche che hanno accompagnato la storia europea e che hanno conferito un nuovo assetto alle regioni adriatiche. Questi documenti evidenziano come la mobilità dei confini sia da considerarsi una regola, una consuetudine ciclica più che un’eccezione nella storia europea. Essi traducono su carta il respiro, a volte tumultuoso a volte lento, dei confini, un diaframma territoriale sempre alla ricerca di un difficile equilibrio tra un limite naturale e un limite umano, ovvero tra una linea entro cui esercitare la propria sovranità e una linea entro cui identificare la propria nazionalità

Medical emergencies in dental offices in Slovenia and readiness of dentists to handle them

Introduction. Dentists, and all other dental healthcare workers, can expect to face a medical emergency directly or indirectly related to dental treatment. Tis study evaluates the incidence of medical emergencies in dental ofces in Slovenia, the readiness of dentists and possession of specifc medical equipment. Methods. An anonymous online based questionnaire was sent through the Medical Chamber of Slovenia via email to all 1503 active dentists in Slovenia. Te questionnaire was pilot-tested on 25 dentists and improved accordingly. Tirty closedended questions were answered by 289 (19.2 %) dentists. Results. 93.4 % (n=267) of dentists reported a medical emergency in their dental offce. Te most prevalent diagnosis was syncope (1.88-2.44/dentist/year) followed by hypoglycaemia (0.20-0.25/dentist/year), hypertensive crisis (0.4/dentists/year) and anaphylaxis (0.3/dentists/year). Tere were no cardiac arrests reported in the dentists’ entire careers. 85.1 % (n=239) of dentists underwent postgraduate BLS training, 87.4 % (n=209) of them in the last 5 years. Responding dentists estimated that they are most capable of dealing with syncope and least profcient in dealing with stroke, cardiac arrest and a hypertensive crisis. Tey felt generally more prepared to manage than diagnose a medical emergency. Only 58.1 % (n=161) of dentists have access to a self-infating bag with a reservoir, and 54.9 % (n=152) to an oxygen mask. Only 4.0 % (n=11) of them have a full set of equipment recommended by Medical Chamber of Slovenia. Conclusions. Results support modifcation of the undergraduate and postgraduate curriculum for dental students to address specifc medical emergencies and the usage of limited equipment. Tey support more rigorous regulations concerning postgraduate education and specifc equipment for dealing with medical emergencies in dental offices in Slovenia

Cross-over type of supernumerary digastric muscle

A cross-over type asymmetric anomaly of the anterior belly of the right digastric muscle was observed during a cadaveric dissection of the submental region. Three irregularly-shaped supernumerary muscle bundles were found between the anterior bellies of the digastric muscles. Although the anomalies of the digastric muscles are often observed, this complicated pattern has not been previously reported. Our findings and previous reports illustrate the morphogenetic complexity of the anterior belly of the digastric muscle, and their potential importance in confounding clinical evaluation or complicating surgical procedures in the submental region. 

Limnology and food web structure of a large terminal ecosystem, Walker Lake (NV, USA)

Walker Lake is a large, terminal, saline lake in the Western Great Basin of the United States. Diversions have greatly reduced river inflow, which has lead to a decrease in lake volume by 75% since the 1880s. As a result there has been a concomitant increase in salinity levels and alteration to biotic community structure. This study provides a contemporary snapshot of the water quality, phytoplankton-zooplankton biomass, and the lake\u27s food web structure. Water quality and zooplankton were sampled monthly (March to October 2007) from six locations at discrete depths. Nutrient concentrations were highly variable (ammonium levels - 0 to 30 ppb, nitrate - 0 to 12 ppb, total and dissolved phosphorus - 500 to 1000 ppb, and soluble reactive phosphorus - 400 to 600 ppb). The food web structure determined from stable isotope measurements (carbon and nitrogen) and stomach contents suggests benthic resources contributed greatly to fisheries energetics

Variant course of the submental vein

Superficial head and neck vessels are increasingly used in surgical procedures and are especially important in facial transplantation surgeries. We report a variant course of the submental vein observed during a dissection of a 79-year-old-male embalmed cadaver: a left submental vein running caudally across the intermediate tendon of the digastric muscle, separating from the course of the submental artery and emptying directly into the common facial vein in the carotid triangle. Such course may complicate submental island flap harvesting, as well as the graft manipulations and reattachment, since the vein could be damaged during the conventional procedure. This report therefore extends current knowledge of the variations of the vascular anatomy of the head and neck