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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
281

Effect of recent L1 exposure on Spanish attrition : an eye-tracking study

Chamorro Galán, Gloria January 2013 (has links)
Previous research has shown L1 attrition to be selective (Gürel 2004) and often restricted to structures at the interfaces between syntax and context/pragmatics, but not to occur with syntactic properties that do not involve such interfaces (Interface Hypothesis, Sorace & Filiaci 2006). This is supported by many studies exploring cross-linguistic influence effects in interface structures, such as the production and/or interpretation of null versus overt pronominal subjects, not only in L1 attriters (Tsimpli et al. 2004, Montrul 2004) but also in other bilingual groups with different language combinations, such as early bilinguals (Paradis & Navarro 2003, Sorace et al. 2009), and advanced late bilinguals (Belletti et al. 2007, Rothman 2009). The current hypothesis is that individual L1 attrition affects only the ability to process interface structures but not knowledge representations themselves (Sorace 2011). In this thesis, we first compared a well-studied syntax-pragmatics interface phenomenon (pronominal subjects in Spanish) with a non-interface structure (the Spanish personal preposition a, also known as Differential Object Marking, DOM). In Spanish, the distribution of null and overt subject pronouns is pragmatically constrained, whereas the presence of the preposition just depends on the animacy and specificity of the direct object. Participants included a group of attrited speakers of L1 Spanish who had been living in the UK for a minimum of 5 years, and a group of Spanish monolinguals. Using a naturalness judgment task and eye tracking while reading, participants were presented with anaphoric sentences in which number cues matched or mismatched predicted antecedent preferences (i.e. null pronoun: subject preference; overt pronoun: object preference). The DOM study also used a mismatch paradigm, crossing preposition presence (al vs. el) with animacy, where an animate object requires the prepositional form al and an inanimate object requires the article el. Offline ratings revealed equal mismatch sensitivity for both groups of participants with both structures. However, eye-tracking measures showed that monolinguals were reliably more sensitive than attriters to the pronoun mismatch, while both groups showed equal on-line sensitivity to the DOM mismatch, which reveals that attrition affects interface structures, but not non-interface structures. Second, we investigated the effects of recent (re)exposure to L1 input on attrition. A second group of attriters carried out the same experiment after having been exposed exclusively to Spanish in a monolingual Spanish-speaking environment for a minimum of a week. Their eye-tracking results patterned with the monolingual group. This novel manipulation shows that attrition effects decrease as a result of L1 exposure, which reveals that bilinguals are sensitive to input changes and that attrition affects online sensitivity rather than causing a permanent change in speakers’ L1 grammatical representations.
282

Validation of diffusive samplers for nitrogen oxides and applications in various environments

Hagenbjörk-Gustafsson, Annika January 2014 (has links)
The overall aim of this thesis was to validate diffusive samplers for measurements of nitrogen dioxide (NO2) and nitrogen oxides (NOx). The Willems badge was validated for NO2 measurements both in laboratory tests and in field tests (Paper I-II). The sampling rate was 40.0 mL/min for ambient air concentrations and 46.0 mL/min for higher concentrations. No effects of different factors on sampling rate were found except for a reduced sampling rate at low wind velocity. The results of the laboratory validation were confirmed in field tests in ambient air and with personal sampling. The correlation between diffusive samplers and the reference monitor was good for ambient measurements. In conclusion, the Willems badge performs well at wind velocities down to 0.3 m/s, and this makes it suitable for personal sampling but less suitable for measurements in indoor air where the wind velocity is lower. Paper III reports about the field validation of the Ogawa diffusive samplers. Absolute humidity and temperature were found to have the strongest effect on sampling rate with lower uptake rates at low absolute humidity or temperature. The sampling rates above 0 °C were 8.6 mL/min for NO2 and 9.9 mL/min for NOx. NO2 and NOx concentrations that were determined using the manufacturer’s protocol were either underestimated or overestimated. The agreement between concentrations measured by the Ogawa sampler and the reference monitor was improved when field-determined sampling rates were used to calculate concentrations. Paper IV is based on a study with the aim of assessing the exposure of the Swedish general population to NO2 and some carcinogenic substances. The surveys were performed in one of five Swedish cities every year. In each survey, personal measurements of NO2 and some carcinogenic substances were conducted on 40 randomly selected individuals. In the study presented in this thesis, the NO2 part of the study is in focus and results were available for eight surveys conducted across the five cities. The estimated arithmetic mean concentration for the general Swedish population was 14.1 μg/m3. The exposure level for NO2 was higher for smokers compared with non-smokers, and the NO2 exposure levels were higher for people who had gas stoves at home or who were exposed at their workplace. The exposure was lower for those who had oil heating in their houses.
283

Evaluation of the Brainstem Spinal Cord Preparation in the Neonatal Rat as a Model for Prenatal Nicotine Exposure

Levine, Richard January 2012 (has links)
Class of 2012 Abstract / Specific Aims: The goal of this project was to evaluate the use of a preparation of the brainstem and spinal cord of neonatal rats that has been widely used for observing and quantifying central nervous activity, as well as the response to pharmacological manipulation. To achieve this, we specifically aimed to remove the intact brainstem and spinal cord of newborn rats, and develop a preparation that would maintain physiological function and allow for recording of electrical activity. Methods: Multiple dissections were performed on neonatal rats. Conditions during the dissections were controlled to maintain physiological function. Once removed, the intact brainstem and spinal cord was placed in a preparation that allowed for manipulation and access to nerve rootlets. Finally, glass suction electrodes were used to record electrical activity directly from the nerve rootlets. Once recorded, the data were stored on a hard drive for further analysis. Main Results: We were successful in isolating the intact brainstem and spinal cord in neonatal rats while maintaining physiological conditions and nervous activity. The preparation allowed for easy access to nerve roots as well as customization for different experiments. We were also successful in recording nerve activity in the preparation and collection of data for use in future experiments Conclusions: We conclude that the brainstem spinal cord preparation described in this study is a valuable tool that allows for recording and analysis of nerve activity, and specifically for measurement of respiratory motor output. This is a preparation that can be used in a variety of experiments that attempt to observe or quantify the activity of central nerve cells and allows for pharmacological interventions that could be applied in various experiments.
284

A study of haemoglobin : Egg laying, hatching, growth and summit metabolism.

Toivainen, Sanne January 2016 (has links)
Haemoglobin and its functions in various organisms is well known; it increases the ability to obtain precious oxygen and it is crucial in aerobic performance. However, if high values of haemoglobin are always beneficial, why is there a large natural variation? This study investigated the effects of varying concentrations of haemoglobin on several stages in the lifespan of Red Junglefowl: egg production and hatching, chicken growth, haemoglobin and summit metabolism. Red Junglefowl were tested for fertility in both eggs laid and eggs hatched. The offspring were individually measured for whole blood haemoglobin concentration and tested for growth and summit metabolism. The results show that there is a difference in haemoglobin after two weeks of age and that growth differs at the same time. High Hb animals do not lay smaller nor fewer eggs than low line birds but their offspring are smaller at the same time as there is a difference in haemoglobin levels. There was also a difference in the summit metabolism between the lines, where the high line animals performed better. Importantly the increase in haemoglobin did effect the growth of the animals negatively, and this would imply that higher levels of haemoglobin is not detrimental to growth.
285

Spatially Derived Risk Factors for Cutaneous Melanoma

Langston, Marvin Epolian, Langston, Marvin Epolian January 2016 (has links)
Intermittent sun exposure and sun sensitivity factors are the most well described risk factors for the development of cutaneous melanoma (CM). Other potential environmental risks for CM, such as arsenic, are rarely examined. Total sun exposure has not been a consistent risk factor for CM, but recall bias in self-reporting sun exposure throughout life may limit the ability to detect a true association. Objective measures of sun exposure including remotely sensed ambient ultra-violet radiation (UVR) may allow for better capture of total sun exposure. In three chapters, spatially derived factors (ambient UVR, environmental soil arsenic, drinking water arsenic) were observed to determine their relevance in exposure assessment and subsequent risk for CM.UVR trends were investigated using available satellite data (1978-2014) to generate inferences for UVB changes over time in the United States. We found that UVB changed across the study area, but these changes lack biological relevance based on the magnitude of changes observed. Thus, a more objective measure of lifetime ambient sun exposure may be estimated using 30-year average UVR by month in future studies. The spatial correlation between environmental soil arsenic and drinking water across the state of Iowa was investigated. Arsenic concentrations in soil were not significantly spatially correlated with either municipal public water source or non-municipal water source arsenic concentrations. Based on these findings, soil arsenic may not serve as a valid surrogate marker for arsenic in drinking water.In Chapter 5, we assessed the relationship of spatially derived estimates of lifetime ambient UVR, environmental arsenic exposure from soil and drinking water, and CM in a population-based case-control study. Our findings suggest that total sun exposure is positively associated with CM, while arsenic concentration in environmental soil and drinking water were not associated. Sun exposure measured through ambient UVR exposure may allow for better understanding of the association between cumulative or total sun exposure and CM. Additionally, more studies need to be completed to estimate the potential risks for CM in regions where high arsenic concentrations may not be endemic.
286

Thermal Exposure Caused by the Smoke Gas Layer in Pre-flashover Fires : A Two-zone Model Approach

Andersson, Lucas January 2016 (has links)
A pre-flashover fire is very different from a post-flashover fire. The main difference is that in a pre-flashover fire the gas temperature and the radiation temperature differ. One thing that makes it a lot different is that the thermal exposure induced by a pre-flashover fire is largely affected by the smoke gas layer. These smoke gases can be very hot and therefore they emit heat radiation to their surroundings. The theory used, to calculate the thermal exposure of a pre-flashover fire, in this thesis relies on using thermal resistances to describe the heat transfer from the smoke gases. By doing so it is possible to calculate the temperatures of the smoke gases and the surfaces in touch with the smoke gases. Another approach is to use CFD software to numerically calculate the temperatures and in this thesis the two-zone model are compared to FDS, a CFD software. The two-zone model are also compared to a reduced-scale test. The comparisons gave good results, the two-zone model produced similar results compared to re reduced-scale test and FDS. This method of calculating thermal exposure can thereby be used to evaluate evacuation safety and save a lot of calculation time compared to calculating the thermal exposure with CFD software such as FDS.
287

Relations between Violence Exposure, Threat Appraisal, and Coping among Typologies of Victimized Adolescents

Taylor, Katherine 19 April 2011 (has links)
According to the transactional theory of stress and coping, threat appraisals influence coping and adjustment. Previous research has shown that threat appraisals mediate relations between violence exposure and adjustment, but few studies have examined links between threat appraisals and coping. The current study examined relations between violence exposure, threat appraisals, and coping among typologies of victimized adolescents. The sample included 159 predominately African American adolescents (M = 12.1). Path analyses were used to test whether threats of negative evaluation by self and others mediated relations between violence exposure and avoidance and positive reframing coping, respectively. Results did not indicate mediation or differential relations between study constructs for victim typologies. Significant direct effects were found between violence exposure and negative self-evaluation and positive reframing, such that greater violence exposure was associated with a greater likelihood of self-blaming and positive reframing. These findings have implications for youth violence prevention and intervention efforts.
288

Tailoring Local Conductivity by the Formation of Ag Nanoclusters in SiO2 Xerogel Films

Caperton, Ricky 01 January 2009 (has links)
Porous silicon dioxide thin films were produced via dip-coating and doped with Ag+ by adding AgNO3 to the dipping solution. Nanoparticles were formed within the pores of these films by UV exposure. Nanoparticle formation was confirmed by UV-visible spectroscopy and Transmission Electron Microscopy (TEM). Conductive Atomic Force Microscopy (CAFM) showed that the conductivity of the films decreased upon exposure to UV. This decrease in the conductivity is most likely due to the clustering of charge carriers. Initially, Ag+ ions are attached to negatively charged pore walls in a dense packing network. Upon UV exposure (125 mW @ 266 nm), the Ag+ ions are reduced to Ag metal and agglomerate to form clusters. The agglomeration creates gaps in the film that decrease its conductivity. This ability to tune film conductivity was used to create insulating patterns within conducting films. A calibration mask was placed over the films during UV exposure, and exposed regions with a minimum width of ~2 μm were detected as depressions with insulating behavior. The fabrication of photonic and plasmonic devices is being explored using this method.
289

Pravdivost ve smyslu pohlížení a vystavenosti / Truthness in Terms of Gazing and Exposure

Jahoda, Lukáš January 2016 (has links)
The meaning of this work is an explanation of Heideggers notion of the truth from the early fundamental ontology, demonstration of its limits and the interpretation of its intensification in the concept of the truth from the texts Vom Wessen der Wahrheit and Platons lehre von der Wahrheit. The explanation of the truth of being from the fundamental ontology is primarely lead by the regard on the distinction between handy being and the being that just occurs and their respective modifications of understanding: handling and gazing. The explanation of Heideggers notion of the truth from the early thirties should refer to deeper level of research, where the basic distinction of being and understanding not yet appears. On this deeper degree finds Heidegger the notion of the truth as the exposure to the being in the openness of relating. This conception of the truth should be introduced as an avoidance of the problematic dualism in the fundamental ontology and as a deeper point of view, in which the truth is not derived from the understanding of existence, but from the ek-sistential exposure to the being, which let itself to be led by it.
290

Compassion fatigue, level of exposure, empathy and affect intensity amongst employee assistance programme counsellor

Harinarain, Eshmin 16 May 2008 (has links)
ABSTRACT High levels of trauma within the South African society affect the majority of the population either directly or indirectly. In order to assist individuals overcome such traumatic incidents, many companies in South Africa have contracted with Employee Assistance Programme (EAP) Providers to provide counselling to employees. These EAP counsellors are often the first mental health professionals to be exposed to a client’s traumatic story. Consequently, such counsellors may be vulnerable to compassion fatigue (CF). The consequences of EAP counsellors working with traumatised clients have been relatively unexplored. Therefore, this study proposed that EAP trauma counsellors are vulnerable within their scope of work and are an important group of professionals to be further investigated. Furthermore, leading authors in the field of trauma argue that both individual characteristics and environmental factors play a role in the development of CF. However, research into the process by which CF develops is extremely limited. Hence, this study attempted to explore this process through identifying possible core variables such as level of exposure, empathy and affect intensity and exploring their link to CF. The study was based on Figley’s (1995) Trauma Transmission Model, Dutton and Rubinstein’s (1995) Ecological Model and McRitchie’s (2006) Refined Model for Trauma Workers. The data was collected from 60 EAP counsellors, through self report measures. Data was analysed using descriptive statistics, correlations, a stepwise regression, two independent sample t-tests, and analysis of variance. Results revealed that 28.34% of the sample fell within the range for CF. There were significant correlations between Level of Exposure to traumatic material and CF; between levels of empathy and CF and between Affect Intensity and Empathy. There was no significant correlation between Affect Intensity and CF. Furthermore, the stepwise regression indicated that 56% of CF may be explained by a combination of four interacting variables, that is, Level of Exposure, Fantasy, Personal Distress and Perspective Taking.

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