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1
Zioga, Georgia. "Studies on the reaction of pyrrolobenzodiazepines with nucleophiles." Thesis, University of Portsmouth, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.298374.
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Narayanaswamy, Mathangi. "An Assay combining HPLC and MS to Evaluate the DNA-Interaction of Pyrrolobenzodiazepines (PBDs) with Oligonucleotides." Thesis, University College London (University of London), 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.509315.
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Nandigam, Harika. "Capability of the Tumor Microenvironment to Attract a Precursor of B-cells and Dendritic Cells from Bone Marrow." Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1307108043.
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Söderström, Gunilla. "On the combustion and photolytic degradation products of some brominated flame retardants." Doctoral thesis, Umeå University, Chemistry, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-107.
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Many modern products, especially electronic goods, are protected by brominated flame retardants (BFR). Some of the most common flame retardants are polybrominated diphenylethers (PBDE), tetrabromobisphenol-A (TBBP-A) and hexabromocyclododecane (HBCD). These compounds have been found in environmental samples and shown to have physiological effects on experimental animals. This thesis considers end-of-life aspects of brominated flame retardants. When spread in the environment, these compounds may be degraded into other forms. For example, if sludge contaminated with PBDE is used as an agricultural fertilizer, the PBDE could be degraded by sunlight to species of PBDE with lower degree of bromination and, to some extent, also form polybrominated dibenzofurans (PBDF). In addition, PBDF and polybrominated dibenzo-p-dioxins (PBDD) are formed during combustion of brominated flame retardants. When waste products with brominated flame retardants are co-combusted with household waste or other chlorinated fuel, polybrominated- chlorinated dibenzo-p-dioxins (PBCDD) and polybrominated- chlorinated dibenzofurans (PBCDF)will be formed. The bromin/chlorine composition of dioxins and furans is dependent on the bromine/chlorine ratio in the fuel, but the types of brominated flame retardants that are being combusted is less important. In the studies reported here, bromine levels higher than "normal" for household waste has been used. The results show that there is a pronounced increase in total dioxin levels in fluegas when when bromine is present, implying that waste containing brominated flame retardants should only be incinerated at combustion plants with effecient air pollution control devices.
5
Maxwell, Megan Amanda, and n/a. "PEX1 Mutations in Australasian Patients with Disorders of Peroxisome Biogenesis." Griffith University. School of Biomolecular and Biomedical Science, 2004. http://www4.gu.edu.au:8080/adt-root/public/adt-QGU20040219.100649.
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The peroxisome is a subcellular organelle that carries out a diverse range of metabolic functions, including the b-oxidation of very long chain fatty acids, the breakdown of peroxide and the a-oxidation of fatty acids. Disruption of peroxisome metabolic functions leads to severe disease in humans. These diseases can be broadly grouped into two categories: those in which a single enzyme is defective, and those known as the peroxisome biogenesis disorders (PBDs), which result from a generalised failure to import peroxisomal matrix proteins (and consequently result in disruption of multiple metabolic pathways). The PBDs result from mutations in PEX genes, which encode protein products called peroxins, required for the normal biogenesis of the peroxisome. PEX1 encodes an AAA ATPase that is essential for peroxisome biogenesis, and mutations in PEX1 are the most common cause of PBDs worldwide. This study focused on the identification of mutations in PEX1 in an Australasian cohort of PBD patients, and the impact of these mutations on PEX1 function. As a result of the studies presented in this thesis, twelve mutations in PEX1 were identified in the Australasian cohort of patients. The identified mutations can be broadly grouped into three categories: missense mutations, mutations directly introducing a premature termination codon (PTC) and mutations that interrupt the reading frame of PEX1. The missense mutations that were identified were R798G, G843D, I989T and R998Q; all of these mutations affect amino acid residues located in the AAA domains of the PEX1 protein. Two mutations that directly introduce PTCs into the PEX1 transcript (R790X and R998X), and four frameshift mutations (A302fs, I370fs, I700fs and S797fs) were identified. There was also one mutation found in an intronic region (IVS22-19A>G) that is presumed to affect splicing of the PEX1 mRNA. Three of these mutations, G843D, I700fs and G973fs, were found at high frequency in this patient cohort. At the commencement of these studies, it was hypothesised that missense mutations would result in attenuation of PEX1 function, but mutations that introduced PTCs, either directly or indirectly, would have a deleterious effect on PEX1 function. Mutations introducing PTCs are thought to cause mRNA to be degraded by the nonsense-mediated decay of mRNA (NMD) pathway, and thus result in a decrease in PEX1 protein levels. The studies on the cellular impact of the identified PEX1 mutations were consistent with these hypotheses. Missense mutations were found to reduce peroxisomal protein import and PEX1 protein levels, but a residual level of function remained. PTC-generating mutations were found to have a major impact on PEX1 function, with PEX1 mRNA and protein levels being drastically reduced, and peroxisomal protein import capability abolished. Patients with two missense mutations showed the least impact on PEX1 function, patients with two PTC-generating mutations had a severe defect in PEX1 function, and patients carrying a combination of a missense mutation and a PTC-generating mutation showed levels of PEX1 function that were intermediate between these extremes. Thus, a correlation between PEX1 genotype and phenotype was defined for the Australasian cohort of patients investigated in these studies. For a number of patients, mutations in the coding sequence of one PEX1 allele could not be identified. Analysis of the 5' UTR of this gene was therefore pursued for potential novel mutations. The initial analyses demonstrated that the 5' end of PEX1 extended further than previously reported. Two co-segregating polymorphisms were also identified, termed 137 T>C and 53C>G. The -137T>C polymorphism resided in an upstream, in-frame ATG (termed ATG1), and the possibility that the additional sequence represented PEX1 coding sequence was examined. While both ATGs were found to be functional by virtue of in vitro and in vivo expression investigations, Western blot analysis of the PEX1 protein in patient and control cell extracts indicated that physiological translation of PEX1 was from the second ATG only. Using a luciferase reporter approach, the additional sequence was found to exhibit promoter activity. When examined alone the -137T>C polymorphism exerted a detrimental effect on PEX1 promoter activity, reducing activity to half that of wild-type levels, and the -53C>G polymorphism increased PEX1 promoter activity by 25%. When co-expressed (mimicking the physiological condition) these polymorphisms compensated for each other to bring PEX1 promoter activity to near wild-type levels. The PEX1 mutations identified in this study have been utilised by collaborators at the National Referral Laboratory for Lysosomal, Peroxisomal and Related Genetic Disorders (based at the Women's and Children's Hospital, Adelaide), in prenatal diagnosis of the PBDs. In addition, the identification of three common mutations in Australasian PBD patients has led to the implementation of screening for these mutations in newly referred patients, often enabling a precise diagnosis of a PBD to be made. Finally, the strong correlation between genotype and phenotype for the patient cohort investigated as part of these studies has generated a basis for the assessment of newly identified mutations in PEX1.
6
Maxwell, Megan Amanda. "PEX1 Mutations in Australasian Patients with Disorders of Peroxisome Biogenesis." Thesis, Griffith University, 2004. http://hdl.handle.net/10072/366184.
Full textAbstract:
The peroxisome is a subcellular organelle that carries out a diverse range of metabolic functions, including the b-oxidation of very long chain fatty acids, the breakdown of peroxide and the a-oxidation of fatty acids. Disruption of peroxisome metabolic functions leads to severe disease in humans. These diseases can be broadly grouped into two categories: those in which a single enzyme is defective, and those known as the peroxisome biogenesis disorders (PBDs), which result from a generalised failure to import peroxisomal matrix proteins (and consequently result in disruption of multiple metabolic pathways). The PBDs result from mutations in PEX genes, which encode protein products called peroxins, required for the normal biogenesis of the peroxisome. PEX1 encodes an AAA ATPase that is essential for peroxisome biogenesis, and mutations in PEX1 are the most common cause of PBDs worldwide. This study focused on the identification of mutations in PEX1 in an Australasian cohort of PBD patients, and the impact of these mutations on PEX1 function. As a result of the studies presented in this thesis, twelve mutations in PEX1 were identified in the Australasian cohort of patients. The identified mutations can be broadly grouped into three categories: missense mutations, mutations directly introducing a premature termination codon (PTC) and mutations that interrupt the reading frame of PEX1. The missense mutations that were identified were R798G, G843D, I989T and R998Q; all of these mutations affect amino acid residues located in the AAA domains of the PEX1 protein. Two mutations that directly introduce PTCs into the PEX1 transcript (R790X and R998X), and four frameshift mutations (A302fs, I370fs, I700fs and S797fs) were identified. There was also one mutation found in an intronic region (IVS22-19A>G) that is presumed to affect splicing of the PEX1 mRNA. Three of these mutations, G843D, I700fs and G973fs, were found at high frequency in this patient cohort. At the commencement of these studies, it was hypothesised that missense mutations would result in attenuation of PEX1 function, but mutations that introduced PTCs, either directly or indirectly, would have a deleterious effect on PEX1 function. Mutations introducing PTCs are thought to cause mRNA to be degraded by the nonsense-mediated decay of mRNA (NMD) pathway, and thus result in a decrease in PEX1 protein levels. The studies on the cellular impact of the identified PEX1 mutations were consistent with these hypotheses. Missense mutations were found to reduce peroxisomal protein import and PEX1 protein levels, but a residual level of function remained. PTC-generating mutations were found to have a major impact on PEX1 function, with PEX1 mRNA and protein levels being drastically reduced, and peroxisomal protein import capability abolished. Patients with two missense mutations showed the least impact on PEX1 function, patients with two PTC-generating mutations had a severe defect in PEX1 function, and patients carrying a combination of a missense mutation and a PTC-generating mutation showed levels of PEX1 function that were intermediate between these extremes. Thus, a correlation between PEX1 genotype and phenotype was defined for the Australasian cohort of patients investigated in these studies. For a number of patients, mutations in the coding sequence of one PEX1 allele could not be identified. Analysis of the 5' UTR of this gene was therefore pursued for potential novel mutations. The initial analyses demonstrated that the 5' end of PEX1 extended further than previously reported. Two co-segregating polymorphisms were also identified, termed –137 T>C and –53C>G. The -137T>C polymorphism resided in an upstream, in-frame ATG (termed ATG1), and the possibility that the additional sequence represented PEX1 coding sequence was examined. While both ATGs were found to be functional by virtue of in vitro and in vivo expression investigations, Western blot analysis of the PEX1 protein in patient and control cell extracts indicated that physiological translation of PEX1 was from the second ATG only. Using a luciferase reporter approach, the additional sequence was found to exhibit promoter activity. When examined alone the -137T>C polymorphism exerted a detrimental effect on PEX1 promoter activity, reducing activity to half that of wild-type levels, and the -53C>G polymorphism increased PEX1 promoter activity by 25%. When co-expressed (mimicking the physiological condition) these polymorphisms compensated for each other to bring PEX1 promoter activity to near wild-type levels. The PEX1 mutations identified in this study have been utilised by collaborators at the National Referral Laboratory for Lysosomal, Peroxisomal and Related Genetic Disorders (based at the Women's and Children's Hospital, Adelaide), in prenatal diagnosis of the PBDs. In addition, the identification of three common mutations in Australasian PBD patients has led to the implementation of screening for these mutations in newly referred patients, often enabling a precise diagnosis of a PBD to be made. Finally, the strong correlation between genotype and phenotype for the patient cohort investigated as part of these studies has generated a basis for the assessment of newly identified mutations in PEX1.Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Biomolecular and Biomedical Sciences
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Löfstrand, Karin. "Trends and exposure of naturally produced brominated substances in Baltic biota - with focus on OH-PBDEs, MeO-PBDEs and PBDDs." Doctoral thesis, Stockholms universitet, Institutionen för material- och miljökemi (MMK), 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-54421.
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The semi-enclosed and brackish Baltic Sea has become heavily polluted by nutrients, anthropogenic organic and inorganic chemicals via human activities. Persistent organic pollutants (POPs) have been thoroughly investigated due to their linkage to toxic effects observed in Baltic biota. There has been far less focus on semi-persistent pollutants e.g. naturally produced oraganohalogen compounds (NOCs) and their disturbances in the environment. This thesis is aimed on assessment of levels and trends of naturally produced brominated compounds in Baltic biota; more specifically on hydroxylated polybrominated diphenyl ethers (OH-PBDEs), methoxylated PBDEs (MeO-PBDEs) and polybrominated dibenzo-p-dioxins (PBDDs). These, NOCs, may originate from production in algae and cyanobacteria. OH-PBDEs and MeO-PBDEs may also be formed as metabolites of polybrominated diphenyl ethers (PBDEs), i.e. well-known commercial flame retardants. High levels of OH-PBDEs, MeO-PBDEs and PBDDs are shown within Baltic biota (cyanobacteria, algae, mussels, fish), often in much higher concentrations than PBDEs which are possible anthropogenic precursors of OH- and MeO-PBDEs. The levels of OH-PBDEs, MeO-PBDEs and PBDDs are higher in the Baltic Sea than on the west coast of Sweden. Temporal and seasonal variations show fluctuations in concentrations of OH-PBDEs, MeO-PBDEs and PBDDs, possibly related with macroalgal life-cycles. OH-PBDEs, MeO-PBDEs and PBDDs are present in several filamentous macroalgae species, but considering the levels quantified, the time of peak exposure and the species life-cycle the macroalgae, Pilayella, Ceramium and Cladophora are suggested as major natural producers of OH-PBDEs and PBDDs. The high levels of OH-PBDEs, MeO-PBDEs and PBDDs in the Baltic Sea may affect numerous organisms in the ecosystem. The toxic effects of OH-PBDEs and PBDDs are of particular concern. This thesis stress the importance of assessing and monitoring these substances, since the exposure to OH-PBDEs and PBDDs, during summer, may cause acute effects in Baltic fish and wildlife.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: In press. Paper 4: Manuscript.
8
Ortuño, García Nuria. "Descomposición térmica de residuos de aparatos eléctricos y electrónicos: estudio cinético y formación de contaminantes." Doctoral thesis, Universidad de Alicante, 2014. http://hdl.handle.net/10045/41605.
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Hroch, Martin. "Studium distribuce halogenovaných difenyletherů do složek životního prostředí." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2012. http://www.nusl.cz/ntk/nusl-233346.
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In recent years considerable attention is paid to problems of brominated flame retardants (BFR's – Brominated Flame retardants), which are a diverse group of organic compounds. Even in the recent past have been the most often represented group particularly polybrominated diphenyl ethers (PBDEs), which have found wide use in many industrial sectors. The reason of aplication of these substances is the ability to slow down the combustion process and reduce the risk of ignition by the excessive heating of material. On the other hand, serious concerns about the use of PBDEs was added. The most serious trouble is particular their possible to release from consumer products during their normal use, toxicity and high persistence in parts of environment. Some of these contaminants are more characterized by a high degree of accumulation in biological systems. In this work by several sub-studies the issue of assessment the level of pollution of the aquatic ecosystem of selected localities of the Czech Republic just PBDEs was addressed. One of objectives was monitored the situation of breeding ponds near the village Záhlinice in Central Moravia. Here was assessed level of contamination in fish and birds as two consecutive segments of food chain. The obtained results largely confirmed the assumption that with increasing trophic level of organisms leads to bioaccumulation and thus also higher findings. For comparison, the capture of fish and birds in other localities of the CR was also implemented. In Bartošovice and Hustopeče nad Becvou levels at the buzzard and heron were detected as comparable. The cormorants of the order higher levels of PBDEs were found. Further were also evaluated levels of PBDEs detected in individuals of bioindicator kind of chub caught in two locations on the river Svratka in spring and autumn. Findings of PBDE in muscle, skin and intestines were compared. The obtained results show that between tissues and sites wasn’t significant variability respectively and the findings of controlled substances are practically comparable. With aim to determine the dependence of the concentration of PBDEs in organisms on the length of the river was conducted monitoring of Vír and Brno water reservoirs. In both locations was main monitored kind of bream, which was completed by the other species. The results of the analysis indicate a higher total concentration at the lower part of river Svratka. Differences were also the distribution of individual congeners in both sampling locations. For monitoring of terrestrial system contamination levels of PBDEs has been selected several types of plant bioindicators. These are mainly pine needles (Scots pine, Eastern white pine, Silver fir, Blue spruce) collected from different localities of the Czech Republic. Other matrices were chosen roughages (Common wheat, Naked barley, Alfalfa wheat, Red clover) and oilseeds (Rapeseed) from the Novy Jicin, where Agriculture plant school of the University of Veterinary and Pharmaceutical Sciences Brno. Detected values of PBDE concentrations were very low, generally ranged at the detection limits of the analytical method.
10
Khan, Simeen. "Colloidal PbS and PbS/CdS Core/Shell Nanosheets." Bowling Green State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1447955111.
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Vondráčková, Ilona. "Zhodnocení obsahu PCB a PBDE v rostlinných bioindikátorech." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2009. http://www.nusl.cz/ntk/nusl-216534.
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In the assessment of the environment pollution level, bio indicators of vegetable or animal origin are often used. Bio indicators include also needles and moss. The samples of moss and needles taken in different locations in the Czech Republic were examined to find out the presence of xenobiotics of polychlorine biphenyls and polybromide diphenylethers types. Selected analytes have been extracted from the matrix by hexan. Extracts have been refined using column chromatography on mixed florisil/silicagel sorbent. To analysis of selected compounds, GC/ECD method has been chosen. Based on our results a comparison of the contamination level in individual locations was enabled.
12
Crosse, John D. "PBDEs in predatory birds from the UK." Thesis, Lancaster University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.658319.
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polybrominated diphenyl ethers (PBDEs) are additive flame retardants that have been -widely used globally for the last 30-40 years. In their functional operation, PBDEs are released from parent products when exposed to heat and light in order to retard combustion reactions. The physiochemical properties of PBDEs coupled with widespread use and production has led to ubiquitous environmental contamination by these compounds. In recent years PBDEs have become increasingly well studied and evidence of their toxicity to biota and occurrence in remote and pristine environments has led to the - implementation of legislation to control their use and production. A great many studies have been published on PBDEs, and key concepts are introduced in Chapter 1. However, comparatively little data exists for the UK. Data is lacking on both marine and terrestrial birds of prey; this is disconcerting, given the potential toxicity of PBDEs, as predatory birds have been susceptible to the adverse effects of anthropogenic organic contaminants in the past. Utilising the eggs and livers of two predatory bird sentinel species, the northern gannet (Morus bassanus) and the sparrowhawk (Accipiter nisus), collected as pati of the activities of the Predatory Bird Monitoring Scheme (PBMS), this work aimed to detennine detailed long-term temporal and spatial trends of PBDEs in UK marine and terrestrial systems. In addition, stable isotope residues of carbon and nitrogen were used to identify if changes in the diets of these birds could influence the trends in contaminant residues in their eggs. Furthermore, other potentially confounding factors such as age, sex and body condition were assessed using sparrowhawk livers - a matrix which allowed for the PBDE contamination in male sparrowhawks to be characterised. The findings of the studies conducted as part of this thesis are presented in Papers IIV and discussed collectively in Chapter 2. Methodologies are provided in Papers I-IV and supplemented by Appendix 2. Other POPs, for which data is presented in Paper 4, are discussed in Chapter 1 and Appendix 3. Contributions to relevant studies regarding PBDE toxicity and trends in UK air are presented in Appendices 4 and 5. Key conclusions and recommendations for further work are given in Chapters 3 and 4.
13
Sasaki-Skopp, Amanda. "Development of a Culturally Responsive PBIS Toolkit." Thesis, University of Oregon, 2018. http://hdl.handle.net/1794/23097.
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The purpose of this grant proposal is to develop a toolkit to support school teams in the development and implementation of culturally responsive Positive Behavioral Interventions and Supports (PBIS). The toolkit is necessary to help school teams address lingering disparities in discipline and to improve school climate. Exclusionary discipline, such as out of school suspensions and expulsion, disproportionately affects ethnically and racially diverse students, and has a devastating effect on student outcomes, including academic achievement, attendance, and graduation. Ethnically and racially diverse students are also more likely to be given a disciplinary consequence for behaviors that require a subjective interpretation of the student’s behavior, which can be influenced by implicit bias. In schools that have implemented PBIS, exclusionary discipline has been shown to decrease overall, but disproportionate discipline persists. The development of a culturally responsive toolkit will support the efforts of school PBIS teams to decrease disproportionate discipline outcomes. The toolkit will assist school teams with the cultural adaptation of core features of PBIS by providing a process for addressing contextual fit of the school and soliciting feedback from the school community.
The methodological approach for this project includes both qualitative and quantitative processes. An expert panel will be convened to address the complexities of implementation and cultural adaptation within the context of PBIS. The culturally responsive PBIS toolkit will consist of a comprehensive series of recommended practices, contextual considerations, evaluation tools, and resources, to be used concurrently with analysis of schoolwide data. The toolkit will be piloted in schools in the Pacific Northwest and then disseminated.
14
Khan, Anastassiya. "Synthesis and characterization of defective PBAs electrode material." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21015/.
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Sodium manganese hexacyanoferrate (NaMnHCF) and its derivatives have been synthesized by simple co-precipitation method with addition of the citric and ascorbic acids respectively. The correspondent crystal structure, water content, chemical formula and a deep structural investigation of prepared samples have been performed by means of the combination of the laboratory and synchrotron techniques (PXRD, FT-IR, TGA, MP-AES and XAS). Electrochemical tests have been done using three-electrode system in sodium nitrate solution at different concentration. From cyclic voltammetry curves, Fe3+/2+ redox peak has been observed, whereas Mn3+/2+ peak was not always evident. Structural stability of the cycled samples has then been tested using 2D XRF imaging and Transmission X-ray microscopy (TXM) techniques. The intercalation of NaMnHCF after 20 cycles has been found by micro-XANES analysis of the highlighted spots which have been found in the XRF images. TXM has also confirmed the appearance of the intercalated particles after 50 cycles comparing the spectra between charged and discharged materials at three different edges (Mn, Fe and N). However, by comparison with lithium samples, it seems obvious that sodium samples are more homogeneous and intercalation is at the very beginning indicating the relative structural stability of sodium manganese hexacyanoferrate electrode material.
15
Bakari, Heather. "Evaluation of an Elementary PBIS Bully Prevention Program." TopSCHOLAR®, 2014. http://digitalcommons.wku.edu/theses/1329.
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School bullying has become an international source of concern. The media has captured the attention of the public with coverage of incidents such as the Columbine massacre. On April 20, 1999, Eric Harris and Dylan Klebold walked through their school, shooting particular students they found. One victim asked why they were doing it. They said it was a dream come true and “payback” for being ostracized by their peers (Kalish & Kimmel, 2010). Until such devastations acted out in schools, bullying was considered a rite of passage. For the most part, parents and faculty did little to prevent it. In recent years psychological research studies have confirmed that bullying can be detrimental to the emotional, physical, and mental health of developing adolescents. This program evaluation was completed to determine whether or not the Positive Behavior Interventions and Supports bully prevention intervention implemented at an elementary school in Kentucky was effective by creating a more positive school climate, increasing the amount of bystander participation during bullying incidents and decreasing the number of times students felt they had been treated disrespectfully. Analyses indicated the intervention was unsuccessful. Student ratings were very positive prior to the implementation of the intervention and were similarly positive after the intervention that been implemented. Data provided by the school indicated there was not a bullying problem within the school prior to implementing the intervention.
16
Moreira, Bastos Patricia. "Comparison of experimentally and theoretically determined oxidation and photochemical transformation rates of some organohalogens to promote prediction of persistence." Doctoral thesis, Stockholms universitet, Institutionen för miljökemi, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-26040.
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The diversity of choices we have to make everyday influence our environment and ourselves in more ways than most of us realise. Anthropogenic substances, such as flame retardants, date back as early as 450 BC when the Egyptians used alum to reduce flammability. The increasing demand for new articles has led to an increased production of chemical substances, for which many are commercially produced without complete knowledge on properties such as persistence, bioaccumulation and toxicology (PBT). Commercial compounds may be properly tested and denominated as “safe” regarding PBT properties, but their degradation products and/or metabolites may cause environmental impact. The availability of uniform and accurate data for prediction of persistence is of key importance for the understanding of chemical fate. A method to determine the susceptibility of chemicals to undergo oxidation in water has been developed and applied on several organohalogens, including PBDEs and OH-PBDEs. The method was used to determine reaction rates and the group of OH-PBDEs were subsequently subjected to photolysis by use of UV-light. Hence, susceptibility to undergo both oxidation and photolysis for the OH-PBDEs were investigated and compared to previously reported degradation rates on PBDEs. As a final step in promoting the prediction of persistence, Quantitative structure-property relationship (QSPR) models were performed on a set of compounds which had undergone photolytic degradation under similar conditions. The QSPRs were used as a preliminary step in predicting photolysis half-lives for chemical substances and to determine which physicochemical descriptors are of greatest importance thereof. This thesis presents the possibility of performing and assessing oxidation transformations on compounds of low and high water solubility, photolysis transformations in various media and using obtained data to predict behaviour via QSPR models, to promote predictions of persistence.
17
Phillips, Terrie Davis. "Teacher Assessments of Positive Behavior Support in School." ScholarWorks, 2014. https://scholarworks.waldenu.edu/dissertations/24.
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Students are often removed from classrooms due to behavioral concerns, which has led to an increase in student drop-out rates. Positive behavior support (PBS), a proactive approach to student discipline, was implemented at a local school in order to address the influx of students being sent to the office. Constructivism was the framework for this mixed method study on teachers' assessments of the current behavior support approach in their school and teachers' perceptions of school-wide PBS training and implementation. Data from the Effective Behavior Support (EBS) Survey were used in a descriptive statistical analysis of 162 teachers' assessments of behavior support. Interview data, including transcripts from 15 semi-structured teacher interviews, were analyzed using open coding and thematic analysis. The EBS survey results indicated that teachers desired more assistance with PBS through strategies, recommendations, and district support. Interview data indicated a need for a staff development project to assist instructors with understanding the systematic process of PBS through the use of the Response to Intervention model and to gain access to district support staff as behaviors increased in the classroom. The resulting project was a 3-day teacher training to address this need. This study has the potential to evoke positive social change through developing best practices across districts and providing staff with the tools for positive behavior support in the learning community to decrease the dropout rate.
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Sundvall, Börje, and Linda Johansson. "Metodutveckling för analys av PBDE och HBCD i sediment." Thesis, Halmstad University, School of Business and Engineering (SET), 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-870.
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Brominated flame retardants (BFRs) has for many years been used in products to reduce their
flammability, mainly in electronic products, textiles and construction materials.
In 2003, Sweden imported 300 tons of brominated flame retardants.
Leakage of these compounds has polluted natural environments. Fishes has shown increased
contents of these substances, especially fat fish, since brominated flame retardants tends to
accumulate in fatty tissues.
They are also regarded as persistent and that gives them the ability to travel long distances.
What also is really scary is that increased levels of brominated flame retardants have been
detected in human breast milk.
The knowledge of the brominated flame retardants is limited and not so much research has been
done in this field. There are many reasons though, to keep the research going. Partly their
structural resemblance to well-known toxics as PCB, but also their ability to accumulate in
biological systems and enrich in food chains.
In which way they affect humans we really don’t know yet. Experiments on mice have been done
and behavioural disturbances were observed as well as a decrease in learning capacity.
The BRFs chosen for this study are hexabromocyclododecan (HBCD) and a polybrominated
diphenyl ether (PBDE) called pentabromodiphenylether (BDE 99).
About 25 % of the flame retardants produced in the world every year, consists of the brominated
ones. If we look at the PBDEs it’s mainly tetrabromodiphenylether (BDE 47),
pentabromodiphenylether (BDE 99), octabromodiphenylether (BDE 205) and
decabromodiphenylether (BDE 209) that are common flame retardants.
As from July 1st 2006, PBDE was forbidden in electric and electronic products (15).
January 1st 2007, a Swedish prohibition concerning the use of BDE-209 was established. BDE-
209 is not allowed on the Swedish market if the content of substance exceed 0,1 percent of weight
(23).
BDE-99 is classified as environmentally dangerous and a healthrisk. It´s not only toxic for
waterliving organisms but also for humans if exposed during a long time (19).
We shall develop a well functioning, reproducible and economic method to analyse HBCD and
PBDE in sediment. It includes extraction, cleanup and sample analyses with a ECD (electron
capture detector) equipped capillary gas chromatograph.
Several analyses of adequate diluted standards has been analysed in a GC-ECD to find suitable
temperature gradients. Then we produced spiked sediment samples with known amounts of
standards. To homogenize the spiked samples we used a mixer. As a first step in the extraction we
used acetone as a solvent. Then we used cyclohexane and NaCl (2%) to separate the nonpolar and
polar substances from each other. Cleanup with concentrated sulphuric acid was done and for
some samples we also used Florisil. To concentrate the extract it was evaporated with N2(g).The
extract was then analysed in a GC-ECD and then the results was compared with the standards.
The result of this project showed that our method of extraction is useful. We managed to extract
50 % HBCD, 30 % BDE-99 and 60 % BDE-99 (dried sediment).
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Muenhor, Dudsadee. "Polybrominated diphenyl ethers (PBDEs) in indoor and outdoor environments." Thesis, University of Birmingham, 2011. http://etheses.bham.ac.uk//id/eprint/2854/.
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PBDEs were detected in all air and dust samples. The PBDE congener profile in both outdoor and indoor air samples from Thai e-waste storage facilities and homes was dominated by BDE-47 and 99, whilst the predominant BFRs in all dust samples from Thai e-waste storage facilities were BDE-209, BDE-208, BDE-207, BDE-206, BDE-197, BDE-183, BDE-99, BDE-47 and DBDPE. Furthermore, BDEs 99 and 47 were the most abundant congeners in all dust samples from Thai houses and cars and UK homes. Under realistic high-end scenarios of occupational exposure to BDE-99 via dust ingestion, workers in Thai e-waste storage facilities were exposed above a recently-published Health Based Limit Value for this congener. For non-occupational exposure, under a high-end exposure scenario, the exposure to BDE-99 of such Thai children via dust ingestion is either very close to or in exceedance of the HBLV. PBDE levels in most of the areas monitored within the same rooms were not statistically significantly different. Similarly, concentrations of PBDEs in the majority of rooms within the same houses were not statistically significantly different between rooms. Possible dilution of PBDE levels in dust with increasing dust loadings has been identified in a small number of rooms.
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Vondráčková, Ilona. "Studium průniku PBDE a perfluorovaných sloučenin do vodních ekosystémů." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2015. http://www.nusl.cz/ntk/nusl-233409.
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In the presented PhD. thesis, problems covering occurrence of polybrominated diphenyl ethers (PBDE) and perfluorinated compounds in the environment were solved. The study was focused on identification and further verification of optimal methods in order to determine PBDEs and perfluorinated compounds sampled from the aquatic ecosystem. Polybrominated diphenyl ethers belong to persistent compounds classified as main pollutants; within the environmental constituents, they have been observed particularly in the last decade. For these studies, there were selected surface water matrices and sediments taken in various localities within the river Svratka basin. The analyses were to demonstrate whether they accumulate and remain in these specific matrices for longer time. There we assessed the congeners of polybrominated diphenyl ethers as follows: BDE-28, 47, 66, 85, 99, 100, 153, 154 and 183. In order to isolate them from matrices, various extraction techniques were used, i.e., ultrasonic extraction, microwave extraction, and pressure solvent extraction. Gas chromatography method with electron capture detection (GC/ECD) was selected for determination. The accomplished studies also assessed basic chemical, physical and environmental characteristics of diphenyl ethers in the environmental constituents. The attention was also paid to perfluorooctanoic compounds (PFOA), (PFOS) and (FOSA); physico-chemical properties of these organic pollutants were characterised and their toxicological and environmental aspects were evaluated. Usability of extraction techniques (ultrasonic extraction, pressure solvent extraction, solid phase extraction) applied to PFCs isolation from sediments samples was assessed. Identification and quantification of these analytes were performed using a high performance liquid chromatography/mass spectrometry method (HPLC/MS). After that, the optimized methods applied to real samples. Surface water and sediments were sampled within the river Svratka basin, in particular, from 19 sampling localities. PBDE occurrence was confirmed in sediments samples from the Svratka river (g.kg-1), PBDE were not detected in the surface water samples, their concentrations were below the detection limit, resp.; perfluorinated compounds were not detected in sediments and water samples at all.
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Annunciação, Daniel Luiz Rodrigues da. "Éteres difenílicos polibromados (PBDE) em sedimentos do Lago Paranoá, DF." reponame:Repositório Institucional da UnB, 2017. http://repositorio.unb.br/handle/10482/24184.
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Tese (doutorado)—Universidade de Brasília, Instituto de Química, Programa de Pós-Graduação em Tecnologias Química e Biológica, 2017.Submitted by Raquel Almeida (raquel.df13@gmail.com) on 2017-06-19T20:42:44Z No. of bitstreams: 1 2017_DanielLuizRodriguesdaAnnunciação.pdf: 3590633 bytes, checksum: b0707d9e03726a959b6e2a28b16beaa5 (MD5)
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Esse estudo buscou investigar a ocorrência de PBDE em sedimentos do Lago Paranoá - DF. Para tanto, um método analítico foi desenvolvido, validado e aplicado para determinação de nove congêneres (BDE-28, BDE-47, BDE-66, BDE-85, BDE-99, BDE-100, BDE-138, BDE-153 e BDE-154) em amostras de sedimento. O método consistiu na extração sólido-líquido assistida por ultrassom, seguido de etapas de clean-up e análise por cromatografia gasosa com detecção por captura de elétrons. O método se mostrou seletivo, linear (R > 0,9967), tendo valores de LOD (0,03 a 0,32 ng g-1 ) e LOQ (0,1 a 1,1 ng g-1 ) compatíveis com níveis de PBDE encontrados na literatura, recuperações entre 87,7±6,6% (BDE-138) e 98,7±1,4% (BDE-28) e boa precisão. Sete amostras de sedimento do Lago Paranoá foram investigadas onde foi possível verificar níveis de PBDE variando entre 0,143±0,005 (BDE-28) e 8,1±0,4 ng g-1 (BDE- 66). Níveis mais elevados para ƩPBDE foram observados nas imediações das estações de tratamento de esgoto Sul (19±2 ng g-1 ) e Norte (8,79±0,03 ng g-1 ), corroborando com o papel do lançamento de esgotos como uma das principais fontes de aporte de PBDE. Verificou-se semelhança entre os perfis de concentração dos congêneres nos sedimentos com a proporção de PBDE na formulação comercial pentaBDE (DE-71). A distribuição dos PBDE no ambiente, estimada pelo modelo de fugacidade do software EQC Model (level 1), sugeriu sua presença no ar (0,009 a 0,5 ng m-3 ), no aerossol (0,001 a 0,012 ng m-3 ), na coluna de água (0,004 a 0,2 ng L-1 ), nos sólidos suspensos aquáticos (0,7 a 40,5 ng g-1 ), em solos (0,07 a 4,1 ng g-1 ) e em peixes (0,437 a 24,7 ng g-1 ). Tais resultados foram compatíveis com aqueles descritos na literatura para estes compartimentos. Estimou-se, por meio do software EQC Model, um aporte de cerca de 220 toneladas de PBDE para o Lago Paranoá. A concentração de PBDE na água intersticial dos sedimentos foi estimada e comparada com valores de PNEC (predicted no-effect concentration) indicando provável risco a biota referente aos congêneres (BDE-47, BDE-66 e BDE-99) e evidenciado a necessidade de maiores investigações. Para a coluna de água, esta abordagem não evidenciou risco provavelmente em função da elevada hidrofobicidade dos PBDE aliada à sua tendência à bioconcentração. Este trabalho é um dos primeiros registros da presença de PBDE em sedimentos coletados no Brasil, servindo com suporte à geração de indicadores de ii qualidade mais autênticos com o cenário atual, à medida que as informações sobre a presença de PBDE em vários compartimentos ambientais ainda são escassos em nosso país.
This study investigated the occurrence of PBDE in sediments of Paranoá Lake, in the Brazilian Federal District. An analytical method was developed, validated and applied for the determination of nine congeners (BDE-28, BDE-47, BDE-66, BDE-85, BDE-99, BDE-100, BDE- BDE-154) in sediment samples. The method was based on ultrasonic solid-liquid extraction, followed by clean-up and analysis by gas chromatography coupled to electron capture detection. The method was selective, presented good linearity (R > 0.9967) and values of LOD (0.03 to 0.32 ng g-1 ) and LOQ (0.1 to 1.1 ng g-1 ) compatible with PBDE levels of found elsewhere. Recoveries were between 87.7 ± 6.6% (BDE-138) and 98.7 ± 1.4% (BDE-28) with good precision. Seven sediment samples from Paranoá Lake were investigated and PBDE levels ranged from 0.143 ± 0.005 (BDE-28) to 8.1 ± 0.4 ng g-1 (BDE-66). Higher levels of ƩPBDE were observed in points located nearby South (19 ± 2 ng g-1 ) and North (8.79 ± 0.03 ng g-1 ) sewage treatment plants, corroborating with the role of wastewater disposal as one of the main sources of PBDE. A similarity between the concentration profiles in sediments and the proportion of PBDE in the commercial pentaBDE formulation (DE-71) was observed. The distribution of PBDEs in the environment, estimated by the fugacity model of the EQC Level 1 software, suggested their presence in the air (0.009 a 0.5 ng m-3 ), in the aerosol (0.001 a 0.012 ng m-3 ), at the water column (0.004 a 0.2 ng L-1 ), at the aquatic suspended solids (0.7 a 40.5 ng g-1 ), in soils (0.07 a 4.1 ng g-1 ) and in fishes (0.437 a 24.7 ng g-1 ). These results were comparable with those described in the literature for these compartments. It was estimated, through the EQC Model software, a contribution of about 220 tons of PBDE to Lake Paranoá. The concentration of PBDE in the interstitial water was estimated and compared to predicted no-effect concentration (PNEC) values indicating a probable risk for the congeners (BDE-47, BDE-66 and BDE-99) as well as evidencing the need for further investigations. Risk was not evidenced for the water column probably due to the high hydrophobicity of the PBDEs and their tendency for bioconcentration. This work is one of the first reports of the presence of PBDE in sediments collected in Brazil, supporting the generation of more authentic quality indicators considering the current scenario, as the information about the presence of PBDE in several environmental compartments is still scarce in our country.
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Mauch, Abbey L. "PBIS Strategies and Support After Training: A Follow-Up Study." Miami University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=miami1562157130532644.
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Chikh, Amirouche. "Étude des mélanges PHBV/PBS et des mélanges hybrides PHBV/PBS/sépiolite : préparation, caractérisation physico-mécanique et durabilité." Thesis, Lorient, 2018. http://www.theses.fr/2018LORIS496/document.
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Ce travail de recherche consiste à étudier les relations structure-propriétés de mélanges biopolymères à base de poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) et poly(butylène succinate) (PBS). Il est divisé en trois parties. La première partie est consacrée à l'étude des propriétés des mélanges PHBV/PBS préparés par voie fondue en fonction de la composition en termes de morphologie et de propriétés rhéologiques, mécaniques, thermiques et barrières. Les résultats obtenus ont été discutés par rapport aux polymères de base. La deuxième partie est consacrée à la compatibilisation des mélanges PHBV/PBS et l'amélioration des interactions à l'interface. Les effets de l'incorporation de la sépiolite à 5% en masse et du PHBV greffé par de l’anhydride maléique (PHBV-g-MA) à 5% en masse ont été étudiés en termes de changements morphologiques montrant un effet synergique entre le compatibilisant et la nanocharge sur les l’ensemble des propriétés des mélanges PHBV/PBS. Enfin, une étude sur le recyclage a été menée à travers une évaluation des effets du nombre de cycles d'extrusion sur les propriétés des matériaux. Elle révèle qu'après 6 cycles d'extrusion, la dégradation thermo-mécanique du PHBV est significativement réduite en présence du PBSThe main objective of this work was to study the structure-properties relationships of biopolymerblends based on poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and polybutylene succinate (PBS). The work was devised into three parts. The first part was devoted to the study of the properties of PHBV/PBS blends prepared by melt compounding at different weight ratio in terms of morphology and properties. The results obtained were discussed in terms of properties and compared with the neat polymers. The second part was devoted to the study of compatibility of PHBV/PBS blends aiming to improve the interactions at the interface between the two components. The effects of both sepiolite (5% wt.) and PHBV-g-MA (5% wt.) were studied in terms of properties. The results showed a synergistic effect between the compatibilizer PHBV-g-MA and the nanofiller sepiolite though an increase in thermal, mechanical and rheological properties. The last part dealing with the recyclability of PHBV/PBS through the study of the effects of repeated extrusion cycles on the properties of materials. The results showed that after 6 reprocessing cycles the thermo-mechanical degradation of PHBV is significantly reduced in the presence of PBS
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Bourkou, Mohamed Elhaddi. "Les retardateurs de flammes bromés : effet sur les concentrations d'hormones thyroidiennes chez la femme enceinte." Mémoire, Université de Sherbrooke, 2010. http://savoirs.usherbrooke.ca/handle/11143/4050.
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Introduction : Les polybromodiphényléthers, connus sous l'acronyme de PBDE, sont abondamment utilisés en industrie (textile, plastiques, électronique) pour leurs propriétés ignifugeantes. Bien qu'elles soient utiles, ces nouvelles substances s'accumulent dans l'environnement. Des études animales et récemment chez l'humain ont montré que ces substances sont susceptibles d'interférer avec le métabolisme des hormones thyroïdiennes. Les PBDE sont des substances lipophiles et sont mobilisés largement pendant la grossesse. Cette mobilisation de polluants accumulés depuis des années dans le tissu adipeux maternel explique une exposition foetale importante. Selon notre hypothèse, les niveaux élevés des PBDE chez les femmes enceintes peuvent interférer avec le métabolisme des hormones thyroïdiennes et, par conséquence, altérer le développement psychomoteur ultérieur des enfants. Objectifs: (i) Déterminer les concentrations plasmatiques des PBDE dans une population des femmes enceintes; (ii) Examiner la relation entre les concentrations des PBDE et les niveaux circulant en hormones thyroïdiennes dans le sérum maternel. Matériel et Méthodes : Il s'agit d'une étude transversale portant sur un groupe de 195 femmes enceintes recrutées au début de la grossesse (<20 semaines). Lors de l'entrevue, après la signature du consentement, un échantillon de sang et d'urine maternels ont été prélevés et un questionnaire a été proposé à chaque participante. Les PBDE (congénères BDE-47, -99, -100, -153) ont été déterminés par la chromatographie en phase gazeuse (GC-MS). La TSH et les hormones thyroïdiennes (T4 et T3 libres et totales) ont été déterminées dans les échantillons sanguins. Les BPC, les lipides, le sélénium et le mercure sanguins ainsi que l'iode urinaire ont été mesurés afin de contrôler les facteurs confondants potentiels. Résultats : L'âge moyen des femmes était de 28±4.7 ans. Le BDE-47 a été détecté dans tous les échantillons. Les médianes des quatre congénères de PBDE les plus prévalents sont de 16.21 ng/g (max: 177,47 ng/g lipides), 1,09 ng/g (max: 74,58 ng/g lipides), 1,76 ng/g (max: 105,76 ng/g lipides), 1,14 ng/g (max: 63,66 ng/g lipides), respectivement pour le BDE-47, BDE-99, BDE-100, BDE-153. D'une façon générale, les concentrations de PBDE sont faibles et celles des hormones thyroïdiennes se situaient pour la plupart dans les intervalles des valeurs de référence. Dans les modèles de régression multiples, le BDE-47 était positivement associé à l'âge et l'âge gestationnel. Nous avons trouvé des associations positives entre la T3 et T4 totales et le BDE-47 ainsi que la somme des PBDE. Conclusion : Ces résultats suggèrent que, même à de faibles niveaux d'exposition, ces contaminants environnementaux persistants et émergents pourraient interférer avec le statut thyroïdien pendant la grossesse en augmentant les concentrations de la T3 et T4 totales. Il est peu probable que l'interférence avec les hormones thyroïdiennes au début de grossesse pourrait expliquer les effets neurotoxiques des PBDE observé chez l'enfant en développement.
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Subedi, Kamal. "Synthesis and Characterization of PbS Nano Sheets." Bowling Green State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1403097151.
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Liyanage, Geethika Kaushalya. "Infrared Emitting PbS Nanocrystals through Matrix Encapsulation." Bowling Green State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1403953924.
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Leopold, Matthew. "Förster Resonance Energy Transfer in PbS Films." Bowling Green State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1408656943.
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Ježková, Zuzana. "Komplexní zhodnocení výkonnosti společnosti PBS Industry, a.s." Master's thesis, Vysoká škola ekonomická v Praze, 2010. http://www.nusl.cz/ntk/nusl-76097.
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Comprehensive evaluation of performance analysis of PBS INDUSTRY, a.s. When evaluating the performance of PBS INDUSTRY, a.s. the financial statements of the company for the period of 2005 -- 2008 are used. Performance evaluation is done through traditional methods of financial analysis and modern methods of economic added value. The interpretation of analytical results and recommendations was made.
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Gonçalves, Renato Miani. "Poluentes orgânicos persistentes (POPs) em toninhas, Pontoporia blainvillei (Mammalia: Cetacea), coletadas no complexo estuarino-lagunar de Cananéia-Iguape, Sudeste do Brasil." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/21/21133/tde-20042012-101302/.
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A região do complexo estuarino-lagunar de Cananéia-Iguape, situada no litoral sul do estado de São Paulo, é uma área de grande interesse científico. Entre um dos mamíferos marinhos existente nessa região está a Pontoporia blainvillei, a qual teve a sua gordura subcutânea (blubber) analisada para quantificação de POPs. Os valores de concentração média obtida para as 48 amostras analisadas foram, em ordem decrescente: PCBs (1532 ng g-1); DDTs (537 ng g-1); Clordanas (64,0 ng g-1); PBDEs (38,4 ng g-1); Mirex (30,7 ng g-1); Drins (25,2 ng g-1); HCB (9,51 ng g-1); HCHs (7,59 ng g-1) e Endosulfan (6,22 ng g-1). A razão DDT/PCB encontrada foi de 0,35. As concentrações dos POPs entre machos maduros e machos imaturos apresentaram diferenças significativas (com exceção do HCH), sendo os valores encontrados para os machos maduros maiores que os valores obtidos para os machos imaturos; entre os machos maduros e fêmeas imaturas, os grupos de dados foram iguais significativamente (exceção para o DDT e mirex); entre os machos imaturos e fêmeas imaturas, os grupos de dados apresentaram igualdade significativa para todos os POPs. Foi encontrada correlação entre os POPs e a idade dos indivíduos estudados, bem como correlação forte entre PCB x PBDE, PCB x DDT e PBDE x DDT.Forty eight samples of subcutaneous fat (blubber) of Pontoporia blainvillei were analyzed for the quantitation of persistent organic pollutants (POPs). This marine mammal lives in the estuarine complex of Cananéia-Iguape, São Paulo-BR. The average concentration values of POPs was: PCBs (1532 ng g-1); DDTs (537 ng g-1); Chlordanes (64.0 ng g-1); PBDEs (38.4 ng g-1); Mirex (30.7 ng g-1); Drins (25.2 ng g-1); HCB (9.51 ng g-1); HCHs (7.59 ng g-1) e Endosulfan (6.22 ng g-1). Adult male were those with the highest concentrations of POPs. The DDT/PCBs ratio was equal to 0.35, showing an increase in concentration of PCBs in this area (compared with earlier studies). The concentrations of POPs were different (except for HCH) for mature males and immature males. Between males mature and immature females, the data were significantly (except for DDT and mirex) equal. Between immature males and immature females, data groups were significantly equal for all POPs. Moderate correlation was found between POPs and age, as well as strong correlation between PCB x PBDE, PCB x DDT and PBDE x DDT.
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Letcher-Boeve, Debra Dennet. "Positive Behavior Intervention and Supports (PBIS) and School Culture| A Mixed Method Study on the Effects of Implementation of PBIS in an Urban K-8 School." Thesis, Concordia University Irvine, 2017. http://pqdtopen.proquest.com/#viewpdf?dispub=10601909.
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School culture develops as staff members interact with each other, the students, and the community. It becomes the guide for behavior shared among members of the school at large. School culture is a self-repeating cycle; culture is shaped by the interactions of the personnel, and the actions of the personnel become directed by culture (Hinde, 2004). The culture of a school can be a positive influence on student learning or it can inhibit the functioning of the school. Stakeholders in any environment prefer to be in a situation that is appealing and welcoming. When students attend school, the expectation is that it is a place where they like to be, a place that offers support and encouragement, and a place where physical comfort levels are optimal (MacNeil, Prater, & Busch, 2009). Research indicates school culture plays a significant role in educational reform efforts (Gruenert & Whitaker, 2015).
This study investigated how perceptions of teachers, support staff, and administrators affect school culture and academic achievement, and aimed to define how Social-Emotional Learning (SEL) impacts school culture. The data collected and the statistical tests performed included Correlations, a Mann-Whitney Test, and a One-way Analysis of Variance (ANOVA). The SCS-FF Open-ended responses were coded and synthesized, and interviews with six certificated employees were coded and categorized into nine themes divided into four meta-codes. Lack of implementation with fidelity and consistent progress monitoring of the PBIS program suggests that there is a lack of cohesiveness shared among staff members at XYZ K-8 School. Consistent expectations for all stakeholders, set forth by administration, emerged as imperative to program success and a positive school culture.
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Rydén, Andreas. "Synthesis of organobromines as a tool for their characterisation and environmental occurrence assessment." Doctoral thesis, Stockholms universitet, Institutionen för material- och miljökemi (MMK), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-95649.
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Polybrominated diphenyl ethers (PBDEs) have been intensively used as flame retardants (FRs) and have become ubiquitous environmental pollutants. PBDEs form hydroxylated PBDEs (OH-PBDEs) as metabolites. Further, some OH-PBDEs and methoxy-PBDEs (MeO-PBDEs) are natural products. These are all compounds of environmental and health concern and it is therefore important to confirm their identity and to assess their environmental levels and toxicities. Hence, it is vital to obtain authentic reference standards of individual PBDEs and OH/MeO-PBDEs. The thesis main aim was to develop synthesis methods of congener specific PBDEs, OH- and MeO-PBDEs. The second aim was to identify and quantify PBDEs, OH- and MeO-PBDEs in environmental samples. The third was to propose an abbreviation system for FRs. O-Arylation of brominated phenols, using either symmetrical or unsymmetrical brominated diphenyliodonium salts, was selected for synthesis of PBDEs and OH-/MeO-PBDEs. A total of 16 MeO-PBDEs, 11 OH-PBDEs, 1 diMeO-PBDE and 1 EtO-MeO-PBDE were synthesised. Three novel unsymmetrical diaryliodonium triflates were synthesised and used in synthesis. Optimisations were made to construct a reliable general method for congener specific PBDE synthesis, which was used in the synthesis of 8 representative PBDE congeners. The products were generally characterised by electron ionisation mass spectrometry (EIMS) and nuclear magnetic resonance (NMR) spectroscopy. Identification of PBDEs and OH-PBDEs in various matrixes was based on gas chromatographic and mass spectrometric analyses. Fourteen OH-PBDE congeners were identified in a pooled human blood sample. One previously uncharacterised natural PBDE analogue was identified as 6-OH-6’-MeO-BDE-194, and quantified in Swedish blue mussels. PBDE congeners and other BFRs were identified and quantified in workers and dust from a smelter in Sweden. A structured and practical abbreviation system was developed for halogen- and phosphorus containing FRs.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Submitted. Paper 4: Manuscript.
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Buettner, Denise A. "The Effect of PBIS on the School Environment and Test Scores." Thesis, Lindenwood University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3598020.
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Since the beginning of the Positive Behavior Interventions and Support (PBIS) program in the Study School District there has not been an evaluation of its effectiveness in reducing student discipline referrals and student suspensions and its success in promot-ing a positive learning environment leading to improved academic achievement.
This study determined the effectiveness of the Positive Behavior Interventions System (PBIS) in the Study School District. It focused on determining the fidelity and consistency of implementation of PBIS in the District, the effect of PBIS on reduction of office discipline referrals and student suspensions from school, teacher attitudes toward implementation of PBIS, teacher morale since inception of PBIS, and parent perceptions of the effectiveness of PBIS in promoting positive student behavior.
The results of this mixed methods study determined that there was a difference in the number of office discipline referrals during the four years since implementation of PBIS. The study also determined there was a difference in the percentage of referrals in the three major types of categories of office discipline referrals; school regulations, violent, and nonviolent. When the study analyzed the standardized test scores grades third through seventh and high school, did not evidence a measureable difference in student academic achievement based on ISAT performance during the four years following the implementation of PBIS. However, eighth grade did evidence a measureable difference in student academic achievement. Finally, the study determined there was not a measureable positive perception by staff and parents of PBIS with the exception of one statement on a Likert Scale survey.
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Chow, Ka Lai. "Combined photocatalysis and phytoremediation for efficient treatment of polybromodiphenyl ethers (PBDES)." HKBU Institutional Repository, 2013. https://repository.hkbu.edu.hk/etd_oa/63.
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Brominated flame retardants have been widely used in industry. There is a rapidly growing public concern about their ubiquity in the environment. This project investigated the possible removal treatments of polybrominated diphenyl ethers (PBDEs) using two treatment methods: (I) photocatalysis by TiO2 and (II) phytoremediation by Oryza sativa and Phragmites australis, and a combined system involving these two technologies. Advanced oxidation process (AOP) is a promising technology for removing emerging chemicals. In this case, nano-scaled titanium (IV) oxide was applied to evaluate its capability in the degradation of BDE-209 under visible light. The residual PBDE congeners after reaction were analyzed by gas chromatography-mass spectrometry (GC-MS). The half-life for removing BDE-209 by TiO2 was 3.05 days under visible light. Tetra- and penta-BDEs were the major degraded products of BDE-209. Optimum conditions for photocatalytical degradation of BDE-209 was found to be pH 12 (93% ± 1%), at least 5 mg/L (93 ± 1.70%) of humic acid and in the form of anatase/rutile TiO2 (82% ± 3%). Incomplete removal of PBDEs by water treatment plants and point-source contamination may lead to their discharge into water bodies and ultimately into soils. Consequently, the second part of the project was phytoremediation of PBDEs. Uptake of BDE-209 by rice cultivars, namely Fengmeizhan, Hefengzhan and Guangyinzhan, and common reed were examined by 60-day cultivation in sterilized BDE-209 spiked soil. Hefengzhan possessed the greatest ability in the removal and accumulation of BDE-209 among the three cultivars, especially when associated with Glomus intraradices, at pH 7. A series of plant-contamination sorption analyses were also employed for pathway studies of PBDEs uptake by rice. A partition-limited model was applied for describing and estimating the uptake of BDE-209 by rice roots. The average quasi-equilibrium factors (apt) of BDE-47, -99 and -209 in root uptake were 1.44 × 10-3 , 0.966 × 10 -3 and 0.115 × 10-3 in sand (< 1), implying a non-equilibrium state of the movement of molecules and a dominant passive transport uptake. From the result of sorption analysis of dead and fresh roots, the apoplastic pathway likely dominated the transport of PBDEs into root cells. These results provide essential information on the uptake mechanism of PBDEs into plants. Based on the results from photocatalysis and phytoremediation, a combined photocatalysis (TiO2 and visible light) and constructed wetland system (Oryza sativa (Hefengzhan) and Phragmites australis (common reed) was set up for comparing PBDEs removal efficiencies. The removal percentages of BDE-209 in the combined system were found to be promoted when compared to the individual systems, which could be explained by enhanced biodegradability of PBDEs in photocatalysis. Therefore, the proposed advanced wastewater treatment technology (combined photocatalysis and constructed wetland systems) might help to degrade and eliminate BDE-209 in the wastewater, and thus reduce the risks of marine contamination by discharging these incompletely or partially treated wastewaters containing PBDEs.
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Cott, Andrew. "An examination of analysis and optimization procedures within a PBSD framework." Manhattan, Kan. : Kansas State University, 2009. http://hdl.handle.net/2097/2318.
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Mistry, Bhavesh V. "Analysis of SEDS proteins and their cognate PBPs in Streptomyces coelicolor." Thesis, Swansea University, 2008. https://cronfa.swan.ac.uk/Record/cronfa42448.
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The rodA and ftsW genes encode polytopic membrane proteins that are essential for bacterial cell elongation and division, respectively. These genes are highly conserved among bacteria with a peptidoglycan cell wall and belong to the SEDS ("shape, elongation, division, and sporulation") gene family. Each SEDS gene is invariably linked with a cognate class B high-molecular weight penicillin-binding protein (HMW PBP) gene. Four such pairs of genes are found in the genome of filamentous differentiating Streptomyces coelicolor. This study focused on characterization of four SEDS genes [SC02085 (ftsW), SC02607 (sfr), SC03846 (rodA) and SC05302 (rodA2)] and SC02090 (ftsi) and SC02608 ipbp2) [cognate HMW PBP genes ftsWand sfr, respectively]. Computational analysis of each SEDS gene locus revealed that each gene is a part of specific gene cluster. Construction of disruption mutants of each SEDS gene revealed ftsW, sfr and rodA2 are dispensable for growth and survival of S. coelioclor, whereas rodA is essential. Mutation of sfr or rodA2 did not cause gross changes to growth and septation of the organism. However, the mutation in sfr made the spores susceptible to heat, SDS and cell wall specific antibiotics. Similar effects were observed in the php2 (cognate HMW PBP gene of sfr) disrupted mutant. The susceptibility of the spores of sfr and php2 mutants to such a physical and chemical stress implies an important role of these genes in spore wall synthesis. Disruption of either or the cognate ftsI gene blocked the formation of sporulation septation in aerial hyphae. The inability of spiral polymers of FtsZ to reorganize into rings in aerial hyphae of these mutants indicates an early pivotal role of an FtsW-FtsI complex in cell division. Mutants of ftsQ were also unable to sporulate and the cytological analysis of this mutant showed that it was blocked at a later stage in cell division, during septum closure. Analysis of FtsZ distribution in ftsQ mutant aerial hyphae revealed that concerted assembly of the complete divisome was not required for Z ring stabilization in this mutant. Complete cross-wall formation in the vegetative hyphae of all three fts mutants imply that the typical bacterial divisome functions specifically during non-essential sporulation septation. Thus, it provides a unique opportunity to investigate the function and dependencies of individual components of the divisome in vivo.
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Otten, Frank. "Strukturierung und elektrische Eigenschaften von Gasphasen-generierten PbS Nanokristall-Filmen / Structuring and electronic properties of gasphase-generated PbS nanocrystal films." Gerhard-Mercator-Universitaet Duisburg, 2005. http://www.ub.uni-duisburg.de/ETD-db/theses/available/duett-10032005-145159/.
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Nanocrystal films may be used as detector material in sensors, as charge storage or conducting channels in devices. In this work lead sulphide (PbS) nanocrystals are generated in the gas-phase and deposited onto substrates forming nanocrystal films. A technology is developed for lateral structuring of these films on the substrate and to process them further by microelectronic standard processes. The pattern of the nanocrystal film is scaled down by several hundreds of nanometers compared to the used photoresist mask pattern. The responsible mechanism is found by consideration of physical mechanisms and usage of a trajectory simulation program. For basic electrical investigation a system is designed for production of nanocrystal films and electrical characterization under clean conditions. Noise measurements and I-V characterizations are performed. Both, single charge transport and charge transport through the interface of nanocrystal film and substrate have been found. The volume of the nanocrystal film is for the current transport not important. PbS nanocrystal films can be used in future devices for definition of high resolution current paths. Current designs can be used to downscale the device patterns without applying high resolution lithography. The parallel process technology with optical lithography still can be used to implement the films into microelectronic devices. With the trajectory simulation program the geometry can be predicted. The developed technology and the results can be transmitted to other material systems.
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Meneses, Lady Virginia Traldi. "Aspectos institucionais, legais, políticos e técnicos para a implementação da Convenção de Estocolmo sobre Poluentes Orgânicos Persistentes: os éteres difenilícos polibromados." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/6/6134/tde-05052017-100647/.
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Novos poluentes orgânicos persistentes (POPs) têm sido adicionados à lista da Convenção de Estocolmo, exemplificado nesta pesquisa pelos éteres difenílicos polibromados (polybrominated diphenyl ethers-PBDEs) aplicados como retardantes de chama em diversos artigos de consumo (eletrônicos, têxteis, móveis, automóveis e na construção civil). São substâncias semi voláteis, persistentes no ambiente, bioacumulativos nos tecidos adiposos e podem interferir no sistema endócrino humano e dos animais. Os países signatários devem cumprir as medidas estabelecidas e enfrentam desafios para a sua implementação, a julgar pelos poucos países que atualizaram os Planos Nacionais de Implementação (National Implementation Plans-NIPs). Esta pesquisa teve por objetivo identificar os aspectos institucionais, legais, políticos e técnicos para a implementação das exigências oriundas da Convenção de Estocolmo, no que diz respeito aos PBDEs, realizar revisão sistematizada da literatura sobre os artigos colocados no mercado e em unidades de reciclagem de resíduos contendo PBDE e apresentar as experiências de dois países na implementação das medidas. O método de pesquisa de estudo de casos comparados, com o delineamento de casos mais diferentes com o mesmo resultado, foi empregado para a República Tcheca e a Suécia, apoiado por análise de congruência. Entrevistas foram realizadas com profissionais envolvidos com as atividades para a elaboração e a implementação da Convenção de Estocolmo. A revisão sistematizada para PBDEs indicou o aumento da quantidade de artigos científicos a partir de 2008 e os estudos revelaram a presença de PBDEs na poeira e no ar em ambientes internos, como residências e escritórios e nos ambientes internos e externos às instalações de reciclagem de resíduos com avaliação da exposição humana aos PBDEs, e novos estudos devem ser desenvolvidos. A revisão mostrou também que na América Latina e Caribe as publicações ainda são em pequeno número, mas o Brasil tem posição de destaque. O estudo dos dois países revelou que é requerida uma complexa abordagem para a transposição das medidas em âmbito nacional, incluindo legislação sobre gestão de produtos químicos, arranjos institucionais nacionais para a implementação do NIP apoiados por instituições de pesquisas científicas, existência de programas de monitoramento ambiental e de controle de POP-BDEs em artigos de consumo colocados no mercado. Os principais desafios técnicos são a segregação de plásticos, contendo PBDEs em parceria com o setor industrial para identificar o conteúdo PBDEs em artigos em uso que se tornarão resíduos e a viabilização do uso das alternativas tecnológicas. Os benefícios gerados pela implementação da Convenção são a proteção da saúde humana e do meio ambiente, a melhoria da governança, a promoção de assistência técnica, a maior visibilidade sobre riscos de uso de produtos tóxicos, em especial os POPs, a maior interação entre a ciência e as políticas públicas e o aumento das pesquisas cientificas. A Convenção de Estocolmo é um acordo complexo porém contribui com o entendimento mais amplo dos riscos químicos e sobre gestão coordenada das substâncias químicas.Additional new Persistent Organic Pollutants (POPs) have been included to the list of Stockholm Convention, in the research exemplified by means of polybrominated diphenyl ethers (PBDEs) which resist degradation, are transported far from their place of release, where they accumulate in terrestrial and aquatic ecosystems and possess toxic properties, since they are classified as endocrine disruptive chemicals. They were used as brominated flame retardants and applied in many articles/consumer products such as electronics, textiles, vehicles, furniture and building materials. The signatories countries must comply with obligations and measures taken by Convention however they are facing many challenges in order to implement them, once few countries submitted the updated National Implementation Plans (NIPs) to the Convention. This research aims at identifying the institutional, legal, technical and politics aspects in order to transpose those measures to the national level, conducting a systematized research of literature on consumer products that may contain c-BDE put in the market besides recycling units of articles upon becoming wastes, consisting of, containing or contaminated with a chemical PBDEs and presenting the experience of two countries in implementing PBDEs actions plans of the NIPs. The comparative case studies was used as the research method, improved by the most different cases and most similar outcomes, designed for two countries as Czech Republic and Sweden, supported by the congruence analyses. Standardized interviews were applied to professionals involved in elaborating and implementing the Stockholm Convention in the countries. The systematized research indicated the increase from 2008 of the scientific number articles related to PBDEs which presented the occurrence of PBDEs in indoor house, office and recycling units dust and air internal and outdoor environments nearby waste electronic and electric equipment recycling units, with human exposure analyses related to and the researches must be continued, accordingly the conclusions. The comparative case studies of two countries revealed the requirement of a complex chemical substances management approach in order to transpose the PBDEs obligations to the national level, including the industrial chemical and environmental legislations, especially on POP-BDEs in products, a integrated institutional arrangement with the scientific institutional support, environmental monitoring programs and chemical control of the spread of POP-BDEs substances present in a number of consumer products put on the market; as the main challenges are the segregation of plastics containing PBDE in order to avoid recycled articles containing PBDEs and the importance of dialogue with the industrial sector in order to identify the PBDEs content in articles in use and to evaluate technology alternatives to PBDEs as well as promote technical capacities to raise awareness of chemicals to importers and private sector. The benefits generated by the Convention implementation are protection on healthy and environmental, the governance improvement, technical assistance promotion, POPs visibility, science and politics integration and the increase of scientific research.
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Elfurawi, Umaima. "Optical and electronic properties of PbS colloidal nanocrystals." Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/12542/.
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This thesis describes the optical and electrical properties of colloidal PbS nanocrystals synthesized in aqueous solution and comprising different capping ligands and/or matrices. Post-synthesis thermal annealing of thiol-capped PbS colloidal quantum dots (QDs) is discussed and shown to provide a novel means of tailoring the morphological and electronic properties of the QDs. Two different regimes are reported: at low annealing temperatures (< 80oC), the annealing provides a simple strategy for controlling and narrowing the QD size distribution and photoluminescence emission. At higher annealing temperatures, the displacement of the thiol-ligands promotes the fusion of nearby quantum dots thus leading to interconnected nanocrystals. A study of the circularly polarized magneto- photoluminescence of colloidal PbS nanocrystals under the influence of a magnetic field up to 30T is presented. A semiclassical model for the population of polarized excitons is used to account for the measured magnetic field and temperature dependence of the degree of circular polarization of the QD photoluminescence. The g-factor, gX, of the exciton and its dependence on the QD size is reported for the first time. The value of gX increases from 0.1 to 0.3 at low temperature with decreasing the nanocrystal diameter from 9 to 4 nm. The transport properties of a PbS QDs thin film deposited between two electrodes are investigated. This study reveals a non-linear dependence of the current on the applied bias. At low temperature (T<100 K), the conduction is limited by the charging energy (~20 meV) of the quantum dot. The fabrication of a solid-state device based on porous TiO2 impregnated with PbS QDs is discussed. The photovoltaic response of the device in the visible and near infrared wavelength range is obtained by exploiting the Schottky junction that forms at the interface between the PbS/TiO2 film and a metallic contact.
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Goodenough, M. R. "Electrohydrometallurgical processing of covelite (CuS) and Galena (PbS)." Thesis, Imperial College London, 1987. http://hdl.handle.net/10044/1/38336.
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Uprety, Prakash. "Plasmonic Enhancement in PbS Quantum Dot Solar Cells." Bowling Green State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1403022047.
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Antu, Antara Debnath. "Morphology and Surface Passivation of Colloidal PbS Nanoribbons." Bowling Green State University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1499383746861722.
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Neupane, Chandra Prasad Neupane. "Time Resolved Optical Spectroscopy of Colloidal PbS Nanosheets." Bowling Green State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1530805332385177.
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Premathilaka, Shashini M. "Synthesis and Optical Properties of Colloidal PbS Nanosheets." Bowling Green State University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1561463157379607.
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Saloniemi, Heini. "Electrodeposition of PbS, PbSe and PbTe thin films /." Espoo [Finland] : Technical Research Centre of Finland, 2000. http://www.vtt.fi/inf/pdf/publications/2000/P423.pdf.
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Hortová, Miluše. "Řízení nákladů v podniku PBS Velká Bíteš, a.s." Master's thesis, Vysoké učení technické v Brně. Fakulta podnikatelská, 2012. http://www.nusl.cz/ntk/nusl-223678.
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The diploma thesis is focused on cost control management in a manufacturing company. The diploma thesis deals with the calculation of product. It describes existing system of calculations and on the basis of theoretical knowledge suggest effective solutions. This solution should help to find hidden costs.
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Schrimpel, Michal. "Parovzduchová turbína s využitím přeplňovacích turbodmychadel PBS Turbo." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2008. http://www.nusl.cz/ntk/nusl-227963.
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The purpose of this analysis is used PBS Turbo turbochargers like a steam-air turbine in the Flexible Energy System. The System is analogy of Brayton cycle with high efficiency, but heat is transferred to the cycle through a heat exchanger. Main parts of this work are the literature search, the thermodynamic model of the steam-air cycle, and solution for other possibilities. The goal is to find maximum available electrical output and efficiency. The thermodynamic model is used to: - check computation of the standard turbocharger - computation of the steam-air turbine contain one turbocharger - computation of the steam-air turbine contain two turbochargers. The steam-air turbine is different from the turbocharger. They are compared and than there is found some new design of the new steam-air turbine. The one-turbocharger steam-air turbine is used to test steam-air cycle. The double-turbocharger steam-air turbine is suitable for Flexible Energy System. This solution has a lot of advantages.
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Dunbar, Michael Nathan. "Identifying Critical Incidents That Helped or Hindered the Sustainment of Positive Behavior Interventions and Supports in Schools (PBIS) with Five Years or more of Implementation in One School Division." Diss., Virginia Tech, 2020. http://hdl.handle.net/10919/98787.
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Identifying Critical Incidents That Helped or Hindered the Sustainment of Positive Behavior
Interventions and Supports in Schools (PBIS) with Five Years or more of Implementation in One School Division
Michael N. Dunbar
Abstract
The purpose of this qualitative study was to identify critical incidents that helped or hindered the sustainment of Positive Behavior Interventions and Supports (PBIS) in schools with five years or more of implementation in one school division. This study highlighted information related to PBIS because of its comprehensive approach to school discipline. The research sought to answer the following questions:
1. What critical incidents do building-based leadership team members indicate have helped the sustainment of PBIS?
2. What critical incidents do building-based leadership team members indicate have hindered the sustainment of PBIS?
Participants of this study included one representative from five different building-based PBIS leadership teams from a school division in the Commonwealth of Virginia. Data were collected and analyzed to determine the building-based PBIS leadership team member's perception of what constituted the sustainment of PBIS, connection between a school's Tiered Fidelity Inventory score and sustainment, key components of implementing PBIS with fidelity, importance of implementing PBIS with fidelity, most challenging sustainable elements of fidelity, and least challenging sustainable elements of PBIS. This research will further contribute to the existing body of literature through a thorough description of critical incidents that have helped or hindered the sustainment of PBIS. Matthews, McIntosh, Frank, and May (2013) stated fidelity is the degree to which a new initiative is delivered as intended in order for PBIS to be sustained. The research identified a need for establishing a stronger understanding of core components of fidelity, establishment of a leadership team, staff buy-in, data driven decisions, and building capacity. Participants also indicated the essentialness of consistency in establishing and utilizing school-wide expectations. Leadership team members emphasized the importance of administrative support from initial stages of implementation through sustainment. In addition, the study found resources to be a vital component to the reward system of PBIS. Participants discussed struggles they endured without proper resources. Ongoing training was also designated as a critical component of sustaining PBIS. Participants similarly indicated the consistent use of data was essential to setting goals and action planning.Doctor of Education
Identifying Critical Incidents That Helped or Hindered the Sustainment of Positive Behavior Interventions and Supports in Schools (PBIS) with Five Years or more of Implementation in One School Division Michael N. Dunbar General Abstract The purpose of this qualitative study was to identify critical incidents that helped or hindered the sustainment of Positive Behavior Interventions and Supports (PBIS) in schools with five years or more of implementation in one school division. For purposes of this study, critical incidents are those key factors – both positive or negative – that impact the sustainment of PBIS. Educators often times adopt new practices that fail because the root of the concerns were never identified and addressed. PBIS' comprehensive approach to behavior adds value to the school climate, however, there is not much research about sustaining PBIS. The researcher sought to identify these incidents as a means of helping educators sustain PBIS beyond a five-year period. The data from this study could be used to develop guidelines for sustaining PBIS. The researcher interviewed one building-based leadership team member from five different schools to gain an understanding of what constituted sustaining PBIS, key components of fidelity, purpose of the Tiered Fidelity Inventory (TFI) score, and challenges of implementing PBIS with fidelity. This study sought to answer the following research questions: 1. What critical incidents do building-based leadership team members indicate have helped the sustainment of PBIS? 2. What critical incidents do building-based leadership team members indicate have hindered the sustainment of PBIS? Participants of this study included one representative from five different building-based PBIS leadership teams from a school division in the Commonwealth of Virginia. Data were collected and analyzed to determine building-based PBIS leadership team members' perception of what constituted the sustainment of PBIS, connection between a school's TFI score and sustainment, key components of implementing PBIS with fidelity, importance of implementing PBIS with fidelity, most challenging sustainable elements of fidelity, and least challenging sustainable elements of PBIS. The TFI is an assessment tool used to determine the level of fidelity school personnel are applying the core features of PBIS (VTSS, 2018). This research will further contribute to the existing body of literature through a thorough description of critical incidents that have helped or hindered the sustainment of PBIS. Matthews et al. (2013) stated fidelity is the degree to which a new initiative is delivered as intended in order for PBIS to be sustained. This research found a stronger understanding of core components of fidelity needed to be established. Participants also indicated the essentialness of consistency in establishing and utilizing school-wide expectations. Leadership team members emphasized the importance of administrative support from initial stages of implementation through sustainment. In addition, this study found resources to be a vital component to the reward system of PBIS. Participants discussed struggles they endured without proper resources. Continuous training was also designated as critical component of sustaining PBIS. Participants similarly indicated consistent use of data was essential to setting goals and action planning. These identified critical incidents could be used to create guidelines to help educators sustain PBIS beyond a five-year period.
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Cazaunau, Mathieu. "Oxydation atmosphérique hétérogène de HAP et de PBDE : cinétique, produits et génotoxicité." Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13907/document.
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Ce travail a eu pour objectif l’étude de la dégradation hétérogène d’hydrocarbures aromatiques polycycliques (HAP) et de polybromo diphényles éthers (PBDE) en présence d’oxydants atmosphériques. La réactivité du benzo[a]pyrène et du dibenzo[a,l]pyrène pour les HAP et du BDE 153 (hexabromé) et du BDE 209 (décabromé) pour les PBDE, a été étudiée lorsqu’ils sont adsorbés sur des particules minérales modèles (des particules de silice) et exposés à l’ozone, au dioxyde d’azote ou aux radicaux hydroxyles. L’extraction et l’analyse de ces composés ont été optimisées. Le suivi de l’évolution de la concentration en composé adsorbé en fonction de son temps d’exposition à l’oxydant a permis de déterminer les paramètres cinétiques de chaque composé, pour chaque oxydant. L’influence de la concentration particulaire et de la structure moléculaire sur la réactivité a ainsi été évaluée et débattue. L’identification des produits de réactions majoritaires a été effectuée pour les réactions des HAP avec le dioxyde d’azote et les radicaux hydroxyles et les réactions des PBDE avec les radicaux hydroxyles. Enfin, l’étude de la génotoxicité des extraits de particules pour différents temps d’exposition aux oxydants a été réalisée. Cette étude regroupe une approche cinétique, une approche mécanistique et une approche toxicologiqueThis work deals with the heterogeneous degradation of polycyclic aromatic hydrocarbons (PAH) and polybromo diphenyls ethers (PBDE) with various atmospheric oxidants. The reactivity of Benzo[a]pyrene (BaP) and dibenzo[a,l]pyrene (DalP) for PAH and BDE 153 and BDE 209 for PBDE, had been studied when they are adsorbed on a model of mineral particles (silica particles) and exposed to ozone, nitrogen dioxide and hydroxyl radical. Extraction and analyse of compounds were optimised. For all studied reactions, kinetic parameters were obtained following the remaining concentration of compound for different exposure times. Influence of the particle loading and molecular structure on the reactivity had been evaluated and discussed. Identification of the main degradation products was made for the reaction of PAH with nitrogen dioxide and hydroxyl radical and for the reaction of PBDE with hydroxyl radical. Then, the genotoxicity of the particle extracts was made for different exposure times. This study talks about kinetics, mechanistic and genotoxicity
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Ferrari, Raíssa Santos. "Quantificação de PBDEs em amostras de sedimentos de Ribeirão Preto e avaliação da toxicidade do BDE-209 em células HepG2 sob influência de indução autofágica." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/59/59138/tde-17012017-092455/.
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Os éteres difenílicos polibromados (PBDEs) são compostos amplamente utilizados como retardantes de chamas que foram introduzidos por volta da década de 1970, em uma gama de produtos industrializados, especialmente em aparelhos eletrônicos. No entanto, em contrapartida ao seu papel benéfico como dispositivo de segurança, esses compostos apresentam uma estrutura química que proporciona ao homem preocupantes efeitos tóxicos que, de acordo com vários estudos, são responsáveis por desencadearem problemas neurotóxicos e hormonais, assim como influenciarem no desenvolvimento de algumas doenças. Além disso, suas características físico-químicas permitem que eles sejam bioacumulados e persistentes no meio ambiente. Diante desses fatores, tornam-se importantes estudos que melhor caracterizem o mecanismo de ação desses compostos e, portanto, a proposta do projeto foi analisar os efeitos do congênere 2, 2\' ,3, 3\' ,4, 4\' ,5, 5\' ,6, 6\' decabromodifenil éter (BDE-209) em células de hepatocarcinoma humano do tipo HepG2, aplicando como método de análise os ensaios de citotoxicidade durante indução autofágica. Os resultados obtidos mostraram que o BDE-209, como observados em outros estudos do nosso laboratório, não apresentou toxicidade acentuada em comparação aos outros congêneres, pois mostrou resultados significativos apenas nas maiores concentrações. A indução autofágica, por sua vez, não proporcionou efeitos protetivos contra a citotoxicidade do BDE, pelo contrário, ela foi capaz de perturbar ainda mais a homeostasia celular e de causar necrose na presença de 25 µmol.L-1 do congênere. Suplementariamente, foram coletadas amostras de sedimentos provenientes de uma lagoa pertencente à área de recarga do aquífero Guaraní no município de Ribeirão Preto para a quantificação de PBDEs com o objetivo de determinar o nível de contaminação desse ambiente. Estas amostras foram analisadas por cromatografia gasosa com detector por captura de elétrons (CG-ECD), após um processo de extração, clean up e pré-concentração. Os resultados obtidos mostraram a presença de seis BDEs com somatórias de suas concentrações nos valores de 4,03 ng.g-1 e 5,38 ng.g-1 em duas amostras coletas, tendo como congênere em destaque o 2, 2\', 4, 4\' tetrabromodifenil éter (BDE-47).The polybrominated diphenyl ethers (PBDEs) are compounds widely used as flame retardants, introduced around 1970, in a diversity of industrial products especially electronics. However, in contrast to its beneficial role as a safety device, these compounds have a chemical structure, which provides to humans worrisome toxic effects, because according to several studies, they are responsible for triggering neurotoxic and hormonal problems, as well as influence in the development of some diseases. Moreover, its chemical composition allows them to be bioaccumulated, which gives potential effects, since they are persistent in the environment. Given these factors, studies that can better describe these compounds action mechanism are important. Therefore, the proposal of this project was to analyze the effect of 2, 2\' ,3, 3\' ,4, 4\' ,5, 5\' ,6, 6\'-decabromodiphenyl ether (BDE-209) using as model the human hepatocellular carcinoma cells, HepG2, applying cytotoxicity assays during autophagic induction. The results showed that BDE-209, as observed in other studies of our group, induced no severe toxicity like other congeners as it showed significant results only in higher concentrations. The autophagic induction had no protective effects against the BDEs cytotoxicity, on the contrary, it was able to affect cells homeostasis and cause necrosis in the presence of 25 mol.L-1 of the congener. Additionally, sediment samples were collected from a recharge point of Guaraní aquifer in Ribeirão Preto for quantification of these compounds to determine the level of contamination in this environment. These samples were analyzed by gas chromatography with electron capture detector (CG-ECD) after a process of extraction, clean up and preconcentration. The results showed the presence of six BDEs with total concentration of 4.03 ng.g-1 and 5.38 ng.g-1 in two samples collected, which the main congener was 2, 2\', 4, 4\' tetrabromodiphenyl ether (BDE-47).
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Lundgren, Magnus. "Coxsackievirus B3 Infection and Host Defence Responses Change the Metabolism of PBDE." Doctoral thesis, Uppsala universitet, Institutionen för medicinska vetenskaper, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-108849.
Full textAbstract:
It has been suggested that the rising amounts of chemicals in the environment may affect host resistance and increase susceptibility to infections. Studies have also shown that infections can change the toxicity of pollutants. The aim of this thesis was to study interactions between environmental pollutant exposure in terms of polybrominated diphenyl ethers (PBDE) and a common human coxsackievirus B3 (CVB3) infection adapted to Balb/c mice. The studies focused on virus levels, cytokines, metabolising cytochrome P450 (CYP) enzymes and tissue distribution of PBDE. A novel finding was an organ-specific effect of CVB3 infection on the metabolising capacity of PBDE. The PBDE metabolising enzyme CYP2B10 was down-regulated by the CVB3 infection in the liver, up-regulated in the lungs, but not affected in the pancreas. Accordingly, CVB3 infection increased the concentration of PBDE in the livers of infected mice. However, serum levels of PBDE were not affected by the infection, indicating that serum does not reflect the actual organ exposure of PBDE in infected individuals. The change in metabolising capacity was likely mediated by infection-induced cytokines and associated effects on the nuclear factor-κB (NF-κB) pathway. PBDE drastically decreased serum levels of several cytokines and chemokines, an event that may create a slot for viruses to replicate. Accordingly, some results show that infected mice exposed to a high dose of PBDE had higher virus levels than mice exposed to a low dose. In conclusion, infected individuals showed organ-specific changes in metabolism and tissue levels of PBDE, which potentially could change the toxicity of PBDE. PBDE also seems to affect the fate of the infection. NF-κB activated pathways may mediate one possible mechanism underlying these effects. Thus, further investigations of this pathway are warranted. In addition, future studies should address how PBDE exposure affects viral replication.