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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Filogenia de grupo Chlorocoris baseada em morfologia e evidência total, descrição de cinco novas espécies e sinopse de Chloropepla Stal, incluindo análise cladística e biogeográfica (Hemiptera: Heteroptera: Pentatomidae)

Greve, Caroline January 2010 (has links)
Apesar da monofilia de Pentatomidae ter sido amplamente demonstrada, as relações infrafamiliares precisam ser esclarecidas. Por exemplo, um dos maiores táxons da família, a subfamília Pentatominae, ainda não é reconhecido como um grupo monofilético. Para resolver estes problemas é necessário, além de conhecer a diversidade do grupo, realizar estudos cladísticos nos níveis genéricos e cladísticos. Na presente Tese são descritas cinco novas espécies do gênero Chloropepla (Pentatominae): C. paveli, C. stysi, Chloropepla sp. nov. 1, Chloropepla sp. nov. 2 e Chloropepla sp. nov. 3. As espécies são caracterizadas, principalmente, por atributos da genitália de machos e fêmeas. Uma chave ampliada para a identificação das espécies do gênero é fornecida. A distribuição setentrional do grupo é expandida da Venezuela para a Costa Rica. Uma sinopse de Chloropepla também é apresentada, com uma descrição ampliada do gênero e diagnose das espécies, ambas baseadas em análise de parcimônia das 12 espécies conhecidas. Esta análise cladística confirmou a monofilia do grupo, baseada no peritrema ostiolar longo e evanescente, hypandrium amplo com projeções dorsais atingindo o X segmento, parâmeros cilíndricos, dirigidos dorsalmente, conjuntiva membranosa reduzida, quase que inteiramente obscurecida pela phallotheca. A relação filogenética resultante entre as espécies de Chloropepla foi submetida à BPA com as subregiões e províncias da região Neotropical como terminais. Esta análise demonstrou uma relação próxima entre as áreas amazônicas e indicou uma natureza híbrida da sub-região chaquenha. Finalmente, a relação entre oito gêneros de Pentatominae é investigada: Arvelius, Chlorocoris, Chloropepla, Eludocoris, Fecelia, Loxa, Mayrinia e Rhyncholepta. Duas análises de parcimônia foram realizadas: uma baseada somente em caracteres morfológicos e outra baseada em morfologia e em sequências ribossomais (evidencia total). Um fragmento de rDNA mitocondrial 16S e dois de rDNA nuclear 28S foram sequenciados e analisados utilindo-se o método de optimização direta. As análises apresentaram diferentes relações entre os gêneros. Contudo, algumas relações se mantêm em ambos os cladogramas: Loxa + Mayrinia + Chlorocoris (Monochrocerus), Arvelius + E. humeralis + R. humeralis and Chlorochoris (Chlorocoris) + Fecelia + Chlorochoris (Arawacoris). Os resultados obtidos enfatizam a necessidade de estudos futures sobre o uso de dados moleculares em análises genéricas e específicas em Pentatominae. Além disto, as homologias também precisam ser melhor investigas e testadas, com base em estudos cladísticos, dentro de Pentatomidae, Pentatominae e tribos. / The monophyly of Pentatomidae was already highly confirmed. However, the infra-family relationships still need to be clarified. For example, one of the largest taxa of the family, the sub-family Pentatominae is not recognized as a monophyletic group. To solve these problems is necessary to know the diversity of the group as well as to perform cladistics studies at the level of genera and species. In this thesis, five new species of the genus Chloropepla (Pentatominae) are described: C. paveli, C. stysi, Chloropepla sp. nov. 1, Chloropepla sp. nov. 2 and Chloropepla sp. nov. 3. The species are mainly characterized by features of male and female genitalia. An extended key to identification of the species of the genus is provided. The northern distribution of the group is expanded from Venezuela to Costa Rica. A synopsis of Chloropepla is also presented, with an extended description of the genus and diagnosis for the species, both based in a parsimonious analysis of the 12 know species. This cladistics analysis confirmed the monophyly of the group, based on ostiolar ruga long and evanescent, wide hypandrium, with dorsal projections flanking the segment X, parameres cylindrical, dorsally directed, membranous conjunctiva reduced, almost entirely obscured by the phallotheca. The resultant phylogenetic relationship of Chloropepla species were submitted to a BPA with the sub-regions and provinces of Neotropical region as terminals. This analysis showed a near relation among the Amazonian areas and indicated a hybrid nature of the Chacoan subregion. Finally, the relationship of eight Pentatominae genera is investigated: Arvelius, Chlorocoris, Chloropepla, Eludocoris, Fecelia, Loxa, Mayrinia and Rhyncholepta. Two parsimony analyses were performed: one based solely on morphological characters and other based on morphological plus ribosomal DNA sequences (total evidence). One fragment of 16S mitochondrial and two of 28S nuclear rDNA were sequenced and analyzed using the direct optimization method. The results of both analysis differed in the relationships of the genera. However, some relations are recovered in both cladograms: Loxa + Mayrinia + Chlorocoris (Monochrocerus), Arvelius + E. humeralis + R. humeralis and Chlorochoris (Chlorocoris) + Fecelia + Chlorochoris (Arawacoris). The results here obtained emphasize the necessity of further studies on the use of molecular data in analyses on genera and species levels in Pentatominae. Besides, the homologies also need to be better investigated and tested within Pentatomidae, Pentatominae and tribes levels, based on cladistics studies.
12

Paper receipts, something from the past? : A digital solution towards a better future

Solimanajd, Saros January 2020 (has links)
Sustainability is a hot topic now, where we try to solve problems that puts a strain on ourenvironment. While many focus on solution concerning how we consume today, there is alsoa need to look at the smaller target. Receipts are one object that have consequences both forenvironmental disruption and for concerns of human health, because of the substance that isused in the production of receipts. This thesis lifts the environmental and health issues thatreceipts has today and suggests a better, more environmentally friendly, available solution, adigital receipt, by using theories related to sustainability. Furthermore, a qualitative study isused to explore and identify a suitable solution for the task. Questionnaires and interviewshave been conducted to elevate and strengthen the solution to the design proposition through auser perspective. The result is a suggestion of a digital receipt and showcase the theory laiddown for the end design. Finally, the different problems and opportunities of the proposedsolution has been discussed for further research.
13

The Effects of BPA and its Structural Analogues on Adipocyte Differentiation

Singh, Misha 23 March 2022 (has links)
Obesity and the metabolic complications associated with it are increasing globally. Sedentary lifestyles, poor diet and genetic predisposition contribute to obesity. In addition, environmental chemicals such as Bisphenol A (BPA) may play a significant role. Exposure to BPA has been correlated with an array of adverse health effects on the endocrine system and whole-body homeostasis. This has resulted in manufacturers replacing it with structural analogues such as Tetra Methyl Bisphenol F (TMBPF), Bisphenol F (BPF), Bisphenol AP (BPAP), and fluorine-9-bisphenol (BHPF). BPA is a suspected obesogen as it can induce adipogenesis in human and murine preadipocytes. The effects of the BPA analogues listed above on adipogenesis have yet to be evaluated. The aim of this project is to investigate their adipogenic effects. For this purpose, we used 3T3-L1 mouse embryonic fibroblasts. This cell model can be differentiated into mature adipocytes with appropriate inducers including 3-isobutyl-1-methylxanthine (IBMX), insulin and dexamethasone, a synthetic steroid. To assess the effects of BPA analogues, the cells were treated with varying concentrations of TMBPF, BPF, BHPF, BPA, or BPAP in place of dexamethasone. The expression levels of mature adipocyte markers were assessed at mRNA and protein levels to determine the adipogenic potential of the analogues. Lipid accumulation was evaluated by Nile Red staining. A time course was performed to assess the expression levels of known transcriptional regulators of adipogenesis. The results indicate that TMBPF, BPF and BPA increase 3T3-L1 adipogenesis. BHPF and BPAP did not affect adipogenesis in this model. BPF appears to be at least as good as BPA at inducing adipogenesis. TMBPF, on the other hand, can induce adipogenesis to a greater extent than the other chemicals, including BPA, as evidenced by increased expression of adipogenic markers and lipid accumulation. Finally, key transcription factors C/ebpδ and C/ebpα, part of the adipogenic transcriptional cascade, were up-regulated at III two and six hours post-treatment by TMBPF. BPA also up-regulated C/ebpδ at two hours post-treatment. Though the adipogenic effects have become apparent for some of these analogues, the mechanism by which they elicit their effects remains to be discovered. More research is required to deduce the mechanism of action and to provide consensus on what the effects of these replacement bisphenols actually are.
14

IDENTIFICATION AND CHARACTERIZATION OF ESTROGEN-MEDIATED EFFECTS ON FEMALE MEIOSIS: STUDIES OF BISPHENOL A AND ESTROGEN RECEPTORS

Susiarjo, Martha January 2007 (has links)
No description available.
15

Oral Exposure of Bisphenol A During Development Affects Behavior in Adulthood in the Female Prairie Vole (Microtus ochrogaster)

Beach, Elsworth Charles January 2013 (has links)
No description available.
16

Paleobiogeography of Miocene to Pliocene Equinae of North America: A Phylogenetic Biogeographic and Niche Modeling Approach

Maguire, Kaitlin Clare 05 August 2008 (has links)
No description available.
17

Disruption of Early Pregnancy in the CF-1 Mouse: Impacts of Triclosan Alone and in Combination with Bisphenol-A

Crawford, Brent R. 10 1900 (has links)
<p>Triclosan is an antimicrobial additive found in a number of personal care and household products. Widely detected in humans, the compound has been given increasing attention due to reports of its endocrine-disrupting potential. Recent evidence indicates that triclosan is mildly estrogenic. The carefully timed event of blastocyst implantation in mammals is modulated in part by estrogen and can be disrupted by above optimal elevations in estrogenic stimulation. Here, we examined the influences of triclosan administration in inseminated female mice. Doses of 18 and 27 mg/animal/day on gestation days (GD) 1–3 reduced implantation site numbers as observed on GD 6, relative to vehicle controls and females given lower doses. Single doses of 18 or 27 mg reduced implantations when given on GD 3, whereas only 27 mg did so when given on GD 2. Subsequently, we examined the impacts on early pregnancy of triclosan in combination with the xenoestrogen bisphenol-A, which has been previously found to disrupt implantation, at doses that were individually ineffective. A combination of 4 mg BPA and 9 mg triclosan/animal/day administered on GD 1–3 reduced the number of implantations observed on GD 6 and increased the length of gestation, relative to controls and those animals simply given one or the other compound. All of these effects mimicked stronger effects seen in positive controls given 17β-estradiol. These data are consistent with the notion that triclosan has mild estrogenic properties, and show that it can act together with a known xenoestrogen to disrupt implantation.</p> / Master of Science (MSc)
18

THE IMPACT OF BISPHENOL A IN COMBINATION WITH STRESS AND DIETHYLHEXYL PHTHALATE ON IMPLANTATION, UTERINE MORPHOLOGY, AND ADHESION PROTEIN EXPRESSION IN INSEMINATED FEMALE MICE / ENVIRONMENTAL CHEMICALS AND STRESS DISRUPT IMPLANTATION

Borman, Evan D. 11 1900 (has links)
Bisphenol A (BPA), the monomer of polycarbonate plastics and epoxy resins, can disrupt intrauterine implantation of fertilized ova in mice. This effect is also induced by exposure to chronic stress or high doses of diethylhexyl phthalate (DEHP), a plasticizer found in polyvinyl chloride products. I assessed the potential combinatory effects of BPA and stress on blastocyst implantation, uterine morphology, adhesion protein expression, and urinary hormone levels. Subcutaneous injections of BPA administered from gestation days (GDs) 1–4 paired with a stressor (rat exposure across a grid) reduced the number of implantation sites on GD 6 at a dose where neither BPA nor stress had this effect on their own. Uterine luminal area was increased by BPA when paired with stress. BPA reduced epithelial cadherin (e-cadherin), a uterine adhesion protein, independently from the stressor. Urinary estradiol was significantly increased by BPA relative to controls, regardless of stress. In other experiments, effects of concurrent BPA and DEHP administered were assessed. Inseminated female mice were injected with BPA, DEHP, or BPA + DEHP from GDs 1–4. Implantation measured in uteri on GD 6 was disrupted by a combined dose but not by the individual doses. This dose also decreased the amount of e-cadherin and cadherin-11, another adhesion protein expressed by cells, while cadherin-11 was also affected by BPA alone. In further experiments designed to elucidate the interaction of BPA and DEHP, mice were fed 14C-BPA and injected with varied doses of DEHP, then tissues were excised and measured for radioactivity. When given DEHP, males and cycling and peri implantation females showed increased BPA deposition in reproductive tissues and serum. As people are commonly exposed to both DEHP and BPA through consumer products, it is important to determine their interactions and also to understand how dose-response is affected by other factors such as stress. / Thesis / Doctor of Philosophy (PhD)
19

Estudo da fotodegradação do bisfenol A em solução aquosa via fotólise direta. / Study of the photodegradation of bisphenol A in aqueous solution by direct photolysis.

Santos, Flaviane da Silva 03 October 2016 (has links)
Neste trabalho, estudou-se a degradação do bisfenol A (BPA) em solução aquosa através da fotólise direta sob radiação UV em 254 nm. Os experimentos foram realizados um reator fotoquímico tubular de vidro de 3,9 L, equipado com uma lâmpada de vapor de mercúrio de baixa pressão tubular concêntrica (36 W). Avaliaram-se os efeitos da taxa específica de emissão de fótons (0,87×10 18 ; 1,4×1018 e 3,6×1018 fótons L-1 s-1 ) e da concentração inicial de BPA (10 a 50 mg L-1 ), conforme um projeto experimental Doehlert. Os resultados dos experimentos indicaram que a degradação do BPA diminui com o aumento de sua concentração inicial, seguindo decaimento de pseudo primeira-ordem. A constante cinética de velocidade de degradação do BPA variou de 0,001 a 0,0066 min-1 , enquanto a porcentagem de degradação de BPA ao final de 120 minutos variou de 14 a 55%; já a remoção do carbono orgânico total variou entre 1,5 e 12,5%. Houve a formação de produtos persistentes e as espécies reativas de oxigênio (1 O2 oOH ) mostraram-se muito importantes durante a degradação do BPA. O rendimento quântico para fotólise de BPA foi de 0,0075 mol BPA mol fótons-1, determinado a partir dos dados experimentais através de um modelo matemático para degradação fotolítica do BPA em função do tempo. Para tanto, considerou-se um sistema de tratamento formado por um reator tubular e um tanque de mistura com recirculação entre eles, sendo o reator tubular tratado como uma série de três reatores contínuos de mistura perfeita (CSTR) associados entre si. Através da análise estatística dos dados experimentais para duas respostas (constante específica de degradação do BPA e porcentagem de degradação do BPA ao final de 120 minutos) avaliaram-se os efeitos das variáveis envolvidas (concentração inicial de BPA e taxa específica de emissão de fótons). / The aim of this study was to evaluate bisphenol A (BPA) degradation in aqueous solution by direct photolysis under UV radiation at 254 nm, considering the effects of the specific rate of photon emission (0.87×1018; 1.4×1018 and 3.6×1018 fótons L-1 s-1) and the initial BPA concentration (10-50 mg L-1), according to a Doehlert experimental design. The experiments were performed in a glass tubular photochemical reactor of 3.9 L equipped with a concentric low pressure mercury vapor lamp of 36 W. The experimental results indicated that BPA degradation decreases with increasing initial concentration, following pseudo first-order decay, and increases with increasing specific rate of photon emission. The values of the specific BPA degradation rate varied in the range 0.001-0.0066 min-1, while BPA percent degradation at 120 minutes of irradiation varied from 14 to 55%; TOC removal varied from 1.5 to 12.5%. Persistent degradation products were formed, and oxygen reactive species (1O2, oHO) showed to exhibit an important role during BPA degradation. The obtained quantum yield of BPA photolysis was 0.0075 mol BPA mol photons-1, determined from the experimental data through a mathematical model for BPA photolytic degradation versus time. With that aim a treatment system formed by a tubular reactor connected with a mixing tank with recirculation between them was considered; the tubular reactor was treated as a series of three associated continuous perfect mixing reactors (CSTR). Through statistical analysis of the experimental data for two responses (specific BPA degradation rate and BPA percent degradation at 120 minutes), the effects of the variables involved in BPA degradation (initial BPA concentration and specific rate of photon emission) were discussed.
20

Auswirkungen von Östradiol, Bisphenol A und Octylmethoxycinnamat in östrogen-sensitiven Organen im Langzeitversuch an ovarektomierten Mäusen / Effects of estradiol, Bisphenol A and OMC on estrogen sensitive organs of ovarectomized mice under long-term treatment

Opitz, Carl Christian 28 August 2013 (has links)
No description available.

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