Abstract FACTORS AFFECTING GINGIVAL EXCESS, ALTERED PASSIVE ERUPTION AND RECESSION IN THE MANDIBULAR ANTERIOR AND PREMOLAR SITES By William F Bohlen, D.M.D. A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Dentistry at Virginia Commonwealth University. Virginia Commonwealth University, 2010 Major Director: Thomas Waldrop, DDS, MS Program director, Department of Periodontics, Virginia Commonwealth University AIM: The aim of this study was to determine the factors affecting gingival excess, altered passive eruption and recession. METHODS: 100 subjects were examined clinically and models of their mandible were fabricated. Demographic, periodontal and cast measurements were recorded for each subject. Measurements were made on casts with digital calipers and included clinical crown length, clinical crown width, papillary height and gingival width. The W:L ratio was calculated and the proportion compared to the maxillary arch ideal of .80. Values greater than .80 were used as a cutoff point for defining gingival excess. Measures of periodontal health were also examined and included probing depths, clinical attachment loss and bleeding on probing. Other patient variables examined were history of orthodontics, presence of occlusal and incisal wear, presence of parafunctional habits, subjective appearance of gummy smile and biotype. RESULTS: The mean W:L ratio was found to be 79.6 %. Tooth type (p<0.001), gender (p<0.0237) and biotype (p<0.0081) were found to significantly contribute to a W:L ratio >.80. There was a significant correlation between the subjective appearance of gingival excess and the W:L ratio, regardless of biotype. There was no association between recession and gingival excess. CONCLUSION: Subjectively, 17% of the study subjects had gingival excess. When the author (WB) made the determination that gingival excess was present, there was a significant increase in the W:L ratio for all teeth, regardless of biotype versus teeth without the presence of gingival excess. Proposed ideal W:L ratios for the mandibular anterior teeth from the second premolar to central incisor are listed in Table 11.

The main purpose of this diploma thesis is the interconnection of three subjects. Change management, people management during changes and economic crisis, which has affected worldwide economics during the years of 2008 to 2010. The methods and tools of change management could be applied to any change concerning an organization. Starting with partial changes, changes in particular processes or departments, concluding with overall, strategic changes, such as company restructuring, reengineering, fusion etc. One type of the changes presents the external changes, such as the economic recession. However, this external change causes many internal changes, where the companies decrease the costs, restructure particular department and change the strategy. In connection with that, the work focuses on the area of people management from the point of the human resources managers as well as executive management. The process of managing changes resulting from the crisis is followed by many changes in the personnel management sector. In this paper are compared three independent researches concerning the reaction of companies to the unfavorable economical situation. All three researches are dated of 2009 and presents the findings of particular reactions of companies in the area of human resources (redundancies, wage...

The understanding of how different parts of a landscape contribute to streamflow by storing and releasing water has long been a central issue in hydrology. Knowledge about what controls streamflow dynamics across landscapes can further our understanding of how catchments store and release water, facilitate predictions for ungauged catchments, and improve the management of water quality and resources. This thesis makes use of data from the Krycklan catchment in northern Sweden. Streamflow data from 14 catchments (0.12 - 68 km2) with variable landscape characteristics such as topography, vegetation, wetland cover, glacial till soils and deeper sediment soils were used to investigate spatial patterns and controls on runoff. The differences in specific discharge (discharge per unit catchment area) between nearby catchments were large at the annual scale, and have the same magnitude as predicted effects of a century of climate change or the observed effects of major forestry operations. This variability is important to consider when studying the effects of climate change and land use changes on streamflow, as well as for our understanding of geochemical mass balances. Streamflow from different catchments was strongly related to landscape characteristics. The distribution of wetland areas had a particularly strong influence, with an annual specific discharge 40-80% higher than catchments with high tree volume on till soils. During drier periods, catchments with deeper sediment soils at the lower elevations of Krycklan had a higher base flow compared to both forested till and wetland catchments. This pattern was reversed at high flows. The storages releasing water to streams in downstream sediment areas were able to maintain base flow for longer periods and were less influenced by evapotranspiration compared to the more superficial till and wetland systems. The results of this thesis have led to a better understanding of the landscape wide patterns of streamflow during different seasons and time scales. The strong associations to landscape characteristics and variable spatial patterns with season and antecedent conditions form the basis for a conceptual understanding of the processes and spatial patterns that shape the heterogeneity of streamflow responses in boreal catchments. / Hur olika delar av landskapet påverkar vattenbalansen och bidrar till avrinning har länge varit en central fråga inom hydrologin. Kunskap om vad som styr avrinningsdynamiken i ett landskap kan öka vår förståelse av hur olika delar av landskapet bidrar till avrinning, hur avrinningsområden lagrar vatten och bildar avrinning, underlätta prognoser för avrinningsområden utan vattenföringsmätningar och förbättra hanteringen av vattenkvaliteten och vattenresurser. Denna avhandling använder data från Krycklans avrinningsområde i norra Sverige. Vattenföringsdata från 14 delavrinningsområden (0.12 - 68 km2) med olika landskapskarakteristik såsom topografi, vegetation och jordarter, användes för att undersöka rumsliga mönster hos avrinningen över olika tidsperioder samt hur landskapet påverkar variabiliteten. Skillnaderna i specifik avrinning (avrinning per areaenhet) mellan närliggande avrinningsområden var stor för årliga värden, och är i samma storleksordning som effekterna av stora skogsavverkningar samt av förutspådda effekter av det kommande seklets förväntade klimatförändringar. Denna variation är viktig att ta hänsyn till när man studerar hur klimatförändringar och ändrad markanvändning påverkar avrinningen, liksom för vår förståelse av geokemiska massbalanser. Avrinning från olika områden var starkt relaterad till deras landskapsegenskaper. Förekomsten av våtmarker hade ett särskilt starkt inflytande. Områden med en stor andel våtmarker hade 40-80% högre årlig specifik avrinning än områden med hög trädvolym på moränjordar. Under torrare perioder hade områden med djupare sedimentjordar hög avrinning jämfört med både områden med skog på morän och med våtmarker. Under höga flöden var detta mönster omvänt. De vattenlager som bidrar till avrinning i sedimentområden kan upprätthålla basflöde under längre tidsperioder och påverkas mindre av evapotranspirationen än de ytligare flödessystemen i morän och våtmarker. Avhandlingen har givit en bättre förståelse av avrinningens rumsliga variation under olika årstider och i olika tidsskalor. Det starka sambandet mellan landskapskarakteristik och avrinningens varierande mönster under olika årstider och lagringsförhållanden utgör en grund för en begreppsmässig förståelse av de processer och rumsliga mönster som skapar heterogeniteten i flödesrespons i boreala områden.

Market economies are not developing smoothly, they succumb to permanent fluctuations of economic activity. Effort of macro-policies is to mitigate or eliminate these fluctuations and support long-term economic growth. Therefore, the aim of this thesis is to analyse the influence of economic policy on causes, course and impact of cyclical development in the Czech Republic in the years 1989-2009. The first section will outline the theoretical background of the economic cycle. I will explain the essence, causes, methodological basis of the business cycle and describe a set of indicators that will help me to analyse fluctuations of economical activity in the practical part. In theoretical part I will also focus on economic policy, especially on the macroeconomic area, but the microeconomical area will be also mentioned. In practical part I will study economic development of the Czech Republic in last twenty years, using the indicators described in the theoretical part. I will evaluate the way of setting the economic policy (suitability of policy mix) in certain economic situations and answer the main question of this thesis: what was the influence of economic policy on economic development of the Czech Republic? Last chapter will be devoted to the business cycle forecasts. I will compare methodical approaches used by forecasting centres such as Ministry of Finance, Czech National Bank and OECD. I will analyse how the previous forecasts of these institutions varied from reality and finally perform a forecast of economic development in the Czech Republic.

A informação sobre a interação entre o rio e aquífero está, cada vez mais, sendo reconhecida como a ponto de entendimento relacionado com a disponibilidade hídrica superficial e a contaminação das águas subterrâneas, além de apresentar influência sobre ambientes hiporreicos. A percepção da importância dessa interação, atraiu o foco de diversos pesquisadores, para o tema. Assim, este trabalho teve como objetivo analisar a interação rio aquífero utilizando um balanço de massa do rio e o gradiente de temperatura entre a água do aquífero e do rio como traçador. Foram utilizados dados de vazão do Ribeirão da Onça, dividido em 3 sub-bacias. Para auxiliar neste monitoramento, foi montado um datalogger alternativo, utilizando a plataforma Arduíno, equipado com um sensor de distância ultrassônico. Também foram utilizadas informações de temperatura da base do ribeirão, como traçador, na sub-bacia 2, através de um termômetro e 4 termopares distribuídos em profundidades a cada 10 cm da base. O datalogger apresentou erro relativo de 3,5% comparado ao transdutor de pressão utilizado. O melhor ajuste para a recessão do escoamento de base foi a quadrática de Boussinesq indicando um coeficiente de recessão (&#945;) menor para a suba-bacia 3 e maior para a sub-bacia 2 . Além disso, o coeficiente de recessão médio para as áreas foi de 0,00388 dia-1, a espessura saturada média da camada saturada, obtida pela formulação quadrática de Boussinesq foi de 51m, e a transmissividade média da bacia foi igual a 131 m2.dia-1. A contribuição de base para as sub-bacias 2 e 3 foram maiores que a da 1, indicando maiores taxas de recarga nas sub-bacias 2 e do 3. A contribuição superficial e linear do escoamento de base para a sub-bacia 2 foi, em média, de 850 mm/d e 4 m3/m.d, respectivamente. A comparação da temperatura da água do aquífero 30 cm abaixo da base do ribeirão, com a temperatura da base do ribeirão, apresentou uma diferença média de 2 &#176;C, além de revelar que a contribuição do aquífero para o ribeirão não foi uniforme, com alguns pontos em que o ribeirão, possivelmente, contribui para o aquífero. A análise dos hidrogramas obtidos através de um balanço de vazão no ribeirão, e a aplicação do gradiente de temperatura, se mostraram alternativas viáveis para o estudo da interação entre o rio e o aquífero. / Information about stream - aquifer interaction is increasly recognized as key to understand process related to surface water avalability, groundwater contamination and its influence on the fauna and flora of hyporeic enviroments. The perception of the importance of this interaction has attracted the focus of several researchers to the theme. Thereby, this work had as objective to analyze the interaction between a river and an aquifer by using both a mass balance and an evaluation of the temperature gradient between the water of the aquifer and the river. Three gaugings stations, installed along the main stream of an upland watershed called Ribeirão da Onça, provided the streamflow data used in this work. To assist in this monitoring, an alternative datalogger was installed, using the Arduino platform, equipped with an ultrasonic distance sensor. Temperature information from the creek base, as a physical tracer, was also used in the intermediaty catchement area, through a thermometer and 4 thermocouples distributed in depths every 10 cm of the river ground. The ultrassonic sensor presented a relative error of 3.5 %, compared to the pressure transducer used. The best fit for the quadratic formulation of Boussinesq indicated that coeficient recession (&#945;) was less for the sub-basin 3 and bigger for subbasin 2. In addition, the mean recession coefficient for the areas was 0.00388 day-1, the mean saturated thickness of the saturated layer, obtained by the quadratic formulation of Boussinesq was 51 m and the mean transmissivity of the basin was equal to 131 m2.day-1. The base contribution to the sub-basins 2 and 3 were bigger than sub-basin 1 showing bigger recharge rates in the sub-basins 2 and 3. The surface and linear contribution of the baseflow to the sub-basin 2 was on average 850 mm/d and 4 m3/m.d, respectively. Comparison of the water temperature of the aquifer 30 cm below the base of the creek with the temperature of the creek base showed an average gradient of 2 &#176;C and also showed that the contribution of the aquifer to the creek is not uniform, with some points where the creek possibly contributes to the aquifer. The intergrated analysis of the hydrographs obtained through a flow balance in the stream and of the temperature gradient have proved to be feasible alternatives for the study of the stream aquifer interaction.

Retalho posicionado coronalmente associado ao enxerto de tecido conjuntivo subepitelial (ETCS) é o padrão ouro para o tratamento de retrações gengivais. A matriz de colágena suína bioabsorvível Mucoderm® (MD) tem sido amplamente utilizada como substituto do ETCS e tem alcançado resultados semelhantes. o MD tem a vantagem de disponibilidade que supera as limitações do sítio doador em enxertos autógenos. O objetivo deste estudo é investigar o uso do MD nos procedimentos de recobrimento radicular combinado com retalho extendido posicionado coronalmente (REPC), grupo teste (GT), em comparação ao ETCS associado ao REPC, grupo controle (GC). Dezoito pacientes adultos, apresentando recessão tipo 1 bilateral foram selecionados. Parâmetros clínicos, profundidade de sondagem, nível clínico de inserção, altura (RG) e largura (LRG) da retração, altura (GQ) e espessura (EGQ) da gengiva queratinizada e área da retração (ARG) foram registrados no início, 3 e 6 meses após os procedimentos cirúrgicos por um examinador cego. Aos 6 meses, um periodontista realizou uma Escala Estética de Recobrimento Radicular (ERR) (Cairo et al. 2009) analisando a posição da margem gengival (MG), contorno do tecido marginal (CTM), textura do tecido mole (TTM), alinhamento da junção mucogengival (AJG) e coloração da gengiva (CG). Aos 3 e 6 meses, um questionário estético funcional para o paciente foi utilizado para avaliar a satisfação com a taxa de recobrimento (STR), coloração da gengiva (CG) e sensibilidade dentinária (SEN), esta última aplicada também no baseline, e se necessário, voltaria a realizar a cirurgia (CIR) em outras áreas. O paciente respondeu ao questionário em uma escala VAS. O GT e o GC apresentaram redução significativa na média da RG (3,33 ± 0,89mm a 1,31 ± 1,03mm (p &lt0,05) e 3,21 ± 0,80mm a 0,83 ± 0,86mm ( p &lt0,05)), LRG (4,03 ± 0,57mm a 2,73 ± 1,62mm 12 e 4,10 ± 0,63mm a 2,07 ± 1,79mm (p &lt0,05)) e ARG (222638 ± 99731pix&sup2 para 72727 ± 82631pix&sup2 e 196461 ± 84815pix&sup2 para 48414 ± 63398pix&sup2 (p &lt0,05)) respectivamente e ganho de GQ (1,87 ± 1,17mm para 2,85 ± 1,43mm (p &lt0,05) e 1,91 ± 0 , 95mm a 2,83 ± 1,41mm (p &lt0,05)) e EGQ (0,76 ± 0,21mm a 1,10 ± 0,31mm (p &lt0,05) e 0,86 ± 0,39mm a 1, 36 ± 0,40mm (p &lt0,05)) respectivamente em um período de 6 meses. A quantidade média de cobertura radicular não foi diferente entre GT (61,33%) e GC (73,90%) (p&gt 0,05). Não houve diferença entre o GC e o GT nos parâmetros analisados no ERR aos 6 meses e para o questionário estético funcional ao paciente houve redução significativa no parâmetro SEN no GT (54,55 ± 32,60% para 19,11 ± 25,73% (p &lt0,05)) e GC (55,61 ± 30,88% a 11,17 ± 17,51% (p &lt0,05)). Ambos os grupos mostraram uma redução significativa na RG. Considerando-se que não foram observadas diferenças significativas entre o GC e o GT para RG, LRG, ARG e GQ e EGQ foram significativamente diferentes favorecendo GT, pode-se especular que o MD possa ser usado como alternativa ao CTG para o tratamento de recessões gengivais / Coronally advanced flap plus connective tissue graft (CTG) is the gold standard therapy for root coverage. The bioabsorbable porcine collagen matrix Mucoderm® (MD) has been widely used in periodontal and mucogingival surgery as a substitute for CTG and has achieved similar results. The MD has the advantage of availability overcoming the limitations of donor site in autograft. The aim of this study is to investigate the use of MD in root coverage procedures combined with extended coronally positioned flap (ECAF), test group (TG) in comparison to the CTG associated with the ECAF, control group (CG). Eighteen adult patients, non-smokers, presenting bilateral Cairo´s Recession Type 1 (RT1) were selected. Clinical parameters, probing depth, clinical attachment level, recession height (RH) and width (RW), keratinized tissue height (KTH) and thickness (KTT) and gingival recession área (GRA) were recorded at baseline,3 and 6 months after the surgical procedures by a blinded examiner. At 6 months a specialist in periodontics performed a Root Coverage Esthetic Score (RES) (Cairo et al. 2009) analyzing position of the gingival margin (GM), marginal tissue contour (MTC), soft tissue texture (STT), mucogingival junction alignment (MJA) and gingival color (GI). At 3 and 6 months a functional aesthetic questionnaire to the patient was used to evaluate the satisfaction with recovering rate (SRR), gingival color (GI) and dentin sensitivity (SEN) (the latter applied initially in the baseline) and, if necessary, would return to perform the surgery (SUR) in other areas. The patient answered the questionnaire on a VAS scale.The TG and CG showed a significant reduction in average for RH (3.33 ± 0.89mm to 1.31±1.03mm (p&lt0.05) and 3.21±0.80mm to 0.83±0.86mm (p&lt0.05)), RW (4.03±0.57mm to 2.73±1.62mm and4.10±0.63mm to 2.07±1.79mm (p&lt0.05)) and GRA (222638±99731pix&sup2 to 72727±82631pix&sup2 and 196461±84815pix&sup2 to 48414±63398pix&sup2 (p&lt0.05)) respectively and gain of KTH (1.87±1.17mm to 2.85±1.43mm (p&lt0.05) and 1.91±0.95mm to 2.83±1.41mm (p&lt0.05)) and KTT 14 (0.76±0.21mm to 1.10±0.31mm (p&lt0.05) and 0.86±0.39mm to 1.36±0.40mm (p&lt0.05)) respectively in a period of 6 month. The average amount of root coverage was not different between TG (61.33%) and CG (73.90%) (p&gt0.05). There was no differences between CG and TG on the parameters analyzed in the RES on 6 months and for the functional aesthetic questionnaire to the patient significant reduction was found on SEN parameter on TG (54.55±32,60% to 19.11±25.73% (p&lt0.05)) and CG (55.61±30.88% to 11.17±17.51% (p&lt 0.05)).In these 6 months follow up study, both groups showed a significant reduction in recession height. Considering no significant differences were observed between CG and TG for RH, RW, GRA and KTH and KTT were significant different favoring TG, it can be speculated that MD can be used as an alternative to CTG for the treatment of gingival recessions

Thesis advisor: Susanto Basu / The Great Recession is arguably the most important macroeconomic event of the last three decades. Prior to the collapse of national output during 2008 and 2009, the United States experienced a sustained period of good economic outcomes with only two mild and short recessions. In addition to the severity of the recession, several characteristics of this recession signify it as as a unique event in the recent economic history of the United States. Some of these unique features include the following: Large Increase in Uncertainty About the Future: The Great Recession and its subsequent slow recovery have been marked by a large increase in uncertainty about the future. Uncertainty, as measured by the VIX index of implied stock market volatility, peaked at the end of 2008 and has remained volatile over the past few years. Many economists and the financial press believe the large increase in uncertainty may have played a role in the Great Recession and subsequent slow recovery. For example, Kocherlakota (2010) states, ``I've been emphasizing uncertainties in the labor market. More generally, I believe that overall uncertainty is a large drag on the economic recovery.'' In addition, Nobel laureate economist Peter Diamond argues, ``What's critical right now is not the functioning of the labor market, but the limits on the demand for labor coming from the great caution on the side of both consumers and firms because of the great uncertainty of what's going to happen next.'' Zero Bound on Nominal Interest Rates: The Federal Reserve plays a key role in offsetting the negative impact of fluctuations in the economy. During normal times, the central bank typically lowers nominal short-term interest rates in response to declines in inflation and output. Since the end of 2008, however, the Federal Reserve has been unable to lower its nominal policy rate due to the zero lower bound on nominal interest rates. Prior to the Great Recession, the Federal Reserve had not encountered the zero lower bound in the modern post-war period. The zero lower bound represents a significant constraint monetary policy's ability to fully stabilize the economy. Unprecedented Use of Forward Guidance: Even though the Federal Reserve remains constrained by the zero lower bound, the monetary authority can still affect the economy through expectations about future nominal policy rates. By providing agents in the economy with forward guidance on the future path of policy rates, monetary policy can stimulate the economy even when current policy rates remain constrained. Throughout the Great Recession and the subsequent recovery, the Federal Reserve provided the economy with explicit statements about the future path of monetary policy. In particular, the central bank has discussed the timing and macroeconomic conditions necessary to begin raising its nominal policy rate. Using this policy tool, the Federal Reserve continues to respond to the state of the economy at the zero lower bound. Large Fiscal Expansion: During the Great Recession, the United States engaged in a very large program of government spending and tax reductions. The massive fiscal expansion was designed to raise national income and help mitigate the severe economic contraction. A common justification for the fiscal expansion is the reduced capacity of the monetary authority to stimulate the economy at the zero lower bound. Many economists argue that the benefits of increasing government spending are significantly higher when the monetary authority is constrained by the zero lower bound. The goal of this dissertation is to better understand how these various elements contributed to the macroeconomic outcomes during and after the Great Recession. In addition to understanding each of the elements above in isolation, a key component of this analysis focuses on the interaction between the above elements. A key unifying theme between all of the elements is the role in monetary policy. In modern models of the macroeconomy, the monetary authority is crucial in determining how a particular economic mechanism affects the macroeconomy. In the first and second chapters, I show that monetary policy plays a key role in offsetting the negative effects of increased uncertainty about the future. My third chapter highlights how assumptions about monetary policy can change the impact of various shocks and policy interventions. For example, suppose the fiscal authority wants to increase national output by increasing government spending. A key calculation in this situation is the fiscal multiplier, which is dollar increase in national income for each dollar of government spending. I show that fiscal multipliers are dramatically affected by the assumptions about monetary policy even if the monetary authority is constrained by the zero lower bound. The unique nature of the elements discussed above makes analyzing their contribution difficult using standard macroeconomic tools. The most popular method for analyzing dynamic, stochastic general equilibrium models of the macroeconomy relies on linearizing the model around its deterministic steady state and examining the local dynamics around that approximation. However, the nature of the unique elements above make it impossible to fully capture dynamics using local linearization methods. For example, the zero lower bound on nominal interest rates often occurs far from the deterministic steady state of the model. Therefore, linearization around the steady state cannot capture the dynamics associated with the zero lower bound. The overall goal of this dissertation is to use and develop tools in computational macroeconomics to help better understand the Great Recession. Each of the chapters outlined below examine at least one of the topics listed above and its impact in explaining the macroeconomics of the Great Recession. In particular, the essays highlight the role of the monetary authority in generating the observed macroeconomic outcomes over the past several years. Can increased uncertainty about the future cause a contraction in output and its components? In joint work with Susanto Basu, my first chapter examines the role of uncertainty shocks in a one-sector, representative-agent, dynamic, stochastic general-equilibrium model. When prices are flexible, uncertainty shocks are not capable of producing business-cycle comovements among key macroeconomic variables. With countercyclical markups through sticky prices, however, uncertainty shocks can generate fluctuations that are consistent with business cycles. Monetary policy usually plays a key role in offsetting the negative impact of uncertainty shocks. If the central bank is constrained by the zero lower bound, then monetary policy can no longer perform its usual stabilizing function and higher uncertainty has even more negative effects on the economy. We calibrate the size of uncertainty shocks using fluctuations in the VIX and find that increased uncertainty about the future may indeed have played a significant role in worsening the Great Recession, which is consistent with statements by policymakers, economists, and the financial press. In sole-authored work, the second chapter continues to explore the interactions between the zero lower bound and increased uncertainty about the future. From a positive perspective, the essay further shows why increased uncertainty about the future can reduce a central bank's ability to stabilize the economy. The inability to offset contractionary shocks at the zero lower bound endogenously generates downside risk for the economy. This increase in risk induces precautionary saving by households, which causes larger contractions in output and inflation and prolongs the zero lower bound episode. The essay also examines the normative implications of uncertainty and shows how monetary policy can attenuate the negative effects of higher uncertainty. When the economy faces significant uncertainty, optimal monetary policy implies further lowering real rates by committing to a higher price-level target. Under optimal policy, the monetary authority accepts higher inflation risk in the future to minimize downside risk when the economy hits the zero lower bound. In the face of large shocks, raising the central bank's inflation target can attenuate much of the downside risk posed by the zero lower bound. In my third chapter, I examine how assumptions about monetary policy affect the economy at the zero lower bound. Even when current policy rates are zero, I argue that assumptions regarding the future conduct of monetary policy are crucial in determining the effects of real fluctuations at the zero lower bound. Under standard Taylor (1993)-type policy rules, government spending multipliers are large, improvements in technology cause large contractions in output, and structural reforms that decrease firm market power are bad for the economy. However, these policy rules imply that the central bank stops responding to the economy at the zero lower bound. This assumption is inconsistent with recent statements and actions by monetary policymakers. If monetary policy endogenously responds to current economic conditions using expectations about future policy, then spending multipliers are much smaller and increases in technology and firm competitiveness remain expansionary. Thus, the model-implied benefits of higher government spending are highly sensitive to the specification of monetary policy. / Thesis (PhD) — Boston College, 2014. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Economics.

Sur l'efficacité des politiques publiques dans une profonde récession. / In this thesis I evaluate the efficiency of public policies in deep recessions. In the first chapter, I look at the impact of government spending in expansions andrecessionswithamodelthatfeaturesafrictionallabormarket. I show that suchfrictionsarenecessarytoreproducetheasymmetriceffectsofgovernment spending over the cycle observed in the data. The model predicts that higher government spending is useful in boosting output in a liquidity trap not because it generates a lot of inflation, but because it is easier to recruit people in a deep recession. The second chapter looks at the policies implemented by H.Hoover in the beginning of the Great Depression (1929-1941). By dampening the contractionary effects of deflation, the policies of high wages carried out by Hoover mitigated the impact of a large negative aggregate demand shock and reduced the likelihood of undergoing a liquidity trap episode. The third chapter studies the impact of government spending policies on private productioninandoutofaliquiditytrap. Incontrastwiththeliterature,partof governmentspendingisassumedtoenterastockofpubliccapitalwhichitself appears in the production function of the private sector. The multiplier effects of government spending are shown to be higher in normal times. In a liquidity trap, the multiplier effects of investing in public capital are an increasing function of the time to build delay and can be significantly higher than the ones coming from standard wasteful government spending. The fourth and last chapter extends this framework to an open economy. It is shown that the presenceofproductivegovernmentspendingcanreproducetheeffectsofgovernment spending on the real exchange rate.

Orientador: Mauro Pedrine Santamaria / Banca: Camila Borges Fernandes / Banca: Maria Aparecida Neves Jardini / Resumo: A retração gengival é um problema altamente prevalente, podendo atingir até 100% dos indivíduos com mais de 50 anos de idade. Para lidar com as recessões, diversas técnicas cirúrgicas foram desenvolvidas. A que apresenta melhores resultados é a técnica de retalho posicionado coronariamente (RPC), feita de forma isolada ou associada ao enxerto de tecido conjuntivo (ETC). No entanto, existem na literatura diversos estudos que demonstram que os pacientes fumantes têm um pior prognóstico no tratamento de recessões gengivais quando comparados aos pacientes não fumantes. Assim, há a necessidade de testar novas abordagens que aumentem a previsibilidade do tratamento das recessões gengivais para esse grupo de pacientes. Portanto, o objetivo do presente estudo foi avaliar influência da terapia com laser de baixa intensidade associado à técnica de enxerto de tecido conjuntivo para recobrimento radicular em pacientes fumantes. Para tal, foi realizado um ensaio clínico duplo cego, controlado, randomizado seguindo as normativas do CONSORT-STATEMENT 2010. Foram selecionados 28 pacientes fumantes apresentando retração gengival que foram divididos nos grupos teste: enxerto de tecido conjuntivo associado à aplicação de laser de baixa intensidade e o grupo controle: enxerto de tecido conjuntivo associado à aplicação SHAM de laser em indivíduos fumantes. Foram avaliadas a taxa de recobrimento, estética e conforto dos pacientes aos, 3 e 6 meses após o procedimento. Encontramos médias de recobrimento parcial de 69% e 70% e de recobrimento total de 22% e 21%, respectivamente para os grupos teste e controle. Não havendo diferenças estatisticamente significantes entre os grupos em nenhum dos parâmetros avaliados. Baseado nos resultados desse estudo pode-se concluir que a aplicação de LBI não aumentou a porcentagem de recobrimento radicular completo e melhora da estética e dor pós-operatoria em pacientes fumantes / Abstract: Gingival recession is a highly prevalent problem and can reach up to 100 % of individuals over 50 years of age. To cope with recessions, various surgical techniques have been developed. As with the best results is the technique of coronally advanced flap (CAF), taken in isolation or associated with connective tissue graft (CTG). However, in the literature there are several studies that show that smokers have a worse prognosis in the treatment of gingival recession compared to non- smokers. Thus there is the need to test new approaches that increase the predictability of the treatment of gingival recession for this group of patients. Therefore, the aim of this study is to evaluate the influence of therapy with lowintensity laser technique associated with connective tissue graft for root coverage in smokers. To do so, double- blind clinical trial, controlled following the regulations of the CONSORT STATEMENT - 2010 will be conducted. We selected 28 patients with gingival recession smokers who were divided into test groups: connective tissue graft associated with the application of low intensity laser and the control group: connective tissue graft associated with laser SHAM application in smokers. The rate of coverage, aesthetics and comfort of patients at 45 days, 2, 3 and 6 months will be evaluated after the procedure We find means of partial coverage of 69% and 70% and total coverage of 22% and 21% respectively for the test and control groups. No statistically significant differences between groups in all evaluated parameters. Based on the results of this study it can be concluded that the application of LILT did not increase the percentage of complete root coverage and improved aesthetics and post-operative pain in smokers / Mestre

Recessão gengival é uma condição caracterizada pelo deslocamento apical da gengiva marginal expondo a superfície radicular, sendo associada a problemas estéticos e funcionais. O objetivo deste estudo foi determinar a prevalência, extensão, gravidade e indicadores de risco para recessão gengival em adultos acima de 35 anos de idade residentes na cidade de Porto Alegre. Este é um estudo observacional transversal de base populacional. Uma amostra representativa de 1023 indivíduos foi selecionada utilizando-se uma amostragem aleatória proporcional de múltiplos-estágios. Os indivíduos responderam a um questionário estruturado e receberam um exame clínico em quatro sítios por dente de todos os dentes presentes. Comandos analíticos que consideram a amostra complexa foram utilizados para gerar estimativas e em modelos de risco multivariados. Recessão ≥1 mm foi um achado universal (99,7% dos indivíduos). O percentual de indivíduos com pelo menos um dente com recessão ≥3 mm, ≥5 mm e ≥7 mm foi 75,4%, 40,7% e 12,5%, respectivamente. Quanto a sua extensão, 67,6%, 27,8%, 9,5% e 2,1% dos dentes por indivíduo mostraram recessão gengival ≥1 mm, ≥3 mm, ≥5 mm e ≥7 mm, respectivamente. Os dentes mais afetados foram incisivos centrais inferiores, segundos pré-molares inferiores e primeiros molares superiores. O avanço da idade, gênero masculino, exposição ao fumo, nível elevado de educação e pior higiene bucal foram indicadores de risco para recessão gengival. Variáveis relativas à higiene bucal não estiveram associadas com recessão gengival vestibular. Pode-se concluir que existe elevada prevalência de recessão gengival na população estudada, estando associada a diferentes fatores comportamentais e sociodemográficos. Diante disto, políticas públicas de saúde são necessárias para agir sobre os fatores etiológicos desta condição e suas consequências. / Gingival recession is a condition characterized by apical displacement of the gingival margin exposing the root surface, associated with aesthetic and functional problems. The aim of this study was to determine the prevalence, extent, severity and risk indicators of gingival recession in adults over 35 years of age living in the city of Porto Alegre. This is an observational cross-sectional population-based study. A representative sample of 1023 individuals was selected using a multistage stratified random sampling. The subjects answered a structured questionnaire and received a clinical examination at four sites per tooth of all teeth present. Analytical commands that consider the complex sample were used to generate estimates and multivariate risk models. Recession ≥ 1 mm was a universal finding (99.7% of subjects). The percentage of subjects with at least one tooth with recession ≥ 3 mm, ≥ 5 mm and ≥ 7 mm was 75.4%, 40.7% and 12.5%, respectively. In regards to extent, 67.6%, 27.8%, 9.5% and 2.1% of teeth per individual showed gingival recession ≥ 1 mm, ≥ 3 mm, ≥ 5 mm and ≥ 7 mm, respectively. The most affected teeth were mandibular central incisors, mandibular second premolars and maxillary first molars. Older age, male gender, smoking exposure, high education and poor oral hygiene were risk indicators for gingival recession. Variables related to oral hygiene were not associated with buccal gingival recession. It can be concluded that there is a high prevalence of gingival recession in this population and it is associated with different sociodemographic and behavioral factors. Given this, public health policies are needed to act on the etiological factors of this condition and its consequences.