941 resultados para Differences-in-Differences method
Resumo:
Background: Gender differences are expected to influence the pattern and outcome of management of abdominal wall hernias. Some of these are left to speculations with few published articles on hernias in females. Objectives: To describe the clinical pattern of abdominal wall hernias in females. Method: A 5 year retrospective review. Result: There were 181 female patients with 184 hernias representing 27.9% of the total number of hernia patients operated. Mean age was 41.66±24.46 years with a bimodal peak in the 1st and 7th decades. Inguinal hernia accounted for majority (50.5%) but incisional hernia predominated in the 30-49 age group, while only inguinal and umbilical hernias were seen in the first two decades (p=0.04). There was no side predilection in the cases of inguinal hernia. There were 12 (6.6%) emergency presentations, most of which occurred in the 6th decade and above and none below 30 years (p=0.02). Umbilical (4 cases) and femoral hernias (3 cases) accounted for most of these cases. Incisional hernia was the commonest cause of recurrent hernias. Conclusion: Inguinal hernia is the commonest hernia type in females followed by incisional hernias which also accounteds for most recurrent cases. Age appears to be a risk factor for developing complications.
In Situ Characterization of Optical Absorption by Carbonaceous Aerosols: Calibration and Measurement
Resumo:
Light absorption by aerosols has a great impact on climate change. A Photoacoustic spectrometer (PA) coupled with aerosol-based classification techniques represents an in situ method that can quantify the light absorption by aerosols in a real time, yet significant differences have been reported using this method versus filter based methods or the so-called difference method based upon light extinction and light scattering measurements. This dissertation focuses on developing calibration techniques for instruments used in measuring the light absorption cross section, including both particle diameter measurements by the differential mobility analyzer (DMA) and light absorption measurements by PA. Appropriate reference materials were explored for the calibration/validation of both measurements. The light absorption of carbonaceous aerosols was also investigated to provide fundamental understanding to the absorption mechanism. The first topic of interest in this dissertation is the development of calibration nanoparticles. In this study, bionanoparticles were confirmed to be a promising reference material for particle diameter as well as ion-mobility. Experimentally, bionanoparticles demonstrated outstanding homogeneity in mobility compared to currently used calibration particles. A numerical method was developed to calculate the true distribution and to explain the broadening of measured distribution. The high stability of bionanoparticles was also confirmed. For PA measurement, three aerosol with spherical or near spherical shapes were investigated as possible candidates for a reference standard: C60, copper and silver. Comparisons were made between experimental photoacoustic absorption data with Mie theory calculations. This resulted in the identification of C60 particles with a mobility diameter of 150 nm to 400 nm as an absorbing standard at wavelengths of 405 nm and 660 nm. Copper particles with a mobility diameter of 80 nm to 300 nm are also shown to be a promising reference candidate at wavelength of 405 nm. The second topic of this dissertation focuses on the investigation of light absorption by carbonaceous particles using PA. Optical absorption spectra of size and mass selected laboratory generated aerosols consisting of black carbon (BC), BC with non-absorbing coating (ammonium sulfate and sodium chloride) and BC with a weakly absorbing coating (brown carbon derived from humic acid) were measured across the visible to near-IR (500 nm to 840 nm). The manner in which BC mixed with each coating material was investigated. The absorption enhancement of BC was determined to be wavelength dependent. Optical absorption spectra were also taken for size and mass selected smoldering smoke produced from six types of commonly seen wood in a laboratory scale apparatus.
Resumo:
Universidade Estadual de Campinas . Faculdade de Educação Física
Resumo:
A simple method to characterize the micro and mesoporous carbon media is discussed. In this method, the overall adsorption quantity is the sum of capacities of all pores (slit shape is assumed), in each of which the process of adsorption occurs in two sequential steps: the multi-layering followed by pore filling steps. The critical factor in these two steps is the enhancement of the pressure of occluded 'free' molecules in the pore as well as the enhancement of the adsorption layer thickness. Both of these enhancements are due to the overlapping of the potential fields contributed by the two opposite walls. The classical BET and modified Kelvin equations are assumed to be applicable for the two steps mentioned above, with the allowance for the enhanced pore pressure, the enhanced adsorption energy and the enhanced BET constant,all of which vary with pore width. The method is then applied to data of many carbon samples of different sources to derive their respective pore size distributions, which are compared with those obtained from DFT analysis. Similar pore size distributions (PSDs) are observed although our method gives sharper distribution. Furthermore, we use our theory to analyze adsorption data of nitrogen at 77 K and that of benzene at 303 K (ambient temperature). The PSDs derived from these two different probe molecules are similar, with some small differences that could be attributed to the molecular properties, such as the collision diameter. Permeation characteristics of sub-critical fluids are also discussed in this paper. (C) 2001 Elsevier Science B.V. All rights reserved.
Resumo:
Numerical modeling of the eddy currents induced in the human body by the pulsed field gradients in MRI presents a difficult computational problem. It requires an efficient and accurate computational method for high spatial resolution analyses with a relatively low input frequency. In this article, a new technique is described which allows the finite difference time domain (FDTD) method to be efficiently applied over a very large frequency range, including low frequencies. This is not the case in conventional FDTD-based methods. A method of implementing streamline gradients in FDTD is presented, as well as comparative analyses which show that the correct source injection in the FDTD simulation plays a crucial rule in obtaining accurate solutions. In particular, making use of the derivative of the input source waveform is shown to provide distinct benefits in accuracy over direct source injection. In the method, no alterations to the properties of either the source or the transmission media are required. The method is essentially frequency independent and the source injection method has been verified against examples with analytical solutions. Results are presented showing the spatial distribution of gradient-induced electric fields and eddy currents in a complete body model.
Resumo:
Road safety has become an increasing concern in developed countries due to the significant amount of mortal victims and the economic losses derived. Only in 2005 these losses rose to 200.000 million euros, a significant amount - approximately the 2% of its GDP- that easily justifies any public intervention. One tool used by governments to face this challenge is the enactment of stricter policies and regulations. Since drunk driving is one of the most important concerns of public authorities on this field, several European countries decided to lower their illegal Blood Alcohol Content levels to 0.5 mg/ml during the last decade. This study evaluates for the first time the effectiveness of this transition using European panel-based data (CARE) for the period 1991-2003 using the Differences-in-Differences method in a fixed effects estimation that allows for any pattern of correlation (Cluster-Robust). My results show the existence of positive impacts on certain groups of road users and for the whole population when the policy is accompanied by some enforcement interventions. Moreover, a time lag of more than two years is found in that effectiveness. Finally, I also assert the importance of controlling for serial correlation in the evaluation of this kind of policies.
Resumo:
BACKGROUND The concept of achievement is important to study the professional development. In medicine there are gender inequalities in career. The purpose was to know and compare the professional achievement's perceptions and attributions of female and male primary care physicians in Andalusia. METHOD Qualitative study with 12 focus groups (October 2009 to November 2010). POPULATION primary care physicians. SAMPLE intentionally segmented by age, sex and health care management. Were conducted by sex: two groups with young physicians, two groups with middle aged and two with health care management. TOTAL: 32 female physician and 33 male physicians. Qualitative content analysis with Nuddist Vivo. RESULTS Female and male physicians agree to perceive internal achievements and to consider aspects inherent to the profession as external achievements. The most important difference is that female physician related professional achievement with affective bond and male physician with institutional merit. Internal attributions are more important for female physician who also highlight the importance of family, the organization of working time and work-family balance. Patients, continuing education, institutional resources and computer system are the most important attributions for male physician. CONCLUSIONS There are similarities and differences between female and male physicians both in the understanding and the attributions of achievement. The differences are explained by the gender system. The perception of achievement of the female physicians questions the dominant professional culture and incorporates new values in defining achievement. The attributions reflect the unequal impact of family and organizational variables and suggest that the female physicians would be changing gender socialization.
Resumo:
Taidekasvatuksen kaksi kulttuuria, Suomi ja Kanada? Integroitu näkemys Tutkimuksessa kuvataan kanadalaisen Learning Through The Arts –pedagogiikan mukainen suomalainen kokeiluhanke, jonka aikana taiteilija–opettaja-parit opettivat yhdessä eri oppiaineita koululuokille: esim. matematiikkaa tanssien, biologiaa maalaten tai yhdistäen eri taiteenlajeja projektimuotoiseen oppimiseen. Hanketta arvioitaessa nousee esille, ei niinkään yksittäisten taiteilijoiden ja opettajien toiminta, vaan pikemminkin Kanadan ja Suomen rakenteelliset sekä kulttuuriset eroavuudet. Tutkimus sivuaa myös Suomessa käytävää keskustelua taiteen hyödyllisyydestä ja pohtii samalla taito- ja taideaineiden asemaa koulussa. Työn teoreettisessa osassa integroidaan opetussuunnitelmateoriaa, kasvatuksen historiaa ja filosofiaa, tähdentäen taidekasvatuksen merkitystä osana koko ihmisen kasvatusta. Opetussuunnitelmateorian osalta tarkastellaan romanttista ja klassista opetussuunnitelmaa, jotka eroavat toisistaan menetelmiensä, sisältöjensä, tavoitteidensa sekä arvioinnin osalta. Ns. kovat ja pehmeät aineet tai matemaattis-luonnontieteelliset aineet vastakohtanaan humanismi, voidaan ymmärtää sekä historiallisia että epistemologisia taustojaan vasten. Pepperin maailmanhypoteesien mukaisesti on kasvatuksen ongelmien ratkaisemiseksi hahmotettavissa neljä selvästi toisistaan eroavaa lähestymistapaa: formismi; organisismi; mekanisismi; sekä kontekstualismi. Kantin filosofiaan viitaten tutkimus puolustaa käsitystä taiteesta rationaalisena ja propositionaalisena kokonaisuutena, joka ei ole vain kommunikaation väline, vaan yksi todellisuuden kohtaamisen lajeista, tiedon ja etiikan rinnalla. Näin ajateltuna taito- ja taidekasvatuksen tulisi olla luonteeltaan aina myös kulttuurikasvatusta. Tutkimuksen tulosten perusteella voidaan väittää, että moniammatillinen yhteistyö monipuolistaa koulun opetusta. Mikäli huolehditaan siitä, että taiteilijat saavat riittävästi koulutusta opettamiseen liittyvissä asioissa, on mahdollista käyttää taiteilijoita opettajien rinnalla koulutyössä.
Resumo:
Road safety has become an increasing concern in developed countries due to the significant amount of fatalities and the associated economic losses. Only in 2005 these losses rose to 200,000 million euros, a considerable sum ¿ approximately 2% of GDP ¿ that easily justifies any public intervention. One measure taken by governments to address this issue is to enact stricter policies and regulations. Since drunk driving is one of the greatest concerns among public authorities in this field, several European countries have lowered their illegal Blood Alcohol Content (BAC) levels to 0.5 mg/ml during the last decade. This study is the first evaluation of the effectiveness of this transition using European panel-based data (CARE) for the period 1991-2003 with the differences-in-differences method in a fixed effects estimation that allows for any pattern of correlation (Cluster-Robust). The results reveal a positive impact on certain groups of road users and on the whole population when the policy is accompanied by enforcement interventions. Moreover, positive results appeared after a time lag of over two years. Finally, I state the importance of controlling for serial correlation in the evaluation of this type of policy.
Resumo:
Road safety has become an increasing concern in developed countries due to the significant amount of fatalities and the associated economic losses. Only in 2005 these losses rose to 200,000 million euros, a considerable sum ¿ approximately 2% of GDP ¿ that easily justifies any public intervention. One measure taken by governments to address this issue is to enact stricter policies and regulations. Since drunk driving is one of the greatest concerns among public authorities in this field, several European countries have lowered their illegal Blood Alcohol Content (BAC) levels to 0.5 mg/ml during the last decade. This study is the first evaluation of the effectiveness of this transition using European panel-based data (CARE) for the period 1991-2003 with the differences-in-differences method in a fixed effects estimation that allows for any pattern of correlation (Cluster-Robust). The results reveal a positive impact on certain groups of road users and on the whole population when the policy is accompanied by enforcement interventions. Moreover, positive results appeared after a time lag of over two years. Finally, I state the importance of controlling for serial correlation in the evaluation of this type of policy.
Resumo:
Paperin tärkeiden teknisten ominaisuuksien lisäksi myös paperin aistinvaraiset ominaisuudet ovat nousseet merkittäviksi parametreiksi paperia luonnehdittaessa. Aistinvaraisilla ominaisuuksilla tarkoitetaan ominaisuuksia, jotka ihminen aistii käsitellessään tuotetta. Tällaisia ominaisuuksia ovat esimerkiksi paperin karheus, liukkaus, jäykkyys sekä ääni paperia selattaessa. Paperin aistinvaraiset ominaisuudet luovat lukijalle mielikuvan lukemastaan lehdestä lehden sisällön lisäksi. Tämän työn tavoitteena oli kehittää olemassa olevan aistinvaraisten ominaisuuksien arviointiraadin toimintaa. Arviointimenetelmän tilalle pyrittiin löytämään toinen menetelmä sekä kehittämään uusi tulosten raportointimalli. Työssä käytettiin kahta subjektiivista arviointimenetelmää, parivertailua ja ranking-menetelmää. Tuloksia verrattiin aiemmin käytössä olleen referenssimenetelmän tuloksiin. Näytteistä arvioitiin karheus, liukkaus, tahmeus, jäykkyys, selailtavuus, äänen voimakkuus ja äänen laatu. Näiden lisäksi näytteiden miellyttävyyttä arvioitiin parivertailua käyttäen. Arvioitsijoiden yksimielisyyttä selvitettiin parivertailun yhteydessä. Näytteet olivat painamattomia, mutta painokoneen läpi menneitä lehtiformaattiin taitettuja. Visuaalisissa arvioinneissa käytettiin painettuja näytteitä samasta paperivalikoimasta. Arviointimenetelmien tuloksia vertailtaessa, voidaan menetelmien välillä havaita muutamia eroja. Sekä parivertailussa että ranking-menetelmässä näytteet jakaantuivat lähes kokonaan annetulle arviointiskaalalle, kun referenssimenetelmällä ne kasautuivat hyvin pienelle alueelle. Ranking-menetelmässä näytteet jakautuivat vielä laajemmalle kuin parivertailussa. Parivertailu erotteli näytteet paremmin toisistaan kuin referenssimenetelmä. Ranking-menetelmän ja parivertailun välillä vastaavaa eroa erotuskyvyssä ei havaittu. Tulosten perusteella voidaan sanoa, että parivertailu
Resumo:
Introducción: el lupus eritematoso sistémico (LES) es considerado una enfermedad de alto costo. La expresión clínica de la enfermedad depende de la ubicación geografía y la etnicidad. El objetivo de este estudio fue el calcular los costos ambulatorios relacionado al LES en una cohorte colombiana, identificar los predictores de costos y comparar nuestro resultados con otras poblaciones. Métodos: Se realizó una aproximación de tipo prevalencia en 100 pacientes LES en quienes se evaluaron los costos directos médicos, directos no médicos, indirectos e intangibles. Todos los costos médicos fueron evaluados usando una metodología abajo hacia arriba. Los costos directos fueron valorados desde una perspectiva social usando una metodología de micro-costeo. Los costos indirectos se evaluaron mediante una aproximación de capital humano, y los costos intangibles calculados a partir de los años de vida ajustados por calidad (AVAC). Se analizaron los datos por medio de un análisis multivariado. Para comparaciones con otras poblaciones todos los costos fueron expresados como la razón entre los costos y producto interno bruto nacional per cápita. Resultados: La media de costos totales fue 13.031±9.215 USD (ajustados por el factor de conversión de paridad del poder adquisitivo), lo cual representa el 1,66 del PIB per capita de Colombia. Los costos directos son el 64% de los costos totales. Los costos médicos representan el 80% de los costos directos,. Los costos indirectos fueron el 10% y los costos intangibles el 25% de los costos totales. Los medicamentos representaron el 45% de los costos directos. Mayores costos se relacionaron con el estrato socioeconómico, seguro médico privado, AVAC, alopecia, micofenolato mofetilo, y terapia anticoagulante. Los costos directos ajustados de los pacientes con LES en Colombia fueron mayores que en Norte América y en Europa. Conclusiones: el LES impone una carga económica importante para la sociedad. Los costos relacionados con la atención médica y AVAC fueron los principales contribuyentes al alto costo de la enfermedad. Estos resultados pueden ser referencia para determinar políticas en salud pública así como comparar el gasto en salud de forma internacional.
Resumo:
The aim of this study was to develop a fast capillary electrophoresis method for the determination of benzoate and sorbate ions in commercial beverages. In the method development the pH and constituents of the background electrolyte were selected using the effective mobility versus pH curves. As the high resolution obtained experimentally for sorbate and benzoate in the studies presented in the literature is not in agreement with that expected from the ionic mobility values published, a procedure to determine these values was carried out. The salicylate ion was used as the internal standard. The background electrolyte was composed of 25 mmol L(-1) tris(hydroxymethyl)aminomethane and 12.5 mmol L(-1) 2-hydroxyisobutyric acid, atpH 8.1.Separation was conducted in a fused-silica capillary(32 cm total length and 8.5 cm effective length, 50 mu m I.D.), with short-end injection configuration and direct UV detection at 200 nm for benzoate and salicylate and 254 nm for sorbate ions. The run time was only 28 s. A few figures of merit of the proposed method include: good linearity (R(2) > 0.999), limit of detection of 0.9 and 0.3 mg L(-1) for benzoate and sorbate, respectively, inter-day precision better than 2.7% (n =9) and recovery in the range 97.9-105%. Beverage samples were prepared by simple dilution with deionized water (1:11, v/v). Concentrations in the range of 197-401 mg L(-1) for benzoate and 28-144 mg L(-1) for sorbate were found in soft drinks and tea. (c) 2008 Elsevier B.V. All rights reserved.
Resumo:
Introdução: O uso da pressão expiratória positiva na via aérea (EPAP) não é sugerido como técnica de desmame. O EPAP pode previnir o colapso das vias aéreas durante a expiração. Objetivo: O objetivo deste trabalho é verificar se a utilização da pressão expiratória positiva na via aérea (EPAP) apresenta benefícios na redução da hiperinsuflação dinâmica com redução do trabalho respiratório e melhora da oxigenação em pacientes submetidos ao processo de desmame da ventilação mecânica. Material e Métodos: Quarenta pacientes submetidos à ventilação mecânica por um período maior que 48 horas em 2 unidades de terapia intensiva foram avaliados prospectivamente em um estudo randomizado controlado cruzado. Todos os pacientes foram submetidos métodos de ventilação de pressão de suporte (PSV), tubo-t e EPAP, durante 30 minutos, com um período de descanso de 30 minutos entre cada método. Os pacientes foram monitorizados pelo VenTrack (Novametrix, EUA). As variáveis estudadas, mensuradas no minuto 1, 15 e 30, foram: PEEP intínseca (PEEPi), trabalho respiratório (WOBtotal), frequência respiratória (f), volume de ar corrente (Vt) e saturação periférica de oxigênio (SaO2). A amostra geral foi analisada e dividida em subgrupos DPOC (n= 14) e não-DPOC (n=26), traqueostomizados (n=15) e não-traqueostomizados (n=25). As comparações foram feitas pela Análise de Variância (ANOVA) e teste-t. O nível de significância foi de 95%. Resultados: PEEPi DPOC e não-DPOC minuto 1 (0,014 + 0,03 versus 0,17 + 0,38 cmH2O) e minuto 15 (0,042 + 0,13 versus 0,41 + 0,78 cmH2O) (p<0,05). No subgrupo não-traqueo, nos métodos de PSV15 (0,26 + 0,5 cm H2O) e EPAP15 (0,02 + 0,07 cm H2O), assim como PSV 30 (0,21 + 0,4 cm H2O) e EPAP 30 (0,02 + 0,1 cm H2O) (p<0,05). Para traqueo vs não-traqueo, no método EPAP minuto 1 (PEEPi traqueo 0,58 + 0,94 cm H2O; PEEPi não-traqueo 0,08 + 0,28 cmH2O) e minuto 15 (PEEPi traqueo 0,91 + 2,06 cm H2O; PEEPi não-traqueo 0,02 + 0,07 cmH2O) (p<0,05). Em relação ao WOBtotal houve um aumento significativo no método EPAP em relação ao tubo-t na análise geral da amostra (p<0,05). A f mostrou-se maior no método EPAP para o subgrupo não-DPOC e não-traqueo (minutos 1, 15 e 30). A SaO2 foi maior no subgrupo PSV quando comparada com tubo-t na análise geral da amostra, (p<0,05) Conclusões: A EPAP não demonstrou redução na PEEPi na análise geral da amostra, subgrupo DPOC, não-DPOC e traqueostomizados. Houve redução na PEEPi no grupo não-traqueostomizados. Houve aumento do WOBtotal com o uso da EPAP. Neste estudo a EPAP não demonstrou vantagens em relação aos outros métodos.
Resumo:
Este trabalho objetiva verificar o impacto na renda gerado pelo programa de subsídio tarifário para passageiros de transporte intermunicipal da região metropolitana do Estado do Rio de Janeiro (RMRJ), denominado Programa Bilhete Único Intermunicipal (BUI). Para cálculo do impacto foi utilizada a arrecadação do ICMS do comércio varejista como “proxy” da renda. O método para cálculo do impacto foi o de diferença de diferença (DD) para três definições distintas de grupos de tratamento e controle, considerando o período de janeiro de 2006 a janeiro de 2010 como pré-intervenção e fevereiro de 2010 a dezembro de 2014 como pós-intervenção. A primeira definição comparou a evolução de arrecadação do tributo entre os municípios participantes do programa e os municípios fluminenses situados na região limítrofe à RMRJ como grupo de controle. O segundo exercício manteve o mesmo grupo de controle, porém utilizou apenas os municípios sujeitos à intervenção situados a mais de 30 km de distância da capital Rio de Janeiro como grupo de tratamento. Por fim, como teste de robustez, os grupos de tratamento e controle foram selecionados utilizando o método de pareamento (matching). Através de três variações do modelo de DD para cada definição, foi possível encontrar resultados de impacto positivos na arrecadação de ICMS do comércio varejista para os municípios participantes do programa, em especial para os segundo e terceiro exercícios, o que sugere um aumento na renda de seus habitantes após a introdução do Bilhete Único.