32 resultados para Middle years of schooling


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SAOZ (Systeme d'Analyse par Observations Zenithales) is a ground-based UV-Visible zenith-sky spectrometer installed between 1988 and 1995 at a number of NDSC stations at various latitudes on the globe. The instrument is providing ozone and NO2 vertical columns at sunrise and sunset using the Differential Optical Absorption Spectroscopy (DOAS) technique in the visible spectral range. The ERS-2 GOME Ozone Monitoring Experiment (GOME) in 1995 was the first satellite mission to provide a global picture of atmospheric NO 2 with reasonable spatial and temporal resolution. It was then followed by SCanning ImAging spectroMeter for Atmospheric ChartographY (SCIAMACHY) onboard ENVISAT in 2002, and Ozone Monitoring Instrument (OMI) onboard EOS-AURA in 2004, with a similar capacity to monitor total NO 2. All these instruments are nadir viewing mapping spectrometers, applying the DOAS technique in the visible for deriving the NO2 total column. Here we present the results of NO2 long-term comparisons between GOME and SAOZ for the whole period of GOME operation since 1995 at all latitudes - tropics, mid-latitudes and polar regions - in both hemispheres. Comparisons are also shown with the most recently available SCIAMACHY and OMI data in 2004-2005. Overall, the daytime satellite measurements (around noon) are found consistent with sunrise ground-based data, with an average smaller difference at the tropics and mid-latitudes than in the polar areas in the summer. The agreement is even improved after correcting for the NO2 photochemical change between sunrise and the satellite overpass using a box model. However, some seasonal dependence of the difference between ground-based and satellite total NO2 still remains, related to the accuracy of photochemical simulations and the set of NO2 air mass factors used in the retrievals of both systems.

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A study on the presence of herbicides, namely simazine, metribuzin, metolachlor, trifluralin, atrazine and two metabolites, deisopropylatrazine (DIA) and deethylatrazine (DEA), was performed in ground and surface waters from Primavera do Leste region, Mato Grosso state (Middle West of Brazil). The analytical procedure was based on solid-phase extraction (SPE) with Sep-Pak C18 disposable cartridges and ethyl acetate for elution solvent. Residue levels were determined by gas chromatography with nitrogen-phosphorus detection. For most of the pesticides average recoveries at different fortification levels were >with relative standard deviation < The recoveries of DIA and trifluralin in water were 25% and 56%, respectively, which were attributed to the incomplete retention of DIA and strong retention on the sorbing material and high volatility of trifluralin. Detection limits ranged from 0.023 to 0.088 μg L-1. This method was applied for the analysis of 5 superficial water samples and 28 groundwater samples, in places used for human consumption without previous treatment, collected in Primavera do Leste, Mato Grosso, Brazil. Results indicated that the highest level of contamination in a water sample was 1.732 μg L-1 for metolachlor, while metribuzin was the most frequently detected herbicide with maximum concentration of 0.351 μg L-1. ©2006 Sociedade Brasileira de Química.

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Brazil, which has always been in the forefront of sugarcane production, also occupies a prominent position as the first country to produce and use biofuel in its automobile fleet. This fact is a consequence of the introduction of a program which has already turned 30 years, the Próalcool (National Alcohol Program). The oil crisis in the seventies encouraged the government to develop an alternative way to replace gasoline. Bioethanol was then born as fuel obtained from fermentation of sugarcane juice, molasses or both. In the eighties, 85% of the cars ran exclusively on alcohol. Ethanol production in that decade exceeded sugarcane production by the mills. The installed units reached in that period the capacity to produce 18 billion liters of bioethanol per season, a volume equivalent to 100 million barrels of gasoline. The fermentation process, which so far had been restricted to manufacturing sugarcane liquor (aguardente) or ethanol as a byproduct of sugarcane, takes over the spotlight in the entrepreneurial scene. As a result, processes comprising engineering concepts came up and most of the biological phenomena involved in fermentation were understood. The knowledge gathered and the units installed have granted Brazil the hold of production technology and use of a clean fuel.

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Puberty is the fundamental period for bone mass (BM) acquisition. In this period mineralization is found to increase with levels of high bone formation. The critical years of intense bone anabolism deserve special attention, as adequate gain could minimize fracture risk in later years. The objective of this work was to study bone mineral content (BMC) and bone mineral density (BMD) in male adolescents with age bracket and maturation level. Sixty-one healthy male 10 to 19 year-olds were evaluated for calcium intake, weight, stature, BMI, puberty stage and BMC and BMD in the lumbar spine and femur. BM was measured by bone densitometry (DXA). Calcium intake was calculated by recording 3 days diet. Puberty stage was defined as per Tanner. Descriptive statistics was used with means and standard deviations, linear correlation, and analysis of variance for comparison between age groups, and the Tukey test (p<0.05). Linear correlation was positive and indicated body weight as the main correlation variable with BMD in both studied locations (p<0.01). BMC and BMD increased with age, differences were significant from 14 to 15 years, and when adolescents reached Tanner stage G4. These results showed a pronounced increase in bone mineralization, with the years after 14 to 15 being critical for BM acquisition in Brazilian adolescents.

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The main aim of this study was to present evidence of the ways in which different media have conditioned and dramatically reorganized education, in general, and mathematics education, in particular. After an introduction of the theme, we discuss the epistemological perspective that provides the foundation for our analysis: the notion of humans-with-media. Then, we briefly illustrate how the medium is related to the scientific production of mathematical knowledge. We take a detour into the world of art to examine how devices and instruments have historically been associated with the production of mathematical knowledge. Then, we review studies on the history of education to show how traditional media were introduced into schools and have influenced education. In particular, we examine how devices such as blackboards and notebooks, which were novelties a 100 years ago, came to be accepted in schools and the mathematical activities that were promoted with their use. Finally, we discuss how information technology has changed education and how the Internet may have an impact on mathematics education comparable to that of the notebook over a century ago. © FIZ Karlsruhe 2009.

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Aim: The present case report described the use of contact lens of thin porcelain veneers as a restorative therapy to solve anterior teeth disharmony. Background: Fragments of thin veneers are minimally invasive restorations with little or no dental preparation and present thickness ranging from 0.2 to 0.5 mm. They are used in case of diastema closure, small changes of teeth, color and restoration of teeth with small fractures. Case report: A 25-year-old man was admitted at a dental clinic complaining about the diastema presence on the upper anterior teeth. Patient was referred to an orthodontic treatment in order to provide better distribution of the diastemas and harmonious proportion of the teeth. Afterwards, contact lens of thin porcelain veneers were fabricated on the six upper anterior teeth. Conclusion: Based on the outcomes of this clinical report, we considered the use of fragments of thin veneers as a successful treatment option after 3 years of follow-up. Clinical significance: The fragments of thin veneers have been established to be an interesting alternative to esthetically restore the anterior teeth with minimal invasiveness. However, since it is a new treatment modality, longitudinal studies are necessary to understand the material's behavior.

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One of the main purposes of mucogingival therapy is to obtain full root coverage. Several treatment modalities have been developed, but few techniques can provide complete root coverage in a class III Miller recession. Thus, the aim of this case report is to present a successful clinical case of a Miller class III gingival recession in which complete root coverage was obtained by means of a multidisciplinary approach. A 17-year-old Caucasian female was referred for treatment of a gingival recession on the mandibular left central incisor. The following procedures were planned for root coverage in this case: free gingival graft, orthodontic movement by means of alignment and leveling and coronally advanced flap (CAF). The case has been followed up for 12 years and the patient presents no recession, no abnormal probing depth and no bleeding on probing, with a wide attached gingiva band. A compromised tooth with poor prognosis, which would be indicated for extraction, can be treated by orthodontic movement and periodontal therapy, with possibility of 100% root coverage in some class III recessions.

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Some studies have shown differences in specific cognitive ability domains between the sexes at 60 years-of-age. However is important to analyze whether the rate of cognitive decline is also similar between the sexes after this age. The present study examined previously published literature to investigate whether cognitive decline is distinct between men and women after the age of 60 years. A systematic review was carried out with the PubMed, LILACS and PsycINFO databases (2001-2011) using the following search terms: aging, aged, cognitive function, mild cognitive impairment, mental health and cognition. We analyzed longitudinal research that used neuropsychological tests for evaluating cognitive function, showed results separated by sex and that excluded participants with dementia. Elderly women showed better performance in tests of episodic memory, whereas elderly men had a better visuospatial ability. Only one study detected distinct rates of cognitive decline in specific tests between the sexes. Despite differences observed in some domains, most of the studies showed that this rate is similar between the sexes until the age of 80 years. It is unclear whether sex influences the rate of cognitive decline after the age of 80 years. The present review observed that sex does not determine the rate of cognitive decline between 60 and 80 years-of-age. The contextual and cultural factors that involve men and women might determine a distinct decline between them, rather than sex alone. © 2013 Japan Geriatrics Society.

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luoridation of the public water supplies is recognized as among the top ten public health achievements of the twentieth century. However, the positive aspects of this measure depend on the maintenance of fluoride concentrations within adequate levels. Objective: To report the results of seven years of external control of the fluoride (F) concentrations in the public water supply in Bauru, SP, Brazil in an attempt to verify, on the basis of risk/ benefit balance, whether the levels are appropriate. Material and Methods: From March 2004 to February 2011, 60 samples were collected every month from the 19 supply sectors of the city, totaling 4,641 samples. F concentrations in water samples were determined in duplicate, using an ion-speciflc electrode (Orion 9609) coupled to a potentiometer after buffering with TISAB II. After the analysis, the samples were classified according to the best risk-benefit adjustment. Results: Means (±standard deviation) of F concentrations ranged between 0.73±0.06 and 0.81±0.10 mg/L for the different sectors during the seven years. The individual values ranged between 0.03 and 2.63 mg/L. The percentages of the samples considered low risk for dental fluorosis development and of maximum benefit for dental caries prevention (0.55-0.84 mg F/L) in the first, second, third, fourth, fifth, sixth, and seventh years of the study were 82.0, 58.5, 37.4, 61.0, 89.9, 77.3, and 72.4%, respectively, and 69.0% for the entire period. Conclusions: Fluctuations of F levels were found in the public water supply in Bauru during the seven years of evaluation. These results suggest that external monitoring of water fluoridation by an independent assessor should be implemented in cities where there is adjusted fluoridation. This measure should be continued in order to verify that fluoride levels are suitable and, if not, to provide support for the appropriate adjustments.

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Because the agricultural use of tannery sludge may cause increased risks to soils, composting is recognized as one of the most suitable alternative for tannery sludge recycling. Experiments were conducted under field conditions to evaluate the effects of composted tannery sludge (CTS) on the soil microbial biomass and trace elements after two years of consecutive applications. The following five treatments were used: 0 (without CTS application), 5, 10, 20 and 40 ton ha-1 of CTS (dry basis). Soil samples were collected at 60 days after the CTS application at 0-20 cm depth. The CTS application promoted changes in the soil microbial biomass C (SMB-C) and N (SMB-N). In the first year, significant increases in the SMB-C and SMB-N were observed with the application of 10 ton ha-1. Furthermore, CTS application increased the Cr content in the soil after two years of application.

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Agricultural use of tannery sludge (TS) may increase risks to soils. Thus, composting is recognized as one of the most suitable alternatives for TS recycling. Field experiments were carried out to evaluate the effects of composted tannery sludge (CTS) on chromium (Cr), cadmium (Cd), nickel (Ni), and lead (Pb) accumulation in soil after 3 years. Soil samples were collected 60 days after CTS application. After 3 years, The CTS increased Cr and Ni content, while Cd and Pb contents decreased. The third year, Cr contents showed linear increases as CTS rates were applied. The application of CTS, after 3 years, in the 2.5, 5, and 10 Mg ha(-1) increased Cr significantly (140.7%, 159.7%, and 19%, respectively) and Ni (32%, 53%, and 43.8%, respectively) contents in the soil surface layer. This means that consecutive amendments of CTS increase Cr contents in the soil and plants.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)