618 research outputs found
Gravidezes subseqüentes: quem as tem e quem as quer? Observações em um centro urbano da região Sul do Brasil
Em um estudo de coorte de base populacional, foram estudados todos os 6.011 nascimentos hospitalares ocorridos na cidade de Pelotas, RS, em 1982. As parturientes foram entrevistadas logo após o parto, e 80% delas foram novamente contactadas em suas residências no início de 1986, em média 43 meses mais tarde. Dessas mulheres, 39% haviam engravidado novamente. Esta proporção variou inversamente em relação à idade materna, anos de escolaridade e renda familiar. Quanto à paridade, a proporção de gravidezes subsqüentes foi maior para primíparas e para multíparas. Mães cujos filhos nasceram através de cesareana também apresentaram menor fecundidade, mesmo após exclusão daquelas que, por ocasião da operação cesárea, sofreram ligadura de trompas. Análise através de regressão logística mostrou que esses fatores permaneceram significativamente associados à fecundidade mesmo após o ajuste estatístico para as demais variáveis. Das mães que engravidaram após 1982, 60% informaram que não a desejaram. A proporção das gravidezes indesejadas foi mais elevada em mulheres de maior paridade, sendo esta tendência mais marcada em mulheres de famílias de alta renda.Subsequent pregnancies in mothers of a birth cohort from Pelotas, Southern Brazil, were studied in relation to maternal and socio-economic factors. Within about 3 1/2 years of the cohort child's birth, 39% of mothers had experienced at least one further pregnancy. This proportion decreased with increasing maternal age, years of schooling and family income. A U-shaped trend was observed with respect to parity. Mothers who had delivered the cohort child by caesarean section were also less likely to have another pregnancy within that time. Logistic regression analysis showed that each of these factors remained significantly associated with further pregnancies after controlling for the remaining variables. Analysis of the first subsequent pregnancy showed that a high proportion of mothers had not wanted the pregnancy. Unwanted pregnancies were also significantly associated with older women, low educational status, higher parity and low family income
Causas de mortalidade perinatal em Pelotas, RS (Brasil): utilização de uma classificação simplificada
The causes of perinatal mortality among the 7,392 hospital births which occurred in Pelotas, RS, Brazil, during 1982, were analysed using the simplified classification described by Wigglesworth. The main advantage of this classification is that it can be used even in places where post-mortems are seldom performed. The perinatal deaths were classified into five groups: a) macerated fetuses without malformations, b) congenital malformations, c) immaturity, d) asphyxia and e) other causes of death. The perinatal mortality rate was 33.7 per 1,000 births, nearly equally divided between fetal and early neonatal deaths, and 8.8% of the babies were of low birthweight. Thirty-six percent of the perinatal deaths were antepartum stillbirths, and 60% of these weighed 2,000 g. or more. The second most important cause was immaturity, which accounted for 31% of the deaths. In this latter group 21% weighed 2,000 g or more at birth. These findings, as well as the high birthweight-specific perinatal mortality rates, strongly suggest that there are deficiencies in the antenatal and delivery care in Pelotas that need to be promptly corrected. Policies that should be implemented by health planners include: decentralization of antenatal care clinics; utilization in these clinics of the "at-risk concept" to identify women at high risk of delivering low birthweight babies, efforts to increase community participation and home visits in order to attract those pregnant women who do not attend the clinics. In addition, it is mandatory that well trained doctors (obstetricians and paediatricians) should to be available 24 hours a day at the maternity hospitals to assist mothers and babies identified as at high risk.O coeficiente de mortalidade perinatal dos 7.392 nascimentos ocorridos nos hospitais de Pelotas, RS, (Brasil) no ano de 1982, foi de 33,7 por 1.000, e 8,8% dos recém-nascidos pesaram menos de 2.500 g. As causas de mortalidade perinatal foram analisadas utilizando-se a classificação simplifícada proposta por Wigglesworth. Trinta e seis por cento dos óbitos perinatais ocorreram antes do início do trabalho de parto (natimortos antepartum), e destes, 60% pesaram mais de 2.000 g. A segunda causa mais importante de morte foi imaturidade, com 31% dos óbitos. Neste grupo, 21% pesaram mais de 2.000 g. Estes achados, assim como as altas taxas de mortalidade perinatal para grupos específicos de peso ao nascer, sugerem que algumas falhas estão ocorrendo no atendimento de saúde da população materno-infantil em Pelotas, tanto em clínicas de pré-natal como no atendimento do parto
The Pelotas birth cohort study, Rio Grande do Sul, Brazil, 1982-2001:Estudo de coorte de nascimentos em Pelotas, Rio Grande do Sul, Brasil, 1982-2001
Given the growing recognition of the importance of the life course approach for the determination of chronic diseases, birth cohort studies are becoming increasingly important. This paper describes the methods used in the 1982 Pelotas (Brazil) birth cohort study, one of the largest and longest studies of this type in developing countries. All 5,914 hospital births occurring in Pelotas in 1982 (over 99% of all deliveries) were studied prospectively. The main stages of the study took place in 1983, 1984, 1986, 1995, 1997, 2000, and 2001. More than two thousand variables are available for each subject who participated in all stages of the study. Recent phases of the study included the examination of 2,250 males when presenting for the army recruitment exam in 2000, the study of a 27% sample of men and women in 2001 through household visits, and the study of over 400 children born to the cohort women. Follow-up rates in the recent stages of the cohort were 78.9% for the army examination and 69.0% for the household visits. Ethnographic and oral health studies were conducted in sub-samples. Some recent results on blood pressure, adolescent pregnancy, and asthma are presented as examples of utilization of the data. Suggestions on lessons learned for other cohort studies are proposed
The value of the physical examination in clinical practice: an international survey
A structured online survey was used to establish the views of 2,684 practising clinicians of all ages in multiple countries about the value of the physical examination in the contemporary practice of internal medicine. 70% felt that physical examination was 'almost always valuable' in acute general medical referrals. 66% of trainees felt that they were never observed by a consultant when undertaking physical examination and 31% that consultants never demonstrated their use of the physical examination to them. Auscultation for pulmonary wheezes and crackles were the two signs most likely to be rated as frequently used and useful, with the character of the jugular venous waveform most likely to be rated as -infrequently used and not useful. Physicians in contemporary hospital general medical practice continue to value the contribution of the physical examination to assessment of outpatients and inpatients, but, in the opinion of trainees, teaching and demonstration could be improved
Manganese-coated IRIS to document reducing soil conditions
Iron-coated indicatorof reduction in soils (IRIS) devices have been used for nearly two decades to help assess and document reducing conditions in soils, and official guidance has been approved for interpreting these data. Interest in manganese (Mn)-coated IRIS devices has increased because Mn oxides are reduced under more moderately reducing conditions than iron (Fe) oxides (which require strongly reducing conditions), such that they are expected to be better proxies for some important ecosystem services like denitrification. However, only recently has the necessary technology become available to produce Mn-coated IRIS, and the need is now emerging for guidance in interpreting data derived from Mn IRIS. Ninety-six data sets collected over a 2-yr period from 40 plots at 18 study sites among eight states were used to compare the performance of Mn-coated IRIS with Fe-coated IRIS and to assess the effect of duration of saturation and soil temperature as environmental drivers on the reduction and removal of the oxide coating. It appears that the current threshold prescribed by the National Technical Committee for Hydric Soils for Fe-coated IRIS is appropriate for periods when soil temperatures are warmer (\u3e11 °C), but is unnecessarily conservative when soil temperatures are cooler (5–11 °C). In contrast, Mn-coated devices are particularly useful early in the growing season when soil temperatures are cool. Our data show that when using a threshold of 30% removal of Mn oxide coatings there is essentially 100% confidence of the presence of reducing soil conditions under cool (\u3c11 °C) conditions
Saúde perinatal em Pelotas, RS, Brasil: fatores sociais e biológicos
All hospital births occurring during 1982 in Pelotas, Southern Brazil (pop. 260,000) were studied. This a highly representative perinatal population, since in this city less than 1% of the deliveries occur at home. The study was performed through: hospital interviews with mothers and evaluation of the newborn; home visits of a random sample of 15% of the births after the seventh day of life; and monthly checking of birth and death certificates. Overall, the perinatal mortality rate (PNMR) for singletons was 31.9/1,000 births, fetal mortality rate (FMR) being 16.2/1,000 and early neonatal mortality rate (ENMR) 15.9/1,000. The incidence of low birth weight (LBW) babies was 8.1%. Main causes of death were immaturity, anoxia and hyaline membrane disease. In 40% of the deaths the actual cause was not clarified. Social factors were strongly associated with perinatal health indicators. Babies whose families earned up to 1 minimum wage per month presented a PNMR of 44.0/1,000 and LBW in 12.6% of the cases, whereas those newborns of high income families (more than 10 minimum wages/month) showed a PNMR of 13.2/1,000 and 4.2% of LBW. The association of perinatal performance with maternal age and provenience, birth order and smoking was also studied. When a comparison was made between the perinatal outcome of Pelotas babies with that of a highly developed country (Sweden), using standardization techniques, it was seen that although our birth weight distribution may be held responsible for part of our poor performance, failures in our health services are probably still more important.Todos os nascimentos ocorridos em hospitais na cidade de Pelotas, RS, Brasil, durante 1982, foram estudados através de entrevistas hospitalares e de visitas domiciliares de uma amostra dos recém-nascidos e revisão mensal de atestados de óbito. A mortalidade perinatal para recém-nascidos de partos únicos foi de 31,9/1.000 nascidos totais, sendo a mortalidade fetal de 16,2/1.000 e a mortalidade neonatal precoce de 15,9/1.000. A incidência de baixo peso ao nascer (peso abaixo de 2.500g) foi de 8,1% para partos únicos
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Cloud-Aerosol Transport System (CATS) 1064 nm calibration and validation
The Cloud-Aerosol Transport System (CATS) lidar on board the International Space Station (ISS) operated from 10 February 2015 to 30 October 2017 providing range-resolved vertical backscatter profiles of Earth's atmosphere at 1064 and 532 nm. The CATS instrument design and ISS orbit lead to a higher 1064 nm signal-to-noise ratio than previous space-based lidars, allowing for direct atmospheric calibration of the 1064 nm signals. Nighttime CATS version 3-00 data were calibrated by scaling the measured data to a model of the expected atmospheric backscatter between 22 and 26 km a.m.s.l. (above mean sea level). The CATS atmospheric model is constructed using molecular backscatter profiles derived from Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) reanalysis data and aerosol scattering ratios measured by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP). The nighttime normalization altitude region was chosen to simultaneously minimize aerosol loading and variability within the CATS data frame, which extends from 28 to −2 km a.m.s.l. Daytime CATS version 3-00 data were calibrated through comparisons with nighttime measurements of the layer-integrated attenuated total backscatter (iATB) from strongly scattering, rapidly attenuating opaque cirrus clouds.
The CATS nighttime 1064 nm attenuated total backscatter (ATB) uncertainties for clouds and aerosols are primarily related to the uncertainties in the CATS nighttime calibration technique, which are estimated to be ∼9 %. Median CATS V3-00 1064 nm ATB relative uncertainty at night within cloud and aerosol layers is 7 %, slightly lower than these calibration uncertainty estimates. CATS median daytime 1064 nm ATB relative uncertainty is 21 % in cloud and aerosol layers, similar to the estimated 16 %–18 % uncertainty in the CATS daytime cirrus cloud calibration transfer technique. Coincident daytime comparisons between CATS and the Cloud Physics Lidar (CPL) during the CATS-CALIPSO Airborne Validation Experiment (CCAVE) project show good agreement in mean ATB profiles for clear-air regions. Eight nighttime comparisons between CATS and the PollyXT ground-based lidars also show good agreement in clear-air regions between 3 and 12 km, with CATS having a mean ATB of 19.7 % lower than PollyXT. Agreement between the two instruments (∼7 %) is even better within an aerosol layer. Six-month comparisons of nighttime ATB values between CATS and CALIOP also show that iATB comparisons of opaque cirrus clouds agree to within 19 %. Overall, CATS has demonstrated that direct calibration of the 1064 nm channel is possible from a space-based lidar using the atmospheric normalization technique
Uncovering hidden in vivo resonances using editing based on localized TOCSY
A novel single-shot spectral editing technique for in vivo proton NMR is proposed to recover resonances of low-concentration metabolites obscured by very strong resonances. With this new method, editing is performed by transferring transverse magnetization to J-coupled spins from selected coupling partners using a homonuclear Hartmann-Hahn polarization transfer with adiabatic pulses. The current implementation uses 1D-TOCSY with single-voxel localization based on LASER to recover the H1 proton of beta-glucose at 4.63 ppm from under water and the lactate methyl resonances from beneath a strong lipid signal. The method can be extended to further spin systems where conventional editing methods are difficult to perform
Thermal limits of leaf metabolism across biomes
High-temperature tolerance in plants is important in a warming world, with extreme heat waves predicted to increase in frequency and duration, potentially leading to lethal heating of leaves. Global patterns of high-temperature tolerance are documented in animals, but generally not in plants, limiting our ability to assess risks associated with climate warming. To assess whether there are global patterns in high-temperature tolerance of leaf metabolism, we quantified Tcrit (high temperature where minimal chlorophyll a fluorescence rises rapidly and thus photosystem II is disrupted) and Tmax (temperature where leaf respiration in darkness is maximal, beyond which respiratory function rapidly declines) in upper canopy leaves of 218 plant species spanning seven biomes. Mean site-based Tcrit values ranged from 41.5 °C in the Alaskan arctic to 50.8 °C in lowland tropical rainforests of Peruvian Amazon. For Tmax, the equivalent values were 51.0 and 60.6 °C in the Arctic and Amazon, respectively. Tcrit and Tmax followed similar biogeographic patterns, increasing linearly (˜8 °C) from polar to equatorial regions. Such increases in high-temperature tolerance are much less than expected based on the 20 °C span in high-temperature extremes across the globe. Moreover, with only modest high-temperature tolerance despite high summer temperature extremes, species in mid-latitude (~20-50°) regions have the narrowest thermal safety margins in upper canopy leaves; these regions are at the greatest risk of damage due to extreme heat-wave events, especially under conditions when leaf temperatures are further elevated by a lack of transpirational cooling. Using predicted heat-wave events for 2050 and accounting for possible thermal acclimation of Tcrit and Tmax, we also found that these safety margins could shrink in a warmer world, as rising temperatures are likely to exceed thermal tolerance limits. Thus, increasing numbers of species in many biomes may be at risk as heat-wave events become more severe with climate change
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