Agricultural intensification in the tropics is one way to meet rising global food demand in coming decades(1,2). Although this strategy can potentially spare land from conversion to agriculture(3), it relies on large material inputs. Here we quantify one such material cost, the phosphorus fertilizer required to intensify global crop production atop phosphorus-fixing soils and achieve yields similar to productive temperate agriculture. Phosphorus-fixing soils occur mainly in the tropics, and render added phosphorus less available to crops(4,5). We estimate that intensification of the 8-12% of global croplands overlying phosphorus-fixing soils in 2005 would require 1-4 Tg P yr(-1) to overcome phosphorus fixation, equivalent to 8-25% of global inorganic phosphorus fertilizer consumption that year. This imposed phosphorus 'tax' is in addition to phosphorus added to soils and subsequently harvested in crops, and doubles (2-7 Tg P yr(-1)) for scenarios of cropland extent in 2050(6). Our estimates are informed by local-, state- and national-scale investigations in Brazil, where, more than any other tropical country, low-yielding agriculture has been replaced by intensive production. In the 11 major Brazilian agricultural states, the surplus of added inorganic fertilizer phosphorus retained by soils post harvest is strongly correlated with the fraction of cropland overlying phosphorus-fixing soils (r(2) = 0.84, p < 0.001). Our interviews with 49 farmers in the Brazilian state of Mato Grosso, which produces 8% of the world's soybeans mostly on phosphorus-fixing soils, suggest this phosphorus surplus is required even after three decades of high phosphorus inputs. Our findings in Brazil highlight the need for better understanding of long-term soil phosphorus fixation elsewhere in the tropics. Strategies beyond liming, which is currently widespread in Brazil, are needed to reduce phosphorus retention by phosphorus-fixing soils to better manage the Earth's finite phosphate rock supplies and move towards more sustainable agricultural production.

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Invasive cervical cancer disproportionately affects women without sufficient access to care, with higher rates among minority groups in higher-income countries and women in low-resource regions of the world. Many elements contribute to racial/ethnic disparities in the cervical cancer continuum - from screening and diagnosis to treatment and outcome. Sociodemographic factors, access to healthcare, income and education level, and disease stage at diagnosis are closely linked to such inequities. Despite the identification of such elements, racial/ethnic disparities persist, and are widening in several minority subgroups, particularly in older women, who are ineligible for human papillomavirus (HPV) vaccination and are underscreened. Recent studies suggest that racial/ethnic differences in HPV infection exist and may also have a role in observed differences in cervical cancer. In this review, we provide an overview of the current literature on racial disparities in cervical cancer screening, incidence, treatment and outcome to inform future strategies to reduce persistent inequities.

The aim of this study was to evaluate the performance of the Centers for Dental Specialties (CDS) in the country and associations with sociodemographic indicators of the municipalities, structural variables of services and primary health care organization in the years 2004-2009. The study used secondary data from procedures performed in the CDS to the specialties of periodontics, endodontics, surgery and primary care. Bivariate analysis by χ2 test was used to test the association between the dependent variable (performance of the CDS) with the independents. Then, Poisson regression analysis was performed. With regard to the overall achievement of targets, it was observed that the majority of CDS (69.25%) performance was considered poor/regular. The independent factors associated with poor/regular performance of CDS were: municipalities belonging to the Northeast, South and Southeast regions, with lower Human Development Index (HDI), lower population density, and reduced time to deployment. HDI and population density are important for the performance of the CDS in Brazil. Similarly, the peculiarities related to less populated areas as well as regional location and time of service implementation CDS should be taken into account in the planning of these services.

Objective: To evaluate the association of breastfeeding duration, pacifier use and nasal air flow with occlusal disorders among children. Methods: This cross-sectional observational study included 138 children aged 4 and 5 years selected in all the daycare centers of the city of Campo Limpo Paulista, Brazil. Questionnaires were applied to mothers to identify total duration of exclusive breastfeeding and non-nutritive sucking. The independent variables were: Sucking (pacifier, bottle, finger), breastfeeding duration and nasal air flow. The dependent variables were: Open bite, crossbite, overjet, overbite, diastema and maxillary deficiency. Frequency distribution calculations were performed, a chi-square test, the Fisher exact test and, after that, stepwise logistic regression were used for statistical analysis, and the level of significance was set at 5%. Results: The use of a pacifier was the most deleterious factor and increased chances of having open bite in 33.3 times, marked overjet in 2.77 times and posterior crossbite in 5.26 times. Conclusion: There was a significant association between non-nutritive sucking, particularly the use of a pacifier, and occlusal disorders. These findings are important to plan the treatment of preschoolers.Keywords: Breastfeeding. Malocclusion. Primary dentition. Objetivo: avaliar a associação do tempo de amamentação natural, tempo de uso de chupeta e aeração nasal em relação a problemas oclusais em crianças. Métodos: foi realizado um estudo observacional transversal com universo de 138 crianças entre 4 e 5 anos, de creches de Campo Limpo Paulista/SP. Foram aplicados questionários às mães com o intuito de identificar o tempo de amamentação natural total e exclusiva e hábitos deletérios. Utilizaram-se as variáveis independentes hábitos deletérios (chupeta, mamadeira e dedo), tempo de amamentação natural e aeração nasal; e as variáveis dependentes mordida aberta, mordida cruzada, overjet, sobremordida, presença de diastema e atresia. Foram realizados cálculos das distribuições das frequências, teste de associação do qui-quadrado, exato de Fisher e, em seguida, regressão logística pelo método de stepwise, utilizando nível de significância de 5%. Resultados: o uso de chupeta foi considerado o mais prejudicial dos hábitos deletérios, aumentando em 33,3 vezes a chance de mordida aberta; 2,77 vezes a chance de apresentar overjet acentuado e 5,26 vezes as chances de apresentar mordida cruzada posterior. Conclusão: houve uma forte associação entre hábitos deletérios (especialmente o tempo de uso de chupeta) e problemas oclusais, sendo esse fato importante no planejamento do tratamento de pacientes pré-escolares.Palavras-chave: Aleitamento materno. Má oclusão. Hábitos. Dentição decídua.

Mobile screening units (MSUs) provide cancer screening services outside of fixed clinical sites, thereby increasing access to early detection services. We conducted a systematic review of the performance of MSUs for the early detection of cancer. Databases (MEDLINE, EMBASE, Cochrane Library, WHO Global Health Library, Web of Science, PsycINFO) were searched up to July 2015. Studies describing screening for breast, cervical, and colon cancer using MSUs were included. Data were collected for operational aspects including the performance of exams, screening tests used, and outcomes of case detection. Of 268 identified studies, 78 were included. Studies investigated screening for cancers including breast ( = 55), cervical ( = 12), colon ( = 1), and multiphasic screening for multiple cancers ( = 10). The median number of screening exams performed per intervention was 1,767 (interquartile range 5,656-38,233). Programs operated in 20 countries, mostly in North America (36%) and Europe (36%); 52% served mixed rural/urban regions, while 35% and 13% served rural or urban regions, respectfully. We conclude that MSUs have served to expand access to screening in diverse contexts. However, further research on the implementation of MSUs in low-resource settings and health economic research on cost-effectiveness of MSUs compared with fixed clinics to inform policymakers is needed. .

BackgroundInvestigate the individual and contextual variables related to caries in underprivileged adolescents, and the disparity in distribution of the disease.MethodsCross-sectional analytical study, conducted in the city of Piracicaba, SP, Brazil, in 2012. The probabilistic sample was composed of 1,179 adolescents from 15–19 years of age, randomly selected from 21 state schools and 34 Primary Health Units – Family Health (PHU-FH). The dependent variables studied were number of decayed teeth and caries experience (DMFT). The independent variables were classified into individual (clinical, sociodemographic, psychosocial, self-perception, impact on oral health, access to services, and quality of life) and contextual (social exclusion index, total number of residents in suburb, literacy rate, and the following variables given in percentages: residences in the home ownership category, provision of domestic sewerage, trash collection, families with income of over 1 minimum wage per month, and families without monthly income) variables. The multilevel regression model was estimated by the PROC GLIMMIX (Generalized Linear Models-Mixed) procedure, considering the individual variables as Level 1 and the contextual variables of the suburbs as Level 2. Adjustment of the model was evaluated by -2 Res Log Likelihood with α = 0.05.ResultsAs regards the individual variables, adolescents who declared having a prison inmate in the Family and resided in homes with a larger number of persons, showed a higher number of decayed teeth. There were a larger number of decayed teeth, a higher DMFT value, and worse self-perception as regards the health of their teeth and mouth. Other variables, such as being of the female gender, age and time since last visit to the dentist were related to the DMFT index. As regards the contextual variables, the DMFT was lower in suburbs with greater access to domestic sewage, and the number of decayed teeth was higher in suburbs with the worst social exclusion indices.ConclusionIndividual and contextual variables were associated with the presence of caries and DMFT index in underprivileged adolescents, indicating that they must be taken into consideration in the formulation of policies directed towards oral health promotion and prevention activities in this group.

BackgroundThe objective of this study was to compare the socioeconomic and family characteristics of underprivileged schoolchildren with and without curative dental needs participating in a dental health program.MethodsA random sample of 1411 of 8-to-10 year-old Brazilian schoolchildren was examined and two sample groups were included in the cross-sectional study: 544 presented curative dental needs and the other 867 schoolchildren were without curative dental needs. The schoolchildren were examined for the presence of caries lesions using the DMFT index and their parents were asked to answer questions about socioenvironmental characteristics of their families. Logistic regression models were adjusted estimating the Odds Ratios (OR), their 95% confidence intervals (CI), and significance levels.ResultsAfter adjusting for potential confounders, it was found that families earning more than one Brazilian minimum wage, having fewer than four residents in the house, families living in homes owned by them, and children living with both biological parents were protective factors for the presence of dental caries, and consequently, curative dental needs.ConclusionsSocioeconomic status and family structure influences the curative dental needs of children from underprivileged communities. In this sense, dental health programs should plan and implement strategic efforts to reduce inequities in oral health status and access to oral health services of vulnerable schoolchildren and their families.