ABSTRACT This work addresses the COVID-19 pandemic on two fronts: proposing a system of ordinary differential equations to model it and fitting this model to Brazilian and Portuguese data. It presents estimations to important parameters for the infection dynamics, such as the percentage of asymptomatic individuals, and it stresses out that non-biological human aspects, for example, cultural, social, and economic, are not only impacted by the pandemic but also impact the pandemic dynamics itself. We state that, despite significant variations in the parameters, due to those human elements present in the contemporary pandemic, and despite the strong nonlinearities of the problem, wise human intervention is possible and able to minimize human losses. We show that the mortality rate does not behave as one would expect for a biological problem, independent of cultural aspects, and we also point to possible dates for the peaks of infection in both countries depending on the control of the transmissibility.

We aimed to evaluate knowledge of first aid among new undergraduates and whether it is affected by their chosen course. A questionnaire was developed to assess knowledge of how to activate the Mobile Emergency Attendance Service - MEAS (Serviço de Atendimento Móvel de Urgência; SAMU), recognize a pre-hospital emergency situation and the first aid required for cardiac arrest. The students were also asked about enrolling in a first aid course. Responses were received from 1038 of 1365 (76.04%) new undergraduates. The questionnaires were completed in a 2-week period 1 month after the beginning of classes. Of the 1038 respondents (59.5% studying biological sciences, 11.6% physical sciences, and 28.6% humanities), 58.5% knew how to activate the MEAS/SAMU (54.3% non-biological vs 61.4% biological, P=0.02), with an odds ratio (OR)=1.39 (95%CI=1.07-1.81) regardless of age, sex, origin, having a previous degree or having a relative with cardiac disease. The majority could distinguish emergency from non-emergency situations. When faced with a possible cardiac arrest, 17.7% of the students would perform chest compressions (15.5% non-biological vs 19.1% biological first-year university students, P=0.16) and 65.2% would enroll in a first aid course (51.1% non-biological vs 74.7% biological, P<0.01), with an OR=2.61 (95%CI=1.98-3.44) adjusted for the same confounders. Even though a high percentage of the students recognized emergency situations, a significant proportion did not know the MEAS/SAMU number and only a minority had sufficient basic life support skills to help with cardiac arrest. A significant proportion would not enroll in a first aid course. Biological first-year university students were more prone to enroll in a basic life support course.

As conseqüências da deficiência ou toxidez de micronutrientes na produção agrícola do estado do Rio de Janeiro são pouco conhecidas. Desta forma, em 1997, foram quantificados os teores de cobre, zinco, ferro e manganês em 103 amostras de horizontes superficiais de solos representativos do estado, sendo utilizados os extratores Mehlich-1, DTPA-TEA e HCl 0,1 mol L-1. De maneira geral, o extrator HCl 0,1 mol L-1 foi o que apresentou maior poder de extração dos micronutrientes estudados, tendo o Mehlich-1 extraído as menores quantidades de cobre e ferro e o DTPA-TEA as menores quantidades de zinco e manganês. Segundo os resultados, equações de conversão entre extratores, para um mesmo elemento, e a utilização de faixas de interpretação desenvolvidas para regiões edáficas diferentes das condições do trabalho podem não estimar corretamente a disponibilidade dos micronutrientes às plantas.

The consequences of micronutrient deficiency or toxicity for the agricultural productivity in the state of Rio de Janeiro are not adequately known. For this reason, in 1997, the levels of copper, zinc, iron, and manganese were quantified in 103 samples from surface horizons of representative soils of the state. The extractant solutions used were Mehlich-1, DTPA-TEA, and HCl 0.1 mol L-1. In general, the HCl 0.1 mol L-1 solution extracted the highest amounts of the studied micronutrients. Mehlich-1 extracted the smallest amounts of copper and iron, and the DTPA-TEA extracted the smallest amounts of zinc and manganese. The results showed that the use of linear regression equations for conversion of values amongst methods of a specific element and the use of ranges of interpretation developed in different edaphic conditions, in comparison to the present work, are not recommended. They can lead to incorrect diagnoses.

The United Nations Convention on the Law of the Sea (UNCLOS) - also known as "The Law of the Sea" - defines the important concepts of territorial sea, exclusive economic zone, and continental shelf. Although these terms apply to distinct regions of the sea, there are many misunderstandings and confusion in using the correct name when referring to a particular portion of the ocean. We intend to give the reader some insights about these names and their correct use

A extração da acidez potencial com acetato de cálcio 0,5 mol L-1 é um método amplamente utilizado nos laboratórios de análises de solo no Brasil. Neste trabalho, foram analisadas cento e duas amostras de solos do Estado do Rio de Janeiro, em 1996, visando obter a curva de calibração entre a acidez potencial e o pH de equilíbrio da suspensão de solo com solução-tampão (pH SMP). Os resultados demonstraram que a acidez potencial pode ser estimada por meio da curva de regressão da solução-tampão SMP (R² = 0,90**). Também foi observada correlação significativa entre o pH de equilíbrio da suspensão de acetato de cálcio 0,5 mol L-1 e o pH SMP.

The potential extractable acidity method by Ca(OAc)2 0.5 mol L-1 is widely used in Brazilian soil analysis laboratories. To define the calibration curve between potential extractable acidity and buffered pH SMP, 102 samples of soils from Rio de Janeiro State, Brazil, were analyzed in 1996. The data showed that potential acidity can be estimated by pH SMP buffer suspension (R² = 0.90**) and that the pH of Ca(OAc)2 0.5 mol L-1 suspension was significantly correlated with the pH SMP.

Resumo Um estudo da capacidade física de sete diferentes grupos profissionais residindo na Amazônia brasileira foi realizado. Determinaram-se suas capacidades utilizando-se a bicicleta ergométrica como método. Os grupos profissionais foram os seguintes: militares, trabalhadores rurais, trabalhadores do porto fluvial de Belém, índios Kayapós não civilizados — 10 pessoas de cada. Completaram a série: jogadores profissionais de futebol, sedentários e trabalhadores urbanos — 5 pessoas de cada. Os melhores resultados foram obtidos nos futebolistas e militares. Constituindo um segundo agrupamento, situaram-se os demais, com exceção dos sedentários que se revelaram com a pior condição física, bem abaixo dos restantes. É importante ressaltar que os aniazonidas de uma forma genérica, embora vivendo em ambientes de altas temperaturas e umidades, demonstraram condições físicas comparáveis com habitantes do interior do Estado de São Paulo (cidade de Ribeirão Preto). Os rurícolas, superaram em aptidão física o grupo estudado em São Paulo. Isto talvez se deva às melhores condições de nutrição dos rurícolas da Amazônia (alta ingestão de proteínas e vitaminas). Os índios Kayapós, cujas capacidades físicas foram talvez determinadas pela primeira vez, demonstraram condicionamentos físicos comparáveis com a média da população estudada.

Abstract A study of the physical performance of seven different professional groups living in the Brazilian Amazon was performed. The level of the physical capacity was measured using the ergometric bicycle. The professional groups (10 persons each) were the following: military groups, rural workers, river workers from the fluvial harbor of the city of Belém, primitive Kayapó indians. The other groups were professional soccer players, sedentary working persons and urban workers — 5 people of each. The best physical capacity was obtained by the soccer players and military groups. In second place, having small differences were the remaining groups, except the sedentaries. These persons revealed very low physical performance. As a general generalization the amazonians, although living in an environment of very high temperatures and humidity, are in about the same physical condition as those living in the interior of State of São Paulo (city of Ribeirão Preto). The amazonian rural workers reached better physical condition when compared to those studied in the State of São Paulo. Our preliminary explanation for such a result is the ingestion of a more balanced diet by the amazonians who have mainly high protein intake. The primitive Kayapó indians, perhaps studied for the first time, showed a physical performance comparable with the average of the other workers.