Germination of piriquiti (Adenanthera pavonina L.) under saline stress conditions / Germinação de piriquiti (Adenanthera pavonina L.) sob condições de estresse salinas

 Adenanthera pavonina L. (Piriquiti) is a pioneer Brazilian forest species belonging to the botanical family Fabaceae of characteristics that make it of important economic interest both for its high timber potential, as for ecology and uses as Ornamental plant. Some factors may be limiting to the germination of plant seeds, especially forest, conditions of salt stress can be one of the factors. The present study aimed to show the germination behavior of A. Pavonina when placed under conditions of saline stress, in different levels of NaCl salt, to point to future studies other possibilities of use for the species. The maximum limiting saline concentration found was 2.0% of sodium chloride, below this concentration does not hear statistical difference in the percentage of germination, however, the increase in the saline concentration up to the maximum limit, negatively affected the Germination velocity, levels above 2.0% were not observed germination. 

Soil evaluation for pineapple cultivation (ananás comosus) in the municipality of Teotônio Vilela, Alagoas / Avaliação do solo para cultivação de abacaxi (ananás comosus) no município de Teotônio Vilela, Alagoas

Soil fertility is one of the crucial factors for agriculture, which has as its main objective the increase of its production. This is why it is extremely important to know the nutritional requirement of the cultivar. The present study aimed to evaluate soil fertility in the municipality of Teotônio Vilela – Alagoas, in the Laudelino farm, emphasizing the quantification of the nutrients needed to guarantee the agricultural productivity for the pineapple crop (Ananás comosus). For this purpose, a random sampling of soil was initiated in the area 1.0 hectare in the layer of 0-20 cm of depth. Fifteen samples were collected (each sample with approximately 0.5 DM ³ of soil) from simple collection were mixed to compose a single composite sample and, from this, 1.0 kg of soil was withdrawn for posterior soil fertility analyses. Carried out in the soil Laboratory of the Agrarian Sciences Center (ECSC) of the Universidade Federal de Alagoas (UFAL) located in the municipality of Rio Largo, AL. We analyzed the potential hydrogenionic (pH), phosphorus (P) and potassium (K +) accessible; Calcium (Ca + 2) and magnesium (Mg + 2) exchangeable; Exchangeable aluminum saturation (m%), CTC cation exchange capacity at pH 7.0 (T); Base sum (V%) and Organic matter (OM). It was observed that the results showed the following values: Ca + 2 contents (3.42 Cmolc/DM ³), CTC (T) (10.73 Cmolc/DM ³); K + (110 mg/DM ³), Mg + 2 (2.53 Cmolc/DM ³), Al + 3 (0.03 Cmolc/DM ³), MO (14.1 g/kg), P (5.0 mg/DM ³), M% (0.0), pH (5.6) and V% (59.0). From the results found, it is concluded that it will not be necessary to apply limestone to increase the base saturation to 60%, because 59% as found in the soil already satimakes nutritional need of the culture in question. In addition to this correction, it is also recommended the dosage of 160 kg of P2O5 and 40 kg of nitrogen (N) per hectare, through the incorporation in the soil of 800 kg/ha in the formulation 05-20-0. However, organic fertilization between 30 and 50 t/ha of curable corral manure, if possible 30 days before planting can elevate redendimento of the cultivar. It is noteworthy that its application is insexpenable to the culture by promoting better development to the plant and the fruit. 

High anti-SARS-CoV-2 antibody seroconversion rates before the second wave in Manaus, Brazil, and the protective effect of social behaviour measures: results from the prospective DETECTCoV-19 cohort

Background: The city of Manaus, Brazil, has seen two collapses of the health system due to the COVID-19 pandemic. We report anti-SARS-CoV-2 nucleocapsid IgG antibody seroconversion rates and associated risk factors in Manaus residents before the second wave of the epidemic in Brazil. Methods: A convenience sample of adult (aged ≥18 years) residents of Manaus was recruited through online and university website advertising into the DETECTCoV-19 study cohort. The current analysis of seroconversion included a subgroup of DETECTCoV-19 participants who had at least two serum sample collections separated by at least 4 weeks between Aug 19 and Oct 2, 2020 (visit 1), and Oct 19 and Nov 27, 2020 (visit 2). Those who reported (or had no data on) having a COVID-19 diagnosis before visit 1, and who were positive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at visit 1 were excluded. Using an in-house ELISA, the reactivity index (RI; calculated as the optical density ratio of the sample to the negative control) for serum anti-SARS-CoV-2 nucleocapsid IgG antibodies was measured at both visits. We calculated the incidence of seroconversion (defined as RI values ≤1·5 at visit 1 and ≥1·5 at visit 2, and a ratio >2 between the visit 2 and visit 1 RI values) during the study period, as well as incidence rate ratios (IRRs) through cluster-corrected and adjusted Poisson regression models to analyse associations between seroconversion and variables related to sociodemographic characteristics, health access, comorbidities, COVID-19 exposure, protective behaviours, and symptoms. Findings: 2496 DETECTCoV-19 cohort participants returned for a follow-up visit between Oct 19 and Nov 27, 2020, of whom 204 reported having COVID-19 before the first visit and 24 had no data regarding previous disease status. 559 participants were seropositive for anti-SARS-CoV-2 nucleocapsid IgG antibodies at baseline. Of the remaining 1709 participants who were seronegative at baseline, 71 did not meet the criteria for seroconversion and were excluded from the analyses. Among the remaining 1638 participants who were seronegative at baseline, 214 showed seroconversion at visit 2. The seroconversion incidence was 13·06% (95% CI 11·52–14·79) overall and 6·78% (5·61–8·10) for symptomatic seroconversion, over a median follow-up period of 57 days (IQR 54–61). 48·1% of seroconversion events were estimated to be asymptomatic. The sample had higher proportions of affluent and higher-educated people than those reported for the Manaus city population. In the fully adjusted and corrected model, risk factors for seroconversion before visit 2 were having a COVID-19 case in the household (IRR 1·49 [95% CI 1·21–1·83]), not wearing a mask during contact with a person with COVID-19 (1·25 [1·09–1·45]), relaxation of physical distancing (1·31 [1·05–1·64]), and having flu-like symptoms (1·79 [1·23–2·59]) or a COVID-19 diagnosis (3·57 [2·27–5·63]) between the first and second visits, whereas working remotely was associated with lower incidence (0·74 [0·56–0·97]). Interpretation: An intense infection transmission period preceded the second wave of COVID-19 in Manaus. Several modifiable behaviours increased the risk of seroconversion, including non-compliance with non-pharmaceutical interventions measures such as not wearing a mask during contact, relaxation of protective measures, and non-remote working. Increased testing in high-transmission areas is needed to provide timely information about ongoing transmission and aid appropriate implementation of transmission mitigation measures. Funding: Ministry of Education, Brazil; Fundação de Amparo à Pesquisa do Estado do Amazonas; Pan American Health Organization (PAHO)/WHO.World Health OrganizationRevisión por pare