Performance of tomato rootstocks in False Root-knot Nematode (Nacobbus aberrans) infested soil

Nacobbus aberrans, known as the "false root-knot nematode", has drawn special attention since it affects large areas of tomato production in Latin America. The aim of this study was to evaluate two rootstocks, Solanum lycopersicon L. var. cerasiforme ´Carolina´ and S. lycopersicon L. ´Maxifort´, onto which S. lycopersicon L. ´Santa Clara´ was grafted. In addition to these, non-grafted ´Santa Clara´ plants were used as control. Grafting was carried out 30 days after sowing, both for scion and for rootstocks. Both the grafted plants and those used as control were grown in a greenhouse on two kind of substrate: without the presence of N. aberrans and inoculated with 5000 eggs. After 60 days of being inoculated, growth parameters, physiological stress indicators, and pathogen reproductive factor were evaluated. The parasitism caused changes in the metabolism of the plants. On grafted plants, f lowering was delayed, and on plants exposed to nematodes such delay was even greater. The reproductive factors of the nematode were 3.68, 5.47 and 2.76 on non-grafted rootstocks, ´Carolina´ and ´Maxifort´, respectively, and they were classified as suscepti ble. The Maxifort rootstock has an invigorating effect on Santa Clara scion. It stimulates the apical growth and shows a great tolerance to the attack of nematodes as indicated by parameters like the accumulation of proline and the damage in the cell membranes. However, N. aberrans reproduces at its roots and increases its population, so its use as rootstocks must be carried out together with other practices that reduce the reproduction factor of the pathogen.Instituto de Fisiología Vegeta

Performance of tomato rootstocks in False Root-knot Nematode (Nacobbus aberrans) infested soil

Nacobbus aberrans, known as the "false root-knot nematode", has drawn special attention since it affects large areas of tomato production in Latin America. The aim of this study was to evaluate two rootstocks, Solanum lycopersicon L. var. cerasiforme ´Carolina´ and S. lycopersicon L. ´Maxifort´, onto which S. lycopersicon L. ´Santa Clara´ was grafted. In addition to these, non-grafted ´Santa Clara´ plants were used as control. Grafting was carried out 30 days after sowing, both for scion and for rootstocks. Both the grafted plants and those used as control were grown in a greenhouse on two kind of substrate: without the presence of N. aberrans and inoculated with 5000 eggs. After 60 days of being inoculated, growth parameters, physiological stress indicators, and pathogen reproductive factor were evaluated. The parasitism caused changes in the metabolism of the plants. On grafted plants, f lowering was delayed, and on plants exposed to nematodes such delay was even greater. The reproductive factors of the nematode were 3.68, 5.47 and 2.76 on non-grafted rootstocks, ´Carolina´ and ´Maxifort´, respectively, and they were classified as suscepti ble. The Maxifort rootstock has an invigorating effect on Santa Clara scion. It stimulates the apical growth and shows a great tolerance to the attack of nematodes as indicated by parameters like the accumulation of proline and the damage in the cell membranes. However, N. aberrans reproduces at its roots and increases its population, so its use as rootstocks must be carried out together with other practices that reduce the reproduction factor of the pathogen.Instituto de Fisiología Vegeta

Performance of tomato rootstocks in False Root-knot Nematode (Nacobbus aberrans) infested soil

Nacobbus aberrans, known as the "false root-knot nematode", has drawn special attention since it affects large areas of tomato production in Latin America. The aim of this study was to evaluate two rootstocks, Solanum lycopersicon L. var. cerasiforme ´Carolina´ and S. lycopersicon L. ´Maxifort´, onto which S. lycopersicon L. ´Santa Clara´ was grafted. In addition to these, non-grafted ´Santa Clara´ plants were used as control. Grafting was carried out 30 days after sowing, both for scion and for rootstocks. Both the grafted plants and those used as control were grown in a greenhouse on two kind of substrate: without the presence of N. aberrans and inoculated with 5000 eggs. After 60 days of being inoculated, growth parameters, physiological stress indicators, and pathogen reproductive factor were evaluated. The parasitism caused changes in the metabolism of the plants. On grafted plants, f lowering was delayed, and on plants exposed to nematodes such delay was even greater. The reproductive factors of the nematode were 3.68, 5.47 and 2.76 on non-grafted rootstocks, ´Carolina´ and ´Maxifort´, respectively, and they were classified as suscepti ble. The Maxifort rootstock has an invigorating effect on Santa Clara scion. It stimulates the apical growth and shows a great tolerance to the attack of nematodes as indicated by parameters like the accumulation of proline and the damage in the cell membranes. However, N. aberrans reproduces at its roots and increases its population, so its use as rootstocks must be carried out together with other practices that reduce the reproduction factor of the pathogen.Fil: Garita, Sebastián Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Fisiología Vegetal. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Fisiología Vegetal; ArgentinaFil: Guimaraes Marcelo

Effect of High vs Low Doses of Chloroquine Diphosphate as Adjunctive Therapy for Patients Hospitalized With Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection: A Randomized Clinical Trial.

There is no specific antiviral therapy recommended for coronavirus disease 2019 (COVID-19). In vitro studies indicate that the antiviral effect of chloroquine diphosphate (CQ) requires a high concentration of the drug.To evaluate the safety and efficacy of 2 CQ dosages in patients with severe COVID-19. This parallel, double-masked, randomized, phase IIb clinical trial with 81 adult patients who were hospitalized with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection was conducted from March 23 to April 5, 2020, at a tertiary care facility in Manaus, Brazilian Amazon. - Patients were allocated to receive high-dosage CQ (ie, 600 mg CQ twice daily for 10 days) or low-dosage CQ (ie, 450 mg twice daily on day 1 and once daily for 4 days). - Label: Main Outcomes and Measures Primary outcome was reduction in lethality by at least 50% in the high-dosage group compared with the low-dosage group. Data presented here refer primarily to safety and lethality outcomes during treatment on day 13. Secondary end points included participant clinical status, laboratory examinations, and electrocardiogram results. Outcomes will be presented to day 28. Viral respiratory secretion RNA detection was performed on days 0 and 4. Out of a predefined sample size of 440 patients, 81 were enrolled (41 [50.6%] to high-dosage group and 40 [49.4%] to low-dosage group). Enrolled patients had a mean (SD) age of 51.1 (13.9) years, and most (60 [75.3%]) were men. Older age (mean [SD] age, 54.7 [13.7] years vs 47.4 [13.3] years) and more heart disease (5 of 28 [17.9%] vs 0) were seen in the high-dose group. Viral RNA was detected in 31 of 40 (77.5%) and 31 of 41 (75.6%) patients in the low-dosage and high-dosage groups, respectively. Lethality until day 13 was 39.0% in the high-dosage group (16 of 41) and 15.0% in the low-dosage group (6 of 40). The high-dosage group presented more instance of QTc interval greater than 500 milliseconds (7 of 37 [18.9%]) compared with the low-dosage group (4 of 36 [11.1%]). Respiratory secretion at day 4 was negative in only 6 of 27 patients (22.2%). - Label: Conclusions and Relevance The preliminary findings of this study suggest that the higher CQ dosage should not be recommended for critically ill patients with COVID-19 because of its potential safety hazards, especially when taken concurrently with azithromycin and oseltamivir. These findings cannot be extrapolated to patients with nonsevere COVID-19

Structure and membrane interactions of the homodimeric antibiotic peptide homotarsinin

Antimicrobial peptides (AMPs) from amphibian skin are valuable template structures to find new treatments against bacterial infections. This work describes for the first time the structure and membrane interactions of a homodimeric AMP. Homotarsinin, which was found in Phyllomedusa tarsius anurans, consists of two identical cystine-linked polypeptide chains each of 24 amino acid residues. The high-resolution structures of the monomeric and dimeric peptides were determined in aqueous buffers. The dimer exhibits a tightly packed coiled coil three-dimensional structure, keeping the hydrophobic residues screened from the aqueous environment. An overall cationic surface of the dimer assures enhanced interactions with negatively charged membranes. An extensive set of biophysical data allowed us to establish structure-function correlations with antimicrobial assays against Gram-positive and Gram-negative bacteria. Although both peptides present considerable antimicrobial activity, the dimer is significantly more effective in both antibacterial and membrane biophysical assays.PMC524437

Estimating the global conservation status of more than 15,000 Amazonian tree species

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt