Infective endocarditis in intravenous drug abusers: an update

Infective endocarditis despite advances in diagnosis remains a common cause of hospitalization, with high morbidity and mortality rates. Through literature review it is possible to conclude that polymicrobial endocarditis occurs mainly in intravenous drug abusers with predominance in the right side of the heart, often with tricuspid valve involvement. This fact can be associated with the type of drug used by the patients; therefore, knowledge of the patient's history is critical for adjustment of the therapy. It is also important to emphasize that the most common combinations of organisms in polymicrobial infective endocarditis are: Staphylococcus aureus, Streptococcus pneumonia and Pseudomonas aeruginosa, as well as mixed cultures of Candida spp. and bacteria. A better understanding of the epidemiology and associated risk factors are required in order to develop an efficient therapy, although PE studies are difficult to perform due to the rarity of cases and lack of prospective cohorts.This work was supported by Portuguese Foundation for Science and Technology (FCT) through the grants SFRH/BPD/47693/2008, SFRH/BPD/20987/2004 and SFRH/BPD/72632/2010 attributed to Claudia Sousa, Claudia Botelho and Diana Rodrigues, respectively

A Soil Management Assessment Framework (SMAF) Evaluation of Brazilian Sugarcane Expansion on Soil Quality

The Soil Management Assessment Framework (SMAF) was developed to evaluate impacts of land use and management practices on soil quality (SQ), but its suitability for Brazilian tropical soils was unknown. We hypothesized that SMAF would be sensitive enough to detect SQ changes associated with sugarcane (Saccharum officinarum L.) expansion for ethanol production. Field studies were performed at three sites across the south-central region of Brazil, aiming to quantify the impacts of a land use change sequence (i.e., native vegetation–pasture–sugarcane) on SQ. Eight soil indicators were individually scored using SMAF curves developed primarily for North American soils and integrated into an overall Soil Quality Index (SQI) and its chemical, physical, and biological sectors. The SMAF scores were correlated with two other approaches used to assess SQ changes, soil organic C (SOC) stocks and Visual Evaluation of Soil Structure (VESS) scores. Our findings showed that the SMAF was an efficient tool for assessing land use change effects on the SQ of Brazilian tropical soils. The SMAF scoring curves developed using robust algorithms allowed proper assignment of scores for the soil chemical, physical, and biological indicators assessed. The SQI scores were significantly correlated with SOC stocks and VESS scores. Long-term transition from native vegetation to extensive pasture promoted significant decreases in soil chemical, physical, and biological indicators. Overall SQI suggested that soils under native vegetation were functioning at 87% of their potential capacity, while pasture soils were functioning at 70%. Conversions of pasture to sugarcane induced slight improvements in SQ, primarily because of improved soil fertility. Sugarcane soils are functioning at 74% of their potential capacity. Based on this study, management strategies were developed to improve SQ and the sustainability of sugarcane production in Brazil

Tree component influences soil carbon storage and litter decomposition in agrosilvopastoral system.

Integrated farming systems are recognized as agricultural production models that enhance soil carbon storage. This study aimed to evaluate the influence of the tree component on the litter dynamics and soil C and N stocks in an agrosilvopastoral system in the Brazilian Cerrado. We compared nine-years-old agrosilvopastoral system (ASP) with an arrangement of 3x2+14m, with a 24-years-old nominal pasture (NP) and a native vegetation (NV). Five treatments including three sampling points in ASP [between the eucalyptus trees (P1), in the canopy projection area (P2) and in the middle of the alley (P3)], and two areas (PN and VN) were evaluated. Litterfall production from eucalyptus were evaluated in suspended collectors while the decomposition rate was evaluated in litterbags. The assessments were carried out monthly over one year, as well as CO2 fluxes. Soil samples were taken at six soil layers until 0.5m depth to evaluate bulk density, soil fertility and soil C and N stocks. The litterfall production higher in P1, with decrease during the dry season. P1 and P3 showed higher decomposition rates, with final remaining mass of 28.71 and 32.33%. CO2 efflux was higher in the rainy season and showed similar pattern between P1 e NV. Regarding the soil fertility, NV showed higher values of macronutrients and base saturation, and these results can be associated to the nutrient exportation and the deficit of fertilization management in ASP and NP. Soil C and N stocks at 0-50 cm depth were higher in NV (115.4 and 11.3 Mg ha-1), followed by NP (92.4 and 8 .8 Mg ha-1) and ASP (89.9 and 9.0 Mg ha-1). In the sampled points within ASP, soil C and N stocks were higher in P1, showing the influence of tree component. Our results showed that the arrangement as well as the management of eucalyptus trees in the integrated farming system influenced the dynamics of litter decomposition and soil C and N storage over time

Straw removal effects on sugarcane root system and stalk yield.

The sugarcane (Saccharum spp. L.) mechanical harvesting system leaves a large amount of straw mulch on the soil surface. The straw mulch may affect soil conditions, root regrowth, and sugarcane yield. Thus, this study assessed the response of sugarcane root system growth and stalk yield to different rates of straw removal. An experiment was conducted in a Rhodic Kandiudox with sand clay loam texture to test the impact of four rates of straw removal: no removal (18.9 Mg ha−1 of dry mass); moderate removal (8.7 Mg ha−1); high removal (4.2 Mg ha−1) and total removal on sugarcane root system and stalk yield. Higher concentrations of roots (60%) were found in the first 40 cm of soil. Moderate straw removal resulted in higher root mass (3.6 Mg ha−1 ) and stalk production (23 Mg ha−1 of dry mass). However, no straw removal reduced root mass by 20% (105 Mg ha−1). Through regression analysis, it was estimated that retaining between 8.5 and 13 Mg ha−1 of straw resulted in the highest root mass and stalk yield. Managing straw removal to retain a moderate amount enables producers to sustain suitable soil conditions for sugarcane root growth and stalk production while providing straw for industrial use

Maize-Urochloa grass intercropping: an option for improving sustainable agriculture in the Brazilian Savannah.

Intercropping annual cash crops with grasses is a strategy that promotes both diversification and intensification of production in the same area, contributing to sustainable food systems. This study evaluated the impact of intercropping maize with different Urochloa species on maize and subsequent soybean yields over three years in the Brazilian Savannah. The treatments included: (1) maize monoculture; (2) maize intercropped with Urochloa ruziziensis; (3) maize intercropped with U. brizantha cv. Marandu; and (4) maize intercropped with U. brizantha cv. BRS Paiaguás. The evaluations included maize grain yield, land equivalent ratio (LER), forage biomass and soybean yield in succession. The results confirmed that maize intercropped with U. brizantha cv. Marandu and U. brizantha cv. BRS Paiaguás achieved grain yields comparable to monoculture. Demonstrating that these forage species do not significantly compete with maize in 2018 and 2019 in Montividiu and 2018 and 2020 in Rio Verde. In Montividiu, intercropping with U. brizantha cv. BRS Paiaguás resulted in an average LER of 1.13 over three years, highlighting its advantage in optimising land use. In addition, the intercropping system was particularly beneficial in sandy soils, where faster biomass decomposition accelerated improvements in soil structure, moisture retention, and nutrient availability, leading to earlier benefits in soybeans grain yield compared to clay soils. These findings emphasise the potential of maize-forage intercropping to enhance land-use efficiency and soil health while maintaining crop yields in tropical agroecosystems. However, site-specific management is essential to maximise benefits and minimise trade-offs. Future research should focus on long-term soil health dynamics and refining intercropping strategies to improve sustainability in different environmental conditions

Is the expansion of sugarcane over pasturelands a sustainable strategy for Brazil's bioenergy industry?

The authors gratefully thank the São Paulo Research Foundation (FAPESP) (grants # 2014/08632-9 # 2015/14122-6, # 2013/17581-6, # 2014/16612-8 and 2018/09845-7) for the scholarship granted while this research was carried out, and CNPq (grants # 402992/2013-0 and # 311661/2014-9) for the financial support of the present research. Anonymous reviewers are also thanked for their valuable criticisms and comments, which led to substantial improvements of this manuscript.Peer reviewedPostprintPostprin

A soil quality index for subtropical sandy soils under different Eucalyptus harvest residue managements.

Eucalyptus harvest residues are attractive energy production resources for the forestry industry. However, their removal can have adverse impacts on soil quality and forest productivity, especially in sandy soils. In this study, we assessed the effects of Eucalyptus harvest residue managements with variable intensity on forest productivity and on physical, chemical, and biological indicators of the soil quality. The experiment was conducted in a Quartzipsamment (33 g kg− 1 clay) planted with Eucalyptus saligna in Barra do Ribeiro in southern Brazil. Before the Eucalyptus was planted, residues from the previous rotation were subjected to five different management treatments: (1) FRM, in which all forest residues (bark, branches, leaves, and litter) were allowed to remain on the soil and only trunk wood was removed; (2) FRMB, in which was identical to FRM except that bark was also removed; (3) FRMBr, in which only trunk wood and branches were removed; (4) FRR, which involved removing all types of residues (bark, branches, leaves, and litter); and, (5) FRRs, in which all forest residues from the previous rotation were removed, and leaves and branches from the new plantation were prevented from falling onto the soil surface using a shade net. Six years after planting, soil samples were collected at four different depths (0–2.5, 2.5–5, 5–10, and 10–20 cm) to determine 17 soil chemical, physical, and biological indicators. The results were combined into a soil quality index (SQI) using the principal component analysis approach. The SQI reduced by 30%, in the 0–20 cm layer, due to removal of harvest residues from the previous rotation, and collection of litter before it falls on the ground. The main drivers of SQI reduction were the principal components associated with soil organic matter and biological activity. Furthermore, the SQI was positively linearly related to tree height at P < 0.01 and to tree diameter at breast height at P = 0.07. The adverse impact on soil quality and forest productivity in our study indicates that removal of Eucalyptus harvest residues from sandy soils should be avoided

Climate-smart agriculture and soil C sequestration in Brazilian Cerrado: a systematic review.

Climate-smart agriculture (CSA) practices, mainly no-tillage (NT), cover cropping (CC), soil fertilization with organic amendments (OA), and crop-livestock (CL) and crop-livestock-forestry (CLF) systems, has been widely adopted in areas from Brazilian Cerrado. The CSA may partly offset former soil C losses and contribute to climate change mitigation. However, contradictory findings brought uncertainties about the effect of CSA on soil C. Here, by a systematic review of 87 papers and using 621 data pairs, we provided a pervasive biome-scale analysis of soil C stock changes associated with the adoption of CSA across Brazilian Cerrado. All CSA practices evaluated showed average positive rates of C stock change, indicating a general tendency of soil C accretion after its adoption. In areas under NT, CC and CLF, greater rates were estimated for the deeper soil profile evaluated (0.00-1.00 m) (1.24 ± 0.85, 0.54 ± 0.54 and 1.00 ± 1.47 Mg ha?1 yr?1, respectively), while OA and CL showed more soil C accretion when the assessment was limited down to 0.10 m depth (0.82 ± 0.60 and 0.59 ± 0.66 Mg ha?1 yr?1, respectively). Unfortunately, the lack of basic information precluded any attempt to statically compare our estimations. In this sense, we must be cautious in stating that soil C sequestration occurs at those rates after the adoption of CSA practices. Despite these limitations, the results clearly show that the diversification and intensification of agricultural areas in the Cerrado by the adoption of CSA is a promising pathway to increase soil C stocks, and consequently, contribute to climate change mitigation and adaptation. Finally, our findings emphasize the importance of efforts that stimulate farmers to adopt these practices on large scale, such as Brazil?s Low-Carbon Agriculture Plan, besides providing sound empirical evidence about the role of soil C sequestration in Brazil achieving its Nationally Determined Contributions commitments

A Soil Management Assessment Framework (SMAF) Evaluation of Brazilian Sugarcane Expansion on Soil Quality

The Soil Management Assessment Framework (SMAF) was developed to evaluate impacts of land use and management practices on soil quality (SQ), but its suitability for Brazilian tropical soils was unknown. We hypothesized that SMAF would be sensitive enough to detect SQ changes associated with sugarcane (Saccharum officinarum L.) expansion for ethanol production. Field studies were performed at three sites across the south-central region of Brazil, aiming to quantify the impacts of a land use change sequence (i.e., native vegetation–pasture–sugarcane) on SQ. Eight soil indicators were individually scored using SMAF curves developed primarily for North American soils and integrated into an overall Soil Quality Index (SQI) and its chemical, physical, and biological sectors. The SMAF scores were correlated with two other approaches used to assess SQ changes, soil organic C (SOC) stocks and Visual Evaluation of Soil Structure (VESS) scores. Our findings showed that the SMAF was an efficient tool for assessing land use change effects on the SQ of Brazilian tropical soils. The SMAF scoring curves developed using robust algorithms allowed proper assignment of scores for the soil chemical, physical, and biological indicators assessed. The SQI scores were significantly correlated with SOC stocks and VESS scores. Long-term transition from native vegetation to extensive pasture promoted significant decreases in soil chemical, physical, and biological indicators. Overall SQI suggested that soils under native vegetation were functioning at 87% of their potential capacity, while pasture soils were functioning at 70%. Conversions of pasture to sugarcane induced slight improvements in SQ, primarily because of improved soil fertility. Sugarcane soils are functioning at 74% of their potential capacity. Based on this study, management strategies were developed to improve SQ and the sustainability of sugarcane production in Brazil