Soil Carbon in Agroforestry Systems: An Unexplored Treasure?

Soil organic matter (SOM), which contains more reactive organic carbon (C) than any other single terrestrial pool, plays a major role in determining C storage in ecosystems and regulating atmospheric concentrations of carbon dioxide (CO2)^1^. Agroforestry, the practice of growing trees and crops in interacting combinations on the same unit of land^2^, primarily by resource-poor smallholder farmers in developing countries, is recognized as a strategy for soil carbon sequestration (SCS) under the Clean Development Mechanism (CDM) of the Kyoto Protocol^3^. The understanding about C storage and dynamics under agroforestry systems (AFS), however, is minimal. Our studies under various AFS in diverse ecological conditions in five countries showed that tree-based agricultural systems, compared to treeless systems, stored more C in deeper soil layers up to 1 m depth under comparable conditions. More C is stored in soil near the tree than away from the tree; higher SOC content is associated with higher species richness and tree density; and C3 plants (trees) contribute to more C in the silt- + clay-sized (<53 µm) fractions that constitute more stable C, than C4 plants, in deeper soil profiles4 - 8. These results provide clear indications of the possibilities for climate change mitigation through SCS in AFS, and opportunities for economic benefit - through carbon trading - to millions of smallholder farmers in developing countries

Towards the creation of decellularized organ constructs using irreversible electroporation and active mechanical perfusion

<p>Abstract</p> <p>Background</p> <p>Despite advances in transplant surgery and general medicine, the number of patients awaiting transplant organs continues to grow, while the supply of organs does not. This work outlines a method of organ decellularization using non-thermal irreversible electroporation (N-TIRE) which, in combination with reseeding, may help supplement the supply of organs for transplant.</p> <p>Methods</p> <p>In our study, brief but intense electric pulses were applied to porcine livers while under active low temperature cardio-emulation perfusion. Histological analysis and lesion measurements were used to determine the effects of the pulses in decellularizing the livers as a first step towards the development of extracellular scaffolds that may be used with stem cell reseeding. A dynamic conductivity numerical model was developed to simulate the treatment parameters used and determine an irreversible electroporation threshold.</p> <p>Results</p> <p>Ninety-nine individual 1000 V/cm 100-μs square pulses with repetition rates between 0.25 and 4 Hz were found to produce a lesion within 24 hours post-treatment. The livers maintained intact bile ducts and vascular structures while demonstrating hepatocytic cord disruption and cell delamination from cord basal laminae after 24 hours of perfusion. A numerical model found an electric field threshold of 423 V/cm under specific experimental conditions, which may be used in the future to plan treatments for the decellularization of entire organs. Analysis of the pulse repetition rate shows that the largest treated area and the lowest interstitial density score was achieved for a pulse frequency of 1 Hz. After 24 hours of perfusion, a maximum density score reduction of 58.5 percent had been achieved.</p> <p>Conclusions</p> <p>This method is the first effort towards creating decellularized tissue scaffolds that could be used for organ transplantation using N-TIRE. In addition, it provides a versatile platform to study the effects of pulse parameters such as pulse length, repetition rate, and field strength on whole organ structures.</p

Analysis of the evolution of Xe-135 in a KWU-PWR reactor using coupled codes

[EN] The fission product Xe-135 has a tremendous impact on the operation of the nuclear reactor and may interfere with the plant's operational capacity. Therefore, the incorporation of Flexible Operation (non baseload) in nuclear power plants requires studies that assess the effect of Xenon oscillations in power production taking into account the requirements of the electrical network as well as the nuclear safety. To analyze the evolution of the neutronic poison Xe-135, a 3D thermal-hydraulic-neutronic model of the core of a pressurized water nuclear reactor (PWR), with three cooling loops and German Siemens-KWU technology, was developed with the coupled code RELAP5/PARCSv3.2. The model was carried out from the real information of the core state and taking into account the data referring to the position of the Incore detectors of the studied plant. After validating the 3D thermal-hydraulic-neutronic RELAP5/PARCSv3.2 model, an operational transient of the PWR-KWU reactor is carried out in non-baseload operation. The results verified that the modeling provides good accuracy in predicting the trend of Xenon oscillation behavior. Furthermore, Xenon oscillations in the reactor core are dampened in the same way although the control bank insertion is executed at different ramp rates. The final goal is to use this model in order to define a strategy to move the control rod banks when there is a requirement to decrease the power in the reactor core.The authors would like to acknowledge the economic support provided by CNAT for the realization of this work and express their great appreciation to CNAT and IBERDROLA for sharing the data needed to develop this work.Navarro, B.; Barrachina, T.; Miró Herrero, R.; Verdú Martín, GJ.; Garcia-Fenoll, M.; Posada, JM. (2021). Analysis of the evolution of Xe-135 in a KWU-PWR reactor using coupled codes. European Nuclear Society. 1-10. http://hdl.handle.net/10251/19108711

Oxygen abundances in unevolved metal-poor stars from near-UV OH lines

We have performed a detailed oxygen abundance analysis of 23 metal-poor (-3.0<[Fe/H]<-0.3) unevolved halo stars and one giant through the OH bands in the near UV, using high-resolution echelle spectra. Oxygen is found to be overabundant with respect to iron in these stars, with the [O/Fe] ratio increasing from 0.6 to 1 between [Fe/H]=-1.5 and -3.0. The behavior of the oxygen overabundance with respect to [Fe/H] is similar to that seen in previous works based on OI IR triplet data (Abia and Rebolo 1989; Tomkin et al. 1992; Cavallo, Pilachowski, and Rebolo 1997). Contrary to the previously accepted picture, our oxygen abundances, derived from low-excitation OH lines, agree well with those derived from high-excitation lines of the triplet. For nine stars in common with Tomkin et al. we obtain a mean difference of 0.00+/-0.11 dex with respect to the abundances determined from the triplet using the same stellar parameters and model photospheres. For four stars in our sample we have found measurements of the [OI] 6300 A line in the literature, from which we derive oxygen abundances consistent (average difference 0.09 dex) with those based on OH lines, showing that the long standing controversy between oxygen abundances from forbidden and permitted lines in metal-poor unevolved stars can be resolved. Our new oxygen abundances show a smooth extension of the Edvardsson et al.'s (1993) [O/Fe] versus metallicity curve to much lower abundances, with a slope -0.31+/- 0.11 (taking into account the error bars in both oxygen abundances and metallicities) in the range -3<[Fe/H]<-1.Comment: 17 pages, 8 figures, 3 table

Boron in Very Metal-Poor Stars

We have observed the B I 2497 A line to derive the boron abundances of two very metal-poor stars selected to help in tracing the origin and evolution of this element in the early Galaxy: BD +23 3130 and HD 84937. The observations were conducted using the Goddard High Resolution Spectrograph on board the Hubble Space Telescope. A very detailed abundance analysis via spectral synthesis has been carried out for these two stars, as well as for two other metal-poor objects with published spectra, using both Kurucz and OSMARCS model photospheres, and taking into account consistently the NLTE effects on the line formation. We have also re-assessed all published boron abundances of old disk and halo unevolved stars. Our analysis shows that the combination of high effective temperature (Teff > 6000 K, for which boron is mainly ionized) and low metallicity ([Fe/H]<-1) makes it difficult to obtain accurate estimates of boron abundances from the B I 2497 A line. This is the case of HD 84937 and three other published objects (including two stars with [Fe/H] ~ -3), for which only upper limits can be established. BD +23 3130, with [Fe/H] ~ -2.9 and logN(B)_NLTE=0.05+/-0.30, appears then as the most metal-poor star for which a firm measurement of the boron abundance presently exists. The evolution of the boron abundance with metallicity that emerges from the seven remaining stars with Teff < 6000 K and [Fe/H]<-1, for which beryllium abundances were derived using the same stellar parameters, shows a linear increase with a slope ~ 1. Furthermore, the B/Be ratio found is constant at a value ~ 20 for stars in the range -3<[Fe/H]<-1. These results point to spallation reactions of ambient protons and alpha particles with energetic particles enriched in CNO as the origin of boron and beryllium in halo stars.Comment: 38 pages, 11 Encapsulated Postscript figures (included), uses aaspp4.sty. Accepted for publication in The Astrophysical Journal. The preprint is also available at: http://www.iac.es/publicaciones/preprints.htm

The atorvastatin metabolic phenotype shift is influenced by interaction of drug-transporter polymorphisms in Mexican population: results of a randomized trial

Atorvastatin (ATV) is a blood cholesterol-lowering drug used to prevent cardiovascular events, the leading cause of death worldwide. As pharmacokinetics, metabolism and response vary among individuals, we wanted to determine the most reliable metabolic ATV phenotypes and identify novel and preponderant genetic markers that affect ATV plasma levels. A controlled, randomized, crossover, single-blind, three-treatment, three-period, and six-sequence clinical study of ATV (single 80-mg oral dose) was conducted among 60 healthy Mexican men. ATV plasma levels were measured using high-performance liquid chromatography mass spectrometry. Genotyping was performed by real-time PCR with TaqMan probes. Four ATV metabolizer phenotypes were found: slow, intermediate, normal and fast. Six gene polymorphisms, SLCO1B1-rs4149056, ABCB1-rs1045642, CYP2D6-rs1135840, CYP2B6-rs3745274, NAT2-rs1208, and COMT- rs4680, had a significant effect on ATV pharmacokinetics (P < 0.05). The polymorphisms in SLCO1B1 and ABCB1 seemed to have a greater effect and were especially important for the shift from an intermediate to a normal metabolizer. This is the first study that demonstrates how the interaction of genetic variants affect metabolic phenotyping and improves understanding of how SLCO1B1 and ABCB1 variants that affect statin metabolism may partially explain the variability in drug response. Notwithstanding, the influence of other genetic and non-genetic factors is not ruled out.Fil: León Cachón, Rafael B. R.. Universidad de Monterrey.; MéxicoFil: Bamford, Aileen Diane. Universidad de Monterrey.; MéxicoFil: Meester, Irene. Universidad de Monterrey.; MéxicoFil: Barrera Saldaña, Hugo Alberto. Vitagenesis S.A.; México. Innbiogem S.C.; MéxicoFil: Gómez Silva, Magdalena. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Garcia Bustos, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; Argentin

TROPAS E TROPEIROS EM SOROCABA: A IMPORTÂNCIA DOS MUARES NA PRODUÇÃO DE UM ESPAÇO

This article fosters the comprehension of the period in which the “tropeirismo” (cattle dealing) was taken by the members of society in Sorocaba as an economically productive activity, due to the start of the cattle market held in the city every year. A considerable amount of animals was brought to the market, especially the “muar” (most commercialized breed), which was considered the most important means of transport in the country until the end of the 19th century, when the first national railways were built. Traders from different parts of Brazil were interested in the activity, which was leading the country to an optimization of urban activities, such as manufacturing, industry and commerce. So, the Sorocaba area was formed in a very particular way, differently from places where agriculture played a crucial role for general development.Este trabalho tem por objetivo compreender o período em que o tropeirismo é tomado pela sociedade sorocabana como uma atividade economicamente produtiva, possibilitada pelo surgimento da feira de muares realizada anualmente na cidade. Sorocaba recebia um número expressivo de gado, destacando o muar que era utilizado como principal meio de transporte no Brasil até o surgimento da ferrovia no final do século XIX. Compradores vindos de todos os cantos do país buscavam na feira esse meio de transporte, proporcionando uma dinamização das atividades urbanas, como o comércio, as oficinas e os estabelecimentos manufatureisros e industriais. Desta forma, o espaço sorocabano foi produzido de forma específica e diferenciado dos demais lugares que tiveram na agricultura a base para a produção espacial

Spider venom neurotoxin based bioinsecticides: A novel bioactive for the control of the Asian citrus psyllid Diaphorina citri (Hemiptera)

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is a key vector of the phloem-limited bacteria Candidatus Liberibacter asiaticus (CLas) associated with huanglongbing (HLB), the most serious and currently incurable disease of citrus worldwide. Here we report the first investigation into the potential use of a spider venom-derived recombinant neurotoxin, ω/κ-HxTx-Hv1h (hereafter HxTx-Hv1h) when delivered alone or when fused to snowdrop lectin (Galanthus nivalis agglutinin; GNA) to control D. citri. Proteins, including GNA alone, were purified from fermented transformed yeast Pichia pastoris cultures. Recombinant HxTx-Hv1h, HxTx-Hv1h/GNA and GNA were all orally toxic to D. citri, with Day 5 median lethal concentrations (LC 50) derived from dose-response artificial diet assays of 27, 20 and 52 μM, respectively. Western analysis of whole insect protein extracts confirmed that psyllid mortality was attributable to protein ingestion and that the fusion protein was stable to cleavage by D. citri proteases. When applied topically (either via droplet or spray) HxTx-Hv1h/GNA was the most effective of the proteins causing >70 % mortality 5 days post treatment, some 2 to 3-fold higher levels of mortality as compared to the toxin alone. By contrast, no significant mortality or phenotypic effects were observed for bumble bees (Bombus terrestris L.) fed on the recombinant proteins in acute toxicity assays. This suggests that HxTx-Hv1h/GNA has potential as a novel bioinsecticide for the management of D. citri offering both enhanced target specificity as compared to chemical pesticides and compatibility with integrated pest management (IPM) strategies

Endoscopic ultrasound-guided transvascular needle biopsy of thoracic and abdominal lesions: a multicenter experience

Background and study aims Traditionally in the case of a vascular interposition, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) has been contraindicated. A transvascular route (TV) is feasible and probably a safe alternative approach in selected patients, but data are scarce. The primary aim of this study was to analyze the diagnostic yield and safety of EUS-TV-FNA in thoracic and abdominal lesions. Secondary aims included evaluation of the clinical impact and technical aspects. Patients and methods A retrospective multicenter study was conducted with inclusion of all consecutive patients that underwent EUS-TV-FNA from July 2007 to January 2020. Feasibility, cytopathology, procedure details, and safety were evaluated. Univariate analysis was performed to identify variables associated with incidents, cytopathological diagnosis, and clinical impact. Results Data were collected from a total of 49 cases and 50 EUS-TV-FNAs. The aorta (n = 19) and portal system (n = 17) were the most frequently punctured. The most frequent lesions were mediastinal lymph nodes (n = 13) and pancreatic tumors (n = 11). The diagnostic yield was 86 %, and there were nondiagnostic samples in seven cases. Overall sensitivity, specificity, and accuracy were 88% (95 % CI, 0.74-0.96), 100% (95 % CI, 0.59-1), and 90% (95 % CI, 0.78-0.96), respectively. Only three incidents were detected: two mural hematomas and a self-limited bleeding of gastroduodenal artery. In most patients, there was a significant impact on clinical management (88%). Arterial vessel and ASA-III had a trend with incidents (both, P < 0.08). Rapid on-site evlauation was found to be an independent predictor for obtaining a conclusive sample (OR 6.2; 95%CI, 1.06-36.73, P < 0.04). Conclusions EUS-TV-FNA is feasible, seems to be safe, and can be recommended when no other targets are available, and the information obtained would impact on the clinical plan