Instituto Nacional de Tecnologia

Potato (Solanum tuberosum L.) is the world’s most important non-grain food crop and is central to global food security. It is clonally propagated, highly heterozygous, autotetraploid, and suffers acute inbreeding depression. Here we use a homozygous doubled-monoploid potato clone to sequence and assemble 86% of the 844-megabase genome. We predict 39,031 protein-coding genes and present evidence for at least two genome duplication events indicative of a palaeopolyploid origin. As the first genome sequence of an asterid, the potato genome reveals 2,642 genes specific to this large angiosperm clade. We also sequenced a heterozygous diploid clone and show that gene presence/absence variants and other potentially deleterious mutations occur frequently and are a likely cause of inbreeding depression. Gene family expansion, tissue-specific expression and recruitment of genes to new pathways contributed to the evolution of tuber development. The potato genome sequence provides a platform for genetic improvement of this vital crop. The genome of the potato (Solanum tuberosum L.), a staple crop vital to food security, has been sequenced. The Potato Genome Sequencing Consortium sequenced a homozygous doubled-monoploid potato clone as well as a heterozygous diploid clone. Genome analysis reveals traces of at least two genome duplication events and genes specific to Asterids, a large clade of flowering plants of which the potato is the first to be sequenced. Gene presence/absence variants and other potentially deleterious mutations are frequent and may be the cause of inbreeding depression. The genome sequence will facilitate genetic improvements in the potato with a view to improving yield and to increasing disease and stress resistance of this crop, which is a now a significant component of worldwide food production and is becoming increasingly important in the developing world.

Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth's land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.

ADVERTISEMENT RETURN TO ISSUEPREVReviewNEXTProduction of Hydrogen from Ethanol: Review of Reaction Mechanism and Catalyst DeactivationLisiane V. Mattos†, Gary Jacobs‡, Burtron H. Davis‡, and Fábio B. Noronha*§View Author Information† Departamento de Engenharia Química e de Petróleo, Universidade Federal Fluminense (UFF), Rua Passo da Pátria, 156-CEP 24210-240, Niterói, RJ, Brazil‡ Center for Applied Energy Research, The University of Kentucky, 2540 Research Park Drive, Lexington, Kentucky 40511, United States § Instituto Nacional de Tecnologia−INT, Av. Venezuela 82, CEP 20081-312, Rio de Janeiro, Brazil*E-mail: [email protected]. Tel.: (55 21) 2123 1177. Fax: (55 21) 2123 1166.Cite this: Chem. Rev. 2012, 112, 7, 4094–4123Publication Date (Web):May 23, 2012Publication History Received6 January 2011Published online23 May 2012Published inissue 11 July 2012https://pubs.acs.org/doi/10.1021/cr2000114https://doi.org/10.1021/cr2000114review-articleACS PublicationsCopyright © 2012 American Chemical SocietyRequest reuse permissionsArticle Views13844Altmetric-Citations638LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Aldehydes,Catalysts,Ethanol,Metals,Organic reactions Get e-Alerts

Philipp Simon, Massimo Iorizzo, Allen Van Deynze and colleagues report the high-quality assembly of the carrot genome, providing an important resource for crop improvement. They find a candidate gene that regulates carotenoid accumulation and gain further insights into asterid genome evolution, including characterization of two new polyploidization events. We report a high-quality chromosome-scale assembly and analysis of the carrot (Daucus carota) genome, the first sequenced genome to include a comparative evolutionary analysis among members of the euasterid II clade. We characterized two new polyploidization events, both occurring after the divergence of carrot from members of the Asterales order, clarifying the evolutionary scenario before and after radiation of the two main asterid clades. Large- and small-scale lineage-specific duplications have contributed to the expansion of gene families, including those with roles in flowering time, defense response, flavor, and pigment accumulation. We identified a candidate gene, DCAR_032551, that conditions carotenoid accumulation (Y) in carrot taproot and is coexpressed with several isoprenoid biosynthetic genes. The primary mechanism regulating carotenoid accumulation in carrot taproot is not at the biosynthetic level. We hypothesize that DCAR_032551 regulates upstream photosystem development and functional processes, including photomorphogenesis and root de-etiolation.

Björn Usadel and colleagues report the genome sequence of the wild tomato species Solanum pennellii. The authors identify genes important for stress tolerance, metabolism and fruit maturation and suggest that transposable elements have had an important role in the evolution of the S. penellii stress response. Solanum pennellii is a wild tomato species endemic to Andean regions in South America, where it has evolved to thrive in arid habitats. Because of its extreme stress tolerance and unusual morphology, it is an important donor of germplasm for the cultivated tomato Solanum lycopersicum1. Introgression lines (ILs) in which large genomic regions of S. lycopersicum are replaced with the corresponding segments from S. pennellii can show remarkably superior agronomic performance2. Here we describe a high-quality genome assembly of the parents of the IL population. By anchoring the S. pennellii genome to the genetic map, we define candidate genes for stress tolerance and provide evidence that transposable elements had a role in the evolution of these traits. Our work paves a path toward further tomato improvement and for deciphering the mechanisms underlying the myriad other agronomic traits that can be improved with S. pennellii germplasm.

Diptera, one of the four megadiverse insect orders, are the best-catalogued insects in all biogeographic regions. True flies are cosmopolitan with about 150,000 described species in 158 families

Grazing represents the most extensive use of land worldwide. Yet its impacts on ecosystem services remain uncertain because pervasive interactions between grazing pressure, climate, soil properties, and biodiversity may occur but have never been addressed simultaneously. Using a standardized survey at 98 sites across six continents, we show that interactions between grazing pressure, climate, soil, and biodiversity are critical to explain the delivery of fundamental ecosystem services across drylands worldwide. Increasing grazing pressure reduced ecosystem service delivery in warmer and species-poor drylands, whereas positive effects of grazing were observed in colder and species-rich areas. Considering interactions between grazing and local abiotic and biotic factors is key for understanding the fate of dryland ecosystems under climate change and increasing human pressure.

Advances in nanoparticle (NP) production and demand for control over nanoscale systems have had significant impact on tissue engineering and regenerative medicine (TERM). NPs with low toxicity, contrasting agent properties, tailorable characteristics, targeted/stimuli-response delivery potential, and precise control over behavior (via external stimuli such as magnetic fields) have made it possible their use for improving engineered tissues and overcoming obstacles in TERM. Functional tissue and organ replacements require a high degree of spatial and temporal control over the biological events and also their real-time monitoring. Presentation and local delivery of bioactive (growth factors, chemokines, inhibitors, cytokines, genes etc.) and contrast agents in a controlled manner are important implements to exert control over and monitor the engineered tissues. This need resulted in utilization of NP based systems in tissue engineering scaffolds for delivery of multiple growth factors, for providing contrast for imaging and also for controlling properties of the scaffolds. Depending on the application, materials, as polymers, metals, ceramics and their different composites can be utilized for production of NPs. In this review, we will cover the use of NP systems in TERM and also provide an outlook for future potential use of such systems.

OBJECTIVE: To investigate cut-off values for HOMA1-IR and HOMA2-IR to identify insulin resistance (IR) and metabolic syndrome (MS), and to assess the association of the indexes with components of the MS. METHODS: Nondiabetic subjects from the Brazilian Metabolic Syndrome Study were studied (n = 1,203, 18 to 78 years). The cut-off values for IR were determined from the 90th percentile in the healthy group (n = 297) and, for MS, a ROC curve was generated for the total sample. RESULTS: In the healthy group, HOMA-IR indexes were associated with central obesity, triglycerides and total cholesterol (p < 0.001). The cut-off values for IR were: HOMA1-IR > 2.7 and HOMA2-IR > 1.8; and, for MS were: HOMA1-IR > 2.3 (sensitivity: 76.8%; specificity: 66.7%) and HOMA2-IR > 1.4 (sensitivity: 79.2%; specificity: 61.2%). CONCLUSION: The cut-off values identified for HOMA1-IR and HOMA2-IR indexes have a clinical and epidemiological application for identifying IR and MS in Westernized admixtured multi-ethnic populations.

Abstract Transgenic tomato ( Solanum lycopersicum ) plants expressing a fragment of a fumarate hydratase (fumarase) gene in the antisense orientation and exhibiting considerable reductions in the mitochondrial activity of this enzyme show impaired photosynthesis. The rate of the tricarboxylic acid cycle was reduced in the transformants relative to the other major pathways of carbohydrate oxidation and the plants were characterized by a restricted rate of dark respiration. However, biochemical analyses revealed relatively little alteration in leaf metabolism as a consequence of reducing the fumarase activity. That said, in comparison to wild‐type plants, CO 2 assimilation was reduced by up to 50% under atmospheric conditions and plants were characterized by a reduced biomass on a whole plant basis. Analysis of further photosynthetic parameters revealed that there was little difference in pigment content in the transformants but that the rate of transpiration and stomatal conductance was markedly reduced. Analysis of the response of the rate of photosynthesis to variation in the concentration of CO 2 confirmed that this restriction was due to a deficiency in stomatal function.

Abstract The history of conifers introduced earlier elsewhere in the southern hemisphere suggests that recent invasions in Argentina, Brazil, Chile and Uruguay are likely to increase in number and size. In South Africa, New Zealand and Australia, early ornamental introductions and small forestry plantations did not lead to large‐scale invasions, while subsequent large plantations were followed with a lag of about 20–30 years by troublesome invasions. Large‐scale conifer plantation forestry in South America began about 50–80 years later than in South Africa, Australia and New Zealand, while reports of invasions in South America lagged behind those in the latter nations by a century. Impacts of invading non‐native conifers outside South America are varied and include replacement of grassland and shrubland by conifer forest, alteration of fire and hydrological regimes, modification of soil nutrients, and changes in aboveground and belowground biotic communities. Several of these effects have already been detected in various parts of South America undergoing conifer invasion. The sheer amount of area planted in conifers is already very large in Chile and growing rapidly in Argentina and Brazil. This mass of reproductive trees, in turn, produces an enormous propagule pressure that may accelerate ongoing invasions and spark new ones at an increasing rate. Regulations to control conifer invasions, including measures to mitigate spread, were belatedly implemented in New Zealand and South Africa, as well as in certain Australian states, inspired by observations on invasions in those nations. Regulations in South America are weaker and piecemeal, but the existing research base on conifer invasions elsewhere could be useful in fashioning effective regulations in South America. Pressure from foreign customers in South Africa has led most companies there to seek certification through the Forestry Stewardship Council; a similar programme operates in Australia. Such an approach may be promising in South America.

In vitro production (IVP) of embryos and associated technologies in cattle have shown significant progress in recent years, in part driven by a better understanding of the full potential of these tools by end users. The combination of IVP with sexed semen (SS) and genomic selection (GS) is being successfully and widely used in North America, South America and Europe. The main advantages offered by these technologies include a higher number of embryos and pregnancies per unit of time, and a wider range of potential female donors from which to retrieve oocytes (including open cyclic females and ones up to 3 months pregnant), including high index genomic calves, a reduced number of sperm required to produce embryos and increased chances of obtaining the desired sex of offspring. However, there are still unresolved aspects of IVP of embryos that limit a wider implementation of the technology, including potentially reduced fertility from the use of SS, reduced oocyte quality after in vitro oocyte maturation and lower embryo cryotolerance, resulting in reduced pregnancy rates compared to in vivo-produced embryos. Nevertheless, promising research results have been reported, and work is in progress to address current deficiencies. The combination of GS, IVP and SS has proven successful in the commercial field in several countries assisting practitioners and cattle producers to improve reproductive performance, efficiency and genetic gain.

The industrial production of sugar syrups from lignocellulosic materials requires the conduction of the enzymatic hydrolysis step at high-solids loadings (i.e., with over 15% solids [w/w] in the reaction mixture). Such conditions result in sugar syrups with increased concentrations and in improvements in both capital and operational costs, making the process more economically feasible. However, this approach still poses several technical hindrances that impact the process efficiency, known as the "high-solids effect" (i.e., the decrease in glucan conversion yields as solids load increases). The purpose of this review was to present the findings on the main limitations and advances in high-solids enzymatic hydrolysis in an updated and comprehensive manner. The causes for the rheological limitations at the onset of the high-solids operation as well as those influencing the "high-solids effect" will be discussed. The subject of water constraint, which results in a highly viscous system and impairs mixing, and by extension, mass and heat transfer, will be analyzed under the perspective of the limitations imposed to the action of the cellulolytic enzymes. The "high-solids effect" will be further discussed vis-à-vis enzymes end-product inhibition and the inhibitory effect of compounds formed during the biomass pretreatment as well as the enzymes' unproductive adsorption to lignin. This review also presents the scientific and technological advances being introduced to lessen high-solids hydrolysis hindrances, such as the development of more efficient enzyme formulations, biomass and enzyme feeding strategies, reactor and impeller designs as well as process strategies to alleviate the end-product inhibition. We surveyed the academic literature in the form of scientific papers as well as patents to showcase the efforts on technological development and industrial implementation of the use of lignocellulosic materials as renewable feedstocks. Using a critical approach, we expect that this review will aid in the identification of areas with higher demand for scientific and technological efforts.

This work investigates the effect of the type of support (SiO 2, Al 2 O 3, TiO 2, ZrO 2, CeO 2, and CeZrO 2 ) on the performance of Pd-based catalysts for the hydrodeoxygenation of phenol at 573 K using a fixed-bed reactor. Product distribution is significantly affected by the type of support. Benzene was the major product over Pd/TiO 2 and Pd/ZrO 2; on the other hand, cyclohexanone was the main compound over Pd/SiO 2, Pd/Al 2 O 3, Pd/CeO 2, and Pd/CeZrO 2 . A reaction mechanism based on the tautomerization of phenol was proposed on the basis of DRIFTS experiments and catalytic tests with the intermediate products. The high selectivity to benzene over Pd/TiO 2 and Pd/ZrO 2 catalysts is likely due to the oxophilic sites of this support represented by incompletely coordinated Ti 4+ and Zr 4+ cations in close proximity to the periphery of metal particles. The greater interaction between oxygen in the keto-tautomer intermediate with oxophilic sites promotes the selective hydrogenation of C═O bond. Pd/SiO 2, Pd/Al 2 O 3, Pd/TiO 2, and Pd/ZrO 2 catalysts significantly deactivated during TOS. However, Pd/CeO 2 and Pd/CeZrO 2 were more stable, and only slight losses in activity were observed. Carbon deposits were not detected by Raman spectroscopy after reaction. DRIFTS experiments under reaction conditions revealed a buildup of phenoxy and intermediate species during reaction. These species remained adsorbed on the Lewis acid sites, blocking those sites and inhibiting further reactant adsorption. The growth of Pd particle size and the reduction in acid site density during HDO of phenol were the primary routes of catalyst deactivation. The higher stability of Pd/CeO 2 and Pd/CeZrO 2 catalysts is likely due to the higher amount of oxygen vacancies of these supports.

The performance of Pd catalysts supported on SiO2, Al2O3 and ZrO2 for the hydrodeoxygenation (HDO) of phenol has been compared in the gas phase, at 300 °C and 1 atm using a fixed bed reactor. While Pd supported on SiO2 and Al2O3 exhibits high selectivity to cyclohexanone, when supported on an oxophilic support such as ZrO2, it favors the selectivity toward benzene, reducing the formation of ring-hydrogenated products, cyclohexanone and cyclohexanol. Diffuse reflectance infrared Fourier transform spectroscopy experiments support the participation of a keto-tautomer intermediate (2,4-cyclohexadienone) in the reaction. This intermediate can be hydrogenated in two different pathways. If the ring is hydrogenated, cyclohexanone and cyclohexanol are dominant products, as in the case of Pd/SiO2 and Pd/Al2O3 catalysts. By contrast, if the carbonyl group of the keto-intermediate tautomer is hydrogenated, benzene is directly formed via rapid dehydration of the unstable cyclohexadienol intermediate. This is observed in the case of Pd/ZrO2 catalyst. These results demonstrate that the selectivity for HDO of phenol can be controlled by using supports of varying oxophilicity.

Abstract Spatially resolved estimates of change in soil organic carbon (SOC) stocks are necessary for supporting national and international policies aimed at achieving land degradation neutrality and climate change mitigation. In this work we report on the development, implementation and application of a data‐driven, statistical method for mapping SOC stocks in space and time, using Argentina as a pilot. We used quantile regression forest machine learning to predict annual SOC stock at 0–30 cm depth at 250 m resolution for Argentina between 1982 and 2017. The model was calibrated using over 5,000 SOC stock values from the 36‐year time period and 35 environmental covariates. We preprocessed normalized difference vegetation index (NDVI) dynamic covariates using a temporal low‐pass filter to allow the SOC stock for a given year to depend on the NDVI of the current as well as preceding years. Predictions had modest temporal variation, with an average decrease for the entire country from 2.55 to 2.48 kg C m −2 over the 36‐year period (equivalent to a decline of 211 Gg C, 3.0% of the total 0–30 cm SOC stock in Argentina). The Pampa region had a larger estimated SOC stock decrease from 4.62 to 4.34 kg C m −2 (5.9%) during the same period. For the 2001–2015 period, predicted temporal variation was seven‐fold larger than that obtained using the Tier 1 approach of the Intergovernmental Panel on Climate Change and United Nations Convention to Combat Desertification. Prediction uncertainties turned out to be substantial, mainly due to the limited number and poor spatial and temporal distribution of the calibration data, and the limited explanatory power of the covariates. Cross‐validation confirmed that SOC stock prediction accuracy was limited, with a mean error of 0.03 kg C m −2 and a root mean squared error of 2.04 kg C m −2 . In spite of the large uncertainties, this work showed that machine learning methods can be used for space–time SOC mapping and may yield valuable information to land managers and policymakers, provided that SOC observation density in space and time is sufficiently large. Highlights We tested the use of machine learning for space–time mapping of soil organic carbon (SOC) stock. Predictions for Argentina from 1982 to 2017 showed a 3% decrease of the topsoil SOC stock over time. The machine learning model predicted a greater temporal variation than the IPCC Tier 1 approach. Accurate machine learning SOC stock prediction requires dense soil sampling in space and time.

Abstract The effect of dimethylarsenic acid (DMAA) applied to the root on arsenic (As) uptake and concentration, net photosynthesis (Pn), and growth parameters of rice (Oryza sativa L. cv. ‘Mercury') plants was studied. The experiment consisted of four treatments (0, 0.2, 0.8, and 1.6 mg As/L) with four replications in a completely randomized design. The DMAA was applied in nutrient solution as its sodium salt. The solution culture was changed every four days to avoid changes in the As chemical form. Arsenic uptake and concentration in shoot and root increased upon increased DMAA concentration in solution. Upon uptake, DMAA was readily translocated to the shoot. At the two higher rates of DMAA application (0.8 and 1.6 mg As/L), Pn and photosynthetic capacity were significantly decreased in response to tissue As concentration. Leaf area and dry matter production were also significantly reduced at the two higher rates of DMAA. At the lower rate (0.2 mg As/L) of DMAA application, there was no significant reduction in Pn or growth. Dimethylarsenic acid application did not affect nutrient allocation within the rice plant at concentration levels used in this study.

The need for new materials to substitute injured or damaged parts of the human body has led scientists of different areas to investigate bioceramics since the 70's, when other materials in use started to show rejection problems. Ceramics show some advantages like being the material that best mimics the bone tissue, although present low toughness when compared with the metallic materials. As patients have become more and more demanding regarding esthetic and biocompatibility aspects of their dental restorations, ceramic material has become a main object of scientific interest especially from the material point of view. The alumina-zirconia composites are one of the relatively good and promising candidate for biomaterials application, due to biocompatibility and their mechanical properties that combines high flexural strength with a high toughness. The aim of the present work is to analyze the mechanical properties of these composites, where Y-TZP zirconia content was varied from 5 to 80 wt.% These systems can achieve a flexural strength 93 % and fracture toughness 29 % superior when compared to the pure alumina ceramics. These results showed that ceramic abutments components can be prepared for prosthetic rehabilitations with dental implants.

The hard tick family Ixodidae currently comprises 762 species worldwide, but an analysis of the occurrence of these species in the world´s countries, territories, zoogeographic regions (Afrotropical, Australasian, Nearctic, Neotropical, Oriental, Palearctic) and remote islands has not been attempted since 2009. Here, we present and critically discuss distributional data for all currently accepted ixodid species known from 226 countries and territories in six zoogeographic realms. This summary of ixodid tick biogeography should prove to be a valuable reference for biologists interested in ticks as organisms as well as specialists focusing on tick-borne diseases. Data for all species treated here were derived from a literature search that ended on March 31, 2022.

This work studies the effect of zirconia structure on the performance of Pd/ZrO 2 catalysts for hydrodeoxygenation of phenol at 300 °C and 1 atm using a fixed bed reactor. Benzene was the major product over Pd/t-ZrO 2, while significant formation of cyclohexanone was observed over Pd/m-ZrO 2 . On the other hand, Pd/m,t-ZrO 2 exhibited intermediary behavior. DRIFTS of adsorbed pyridine, NH 3 -TPD, and the dehydration of the cyclohexanol reaction revealed that the Pd/t-ZrO 2 catalyst exhibits a higher density of oxophilic sites than Pd/m-ZrO 2 and Pd/m,t-ZrO 2 . This promoted the formation of deoxygenated products. However, a mechanism involving dehydration of cyclohexanol to cyclohexene, followed by dehydrogenation to benzene, may not be ruled out. Pd/ZrO 2 catalysts significantly deactivated as a function of time on stream. Results of dehydrogenation of cyclohexane and dehydration of cyclohexanol indicate that the Pd particle size increased and the density of oxophilic sites decreased during the hydrodeoxygenation of the phenol reaction. In addition, the DRIFTS spectra under reaction conditions demonstrated that the coverage of oxophilic sites by phenoxy and intermediate species increased during the reaction. The growth of Pd particles is likely responsible for the losses in the metal–support interface that gradually inhibits the ability of the adsorbed species to turnover at the metal–support boundary.