426 research outputs found

    Plant-derived hard carbon as anode for sodium-ion batteries: A comprehensive review to guide interdisciplinary research

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    Sodium-ion batteries (SIBs) are one of the most promising candidates to replace lithium-ion batteries (LIBs) in grid-scale energy storage applications. SIBs technology is still in an early development stage and new feasible and low-cost active materials are required. The design of high-performance anodes and the fully understanding of the sodium storage mechanisms are the main bottleneck to overcome. Hard carbons (HCs) are extensively studied as anode material since sodium ions can be intercalated in pseudographitic domains and reversibly adsorbed in surface edges, defects and nanopores. This review aims at providing a comprehensive overview of the current state of knowledge of plant-derived HC anodes in SIBs, which can be helpful for researchers from different backgrounds working in the field. Working principles of SIBs are summarized, together with a detailed description of the Na-ion storage mechanisms in hard carbon anodes proposed to date. Finally, an exhaustive literature review on the performance of plant-derived HCs in SIBs is presented, with special focus on the synthesis pathways (including activation and/or doping treatments)

    Gastropods In Seagrass Beds Of Tongkeina Beach Waters, Manado North Sulawesi

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    The Tongkeina coastal waters have relatively extensive tidal areas. In addition to the seagrass community, there are also distinctive coastal communities such as mangroves and coral reefs. Coastal resources in this region are often used by the local community as a food source and have been used as a place of recreation and hotels as well. This is the reason for this study to find out the existence of gastropods on the seagrass beds in the Tongkeina area. It is expected that this study will provide information on the development and existence of the gastropods in coping with the pressure due to the construction of the hotel several years before. The methods of analysis used in this study including identification of gastropods, density, dominance, and diversity. The same research has been conducted several years before, and therefore this information was used as a comparison of the development of gastropods in the area. Thirty-five species (23 genera) were identified, with the highest density recorded was Nassarius gruneri, 0.8667 Individual/m², the dominance of 0.13972, and diversity (H'= 2.6853) which is greater than the results of the previous study 5 years ago (H’=1,9382). These results indicate that these waters are in the process of improving from previous environmental conditions.Keywords : Gastropod, coastal, domination, diversity, Tongkeina. ABSTRAKPerairan pesisir Tongkeina memiliki wilayah pasang surut relatif luas. Selain komunitas Lamun,   juga  terdapat komunitas khas wilayah pesisir lainnya seperti Mangrove dan Terumbu karang. Sumber daya pesisir di wilayah ini  sering digunakan  untuk kebutuhan makanan masyarakat, di samping itu telah dimanfaatkan sebagai tempat rekreasi dan  Hotel. Hal ini menjadi alasan untuk mengetahui keberadaan Gastropoda di hamparan Lamun di daerah Tongkeina.  Diharapkan dapat memberikan informasi perkembangan keberadaan Gastropoda, setelah melewati tekanan akibat dibangunnya hotel sejak beberapa tahun sebelumnya. Metoda analisis yaitu jenis-jenis Gastropoda, kepadatan, dominasi, dan keanekaragaman. Hal yang sama juga telah dilakukan beberapa tahun sebelumnya, sehingga informasi ini dapat dijadikan pembanding perkembangan Gastropoda di daerah tersebut. Diperoleh 35 spesies (23 genera), kepadatan tertinggi adalah Nassarius gruneri, 0.8667 Ind/m², dominasi sebesar 0.13972, dan keanekaragamannya (H’= 2.6853) lebih besar dari hasil penelitian  5 tahun sebelumnya yaitu . 1,9382. Hasil ini menunjukkan bahwa perairan tersebut berada dalam proses perbaikan kondisi lingkungannya.Kata Kunci : Gastropoda, pesisir, dominasi, keanekaragaman, Tongkeina

    Environmental Factors of the Home Affect the Density of Aedes Aegypti (Diptera: Culicidae)

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    The transmission of Dengue Hemorrhagic Fever (DHF) by Aedes aegypti and Aedes albopictus mosquitoes is influenced by climate change and several environmental factors, namely light intensity, CO2, temperature, humidity, housing condition, drainage, and vegetation. This study aims to identify the relationship between environmental factors and dengue vector population density. This research applies an observational analytic study with a cross-sectional design. The study was conducted in 2012, in the city of Yogyakarta, Indonesia, in 39 houses in the Kricak Village and in 50 houses in the Prenggan Village. Data were collected by observation, interview, and completing checklists, as well as by measuring environmental variables. The differential effect of various factors influencing mosquito density was tested using an independent sample t-test for physical environmental factors and chi-square test for the variable physical condition of the house, biologically relevant environmental factors, drainage, residential density, and the distance between houses. The probability value was p <0.05. The results showed that differences in the physical environment, the physical condition of the house, residential density, and vegetation, all affect the density of dengue vector mosquitoes in the villages of Kricak and Prenggan. The need of raising public awareness about healthy living and care for the environment, along with advocacy to stakeholders, is important for vector density control

    Waste hemp hurd as a sustainable precursor for affordable and high-rate hard carbon-based anodes in sodium-ion batteries

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    The present study reports the promising potential of waste hemp-hurd-derived carbons as anodes in sodium-ion batteries (SIBs). Carbons were produced through an easily scalable process consisting of pyrolysis of raw biomass at 500 °C followed by mild chemical activation of the resulting char through wet impregnation with K2CO3 and subsequent heating of the solid phase (after filtration and drying) up to 700 or 800 °C under nitrogen. The best electrochemical performance was observed for the hard carbon activated at a char-K2CO3 mass ratio of 1:4 and heated up to 800 °C, which exhibited an excellent initial coulombic efficiency (73%) and achieved reversible charge capacities of 267 and 79 mAh g–1 at 0.03 and 1 A g–1, respectively. This material also exhibited an impressive cyclic stability and rate capability, with a capacity retention of 96% after 300 cycles at a current density of 2 A g–1. This more than satisfactory performance could be related to the textural and structural features of the hard carbon, which include moderate interconnected microporosity (with pore sizes below 1 nm), an appropriate concentration of defects in the carbon structure, relatively large interplanar distances, and a certain number of closed pores

    Using pneumococcal and rotavirus surveillance in vaccine decision-making: A series of case studies in Bangladesh, Armenia and the Gambia.

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    Pneumonia and diarrhea are the leading causes of child morbidity and mortality globally and are vaccine preventable. The WHO-coordinated Global Rotavirus and Invasive Bacterial Vaccine-Preventable Disease Surveillance Networks support surveillance systems across WHO regions to provide burden of disease data for countries to make evidence-based decisions about introducing vaccines and to demonstrate the impact of vaccines on disease burden. These surveillance networks help fill the gaps in data in low and middle-income countries where disease burden and risk are high but support to sustain surveillance activities and generate data is low. Through a series of country case studies, this paper reviews the successful use of surveillance data for disease caused by pneumococcus and rotavirus in informing national vaccine policy in Bangladesh, Armenia and The Gambia. The case studies delve into ways in which countries are leveraging and building capacity in existing surveillance infrastructure to monitor other diseases of concern in the country. Local institutions have been identified to play a critical role in making surveillance data available to policymakers. We recommend that countries review local or regional surveillance data in making vaccine policy decisions. Documenting use of surveillance activities can be used as advocacy tools to convince governments and external funders to invest in surveillance and make it a priority immunization activity

    Effect of hemicellulose liquid phase on the enzymatic hydrolysis of autohydrolyzed Eucalyptus globulus wood

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    In this work, Eucalyptus globulus wood was pretreated under non-isothermal autohydrolysis process at 210, 220, and 230 °C, obtaining a pretreated solid with high cellulose content and a hemicellulosic liquid phase (HLP) containing mainly xylose, acetic acid, furfural, xylooligosaccharides, and phenolic compounds. The maximum concentration of xylooligosaccharides (8.97 g/L) and phenolic compounds (2.66 g/L) was obtained at 210 and 230 °C, respectively. To evaluate the effect of HLP addition on the enzymatic hydrolysis using unwashed pretreated solid as substrate, different proportions of HLP were studied. Also, in order to use the whole slurry on enzymatic hydrolysis, the supplementation of xylanases was evaluated. Glucose concentration of 107.49 g/L (corresponding to 74.65 % of conversion) was obtained using pretreated solid at 220 °C liquid/solid ratio (LSR) of 4 g/g and enzyme solid ratio (ESR) of 25 FPU/gwithout the addition of HLP. Thus, it was shown that the unwashed pretreated solids are susceptible to enzymatic hydrolysis contributing to reduce operational cost (water consumption). Additionally, the influence of the inhibitory compounds in the HLP was shown to affect the enzymatic hydrolysis. Results indicated that 82.52 g/L of glucose (59.37 % of conversion) was obtained, using 100 % of HLP at LSR of 4 g/g and ESR of 16 FPU/g at 210 °C of pretreated solid. However, a positive effect was shown on the enzymatic hydrolysis when the xylanases were added using 100 % of HLP, increasing to 35 and 27 % in the glucose production with respect to whole slurry without addition of xylanases.The authors A. Romani and F. B. Pereira thank to the Portuguese Foundation for Science and Technology (FCT, Portugal) for their fellowships (grant number, SFRH/BPD/77995/2011 and SFRH/BD/64776/2009, respectively)

    Somalia: fragilidad y perspectivas de futuro

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    Este cuaderno contiene: "Introducción" "Prólogo" "De la unidad en 1960 a la desintegración: cronología de un Estado fallido" "Las migraciones en Somalia: mirando al pasado para comprender el presente" "Algunos datos sobre la cooperación internacional en Somalia" "Describir o prescribir: uso de la noción de Estado Fallido en las crisis somalíes""Los principios de la OCDE sobre intervención en Estados frágiles y su aplicación al caso de Somalia

    Polygenic risk for obesity and its interaction with lifestyle and sociodemographic factors in European children and adolescents

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    Background Childhood obesity is a complex multifaceted condition, which is influenced by genetics, environmental factors, and their interaction. However, these interactions have mainly been studied in twin studies and evidence from population-based cohorts is limited. Here, we analyze the interaction of an obesity-related genome-wide polygenic risk score (PRS) with sociodemographic and lifestyle factors for BMI and waist circumference (WC) in European children and adolescents. Methods The analyses are based on 8609 repeated observations from 3098 participants aged 2-16 years from the IDEFICS/I.Family cohort. A genome-wide polygenic risk score (PRS) was calculated using summary statistics from independent genome-wide association studies of BMI. Associations were estimated using generalized linear mixed models adjusted for sex, age, region of residence, parental education, dietary intake, relatedness, and population stratification. Results The PRS was associated with BMI (beta estimate [95% confidence interval (95%-CI)] = 0.33 [0.30, 0.37], r(2) = 0.11, p value = 7.9 x 10(-81)) and WC (beta [95%-CI] = 0.36 [0.32, 0.40], r(2) = 0.09, p value = 1.8 x 10(-71)). We observed significant interactions with demographic and lifestyle factors for BMI as well as WC. Children from Southern Europe showed increased genetic liability to obesity (BMI: beta [95%-CI] = 0.40 [0.34, 0.45]) in comparison to children from central Europe (beta [95%-CI] = 0.29 [0.23, 0.34]), p-interaction = 0.0066). Children of parents with a low level of education showed an increased genetic liability to obesity (BMI: beta [95%-CI] = 0.48 [0.38, 0.59]) in comparison to children of parents with a high level of education (beta [95%-CI] = 0.30 [0.26, 0.34]), p-interaction = 0.0012). Furthermore, the genetic liability to obesity was attenuated by a higher intake of fiber (BMI: beta [95%-CI] interaction = -0.02 [-0.04,-0.01]) and shorter screen times (beta [95%-CI] interaction = 0.02 [0.00, 0.03]). Conclusions Our results highlight that a healthy childhood environment might partly offset a genetic predisposition to obesity during childhood and adolescence.Peer reviewe

    Applied science facilitates the large-scale expansion of protected areas in an Amazonian hot spot

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    Meeting international commitments to protect 17% of terrestrial ecosystems worldwide will require \u3e3 million square kilometers of new protected areas and strategies to create those areas in a way that respects local communities and land use. In 2000–2016, biological and social scientists worked to increase the protected proportion of Peru’s largest department via 14 interdisciplinary inventories covering \u3e9 million hectares of this megadiverse corner of the Amazon basin. In each landscape, the strategy was the same: convene diverse partners, identify biological and sociocultural assets, document residents’ use of natural resources, and tailor the findings to the needs of decision-makers. Nine of the 14 landscapes have since been protected (5.7 million hectares of new protected areas), contributing to a quadrupling of conservation coverage in Loreto (from 6 to 23%). We outline the methods and enabling conditions most crucial for successfully applying similar campaigns elsewhere on Earth
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