1. |
- Elsik, Christine G., et al.
(author)
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The Genome Sequence of Taurine Cattle : A Window to Ruminant Biology and Evolution
- 2009
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 324:5926, s. 522-528
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Journal article (peer-reviewed)abstract
- To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
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2. |
- Araujo, Leonardo F., et al.
(author)
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Photonics with special optical fibers and nanoparticles
- 2016
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In: Optics InfoBase Conference Papers. - 9781943580163
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Conference paper (peer-reviewed)abstract
- Optical properties of nanorods in the presence of external electric field when confined to a special optical fiber was investigated, showing an increase of the longitudinal absorption peak in the presence of the field.
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3. |
- Bangoura, Charlotte, et al.
(author)
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Experiences, Preferences, and Needs of Adolescents and Urban Youth in Contraceptive Use in Conakry, 2019, Guinea
- 2021
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In: Epidemiologic Methods. - : Frontiers Media S.A.. - 2194-9263 .- 2161-962X. ; 2
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Journal article (peer-reviewed)abstract
- Introduction: The use of contraceptive methods is very low in Guinea, particularly among adolescents and young people. The purpose of this study is to analyze the experiences and expectations of adolescents and young people regarding the use of contraceptive methods in 2019 in Conakry, Guinea.Methods: We conducted a 6-month qualitative and descriptive study. Data were collected through individual in-depth interviews and focus group discussions with adolescents and young people, health providers and health policy makers. Two approaches of deductive and inductive analysis were used to synthesize the main insights from the data.Findings: Twenty-six participants were included in this study. Adolescents and young people have personal, family and community experiences that positively or negatively influence their contraceptive needs and preferences. Positive experiences include the relative cost of injectable forms, perceived absence of side effects of implants, proven efficacy and duration of action of the modern method used (implants and injectable form). Negative experiences included cost of implants remain high (15 Euros), perceived side effects including weight gain, pill compliance, method indiscretion, and low sensation of sexual pleasure for the condom. The preferences of the young participants were dominated by Implants and injectable forms that better meet their contraceptive needs. In terms of needs, the expectations expressed revolved around needs related to the health system, including sex education, reduction in the cost of some contraceptives (implants), availability of contraceptive methods, and equity in the provision of family planning services to adolescents and young people.Conclusion: Exploring the contraceptive experiences, needs and preferences of adolescents and young people reveals decision-making dilemmas. Adolescents and young people expressed their experiences in terms of the cost of preferred contraceptives (implants), side effects, proven efficacy, and duration of action. However, their decisions are still influenced by availability, equity in service delivery, and the involvement of parents and religious leaders in sex education. Decision-makers should then place particular emphasis on improving health service delivery, adolescent sexual and reproductive health, availability of preferred contraceptive methods at affordable cost, and a program on sexuality education with the involvement of parents and religious leaders and the promotion of condom use.
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4. |
- Bellot, S., et al.
(author)
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The likely extinction of hundreds of palm species threatens their contributions to people and ecosystems
- 2022
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In: Nature Ecology and Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 6, s. 1710-1722
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Journal article (peer-reviewed)abstract
- Protecting nature’s contributions to people requires accelerating extinction risk assessment and better integrating evolutionary, functional and used diversity with conservation planning. Here, we report machine learning extinction risk predictions for 1,381 palm species (Arecaceae), a plant family of high socio-economic and ecological importance. We integrate these predictions with published assessments for 508 species (covering 75% of all palm species) and we identify top-priority regions for palm conservation on the basis of their proportion of threatened evolutionarily distinct, functionally distinct and used species. Finally, we explore palm use resilience to identify non-threatened species that could potentially serve as substitutes for threatened used species by providing similar products. We estimate that over a thousand palms (56%) are probably threatened, including 185 species with documented uses. Some regions (New Guinea, Vanuatu and Vietnam) emerge as top ten priorities for conservation only after incorporating machine learning extinction risk predictions. Potential substitutes are identified for 91% of the threatened used species and regional use resilience increases with total palm richness. However, 16 threatened used species lack potential substitutes and 30 regions lack substitutes for at least one of their threatened used palm species. Overall, we show that hundreds of species of this keystone family face extinction, some of them probably irreplaceable, at least locally. This highlights the need for urgent actions to avoid major repercussions on palm-associated ecosystem processes and human livelihoods in the coming decades. © 2022, The Author(s), under exclusive licence to Springer Nature Limited.
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5. |
- Camara, Alexandre R., et al.
(author)
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Optical creation and erasure of the linear electrooptical effect in silica fiber
- 2015
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In: Optics Express. - : Optical Society of America. - 1094-4087. ; 23:14, s. 18060-18069
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Journal article (peer-reviewed)abstract
- We study the creation and erasure of the linear electrooptical effect in silicate fibers by optical poling. Carriers are released by exposure to green light and displaced with simultaneous application of an internal dc field. The second order nonlinear coefficient induced grows with poling bias. The field recorded (similar to 10(8) V/m) is comparable to that obtained through classical thermal poling of fibers. In the regime studied here, the second-order nonlinearity induced (similar to 0.06 pm/V) is limited by the field applied during poling (1.2 x 10(8) V/m). Optical erasure with high-power green light alone is very efficient. The dynamics of the writing and erasing process is discussed, and the two dimensional (2D) field distribution across the fiber is simulated. (C) 2015 Optical Society of America
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6. |
- Camara, Alexandre, et al.
(author)
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Study of thermally poled fibers with a two-dimensional model
- 2014
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In: Optics Express. - 1094-4087. ; 22:15, s. 17700-17715
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Journal article (peer-reviewed)abstract
- A two-dimensional (2D) numerical model is implemented to describe the movement of ions under thermal poling for the specific case of optical fibers. Three types of cations are considered (representing Na+, Li+ and H3O+) of different mobility values. A cross-sectional map of the carrier concentration is obtained as a function of time. The role of the various cations is investigated. The assumptions of the model are validated by comparing the predictions to experimental data of the time evolution of the nonlinearity induced. A variational analysis of poling parameters including temperature, poling voltage, sign of the bias potential and initial ionic concentrations is performed for a particular fiber geometry. The analysis allows identifying the impact of these parameters on the induced second-order nonlinearity in poled fibers.
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7. |
- Carvalho, Isabel C. S., et al.
(author)
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Pockels fibers by optical poling
- 2015
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In: Workshop on Specialty Optical Fibers and their Applications 2015. - Washington, D.C. : OSA. - 9781943580057
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Conference paper (peer-reviewed)abstract
- Silica fibers with internal electrodes biased with HV are poled when simultaneously excited by green light. The x(2) induced measured through the Pockels effect at 1.55 μm reaches ~0.11 pm/V. Poling and erasure are studied.
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8. |
- Colaço, Marcos, et al.
(author)
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Characterization of the microstructures of specialty optical fibers for electric-field sensing by propagation-based x-ray phase-contrast microtomography
- 2021
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In: Measurement science and technology. - : IOP Publishing Ltd. - 0957-0233 .- 1361-6501. ; 32:6
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Journal article (peer-reviewed)abstract
- In this work, we present a quantitative (statistical) 3D morphological characterization of optical fibers used in electric-field sensing. The characterization technique employs propagation-based x-ray phase-contrast microcomputed tomography (micro-CT). In particular, we investigate specialty optical fibers that contain microstructured holes that are electro-optically modified by thermal poling to induce second-order nonlinear effects (SONE). The efficiency of the SONE is reflected in the characterization parameter, Vπ, which is highly dependent on the dimensions of the fiber. The fiber microstructures must be uniform to support the fabrication of reproducible devices. The results obtained using the micro-CT technique show that uncertainty of ±1.7% arises in the determination of the expected value of the voltage that causes a change in the phase of the electromagnetic wave equal to π rad (Vπ ), demonstrating a great advantage, compared with other techniques e.g. SEM, which would need at least 1000 images of the cross-section of an optical fiber, taken at different points, making the process more expensive and time-consuming.
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9. |
- Etcheverry, Sebastián, et al.
(author)
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Microsecond switching of plasmonic nanorods in an all-fiber optofluidic component
- 2017
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In: Optica. - : Optical Society of America. - 2334-2536. ; 4:8, s. 864-870
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Journal article (peer-reviewed)abstract
- As information technologies move from electron-to photon-based systems, the need to rapidly modulate light is of paramount importance. Here, we study the evolution of the electric-field-induced alignment of gold nanorods suspended in organic solvents. The experiments were performed using an all-fiber optofluidic device, which enables convenient interaction of light, electric fields, and the nanorod suspension. We demonstrate microsecond nanorod switching times, three orders of magnitude faster than a traditional Freederickcz-based liquid crystal alignment mechanism. We find that the dynamics of the alignment agrees well with the Einstein-Smoluchowski relationship, allowing for the determination of the rotational diffusion coefficient and polarizability anisotropy of the nanorods as well as the effective length of the ligands capping the nanorods. The ability to dynamically control the optical properties of these plasmonic suspensions coupled with the point-to-point delivery of light from the fiber component, as demonstrated in this work, may enable novel ultrafast optical switches, filters, displays, and spatial light modulators.
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10. |
- Grace, O. M., et al.
(author)
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Plant Power: Opportunities and challenges for meeting sustainable energy needs from the plant and fungal kingdoms
- 2020
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In: Plants People Planet. - : Wiley. - 2572-2611. ; 2:5, s. 446-462
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Journal article (peer-reviewed)abstract
- Societal Impact Statement Bioenergy is a major component of the global transition to renewable energy technologies. The plant and fungal kingdoms offer great potential but remain mostly untapped. Their increased use could contribute to the renewable energy transition and addressing the United Nations Sustainable Development Goal 7 "Ensure access to affordable, reliable, sustainable and modern energy for all." Current research focuses on species cultivated at scale in temperate regions, overlooking the wealth of potential new sources of small-scale energy where they are most urgently needed. A shift towards diversified, accessible bioenergy technologies will help to mitigate and adapt to the threats of climate change, decrease energy poverty, improve human health by reducing indoor pollution, increase energy resilience of communities, and decrease greenhouse gas emissions from fossil fuels. SummaryBioenergy derived from plants and fungi is a major component of the global transition to renewable energy technologies. There is rich untapped diversity in the plant and fungal kingdoms that offers potential to contribute to the shift away from fossil fuels and to address the United Nations Sustainable Development Goal 7 (SDG7) "Ensure access to affordable, reliable, sustainable and modern energy for all." Energy poverty-the lack of access to modern energy services-is most acute in the Global South where biodiversity is greatest and least investigated. Our systematic review of the literature over the last 5 years (2015-2020) indicates that research efforts have targeted a very small number of plant species cultivated at scale, mostly in temperate regions. The wealth of potential new sources of bioenergy in biodiverse regions, where the implementation of SDG7 is most urgently needed, has been largely overlooked. We recommend next steps for bioenergy stakeholders-research, industry, and government-to seize opportunities for innovation to alleviate energy poverty while protecting biodiversity. Small-scale energy production using native plant species in bioenergy landscapes overcomes many pitfalls associated with bioenergy crop monocultures, such as biodiversity loss and conflict with food production. Targeted trait-based screening of plant species and biological screening of fungi are required to characterize the potential of this resource. The benefits of diversified, accessible bioenergy go beyond the immediate urgency of energy poverty as more diverse agricultural landscapes are more resilient, store more carbon, and could also reduce the drivers of the climate and environmental emergencies.
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