2,117 research outputs found

    The Zebrafish as an Alternative Animal Model for Ecotoxicological Research and Testing.

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    Abstract: Anthropogenic interventions have had a compromising effect on environmental health, intensifying the degradation of ecosystems, and the quantity of chemical pollutants released into nature. Therefore, research areas within the scope of environmental assessments and monitoring such as ecotoxicology have contributed to the determination of the toxic potential of contaminants. A small cyprinid known as the zebrafish (Danio rerio), the use of which has exponentially grown, is an alternative vertebrate model for scientific research, mainly in the assessment of environmental risks. The species exhibits several advantages for breeding in a laboratory, in addition to presenting multi-biomarkers of environmental toxicity. Thus, this review aims to present the main characteristics and advantages of working with this species, as well as show studies related to ecotoxicology involving biomarkers of toxicity in zebrafish. The results show a progressive trend towards employing the species in environmental risk analyses, it is an increasingly recommended species in the assessment of the toxicity level of a range of chemical pollutants. The development of future technologies must contribute to scientific advancement, rendering the potential application of this model organism an even more widespread one, which will certainly help in bridging knowledge gaps in various areas of study

    Avaliação da evapotranspiração estimada pelo modelo DSSAT/CROPGRO-Soybean para localidade de Piracicaba-SP.

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    A soja (Glycine max L.) é uma das principais commodity agrícola, principalmente no Brasil que tem parte significativa de seu PIB justificado pela agricultura. Nesse sentido é importante a realização de estudos relacionados a produtividade da soja, sendo bastante comum a utilização de modelos de produtividade. O experimento foi conduzido na cidade de Piracicaba-SP, utilizando-se a cultivar PRODUZA IPRO, dando início ao plantio no dia 09 de novembro de 2016, adotando-se sistema de plantio direto em uma área de antecessão de milho consorciado com braquiária. O objetivo deste trabalho, então, foi avaliar e comparar dentro da plataforma DSSAT, no modelo CROPGRO-Soybean dois métodos (o primeiro método utilizado foi o de Penman-Monteith, o segundo Priestley-Taylor) que estimam a evapotranspiração da cultura, a partir de radiação, temperatura do ar e precipitação como parâmetros de entrada. Ambos os modelos, quando comparados com o modelo de razão de Bowen, apresentaram resultados insatisfatórios, devido a tendência em superestimar a ETc. Pode-se dizer que o modelo de Penman-Monteith apresentou dados de evapotranspiração mais próximos da realidade

    Addressing the high cervical cancer rates along the Texas-Mexico border through community outreach, patient navigation, and provider training/telementoring

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    Objective: Cervical cancer incidence and mortality rates are 68% and 57% higher, respectively, along the Texas-Mexico border compared with the rest of the United States. This is likely due to a combination of low health literacy, limited access to affordable screening, and a lack of trained personnel to perform colposcopy, loop electrosurgical excision procedures (LEEP), and appropriate management of women with pre-invasive disease. The objective of our study was to increase cervical cancer screening, diagnosis, and treatment rates in the Rio Grande Valley (RGV). Method: We initiated a comprehensive program at two health centers and one mobile clinic in the RGV consisting of (1) a public education program designed for community health workers to teach women about cervical cancer screening and HPV vaccination coupled with patient navigation to participating clinics; (2) colposcopy and LEEP training for physicians and advanced-practice providers through locally held hands-on courses and mentoring program; and (3) implementation of Project ECHO (Extension for Community Health Outcomes), a well-established telementoring program using video conferencing to connect academic specialists with community providers for case-based learning. We compared screening, diagnosis, and treatment rates pre- and post-program implementation. Results: From November 2014 to June 2018, local providers screened 19,028 women with Pap ± HPV testing (baseline 12,460, 53% increase); performed colposcopy on 2,644 women with abnormal screening results (baseline 945, 180% increase); and performed 483 LEEP procedures for treatment of cervical dysplasia (baseline 0). Ten women were diagnosed with invasive cancer and navigated to one of the participating gynecologic oncologists for treatment (baseline N/A). Five additional providers in the RGV completed the mentoring program to be certified to perform colposcopy (100% increase from baseline of 5) and two additional providers to perform LEEP (baseline 0). ECHO telementoring video conferences have been held every two weeks for a total 94 sessions (average of 22 participants/session) with 182 patient cases presented and discussed. Conclusion: Our comprehensive approach has led to an increase in the number of women undergoing cervical cancer screening and diagnosis/treatment of dysplasia. If sustained, we anticipate these efforts will decrease cervical cancer rates in the RGV. The program is currently being expanded to additional medically underserved regions of Texas

    Role of NBI fuelling in contributing to density peaking between the ICRH and NBI identity plasmas on JET

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    Density peaking has been studied between an ICRH and NBI identity plasma in JET. The comparison shows that 8 MW of NBI heating/fueling increases the density peaking by a factor of two, being R/L (n) = 0.45 for the ICRH pulse and R/L (n) = 0.93 for the NBI one averaged radially over rho (tor) = 0.4, 0.8. The dimensionless profiles of q, rho *, upsilon *, beta (n) and T (i)/T (e) approximate to 1 were matched within 5% difference except in the central part of the plasma (rho (tor) < 0.3). The difference in the curvature pinch (same q-profile) and thermo-pinch (T (i) = T (e)) between the ICRH and NBI discharges is virtually zero. Both the gyro-kinetic simulations and integrated modelling strongly support the experimental result where the NBI fuelling is the main contributor to the density peaking for this identity pair. It is to be noted here that the integrated modeling does not reproduce the measured electron density profiles, but approximately reproduces the difference in the density profiles between the ICRH and NBI discharge. Based on these modelling results and the analyses, the differences between the two pulses in impurities, fast ions (FIs), toroidal rotation and radiation do not cause any such changes in the background transport that would invalidate the experimental result where the NBI fuelling is the main contributor to the density peaking. This result of R/L (n) increasing by a factor of 2 per 8 MW of NBI power is valid for the ion temperature gradient dominated low power H-mode plasmas. However, some of the physics processes influencing particle transport, like rotation, turbulence and FI content scale with power, and therefore, the simple scaling on the role of the NBI fuelling in JET is not necessarily the same under higher power conditions or in larger devices

    The Pierre Auger Observatory III: Other Astrophysical Observations

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    Astrophysical observations of ultra-high-energy cosmic rays with the Pierre Auger ObservatoryComment: Contributions to the 32nd International Cosmic Ray Conference, Beijing, China, August 201
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