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1.
Cordoba Aldo Hernández Rafael Viveros-Palma Iliana Mendoza Sandra Guevara-González Ramón Gerardo Feregrino-Pérez Ana Angélica Esquivel Karen 《Environmental science and pollution research international》2021,28(28):37130-37141
Environmental Science and Pollution Research - Nowadays, the use of different nanoscale structures has been introduced to a large number of research areas. One of these is the treatment and... 相似文献
2.
D. M. S. Esquivel A. A. C. Corrêa O. S. Vaillant V. Bandeira de Melo G. S. Gouvêa C. G. Ferreira T. A. Ferreira E. Wajnberg 《Die Naturwissenschaften》2014,101(3):245-249
Insects have been used as models for understanding animal orientation. It is well accepted that social insects such as honeybees and ants use different natural cues in their orientation mechanism. A magnetic sensitivity was suggested for the stingless bee Schwarziana quadripunctata, based on the observation of a surprising effect of a geomagnetic storm on the nest-exiting flight angles. Stimulated by this result, in this paper, the effects of a time-compressed simulated geomagnetic storm (TC-SGS) on the nest-exiting flight angles of another stingless bee, Tetragonisca angustula, are presented. Under an applied SGS, either on the horizontal or vertical component of the geomagnetic field, both nest-exiting flight angles, dip and azimuth, are statistically different from those under geomagnetic conditions. The angular dependence of ferromagnetic resonance (FMR) spectra of whole stingless bees shows the presence of organized magnetic nanoparticles in their bodies, which indicates this material as a possible magnetic detector. 相似文献
3.
The Efficacy of a Programme of Landslide Risk Reduction in Areas of Unplanned Housing in the Eastern Caribbean 总被引:1,自引:0,他引:1
Malcolm G. Anderson Elizabeth Holcombe Maricarmen Esquivel Joaquin Toro Francis Ghesquiere 《Environmental management》2010,45(4):807-821
Poor countries are disproportionately affected by the cost of disasters. Yet there is evidence of the benefits of seeking
to mitigate the impact of a disaster, compared with the costs incurred in ‘making good’ after a major event has occurred.
This article reviews a programme of landslide risk reduction in unplanned communities in the Eastern Caribbean. The construction
of appropriate surface water management measures, based on the application of scientific and engineering principles, has been
demonstrated to reduce the hazard from rainfall-triggered landslides. Adopting a community-based approach additionally delivers
social and environmental benefits relating to employment generation, improvements in the environmental conditions within the
community, and improvements slope management practices. The sustained implementation of the community-based projects has provided
the necessary evidence-base for these practices to influence Government policy and practice, and gain recognition from regional
development agencies. The strategic and incremental uptake of the community-based methodology is demonstrated to be an effective
means for delivering physical landslide risk reduction measures in the most ‘at risk’ areas of unplanned housing. 相似文献
4.
Andre J. Riveros Darci M. S. Esquivel Eliane Wajnberg Robert B. Srygley 《Behavioral ecology and sociobiology》2014,68(1):55-62
How animals sense, process, and use magnetic information remains elusive. In insects, magnetic particles are candidates for a magnetic sensor. Recent studies suggest that the ant Pachycondyla marginata incorporates iron-containing particles from soil. We used leaf-cutter ants Atta colombica to test whether soil contact is necessary for developing a functional magnetic compass. A. colombica is the only invertebrate known to calculate a path-integrated home vector using a magnetic compass. Here, we show that A. colombica requires contact with soil to incorporate magnetic particles that can be used as a magnetic compass; yet, we also show that ants can biosynthesize magnetic particles. Workers from a soil-free colony ignored a 90° shift in the horizontal component of the geomagnetic field, yet oriented homeward despite the occlusion of any geocentric cues. In contrast, workers from a soil-exposed colony oriented to an intermediate direction between their true and subjective home in the shifted field. Homeward orientations under shifted fields suggest that ants calculated a path-integrated vector using proprioceptive information. Strikingly, ants from the soil-free colony also had magnetic particles; yet, as observed by ferromagnetic resonance, these particles differed from those in soil-exposed ants and were not associated with a magnetic compass sensitive to this experimental manipulation. 相似文献
5.
6.
Esquivel DM Wajnberg E do Nascimento FS Pinho MB Lins de Barros HG Eizemberg R 《Die Naturwissenschaften》2007,94(2):139-142
Six behavioural experiments were carried out to investigate the magnetic field effects on the nest-exiting flight directions
of the honeybee Schwarziana quadripunctata (Meliponini). No significant differences resulted during six experiment days under varying geomagnetic field and the applied static inhomogeneous
field (about ten times the geomagnetic field) conditions. A surprising statistically significant response was obtained on
a unique magnetic storm day. The magnetic nanoparticles in these bees, revealed by ferromagnetic resonance, could be involved
in the observed effect of the geomagnetic storm. 相似文献
7.
Acosta-Avalos D Esquivel DM Wajnberg E de Barros HG Oliveira PS Leal I 《Die Naturwissenschaften》2001,88(8):343-346
Route directions of migrations by the neotropical termite-hunting ant Pachycondyla marginata at a forest reserve in Southeast Brazil were analysed by circular statistic. Colony movement patterns were compared between the rainy/hot and dry/cold seasons. Migrations during the dry/cold season are significantly oriented 13 degrees with the magnetic North-South axis, while rainy/hot migrations do not exhibit a preferred direction. This result is discussed considering the hypothesis that P. marginata ants may use the geomagnetic field as an orientation cue for migrations in the dry/cold season. The presence of magnetic iron oxides in the head and abdomen of P. marginata is consistent with this suggestion. 相似文献
8.
Climate and Water Conflicts Coevolution from Tropical Development and Hydro‐Climatic Perspectives: A Case Study of Costa Rica
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Germain Esquivel‐Hernández Ricardo Sánchez‐Murillo Christian Birkel Jan Boll 《Journal of the American Water Resources Association》2018,54(2):451-470
Costa Rica is a nation with a vast wealth of water resources; however, recently the country has faced water conflicts (WC) due to social, economic, legal, and political impediments in response to limited water availability during El Niño events and inefficient use of its water resources. This study presents a spatial distribution and temporal analysis of WC in Costa Rica from 2005 to 2015. In total, 719 WC were analyzed of which 54% were among private individuals and government. The largest urban areas and the Grande de Tárcoles Basin were identified as the main “hot spot” for the conflicts. WC were mainly caused by spills of wastewater, water pollution, water shortage, infrastructure damage, and flooding, and can be predicted using a multiple linear model including the population size and the number of hydro‐meteorological events (HME) (R2 = 0.77). The identified HME also coevolved significantly with the changes in precipitation regimes (r = 0.67, p = 0.021). Our results suggest that there is a need to recognize that water infrastructure longevity across the country concatenates and amplifies WC, mainly in the most populated area located in the Central Valley. Implications of our findings include the need for truly integrated water resources management plans that include, for example, WC as indicators of hydro‐climatic changing conditions and water supply and sanitation infrastructure status. 相似文献
9.
Pablo Jiménez-Bonilla Jessica Salas-Arias Marianelly Esquivel Jose Roberto Vega-Baudrit 《Journal of Polymers and the Environment》2014,22(3):393-397
In Costa Rica, a lot of pineapple (Ananas comosus) and banana (Musa AAA) agroindustrial residues are generated each year. These residues can be used to obtain l-lactic acid by fermentation, ultrafiltration and electrodialysis. Poly(l-lactic acid) (PLLA) is a biodegradable and renewable polyester with many industrial and biomedical applications. There is a growing interest to improve the energetic efficiency of the synthesis of PLLA, because the main issue to produce this polymer is the high productive cost compared with petrochemical traditional commodities. In this research, the synthesis of PLLA through two different techniques was compared: microwave-assisted and conventional heating. On microwave synthesis the best results were obtained using lower temperatures and lower reaction times than the conventional heated synthesis. The reaction time was reduced from 15 h by conventional heating to 4.5 h using microwave-assisted synthesis. 相似文献
10.
Using Phylogenetic Diversity Measures to Set Priorities in Conservation: an Example from Southern South America 总被引:3,自引:0,他引:3
Paula Posadas ‡ Daniel R. Miranda Esquivel † Jorge V. Crisci 《Conservation biology》2001,15(5):1325-1334
Abstract: Phylogenetic diversity measures rank areas for biodiversity conservation priorities based on information encoded in phylogenies (cladograms). The goal of these ranks for conservation is to consider as many factors as possible that provide additional taxic information, such as taxa richness, taxa distributional patterns, area endemicity, and complementarity between areas. At present there are many measures that consider phylogenetic information, including node-based, genetic-distance, and feature-based measures. We devised a modified phylogenetic node-based index that we call "taxonomic endemicity standardized weight," which considers not only the taxonomic distinctness of the taxa that inhabit a given area but their endemicity as well. Once the standardized weight of the taxonomic endemicity identifies the area of highest priority, complementarity can be used to identify the second area and so on. We used this node-based index to rank priority areas for conservation in southern South America, and we compared the results of our rankings to results based on other node-based indexes. Our index identified Santiago district, in Central Chile province, as the highest priority area for conservation, followed by Maule, Malvinas, and districts of Subantarctic province. Malvinas exhibits greater complementarity relative to Santiago than Maule does, however, so Malvinas is ranked second in priority. Indexes based on phylogenetic information measure the evolutionary component of biodiversity and allow one to identify areas that will ensure the preservation of evolutionary potential and phylogenetically rare taxa. The modified index we propose is sensitive to taxic distinctness and endemicity as well and allows information from diverse taxa to be combined (i.e., different cladograms). The use of complementarity allows for preservation of the maximum quantity of taxa in a minimal number of protected areas. 相似文献