78 research outputs found
Coastal risk mitigation by green infrastructure in Latin America
This paper aims to highlight the prevailing experiences of Latin America and to clarify what âgreen infrastructureâ entails in addition to describing seven case studies from a range of coastal ecosystems (wetlands, coastal dunes, beaches and coral reefs) at scales varying from local to regional. The case studies are categorised according to their degree of naturalness (nature-based, engineered ecosystems, soft engineering, ecologically enhanced hard infrastructure and de-engineering). Generally, the implementation of green infrastructure projects aims to increase resilience, enhance the provision of ecosystem services, recover biodiversity, reduce the negative effects of hard infrastructure and implement corrective measures. The greatest benefits of these projects relate to the creation of multi-functional spaces, which often combine the above advantages with improved opportunities for recreation and/or economic activities. It is hoped that this paper will disseminate the experience in green infrastructure among academics and practitioners and stimulate wider adoption of green infrastructure projects and good practices
Flora en playas y dunas costeras de MĂ©xico
Background and Aims: The first updated floristic checklist, supported with herbarium specimens, is presented for beaches and coastal sand dunes of Mexico.Methods: The analysis is based on the revision of 14 national and foreign herbaria. A 2 Ă 2 km grid was placed over a map of the coastal sand dunes of Mexico to reference the herbarium records, corresponding to the 2180 sites and 12,419 examples of plants documented. Indices of diversity, similarity, taxonomic diversity, and redundancy were calculated.Key results: The flora of the beaches and coastal sand dunes of Mexico consists of 153 families, 897 genera, and 2075 species of vascular plants. These represent 9.5% of the vascular flora of Mexico. The herbaria with high indices of redundancy (IRâ„0.7) are the herbarium of the Universidad Nacional AutĂłnoma de MĂ©xico (IR=0.9), the Centro de InvestigaciĂłn CientĂfica de YucatĂĄn (CICY, IR=0.8), the Centro de Investigaciones BiolĂłgicas del Noroeste (HCIB), the Instituto de EcologĂa, A.C. (XAL) and the Natural Museum in San Diego (SD), each with an IR of 0.7. Five floristic regions are clearly recognized, which correspond to the seas of Mexico. The North Pacific has the highest taxonomic diversity and the South Pacific has the least. The Gulf of California, Gulf of Mexico and the Caribbean Sea have very similar taxonomic diversity. The species with the most recorded occurrences are Trianthema portulacastrum (165), Croton punctatus (107), Echites umbellatus (106) and Ipomoea pes-caprae (90). Considering the ecotonal nature of the ecosystem, most dune plants are shared with neighboring vegetation (forests, scrubs, wetlands, such as marshes or mangrove swamps).Conclusions: This first checklist of the flora of beaches and coastal dunes is the baseline for multiple future studies: floristic, biogeographic, and ecological. Moreover, this list will be important if used in environmental assessments and coastal zone plans.Antecedentes y Objetivos: Se presenta el primer listado florĂstico de las playas y dunas costeras de MĂ©xico, actualizado y respaldado por ejemplares de herbario.MĂ©todos: Se revisaron 14 herbarios nacionales y extranjeros. Se sobrepuso una retĂcula de 2 Ă 2 km al mapa de la costa y de las dunas costeras de MĂ©xico para referir todos los registros que corresponden a 2180 sitios con 12,419 ejemplares de plantas. Se calcularon Ăndices de diversidad, similitud, diversidad taxonĂłmica y redundancia.Resultados clave: La flora registrada consta de 153 familias, 897 gĂ©neros y 2075 especies de plantas vasculares, las cuales representan 9.5% de la flora vascular de MĂ©xico. Las cinco colecciones con Ăndices de redundancia altos IRâ„0.7 son los herbarios de la Universidad Nacional AutĂłnoma de MĂ©xico (MEXU, IR=0.9), del Centro de InvestigaciĂłn CientĂficas de YucatĂĄn (CICY, IR=0.8), y los del Centro de Investigaciones BiolĂłgicas del Noroeste (HCIB), el Instituto de EcologĂa, A.C. (XAL) y el del Museo de Historia Natural de San Diego (SD), cada uno con un IR de 0.7. Se reconocen cinco regiones florĂsticas que corresponden a los mares de MĂ©xico. El PacĂfico Norte tiene mayor diversidad taxonĂłmica y el PacĂfico Sur menor diversidad taxonĂłmica. El Golfo de California, Golfo de MĂ©xico y Mar Caribe tienen diversidades taxonĂłmicas similares. Las especies con mĂĄs registros son Trianthema portulacastrum (165), Croton punctatus (107), Echites umbelllatus (106) e Ipomoea pes-caprae (90). Por el carĂĄcter de ecotono de las dunas costeras, la mayorĂa de las especies se comparten con los tipos de vegetaciĂłn vecinos (selvas, matorrales, y humedales como las marismas y manglares).Conclusiones: Esta primera lista de la flora en playas y dunas de MĂ©xico es la base para mĂșltiples estudios florĂsticos regionales y locales, biogeogrĂĄficos, y ecolĂłgicos; ademĂĄs, que serĂĄ importante para su uso en temas de impacto ambiental y manejo costero
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transientâs position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Seed germination of a rare neotropical canopy tree dormancy and the effects of abiotic factors
Chronic Abdominal Syndrome Due to Nervous Compression. Study of 100 Cases and Proposed Diagnostic-Therapeutic Algorithm
Multi-messenger Observations of a Binary Neutron Star Merger
On 2017 August 17 a binary neutron star coalescence candidate (later
designated GW170817) with merger time 12:41:04 UTC was observed through
gravitational waves by the Advanced LIGO and Advanced Virgo detectors.
The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray
burst (GRB 170817A) with a time delay of ⌠1.7 {{s}} with respect to
the merger time. From the gravitational-wave signal, the source was
initially localized to a sky region of 31 deg2 at a
luminosity distance of {40}-8+8 Mpc and with
component masses consistent with neutron stars. The component masses
were later measured to be in the range 0.86 to 2.26 {M}ÈŻ
. An extensive observing campaign was launched across the
electromagnetic spectrum leading to the discovery of a bright optical
transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC
4993 (at ⌠40 {{Mpc}}) less than 11 hours after the merger by the
One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The
optical transient was independently detected by multiple teams within an
hour. Subsequent observations targeted the object and its environment.
Early ultraviolet observations revealed a blue transient that faded
within 48 hours. Optical and infrared observations showed a redward
evolution over âŒ10 days. Following early non-detections, X-ray and
radio emission were discovered at the transientâs position ⌠9
and ⌠16 days, respectively, after the merger. Both the X-ray and
radio emission likely arise from a physical process that is distinct
from the one that generates the UV/optical/near-infrared emission. No
ultra-high-energy gamma-rays and no neutrino candidates consistent with
the source were found in follow-up searches. These observations support
the hypothesis that GW170817 was produced by the merger of two neutron
stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and
a kilonova/macronova powered by the radioactive decay of r-process
nuclei synthesized in the ejecta.</p
AnĂĄlisis de la flora de dunas costeras del litoral atlĂĄntico de MĂ©xico
The object of this paper is to analyze the Mexican coastal flora of the Gulf and Caribbean. Floristic and vegetation analysis of 44 beach sites comprising the Atlantic littoral of Mexico, revision of herbarium specimens (MEXU and XAL) and bibliography was used to obtain information. It was used to build a data base resulting in 655 species and 91 families. Species number per family and per site was obtained. Growth forms, species distribution in microhabitats, presence of species with different distribution or habitat preference (i.e. coastal, belonging to other vegetation types or secondary) are analyzed. Species frequency distribution along the Gulf sites is also discussed. Endemics and new records for Mexico are given. A synthesis of the coastal flora, its composition and problematics are analyzed, within the framework of an ecological point of view.En este trabajo se presenta un anĂĄlisis de la flora vascular de las dunas costeras del litoral mexicano del Golfo de MĂ©xico y del Mar Caribe, obtenido a travĂ©s del muestreo de 44 sitios, de la revisiĂłn de ejemplares de herbario y de la bibliografĂa. Con la informaciĂłn se elaborĂł una base de datos que integra 655 especies pertenecientes a 91 familias. Se determinĂł el nĂșmero de especies y gĂ©neros por familia, asĂ como la cantidad de especies y de familias presentes en cada sitio de colecta, al igual que las formas de crecimiento. Se enlistan las especies colectadas y su presencia a lo largo de las playas muestreadas del Golfo y Caribe. Se indican los taxa endĂ©micos para MĂ©xico
AnĂĄlisis de la flora de dunas costeras del Litoral AtlĂĄntico de MĂ©xico
En este trabajo se presenta un anĂĄlisis de la flora vascular de las dunas costeras del litoral mexicano del Golfo de MĂ©xico y del Mar Caribe, obtenido a travĂ©s del muestreo de 44 sitios, de la revisiĂłn de ejemplares de herbario y de la bibliografĂa. Con la informaciĂłn se elaborĂł una base de datos que integra 655 especies pertenecientes a 91 familias. Se determinĂł el nĂșmero de especies y gĂ©neros por familia, asĂ como la cantidad de especies y de familias presentes en cada sitio de colecta, al igual que las formas de crecimiento. Se enlistan las especies colectadas y su presencia a lo largo de las playas muestreadas del Golfo y Caribe. Se indican los taxa endĂ©micos para MĂ©xico
- âŠ