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1.
Sci Total Environ ; 915: 169881, 2024 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-38190895

RESUMEN

The hydrological restoration of coastal wetlands is an emerging approach for mitigating and adapting to climate change and enhancing ecosystem services such as improved water quality and biodiversity. This paper synthesises current knowledge on selecting appropriate modelling approaches for hydrological restoration projects. The selection of a modelling approach is based on project-specific factors, such as costs, risks, and uncertainties, and aligns with the overall project objectives. We provide guidance on model selection, emphasising the use of simpler and less expensive modelling approaches when appropriate, and identifying situations when models may not be required for project managers to make informed decisions. This paper recognises and supports the widespread use of hydrological restoration in coastal wetlands by bridging the gap between hydrological science and restoration practices. It underscores the significance of project objectives, budget, and available data and offers decision-making frameworks, such as decision trees, to aid in matching modelling methods with specific project outcomes.

2.
Sci Data ; 9(1): 744, 2022 12 02.
Artículo en Inglés | MEDLINE | ID: mdl-36460674

RESUMEN

The Chesapeake Bay is a region along the eastern coast of the United States where sea-level rise is confounded with poorly resolved rates of land subsidence, thus new constraints on vertical land motions (VLM) in the region are warranted. In this paper, we provide a description of two campaign-style Global Positioning System (GPS) datasets, explain the methods used in data collection and validation, and present the experiment designed to quantify a new baseline of VLM in the Chesapeake Bay region of eastern North America. Data from GPS campaigns in 2019 and 2020 are presented as ASCII RINEX2.11 files and logsheets for each observation from the campaigns. Data were quality checked using the open-source program TEQC, resulting in average multipath 1 and 2 values of 0.68 and 0.57, respectively. All data are archived and publicly available for open access at the geodesy facility UNAVCO to abide by Findable, Accessible, Interoperable, Reusable (FAIR) data principles.

3.
Sci Rep ; 12(1): 17636, 2022 10 21.
Artículo en Inglés | MEDLINE | ID: mdl-36271232

RESUMEN

"Blue carbon" wetland vegetation has a limited freshwater requirement. One type, mangroves, utilizes less freshwater during transpiration than adjacent terrestrial ecoregions, equating to only 43% (average) to 57% (potential) of evapotranspiration ([Formula: see text]). Here, we demonstrate that comparative consumptive water use by mangrove vegetation is as much as 2905 kL H2O ha-1 year-1 less than adjacent ecoregions with [Formula: see text]-to-[Formula: see text] ratios of 47-70%. Lower porewater salinity would, however, increase mangrove [Formula: see text]-to-[Formula: see text] ratios by affecting leaf-, tree-, and stand-level eco-physiological controls on transpiration. Restricted water use is also additive to other ecosystem services provided by mangroves, such as high carbon sequestration, coastal protection and support of biodiversity within estuarine and marine environments. Low freshwater demand enables mangroves to sustain ecological values of connected estuarine ecosystems with future reductions in freshwater while not competing with the freshwater needs of humans. Conservative water use may also be a characteristic of other emergent blue carbon wetlands.


Asunto(s)
Carbono , Ecosistema , Humanos , Secuestro de Carbono , Humedales , Agua Dulce , Agua
4.
Bioscience ; 69(3): 180-190, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30899122

RESUMEN

As humanity continues to grow in size, questions related to human rights and the existing unequal distribution of food resources have taken on greater urgency. Is inequality in food access unjust or a regrettable consequence of the geographic distribution of biophysical resources? To what extent are there obligations to redress inequalities in access to food? We draw from a human rights perspective to identify obligations associated with access to food and develop a quantitative framework to evaluate the fulfillment of the human right to food. We discuss the capacity of socioeconomic development to reduce inequalities in per capita food availability with respect to the distribution of biophysical resources among countries. Although, at the country level, international trade shows the capacity to reduce human rights deficits by increasing food availability in countries with limited food production, whether it actually improves the fulfillment of the right to food will depend on within-country inequality.

5.
Environ Res Lett ; 12(2)2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32818038

RESUMEN

Ensuring food security requires food production and distribution systems function throughout disruptions. Understanding the factors that contribute to the global food system's ability to respond and adapt to such disruptions (i.e. resilience) is critical for understanding the long-term sustainability of human populations. Variable impacts of production shocks on food supply between countries indicate a need for national-scale resilience indicators that can provide global comparisons. However, methods for tracking changes in resilience have had limited application to food systems. We developed an indicator-based analysis of food systems resilience for the years 1992-2011. Our approach is based on three dimensions of resilience: socio-economic access to food in terms of income of the poorest quintile relative to food prices, biophysical capacity to intensify or extensify food production, and the magnitude and diversity of current domestic food production. The socio-economic indicator has large variability, but with low values concentrated in Africa and Asia. The biophysical capacity indicator is highest in Africa and Eastern Europe, in part because of high potential for extensification of cropland and for yield gap closure in cultivated areas. However, the biophysical capacity indicator has declined globally in recent years. The production diversity indicator has increased slightly, with a relatively even geographic distribution. Few countries had exclusively high or low values for all indicators. Collectively, these results are the basis for global comparisons of resilience between nations, and provide necessary context for developing generalizations about the resilience in the global food system.

6.
PLoS One ; 11(11): e0165941, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27832118

RESUMEN

The easy access to large data sets has allowed for leveraging methodology in network physics and complexity science to disentangle patterns and processes directly from the data, leading to key insights in the behavior of systems. Here we use country specific food production data to study binary and weighted topological properties of the bipartite country-food production matrix. This country-food production matrix can be: 1) transformed into overlap matrices which embed information regarding shared production of products among countries, and or shared countries for individual products, 2) identify subsets of countries which produce similar commodities or subsets of commodities shared by a given country allowing for visualization of correlations in large networks, and 3) used to rank country fitness (the ability to produce a diverse array of products weighted on the type of food commodities) and food specialization (quantified on the number of countries producing a specific food product weighted on their fitness). Our results show that, on average, countries with high fitness produce both low and high specializion food commodities, whereas nations with low fitness tend to produce a small basket of diverse food products, typically comprised of low specializion food commodities.


Asunto(s)
Minería de Datos/métodos , Tecnología de Alimentos , Comercio , Alimentos , Tecnología de Alimentos/economía , Tecnología de Alimentos/métodos , Tecnología de Alimentos/estadística & datos numéricos , Humanos , Internacionalidad
7.
Proc Natl Acad Sci U S A ; 112(22): 6902-7, 2015 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-25964361

RESUMEN

The escalating food demand by a growing and increasingly affluent global population is placing unprecedented pressure on the limited land and water resources of the planet, underpinning concerns over global food security and its sensitivity to shocks arising from environmental fluctuations, trade policies, and market volatility. Here, we use country-specific demographic records along with food production and trade data for the past 25 y to evaluate the stability and reactivity of the relationship between population dynamics and food availability. We develop a framework for the assessment of the resilience and the reactivity of the coupled population-food system and suggest that over the past two decades both its sensitivity to external perturbations and susceptibility to instability have increased.


Asunto(s)
Comercio/métodos , Abastecimiento de Alimentos/métodos , Modelos Económicos , Dinámica Poblacional , Comercio/tendencias , Demografía , Humanos
8.
ACS Appl Mater Interfaces ; 6(6): 3987-94, 2014 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-24593226

RESUMEN

Poly(vinylidene fluoride-co-tetrafluoroethylene) (PVDF-TFE) is confined between alternating layers of poly(ethylene terephthalate) (PET) utilizing a unique multilayer processing technology, in which PVDF-TFE and PET are melt-processed in a continuous fashion. Postprocessing techniques including biaxial orientation and melt recrystallization were used to tune the crystal orientation of the PVDF-TFE layers, as well as achieve crystallinity in the PET layers through strain-induced crystallization and thermal annealing during the melt recrystallization step. A volume additive model was used to extract the effect of crystal orientation within the PVDF-TFE layers and revealed a significant enhancement in the modulus from 730 MPa in the as-extruded state (isotropic) to 840 MPa in the biaxially oriented state (on-edge) to 2230 MPa in the melt-recrystallized state (in-plane). Subsequently, in situ wide-angle X-ray scattering was used to observe the crystal structure evolution during uniaxial deformation in both the as-extruded and melt-recrystallized states. It is observed that the low-temperature ferroelectric PVDF-TFE crystal phase in the as-extruded state exhibits equatorial sharpening of the 110 and 200 crystal peaks during deformation, quantified using the Hermans orientation function, while in the melt-recrystallized state, an overall increase in the crystallinity occurs during deformation. Thus, we correlated the mechanical response (strain hardening) of the films to these respective evolved crystal structures and highlighted the ability to tailor mechanical response. With a better understanding of the structural evolution during deformation, it is possible to more fully characterize the structural response to handling during use of the high-barrier PVDF-TFE/PET multilayer films as commercial dielectrics and packaging materials.

9.
PLoS One ; 8(2): e55825, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23457481

RESUMEN

The global trade of goods is associated with a virtual transfer of the water required for their production. The way changes in trade affect the virtual redistribution of freshwater resources has been recently documented through the analysis of the virtual water network. It is, however, unclear how these changes are contributed by different types of products and regions of the world. Here we show how the global patterns of virtual water transport are contributed by the trade of different commodity types, including plant, animal, luxury (e.g., coffee, tea, and alcohol), and other products. Major contributors to the virtual water network exhibit different trade patterns with regard to these commodity types. The net importers rely on the supply of virtual water from a small percentage of the global population. However, discrepancies exist among the different commodity networks. While the total virtual water flux through the network has increased between 1986 and 2010, the proportions associated with the four commodity groups have remained relatively stable. However, some of the major players have shown significant changes in the virtual water imports and exports associated with those commodity groups. For instance, China has switched from being a net exporter of virtual water associated with other products (non-edible plant and animal products typically used for manufacturing) to being the largest importer, accounting for 31% of the total water virtually transported with these products. Conversely, in the case of The United states of America, the commodity proportions have remained overall unchanged throughout the study period: the virtual water exports from The United States of America are dominated by plant products, whereas the imports are comprised mainly of animal and luxury products.


Asunto(s)
Comercio/métodos , Internacionalidad , Abastecimiento de Agua/economía , China , Comercio/economía , Comercio/historia , Historia del Siglo XX , Historia del Siglo XXI , Internacionalidad/historia , Internet , Modelos Económicos , Estados Unidos , Abastecimiento de Agua/análisis , Abastecimiento de Agua/historia
10.
J Am Osteopath Assoc ; 106(11): 647-52, 2006 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17192451

RESUMEN

Untreated trichophagia secondary to trichotillomania is a potentially life-threatening condition. Taking a thorough family and social history, most notably with the aid of a genogram or family tree, can aid in including this disorder in the differential diagnosis. This case presentation describes a unique occurrence of untreated trichotillomania in a female adolescent that led to formation of a trichobezoar requiring emergent surgical intervention and follow-up psychiatric treatment. This case highlights osteopathic medicine's fundamental concept of treating the whole person rather than just symptoms by considering factors such as genetic influences in understanding disease.


Asunto(s)
Bezoares/etiología , Tricotilomanía/complicaciones , Adolescente , Bezoares/cirugía , Femenino , Humanos , Medicina Osteopática , Tricotilomanía/psicología
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