65 research outputs found
Disturbance distance: quantifying forests' vulnerability to disturbance under current and future conditions
Disturbances, both natural and anthropogenic, are critical determinants of forest structure, function,
and distribution. The vulnerability of forests to potential changes in disturbance rates remains largely
unknown. Here, we developed a framework for quantifying and mapping the vulnerability of forests
to changes in disturbance rates. By comparing recent estimates of observed forest disturbance rates
over a sample of contiguous US forests to modeled rates of disturbance resulting in forest loss, a novel
index of vulnerability, Disturbance Distance, was produced. Sample results indicate that 20% of
current US forestland could be lost if disturbance rates were to double, with southwestern forests
showing highest vulnerability. Under a future climate scenario, the majority of US forests showed
capabilities of withstanding higher rates of disturbance then under the current climate scenario,
which may buffer some impacts of intensified forest disturbanceinfo:eu-repo/semantics/publishedVersio
Septal aperture of the humerus: Aetiology and frequency rates in two European populations.
Analysis of the septal aperture was conducted on two documented European populations. Collections from the National Museum of Natural History Lisbon, Portugal and University of Athens, Greece were used for the study. Both collections are modern and documented for sex and age. The Portuguese sample comprises 297 individuals (149 males and 148 females) between the ages of 18 and 88. A septal aperture was observed in 50 individuals resulting in a frequency of 16.83%. The Greek sample comprises 117 individuals (68 males and 49 females) between the ages of 20 and 65. Twenty-five septal apertures were observed, giving a frequency of 21.37%. Both populations had high frequencies which exceeded those observed in European countries in previous studies. Sex analysis shows that both samples confirm that septal apertures are more common in females. The Portuguese sample also supports that septal apertures are more common in the left humerus, however the Greek sample had a higher frequency of bilateral cases. Measurements of the Portuguese sample were taken to determine whether robusticity correlates with presence of septal apertures. These measurements concluded that there was no difference in robusticity with presence or absence of a septal aperture, challenging previous studies
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Assessing the impacts of 1.5 °C global warming – simulation protocol of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP2b)
In Paris, France, December 2015, the Conference of the Parties (COP) to the United Nations Framework Convention on Climate Change (UNFCCC) invited the Intergovernmental Panel on Climate Change (IPCC) to provide a "special report in 2018 on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways". In Nairobi, Kenya, April 2016, the IPCC panel accepted the invitation. Here we describe the response devised within the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) to provide tailored, cross-sectorally consistent impact projections to broaden the scientific basis for the report. The simulation protocol is designed to allow for (1) separation of the impacts of historical warming starting from pre-industrial conditions from impacts of other drivers such as historical land-use changes (based on pre-industrial and historical impact model simulations); (2) quantification of the impacts of additional warming up to 1.5°C, including a potential overshoot and long-term impacts up to 2299, and comparison to higher levels of global mean temperature change (based on the low-emissions Representative Concentration Pathway RCP2.6 and a no-mitigation pathway RCP6.0) with socio-economic conditions fixed at 2005 levels; and (3) assessment of the climate effects based on the same climate scenarios while accounting for simultaneous changes in socio-economic conditions following the middle-of-the-road Shared Socioeconomic Pathway (SSP2, Fricko et al., 2016) and in particular differential bioenergy requirements associated with the transformation of the energy system to comply with RCP2.6 compared to RCP6.0. With the aim of providing the scientific basis for an aggregation of impacts across sectors and analysis of cross-sectoral interactions that may dampen or amplify sectoral impacts, the protocol is designed to facilitate consistent impact projections from a range of impact models across different sectors (global and regional hydrology, lakes, global crops, global vegetation, regional forests, global and regional marine ecosystems and fisheries, global and regional coastal infrastructure, energy supply and demand, temperature-related mortality, and global terrestrial biodiversity)
The Regulatory Role of Rac1, a Small Molecular Weight GTPase, in the Development of Diabetic Retinopathy
Diabetic retinopathy, a microvascular complication of diabetes, remains the leading cause of vision loss in working age adults. Hyperglycemia is considered as the main instigator for its development, around which other molecular pathways orchestrate. Of these multiple pathways, oxidative stress induces many metabolic, functional and structural changes in the retinal cells, leading to the development of pathological features characteristic of this blinding disease. An increase in cytosolic reactive oxygen species (ROS), produced by cytosolic NADPH oxidase 2 (Nox2), is an early event in the pathogenesis of diabetic retinopathy, which leads to mitochondrial damage and retinal capillary cell apoptosis. Activation of Nox2 is mediated through an obligatory small molecular weight GTPase, Ras-related C3 botulinum toxin substrate 1 (Rac1), and subcellular localization of Rac1 and its activation are regulated by several regulators, rendering it a complex biological process. In diabetes, Rac1 is functionally activated in the retina and its vasculature, and, via Nox2-ROS, contributes to mitochondrial damage and the development of retinopathy. In addition, Rac1 is also transcriptionally activated, and epigenetic modifications play a major role in this transcriptional activation. This review focusses on the role of Rac1 and its regulation in the development and progression of diabetic retinopathy, and discusses some possible avenues for therapeutic interventions
Climatic stresses and rural emigration in Guatemala
International migration is a recurrent and growing phenomenon and a large share of emigrants originate from rural areas. This study examines the association between climatic stresses and rural emigration in Guatemala. We exploit variations on climatic stress situations and emigration flows at the subnational level and over time to examine whether the observed migration dynamics can be explained by the occurrence of specific adverse weather events. We find that drought periods affect emigration positively the following year, especially among men, while periods of high temperatures and low soil moisture affect male and female emigration negatively. The results are generally not much sensitive to alternative model specifications and estimations. The apparent mixed findings point to both direct effects where climatic stresses may encourage people to migrate in search of better opportunities, as well as indirect effects in the sense that climatic stresses affect agricultural productivity and household liquidity, which may prevent people from migrating despite their willingness to emigrate
Abstract 13955: Establishing a prehospital protocol for local emergency services improves symptom onset-to-balloon time in patients with ST-segment elevation myocardial infarction
Background: Delay in symptom recognition and calling 911 for patients with ST-segment elevation myocardial infarction (STEMI) continues to challenge many hospitals’ STEMI systems. Research has historically focused on door-to-balloon time and inpatient treatment, with little known on the impact of engaging emergency services (EMS) to provide a team approach to patient care, from community education to prehospital activation. Purpose: Evaluate the impact of a collaboration with local EMS agencies in our institution’s STEMI system designed to develop a prehospital protocol and joint community education efforts. Methods: Data collected from NCDR ACTION Registry-Mission Lifeline reports from 2011 to 2013 was analyzed to identify recent trends in prehospital STEMI quality metrics. After evaluation of 2011 data, a regional plan was developed and implemented in 2012 to address prehospital system barriers, including public education and revision of a prehospital protocol. Results: In 2011, a majority of patients used private transport when having a STEMI. Following protocol implementation, STEMI patients were able to identify symptoms earlier and appropriately call 911 earlier. As a result, a first medical contact (FMC)-to-balloon time of \u3c 90 minutes increased to 72% of patients, time from symptom onset to balloon decreased, and postprocedure complication rate improved (Table). Conclusions: Establishing a collaborative prehospital protocol between hospitals and EMS can have a positive impact on outcomes in STEMI patients. With more awareness and earlier notification of incoming STEMI patients, hospitals can significantly decrease symptom onset-to-balloon time. Evaluation of time from symptom onset to device activation may be a better way to measure quality than door-to-balloon time, as evidenced by a decrease in postprocedure complications associated with decreased overall times
Monitoring forest degradation from charcoal production with historical Landsat imagery. A case study in southern Mozambique
We used historical Landsat imagery to monitor forest degradation from charcoal production in the main supplying region of the Mozambican capital, Maputo, during a ten-year period (2008–2018). We applied a change detection method that exploits temporal NDVI dynamics associated with charcoal production. This forest degradation temporal sequence exposes the magnitude and the spatial and temporal dynamics of charcoal production, which is the main forest degradation driver in sub-Saharan Africa. The annual area under charcoal production has been steadily increasing since 2008 and reached 11 673 ha in 2018. The total forest degraded extent in the study area during the 10-year study period covered 79 630 ha, which represents 68% of the available mopane woodlands in 2008. Only 5% of the available mopane woodlands area remain undisturbed in the study area. Total gross carbon emissions associated charcoal production during this 10-year period were estimated in 1.13 Mt. These results mark forest degradation from charcoal production as the main driver of forest cover change in southern Mozambique. They also denote that, while charcoal production may be relatively localized in space, its implications for forest cover change and carbon emissions in a sub-Saharan African context are relevant at larger geographical scales. This study represents a proof of concept of the feasibility of medium resolution Earth observation data to monitor forest degradation from charcoal production in the context of the growing urban energy demand. It also highlights the potential opportunities to improve REDD+ monitoring, reporting and verification efforts in sub-Saharan Africa as a first step toward designing effective management and policy interventions
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