39 research outputs found
Palaeoecological assessment of prehistoric and historic human impact in the high elevation areas of the Northern Carpathians, Romania
This paper presents a high resolution, multi-proxy palaeoenvironmental reconstruction (pollen, dung fungal spores, micro and macro-charcoal, mineral magnetic properties and geochemistry) in three sedimentary sequences located at different elevations across the Northern Carpathians (Romania) over the Late Holocene (i.e. the last 4000 years). We aim to: i) determine what aspects of prehistoric and historic human activity (e.g. burning, clearing, grazing) have shaped the landscapes of today, and ii) use this information to facilitate their environmental management and conservation strategies to maintain the ecological and economic sustainability of extant habitats in the currently changing environmen
Fire as a driver of ecosystem dynamics in Central and Eastern Europe throughout the Lateglacial and Holocene
Sedimentary microscopic charcoal (particles smaller than 150 microns) has been used to describe multi-decadal to millennial scale biomass burning at regional scales, whereas macroscopic charcoal (particles larger than 150 microns) analysis is increasingly used to investigate past biomass burning at a local scal
Multi-proxy temperature and environmental reconstruction during the Late Glacial and Early Holocene in the Bohemian Forest, Central Europe
Multi-proxy temperature reconstructions can provide robust insights into past environmental conditions. By combining different proxies we can disentangle the temperature signal from the indirect climate effects on the environment. This study uses a multi-proxy approach to reconstruct temperature and palaeoenvironmental conditions during the Late Glacial and Early Holocene (13.5â8 cal. ka BP) in the Bohemian Forest, Central Europe. We assessed the similarity of the temperature signal based on chironomids, isoprenoid glycerol dialkyl glycerol tetraether lipids (isoGDGTs), and pollen within a comparison with locally modeled temperature data generated by the CHELSA_Trace21k dataset. Pollen, macroscopic charcoal remains, and geochemistry were further used to reconstruct past environmental conditions such as vegetation dynamics, fire activity, the input of lithogenic material (Titanium), nutrient content (Total Nitrogen) and the sources of organic matter (C/N and ÎŽ13Corg). All temperature reconstructions based on independent proxies were positively correlated and followed the same long-term trend. However, results also showed that chironomids-inferred July temperature had lower amplitude variations compared to the other temperature curves. IsoGDGTs showed the most pronounced decrease in temperature values at the onset of the Younger Dryas (YD), corroborating that this cooling event was more marked during winter than summer. However, a decrease of less than 1 °C during summer and two short-term warm events at 12.6 and 12.2 cal ka BP provoked a modest and asynchronous response of the vegetation to the onset of the YD. Nevertheless, isoGDGTs appeared to react to changes in both temperature and organic carbon sources, particularly between 11.2 and 10.6 cal yr BP. These environmental changes, characterized by high values of the GDGT-0/crenarchaeol ratio, recorded an increase in methanogenic activity in the lake sediments, which likely altered the recorded climatic signal. The corresponding anoxic episodes in the lake sediments might be caused by an increasing input of organic carbon from the catchment, related to the development of the vegetation and catchment soils at the beginning of the Holocene. Finally, pollen-based temperature reconstruction showed a lag in the response to major climatic events, such as the onset of YD and Holocene. Our study increases the understanding of the climate-vegetation-environmental feedback during the Late Glacial and Early Holocene in the Bohemian Forest, Central Europe
Fire hazard modulation by long-term dynamics in land cover and dominant forest type in eastern and central Europe
Wildfire occurrence is influenced by climate, vegetation and human activities. A key challenge for understanding the risk of fires is quantifying the mediating effect of vegetation on fire regimes. Here, we explore the relative importance of Holocene land cover, land use, dominant functional forest type, and climate dynamics on biomass burning in temperate and boreo-nemoral regions of central and eastern Europe over the past 12 kyr. We used an extensive data set of Holocene pollen and sedimentary charcoal records, in combination with climate simulations and statistical modelling. Biomass burning was highest during the early Holocene and lowest during the mid-Holocene in all three ecoregions (Atlantic, continental and boreo-nemoral) but was more spatially variable over the past 3â4 kyr. Although climate explained a significant variance in biomass burning during the early Holocene, tree cover was consistently the highest predictor of past biomass burning over the past 8 kyr. In temperate forests, biomass burning was high at ~ 45% tree cover and decreased to a minimum at between 60% and 70% tree cover. In needleleaf-dominated forests, biomass burning was highest at ~60 %â65%tree cover and steeply declined at > 65% tree cover. Biomass burning also increased when arable lands and grasslands reached ~15 %â20 %, although this relationship was variable depending on land use practice via ignition sources, fuel type and quantities. Higher tree cover reduced the amount of solar radiation reaching the forest floor and could provide moister, more wind-protected microclimates underneath canopies, thereby decreasing fuel flammability. Tree cover at which biomass burning increased appears to be driven by warmer and drier summer conditions during the early Holocene and by increasing human influence on land cover during the late Holocene. We suggest that longterm fire hazard may be effectively reduced through land cover management, given that land cover has controlled fire regimes under the dynamic climates of the Holocene
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Effect of Hydrocortisone on Mortality and Organ Support in Patients With Severe COVID-19: The REMAP-CAP COVID-19 Corticosteroid Domain Randomized Clinical Trial.
Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited. Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19. Design, Setting, and Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin. Between March 9 and June 17, 2020, 614 adult patients with suspected or confirmed COVID-19 were enrolled and randomized within at least 1 domain following admission to an intensive care unit (ICU) for respiratory or cardiovascular organ support at 121 sites in 8 countries. Of these, 403 were randomized to open-label interventions within the corticosteroid domain. The domain was halted after results from another trial were released. Follow-up ended August 12, 2020. Interventions: The corticosteroid domain randomized participants to a fixed 7-day course of intravenous hydrocortisone (50 mg or 100 mg every 6 hours) (nâ=â143), a shock-dependent course (50 mg every 6 hours when shock was clinically evident) (nâ=â152), or no hydrocortisone (nâ=â108). Main Outcomes and Measures: The primary end point was organ support-free days (days alive and free of ICU-based respiratory or cardiovascular support) within 21 days, where patients who died were assigned -1 day. The primary analysis was a bayesian cumulative logistic model that included all patients enrolled with severe COVID-19, adjusting for age, sex, site, region, time, assignment to interventions within other domains, and domain and intervention eligibility. Superiority was defined as the posterior probability of an odds ratio greater than 1 (threshold for trial conclusion of superiority >99%). Results: After excluding 19 participants who withdrew consent, there were 384 patients (mean age, 60 years; 29% female) randomized to the fixed-dose (nâ=â137), shock-dependent (nâ=â146), and no (nâ=â101) hydrocortisone groups; 379 (99%) completed the study and were included in the analysis. The mean age for the 3 groups ranged between 59.5 and 60.4 years; most patients were male (range, 70.6%-71.5%); mean body mass index ranged between 29.7 and 30.9; and patients receiving mechanical ventilation ranged between 50.0% and 63.5%. For the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively, the median organ support-free days were 0 (IQR, -1 to 15), 0 (IQR, -1 to 13), and 0 (-1 to 11) days (composed of 30%, 26%, and 33% mortality rates and 11.5, 9.5, and 6 median organ support-free days among survivors). The median adjusted odds ratio and bayesian probability of superiority were 1.43 (95% credible interval, 0.91-2.27) and 93% for fixed-dose hydrocortisone, respectively, and were 1.22 (95% credible interval, 0.76-1.94) and 80% for shock-dependent hydrocortisone compared with no hydrocortisone. Serious adverse events were reported in 4 (3%), 5 (3%), and 1 (1%) patients in the fixed-dose, shock-dependent, and no hydrocortisone groups, respectively. Conclusions and Relevance: Among patients with severe COVID-19, treatment with a 7-day fixed-dose course of hydrocortisone or shock-dependent dosing of hydrocortisone, compared with no hydrocortisone, resulted in 93% and 80% probabilities of superiority with regard to the odds of improvement in organ support-free days within 21 days. However, the trial was stopped early and no treatment strategy met prespecified criteria for statistical superiority, precluding definitive conclusions. Trial Registration: ClinicalTrials.gov Identifier: NCT02735707
26th Annual Computational Neuroscience Meeting (CNS*2017): Part 3 - Meeting Abstracts - Antwerp, Belgium. 15â20 July 2017
This work was produced as part of the activities of FAPESP Research,\ud
Disseminations and Innovation Center for Neuromathematics (grant\ud
2013/07699-0, S. Paulo Research Foundation). NLK is supported by a\ud
FAPESP postdoctoral fellowship (grant 2016/03855-5). ACR is partially\ud
supported by a CNPq fellowship (grant 306251/2014-0)
SISTEMUL ELICOIDAL DE INOVARE â ANALIZÄ CRITICÄ
The intent of this article is to be a step to inform stakeholders in strategies implementation
to increase the level of development of our country and, therefore, interested in the well-being of
the society. It is reviewed the modern model of economic development through innovation of the
triple helix, which underlies the subsequent models, the quadruple helix, in the implementation of
which the author has a direct involvement, the quintuple and n-tuple helix. Critical comments on
these are presented in the attempt to adapt and make them applicable to the existing conditions at
present in our country. There are presented concrete examples of the implementation of the helical
development system through innovation at European level. Taking into account the innovative spirit
of the Romanian society, expressed by the number of creative people in our country and the number
and the value internationally recognized of their innovations and inventions, some sketches are
proposed for the creation of economic entities for them by using helicoidal models of innovation
in the perspective of their development at the level of creative, competitive and respected national
and international economic institutions. Also, opinions are presented regarding the implementation
of helical innovation models in order to develop economically deficient areas and to recover or
reactivate the destroyed or declining economic entities
Exploring the influence of local controls on fire activity using multiple charcoal records from northern Romanian Carpathians
International audienc